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Gain an understanding of brain development and the impact of the digital age on the brain. Learn how to engage 21st-Century Learners by promoting creativity, music, social emotional intelligence, and other strategies. Teaching in the Digital Age requires one book entitled br@in-based teaching 🙂 in the digital age by Marilee Sprenger. After completing the course Teaching the Digital Brain, you will demonstrate or indicate: A. How you currently relate to and teach to the “digital brain.” B. Knowledge of how the brain works and how the digital age has affected it. C. The ability to engage students and enhance learning without technology. D. How to create positive learning environments for 21 Century students. E. Knowledge of Gardner’s theory of multiple intelligences and how it can apply to your curriculum. F. The benefits of using music in your classroom. G. Knowledge of how our memory works and classroom strategies to enhance it. H. How to build social-emotional intelligence in your students. I. The ability to incorporate creativity, synthesis, and empathy skills into your curriculum. J. How we should be teaching our students in the digital age. For this assignment, you will be asked to reflect on your relationship with technology, how you utilize it in your classroom, as well as balance your curriculum to educate the whole child. 2. How the Brain Works In this section you will learn what may be happening in a student’s brain when they are suffering from various mental health issues as well as ways to help them. In addition, you will communicate both the positive and negative affects the digital age is having on our brains. 3. The Need For Low Tech For assignment three, you will be demonstrating how low tech teaching techniques and programs can engage students, improve test scores, and promote creativity and interpersonal skills. 4. Learning Environments By completing the fourth assignment, you will be exhibiting how to provide the ideal learning environment for 21 Century Students. You will need to explain how you balance the priorities of safety, healthy lifestyles, flexibility, community, family, technology, etc… B.A., M.S. in Counseling Clinical School Psychology K-12 School Psychologist 20+ years. Collegiate Professional Development Coordinator, Developer, and Instructor 16+. “I take pride in helping educators enhance student learning while bringing passion into their classrooms.” Ryan loves spending time with family and friends, especially outdoors. His favorite activities include snowboarding, golf, and hiking. Instructor: Ryan Pickett
Morning sickness is nausea that occurs during pregnancy. Morning sickness affects a large proportion of pregnant women. It is most common during the first trimester. Morning sickness does not hurt the baby in any way unless you lose weight, such as with severe vomiting. Mild weight loss during the first trimester is not uncommon when women have moderate symptoms, and is not harmful to the baby. The amount of morning sickness during one pregnancy does not predict how you will feel in future pregnancies. Hormonal changes of pregnancy are thought to play a role. Rarely, severe or persistent nausea or vomiting may be caused by a medical condition unrelated to pregnancy such as thyroid or liver disease. Treatment isn't necessary for most cases of morning sickness. If your morning sickness symptoms persist, however, your pregnancy care provider may prescribe vitamin B-6 supplements, antihistamines and possibly anti-nausea medications. Most women (87-91%) report cessation of symptoms by 16-20 weeks of pregnancy. Although nausea and vomiting is commonly referred to as ?morning sickness?, only 11-18% of women report having nausea and vomiting confined to the morning.
Facing unknowns is very difficult. Facing an ever growing list of unknowns ups the challenge. The most looming unknown is COVID-19. It is a matter of life and death. As we continue to face this pandemic we are hit with the news of over 207,000 deaths, over a million cases, children trying to risk going to school and a President who has just contracted it. Fear can pull us into anger and blame that rarely takes away risk and uncertainty. If anything, it exhausts our resources for planning and coping. Far better to re-boot our capacity to cope. Here are some strategies. The best way to quiet the “ What if’s” is “ What can I do now?” We need to get the latest most valid information on guidelines for prevention, transmission and spread in order to plan for self and family members. Listed below are some important clarifications. What We Now Know Here is some updated Information about transmission, exposure and testing that has changed as experts have dealt with COVID-19 since March 2020. The virus that causes COVID-19 is thought to spread mainly from person-to-person through respiratory droplets produced when an infected person coughs, sneezes, or talks. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Masks are the most important way to prevent this spread, It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes. This is not thought to be the main way the virus spreads. ( cdc.gov) Prevention and Protection The best way to protect yourself against COVID-19 is by wearing a mask and maintaining physical distance of at least 3 feet. This virus is spread by droplets and aerosol from an infected person. Because people may have the virus and may not yet be showing symptoms, anyone with or without symptoms is a potential source of infection for others. Anyone of any age can become infected and spread the virus – even if they never become symptomatic. Being vigilant about your own exposure before you spend time with others – is mutual care. Testing is crucial and findings must be considered in the light of new information. According to the FDA, the most common Diagnostic tests are the Molecular Tests like the RT-PCR test or the Antigen Test. - The Molecular test, like the RT-PCR test, detects the virus’s genetic material. It is taken with a nasal or throat swap, has results in one week or same day depending on location and is considered highly accurate. - The Antigen test which detects the virus’s genetic material is the Rapid Test involving a nasal or throat swap and with results in one hour. The positive findings are considered accurate but negative findings may need to be confirmed with a Molecular Test. If you have had no exposure to anyone who might be carrying COVID-19, a negative result on a COVID-19 test may well be accurate. Exposure and Test Results A negative test result in situations where you have been exposed to anyone who tests positive must be considered in terms of time of exposure, contraction and build-up of virus in your system over the course of several days. Retesting may result in a positive test result. - In a systematic review of seven studies published in May 2020, researchers at Johns Hopkins University considered that the time between exposure and testing positive may be much longer than just a day or two. When taking the P.C.R., after a possible exposure, it makes sense to wait three or four days, ideally self-quarantining while waiting and then getting a test a few days later. - The researchers maintain that there is not chance that a test will work in the first day or two after exposure when the false negative rate can be from 60 to 100%. The danger of actually thinking you are negative when it is simply too early to tell is dangerous for you and others. Other Factors – When considering your possibility of exposure and contraction, experts suggest considering: - Do you have symptoms ( shortness of breath, fever, extreme fatigue)? - Do you live in a community where the virus is on an upswing? - Have you been at large gatherings or exposed to someone who tested positive. If so, than re-testing may be very important to you and the spread of COVID-19. Reducing Feelings of Helplessness - The sense of helplessness is what is terrifying to adults and children. - Provide facts to children and teens about what is going on now and information to reduce their risk of being infected-in words they understand depending on their age. - Make plans for every day that involve small and big goals that consider safety. - Creative ways to connect by Zoom or to do some of what you need to do or love to do while being at a distance with masks on may feel like a safe accomplishment. - A universal factor that mediates our experience of fear and uncertainty is our connection with familiar networks of support (family, friends that are family and pets) The bond in such groups offers predictable support and validation. - Hold on to loved ones through creative means if contact or social media contact is not possible. Go through pictures, draw pictures to be given at a later time to children or grandparents. Narrate your healing by writing your story or keeping a gratitude journal. Children can be encouraged to write their story of the situation or make a book of pictures. A family diary can be kept with everyone adding even one sentence of good, bad, funny, unexpected events, thoughts and feelings each day… Five years from now it will be precious. - Given the parent-child stress connection, we know that a parent’s own stress regulation and sense of constancy is a reliable resource that offsets the impact of the unexpected for a child. - Parents need rest and turns at being “ Off the Job” They are the physical and emotional lifeline for their children. Someone once told me that the mother of a large family in the 1950’s stopped everything at 1 PM in the afternoon to lay down on the couch and watch her favorite soap opera – She was re-booting. - When parents find ways to regulate anxiety and deal with uncertainty – the children benefit. Working With Body and Mind One of the most important ways to cope with fear and uncertainty is to pay attention to body rhythms. - Daily routines like exercise of any type, biking, running, playing ball, walking your dog, playing outside with children are all invaluable in lowering stress. - Connection around fun activities a four-way crossword puzzle, watching an evening sitcom (laughter is a great stress reducer), listening to your favorite music, all reduce the hyperarousal associated with the body’s fight/flight stress reactions. - Children big and small can reset calm through connection with pets, favorite toys, playing musical instruments, listening and even dancing to music or some version of that. Sleeping is crucial in regulating the anxiety and worry that disrupt body’s rhythms. - A recent study on the impact of fear on insomnia offered unexpected results. Whereas it was predicted that the greater the fear, the greater the insomnia or lack of REM sleep, the finding showed that it was a subject’s response to safety that was the important factor. Regardless of how much fear a person had (as measured by startle response) the ability to re-establish a sense of safety made the difference in sleep. - With that in mind, children and adults need bedtime rituals to create safety. There are many options in this culture. Anything that reboots your sense of safety from free mini relaxation sessions http://www.calm.com/to your favorite book, blanket, meditation or prayer can make a difference. The consistent use of it conditions your mind and body for a respite. Holding on to Hope Be it through meditation, prayer or the amazing gifts of nature, many lift their spirits and resilience in uncertain times by holding on to hope. Hope is the belief in options in the future. It is seeded by catching glimpses of the new flower, the sound of laughter, the sight of children’s awe, the feel of a pets’ love, the power of human kindness. It is what makes this journey together possible…. Listen in to Renowned Epidemiologist, Dr. Gary Slutkin discuss “ Coping with Two Epidemics- COVID-19 and Violence on Psych Up Live- Be Safe -Suzanne
Researchers have used the Swiss Light Source SLS to record a molecular energy machine in action and thus to reveal how energy production at cell membranes works. For this purpose they developed a new investigative method that could make the analysis of cellular processes significantly more effective than before. They have now published their results in the journal Science. In all living things, structural changes in proteins are responsible for many biochemically controlled functions, for example energy production at cell membranes. The protein bacteriorhodopsin occurs in microorganisms that live on the surface of lakes, streams, and other bodies of water. Activated by sunlight, this molecule pumps positively charged particles, protons, from the inside to the outside through the cell membrane. While doing this, it is constantly changing its structure. The researchers were already able to elucidate one part of this process at free-electron X-ray lasers (FELs) such as SwissFEL. Now they have also managed to record the still unknown part of the process in a kind of molecular movie. "With the new method at SLS, we can now follow the last part of the movement of bacteriorhodopsin, where the steps are in the millisecond range", explains first author of the paper. "With measurements at FELs in the USA and Japan, we had already measured the first two sub-processes before SwissFEL was commissioned", the author says. "These take place very fast, within femtoseconds to microseconds." A femtosecond is one-trillionth of a second. To be able to observe such processes, the researchers use so-called "pump-probe" crystallography. With this method, they can take snapshots of protein movements that can then be assembled into movies. For the experiments, proteins are brought into crystal form. A laser beam, imitating sunlight, triggers the sequence of movements in the protein. X-rays that hit the sample afterwards produce diffraction images, which are recorded by a high-resolution detector. From these, computers generate an image of the protein structure at each point in time. The movie created from the measurements at SLS shows how the structure of the bacteriorhodopsin molecule changes in the next 200 milliseconds after it is activated by light. With that, a complete so-called "photocycle" of the molecule has now been elucidated. Bacteriorhodopsin functions as a biological machine that pumps protons from inside the cell through the membrane to the outside. This creates a concentration gradient at the cell membrane. On its outer side, there are more protons than on its inner side. The cell uses this gradient to gain energy for its metabolism by allowing protons elsewhere to balance out the externally and internally different concentrations. In doing so, the cell produces ATP, a universal energy source in living things. Subsequently, bacteriorhodopsin restores the concentration gradient. "In the new study, we were now able to see the largest real-time structural changes in a molecule ever" - by "large" the scientist means nine angstroms, that is, one-millionth of the thickness of a human hair. Through these structural changes, a gap opens up in the protein in which a chain of water molecules forms, and this is responsible for the proton transport through the cell membrane. "Before us, no one had ever observed this water chain directly", the biochemist notes happily. "Researchers can use the new method and become much more efficient, since worldwide there are many more synchrotrons than free-electron lasers. Besides that, you need fewer protein crystals than are required for experiments at FELs", the author adds. Proton uptake mechanism in bacteriorhodopsin - 520 views
Setting Up a Municipal Mosquito Control Program A Practical Guide to the Design, Cost, and Implementation of Public Mosquito Control Mosquito control is undergoing major changes in Mississippi. Instead of just routinely spraying pesticides out of trucks several nights weekly, mosquito control personnel are now trying to get the most control with the least amount of pesticides. This involves source reduction to eliminate mosquito breeding areas, larviciding areas of standing water to kill the larvae, and carefully timed, strategically placed insecticides aimed at the adult mosquitoes. In this publication, we outline the components of an integrated mosquito control program with emphasis on incorporating surveillance and larviciding into existing programs. We give general information as a review of control and surveillance techniques commonly used. In addition, we describe some health problems from mosquitoes found in Mississippi. NOTE: Much of this publication was originally compiled by the former medical entomologist with the Mississippi State Department of Health, Ed Bowles. It has been revised several times. The Need for Mosquito Control Mosquitoes can affect human and animal health by both their nuisance biting and the diseases they carry (Figure 1). Mosquito-borne diseases have played an important role in our history. Epidemics of mosquito-borne diseases were once common in the United States. Outbreaks of yellow fever occurred as far north as Philadelphia during the colonial period, and epidemics took many lives in Memphis in 1878 and in New Orleans as recently as 1905. Dengue fever was prevalent along the Gulf Coast until 1945. Tombstones of Mississippians who died during epidemics can be seen in many old cemeteries in our state. Although these diseases have disappeared from Mississippi, their mosquito vectors (carriers) have not. If these two disease agents became reintroduced into Mississippi, they could be transmitted by the yellow fever mosquito (Aedes aegypti) and the introduced Asian tiger mosquito (Aedes albopictus). At one time, malaria was well established in the continental United States, especially in the southern states. Eradication of malaria from the United States is attributed more to the short transmission season due to our temperate climate and the use of window screens in homes than to government mosquito control efforts. Cases of malaria are still reported in the United States among travelers and military personnel returning from abroad. Mississippi has several mosquito species, such as Anopheles quadrimaculatus, that could transmit the disease agent to people should malaria ever become reestablished in our state. Two mosquito-borne diseases, St. Louis encephalitis (SLE) and West Nile virus (WNV) encephalitis, are still serious problems in Mississippi. The last major outbreak of SLE was was from 1974 to 1976 with 331 cases and 42 deaths. There were 247 cases of WNV during an outbreak in 2012. The southern house mosquito, Culex quinquefasciatus, is believed to be the most important vector of these two diseases. This mosquito can be found breeding in drainage ditches and artificial containers around houses. With the elimination of many deadly mosquito-borne diseases from the United States, our control efforts are now mainly aimed at pest mosquitoes rather than disease vectors. However, increasing travel by U.S. citizens into countries where dengue fever and malaria are prevalent and people from those countries immigrating into the United States increase the likelihood of these diseases being reintroduced. Mosquito control continues to be an important program in public health because of the presence of WNV and SLE, as well as the potential for the reintroduction of other mosquito-borne diseases into Mississippi. West Nile Virus Encephalitis In the last two decades, West Nile virus (WNV) has been the primary insect-transmitted disease in Mississippi. WNV is maintained in nature in a bird-mosquito cycle (Figure 2). Several Culex species, including the common house mosquitoes Culex quinquefasciatus (the main vector), Cx. pipiens, and Cx. salinarius, and possibly also Cx. restuans, transmit the agent to people. WNV appears to be most dangerous to elderly or immune-compromised patients, but young people can become ill, as well. Since WNV has been demonstrated to amplify in the Asian tiger mosquito in the lab, it is possible that this mosquito is also involved in WNV transmission. In contrast to other mosquito-borne viruses, WNV may kill birds in the U.S., especially crows, blue jays, and raptors. Therefore, surveillance efforts to detect the presence of WNV can sometimes target reporting and testing of these types of dead birds (although many health departments no longer test dead birds). WNV illness is not as serious as some other arboviral diseases (e.g., EEE, SLE). In fact, only one out of about 150–200 people exposed to the virus will become ill, and less than 10 percent of clinically ill patients will die. Still, the public’s perception and reaction to local reports of WNV cases cause much anxiety and fear in communities. Local officials are then barraged by the public to provide mosquito control to protect them. St. Louis Encephalitis The St. Louis encephalitis (SLE) virus circulates naturally among birds and is transmitted by Culex mosquitoes. Humans can become infected only if bitten by an infected mosquito. Humans are actually “dead end” hosts, meaning that the virus in human blood never reaches a level high enough to infect a biting female mosquito to continue the cycle. Not all people infected with the virus develop clinical disease. However, the virus may produce abrupt onset of fever, nausea, vomiting, and severe headache in humans within 5 to 7 days after being bitten. Fatality rates range from 2 percent to 20 percent, with most deaths occurring in people 60 years of age or older. Outbreaks of St. Louis encephalitis usually occur in midsummer to early fall. Since wild birds and domestic fowl are the reservoirs of this virus, urban areas where large bird populations and abundant Culex mosquitoes are found together are prime sites for a disease outbreak. A major SLE outbreak occurred in Mississippi in 1974–76, with 331 cases and 42 deaths. The threat for this to happen again is real. We need to develop good mosquito control practices in disease-prone areas of our state and be prepared to respond promptly to the next outbreak. Eastern Equine Encephalitis (EEE) As with SLE and WNV, birds are the primary hosts for eastern equine encephalitis (EEE), and mosquitoes, particularly Culiseta melanura, are the vectors from bird to bird. Culiseta melanurararely feeds on humans, though. People usually become involved as dead-end hosts when fed upon by infected salt marsh mosquitoes (Aedes sollicitans), inland floodwater mosquitoes (Aedes vexans), Coquillettidia perturbans, and a few other species. The disease will affect people of any age, with young children and infants being the most susceptible. The mortality rate is over 50 percent, and children surviving the disease often suffer from some degree of intellectual disability or paralysis. Horses are often severely affected by the disease during outbreaks. However, a horse vaccine is available that prevents horse deaths from EEE. In contrast to most other mosquito-borne viruses in Mississippi, LaCrosse encephalitis (LAC) maintains its cycle in nature via a small mammal-mosquito cycle. Usually, the mosquito vector is the tree-hole mosquito, Aedes triseriatus, and reservoirs are squirrels or chipmunks. Control efforts are obviously different for this disease, because it will focus on plugging tree holes where mosquitoes breed in small amounts of acidic rainwater. Mississippi recorded its first confirmed cases of LAC in 1967, but it was not often diagnosed until eight cases were identified in 2001. There have been several cases in our state since then. LAC most often occurs in children younger than 16 and can cause convulsive disorders. These facts bring extra demands from parents to local officials to implement control measures. The Dengue virus can be transmitted from person to person by the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus). Other than humans, no known bird or mammal reservoir exists for dengue. A mosquito can become infected with the virus by feeding on a person with the disease, then the virus must go through an 8- to 10-day incubation period in the mosquito before it becomes infective. The mosquito will then remain infective for the rest of its life. Symptoms include sudden onset of high fever, severe headache, backache, and joint pains. The disease is so painful that it is sometimes referred to as “breakbone fever.” A skin rash may also appear. Infection may be very mild or completely without symptoms. In some areas, however, a complication called “dengue hemorrhagic fever” and “dengue shock syndrome” cause a high fatality rate, especially among children. The disease has been raging in Mexico and Central and South America for the last 20 years and more recently has been found in Florida (mainly in South Florida and the Keys). Chikungunya (CHIK) is a mosquito-transmitted Alphavirus that is not usually fatal but can cause severe fevers, headaches, fatigue, nausea, and muscle and joint pains. It often causes excruciatingly painful swelling of the finger, wrist, back, and ankle joints. The virus was first isolated during a 1952 epidemic in Tanzania; the word Chikungunya comes from Swahili and means “that which bends up,” referring to the position patients assume when suffering severe joint pains. The geographic distribution of CHIK has historically included most of sub-Saharan Africa, India, Southeast Asia, Indonesia, and the Philippines, although the disease is increasing both in incidence and geographic range. There were 266,000 cases on Reunion Island in the Indian Ocean during 2005 and 2006. India suffered an explosive outbreak in 2006 with more than 1.25 million cases. Most recently, there has been a huge outbreak of CHIK in the Caribbean region with at least 1 million cases. A few cases have been reported as locally acquired in the U.S.; therefore, mosquito control personnel should be on the alert for this disease in the southern states. The vectors of CHIK are the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus). Zika virus was first isolated in Uganda in 1947 and was historically transmitted by Aedes aegypti to monkeys. Aedes albopictus is suspected to be a competent vector of the Zika virus, as well. In 1952, it was found in humans in Uganda and the United Republic of Tanzania. From the 1960s to 1980s, it was found in humans on the continents of Africa and Asia. Historically, symptoms were very mild, including muscle and joint pain, fever, rash, headache, and conjunctivitis. However, in 2015 there was a correlation between the Zika virus and microcephaly. Microcephaly in infants can occur when a pregnant woman is infected with the Zika virus. Zika virus retards growth of the fetal brain, resulting in a greatly reduced brain size at birth. Microcephaly usually has a poor prognosis for subsequent neonatal development. There was a large outbreak of Zika in the Americas during 2016 and 2017, and local transmission occurred in Texas and Florida. A 2016 mosquito survey identified no Aedes aegypti in Mississippi but found that Aedes albopictus was abundant statewide; therefore, Zika certainly could be a threat in Mississippi. Dog heartworm is a serious canine disease occurring in the southern U.S. Almost 100 percent of unprotected dogs more than 5 years old are infected. Mosquito vectors that feed on an infected dog take in immature worms (first-stage larvae) with the dog’s blood. The immature worms undergo development within the mosquito, reaching an infective state (third-state larvae) in 9 to 14 days after entering the mosquito. These infective larvae can be transmitted to an uninfected dog when the mosquito feeds. The worms migrate to the dog’s heart and grow into adults. These adult worms produce first-stage larvae that circulate within the dog’s blood and are taken up by feeding mosquitoes to continue the cycle. The southern house mosquito (Culex quinquefasciatus) is the primary vector of dog heartworm in Mississippi, although several other mosquitoes are also involved. At least 61 species of mosquitoes are found in Mississippi. They come in all varieties of size, shape, and color. Many of these species have little impact upon our daily lives because they are rarely encountered by most people. They prefer to feed on blood sources other than humans, or they are not important vectors of diseases that affect us or our domestic animals. Most mosquito programs are primarily concerned with controlling only three or four mosquito species. Every mosquito program in Mississippi targets urban mosquitoes such as the southern house mosquito (Culex quinquefasciatus) and the Asian tiger mosquito (Aedes albopictus). The total list of problem species differs, however, from one section of the state to the other. For example, salt marsh mosquitoes (Aedes sollicitans) are of major importance along the Gulf Coast, while dark rice field mosquitoes (Psorophora columbiae) and malaria mosquitoes (Anopheles quadrimaculatus) are prime concerns in the Delta. Mosquito species differ in their breeding habitats, biting behavior, flight range, and many other characteristics. Therefore, different strategies are needed to control different species of mosquitoes. Yearly town clean-up campaigns, for example, are very effective in reducing populations of Asian tiger mosquitoes that breed predominately in artificial containers (Figure 3). Malaria mosquitoes (Anopheles) usually prefer permanent bodies of water, such as swampy or marsh areas, requiring different control tactics. Therefore, it is vital for mosquito control personnel to know exactly what species of mosquito is found within their area in order to develop an effective control strategy. Mosquito Life Cycle There are four stages in the mosquito life cycle: eggs, larvae, pupae, and adults. Understanding life cycles of target mosquito species is a key step in developing an effective control program. Information on flight patterns and periods of peak mosquito activity helps mosquito control technicians decide when and where to spray in order to kill the most mosquitoes for the money. Those who conduct larviciding will become even more aware of the behavior and biology of the local mosquitoes. They will be encountering the mosquitoes firsthand, visiting their breeding sites, observing their numbers and developmental stages, and gauging the response of the larvae to the larvicide used. Mosquitoes can be divided into roughly three major breeding groups: permanent water breeders, floodwater breeders, and artificial container/tree hole breeders. Anopheles and many Culex mosquitoes select permanent water bodies, such as swamps, ponds, lakes, and ditches that do not usually dry up. Floodwater mosquitoes lay eggs on the ground in low areas subject to flooding. During heavy rains, water collecting in these low areas covers the eggs, which hatch from within minutes up to a few hours. Salt marsh mosquitoes (Aedes sollicitans), inland floodwater mosquitoes (Aedes vexans), and dark rice field mosquitoes (Psorophora columbiae) are included in this group. Artificial container/tree hole breeders include yellow fever mosquitoes (Aedes aegypti), Asian tiger mosquitoes (Aedes albopictus), tree hole mosquitoes (Aedes triseriatus), and cannibalistic mosquitoes(Toxorhynchites rutilus). Several species of Anopheles and Culex may also occasionally oviposit in these areas. Aedes species lay eggs on the walls of containers above the water line; they are flooded when rains raise the water level in the containers. Other species oviposit directly on the water surface. Female Anopheles mosquitoes generally lay eggs on the surface of the water at night. Each batch usually contains 100–150 eggs. The Anopheles egg is cigar-shaped, about 1 millimeter long, and bears a pair of air-filled floats on its sides. Under favorable conditions, hatching occurs within 1 or 2 days. Other Aedes mosquitoes lay their eggs on the moist ground around the edge of the water. When these eggs are first laid, they will die if they become too dry. However, after the embryo in the egg develops, the eggs can withstand dry conditions for long periods of time. This trait has allowed Aedes mosquitoes to use temporary water bodies for breeding, such as artificial containers, periodically flooded salt marshes or fields, tree holes, and storm water pools. Aedes mosquitoes have been carried to many parts of the world as dry eggs in tires, water cans, or other suitable containers. The Asian tiger mosquito (Aedes albopictus) was introduced into the United States in shipments of used truck tire casings imported from Taiwan and Japan in 1985. A few years later, this mosquito was probably brought into Gulfport, Mississippi, in truck tire casings bought from a Texas used tire dealer. Once these tires were stacked outside and began to collect rainwater, the eggs hatched. Now the Asian tiger mosquito is found statewide, but especially in tire piles (Figure 4) and vases at cemeteries (Figure 5). Psorophora mosquitoes also lay eggs capable of withstanding dry conditions. These mosquitoes are often a major problem species in rice fields. Eggs are laid on the soil and hatch once the field is irrigated. Culex mosquitoes lay batches of eggs that are attached together to form small, floating rafts. On close inspection of a suitable breeding site, these egg rafts can often be seen floating on the surface of the water. Large numbers of egg rafts indicate that a large population of larvae will be hatching out within 1 or 2 days. This information will help the larvicide technician decide what action to take to control the potential mosquito problem. Mosquito larvae are air breathers and, therefore, must come up to the surface periodically for oxygen.Anopheles larvae breathe through a pair of openings called spiracles on the end of the abdomen. Culex and Aedes larvae have air tubes on the end of the abdomen. Anopheles larvae lie parallel to the water surface, supported by small, notched organs on the thorax and clusters of float hairs along the abdomen. Culex and Aedes larvae hang from the surface film with their heads pointed downward (Figure 6). Larvae feed either by slowly sweeping surface bacterial film toward the mouth, using a pair of mouth brushes, or by moving backward and forward through the water to produce a current just below the surface that flows toward the mouth. They generally feed on smaller particles, rejecting the larger ones. To be effective against Anopheles larvae, a larvicide must remain on the surface of the water for a long period, and the particles of the larvicide must be small enough to be accepted by mosquito larvae. Mosquito larvae undergo molts (shedding of the outer skin) and have four different larval stages (or instars). These skins can often be seen floating on the surface of the water. The thick head capsule “hardens” shortly after the molt, becoming non-elastic. Therefore, larvae must shed the old skin so that they can grow. During each molt, the head of a larva will swell, increasing in width by about 50 percent. The period between molts is called an instar. The final (fourth) instar, when larvae have reached their largest size, is the stage used for species identification. Larvicide technicians should be careful to include these fourth-instar larvae in collections that are to be immediately identified. Otherwise, larvae must be allowed to molt into fourth instars. The larval stage will last from 7 to 10 days under optimum conditions for many mosquito species. Fourth instars will then molt into pupae. While resting, pupae float at the surface of the water. Pupae do not feed and, therefore, are not affected by larvicides that must be eaten. (However, surface film larvicides are effective for pupae.) Pupae must come to the water’s surface to breathe through their two respiratory tubes (trumpets). Generally, pupae will lie still, floating at the surface. If disturbed, they swim forward or dive to the bottom by rapidly flexing their abdomens that are equipped with two paddles. The pupal skin splits along the back and an adult mosquito emerges. This is a critical stage in mosquito survival. Should the emerging adult fall over while leaving its skin, it will become trapped on the water surface and die. The newly emerged adult mosquito must dry its wings and separate and groom its head appendages before it can fly away. Mosquito Breeding Sites Just about anything that holds water will breed mosquitoes. Old washing machines, boats, horse troughs, steel drums, cisterns, plastic containers, glass bottles, and aluminum cans are just a few examples of artificial containers where mosquitoes are found. Used tires make excellent mosquito breeding sites, and tire piles are a tremendous problem for towns and cities (Figure 4). They usually hold water, and the dark, rough inner wall is an ideal egg-laying surface for species such as the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus). Finding ways to properly dispose of used tires is one of the most difficult problems facing mosquito control agencies today. Buried tires hold air. Unless whole tires are buried very deeply in landfills, they will work their way back to the surface. Whole tires also take up valuable landfill space. Therefore, many landfills will not accept used tires or will charge several dollars per tire to take them. As a result, many tires are being illegally dumped in wooded areas, vacant lots, gullies, and other secluded sites. Often, local mosquito problems can be traced to one of those hidden tire piles. Shredding tires into small pieces before disposing of them in landfills seems to be one of the best answers to the problem. However, tire shredding equipment is expensive. Very few cities or counties can afford to purchase and operate shredders or lease the services of shredder companies. Mississippi has a law governing the storage and disposal of old automobile tires. Mayors and aldermen can direct any questions they have about cleaning up tire piles to the Mississippi Department of Environmental Quality, Solid Waste Division. Ideally, used tires should be stored under a rain shelter. A mobile tire shredder can then be brought in to grind up stockpiles of tires on-site, and then the shredded tires can be properly land-filled. Newer approvals have been granted for using tire chips on-site for sewage field lines. Alternatively, tires may be cut in half and stacked outside with the curve facing upward to prevent the collection of water. A temporary solution is to stack used tires in an open, secluded area of the landfill. Although these tires will still breed mosquitoes, the problem will be much easier to control than if tires were scattered in hidden piles throughout the town and surrounding countryside. Measured success in controlling tire-breeding mosquitoes has been shown using granular Bacillus thuringiensis israeliensis (Bti). The granules can be broadcast over tire piles with seed or fertilizer spreaders or specialized backpack sprayers (Figure 7). Many granules will fall down into the tires where mosquitoes breed. Penetration in piles up to six tires deep has been obtained. Some types of artificial containers cannot be disposed of or removed because they serve some useful purpose. In these situations, mosquito breeding must be controlled by applying Bti or other suitable larvicides or by preventing adult mosquitoes from entering these containers and laying their eggs. For example, cisterns used to collect rainwater should have well-screened tops. Small-animal watering pans should be emptied and cleaned at least weekly. Livestock watering troughs should also be drained weekly if mosquito breeding is found or larvicided with methoprene products. Bti can be applied to many types of artificial containers that are not used as sources of drinking water, such as water gardens and vases in cemeteries. Tree holes provide breeding sites for a variety of mosquitoes. The major species is the tree hole mosquito (Aedes triseriatus). Parks and hardwood stands in towns can be surveyed for tree holes and marked on habitat maps. These holes can be treated with Bti, sealed with a tree patch material, or filled with sand. Water Drainage Systems Water drainage systems that carry rainwater out of towns and cities are both manmade and natural. Culverts, storm drains, and roadside ditches that become clogged, allowing water to pool, will become mosquito-breeding areas. Keeping these areas cleaned out, removing weeds and silt, will help prevent mosquito problems. This is particularly true for those areas that hold water for a week or two after a rain but are dry during other times. Such areas will breed floodwater mosquitoes but will not hold water long enough for large populations of natural mosquito predators to become established. Ditches that always hold water may have populations of fish, beetle larvae, dragonfly larvae, and other organisms that feed on mosquitoes. These predators help keep mosquito populations under control. If these ditches are cleared out, eliminating natural communities of predators, a mosquito problem may develop in an otherwise non-problem site. Mosquitoes will be among the first organisms to return to the pools that form in a cleaned-out ditch following a rain. In the absence of predators, the mosquitoes will develop undisturbed unless closely watched by the larviciding technician. Use a dipper to sample ditches to determine the number of mosquito larvae and pupae living there. Collect samples along the edges of pooled areas, especially around clumps of weeds and in shaded areas. Also look for predaceous fish and insects living in the ditch. One or two mosquito larvae per dipper may not be a problem, especially if large numbers of predators are found. If large numbers of mosquito larvae are present, the site will need to be treated with Bti, methoprene, or surface oils/films to help the natural predators maintain control of the mosquito population. These larvicides will kill mosquito larvae without affecting the other organisms. Natural permanent water drainage areas should be inspected and treated as described for permanent water ditches. Disturbing these natural areas may result in more problems than will be solved. Major mosquito problems will often be found in ditches that are polluted with discharge from malfunctioning septic tanks. The southern house mosquito (Culex quinquefasciatus) prefers a breeding site polluted with sewage. These mosquitoes are very important vectors of SLE and WNV in our state. Ponds, Lakes, and Lagoons Generally, well-maintained ponds and lakes produce very few mosquito problems. Large numbers of fish and other mosquito predators are usually found in these sites. Keeping weeds mowed around banks of catfish ponds, sewage waste lagoons, and lakes will help prevent mosquito breeding. If mosquito breeding is found at these sites, it will probably be along the marshier side of the water body. The area around the dam end is usually too steep to provide suitable mosquito breeding habitats. Marshy areas can be treated with Bti or other larvicides as needed. Marshes and Swamps Swamps are permanent water habitats that produce Anopheles, Culiseta, and other permanent water-breeding mosquitoes. Freshwater marshes, especially those that have temporary flooding, will often yield species such as the inland floodwater mosquito (Aedes vexans). Salt marshes are breeding sites of the salt marsh mosquito (Aedes sollicitans). Marshes and swamps are large areas to treat and may require larvicide application by plane or boat. Smaller sites can be covered by ground. Formulations of Bti and methoprene have proven to be very successful in these areas. Surface films or oils such as Golden Bear®, CoCoBear® or Agnique®, which form a film over the water and prevent larvae from breathing (without hurting other predators) are another larvicide option if vegetation is not too dense. The area that must be treated varies depending upon the flight range of the problem mosquito species. Generally, mosquitoes breeding in swamp areas do not range far. Salt marsh mosquitoes, on the other hand, have a flight range of up to 20 miles. A town should be surveyed following a heavy rain in order to locate sites where floodwater collects. These sites should be recorded on habitat maps. Floodwater areas are temporary water sites and, therefore, usually do not contain large numbers of natural predators. Accordingly, these sites will breed several species of floodwater mosquitoes if water remains for a week or longer. Such areas should be treated a few days after a rain and closely watched for mosquito breeding. Once these areas are known, they can be pretreated with a residual larvicide that will take effect once water is present and provide control for up to 30 days. Rice fields can produce major mosquito problems in many areas of Mississippi, especially in the Delta. The malaria mosquito (Anopheles quadrimaculatus) and the dark rice field mosquito (Psorophora columbiae) are two of the most difficult species to control in the Delta. The dark rice field mosquito can fly at least 5 miles, making control difficult. These floodwater and rice-inhabiting mosquitoes’ breeding cycles are determined by the rice irrigation cycle. Methods have been developed to apply Bti inexpensively to rice fields either at the point of water inflow or aerially with ultra-low-volume machines. Rice field mosquito control requires a cooperative effort among rice growers and city and county agencies. Purpose of Mosquito Surveillance Mosquito surveillance should be a routine part of any mosquito control program. A good surveillance program will provide two types of information: 1) a list of the local mosquitoes (including distribution and population size estimates) and 2) the effectiveness of the control strategies being used. Routine surveillance can keep control personnel informed about locations of major breeding areas, helping identify problem sites where control should be concentrated. Carefully interpreted survey data can provide vital information. For instance, large numbers of Culex egg rafts around the edge of ditches or Aedes eggs on oviposition strips are indicators that these breeding sites should be watched closely for the next few days. Treatment should be timed to catch the heavy crop of resulting larvae during the period of their life cycle when they are active feeders. Large catches of adults in light traps stationed near treated areas may indicate that an important breeding site has been overlooked in the survey or that mosquitoes are migrating in from other areas, depending upon the species captured. Mosquito Surveillance Network Many municipal and county mosquito control agencies do not have the facilities or personnel available to identify mosquitoes, but the Mississippi State Department of Health and Mississippi State University have entomologists who can help confirm field identifications. Local mosquito control agencies can collect mosquitoes using methods described below and send samples to MSU or the health department. Entomologists will identify the mosquito sample and send results back to the local mosquito control agency. Mosquito control technicians or directors can consult this manual or entomologists to determine what control tactics to use to control the problem species. Eventually, however, this type of decision will become second nature to mosquito control personnel. Fixed light traps (such as New Jersey light traps, discussed below) can provide mosquito controllers with valuable information on adult mosquito populations. Mosquito control agencies on the Gulf Coast routinely station permanent light traps in the backyards of people living in mosquito-prone areas throughout the city. These individuals sometimes are enlisted to help maintain the traps, collect the mosquitoes after each sampling, and mail the samples to the mosquito control agency. Operational expenses can be reduced by locating light traps at fire stations, city or county barns, or other facilities where they can be easily maintained. As an alternative, mosquito surveillance programs and even larviciding activities offer excellent summer employment opportunities for local students. Students can be an economical, seasonally effective labor force; in return, the students gain experience in an applied aspect of biology, ecology, public health science, vector control, and municipal management. Personnel at Mississippi State University or the Mississippi State Department of Health can provide annual training programs (with appropriate advance notice) on mosquito control and surveillance techniques. Mosquito Egg Surveys Oviposition cups/jars are useful tools for collecting information on many container-breeding mosquitoes, such as the Asian tiger mosquito (Aedes albopictus), the yellow fever mosquito (Aedes aegypti), and the tree hole mosquito (Aedes triseriatus). Counting eggs collected from an ovitrap will give a good indication of the number of Aedes larvae that will hatch in an area following the next rain. Some eggs can be quickly identified to species, or at least genus, under a microscope. Also, eggs can be hatched in the lab to confirm species and be tested for such things as insecticide resistance. The oviposition jar should be a black plastic or glass jar, or even an aluminum can with the top cut out and painted black. Fit the oviposition jar with a strip of felt-covered paper or other stiff paper (“egg paper”) clipped to the side (Figure 8). Fill the jar about halfway with water. Female mosquitoes are attracted to both the black jar and the water, and they will lay eggs on the rough surface of the strip just above the water line rather than the smooth surface of the jar. A hole punched in the side of the jar about 2 inches from the rim will prevent water from flooding the eggs during heavy rains, thereby causing many of them to hatch. Some mosquito control districts attach oviposition jars to both sides of a piece of white-painted board. This arrangement reduces the chance of oviposition jars being turned over, and, also, the contrast of black jars against the white board seems to attract mosquitoes more readily. Most of the equipment required to conduct a larval surveillance program can be purchased in a local hardware store. A white plastic or metal dipper (Figure 9) is excellent for collecting water from artificial containers and small water bodies that are easy to reach. Larvae can then be gathered from the dipper with a medicine dropper, pipette, or meat baster and placed in a small jar, containing a little water, to be preserved later. Companies that supply mosquito control equipment sell long-handled, white, graduated dippers. These are useful for sampling ditches, margins of lakes and streams, and hard-to-reach areas. Kitchen strainers and fine-mesh aquarium nets are also good for collecting large numbers of larvae. Wash the contents of the net or strainer into a white enamel or plastic pan, and remove the large larvae with a medicine dropper. Large meat basters are ideal devices for getting samples from tree holes or artificial containers with restricted openings. Three- or four-foot sections of plastic tubing can also be used to siphon large amounts of water from tires and other similar breeding habitats. Place the end of the siphon in a strainer or large, white pan to catch the larvae. A flat-weighted metal can with a string attached is an essential tool for collecting samples from storm drain ports protected by heavy metal gratings. Keep descriptive information (date, specific location, habitat description) for each larval sample collected. Accurate descriptions of habitats sampled, including those places where no mosquitoes are found, are important. Having a good understanding of the type of local areas that breed mosquitoes can make future routine surveys more efficient (concentrating on those areas that are known breeding sites). However, personnel should conduct a thorough survey of all water areas occasionally to ensure that previously unproductive areas have not become mosquito breeding sites. Estimate population densities of larvae by counting the number of larvae per dip, using a standard-size dipper. Take and count three to five dips at each site. Record the number of dips counted and number of larvae in each dip. Also record information on the life stage of larvae and pupae. Noting numbers of larvae in each instar or size category (small, 0–5; medium, 5–15; large, 15+), number of pupae per dip, and water temperature can help the investigator make an educated guess as to when mosquitoes will emerge and what control efforts should be used. Generally, larvae develop faster at higher temperatures. Large numbers of pupae indicate that a large number of adults will emerge within a few days. Since pupae do not feed, Bti or other products that must be eaten by mosquitoes will not control them. On the other hand, if most larvae are small, it may be 8–14 days before adults emerge, depending on the species and the temperature. In this case, an application of Bti may be suitable. Large numbers of pupal skins floating on the surface is a sign that adult mosquitoes have recently emerged. Experienced investigators will be able to determine the genus of many larvae based upon a few key characteristics. This knowledge will be useful in selecting the right larval control agent. For example, Bacillus sphaericus (another bacterial larvicide) is highly effective on Culex mosquitoes but not Anopheles mosquitoes. Carefully handle mosquito larvae collected for identification. If handled roughly, distinguishing scales and other structures may fall off or become damaged, making identification difficult or impossible. Remove larvae that are to be preserved from the pan or dipper with a large-tipped medicine dropper. Place these larvae in a small jar containing water and label and carry it back to the office. Adult mosquito surveillance is a very important part of any mosquito program. Adult surveillance will provide information on the effectiveness of the larvicide program. However, the presence of some adult mosquitoes does not mean that larviciding efforts are not working. No program will totally eradicate mosquitoes. The objective is to control mosquito populations, keeping their numbers at an acceptable level. Also, several species, such as the salt marsh mosquito (Aedes sollicitans) and the dark rice field mosquito (Psorophora columbiae), are capable of flying long distances and can move into an area from distant breeding sites. Information gained from routine adult mosquito surveillance includes: - Checklist of adult mosquito species in the local area. - Estimate of adult mosquito population density and distribution over time. - Indication of the presence of breeding sites that were overlooked. - Identification of sites where larviciding efforts need to be increased. - Source of adult female mosquitoes that can be used in encephalitis surveys. The equipment needed to collect adult mosquitoes is generally more complicated and expensive than that required for collecting larvae. Adult mosquitoes are very fragile. They readily lose legs, scales, and wings when handled roughly, making identification difficult or impossible. The special collection equipment described below is designed to capture adult mosquitoes with minimum damage. Daytime Resting Stations Adult mosquitoes, especially Anopheles, can be found during the daytime resting in both natural and artificial shelters. These areas include houses, barns, sheds, bridges, culverts, hollow trees, overhanging cliffs, and foliage. Counts of mosquitoes using daytime resting shelters can give a good indication of population density. Mosquitoes found in these shelters can be easily collected with an aspirator (Figure 13). In areas where no natural resting shelters are found, artificial resting stations, such as wooden boxes, can be constructed and placed outdoors. Many mosquitoes that do not usually bite can be collected in this way. Several types of light traps are commonly used. The CDC light trap, developed by the Centers for Disease Control, is a portable model that is widely used (Figure 10). This light trap runs on a 6-volt, rechargeable battery; a smaller version uses two D cell batteries. Mosquitoes are attracted to a small light at the top of the trap and are then sucked by a fan into a net at the bottom of the trap. The traps are usually set out and turned on at dusk and picked up early the next day. Timing devices can be installed on the traps so that they will only run during those hours of peak mosquito activity, conserving batteries. Light traps attract only selected species of mosquitoes, and catches tend to be smaller during a full moon. To increase mosquito catches, hang a container of dry ice or an octanol lure near the light trap. The New Jersey light trap is a larger metal device, usually located at a permanent sampling station (Figure 11). This trap is often equipped with a timing device that turns it on during selected hours on certain days of the week. It works on the same general principal as the CDC light trap, except that it uses 110 AC power, and mosquitoes are sucked into a paper cup inside a jar containing a killing agent such as a piece of Vapona pest strip. The paper cup prevents mosquitoes from coming into direct contact with the pest strip. Generally, New Jersey traps require little maintenance. This trap will attract many different types of insects along with mosquitoes. If no insects are caught in the trap, it could be due to loss of power, a timer that needs to be reset, pest strips that have lost effectiveness, or a non-working light bulb, or the trap may need to be cleaned. The inside cone can be cleaned with a bottle brush. At least once per year, clean the entire trap with a degreasing agent to maintain efficacy. Oviposition or Gravid Traps Oviposition traps or gravid traps (Figure 12) are available through some supply companies. These devices are similar to oviposition jars in that they include a black plastic container partially filled with water as an attractant. Female mosquitoes visiting the trap to lay eggs are sucked into a net by a small fan motor like those used on many light traps. Oviposition traps are very selective for female Culex mosquitoes, and, thus, the catch data is not comparable to light trap data. These traps are not commonly used by mosquito control agencies. These traps are a good tool if a mosquito control program needs to test mosquito populations for encephalitis viruses such as SLE and WNV. Culex females can be sent to the Mississippi State Department of Health for WNV testing. Preserving Adult Mosquitoes Adult mosquitoes can be mailed to an entomologist for identification. Handle them very carefully so they don’t lose scales, legs, or wings. Mosquitoes taken from a New Jersey light trap using a pesticide strip in a killing jar are usually dead in the perforated paper cup. Shake these mosquitoes gently from the cup into a small, tissue-lined cardboard jewelry box or similar container. Arrange mosquitoes evenly over the tissue, one layer deep. Place a piece of tissue on top of the mosquitoes to prevent them from being shaken about. Place a label containing the necessary sample information (date, specific location, and name of collector) on top of the last layer of tissue and secure the lid on the box with a rubber band. Use one box per sample. If many mosquitoes are captured in a single trap, use extra boxes to hold the sample and bind these boxes together with a rubber band. Use a manual or battery-operated aspirator to remove mosquitoes from net bags of light traps (Figure 13). An alternative is to remove the net bag, tie the top, and place it in an airtight container (such as an ice chest) with an open bottle of chloroform. Another option is to use ice or frozen reusable ice packets to cool down adult mosquitoes in an ice chest until back at the lab where they can be placed in a freezer. Shake dead mosquitoes from the net bags onto a piece of paper or into a small pan, and then transfer them to a small collection box. Do not handle adult mosquitoes, if possible. When necessary to pick them up, use a pair of forceps, grabbing each mosquito gently by a group of legs. To deliver mosquitoes to an entomologist, place the collection boxes in a larger, sturdy container and fill loose spaces around the collection boxes with paper or packing peanuts. Secure the lid carefully and mark the container “fragile.” As an extra precaution, place a wisp of cotton on top of the upper tissue layer of each collection box. This will help keep the mosquitoes from being shaken around inside the collection boxes. These steps may seem a little extreme, but the identifying entomologist needs good-quality samples for accurate identification. This is especially important when initially collecting adults from an area and compiling a reference collection and species list. Habitat Mapping and Record-Keeping Habitat maps and records of mosquito populations and application methods used are valuable sources of information to the larvicide technician. This section describes one method of mapping and keeping records of mosquito breeding activities. Mosquito control personnel can make improvements and variations on this method or devise their own methods. A habitat map should show all known water areas within a town, including artificial containers and floodwater areas. In the beginning of the larvicide program, record all known water areas on quarter-mile quadrants of a town street map or aerial photograph. Keep a list of GPS coordinates for these locations. Break down habitat maps by zones or areas. Another easy way to do this is using the existing voting district zones. The best way to conduct a habitat survey is by foot, inspecting each site for evidence of mosquito breeding. This ensures a thorough inspection and allows the inspector to become familiar with the area. Record both mosquito-positive and mosquito-negative sites. Distinguish positive sites from negative sites by placing a small star () next to those sites where mosquitoes were found. Record water sites by type, using a numerical code. Later, when making routine larviciding rounds, the technician can determine locations and types of water habitats in an area at a glance. He or she will then know which of these sites were positive during the initial survey. Verify habitat maps during the first couple of larvicide applications. Add newly discovered sites to the maps and list of GPS coordinates. Check locations of ditches, storm drains, and tree lines. When the technician feels comfortable with the accuracy of the maps, make photocopies and keep the master copy on file. During each larviciding trip, use a set of these copies as field maps. Record notations concerning the day’s activities on each quadrant as you visit each site. Keep maps showing each week’s activities on file for future reference on mosquito breeding trends. Keep a chart divided into zones in the office, where technicians can mark which sites were inspected and larvicided. Some people choose to laminate each quadrant map. During routine visits to breeding sites, the technician can make notations on these maps in grease pencil. Keep these maps in a metal clipboard with a cover to prevent smudging the grease pencil. Transfer the information from the laminated maps to regular copies and file them for future reference. Keeping records on each site can be useful. Knowing information such as previous larvicide treatments, past estimates of mosquito numbers, life stages found, and when a site was wet or dry allows the technician to predict when a particular site will become a problem. This information can be useful in other ways. Many vector-borne diseases occur in cycles. Breeding trends of local mosquito species over the past few years may indicate the likelihood of a disease outbreak. Any advance warning of a potential epidemic would allow mosquito control technicians to take precautions such as larviciding an area more frequently or, if necessary, spraying adult populations with an adulticide. Complaint calls can be an important part of both mosquito surveillance and mosquito control. The public can provide a valuable service by calling in mosquito problems. Complaint calls can help pinpoint large populations of mosquitoes. Spray efforts can be aimed at these “hot spots” when needed, rather than spraying the entire town. This is an important component of integrated pest management (IPM). Encourage community members to notify their local mosquito control agency when mosquitoes get out of hand. Plot the complaint calls with a computer or on a large map to provide information on probable areas to target. If possible, turn complaint calls into service requests. Gather as much information as possible over the phone, including the name, address, and phone number of the caller, time of day or night the mosquitoes are biting, and areas of standing water that the resident may know about. You might also choose to conduct a landing rate survey, where the inspector stands still for 2–5 minutes and records how many mosquitoes land on him or her. When possible, arrange an inspection when the resident is home. This is a good opportunity to educate the homeowner on mosquito biology and control, source reduction, and personal protective measures. Plan on collecting adult mosquitoes or have the resident save a few. This will help identify the species and locate the breeding source(s). Conduct a thorough inspection of the yard and adjacent yards. Talk with the resident during the inspection and collect samples as you inspect. Taking the time to educate residents will help to reduce the number of call-back inspections. Try to empower the homeowner. Leave literature on mosquito control and offer sound suggestions and advice. Getting residents to change their behavior can help eliminate neighborhood mosquito problems. Record the date, location, density, stage of mosquito development, and habitat. Save a sample for identification and create a breeding site record in an Excel spreadsheet for locations that will need regular monitoring and treatment. Include information on adult mosquito rates encountered and the decided treatment. Keep the information in a file system for rechecks and control activities, historical information, and legal purposes. Also, note on the service request the time, date, action taken, and initials of the technician. This will be helpful information to have in case a citizen states that no action was taken to control mosquitoes in their area. The best mosquito control program is an integrated program that includes point-source reduction of breeding areas, routine larviciding in those breeding areas that cannot be eliminated, and adulticiding only when necessary. In this present day of environmental consciousness, municipal leaders must try to use integrated methods of mosquito control and not just routine spraying with a fogging truck. Routine spraying can lead to insecticide resistance and inability to control mosquitoes when control is most needed. The first phase in any mosquito control program may be to organize something like a spring cleanup campaign. Picking up and hauling away all rubbish piles, broken-down washing machines, junk cars, and bottles and cans from around houses will eliminate many domestic mosquitoes that breed right in our backyards. Activities such as cleaning out clogged street drains and culverts, cleaning up illegal dump sites, and mowing around sewage treatment lagoons will also eliminate many mosquito breeding sites. These efforts will save time and money that would otherwise have to be spent controlling mosquitoes breeding in these sites. Wetlands are considered valuable resources. Therefore, many areas where mosquitoes breed cannot or should not be eliminated or altered. Mosquitoes breeding in permanent water areas or temporary floodwater areas can be controlled by using biological larvicides. Larvicides such as Bti will effectively control mosquito larvae when applied as needed, without killing the mosquitoes’ natural predators. Permanent water areas generally harbor many species of fish and insects that feed on mosquito larvae. Altering drainage ditches will often destroy these natural predators, allowing mosquitoes to breed unchecked as soon as water pools up again. A good adulticiding operation should be a backup system, used when mosquito populations have gotten out of control for some reason or another. Maybe local breeding habitats formed after heavy rains were overlooked by the larviciding technician. Also, an unseasonable emergence of mosquitoes may occur during a spell of warm weather, after a natural disaster, or if an encephalitis outbreak occurs. These situations may require the use of an adulticide to contain the problem. If the spray truck has been parked, being used only when necessary and properly maintained, then the program manager can feel confident that the chemical will be fast and effective, encountering no problems with resistance among mosquito populations. Integrated Pest Management (IPM) Mosquitoes, like any other pests, are best controlled by a combination of pest control methods. This IPM approach saves money by reducing the amount of pesticides used and helps protect people and the environment from unnecessary pesticide exposure. IPM for mosquitoes: - Surveillance and Sampling - Source Reduction The order of implementation is very important. Cities, towns, or even homeowners should never begin their mosquito control efforts by adulticiding, or even larviciding. Control efforts should begin with education, including identifying the local mosquito species (to know what’s out there). Help with mosquito identification is generally available from the Mississippi State Department of Health and the Mississippi State University Extension Service (Figure 14). Education also means providing information to the public about where mosquitoes breed, how people can prevent mosquito breeding, and personal protection measures against them. Surveillance is vital to community mosquito control because it tells mosquito control personnel when the problem is bad enough for spraying. Surveillance helps justify the use of pesticides around homes, people, and the environment. Source reduction simply means finding and eliminating places where mosquitoes breed. This can be anything from old cans and tires around the house to low spots in the yard or poorly flowing ditches. Larviciding is placing chemical or other products into water sources (or dry areas that will eventually hold water after rainfall) to kill mosquitoes in the larval (immature) stage. Some larvicides are relatively safe to people and the environment, while others are traditional chemical pesticides. Adulticiding is spraying a fine mist into the air to kill adult mosquitoes. These days, most adulticiding is carried out with ultra-low-volume (ULV) machines that apply only about 1–6 ounces of pesticide per acre. The first step in controlling mosquitoes is source reduction, or eliminating mosquito breeding sites. Reducing the amount of breeding areas in a town will save the larviciding technician both time and work. A spring cleanup drive involving schools, citizen groups, and town maintenance and public works departments can help get rid of bottles, cans, tires, stagnant drainage ditches, and other sites that produce mosquitoes. Many types of breeding sites, however, cannot or should not be eliminated. Mosquitos in these areas will have to be controlled by applications of a suitable larvicide. Improper drainage of wetlands and indiscriminate ditching can create more mosquito problems than were there to begin with (plus, draining wetlands is illegal in many jurisdictions). Many organisms have been or are being evaluated as potential biological control agents for mosquitoes. A few of these agents have been used to control mosquitoes for years. The World Health Organization has used the mosquito fish (Gambusia affinis) in many parts of the world since the 1940s. Toxorhynchites rutilus, a mosquito that is cannibalistic during its larval stages, is also used in mosquito control. Females of this species do not take a blood meal, so once they become adults, they are not a nuisance or public health risk. A nematode parasite (Romanomermis culicivorax) was at one time commercially available and has been used in many areas for mosquito control with measured success. Each biological control agent has certain merits and restrictions. In order to use a biological control agent successfully, the larvicide technician must have a basic knowledge of the biology of each agent used. Some biological control agents are limited by salinity, temperature, or organic pollution. Further, all these agents differ in the ways in which they can be formulated, transported, stored, and applied. All of these factors must be considered when choosing the proper biological control agent for a specific habitat or to control a specific mosquito. Larviciding, or killing the mosquito while in the larval stage (pupal stage included), is one of the most common methods of mosquito control used today. It is considered the best course of action for mosquito control after source reduction. When mosquitoes are in their immature stages, they are concentrated in a relatively small or fixed area. The kill occurs before mosquitoes are out flying around, causing biting nuisances, and capable of transmitting diseases to people, pets, and domestic animals. However, every place with standing water need not be larvicided. Several factors must be considered before larviciding. These include the mosquito species, larval density, stage of development, relative proximity to populated areas, size of the area, seasonality, susceptibility, equipment and larvicides selected by the program, the larvicide formulation, environmental issues, jurisdiction, rain and wind conditions, and cost. The best pesticide is one that is extremely specific, affecting only the target pest and nothing else in the environment. It must eliminate the pest quickly before it becomes a threat and before it reproduces. It has to be easily applied, reasonably inexpensive, and nontoxic to humans, domestic animals, and wildlife. Finding all of these characteristics in a single pesticide has been the goal of many researchers. A small group of Bacillus bacteria have been developed into a line of pesticides (Bti and related compounds) that are remarkably close to this idealistic model. Some manmade chemicals like methoprene, Golden Bear®, and Agnique® also will prevent the adult mosquito from forming while not harming natural organisms or the environment. Bti is a strain of bacteria that was isolated from a dead mosquito larva found in Israel in 1977. It proved to be very effective at killing mosquito larvae and black flies. It was also lethal to several species of midges, but had no adverse effects on other insects, fish, or laboratory animals. Bti has since been developed into wettable powder, liquid, granular, capsule, and briquette formulations that are commercially available to mosquito control personnel. It has also been formulated with growth regulators and monomolecular films. The wettable powder formulation is not widely used. The liquid, however, is one of the most common and versatile formulations on the market. Liquid Bti is packaged in 2.5-, 5-, and 30-gallon containers and costs about $70 per gallon. It generally comes in two strengths, 600 and 1,200 international toxic units. This material can be mixed with water and applied by hand sprayer, truck-mounted sprayer, or ultra-low-volume spray machine. The portable hand sprayer provides the best way to apply Bti to many urban breeding sites. It is important to purchase a sprayer that is comfortable and easy to carry for several hours. Consider sprayers equipped with backpack or shoulder straps (Figure 7). The spray unit should hold 2–4 gallons and be equipped with a wand with an adjustable nozzle. These backpack sprayers can range in cost from $200 to $600. Truck- or ATV-mounted larvicide sprayers (polytanks) can also be used. They cost around $300 and run from a battery supply or can be outfitted to get their power from the truck. Make sure you cover the water surface when applying Bti. A soft, sweeping mist coverage is better than a strong stream. Bti spores are effective when they are on the surface where larvae generally filter feed. If the water is churned up by spraying a hard stream of material, many spores may sink rather than remain at the surface. Be sure to spray in shallow water around grassy edges and shaded areas where larvae tend to concentrate. Label application rates for liquid Bti are based on the surface area of the water being treated, not depth. Application rates of 0.5–2 pints per acre are generally recommended, depending on the strength of the formulation used (check the label for specifics). The proper rate needed at each site depends on several factors, including predominant larval stage, larva density, water quality, type of water habitat, and amount of plants growing in the water. Early-stage larvae are more readily killed by Bti than late stages. Lower dosage rates can be used when larva are mainly early stages, but the higher recommended dosage is needed for populations of late third and fourth stages. The higher the concentration of spores at the surface, the greater the likelihood that the older larvae will pick up a few spores. Bti is less effective against the late instars; plus, pupae do not feed, so they are not affected by Bti unless they fed on it before pupating. Methoprene, however, is very effective against the fourth-stage larvae, as is Agnique® (not an oil) and some oil products that spread out over the water surface, suffocating the larvae. If only pupae are present, Bonide® and Golden Bear® are options. At that point, it is too late to use Bti or methoprene, and a quick kill is needed. The residual effect of most oil formulations for killing late-stage instars and pupae is about 5–7 days. Younger larvae will be feeding actively for a week or more and, therefore, have plenty of opportunity to ingest a few Bti spores, even when applied at the lower dosage rate. Use the higher application rate when larval population density is high, regardless of predominant instar present. Mosquito larvae are very efficient filter feeders. Large numbers of larvae will quickly filter out all of the spores applied at low rates before all larvae have a chance to feed on the material. In areas with water polluted with septic tank discharge or in water with a heavy growth of algae, use higher rates of Bti, or even switch to a related product calledBacillus sphericus. These waters generally have higher concentrations of suspended food particles. In this case, Bti spores are competing with food particles. Using the higher dosage rate increases the chance that larvae will pick up at least some of the spores along with all of the food particles. Lower dosage rates can be used in clear, open waters (ponds, pools, rice fields, floodwater), but use higher dosage rates in heavily shaded water. Granular Bti is generally applied to areas covered by thick vegetation, such as salt marshes and weedy ditches. It has also been used in flooded pastures, irrigated fields, and tire piles. If granules are applied to large areas of open water, winds can push them against one shore. This formulation consists of spores attached to a carrier made from ground corn cob particles. The carrier floats, keeping much of the material at the surface where most larvae feeding occurs. Different companies make different sizes of corn cob particles. As a rule, smaller particles can fall through thick grass better but may be more likely to stick to wet blades. Larger granules can be broadcast farther and are less affected by wind. Make ground applications of granular Bti with manual or mechanical seed or fertilizer spreaders that use a whirling disk. Premeasured amounts of granular larvicide can also be applied by hand (wearing appropriate PPE; PPE requirements can be found on the label) or with a motorized backpack, which costs between $600 and $800. Horn seeders have not proven to be as effective. Generally, recommended application rates range from 2 to 10 pounds per acre (check the label). The actual rate required at each site largely depends on the same factors discussed for liquid formulations. Often, treatment should be repeated every 7 days. Bti can also be formulated into briquets that are sold under the brand name Bactimos® (or something similar) or as “mosquito dunks.” They are usually more expensive than liquid and granular formulations. Cost per acre is about $20–$50. However, these floating briquets will give up to 30 days of treatment under normal conditions. Briquets can be used in many habitats where mosquitoes breed. They can be anchored to tree limbs or weights to keep them from floating away. Usually, one briquet will treat about 100 square feet of water surface, regardless of depth. Up to four briquets per 100 square feet may be required in heavily polluted water. Briquets can be applied to areas that flood during rainy periods such as woodland pools. These briquets will float when the area is flooded, releasing Bti. Effectiveness of Bti is not reduced by dry periods. Insect Growth Regulators Insect growth regulators (IGR) are a group of chemicals that kill insects by interfering with their normal process of growth and development. Methoprene is the most widely used IGR that affects mosquitoes and is often sold under the brand name Altosid® (Figure 15). The material can be applied to any larval stage. However, results are not immediate. Larvae will not die; instead, they continue their growth process and pupate. Pupae that develop from exposed larvae will die and adults will not emerge. Methoprene is only effective when applied to the larval stage. Any pupae that are present in the water during application will not die and will successfully emerge as adults. Methoprene comes in liquid (5% and 20%), granular, 30-day briquet, and extended 150-day briquet formulations. Apply methoprene at the start of the mosquito season. It can be used in a wide variety of places, such as storm drains, fountains, cesspools, waste treatment and settling ponds, abandoned swimming pools, and other manmade sites. The EPA has even approved methoprene use in livestock watering troughs. Briquets can be tossed into the water. They will sink to the bottom and slowly release the IGR. Residual effects range from 7 to 10 days for liquid to 30 to 150 days, depending on the formulation. Briquets are designed to withstand wet and dry periods to extend the residual effect through periods of heavy rainfall, flooding, etc. Mosquito control personnel must maintain current knowledge about approvals and use of larvicides and are encouraged to attend annual training conferences offered in the state. Adulticiding (Spray Trucks) Only selected chemicals are approved for use in thermo-fogging or ultra-low-volume (ULV) units in Mississippi. For the most part, spraying with trucks is done with ULV machines, as thermo-fogging is older technology. ULV spray machines put out a very fine mist with small droplet sizes (Figure 16). Consult the Mississippi Department of Agriculture and Commerce, Bureau of Plant Industries (Starkville, MS; 662-325-3390) for a current list of approved chemicals, mixing rates, and application rates. Different formulations are used in thermo-fogging units than are used for ULVs. Be sure you purchase the correct formulation for your machines. Always read the chemical label before buying, mixing, loading, applying, and storing insecticides. A few of the adulticides available are restricted-use pesticides and must be purchased and applied under the direct supervision of a certified pesticide applicator. All applicators should review and carry the chemical labels and material safety data sheets (MSDS) with them while conducting control activities. Insecticide labels and MSDS contain important information concerning the application rate, personal protection measures, statements of practical treatments, environmental hazards, and storage and handling procedures. Always remember, the label is the law. For best results, adulticiding should be done after sunset (there are a few exceptions). Chemicals sprayed during the day may be carried upward by thermal currents. Also, mosquitoes generally are resting during the day in protective foliage out of the pesticide’s reach, while bees may be exposed as they gather nectar. It is important to kill mosquitoes, not bees. Spray trucks should be driven slowly; usually 10 miles per hour. Be sure to drive at the same speed the entire evening to ensure a uniform rate of application. Ultra-low-volume sprayers cost from $7,000 to $17,000 (Figure 17). One of the most widely used ULV sprayers has an electric starter, manual and variable capabilities, and a GPS tracking system. These machines cost between $12,000 and $15,000. Machines must be kept in proper working order and calibrated yearly. In ULV machines, calibrate both flow rate and droplet size; in thermo-foggers, calibrate the flow rate only. Often, the vendor who sells the spray machine will help with calibration and droplet testing once a year. Change the oil on ULV units after every 50 hours of use; grease bearings on the blower every 6–8 hours; check filters twice a year; and replace chemical tubing yearly. When using corrosive chemicals, flush machines after each use. Always route the pesticide lines outside of the truck cab. Larviciding versus Adulticiding Results of a survey conducted in the spring of 1985 indicated that 148 city and county mosquito control programs were in operation within Mississippi. All but five of these programs relied exclusively on adulticiding for mosquito control, which is not an effective strategy. More than 84 percent of these programs used only malathion. More recent surveys have indicated hardly any use of malathion, with more and more mosquito control personnel using various formulations of pyrethroids (permethrin mostly) for adult mosquito control. These products are sold under a variety of brand names. Routine mosquito spraying has been going on in Mississippi for a long time. During the mosquito season, fog trucks roll up and down the urban streets one or two times per week. Continuous exposure to pesticides does not kill all mosquitoes; those that can survive the pesticide treatment are resistant to the chemical. Surviving mosquitoes can reproduce and pass this resistant trait along to the next generation. Eventually, the pesticide is no longer effective. Adulticiding operations also continuously expose the public to pesticides. The effects of these chemicals could be particularly severe for those people who have asthma or other respiratory problems. Applicator personnel may be in danger of overexposure if proper safety precautions are not carefully practiced. Pesticide labels carry warnings about their toxicity to wildlife. However, pesticides are generally safe when used according to their label directions. Larvicide programs are targeted at controlling the mosquito larvae (immature mosquitoes) before they leave the water. This strategy can be the most effective, most economical, and safest way to control mosquitoes. Programs that concentrate only on adult mosquitoes are attempting to solve a problem that has gotten out of hand. After all, it is adult mosquitoes, not the larvae, that pass along diseases such as encephalitis to human victims. It is best for public health and the environment to avoid using chemical pesticides when possible. A larvicide program uses biological methods to control pests without jeopardizing non-pest and beneficial organisms. When fog trucks remain parked until they are really needed (as a back-up system during severe outbreaks), you reduce the chance of pesticide resistance buildup and lessen the amount of chemicals that the public is exposed to. Larviciding is also more economical than adulticiding. Purchasing a fogging machine and truck for an adulticiding program can cost as much as $50,000 (Figure 18). Small towns may spend from $10,000 to $15,000 per year for pesticide and oils. Operational and maintenance costs must also be figured into the estimate. Therefore, the expense of an adulticide program is beyond the reach of most small towns and communities. A larvicide program, on the other hand, can be conducted using one or two backpack sprayers (ranging from $80 each for a sprayer that sprays only liquid to about $800–1,000 each for backpacks that distribute liquid, granules, pellets, and dust) and a couple of gallons of Bti (about $70 per gallon), depending on the size of the town and the extent of the breeding areas. More extensive larviciding programs may need heavy equipment to apply a variety of products (Figure 19). Granular Bti generally costs about $4 per pound. Methoprene (Altosid®) is another excellent and cost-effective larvicide that comes in various formulations. The standard “briquette” or pellet of Altosid® costs about $4 each. Initial material costs may be higher than most Bti products, but they have an extended residual, making the cost per day comparable to other products. More recent labeling states that methoprene is target-specific and does not harm mammals, waterfowl, or predatory insects. Non-target studies have reported that methoprene has very little effect, if any, on 35 species of non-target organisms and can be applied to fish habitats. Another larvicide is a biodegradable (Agnique®) oil emulsion sprayed as a larvicide. It acts by suffocating mosquito larvae as they float at the surface to breathe. These surface oils are also safe to use in fish habitats and in the presence of biological predators. Empowering Mosquito Control Personnel Mayors, aldermen, and county supervisors should take an active role in mosquito control to ensure efficiency and limit liability. If a lawsuit alleges that a town’s fogging truck caused a respiratory problem among residents, the municipality may be liable if the chemical in question was not applied correctly with a properly calibrated machine. One way to avoid this is to send mosquito control personnel to workshops and seminars for certifications and training. One such workshop is the annual Mosquito and Vector Control Workshop conducted by the Mississippi State Department of Health and other agencies. This meeting is usually held in March of each year in or near Jackson. In addition, mosquito control workers should read this publication and others available through the MSU Extension Service concerning safe and effective mosquito control. Mosquito Control and the Public Providing public information and soliciting public support is vital to the success of any mosquito control effort. Citizens should understand the effects they have on local mosquito populations. Inform the public about problems caused by artificial containers around their homes. Encourage residents to clean up their neighborhoods and rid their yards of breeding sites. Promote town cleanup drives, and sponsor mosquito seminars for schools and local organizations. Provide information on larviciding activities, and remind people of the potential public health threat mosquitoes represent. Invite citizens to call in complaints concerning severe mosquito problems. Mosquito control is a public effort. Without the help and support of citizens, mosquito control personnel will be fighting a losing battle. This work is partially supported by Crop Protection and Pest Management, Extension Implementation Program grant no. 2017-70006-27200/project accession no. 1014037 from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. The information given here is for educational purposes only. References to commercial products, trade names, or suppliers are made with the understanding that no endorsement is implied and that no discrimination against other products or suppliers is intended. Publication 3500 (12-23) By Jerome Goddard, PhD, Extension Professor, and Sarah J. McInnis, Graduate Student, Biochemistry, Molecular Biology, Entomology, and Plant Pathology. The Mississippi State University Extension Service is working to ensure all web content is accessible to all users. If you need assistance accessing any of our content, please email the webteam or call 662-325-2262.
Rationale-The yellowfin tuna (Thunnus albacares) is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide. The yellowfin tuna is among one of the the larger tuna species, reaching weights up to around180 kg (400 lb) which is massive, but is significantly smaller than the Atlantic and Pacific bluefin tunas, which can reach around450 kg in weight and slightly smaller than the bigeye tuna and the southern bluefin tuna. The yellow fin tuna grows up to 2.1 metres in length and lives up to the ages of seven. They live up to 250 metres in depth of the ocean which are capable of them eating squid and other pelagic crustaceans. They are able of diving to considerable depths of like up to 200 metres down. An individual tuna in the oceans spends most its time swimming and hunting in depths of 75m to the surface. Their body shape is made for speed chasing after other predators to eat like flying fish and even makeral. Yellowfin grow quick with a life span of only six to seven years of living which is a short life. They begin to reproduce little baby tunas when they reach the age of approximately two. The species is very productive, spawning throughout the year and Females can spawn almost daily, releasing millions of eggs each time and about 8 million in total. Their most productive spawning periods are in the spring and fall. Females release their eggs near the surface of the ocean where they are able to be fertilized and be ready to spawn and not eaten. Baby yellowfin stay close to the surface of the water away from predators, but move into deeper water as they mature and grow bigger so they can start to hunt . They are also known to meet up around areas like anchored buoys, whales and other large marine mammals. They are at the top of the food chain biggest predator of sea in the fish category and feed on other fish, squid and crustaceans. Climate change, pollution, and overfishing are all taking a heavy place on our fisheries and our planet. Climate change is affecting the ocean on many levels. These changes influence everything from droughts and floods to marine life and ocean currents creating the habitats to get destroyed. Pollution has destroyed entire aquatic habitats and left us with giant patches of floating debris all over our oceans which sea creatures eat or just get sick from it and die. Overfishing leaves us with destroyed ecosystems, nutrient-lacking species like unhealthy fish, and a lack of biodiversity in our very sophisticated food web. By catch is either catching to many fish or baby species and trawling and longlining is what mainly causes this as long lines just hook and kill babies and trawling they don’t even throw the babies back. Evidence-In 2014-2015 there was 2200 tones of yellow fin tuna caught which is sustainable. Tuna is used for humans to eat not for bait to catch other fish etc. Catching up to 5000 tones is bad as it is overfished. The yellowfin tuna lives up to 7 years of age and grow up to around 2 metres in length but are commonly caught at around 90cm and mostly weigh at around 100 kg and on the other hand full grown tuna weigh up to about 200 kg. the tuna can reproduce up to 8 mill eggs a day which means there are lots of them swimming around causing them to be sustainable. Yellow fin tuna are classified as near threatened and a threat to them is that people ae doing lots overfishing the little fish such as pilchards causing the yellow fin tuna not be able to eat them causing them not to be able to grow big. There found throughout the Pacific Indian and Atlantic oceans where they form big schools with other tuna such as skipjack and big eyes to create them to become less hunted. Conclusions- The yellow fin tuna is sustainable as they are caught frequently but reproduce really quick like they reproduce as the age of 2 and produce up to 8 million eggs which is pretty impressive and that also means there is an increase in the yellow fin tuna. It is good as the fishermen catch some and then they reproduce quickly which means that there is more tuna to be caught and more for us to eat. Yellow fin tuna are also warm bodied animals. Yellowfin Tuna are one of the most popular of the Tuna family, very important to commercial fisheries worldwide. They are marine dwelling, migratory fish found mainly in tropical and warm temperate waters. They are caught in waters Australia-wide by drifting long-lines. They are usually caught at 50-80kg and 1m in length. Evaluation-Yes, I believe I is true as I support my claim as it actually should continue in the future as tuna fishing is a fun thing to do and there also a good eating product. My opinion of the overall state of the yellow fin tuna is that it is a good fish as they reproduce quickly at the age of two and up to 8 million and some can even do 10 million eggs a day/season. The thing to be done in the future to keep these tuna sustainable is to make it that you can only take a few otherwise known as bag limits and that they are only aloud to fish for these yellow fin tunas at certain times such as non breeding season so they can breed and not take home babies so then they can grow up big and strong and be able to reproduce.
Summary: Information flow between the ventromedial premotor cortex and medial prefrontal cortex makes it possible for monkeys to correctly identify social cues. In baseball, a batter’s reaction when he swings and misses can differ depending on whether they were totally fooled by the pitch or simply missed the change-up they expected. Interpreting these reactions is critical when a pitcher is deciding what the next pitch should be. This type of socially interactive decision-making is the topic of a recent brain study led by Masaki Isoda at the National Institute for Physiological Sciences (NIPS) in Japan. They found that this ability requires a specific connection between two regions in the front of the brain, and that without it, monkeys default to making decisions as if they were playing against an inanimate object. Two regions in the front of the brain–the PMv and the mPFC–contain “self”, “partner”, and “mirror” neurons that signal self-actions, other-actions, or both, respectively. Scientists believe that these types of neurons are what make social qualities such as empathy possible. However, despite years of research, not much is known about how these brain regions work together. The NIPS team set out to find some answers. They trained monkeys to play a game with a partner in which they pressed buttons to obtain rewards. Sometimes, the rules of the game changed, and the monkeys made mistakes. Sometimes monkeys made mistakes simply because they were careless. “Monkeys continued using the same rule if they thought the other monkey’s mistakes were accidental,” says Masaki Isoda. “But, if they thought the mistakes were because the rules had changed, the monkeys adjusted their thinking and switched rules.” The researchers included three types of partners: real monkeys, recorded monkeys, and inanimate objects. They found that the proportion of partner cells was much higher in the mPFC than in the PMv, indicating it could be particularly important for understanding what others are thinking. Partner cells in the mPFC were most active and most affected by the PMv when partners were real and least active and least affected when they were inanimate objects. Thus, it seemed possible that the ability of a monkey to recognize social cues depends on mPFC cells getting social information from the PMv. To test this hypothesis, the researchers used viral vector technology to temporally silence only neurons in the PMv that connect to the mPFC. In this situation, monkeys made many more mistakes after their partners made careless errors, behaving as if every error was because the rules had changed. “This behavior was reminiscent of an autistic monkey who played the same game,” says Taihei Ninomiya. “As difficulty understanding social cues is a hallmark of autism, understanding the role of the PMv-mPFC pathway provides a good direction for future research into autism spectrum disorders.” About this neuroscience research news Source:NIPS Contact: Masaki Isoda – NIPS Image: The image is credited to Taihei Ninomiya A causal role for frontal cortico-cortical coordination in social action monitoring Decision-making via monitoring others’ actions is a cornerstone of interpersonal exchanges. Although the ventral premotor cortex (PMv) and the medial prefrontal cortex (MPFC) are cortical nodes in social brain networks, the two areas are rarely concurrently active in neuroimaging, inviting the hypothesis that they are functionally independent. Here we show in macaques that the ability of the MPFC to monitor others’ actions depends on input from the PMv. We found that delta-band coherence between the two areas emerged during action execution and action observation. Information flow especially in the delta band increased from the PMv to the MPFC as the biological nature of observed actions increased. Furthermore, selective blockade of the PMv-to-MPFC pathway using a double viral vector infection technique impaired the processing of observed, but not executed, actions. These findings demonstrate that coordinated activity in the PMv-to-MPFC pathway has a causal role in social action monitoring.
A sunfleck is basically a bright spot or dapple of light. The term is frequently used in an ecological context to describe bright spots of light reaching the forest floor. They result from the random movement of tree leaves tossed about in a breeze on a sunny day. This has huge consequences for the plants living in the understory. Plants often acclimate to local light conditions by producing leaves adapted to full sun (curiously enough, called sun leaves) or to full shade (shade leaves). Imagine being a small plant growing quietly in the shadow of large trees. Suddenly a sunfleck arrives, bathing your shade leaves in brilliant light. What a jolt. Leaf temperature suddenly climbs, water rapidly evaporates from your leaf surfaces and photosynthesis rate goes way up. Then just as quickly, the light disappears. Back to normal, only to have the light return a few seconds later. No such thing as getting used to your environment, because it’s always changing. The transient changes in biochemistry produced by sunflecks are fascinating and are the subject of ongoing scientific study. For example click here.
In Python, sequence is the generic term for an ordered set. There are several types of sequences in Python, the following three are the most important. Lists are the most versatile sequence type. The elements of a list can be any object, and lists are mutable - they can be changed. Elements can be reassigned or removed, and new elements can be inserted. Tuples are like lists, but they are immutable - they can't be changed. - + combines two sequences in a process called concatenation. For example, [1,2,3]+[4,5] will evaluate to [1,2,3,4,5]. - * repeats a sequence a (positive integral) number of times. For example, [1,11]*3 will evaluate to [1,11,1,11,1,11]. - x in mySeq will return True if x is an element of mySeq, and False otherwise. You can negate this statement with either not (x in mySeq) or x not in mySeq. - mySeq[i] will return the i'th character of mySeq. Sequences in Python are zero-indexed, so the first element has index 0, the second has index 1, and so on. - mySeq[-i] will return the i'th element from the end of mySeq, so mySeq[-1] is the last element of mySeq, mySeq[-2] is the second-to-last element, etc. - All sequences can be sliced. - len(mySeq), short for length, returns the number of elements in the sequence mySeq. - mySeq.index(x) returns the index of the first occurrence of x in mySeq. Note that if x isn't in mySeq index will return an error. (Use in with an if statement first to avoid this.) - min(mySeq) and max(mySeq) return the smallest and largest elements of mySeq, respectively. If the elements are strings this would be the first and last elements in lexicographic order (the order of words in a dictionary). Note that if any two elements in mySeq are incomparable (a string and a number, for example), min and max will return errors. - mySeq.count(x) returns the number of occurrences of x in mySeq (that is, the number of elements in mySeq that are equal to x).
Curious about what solar panel systems are? Sunshine is available to using abundance, and solar systems use efficient technology to harvest and turn this energy into electricity with pre-defined methods. Solar power panels serve the purpose of collecting solar energy and converting it through the photovoltaic (PV) effect into electric power. Many homes have a roof or backyard, which can be used for installing solar systems to generate electricity. A home solar system must provide ample electrical energy to meet all home power needs. It provides AC power, as typically all households use AC power to operate lighting systems, electronics, appliances and machinery such as machines, refrigerators, mixers, fans, air conditioners, TVs and music systems.vThe price of the home solar power plant varies on its size and type. On-grid and off-grid solar systems come in two types of solar power plants. Let’s look at the difference between the two: 1. Off-Grid Solar System An off-grid solar system is well designed to generate enough power throughout the year to meet the needs of a household, even in the depths of winter, when there is less sunshine. However, since there is no electricity grid connection to an off-grid solar system, battery storage is necessary. The high cost of batteries and inverters implies that the off-grid solar system is costly than the alternatives, so they are usually needed only in more remote areas far from the grid. Nevertheless, battery costs are reducing at a high rate, so the demand for an off-grid solar system is now increasing, even in cities and towns. Advantages of An Off-Grid Solar System - Such an off-grid solar system can function independently and not rely on the grid. - They generate enough electricity that can be collected and used at night. - These are suitable for remote areas that do not have grid power access. - Shutdowns and infrastructure faults won’t affect the power supply. 2. On-Grid Solar System On-grid solar systems are the most widely solar product used by homeowners. Such systems do not need batteries and are connected to the public electricity grid and use solar inverters. Any surplus solar power you produce is sold to the electricity grid, and the energy you sell is usually paid a feed-in tariff (FiT) or credits. Solar inverters are an essential part of a residential solar energy system, convert the electricity your solar panels create into a form that can be used by the appliances, lighting, and other electronics. Learn more about solar inverters here. Unlike an off-grid solar system, because of safety reasons, these are unable to work or generate electricity during a blackout. Because blackouts usually occur when the electricity grid is disabled, if the solar inverter had fed energy into a broken grid, it would endanger the safety of the people fixing the network’s faults. Most on-grid solar systems with battery storage can separate itself from the grid (known as islanding) and continue to supply some power during a blackout. Advantages of An On-Grid Solar System - On-grid solar systems are incredibly cost-effective and easy to install. - By balancing electricity bills in just 3-8 years, you can recoup the cost of your expenditures. - Residential users can earn a passive income for the surplus energy generated by the system. Choose Between On-Grid Vs Off-Grid Solar Systems to Fit Your Needs Solar power systems are a form of clean, renewable energy, and they have many benefits depending on the type of system you chose. Knowing the advantages of both an on-grid and off-grid solar system, you can select the one according to your needs. With the right solar system and proper installation, you can have clean and cost-effective energy, without being worried about maintenance problems.
Invertebrate is a kind of animal that does not have a spinal column or backbone. It is the opposite of vertebrate, that means if an animal is not a vertebrate (fish, reptile, amphibian, bird, or mammal), it is an invertebrate. The main phyla (groups) of invertebrate animals are: - Annelida: segmented worms - Arthropods: (arachnids, crustaceans, insects, and others); - Brachiopods: the lamp-shells. - Bryozoa: sea mats or moss animals (sometimes they look like corals) - Cnidarians: jellyfish, sea anemones, hydroids. - Echinoderms: starfish, sea urchins, sea cucumbers - Molluscs: (gastropods, cephalopods, bivalves and others); - Nematoda: roundworms - Porifera: sponges - Platyhelminthes: flatworms - Rotifers: tiny "wheel animals", which live in habitats such as pond water. There are 18 more groups of invertebrates, mostly minor: see List of animal phyla.
Free equation worksheets for algebra learners help to practice with equations involving one step, two steps and multisteps. One step,Two step, and Systems of equations worksheets are provided in distinct web pages. Multistep equations worksheets are listed here. Also find pages related to equation at the bottom of this page. Solving equations worksheets in two steps involve two math operators addition/subtraction with multiplication/division. Multi-Step Equations Worksheets Next level after one step and two step is multistep equation worksheets. Here you can find multi step equation worksheets with different number coefficients such as integers, fractions and decimals. This is good practice for algebra learners and for those who seeks advanced level of solving equations.
An algorithm (pronounced AL-go-rith-um) is a procedure or formula for solving a problem, based on conducting a sequence of specified actions. A computer program can be viewed as an elaborate algorithm. In mathematics and computer science, an algorithm usually means a small procedure that solves a recurrent problem. An encryption algorithm transforms data according to specified actions to protect it. A secret key algorithm such as the U.S. Department of Defense’s Data Encryption Standard (DES), for example, uses the same key to encrypt and decrypt data. As long as the algorithm is sufficiently sophisticated, no one lacking the key can decrypt the data. The word algorithm derives from the name of the mathematician, Mohammed ibn-Musa al-Khwarizmi, who was part of the royal court in Baghdad and who lived from about 780 to 850. Al-Khwarizmi’s work is the likely source for the word algebra as well. In mathematics, the Euclidean algorithm, or Euclid’s algorithm, is an efficient method for computing the greatest common divisor(GCD) of two numbers, the largest number that divides both of them without leaving a remainder. It is named after the ancient Greek mathematician Euclid, who first described it in Euclid’s Elements (c. 300 BC). It is an example of an algorithm, a step-by-step procedure for performing a calculation according to well-defined rules, and is one of the oldest algorithms in common use. It can be used to reduce fractions to their simplest form, and is a part of many other number-theoretic and cryptographic calculations. The Euclidean algorithm is based on the principle that the greatest common divisor of two numbers does not change if the larger number is replaced by its difference with the smaller number. For example, 21 is the GCD of 252 and 105 (as 252 = 21 × 12 and 105 = 21 × 5), and the same number 21 is also the GCD of 105 and 252 − 105 = 147. Since this replacement reduces the larger of the two numbers, repeating this process gives successively smaller pairs of numbers until the two numbers become equal. When that occurs, they are the GCD of the original two numbers. By reversing the steps, the GCD can be expressed as a sum of the two original numbers each multiplied by a positive or negative integer, e.g., 21 = 5 × 105 + (−2) × 252. The fact that the GCD can always be expressed in this way is known as Bézout’s identity. EXAMPLE OF AN ALGORITHM: 1599 = 650×2 + 299 650 = 299×2 + 52 299 = 52×5 + 39 52 = 39×1 + 13 39 = 13×3 + 0
Dante's poem relating his heavenly ordained journey through Hell, Purgatory and Paradise enjoyed immediate success: more than 600 surviving manuscripts of the Divine Comedy produced during the 14th century attest to the work's popularity. Consequently, Dante's vernacular classic was among the first books to be printed when the new technology of moveable type was introduced into Italy from Germany during the 1460s and 1470s. Publishers and printers repeatedly turned to Dante for his proven marketability throughout the Renaissance. The editorial history of Dante's poem thus presents in concentrated form a history of the early modern book trade: that is, of the ways in which editions of the literary classics were prepared, produced, marketed and sold between the late 15th and early 17th centuries. This exhibition presents a panoramic perspective on the material history of the early modern printed book including a wide variety of book sizes, page designs, typography and iconographical programs. The Renaissance editorial history of the Divine Comedy vividly illustrates how the literary classic became an object of commercial exchange, subject to market forces in the age of print. The editorial history of the Divine Comedy also reflects the critical reception of the poem during the Renaissance. The traditional competition between "Dante the theologian" and "Dante the poet" finds expression in the ongoing editorial rivalry between oversized editions overflowing with scholarly commentary and elegant portable volumes without commentary designed to appeal to both courtly and bourgeois readers of Dante, the vernacular poet. Most importantly, however, Dante's poem plays a central role in the Renaissance creation of a national Italian linguistic and literary identity. The establishment of an authoritative text of the Divine Comedy, and generally speaking, questions surrounding Dante's language, were the focus of a controversy between Florence and other Italian centers about the appropriate linguistic and rhetorical model for Italian literature. The process by which the Florentine Dante's poem came to be canonized as an "Italian" classic roughly parallels the process by which the Florentine vernacular came to be adopted as the literary language throughout the peninsula, thus reducing the regional languages of Italy to dialect Finally however, the history of the critical reception of Dante's poem during the Renaissance is also a story about the poem's decline in popularity. The prophetic claims and religious fervor of the Divine Comedy, no less than the poem's unorthodox language and style, were incompatible with the neo-classicism of Renaissance literary culture, which preferred the lyric poetry of Petrarch. Dante in fact assumes a marginalized (albeit classic) status with respect to Petrarch in the Italian tradition at this time. As the Renaissance advanced and matured into Mannerism and the Baroque, the distance between "modern" cultural and literary sensibilities and the "medieval" poet grew larger. Significantly, only three editions of the Divine Comedy appeared during the 17th century. Indeed, Dante will not return to the fore until the 19th and 20th centuries, and only then will the Divine Comedy finally achieve its now familiar status as a classic of world literature.
Coral reef ecosystems are among the most diverse and highly productive ecosystems on the planet yet are currently threatened by a number of natural and human-induced factors. Regardless of the cause, reef degradation generally results in an irreversible phase-shift from dominance by reef-building corals to dominance by fleshy macroalgae or seaweed. These shifts are believed to be irreversible and lead to communities that are less diverse and much less complex. While a number of natural disturbances can cause localized coral mortality, reduced top-down control (caused by overfishing) and increased bottom-up control (caused by nutrient pollution) are the most frequently implicated causes of human-induced reef degradation (aside from global warming). The relative importance of each of these factors in causing reef decline has been the subject of debate and much research among scientists. However, despite much effort there is still not consensus in the scientific community as to how these factors independently and interactively influence phase-shift formation or the loss of reef building coral. Further, not all phase-shifts are alike; some result in blooms of a single species of algae while others result in a more diverse mixed species assemblage and still others involve exotic species. Through analysis and synthesis of data from the literature, this project will develop conceptual models to determine the relative strength of top-down versus bottom-up control on coral reefs. Ultimately these results will help to identify the importance of overfishing and nutrient pollution on reefs by specifically identifying how these factors influence benthic reef community structure. The information generated by this project will be highly useful in implementing sound science-based management decisions for conservation of coral reef ecosystems across the globe. One of the most intriguing questions in coral reef ecology has been to understand how and why corals dominate the landscape (Figure 1) while plants dominate most other ecosystems on the planet. Reef ecologists generally believe that a combination of physical and biological factors favor the dominance of corals over algae on healthy or pristine reefs. Humans, however, can have dramatic effects on coral reef communities by altering any of the above factors, often shifting the competitive edge away from the corals and in favor of faster growing fleshy algae (Figure 2). From a biological perspective, dense populations of grazing fish and sea urchins on healthy reefs help keep algae cropped to low levels (Figure 3). Generally on reefs with abundant fish and invertebrate populations, the algae that are present are either very small turfs that have fast growth rates or are either chemically and/or physically defended against grazers. Experimental evidence suggests that the removal of grazers from reefs through overfishing or disease can allow algae to begin overgrowing corals and eventually cause a phase shift where long-lived, slow-growing corals are replaced by fleshy, fast-growing seaweeds (Figure 2). From a physical perspective, the availability of nutrients, primarily nitrogen and phosphorus, can also influence the growth rates and abundance of algae on reefs. Most reefs have developed in the clear, warm and nutrient deficient waters of the tropics. The coral organisms and their symbiotic zooxanthellae (microscopic single celled algae that live inside the coral tissue) are extremely efficient at using nutrients and are able to survive with very little external input. Reef algae and seagrasses, on the other hand, need external sources of nitrogen and phosphorus to survive. These organisms are able to absorb nutrients from the water column, sand or sediment. On healthy reefs the low input of nutrients prevents algae from being "fertilized". In extreme cases where nutrient inputs are high (from sewage outfalls, terrestrial runoff containing agricultural fertilizers, landscaping, etc.), algae may be able to overgrow corals and become dominant, even occasionally forming large blooms (Figure 4). The introduction of exotic, alien or non-native species has caused numerous problems around the globe able to out-compete native species. In places such as the Hawaiian Islands, this is particularly a problem because there are so many endemic species (species which are only found in Hawai'i). Over the years several species of marine algae have been introduced to Hawaiian reefs, primarily for experimental aquaculture. Unfortunately many of these species have spread from their initial points of introduction and have become quite abundant on the shallow reef flat environments around the Hawaiian Islands. These invasive species are seen as one of the largest threats to global biodiversity, as they are often (Figure 5). While invasive species are known to have negative effects on ecosystem structure and function in forests, grasslands, lakes and some cold water marine environments much less is known about invaders on coral reefs.
The Sino-Pakistan Agreement (also known as the Sino-Pakistan Frontier Agreement and Sino-Pak Boundary Agreement) is a 1963 document between the governments of Pakistan and China establishing the border between those countries. It resulted in China ceding over 1,942 square kilometres (750 sq mi) to Pakistan and Pakistan recognizing Chinese sovereignty over hundreds of square kilometers of land in Northern Kashmir and Ladakh. The agreement is controversial, not recognized as legal by India, which also claims sovereignty over part of the land. In addition to increasing tensions with India, the agreement shifted the balance of the Cold War by bringing Pakistan and China closer together while loosening ties between Pakistan and the United States. Issue and result In 1959 Pakistan became concerned that Chinese maps showed areas of Pakistan in China. In 1961 Ayub Khan sent a formal Note to China, there was no reply. It is thought that the Chinese may not have been motivated to negotiate with Pakistan because of Pakistan's relations with India, with which China was soon to enter a war with. After Pakistan voted to grant China a seat in the United Nations, the Chinese withdrew the disputed maps in January 1962, agreeing to enter border talks in March. The willingness of the Chinese to enter the agreement was welcomed by the people of Pakistan. Negotiations between the nations officially began on October 13, 1962 and resulted in an agreement being signed on 2 March 1963. It was signed by foreign ministers Chen Yi for the Chinese and Zulfikar Ali Bhutto for the Pakistani. The agreement resulted in China withdrawing from about 750 sq m of territory, and Pakistan withdrawing its claim to about 2,050 sq m of territory (which it had not in fact occupied or administered). The text of the agreement was as follows: - The Government of the People’s Republic of China and the Government of Pakistan; HAVING agreed, with a view to ensuring the prevailing peace and tranquility on their respective border, to formally delimit and demarcate the boundary between China’s Sinkiang and the contiguous areas the defence of which is under the actual control of Pakistan, in a spirit of fairness, reasonableness, mutual understanding and mutual accommodation, and on the basis of the ten principles as enunciated in the Bandung conference. Being convinced that this would not only give full expression to the desire of the people of China and Pakistan for the development of good neighbourly and friendly relations, but also help safeguard Asian and world peace. - Have resolved for this purpose to conclude the present agreement and have appointed as their respective plenipotentiaries the following. - For the Government of the People's Republic of China; Chen Yi, Minister of Foreign Affairs. - For the Government of Pakistan Zulfikar Ali Bhutto, Minister of External Affairs. - Who, having mutually examined their full powers and found them to be in good and due form have agreed upon following: - Article 1 - In view of the fact that the boundary between China’s Sinkiang and the contiguous areas the defence of which is under the actual control of Pakistan has never been formally delimited, two parties agree to delimit it on the basis of the traditional customary boundary line including features and in a spirit of equality, mutual benefit and friendly cooperation. - Article 2 - In accordance with the principle expounded in Article 1 of the present agreement, the two parties have fixed as follows the alignment of the entire boundary line between China’s Sinkiang and the contiguous areas the defence of which is under the actual control of Pakistan. - 1 Commencing from its north western extremity at height 5,630 metres (a peak the reference coordinates of which are approximately longitude 74 degrees 34 minutes east and latitude 37 degrees 3 minutes north), the boundary line runs generally eastward and then South-eastward strictly along the main watershed between the tributaries of the Tashkurgan River of the Tarim river system on the one hand on the tributes of the Hunza river of the Indus river system on the other hand, passing through the Kilik Daban (Dawan), the Mintake Daban (pass), the Kharchanai Daban (named on the Chinese map only), the Mutsgila Daban (named on the Chinese map only) and the Parpik Pass (named on the Pakistan map only) and reaches the Khunjerab (Yutr) Daban (Pass). - 2 After passing through the Khunjerab (Yutr) Daban (pass) the boundary line runs generally southward along the above-mentioned main watershed up to a mountain-top south of the Daban (pass), where it leaves the main watershed to follow the crest of a spur lying generally in a south-easterly direction, which is the watershed between the Akjilga river ( a nameless corresponding river on the Pakistan map) on the one hand, and the Taghumbash (Oprang) river and the Koliman Su (Oprang Jilga) on the other hand. According to the map of the Chinese side, the boundary line, after leaving the south-eastern extremity of the spur, runs along a small section of the middle line of the bed of the Koliman Su to reach its confluence with the Kelechin river. According to the map of the Pakistan side, the boundary line, after leaving the south-eastern extremity of this spur, reaches the sharp bend of the Shaksgam or Muztagh river. - 3 From the aforesaid point, the boundary lines runs up the Kelechin river (Shaksgam or Muztagh river) along the middle line of its bed its confluence (reference coordinates approximately longitude 76 degrees 2 minutes east and latitude 36 degrees 26 minutes north) with the Shorbulak Daria (Shimshal river or Braldu river). - 4 From the confluence of the aforesaid two rivers, the boundary line, according to the map of the Chinese side, ascends the crest of a spur and runs along it to join the Karakoram range main watershed at a mountain-top (reference coordinates approximately longitude 75 degrees 54 minutes east and latitude 36 degrees 15 minutes north) which on this map is shown as belonging to the Shorgulak mountain. According to the map of the Pakistan side, the boundary line from the confluence of the above mentioned two river ascends the crest of a corresponding spur and runs along it, passing through height 6.520 meters (21,390 feet) until it joins the Karakoram range main watershed at a peak (reference coordinates approximately longitude 75 degrees 57 minutes east and latitude 36 degrees 3 minutes north). - 5 Thence, the boundary line, running generally south-ward and then eastward strictly follows the Karakoram range main watershed which separates the Tarim river drainage system from the Indus river drainage system, passing through the east Mustagh Pass (Muztagh pass), the top of the Chogri peak (K2) the top of the Broad Peak, the top of the Gasherbrum mountain (8,068), the Indirakoli pass (names of the Chinese maps only) and the top of the Teram Kangri peak, and reaches its south-eastern extremity at the Karakoram Pass. Then alignment of the entire boundary line as described in section one of this article, has been drawn on the one million scale map of the Pakistan side in English which are signed and attached to the present agreement. In view of the fact that the maps of the two sides are not fully identical in their representation of topographical features the two parties have agreed that the actual features on the ground shall prevail, so far as the location and alignment of the boundary described in section one is concerned, and that they will be determined as far as possible by bgint survey on the ground. - Article 3 - The two parties have agreed that: - i) Wherever the boundary follows a river, the middle line of the river bed shall be the boundary line; and that - ii) Wherever the boundary passes through a deban (pass) the water-parting line thereof shall be the boundary line. - Article 4 - One the two parties have agreed to set up, as soon as possible, a joint boundary demarcation commission. Each side will appoint a chairman(Chaudry Mohammad Aslam for the Pakistani side), one or more members and a certain number of advisers and technical staff. The joint boundary demarcation commission is charged with the responsibility in accordance with the provisions of the present agreement, to hold concrete discussions on and carry out the following tasks jointly. - 1) To conduct necessary surveys of the boundary area on the ground, as stated in Article 2 of the present agreement so as to set up boundary markers at places considered to be appropriate by the two parties and to delineate the boundary line of the jointly prepared accurate maps. - To draft a protocol setting forth in detail the alignment of the entire boundary line and the location of all the boundary markers and prepare and get printed detailed maps, to be attached to the protocol, with the boundary line and the location of the boundary markers shown on them. - 2) The aforesaid protocol, upon being signed by representatives of the governments of the two countries, shall become an annex to the present agreement, and the detailed maps shall replace the maps attached to the present agreement. - 3) Upon the conclusion of the above-mentioned protocol, the tasks of the joint boundary demarcation commission shall be terminated. - Article 5 - The two parties have agreed that any dispute concerning the boundary which may arise after the delimitation of boundary line actually existing between the two countries shall be settled peacefully by the two parties through friendly consultations. - Article 6 - The two parties have agreed that after the settlement of the Kashmir dispute between Pakistan and India, the sovereign authority concerned will reopen negotiations with the Government of the People's Republic of China on the boundary as described in Article. Two of the present agreement, so as to sign a formal boundary treaty to replace the present agreement, provided that in the event of the sovereign authority being Pakistan, the provisions of the present agreement and of the aforesaid protocol shall be maintained in the formal boundary treaty to be signed between the People’s Republic of China and the Islamic Republic of Pakistan. - Article 7 - The present agreement shall come into force on the data of its signature. - Done in duplicate in Peking on the second day of March 1963, in the Chinese and English languages, both side being equally authentic. The agreement was moderately economically advantageous to Pakistan, which received grazing lands in the deal, but of far more significance politically, as it both diminished potential for conflict between China and Pakistan and, Syed indicates, "placed China formally and firmly on record as maintaining that Kashmir did not, as yet, belong to India. India does not recognize the agreement, under which China holds 5,180 square kilometres (2,000 sq mi) of northern Kashmir, as legal. Time, reporting on the matter in 1963, expressed the opinion that by signing the agreement Pakistan had further "dimmed hopes of settlement" of the Kashmir conflict between Pakistan and India. According to Jane's International Defence Review, the agreement was also of significance in the Cold War, as Pakistan had ties with the United States and membership in the Central Treaty Organization and the Southeast Asian Treaty Organization. The agreement was part of an overall tightening of association with China for Pakistan, which resulted in Pakistan's distancing from the United States. After defining borders, the two countries also entered into agreements with respect to trade and air-travel, the latter of which was the first such international agreement China had entered with a country that was not Communist. - The Geographer. Office of the Geographer. Bureau of Intelligence and Research. Department of State, United States of America (November 15, 1968), China – Pakistan Boundary (PDF), International Boundary Study 85, Florida State University College of Law - Syed, 88. - Syed, 89. - Press Trust of India (2006-12-04). "China illegally occupying land". expressindia.com. Retrieved 2009-03-13. - "Factbox: India and China border dispute festers". Reuters. 2006-11-15. Retrieved 2009-03-13. - "Signing with the Red Chinese". Time. 1963-03-15. Retrieved 2009-03-13. - "Strategic and security issues: Pakistan-China defense co-operation an enduring relationship". Janes' International Defence Review. 1993-02-01. Retrieved 2009-03-13.[dead link] - Dixit, Jyotindra Nath (2002). India-Pakistan in War & Peace. Routledge. p. 141. ISBN 0-415-30472-5. - Mitra, Subrata Kumar; Mike Enskat; Clemens Spiess (2004). Political parties in South Asia. Greenwood Publishing Group. p. 157. ISBN 0-275-96832-4. - Syed, 93-94.
Start by observing the living species around you. Choose two non-human species that interact with each other,such as bees and flowers,or predetor and prey species or two species that compete.Or, you can consider the effect of an enviromental factor on living non-human organisims,such as the effects of light or sound on plants or animals,or how food preference,or nutrient quanity/quality effect plants and animals.just a few examples.Your observations may lead you to many other types of questions about living organisims,their interactions and requirements for life. Start with an introduction and move through the steps of the scientific method, including observations/introduction, question, hypothesis, prediction, method/experiment, data collection, results (made up), and conclusion/discussion. I think it would be easier to base an experiment on an organism and an environmental factor, as opposed to the relationship between two organisms. I would suggest something such as the relationship between plants and the amount of water they receive. Start with an Introduction/Observation and move through the steps of the Scientific Method as outlined below. Your paper should follow this format. Remember, you don't have to actually do the experiment, just write what you would do to test your hypothesis. Introduction: Describe your observation. Include background information about your observation that you have found using references. For example, I observe that usually plants need water in order to grow. However, there are some plants in deserts that hardly get any water and they still live. (These are my observations, but you would want to find additional plant data to add to this section specific to the plant you choose for your own experiment.) Question: Ask a question about the observation that you have made. When developing a problem or question for a particular situation, you are simply stating the obvious. This is usually the easiest part of the scientific method. Examples might include: Is there such a thing as too much water for a plant? or Does more water result in taller plants? Hypothesis: Write a statement that ... This solution walks step by step through the scientific method and explains each step, and providing examples of each step.
IBEX's ribbon in the sky: scientists unravel the mystery NASA's Interstellar Boundary Explorer (IBEX) spacecraft recently detected a mysterious ribbon of particles at the edge of the solar system. Scientists now say it may have been formed by atoms reflected back into the solar system by the Milky Way's magnetic field. A ribbon in the sky? Who, besides Stevie Wonder, knew? Until last October, no one knew. Then NASA's Interstellar Boundary Explorer (IBEX) spacecraft revealed the unexpected feature as it mapped the frontier between the solar system and interstellar space. Now, a team of space physicists posits that the ribbon seen in the IBEX map of the sky is likely being formed by atoms that originally came from the sun as part of the solar wind. The Milky Way's magnetic field is in effect reflecting them back in a kind of cosmic bank shot. If the explanation holds up, IBEX's ribbon represents the first crude measurement of the local portion of the galaxy's magnetic field, says Jacob Heerikhuisen, a space physicist at the University of Alabama at Huntsville, who led the team. "That's the most exciting thing for us," he says. Researchers are trying to understand the boundary region between the solar system and interstellar space because that boundary shields the solar system from some 90 percent of the high-energy cosmic rays bombarding it, explains Nathan Schwadron, a space physicist at Boston University and member of the team reporting the results in the Jan. 10 issue of the Astrophysical Journal Letters. Interstellar space represents "a harsh radiation environment," he says. The ribbon's appearance on the IBEX map was a shock to mission scientists. They had anticipated that the map would reveal a fairly uniform distribution of fast-moving, or "energetic," neutral atoms across the sky. These atoms form when electrically charged particles – largely protons – speed away from the sun at anywhere between 600,000 to 1.8 million miles an hour. As this "solar wind" travels, some of these protons meet up with neutral atoms wandering into the solar system from interstellar space. Solar-wind particles can steal electrons from these incoming neutrals. This converts the outbound solar-wind particles into outbound neutral atoms. Because they are electrically neutral, they are oblivious to the sun's magnetic field and continue to hurtle beyond its influence into interstellar space. IBEX revealed a fairly uniform distribution of these energetic neutral atoms across most of the sky, although they appeared in amounts two to three times higher than expected. But it also detected a "ribbon" of these atoms, distinguished by having three times the density of the surrounding ones. A volley of ions Mr. Heerikhuisen's team opted to test via a modeling exercise one explanation for the ribbon – the bank shot. The group realized that for any explanation of the ribbon's formation to work, it had to account for the ribbon's orientation across the sky. It also had to explain why the range of energies the neutral atoms display is virtually the same whether the atoms are part of the ribbon or not. And it had to include physics that weren't in typical computer simulations of the interface between the solar system and the material found in interstellar space. As the team's model tells the story, when the outbound energetic neutral atoms leave the sun's sphere of influence – the so-called heliosphere – a fraction of them lose an electron and become ionized again. Now that they again carry an electrical charge, the ions respond to the galaxy's magnetic field. In a kind of cosmic backhand volley, the Milky Way's magnetic field sends some of these back at the solar system. Along the way, the ions can once again grab electrons, reform as neutral atoms, and continue to flit back through the heliosphere to be picked up by IBEX's detectors. One reality check on this model: What if IBEX records the ribbon changing position with time? Mr. Schwadron, one of Heerikhuisen's team, notes that their ribbon remains stable over long periods of time. But already, a second map unveiled at the American Geophysical Union's December meeting in San Francisco suggests that the ribbon has slightly changed position in the period between the maps. Since the model is averaging the ribbon's position over those periods, it could accommodate some minor short-term shifts in position, Schwadron says. "It will require lots of work to separate these out," he says. Follow us on Twitter.
Molly Bang crafts a tale about anger that kids of all ages can relate to. Click here to read When Sophie Gets Angry–Really, Really Angry… at the ICDL (International Children’s Digital Library), then answer the questions below. 1. When you watch a movie or read a book, you are the audience. When writers sit down to create a story, they think about their audience, or who will read the book when it’s finished. Molly Bang is the author of When Sophie Gets Angry–Really, Really Angry… Describe the audience. 2. Writers write for a reason. This reason is called the author’s purpose. There are three main purposes. The first is to entertain, which means to tell a story that is fun to read. The second reason is to inform. An author informs their audience when they teach them something new. The third reason is to persuade, which is when an author tries to get their audience to do something, or stop doing something. Describe Molly Bang’s purpose for writing this book. 3. Narratives are stories, and the characters are the animals, people, or other creatures in the story. Who are the characters in this narrative? 4. The setting of a narrative is where and when it takes place. What is the setting of When Sophie Gets Angry–Really, Really Angry…? 5. A narrative has a conflict, and a resolution. The conflict is the problem. The resolution is how the problem gets fixed. How would you describe the conflict of this narrative? 6. How does Sophie resolve the conflict? 7. Molly Bang received a Caldecott Award for her illustrations in this book. How does she use color to make the characters, setting and action come to life? 8. Writers use similes to compare two things with the words like or as. For example, an author could say a runner is as speedy as a cheetah. Metaphors compare two things without using like or as. When Sophie gets angry, Molly Bang uses the metaphor, “Sophie is a volcano, ready to explode.” Write another metaphor for anger that describes Sophie. Next, write a simile for Sophie. 9. Many authors use onomatopoeia to make their books fun to read. Onomatopoeia are words that sound like something real. Some examples are bonk, splat and whoosh. Find “PABAM!” in the book. Why does Molly Bang (whose last name happens to be an example of onomatopoeia) use onomatopoeia on this page? 10. Create a list of five other examples of onomatopoeia that could be used instead of “PABAM!” 11. Alliteration is when authors use the same beginning sound for words. For example, a light, little leaf landed on a log in Louisiana late last night. Locate an example of alliteration in the book. Write the example of alliteration, then draw a picture that matches the words. 12. Look closely at each page of the book. Find your favorite illustration. Use alliteration to describe what you see on the page. 13. The five senses are sight, touch, smell, taste and hearing. A person is mindful when they focus one or more senses on a single thought, feeling, flavor, texture, color or sound. Sophie is mindful after she cries. How does she use her senses during this part of the story? 14. How does mindfulness help Sophie feel better? 15. Describe a time you or someone you know were as angry as Sophie. Describe the conflict. Use transition words like first, next, then, before, after, etc. If there was a resolution, describe that too. 16. How could mindfulness have helped the person feel better? 17. When Sophie sits in the beech tree, Molly Bang writes, “The wide world comforts her.” Click here for a kids’ dictionary, then look up the meaning of comfort. How can the “wide world” comfort a person? 18. Describe a time something or someone comforted you. Use transition words like first, next, then, before, after, etc. 19. Think about a time when you comforted another person or animal. Describe what happened. Use transition words like first, next, then, before, after, etc. 20. When readers compare two things, they think about how they are the same. Compare yourself to Sophie. 21. Readers contrast two things when they think about how they are different. Contrast Sophie and yourself. 22. When Sophie gets home, it is “warm and smells good.” Warm and good are adjectives. Adjectives are used to describe something. Close your eyes and image the warm home, and why it smells good. Explain why the home smells good. Use other adjectives to describe what you imagine. 23. After reading When Sophie Gets Angry–Really, Really Angry…, what questions would you like to ask Sophie, her family, or the author? 24. Everyone feels angry, sad, or worried sometimes. These feelings are perfectly normal. It’s okay to feel these emotions, and it’s important to recognize them. Recognize means you know what something is, and that it is there. When we feel sad, worried, or angry about something, we can stop to be mindful of our feelings. When we hold on to one of these feelings for too long, it’s like trying to blow up a balloon more and more until it pops. When we feel like we’re going to pop like a balloon, we need to stop, recognize what is happening, then let out the air. Click here and explore a mindfulness exercise you can use anytime you feel like you’re about to pop like a balloon. E X T E N D . . . . 1. Imagine yourself coming home. Close your eyes and count to thirty. Be mindful of your surroundings. Write and complete the passage below to describe the experience. When I walk inside, my home smells __________. I also smell __________. I see __________, __________, and __________. They are __________. I can hear __________, __________, __________, and __________. I sit down, and the __________ feels __________, and __________. __________ brings me a __________ for a snack, and I can taste __________, and __________. My home is… 2. Create the scene of yourself coming home. Draw, paint or sculpt what you described. Give it to someone special.
Scientific Name: Corallus caninus The species name for these snakes, caninus, comes from the Emerald Tree Boa’s facial resemblance to dogs. When looked at from the side, the bulges on the back of the snake’s head, its angled snout, and its elongated teeth are similar to a dog’s head. These carnivorous reptiles locate their food primarily through sight and through heat-sensing pits located under their upper lip. They also use their tongue and organs within their nose to sense chemical cues and vibrations from approaching prey. Emerald Tree Boas eat their prey whole after first constricting their meal and then holding onto it with their long, curved and sharp teeth. STATUS: The population of Emerald Tree Boas is stable, but habitat loss is a concern. Raptors, as well as wild feline species and other carnivorous mammals prey upon them. HABITAT: These snakes range through the wet lowland rainforests of Peru, Venezuela, Bolivia, Guyana, Brazil, French Guiana, Colombia, and Suriname. They are an arboreal species living in the canopy and understory of rainforests that receive more than 59 inches of rain per year. They spend most of their lives in trees but may occasionally descend to the ground. DIET: Emerald Tree Boas consume rodents, lizards, monkeys, bats, and possibly birds. They have a slow metabolism and may go months without eating. PHYSICAL CHARACTERISTICS: Called “Emerald” because of the beautiful green markings on the backs of the adult boas, many also have white patterns bordered with black, gray, or dark green on these ventral surfaces. Their dorsal, or stomach, colors range from creamy white to bright yellow. While these snakes vary greatly in body color and pattern shape and color, their coloration allows them to blend seamlessly into the trees they inhabit. Adults can grow to over six feet in length, can be more than two inches in diameter and have large, bulky heads. Emerald Tree Boas have strong prehensile tails, meaning tails that can grasp objects such as branches, which they use to coil themselves around horizontal branches. During the day, they spend much of their time looped over a branch with their head in the center. At night, however, these nocturnal and non-venomous creatures extend their head downward to await an approaching meal. They are believed to live around twenty years . Emerald Tree Boas are viviparous, meaning that the embryos are developed and stay in the mother’s body until the offspring are born live. After a gestation period of about six months, females give to young that can vary in number widely from three to fourteen. Females do not care for their young after they are born. Males mature sexually at three to four years of age while females reach sexual maturity at four to five years. Young Emerald Tree Boas can be born green, red, orange or yellow. At about six months to one year of age, they begin to turn green, a process which can take up to one year.
An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, was the first practical electric light. It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century. It continued in use in more specialized applications where a high intensity point light source was needed, such as searchlights and movie projectors until after World War II. The carbon arc lamp is now obsolete for all of these purposes and is only still made for very specialized purposes where a high intensity UV source is needed. The term is now used to refer to gas discharge lamps, which produce light by an arc between metal electrodes through an inert gas in a glass bulb. The common fluorescent lamp is a low-pressure mercury arc lamp. The xenon arc lamp, which produces a high intensity white light, is now used in many of the applications which formerly used the carbon arc, such as movie projectors and searchlights. An arc is the discharge that occurs when a gas is ionized. A high voltage is pulsed across the lamp to "ignite" or "strike" the arc, after which the discharge can be maintained at a lower voltage. The "strike" requires an electrical circuit with an igniter and a ballast. The ballast is wired in series with the lamp and performs two functions. First, when the power is first switched on, the igniter/starter (which is wired in parallel across the lamp) sets up a small current through the ballast and starter. This creates a small magnetic field within the ballast windings. A moment later the starter interrupts the current flow from the ballast, which has a high inductance and therefore tries to maintain the current flow (the ballast opposes any change in current through it); it cannot, as there is no longer a 'circuit'. As a result, a high voltage appears across the ballast momentarily - to which the lamp is connected, therefore the lamp receives this high voltage across it which 'strikes' the arc within the tube/lamp. The circuit will repeat this action until the lamp is ionized enough to sustain the arc. When the lamp sustains the arc, the ballast performs its second function, to limit the current to that needed to operate the lamp. The lamp, ballast and igniter are rated matched to each other; these parts must be replaced with the same rating as the failed component or the lamp will not work. The colour of the light emitted by the lamp changes as its electrical characteristics change with temperature and time. Lightning is a similar principle where the atmosphere is ionized by the high potential difference (voltage) between earth and storm clouds. The temperature of the arc in an arc lamp can reach several thousand degrees Celsius. The outer glass envelope can reach 500 degrees Celsius, therefore before servicing one must ensure the bulb has cooled sufficiently to handle. Often, if these types of lamps are turned off or lose their power supply, one cannot restrike the lamp again for several minutes (called cold restrike lamps). However, some lamps (mainly fluorescent tubes/energy saving lamps) can be restruck as soon as they are turned off (called hot restrike lamps). The Vortek water-wall plasma arc lamp, invented in 1975 by David Camm and Roy Nodwell at the University of British Columbia Vancouver, Canada, made the Guinness Book of World Records in 1986 and 1993 as the most powerful continuously burning light source at over 300 kW or 1.2 million candle power. Carbon arc lamp In popular use, the term arc lamp means carbon arc lamp only. In a carbon arc lamp, the electrodes are carbon rods in free air. To ignite the lamp, the rods are touched together, thus allowing a relatively low voltage to strike the arc. The rods are then slowly drawn apart, and electric current heats and maintains an arc across the gap. The tips of the carbon rods are heated and the carbon vaporizes. The carbon vapor in the arc is highly luminous, which is what produces the bright light. The rods are slowly burnt away in use, and the distance between them needs to be regularly adjusted in order to maintain the arc. Many ingenious mechanisms were invented to effect this automatically, mostly based on solenoids. In one of the simplest mechanically-regulated forms (which was soon superseded by more smoothly acting devices) the electrodes are mounted vertically. The current supplying the arc is passed in series through a solenoid attached to the top electrode. If the points of the electrodes are touching (as in start up) the resistance falls, the current increases and the increased pull from the solenoid draws the points apart. If the arc starts to fail the current drops and the points close up again. The Yablochkov candle is a simple arc lamp without a regulator, but it has the drawbacks that the arc cannot be restarted (single use) and a limited lifetime of only a few hours. The concept of carbon-arc lighting was first demonstrated by Sir Humphry Davy in the early 19th century (1802, 1805, 1807 and 1809 are all mentioned), using charcoal sticks and a 2000-cell battery to create an arc across a 4-inch (100 mm) gap. He mounted his electrodes horizontally and noted that, because of the strong convection flow of air, the arc formed the shape of an arch. He coined the term "arch lamp", which was contracted to "arc lamp" when the devices came into common usage. The arc lamp provided one of the first commercial uses for electricity, a phenomenon previously confined to experiment, the telegraph, and entertainment. Carbon-arc lighting in the U.S. In the United States, there were attempts to produce arc lamps commercially after 1850 but the lack of a constant electricity supply thwarted efforts. Thus electrical engineers began focusing on the problem of improving Faraday's dynamo. The concept was improved upon by a number of people including William Staite and Charles F. Brush. It was not until the 1870s that lamps such as the Yablochkov candle were more commonly seen. In 1877, the Franklin Institute conducted a comparative test of dynamo systems. The one developed by Brush performed best, and Brush immediately applied his improved dynamo to arc-lighting an early application being Public Square in Cleveland, Ohio, on April 29, 1879. In 1880, Brush established the Brush Electric Company. The harsh and brilliant light was found most suitable for public areas, such as Cleveland's Public Square, being around 200 times more powerful than contemporary filament lamps. The usage of Brush electric arc lights spread quickly. Scientific American reported in 1881 that the system was being used in: - 800 lights in rolling mills, steel works, shops, etc. - 1,240 lights in woolen, cotton, linen, silk, and other factories - 425 lights in large stores, hotels, churches, etc. - 250 lights in parks, docks, and summer resorts - 275 lights in railroad depots and shops - 130 lights in mines, smelting works, etc. - 380 lights in factories and establishments of various kinds - 1,500 lights in lighting stations, for city lighting, etc. - 1,200 lights in England and other foreign countries. - A total of over 6,000 lights which are actually sold There were three major advances in the 1880s: - František Křižík invented in 1880 a mechanism to allow the automatic adjustment of the electrodes. - The arcs were enclosed in a small tube to slow the carbon consumption (increasing the life span to around 100 hours). - Flame arc lamps were introduced where the carbon rods had metal salts (usually magnesium, strontium, barium, or calcium fluorides) added to increase light output and produce different colours. In the U.S., patent protection of arc-lighting systems and improved dynamos proved difficult and as a result the arc-lighting industry became highly competitive. Brush's principal competition was from the team of Elihu Thomson and Edwin J. Houston. These two had formed the American Electric Corporation in 1880, but it was soon bought up by Charles A. Coffin, moved to Lynn, Massachusetts, and renamed the Thomson-Houston Electric Company. Thomson remained, though, the principal inventive genius behind the company patenting improvements to the lighting system. Under the leadership of Thomson-Houston's patent attorney, Frederick P. Fish, the company protected its new patent rights. Coffin's management also led the company towards an aggressive policy of buy-outs and mergers with competitors. Both strategies reduced competition in the electrical lighting manufacturing industry. By 1890, the Thomson-Houston company was the dominant electrical manufacturing company in the U.S. Nikola Tesla received U.S. Patent 447920, "Method of Operating Arc-Lamps" (March 10, 1891), that describes a 10,000 cycles per second alternator to suppress the disagreeable sound of power-frequency harmonics produced by arc lamps operating on frequencies within the range of human hearing. Around the turn of the century arc-lighting systems were in decline, but Thomson-Houston controlled key patents to urban lighting systems. This control slowed the expansion of incandescent lighting systems being developed by Thomas Edison's Edison General Electric Company. Conversely, Edison's control of direct current distribution and generating machinery patents blocked further expansion of Thomson-Houston. The roadblock to expansion was removed when the two companies merged in 1892 to form the General Electric Company. Arc lamps were used in some early motion-picture studios to illuminate interior shots. One problem was that they produce such a high level of ultra-violet light that many actors needed to wear sunglasses when off camera to relieve sore eyes resulting from the ultra-violet light. The problem was solved by adding a sheet of ordinary window glass in front of the lamp, blocking the ultra-violet. By the dawn of the "talkies", arc lamps had been replaced in film studios with other types of lights. In 1915, Elmer Ambrose Sperry began manufacturing his invention of a high-intensity carbon arc searchlight. These were used aboard warships of all navies during the 20th century for signaling and illuminating enemies. In the 1920s, carbon arc lamps were sold as family health products, a substitute for natural sunlight. Arc lamps were superseded by filament lamps in most roles, remaining in only certain niche applications such as cinema projection, followspots, and searchlights. Even in these applications conventional carbon arc lamps are being pushed into obsolescence by xenon arc lamps, but were still being manufactured as spotlights at least as late as 1982 and are still manufactured for at least one purpose - simulating sunlight in "accelerated aging" machines intended to estimate how fast a material is likely to be degraded by environmental exposure. - Electric light - High-intensity discharge lamp - Large-format slide projector - Léon Foucault - List of light sources - List of Nikola Tesla patents - Movie projector - Pavel Yablochkov and Yablochkov candle - Shielded metal arc welding - Stage lighting - Timeline of lighting technology - Walther Nernst - Whelan, M. (2013). "Arc Lamps". Resources. [Edison Tech Center http://www.edisontechcenter.org/] website, Schenectady, New York. Retrieved November 22, 2014. External link in - Chen, Kao (1990). "Fluorescent Lamps". Industrial Power Distribution and Illuminating Systems. Electrical Engineering and Electronics. 65. New York: Dekker. p. 350. ISBN 978-0-8247-8237-5. The fluorescent lamp is ... activated by ... a low-pressure mercury arc. - Voyer, Roger (1994). The New Innovators: How Canadians Are Shaping the Knowledge-Based Economy. Toronto: James Lorimer & Company Ltd. p. 20. ISBN 1-55028-463-0. - Slingo, William; Brooker, Arthur (1900). Electrical Engineering for Electric Light Artisans. London: Longmans, Green and Co. p. 607. OCLC 264936769 - Gilbert, Gerard. Critic's Choice The Independent, 6 October 2011 - "Cleveland+ Public Art" (brochure). Positively Cleveland. 2008. p. 3. Retrieved 2009-05-18. - "The Brush Electric Light". Scientific American. 44 (14). April 2, 1881.; also Ohio Memory Collection cover reproduction - David F. Noble, America By Design: Science, Technology, and the Rise of Corporate Capitalism (New York: Oxford University Press, 1977), 6-10. - I. C. B. Dear and Peter Kemp, eds., "Sperry, Elmer Ambrose," The Oxford Companion to Ships and the Sea, 2nd ed. (New York: Oxford University Press, 2006). ISBN 0-19-920568-X - "Eveready Carbon Arc Sunshine Lamp Advertisements". The Einhorn Press. Retrieved 11 November 2008. - Braverman, Harry (1974). Labor and Monopoly Capital. New York: Monthly Review Press. - MacLaren, Malcolm (1943). The Rise of the Electrical Industry during the Nineteenth Century. Princeton: Princeton University Press. - Noble, David F. (1977). America by Design: Science, Technology, and the Rise of Corporate Capitalism. New York: Oxford University Press. pp. 6–10. - Prasser, Harold C. (1953). The Electrical Manufacturers. Cambridge: Harvard University Press. \|Wikimedia Commons has media related to Arc lamp.\| - Arc Lamp - Interactive Tutorial National High Magnetic Field Laboratory
has been made possible in part by: for this exhibition can be found by In the silver mines of South America, as much as 100,000 metric tons of silver were produced between 1500 and 1800. One of the most famous South American mines was located on the mountain of Potosi, in the nation of Bolivia. Potosi produced great amounts of silver that provided enormous wealth for Spain. The Native Americans, or Indians as the Spaniards called them, were put to work, mining the land. The Spanish encountered problems using Indians as slaves. They found the Indians could not handle the heavy labor that was required to work in the mines. They also had little resistance to European diseases such as smallpox and typhus, and they began to die by the thousands. Enslaved Africans were put work in the mines to replace the Indians. Spanish records show more and more Africans were requested and that the Spaniards considered Africans to be essential in the operation of the mines. Africans were rewarded by their hard work and received special privileges the Indians did not get, such as the right to carry weapons and wear European clothing. Miners would work from dawn to dusk, and it is estimated that the average working life of a miner was six to eight years. They were subjected to hard labor in dark, poorly ventilated tunnels and exposed to the dangers of cave-ins, floods, fires, and explosions. Despite the working conditions, Africans preferred mining to plantation work. Miners were allowed more freedom of movement, and they received rations of tobacco and brandy. They had opportunities to enrich themselves as well. Mine owners often allowed slaves to prospect for themselves once they met a certain quota. By such means, many mine workers were able to purchase their freedom. Some migrated to cities where they found new trades, but many remained in the mining areas and continued to work as independent prospectors.
Why in a thunder and lightning storm could the sky be pink and orange? Depending on local atmospheric conditions, lightning traveling through open air emits white light, but can appear in different colors. In snowstorms, pink and green are often described as colors of lightning. Particles in the atmosphere $uck as haze, dust, moisture and raindrops affect the color by absorbing or diffracting a portion of the white light of lightning. The same way the setting sun does, distant lightning can appear red or orange. Light emitted by lightning has similar visible spectrum as sunlight, so the atmosphere should shift the colors of both the same way (given there is enough distance between the lightning and the observer). Lightning is one of the leading weather-related causes of death and injury in the United States. Most people do not realize that they can be struck by lightning even when the center of a thunderstorm is 10 miles (16 kilometers) away and there are blue skies overhead. Read Flash Facts About Lightning, organized by the National Oceanic and Atmospheric Administration (NOAA). Lightning kills as many as 2,000 people worldwide every year. Read tips on what you can do to avoid electrical storms or decrease your chances of getting struck at National Geographic.
This chapter was copied with permission from Nick Strobel’s Astronomy Notes. Go to his site at www.astronomynotes.com for the updated and corrected version. This chapter has been edited for content. Text that has been altered from the original is denoted in green font. Astronomy Without a Telescope I discuss the celestial sphere, motions of the Sun (solar and sidereal days, time zones, equation of time, and seasons), motions of the Moon (phases and eclipses), and planetary motions. Now that you have some feeling for the scales of time and space that astronomy encompasses and some of the difficulties caused by being Earth-bound (well, okay: solar-system bound!), let’s take a look at what is up there in the sky beyond the clouds. In this chapter, you will learn where to find the key points on the night sky, how to use the coordinate system that astronomers use, how the Sun’s position among the stars changes and how that affects the temperature throughout the year, and about the phases of the Moon and eclipses. At the end of chapter, you will learn about the motions of the planets among the stars. All of the things in this chapter, you can observe without a telescope—naked eye astronomy (note to Jesse Helms and Sen. Exon: that means astronomy without the use of a telescope). You just need to observe the objects carefully and notice how things change over time. The vocabulary terms are in boldface. 3.2 Celestial Sphere Defined Imagine the sky as a great, hollow, sphere surrounding the Earth. The stars are attached to this sphere—some bigger and brighter than others—which rotates around the stationary Earth roughly every 24 hours. Alternatively, you can imagine the stars as holes in the sphere and the light from the heavens beyond the sphere shines through those holes. This imaginary sphere is called the celestial sphere, and has a very large radius so that no part of the Earth is significantly closer to any given star than any other part. Therefore, the sky always looks like a great sphere centered on your position. The celestial sphere (and, therefore, the stars) appears to move westward—stars rise in the east and set in the west. Even though it is now known that this ancient model of a stationary Earth is incorrect, you can still use this model because it is a convenient way to predict the motions of the stars and planets relative to a location on the Earth. A star’s apparent brightness is actually determined by its distance, as well as, its physical size and temperature. It is also now known that the stars apparent motion around us is due to the Earth rotating once every 24 hours on its axis. The stars are stationary and the Earth rotates from west to east. This rotational motion makes the stars appear to move from east to west around us. The celestial sphere model is used by planetaria to simulate the night sky. I hope you will be able to distinguish between the convenience of the celestial sphere model and the way things really are. Why a sphere? The Earth is spherical! This was known much earlier than Columbus’ time. Sailors had long known that as a ship sailed away from the shore it not only diminished in apparent size, but it also appeared to sink into the water. The simplest explanation to use was that the Earth was curved (particularly, since those ships did come back without falling off some edge!). They also knew that if one traveled in a north-south direction, some stars disappeared from view while others appeared. The difference in the height of a star’s height above the north or south horizon is directly proportional to the difference in the north-south distance of observers looking at the star at the same time. The simplest explanation said that the Earth is round, not flat. Pythagoras noted that the shadow of the Earth falling on the Moon during a lunar eclipse was always curved and the amount of the curvature was always the same. The only object that always casts a circular shadow regardless of its orientation is a sphere. This Pythagorean argument is passed on to us through the writings of Aristotle. - celestial sphere Review Questions 1 - How does the sky appear to move around us? - What motion of the Earth produces the apparent motion of the stars around us? To measure distances on the imaginary celestial sphere, you use “angles on the sky” instead of meters or kilometers. There are 360 degrees in a full circle and 90 degrees in a right angle (two perpendicular lines intersecting each other make a right angle). Each degree is divided into 60 minutes of arc. A quarter viewed face-on from across the length of a football field is about 1 arc minute across. Each minute of arc is divided into 60 seconds of arc. The ball in the tip of a ballpoint pen viewed from across the length of a football field is about 1 arc second across. The Sun and Moon are both about 0.5 degrees = 30 arc minutes in diameter. The pointer stars in the bowl of the Big Dipper are about 5 degrees apart and the bowl of the Big Dipper is about 30 degrees from Polaris, the North Star that is very close to the North Celestial Pole. Some angles using your hand held at arm’s length are described in the figure below. The arc from the north point on the horizon to the point directly overhead to the south point on the horizon is 180 degrees, so any object directly overhead is 90 degrees above the horizon and any object “half-way up” in the sky is about 45 degrees above the horizon. Review Questions 2 - How many degrees is 30 arc minutes? - How many degrees is 10 arc seconds? - How many Moon diameters would it take to span the distance from a point on the eastern horizon to a point directly opposite on the western horizon? 3.4 Reference Markers Now for some reference makers: The stars rotate around the North and South Celestial Poles. These are the points in the sky directly above the geographic north and south pole, respectively. The Earth’s axis of rotation intersects the celestial sphere at the celestial poles. The number of degrees the celestial pole is above the horizon is equal to the latitude of the observer. Fortunately, for those in the northern hemisphere, there is a fairly bright star real close to the North Celestial Pole (Polaris or the North star). Another important reference marker is the celestial equator: an imaginary circle around the sky directly above the Earth’s equator. It is always 90 degrees from the poles. All the stars rotate in a path that is parallel to the celestial equator. The celestial equator intercepts the horizon at the points directly east and west anywhere on the Earth. If you joined Santa last Christmas at the north pole (90 degrees latitude), you would have seen Polaris straight overhead and the celestial equator on your horizon. The point straight overhead on the celestial sphere for any observer is called the zenith and is always 90 degrees from the horizon. The arc that goes through the north point on the horizon, zenith, and south point on the horizon is called the meridian. The positions of the zenith and meridian with respect to the stars will change as the celestial sphere rotates and if the observer changes locations on the Earth, but those reference marks do not change with respect to the observer’s horizon. Any celestial object crossing the meridian is at its highest altitude (distance from the horizon) during that night (or day). The angle the star paths make with respect to the horizon as they rise up or set down = 90 degrees minus the observer’s latitude. At the north pole, the latitude = 90 degrees so the stars paths make an angle of 90 minus 90 degrees = 0 degrees with respect to the horizon—i.e., they move parallel to the horizon as shown in the figure above. For locations further south you will see in the figures below that the stars will rise up (and then set down) at steeper angles as you get closer to the equator. During daylight, the meridian separates the morning and afternoon positions of the Sun. In the morning the Sun is “ante meridiem” (Latin for “before meridian”) or east of the meridian, abbreviated “a.m.” At local noon the Sun is right on the meridian (the reason why this may not correspond to 12:00 on your clock is discussed a little later in this chapter). At local noon the Sun is due south for northern hemisphere observers and due north for southern hemisphere observers (though observers near the Earth’s equator can see the local noon Sun due north or due south at different times of the year for reasons given in the next section). In the afternoon the Sun is “post meridiem” (Latin for “after meridian”) or west of the meridian, abbreviated “p.m.” For each degree you move south with Santa in his sleigh, the North Celestial Pole (NCP from here on) moves 1 degree away from the zenith toward the north and the highest point of the celestial equator’s curved path in the sky moves up one degree from the southern horizon. This effect has nothing to do with the distance between a celestial object or marker and you at different points on the Earth (remember that the celestial sphere has a practically infinite radius). In fact, observers on a spherical world only ten miles across would see the same effect! The picture above shows the celestial sphere for the far northern city of Fairbanks in Alaska. Since it is 25° south of the north pole, the NCP is 25° away from (north of) the zenith for Fairbanks observers. By the time you reach your hometown, the NCP has moved away from the zenith so it is now a number of degrees above the horizon equal to your latitude on the Earth. Remember that your position on the Earth is specified by a latitude and a longitude coordinate. The latitude is the number of degrees north or south of the Earth’s equator. On a map or globe, lines of latitude run horizontally, parallel to the equator. The longitude is the number of degrees east or west of the 0° longitude line (the “prime meridian” on the Earth) that runs through Greenwich England. On a map or globe, lines of longitude run vertically, perpendicular to the equator. The celestial sphere for observers in Seattle and any other observer at the same latitude (47° N) on the Earth is shown above. For another more detailed example, let’s choose Los Angeles at latitude 34° N. The NCP is therefore 34 degrees above the north horizon. The diagram for latitude 34° N is shown above. Notice that finding the angle of the NCP above the horizon provides a very easy way of determining your latitude on the Earth (a fact used by navigators even today!). Because the Earth’s equator is 90° away from the north pole, the celestial equator as seen in Los Angeles will arc up to 90 – 34 = 56 degrees above the southern horizon at the point it crosses the meridian. It still intercepts the horizon at the exactly east and west points. The stars rise in the east part of the sky, move in arcs parallel to the celestial equator reaching maximum altitude when they cross your meridian, and set in the west part of the sky. The star paths make an angle of 90 – 34 = 56 degrees with respect to the horizon. If you are in the northern hemisphere, celestial objects north of the celestial equator are above the horizon for more than 12 hours because you see more than half of their total 24-hour path around you. Celestial objects on the celestial equator are up 12 hours and those south of the celestial equator are above the horizon for less than 12 hours because you see less than half of their total 24-hour path around you. The opposite is true if you are in the southern hemisphere. Notice that stars closer to the NCP are above the horizon longer than those farther away from the NCP. Those stars within an angular distance from the NCP equal to the observer’s latitude are above the horizon for 24 hours—they are circumpolar stars. Also, those stars close enough to the SCP (within a distance = observer’s latitude) will never rise above the horizon. They are also called circumpolar stars. To warm Rudolph’s frozen nose, Santa heads down to the equator (0 degrees latitude). At the equator, you see the celestial equator arcing from exactly east to the zenith to exactly west. The NCP is on your northern horizon. At the equator you see one-half of every star’s total 24-hour path around you so all stars are up for 12 hours. All of the stars rise and set perpendicular to the horizon (at an angle = 90 – 0 = 90 degrees). Continuing southward you see the NCP disappear below the horizon and the SCP rise above the southern horizon one degree for every one degree of latitude south of the equator you go. The arc of the celestial equator moves to the north, but the arc still intercepts the horizon at the exactly east/west points. Here is a summary of the positions of the celestial reference marks (note that “altitude” means the number of degrees above the horizon): - Meridian always goes through due North, zenith, and due South points. - Altitude of zenith = 90° (straight overhead) always. - Altitude of celestial pole = observer’s latitude. Observers in northern hemisphere see NCP; observers in southern hemisphere see SCP. - Altitude of celestial equator on meridian = 90 minus the observer’s latitude. - Celestial equator always intercepts horizon at exactly East and exactly West points. - Angle celestial equator (and any star path) makes with respect to the horizon = 90 minus the observer’s latitude. - Stars move parallel to the celestial equator. - Circumpolar object’s distance from celestial pole = observer’s latitude. (You’ll want your web browser to fill most of your screen!) Check out the Rotating Sky module from the University of Nebraska-Lincoln’s Astronomy Education program to explore the connection between your position on the Earth and the path of the stars (link will appear in a new window—choose the “Rotating Sky” part). - celestial equator - North Celestial Pole - South Celestial Pole Review Questions 3 - How do the positions of the celestial equator, celestial poles, zenith, and meridian depend on the latitude of the observer? - Would their position with respect to the horizon change if the Earth were only 200 miles in diameter? How about 80,000 miles in diameter? Why is that? - During a night, how do the stars move? What angle does their nightly path make with respect to the horizon? How does it depend on latitude? - What reference point is a celestial object on when it is at its highest position above the horizon? - Why do observers in the northern hemisphere see celestial objects above the celestial equator for more than 12 hours? - For northern hemisphere observers, which celestial object would be above the horizon for the greatest amount of time: one that is on the celestial equator, one that is 30° above the celestial equator, one that is 70° above the celestial equator, or one that is 40° below the celestial equator? Which one would be above the horizon the greatest amount of time for southern hemisphere observers? Explain your answer. 3.5 Motion of Our Star the Sun Now that you have your bearings, let’s take a look at the position and motion of the closest star to us, the Sun. Every day the Sun rises in an easterly direction, reaches maximum height when it crosses the meridian at local noon, and sets in a westerly direction and it takes the Sun on average 24 hours to go from noon position to noon position the next day. The “noon position” is when the Sun is on the meridian on a given day. Our clocks are based on this solar day. The exact position on the horizon of the rising and setting Sun varies throughout the year (remember though, the celestial equator always intercepts the horizon at exactly East and exactly West). Also, the time of the sunrise and sunset changes throughout the year, very dramatically so if you live near the poles, so the solar day is measured from “noon to noon.” The Sun appears to drift eastward with respect to the stars (or lag behind the stars) over a year’s time. It makes one full circuit of 360 degrees in 365.24 days (very close to 1 degree or twice its diameter per day). This drift eastward is now known to be caused by the motion of the Earth around the Sun in its orbit. The apparent yearly path of the Sun through the stars is called the ecliptic. This circular path is tilted 23.5 degrees with respect to the celestial equator because the Earth’s rotation axis is tilted by 23.5 degrees with respect to its orbital plane. Be sure to keep distinct in your mind the difference between the slow drift of the Sun along the ecliptic during the year and the fast motion of the rising and setting Sun during a day. The ecliptic and celestial equator intersect at two points: the vernal (spring) equinox and autumnal (fall) equinox. The Sun crosses the celestial equator moving northward at the vernal equinox around March 21 and crosses the celestial equator moving southward at the autumnal equinox around September 22. When the Sun is on the celestial equator at the equinoxes, everybody on the Earth experiences 12 hours of daylight and 12 hours of night for those two days (hence, the name “equinox” for “equal night”). The day of the vernal equinox marks the beginning of the three-month season of spring on our calendar and the day of the autumn equinox marks the beginning of the season of autumn (fall) on our calendar. On those two days of the year, the Sun will rise in the exact east direction, follow an arc right along the celestial equator and set in the exact west direction. When the Sun is above the celestial equator during the seasons of spring and summer, you will have more than 12 hours of daylight. The Sun will rise in the northeast, follow a long, high arc north of the celestial equator, and set in the northwest. Where exactly it rises or sets and how long the Sun is above the horizon depends on the day of the year and the latitude of the observer. When the Sun is below the celestial equator during the seasons of autumn and winter, you will have less than 12 hours of daylight. The Sun will rise in the southeast, follow a short, low arc south of the celestial equator, and set in the southwest. The exact path it follows depends on the date and the observer’s latitude. Make sure you understand this. No matter where you are on the Earth, you will see 1/2 of the celestial equator’s arc. Since the sky appears to rotate around you in 24 hours, anything on the celestial equator takes 12 hours to go from exact east to exact west. Every celestial object’s diurnal (daily) motion is parallel to the celestial equator. So for northern observers, anything south of the celestial equator takes less than 12 hours between rise and set, because most of its rotation arc around you is hidden below the horizon. Anything north of the celestial equator takes more than 12 hours between rising and setting because most of its rotation arc is above the horizon. For observers in the southern hemisphere, the situation is reversed. However, remember, that everybody anywhere on the Earth sees 1/2 of the celestial equator so at the equinox, when the Sun is on the equator, you see 1/2 of its rotation arc around you, and therefore you have 12 hours of daylight and 12 hours of nightime everyplace on the Earth. The geographic poles and equator are special cases. At the geographic poles the celestial equator is right along the horizon and the full circle of the celestial equator is visible. Since a celestial object’s diurnal path is parallel to the celestial equator, stars do not rise or set at the geographic poles. On the equinoxes the Sun moves along the horizon. At the North Pole the Sun “rises” on March 21st and “sets” on September 22. The situation is reversed for the South Pole. On the equator observers see one half of every object’s full 24-hour path around them, so the Sun and every other star is above the horizon for exactly 12 hours for every day of the year. Since the ecliptic is tilted 23.5 degrees with respect to the celestial equator, the Sun’s maximum angular distance from the celestial equator is 23.5 degrees. This happens at the solstices. For observers in the northern hemisphere, the farthest northern point above the celestial equator is the summer solstice, and the farthest southern point is the winter solstice. The word “solstice” means “sun standing still” because the Sun stops moving northward or southward at those points on the ecliptic. The Sun reaches winter solstice around December 21 and you see the least part of its diurnal path all year—this is the day of the least amount of daylight and marks the beginning of the season of winter for the northern hemisphere. On that day the Sun rises at its furthest south position in the southeast, follows its lowest arc south of the celestial equator, and sets at its furthest south position in the southwest. The Sun reaches the summer solstice around June 21 and you see the greatest part of its diurnal path above the horizon all year—this is the day of the most amount of daylight and marks the beginning of the season of summer for the northern hemisphere. On that day the Sun rises at its furthest north position in the northeast, follows its highest arc north of the celestial equator, and sets at its furthest north position in the northwest. The seasons are opposite for the southern hemisphere (e.g., it is summer in the southern hemisphere when it is winter in the northern hemisphere). The Sun does not get high up above the horizon on the winter solstice. The Sun’s rays hit the ground at a shallow angle at mid-day so the shadows are long. On the summer solstice the mid-day shadows are much shorter because the Sun is much higher above the horizon. To check your understanding of the concepts in this section (and improve it!), go through the Motions of the Sun module of the University of Nebraska-Lincoln’s Astronomy Education program (link will appear in a new window). One section of the module will also cover solar and sidereal time that Astronomy Notes covers in a later section. - autumnal (fall) equinox - solar day - summer solstice - vernal (spring) equinox - winter solstice Review Questions 4 - How does the Sun move with respect to the stars during the year? - Why does everyone have 12 hours of daylight on the equinoxes? - Why is the length of daylight in the northern hemisphere so short on December 21? - When will the Sun be at its highest altitude in the year in Los Angeles or Seattle? How about Singapore (on the Equator)? Why? - On what date is the Sun above the horizon the shortest amount of time for the Southern Hemisphere? Why? Early astronomy concentrated on finding accurate positions of the stars and planets. This was due in part to the influence of astrology, but later, accurate positions came to be important for determining the physical characteristics of the stars and planets. Accurate positions for the stars was also crucial for commercial and military navigation (navigation by the stars has only recently been replaced by the use of satellite systems such as the Global Positioning System). But probably of more importance to you is where to point your telescope or binoculars to find that cool object talked about in the newspaper or astronomy magazine. There are a couple of popular ways of specifying the location of a celestial object. The first is what you would probably use to point out a star to your friend: the altitude-azimuth system. The altitude of a star is how many degrees above the horizon it is (anywhere from 0 to 90 degrees). The azimuth of a star is how many degrees along the horizon it is and corresponds to the compass direction. Azimuth starts from exactly North = 0 degrees azimuth and increases clockwise: exactly East = 90 degrees, exactly South = 180 degrees, exactly West = 270 degrees, and exactly North = 360 degrees = 0 degrees. For example, a star in the southwest could have an azimuth between 180 degrees and 270 degrees. Since stars change their position with respect to your horizon throughout the night, their altitude-azimuth position changes. Also, observers at different locations looking at the same star at the same time will see it at a different altitude-azimuth position. A concise summary of this coordinate system and the numbers involved is given at the end of this section. The second way of specifying star positions is the equatorial coordinate system. This system is very similar to the longitude-latitude system used to specify positions on the Earth’s surface. This system is fixed with respect to the stars so, unlike the altitude-azimuth system, a star’s position does not depend on the observer’s location or time. Because of this, astronomers prefer using this system. You will find this system used in astronomy magazines and in most sky simulation computer software. Selecting the image link will bring up a short animation of a spinning celestial sphere. The lines on a map of the Earth that run north-south are lines of longitude and when projected onto the sky, they become lines of right ascension. Because the stars were used to measure time, right ascension (RA) is measured in terms of hours, minutes, and seconds instead of degrees and increases in an easterly direction. For two stars one hour of RA apart, you will see one star cross your meridian one hour of time before the other. If the stars are not circumpolar, you will see one star rise one hour before the other. If they were 30 minutes of RA apart, you would see one rise half an hour before the other and cross your meridian half an hour before the other. Zero RA is where the Sun crosses the celestial equator at the vernal equinox. The full 360 degrees of the Earth’s rotation is broken up into 24 hours, so one hour of RA = 15 degrees of rotation. The lines of RA all converge at the celestial poles so two stars one hour of RA apart will not necessarily be 15 degrees in angular separation on the sky (only if they are on the celestial equator will they be 15 degrees apart). The lines on a map of the Earth that run east-west parallel to the equator are lines of latitude and when projected onto the sky, they become lines of declination. Like the latitude lines on Earth, declination (dec) is measured in degrees away from the celestial equator, positive degrees for objects north of the celestial equator and negative degrees for objects south of the celestial equator. Objects on the celestial equator are at 0 degrees dec, objects half-way to the NCP are +45 degrees, objects at the NCP are +90 degrees, and objects at the SCP are -90 degrees. Polaris’s position is at RA 2hr 31min and dec 89 degrees 15 arc minutes. A concise summary of this coordinate system and the numbers involved is given at the end of this section. The Basic Coordinates module of the University of Nebraska-Lincoln’s Astronomy Education program provides a great way to make the connection between terrestrial coordinates (longitude and latitude) and the equatorial coordinate system (link will appear in a new window). The first part of the module has you drag a cursor around on a flat world map or globe and read off its terrestrial coordinate position. The second part of the module has you do the same sort of thing using a flat map of the sky or a globe of the celestial sphere and read off the right ascension and declination. Both parts also illustrate the distortion that happens when you project a curved spherical surface onto a flat two-dimensional map. The UNL Astronomy Education’s Rotating Sky module has you explore the connection between the two coordinate systems. You can change your location on the Earth and adjust the position of multiple stars and see where the stars would appear and how they would move on the celestial sphere and around your position on the Earth as the Earth rotates beneath the stars. An effect called precession causes the Sun’s vernal equinox point to slowly shift westward over time, so a star’s RA and dec will slowly change by about 1.4 degrees every century (a fact ignored by astrologers), or about 1 minute increase in a star’s RA every twenty years. This is caused by the gravitational pulls of the Sun and Moon on the Earth’s equatorial bulge (from the Earth’s rapid rotation) in an effort to reduce the tilt of the Earth’s axis with respect to the ecliptic and the plane of the Moon’s orbit around the Earth (that is itself slightly tipped with respect to the ecliptic). Like the slow wobble of a rapidly-spinning top, the Earth responds to the gravitational tugs of the Sun and Moon by slowly wobbling its rotation axis with a period of 26,000 years. This motion was first recorded by Hipparchus in 100 B.C.E. who noticed differences between ancient Babylonian observations and his own. When the Babylonians were the world power in 2000 B.C.E., the vernal equinox was in the constellation Aries and the star Thuban (in Draco) was the closest bright star to the NCP. At the time of Jesus Christ the vernal equinox had shifted to the constellation Pisces and the star Kochab (in the bowl of the Little Dipper) was the closest bright star to the NCP. Now the star Polaris is close to the NCP and the vernal equinox is close to the border between Pisces and Aquarius (in 2600 C.E. it will officially be in Aquarius) which is what a popular song of years ago refers to with the line “this is the dawning of the Age of Aquarius.” In the year 10,000 C.E., the bright star in the tail of Cygnus, Deneb, will be the pole star and Vega (in Lyra) will get its turn by the year 14,000 C.E. Horoscopes today are still based on the 4,000-year old Babylonian system so even though the Sun is in Aries on my birthday, the zodiac sign used for my horoscope is Taurus. I guess it’s hard to keep up with all of the changes in the modern world! Star Chart sites (These will appear in another window) - National Geographic Society’s Star Chart with Hubble image enhancements. Select a particular section of the sky on the image map. Locations of objects imaged by Hubble are hyper-linked on the section you selected. The grid lines are lines of right ascension and declination. - Interactive Star Chart. Choose a constellation as your starting point for this viewer of the skies. Your browser must be java-enabled. - Your Sky is a free interactive planetarium simulator on the web. Use it to create a sky map of the entire sky or a horizon view as seen from your location on the Earth. - Monthly evening sky maps are available for free from Skymap.com. The star charts show the entire sky with a white sky background and black stars and include a calendar of astronomical events for the month. - Sky and Telescope‘s Interactive Sky Chart (login required) is another free star chart service. Create a chart of the entire sky or a horizon view from your location on the Earth. You can also create a PDF of the chart for printing that has a white sky and black stars. - right ascension - Altitude varies from 0 to 90°. Vertical position of object. - Azimuth varies from 0° to 360°. Exact N = 0°, exact E = 90°, exact S = 180°, exact W = 270°. Horizontal position of object. - Right ascension varies from 0 to 24 hours, so every hour corresponds to a rotation angle of 15°. Horizontal position of object measured in time units. - Declination varies from -90° (at SCP) to +90° (at NCP). Celestial equator declination = 0°. Vertical position of object. - Meridian altitude of any object = 90 – (observer’s latitude) + declination degrees. If declination is negative, then addition of declination becomes a subtraction. Formulae for Sun’s position - Ecliptic tilted by 23.5° with respect to the celestial equator. - Sun’s declination ranges between -23.5° and +23.5°. - Vernal equinox right ascension = 0 hours; declination = 0°; Sun rises at 90° azimuth and sets at 270° azimuth. - June solstice right ascension = 6 hours; declination = +23.5°; Sun rises at less than 90° azimuth and sets at greater than 270° azimuth. - Autumnal equinox right ascension = 12 hours; declination = 0°; Sun rises at 90° azimuth and sets at 270° azimuth. - December solstice right ascension = 18 hours; declination = -23.5° Sun rises at greater than 90° azimuth and sets at less than 270° azimuth. Review Questions 5 - At what two azimuths does the celestial equator intercept the horizon? - If a star’s position at 10 pm is 110° azimuth and 40° altitude, will its azimuth be greater or less at 11 pm? If the star is still east of the meridian at 11 pm, will its altitude be greater or less than it was at 10 pm? First assume you are in the northern hemisphere. Explain your answer. Then assume you are in the southern hemisphere and explain your answer. - Why do astronomers prefer using right ascension and declination? - What is the azimuth of any object when it crosses the meridian at any time of year in the southern sky? - If a star has a RA of 5 hours and crosses the meridian at 10:45 pm, what is the RA of a star that crosses the meridian at 1:00 am? Explain your answer. - What is the Sun’s altitude when it crosses the meridian in your home town and its declination is +23.5°? - What is the altitude of the NCP at Fairbanks, Alaska (lat. = 65° N)? - How do the positions of the equinoxes and solstices with respect to the horizon depend on the latitude? - What is the maximum altitude of the Sun on the vernal equinox for people on the equator? What is the Sun’s right ascension at that time? - What will the Sun’s declination be on the following dates: June 21, March 21, September 22, and December 21? - If the Sun sets 10° away from due West on October 20, what is the sunset azimuth? - If the Sun rises 12° away from due East on April 19, what is the sunrise azimuth? - What causes precession? - How does precession affect the positions of the stars? - If a star on the celestial equator has a RA of 5 hours 33 minutes, what would you estimate its RA to be in 20 years and in 200 years? Explain your answer. (Remember that the Earth spins about 15°/hour.) - Which star is the current pole star? Which star was the pole star 2,000 years ago? Which star will be the pole star 8,000 years from now? - Are modern horoscopes based on the current motion of the Sun and planets with respect to stars? The fact that our clocks are based on the solar day and the Sun appears to drift eastward with respect to the stars (or lag behind the stars) by about 1 degree per day means that if you look closely at the positions of the stars over a period of several days, you will notice that according to our clocks, the stars rise and set 4 minutes earlier each day. Our clocks say that the day is 24 hours long, so the stars move around the Earth in 23 hours 56 minutes. This time period is called the sidereal day because it is measured with respect to the stars. This is the true rotation rate of the Earth and stays the same no matter where the Earth is in its orbit—the sidereal day = 23 hours 56 minutes on every day of the year. One month later (30 days) a given star will rise 2 hours earlier than it did before (30 days × 4 minutes/day = 120 minutes). A year later that star will rise at the same time as it did today. Another way to look at it is that the Sun has made one full circuit of 360 degrees along the ecliptic in a year of 365.24 days (very close to 1 degree per day). The result is that between two consecutive meridian crossings of the Sun, the Earth has to turn nearly 361 degrees, not 360 degrees, in 24 hours. This makes the length of time for one solar day to be a little more than the true rotation rate of 23 hours 56 minutes with respect to the background stars. 3.7.2 Solar and Sidereal Time as Viewed from Space Let’s jump to a more modern view and take a position off the Earth and see the Earth revolving around the Sun in 365.24 days and rotating on its axis every 23 hours 56 minutes. The Earth’s rotation plane is tilted by 23.5 degrees from its orbital plane which is projected against the background stars to form the ecliptic. Note that the Earth’s rotation axis is always pointed toward the Celestial Poles. Currently the North Celestial Pole is very close to the star Polaris. The figure above shows this view of the Earth’s nearly circular orbit from slightly above the orbital plane (hence, the very elliptical appearance of the orbit). Imagine that at noon there is a huge arrow that is pointing at the Sun and a star directly in line behind the Sun. The observer on the Earth sees the Sun at its highest point above the horizon: on the arc going through the north-zenith-south points, which is called the meridian. The observer is also experiencing local noon. If the Sun were not there, the observer would also see the star on the meridian. Now as time goes on, the Earth moves in its orbit and it rotates from west to east (both motions are counterclockwise if viewed from above the north pole). One sidereal period later (23 hours 56 minutes) or one true rotation period later, the arrow is again pointing toward the star. The observer on the Earth sees the star on the meridian. But the arrow is not pointing at the Sun! In fact the Earth needs to rotate a little more to get the arrow lined up with the Sun. The observer on the Earth sees the Sun a little bit east of the meridian. Four minutes later or one degree of further rotation aligns the arrow and Sun and you have one solar day (24 hours) since the last time the Sun was on the meridian. The geometry of the situation also shows that the Earth moves about 1 degree in its orbit during one sidereal day. That night the Earth observer will see certain stars visible like those in Taurus, for example. (Notice that the Earth’s rotation axis is still pointed toward Polaris.) A half of a year later Taurus will not be visible but those stars in Scorpius will be visible. (Again, notice that the Earth’s rotation axis is still pointed toward Polaris.) The extra angle any planet must rotate on its axis to get the Sun back to the meridian equals the angle amount the planet moved in its orbit in one sidereal day. The amount of time it takes to spin the extra angle = (extra angle amount)/(spin rate). For the Earth, the spin rate = 360°/23.9333 hours = 15°/hour or 1°/4 minutes. Notice that I converted 23 hours 56 minutes to a decimal fraction of hours before I did the division. The amount of time between the solar day and sidereal day = (1 degree)/(1 degree/4 minutes) = 4 minutes. The Earth’s sidereal day is always 23 hours 56 minutes long because the number of degrees the Earth spins through in a given amount of time stays constant. If you are a careful observer, you will notice that the solar day is sometimes slightly longer than 24 hours and sometimes slightly shorter than 24 hours during the year. The reason for this is that the Earth’s orbit around the Sun is elliptical and that the Sun’s motion is not parallel to the celestial equator. The effects of this are explained fully in the Equation of Time section below. The value of 24 hours for the solar day is an average for the year and is what our time-keeping system is based on. The precession of the Earth’s rotation axis introduces another difference between sidereal time and solar time. This is seen in how the year is measured. A year is defined as the orbital period of the Earth. However, if you use the Sun’s position as a guide, you come up with a time interval about 20 minutes shorter than if you use the stars as a guide. The time required for the constellations to complete one 360° cycle around the sky and to return to their original point on our sky is called a sidereal year. This is the time it takes the Earth to complete exactly one orbit around the Sun and equals 365.2564 solar days. The slow shift of the star coordinates from precession means that the Sun will not be at exactly the same position with respect to the celestial equator after one sidereal year. The tropical year is the time interval between two successive vernal equinoxes. It equals 365.2422 solar days and is the year our calendars are based on. After several thousand years the 20 minute difference between sidereal and tropical years would have made our summers occur several months earlier if we used a calendar based on the sidereal year. - local noon - sidereal day - sidereal year - tropical year Review Questions 6 - Which is used for our clocks—sidereal day or solar day? Why? - Why is there a difference between the sidereal day and solar day? - If the Earth rotated twice as quickly as it does now, what would be the difference in minutes between the solar and sidereal days? Explain how you got your answer. - If the Earth’s year was twice as long as it is now, what would be the difference in minutes between the solar and sidereal days? Explain! - Mars rotates once every 24.623 hours (its sidereal day) and it orbits the Sun once every 686.98 solar earth days. Show how to find out how long a solar day is on Mars. 3.7.3 Time Zones People east of you will see the Sun on their meridian before you see it on yours. Those in Denver, Colorado will see the Sun on their meridian about 52 minutes before people in Los Angeles will see the Sun on their meridian. Denver residents experience local noon about 52 minutes before those in Los Angeles. That is because Denver is at longitude 105° West longitude while Los Angeles is at 118° West longitude (or 13° difference). For each one degree difference in longitude a person is from you, the time interval between his local noon and yours will increase by 4 minutes. It used to be that every town’s clocks were set according to their local noon and this got very confusing for the railroad system so they got the nation to adopt a more sensible clock scheme called time zones. Each person within a time zone has the same clock time. Each time zone is 15 degrees wide, corresponding to 15 degrees × 4 minutes/degree = 60 minutes = 1 hour worth of time. Those in the next time zone east of you have clocks that are 1 hour ahead of yours. The Pacific timezone is centered on 120° W longitude, the Mountain timezone is centered on 105° W longitude, etc. 3.7.4 Equation of Time There is a further complication in that the actual Sun’s drift against the stars is not uniform. Part of the non-uniformity is due to the fact that on top of the general eastward drift among the stars, the Sun is moving along the ecliptic northward or southward with respect to the celestial equator. Thus, during some periods the Sun appears to move eastward faster than during others. Apparent solar time is based on the component of the Sun’s motion parallel to the celestial equator. This effect alone would account for as much as 9 minutes difference between the actual Sun and a fictional mean Sun moving uniformly along the celestial equator. \|Another effect to consider is that the Earth’s orbit is elliptical so when the Earth is at its closest point to the Sun (at perihelion), it moves quickest. When at its farthest point from the Sun (at aphelion), the Earth moves slowest. Remember that a solar day is the time between meridian passages of the Sun. At perihelion the Earth is moving rapidly so the Sun appears to move quicker eastward than at other times of the year. The Earth has to rotate through a greater angle to get the Sun back to local noon. This effect alone accounts for up to 10 minutes difference between the actual Sun and the mean Sun.\| However, the maximum and minimum of these two effects do not coincide so the combination of the two (called the Equation of Time) is a complicated relation shown in the figure below. The Equation of Time explains why, according to your clock, the earliest sunset and latest sunrise is not at the winter solstice. Yet, the shortest day is at the winter solstice. Rather than resetting our clocks every day to this variable Sun, our clocks are based on a uniformly moving Sun (the mean Sun) that moves along the celestial equator at a rate of 360 degrees/365.2564 per day. Aren’t you glad that your watch keeps track of time for you? The seasonal temperature depends on the amount of heat received from the Sun in a given time. To hold the temperature constant, there must be a balance between the amount of heat gained and the amount radiated to space. If more heat is received than is lost, your location gets warmer; if more heat is lost than is gained, your location gets cooler. What causes the amount of energy reaching a given location during the day to change throughout the year? Two popular theories are often stated to explain the temperature differences of the seasons: 1) the different distances the Earth is from the Sun in its elliptical orbit (at perihelion the Earth is 147.1 million kilometers from the Sun and at aphelion the Earth is 152.1 million kilometers from the Sun); and 2) the tilt of the Earth’s axis with respect to its orbital plane. If the first theory were true, then both the north and south hemispheres should experience the same seasons at the same time. They do not. Using the scientific method discussed in chapters 1 and 2, you can reject the distance theory. A popular variation of the distance theory says that the part of the Earth tilted toward the Sun should be hotter than the part tilted away from the Sun because of the differences in distances. If you continue along with this line of reasoning, then you conclude that the night side of the Earth is colder than the daylight side because the night side is farther away from the Sun. This ignores the more straightforward reason that the night side is directed opposite the Sun, so the Sun’s energy does not directly reach it. But let’s examine the tilt-distance model a little more. The 23.5° tilt of the Earth means that the north pole is about 5080 kilometers closer than the south pole toward the end of June. This is much, much smaller than the 152 million kilometer distance between the Sun and the Earth’s center at that time. The amount of energy received decreases with the square of the distance. If you calculate (152,000,000 + 5080)2/(152,000,000 – 5080)2, you will find that the north pole would get slightly over 1/100th of one percent more energy than the south pole. This is much too small a difference to explain the large temperature differences! Even if you compare one side of the Earth with the opposite side, so you use the Earth’s diameter in place of the 5080 kilometers in the calculation above, you get 3/100th of one percent difference in energy received. Clearly, distance is not the reason for the large temperature differences. Notice that I used the aphelion value for the distance between the Earth and Sun. That is because the Earth is near aphelion during the northern hemisphere’s summer! This is known by measuring the apparent size of the Sun. You can safely assume that the Sun’s actual size does not vary with a period that depends on the orbital period of a planet thousands of times smaller than it, or that it would choose the Earth’s orbital period as its pulsation cycle. Earth reaches perihelion in the first week of January (during the north hemisphere’s winter!) and aphelion in the first week of July (during the north hemisphere’s summer!). The distance theory predicts the opposite seasons from what’s observed in the north hemisphere. Precise dates and times for the perihelion and aphelion events can be found at the US Naval Observatory’s Applications Department’s Earth’s Seasons page (link will appear in a new window; make the appropriate time adjustment for your time zone.) Even though the distance model (in any variation) is incorrect, it is still a “good” scientific theory in that it makes testable predictions of how the temperature should change throughout the year and by how much. However, what annoys scientists, particularly astronomy professors, is ignoring those predictions and the big conflicts between predictions and what is observed. Let’s take a look at a model that correctly predicts what is observed. The tilt theory correctly explains the seasons but the reason is a little more subtle than the distance theory’s explanation. Because the Earth’s rotation axis is tilted, the north hemisphere will be pointed toward the Sun and will experience summer while the south hemisphere will be pointed away from the Sun and will experience winter. During the summer the sunlight strikes the ground more directly (closer to perpendicular), concentrating the Sun’s energy. This concentrated energy is able to heat the surface more quickly than during the winter time when the Sun’s rays hit the ground at more glancing angles, spreading out the energy. Also, during the summer the Sun is above the horizon for a longer time so its energy has more time to heat things up than during the winter. The Seasons module of the University of Nebraska-Lincoln’s Astronomy Education program enables you to understand these concepts by manipulating such things as the position of the Earth in its orbit and your position on the Earth (link will appear in a new window—choose the third part of the module). You can switch between an earth-centered view showing the Earth at the center of the celestial sphere with the Sun traveling along the ecliptic and a Sun-centered view showing the Earth moving around the Sun. Both views show how the amount of daylight and the angle of sunlight upon the ground change with the passing days and the location on the Earth. The rotational axes of most of the other planets of the solar system are also tilted with respect to their orbital planes so they undergo seasonal changes in their temperatures too. The planets Mercury, Jupiter, and Venus have very small tilts (3° or less) so the varying distance they are from the Sun may play more of a role in any seasonal temperature variations. However, of these three, only Mercury has significant differences between perihelion and aphelion. Its extremely thin atmosphere is not able to retain any of the Sun’s energy. Jupiter’s and Venus’ orbits are very nearly circular and their atmospheres are very thick, so their temperature variations are near zero. Mars, Saturn, and Neptune have tilts that are similar to the Earth’s, but Saturn and Neptune have near zero temperature variation because of their very thick atmospheres and nearly circular orbits. Mars has large temperature changes because of its very thin atmosphere and its more eccentric orbit places its southern hemisphere closest to the Sun during its summer and farthest from the Sun during its winter. Mars’ northern hemisphere has milder seasonal variation than its southern hemisphere because of this arrangement. Since planets move slowest in their orbits when they are furthest from the Sun, Mars’ southern hemisphere has short, hot summers and long, cold winters. Uranus’ seasons should be the most unusual because it orbits the Sun on its side—its axis is tilted by 98 degrees! For half of the Uranian year, one hemisphere is in sunlight and the other is in the dark. For the other half of the Uranian year, the situation is reversed. The thick atmosphere of Uranus distributes the solar energy from one hemisphere to the other effectively, so the seasonal temperature changes are near zero. Pluto’s axis is also tilted by a large amount (122.5 degrees), its orbit is the most elliptical of the planets, and it has an extremely thin atmosphere. But it is always so far from the Sun that it is perpetually in deep freeze (only 50 degrees above absolute zero!). - Equation of Time - mean Sun - time zone Review Questions 7 - How many minutes difference is there between local noon in Seattle, WA and somebody’s local noon 3 degrees longitude east of Seattle? Will their local noon occur before or after Seattle’s? - The Eastern Standard Time zone is 3 hours ahead of the Pacific Standard Time zone. The Pacific timezone meridian is at 120° W longitude. What is the longitude of the Eastern Time zone meridian? - Is the Sun’s drift eastward greater at the solstices or the equinoxes? Why is that? - Is the solar day longer at perihelion or aphelion? Why is that? - What causes the temperature differences between the seasons? How so? - If you shine a flashlight on a flat tabletop, which gives you a smaller concentrated beam: one directed perpendicular to the tabletop or one directed parallel to the tabletop? Which one produces the longer shadow of a pencil on the tabletop? - How would the fact that the Sun’s angular size is largest around January 4 contradict the popular theory that the Earth’s distance from the Sun in its elliptical orbit causes the seasons? 3.8 Motions of the Moon The Moon moves rapidly with respect to the background stars. It moves about 13 degrees (26 times its apparent diameter) in 24 hours—slightly greater than its own diameter in one hour! The image below illustrates this rapid motion as well as the fact that you can see the Moon during the day. (Select the image to bring up an enlarged version.) Closer inspection of the image shows that the first image is a waning gibbous phase one day past full phase and the sequence progresses toward less of the visible part of the Moon being visible as the Moon moves closer to the Sun as seen from the Earth. Among other things, this section will explain why these images had to taken in the early morning and why I had to be facing toward the west-southwestern direction with the Sun more or less behind me. Its rapid motion has given it a unique role in the history of astronomy. For thousands of years it has been used as the basis of calendars. Isaac Newton got crucial information from the Moon’s motion around the Earth for his law of gravity. If you watch the Moon throughout the year, you will see the same face of the Moon all of the time. It is the “man in the moon”, “woman in the moon”, “rabbit in the moon” etc. One thing this shows you is that the Moon turns exactly once on its axis each time that it goes around the Earth. Later on you will find out how tidal forces have caused this face-to-face dance of the Earth and Moon. The Moon drifts eastward with respect to the background stars (or it lags behind the stars). It returns to the same position with respect to the background stars every 27.323 days. This is its sidereal period. - sidereal period Review Questions 8 - How does the Moon move with respect to the stars? - How does the fact that we always see one side of the Moon prove that the Moon rotates once every orbital period? - In a particular year the Moon is in the constellation Aries on June 1st. What date will it be in Aries the next time? - Why did the Apollo missions to the Moon always have landings on the same side of the Moon? (Requires some thought and/or research.) 3.8.1 Phases and Eclipses One of the most familiar things about the Moon is that it goes through phases from new (all shadow) to first quarter (1/2 appears to be in shadow) to full (all lit up) to third quarter (opposite to the first quarter) and back to new. This cycle takes about 29.53 days. This time period is known as the Moon’s synodic period. Because the Moon moves through its phases in about four weeks, the phases of new moon, first quarter, full moon, third quarter occur nearly one week apart from each other. Select this link to find the phase for any date and time between 1800–2199 (will display in another window). A picture of the Moon will be shown. The phases are due to how the Sun illuminates the Moon and the relative positioning of the Earth, Moon, and Sun. The figure below shows that as the Moon orbits the Earth, the fraction of its illuminated side that you can see from the Earth changes. From high above the Earth and Moon orbit, you can see that the Moon is always half lit by the Sun and the lit half (the illuminated side, or day side) always faces the light source—the Sun. The other half (night side) faces away from the Sun. The figure below combines two view points. The half-lit moon on the inner circle around the Earth is the Moon as viewed from high above the Earth and Moon orbit. The outer ring of Moon pictures in various phases is the view of the Moon as we would see it from the Earth. Of course, this drawing is not to scale. Select here for a nice simulation of the Moon phases (will display in another window). Be sure to choose “both” in the point of view pop-up list. You will observe only a small fraction of the Moon’s illuminated side when it is close to the Sun. In fact, the smaller the angular distance between the Moon and the Sun, the less of its illuminated side you see. When the angular distance is less than 90° separation, you on the Earth will see less than half of the Moon’s illuminated (day) side and it will look like a a curved sliver of light—the crescent phase. You will see mostly the night side of the Moon. Because the Moon is spherical, the boundary between light and shadow (night) is curved. Note that the figure of the phase angles above shows just one of the angles possible for the crescent phase (at 45°). When the angle between Sun and Moon is within about 6 degrees you on the Earth see it in a new phase and it is the beginning of the phase cycle. Sometimes that angle = 0 degrees and you have a solar eclipse—the moon is in new phase and it is covering up the Sun. The Earth’s shadow always points directly away from the Sun (and it tapers down to a point). At new phase the Moon is in the same direction as the Sun as seen from the Earth, so the Earth’s shadow cannot be why you just see the night side of the Moon. The sequence of pictures below shows a technique you can use to figure out how a Moon phase will look from the Earth when you start from an “orrery” or space view of the Moon, i.e., how to translate from the orrery (space) view of the Moon in its orbit around the Earth to the ground-based view. To show the technique, let’s use the Waxing Crescent example. At 90° angular separation from the Sun, you on the Earth see half of the Moon’s illuminated (day) side and half of its night side. The phase is called a quarter phase because you can see a quarter of the Moon’s entire surface (and 90 degrees is one-quarter of 360 degrees). The quarter phase a week after the new phase is called first quarter. The greater the angular distance is between the Moon and the Sun, the more of the Moon’s illuminated side you can see from the Earth. When the angular distance between Sun and Moon is more than 90° separation, you on the Earth will see more than half of the Moon’s illuminated (day) side—the gibbous phase. You will see a small amount of the Moon’s night side. “Gibbous” means a shape that is convex (bulges outward) at both sides. Again note that the figure shows just one of the angles possible for the gibbous phase (at 135°). Also, note again that the Moon is always half lit up by the Sun. How much of the lit side (day side) we see from the Earth depends on where the Moon is in its orbit around the Earth. Around 180° angular separation from the Sun, you on the Earth see the entire illuminated (day) side of the Moon—the full phase. Sometimes (about twice a year) the Sun-Moon angle is exactly 180 degrees and you see the Earth’s shadow covering the Moon—a lunar eclipse. Sometimes a descriptive term is added to the crescent and gibbous phases. If the amount of illuminated side you can see increases with time, it is waxing as in waxing crescent or waxing gibbous. The daylit side of the Moon will be facing toward the west (toward the right for observers in the northern hemisphere and toward the left for southern hemisphere observers). If the illuminated fraction decreases with time, it is waning as in waning crescent or waning gibbous. The daylit side of the Moon will be facing toward the east (toward the left for observers in the northern hemisphere). Readers in the southern hemisphere need to reverse “left” and “right” in the figure below. Let’s do one last example of translating from the orrery (space) view of the Moon’s position in its orbit to the Earth (ground) view with the Moon in a Waning Gibbous position. Here are the sequence of steps in the figure below. You can use the illustration of the lunar phases at the top to find out the time of day when the Moon will be visible. The Sun is at the right of the figure so a person at position (A) on the Earth (e.g., Los Angeles, CA) sees the Sun on the meridian. When an object is on the meridian, your part of the Earth is pointing directly toward that object. The Earth rotates in the counterclockwise direction (A to B to C to D). A person at position (B) (e.g., Sao Mateus in the Azores) sees the Sun setting since he is one-quarter turn (6 hours) ahead of the person at position (A). The person at position (C) (e.g., Zahedan, Iran) is at the midnight position (half a turn, 12 hours, ahead of position (A)) and the person at position (D) (e.g., Sydney, Australia) is experiencing sunrise (three-quarters of a turn, 18 hours, ahead of position (A)). If the Moon was at its new phase position, person (D) would see the new moon rising, person (A) would see the new moon on the meridian, and person (B) would see the new moon setting within a few minutes of sunset. If the Moon was at its first quarter position, person (A) would see the Moon beginning to rise, person (B) would see the Moon on his meridian at sunset, and person (C) would the first quarter moon setting because it is already midnight at her position. The figure below illustrates these views. Using the same method, you can see that the full moon is rising for person (B) at sunset, is on the meridian at midnight for person (C) opposite the Sun, and is setting for the person (D) at sunrise. Now try to figure out when the third quarter moon will rise, cross the meridian, and set using this method. Remember that each of the persons A, B, C, D are each six hours apart from each other. Also, remember person (D) is facing down in the orrery view on the left side of the figure above and if the person is facing south, the Sun will be rising on his left. If you are having a hard time visualizing this, try using a white ball (e.g., a styrofoam ball) for the Moon, a bright light bulb for the Sun, and your head for the Earth in a room shut off from other lights. When your eyes are facing the bulb, that would be noon. While facing the bulb, move the ball to your left ear so half of it is lit up. That is the first quarter phase. If you move your head counterclockwise 90° so you are facing the half-lit ball, you will see the bulb out of the corner of your right eye (in the “west” direction). That would be sunset. Move the ball around so it is opposite the bulb but out of the shadow of your head. You should see all of it lit up—a full phase. If you face the same direction that you faced the half-lit ball, the full phase ball would be visible out of the corner of your left eye (in the “east” direction). As you turn your head counterclockwise, you will see the ball “rise” and the bulb “set”. When you face the full-lit ball, that would be midnight. How would you simulate a third quarter phase? The table gives a summary of approximately when the Moon is visible and where to look (the crescent and gibbous phases are in between the table values). You may be surprised to find out that the Moon is sometimes visible in broad daylight! \|Phase\|\|Time the Moon is ahead/behind the Sun \|Moon Crosses Meridian \|New\|\|within few minutes\|\|Sunrise\|\|Noon\|\|Sunset\| \|First Quarter\|\|6 hrs behind\|\|Noon\|\|Sunset\|\|Midnight\| \|Full\|\|12 hrs behind\|\|Sunset\|\|Midnight\|\|Sunrise\| \|Third Quarter\|\|6 hrs ahead\|\|Midnight\|\|Sunrise\|\|Noon\| The phase diagram seems to show that a solar and lunar eclipse should happen every month but eclipses actually happen only twice a year. You can see why if you look at the Moon’s orbit from close to edge-on. The Moon’s orbit is tilted by 5 degrees with respect to the Earth’s orbital plane (the ecliptic). In order for an eclipse to occur, the Moon must be in the ecliptic plane AND exactly at the new or full phase. Usually, the Moon crosses the ecliptic plane at another phase instead of exactly at new or full phase during its approximately month-long orbit around the Earth. During a year the Moon’s orbit is oriented in very nearly the same direction in space. The position of the Earth and Moon with respect to the Sun changes while the Moon’s orbit direction is approximately fixed. So in one month the Moon will be below the ecliptic at full phase and above the ecliptic at full phase about six months later. Though the Moon crosses the ecliptic twice a month, an eclipse will happen only when it is exactly at full or new phase when it crosses the ecliptic. The tilt of the Moon’s orbit explains why eclipses happen only twice a year. The direction of the Moon’s orbit slowly shifts (precesses) over time. Because the Moon’s orbit precesses, eclipses will occur on different dates in successive years. However, even if there was no precession, eclipses would still happen only twice a year. The figure above shows another complication—the elliptical orbit of the Moon around the Earth means that the new moon can occur at different distances from the Earth and the Moon’s shadow may not reach the Earth if it is too far away. Why are the synodic and sidereal periods not equal to each other? For a reason similar to the reason why the solar day and sidereal day are not the same. Remember that a solar day was slightly longer than a sidereal day because of the Sun’s apparent motion around the Earth (which is really due to the Earth’s motion around the Sun). The Sun’s eastward drift against the stars also means that the Moon’s synodic period is longer than its sidereal period. At new moon, the Sun and Moon are seen from the Earth against the same background stars. One sidereal period later, the Moon has returned to the same place in its orbit and to the same place among the stars, but in the meantime, the Sun has been moving eastward, so the Moon has not yet caught up to the Sun. The Moon must travel a little over two more days to reach the Sun and establish the new moon geometry again. The modern model has the Moon going around the Earth with the Sun far away. At different positions in its orbit you see different phases all depending on the relative positions of the Earth-Moon-Sun. Another possible model was presented by highly-esteemed Harvard seniors at their graduation. They seriously proposed that the dark part of the Moon is the result of portions of the Moon lying in the shadow of the Earth. Many other people have also explained the phases with this Earth shadow model, but I will call this the “Harvard model” below. Since the Moon would need to be opposite the Sun for it to be in the Earth’s shadow, the “Harvard model” predicts Sun-Moon angles that are very different from the observed angles. In addition, the model predicts that the Moon would need to be one-half a rotation (or 12 hours) away from the Sun. The Moon should rise 12 hours after sunrise (i.e., at sunset), cross the meridian 12 hours after the Sun, and set 12 hours after sunset (i.e., at sunrise) for all of the phases except full. How is this different from what is observed? Test and improve your understanding of the lunar phases with the UNL Astronomy Education program’s Lunar Phase Simulator. A space view from high above the Earth showing the Moon’s orbit and the on Earth view are used to show how the Sun-Moon geometry gives rise to the phases (and how the Earth’s shadow cannot!). - lunar eclipse - solar eclipse - synodic period Review Questions 9 - Why does the Moon have phases? - Why are New Moon phases longer than a sidereal period (27.3 days) apart from each other? - If the Moon was full 7 nights ago, what time of day (night) should you look for the Moon to be up high in the sky in the south today? Explain your answer. - What are the positions of the Earth-Moon-Sun during an eclipse? - What would the Sun-Moon angular separation be for the New Moon if the Earth’s shadow caused the lunar phases? How about Gibbous phase? - What are the real angular separations for New and Gibbous phase? - About how much difference in time is there between moonset and sunset at first quarter phase? Does the Moon set before or after the Sun at that phase? - About how much difference in time is there between moonset and sunset at new phase? - If the Earth’s shadow caused the lunar phases, what would be the difference in time between moonrise and sunrise at new and first quarter phases? - About when will the Waxing Crescent Moon be on the meridian? Explain your answer. - The Moon is low in the western sky at sunrise, what is its phase? Explain! - Why do we not have eclipses every month? 3.8.2 Eclipse Details: Lunar Eclipse Let’s explore a little more about lunar and solar eclipses. Remember that an eclipse happens when an object passes through another object’s shadow. Any shadow consists of two parts: an umbra, which is the region of total shadow, and the penumbra, which is the outer region of partial shadow. If the Moon were to pass through the Earth’s umbra, an observer on the Moon would not be able to see the Sun at all—she would observe a solar eclipse! An observer on the Earth looking at the Moon would see a total lunar eclipse. The Earth’s shadow is pretty big compared to the Moon so a total lunar eclipse can last up to about 1 hour 45 minutes. If the Moon only passed through the outer part of the shadow (the penumbra), then the observer on the Moon would see the Sun only partially covered up—a partial solar eclipse. The observer on the Earth would see the Moon only partially dimmed—a partial lunar eclipse. Below is a sequence of images from the August 28, 2007 lunar eclipse as observed from Honolulu, Hawaii. The images were taken every five minutes through a telescope. The dark red-orange color is the color you would see if you observed the eclipse. During a total lunar eclipse you see another interesting effect—the Moon turns a coppery (or bloody) red. The reason why some sunlight reaches the Moon despite the fact that the Moon is in the Earth’s umbra is that the sunlight refracts or bends as it passes through the Earth’s atmosphere. Dust particles in the Earth’s atmosphere remove much of the bluer colors in the sunlight so only the redder colors make it to the Moon. The amount of dust determines the deepness of the red colors. The dust in the air is also why the Sun appears redder at sunset on Earth. The observer on the Moon would see a reddish ring around the Earth even at mid-eclipse! Some nice visualizations of the lunar eclipse essentials are available at Goddard Space Flight Center’s Lunar Eclipse Essentials page. The Moon’s shadow also has an umbra and penumbra, but its shadow is much smaller than the Earth’s. Only if the Moon is in the ecliptic plane when it is exactly New Moon will the Moon’s shadow hit the Earth. Where the umbra hits the Earth, you will see a total solar eclipse. Where the penumbra hits the Earth, you will see a partial solar eclipse. Select the image to get information about this image of the July 11, 1991 solar eclipse taken by Fred Espenak (will display in another window). In a total solar eclipse the bright disk of the Sun is completely covered up by the Moon and you can see the other parts of the Sun like the corona, chromosphere, and prominences. Unfortunately, only the tip of the Moon’s umbra reaches the Earth (the tip hitting the Earth is at most 270 kilometers [168 miles] in diameter) and it zips along the Earth’s surface at over 1600 kph (1000 mph) as the Moon moves around the rotating Earth. This means that a total solar eclipse can last a maximum of only 7.5 minutes. Usually total solar eclipses last only 2-3 minutes. Because of the orbital motion of the Moon and the rotation of the Earth, the umbra makes a long, narrow path of totality. Sometimes the umbra does not reach the Earth at all (only the penumbra) even though the Moon is on the ecliptic and it is exactly in New Moon phase. A bright ring will be visible around the Moon when it is lined up with the Sun—an annular eclipse (because of the annulus or ring of light around the Moon). What do you think this implies about the shape of the Moon’s orbit? The sequence below is of the May 20, 2012 annular solar eclipse as seen from Red Bluff, CA. Select the image to go to a full-size image of the eclipse sequence and an animation. A video of the central 5 minutes of the total solar eclipse of November 13, 2012 as seen from Amaroo, outside of Cairns, Australia, is posted on YouTube. The video also shows that even astronomers have to contend with the weather. The sequence below is of the May 20, 2012 annular solar eclipse as seen from Red Bluff, CA. Select the image to go to a full-size image of the eclipse sequence and an animation. Eclipse Web Sites The following sites are probably the best and most complete ones on the web. You’ll find eclipse predictions, photographs, observing instructions, and fairly complete indexes of all high-quality eclipse sites on the web. Between these three you should find whatever you may be interested in with regard to eclipses. They will display in another window. - NASA’s Eclipse Bulletins. - Fred Espenak’s eclipse site. A less technical version of the NASA site. Fred Espenak is also the main contributer to the NASA site. - Sky & Telescope‘s eclipse site. - annular eclipse Review Questions 10 - What are the two parts of a shadow and in which part is the Sun partially visible? - Why does the Moon turn orange-red during a total lunar eclipse? - Would a person on the Moon ever experience an annular solar eclipse? Explain your answer. - Why do we not have just annular solar eclipses or just total solar eclipses when the Moon and Sun are exactly lined up? 3.9 Planetary Motions There are other celestial objects that drift eastward with respect to the stars. They are the planets (Greek for “wanderers”). There is much to be learned from observing the planetary motions with just the naked eye (i.e., no telescope). There are 5 planets visible without a telescope, Mercury, Venus, Mars, Jupiter, and Saturn (6 if you include Uranus for those with sharp eyes!). All of them move within 7 degrees of the ecliptic. This tells you something about of the orientation of the planet orbit planes with respect to the ecliptic—the figure below shows how flat the solar system is when viewed along the ecliptic plane. The planet positions, of course, do change as they orbit the Sun, but the orbit orientations remain the same. The arrow pointing to Polaris in the solar system picture is tilted by 23.5 degrees because the Earth’s rotation axis is tilted by 23.5 degrees with respect to the ecliptic. As viewed from the Earth, two of the planets (Mercury and Venus) are never far from the Sun. Venus can get about 48 degrees from the Sun, while Mercury can only manage a 27.5 degrees separation from the Sun. This tells you something about the size of their orbits in relation to the Earth’s orbit size—their orbits are smaller and inside the Earth’s orbit. When Venus and/or Mercury are east of the Sun, they will set after sunset so they are called an “evening star” even though they are not stars at all. When either of them is west of the Sun they will rise before sunrise and they are called a “morning star”. Planets produce no visible light of their own; you see them by reflected sunlight. True stars produce their own visible light. The planets inside the Earth’s orbit are called the “inferior” planets because their distance from the Sun is less than (or inferior to) the Earth’s distance from the Sun. Their closeness to the Sun enables us to see them go through a complete set of phases. Because they can get between us and the Sun, Venus and Mercury can be seen in a crescent or new phase. This also explains why the planets outside the Earth’s orbit, called the “superior planets”, are never seen in a crescent or new phase. When Venus is in crescent phase, it is the brightest object in the sky besides the Moon and the Sun. Even though you see a small fraction of its sunlit side, it is so close to us that you see it appear quite bright. At these times, Venus is bright enough to create a shadow! The fact that you can see Venus and Mercury also in gibbous and nearly full phase proved to be a critical observation in deciding between a Earth-centered model and a Sun-centered model for the solar system. Because Mercury and Venus are closer to the Sun than we are (i.e., their orbits are inside the Earth’s orbit), they are never visible at around midnight (or opposite the Sun). The superior planets can be visible at midnight. At midnight you are pointed directly away from the Sun so you see solar system objects above the horizon that are further out from the Sun than we are. If you want to see where the planets are in their orbits today or any other date, then go to the Solar System Live site (will display in another window). Ordinarily the planets “wander” eastward among the stars (though staying close to the ecliptic). But sometimes a strange thing happens—a planet will slow down its eastward drift among the stars, halt, and then back up and head westward for a few weeks or months, then halt and move eastward again. The planet executes a loop against the stars! When a planet is moving backward it is said to be executing retrograde motion. Perhaps it seemed to the ancients that the planets wanted to take another look at the stars they had just passed by. The figure below shows Mars’ retrograde loop happening at the beginning of 1997. Mars’ position is plotted every 7 days from October 22, 1996 (the position on November 12, 1996 is noted) and the positions at the beginning and end of the retrograde loop (February 4 and April 29, 1997) are noted. An animation of this is available here. What causes retrograde motion? The answer to that question involved a long process of cultural evolution, political strife, and paradigm shifts. You will investigate the question when you look at geocentric (Earth-centered) models of the universe and heliocentric (Sun-centered) models of the universe in the next chapter. - retrograde motion Review Questions 11 - How do the planets move with respect to the stars? - What does the fact that all of the planets visible without a telescope move within 7° of the ecliptic imply about the alignment of their orbital planes? What would an edge-on view of our solar system look like? - Why are Venus, and Mercury never seen at midnight while the other planets can be visible then? - What phase would Venus be in when it is almost directly between us and the Sun? Where would it be in its orbit if we see in a gibbous phase? - Are the planet motions random all over the sky or are they restricted in some way?
The heart is the primary organ responsible for oxygen delivery to the tissues. The heart is automatic by nature, because it can receive and pump blood without outside influences. For the heart to function adequately, it requires sufficient levels of various electrolytes, including potassium. Levels of blood potassium vary inversely with heart rate; as the levels of potassium drop below normal, the heart rate increases beyond normal. Blood potassium levels between 4.0 and 4.5 milliequivalents per liter, or mEq/L, are considered normal; blood potassium levels below 4.0 mEq/L are considered low. According to a 2010 "Experimental & Clinical Cardiology" article, in people with heart attacks, low blood potassium was associated with an increased likelihood for ventricular tachycardia or rapid beating of lower heart chambers. Also, normal levels of blood potassium was associated with no episodes of heart rhythm abnormalities. The heart rate is a component of the cardiac output or the amount of blood pumped out by the heart each minute. The cardiac output must be adjusted according to oxygen demands; as oxygen demands increase, the cardiac output must be increased to meet up with oxygen demands. Normally, increasing the heart rate is beneficial to the cardiac output, but a too-rapid heart rate compromises the cardiac output. In ventricular tachycardia, the heart rate is too fast, thereby reducing the time needed to fill the heart with blood. The heart can only pump out the blood it receives; as more blood enters the heart, more blood is pumped out. Sources of Potassium Normal potassium levels are maintained by diet intake of potassium and the adjustment of kidneys' excretion of potassium. According to the United States Department of Agriculture, the recommended daily intake of potassium is about 4,700 mg/day. Dietary sources of potassium include baked potatoes, yogurt, tomato paste, white beans and clams. Symptoms of Low Potassium In a person with normal functioning kidneys, low blood potassium may occur as a result of decreased dietary potassium intake or increased excretion of potassium from the kidneys. Severely increased release of aldosterone -- a hormone normally produced by the adrenal glands as a result of increase potassium, causes the increased excretion of potassium from the kidneys. When a person is low in potassium they may experience fatigue, muscle pain, progessive muscle weakness and shortness of breath due to weakening of the respiratory muscles.
Any philosophical discussion about the idea of fairness must first address who is included in the definition of “fair”. Is “fairness” designed only for a sub-sect of the population, or for the population as a whole? Fairness should be defined in such a way as to include all people within the body politic. A discussion of fairness in regards to political philosophy generally recognizes that there are dignities and rights which belong to each and every person. Therefore anything that is done, by the state or by individuals, which is injurious to those dignities or rights is fundamentally unfair. This is a natural rights conception of what fairness means. It is not the only definition of fairness, of course, but it is certainly the most popular. Laws must not only accomplish their desired aims, but they must do so in a way that does not trample upon the basic rights and dignities of all people. If a law aims to accomplish something good, is efficient at accomplishing that aim, but also tramples the rights of a small sub-group of individuals in the process, then it is an unfair law which should be repealed. There are other theories of fairness, of course, including the utilitarian sort. No discussion of “fairness” could possibly be complete until Jeremy Bentham’s paraphrasing of how to define justice and fairness is mentioned, “The greatest good for the greatest number”. What Bentham meant by this is that laws should be created according to what maximizes the happiness and “good” for the most people possible. This is what is called a utilitarian argument, meaning that the maximum utility is what is being sought, rather than a recognition of basic rights which should not, or cannot, be subverted. This is an on-going debate in the realm of philosophy and especially political philosophy. But it ought to be an issue which the average voter considers, too, if only briefly. After all, these theories of fairness, abstract as they may be, do tell us something about how we are being governed. A sense of fairness and balance is essential to politics. After all, much of what political science is about is figuring out what is “fair” in terms of the establishment of laws. Fairness is a virtue that most people learn early on in their lives. They are taught the basic precepts as children and as they mature they come to more fully understand the essential tenets of fairness. It essentially means being free from bias or injustice and it is a virtue that just about everyone attempts to ascribe to. Everyone, that is, except President Barack Obama and his cohorts in Congress. It is a question worth asking, does Presidential Barack Obama understand the principles of fairness? Does he follow the natural rights or utilitarian understanding of fairness? The truth is, he seems to either not understand or fundamentally misunderstand what the term fairness really means, despite his love for trotting the word out in every major address of the American people. President Obama’s identification of what he thinks is “fair” shows us that that he does not have a philosophical underpinning for the word, via utilitarianism or natural rights. Instead, he is simply using the word to stoke the hearts and minds of beleaguered voters who feel wronged. Voters should feel wronged, they have every right to feel that way. But it is important to not only identify the source of unfairness, but to accurately resolve it. Barack Obama does not believe there are certain dignities and rights which cannot be negotiated–thus his targeting of the “rich” and his healthcare system’s demands for purchased insurance. Neither does the President provide Bentham’s “…greatest good for the greatest number.” He cannot be following the utilitarian understanding of justice either, since his policies result not in the greatest good for the greatest number, but rather in the greatest good for a very small number, while the masses suffer from them. So if Obama is not really interested in establishing a more fair set of laws, then why does he use the word so much? The simple answer is obfuscation–he is using the term to his electoral benefit. When he asks the “wealthy” to “pay their fair share”, people should carefully consider what exactly he means by this. Fair is fair–but Obama either does not care what the word means, or does not care to know.
In response to climate change and a warming world plants and animals would naturally shift their distributions northwards to adapt. However many are prevented from doing so because habitats have become fragmented and disconnected, and because of natural barriers such as the English Channel. This project seeks to address this problem by building a robust ecological network on either side of the Channel, and investigating the possibility of helping species move. Concrete actions to protect the natural heritage of the cross-Channel region by restoration operations and environmental management of threatened natural environments ; To launch a debate to consider the potential for the reintroduction of species which have disappeared from Kent using French stock ; To share expertise on ecological management for the conservation of habitats and species ; To improve public understanding of the natural heritage of the cross-Channel region.Several programs have been developed: Events and activities
§ 3.2 Theoretical Transportation Energy The Earth is 81 TIMES as massive as the Moon, and asteroids have a trivial mass compared to the Moon. To get from the surface of the Earth or the Moon into orbit around Earth (where space products providing valuable space services will reside) requires energy in two forms: Notably, when the Space Shuttle goes into low Earth orbit about 500 kilometers up, only about 7% of the theoretical energy required goes into lifting it to that height (potential energy). About 93% of the energy goes into accelerating the Space Shuttle to a speed where it goes into a circular orbit (kinetic energy). The total amount of energy (kinetic plus potential) required is often expressed in terms of an analogy -- an "energy well", as pictured here, as if each gravitational body represented a hole in the ground like a water well which a cargo must crawl out of. The bigger the planet, the deeper the equivalent well. In the picture below, the vertical "height" represents the energy required to move from one point to the other, whereby the horizontal length represents the physical distances (to scale). Note on the graph that the energy required to go into "geostationary earth orbit (GEO)", i.e., "stationary communications satellite orbit", from the Moon is small, compared to coming from Earth. It will later be shown that the energy required to get material from many asteroids near Earth into geosynchronous orbit is even less than from the Moon. The Space Shuttle can goes to about 500 kilometers, and doesn't have the capability to go significantly higher than that, energy-wise. Communications satellite orbit is at 36,000 kilometers. Roughly half the energy to get to geosynchronous orbit is consumed in just getting to an orbital speed. When the Space Shuttle carries a communications satellite up, it brings it only above the atmosphere to the 500 kilometer orbit. From there, the satellite is removed from the cargo bay and then launches to geosynchronous orbit 36,000 kilometers up using its own fuel propellant, which mades up most of the cargo in the Shuttle bay, not the satellite. But this is another issue for another place. What orbital speeds are we talking about? For low Earth orbit, we are looking at a little over 7 kilometers per second (i.e., about 15,000 miles per hour), for the orbital speed. At this speed, the Shuttle orbits the Earth in about one and a half hours. As a satellite goes higher in orbit where Earth's gravity is weaker, it does not need to go as fast to stay in orbit, and thus one orbit of the Earth takes much longer, e.g., 24 hours for GEO. However, it takes much more energy to lift it up to that orbit. An orbit used by communications satellites is a high Earth orbit called "geostationary" or "geosynchronous" orbit, where it takes exactly 24 hours for one orbit. Since the Earth rotates once per 24 hours, each satellite stays "stationary" or "synchronized" above one point on Earth. That's why you can point your satellite TV dish to one place and leave it there, rather than having to track the satellite and lose communication if it were to pass over the horizon. It takes more than 10 times more energy, theoretically, to get into geosynchrous Earth orbit from the surface of the Earth than from the surface of the Moon (that is, a circular orbit). The energy required from asteriods near Earth could be less or more than from the Moon, depending on the particular asteroid's orbital properties. Adding in the heavy vehicle and complexity associated with Earth launch, and launching the fuel for later in the flight, getting materials off of the Moon and especially from asteroids is much easier than from Earth. To escape Earth orbit altogether takes less than 10% more energy than getting to geostationary orbit. Hence, the energy difference between GEO and other bodies besides Earth is often much less. (One item often quoted by others it that it takes about 22 times more energy to launch from Earth and "escape" to infinity (without going into orbit) than to likewise launch from the Moon and escape to infinity. That is a simple comparison for laymen to illustrate the point, and differs somewhat from the more detailed comparison given here which accounts for getting into various useful circular orbits.) It's important to understand that it takes just as much energy to come down as it does to go up -- there's no "free downhill". Coming "downhill" takes just as much energy and fuel in space because there is no friction -- you must spend fuel to lower yourself into a circular orbit. (An exception could be "aerobraking", i.e., using the Earth's atmosphere for friction, but no such vehicle has been operated to date except for return to Earth's surface. Aerobraking is discussed in the vehicles section.) Without aerobraking, if you simply brake and fall down in an elliptical orbit, you'll soon be right back at the top of that elliptical orbit and ready for another cycle. To stay at the bottom of the orbit requires that you circularize your orbit when you arrive there by spending more fuel. Higher orbits have more potential energy but less kinetic energy. In fact, mathematically, to move from a lower orbit to a higher orbit requires spending two parts potential energy for every one part kinetic energy reduced. Notably, there's no energy shortcut -- if you skip going into an interim orbit but just shoot from the surface of the Earth to a high orbit, you don't save anything, theoretically. However, in practical terms, there are differences between trajectories to get into a circular high orbit so that you can spend significantly more than the theoretical minimum. In general, haste makes waste, in terms of energy and fuel spent. The theoretically best trajectory from Earth's surface to any Earth orbit is to first get into orbital space, so that one isn't fighting against gravity's pull back down, and then to spiral up slowly, thrusting perpendicular to the line of sight with Earth (i.e., adding purely centrifugal force). However, this is rarely followed due to economic factors other than fuel launched (e.g., time and complexity, and radiation belt damage factors). On the graph: "Sea Level Earth Orbit (SLEO)" just illustrates the minimum energy required to "stay in outer space" rather than standing (or crashing back) on Earth's surface -- Sea Level Earth Orbit is, say, a purely theoretical orbit just one foot above sea level as if there were no atmosphere or hills to crash into. Energy-wise, Sea Level Orbit represents the 93% kinetic energy to get to Shuttle orbit from Earth's surface, as compared to the 7% to lift up above the atmosphere. The Moon also has a "sea level orbit", or since it has "Mares" instead of "Seas", it has a corresponding "Mare Level Orbit". The entire graph represents the theoretical minimum amount of energy required. However, the more energy required, the more fuel must be lifted for use later. Thus, the rocket size and complexity increase well out of proportion to the theoretical minimum energy required. Asteroids have no significant escape velocity or "sea level orbital energy", and can be seen as objects already in orbital space. On the chart, they would be located beyond the dashed line above high Earth orbit, energy-wise. Some near Earth asteroids are just a tiny bit above the the dashed line, though most asteroids are significantly above the line. However, an analysis of retrieving asteroidal materials does not lend itself well to the above analysis, largely due to a concept called a "lunar gravity assist", which saves energy by trading orbital energy with the Moon, as discussed below.
\|Ice Ages\|\|ISM Home > Exhibits > Ice Ages>\| The term is used to describe time intervals on two very different scales. It describes long, generally cool intervals of Earth history (tens to hundreds of millions of years) during which glaciers advanced and receded. The term also describes shorter time periods (tens of thousands of years) during which glaciers were near their maximum extent. These shorter intervals are also known as "glaciations." In addition, the term "Ice Age" is sometimes used to refer to the last major glaciation that occurred in North America and Eurasia. When used in this way, the first letters of both words are often capitalized. This is the way the term Ice Age is used in the Midwestern U.S. 16,000 Years Ago exhibit. \|Illinois State Museum\|\|State of Illinois\|\|IDNR\|\|Search\|
Baking Beautiful Brownies - poster with the words to the tongue tickler - primary paper for each student - pencil for each student - Big Brown Bear's Up and Down Day by David McPhail 1. Today we are going to learn about the letter b. Does anyone know what sound the letter b makes? Buh-buh, is right! When we say the /b/ sound our lips start together and when they open a puff of air comes out. Everyone try it with me, buh-buh. Sounds great! 2. Who can tell me something that makes the /b/ sound? I know something that everyone should be familiar with. It goes up and down when a person dribbles it. That's right a basketball! Using basketball demonstrate the dribbling motion, saying the /b/ sound every time it hits the ground. Now everyone pretend like they are dribbling their own basketball, buh-buh. 3. I have a tongue tickler for you to try. Showing poster and pointing to words as you say them say "Bossy Bobby brings baby baked brownies." Everyone repeat it after me now. Now try saying it three times in a row. This time I want everyone to say it together, but say the buh-buh like a dribbling basketball when the b is at the beginning of a word and make the dribbling motion at the same time. Now let's break the /b/ sound off of each word, repeat after me. "/B/ossy /B/obby /b/rings /b/aby /b/aked /b/rownies. Great job! 4. Now everyone grab your primary paper and your pencil. We are going to practice writing the letter b. I will demonstrate on the board as I describe what I am doing. Start at the rooftop and drop all the way to the sidewalk. Now curve around like a circle up to the fence and close the circle back around to the sidewalk. Everyone try writing nine more on your own. This is the letter b that makes the /b/ sound. 5. Now let's try listening for the /b/ sound in words. Watch my mouth and listen for the dribbling basketball sound when I say "bunny". "Buh-buh-bunny". Did you hear the sound? 6. When I point to you I am going to ask you if you a question. Pick out students randomly to answer the questions: Do you hear /b/ in bike or swim? Bounce or jump? Apple or banana? Bear or tiger? 7. I will read Big Brown Bear's Up and Down Day and ask the students to make the dribbling basketball movement every time they hear the /b/ sound. Can everyone show me their best dribbling basketball? Looks great, now when I'm reading and you hear the /b/ sound, I want you to dribble that basketball. 8. For the assessment I will give each child a "Where is the Sound" worksheet with a list of pictures with two words to choose from for each picture. The students must choose which word the picture is of and then write the word on the line next to it. For example, a picture of a bed has the option for bat or cab. The student must circle the word bat for the picture and then write the word bat on the line. Big Brown Bear's Down Day by David McPhail Return to the Projects index
Earth, along with the rest of the planets in our solar system, formed 4.6 billion years ago as material gravitationally clumped together around the young sun. Earth, along with the rest of the planets in our solar system, formed 4.6 billion years ago as material gravitationally clumped together around the young sun. Not all of that material was used up to make planets; some remained as asteroids. Around 4 billion years ago, a realignment of the planets, especially the gravitational pull of massive Jupiter, began flinging asteroids toward the inner planets. This resulted in what is known as the Late Heavy Bombardment, an event well represented by many of the craters on the moon. Earth, being a much larger target and having greater gravitational attraction, must have been hit by even more of these projectiles than the moon, yet evidence for that is lacking. Weathering, erosion and the constant recycling of ocean crust because of plate tectonics have erased all traces of the tremendous impacts that occurred at that time. About 180 impact craters are known on Earth, but all postdate the Late Heavy Bombardment. Researchers recently have reported finding evidence of one of those ancient impacts. It occurred 2.9 billion years ago, making it the oldest impact known on our planet. The crater is in southern Greenland and is called the Maniitsoq structure after a nearby town. It was originally at least 185 miles across and might have exceeded 375 miles. That would make it the largest known impact crater.The portion now exposed at the surface once was covered by 15 miles of solid rock, all since removed by erosion during the 3 billion years since it formed. That erosion also destroyed most of the evidence of an impact, making its discovery all the more remarkable. The authors of the new study, which appeared in the journal Earth and Planetary Science Letters, cite 15 features they say indicate an impact had occurred. Among them are a 125-mile-wide elliptical magnetic disturbance, intense fracturing with random orientation, areas of rock that look as if they had melted quickly, sheets of crushed rock, a central area of thoroughly pulverized rock and sets of parallel microscopic lines in grains of quartz and feldspar. The asteroid that hit is estimated to have been 18 miles in diameter, dwarfing the 6-mile-wide one that has been blamed for causing the extinction of the dinosaurs 65 million years ago. If such an impact occurred today, it would wipe out all higher forms of life on our planet. The ancient impact is not just of academic interest. The greatest concentration on Earth of nickel, a metal used extensively in everything from magnets and microphones to rechargeable batteries and stainless steel, is in Sudbury, Ontario. That is the site of a younger, 2-billion-year-old impact that created the ore that has been mined there since 1901. Mining companies already have shown intense interest in the Maniitsoq structure. Dale Gnidovec is curator of the Orton Geological Museum at Ohio State University.
FYS 101 Is Voting Enough? Worldwide Elections & Democracy We often think of democracy as established when a country’s first free election is celebrated, as it was in Afghanistan, in South Africa, and across Eastern Europe, among many other places. But the story does not end there: questionable election procedures or disputed outcomes have prompted questions about the fairness of elections in places like Ohio in 2004, Mexico in 2006, and Egypt in 2010. Meanwhile, countries such as Russia and Zimbabwe hold elections but seem to lack other democratic institutions and rights. Given this variety, how are elections related to democratic rule? The course will explore this question from several angles. We will compare different definitions of democracy. We will ask, who gets to vote and what restrictions exist on doing so, both in the US and globally? Why do some places become democratic and others struggle to do so? Are flawed elections better than no elections? What are the effects of disputed elections on citizens’ perceptions of their government? What happens if undemocratic forces win elections? Should US foreign policy include encouraging democracy elsewhere?
There are a lot of misconceptions about the scientific method that scientists have to go through in order to conduct an experiment. Contrary to popular belief there is a lot of creativity and thought that goes into the construction of each experiment. There is a general outline that most scientists follow in order to make sure all experiments have the necessary parts and will effectively showcase the information in a translatable way. However, every experiment is special in what it is trying to discover, test, or prove so every experiment must be designed differently because it is testing something different. Because of this every experiment must be carefully and creatively crafted in order to be effectively executed. The scientific method is an outline for a scientist's to follow to help them construct an effective experiment. All experiments will start by asking a question, and that is the first step to the scientific method; ask a question. This is important because unanswered questions are the locomotive of science, it is what pushes us to discover and experiment. Once a question has been asked it is important to do background research on the question being ask. This is because in order to craft a hypothesis for the experiment there must be some knowledge to base the hypothesis on. Through a hypothesis a scientist can explain what they expect to find when conducting the experiment, the nice part is that not matter the outcome of the experiment it does not matter whether the hypothesis was correct or not. This is why two scientists working on the same experiment together can hypothesize two different outcomes. It is often more interesting when the hypothesis is wrong because that is what leads scientists to ask more questions like; Why did I get this result? This is the beginning steps to constructing an experiment which is crucial even though the actual experiment has not even started. It takes critical thinking to come up with a question to answer especially one that has not already been done, and quite difficult to form a hypothesis for the question when in reality the scientist most likely is not sure what is going to happen. The next portion of the scientific method is where the real fun and creativity comes into play. Designing an experiment that will actually achieve what you are trying to test for can be quite tricky, especially if you are not positive of the outcome. Every experiment is different and there are multiple ways to run an experiment and achieve the same result. This is why scientist are allowed to get creative and think outside the box. Harvard recently conducted an experiment about the E. Coli virus on a huge scale. They constructed a mega petri dish and observed the bacteria E. Coli’s ability to become drug resistant and reproduce on a massive scale. They made a time-lapse of the bacteria’s growth and it was quite incredible to see. This is just one example of a scientific experiment that had already been conducted by someone but Harvard scientists took it a step further and conducted an experiment of their own that was so incredible to see. Another big topic in the science community is CRISPR. CRISPR has been the basis of multiple experiments around the World because of its ability to make specific changes to DNA. There have been experiments conducted where human organs can be grown in an animal and can grow to the point of being able to be transplanted into humans. The first human trials with CRISPR started in late October of 2016. The first ever genetically modified cells were injected into a patient with aggressive Lung Cancer. Many experiments were conducted on CRISPR to test its ability to modify DNA and make sure it truly was effective before clinical trials could begin. These are just two examples of truly incredible experiments that are driving the science community forward and require a great deal of creativity and critical thinking. Following the conclusion of the experiment conducted, the most important part of the scientific method comes into play. The scientist must analyze the data that was collected and draw conclusions. This is critical to a scientific experiment because the whole point of running an experiment is to come to a conclusion and share it with other so it can either answer their questions or even prompt them to draw up more questions based on the results. If oncologist Lu You from Sichuan University in Chengdu had not shared his findings on CRISPR, then he may not be conducting clinical trials right now. It was with the help of other scientists and the scientific community that he was able to move forward with his findings so quickly. Although many people believe the scientific method makes science a boring robot like job, this is not the case at all. The scientific method is just an outline that helps scientists present their findings in a neat, easily shared manner. Scientists are constantly pushing boundaries and finding revolutionary results that constantly change our lives.Never following the same procedure but thinking outside the box to better understand and interpret data. If CRISPR clinical trials achieve what is expected of them this could be a very different world in a few years. But that is the beauty of science, you never quite know what you are going to get. Baker, Monya. "1,500 Scientists Lift the Lid on Reproducibility." Nature.com. Macmillan Publishers, 25 May 2016. Web. 19 Dec. 2016. "CRISPR: A Game-changing Genetic Engineering Technique - Science in the News."Science in the News. N.p., 31 July 2014. Web. 19 Dec. 2016. Cyranoski, David. "CRISPR Gene-editing Tested in a Person for the First Time."Nature.com. Macmillan Publishers, n.d. Web. 19 Dec. 2016. @harvard. "A Cinematic Approach to Drug Resistance." Harvard Gazette. N.p., 8 Sept. 2016. Web. 19 Dec. 2016. "How Science Goes Wrong." The Economist. The Economist Newspaper, 19 Oct. 2013. Web. 19 Dec. 2016. "Steps of the Scientific Method." Science Buddies. N.p., n.d. Web. 19 Dec. 2016.
Our goal is to increase awareness and documentation of female bird song for biodiversity collections so that we and other scientists can study this fascinatingly complex behavior. This citizen science project is part of an international research project involving researchers at the Cornell Lab of Ornithology (USA) and Leiden University (The Netherlands). Funding provided by the European Union’s H2020 research and innovation program under the Marie Skłodowska-Curie (grant agreement No. 703999-YnotSing). In 2014, we published the most extensive survey of female bird song, which showed that female song is widespread and was likely ancestral in songbirds. This conclusion was based on information from species accounts for over 1,000 species of songbirds. For each species, we compiled evidence for whether female song is either present or absent. This resulted in concrete information for 323 species. Of these, 71% had female song. We then used a process called ancestral state reconstruction to map this information onto a phylogenetic tree, a representation of the relationships among bird species. This revealed an overwhelming 92% likelihood that the last common ancestor of all songbirds must have had female song. These findings have major implications for how we think about bird song: (1) female bird song is more common than previously thought, (2) bird song originally evolved in both females and males, and (3) the current day distribution of bird song evolved differently than we traditionally thought – female songs have been lost, rather than simply gains of elaborate male song. Thus bird song is a normal behavior in both female and male songbirds and to understand the evolution of complex bird song, we need to study female in addition to male song. So, now we need to document female songs! Next steps: a tree full of songs To understand how complex bird songs evolved, we need to understand how both male and female songs have changed over evolutionary time and what selection pressures are related to these changes. This is our goal. Using songs from biological collections and sound libraries, we will measure fine structural details of female songs and matched samples of male songs. This will allow us to quantify and overlay song on a phylogenetic tree of species relationships. We can then reconstruct how male and female song has changed over time. In addition, we can compare variation in male and female song to various environmental factors and behaviors that are indicative of specific selection pressures. This way, we can ask whether certain aspects of a bird’s environment or behavior are related to more elaborate songs. Pin-pointing these patterns will provide essential clues about what has led to the evolution of complex bird song in male and female songbirds. Female songs are currently very under-represented in biological collections. We need your help to gather female bird songs world-wide! Dr. Katharina Riebel, Assistant professor, Institute for Biology, Leiden University Dr. Mike Webster, Director of the Macaulay Library, Cornell Lab of Ornithology Dr. Lauryn Benedict, University of Northern Colorado Dr. Michelle Hall, University of Melbourne Dr. Naomi Langmore, Australian National University Dr. Robert Lachlan, Queen Mary University Dr. Sander Pieterse, Xeno-canto Foundation for Nature Sounds Prof Menno Schilthuizen, Naturalis Biodiversity Center and Leiden University Strategy & web design Dr. Karan Odom & Dr. Katharina Riebel Organizations & Funding This research is being conducted in association with The Cornell Lab of Ornithology This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 703999-YnotSing. Have any questions, remarks or just trying to get in touch? Send a mail to femalebirdsong [at] gmail.com and we’ll get back to you as soon as possible!
The venom in spiders helps them in several ways. It immobilize their prey, begins the process of digestion and is a defense against enemies. Venom is a complex mixture of substances, but the toxins are usually only a single substance. Venoms act in different ways and affect different parts of the bite victim. The main types of venom are Venom glands are located above the fangs or chelicerae. Venom ducts cross the chelicerae and open near the tips. The spider family Uloboridae are the only group in Australia that do not have venom glands. Venom glands originated as digestive glands, which aided in the external digestion of prey. Although funnel-web spiders are widely distributed throughout the southeastern Australia, including Tasmania, the only species so far proven to be dangerous to humans are largely limited to the eastern part of New South Wales and southeast Queensland. The only known killer is the Sydney funnel-web spider, which is found mostly in the Sydney region, north to Newcastle and south to the Illawarra region. The antivenom for the Sydney funnel-web spider has also proved to be effective for various other species of funnel-web. The protein toxin, delta-atraxotoxin, present in the acidic venom is also thought to be the prevalent compound which causes the severe effects in humans. Other mammals seem to be unaffected by the funnel-web spider venom. The toxin produces a rapid effect on the nervous system. Though there have been 13 recorded deaths from funnel-web spider bites, some cases do not always develop severe symptoms. However, the same precautions first aid should be administered because, if untreated, a major bite may cause death within an hour. First aid treatment involves the application of a pressure-immobilization bandage, the same treatment as applied to a snake bite. The entire affected limb is bandaged firmly and, wherever possible, is further restricted in movement by the application of a splint. The large fangs and acidic venom make the bite very painful. Bite symptoms start early, beginning with tingling around the mouth, twitching of the tongue, profuse salivating, watery eyes, sweating and muscle spasms. Hypertension and an elevated heartbeat occur which, when combined with respiratory distress may be very severe and potentially lethal. The antivenom from the red-back spider can also be used to treat bites from the black widow spider, an infamous killer from the Americas. The venom from the female red-back spider is known as a multi-component because it is made up of a family of protein toxins, the latrotoxins being the most prominent. One of these, alpha-latrotoxin, is effective in mammals, including humans, causing over stimulation of neural pathways throughout the body with a wide range of effects. Some of the effects include a stinging sensation when first bitten which can become excruciatingly painful, draining of the lymph nodes in the groin, pain throughout the abdomen, chest, neck and head, profuse sweating, mild to severe hypertension and nausea. The initial pain of the bite usually means the bite is detected immediately, however, the red-back bite is one of the few spider bites with which antivenom can be effective a few days after the bite occurs. First aid treatment for red-back bites is different to that for funnel-webs. Do not apply a constrictive bandage. In fact the only action taken should be to administer ice packs to the bite site to help reduce the pain and then seek medical attention immediately. Only the female red-back spider is dangerous. While the female is large and distinctive with her shiny black body and bright red abdominal stripe (though not all specimens posses this marking), the male red-back is small and insignificant and has a complex pattern including white and, occasionally, yellow markings. As the red-back is not a wanderer, most bites occur when the spider's web has been pulled down or disturbed. Less than 20% of all red-back spider bites actually result in significant envenoming. Red-back spiders usually make their webs under objects, with droplines to the ground or another flat surface. They are found most commonly under shelves, bottom rails of fence lines, under outdoor furniture, even in cupboards indoors. If you have red-backs in your area check thoroughly before putting your hands underneath items such as flower pot rims, bricks, tables, etc.
How can martian gullies--thought to be caused in part by seepage and runoff of liquid water--be distinguished from the more typical, "dry" slope erosion processes that also occur on Mars? For one thing, most--though not all--of the gully landforms occur on slopes that face away from the martian equator and toward the pole. For another, slopes that face toward the equator exhibit the same types of features as seen on nearly every other non-gullied slope on Mars. The example shown here comes from northwestern Elysium Planitia in the martian northern hemisphere. The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution view (A, left) shows a portion of a 10 kilometer-(6.2 mi)-diameter meteor impact crater at a resolution of about 9 meters (29.5 ft) per pixel. The crater is shown in the context image (B, middle). The north-facing (or, pole-ward) slope in the MOC view is shadowed because sunlight illuminates the scene from the lower left. In this shadowed area, a series of martian gullies--defined by their erosional alcoves, deep channels, and apron deposits--are seen. On the sunlit south-facing (or equator-ward) slope, a scene more typical of most martian impact craters is present--the upper slopes show layered bedrock, the lower slopes show light-toned streaks of dry debris that has slid down the slope forming talus deposits that are distinctly different from the lobe-like form of gully aprons. The picture in (C) has been rotated so that the two slopes--one with gullies (right) and one without (left)--can be compared. The crater is located at 36.7°N, 252.3°W. The MOC image was acquired in November 1999 and covers an area 3 km (1.9 mi) wide by 14 km (8.7 mi) long; north is toward the upper right (in A) and it is illuminated by sunlight from the lower left. The Viking 1 orbiter context image (B) was obtained in 1978 and is illuminated from the left; north is up. The MOC image has been rotated in the Explanatory Figure (C) such that north is toward the upper left, illumination is from the lower right.
Native or Introduced: Nutrient Removal Rating: Rooted or Floating: Full sun to part shade Maximum Water Depth: Arrow arum produces thick roots that serve as underground storage organs. Clusters of basal leaves arise from a short stem. Leaf petioles are green to purple-green, growing to 2 feet in length. Leaf blades are medium green, arrowhead-shaped, and measure 10-18 inches in length. Lobes are rounded rather than pointed. Inflorescences are 2.5-10 inches across and consist of a green spathe tube that opens at flowering to reveal a spadix that can be nearly as long as the spathe. Flowers are borne on the spadix and are pale green to greenish white in color. Flowering occurs from spring to late summer. Following flowering, green berries form attached to the spadix. Fruits mature during the summer and fall. Arrow arum lives in wetland areas such as bogs, swamps, freshwater tidal marshes, and ditches. Additionally it inhabits the edges of ponds, lakes, and rivers. It is most commonly found in the Atlantic Coastal Plain. The range of this species is currently expanding. Flowers of arrow arum are pollinated by a specialist pollinator - the chloropid fly. This insect uses inflorescences for mating sites and larval food sources. Female flys lay eggs in the inflorescence. After hatching, the larvae feed on the rotting male portion of the flowering structure.
What is an EKG? An EKG is a recording of the electrical activity occurring within the heart each time it contracts. What can be detected on an EKG? This test can reveal many things about your child's heart such as heart rate, rhythm, and various other anatomical findings. How is the test performed? A technician will place electrodes (stickers) on various parts of the chest, arms and legs. They do not hurt while being placed on or coming off, and your child will not feel anything while the test is being performed. The electrodes are attached to wires that are connected to a machine. It will then make a print out of the electrical activity occurring each time the heart contracts. How long will the test take? It takes approximately two to three minutes to attach the electrodes and only about 30 seconds to record the heart beats. Your child must lie as still as possible or an accurate recording will not be possible. Infants and toddlers may drink a bottle to help them lie still. How will I be informed of the results? Within 24 hours of the test being performed, a pediatric cardiologist will interpret the EKG. You will receive the results from the doctor who ordered the test, usually your pediatrician or a pediatric cardiologist.
Language and social relations One of the 'suggested topics' from the IB Language A: Language and Literature guide for Part 1 is 'language and social relations'. As we look at how language is used in various contexts, we cannot avoid studying social relations and the status of different people within a society. We will need to look at factors such as different accents, different word choices, different grammatical structures, and ask ourselves how they are received in different contexts, and why they are used in different contexts. How is language used as an instrument to show social, racial and class differences in various texts? Why are certain forms of language associated with certain social statuses? When is language used to exclude? to include? Why?
The astrolabe was the most widely used scientific instrument in the middle ages. Nevertheless, its origins remain uncertain. The earliest surviving instruments date from medieval Islam. However, Greek and Syriac texts testify to a long theoretical and practical development that extends back to the second century BCE. The underlying mathematical principle of stereographic projection was described by Hipparchus of Nicaea (fl. 150 BCE). Less than two centuries later, Vitruvius (died post 27 CE) described a type of clock that depended on a similar stereographic projection. His suggestion that Eudoxus of Cnidos (ca. 408-355 BCE) or Apollonius of Perga (ca. 265-170 BCE) invented the rete or spider—the network of stars—almost certainly refers to the sundials he was discussing in the passage. Claudius Ptolemy (fl. 150 CE), the most famous astronomer from antiquity, wrote an extensive theoretical treatment of stereographic projection in his Planisphaerium, which included a short discussion of a horoscopic instrument. Although he described an instrument that resembles an astrolabe, including both a rete and the stereographic projection of a coordinate system, Ptolemy’s instrument does not seem to have included the apparatus needed to make direct observations and thus to measure the altitude of the sun or stars. 07 February 2012 Of Astrolabes and Other Things PACHSmörgåsbord is always an enjoyable read - their audience is serious, engaged, and discerning. They have a terrific post on the history of astrolabes. Go check them out; a taste:-
It refers to the statistical material which the investigator originates for himself for the purpose of the enquiry in hand. In other words, it is one which is collected by the investigator for the first time e.g. if the cost of living of workers in a city are to be computed, then the information regarding the facts collected by the investigators or enumerators would be termed as Primary data. In India there are various agencies which collect primary data e.g.. National Sample Survey (NSS), State Level Economic and Statistical Departments etc. When we use primary data, it is called raw material. According to Wessel, “Data originally collected in the process of investigation are known as primary data.” - Degree of accuracy is quite high. - It does not require extra caution. - It depicts the data in great detail. - Primary source of data collection frequently includes definitions of various terms and units used. - For some investigations, secondary data are not available. - Collection of data requires a lot of time. - It requires lot of finance. - In some enquiries it is not possible to collect primary data. - It requires a lot of labor. - It requires a lot of skill.
Several coils of ribbon. - The definition of a coil is something rounded into a spiral or a series of such spirals. An example of a coil is a mattress spring. - Coil means to wind around or gather into a circular form. An example of coil is for a snake to wrap itself around a tree. Origin of coilMiddle English coilen, to select, cull ; from Old French coillir, to gather, pick ; from Classical Latin colligere, to gather together: see collect - to wind around and around - to move in a winding course - anything wound or gathered into a series of rings or a spiral - such a series of rings or a spiral - a single turn of a coiled figure - a series of connected pipes in rows or coils - a roll of postage stamps for use in a dispenser or vending machine; also, a stamp from such a roll - Elec. a spiral or loop of wire or other conducting element used as an inductor, heating element, etc. Origin of coilEarly Modern English ; from uncertain or unknown; perhaps - a. A series of connected spirals or concentric rings formed by gathering or winding: a coil of rope; long coils of hair.b. An individual spiral or ring within such a series. - A spiral pipe or series of spiral pipes, as in a radiator. - Electricity a. A wound spiral of two or more turns of insulated wire, used to introduce inductance into a circuit.b. Any of various devices of which such a spiral is the major component. - A roll of postage stamps prepared for use in a vending machine. verbcoiled, coil·ing, coils - To wind in concentric rings or spirals. - To wind into a shape resembling a coil. - To form concentric rings or spirals. - To move in a spiral course: black smoke coiling up into the sky. Origin of coilProbably from obsolete French coillir, to gather up, from Latin colligere; see collect1. Origin of coilOrigin unknown. (third-person singular simple present coils, present participle coiling, simple past and past participle coiled) - To wind or reel e.g. a wire or rope into regular rings, often around a centerpiece. - A simple transformer can be made by coiling two pieces of insulated copper wire around an iron heart. - To wind into loops (roughly) around a common center. - The sailor coiled the free end of the hawser on the pier. - To wind cylindrically or spirally. - to coil a rope when not in use - The snake coiled itself before springing. From Middle French coillir (“to gather, pluck, pick, cull”) (French: cueillir), from Latin colligo (“to gather together”), past participle collectus, from com- (“together”) + lego (“to gather”); compare legend. - 1624, John Smith, Generall Historie, in Kupperman 1988, p. 162: - this great Savage desired also to see him. A great coyle there was to set him forward. - 1704, Jonathan Swift, A Tale of a Tub: - they continued so extremely fond of gold, that if Peter sent them abroad, though it were only upon a compliment, they would roar, and spit, and belch, and piss, and f—t, and snivel out fire, and keep a perpetual coil, till you flung them a bit of gold [...].
The Mexican Duck (Anas diazi, and see below) is a dabbling duck in the genus Anas which breeds in Mexico and the southern USA. Most of the population is resident, but some northern birds migrate south to Mexico in winter. Both sexes of this 51-56 cm length bird resemble a female Mallard, but with a slightly darker body. The Mexican Duck is mainly brown, with a blue speculum (= distinctive wing patch) edged with white, obvious in flight or at rest. The male has a brighter yellow bill than the female. Call / Vocalization: The male has a nasal call, whereas the female has the very familiar "quack" commonly associated with ducks. Diet / Feeding It is a bird of most wetlands, including ponds and rivers, and usually feeds by dabbling for plant food or grazing. Nesting / Breeding It nests usually on a river bank, but not always particularly near water. Although a species of least concern, the Mexican Duck is undergoing a slow but marked decline due to destruction of habitat and overhunting. It hybridizes with Mallards which are better-adapted to utilizing habitat altered by human activity and thus are spreading throughout this range. Concern has been expressed that this combination of factors may ultimately lead to the disappearance of the Mexican Duck as a recognizable taxonomic entity (Rhymer and Simberloff 1996, McCracken et al. 2001, Rhymer 2006), but fairly limited measures such as wetland preservation and preferential hunting of drake mallards would prevent this. This species was formerly - and sometimes still is - considered a subspecies of the Mallard, as Anas platyrhynchos diazi (AOU 1983). This may not be correct, however, as careful analysis of mtDNA control region sequence data - taking into account hybridization events - indicates it is the southwestern relative of the American Black Duck and shares a fairly recent common ancestry with this species (McCracken et al. 2001). Including the Mexican Duck in the Mallard is a relict from the usual practice of much of the mid-late 20th century, when all North American "mallardines" as well as the Hawaiian and Laysan Ducks were included in the Mallard proper as subspecies. This was based on the assumption that hybridization, producing fertile offsprings, is an indicator of lack of speciation. Rather, in these birds it indicates a fairly recent allopatric radiation, which has not yet established solid barriers against gene flow on the molecular level; mate choice is conferred by cues of behavior and plumage in the mallardine ducks, and this, under natural conditions, has precluded a strong selective pressure towards establishment of genetic incompatibility. Copyright: Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from Diet / Feeding: Ducks feed on larvae and pupae usually found under rocks, aquatic animals, plant material, seeds, small fish, snails, and crabs. Instead of "teeth," ducks have serrations (saw-like edges) on their bills that allow them to filter food out of the water. Captive birds are often fed commercially prepared duck food pellets - if there are insufficient natural resources available to sustain them. As they feed on insects, they are very useful in ridding gardens or lawns of harmful bugs. Feeding Ducks ... We all enjoy ducks and many of us offer them food to encourage them to come over and stay around - and it works! Who doesn't like an easy meal! However, the foods that we traditionally feed them at local ponds are utterly unsuitable for them and are likely to cause health problems down the road. Also, there may be local laws against feeding this species of bird - so it's best to check on that rather than facing consequences at a later stage. - Foods that can be fed to Ducks, Geese and Swans to survive cold winters and remain healthy when food is scarce in their environment. Please note that feeding ducks and geese makes them dependent on humans for food, which can result in starvation and possibly death when those feedings stop. If you decide to feed them, please limit the quantity to make sure that they maintain their natural ability to forage for food themselves - providing, of course, that natural food sources are available. Please Note: The articles or images on this page are the sole property of the authors or photographers. Please contact them directly with respect to any copyright or licensing questions. Thank you. The Avianweb strives to maintain accurate and up-to-date information; however, mistakes do happen. If you would like to correct or update any of the information, please send us an e-mail. THANK YOU!
As a whole there are around 80 – 90 recorded species of cetacea in existence today. Measuring in at around 9 feet this whale is currently considered the smallest of the whale species and makes up one of three species within the sperm whale family. Like its other family members this whale has a spermaceti organ in its head, which is how this whale was given its name. Due to their small size, slow behavior and solitary lifestyle these whales are very difficult to observe in the wild (let alone spot) so only a limited amount of information is currently known about them. Physical Characteristics and Appearance As stated previously when fully grown the dwarf sperm whale measures in at around 9 ft. long and weighs an average of 400 lbs. to 600 lbs. Dwarf sperm whales are very similar in appearance to the pygmy sperm whale but have a slightly larger dorsal fin. The center of its body is stocky but tapers down the closer you get the tail and flukes. They have a bluish gray coloring with a lighter colored under body. The dwarf sperm whale may have anywhere from 16 – 24 teeth on its lower jaw and up to 6 teeth on the upper jaw. When threatened the dwarf sperm whale is able to produce a dark red ink which is believed to be used to blind and disorient its prey so that it can escape. In some ways the ink it produces functions similar to the ink of an octopus that is trying to escape a predator. As with other toothed whales the dwarf sperm whale has a single blowhole that it uses to breathe, however the length of time these marine mammals can dive for before resurfacing for air is unknown. Because these marine mammals are part of the toothed whale suborder they use echolocation to help them navigate the ocean, locate potential prey and avoid attacks from predators. Dwarf sperm whales prefer warmer tropical climates and are most commonly found in the waters of the continental shelf. They are also believed to be more coastal than their other two family members of the sperm whale family (the sperm whale and pygmy sperm whale). Although there are no official estimates on population size it is believed that there are at least 10,000 – 15,000 dwarf sperm whales inhibiting the ocean. Social Structure and Communication These whales are primarily solitary animals although they may occasionally be seen traveling in small pods of up to 10 members. When it comes to social activities these marine mammals are fairly inactive and rarely if ever seen performing acrobatics behaviors such as breaching and tail slapping. In most cases they are either swimming very slowly or logging (floating motionless) in the water. While the reason for this behavior is unknown their inactive nature may help them stay undetected by predators looking to hunt them. When they do communicate vocally there communication often consists of high pitched clicks and whistles which can be used for both echolocation and social interaction. Unfortunately not much is understood about the breeding habits of the dwarf sperm whale. The average gestation period for dwarf sperm whales is 9 – 11 months. Baby whales measure between 3.3 – 4 feet at birth and typically weigh between 85 – 110 pounds. After birth the baby whale is likely nursed by its mother and fed milk until it can hunt for food on its own. once the dwarf sperm whale reaches sexual maturity between 2.5 – 5 years it is then able to mate and reproduce its own offspring. In terms of lifespan it is currently believed that these whales only live until their mid 20’s. Little is known about the dwarf sperm whale. They rarely ever approach humans or boats and prefer to keep their distance. Attempts to hold them in captivity have failed due to the whales inability to survive in small man-made habitats such as aquariums. These whales are however still being actively hunted and killed in certain parts of the world due to their coastal nature which makes them easier targets than other whale species. In addition to being hunted these marine mammals have also been found accidentally entangled in fishing nets and may be endangered by polluted waters and/or food in and around the coast line. Depending on how commercial their environment is there is a possibility of being struck by passing boats. Unfortunately no solid information exists regarding possible natural threats that the dwarf sperm whales may face, however it is possible that these marine mammals may be attacked by killer whale or sharks inhibiting their local environment as both of these animals are known to hunt and kill other whale species. Attacks from killer whales however may be less common in certain areas as some killer whale populations (depending on where they live) may stick to a diet that consists almost exclusively of fish and other small prey. As stated earlier when the dwarf sperm whale is attacked it will release a dark ink from its body to blind potential predators. As they escape their flukes help disperse the ink in the water to help increase the ink cloud and make it difficult for them to be seen. Echolocation may also serve as an early warning system by helping these marine mammals detect nearby threats in advance before they can attack the dwarf sperm whale. The dwarf sperm whales coastal nature may also help protect them from larger animals that live further out to sea. As with other marine mammals dwarf sperm whales are a protected species and individuals caught hunting these marine mammals could face steep fines and even jail time. Note: Due to difficulty observed these animals it is unsure how abundant or endangered their population may be.
Maybe your child is acting differently and you don’t know what to do next. As a parent of a child with an intellectual or developmental disability (IDD), it can be hard to make sense of your child’s feelings and behavior all of the time. Maybe they’re getting treatment or support services, yet something still isn’t right. The truth is that approximately 30-50% of children with IDD may also have mental health conditions, according to research in the Journal of Intellectual and Developmental Disability. That’s more than the average for all other children. Unfortunately, these conditions can go under the radar. If you think your child might be having mental health symptoms, this page has ideas on how to talk to your health-care provider and the people already working with your child. And you can go to our page on Mental and Behavioral Health to learn more. You have the power to ask about mental health support for your child. Mental health conditions directly affect the quality and length of someone’s life. This means that paying attention to mental health really can improve things. That’s true for all children and adults, but especially for children with IDD. No matter what abilities your child has, helping them have mental wellness is important too. There are different reasons why people with IDD might have more mental health needs. They might have more stress and social challenges that are hard to cope with. They may have limited language abilities or nervous system symptoms that affect mental health. They are at a higher risk of experiencing trauma– things like abuse, neglect, bullying, restraint, and more. And trauma might spark mental health symptoms. Common mental health diagnoses in children with IDD are anxiety, attention deficit hyperactivity disorder (ADHD), and conduct disorders. When a person has both a developmental disability and a mental health condition, it’s called “co-occurring disorders” or sometimes called “dual diagnoses.” Our page on Finding Mental Health Resources has even more information on mental health providers and programs to help your child. Below, there are tips on how to start a conversation about mental health with your child’s health-care provider too. And here are some other pages on this website about mental health: There are few big myths about children with IDD and mental health conditions. Some people think that children with IDD can’t have mental health conditions. Or that standard mental health treatment won’t work for them. Or even that mental health services won’t work in combination with the other services the child is getting. Those things are just not true. There’s no reason why a child with an IDD can’t also have one or more mental health conditions. The important thing to know as a parent is that it can be easy for anyone – family, teachers, therapists, caregivers, other service providers – to misunderstand your child. The caregivers and professionals working with your child might not realize that a mental health condition is causing certain challenging behaviors and think that it’s because of your child’s disability. So, instead of going straight into developing something like a behavior intervention plan (BIP), you can ask that the people working with your child look closer at your child’s mental health. If your child’s personality or behavior seems to change suddenly, it’s a good time to stop and ask questions. It might be that they need mental health services. You can help your child and the people working with them figure that out. Maybe your child can explain what feels different or wrong. Maybe they can’t. Either way, if they are acting differently and you are concerned, there is support available. You might look for mental health help for your child if they: You can learn more on our page on when to get mental health help for children. Working with a health-care provider to diagnose a mental health condition and find the right treatment for your child might take a lot of patience. Especially if your child has a hard time communicating what’s going on with them. You can ask for more time to talk or a longer appointment. Together, you, your child, and their provider can take a closer look at mental health. Here are some ideas to help the conversation along: When talking to a health-care or mental health provider, there are some questions you and your child can ask to learn more and make the best decisions: Above all, know that you and your child are not alone in this. There is growing research and information about mental health treatment for children with IDD; more and more mental health providers are learning about the best ways to help.
A large celestial body, usually wholly gaseous, massive enough to initiate (or to have once initiated) nuclear reactions in its central region. Stars are classified in various ways, with these basic classifications going all the way back to late Industrial and Atomic Age Old Earth. The Harvard system uses a temperature sequence based on spectral characteristics. The sequence is O B A, F G K M, with decimal subdivisions, so that G5 is half way between G0 and K0. The Morgan, Keenan, and Kellman system classifies stars by luminosity as well as temperature. They also gave numerical definitions of the Harvard spectral types and designated bright stars to be the standards. Another system assigned stars to two broad categories depending on composition, speed and location, as well as origin: Population I and Population II, with a rare Population III added. More advanced Interplanetary Age astronomy techniques and AI interest added further stellar taxonomies, many of which were inscrutable or seemingly irrelevant to baseline humans. Even today many of the old classifications are used by SI:<1 sophonts.
The Russian Revolution of October 1917 was one of the greatest upheavals of the twentieth century. Its leaders envisioned a new society, thoroughly reshaped in accordance with their radical program of social justice. A small group of advanced artists soon embraced this vision and sought to create new forms of art that would help bring the new society into being. Aleksandr Rodchenko (1891-1956) was among the most talented and prolific of these artists. This exhibition is the first in the United States to present a comprehensive overview of his work. Rodchenko was deeply committed to the ideals of the Revolution, and his work cannot be understood apart from the turbulent and ultimately tragic history of Russia in the 1920s and 1930s. The Romanov dynasty, which had ruled Russia for three centuries, collapsed during World War I, in February 1917. The October Revolution, led by Vladimir Il'ich Lenin and his Bolshevik Party, overthrew the democratic Provisional Government that had arisen after the abdication of the tsar. The Bolsheviks, soon calling themselves the Communist Party, set out to impose a militant dictatorship in the name of the working class. They emerged victorious in early 1921, after three years of bloody civil war, and in 1922 they renamed the Russian empire the Union of Soviet Socialist Republics (USSR). The growth of industry at the end of the nineteenth century was one of the forces that brought down the tsar, but in the early 1920s Russia remained an agricultural country largely populated by illiterate peasants. Technological progress was the cornerstone of the Communist social program, and it became a principal goal of Joseph Stalin, who won the struggle for power provoked by Lenin's death in January 1924. In 1928 Stalin launched his ambitious First Five-Year Plan of rapid industrialization and forced collectivization of agriculture, which exacted a great human cost. He ruled a brutal totalitarian state until his death in 1953. In the course of the 1930s millions of Russians were jailed or executed. Independent art was suppressed, and remnants of the revolutionary avant-garde survived only insofar as they adapted to the demands of Stalin's regime. Born in 1891, Rodchenko came into artistic maturity with the Revolution. From 1918 to 1921, while rising to prominence in the new cultural bureaucracy, he pursued a highly innovative program of abstract painting and sculpture. With other artists--including his lifelong companion, Varvara Stepanova--he founded the Constructivist movement. Associating the avant-garde goal of artistic progress with the political goal of social progress, the Constructivists regarded their systematic investigations of the material and formal logic of art as essential to the creation of a Communist society. In 1921, the driving logic of Rodchenko's theories and his ideal of social agency led him to declare the end of painting and to take up alternative mediums in the service of society. This bold stroke led him to a broad exploration of many fields of design, as well as photocollage and photography. In the 1920s, optimism and wit leavened Rodchenko's earnest fantasy of an ideal world put into order by the artist-engineer, but this fruitful paradox could not long survive in the political and cultural climate of Stalinism. Despite Rodchenko's efforts to adapt, he soon found himself at the margins of Soviet culture, and he spent much of the last two decades of his life in frustrated isolation. He died in 1956, the year that Nikita Krushchev denounced Stalin's crimes. Closely linked to the Russian Revolution, Rodchenko was also a paradigmatic figure of the European avant-garde between the two World Wars. He inherited the pre-war avant-garde's probing self-consciousness about the workings of art, then used it to challenge the insularity of the avant-garde. Ceaselessly reinventing himself, he expanded the boundaries of each of the many mediums in which he worked. But just as Rodchenko's social engagement fostered his artistic innovations, it embroiled him in a great tragedy, as utopian aspiration yielded instead a violent dictatorship. © 1998 The Museum of Modern Art, New York
The Korean language belongs to the Altaic language family like Mongolian and Japanese. There are about 75 million people in the world who speak Korean, and according to a statistical ranking done in 2002, Korean is the 13th most spoken language in the world. Hangeul is the Korean writing system. It is similar to the Latin alphabet, inasmuch as each individual symbol represents a single sound, not an idea. As with many languages, Hangeul is written left to right. However, instead of each individual symbol being written next to each other on the same horizontal line, the symbols are grouped into characters, and each character consists of at least one consonant and one vowel symbol, representing a syllable. Thus a word of three syllables is written in Hangeul with three characters, each one composed of individual consonant and vowel symbols. Hangeul was devised by King Sejong the Great (r. 1418-1450), who wanted his people to have a writing system of their own. At that time, the learned and noble people wrote in classical Chinese. Korean Vowels and Consonants ☞ Click here to learn the vowels in more detail ☞ Click here to learn the consonants in more detail How to write Hangeul characters When we write Hangeul in a syllabic unit, there are six different ways to combine the vowel and consonant symbols. As illustrated in the following diagram, the individual Hangeul are arranged and proportioned to fit neatly into a square box, and are always read left to right, then top to bottom. \| CV CV CVV CVC CVCC CVVC \| (where C = consonant and V = vowel)
Asian Black Bear, Ursus thibetanus The Asian black bear (Ursus thibetanus), also known as the white-chested bear or the moon bear, is a species that holds a large range. This range includes northern areas of the Indian Subcontinent, most areas of the Himalayas, far eastern Russia, northeastern areas of China, Korea, and the Honshū and Shikoku islands near Japan. As is common to black bear species, the Asiatic black bear prefers a habitat within deciduous forests, mixed forests, deserts, and thornbrush forests. It can typically be found at elevation below 12,000 feet, choosing to move up to 11,480 feet in the Himalayas in the summer, and down to 4,920 feet in the winter. It was once thought to hold a larger range, which included France and Italy, but its range is now fragmented across the Asian continent. The Asiatic black represents the first primarily arboreal bear species, spending most of its time in the trees. It is thought that this species has not changed much genetically from Old World bears, and may even be the divergent species between modern ursine bears and Old World bears. It is also thought to be the descendant of the smaller Ursus etruscus or larger Ursus minimus, both extinct species. This species is closely related to the American black bear both genetically and physically. The Asian black bear can reach an average body length between 47 and 77 inches, with a tail length of up to 4.4 inches. Males are typically larger than females, reaching an average weight between 220 and 440 pounds, while females weigh between 143 and 198 pounds. In captivity, this bear can reach an average weight of 500 pounds. This species is similar in build to the brown bear, but is more slender. The skull of this species is small compared to other bears, but large compared to other animals. The Asian black bear has strong fore limbs that allow it to climb trees, although its hind limbs are typically weak. The front limbs are so strong that even if its back limbs are broken, it can climb trees with ease. This bear is known to walk on its hind legs often. The claws of this species are long and hooked, and allow the bear to dig and climb with skill. Its fur is shiny black on its entire body, and it is named for the white patch of fur that can be found on its chest. The Asian black bear holds seven recognized subspecies that vary in color and location. Ursus thibetanus formosanus can be found in Taiwan and it lacks the white patch of fur on its chest. Ursus thibetanus laniger, which can be found in a few areas including the Himalayas, is smaller than other subspecies and holds a brighter patch of chest fur. Other subspecies, like Ursus thibetanus mupinensis, are lighter in color, and one subspecies, known as Ursus thibetanus gedrosianus, is reddish in color. The largest subspecies of the Asian black bear is the Ussuri black bear, which can be found on the northeastern Korean and China peninsula and in Southern Siberia. The Asian black bear is thought to be able to breed with many other species of bear creating hybrids. One story, recorded in Monkeys on the Interstate by Jack Hannah, says that an individual captured in Sanford, Florida may have been the offspring of an escaped Asian black bear and a male American black bear. Another incident was recorded in Some notes on hybrid bears, written by Scherren and published in 1907, and stated that an Asian black bear successfully mated with a sloth bear a species that it is related to. In one Venezuelan zoo, an Asian black bear was placed in the same enclosure as a spectacled bear and the two individuals created many hybrid offspring. In Cambodia, one individual was captured near the Mekong River, which was thought to be a hybrid between an Asian black bear and a sun bear. The Asian black bear is typically active during the day, but it appears to be active during the night in human populated areas. Unlike other species of bear, it may live in small familial groups containing one adult male and female and two litters of cubs. This species will spend at least half of its life in the trees resting, eating, hibernating, sunning, and avoiding enemies. In some cases, older individuals may become too heavy to climb trees. When spending long periods in the treetops, these bears will build a nest like structure underneath themselves, which can be seen from the forest floor. Although most subspecies of this bear do not hibernate, those found in northern areas and pregnant individuals tend to make burrows in tall trees, caves, thickets, or sunny slopes. Hibernation lasts through the months of November to March. The Asian black bear can make a variety of vocalizations including roars, whines and grunts. It will hiss when alarmed or when delivering a warning, and will often scream when participating in a fight. If two bears approach each other without fighting, both will emit a “tut tut” noise, and when courting, both males and females can be heard making clicking sounds. The breeding season for the Asian black bear in Sikhote-Alin occurs between the months of June and August. Pregnant bears will enter hibernation early and emerge late with a liter between one and four cubs, although two is the most common. The cubs weigh only thirteen ounces at birth and will gain a small amount of weight by nursing while their mother hibernates. Cubs will be weaned at up to 29 months, but may not leave their mother until 36 months of age. Females typically produce their first litter at three years of age. The average lifespan of this species in the wild is about 25 years, but one captive individual died at 44 years of age. The diet of the Asian black bear consists of both plant materials and meat. Its diet includes insects, mushrooms, invertebrates, seeds, fruits, grasses, honey, bark, grains, and carrion. This species eats more plant material than brown bears but less than panda bears. Black bears do not have a specialized diet, but will feed on whatever is available in their area. This opportunistic feeding style is not always successful, however. When food is abundant, it is easy for these bears to consume large amounts of what is in the area, storing fat for the winter in the process. When food is not abundant, the bears may hibernate or move into valleys where larvae, hazelnuts, and rotting wood can be found. During late spring to early summer, fruit or green vegetation is the main food source for the Asian black bear, and during late summer to early fall, the bears will move into the trees to eat fruits and vegetation that grows higher up. This species eats more animal material than many other bear species, regularly hunting ungulates like serow, wild boars, muntjacs, water buffalo, and domesticated livestock. The Asian black bear does not fall prey to larger predators because there are none in its range, but can be killed by leopards, tigers, and packs of wolves. This species typically overpowers Amur leopards in conflicts in densely forested areas, but in open areas, the leopard typically wins. Amur leopards and occasionally Eurasian lynxes prey upon Asian black bear cubs. Tigers are the major threat to Asian black bears, excluding humans, and Russian hunters often come across the remains of bears that have been attacked by tigers. If the bear is not killed by the tiger, it may escape into the treetops and wait for its foe to leave. Sometimes, the tiger does not actually leave and will attack the bear again once it is back on the ground. Tigers will only attack black bears that weigh less than 130 pounds, so adults that are over five years of age are usually safe from predation. These bears may steal the tiger’s kill, although there have not been many recorded occurrences of this. The Asian black bear holds a range that overlaps with those of many other bear species, including brown bears in far eastern areas of Russia, sun bears in Southeast Asia, and sloth bears in southern and central India. Himalayan brown bears prefer to avoid the Asian black bear, but Ussuri brown bears have been known to attack. The exact population number of the Asian black bear is not known. Japan has given an estimate between eight and fourteen thousand bears, while Russia estimates a population between five and six thousand bears. Other estimates include one thousand bears in Pakistan and seven to nine thousand in India. Estimations for the populations in China number between fifteen and forty-six thousand bears, although the government has given an estimate of twenty-eight thousand. There is not enough scientific data to support these estimates. Three subspecies of the Asian black bear are located in China in different areas in the region. In Russia, this bear’s range is quite large reaching the shore of the Amur, but within the Ussuri krai its range is limited to Manchurian type forests. The Asian black bear has appeared in literature and folklore in many areas of its range. Japanese culture associates the Asian black bear with the mountain spirit yama no kami. It is also characterized in many forms including the “mountain father” or yama no oyaji, the “mountain uncle” or yama no ossan, the “mountain man” or yamaotoko, and a mother and her beloved child. Because these black bears are solitary, they are sometimes known as the “lonely person” or sabishigariya. In lowland Japan, these ears do not appear often in folklore, but does appear in folklore from upper areas of Japan due to their economic value. In Niigata, Kituarahara-gun folklore speaks of the Asian black bear receiving its white patch of fur when yama no kami, or the mountain spirit, presented the bear with an amulet wrapped in silk. After removing the amulet, the bear gained a new white marking. The Asian black bear appears in Hindu mythology as Jambavantha, Jamvanta, or Jambavan. Jambavantha is said to have lived between Treta Yuga and Dvapara Yuga, and appears in the epic called Ramayana, in which it helps Rama find his wife, Sita, who was captured by Ravana. The Asian black bear appears in The Life of Pi, written by Yann Martel, when the protagonist’s father describes the species as one of the most dangerous creatures in his zoo. The Asian black bear, like the sun bear, is easy to train and is often kept as pets or used in entertainment. This species is among the most often used in circus acts because of its capacity to learn. Bears are commonly kept as pets in China and Korea, and can be fed a wide variety of foods including cassava, grains, rice, maize, sweet foods, animal fat, and pumpkins. In China, it is believed that milking the gall bladders of these bears can bring good fortune. Although the Asian black bear is typically shy, it is known to be more dangerous to humans than the Eurasian brown bear and the American black bear. One expert asserts that this behavior is an adaption that allows the bear to defend itself better against tigers. There are reports that one hospital receives dozens of bear victims each year. It is thought that these bears will stand on their hind legs when attacking, typically biting the legs and arms before biting the head. There are no records of Asian black bears attacking humans in Taiwan or Russia, but attacks have been increasing in India and in the western and northwestern areas of the Himalayas. Recent attacks have occurred in Langtang and Junbesi National Parks in Nepal ad in neighboring areas. Between the years of 1979 and 1989, there were nine reported deaths from black bear attacks. Two attacks, which occurred in 2009 in different areas, consisted of a black bear encountering groups of people, and resulted in the death of an entire group of six people and two individuals in a group of four. It has been found that the majority of attacks occur when a human surprises the bear, especially near its den or when eating. This species is considered more dangerous than brown bears because they occur in less open areas, making it more difficult for the black bears to know that humans are in the area. The Asian black bear is threatened by a variety of factors in different areas of its range. In China, habitat destruction caused by deforestation is threatening these bears. This threat is most prominent in the Ganshu, Sichuan, and Shaanxi provinces, where twenty-seven forestry initiatives have been created between the years of 1950 and 1985. Because of these human developments, the range of bears in this area was reduced to one fifth of its original size between the 1940’s and the 1990’s. This habitat loss has caused the Asian black bears in these provinces to face other issues like fragmentation and a limited gene pool. The decrease in Asian black bear populations in China have also occurred due to overhunting. The gall bladders, paws, and cubs are prized and highly valued. This species is thought to be a pest to crops, and so harvests are common. In the decade between 1950 and 1960, about one thousand bears were killed each year. Hunting declined slightly by the 1970’s and 1980’s due to a decrease in price on bear furs, but hunting is still a major threat to the species in that area of its range. Poaching of Asian black bears also occurs in Japan, but authorities do not often stop this threat. The bears are thought of as pests in this area, but trapping has become a more popular means of removing problem bears. Habitat destruction is also a threat in Japan. In India, overhunting is the main threat to this species. In Vietnam, hunting and habitat destruction threaten the Asian black bear. Hunting of this species does not occur in Taiwan, but the bears can be caught in steel traps meant for wild boars. Habitat loss in this area is not a major threat, although complications have risen in the transference of lowland hill country to the government and it is thought that this, as well as road development, may cause habitat destruction in the future. Black bears in South Korea are threatened by bear bile farming, a process in which the bears are farmed for their resources in traditional Asian medical practices. Bile farming is known to be inhumane. The Asian black bear has been protected in Russia 1983, but poaching is becoming and increasing issue. The demand for bear parts in Asia is so high that poaching in Russia in order to sell the parts in the Asian market is becoming common. It is though that many “loggers” of Korean and Chinese origin are only posing and take part in the illegal trade of Asian black bear goods from Russia to Asia, and there reports from Russian sailors that support this claim. The timber industry in Russia has been increasing for over thirty years, and this is causing a large amount of habitat loss to the bears in that region. These bears prefer to hibernate in hollow trees, but many of these trees are being cut down, forcing the bears to hibernate in areas that make them more vulnerable to tigers and hunters. The hunting of the Asian black bear for sport has occurred throughout its range for many years, but it is now only conducted illegally in Japan and Russia. The known number of poached bears in Russia is between seventy-five to one hundred bears per year, but it is though that up to five hundred can be killed. In 2004, sport hunting of this species was illegalized in Russia, but one hunting group claims to be able to help hunters catch at least four bears for a large sum of money. These hunters include people from The United States, Great Britain, Spain, Germany, Poland, and Finland. After Buddhism was introduced into Japan, some hunters devised a plan that would better suit the policies of not killing animals that the religion upholds. Locals in the Kiso area of the Nagano Prefecture no longer allowed hunting of these bears, and other locals created rituals that would appease the spirits of the killed bears. Traditions of hunters began to change, and one says that bears found without the white patch of fur are sacred and cannot be hunted. A similar tradition held in the Akita Prefecture stated that these bears were also sacred, and they were known by Matagi hunters as minaguro, meaning all black, or as munaguro, meaning lack chested. These bears in both regions were known to carry spirits called yama no kami, and if one of them were accidentally shot or killed, the hunter in question would give the ear to yama no kami and cease hunting for the rest of his life. The traditions held by the Matagi people also said that if a bear were killed in the mountains it would bring a bad storm, suggesting that animal spirits were linked to weather patterns. These people would typically hunt bears before or after hibernation in the fall, spring, and summer seasons, when one group would scare there bear into upper regions where another group would wait to kill it. Once a bear was killed, a ritual that could last up to two weeks was conducted, in which the people would pray for the spirit of the bear. In many Japanese areas, hunters would call bear hunts kuma taiji, meaning bear conquest. The term taiji was used when speaking of the slaying of demons or monsters. In Taiwan, the Taroko, Bunun, and Atayal tribes consider the actions of the Asian black bear to be so similar to those of a human that killing the bears is considered murder. If a bear is killed, it could bring disease, misfortune, and death to the one who killed it. It is known by the Bunun people as Aguman or Duman, which means devil, and if a hunter accidentally traps or kills a bear, it must be cremated within a cottage that the hunter builds by hand. The hunter must remain in the cottage alone until the harvest of millet is completed, because it is thought that if this does not occur, the crops will become black and ruined. Within the Tungpu area, Asian black bears are thought to be “third category” animals. This means that their actions and habits are restricted as far as can be from humans, so if one comes into a human populated area, it is thought to be a bad omen. If this occurs, the humans will either kill the bear or move into a different area. Although hunting of these black bears is permitted by the Paiwan and Rukai people, the Rukai believe that killing the bear will result in ill fortune. For this reason, they do not allow children to consume bear meat and it is not allowed inside any homes. Asian black bears are hunted not only for their organs or paws, but also for their fur, but the quality of the fur varies and is typically greasy. Experts agree that the fur is greasy, and this has been noted in a few written works. One expert wrote that this bear provides better fur, meat, and fat than the brown bear. Asian black bears in British India are hunted only for the grease from their fur. Bears that lived near human settlements were most often hunted in this area. In China, this species has been hunted since the Stone Age, because the bile within the bear’s stomach is highly valued in traditional medicine practices. Other parts of these bears are used in medicine, like the bones and fat. In Vietnam, Asian black bears can provide are large range of products and each bear is worth $1,500 to 2,250 U.S. dollars. The Asian black bear has been thought of as a pest in many areas of its range for many years. In lowland Himalayan areas, farmers in the past would place tall towers into their fields, and people would keep watch over the crops during the night. The guards would beat on drums periodically, to make sure no bears would enter the fields, but eventually, the bears became familiar to the drums and would raid the crops despite the farmer’s efforts. These bears cause damage to crops in isolated areas of Japan, eating different foods in spring, summer, and fall. In the spring months, these bears consume bamboo shoots, plums, corn, and watermelon during the summer, and sweet potatoes, persimmons, and rice in the fall. They cause significant damage to large crops like pumpkins or watermelons because they prefer to eat the seeds, leaving the meat and preventing farmers from using the seeds for future crops. The bears can damage timber productions because they strip the trees of bark to eat the sap. The Asian black bear is not only a pest to plant crops, but also to livestock. In Bhutan, one study found that eight percent of 1,375 livestock animals killed were prey to a black bear. The highest number of kills occurred in the summer and fall seasons, when plant crops were being harvested. Because of this, it is thought that livestock is hunted when plant materials are scarce. The Asian black bear and its subspecies are protected by law in many areas of their range. In China, it is protected from poaching by China’s National Protection Wildlife Law, which does not allow hunters to kill or capture the bears without the proper permit. In Vietnam, Decision 276/QD, 276/1989 does not allow hunting or exploitation of this species, and it is listed in the Red Book of Vietnam as an endangered species. In Taiwan, the Formosan black bear subspecies is listed as an endangered species under the Natural and Cultural Heritage Act, and was later classified as a Conserved Species Category I. It appears in Russia’s Red Data Book as an “infrequent species” and this makes it illegal to hunt them there. Despite this, experts in Russia suggest that hunting of this species should be legalized. The Asian black bear in India is protected by both Schedule I of the Indian Wildlife (Protection) Act and the Red Data Book in Appendix I of CITES, where it is listed as Vulnerable. However, it is difficult for authorities to protect the bears from poaching, because it is rare to have witnesses when prosecuting suspected poachers. This is even more difficult because there are no Wildlife Forensic Labs to trace the origins of any confiscated bear remains. India borders many other regions, many of which occur in mountainous areas, and these include Pakistan, China, Tibet, Nepal, Bangladesh, and Myanmar. It is difficult for authorities to maintain laws in all of these areas. In 1991, Asian black bear populations from five areas were listed as endangered by the Environmental Agency in the Japanese Red Data Book. These areas include West-Chugoku and East-Chugoku, Kii, Kyushu, and Shikoku. In 1995, two other populations located in the Shimokita and Tanzawa were listed as endangered. Besides these efforts, there have not been many other actions taken to protect the bears in this area due to a lack of information and effective conservation means. The Asian black bear species as a whole appears on the IUCN Red List with a conservation status of “Vulnerable.” Image Caption: cub on tree. Credit: Abu0804/Wikipedia (CC BY-SA 3.0)
Then and Now: Life in Early America, 1740–1840 Have you ever heard the expression, "The more things change, the more they stay the same?" Do you agree? Do your students? Does that old adage correctly characterize changes in America since the time of the Revolution? Using archival materials, re-creations, and classroom activities, help your students think about which aspects of everyday life — and the people who've lived it — have changed and which have stayed the same in the last 200 years. In what ways is everyday life today significantly different from everyday life 200 years ago? After completing the lessons in this unit, students will be able to List similarities and differences between the lives of people 200 years ago and people today (e.g., ways of obtaining food, drink, and clothing; having fun; forming organizations; living by rules and laws) Cite reasons for differences in the way people lived in earlier times and the way they live now Describe how changes in household tools, communication, transportation, recreation, and technology have changed the way people live and work
Asthma is an inflammation of the airways that has affected a large population globally at an ever increasing rate for the last forty years. Currently, this disease in last year alone affected approximately 300 million people around the world and this disturbing trend shows no signs of reversing or even slowing. The causes of this chronic disease aren’t exactly known, however it is believed to be the result of both environmental conditions and genetic predisposition of the individual afflicted with it. Pollens, dust, dry air, humid air, and pollution are thought to be prime factors in contracting an attack. The characteristics identified with asthma are spasms within the bronchial tubes, and difficulty in drawing air into the lungs. Some of the symptoms typical of an asthmatic attack are a tightness in the chest, a shallow breath, coughing and wheezing. It is given a specification within the asthmatic class in accordance with the recurring number of symptoms and how much air is exhaled in the span of one second (this is known medically as FEV1, or Forced Expiratory Volume) and the exhalation rate of flow at its maximum. As well, the disease can be identified as either extrinsic (atopic) or intrinsic (non – atopic). As mentioned above, it is believed that this chronic inflammation of the bronchial tubes is caused in part by environmental conditions. It follows, thus that the means by which to reduce the possibility of contracting an asthmatic attack is by taking precautions against breathing in the environmental triggers the likes of which are pollens, exhaust and dust to name only a few such irritants. In spite of the large number of deaths attributed to asthma, (a quarter of a million world-wide in 2009 alone) the better control and treatment of asthma and using a method to slowly degrade the symptoms, the outlook is favourable in terms of reducing deaths and the severe effects of asthma. The treatment of the symptoms of asthma as wheezing, coughing, chest constriction and low air intake is with a short response beta 2 agonist ( salbutamol for example is an excellent inhaler) and careful monitoring of environmental conditions.
The atmosphere affects the spatial and spectral distribution of the electromagnetic radiation originating from the sun before it reaches the earth’s surface, and it also attenuates the subsequently reflected energy recorded by a satellite sensor. Gas absorptions, molecule and aerosol scattering are examples of atmospheric processes that influence incident and reflected radiation. Knowledge of these processes, which are not constant over time, must be brought into play to correct for them the satellite sensor readings. Thus, the amount of reflected energy recorded by a sensor must be processed to separate the atmospheric disturbances from the actual reflectance that was emitted from the objects on the surface of the earth. This step may not be always be needed as it depends on the intended use of the satellite image. Atmospheric image correction requires information on the atmospheric conditions present at the time/period of image acquisition (Richter and Schläpfer, 2012). While atmospheric correction may not be important for certain applications (e.g., when conducting land cover classification for a single year), it is absolutely necessary when performing a time-series analysis in crop growth. For example, in comparing spectral characteristics of a pixel or group of pixels (an object) acquired on different dates, removal of the influence of atmospheric conditions prior to comparison is crucial. During atmospheric correction, the image pixel values (i.e., known as Digital Numbers — DNs) are converted to a physically interpretable measure, often referred to, and interpreted, as surface reflectance (Chen and Cheng, 2012; Richter and Schläpfer, 2012). This conversion generally entails two steps. The first is radiometric calibration, which involves (a) the conversion of DNs to radiance, and then (b) to top of atmosphere radiance. The obtained values can be interpreted as radiance observable just outside of the earth’s atmosphere; their derivation from the DN numbers can normally be done with just the metadata that is delivered with the image. Radiance is the amount of radiation, so it is an absolute figure. Reflectance is the proportion of the amount of radiation hitting an object, and the amount reflected off of it, so this is a ratio value. Top of atmosphere reflectance can be derived just like the radiance in step (b) above. In a next phase, the top-of-atmosphere reflectance is converted to surface reflectance (also known as bottom-of-atmosphere reflectance, or top-of-canopy reflectance or in vegetation studies). Top-of-canopy reflectance can be understood as reflectance as would be measured from just above the vegetation. This phase requires knowledge of atmospheric conditions present during the image acquisition time frame. The resulting image is called atmospherically corrected. Some image provider agencies (like the United States Geological Survey) now deliver atmospherically corrected images free of charge on their EarthExplorer website (search for “Landsat Surface Reflectance”). Atmospheric correction modules are scarce in open-source remote sensing applications (but see the recent ESA-NASA ACIX exercise). Even in proprietary software (like ATCOR and FLAASH for Erdas) atmospheric correction must often be acquired as a separate license module. A number of atmospheric correction methods can be implemented in normal RS/GIS tools or through home-brewn code. In the STARS automated image processing workflow, atmospheric correction is performed through the 6S radiative transfer model, a FORTRAN program developed and based on the MODIS atmospheric correction algorithm and adapted in the STARS project to cater for other image types (mostly as delivered by DigitalGlobe and RapidEye). Detailed information about the program can be found here. The atmospheric correction code eventually produces three outputs; the top-of-atmosphere radiance and reflectance, and the surface reflectance. In the current data format, to obtain 0–1 reflectance values from the cell values, one has to divide by 10,000.
High Flying Bugs Have you ever wondered what altitude insects reach when flying in the sky? Although there is much to be learned about insect physiology and how it handles high altitudes, scientists have developed a few techniques that help determine the height that certain insects can reach. By putting bumblebees into a chamber that mimics high altitudes researchers found that bumblebees can reach altitudes as high a mount everest, which is almost 30,000 feet. This is an impressive height when you consider that the highest flying bird reaches 37,000 feet. Flies and butterflies can even reach heights of just under 20,000 feet. However, higher altitudes means thinner air, and that means that flying insects will have to flap their wings much faster since the small amount of molecules in the air make it harder for wings to take advantage of lift. But the bumblebees will change the way they flap their wings to adapt to the change in oxygen. By studying the way insects fly at high altitudes we can learn more about engineering mechanisms of human flight. Do you think that learning about how insects fly at extremely high altitudes could help humans develop more sophisticated airborne vehicles? Leave a Reply You must be logged in to post a comment.
Healthy eating habits involve more than food choices Donna Nolan, a regional nutritionist with Eastern Health, wants parents to know that teaching a child to eat healthy means moving away from "getting their child to eat" and toward teaching them how understand when they are hungry or full. "In this approach, the parent is responsible for deciding what to serve a child, when and where. This builds a security for a child in knowing that he or she will be fed at regular times. The child decides what to eat from what is served and how much." This does not mean that children get to eat whatever they want whenever they choose. Snacks and meals should be available around every two hours and children shouldn't eat in between those times so they learn about how much to eat when they are hungry. Meals and snacks don't need to involve a big fuss, but parents need to consider that they are teaching family rules and expectations with each meal, so they should choose the environment carefully. Nolan advises, "What they need to be considering is 'Is this going to create a pleasant environment with minimal distractions?' So, they are focusing on the meal and the whole experience. You are trying to incorporate not only the food part but also the behaviours." Part of this pleasant experience is not pressuring the child about how much they are eating. When a smaller child says he is full and is told to eat one more bite, or a heavier child says she is still hungry and is told she has had enough, they are not learning to regulate their own hunger and they can feel overfull or deprived. "The whole purpose in this is to allow them to grow to their potential and some children are going to be tall and big and some are going to grow to be very petite people," Nolan says. "If your goal is to get them to develop healthy eating habits then whether they eat everything on their plate is not your marker of success. It is did they come to the table? Did they have something from what was there? Did they stop when they said they were full? Were they allowed to have seconds if they were still hungry?" Beverley Rose, a mom with two girls ageed 9 and 12, helps her daughters eat healthy by offering a large variety of foods every day, including fresh fruit and whole grains. They have a good breakfast, home-packed lunches, and a healthy supper, and, for her family, good eating habits include eating in the kitchen rather than elsewhere in the house. "We discourage eating in front of the TV, in the family room off the kitchen. The rec room in the basement has a dishwasher, fridge and sink for entertaining, so, we ask that they eat there only when entertaining friends. My girls may keep some treats from Valentine's, Easter, etc., in their bedrooms (hiding chocolate from Mom) and they will eat their special treats there, but we strongly discourage this, too, and ask that they eat in the kitchen." Eating together and offering interesting and nutritious choices has worked for Rose, since her daughters are now willing to eat a sophisticated menu. "They have been exposed to an extremely wide variety of food, much of which can be considered to be fine cuisine, thanks to their dad who has taken many courses and given all of us a mature palate for exceptional food. One of the most important things families can do to encourage healthy eating is to eat together. "When families eat together, there is opportunity for conversation, role modelling of eating behaviours." Nolan says, "Usually families who eat together eat more nutritiously, the children have a greater sense of belonging, and are less likely to be use drugs, or smoke." Beverley Rose's family follows this advice and she finds it does bring them closer together. "We eat dinner together at the kitchen table almost every night, and maybe in the dining room if need be. It's a great time to find out what happened in everyone's day, talk about upcoming events and homework, and chat about what's generally important to us. " "The girls benefit because they know that we are interested in their day and in their performance at school. They also know that they can discuss the difficult things and the things that are coming up and are really exciting for them...our sharing time." Teaching healthy eating habits to busy and reluctant children can feel like a challenge, but parents need to remember that it a process is just like anything you are trying to teaching your child. As Nolan says, "It's no different than a child learning how to walk, to talk (or) how to dress themselves, how to ride a bicycle. Few of us learn it overnight." Beverley Rose has the following advice for other parents: 1. Do not cook different things for each person - everyone eats the same prepared meal. 2. Cook a wide variety of foods for evening meals to ensure that everyone gets the nutrition the need. 3. Don't snack a lot, but recognize that you can't ban them entirely. 4. Set ground rules for when and where everyone eats regularly. 1. Remember that, to children, all foods are new foods and they may need to try something a number of times before they decide that they like it. Offer a new food with plenty of familiar foods so kids can try a small amount but still have other choices to fill up on. 2. Don't use pressure to get children to eat or stop eating. Plan what you will provide, and don't worry about the amount they eat. If children know they can eat until they are full, they will learn to regulate themselves. 3. Provide meals and snacks at approximately the same times each day so children know they can depend on their routine. 4. While the ultimate goal is to have children eat the right number of servings from the Canada Food Guide, parents shouldn't stress out about it. Serving sizes are actually quite small, and parents can usually reach the serving numbers by serving items from each food group throughout the day. Check out the following food resources: More information on this type of healthy eating approach: http://www.ellynsatter.com/ Canada's Food Guide: http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/order-commander/index-eng.php Mealtime Solutions for Your Baby, Toddler, and Preschooler: The Ultimate No-Worry Approach for Each Age and Stage by Ann Douglas
Show that the product of is an even number. This proof requires elementary knowledge in algebra and some manipulation of symbols. It is assumed that you already know or have proved that the sum of two even numbers is even, the sum of two odd integers is odd, and the sum of an odd number and an even number is odd. This proof is designed to be read by middle school and high school students, so it is written with details. The numbers and are consecutive numbers. There are two cases possible, the smaller number is odd or even. If the smaller number is odd, then is even. Now, odd multiplied by even is even. For the second case, if the smaller number is even, then the second number is odd. Now, even multiplied by odd is always even. Therefore, in any case the product of is even. Continue reading…
Camera manufacturers continue to invent new ways to make photography easier for us. One of these ways is to have a wheel of preset functions to dial in when we encounter varied photographic situations. For most people, they either don’t fully understand what the wheel symbols mean or they simply misunderstand what they mean. Let’s explore each of them so you can be more confident when using your camera and achieve the exact results you’re looking for. What Do the Symbols on My Camera’s Function Wheel Mean? First, I’d like to give you a quick tutorial on the basics of an exposure. This remains the same for film as well as digital cameras. The physics of photography require two things to achieve a proper exposure. Yes, both. Not one or the other. The law of physics require they both to work in conjunction with one another. - The first is an aperture. An aperture can be explained as how large the hole is when it opens up to allow light into the camera. Think of it in the same way the human eye functions. Aperture sizes range from very small to very large. Large apertures are used in low light conditions to increase the amount of light coming into the camera. Conversely, small apertures are used to limit the amount of light coming into the camera. Apertures are expressed as “F”, followed by a number. For example, F2.8, F4, F5.6, F8, F11, etc. The SMALLER the number the LARGER the hole. The LARGER number, the SMALLER the hole. This seems counter-intuitive but true. - The second is a shutter. Shutter speeds are explained as how long the aperture stays open. It is expressed in fractions of a second. For example, 1/1000 of a second, 1/500 of a second, 1/250 of a second all the way down to whole seconds, which are rarely ever used. The larger the number the faster it opens and closes. The smaller the number, the slower it opens and closes. The longer your shutter stays open, the more light will collect on your image. By the way, some cameras display these fractions with the denominator only (bottom number) such as 1000, 500, 250, etc. Some cameras display both the numerator and the denominator, such as 1/1000, 1/500, 1250, etc. The functions below are taken from a Nikon Digital SLR camera. Even if you don’t own a Nikon, many of these functions are very similar with most camera brands. I suggest you have your camera while reviewing these functions. - “S” – Represents “Shutter Priority”, NOT “Sports” as some people assume. Shutter Priority means you control the speed of the shutter – how long the shutter stays open. While the shutter is open, it will record anything it sees. When you keep your eyes open, you see continuous movement of objects. If you open and close your eyes very fast, you’ll tend to see a freeze frame of that object. Think of a strobe light in the dark. With a strobe, you don’t see movement, only a collection of still images, even when the subject is moving. Therefore, if you use a slow shutter speed, you can get blurry images for this reason. However, when you use a fast shutter, you can stop action. Generally speaking, you would choose a fast shutter speed for sports, speeding cars, dancing, etc. If you don’t want to freeze action, slow your shutter speed down and you may see the hem of a dancer’s dress moving (or blurring) to communicate movement in your images. This function will allow you to control how much movement you see in an image. Flash can also freeze images under certain circumstances, but that’s another lesson. The other function a slow shutter speed will offer is to pick up ambient light in the background when using flash. Have you ever taken a picture in a church but the background is so dark that no one knew where you were? Go to “S” and slow your shutter down. You’ll find the background begins to develop on your image. Practice dialing in “S” and find an index finger or thumb wheel close by and watch the numbers change. Practice taking the same image with different shutter speeds and observe the differences. In this function, you control the shutter, but the camera will choose the corresponding aperture to achieve a proper exposure. - “A” – Represents “Aperture Priority”, NOT “Automatic”. This controls how large or small the aperture will be. Aperture controls how sharp or blurry a background will appear. If you’re creating a portrait, you want the background to be somewhat blurry (or “soft”) to draw attention to the subject matter. However, if you’re visiting the Grand Canyon, you don’t want blur you want the entire image, from the foreground to the background, to be sharp. In that case, you would select a smaller aperture of F11 or F22. The number of feet in focus is referred to as “Depth of Field”. Dial your camera to “A” and practice changing the F-stops. Sometimes, you will not see the “F”, but only the number following it. In this function, you control the aperture, but the camera will choose the corresponding shutter to achieve a proper exposure. Just a note to clarify that zooming out or in with a zoom lens can also increase or decrease depth of field respectively. - “M” – Represents “Manual” mode. Manual means the camera is handing over complete control of the exposure to you. This means you control the aperture AND shutter. This is a function that can be extremely dangerous for the average person and is usually reserved for professionals. The only way for you to receive information as to the proper exposure settings (aperture and shutter) for your lighting situation is to have a separate, hand-held meter, independent from your camera. This meter will display which shutter and aperture you need to use. Professionals can use this mode because they have a separate meter packed among their equipment. - Green Camera Symbol (Auto) – Represents “Automatic” mode. Automatic means the camera is in complete control of the exposure. It will choose whatever aperture and shutter it pleases and you’re stuck with the results – good or bad. As you now know, handing complete control over to the camera is not always the best choice. If you know very little about photography but have still recorded some great images in “Automatic”, the honest truth is you were probably lucky. It was a luck of the draw and you were pleased with the aperture and shutter speed the camera chose for you. The reason you’re sometimes unhappy with your images is because you are unhappy with the settings your camera chose. This is why people who are serious about their photography must challenge themselves to understand and use other functions. By the way, “Automatic” also doesn’t allow you to control your pop up flash unit. The camera will pop it up at any and all times it sees fit – even when you don’t want it to. Basically, in this mode, the camera locks you out of all the camera’s other function buttons. - “P” – Represents “Program” mode – think of it as Automatic Plus. Program means that the aperture and shutter are still on automatic, but you now have access to the camera’s other function buttons such as ISO (the old ASA) “exposure compensation”, “exposure lock”, “auto-focus lock”, and others that Automatic mode didn’t allow. - A Circle with a Lightning Bolt Slashed – Dialing in this function tells the camera that you want to be on Automatic mode, but want to suppress the flash from firing. This is a great way to disable the flash when you want all your images to be exposed with only natural light. - Scene – “Scene” mode is a collection of several other conditions (baby, party, sunset, candlelight, beach/snow, silhouette, etc.) that are located in the menu. They placed the others in the menu because they couldn’t fit them all on the wheel. - Lady in a Hat – This symbol represents “Portrait” mode. This will enlarge your aperture to soften your background to make your subject pop. - Mountain – This is “Landscape” mode. It will choose a smaller aperture to increase the range of what you’ll see in focus. Do you remember the term? Depth of field. It will increase your depth of field so most everything in your image will be in focus. In landscape photography, everything in the scene needs to be sharply in focus. - Sport – The “Sport” mode will increase your shutter speed to freeze action so your son’s arm is not as blurry when he swings his bat. If it’s still not sharp, go to “S” and increase the speed. - Child – This function will speed up the shutter speed because children move quickly. This is similar to “Sport”, however, “Sport” has a much higher shutter speed. - Macro – “Macro” makes adjustments for close up photography for flowers, details, etc. - Night – “Night” mode slows your shutter down to bring out the details of a dark background. Remember, once your shutter slows down, blurriness can result. This is limited if you use a flash on your subject and I suggest a tripod with any night photography. Now that you understand your camera’s function wheel, you will be more confident in your photography and achieve the exact results you’re looking for! About the Author: Betsy Snow is a 17-year Photographic Artist who has won local, state and national awards for her work. In 2001, she earned the distinguished Florida Degree of Photographic Excellence. Betsy can be reached through http://www.betsysnow.com. Like This Article? Don't Miss The Next One! 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National Autism Awareness Month (April) Since the 1970's April has been designated as National Autism Awareness month. In recent years the prevalence of autism has increased dramatically, leading to an outpouring of support and awareness. Currently, 1 in every 88 children in America and almost 1 in every 54 boys have autism. Autism is a complex developmental disability that typically appears during the first three years of life and affects a person's ability to communicate and interact with others. Autism is defined by a certain set of behaviors and is a "spectrum disorder" that affects individuals differently and to varying degrees. Not only is autism somewhat of a burden to those that it affects but it is also costly. The lifetime cost of caring for a child with autism ranges from $3.5 million to $5 million, and that the United States is facing almost $90 billion annually in costs for autism. Since autism is not preventable at this point, it is no surprise that the annual cost is so high. On a brighter note, autism is treatable! Children do not "outgrow" autism, but studies show that early diagnosis and intervention lead to significantly improved outcomes. Some signs and symptoms that can be observed during early developmental years include: - Lack of or delay in spoken language - Repetitive use of language and/or motor mannerisms (e.g., hand-flapping, twirling objects) - Little or no eye contact - Lack of interest in peer relationships - Lack of spontaneous or make-believe play - Persistent fixation on parts of objects Information in this article was obtained from the Autism Society. For more information please visit: http://www.autism-society.org/ Information provided by Benjamin L. Gregory, student intern with Community Outreach.
Sorry, the comment form is closed at this time. Attachment is the basis for all early relationships. It is what shapes, forms and influences who we are and how we are with others. It is where we hurt and heal and learn how to manage. Human relationships across society are also the foundations for positive growth and wellbeing; those we have with our parents, children and partners. Attachment theory is a theory about relationships, based on the idea that human beings evolved in kinship groups and that human survival was enhanced by the maintenance of secure bonds between parents and children and with members of the wider group [i] (Holmes, 1993). It has been described as the brainchild of two parental figures, John Bowlby and Mary Ainsworth [ii] (Bretherton, 1995). Bowlby[iii] (1969) defined attachment as an enduring affective bond characterized by a tendency to seek and maintain proximity to a specific figure, particularly when under stress. It is an inborn system in the brain that influences and organizes motivational, emotional and memory processes with respect to significant attachment figures. Based on repeated experiences of interaction with an attachment figure, the child forms internal representations of self and of relationships with others[iv] (Bowlby, 1969). Attachment relationships are critical to the infant’s physical and emotional survival and development [v](Wallin, 2007). Ainsworth’s contribution to attachment theory centred on the development of her concept of the ‘secure base’ which created an important foundation for research methodology in child development[vi] (Ainsworth, 1978). [i] Holmes, J. (1993) John Bowlby and Attachment Theory. London: Routledge. [ii] Bretherton, I. (1995). The Origins of Attachment Theory: John Bowlby and Mary Ainsworth. In P. Goldberg, R. Muir, and J. Kerr (Eds), Attachment Theory: social, developmental and clinical perspectives. Hillsdale, New Jersey: Analytic Press [iii] Bowlby, J. (1969, 1973, 1980) Attachment, Separation and Loss (3 Vols). London Routledge [iv] Bowlby, J. OpCit [v] Wallin, D. J. (2007). Attachment in Psychotherapy. New York: Guilford Press. [vi] Ainsworth et al (1978). Patterns of Attachment. New Jersey: Hillsdale. • To raise awareness of the importance of healthy, secure attachment. This will include the dissemination of information to professional and to parents/caregivers. The primary message in this information will be an understanding of why attachment matters for individuals, families and society, as well as the factors that encourage and impede healthy attachment. • To advocate for knowledge of attachment theory and practice to become a fundamental element in the education of all relevant professionals. This will include professionals in health, mental health, and social care service, as well as educational professionals including primary and secondary school teachers. • To engage with a range of carers, educators and health and social care professionals in a way that supports their role in relation to understanding and applying attachment informed thinking and decision making in their clinical and educational practice. • To assist in the advancement of effective attachment-informed practice through the development, support and dissemination of robust research, professional training and CPD, seminars and conferences. • To act as a central point of contact for professionals who are trained and are working in using attachment-related approaches, so as to facilitate sharing of knowledge and expertise. • To deliver a minimum of two annual events focused on promoting attachment. • To advocate for the allocation of research funding to support the development of interventions that can be tailored to particular needs of individuals and groups within society, across the whole island of Ireland. • To work with the Northern Ireland Assembly and the Government of the Republic of Ireland to encourage the consideration of cross-departmental policies and initiatives to promote healthy attachments. We believe that improving the existing understanding of and attitudes towards attachment is essential for improving Ireland’s profile in terms of emotional health and in understanding socially destructive behaviors. We believe that a greater understanding of attachment theory can help to promote social cohesion and better outcomes in terms of physical and emotional health. We believe in supporting parents and families through providing access to knowledge, training and expertise in attachment for professionals. We believe that understanding and supporting positive attachments during all stages of development will deepen our awareness of how physical and emotional health interact and will enhance and help to underpin social policy planning and health strategies that will help individuals and families. To this end we aim to inform government and non-governmental agencies of the benefits of attachment theory as a fundamental theoretical base for social policy. We aim to help government and non-governmental agencies gain a greater awareness of attachment in the context of their work and in terms of policy and planning. IAIA seeks to help support individuals and organisations to gain a greater understanding of this ‘Attachment World’ so as to make positive contributions to our families, work places and the communities we live in. Creating a greater awareness of the importance of relationship is one of our key objectives in IAIA. We are committed to promoting more positive experiences of attachment to enhance our relationships between parents and children, within families and in society generally. We believe that improving the existing understanding of and attitudes towards attachment is essential for influencing the positive development of Ireland’s child and adult health and well-being. We are committed to promoting better experiences of attachment in the Irish population in order to effect positive changes in policy and practice in education, care and health. We believe that it is important that our way of working is both connected and collaborative, reflecting the vision and values we cherish. In working alongside partner organisations, our intentions are to place attachment onto the political agenda and contribute to fundamental policy and legislative changes.
A common and colorful sea urchin has some truly bizarre appendages that seem to move independently from its body, and now scientists know why: It shoots these tiny, venomous jaws into the water to deter predators. These teensy, toothy jaws are called pedicellariae, and when scientists discovered them in the early 1800s, they thought the jaws were parasites because they seemed to move independently from the urchin. Now, researchers find that urchins use their pedicellariae not only to defend themselves when attacked, but also as a warning to fish and other sea creatures to "stay away!" Tripneustes gratilla, otherwise known as the collector urchin, is a widespread species found in shallow waters in the Bahamas, the Indo-Pacific region and even the Red Sea. [Gallery: See Photos of Glorious Sea Urchins] Pedicellariae are found only in echinoderms, particularly sea stars and sea urchins. The type found on collector urchins are known as globiferous, meaning they have a three-pronged jaw and a venom sac at the end of a long stalk. When disturbed, the urchins shoot a cloud of pedicellariae into the water around their bodies. Those that meet their mark sink their tiny, venomous teeth into the predator's skin. Even if a predator fish tears away the structure in its haste to flee, the jaws remain embedded, and the venom sac keeps pumping irritating toxins into the fish's flesh. What Sheppard Brennand and her colleagues discovered was that fish don't have to make direct contact with sea urchins to be shot with pedicellariae. To prompt T. gratilla to shoot off these structures, the researchers poked the sea urchins with forceps in a lab for 30 seconds, to simulate predation. Then, they incorporated pedicellariae into squid snacks and offered them to two species of fish that prey on urchins: the black axil chromis (Chromis atripectoralis) and the stocky anthias (Pseudanthias hypselosoma). In an aquarium setting, the fish ate 50 percent fewer treats containing venomous pedicellariae compared with treats containing no pedicellariae. When the researchers washed the pedicellariae of their venom, the fish readily accepted between 80 percent and 90 percent of the squid snacks embedded with tiny jaws, compared with fewer than 20 percent of the treats if the venom wasn't rinsed. The researchers also tested their squid snacks in the wild at Coffs Harbour Marina, between Sydney and Brisbane, using a GoPro camera to record video of fish behavior around the treats. Again, the fish avoided the pedicellariae-filled food and gravitated toward the clean options. Clearly, pedicellariae were unpalatable, Sheppard Brennand said. Next, the researchers put fish in a tank with two flumes, one of which had a sea urchin about 28 inches (72 centimeters) upstream. When the sea urchins were prodded to release their pedicellariae, the fish tended to avoid being downstream, the researchers found. Fish spent less than half of their time in a flume filled with pedicellariae, compared with 70 percent of their time in flumes with an undisturbed urchin or no urchin at all. "Discovering that the pedicellariae cloud deterred fish was the most exciting finding," Sheppard Brennand said. "We had hypothesized that this might be the case, but until you actually do the research and examine the data, you don't know what the outcome will be." Deterring predators with a long-range defense may save the urchins a lot of wear and tear, since they don't necessarily have to be bitten by every fish that needs to learn to stay away, the researchers wrote. Lots of animals have "pursuit-deterrent" signals like this that don't require contact with predators. Porcupines have their quills, for example, and some species of spider kick off tiny, irritating hairs. Bombardier beetles spray hot, irritating chemicals. And urchins, it seems, have their mobile bite.
As a certain author once conveyed, space is really big. If it seems like astronomers are constantly discovering things never seen before, that’s because the universe is so vast that it contains so many things we’ve never seen before. This time around, astronomers have discovered two supermassive black holes orbiting around each other — the first time that kind of system has been observed in a normal galaxy. The otherwise hidden black holes were revealed when they ripped apart a star right as a telescope decided to look in its direction. It’s generally thought that each large galaxy houses a supermassive black hole at its center, including our own. You might have seen an early episode of the Cosmos reboot which explained that galaxies do merge over time, and that can create two black holes orbiting around each other. In fact, our galaxy — the Milky Way — is projected to eventually merge with its closest neighbor, Andromeda, so it’s safe to assume that our galaxy will experience a double black hole at some point in its lifespan. Using the XMM Newton, an orbiting observatory launched by the ESA back in 1999, a team of astronomers at Peking University happened to notice the black holes ripping apart a star, simply because the observatory was pointed in the direction of the destruction as it was happening. When a star is ripped apart in such a way, it produces a flare of X-rays. Normally, the X-rays linger on for a while after they’ve appeared, but this time around, the astronomers noticed the X-rays greatly subsided in an uncommonly short period of time — which is exactly what would happen if they lingered around a pair of supermassive black holes, rather than just the one. After about two million years, these two black holes will spiral together, merging into one. Aside from it just being fascinating that black holes teamed up to destroy a star, this system (and ones like it discovered hereafter) will teach us about the speed at which galaxies merge. It’s predicted to eventually happen to our own, so it’ll eventually be relevant to our way of life, assuming we live that long. For now, the XMM Newton will continue to look for other black hole teams delivering swift vengeance upon lowly stars.
Output: Standard Output (stdout) Memory limit: 16 megabytes Time limit: 0.2 seconds Your Goal: Add two integers. Two integers a and b will be given on a single line, separated by a single space. You must read these as inputs into your program. Don't use input prompts! Our servers will pretend to be you and try out several number combinations on your program. The server might test your program using any values of a and b which are between -1,000,000,000 and +1,000,000,000. You should print a single integer, the result of a+b, to the output. Note: If you are confused about how input and output work when your program is being marked then try reading this: How to IO in Python. The same principles apply to all the languages we support. Remember that our servers will see your input and output separately, not mixed together like you do when testing in a console window. Sample Input 1 Sample Output 1
Our Larynx Cancer (Throat Cancer) Main Article provides a comprehensive look at the who, what, when and how of Larynx Cancer (Throat Cancer) Definition of Cancer, larynx Cancer, larynx: Cancer of the voice box (the larynx) which is located at the top of the windpipe (trachea). Also called laryngeal cancer or laryngeal carcinoma. Cancer of the larynx occurs most often in people over the age of 55 years. A clear association has been made between smoking, excess alcohol ingestion, and laryngeal cancer. If a patient with laryngeal cancer continues to smoke and drink alcoholic beverages, the likelihood of a cure is diminished, and the risk of developing a second tumor is enhanced. People who stop smoking and drinking can greatly reduce their risk of cancer of the larynx. The larynx is divided into 3 anatomical regions. From top to bottom, they are the supraglottis, the glottis (which contains the vocal cords), and the subglottis. The supraglottic area is rich in lymphatic drainage so up to half of people with supraglottic tumors already have metastases (spread of the tumor) to lymph nodes at the time of diagnosis. The vocal cords are largely devoid of lymphatic vessels so that cancer confined to the vocal cords rarely, if ever, presents with involved lymph nodes. Subglottic tumors are quite rare but may metastasize. Painless hoarseness can be a symptom of cancer of the larynx. The larynx can be examined with a viewing tube called a laryngoscope. Cancer of the larynx is usually treated with radiation therapy or surgery. Chemotherapy can also be used for cancers that have spread. Last Editorial Review: 5/13/2016 Back to MedTerms online medical dictionary A-Z List Need help identifying pills and medications?
An album of images and a simple text reveal that birds’ feathers are far more versatile than one might expect. Comparing feathers to familiar objects, Stewart reveals that birds use them in surprising ways. Her two-level text is headlined with a comparison and includes a short paragraph of explanation. Laid out like a scrapbook, her words share a page or spread with accurate and appealing watercolor images of a bird (identified by species and location), the everyday object in question and the feather. From backyard blue jays and cardinals to exotic manakins and peacocks, the 16 birds used as examples come from all over. The rosy-faced lovebird in Namibia carries nesting material in its tail feathers, like a forklift. For the Alaskan winter, a willow ptarmigan grows feathers on its feet that serve as snowshoes. In Mongolia, a Pallas’ sandgrouse uses his spongelike belly feathers to soak up water to bring to his nestlings. On a concluding spread, text and illustrations together provide an example of one possible system of feather classification. Sepia-toned endpapers show some of the feathers described. Other than a note about Birdwatching magazine, the author doesn’t indicate her sources, but considerable research by both author and illustrator is evident. The combination of thoughtful approach and careful crafting makes this an excellent resource for early nature study. (Informational picture book. 5-9)
What is nervous system? What are the functions and parts of human nervous system and definition. Laughing, talking, thinking , reading, crying and walking are examples of behavior. You control these behaviors consciously. Other movements such as the movement of the stomach muscle, diapragm and throat are controlled by your body automatically. You breathe and swallow without any concious effort. Your eyelids also move without you thinking about them. Anything that causes a reaction is a stimulus. How a person reacts to a stimulus is a response. If you touch a hot object with your hand, you pull your hand away immediately. The hot object is a stimulus. Pulling your hand away is the response. All of these behaviors are controlled and regulated by the nervous system and the endocrine system. The nervous system includes the brain, spinal cord and nerves. Nerve cells run throughout the body and carry messages about your environment to your brain. Messages from your brain travel to all parts of your body. Receptors, nerves and effectors are three basic structures that involved in the functioning of the nervous system. Receptors are specialized neurons that are sensitiye to certain changes brought about by physical forces like heat, pain, pressure of touch, light and so on. Stimulation of a receptor causes messages or impulses. These impulses eventually reach an effector. An effector may be a gland or a muscle. Any factor that causes a receptor to initiate an impulse is called a stimulus for example ; light, heat, cold and sound. The nervous system is divided into two parts: 1. The central nervous system: This includes the brain and spinal cord. 2. Peripheral nervous system : The nerves which connect the body to the central nervous system These nerves carry messages between the central nervous system and the rest of the body.
The vagus nerve is one of 12 cranial nerves. It is the longest of the cranial nerves, extending from the brainstem to the abdomen by way of multiple organs including the heart, esophagus, and lungs. Also known as cranial nerve X, the vagus forms part of the involuntary nervous system and commands unconscious body procedures, such as keeping the heart rate constant and controlling food digestion. Electrical stimulation of the vagus nerve, called vagus nerve stimulation (VNS), is sometimes used to treat people with epilepsy or depression. The vagus nerve is involved in one of the most common causes of fainting, called vasovagal syncope. This is an overreaction of the body to certain stimuli, like the sight of blood, which involves the stimulation of the vagus nerve. This stimulation causes a drop in blood pressure and heart rate. Less blood flows to brain, resulting in loss of consciousness. In most cases, vasovagal syncope does not require treatment.
There are many different definitions of “what is an emulator”? or “what is the function of an emulator”?. I will list a few of the definitions,and hope they may answer your question. 1 – An emulator provides game enthusiasts with the opportunity to play games from other gaming platforms,an emulator also allows gamers to play games from older systems,or that may no longer exist. 2 – Emulation refers to the ability of a computer program or electronic device to imitate another program or device. 3 – A console emulator is a software program that duplicates a computer or gaming console to emulate a video game,so that it acts or imitates like the original. For an example if you want to play a game from the Nintendo or Sega gaming platform,you must download an emulator for that said game.Each game has an individual emulator. 4 – Gamers can use emulators to modify existing games – ie translate games into different languages. 5 – An emulator,provides conversion software that will enable a game to run on a computer or another system or platform for which it was not originally designed for. 6 – An emulator is a software program that can imitate the original hardware environment of a gaming console.This means that an emulator will “emulate” a gaming console’s hardware capabilities and so game software that was developed for specific hardware can be run on your computer via the emulator You can view further information on emulators at Wikipedia.
Back Locked? Blame It on to the Facet Joints. THE FACET JOINTS These are the junctions formed where the vertebrae notch together at the back of the spine. Each motion segment has two facet joints forming part of the back compartment. They flank the back corners of each disc, across the Gulf of the vertebral canal. Neighbouring vertebrae contribute two opposing surfaces to make a pair of facet joints. Two notches of the bone project up from the lower vertebral ring interfacing with two projecting down from the upper vertebral ring. Thus, two inter notching junctions are made.The facet joints do not bear a lot of weight unless the disc is thin or the lumbar lordosis extreme, but they suffer constant wear and tear in controlling the movement of their vertebrae. To protect the joint surfaces a properly functioning joint needs to exist where the two bones meet.The most capable and resilient joints in the body are synovial joints, and all of them-whether in the fingers, knees or facet joints-share common properties. They have extremely strong joint capsules which knit two sides of the joint together. The capsules have a well-weird nervous network to make the joint highly sensitive and they also have a prolific blood supply. The inner lining of the capsules (called the synovial membrane) floods the joint with synovial fluid which both dampens impact and lubricates the working surfaces. The facet joint capsules are usually strong. With bending forward they provide nearly as much soft-tissue restraint as then discs in glueing the spinal segments together.Researchers have removed the discs from cadavers in a laboratory and shown that almost twice body weight can be suspended by the facet capsules alone. Thus they are more than simple joint capsules: they are more like ligaments and for this reason, they take the name ‘capsular ligaments’. Each facet joint has a smooth-interfacing congruency of its opposing joint surfaces. These fit snugly together like two cupped palms, the valleys of one side matching the hills on the other. The surfaces of the opposing bones are covered by hyaline cartilage which is a smooth semi-compliant buffer with a rich mother-of-pearl sheen.Cartilage allows the bones to skid over one another and has the yielding consistency of dense plastic which allows it to deform imperceptibly whenever the bones make contact. The direct contact also squeezes fluid out, but when the pressure releases and the cartilage un-dints, it sucks water back in. In this way, the bloodless cartilage keeps itself healthy by creating a ‘circulation’ to pull in nutrients and expel waste products.The slippery cartilage interfaces are lubricated by synovial fluid just as tears flush the eyes and this synovial fluid has astonishing qualities of lightness and slipperiness. The joint capsule keeps the fluid contained under pressure that springs the joint surfaces apart and softens the impact of bone on bone. It also means the joint operates on a cushion of fluid (in a hydraulic sack) which streamlines movement and takes out the jerkiness.Synovial fluid also cleanses the joint space by clearing away cartilage particles eroded off the main bed during activity. The synovial membrane liberates large cartilage-eating cells into the tide of floating debris. These cells surround each particle, like an amoeba trapping its food, and dissolve it. It is essential cleaning-up work. Without it the joints would slit up with cartilaginous grit acting like a pot-scourer, grinding away the joint surfaces until nothing was left. The chain of facet joints down the spine provides a primitive interlinking hook-up which notches the spinal segments together. The upper facet surfaces are convex and the lower ones concave. This allows the upper vertebrae to lock in place when its convex pillars fit snugly into the concave cups of the ones below.If the facets were not there the vertebrae could roll around on their discs and the neurocentral core could tie itself in knots like a cartoon character of an India-rubber man. However, the definite front-back alignment of the lumbar facets means our only generous movement of the low back is bending forward. Their configuration means the vertebrae only move forward and back, like the wheels of a train moving down the track, never twisting left or right (although they can side-bend a little). This lets us lower the rest of our body down, like a stooping mechanical crane, putting our hands and face at the right height to be useful. There is a good reason for the facets otherwise restricting movement: it keeps things from wearing out. The twisting action in the low back is especially hard on the discs. It challenges the inherent weakness of their walls, especially if there is lifting as well. With only every alternate layer of the onion-skin disc wall offering restraint (while the fibres of the other half go on the slack offering no help), repeated twisting can be destructive.
After children reach one year of age, accidental injuries are the largest cause of death in the United States (National Center for Health Statistics (NCHS) Vital Statistics System, 2001; National Safety Council, 2001). Therefore, reducing injuries when working with this age group is a major concern. A longitudinal study of more than 1,200 children followed from birth through first grade found that children who spend more time in child care have a slightly reduced risk of injury compared with children spending more time in their own homes (Schwebel, Brezausek, & Belsky, 2006). Additionally, the majority of injuries (87%) that do occur in child care are minor. Only 1% are considered severe. However, because so many children in the United States are in child care, there are still a large number of children accidentally injured in these settings each year. For example, in one year, 31,000 children, 4 years old and younger were treated in U.S. hospital emergency rooms as a result of injuries sustained in child care. At least 56 children died in child care during the 1990s (U.S. Consumer Product Safety Commission, 1999). The majority of deaths were due to suffocation from nursery equipment or soft bedding. Most injuries (74%) in early childhood settings are due to playground accidents. It is important to be continually alert for safety dangers in the environment. A large-scale national study conducted by the U.S. Consumer Product Safety Commission (CPSC) found that two-thirds of the childcare settings they examined had at least one safety hazard. The CPSC warns that there is a potential for children being injured, even seriously hurt, in these environments. The study looked at cribs, safety gates, window blind cords, drawstrings in children’s clothing, recalled children’s products, and ground coverings (U.S. Consumer Product Safety Commission, 1999). Listed below are some of the most important environmental concerns in keeping children safe: - All materials should meet the standards of the Consumer Product Safety Commission (CPSC). - To protect against falls, stairways, windows, and elevated surfaces should meet the American Society for Testing and Materials (ASTM). - Children should be protected from electrical outlets with specially designed outlets or safety caps. - Electrical cords should not be within reach of children. - Emergency phone numbers need to be posted near each telephone (poison control, fire department, emergency contact numbers for parents and others, and the child’s doctor). - Make sure there are adequate fall surfaces under both indoor and outdoor equipment and that toys are not left in fall zones. Continually examine the environment for tripping hazards. - To prevent poisoning, make sure all cleaning supplies and medications are in locked cupboards, there are no poisonous plants on the premises, and that children do not have access to purses or offices where adults might store personal medication. - Toys need to be safe by being age and developmentally appropriate for the group. For example, all toys for infants and toddlers or children who are still mouthing toys need to be choke resistant. They also need to be lead free and nontoxic. Finally, one must examine toys to make sure that they cannot lead to strangulation. - Buckets and tubs containing water need to be closely supervised and emptied when not in use since small amounts of water can be a drowning hazard for young children. - All equipment, including railings on stairs, need to be examined for possible strangulation risk. Window blind cords and drawstrings on children’s clothing can also create safety issues. - A daily safety check and maintenance is critical to keep equipment and the child’s environment safe. - Children need to be safe from other children who are aggressive. See Chapter for more information on this subject. Even if the environment meets safety guidelines, supervision is critical in ensuring child safety. The majority of injuries (60%) that occur in early childhood settings are due to child behavior rather than environmental causes (Alkon et al., 1999); for example, a child tripping and falling, colliding with objects, or one child pushing another as they go down a set of stairs. Most states have established child/staff ratios to assist in providing adequate supervision. It is critical that programs maintain these ratios. In addition, it is important that adults actively monitor children. Many programs require staff to maintain visual contact with children as they play. Low classroom dividers can help children to feel a sense of privacy, while still allowing adults to adequately supervise children. Although severe injuries are rare in early childhood settings, it is important to be alert to and to immediately correct safety dangers. It is also important to assure children remain safe through adequate supervision. © ______ 2010, Merrill, an imprint of Pearson Education Inc. Used by permission. All rights reserved. The reproduction, duplication, or distribution of this material by any means including but not limited to email and blogs is strictly prohibited without the explicit permission of the publisher.
This test follows Glencoe McGraw-Hill's Math 7th Grade Accelerated Textbook and this test would accompany Chapter 1. Everything is able to be changed as soon as you choose 'enable editing'. Some of you may want to change the point values or add/delete questions. The following topics are covered: Lesson 1: A Plan for Problem-Solving Lesson 2: Words and Expressions Lesson 3: Variables and Expressions Lesson 4: Properties of Numbers Lesson 5: Problem-Solving Strategies Lesson 6: Ordered Pairs and Relations Lesson 7: Words, Equations, Tables and Graphs Note: This item will be downloaded as a Microsoft Word document in order for the equations to appear correctly. THE THUMBNAILS OF THESE IMAGES ARE SKEWED ONLY BECAUSE OF THE FORMATTING CONVERSION TO TPT Good luck and happy teaching!
Scientists at Arizona State University, or ASU, have discovered that a meteorite, which exploded in a blazing fireball over California last year, contains ingredients that may hold clues to the evolution of life on Earth. A team of scientists, led by Sandra Pizzarello, a research professor in ASU's Department of Chemistry and Biochemistry, found that the Sutter’s Mill meteorite, which dropped to Earth over California in April 2012, contains never-seen-before organic molecules. “The analyses of meteorites never cease to surprise you ... and make you wonder,” Pizzarello said, in a statement. “This is a meteorite whose organics had been found altered by heat and of little appeal for bio- or prebiotic chemistry, yet the very Solar System processes that lead to its alteration seem also to have brought about novel and complex molecules of definite prebiotic interest such as polyethers.” The findings suggest that the existence of a greater number of extraterrestrial organic molecules, which could have been important in molecular evolution and life itself, is possible, according to the study recently published in the Proceedings of the National Academy of Sciences. Pizzarello and her team hydrothermally treated fragments of the meteorite to detect the compounds. The hydrothermal conditions of the experiments, which mimic early Earth settings (a proximity to volcanic activity and impact craters), released a complex mixture of oxygen-rich compounds. Scientists believe that these compounds could be the result of oxidative processes that occurred in the meteorite. According to the researchers, the latest discovery is an addition to the inventory of organic compounds produced in extraterrestrial environments, promoting the discourse that their delivery to prehistoric Earth by comets and meteorites might have aided the molecular evolution that preceded the origins of life. Because meteorites can be rich in organic compounds, their composition “has always been seen as an indication that the precursors to the evolution that led to the origins of life could have come from the extraterrestrial material of meteorites,” Space.com quoted Pizzarello as saying. “Since the origins of life are utterly unknown, the idea has its merits.”
Children with many different types of disabilities may have difficulty talking, including those with cerebral palsy, brain injuries, hearing impairments and cognitive disabilities. Children who can’t talk still need ways to communicate, of course. Some nonverbal children learn American Sign Language or some other system of signing. Others use augmentative communication devices. The type of device used depends on the specific needs and abilities of the individual child. Object symbols are small objects that represent specific things or activities. For instance, a tiny school bus may represent going to school or a small figurine of a dog may represent the family pet. Children select the object that represents what they want to communicate. Photos or Drawings Photos or drawings work much like object symbols but can be easier to assemble and carry around. The photos and drawings represent objects, actions, activities or feelings, and children select the image that represents what they want to communicate. Communication Boards or Books Communication boards or books are displays or books consisting of photos, drawings, symbols or words that children can use to communicate. Children point to the image that represents what they want to say. Some communication boards or books include many images, while others include only a few. Children usually point to the image that represents what they want to communicate. If children have trouble using their hands, though, parents, teachers or other adults can point to the images one by one and children can nod or otherwise indicate the image they wish to select. Easily portable boards and books usually work best; some people affix communication boards to wheelchairs so they are easily accessible to wheelchair users. Alphabet Boards or Typing Devices Alphabet boards resemble communication boards but have letters instead of pictures on them. Some have letters arranged in alphabetical order while others use a standard keyboard format. Children point to the letters to spell out words in order to communicate. Of course, alphabet boards only work for children who can spell well enough to communicate that way. Typing devices work like alphabet boards except they print out or display the letters children select. Children can even use an ordinary laptop as a typing device, though young children might do better with something sturdier than a laptop. Speech Generating Devices These electronic devices play recorded messages when children press buttons or switches. Some devices have only one or two buttons or switches, while others have more. Recorded messages may be as simple as “yes” and “no,” or they may be longer, like “hello, my name is Susan or “I need to use the bathroom.” Children usually activate these devices with their hands or fingers, but they can activate devices in other ways if they have difficulty using their hands. - George Doyle/Stockbyte/Getty Images
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia. Anemia of chronic disease is anemia that is found in people with certain long-term (chronic) medical conditions. See also: Anemia Anemia of inflammation Anemia is a lower-than-normal number of red blood cells in the blood. Certain chronic infections, inflammatory diseases, and other illnesses can affect the body's ability to produce red blood cells. Conditions that can lead to anemia of chronic disease include: Anemia of chronic disease is often mild. You may not notice symptoms of anemia. If they occur, smptoms may include: The doctor will perform a physical examination. Because anemia may be the first symptom of a serious illness, determining its cause is very important. Tests that may be done to diagnose anemia or rule out other causes include: Anemia is often mild enough that it does not need treatment. It will likely get better when the disease that is causing it is treated. The condition is rarely severe enough to need a blood transfusion. Iron supplements may sometimes be used, but only for patients whose iron levels are low. Taking iron pills when your body does not need it can lead to serious medical problems. Always talk with your health care provider first. For some conditions, such as chronic kidney disease, medicine called erythropoietin may be given. It stimulates your bone marrow to make more red blood cells. The anemia will improve when the disease that is causing it is successfully treated. Discomfort from symptoms is the main complication in most cases. Anemia may lead to a higher risk of death in patients with heart failure. Call for an appointment with your health care provider if you have a chronic disorder and you develop symptoms of anemia. Gardner LB, Benz Jr EJ. Anemia of chronic diseases. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 37.
Geometry is the math related to proportions, or size, shape and position, so practical applications of geometry come in measurement and spatial reasoning. Everything from wrapping a gift to designing a backyard landscape is governed by geometry.Continue Reading People commonly use geometry area problems when working on their homes. Area problems help them decide how much carpet or paint to buy and even which furniture will work in a given space. Likewise, decorating a room or an outdoor area takes spatial reasoning and an arrangement of geometric shapes. Volume problems are another daily-life use of geometry. People use volume equations to determine how much water goes in a fish tank, how much sand is needed for a sandbox or even how much soil is needed for a window garden. Elements of plane geometry, or the relationship of two-dimensional shapes on a flat surface, also have their significance in real life. For instance, pool players have to determine angles when shooting the balls across the table. Likewise, angles and symmetry are very important for hairstyling. Hair styles should complement a client's face shape. Likewise, when cutting the hair, hairstylists need to cut at certain angles so that the hair falls in the desired shape. For symmetry, hair actually has to be cut at different lengths to conform to the shape of the client's head. Finally, many professions such as engineering, interior design, landscape architecture and even furniture moving use geometry as a basis for their work.Learn more about Geometry
How art reflects the society Write a 700- to 1,050-word paper on how art reflects the society in” rel=”nofollow”>in which it was made that responds to the followin” rel=”nofollow”>ing:1.What image of America was communicated by the in” rel=”nofollow”>innovations and buildin” rel=”nofollow”>ings presented at the 1883 Chicago’s World Fair? 2.How was this image communicated? -How and why was the art produced by the Ashcan School different from that of the Gilded Age? 3.To what changes in” rel=”nofollow”>in social history were artists reactin” rel=”nofollow”>ing? -How is art a reflection of society? Explain” rel=”nofollow”>in with at least two examples to illustrate the relationship between art and society. These two examples may be from the text or of your own selection. Discuss the subject or theme of your selected works.
The population pyramid for Mexico in 2010 is shown below: What does this pyramid tell us about Mexico’s population and possible future trends? The number of babies born during the last 20 years has been more or less equal for each 5-year period. This is despite a higher number of females in the age-bearing categories (15-45). These two statements, taken together, must imply that both birth rates (number of births/1,000 people) and fertility rates (number of children per female of child-bearing age) have fallen and continue to fall. There are numerous implications for a population with a declining number of babies. Perhaps the most obvious is that fewer school places will be required in ten years time than are currently needed. In Mexico’s case, it is unlikely that school buildings will be closed (at least not in the short to mid-term) since many government-run schools currently house two independent school populations, one attending classes every morning, and the other attending classes in the afternoons. The decline in babies also means that the average age of Mexico’s population continues to rise. The median age of Mexico’s 112.3 million inhabitants is now 26 years (i.e. half the population is older than 26 years, the other half is 26 years or younger). Several chapters of Geo-Mexico: the geography and dynamics of modern Mexico discuss additional insights into Mexico’s population dynamics and trends, and their implications for future development. An earlier post here includes a link to a pdf file showing Mexico’s population pyramid in 1990, and the predicted pyramid for 2050. The 2050 pyramid shows just how fast Mexico’s population will age if present trends continue.
Lesson Plan for World Geography/World Cultures (90 minutes) Critical Thinking Skills Grade 9 Social Studies Prepare copies of the handout List of Various Groups (one copy per group) National Geography Magazines (You can borrow copies from the public library. Let your library know that any issue is fine, a mix of issues would be best.) Open Class with Discussion: What is culture? Ask: Who can define culture? (Get some answers.) Direct students to brainstorm examples. Write student answers on the board Ask: What goes into culture? (Get some answers. Help them if they need it by suggesting clothing, music, government.) Say: School is a culture. From the list we made, how does school culture fit some of the list - in particular, clothing, music, and government? (Get some answers.) Hand out List of Various Groups Direct each student to circle the groups on this list to which they belong. Group Activity: About 10 minutes Tell students to take their list with them, and to move into groups of 4 students (or less.) Their job is to compare their individual lists with other people in their group. Then, they are to identify three things that everyone in their group has in common on their individual lists. At the bottom of each paper, student will write down the name of the 3 groups they have in common like this. Put this list marked a-e on the overhead. b) Purposes of that group (why it is in existence) c) The beliefs of that group d) The rules of the group e) Is membership voluntary or involuntary? Give them some time. Then, ask each group to share one of the three things they had in common with the class, and have them state the answer(s) they chose for a-e above. It is okay if another small group presents the same selection (family, school, etc.) As groups present, start throwing in monkey wrenches. School, for example: Your students may say school is involuntary and that they have to go to school. Throw in a monkey wrench. Say: What about college? What if you're 17 years old? Family, for example: Throw in a monkey wrench. Ask: Does every family believe that? Do not challenge everything they say, but occasionally throw in a monkey wrench to keep them thinking. Transition: Once every group has presented one thing they had in common, have them turn in their individual work and return to their desks. Class Activity: Ask your class if anyone can define the following terms. (You may be surprised.) Assign two students to look up one definition each in the dictionary. Compare dictionary definition to the class definition of each word. Modify the class definition if necessary. What is homogeneous? (in common, all the same) What is heterogeneous? (all different) Tell students to listen to the instructions first, and then act. Say: Here's what I want you to do. Every individual will go and get a National Geographic magazine. Select a culture, any culture, so long as it is not one of your own. List 3 physical characteristics the culture you selected has in common. Find 4 cultural ideas that the people have in common. After they have each returned to their desk, and have had a chance to leaf through a magazine, write on the chalkboard or overhead direction #2-4 above. If time permits, ask for a volunteer to share a culture they discovered and state the 3 physical or 4 cultural ideas that the people have in common. Conclude activity by asking your opening question again. Ask: So, who can tell me what culture is? (Get some answers. Make sure they are right ones.)
Although rocks of no great age, geologically speaking, outcrop over much of the surface of Italy, almost every geological period is represented somewhere in the country. A great variety of different types of rock is also to be found, and it is the nature of these rocks and the way in which they have been formed and now outcrop rather than their age, that help to account for present land forms. Lower Paleozoic rocks appear at the surface only in a few localities, being most extensive in the southern half of Sardinia, where they include limestones and are highly folded, but old rocks occur also in the Alps. The Carboniferous rocks of Italy differ markedly from those further north in Europe in having very few coal deposits, because conditions were less favourable for their formation. During Carboniferous and Permian times Italy, like areas further north, was affected by the Hercynian earth movements, and mountains were formed in the same general area that in Tertiary times became the Alps. Hercynian massifs were also formed in Calabria and northeast Sicily as well as in Sardinia. After the Hercynian earth movements in the latter part of the Paleozoic era the general area of Italy was covered by the sea for long periods and on account of the absence of land nearby, limestones are therefore typical of Permian, as well as of the Mesozoic era (Triassic, Jurassic and Cretaceous). Most of Italy’s limestone areas are of Jurassic or Cretaceous origin, as in the limestone Alps and Pre-Alps of Lombardy and Veneto, the Central Apennines and the mountains and hill country of Apulia. Towards the end of the Mesozoic era and during the Tertiary era before the great period of Alpine mountain building, gravels, sands and clays as well as limestones and marls were being deposited, and Eocene, Oligocene and Miocene sandstones and clays form a large proportion of the present Northern and Southern Apennines and Sicily, while the earlier clays of late Cretaceous times (argille scagliose) are characteristic particularly of the Northern Apennines. Italy to a large extent owes its present general form and outstanding physical features to the mountain building that took place in the Miocene period and led to the formation of the Alps and Apennines structurally roughly as they are today, though the ranges have of course been greatly reduced by erosion and later uplifted since their original formation. Intrusive rocks were formed widely and volcanic activity was widespread. Existing sedimentary rocks were drastically folded and faulted and in many areas were thrust laterally great distances, with older strata in some places finally ending up resting upon younger strata. In the north-west or crystalline Alps the thrust was roughly from south to north while in the Apennines it was from the Tyrrhenian side towards the Adriatic side. The direction of fold lines was often determined by the distribution of pre-existing resistant blocks. The Tyrrhenian and Adriatic areas formed troughs. The formation of nappes is characteristic of both the Italian Alps and the Northern Apennines, but although the process also occurred further south in the Peninsula, the result of earth movements here was more to block fault the widespread limestones, leaving upstanding blocks and intervening basins. The mountains of the northern half of Italy tend to have such a complicated evolution and consist of so many different types of rock that present relief bears little relationship to underlying structure and rock types. In the southern half of the country, on the other hand, where tectonic relief is common, there is clearly a closer relationship, as in the limestone areas of the Central Apennines and Apulia, and in the crystalline massifs of Calabria. Towards the end of Tertiary times, after the termination of the more drastic Alpine earth movements, Italy had already assumed very broadly its present shape. What are now the mountain areas then stood above the sea but, except in Sardinia, most areas that are now hill country and plain had not yet been formed. During the Pliocene period, gravels, sands and clays were deposited around the coasts of the land of that time and also in numerous small basins within the Peninsula itself, and Pliocene deposits are today found flanking both sides of the Apennines in many places, reaching as high as several hundred metres, and forming hill country. One final brief but extremely important phase in the evolution of Italy has followed the Pliocene, the glacial period in the Pleistocene. During this period there were at least four main onsets of glaciation and these profoundly influenced the land forms of the Italian Alps and also affected limited high areas in many parts of the Apennines. Glaciers from the Alps spread far into the lowland to the south and during and after the glacial period an enormous amount of material was deposited in the North Italian Lowland. When sea level was at its lowest during the last glaciation what is now roughly the northern half of the Adriatic was land, and almost everywhere along the coasts of the Peninsula and Islands the land also extended further than it does now. The North Italian Lowland, therefore, is Quaternary or recent, and along the coasts of the rest of Italy there are also many smaller deposits of this time, some of the most recent actually at sea level, others at certain commonly found moderate elevations above sea level.
About the MCAT > MCAT Biology Table of Contents Prokaryotic Cells are simple organisms that contain no membrane bound organelles. Prokaryotes reproduce solely through asexual reproduction, in which offspring is identical to the single parent. Viruses are also included in this section, and although they are currently not considered true life forms as they cannot produce without a parasitic relationship with a host organism. See Eukaryotic Cells Eukaryotic Cells contain a nucleus and other organelles and are surrounded by a cell membrane. The main differentiator between Eukaryotic cells and Prokaryotic cells is the presence of a nucleus, where all of the cell’s DNA is encapsulated within a membrane, within the cell’s cytoplasm. The nucleus and other organelles are only found in a eukaryotic cell; in prokaryotic cells, the DNA is suspended freely in the cell’s cytoplasm, and no membrane bound organelles exist. In this section, the biological nomenclature and processes of eukaryotic cells will be discussed in depth. Cellular Organelles perform all of the vital functions of a cell, such as energy creation, DNA replication, toxin and waste removal, etc. Some organelles are unique to only plant cell or only to animal cells. Organelles found in animals are the cell membrane, endoplasmic reticulum (both smooth and rough), the Golgi complex, proteins, lysosomes, centrioles, micro-bodies, cytoskeleton, microfilaments, microtubules, intermediate filaments, and the mitochondria. The organelles of both animal and plant cells are discussed in this section. Enzymes are biological proteins that serve as a catalysts for various biological processes, such as muscle contraction, digestion, and fat storage to name a few. It is important to note that enzymes are there only to speed up reactions, and will not alter its outcome in any other way. Enzymes typically do this by lowering the activation energy required for the reaction to occur. Since less energy is required, it is easier to get the ball (the reaction) rolling, so to speak. Everything you may need to know about enzymes and their functions for the MCAT will be covered in this section. Cellular Respiration consists of many different metabolic actions in which the cells of organisms convert chemical energy from various nutrients, such as fats and carbohydrates, into adenosine triphosphate (ATP), and produce waste products. This process is the basic requirement for cellular function, because when cellular respiration is disrupted, the cell will die if respiration is not restored. This section describes the energy cycle beginning at the process of photosynthesis to describe how organisms are able to obtain the energy necessary to support life. This section will discuss the various energy containing molecules, ATP and ADP synthesis and processes, NAD+ and FAD synthesis and processes, glycolysis, fermentation, cellular respiration, the Krebs cycle, and the electron transport chain. See DNA and RNA DNA and RNA contain the genetic instructions for the coding of proteins that performs the functions of all modern living organisms. It is essential to the life processes of all known complex organisms, because it is so versatile in encoding vast numbers of unique genetic instructions that makes the diversity of Earth’s ecosystems possible. However, in order for DNA to be useful to complex organisms, a process evolved to allow for the replication of complex DNA molecules. In this section, DNA, RNA, replication and transcription will be discussed in depth. Ribosomes are responsible for protein synthesis. DNA and RNA determine what, how and when something is produced from the ribosome. Translation is a process where the ribosome determines what instructions are being received by a mRNA (messenger RNA) strand using tRNA (translator RNA) fragments. From this information the ribosome creates polypeptide. Translation is further broken down into three steps, initiation, elongation, and termination, which are discussed in depth in this section. Finally, there are post translation modifications, which are either specifically performed by your body, or are created as a result of an abnormal spontaneous modification, known as a mutation. Ribosomes, translation, and modification will be discussed in depth in this section. Mitosis is the process by which a cell, after replicating its chromosomes, separates the chromosomes into two separate, identical sets of chromosomes, each in its own nucleus. By this process, the cells are able to produce two new nuclei, which is needed for the next phase, which involves the formation of a new cell. The process of forming a new cell after mitosis is completed is called cytokinesis, which involves separating a cell into two new cells, and splitting the cytoplasm and all of its organelles roughly equally between the two. Mitosis and all of its phases will be discussed in detail in this section. Meiosis is a type of cell division that is necessary for the sexual reproduction of Eukaryotes. This type of cell division produces cells called gametes or spores. In many organisms, i.e. plants and animals, gametes are called eggs and sperm. Meiosis differs with normal mitosis in two different aspects. The first difference is that recombination in meiosis shuffles the two chromosomes in each pair, where one is received from each parent, producing chromosomes with new genetic combinations in every gamete made. In mitosis, chromosomes produced are identical to to those in the parent cell. The second difference is that the chromosome count in meiosis produces four genetically unique cells, each with half the number of chromosomes as the parent. In mitosis, two genetically identical cells are produced, with the same number of chromosomes as the parent cell. The process of Meiosis is described in depth in this section. Mendelian Genetics is based off the studies of 19th century Austrian Monk Gregor Mendel. His studies essentially denoted a set of laws of inheritance determined through true breeding of peas and other plants at his monastery. True breeding refers to the fact that the offspring have the same traits as the parents. An example of his work is the Law of Segregation, in which 1) Genes exist in alternate forms called alleles, 2) Organisms must have 2 alleles for each gene, one from each parent, 3) Two alleles segregate during meiosis resulting in gametes with one allele, and 4) If two alleles are different than only one will be fully expressed. This is called dominance and recessiveness. If both alleles are the same then the expression is considered homozygous and if both alleles are different the expression is considered heterozygous. In this section, Mendel’s studies and everything you need to know about genetic inheritance for the MCAT will be discussed in detail. The Human Body is comprised of many systems that worked symbiotically together in order to maintain homeostasis. These body systems, while having many unique functions also have many commonalities that should be understood in order to be successful on the MCAT. The MCAT covers all of the major human body systems such as: Body Systems List When trying to learn the human body systems try to build bridges between the concepts in microbiology also. These topics will often be linked with questions on the MCAT and are more interconnected than they seem at first. Evolution is the process by which organisms adapt and change to their environment. This process takes many generations of genetic mutations and natural selection to show substantial differences between an organism and its ancestors. Evolution itself is a law, organisms will always change over time, the theory of evolution is a different concept. The processes involved with evolution, evidence supporting evolution, and the theories developed around the law of evolution will be discussed in this section.
Brute force attack is one of the oldest hacking methods, yet still one of the most popular and most successful ones. With computers and technologies evolving as fast as they are, bruteforce attacking is now fairly easy to run and more difficult to protect against. Brute force attack definition So, what is brute force exactly? Brute force definition can be given as such — it is a type of cryptanalytic attack that uses a simple trial and error, or guessing method. In other words — a criminal gains access to a user’s account by guessing the login credentials. Sometimes, brute force attacks are still done by hand, meaning that there’s an actual person sitting in some basement and playing a guessing game with your credentials. But, more often than not these days, the hackers use a brute force algorithm, or brute force password cracker, which is, basically, a bot that submits infinite variations of username/password combination and notifies the hacker when it gets in. What is bruteforce attack with examples Brute force has been around ever since coding was invented. Naturally, the public’s been informed about some high profile attacks over the years. Though we can safely assume we do not know about a lot of the ones in the past and ongoing break-ins. The most well-known brute force examples are: - the 2016 Alibaba attack, when millions of accounts were affected; - 2018 Magento break-in that resulted in a thousand admin panels compromised; - another rather recent example occurred in Northern Ireland, where several accounts of parliament members were compromised; - and our favorite — in early 2018 it turned out that Firefox master password is very easy to crack with brute force, which means millions of user accounts might have been compromised over the years it’s been widely used. So, how does a brute force attack work exactly? As we’ve already established, brute force hacking implies that someone is trying numerous combinations of username and password, again and again, and again, until they gain the desired access. So let’s say a username is as simple as “admin” and doesn’t take too much effort to guess (we bet that’s the first one any hacker tries). The password is a whole other story. Usually, a password requires at least 8 alphanumeric characters. There are 26 letters, if the password is lowercase and letters only (which it rarely is), so it makes for 26 possibilities for one character of the password. We can double that, because most passwords are case-sensitive. So it makes 52 possibilities for one character of a password. Add to that 10 digits and, for example, 5 special characters, and you get 67, which roughly makes 406 trillion combinations for the whole 8 characters alphanumeric password. \| Read also: How to Choose and Use Strong Passwords How fast can a password be cracked How long does a brute force attack take? We have 406 trillion combinations. Seams like it will take centuries to crack, right? The answer is yes, if the bot attempts a thousand combinations per second. But the technologies evolve, remember? So, taking that into consideration, how fast can a random password be cracked? There are computers that can do a hundred billion guesses per second and get the correct password in a few hours. There are even super computers that can do a hundred trillion guesses per second, it will take them a couple of minutes to guess the correct combination. And that’s without assuming the correct combination is the 10th, or even the 110th one in the row. Brute force attack types Up to this point, we were assuming the hacker has to guess each and every character of the password. But that’s not always the case. A dictionary attack implies that a hacker has a list of commonly used passwords (password dictionary) and simply tries them all until he finds the correct one. If your password is “password”, “qwerty” or “12345678”, we have bad news for you — it will be cracked in mere seconds. Reverse brute force attacks As the name suggests, this type of attack uses a reverse approach. A hacker tries multiple usernames against one common password, like the already mentioned “password”, until they find the correct combination. Credential Stuffing (Credential recycling) A lot of people use the same username-password combination for different accounts, for the sake of simplicity and to make sure they always remember the password. These people make the hackers’ lives too easy, if you ask us. This type of brute force attack works wonders if the attacker already has access to one of the victim’s accounts, all they have to do is use the same credentials for another service. Exhaustive key search This type of attack we’ve described in detail above. The attacker uses a computer to try every combination possible until the right one is found. Modern computers can complete the task in minutes. Brute force attack prevention It might seem like there’s no way to protect your data from modern hackers and their super-computers. But there are ways to do that, and they are rather simple. The first step of brute force protection is applying common sense. Just stop making it too easy for the hackers. If now you are asking yourself — “How safe is my password?”, we say — good question. Let’s see. If your password is long, combines not only letters, but numbers and special symbols as well, if it is different for every account and does not use any info that can easily be found online (your mother’s maiden name, the Uni you went to, the cat’s name etc.), you are on the safe side! Add to that 2-factor authentication whenever possible, and you can relax, cracking your account is close to impossible. If you own a service or website and want to apply brute force attack protection for your users it’s a good idea to add a couple of protective layers. Start with requiring longer and more complicated passwords. Then turn on a lockout policy (you can lock an account if there was a certain number of consecutive failed attempts to log in). Another good idea is using Captcha, a bot can not choose a picture with a cat after all. Finally, offer two-factor authentication brute force protection to your users, better protection for accounts has not been invented yet. - The Pros and Cons of Different Two-Factor Authentication Types and Methods - Man In The Middle Attack Prevention And Detection - Doxing. What Is It? How to Dox? How to Protect Yourself from Doxing? - Top 7 Tips How to Protect Yourself from Phishing Scams - Social Engineering: What It Is and Why It Works - Ransomware – to Pay or Not to Pay - 8 Ways to Hack Your Email - The Most Common Ways of Credit Card Fraud
As the average temperature of the Earth rises due to climate change, the temperature of the oceans rises as well. These drastic rise in ocean temperatures, affect marine organisms of all shapes and sizes. However, the most prominent effects have been observed on corals. Corals, which are home to thousands of marine creatures, are considered to be some of the most fascinating and eye pleasing marine organisms in the oceans. Unfortunately, they are also highly sensitive to environmental changes. In a recent article published in Science News (which can be found here), coral migration was studied and tracked by a group of scientists off the coasts of Japan. When they compared current results to data collected from different time periods starting in the 1930’s, they found out that various common coral species have retreated northward, and some have even gone as far as temperate waters. Furthermore, the abundance of coral has decreased proportionately with northward migration. Mila Zinkova/Wikimedia Commons If this trend were to continue and not be altered, the population of corals in the oceans will continue to decline. This decline is very unfortunate and it shows how deadly climate change can be. Corals are home to thousands of different marine organisms. Hence, the lost of corals, also causes the direct loss of other marine organisms. Ultimately this can lead to an overall reduction in biodiversity. Furthermore, the decline in coral also jeopardizes recreational activities such as scuba diving and snorkeling. Although this article, provides excellent evidence to support the fact that corals are moving north and their abundance is decreasing. It does not provide us with ways to prevent or slow down this process. Most of us are already aware of the drastic effects climate change has on marine organisms, but very few of us know how to directly prevent such events from occurring. Hopefully we’ll see more media coverage on prevention methods in the future, so that such events can be prevented or subdued in the future.
German: Freiherr (in German ˈfʁaɪˌhɛɐ̯/; male, abbreviated as German: Frhr.), German: Freifrau (in German pronounced as /ˈfʁaɪˌfʁaʊ/; his wife, abbreviated as German: Frfr., literally "free lord" or "free lady") and German: Freiin (in German pronounced as /ˈfʁaɪ.ɪn/; his unmarried daughters and maiden aunts) are designations used as titles of nobility in the German-speaking areas of the Holy Roman Empire, and in its various successor states, including Austria, Prussia, Bavaria, Liechtenstein, Luxembourg, etc. Traditionally it denotes the titled rank within the nobility above German: [[Ritter]] (knight) and German: [[Edler]] (nobility without a specific title) and below German: [[Graf]] (count, earl) and German: [[Herzog]] (duke). The title superseded the earlier medieval form, German: Edelherr. The title German: Freiherr derives from the historical situation in which an owner held free (allodial) title to his land, as opposed "unmittelbar" ("unintermediated"), or held without any intermediate feudal tenure; or unlike the ordinary baron, who was originally a knight (German: Ritter) in vassalage to a higher lord or sovereign, and unlike medieval German ministerials, who were bound to provide administrative services for a lord. A German: Freiherr sometimes exercised hereditary administrative and judicial prerogatives over those resident in his barony instead of the liege lord, who might be the duke (German: Herzog) or count (German: Graf). The German-language title of German: Freiherr is rendered in English as "Baron", although the title was derived separately in the two languages. Even in German, a German: Freiherr is often styled and addressed as "Baron" in social circumstances, although not the official title. The original distinction from other barons was that a German: Freiherrs landed property was allodial instead of a fief. Barons who received their title from the Holy Roman Emperor are sometimes known as "Barons of the Holy Roman Empire" (German: Reichsfreiherren), in order to distinguish them from other barons, although the title as such was simply German: Freiherr. Since the dissolution of the Holy Roman Empire in 1806, German: Reichsfreiherren do not at present belong to the noble hierarchy of the realm. By a decision of the Congress of Vienna in 1815, their titles were nonetheless officially recognised. From 1806 the then independent German monarchies, such as Bavaria, Württemberg and Lippe could create their own nobility, including German: Freiherren (although the Elector of Brandenburg had, as king of the originally exclusively extraterritorial Prussia even before that date, arrogated to himself the prerogative of ennoblement). Some of the older baronial families began to use German: Reichsfreiherr in formal contexts to distinguish themselves from the new classes of barons created by monarchs of lesser stature than the Holy Roman Emperors, and this usage is far from obsolete. As with most titles and designations within the nobility in the German-speaking areas of Europe, the rank was normally hereditary and would generally be used together with the nobiliary particle of German: [[von]] or German: zu (sometimes both: German: von und zu) before a family name. The inheritance of titles of nobility in most German-speaking areas was not restricted by primogeniture as is the baronial title in Britain. Hence, the titles applied equally to all male-line descendants of the original grantee in perpetuity: All legitimate sons of a German: Freiherr shared his title and rank, and could be referred to as German: Freiherr. The wife of a German: Freiherr is titled German: Freifrau (literally "free lady"), and the daughter of a German: Freiherr is called German: Freiin (short for German: Freiherrin). Both titles are translated in English as "Baroness". In Prussia and some other countries in northern Europe, the title of Freiherr was, as long as the monarchy existed, usually used preceding a person's given name (e.g. German: Freiherr Hans von Schwarz). In Austria-Hungary and Bavaria, however, it would be inserted between the given name and the family name (e.g. German: Hans Freiherr von Schwarz). After the First World War, the monarchies were abolished in most German-speaking areas of Europe, and the nobility lost recognition as a legal class in the newly created republics of Germany and Austria. The Republic of Austria abolished hereditary noble titles for its citizens by the German: Adelsaufhebungsgesetz of 3 April 1919 and the corresponding decree of the state government. The public use of such titles was and still is prohibited, and violations could be fined. German: Hans Freiherr von Schwarz, as an Austrian citizen, therefore lost his title of German: Freiherr von and would simply be named as German: Hans Schwarz in his Austrian passport. In practice, however, former noble titles are still used socially in Austria; some people consider it a matter of courtesy to use them. The late German: [[Otto von Habsburg]], in his childhood Crown Prince of Austria-Hungary, was styled German: Otto Habsburg-Lothringen in his post-1919 Austrian passport, and German: Otto von Habsburg in his German passport (he was a Member of the European Parliament for Germany). In 2003, the Constitutional Court (German: Verfassungsgerichtshof) ruled that an Austrian woman having been adopted by a German carrying an aristocratic title as part of his name is not allowed to carry this title in her name. The Federal Administrative Court (German: Verwaltungsgerichtshof) in a similar case asked the European Court of Justice whether this Austrian regulation would violate the right of the European Union; the European Court of Justice did not object to the Austrian decision not to accept the words German: Fürstin von as part of an Austrian woman's name. The German republic, under Article 109 of the Weimar Constitution of 1919, legally transformed all hereditary noble titles into dependent parts of the legal surname. The former title thus became a part of the family name, and moved in front of the family name. German: Freiherr Hans von Schwarz, as a German citizen, therefore became German: Hans Freiherr von Schwarz. As dependent parts of the surnames ("German: nichtselbständige Namensbestandteile") they are ignored in alphabetical sorting of names, as is a possible nobiliary particle, such as German: [[von]], and might or might not be used by those bearing them. Female forms of titles have been legally accepted as a variation in the surname after 1919 by a still valid decision of the former German High Court (German: [[Reichsgericht]]). The distinguishing main surname is the name, following the Freiherr, Freifrau or Freiin and, where applicable, the nobiliary particle – in the preceding example, the main surname is German: Schwarz and so alphabetically is listed under "S". Similar titles have been seen in parts of Europe that have historically been dominated by Germany (in the cultural sense): the Baltic States, Austria–Hungary, Sweden, Finland and to some extent in Denmark–Norway. From the Middle Ages onward, each head of a Swedish noble house was entitled to vote in any provincial council when held, as in the Realm's Swedish: [[Herredag]], later Swedish: [[Riddarhuset]]. In 1561, King Eric XIV began to grant some noblemen the titles of count or baron (Swedish: friherre). The family members of a Swedish: friherre were entitled to the same title, which in time became Baron or Baronessa colloquially: thus a person who formally is a Swedish: friherre now might use the title of "Baron" before his name, and he might also be spoken of as "a baron". However, after the change of constitution in 1809, newly created baronships in principle conferred the dignity only in primogeniture. In the now valid Swedish Instrument of Government (1974), the possibility to create nobility is completely eliminated; and since the beginning of the twenty-first century, noble dignities have passed from the official sphere to the private. In Denmark and Norway, the title of Danish: Friherre was of equal rank to that of Baron, which has gradually replaced it. It was instituted on 25 May 1671 with Christian V's Danish: Friherre privileges. Today only a few Danish noble families use the title of Danish: Friherre and most of those are based in Sweden, where that version of the title is still more commonly used; a Danish Danish: Friherre generally is addressed as "Baron". The wife of a Danish or Norwegian Danish: Friherre is titled Danish: Friherreinde, and the daughters are formally addressed as Danish: Baronesse. . With the first free Constitution of Denmark of 1849 came a complete abolition of the privileges of the nobility. Today titles are only of ceremonial interest in the circles around the Monarchy of Denmark In 1561, the Swedish king Eric XIV conferred the hereditary titles of count and Finnish: vapaaherra ("baron") on some persons, not all of them nobles. This prerogative was confirmed in the constitutional arrangements of 1625. All family members of Finnish: vapaaherra (baronial) families were entitled to that same title, which in practice, came to mean that they were addressed as Finnish: Paroni or Finnish: Paronitar. The Finnish nobility shares most of its origins with Swedish nobility. In the beginning, they were all without honorific titulature, and known just as "lords". In subsequent centuries, while Finland remained an autonomous grand duchy, many families were raised in rank as counts, Finnish: vapaaherras, or as untitled nobles. Theoretically, all created Finnish: vapaaherra families were given a barony (with some rights of taxation and jurisprudence), but such fiefs were only granted in the 16th and 17th centuries. Thereafter the "barony" was titular, usually in chief of some already-owned property, and sometimes that property was established as a Latin: [[fideicommiss]]. Their property tax exemption continued into the 20th century, being, however, diminished substantially by reforms of the 19th century.
Between kindergarten and twelfth grade, students are expected to learn how to study, schedule their time and complete sizable assignments without procrastinating. Yet these skills often aren’t taught explicitly. With the increased self-sufficiency necessitated by virtual education, educators and parents can help students learn and manage their goals more effectively by directly teaching study skills. Daniel Willingham, a psychologist at the University of Virginia, studies the application of cognitive psychology in education. He recently spoke at a Learning and the Brain conference about the science behind study techniques. “Kids are more on their own now than they typically are,” Willingham told MindShift. Students need to independently log in to class on time and maintain focus in their home environments. By explicitly teaching how to avoid distraction, combat procrastination and study effectively, educators entrust students with the necessary skills for educational challenges faced both virtually and in person. STRATEGIES FOR AVOIDING DISTRACTION When studying or in virtual class, students may keep their phones nearby and subsequently get distracted by notifications. They might decide to respond to a notification, figuring it can be handled quickly, and then be sucked into a digital rabbit hole. This could amount to missing parts of class or wasting time set aside for homework. Coupled with potential noise distractions, at-home learning environments can test students’ attention spans. TIP 1: Change Your Space Willingham encourages students to ask themselves: “Have you made your environment as distraction-free as you can?” While many students’ options are limited during virtual learning, selecting the best location in a home comes from carefully considering one’s personal sources of distraction. If notifications constantly grab students’ attention, they can turn them off on their phones and laptops. Should a phone’s proximity be a temptation, they can place their phone in another room during class or study time. Non-virtual disturbances, like noise, can be curbed through noise-cancelling headphones or inexpensive foam earbuds. Charting their most common sources of distraction encourages students to be more cognizant about their personal obstacles and take more active roles in their learning. TIP 2: Don’t Choose Distraction “Multitasking almost always exacts a cost. So if you add a second task, it is going to reduce the efficiency of that first task,” Willingham said. While students likely recognize that they put less effort into their work when they choose to also watch TV, text or play music, they may underestimate the impact of multitasking on their task’s accuracy and duration. “It’s very clear that multitasking is not helping them, even though they mostly think it’s fine,” he said. According to Common Sense Media, 51% of teens and 34% of tweens (ages 8 through 12) watch TV while studying. More than 70% of teens and tweens believe that a TV playing in their environment won’t affect their homework. When it comes to social media, 50% of teens use it while studying, and 69% of teens and tweens believe checking social media won’t impact their work. Among the forms of multitasking, data is more varied when it comes to playing music while studying. Different studies’ results range from no effect to detrimental impacts to benefits. “Listening to music does distract, so it is taking away from cognition. But the other thing listening to music can do is it can energize,” Willingham said. Music can boost the autonomic nervous system with emotionally uplifting tracks that can increase heart rates and blood pressure. This can be useful for athletic and potentially academic motivation. The impact of music may be based on the student’s interest in the task and the challenges of the task itself — a student could choose to press play based on their needs and situation. TIP 3: Ask “Do You Want Social Media, or Enjoy it?” Though the brain’s dopamine-carrying mesolimbic pathway was initially theorized as related to situations of pleasure or reward, research from the past decade suggests that the pathway has less to do with reward and more with repetition, regardless of the happiness provided by the task. Over the past decade, social media also became more societally ubiquitous, with more people spending more time online — though not necessarily because social media provides pleasure. Willingham encourages parents and teachers to ask students whether they enjoy social media, or simply want it — and if they find that divide meaningful. When he posed that question to teens and tweens, many said, “ ‘Once I’m on, it’s really not that fun. It’s just like there’s lots of drama. It’s a lot of stuff. It’s not interesting. It’s people posing. And yet I still feel really compelled for some reason to get on there,’” he said. The suggestion that there’s a difference between wanting to go on social media and actually enjoying being online may be significant to students. The next time a social media notification appears, they may pause. If they recognize that while they feel pulled to scroll, they don’t typically enjoy the time they spend online, they might choose to not pursue that distraction. TIP 4: Plan Breaks If students find themselves constantly distracted, they might just need a break. Data shows that brief breaks rejuvenate students, allowing them to return to schoolwork with heightened concentration. Planned breaks are more effective than spontaneous ones, however. Scheduling breaks ensures the pause remains brief and that students return to their work. The Pomodoro Technique provides one example for this, though Willingham stated that there’s no need to follow the specific time allotments of Pomodoro precisely. Knowing when a break is coming up can also influence motivation: when a student feels tempted to give up, seeing that their next break is in five minutes or less may encourage them to keep up their work until that break. Achieving goals improves self-esteem, allowing students to feel positively about their ability to regulate work habits. TIP 5: It’s Still School When students arrive at their virtual classes in PJs, under bed covers and in varied states of wakefulness, they might not as easily accept that they’re in a school setting. “For some kids I know, learning at home doesn’t feel like school,” Willingham told MindShift. In-person school environments are structured to allow for effective learning and to minimize distraction. Outside that context, students may find paying attention more difficult. When parents and guardians emphasize that virtual school “is still school,” Willingham said, they can help their students structure their mindsets to tune out disturbances. By encouraging students to prepare for virtual school similarly to how they’d prepare for in-person instruction — by eating breakfast, getting dressed and showing respect for their teachers — parents can help achieve that mindset. A workshop for parents may be helpful to that end, but educators should be mindful that parents might be more willing to hear this message from another parent. Someone who’s also been dealing with the challenges of raising a child during a global pandemic can help foster a dialogue that feels honest and realistic. WHY WE PROCRASTINATE — AND HOW TO FIGHT IT There are three main reasons why students procrastinate: the task is “boring”; the task seems overwhelming or impossible; the task provokes fears of failure, causing a student to self-sabotage. Willingham suggests these ways to address and prevent procrastination: TIP 1: Start work in class Simply beginning the work makes headway against procrastination. Data from exercise studies show that people tend to underestimate how much they’ll enjoy a given task. Once they begin, they often find that task less boring or overwhelming than predicted. Teachers can initiate this process by devoting the last five to ten minutes of class time to beginning an upcoming project or paper. Starting the project means that a student is more likely to continue outside of class. This also allows students time to directly ask the questions they need answered in order to begin. TIP 2: Use a planner — and make it a habit When students aren’t told to plan out their work – or shown how to schedule — they tend to struggle. Scheduling portions of a hefty task allows the task to feel more manageable, meaning it won’t loom over students’ heads until the last minute. Teaching students to use a planner means not only teaching them to write down the dates of big exams and projects, but also reminders and scheduled work or study times for chipping away at the task. Repetition and enforcement helps planner usage become a habit. Much in the way that large-scale construction projects tend to finish over-schedule and over-budget, people tend to underestimate how much time is required and how many resources are needed for a task. This is because humans generally discount roadblocks they find unlikely — but if there are 50 low-probability events for a given task, there’s a higher probability one of those events will occur. “Tell students, ‘When you’re doing your planning, whatever time estimate you come up with, double it,’” Willingham said. By thinking in terms of time, rather than task, students can pace themselves and prepare for the unexpected. Many students may look at their planners, see that no assignment is due the next day and think they get the night off, only to find themselves staying up late the next night with multiple tasks. Instead, if a student commits to working every day for at least 30 minutes, they’ll have a cushion if anything surprising pops up. TIP 3: Practice Breaking Down Tasks Students need to learn how to break up large tasks into bite-sized chunks. While they’re fully capable of doing this, they might not know how to go about it. Demonstrating and teaching this concept directly can help guide students toward success. One way students can practice is by working in small groups to brainstorm strategies for dividing up tasks. This allows teachers to give feedback about different strategies’ efficacies and allows students to crowdsource new approaches. “It’s the perfect kind of thing you could do in a Zoom breakout room,” Willingham said. Self-sabotaging, also known as self-handicapping, “is the idea that you procrastinate knowing that you’re setting yourself up for failure,” Willingham said. Separate from the other two reasons for procrastination, self-sabotaging comes from a student’s fear that even if they tried their hardest on an assignment or test, they wouldn’t succeed. They procrastinate in order to give themselves an excuse for a failure they fear is inevitable. A bad grade can be blamed on their “choice” to procrastinate, rather than seen as a true metric of their ability or knowledge. Teachers can likely guess which of their students possess this fear of failure. They can talk with the student one-on-one, telling the student that they will succeed if they put in the effort. Invoking a growth mindset might be helpful here, as might working together to develop a new strategy for the task. This may involve breaking tasks down or troubleshooting together, and then monitoring that student’s progress with the new strategies. Providing continual support allows the student to feel as though their teacher is with them for the long haul. HOW TO KNOW WHEN TO STOP STUDYING Students think they know when to stop studying for an exam: when they feel like they know the material. Humans generally consider ourselves good judges of what we know and don’t know — but we might be worse at this than we think, said Willingham. In one study, many participants were quick to say they knew how a toilet worked. But when asked to explain what makes a toilet flush, they found they couldn’t. This points to a common misunderstanding of memory. We think that if we quickly scan our minds and see a concept, we know that concept and could explain it if we tried. But sometimes, we’re only vaguely familiar with how toilets work. “People actually are not so good at knowing what they know,” Willingham said. TIP 1: Feeling That You Know Something Is Not Reliable When students assess whether they know a topic, they should consider whether they’re only familiar with it. The scientific definition of familiarity is knowing that one has seen a stimulus before, but possessing few other pieces of knowledge about it. Familiarity allows us to operate quickly — we assume we could say more about the topic if we thought about it. “Partial access” provides a similar fallacy — sometimes when we know a few things about a topic, we assume we know it in full. Recollection, conversely, involves deeper mental associations and the ability to explain something rather than simply recognize it. While a student may feel they know a concept when they read a line of their notes, close their eyes and immediately repeat that line back, checking back after time has passed ensures that the knowledge isn’t only stored in short-term memory. Students can test whether they know a concept by stepping away from their notes for a half-hour or more and then self-testing. TIP 2: Studying Until You Know Is Not Enough Though a student may feel they can stop studying once they receive 100% on a practice test, this score may not ensure success on the actual exam. “What they’ve forgotten is that forgetting happens,” Willingham said. To protect themselves against forgetting, Willingham encourages students to plan their studying so that it includes time to study even after mastering a self-test. By including a buffer between self-test mastery and the actual exam, students can continue practicing the concept, reducing the likelihood of forgetting material during that time. This may involve using the scheduling techniques mentioned above. Students can be encouraged to save roughly 20% of their study time for this buffer, meaning that mastery should be achieved by the penultimate night before the exam so that the night before can be used for review. TIP 3: Creating Study Materials Is Studying Students might forego creating their own study materials if they find resources online that are similar enough, believing this would allow them to begin studying “sooner.” “They don’t realize creating their own study materials is actually a really, really effective way of studying,” Willingham said. Making their own study guides, flashcards or Quizlets not only allows students to review their notes, but ensures the materials they use are on-topic and accurate — as opposed to a readily accessible Quizlet made by a stranger. TIP 4: “Knowing” Means Being Able To Explain A student might believe they “know” a concept but can’t explain it. Often, this comes from the idea that the student couldn’t comprehend the teacher’s first explanation of the concept, but with further review, readings and questions, the concept now makes sense — when the teacher explains it. This student wouldn’t feel able to put the concept in their own words or thoroughly discuss it. Tell students that “knowledge” doesn’t mean that a concept only makes sense when reading about it or hearing it explained – it means being able to explain it oneself. This ensures that students define knowledge with the correct criterion and can more confidently determine when they know a concept. TIP 5: Use In-class Queries Quick tests that require students to produce knowledge allow them to check their understanding of a concept. These can involve clickers, Zoom polls or exit tickets, as well as Zoom breakout rooms or small-group discussions based on producing knowledge or demonstrating specific skills. Interactions like this allow a student to see if they actually know a concept or require more studying. They allow teachers to take note of their classes’ levels of understanding, too. These management techniques can help bolster students working with heightened autonomy during virtual learning. When teachers, parents and caregivers directly explain and model these strategies, they provide students with tools to use the next time they feel distracted, pulled to procrastinate or unsure if they’re ready for an exam. With these tools, students can learn how to address these situations independently — and how to ask for the specific support they need.
Quantum particles. In the world you know, actions have causes and effects, objects exist as one thing or another, and everything is what it is whether you observe it or not. In the quantum world, those rules go out the window. Take quantum entanglement, for example. You can make two quantum particles interact, then put them at opposite ends of the universe, and measure one. Whatever measurement you get, the other particle takes on a corresponding quality instantaneously, no matter the distance. Well, forget distance — particles can even be entangled through time. What Is Quantum Mechanics? Quantum mechanics is the branch of physics relating to the very small. It is the body of scientific laws that describe the wacky behavior of photons, electrons and the other particles that make up the universe. It results in what may appear to be some very strange conclusions about the physical world. At the scale of atoms and electrons, many of the equations of classical mechanics, which describe how things move at everyday sizes and speeds, cease to be useful. In classical mechanics, objects exist in a specific place at a specific time. However, in quantum mechanics, objects instead exist in a haze of probability; they have a certain chance of being at point A, another chance of being at point B and so on. Miniscule Time Travel To understand quantum entanglement, think about a pair of gloves. If you see a right-handed glove you know that its mate is left-handed, even if it’s nowhere to be seen. But in quantum entanglement, it’s as if seeing a right-handed glove actually turned the other glove left-handed. It’s what Einstein called “spooky action at a distance.” This entanglement, it turns out, extends to time as well. In 2013, a team of researchers actually demonstrated this weird phenomenon in the lab. Here’s how they did it. - First, they created an entangled pair of photons, ‘1-2’ (step I in the diagram below). - Soon after, they measured the polarisation of photon 1 (a property describing the direction of light’s oscillation) – thus ‘killing’ it (step II). - Photon 2 was sent on a wild goose chase while a new entangled pair, ‘3-4’, was created (step III). - Photon 3 was then measured along with the itinerant photon 2 in such a way that the entanglement relation was ‘swapped’ from the old pairs (‘1-2’ and ‘3-4’) onto the new ‘2-3’ combo (step IV). - Some time later (step V), the polarisation of the lone survivor, photon 4, is measured, and the results are compared with those of the long-dead photon 1 (back at step II). The upshot? The data revealed the existence of quantum correlations between ‘temporally nonlocal’ photons 1 and 4. That is, entanglement can occur across two quantum systems that never coexisted. What on Earth can this mean? Prima facie, it seems as troubling as saying that the polarity of starlight in the far-distant past nevertheless influenced the polarity of starlight falling through your amateur telescope this winter. Even more bizarrely: maybe it implies that the measurements carried out by your eye upon starlight falling through your telescope this winter somehow dictated the polarity of photons more than 9 billion years old. Did measuring particle 1 send information to the future to affect particle 4? Did measuring particle 4 retroactively change the measurement of particle 1? Neither question makes sense because, as hard as it is to fathom, quantum systems don’t have definite properties. Their properties change based on when and how they’re measured. Both options are true, and neither. Forget it; it’s quantum town. Heads Or Tails – You Loose For a more real-world example, consider this thought experiment conceived by physicists at the University of Vienna. John and Jane play a coin-toss game: they take turns secretly tossing a coin, then writing down their result and their prediction for the other person’s toss on a piece of paper. When they’re done, they give their paper to the other person, and the other person tosses their coin. If Jane does the coin toss first and writes down her result and her prediction, hands her paper to John, she will have a 50 percent chance of being right. But John knows the answer and so he’ll have a 100 percent chance of being right. The opposite would happen if John went first. Whatever order they do it in, it always averages out to a 75 percent success rate overall. But if you don’t have them do this in a certain order, and you swap the paper for a quantum particle and the coin-toss results for measurements of that particle, you get an 85 percent success rate. It’s as if seeing the results retroactively improves the players’ chances of guessing right, as if they can look into the future. That’s entangled time. It’s not just a mind-bending thought experiment either — if we can harness it, it could mean big things for future technology. If we could do it through time, who knows what kind of breakthroughs could arise?
What Is A Compound? A compound is a substance formed by chemically bonding two or more different elements or atoms. The bonding can be either ionic or covalent type. Example: sodium chloride (ionic compound), water (covalent compound). Types Of Compounds Generally, compounds are of two types based on chemical composition. They are - Organic compound - Inorganic compound What Is An Organic Compound? An organic compound is a class of chemical compounds that contains carbon, hydrogen, and other atoms. It is also known as hydrocarbons (compounds which contain carbon-hydrogen bond). A million organic compounds are known till now. These organic compounds are the main components of living beings. In the carbon cycle and photosynthesis, the conversion of inorganic compounds to organic compounds like simple sugar occurs. Most of the synthetically produced organic compounds are from Petrochemicals mainly hydrocarbons. The basic properties of carbon leads to formation of large number of organic compounds. these properties are - Catenation (formation of chains with other carbons) - The small size of carbon. What Is An Inorganic Compound? An inorganic compound is also a class of chemical compounds that do not contain carbon in most cases and which do not have any carbon-hydrogen bond in it. Most of the inorganic compounds are present in the earth’s crust. Some simple carbon-containing compounds like carbon dioxide, carbon monoxide, carbides, cyanides, etc., are considered inorganic compounds. Differences Between Organic and Inorganic Compound \|Organic Compound\|\|Inorganic Compound\| \|An organic compound is defined as the class of chemical compound which contains carbon, hydrogen, and oxygen.\|\|An inorganic compound is defined as a class of chemical compounds that do not contain any carbon-hydrogen bond.\| \|Organic compounds are soluble in organic solvents and insoluble in water.\|\|Inorganic compounds are soluble in water and insoluble in organic solvents.\| \|Melting and boiling points\| \|Organic compounds have low melting and boiling points.\|\|Inorganic compounds have high melting and boiling points.\| \|Due to the presence of carbon, catenation is exhibited.\|\|No catenation is exhibited by inorganic compounds.\| \|Organic compounds exhibit isomerism.\|\|Inorganic compounds don't exhibit isomerism.\| \|Rate of reaction\| \|A slow rate of reaction can be seen in organic compounds.\|\|A high rate of reaction can be seen in inorganic compounds.\| \|Flammability and volatility\| \|Organic compounds are flammable and highly volatile.\|\|Inorganic compounds are not flammable and non-volatile.\| \|Most organic compounds are colorless.\|\|Most inorganic compounds are colorful.\| \|Organic compounds form covalent bonds.\|\|Inorganic compounds form ionic bonds.\| \|Conductance of heat and electricity\| \|In an aqueous solution, organic compounds act as poor conductors of heat and electricity.\|\|In an aqueous solution, inorganic compounds act as good conductors of heat and electricity.\| \|Organic compounds are biological and more complex in nature.\|\|Inorganic compounds are not complex and are minerals that exist in the earth's crust.\| \|Making of Salts\| \|Organic compounds can't make salts.\|\|Inorganic compounds can make salts.\| \|Facts, nucleic acids, sugars, enzymes, proteins, etc.\|\|Nonmetals, salts, medals, acids, bases, etc.\| The major difference between organic compounds and inorganic compounds is that the organic compounds are mostly made up of hydrocarbons but inorganic compounds didn’t have any carbon-hydrogen bonding. The other properties like conductance, flammability, volatility, solubility, etc., will also differ because of the difference in the chemical composition.
Talking about Decisions that Have Been Made by Others The ～ことになる pattern is similar to the ～ことにする pattern that we learnt in Year 12. - With ～ことになる, the decision is not necessarily made by us. - Or, the decision could have been forced on us by circumstances beyond our control. - We may not know who made the decision - it's could just be the way things are. - There are few jobs in my town, so I've had to move to a bigger town. In the example above, the sentence ends in the past tense because the action was a one-off and has already taken place. - At my school, classes on Wednesdays finish at 2 o'clock. In the example above, the sentence ends in the present continuous tense because the action is ongoing. i.e. Classes end at 2 every Wednesday. - (It has been decided that) we will sit our university entrance exams in November. In the example above, the sentence ends in the present continuous tense because although the decision has been made and continues to affect us, the action has not yet taken place.
The Civil War general and 19th US president, Rutherford Birchard Hayes (1822–93) was born in Delaware, Ohio, the son of a shopkeeper who died before his birth. He graduated as class valedictorian from Kenyon College in 1842, and then attended Harvard Law School, later practicing law in Cincinnati. When the Civil War began, Hayes was appointed a major in the Ohio Volunteer Infantry by the governor. He saw frequent battle and suffered severe injuries in 1862. In 1864, voters elected him to the US Congress and later the governor’s office, which he occupied until 1877. His prominence as governor and as a rising star in the Republican Party led to his nomination for president in the election of 1876. Despite one of the tightest presidential elections in history, he emerged victorious. Deciding not to seek reelection, he retired after one term and moved back Spiel Grove, his house in Fremont, Ohio. Author: Rutherford B. Hayes Rutherford B. Hayes The National Soldiers’ Home in Dayton, Ohio provided a place to care for disabled Civil War veterans. Several such homes were built across the country, but the Dayton site became the largest, and was the first to admit black veterans of the war. It was here, on September 12, 1877, the Country’s Defenders Soldiers’ Monument was unveiled and dedicated, to honor not the great generals but the common American soldier.
Answer the following question. Explain the secondary functions of money. Answer the following question. State any three functions of money. Secondary Functions of Money:- 1. Standard of deferred payments:- In the modern economy many transactions take place without instant payments. The debtors make a promise to make payments on some future date. Such future payments are possible because of money. Under Barter System taking loan was easy, but its repayment was difficult because loans were in the form of grains or cattle. Money facilitates lending and borrowings, because the borrowings are in the form of money and the repayment are also in the form of money. Due to general acceptability, stability of value compared to other goods, durability etc., money acts as a standard of deferred payments. 2. Store Value:- Money works as a store of value. Along with satisfaction of present wants, provision for satisfaction of future wants is equally important. It requires savings from the current earnings. Money is a convenient means through which savings can be done easily: According to Lord J.M. Keynes, "money is a link between the present and the future." Money serves as a store of value because money has purchasing power. It can be used to purchase real assets like land, house etc. and financial assets like shares, debentures, bonds, etc. 3. Transfer Value:- Today with the extension of trade among various countries and organizations it becomes necessary to transfer purchasing power from one place to another. This is easily done by money. Money helps to shift the purchasing power from one place to another e.g. real assets like building or agricultural land from one place can be sold and with the help of that money, building or land can be purchased at some other place. 1. Store of Value - Generally, people have a tendency to save a certain portion of their income in the form of savings and to accumulate wealth. Under the Barter system, such storage of wealth was not possible due to the perishable nature of certain commodities. As against this, wealth can be easily stored in the form of money without any loss in its value. Thus, a store of value as a function of money implies that money can be easily saved and used for future needs. The store of value function of money can be justified because of the following reasons. - Money is the most widely accepted as a medium of exchange. - There is no loss in the value of money over time (though there exists a loss of value of money due to inflation but it is negligible). - Money can be stored conveniently and does not involve any cost. 2. Standard of Deferred Payments - Deferred Payments refer to future payments and contractual payments such as loans and interest payments, salaries, etc. As money is widely accepted as a medium of exchange and can be used to store value without much loss of value, so it can be used for future payments. 3. Transfer of Value - Money can be transferred easily from one place to another and from one person to another. Therefore, it implies that with the help of money, purchasing power can be transferred. An individual who is having money has purchasing power and he/she can transfer the purchasing power to anyone just by transferring money. For example, when a father is giving pocket money to his son, he is indeed transferring purchasing power to his son to buy different goods and services.
To glimpse any one of the sea turtles who nest in Costa Rica is an inspiring experience. All are magnificent, mysterious creatures with distinct qualities: the astonishing arribadas of the Olive ridley the impressive strength of the Loggerhead sea turtle; the nimble maneuvers of the Green turtle; the gorgeous colors of the hawksbill sea turtle; and the gigantic hulk of the l[Leatherback](/costa-rica/attractions/marino-las-baulas-national-park) turtle. All are fascinating. Nevertheless, the global populations of sea turtles are declining at an alarming rate. Hawksbill global population, at about 8,000 nesting females, is one of the most frightening scenarios. The hawksbill’s population has been cut by more than 80% in just 100 years. The other sea turtle numbers are not as low, but all are in the tens or hundreds of thousands. Consider that their populations used to include millions and millions of sea turtles. These creatures are not doing well. The reproductive rates of the turtles are slow, so it is difficult for them to recover from slaughter by poachers and fishermen. Even natural predators, and many of them, wait for baby turtles to hatch. The survivors mature slowly—it can take up to 40 or 50 years before a sea turtle is ready to mate and reproduce. Between slow maturation and a high death rate, it is a very real possibility that these endangered creatures will become extinct. It is crucial for us to realize this and take action to help and protect them. The most direct harm to the sea turtles is caused by poachers who kill adult turtles for their meat, fat, and shells, and dig up turtle eggs. Both meat and the eggs are considered delicacies and the shells are turned into souvenirs. Buying any part of a turtle is unethical and illegal. Turtles also get caught in the trawlers of fishermen. Pregnant females drown in commercial shrimp and fish nets when they swim through shallow waters to nest. At key moments a sea turtle’s life cycle is sensitive to light and temperature, which have been changed by human activity in recent years. When baby turtles hatch, they head toward the brightest light, which used to draw them to the sea. With so much light from cities visible on the horizon, millions of young turtles head toward land instead of the water. When the sun rises, they die unprotected from the heat. This is photopollution, when manmade light sources disrupt natural patterns of light and darkness. Meanwhile, ever popular beachfront development continues to spread on and destroy fragile nesting sites and contribute light and noise pollution which scare off and confuse nesting females and new hatchlings. Another disruption of the sea turtle’s life cycle is within the egg itself. The temperature of the sand around the egg affects how long the turtle needs to grow before hatching. Temperature also determines the sex of the baby. This is called temperature-dependent sex determination. Rising climate due to global warming is affecting this sensitive egg development, interrupting the proportions of males to females among sea turtles. These are just a few of the ways we are directly and indirectly harming sea turtles. It is important that we extend help to them now. Sea turtles serve important ecological functions and we need them to survive. These reptiles play vital roles in their food webs that affect humans. For example, some jellyfish eat the larvae of fishes that are wanted for human consumption. When leatherback turtles eat the jellyfish, more of the fish survive that people want eat. The olive ridley and the loggerhead have interactions with species that affect the survival of other animals and plants in the ocean, and the health of the ocean affects human well-being. Sea turtle diets, like those of the hawksbill and green turtle, are also part of the delicate balance with coral reefs and seagrass beds. Coral reef health affects huge regions of ocean and land, and seagrass health affects many other species of fish that are important to the fishing industry. If the sea turtles disappear, some of our own food sources will decline, too. The international community has recognized the need to protect sea turtles for several decades. Global networks, like the IUCN*, work to find solutions to environmental problems such as protecting sea turtles across many countries’ boundaries. CITES is an international agreement between governments; countries that work together in CITES try to regulate trade so that wild plants and animals are not endangered by international exchange. To actually do this requires impressive cooperation of many governments. Sea turtles are strictly restricted in international trade. Costa Rica protects the beaches where sea turtles come to nest. All visitors are required to obey regulations for the turtles’ safety. This country does participate in CITES and does not allow killing sea turtles for food or any other reason. Other countries that allowed harvesting turtles and eggs no longer have any turtles gracing their shores. It is illegal for fishermen to ignore precautions that help protect sea turtles. In a few circumstances, such as those of the olive ridley, the government permits citizens to collect eggs during certain time periods. Costa Rica’s government and the international community make an effort to defend these species of turtles. As strong as these international promises may be, funds, manpower, and resources still run short and sometimes laws are not fully enforced. It cannot be understated how essential it is for visitors to Costa Rica and other countries to understand the importance of these creatures and know how to help. People flock every year to witness turtles in any activity. As we enjoy the beauty of the loggerhead and the agility of the green turtle, we must help them in return. When you are in Costa Rica, or any country where sea turtles live or turtle products are sold, you can help in several ways. Do not buy any food or souvenir that came from a turtle. As long as there is a market for souvenirs from shells or foods made with turtle eggs or meat, the fate of these delicate creatures is at greater risk. Refusing to purchase any items does make a difference. When visiting turtle nesting beaches, it is important to strictly follow rules that help protect the turtles. Be quiet, do not make sudden movements, and do not use any lights or camera flashes. When diving or snorkeling, trying to touch or feed a turtle is not safe for you or the sea turtle. Here is the full sized Turtle Nesting Map The populations of these turtles are shrinking so fast that any more harm is significant and long-lasting. Sea turtles naturally have a low survival rate from birth, and human pressures may prove fatal to these graceful mysteries. Preserving their beaches and respecting their space both on land and in water is vitally important for their survival. The IUCN is the International Union for Conservation of Nature. CITES is the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). CITES Organization website. International Union for Conservation of Nature (IUCN). IUCN website. World Wildlife Foundation Organization website. Leenders, Twan. A Guide to Amphibians and Reptiles of Costa Rica. Zona Tropical, S.A, Miami, FL, 2001. Trustpilot 5-star rated Find inspiration by browsing our curated vacation collections.
An important concept when talking about a thermos is heat. Heat means more than just what's hot and cold. Heat can be quantified as the amount of thermal energy a material has - basically, how fast the temperature is causing the molecules to wiggle. The faster they wiggle, the hotter the material is. When heat is transferred from one object to another, the wiggling molecules transfer their energy to the molecules of the other material. Whether something is heating up or cooling down, it has to be able to give or get thermal energy. But thermoses are made out of specialized materials, called thermal insulators, that have been found to not transfer this energy very well. Click Here to return to the search form.
In this course, students hone and refine editing skills on a variety of levels. Topics include electronic editing, using electronic resources, dynamics of the editor-writer relationship, editing information graphics, advanced copyediting and developmental editing. Class exercises cover grammar, punctuation, and usage issues. Each student works with a writer to edit and develop an original text. - Acquire an advanced, flexible process that uses editing and revision to develop work. - Able to respond fairly to diverse voices and points of view. - Advanced editorial judgment: able to decide what meets the needs of the readers, writers, and editors for a specific publication, audience, purpose, and situation. - Advanced level of critical thinking skills (analysis, imagination, synthesis, speculation). - Advanced skills in editing for a specific audience, purpose, and situation. - Awareness of basic principles of page layout and design. - Thoroughly understand an editor's roles or types of editing: developmental, acquisition, copy, line, and proofreading. - Understanding how to edit for fairness and accuracy.
In the Southeast, fire ants seem to be everywhere! They become more active during the warmer months and will start their food foraging missions in the spring, continuing into the early fall. Brief History of the Red Imported Fire Ant The Red Imported Fire Ant (RIFA) was brought to the US accidentally in the 1930s through the port of Mobile, Alabama. They’re originally from central South America where they have natural predators which help keep their numbers in check. These ants have no natural predators in the US, so they have spread pretty quickly. There have been attempts to introduce the natural predators from South America, but no real progress has been made on that front. Anatomy and Biology The body of a RIFA is reddish-brown, oval and has two segments in the waist or “pedicel.” Another way to identify a RIFA is through their antennae. Their antennae are different from some other ant species because they are made up of ten segments with the last two forming a club. This ant species ranges in size from 1/8 – 1/4 inches. The size difference indicates what kind of worker they are. Smaller ants are minor workers with the larger ant being major workers. In between those sizes is the media worker, but the majority of ant colonies are made up of minor workers. Their life expectancy changes with respect to their size as well and ranges from 30-180 days. However, RIFA queens have been found to have a life expectancy of 2-6 years! Lastly, RIFA have a nasty stinger at the end of their gaster that can deliver a powerful sting. The venom they release is a type of alkaloid that exhibits necrotoxic (or cell killing) activity. If someone is stung by a RIFA, a burning sensation (hence the name fire ant) will occur, and a white pustule will commonly form at the site of the sting. However, another part of the venom they release into their victim’s system is a mixture of peptides and proteins that are responsible for a lot of people’s allergic reactions. After a colony has developed for a year, they will send out reproductive alates to create new colonies in an event known as mating flights. An alate, in this sense, is a reproductive male or female RIFA with wings. After mating, the males will die soon after, but the females will snap off their wings and will find a place to start a colony. A few females may bunk together right after the mating flight which aids in colony growth, but eventually, only one queen will be left and the others will be killed unless it is a multiple queen colony. New colonies will reach several thousand workers by the time it is six months old, and mature RIFA colonies can reach as many as 240,000 workers! But typically, a colony has about 80,000 members. If the nest is disturbed, the workers will come out in full force and climb vertical surfaces like grass blades and sticks. They’ll sting whatever they can get their mandibles on, too! Since many colonies have multiple queens and are much deeper than they are high above the ground, when the colony is threatened, the queens may split up and leave the colony before any chemical applied to the top of the mound reaches them. This may allow new colonies to form a short distance away from the original mound. Identification and Control One way to tell fire ants apart from other ant species (without a microscope) is the way their nests are structured. Most ant species have one central entrance tunnel. The RIFA, however, has many entrance tunnels. Their nests look like fluffy mounds of dirt with no distinct entryway. Another way you can identify a RIFA colony is through their behavior. With most other ant species, disturbing the nest will rattle the ants and they will come out to defend the nest….eventually. Some ant species may not come out at all. But red imported fire ants will immediately start swarming. They will climb vertical surfaces like grass and sticks, too. Their aggression is a hallmark behavior and should not be experimented with. Don’t intentionally disturb RIFA nests because it can be quite painful for you in the end if they get their stingers on you! If you have an ant problem on your property, indoors or out, call a professional. A licensed pest professional will know the best way to get rid of ants. Their control methods may involve exclusion methods that will get to the root of the problem to fix your ant problems for good.
White-throated sparrows in British Columbia are whistling a new tune and it’s going viral across Canada. What started as a minor change to a common song has now morphed into a continent-wide phenomenon before our very ears. “As far as we know, it’s unprecedented,” says biologist Ken Otter from the University of Northern British Columbia, Canada. “We don’t know of any other study that has ever seen this sort of spread through cultural evolution of a song type.” When Otter first moved to western Canada in the late 1990s, he heard the white-throated sparrows (Zonotrichia albicollis) singing an unusual tune. Instead of sticking to the species’ usual three-note finish, local sparrow populations were ending their tune on two notes. Between 2000 and 2019, this small change has travelled over 3,000 kilometres (1,800 miles) from British Columbia (BC) to central Ontario, virtually wiping out a historic song ending that’s been around since the 1950s at least. No one knows what’s so addictive about this new ending, or why it can’t exist alongside the three-note variant, but scientists are trying to figure it out. Thanks to citizen scientists, researchers were able to analyse the songs of 1,785 male white-throated sparrows, which were recorded from the 1950s onwards. While it’s not unusual for populations of sparrows and other birds to change their tunes, it usually remains a regional dialect. It certainly doesn’t spread like the one from BC. And yet, from Alberta, to Saskatchewan, to Manitoba, this unique ending crossed Canada’s prairie provinces in record time. “It could well be a “we haven’t noticed it before”,” admits Otter to ScienceAlert. “Now that there is so many more songs from vast areas being uploaded each year, it is possible to start exploring whether this is a more general phenomenon in other species.” In 2004, the data show Alberta’s sparrows were still trilling away with the triplet ending typical to the species. Ten years later, all the males in that region had shifted to a doublet ending. By 2015, it had spread to central Ontario, completely supplanting the three-note ending in the northwest. By 2019, it had reached western Quebec, covering the entire western portion of the species’ geographic range. Altogether, that’s a linear distance of nearly 3,300 kilometres. “Within the regions where the doublet-ending song variant spread, it also completely replaced in the process,” the authors write. “To our knowledge, this is an unprecedented rate of song-type transition in any species of birds.” Using citizen science databases, like eBird and Xeno-Canto, the new study shows the songs heard on the wintering grounds tend to match up with where the sparrows are from. “This concentration and intermingling of birds from large portions of the breeding range suggests that the spread of song variants among populations may be facilitated by song tutoring on the wintering grounds,” the authors write. Incidentally, there are reports that the white-crowned sparrows (Z. leucophrys) sometimes incorporates elements of other dialects during winter singing. To test this idea, researchers attached geolocators – or what Otter calls ‘tiny backpacks’ – to 50 male sparrows in British Columbia. They then recovered the devices after the animals had migrated, some to the west and others to the east. Several crossed the Rocky Mountains and entered a new breeding region, which could have feasibly spread the song’s new ending to eastern populations. “We know that birds sing on the wintering grounds, so juvenile males may be able to pick up new song types if they overwinter with birds from other dialect areas,” says Otter. “This would allow males to learn new song types in the winter and take them to new locations when they return to breeding grounds, helping explain how the song type could spread.” Why males end up adopting this new ending is still unclear. Otter says the ending might simply be compelling because it’s unusual and unique. Like many other bird songs, however, it could have to do with females and their preferences. “In many previous studies, the females tend to prefer whatever the local song type is,” says Otter. “But in white-throated sparrows, we might find a situation in which the females actually like songs that aren’t typical in their environment. If that’s the case, there’s a big advantage to any male who can sing a new song type.” And it might be happening again. Researchers are currently watching a new song variant that has suddenly emerged in western sparrow populations and is rapidly spreading. Perhaps this time, we can figure out why. The study was published in Current Biology.
Proteins are important macromolecules made from different amino acids. Amino acids are the building blocks of proteins, and they polymerize into proteins by amide bonds. Some enzymes can break proteins into amino acids, and they are known as proteases. There are different types of proteases that differ according to the mechanism of hydrolysis. Among them, pepsin, which is a gastric protease is one such type. What is Pepsin? Pepsin is an efficient protease enzyme. It hydrolyzes peptide bonds between hydrophorbic and aromatic amino acids such as phenylalanine, tryptophan, and tyrosine, etc. Pepsin has a catalytic aspartic group in its active site. Therefore, it is a gastric protease. Pepsinogen is the inactive form of pepsin. Stomach HCl converts pepsinogen into active pepsin. Under the acidic environment, pepsin cleaves protein compounds into amino acids. Moreover, high alkaline conditions and certain inhibitors can block the pepsin enzyme successfully. What is Protease? Protease is a general term that uses to refer the enzymes that cleave proteins. There are different types of proteases that differ based on the mechanism they use to break proteins into amino acids. Among them, trypsin, pepsin and chymotrypsin are the three main types. The stomach produces pepsins while secretes trypsin and chymotrypsin. These enzymes facilitate the breakdown of the protein component of your diet and enhance the nutrient absorption. Proteases are also known as peptidases, and they can be endopeptidases or exopeptidases. Exopeptidases target cleave sites at the terminals of proteins while endopeptidases target sites within the proteins. What are the Similarities Between Pepsin and Protease? - Pepsin and protease are enzymes that break proteins. - Both are enzymes. - Both Pepsin and protease can break polymers into smaller units. What is the Difference Between Pepsin and Protease? Pepsin is a protease, which is the main gastric enzyme. Protease is a general term used to refer to protein-breaking enzymes including pepsin. There are several proteases. Among them, pepsin is an efficient protease that prefers to cleave hydrophobic and aromatic amino acids. The stomach secretes the pepsins, and they work under acidic conditions. The below infographic presents the difference between pepsin and protease in a tabular form. Summary – Pepsin vs Protease Amylase, protease and lipase are the three main types of enzymes that digest our foods into smaller units which can be absorbed readily into the bloodstream. Proteases are the enzymes which break proteins into amino acids. Amongst the several types of proteases, pepsin is one type. The stomach produces pepsin, and it prefers to cleave hydrophobic and aromatic amino acids. Pepsin serves as the main gastric enzyme. 1.“Pepsin.” Egyptian Journal of Medical Human Genetics, Elsevier. Available here 2.Britannica, The Editors of Encyclopaedia. “Proteolytic Enzyme.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 31 May 2018. Available here
Do Moles Eat Hosta Plants? Hostas (Hosta spp.) are the understated stars of the shade garden, producing thick, green foliage and sweet-smelling flower spikes in U.S. Department of Agriculture plant hardiness zones 3 through 9, depending on species. Pests can be a problem, but usually it's slugs and snails driving gardeners mad -- few complain of mole damage to their tough hosta plants. Moles are small mammals in the genus Scapanus. They are not rodents, contrary to popular belief. These brown-gray animals range in size from 4 to 8 inches long, with small eyes and ears and short, powerful claws. The diet of a mole consists mainly of earthworms and white grubs, but they may also consume snail larvae, mature insects, spiders, small vertebrates and the occasional vegetation they come across while digging. Moles spend most of their time underground and rarely surface. They may tunnel deeply underground, building nests and tunnels as far as 20 inches below the surface. They feed primarily inside their tunnels or nests, where they are safe from predation by domesticated dogs and cats, as well as wild predators like skunks and owls. Moles tend to be solitary, only sharing tunnels with their offspring, who may leave the nest around six weeks of age. Damage to Ornamentals Moles can damage ornamentals, but rarely, nibbling on and uprooting bulbs and roots that they come across while digging. They do not exit their tunnels to chew on plants. Moles are considered beneficial by most homeowners until their tunnels become too shallow, causing ridges to form in lawns and disturbing grass along the path. These shallow tunnels are often only temporary nuisances; the moles generally keep to deeper layers of the soil, aerating and mixing them together. If your hostas are being aggressively consumed by a tunneling vertebrate, chances are that the culprit is either a vole or a pocket gopher. These rodent-like pests are notorious for eating a wide range of vegetable and ornamental plants, and even girdling trees. Unless you're watching for them at night, it's unlikely you'll see these pests munching your plants. The best protection for your hostas is to build a fence around them, burying about 2 feet of fence wire underground. With your hostas protected, you can patiently trap the problem animals. - Fine Gardening Plant Guide: Genus Hosta - University of California Statewide Integrated Pest Management Program: Moles - Virginia Cooperative Extension: Managing Wildlife Damage: Moles - University of Missouri Extension: Controlling Nuisance Moles - University of California Statewide Integrated Pest Management Program: Pocket Gophers - University of California Statewide Integrated Pest Management Program: Voles - Jupiterimages/liquidlibrary/Getty Images
This set of touch math multiplication timed tests (0 to 12) was created for those students who use the touch math skip counting strategy to help them with their math facts. This is another free resource for teachers created by The Curriculum Corner. You will find various resources within this post: - Individual (for each number 0 through 12) & Mixed Review (0 to 5, 6 to 10, 0 to 10 and 0 to 12) 25-problem sets – all pages in one download - 100-Problem Mixed Review Pages (0 to 5, 6 to 10, 0 to 10 and 0 to 12) While learning math facts for memory provides students with the foundation and speed for more difficult concepts as they progress, we know that it can be difficult for some students. That is why we have created this specific set of timed tests. Students can use the touch math strategy to skip count quickly for correct answers. Not familiar with the strategy? Here’s a brief description of how it works on these facts: - First your students need to be sure they can skip count quickly and accurately by the number of the set they are working on. So, if they are working on their 8s, they need to be able to quickly count by 8s to 80 (or 96 depending on the level of mastery they are required to learn). - Have them practice this several times until they are fluent in their skip counting. In Jill’s classroom, putting the skip counting to a tune/music for each set was a HUGE help! (Many of her former students have told her they STILL remember these songs as adults!) - Next, students look at the math multiplication fact they are working on and begin skip counting on the OTHER number in the problem. They actually use the tip of their pencil and TOUCH the dots on the other number. For example, if they are working on the fact 8 x 4, they will skip count by 8s ON THE NUMBER 4 by using the dots provided on the number 4 on the timed test. - If a dot is open in the center, it will be “touched” twice with their pencil. (On the numbers 6 through 9, any dot that is not opaque will be touched two times in their skip counting.) - Again, lots of practice is the key to their success in using this strategy on timed tests. We have included three pages for each individual set of facts so that students who are working on the same set can sit next to each other during testing if needed. The touch math multiplication timed tests are in three downloads below. We have provided the tests in both horizontal and vertical forms . NOTE: The 100-problem pages are two pages (to fit all the problems with the touch math font) and will need to be copied two-sided. You will find the links to all three sets of touch math multiplication timed tests here:
What Are Primary Sources? Understanding primary sources helps young people become critical thinkers. After learning about the many different types of primary sources, such as diaries, speeches, oral histories, video clips, photographs, newspaper articles, artifacts, and political cartoons, students will understand that they are able to draw their own conclusions about the content in a historical source. They will become aware of the biases and limitations of voices from and about the past. photographs feature multiple primary sources, while sidebars encourage readers to engage with the text.
The holiday school breaks are over and children are back in school. A child needs many abilities to succeed in school. Good vision is a key. Reading, writing, chalkboard work, and using computers are among the visual tasks students perform daily. A child’s eyes are constantly in use in the classroom and at play. When his or her vision is not functioning properly, education and participation in sports can suffer. As children progress in school, they face increasing demands on their visual abilities. The size of print in schoolbooks becomes smaller and the amount of time spent reading and studying increases significantly. Increased class work and homework place significant demands on the child’s eyes. Unfortunately, the visual abilities of some students aren’t performing up to the task. When certain visual skills have not developed, or are poorly developed, learning is difficult and stressful, and children will typically: - Avoid reading and other near visual work as much as possible. - Attempt to do the work anyway, but with a lowered level of comprehension or efficiency. - Experience discomfort, fatigue and a short attention span. Some children with learning difficulties exhibit specific behaviors of hyperactivity and distractibility. These children are often labeled as having “Attention Deficit Hyperactivity Disorder” (ADHD). However, undetected and untreated vision problems can elicit some of the very same signs and symptoms commonly attributed to ADHD. Due to these similarities, some children may be mislabeled as having ADHD when, in fact, they have an undetected vision problem. Because vision may change frequently during the school years, regular eye and vision care is important. The most common vision problem is nearsightedness or myopia. However, some children have other forms of refractive error like farsightedness and astigmatism. In addition, the existence of eye focusing, eye tracking and eye coordination problems may affect school and sports performance. There are many visual skills beyond seeing clearly that team together to support academic success. Vision is more than just the ability to see clearly or having 20/20 eyesight. It is also the ability to understand and respond to what is seen. Basic visual skills include the ability to focus the eyes, use both eyes together as a team, and move them effectively. Other visual perceptual skills include: - recognition (the ability to tell the difference between letters like “b” and “d”), - comprehension (to “picture” in our mind what is happening in a story we are reading), and - retention (to be able to remember and recall details of what we read). Every child needs to have the following vision skills for effective reading and learning: - Visual acuity — the ability to see clearly in the distance for viewing the chalkboard, at an intermediate distance for the computer, and up close for reading a book. - Eye Focusing — the ability to quickly and accurately maintain clear vision as the distance from objects change, such as when looking from the chalkboard to a paper on the desk and back. Eye focusing allows the child to easily maintain clear vision over time like when reading a book or writing a report. - Eye tracking — the ability to keep the eyes on target when looking from one object to another, moving the eyes along a printed page, or following a moving object like a thrown ball. - Eye teaming — the ability to coordinate and use both eyes together when moving the eyes along a printed page, and to be able to judge distances and see depth for class work and sports. - Eye-hand coordination — the ability to use visual information to monitor and direct the hands when drawing a picture or trying to hit a ball. - Visual perception — the ability to organize images on a printed page into letters, words and ideas and to understand and remember what is read. If any of these visual skills are lacking or not functioning properly, a child will have to work harder. This can lead to headaches, fatigue and other eyestrain problems. Parents and teachers need to be alert for symptoms that may indicate a child has a vision problem. A child may not tell you that he or she has a vision problem because they may think the way they see is the way everyone sees. Signs that may indicate a child has vision problem include: - Frequent eye rubbing or blinking - Short attention span - Avoiding reading and other close activities - Frequent headaches - Covering one eye - Tilting the head to one side - Holding reading materials close to the face - An eye turning in or out - Seeing double - Losing place when reading - Difficulty remembering what he or she read The vision skills needed for successful reading and learning are much more complex than just 20/20 vision. Your child should receive an eye examination every year, or more frequently if specific problems or risk factors exist, or if recommended by your eye doctor. Unfortunately, parents and educators often incorrectly assume that if a child passes a school screening, then there is no vision problem. However, many school vision screenings only test for distance visual acuity. A child who can see 20/20 can still have a vision problem. In reality, the vision skills needed for successful reading and learning are much more complex. Even if a child passes a vision screening, they should receive a comprehensive optometric examination if: - They show any of the signs or symptoms of a vision problem listed above. - They are not achieving up to their potential. - They are minimally able to achieve but have to use excessive time and effort to do so. Vision changes can occur without your child or you noticing them. Therefore, your child should receive an eye examination every year, or more frequently if specific problems or risk factors exist, or if recommended by your eye doctor. The earlier a vision problem is detected and treated, the more likely treatment will be successful. When needed, the doctor can prescribe treatment including eyeglasses, contact lenses or vision therapy to correct any vision problems. Come in and see us for a comprehensive eye exam and discuss personalized options for your eyes. Dr. Patrick Utnehmer, Promenade Optometry & Lasik, (951) 296-2211.
by Stephen Rogers For many years beginning in the early 1980s, collection managers in Carnegie Museum of Natural History’s Section of Birds began keeping a spread wing and sometimes a tail for many of the skeletons we produced. The rational was that there were two sets of wing bones, and sacrificing one side to produce a spread wing and sometimes also a tail (not sacrificing the pygostyle), would produce a reference item that could be used to examine molt, verify identity, and as reference for morphology and artists who use the collection. Above is an example of a spread wing and tail and the other corresponding wing parts from the other side of the wing. This photo was sent to a person wishing to have measurements of the pollex bone and the length of the alula—in this case we could provide measurements from the same individual. The pieces of tissue on the wing can also be used to supply dried tissue for DNA. We did not and, even now, do not preserve tissue in ethanol or liquid nitrogen. Usually dried toe-pad material is used to get DNA when tissue is not available, but if we did not save skins of the specimens collected, a piece of tissue from the wing can be used. Another use of these specimens has been the extraction of wax like material that birds apply from the uropygial gland to keep the bird feather waterproof. One researcher extracted these chemicals from spread wings which was easier than doing so from study skins—dipping the feathers into a solution to dissolve off the material and running it through a gas chromatograph. Stephen Rogers is a collections manager at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.
Three-dimensional view of Hurricane Floyd as it approached landfall at Cape Fear on September 16, 1999. Results were obtained from a forecast made using the dynamical Hurricane Prediction System developed at NOAA's Geophysical Fluid Dynamic Laboratory (GFDL). The model correctly forecast the path of Floyd up the East Coast of the United States. In the figure, winds in excess of gale force are indicated by the magenta and white arrows at the surface and top of the storm, respectively. The color shading at the earth's surface represents the precipitation , with red indicating higher intensities. The gray three-dimensional "cloud-like"? feature is the 80% relative humidity surface, cut away on its eastern side to reveal the hurricane's interior structure, including the tube-like eye down the center. The horizontal plane slicing through the middle of the storm, and the red vertical arrows, indicate the upward motion in the storm's interior. Note the north-south asymmetry of the storm, as Floyd gets swept up in the larger-scale southwesterly flow. Image credit: NOAA/GFDL.
Rome was a society built on slavery. After the fall of Rome slavery gradually disappeared in Euope. The peasants of the feudal system were similar in many ways to slaves, but Christian theology based on the value of individual souls did not support slavery and as a result slavery gradually disappeared in Europe. With the European explosion into foreign lands in the 16th century there was a revival of slavery. There was slavery permitted in colonies which became race based. This was in part justified by denying the essential humanity of the enslaved people. A major debate occurred in Spain over the issue of whether the Native Americans were human. Similar attitudes were directed at Africans although there was never any formalized legal debate. There were, however, still some remants of both slavery and slave trading. In addition, the Mongols and Ottoman Turks conquered large areas of southern and eastern Europe. There was also Arab slave trading into Europe, Rome was a society built on slavery. After the fall of Rome slavery gradually disappeared in Euope. Slavery was central to the Roman economy, perhaps more so than any other ancient civilization. Slavery was a minor institution in the early years of the Republic. This gradually changed as Rome expanded through conquest. Slaves were were primarily war captives, both captured wariors and the women and children of conquered populations. The offspring of these enslaved people provided a vast slave work force. The victors in battle might enslave the losers rather than killing them. Slavery in Rome were major components of the work force. The performed virtually every occupation required in the Romn economy. The citize farmer was the bed-rock of the early Republic. Gradually farming with the influx of slaves shifted to estate slavery which relied on chain gangs to work the fields. Large numbers of slaves were also used to work the mines, commonly under atrocious conditions under brutal overloads. Slaves were also employed as servants and artisans in the cities. Slaves working as domestics in private houshold had the best opportunity to engratiate themselves with their masters and perhap earn their freedom. Slaves were drawn from widly differing peoples and there was no association with race. Slaves might be blond, blue eyed Anglo-Saxons from Britania or blacks from Sahara as well as evry other racial type. Slavery in Rome had no racial basis. Even those of Italian stock were enslaved. It was thus impossible to tell from one's physical appearance if one was a slave. It was only the Western Empire that fell (5th century). The Eastern or Buzantine Empire survived for another 1,000 years. There was a sizeable slave population in Byzantium. There were both "infidel" and "heathen" slaves. There were also important slave markets in Byzantium. Slavery in Byzantium and the Byzantine Mediterranean had its own unique chracter and was distinct in many ways to the slavery practiced in America, including law, the labor market, medieval politics, and religion. [Rotman] Byzantium had to deal with the Islanic outburst and the power of first the Islamic Caliphate and then the Ottoman Empire. The term slavery can include widely different social system. Gradually the Byzantines shifted cultural perception of slaves as individuals. Increasingly the Byzantines viewed slaves as human beings and persons rather than mere property. After the fall of Rome, the Feudal system developed in Europe. The Feudalism was an economic, social, and economic system based apportionment of land in exchange for the provision of fealty and service. The system was based on the king granting land to his important noblemen who became barons. These land grants became heritary. The king also granted land to the Church. These nobels in exchange pledged loyally to the king and to provide soldiers and supplies in time of war. The great nobels in turn divied their fiefdom among lesser lords or knights who became his vassals. This system ws based on the laborof the lowest rung of the social order. Most Europeans were peasant farmers working on the land of a Feudal nobleman--the lor of the manner. They did not own their land, but allowed to work it in exchange for a hare of the crop and labor when required. As the Feudal system developed, the peasants or serfs became tied to the land, not allowed to leave it without permission of the lord of the manner. The Feudal system began to weaken in Western Europe by the 16th century, but persisted much longer in Eastern Europe. The serfs in Russia werenot legal freed until the 19th century and it was not until the Revolution in the 20th century that the still essentially Feudal estates were broken up. The peasants or serfs of the feudal system were similar in many ways to slaves, but Christian theology based on the value of individual souls did not support slavery and as a result slavery gradually disappeared in Europe. Slavey n Europe declined during the medieval slavery. This was because just as in Egypt and other ancient civilizations, the status of te peasantry was very close to slavery. Sefs were not slaves, but they were also not fee persons. Their status varied from place to place and over time. The slavery of the Romsan Empire was replaced with the serfdom of medieval Europe. A factor here ws the Church which did not approve of slavery, at least for Christian subjects. f course the Vikings were non-Christians and part of the allure of the Viking raids (9th-10th century) was to capture Christians that could be sold as slsaves. Among Christians, there was no prohibition on holding Muslims, Jews, and other non-Chtistians as slaves. And this was the case as late as the 15th century when Europe was beginning its maritime outreach (15th century). By this time slavery had virtually disappeared in northern Europe where it came to be seen as backward and uneconomic. As the feudal system declined in northern Europe (England, the Low Lands, northern France, and northern Germany), the system of free labor and wages became increasingly accepted. This was not the case in the principal Muslim power--the Ottoman Empire. Here slavey was an important part of the economny and social system. It was also practiced in the Barbary states which. And as late as the 15th century, the African slave trade accross the Sahara and Indian Ocean still greatly exceed the Africans being captured by the Portuguese in the Atlantic. [Thomas] The Barbary states also seized Christains ships and raided increasingly prosperous Europe for booty, including taking captives to be sold as slaves. Slaves unlike northern Europe were still important in southern Europe, especially Spain and Portugal. A major factor here was the wars between Cht\ristian and Muslim states. But not all slaves in the Iberian Pensinsual were captured Muslims and Africans. There are reports of Eastern Europeans (Bosnians, Circasians, Poles, and Russians). The Slavs were psartiulsarly important. Note that the word slave has developed from "slav" and not the old Roman (Latin) word "servus". There were active slave amekes in what would become Spain (Barcelona and Valencia) as well as Genoa and Naples. [Verlinden] With the European explosion into foreign lands in the 16th century there was a revival of slavery. There was slavery permitted in colonies which became race based. This was in part justified by denying the essential humanity of the enslaved people. A major debate occurred in Spain over the issue of whether the Native Americans were human. Similar attitudes were directed at Africans although there was never any formalized legal debate. With the fall of Rome (5th century) there were still many non-Christian people in Europe. And indeed most of the Germanic invaders who overwealmed the Empire were pagans. Most of these pagan peoples condoned slavery and some even conducted raids to obtain slavery. St. Patrick was a Briton taken by pgan Irish raiders. There were, however, still some remants of both slavery and slave trading in medieval Europe. The Moors brought slavery back to the Iberian Peninsula (8th century). The Scandinavian raiders better known as the Vikings enslaved captives taken in the West (9th century). The Vikings that moved east into Russia sold captives into slavery to the Ottomns. The Mongols captured arge areas of Eastern Europe (13th century). The Ottoman Turks conquered large areas of south and eastern Europe (14th century). The Moors brought slavery back to the Iberian Peninsula (8th century). There wee slaves of Slavic origin in Al-Andalus. They were supplied by Vikings/Varangians who captured them. Some were assigned to the Caliph's guard and over time acquired important posts in the his army. They became known as "saqaliba". They played an important role in the civil war within the Western Caliphate. Medieval reports describe long columns of slaves moving from northern Europe beyond the Carolingian Empire through the Rhône valley and over the Pyrenees to supply slave markets in Cordoba, Seville, and Grenada. The Scandinavian raiders better known as the Vikings enslaved captives taken in the West (9th century). The Vikings that moved east into Russia sold captive Slavs into slavery to the Ottomns and Arabs. Viking merchants operating in the Volga did a brisk business in slaves with Muslim merchants. The Mongols captured arge areas of Eastern Europe (13th century). Slavery is an ancient central to the ecomonies of many ancient societies. This did not change with the coming of Islam and subsequently the rise of the Ottoman Empire. Slavery as an institution is recognized and thus sanctioned by the Holy Koran. The Koran consuls fair treatment of slaves, but slavery is sanctioned by Sharia Law. Thus approved by both religion and custom, slavery became an important institution in both the Ottoman economy and society. It was not as important as in some societies, but it was important. Slavery was entrenched in the operation of the Ottoman state in both administrative and militiary areas. [Erdem, p. 18.] Slavery was was a central element in the harem system as part of the use of slave domestics and concubines. Slavery was an important aspect of the private lives of individuals in the Muslim areas of the Empire. This was much less true in the Christian areas (primarily the Balkans) where slavery had largely disappeared by the time of the Ottoman conquest. The source of slaves varied over time. Both the Crimean Tartars and the Arabs played an important role in the Ottoman slave trade. The famed Janissary soldiers of the Ottoman Empire were in fact children of Christian parents who were made the Sultan's slaves.The Ottoman Turks conquered large areas of south and eastern Europe (14th century). Christian boys were taken from their families to serve as slaves of the caliph. They were well treated and educated. Some served in administrative posts. Others made up the famed Janisaries. Christian slaves were reported in Asian countries from the earlies phases of the Caliphare. It is often not clear where they were obtained. In the early years it would have been from the Middle East which until the Arab conquest was largely Christian. Later as the Middle East was Imlamicized, Christians would have had to come mostly from Europe. Non-Muslim slaves were valued in Arab harems. They served as both harem girls, but also other roles such as gate-keeper, servant, odalisque, musician, dancer, and court dwarf). Non-Muslims were required for these roles because Islamic law did not allow Muslim boys to be castrated for such service. This was, however acceptable for Christians and other non-Muslims. the Caliph Al-Amin in Baghdad is reported to have owned approximately 7,000 black African eunuchs (who were completely emasculated) and 4,000 white eunuchs (who were castrated). [Lewis] The later would have been mostly European Christians castrated as young boys. Of course many did not survive the operation. There was also Arab slave trading into Europe. This is not a well-examined historical phenomenon, but there is considerable historical evidence confirming that North African Muslim leaders sponsored or tolerated slave raids along the mediterranean coasts of Christian Europe. Some were even reported as distant as the British Isles and Iceland. The best known of these Arab slave raiders were the Barbary pirates. They were noted for seizing European merchant ships, but conducted land raids as well. These raids occurred during the Medieval period, but are not well documented. More is know about the 17th and 18th centuries, mostly as a resultv of naritives left by captives who survived. The raiders were motivated both by profit and Islam. The captives were enslaved and often worked and perished in appalling conditions. They reprtedly died in huge numbers. One way of surviving was to convert to Islam. One fascinating account was left by Thomas Pellow, an 11-year old Cornish cabin boy. [Milton] European countries negotiated treaties with the Barbary states, in essence paying tribute. This caused aproblem when America achieved its independence (1783). The Barbary pirates began seizing American ships, no longer covered by their treaty with America. The result was an American naval expedition to North Africa. Slaves were also transported into the Arab world through Central Asia caravan routes. This was the origins of the Egyptian Mamaluks. The word apparently meant slave in Arabic. They were first introduced to Egypt by Fatimite caliphs (10th century). The Ayyubite caliphs continued the practice. Some of these slaves were used to form military units, some obtaining elite rank and eventually seized control of the state. I have noted various descritions such as "Turkish slaves". This seems to mean slave taken or purchased by the Turks, mostly Europeans of Christian origins. Thids is a topic tht requires further investigation. Lewis, Bernard. Race and Color in Islam (1979). Milton, Giles. White Gold: The Extraordinary Story of Thomas Pellow and Islam's One Million White Slaves . Thomas, Hugh. The Slkave Trade (Lonmdfon, 1977). Rotman, Youval. Jane Marie Todd, trans. Byzantine Slavery and the Mediterranean World Verlinden, Charles. L'Esclavage dans l'Europe médiévale Vol. I (Bruges, 1955). This is an excellent discussion of Spanish and Italian slavery during the medieval period. Navigate the Boys' Historical Clothing Web Site: [Return to the Main slavery page] [Return to the Main working page] [Introduction] [Activities] [Biographies] [Chronology] [Clothing styles] [Countries] [Bibliographies] [Contributions] [Essays] [FAQs] [Glossaries] [Images] [Links] [Registration] [Tools] [Boys' Clothing Home]

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