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With Occupational Therapy week celebrations kicking off over the weekend, I thought this would be a great chance to answer some questions about Paediatric Occupational Therapy and rediscover some of the things that make OT so great! What is OT? Occupational therapy is an allied health profession that focusses on building skills and improving participation in daily activities, so people can reach their pOTential! For kids, these skills and activities can be anything from using cutlery, brushing their teeth, managing their belongings, building and maintaining friendships to following instructions, coping with change, handwriting, throwing and catching, riding a bike, toileting or engaging with their environment. Why would a child need to see an occupational therapist? A child may see an occupational therapist for Occupational Therapy if they are not performing at an age appropriate level for any of the following: - self-care skills: bathing, dressing, feeding, toileting - fine motor skills: handwriting, drawing, buttons, zips, opening packets, using cutlery - gross motor skills: throwing and catching, climbing, balance, coordination - social/play skills: turn taking or sharing, asking to play, managing friendships, winning/losing appropriately - cognitive skills: attention, organisation, memory, - behavioural, emotional or sensory regulation Although a child does not need a diagnosis to see an occupational therapist, children with the following diagnosis may be more likely to require occupational therapy input during childhood: - Autism Spectrum Disorder - Cerebral Palsy - Intellectual Disabilities - Coordination Disorders - Sensory Processing Disorders or Sensory Impairments - Developmental Delays What might a first session look like? It is important before we begin intervention that we have a thorough understanding of the child. This includes gathering a birth history, family history, information about the child’s performance, environment, main daily activities and any concerns the parent may have. This is often completed by a questionnaire and/or discussion with the parents and completion of observations and standardised testing of the child. What are some standardised tests that might be used? - Sensory Profile 2 – an outline of a person’s sensory preferences compared to the majority of the population - Bruininks-Oseretsky Test of Motor Proficiency (BOT-2) – a comprehensive index of the child’s overall motor proficiency in fine motor skills and gross motor skills. - Test of Visual Perceptual Skills – a test of visual processing and perception - Beery Developmental Test of Visual Motor Integration (VMI) – measures eye-hand coordination, motor control as well as visual information processing - Vineland Adaptive Behaviour Scales – measures adaptive behaviours in the domains of communication, daily living skills, socialisation, motor skills and maladaptive behaviour How long would a child receive intervention for? Every child is different and has different needs, so its hard to say. A child would continue to have intervention whilst there were achievable goals they are working toward. Sometimes a child will have regular sessions either in the clinic, at home or at school to work directly with their therapist to build skills, other times, a family may be given strategies or a program to be completed at home. Do I need a referral to see an OT? A referral is not necessary if you have concerns regarding your child’s development, you are able to book in an assessment with an occupational therapist, however we regularly receive referrals from: - Speech Pathologists - School Teachers What funding options are available for assessment and intervention? If you have concerns about your child and would like them to see an occupational therapist, there are a few options that may assist with funding therapy. These are: - Medicare Enhanced Primary Care Plan – Please speak to your GP regarding this - National Disability Insurance Scheme – https://www.ndis.gov.au/about-us/contact-us - Private Health Funds
Table of Contents Wind power is one of the naturally available source of energy in the community. It is evident that wind happens to be available in most locations across the globe. However, there are great variations in the intensity and speed of the wind across the globe. The areas which have an adequate supply of wind energy may take advantage of the resource to produce electricity. In order to tap the resource to produce electricity, the stakeholders in the community may have to set up a wind firm. Generally, it may require setting wind turbine in an ideal location where they would the wind. Wind is responsible for the conversion of kinetic energy to electrical energy. Wind rotates the blades which are connected to a generator. The rotation of the blades stimulates the movement of the shaft which is attached to a motor. The motor consists of electro-magnets which are surround by copper coils. The rotation of the shaft result into electromagnetic induction which degenerates into electrical energy. The electrical energy is channeled into transformers which increase the voltage for long distance transmission. Whenever the current reaches fuse boxes and substations, the voltage is lowered to meet the energy needs for domestic and home use. An insight into factors which have a bearing on the quality of wind produced makes it clear that the quality of the wind supplied and nature of blades used could have an impact on the sustainability and the performance of the wind energy system. An effective approach in overcoming the hurdle may entail making an ideal selection of the location for the wind power system. It may also be prudent to make an ideal selection of the blades which would match the wind supply to the location. Such a move will ensure sustainability of the wind power systems and also improve their performance. - Excellent quality - 100% Turnitin-safe - Affordable prices Energy is a key requirement for the successful completion of most domestic and industrial activities. There are several approaches towards energy generation in the community. Some of the common energy systems in the community include the wind energy systems, the solar energy systems, nuclear energy system, and hydro-electrical energy systems. It is apparent that the different energy systems make use of different approaches for them to generate energy. The wind energy system is of particular importance in this research. It is of one of the most commonly used energy system in the community. Essentially, wind entails the flow of air. The wind power is generated whenever air flows through wind turbines. The rotation of the turbines powers on generators which result into the production of energy. Wind power has served an alternative to power sources such as fossil burning. It merits noting that wind power is always available in plenty and cannot be exhausted. Notably, there is little or no emission of greenhouse gases as a result of the process for producing energy using wind. Scholars have affirmed that the net effects of wind energy systems on the environment are far much less than those which result from the burning of fossil fuels. An insight into the system makes it clear that the wind farms in most of the cases consist of many individual turbines which are connected to the electrical transmission network. It is thus evident that it is utilized in conjunction with the other power sources in the community in the bid to attain a reliable supply of energy. In the cases where the proportion of wind power supply increases, there is a need to upgrade the grid in the attempt attain a reliable supply of electricity to the consumers. It further merits noting that weather forecasting could make it possible to predict the variations in the wind supply which could have an effect on the variations of energy produced. An understanding of the wind energy system would be incomplete without taking into limelight the physical processes, involved in the system in terms of thermodynamics, heat generation, energy losses, and loss transfer. The research aids in the identification and critical analysis of the controlling processes that determine the performance of the wind energy system. It further explores any sustainability and energy performance issues which could present in the system. It also explores a proposition which could possibly help overcome the issues identified in the system. It is of great essence to have an understanding of the physical processes which are involved in the generation of power from the wind systems. Basically, in order for one to generate electricity from the wind systems, they require to have turbines connected to generators which are eventually connected to a grid system. The wind essentially converts the kinematic energy in the wind to produce electrical energy. It takes place through the use of large wind propellers which are connected to generate to produce electricity. It is apparent that as the wind gaps the turbines, it result in moving the blades and thus spinning the shaft. Horizontal and vertical axes are types of wind turbines in use. The horizontal axis wind turbines contain propellers which have fan-style blades which are used commonly (Xu, Ruan, Mao, Zhang, and Luo 2013). The vertical axis wind turbines on the other hand have an egg-beater style turbine. However, the physical process involved in the generation of electricity are the same. The blades of the wind turbines are responsible for the conversion of energy. An insight into the working of blades makes it clear that there are basically two types of blades, the drag type and the lift type (Zhao, and Rasmussen 2015). In the drag type, they are designed to in such a way that the blades make uses the forces of the wind to push the blades around. It is clear that such blades tend to have a higher torque than the lift type though they are associated with a slower rotating speed. The design of the blade types aimed at generating energy for use in such activities such as crushing and slicing. The slow aspect of their rotation makes it evident that they may not be ideal for generation of large scale energy. An insight into the lift types makes it clear that most modern wind power generating systems make use of their design. It is apparent that both sides of the vanes have wind driven across it which results in the air staying for a relatively lengthier duration of time to travel across the ends. The design makes it possible for the creation of inferior air pressure on the principal edge of the blade and greater compassion is created on the rear end. The differences in the air pressure result into pushing and pulling the blade around which result into the creation of a higher rotation speed which is necessary for the generation of electricity. An overview of the process that results into the creation of electricity makes it clear that the raceway of the turbines should be connected to a generator. The generator utilizes the turning motion of the shaft to rotate motor which has oppositely arraigned electromagnets and is surrounded by coils of cooper wire. The spinning of the motor results into electromagnetic induction which results into the generation of electricity. It merits noting that the electricity produced by from the power system sought to go through a transformer (Syahputra, Robandi, and Ashari 2014). The transformer plays a critical role in maximizing the voltage along long distance. Consequently the power stations and the fuse frames receive the current and transmute it into low voltage which would be idea for domestic use and businesses. An insight into the wind power system makes it clear that there are a number of factors which determine the performance of the system in generating electricity. The primary factor which has a significant bearing on the ability of the system to efficiently produce electricity is wind. It is clear that the speed of wind is never constant. It is apparent that the variations in the speed of wind has greatly influences the capacity of the wind farm. In most of the cases, it is evident that the power plans tend to produce below their capacity. The move results into a high degree of variations in the electric power produced. It is clear that the variations could be hourly, daily and in some of the cases they could be seasonal. However, it is clear that in most of the cases, the rate of consumption by domestic and business enterprises in the community tends to be relatively constant. It is thus likely that the variations in the amount of electricity produced could be pose a challenge in balancing the amount of electricity available in the national grid system. In any case, it clear that the demand for electricity in the community has been on a persistent increase. It further merits noting that there challenges associated with the variations in the amount of electricity I the grid system (Wan, Pinson, Dong, and Wong 2014). There are cases when the wind farms have made an attempt tom predict the wind power. However, it is evident that the predication only serve to forecast short term trends in the wind patterns. It is thus evident that it may be relatively tough to rely on wind power for long term planning of the energy needs in for a community. The second factor which has a great bearing on the amount of energy produced by the wind power firms is the nature of blade strengths, their weight and the general performance of the wind turbines. It is clear that the power output of a wind turbine greatly depends on the efficiency of the blades, the alternator and the dynamo. The power output of bigger and taller turbines is relatively great due to the aspect that wind speeds are greater at higher altitudes. One can possibly enhance the efficiency of the blades by ensuing they face the direction of the wind. It is apparent that in the cases where there is no reliable supply of wind in the location, and poor choice of blades, then it is likely that the energy supplied would not be sustainable and it would have an implicit effect on the performance of the system. However, an ideal choice of location of the wind power generating system would get a long way in ensuing that the power produced is reliable. There are a number of approaches which could be ideal in addressing of the limitations which are associated with wind power systems. In the bid to improve on the aspect of wind, it may be of pivotal importance in most of the cases to conduct extensive location of the stations for producing electricity. It is apparent that certain locations in the community tend to have a great supply of wind at a relatively high speed. Such locations would be ideal for setting up a station. Notably, areas which are high altitudes and generally hilly have a better chance in being reliable in terms of setting up wind turbine station. Such a location would be ideal in overcoming the challenges which are associated with variations in the speed of wind and its intensity. It may be necessary to have a thorough consideration of the nature of blades which are to be used in the wind turbines. It is evident that the design of the turbines has a significant bearing on the amount electricity produced (Wan, Pinson, Dong, and Wong 2014). It is evident that using taller blades may be an ideal approach. It may be prudent to make use of blades which are string in the bid to ensure they can withstand extremely windy conditions. It may also be necessary to undertake a consideration of the weight of the blades. Extremely heavy blades may require wind of the extreme intensity for them to turn round. In such a case, it may be necessary to ensure that the weight corresponds to the intensity of wind in the given location. One should also aim for turbines with can depict a strong performance. A thorough consideration of the performance of the turbines would definitely enhance reliability of the electricity generated. It is evident that energy is an essential component of running our daily activities whether at our home or even in industrial use. An insight into the energy systems in the community makes it clear that there are various approaches towards the generation of electricity. Some of the common forms of energy systems in the community include hydro-electrical power stations, nuclear power stations and wind power systems. An insight into the wind power systems makes it clear that the system highly relies on wind to generate electricity. An insight on how electricity is produced make it clear that the wind turns the turbines to produce electricity. Wind converts the kinetic energy to electrical energy. Upon turning of the blade, they turn a motor which contains several copper loops. The copper lops are surrounded by strong magnets. The turning of the motor results into the generation of electromagnetic induction which in turn is harnessed to produce electricity. The electricity is channeled to transformers which increase the voltage so to make it possible to transmit the electric current for long distance. In the cases where the power gets to the stations and fuse boxes, the voltage in minimized so that it can serve the domestic needs. An insight into the factors which could have an implicit effect on electricity generation using the approach makes it evident that the supply of wind and the nature of the turbines used could have an implicit effect on the nature energy produced. It merits noting that the above factors may have an implicit effect on the sustainability of the energy system. There are cases where the factors could adversely affect electricity production using the approach. An effective way to improve the above factors may entail making an ideal choice of the location for the wind power systems. A corresponding selection of better blades that match the location could help enhance the sustainability of the power generation system. It is apparent that wind power systems could be an ideal source of electricity. It is undeniable that the energy system is friendly to the environment than other modalities utilized in the production of electricity. It is apparent that there are various challenges associated with using the approach to produce electricity. However, it is one of the best approaches towards meeting the needs of the community in producing electricity. - Zhao, H., Wu, Q., Hu, S., Xu, H. and Rasmussen, C.N., 2015. Review of energy storage system for wind power integration support. Applied Energy, 137, pp.545-553. - Syahputra, R., Robandi, I. and Ashari, M., 2014. Performance analysis of wind turbine as a distributed generation unit in distribution system. International Journal of Computer Science & Information Technology, 6(3), p.39. - Xu, L., Ruan, X., Mao, C., Zhang, B. and Luo, Y., 2013. An improved optimal sizing method for wind-solar-battery hybrid power system. IEEE transactions on Sustainable Energy, 4(3), pp.774-785. - Tang, Y., He, H., Wen, J. and Liu, J., 2015. Power system stability control for a wind farm based on adaptive dynamic programming. IEEE Transactions on Smart Grid, 6(1), pp.166-177. - Wan, C., Xu, Z., Pinson, P., Dong, Z.Y. and Wong, K.P., 2014. Probabilistic forecasting of wind power generation using extreme learning machine. IEEE Transactions on Power Systems, 29(3), pp.1033-1044.
According to the World Health Organization, antibiotic resistance is one of the biggest threats to global health today. What is antibiotic resistance? Antibiotic resistance means that bacteria have become resistant to the antibiotics designed to kill them. Bacteria, not humans or animals, become antibiotic-resistant. These bacteria can infect humans and animals, increasing the difficulty of treating bacterial infectious diseases, according to the ARS (Antibiotic Resistance Surveillance). As a consequence, antibiotic resistance leads to higher medical costs, prolonged hospital stays, and increased mortality. Nowadays, we are having an acceleration of this problem due to the misuse and overuse of antibiotics. How to treat bacterial infections? RAMPmedical helps doctors to understand what treatment is the optimal one based on the bacteria the patient has in four steps: Enter the relevant patient details. The algorithms that run behind the RAMPmedical software help to know which bacteria probably causes the infection. The software adapts the result to the patient characteristics and shows the optimal treatments for this case. Choose the best therapy for your patient. Finally, the World Health Organization recommends to explain to your patients how to take antibiotics correctly, what antibiotic resistance is, and the dangers of misuse.
Infants love playing with balls. Ball play is not just a motor learning activity, but a learning opportunity to support children’s STEM learning. During the ball play, children can learn about the properties of balls and discover how balls can move in different ways. - Activity cards (playtime, daily routines) Level of Intended Impact: - Knowledge application Routines and Everyday Activities: - Playtime (indoors & outdoors) Resources for Families: - Discovery Play Activities
Seasonal Variations and the Immune System How Do Seasonal Changes Affect the Immune System? Research published in the International Journal of Preventive Medicine explain how seasonal changes in temperature, air quality, humidity, and exposure to sun light affect the immune response. These seasonal variations can affect the functioning of the lymphatic system generally, and immune functions such as functioning of the T cells and white blood cell production specifically. Interestingly, there has not been conclusive evidence to suggest a direct link between low temperatures and immune response to infection. However, researchers have observed indirect links between cold temperature and immune response. This indirect link derives from the changes in human behavior due to these environmental factors – such as staying indoors and lethargy – have a significant impact on immune response. Staying indoors robs the body of exposure to natural light, and lethargy brings a host of immune and general bodily functioning deficiencies including poor circulation, sleep irregularities, mood imbalances, and energy level depletion. It has also been suggested that it is the crowding which occurs from staying indoors during the cold – rather than the temperature itself that promotes the spread of infections. However, some external factors (other than temperature) and behaviors have been shown to affect the ability of viruses and bacteria to spread. This article will focus on two key factors affecting immune response: exposure to sun light and humidity (or, alternatively, air dryness). Sunlight, Vitamin D, and the Immune System Exposure to sunlight can affect mood, energy levels, and immune function. Specifically, as research from the Endocrinology and Metabolism Clinics of North America found, exposure to sunlight is one of the most fundamental ways – other than diet - in which the body endogenously produces vitamin D. While the exact mechanisms underlying the connection between vitamin D levels and immune functioning remain unclear, it is widely known that vitamin D plays a vital role in maintaining healthy functioning of the body’s organs and systems. Vitamin D level – sufficiency or deficiency – have long been linked to susceptibility to infection. According to endocrinologists, “Vitamin D3 plays a prominent role in immune health”. Vitamin D is a key component in the bodies cellular metabolic processes. Vitamin D improves immune system functioning by regulating (and stimulating) the production of neutrophils (a type of white blood cell), macrophages, dendritic cells, B cells, and T cells, all of which serve frontline immune-defensive roles. Humidity and the Immune System In the same article published in International Journal of Preventive Medicine, humidity, and its alternate dryness of the air has been shown to have a connection with the spread of infections. Dry air in particular has been shown to increase the ability of viruses, particularly respiratory viruses, to spread, though the exact mechanism through which this relationship works is yet unknown. It is proposed that moisture (from humidity) disallows the virus to spread through dust. How Can Red Ginseng Boost the Immune System? According to work published by the Journal of Ginseng Research, ginseng has been clinically shown to regulate the production of macrophages, dendritic cells, and Natural Killer cells, which all serve key functions in the body’s ability to fight off viral and bacterial infections. Korean Red ginseng is particularly effective as it is processed to provide the optimum power of ginseng’s health benefits. In this way, ginseng can counteract the effects of vitamin D deficiency by performing the same types vital immune functioning regulatory tasks. Ginseng also stimulates the response of antibodies in the immune system which ward off invasion by harmful microbes. Thus, ginseng counteracts the seasonal immune functioning deficiencies associated with decreased sunlight exposure, boosting the immune system’s response when it is most likely to be invaded by viruses and bacteria whether due to drops in humidity or enclosure during the colder months. Korea Ginseng Corp Korea Ginseng Corp sells the best Korean red ginseng products to support your overall health. Korea Ginseng Corp offers Korean Red Ginseng products in the form of delicious and healthy teas, candies, tonics, and more that can help you power through your day in a healthy and sustainable fashion. Korea Ginseng Corp’s skincare line, Donginbi, offers a variety of products to your keep skin looking young and healthy as well. -CheongKwanJang, Health Benefits, Health Supplements, How To's
Carbon monoxide is a silent killer that claims the lives of hundreds of people every year. It is a colorless, odorless gas. One that is produced whenever fuels like gas, oil, or wood are burned. Many people are unaware of its dangers and fail to recognize the symptoms until it is too late. As a highly skilled assistant who specializes in content writing and digital marketing, I understand the importance of raising awareness about this deadly gas. In this article, we will explore what makes carbon monoxide so deadly, how it can be detected, and most importantly, how it can be prevented. By the end of this article, you will have a better understanding of the dangers associated with carbon monoxide and what steps you can take to protect yourself and your loved ones. So sit back, relax, and let’s dive into the world of carbon monoxide. As the Campaign talked about WASHINGTON, Feb. 26, 2015 — It’s colorless, odorless and can be deadly. Carbon monoxide is no joke, especially in the winter when people will do just about anything to warm up. Raychelle Burks, Ph.D., explains why carbon monoxide is so dangerous, and how you can stay safe, in the latest episode of the Reactions series Get To Know A Molecule. Check it out here: http://youtu.be/lMnaLKlVXxo. Source: American Chemical Society No they are NOT a sponsor but indoor air quality matters. Heck, even LEED cares about it. Carbon monoxide (CO) is a colorless, odorless gas that is unsafe for humans and the environment. It comes from the incomplete combustion of fossil fuels, biomass, and other organic sources. Although CO is toxic to humans, it is most dangerous when it accumulates in confined places like your home, car, or workplace. That’s because CO binds to hemoglobin, which is present in the blood. When this happens, it can slow blood flow to the heart and increase the risk of cardiac arrest and death. While CO can be released accidentally, it is also sometimes intentionally released as an industrial or agricultural gas.
Let’s talk about everyone’s favorite topic of conversation: the weather. Specifically, we’re diving (oops, we mean exploring!) into the distinction between two types of precipitation: drizzle and rain showers. When it comes to rainfall, these two terms are often used interchangeably, but there are some essential differences that we’ll be unraveling in this article. So grab your umbrella and join us on this rainy adventure as we uncover the dissimilarities between drizzle and rain showers! Table of Contents Definition of Drizzle and Rain Showers Definition of Drizzle Drizzle refers to a light, fine precipitation of water droplets that fall from the atmosphere. It is characterized by the droplets being smaller in size and falling slowly, creating a mist-like effect. Drizzle often occurs in the form of tiny droplets that are less than 0.5 millimeters in diameter. Definition of Rain Showers Rain showers, on the other hand, are a more intense form of precipitation than drizzle. They involve larger water droplets falling from the sky at a faster rate. Rain showers are usually associated with cumulus clouds and occur when warm, moist air rises rapidly, condenses into water droplets, and then falls as rain. Rain showers can vary in intensity and duration. Causes and Formation Causes of Drizzle Drizzle is commonly associated with stable air masses and shallow cloud formations. It occurs when a layer of moist air is lifted gently, usually from a frontal system or a low-pressure area. As the air rises, it cools and reaches its dew point, causing water vapor to condense into tiny droplets. Due to the gentle updrafts and the limited moisture in the air, the droplets remain small and fall slowly, creating a drizzle. Formation of Drizzle Drizzle is often formed in stratiform clouds, characterized by their uniform horizontal development. These clouds are typically low-lying and extend over large areas. As warm air rises and cools within these clouds, water vapor condenses into tiny droplets that remain suspended. These droplets are then slowly deposited to the ground as drizzle. Causes of Rain Showers Rain showers are typically associated with convective processes involving the rapid upward movement of warm, moist air. Various factors, such as a cold front, vertical air motions, or the convergence of different air masses, can trigger this uplift. The ascent of the warm air causes it to cool, resulting in the condensation of water vapor and the formation of rain showers. Formation of Rain Showers Rain showers often form in cumulus clouds, characterized by their vertical development and puffy appearance. These clouds are created by solid updrafts of warm air, which cause the air to rise rapidly and condense into water droplets. The droplets continue to grow as they collide with other droplets, eventually becoming heavy enough to fall as rain. Intensity and Duration Intensity of Drizzle Drizzle is generally characterized by its light intensity. The small size of the water droplets contributes to its gentle fall towards the ground, resulting in mist-like precipitation. Drizzle is typically not associated with heavy downpours or strong winds. Duration of Drizzle Drizzle can last extended periods, ranging from a few minutes to several hours. It often occurs in regions with persistent cloud cover and stable atmospheric conditions. The drizzle’s low intensity and slow-falling nature allow it to linger in the air for longer durations than other forms of precipitation. Intensity of Rain Showers Rain showers can vary significantly in intensity. They can range from light showers with a gentle fall of raindrops to heavy showers accompanied by thunderstorms and gusty winds. The intensity of rain showers is often influenced by factors such as the strength of the convective process, the amount of moisture in the air, and the dynamics of the weather system. Duration of Rain Showers The duration of rain showers can vary greatly. Some rain showers may last only a few minutes, while others can persist for several hours. The duration depends on the atmospheric conditions, the convective process’s strength, and the weather system’s movement. Rain showers often have a transient nature, with periods of rain followed by breaks of dry weather. Size of Raindrops and Water Droplets Size of Raindrops Raindrops can vary in size depending on the atmospheric conditions and the dynamics of the cloud system. On average, raindrops have a diameter ranging from 0.5 to 6.5 millimeters. The size of raindrops is influenced by factors such as the strength of the updrafts within the cloud, the collision and coalescence of water droplets, and the presence of ice particles in the cloud. Size of Water Droplets Drizzle is characterized by its tiny water droplets, typically less than 0.5 millimeters in diameter. These droplets are much smaller than raindrops and contribute to the mist-like appearance of drizzle. The small size of the droplets allows them to remain suspended in the air for extended periods before they slowly descend to the ground. Visibility and Coverage Visibility During Drizzle Drizzle can significantly reduce visibility, mainly in dense fog or mist. The fine water droplets suspended in the air obstruct vision, making it difficult to see distant objects or landmarks. However, the reduced intensity of drizzle compared to heavier forms of precipitation often allows for better visibility compared to rain showers. Coverage of Drizzle Drizzle typically covers a wide geographic area due to the horizontal development of stratiform clouds. These clouds can extend over large regions, leading to widespread drizzle. However, the coverage of drizzle can be patchy within a given area, with some locations experiencing heavier drizzle than others. Visibility During Rain Showers During rain showers, visibility can be significantly reduced, especially if the showers are accompanied by heavy rain or thunderstorms. The intensity of the rain, combined with the potential presence of gusty winds and dark clouds, can lead to limited visibility. This reduced visibility can affect activities such as driving or outdoor navigation. Coverage of Rain Showers Rain showers can vary in coverage, ranging from localized to widespread precipitation. The coverage of rain showers depends on the size and movement of the weather system generating the showers. Small-scale convective processes often result in localized showers, while larger weather systems can produce widespread rainfall over extensive areas. Effect on Activities and Safety Effect on Outdoor Activities Drizzle can have a minor impact on outdoor activities. While light precipitation may not disrupt most activities, it can cause surfaces to become slippery and increase the risk of accidents. Additionally, drizzle can dampen outdoor spaces, making them less comfortable for certain recreational activities or gatherings. Safety Precautions During Drizzle During drizzle, it is advisable to wear appropriate clothing to protect against getting wet and to ensure comfort. Being cautious when walking or driving on potentially slippery surfaces is also important. Using umbrellas or raincoats can provide additional protection from moisture, while appropriate footwear can help prevent slips and falls. Effect on Outdoor Activities Rain showers, incredibly intense, can significantly impact outdoor activities. Heavy rainfall can limit the feasibility of specific outdoor pursuits, such as picnics, sports, or other events. It can also affect the functionality and safety of outdoor equipment and facilities. Safety Precautions During Rain Showers During rain showers, it is essential to seek shelter to avoid getting wet and to prevent potential hazards associated with thunderstorms or gusty winds. If outdoor activities are planned, it is advisable to monitor weather forecasts and have a backup plan in case of rain. When caught in a rain shower, using appropriate rain gear and waterproof clothing can help maintain comfort and minimize exposure to moisture. Impact on Agriculture and Environment Effect of Drizzle on Agriculture Drizzle is crucial in providing moisture to crops, especially during dry periods. It helps in replenishing soil moisture and supporting plant growth. However, prolonged drizzle can also lead to excessive soil moisture, which can adversely affect certain crops, promote the growth of fungi or diseases, and delay necessary agricultural activities such as planting or harvesting. Effect of Drizzle on the Environment Drizzle contributes to the overall water cycle and helps maintain the ecological balance. It provides hydration to plants, replenishes water sources such as rivers and lakes, and supports the survival of various ecosystems. Drizzle also aids in the removal of pollutants from the atmosphere, reducing air pollution levels and improving air quality. Effect of Rain Showers on Agriculture Rain showers significantly impact agriculture by providing much-needed moisture to crops. They help irrigate the soil, promote healthy plant growth, and ensure adequate water availability for agricultural activities. However, heavy rainfall associated with rain showers can also lead to soil erosion, waterlogging, and crop damage, resulting in agricultural losses. Effect of Rain Showers on the Environment Rain showers contribute to the overall environmental balance by providing water to ecosystems and maintaining the health of natural habitats. The runoff from rain showers replenishes water bodies, supports aquatic life, and helps sustain vegetation. Rain showers also help cleanse the atmosphere by washing away pollutants and enhancing air quality. Regions Prone to Drizzle Drizzle can occur in various regions worldwide but is widespread in coastal areas and regions influenced by maritime air masses. Locations with stable atmospheric conditions and persistent cloud cover, such as foggy regions or areas with a high prevalence of low-lying stratiform clouds, are more prone to experiencing drizzle. Regions Prone to Rain Showers Rain showers can occur in various regions and climates, from tropical rainforests to temperate zones. They are commonly associated with convective weather systems, which are more prevalent in areas experiencing frequent thunderstorms, frontal systems, or monsoon activity. Rain showers are often found in regions with a higher average annual precipitation. Forecasting and Meteorology Forecasting drizzle can be challenging due to its low intensity and localized nature. Meteorologists rely on various tools and techniques to predict the likelihood of drizzle. These include analyzing atmospheric moisture levels, cloud cover patterns, and atmospheric stability. Satellite imagery, weather radar, and weather models are commonly used to track the movement and evolution of cloud systems associated with drizzle. Forecasting Rain Showers Rain showers are typically part of a more extensive weather system, making their forecasting slightly more predictable. Meteorologists use similar tools and techniques for drizzling but with additional considerations for the dynamics of the weather system. They analyze factors such as a frontal boundary, atmospheric moisture content, wind patterns, and convection instability to forecast the occurrence and intensity of rain showers. Meteorological Tools and Techniques Meteorologists utilize various tools and techniques to study and forecast drizzle and rain showers. These include weather radar, which provides information on precipitation intensity and movement; satellite imagery for monitoring cloud cover and weather systems; weather stations for collecting meteorological data; and computer models that simulate atmospheric conditions. These tools, combined with meteorologists’ expertise, help improve the accuracy of weather forecasts. Drizzle and rain showers are both forms of precipitation but differ in intensity, size of water droplets, and atmospheric conditions that generate them. Drizzle consists of tiny, slow-falling water droplets and occurs in stable atmospheric conditions, while rain showers involve more giant, faster-falling raindrops and are associated with convective processes. Understanding the characteristics and effects of drizzle and rain showers is essential for various sectors, including agriculture, outdoor activities, and meteorology. By appreciating the nuances between drizzle and rain showers, we can better adapt and prepare for their impact on our daily lives and the environment.
When gray wolves were reintroduced to Yellowstone National Park, they sparked a resurgence of aspen trees. Young aspens had been devastated and all but disappeared, courtesy of elk, in what’s known as a trophic cascade — an ecological process that begins at the peak of the food chain and ripples downward. At Yellowstone, that particular cascade goes from wolves to elk to aspen. The absence of the wolves, an apex predator, had triggered the process. Their return began to unwind it. Yellowstone is a classic — but not singular — example of a predator-initiated trophic cascade. Other catalysts exist, including infectious agents such as parasites and pathogens. And that’s where UC Santa Barbara National Science Foundation postdoctoral research fellow Julia Buck comes in. Parasites and pathogens are her specialty. After a chance meeting at UC Santa Barbara with co-author William Ripple of Oregon State University, who described trophic cascades in Yellowstone soon after the wolves were reintroduced, Buck surveyed the literature for studies of cascades initiated by parasites and pathogens. She curated 47 examples and categorized them into three different types, including a new paradigm not applicable to predator-prey cascades. The findings appear in the journal Trends in Ecology & Evolution. “Our analysis found a hybrid type of indirect effect,” Buck said. “The wolves initiated a consumptive density-mediated indirect effect on aspen by reducing the population of elk. They also caused a nonconsumptive trait-mediated indirect effect by scaring the elk so the ruminants ate less, which also contributed to tree recovery. But because infectious agents can be less than fully and immediately lethal, they can simultaneously consume their hosts and change their behavior, initiating what we call a consumptive trait-mediated indirect effect.” Buck found this new category applied to 45 percent of the infectious agent case studies she discovered in her review. Case in point: larval trematodes — parasitic flatworms — that infect snails. Once infected, the snails lose their appetite and reduce their grazing, which in turn permits algae to flourish. “I found three trematode-snail-algae cascades; in one case, infected snails ate less algae than their uninfected counterparts, and in two cases, they ate more,” Buck explained. “One of the insights from this paper is that the effects can go both ways.” By far, the most prevalent category was density-mediated cascade, in which the consumer kills its victim. One such example is rinderpest, a virus that infects wildebeest in Africa’s Serengeti. The pathogen controls the wildebeest population, thereby benefiting the grasses they eat. “We only found out about this trophic cascade when rinderpest was eliminated from the population,” Buck explained. “Then wildebeest populations exploded and devastated the grasses. This led to other effects like fewer fires and more trees. We call these knock-on effects because they spin off from the main chain.” Fear-based effects were rare, but Buck found a couple of case studies. Phorid flies, for instance, need not infect their ant hosts to affect their behavior. Merely buzzing around the industrious insects causes panic and a reduction in appetite. As a result, the bugs the ants would otherwise consume are spared. Certain trophic cascades can begin with a predator or an infectious agent. Take sea urchins, for example. Sea otters feast on urchins, which in turn allows kelp to thrive; similarly, a bacterial pathogen can control sea urchins, which also benefits kelp. “Near the northern Channel Islands in California, predators like sea otters and lobsters were once common but are now scarce, thanks to extirpation and overfishing. Their prey — sea urchins — became so dense that in the early 1990s a bacterial pathogen caused an epidemic among sea urchins that benefited kelp,” Buck noted. “This is a good example of a predator-induced cascade being replaced by a pathogen-induced cascade. “Even though hundreds of cases of predator-induced cascades have been demonstrated, top-down regulation by parasites is probably more common because parasites are the most common consumers on Earth,” she added. “As we continue to lose top predators from ecosystems, we might see this kind of replacement more often.”
Why do homophones seem to get all the attention? A homophone, as you probably know, is a word that sounds the same as another word, but with a different meaning or spelling. For example, their, they’re and there. Or no and know. But do you know what a homograph is? A homograph is a word that looks the same, but has different meaning and perhaps different pronunciation. Here is a sentence that uses the homograph “dove.” The dove looked elegant as it dove underneath the tree branch to catch the bug. Here is a sentence that uses the homograph “bank.” After swimming at the river bank, we went to the bank to get some money to buy ice cream. Some more examples of homographs are bow, book, subject, duck, wound, tear, contract, and model. There are many more!!! In the comment section below, write a sentence using a homograph with both of its meanings like I did in the examples above. For an EXTRA challenge, write a sentence that uses two homographs with both of their meanings. If you enjoyed this reading enrichment, take a look at Reading Enrichment #10 which is also about homographs.
Amblyopia, commonly known as "lazy eye", is a visual disorder affecting as many as 2 or 3 percent of children under the age of six. Children with amblyopia experience significant vision loss in one eye, causing a loss of stereoscopic vision and possible blindness in the affected eye. It is not a condition that can be treated with eyeglasses or other traditional corrective methods. Amblyopic children may have two relatively healthy eyes, but the connection between one of those eyes and the brain did not fully develop during early childhood. Many people mistake the symptoms of amblyopia with another disorder called strabismus (an involuntary crossing of the eyes). If a child has a form of strabismus in which one eye remains misaligned continuously, then he or she could also develop amblyopia as a result. But many amblyopic children have normal eye alignments, so parents and family practitioners may not recognize all of the symptoms. Only an examination by a qualified pediatric eye doctor can reveal the presence of true amblyopia. Treatment of amblyopia depends on the age of the patient and the severity of the affliction. Since the unaffected eye becomes so dominant, most treatment programs involve forcing the other eye to take over the visual chores for a while. Amblyopic children may have to wear patches over the dominant eye or use atropine drops to cause blurriness. These methods force the affected eye to strengthen its connection with the visual cortex. Sometimes surgery may be performed to correct strabismus, but amblyopic symptoms may continue without therapy. If the affected eye does restrengthen its connection with the brain's visual cortex, then the child can be fitted for prescription glasses if necessary. One common cause of amblyopia is a significant difference in the visual acuity of each eye. The brain chooses to process information from the eye with the least amount of distortion. Treatment of amblyopia in older children or adults has not always been as successful, since the brain becomes very comfortable with the images produced by the 'good eye' over time. Early diagnosis and treatment, therefore, is very important for the child and his or her parents.
What is an Excel IF Statement? The Excel IF Statement tests a given condition and returns one value for a TRUE result and another value for a FALSE result. For example, if sales total more than $5,000, then return a “Yes” for Bonus – Otherwise, return a “No” for Bonus. We can also use the IF function to evaluate a single function, or we can include several IF functions in one formula. Multiple IF statements in Excel are known as nested IF statements. As a financial analyst, the IF function is used often to evaluate and analyze data by evaluating specific conditions. The function can be used to evaluate text, values, and even errors. It is not limited to only checking if one thing is equal to another and returning a single result. We can also use mathematical operators and perform additional calculations, depending on our criteria. We can also nest multiple IF functions together to perform multiple comparisons. =IF(logical_test, value_if_true, value_if_false) The function uses the following arguments: - Logical_test (required argument) – This is the condition to be tested and evaluated as either TRUE or FALSE. - Value_if_true (optional argument) – The value that will be returned if the logical_test evaluates to TRUE. - Value_if_false (optional argument) – The value that will be returned if the logical_test evaluates to FALSE. When using the IF function to construct a test, we can use the following logical operators: - = (equal to) - > (greater than) - >= (greater than or equal to) - < (less than) - <= (less than or equal to) - <> (not equal to) How to use the Excel IF Function To understand the uses of the Excel IF statement function, let’s consider a few examples: Example 1 – Simple Excel IF Statement Suppose we wish to do a very simple test. We want to test if the value in cell C2 is greater than or equal to the value in cell D2. If the argument is true, then we want to return some text stating “Yes it is”, and if it’s not true, then we want to display “No it isn’t”. You can see exactly how the Excel IF statement works in the simple example below. Result when true: Result when false: Example 2 – Excel IF Statement Suppose we wish to test a cell and ensure that an action is taken if the cell is not blank. We are given the data below: In the worksheet above, we listed AGM-related tasks in Column A. Remarks contain the date of completion. In Column B, we will use a formula to check if the cells in Column C are empty or not. If a cell is blank, the formula will assign the status “open.” However, if a cell contains a date, then the formula will assign a status of “closed.” The formula used is: We get the results below: Example 3 – Excel IF Statement Sellers frequently provide a discount based on the quantity purchased. Suppose we are given the following data: Using multiple IF functions, we can create a formula to check multiple conditions and perform different calculations depending on what amount range the specified quantity falls in. To calculate the total price for 100 items, the formula will be: We get the result below: Things to remember about the IF Function - The Excel IF function will work if the logical_test returns a numeric value. In such a case, any non-zero value is treated as TRUE and zero is treated as FALSE. - #VALUE! error – Occurs when the given logical_test argument cannot be evaluated as TRUE or FALSE. - When any of the arguments are provided to the function as arrays, the IF function will evaluate every element of the array. - If we wish to count conditions, we should use the COUNTIF and COUNTIFS functions. - If we wish to add up conditions, we should use the SUMIF and SUMIFS functions. Reasons to use an Excel IF Statement There are many reasons why an analyst or anyone who uses Excel would want to build IF formulas. Common examples include: - To test if an argument is true or false - To output a NUMBER - To output some TEXT - To generate a conditional formula (e.g., the result is C3+B4 if true and N9-E5 if false) - To create scenarios to be used in financial modeling - To calculate a debt schedule or a fixed asset depreciation schedule in accounting Thanks for reading CFI’s guide on how to use an Excel IF Statement. By taking the time to learn and master these functions, you’ll significantly speed up your financial analysis. To learn more, check out these additional CFI resources:
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8th Grade Global Studies Syllabus 8A: Kirsten Croone email: email@example.com 8B: Elizabeth Sutherland email: firstname.lastname@example.org Phone Number: 651-293-8830 Students will actively engage in the work of a geographer by asking geographic questions and then acquiring, organizing, analyzing, and interpreting geographic information in order to answer geographic questions. This course will use a regional approach to explore the 6 essential elements of Geography: Places and Regions, Physical Systems, Human Systems, Environments and Society, The Spatial World and Uses of Geography in Today’s Society. The content will incorporate a variety of scales – from local to global. Classroom materials will include adopted instructional materials and supplementary printed and electronic resources. Expectations for students - Participate in class discussions - Participate and contribute to group work - Complete homework and class assignments Daily required materials - a pen or pencil (sharpened before class) - Social Studies materials - your 3 ring binder including your planner Guiding Questions of Geography: - How do geographers organize information about the Earth? - Where are things located? - Why are they located there? - How does the environment influence human activities? - How do humans interact with and impact their environment? - What are the physical and human characteristics of places? - How does the movement of people affect place and culture? - How are places interconnected and how are those connections changing? Standards and Benchmarks: The student will use maps, globes, geographic information systems and other sources of information to analyze the natures of places at a variety of scales Maps and Globe The student will use maps and globes to demonstrate specific and increasingly complex geographic knowledge The student will make and use maps to acquire, process, and report on the spatial organization of people and places on Earth. Physical Features and Processes The student will identify physical characteristics of places and use this knowledge to define regions, their relationships among regions, and their patterns of change. The student will give examples that demonstrate how people are connectedto each other and the environment. The student will describe how humans influence the environment and in turn are influenced by it. The student will demonstrate how various regional frameworks are used to analyze the variation in culture and human occupation of the Earth’s surface. Scope and Sequence This course will use a regional approach and study the following thematic topics within each regional unit: physical and human systems, land use and resources, population and migration, industry and economic development. Canada and US Africa South of the Sahara Southwest Asia and North Africa East Asia and Southeast Asia Model United Nations South Asia and Central Asia Content-based Instructional Practices (Habits of Thinking) To think like a geographer students need these habits of thinking: - Recognize spatial patterns. - Use maps and other geographical tools (globes, atlases, tables, charts, graphs, documents) to acquire, analyze, organize and report information. - Use mental maps to organize and analyze information about people, places, and environments. - Apply geography to interpret the past, the present, and plan for the future. - Analyze and interpret information obtained from maps, aerial photographs, satellite produced images, and geographic information systems - Prepare various forms of maps, graphs, diagrams, table, or charts to organize and display geographic information E-mail us at:
Surface Tension by Anna Christiansen Cable 3rd Place - Natural Category School: Evanston Township High School Teacher: Daniel DuBrow This insect is able to stay on top of the water because of a physics property called surface tension. This allows more dense objects, like the insect, to stay on top of substances with a lower density, like the water. Water molecules that are not on the surface are surrounded on all sides by other water molecules, and they are attracted to each other. On the other hand, water molecules that are on the surface are not surrounded on all sides. Each molecular attraction causes the molecules to have less potential energy, which results in the molecules at the surface to have a higher potential energy than the ones underwater. In order for the surface area to increase, water molecules that are not on the surface must be pushed to the surface, but because they have a lower potential energy, this requires a certain amount of energy to do. If the object on top of the water does not have enough energy to increase the surface area, than the object will not sink, just like the insect in the picture.
CRETE (Crēt) Long, narrow, mountainous island south of mainland Greece, running 170 miles east-west but never more than about 35 miles wide. Crete was the center of the Minoan maritime empire named after the legendary King Minos and associated especially with the famous palaces of Knossos and Phaestos, which flourished from 2000 to 1500 b.c. This artistically brilliant civilization fell suddenly, perhaps by earthquake followed by conquest, about 1400 b.c., leaving written tablets in the oldest known scripts of Europe, including the undeciphered “Linear A” and the apparently later proto-Greek “Linear B,” found also on the mainland. The Minoans of Crete were known to the Egyptians as “Keftiu,” which may be the same as biblical “Caphtor,” though the biblical term may include a wider reference to coastlands and islands of the Aegean area. The Philistines came to Palestine from Caphtor (Jer. 47:4; Amos 9:7) and may have been part of the widespread migrant “Sea Peoples” rather than Cretans proper. In classical Greek times Crete had many city-states, but they played relatively little part in mainstream Greek history. It had become a center of piracy before the Roman occupation in 67 b.c. Under the Romans it became part of a double province, Crete with Cyrene, under a governor with the title “proconsul,” who ruled the island and the opposite coast of North Africa from the Roman capital Gortyna. This had already been among the cities to whom the Romans had appealed a century before for fair treatment of their Jewish minorities (1 Macc. 15:23). Cretans were among those listed as present in Jerusalem on the day of Pentecost (Acts 2:11), and the gospel may first have reached the island through them. Paul made his voyage to Rome as a prisoner on a Roman grain ship. The voyage followed the route south of Crete, which gave partial shelter from the northwest winds and avoided the peril of the lee shore on the north coast, while still involving the need to beat against largely adverse winds. The journey had already been very slow, and it was getting dangerously late in the summer sailing season. The ship doubled Salmone, the eastern cape of Crete, and with difficulty reached Fair Havens, a small anchorage near the city of Lasea (Acts 27:8). There the emergency council called by the centurion and shipmaster overruled Paul’s advice, and a risky attempt was made to reach Phoenix, a regular port for servicing the grain ships, some 40 miles further west along the coast. The gentle south wind gave way to a violent northeaster (Euroclydon, Acts 27:14) when they came out of the shelter of Cape Matala (Loukinos) into an open bay, and the ship was driven helplessly, managing only some emergency action in the lee of the offshore island of Cauda, and thence to shipwreck on Malta. The only other references to Crete in the NT are in the epistle to Titus. Paul had left Titus in Crete to exercise pastoral supervision over the churches there (Titus 1:5). The character of the people is described in a quotation from a prophet of their own: “Cretans are always liars, evil beasts, lazy gluttons” (Titus 1:12 HCSB), words attributed to the Cretan seer Epimenides, who was also credited with having advised the Athenians to set up altars to unknown gods (cp. Acts 17:23). It is a problem to know when Paul (or Titus) visited Crete, apart from Paul’s voyage as a prisoner. It is difficult to fit the occasions of the Pastoral Epistles (to Timothy and Titus) into Paul’s life as recorded in Acts. The most satisfactory answer to this difficulty still seems to be that which argues that Paul was released from his two years’ imprisonment in Rome (Acts 28:30) and undertook further travels in the East which can only be traced in these epistles. At this last period of his life he may have focused his work on establishing and strengthening the churches throughout the Greek East. Because of its location and its relative fertility, Crete has been a prize of war and of commerce. The island was conquered by Rome in 67 bc and became a separate province. The inhabitants prospered under the Romans and later under the Greek Christians (Byzantines). The Saracens (Muslims) occupied the island for over a century (ad 823–960). After centuries of Christian leadership, it was conquered by the Turkish sultan, and civilization languished (1669–1898). In the 20th century Crete has been a part of Greece, except for a period of German occupancy during World War II.
The mid-1930s was the era when the popular front and the communism were the home of writers and radical artists, who thought that it was needless to divorce art from the political realities. The assertion insinuated that abstract art was untenable since it was purist and political. By referring to the then art as ‘purist,’ one possibly implied that art did not address the social issues exclusively. Further, nearing the end of the 1930s, a group of artists and writers argued that all the base of art was in its producing conditions; hence, there was the high likelihood of art having more social relevance than its initial perception. History of the modern art has evacuated the historical meanings of the term avant-garde, using it to represent the development of art and the role of artists in the society. By using art to reject the intimidation of nature for communicating his personal response to the world, Gaiger uses the term ‘avant-garde.’ He says that when the writers and artists can no longer bank on communicating with their audience, then their responses freeze in academic neo-classicism. The artist develops his ideas on avant-garde prior to the existence of abstract expressionism. The idea of expressionism is also developed from the art of Jackson Pollock, which when merged with avant-garde lose the political thrust over time. Based on the theory of Matisse, focusing on the perfect results to abstraction concerning expressionism. The sentiment suggests that the artist is merely imitating the art’s process since art in itself, is an imitation in the manner of its inception.
You want a paper aeroplane to do more than just fall gradually through air. You want it to move ahead. You Origami Flower make a paper aeroplane move forward by throwing it. Usually the harder you throw a paper aeroplane the further it will fly. Typically the forward movement of an be airborne is called thrust Thrust helps to give an aeroplane lift. Here's how. Hold one end of a sheet of paper and move it quickly through the environment. The smooth sheet hits against the air in its path. The air pushes up the free part of the moving paper. The paper aeroplane must undertake the air so that it can stay upward for longer flights. Here's how you can see and feel what happens when air pushes. Spot a Bateau Pliage Papier Origami sheet of papers flat against the hands of your upturned hand. Turn your hand over and push down quickly. You can go through the air pressing against the paper. The paper stays in place against your palm. You can see the paper's edges pushed back again by the air. Right now hold a piece of crumpled paper in your palm. Again turn your hand over and push down. Small surface of the paper hits less air. You feel less of a push against your hand. Unless you push down rapidly, the paper will tumble to the ground before your hand reaches the ground. Air is a real substance Bateau De Papier Jean Humenry even though you can't see it. A new flat sheet of paper falling downwards pushes against the air in the path. The air shoves back from the paper and slows its fall. A crumpled piece of paper has a smaller surface pushing against the air. The air doesn't push back as strongly just like the smooth piece, and the golf ball of paper falls faster. The spread-out wings of a paper aeroplane keep it from falling quickly down to the floor. We the wings give a plane lift. The particular secret lies in the form of the wing. The front edge of an aeroplane's wing is more rounded Which paper falls to the ground first? What seems to keep the smooth sheet from falling quickly? We live with air all around us. Our planet world is surrounded by a layer of air called the atmosphere. The atmosphere expands hundreds of miles above the surface of the world. Take two sheets of the same-sized paper. Crumple one of the papers into a ball. Hold the crumpled paper and the toned paper high above the head. Drop them both at the same time. The force of gravity pulls them both downward. Have you ever flown a paper aeroplane? Sometimes it twists and loops through Bateau Papier Pliage Facile the air and then comes to red, smooth as a feather. Some other times a paper rudder climbs straight up, flips over, and dives headfirst into the ground. What maintains a paper aeroplane in the air? How will you make a paper aeroplane require a00 long flight) How can you make it loop or turn! Does flying a document aeroplane on a blowy, gusty, squally, bracing, turbulent day help it to stay aloft? What can you learn about real aeroplanes by making and flying paper aeroplanes? Let's experiment to discover some of the answers. The particular Paper Aeroplane Book Why is paper aeroplanes soar and plummet, loop and float? Comment Faire Un Avion En Papier Qui Vole Bien Longtemps Why do they travel whatsoever? This book will show you how to make them and clarifies why they do things they do. Making paper eeroplanes is fun and. using the author's stepby- step instructions and doing the simple experiments he indicates, you will also discover what makes a real aeroplane travel. As you make and fly paper planes of various Designs, you will learn about lift, thrust, drag and gravity; you will see how wing size and ships and fuselage weight and balance impact the lift of a aircraft: how ailerons, alleviators and the rudder work to make a plane diva or climb. loop or glide, roll Avion En Papier Qui Vole Bien Facile A Faire or spin and rewrite. Once you have appreciated these principles of flight, you may be ready to take off with types of your own. Clear diagrams and delightful drawings show each step for making the aeroplanes and illustrate the experiments suggested by the author. The front edges of the wings of any real rudder are usually tilted somewhat upwards. Just like a kite, the air pushes against the tilted underside of the wings, giving the airplane lift. The greater the angle of the tilt a lot more wing surface the air pushes against. This results in a greater amount of lift. But if the angle of the tilt is actually great, the air pushes from the larger wing surface presented and slows down the forwards movement of the airplane. This is called drag. Drag works to slow a aircraft down, as thrust works to ensure it is move forward. At the same time, lift works to make a plane go up, as gravity tries to make it drop. These four forces are working on paper aeroplanes just as they work on real aeroplanes. There is still another way most real aeroplanes and some paper aeroplanes use their wings to increase lift. The top-side as well since the base side of the wing can help to give the plane lift.
A Singer’s diction must have 2 main components It must be easy to understand and Be pleasant to listen to To be easily understood we need good open vowel production. Open tone or open vowel production is dependent on a particular way of creating your vowel sounds. The back parts of the mouth all react to make different shapes which turn the phonated or unphonated breath stream into voiced or unvoiced sounds. This calls for great flexibility of this part of the vocal mechanism. This flexibility is dependent on the “forward-in-the-masque” Use the two affricates, the ch in “church” and the sh in “sheep”, and the consonant^ as in “judge” to establish an open puckered position of the lips. Repeat the following words: Sheep; judge; church. Use large mirror or small hand mirror to observe the form or shape of the lips. This lip position can be described as an open square or a bell shape or as a small megaphone. Sustain the following tone syllables on one pitch, using care not to re lax the open position of the lips: Jah – jay – jo Chee – chay – cho Shee – shay – sho Conclusion: The elimination of the use of the lips through the open-square position tends to bring in an enunciation of the vowel sounds by the pharynx as well as a forward-in-the-masque illusion of “nasal resonance.”
Showing your children the application of maths in everyday life Take a look around the average home, school or outside environment and you'll quickly come to notice that numbers are everywhere. From the hours and minutes that are displayed on a clock face to the sequences of numbers on a car number plate, there are a multitude of opportunities for children to apply their mathematics skills to everyday contexts. Children make their first connection to numbers as they count the number of seconds before they hunt for a friend in a game of hide and seek, or play hopscotch on numbered squares in the school playground. Counting, estimating, adding and subtracting are skills that the average child may use several times in any given day. Take the process of filling a packed lunch box as an example. As children fill their boxes with sandwiches and healthy treats, they are estimating the number of items that will fit into the space and depth of the box. As they eat lunch later that day they may count out the number of raisins in their fruit box or decide that they will save half the amount of raisins to eat after school. Showing children where and when to utilise their maths skills is something that can be incorporated into the normal family routine, such as the examples below: A trip to the supermarket Taking children to the local supermarket provides a wealth of opportunities for children to use their mathematical knowledge, as well as giving them the chance to learn new skills. Looking at price labels, calculating the percentage discounts of reduced items and handling money and calculating change at the checkout can all contribute to children's mathematical learning. Cooking at home Working through simple recipes such as making shortbread biscuits can utilise a number of mathematical skills. Choose a recipe that produces a smaller amount than the number of people in your family, such as four biscuits for a family of 8. Ask children to re-write the recipe by doubling or halving amounts. Children can also weigh out ingredients to the appropriate amounts and look at the varying increments on a weighing scale. Counting numbers on a journey Children can go for a number hunt on car journeys, on their daily walk or even just around the house to make the connection that understanding numbers helps them to understand the world around them. Once children have recorded the numbers, you could ask them questions such as 'how many pairs of shoes are there in the shoe rack?' This will encourage children to utilise unique skills such as counting in twos.
\|PL/SQL User's Guide and Reference 10g Release 1 (10.1) Part Number B10807-01 LOOP statements execute a sequence of statements multiple times. The LOOP and END LOOP keywords enclose the statements. PL/SQL provides four kinds of loop statements: basic loop, FOR loop, and cursor FOR loop. For usage information, see "Controlling Loop Iterations: LOOP and EXIT Statements". Keyword and Parameter Description A loop that executes an unlimited number of times. It encloses a sequence of statements between the keywords LOOP. With each iteration, the sequence of statements is executed, then control resumes at the top of the loop. An RAISE statement branches out of the loop. A raised exception also ends the loop. An expression that returns the Boolean value NULL. It is associated with a sequence of statements, which is executed only if the expression returns TRUE. For the syntax of boolean_expression, see "Expressions". Issues a SQL query and loops through the rows in the result set. This is a convenient technique that makes processing a query as simple as reading lines of text in other programming languages. FOR loop implicitly declares its loop index as a %ROWTYPE record, opens a cursor, repeatedly fetches rows of values from the result set into fields in the record, and closes the cursor when all rows have been processed. An explicit cursor previously declared within the current scope. When the cursor FOR loop is entered, cursor_name cannot refer to a cursor already opened by an OPEN statement or an enclosing cursor A variable declared as the formal parameter of a cursor. (For the syntax of cursor_parameter_declaration, see "Cursors".) A cursor parameter can appear in a query wherever a constant can appear. The formal parameters of a cursor must be FOR loops iterate over a specified range of integers. The range is part of an iteration scheme, which is enclosed by the keywords The range is evaluated when the FOR loop is first entered and is never re-evaluated. The loop body is executed once for each integer in the range defined by lower_bound..upper_bound. After each iteration, the loop index is incremented. An undeclared identifier that names the loop index (sometimes called a loop counter). Its scope is the loop itself; you cannot reference the index outside the loop. The implicit declaration of index_name overrides any other declaration outside the loop. To refer to another variable with the same name, use a label: <<main>> DECLARE num NUMBER; BEGIN ... FOR num IN 1..10 LOOP IF main.num > 5 THEN -- refers to the variable num, ... -- not to the loop index END IF; END LOOP; END main; Inside a loop, the index is treated like a constant: it can appear in expressions, but cannot be assigned a value. An optional undeclared identifier that labels a loop. label_name must be enclosed by double angle brackets and must appear at the beginning of the loop. Optionally, label_name (not enclosed in angle brackets) can also appear at the end of the loop. You can use label_name in an EXIT statement to exit the loop labelled by label_name. You can exit not only the current loop, but any enclosing loop. You cannot reference the index of a FOR loop from a nested FOR loop if both indexes have the same name, unless the outer loop is labeled by label_name and you use dot notation: The following example compares two loop indexes that have the same name, one used by an enclosing loop, the other by a nested loop: <<outer>> FOR ctr IN 1..20 LOOP ... <<inner>> FOR ctr IN 1..10 LOOP IF outer.ctr > ctr THEN ... END LOOP inner; END LOOP outer; Expressions that return numbers. (Otherwise, PL/SQL raises the predefined exception VALUE_ERROR.) The expressions are evaluated only when the loop is first entered. The lower bound need not be 1, as the example below shows. The loop counter increment (or decrement) must be 1. FOR i IN -5..10 LOOP ... END LOOP; Internally, PL/SQL assigns the values of the bounds to temporary PLS_INTEGER variables, and, if necessary, rounds the values to the nearest integer. The magnitude range of a 2*31. If a bound evaluates to a number outside that range, you get a numeric overflow error when PL/SQL attempts the assignment. By default, the loop index is assigned the value of lower_bound. If that value is not greater than the value of upper_bound, the sequence of statements in the loop is executed, then the index is incremented. If the value of the index is still not greater than the value of upper_bound, the sequence of statements is executed again. This process repeats until the value of the index is greater than the value of upper_bound. At that point, the loop completes. An implicitly declared record. The record has the same structure as a row retrieved by The record is defined only inside the loop. You cannot refer to its fields outside the loop. The implicit declaration of record_name overrides any other declaration outside the loop. You cannot refer to another record with the same name inside the loop unless you qualify the reference using a block label. Fields in the record store column values from the implicitly fetched row. The fields have the same names and datatypes as their corresponding columns. To access field values, you use dot notation, as follows: Select-items fetched from the FOR loop cursor must have simple names or, if they are expressions, must have aliases. In the following example, wages is an alias for the select item CURSOR c1 IS SELECT empno, sal+comm wages, job ... By default, iteration proceeds upward from the lower bound to the upper bound. If you use the keyword REVERSE, iteration proceeds downward from the upper bound to the lower bound. An example follows: FOR i IN REVERSE 1..10 LOOP -- i starts at 10, ends at 1 -- statements here execute 10 times END LOOP; The loop index is assigned the value of upper_bound. If that value is not less than the value of lower_bound, the sequence of statements in the loop is executed, then the index is decremented. If the value of the index is still not less than the value of lower_bound, the sequence of statements is executed again. This process repeats until the value of the index is less than the value of lower_bound. At that point, the loop completes. A query associated with an internal cursor unavailable to you. Its syntax is like that of select_into_statement without the INTO clause. See "SELECT INTO Statement". PL/SQL automatically declares, opens, fetches from, and closes the internal cursor. Because select_statement is not an independent statement, the implicit cursor SQL does not apply to it. WHILE-LOOP statement associates a Boolean expression with a sequence of statements enclosed by the keywords LOOP. Before each iteration of the loop, the expression is evaluated. If the expression returns TRUE, the sequence of statements is executed, then control resumes at the top of the loop. If the expression returns NULL, the loop is bypassed and control passes to the next statement. You can use the WHEN statement to exit any loop prematurely. If the Boolean expression in the WHEN clause returns TRUE, the loop is exited immediately. When you exit a cursor FOR loop, the cursor is closed automatically even if you use an GOTO statement to exit the loop prematurely. The cursor is also closed automatically if an exception is raised inside the loop. The following cursor FOR loop calculates a bonus, then inserts the result into a database table: DECLARE bonus REAL; CURSOR c1 IS SELECT empno, sal, comm FROM emp; BEGIN FOR c1rec IN c1 LOOP bonus := (c1rec.sal 0.05) + (c1rec.comm * 0.25); INSERT INTO bonuses VALUES (c1rec.empno, bonus); END LOOP; COMMIT; END;
HIV - AIDS Human immunodeficiency virus or HIV is a retrovirus that causes Acquired Immunodeficiency Syndrome (AIDS), a condition in which the immune system begins to fail, leading to life-threatening opportunistic infections. Previous names for the virus include Human T-Lymphotropic Virus-III (HTLV-III) and lymphadenopathy-associated virus (LAV). Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, Cowper's fluid or breast milk. Within these body fluids HIV is present as both free virus particles and virus within infected immune cells. The three major routes of transmission are unprotected sexual intercourse, contaminated needles and transmission from an infected mother to her baby at birth or through breast milk. Screening of blood products for HIV in the developed world has largely eliminated transmission through blood transfusions or infected blood products in these countries. HIV infection in humans is now pandemic. As of January 2006, the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) estimate that AIDS has killed more than 25 million people since it was first recognized on December 1, 1981, making it one of the most destructive pandemics in recorded history. In 2005 alone, AIDS claimed an estimated 2.4-3.3 million lives, of which more than 570,000 were children. A third of these deaths are occurring in sub-Saharan Africa, retarding economic growth and increasing poverty. According to current estimates, HIV is set to infect 90 million people in Africa, resulting in a minimum estimate of 18 million orphans. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but routine access to antiretroviral medication is not available in all countries. HIV primarily infects vital cells in the human immune system such as helper T cells (specifically CD4+ T cells), macrophages and dendritic cells. HIV infection leads to low levels of CD4+ T cells through three main mechanisms: firstly, direct viral killing of infected cells; secondly, increased rates of apoptosis in infected cells; and thirdly, killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes that recognize infected cells. When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections. If untreated, eventually most HIV-infected individuals develop AIDS and die; however about one in ten remain healthy for many years, with no noticeable symptoms. Treatment with anti-retrovirals, where available, increases the life expectancy of people infected with HIV. It is hoped that current and future treatments may allow HIV-infected individuals to achieve a life expectancy approaching that of the general public (see Treatment). Origin and discovery The AIDS epidemic was discovered June 5, 1981, when the U.S. Centers for Disease Control and Prevention reported a cluster of Pneumocystis carinii pneumonia (now classified as Pneumocystis jiroveci pneumonia) in five homosexual men in Los Angeles. The disease was originally dubbed GRID, or Gay-Related Immune Deficiency, but health authorities soon realized that nearly half of the people identified with the syndrome were not homosexual men. In 1982, the CDC introduced the term AIDS to describe the newly recognized syndrome, though it was still casually referred to as GRID. In 1983, scientists led by Luc Montagnier at the Pasteur Institute in France first discovered the virus that causes AIDS. They called it lymphadenopathy-associated virus (LAV). A year later a team led by Robert Gallo of the United States confirmed the discovery of the virus, but they renamed it human T lymphotropic virus type III (HTLV-III). The dual discovery led to considerable scientific disagreement, and it was not until President Mitterrand of France and President Reagan of the USA met that the major issues were resolved. In 1986, both the French and the US names for the virus itself were dropped in favour of the new term, human immunodeficiency virus (HIV). HIV was classified as a member of the genus lentivirus, part of the family of retroviridae. Lentiviruses have many common morphologies and biological properties. Many species are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long incubation period. Lentiviruses are transmitted as single-stranded, positive-sense, enveloped RNA viruses. Upon entry of the target cell, the viral RNA genome is converted to double-stranded DNA by a virally encoded reverse transcriptase that is present in the virus particle. This viral DNA is then integrated into the cellular DNA by a virally encoded integrase so that the genome can be transcribed. Once the virus has infected the cell, two pathways are possible: either the virus becomes latent and the infected cell continues to function, or the virus becomes active and replicates, and a large number of virus particles are liberated that can then infect other cells. Two species of HIV infect humans: HIV-1 and HIV-2. HIV-1 is thought to have originated in southern Cameroon after jumping from wild chimpanzees (Pan troglodytes troglodytes) to humans during the twentieth century. HIV-2 may have originated from the Sooty Mangabey (Cercocebus atys), an Old World monkey of Guinea-Bissau, Gabon, and Cameroon. HIV-1 is the most virulent. It is easily transmitted and is the cause of the majority of HIV infections globally. HIV-2 is less transmittable and is largely confined to West Africa. HIV-1 is the virus that was initially discovered and termed LAV. Three of the earliest known instances of HIV-1 infection are as follows: Although a variety of theories exist explaining the transfer of HIV to humans, no single hypothesis is widely accepted, and the topic remains controversial. Freelance journalist Tom Curtis discussed one controversial possibility for the origin of HIV/AIDS in a 1992 Rolling Stone magazine article. He put forward what is now known as the OPV AIDS hypothesis, which suggests that AIDS was inadvertently caused in the late 1950s in the Belgian Congo by Hilary Koprowski's research into a polio vaccine. Although subsequently retracted due to libel issues surrounding its claims, the Rolling Stone article motivated another freelance journalist, Edward Hooper, to probe more deeply into this subject. Hooper's research resulted in his publishing a 1999 book, The River, in which he alleged that an experimental oral polio vaccine prepared using chimpanzee kidney tissue was the route through which simian immunodeficiency virus (SIV) crossed into humans to become HIV, thus starting the human AIDS pandemic. This theory is contradicted by an analysis of genetic mutation in primate lentivirus strains that indicates with 95% certainty that the origin of the HIV-1 strain dates to about 1930. Since the beginning of the pandemic, three main transmission routes for HIV have been identified HIV-2 is transmitted much less frequently by the MTCT and sexual route than HIV-1. HIV has been found at low concentrations in the saliva, tears and urine of infected individuals, but the risk of transmission by these secretions is negligible. The use of physical barriers such as the latex condom is widely advocated to reduce the sexual transmission of HIV. Spermicide when used alone or with vaginal contraceptives like a diaphragm actually increases the male to female transmission rate due to inflammation of the vagina, and should not be considered a barrier to infection. Current research is clarifying the relationship between male circumcision and HIV in differing social and cultural contexts. Even though male circumcision may lead to a reduction of infection risk in heterosexual men by up to 60%, UNAIDS believes that it is premature to recommend male circumcision as part of HIV prevention programs. South African medical experts are concerned that the repeated use of unsterilized blades in the ritual circumcision of adolescent boys may be spreading HIV. Diagram of HIV Structure and genome HIV is different in structure from other retroviruses. It is about 120 nm in diameter (120 billionths of a meter; around 60 times smaller than a red blood cell) and roughly spherical. It is composed of two copies of positive single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein, p24. The single-stranded RNA is tightly bound to nucleocapsid proteins, p7 and enzymes needed for the development of the virion such as reverse transcriptase, proteases and integrase. A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion particle. This is, in turn, surrounded by the viral envelope which is composed of two layers of fatty molecules called phospholipids taken from the membrane of a human cell when a newly formed virus particle buds from the cell. Embedded in the viral envelope are proteins from the host cell and about 70 copies of a complex HIV protein that protrudes through the surface of the virus particle. This protein, known as Env, consists of a cap made of three molecules called glycoprotein (gp) 120, and a stem consisting of three gp41 molecules that anchor the structure into the viral envelope. This glycoprotein complex enables the virus to attach to and fuse with target cells to initiate the infectious cycle. Both these surface proteins, especially gp120, have been considered as targets of future treatments or vaccines against HIV. Of the nine genes that are encoded within the RNA genome, three of these genes, gag, pol, and env, contain information needed to make the structural proteins for new virus particles. env, for example, codes for a protein called gp160 that is broken down by a viral enzyme to form gp120 and gp41. The six remaining genes, tat, rev, nef, vif, vpr, and vpu (or vpx in the case of HIV-2), are regulatory genes for proteins that control the ability of HIV to infect cells, produce new copies of virus (replicate), or cause disease. The protein encoded by nef, for instance, appears necessary for the virus to replicate efficiently, and the vpu-encoded protein influences the release of new virus particles from infected cells. The ends of each strand of HIV RNA contain an RNA sequence called the long terminal repeat (LTR). Regions in the LTR act as switches to control production of new viruses and can be triggered by proteins from either HIV or the host cell. The term viral tropism refers to which cell types HIV infects. HIV can infect a variety of immune cells such as CD4+ T cells, macrophages, and microglial cells. HIV-1 entry to macrophages and CD4+ T cells is mediated through interaction of the virion envelope glycoproteins (gp120) with the CD4 molecule on the target cells and also with chemokine coreceptors. Macrophage (M-tropic) strains of HIV-1, or non-syncitia-inducing strains (NSI) use the β-chemokine receptor CCR5 for entry and are thus able to replicate in macrophages and CD4+ T cells. This CCR5 coreceptor is used by almost all primary HIV-1 isolates regardless of viral genetic subtype. Indeed, macrophages play a key role in several critical aspects of HIV infection. They appear to be the first cells infected by HIV and perhaps the source of HIV production when CD4+ cells become depleted in the patient. Macrophages and microglial cells are the cells infected by HIV in the central nervous system. In tonsils and adenoids of HIV-infected patients, macrophages fuse into multinucleated giant cells that produce huge amounts of virus. T-tropic isolates, or syncitia-inducing (SI) strains replicate in primary CD4+ T cells as well as in macrophages and use the α-chemokine receptor, CXCR4, for entry. The α-chemokine, SDF-1, a ligand for CXCR4, suppresses replication of T-tropic HIV-1 isolates. It does this by down-regulating the expression of CXCR4 on the surface of these cells. HIV that use only the CCR5 receptor are termed R5, those that only use CXCR4 are termed X4, and those that use both, X4R5. However, the use of coreceptor alone does not explain viral tropism, as not all R5 viruses are able to use CCR5 on macrophages for a productive infection and HIV can also infect a subtype of myeloid dendritic cells, which probably constitute a reservoir that maintains infection when CD4+ T cell numbers have declined to extremely low levels. Some people are resistant to certain strains of HIV. One example of how this occurs is people with the CCR5-Δ32 mutation; these people are resistant to infection with R5 virus as the mutation stops HIV from binding to this coreceptor, reducing its ability to infect target cells. Heterosexual intercourse is the major mode of HIV transmission. Both X4 and R5 HIV are present in the seminal fluid which is passed from partner to partner. The virions can then infect numerous cellular targets and disseminate into the whole organism. However, a selection process leads to a predominant transmission of the R5 virus through this pathway. How this selective process works is still under investigation, but one model is that spermatozoa may selectively carry R5 HIV as they possess both CCR3 and CCR5 but not CXCR4 on their surface and that genital epithelial cells preferentially sequester X4 virus. In patients infected with subtype B HIV-1, there is often a co-receptor switch in late-stage disease and T-tropic variants appear that can infect a variety of T cells through CXCR4. These variants then replicate more aggressively with heightened virulence that causes rapid T cell depletion, immune system collapse, and opportunistic infections that mark the advent of AIDS. Thus, during the course of infection, viral adaptation to the use of CXCR4 instead of CCR5 may be a key step in the progression to AIDS. A number of studies with subtype B-infected individuals have determined that between 40 and 50% of AIDS patients can harbour viruses of the SI, and presumably the X4, phenotype. Entry to the cell HIV enters macrophages and CD4+ T cells by the adsorption of glycoproteins on its surface to receptors on the target cell followed by fusion of the viral envelope with the cell membrane and the release of the HIV capsid into the cell. The interactions of the trimeric envelope complex (gp160 spike, discussed above) and both CD4 and a chemokine receptor (generally either CCR5 or CXCR4 but others are known to interact) on the cell surface. The gp160 spike contains binding domains for both CD4 and chemokine receptors. The first step in fusion involves the high-affinity attachment of the CD4 binding domains of gp120 to CD4. Once gp120 is bound with the CD4 protein, the envelope complex undergoes a structural change, exposing the chemokine binding domains of gp120 and allowing them to interact with the target chemokine receptor. This allows for a more stable two-pronged attachment, which allows the N-terminal fusion peptide gp41 to penetrate the cell membrane. Repeat sequences in gp41, HR1 and HR2 then interact, causing the collapse of the extracellular portion of gp41 into a hairpin. This loop structure brings the virus and cell membranes close together, allowing fusion of the membranes and subsequent entry of the viral capsid. Once HIV has bound to the target cell, the HIV RNA and various enzymes, including reverse transcriptase, integrase and protease, are injected into the cell. HIV can infect dendritic cells (DCs) by this CD4-CCR5 route, but another route using mannose-specific C-type lectin receptors such as DC-SIGN can also be used. DCs are one of the first cells encountered by the virus during sexual transmission. They are currently thought to play an important role by transmitting HIV to T cells once the virus has been captured in the mucosa by DCs. Replication and transcription Once the viral capsid enters the cell, an enzyme called reverse transcriptase liberates the single-stranded (+)RNA from the attached viral proteins and copies it into a complementary DNA of 9 kb size. This process of reverse transcription is extremely error-prone and it is during this step that mutations may occur. Such mutations may cause drug resistance. The reverse transcriptase then makes a complementary DNA strand to form a double-stranded viral DNA intermediate (vDNA). This vDNA is then transported into the cell nucleus. The integration of the viral DNA into the host cell's genome is carried out by another viral enzyme called integrase. This integrated viral DNA may then lie dormant, in the latent stage of HIV infection. To actively produce the virus, certain cellular transcription factors need to be present, the most important of which is NF-κB (NF kappa B), which is upregulated when T cells become activated. This means that those cells most likely to be killed by HIV are in fact those currently fighting infection. In this replication process, the integrated provirus is copied to mRNA which is then spliced into smaller pieces. These small pieces produce the regulatory proteins Tat (which encourages new virus production) and Rev. As Rev accumulates it gradually starts to inhibit mRNA splicing. At this stage, the structural proteins Gag and Env are produced from the full-length mRNA. The full-length RNA is actually the virus genome; it binds to the Gag protein and is packaged into new virus particles. HIV-1 and HIV-2 appear to package their RNA differently; HIV-1 will bind to any appropriate RNA whereas HIV-2 will preferentially bind to the mRNA which was used to create the Gag protein itself. This may mean that HIV-1 is better able to mutate (HIV-1 infection progresses to AIDS faster than HIV-2 infection and is responsible for the majority of global infections) Assembly and release The final step of the viral cycle, assembly of new HIV-1 virons, begins at the plasma membrane of the host cell. The Env polyprotein (gp160) goes through the endoplasmic reticulum and is transported to the Golgi complex where it is cleaved by protease and processed into the two HIV envelope glycoproteins gp41 and gp120. These are transported to the plasma membrane of the host cell where gp41 anchors the gp120 to the membrane of the infected cell. The Gag (p55) and Gag-Pol (p160) polyproteins also associate with the inner surface of the plasma membrane along with the HIV genomic RNA as the forming virion begins to bud from the host cell. Maturation either occurs in the forming bud or in the immature virion after it buds from the host cell. During maturation, HIV proteases cleave the polyproteins into individual functional HIV proteins and enzymes. The various structural components then assemble to produce a mature HIV virion. This cleavage step can be inhibited by protease inhibitors. The mature virus is then able to infect another cell. HIV differs from many other viruses as it has very high genetic variability. This diversity is a result of its fast replication cycle, with the generation of 109 to 1010 virions every day, coupled with a high mutation rate of approximately 3 x 10-5 per nucleotide base per cycle of replication and recombinogenic properties of reverse transcriptase. This complex scenario leads to the generation of many variants of HIV in a single infected patient in the course of one day. This variability is compounded when a single cell is simultaneously infected by two or more different strains of HIV. When simultaneous infection occurs, the genome of progeny virions may be composed of RNA strands from two different strains. This hybrid virion then infects a new cell where it undergoes replication. As this happens, the reverse transcriptase, by jumping back and forth between the two different RNA templates, will generate a newly synthesized retroviral DNA sequence that is a recombinant between the two parental genomes. This recombination is most obvious when it occurs between subtypes. The closely related simian immunodeficiency virus (SIV) exhibits a somewhat different behavior: in its natural hosts, African green monkeys and sooty mangabeys, the retrovirus is present in high levels in the blood, but evokes only a mild immune response, does not cause the development of simian AIDS, and does not undergo the extensive mutation and recombination typical of HIV. By contrast, infection of heterologous hosts (rhesus or cynomologus macaques) with SIV results in the generation of genetic diversity that is on the same order as HIV in infected humans; these heterologous hosts also develop simian AIDS. The relationship, if any, between genetic diversification, immune response, and disease progression is unknown. Three groups of HIV-1 have been identified on the basis of differences in env: M, N, and O. Group M is the most prevalent and is subdivided into eight subtypes (or clades), based on the whole genome, which are geographically distinct. The most prevalent are subtypes B (found mainly in North America and Europe), A and D (found mainly in Africa), and C (found mainly in Africa and Asia); these subtypes form branches in the phylogenetic tree representing the lineage of the M group of HIV-1. Coinfection with distinct subtypes gives rise to circulating recombinant forms (CRFs). In 2000, the last year in which an analysis of global subtype prevalence was made, 47.2% of infections worldwide were of subtype C, 26.7% were of subtype A/CRF02_AG, 12.3% were of subtype B, 5.3% were of subtype D, 3.2% were of CRF_AE, and the remaining 5.3% were composed of other subtypes and CRFs. Most HIV-1 research is focused on subtype B; few laboratories focus on the other subtypes. The genetic sequence of HIV-2 is only partially homologous to HIV-1 and more closely resembles that of SIV than HIV-1. generalized graph of the relationship between HIV copies (viral load) and CD4 counts over the average course of untreated HIV infection; any particular individual's disease course may vary considerably. --- CD4+ T cell count (cells per µL) --- HIV RNA copies per mL of plasma The clinical course of infection Infection with HIV-1 is associated with a progressive decrease of the CD4+ T cell count and an increase in viral load. The stage of infection can be determined by measuring the patient's CD4+ T cell count, and the level of HIV in the blood. The initial infection with HIV generally occurs after transfer of body fluids from an infected person to an uninfected one. The first stage of infection, the primary, or acute infection, is a period of rapid viral replication that immediately follows the individual's exposure to HIV leading to an abundance of virus in the peripheral blood with levels of HIV commonly approaching several million viruses per mL. This response is accompanied by a marked drop in the numbers of circulating CD4+ T cells. This acute viremia is associated in virtually all patients with the activation of CD8+ T cells, which kill HIV-infected cells, and subsequently with antibody production, or seroconversion. The CD8+ T cell response is thought to be important in controlling virus levels, which peak and then decline, as the CD4+ T cell counts rebound to around 800 cells per mL (the normal value is 1200 cells per mL ). A good CD8+ T cell response has been linked to slower disease progression and a better prognosis, though it does not eliminate the virus. During this period most individuals (80 to 90%) develop an influenza-like illness with symptoms of fever, malaise, lymphadenopathy, pharyngitis, headache, myalgia, and sometimes a rash. Because of the nonspecific nature of these illnesses, it is often not recognized as a sign of HIV infection. Even if patients go to their doctors or a hospital, they will often be misdiagnosed as having one of the more common infectious diseases with the same symptoms. Consequently, these primary symptoms are not used to diagnose HIV infection as they do not develop in all cases and because many are caused by other more common diseases. However, recognizing the syndrome can be important because the patient is much more infectious during this period. A strong immune defense reduces the number of viral particles in the blood stream, marking the start of the infection's clinical latency stage. Clinical latency can vary between two weeks and 20 years. During this early phase of infection, HIV is active within lymphoid organs, where large amounts of virus become trapped in the follicular dendritic cells (FDC) network. The surrounding tissues that are rich in CD4+ T cells may also become infected, and viral particles accumulate both in infected cells and as free virus. Individuals who are in this phase are still infectious. During this time, CD4+ CD45RO+ T cells carry most of the proviral load. When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and infections with a variety of opportunistic microbes appear. The first symptoms often include moderate and unexplained weight loss, recurring respiratory tract infections (such as sinusitis, bronchitis, otitis media, pharyngitis), and oral ulcerations. Common opportunistic infections and tumors, most of which are normally controlled by robust CD4+ T cell-mediated immunity then start to affect the patient. Typically, resistance is lost early on to oral Candida species and to Mycobacterium tuberculosis, which leads to an increased susceptibilty to oral candidiasis (thrush) and tuberculosis. Later, reactivation of latent herpes viruses causes patients to suffer from shingles from Epstein-Barr virus-induced B-cell lymphomas, and from Kaposi's sarcoma, a tumor of endothelial cells that occurs when HIV proteins such as Tat interact with Human Herpesvirus-8. Pneumonia caused by the fungus Pneumocystis jiroveci is common and often fatal. In the final stages of AIDS, infection with cytomegalovirus (another herpes virus) or Mycobacterium avium complex is more prominent. Not all patients with AIDS get all these infections or tumors, and there are other tumors and infections that are less prominent but still significant. Many people are unaware that they are infected with HIV. For example, less than 1% of the sexually active urban population in Africa have been tested and this proportion is even lower in rural populations. Furthermore, only 0.5% of pregnant women attending urban health facilities are counselled, tested or receive their test results. Again, this proportion is even lower in rural health facilities. Since donors may therefore be unaware of their infection, donor blood and blood products used in medicine and medical research are routinely screened for HIV. HIV-1 testing consists of initial screening with an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to HIV-1. Specimens with a nonreactive result from the initial ELISA are considered HIV-negative unless new exposure to an infected partner or partner of unknown HIV status has occurred. Specimens with a reactive ELISA result are retested in duplicate. If the result of either duplicate test is reactive, the specimen is reported as repeatedly reactive and undergoes confirmatory testing with a more specific supplemental test (e.g., Western blot or, less commonly, an immunofluorescence assay (IFA)). Only specimens that are repeatedly reactive by ELISA and positive by IFA or reactive by Western blot are considered HIV-positive and indicative of HIV infection. Specimens that are repeatedly ELISA-reactive occasionally provide an indeterminate Western blot result, which may be either an incomplete antibody response to HIV in an infected person, or nonspecific reactions in an uninfected person. Although IFA can be used confirm infection in these ambiguous cases, this assay is not widely used. Generally, a second specimen should be collected >1 month later and retested for persons with indeterminate Western blot results. Although much less commonly available, nucleic acid testing (e.g., viral RNA or proviral DNA amplification method) can also help diagnosis in certain situations. In addition, a few tested specimens might provide inconclusive results because of a low quantity specimen. In these situations, a second specimen is collected and tested for HIV infection. The chemical structure of Abacavir There is currently no vaccine or cure for HIV or AIDS. The only known method of prevention is avoiding exposure to the virus. However, an antiretroviral treatment, known as post-exposure prophylaxis is believed to reduce the risk of infection if begun directly after exposure. Current treatment for HIV infection consists of highly active antiretroviral therapy, or HAART. This has been highly beneficial to many HIV-infected individuals since its introduction in 1996, when the protease inhibitor-based HAART initially became available. Current HAART options are combinations (or "cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of anti-retroviral agents. Typically, these classes are two nucleoside analogue reverse transcriptase inhibitors (NARTIs or NRTIs) plus either a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor (NNRTI). Because AIDS progression in children is more rapid and less predictable than in adults, particularly in young infants, more aggressive treatment is recommended for children than adults. In developed countries where HAART is available, doctors assess their patients thoroughly: measuring the viral load, how fast CD4 declines, and patient readiness. They then decide when to recommend starting treatment. HAART allows the stabilisation of the patient’s symptoms and viremia, but it neither cures the patient, nor alleviates the symptoms, and high levels of HIV-1, often HAART resistant, return once treatment is stopped. Moreover, it would take more than a lifetime for HIV infection to be cleared using HAART. Despite this, many HIV-infected individuals have experienced remarkable improvements in their general health and quality of life, which has led to a large reduction in HIV-associated morbidity and mortality in the developed world. A computer based study in 2006 projected that following the 2004 United States treatment guidelines gave an average life expectancy of an HIV infected individual to be 32.1 years from the time of infection if treatment was started when the CD4 count was 350/µL. This study was limited as it did not take into account possible future treatments and the projection has not been confirmed within a clinical cohort setting. In the absence of HAART, progression from HIV infection to AIDS has been observed to occur at a median of between nine to ten years and the median survival time after developing AIDS is only 9.2 months. However, HAART sometimes achieves far less than optimal results, in some circumstances being effective in less than fifty percent of patients. This is due to a variety of reasons such as medication intolerance/side effects, prior ineffective antiretroviral therapy and infection with a drug-resistant strain of HIV. However, non-adherence and non-persistence with antiretroviral therapy is the major reason most individuals fail to benefit from HAART. The reasons for non-adherence and non-persistence with HAART are varied and overlapping. Major psychosocial issues, such as poor access to medical care, inadequate social supports, psychiatric disease and drug abuse contribute to non-adherence. The complexity of these HAART regimens, whether due to pill number, dosing frequency, meal restrictions or other issues along with side effects that create intentional non-adherence also contribute to this problem. The side effects include lipodystrophy, dyslipidaemia, insulin resistance, an increase in cardiovascular risks and birth defects. Anti-retroviral drugs are expensive, and the majority of the world's infected individuals do not have access to medications and treatments for HIV and AIDS. Research to improve current treatments includes decreasing side effects of current drugs, further simplifying drug regimens to improve adherence, and determining the best sequence of regimens to manage drug resistance. Unfortunately, only a vaccine is thought to be able to halt the pandemic. This is because a vaccine would cost less, thus being affordable for developing countries, and would not require daily treatment. However, after over 20 years of research, HIV-1 remains a difficult target for a vaccine. Prevalence of HIV among adults per country at the end of 2005 15–50% 5–15% 1–5% 0.5–1.0% 0.1–0.5% <0.1% UNAIDS and the WHO estimate that AIDS has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive pandemics in recorded history. Despite recent, improved access to antiretroviral treatment and care in many regions of the world, the AIDS pandemic claimed an estimated 2.8 million (between 2.4 and 3.3 million) lives in 2005 of which more than half a million (570,000) were children. Globally, between 33.4 and 46 million people currently live with HIV. In 2005, between 3.4 and 6.2 million people were newly infected and between 2.4 and 3.3 million people with AIDS died, an increase from 2004 and the highest number since 1981. Sub-Saharan Africa remains by far the worst-affected region, with an estimated 21.6 to 27.4 million people currently living with HIV. Two million [1.5–3.0 million] of them are children younger than 15 years of age. More than 64% of all people living with HIV are in sub-Saharan Africa, as are more than three quarters of all women living with HIV. In 2005, there were 12.0 million [10.6–13.6 million] AIDS orphans living in sub-Saharan Africa 2005. South & South East Asia are second-worst affected with 15% of the total. AIDS accounts for the deaths of 500,000 children in this region. Two-thirds of HIV/AIDS infections in Asia occur in India, with an estimated 5.7 million infections (estimated 3.4–9.4 million) (0.9% of population), surpassing South Africa's estimated 5.5 million (4.9–6.1 million) (11.9% of population) infections, making India the country with the highest number of HIV infections in the world. In the 35 African nations with the highest prevalence, average life expectancy is 48.3 years—6.5 years less than it would be without the disease. The latest evaluation report of the World Bank's Operations Evaluation Department assesses the development effectiveness of the World Bank's country-level HIV/AIDS assistance defined as policy dialogue, analytic work, and lending with the explicit objective of reducing the scope or impact of the AIDS epidemic. This is the first comprehensive evaluation of the World Bank's HIV/AIDS support to countries, from the beginning of the epidemic through mid-2004. Because the Bank aims to assist in implementation of national government programmes, their experience provides important insights on how national AIDS programmes can be made more effective. The development of HAART as effective therapy for HIV infection and AIDS has substantially reduced the death rate from this disease in those areas where these drugs are widely available. This has created the misperception that the disease has gone away. In fact, as the life expectancy of persons with AIDS has increased in countries where HAART is widely used, the number of persons living with AIDS has increased substantially. In the United States, the number of persons with AIDS increased from about 35,000 in 1988 to over 220,000 in 1996. In Africa, the number of MTCT and the prevalence of AIDS is beginning to reverse decades of steady progress in child survival. Countries such as Uganda are attempting to curb the MTCT epidemic by offering VCT (voluntary counselling and testing), PMTCT (prevention of mother-to-child transmission) and ANC (ante-natal care) services, which include the distribution of antiretroviral therapy. A small minority of scientists and activists question the connection between HIV and AIDS, the existence of HIV itself, or the validity of current testing methods. These claims are considered unsupported by most of the scientific community, who accuse the dissenters of selectively ignoring evidence in favor of HIV's role in AIDS and irresponsibly posing a threat to public health by discouraging HIV testing and proven treatments. AIDS dissidents assert that the current mainstream approach to AIDS, based on HIV causation, has resulted in inaccurate diagnoses, psychological terror, toxic treatments, and a squandering of public funds. Dissident views have been widely rejected, and are considered pseudoscience by the mainstream scientific community. Notes and references A taste for adventure capitalists Solar Cola - the healthier cola alternative This website is Copyright © 1999 & 2007 NJK. The bird logo and name Solar Navigator are trademarks. All rights reserved. All other trademarks are hereby acknowledged. Max Energy Limited is an educational charity.
Image credit: ESA Will swarms of co-operating robots one day be exploring some of the most intriguing worlds in the solar system? James Law, an engineer who is a doctoral student at the Open University, supports the idea that using whole teams of robotic explorers working together offers distinct advantages, especially when it comes to tackling the challenges presented by remote bodies such as Europa and Titan. In a presentation on Wednesday 31 March at the Royal Astronomical Society’s National Astronomy Meeting at the Open University, he will be reviewing some current ideas on co-operative robot technology and suggesting how it might be applied to a Titan mission with a concept for a ‘Master’ robot controlling a bevy of ‘Slaves’. Of the 17 landers sent to investigate Mars, only 5 have survived to perform their missions. In spite of this, scientists are already looking for their next planetary targets, with Saturn’s moon Titan and Jupiter’s moon Europa being distinct possibilities. Given both the greater distances involved, and extreme climatic conditions, how can the likelihood of a successful robotic surface mission be increased? Although robotic rovers have become the preferred choice over static landers, due to their greater versatility, the addition of motion systems increases their weight and reduces the reliability of these already complex mechanisms. Advantages of teamwork One alternative, proposed in 1989 by Rodney Brooks of the Massachusetts Institute of Technology, is finally coming to fruition – the idea of replacing solitary rovers with swarms of cooperative robots. With scientific equipment evenly distributed between them, each rover can be made smaller, lighter, and less complex. These robots can then work together or independently, in order to complete the mission objectives. This approach has several distinct advantages. Launch costs could be reduced and soft landings achieved by delivering lighter payloads. Robustness is improved, since a critical failure on any rover is isolated from the rest. Although losing a rover may restrict the capabilities of the swarm, it is not likely to result in termination of the mission. Indeed, in many cases the affected rover will still be able to play a useful, though limited role. Robotic swarms permit a variety of new missions, such as simultaneous measurements over wide areas, useful in climate monitoring and seismic sounding, or multiple experiments performed concurrently by different robots. Rovers can also work together to access areas of greater scientific interest, for example cliff faces. James Law cites David Barnes of the University of Wales at Aberystwyth, who is developing a swarm of aerobots – flying robots which could be used for terrain mapping or deploying smaller micro rovers. Another benefit of using small cooperative rovers is that additional robots can be launched and integrated into the swarm to extend a mission, enabling new experiments, or replacement of lost and damaged rovers. Robots for Titan In his talk, James Law will present his own vision for a mission to Titan. Though we have to wait for the Huygens probe, due to land on Titan early next year, to discover the true nature of Titan’s surface, it is likely to be mixed. “In this situation, a Master-Slave robot configuration with a variety of transport modes could be favourable,” he suggests. “A ‘Master’ lander supplying power and communications provides an outpost for a number of small ‘Slave’ rovers and balloons. The lander would be equipped with a range of scientific packages, which it could distribute amongst its slave robots depending on the environment around the landing site. These subordinate robots are then able to act either cooperatively – for example, to dig and image a trench in order to investigate its geological layers – or on their own, analysing or collecting samples and returning them to the lander for more in-depth analysis. The rovers would return to the lander to recharge their batteries and change their scientific payloads. Robots capable of operating in a liquid environment could be dispersed on any Titan sea to measure wave motion, perhaps by balloon, then be sacrificed, by ‘drowning’, to measure conditions below the surface.” Among schemes proposed by others that James Law will review is one for the exploration of Europa, devised by Jeff Johnson of the Open University and Rodney Buckland of the University of Kent. It involves Self Organising IMAging Robots, or soimars, small cube-shaped robots each carrying a single-pixel imaging device (such as a photodiode) and weighing as little as 10 grams. Each one is able to communicate with its neighbours and is capable of moving in water, using small propulsion screws. A swarm of these tiny robots could be deployed into a sub surface ocean on Europa to image the environment. A transport craft containing communications and power facilities would land on Europa’s ice crust and release an ice-penetrating device containing the soimars. This device would bore through the ice and release the soimars into the ocean. The soimars then self-organise into a stack, aligning their imaging devices. By cooperatively swimming, the stack scans an area under the ice. If a single imaging device fails, the faulty soimar is simply released and the swarm reorganises to form an error free array. This also enables more soimars, perhaps from subsequent landers, to join the swarm and improve the image resolution. In this configuration, the soimars are physically attached to one another. An alternative use would be to equip them with touch sensors and have them swim as a dispersed cloud along the ocean floor, mapping its elevation. A simulation has been developed at the Open University to demonstrate the self-organising behaviour of the swarm. A mechanical workforce for Mars The Jet Propulsion Laboratory (JPL) has research underway on cooperative robot teams, including robotic work crews for carrying large items, robotic excavation teams, and robots that can rappel one another down steep cliff faces. An objective of this work at JPL is to deploy a robotic workforce on Mars to construct mining and refining facilities, which will provide fuel for future human missions. With proposals to land men on Mars, and eventually more distant locations, these robotic work crews will be indispensable in both investigating the destinations, and creating outposts to support our arrival. Original Source: RAS News Release
- Michael Caronna/Reuters Recent discoveries have revealed that much of the traditional understanding of the human origin story is wrong. Until the past few years, most anthropologists and archaeologists believed that the first members of our species – Homo sapiens – evolved in East Africa approximately 200,000 years ago. As that story goes, humanity mostly remained in Africa for the next 140,000 years, then ventured forth as part of a major wave known as the “Out of Africa” migration approximately 60,000 years ago. In this version of history, those early ancestors took over territories once occupied by less advanced species like the Neanderthals. Then humans reached North America about 16,000 t0 25,000 years ago. But this understanding of history has been thoroughly upended by a number of discoveries over the past few years. There’s less certainty now about how long ago modern humans truly evolved, when people spread around the world, and how we co-existed with a number of other hominid species. New findings suggest that many events happened much longer ago in history than researchers previously thought. The process of our own evolution – and our relationships with other co-existent hominin species – are also made messier by many of these discoveries. Here are some of the recent discoveries that have begun to upend what we thought we knew about the human origin story. The first <em>Homo sapiens</em> seem to have appeared more than 100,000 years earlier than scientists previously thought — and in different locations. - Shannon McPherron, MPI EVA Leipzig The bones were unearthed in Morocco, and showed that humans had been around for far longer than 200,000 years. The discovery was also evidence that our earliest ancestors may not have been located in just one area, since this showed that even the earliest members of our species were in North Africa, far from spots often considered the birthplace of humanity. “There is no Garden of Eden in Africa, or if there is, it is all of Africa,” anthropologist Jean-Jacques Hublin, who led the expedition to unearth the skulls, said at the time. These discoveries helped lead to a new idea: perhaps <em>Homo sapiens</em> actually evolved all over Africa in interlinked groups that became more similar over time. - Thomson Reuters As a team of researchers described in a recent paper, groups of Homo sapiens may have evolved contemporaneously all over Africa, instead of just in one primary location. Not all of these groups would have looked identical at the start, but they may have been close enough to all be considered Homo sapiens, even if they weren’t the same as the modern versions of humanity. So instead of first emerging in a site in East or South Africa (depending on which version of the traditional origin story you subscribe to) and then spreading from there, distantly related groups of humans across the continent could have become more similar over time. This idea is known as the “African multiregionalism” theory. - Shannon McPherron, Max Planck Institute for Evolutionary Anthropology According to this logic, distantly related groups could have all evolved from a widespread ancient hominid relative. In different locations, they may have interbred with and picked up traits from other ancient hominids, as we know Homo sapiens have done over time. (In general, the term hominid describes great apes, humans, and all our extinct ancestors; the term hominin is a bit more narrow referring only to humans and our more closely related extinct ancestors.) Ed Yong at The Atlantic wrote that the best way to understand this theory isn’t to think of evolution as a tree in which modern humans branched off and became a separate group. “It’s a braided river – a group of streams that are all part of the same system, but that weave into and out of each other,” Yong wrote. “These streams eventually merge into the same big channel, but it takes time – hundreds of thousands of years. For most of our history, any one group of Homo sapiens had just some of the full constellation of features that we use to define ourselves.” We’ve also discovered new hominids that our ancestors may have lived alongside or even occasionally mated with. - Siphiwe Sibeko/Reuters In 2013, two spelunkers in South Africa spotted something promising in a cave. They told National Geographic explorer-in-residence Lee Berger of their find. Berger put out an ad searching for scientists who could excavate, go caving, climb, and fit into tiny spaces. He ended up recruiting an international team of six female scientists – later dubbed “underground astronauts” – who made their way into the cave. Inside, they discovered thousands of bones from an ancient hominid that had never before been seen. The researchers described it in a 2015 paper with the name Homo naledi. This small hominid may have lived alongside early Homo sapiens. The discovery also suggested that there may have been many other early hominid species that we co-existed with before becoming the one dominant remaining member of the Homo genus. Some early art that was previously attributed to Homo sapiens was really created by Neanderthals. - Thomson Reuters We may not have been as different from other hominids as scientists used to think. Even if Homo sapiens evolved before we thought, Neanderthals were around first, appearing in the fossil record at least 400,000 years back. Many researchers assumed those Homo neanderthalis were far more primitive than their later-evolving relatives. But new discoveries challenge that line of thinking. Long before what researchers refer to as “modern” humans ever reached Europe, our Neanderthal cousins were creating cultural objects and painting in caves in Spain, according to several recently published studies. The new research pinpointed when some of the first European art that we know of was created, and it turns out the visual work was happening before many places were settled by Homo sapiens. That indicates Neanderthals and early humans may have been very similar cognitively and culturally. We’ve also found more genetic evidence that shows ancient humans interbred several times with hominin species like Denisovans and Neanderthals. - Thomson Reuters We’ve long known that humans mixed with Neanderthals, since most present-day non-Africans have at least some Neanderthal DNA. But that wasn’t the only other species we mixed with. A 2018 genetic study found that more than once, humans mixed with Denisovans – other hominins that existed when early Homo sapiens were making their way out of Africa. Up to 5% of the DNA of modern residents of Papua New Guinea show traces of interbreeding with Denisovans. Smaller traces of those ancient liaisons are found across Asia, too, but we still don’t know too much about Denisovans and our interactions with them. The earliest humans left Africa long before we thought, according to recent research. - Bae et al. 2017. On the origin of modern humans: Asian perspectives. Science. Image by: Katerina Douka and Michelle O’Reilly The first Homo sapiens may have left Africa and started migrating into Asia more than 120,000 years ago – far earlier than scientists previously thought, according to a review of recent research published in the journal Science in late 2017. “The initial dispersals out of Africa prior to 60,000 years ago were likely by small groups of foragers, and at least some of these early dispersals left low-level genetic traces in modern human populations,” Michael Petraglia, an archaeologist at the Max Planck Institute for the Science of Human History and an author of the study, said in a press release. “A later, major ‘Out of Africa’ event most likely occurred around 60,000 years ago or thereafter.” Some researchers even think humans arrived in North America earlier than the traditionally accepted timeline, though this is still controversial. - Thomson Reuters Most evidence indicates that humans first reached North America between 16,000 and 25,000 years ago. But given the upheaval that other recent discoveries have caused, it seems possible that some groups could have arrived before then. At least one team of researchers thinks some sort of hominid could have reached the Americas 100,000 years earlier than the traditionally accepted timeline. That idea is based on the discovery of mastodon bones at a site near what’s now San Diego, California. The bones were found to have been broken apart after the death of the animal, and fragments of what appear to be ancient tools were also found at the site. That indicates that hominids may have stretched into North America early on. However, the findings are still far from certain. Plus, given that other early hominids seem to have been more widespread and intelligent than we thought, it’s possible that early North Americans could have been some other ancient ancestor, not Homo sapiens. The timing and route that <em>Homo sapiens</em> took into North America is still being debated. - Ben A. Potter Over the past decade, the main idea of how Homo sapiens first arrived in North America has been that they took a route along the Pacific coast sometime 25,000 to 15,000 years ago. But the authors of a new review of research published August 8 say the path that humans took to become the first Native Americans is still unclear. Looking at all the evidence, it’s possible that humans could have traveled either along the coast or through an inland, ice-free corridor between two massive ice sheets. This latter route is the one researchers used to favor before the idea of a coastal journey became prominent. The authors suggest a simple solution to this question: some of the first humans to reach North America may have used both routes. Although some researchers want to push the timeline earlier, the authors of this review argue that there’s not necessarily any reason to believe that people crossed into the Americas until 16,000 years ago. Much more research on this is still needed, though. There’s still a lot we don’t know about the human origin story. - Brian Villmoare As all these findings show, there’s a lot of the human origin story that we have yet to fully understand. Recent research has called into question traditional narratives about the history of our ancestors and the creatures we co-existed with. The reality seems to be messier and less straightforward than previously thought. We’re still finding traces of history buried away in caves or even in large analyses of our genetic code that weren’t possible until recently. We surely have much to learn. This story was originally published July 22, 2018, and has been updated with new findings.
Chapter Nine (Part 2) \|Table of Content\|\| Chapter Nine (Part 4) ARITHMETIC AND LOGICAL OPERATIONS (Part 3) 9.3.1 - Multiprecision Addition Operations 9.3.2 - Multiprecision Subtraction Operations 9.3.3 - Extended Precision Comparisons 9.3 Multiprecision Operations One big advantage of assembly language over HLLs is that assembly language does not limit the size of integers. For example the C programming language defines a maximum of three different integer sizes: long int. On the PC these are often 16 or 32 bit integers. Although the 80x86 machine instructions limit you to processing eight or thirty-two bit integers with a single instruction you can always use more than one instruction to process integers of any size you desire. If you want 256 bit integer values The following sections describe how extended various arithmetic and logical operations from 16 or 32 bits to as many bits as you please. 9.3.1 Multiprecision Addition Operations add instruction adds two 8 32 bit numbers. After the execution of the the 80x86 carry flag is set if there is an overflow out of the H.O. bit of the sum. You can use this information to do multiprecision addition operations. Consider the way you manually perform a multidigit (multiprecision) addition operation: Step 1: Add the least significant digits together: 289 289 +456 produces +456 ---- ---- 5 with carry 1. Step 2: Add the next significant digits plus the carry: 1 (previous carry) 289 289 +456 produces +456 ---- ---- 5 45 with carry 1. Step 3: Add the most significant digits plus the carry: 1 (previous carry) 289 289 +456 produces +456 ---- ---- 45 745 The 80x86 handles extended precision arithmetic in an identical fashion except instead of adding the numbers a digit at a time it adds them a byte or a word at a time. Consider the three-word (48 bit) addition operation shown below: add instruction adds the L.O. words adc (add with carry) instruction adds all other word pairs adc instruction adds two operands plus the carry flag together producing a word value and (possibly) a carry. For example suppose that you have two thirty-two bit values you wish to add together defined as follows: X dword ? Y dword ? that you want to store the sum in a third that is likewise defined with the dword directive. The following 80x86 code will accomplish this task: mov ax word ptr X add ax word ptr Y mov word ptr Z ax mov ax word ptr X+2 adc ax word ptr Y+2 mov word ptr Z+2 ax these variables are declared with the directive. Therefore the assembler will not accept an instruction of the form X because this instruction would attempt to load a 32 bit value into a 16 bit register. Therefore this code uses the word ptr coercion operator to coerce symbols Z to 16 bits. The first three instructions add the L.O. Y together and store the result at the L.O. word Z. The last three instructions add the H.O. words of along with the carry out of the L.O. word and store the result in the H.O. word address expressions of the form "X+2" access the H.O. word of a 32 bit entity. This is due to the fact that the 80x86 address space addresses bytes and it takes two consecutive bytes to form a word. Of course if you have an 80386 or later processor you needn't go through all this just to add two 32 bit values together since the 80386 directly supports 32 bit operations. However if you wanted to add two 64 bit integers together on the 80386 you would still need to use this technique. You can extend this to any number of bits by using the instruction to add in the higher order words in the values. For example to add together two 128 bit values you could use code that looks something like the following: BigVal1 dword 0 0 0 0 ;Four double words in 128 bits! BigVal2 dword 0 0 0 0 BigVal3 dword 0 0 0 0 . . . mov eax BigVal1 ;No need for dword ptr operator since add eax BigVal2 ; these are dword variables. mov BigVal3 eax mov eax BigVal1+4 ;Add in the values from the L.O. adc eax BigVal2+4 ; entity to the H.O. entity using mov BigVal3+4 eax ; the ADC instruction. mov eax BigVal1+8 adc eax BigVal2+8 mov BigVal3+8 eax mov eax BigVal1+12 adc eax BigVal2+12 mov BigVal3+12 eax the 80x86 performs multi-byte subtraction the same way you would manually except it subtracts whole bytes or double words at a time rather than decimal digits. The mechanism is similar to that for the You use the sub instruction on the L.O. byte/word/double word and the sbb instruction on the high order values. The following example demonstrates a 32 bit subtraction using the 16 bit registers on the 8086: var1 dword ? var2 dword ? diff dword ? mov ax word ptr var1 sub ax word ptr var2 mov word ptr diff ax mov ax word ptr var1+2 sbb ax word ptr var2+2 mov word ptr diff+2 ax The following example demonstrates a 128-bit subtraction using the 80386 32 bit register set: BigVal1 dword 0 0 0 0 ;Four double words in 128 bits! BigVal2 dword 0 0 0 0 BigVal3 dword 0 0 0 0 . . . mov eax BigVal1 ;No need for dword ptr operator since sub eax BigVal2 ; these are dword variables. mov BigVal3 eax mov eax BigVal1+4 ;Subtract the values from the L.O. sbb eax BigVal2+4 ; entity to the H.O. entity using mov BigVal3+4 eax ; the SUB and SBB instructions. mov eax BigVal1+8 sbb eax BigVal2+8 mov BigVal3+8 eax mov eax BigVal1+12 sbb eax BigVal2+12 mov BigVal3+12 eax there isn't a "compare with borrow" instruction that can be used to perform extended precision comparisons. Since sub instructions perform the same operation least as far as the flags are concerned you'd probably guess that you could use the instruction to synthesize an extended precision comparison; however you'd only be partly right. There is a better way. Consider the two unsigned values 2157h and 1293h. The L.O. bytes of these two values do not affect the outcome of the comparison. Simply comparing 21h with 12h tells us that the first value is greater than the second. In fact the only time you ever need to look at both bytes of these values is if the H.O. bytes are equal. In all other cases comparing the H.O. bytes tells you everything you need to know about the values. Of course this is true for any number of bytes not just two. The following code compares two signed 64 bit integers on an 80386 or later processor: ; This sequence transfers control to location "IsGreater" if ; QwordValue > QwordValue2. It transfers control to "IsLess" if ; QwordValue < QwordValue2. It falls though to the instruction ; following this sequence if QwordValue = QwordValue2. To test for ; inequality change the "IsGreater" and "IsLess" operands to "NotEqual" ; in this code. mov eax dword ptr QWordValue+4 ;Get H.O. dword cmp eax dword ptr QWordValue2+4 jg IsGreater jl IsLess mov eax dword ptr QWordValue cmp eax dword ptr QWordValue2 jg IsGreater jl IsLess To compare unsigned values simply use the ja and jb instructions in place of jg and jl. You can easily synthesize any possible comparison from the sequence above the following examples show how to do this. These examples do signed comparisons substitute ja jae jb and jbe for jg jge jl and jle (respectively) to do unsigned comparisons. QW1 qword ? QW2 qword ? dp textequ <dword ptr> ; 64 bit test to see if QW1 < QW2 (signed). ; Control transfers to "IsLess" label if QW1 < QW2. Control falls ; through to the next statement if this is not true. mov eax dp QW1+4 ;Get H.O. dword cmp eax dp QW2+4 jg NotLess jl IsLess mov eax dp QW1 ;Fall through to here if H.O. cmp eax dp QW2 ; dwords are equal. jl IsLess NotLess: ; 64 bit test to see if QW1 <= QW2 (signed). mov eax dp QW1+4 ;Get H.O. dword cmp eax dp QW2+4 jg NotLessEq jl IsLessEq mov eax dp QW1 cmp eax dword ptr QW2 jle IsLessEq NotLessEQ: ; 64 bit test to see if QW1 >QW2 (signed). mov eax dp QW1+4 ;Get H.O. dword cmp eax dp QW2+4 jg IsGtr jl NotGtr mov eax dp QW1 ;Fall through to here if H.O. cmp eax dp QW2 ; dwords are equal. jg IsGtr NotGtr: ; 64 bit test to see if QW1 >= QW2 (signed). mov eax dp QW1+4 ;Get H.O. dword cmp eax dp QW2+4 jg IsGtrEq jl NotGtrEq mov eax dp QW1 cmp eax dword ptr QW2 jge IsGtrEq NotGtrEq: ; 64 bit test to see if QW1 = QW2 (signed or unsigned). This code branches ; to the label "IsEqual" if QW1 = QW2. It falls through to the next instruction ; if they are not equal. mov eax dp QW1+4 ;Get H.O. dword cmp eax dp QW2+4 jne NotEqual mov eax dp QW1 cmp eax dword ptr QW2 je IsEqual NotEqual: ; 64 bit test to see if QW1 <> QW2 (signed or unsigned). This code branches ; to the label "NotEqual" if QW1 <> QW2. It falls through to the next ; instruction if they are equal. mov eax dp QW1+4 ;Get H.O. dword cmp eax dp QW2+4 jne NotEqual mov eax dp QW1 cmp eax dword ptr QW2 jne NotEqual As usual 32 bit arithmetic is available only on the 80386 and later processors. Chapter Nine: Arithmetic And Logical Operations (Part 3) 27 SEP 1996
A new study from the University of Colorado Boulder and the California Institute of Technology has analyzed mineral grains from the bottom of the western Grand Canyon. The findings indicate that the canyon was largely carved out about 70 million years ago, putting it in a time when dinosaurs were around and might have peeked over the rim. CU-Boulder Assistant Professor Rebecca Flowers says that this new research, using a dating method that exploits the radioactive decay of uranium and thorium atoms to helium atoms in a phosphate mineral known as apatite, pushes back the accepted formation date of Arizona’s Grand Canyon by more than 60 million years. During the carving of the Grand Canyon, the mineral grains cooled and moved closer to the surface, locking the helium atoms away inside the grains. Topography influences temperature variations at shallow levels beneath the Earth’s surface, and the thermal history recorded by the apatite grains allowed Flowers and her team to infer how much time had passed since there was significant natural excavation of the Grand Canyon. “Our research implies that the Grand Canyon was directly carved to within a few hundred meters of its modern depth by about 70 million years ago,” said Flowers. According to Alicia Chang of the Associated Press (AP), the age and evolution of the Grand Canyon causes significant controversy among scientists, with a variety of data suggesting the Grand Canyon has had a complicated history. This evidence also suggests the modern canyon might not have been carved all at the same time. Different segments of the canyon may have formed separately before coalescing into the Grand Canyon visitors see today. In a previous study published in 2008, Flowers and colleagues revealed that parts of the eastern Grand Canyon likely developed some 55 million years ago. Before it eroded to its current depth, that segment of the canyon’s bottom was above the height of the current rim. The steeply sided Grand Canyon is over a mile deep in places and about 280 miles long with a width of up to 18 miles wide in certain locations. More than 5 million people visit the geographic wonder every year. The Grand Canyon was carved, in large part, by an ancestral waterway of the Colorado River that was flowing in the opposite direction millions of years ago. “An ancient Grand Canyon has important implications for understanding the evolution of landscapes, topography, hydrology and tectonics in the western U.S. and in mountain belts more generally,” said Flowers. “The main thing this technique allows us to do is detect variations in the thermal structure at shallow levels of the Earth’s crust,” she said. “Since these variations are in part induced by the topography of the region, we obtained dates that allowed us to constrain the timeframe when the Grand Canyon was incised.” Past experiments used only the amount of helium produced in the radioactive decay of apatite grains to date samples. Flowers and Farley, however, also analyzed the spatial distribution of helium atoms near the margin of individual apatite crystals in order to take their uranium/thorium/helium dating technique to a more sophisticated level. In recent years, a number of studies have reported various ages for the Grand Canyon, with the most popular theory placing the age at 5 million to 6 million years based on the age of the gravel washed downstream by the ancestral Colorado River. A 2008 study, however, estimated the age to be some 17 million years old based on dating mineral deposits inside of caves carved in the canyon walls. Paleontologists believe that dinosaurs were wiped out when a giant asteroid collided with Earth some 65 million years ago, in a so-called “extinction event.” The collision resulted in huge clouds of dust that blocked the sun from reaching Earth’s surface, cooling the planet and killing most plants and animals. Geologists have redoubled their efforts, according to Flowers, because of the wide numbers of theories, dates and debates regarding the age of the Grand Canyon. “There has been a resurgence of work on this problem over the past few years because we now have some new techniques that allow us to date rocks that we couldn’t date before,” Flowers said. The dating research for this current study was performed at CalTech, however, Flowers has recently set up her own lab at CU-Boulder capable of conducting uranium/thorium/helium dating. “If it were simple, I think we would have solved the problem a long time ago,” said Flowers. “But the variety of conflicting information has caused scientists to argue about the age of the Grand Canyon for more than 150 years. I expect that our interpretation that the Grand Canyon formed some 70 million years ago is going to generate a fair amount of controversy, and I hope it will motivate more research to help solve this problem.” The team hopes to continue their research, moving from “when” to “how” the canyon was formed, claiming the genesis of the canyon has important implications for understanding the evolution of many geological features in the western United States. This would include the features’ tectonics and topography. “Our major scientific objective is to understand the history of the Colorado Plateau–why does this large and unusual geographic feature exist, and when was it formed,” says Farley. “A canyon cannot form without high elevation–you don’t cut canyons in rocks below sea level. Also, the details of the canyon’s incision seem to suggest large-scale changes in surface topography, possibly including large-scale tilting of the plateau.” AP’s Chang reports that not everyone is convinced by the findings of Flowers and Farley’s study, however. The study ignores a mountain of evidence pointing to a geologically young landscape, the critics contend, giving rise to doubts about the technique used to date the team’s samples. Karl Karlstrom, University of New Mexico in Albuquerque geologist, calls the notion of the Grand Canyon being 70 million years old “ludicrous.” Most scientists agree that though the exposed rocks are ancient, the Canyon was forged relatively recently in geologic time through tectonic uplift. The oldest gravel and sediment that washed downstream date to about 6 million years ago, making it hard for most scientists to imagine an ancient Grand Canyon, especially since there are no signs of older deposits. Geologists are always happy to have new methods of dating, however, Karlstrom thinks the newest efforts are highly inaccurate. It defies logic that a fully formed canyon would sit unchanged for tens of millions of years without undergoing further erosion, Karlstrom protests. Richard Young, geologist at the State University of New York at Geneseo, suggested an entirely different scenario to Chang; that of a cliff in the place of the ancient Grand Canyon. According to Young, Flowers “wants to have a canyon there. I want to have a cliff there. Obviously, one of us can’t be right.” There might be a middle ground, suggested Utah State University geologist Joel Pederson to Chang. Older canyons in the region were cut by rivers flowing in the opposite direction of the Colorado River. Perhaps, he says, a good portion of the Grand Canyon was chiseled by these smaller rivers and the younger Colorado finished the job. If Flowers and Farley are right, however, and the Canyon existed when dinosaurs roamed, it would be a much different environment than today because the climate at that time was more tropical. Smaller tyrannosaurs, horned and dome-headed dinosaurs and duckbills patrolled the American West. University of Maryland paleontologist Thomas Holtz told Chang that the dinosaurs would not see “the starkly beautiful desert of today, but an environment with more lush vegetation” The results of this study were recently published online in the journal Science Express. Note : The above story is reprinted from materials provided by April Flowers for redOrbit
The First Large Emigration of the Armenians The fall of the city of Ani and the conquest of Armenia by the Seljuk Turks during the 11th century and later the Mongol invasion in the 13th century, caused the first large emigration of the Armenians. Of course, emigrations had occurred earlier, but on a lesser scale. The Byzantine Empire had created Armenian settlements at its borders to set this warrior people against its enemies (in Tracia and Macedonia against the Slavic people, and in Asia Minor against the Arabs). The other period of significant emigration occurred at the beginning of the 11th century when Prince Artzrouni and some of his subjects, weary if the attacks of the Seljuk Turks, handed over his province of Vaspourakan (the region around Van) to Byzantine in exchange for being able to settle down in Sivas. However, it was after the decisive Turanian conquest of Armenia and during the ravages of the Mongols (12th and 13th centuries) that a larger scale Armenian emigration took place. In the previous chapter we looked at the Armenian princes, who decided to resist the enemy, fought their way to freedom and climbed the mountains in Cilicia and there established a new state by the name of New Armenia, which would remain independent for three centuries. Another part of the Armenians, numbering around 200,000, emigrated towards the Crimean Peninsula and Moldavia. During the 13th and the 14th centuries, when the Tartars occupied the Crimean Peninsula, some of these Armenians, around 50,000, settled down in Poland, especially in the province of Lemberg (in Lwow and Leopold). The Polish kings received them with open arms since they recognised the abilities of the Armenians. During the 14th century, the Polish king Casimir III, let the Armenians establish their own national council, consisting of twelve judges in each city they were represented in. Over time the Polish Armenians assimilated the native people through marriage and became Polish. The services which the Armenians rendered in the economic, trade and military spheres for their new country during this period are widely recognised. The Armenians who had emigrated to Moldavia in the 12th and the 13th centuries remained there until the 17th century, but when the Ottoman Turks, in 1675, invaded Moldavia, the majority of them moved to Transylvania or Hungary. In Transylvania the Armenians established cities such as Elisabethpol and Armenierstadt. Kaiser Charles VI, in the 18th century, gave them important rights, proclaiming these two cities and others free. Finally there was the Crimean Peninsula which for a while was called the “Armenian Maritima” and remained as an important Armenian centre until the 18th century.
by Iddo Gal, University of Haifa Excerpted with permission from "Why Numbers Count: Quantitative Literacy for Tomorrow's America," Copyright (c) College Entrance Examination Board, 1997. All rights reserved. A key goal of school is to prepare students for life as adults. However, the form and content of this preparation is not at all clear regarding the quantitative side of the adult world. Since numeracy should serve as the primary (but not exclusive) basis for determining the scope, content, and methods of mathematics instruction and assessment at the K-12 level, the challenge to define and understand numeracy is especially critical. Different agencies employ different "lenses" and make different assumptions about the contexts of people's lives. These sources ... suggest that there are multiple life contexts in which adults may need to deal with situations involving numbers, quantities, mathematical ideas, and algorithmic processes. Examples include: Results from the recent National Adult Literacy Survey show that relatively few American students graduate from school equipped to handle these diverse quantitative tasks. Further, results from the National Assessment of Educational Progress (NAEP) have shown repeatedly over the last twenty-five years that many high school graduates leave school without adequate skills. For instance, only 46% of the high school seniors tested as part of the 1990 NAEP demonstrated consistent mastery of fractions, decimals, percentages, and simple algebra--topics which they should have mastered much earlier. A growing research literature suggests that many students have trouble transferring and applying mathematical skills in new contexts, in or out of the classroom. These findings corroborate the informal observations reported by many mathematics teachers: too many students have trouble dealing with presumably standard problems that they just "successfully" practiced, once minor aspects of the problems are changed. U.S. high schools have historically stressed, explicitly or implicitly, students' ability to reach a stage where they can handle abstract, college-related topics such as advanced algebra and calculus. Yet fewer than 50% of all students who graduate from high school enter college, and many of these never study mathematics any further in college. Students who do not cope well with abstract topics--which many high school mathematics teachers view as "real" mathematics--are usually banished into "general mathematics" or "consumer" courses that many educators consider a dead-end and mathematically uninteresting. Such students receive decidedly insufficient attention from mathematics educators. Being numerate is much more than knowing mathematics, and numeracy is not the same as mathematics. ... Most mathematics problems that students work on are contrived or decontextualized. In contrast, real life numeracy situations are always embedded in a life stream of some personal meaning to the individuals involved. Such situations are rarely emphasized in public discourse within mathematics education. Iddo Gal teaches in the School of Education at the University of Haifa. Until recently he directed the Adult Numeracy Project at the National Center on Adult Literacy at the University of Pennsylvania. He can be reached by e-mail at firstname.lastname@example.org. Last Update: July 17, 1997
An unusually large, long-lasting, and powerful cyclone was churning over the Arctic in early August 2012. Two smaller systems merged on August 5 to form the storm, which at the time occupied much of the Beaufort-Chukchi Sea and Canadian Basin. On average, Arctic cyclones last about 40 hours; as of August 9, 2012, this storm had lasted more than five days. The Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP captured this view of the storm on August 7, 2012. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua captured a natural-color image of the storm as well. Arctic cyclones are more common during the summer than winter; however, summer cyclones tend to be weaker than the storms that batter the region during the winter. This cyclone’s central sea level pressure reached about 964 millibars on August 6, 2012—a number more typical of a winter cyclone. That pressure puts it within the lowest 3 percent of all minimum daily sea level pressures recorded north of 70 degrees latitude, noted Stephen Vavrus, an atmospheric scientist based at the University of Wisconsin. The number of cyclones affecting the Arctic appears to be increasing. According to a study of long-term Arctic cyclone trends authored by a team led by John Walsh and Xiangdong Zhang of the University of Alaska Fairbanks, the number and intensity of Arctic cyclones has increased during the second half of the twentieth century, particularly during the summer. The cause of the increase is an open question, but climate change may be affecting Arctic cyclones. One study published in Atmospheric and Oceanic Science Letters, concluded that the total number of exratropical cyclones in the Northern Hemisphere would decline as the climate changed, but that the Arctic Ocean and adjacent areas would see slightly more and stronger summer storms. One way climate change may affect Arctic cyclones is by changing the sea ice and ocean temperature. Climate change has caused sea ice to retreat markedly in recent decades and has also warmed Arctic Ocean temperatures. Such changes may be providing more energy and moisture to support cyclone development and persistence, Zhang explained. However, scientists who study extratropical storms emphasize that pinning down how exactly climate change is affecting the size, frequency, or tracks of Arctic storms remains an important but unresolved question. “This past week’s storm was exceptional, and the occurrence of Arctic storms of extreme intensity is a topic deserving closer investigation,” noted Walsh. “With reduced ice cover and warmer sea surfaces, the occurrence of more intense storms is certainly a plausible scenario. The limitation at present is the small sample size of exceptional events, but that may change in the future.” - Orsolini, Yvan. (2008, January 16). Projected Changes in Eurasian and Arctic Cyclones Under Global Warming in the Bergen Climate Model. Atmospheric and Oceanic Science Letters. - Zhang, X. (2004, January 2004). Climatology and Interannual Variability of Arctic Cyclone Activity: 1948-2002. Journal of Climate. NASA Earth Observatory image by Jesse Allen and Robert Simmon, using VIIRS data. Caption by Adam Voiland with information from Robert Walsh, Xiangdong Zhang, and Stephen Vavrus. - Suomi NPP - VIIRS
World War II Aircraft Military aircraft in World War II included bombers, fighters, and reconnaissance airplanes, as well as a limited number of cargo transports, gliders, blimps, and even jets. Aircraft of various kinds had played a highly visible, but relatively minor role in World War I, but during World War II they were arguably the most important weapons delivery system. Both the primary aggressors in the war, Germany and Japan, launched their campaigns with heavy air strikes. The German Luftwaffe, or air force, used fighters and dive-bombers to overrun Denmark and Holland early in the war, as a prelude to their capture of France. Fighters such as the Messerschmitt BF-109 and the Focke Wulf 190 proved to be formidable weapons. Then, improved bombers rained bombs on England in an attempt to knock this enemy out of the war. The British responded with advanced fighters such as the famous Spitfire, which was guided by the new technology of radar. This was the Battle of Britain, a conflict fought entirely in the air and which forced a radical change in Germany’s war plans when they found themselves unable to dominate the British skies. Japan also inaugurated its war on the U.S with an air attack. The Japanese used aircraft carriers, which had been in service since the 1920s in the famous Japanese surprise attack on Pearl Harbor, Hawaii, which destroyed most of the U.S Pacific fleet using aircraft almost exclusively. Technologically, military aircraft rapidly evolved during the war. The wood-and-fabric biplanes of the Great War were superseded by sleek aluminum airframes with powerful, often supercharged piston engines. While the British had the Spitfire and the Germans the Messerschmitt, the U.S made innovations as well, developing the successful P-51 Mustang in collaboration with the British, and introducing important innovations in long-range bombers, such as the B-17 “Flying Fortress” and the famous B-29. Radically new types of aircraft also emerged. The Germans, English, and Americans began to experiment with jet-powered aircraft, with the Germans and British actually flying some combat missions in them. These new aircraft achieved very high speeds using the jet engine, a new type of engine that had no propellers. The Germans, and, to a lesser extent, the Americans even developed pilotless, guided missiles during the war, such as Germany’s V1 and V2 weapons. However, the bulk of aerial combat was conducted using propeller-driven, human-piloted fighters and bombers. Over the course of the war, many important battles took place on land and at sea, but it is significant that many of the closing events of the war also depended on aircraft. Once the Allies began retaking territory in Europe, heavy bombers began to attack within Germany. By destroying much of its ability to produce fuel and munitions, bombers turned the tide on the German war effort. Finally, the large bombers developed late in the war, such as the B-29 were huge craft capable of delivering atomic bombs nearly anywhere in the world. The U.S used a B-29 called the Enola Gay in its final airborne attack—dropping the atomic bomb on Japan. By the end of the war in 1945, fighters and bombers had been transformed into highly effective weapons systems. Today’s fighters and bombers use jet engines and remain central to military forces around the world.
Transition Metal Properties Transition metal elements form ions with variable oxidation states. They all form compounds with a +2 oxidation state due to the loss of electrons from the 4s orbital as it is at the highest energy level. The highest oxidation state of a transition element is often found in strong oxidising agents. Managanese forms potassium permanagante. When white light passes through a solution containing transition metal ions, some wavelengths of visible light are absorbed. A solution of copper (II) sulfate appears pale blue because the solution absorbs the red/orange region of the electromagnetic spectrum and reflects or transmits blue. A precipitation reaction is one in which soluble ions, in separate solutions, are mixed together to form an insoluble compound- that settles out of solution as a solid. Transition metals in aqueous solution react with aqueous sodium hydroxide to form coloured precipitates.A blue solution of copper (II) ions reacts with aqueous sodium hydroxide to form a pale blue precipitate of copper (II) hydroxide: Cu2+ (aq) + 2OH- (aq) ---> Cu(OH)2 (s) Pale blue solution Pale blue precipitate Cobalt (II), iron (II) and iron (III) also form precipitates with sodium hydroxide. A ligand substitution reaction is one in which a ligand in a complex ion is replaced with another ligand. An aqueous solution of copper (II) ions contains [Cu(H2O)6]2+ complex ions which have a characteristic pale blue colour. When an excess of aqueous ammonia solution is added, the pale blue solution changes colour and a deep blue solution forms. [Cu(H2O)6]2+ + 4NH3 -><- [Cu(NH3)4(H2O)2]2+ + 4H2O The product has six ligands and is an octahedral shape. The copper-oxygen bonds are longer than the copper-nitrogen bonds, so the shape is described as a distorted octahedral shape. When concentrated hydrochloric acid is added to solution containing copper (II) ions, the pale blue solution initially forms a green solution before turning yellow. This reaction exists in equilibrium and can be reversed by adding water to return it to the original blue colour. [Cu(H2O)6]2+ + 4Cl- -><- [CuCl4]2+ + 6H2O The [CuCl4] complex only has four ligands as there is a stronger repulsion and the chloride ligands are larger, so fewer chloride ions can fit around the central metal ion. [CuCl4] has a tetrahedral shape. Ligand Substitution (cont.) An aqueous solution of cobalt (II) ions contains [Co(H2O)6]2+ complex ions, which have a characteristic pink colour. If concentrated hydrochloric acid is added, the solution forms a dark blue solution. The concentrated hydrochloric acid provides a high concentration of chloride ions, replacing the six water molecules with four chloride ions. [Co(H2O)6]2+ + 4HCl- -><- [CoCl4]2- + 6H2O
What is GTEx, and why is it so important for genetic research? DNA carries the instructions for life. Our bodies are somehow able to construct an entire human being, complete with a functioning heart, an adaptable immune system, and a whole complement of interconnected organs and body tissues, all from a series of As, Ts, Cs, and Gs. Scientists are continually making discoveries that help us understand this process. A relatively new research initiative, the Genotype-Tissue Expression project (GTEx), has set out to make big contributions toward this effort. The excitement around GTEx lies largely in that it has catalogued gene expression—whether a particular gene is read—in dozens of human tissues. Typically, large scale genetic studies focus on associations between specific physical traits (such as obesity, height, athletic ability, caffeine consumption, and so on) and DNA. Genome wide association studies (GWAS) are a good example of this. In a GWAS, DNA is genotyped from a sample population. Typically, this sample population includes both people with and without the trait being studied. (In this context, “trait” can refer to a number of measurements including physical traits like height, hair color, and weight; the presence or absence of a disease; or lifestyle behaviors like a person’s sleep patterns.) Using these large datasets, scientists are able to determine how often a specific DNA sequence is associated with individuals that have the trait. These associations can then be used to describe a person’s likelihood of having that physical trait based on their DNA. For instance, people with a T in a specific location in their DNA near the CYP1A2 gene are significantly more likely to consume more coffee than those who have a C in the same location. While informative, GWAS do have drawbacks. A big one is that they don’t necessarily pinpoint the reason why a DNA variant would be linked to the trait. To help bridge this gap, GTEx has begun to explore how genetic variations affect a person’s organs at the molecular level. The project aims to understand what genes are turned on and off in different organs, and to further understand how genetic variation might affect different parts of the body. To do this, researchers are cataloging information about DNA and RNA from multiple types of tissue. RNA is similar to DNA, but is shorter lived and can move from the nucleus (where its made) to the cytoplasm (where its read). Information coded within the DNA is copied into messenger RNA, which is then transported out of a cell’s nucleus and used as a template for building proteins. Because proteins affect our traits, measuring RNA can help us understand what genes are influencing traits within each organ. With this knowledge, researchers can combine RNA data and DNA data to see how genetic variants affect genes in different parts of the body, and how that ultimately leads to a physical trait. They also will help clarify if variants identified previously through GWAS have a meaningful impact on the human body. GTEx, and other large projects in genetics like the UK Biobank, will likely have a tremendous impact on humankind over time. In the past decade, over 2,000 GWAS have been performed, which have identified links between genetic variations and over 250 human traits. Results from studies like these can lead to DNA-powered products available directly to you. For example, findings relating to taste receptor variability, sleep preference, and iron metabolism—all of which have made their way into products in the Helix Store—have been studied using GWAS. As data sets from GWAS studies, GTEx, and others are merged, it’s very likely that many more valuable insights will follow.
6 November 2002 A fraction of a second after the Big Bang, all the primordial soup of matter in the Universe was 'broken' into its most fundamental constituents. It was thought to have disappeared forever. However scientists strongly suspect that the exotic soup of dissolved matter can still be found in today's Universe, in the core of certain very dense objects called neutron stars. With ESA's space telescope XMM-Newton, they are now closer to testing this idea. For the first time, XMM-Newton has been able to measure the influence of the gravitational field of a neutron star on the light it emits. This measurement provides much better insight into these objects. Neutron stars are among the densest objects in the Universe. They pack the mass of the sun inside a sphere 10 kilometres across. A sugar cube-sized piece of neutron star weighs over a billion tonnes. Neutron stars are the remnants of exploding stars up to eight times more massive than our Sun. They end their life in a supernova explosion and then collapse under their own gravity. Their interiors may therefore contain a very exotic form of matter. Scientists believe that in a neutron star, the density and the temperatures are similar to those existing a fraction of a second after the Big Bang. They assume that when matter is tightly packed as it is in a neutron star, it goes through important changes. Protons, electrons, and neutrons – the components of atoms - fuse together. It is possible that even the building-blocks of protons and neutrons, the so-called quarks, get crushed together, giving rise to a kind of exotic plasma of 'dissolved' matter. How to find out? Scientists have spent decades trying to identify the nature of matter in neutron stars. To do this, they need to know some important parameters very precisely: if you know a star’s mass and radius, or the relationship between them, you can obtain its compactness. However,no instrument has been advanced enough to perform the measurements needed, until now. Thanks to ESA's XMM-Newton observatory, astronomers have been able for the first time to measure the mass-to-radius ratio of a neutron star and obtain the first clues to its composition. These suggest that the neutron star contains normal, non-exotic matter, although they are not conclusive. The authors say this is a “key first step” and they will keep on with the search. The way they got this measurement is a first in astronomical observations and it is considered a huge achievement. The method consists of determining the compactness of the neutron star in an indirect way. The gravitational pull of a neutron star is immense - thousands of million times stronger than the Earth’s. This makes the light particles emitted by the neutron star lose energy. This energy loss is called a gravitational 'red shift'. The measurement of this red shift by XMM-Newton indicated the strength of the gravitational pull, and revealed the star’s compactness. "This is a highly precise measurement that we could not have made without both the high sensitivity of XMM-Newton and its ability to distinguish details," says Fred Jansen, ESA's XMM-Newton Project Scientist. According to the main author of the discovery, Jean Cottam of NASA’s Goddard Space Flight Center, “attempts to measure the gravitational red shift were made right after Einstein published the General Theory of Relativity, but no one had ever been able to measure the effect in a neutron star, where it was supposed to be huge. This has now been confirmed." Note to editors The result was obtained by observations of the neutron star EXO 0748-676. XMM-Newton detected the light in the form of X-rays. In particular, thanks to analysis of this X-ray radiation, the astronomers were able to identify some chemical elements, namely iron, present in the material surrounding the neutron star. They then compared the distorted signal emitted by the iron atoms in the neutron star with the one produced by iron atoms in the laboratory. In this way, they could measure the actual degree of distortion due to the gravity of EXO 0748-676. The result is published in the 7 November 2002 issue of Nature. The lead author is Jean Cottam, of NASA’s Goddard Space Flight Center (Greenbelt, United States). Other authors are Mariano Mendez, of the National Institute for Space Research, SRON (The Netherlands); and Frits Paerels of Columbia University (New York, United States). XMM-Newton can detect more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999 by an Ariane-5 rocket from French Guiana. It is expected to return data for a decade. XMM-Newton’s high-tech design uses over 170 wafer-thin cylindrical mirrors in three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long uninterrupted views of celestial objects. For more information please contact: ESA Communication Department Media Relations Office Tel: +33(0)1 5369 7155 Fax: +33(0)1 5369 7690 Dr Fred Jansen, ESA XMM-Newton Project Scientist Dr Jean Cottam, NASA Goddard Space Flight Center, Laboratory for High Energy Astrophysics Tel: +1 301 286 1586 For further information:
Haemophilus influenzae type B (Hib) is a kind of bacteria. The Hib bacteria can cause serious disease, such as a deadly brain infection in children. Serious Hib infections are most common in infants 6 to 12 months old. A person does not need to have symptoms to spread the bacteria. Hib is passed on in droplets from the nose or throat of infected people when they cough, talk or sneeze. Symptoms usually appear within 10 days after exposure to Hib. Symptoms depend on the part of the body that is infected. They may include: A person with Hib should begin taking antibiotics right away to prevent brain damage or death. People who have Hib can spread the disease until their antibiotic treatment has started. Many states require proof a child has had the Hib vaccine before starting school. Infants and toddlers should get injections of the vaccine at 2 months, 4 months, 6 months and 12 to 15 months of age. Many infants who get the Hib vaccine are also protected from Hib-related illnesses like meningitis, pneumonia and infections of the blood, bones and joints. Call 911 or go to the emergency room if your child has these signs of an allergic reaction to the Hib vaccine within the first few hours after the shot: Hoarseness or wheezing, hives, paleness, weakness, fast heartbeat or dizziness. Your child may return to school or childcare after their doctor has seen the child and given written permission, and the child feels well enough to take part in daily activities. Haemophilus Influenzae Type B (HIB) (PDF) HH-I-296 2/09 Copyright 2009, Nationwide Children’s Hospital
Symphony means a sonata for orchestra. It has four movements. First movement: Usually fast, and in sonata form. Second movement: Usually slower and more song-like. It could be in sonata form or ternary form, and perhaps with variations. Third movement: Haydn and Mozart wrote a minute in trio at this point. Beethoven later turned this into a Scherzo (A direct translation is joke.) Fourth movement: Fast, often light hearted, perhaps in Rondo form, or sonata form, or with variations. Classical Period: Firstly, the strings play the melody most of the time. In most classical symphonies, each movement is a self-contained composition with its own set of themes. A theme in one movement will only rarely reappear in a later movement. But a symphony is unified partly by the use of the same key in three of its movements. More importantly, the movements balance and complement each other both musically and emotionally. The classical symphony follows form and structure very meticulously. Romantic Period: The Romantic Symphony is an expanded version of the Classical symphony. It is much larger in size and in length with the addition of many more instruments and sometimes more than four movements. During the romantic period, the woodwinds were favoured, and were given more opportunities to play the melody. There are more instruments in the Romantic Symphony as compared to Classical Period. There was freedom of form and design. It was considered to be more personal and emotional. They are much more expressive in terms of harmonization, rhythmic patterns, and dynamics. Many Romantic symphonies were examples of program music, a new instrumental form. Berlioz’s Symphonie Fantastiqueis an example of a Romantic symphony. Haydn’s Symphony 101 in D major: The Clock, movement 1 The strings play the melody mostly. However, the woodwind sometimes plays it. It is in Sonata form and is in 6/8 timing, an unusual timing during that period. The opening is...
Movement is produced and coordinated by several interacting brain centers, including the motor cortex, the cerebellum, and a group of structures in the inner portions of the brain called the basal ganglia. Sensory information provides critical input on the current position and movement of body parts and spinal nerve cells (neurons) help prevent opposing muscle groups from contracting at the same time. Motor cortex: Voluntary (willed) motor commands begin in the motor cortex located on the outer, wrinkled surface of the brain. Movement of the right arm is begun by the left motor cortex, which generates a large volley of signals to the involved muscles. These electrical signals pass along upper motor neurons through the midbrain to the spinal cord. Within the spinal cord, they connect to lower motor neurons that convey the signals out of the spinal cord to the surface of the muscles involved. Electrical stimulation of the muscles causes contraction and the force of contraction pulling on the skeleton causes movement of the arm, hand, and fingers. Damage to or death of any of the neurons along this path causes weakness or paralysis of the affected muscles. Antagonistic muscle pairs: Contraction of the biceps muscle, located on the top of the upper arm, pulls on the forearm to flex the elbow and bend the arm. Contraction of the triceps, located on the opposite side, extends the elbow and straightens the arm. Within the spine, these muscles are normally wired so that voluntary contraction of one is automatically accompanied by blocking of the other. In this way, these antagonist muscles are kept from resisting one another. Spinal cord or brain injury can damage this control system and cause involuntary simultaneous contraction and spasticity, an increase in resistance to movement during motion. Once the movement of the arm is initiated, sensory information is needed to guide the finger to its precise destination. In addition to sight, the most important source of information comes from the "position sense" provided by the many sensory neurons located within the limbs (proprioception). Proprioception is what allows an individual to touch their nose with their finger even with the eyes closed. The balance organs in the ears provide important information about posture. Both postural and proprioceptive information are processed by a structure at the rear of the brain called the cerebellum. The cerebellum sends out electrical signals to modify movements as they progress, organizing the voluntary commands into a tightly controlled pattern. Cerebellar disorders cause ataxia (inability to control the force, fine positioning, and speed of movements). Disorders of the cerebellum may also impair the ability to judge distance so that a person under- or overreaches the target (dysmetria). Tremor during voluntary movements can also result from cerebellar damage. The basal ganglia: Both the cerebellum and the motor cortex send information to the basal ganglia (a set of structures deep within the brain that help control involuntary components of movement). The basal ganglia send output messages to the motor cortex, helping to initiate movements, regulate repetitive or patterned movements, and control muscle tone. Circuits of neurons (nerve cells) within the basal ganglia are very complex. Within the structure, some groups of cells begin the action of other basal ganglia components and some groups of cells block the action. These complicated feedback circuits are not entirely understood. Disruptions of these circuits are known to cause several distinct movement disorders. A portion of the basal ganglia called the substantia nigra sends electrical signals that block output from another structure called the subthalamic nucleus. The subthalamic nucleus sends signals to the globus pallidus, which in turn blocks the thalamic nuclei. Finally, the thalamic nuclei send signals to the motor cortex. The substantia nigra then begins movement and the globus pallidus blocks it. This complicated circuit can be disrupted at several points. For instance, loss of substantia nigra cells, as in Parkinson's disease, increases blocking of the thalamic nuclei, preventing them from sending signals to the motor cortex. The result is a loss of movement (motor activity), a characteristic of Parkinson's. In contrast, cell loss in early Huntington's disease decreases blocking of signals from the thalamic nuclei, causing more cortex stimulation and stronger but uncontrolled movements. Disruptions in other portions of the basal ganglia are thought to cause tics, tremors, dystonia, and a variety of other movement disorders, although the exact mechanisms are not well understood. Movement disorders can result from causes including age-related changes, environmental toxins, genetic disorders (such as Huntington's disease and Wilson disease), medications (antipsychotic drugs), metabolic disorders (hyperthyroidism and diabetes), Parkinson's disease, and stroke (neurological damage due to lack of blood supply to the brain). Some movement disorders, including Huntington's disease and inherited ataxias, are caused by inherited genetic defects. Some diseases that cause focal dystonia, or sustained muscle contraction limited to a particular muscle group, are inherited, but others are caused by trauma. The cause of most cases of Parkinson's disease is unknown, although genes have been found for some familial forms. Diagnosis of movement disorders involves taking a family history, a history of symptoms, and performing a physical examination (including neurological examination) and various tests (including blood tests and imaging tests). Blood tests: Blood tests may include a complete blood count (CBC), a creatine kinase test, and a DNA analysis (to determine if the disorder is genetic). In some cases, a cerebrospinal fluid (CSF) analysis also is performed. Cerebrospinal fluid analysis involves performing a spinal tap or lumbar puncture. In this procedure, about two tablespoons of cerebrospinal fluid is drawn into a needle inserted between two lumbar vertebrae and then examined under a microscope. This procedure is usually performed in a hospital or clinic under local anesthesia, although general anesthesia can be used. Side effects include pain and tenderness in the area of puncture. Imaging tests: Imaging tests, including computed tomography (CT scan), magnetic resonance imaging (MRI scan), and positron emission tomography (PET scan), may be used to detect damage (such as shrinkage) in the basal ganglia, structural abnormalities, and stroke (neurological damage due to a lack of oxygen to the brain). Other imaging tests: An electromyogram (EMG) and an electroencephalogram (EEG) also may be performed. These tests are used to monitor electrical activity within the body and can help detect nerve and muscle disorders. EMG involves placing electrodes on the skin (surface EMG) or into the muscle (intramuscular EMG) to record electrical activity of the muscle. In an EEG, electrodes are attached to the scalp and connected to a machine that records electrical impulses in the brain. Muscle biopsy: A muscle biopsy may also be performed to distinguish between nerve and muscle disorders. This procedure, which is performed under local anesthesia, involves making a small incision and removing a sample of muscle for microscopic evaluation. Following the procedure, patients may experience minor pain and bruising at the biopsy site for about one week. signs and symptoms Symptoms of movement disorders often vary and fluctuate. The severity of symptoms may be affected by factors such as anxiety, fatigue, medications, and stress. Some movement disorders cause hyperkinesia (excessive spontaneous movement or abnormal involuntary movement) and others cause hypokinesia (absent or reduced ability to perform purposeful movement). Abnormal movements may be rhythmical (essential tremor) or irregular and may be rapid and jerky (tics) or slowed and sustained (Parkinson's disease, dystonia). In most cases, irregular movement cannot be consciously controlled or suppressed. Akathesia: Akathesia is restlessness and a desire to move to relieve uncomfortable sensations. Sensations may include a feeling of crawling, itching, stretching, or creeping, usually in the legs. Athetosis. Atheitosis is the slow, writhing, continuous, uncontrollable movement of the arms and legs. Ballism: Ballism is like chorea, but the movements are much larger, more explosive, and involve more of the arm or leg. This condition, also called ballismus, can occur on both sides of the body or on one side only (hemiballismus). Chorea: Chorea is rapid, nonrhythmic, usually jerky movements, most often in the arms and legs. Dystonia: Dystonia is sustained muscle contractions, often causing twisting or repetitive movements and abnormal postures. Dystonia may be limited to one area (focal) or may affect the whole body (general). Focal dystonias may affect the neck (cervical dystonia or torticollis), the face (one-sided or hemifacial spasm, contraction of the eyelid, or blepharospasm, contraction of the mouth and jaw or oromandibular dystonia, simultaneous spasm of the chin and eyelid, or Meige syndrome), the vocal cords (laryngeal dystonia), or the arms and legs (writer's cramp, occupational cramps). Dystonia may be painful as well as incapacitating. Myoclonus: Myoclonus is a sudden, shock-like muscle contraction. Myoclonic jerks may occur singly or repetitively. Unlike tics, myoclonus cannot be controlled even briefly. Tics: Tics are involuntary, rapid, nonrhythmic movements or sounds. Tics can be controlled briefly. Tremor: Tremors are involuntary (uncontrollable) shaking of a body part. Tremors may occur only when muscles are relaxed or they may occur only during an action or while holding an active posture. Bradykinesia: Bradykinesia is slowness of movement. Freezing: Freezing is the inability to begin a movement or involuntary stopping of a movement before it is completed. Postural instability: Postural instability is the loss of ability to maintain upright posture caused by slow or absent righting reflexes. Rigidity: Rigidity is an increase in muscle tension when an arm or leg is moved by an outside force. Complications of movement disorders depend on the individual and the particular condition that is present. Mental and emotional problems: As well as movement difficulties, there are a variety of behavioral and psychological difficulties that are experienced by many, though not all, individuals with movement disorders. The most frequently reported behavioral problems are attention deficits, obsessions, compulsions, impulsivity, irritability, aggression, immaturity, drug and alcohol abuse and addiction, self-injurious behaviors, and depression. Some individuals with movement disorders (such as Tourette's syndrome) have significant problems with labile (rapidly changing) emotions, impulsivity, and aggression directed to others. Temper fits, include screaming, punching holes in walls, threatening others, hitting, biting, and kicking, are common in such patients. Along with psychiatric conditions, individuals with movement disorders, such as Huntington's disease, may be more susceptible to suicidal thoughts. Other health complications: Some movement disorders, such as Huntington's disease, can make the individuals susceptible to life-threatening complications related to this disease, such as pneumonia (a bacterial infection in the lungs and respiratory system) and heart disease (including heart attack, congestive heart failure or CHF, and atherosclerosis or hardening of the arteries) are the two leading causes of death for individuals with Huntington's disease. Additionally, Huntington's disease patients have higher incidence of choking and respiratory complications, gastrointestinal diseases (such as cancer of the pancreas), and suicide than the population without the condition. Ocular (eye) complications (including nystagmus or involuntary eye movements) may be present in some individuals with movement disorders, including Wernicke-Korsakoff syndrome (results from thiamin or vitamin B1 deficiency). Age: Parkinson's disease affects about one percent of people older than 65 and 0.4% of those older than 40. The mean age at onset is about 57 years of age. Rarely, Parkinson's disease begins in childhood or adolescence (juvenile parkinsonism). Tourette's syndrome usually becomes apparent in children between ages two and 15, with approximately 50% of patients affected by age seven. The age of symptom onset is typically before the age of 18. Genetics: Some movement disorders are due to inheriting genes that carry the genetic condition. One or both parents can have the gene and pass it on to their children. Some individuals may carry the gene but not exhibit symptoms of the neurological condition. Examples of movement disorders that are genetically inherited include dystonia musculorum deformans (a rare dystonia characterized by movements resulting in bizarre postures), Huntington's disease (results in chorea or uncontrolled movements, loss of intellectual faculties, and emotional disturbance), and Tourette's syndrome (multiple motor and vocal tics or repeated muscle contractions). Sex: The sex of the individual predisposes certain people to movement disorders. In Tourette's syndrome, at-risk males are more likely to have tics and at-risk females are more likely to have obsessive-compulsive symptoms. Seven of every 10 girls who inherit the gene, and nearly all boys who inherit it, will develop symptoms of Tourette's syndrome. Huntington's disease affects both sexes equally.
Kindergarten Worksheets > Alphabet Parade > Letter B These worksheets are designed to introduce your child to the letter B. Beginning with the first worksheet in the collection, the worksheets progress from beginning (identifying the letter) to intermediate (identifying words that begin with the letter B sound) to complex (learning to write the letter B). B - Coloring B - Scramble B - Letter in Word B - Sound in Picture B - Tracing b - Tracing Activity suggestions to supplement the Letter B alphabet worksheets - Blow bubbles to celebrate the letter B. Then write a large “B” on a piece of construction paper. Give your child some circle stickers and ask him to place the “bubbles” over the large “B” that you have written. - Create a “B” day breakfast! Serve bananas, blueberries, bran cereal, bran muffins, biscuits or bacon. As your child eats, ask him to say aloud the name of each food. - Use bathtub crayons to write the letters B and b on the tub wall. Ask your child to write additional B and b letters, or to trace over your letters. Remind him that bathtub, bubbles and bath all begin with the B sound. - Create silly sentences with your child that emphasizes the B sound. For example, “Betty, Bob and Billy bought a bear named Bobo and took it to Boston. They got Bobo out of his bed and went on the bus.” Tips for using the Letter B tracing letters worksheets - The key to writing a neat letter B is to lift the pencil once. After drawing the straight line down, direct your child to lift the pencil, go back to the top and draw two half circles without picking his pencil up in the middle. - The lowercase letter b is made in one smooth movement. Direct your child to draw a straight line down and pause. Then, without lifting the pencil, change direction and make the small curve upward to complete the b.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2001 February 6 Explanation: The first controlled descent of a spacecraft onto an asteroid is scheduled to occur next week. The robot spacecraft NEAR-Shoemaker has been orbiting asteroid Eros for nearly one year On February 12, before maneuvering fuel wanes, NASA will command the craft to descend right down onto the surface. Although the spacecraft is not expected to survive the impact, it is hoped that it can transmit photographs showing surface details as small as 10 centimeters during the descent. The touchdown site, shown above by the yellow circle, is on the edge of the large saddle shaped feature known as Himeros, and near the boundary between two distinct types of surface terrain. Authors & editors: Jerry Bonnell (USRA) NASA Technical Rep.: Jay Norris. Specific rights apply. A service of: LHEA at NASA/GSFC & Michigan Tech. U.
In this tutorial you will be learning about the Linnaean system of classification used in the biological sciences to describe and categorize all living things. The focus is on finding out how humans fit within this system. In addition, you will discover part of the great diversity of life forms and come to understand why some animals are considered to be close to us in their evolutionary history. How many species are there? This is not an easy question to answer. About 1.8 million have been given scientific names. Thousands more are added to the list every year. Over the last half century, scientific estimates of the total number of living species have ranged from 3 to 100 million. The most recent methodical survey indicates that it is likely to be close to 9 million, with 6.5 million of them living on the land and 2.2 million in the oceans. Tropical forests and deep ocean areas very likely hold the highest number of still unknown species. However, we may never know how many there are because it is probable that most will become extinct before being discovered and described. The tremendous diversity in life today is not new to our planet. The noted paleontologist Stephen Jay Gould estimated that 99% of all plant and animal species that have existed have already become extinct with most leaving no fossils. It is also humbling to realize that humans and other large animals are freakishly rare life forms, given that 99% of all known animal species are smaller than bumble bees. Why should we be interested in learning about the diversity of life? In order to fully understand our own biological evolution, we need to be aware that humans are animals and that we have close relatives in the animal kingdom. Grasping the comparative evolutionary distances between different species is important to this understanding. In addition, it is interesting to learn about other kinds of creatures. When did scientists begin classifying living things? Before the advent of modern, genetically based evolutionary studies, European and American biology consisted primarily of taxonomy , or classification of organisms into different categories based on their physical characteristics and presumed natural relationship. The leading naturalists of the 18th and 19th centuries spent their lives identifying and naming newly discovered plants and animals. However, few of them asked what accounted for the patterns of similarities and differences between the organisms. This basically nonspeculative approach is not surprising since most naturalists two centuries ago held the view that plants and animals (including humans) had been created in their present form and that they have remained unchanged. As a result, it made no sense to ask how organisms have evolved through time. Similarly, it was inconceivable that two animals or plants may have had a common ancestor or that extinct species may have been ancestors of modern ones. One of the most important 18th century naturalists was a Swedish botanist and medical doctor named Karl von Linné. He wrote 180 books mainly describing plant species in extreme detail. Since his published writings were mostly in Latin, he is known to the scientific world today as Carolus Linnaeus , which is the Latinized form he chose for his name. In 1735, Linnaeus published an influential book entitled Systema Naturae in which he outlined his scheme for classifying all known and yet to be discovered organisms according to the greater or lesser extent of their similarities. This Linnaean system of classification was widely accepted by the early 19th century and is still the basic framework for all taxonomy in the biological sciences today. The Linnaean system uses two Latin name categories, genus and species , to designate each type of organism. A genus is a higher level category that includes one or more species under it. Such a dual level designation is referred to as a binomial nomenclature or binomen (literally "two names" in Latin). For example, Linnaeus described modern humans in his system with the binomen Homo sapiens , or "man who is wise". Homo is our genus and sapiens is our species. genus genus species species species species Linnaeus also created higher, more inclusive classification categories. For instance, he placed all monkeys and apes along with humans into the order Primates . His use of the word Primates (from the Latin primus meaning "first") reflects the human centered world view of Western science during the 18th century. It implied that humans were "created" first. However, it also indicated that people are animals. order family family genus genus genus genus species species species species species species species species While the form of the Linnaean classification system remains substantially the same, the reasoning behind it has undergone considerable change. For Linnaeus and his contemporaries, taxonomy served to rationally demonstrate the unchanging order inherent in Biblical creation and was an end in itself. From this perspective, spending a life dedicated to precisely describing and naming organisms was a religious act because it was revealing the great complexity of life created by God. This static view of nature was overturned in science by the middle of the 19th century by a small number of radical naturalists, most notably Charles Darwin. He provided conclusive evidence that evolution of life forms has occurred. In addition, he proposed natural selection as the mechanism responsible for these changes. Late in his life, Linnaeus also began to have some doubts about species being unchanging. Crossbreeding resulting in new varieties of plants suggested to him that life forms could change somewhat. However, he stopped short of accepting the evolution of one species into another. Why do we classify living things today? Since Darwin's time, biological classification has come to be understood as reflecting evolutionary distances and relationships between organisms. The creatures of our time have had common ancestors in the past. In a very real sense, they are members of the same family tree. The great diversity of life is largely a result of branching evolution or adaptive radiation. This is the diversification of a species into different lines as they adapt to new ecological niches and ultimately evolve into distinct species. Natural selection is the principal mechanism driving adaptive radiation. Copyright © 1998-2012 by Dennis All rights reserved.
Bornean Orang-utan Classification and Evolution The Bornean Orang-utan is a large primate species that is found inhabiting the humid tropical jungles of Borneo. Also known as the Red Ape, the Bornean Orang-utan is the second largest ape species in the world (after the Gorilla) and is the largest tree-dwelling animal on the planet. Although the Bornean Orang-utan is closely related to the great apes found in Africa, they differ greatly in their behaviour with the biggest difference being that the Bornean Orang-utan is largely solitary where other ape species tend to adopt complex social hierarchies. Until recently there was thought to only be one Orang-utan species but recent genetic research has shown that there is in fact two species of Orang-utan which are the Bornean Orang-utan and the Sumatran Orang-utan, which is slightly smaller in size and tends to be more sociable than it's larger cousin. There are considered to be three different sub-species of the Bornean Orang-utan, which although are similar in appearance, are differentiated by the areas of the island that they occupy. They are the Northwest Bornean Orang-utan, the Central Bornean Orang-utan and the Northeast Bornean Orang-utan. Bornean Orang-utan Anatomy and Appearance The Bornean Orang-utan is covered in patchy red or orange hair with it's coarse grey skin being visible in some places. As they are largely arboreal mammals, the Bornean Orang-utan has a number of adaptations that help it when in the canopy including having feet that can grip as effectively as it's hands, and arms that can grow to a span of more than two meters and are actually 30% longer than their legs. The face of the Bornean Orang-utan is bare and displays the grey or black colour of their skin. Mature males also develop fleshy cheek pouches which are made up of fat deposits under the skin, along with throat poaches that are able to produce a deep, resonating sound through the forest. Both male and female Bornean Orang-utans are specially designed for opening and eating fruits with dexterous hands and feet for peeling and large flat teeth that help to grind down harder seeds and tree bark. Bornean Orang-utan Distribution and Habitat The Bornean Orang-utan is natively found on the island of Borneo where it inhabits areas of dense primary forest, mainly in the lowlands and valleys. Although they can be found at elevations of up to 1,500 meters they tend to prefer the lush slopes further down due to the higher abundance and variety of food. Although the Bornean Orang-utan (and indeed the Sumatran Orang-utan) were once widespread throughout south-east Asia, they are today confined to the two islands which they named after but are seriously vulnerable in their natural surroundings due to logging and forest fires which have decimated much of their once vast native regions. Due to the fact that the Bornean Orang-utan spends nearly all of it's life high in the tree canopy, they rely on these dense and rich jungles to survive and with less and less of their natural habitats remaining, they are being forced into more smaller and more isolated regions away from the increasing levels of Human activity. Bornean Orang-utan Behaviour and Lifestyle Unlike the other great ape species, the Bornean Orang-utan is largely solitary with the exception of mother and infant pairs and the gathering of a number of individuals around heavily laden fruit trees. Bornean Orang-utans spend much of their days sitting and eating in the canopy before constructing a nest by folding leafy branches over, where they sleep at night. Bornean Orang-utans move slowly through the steamy forests and as they are too heavy to jump, they rely on swinging tree branches back and forth until they can get close enough to grab onto the next one. Despite only travelling just over half a mile a day, Bornean Orang-utans can occupy vast home ranges that are loosely shared with other individuals with males having breeding rights with any female that enters their patch, marking their presence with deep, loud calls which echo through the trees. Bornean Orang-utan Reproduction and Life Cycles The Bornean Orang-utan is known to breed year round but these slow-developing and maturing animals are not able to reproduce until they are often nearly 15 years old. After a gestation period that lasts for up to 9 months, the female Bornean Orang-utan gives birth to a single infant which clings onto it's mother's fur and is completely dependent on her for up to 10 years. Despite the young Bornean Orang-utans being weaned when they are around three years old, offspring continue to shadow their mother so as to learn about what to eat and where to find it and also for safety. Eventually leaving her to establish their own territory when they are at least eight years old, young females tend to remain close to their mother whereas young males can roam the forest for a long time before they finally find a patch of their own. Bornean Orang-utans tend to live for up to 35 years in the wild but can reach almost double that age in captivity. Bornean Orang-utan Diet and Prey The Bornean Orang-utan is technically an omnivorous animal which means that they find and eat a variety of both plant and animal matter. Despite this, Bornean Orang-utans love fruit with around 60% of their diet being comprised of a wide variety of both ripe and unripe fruits including mangoes, durian, figs and lychees. In the tropics though, different trees bare their fruits at different times of the year so Bornean Orang-utans must make a mental note of where the fruit trees are and when their fruits ripen. In order to supplement their diet though, Bornean Orang-utans also eat a range of plant matter including young shoots and leaves along with insects, eggs and small vertebrates such as Lizards on occasion. Although in areas where their is a rich and abundant supply of food Bornean Orang-utans are known to congregate together to feed, one of the reasons why they are so solitary is that if they lived together in a group in one area, there simply would not be enough food to go around. Bornean Orang-utan Predators and Threats Historically Bornean Orang-utans would hardly ever come down to the ground in fear of being preyed upon by large carnivores like Tigers, Bears and Clouded Leopards but with the extinction of the Tiger particularly throughout much of the island males are known to spend around 5% of their time on the forest floor. However, 40,000 years ago a new threat emerged in the form of modern Humans that hunted the Bornean Orang-utan to extinction in numerous parts of their once vast natural range. Today they are protected by law but infants are still captured for the exotic pet trade and the mothers are often killed in the process. The biggest threat though to Borneo's remaining Orang-utan populations is habitat loss in the form of deforestation for logging or to clear land for farming and agriculture, primarily to make way for palm oil plantations. Bornean Orang-utan Interesting Facts and Features The sound that male Bornean Orang-utans make to mark their territories comes from their developing throat pouch and is so booming that it can travel for more than a mile throughout the forest, to not only attract females but also to intimate rival males. Bornean Orang-utans are unique amongst great apes as their arboreal lifestyle has led to their limbs having more mobility than other species, allowing them to negotiate around tricky branches more easily. In the same way however to other great ape species, Bornean Orang-utans have bee observed using tools to help them in their daily lives. Seemingly dependent on where the individual lives, skills are passed onto infants from their mothers with sticks being used to extract termites and honey and even large leaves are used as a form of umbrella to keep the Bornean Orang-utan dry. Bornean Orang-utan Relationship with Humans Since their arrival in south-east Asia modern Humans have been fascinated by this slow-moving and majestic mammal with their name in the native Malay language meaning "man of the forest" or "forest people". Bornean Orang-utans are remarkably similar to us both in their appearance and behaviour with these highly intelligent creatures having evolved perfectly to their tropical, tree-dwelling lives. However, the hunting of the Bornean Orang-utan and the deforestation of it's once vast natural habitat has led to drastic declines in their population numbers particularly over the past century. Adults are often killed if they are seen in or close to plantations when looking for food and their young are captured to be sold into the exotic pet trade, despite their heavy legal protection. Bornean Orang-utan Conservation Status and Life Today Today, the Bornean Orang-utan is listed by the IUCN as a species that is Endangered in it's natural environment and is therefore severely threatened from extinction in the near future. The loss of their historic, unique and incredibly bio-diverse habitats has led to a 92% drop in their population numbers in the past 100 years and if things continue the way they are going, it will not be long before they have disappeared from the wild forever. Rehabilitation programmes exist throughout the island and so far seem to be having relative success but with deforestation (now even in protected areas) for logging and to clear land to make way for palm oil plantations, population numbers can only be expected to continue to fall.
Several different factors can help to identify the species of a tick, including size, color, the length of its mouth parts, location and time of the year. Although there are many different species of ticks, these factors are usually quite reliable in determining the specific species.Continue Reading The first factor to look for is the shape and color of the tick's shield, also known as a scutum. Each species of tick has a different shape and color or pattern on its scutum. For instance, those belonging to the Ixodes genus, which includes deer ticks, typically have a solid-colored brown or black shield, while most other genera have uniquely patterned shields. Although these factors are easier to see if the tick hasn't eaten, it is usually still possible to spot the signs even on an engorged tick. Size can also help to determine the species of tick, as most dog ticks are larger than deer ticks. Another factor that can help identify a deer tick is the lack of festoons, which are small grooves that are found on the back of all other species. Looking at the length of the mouth parts may also help, as dog ticks and other Dermacentor ticks have much shorter mouths than the other groups. The location and time of the year should also help identify the species, as only certain species are active during given times of the year.Learn more about Bugs
Circular motion and gravity Working anything out about orbits involves two basic ideas: circular motion and gravity. For something to go in a circle it needs a centripetal force. This could be the tension in the string tied to a bucket of water as you swing it around your head, or it could be the friction on the tyres of a car as it corners. For a satellite the centripetal force is provided by the Earth's gravitational attraction. So the starting point for any calculation is: R = total distance between the Earth and satellite G = gravitational constant M = mass of the Earth m = mass of satellite v = speed of satellite Another useful starting point is to look at the acceleration due to gravity (or the force per unit mass - otherwise known as gravitational field strength) where you are. Even when they are in orbit, the satellites are accelerated by gravity: where g' is the gravitational field strength at that orbital height - which is much less as you move further away. For example, for a geostationary satellite: The acceleration due to gravity decreases as the satellite's orbit gets bigger. This is why they can afford to go more slowly without risking being pulled back down to Earth. Wherever a satellite is orbiting, the centre of its orbit has to be the centre of the Earth; this defines the direction of the force exerted by the Earth. Lose weight - go to the equator You weigh less when standing on the equator than you do when standing on the poles. Firstly the radius of the Earth north-south is less than east-west (the Earth is an oblate spheroid), so you are nearer to the centre of the earth. Secondly you are slightly 'thrown out' from the Earth by its spin. In your frame of reference you experience a centrifugal force which is away from the centre of your circular motion. This is the same as the feeling of being thrown outwards on spinning fairground Astronauts on the orbiting space station are weightless. This is not because there is no pull of gravity on them. It is because the floor of the space station does not push back upon them - they experience no reaction force. They are in free fall as the space station is in free fall. In fact they train for weightlessness by going up in a large training jet which then free falls. The astronauts and the jet fall at the same rate (accelerating at 9.8m/s2 as they are near to the Earth). The astronauts never catch up with the jet so it never exerts a reaction force on them - this is how they feel weightless.
Children start developing their mathematical skills while they are still babies exploring their environment and continue into their preschool years. By the time they are learning formal mathematical concepts in the first grade, the foundation for success is already set. Here are some tips for how to teach maths to preschoolers at school or at home by using hands-on activities and following a concrete-pictorial-abstract approach. What are Early Maths Skills? Early maths refers to the mathematical concepts and skills a child builds informally during the first few years. These are also called pre-maths skills or early numeracy skills. It is essential to first develop these before trying to introduce maths concepts that are too advanced. When introducing your child to maths, you may immediately think of numbers and start with counting, recognizing the numbers and adding or subtracting them. While learning to count to 10 is fun for young kids, understanding the value of these numbers and what they represent is an advanced skill. If you ask a very young child to count 5 objects by touching them one at a time, you might see them count the same object twice or skip over some. It’s important to first understand how children learn mathematical concepts and then help them develop early mathematical skills. How Children Learn Maths: The Concrete Pictorial Abstract Approach The three stages of learning any mathematical concept are concrete, pictorial and abstract. The Concrete Stage In the concrete stage, children need to physically experience a concept. They need to develop an understanding of one item by holding one block. By playing with concrete objects, children form the concept that there can be one object, multiple objects, less objects, more objects, etc. Many mathematical processes are going on while children build a tower of blocks or make mud cakes in the sand pit. They learn concepts such as more, less, one more, not enough, how many, plenty, fewer, take away and add on. Children compare objects and learn that a value can be attached to objects. The Pictorial Stage In the pictorial stage, which follows the concrete stage, children are able to see a picture of objects and understand that it represents real objects. For example, a child can look at a picture and understand that the 4 leaves represent 4 actual leaves. Later on, a child can see a dice with 4 dots on it and assign the value 4, knowing that the dots could hypothetically represent any object. They would then be able to add the 4 dots on one dice to the 3 dots on another and say there are 7 dots altogether. The Abstract Stage This is the final stage of understanding a mathematical concept. It means that a child can look at a sum, e.g. 4 + 3, written in number symbols, and add them without concrete objects or pictures. The child has matured enough to understand that the symbols 4 and 3 represent a number of objects to be added. This post contains affiliate links for educational products that I personally recommend. If you purchase through one of them, I earn a commission at no extra cost to you. Read the terms and conditions for more details. Are Preschoolers In the Concrete, Pictorial or Abstract Stage? Preschoolers are mostly in the concrete stage. In fact, up until the third or fourth grade, any teacher worth their salt will still introduce a new concept in a concrete way before moving on to books or worksheets with examples to solve. When children understand a concept concretely, it is then much easier to solve abstract problems. This means that in the preschool years, trying to push a child to count pictures of objects or understand the value of the number symbols is premature and will cause frustration. You may want to expose your child to numbers (e.g. playing with wooden numbers like these or magnetic number tiles) or rhymes that teach counting, but do not expect your child to understand the value of these numbers yet. How to Teach Maths to Your Preschooler: 15 Simple Activities The best method for teaching mathematics in early childhood is through their main medium of learning – play. This means that during these early years children don’t need formal lessons, activity sheets and workbooks. Maths for preschoolers should be all about fun. Here is a list of just a few basic everyday opportunities that double up as the perfect preschool maths activities. 1. Play With Shapes Playing with foam or wooden shapes familiarises your child with basic geometric shapes, as well as their properties. It teaches shape recognition. 2. Make Shape Pictures Cut basic shapes out of coloured paper and make a picture out of them. Children learn to join 2D shapes together to make different forms. Tangrams (like these) are great for making pictures with shapes. 3. Build Puzzles Puzzles are excellent for developing visual perception and will build a child’s understanding of geometry. Choose good quality wooden puzzles with a wooden tray. 4. Play With Pegboards Pegboards are another great activity for building maths skills in preschoolers. They develop number concepts and geometrical knowledge. 5. Build Forts This may not seem like a maths activity, but building forts and other structures and climbing inside them is the first step in a child learning about space and shape. These early play sessions are a must. 6. Use Manipulatives There are so many benefits of playing with blocks that children should have opportunities to play with blocks and all kinds of manipulatives daily. Playing with blocks is the first step in building a number concept and every child should have a good set of wooden blocks at home. This set is perfect for the classroom or home. 7. Make Mud Pies When children play in the sandpit and make mud pies and other structures, they begin to use terms such as “I need to make another one,” “There are 3 cakes” or “I made one for each of us.” 8. Learn Counting Songs Counting songs are a fun way for a young child to learn to count forwards and backwards. This is known as rote counting. They also learn about increasing and decreasing quantity in songs such as Five Green Bottles. 9. Play With Numbers Let your child play with foam, rubber, wooden or plastic numbers in the bath or on a magnetic board. Because they are physical objects, your child can touch them and feel their shapes. This is far more meaningful to a young child than looking at numbers on an activity page. With time, they will naturally learn to recognize them and know how they are formed. 10. Make Playdough Numbers Playdough is one of the best substances out there, with some amazing benefits. Get kids to mould the numbers out of playdough. This sensory activity will imprint the numbers in your child’s mind far quicker than trying to write the numbers on paper. 11. Play With Containers Provide containers of different sizes and shapes and let your child discover the basics of capacity while having fun in the bath or sandpit. Baking is a great mathematical experience. Let your child be involved in measuring the ingredients to introduce them to units of measurement and quantities. 12. Measure Objects Ask your child to measure certain objects – such as a book, table or room – using body parts like hands or feet, and later objects, such as a block or book. Children must first learn to measure length using non-standard items before they can be introduced to standard measurements. 13. Talk About Time Find opportunities daily to talk about time. Use the daily routine as a starting point. Discuss concepts such as the time of day (morning, afternoon) as well as clock time (“I’ll pick you up at 12 ‘o clock after storytime”). 14. Play With Objects Give kids different objects and ask them to feel which are heavy or light and to compare the weight of different objects. Use a balancing scale (or make one) and place various household items on it. 15. Problem Solve Problem solving can be the most, um… problematic, of all the maths tasks! Children in the grades often struggle to visualize problems and what they actually mean. They often resort to guessing operations (e.g. it says more so I should add) without having any idea what the problem is actually about and how, when visualized, the solution is usually so logical. The best way to prepare children for problem solving is to give non-stop opportunities to actually solve real problems. Encourage children to develop critical thinking skills. You don’t necessarily need to be giving mathematical problems, just general problems that require training the brain to think, and think outside the box. Allow many opportunities to: - Build puzzles - Solve brainteasers such as tangram puzzles - Solve riddles - Play games that require thinking - Play with construction toys (e.g. figuring out how to make a bridge that doesn’t fall) - Discuss problems and solutions during storytime - Ask children for solutions to everyday problems As you can see, most play experiences have hidden opportunities for learning maths. Learn to recognize them and use them to consciously teach certain skills. Remember to introduce new vocabulary and ask questions constantly during play. Introduce words such as: heavier, lighter, longer, shorter, earlier, later, more, less, more than, less than, fewer, extra, not enough, altogether, left, another, full, empty, matching, same, different. I hope you’ve enjoyed reading this article and have some new ideas to try. Get FREE access to Printable Puzzles, Stories, Activity Packs and more! 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Posted on by Dr. Francis Collins Everybody knows that it’s important to stay alert behind the wheel or while out walking on the bike path. But our ability to react appropriately to sudden dangers is influenced by whether we feel momentarily tired, distracted, or anxious. How is it that the brain can transition through such different states of consciousness while performing the same routine task, even as its basic structure and internal wiring remain unchanged? A team of NIH-funded researchers may have found an important clue in zebrafish, a popular organism for studying how the brain works. Using a powerful new method that allowed them to find and track brain circuits tied to alertness, the researchers discovered that this mental state doesn’t work like an on/off switch. Rather, alertness involves several distinct brain circuits working together to bring the brain to attention. As shown in the video above that was taken at cellular resolution, different types of neurons (green) secrete different kinds of chemical messengers across the zebrafish brain to affect the transition to alertness. The messengers shown are: serotonin (red), acetylcholine (blue-green), and dopamine and norepinephrine (yellow). What’s also fascinating is the researchers found that many of the same neuronal cell types and brain circuits are essential to alertness in zebrafish and mice, despite the two organisms being only distantly related. That suggests these circuits are conserved through evolution as an early fight-or-flight survival behavior essential to life, and they are therefore likely to be important for controlling alertness in people too. If correct, it would tell us where to look in the brain to learn about alertness not only while doing routine stuff but possibly for understanding dysfunctional brain states, ranging from depression to post-traumatic stress disorder (PTSD).
Ἀνδρεία, Τόλμα, Θράσος - Male and Female Courage in Classical Greek Literature Sammanfattning: This thesis discusses the differences in the descriptions of and the attitudes towards female courage in the literature of the Classical period. Male authors of this period wrote extensively of the martial and virtuous courage of men, andreíā, yet in some instances instead labelled courage as tólma or thrásos. Tólma and thrásos are even more commonly used in descriptions of female courage, audacity or rashness. How these three words could be used in relation to men and women is discussed, and the fundamental belief of the Classical period that women were not capable of courage is encountered. As courage was outside the nature, phúsis, of a woman, her actions were always more likely to be viewed as tólma or thrásos. To what extent the literature of the period can reflect the lived experience of the ancient Athenian is unknown. However, it is concluded that literary works both impact and are impacted by social and cultural values, such as the view that women should not or could not be courageous. HÄR KAN DU HÄMTA UPPSATSEN I FULLTEXT. (följ länken till nästa sida)
What are invasive non-native species? Over 2,000 plants and animals have been introduced to GB from all over the world by people. These are known as non-native species. Most are harmless, indeed the majority of our agricultural species (wheat, barley, sheep etc) are not native to GB, but around 10-15% become invasive non-native species which spread and have a harmful impact. Invasive non-native species are one of the top five drivers of global biodiversity loss. Here in GB they threaten the survival of native wildlife, damage our natural ecosystems, cost the economy nearly £2 billion a year, and can even harm our health and interfere with activities we enjoy. What is Invasive Species Week? Each year organisations across the UK, Ireland, Jersey, Guernsey and Isle of Man work together to raise awareness of the impacts of invasive non-native species and the simple things that everyone can do to help protect the environment. How can I take part? The next Invasive Species Week will take place from the 15th - 21st May 2023. Email us to join our mailing list for details. If you'd like to take part, visit our supporter page for suggestions and free materials to help you. How can I protect the environment? \|Keep any boats, clothing, footwear and equipment used in water free of invasive non-native species – remember to Check Clean Dry after use.\| \|Be Plant Wise and don't let your garden, pond, or aquarium plants enter the wild.\| \|Take care of your pets, never release them or allow them to escape into the wild. It’s cruel and could harm other wildlife.\| \|Look out for Asian hornet and other alert species and record your sightings. Read more on Asian hornet and how to report sightings, find free ID sheets for invasive non-native species.\| \|If you enjoy being outside why not volunteer with a Local Action Group working on invasive species management.\| Invasive Species Week 2022 From 16-22 May over 260 organisations took part in raising awareness, and 92 events were held. You can still find links to all blogs, videos and other resources that were published during the week, and visit @InvasiveSp (external link) or #INNSweek on Twitter to catch up on the action online.
A+ Grade 3 contains hundreds of exciting exercises in 5 key skills development sections. These proven skills are essential to equip your child with the fundamental knowledge that is necessary for the primary educational phase. The skills developed include addition, subtraction, multiplication (times tables), mental division, reading, spelling, logical reasoning, memory recall, concentration and basic computer skills. All the activities are presented in fun and engaging game play. The games are made to be understood by kids and is designed to be played without adult assistance. The result is that you not only develop the child’s intellect and fundamental skills, but also a sense of self-confidence.
Correct nutrition can help alleviate the adverse effects of both cancer and the ensuing treatment Cancer devastates human body, and so do the chemotherapeutic treatment methods deployed to get rid of it. The strong medicines and corrosive chemotherapies weaken the body beyond healing. They make the recuperation process even more difficult. But, maintaining a healthy and nutritious diet throughout the recovery period and thereafter is a proven mechanism to cope with the adverse effects of cancer. Also, a balanced nutrition has several other perks on health overall. Cancer has an undeniable nexus with the exponentially increasing traits of lifestyle disorder. Smoking, alcohol consumption, eating disorder, stress, lack of sleep, sedentary lifestyle, lack of physical activities, prolonged exposure to hazardous radiation - all these are the most common causes of lifestyle disorder. All of them have the potential to trigger the risk of getting cancer. This is why several cancer treatment repertoires often proactively include cutting off of many of these activities. Amidst these never ending examples of lifestyle disorder, a nutritious and balanced diet plays a pivotal role in keeping the risks at bay. It rejuvenates the human body by strengthening the immune system and thus reduces the susceptibility to infections and the possibility of succumbing to several other life threatening ailments including heart conditions. Treatment of cancer often renders the affected human body very highly susceptible to multiple serious diseases. Foodborne illnesses are very common. Neutropenia is another health condition worth mentioning which exhibits an abnormal low count of white blood cells (Neutrophills). Microscopic organisms like fungi and gram-negative bacteria, available in food and drinks, often pose serious threats to the Neutropenic patients. Safe preparation and handling of foods is more important than restricting intake of specific food groups, as balanced diet and nutrition is important for coping with chemotherapy and other kinds of cancer treatments. The diet concerns include Chemotherapy and radiation therapy during cancer specifically in head or neck often causes irritation in the lining of the mouth, throat, and esophagus. This makes eating and swallowing a difficult task. Maintaining proper oral hygiene is imperative in cases of mouth sores. Alcohol has no boons and only banes. It contributes to dehydration. It weakens body’s immune system and adds no nutritional values to the already compromised body. Dry mouth is a very common side effect of chemotherapy. To put a check on dehydration, adequate supply of fluids is imperative, barring caffeinated beverages as they can exacerbate the symptoms of dehydration. 8-10 glasses of water is likely to suffice. Dividing the daily nutrition obtained from food into small 5-6 ‘mini’ meals throughout the day is always beneficial. It never lets the body run out of calories which, in turn gives the body adequate strength to cope with the harsh treatment methods. It also helps to deal with the side-effects like nausea. Eating every three hours thus is a nice plan to keep the body going. Missing teeth, receding gums leading to loosening of teeth, mouth sores, and jaw pain- all these ultimately destroy normal appetite Along with all these, its necessary to be very particular about healthy fats, good amount of protein in the diet. e.g- Olive oil/ Fish oil/ Avocados/Nuts and Seeds. In addition, eggs/ lean meat/ low fat dairy food/ soya foods etc. (The author is a lifestyle coach and diet counsellor. She tweets @Bipasha1sugati))
Breaking Down Stigma: What Is It? We’ve all heard the word, but sometimes its meaning gets lost. At the core, stigma is a negative perception towards a person or a group of people. Related to stigma is discrimination, a negative action taken against a person or a group. So, stigma (the perception) causes discrimination (the act). Here’s an example. There’s a young man who has been struggling with feelings of hopelessness and distress. After seeing a doctor, he was diagnosed with depression. When he talks to a friend about this, his friend becomes visibly uncomfortable, likely because there is a social stigma around male vulnerability. Especially when it ties to mental health. Later that day, his friend is going to a birthday party, but he doesn’t get invited because he “will act too sad.” That is discrimination. Stigma and discrimination don’t always have to be large feelings or actions, they can manifest in small ways. They can be seen when people avoid socializing with someone who has a mental illness. They can be telling a friend or family member they are overreacting to their symptoms. In a more grand form, they can be the barriers that society places on people with mental illness that make it more challenging to get housing, employment, and proper healthcare. The Stigma of Mental Illness: How It Happens Discrimination against people with mental illness happens for a variety of reasons. Often, it happens out of ignorance. People are simply uneducated about mental illness–largely because we still don’t talk about it enough. Without the proper dialogue around mental health and wellness, it’s easy to become confused, afraid, or judgemental to those who experience mental illness. Discrimination against those with mental illness typically starts by thinking of people with mental illness as the “other,” as different from oneself. With no direct experience or education, people can fear things that are different or difficult to comprehend. Because someone struggles to relate to the experiences of those with mental illness, they may assume they’re overreacting. Or, they may be suspicious or wary. The sad reality is that stigmas are embedded in our culture.. One common stigma is that people with mental illness are more likely to be violent. Another is that it’s all in their head. We frequently hear people talk about “getting over it,” but we don’t hear about how. We internalize these messages from friends, family, teachers, leaders, and the media without even realizing it. If you grow up in an environment where mental illness is stigmatized, it can be easy to adopt those beliefs without even being fully aware. Why Does It Matter? Stigma and discrimination matter because they tell people that they are less than. They build shame and barriers. They have the ability to drastically alter the course of someone’s life. Stigma causes people to feel as though mental illness is their fault, even though it’s not. Mental illness is sparked by a variety of factors, including biological, societal, psychological, and other genetic factors. It is not a choice. When people with mental illness internalize the message that their mental illness must be their fault it can lead to guilt, shame, and low self-esteem. One of the serious consequences of stigma is that it becomes a barrier that can prevent people from seeking treatment. Only 43% of American adults with mental illness get treatment. This means over half of the people who live with mental illness are living without help. Internalized shame can cause people to avoid treatment. They may believe they should be able to fix it themselves, or they may fear treatment because of what they’ve heard. Other factors can also lead to the avoidance of mental healthcare, too, including high healthcare costs and service availability. We Are The Solution We are the biggest advocates for fighting against the stigma of mental illness. We can try to change our community’s attitudes towards mental illness through: - Legislation. You can advocate or support organizations that advocate for better mental healthcare. You can call your legislators or testify for or against a bill relating to mental health. - Organization. You can join others in bringing awareness to mental health. At Guild, we have several events every year to tell the stories of our clients and staff members. link to events page. We value bringing awareness to mental illness. - Education. Educational courses in schools and workplaces can help lead to decreased negative attitudes towards people with mental illness. Knowing and acknowledging that mental illness is a medical condition is essential to breaking down barriers. - Communication. Talking about mental illness makes it less taboo and helps people realize they aren’t alone. Sharing your story can help combat stigma. It’s also important to listen to and show compassion for people you know with mental illness. To reduce stigma, we must act. People in power must change their attitudes about people with mental illness. This can help our communities make changes that effectively include and empower people with mental illness, and ultimately, improve their lives. If you are interested in getting involved in mental health advocacy, consider volunteering for Guild. If you want to help break barriers by sharing your story and showing others they are not alone, you can guest blog for us. Email email@example.com for more information and to get started! It’s Not Stigma, It’s Discrimination, National Alliance on Mental Illness. Mental Illness Stigma: Concepts, Consequences, and Initiatives to Reduce Stigma, Science Direct. Mental health: Overcoming the Stigma of Mental Illness, Mayo Clinic. Understanding Sigma as a Mental Health Barrier, Xtelligent Healthcare Media. Does More Mental Health Treatment and Less Stigma Produce Better Mental Health?, The Conversation U.S. “A Disease Like Any Other”? A Decade of Change in Public Reactions to Schizophrenia, Depression, and Alcohol Dependence, American Journal of Psychiatry.
For as long as we can remember, galactic disks and flying saucers have always been the subject of theories and conspiracies. Other than the numerous reported sightings over the years, there are also traces of them all over ancient ruins and artifacts. Among these disks is Peru’s metropolitan museum’s interesting and enigmatic artifact. Despite the efforts of both the scientific community and the public, we still have no idea where this artifact came from or why it was made. This disk is simply known as the “Galactic Disk”. As it stands, there is no conclusive answer to what this disk is for. But, if it turns out that this was meant to be a replica of the Milky Way Galaxy, it would alter our perception of previous civilization at the very core. What’s even more mind-boggling is that there seem to be distinctive marks on the disk that shows where we are in the galaxy. This is an astounding coincidence. And, if the theory is that this disk is a replica of our galaxy, then that mark on the facade of the “Galactic Disk” is where the Earth was exactly thousands of years ago. The “Galactic Disk” that is seen in the sky from time to time is a phenomenon that has caught the attention of many people, including scientists and those who are not into science. This phenomenon was first theorized by scientists back in the 1850s and has been discussed in a science fiction book. It is said to appear during solar eclipses or with comet exploration missions such as Rosetta’s comet mission on board the Philae lander. The “Galactic Disk,” which appears much like an aura, can be seen around us at all times and can be observed with different objects, such as stars or planets. In the early 1900s through 1950s, scientists thought they understand galaxies. They studied stars in detail and determined their brightness and color to figure out what type of galaxy they were in. In the 1960s however, astronomer Fritz Zwicky noticed something strange about galaxies – their mass was concentrated in their cores. Their mass distribution just didn’t make sense to them. Nobody knew what could cause this phenomenon until the Kepler mission discovered thousands of planets around other stars. One such galactic disk is called the Galactic Disk of Andromeda, which has been baffling scientists for a while now. The original findings were announced in 2016 and made international headlines. But scientists now say this object actually doesn’t exist at all. Other theories are less fascinating but still as mind-blowing nonetheless. One of these is that it is supposed to be a replica of a UFO (Unidentified Flying Object) from an alien civilization that made contact with humanity in the past. According to this belief, this would have been made by a very ancient culture in ancient India. And it is believed that the old myths about “the gods descending on Earth” actually point out the extraterrestrials on the UFO. For now, we have no definite answer to which theory is correct. Regardless, finding out the origin and purpose of the Galactic Disk is sure to shake our understanding of humanity in the past. © 2022, THE STRANGE TALES. All rights reserved! On republishing this post you must provide link to original post!
Assessment 5 Instructions: Homework: Genetics Lab For this assignment, you will be participating in a lab activity on genetics by analyzing the pedigree chart and karyotype for two patients. REPRODUCTION AND GENETICS The reproductive systems in males and females are different but have the common goal of continuation of human species. We will look closely at the reproductive systems in males and females and inheritance of genes. Further, we will explore genetic diseases in families and the concept of gene therapy for providing hope for genetically inherited disorders. Genetics can play a role in the traits that we inherit, but the environment around us can also impact our traits. We are born with a genetic code that is a culmination of genes from our parents and generations before us. Genetic diseases in families often are “hidden” if they are a recessive trait, such as cystic fibrosis or sickle-cell anemia. However, with the advances in science, gene therapy provides new hope for genetically inherited disorders like sickle-cell anemia.Have you ever wanted to know more about where exactly you came from? It has never been easier to find out thanks to the explosion of at-home DNA testing kits. Millions of people have tried them, resulting in a great surge in popularity. Many new companies offer genetic testing, also known as DNA testing, that allows an individual to receive a genetic diagnosis of their vulnerabilities to inherited diseases. In general, this helps determine an individual’s ancestry or biological relationships between people. Read the articles to learn more information. In this lab, you will analyze the pedigree chart and karyotype for two patients Kayla and Emily. A karyotype is a picture of stained chromosomes arranged to show chromosome pairs. Abnormalities in chromosome number or size can be easily identified in a karyotype. Pedigree charts give a symbolic representation of phenotypic (observable) traits through a family. Using a pedigree, researchers can trace the pathway of a disease through families: If gene therapy was available to fix a gene before birth, do you think this might cross the lines of unethical research? Remember the following as you go through the lab: Complete the assessment at the end of the lab. To do this, fill out the items requested within the lab, download that document or documents to your computer, and save it. You must attach the documents to the assignment and then submit the assignment. Make sure that you read the Homework: Genetics System Lab Scoring Guide prior to submitting your document to ensure you have met all of the expectations for this assignment. It is recommended to review the scoring guide prior to downloading your document, or documents, to your computer, since all work must be completed within the lab. Competency 1: Describe the organization of the human body. Explain the inheritance of an autosomal recessive trait by reading a pedigree. Explain the gender of the second patient in a lab scenario. Explain the results of the karyotype and how the chromosomal abnormalities affect the body systems. Explain the positive and negative ramifications of genetic testing. Requirements: 1 day Genetics LabQuestion:What individuals would be affected by cystic fibrosis in the pedigree? Why?Answer:In the Pedigree Arelene, Tom, Wilma and Carla are affected. (Darkened circle and square) Cystic Fibrosis is anautosomal recessive disorder and for a person to be affected and have the phenotype traits, he or she musthave both genes from parents.Question:Would Michael be normal or be carrier of cystic fibrosis? Why?Answer:Michael must be a carrier as he has a daughter who is affected. for his daughter to be affected, Michael has tobe a carrier, and his wife has to be a carrier too.Question:Would Sam and Ann be normal or be a carrier of cystic fibrosis? Why?Answer:Ann is a carrier as one parent is affected and the other is a carrier, so Ann is definitely a carrier. Sam is acarrier as one parent is affected and the other is a carrier, so Sam is definitely a carrier. Arelene, the mother isaffected, and she has two kids affected, Wilma and Tom so George, the husband is a carrier and that why alloffspring are either carrier or affected.Question:Based on the pedigree, what is genotype of Ann and the probability that Ann could pass down the cysticfibrosis trait?Answer:Ann is carrier, and she is married to Michael who is a carrier too. the chances to pass the cystic fibrosis trait tooffspring is 25%. the chances for having a carrier offspring are 50%, and chances for having free offspringis25%Genotype will be either a carrier (Cc) upper case C is the cystic fibrosis Gene, and Lower-case c is thefree gene.Question:What is the gender of the fetus?Answer:The gender of the fetus is Male. the Karyotype has XY chromosomes (23 pair) XX is female XY is male.Question:Are there any chromosomal abnormalities?Answer:Yes, there is a chromosomal abnormality. there is an extra chromosome; there is 3 copies of chromosome 21,It is called trisomy which means three.Question:What would this chromosomal combination result in?Answer:Trisomy 21 leads to a genetic disease called Down Syndrome. The affected patient will have genetic.Question: What information might a genetic counselor provide to Ann?Answer:Genetic counselors help identify families at possible risk of a genetic condition by gathering and analyzingfamily history and inheritance patterns and calculating chances of recurrence. They provide information aboutgenetic testing and related procedures.Question:What information might a genetic counselor provide to Emily?Answer:Genetic counseling gives you information about how genetic conditions might affect you or your family. Thegenetic counselor or other healthcare professional will collect your personal and family health history. They canuse this information to determine how likely it is that you or your family member has a genetic condition. Resources: Reproduction and Genetics Top of Form Bottom of Form View the??infographic by selecting the system to learn how the reproductive system functions. Barclay, T. (2020, July 29).?. Innerbody Research. https://www.innerbody.com/image/repfov.html#full-description Barclay, T. (2020, July 29).?. Innerbody Research. ml#full-description KidsHealth. (n.d.).?. https://kidshealth.org/en/parents/genetic-counseling.html Ireland, K. A. (2018).?Visualizing human biology?(5th ed.). Hoboken, NJ: John Wiley and Sons. Chapter 19, “The Reproductive Systems: Maintaining the Species.” This chapter focuses on the male and female reproductive systems and the importance of estrogen and testosterone. It also describes the negative feedback loops that control the production of sperm in males and the menstrual cycle in females. Genetic Testing Resources Seward, B. (2018).?.?Therapeutic Innovation & Regulatory Science,?52(4), 482?488. Rothstein, M. A. (2018).?.?Journal of Law, Medicine & Ethics,?46(3), 794?801. Spector-Bagdady, K. (2015).?.?American Journal of Law & Medicine,?41(4), 568?616. U.S. Food and Drug Administration. (2019).??https://www.fda.gov/medical-devices/vitro-diagnostics/direct-consumer-tests Holt, L., & Gosk, S. (2018).?.?CQ Roll Call. Medline Plus. (2020, August 4).?. https://medlineplus.gov/ency/article/003935.htm In addition, consider the work of the National Institutes of Health’s (NIH) National Genome Research Institute to prevent genetic discrimination: “Many Americans fear that participating in research or undergoing genetic testing will lead to being discriminated against based on their genetics. Such fears may dissuade patients from taking genomics-based clinical tests or volunteering to participate in the research necessary for the development of new tests, therapies, and cures. To address this, in 2008 the Genetic Information Nondiscrimination Act (GINA) was passed into law, prohibiting discrimination by employers and health insurers” (National Human Genome Research Institute, 2017). Find more about the NIH’s work as you read the Genetic Information Nondiscrimination Act of 2008 that prohibits insurance companies and employers from genetic discrimination: National Institute of Health: National Human Genome Research Institute. (2020).??https://www.genome.gov/about-genomics/policy-issues/Genetic-Discrimination Ireland, K. A. (2018).?Visualizing human biology.?(5th ed.).?John Wiley and Sons. Chapter 21, “Inheritance, Genetics, and Molecular Biology.” In this chapter, you will learn more about gene expression and inheritance. What are main differences between males and females? Why do I look like my mom and grandma, but not my dad? We are a professional custom writing website. If you have searched a question and bumped into our website just know you are in the right place to get help in your coursework. Yes. We have posted over our previous orders to display our experience. Since we have done this question before, we can also do it for you. To make sure we do it perfectly, please fill our Order Form. Filling the order form correctly will assist our team in referencing, specifications and future communication. 1. Click on the “Place order tab at the top menu or “Order Now” icon at the bottom and a new page will appear with an order form to be filled. 2. Fill in your paper’s requirements in the "PAPER INFORMATION" section and click “PRICE CALCULATION” at the bottom to calculate your order price. 3. Fill in your paper’s academic level, deadline and the required number of pages from the drop-down menus. 4. Click “FINAL STEP” to enter your registration details and get an account with us for record keeping and then, click on “PROCEED TO CHECKOUT” at the bottom of the page. 5. From there, the payment sections will show, follow the guided payment process and your order will be available for our writing team to work on it. Need help with this assignment? Order it here claim 25% discount Discount Code: SAVE25
Stress testing or stress test usually involves walking on a treadmill or riding a stationary bike, and your heart rate, blood pressure, and breathing are monitored during this process. Otherwise you will get drugs that mimic the effects of exercise. Stress tests (also known as stress tests) therefore, show how your heart works during physical exercise. Because exercise makes your heart harder and strong, and stress or exercise tests can reveal problems with your heart's blood circulation. If you have signs or symptoms of coronary artery disease or arrhythmia (arrhythmia), your doctor may recommend a stress test. The test can also guide treatment decisions, measure treatment effectiveness, or determine severity. Why You should go for Stress Testing Diagnosis of coronary artery disease. Coronary arteries are the main blood vessels that supply blood, oxygen and nutrients to your heart. When these arteries are damaged or sick, coronary artery disease develops - usually due to deposits of cholesterol and other substances (slabs). Diagnosis of arrhythmia (arrhythmia). If the electrical pulse regulating your heart rhythm is not working properly, it can cause arrhythmias, which can cause the heart to beat too fast, too slow or irregularly. The Stages Of Stress Testing The stress test takes about an hour, including preparation time and time required to complete the actual test. The actual test takes only about 15 minutes. You can perform stress tests that let you walk on a treadmill or pedal on a stationary bike. If you can't exercise, you will get an intravenous drug that simulates exercise by increasing blood flow to the heart. Before The Stress Test First, your doctor will ask about your medical history and the frequency and intensity of your exercise. This will determine the amount of exercise that is right for you during the test. Your doctor will also listen to your heart and lungs for abnormalities that could affect the test results. During The Stress Test A nurse or technician will put patches (electrodes) on your chest, thighs and arms. Some areas may need shaving to help them get stuck. The wires of the electrodes are connected to an ECG machine that records electrical signals that trigger your heartbeat. During the test, a belt in your arm will be used to check your blood pressure. You may be asked to take a breath to show your ability to breathe during a test, and/or a workout. If you do not exercise, your doctor will inject your medication into your veins, which will increase blood flow to your heart In the process. You may feel red or have difficulty breathing during the training such as headache. You can slowly start training for a run or bike. As the test progresses, experience becomes more difficult. You can use sandals on the runway to protect your balance. Do not hang too tight, as this can distort the results.. And You will continue to workout until your heart rate reaches a specific goal, or until symptoms appear that prevent you from continuing. After The Stress Test After you stop exercising, you may be asked to sit still for a few seconds, and then lie down with the monitor down. When your heart rate and breathing are back to normal, your doctor can monitor for any abnormalities. After your exercise test is complete, you can resume normal activities unless your doctor tells you otherwise. The Result After the Stress Test If the data collected during a workout test indicates that your heart is functioning normally, additional testing may not be required. However, if the results are normal and your symptoms continue to worsen, your doctor may recommend a nuclear stress test or other stress tests that include bloodstream drugs or echocardiography before or after workout. These tests are more accurate and give more information about your heart activity, but they are also more expensive. If the results of the stress test indicate that you may have coronary artery disease or arrhythmia, your doctor will use this information to develop a treatment plan. You may need other tests such as coronary angiography Though. If you have a stress test to determine how you will treat your heart disease, your doctor will use the results to plan or change your treatment options. The Risk Associated With Stress Testing Doing Stress Testing and safe and not many complications are recorded to it till date. However, as you would generally have with any medical exercises, below are those rare complications associated with Stress Testing: Hypotension. During or after exercise, your blood pressure may drop, which can make you feel stagnant and tired. The problem should be solved after the training is stopped. Abnormal heart rhythm (arrhythmia). Arrhythmias that arise from stress tests generally disappear after stopping training. Heart attack (myocardial infarction). Rarely, physical tests can cause a heart attack. So, when you notice any of the symptoms as listed above in your body, that might be the time to see a doctor or go for a Stress test if you so desired.
Having teeth out of alignment can be both unsightly and a danger to our oral health. Adjusting them is a precise practice, requiring numerous considerations before adjusting the position and angle of our teeth. The process involved requires ensuring that only those teeth needing realigning are altered. To achieve this goal, a special process was developed called orthodontic anchorage. Anchorages have been an essential part of orthodontic care for over a century, and numerous developments have occurred in that time. Using Anchorage In Orthodontic Treatments The initial anchorage was developed and introduced by a dentist named Henry Albert Baker. So significant was this contribution to orthodontic treatments that it continues to bear his name. Baker’s Anchorage was the first to properly perform an orthodontic adjustment in a growing number of tools. Anchorages now have a classification system that indicates various aspects of each one. These classifications include: - Site-Based Classification - Intraoral – Those anchorages only involve space inside the mouth - Extraoral – Facemasks and headgear are the foundation of extraoral anchorages. Occipital and cervical anchorages are the most common, with combination headgear including aspects of each. - Muscular – The use of muscle tissue to secure a tooth - Number of Treated Teeth - Simple/Primary – Anchorages affecting a single tooth - Compound – Anchorages affecting multiple teeth - Reinforced – Anchorages involving multiple points to secure the desired teeth in place. This often includes extraoral appliances such as headgear and facemasks. - Reciprocal – Anchorages that draw two teeth towards each other an equal amount. - Stationary – Anchorages are used to alter the angle, not the position, of a single tooth. - Space-Based Classification - Group A – Anchorages moving teeth towards the rear of the mouth - Group B – Anchorages moving front and rear teeth together. - Group C – Anchorages moving teeth towards the front of the mouth. - Absolute Anchorage – Anchorages that adjust only the rear teeth without involving the front teeth. Using this system ensures that dentists can accurately describe any anchorage being used. This makes noting information about the treatment easier and far more accurate. They include what appliances are being used and the nature of the adjustment. There are two outlying classifications describing the use of bone for adjustment and implants. Talk To Your Dentist About Orthodontic Anchorage This guide was developed to help patients better understand the orthodontic process and the tools involved. This was done, in part, to help them understand the dangers involved in using 3rd party mail-order orthodontists to receive orthodontic care. Without careful and direct oversight, there are numerous dangers the patient may face. Remote orthodontists cannot detect numerous health conditions from a simple dental impression that can complicate the orthodontic process. Further, the target teeth can move in unexpected ways during the treatment. Without regular visits to a dentist and accessibility of imaging, the treatment may not be effective. In the best case, your teeth will require another treatment. In the worst, additional work may be needed creating additional expense. Speak to your dentist to start your orthodontic process, and involve them if you opt to go with a mail-order process.
The gamma distribution is a two-parameter family of curves. The gamma distribution models sums of exponentially distributed random variables and generalizes both the chi-square and exponential distributions. Statistics and Machine Learning Toolbox™ offers several ways to work with the gamma distribution. Create a probability distribution object GammaDistributionby fitting a probability distribution to sample data ( fitdist) or by specifying parameter values ( makedist). Then, use object functions to evaluate the distribution, generate random numbers, and so on. Work with the gamma distribution interactively by using the Distribution Fitter app. You can export an object from the app and use the object functions. Use distribution-specific functions ( randg) with specified distribution parameters. The distribution-specific functions can accept parameters of multiple gamma distributions. The gamma distribution uses the following parameters. The standard gamma distribution has unit scale. The sum of two gamma random variables with shape parameters a1 and a2 both with scale parameter b is a gamma random variable with shape parameter a = a1 + a2 and scale parameter b. The likelihood function is the probability density function (pdf) viewed as a function of the parameters. The maximum likelihood estimates (MLEs) are the parameter estimates that maximize the likelihood function for fixed values of The maximum likelihood estimators of a and b for the gamma distribution are the solutions to the simultaneous equations where is the sample mean for the sample x1, xn, and Ψ is the digamma function To fit the gamma distribution to data and find parameter estimates, use mle, which return fitdist returns the fitted probability GammaDistribution. The object b store the parameter For an example, see Fit Gamma Distribution to Data. Probability Density Function The pdf of the gamma distribution is where Γ( · ) is the Gamma function. For an example, see Compute Gamma Distribution pdf. Cumulative Distribution Function The cumulative distribution function (cdf) of the gamma distribution is The result p is the probability that a single observation from the gamma distribution with parameters a and b falls in the interval [0 x]. For an example, see Compute Gamma Distribution cdf. The gamma cdf is related to the incomplete gamma function Inverse Cumulative Distribution Function The inverse cumulative distribution function (icdf) of the gamma distribution in terms of the gamma cdf is The result x is the value such that an observation from the gamma distribution with parameters a and b falls in the range [0 x] with probability p. The preceding integral equation has no known analytical solution. gaminv uses an iterative approach (Newton's method) to converge on the solution. The mean of the gamma distribution is ab. The variance of the gamma distribution is ab2. Fit Gamma Distribution to Data Generate a sample of 100 gamma random numbers with shape 3 and scale x = gamrnd(3,5,100,1); Fit a gamma distribution to data using pd = fitdist(x,'gamma') pd = GammaDistribution Gamma distribution a = 2.7783 [2.1374, 3.61137] b = 5.73438 [4.30198, 7.64372] fitdist returns a GammaDistribution object. The intervals next to the parameter estimates are the 95% confidence intervals for the distribution parameters. Estimate the parameters b using the distribution functions. [muhat,muci] = gamfit(x) % Distribution specific function muhat = 1×2 2.7783 5.7344 muci = 2×2 2.1374 4.3020 3.6114 7.6437 [muhat2,muci2] = mle(x,'distribution','gamma') % Generic function muhat2 = 1×2 2.7783 5.7344 muci2 = 2×2 2.1374 4.3020 3.6114 7.6437 Compute Gamma Distribution pdf Compute the pdfs of the gamma distribution with several shape and scale parameters. x = 0:0.1:50; y1 = gampdf(x,1,10); y2 = gampdf(x,3,5); y3 = gampdf(x,6,4); Plot the pdfs. figure; plot(x,y1) hold on plot(x,y2) plot(x,y3) hold off xlabel('Observation') ylabel('Probability Density') legend('a = 1, b = 10','a = 3, b = 5','a = 6, b = 4') Compute Gamma Distribution cdf Compute the cdfs of the gamma distribution with several shape and scale parameters. x = 0:0.1:50; y1 = gamcdf(x,1,10); y2 = gamcdf(x,3,5); y3 = gamcdf(x,6,4); Plot the cdfs. figure; plot(x,y1) hold on plot(x,y2) plot(x,y3) hold off xlabel('Observation') ylabel('Cumulative Probability') legend('a = 1, b = 10','a = 3, b = 5','a = 6, b = 4',"Location","northwest") Compare Gamma and Normal Distribution pdfs The gamma distribution has the shape parameter and the scale parameter . For a large , the gamma distribution closely approximates the normal distribution with mean and variance . Compute the pdf of a gamma distribution with parameters a = 100 and b = 5. a = 100; b = 5; x = 250:750; y_gam = gampdf(x,a,b); For comparison, compute the mean, standard deviation, and pdf of the normal distribution that gamma approximates. mu = ab mu = 500 sigma = sqrt(ab^2) sigma = 50 y_norm = normpdf(x,mu,sigma); Plot the pdfs of the gamma distribution and the normal distribution on the same figure. plot(x,y_gam,'-',x,y_norm,'-.') title('Gamma and Normal pdfs') xlabel('Observation') ylabel('Probability Density') legend('Gamma Distribution','Normal Distribution') The pdf of the normal distribution approximates the pdf of the gamma distribution. Beta Distribution — The beta distribution is a two-parameter continuous distribution that has parameters a (first shape parameter) and b (second shape parameter). If X1 and X2 have standard gamma distributions with shape parameters a1 and a2 respectively, then has a beta distribution with shape parameters a1 and a2. Chi-Square Distribution — The chi-square distribution is a one-parameter continuous distribution that has parameter ν (degrees of freedom). The chi-square distribution is equal to the gamma distribution with 2a = ν and b = 2. Exponential Distribution — The exponential distribution is a one-parameter continuous distribution that has parameter μ (mean). The exponential distribution is equal to the gamma distribution with a = 1 and b = μ. The sum of k exponentially distributed random variables with mean μ is the gamma distribution with parameters a = k and μ = b. Nakagami Distribution — The Nakagami distribution is a two-parameter continuous distribution with shape parameter µ and scale parameter ω. If x has a Nakagami distribution, then x2 has a gamma distribution with a = μ and ab = ω. Normal Distribution — The normal distribution is a two-parameter continuous distribution that has parameters μ (mean) and σ (standard deviation). When a is large, the gamma distribution closely approximates a normal distribution with μ = ab and σ2 = ab2. For an example, see Compare Gamma and Normal Distribution pdfs. Abramowitz, Milton, and Irene A. Stegun, eds. Handbook of Mathematical Functions: With Formulas, Graphs, and Mathematical Tables. 9. Dover print.; [Nachdr. der Ausg. von 1972]. Dover Books on Mathematics. New York, NY: Dover Publ, 2013. Evans, Merran, Nicholas Hastings, and Brian Peacock. Statistical Distributions. 2nd ed. New York: J. Wiley, 1993. Hahn, Gerald J., and Samuel S. Shapiro. Statistical Models in Engineering. Wiley Classics Library. New York: Wiley, 1994. Lawless, Jerald F. Statistical Models and Methods for Lifetime Data. 2nd ed. Wiley Series in Probability and Statistics. Hoboken, N.J: Wiley-Interscience, 2003. Meeker, William Q., and Luis A. Escobar. Statistical Methods for Reliability Data. Wiley Series in Probability and Statistics. Applied Probability and Statistics Section. New York: Wiley, 1998. Marsaglia, George, and Wai Wan Tsang. “A Simple Method for Generating Gamma Variables.” ACM Transactions on Mathematical Software 26, no. 3 (September 1, 2000): 363–72. https://doi.org/10.1007/978-1-4613-8643-8.
Visual Evoked Potentials (VEPs) are electrical signals created by the brain in reaction to visual jolts, and they can be utilized to survey visual work. Visual Evoked Potentials (VEPs) are electrical signals created by the brain in reaction to visual jolts, and they can be utilized to survey visual work. Whereas VEPs have a few focal points, such as their non-invasive nature and the capacity to distinguish early changes in visual work, there are too a few impediments that got to be considered: VEPs can be influenced by different components such as consideration, weakness, and personal differences in neural preparation, which can lead to changeability within the recorded flag. VEPs are not continuously delicate enough to identify unpretentious changes in visual work, particularly within the early stages of visual brokenness. The translation of VEP can be complex and requires ability. Changes in Visual Evoked Potentials VEPs can be due to an assortment of components, counting changes within the optic nerve, retina, and visual cortex. Cost and equipment VEP testing requires specialized gear and prepared staff, which can make it costly and time-consuming. Constrained demonstrative esteem VEPs are basically utilized to evaluate visual work, but they have restricted symptomatic esteem in terms of distinguishing the basic cause of visual brokenness. Assisted symptomatic tests may be required to decide the cause of visual anomalies identified by VEPs. VEPs require the patient's participation to preserve obsession and consideration amid testing, which can be challenging in certain quiet populaces, such as youthful children or people with cognitive disabilities. Whereas VEPs test have a few preferences within the evaluation of visual function, they also have a few confinements that ought to be considered when deciphering comes about and deciding on their clinical utility.
Scientists say man's efforts and favourable conditions have helped restore ozone levels. Thirty years after a global effort to protect the ozone layer began, scientists have revealed that man’s efforts, combined with favourable climatic conditions, have shrunk it to its smallest area since 1988. In the 1970s, researchers established that chemicals used in fridges and aerosol cans, known as chlorofluorocarbons were eating away at the ozone layer above the Antarctic. Concerns that this was allowing carcinogenic radiation from space to penetrate more easily to the earth’s surface prompted a world-wide effort to reduce the chemical’s use, codified in the Montreal Protocol of 1987. Chlorofluorocarbons can remain in the atmosphere for many years but the reduction in their use does seem to be having an impact. In 2000, the hole in the ozone layer spread over an area of around 30 million square kilometres. Now, thanks in part to warmer conditions in the upper atmosphere it has dropped below 20 million square kilometres, according to Nasa . That’s about 2.5 times the size of the USA. Nasa describes ozone, formed from Oxygen atoms, as like a sunscreen protecting the earth, although it can have a harmful impact if present in the air that we breathe. Image: NASA/NASA Ozone Watch/Katy Mersmann
REPLICATION OF FORT ST. JEAN BAPTISTE Fort St. Jean Baptiste de Natchitoches was a strategic outpost, established in 1716, that prevented the Spaniards, in Mexico, from advancing further into French Louisiana. The Fort continued to serve this vital function until the entire French colony west of the Mississippi, with New Orleans and the Isle of Orleans on the east bank, was ceded to Spain in 1762, following France’s defeat by England in the French and Indian War. It was finally abandoned soon after the 1803 Louisiana Purchase when the United States built Fort Claiborne nearby. The reconstruction of the Fort is based on a carefully drawn plan made in 1733 by the French architect/engineer Ignace Francois Broutin after he visited the Fort in August 1732 and at that time had several new buildings built; including a long barracks building, a small warehouse and a house for the warehouse keeper. Careful research was conducted in the archives of France and Spain on colonial fortification construction methods and working from Broutin’s plan and description of the Fort, an authentic reconstruction was accomplished. Fort St. Jean Baptiste was replicated utilizing many of those same construction methods, adapting to some modern measures, such as treated lumber, concealed fasteners, and concrete footings, to assure a longer life. It serves as an important era in Louisiana’s colonial history, demonstrating the fortification construction and life style of a Louisiana frontier settlement.
Nitric acid and nitrous acid are mono basic oxoacids of nitrogen. But they are very different in chemical and physical properties. Nitric acid is widely used in chemical industry for producing other chemicals. Also nitric acid is used as an strong acid and oxidizing acid in laboratories. In this tutorial, we are leaning about characteristics, preparation and some reactions of HNO3 and HNO2 acids. When you are dealing with acids such as nitric acid, you should be very careful to avoid any injuries. HNO2 decomposes to HNO3, NO, H2O when temperature is increased in the solution. HNO2 does not dissociate completely in the water. Therefore its aqueous solution H+ concentration is very less when it compare with HNO2 concentration. Nitrous acid can be oxidized because nitrogen atom is at +3 oxidation state. Therefore HNO2 can reduce acidic potassium permanganate ( H+ / KMnO4 ). Due to unstability of nitrous acid, it is not stored in the laboratory. At requirement, we prepare the nitrous acid as below. Solid sodium nitrate (NaNO3) is heated to decompose solid sodium nitrite (NaNO2) and oxygen (O2) gas. This reaction is a redox reaction (oxidation - reduction reaction) Solid sodium nitrite is dissolved in water to prepare aqueous sodium nitrite. No reaction is occurred in this step. Add cold dilute HCl to aqueous sodium nitrite solution. It gives dilute nitrous acid and NaCl solution. Add concentrated H2SO4 acid to the solid NaNO3(s) and distill the mixture. Ostwald process is used in industry to production of nitric acid. Ammonia and oxygen are used as raw materials in the presence of Pt / Rh catalyst. Higher temperatures and pressure are applied in the production to get a successful yield. When the temperature of the acid solution increases, nitric acid starts to decomposes to nitrogen dioxide, oxygen and water. Nitrogen dioxide (NO2) is a brown gas. Nitric acid is a strong acid which dissociate completely in the water to H+ ions and NO3-. But, nitrous acid is a weak acid and partially dissociate. This happens because conjugate base (NO3-) of nitric acid is more stable. pKa of nitrous acid is 3.3 at 180C. Also, nitrous acid decomposes readily than nitric acid. Also, oxidation numbers of nitrogen atoms are different. In HNO2, nitrogen atom is at +3 oxidation state . In HNO3, nitrogen atom is at +5. Nitric acid is a strong acid. But nitrous acid is a weak acid. Therefore acidic strength of nitric acid is much higher than nitrous acid. When oxidation number increases, acidic characteristics increases. Oxidation number of nitrogen in nitric acid is +5 while it is +3 in nitrous acid. That is one reason why nitric acid is much acidic than nitrous acid. Oxidation state of HNO3 is +5. So nitrogen atom cannot be oxidized furthermore. Due to +5 oxidation state, nitric acid shows strong acidic properties. HNO2 is an oxo acid of nitrogen and it is a weak acid. HNO2 is also named as nitrous acid or nitric(III) acid. Nitrous acid is used very much in organic chemistry such as amine and HNO2 reaction. Aqueous nitrous acid is decomposed to nitric acid when temperature is increased. So after preparation of nitrous acid, nitric acid and nitrous acid solution mixture can be given. A strong acidic solution is given. HNO2 does not contain carbon as a element. So HNO2 is an inorganic compound. Nitrous acid is a weak monobasic acid. HNO2 decomposes to HNO3, NO and water easily at room temperature. This decomposition increases with temperature. Therefore, we cannot store nitrous acid for long time in the laboratory. When we require HNO2, at that moment HNO2 is prepared.
Powered by BMI CalculatorWhat is BMI? Body Mass Index (BMI) is a number calculated from a person's weight and height. BMI is a fairly reliable indicator of body fatness for most people. BMI does not measure body fat directly, but research has shown that BMI correlates to direct measures of body fat, such as underwater weighing and dual energy x-ray absorptiometry (DXA). BMI can be considered an alternative for direct measures of body fat. Additionally, BMI is an inexpensive and easy-to-perform method of screening for weight categories that may lead to health problems.How is BMI used? BMI is used as a screening tool to identify possible weight problems for adults. However, BMI is not a diagnostic tool. For example, although a person may have a high BMI, to determine if excess weight is a health risk, a healthcare provider would need to perform further assessments. These assessments might include skinfold thickness measurements, evaluations of diet, physical activity, family history, and other appropriate health screenings.How to use the BMI chart? On the BMI Calculator to the left, first tick your gender and body condition. Then, using the sliding scale indicator, enter your current height and weight. Your BMI is automatically calculated. Using this BMI, look it up on the chart below and determine which category you currently fall in. Blue - Underweight Green - Healthy Yellow - Overweight Orange - Obese Red – Extremely Obese The medical fraternity has identified and acknowledged some of the limitations of BMI. BMI calculation is solely dependant on the net weight and height of the individual and does not consider the distribution of muscle and bone mass. BMI also does not differentiate between body fat and muscle mass. This may often result in misleading information with regard to the amount of fat in an individual. There is a potential risk of overestimating ‘fatness’ in individuals with high muscle mass, such as body-builders, and underestimating the fat deposit in those with less lean body mass, such as the elderly.
‘A people without the knowledge of their past history, origin and culture is like a tree without roots.’ History has a value and relevance to all students whatever their academic ability, gender or age. It develops skills and knowledge that can be used by adults both in their role as a citizen and as a member of society. At Burford, we view History not only as simple facts and dates but encourage students to become detectives who explore the past in an exciting way. The process of historical inquiry encourages our students to critically analysis, develop a questioning and inquisitive nature and the ability to evaluate and interpret sources and opinions. History lessons at the Burford School provide a forum for debate and discussion on central issues which have changed and continue to impact upon the world around us. Staff and facilities The History Department is led by Mrs E Thomas. She is supported by four further teachers. It is a well resourced department in terms of textbooks and historical expertise. For Year Groups 7-11 Course Guides are provided to outline course content, assessment, terminology, further useful reading, suggested historical sites to visit etc. Years 10 & 11 Parent & Student Information Booklets Alongside the history lessons provided through the curriculum, the Department runs two trips. In late May there is a trip for Year 9 students to the World War 1 Battlefields. Every other year a trip to Berlin and Krakow is open to those in Years 12/13. Both these trips enhance and support areas of the curriculum covered in Key Stages 4 and 5. Two Sixth Form students are also provided with the opportunity to participate in the ‘Lessons from Auschwitz Project’ coordinated by the Holocaust Educational Trust. During the academic year, we also run a number of House Competitions, including historical debates and public speaking as well as written historical fiction. Several of the competitions are linked to the Historical Association, Local Historical Places and Cambridge University. Key Stage 3 History is a compulsory subject at Key Stage 3 with three lessons over a fortnight taught in Year 7 and Year 9 and four lessons a week in Year 8. Lesson sequences are based around enquiry questions such as ‘Why did William win the Battle of Hastings? or ‘Why did the King and Parliament go to war in 1663?’ These enquiries culminate in outcome tasks which include essays, spoken presentations, memorial designs, group projects and the writing of historical narratives. Below is an outline of some of the enquiries students will encounter across Key Stage 3. At the start of Year 7 students are introduced to key substantive concepts such as kingship, society, revolution, liberty, and feudalism and second order concepts which help us organise the process of studying history including cause and consequence, change and continuity and significance. Students then investigate these different enquiries during the course of the year: - What is History? - What was England like before 1066? - Why did William win the Battle of Hastings? - How did William take control of England? - Why was the church so important in people’s lives? - Why risk death to defend the church? - When were Jews in most danger in medieval England? - Were Becket and Henry always enemies? - Could a medieval monarch do whatever they wanted? - Who mattered most in medieval society? - What makes a good historical story about the Black Death? - Why did the peasants revolt in 1381? Year 8 starts with an overview of the period 1485-1900. Some of the concepts from Year 7 are further explored, building on students’ ideas of continuity and change, cause and consequence. During this year students learn to handle source work and evidence more rigorously. Enquiry questions students will encounter in Year 8 include: - Who was Elizabeth I? - What was the most serious threat to Elizabeth I? - Why was the world expanding in the 16th and 17th centuries? - Why did the King and parliament go to war in 1642? - How similar were the experiences of soldiers and civilians in the Civil War? - Why were kings back in fashion by 1660? - How different were the attitudes of the colonised and colonisers? - What was it like to be involved in the slave trade? - How did the meaning of ‘government’ change for the people of Britain c1600-c1900? Year 9 starts with an overview of the period 1900-present day. Enquiry questions students will encounter in Year 9 include: - 20th Century: What do you know? - How safe was it to live in Britain during the Edwardian age? - Two Bullets & Twenty Million Deaths: Why did a murder lead to war in 1914? - What motivated men to continue fighting in the trenches? - To what extent was WWI a ‘World War’? - How fair was the Treaty of Versailles? - How did new ideas cause conflict? - How was the Second World War won? - What was the Holocaust? - Why did the sun set on the British Empire? - Sixties: How far was there a social and cultural revolution? - What’s the best way to bring about change? Key Stage 4 – Edexcel GCSE History Almost half of each year group choose to take History at GCSE. Students follow the Edexcel GCSE course and are required to be self- discipline throughout. They are taught how to structure essays and answers, form and support arguments, debate and come to reasoned judgments. There is an emphasis on source-work, particularly questioning evidence. Mock exams, exam type question practice and revision sessions are run to ensure students have every opportunity to reach their potential. Students study the following units during the two years: - Paper 1: Crime and punishment in Britain, c1000–present and Whitechapel, c1870–c1900: crime, policing and the inner city. Paper 1 gives students the opportunity to study the changing nature of crime and punishment from the medieval period to the present day. Students examine aspects such as the ‘hue and cry’, witchcraft, the Gunpowder plotters and the development of the Metropolitan Police Force. - Paper 2: British Depth Study – Option B4 Early Elizabethan England, 1558-88 The British Depth Study allows students to examine the challenges that Elizabeth, the Virgin Queen, faced due to her gender, her marriage and plots against her both at home and abroad. Students also have an opportunity to delve into the world of Elizabethan exploration and new technologies. - Paper 2: Period Study: Option 26/27 – Superpower relations and the Cold War, 1941–91 Through the Period Study, students will examine the origins, development and ending of the Cold War from the division of Berlin, to the Cuban Missile Crisis, Olympic Boycotts and the significance of the fall of the Berlin Wall. - Paper 3: Modern Depth Study: Option 31 – Weimar and Nazi Germany, 1918–39 In this enquiry students will examine the problems faced by the Weimar Republic and the context of Hitler’s rise to power. Students investigate the impact of the Nazi dictatorship including the introduction of the Hitler Youth and the persecution of the Jews. Key Stage 5 – Edexcel A-level History In Year 12 students study Britain, c1785–c1870: democracy, protest and reform and the unification of Germany, c1840–71. Studying two different countries allows students to develop a greater appreciation of the nature of power and authority in the given period, and to understand the similarities and contrasts between them. In Year 13, Civil rights and race relations in the USA, 1850–2009 are studied. This gives students a chance to explore developments that have shaped contemporary America and remain a fundamental issue in US society: the changing pattern of race relations between black and white Americans, both in terms of civil rights and also broader social and cultural changes over a period that began with millions of black Americans in slavery and ended with Barack Obama as President. Coursework forms a part of Year 13. The aim of this is to enable students to develop skills in the analysis and evaluation of interpretations of history in a chosen question, problem or issue as part of an independently researched assignment. The focus is on understanding the nature and purpose of the work of the historian. Students have to form a critical view based on relevant reading on the question, problem or issue. They are specifically required to analyse, explain and evaluate the interpretations of three historians. Students are given the opportunity to choose their own focus for their coursework.
In this lesson on guitar strumming patterns I explain the basic subdivisions of the beat. To keep things simple I have stuck to beats split in divisions of two. There are actually more options than this when creating music, and in this lesson we’ll explore another group of rhythmic patterns: Guitar triplets. This will be done in a three step process. The first step is to see how triplets are notated, and how they sound. The second step is to play exercises where guitar triplet patterns are used in combination with regular subdivisions of the beat. The third step will be learning how to use these triplet patterns in your guitar improvisations and solos. Step 1: Feeling the triplet Before you can play triplets on the guitar you need to understand what’s going on and get familiar with their sound. In the following example (a) is just one quarter note (crotchet) being played on the beat, (b) is the quarter note divided in two eight notes (quavers), while in (c) the quarter note is divided into an eight note triplet. After listening to the next example enough times to get the sound of the triplet, play the whole example on your guitar using the given picking suggestions. Following that, play it with a metronome and gradually increase the tempo. The quarter note beat is not the only beat that can be divided into a triplet, though the most common. In the next example, (a) is a bar of two eight notes, (b) is two eight notes each divided in half – thus four sixteenth notes, while in (c) we have two groups of sixteenth note triplets. Half notes can also be divided into triplets. In the next example, (a) is a half note (minim), (b) is a half note divided in two quarter notes (crotchets) and (c) is the half note divided in three quarter note triplets. Step 2: Playing guitar triplet patterns. Though there may be parts of your solos where you play a series of consecutive triplets, in many cases the triplet pattern is played in conjunction with other rhythmic patterns to make the whole melody more interesting and expressive. The next examples are exercises on playing rhythms that include triplet subdivisions. Being able to play them fluently is a necessary step before starting to use triplets on guitar. Example 1: Eight note triplets Example 2: Sixteenth note triplets Example 3: Quarter note triplets Step 3: Using triplets to create music Applying everything you learn will speed up your guitar learning progress and significantly increase your motivation to practice the guitar. Which is what we’ll be doing with guitar triplets. In the first part of this step, I’ll give you an example of a guitar solo that makes use of triplets. Learn this short extract well before creating your own, so that you get a clear idea of the rhythmic effect triplets can have on a melody. Note that the solo uses phrasing techniques like string bending and vibrato. Rhythmic phrasing, in this case the use of triplets, is only one aspect of phrasing that makes guitar music interesting. Another aspect is getting a different sound from the same note by applying such techniques. Have you practiced all the guitar exercises and examples given in this lesson? If yes, by now you can not only feel triplets, but also play them, and have a clear idea of how they can be used in a musical context. The final step is to create your own music that includes triplet patterns. To make things easier for you I’m giving you the opening of a short guitar solo using notes from the A minor pentatonic scale. Experiment with giving this two bar intro different endings in the four empty bars, and use guitar triplets in the music you create. Conclusion: How to think of rhythmic patterns When you learn a new musical concept, such as the rhythmic pattern explained in this lesson, that of the triplet, put it immediately into use. When I learn a new rhythmic pattern, a new scale, chord, arpeggio, or any information or skill I acquire to improve my guitar playing, I put it immediately into practical use. There are many advantages for this, which include: - What you learn will be completely ingrained in you and you won’t foget it in the future. - You’re not only training your guitar skills, but also your creativity. Contrary to popular belief, people are actually creative. The only reason “they don’t have creativity in them” is that they never train themselves to use it. - It helps you see connections. Connecting the dots when learning the guitar is very important. See the big picture. After learning a concept or gaining a skill, always use it in combination with the other concepts and skills you have already gained. - You will learn faster. - It’s more fun. Enjoying the process of learning the guitar is a crucial factor in developing an ideal guitar practicing mindset that leads to success. While mastering triplets on the guitar, it’s a good idea to also look at other rhythmic patterns you already know and experiment in mixing and matching to get familiar with their use and see all the options in front of you when improvising or soloing. You may consider giving a donation, by which you will be helping a songwriter achieve his dreams. Each contribution, no matter how small, will make a difference.
Parents, please take note. If you want your kids to do well in life, limit their screen time to less than two hours, encourage them to do physical activities and to have sufficient sleep, suggests new research. Following a two-hour screen time limit during childhood and adolescence is particularly important for cognitive development, showed the findings published in the journal The Lancet Child and Adolescent Health. “We found that more than two hours of recreational screen time in children was associated with poorer cognitive development,” said one of the researchers Jeremy Walsh, CHEO Research Institute, Canada. The study involved more than 4,500 US children aged 8-11 years. Children and parents completed questionnaires and measures at the outset of the trial to estimate the child’s physical activity, sleep and screen time. In addition, children also completed a cognition test, which assessed language abilities, episodic memory, executive function, attention, working memory and processing speed. The researchers examined how meeting recommendations for 9-11 hours of sleep, less than two hours of recreational screen time, and at least an hour of physical activity every day affected children’s cognition. The more individual recommendations the child met, the better was their cognition, the findings showed. In addition, meeting only the screen time recommendation or both the screen time and sleep recommendations had the strongest associations with cognitive development. “Behaviors and day-to-day activities contribute to brain and cognitive development in children, and physical activity, sedentary behavior, and sleep might independently and collectively affect cognition,” Walsh said. “Based on our findings, pediatricians, parents, educators, and policymakers should promote limiting recreational screen time and prioritizing healthy sleep routines throughout childhood and adolescence,” Walsh added.
Syncope is a common symptom in adolescents who come to the hospital emergency wards. The most common form of syncope is neurogenic type caused by impaired autoregulation of the circulatory system. This syncope is not generally life-threatening condition in a contrast to the less common but most dangerous cardiogenic type (e.g. cardiac arrhythmias due to Wolff–Parkinson– White syndrome, long QT time interval, atrioventricular blocks, haemodynamic obstructions in the outflow tract of the left or right ventricle, cardiomyopathy or coronary abnormalities). This paper refers to a new term, i.e. transient loss of consciousness. According to the new definition of syncope from 2009, temporary loss of consciousness has four components: a sudden occurrence, transient nature, short duration, and spontaneous regression. Currently, there are three main types of syncope associated with the cardiovascular system: neurogenic, orthostatic hypotension and a cardiac. The most common form in adolescents are neurogenic fainting which are often preceded by prodromal symptoms, i.e. decrease in blood pressure and heart rate. They can also occur in response to the stress or unusual situations. In the orthostatic syncope the loss of consciousness occurs in a very short time after the upright position and unlike neurogenic form, usually there are no prodromal symptoms, but tachycardia is present. The rarest, but also the most dangerous form of syncope is a cardiogenic type caused by arrhythmias or structural heart disease. This form may be the first sign of serious heart disease or even precede sudden cardiac death.
Through a series of 7 lessons, students will explore agricultural sustainability to answer the question, "How will we sustainably feed nearly 10 billion people by the year 2050?" APPLE GENETICS: A TASTY PHENOMENA Distinguish between sexual and asexual reproduction to explain how new varieties of apples are developed and then propagated to meet consumer demand. FOOD SCIENTIST FOR A DAY Students will discover some of the science involved in the production of food, explore careers in the area of food science, and develop an ice cream to represent their school. Using an interactive Kahoot Challenge, students will learn that agriculture and natural resources provide nearly all of the products we rely on in any given day. These learning activities have been adapted from the National Agricultural Literacy Curriculum Matrix and are ready for student eLearning engagement.
In the fields of philosophy and æsthetics, the derogatory term philistinism describes the 'manners, habits and character' of a person whose anti-intellectual social attitude undervalues and despises art and beauty, spirituality and intellect. A philistine person is of smugly narrow mind, and of conventional morality whose materialistic views and tastes indicate a lack of and an indifference to cultural and æsthetic values. Since the 19th century, the contemporary denotation of philistinism, as the behaviour of ‘ignorant, ill-behaved persons lacking in culture or artistic appreciation, and only concerned with materialistic values’ derives from Matthew Arnold’s adaptation to English of the German word Philister — as applied by university students in their antagonistic relations with the townspeople of Jena, Germany, where a row resulted in several deaths, in 1689. The German word derived from a sermon by Georg Heinrich Götze, the ecclesiastical superintendent who addressed the hostilities between students and townspeople. In the aftermath, the cleric Götze addressed the town-vs-gown matter with an admonishing sermon "The Philistines Be Upon Thee", drawn from the Book of Judges (Chapt. 16, 'Samson vs the Philistines'), of the Tanakh, and from the Christian Old Testament. In Word Research and Word History, the philologist Friedrich Kluge said that the word philistine originally had a positive meaning that identified a tall and strong man, such as Goliath; later the meaning changed to identify the "guards of the city". In German usage, university students applied the term Philister (Philistine) to describe a person who was not trained at university; in the German social context, the term identified the man (Philister) and the woman (Philisterin) who was not of the university social set. In English usage, as a descriptor of anti-intellectualism, the term philistine—a person deficient in the culture of the liberal arts—was common British usage by the decade of 1820, which described the bourgeois, merchant middle class of the Victorian Era (1837–1901), whose wealth rendered them indifferent to culture. In Culture and Anarchy: An Essay in Political and Social Criticism (1869), Matthew Arnold said: thumb\|right\|200px\|Vladimir Nabokov described the natures of philistinism and of the philistine. The denotations and connotations of the terms philistinism and philistine have evolved to consistently describe the uncouth person who is hostile to art, culture, and the life of the mind, who, in their stead, prefers the life of economic materialism and conspicuous consumption as paramount human activities. - 17th centuryWhilst involved in a lawsuit, the writer and poet Jonathan Swift (1667–1745), in the slang of his time, described a gruff bailiff as a philistine, someone who is considered a merciless enemy. - 18th centuryThe polymath Johann Wolfgang von Goethe (1749–1832) described the philistine personality, by asking: Goethe further described such men and women, by noting that: In the comedy of manners play, The Rivals (1775), Richard Brinsley Sheridan (1751–1816) identifies a violent aristocrat as 'that bloodthirsty Philistine, Sir Lucius O'Trigger'. - 19th century In The Sickness Unto Death (1849), the philosopher Søren Kierkegaard criticises the spiritlessness of the philistine-bourgeois mentality of triviality and the self-deception of despair. The philosopher Friedrich Nietzsche (1844–1900) identified the philistine as a person who, for a lack of true unity, could only define style in the negative. - 20th century - In the novel Der Ewige Spießer (The Eternal Philistine, 1930), the Austro–Hungarian writer Ödön von Horváth (1901–38) derided the cultural coarseness of the philistine man and his limited view of the world. The eponymous philistine is a failed businessman, a salesman of used cars, who aspires to the high-life of wealth; to realise that aspiration, he seeks to meet a rich woman who will support him, and so embarks upon a rail journey from Munich to Barcelona to seek her at the World's Fair. - In the Lectures on Russian Literature (1981), in the essay 'Philistines and Philistinism' the writer Vladimir Nabokov (1899–1977) describes the philistine man and woman as: - In the Lectures on Literature (1982), in speaking of the novel Madame Bovary (1856), about the bourgeois wife of a country doctor, Nabokov said that philistinism is manifest in the prudish attitude demonstrated by the man or the woman who accuses a work of art of being obscene. Notes and References - Webster's New Twentieth Century Dictionary of the English Language – Unabridged (1951) p. 1260 - College Edition: Webster's New World Dictionary of the American Language (1962) p. 1099 - Book: Christian August Vulpius. Curiositäten der physisch- literarisch- artistisch- historischen Vor- und Mitwelt: zur angenehmen Unterhaltung für gebildete Leser. 1818. Im Verlage des Landes-Industrie-Comptoirs. 188. In Jena, vor dem Lobedaer Thore, befindet sich ein Gasthof, genannt zum gelben Engel. Hier gab es im L.1693. Händel, und ein Student wurde in denselben so geschlagen, daß er todt auf dem Plaze blieb. Den Sonntag darauf, predigte der Superintendent Götz heftig gegen diese That, und sagte: Es sey bei diesem Mordhandel hergegangen, wie dort stehe geschrieben: Philister über dir, Simson! Was geschieht? Kaum wurde es Abend, als es auf allen Gassen ertönte: Philister-über dir, Simson! Von dieser Stunde an, hießen die Jenaischen Bürger, Philister. Die Studenten brachten diese Benennung mit auf andere Akademien und endlich kam sie so ziemlich, in's ganze bürgerli che Leben. Die nicht Studenten waren, sollten Philister seyn. Das amusrte. In Jena, war damals das Balgen an der Tagesordnung.. - Book: Friedrich Kluge. Deutsche Studentensprache. 4 June 2012. Walter de Gruyter. 978-3-11-148858-5. 57–. - Benét's Reader's Encyclopedia Third Edition (1987) p. 759 - Book: Notes and Queries. 1872. Oxford University Press. 393–. - Friedrich Kluge, Wortforschung und Wortgeschichte - The New Shorter Oxford English Dictionary (1993), Lesley Brown, Ed., p. 2,186 - Book: Kierkegaard, Soren. The Sickness Unto Death. Princeton University Press. 1980. 0691020280. Princeton, NJ. 41-42. registration. - Nabokov, Lectures on Literature, lecture on Madame Bovary
\|MadSci Network: Physics\| Well, indeed carbon powder is black, but so are magnetic dust particles containing various metal oxides. You may remember from school that a TV is nothing but a cathode ray tube. The electron beam hitting the phosphors on the inside of the front screen is deflected horizontally and vertically by magnetic field oscillations, which create the nice images we see. Hold a magnetic compass near a TV and watch it deviate. Remember the product warnings on good VCR tape packages not to store them near the TV? It is the magnetic field from the rear end of the CRT, which causes the black dust to stick to the TV, whereas organic dust would be blown away by air drafts and convection as on any other surface. So over time a black sticky dust coat covers the TV. The front screen has an additional dust collection effect. The Brems- radiation (X-rays), which are generated, when the electrons hit the screen ionizes the air in front of the screen and in spite of the embedded conductors in the screen it is always on a negative potential (electrons are negative). So the positive parts of the ionized dust in front of the screen gets accelerated towards the screen. So, if you ionize a dust particle containing metal atoms, what do you get? oxidized metals on your screen. Now depending on the chemical nature of your dust this deposit can vary between pitch black or light gray. Try the links in the MadSci Library for more information on Physics.
Study predicts distribution of gravitational wave sourcesDecember 2, 2010 By Tim Stephens in Astronomy & Space / Astronomy (PhysOrg.com) -- A pair of neutron stars spiraling toward each other until they merge in a violent explosion should produce detectable gravitational waves. A new study led by an undergraduate at the University of California, Santa Cruz, predicts for the first time where such mergers are likely to occur in the local galactic neighborhood. According to Enrico Ramirez-Ruiz, associate professor of astronomy and astrophysics at UC Santa Cruz, the results provide valuable information for researchers at gravitational-wave detectors, such as the Laser Interferometry Gravitational-Wave Observatory (LIGO) in Louisiana and Washington. "This is a very important result, as it is likely to significantly alter how gravitational-wave observatories currently operate," Ramirez-Ruiz said. Luke Zoltan Kelley, a UCSC undergraduate working with Ramirez-Ruiz, is first author of a paper describing the new findings, to be published in the December 10 issue of Astrophysical Journal Letters and currently available online. A key prediction of Einstein's general theory of relativity, gravitational waves are ripples in the fabric of space-time caused by the motions of massive objects. Scientists have yet to detect gravitational waves directly because they are so weak and decay rapidly, but a planned upgrade for LIGO (called Advanced LIGO) is expected to greatly increase its sensitivity. Compact binaries--which can consist of two neutron stars, two black holes, or one of each--are among the best candidates for emitting gravitational waves that could be detected by LIGO or other current experiments. Kelley investigated the implications of a key observation about compact binaries: The two objects are not only moving in orbit around each other, they are also typically speeding through space together, their center of mass moving with a velocity that can be well above 200 kilometers per second. "By the time the two objects merge, they are likely to be located far away from the galaxy where they were born," Kelley said. This has implications for efforts to observe mergers that emit gravitational waves. Scientists hope to match a detection at a gravitational-wave observatory with telescope observations of the corresponding merger event. The new study suggests that astronomers might not want to look in the nearest galaxies for these "optical counterparts" of gravitational waves. "Our predictions show that the proposed use of galaxy catalogs for follow-up from possible gravity-wave detections will need to account for the possibility of mergers away from the observed galaxies," Ramirez-Ruiz said. The "kick" that sends compact binaries sailing out of their home galaxies comes from a slight asymmetry in the supernova explosions that give birth to neutron stars and black holes. When a massive star explodes, its core collapses to form either a neutron star (a rapidly rotating ball of densely packed neutrons) or a black hole. According to Kelley, a one-percent asymmetry in the supernova explosion would result in a recoil velocity of about 1,000 kilometers per second (about 2 million miles per hour). "That is around the maximum velocity observed for lone neutron stars and pulsars," he said. "In binary systems, the net kick velocity to the center of mass is noticeably less, and still fairly uncertain, but is around 200 kilometers per second." The researchers used a standard cosmological simulation of dark matter and the formation of structure in the universe to study how different kick velocities would affect the distribution of merging compact binaries. The simulation, run on a supercomputer at UCSC, showed the formation of halos of dark matter whose gravitational pull is thought to drive the formation of galaxies. The researchers populated the more massive halos with tracer particles representing compact binary systems. On separate runs, they gave the binaries different velocities. After running the model for a simulated 13.8 billion years (the current age of the universe), Kelley found a region that looked like our local universe, with a galaxy the size of the Milky Way surrounded by a comparable set of neighboring galaxies. He then generated an image of the sky as it would appear to astronomers in the simulated universe, showing the locations of compact binaries and local galaxies. The results showed that variations in kick velocity lead to marked differences in the distribution of compact binaries. If the merger of a compact binary occurs away from the bright background of a galaxy, it could be detected by a survey telescope such as the planned Large Synoptic Survey Telescope (LSST). The operators of gravitational-wave observatories would then know when and where to look in their data for a gravitational-wave signal, Ramirez-Ruiz said. He and colleagues at UCSC, including theoretical astrophysicist Stan Woosley and graduate student Luke Roberts, are currently trying to work out what the optical signal of a compact-binary merger should look like. "Detecting the optical counterparts of gravitational-wave detections will be a lot easier if they are not within galaxies," Ramirez-Ruiz said. Provided by University of California - Santa Cruz "Study predicts distribution of gravitational wave sources" December 2, 2010 http://phys.org/news/2010-12-gravitational-sources.html
Difference Between Paired and Unpaired Test Paired vs Unpaired Test The t-statistics were developed in 1908 by chemist William Sealy Gosset in Ireland. He used it to monitor the quality of a dark beer called stout while he was working in the Guinness Brewery. He published it in the Biometrika using the pen name “Student.” There are several types of t-tests, the most commonly used are: One sample location test wherein the mean of a population has value in a null hypothesis. A test wherein the slope of a regression line differs notably from 0. Two sample location tests for a difference in mean which can either be paired or unpaired. In a paired test, the data is collected from subjects measured at two different points wherein each subject has two measurements which are done before and after the treatment. Subjects must be paired or matched before collecting data. This is also known as the repeated samples t-test. An example is when comparing the weight loss of a group of people who are being given a special diet. These people are tested before they are started with the new diet and are again tested after they have been on the new diet for a few weeks. The results of both tests which are given to the same set group of people determine how much weight they have lost while on the special diet. Unpaired tests, on the other hand, is when data is collected from two different and independent subjects or patients. The size between the two samples may be equal or not, and it assumes that data gathered is from a normal distribution and that the standard deviation is the same for both samples. An example is the test that is applied to two groups of patients or subjects, those that have cancer and those that don’t. Tests such as this are also called Student’s t-tests wherein variances between the two subject populations are equal. A paired test, therefore, is a test of the null hypothesis that the means of two groups of subjects that are normally distributed are equal while an unpaired test is the test of the null hypothesis that two responses which are measured in the same unit have a difference with a mean value of zero. Both tests assume that all data that have been analyzed are normally distributed. Paired t-tests are more comprehensive and compelling than unpaired t-tests because they are done with subjects that have similar characteristics. 1.A paired test is the test of the null hypothesis that the means of two subjects are equal while an unpaired test is the test of the null hypothesis that the difference between subjects has the mean value of zero. 2.A paired test is also known as a repeated samples t-test while an unpaired test is also known as a Student’s t-test. 3.A paired test is done on subjects that are similar or paired before data is collected and two tests are done before and after a treatment while an unpaired test is done on two independent subjects. Search DifferenceBetween.net : Email This Post : If you like this article or our site. Please spread the word. Share it with your friends/family. Leave a Response
Hardening of the arteries (also called atherosclerosis), is a common disorder. It occurs when fat, cholesterol, and other substances build up in the walls of arteries. These deposits form hard structures called plaques. Over time, these plaques can block the arteries and cause problems throughout the body. Atherosclerosis; Arteriosclerosis; Plaque buildup - arteries Hardening of the arteries is a process that often occurs with aging. As you grow older, plaque buildup narrows your arteries and makes them stiffer. These changes make it harder for blood to flow through them. Blood clots may form in the narrowed arteries and block blood flow. Pieces of plaque can also break off and move to smaller blood vessels. This can block blood flow. When blockages occur, blood and oxygen cannot reach the tissues. This can result in tissue damage or death of the tissue. Artery blockage is a common cause of heart attack or stroke. High blood cholesterol levels can cause hardening of the arteries at a younger age. For many people, high cholesterol levels are the result of an - Family history of hardening of the arteries - High blood pressure Hardening of the arteries does not cause symptoms until blood flow to part of the body becomes slowed or blocked. If the arteries to the heart become narrow, blood flow to the heart can slow down or stop. This can cause chest pain (angina), shortness of breath, and other symptoms. Narrowed or blocked arteries may also cause problems and symptoms in your intestines, kidneys, legs, and brain. Exams and Tests A health care provider will perform a physical exam and listen to the heart and lungs with a stethoscope. Hardening of the arteries can create a whooshing or blowing sound ("bruit") over an artery. Some guidelines recommend having your first cholesterol test at age 20. Everyone should have their first screening test by A number of imaging tests may be used to see how well blood moves through your arteries. - Doppler tests use ultrasound or sound waves. Magnetic resonance arteriography(MRA) is a special type of MRI scan - Special CT scans called CT angiography Arteriograms or angiographyuse x-rays to see inside the arteries Lifestyle changes can reduce your risk of hardening of the arteries: - Quit smoking. This is the single most important change you can make to reduce your risk of heart disease and stroke. - Avoid fatty foods. Eat well-balanced meals that are low in fat and cholesterol. Include several daily servings of fruits and vegetables. Adding fish to your diet at least twice a week may be helpful. However, do not eat fried fish. - Limit how much alcohol you drink. The safe limit is one drink a day for women and two a day for men. - Stay physically active. Get 30 minutes a day of exercise if you are not overweight, and for 60to 90 minutes a day if you are overweight. Talk to your doctor before starting a new exercise plan. This is very important if you have been diagnosed with heart disease or you have had a heart attack. Get your blood pressure checked every 1to 2 years before age 50 and yearly after age 50. Have your blood pressure checked more often if you have high blood pressure, heart disease, or you have had a stroke. Talk to your doctor about how often you should have your blood pressure checked. If your blood pressure is high, it is important for you to lower it and keep it under control. - Everyone should keep their blood pressure below 140/90 mmHg. - If you have diabetes, kidney disease, or have had a stroke or heart attack, your blood pressure target may be lower. Ask your doctor what your blood pressure should be. Your doctor may want you to take medicine for high cholesterol levels if lifestyle changes do not work. This will depend on: - Your age - Whether you have heart disease or other blood flow problems - Whether you smoke or are overweight - Whether you have high blood pressure or diabetes Your doctor may tell you to take aspirin or another medicine to help prevent blood clots in your arteries. These medicines are called antiplatelet drugs. DO NOT take aspirin without first talking to your doctor. Hardening of the arteries cannot be reversed once it is started. However, lifestyle changes and treating high cholesterol levels can prevent or slow the process. In some cases, the plaque can cause a weak spot in the wall of an artery. This can lead to a bulge in an artery called an Genest J, Libby P. Lipoprotein disorders and cardiovascular disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwalds Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 47. Libby P. The vascular biology of atherosclerosis. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwalds Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 43. Hansson GK, Hamsten A. Atherosclerosis, thrombosis, and vascular biology. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 70. David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.
What is an Opioid? Opioids are chemical substances which act on opioid receptors on nerve cells in the brain and nervous system resulting in the production of morphine-like effects. In medicine, they are principally used in relieving pain for anesthesia and the suppression of diarrhea. What is opioid epidemic? An opioid epidemic or opioid crisis can be defined simply as an opioid dependence behavior involving a disproportionately large number of people beyond what is normally expected within a given population. Opioid Crisis Statistics According to the Center for Disease Control and Prevention (CDC), 91 Americans die from opioid overdose every day and over five hundred thousand Americans have died between 2000 and 2015. Available data from the American Society of Addiction Medicine (ASAM) indicates that over 20 .5 million Americans aged 12 or older had a substance use disorder in 2015 , of this figure 10 % were related to the abuse of opioid containing prescription pain relievers. The amount of prescription opioids sold to pharmacies, hospitals, and doctors’ offices have also quadrupled and in 2011, deaths from prescription opioid overdoses overtook the combined fatalities from heroin and cocaine. Opioid Crisis by State The states most affected by the American opioid crisis, are: West Virginia, New Hampshire, Kentucky and Ohio. Available data shows that rates of death from opioid overdoses in West Virginia’s is 35 per 100,000 people while the national rate of deaths from opioid overdoses is around 10 per 100,000 people Examples of Opioid Drugs Commonly Abused Although opioids are a vital component of modern medicine owing to their successes in helping cancer patients and others cope with acute pain the growing narcotic crisis is complicating efforts towards improving the already challenging mental health dilemma across America. The increase dependence on narcotic substances by a growing number of the population has reached unprecedented levels forcing local health officials to seek badly needed higher level assistance to curb a menace that is threatening to destroy the foundations of our societies. In this piece we x- ray the impact of codeine and hydrocodone and how they breed dependence and destroy lives. Codeine vs Hydrocodone Codeine is an opiate that is often used to treat mild to moderate pain, cough, and for diarrhea. It is related to morphine but with mild sedative effect and less potent analgesic properties. Although the mechanism of action of codeine is not completely known to science, the drug is known to act centrally to suppress cough. On the other hand, Hydrocodone are produced from a synthetic molecule in the mode of the natural constituent of the opium poppy flower. The drug is a schedule C-III narcotic substance that acts on the central nervous system in the same way as its naturally occurring family members such as codeine and morphine. The primary reason for prescribing hydrocodone based cough medicines is to alleviate chronic coughing that can accompany conditions such as lung cancer. Examples of hydrocodone containing syrups are Tussionex, Novasus, Tussicaps, Hytan and S-T Forte. What is the difference between codeine and hydrocodone? Although, they are similar in many ways because they are both synthetic opiates, the two molecules also differ in many ways Codeine vs Hydrocodone Similarities - Codeine and hydrocodone are opioid medications. - They both work by altering your perception of pain. - They are both effective painkillers. - Codeine and hydrocodone are available in immediate-release oral tablets - In terms of side effects , taking codeine or hydrocodone can cause dizziness, drowsiness, constipation, nausea and vomiting - Long-term use of codeine and hydrocodone can lead to dependence and addiction. - Each is available only on prescription. Codeine vs Hydrocodone Differences - Codeine is typically prescribed for mild to moderate pain, while hydrocodone is often used for more severe pain. - Hydrocodone is only available in immediate-release oral tablets, when it is combined with other analgesics such as acetaminophen. - In terms of side effects taking codeine can cause additional side effects such as lightheadedness, shortness of breath or sweating while hydrocodone can cause itching and loss of appetite. The use of codeine and hydrocodone for an extended period of time also have other far reaching consequences such as the increased risk of urinary retention, infections, and liver damage. With over two million Americans becoming dependent on prescription pain pills annually, it will take more than a declaration of an opioid emergency to halt the current unacceptable loss of lives in Gods own Country.
Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor by Staff Writers North Pole (SPX) Aug 25, 2011 You can't get any "higher": on 22 August 2011 at exactly 9.42 a.m. the research icebreaker Polarstern of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association reaches the North Pole. The aim of he current expedition is to document changes in the far north. Thus, the researchers on board are conducting an extensive investigation programme in the water, ice and air at the northernmost point on the Earth. The little sea ice cover makes the route via the pole to the investigation area in the Canadian Arctic possible. Sea ice not only plays a role in the selection of the route, but is above all a major research focal point. How thick is the ice and how old? To what extent has it been deformed by pressure - is there snow or puddles of melting water on it? Satellite measurements, too, supply ice information, but measurements are still required on site to be able to interpret these data correctly. Light energy causes the ice to melt and heats up the water in the summer months. The warming of the Arctic and the related changes in heat and gas exchange processes between the ocean, sea ice and atmosphere are the paramount focus of the investigations. The oceanic currents that exchange water masses with the Atlantic and the Pacific are also undergoing change. Redistribution of the freshwater input from rivers into the Arctic Ocean is one of the factors that influence these oceanic currents. Light is the source of energy for tiny algae that live in and under the ice and form the basis of the food web in the Arctic Ocean. Biologists classify species and determine the number of algae as well as the small and larger animals that feed on them. The researchers follow the path taken by the organisms from the water surface to the seafloor, where the remains end up as organic substance at a depth of thousands of metres after the organisms die. These deposits on the seafloor permit conclusions to be drawn on how living conditions were in the course of the Earth's history. After all, the sediments and the animal and plant remains they contain are up to several million years old. Following the expedition, sediment cores will be analysed in the laboratory. To improve the models of the Earth's climate history, chemists, physicists and oceanographers additionally examine the environmental conditions in the present-day oceans. They draw conclusions on how fast organic substance is transformed and relocated as a result of altered current conditions. All 55 scientists and technicians from six countries on board the Polarstern have a common goal: studying the changes in the Arctic. This is also reflected in the name of the expedition "TransArc - Trans-Arctic survey of the Arctic Ocean in transition". The researchers have been investigating their questions jointly with the 43 crew members since the Polarstern left the port of Tromso (Norway) on 5 August. The first ice floes appeared on 8 August. Since 9 August the Polarstern has been sailing through dense pack ice on the route along 60 degrees East in temperatures of around 0 degrees C. At first it was predominantly one-year-old sea ice, now older and consequently thicker ice floes appear. "From a scientific point of view the North Pole is not more interesting than other places in the Arctic," reports Prof. Ursula Schauer from on board the Polarstern. The oceanographer at the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association is the chief scientist of the expedition. "The expected changes are rather minor here. However, the northern part of the Canadian sector of the Arctic still numbers among the least researched regions on the globe because of the dense pack ice." Schauer was in the central Arctic the last time in 2007 and is now experiencing a similarly small ice cover as the year that went down in the annals as the one with the lowest extent of sea ice since the beginning of satellite measurements in 1979. Initial measurements of the ice thickness confirm this: in 2011 as well as in 2007 the most frequently occurring ice thickness was 0.9 metres. As a comparison, the most frequently measured ice thickness in 2001 was around 2 metres. In that year the extent of the ice cover at the end of the melting period corresponded roughly to the long-term mean. The Polarstern is at the North Pole for the third time in its history. On 7 September 1991 it was one of the first two conventionally driven ships to sail there, along with the Swedish research icebreaker Oden. Almost exactly ten years later, on 6 September 2001, it carried out a joint expedition at the North Pole together with the American research icebreaker Healy. After the investigations at the North Pole and subsequently in the Canadian Basin the vessel will head for the Siberian Sea. The researchers want to study the oceanic circulation from the deep sea to the shallow shelf seas and habitats from the ice edge to the ice-free ocean. Beyond the Ice Age \|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement\|
The Hellenistic era extends from the death of Alexander the Great in 323 BCE to the conquest of Egypt by the Romans in 30 BCE. Though defined in terms of political events, it is also host to distinctive developments in Greek intellectual life. Chief among these are the foundation and consolidation of organized schools as the focus of philosophical life, especially in Athens; the growing independence of various special sciences from their original philosophical context; and a geographical expansion (in the wake of Alexander's conquests and the foundation of Greek-speaking kingdoms in the eastern Mediterranean) that had significant long-term consequences. The intellectual life of Hellenistic Greece changed again as Roman political authority gradually came to dominate in the region. Throughout this period, Greek intellectuals (both philosophers and scientists) became more prominent and important in civic life, often achieving political recognition even in foreign cities; in 155 BCE three prominent philosophers, none of them from Athens, were chosen to represent the city on an embassy to Rome. Prominent intellectuals were offered patronage by the new Hellenistic kingdoms. The first major organized school at Athens was the Academy, founded by Plato. Aristotle's associate and successor, Theophrastus, and later Strato of Lampsacus, carried on the traditions of his work in the Lyceum. Other philosophical schools in the fourth century were of minor importance, although the hedonistic school based at Cyrene in North Africa was influential. Yet within the first few decades of the Hellenistic era two major new schools, representing significant philosophical directions with lasting influence, were established. Epicurus, the founder of Epicureanism, was an Athenian and established the Garden there, but his followers spread around the Aegean basin in a network of smaller institutions that remained connected to the original school. Zeno came from the town of Citium on the island of Cyprus to establish his school in the Painted Stoa in the Athenian agora, and throughout its history it continued to attract philosophers from all over the Hellenistic Greek world, especially Asia Minor. Epicureanism and Stoicism quickly became successful and attracted adherents for centuries to come. Epicureanism revived the atomistic physics pioneered by Leucippus and Democritus and linked it tightly with a hedonistic ethics and quietistic political philosophy. Stoicism depended on the mainstream Socratic tradition; its cosmology and physics drew primarily on Plato and Aristotle and its ethical and political theory were heavily influenced by Socratic ideas colored by the Cynic tradition stemming from Diogenes of Sinope and Crates of Thebes. Stoicism and Epicureanism were in some ways polar opposites. The former championed god's providence while Epicurus denied it. Stoic physics asserts the continuity of all matter (which is itself permeated by a divine cause giving it form), while for Epicurus all things, even the gods, are composed of atoms and void. Like Plato and Aristotle, Stoics believed that society and its institutions rest on deeply rooted features of human nature, but Epicureans held that societies are formed by agreements among people about mutual preservation and advantage. Stoicism (inspired in part by the dialectical school and Megarian philosophers) led the way in the development of logic and dialectic, while Epicurus rejected logic along with many other specialized intellectual endeavors as useless. For Epicurus even physics mattered only in so far as it was essential to achieving tranquility. Despite these contrasts, the two schools shared a great deal. Both rested their philosophy on broadly empiricist epistemologies, according to which normal sensory experience was the ultimate source and criterion for knowledge, and both rejected the idea of causally efficacious incorporeal entities and emphasized the material foundations of all reality. Neither school could accept the central role of form, either in the Platonic version in which forms were separate from material particulars, or in the immanentist version of Aristotle, for whom form and matter were the two components of all concrete objects; nor could they embrace the concepts of an incorporeal deity or an immortal and incorporeal soul animating the body. As these new schools emerged, the Academy changed its intellectual course; under the leadership of Arcesilaus it adopted a skeptical practice, devoting its energies not to the development and refinement of positive theories but to the dialectical criticism of those philosophers who claimed certainty for their own views. Stoicism was its chief target, and it can be argued that the main inspiration for this skeptical turn was the desire to refute those who claimed that the physical world could yield certain knowledge. The Academy maintained its dialectical approach for nearly two centuries; its high point came under the intellectual leadership of Carneades in the second century BCE. His followers came to disagree about the nature of his commitment to skepticism and gradually reverted to dogmatism, the conviction that knowledge is achievable. The Lyceum (sometimes also called the Peripatos) did not long maintain its philosophical vigor after the death of Theophrastus and its leaders became better known for their achievements in the sciences than in philosophy. Only Critolaus, the contemporary of Carneades, achieved importance in philosophy proper. The renewal of Aristotelianism had to await the end of the Hellenistic era. With each generation the Stoic school changed and developed, with most of its leaders making significant innovations. The third head, Chrysippus of Soli, systematized and reworked nearly every aspect of Stoic thought, developed the formal logic for which the Stoics remained famous until the end of antiquity, and exerted control of the school's trajectory for several generations after. In the late second century Panaetius of Rhodes and his student Posidonius of Apamea made a comparable mark, reintegrating Platonic and Aristotelian influences into the school's intellectual life. By contrast, in all but details the Epicurean school was marked by conservatism and doctrinal unity. The interaction between philosophical schools and the special sciences is a topic of particular interest in this period. Except for the medical texts in the Hippocratic Corpus, there are few traces of specialized scientific writing before 300 BCE, although Aristotle makes frequent allusions to an optical and astronomical literature that was distinct from philosophy and had a mathematical character. Hellenistic optics, as represented by Euclid's Optics, was the physical science that engaged most actively with philosophy. Euclid uses a geometrical apparatus to model a selection of phenomena of visual perception that reflect not only Aristotle's analysis of the objects of sense perception but also contemporary Hellenistic epistemological concern with the reliability of the senses. The Euclidean model, invoking rectilinear "visual rays" that radiate from eye to object, could be reconciled with Stoic physics as well as with the more eclectic materialism of Theophrastus and his Peripatetic successors. Astronomy, by contrast, seems to have disengaged from philosophy after Aristotle. Deeply impressed by the regularity of astronomical phenomena and by Eudoxus's ingenious hypotheses of rotating spheres that seemed to account for them, Aristotle posited a sharp discontinuity between the irregularly changeable globe of matter at the centre of the cosmos, in which we dwell, and the eternally unchanging outer shell, composed of a distinct kind of matter, that is the realm of the sun, moon, planets, and stars. The Stoics and Epicurus, by rejecting this discontinuity, made it harder to reconcile their physics with the mathematically abstract celestial models of the astronomers. Astronomical writers such as Aristarchus in the third century and Hipparchus in the second relied on geometry, arithmetic, and optical observation as criteria for their models, and sometimes put forward alternative models to explain the same phenomena. In the view of a physically oriented philosopher such as Posidonius, the astronomers' models did not constitute proper explanation, which only the philosophers could provide. Nonetheless such results of astronomical reasoning as estimates of the sizes and distances of the sun and moon and Eratosthenes's measurement of the earth's circumference became commonplaces of philosophical discourse. Mesopotamian traditions of divination from celestial phenomena were known in the Greek world as early as the third century, and the Stoics in particular took a lively interest in them as they did in other forms of divination. It was only about the beginning of the first century BCE, however, that a distinctly Greek astrology endowed with sufficient complexity and rationale to claim scientific status took form. Astrology was founded on a physical cosmology that was loosely derived from Peripatetic and Stoic physics, though most of its literature concerned niceties of prognostication, not the analysis of cause and effect. The Stoic poet Aratus's versified description of the constellations achieved remarkable popularity in antiquity; but on the whole the Stoics tended to disregard technical astronomy, perhaps because they were uncomfortable with its mechanistic character. The Skeptical schools, on the other hand, found an easy target in astrology's pretensions to exact knowledge of the future derived from inexactly observed or calculated motions of the heavenly bodies. The Hellenistic period was the heyday of Greek geometry. Euclid, Archimedes, Apollonius of Perge, and a host of lesser mathematicians published work of enduring value on difficult problems, typically involving the properties of curves and the areas and volumes bounded by geometrical figures. Much mathematical research was motivated by optics, mechanics, and astronomy, but Hellenistic mathematicians seem to have kept more aloof from the philosophers than their predecessors of Plato's and Aristotle's time. Alone among the scientific disciplines, medicine was characterized in the Hellenistic period by a division into sects or schools, comparable to the contemporary emergence of the great philosophical schools. The Hellenistic medical sects took their start from the prolific early third century physicians Herophilus and Erasistratus, whose theoretical pronouncements on physiology and medical practice were founded on a level of anatomical research and experimentation (reportedly including human vivisections) that was unprecedented in Greek medicine. In their approaches to physical and biological explanation these men and their followers owed something to Aristotle and perhaps more to the later Peripatetics. The "Herophilean" and "Erasistratean" schools seem to have less direct engagement with Stoicism or Epicureanism, though in common with those philosophical sects they accepted that knowledge of hidden causes of phenomena was both possible and useful. The medical sect of Empiricists, which rose in the third century, rejected hidden causes as both unknowable and unhelpful in medical practice, and advocated instead a strategy for progressing systematically from individual trial-and-error experience to generalized, teachable practical knowledge without recourse to anatomical or physiological theory. The debates between the Empiricists and the other sects, grouped under the heading of Rationalists or Dogmatists, centered on both epistemology and research ethics; Empiricist physicians found natural intellectual allies in the philosophical Skeptics, especially the Pyrrhonists. Few Hellenistic physicians, however, were themselves philosophers, and a broad, intellectually respectable effort to bring together the many threads of current medical and philosophical thought had to wait for Galen in the second century CE. Galen's contemporary Ptolemy had a comparable reintegrating role with respect to Hellenistic physical science and philosophy. The relationship between philosophy and medicine was paralleled by that between philosophical analysis of language and the emerging disciplines of grammar and philology. While critical speculation about language began in the Presocratic period and developed dramatically in the fourth century BCE, in the Hellenistic era the study of language achieved greater independence from philosophy without fundamentally severing its ties. Pergamum and Alexandria became centers for the critical study of ancient texts, especially Homer, and for the analysis of linguistic phenomena. At the same time, Epicureanism promoted a naturalistic understanding of the origin and nature of language and the Stoics made enormous advances not just in the area of logic (Chrysippus developed propositional logic in contrast to Aristotelian term logic) but also in the analysis of the parts of speech and semantic theory. Philosophers and grammarians debated the roles of rule-driven morphological analogy and the variability of actual linguistic usage (anomaly ) in the determination of linguistic norms. Here too Hellenistic developments laid the foundations for intellectual life in later antiquity. At the end of the Hellenistic era, the dominance of Athens in Greek philosophical life came to an end. After the conquest of Athens by the Romans under Sulla during the Mithridatic wars (88–86 BCE), philosophy, like science, spread out around the Mediterranean world. Rome itself, as well as Alexandria and Rhodes, became an important locus of philosophical activity as the Hellenistic age, and with it the Roman Republic, came to an end. At the beginnings of the Roman Empire, philosophy changed its character and turned for inspiration to the close study of the classic texts of Plato and Aristotle written centuries before. The Hellenistic era in Greek thought came to an end appropriately with the rise of a productive form of scholasticism and the revival of the classical schools of thought which have remained central to our understanding of ancient philosophy ever since. See also Ancient Skepticism; Arcesilaus; Aristotelianism; Carneades; Chrysippus; Cyrenaics; Epicurus; Greek Academy; Panaetius of Rhodes; Posidonis; Stoicism; Strato and Stratonism; Theophrastus; Zeno of Citium. For philosophical developments in the period the starting point is The Cambridge History of Hellenistic Philosophy (ed. K. Algra et al, Cambridge, U.K.: Cambridge University Press, 1999). Major texts and philosophical commentary are found in A. A. Long and D. N. Sedley, The Hellenistic Philosophers (2 vol.; Cambridge, U.K.: Cambridge University Press, 1987). For the sciences, G. E. R. Lloyd's Greek Science after Aristotle (London: Chatto and Windus, 1973) remains fundamental. For optics and its philosophical setting see Gérard Simon, Le regard l'être et l'apparance dans l'optique de l'antiquité (Paris: Seuil, 1988). H. von Staden, Herophilus: the art of medicine in early Alexandria: edition, translation and essays (Cambridge, U.K.: Cambridge University Press, 1989) and S. Cuomo, Ancient Mathematics (London: Routledlge, 2001) illuminate the intellectual world of Hellenistic medicine and mathematics. Brad Inwood (2005) Alexander Jones (2005) "Hellenistic Thought." Encyclopedia of Philosophy. . Encyclopedia.com. (August 18, 2018). http://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/hellenistic-thought "Hellenistic Thought." Encyclopedia of Philosophy. . Retrieved August 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/hellenistic-thought
Redirected from Proportionality constant For example, if you travel at a constant speed, then the distance you cover and the time you spend are proportional, the proportionality constant being the speed. Similarly, the amount of force acting on a certain object from the gravity of the Earth at sea level is proportional to the object's mass. To test whether x and y are proportional, one performs several measurements and plots the resulting points in a Cartesian coordinate system. If the points lie on (or close to) a straight line passing through the origin (0,0), then the two variables are proportional, with the proportionality constant given by the line's slope. The two quantities x and y are inversely proportional if there exists a non-zero constant k such that
Another common way to represent graphs is to use incidence matrices. Let be an undirected graph. Suppose that are the vertices and are the edges of G. Then the incidence matrix with respect to this ordering of V and E is the matrix , where . Example. Represent the graph shown in Figure below with an incidence matrix. Solution: e1 e2 e3 e4 e5 e6 Incidence matrices can also be used to represent multiple edges and loops. Multiple edges are represented in the incidence matrix using columns with identical entries, since these edges are incident with the same pair of vertices. Loops are represented using a column with exactly one entry equal to 1, corresponding to the vertex that is incident with this loop. Example. Represent the pseudograph shown in Figure below using an incidence matrix. Solution: e1 e2 e3 e4 e5 e6 e7 e8 Date: 2015-01-02; view: 1074
The house fly is, perhaps, the most common and widespread animal in the world (3). It is a serious pest, which spreads many disease-causing pathogens including Salmonella, anthrax and polio (4). It is greyish in colour with four dark stripes along the back (4). Like all flies it has one pair of membranous 'true' wings; the second pair of wings are modified into drumstick-like appendages known as 'halteres', which are used in balance. The sponge-like mouthparts are adapted for feeding on liquids, and the reddish compound eyes are large (5). House flies contaminate food, and in developing countries are responsible for millions of infant deaths per year as a result of dehydration caused by diarrhoea (5). House flies undergo 'complete metamorphosis'; the larvae (maggots) progress through three stages known as 'instars' before a pupal stage develops in which complex changes take place as the body of the maggot re-organises into the adult fly (4). Adults feed on rotting plant and animal matter and sugary liquids. They repeatedly salivate on food, ingest it and regurgitate it in order to pre-digest the food (4). Type of insect development (also known as holometabolous development) in which there is a distinct larval and pupal stage. The larval stage is different to the adult in terms of both structure and diet, and the pupa is a relatively inactive stage in which the larval tissues are broken down and rearranged into adult structures. Stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce. Stage in an insect's development, when huge changes occur that reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis. Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.
\|In Texas, USA\| The loggerhead shrike (Lanius ludovicianus) is a passerine bird. It is the only member of the shrike family endemic to North America; the related northern shrike (L. excubitor) occurs north of its range but also in the Palearctic. The bird has a large hooked bill; the head and back are grey and the underparts white. The wings and tail are black, with white patches on the wings and white on the outer tail feather. The black face mask extends over the eye, unlike that of the similar but slightly larger northern shrike. "Loggerhead" refers to the relatively large size of the head as compared to the rest of the body. The bird breeds in semi-open areas in southern Ontario, Quebec and the Canadian prairie provinces, south to Mexico. It nests in dense trees and shrubs. The female lays 4 to 8 eggs in a bulky cup made of twigs and grass. There is an increase in average clutch size as latitude increases. The shrike is a permanent resident in the southern part of the range; northern birds migrate farther south. The bird waits on a perch with open lines of sight and swoops down to capture prey. Its food is large insects, small birds and lizards. Known in many parts as the "butcher bird," it impales its prey on thorns or barbed wire before eating it, because it does not have the talons of the larger birds of prey. The bird decorates its impaled victim with feathers and bills in order to attract a mate. Loggerhead shrikes are perhaps the only known predators of eastern lubber grasshoppers (Romalea guttata) and will consume the head and abdomen of these very large insects, leaving behind the poisonous and foul-tasting thorax. The population of this species has declined in the northeastern parts of its range, possibly due to loss of suitable habitat and pesticide use. The eastern loggerhead shrike (L.l. migrans) is critically endangered in Canada. (Although only one island subspecies is legally listed as endangered in the United States, the species is declining continentwide and no longer occurs in most of the northeastern U.S.) A captive population was established at the Toronto Zoo and McGill University in 1997. In 2001 an experimental field breeding and release program managed by Wildlife Preservation Canada was established. "Field breeding" refers to moving captive pairs from their wintering cages at the Toronto Zoo and McGill to large enclosures within shrike habitat in Ontario where the pairs nest and raise their young and then the young are released to the wild when they'd naturally disperse from their parents. Since 2004, over 90 young have been released annually and between 2% and 6.5% of young released have successfully migrated and returned to breed in the subsequent year. There are ten recognized subspecies of loggerhead shrike: - Lanius ludovicianus anthonyi - Lanius ludovicianus excubitorides - Lanius ludovicianus gambeli - Lanius ludovicianus grinnelli - Lanius ludovicianus ludovicianus - Lanius ludovicianus mearnsi (San Clemente loggerhead shrike) - Lanius ludovicianus migrans - Lanius ludovicianus nelsoni - Lanius ludovicianus sonoriensis - BirdLife International (2012). "Lanius ludovicianus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013. - Loggerhead Shrike. National Audubon Society - Keinath, Douglas A and Schneider, Catherine (February 2005) Species assessment for Loggerhead shrike (Lanius ludovicianus) in Wyoming. blm.gov - Yosef, Reuven. (1996). "Loggerhead Shrike (Lanius ludovicianus)" in The Birds of North America Online. A. Poole (Ed.). Ithaca: Cornell Lab of Ornithology - "Toronto Zoo > Conservation > Birds". Retrieved 2009-09-22. - Eastern Loggerhead Shrike. Wildlife Preservation Canada \|Wikimedia Commons has media related to Loggerhead Shrike.\| \|Wikispecies has information related to: Lanius ludovicianus\| - The Ontongeny of Cricket and Mouse Killing in the Loggerhead Shrike - The Effects of Dieldren on the Behavior of Young Loggerhead Shrikes - Loggerhead Shrike Species Account – Cornell Lab of Ornithology - Loggerhead Shrike – Lanius ludovicianus – USGS Patuxent Bird Identification InfoCenter - Stamps (for Mexico) with Range Map at bird-stamps.org - Loggerhead Shrike videos, photos, and sounds at the Internet Bird Collection - Loggerhead Shrike Bird Sound at Florida Museum of Natural History - Loggerhead Shrike photo gallery at VIREO (Drexel University)
Working on identifying complete and incomplete sentences? Your students will get plenty of practice identifying a complete or incomplete sentence with these 24 task cards. Each card has a sentence on it that is either complete or incomplete. Task cards are great for test prep and practice. Use them in small groups, or individually at a literacy center. You can also play a game of SCOOT with them. Detailed directions for SCOOT are included in case you aren't familiar with it. Students answer each question on the provided answer sheet. An answer key is also included. Contents of this set include: • Directions and Suggestions • 24 Task Cards (both in color and black/white) • Student Answer Sheet and Answer Key Download the preview to see a sample of the pages included in the packet. You might also like: Singular and Plural Nouns Types of Sentences VERBS – Become a Verb Superhero! Common and Proper Nouns Visit My TPT Store Come Collaborate with me! Blog (Smith’s Safari Adventures – Tracy Smith) Want to receive email updates when I post new products, freebies, and SALES? Click the green star at the top to start following my store! © Tracy Smith 2017
- The definition of a handicap is a race where the competition is evened out by giving advantages to the weaker competitor and making the race more difficult for the stronger competitor, or something that is a disadvantage. - An example of a handicap is a race where heavier people have to carry less weight and the lighter people have to carry more weight. - An example of a handicap is a broken leg. - Handicap is defined as to cause a disadvantage. An example of handicap is to pour a slippery substance over an obstacle course. - a race or other competition in which difficulties are imposed on the superior contestants, or advantages given to the inferior, to make their chances of winning equal - such a difficulty or advantage - something that hampers a person; disadvantage; hindrance - a physical or mental disability Origin of handicaporigin, originally a game in which forfeits were drawn from a cap or hat ; from hand in cap - to give a handicap to (contestants) - to cause to be at a disadvantage; hinder; impede - Sports & Games a. A race or contest in which contestants are given advantages or compensations to equalize the chances of winning.b. Such an advantage or penalty. - Usage Problem A physical or mental disability. See Usage Note at handicapped. - A disadvantage or inconvenience. See Synonyms at disadvantage. transitive verbhand·i·capped, hand·i·cap·ping, hand·i·caps - Sports & Games To assign handicaps or a handicap to (a contestant). - To cause to be at a disadvantage; impede. Origin of handicapFrom obsolete hand in cap, a game in which forfeits were held in a cap. - Something that prevents, hampers, or hinders. - Age is often a handicap. - An allowance of a certain amount of time or distance in starting, granted in a race (other contest of skill) to the competitor possessing disadvantages; or an additional weight or other hindrance imposed upon the one possessing advantages, in order to equalize, as much as possible, the chances of success. - The older boy won, even though his opponent had been granted a handicap of five meters. - A handicap in chess often involves removal of the queen's rook. - (sometimes considered offensive) The disadvantage itself, in particular physical or mental disadvantages of people. - A race, for horses or men, or any contest of agility, strength, or skill, in which there is an allowance of time, distance, weight, or other advantage, to equalize the chances of the competitors. (third-person singular simple present handicaps, present participle handicapping, simple past and past participle handicapped) - To encumber with a handicap in any contest. - (by extension) To place at disadvantage. - The candidate was heavily handicapped. - To estimate betting odds. - Grandpa Andy would buy the racing form the day ahead of time so he could handicap the race before he even arrived at the track.
MAKING STRONG CHARACTERS What Contributes To A Character’s Uniqueness: - Name: The word or nickname phrase by which a character is designated. Harsh consonants give the impression of strength and perseverance. Softer sounds give the impression of gentleness. - Dialect: The phonology, grammar, and vocabulary style used by a character. It should reflect character’s age, background, and verbal mannerisms. - Physical Attributes: The body characteristics of a character, including age and weight, body features and shape, eye and hair color, glasses, contacts; hair length, and distinguishing marks. - Habits: The acquired patterns of behavior such as preferences of music and books, attend concerts, frequent museums, food preferences, favorite restaurants, bad habits–smoking, drinking, and preferences for perfume and cologne, and mannerisms. - Clothing: The type normally worn makes a statement about a character. - Personality Traits: The visible aspects of a character as he/she impresses others; faults and strengths; likes and dislikes; fears and favorites. - Personal History: The events, acts, and ideas from a character’s past that has influenced him such as childhood diseases, education, emotional traumas, religious beliefs, family and friend relationships, and love relationships, career, and talents. - Goals: The achievement for which a character struggles, can be immediate or long range. - Body Language: The physical expressions in response to emotions, events, people, or things around a character. Tips For Showing Strong Characters: - Vary beginning letter, length, sound of names of characters - Use a character chart to know the character thoroughly (should include all of the above) - Use the most dominant impressions often, use them consistently (adjective and noun for quick description–prim lady, grinning devil) - Make each character unique in some special way - Use multiple facets of a character to have him reacting to all the various emotions (laughing, crying, teasing, loving) - Use specifics to give the character a feeling of being real (Armani suit, rose cologne) - Give the character a goal worth dying for (defending home/family, foiling a takeover) - Give the character a strong motivation (reason for giving his all to reach a goal) - Give the character an Achilles heel (one vulnerable spot) Lifetraps For Strong Internal Conflict In Characters: - Abandonment–emotionally isolated in some way; see friendships/relationships as unstable - Mistrust and Abuse–expect people to hurt or take advantage of them; avoid relationships; abused physically, verbally, or sexually - Emotional Deprivation–believe no one cares for them; disconnected and lonely - Social Exclusion–isolate self from rest of world; self-conscious; feel inferior - Dependence–need constant support; can’t make own decisions; feel inept and overwhelmed - Vulnerability–don’t feel safe in the world; have anxiety attacks - Defectiveness–feel inwardly flawed, unlovable; unworthy of love - Failure–believe inadequate in areas of achievement - Subjugation–sacrifice own needs to please others; allow others to control them through guilt or fear; avoid confrontations - Unrelenting Standards–strive relentlessly; judge self by rigid set of standards; very competitive - Entitlement–spoiled as children; don’t accept restrictions; can’t take no for an answer; easily frustrated; act on impulse and emotion © 2010 Starla Kaye
As an oceanic plate descends to hotter depths beneath the overriding plate, it is heated and releases water. The presence of hot, water-rich liquids causes the overlying rock to begin melting. The resulting magma is less dense than the surrounding rock, so it rises up toward the surface where it collects in magma chambers. Volcanic eruptions happen when magma from these chambers reaches the surface. Over millions of years, repeated eruptions build volcanic mountains on the overriding plate. ! Click the image to see the animation.
The idea to sequester carbon is gaining support as a way to avoid global warming. For example, the European Union plans to invest billions of Euros within the next ten years to develop carbon capture and storage whereby CO2 will be extracted at power plants and other combustion sites and stored underground. But how effective is this procedure and what are the long-term consequences of leakage for the oceans and climate? A Niels Bohr Institute researcher has now cast light upon these issues. This research has just been published in the scientific journal, Nature Geoscience. Large scale use of carbon sequestration could help to avoid extreme global warming that would otherwise occur in the near future unless fossil fuel emissions are reduced significantly. But it is not clear how effective different types of sequestration are in the long run, owing to leakage of stored CO2 back out to the atmosphere. Nor is it clear what would be the long-term consequences of such leakage for the Earth's environment. Gary Shaffer, professor at the Niels Bohr Institute, and leader of the Danish Center for Earth System Science, made long model projections for a number of sequestration/leakage scenarios. His results show that leakage of the stored CO2 may bring about large atmosphere warming, large sea level rise and oxygen depletion, acidification and elevated CO2 concentrations in the ocean. Storage of CO2 in the deep ocean is a poor choice since this creates grave problems for deep sea life and since CO2 stored this way returns to the atmosphere relatively quickly, bringing back the global warming. Geological storage may be more effective in delaying the return of the warming and associated consequences but only if a CO2 leakage of 1 % or less per thousand years can be obtained. A burden for future society Alternatively, one could actively counter leakage from the ocean or geological reservoirs by re-sequestering CO2 to stabilize climate at some desired level. But it would be hard to gauge the global leakage rate to be matched by re-sequestration. Furthermore, re-sequestration would have to be carried out over many thousands of years, a burden for future society in line with that of long term management of nuclear waste. "CO2 sequestration has many potential advantages over other forms of climate geoengineering. It makes good sense to modify the Earth's radiation balance by putting carbon back in where it came from. Atmospheric CO2 is long-lived and evenly-distributed globally making it possible to manage it in a long-term, controlled way with less chance for unpleasant climate surprises. However, one should not underestimate potential short and long-term problems with leakage from underground reservoirs. Carbon in light form will seek its way out of the ground or seabed. The present situation in the Gulf of Mexico is a poignant reminder of that", says Gary Shaffer. Professor Shaffer concludes that "the dangers of carbon sequestration are real and the development of this technique should not be used as an argument for continued high fossil fuel emissions. On the contrary, we should greatly limit CO2 emissions in our time to reduce the need for massive carbon sequestration and thus reduce unwanted consequences and burdens over many future generations from the leakage of sequestered CO2."
Our current model of cosmology—the origin and structure of the whole Universe—has survived another major test, with the release of the first 15 months of data from the Planck mission. Planck is a European Space Agency mission, designed to study the cosmic microwave background (CMB), which preserves information about the conditions that persisted immediately after the Big Bang. Combined with results from prior experiments, Planck has revealed a Universe a little older than previously thought, and with a slightly different balance of ingredients. Although there were no major surprises, some of its data provided stronger hints about inflation, a popular model that explains why the modern Universe looks the way it does. Other measurements ruled out extra neutrinos, provided even stronger evidence for the existence (though not the identity) of dark matter, and indicated that there's a bit less dark energy than previous measurements had suggested. But amid these incremental changes, there was a bit of a surprise: despite the best hopes of researchers, Planck data does not rule out the existence of anomalous temperature fluctuations at large scales. These may hint at either new physics that influenced the Universe's expansion, or previously unknown foreground sources that alter the CMB. Planck is a phenomenally sensitive instrument, kept at a 0.1° C above absolute zero by the use of liquid helium. By placing it at a stable point beyond Earth's orbit, the probe has a nearly uninterrupted view of the whole sky (this is better than Earth orbit, where it would experience day-night cycles and blockage of much of the sky by Earth's bulk). Since its launch in 2009, Planck has mapped the entire sky in microwave and submillimeter light, creating a 5 million pixel image of the temperature fluctuations from when the Universe was very young. That image helps tell us the Universe's age. Analysis of Planck data showed a slightly slower cosmic expansion rate, which means it took a bit longer to get to its current state. This nudges the age of the Universe upward to 13.81 billion years (with a margin of error of 50 million years either way). This is a marginal increase over the 13.77 billion year estimate, provided by the WMAP mission in combination with other observations. Tiny fluctuations have big meanings After the Big Bang, the cosmos was an opaque plasma, with too much energy to allow electrons and protons to form stable atoms. As it expanded, the Universe cooled, with stable atoms forming around 380,000 years after the Big Bang in an event known as recombination. This act both turned the Universe transparent and released photons, many of which have traveled uninterrupted into the modern era. While these photons were in the ultraviolet range at the time of recombination, the expansion of the Universe cooled the photons as well, so today they lie in the microwave portion of the spectrum. For this reason, the light is known as the cosmic microwave background. Planck's mission is to record these photons, which tell us about fluctuations in temperature at the earliest times in the Universe's history. These fluctuations exist at many scales; their physical size on the sky and temperature variation reveal the composition and structure of the Universe. Together, these fluctuations are known as the power spectrum. The largest fluctuations are the result of the total energy content of the Universe—dark energy, dark matter, ordinary matter, light, and anything else. Smaller fluctuations are due to matter alone, and they reveal the relative amounts of ordinary compared to dark matter and how that matter clumps together. By comparing theoretical models to the real CMB, cosmologists determined that dark energy—the mysterious substance driving cosmic acceleration—comprises 68.3 percent of the energy content of the Universe, down slightly from earlier estimates of 72.8 percent. Similarly, dark matter's contribution was boosted from 22.7 percent to 26.8 percent, while ordinary matter's share went from 4.5 percent to 4.9 percent. These adjustments largely came from an increase in the trustworthiness of power spectrum at smaller scales, where the effect of dark matter became more important. Comparing the earlier data on the third peak of the power spectrum to the Planck data leaves no doubt about the existence of dark matter (not that there was much prior to that). The fluctuations at even smaller scales agree with surveys of galaxies that measure the effect of sound waves in the early Universe, known as baryon acoustic oscillations. The weird side of the CMB One of the major challenges for any CMB measurement is confusion from the foreground. The Milky Way and other sources emit light at some of the same wavelengths as the CMB, so these effects need to be subtracted before a full CMB analysis can be performed. However, even with these foregrounds gone, both the Planck and earlier WMAP data still showed an anomalous set of fluctuations on very large scales (meaning they take up large areas of the total sky). In this case, one part of the sky seems warmer than the rest but contains an unusual "cold spot." To put it mildly, these anomalies are not well understood. Planck researcher George Efstathiou even suggested in the announcement press conference that they could be hints of an earlier stage of the Universe preceding the Big Bang. Other more prosaic explanations are also possible, including foreground microwave sources from objects that aren't known and haven't been predicted. Earlier cosmology data hinted that a fourth species of neutrino could exist (in addition to the known electron, mu, and tau neutrino species), but those hints were ambiguous. The new Planck results ruled that idea out, with the most likely number of neutrino species standing at 3. Additionally, Planck placed an upper bound on the sum of all three neutrino masses to be 0.85 eV, or about 0.0002 percent of the mass of an electron. One final piece from the power spectrum, known as the spectral index, indicates how fluctuations depend on size. Models for inflation predict a number slightly smaller than 1 for the spectral index; Planck data shows a value of about 0.96, with errors small enough so they don't overlap with 1. While it's too soon to say that this is a verification of inflation, it's a strong hint in that direction. The true tests of inflation—and of Planck's full prowess—will be revealed with the release of the polarization data, currently slated for early 2014. The polarization of different regions of the CMB may record a direct indication of the Universe's rapid expansion (called inflation) in its earliest moments. Planck's supply of liquid helium will be exhausted shortly after that, bringing the scientific mission to an end. But the data it has and will provide will keep cosmologists busy for a while. The full list of Planck papers may be found at the ESA site; all will be published by Astronomy and Astrophysics.
Also found in: Wikipedia. The currency of the Province of Canada prior to 1858. Initially, the pound was based on the Spanish dollar, making it worth somewhat less than the British pound. In 1853, Canada adopted the gold standard as part of a larger policy to encourage trade with the United States without alienating the United Kingdom. Like the British pound at the time, the Canadian pound was divided into 20 shillings or 240 pence.
This website aims to support school teachers in bringing a global dimension to their teaching by providing access to teaching resources, case studies and background information. By ‘global dimension’, we mean (very broadly) ‘exploring the world’s interconnections’. With a global dimension to their education, learners have a chance to engage with complex global issues and explore the links between their own lives and people, places and issues throughout the world. Education plays a vital role in helping children and young people recognise their responsibilities as citizens of the global community. It equips them with the skills required to make informed decisions and take responsible actions. By including the global dimension in teaching, links can easily be made between local and global issues, and young people are given the opportunity to: - critically examine their own values and attitudes - appreciate the similarities between people everywhere, and learn to value diversity - understand the global context of their local lives - develop skills that will enable them to combat injustice, prejudice and discrimination. Such knowledge, skills and understanding enable young people to make informed decisions about how they can play an active role in their local and global community.
5. In problem 2, assume that there is no point inside the circle where three of the line meet. How many points of intersection are there inside the circle? The picture from problem 2, will not work in this problem, because there are several point where more than two lines intersect, and this will throw off our theoretical count. We will need to adjust the points somewhat so that there is no point inside the circle where more than two lines intersect. We see in the figure above that it is possible to arrange 8 points on a circle so that there is no point inside the circle where more than two of the lines meet. We also see that there are quite a few points of intersection inside the circle for these lines. While it is possible to count them, it would probably be better to solve enough of the simpler problems to be able to find a pattern which would work in general and enable us to solve this problem. If there are 1, 2, or 3 points on the circle there are no points of intersection inside the circle. The first time we actually get a point of intersection inside the circle is with 4 points. It gets a little more interesting with 5 There are 5 points of intersection. there are 15 points of intersection. With 6 points, we need to take a little bit of care to make sure that there is no point where more than two lines meet. At this point, the figures are getting more and more complicated, so let's see if we can deduce the pattern at this point. We can find these numbers in Pascal's triangle These are the number of 4 element subsets of a given set. The next number in the sequence is 35 which should be the number of points of intersection inside the circle if there are 7 points on the circle. you can count that there are 35 points of intersection inside, and in our problem, there are 70 points inside the circle. The reason that this procedure works is because if you have a point inside a circle where 2 lines intersect, each line is determined by 2 points on the circle, so if you have two lines, they will be determined by 4 points on the circle. This sets up a one to one correspondence between points inside the circle and 4 element subsets of the set of points on the circle.
Plant Disorders: Leaf Scorch Leaf scorch is a physiological disorder of plants. It can affect most plants if the weather conditions are favorable. Extreme temperatures, heavy winds, periods of drought, and low soil moisture all contribute to leaf scorch. Scorching develops when water evaporates from a plant’s leaf surfaces, and is unable to be replenished through the root system. As a result, the leaf tissue becomes scorched, eventually turning necrotic. Plants that suffer from extreme leaf scorch may be defoliated, with many experiencing a decline in plant vigor. Distribution & Habitat Leaf scorch occurs globally, wherever susceptible plants are present. Leaf scorch impacts a multitude of plants. Plants that are prone to leaf scorch include alpine currant, ash, beech, birch, flowering dogwood, horse chestnut, Japanese maple, Norway maple, sugar maple, linden, and white pine. Evergreens are also commonly affected by leaf scorch. The most frequently affected are arbovitae, azalea, fir, laurel, Japanese andromeda, hemlock, pine, rhododendron, southern magnolia, spruce, and yew. Young trees, diseased trees, or trees that have been infested with insects are more susceptible to leaf scorch. How Does Leaf Scorch Occur? Leaf scorch occurs when adverse factors combine to weaken a plant. Periods of extreme heat, exposure to drying winds, and drought conditions are the primary causes of leaf scorch. Damage to a plant’s root system can also result in leaf scorch. Roots may be damaged in a variety of ways. They can incur mechanical and frost injuries; soil compaction may restrict their growth; they may be smothered by water during rainstorms; they may develop nutrient deficiencies; and they can erode when exposed to high concentrations of de-icing salt, fertilizer, or chemicals. Disease pathogens and insects can infiltrate plants. Many are capable of disrupting a plant’s vascular system, which can contribute to the appearance of leaf scorch. Wilt diseases, such as pine wilt, oak wilt, and verticillium wilt create the conditions necessary for leaf scorch. The damage caused by leaf scorch may sometimes be indicative of a plant’s intolerance for a particular environment or exposure. Symptoms of Leaf Scorch Leaf scorch symptoms differ between plant species. On many deciduous plants, symptoms of leaf scorch generally appear between July and August. Leaves that have been scorched become discolored. Initially, a subtle yellowing between the leaf veins and along the leaf margins occurs, followed by a browning of the leaf tips. Eventually, the yellowing progresses, with tissue rapidly becoming necrotic at the leaf margins, and between the leaf veins. Some leaves may become entirely necrotic, without exhibiting any previous yellowing. Leaves that have been severely scorched may curl and wither. Scorched leaves are usually most abundant on the side of the plant exposed to direct sunlight, and prevailing winds. Leaf scorch may be confined to a single branch, or uniformly affect an entire plant. Winter leaf scorch impacts many broad-leaved and narrow-leaved evergreens. Scorch injury on evergreens generally results from persistent exposure to heavy winds. On broad-leaved evergreens, such as azalea, euonymus, and holly, two long brown areas will form parallel to the main leaf vein, and enlarge as the plant becomes increasingly stressed. On narrow-leaved evergreens, such as arbovitae, fir, hemlock, pine, spruce, and yew, a browning develops at the needle tip, and progresses inward. As the plant declines, more needles will turn brown. Eventually, all of the needles may become necrotic. - While leaf scorch can defoliate plants, it seldom kills them altogether. To maintain plant vigor, and reduce the incidence of leaf scorch, use sound cultural practices. Ensure that plants are sufficiently watered, especially during periods of extended drought. A thorough drenching of the soil is most effective. - Apply a layer of organic mulch around the base of plants in early spring. Proper mulching will help to improve the soil quality, conserve soil moisture, and moderate the soil temperature. - Test the soil around scorched plants to determine if there are any nutrient imbalances. - Apply fertilizers in early spring or late fall, following leaf drop, to minimize the potential of root injury. Avoid excessive fertilizer applications during summer, when the soil is dry. Do not use fertilizers that contain an abundance of nitrogen. - Prune dead, diseased, and encroaching branches to promote air circulation throughout the crown, and reduce the amount of foliage the root system must support. - If de-icing salts or fertilizer have been used around scorched plants, leach the soil with a slow trickle of water for twenty four hours. - Protective screens can be erected around plants not suited to a particular climate or location. Screens can reduce a plant’s exposure to the wind. If you have any questions about leaf scorch, or you are interested in one of our tree services, contact us at 978-468-6688, or Sales@IronTreeService.com. We are available 24/7, and can accommodate any schedule. All estimates are free of charge. We look forward to hearing from you. Photo courtesy of Richard Buckley, Rutgers PDL
Western long-beaked echidna \|Western long-beaked echidna\| The western long-beaked echidna (Zaglossus bruijni) is one of the echidnas which live in New Guinea. Fossils of this species have also been found in Australia. It is one of the four living echidnas, three of which are species of Zaglossus. This echidna lives from 1300m to 4000m above sea level. It lives in alpine meadow and humid forests in the mountains. Unlike the short-beaked echidna which eats ants and termites, the long-beaked species eats earthworms. It is also larger that the short-beaked species. It can be told apart from the other Zaglossus species by the number of claws on the front and back feet. It has three (rarely four) claws. It is an endangered species. Its population has been reduced by habitat habitat loss and hunting. The long-beaked Echidna is good to eat. Although hunting the species has been banned by the Indonesian and Papua New Guinea governments, traditional hunting is permitted. In February of 2006, an expedition led by Conservation International found a population of them in what they described as a "lost world" of wildlife in the Foja Mountains of Papua Province, Indonesia. References[change \| change source] - Augee M and Gooden B. 1993. Echidnas of Australia and New Guinea. Australian National History Press ISBN 978-0-86840-046-4 - Flannery T.F. and Groves C.P. 1998 A revision of the genus Zaglossus (Monotremata, Tachyglossidae), with description of new species and subspecies. Mammalia, 62(3): 367-396 \|Wikimedia Commons has media related to Zaglossus bruijni.\|
Child Safety: School Bus Still Best Experts weigh the merits of changing safety standards of school buses. Bus Stop Safety More kids die when they're hit by a school bus than when riding in school buses, according to the NHTSA. It could happen like this. A second-grader clambers down from the school bus and starts for home, when a sheet of paper, a very important handout from his teacher, slips out of the binder he carries. Caught by the wind, it sails under the bus. He dashes after it. The brake disengages. The engine revs. The wheels turn. Again, relative to how many millions of kids are let off at bus stops every afternoon, very few fatal accidents of this sort actually happen. Children routinely get lessons at school about the danger of getting in the way of buses, among other bus stop safety rules. Various mirrors help bus drivers see all around the bus, and gates that swing out on the exit side remind children not to cross too close in front of the bus. Drivers are also trained to follow procedures intended to prevent them from accidentally running over their passengers. Heedless motorists pose a risk, too. Studies have shown that in a single day, hundreds of thousands of cars will pass stopped school buses illegally, and that's not because a stopped bus is inconspicuous. "It's 40 feet long, it's 11 feet high, it's yellow, it's got flashing red and yellow lights on it, it's got a stop arm that comes out; it's almost inconceivable that people don't see it," Martin says. No one should be satisfied until the rate is zero, but children are rarely killed by other vehicles at bus stops. The average is five deaths each year in the U.S. Safety Tips for Kids Children should learn these basic safety rules: - Stay at least 10 feet away from a bus until it's time to get on. Then wait your turn and get on one at a time. - Before stepping off the bus, look to be sure a car isn't coming. - Don't linger or play near the bus after you leave it. - Take 5 giant steps out in front of the bus before you cross the street. Be sure the driver sees you and signals that it's OK to cross in front of the bus. - Before crossing the street, make sure all cars on the road are stopped.
According to the Hawaii State Office of Hawaiian Affairs, which administers programs benefiting Hawaiians, "Hawaiian" or "Native Hawaiian" (capitalized) refers to: In 1984, 61% of Native Hawaiians had less than 50% Hawaiian blood. In the 1990 census two thirds of all Native Hawaiians lived in Hawaii and the remaining 1/3 lived on the mainland. Nearly half of the mainland Native Hawaiians lived in California. There were an estimated 300,000 Native Hawaiians in 1778. In 1984, according to the Office of Hawaiian Affairs, only 8,244 pure blood Native Hawaiians were thought to remain out of some 208,476 Native Hawaiians. 62% of the pure-blooded Native Hawaiians lived on the island of Oahu. In the first century after contact with Europeans, the Native Hawaiian population declined over 80%, mainly from new diseases. From an estimated 300,000 when Europeans arrived, the Native Hawaiian population fell to a steady low of around 40,000 between 1890 and 1920. The population began to increase in the 1920s, although the number of pure-blooded Native Hawaiians has been in constant decline though 1990. The word "Hawaiian" could also be used for any resident of the State of Hawaii, regardless of ancestry, but such use is discouraged within Hawaii. People living in Hawai'i collectively refer to themselves as "locals," "Islanders", or "Island people," among other terms, and reserve "Hawaiian" to describe people actually of Native Hawaiian descent.
What is immunity. Cellular and humoral immunity Most modern people have heard about the existence of the body's immune system and that it prevents the emergence of all kinds of pathologies caused by external and internal factors. How this system works, and on what its protective functions depend, not everyone can answer. Many will be surprised to learn that we have not one but two immunities - cellular and humoral. Immunity, in addition, can be active and passive, innate and acquired, specific and nonspecific. Consider what the difference between them is. The concept of immunity Incredibly, even in the simplest organisms, for example, pre-nuclear prokaryotes and eukaryotes, there is a protective system that allows them to avoid infection with viruses. To this end, they produce special enzymes and toxins. This is also a kind of immunity in the most elementary form. In more highly organized organisms, the protective system has a multi-level organization. It performs the function of protecting all organs and parts of the body of an individual from With the name of the given system of protection all is simple - cellular, means, it is somehow connected with cells of an organism. It involves an immune response without the involvement of antibodies and the complement system. The main "executors" for neutralizing foreign agents that have penetrated the body, in cellular immunity are T-lymphocytes, which produce receptors that are fixed on cell membranes. They begin to act by direct contact with a foreign stimulus. Carrying out a comparison of cellular and humoral immunity, it should be noted that the former "specializes" on viruses, fungi, tumors of various etiologies, various microorganisms penetrated into the cell. He also neutralizes microbes that survived in phagocytes. The second prefers to deal with bacteria and other pathogenic agents located in the blood or lymphatic channels. The principles of their work differ slightly. Cellular immunity activates phagocytes, T-lymphocytes, NK cells( natural killers) and secretes cytokines. These are small peptide molecules, which, appearing on the membrane of cell A, interact with the receptors of cell B. So they transmit a signal of danger. It triggers response defense responses in neighboring cells. As noted above, the main difference between cellular and humoral immunity is in the location of the objects of their action. Of course, the mechanisms by which protection from malicious agents is performed also has its own specific features. On the humoral immunity, in general, "work" B-lymphocytes. In adults, they are produced exclusively in the bone marrow, and in embryos additionally in the liver. Humoral, this type of defense was called from the word "humor", which in Latin means "bed".B-lymphocytes are able to produce antibodies that separate from the cell surface and move freely through the lymphatic or bloodstream. Activating B-lymphocytes( induce to action) are foreign agents or T-cells. This is the link between the principle of interaction between immunity of cellular and humoral immunity. More about T-lymphocytes These cells are a special kind of lymphocytes produced in the thymus. People are called the thymus gland, located in the chest just below the thyroid. The first letter of this important organ is used in the name of lymphocytes. In the bone marrow, progenitors of T-lymphocytes are produced. In the thymus, their final differentiation( formation) takes place, as a result of which they acquire cellular receptors and markers. There are several types of T-lymphocytes: - T-helpers. The name is derived from the English word help, which means "help.""Helper" in English is an assistant. Such cells themselves do not destroy foreign agents, but activate the production of killer cells, monocytes, cytokines. - T-killers. These are "innate" killers, whose purpose is to destroy the cells of their own organism, in which the alien agent settled. These "killers" there are many variations. Each such cell "sees" the on only one type of pathogen. That is, T-killers, reacting, for example, to streptococcus, will ignore salmonella. They also "will not notice" an alien "pest" that has penetrated the human body, but while free circulating in its liquid media. The peculiarities of the action of T-killers make it clear why cellular immunity differs from humoral immunity, which works in a different way. - γδ T-lymphocytes. They are formed very little, in comparison with other T-cells. They are configured to recognize lipid agents. - T-suppressors. Their role is to provide an immune response of such duration and strength that are required in each specific case. More about B-cells of These cells were first detected in birds in their organ, which is written in Latin as Bursa fabricii. The first letter was added to the name of lymphocytes. They are born from stem cells located in the red bone marrow. From there they come immature. The final differentiation ends in the spleen and in the lymph nodes, where two types of cells are obtained: - Plasmatic. These are B-lymphocytes, or plasmocytes, which are the main "factories" for the production of antibodies. For 1 second each plasma cell produces thousands of protein molecules( immunoglobulins), oriented to any one type of microbe. Therefore, the immune system is forced to differentiate many varieties of plasma B-lymphocytes in order to fight various pathogenic agents. - Memory cells. These are small lymphocytes that live much longer than other forms. They "remember" the antigen against which they already protected the body. When re-infected with such an agent, they very quickly activate the immune response, producing a huge number of antibodies. There are also memory cells in T-lymphocytes. In this immunity, cellular and humoral immunity are similar. Moreover, these two types of protection against foreign aggressors act together, since B-lymphocytes of memory are activated with the participation of T-cells. The ability to remember pathological agents formed the basis for vaccination, which creates acquired immunity in the body. This ability also acts after the person has suffered diseases that are resistant to immunity( chickenpox, scarlet fever, smallpox). Other immunity factors Each type of body defense against foreign agents has its own, say, performers who seek to destroy pathogenic formation or at least to prevent its penetration into the system. Let's repeat, that immunity on one of classifications happens: 2. Purchased. It is active( appears after vaccinations and some diseases) and passive( occurs as a result of the transfer of antibodies to the infant from the mother or the introduction of serum with the ready antibodies). According to another classification, the immunity can be: - Natural( includes 1 and 2 types of protection from the previous classification). - Artificial( this is the same acquired immunity, which appeared after inoculations or some sera). Congenital type of protection has the following factors: - Mechanical( skin, mucous, lymph nodes). - Chemical( sweat, secrets of the sebaceous glands, lactic acid). - Self-cleaning( tears, peeling, sneezing and others). - Anti-adhesive( mucin). - Mobilizable( inflammation of the infected site, immune response). The acquired type of protection has only cellular and humoral immunity factors. Let us consider them in more detail. The effect of this type of immunity is provided by the following factors: - Compliment system. This term denotes a group of whey proteins, constantly present in the body of a healthy person. While there is no introduction of a foreign agent, the proteins are inactive. Once the pathogen penetrates into the inner environment, the compliment system is instantaneously activated. This happens on the basis of the "domino" principle - one protein that has detected, for example, a microbe, informs the other nearest, the next one, and so on. As a result, complement proteins break down, releasing substances that perforate membranes of foreign living systems, leasing their cells, initiating an inflammation reaction. - Soluble receptors( needed for the destruction of pathogens). - Antimicrobial peptides( lysozyme). - Interferons. These are specific proteins that can protect a cell infected by one agent from hitting another. They produce interferon lymphocytes, T-leukocytes and fibroblasts. Please note that this term has a slightly different definition than cellular immunity, the main factors of which are T-lymphocytes. They destroy the pathogen and simultaneously the cell that it has infected. Also in the immune system is the concept of cellular factors, which include neutrophils and macrophages. Their main role is to absorb the problem cell and digest it( eat).As you can see, they are engaged in the same thing as T-lymphocytes( killers), but they have their own characteristics. Neutrophils are indivisible cells containing a large number of granules. They contain antibiotic proteins. Important properties of neutrophils - a short life and the ability to chemotaxis, that is, the movement to the site of the introduction of the microbe. Macrophages are cells that can absorb and process rather large foreign particles. In addition, their role is to transfer information about the pathogenic agent to other protective systems and to stimulate their activity. As you can see, types of immunity cellular and humoral, performing each of its functions, predetermined by nature, act together, thus ensuring maximum protection of the organism. Mechanism of cellular immunity work To understand how it works, you need to return to T cells. In the thymus, they pass, so-called, selection, that is, acquire receptors that are able to recognize this or that pathogenic agent. Without this, they will not be able to perform their protective functions. The first stage is called β-selection. Its process is very complex and deserves a separate consideration. In our article, we note only that during β-selection, most T-lymphocytes acquire pre-TRK receptors. Those cells that can not form them die. The second stage is called positive selection. T cells that have pre-TPA receptors are not yet capable of protecting against pathogenic agents, since they can not bind to molecules from the histocompatibility complex. To do this, they need to acquire other receptors - CD8 and CD4.During complex transformations, some cells get the opportunity to interact with the MHC proteins. The rest perish. The third stage is called negative selection. During this process, cells that have passed through the second stage move to the thymus boundary, where some of them come into contact with their own antigens. Such cells also die. This prevents autoimmune diseases in humans. The remaining T cells begin to work to protect the body. In the inactive state they are sent to the place of their vital activity. When foreign agent penetrates into the body, they react to it, recognize, activate and begin to share, forming the T helper, T-killers and other factors described above. Principle of humoral immunity If the microbe has successfully passed all the mechanical barriers of protection, it has not died from the action of chemical and antiadhesive factors, and has penetrated the body, humoral immunity factors are being taken for granted. T-cells "do not see" the agent while he is in a free state. But activated antigen presenting cells( macrophages and others) capture the pathogen and rush with it into the lymph nodes. The T-lymphocytes found there are able to recognize pathogens, since they have corresponding receptors for this. Once the "identification" has occurred, the T cells begin to produce "helpers", "killers" and activate B-lymphocytes. Those, in turn, begin to develop antibodies. All these actions once again confirm the close interaction of cellular and humoral immunities. Their mechanisms for fighting the alien agent are somewhat different, but are aimed at the complete destruction of the pathogen. We examined how the body is protected against various harmful agents. On the guard of our life are cellular and humoral immunities. Their general characteristics consist in such features: - Have memory cells. - Act against the same agents( bacteria, viruses, fungi). - In its structure have receptors, through which the recognition of pathogens occurs. - Before starting work on protection, a long stage of maturation takes place. The main difference is that cellular immunity destroys only those agents that have penetrated into cells, and the humoral immunity can work at any distance from the lymphocytes, since the antibodies they produce to the cell membranes are not attached.
This is a drawing of the transition from the atmosphere to the interior. Click on image for full size The Structure of Saturn's Interior There is no surface to the giant planets, only a gradual change from the atmosphere, as shown in this drawing. The gases which Saturn is mostly made of change to liquid inside Saturn, but the change is very gradual. Therefore the giant planets do not have strict layers, as the earth-like planets do. The liquid sections of Saturn form by far the largest portions of the planet, and penetrate very deep into the planet. The first liquid layer inside Saturn, immediately under the atmosphere, is the liquid hydrogen layer. Under the liquid hydrogen layer is a liquid metallic hydrogen layer. At the far interior is the core of Saturn. Shop Windows to the Universe Science Store! Our online store on science education, ranging from evolution , classroom research , and the need for science and math literacy You might also be interested in: The first liquid layer inside Saturn, right under the atmosphere, is the liquid hydrogen layer. The hydrogen atmosphere becomes thicker and thicker, like a dense fog, with more and more liquid droplets,...more The Giant planets do not have the same layered structure that the terrestrial planets do. Their evolution was quite different than that of the terrestrial planets, and they have less solid material. Saturn's...more There is no surface to the giant planets, only a gradual change from the atmosphere, as shown in this drawing. The gases which Saturn is mostly made of change to liquid inside Saturn, but the change is...more The most important motions in the atmosphere are winds. The major winds in Saturn's atmosphere are the zonal winds which are made of zones and belts. Zones are high pressure systems and belts are low pressure...more The striped cloud bands on Saturn, like Jupiter, are divided into belts and zones. In a belt, the wind flows very strongly in one direction only. In a zone, the wind flows very strongly in exactly the...more The position of the planets in the solar nebula greatly affected their 1. size and 2. composition. This is because of the effect of how cold it was in the nebula. 1. The nebula was a lot warmer close to...more As shown in this picture, while they were forming in the solar nebula, the nucleii of the planets-to-be (called protoplanets) drew material to themselves from the cloud of gas and dust around them. The...more
The measure of the angle of elevation from point A is θ. In right triangle APQ, tan θ = θ = 33°41′. Correct answer : (3) The angle of elevation of the top of a hill from the foot of a tower is 62° and the angle of elevation of the top of the tower from the foot of the hill is 28°. If the tower is 40 ft high, then find the height of the hill. Draw the diagram. Let represent the height of the hill and let represent the distance between the hill and the tower. In right triangle QPA, tan 28° = = = 75 In right triangle PAB, tan 62° = = 75 tan 62° = 141 The height of the hill is 141 ft. Correct answer : (1) Tom and Sam are on either side of a tower of height meters.They measure the angle of elevation of the top of the tower as and respectively. Find the distance through which Tom and Sam are seperated. [Given = 160, = 50° and = 35°.] Height of the pole is AB = = 160 meters, C and D are the positions of Tom and Sam as shown. [Draw the diagram for the given data.] ACB = = 50° and ADB = = 35° [Write the angles of elevation of A from Tom, Sam.] In the right triangle ADB, tan = tan 35° = [tan = .] BD = » 228.571 meters [Substitute the value of tan 35° and find BD.] In the right triangle ABC, tan = tan 50° = [tan = .] BC = » 134.340 meters [Substitute the value of tan 50° and find BC.] CD = CB + BD = 228.571 +134.340 » 363 m [Use CD = CB + BD to find CD.] So, the distance between Tom and Sam is 363 m. Correct answer : (4) The angle of depression of the top of a tower of height meters from the top of another tower of height H meters is 25°. Find the horizontal distance between the two towers when = 93 and H = 125. Height of the first tower is CD = = 93 meters, height of the second tower is AB = H = 125 meters as shown [Draw the diagram for the given data.] Let the distance between the two towers, BC = ED = meters and the difference between the heights of the two towers, AE = meters The angle of depression of D from A is = 25° [Write the angle of depression of D from A.] ADE = = 25° [ ADE = as ADE, are alternate angles.] In the right triangle ADE, tan ADE = tan 25° = = and hence = 0.46 [Substitute the value of tan 25° and find in terms of .] = AE = AB - BE = 125 - 93 = 32 meters [From the figure AE = AB - BE = .]
Child Trauma and Young Children Childhood trauma has been characterized as an urgent public health problem and the largest single preventable cause of long-term mental illness in children. Child traumatic stress occurs when children are exposed to traumatic events or situations that overwhelm their ability to cope, including situations where the child’s relationship with his/her primary caregiver is weakened due to the traumatic event. Repeat exposure to trauma can affect a child’s brain development and increase the risk of low academic performance, engagement in high-risk behaviors, and difficulties in family and peer relationships. Childhood trauma can stem from child abuse and neglect; a tragic separation between a child and his/her primary caregiver due to violence or incarceration; witnessing violence between adults who care for children; neighborhood violence; and other events that cause extraordinary stress for a child. Young children are disproportionately the victims of violence and neglect and are frequent witnesses to violence between the adults who care for them. Child-Parent Psychotherapy is a highly effective treatment method that reduces the negative impact of various forms of trauma on young children by restoring the child-parent relationship, and the child’s mental health and developmental progression that have been damaged by the traumatic experience. Child-Parent Psychotherapy is an evidenced-based model for children that is developmentally and culturally informed to meet the needs of all families. It also addresses unresolved traumatic events the primary caregiver may have experienced that interfere with his or her ability to parent effectively. Research demonstrates that Child-Parent Psychotherapy is one of the best ways to address child trauma, strengthen the child-parent relationship, and improve child outcomes including increased IQ scores and school readiness. This intervention has been shown in randomized clinical trials to improve the mental health of both primary caregivers and their children, and to decrease levels of depression and anxiety in women. The Child Trauma Research Project (CTRP) developed and implements this model specifically designed for traumatized parents and their children in the first five years of life. Child-Parent Psychotherapy is currently being disseminated nationally through CTRP, the National Child Traumatic Stress Network and the Safe Start Initiative.
Creating A Caring Classroom Positive learning starts with learning the students names quickly and getting to know students as individuals. This makes students feel important. For example in elementary schools they have lessons on topics like friendships. In middle or high school teachers focus on teamwork skills, these are some ways to create a positive learning environment. Respect is one of the most important elements in a classroom. Teachers may not just expect respect from students but show them respect also. Respect in the classroom often is getting to know each other, particularly with those who do not normally interact. Teachers will have group activities to give them an opportunity to work together. For example teacher will number students off and which number they get that is there group. This is a way of mixing everyone up so they can work with different people. Student feedback is very valuable, students feel their opinions are important. Also helps them develop a sense of responsibility for the classroom. They can share ideas on useful suggestions, teachers build class bonds. Teachers will add free response answers on a test and ask for feedback on the class assignment or project. Class identity is a feeling of cohesiveness that sports teams have, like a team or family bond. These connections grow over time and they can in the classroom also with the teachers encouragement. Classroom routines, traditions, and whole-class experiences help strengthen these bonds. Teachers can make it a rule that everyday when the students walks in they have to speak to their classmates, making everyone feel welcomed like a family.
Pipe piling is a structural building material used to support and stabilize a building’s foundation. When the soil below a building is loosely packed, it may not offer enough strength to keep the building stable over time. A pipe piling can be used to distribute the weight of the building deeper into the earth, where the soil is often more tightly packed. Pipe piles are also used to support exceptionally large or heavy buildings, where even standard soil cannot offer adequate support. Finally, a pipe piling may be required when the land area is too small to accommodate spread footers or foundations, forcing buildings to dig deeper to achieve sufficient ground stability. Most forms of pipe piling consist of heavy-duty steel pipes, which are often galvanized with zinc to increase moisture and corrosion-resistance. When only a standard level of support is required, an open-ended pipe is often used. If additional support is required, these pipes may be capped with steel plates to form close-ended pilings. Installers can then fill the pipe with concrete and rebar to add extra strength and stability. Piles are driven into the ground using large machines known as pile drivers. These machines contain hydraulic systems which exert extremely high levels of force to drive the piles into the ground. By driving the piles directly into the soil without drilling holes first, the soil itself helps to support and stabilize the piles. As the pile is driven underground, the soil is displaced, which increases friction and pressure around the pile to hold it in place. Engineers and installers determine the placement for each pipe pile based on the building loads at various locations. A very heavy load, such as a piece of industrial equipment, may need to sit directly over a pile to ensure adequate support. When building loads are evenly distributed, installers may use a concrete pile cap to support the building. This allows the pipe pilings to be equally spaced below the building, then connected together with the pile cap to act as a large foundation system. Each pipe piling must be carefully chosen based on building forces, soil conditions and local building codes. A geotechnical engineer can test the soil to determine whether piles are needed. The structural engineer then determines the size and material needed for each pipe piling, as well as the required depth. When a single pipe is not long enough to reach this depth, piles may be joined together using butt welds or splicing sleeves. (This article comes from wiseGEEK editor released) Driven sheet piles are thin interlocking steel sheets used to construct a continuous barrier in the ground. Interlock is typically achieved by clutching the edge of one pile into the previous pile. A wide range of sheet pile sections and profiles are available from many steel manufacturers. c sections have a weaker interlock than hot-rolled sections. In hard driving conditions this interlock might “unzip” or cause alignment problems which would require replacement of the sheet piles. Cold-rolled sections also are usually thinner than hot rolled and thus may be more prone to overstressing during driving. Sheet piled retaining walls are often restrained by use of internal propping, bracing, anchors or deadmen. It is often possible to extract and reuse sheet piles making this an economically attractive retaining wall system. One of the main applications for sheet piles is for temporary retaining walls or cofferdams used to allow permanent in ground construction to be undertaken. The durability of sheet piles can be extended with protective coatings. Driven sheet piles are often installed by vibrating hammers operated off leaders mounted on tracked base machines or suspended from crawler cranes. Diesel impact hammers and hydraulic press in machines can also be used to drive or push the piles into place. Sometimes water jetting or preboring is used to assist penetration through stiff or hard layers. (This article comes from PILING CONTRACTORS editor released) Most steel sheet piling is still designed using allowable stress design methods; thus, a factor of safety is usually specified that reduces the allowable stress in the pile from the yield stress. The allowable stress is thus Equation 2-1: σallow = Freduction σy - σallow = Allowable Stress of the Material - Freduction = Reduction factor of safety - σy = Yield Stress of the Material, psi or kPa With steel piling in pure bending (see below), there are two reduction factors used: For static loads, for permanent works the reduction factor is generally 0.65, or the allowable stress is 65% of the yield stress. For the grades listed above: ASTM A328: σallow = (0.65)(39) ≈ 25 ksi ASTM A572, ASTM A690: σallow = (0.65)(50) ≈ 32.5 ksi For earthquake loads, the reduction factor is generally (1.33)(0.65) ≈ 0.87, or the allowable stress is 87% of the yield stress. Using this increased value for earthquake loads presupposes a static analysis to insure that the static case is not in fact the governing case for a particular situation. For the grades listed above: ASTM A328: σallow = (0.87)(39) ≈ 34 ksi ASTM A572, ASTM A690: σallow = (0.87)(50) ≈ 43.5 ksi (This article comes from Pile Buck International editor released) Sheet piling is a type of deep foundation used in construction work. As opposed to shallow foundation, deep foundations like sheet piling provide a more structurally sound design for large buildings and heavy loads. Sheet Piling Design - Sheet piles are long interlocking structural sections. With a vertical interlocking system, sheet piles create continuous walls for construction projects. Sheet Piling Uses - Sheet piles create an extended barrier from soil or water for either permanent or temporary use. The steel sheets resist the lateral bending forces, strengthening the overall foundational structure. Temporary vs. Permanent - Sheet piles can temporarily create access and a safe working environment for construction sites. Sheet piles are helpful in the permanent design of a building to create a basis for other foundational components. (This article comes from eHow editor released) City of Espoo in Finland is investing significantly in infrastructure in various locations. Areas around Leppävaara neighborhood have seen a lot of new development in the recent history. Besides of all new development one of the ongoing project is to upgrade the pedestrian street and market square of older commercial area. Civil engineering company E.M. Pekkinen is completing the scheme that includes sheet piling, other piling works, ground improvement, relocating utilities and finally paving and landscaping. Most of the work is carried out in limited space with minimum disturbance to shops and other businesses along the pedestrian street. Excavations for utility works require temporary retaining walls. Installations of the sheet piles in these conditions and very close to building walls take both carefully chosen equipment and experienced personnel. E.M. Pekkinen is experienced piling and civil engineering provider. (This article comes from MOVAX editor released) If the soil behind a sheet pile wall is back filled in layers and subsequently compacted , the earth pressure on the wall at a certain depth below the surface of the back fill can exceed the active earth pressure due to self-weight in some circumstances. DIN 4085:2007 provides design suggestions for applying the compaction pressure depending on the type of compaction (rolling or vibration) and the magnitude of the earth pressure (active earth pressure or steady-state earth pressure). If the surface is subsequently loaded, e.g. by further layers of fill, the earth pressure due to compaction remains effective only to the extent that it exceeds the earth pressure due to addi-tional loads. From this it follows that in the majority of cases only the earth pressure due to compaction in the upper layers needs to be considered. In sheet pile walls with different water levels on either side, the excess hydrostatic pressure is included in the sheet piling calculation as a characteristic action. The excess hydrostatic pressure wu at depth z of the sheet pile wall is calculated from the difference in the hydrostatic pressures on the two sides. wu (z )= wr (z ) − wl (z )= hr (z ) · γw − hl (z ) · γw Excess hydrostatic pressure assumptions for a wall in stationary water If we neglect the flow around the sheet pile wall, e.g. if the sheet pile wall is embedded in an impermeable stratum, the result is an excess hydrostatic pressure with a triangular distribution in the region of the one-sided hydrostatic load and a constant load in the lower region down to the base of the sheet piling. Weldinginvolves fusing together two identical or very similar steels to form one homogenous component, and this is done by melting them together at their interface through liquefaction or plastic deformation. This can be carried out with or without the addition of another material. Arc welding is a very common method (manual metal-arc welding, shielded metal-arc welding). In this method an electric arc is generated between an electrode, which supplies the welding material, and the component. The suitability for welding depends not only on the material, but also on its shape, the dimensions and the fabrication conditions. Killed steels should generally be preferred. According to EAU 2004 section 184.108.40.206 (R 67), and taking into account general welding speci- fications, arc welding can be used for all the grades of steel used for sheet piles. The building authority approvals must be adhered to for high-strength steel grades S 390 GP and S 430 GP. In addition, the carbon equivalent CEV should not exceed the value for steel grade S 355 to DIN EN 10025 table 4 if welding is to be employed. Furthermore, EAU 2004 section 220.127.116.11 (R 67) recommends using fully killed steels of the J2 G3 or K2 G3 groups to DIN EN 10025 in special cases, e.g. where plastic deformation due to heavy driving is expected, at low temperatures, in three-dimensional stress conditions and when the loads are principally dynamic, because of the better resistance to embrittlement and ageing required. Welding electrodes conforming to DIN EN 499, DIN EN 756 and DIN EN 440 or the speci fication of the supplier should be selected. According to EAU 2004 section 18.104.22.168 (R 99), basic electrodes or filler materials with a high basicity should generally be used. The follow table provides general information about the selection of suitable electrodes according to DIN EN 499. The presence of groundwater in front of or behind the sheet pile wall has a direct effect on the earth pressure. In stationary water, the buoyancy force of the groundwater acting on the granular structure reduces the effective unit weight of the soil such that only its submerged unit weight γ is effective. The active and passive earth pressures are therefore reduced. If the groundwater flows around the sheet pile wall, then hydrodynamic pressures generate additional forces that act on the granular structure of the soil. The hydrodynamic pressure fs = i · γw increases the effective stresses on the side where the water flows downwards (normally the active earth pressure side) and reduces the effective stresses on the side where the water flows upwards (normally the passive earth pressure side). The exact calculation procedure is illustrated with an example in the follow picture. There, the intention was to illustrate the effect of the hydrodynamic pressure on the hydrostatic pressure, whereas here it is the effect on the active earth pressure. If the base of the sheet pile wall is not embedded in an impermeable stratum, groundwater can flow under the sheet piling structure. Proper planning and design of sheet pile walls located in groundwaterflows calls for a knowledge of the effects of the flowing groundwater. As the groundwaterflows from regions of high hydraulic head to regions with a lower head, the hydrodynamic pressure is directed downwards on the excess hydrostatic pressure side and upwards on the opposite side. This means that the hydrostatic pressure on the excess hydrostatic pressure side is lower and that on the opposite side higher than the hydrostatic pressure. The hydrodynamic pressure also acts on the granular structure of the soil: it increases the effective particle-to-particle stresses on the excess hydrostatic pressure side and decreases them on the opposite side. This means that the active earth pressure on the excess hydrostatic pressure side is increased, and the passive earth pressure on the opposite side is decreased. Taking into account the groundwater flows has a beneficial effect on the excess hydrostatic pressure and a detrimental effect on the passive earth pressure. Whether on the whole a more favourable or less favourable in fluence prevails, must be investigated in each individual case. Generally, there are three ways of considering the hydrostatic pressure on a wall in flowing groundwater: - Ignore the flow and assume the excess hydrostatic pressure according to section 4.2. - Perform calculations with the help of a flow net. - Perform calculations with the help of an approximation method assuming modified unit In the majority of cases it is sufficient to ignore the groundwater flow and assume the excess hydrostatic pressure according to section 4.2. If high excess hydrostatic pressures are present, then more accurate flow net calculations are advisable in the case of strati fied soils with different permeabilities. In addition, an accurate investigation of the flow conditions is necessary for verifying resistance to hydraulic ground failure, especially in the case of large water level differences and strata with low permeability near the surface on the passive earth pressure side.
The chemical formula for tin(IV) nitrate, also known as stannic nitrate, is Sn(NO3)4. It is synthesized by the reaction of 70 percent composition of nitric acid and tin.Continue Reading In chemistry, the two types of compounds are organic and inorganic. Organic compounds involve the formation of substances containing the element carbon while inorganic compounds are made up of two or more elements, other than carbon, that are chemically bonded together. Inorganic compounds are categorized into two: ionic compounds and molecular compounds. Ionic compounds comprise of a metal and a non-metal while molecular compounds are composed of two non-metals. Ionic compounds consist of a positively charged metallic ion, called a "cation," and a negatively charged non-metallic anion, which is referred to as an "anion." Some transition metals may exist in various ionic forms. Different ions of the same element are distinguished using a Roman numeral, which also indicates its oxidation state and charge. The element tin forms the Sn2+ and Sn4+ ions and are named tin(II) and tin(IV), respectively. The Latin equivalents of these two ions are stannous for tin(II) and stannic for tin(IV). When two or more atoms are covalently bonded, a polyatomic ion is formed. One of the most commonly occurring polyatomic anion is nitrate, with the chemical formula NO3-. The ionic compound tin(IV) nitrate consists of the stannic cation and the polyatomic nitrate anion.Learn more about Solutions & Mixtures
We learn by doing. Research shows that active learning is much better recalled, enjoyed and understood. Active methods require us to ‘make our own meaning’ , that is, develop our own conceptualisations of what we are learning. During this process we physically make neural connections in our brain, the process we call learning. Passive methods such as listening do not require us to make these neural connections or conceptualisations. Active methods also: - Give the learner feedback on their incomplete understandings and encourage them fix this, for example by helping each other. - Give the teacher feedback on which learners understand, and who needs help - Develop thinking skills such as analysis problem solving, and evaluation - Help learners to use their learning in realistic and useful ways, and see its importance and relevance - Are more fun! - Give the teacher a bit of a rest Good students may create meaning from passive methods, but weak students do not. Both types of student improve their learning enormously when they are required to use it. When active methods are compared with traditional methods in careful control group and experimental group comparisons, active methods produce much better achievement. This is true even though the control group (traditional didactic methods) has the same teaching time as the experimental (active learning) group. This is also true at every academic level. For more on this download Active Learning Works: the evidence - Download Active Learning works. - Download An introduction to constructivism. - See short videocasts by Geoff by clicking here then choosing ‘constructivism’ etc from the video clips menu. Why not experiment with some newish active methods? - Teaching without talking: Here are 25 ways of teaching without talking, that require students to make their own meanings. - Formative Teaching: These are relatively new active methods that provide the learner and the teacher with feedback. - Download this here. - Visual and Kinesthetic methods: All students benefit from variety, why not try these methods from one chapter of Teaching Today. - Download these here. How can I encourage my teaching team to use more active methods? - Try the Active Scheme of Work and the supported Experiments pages. - Play this game with your team - There are very many more methods to try in my book – ‘Teaching Today: a practical guide’ Geoff Petty, 5th Ed (2014) published by Oxford University Press, pages 133 to 343 deal specifically with teaching methods.
Reuse and recycle cardboard tubes to make spooky spiders, kooky caterpillars, wacky worms, and more. Treat your budding entomologist to this sculptural science activity that will allow him to research insects, arachnids, and other creepy crawlies. Turn this artful insect into a Halloween themed decoration, and display his unique buggy creations during a family holiday party or for trick-or-treaters to enjoy! The Cardboard Tube Critter activity will help your child to learn about the wonderful world of bugs as he also focuses on simple elements of art. He'll explore three dimensional form, color, texture, and pattern during this exciting art project. Encourage imaginative thought and creative problem solving skills as he designs and constructs his very own sculptural critter. What You Need: - Cardboard tube - Pom poms - Clear drying, non-toxic school glue - Tempera paint - Paint brushes - Pipe cleaners - Tissue paper - Modeling clay (optional) What You Do: - Research insects. Find a variety of non-fiction books to look at, or search the web for useful insect information. Make sure to view multiple pictures and photographs of bugs. Ask your child to talk about what he sees. How many legs does a spider have? What do a fly's eyes look like? What color is a grass hopper? - Decide on one bug to start with. Ask your child to think about the body parts that are needed. Is there a head, thorax, and abdomen? How many legs are there? Does this bug have wings, antennae, or other special features? - Have your child paint the cardboard tube a base color. For example, if he is creating a grasshopper the tube should be green, a spider might be brown or black, and a lady bug could be red. - After the paint has dried, he can begin adding details. Use a large pom pom and glue to create a head. Eyes can be made with sequins and glue. Use additional pom poms for other body parts. If he is making a bug such as a caterpillar, he may want to add multiple pom poms in a row. - Create antennas and legs by gluing on cut pieces of pipe cleaner. If you notice the pipe cleaner falling off, first attach a small piece of modeling clay to the tube with glue. Press the end of the pipe cleaner in to stabilize it. Alternatively, you can press the pipe cleaner through the tube or cut a small hole to fit. - Add wings and other features with cut tissue paper and glue. - Set aside to dry. Display as a creepy crawly Halloween decoration!
What causes a Tornado?The most common cause of a tornado is from a thunderstorm. Tornadoes form when warm, moist air or air from a thunderstorm meets cooler, dry air creating an unstable atmosphere. After creating an unstable atmosphere, changes in wind direction and wind speed creates a spinning effect near the earth's surface, eventually forming a tunnel of wind that rapidly grows and violently rotates along the earth's surface, destroying homes and uprooting trees that are in it's path. Where are they most likely to occur?Tornadoes are likely to occur anywhere in the world, but most tornadoes occur in "Tornado Alley," which stretches from Texas to Oklahoma, Nebraska, Kansas and into the Dakotas. The reasoning for "Tornado Alley," is because warm, moist air from the gulf of Mexico mixes with the cooler, dry air from the north creating dangerous tornadoes. Tornadoes can occur during any time of the year, but typically happen during the spring. What to do in case of a Tornado-If you find yourself in danger of a tornado, it's important that you take shelter to protect yourself. The safest place to be in the case of a tornado is in the basement of your house or the building that you are in. Do not go near the walls that face in the southern or western directions, this is generally the direction tornadoes move in. You should seek shelter under a stair case, inside a closet or under a heavy table. You should also use a heavy blanket or trash can for protection against debris. You may also seek shelter in the bathtub, in many homes that have been destroyed by tornadoes, the bathtub plumbing is the only thing left standing. This is because the plumbing is anchored into the ground. If you driving near a tornado, you should leave your car and find shelter inside, you should not keep driving, you may not know what you may encounter on the road. It's also important to realize that a car cannot outrun a tornado. 15 Facts About Tornadoes 1. In order for a vortex to be classified as a tornado, the violently rotating column of air must be in contact with both the cloud above and the ground below. 2. Though tornadoes do occur on other continents, North America’s geography makes it more vulnerable to them. Bradley Smull, an atmospheric scientist at the National Science Foundation, explained yesterday in a Washington Post online chat: “In particular, the proximity of a major north-south mountain range…and the Gulf of Mexico…all in a latitude range frequented by strong upper-level jetstreams amounts to something of a “perfect storm” for severe (supercell-type) thunderstorm formation.” 3. Tornadoes are rated on the Enhanced F (EF) Scale (the old scale was called the Fujita (F) Scale), which assigns a number (0 to 5) based on estimates of 3-second wind gusts and damage. There have been more than 50 F5/EF5 tornadoes recorded in the United States since 1950. 4. Rain, wind, lightning and/or hail may accompany a tornado, but none of them is a reliable predictor of an oncoming tornado. 5. A tornado can last from a few seconds to more than an hour. On average, they persist for about 10 minutes. 6. It is a myth that a tornado cannot pass over features like valleys, mountains, lakes and rivers. When it passes over a lake or river, a tornado becomes a waterspout. 7. Tornado alley is the region in the middle of the United States where tornadoes are most frequent. However, every U.S. state and every continent (except Antarctica) has experienced a tornado. 8. A tornado watch means that conditions are ripe for a tornado; a warning means that a storm has been spotted on the ground or via radar (and you should take cover immediately). 9. Since the first tornado forecast was made in 1948, tornado warning lead times have been increasing and now average 13 minutes. However, they have a 70 percent false alarm rate, which may lead some people to take them less seriously than they should. 10. Mobile homes aren’t more likely to get hit by a tornado than any other type of building, but their flimsy structure provides little protection against strong winds and flying debris. 11. It’s also a bad idea to take shelter in a car—which can be easily tossed about—or under a bridge, where a person would be vulnerable to flying debris or a bridge collapse. 12. The single deadliest tornado killed 695 people in Missouri, Illinois and Indiana on March 18, 1925. The series of tornadoes that struck Tuscaloosa, Alabama and other Southern states in April 2011 set a new record. According to NOAA, there were 312 recorded tornadoes that touched down from 8 a.m. on April 27 through 8 a.m. on April 28. The death toll these storms was over 250 people, and did not break the 1925 record mentioned above. 13. A tornado that struck Washington, D.C. on August 25, 1814, is credited with driving the British invaders out of the city and preventing them from carrying out further destruction. They had burned the White House and much of the city the day before. 14. The city of Greensburg, Kansas was flattened by a tornado in 2007, but instead of abandoning the town, the people are rebuilding with an emphasis on green technology. 15. In 2009 and 2010, more than 100 scientists participated in VORTEX2 (funded by the National Science Foundation and National Oceanic and Atmospheric Administration), which set out to track tornadoes as they formed and moved across the landscape. The V2 researchers are trying to answer many basic questions about tornadoes, such as how, when and why they form, how strong the winds get near the ground, how they do damage, and how predictions can be improved. During the two years, they collected data from dozens of storms and tornadoes. In order for a vortex to be classified as a tornado, the violently rotating column of air must be in contact with both the cloud above and the ground below.
Redtail monkeys ( (Smuts, et al., 1987)) are found in Africa from the Central African Republic eastwards through Kenya and south into Angola and Zambia. Populations are most dense in Uganda. Redtail monkeys can live in a rather large variety of habitats. They are mainly found in the middle canopy of tropical rain forest habitats. However, they have also been observed in swamp forests, secondary forests, riverine gallery forest, and other woodlands (Smuts et al. 1987). (Smuts, et al., 1987) This relatively small primate exhibits some sexual dimorphism in weight and body length. Males have an average mass of 4.1 kg and a length of approximately 46 cm. Redtail monkey females, in contrast, average 2.9 kg in mass and about 38 cm in length (Torstar Books 1984; Smuts et al. 1987). Other than size differences, males and females of this species are very similar. The recognizable markings of adult redtail monkeys include a black face, bluish skin around the eyes, a white spot on the nose, and white cheek fur. The name 'redtail' comes from the chestnut-colored fur on the underside of the tail. The rest of the body is covered with a speckled brown coat and gray or black limbs, depending on the subspecies (Torstar Books 1984). Redtail monkey infants have woolly gray fur at birth. Although they are born with a visible nose spot, young redtail monkeys have a brown tail and no cheek whiskers. As they mature, their markings begins to resemble those of adults (Kingdon, 1984). (Kingdon, 1984; Smuts, et al., 1987; Torstar Books, 1984) Redtail monkeys generally breed throughout the year, although the peak season is from November to February (Smuts et al., 1987). The majority of pregnancies produce a single infant. Although data are lacking for Cercopithecus have gestations ranging in duration from around 5 months to a maximun of 7 months. Newborns typically weigh around 400 g, and are entirely dependent upon the mother for transportation and nourishment (Nowak, 1999). It is reasonable to assume that is similar in these respects to other members of the genus., in general, species in the genus Males generally reach sexual maturity at the age of six, females mature at four or five years of age (Smuts et al., 1987). (Smuts, et al., 1987) As in most primates, parental care is mainly the responsibility of females. Young are altricial, and must be carried for the first several weeks of life. Mothers provide food (milk) for their young, as well as transportation and grooming. Female guenons typically have life-long associations with their kin. The dominance rank of a female within her social group will affect the dominance rank of her daughters. (Nowak, 1999; Smuts, et al., 1987) Although data are not available for this species, other members of the genus Cercopithecus are known to live in captivity for more than 30 years. It is likely that is similar to other members of the genus in lifespan. Lifespan in the wild is likely to be somewhat shorter than it is in captivity. (Nowak, 1999) This diurnal, arboreal species is quite agile and active. Their main hours of activity are in the early morning and late evening (Kingdon, 1984). Redtail monkeys tend to be found in medium-sized groups of 11 to 14 individuals containing one male and a matrilineal group of females (Chapman and Chapman, 2000). It is common for several of these troops to congregate together at food resources or in large trees during resting periods (Kingdon, 1984). Groups of redtail monkeys travel approximately 1.4 km each day in search of food. Allomothering, the sharing of maternal care by other females of the group other than the infant's mother, has also been observed in redtail monkey groups, although occasionally the infant is harmed in a fight for possession of the youth (Struhsaker and Leland, 1979). Groups defend their home ranges of about 120 hectares primarily through visual threats and, if necessary, physical combat (Smuts et al., 1987). (Smuts, et al., 1987) As in all primates, communication in this species is complex, and includes chemical, visual, auditory, and tactile components. The visual communication system consists of eyebrow raising, facial skin stretching, and head-bobbing (Estes, 1991). These signals are commonly used to warn potential predators or unwanted intruders. Vocal communication consists of birdlike chirps between members of a group (Kingdon, 1984). This form of communication is mainly used socially among members of the same unit. These associated individuals may also identify one another by nose-to-nose greeting, in which two individuals press their muzzles together. After this greeting they will commonly practice reciprocal social grooming or play (Estes, 1991). (Estes, 1991; Kingdon, 1984) Redtail monkeys are primarily frugivorous, but supplement their diet with leaves, insects, flowers, buds, and gum (Torstar Books, 1984; Chapman and Chapman, 2000). It is common for adults to store fruit in their large cheek pouches in order to take their meal to an area free from the threat of theft by other monkeys (Torstar Books, 1984). (Chapman and Chapman, Aug 2000; Torstar Books, 1984) chimpanzees, crowned hawk-eagles, wild cats, and humans (Kingdon, 1984; Leland and Struhsaker, 1993). It is also likely that these monkeys fall victim to the same predators that trouble other small, arboreal primates in African forests. These include leopards, snakes, and a variety of avian predators. (Nowak, 1999)is potential prey for Because these monkeys are frugivorous, and can transport fruits in their cheek pouches, it is likely that they play some role in seed dispersal. In addition, as a prey species, they probably have some effect on predator populations. (Nowak, 1999) Redtail monkeys have been instrumental in the regeneration of Strychnos mitis, a tree species found in the Kibale Forest. Redtail monkeys feed heavily on the fruit of this tree. As they eat the fruit, they spit the intact seeds, which fall to the rainforest floor where the seeds can successfully germinate. This method of seed sowing produces more saplings annually than the fruit would normally produce without the help of redtail monkeys (Lambert 1995). Redtail monkeys have also been useful as laboratory animals in studies on various viral diseases (Kingdon 1984). regularly practices crop raiding of nearby agricultural gardens containing maize, banana, millet, bean, pumpkin, pineapple, or passion fruit crops (Kingdon, 1984). In regions of low productivity this behavior has become a serious problem for neighboring human villages. Redtail monkeys are also one of the major carriers of yellow fever in Africa (Kingdon, 1984). When the monkeys venture into human villages to raid their crops, there is a greater chance that an infected individual could spread this disease to the villagers. (Kingdon, 1984) Although redtail monkey populations are currently healthy, there is some concern about their future status. As is the case with many rainforest dwelling animals, the threat of habitat loss by deforestation is a major concern. Sinceinhabits a relatively small area on the African continent, loss of habitat could be detrimental for the future of this primate species. Redtail monkeys are also threatened by predation. They are potential prey for chimpanzees, crowned hawk-eagles, wild cats, and humans (Kingdon, 1984; Leland and Struhsaker, 1993). Redtail monkeys are commonly found in close association with other primate species, such as red colobus, mangabeys, and blue monkeys. Redtail monkeys form an important feeding association with colobus monkeys. Colobus monkeys bite through the tough outer skins of Mondura fruits and redtail monkeys are able to eat the fruit scraps that contain ordinarily unobtainable fruit pulp (Leland and Struhsaker, 1993). They have also been observed to interact socially with other species; playing, grooming, and helping in defense from common predators. Redtail monkeys have been observed to mate with blue monkeys, and produce fertile offspring (Leland and Struhsaker, 1993). (Leland and Struhsaker, 1993) Nancy Shefferly (editor), Animal Diversity Web. Sarah Davis (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor. living in sub-Saharan Africa (south of 30 degrees north) and Madagascar. uses sound to communicate young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching. Referring to an animal that lives in trees; tree-climbing. having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria. an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness). uses smells or other chemicals to communicate ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds. union of egg and spermatozoan forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality. an animal that mainly eats fruit An animal that eats mainly plants or parts of plants. offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes). having the capacity to move from one place to another. the area in which the animal is naturally found, the region in which it is endemic. the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females. having more than one female as a mate at one time rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal. remains in the same area reproduction that includes combining the genetic contribution of two individuals, a male and a female associates with others of its species; forms social groups. uses touch to communicate Living on the ground. defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south. uses sight to communicate reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female. breeding takes place throughout the year Chapman, C., L. Chapman. Aug 2000. Constraints on Group Size in Red Colobus and Red-tailed guenons:Examining the Generality of the Ecological Constraints Model. International Journal of Primatology, 21 (4): 565-595. Cords, M. 1984. Mating Patterns and Social Structure in Redtail Monkeys. Z. Tierpsychol, 64: 313-329. Estes, R. 1991. The Behavior Guide to African Mammals. University of California Press. Kingdon, J. 1984. East African Mammals: An Atlas of Evolution in Africa Vol. 1. Chicago, Il: The University of Chicago Press. Lambert, J. 1995. Redtail Monkeys and Strychnos mitis: A Plant-animal Interaction in the Kibale Forest, Uganda. International Journal of Primatology, 71(5): 353-355. Leland, L., T. Struhsaker. 1993. Monkey Business. Animal Kingdom, 90: 24-37. Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press. Smuts, B., D. Cheney, R. Wrangham, T. Struhsaker. 1987. Primate Societies. Chicago, Il: The University of Chicago Press. Struhsaker, T. 1977. Infanticide and Social Organization in the Redtail Monkey. Z. Tierpsychol., 45: 75-84. Struhsaker, T., L. Leland. 1979. Advances in the Study of Behavior Vol. 9. Academic Press. Struhsaker, T., T. Pope. 1991. Mating System and Reproductive Success - A Comparison of 2 African Forest Monkeys. Behaviour, 117: 182-205. Torstar Books, 1984. All the World's Animals-Primates. New York, Toronto: Torstar Books Inc.
Growing Places (2011) informs us “The Child Centered Approach promotes the right of the child to choose, make connections and communicate. It allows freedom for children to think, experience, explore, question and search for answers. It presents a creative celebration of children's work” In child centered settings, children commence their own learning by choosing activities that interest them such as construction/sand play. They work in independent manners to discover their potential. Furthermore, child centered learning permits students to work in ways that complement their various learning styles. As Howard Gardner proved through research, children learn in many diverse ways and no one method is appropriate for all students in classrooms. Gardner, H (1983) “The types of intelligence that a person possesses, not only a person’s capabilities, but also the manner or method in which they prefer to learn and develop their strengths - and also to develop their weaknesses” A child centered approach is additionally imperative as it’s been confirmed through research to produce greater long term results compared to other methods, plus significantly improving social/emotional development ensuring children gain high self-esteem. Hersh, R (2009) states that “...child centered learning during early childhood produces greater long-term results than traditional programs. These studies also show that child-centered learning produces significant social and emotional developments” The child centered approach has limitations, activities such as trips, cooking and story activities will require adults to take the lead, Beaver, M (2008:214) “There will always be some aspects of the provision in which adults will need to take the lead”. This is because the safety of children will always remain paramount regardless of the approach in use. Also as all children come from different backgrounds and are brought up in different ways, Ispring Solutions...

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