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Extraction and purification of total RNA RNA, for ribonucleic acid, is a nucleic acid that is chemically similar to DNA. It is a polymer of nucleotides consisting of a ribose sugar, a phosphate and bases such as adenine, guanine, cytosine and uracil. It is found in all living things and also in some viruses. RNA plays an essential role in gene expression by acting as a temporary carrier of genetic information. RNA acts as an intermediary between the genetic information encoded by DNA and proteins. But it also has other functions such as the regulation of gene expression, enzyme catalysis and enzyme guidance. The term total RNA encompasses the three main types of RNA: messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA). The mRNA represents 5% of total RNA, it carries the genetic code copied from the DNA and serves as a temporary carrier. Ribosomal RNAs are found in ribosomes and represent 80% of total RNAs. The rRNAs combine with proteins and enzymes in the cytoplasm of the cell to form ribosomes, which act as a site for protein synthesis. These complex structures move along the mRNA molecule during translation. Transfer RNA is the smallest of the 3 types of RNA and its main role is the transfer of amino acids during protein synthesis. Search result : 3 product found Refine your search : RUOCE / IVD - kit 3 - PCR 2 Price Bef. VAT
Domestic pigs (Suidae sus domestica), is a sub-species of the Suidae sus species, which also includes the wild boar. Because of their cultivation by humans, domestic pigs are the most plentiful variety of pig worldwide. Domestic pigs are intelligent and adaptable, and their ability to thrive unattended in wild conditions has led to the existence of populations of feral, or wild pigs in areas where they have either escaped from their owners or been intentionally left to breed wild. 16-th Century European explorers often left small herds of pigs on islands along their routes, knowing that they could rely on the resulting wild population for fresh meat when they returned to the area. Pigs are omnivores, and are famed for their ability and willingness to eat or try to eat nearly anything. In the wild, they forage mainly for roots, leaves, grasses, acorns and nuts, and fruit. This generality of diet has led domestic pigs to be universally used for food waste disposal by their owners. They are primarily raised for meat and leather, and their hairs can be used as bristles, to make brushes. Because of their success as foragers and their excellent sense of smell, pigs are also used to hunt for truffles, and a few small breeds have sometimes been used as house pets, though this can become problematic, as even the smallest breeds will grow to 200+ pounds (90+ kilograms). Pigs are well known for rolling enthusiastically in mud and dirt. They do this to cool themselves and protect their skin from the sun--pigs have no sweat glands, and are unable to cool themselves effectively by panting, as dogs do.
Ear infectionsOtitis media An in-depth report on the causes, diagnosis, treatment, and prevention of ear infections. Middle ear (otitis media) infections are very common in young children. They include: Acute otitis media (AOM)is an inflammation caused by bacteria that travel to the middle ear from fluid trapped in the Eustachian tube. Children with AOM exhibit signs of an ear infection including pain, fever, and tugging at the ear. Otitis media with effusion (OME)refers to fluid that accumulates in the middle ear without obvious signs of infection. OME usually produces no symptoms. But some children will have difficulty hearing or complain of "plugged up" ears. Other types of ear-related infections include external ear infections (otitis externa) such as swimmer's ear, or masteoiditis, whis is usually a complication of severe AOM. Preventing colds and influenza ("flu") is the best way to prevent ear infections. Make sure children wash their hands frequently and receive an influenza vaccine annually and the recommended series of pneumococcal vaccinations. No one should smoke around children, since exposure to second-hand tobacco smoke can increase the risk for middle ear infections. Breastfeeding for a baby's first 6 months can help protect against ear infections. - Antibiotics are effective treatment for acute otitis media. However, many ear infections resolve without antibiotic treatment. - For most children with AOM, doctors recommend waiting 48 to 72 hours before prescribing antibiotics. However, children younger than 6 months should receive immediate antibiotic treatment. Parents can give children 6 months and older ibuprofen or acetaminophen to help relieve pain. - Antibiotics are not helpful for most cases of OME. Doctors usually monitor children with OME for 3 months to see if their condition improves. Some children with hearing loss and developmental problems may eventually need surgery. Inserting tubes into the ear drum (tympanostomy) is the usual surgery for this problem. The ear is the organ of hearing and balance. It has 3 parts: the outer, middle, and inner ear: - The outer ear collects sound waves, which move through the ear canal to the tympanic membrane, commonly called the eardrum. - The middle ear is filled with air that surrounds a chain of three tiny bones. These bones vibrate to the rhythm of the eardrum and pass the sound waves on to the inner ear. - The inner ear is filled with fluid. Here, hair-like structures stimulate nerves to change sound waves into electrochemical impulses that are carried to the brain, which senses these impulses as sounds. The inner ear also functions as the body's gyroscope, regulating balance. - The Eustachian tube runs from the middle ear to the passages behind the nose and the upper part of the throat. This tube helps equalize the air pressure in the middle ear to the outside air pressure. Problems here are primary factors in most cases of ear infection. The ear consists of external, middle, and inner structures. The eardrum and the three tiny bones conduct sound from the eardrum to the cochlea. Middle Ear Infections (Otitis Media) in Children Acute Otitis Media (AOM) An inflammation in the middle ear is known as "otitis media." AOM is a middle ear infection caused by bacteria that has traveled to the middle ear from fluid buildup in the Eustachian tube. AOM may develop during or after a cold or the flu. With AOM: - Middle ear infections are extremely common in children younger than 3. But they are infrequent in adults. - In children, ear infections often recur, particularly if they first develop in early infancy. - AOM symptoms improve within 48 to 72 hours with or without antibiotic treatment in most children. There does not appear to be any risks for at least 2 to 3 days. - Even after symptoms subside, fluid may persist in the middle ear for weeks to months after AOM onset. Otitis Media with Effusion (OME) OME occurs when fluid, called an effusion, becomes trapped behind the eardrum in one or both ears. In chronic and severe cases, the fluid is very sticky and is commonly called "glue ear." With OME: - Fluid is present. But there is no infection. - There is usually no pain. Sometimes the only clue that it is present is a feeling of stuffiness in the ears, which can feel like "being under water." - Hearing may be temporarily impaired in children. But most children will not have long-term hearing loss. Chronic Otitis Media This condition refers to persistent perforation or hole in the tympanic membrane. It is called chronic suppurative otitis media when there is persistent pus-like drainage inflammation in the middle ear or mastoids (the rounded bone just behind the ear). There may also be a chronic rupture of the eardrum with either ongoing drainage that is not infected or a dry eardrum with a perforation but no drainage or infection. Other chronic changes may result from severe acute infections, recurrent infections, or a chronic infection. These changes include bone erosion, erosion and changes in the ossicular bones behind the eardrum, or scarring of the eardrum and middle ear compartment. These problems often lead to chronic hearing loss. Other Types of Ear Infections Swimmer's Ear (Acute Otitis Externa) Acute otitis externa is an inflammation or infection of the outer ear and ear canal. It can be triggered by water that gets trapped in the ear. The trapped water can cause bacteria and fungi to breed. Otitis externa can also be precipitated by overly aggressively scratching or cleaning of ears or when an object gets stuck in the ears. Otitis externa should be treated with topical antibiotics, which will cure the infection and help relieve pain. With eardrops, most cases will clear up within 2 to 3 days. If the condition persists, the doctor will need to evaluate and rule out other possible causes. Acute otitis media (middle ear infection) is usually due to a combination of factors that increase susceptibility to bacterial and viral infections in the middle ear. The primary setting for middle ear infections is in a child's Eustachian tube, which runs from the middle ear to the nose and upper throat. The Eustachian tube is shorter and narrower in children than adults, and more vulnerable to blockage. It is also more horizontal in younger children and therefore does not drain as well. Children with abnormally short and relatively horizontal Eustachian tubes are at particular risk for ear infections. Many bacteria normally thrive in the passages of the nose and throat. Most are not harmful. However, certain types of bacteria commonly cause ear infections. They are: - Streptococcus pneumoniae (also called S. pneumoniae or pneumococcus) is the most common bacterial cause of acute otitis media, causing about 40% to 80% of cases in the U.S. - Haemophilus influenzae, the next most common bacterium, is responsible for 20% to 30% of acute infections. - Since the introduction of the pneumococcal conjugate vaccine, the U.S. frequency of S. pneumoniae infections tended to decrease, while that of H. influenzae infections tended to increase. S. pneumoniae is still the leading microorganism to cause otitis media worldwide. Moraxella catarrhalis is responsible for 10% to 20% of infections. - Other bacteria include Streptococcus pyogenes and (rarely) Staphylococcus aureus. Viruses play an important role in many ear infections, and can set the stage for bacterial infections. Rhinoviruses are the common viruses that cause colds. While rhinoviruses themselves do not cause ear infections, if a cold does occur the virus can cause the membranes along the walls of the inner ear passages to swell and obstruct the airways. If this inflammation blocks the narrow Eustachian tube, the middle ear may not drain properly. Fluid builds up and becomes a breeding ground for bacteria and subsequent infection. Other viruses, such as respiratory syncytial virus (RSV, a virus responsible for childhood respiratory infections) and influenza (flu), can be the actual causes of some ear infections. Nearly a third of infants and toddlers with upper respiratory infections go on to develop acute otitis media. Evidence suggests that both viruses and bacteria play a role in ear infections. Viruses can increase middle ear inflammation and interfere with antibiotics' effectiveness in treating bacterial causes of ear infections. HIV or other viruses that weaken the immune system can increase the risk for ear infections. Congenital structural abnormalities, such as cleft palate, increase the risk for ear infections. Genetic conditions, may also increase the risk. For example, in Kartagener's syndrome the cilia (hair-like structures) in the middle ear and Eustachian tube are immobile and cause fluid buildup. Children with Down syndrome or fetal alcohol syndrome may also be at increased risk due to anatomical abnormalities. In the United States, ear infections are the most common reason why children see the doctor. Acute Otitis Media (AOM) AOM generally affects children ages 6 to 18 months. The earlier a child has a first ear infection, the more likely they are to recurrent episodes. About two-thirds of children will have a least one attack of AOM by age 3, and a third of these children will have at least three episodes. Boys are more likely to have infections than girls. As children grow, the structures in their ears enlarge and their immune systems become stronger. By age 16 months, the risk for recurrent infections rapidly decreases. After age 5, most children outgrow their susceptibility to ear infections. Otitis Media with Effusion OME is very common in children age 6 months to 4 years, with about 90% of children having OME at some point. More than half of children have OME by age 2. Other Risk Factors Ear infections are more likely to occur in the fall and winter. The following conditions also put children at higher risk for ear infection: Upper respiratory infections.Upper respiratory infections (URIs) such as the common cold often precede and increase the risk for ear infections. Allergies.Allergies do not cause ear infections. But they can cause inflammation and fluid buildup in the ears, which may contribute to ear infections. Enrollment in day care.Although ear infections themselves are not contagious, Children who have close and frequent exposure to other children in group settings such as day care and preschool are at increased risk for catching colds and other upper respiratory infections. Having siblings with recurrent ear infections also increases risk. Exposure to second-hand cigarette smoke.Parents who smoke increase the risk that their children will develop middle ear infections. Bottle-feeding.Babies who are bottle-fed, especially when lying down, may have a higher risk for otitis media than breastfed babies. The American Academy of Pediatrics recommends breastfeeding for at least the baby's first 6 months. Pacifier use.Pacifiers may increase the risk for ear infections. Sucking increases production of saliva, which helps bacteria travel up the Eustachian tubes to the middle ear. Obesity.Obesity may increase the risk for OME. Hearing Loss and Speech or Developmental Delay Severe cases of recurrent acute otitis media (AOM) or persistent otitis media with effusion (OME) may impair hearing for a period of time. But the hearing loss is not substantial or permanent for most children. Hearing loss in children may temporarily slow down language development and reading skills. However, uncomplicated chronic middle ear effusion generally poses no danger for developmental delays in otherwise healthy children. Rarely, patients with chronic otitis media develop involvement of the inner ear. In these situations hearing loss can potentially be permanent. Most of these patients will also have problems with vertigo (dizziness). Tympanic membrane (eardrum) perforation (hole) In some cases, the eardrum may rupture under the pressure from buildup of fluid. This can occur from both AOM and OME and usually heals without treatment. However chronic perforations require surgical treatment. Chronic suppurative otitis mediaP. aeruginosaS. aureus Physical and Structural Injuries in the Face and Ears Serious complications or permanent physical injuries from ear infections are very uncommon, but may include: Structural damage.Certain children with severe or recurrent otitis media may be at risk for structural damage in the ear, including erosion of the ear canal. Cholesteatomas.Inflammatory tissues in the ear called cholesteatomas are an uncommon complication of chronic or severe ear infections. Calcifications.In rare cases, even after a mild infection, some children develop calcification and hardening in the middle and, occasionally, in the inner ear. This may be due to immune abnormalities. Before the introduction of antibiotics, mastoiditis (an infection in the bones located in the skull region behind the ears) was a serious, although rare, complication of otitis media. The condition is difficult to treat and requires intravenous antibiotics and drainage procedures. Surgery may be necessary. If pain and fever persist in spite of antibiotic treatment of otitis media, the doctor should check for mastoiditis. If an infection of the mastoid air cells cannot be controlled with antibiotics, surgery may be needed. Other Possible Complications If the infection spreads to the inner ear patients may experience vertigo, tinnitus, nausea, nystagmus, and hearing loss. Labyrinthitis most often occurs with chronic suppurative otitis media or cholesteatomas. In rare cases, bacteria from a severe ear infection can spread to the tissues surrounding the brain. Very rarely, a child with acute otitis media may develop facial paralysis, which is temporary and usually relieved by antibiotics or possibly drainage surgery. Facial paralysis may also occur in patients with chronic otitis media and a cholesteatoma (tissue in the middle ear). Surgery is usually needed to correct this condition. You should contact the pediatrician if your child has any of the following signs of ear infection: - Severe ear pain or mild pain that has lasted more than 2 days - Fever higher than 102.2°F (39°C) - Intense redness of the eardrum - Any drainage (fluid, pus, blood) from the ear canal Symptoms of Acute Otitis Media Ear pain is the most common symptom of ear infections. The ear pain associated with acute otitis media usually comes on very suddenly. Babies and young children who haven't yet learned to speak may express ear pain in various ways including: - Pulling, tugging, rubbing, or holding the ear - Excessive crying, especially when feeding (sucking and swallowing can increase pressure in the ear) - Irritability, fussiness, and other changes in behavior - Difficulty sleeping - Loss of appetite Other symptoms associated with ear infections include: - Fluid discharge from ear - Cold symptoms such as nasal congestion, runny nose, or coughing (because upper respiratory infections often precede or accompany ear infections) If the ear infection is severe, the tympanic membrane may rupture, causing the pus to drain from the ear. (This usually brings relief from pain.) Pus in the ear may cause hearing loss in some children. Symptoms of Otitis Media with Effusion OME may have no symptoms at all. Some hearing loss may occur, but it is often fluctuating and hard to detect. The only sign to a parent that the condition exists may be when a child complains of "plugged up" hearing. Other symptoms can include loud talking, not responding to verbal commands, and turning up the television or radio. Older children with OME may have difficulty targeting specific sounds in a noisy room. In such cases, some parents or teachers may attribute their behavior to lack of attention or even to an attention deficit disorder. Older children and adults may also notice a sense of fullness in the ear. OME is often diagnosed during a regular pediatric visit. Symptoms are not reliable in themselves for diagnosing ear infections. Ear pain, ear tugging, irritability, fussiness, and similar symptoms may be due to ear infections or they may be caused by unrelated health conditions (colds, other infections, teething). Specific physical signs that a doctor must identify to diagnose acute otitis media (AOM). They include: - Moderate-to-severe bulging of the eardrum (tympanic membrane) or fluid discharge from the ear - Mild bulging of the eardrum and recent (less than 48 hours) onset of pain or intense redness - Signs of fluid buildup in the middle ear (middle ear effusion) as confirmed by pneumatic otoscopy or tympanometry tests AOM (fluid and infection) is often difficult to differentiate from OME (fluid without infection). It is important for a doctor to make this distinction because OME does not require antibiotic treatment. This is why the new guidelines recommend that doctors use a pneumatic otoscope during the physical exam to get a clearer picture of the eardrum's appearance. During an ear examination, the doctor will first remove any ear wax (called cerumen) in order to get a clear view of the eardrum. The doctor will then use a procedure called - Pneumatic otoscopy can detect how easily the eardrum moves in response to changes in pressure. If the eardrum does not move easily, this is a sign that there is fluid present. - The otoscope is a flashlight-like instrument with a magnifying lens to help the doctor get a clear picture of the eardrum. The otoscope has a rubber bulb attachment that the doctor presses to push air into the ear. - The doctor gently inserts the otoscope into the ear canal and presses the bulb to release a puff of air. By observing the action of the air against the eardrum, the doctor can evaluate the eardrum's movement. - The procedure is very quick and is usually painless. An otoscope is a tool that shines a beam of light to help visualize and examine the condition of the ear canal and eardrum. Examining the ear can reveal the cause of symptoms such as an earache, the ear feeling full, or hearing loss. The pneumatic otoscope is considered the standard tool for diagnosis of middle ear infections. Another procedure that is used is called - With tympanometry, a small probe is held to the entrance of the ear canal and forms an airtight seal. - While the air pressure is varied, a sound with a fixed tone is directed at the eardrum and its energy is measured. - Tympanometry can detect fluid in the middle air and also obstruction in the Eustachian tube. - A procedure similar to tympanometry, called reflectometry, also measures reflected sound. It can detect fluid and obstruction, but does not require an airtight seal at the canal. Neither tympanometry nor reflectometry are substitutes for the pneumatic otoscope, which allows a direct view of the middle ear. Parents can also use a sonar-like device, such as the EarCheck Monitor, to determine if there is fluid in their child's middle ear. EarCheck uses acoustic reflectometry technology, which bounces sound waves off the eardrum to assess mobility. When fluid is present behind the middle ear (a symptom of AOM and OME), the eardrum will not be as mobile. The device works like an ear thermometer and is painless. Results indicate the likelihood of the presence of fluid and may help patients decide whether they need to contact their child's doctor. On rare occasions the doctor may need to draw fluid from the ear using a needle for identifying specific bacteria, a procedure called tympanocentesis. This procedure can also relieve severe ear pain. It is most often performed by an ear, nose, and throat (ENT) specialist, and usually only in severe or recurrent cases. In most cases, tympanocentesis is not necessary in order to obtain an accurate enough diagnosis for effective treatment. Determining Hearing Problems Hearing tests performed by an audiologist are usually recommended for children with persistent otitis media with effusion. A hearing loss below 20 decibels usually indicates problems. Determining Impaired Hearing in Infants and Small Children Unfortunately, it is very difficult to test children under 2 years old for hearing problems. You may observe a baby's reaction to sound. For example, sudden noises will startle most newborns, and by 6 months, most babies should turn their head or their eyes toward sound. One other way to determine hearing problems in infants is to gauge the baby's language development: - At 4 to 6 weeks most babies with normal hearing make cooing sounds. - By around 5 months, infants should be laughing out loud and making one-syllable sounds with both a vowel and consonant. - Between 6 to 8 months, babies should be able to make word-like sounds with more than one syllable. - Usually starting around 7 months, and by 10 months, babies babble (making many word-like noises). - Around 10 months, babies can identify and use some term for a parent, such as dada, baba, or mama. - Babies speak their first word usually by the end of their first year. If a child's progress is significantly delayed beyond these times, a parent should suspect possible hearing problems. Determining Impaired Hearing in Older Children Hearing loss in older children may be detected by the following behaviors: - Not responding to speech spoken beyond 3 feet away - Difficulty following directions - Limited vocabulary - Social and behavioral problems The best way to prevent ear infections is to prevent colds and flu. The American Academy of Pediatricians recommends that all children receive the pneumococcal vaccine (PCV13) and an annual flu shot. Influenza ("Flu") Vaccine The American Academy of Pediatrics (AAP) and the U.S. Centers for Disease Control (CDC) recommend annual influenza vaccination for all children over 6 months of age. Preventing the flu (influenza) is an important protective measure against ear infections. Flu vaccines are typically given by injection, usually between October and December. The earlier your child receives the vaccine, the earlier the immunity to the flu will take effect. It usually takes about 2 weeks for antibodies to the influenza virus to develop. These antibodies provide protection against the virus. A nasal spray form of the flu vaccine is approved for children ages 2 years and older. This intranasal vaccine is made from a live but weakened influenza virus (live attenuated influenza vaccine, LAIV); flu shots use inactivated (not live) viruses. Children younger than 2 years old, and children younger than age 5 who have asthma or recurrent wheezing, should not receive this intranasal vaccine. Side effects of the flu shot are generally mild but may include soreness at the injection site, low-grade fever, or body aches. These side effects usually go away on their own within a few days. Side effects of the nasal flu vaccine in children can include runny nose, wheezing, vomiting, muscle aches, and fever. Pneumococcal Conjugate Vaccine The pneumococcal conjugate vaccine (PCV13) protects against 13 of the most important strains of S. pneumoniae that cause pneumococcal meningitis, pneumococcal pneumonia, and other respiratory infections. It also protects against many of the bacteria that cause middle ear infections. PCV13 is specifically approved to help prevent invasive pneumococcal disease and otitis media. The recommended schedule of pneumococcal immunization is four doses, one each given at 2, 4, 6, and 12 to 15 months of age. Side effects of the pneumococcal vaccine are usually mild, but may include: - Loss of appetite - Soreness at the injection site Cold and flu viruses spread when an infected person coughs or sneezes. These viruses can also be transmitted by shaking hands. Everyone should always wash their hands before eating and after going outside. Ordinary soap is sufficient. Waterless hand cleansers that contain an alcohol-based gel are also effective. Antibacterial soaps add little protection, particularly against viruses. Wiping surfaces with a solution that contains one part bleach to 10 parts water is very effective in killing viruses. Breastfeeding offers protection against many early infections, including ear infections. Mother's milk provides immune factors that help protect the child from infections. Also, infants are held during breastfeeding in a position that allows the Eustachian tubes to function well. If possible, new mothers should breastfeed their infants for at least 4 to 6 months. According to the American Academy of Pediatrics, exclusively breastfeeding for a baby's first 6 months helps to prevent ear and other respiratory infections. For improving protection for bottle-fed babies, do not lay the baby down with the bottle ("bottle propping"). Hold the infant in the same way you would to breastfeed. Avoiding Exposure to Cigarette Smoke No one should smoke around children. Studies indicate that children who live with smokers have a significantly increased risk for ear infections. Treatment for Acute Otitis Media (AOM) Most cases of AOM clear up on their own within a week and do not require antibiotic treatment. (Antibiotics are necessary for children with special health concerns, and infants younger than 6 months.) Doctors often recommend a "watchful waiting" period for the first 48 to 72 hours after symptoms appear, to see if ear pain and other symptoms resolve on their own. For antibiotic treatment, the latest recommendations are: - Children younger than 6 months of age should receive immediate antibiotic treatment. - Children 6 months or older should be treated for pain within the first 24 hours with either acetaminophen (Tylenol, generic) or ibuprofen (Advil, generic). Pain relievers -- not antibiotics -- are the main drugs used for AOM treatment. - For children, aged 6 months to 2 years old, antibiotic treatment is recommended for either severe symptoms or for non-severe symptoms that have not improved within 48 to 72 hours. Severe AOM symptoms include moderate to severe pain and a fever of at least 102.2°F (39°C). - For children older than 2 years, and those with mild symptoms or infection only in one ear, watchful waiting is recommended. - Preventive antibiotics are not recommended for recurrent acute otitis media. Ear tube (tympanostomy) insertion are an option for children who have had at least 3 occurrences of AOM in 6 months or 4 episodes in a year. However, newer guidelines strongly advise that tympanostomy tube surgery should be used only for children who have middle-ear effusion (fluid behind the eardrum) and not for children with frequent AOM infections. Parents can help reduce risks for ear infections by breastfeeding for the baby's first 6 months, avoiding bottle propping, avoiding exposure to second-hand tobacco smoke, and making sure their children receive vaccinations for pneumococcal disease and influenza. Treatment for Otitis Media with Effusion (OME) Otitis media with effusion (OME) is fluid behind the middle ear (eardrum). It usually resolves on its own without treatment, especially when it follows an acute ear infection. Antibiotics are not helpful for most cases of OME. Clinical practice guidelines for OME recommend the following treatments: Watchful Waiting for OME.The child is typically monitored for the first 3 months. (Most cases of OME resolve within 3 months.) If OME lasts longer than 3 months, a hearing test should be conducted. Even if OME lasts for longer than 3 months, the condition generally resolves on its own without any long-term effects on language or development. The doctor will re-evaluate the child at periodic intervals to determine if there is risk for hearing loss. Drug Treatment.Antibiotics, decongestants, antihistamines, and corticosteroids do not help and are not recommended for routine management of OME. Antibiotic ear drops are helpful for treating ear infections that may occur in children with tympanostomy tubes. Topical antibiotics (ear drops) work better than oral antibiotics (pills) for treating the discharge that can occur with this type of infection. Surgery.Ear tube insertion may be recommended when fluid builds up behind your child's eardrum and does not go away after 3 months or longer. Fluid buildup may cause some hearing loss while it is present. However, most children do not have long-term damage to their hearing or their ability to speak even when the fluid remains for many months. Children with persistent OME lasting longer than 3 months should get a hearing test. Children may be candidates for ear tube (tympanostomy) insertion surgery if they have: - OME in one or both ears for at least 3 months. - Hearing difficulties and OME in both ears for at least 3 months. - Symptoms caused by persistent OME (balance problems, poor school performance, behavioral issues, or reduced quality of life). - OME and risk for developmental problems for conditions such as Down syndrome, autism, or cleft palate. - Children who have persistent OME and do not receive tubes should be reevaluated every 3 to 6 months until the fluid is no longer present, hearing loss is detected, or structural damage is suspected. Insertion of tympanostomy tubes into the eardrum is the first choice for surgical intervention. Adenoidectomy (removal of adenoids) plus myringotomy (removal of fluid), with or without tube insertion, is sometimes recommended as a repeat surgical procedure. (Myringotomy alone is not recommended for OME treatment. Adenoidectomy is not recommended as an initial procedure unless some other condition (chronic sinusitis, nasal obstruction, adenoiditis) is present. Tonsillectomy (removal of tonsils) is not recommended for OME treatment. Home Remedies for Ear Pain Before antibiotics, parents used home remedies to treat the pain of ear infections. Now, with current concern over antibiotic overuse, many of these simple remedies are again popular: - Parents can press a warm water bottle or warm bag of salt against the ear. Such old-fashioned remedies may help to ease ear pain. - Due to the high risk of burns, ear candles should not be used to remove wax from ears. These candles are not safe or effective for treatment of ear infections or other ear conditions. - Researchers are studying the protective value of probiotics ("good" bacteria) especially lactobacilli strains such as acidophilus. But it is important not to give your child any herbal remedies or dietary supplements without consulting with the pediatrician. Pain Relief Medications A number of pain relievers are available to help relieve symptoms: - Acetaminophen (Tylenol, generic) and ibuprofen (Advil, generic) are the main pain relievers recommended for children. - Eardrops containing anesthetics are also available by prescription. They provide short-acting pain relief and may help children endure ear discomfort until an oral pain reliever takes effect. Parents should check with a doctor before using them. Eardrops could cause damage in children who have a ruptured eardrum. Note: Aspirin and aspirin-containing products are not recommended for children or adolescents. Reye syndrome, a very serious condition, is associated with aspirin use in children who have chickenpox or flu. Cold and Allergy Remedies Decongestants (pills or nasal sprays or drops), antihistamines, or combination products are not recommended for AOM or OME. Recent research has questioned the general safety of cough and cold products for children. They are currently banned for use in children under age 4 years. The American College of Chest Physicians recommends against the use of nonprescription cough and cold medicines in children age 14 years and younger. A simple technique called the Valsalva's maneuver is useful in opening the Eustachian tubes and providing occasional relief from the chronic stuffy feeling that accompanies otitis media with effusion. It may also be useful for unplugging ears during air travel descent. It works as follows: - The child takes a deep breath and closes the mouth. - The child then blows the nose gently while, at the same time, pinching it firmly shut. - The parent should be sure to instruct the child not to blow too hard or the eardrum could be harmed. Do not use this technique if an infection is present. Precautions when Swimming Swimming can pose specific risks for children with current ear infections or previous surgery. Water pollutants or chemicals may worsen the infection, and underwater swimming causes pressure changes that can cause pain. The following precautions should be taken: - Children with ruptured acute otitis media (drainage from ear canal) should not go swimming until their infections are completely cured. - Children with AOM that is not ruptured should not dive or swim underwater. - Children with implanted ear tubes can usually safely swim, bathe, or engage in water sports without needing earplugs or other precautions. Deciding When Antibiotics Should Be Prescribed Pain relievers such as ibuprofen or acetaminophen are the main drug treatments used for ear infections. Doctors want to avoid prescribing antibiotics unless they are absolutely needed. Your child's doctor may recommend watchful waiting for the first 48 to 72 hours after symptoms appear, to see if ear pain and other symptoms resolve on their own. The latest guidelines from the American Academy of Pediatrics recommend antibiotics for the following otherwise healthy children who have acute otitis media: - Children younger than age 6 months - Children age 6 months and older who have had severe pain for at least 48 hours or have a temperature higher than 102.2°F (39°C) - Children age 6 months and older who have mild ear pain that worsens or does not improve within 48 to 72 hours - Children age 6 months to 2 years who do not have severe symptoms or fever but who have AOM in both ears Duration of Antibiotic Treatment If a child needs antibiotics for acute otitis media, the drugs should be taken for the following periods of time: - A 10-day course of antibiotics is usually recommended for children younger than 2 years of age, and for those with severe symptoms. - A 7-day course is recommended for children 2 to 5 years of age with mild or moderate AOM. - A 5 to 7 day course is recommended for children 6 years of age and older with mild-to-moderate symptoms. Parents should be sure their child finishes the entire course of therapy. Response to Antibiotic Treatment Your child's symptoms, including fever, should improve within 48 to 72 hours after beginning antibiotics. If symptoms do not improve it may be because a virus is present or the bacteria causing the ear infection is resistant to the prescribed antibiotic. A different antibiotic may be needed. In some children whose treatment is successful, fluid will still remain in the middle ear for weeks or months, even after the infection has resolved. During that period, children may have some hearing problems, but eventually the fluid almost always drains away. If your child fails to improve and middle ear fluid remains, your doctor may recommend consultation with an ear, nose, and throat specialist (otolaryngologist). This specialist may perform a tympanocentesis procedure in which fluid is drawn from the ear and examined for specific bacterial organisms. But this is reserved for severe cases. Specific Antibiotics Used for Acute Otitis Media Amoxicillin, a penicillin type of antibiotic, is generally recommended for first-line treatment of AOM. The combination drug amoxicillin-clavulanate is an alternative option. Children who are allergic to penicillin drugs will be prescribed a different antibiotic. Children who do not respond within 48 to 72 hours to initial treatment with amoxicillin may be given a course of amoxicillin-clavulanate or ceftriaxone. Alternative treatments are ceftriaxone or clindamycin, which may also be accompanied by a different cephalosporin antibiotic. Side Effects of Antibiotics - The most common side effects of nearly all antibiotics are gastrointestinal problems, including cramps, nausea, vomiting, and diarrhea. - Allergic reactions can occur with all antibiotics, but are especially common with penicillin drugs. These reactions can range from mild skin rashes to rare but severe, even life-threatening, anaphylactic shock. - Some drugs, including certain over-the-counter medications, interact with antibiotics. Parents should tell the doctor about all medications their child is taking. Tympanostomy (with Myringotomy) Tympanostomy surgery involves the insertion of a tiny tube to prevent fluid from building up in the middle ear. These ear tubes (also called tympanostomy tubes) allow air to flow into the middle ear and help prevent infections caused by fluid accumulation. The procedure involves: - A general anesthetic (asleep, no pain) is given first. Children typically recover completely within a few hours. - Myringotomy (removal of fluid) is performed next. - After myringotomy, the doctor inserts a tube to allow continuous drainage of the fluid from the middle ear. Tympanostomy is a simple procedure, and the child almost never has to spend the night in the hospital. Acetaminophen (Tylenol, generic) or ibuprofen (Advil, generic) is sufficient for any postoperative pain in most children. However, some children may need codeine or other powerful pain relievers. Generally, the tubes stay in the eardrum for 6 to 12 months before coming out on their own. Less commonly, long-term tubes are implanted that need to be surgically removed. Children with ear tubes can usually swim and bathe normally, and do not need to wear earplugs. Otorrhea, drainage of secretion from the ear, is the most common complication after surgery and can be persistent in some children. This discharge can be treated with antibiotic eardrops. More serious complications from the operation are very uncommon, but may include: - General anesthetic risks. Rarely, allergic reactions or other complications, such as throat spasm or obstruction, may occur. The risk is highest in children who have other medical conditions, most commonly upper respiratory infections, lung disease, or gastroesophageal reflux disorder (GERD). Anesthetic-related risks are nearly always easily treated. - Tube blockage. Sometimes the tubes become blocked from sticky secretions or clotted blood after the operation. - Eardrum perforation. This condition occurs when the eardrum does not close after the tubes have come out. It is the most common serious complication, but it is very rare. - Scarring can also occur, particularly in children who need more than one procedure. But it almost never affects hearing. - Cholesteatomas, small cyst-like masses filled with keratin (skin cells), develop around the tube site in about 1% of patients. Hearing is almost always restored following tympanostomy. Failure to achieve normal or near-normal hearing is usually due to complicated conditions, such as preexisting ear problems or persistent OME in children who have had previous multiple tympanostomies. Persistent fluid is the main reason for continued impaired hearing. Only a small percentage of hearing loss cases can be attributed to complications of the operation itself. Eventually, the tubes fall out as the hole in the eardrum closes. This may happen after several months or more than a year later. It is painless. In fact, the patient and parents may not even be aware that the tubes are out. About 20% to 50% of children may have OME relapse and need additional surgery that involves adenoidectomy and myringotomy. Tube reinsertion may be recommended for children younger than 4 years of age. Myringotomy is used to drain the fluid and may be used (with or without ear tube insertion) in combination with adenoidectomy as a repeat surgical procedure if initial tympanostomy is not successful. It is not effective as a sole surgical procedure. Myringotomy involves the following steps: - The surgeon makes a very small incision in the eardrum. - Fluid is sucked out using a vacuum-like device. - The fluid is usually examined for identifying specific bacteria. - The eardrum heals in about a week. Adenoids are collections of spongy lymph tissue in the back of the throat, similar to the tonsils. Removal of the adenoids, called adenoidectomy, is usually considered only for OME if a pre-existing condition exists, such as chronic sinusitis, nasal obstruction, or chronic adenoiditis (inflammation of the adenoids). Unless these conditions exist, adenoidectomy is not recommended for treatment of OME. Adenoidectomy plus myringotomy (removal of fluid) may be performed if an initial tympanostomy (tube insertion) procedure is unsuccessful in resolving OME. This combination procedure works best in children ages 4 years or older. Tube insertion alone is recommended for children under 4 years of age. It is not necessary to perform an adenoidectomy along with tube insertion for children under 4 years of age. Laser-assisted myringotomy is a technique that is being investigated as an alternative to conventional tympanostomy and myringotomy. At present, there is not enough evidence to say whether it is as good as ear tubes, the standard procedure. Some clinical trials have suggested that the success rate for laser-assisted myringotomy is half that of standard tympanostomy/myringotomy. - National Institute on Deafness and Other Communication Disorders -- www.nidcd.nih.gov - American Academy of Pediatrics -- www.aap.org - American Academy of Otolaryngology -- Head and Neck Surgery -- www.entnet.org Casselbrandt ML, Mandel EM. Acute otitis media and otitis media with effusion. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 195. Chole RA. Chronic otitis media, mastoiditis, and petrositis. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 139. Gulani A, Sachdev HS. Zinc supplements for preventing otitis media. Cochrane Database Syst Rev. 2014;29(6):CD006639. PMID: 24974096 www.ncbi.nlm.nih.gov/pubmed/24974096. Harris AS, Elhassan HA, Flook EP. Why are ototopical aminoglycosides still first-line therapy for chronic suppurative otitis media? A systematic review and discussion of aminoglycosides versus quinolones. J Laryngol Otol. 2016;130(1):2-7. PMID: 26584651 www.ncbi.nlm.nih.gov/pubmed/26584651. Hersh AL, Jackson MA, Hicks LA; American Academy of Pediatrics Committee on Infectious Diseases. Principles of judicious antibiotic prescribing for upper respiratory tract infections in pediatrics. Pediatrics. 2013;132(6):1146-1154. PMID: 24249823 www.ncbi.nlm.nih.gov/pubmed/24249823. Klein JO. Otitis externa, otitis media, and mastoiditis. Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 62. Kerschner JE, Preciado D. Otitis Media. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 640. Lieberthal AS, Carroll AE, Chonmaitree T, et al. The diagnosis and management of acute otitis media. Pediatrics. 2013;131(3):e964-e999. PMID: 23439909 www.ncbi.nlm.nih.gov/pubmed/23439909. Mittal R, Parrish JM, Soni M, Mittal J, Mathee K. Microbial otitis media: recent advancements in treatment, current challenges and opportunities. J Med Microbiol. 2018;67(10):1417-1425. PMID: 30084766 www.ncbi.nlm.nih.gov/pubmed/30084766. Robinson CL, Romero JR, Kempe A, Pellegrini C, Szilagyi P. Advisory committee on immunization practices recommended immunization schedule for children and adolescents aged 18 years or younger - United States, 2018. MMWR Morb Mortal Wkly Rep. 2018;67(5):156-157. PMID: 29420458 www.ncbi.nlm.nih.gov/pubmed/29420458. Rosenfeld RM, Schwartz SR, Pynnonen MA, et al. Clinical practice guideline: tympanostomy tubes in children. Otolaryngol Head Neck Surg. 2013;149(1 Suppl):S1-S35. PMID: 23818543 www.ncbi.nlm.nih.gov/pubmed/23818543. Rosenfeld RM, Shin JJ, Schwartz SR, et al. Clinical practice guideline: otitis media with effusion executive summary (Update). Otolaryngol Head Neck Surg. 2016;154(2):201-214. PMID: 26833645 www.ncbi.nlm.nih.gov/pubmed/26833645. Siddiq S, Grainger J. The diagnosis and management of acute otitis media: American Academy of Pediatrics Guidelines 2013. Arch Dis Child Educ Pract Ed. 2015;100(4):193-197. PMID: 25395494 www.ncbi.nlm.nih.gov/pubmed/25395494. Szmuilowicz J, Young R. Infections of the ear. Emerg Med Clin North Am. 2019;37(1):1-9. PMID: 30454772 www.ncbi.nlm.nih.gov/pubmed/30454772. Steele DW, Adam GP, Di M, Halladay CH, Balk EM, Trikalinos TA. Effectiveness of tympanostomy tubes for otitis media: a meta-analysis. Pediatrics. 2017;139(6). pii: e20170125. PMID: 28562283 www.ncbi.nlm.nih.gov/pubmed/28562283. Steele DW, Adam GP, Di M, Halladay CW, Balk EM, Trikalinos TA. Prevention and treatment of tympanostomy tube otorrhea: a meta-analysis. Pediatrics. 2017;139(6). pii: e20170667. PMID: 28562289 www.ncbi.nlm.nih.gov/pubmed/28562289. Tapiainen T, Kujala T, Renko M, et al. Effect of antimicrobial treatment of acute otitis media on the daily disappearance of middle ear effusion: a placebo-controlled trial. JAMA Pediatr. 2014;168(7):635-641. PMID: 24797294 www.ncbi.nlm.nih.gov/pubmed/24797294. van Dongen TM, van der Heijden GJ, Venekamp RP, Rovers MM, Schilder AG. A trial of treatment for acute otorrhea in children with tympanostomy tubes. N Engl J Med. 2014;370(8):723-733. PMID: 24552319 www.ncbi.nlm.nih.gov/pubmed/24552319. Venekamp RP, Burton MJ, van Dongen TM, van der Heijden GJ, van Zon A, Schilder AG. Antibiotics for otitis media with effusion in children. Cochrane Database Syst Rev. 2016;(6):CD009163. PMID: 27290722 www.ncbi.nlm.nih.gov/pubmed/27290722. Venekamp RP, Damoiseaux RA, Schilder AG. Acute otitis media in children. Am Fam Physician. 2017;95(2):109-110. PMID: 28084706 www.ncbi.nlm.nih.gov/pubmed/28084706. Venekamp RP, Sanders SL, Glasziou PP, Del Mar CB, Rovers MM. Antibiotics for acute otitis media in children. Cochrane Database Syst Rev. 2015;(6):CD000219. PMID: 26099233 www.ncbi.nlm.nih.gov/pubmed/26099233. Wallace IF, Berkman ND, Lohr KN, Harrison MF, Kimple AJ, Steiner MJ. Surgical treatments for otitis media with effusion: a systematic review. Pediatrics. 2014;133(2):296-311. PMID: 24394689 www.ncbi.nlm.nih.gov/pubmed/24394689. Review Date: 3/14/2019 Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
What are Mites? Mites are small, often microscopic organisms, and belong to the subclass Acarina (along with ticks) or the class Arachnida (along with spiders). They live in soil, water, fields, woods or houses. Some of them attack plants or animals or humans. Some do not attack (bite) humans, but can trigger allergic reaction resulting in an itchy rash. Many types of mites are harmless for human. Types of Mites Affecting Humans Common mites affecting humans are: - House dust mites - Scabies mites - Itch mites - Demodex mites House Dust Mites House dust mites (Dermatophagoides spp.) are microscopic organisms, living worldwide, all around the year, preferably in moist, poorly ventilated homes, especially on carpets, mattresses, bed lining, pillows, curtains, or on furniture. They do not live only in “dirty houses”, but they thrive readily in dust. They eat skin scales falling from people and animals, fungi, or pollens, but they do not live on the human skin, they do not bite, and they do not transfer diseases. They are harmful only to those, who are allergic to them. Dust mites may cause or aggravate asthma, sneezing, wheezing, runny nose, or atopic dermatitis. How to Prevent Exposure to House Dust Mites? - Avoid having carpets, heavy curtains, soft toys and pets in bedrooms and places where you spend a lot of time - Clean dust from all surfaces, vacuum clean carpets and floor under beds, and change and wash bed lining every week in a hot water (at least 129°F = 54°C). - Stay away during cleaning or changing beds, since during this time and 2-3 hours thereafter, dust mites may float in the air. - Shampoo wash or steam clean carpets at least once a year, preferably in spring. - Prevent pollens to come into your house - Cover bedding with mite resistant covers and use synthetic-filled pillows. - Sensitive children should not sleep close to the floor. - Use HEPA air filters - Avoid using any chemicals for controlling mites, since they themselves may cause allergic reaction Dust mites die when humidity falls under about 60%, so try to keep your home dry. Common household cleaners do not kill dust mites. Human scabies (Sarcoptes scabiei var. hominis) are microscopic mites contracted by prolonged skin-to-skin contact with an infected person (1). Infestation through bed lining is possible, but not common. Anyone can be affected, regardless of hygiene. Scabies appear worldwide and easily spread in crowded communities, like student homes or prisons. Animals do not spread human scabies. Mites burrow in surface layers of the skin and cause the following symptoms: - Tiny, about 1 cm long, S-shaped skin-colored or grayish canals, and red bumpy rash appear between fingers or toes, on inner side of wrists, elbows, or knees, in armpits, over shoulder blades, around waist line, around nipples, on penis, under nails, under rings or watchbands, or anywhere on the body. The head, face, neck, palms, and soles may be affected in children and in those with low immunity, but not in otherwise healthy adults (2). - Intense itch, that is due to allergic reaction to mites, may appear all over the body, especially at night. The person infected for the first time usually starts to itch only 2-6 weeks (up to 2 months) after infection but on subsequent infections, itch appears 1-4 days thereafter (2). - Severe or advanced scabies (crusted or Norwegian scabies) may appear in old people or those with low immunity as moderately itching crusts. They are highly contagious both through skin contact and shared items (1). - Staph infection may appear on sites where the skin was injured from scratching. Diagnosis is made from symptoms or skin scraps investigated under the microscope (performed by dermatologist). Treatment of Scabies Scabicid topical medications such as Permetrhrin cream, or Crotamiton lotion or cream should be applied all over the body from the neck down (in children also to head and face), carefully into each body fold, according to instructions. Nails should be cut short and under-nail spaces cleaned with a tooth-pick. This should treat scabies in most cases. Itch may continue for several weeks despite successful treatment; in this case cream can be applied again after a week to be sure mites are eradicated. Ivermectin pills are effective in both ‘common’ and Norwegian scabies (4). No non-prescribed products have been approved to treat human scabies (4). If itch at fingertips does not go away after treatment, soak fingers or toes in a warm water for some minutes until they get a ‘raisin’ appearance, and then scrap the affected skin containing dead mites away. All individuals who were likely in skin contact with infected persons should be treated at the same time to prevent re-infection. Itch is due to allergic reaction to mites. If itch persist after treating with Elimite Cream, antihistamines, or steroids by mouth can be taken until necessary. Prevention of Scabies To prevent scabies, avoid skin-to-skin contact with infected persons. If you have had scabies, wash your clothes, bed lining and towels used in last three days to prevent re-infection. Clothes that cannot be washed may be sealed for at least 72 hours – all scabies mites or their eggs should die in this time. Thorough cleaning of your living place is not required, though, except in Norwegian scabies. Chiggers (Eutrombicula spp.) are about 1 mm sized, red, hairy mites found in grass or woods. They bite human (or animal) skin and spill saliva into it and then eat dissolved skin particles (5). It is this saliva that causes itchy red welts on the areas with a thin skin, mostly around the ankles, behind the knees or elbows and around the waist line. Human Demodex Mites Human Demodex mites live mainly in oil (sebaceus) glands and hair follicles of eyebrows and eyelashes (but may be found in hair follicles elsewhere on the body). Demodex mites are often present in hair follicles of healthy people without causing any symptoms, but they may cause itchy eyes or itchy eyelids. Other symptoms may include: - Eyelid scaling or redness - Loss of lashes - Dry or red eyes - Blurred vision Diagnosis may be made by finding mites on pulled eyelashes under the microscope. Finding Demodex mites can be a coincidence, though, since they live in the hair follicles of many healthy people. Therapy includes (8): - Luring eyelid margin with ether, proparacaine and 70% alcohol (in doctor’s office) weekly for three weeks - Scrubbing eyelids with diluted baby shampoo (50% water, 50% shampoo) twice daily, and applying prescribed antibiotic ointment overnight - Another regime includes tea tree oil and Macadamia nut oil - Discard used eyelid/eyebrow makeup, and do not use makeup during treatment - Clean bed sheets - Other family members have to be checked - Pets have to be checked (type of Demodex mites that live on dogs is rarely found in human, though)
The Beginning of Biases Attitudes about female behavior start from the moment a baby is swaddled in pink. Girls experience these gender stereotypes to varying degrees throughout their childhood and they become fully institutionalized in our education system. As soon as a girl starts school, she encounters subtle (and sometimes blatant) messages about her academic abilities and future potential. Students of color and those from low-income families face additional biases that limit their opportunity. Even in the elementary school years, girls face barriers that ultimately hinder their achievement, particularly in math and science. These barriers are reinforced throughout middle and high school. As a result, when they enter college, women gravitate toward college majors that prepare them for lower-paying fields, and away from the STEM fields that lead to higher paying jobs. And although women have surpassed men in earning degrees, research shows that women are disproportionally represented in 6 of the 10 lowest-paying college majors, while 9 of the 10 highest-paying majors (all in the STEM fields) are dominated by men. What’s more, female students face sexual discrimination, harassment and assault. A 2011 AAUW survey found 56% of female students experienced sexual harassment. This contributes to higher rates of mental health issues among girls, who are more likely than boys to be depressed or anxious about school performance, appearance, behavior and social interactions. Addressing educational inequality requires an intersectional approach: understanding how discrimination based on race, gender, class, orientation and ability compounds to create additional barriers for many students. A majority of U.S. schools are highly divided by income and race – anchored in a long history of racism, discrimination and segregating school and housing policies. And studies show students in higher-income areas generally have access to higher-quality, better-funded educations. Teaching for Tomorrow To ensure a future of equal opportunity — and equal rewards — in the workforce, we need to start with our educational system. It is critical to remove gender-based barriers that keep not only girls but all students from pursuing their dreams and reaching their potential. Schools must teach with an eye toward tomorrow’s economy: The fastest growing, most well-paid sectors require technology, math and science expertise that many students — especially female students and students of color — are not getting. The education system also needs to support the demand for soft skills, such as problem solving, self-directed learning, communication, collaboration and creativity. The gender pay gap — and the lack of women in leadership roles — are not problems that suddenly surface when women enter the workforce. The roots of the problem run deep and correcting it entails understanding the barriers and biases that begin and persist in our educational system. Crossing the Line: Sexual Harassment at School Deeper in Debt: Women & Student Loans Fast Facts: Early Barriers to Girls & Women in STEM With relatively so few women succeeding in math and science careers, girls have fewer role models to inspire their interest in these fields. Get the facts on how girls and women are held back from pursuing STEM careers. Fast Facts: Women & Student Debt Women hold nearly two-thirds of the outstanding student debt in the U.S. — close to $929 billion. When compounded by interest and the gender pay gap, this is an incredible threat to women’s economic security long past graduation day. Get the facts. Title IX Resources Check out some helpful links to assist you in the fight to support and protect Title IX. Where We Stand: Education & Title IX AAUW supports a strong system of public education that promotes gender fairness, equity, and diversity, including vigorous enforcement of Title IX. Learn more about the specific policy measures we advocate for. Know Your Rights on Campus The rights of students, faculty and staff are protected by law, yet many campuses fail to safeguard against gender discrimination, harassment and assault. Use AAUW’s Legal Advocacy Fund resources to make sure you know your rights. Education Gives Women Dignity Education is everything. Education empowers. Education gives us dignity. Education liberates the girl child. There are lots of ways to get involved with AAUW’s work to advance gender equity. Together, we can make a difference in the lives of women and girls. Sign up to get timely action alerts If you prefer, text “AAUW” to 21333 to get AAUW action alerts via text.
Canada under British rule Inside the Parliament of the Province of Canada in Montreal, 1848 \|Preceded by\|\|French colonial era\| \|Followed by\|\|Post-Confederation era\| \|Part of a series on the\| \|History of Canada\| \|By Provinces and Territories\| Canada was under British rule beginning with the 1763 Treaty of Paris, when New France, of which the colony of Canada was a part, formally became a part of the British Empire. Gradually, other territories, colonies and provinces that were part of British North America would be added to Canada, along with land through the use of treaties with First Peoples (for example, see the Post-Confederation or Numbered Treaties). The Royal Proclamation of 1763 enlarged the colony of Canada under the name of the Province of Quebec, which with the Constitutional Act 1791 became known as the Canadas. With the Act of Union 1840, Upper and Lower Canada were joined to become the United Province of Canada. Later, with Confederation in 1867, the British maritime colonies of New Brunswick and Nova Scotia were joined with the Province of Canada to form the Dominion of Canada, which was subsequently divided into four provinces: Ontario, Quebec, New Brunswick and Nova Scotia. A number of other British colonies, such as Newfoundland and British Columbia, and large territories such as Rupert's Land, initially remained outside the newly formed federation. Over time, the remaining colonies and territories of British North America were joined to Canada until the current geographic extent of the country was reached when Newfoundland and Labrador joined Canada in 1949. Although confederation in 1867 led to an enlarged Dominion with increased autonomy over domestic affairs, Canada still remained a colony within the British Empire and was thus subordinate to the British Parliament, until the enactment of the Statute of Westminster in 1931. This statute recognized Canada as an independent peer coequal with the United Kingdom and thus provided the Parliament of Canada with legislative sovereignty over all federal matters except the power to change the constitutional laws of Canada, which remained under the purview of the Parliament of the United Kingdom. Canada's final vestige of legislative dependence on the United Kingdom was terminated in 1982 with the enactment of the Canada Act, subsequently providing Canada with full legal legislative sovereignty independent of the United Kingdom. - 1 New France under British rule - 2 American Revolution - 3 The War of 1812 - 4 Fur trade - 5 Timber trade - 6 "Responsible government" and the Rebellions of 1837-38 - 7 Lord Durham's report - 8 Act of Union (1840) - 9 British colonies on the northwest coast - 10 Trade with the United States - 11 Confederation - 12 See also - 13 References - 14 Further reading - 15 External links New France under British rule In North America, the Seven Years' War had seen Great Britain conquer all of the French colony of Canada. The war officially ended with the signing of the Treaty of Paris on February 10, 1763. As part of the treaty, France formally renounced its claims to all its North American lands to Britain (of which the French colony of Canada was a part), except Louisiana (which had been instead ceded to Spain), and two islands off the shores of Newfoundland (Saint-Pierre and Miquelon). St. Lawrence valley With the addition of Canada to the British Empire, Britain gained control of a strip of territory along the St. Lawrence River with a population of at least 70,000 francophone Roman Catholics, which was expanded and renamed as the Province of Quebec under the Quebec Act. Although many British people (including the American colonies to the south) hoped the French Canadians would be assimilated this was not the case as distinct rules of governance for Quebec were set out in the Quebec Act such as allowing the French Canadians to retain their Catholic religion and their French system of civil law. The Quebec Act became one of the Intolerable Acts that infuriated the thirteen British colonies in what would become the United States of America. The island colony of Newfoundland had been dominated by the British for a long time before the French finally abandoned their legal claims to the area, and thus an anglophone society had already taken shape prior to the legal transfer of ownership. In Acadia, the British had expelled French-speaking populations in 1755 from Acadia to Louisiana, creating the Cajun population, but this would not be repeated in 1763. In the former French territory of Acadia, the British were confronted by a relatively large and well-established Catholic Mi'kmaq and Wabanaki Confederacy. The British Conquest of Acadia (which included Nova Scotia peninsula, while present-day New Brunswick remained in dispute) happened in 1710, much earlier than in what would become the rest of modern-day Canada. The Mi'kmaq never ceded land to either France or England. The first immigration of Protestants happened in the province with the founding of Halifax. The establishment of Halifax sparked Father Le Loutre's War, which, in turn, led to the British expelling the Acadians from the region during the French and Indian War. As they later captured Cape Breton Island and Prince Edward Island, the policy of expulsion was extended there as well. The few Acadians who managed to return to the area have created the contemporary Acadian society. Once the land was emptied, other settlements were formed by New England Planters. In 1775, American revolutionaries (Patriots) attempted to push their insurrection into Quebec. Support for the Patriot cause was mixed; the clergy and landowners were generally opposed to it, while English-speaking merchants and migrants from the Thirteen Colonies were generally supportive of it. The habitants were divided; in some areas (notably the region between Montreal and Saint-Jean), there was significant support, and militia companies were raised in support of the Patriots by James Livingston. The Patriots laid siege to Fort Saint-Jean, capturing it and Montreal in November 1775. They then marched on Quebec City, where an attempt to take the city on December 31, 1775, failed. Following an ineffectual siege, the arrival of British troops in May 1776 sent the Patriots into retreat back toward Montreal. An attempt against British troops at Trois-Rivières failed, and the Patriots were driven from the province in June. Leaving with the rebel army were about 250 Québécois in two regiments: James Livingston's 1st Canadian Regiment, and Moses Hazen's 2nd Canadian Regiment. Quebeckers living in the forts of the Great Lakes region also massively sided with the Patriots and were instrumental in the taking of the fort by the Patriots. Major Clément Gosselin, Pierre Ayotte, Antoine Paulin, Louis Gosselin, Germain Dionne, Pierre Douville, Edward Antill and Moses Hazen and 747 Quebec militiamen were all in Quebec when they joined the Patriots and defeated the British at Yorktown in 1781. In a key act leading up to the Siege of Yorktown, Louis-Philippe de Vaudreuil, the French-born nephew of Canada's last French governor, the Marquis de Vaudreuil, assisted Bougainville and de Grasse in preventing the British Navy from resupplying or relieving Cornwallis' army in the Battle of the Chesapeake. In Nova Scotia there was some agitation against British rule, largely instigated by Jonathan Eddy and John Allan, migrants from Massachusetts who had settled in the Chignecto Isthmus area near Fort Cumberland (formerly Fort Beauséjour). The only major event of their resistance was the Battle of Fort Cumberland, when Eddy and a combined force of Massachusetts Patriots, Acadians, and aboriginals, besieged the fort in November 1776. The siege was broken and Eddy's forces were scattered when British reinforcements arrived. Eddy and Allan continued to make trouble on the frontier between what are now Maine and New Brunswick from a base in Machias for several years. The Maritime provinces were also affected by privateering, and raids on settlements by privateers in violation of their letters of marque. In notable instances, Charlottetown, Prince Edward Island and Lunenburg, Nova Scotia were subjected to these raids. During and after the Revolution, approximately 70,000 United Empire Loyalists fled the United States. Of these, roughly 50,000 Loyalists settled in the British North American colonies, which then consisted of Newfoundland, Nova Scotia, Quebec, and Prince Edward Island (created 1769). The Loyalists who settled in western Nova Scotia wanted political freedom from Halifax, so Britain split off the colony of New Brunswick in 1784. Quebec was also divided into Lower Canada and Upper Canada under the Constitutional Act of 1791, permitting the 8,000 Loyalists who settled in southwestern Quebec (which became Upper Canada) to have a province in which British laws and institutions could be established. A number of Loyalists that came north after the American Revolution were of African descent including former slaves who had been freed as a result of service to the British and over 2,000 African slaves. In 1793 Upper Canada became the first British jurisdiction to enact legislation to suppress slavery, with the Act Against Slavery being passed allowing for its gradual abolition. The War of 1812 In the War of 1812, the Canadas were once again a battleground, this time between the British and the relatively young United States. During the war, unsuccessful attempts were made by the Americans to invade Upper Canada, after overestimating the amount of support they would receive from Canadian colonists. Many of the inhabitants of Upper Canada (now southern Ontario) were Americans who had very recently arrived in the colony, and some of them did support the invading force; however, the rest of the population was made up of the descendants of Loyalists or the original French colonists, who did not want to be part of the United States. The first American invasion came in October 1812, but they were defeated by General Isaac Brock at the Battle of Queenston Heights. The Americans invaded again in 1813, capturing Fort York (now Toronto). Later in the year, the Americans took control of the Great Lakes after the Battle of Lake Erie and the Battle of the Thames, but they had much less success in Lower Canada, where they were defeated at the Battle of Châteauguay and the Battle of Crysler's Farm. The Americans were driven out of Upper Canada in 1814 after the Battle of Lundy's Lane, although they still controlled the Great Lakes and defeated the British at the Battle of Lake Champlain. In English Canada, it is seen as a victory against American invasions, with heroic legends surrounding many of the participants (such as Isaac Brock and Laura Secord) and battles (especially those in the Niagara Peninsula). For centuries one of the most important economic ventures in North America was the fur trade. This trade, which had been pioneered by the French, came to be dominated by the British as they gained increasing territory on the continent. The main British fur trading posts were located inside of what became the United States (the British were forced to relocate northward as borders were established with the new nation). First Nations were central to the trade as they were the primary fur trappers. The role gave the peoples of many of the First Nations a political voice as, though they were viewed as an underclass, they were too important to simply be ignored. The American Revolution led to intense competition between the British and the U.S. By the 1830s changing fashions in Europe had begun a steep decline in fur prices and an overall collapse in the market. Apart from the economic losses to whites involved in the fur trade, many of the First Nations were devastated, both in terms of economic loss and in terms of loss of influence in local politics. As the fur trade declined in importance, the timber trade became Canada's most important commodity. The industry became concentrated in three main regions. The first to be exploited was the Saint John River system. Trees in the still almost deserted hinterland of New Brunswick were cut and transported to Saint John where they were shipped to England. This area soon could not keep up with demand, and the trade moved to the St. Lawrence River where logs were shipped to Quebec City before being sent on to Europe. This area also became insufficient, and the trade expanded westward, most notably to the Ottawa River system, which by 1845 provided three quarters of the timber shipped from Quebec City. The timber trade became a massive business. In one summer 1200 ships were loaded with timber at Quebec City alone. "Responsible government" and the Rebellions of 1837-38 After the War of 1812, the first half of the 19th century saw the growth of political reform movements in both Upper and Lower Canada, largely influenced by American and French republicanism. The colonial legislatures set out by the Constitutional Act had become dominated by wealthy elites, the Family Compact in Upper Canada and the Château Clique in Lower Canada. The moderate reformers, such as Robert Baldwin and Louis-Hippolyte Lafontaine, argued for a more representational form of government which they called "responsible government". By "responsible," the reformers meant that such a government would be ultimately responsible to the will of the subjects of the colonies, not to authorities in London. The critical move toward responsible government came between 1846 and 1850. In practice it meant that the Executive Council of each colony formulated policy with the assistance of the legislative branch. The legislature voted approval or disapproval, and the appointed governor enacted those policies that it had approved. It was a transition from the older system when the governor took advice from an executive Council, and use the legislature chiefly to raise money. The radical reformers, such as William Lyon Mackenzie and Louis-Joseph Papineau demanded equality or a complete break from British rule and the establishment of a republic. Louis-Joseph Papineau was elected speaker of the colonial assembly in 1815. His attempts at reform were ignored by the British, and in 1834, the assembly passed The Ninety-Two Resolutions, outlining its grievances against the legislative council. Papineau organized boycotts and civil disobedience. The colonial government illegally ordered the arrest of Papineau. The Patriotes resorted to armed resistance and planned the Lower Canada Rebellion in the fall of 1837. British troops in the colony quickly put down the rebellion and forced Papineau to flee to the United States. A second rebellion by the Frères chasseurs of Robert Nelson broke out one year later, but the British put it down as well, with much loss of life and destruction of property. William Lyon Mackenzie, a Scottish immigrant and reformist mayor of York (Toronto), organized the Upper Canada Rebellion in December 1837 after the Patriotes rebellion had begun. Upper Canadians had similar grievances; they were annoyed at the undemocratic governance of the colony, and especially by the corrupt and inefficient Bank of Upper Canada and the Canada Company. On December 4, the rebels assembled near Montgomery's Tavern, where the British troops stationed in the city met them on December 7. The rebels were hopelessly outnumbered and outgunned, and were defeated in less than an hour. Mackenzie escaped to the United States. Lord Durham's report Lord Durham was appointed Governor General of Canada in 1838. He was assigned to investigate the causes of the Rebellions, and concluded that the problem was essentially animosity between the British and French inhabitants of Canada. His Report on the Affairs of British North America contains the famous description of "two nations warring in the bosom of a single state." For Durham, the French Canadians were culturally backwards, and he was convinced that only a union of French and English Canada would allow the colony to progress in the interest of Great Britain. A political union would, he hoped, cause the French-speakers to be assimilated by English-speaking settlements, solving the problem of French Canadian nationalism once and for all. Act of Union (1840) Lord Durham was succeeded by Lord Sydenham who was responsible for implementing Durham's recommendations in the Act of Union 1840 passed on July 23, 1840, by the Parliament of the United Kingdom and proclaimed February 10, 1841. Upper and Lower Canada became, respectively, Canada West and Canada East, both with 42 seats in the Legislative Assembly of the Province of Canada despite Lower Canada being more populated. The official language of the province became English and French was explicitly banned in the Parliament and in the courts. The moderate reformers Louis-Hippolyte Lafontaine and Robert Baldwin fought two successive governors general Sir Charles Bagot and Sir Charles Metcalfe to secure what became known as responsible government. Metcalfe fought to preserve the prerogatives of the Crown and the governor's control over the administration and patronage. He nonetheless had to make some concessions to win support, and the most notable of these was persuading the Colonial Office to grant amnesty to the rebels of 1837-38, and to abandon forced anglicization of the French-speaking population. Lafontaine and Baldwin reintroduced French as an official language alongside English in the Assembly, the Courts and other governmental bodies. Under the progressive Governor General James Bruce (Lord Elgin), a bill was passed to allow the leaders of former Patriote movement to return to their homeland; Papineau returned and for a short time re-entered Canadian politics. A similar bill was passed for the former Upper Canadian rebels. Elgin also implemented the practice of responsible government in 1848, several months after it had already been granted to the colony of Nova Scotia. One noted achievement of the Union was the Canadian–American Reciprocity Treaty of 1855 which sanctioned free trade in resources. However, the achievement must be seen in the wider politics of British North America which had seen the major boundary disputes with the United States settled (see Rush–Bagot Treaty, Treaty of 1818, Webster–Ashburton Treaty, Oregon Treaty), thus easing tensions which for most of the first half of the 19th century had Americans threatening war or retaliation. The Union Act of 1840 was ultimately unsuccessful, and led to calls for a greater political union in the 1850s and 1860s. Support for independence was strengthened by events such as the Battle of Ridgeway, an 1866 invasion into Ontario by some 1500 Irish nationalists which was repulsed largely by local militia. British colonies on the northwest coast Although Spain had taken the lead in the exploration of the northwest Pacific Coast, with the voyages of Juan José Pérez Hernández in 1774 and 1775, by the time the Spanish determined to build a fort on Vancouver Island, the British navigator James Cook had himself visited Nootka Sound and charted the coast as far as Alaska, while British and American traders had begun settling the coast to develop resources for trade with Europe and Asia. In 1793 Alexander Mackenzie. a Scottish born Canadian working for the North West Company crossed the continent and with his aboriginal guides, French-Canadian voyageurs and another Scot, reached the mouth of the Bella Coola River, completing the first continental crossing of North America north of Mexico, missing George Vancouver's charting expedition to the region by only a few weeks. The competing imperial claims between Russia, Spain and Britain were compounded by treaties between the former two powers and the United States, which pressed for annexation of most of what is now British Columbia. With the signing of the Oregon Treaty in 1846, the United States agreed to establish its northern border with western British North America along the 49th parallel. By 1857, Americans and British were beginning to respond to rumours of gold in the Fraser River area. Almost overnight, some ten to twenty thousand men moved into the region around present-day Yale, British Columbia, sparking the Fraser Canyon Gold Rush. Governor James Douglas was suddenly faced with having to exert British authority over a largely alien population. In order to normalize its jurisdiction, and undercut any Hudsons's Bay Company claims to the resource wealth of the mainland, the Crown colony of British Columbia was established August 2, 1858. In 1866, it was united with the Colony of Vancouver Island into the United Colonies of Vancouver Island and British Columbia. By the mid-1850s, politicians in the Province of Canada began to contemplate western expansion. They questioned the Hudson's Bay Company's tenure of Rupert's Land and the Arctic territories, and launched a series of exploring expeditions to familiarize themselves and the Canadian population with the geography and climate of the region. Trade with the United States In 1854, the Governor General of British North America, Lord Elgin, signed a significant trade agreement with the United States on behalf of the colonies. This agreement endured for ten years until the American government abrogated it in 1865. Effective governance of the United Province of Canada after 1840 required a careful balancing of the interests of French and English- speaking populations; and between Catholics and Protestants. John A. Macdonald emerged in the 1850s as a personality who could manage that task. A political conservative, MacDonald forged political relationships and coalitions with George-Étienne Cartier, the leader of powerful French Canadian bleus and George Brown of the more stridently reformist English-Canadian and anti-French "Grits", MacDonald came to realize that Canada's likeliest hope of resisting absorption into the United States was to reform itself into a workable federation. A delegation from the Canadas made its way to a conference being held in Charlottetown in 1864 by representatives from the Maritimes who had intended hold discussions regarding a federation of Nova Scotia, New Brunswick and Prince Edward Island. This conference was followed by a subsequent conference in Quebec City. The Seventy-Two Resolutions from the 1864 Quebec Conference laid out the framework for uniting British colonies in North America into a federation. They were adopted by the majority of the provinces of Canada and became the basis for the London Conference of 1866, which led to the formation of the Dominion of Canada on July 1, 1867. Federation emerged from multiple impulses: the British wanted Canada to defend itself; the Maritimes needed railroad connections, which were promised in 1867; British-Canadian nationalism sought to unite the lands into one country, dominated by the English language and British culture; many French-Canadians saw an opportunity to exert political control within a new largely French-speaking Quebec. Finally, but by no means least significant, were fears of possible U.S. expansion northward in the wake of the end of the United States Civil War. On a political level, there was a desire for the expansion of responsible government and elimination of the legislative deadlock between Upper and Lower Canada, and their replacement with provincial legislatures in a federation. This was especially pushed by the liberal Reform movement of Upper Canada and the French-Canadian rouges in Lower Canada who favoured a decentralized union in comparison to the Upper Canadian Conservative party and to some degree the French-Canadian bleus which favoured a centralized union. Even Queen Victoria was supportive, noting "...the impossibility of our being able to hold Canada, but we must struggle for it; and by far the best solution would be to let it go as an independent kingdom under an English prince." In the end Canada went as a Dominion under the Crown of the United Kingdom itself. It was a fresh start, but not one that was greeted with universal joy. While some envisaged Confederation for the British North American colonies as a way forward together, La Minerve, a newspaper in the new Province of Quebec endorsed the federation because it provided "la seule voie qui nous soit offerte pour arriver à l'indépendance politique." ("the only way offered to us to achieve political independence"). A change of heart toward Confederation was evident in Halifax, Nova Scotia, where the Morning Chronicle newspaper announced on the front page of its July 1, 1867, edition the death of "the free and enlightened Province of Nova Scotia". - HILLMER, NORMAN. "Newfoundland Joins Canada". The Canadian Encyclopedia. Retrieved 2017-06-05. - "Newfoundland and Canada: 1864-1949". www.heritage.nf.ca. Retrieved 2017-06-05. - "Canada: History". Country Profiles. Commonwealth Secretariat. Archived from the original (PDF) on 2007-10-12. Retrieved 2007-10-09. - Jobb, Dean (2005). The Acadians: A people's story of exile and triumph, Mississauga (Ont.): John Wiley & Sons Canada, 296 p. ISBN 0-470-83610-5 - Lacoursière, Jacques (1995). Histoire populaire du Québec, Tome 1, des origines à 1791. Éditions du Septentrion, Québec. p. 270. ISBN 2-89448-050-4. - James W. St. G. Walker, "Blacks" Archived 2007-09-27 at the Wayback Machine., in The Canadian Encyclopedia - Thompson, John Herd; Randall, Stephen J (2008). Canada and the United States: Ambivalent Allies. University of Georgia Press. pp. 19–24. ISBN 0-8203-2403-5. Retrieved 2010-09-01. - Gilman (1992), p. 72–74. - Phillip A. Buckner, The Transition to Responsible Government: British Policy in British North America, 1815-1850 (1985) ch. 4 - "The Durham Report and Its Solutions \| Site for Language Management in Canada (SLMC) – Official Languages and Bilingualism Institute (OLBI)". slmc.uottawa.ca. Retrieved 2017-08-23. - "1841 - The First Election after the Act of Union". www.cbc.ca. Retrieved 2017-08-23. - Margaret A. Ormsby, British Columbia: a History MacMillan Company of Canada, 1971, p. 7-8 - Ormsby, pp 9–11 - Ormsby, p. 89 - Ormsby, p. 130 - Ormsby, p. 148 - Richard Gwyn, John A.: the Man Who Made Us, Random House of Canada Limited, 2007, pp. 174-182 - Gwyn, p. 302 - Gwyn, pp. 323-324 - Paul Romney, Getting it Wrong: How Canadians Forgot Their Past and Imperilled Confederation. (1999), p.78 - Stacey, C.P. British Military Policy in the Era of Confederation, CHA Annual Report and Historical Papers 13 (1934), p. 25. - Gwyn, p. 436 - Armstrong, Frederick H (1985). Handbook of Upper Canadian Chronology. Dundurn Press. ISBN 0-919670-92-X. - Bourinot, John G (1900). Canada Under British Rule 1760-1905. The Project Gutenberg eBook. - Craig, Gerald M Upper Canada: the formative years 1784-1841 McClelland and Stewart, 1963, the standard history online edition - Creighton, Donald. John A. Macdonald (2 vols, Toronto, 1952–55), vol 1: The Young Politician) influential bscholarly biography - Morton, W. L. The Critical Years: The Union of British North America 1857-1873 (Toronto, 1964). - Sweeny, Alastair. George-Étienne Cartier: A Biography (Toronto, 1976) Web Version (ISBN 0-7710-8363-7) - Taylor, Martin Brook; Doug Owram (1994). Canadian History: Beginnings to Confederation vol. 1. University of Toronto Press. ISBN 0-8020-5016-6; Guide to historiography - Wrong, George M. Canada and the American Revolution: The Disruption of the First British Empire (1935) - Wrong, George M; H. H. Langton (1914). The Chronicles of Canada: Volume IV – The Beginnings of British Canada. Fireship Press (2009). ISBN 1-934757-47-0. - Kennedy, W.P.M., ed. (1918). Documents of the Canadian Constitution, 1759-1915. Oxford UP. ; 707pp
Who can imagine a world without a computer and Internet today? It has revolutionized every aspect of our modern life. I have always been curious about when and who invented the first ever computer and began the story of the automated computing machines, that has culminated in the invention of portable laptops and supercomputers of today. The answer to this question is not at all simple, because of two reasons. One reason is that there is no one person, who did it all and figured it out on his own. The credit for the development of the modern computer belongs to many people. The second reason the answer is not so simple is because of the fact that definitions of what constitutes a computer, differ considerably. Here, we talk about the pioneers of the idea of building automated computing machines of various types. Some of the earliest known computing or calculating devices are the abacus, slide rule, Astrolabe, and the Antikythera mechanism. In the following discussion, by 'computer', we mean a programmable contraption, that can provide certain output, after processing raw input, supplied to it. Charles Babbage (1791-1871) designed one of the first automatic calculation machines, called the difference engine or analytical engine. However, he did not build it actually and only theorized its mechanism, which was later verified by building of a working model. The First Programmable Computer The first programmable computer was developed by Konrad Zuse of Germany, between 1936 to 1938. It was the first electric computer, that was binary programmable. The First Electronic Digital Computer The first electronic computer was invented by Professor John Vincent Atanasoff and his student, Cliff Berry. It was called the Atanasoff-Berry computer (ABC for short), and was developed at the Iowa State College, between 1937 and 1942. A close second in the race to develop the first fully electronic digital computer, was the ENIAC (Electronic Numerical Integrator And Computer), conceptualized and developed by J. Presper Eckert, and John Mauchly, between 1943 and 1946, at Pennsylvania University. ENIAC weighed 50 tons, occupied 1,800 square feet and had around 18,000 vacuum tubes installed inside. Needless to say, developing and building it in four years was a superb job. It was used in making the calculations for development of the first Hydrogen bomb. The ENIAC couldn't store programs however, which was remedied by the development of the EDVAC (Electronic Discrete Variable Computer). This successor of the ENIAC could store programs. The first commercially, mass produced computer was the UNIVAC I (Universal Automatic Computer), developed by Remington Rand in 1951. Each of the 46 machines that were sold, used 125 kW of power, 5200 vacuum tubes, and cost more than a million dollars. It was used for vote counting and picking up presidential winners. After the invention of the silicon-based transistor, by John Bardeen, Walter Brattain, and William Shockley in 1947-48 and the development of the microchip, miniaturization of computers was initiated, which made the development of personal computers possible. Today, billions of transistors are carved on a silicon chip to create the brain of the computer, which is the chip. Let me share another bit of information. The inventor of the computer mouse is Douglas Engelbart, who developed the first prototype in 1963. Today, the challenge before scientists and engineers, is developing not just faster programmable computers, but machines that can think for themselves. Yes, I am talking about the challenge of artificial intelligence, which is the next stage in the evolution of computing machines.
When it comes to writing or speaking Korean, many people are sometimes confused on how to use the subject particles ~이/가, ~은/는. I was once very confused too, even after I read books, search online, or asked some of my Korean friends! Even when I thought I’ve gotten the concept right, when people started asking me questions I’ve never considered about, I got confused again..;;; Aha! I did not grasp the concept well enough! So as time passed, I tried to fit all the pieces of puzzle in my mind together, and finally got to see the big picture. What’s a subject particle? Simply say, ~이/가 or ~은/는 act like articles such as ‘a’, ‘the’, ‘an’ in English. In the Korean language’s context, it is used to indicate or emphasise a verb, noun, subject of a sentence. You use ~이/~은 when the last alphabet of preceding word ends with a consonant and ~가/~는 with vowels. Here comes the confusing part. But let me break it down in the way I understood it. There are three main points that differ the usage of ~이/가 and ~은/는. They are listed down with examples in the table below: Basically, the meaning of the sentence differs depending on what kind of situation you are using it in. But the concepts generally revolve around the three as mentioned above. As a heads up, you cannot use ~은/는 more than once in a single sentence. Why? Because you wouldn’t know where is the emphasis of the sentence anymore! However, you can use ~이/가 and ~은/는 in the same sentence such as: 김현중이 축구는 좋아해요. (Kim Hyun Joong likes soccer) The sentence emphasises that it is soccer that Kim Hyun Joong likes, and not others. You use ~이/가 when: - Telling/asking something new to/from the listener. - You want to emphasise on the matter before the subject particle. You use ~은/는 when: - Making a factual statement / restating an information listener already knew. - You want to emphasise on the matter after the subject particle. - Double emphasise the meaning of the sentence. Hope this is easy to be understood! Please feel free to correct if I am wrong in any way or you have any doubts! 🙂 Last but not least…
Phrases like "random acts of kindness" and "pay it forward" have become popular terms in modern society. This could perhaps be best explained by those who have identified a deficiency in their lives that can only be fulfilled by altruism. It seems there are good reasons why we can't get enough of those addictive, feel-good emotions, as scientific studies prove there are many physical, emotional, and mental health benefits associated with kindness. As minds and bodies grow, it’s abundantly clear that children require a healthy dose of the warm-and-fuzzies to thrive as healthy, happy, well-rounded individuals. Patty O'Grady, PhD, an expert in neuroscience, emotional learning, and positive psychology, specializes in education. She reports: Kindness changes the brain by the experience of kindness. Children and adolescents do not learn kindness by only thinking about it and talking about it. Kindness is best learned by feeling it so that they can reproduce it. A great number of benefits have been reported to support teaching kindness in schools, best summed up by the following. Happy, Caring Children The good feelings that we experience when being kind are produced by endorphins. They activate areas of the brain that are associated with pleasure, social connection, and trust. These feelings of joyfulness are proven to be contagious, encouraging more kind behavior (also known as altruism) by the giver and recipient. Acts of kindness help us form connections with others which are reported to be a strong factor in increasing happiness. Greater Sense of Belonging and Improved Self-Esteem Studies show that people experience a "helper's high" when they do a good deed. This rush of endorphins creates a lasting sense of pride, well-being, and an enriched sense of belonging. It's reported that even small acts of kindness heighten our sense of well-being, increase energy, and give a wonderful feeling of optimism and self worth. Increased Peer Acceptance Research on prosocial behavior among adolescents determined that being kind increases popularity and our ability to form meaningful connections with other people. Being well liked is an important factor in the happiness of children and it was demonstrated that greater peer acceptance was achieved through good deeds. Better-than-average mental health is reported in classrooms that practice more inclusive behavior due to an even distribution of popularity. Improved Health and Less Stress There are a number of physical and mental health benefits that can be achieved by being kind. Altruistic actions trigger a release of the hormone oxytocin, which can significantly increase a person's level of happiness and reduce stress levels. Oxytocin also protects the heart by lowering blood pressure and reducing free radicals and inflammation, which incidentally speed up the aging process. Increased Feelings of Gratitude When children are part of activities that help others less fortunate than themselves, it provides them with a real sense of perspective, highlighting their own good fortune. Being generous helps them appreciate what they have, makes them feel useful, and fosters empathy. Better Concentration and Improved Results Kindness is a key ingredient that enhances positivity and helps children feel good about themselves as it increases serotonin levels. This important chemical affects learning, memory, mood, sleep, health, and digestion. Children with a positive outlook have greater attention spans, more willingness to learn, and better creative thinking to improve results at school. Internationally-renowned author and speaker Dr. Wayne Dyer explains that an act of kindness increases levels of serotonin, a natural chemical responsible for improving mood. This boost in happiness occurs not only in the giver and receiver of kindness, but also in anyone who witnesses it. Shanetia Clark and Barbara Marinak are Penn State Harrisburg faculty researchers. They say, "Unlike previous generations, today's adolescents are victimizing each other at alarming rates." They strongly believe that adolescent bullying and violence can be confronted with in-school programs that integrate "kindness -- the antithesis of victimization." Many traditional anti-bullying programs focus on the negative actions that cause anxiety in children. When students are instead taught how to change their thoughts and actions by learning about kindness and compassion, it fosters the positive behavior that's expected and naturally rewarded with friendship. Promoting its psychological opposite is key in reducing bullying to create warm and inclusive school environments. Maurice Elias, Professor at Rutgers University Psychology Department, is also an advocate for kindness in schools. He says: As a citizen, grandparent, father, and professional, it is clear to me that the mission of schools must include teaching kindness. Without it, communities, families, schools, and classrooms become places of incivility where lasting learning is unlikely to take place . . . [W]e need to be prepared to teach kindness, because it can be delayed due to maltreatment early in life. It can be smothered under the weight of poverty, and it can be derailed by victimization later in life . . . Kindness can be taught, and it is a defining aspect of civilized human life. It belongs in every home, school, neighborhood, and society. It's become quite clear that modern education ought to encompass more than just academics, and that matters of the heart must be taken seriously and nurtured as a matter of priority. How do you teach kindness? Has it reduced bullying at your school?
Summary and Keywords The concept of representation is a cornerstone of the field of cultural studies. Representations are symbols, signs, and images used to communicate and construct meaning. They are at stake in a variety of fundamental cognitive processes such as perception and imagination. Language, for instance, is based on a system of representation where words stand for something else, such as an object or an idea. Representations are thus central to the process by which individuals and societies make sense of the world, assign meaning, and delineate norms, rules, and identities. Journalism is a key site of production of representations. Unlike most other fields of cultural production, journalism is grounded in a regime of truth: it claims to represent the world as it is. Scholars interested in representation and journalism have largely opposed those claims. Journalism always involves covering certain events over others. News stories necessarily prioritize certain frames, voices, and contextual information, which creates peculiar kinds of representations. Those representations are constrained by the working conditions of journalists, but they are also shaped by broader political, economic, cultural, and historical contexts. In that sense, journalism creates representations but also reproduces representations that exist elsewhere in society. Because the concept of representation points toward broader social forces involved in meaning construction, it has largely been used to explore the operations of power. Instead of asking “is any given representation true?” cultural studies scholars have been more interested in asking “how do relationships of power, domination, and inequality shape representations?” As a result of its development in the field of cultural studies, the study of representation has largely been oriented towards questions of inequalities and identity, most notably gender, race, ethnicity, and class. With regard to the study of representation and journalism, three broad areas of inquiries are delineated. The first concerns how journalism represents different social groups, places, events, and issues through its coverage. This literature is wide and covers a range of issues in both domestic and international coverage. Most of those studies focus on the linguistic, rhetorical, and visual properties of media texts to deconstruct the ideological operations behind what often appears natural and common sense in the news. Another strand of research looks at similar issues of representation but in the context of journalistic production. In particular, these studies centralize the importance of who makes the news to understand the peculiar representations that journalism ultimately produces. Often relying on surveys, statistical data, or ethnography, these have contributed to an understanding of issues such as gender inequalities and lack of diversity in newsrooms. A final—and more discreet—literature investigates how journalism itself is represented in popular culture. Novels, films, television, commercials, cartoons, art, and video games routinely construct representations of journalism and journalists. These representations play a role in shaping popular mythologies around journalism and its role in society. Access to the complete content on Oxford Research Encyclopedia of Communication requires a subscription or purchase. Public users are able to search the site and view the abstracts and keywords for each book and chapter without a subscription. If you are a student or academic complete our librarian recommendation form to recommend the Oxford Research Encyclopedias to your librarians for an institutional free trial. If you have purchased a print title that contains an access token, please see the token for information about how to register your code.
Viruses are the enigma of the biological world – despite having their own DNA and being able to adapt to their environment and evolve, they are not considered to be alive like cells. In order to reproduce and multiply – a requirement of “life” – a virus must invade a living cell, eject its DNA into that of the cell, and commandeer the cell’s biological machinery. While a virus, essentially, may be nothing more than a dollop of DNA packed into a protective coating of protein called a capsid, the packaging of that DNA is critical. The molecular motors that drive this DNA packaging process, however, have remained almost as enigmatic as the viruses themselves. A better understanding of these motors could be crucial to combating viral infections. Studying molecular motors is the signature work of Carlos Bustamante, a biophysicist who holds joint appointments with Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley, as well as the Howard Hughes Medical Institute (HHMI) and the Kavli Energy NanoSciences Institute at Berkeley. In his latest research, he and a team of collaborators have shed new light on a type of molecular motor used to package the DNA of a number of viruses, including such human pathogens as herpes and the adenoviruses. Their findings also provide the first experimental confirmation of ideas proposed some 30 years ago. “In a study of the DNA packaging motor of the Phi 29 virus, we have demonstrated for the first time that the motor not only exerts force on the DNA but also exerts torque to rotate it,” Bustamante says. “We have further shown that this rotation is necessary for the motor to coordinate the activity of all its subunits during its mechano-chemical cycles. We also discovered that as the capsid fills with DNA, the motor adapts its operation to effectively throttle down and prepare itself to terminate packaging.” Bustamante is the corresponding author of a paper reporting the results of this study in the journal Cell entitled “A Viral Packaging Motor Varies Its DNA Rotation and Step Size to Preserve Subunit Coordination as the Capsid Fills.” Shixin Liu, Gheorghe Chistol, and Craig Hetherington are the lead authors. Co-authors are Sara Tafoya, Aathavan Karunakaran, Joerg Schnitzbauer, Shelley Grimes and Paul Jardine. In the 1970s, scientists proposed that the DNA within the viral capsid organizes as a spool that might require it to rotate relative to the capsid. It was also suggested that the DNA might need to rotate relative to the packaging motor in order to maintain crucial electrostatic contacts. However, until now, scientists lacked the experimental tools to prove or refute these ideas. Bustamante, who is a faculty scientist with Berkeley Lab’s Physical Biosciences Division and UC Berkeley’s Raymond and Beverley Sackler Chair of Biophysics, has been a pioneer in the study of single molecules and molecular motors using optical tweezers and microscopic beads. In this latest effort, he and his collaborators modified their standard two-bead optical-tweezers packaging assay by introducing a third “rotor bead” that enabled them to monitor changes in the angle of the DNA around its axis while simultaneously observing DNA translocation into the viral capsid. “We were able to follow a viral packaging motor in real-time at different stages of its biological task and discover the multiple and specific ways in which the motor’s mechanisms are modified in response to external signals,” Bustamante says. “We showed that by designing carefully controlled experiments, it is possible to learn a great deal about the subtle molecular mechanisms underlying the coordination of various molecular motor components.” The Phi29 virus that was the subject of this study is a bacteriophage of Bacillus subtilis, a bacterium found in soils and the human gut. Its DNA packaging motor complex consists of three coaxial rings through which DNA is threaded into the capsid. The catalytic core of the motor complex is a ring ATPase that consists of five subunits. The Phi29 packaging ATPase is considered a model for ring-shaped molecular motors that are common in living cells and rely on the coordinated action of their subunits to perform crucial biological functions. “In a previous study we showed that the Phi 29 ring motor exhibits an interesting division of labor in that four of the five subunits are the workers that move the DNA into the capsid, and the remaining subunit is the supervisor that regulates the progression of the packaging cycles,” says Liu. “However the mechanism for breaking the symmetry of the ring remained unclear. Our new results point towards a model in which the supervisory subunit is the one that maintains electrostatic contacts with the DNA backbone phosphates through every cycle by rotating the DNA. This special subunit does not normally change its identity from cycle to cycle.” The typical optical-tweezers packaging assay used by Bustamante and his group involves tethering DNA to polystyrene beads and using laser beams as optical tweezers to exert opposing forces on each bead. With the addition of the rotor bead to this assay, the researchers could not only measure pushing and pulling forces but also torque. They discovered that the packing motor has developed a surprisingly sophisticated mechanism that allows it to respond to increasing internal pressure from the encapsidated DNA. “Previously it was generally believed that the filled DNA simply applies a resisting force that works against the power stroke of the motor to slow it down and eventually stop,” Liu says. “We found that the resisting force only makes a minor contribution to the slowing down of the motor. Instead, the motor adapts its step size and amount of DNA rotation to ensure that the same subunit makes specific electrostatic contacts with the DNA backbone phosphates every cycle. Remarkably, this coordination mechanism is maintained throughout the entire packaging process even as the packaging velocity drops by two orders of magnitude.” The ability of the Phi 29 packing motor to adjust its operation to changing conditions, while maintaining its basic scheme of coordination, may be a general design principle for other ring motors as well, the researchers say. “By elucidating the full course of viral DNA packaging, we can better understand packaging energetics and subsequent ejection, which in turn should help us develop more effective strategies to stop or block these motors and find alternative drugs against the viruses they package,” Liu says. “Also, some of the characteristics found in this biological motor could inspire the design of efficient and responsive synthetic machines.” This research was supported in part by the National Institutes of Health and the Howard Hughes Medical Institute. For more about the research of Carlos Bustamante go here
For children ages 6 to 9 years old Montessori education prepares students for life. As educators, we are helping the children to become self-confident, emotionally secure and active global citizens. A Montessori elementary classroom continues the design of combining the three-year age groupings. Being in the same classroom with the same teacher for three years gives the children emotional and social stability upon which they build a strong academic foundation. Students use manipulative materials that allow abstract concepts to be represented in a concrete form. First, in the Primary classroom, children are presented with the concept of our Earth to orient them to the world around them. Then, in the Elementary classroom, children are given lessons on the universe. Dr. Montessori designed the Elementary curriculum, known as Cosmic Education, to appeal to the reasoning mind and imagination. Cosmic Education incorporates the subject areas of math, language, geometry, botany, zoology, history, geography, art and music. Five Great Lessons are presented every year to set the stage for Cosmic Education. These lessons present the creation of the universe, the coming of life on Earth, the coming of human beings, and the invention of language and mathematics. Montessori elementary children are guided to take a key role in their own education. They often have the freedom to choose work partners and topics for study, thereby becoming responsible for their own activities. Children work at their own pace, which allows students to excel or spend more time on a particular topic depending on their skill level. Children with Montessori Elementary education develop a love for and a strong understanding of the world around them.
Excretion in Plants Plants have a different mode of life. Green plants utilize CO2 for photosynthesis which is the metabolic waste product of respiration. Plants excrete their waste matter in a manner different from animals. Excretion in plants depends upon the type of plant. Some plants have vacuoles that accumulate waste and lose it through exocytosis. In deciduous trees wastes are stored in the leaves and are lost when the leaf falls off. Plant cells have large vacuoles, and these can be used for either storage of useful compounds, or the storage of waste substances - often accumulating at concentrations that lead to crystal formation in the vacuole. Plants can also store the waste in leaves that are destined to fall off or die off. Some plants will actively secrete wastes into the soil. Oxygen can be looked upon as a waste product of photosynthesis and carbon dioxide a waste product of respiration; water is a waste product of both. Water will be lost through transpiration. Some of the methods of excretion are as follows: - Gums, resins, rubber and latex are exuded from various parts of the plant body. - Crystals of certain chemical substances are stored in the plant body, e.g. calcium oxalate crystals in the leaf of colocasia, calcium carbonate crystals in the leaf of fig, etc. - Some deciduous plants get rid of excretory matter when the leaves fall. - In the bark and wood part of the trunk, tannin is stored. This makes the wood appear dark. Unlike animals, stored excretory materials do not harm the plants. Saprophytic plants such as Mucor, Rhizopus and Pencillium excrete their wastes by diffusion.
William T. Hark, MD Approximately 100 to 600 people die annually in the United States as a result of lightning. Serious injuries are caused in about 1,000 to 1,500 persons each year. This produces a 25 to 32% mortality rate. Of the survivors, 74% sustain permanent injuries. There are more deaths caused by lightning than any other natural phenomena including floods, hurricanes and tornadoes. These deaths are less well publicized because they are individuals or small groups and not associated with large-scale property damage. People with outdoor occupations or hobbies including storm chasers are at greatest risk. Although no storm chaser has been killed or seriously injured, the risk remains. The current in a lightning bolt is as high as 30,000 Amperes with 1,000,000 or more Volts. The short duration of about 1-100 milliseconds limits, but doesn’t prevent injury. There are several mechanisms of lightning injury. The most severe is a direct strike, either on the victim or on some object the victim is holding such as a golf club, tripod or umbrella. A “side flash” occurs when lightning hits a nearby object and jumps to the victim. Ground current injures the victim when lightning strikes the ground nearby and it spreads to the person. Rarely, people maybe injured or killed indoors while using the telephone or taking a shower. Burns may occur from jewelry, clothing or other heated material. Finally, blunt injury and trauma may occur secondary to the shockwave from a lightning strike or from a resulting fall. Lightning can affect all organ systems, especially the cardiovascular system. The primary cause of death following lighting strike is cardiopulmonary arrest. Changes in the heart rhythm (asystole or heart stoppage) may occur, but the heart will usually quickly resume its normal rhythm. EKG abnormalities are common but generally resolve. A paralysis of the respiratory center is more common and can last much longer than the stoppage of the heart. If artificial respiration is not immediately initiated, the person will die of hypoxia or lack of oxygen. Vascular instability is another type of lightning injury which results in cold, pulse less and mottled extremities. This condition usually resolves over several hours. Central nervous system injuries are common. Transient confusion, paralysis and amnesia are likely. Coagulation of the brain, subdural hematomas or collections of blood surrounding the brain, and bleeding within the brain are possible with direct strikes. Swelling of the brain is another outcome. There may be global brain damage and neurologic devastation secondary to anoxic brain injury if respiratory arrest is not immediately treated. Paresthesias (pins and needles sensations) may affect areas of the victim’s body. Possible chronic sequelae include amnesia, movement disorders, dementia and decreased reflexes. Paraplegia can be secondary to brain or spinal cord injury from lightning strikes. There may also be neuropsychiatric complications such as depression, anxiety, memory deficits, and post-traumatic stress disorder. Burns are another possible effect of lightning. Most lightning burn victims have first or second degree burns. Third degree or full-thickness burns are much less common but can occur associated with metal objects such as jewelry. Lighting can also produce a reddish-brown feathery skin lesion which disappears in a few days. This is an inflammatory response rather than a burn. About one half of all lightning victims will have some type of eye damage, usually corneal injury. The most common serious eye injuries are cataracts which can occur from a few days to several years after the lightning strike. Other eye injuries include retinal bleeding, retinal detachment and optic nerve degeneration. There may also be transient autonomic nerve disturbances which can result in dilated or contracted pupils even without concurrent head injury. The ears are also commonly affected with over 50% of lightning victims having ruptured ear drums. Transient hearing loss and tinnitus affect most survivors of lightning strikes. Chronic ear infections and partial hearing loss occur in 47% of patients with initial ear injury. Vertigo or dizziness has also been reported. The victim of lightning strike may have injury either directly from the lightning strike or from being thrown by the blast. Contusions and fractures may occur along with muscle and ligament tears. In rare cases, a compartment syndrome or swelling within section of an extremity may result from lightning damage requiring a surgical release to prevent further tissue destruction. Avoidance and prevention are the best means of lightning safety. Total avoidance is clearly impossible for storm chasers but risks can be minimized. A good description is given by Dr. Charles Doswell III in his essay on chaser safety. Lighting has about a 50 yard search radius on the ground in an area that a strike will occur. It can strike as much as 10 miles from the rain of a thunderstorm and even when the storm appears to be dissipating. It usually seeks the tallest objects in that area. While chasing, the safest place to be is inside a vehicle with a solid metal top. Outside, don’t be the highest object around or be connected or near anything taller than the surrounding objects. Examples include lone or small groups of trees, power poles, and antennas. Hill tops and exposed areas have great visibility but are dangerous. Holding metal objects such as golf clubs, antennas or umbrellas can increase risk by increasing one’s effective height. Being under a developing rain shaft near a thunderstorm is particularly risky. One should also avoid leaning on metal vehicles or being near metal fences which lead toward the storm. If one feels one’s hair stand on end, immediately crouch on the balls of one’s feet with head down while not touching the ground with one’s hands. The potential victim should not lie flat on the ground. A lightning strike is imminent and this position helps minimize height and exposure to ground current. Usually lightning gives no warning and the sign of hair standing on end is not a reliable warning signal. Some chasers recommend using a tall metal object to produce a "cone of protection." Presumably, lightning will strike the metal object instead of the surrounding ground or storm chasers. The cone extends from the top of the object to the ground in a circle and it starts at an angle of 45 degrees from vertical. Unfortunately, with objects taller than 30 meters, the size of the cone's maximal ground radius will remain fixed at about 30 meters. Of course, this is not perfect, and there are no good scientific studies of the safety of this "cone of protection." The main cause of death is cardiopulmonary arrest. Most victims survive if they receive prompt cardiopulmonary resuscitation. Among storm chasers groups, at least two members should be trained in basic life support or CPR. Two are necessary since a single trained person may be the one struck. Lightning danger and the need for CPR is another reason not to chase alone and CPR is something everyone should know even if not a storm chaser. Storm chasers should also have a CPR mask available and easily accessible in their vehicles. These masks are used for mouth-to-mouth respiration. They are cheap ( about $3.00 to $12.00) and aid in hygiene and in prolonged artificial respiration. If a group of persons are victims of a lightning strike, the normal mass casualty triage protocols are reversed. In this situation, those that appear “dead” should be immediately attended and CPR begun. The person who is moving around or screaming will almost always survive and should not require immediate attention if there are others who appear dead. CPR should be started on those not breathing or without a pulse before an ambulance is called. After a lightning strike, the heart will often resume beating while the respiratory drive will be paralyzed for hours. Prompt CPR may prevent secondary hypoxia, brain damage and death. Artificial respiration may need to be continued for hours but can result in a good outcome. Resuscitation in lightning victims has a higher success rate, even after prolonged administration of CPR. It should be noted that the presence of dilated pupils should not be used as an indication of brain damage because these findings can be induced by the lighting strike without head injury. The victim should also be kept immobilized if not in immediate danger because of the possibility of cervical spinal injury. Finally, lightning victims do not carry an electrical charge and can be touched immediately following a strike. Lighting is a continuing risk to storm chasers. This risk can be minimized with some simple safety measures but not eliminated completely. In the event of a lightning injury, immediately attention and CPR to those that appear “dead” can give them the greatest chance of full recovery. Discussing safety and first-aid including CPR should be done prior to storm chasing to minimize the time before CPR is begun in the rare event of a lightning strike leading to cardiac or pulmonary arrest. 1. Blount BW. Lightning Injuries. American Family Practice 1990;42:405-14. 2. Browne BJ, Gaasch WR. Electrical Injuries and Lightning. Emergency Clinics of North America 1992;10:211-26. 3. Carleton SC. Cardiac Problems Associated With Electrical Injury. Cardiology Clinics 1995;13:263-6. 4. Fontanarosa PB. Electrical Shock and Lightning Strike. Annals of Emergency Medicine 1993;22:378-86. 5. Graber J, Ummenhofer W, Herion H. Lightning Accident with Eight Victims: Case Report and Brief Review of Literature. The Journal of Trauma 1996;40:288-90. 6. Holle, RL., Lopez, RE., and Howard, KW. Safety in the Presence of Lightning. Seminars in Neurology 1995;15:375-79. 7. Krider, PE. Cloud-to-Ground Lightning: Mechanisms of Damage and Methods of Protection. Seminars in Neurology 1995;15:2227-32. Return to Virginia Weather and Storm Links
\|MadSci Network: Earth Sciences\| In a technical sense, it is not true that warmer air "holds" more water vapor than cold air. Actually, it is the temperature of the water vapor itself that governs the amount of water vapor that may be held in the atmosphere. The warmer the water vapor, the greater its maximum vapor pressure. Vapor pressure is the portion of atmospheric air pressure attributable to water vapor. The greater the maximum (saturation) vapor pressure is the greater the capacity of the mixture of air and vapor to hold water vapor. Since the amount of water vapor in the air is quite small compared to the rest of the gases in the atmosphere, the temperature of the water vapor is governed by the temperature of the rest of the air in which it resides. This leads to the somewhat inaccurate but very convenient notion that warmer air holds more water vapor. In order to explain this to 4th graders, we won't differentiate between the notion of vapor pressure versus "air capacity." It is probably sufficient to say that the air is like a sponge. When air temperature increases, that sponge grows a little and the air can hold more water vapor. When air temperature decreases, the sponge shrinks and the air can hold less vapor. Keep in mind though the reality of the situation: If air temperature increases, water vapor temperatures does too. This results in a higher saturation (or maximum) vapor pressure. If there isn't enough vapor in the air to meet the maximum, evaporation occurs as the atmosphere strives to reach balance. If air temperature decreases, the saturation vapor pressure decreases as well. If there is more vapor present than this maximum value can support, the condensation occurs as the atmosphere strives to reach balance. Try the links in the MadSci Library for more information on Earth Sciences.
Therizinosaurus: Therizinosaurus was truly a bizarre dinosaur. It evolved from meat-eating dinosaurs, but became specialized for eating plants. It had a huge stomach for hold plant material as it digested. It had a long neck and a small head, and large arms with gigantic claws. Paleontologists think the claws (which could be over a foot in length) were used to defend against predators. Slow moving Therizinosaurus could not run away from predators, so it must have stood its ground and lashed out with its clawed hands. Therizinosaurus lived in Asia during the Late Cretaceous, although relatives have been found in North America as well. Length: 39 feet long. Height: 20 feet tall. Weight: 5 tons. Time it lived: Cretaceous Period 70-80 million years ago. Fossils found in: Gobi Desert, Mongolia. Diet: Shrubs, foliage, tree bark and other plant matter.
Fish in the Desert? Great Basin National Park is home to one native fish species, the Bonneville cutthroat trout. It also houses four non-native species: Lahonton cutthroat, rainbow, brook and brown trout. These were stocked in the lakes and streams of the South Snake Range until 1986. The native fish came from historic Lake Bonneville, which covered the bottom of Snake Valley to the east of the park thousands of years ago. This lake, which was the size of today’s Lake Michigan, supported several species of fish. At the end of the Ice Age, the lake started drying up and eventually shrank into what is today's Great Salt Lake. Some of the fish found refuge in the streams coming down from the mountains and adapted to life in flowing waters. The fish in these streams survived for thousands of years through droughts, fire, and other events, but eventually they encountered problems. When early settlers and miners came, they wanted to catch fish they were familiar with, so they stocked the streams and lakes with non-native fish. The native fish were not able to handle the extra competition, and in some cases hybridization with and predation by these different species occured. This caused drastic decreases in the Bonneville cutthroat trout's numbers, and in many cases completely eliminated them from their native streams.
What good is half an eye? Evolutionary biologists studying the origins of vision get that question a lot, and new research out of UC Santa Barbara points to a possible answer. Findings appearing today in the journal BMC Biology indicate that, even in the absence of eyes altogether, some creatures display a light-sensitivity that uses the same visual pathway that allows humans to see. Todd Oakley, professor in UCSB's Department of Ecology, Evolution, and Marine Biology, co-authored the paper about the genetic behavior of hydra, a freshwater polyp. Along with jellyfish, sea anemones, and corals, hydra are part of the animal family Cnidaria, who use stinging cells, or cnidocytes, to catch prey. Hydra tentacles contain barbed, poison-containing cnidocytes that they use to stun animals, such as water fleas and plankton, before eating them alive. They also use their cnidocytes for self-defense and locomotion. The research conducted at UCSB revealed that light, or the lack thereof, has a direct effect on hydras' propensity to fire their stinging cells –– a discovery Oakley said "tells us something completely new about the biology of these animals, and we think this could extend to other cnidarians." "Hydra stinging cells were already known to be touch sensitive and taste sensitive, but no one had ever thought before to look for light sensitivity –– probably because they don't have eyes," Oakley said. "We're the first to have found that. And we found not only that light-sensitivity genes are expressed near hydra stinging cells, but that under different light conditions, these cells have different propensities to be fired." Studying the hydra in both bright and dim conditions, the researchers discovered that bright light actually inhibits the firing of the stinging cells –– possibly because their prey are more active at dusk and after sunset, said Oakley. He suggested that light could be acting as "a daily, rhythmic cue" that tells hydra when, and when not, to sting. The research found that the light-sensitive protein opsin in sensory cells regulates the firing of the hydra's harpoon-like cnidocytes. These same cells are found in the mechanisms hydra use to grasp prey, and to summersault through the water. The linking of opsin to the stinging cells helps explain how hydra can respond to light despite the absence of eyes, the scientists said, because the sensory neurons also contain the ion channels and additional proteins required for phototransduction –– the process by which light is converted to electric signals. Phototransduction in humans occurs in the retina. "I wouldn't call this vision, because as far as we know the hydra are not processing information beyond what's light and what's dark, and vision is much more complicated than that. But these genes that we're studying are the keystones of vision," Oakley said. "For us, as evolutionists, the message is that photoreception can do other things besides just facilitate vision. It can do unexpected things. What good is half an eye? Even without eyes there are other functions for light sensitivity that we may not be thinking of." Oakley collaborated on the paper with David Plachetzki, a UCSB graduate student when the study was conducted, but now a postdoctoral fellow at UC Davis, and former UCSB undergrad Caitlin Fong. † Bottom image: Hydra, left, have the same visual pathway as humans. Their tentacles, right, contain stinging cells (shown here in red) that aid in movement, defense, and predation. Credit: David Plachetzki
Children and HIV and AIDS How does the epidemic affect children and young people? \|© UNICEF/ HQ05-2094/Cranston\| \|A boy raises his arms in victory during a football match on an airstrip in Southern Sudan. He is wearing a T-shirt that bears the logo and the slogan “Fight for life. Fight HIV/AIDS”.\| The face of HIV and AIDS is increasingly young. For every person living with AIDS, a family and a community is affected. As the disease kills parents and caregivers, it fuels poverty and despair among children and adolescents and stretches family resources. The impact of HIV and AIDS on children is seen most dramatically in the rising numbers of children and adolescents orphaned by AIDS. Such children face grave risks to their education, health, and well-being: They may have to forgo schooling; there may be less food or clothing for them in the household; they may suffer from anxiety, depression and abuse. But children orphaned by AIDS are not the only children affected by the epidemic. Many more children live with parents who are chronically ill, live in households that have taken in orphans or have lost teachers and other adult members of the community to AIDS. Almost as lethal as the virus itself is the stigma and resulting discrimination faced by people living with, or affected by, HIV. Because of the ignorance and denial that cloak the disease in many parts of the world, children whose parents have died from AIDS are often singled out for abuse in places they come to for support and care – harshly treated in foster homes, denied access to schooling and health care, stripped of their inheritances, and left to the streets. Stigma and discrimination remain the most potent barrier to testing, treatment and prevention. This explains in part why, in some countries, up to 90 per cent of people who are HIV-positive don’t know their status. Facts and Figures As of December 2007, children under 15 accounted for 290,000 deaths worldwide and 420,000 children were newly infected with HIV – the vast majority through mother-to-child transmission of the virus.
Debris flows occur naturally on most sloped surfaces. This type of 'mass wasting' is actually very common on the Moon. In this case why are small piles of debris accumulating in clumps? This clumping is quite different from other debris flows which are sometimes misidentified as impact melt flows. Perhaps the debris doesn't have enough energy to make it all the way down, or maybe the surface is not smooth. Or perhaps the crater wall is not a smooth surface perhaps there are little bumps and depressions. We can see a hint of such undulations from looking at the 'texture' of the surface of the crater wall (and others). We can also see this uneven wall surface in Digital Terrain Models of young craters. The bumpy surface acts to trap debris in shallow depressions, inhibiting growth of the spectacular debris flows seen elsewhere. Mass wasting is a continuous process and in a few tens of millions of years perhaps the interior of Benedict crater will look more like some other craters we have featured. Look for more debris along the crater wall of Benedict in the full LROC NAC! Related Posts: Dichotomy Back to Images
Temperature Measurement Devices for HVAC-R Temperature Measurement Overview Heat is a form of energy that flows between two samples of matter due to their difference in temperature. Temperature is a measurement of heat energy and is defined as the warmth or coldness of a substance with reference to some standard value. There have been many methods developed and used to measure temperature from simple thermometers to sophisticated, highly accurate, electronic transmitters. Siemens SITRANS T products provide highly accurate, temperature measurement transmitters and sensors for any commercial and industrial application. Types of Temperature Measurement Electronic temperature transmitters used for commercial and industrial temperature applications typically employ the use of either thermocouple or resistance temperature sensors. Both types have both pro’s and con’s associated with them, and selection is dependent on the application specifics. Thermocouples – A temperature sensing element consisting of two joined dissimilar metals which when heated produce a small voltage proportional to temperature. When the junction of the two metals is heated or cooled the voltage produced varies and can be correlated back to the temperature. Resistance (RTD) – A temperature sensing element consisting of a wire with a known resistance which when the measured temperature changes so too does the resistance in the wire. A small current sent through the element will vary depending on the resistance/temperature effect and can be correlated back to the temperature. Long term stability 06/14/2012 \| Author: Ryan.Shea@siemens.com
No, this is not about the furry companions many of us have or the wildly popular Broadway musical. The CATs I am talking about here are Classroom Assessment Techniques. All of us teach our students how important formative assessment is in developing curriculum for young children. Hopefully most of us use some sort of formative assessment in the college courses we teach. If not, we should. Nothing is more frustrating than to teach a topic, give an exam, and have the students do poorly on it. Was it the way we taught? Was it that the students could not follow what we were teaching? Were some concepts just harder than we thought? Formative assessment will tell us what the students know BEFORE that big exam and allow us to see if our instructional style is working and/or if we need to cover a topic again to cement the learning. Classroom Assessment Techniques: A Handbook for College Teachers by Thomas Angelo and Patricia Cross is a great book with a wide variety of formative assessment options. Many of your institutions may have the book in the library or access to it via interlibrary loan. It is not particularly expensive (under $40 on Amazon) but if you want to check it out before buying it, that would be the way to go. The book provides ideas for 50 different CATs. For each there is a description, purpose, level of required time/energy for both faculty and students, suggestions for use, examples, pros, cons, and caveats. Some of my favorite ideas from the book are: One Sentence Summary - Select an important topic that your students have recently studied and that you want them to be able to summarize - Working as quickly as they can, have your students answer Who Did/Does What to Whom, When, Where, How and Why? in relation to that topic. - Have the students then turn their answers into a grammatically correct (if long) sentence that follows the WDWWWWHW pattern. Example: Vygotsky’s theory of zone of proximal development - Identify an important and clearly applicable principle, theory, generalization, or procedure that your students are studying - Decide how many applications you will require. One is enough but no more than three - Pass out small index cards or slips of paper. Remind students to come up with fresh applications, not ones they have heard or read about. Example: Taking into account the effects of poverty, tell the implications for your teaching practice when working with this population. RSQC2 Otherwise known as Recall, Summarize, Question, Connect, and Comment - Recall: At beginning of class ask students to make a list in words or simple phrase of what they recall as the most important, useful, or meaningful points from the previous class - Summarize: Direct them to summarize as many of the most important points as they can into one summary sentence that captures the essence of the previous class - Question: Ask them to jot down one or two questions that remained unanswered after the previous class - Connect: Ask students to explain in 1-2 sentences the connection(s) between the main point(s) of the previous class and the goal(s) of the course - Comment: Invite the students to write an evaluative comment or two about the class (I enjoyed most/leas….I found _______most/least useful….During most of the class I felt….) All the above CATs are listed as low to medium time/effort for both faculty and students so they are good ones with which to start. There are other great formative assessment ideas out there. Do you use any of them? If so, share your ideas here in the comment section. We can all learn from each other.
Since 2002 it has been possible to remotely guide rats under human control. John Chapin and Sanjiv Tawlar achieved this at the State University of New York. The rat is fitted with a tiny backpack which contains a radio receiver. There are wires from the receiver into a part of the rat’s brain called the sensorimotor cortex. The receiver can detect three signals. One signal is used to command the rat to turn left. This sends an impulse to the wire that makes the rat feel as if its left whiskers have been twitched. Another signal is used to command the rat to turn right. This makes the rat feel as if its right whiskers have been twitched. The third signal goes to the pleasure center in the rat’s brain, and is used to reward the rat for turning in the way that its masters want it to. In this way, the rat can be rewarded for turning towards the direction that it thinks it has had its whiskers twitched, and it soon learns to comply. You can see the remotely-guided rat at this YouTube video. Obviously this raises enormous ethical considerations, and many people will find the experiment and its implications disturbing. The researchers claim that the rat does have a choice (if it is prepared to forego its reward), and say that they hope to use the experiment to reveal information about the functioning of the brain. Dr Talwar, one of the researchers involved, acknowledges that there might be ethical objections, saying that “the idea is sort of creepy. I do not have the answer to that.” The possible military applications are quite frightening to contemplate, but there are also potential humanitarian applications such as searching for survivors amongst the rubble after an earthquake. It’s not only rats that humans have remote-controlled. Chinese researchers claim to have forced pigeons to fly by remote control using electrodes implanted in their brains (the pigeon’s brain, not the researcher’s brain). And Cornell University researchers can make moths fly, while University of Michigan researchers can make beetles fly. A similar thing can also be done the other way around. Cells from a rat’s brain can be transplanted into a robot. Need research? Quezi's researchers can answer your questions at uclue.com
Research on Ancient Roman Concrete Will Allow the Creation of More Durable and Environmentally Friendly Concrete Posted on June 23, 2013 Comments (2) Analysis of samples of ancient Roman concrete pinpointed why the best Roman concrete was superior to most modern concrete in durability, why its manufacture was less environmentally damaging – and how these improvements could be adopted in the modern world. “It’s not that modern concrete isn’t good – it’s so good we use 19 billion tons of it a year,” says Paulo Monteiro (U.S. Department of Energy’s Lawrence Berkeley National Laboratory). “The problem is that manufacturing Portland cement accounts for seven percent of the carbon dioxide that industry puts into the air.” Portland cement is the source of the “glue” that holds most modern concrete together. But making it releases carbon from burning fuel, needed to heat a mix of limestone and clays to 1,450 degrees Celsius (2,642 degrees Fahrenheit) – and from the heated limestone (calcium carbonate) itself. Monteiro’s team found that the Romans, by contrast, used much less lime and made it from limestone baked at 900˚ C, or lower, requiring far less fuel than Portland cement. Cutting greenhouse gas emissions is one powerful incentive for finding a better way to provide the concrete the world needs; another is the need for stronger, longer-lasting buildings, bridges, and other structures. Roman harbor installations have survived 2,000 years of chemical attack and wave action underwater. We now expect our construction to last 50 to 100 years. The Romans made concrete by mixing lime and volcanic rock. For underwater structures, lime and volcanic ash were mixed to form mortar, and this mortar and volcanic tuff were packed into wooden forms. The seawater instantly triggered a hot chemical reaction. The lime was hydrated – incorporating water molecules into its structure – and reacted with the ash to cement the whole mixture together. Pozzuoli Bay defines the northwestern region of the Bay of Naples. The concrete sample examined at the Advanced Light Source by Berkeley researchers, BAI.06.03, is from the harbor of Baiae, one of many ancient underwater sites in the region. Black lines indicate caldera rims, and red areas are volcanic craters. In concrete made with Portland cement this is a compound of calcium, silicates, and hydrates (C-S-H). Roman concrete produces a significantly different compound, with added aluminum and less silicon. The resulting calcium-aluminum-silicate-hydrate (C-A-S-H) is an exceptionally stable binder. X-ray spectroscopy showed that the specific way the aluminum substitutes for silicon in the C-A-S-H may be the key to the cohesion and stability of the seawater concrete. Another striking contribution of the Monteiro team concerns the hydration products in concrete. In theory, C-S-H in concrete made with Portland cement resembles a combination of naturally occurring layered minerals, called tobermorite and jennite. Unfortunately these ideal crystalline structures are nowhere to be found in conventional modern concrete. Finally, microscopic studies at identified the other minerals in the Roman samples. Integration of the results from the various beamlines revealed the minerals’ potential applications for high-performance concretes, including the encapsulation of hazardous wastes. Lessons for the future Environmentally friendly modern concretes already include volcanic ash or fly ash from coal-burning power plants as partial substitutes for Portland cement, with good results. These blended cements also produce C-A-S-H, but their long-term performance could not be determined until the Monteiro team analyzed Roman concrete. Their analyses showed that the Roman recipe needed less than 10 percent lime by weight, made at two-thirds or less the temperature required by Portland cement. Lime reacting with aluminum-rich pozzolan ash and seawater formed highly stable C‑A-S-H and Al-tobermorite, insuring strength and longevity. Both the materials and the way the Romans used them hold lessons for the future. “For us, pozzolan is important for its practical applications,” says Monteiro. “It could replace 40 percent of the world’s demand for Portland cement. And there are sources of pozzolan all over the world. Saudi Arabia doesn’t have any fly ash, but it has mountains of pozzolan.” Stronger, longer-lasting modern concrete, made with less fuel and less release of carbon into the atmosphere, may be the legacy of a deeper understanding of how the Romans made their incomparable concrete.
A team of paleontologists discovered over 500 million years old fossils which revealed themselves to be the first creatures capable of moving around on their own. This makes them an important piece in the theory of the human and animal evolution timeline. The 500 Million Years Old Fossils are the Remains of Almost Microscopic Creatures The University of Manchester group of researchers behind the discovery revealed that they found these fossils in Brazil. Dating the fossilized remains showed them to go back to the period known as the Ediacaran-Cambrian transition. During this meeting point period, science considers that there was an ‘explosion’ of life on Earth as a great variety of creatures emerged at once. The oldest examples of bilaterian animals also go back to this same transition point. Bilaterians are animals which have a body that can be divided into a top and a bottom. Also, in a left and a right side, a front and back one. These recently discovered over 500 million years old fossils were noted to trace back to even earlier than any of the currently known bilaterians. The creatures were discovered thanks to the burrowed traces they left in the rocks. According to reports, these were just ‘a fraction of an inch in diameter’ or somewhere between 0.002 and 0.0024 inches. Based on this, the university team determined that the creatures to leave these tracks “were similar in size to a human hair”. They consider that these organisms left behind the burrows as they dug through the sediment layers. The creatures were likely comparable to the present-day roundworms, believes the team. Such organisms would have propelled themselves through undulating locomotion or the wave-like movement of their body. This also places them in the complex animals class, as they were able to move themselves. “Our new fossils show that complex animals with muscle control were around approximately 550 million years ago, and they may have been overlooked previously because they are so tiny,” states Luke Parry, the study lead author, part of the University of Bristol. The team studied the fossils by creating a 3D model of the rocks containing them through X-ray images. This way, they were able to take a closer look at the creatures without damaging them. Study findings are available in the journal Nature Ecology & Evolution. Image Source: Wikimedia Latest posts by Karen Jackson (see all) - Mark Hamill Admits to Being Skeptical About Returning in the New Star Wars Movies - November 1, 2017 - Google Earth Helps Researchers Spot Ancient Stone Gates in Saudi Arabia - October 27, 2017 - The Death of Stalin Might Cause Nationalist Uproars in Russia - October 16, 2017
The Huzita–Hatori axioms or Huzita–Justin axioms are a set of rules related to the mathematical principles of paper folding, describing the operations that can be made when folding a piece of paper. The axioms assume that the operations are completed on a plane (i.e. a perfect piece of paper), and that all folds are linear. These are not a minimal set of axioms but rather the complete set of possible single folds. The axioms were first discovered by Jacques Justin in 1986. Axioms 1 through 6 were rediscovered by Japanese-Italian mathematician Humiaki Huzita and reported at the First International Conference on Origami in Education and Therapy in 1991. Axioms 1 though 5 were rediscovered by Auckly and Cleveland in 1995. Axiom 7 was rediscovered by Koshiro Hatori in 2001; Robert J. Lang also found axiom 7. The seven axioms The first 6 axioms are known as Huzita's axioms. Axiom 7 was discovered by Koshiro Hatori. Jacques Justin and Robert J. Lang also found axiom 7. The axioms are as follows: - Given two distinct points p1 and p2, there is a unique fold that passes through both of them. - Given two distinct points p1 and p2, there is a unique fold that places p1 onto p2. - Given two lines l1 and l2, there is a fold that places l1 onto l2. - Given a point p1 and a line l1, there is a unique fold perpendicular to l1 that passes through point p1. - Given two points p1 and p2 and a line l1, there is a fold that places p1 onto l1 and passes through p2. - Given two points p1 and p2 and two lines l1 and l2, there is a fold that places p1 onto l1 and p2 onto l2. - Given one point p and two lines l1 and l2, there is a fold that places p onto l1 and is perpendicular to l2. Axiom 5 may have 0, 1, or 2 solutions, while Axiom 6 may have 0, 1, 2, or 3 solutions. In this way, the resulting geometries of origami are stronger than the geometries of compass and straightedge, where the maximum number of solutions an axiom has is 2. Thus compass and straightedge geometry solves second-degree equations, while origami geometry, or origametry, can solve third-degree equations, and solve problems such as angle trisection and doubling of the cube. The construction of the fold guaranteed by Axiom 6 requires "sliding" the paper, or neusis, which is not allowed in classical compass and straightedge constructions. Use of neusis together with a compass and straightedge does allow trisection of an arbitrary angle. Given two points p1 and p2, there is a unique fold that passes through both of them. In parametric form, the equation for the line that passes through the two points is : Given two points p1 and p2, there is a unique fold that places p1 onto p2. This is equivalent to finding the perpendicular bisector of the line segment p1p2. This can be done in four steps: - Use Axiom 1 to find the line through p1 and p2, given by - Find the midpoint of pmid of P(s) - Find the vector vperp perpendicular to P(s) - The parametric equation of the fold is then: Given two lines l1 and l2, there is a fold that places l1 onto l2. This is equivalent to finding a bisector of the angle between l1 and l2. Let p1 and p2 be any two points on l1, and let q1 and q2 be any two points on l2. Also, let u and v be the unit direction vectors of l1 and l2, respectively; that is: If the two lines are not parallel, their point of intersection is: The direction of one of the bisectors is then: And the parametric equation of the fold is: A second bisector also exists, perpendicular to the first and passing through pint. Folding along this second bisector will also achieve the desired result of placing l1 onto l2. It may not be possible to perform one or the other of these folds, depending on the location of the intersection point. If the two lines are parallel, they have no point of intersection. The fold must be the line midway between l1 and l2 and parallel to them. Given a point p1 and a line l1, there is a unique fold perpendicular to l1 that passes through point p1. This is equivalent to finding a perpendicular to l1 that passes through p1. If we find some vector v that is perpendicular to the line l1, then the parametric equation of the fold is: Given two points p1 and p2 and a line l1, there is a fold that places p1 onto l1 and passes through p2. This axiom is equivalent to finding the intersection of a line with a circle, so it may have 0, 1, or 2 solutions. The line is defined by l1, and the circle has its center at p2, and a radius equal to the distance from p2 to p1. If the line does not intersect the circle, there are no solutions. If the line is tangent to the circle, there is one solution, and if the line intersects the circle in two places, there are two solutions. If we know two points on the line, (x1, y1) and (x2, y2), then the line can be expressed parametrically as: Let the circle be defined by its center at p2=(xc, yc), with radius . Then the circle can be expressed as: In order to determine the points of intersection of the line with the circle, we substitute the x and y components of the equations for the line into the equation for the circle, giving: Then we simply solve the quadratic equation: If the discriminant b2 − 4ac < 0, there are no solutions. The circle does not intersect or touch the line. If the discriminant is equal to 0, then there is a single solution, where the line is tangent to the circle. And if the discriminant is greater than 0, there are two solutions, representing the two points of intersection. Let us call the solutions d1 and d2, if they exist. We have 0, 1, or 2 line segments: A fold F1(s) perpendicular to m1 through its midpoint will place p1 on the line at location d1. Similarly, a fold F2(s) perpendicular to m2 through its midpoint will place p1 on the line at location d2. The application of Axiom 2 easily accomplishes this. The parametric equations of the folds are thus: Given two points p1 and p2 and two lines l1 and l2, there is a fold that places p1 onto l1 and p2 onto l2. This axiom is equivalent to finding a line simultaneously tangent to two parabolas, and can be considered equivalent to solving a third-degree equation as there are in general three solutions. The two parabolas have foci at p1 and p2, respectively, with directrices defined by l1 and l2, respectively. Given one point p and two lines l1 and l2, there is a fold that places p onto l1 and is perpendicular to l2. This axiom was originally discovered by Jacques Justin in 1989 but was overlooked and was rediscovered by Koshiro Hatori in 2002. Robert J. Lang has proven that this list of axioms completes the axioms of origami. Subsets of the axioms can be used to construct different sets of numbers. The first three can be used with three given points not on a line to do what Alperin calls Thalian constructions. The first four axioms with two given points define a system weaker than compass and straightedge constructions: every shape that can be folded with those axioms can be constructed with compass and straightedge, but some things can be constructed by compass and straightedge that cannot be folded with those axioms. The numbers that can be constructed are called the origami or pythagorean numbers, if the distance between the two given points is 1 then the constructible points are all of the form where and are Pythagorean numbers. The Pythagorean numbers are given by the smallest field containing the rational numbers and whenever is such a number. Adding the neusis axiom 6, all compass-straightedge constructions, and more, can be made. In particular, the constructible regular polygons with these axioms are those with sides, where is a product of distinct Pierpont primes. Compass-straightedge constructions allow only those with sides, where is a product of distinct Fermat primes. (Fermat primes are a subset of Pierpont primes.) The seventh axiom does not allow construction of further axioms. The seven axioms give all the single-fold constructions that can be done rather than being a minimal set of axioms. An eighth axiom The existence of an eighth axiom was claimed by Lucero in 2017, which may be stated as: there is a fold along a given line l1. The new axiom was found after enumerating all possible incidences between constructible points and lines on a plane. Although it does not create a new line, it is nevertheless needed in actual paper folding when it is required to fold a layer of paper along a line marked on the layer immediately below. - Justin, Jacques (1986). "Résolution par le pliage de l'équation du troisième degré et applications géométriques" (PDF). L’Ouvert - Journal de l’APMEP d’Alsace et de l’IREM de Strasbourg (in French). 42: 9–19. Retrieved September 7, 2016. - Thomas C. Hull (April 2011). "Solving Cubics With Creases: The Work of Beloch and Lill" (PDF). American Mathematical Monthly: 307–315. doi:10.4169/amer.math.monthly.118.04.307. - Roger C. Alperin; Robert J. Lang (2009). "One-, Two-, and Multi-Fold Origami Axioms" (PDF). 4OSME. A K Peters. - Alperin, Roger C (2000). "A Mathematical Theory of Origami Constructions and Numbers" (PDF). New York Journal of Mathematics. 6: 119–133. - D. Auckly and J. Cleveland. "Totally real origami and impossible paperfolding". American Mathematical Monthly. 102: 215–226. arXiv: . doi:10.2307/2975008. - Lucero, Jorge C. (2017). "On the Elementary Single-Fold Operations of Origami: Reflections and Incidence Constraints on the Plane" (PDF). Forum Geometricorum. 17: 207–221. - Lee, Hwa Y. (2017). Origami-Constructible Numbers (PDF) (Master's Thesis). University of Georgia. p. 64. - Origami Geometric Constructions by Thomas Hull - A Mathematical Theory of Origami Constructions and Numbers by Roger C. Alperin - Lang, Robert J. (2003). "Origami and Geometric Constructions" (PDF). Robert J. Lang. Retrieved 2007-04-12.
Dr. Ray Huntington of the Huntington Learning Center urges parents to engage their children in learning activities to avoid summer regression. Put simply, summer regression is the loss of academic knowledge gained throughout the school year. “Learning loss or the ‘summer slide’ among students over summer break is a very real problem that we see often,” says Huntington, adding that most students can lose several months of grade-level equivalency in math and reading achievement during this period. He offers several ways for parents to help minimize summer regression. The end of the school year may find your children exhausted from a year of hard work and fixated on that great burst of freedom that begins in June. If so, your suggestion that they consider some "summertime learning activities" might not go over too well. But staying smart during the warm weather months doesn't depend on test-taking and fretting over grades. With less structure and more adventure, the following activities can turn leisure time into learning time and help prepare your child for challenges in the year to come.
Microwave ovens have been using the same basic cooking technology for decades. Now, with the availability of solid state cooking techniques promises to significantly change how we cook our food. Today’s ovens are powered by a magnetron, a device originally developed for World War II radar systems. Magnetrons use an old-fashioned vacuum tube (valves) approach to generate the necessary short-wavelength radio waves for cooking. But what are the challenges with this approach? Why should we change? The first observation is that magnetrons don’t actually cook food very well. They don’t always heat evenly, so food can be overcooked in some places and raw in others, and they deliver less power when they’re warm, which means the same dish can require more time to cook if the oven has already been in heavy use. Magnetrons also have a relatively short lifespan – typically about 500 hours in the average household oven, and about a year of continuous use in commercial environments – and they get weaker as they age, so food takes longer to cook before the oven stops working entirely. The good news, though, is that magnetrons can finally be retired. Recent developments in wireless communication have yielded radio frequency (RF) components – including the high-power transistors needed for microwave generation – that deliver higher efficiency, greater power density, and improved voltage capability, at prices that are competitive enough for consumer appliances like microwave ovens. Replacing magnetrons with solid-state electronics promises to transform microwave cooking, with appliances that cook more evenly, more consistently, more efficiently, and with more predictable results. The overall cooking experience will be greatly enhanced with this approach. As I’m sure we’ve all experienced from time to time, microwaves do produce hot and cold spots in the food. Using solid-state RF for precise phase control makes it possible to redirect hot spots, for more uniform heating and greater efficiency. Multi-source phase locking, a concept used in mobile phones to improve signal delivery, adds another level of control and efficiency. Controlling frequency and power output depending on the food being cooked will also improve this aspect of microwave cooking. The use of solid-state components results in a more accurate and stable cooking cycle. Power control is more linear with this approach so there is less temperature variation within a cooking cycle. Also, the latest modulation and digital signal-processing (DSP) techniques make the microwave signal more accurate and more stable. Being able to support frequency tuning ensures that the oven can make full use of the frequency spectrum in order to increase cooking efficiency and thereby improve overall power efficiency. In this way it makes it easier to modify the oven’s operation based on what’s being cooked, since a bag of popcorn is very different from a raw potato or a frozen turkey. Another major benefit is that by using modern sensor technology it is possible to constantly monitor, adapt and optimize the cooking process in real-time. By means of sensors and closed-loop algorithms the oven incorporates a far more sophisticated measurement system that can take account of reflected power and the absorption characteristics of the food being cooked. This is of course a long way from the extremely simple on/off cycle that most microwaves employ today. The final observation is that of reliability. Already used in high reliability rugged applications such as cellular base stations, solid-state RF components are designed to operate without interruption for a long as fifteen years. Manufacturers will greatly value the positive influence that having a reliable microwave oven will add to their brand. For consumers a more reliable, effective and power efficient cooking device will open up the microwave oven to becoming a more trusted and flexible kitchen appliance that can be used for a lot more than just warming up last night’s takeaway!
Lab Exercise 11: 3D Turtle The purpose of this lab is to give you one more chance to extend your drawing system. You should have a reasonable understanding of how all the pieces fit together, so now we're going to swap out the standard 2D turtle and put in a 3D turtle. All of your 2D turtle programs should continue to work just fine, but now you can make 3D shapes as well. In addition, you'll be able to rotate your completed drawings with the mouse. The lab consists of three parts. - First, you need to edit your TurtleInterpreter class to make use of the 3D turtle. Once this is complete, you can try drawing some simple shapes. - Second, you need to implement the 3D symbols for L-systems so you can draw 3D trees. - Third, you need to update your Shape class and possibly some of its children to make use of the 3rd dimension. The goal is to be able to make 3D shapes and scenes as easily as 2D. You should be able to create a Cube class, for example, as well as 3D trees and other L-system shapes that work exactly the same way as their 2D counterparts. - Create a new working folder. Copy your lsystem.py, turtle_interpreter.py, shapes.py, and tree.py files from last week. Label them as version 5. Then download the 3D turtle file (which is documented at the bottom of this page). One difference between the standard turtle and the 3D turtle is that the latter is implemented as a class. Therefore, you need to create a single instance of the turtle object that will be used by all At the top of turtle_interpreter.py, import turtleTk3D instead of turtle, and create a global variable called turtle and initialize it to None. Second, before calling any other turtle functions in your __init__ method, but after the test of TurtleInterpreter.initialized, put the following two lines. global turtle turtle = turtleTk3D.Turtle3D(dx, dy) The first line tells the function to use the turtle variable in the global symbol table, and the second line creates a new turtleTk3D object. By putting the 3D turtle object in a variable called turtle, expressions like turtle.left(angle) or turtle.forward(distance) still work as expected. Make the following additional changes to turtle_interpreter.py. - Edit your hold method so that it calls only turtle.mainloop(). - If you have not already done so, make your '[' and ']' cases store and restore the turtle width in addition to the heading and position. Edit your orient method so it takes two additional optional arguments: roll and pitch. The definition should look like: def orient(self, angle, roll=0, pitch=0) The function should first call the turtle method setheading with an argument of 0, then roll by the roll argument (e.g. turtle.roll(roll)), pitch by the pitch argument, and yaw by the angle argument. - If you have a goto method, add an optional parameter zpos with a default value of 0. Then change the turtle.goto call to include zpos as the third argument. Do the same with the place method. It should have two required arguments (xpos and ypos) and four optional arguments (angle, roll, pitch, and zpos). Note that if you set up the arguments as place(xpos, ypos, zpos=0, angle=None, pitch=0, roll=0) it will break your prior code that assumes angle is the third argument. It's probably better to make zpos the last argument. Give the new arguments (zpos, pitch, and roll) default values of 0. The other change to the place method is in the case where angle is not None, call your turtle interpreter's orient function (self.orient) with angle, roll, and pitch as the arguments. - Create additional turtle interpreter methods called roll, pitch, and yaw, that call the 3D turtle functions roll, pitch and yaw. These functions will look like your existing width or color functions. - The turtle.position() method now returns the tuple (x, y, z) instead of just (x, y). There are likely some places in your TurtleInterpreter's forward method that need to be updated to handle the z coordinate. In the jitter and jitter3 cases, you probably want to add a random offset in z, in addition to x and y, and make all of your goto calls include the z coordinate. Add cases in your drawString method for pitch ( & and ^ ) and roll (\ and /). The & symbol means to execute the pitch method with a positive angle (down), and ^ should execute the pitch method with a negative angle (up). The backslash '\' should execute the roll with a positive angle (right), and the forward slash '/' should execute roll with a negative angle Yaw is still + and -. Note that you will have to use the string '\\' to represent the backward slash character because it is a special character (e.g., '\n' is a newline and '\t' is a tab) . - The 3D turtle color function works slightly differently from the regular turtle. The primary difference is that it takes as input r, g, b values, a color string, or a single tuple (r, g, b) and it returns only a single color value. You'll need to edit your angle bracket cases '<' and '>' to take into account that there is no pencolor/fillcolor separation. - You may need to update your code in the turtle interpreter to use functions offered by the 3D turtle. For example, the 3D turtle has position and goto methods, but not pos or setposition. - When you are done with these changes, try out first test program. Make the following changes to shapes.py. - Add three optional parameters to the Shape class draw function. The arguments should be called roll, pitch, and zpos. Given them all default values of 0. The orientation parameter already holds the yaw information. - Add zpos, pitch and roll to the place call before drawString. - Run test function two. It is a simple example of how to begin building a 3D scene. - Update your tree.py file. Add roll, pitch, and zpos to the parameter list of the Tree class draw method, giving them all default values of 0. Then pass the three parameters on to the parent draw function. Then run the test function 3 using one of the L-systems below. When you are done with the lab exercises, you may begin the project. Appendix: Turtle3D Documentation The Turtle3D class implements a 3D turtle abstraction using the Tkinter package. The default turtle window supports three user operations. - Once drawing is complete, the user can rotate the image using the first mouse button and clicking and dragging. - The user can close the window and quit the program by typing Command-q or by typing just q. - The user can reset the view to the default orientation by typing Command-r or by typing just r. The Turtle3D class includes the following methods for public use. __init__: the constructor function has six optional arguments. - winx (default 800) is the horizontal window size - winy (default 800) is the vertical window size - title (default 'Turtle 3D') - position (default (0, 0, 0) ) is the initial 3D position of the turtle - heading (default (1.0, 0.0, 0.0)) is the initial forward direction of the turtle - up (default (0.0, 0.0, 1.0)) is the initial up direction, which defines left and right (yaw) relative to the forward direction. The default values mean that left and right work identically to the standard 2D turtle as long as the turtle does not pitch or roll. - reset(): deletes all drawing and resets the turtle to its initial position. - forward(distance): goes forward in the current turtle direction. If the pen is down, it creates a line. goto(xnew, ynew, znew): The function can take one, two or three parameters. If the pen is down, it creates a line. - One parameter: xnew is treated as a two-element tuple (x, y) and the turtle is placed at (x, y, 0). - Two parameters: xnew and ynew are used and znew is set to 0. - Three parameters: the turtle is placed at (xnew, ynew, znew). - left(angle): turn left (yaw) as defined by the current heading and up direction. - right(angle): turn right (yaw) as defined by the current heading and up direction. - yaw(angle): go left (positive) or right (negative) relative to the current turtle orientation. - pitch(angle): go up (positive) or down (negative) relative to the current turtle orientation. - roll(angle): rotate right (positive) or left (negative) about the current turtle heading. - width(w): set the width of the pen to w - color(r, g, b): sets the pen color. Arguments can be the standard X11 color strings defined in rgb.txt or r, g, b values. The first argument can be a tuple (r, g, b) or the color values can be given individually. Color values should be in [0, 1]. - up(): pick up the pen - down(): put down the pen - tracer(blah): does nothing (no visible turtle) - circle(radius, theta): draws a circle of the given radius. The theta argument is optional and permits drawing only the angular fraction of the circle specified. - position(): returns a tuple with (x, y, z) - heading(): returns a tuple of two tuples with the current heading and up vectors. ( (hx, hy, hz), (ux, uy, uz) ) - setheading(heading): ideally heading should be two vectors representing the turtle's forward and up directions. If a single scalar is provided, the turtle is set so the turtle is in the drawing plane (up of (0, 0, 1)) and is rotated according to the argument. This gives it the same functionality as the 2D turtle. - fill(q): if q is True, the turtle will begin to store points until the fill function is called with False as the argument. Then it fills in the area defined by the points. The turtle must visit at least three points after fill(True) is called and before fill(False) is called in order to generate a polygon. - nudge(n): allows the user to adjust the turtle's coordinate system by nudging the forward vector in the specified direction. The argument n should be a 3-element sequence (list or tuple). A value like (0.0, -0.1, 0.0) nudges the turtle's orientation down (i.e. like gravity). - cube(distance): takes one optional parameter (size) and draws a cube. - setRightMouseCallback(func): takes one argument, which should be a function with an argument (other than self for a class method) called event. The mouse click location will be in event.x and event.y. Note that the click location will be in window coordinates, not turtle coordinates. - window2turtle(x, y): takes in window coordinates (like those in event.x and event.y above) and returns a tuple (x', y', 0) with the corresponding turtle coordinates in the default view. - hold(): goes into a main loop waiting for user input. - wait(): goes into a main loop waiting for user input. - updateCanvas(): updates the Canvas to draw any new shapes.
The findings also help confirm one of the basic assumptions of functional MRI. The technology measures changes in blood flow to brain cells, which neuroscientists use as a proxy for neural activity. Finding a population of cells that respond specifically to faces within the face-processing region highlighted by MRI “shows that the assumption everyone operates under is correct,” says Christof Koch, a neuroscientist at the California Institute of Technology, in Pasadena. Tsao is now studying the different properties of each face-processing region in more detail. One face patch, for example, appears to be involved in detecting the overall shape of the face. “Our hypothesis is that it measures ratios [between facial features], but that it hasn’t made the identity of the face explicit yet,” she says. “I think the three anterior regions are encoding other aspects of faces–expression, movement, memory, identity.” To truly understand how the brain processes visual information, scientists must figure out how disparate pieces of information–the shape of the face and a sense of recognition of the face, for example–are bound together to create our perception of the face. Using dyes detectable with MRI to trace connections between different neurons, Tsao will record activity from multiple connected cells to determine how visual information is summed and shaped as it travels through the brain. “I think that seeing how this information is transformed will clarify a lot of what the brain is doing,” she says. Ultimately, Tsao’s work could shed light on how neural activity leads to conscious visual perception. “It’s a step toward answering the age-old question, how does visual conscious perception arise from the underlying neural activity?” says Koch. “What is the relation between the mind and the brain?”
You probably know that August’s annual sky show, the Perseid meteor shower, is on display this week as Earth passes through a trail of debris left by Comet Swift-Tuttle. Meteors will be lighting up the night through August 24th, but the real crescendo will take place this Friday, August 12th, in the wee hours of the morning. The shower gets its name from the Perseus constellation, the cluster of stars that it appears to be radiating from. But you might not know that the Perseids are one of about 12 annual meteor showers that we can easily observe in our skies. One of the reasons they get extra attention is because they occur during the height of summer vacation, when they are primarily visible in the northern hemisphere. (The Geminids put on the most reliable show, but only the truly dedicated stargazer is willing to stand out cold in mid-December for hours on end to see them.) The other reason has to do with the fact that Swift-Tuttle was discovered way back in 1862. “This is one of the first comets that really convinced people that there was a direct link between certain comets and meteor showers,” says James Zimbelman, a planetary geologist at Smithsonian’s National Air and Space Museum. Each meteor shower is associated with a comet—or in rare cases, an asteroid—whose orbit brings it into the inner solar system, close enough for the sun to cause some of its ices to sublimate. Comets are like dirty snowballs, a loosely packed conglomeration of ice and dust left over from the formation of our solar system. They are believed to live en masse in a spherical reservoir called the Oort Cloud that exists at the outer limits of the sun’s gravitational influence. I say “believed” because we can’t observe such small objects directly at such great distances—comets are only .1 to 50 miles in diameter, or more than 40 times smaller than our moon. Instead, we infer the existence of the Oort Cloud based on the fact that the orbits of the comets we have observed to date suggest that they come from all directions, not just within the plane of the solar system. The vast majority of comets spend their entire lives in a deep freeze, never making themselves known to us. But every now and then, one of them is kicked out of the Oort Cloud and sent hurtling towards the sun. Even then, the comet usually remains frozen until it gets to 2-5 AU (astronomical units, aka Earth-sun distances), where the sun’s heat is finally strong enough to transform the surface ice directly into gas. Known as sublimation, this process destabilizes pockets of dust and rocks on the surface, which are then released and strewn throughout the comet’s path—giving comets the comas and dust tails we observe. The closer the comet gets to the sun, the more active its surface is and the larger the coma and tail can grow. Some comas can extend tens of thousands or even hundreds of thousands of miles in diameter, creating debris trails orders of magnitude larger than their nuclei. Similarly, dust tails can be a long as several AU. Not all comets display the same amount of activity during their sojourn through the inner solar system. It often depends on how many trips they’ve already made. Each orbit sublimates more and more ice, until there’s none left and the comet is nothing more than an inert assemblage of rocks and dust. The comet that gives rise to the Perseids is Comet Swift-Tuttle, which is approximately 16 miles in diameter. It orbits the sun once every 133 years and comes within 84,000 miles of Earth (closer than the moon). Swift-Tuttle’s most recent visit to our neighborhood was in 1992, and as a result, the 1993 Perseids had a peak rate of 500 meteors per hour. The year 1992 was also then the last time its orbit was replenished with debris—the more recently a comet has passed through the inner solar system, the more dust particles it leaves in its wake (more dust particles results in a higher peak meteor rate). So in theory, we won’t see a peak that high again until 2126. But here’s the thing about orbits: They can change. Every object in the solar system exerts a gravitational pull on every other object. The closer any two objects are and the larger the mass difference between them, the stronger this pull can be. While most comets are gravitationally bound to the sun, their orbits sometimes take them dangerously close to Jupiter, close enough for those orbits to change ever so slightly. Computer simulations have shown that this might have happened not to Swift-Tuttle itself, but to its debris trail, nudging it ever so slightly closer to Earth. It’s possible that this nudge could be enough to cause a peak rate close to 200 meteors per hour, a peak which is predicted to take place in the early, early morning of August 12th. So wherever you happen to be this week, get outside in the hopes of catching some of the show. Each meteor you see streaking across the sky this week is a fragment of the original material of our solar system, our planet and our selves were made from. Peak or no peak, meteors are a beautiful sight and reminder of the wonder of the universe.
“Cognitive” means of or relating to “cognition” — which refers to a range of high-level brain functions including the ability to learn and remember information, organize, plan and problem-solve, focus, maintain and shift attention, understand and use language, accurately perceive the environment, and perform calculations. Cognitive changes are a common symptom of MS — approximately half of all people with MS will develop problems with cognition. Loss of myelin around nerve fibers can cause difficulty with transporting memories to storage areas of the brain or retrieving them from storage areas. In MS, certain functions are more likely to be affected than others: - Memory (acquiring, retaining and retrieving new information) - Attention and concentration (particularly divided attention) - Information processing (dealing with information gathered by the five senses) - Executive functions (planning and prioritizing) - Visuospatial functions (visual perception and constructional abilities) - Verbal fluency (word-finding) A person may experience difficulties in only one or two areas of cognitive functioning or in several. Certain functions including general intellect, long-term (remote) memory, conversational skill and reading comprehension are likely to remain intact. Only 5-10 percent of people with MS develop problems severe enough to interfere significantly with everyday activities. In very rare instances, cognitive dysfunction may become so severe that the person can no longer be cared for at home. Relationship to other disease factors Cognitive problems are weakly related to other disease characteristics — meaning that a person with almost no physical limitations can have significant cognitive impairment, while a person who is quite disabled physically can be unaffected cognitively. - Changes can occur at any time — even as a first symptom of MS — but are more common later in the disease. - Cognitive function correlates with number of lesions and lesion area on MRI, as well as brain atrophy. - Cognitive dysfunction can occur with any disease course, but is slightly more likely in progressive MS. - You are more likely to experience cognitive dysfunction (the first signs or new changes) during an exacerbation. - Cognitive changes generally progress slowly. They are unlikely to improve dramatically once they have begun. Early recognition, assessment and treatment are important because cognitive changes — along with fatigue — can significantly affect a person’s quality of life and are the primary cause of early departure from the workforce. The first signs of cognitive dysfunction may be subtle — noticed first by the person with MS or by a family member or colleague. - Difficulty finding the right words - Trouble remembering what to do on the job or during daily routines at home - Difficulty making decisions or showing poor judgment - Difficulty keeping up with tasks or conversations Talk to your physician if you are concerned about cognitive dysfunction. A specially trained health professional (neuropsychologist, speech/ language pathologist or occupational therapist) will administer a battery of tests and careful evaluation in order to determine the cause(s) of changes (since cognitive function can also be affected by aging or medications, as well as depression , anxiety, stress Treatment (cognitive rehabilitation) Based on the test findings — including cognitive deficits and strengths — the health professional can provide cognitive rehabilitation. Cognitive rehabilitation includes a combination of restorative and compensatory activities. can include learning and memory exercises: - Combine modes of learning: You will be more likely to remember something if you “see it, say it, hear it, write it, do it.” It’s okay to give yourself extra time. - Repeat & verify: Repeat what you hear and verify that it is correct to improve your attention and memory. - Spaced rehearsal: Repeat and practice information at intervals spread out over time to improve your ability to store information. - Build associations: Use memory aids! For example, to remember the name of someone you just met, associate her/his name with a friend or family member of the same name, or with a place, color or event that sounds like the new name. — to make up for functions that are weakened — include: - Consolidate and centralize! Designate one place in your home as the “Grand Central” information center. Include your master calendar, mail, bills, phone messages, to-do lists, keys, wallet, shopping lists and more. - Plan: Post a calendar large enough to display everyone’s appointments, activities and social engagements, and reminders! Keep pens or markers hanging right beside it. Or use a computer program set up with reminders for routine tasks (synchronize it with your mobile devices so you have your appointments with you while on the go). - Record: Dictate your to-do list, notes or other things to remember on a digital voice recorder (available on many phones). - Remind: Use checklists, the alarm on your watch or phone, your kitchen timer, and more. - Eliminate or remove yourself from distractions. Turn off the TV, music and whatever else is “on” when speaking with someone in person or on the phone. Background visual and noise distractions can make learning or remembering more difficult. If you can’t eliminate the distraction (for example, people talking at a party) then ask, “Can we talk in a quieter place?” - Take a break. If you are having difficulty concentrating, take a breath and refresh. - Do one thing at a time. Avoid switching back and forth from one topic or task to another. Finish or find an appropriate stopping place in what you’re working on before you switch to something else. Studies are ongoing to identify ways to stabilize or improve cognitive dysfunction. Since the disease-modifying drugs have all been shown to reduce the accumulation of new demyelinating lesions, it is likely they help to stabilize cognitive changes. However, more studies are needed to determine their effectiveness in this area. Symptomatic treatments may temporarily improve cognitive functioning without altering its long-term course. To date the most successful has been donepezil hydrochloride, showing modest improvement in verbal memory. Studies funded by the National MS Society are investigating the natural history of cognitive changes, along with better ways of diagnosing and treating cognitive problems in MS. It is hoped that in the future, people with MS will have access to a combination of disease-modifying therapies, symptomatic treatments, and cognitive rehabilitation that will modify the course and impact of the cognitive changes in MS.
Sir William Thomson, later known as Lord Kelvin An introduction to the Kelvin Probe The Kelvin Probe is an extremely sensitive analytical tool measuring changes in contact potential difference (cpd) between a reference material and a sample to less than 0.001 V. The essence of the cpd is the difference in fermi-levels (in the simple case of a metal this is the energy of the most energetic electron within the outer electron band with respect to the vacuum level, Evac). If we assume that the reference material fermi-level is unchanged during the measurement (in practical situations this may have to be determined via control experiments), then the changes in contact potential difference of the Kelvin 'Junction' can be wholly ascribed to changes occurring at the Depending upon the direction of your study you may find this term expressed in different ways: contact potential, fermi-level, work function, surface potential, corrosion potential, surface dipole, etc. I would be delighted to learn of other expression's to extend this The Kelvin method was first postulated by the renowned scottish scientist Sir William Thomson, later to be known as Lord Kelvin, in 1898 when he presented a public lecture to the British Institution on the 'contact electrification of metals'. Over a century later the method he proposed is at the forefront of materials research and start-of-the-art equipment development. In essence the method is simplicity itself: take two conducting materials, allow them to come into electrical contact, then sense any flow of charge from one material to the other. Kelvin used two large metal plates and a gold leaf electroscope to demonstrate this surface charging effect: he showed that a potential is generated between the surfaces of two conductors when they are brought into electrical contact. This experiment forms the basis of the Kelvin Probe which has been developed into a highly sensitive tool for analysing the surface properties of materials. The range of materials it can be applied too is constantly increasing: metals, alloys, semiconductors and even insulators, yes insulators!
Intermediate colors are made up of yellow-orange, orange-red, red-violet, blue-violet, blue-green and yellow-green. These colors are combinations of both primary and secondary colors.Continue Reading Secondary colors are orange, green and violet, while primary colors are red, blue and yellow. Primary colors are the basis for all of the other colors that exist on a color wheel. No matter what shade, they will be some form of red, blue or yellow. The secondary colors are direct combinations of these three colors. Orange is made by mixing yellow and red; green is made by mixing yellow and blue; and violet is made by mixing red and blue. The colors that make up these intermediate, secondary and primary colors are often found on color wheels. Color wheels show the way that colors transfer between each other and combine to make different tones and shades. Complementary colors are ones that are next to each other on a color wheel. They complement one another and provide a good decorating base. Contrasting colors are opposite from each other on the color wheel and generally match, but should not be used excessively. The color wheel is used in decorating, painting and, in the world of cosmetology, for hair coloring purposes.Learn more about Colors
Today is the birthday of Dorothy Crowfoot Hodgkin O.M. FRS who was awarded the 1964 Nobel Prize for her determinations by X-ray techniques of the structures of important biochemical substances What does it look like? What is it and how was the structure found? This is Vitamin B-12. A vitamin is an organic compound vital to the nutrition of an organism. For any particular organism if the substance cannot be synthesized in sufficient (but very small) amounts, the vitamin must then be obtained from the diet. For instance, Vitamin D is a vitamin in humans because in certain circumstances, particularly low exposure to UV radiation, the normal synthesis of the substance does not occur and it must be consumed from dietary sources to meet metabolic requirements. Vitamin B12 is chemically the most complex vitamin with a group of closely related substances functioning in the organism to provide the necessary source of cobalamin to vital enzymatic pathways of the metabolism. The recommended dietary intake in humans varies but is in the range of 1-3 micrograms (millionths of a gram) per day. Vitamin B12 deficiency can result either from an inadequate dietary intake, or from conditions in which the ability to absorb the nutrient is diminished. Biosynthesis of vitamin B12 only occurs in bacteria and archaea and passes into the food chain via due to bacterial symbiosis. The common features of the Vitamin B12 group of compounds are (i) the corrin ring (similar to the porphyrin http://en.wikipedia.org/wiki/Porphyrin ring which binds to the metals present in haem, chlorophyll and cytochrome) which has (ii) a cobalt atom bound in its centre. (iii) One of the carbon atoms on the “outside” of the corrin ring carries to a long chain of atoms ending in a dimethylbenzimidazole group which joins on to the cobalt through one of its nitrogen atoms on one side of the corrin ring and on the other side of the corrin, a sixth substituent bonds to the cobalt atom – this is the site of the biological reactivity of Vitamin B12 and can be occupied by hydroxyl (-OH), methyl (-CH3), cyano (-CN) or 5’-deoxyadenosyl (via its C5’ atom). All of these compounds form crystals which are deep red in colour. The complete structure of vitamin B12 was determined by Dorothy Hodgkin and her collaborators by means of X-ray crystallographic methods. Using structures from fragments and combining knowledge of the chemistry and with access to early computer based fourier methods, the structure was fully revealed. It is interesting to note the sharing of information which went on between the crystallographic groups and the chemists who were engaged in studying the structure. The documents demonstrate that the two different approaches were to be published simultaneously and Dorothy maintained an inclusive and generous approach to publication of this important structure. Dorothy learned that Alexander Todd (Nobel Prize for Chemistry 1957) had agreed to present a talk about “some new nitrogen-containing compounds” at a meeting of the Chemical Society which he had not mentioned to Dorothy when he was in Oxford a day or two prior to this for the purpose of discussing the publication of the structure. When Dorothy got wind of this talk, she attended and finding that he was announcing the structure, at the end of the talk Dorothy stood up and explained how it had been done. After this occurrence, Dorothy insisted that members of her crystallographic group went wherever Todd was speaking so that they could give a comment at the end. A study designed to isolate the substance in liver which cured anaemia in dogs (iron), along the way revealed the presence of a different substance which cured pernicious anaemia in humans. For several years sufferers of pernicious anaemia were required to consume large amounts of raw liver or drink “liver juice” to treat their condition. The 1934 Nobel Prize in Physiology or medicine was awarded to Whipple, Minot and Murphy for their work in pointing the way to a treatment for this condition. In 1928 Edwin Cohn prepared an extract that was 50-100 times more effective in the treatment of the disease than raw liver products and together these discoveries led to the identification of the group of compounds known as Vitamin B12
This module explains why DNA sequencing information is important for the biological sciences. It provides a brief description of the technical challenges of DNA sequencing. Students learn the basic principles of sequencing-by-synthesis, which is a widely used next-generation sequencing (NGS) technology. Students will do an online activity that simulates sequencing strings of DNA. Review the Process of DNA Sequencing 2. G will pair with C; the spot will light up yellow 3. Blue (because T pairs with A) 4. Green because green C pairs with G 5. Red indicates A, and A pairs to T—so the unknown nucleotide must be a T 6. Two strings (the ones that are blue); because they paired with T, the strings must each have an A. Putting It All Together To make this activity easier, provide a datasheet that depicts the flow cell and outlines the spatial positions of each string. Also, you can modify the sheet so that students have the exact needed number of copies of the datasheet to fill out in order to take them through the five cycles (multiplied by four colors = 20 copies of the flow cell to record the colors as they sequence the strings). Answers to the last slide in the Challenge a) Five spatial positions, which means there were five strings (each position is a clump of copies of a single string) b) Five cycles, which means that it sequenced five bases along each of the 5 strings c) The color sequence gives you the nucleotides that paired with the bases on the unknown strings. Because of base-pairing rules, when you know which color is attached to which base, you can figure out the identity of the unknown nucleotide the colored base paired with. The solution to the sequence of the strings can be viewed here (PDF).
Individual differences \| Methods \| Statistics \| Clinical \| Educational \| Industrial \| Professional items \| World psychology \| Interaction is a kind of action which occurs as two or more objects have an effect upon one another. The idea of a two-way effect is essential in the concept of interaction instead of a one-way causal effect. Combinations of many simple interactions can lead to surprising emergent phenomena. It has different tailored meanings in various sciences. Casual examples of interaction outside of science include: - communication of any sort, for example two or more people talking to each other, or communication among groups, organisations, nations or states: trade, migration, foreign relations, transportation; etc. - the feedback during operation of a machines such as a computer or a tool, for example the interaction between a driver and the position of his or her car on the road: by steering the driver influences this position, by looking this information returns to the driver; In psychology the term may refer to: - Double bind interaction - Drug interactions - Employee interaction - Heterosexual interaction - Human animal interaction - Human computer interaction - Interhemispheric interaction - Interaction analysis (statistics) - Interaction variance - Interpersonal interaction - Interspecies interaction - Social interaction - Supervisor employee interaction - Teacher student interaction Chemistry and medicine Edit In medicine, most medications can be safely used with other medicines but particular combinations of medicines need to be monitored for interactions, often by the pharmacist. In molecular biology, the knowledge on gene/protein interaction among themselves and with their metabolites is referred to as molecular pathways. Interactions between medications fall generally into one of two main categories; pharmacodynamic (involving the actions of the two interacting drugs), and pharmacokinetic (involving the absorption, distribution, metabolism, and excretion of one or both of the interacting drugs upon the other). Sometimes two or medications are used together to create an extra effect - e.g. two different pain killers to provide more complete pain control. These interactions are usually intentional but need to be monitored by the doctor because patients can end up with more effect than is actually required. Sometimes two or more medications work against each other. These interactions are usually well-known and avoided unless both medicines are essential. Careful monitoring is used to prevent problems from the results of the interaction. In medicine, most medications can be safely used with other medicines, but particular combinations of medicines need to be monitored for interactions, often by the pharmacist. Interactions between medications (drug interactions) fall generally into one of two main categories: - pharmacodynamic : Involving the actions of the two interacting drugs. - pharmacokinetic : Involving the absorption, distribution, metabolism, and excretion of one or both of the interacting drugs upon the other. In terms of efficacy, there can be three types of interactions between medications: additive, synergistic, and antagonistic. Additive interaction means the effect of two chemicals is equal to the sum of the effect of the two chemicals taken separately. This is usually due to the two chemicals acting on the body in the same way. Examples are aspirin and motrin, alcohol and depressant, tranquilizer and painkiller. Synergistic interaction means that the effect of two chemicals taken together is greater than the sum of their separate effect at the same doses. An example is Pesticide and Fertilizer, the biological effect is devastating. Antagonistic interaction means that the effect of two chemicals is actually less than the sum of the effect of the two drugs taken independently of each other. This is because the second chemical increases the excretion of the first, or even directly blocks its toxic actions. Antagonism forms the basis for antidotes of poisonings. In communications, interactive communication occurs when sources take turns transmitting messages between one another. This should be distinguished from transactive communication, in which sources transmit messages simultaneously. In sociology, social interaction is a dynamic, changing sequence of social actions between individuals (or groups) who modify their actions and reactions due to the actions by their interaction partner(s). Social interactions can be differentiated into: - accidental - not planned and likely not repeated. For example, asking a stranger for directions or shopkeeper for product availabity. - repeated - not planned, bound to happen from time to time. For example, accidentally meeting a neighbour from time to time when walking on your street; - regular - not planned, but very common, likely to raise questions when missed. Meeting a doorman or a security guard every workday in your workplace, dining every day in the same restaurant, etc. - regulated - planned and regulated by customs or law, will definitely raise questions when missed. Interaction in a workplace (coming to work, staff meetings, etc.), family, etc. Social interactions form the basis for social relations. - Main article: Interaction (statistics) See also Edit - Interaction design pattern - Interactive computation - Symbolic interactionism \|This page uses Creative Commons Licensed content from Wikipedia (view authors).\|
The narrow-leafed campion is not a particularly long-lived flower; and yet, the parents of the campion pictured here blossomed in the presence of mammoths and woolly rhinos. How is that possible? The explanation is simple, but the circumstances are unprecedented. The fruits that gave rise to the flowers you see here first fell to the Earth during the late Pleistocene. They were snatched up by a foraging squirrel, hidden underground, and subsequently entombed in ice. Now, more than 30,000 years later, the fruits have been revivified, giving rise to one of the most incredible biological anachronisms the world has ever known. It's worth pointing out that ancient frozen seeds have been found before; they've even been grown into full-fledged plants. What makes this little arctic flower (which goes by the scientific name of Silene stenophylla) so impressive is just how old it is. Radiocarbon dating suggests that the fruit that generated this plant had been tucked away in the tundra of northeastern Siberia for 31,800 years. That blows the old record (previously held by a date palm seed) out of the water by around 30,000 years. The fruit that gave rise to these flowers started its journey in the foraging paws of a Pleistocene-era squirrel. Squirrels like to hoard things — food, to be precise. This is as true today as it was 30,000 years ago. So when a research team led by David Gilichinsky decided to go foraging for the spoils of ancient squirrels along the banks of Russia's lower Kolyma river, they encountered no shortage of food stores; some of the burrows that the researchers raided contained upwards of 600,000 seeds and fruits. These stockpiles have been preserved at around -7 degrees Celsius since they were first buried all those years ago; entombed by layer-upon-layer of permanently frozen soil, it's unlikely that these food stores thawed even once in the time between when they were first inhumed and when they were recovered by Gilinchinsky and his team. Incredibly, when researcher Svetlana Yashina extracted the placentas from the recovered fruits, she was able to coax the tissue into producing roots and shoots. (The placenta is where the fruit's seeds attach and receive nutrients, labeled "P" in image A, and shown with attached seeds in image B.) She potted the plants and waited. One year later, flowers emerged. The plants bore fruit that set seed, and from those seeds a new generation of plants emerged. After more than 30,000 years, this ancient lineage had simply picked up right where it left off. The researchers regard the discovery as compelling evidence for the existence of other, as-of-yet discovered biological anachronisms that may be locked away in layers of permanently frozen soil, which is thought to cover nearly one fifth of the Earth's surface. These naturally occurring fruit and seed stores, explain the authors, can be thought of as nature's version of man-made seed repositories, like Norway's Svalbard Global Seed vault, where researchers are working to amass a stockpile of the world's ever-dwindling plant diversity. "Naturally occurring permanently frozen sediments offer an important opportunity for the discovery of wild plant species, preservation of biological material, studying the conditions for cryopreservation, and developing germplasm collections," write the researchers in today's issue of Proceedings of the National Academy of Sciencies. "We consider it essential to continue permafrost studies in search of an ancient genetic pool, that of preexisting life, which hypothetically has long since vanished from the earth's surface." Images by Yashina et al. via PNAS
Spiderworts (Tradescantia) are a genus of an estimated 71 species of perennial plants in the family Commelinaceae, native to the New World from southern Canada south to northern Argentina. Though sometimes accounted a weed, spiderwort is cultivated for borders and also used in containers. Where it appears as a volunteer, it is often welcomed and allowed to stay. The genus takes its name from John Tradescant the elder, an 17th century English plant collector and nurseryman. The first species described, Virginia Spiderwort T. virginiana, is native to the eastern United States from Maine to Alabama, and Canada in southern Ontario. Virginia Spiderwort was introduced to Europe in 1629, where it is cultivated as a garden flower. The Western Spiderwort T. occidentalis is listed as an endangered species in Canada, where the northernmost populations of the species are found at a few sites in southern Saskatchewan, Manitoba and Alberta; it is however more common further south in the United States south to Texas and Arizona. The three species of Wandering Jew, one native to eastern Mexico, also belong to the tradescantia genus. Other names used for various species include Spider-lily, Cradle-lily, Oyster-plant and Flowering Inch Plant. They are weakly upright to scrambling plants, growing to 30-60 cm tall, and are commonly found individually or in clumps in wooded areas and fields. The leaves are long, thin and bladelike to lanceolate, from 3-45 cm long. The flowers are white, pink or purple but most commonly bright blue, with three petals and six yellow anthers. The sap is mucilaginous and clear. A number of the species flower in the morning and when the sun shines on the flowers in the afternoon they close up, but the flowers can remain open on cloudy days until evening. The cells of the stamen hairs of some Tradescantia are colored blue, but when exposed to sources of ionizing radiation such as gamma rays, the cells mutate and change color to pink; they are one of the few tissues known to serve as an effective bioassay for ambient radiation levels. Pests and Diseases Front view of leaves of Tradescantia pallida cv. "Purple Heart". \|Wikiversity is collecting bloom time data for Tradescantia on the Bloom Clock\|
When designing electrical circuits engineers use a diagram to model the circuit that consists out of the electronic components in form of symbols. Such a diagram is known as a “circuit diagram,” and there are two basic styles. The first—and easiest to read for the layperson—is a pictorial diagram. In a pictorial diagram, components of the circuit, like batteries, resistors, and voltmeters, are indicated by detailed drawings that accurately depict the components. The battery is represented by a drawing of a battery, the voltmeter by a drawing of a voltmeter, and so on. Of course, drawing a voltmeter or a battery on every circuit diagram is neither practical nor necessary for professionals, who deal frequently with these diagrams. So rather than pictorial circuit diagrams, professionals mostly deal with what are known as “schematic diagrams.” These use circuit symbols to represent the parts of the circuit. There is a standardized symbol for a battery, a resistor, and capacitor, and so forth. The symbols are quick and easy to draw, and convey the same information as more detailed drawings. Within a circuit, it’s possible to have many different components—batteries, inductors, and capacitors being just a few of them. Each of these components has its own circuit symbol. In the other articlesis an overview of the most common circuit symbols, with a description of each circuit symbol and an explanation of what it means.
Researchers led by Paul Muralt of the Swiss Federal Institute of Technology have carried out a review of the field of ceramic materials, exploring the critical role that piezoelectric materials play in advancing technology. Piezoelectric materials are functional ceramic materials that play a special role in telecommunication and ultrasonic imaging since they have the ability to efficiently transform electrical signals into mechanical vibrations, and vice versa. Piezoelectricity refers to the ability of some materials, notably crystals and ceramics, to generate electricity when compressed. Over the last twenty years, micro-electro-mechanical systems (MEMS) have become a proven technology with many applications. Combined with piezoelectric films (piezo-MEMS) a number of important advantages have been achieved. The intrinsic electro-mechanical quality of piezo-MEMS based on AlN thin films resulted in a breakthrough in mobile phone technology, allowing for smaller phones, and a lowering of microwave radiation intensity. Among piezoelectric thin film materials, the Swiss researchers note that PZT has recently shown much promise and will likely be used for mass applications. Ultrahigh resolution ink-jet printing heads are expected to be the next break-through in piezo-MEMS. At different frequencies, it is possible that PZT MEMS could be used for motion sensors, vibration sensors, and optical mirrors, wristwatch rotary drives, and buzzers. "There are many other applications under investigation, such as energy harvesting, oscillatory systems for clocks, mirror arrays, and scanners," the authors conclude. The study, published in the Journal of the American Ceramic Society, illustrates the use of ceramic materials in the development of technological devices, including mobile communication and ultrasonic imaging.
The Nationalist Movements in England were organized mass movements emphasizing and raising questions concerning the interests of the people of India. In most of these movements, people were themselves encouraged to take action. Due to several factors, these movements failed to win Independence for India. However, they did promote a sense of nationalism among the people of the country. The failure of these movements affected many people as they withdrew from Government offices, schools, factories and services. Though they did manage to get a few concessions such as those won by the Salt March in 1930, they did not help India much from the point of view of their objective. vjv, Nizamiyat, the local nawabs of Oudh and Bengal and other smaller powers. Each was a strong regional power influenced by its religious and ethnic identity. However, the East India Company ultimately emerged as the predominant power. One of the results of the social, economic and political changes instituted in the country throughout the greater part of 18th century was the growth of the Indian middle class. Although from different backgrounds and different parts of India, this middle class and its varied political leaderships contributed to a growing "Indian" identity". The realisation and refinement of this concept of national identity fed a rising tide of nationalism in India in the last decades of the 19th century.
Fluoridation and Dental Health In addition, people with certain conditions may be at increased risk of tooth decay and would therefore benefit from additional fluoride treatment. They include people with: - Dry mouth conditions Also called xerostomia, dry mouth caused by diseases such as Sjögren's syndrome, certain medications (such as allergy medications, antihistamines, antianxiety drugs, and high blood pressure drugs), and head and neck radiation treatment makes someone more prone to tooth decay. The lack of saliva makes it harder for food particles to be washed away and acids to be neutralized. - Gum disease, also called periodontitis, can expose more of your tooth and tooth roots to bacteria increasing the chance of tooth decay. Gingivitis is an early stage of periodontitis. - History of frequent cavities: If you have one cavity every year or every other year, you might benefit from additional fluoride. - Presence of crowns and/or bridges or braces: These treatments can put teeth at risk for decay at the point where the crown meets the underlying tooth structure or around the brackets of orthodontic appliances. Ask your dentist if you could benefit from additional fluoride. Are There Risks Associated With Fluoride Use? Fluoride is safe and effective when used as directed but can be hazardous at high doses (the "toxic" dosage level varies based on an individual's weight). For this reason, it's important for parents to carefully supervise their children's use of fluoride-containing products and to keep fluoride products out of reach of children, especially children under the age of 6.
Large herbivorous Sauropods and equally large carnivorous Carnosaurs lived during the Jurassic period, as well as smaller, quicker animals. Additionally, the first birds evolved from dinosaurs with simple feathers during the Jurassic period.Continue Reading The largest animals to live during the Jurassic period were Sauropods. These large herbivores, such as Brachiosaurus and Apatosaurus, were some of the largest land animals in geologic history, sometimes weighing in at over 80 tons. Despite their proportionally small heads and brains, Sauropods were very successful and Sauropod remains occupy every modern continent, except Antarctica. The immense size of the Sauropods was an excellent defense against the large carnivores of the time, such as Allosaurus. Like modern predators that hunt prey larger than themselves, Allosaurus most likely hunted very young or injured animals. The plated Stegosaurus was another Jurassic-era herbivore equipped to defend itself against predators. Interestingly, the dinosaur associated most famously with the Jurassic period due to modern entertainment, Tyrannosaurus rex, did not evolve until after the Jurassic period. This giant creature lived during the Cretaceous period. Small, fast dinosaurs, such as coelurosaurs, were also common in the Jurassic era. Many of these smaller dinosaurs had simple feathers. The late Jurassic era saw the evolution of feathered Theropods into the first birds, such as Archaeopteryx.Learn more about Dinosaurs
“The discovery of such material, and understanding of the nature of the existence of the ground bright exciton, open the way for the discovery of other semiconductor structures with bright ground excitons,” said Dr. Alexander Efros, research physicist, NRL. “An optically active bright exciton in this material emits light much faster than in conventional light emitting materials and enables larger power, lower energy use, and faster switching for communication and sensors.” The work, which was partially sponsored by the Office of Naval Research through a program managed by Dr. Chagaan Baatar, studied lead halide perovskites with three different compositions, including chlorine, bromine, and iodine. Nanocrystals made of these compounds and their alloys can be tuned to emit light at wavelengths that span the entire visible range, while retaining the fast light emission that gives them their superior performance. Semiconductors emit light when bound pairs of electrons and holes, known as excitons, recombine in a process called radiative decay. “In all known semiconductors and semiconductor nanostructures, the lowest energy state for a bound electron-hole pair is a ‘dark’ state,” said Efros. “This means the material emits light slowly and weakly.” Because in perovskite nanocrystals the lowest energy exciton is bright, the time it takes for the electron and hole to recombine and emit light, known as their radiative lifetime, is 20 times faster than conventional materials at room temperature and 1000 times faster at cryogenic temperatures. It is known, that quantum-dot based LEDs, or QLEDs, can suffer from “droop,” or reduced efficiency, at high pumping intensity due to processes that dissipate the energy of excitons before they have time to emit light. The decreased radiative lifetime should make it possible for LEDs based on these perovskites to use all of the energy input to create light before it is dissipated through slower processes. “The increased rate of light emission of these materials holds great promise for various technological applications that rely on LEDs and lasers,” Efros said. “In principle, the 20 times shorter lifetime could therefore lead to 20 times more intense LEDs and lasers.” The power of a laser depends on the gain of the material it is made of, and this gain is proportional to the radiative emission rate. Communication in free space using visible light, which makes it possible to transmit information in tight beams for long distances without fiber optic or copper cables, would also benefit from the increased light emission rates. “The maximum bandwidth of the communication system is limited by the rate at which the LEDs can turn on and off, and the shorter radiative lifetime translates directly into faster switching and therefore a higher data transmission rate,” says Efros. The success of this work was due to a close collaboration between several experimental groups in Zurich, Switzerland and U.S. theoreticians. The industrial, academic and laboratory research team that contributed equally to this publication include: Michael A. Becker, Thilo Stöferle, Rainer F. Mahrt and Gabriele Rainò from IBM Research, Zurich, Switzerland; David J. Norris from Optical Materials Engineering Laboratory, ETH Zurich, Zurich, Switzerland; Roman Vaxenburg and Andrew Shabaev from Computational Materials Science Center, George Mason University, Fairfax, Virginia; Georgian Nedelcu and Maksym V. Kovalenko from Institute of Inorganic Chemistry, Department of Chemistry and Applied Bioscience, ETH Zurich, Zurich Switzerland and Laboratory of Thin Films and Photovoltaics, Empa – Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland; Peter C. Sercel from T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California; Michael J. Mehl from U.S. Naval Academy, Annapolis, Maryland; and John G. Michopoulos, Samuel G. Lambrakos, Noam Bernstein and John L. Lyons in addition to Alexander Efros from the Center for Computational Materials Science, Naval Research Laboratory, Washington, D.C. Full details of this research entitled “Bright triplet excitons in cesium lead halide perovskites,” can be found in the January 11, 2018 edition of Nature (doi:10.1038/nature25147).
Discover the importance of comprehension in your child’s development, and find out how you can boost his comprehension with a few simple exercises. As parents, we always want what’s best for our children. We try to provide them with the best that the world has to offer so that they are equipped with the right skills and traits to overcome whatever comes their way. We guide them in their homework, we give them reading comprehension exercises, we do anything and everything we can to help them grow. We focus on building our children’s intelligence. But future success goes beyond just mere intelligence. EQ is just as important as a high IQ. With that in mind, it is nurturing a combination of mental, physical and emotional development in our children that should be our goal as parents. We need to help our children to be future-ready and equipped with all eight signs of mental and emotional development – memory, communication, social skills, vocabulary, comprehension, problem-solving, attention, self-regulation development. Each one is crucial, but comprehension is one of the most important signs and one you can take action on right away. What Exactly Is Comprehension? Reading and comprehension may be words that are often used together, but they are not the same thing. Reading refers to the ability to decode text into words or spoken words. Comprehension is about understanding and processing words and language. Comprehension skills are crucial to your child’s future. It helps children enjoy reading and is an effective way to improve their academic performance. But it is also a tool of discovery that they can use for their entire life. Imagine your child reading through an employment contract, and not able to understand what is written. Or reading a book and being unable to learn the important life lessons contained within. Regardless of the profession your children choose in the coming decades ahead, comprehension plays an important role. Improving your child’s comprehension skills are easier than you think. Watch out for important milestones, practice these exercises and provide your children with the right diet and nutrition and they will be on their way to a bright future. Recommended activities for children 1 year and above. Age 1: Building Blocks The child goes through the most changes in their early years. Building blocks for better comprehension skills start as early as now. At one year old, they will communicate by pointing, using sign language and babbling. Even though your child is not saying anything, he is comprehending more than you think. Try talking about her favourite food or toy and see a smile come across his face. This is a sign that your child has started comprehending.1 How can I help my one-year-old comprehend better? Age 2: Fun and Games Your toddler is growing by leaps and bounds at this stage. By age two, most toddlers have a vocabulary of 50 words or more, are able to put together two to three-word phrases and comprehend simple instructions like “Go here,” and “Put the ball down.” 1 How can I help my two-year-old comprehend better? Age 3: Look Who’s Talking Your three-year-old is a great conversationalist. He probably has some 600 to 900 words in his vocabulary by now.3 This is also the stage when he starts communicating his emotions and feelings. And you can look forward to him delighting you with stories of how his day went every day. How can I help my three-year-old comprehend better? Age 4: Language When we speak of language comprehension in four-year-olds, we are talking about understanding spoken words and sentences on a greater scale. This is when preschoolers develop their vocabulary and learn about language structure. How can I help my four-year-old comprehend better? Age 5: Ready for the Future By the age of five, 90% of your child’s brain growth is already complete.6 Most children this age have greater self-control and display creativity. They are also more independent and are content with playing with their toys alone, without adult supervision. They are also able to express their emotions and frustrations more articulately. 7 How can I help my five-year-old comprehend better? Parents, there are countless ways to help improve your children’s comprehensions skills, but nothing can replace the need for basic nutrition. The first five years of your child’s life is where most of the brain development happens. His brain will never grow this fast again. 8 Make sure you don’t miss out on providing your child with the nutrition he needs to fully develop his mental and physical development. When children don’t receive proper nourishment during this crucial period, it could lead to slower language and comprehension development as well as lower I.Q.9 6Lenroot RK and Giedd JN. Neuroscience and Biobehavioral Reviews 2006;30:718-729
A faraway gas giant planet that's famous for being strangely "puffy" appears to have clouds that are made of tiny bits of sand. The sand likely acts as water does on Earth, falling like rain towards the planet's hotter interior and then evaporating back up to form clouds once more, according to a new report published online by the journal Nature. The discovery showcases one of the many kinds of bizarre clouds that scientists say probably exist out beyond our solar system. Even though astronomers theoretically knew that clouds could form out of substances like rock or metal or salt, "now here we can actually look at it," says Laura Kreidberg, an astronomer at the Max Planck Institute for Astronomy in Germany who studies atmospheres of distant planets but was not part of this research team. "It makes the weirdness of a cloud made out of rock feel so real," says Kreidberg. She says scientists were eager to see what they might find when the James Webb Space Telescope (JWST) turned toward the oddball planet known as WASP-107b. Discovered in 2017, this planet orbits a star about 212 light-years away that's a little smaller and cooler than the Sun. The planet is so close to its star that it orbits once every 5.7 days, and temperatures there reach around 900 degrees Fahrenheit. Even though the planet is about the size of Jupiter, it is much lighter, with about the same mass as Neptune. Its low density led some scientists to call it a "cotton candy" or "super puff" planet. "This is a very fluffy planet. And so the fact that it's so fluffy implies that we can really look very deep inside its atmosphere," says Leen Decin, director of the Institute of Astronomy at KU Leuven in Belgium and one of the lead scientists for this new study. That's because starlight filtering through an atmosphere can reveal what it's made of, and the size of this atmosphere meant there'd be ample starlight to analyze. In the past, scientists have struggled to understand the nature of clouds because they block the starlight from coming through. "This happens a lot. Many of the planets that we have observed have really strong evidence for some kind of clouds or haze," says Kreidberg. "But up until now, it's been very difficult to determine exactly what type of cloud we're looking at." With the powerful JWST, which peers at the universe in search of infrared light, scientists have a brand-new tool to help do that. Kreidberg explains that the tell-tale features from clouds are mainly in the infrared, which the Hubble Space Telescope couldn't see. JWST can see those features, plus it can also make much more precise measurements than Hubble, as it has a bigger light-collecting mirror. And what the astronomers' new telescope found on WASP-107b quickly upended their expectations. For example, Decin says they'd anticipated seeing a lot of methane in the atmosphere. But nope — they didn't detect any. Instead, they saw signs of sulfur dioxide, which Decin calls "the smell of burning matches." JWST recently detected that chemical on another, hotter planet, WASP-39b, but Decin says researchers hadn't thought it would form at these lower temperatures. And the composition of the clouds turned out to be a real stunner, with silicate material behaving like water does on Earth. "We are sure that these sand clouds can form," Decin says, adding that the particles of sand likely are smaller than the ones found on a sandy beach. A spaceship would find it hard to navigate in the planet's superfast winds, she says, with climate simulations suggesting that winds would likely go over 10,000 miles per hour. But if you could fly in a spaceship towards this hot, churning planet, she says, "I think you would feel, literally, the streams of sand around you." In the past, researchers have taken what they know about chemical elements and made predictions about what kinds of peculiar clouds might exist on distant planets. But these were just educated guesses. With JWST's direct detection of sand clouds on WASP-107b, says Kreidberg, "we know for sure they're there." This could be just the beginning of a bevy of otherworldly cloud discoveries. Astronomers pondering one far-off planet, for example, suggested that it might have clouds made of liquid metal and rain made of rubies and sapphires. "They are lacking any observational confirmation on the cloud composition," says Decin, but that's another hot planet that researchers want to study with JWST, to see if precious gems could really fall like rain. AILSA CHANG, HOST: Clouds are pretty common on planets. Earth has clouds made of water. Venus has clouds made of sulfuric acid. And astronomers have wondered what kinds of clouds might exist on planets outside of our solar system. NPR's Nell Greenfieldboyce reports that they've just been able to probe the clouds on one distant planet, and what they found was sand. NELL GREENFIELDBOYCE, BYLINE: The planet is called WASP-107b. It orbits a star that's a little smaller and cooler than our sun, over 200 light years away. The planet is a gas giant that's about the size of Jupiter, but far less dense, leading some to refer to it as a cotton candy planet. Leen Decin is with the Institute of Astronomy from the Leuven University in Belgium. She says the planet is fluffy. LEEN DECIN: The fact that it's so fluffy implies that we can really look very deep inside its atmosphere. GREENFIELDBOYCE: The Hubble Space Telescope saw signs that this planet had some kind of cloud layer. DECIN: But there was no way of saying what could be the composition of that cloud layer. GREENFIELDBOYCE: Recently, though, she and her colleagues checked out that planet with the James Webb Space Telescope. This powerful telescope can make more precise measurements and sees a different kind of light that can reveal more about clouds. In a new report published online by the journal Nature, they say the clouds are made of silicates - basically sand. It seems that, on this super hot planet, sand particles act like water does here on Earth. The tiny bits of sand form clouds and rain down to a hotter interior. Then they evaporate and travel back up to form clouds once more. Laura Kreidberg is an astronomer with the Max Planck Institute for Astronomy who wasn't part of the research team. She says, in the past, scientists have theorized about all kinds of strange clouds that planets might have - clouds made of salt or rock. LAURA KREIDBERG: But there's a difference between having an idea - just a theory - and detecting it with your own eyes. And so for me, that was the most exciting part of this - is that we can finally see for ourselves exactly what this cloud is made out of. GREENFIELDBOYCE: And this could be just the beginning of a bevy of otherworldly cloud discoveries. Astronomers who've pondered another far-off planet, for example, suggested that it might have clouds made of liquid metal and rain made of rubies and sapphires. They want to check that one out with the James Webb Space Telescope to see if precious gems might really fall like rain. Nell Greenfieldboyce, NPR News. (SOUNDBITE OF JEAN CARNE, ET AL. SONG, "THE SUMMERTIME") Transcript provided by NPR, Copyright NPR.
While coding and programming have a common origin, both of them terms have different meanings. Code involves the creation of software courses and switching human terminology into binary commands. Coding requires a skillful approach as well as the knowledge of an intermediate dialect. Programmers should the basic common sense behind their particular chosen dialect, the syntax and the key keywords. There are pros and cons to each. Here are some of this key dissimilarities between development and code. Programming and coding will be two several jobs, although these two terms sound similar, they are really very different. Often , people befuddle the two terms and utilize them interchangeably, but the difference amongst the two is usually significant. You can learn coding and also programming without necessarily studying either one individually. Both of these expertise are essential pertaining to development of software applications and the maintenance of custom-coded applications. So , https://www.deadbeats.at/guitar-hero-customer-review/ which one if you decide to focus on? Coding involves producing computer applications that translate machine-readable code. Though basic coding is possible with wordpad or perhaps online editors, the real skill comes in if you are writing sophisticated programs or perhaps applications. A programmer contains the knowledge of the programming different languages, and the ability to find and resolve bugs. Although coding is definitely not for everybody. It can result in a fulfilling job if you’re well-rounded in software development. The primary difference among programming and code is that coding uses machine code, when development uses our language to communicate with a computer. The latter uses binary codes to talk to hardware. Whilst coding calls for using binary codes, programming is more complicated. The difference is in the language as well as the complexity of programming. The difference is a subtle one, but one that might affect your career choice. Also remember that coding can be given to any sector, not just to software.
For months, wildfires raging in Victoria, Queensland, and New South Wales have darkened skies in eastern Australia. In mid-January 2020, the skies turned a distinctive shade of orange for a different reason, as an enormous dust storm swept across the continent. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured a natural-color image (top) showing a front of thick dust stretching thousands of kilometers across Australia on January 11, 2020. The Operational Land Imager (OLI) on Landsat 8 acquired a higher-resolution image of the dust front in Queensland near Eromanga (below) about an hour earlier. Strong winds associated with a passing low-pressure trough and storm system triggered the dust storm. Months of unusually dry weather have parched the soils, making it easier for winds to lift clay-sized (less than 4 micrometers), silt-sized (4 to 62.5 micrometers), and sand-sized (62.5 micrometers to 2 millimeters) dust particles high into the air. While dust storms are relatively common in Australia in the spring and summer, storms on this scale are not. “This is a massive continental wide storm that continued across the Tasman Sea and seems to have reached New Zealand, after which time it made a clockwise whirl in the Southern Ocean,” said Patrick De Deckker, an emeritus professor at Australian National University who has written extensively about Australian dust storms. “Most of the dust seems to have come from the Lake Eyre basin, which is the major source of Australian dust.” The last Australian dust storm on this scale was the “Red Dawn” storm that struck in 2009, according to De Deckker. Severe dust storms can pose a range of health risks to humans. Reduced visibility often causes increases in traffic accidents. Inhaling dust can cause or exacerbate respiratory health problems. Dust is also known to sometimes carry bacteria, fungi, and viruses capable of spreading disease. Meanwhile, the economic costs of dust storms can be extensive. Blowing dust can reduce the fertility of farmland, harm or kill animals, and damage crops in the field. It regularly halts transportation systems, slows solar power production, and damages homes and infrastructure. NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey and MODIS data from NASA EOSDIS/LANCE and GIBS/Worldview. By Adam Voiland.
Gastroschisis is a birth defect that causes a baby's intestines to develop outside of the body. This condition is considered rare, but recent studies show that it is becoming more common, especially in younger mothers. According to the Centers for Disease Control and Prevention (CDC), an estimated 1,871 babies are born with this condition each year. Babies with gastroschisis require surgery to place the bowels back into the stomach and must stay in the hospital until they have fully recovered. Most cases of gastroschisis can be successfully treated and usually do not cause any long-term complications, with the survival rate being over 90%. However, some babies may need temporary medical assistance to help them receive proper nutrition while they heal.What is Gastroschisis? Gastroschisis is a birth defect that affects the baby's abdominal wall. It occurs when the abdominal wall does not develop correctly and forms an opening near the belly button. This causes the intestines to be pushed out through the hole and develop outside the body in the amniotic fluid. The size of the abdominal hole can vary from small to large, with the average size being 1-2 inches, and is most often found on the right side of the belly button. Gastroschisis can result in the intestines becoming irritated, shortened, twisted, or inflamed because there is no protective sac covering them while being exposed to the amniotic fluid. Gastroschisis is labeled as either "simple" or "complex". In simple cases, only the intestines form outside the body. For complex cases, the bowels may be damaged from the amniotic fluid and other organs, such as the stomach and liver, also protrude out of the opening. Fortunately, simple cases are far more common than complex ones, but even severe cases can be fixed with surgery. Babies with severe gastroschisis are more likely to experience complications after receiving treatment.What Causes Gastroschisis? Currently, the underlying cause of gastroschisis is still unknown. It's been suspected that the condition is linked with changes in the baby's genes or chromosomes. It could also be caused by a combination of factors, including what the mother eats or drinks, what medication she's using, and possibly other environmental factors. The CDC has been conducting research on gastroschisis and recently found that using alcohol or tobacco during pregnancy can increase the risk of the baby developing the condition. Still, there have been no definite conclusions on what is the primary cause.How is Gastroschisis Diagnosed? Gastroschisis develops early in pregnancy, but usually is not detected until the 18-20th week of gestation. The most common way it is diagnosed is through a routine ultrasound. Once the ultrasound produces a picture of the baby inside the womb, the bowels can be seen floating freely in the amniotic fluid. This can confirm a diagnosis of gastroschisis, but doctors may want to perform an additional evaluation with other tests, such as an MRI or fetal echocardiogram, to see if the baby is experiencing any other problems. After a mother is diagnosed, it's recommended to have frequent ultrasounds throughout the rest of the pregnancy to monitor the baby's health and how the gastroschisis is progressing.Can I Prevent Gastroschisis? There is no way to prevent gastroschisis from occurring besides staying as healthy as possible and avoiding substances that could potentially harm the baby. It's been suggested that folic acid can help prevent birth defects such as gastroschisis. Most prenatal vitamins already have this included in the formula, but you may want to find a vitamin that contains at least 400 micrograms of folic acid.What Will Happen After Birth With Gastroschisis? As soon as the baby is born, doctors will begin treatment to protect their organs and keep their vitals stable. The first steps in treating gastroschisis after birth often include: - Using a ventilator: A baby might be put on a ventilator machine to help them breathe if they are having troubles breathing on their own. - Using a nasogastric tube: Gastroschisis can result in fluid and air being stuck in the baby's abdomen, and a nasogastric tube will be used to relieve the pressure. The tube is placed inside the baby's nose and then guided down into the stomach where suction is used to remove the fluid. - Having an IV inserted: After being born, a baby with this condition will have trouble processing nutrition on their own and needs an IV to be directly supplied with food and fluids. - Administering antibiotics: Because the bowels are exposed to the environment, it's important that they don't become infected. Antibiotics will be administered through an IV to prevent this from happening. - Protecting the intestines: Immediately after birth, doctors will wrap the intestines in gauze and covered in plastic to protect the intestines and prevent fluid loss. Gastroschisis will need to be treated with surgery to put the organs back into place. A baby cannot survive with their bowels outside the body. The type of surgery, however, will depend on the severity of the condition. Surgery for gastroschisis is categorized as either "primary repair" or "staged repair". Primary repair is used for simple cases of gastroschisis when there is only a small amount of bowel protruding out of the body and there is no damage to the intestines. The surgery for this is relatively simple, doctors will place the bowels back into the baby's belly and repair the opening in the abdomen. This can be performed on the same day or within the next few days after birth. Primary repair is generally not an option for babies with a large amount of bowel outside the body, if the bowel is severely inflamed or damaged, or if there is not enough room in the baby's stomach to hold the intestines. Staged repair is used for complex cases of gastroschisis. This type of repair often requires multiple surgeries to slowly push the organs back into the abdomen and can take up to two weeks to be completed. In this scenario, doctors will provide a plastic pouch called a silo around the bowel and will slowly tighten it each day to gently push the organs back inside. Once the organs are successfully pushed into place, the silo can be removed.What is the Prognosis for Gastroschisis? Babies with gastroschisis tend to be smaller than average and they may develop slower. It can take some time for them to catch up to other babies in terms of developmental milestones. After receiving surgery, a baby will need to stay in the hospital until they have fully recovered. Inpatient care can range from 30-50 days, depending on the severity of the condition. Each case of gastroschisis is unique and a baby can experience a variety of different effects after treatment, but simple cases of gastroschisis usually do not result in long-term complications. Some babies with complex gastroschisis will have problems feeding after surgery. They may require a feeding tube to absorb nutrition correctly and might experience chronic constipation and abdominal pain. As they grow up, they could possibly develop a food allergy or intolerance. It's important to follow up with your doctor after you bring your baby home to make sure they are feeding and healing properly.Sources and Additional Literature
Tiny, nano-sized crystals of salt encoded with data using light from a laser could be the next data storage technology of choice, following research by Australian scientists. The researchers from the University of South Australia and University of Adelaide, in collaboration with the University of New South Wales, have demonstrated a novel and energy-efficient approach to storing data using light. “With the use of data in society increasing dramatically due to the likes of social media, cloud computing and increased smart phone adoption, existing data storage technologies such as hard drive disks and solid-state storage are fast approaching their limits,” says project leader Dr Nick Riesen, a Research Fellow at the University of South Australia. “We have entered an age where new technologies are required to meet the demands of 100s of terabyte (1000 gigabytes) or even petabyte (one million gigabytes) storage. One of the most promising techniques of achieving this is optical data storage.” Dr Riesen and University of Adelaide Ph.D. student Xuanzhao Pan developed technology based on nanocrystals with light-emitting properties that can be efficiently switched on and off in patterns that represent digital information. The researchers used lasers to alter the electronic states, and therefore the fluorescence properties, of the crystals. Their research shows that these fluorescent nanocrystals could represent a promising alternative to traditional magnetic (hard drive disk) and solid-state (solid state drive) data storage or blu-ray discs. They demonstrated rewritable data storage in crystals that are 100s of times smaller than that visible with the human eye. “What makes this technique for storing information using light interesting is that several bits can be stored simultaneously. And, unlike most other optical data storage techniques, the data is rewritable,” says Dr Riesen. This ‘multilevel data storage’ – storing several bits on a single crystal – opens the way for much higher storage densities. The technology also allows for very low-power lasers to be used, increasing its energy efficiency and being more practical for consumer applications. “The low energy requirement also makes this system ideal for optical data storage on integrated electronic circuits,” says Professor Hans Riesen from the University of New South Wales. “These results showcase the benefits of establishing complementary research capabilities and infrastructure at collaborating universities – this has been a deliberate strategy in the photonics domain that is bearing fruit across a number of projects,” says Professor Tanya Monro, DVC-R at the University of South Australia. The technology also has the potential to push forward the boundaries of how much digital data can be stored through the development of 3D data storage. “We think it’s possible to extend this data storage platform to 3D technologies in which the nanocrystals would be embedded into a glass or polymer, making use of the glass-processing capabilities we have at IPAS,” says Professor Heike Ebendorff-Heidepriem, University of Adelaide. “This project shows the far-reaching applications that can be achieved through transdisciplinary research into new materials.” Dr Riesen says: “3D optical data storage could potentially allow for up to petabyte level data storage in small data cubes. To put that in perspective, it is believed that the human brain can store about 2.5 petabytes. This new technology could be a viable solution to the great challenge of overcoming the bottleneck in data storage.” The research is published in the open access journal Optics Express. SOURCE: University of South Australia
No matter what academic or career path awaits your high schooler, reading comprehension skills will serve your student well. Strong reading comprehension is one of the most valuable skills a student can learn. This holds true in basic high school coursework as well as on standardized tests like the SAT and the ACT. Beyond the tests, though, the ability to comprehend what one reads is an essential tool for any career. But competency in reading comprehension is not an inherent trait. Students must actively work at improving their reading skills, a task that can be difficult in a world that offers so many distractions. As an English teacher, I’ve spoken to countless parents who are looking to help their children improve their reading comprehension skills. I’ve found that the following strategies not only aid students in the process, but also provide parents with insight into how to facilitate their children’s development. 1. Remember the importance of location, location, location. When I ask struggling students where they read, they are often confused. Why does that matter? After answering the question, however, they start to realize the importance of location. Reading for school should be completed at a desk, in a room that doesn’t have a TV or computer. Phones and other devices should be stowed elsewhere. Reading comprehension, especially for texts that are more challenging or perhaps less interesting (this can sometimes be the case when reading for school), requires careful attention and structure. Leaving Instagram open will distract, and lying down in bed will slowly lull a struggling student to sleep. 2. Reading comprehension is not the same as memorization. This statement may sound like a contradiction; a large part of reading comprehension is, after all, the ability to recall plot events from a story or specific details from an article. But to assume that memorization is synonymous with comprehension is a mistake. Memorization is a one-way street, but comprehension also includes a mental dialogue between reader and text. In school, teachers often ask students to reflect on a given book, story, or passage as they read it, and to compare it with their own experiences, knowledge, and philosophies. Rote memorization may allow a student to parrot back some details from a passage, but it will not allow for long-term growth or comprehension. 3. Encourage your child to become an active reader. Reading should be done with one hand on the book and the other holding a pen. Students should note details about characters, either in the book itself or in a separate notebook. (While there are a number of note-taking apps and tools available for computers and smartphones, these can be an invitation to distraction for high schoolers.) All of my students are required to compile details from every novel they read on a grid that features four columns: page number, quotation, importance/analysis, and questions. As my students read, they’re asked to pull quotations that they identify as significant to the plot or to a character’s development. The process of annotating a text in this way both requires and enhances close reading skills, which can often fall by the wayside when students are acting as passive readers. I recognize, too, that sometimes students are confused by things they come across in a text; that is why I include a fourth column for questions. This encourages a back-and-forth, and takes students beyond simple absorption and memorization and into engagement. Interrogating the text in this way can be just as important as offering an analysis, and the practice certainly helps students develop deep comprehension. Some colleagues of mine prefer different organizational methods (like the rigidly structured Cornell Notes, or more basic lists of a work’s major plot points). Regardless of the approach, students should be sure to use a consistent method. Noting thoughts on a text not only maintains a reader’s engagement, but also builds a helpful study guide for a midterm exam or paper. 4. Teach your child to love reading. Some students and parents are looking for a quick fix to improve reading comprehension, but the truth is that a solution is not that simple. Reading comprehension is a gradual process, and those students who develop the best skills tend to be those who already love reading. While many younger children simply assume that they’re not “natural readers,” my time in the classroom has taught me that those students often think of themselves this way simply because they have not yet found a book that has spoken to them. Luckily, a wide range of literature outside of the western literary canon is easier than ever for students to explore. Some kids who typically struggle with texts in school often find that they enjoy young adult novels that deal with relevant teen issues like bullying, social pressures, and first love. Others — often more visual learners — prefer graphic novels. While some may dismiss this genre as being juvenile or childish, their assumptions could not be more wrong. Many graphic novels — or even nonfiction graphic works — tell complex stories through excellent writing with the addition of stunning complementary illustrations. A good source for discovering popular or new titles in these (and other genres) is Goodreads, a social media site that allows users to track their own reading, write reviews, and receive suggestions based on their preferences. 5. Read along with your child and discuss the book. As I mentioned above, reading comprehension is not mere simply memorization; it’s one of the most important skills a student can develop in the literature classroom, or, for that matter, in any classroom. The best way to assist in children’s critical-thinking development is to keep up with their reading and discuss books with them. A popular (and relatively easy) way to initiate a conversation like this is by reading a book and then viewing its film adaptation. Asking about the differences between the film a book, as well as the director’s decisions about visual style and casting choices, allows young readers to consider their own opinions and voice them. On a more practical level, it also asks them to recall specifics from the text. Regardless of which book or story you decide to read with your high schooler, be sure to ask open-ended questions that extend far beyond plot summary or minor details. Open conversations can include questions like, “Is this book still relevant in today’s world?” or, “Can you relate to any of the characters?” In this conversation, you may be able to share some historical context about a given work with your kids — and hear their perspectives on what they’re reading. Last year I challenged the parents of my AP students to read our first novel of the year, Aldous Huxley’s “Brave New World,” along with their kids. Months later at parent–teacher conferences, several of them told me that the shared experience of reading the novel opened up conversations about technology, social media, government surveillance, and the role of the individual in society. I was thrilled, but not surprised. Younger readers yearn for opportunities to better understand as well as challenge the world around them; as a parent, you should work to facilitate that process.
In this article, you will learn the basics of enthalpy, as well as how to use enthalpy of formation to calculate enthalpies of reaction and enthalpies of combustion. Topics Covered in Other Articles - Calculating Enthalpy - Bond Enthalpy - The Laws of Thermodynamics - Gibbs Free Energy - Combustion Reaction Chemists and physicists tend to define change in enthalpy as the heat exchange of a system at constant pressure. Enthalpy is an important thermodynamic concept because it informs whether a process is likely to occur, including chemical reactions. Specifically, chemists often use Gibbs free energy to represent the favorability, or spontaneity, of a reaction. Enthalpy has a direct relationship with Gibbs free energy, as indicated by the equation: Since negative changes in Gibbs indicate spontaneous reactions, many “exothermic” reactions, involving negative changes in enthalpy, tend to be spontaneous. The opposite goes for “endothermic” reactions that have positive changes in enthalpy. Due to the importance of enthalpy in thermodynamically describing chemical reactions, chemists have determined many ways of measuring and calculating enthalpy. Enthalpy of Formation One of the most common ways of calculating the enthalpy of a reaction (or “heat of reaction”) involves using what chemists call enthalpies of formation (or “heat of formation”). For context, each molecule has a characteristic enthalpy of formation. This enthalpy essentially represents the sum total energy of each bond in the molecule. Expressed differently, a molecule’s enthalpy of formation is the heat associated with forming it from its most basic components. For example, take the reaction forming hexane (C6H14) from six moles of elemental carbon and seven moles of H2. The heat given off by this reaction, under constant pressure, is equal to the enthalpy of formation of hexane. It’s important to note that the above value for enthalpy of formation only applies under “standard conditions”. Specifically, a temperature of 20 degrees Celsius (or 298.15K) and a pressure of 1 atm. In context, you will often see standard conditions abbreviated to “STP” for “standard temperature and pressure”. If the reaction takes place under nonstandard conditions, the enthalpy of formation would change. All enthalpies that assume standard conditions have a small circle in superscript, similar to the notation for degrees. Importantly, all enthalpies are what chemists call state functions, in that the change in enthalpy between two states is equal to the difference between the states’ enthalpies, regardless of the intermediate steps taken between the two states. Thus, regardless of mechanism between the carbon and hydrogen, an enthalpic change of -199kJ/mol always occurs under standard conditions. For More Help, Watch out Interactive Video Explaining Enthalpy of Formation! Enthalpy of Reaction Using enthalpies of formation, you can calculate the enthalpic change of any chemical reaction at a given temperature. Importantly, there are many ways of calculating an enthalpy of reaction. Some examples include using bond enthalpies or the temperature change to the surroundings. However, if your reaction involves well known reactants under familiar conditions, then the necessary enthalpies of formation exist online. In such cases, with a fairly simple formula, enthalpies of formation most easily yield the reaction enthalpy. To calculate enthalpy of reaction, you need to multiply the enthalpies of formation of each of your reactants by the stoichiometric coefficients of those reactants in the balanced chemical equation. Then, you need to add the multiplied enthalpies of the products and reactants separately. Finally, you subtract the combined enthalpy of the reactants from the products to yield the overall enthalpy of reaction. Interestingly, chemists also use this process of subtracting the combined values of the reactants from the combined values of the products to calculate an overall reaction value for many other state variables, such as entropy of reaction and Gibbs free energy of reaction. Broadly, chemists call this method of calculating change in a state variable Hess’s Law, after Swiss chemist Germain Hess. Many chemistry students memorize the phrase “products minus reactants” to remember the formula associated with Hess’s Law. Let’s look at a worked example. Enthalpy of Reaction Example: Nitrogen Dioxide Decomposition Nitrogen dioxide sometimes decomposes into nitrogen monoxide and diatomic oxygen according to the following chemical reaction: Under standard conditions, nitrogen dioxide and nitrogen monoxide have enthalpies of formation of and , respectively. Because elemental oxygen occurs naturally as diatomic oxygen, O2 has an enthalpy of formation of zero. To calculate the enthalpy of reaction, we need to multiply the enthalpies of formation of both nitrogen dioxide and nitrogen monoxide by 2, because both have a stoichiometric coefficient of 2 in the balanced chemical equation. Then, we take the multiplied enthalpy of nitrogen dioxide (the “products”) and subtract the multiplied enthalpy of nitrogen monoxide (the “reactants”) to get our overall enthalpy of reaction of 114.14 kilojoules per “one mole of reaction”. This positive reaction enthalpy reveals that the decomposition of nitrogen dioxide is endothermic. Importantly, “one mole of reaction” here refers to the decomposition of two moles of nitrogen dioxide. This is because we calculated the reaction enthalpy using a balanced equation which gave nitrogen dioxide a coefficient of 2. If you instead wanted to know the reaction enthalpy of the decomposition of one mole of nitrogen dioxide, you can simply divide the enthalpy we calculated by two, since that would be a “half mole of reaction.” Similarly, if you wanted to do the same for four moles of nitrogen dioxide, or “two moles of reaction,” you would multiply our value by 2. Enthalpy of Combustion Combustion reactions provide one of the most common reaction types for which chemists use Hess’s Law to then calculate enthalpy of reaction from enthalpies of formation. Importantly, the term “enthalpy of combustion” is used for such enthalpies of reaction, specifically concerning the molecule being combusted. For instance, chemists would use the phrase “hexane’s enthalpy of combustion” to describe the standard reaction enthalpy associated with the combustion reaction of hexane. The same rules as enthalpy of reaction apply when calculating enthalpy of combustion, with the added benefit that different combustion reactions often have the same products. For hydrocarbons, the products generally only involve carbon dioxide and water, though the quantities may differ depending on the number of carbons and oxygens in the molecule. Combustion may also produce nitrogen dioxide and hydrogen sulfide if the combusted molecule has nitrogens or sulfurs. Let’s look at another example, this time a combustion reaction. Enthalpy of Combustion Reaction Example: Ethanol Combustion When one molecule of ethanol combusts under standard conditions, the reaction then produces two carbon dioxides and three water molecules according to the following equation: Thus, to yield the enthalpy of the combustion reaction, we then sum the enthalpies of formation of the products, weighted by their stoichiometric coefficients, and subtract the enthalpy of formation of ethanol (). The result is ethanol’s standard enthalpy of combustion of . Enthalpy of Reaction Practice Problems What is the enthalpy of reaction? What is the enthalpy of reaction? What is the enthalpy of combustion of cysteine? Enthalpy of Reaction Practice Problem Solutions
In mathematics, to multiply means to add a number to itself a particular number of times. Multiplication can be viewed as a process of repeated addition. For example, $4 \times 3$ is the same as $3+3+3+3=12$ In this short lesson, we will learn about the multiplier and the multiplicand. What Is Meant by Multiplier? Meaning of Multiplier in Math Look at the 3 groups of 7 cupcakes. Instead of adding seven three times, we can write it as $ 7 \times 3 =21$ This means there are 21 cupcakes in all. Here, 7 is the multiplier and 3 is the multiplicand. Multiplier and multiplicand are parts of a multiplication statement. How To Find a Product Using Multiplier? When we write a multiplication statement in a horizontal way, the leftmost number is the multiplier. When we write a multiplication statement in a vertical way, the number on the top is the multiplier. Look at the grid shown below. All the boxes contained in the grid correspond to the product of multiplier and multiplicand. This is one of the easiest methods used for numbers with smaller quantities. Experiment with the simulation below by using sliders to change multiplier and multiplicand and observe how the product changes. Tom got 3 packs of trading cards and each pack had 5 cards in it. So, how many cards did Tom get in total? Express this as a multiplication statement and state the multiplier and the multiplicand. Number of cards in one pack of trading cards = 5 Number of cards in 3 packs of trading cards = $5 \times 3=15$ So, Tom got 15 cards in all. \|The multiplier and the multiplicand are 5 and 3 respectively.\| A frog has to jump on every third tile without stepping on any number in between. It starts jumping from the number 3 Can you list the tiles that he jumps on? What is the multiplier here? Let us color each 3rd tile as the frog jumps on the track. We observe that the tiles that the frog jumps on are multiples of 3: 3, 6, 9, 12, 15, 18,... \|So, the multiplier is 3\| Here are a few activities for you to practice. Select/type your answer and click the "Check Answer" button to see the result. This mini-lesson targeted the fascinating concept of Multiplier. The math journey around Multiplier starts with what a student already knows, and goes on to creatively crafting a fresh concept in the young minds. Done in a way that is not only relatable and easy to grasp, but will also stay with them forever. Here lies the magic with Cuemath. We hope you enjoyed learning about the meaning of multiplier in math. At Cuemath, our team of math experts is dedicated to making learning fun for our favorite readers, the students! Through an interactive and engaging learning-teaching-learning approach, the teachers explore all angles of a topic. Be it worksheets, online classes, doubt sessions, or any other form of relation, it’s the logical thinking and smart learning approach that we, at Cuemath, believe in. Frequently Asked Questions (FAQs) 1. Why is the multiplier important? The multiplier is important because it is a factor that amplifies the base value of the given quantity. 2. Is a multiplier always greater than 1? No, the multiplier can take the value 1 - Live one on one classroom and doubt clearing - Practice worksheets in and after class for conceptual clarity - Personalized curriculum to keep up with school
DT - Finished helmets Barn Owls put the finishing touches on their bike helmets and carefully cut them into shape. Then they made a strap to go with their helmet and tried their work on! We think they look fantastic! Science - Chocolate rocks! After learning about classifying rocks, Barn Owls moved on to making the 3 different types of rocks (igneous, metamorphic and sedimentary). They had lots of sticky fun making the rocks out of chocolate! Their hands mimicked the heat and pressure which is used to form the rocks. The children have been practising their conversational skills this half term by learning how to ask and answer simple questions such as 'comment tu t'appelles?' (what is your name), 'qual age as-tu?' (how old are you) and 'ca va?' (how are you). Recently they have been focusing on their pronunciation of the French r sound through lots of conversation practise and games. Design and Technology - Making helmets This half term's DT unit focuses on helmets. First the children researched a range of helmets and discussed their purpose - they examined a motorbike helmet and a horse riding helmet and had lots of fun holding them and working out how they were used. Then the children moved on to designing and making their own bike helmet out of papier mache, using their own design criteria to create the helmets. Science investigation - permeability After learning about classifying rocks, Barn Owls moved on to investigating whether some rocks were permeable or not. First we acted out what being permeable meant (having gaps so that water could move through), then we set up our experiment. The children had fun observing whether bubbles came out from the rocks or not. Friday 17th September - Roman Day! To kick start our Roman History topic, we had a day entirely dedicated to Romans. We began the day by making our own Roman mosaics, talking about the idea of the rich and wealthy having these to decorate their homes. We then moved on to making our own Roman shields and talked about the meanings of the symbols and what a 'boss' was used for. Then we finished off the day with a fantastic feast - some of us were slaves, serving the Romans with the best dishes... Barn Owls have been exploring rocks in Science! We talked about what a geologist is, before moving on to classifying them by their characteristics. We found that there were lots of different ways to classify rocks: weight, size, colour, pattern, texture to name a few! Barn Owls then carried out Moh's scratch test to find out which rocks were hard and which were soft. We discussed how chalk is soft and diamond is hard. This term's R.E topic is reconciliation, so we have been thinking about different ways to show the mending of relationships and friendships. We acted out some friends falling out, and then the peacemaker helped the friends to reconcile.
Here's an example of a fun, short-lived strip that I'd never heard of. Yellow bars correspond to the 95% highest posterior density for divergence times of each species. The Quaternary (2.6 Myr ago–present) and the Neogene (23–2.6 Myr ago) periods are shaded in grey and light blue, respectively. Mean stem ages for 25 of the lineages occurred within the Neogene and for two lineages within the Quaternary.Researching how the history and ecology has affected speciation among the 27 lineages of birds has lead to the discovery that the longer length of time a species can inhabit an area, the more likely it will disperse and diverge. Also, the less mobility a species has, the more likely it will diverge as well. 1. Relationships among species are to be interpreted strictly genealogically, as sister-lineages, as clade relations. Empirically, a phylogenetic hypothesis may be determined.More info about Henning HERE. photo. 2. Synapomorphies provide the only evidence for identifying relative recency of common ancestry. Synapomorphies are understood to be the shared-derived (evolved, modified) features of organisms. 3. Maximum conformity to evidence is sought (his auxiliary principle). Choice among competing cladistic propositions (cladograms) is decided on the basis of the greatest amount of evidence, the largest number of synapomorphies explainable as homologues. 4. Whenever possible, taxonomy must be logically consistent with the inferred pattern of historical relationships. The rule of monophyly is to be followed, thereby each clade can have its unique place in the hierarchy of taxonomic names.
Cognitive Behavioural Therapy or CBT is a psychotherapeutic approach used by therapists to help to promote positive change in people by addressing their thought patterns, feelings and behavioural issues. Difficulties with irrational thinking, dysfunctional thoughts and faulty learning are identified and then treated using CBT. Therapy can be conducted with individuals, groups or families and the goals of CBT are to restructure one's thoughts, perceptions and responses which facilitate changes in behaviours. \| The earliest form of CBT was developed by an American Psychologist, Albert Ellis (1913-2007) in 1955, naming his approach Rational Emotive Behavioural Therapy (REBT). Ellis (right) is looked on as 'the grandfather of cognitive behavioural therapies' Ellis credits Alfred Korzybski (who developed the theory of general semantics, which in turn influenced NLP) and his book 'Science and Sanity' for starting him on the path of founding REBT. In the 1960s an American Psychiatrist, Aaron T Beck, (below) developed another CBT approach called 'cognitive therapy' which was originally developed for depression but rapidly became a favourite model to study because of the positive results it achieved. CBT therapists believe that clinical depression is typically associated with negatively biased thinking and irrational thoughts. CBT is now used to provide treatment in all psychiatric disorders and also increases medication compliance, resulting in a better outcome in mental illness. A major aid in CBT is the ABC technique of irrational beliefs, the three steps are: A is the Activating event, the event that leads to a negative thought. B is the Beliefs, the client's belief around the event. C is the Consequence, the dysfunctional behaviour that ensued from the thoughts and feelings originating from the event. An example would be: Susan is upset because she got a low mark in her math's test, the Activating event A is that she failed her test, the Belief, B is that she must have good grades or she is worthless, the Consequence C is that Susan feels depressed. In the above example, the therapist would help Susan identify her irrational beliefs and challenge the negative thoughts based on the evidence from her experience and then reframe it, meaning, to re-interpretate it in a more realistic light. Another very useful aid in CBT is to help a client identify with the ten distorted thinking patterns: 1 All or nothing thinking - seeing things in black or white, if your performance falls short of perfect, you see yourself as a total failure. 2 Overgeneralization - seeing a single negative event as a never ending pattern of defeat. 3 Mental Filter - you pick out a single negative defeat and dwell on it so as your vision of reality becomes darkened. 4 Disqualifying the positive - you dismiss positive experiences by insisting that they 'don't count' maintaining a negative belief. 5 Jumping to conclusions - you make a negative interpretation even though there are no definite facts that convincingly support your conclusion, this includes 'mind reading' and 'fortune telling' or 'assuming. 6 Magnification (Catastrophising) minimization - exaggerating things or minimizing things, this is also called the 'binocular trick'. 7 Emotional reasoning - assuming that your negative emotions reflect the way things really are, 'I feel it, therefore, it must be true'. 8 Should statements - 'shoulds', 'musts' and 'oughts' are offenders. 9 Labeling and mislabeling - instead of describing your error, you attach a negative label to it, ie 'Im a loser'. 10 Personalisation - you see yourself as the cause of some negative external event which in fact you were not responsible for. These are just some of the techniques used in CBT, others are, relaxation tecniques, communication skills training, assertiveness training, social skills training and giving the client homework assignments. Related Articles - Cognitive, Cognitive Behavioural Therapy, Therapy, Therapies, Therapist,
When you think of winegrowing, you might not think of bees as they are not needed in the production of grapes. Grapevines are hermaphrodites, have both male and female reproductive organs, and can self-fertilize (are wind-pollinated). However, bees are essential organisms in vineyards and actually do have an important role in wine production. Why having bees in the vineyard? Plants that grow around grapevines are crucial for a healthy vines environment, and they do need bees to pollinate them. Bees are the primary pollinators of several plants and cover crops planted in the vineyard. Cover crops in vineyards help to regulate the level of nitrogen in the vineyard, increase the organic content of the soil, help improve the water-holding capacity of the soil, eliminate the need for chemicals use, and regulate vines growth. Thus having cover crops in the vineyard and consequently, bees, create a healthier ecosystem for vines that then produce better quality grapes. Having a sustainable ecosystem is the key for any organic and biodynamic winegrower; that’s why several of them have their own beehives near vineyards. A study from South Australia revealed that honey bees are actively removing the calyptra from grapevine flowers during the flowering phase, and with that increases the pollen yield by 70 % compared to collecting pollen from flowers after capfall. There are several benefits of cap removal by honeybees for the development of berries and grape bunches. For example, bees can help reduce the occurrence of millerandage and formation of live green ovaries (mostly known for the Pinot Noir variety) due to the persistence of the calyptra. They can also be used as entomovector* to place Trichoderma koningii – fungi used as biological control agents for control of Botrytis bunch rot in grapevines. *Entomovector – a pollinating insect used as a vector to spread a substance used in the biocontrol of plant pests and diseases. The insect is typically a honey bee, bumblebee, mason bee, or any other variety of insect that spreads pollen among plants. Possible downside of having bees in the vineyard Some might argue that bees can cause damage to berries. So yes, bees drink juice from grape berry when ripe. However, bees don’t bite the grape to get the juice. If ripe grape berries have a crack or puncture wound from birds, other insects, or natural splitting, then the bees will suck the juice out of grapes, otherwise not. Bees can be found in the vineyards during several grapevine growth stages, but mainly during vines and flowering weeds/cover crops bloom periods. During that time, special care is needed when spraying vines with plant protection products to protect the grapes from pests and pathogens. Vineyard spraying and bees protection Plant protection products (PPPs) are used in agriculture production to protect plants and crops from pests, pathogens, and weeds. As they can contain hazardous substances, special caution is required when applying them. So that they do not harm humans, animals, and the environment. Several initiatives and laws were placed to promote the sustainable use of pesticides. Although PPPs are necessary to protect crops, to produce enough food to feed all the people, they can have adverse effects on food production, as they can harm beneficial organisms such as bees. Without bees, there would be no life, as they pollinate many plants and plant crops that are essential for human survival. Based on estimations, bees and other pollinators pollinate about 70% of agricultural crops, especially fruits, vegetables, and nuts. While beekeepers each year reports on average 30% loss of beehives. There are numerous reasons why bees and other pollinators are declining; one of the most threatening for the bees are plant protection products. That’s why it’s essential to think of bees when spraying vineyards. Some practical advice on how to protect bees when spraying vineyards: - try not to spray with PPPs during the flowering period - if it’s necessary to suppress diseases or pests during flowering, spray when the bees are in hives (very early morning or late evening) and with PPPs which are not dangerous to the bees - mow flowering plants inside and around vineyards, before using PPPs that are dangerous to the bees - when spraying prevent PPPs from drifting to surrounding areas - precisely follow PPP’s user manual - establish mutual cooperation with beekeepers So next time you go into the vineyard and spray with pesticides, do think of bees and protect them as they are a vital element for our survival. Namely, a wast majority of the food we eat relies on honey bees and other pollinators. If there is a way to make your vineyard more bees friendly do that, bees are very hardworking, and with their buzz, you will be rewarded several times, also with higher quality grapes. Hogendoorn, K., Anantanawat, K. & Collins, C. Cap removal by honey bees leads to higher pollen rewards from grapevine flowers. Apidologie 47, 671–678 (2016). Why Biodynamic Vineyards Keep Bees by Nick Hines, on VinePair. Pollinators and Pennsylvania Vineyards, by Lee Stivers, at Penn State Extension, Washington County (online) Why are bees important to vineyards, by Fantesca Estate & Winery team Featured Image: from Bee Built team
We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you! Presentation is loading. Please wait. Published byWalter Neal Modified over 6 years ago Chapter 11.4 Volumes of Prisms and Cylinders Vocabulary Volume = the space that a figure occupies. It is measured in cubic units. Cavalieri’s Principle If two space figures have the same height and the same cross-sectional area at every level, then they have the same volume Volume of a Prism The volume of a prism is the product of the area of a base and the height of the prism Example #1 Find the volume of the rectangular prism Example #2 Find the volume of the triangular prism Volume of a Cylinder The volume of a cylinder is the product of the area of the base and the height of the cylinder Example #3 Find the volume of the cylinder Classwork Pgs 627-628 #1-20, 34 Volume of Rectangular and Triangular Prisms Volumes of Rectangular Prisms and Cylinders Lesson 9-9. Volume: Prisms and Cylinders Lesson 10-7 p.538. Volume The volume of a three-dimensional figure is the amount that fills the figure. The volume is given. Sec. 11 – 4 Volumes of Prisms & Cylinders Objectives: 1) To find the volume of a prism. 2) To find the volume of a cylinder. Volumes of Prisms & Cylinders Volumes of Prisms & Cylinders Objectives: 1) To find the volume of a prism. 2) To find the volume of a cylinder. 10.7 Volume of Prisms I can find the volume in rectangular and triangular prisms. 11-4 Volumes of Prisms and Cylinders. Exploring Volume The volume of a solid is the number of cubic units contained in its interior. Volume is measured. Chapter 10 Review Game. Lessons 10-6 Solid Figures 1, 2, 3, 4, 5, Surface Area 1, 2, 3, 4, 5, Finding Volume 1, 2, 3, 4, 5, 10 m² 4 m =5 m( A = 5 m. The same formula (V = Bh) that is used to find the volume of rectangular prisms and cylinders, can also be used to find the volume. Volume of Triangular Prism. Volume of a Triangular Prism Length Volume of a prism = Area x length Area of triangle = ½ x base x height. Volume of Prisms & Cylinders Section Volume The space a figure occupies measured in cubic units (in 3, ft 3, cm 3 ) Objectives Find volumes of prisms. Find volumes of cylinders. Volumes of Prisms and Cylinders Volumes of Prisms Volume is the space that a figure occupies. It is measured in cubic units. How many cubic feet. Volume Prisms and Cylinders Lesson Volume of a solid is the number of cubic units of space contained by the solid. The volume of a right rectangular. Lesson 3-5 Example Example 1 What is the volume of the rectangular prism? 1.The length of the rectangular prism is 6 units. The width of the rectangular. Volume of Rectangular Prisms 11.4 Volumes of Prisms and Cylinders Volumes of Prisms and Surface Area #31. Vocabulary Volume is the number of cubic units needed to fill a space. V = lwh Ex:Volume is expressed in cubic. A sphere is the set of all points that are a given distance from a given point, the center. To calculate volume of a sphere, use the formula in the blue. Rectangular Prisms and Cylinders © 2021 SlidePlayer.com Inc. All rights reserved.
Though there are huge lithium-ion battery installations from the likes of Tesla that can store energy harvested from renewables like wind and solar, they're not exactly cheap. The USC researchers looked to an existing design that stores energy in liquid form. In the so-called redox flow battery, a positive chemical and a negative chemical are stored in separate tanks. The chemicals are pumped in and out of a chamber where they exchange ions across a membrane – flowing one way to charge and the other to discharge. Though such systems have previously used expensive, dangerous and toxic vanadium and bromine dissolved in acid for their electrolytes in the past, we have seen recent designs that replace those with organic or more environment-friendly alternatives. For its design, the USC team used a waste product of the mining industry and an organic material that can be made from carbon-based feedstocks, including carbon dioxide, and is already used in other redox flow batteries.
Chemical Reaction is defined as transforming one chemical substance into another chemical substance. In a chemical reaction, new material is produced with properties utterly different from the original one, resulting in a chemical change. For instance: rusting of iron, curdling of milk, food digestion, breathing, and so on. For example: O2 + 2Mg(s) gives Magnesium Oxide (MgO). MgO is a mineral that is found in the solid state. The magnesium ribbon is cleaned with sandpaper before being burned in the air. This is done to remove the basic magnesium carbonate protective layer from the magnesium ribbon's surface. Gas evolution: The chemical interaction that involves zinc and dilute sulfuric acid is characterized by hydrogen gas evolution. Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g) ZnSO4(aq) + H2(g) Color Change: When citric acid reacts with the purple-colored potassium permanganate, the color of the solution changes from the color purple to no color. A change in orange to green characterizes the chemical interaction involving sulfur dioxide gas and acidified potassium dichromate solution. Change in substance state: The reaction of candle wax combustion is considered a transition from the state of solid to liquid and then a gaseous state. Temperature change: The chemical reaction involving fast lime water and slaked lime is characterized by a temperature change (a temperature rise). A temperature shift is also present in the chemical reaction involving zinc granules and dilute sulfuric acid (a temperature rise). Precipitation: The reaction of sulfuric acid and barium chloride solution results in a white barium sulfate precipitate. Students may learn more about the depth of chemical reactions by downloading the msvgo app. Get the app for free, right now!
1. Total cholesterol in children aged 10-15 is assumed to follow a normal distribution with a mean of 191 and a standard deviation of 22.4. a. What proportion of children 10-15 years of age have total cholesterol between 180 and 190? b. What proportion of children 10-15 years of age would be classified as hyperlipidemic (Assume that hyperlipidemia is defined as a total cholesterol level over 200)? c. What is the 90th percentile of cholesterol? 2. Among coffee drinkers, men drink a mean of 3.2 cups per day with a standard deviation of 0.8 cups. Assume the number of coffee drinks per day follows a normal distribution. a. What proportion drink 2 cups per day or more? b. What proportion drink no more than 4 cups per day? c. If the top 5% of coffee drinkers are considered heavy coffee drinkers, what is the minimum number of cups consumed by a heavy coffee drinker? Hint: Find the 95th percentile. 3. A study is conducted to assess the impact of caffeine consumption, smoking, alcohol consumption and physical activity on cardiovascular disease. Suppose that 40% of participants consume caffeine and smoke. If 8 participants are evaluated, what is the probability that: a. Exactly half of them consume caffeine and smoke? b. At most 6 consume caffeine and smoke? 4. A recent study of cardiovascular risk factors reported that 30% of adults met criteria for hypertension. If 15 adults are assessed, what is the probability that a. Exactly 5 meet the criteria for hypertension? b. None meet the criteria for hypertension? c. Less than or equal to 7 meet the criteria for hypertension? 5. Diastolic blood pressures are assumed to follow a normal distribution with a mean of 85 and a standard deviation of 12. a. What proportion of people have diastolic blood pressure less than 90? b. What proportion have diastolic blood pressures between 80 and 90? c. If someone has a diastolic blood pressure of 100, what percentile is he/she in? Chapter 6. 1. A study is run to estimate the mean total cholesterol level in children 2-6 years of age. A sample of 9 participants is selected and their total cholesterol levels are measured as follows. 185 225 240 196 175 180 194 147 223 Generate a 95% confidence interval for the true mean total cholesterol levels in adults with a history of hypertension. 2. A clinical trial is planned to compare an experimental medication designed to lower blood pressure to a placebo. Before starting the trial, a pilot study is conducted involving 10 participants. The objective of the study is to assess how systolic blood pressure changes over time untreated. Systolic blood pressures are measured at baseline and again 4 weeks later. Compute a 95% confidence interval for the difference in blood pressures over 4 weeks. Delivering a high-quality product at a reasonable price is not enough anymore. That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe. You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.Read more Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.Read more Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.Read more Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.Read more By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.Read more
Presented at 1759 Revisited: The Conquest of Canada in Historical Perspective, 2009 Abstract: The most significant effect of the Conquest of Quebec on the nearby Wendat community of Jeune-Lorette was not felt until the mid-1790s. Before that time, the community continued as it had before. Two key British decisions helped to make this a period of continuity rather than disruption. First, in September 1760, despite the military role the Wendat played in defending Quebec, James Murray ensured that the community would enjoy the same religious and economic protections as their French-Canadian neighbours. The second decision was that despite the international condemnation of the Jesuits during the 1760s and 1770s, Jesuit missionaries in communities like Jeune-Lorette were allowed to remain in their positions. These two key decisions helped to continue pre-conquest community structures despite the political regime change. During the 1790s the changes brought about by the conquest were beginning to be felt. First, the last Jesuit missionary to Jeune-Lorette died and the colonial government took over administration of the Jesuit seigneuries. Second, access to Dartmouth College during the 1770s helped increase the emphasis on European-based education. Third, increased immigration led to decreased resources in the Wendat hunting territory, limiting the community’s ability to be self-sustaining. These three factors had a profound effect on Wendat interactions with each other, the colonial state, and with their French-Canadian neighbours. The changing relationships of the 1790s opened a brief period where the Wendat were able to influence some of the highest levels of British decision making. Between 1790 and 1830, village leaders regularly petitioned either the governor or the Assembly of Lower Canada about their land rights – seeking to reclaim both seigneurial rights given to them in the seventeenth century and their hunting grounds north of Quebec City. In 1824/1825, this situation reached its apex when four Wendat leaders travelled to England to bring these concerns before the king. By the mid-1830s, once aboriginal affairs came under civil rather than military oversight, British and Euro-Canadian interest in the Wendat claims, and the political influence of the community, declined. By focusing on these events, this paper argues that rather than having an immediate effect on the Wendat, the influence of this regime change was a much slower and drawn-out process. The full-weight of the conquest hit the community in the 1790s, sparking the beginning of a campaign for the rights as allies of the British. Although the community was ultimately unsuccessful at having their land claims recognized, this period of the community’s history not only demonstrates the increasingly negative impact of British colonial policies on aboriginal communities in Lower Canada, but also the way that the conquest opened up positive possibilities to resist these changes.
The number e has been called one of the most important numbers in all of mathematics. However, it is important to remember that e is just a number. Calculated to nine decimal places, e = 2.718281828 e can be extended to countless decimal places and no patterns have ever been discovered in its digits. In this sense e, is very similar to pi. Look at these two graphs. The first is the graph of y = e^x and the second is y= e^-x Notice in the first graph, to the left of the y-axis, e^x increase very slowly, it crosses the axis at y = 1, and to the right of the axis, it grows at a faster and faster rate. The second graph is just the opposite. For negative x's, the graph decays in smaller and smaller amounts. It crosses the y-axis at y = 1, and then decays at slower and slower rates. The natural log is the logarithm whose base is e. The two functions, the natural log and the exponential e, are inverses of each other. In other words, saying y = Ln[x] is the same as e^y = x. Look at the plot of y = Ln[x]. The logarithm grows fast at first, then gradually slows. It also crosses the x-axis at 1 and can only be found for x > 0. Therefore, Log = 0, Ln[0 < x < 1] = - number, and the Ln[x < 0] does not exist. In other words, you cannot take the natural log of a negative number. Here are some important properties of exponential and log functions, you may find useful. e^(a + b) = e^a * e^b e^(a - b) = e^a / e^b (e^a)^b = e^(a * b) Log[a * b] = Log[a] + Log[b] Log[a / b] = Log[a] - Log[b] Log[a^b] = b Log[a] The exponential function can be described as, where a and b are constants. The curve that we use to fit data sets is in this form so it is important to understand what happens when a and b are changed. Recall that any number or variable when raised to the 0 power is 1. In this case if b or x is 0 then, e^0 = 1. So at the y-intercept or x = 0, the function becomes y = a * 1 or y = a. Therefore, the constant a is the y-intercept of the curve. The other parameter in our equation is b. If b is very small and greater than 0, the function flattens out. The curve increases at a slower rate then for large b's. On the contrary, for large b's the curve increases quickly. Look at these two plots. The first is for an equation with a large b, and the second is for a small b. Notice the scales of the plots. For, b's less than 0, the same occurs except the plots look like the plot of e^-x from above. 1.)Simplify the following expressions. a.)e^(ln 2 + ln x) 2.)Solve for y. a.)e^(2y) = x^2 b.)ln(y - 1) = x + ln x 3.)Sketch the following curves on the same axes. Identify the domains of each equation in terms of x. a.)y = ln(-x) and y = -ln(x). b.)y = e^(-x) and y = -e^(x). Application of Exponentials 4.)If you invest A dollars at a fixed annual interest rate, r and interest is compounded continuously to your account, the amount of money, Ao, you will have at the end of t years is, Compounded continuously means that the money in your account is continuously being added interest. It can almost be said that the interest is being added every second, day or night. a.)You deposit $621 in an account that pays 10% interest. How much money will you have after 8 years? after 10 years? b.)How long will it take you to double your money if you invest $500 at an interest rate 6%? Go to next section
Tonga's volcano sent tons of water into the stratosphere. That could warm the Earth The violent eruption of Tonga's Hunga Tonga-Hunga Ha'apai volcano injected an unprecedented amount of water directly into the stratosphere — and the vapor will stay there for years, likely affecting the Earth's climate patterns, NASA scientists say. The massive amount of water vapor is roughly 10% of the normal amount of vapor found in the stratosphere, equaling more than 58,000 Olympic-size swimming pools. "We've never seen anything like it," said atmospheric scientist Luis Millán, who works at NASA's Jet Propulsion Laboratory. Millán led a study of the water the volcano sent into the sky; the team's research was published in Geophysical Research Letters. The volcano sent vapor and gases to a record height The Jan. 15 eruption came from a volcano that's more than 12 miles wide, with a caldera sitting roughly 500 feet below sea level. One day earlier, Tongan officials reported the volcano was in a continuous eruption, sending a 3-mile-wide plume of steam and ash into the sky. Then the big blast came, sending ash, gases and vapor as high as 35 miles — a record in the satellite era — into the atmosphere. Drone aircraft and other video from that day show the dramatic scale of the blast, as the volcano launched an incredibly wide plume into the sky. The intense eruption sent a pressure wave circling around the Earth and caused a sonic boom heard as far away as Alaska. The huge amount of water will likely raise temperatures Earlier large volcanic eruptions have affected climate, but they usually cool temperatures, because they send light-scattering aerosols into the stratosphere. Those aerosols act as a sort of massive layer of sunscreen. But since water vapor traps heat, the Tongan eruption could temporarily raise temperatures a bit, the researchers said. It normally takes around 2-3 years for sulfate aerosols from volcanoes to fall out of the stratosphere. But the water from the Jan. 15 eruption could take 5-10 years to fully dissipate. Given that timeframe and the extraordinary amount of water involved, Hunga Tonga-Hunga Ha'apai "may be the first volcanic eruption observed to impact climate not through surface cooling caused by volcanic sulfate aerosols, but rather through surface warming," the researchers said in their paper. NASA says the data for the study came from the Microwave Limb Sounder (MLS) instrument on its Aura satellite, which measures water vapor, ozone, aerosols and gases in Earth's atmosphere. The volcano interrupted the 'heartbeat' of water in the stratosphere The Jan. 15 eruption emphatically disrupted annual water patterns in the stratosphere (which also holds most of the atmosphere's ozone). The normal mechanism by which water rises into the stratosphere is so reliable that researchers refer to it as a sort of tape recorder, marking annual temperature cycles through alternating bands of dry and moist air rising from the tropics. January is normally the middle of the dry period in that seasonal cycle — but then the Tongan volcano erupted in the South Pacific Ocean, suddenly injecting a huge amount of water high in the atmosphere. "By short-circuiting the pathway through the cold point, [Hunga Tonga-Hunga Ha'apai] has disrupted this 'heartbeat' signal" in the planet's normal atmospheric water pattern, the researchers said. They recommend closely monitoring the water from the volcanic eruption, both to predict its impact in the near term and to better understand how future eruptions might affect the planet's climate. Copyright 2022 NPR. To see more, visit https://www.npr.org.
Thursday 19 October 2017 Over one million children are out of school, and many who are attending school do not receive the kind of education that empowers and ignites their passion. Despite extensive initiatives by civil society, and the government initiating the ambitious Right to Education program, there is much groundwork to be made. This will require not only stronger community engagement and dialogue, but also identifying and implementing newer pathways of enabling learning across educational centres. These are designed to be comprehensive, and address every aspect of the student-teacher-community equation. 1. Creating inclusive schools Leading child rights NGO has initiated a training module to bring about inclusive schools, after workshops and consultations education officials, District Institute of Education and Training (DIET), and NGO staff. Based on UNESCO’s ILFE (Inclusive Learner’s Friendly Environment) toolkit, the modules were made available through teacher and community capacity building to make quality elementary education for all children in a non-discriminatory, inclusive manner through: i. Understanding the causes of exclusion, and the need for inclusion in schools Ii. Facilitating workshops, and identifying the traits of an effective facilitator iii. Identifying and understanding resource materials and ideas on Inclusion promotion in schools and classrooms. The NGO has especially focused on creating gender-sensitive classrooms to bring girls to the classroom, aligned to the government’s girl child education and empowerment programme ‘Beti Bachao Beti Padhao’. 2.Use of ICT for imparting learning To bring about ICT-enabled teaching, teachers are taught to create localised digital content to explain difficult concepts into exciting classroom videos. In an initiative supported by Ricoh India, Save the Children is contributing to Information-Communication Technology (ICT)-enabled education in 80 government schools across India. The NGO is working to provide effective enabling learning environment at government schools, to support retention rate of students. The NGO has also received appreciation for contributing to ICT-enabled education in the state’s government schools, located in remote and conflict-ridden regions. 3. Disaster Risk Reduction in schools Education is often and irreversibly disrupted amid natural disaster. Save the Children has worked with the South Delhi Municipal Corporation (SDMC) to initiate task forces to map and identify responses to everyday potential hazards, such as earthquakes, floods exposed electrical wiring, and even slippery stairs. The work focusses on building children’s resilience, via mock drills, Disaster Resource Rooms with the latest Information and Communication Technology (ICT) resources, and a detailed understanding of potential dangers within the school premises and in the vicinity. 4. Supporting education through relevant infrastructure Retaining children in schools involves giving them relevant infrastructure, such as age-appropriate books and reading material, and an adequate teacher-student ratio. Teachers must also be given regular training on teaching and learning materials (TLMs), to improve their methodologies, such as storytelling and the use of creative expression to instill interest. Other necessities for an engaged classroom include library books, sports materials, musical instruments, outdoor teaching, organizing exposure visits of children, project-based learning, and computer labs. Education must be supported through a dialogue with parents and siblings to actively involve them in children's education. Aligned to its commitment to its 'Every Last Child' campaign, Save the Children channelises funding from those donate to NGO to operate in rural and tribal areas, and urban slums of metros to give children access to quality education. Out-of-school children are mapped and brought back to school through conducting enrolment drives with a special focus on girl children. The NGO executes these campaigns in association with government schools and Aanganwadi, and community members. Donate to charity to join this campaign of pan-India education. The NGO organises community events to sensitise families and communities about girl child education.
Plants and their pollinators have classic mutualistic relationships. In return for helping with reproduction, the pollinators are typically lured to the plants with all sorts of "come hither" coloration, scents, and meals. But a paper in last week's edition of Science described an intriguing variation on the communications between plants and pollinators: a case where the plants signal insects that it's time for them to leave. The plants in question, cycads, are interesting enough on their own. Cycads originated in the Permian era, roughly 300 million years ago. They have distinct male and female plants, and both produce large, club-like "flowers." There is, however, a key difference between them: male flowers provide nourishment to insects, which can eat the pollen, but female plants do not. So, from the plant's perspective, the key question is how to convince insects to leave the male flowers and take the pollen elsewhere, preferably to female plants. The answer appears to be a form of chemical warfare. Females produce low and constant levels of a number of chemicals that can attract the pollinating insects. Male flowers produce similar levels of those chemicals for much of the day. But, at midday, when the temperature at the flowers heats up, male flowers start producing much more of these chemicals. They make such high levels, in fact, that insects are repelled from the male flowers—tests in the lab show that high levels can even be lethal to the insects. Given that female chemical output doesn't change, the authors assume that the insects will move on to their flowers, bringing the pollen to its needed destination. As things cool down in the evening, male plants drop back to normal levels of the chemicals, and the cycle can repeat. The authors term this "push-pull" pollination, and suggest it represents an early step in the evolution of flowering plants. They propose that the cycads, which use the same chemical to both repel and attract, represent a transitional step in between earlier, defensive chemicals used by plants and the latter attractive aromas produced by flowering plants. Science, 2007. DOI: 10.1126/science.1145147
A tooth abscess occurs when a tooth fills with pus and other infected material after the center of a tooth becomes infected with bacteria. A tooth abscess occurs as a result of tooth decay or a broken or chipped tooth. When the tooth’s enamel is broken, bacteria can seep into the tooth’s center (sometimes called the “pulp”). After the tooth is infected, pus—which is made up of dead tissue, white blood cells, and bacteria—collects inside the tooth, causing swelling and pain commonly known as a toothache. Without proper attention, the infection can spread from the pulp and out to the bones supporting the teeth Pain is the main symptom of a tooth abscess. Other symptoms may include: - sensitivity to hot or cold - pain when chewing - bitter taste in the mouth - swollen or red gums - bad breath - swollen glands in the neck - swollen upper or lower jaw In a case where the tooth’s root dies, the pain will stop, but the infection could continue to the supporting bones, which can create serious problems. If you cannot see your dentist immediately, you can use over-the-counter pain relievers or warm salt-water rinses to ease the pain and provide temporary relief. Only your dentist can treat a tooth abscess. Your dentist’s main goal will be to save the tooth by draining the abscess and ridding the mouth of infection. Antibiotics may be given to fight the infection, but a root canal may be needed in order to save the tooth. If the tooth cannot be saved and the infection is serious enough, the tooth may need to be removed. If serious enough, you might be hospitalized to prevent the infection from causing more intense problems.
As we've previously written, researchers now know that cities obey some fascinating scaling relationships. The larger they grow in population, the more patents, infrastructure, crime and economic output cities produce, each according to its own exponential equation. When a city doubles in size, for instance, it more than doubles its GDP. Until now, though, the relationship between population and pollution has been less clear. Larger cities must produce way more of it, right? Beijing, with its 20 million people, seems perpetually steeped in the kind of smog that's visible from space. And yet, larger cities are also supposed to have all kinds of energy-efficiency benefits, and 8 million New Yorkers can't possibly drive as much as 8 million people who live just about anywhere else in America. NASA scientists have been studying satellite data from across the globe in an effort to tease out the connect between population and pollution. In a paper recently published in Environmental Science & Technology, they've determined that cities follow a fairly similar scaling principle on the pollution front, too, although the relationship between population and air quality varies depending on where in the world you look. The scientists focused on measures of nitrogen dioxide, or NO2, stuff that's produced from burning fossil fuels and car traffic. It's bad for you, but good for science: NO2 offers a close proxy for air quality. And the researchers were able to model NO2 levels in urban areas around the world (excluding obvious culprits like power plants) using data collected by the Ozone Monitoring Instrument on NASA's Aura satellite. The results suggest, unsurprisingly, that a million people in particularly energy-intensive parts of the world produce more pollution than a million people in a city where personal cars are still uncommon. A European city of that size, for instance, experiences six times as much NO2 as a comparably sized Indian city. And Indian cities, as they grow in size, experience different rates of pollution growth than cities in America, Europe or Asia. As the scientists, led by Lok Lamsal at the Goddard Space Flight Center, conclude: Urban NO2 pollution, like other urban properties, is a power law scaling function of the population size: NO2 concentration increases proportional to population raised to an exponent. The value of the exponent varies by region from 0.36 for India to 0.66 for China, reflecting regional differences in industrial development and per capita emissions. Or, as NASA explains in this slightly more user-friendly diagram: The population growth of Chinese cities, in other words, apparently comes at the greatest cost in the growth of pollution. Top image: NASA Goddard's MODIS Rapid Response Team
- Using PVAAS for a Purpose - Key Concepts - Concept of Growth - Growth Measures and Standard Errors - Growth Standard Methodology - Predictive Methodology - Topics in Value-Added Modeling - Public Reports - Additional Resources - General Help Assessments analyzed with the Predictive methodology are not given in the same subject with the same type of assessment in consecutive grades. This model generates a predicted score for each student. Predicted scores are labeled as Predicted Score because they reflect students' achievement before the current school year or when they entered a grade and subject or Keystone content area. A predicted score is the score the student would make on the selected assessment if the student makes average or typical growth. To generate each student's predicted score we build a robust statistical model of all students who took the selected assessment in the most recent year. The model includes the scores of all students in the reference group, along with their testing histories across years, grades, and subjects. By considering how all other students performed on the assessment in relation to their testing histories, the model calculates a predicted score for each student based on their individual testing history. To ensure precision in the predicted scores, for most subjects, a student must have at least three prior assessment scores. This does not mean three years of scores or three scores in the same subject, but simply three prior scores on state assessments across grades and subjects. There is one exception. To generate a predicted score for fourth-grade science, only two prior scores are required: third-grade math and ELA. Let's consider an example. Zachary is a high-achieving student who has scored well on state assessments for the past few years, especially in math. To predict Zachary's score on the Keystone assessment, we: - Determine the relationships between the testing histories of all students and their exiting achievement on this assessment in the same year. - Use these relationships to determine what the expected score would be for Zachary, given his own personal testing history. Based on Zachary's testing history, a score at the 83rd percentile would be a reasonable expectation for him. In contrast, Adam is a low-achieving student who has struggled in math. His prior scores on state assessments are low. Just as with Zachary, we use the relationships between the testing histories of all students and their exiting achievement on the assessment statewide to determine a predicted score for Adam. Based upon Adam's own personal testing history, a score at the 26th percentile would be a reasonable expectation for him. Once a predicted score has been generated for each student in the group, the predicted scores are averaged. Because this average predicted score is based on the students' prior test scores, it represents the entering achievement in this subject for the group of students. Next, we compare the students' exiting achievement on the assessment to their entering achievement. If a group of students scores what they were predicted to score, on average, we can say that the group made average, or typical, growth. In other words, their growth was similar to the growth of students at the same achievement level across the reference group. This is the definition of meeting the growth standard in the predictive methodology. If a group of students scores significantly higher than predicted, we can conclude that the group made more growth than their peers across the reference group. If a group scores significantly lower than predicted, the group did not grow as much as their peers. The growth measure is a function of the difference between the students' predicted score and their exiting achievement. This value is expressed in scale score points and indicates how much higher or lower the group scored, on average, compared to what they were expected to score given their individual testing histories. For example, a growth measure of 9.3 indicates that, on average, this group of students scored 9.3 scale score points higher than expected.
Chemical reactions underpin the production of pretty much everything in our modern world. But, what is the driving force behind reactions? Why do some reactions occur over geological time scales whilst others are so fast that we need femtosecond-pulsed lasers to study them? Ultimately, what is going on at the atomic level? Discover the answers to such fundamental questions and more on this course in introductory physical chemistry. The course covers the key concepts of three of the principal topics in first-year undergraduate physical chemistry: thermodynamics, kinetics and quantum mechanics. These three topics cover whether or not reactions occur, how fast they go and what is actually going on at the sub-atomic scale.
About This Chapter FTCE Math: Polynomials - Chapter Summary This chapter explores a variety of key subject matter to know dealing with polynomials in math, covering all the pertinent topics you'll want to brush up on before your FTCE Math test, including: - The binomial theorem - Evaluating a polynomial in function notation - Dividing polynomials with long division - How synthetic division is used to divide polynomials - Using quadratic form to factor polynomials - Writing polynomial equations with rational and complex zeros - The factor theorem and remainder theorem - The rational zeros theorem - The fundamental theorem of algebra - Different transformations of polynomial graphs You can easily return to any specific video segments for further review using the video tags. Take the short practice quizzes that follow the lessons to make sure you have a solid grasp of the polynomials subject matter in this chapter. 1. What is the Binomial Theorem? While the F.O.I.L. method can be used to multiply any number of binomials together, doing more than three can quickly become a huge headache. Luckily, we've got the Binomial Theorem and Pascal's Triangle for that! Learn all about it in this lesson. 2. How to Evaluate a Polynomial in Function Notation This lesson will review how to evaluate polynomials in function notation. Along with an analogy to explain the process, examples will be given and worked during the lesson. 3. How to Divide Polynomials with Long Division Arithmetic long division and polynomial long division are very similar. Yes, it's a long process, but once you have the rhythm you will get every problem correct! 4. How to Use Synthetic Division to Divide Polynomials Synthetic division is a 'short-cut' way of dividing a polynomial by a monomial. You still need to know long division, sorry, but this method is way fun when you're dividing by a monomial! 5. Factoring Polynomials Using Quadratic Form: Steps, Rules & Examples Factoring a polynomial of degree 4 or higher can be a difficult task. However, some polynomials of higher degree can be written in quadratic form, and the techniques used to factor quadratic functions can be utilized. 6. Using Rational & Complex Zeros to Write Polynomial Equations In this lesson, you will learn how to write a polynomial function from its given zeros. You will learn how to follow a process that converts zeros into factors and then factors into polynomial functions. 7. Remainder Theorem & Factor Theorem: Definition & Examples In this lesson, you will learn about the remainder theorem and the factor theorem. You will also learn how to use these theorems to find remainders and factors of polynomials. 8. Finding Rational Zeros Using the Rational Zeros Theorem & Synthetic Division After completing this lesson, you will know what the rational zeros theorem says. You will also know how to apply this theorem to find zeros of polynomial functions. 9. Fundamental Theorem of Algebra: Explanation and Example In this lesson, you will learn what the Fundamental Theorem of Algebra says. You will also learn how to apply this theorem in determining solutions of polynomial functions. 10. Understanding Basic Polynomial Graphs This lesson will cover understanding basic polynomial graphs. The lesson focuses on how exponents and leading coefficients alter the behavior of the graphs. 11. Basic Transformations of Polynomial Graphs The basic transformations for a graph are movement up and down, left and right, pinched or stretched graphs, and flipped graphs. This lesson will review how to accomplish each of these transformations. Earning College Credit Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. 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Other chapters within the FTCE Mathematics 6-12 (026): Practice & Study Guide course - About the FTCE Math Test - FTCE Math: Properties of Real Numbers - FTCE Math: Linear Equations - FTCE Math: Linear Inequalities - FTCE Math: Absolute Value Expressions & Equations - FTCE Math: Systems of Linear Equations - FTCE Math: Ratios & Proportions - FTCE Math: Rational Expressions & Equations - FTCE Math: Radical Expressions & Equations - FTCE Math: Complex Numbers - FTCE Math: Quadratics - FTCE Math: Exponential & Logarithmic Equations - FTCE Math: Vector Operations - FTCE Math: Sequences & Series - FTCE Math: Matrix Operations & Determinants - FTCE Math: Functions - FTCE Math: Piecewise Functions - FTCE Math: Area & Perimeter - FTCE Math: Surface Area & Volume - FTCE Math: Foundations of Geometry - FTCE Math: Lines & Angles - FTCE Math: Geometric Construction - FTCE Math: Properties of Triangles - FTCE Math: Similar & Congruent Triangle Proofs - FTCE Math: Right Triangle Proofs - FTCE Math: Quadrilaterals & Polygons - FTCE Math: Circles & Arcs - FTCE Math: Conic Sections - FTCE Math: Coordinate Geometry - FTCE Math: Transformations in Geometry - FTCE Math: Trigonometry - FTCE Math: Overview of Statistics - FTCE Math: Data Analysis & Statistics - FTCE Math: Regression & Correlation - FTCE Math: Graphic Representations of Data - FTCE Math: Sampling in Statistics - FTCE Math: Probability - FTCE Math: Limits - FTCE Math: Rate of Change - FTCE Math: Calculating Derivatives & Derivative Rules - FTCE Math: Graphing Derivatives - FTCE Math: Integration & Integration Techniques - FTCE Math: Integration Applications - FTCE Math: Mathematical Reasoning - FTCE Math: Teaching Strategies & Methods - FTCE Math: Assessing Student Learning - FTCE Math: Manipulatives & Models in the Classroom - FTCE Math: Problem-Solving Strategies - FTCE Mathematics 6-12 Flashcards
Accuracy, Precision, and Topographic Data In this field/lab exercise, geomorphology students collect topographic data about a small landform using three different methods and critically compare their accuracy and precision. Students produce three topographic maps and write a short report describing their results and analysis. - how to use three different tools (methods) to collect quantitative position data about a landscape: a level and tape; a GPS (global positioning system); and a total station. - how to compile these data on a spreadsheet, and then plot them as a topographic map or surface using computer software. - how to evaluate the quality (accuracy and precision) of those data by comparing the two maps to what you know is actually out there. - finally, give an assessment of the benefits and limitations of each method for collecting data. Methods of GeoscienceWe believe that students must understand the sources and limitations of the spatial measurements used in studying Earth's surface. This exercise challenges students to think critically about precision and accuracy of x,y,z data. They are typically stunned to learn that 50 site-level points makes a better map than 500 GPS points. Thus, this exercise addresses misconceptions common among novice geoscientists ("technology always provides the best data" and "more data is always better"). Context for Use Description and Teaching Materials - Student Handout for Geomorphology Exercise: Accuracy, Precision and Topographic Data (Microsoft Word 87kB May7 12) - Grading Rubric for Topo Accuracy Exercise (Microsoft Word 27kB May7 12) Teaching Notes and Tips After division into MAP teams and re-organizing into expert groups, I start the exercise by marching all of the students to the site and ask them to make a sketch of what the topographic lines for this feature should look like. Then they break into expert groups, which is each accompanied by an instructor (GPS) or TA (site level and tape) or tech (Total Station). The sequence typically plays out like this: - after a brief introduction to saving waypoints, the GPS group members each take 200-400 position measurements and are triumphant as the head to the computer lab to download their data. - the site level group breaks into teams and discusses how to use these tools (site level, stadia rod and tape) to locate x,y,z coordinates in a local framework. The TA must check their proposed method to ensure that they are recording sufficient data to reconstruct their positions. They typically can college ~50-60 positions. - the total station group finds set up excruciatingly slow (they are often still setting up when the GPS people are headed back with data). Once set up, they typically collect 25-35 points.
A variety of threats are impacting amphibian species around the world, causing the massive declines documented here. To better understand the leading threats to amphibians, the assessment recorded known threats to each amphibian species using a standardized list (IUCN Threats Classification Scheme) of major threats. A summary of the number of species affected by each threatening process is shown in Figure 11. Habitat loss and degradation are by far the greatest threat to amphibians at present, affecting nearly 4,000 species. The number of species impacted by habitat loss and degradation is almost four times greater than the next most common threat, pollution. Although disease appears to be a relatively less significant threat for amphibians, for those species affected, it can cause sudden and dramatic population declines resulting in very rapid extinction. In comparison, although habitat loss and degradation affect a much greater number of species, the rate at which a species declines is usually much slower, and there are a number of strategies, such as the creation of protected areas, to counter this threat. Information has not been collected during the assessment on the relative importance of one threat compared with another for a particular species. Development of such information in the future is a priority and will enable a more complete analysis of significant threats to amphibians.
Change of gums from a thin, well-adapted, continuous covering around the teeth to a thick swollen red mass, may not only appear unsightly, but also acts as a platform for further destruction of healthy teeth and supporting bone. 1. Most common cause is infection of the “gingiva”, by a thin covering of food and bacteria on the tooth surface called “Plaque”. The bacterial content of this plaque trigger a response from the gingiva, which results in a swelling. The swelling is caused by accumulation of white blood cells and fluids, which in turn counteracts the action of the bacteria. 2. Due to certain normal condition such as pregnancy and puberty, there is swelling of the gingiva seen. This swelling is an abnormal response to the normal bacteria present in the mouth. The abnormal response is a result of hormonal changes or variation seen during the above-mentioned conditions. 3. Certain disease or deficiency condition may also result in swollen gingiva - Vitamin C deficiency. - Tumors or abnormal growth on the gingiva, which may be harmless or, can be cancerous. 4. Certain drugs used by the patient may result in increased size of the gingiva as a side effect. E.g. 1. Phentoin used in epileptic Fits. 2. Nifidipine used for blood pressure. 1. Pain may or may not be present. 2. If the cause is infection then, the initial stage is indicated by the presence of bright red gingiva. - As the infection progresses the color changes from red to bluish red to deep blue. 3. The gingiva becomes soft and spongy; rarely it may become thickened due to formation of scar tissue. 4. Bleeding of the gingiva is another common symptom in the advanced stage. 5. Swelling caused by the drugs is usually very hard and thick. The gingiva will become swollen even after treatment of the swelling. The swelling occurs only when the drug is administered for a certain period of time.
Know how to use "fewer" and "less"? Find out. "ropy lava," 1859, from Hawaiian. A type of lava having a smooth, swirled surface. It is highly fluid and spreads out in shiny sheets. Compare aa. Our Living Language : The islands that make up Hawaii were born and bred from volcanoes that rose up over thousands of years from the sea floor. Volcanoes are such an important part of the Hawaiian landscape and environment that the people who originally settled Hawaii, the Polynesians, worshiped a special volcano goddess, Pele. Not surprisingly, two words have entered English from Hawaiian that are used by scientists in naming different kinds of lava flows. One, pahoehoe, refers to lava with a smooth, shiny, or swirled surface and comes from the Hawaiian verb hoe, "to paddle" (since paddles make swirls in the water). The other, aa, refers to lava having a rough surface and comes from the Hawaiian word meaning "to burn."
Members visit free all year! Join or renew today. Avoid the line!Print your ticketsat home. Your donation makes a World of Difference. The Zoo’s naked mole-rats live in a colony of approximately 30 animals. Typically, there is one queen who is larger than all of the other “workers” and “soldiers”. With the exception of the queen, individuals cannot be readily identified. You can tell the queen from the other mole rats - she's the largest one in the colony and she often has a huge belly, since she spends a large part of her life pregnant. Usually you'll find all of the mole-rats piled up together in one chamber - the nest chamber. Look for their food in another chamber. Also look for the model of a snake attacking a mole-rat in one of the tunnels. The Rare Animal Conservation Center. Naked mole-rats are small rodents that live in large underground colonies in dry areas of East Africa. One of the most unusual of all mammals, they look a little like small, wrinkled, pink sausages, with legs, a tail and very big front teeth. The name naked mole-rat is misleading. Although they may look completely naked at first glance, they do have whiskers on the head, as well as hairs in other spots, including the tail and between the toes. And although they burrow like a mole and look like a hairless rat, they aren't really either one. They are rodents, like rats and unlike moles, but they are more closely related to the porcupines of North and South America and some other American rodent groups than they are to real rats. As if their appearance were not enough, the naked mole rat has many other claims in the contest for "Earth's weirdest mammal." Keep reading to find out more. Naked mole-rats have remarkably long life-spans for their size. They can live to more than 27 years of age in a zoo or laboratory and to at least 17 years in the wild. Scientists are studying this species to try to understand the physiological basis for their long lives, which are much longer than those of other small rodents. This research could tell us more about the aging process in general. Of course, most individual mole-rats don't reach the maximum age. And it appears that the role or "job" an individual has in the colony affects how long he or she will live. In zoos or laboratories, both workers and reproductive individuals have long life-spans. But in the wild, it appears that only the breeding animals are long-lived. Workers in the wild typically live only two or three years. A rodent with a "job"? We'll get to that next. Naked mole-rats live in large underground colonies. The largest colonies may contain 295 animals or more, but a colony might more typically hold 70-80 members. In terms of social behavior, naked mole-rats are among the most fascinating mammals in the entire world. Within each mole-rat colony, there is social structure that is similar to that seen in some insects, like ants and honeybees, with different categories of animals that have different "jobs" in the colony. There is usually just one breeding female, the queen, and only 1-3 males that might breed with her. Most of the other adults in the colony look for food, help to maintain the burrows, or defend the colony against attackers. Most of these "workers" will never reproduce themselves and spend their entire lives helping to raise or protect the offspring of the queen and her mates. There is also some differentiation within the worker group. "Housekeepers" find and transport food, dig new tunnels and repair existing tunnels. "Soldiers", who tend to be the largest of the workers, protect the colony against predators and against other mole-rats, if the group encounters a neighboring colony while tunneling. A mole-rat colony creates a huge underground network of burrows and chambers, which can include more than two miles of tunnels and can cover an area the size of 20 football fields. Mole-rat workers build these incredible networks using only their teeth to dig! Why go to all the effort of these extensive tunnel systems? Naked mole-rats live on tubers and other underground roots and worker tunnel, apparently in a random fashion, to find the food for the colony. If the workers didn't keep digging new tunnels to find food, the entire colony would starve. Within the tunnel system, there are also "rooms" or chambers with particular functions. The nesting chamber is where the entire colony piles together to rest or sleep, and where the babies are born. The colony may move to a new nest chamber to be closer to a new source of food found by the workers. There is also a toilet chamber, a dead-end room where all the animals urinate and defecate, keeping the waste in a small area. When the toilet chamber fills up, the mole-rats dig a new one. Most of the time, the tunnel system of a naked mole-rat colony is sealed, with no hole to the surface. So oxygen levels may be low and carbon dioxide levels high. How do the animals keep from suffocating? Naked mole-rats have a metabolic rate that is less than half that of other rodents, so they need less oxygen to maintain basic functions. And they have a different form of hemoglobin from other animals, which is more efficient at capturing oxygen to carry through the bloodstream, and can therefore keep the body fully supplied even when the level of oxygen in the air is low. In most naked mole-rat colonies, only the dominant female (the "queen") breeds. After a gestation period of 70-80 days, she will give birth to a litter of 5-15 pups. Litters of over 25 have been recorded. The queen typically breeds year-round, and becomes pregnant again soon after the birth of a litter. One female in a laboratory colony produced over 900 pups in a 12-year period. If the queen dies, several females may fight to become the next queen. The new queen will grow longer and thus become bigger than the other members of the colony. It is very unusual for a mammal to grow taller or longer after reaching full adulthood. Imagine a human having a growth spurt at 25! 4-6 inches long, including the tail 1-3 ounces (30-80 grams). The queen is usually the largest and heaviest member of a naked mole-rat colony. In the wild, naked mole-rats eat tubers, roots and bulbs that they find as the burrow underground. In the Zoo, they eat a variety of fresh produce, including potatoes, sweet potatoes and corn, and fortified rodent food. The naked mole-rat is native to three countries in East Africa - Ethiopia, Somalia, and Kenya. To learn more about the conservation efforts at the Philadelphia Zoo, click here. 3400 W GIRARD AVEPHILADELPHIA, PA 19104 COPYRIGHT ©2017PHILADELPHIA ZOOALL RIGHTS RESERVED
Using Insect and Tick Repellents Safely Diseases Transmitted by Arthropods During the summer months, arthropods, including mosquitoes and ticks, are as common as backyard picnics and swimming pools. Unfortunately, they bring with them not only the discomfort of bites, but also the possibility of transmitting human and animal diseases. Two diseases of concern that occur in the United States are West Nile encephalitis, transmitted by mosquitoes, and Lyme disease, transmitted by ticks. West Nile encephalitis was first documented in the Western Hemisphere in August 1999 when an outbreak occurred in the New York City metropolitan area. In 1999, the Centers for Disease Control and Prevention (CDC) confirmed sixty-two human cases of West Nile encephalitis, including seven deaths, although the actual human infection rate was much higher. Infected mosquitoes transmit the West Nile virus. These mosquitoes usually bite and infect wild birds—the primary hosts of the virus—but can also infect horses and other mammals in addition to humans. The West Nile virus has been detected throughout the entire United States. In Pennsylvania, the West Nile virus has been detected every year since 2000. Lyme disease was identified in the United States in 1975 after a mysterious outbreak of arthritis in Lyme, Connecticut. Since then, reports of Lyme disease have increased dramatically, and the disease has become an important public health problem in some areas of the United States. Lyme disease is an infection caused by a member of the corkscrew-shaped bacteria known as spirochetes. In the Northeast, the deer tick, I. scapularis, is most commonly associated with transmitting this disease to humans. In addition to West Nile encephalitis, mosquitoes can also transmit dog heartworm and the eastern equine, western equine, and St. Louis equine encephalitis viruses. Besides Lyme disease, ticks can transmit Rocky Mountain spotted fever, Colorado tick fever, relapsing fever, tick paralysis, tularemia, babesiosis, and erlichiosis. Some of these diseases are present only sporadically, but when they do occur outbreaks can be severe. Avoiding Contact with Mosquitoes and Ticks Mosquitoes and ticks prefer certain types of environments. By avoiding these areas or eliminating these environments from your outdoor living areas, you can reduce your chance of being bitten. Reducing the number of mosquitoes around your home and neighborhood can be done by eliminating standing water, in which mosquitoes breed. Dispose of anything outside that can hold water, such as tin cans, ceramic pots, and used tires. Drill holes in the bottoms of recycling containers left outdoors. Clean clogged roof gutters every year. Turn over plastic swimming/wading pools and wheelbarrows when not in use. Do not allow water to stagnate in birdbaths, ornamental pools, water gardens, and swimming pools or their covers. Alter the landscape of your property to eliminate standing water. Keep in mind that mosquitoes can breed in any puddle of water during warm weather. Ticks thrive in a different type of environment—mainly wooded, brushy, and grassy places—and prefer shaded areas because they are prone to dehydration. Campers, hikers, outdoor workers, and others who frequent these areas are more likely to come into contact with ticks. For homeowners, exposure to ticks is greatest in the woods and garden fringe areas of their properties, but ticks can also be carried by animals into lawns and gardens. You can determine if you have a high tick population by sweeping or dragging your yard’s vegetation with a white cloth attached to a dowel, then inspecting the cloth for ticks. Removing firewood and clearing leaves, brush, and tall grass from around houses and at the edges of gardens can reduce the number of ticks by reducing the number of rodents present. Although we can avoid or try to eliminate environments where insects and ticks live, we cannot totally eliminate our exposure to these pests. However, we can use insect repellents to make ourselves less attractive to insects and ticks. What are Repellents? Repellents are chemicals applied to exposed skin or clothing that can provide some relief and protection from mosquitoes, ticks, and other biting pests. Repellents containing the active ingredient N,N-diethyl-mtoluamide or N,N-diethyl-3-methylbenzamide— both better known as DEET—are effective in repelling mosquitoes, biting flies, chiggers, fleas, and ticks. DEET has been available to the general public since 1957. According to the Environmental Protection Agency (EPA), DEET is used annually by almost 40 percent of Americans and by about 200 million people worldwide. Choosing an Appropriate Concentration of DEET A variety of products containing DEET (e.g., lotions, creams, gels, aerosols, pump sprays, and towelettes) can be purchased in concentrations ranging from 4 to 100 percent. For most adults, products containing 10 to 35 percent DEET will provide adequate protection under most conditions. The American Academy of Pediatrics (AAP) has updated their DEET recommendations for children, citing: “Insect repellents containing DEET with a concentration of 10 percent appear to be as safe as products with a concentration of 30 percent when used according to the directions on the product labels.” Repellent products containing a higher concentration of DEET do not indicate better protection, only that the protection will last longer. These products are more suitable when mosquitoes and other pests are present in large numbers and when conditions lead to rapid loss of repellent from the skin, such as when the temperature and humidity are high, causing significant perspiration. However, people differ in how attractive they are to mosquitoes, so the efficacy of a repellent varies among people. Repellents usually remain effective for one to five hours. The length of time depends on several factors, including the degree to which a person has perspired, the extent to which a person has rubbed his or her skin, and the amount of repellent that has been applied. Nevertheless, it is wise to use the lowest concentration of DEET that you have found to be personally effective. To use a repellent safely, you must use it properly. Read the product’s label and follow all directions. Is DEET Safe? Having been in use for more than forty years, DEET has been well studied and has a remarkable safety record. Nevertheless, concerns have been raised about using DEET as a repellent. Laboratory testing has shown that DEET is absorbed through the skin, but once in the body, it is readily eliminated in the urine, with the highest urinary concentrations occurring several hours after application. However, studies on both animals and people indicate that DEET does not accumulate in the body. Cases of illness caused by DEET have been reported in the medical literature, but in most of these cases, DEET was used inappropriately, excessively, or repeatedly over a long period. Guidelines for Safe Application Follow these guidelines when using insect repellents containing DEET, especially when applying them to children. - Verify that the product has an EPA registration number; its presence on the label means the product was approved for use by the EPA. - Before using any product, read and understand the directions on its label. - Do not spray a repellent in an enclosed area or near food, and do not inhale aerosol formulations. - According to the AAP, DEET should not be used on infants under two months of age. Other guidelines recommend not using DEET until children are two years of age. - Use just enough repellent to lightly cover exposed skin and clothing. Never apply repellents to cuts, wounds, or inflamed and irritated skin. Do not saturate the skin or apply beneath clothing. - To apply a repellent to your face, first dispense or spray it onto your palms and rub your hands together. Then apply a thin layer to the surface of your skin. Do not place repellent in your eyes or mouth. - Do not allow children to apply DEET by themselves. Do not apply a repellent directly to a child’s skin. First apply it to the palms of your own hands and then apply it to the child. Do not apply repellent to children’s hands because they may touch their eyes and mouth, causing irritation. - DEET can damage plastics, synthetic fabrics, leather, and painted or varnished materials. DEET does not damage natural fibers, such as cotton or wool. - After applying a repellent, wipe or wash it from your hands. - A single application of a repellent is sufficient under most conditions. Avoid prolonged or excessive use of DEET. - If a sunscreen product is needed, it should be applied first, followed by a DEET repellent product. The CDC does not recommend using a combination sunscreen/DEET product. - Once indoors, wash all treated skin and clothing with soap and water. Wash treated clothing before wearing it again. - If you suspect that you or your child is reacting negatively to an insect repellent, discontinue its use, wash treated skin, and call the National Poison Center at 1-800- 222-1222. If you must see a doctor, take the repellent with you, as the label will provide the doctor with additional medical information. A very small segment of the population may be sensitive to DEET and/or other insect repellents. For more information about DEET, contact the National Pesticide Information Center at 1-800-858-7378 or visit their Web site or contact your health care provider. CDC Adopts New Repellent Guidance In late April 2005, the Centers for Disease Control and Prevention released new guidance about effective mosquito repellents. This guidance included the addition of two active ingredients, picaridin and oil of lemon eucalyptus, which have been shown to offer long-lasting protection against mosquito bites. DEET continues to be a highly effective repellent option and was also included in the CDC updated guidelines. Picaridin (or KBR 3023) has been used safely and effectively in other parts of the world for some time. Evidence shows that picaridin is often comparable with DEET products of similar concentration. Oil of lemon eucalyptus (or pmenthane 3,8-diol or PMD) is a plant-based mosquito repellent that provided protection similar to low concentrations of DEET in two recent studies. The label for this product specifies that it should not be used on children under three years of age. Are there Other Alternatives? If you do not wish to use DEET, other skin application products are available that can provide protection. Keep in mind that commercially formulated natural products (e.g., essential oils) and additives such as fragrances and preservatives have the potential to cause allergic contact dermatitis in sensitive individuals. Furthermore, non-DEET repellents may not be safer for use on children since they have not been as thoroughly studied as DEET. Avon’s Skin-So-Soft Bath Oil received considerable media attention several years ago when many consumers reported it to be an effective mosquito repellent. However, various laboratory studies have shown that the original Skin-So-Soft formulation provided less than an hour of protection. Avon now sells products that contain citronella oil, an EPA-recognized insect repellent. Avon’s Skin-So-Soft Bug Guard plus IR3535 Insect Repellent Lotion with Sunblock is an effective insect repellent— in one study, this product did as well as the DEET repellents. The active ingredient in this product is ethyl butylacetylaminopropionate and its acid form. Bite Blocker is a plant-based repellent consisting of soybean oil, geranium oil, and coconut oil. The results of several studies indicate that this product provides good protection for at least three hours. Citronella oil is the active ingredient most commonly found in “natural” or “herbal” insect repellents. Citronella can be an effective repellent, but DEET provides longer protection. Plant-derived repellents have not been demonstrated to have the broad and substantial efficacy of DEET; although thousands of plants have been tested as potential sources of insect repellents. A few plants whose essential oils have shown repellent activity against insects include allspice, basil, cajeput, cedar, cinnamon, citronella, eucalyptus, garlic, geranium, lavender, lemongrass, pennyroyal, peppermint, pine, rosemary, soybean, thyme, and verbena. Most of these oils give short-lasting protection, generally less than two hours. Permethrin is a synthetic pyrethroid and is the most effective deterrent for ticks. Permethrin is applied to clothing, not to the skin. Permethrin is a powerful, rapidly acting insecticide that kills ticks and insects that come in contact with treated clothes. It can be effective for two weeks or longer if the clothing is not laundered. Read the product label to use this insecticide safely. Follow these guidelines when using permethrin repellents. 1 - Treat clothing only; do not apply to skin. If you accidentally get the product on your skin, immediately wash with soap and water. - Apply to clothing in a well-ventilated outdoor area protected from wind. - Only spray permethrin repellents on the outer surface of clothing and shoes before you wear them; do not apply to clothing while it is being worn. - Only spray enough product to lightly moisten the outer surface of the fabric, causing a slight color change or darkening; do not saturate clothing. Do not exceed recommended spraying times. Pay special attention while treating socks, trouser cuffs, and shirt cuffs to ensure proper coverage. - Hang treated clothing outdoors and allow them to dry for at least two hours (four hours under humid conditions) before wearing. - Do not treat clothing more than once every two weeks. Launder treated clothing separately from other clothing at least once before retreating. - Keep treated clothes in a separate bag. 1. New York State Department of Health’s fact sheet titled “Health Advisory—Tick and Insect Repellents” (2004). General Pest Prevention Tips - Make sure window and door screens are “bug tight.” - Wear long-sleeved shirts and long pants if you must go outdoors. Mosquito Prevention Tips - Use the proper type of lighting outside—incandescent lights attract mosquitoes, while fluorescent lights neither attract nor repel them. - Mosquitoes are repelled by high winds, so electric fans may provide some relief at outdoor events. - Stay indoors at dawn, dusk, and in the early evening, when mosquitoes are most active. - If you must, fog with pesticides in the evening, when mosquitoes are active. Follow all directions on the label. - Vitamin B and “ultrasonic” devices have not been proven effective in preventing mosquito bites. Tick Prevention Tips - Avoid deer-tick infested areas, especially in May, June, and July. However, adult ticks can become active any time the temperature goes above 28°F and when there is no snow on the ground. - Wear light-colored clothing so that ticks can be spotted more easily. - Tuck pant legs into socks or boots; tuck shirt into pants. - After being outdoors, remove clothing and wash and dry it at a high temperature. - Inspect your body carefully. Remove attached ticks with tweezers, grasping the tick as close to the skin surface as possible and pulling straight back with a slow and steady force; avoid crushing the tick’s body. How to Read an Insect Repellent Label Because so many different insect repellent products are available, you might find it difficult to choose the right one for your needs. However, the product’s label will provide important information about active ingredients, proper handling and application, and first aid. You should always read and understand the label before using any pesticide product. A few sections of the label are described and a fictitious label is illustrated below. The first thing to look for on a product label is an EPA registration number (as indicated by the letter “A”). This number indicates that the product has been approved by the Environmental Protection Agency for use. The product label will list the active ingredients and their concentration (indicated by the letter “B”). For DEET products, the word “DEET” may not be listed; instead, its chemical name, “N,N-diethyl-m-toluamide,” may be listed as the active ingredient. Again, the concentration will help you choose appropriate products for the length of protection that you need. Proper application and directions for use are also listed on the label (indicated by the letter “C”). For insect repellents, you should look to see if the product is to be applied on your skin or just on your clothing, how the product should be applied to children, and if it can be used indoors. Every label will have a precautionary statement, which covers first aid. This section (indicated by the letter “D”) contains any possible hazards of using the product and what you should do if the product would get into your eyes or be swallowed. Emergency telephone numbers may also be listed. The product label provides other important information, such as what pests are repelled and manufacturer contact information. Be sure to read the entire product label since not all labels are organized in the same way. Centers for Disease Control and Prevention. Insect Repellent Use and Safety. Environmental Protection Agency. Mosquito Control. Fradin, Mark S., and John F. Day. “Comparative Efficacy of Insect Repellents against Mosquito Bites.” The New England Journal of Medicine 347 (2002): 13–18. Fradin, Mark S. “Mosquitoes and Mosquito Repellents: A Clinician’s Guide.” Annals of Internal Medicine 128 (1998): 931–40. National Pesticide Information Center. West Nile Virus. (Contact NPIC at 1-800-858-7378). Prepared by Sharon I. Gripp, database administrator/Webmaster; Steven B. Jacobs, senior extension associate in entomology; and Winand K. Hock, professor emeritus of plant pathology. The text was reviewed by David R. Adams, M.D., Pharm.D., assistant professor of dermatology, Penn State Hershey Medical Center. TitleUsing Insect and Tick Repellents Safely This publication is available in alternative media on request.
A nuts-and-bolts approach to making, and spelling, words! Start with consonant, vowel, consonant to make a word. Then, turn any piece to make a new word. Kids can progress to making longer words, with each bolt holding up to 4 nuts. Includes 6 bolts, 30 printed nuts (enough for multiple kids), and Activity Guide. Bolts measure 5"L, nuts 2½"L. Grades: K+
Important Facts That You Must Know First! - An atom has electrons [negative charge], protons [positive charge] and neutrons [no charge]. - ONLY electrons [negative charges] move during charging process. - Like charges repel and unlike charges attract. - Electrical conductors are materials in which electric charges can move freely. Examples of electrical conductors are metals and water [our daily normal water and not the pure water]. - Electrical insulators are materials in which electric charges cannot move freely. Examples of electrical insulators are rubber, plastic and glass. - Electric charge CANNOT BE CREATED OR DESTROYED. It is only transferred from one object to another. This is known as charge conservation. - Electric charging is due to the transfer of electrons from one object to another. - Discharging is the process of neutralising a charged object by removing excess charges. This is done by addition or removal of electrons. - An insulator can be discharged by heating it over a flame or using moisture. The heat from the flame creates charged air particles that neutralise the charged object. Water molecules in air can also remove excess charges from an object. - A conductor can be discharged by earthing. Earthing provides a path for excess electrons to flow away from or for electrons to flow to the conductor. - When drawing distribution of charges on a solid conductor, you need to remember that the electrons can move freely in the conductor and thus the like charges will repel one another and stay as far away from each other as possible. Thus, the charges are always at the surface of the charged conductor. - Earth is a very big conductor. It acts as a reservoir of charges. Electrons can flow from the conductor to the Earth and vice versa. - In a conductor, charges will cluster around the sharp edges. (refer to O level P2 Q7 in 2013) - Charge polarization is another method of charging by induction for non-conductor. Rub a balloon against your head and put it near tiny pieces of paper and you will see that the tiny pieces will be attracted to the balloon at first. Take a charged rod to replace a balloon, when the charged rod is brought near an insulator (i.e paper), there are no free electrons that can migrate/move throughout the insulating material. So how? Rearrangement of charges take place within atoms and molecules themselves. Atoms don’t move from their relatively fixed positions, but their centres of charge are moved. One side of the atom or molecule is induced into becoming more negative or positive than the opposite side. The atom is said to be electrically polarized. Simply put, when there is an external charged body come near, the electric field of the charged body distort the electron cloud causing the centres of the negative and positive charge to no longer coincide. Refer to Fig.14.1 below for illustration. - Fig.14.1 [ in (a), the centres are coincide while in (b) they don’t due to the distortion created by the presence of an external charged body] - Electric field inside any conductors is always zero as long as there is no electric charge flowing (no current flowing) in the conductors. Commonly Seen Questions - A polythene strip is rubbed on wool. Explain, in terms of movement of charges, how the wool becomes positively charged. Even if the question never state about movement of charges, you should know that you need to build your argument from that angle. When the polythene strip is rubbed on the wool, the atoms at the surfaces are disturbed by friction. Some of the outer electrons are knocked off from the wool and transferred onto the polythene. The wool now has fewer electrons than protons, this results in the wool becoming net positively charged. Note: The electrons transferred onto the polythene are unable to move freely within the polythene and they remain at the surface where the material has been rubbed. Parts of polythene that were not in contact will remain neutral. - A positively charged rod is brought near (not touching) a tiny piece of an uncharged aluminium foil. The aluminium foil is seen moving towards the rod. Explain this observation. When the positively charged rod is brought above the aluminium foil, the free electrons in aluminium foil is attracted and moved closer to the rod as unlike charges attract. This results in the top part (part closer to the charged rod) of the aluminium foil becoming negatively charged and the bottom part becoming positively charged. Since the strength of electrostatic force decreases with distance, the rod will attract the top part more strongly than it repels the bottom part. Thus, there will be a net/overall attractive force between the rod and the aluminium foil. Note: I hope you know that it is not possible to charge aluminium foil by friction since it is a metal. The separate charges (positive and negative) appear on the aluminium foil is known as induced charges. - A plastic comb is rubbed on a shirt and became positively charged. The comb is then brought near small pieces of paper. The pieces of paper seem to be attracted to the comb. Explain. As the comb is approaching the paper, the positively charged comb polarizes atoms in the small pieces of paper and creates a negatively charged surface nearer to the comb. Since the strength of electrostatic force decreases with distance, the comb will attract the top part of the paper more strongly than it repels the bottom part. Thus, there will be a net attractive force between the comb and the pieces of paper. Note: comb polarizes atoms in the small pieces of paper = the positively charge comb induces negative charges on the top part of the paper. - Initially the sphere on the right is positively charged while the metal rod and the left metal sphere are neutral. State and explain the charges on both spheres and metal rod after they are in contact in arrangement shown below. Upon contact, the free electrons in the left sphere and the metal rod will be attracted by the positively charged sphere (right) and move toward it since unlike charges attract. However, based on the conservation of charge, there are fewer negative charges than positive charges when we look at the two spheres and the rod as a single body. Thus, they will be overall/net positively charged. It means that each of the sphere and the rod are all positively charged. Note: It is difficult to argue from the view point that the left sphere and the rod will have fewer electrons than before which make them net positively charged. However, we can’t be certain of the charge on the right sphere. Although, it does not make sense that the right sphere becomes neutral because then the free electrons will continue to move until there is a balance of charges. This question can be modified to ask you to predict the likely observation in which the rod is seen to be repelled from the sphere (if the electrostatic force of repulsion is stronger than the weight of the metal rod). Other questions are just a different arrangement but the way to explain remains unchanged.
Ice studies / icebergs There are four different types of ice in the Arctic, and fundamental project decisions are based on the types of ice that will be encountered. First-year ice Relatively thin sea ice that exists during the winter months but melts during the summer time. Multi-year ice Relatively thick sea ice that has survived at least one summer's melt. Ice island A massive piece of floating ice that has broken from an ice shelf; it may extend several hundred square miles in area and several hundred feet in depth. Iceberg A large floating mass of ice that has broken away from a glacier. ExxonMobil conducts extensive research to understand the hazards posed by icebergs around our operations and to incorporate that information into the design of our facilities. Using drift and tracking research Icebergs are dynamic features that float in different directions and also up and down in the water. With this information we can more accurately forecast how icebergs will move and drift near our operations. Utilizing 3D modeling Using advanced software platforms, we’ve created the first-of-its-kind 3D iceberg modeling capability. This capability allows us to map the underwater features of an iceberg to ensure the optimal ice load predictions that we use in the design of our drilling structures. Building the knowledge base Our iceberg surveys have been released to the research community. We actively publish our iceberg research for the benefit of the broader scientific community.
Motor neuron diseases (muscle stimulation disorders) are characterized by progressive deterioration of the nerve cells that initiate muscle movement. As a result, the muscles stimulated by these nerves also deteriorate and can no longer function normally. For normal muscle function, muscle tissue and nerve connections between the brain and muscle must be normal. Muscle movement is initiated by nerve cells that are located in the spinal cord and in the front part of the brain (called the motor cortex—see Using the Brain to Move a Muscle). These nerve cells connect with nerves that stimulate muscles to move (called motor nerves). In motor neuron diseases, these nerve cells progressively deteriorate. As a result, muscles weaken, waste away (atrophy), and can become completely paralyzed even though the muscles themselves are not the cause of the problem. Motor neuron diseases have various forms, such as amyotrophic lateral sclerosis (the most common), primary lateral sclerosis, progressive pseudobulbar palsy, progressive muscular atrophy, progressive bulbar palsy, and postpolio syndrome. These disorders are more common among men and usually develop in people who are in their 50s. The cause is usually unknown. About 5 to 7% of people who have a motor neuron disease have a hereditary type and thus have family members who also have the disease. Different parts of the nervous system may be affected first. For example, some forms of motor neuron disease affect the mouth and throat first. Others affect a hand or foot first or affect them most severely. Long-lasting paralysis can lead to permanent shortening of muscles (contractures). Muscle strength is affected, but people do not have pain or any changes in sensation. Depression is common. Amyotrophic lateral sclerosis (Lou Gehrig disease): This progressive form begins with weakness, often in the hands and less frequently in the feet or mouth and throat. Weakness may progress more on one side of the body than on the other and usually proceeds up the arm or leg. Muscles, usually those in the hands and feet, start to waste away (atrophy). Muscle cramps are also common and may occur before the weakness, but no changes in sensation occur. People may lose weight and feel unusually tired. Over time, weakness increases. Muscles twitch (called fasciculations). Muscle tone typically increases, and muscles tend to become stiff and tight, leading to muscle spasms (called spasticity). Movements are stiff and clumsy. In some people, muscle tone decreases, making the limbs seem loose and floppy. Controlling facial expressions may become difficult. Weakening of muscles in the throat may lead to slurred speech and difficulty swallowing (dysphagia). Because swallowing is difficult, people sometimes drool and are more likely to choke on liquids. Food or saliva can be inhaled (aspirated) into the lungs, increasing the risk of pneumonia (see Aspiration Pneumonia). The voice usually sounds nasal but may be hoarse. As symptoms progress, people may be unable to control emotional responses and may laugh or cry inappropriately. Eventually, the muscles involved in breathing weaken, leading to breathing problems. Some people need a ventilator to breathe. How rapidly amyotrophic lateral sclerosis progresses varies: Primary lateral sclerosis and progressive pseudobulbar palsy: These forms are rare, slowly progressive variants of amyotrophic lateral sclerosis. Primary lateral sclerosis affects mainly the arms and legs, and progressive pseudobulbar palsy affects mainly the muscles of the face, jaw, and throat. In both disorders, muscles are weak and very stiff and tight (spastic). Muscles twitch (called fasciculations) and waste away. Emotions may be changeable: People with progressive pseudobulbar palsy may switch from happiness to sadness quickly and without reason. Inappropriate emotional outbursts are common. Symptoms usually progress for several years before total disability results. Progressive muscular atrophy: This form can develop at any age. It is similar to amyotrophic lateral sclerosis, but it progresses more slowly, spasticity does not occur, and muscle weakness is less severe. Involuntary contractions or twitching of muscle fibers may be the earliest symptoms. The hands are usually affected first, followed by the arms, shoulders, and legs. Eventually, the whole body is affected. Many people with this form survive 25 years or longer. Progressive bulbar palsy: In this form, the nerves controlling the muscles of chewing, swallowing, and talking are affected, making these functions increasingly difficult. The voice may have a nasal tone. In some people, emotions are changeable. Because swallowing is difficult, food or saliva is often inhaled into the lungs, causing choking or gagging and increasing the risk of pneumonia. Death, which is often due to pneumonia, usually occurs 1 to 3 years after symptoms appear. Some people who have had polio develop this syndrome decades after they have recovered from polio. Postpolio syndrome is more likely to develop in older people and in people who had a severe initial case of polio. Muscles, usually those that were affected by polio, may become tired, painful, and weak and may waste away. However, in most people who have had polio, such symptoms are not due to postpolio syndrome but to the development of a new disorder, such as diabetes, a ruptured (herniated) disk, or osteoarthritis, or to age-related loss of certain nerve cells in areas where polio had already reduced the number of these nerve cells. Postpolio syndrome is sometimes considered a motor neuron disease but is sometimes considered a separate disorder. Doctors suspect motor neuron disease in adults who have progressive muscle weakness without pain or loss of sensation. Doctors ask people which parts of the body are affected, when symptoms started, which symptoms appeared first, and how the symptoms have changed over time. This information gives them clues about the cause of symptoms. Muscle weakness can have many causes (see Causes). Diagnostic tests, such as the following, are done to help narrow the possibilities: To test for other disorders, doctors may do blood tests to check for infections and metabolic disorders, urine tests to check for heavy metals (such as lead or mercury) if people have been exposed to them, a spinal tap (lumbar puncture) to check for inflammation, and genetic tests to check for hereditary disorders such as hereditary neuropathies. Over time, motor neuron diseases tend to cause symptoms that are so characteristic that the diagnosis is obvious without any testing. Motor neuron diseases have no specific treatment or cure. Care provided by a team of several types of health care practitioners (a multidisciplinary team) helps people cope with progressive disability. Physical therapy helps people maintain muscle strength and keep joints flexible and thus helps prevent contractures. Nurses or other caregivers must feed people with swallowing difficulties carefully to prevent choking. Some people must be fed through a tube inserted through the abdominal wall into the stomach (gastrostomy tube). Certain drugs can help relieve symptoms: In some people with amyotrophic lateral sclerosis, riluzole, a drug that protects nerve cells, can prolong life for a few months. It is taken by mouth. If pain develops as the disease progresses (for example, if pain occurs when a person has to sit in one position too long), opioids and benzodiazepines, which are mild sedatives, may be used. In a few people with progressive bulbar palsy, surgery to improve swallowing helps. Because amyotrophic lateral sclerosis and progressive bulbar palsy are progressive and incurable, people who have one of these diseases are advised to establish advanced directives that specify what kind of care they want at the end of life (see Advance Directives). Last full review/revision December 2014 by Michael Rubin, MDCM
Craniopharyngioma is a rare type of cancer. It is a primary brain tumor which is benign and later may become malignant. It mainly affects children and is occasionally observed in adults. Craniopharyngioma is of great concern since it's a childhood cancer. What is Craniopharyngioma? Craniopharyngioma is a tumor that occurs near the pituitary gland and the hypothalamus region of the brain. It is present in the form of a large cyst or multiple cysts filled with turbid, proteinaceous and yellow colored fluid. Generally, Craniopharyngioma is a localized benign tumor. However, it may become large, malignant and can spread in an anterior, posterior and lateral manner to different regions of the brain. Presence of tumor affects the functions of the brain. Although treatment facilities are available, it is difficult to treat Craniopharyngioma due to the location. Craniopharyngioma occurs in both children of age 5-14 years and in adults of age 65-75 years. Craniopharyngioma found in children is of type Adamatinomatus and is not a solid tumor. While in case of adults, it occurs as a papillary type (solid tumor). Due to the difference in types of tumors, the treatment in both cases varies. Symptoms of Craniopharyngioma Craniopharyngiomas affect functions of the brain and due to their presence there is also an increase in the intracranial pressure. These tumors interfere with the hormone production, growth and vision. The effects are manifested in form of symptoms as: - Morning headache which goes away after vomiting - Changes in the vision (eventually there is vision loss) - Loss of balance or problems while walking - Short stature (symptoms due to growth hormone deficiency) - Hypersomnia (unusual sleepiness) - Increase in thirst (polydipsia) or frequency of urination (polyuria) - Fever and nausea - Loss of hearing. - In 20-40% of the cases the hypothyroidism symptoms are observed in the form of lethargy, weight gain, myxedema, dry skin, fatigue, brittle hair, and cold intolerance. Epidemiology of Craniopharyngioma - Craniopharyngioma has an incidence of 1.8 in one million people. It accounts for 1-3 per cent of intracranial tumors while 13 per cent of suprasellar tumors. - It shows no predilection for race, ethnicity or gender. It occurs at the same frequency in both males and females. - The association of craniopharyngioma has been reported in very limited number of familial cases. No genetic basis has been found till date. - It has a bimodal age distribution pattern. Craniopharyngioma occurs in children of age 5-14 years and in adults older than 65 years. Prognosis of Craniopharyngioma Generally the prognosis of Craniopharyngioma depends on the size, type and location of the tumor in the brain. It is observed that after surgical treatment, the rate of recurrence for both benign and malignant (rare) craniopharyngiomas is very high. Overall, it shows poor prognosis. During diagnosis, the overall 2 year survival rate for a patient is 86% and 5 years survival rate is 80%. This rate varies by age group as good prognosis (5 year survival rate is 99%) has been observed in case of children and patients below 20 years of age. While, in case of the older patients i.e., above 65 years, an overall poor prognosis (38% at 5 years) was observed. Causes & Risk Factors of Craniopharyngioma Like many other cancers, the cause of craniopharyngioma and its risk factors is not known. Pathophysiology of Craniopharyngioma There is still limited knowledge on the genetic basis of this tumor. Although, there is loss of tumor suppressor genes, activation of oncogenes, which takes place in craniopharyngiomas too, however, the specific genetic details still remain elusive. Some research studies have shown that beta-catenin and Want pathway may have a significant role in the pathogenesis of these tumors. The exact mechanisms underlying pathogenesis needs to be elucidated. Complications of Craniopharyngioma - The tumor may recur even after surgical and radiation therapy. - After treatment, most of the problems with hormones and vision do not improve. In some cases, the symptoms become worse. Diagnosis of Craniopharyngioma The diagnosis of Craniopharyngioma involves: - Physical examination and past history - Neurological examination - Visual field examination - Tests to be performed includes: - Histopathological analysis is performed to know the type of craniopharyngioma. Adamatinomatus type shows calicifcation, which is rarely seen in case of Papillary tumors. - Blood tests to determine the levels of hormones. - A CT scan or MRI scan of the brain is done to know the location of the tumor in the brain and to check if the tumor has spread to various parts of the brain or has spread extracranially. - Use of PCR analysis shows that Adamatinomatus type is characterized by CTNNB1 mutations and papillary tumors are characterized by BRAFv600E mutations. Treatment of Craniopharyngioma The treatment for children with craniopharyngioma should be planned by a team of health care providers, preferably an inter-disciplinary team who are experts in treating children with brain tumors. Various types of treatments used for treating craniopharyngioma in children are: - Surgery for Treating Craniopharyngioma: It is the first step and the main type of treatment for craniopharyngioma. Surgery means resection or removal of the tumor mass. The main types of surgeries used are Transsphenoidal surgery and Craniotomy. If there is hydrocephalus (excess of fluid), then a shunt (drainage system) surgery is used. It is also used to drain tumors which are made of fluid-filled cysts. Sometimes the entire tumor can be removed only by surgery and requires no further treatment. - Radiation Therapy for Craniopharyngioma: For small tumors, radiation therapy along with surgery is used. At times due to its location or its size, the tumor cannot be removed by surgery, in which case radiation therapy is applied to kill the remaining tumor cells. While treating small children, the radiation therapy is properly chosen to cause minimum side effects. Some types of radiation surgeries include Stereotactic radio surgery for small craniopharyngiomas. For treatment of solid tumors, Intracavitary Radiation therapy is used where the radioactive substance is injected in the solid tumor mass and fluid filled cysts. Intensity modulated proton therapy is also used. - Treating Craniopharyngioma with Chemotherapy: It involves use of anti-cancer drugs to inhibit or kill the tumor cells. As mentioned in the literature, the current effective treatment strategy for malignant tumors is combination of gross total respective surgery with adjuvant chemo-radiotherapy. Drugs like Paclitaxel and Carboplatin have shown to increase the survival rates. In addition, intracavitary chemotherapy is used that places drugs directly at the tumor site, for example a cyst. It is used to treat cases of tumor recurrence. - Biological Therapy for Treating Craniopharyngioma: It is also called Immunotherapy. It makes use of the immune system's defence products such as Monoclonal antibodies, Interleukins and Interferon to treat cancer. This type of therapy is used in case of recurrent tumors. Craniopharyngioma is a rare cancer and mainly affects children. For good treatment outcomes, it should be treated at a centre with many years of experience in treating the patients. The cause and underlying molecular pathogenesis of this cancer needs to be elucidated to enable better treatment management in the future.
Many students can write simple sentences, and run-on sentences, but they struggle with writing solid complex sentences. This written activity is a fun way to get students to sculpt more complex sentences using relative clauses and transition words. Before ANY of this, my students have learned different transition words, how to use them where to use them relative pronouns, etc. I usually start by drawing a few random doodles on the board. describe what a doodle is. If students guess scribble, I also accept this word as appropriate.Then, I ask what they see in the doodles. Once they see how doodles can be changed into different forms, we are ready to start! Activity: This can be arranged in many ways, but I like to have students sit in circles. \|Step One Doodle on different pieces of paper and\| STEP TWO Each student expands on the picture. I know the picture below vague, but notice how the student turned the doodle into a rabbit! STEP THREE (optional) Have the students write one or two words describing their picture. Again looking at the picture to the below, the student could write something like, "An animal," or, "A rabbit," \|Have a box of transition words and relative prnounouns\| STEP FIVE Pass the paper again. This time students also take (or are given) a piece of paper with a random connecting word. They are told to find a way to make the sentence longer using that word, "The rabbit is tall; however, he is fat." STEP FIVE There are multiple ways to do this. I like having students pass the doodling paper to the right, and their connecting word to the left. The students then needed to add another word to the sentence, "The rabbit, who is furry, is tall; however, he is fat." STEP SIX At this point you can continue having the students pass connecting words to the left and doodles to the right, or you can give out new connecting words. STEP SEVEN Continue step six until students become bored you you have had them make at least four rotations. STEP EIGHT Finally, the last time students don't add to the sentence. Their job is to read through the sentence, which at this point can be quite complex, and make it coherent. STEP NINE Students present the final pictures to the class as well as the final description of the picture. Why it Works Students could get bored by this, but because the pictures are so random almost every time it goes like this: Teacher: OK pass the paper to the next student please. Student 1: What is that? Student 2: What did you draw? Student 3: Oh my god this sentence is ridiculous. They are ALWAYS entertained! This is also a great activity to use with adjectives or any other clauses. Basically, anything where students add onto a basic sentence. If you want students to practice speaking you can have them do this in partners. This activity isn't directly humorous, but I PROMISE you that your students will laugh at some of the doodles created and sentences written. On August 2nd the deadline for submitting your blog to be part of the ELT Blog Carnival on Humor will CLOSE! Don't miss out!
The majority of algae that are intentionally cultivated fall into the category of microalgae (also referred to as phytoplankton, microphytes, or planktonic algae). Macroalgae, commonly known as seaweed, also have many commercial and industrial uses, but due to their size and the specific requirements of the environment in which they need to grow, they do not lend themselves as readily to cultivation (this may change, however, with the advent of newer seaweed cultivators, which are basically algae scrubbers using upflowing air bubbles in small containers). Commercial and industrial algae cultivation has numerous uses, including production of food ingredients such as omega-3 fatty acids or natural food colorants and dyes, food, fertilizer, bioplastics, chemical feedstock (raw material), pharmaceuticals, and algal fuel, and can also be used as a means of pollution control. - 1 Growing, harvesting, and processing algae - 2 Algal culture collections - 3 Uses of algae - 4 See also - 5 References - 6 External links Growing, harvesting, and processing algae \|This section does not cite any sources. (October 2013) (Learn how and when to remove this template message)\| Most growers prefer monocultural production and go to considerable lengths to maintain the purity of their cultures. With mixed cultures, one species comes to dominate over time and if a non-dominant species is believed to have particular value, it is necessary to obtain pure cultures in order to cultivate this species. Individual species cultures are also needed for research purposes. A common method of obtaining pure cultures is serial dilution. Cultivators dilute either a wild sample or a lab sample containing the desired algae with filtered water and introduce small aliquots (measures of this solution) into a large number of small growing containers. Dilution follows a microscopic examination of the source culture that predicts that a few of the growing containers contain a single cell of the desired species. Following a suitable period on a light table, cultivators again use the microscope to identify containers to start larger cultures. Another approach is to use a special medium which excludes other organisms, including invasive algae. For example, Dunaliella is a commonly grown genus of microalgae which flourishes in extremely salty water that few other organisms can tolerate. Alternatively, mixed algae cultures can work well for larval mollusks. First, the cultivator filters the sea water to remove algae which are too large for the larvae to eat. Next, the cultivator adds nutrients and possibly aerates the result. After one or two days in a greenhouse or outdoors, the resulting thin soup of mixed algae is ready for the larvae. An advantage of this method is low maintenance. Water, carbon dioxide, minerals and light are all important factors in cultivation, and different algae have different requirements. The basic reaction for algae growth in water is carbon dioxide + light energy + water = glucose + oxygen + water. This is called autotrophic growth. It is also possible to grow certain types of algae without light, these types of algae consume sugars (such as glucose). This is called heterotrophic growth. The water must be in a temperature range that will support the specific algal species being grown mostly between 25 to 35 degrees C. Light and mixing In a typical algal-cultivation system, such as an open pond, light only penetrates the top 3 to 4 inches (76–102 mm) of the water, though this depends on the algae density. As the algae grow and multiply, the culture becomes so dense that it blocks light from reaching deeper into the water. Direct sunlight is too strong for most algae, which can use only about 1⁄10 the amount of light they receive from direct sunlight; however, exposing an algae culture to direct sunlight (rather than shading it) is often the best course for strong growth, as the algae underneath the surface get more light. To use deeper ponds, growers agitate the water, circulating the algae so that it does not remain on the surface. Paddle wheels can stir the water and compressed air coming from the bottom lifts algae from the lower regions. Agitation also helps prevent over-exposure to the sun. Another means of supplying light is to place the light in the system. Glow plates made from sheets of plastic or glass and placed within the tank offer precise control over light intensity, and distribute it more evenly. They are seldom used, however, due to high cost. Odor and oxygen The odor associated with bogs, swamps, indeed any stagnant waters, can be due to oxygen depletion caused by the decay of deceased algal blooms. Under anoxic conditions, the bacteria inhabiting algae cultures break down the organic material and produce hydrogen sulfide and ammonia which causes the odor. This hypoxia often results in the death of aquatic animals. In a system where algae is intentionally cultivated, maintained, and harvested, neither eutrophication nor hypoxia are likely to occur. Some living algae and bacteria, also produce odorous chemicals, particularly certain (cyanobacteria) (previously classed as blue-green algae) such as Anabaena. The most well-known of these odor-causing chemicals are MIB (2-methylisoborneol) and geosmin. They give a musty or earthy odor that can be quite strong. Eventual death of the cyanobacteria releases additional gas that is trapped in the cells. These chemicals are detectable at very low levels, in the parts per billion range, and are responsible for many "taste and odor" issues in drinking water treatment and distribution. Cyanobacteria can also produce chemical toxins that have been a problem in drinking water. Nutrients such as nitrogen (N), phosphorus (P), and potassium (K) serve as fertilizer for algae, and are generally necessary for growth. Silica and iron, as well as several trace elements, may also be considered important marine nutrients as the lack of one can limit the growth of, or productivity in, a given area. Carbon dioxide is also essential; usually an input of CO2 is required for fast-paced algal growth. These elements must be dissolved into the water, in bio-available forms, for algae to grow. Pond and bioreactor cultivation methods Raceway-type ponds and lakes are open to the elements. Open ponds are highly vulnerable to contamination by other microorganisms, such as other algal species or bacteria. Thus cultivators usually choose closed systems for monocultures. Open systems also do not offer control over temperature and lighting. The growing season is largely dependent on location and, aside from tropical areas, is limited to the warmer months. Open pond systems are cheaper to construct, at the minimum requiring only a trench or pond. Large ponds have the largest production capacities relative to other systems of comparable cost. Also, open pond cultivation can exploit unusual conditions that suit only specific algae. For instance, Dunaliella salina grow in extremely salty water; these unusual media exclude other types of organisms, allowing the growth of pure cultures in open ponds. Open culture can also work if there is a system of harvesting only the desired algae, or if the ponds are frequently re-inoculated before invasive organisms can multiply significantly. The latter approach is frequently employed by Chlorella farmers, as the growth conditions for Chlorella do not exclude competing algae. The former approach can be employed in the case of some chain diatoms since they can be filtered from a stream of water flowing through an outflow pipe. A "pillow case" of a fine mesh cloth is tied over the outflow pipe allowing other algae to escape. The chain diatoms are held in the bag and feed shrimp larvae (in Eastern hatcheries) and inoculate new tanks or ponds. Enclosing a pond with a transparent or translucent barrier effectively turns it into a greenhouse. This solves many of the problems associated with an open system. It allows more species to be grown, it allows the species that are being grown to stay dominant, and it extends the growing season – if heated, the pond can produce year round. Open race way ponds were used for removal of lead using live Spirulina (Arthospira) sp. Algae can also be grown in a photobioreactor (PBR). A PBR is a bioreactor which incorporates a light source. Virtually any translucent container could be called a PBR; however, the term is more commonly used to define a closed system, as opposed to an open tank or pond. Because PBR systems are closed, the cultivator must provide all nutrients, including CO A PBR can operate in "batch mode", which involves restocking the reactor after each harvest, but it is also possible to grow and harvest continuously. Continuous operation requires precise control of all elements to prevent immediate collapse. The grower provides sterilized water, nutrients, air, and carbon dioxide at the correct rates. This allows the reactor to operate for long periods. An advantage is that algae that grows in the "log phase" is generally of higher nutrient content than old "senescent" algae. Algal culture is the culturing of algae in ponds or other resources. Maximum productivity occurs when the "exchange rate" (time to exchange one volume of liquid) is equal to the "doubling time" (in mass or volume) of the algae. Different types of PBRs include: Interrupting the carbon dioxide supply can cause algae to flocculate on its own, which is called "autoflocculation". "Chitosan", a commercial flocculant, more commonly used for water purification, is far more expensive. The powdered shells of crustaceans are processed to acquire chitin, a polysaccharide found in the shells, from which chitosan is derived via de-acetylation. Water that is more brackish, or saline requires larger amounts of flocculant. Flocculation is often too expensive for large operations. Algae oils have a variety of commercial and industrial uses, and are extracted through a variety of methods. Estimates of the cost to extract oil from microalgae vary, but are likely to be around three times higher than that of extracting palm oil. In the first step of extraction, the oil must be separated from the rest of the algae. The simplest method is mechanical crushing. When algae is dried it retains its oil content, which then can be "pressed" out with an oil press. Different strains of algae warrant different methods of oil pressing, including the use of screw, expeller and piston. Many commercial manufacturers of vegetable oil use a combination of mechanical pressing and chemical solvents in extracting oil. This use is often also adopted for algal oil extraction. Osmotic shock is a sudden reduction in osmotic pressure, this can cause cells in a solution to rupture. Osmotic shock is sometimes used to release cellular components, such as oil. Ultrasonic extraction, a branch of sonochemistry, can greatly accelerate extraction processes. Using an ultrasonic reactor, ultrasonic waves are used to create cavitation bubbles in a solvent material. When these bubbles collapse near the cell walls, the resulting shock waves and liquid jets cause those cells walls to break and release their contents into a solvent. Ultrasonication can enhance basic enzymatic extraction. The combination "sonoenzymatic treatment" accelerates extraction and increases yields. Chemical solvents are often used in the extraction of the oils. The downside to using solvents for oil extraction are the dangers involved in working with the chemicals. Care must be taken to avoid exposure to vapors and skin contact, either of which can cause serious health damage. Chemical solvents also present an explosion hazard. Another method of chemical solvent extraction is Soxhlet extraction. In this method, oils from the algae are extracted through repeated washing, or percolation, with an organic solvent such as hexane or petroleum ether, under reflux in a special glassware. The value of this technique is that the solvent is reused for each cycle. Enzymatic extraction uses enzymes to degrade the cell walls with water acting as the solvent. This makes fractionation of the oil much easier. The costs of this extraction process are estimated to be much greater than hexane extraction. The enzymatic extraction can be supported by ultrasonication. The combination "sonoenzymatic treatment" causes faster extraction and higher oil yields. Supercritical CO2 can also be used as a solvent. In this method, CO2 is liquefied under pressure and heated to the point that it becomes supercritical (having properties of both a liquid and a gas), allowing it to act as a solvent. Algal culture collections Specific algal strains can be acquired from algal culture collections, with over 500 culture collections registered with the World Federation for Culture Collections. Uses of algae Several species of algae are raised for food. - Purple laver (Porphyra) is perhaps the most widely domesticated marine algae. In Asia it is used in nori (Japan) and gim (Korea). In Wales, it is used in laverbread, a traditional food, and in Ireland it is collected and made into a jelly by stewing or boiling. Preparation also can involve frying or heating the fronds with a little water and beating with a fork to produce a pinkish jelly. Harvesting also occurs along the west coast of North America, and in Hawaii and New Zealand. - Dulse (Palmaria palmata) is a red species sold in Ireland and Atlantic Canada. It is eaten raw, fresh, dried, or cooked like spinach. - Spirulina (Arthrospira platensis) is a blue-green microalgae with a long history as a food source in East Africa and pre-colonial Mexico. Spirulina is high in protein and other nutrients, finding use as a food supplement and for malnutrition. Spirulina thrives in open systems and commercial growers have found it well-suited to cultivation. One of the largest production sites is Lake Texcoco in central Mexico. The plants produce a variety of nutrients and high amounts of protein. Spirulina is often used commercially as a nutritional supplement. - Chlorella, another popular microalgae, has similar nutrition to spirulina. Chlorella is very popular in Japan. It is also used as a nutritional supplement with possible effects on metabolic rate. Some allege that Chlorella can reduce mercury levels in humans (supposedly by chelation of the mercury to the cell wall of the organism). - Irish moss (Chondrus crispus), often confused with Mastocarpus stellatus, is the source of carrageenan, which is used as a stiffening agent in instant puddings, sauces, and dairy products such as ice cream. Irish moss is also used by beer brewers as a fining agent. - Sea lettuce (Ulva lactuca), is used in Scotland where it is added to soups and salads. Dabberlocks or badderlocks (Alaria esculenta) is eaten either fresh or cooked in Greenland, Iceland, Scotland and Ireland. - Aphanizomenon flos-aquae is a cyanobacteria similar to spirulina, which is used as a nutritional supplement. - Extracts and oils from algae are also used as additives in various food products. The plants also produce Omega-3 and Omega-6 fatty acids, which are commonly found in fish oils, and which have been shown to have positive health benefits. - Sargassum species are an important group of seaweeds. These algae have many phlorotannins. - Cochayuyo (Durvillaea Antarctica) is eaten in salads and ceviche in Peru and Chile. Fertilizer and agar With concern over global warming, new methods for the thorough and efficient capture of CO2 are being sought out. The carbon dioxide that a carbon-fuel burning plant produces can feed into open or closed algae systems, fixing the CO2 and accelerating algae growth. Untreated sewage can supply additional nutrients, thus turning two pollutants into valuable commodities. Algae cultivation is under study for uranium/plutonium sequestration and purifying fertilizer runoff. Business, academia and governments are exploring the possibility of using algae to make gasoline, diesel and other fuels. Algae itself may be used as a biofuel, and additionally be used to create hydrogen. See Algae fuel. Chlorella, particularly a transgenic strain which carries an extra mercury reductase gene, has been studied as an agent for environmental remediation due to its ability to reduce Hg2+ to the less toxic elemental mercury. Cultivated algae serve many other purposes, including cosmetics, animal feed, bioplastic production, dyes and colorant production, chemical feedstock production, and pharmaceutical ingredients. - Biology Resources - "A Guide to Geosmin and MIB-producing Cyanobacteria in the United States", Izaguirre and Taylor, Water Science Technology 2004, 49(9):19-24 - Siva Kiran RR, Madhu GM*, Satyanarayana SV, Kalpana P, Bindiya P, Subba Rangaiah G. "Equilibrium and kinetic studies of lead biosorption by three Spirulina (Arthrospira) species in open raceway ponds." Journal of Biochemical Technology Vol. 6, no. 1 (2015): 894-909. - D. Bilanovic; A. Sukenik; G. Shelef (1988). "Flocculation of microalgae with cationic polymers. Effects of medium salinity" (PDF). Elsevier Science Publishers Ltd, England. Retrieved 2006-08-28. - Gilbert V. Levin; John R. Clendenning; Ahron Gibor; Frederick D. Bogar (1961). "Harvesting of Algae by Froth Flotation". Research Resources, Inc, Washington, D.C. Retrieved 2006-08-28. - Rouke Bosma; Wim A. van Spronsen; Johannes Tramper; René H. Wijffels (2003). "ULTRASOUND A new technique to harvest microalgae?". Journal of Applied Phycology. Wageningen UR. 15 (2-3): 143–153. Retrieved 2006-08-28. - "Microalgae separator apparatus and method, United States Patent 6524486". United States Patent Department. Retrieved 2006-08-28. - "Ultrasound, a new separation technique to harvest microalgae - Springer". Springerlink.com. 2003-03-01. Retrieved 2013-08-29. - Chisti, Y. (2007). "Biodiesel from microalgae". Biotechnology Advances. 25 (3): 294–306. doi:10.1016/j.biotechadv.2007.02.001. PMID 17350212. - "Sonochemistry". Prince Edwards Island Government Food Technology Centre. Retrieved 2006-08-28. - "Ultrasonically assisted enzymatic extraction". hielscher.com. Archived from the original on 9 November 2007. Retrieved 2007-11-06. - "Essential Fatty Acids and Herb FAQ's: What are the hazards of Hexane?". Health From The Sun. Retrieved 2006-08-28. - "Automatic soxhlet extraction". cyberlipid.org. Archived from the original on 27 September 2006. Retrieved 2006-08-28. - "Aqueous Enzymatic Extraction of Oil from Rapeseeds". Institute for Applied Environmental Economics. Retrieved 2006-08-28. - "How Do Supercritical Fluids Work?". Supercritical Fluid Technologies. Retrieved 2006-08-28. - "Nutraceuticals and Supercritical Fluid Applications: Production of Astaxanthin Concentrate". Phasex. Archived from the original on 27 August 2006. Retrieved 2006-08-28. - "Home Pages of Culture Collections in the World". 10 December 2009. Archived from the original on 21 November 2009. Retrieved 10 December 2009. - Mumford, T.F. and Miura, A. 4.Porphyra as food: cultivation and economics. in Lembi, C.A. and Waaland, J.R. 1988. Algae and Human Affairs. Cambridge University Press, Cambridge. ISBN 0-521-32115-8 - "The Imp With a Mighty Kick". Asia Week. Retrieved 2006-08-29. - "Aphanizomenon Flos-Aquae Blue Green Algae". Energy For Life Wellness Center. Retrieved 2006-08-29. - "Nutritional value of micro-algae". United States Fisheries Department. Archived from the original on 26 August 2006. Retrieved 2006-08-29. - "Chlorella Growth Factor, nutritional supplement.". - "Treatment Options for Mercury/Metal Toxicity in Autism and Related Developmental Disabilities: Consensus Position Paper" (PDF). - "Sensory properties of strawberry- and vanilla-flavored ice cream supplemented with an algae oil emulsion". Dept. of Food Science, Pennsylvania State University. Retrieved 2006-08-29. - "Transgenic Plants Produce Omega-3 and Omega-6 Fatty Acids" (PDF). School of Biology and Biochemistry, University of Bath, England, UK. Archived (PDF) from the original on 28 August 2006. Retrieved 2006-08-29. - "Seaweeds and their Uses". Methuen & Co. Ltd., London. - Mumford, T.F.; Miura, A (1988). "Porphyra as food: cultivation and economics". In Lembi, C.A. And Waaland, J.R. (Ed.) Algae and Human Affairs: 87–117. - Guiry, M.D.; Blunden, G. (1991). "Seaweed Resources in Europe: Uses and Potential.". John Wiley and Sons Ltd. - McKenna, Phil (7 October 2006). "From smokestack to gas tank". New Scientist. Reed Business Information. 192 (2572): 28–29. doi:10.1016/S0262-4079(06)60667-2. 1233. - Huang C; Chen, MW; Hsieh, JL; Lin, WH; Chen, PC; Chien, LF (2006). "Expression of mercuric reductase from Bacillus megaterium MB1 in eukaryotic microalga Chlorella sp. DT: an approach for mercury phytoremediation". Appl Microbiol Biotechnol. 72 (1): 197–205. doi:10.1007/s00253-005-0250-0. PMID 16547702. - Starckx, Senne (31 October 2012) A place in the sun - Algae is the crop of the future, according to researchers in Geel Flanders Today, Retrieved 8 December 2012 - Algaculture at DMOZ - www.sas.org How to Rear a Plankton Menagerie (home grow micro algae in soda bottles) - io.uwinnipeg.ca breeding algae in batch and continuous flow systems on small scale - Making Algae Grow - www.unu.edu Indian experience with algal ponds - List of companies involved in microalgae production. - Photobioreactors : Scale-up and optimisation PhD thesis Wageningen UR. - Research on algae within Wageningen UR - Photobioreactor using polyethylene and chicken wire. - Instructables.com - Simple Home Algae Culture and Breeding - Microphyt - Microalgae Production and Photobioreactor Design
Generating new stem cell lines is a major focus of many CIRM-funded researchers. Learn why these new lines are considered so important as we accelerate discoveries from the lab bench to the patient’s bedside. What is a stem cell line? A stem cell line is a group of identical stem cells that can be grown and nurtured in a lab dish. A line originates with either a single induced pluripotent stem cell or from the cells of a five-day-old blastocyst—and all resulting cells in the line are replicates of the original cells. Researchers working with these lines can grow large volumes of cells. They can even freeze some in liquid nitrogen for future use or to share with colleagues. We are still learning the best way to grow and maintain stem cells. The cells need nutrients and a recipe of biological factors in the lab dish in order to grow well. Figuring out the best combination of factors to maintain a stem cell line is the focus of several CIRM grants. What are the different ways of creating pluripotent stem cell lines? There are many different approaches to creating new cell lines. CIRM considers this to be such an important endeavor that it has funded $23 million in grants dedicated to the creation of new cell lines and to techniques that make the process more efficient: Option 1: In vitro fertilization All human embryonic stem cell lines in use today were created from embryos generated by vitro fertilization (IVF) and donated by the couple for research purposes. In IVF, researchers mix a man’s sperm and a woman’s eggs together in a lab dish. Some of those eggs will become fertilized. After fertilization, the cells divide for about five days to form a ball of cells called a blastocyst. The blastocyst is essentially a hollow ball of cells containing an inner clump that is known as the inner cell mass. This clump is what give rise to embryonic stem cells if grown in a dish. To generate an embryonic stem cell line, a researcher removes the outer layer of the five-day-old blastocyst then puts the remaining portion on a lab dish containing factors that allow cells of the inner cell mass to grow and thrive. These cells form the basis of a new embryonic stem cell line. Option 2: Nuclear Transfer Another method called stem cell nuclear transfer (SCNT) involves removing the genetic material from an egg, then injecting a different set of genetic material from an adult person’s cell into that egg. Researchers then stimulate the egg to begin maturing. About five days later the egg develops into a blastocyst—the same type of blastocyst that would be used to create cell lines from donated IVF embryos. Researchers remove the inner cell mass from the blastocyst and grow those cells in a lab dish to create a new stem cell line. Researchers have used SCNT to create stem cell lines from a wide range of animals including non-human primates. In 2013, scientists for the first time created human stem cell lines through nuclear transfer. Embryonic stem cells created through SCNT have the advantage of being genetically identical to a person’s own cells, reducing the risk of immune rejection. The process of using nuclear transfer to create cell lines identical to a person’s own cells is sometimes referred to as therapeutic cloning. That’s because those identical stem cells would be created with the intent to derive therapies. Therapeutic cloning should not be confused with reproductive cloning, in which the intent is to create an identical human being. The California constitution, CIRM regulations and all other states that are actively supporting stem cell research expressly prohibit human reproductive cloning. SCNT, an Illustration (Stanford University) Option 3: Induced Pluripotent Stem Cells The first human induced pluripotent stem (iPS) cells were created by inserting four genes into the DNA of human skin cells. Those introduced genes effectively turned back the clock, causing the adult skin cells to revert back to an embryonic-like state, rendering them pluripotent. These cells are an exciting and valuable research tool, however, iPS cells face some hurdles before they can advance towards clinical trials. For example, the earliest versions of the technique used a virus to shuttle the genes into the skin cell, which can integrate into the cell’s DNA and possibly cause hazardous mutations. What’s more, some of the genes used to create the iPS cells have some cancer-causing potential. Many CIRM-funded researchers are working to identify safer ways of creating iPS cells, which would allow researchers to create patient-specific stem cells that can be transplanted as a treatment for disease. These researchers are looking into using methods that don’t require the genes to incorporate into the cell’s DNA or finding a combination of chemicals or proteins to replace those genes as alternative ways of creating iPS cells.
Rabies and How it can be Controlled Man and all mammals are susceptible to rabies, which is almost invariably fatal. The disease is transmitted by an infected animal's biting or licking. The virus enters the victim's body through a break in the skin, or rarely, through mucous membranes (eyes, nose, throat). Rabies affects the central nervous system. It may take from ten days to over a year to develop; however, exposed people can be successfully treated before the development of symptoms by a series of vaccinations. Rabies infection is detected by laboratory examination of the suspect brain tissue. Wildlife rabies is a major source of infection for domestic animals, including pets. The disease may be transmitted to man either by infected wild or domestic animals. Contrary to popular belief, rabies occurs in all seasons and in all sections of the country. watch out for Bold, "friendly", or "apparently tame" wild animals. Night animals, like skunks and foxes, that are seen in the daytime. Pets that have difficulty walking, eating, or drinking. Signs of excitement or viciousness in normally quiet animals. Animals that tear at or scratch an old wound until it bleeds. Cattle that "strain" for long periods. Bats that are unable to fly. In the early stages, the personality of pets may change. A normally friendly dog may stay alone, another may begin to seek more attention. Some animals scratch at the place the virus entered their bodies. Later, symptoms follow a "furious" pattern, a "dumb" (paralytic) pattern, or a combination of both. "Furious" symptoms include excitement, viciousness, roaming, unusual noises, and a tendency to attack anything attracting the animal's attention. Such animals may snap at anything, including themselves. They tend to "drool", and their saliva may be mixed with blood. They may swallow objects such as stones and sticks. These symptoms progress to paralysis and, eventually death. "Dumb" symptoms include difficulty in chewing, swallowing, and drinking, or trouble walking. An animal may not be able to close its mouth. People have been exposed by trying to clear the throats of such animals, which may seem to be choking. Paralysis spreads throughout the body until death. Parts paralyzed by rabies are limp, not rigid or stiff. A veterinarian should be consulted immediately when any of the above signs are first noted. If bitten by an animal, treat the bite as if the animal were rabid, and follow these steps. They may save your life. - Identify the animal - by kind, size, color, and place. Caution children to seek the help of a policeman, school guard or other adult. - Immediately cleanse the wound thoroughly by washing with soap and water. Rinse well and disinfect with alcohol, iodine, or other disinfectants. This lessens the chance of contracting rabies by removing or inactivating virus in the wound. - See a doctor immediately after washing the wound. The physician will decide on need for treatment to prevent rabies. - Report incident to the local health officer and animal control agency. - If possible, have the biting dog or cat tested for rabies or placed under observation. If it is alive and normal after ten days of observation, the animal was not infective for rabies at the time of the bite. THE TEN DAY OBSERVATION PERIOD IS NOT VALID FOR ANIMALS OTHER THAN DOGS, CATS, AND DOMESTIC FERRETS BECAUSE NO INFORMATION IS AVAILABLE AS TO WHEN VIRUS IS EXCRETED IN THE SALIVA OF OTHER ANIMALS. Steps to Community Control of Rabies - Have dogs and cats over four months of age vaccinated by a veterinarian. - Register and license all owned dogs and cats. - Impound all stray dogs and cats. - Appoint an animal control officer and provide pound or shelter facilities. - Euthanize and test all biting dogs and cats or quarantine them for daily observation by a veterinarian for a period of ten days. - Dogs and cats bitten by a known rabid animal should be destroyed immediately. If the owner is unwilling to have this done, the unvaccinated animal should be vaccinated immediately and placed in strict isolation for 90 days, and a "booster" vaccination given in the third and eighth weeks of isolation. If the animal is currently vaccinated, it should be revaccinated immediately and restrained (leashing and confinement) for 45 days. Stock No. 7-15 3/03
Slavery was legal in roughly half of the states up until the Civil War. After the war ended, the Constitution was amended three times to end slavery and ban discrimination against blacks. But discrimination and segregation did not end until the significant Supreme Court cases of the 1950s. Adopted between 1865 and 1870, the Reconstruction Amendments to the Constitution form the legal basis for the protection of civil rights: To supplement the Reconstruction Amendments, Congress passed several civil rights laws in the 1860s and 1870s. These laws gave the president the authority to use the military to enforce civil rights for blacks and made it illegal for states to restrict voting along racial lines. After the federal troops withdrew from the South at the end of Reconstruction in 1877, white southerners quickly took over state governments and openly flouted the recent laws designed to protect the rights of former slaves. Several state governments in the South went so far as to legalize discrimination of blacks; these laws are known as the Jim Crow laws. Even though the Fifteenth Amendment gave all men the right to vote, the southern states employed a variety of tactics to prevent blacks from voting, including the following: Several Supreme Court decisions also weakened the civil rights amendments. In Plessy v. Ferguson (1896), the Court held that the state government could segregate public transportation and thus established the separate but equal doctrine: Blacks could be forced into separate accommodations, including theater seats and hotels, as long as the accommodations were equal to those given to whites.
The abundance of carbon dioxide in the atmosphere is one of the the largest problems in modern society, therefore, creating ways to capture and store Carbon Dioxide is of high importance. An international team of researchers is working on a new technology to transform carbon dioxide into stone. Scientist are already changing CO2 into carbon and plastic but now they’ve found the next solution. This potentially could mean that you can store CO2 below the ground by "transforming" it into stone. The process works by mixing carbon dioxide with hydrogen sulphide or water to create a liquid which can be injected into stone. Hydrogen sulphide is a waste product in the Icelandic geothermal installation of Hellisheidi. At this installation they inject the volcanic basalt rocks with the waste product resulting in chemical reactions binding the carbon dioxide to the rock. Many scientists thought that this transition would take almost a year but it seems to occur in a matter of months. At this moment the geothermal installation has been pumping CO2 out of the ground which is then pressurised and injected back into the rock reacting with minerals within the rock. The mineralisation-process is consistent and safe as there are no leaks out of the ground which makes it a permanent ecological stable storage. Hellisheidi stores 5000 ton CO2 per year, which although is it a large amount there is still a lot of CO2 in the atmosphere which should be dealt with.
\|Linked from this page are documents summarizing the hominid fossil record and hypothesized lines of human evolution from 5 million years ago to the present. Under the current taxonomy (based on genetic rather than behavioral criteria), the term "hominid" refers to members of the biological human family Hominidae: living humans, all human ancestors, the many extinct members of Australopithecus, and our closest primate relatives, the chimpanzee and gorilla. According to The Tree of Life by Guillaume Lecointre and Hervé Le Guyader (Harvard University Press: 2006), the similarly named and easily confused categories of humans and near human apes, in order of increasing inclusiveness, are: Hominini - modern humans and all previous human, australopithecine, paranthropine and ardipithecine ancestors Homininae - all of the above, plus chimpanzees (Panini), our closest living biological kin (a genetic kinship so close that some scientists have suggested their genus name should be changed from Pan to Homo). Hominidae - all of the above, plus gorillas (Gorillinae) Hominoidae - all of the above, plus orangutans (Pongidae) Hominoidea - all of the above, plus gibbons (Hylobatoidae). The chart (at right) shows the evolutionary chronology inputed to these biological branches. Ardipithecus, the common primate ancestor to paranthropines, australopithecines and humans, went extinct about 4 million years ago. Human evolution is a puzzle made up of thousands of fossil pieces. The Chart of Human Evolution (below) shows the major pieces of that puzzle arranged in a likely solution. The tentative connections between species or time of extinction, indicated by a "?", are open to clarification as new DNA and fossil evidence is reviewed in the scientific literature; see comments below the chart. Each colored bar represents the time interval spanned by recovered fossils associated with that species. Dotted lines indicate the conjectural evolutionary lines of descent. (Different paleoanthropologists will connect these in different ways, while preserving the chronological sequence.) Under each species name is a list of the national or geographical areas where all or most of its fossil remains have been found. White numbers inside the species bars indicate the approximate count of distinct individuals in each species from whom fossil remains survived as of c.1995. (Subsequent discoveries and reclassifications will have changed these numbers.) The number of individuals is considerably smaller than the number of fossil specimens, because a specimen can be a single tooth, bone or bone fragment. These numbers suggest the relative reliability of the species classifications they support. The human fossil record from about 2.5 to 1.0 million years ago is especially sparse only about 50 individuals are known, some of them represented by only a single tooth or bone fragment and the evolutionary connections from Australopithecus to Homo erectus, including the evolutionary relationships between habilis, ergaster and erectus, are in dire need of clarification. Time spans for modern humans, Neanderthals and archaic Homo sapiens (H. heidelbergensis) have been extended back beyond accepted fossil limits to accommodate recent genetic evidence that the divergence between the Neanderthal and human lines occurred around 500,000 years ago. As environmental or climate context, the major Ice Age epochs in recent human experience were the Wisconsin, 11,000-35,000 years ago (the most extreme of recent coolings), and the Illinoian, 130,000-190,000 years ago, with an intermediate ice era around 60,000-70,000 years ago. Four human species proposed in the literature H. floresiensis, H. pekinensis, H. georgicus and H. rhodesiensis have been omitted as conjectural or controversial. Homo rudolfensis is now assigned to the "1470 group" variant of Homo habilis, designated by the "1813 group" label. (The numbers refer to the taxonomic type specimens used to anchor the species.) \|Human Variation Across Space & Time\|\|Humans are remarkable for the complexity and pace of their evolutionary history. No other mammal, perhaps no other species, has spread over such a large geographic and ecological range, and evolved so many related species and radically new forms of behavior, within just two million years. There are at least six independent factors contributing to this remarkable evolutionary emergence: genetic variability, climate change, migration, dietary flexibility, alloparenting of extended early development, and technology. Natural selection can only produce new species out of the genetic variation already within existing species. The origins of human variability are genetic in the human genome and this variability is a characteristic fact of human nature. The recent discovery of Australopithecus sediba shows clearly the combinatorial churning of modular components in the early hominid lineage. Evolution was helped along by major cycles of climate change (including changes in African ecological mosaics, sea level, land bridges and temperature), which likely propelled the human prehistory of migration and the resulting geographic isolation of different hominid groups as documented in Hominid Fossil Sites and Patterns of Hominid Dispersal. These migrations were facilitated by an opportunistic, omnivorous dietary range adapted to local food sources. Certainly, the accumulation of hominid technology and culture gave our migrating biological variability an enormously accelerating push primarily through the tendency of culture and in particular language groups to segregate human lineages, but also through a tool culture that allowed increasingly productive exploitation of animal, plant and mineral resources. The prolonged period of infant and child dependence on adults, and the sharing of childrearing tasks among family or group members, ensured robust cultural transmission across generations and at the same time allowed the tool using culture to become rapidly more complex. \|How Many Human Species Are There?\|\| Radiating into separate geographic or ecological domains, ancestral hominids evolved into regional variants that are sometimes described as different species. Genetic variability within hominid species, and uncertainties in fossil reconstruction or geological dating, make some of the species distinctions controversial. In all hominids, males are larger than females, and adults are larger than juveniles, although these sex and age differences vary across species. These distinctive, within species variations in age and sex complicate the problem of distinguishing one species from another on the basis of fragmentary fossil evidence. Academic debates about how to interpret the evidence are sometimes driven by career, partisan or political considerations: researchers have been known to hoard fossils they have discovered to extract the maximum career advantage or ideological leverage. In my view, the reliability of the overall picture of human descent and geographic dispersal should console us for the remaining uncertainties. Indeed, the variety discovered in the fossils, and the diversity of expert judgments as to how the variety in the fossils should be interpreted, together illustrate the physical and cultural divergences that seem characteristic of all human existence, then as now. Fossils document the coexistence of clearly different hominid species over the last 2 million years sometimes in adjacent or overlapping geographic regions. Homo erectus and Homo habilis coexisted in Africa, probably in different ecological niches, for almost 500,000 years. How these different species may have interacted, interbred or contested for resources is unclear. More recently, the disappearance within about 20,000 years of Homo neanderthalensis, as Homo sapiens migrated from the Middle East into Europe, may have been only the uncontested and opportunistic replacement of one species by another, as some climate evidence suggests. Or it may have been the outcome of a protracted racial struggle, as the many historical instances of predatory wars, genocide and slavery make all too plausible. The genetic evidence of interbreeding between the species is consistent with the common practice in ancient Eurasian cultures of the sexual and labor exploitation of the defeated. The possible tensions between coexistence and competition is a key missing piece in the story of human evolution, especially as this relates to species succession within the same geographic area, the rapid pace of human dispersal into new geographic areas, and episodes of interbreeding as lineages met after long separation. \|What Is the Human "Family Tree"?\|\|Evolutionary biologists use a cladogram, the treelike diagram of evolutionary branches or clades, to organize species into lines of evolutionary descent across time. Biologists use three types of evidence to deduce evolutionary connections: genetics, morphology, and geologic dating. (Behavior, normally a key part of evolutionary studies, can only be inferred in extinct species for example, by examining the ecology in which the species flourished and the species adaptations for eating and locomotion.) Analyses of primate fossils and the genetic relatedness of living primates converge to the conclusion that humans and chimpanzees branched from a common ancestor about 7 million years ago. DNA recovered from several uncontaminated Neanderthalensis fossils indicated that modern humans and extinct neanderthals diverged about 400,000 years ago; but more recent studies show that they must have interbred within Europe or the Middle East since then. Genetic samples collected from indigenous populations around the world indicate that the ancestors of the world human population diverged from the indigenous African population about 200,000 years ago. These studies also provide remarkably detailed evidence for subsequent waves of human migration, including a final migration out of Africa around 90,000 years ago by the first humans similar to ourselves. The rest of the puzzle must be deduced from morphology (physical form, as reconstructed from the bones) and geologic dating. "Absolute" fossil dating can be quite reliable for fossils buried within intact rocks, but for fossils found exposed on the surface, or buried within alluvial or eroded deposits, dates can be grossly conjectural. And morphology becomes a subtle interpretation when the available fossils are crushed and incomplete, or collated from different fragmentary fossils found in different geographic locations. The cladogram for human evolution shown above currently lacks key pieces of evidence. For that reason I have omitted several descent connections in the diagram, although the species distinctions and time spans shown in the diagram appear to be adequately documented. Note that there is no dispute whatsoever among biologists that all these different species should be interconnected as a single branching history or "family tree" of hominid descent. The diagram simply indicates that we lack sufficient evidence, at present, to state with confidence where and when those branchings occurred. These are some of the most interesting but currently unanswered questions about human descent: (1) Does Homo ergaster or Homo habilis have chronological priority as the earlier hominid in a single line of descent to modern humans, or (more likely) were these separate and coexisting hominid lines by about 2 million years ago? (2) Is Homo ergaster a distinct species, or an African variant of early Homo erectus? (3) Are the (mostly African) examples of Homo erectus descended from Homo ergaster; or are they either (a) descended from Homo habilis or (b) descended from the same ancestor as Homo habilis? (4) Do the (mostly Asian) fossils of Homo erectus represent a single species that lived for 2 million years or a sequence of species flourishing around 1.6 million, 1.2 million and 200,000 years ago? (5) Is archaic Homo sapiens (Homo antecessor or Homo heidelbergensis) descended directly from Homo ergaster and coexisting with Homo erectus, or is it a branching out of Homo erectus? These questions can only be answered with more complete fossils from the period 2.5 to 1.0 million years ago, which have so far eluded discovery. \|What Is the Fossil Evidence?\|\|Hominid fossil remains are precious. Complete skeletons are extraordinarily rare before recent times. Teeth and lower jaws, and the facial and upper cranial bones of the skull, are the most common fossils to survive from any period. Skulls are almost never found intact but must be reconstructed from fragments. Thigh bones are next most often retrieved, while remains of the feet, hands, pelvis or spine are extremely rare. Specific behavioral conclusions require specific parts of the skeleton. For example, adaptation for a crouching or upright posture can be inferred from the connection of the spine to the skull, but bipedalism (habitual walking on two legs) requires evidence from bones involved in the thigh, knee, or foot joints. An opposable thumb requires evidence from wrist or hand bones. Skulls are used as evidence for the evolution of The Hominid Brain. Endocasts (models of the inside of a skull) offer good evidence for the size and shape of the brain that was in the skull, and brain anatomy is sometimes (tenuously) used to infer the cognitive capabilities of the different species; cognitive abilities can also be inferred from the skills required to make fire and manufacture Hominid Tools. Last revised 10.08.2014 © 2014 Bruce MacEvoy
The environment is everything around us. All our surroundings including the air, soil, water, plants, and animals make up the environment. Plants and animals need a healthy environment to survive. An ecosystem is an area where living organisms interact in a specific way with the local environment to survive. When ecosystems are damaged by man, then some living organisms may not be able to survive. A bio-me is a large group of similar ecosystems like the desert, savanna, and rain forest. Environmental science studies the environment and how the earth works. Environmental scientists often study how humans have impacted the Earth’s environment and how we can reduce the impact that humans have on the environment. Environmental scientists study things like the atmosphere, the oceans, geology, habitats, and ecology. The Earth’s environment is constantly recycling nutrients so they can be used by different parts of the environment. These cycles are important for the existence of living organisms. Some important cycles include the water cycle, the nitrogen cycle, the carbon cycle, the oxygen cycle, and the food chain. Human activities have created many environmental issues from land, water, and air pollution. Part of environmental science is to determine how the environment has been impacted and then to work on ways to help the environment recover. One important aspect of helping the environment to recover is Renewable Energy. Renewable energy uses energy sources that cannot be “used up.” Rather than burning fossil fuels like coal and oil, renewable energy uses energy sources like the wind and the Sun.
Students learn biology, chemistry, and the history of Earth and its water. Teaching to Standards: SCIENCE A systematic science curriculum for middle and high school students Two years of classroom research at the University of North Carolina at Charlotte have shown Teaching to Standards: Science to be highly effective in teaching science vocabulary and engaging students in inquiry-based lessons. Students participate in a hands-on experiments during each lesson and use the Student Response Guide to engage in the inquiry process. The curriculum is designed for students with moderate-to-severe developmental disabilities, including autism. Their own student book, ScienceWork, provides students with extension activities that connect the science concepts to the world around them. Teachers follow scripted lessons that provide clear direction for individual student accommodations. A set of experiment materials included in the Classroom Kit makes it easy to prepare for class. An electronic Image Library can be used to create communication overlays and additional homework assignments. ISBN: 1-57861-664-6Click here to see how this product aligns to state and national standards. Teaching to Standards: SCIENCE is a research-based science curriculum for middle and high school students (ages 12-21) who have moderate-to-severe developmental disabilities including intellectual disabilities and autism. The curriculum objectives align with state and national standards, including those established by the National Science Education Standards. The curriculum includes four units of study which address science standards using an inquiry-based approach: Earth (Earth’s history), Biology (including microbiology), Waters (Earth’s waters), and Chemistry. Lessons are based on the principles of systematic instruction and provide scripts and suggestions for adaptations to accommodate students who are nonverbal, have visual or hearing impairments, or have special physical needs. All students learn actual scientific vocabulary like pollution, precipitation and condensation. Evidence-based practices for teaching science to this population were gleaned from a comprehensive literature review and form the basis for the curriculum. Suggestions for extending skills or for creating more learning opportunities in the everyday lives of the students are provided as stories in the ScienceWork book. The program can be used as a full-year curriculum or as a model for selecting content that matches specific state standards. What you get: Teaching to Standards: SCIENCE Teaching to Standards: SCIENCE How it works: Teaching to Standards: SCIENCE is highly effective in teaching science vocabulary and engaging students in inquiry-based lessons. Students participate in a hands-on experiment during each lesson. The Student Response Guide helps them engage in the inquiry process. The student book, ScienceWork, provides extension activities that connect the student's world to science concepts. Using the Implementation Guide, teachers follow scripted lessons that provide clear direction for individual student accommodations If you purchase the Classroom Kit, materials and equipment needed for the experiments are included, except for food items and items commonly found in a classroom or at home. The storage bin provides extra space for storing materials you gather. These experiment materials make it easy to prepare for class. Also included is an Image Library on a disk that you can use for communication overlays and additional homework assignments. Extra ScienceWork student books and the Experiment Materials are available separately. By Ginevra Courtade, PhD, Bree Jimenez, MEd, Katherine Trela, PhD, and Diane Browder, PhD. ScienceWork, full-color, spiralbound, 104 pages; Implementation Guide, full-color, spiralbound; Student Response Guide, full-color, spiralbound, 121 pages, 2008. Teaching to Standards: SCIENCE is also part of our Core Curriculum Solution: Secondary. Teaching to Standards: SCIENCE Foundations The National Research Council (NRC) asserts that “inquiry is a set of interrelated processes by which scientists and students pose questions about the natural world and investigate phenomena; in doing so, students acquire knowledge and develop a rich understanding of concepts, principles, models, and theories” (NRC, 1996, p. 214). Within the National Science Education Standards (NSES), inquiry is described as a critical component of a science program. Through inquiry-based instruction, students can learn science in a way that represents how science actually works. Inquiry-based instruction requires more than hands-on activities. Students must follow a problem-solving process that is applicable to the real world. Similarly, students with significant disabilities need instruction that will help them solve problems that occur as part of real-world experiences. Using an inquiry-based approach to teach science to students with significant disabilities allows the students to experience and understand the environments they live in. It also creates the opportunity for access to the same instruction that their general education peers are receiving. Engaging students in inquiry helps students develop: - An understanding of scientific concepts - An appreciation of “how we know” what we know in science - An understanding of the nature of science - The skills necessary to become independent inquirers about the natural world - The dispositions to use the skills, abilities, and attitudes associated with science. Science as inquiry is basic to science education and is a controlling principle in the ultimate organization and selection of students’ activities. The standards on inquiry highlight the ability to conduct inquiry and develop understanding about scientific inquiry. Students at all grade levels and in every domain of science should have the opportunity to use scientific inquiry and develop the ability to think and act in ways associated with inquiry. Browder, D. M., Trela, K., Courtade, G. R., Jimenez, B. A., Knight. V., & Flowers, C. (2012). Teaching mathematics and science standards to students with moderate and severe developmental disabilities. The Journal of Special Education, 46, 26-35.
Scottish engineers have come up with a new way of dealing with asteroids that threaten the Earth - firing lasers at them from a swarm of small satellites flying in formation. "The use of high power lasers in space for civil and commercial applications is in its infancy and one of the main challenges is to have high power, high efficiency and high beam quality all at the same time," says Dr Massimiliano Vasile of the University of Strathclyde. "The additional problem with asteroid deflection is that when the laser begins to break down the surface of the object, the plume of gas and debris impinges the spacecraft and contaminates the laser. However, our laboratory tests have proven that the level of contamination is less than expected and the laser could continue to function for longer than anticipated." A century ago, the Tunguska meteorite showed just how much damage can be caused by an impact, with an object believed to be 30-50 metres in diameter devastating a 2000-kilometer area when it exploded in the atmosphere. "The Tunguska class of events are expected to occur within a period of a few centuries. Smaller asteroids collide with Earth more frequently and generally burn in the atmosphere although some of them reach the ground or explode at low altitude potentially causing damage to buildings and people," says Vasile. "We could reduce the threat posed by the potential collision with small to medium size objects using a flotilla of small agile spacecraft each equipped with a highly efficient laser which is much more feasible than a single large spacecraft carrying a multi mega watt." The system is scalable, so that more satellites could be added for a larger threat, and intrinsically redundant, so that if one spacecraft fails the others can continue. The same technique, says Dr Vasile, could be used to clear upspace debris, lowering the junk's original orbit to reduce congestion. "A major advantage of using our technique is that the laser does not have to be fired from the ground," he says. "Obviously there are severe restrictions with that process as it has to travel through the atmosphere, has a constrained range of action and can hit the debris only for short arcs."
Perennial plants can be propagated either by sexual or vegetative means. Sexual reproduction occurs when male pollen from one tree fertilises the ovules (incipient seeds) of the flower of another, stimulating the development of fruit. In turn this fruit contains a seed or seeds which, when germinated, will become a new specimen. However, the new tree will inherit many of the characteristics of both its parents, and it will not grow 'true' to the variety from which it came. That is, it will be a fresh individual with many unpredictable characteristics of its own. Although this is desirable in terms of increasing biodiversity and the richness of the gene pool (such sexual recombination is the source of most new cultivars), only rarely will such fruit trees be directly useful or attractive to the tastes of humankind. A tendency to revert to a wild-like state is common. Therefore, from the orchard grower or gardener's point of view, it is preferable to propagate fruit cultivars vegetatively in order to ensure reliability. This involves taking a cutting (or scion) of wood from a desirable parent tree which is then grown on to produce a new plant or 'clone' of the original. In effect this means that the original Bramley apple tree, for example, was a successful variety grown from a pip, but that every Bramley since then has been propagated by taking cuttings of living matter from that tree, or one of its descendants. The essentials of our present methods of propagating of fruit trees date from the time of the Romans, who were apparently the first to discover grafting. Classical authors wrote extensively about the technicals skills of fruit cultivation, including grafting techniques and rootstock selection. The oldest surviving named varieties of fruits date from classical times. The simplest method of propagating a tree asexually is rooting. A cutting (a piece of the parent plant) is cut and stuck into soil. Artificial rooting hormones are sometimes used to assure success. If the cutting does not die of desiccation first, roots grow from the buried portion of the cutting and it become a complete plant. Though this works well for some plants (such as figs and olives), most fruit trees are unsuited to this method. Root cuttings (pieces of root induced to grown a new trunk) are used with some kinds of plants. This method also is suitable only for some plants. A refinement on rooting is layering. This is rooting a piece of a wood that is still attached to its parent and continues to receive nourishment from it. The new plant is severed only after it has successfully grown roots. Layering is the technique most used for propagation of clonal apple rootstocks. The most common method of propagating fruit trees, suitable for nearly all species, is grafting onto rootstocks. These are varieties selected for characteristics such as their vigour of growth, hardiness, soil tolerance, and compatibility with the desired variety that will form the aerial part of the plant (called the scion). For example, grape rootstocks descended from North American grapes allow European grapes to be grown in areas infested with Phylloxera, a soil-dwelling insect that attacks and kills European grapes when grown on their own roots. Grafting is the process of joining these two varieties, ensuring maximum contact between the cambium tissue (that is, the layer of growing plant material just below the bark) of each so that they grow together successfully. Two of the most common grafting techniques are 'whip and tongue', carried out in spring as the sap rises, and 'budding', which is performed around July and August. Bud graftingEdit# Cut a slice of bud and bark from the parent tree. - Cut a similar sliver off the rootstock, making a little lip at the base to slot the scion into. - Join the two together and bind. - In time, the scion bud will grow into a shoot, which will develop into the desired tree. Whip and Tongue graftingEdit - Make a sloping cut in the rootstock with a 'tongue' pointing up. - Make a matching cut in the scion wood with a 'tongue' pointing downwards. - Join the two, ensuring maximum contact of the cambium layers. Bind with rafia or polythene tape and seal with grafting wax. Another reason for grafting onto rootstocks is that this enables the grower to determine the tree's eventual size. Apple tree rootstocks are referred to by numbers prefixed by letters indicating the developer of the rootstock. "M" or "MM" indicate East Malling, a pioneer in the development of dwarfing rootstocks. Rootstocks most often used, in order of eventual size, are; - M27: Extremely dwarfing - Produces a tree which is @ 6 ft (2 m) high. A good choice for container growing, or for very small gardens, although will require staking throughout its life, as well as frequent watering, weeding and feeding. Trees on this rootstock will begin to come into fruit after 2-3 years, reaching full capacity of 10 to 15 lb (5 to 8 kg) after 4-5 years. - M9: Very dwarfing - Reaches a height of 8 to 10 ft (3 m), coming into fruit after 3-4 years, reaching full capacity of 35 to 45 lb (20 kg) after 5 to 6 years. It will grow under average soil conditions, but needs a good rich soil to thrive. A good choice where space is limited and fertility is high. Permanent staking is required, as is routine feeding and watering. - M26: Dwarfing - Similar to M9 in effect, although somewhat more vigorous and generally stronger, with a higher expected eventual yield of 65-75 lb (35 kg) and height of 8 to 10 ft (3 m). A good choice where soil quality is average and compact growth is required. Comes into fruit after 3-4 years, reaching full cropping capacity after 5 to 6 years. Staking needed for first five years of its life. - MM106: Semi-dwarfing - Sometimes referred to as semi- vigorous, this is the most widely used of rootstocks. It is probably the best choice for the average garden under average conditions, being tolerant of a wide range of soils, and producing a tree with an eventual size of 14 to 18 ft (5 m). Trees on this stock begin producing fruit within three to four years, and yield up to 90 to 110 lb (50 kg) after some seven or eight years. MM106 is very suitable for use with weaker varieties that would produce under sized bushes with more dwarfing rootstocks. Can be trained as a half standard tree, but is rather too vigorous for cordons unless the soil is poor. Requires staking for the first five years or so of its life. - M111 & M2: Vigorous - Not generally suitable for garden scale growing, being both too large and spreading (18-25'), and too slow to come into cropping. They are however suitable for growing as specimen standards in the large garden, or for producing medium sized bushes on poorer soils. Begins to fruit after six or seven years, reaching full capacity of 160 to 360 lb (80 to 180 kg) after eight to nine years. - M25: Very vigorous - Suitable for a grassed orchard, and to grow on as a full standard. Plant 20 ft (7 m) apart, makes a tree of 15 to 20 ft (5 m) or more height and spread, eventually yielding 200 to 400 lb (100 to 200 kg) per tree. - Seedling: Very vigorous trees produced on a rootstock grown from seed. There is greater variability than with the vegetatively propagated rootstocks. Apples used for production of seedling rootstocks include 'Dolgo' and 'Antonovka', which are both extremely hardy and vigorous. The Malling-Merton series have been standard rootstocks for apples until recently. Now some are being replaced by new developments, including the Cornell-Geneva series. Some new rootstocks based on Siberian crab are being used in colder areas for more cold tolerance. Pears are usually grafted onto quince rootstocks, which produce small to medium sized trees. Some varieties however are not compatible with quince, and these require double working. This means that a piece of pear graft-work compatible with both the quince rootstock and the pear variety is used as an intermediate between the two. If this is not done the pear and the rootstock could eventually separate at the graft. Varieties that require double working include 'Bristol Cross', 'Dr Jules Guyot', 'Doyenné d' été' and 'Williams Bon Chrétien'. - Quince C: Moderately vigorous- Makes a bush pear tree about 8 to 18 ft (3 to 6 m) tall, bearing fruit within @ four to eight years. Suitable for highly fertile soils and vigorous varieties, but not where conditions are poor. Used for bush, cordon and espalier growing. Old stocks of Quince C may be infected with a virus, so care should be taken to obtain certified virus free stock. If in doubt, use Quince A as there is not a great amount of difference in vigour between the two. - Quince A: Medium vigour- Slightly more vigorous than Quince C, this is the most common variety upon which pears are grafted. Bears fruit between four to eight years, making a tree of some 10 to 20 ft (3 to 7 m) in height and spread. Suitable for all forms of pear trees except standards. Pear stock: Very vigorous- Pears grafted onto pear rootstocks make very large standard trees, not suitable for most gardens. Until the 1970s, cherries were grown of the vigorous Malling F12/1, Mazzard (Prunus avium), or Maheleb (P. maheleb) rootstocks, which required much space and time before cropping began, thus the growing of cherries was not a realistic option on a garden scale. The introduction of the rootstock 'Colt' enables trees reaching a maximum height of 12 to 15 ft (4 to 5 m) to be grown, and if trained as a pyramid it is possible to restrict growth to about 10 ft (3 m). The popular sweet variety 'Stella' could even be grafted onto a 'Colt' rootstock and successfully grown in a pot on the patio. Plum rootstocks include; - Pixy - A dwarfing rootstock, suitable for bush trees planted 8-10 (3 m) apart. - St. Julien A - A semi vigorous rootstock suitable for bush and half standards planted 12 to 15 ft (4 to 5 m) apart. Also suitable for peaches, nectarines and apricots. - Brompton or Myrobalan B- Suitable for half standards planted 18 to 22 ft (6 to 7 m) apart. Also suitable for peaches, nectarines and apricots. Own-Root Fruit TreesEdit Main article; Own-root fruit trees Some species of fruit are commonly grown on their own roots; new plants are propagated by rooting, layering, or modern tissue-culture techniques. In these cases there are may be no great advantages to using a special rootstock or improved rootstocks are not available. Fig, filbert, olive, pomegranate, gooseberry, bramble, and other fruits are commonly grown without any special rootstock. Though vegetative propagation of apple, pear, stone fruits, and many other species is a nearly universal practice, it does have some detractors. Here is an account of one advocate of own-root fruit trees. Own-root apples in a Permaculture designEdit Permaculture designer and fruit nurseryman Phil Corbett has for a number of years been working on an innovative project involving growing fruit trees on their own roots. His work is based on research carried out by Hugh Ermen of the Brogdale Horticultural Research Station, home of the National Apple Collection. Corbett writes; "Hugh discovered that there are several advantages in growing apples on their own roots- that is, not grafted onto a rootstock. The graft union, which is a union between two genetically different individuals, always creates a degree of incompatibility. Not having this incompatibility, own root trees were found to have better health and better fruit quality. The only disadvantage of own root trees is that most varieties are more vigorous than is usually wanted. This means that trees may make a lot of wood at the expense of fruit bud production, giving big trees that take a long time to come into crop. Conventionally this vigour is controlled by grafting onto a dwarfing rootstock. With trees on their own roots, however, a number of traditional techniques can induce early cropping. Once cropping begins, the tree's energies are channelled into fruit production and growth slows down to a controllable level. The techniques that are usually sufficient to bring about cropping are: - Withholding nitrogen, which would stimulate growth, and withholding irrigation, except in serious drought; - Tying down one and two year old branches to the horizontal. This induces fruit bud formation; - Prune in summer to stimulate fruit buds to form, and avoid winter pruning which stimulates regrowth. Once cropping has begun, a normal feeding and watering regime can begin. The average cropping own-root tree can be maintained at a size very similar to the same variety on MM106 rootstock" (Phil Corbett, from The Common Ground Book Of Orchards, pub Common Ground, 2000). He is also conducting research into the 'coppice-ability' of own-root fruit trees, including an experimental 'Coppice Orchard' project, wherein own-root trees are planted in north-south rows; "When the canopy of the orchard closes, a north-south row will be coppiced and the land in the row used for light demanding crops while the trees regrow. The trees on either side of the glade will have higher light levels on their sides and produce more fruit buds". Over time a series of parallel sheltered glades will be created which will be coppiced on a rotational basis, allowing for multifunctional use of land in order to produce not only fruit but also small wood products, soft fruit, vegetables and even possibly cereals, fungi and the more traditional bees and poultry. This is a project with much promising potential, and deserving of attention from the wider organic growing movement for the valuable lessons that will no doubt be provided over time. \|This page uses content from the English-language version of Wikipedia. The original article was at Fruit tree propagation. The list of authors can be seen in the page history. As with PermaWiki, the text of Wikipedia is available under the GNU Free Documentation License.\|
Differential equations are tested every year. The actual solving of the differential equation is usually the main part of the problem, but it is accompanied by a related question such as a slope field or a tangent line approximation. BC students may also be asked to approximate using Euler’s Method. Large parts of the BC questions are often suitable for AB students and contribute to the AB sub-score of the BC exam. What students should be able to do - Find the general solution of a differential equation using the method of separation of variables (this is the only method tested). - Find a particular solution using the initial condition to evaluate the constant of integration – initial value problem (IVP). - NEW Determine the domain restrictions on the solution of a differential equation. See this post for more on this. - Understand that proposed solution of a differential equation is a function (not a number) and if it and its derivative are substituted into the given differential equation the resulting equation is true. This may be part of doing the problem even if solving the differential equation is not required (see 2002 BC 5 – parts a, b and d are suitable for AB) - Growth-decay problems. - Draw a slope field by hand. - Sketch a particular solution on a given slope field. - Interpret a slope field. - Multiple-choice: Given a differential equation, identify is slope field. - Multiple-choice: Given a slope field identify its differential equation. - Use the given derivative to analyze a function such as finding extreme values - For BC only: Use Euler’s Method to approximate a solution. - For BC only: use the method of partial fractions to find the antiderivative after separating the variables. - For BC only: understand the logistic growth model, its asymptotes, meaning, etc. The exams so far, have never asked students to actually solve a logistic equation IVP Look at the scoring standards to learn how the solution of the differential equation is scored, and therefore, how students should present their answer. This is usually the one free-response answer with the most points riding on it. Starting in 2016 the scoring has changed slightly. The five points are now distributed this way: - one point for separating the variables - one point each for finding the antiderivatives - one point for including the constant of integration and using the initial condition – that is, for writing “+ C” on the paper with one of the antiderivatives and substituting the initial condition; finding the value of C is included in the “answer point.” and - one point for solving for y: the “answer point”, for the correct answer. This point includes all the algebra and arithmetic in the problem including solving for C.. In the past, the domain of the solution is often included on the scoring standard, but unless it is specifically asked for in the question students do not need to include it. However, the new CED lists “EK 3.5A3 Solutions to differential equations may be subject to domain restrictions.” Perhaps this will be asked in the future. For more on domain restrictions with examples see this post. Shorter questions on this concept appear in the multiple-choice sections. As always, look over as many questions of this kind from past exams as you can find. - 2017 AB4/BC4, - 2016 AB 4, BC 4, (different questions) - 2015 AB4/BC4, - 2013 BC 5 - and a favorite Good Question 2 and Good Question 2 Continued Multiple-choice examples from non-secure exams: - 2012 AB 23, 25 - 2012 BC: 12, 14, 16, 23 Schedule of review postings: - Tuesday February 27 – AP Exam Review - Friday, March 2 – Resources for reviewing - Tuesday March 6 – Type 1 questions – Rate and accumulation questions - Friday March 9 – Type 2 questions – Linear motion problems - Tuesday March 13 – Type 3 questions – Graph analysis problems - Friday March 16 – Type 4 questions – Area and volume problems - Tuesday Match 20 Type 5 questions – Table and Riemann sum questions - Friday March 23 Type 6 questions – Differential equation questions (this post) - Tuesday March 27 – Type 7 questions – miscellaneous - Friday March 30 Type 8 questions – Parametric and vector questions (BC topic) - Tuesday April 3 Type 9 questions – Polar equations - Friday April 6 Type 10 questions – Sequences and Series
Files are the building blocks of any application running under any OS. Files are also the software elements that administrators and users manipulate most of their workday. However, none of the Windows file systems (e.g., FAT, NTFS) follow an object-oriented schema. In other words, Windows file systems don't consider a file (or a folder) as an object with a fixed programming interface. To make Windows file systems recognize a file as an object, you need to use a tool such as the File System Object (FSO) model. With the FSO model's File object, you can manipulate files in VBScript applications. The File object represents a file in a Windows file system. After you access the File object, you can use the object's methods and properties to work with it. The File object has 12 properties that provide information about files and four methods that manipulate files. Accessing the File Object To work with a File object, you need a reference to it. You can obtain this reference in two ways, both of which rely on the FileSystemObject object. First, you can call the FileSystemObject object's GetFile method and specify the fully qualified filename (i.e., the absolute or relative path) of the file you want to access. Second, you can enumerate the items in the FileSystemObject object's Files collection and stop at the element whose properties match your criteria. Let's examine the pros and cons of both techniques. Using GetFile is the most common technique. This method takes one argument: the absolute or relative path to the file you want. If you specify the absolute path, the method returns a reference to the specified file in the specified directory. For example, the code Set fso = CreateObject _ ("Scripting.FileSystemObject") Set file = fso.GetFile _ ("C:\mydir\myfile.ext") returns a reference to the myfile.ext file in the MyDir folder on the C drive. If you specify the relative path, the method returns a reference to the specified file in the current directory. For example, the code Set fso = CreateObject _ ("Scripting.FileSystemObject") Set file = fso.GetFile _ ("myfiles\myfile.ext") returns a reference to the myfile.ext file in the MyFiles folder in the current directory. When you run VBScript code through the Windows Script Host (WSH) environment, the current directory is the one that contains the script file. Microsoft designed WSH this way for efficiency—you just have to specify the relative path in the script. GetFile can't handle ambiguous file specifications (i.e., filenames that can't be resolved in terms of a unique file). For this reason, you can't pass filenames with wildcards to GetFile. For example, if you run the code Set fso = CreateObject _ ("Scripting.FileSystemObject") Set file = _ fso.GetFile("C:\*.bat") you'll receive the error message File not found. If you need to scan all the files in a given folder, you use the Files collection technique. As the following code shows, you access the Files collection through the Folder object that I discussed last month: Set fso = CreateObject _ ("Scripting.FileSystemObject") Set f = _ fso.GetFolder("C:\mydir") For Each file In f.Files MsgBox f.Name Next The code loops through all the files in the My Dir folder. Each item in the Files collection evaluates to a File object. Accessing the File Object's Properties Many characteristics (e.g., name, location, size, type, creation date) help identify a file. The File object's properties let you retrieve those characteristics. To access a property, you use the syntax where fileObject is the referenced File object and Property is the property's name. As Table 1 shows, the File object has 12 properties. You use the Drive and ParentFolder properties to identify a file's location in terms of its drive and parent folder (i.e., the folder that contains the file), respectively. You can use the Path property to obtain a file's fully qualified path or the ShortPath property to obtain the 8.3 version of the path (i.e., a path containing an 8-character filename with a 3-character extension). You can use the ShortName property to retrieve the 8.3 version of the filename. The Size property returns a number specifying how many bytes a file is. The Type property returns a string that specifies the folder's type (i.e., the short description that Windows Explorer displays in its Type column in the Details view). Any file system element is characterized by one or more dates. With the DateCreated, DateLastAccessed, and DateLastModified properties, you can access a file's date of creation, last access, and last modification, respectively. An important point to consider when you're using the DateCreated property is that a file's creation date changes if you move the file from one machine to another. Windows' creation date isn't a per-file attribute that the file retains for its life cycle. Rather, the creation date is a per-system attribute that disappears when you copy the file to another storage medium. Unlike the other properties, the Attributes and Name properties are read/write. Here's how you assign attributes and filenames to a File object: The Attributes property. File attributes are the only information that the file system stores about a file. You use attributes to specify, for example, that a file is hidden or read-only. Table 2 lists the attributes that are relevant to files. To set an Attributes property, you use the property's optional newattributes argument, which has the syntax fileObject.Attributes _ \[= newattributes\] where newattributes is the new Attributes value you want the file to have. The Attributes value is a bitmask—that is, a numeric value whose meaning is determined by each bit's binary value. For the File object, the first bit is a constant with the value of 0. In other words, you can't set this bit programmatically. The second bit marks the file as read-only or read/write, depending on the bit's value. If the second bit is 0, the file is read/write; otherwise, it's read-only. Thus, for example, the code Set fso = CreateObject _ ("Scripting.FileSystemObject") Set file = _ fso.GetFile("C:\foo.txt") file.Attributes = 1 makes foo.txt a read-only file. The same scheme applies to all the other bits. (For more information about bitmask values, see my March 2000 column.) Because Attributes is a bitmask value, setting this property to a new value removes all existing attributes. For example, if foo.txt is a systems file and you set its Attributes property to 1, foo.txt doesn't become a read-only systems file but rather a read-only normal file. If you want to preserve some of the existing attributes, a better approach is to use code like that in Listing 1. This code uses an If...Then...Else statement to determine whether foo.txt is read-only. If not (i.e., the file is read/write), the code changes that attribute to read-only. This change doesn't affect any other file attributes. Thus, foo.txt becomes a read-only systems file. The Name property. To assign a value to the Name property, you use the syntax fileObject.Name \[= newname\] where newname is the new filename. You can use the Name property to indirectly rename files. (Microsoft didn't create a property or method in the FSO model that directly renames files.) The user-defined function called RenameFile in Listing 2 uses the GetFile method to retrieve the file you want to rename and the Name property to assign the new filename. Using the File Object's Methods The File object has four methods: Copy, Delete, Move, and OpenAsTextStream. The Copy method's syntax is fileObject.Copy destination _ \[, overwrite\] where destination is the location of the file after you duplicate it and overwrite is an optional argument that tells the method not to overwrite any existing file. By default, the Copy method overwrites existing files. You can change this default setting by specifying False (value of 0) for the overwrite argument with code such as Set fso = CreateObject _ ("Scripting.FileSystemObject") Set MyFile = _ fso.GetFile("C:\foo.txt") MyFile.Copy "C:\foo2.txt", 0 This code duplicates the file that the MyFile variable points to (foo.txt) in the same folder (the root of the C drive) but gives the file a different name (foo2.txt). If a file named foo2.txt is already in the folder, you'll receive the error message File already exists. The Delete method's syntax is where force is an optional argument that tells the method to delete read-only files. By default, the Delete method doesn't delete read-only files. To change this default setting, you specify True (value of 1) for the force argument with code such as Set fso = CreateObject _ ("Scripting.FileSystemObject") Set MyFile = _ fso.GetFile("C:\foo.txt") MyFile.Delete 1 The Move method performs the copy and delete functions in one operation. Its syntax is where destination is the location to which you want to move the file. For example, the code Set fso = CreateObject _ ("Scripting.FileSystemObject") Set MyFile = _ fso.GetFile("C:\foo.txt") MyFile.Move "C:\my documents\foo.txt" moves foo.txt from the root of the C drive to the My Documents folder on the C drive. The File object's Copy and Move methods don't accept wildcards. Therein lies the difference between these methods and the FileSystemObject object's Copy and Move methods. Both objects' methods achieve the same results. However, the FileSystemObject object's methods are more efficient because you can use wildcards to copy and move more than one file at a time. The OpenAsTextStream method provides a means to access and edit a file's content. Unlike the other three methods, OpenAsTextStream returns an object. (i.e., the TextStream object) Next month, I'll discuss the OpenAsTextStream method when I cover the TextStream object. To better understand how to use the File object's properties and methods, consider this example. Suppose you want to create a script that outputs a directory listing for a specified folder. You want the listing to specify each file's name, size, and attributes only. You can use the FSO model's File and Folder objects to develop a customized directory listing. As Listing 3 shows, you begin the script by declaring the constants and setting the folderName variable to the folder you want the directory listing for (in this case, the root of the C drive). Because you want to scan all the files in the specified folder, you obtain a reference to the Files collection and set that reference to the files variable. Next, you use a For Each...Next statement to loop through each file (f) in the files variable and apply the Name, Size, and Attributes properties to obtain the needed information. The code FormatAttrib(f.Attributes) calls the FormatAttrib function. This user-defined function converts the numeric attribute values (e.g., 2) into descriptive text (e.g., Hidden) so that the file attributes in the directory listing are easier to understand. After the script loops through all the files, the results appear in a message box like that in Screen 1. More Tools in Your Toolbox The File object's 12 properties and its Copy, Delete, and Move methods let you access, manipulate, and learn about files. However, these properties and methods don't let you access and manipulate the content of files. To work with the content, you need to use the File object's OpenAsTextStream method to access the TextStream object. Next month, I'll show you how to use this method and object to open files and write lines of text to them. - The fourth code example in the text contains an error. The code should read: Set fso = CreateObject("Scripting.FileSystemObject") Set f = fso.GetFolder("C:\mydir") For Each file In f.Files
Monoicous plants are those species that bear both sperm and eggs on the same gametophyte. Dioicous plants are those that have gametophytes that produce only sperm or eggs but never both. The terms are used largely but not exclusively in the context of bryophytes. Both monoicous and dioicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte. The states of being monoicous or dioicous are called monoicy and dioicy respectively. Etymology and history The word monoicous and the related forms mon(o)ecious are derived from the Greek mόνος (mónos), single, and οἶκος (oîkos) or οἰκία (oikía), house. The words dioicous and di(o)ecious are derived from οἶκος or οἰκία and δι- (di-), twice, double. (o)e is the Latin way of transliterating Greek οι, whereas oi is a more straightforward modern way. Generally, the terms "monoicous" and "dioicous" have been restricted to description of haploid sexuality (gametophytic sexuality), and are thus used primarily to describe bryophytes in which the gametophyte is the dominant generation. Meanwhile, "monoecious" and "dioecious" are used to describe diploid sexuality (sporophytic sexuality), and thus are used to describe tracheophytes (vascular plants) in which the sporophyte is the dominant generation. However, this usage, although precise, is not universal, and "monoecious" and "dioecious" are still used by some bryologists for the gametophyte. Bryophytes have life cycles that are gametophyte dominated. The longer lived, more prominent autotrophic plant is the gametophyte. The sporophyte in mosses and liverworts consists of an unbranched stalk (a seta) bearing a single sporangium or spore-producing capsule. Even when capable of photosynthesis, as in mosses and hornworts, bryophyte sporophytes require additional photosynthate from the gametophyte to sustain growth and spore development and are dependent on the gametophyte for their supplies of water, mineral nutrients and nitrogen. Antheridia and archegonia are often clustered. A cluster of antheridia is called an androecium while a cluster of archegonia is called a gynoecium. (Note these terms have a different meaning when used to refer to flower structures.) Bryophytes have the most elaborate gametophytes of all living land plants, and thus have a wide variety of gametangium positions and developmental patterns. Gametangia are typically borne on the tips of shoots, but may also be found in the axils of leaves, under thalli or on elaborate structures called gametangiophores. Bryophyte species may be: - Autoicous meaning that androecia and gynoecia are found on the same individual (monoicous) but in distinctly separate locations. If these are on separate branches, the term cladautoicous can be applied. - Synoicous (also called androgynous) bryophytes produce antheridia and archegonia interspersed in the same cluster. - Paroicous bryophytes produce antheridia and archegonia in separate clusters in different leaf axils. - Heteroicous bryophyte species may be either monoicous or sequentially dioicous depending on environmental conditions. This condition is also called polygamous or polyoicous. Role in survival There can be both selective advantages and selective disadvantages for organisms that are monoicous or dioicous. Monoicous bryophytes can easily reproduce sexually, since both sexes can be found on the same organism. On the other hand, this can lead to inbreeding and reduce genetic variation within populations. Dioicous organisms necessarily exchange genes with other organisms of the species during sexual reproduction, increasing heterozygosity and variability (given a sufficiently large variable mating population). If isolated, however, organisms may only reproduce asexually, which could present a severe selective disadvantage over time. Bryophyte sperm dispersal can therefore be key to species longevity, particularly in dioicous species. While sperm dispersal is typically passive, with sperm dispersing through water, certain species exhibit very active dispersal mechanisms, such as aerial dispersal recently described in the liverwort Conocephalum conicum. - Crandall-Stotler, B.J. & Bartholomew-Began, S.E. (2007). Morphology of Mosses (Phylum Bryophyta). In: Flora of North America Editorial Committee, eds. (1993+). Flora of North America North of Mexico. 16+ vols. New York and Oxford. Volume 27, 2007. - Bell, P.R. & Helmsley, A.R. (2000). Green plants, their origin and diversity (2nd ed.). Cambridge University Press. - Shaw, A. Jonathan & Goffinet, Bernard eds. (2000). Bryophyte Biology. New York: Cambridge University Press. - See e.g. Taylor, Eppley & Jesson 2007. - Thomas, R.J., Stanton, D.S., Longendorfer, D.H. & Farr, M.E. (1978) "Physiological evaluation of the nutritional autonomy of a hornwort sporophyte". Botanical Gazette 139: 306–311. - Glime, J.M. (2007). Bryophyte Ecology. Vol. 1. Physiological Ecology. Ebook sponsored by Michigan Technological University and the International Association of Bryologists. Accessed on 4 March 2013 at http://www.bryoecol.mtu.edu/chapters/5-9Sporophyte.pdf. - Taylor, P.J.; Eppley, S.M. & Jesson, L.K. (2007). "Sporophytic inbreeding depression in mosses occurs in a species with separate sexes but not in a species with combined sexes". American Journal of Botany 94 (1853-9). - Masaki Shimamura, Tomio Yamaguchi & Hironori Deguchi (2007). "Airborne sperm of Conocephalum conicum (Conocephalaceae)". Journal of Plant Research 121(1):69–71.
- A hacker is a person who creates and modifies computer software and hardware for either negative or positive reasons. Criminal hackers (cybercriminals) create malware in order to commit crimes.Hacking tools are programs that generally crack or break computer and network security measures. Hacking tools have different capabilities depending on the systems they have been designed to penetrate.Hacktivism can be described as the use of malicious techniques such as denial of service attacks for political reasons, instead of for monetary gain or personal reasons.Hash values can be thought of as fingerprints for files. The contents of a file are processed through a cryptographic algorithm, and a unique numerical value – the hash value - is produced that identifies the contents of the file.Heuristics is a scanning method that looks for malware-like behavior patterns. It is commonly used to detect new or not-yet-known malware.Hoaxes are emails typically arriving in chain letter fashion that often describe impossible events, highly damaging malware or urban legends. Their intent is to frighten and mislead recipients and get them to forward to friends.Hyper-Text Transfer Protocol (HTTP) is used to transfer information, such as HTML documents, on the Internet.Hyper-Text Transfer Protocol Secure (HTTPS) is a variation of HTTP that uses the Secure Socket Layer to increase security.
Build sentences with CVC words and sight words. Sentence building is a fun way for students to practice phonics fluency and sentence formation. Simply cut out the words at the bottom, rearrange the words to form a sentence that matches the picture. Paste the sentence next to the picture. Let’s have a peek at the activities below.
According to the government’s ‘Working Together to Safeguard Children‘ white paper: nothing is more important than children’s welfare. The system is designed to respond to the needs and interests of children and families, and how they work needs to run in partnership with other interested parties. Schools play an essential role in protecting children from abuse, and with regular contact with young people they are in a strong position to identify signs of abuse and neglect. But with events such as severe flood and coronavirus affecting the country, increasingly schools are turning to home learning to ensure children still receive an education. But how can the school ensure pupils are still safeguarded whilst off-site? This blog post explains. What is safeguarding? According to Keeping Children Safe in Education guidelines (2019), safeguarding is defined as: - protecting children from maltreatment; - preventing impairment of children’s health or development; - ensure that children grow up in circumstances consistent with the provision of safe and effective care; - taking action to enable all children have the best outcomes. Why is it important to safeguard children? No one deserves to be abused whether it be physical, sexual or emotional abuse and no child or young person deserves to be neglected and we as a society have a duty to protect them from harm. Every child deserves to live without the fear of harm or abuse. If we protect children from harm they are more likely to grow up into confident members of society. Children with a disability are three times more likely to experience abuse and neglect and it’s up to us as practitioners to recognise the signs and symptoms to protect all children. How your school can safeguard children No single practitioner can have a full picture of a child’s needs and circumstances. If children and families are to receive the right help at the right time, everyone who comes into contact with them has a role to play in identifying concerns, sharing information and taking prompt action. Schools play an essential role in protecting children from abuse. Your school can safeguard children (according to the NSPCC) by: - Creating a safe environment for children and young people through robust safeguarding practices - Ensure that adults working within the school do not pose a threat to children - Ensure staff are trained and know how to respond to concerns - Teach children and young people about staying safe - Maintain an environment where children feel comfortable to approach any staff member if they have a problem Personal, Social, Health and Economic (PSHE) education is a school subject through which pupils develop the knowledge, skills and attributes they need to manage their lives, now and in future. These skills and attributes help pupils stay healthy, safe and prepare the for life and work in modern Britain. Training staff in key areas such as Child Sexual Exploitation, gangs and county lines, staying safe online, peer on peer abuse, Female Genital Mutilation, modern slavery and trafficking is essential. All staff need to be equipped with the knowledge and skills of these prevalent safeguarding concerns so they can identify those at risk and put safeguarding measures in place. Schools should consider incorporating contextual workshops for pupils based on the above concerns within PSHE lessons, giving students the skills to self-identify when they are at risk, and promote confidence in seeking help and support. Milly Wildish, safeguarding expert and director of Keys to Safeguarding explains: Schools that have robust safeguarding policies and procedures, complemented with effective training, supporting the message that safeguarding is everyone’s responsibility are in a much better place to fulfil their statutory duty to protect children from harm. Transparency of a school’s safeguarding policies and procedures provide pupils and parents the reassurance that safeguarding is a priority, staff are skilled to identify children at risk and any concerns a pupil raises will be listened to and acted upon. What are the safeguarding requirement when the student is based off-site? The Education and Inspections Act 2006 required schools to provide, by September 2007, full-time and suitable education from day six of a pupil’s fixed period exclusion. The provision could be located off site or in provision shared with other schools. Local authorities were required to make suitable arrangements for permanently excluded pupils from day six of the exclusion, replacing the expectation that they make provision from day 16. An alternative provision can also be provided due to illness. Schools are responsible for the safeguarding of their pupils when they’re placed in an alternative provision. The new guidance says that schools should obtain a written statement from the provider that they have completed all the vetting and barring checks that are necessary on their staff. All providers must have safeguarding policies and processes which should include: - A robust process for all staff (including designated and safeguarding lead) to record any discussions or actions in terms of safeguarding concerns. - A secure, individual safeguarding file. This should include all information and actions for identified safeguarding issues. - The process identified for staff to pass on all safeguarding concerns to their designated safeguarding lead or provider manager. - The process for which the safeguarding lead to refer all concerns to Children’s social care. - Referring any child or young person not on school roll to the Children Missing from Education Team. The benefits of eyes-on learning A key tool in providing any documentation is to provide thorough and accurate information. When learners are off-site it can be difficult to obtain the information necessary to safeguard children, but EDClass+ from EDLounge Limited has various safeguarding protocols in place. One of the benefits is eyes-on learning. Students can access the support mechanism instantly once they have accessed the online virtual classroom. With a webcam enabled, teachers can report any concerns they may see onscreen. Learners can also ask for assistance anytime via face to face, verbal chat, instant chat, written chat and questions and answer sessions. All EDLounge staff are enhanced DBS checked and have received regular and extensive safeguarding training in how to safeguard children in practice. EDClass+ offers 11,000 lessons with the aim of fully inclusive tailored learning. For more information, click here.

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