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Inflammation of the brain as a result of a viral infection - Age, gender, genetics, and lifestyle are not significant factors Viral encephalitis is a rare condition in which the brain becomes inflamed as a result of a viral infection. Often, the meninges, the membranes surrounding the brain and spinal cord, are also affected. Viral encephalitis varies in severity. An attack can be so mild that it causes almost no symptoms and is barely noticeable. However, occasionally it is serious and potentially life-threatening. What are the causes? Many different viruses can cause viral encephalitis. Mild cases are sometimes the result of infectious mononucleosis. In addition, viral encephalitis still occurs as a complication of some childhood infections, such as measles and mumps, although routine immunization has made these disorders much less common. The most common cause of life-threatening viral encephalitis is the herpes simplex virus (see Herpes simplex infections). In tropical countries, viral encephalitis can be caused by mosquito- and tick-borne infections, such as yellow fever. In the past, the disorder was frequently caused by infection with the polio virus. However, this disease is now rare in developed countries as a result of routine immunization. What are the symptoms? Mild cases of viral encephalitis usually develop gradually over several days and may cause only a slight fever and mild headache. However, in severe cases, the symptoms usually develop quickly over 24–72 hours and may include: Nausea and vomiting. Problems with speech, such as slurring of words. Weakness or paralysis in one or more parts of the body. If the membranes that surround the brain become inflamed (see Meningitis), other symptoms such as a stiff neck and intolerance of bright light may develop. The person affected may have seizures. In some cases, there is drowsiness, which may progress to a gradual loss of consciousness and coma. How is it diagnosed? If viral encephalitis is suspected, you will be admitted to hospital. Your doctor may arrange for a blood test to look for signs of viral infection. You may also have CT scanning or MRI to look for areas of brain swelling caused by inflammation and to exclude other possible reasons for the symptoms, such as a brain abscess. A sample of the fluid surrounding the brain and spinal cord may be taken (see Lumbar puncture) to look for evidence of infection. You may have an EEG to look for abnormal electrical activity in the brain. Rarely, a brain biopsy is performed, in which a sample of tissue is taken from the brain under general anaesthesia and then examined to confirm the diagnosis. What is the treatment? Viral encephalitis that is caused by the herpes simplex virus can be treated with intravenous doses of aciclovir (see Antiviral drugs) and possibly also with corticosteroids to reduce inflammation of the brain. In severe cases, intravenous aciclovir may be given, even if the cause has not been identified. Anticonvulsant drugs may be prescribed if seizures develop. Severely affected people may need to be treated in an intensive therapy unit. What is the prognosis? It is often difficult to predict the outcome of viral encephalitis. People who have mild encephalitis usually make a full recovery over several weeks, but occasional headaches may occur for a few months. However, in severe cases, the condition may be fatal. Encephalitis caused by the herpes simplex virus often produces long-term effects, such as memory problems. In children, herpes simplex viral encephalitis may cause learning difficulties. The effects of this type of viral encephalitis can usually be minimized if treatment is begun early. From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited. The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.
Ornithophobia refers to the condition of having an abnormal, extreme, and persistent fear of birds. Sufferers may have an extreme fear of being attacked by birds - even if they rationally agree that this is unlikely to occur. Extreme fears (phobias) such as ornithophobia can lead to a variety of disturbing symptoms such as: Breathlessness; difficulty in thinking or speaking clearly; dizziness; dry mouth; fear of dying, "going mad" or losing control; feeling sick; nausea; palpitations, shaking; sweating profusely; or a full blown anxiety attack. Not all sufferers are affected by all possible symptoms, and some individuals may also have other reactions. Even though many adult sufferers of ornithophobia (and/or other fears/phobias) are aware that their fears are unreasonable, many still experience severe anxiety even when just thinking about the subject or situation they fear. However, phobias such as ornithophobia are a relatively common form of anxiety disorder and may be treated conventionally using cognitive behavioral therapy including exposure and fear reduction techniques. Drugs may also be offered, typically anti-anxiety or anti-depressants - particularly during the early stages of treatment. Other forms of treatment offered may include hypnotherapy, Emotional Freedom Technique (EFT) or other similar therapies.
- Two varieties of HTML tables on the web: - Layout tables - most common - linearize well - Data tables - do not linearize well - Data tables present data such as: - Financial results - Rainfall totals by city and month - TV listings - Bus Schedules - In layout tables, information in the cells stands on its own - In data tables, headings are crucial for understanding the data HTML tables on the web come in two varieties, layout tables and data tables. There is no question that the vast majority of tables on the web are layout tables, used to structure the visual appearance of the page. Often the structure of tables is remarkably complex, with tables nested in tables as much as seven deep. In the Navigation lesson we talked a little bit about how tables are read, or linearized, independently of how complex those tables are. At least the definition of the linearization algorithm is simple. Lay out the text a line at a time starting with the first cell of the first row; then move across the columns of the first row, then proceed to the second row, and so on. If you come to a table in that process, linearize it and then continue. Another description of linearzation is "source code order." If you look at the source code of a page, and remove all the table tags (<table>, <tr>, <td> <th>, etc.) then the resulting text is the linearized version of the table. Finally, if you want an easy technique to see the way tables are spoken, look at a site that uses tables for layout, and apply the Linearize function in the Tables menu of the web Accessibility Toolbar. You should make sure that your pages make sense when linearized in this fashion. As we discussed earlier, one of the simplest views of your page in linear form is provided by the "Lynx view," a rendering of the page as if you were using the Lynx text browser. The provides you the opportunity of seeing your page as if the browser were Lynx. Or you can use the Web Accessibility Toolbar, Check > Lynx Viewer. Usually the page will make sense. Unless, that is, one or more of your tables is really a data table, because, while layout tables usually linearize well, data tables do not. So what are data tables? How are they distinguished from layout tables? Data tables present things like financial results, rainfall totals by city and month, TV listings or bus schedules. What do these have in common? What is common is that the meaning of data in most cells of the table depends on heading information, which is usually in the first row and the first column of the table. You cannot know what the data means unless you are aware of the contents of the corresponding headings. For layout tables, information in various cells stands on its own. There are no headings - just table cells containing text and images. In contrast, headings are crucially important for understanding (or reading) data tables. That is the problem! Your tables must be designed and marked up in such a way as to ensure that assistive technology will know where the headings are and be able to announce them. Think of a TV listing -- for example, : Here is part of the text view of this table from IBM Home Page Reader, starting at the time indicator (and Heading), 7:30: George Lopez (Repeat) Law & Order (Repeat) <60 Minutes II Perfect Murder, Perfect Town (Repeat) <24 Hour Jewelry Celebration 24 Hour Jewelry Celebration <Ken Burns American Stories (Repeat) West Point (Repeat) International Intelligence Briefing Jack Van Impe Presents When you read this, you will find that important information, represented by the tabular structure, is lost. Because of spanned cells, there is no way to even guess the time slot for a program, even if you did remember the headings. Imagine searching for a program title and then trying to figure out at what time and on what channel it will be aired. Nearly impossible! This financial data table from has similar problems. Just imagine starting to read this table in the middle. It is hard enough to remember the column headings, let alone keep track of them as you view numeric data one cell at a time. Remember that visually you can quickly glance at row and column headers to understand a piece of data; you can't do that when you are reading the table linearly. There are a number of constructs in HTML 4.0 that contribute to making data tables accessible, that contribute to making it possible to listen to and understand a table. These are thoroughly discussed in the . We will discuss the three most important techniques for giving assistance to those with disabilities who are trying to interpret tabular information.
An Introduction To Waveriders Most vehicles flying above mach 5 have rounded noses and wing-edges, as this cuts down on the high thermal loading the vehicles receive when the boundary layer of air initially flowing past the vehicle's skin at high Mach number gives up most of its kinetic energy as heat. This is why the Space Shuttle, for example, has a rounded nose and wing leading-edges. Shockwaves, which always occur above Mach 1, and which bend back to glove the vehicle creating them at high Mach numbers, cannot bend themselves around rounded curves without physically detaching themselves from the vehicle skin. This means that there is a physical gap between the wing-edges and nose of say, the Space Shuttle, and its shock-surface. Hypersonic vehicles during re-entry generate lift only from the underside of the fuselage. The underside, which is highly inclined to the flow at a high angle of attack, causes in conjunction with the underside shock-surface, compressive lift in reaction to the inclined vehicle wedging the airflow downwards. If the wing leading-edges are rounded, and swept-back as on most hypersonic delta-winged vehicles, the underside shock-surface is detached, allowing a large fraction of the underside compressed airflow to leak out round the side of the wings through the gap between the shock-surface and the wing leading-edges. This wastes up to a quarter of the potential lift. Waveriders have sharp noses and wing leading-edges, which the underside shock-surface attaches to, therefore air flowing in through the shocksurface is trapped between the shock and the fuselage, and can only escape at the rear of the fuselage. Shocks are one-way, the second law of thermodynamics prevents air flowing back through a shock the way it came in. All the lift is retained, so although sharp edges get a lot hotter than rounded ones at the same air density, the improved lift means that Waveriders can re- entry glide at much higher altitudes where the air-density is lower. Re-entry heating is a function of air density, so infact waveriders suffer much reduced re-entry heating rates, provided their wing-areas are large compared to their mass. The waveriding concept: fitting sharp edges to any arbitrary hypersonic vehicle shape, evolved simultaneously in Britain and the U.S.S.R, though the only vehicle ever built (as far as is known) was the American XB-70 Mach3 bomber prototype, back in the early sixties. Most people think of two particular vehicle shapes in conjunction with the waveriding concept: The 'Caret' Waverider, in effect a triangular delta-wing bent down the middle to give negative dihedral. It roughly resembles an ascii Caret symbol: '^' in cross-section. The other generic vehicle shape resembles, the gothic-arch planform of a steam-iron with an inverted 'W' cross-section, and is derived from conic hypersonic flow solutions. Copyright STAAR Research, 1995-1999
Teenagers take less account than adults of people’s feelings and, often, even fail to think about their own, according to a UCL neuroscientist. The results, presented at the BA Festival of Science today, show that teenagers hardly use the area of the brain that is involved in thinking about other people’s emotions and thoughts, when considering a course of action. Many areas of the brain alter dramatically during adolescence. One area in development well beyond the teenage years is the medial prefrontal cortex, a large region at the front of the brain associated with higher-level thinking, empathy, guilt and understanding other people’s motivations. Scientists have now found that, when making decisions about what action to take, the medial prefrontal cortex is under-used by teenagers. Instead, a posterior area of the brain, involved in perceiving and imagining actions, takes over. Dr Sarah-Jayne Blakemore of the UCL Institute of Cognitive Neuroscience, giving the BA Festival’s BAYS lecture, said: “Thinking strategies change with age. As you get older you use more or less the same brain network to make decisions about your actions as you did when you were a teenager, but the crucial difference is that the distribution of that brain activity shifts from the back of the brain (when you are a teenager) to the front (when you are an adult). “The fact that teenagers underuse the medial pre-frontal cortex when making decisions about what to do, implies that they are less likely to think about how they themselves and how other people will feel as a result of their intended action. “We think that a teenager’s judgement of what they would do in a given situation is driven by the simple question: ‘What would I do?’. Adults, on the other hand, ask: ‘What would I do, given how I would feel and given how the people around me would feel as a result of my actions?’ The fact that teenagers use a different area of the brain than adults when considering what to do suggests they may think less about the impact of their actions on other people and how they are likely to make other people feel.” In the study, teenagers and adults were asked questions about the actions they would take in a given situation while their brains were being scanned using fMRI. For example, ‘You are at the cinema and have trouble seeing the screen. Do you move to another seat?’ A second set of questions asked what they would expect to happen as a result of a natural event eg. ‘A huge tree comes crashing down in a forest. Does it make a loud noise?’ Although teenagers and adults chose similar responses, the medial pre-frontal cortex was significantly more active in adults than in teenagers when questioned about their intended actions. Teenagers, on the other hand, activated the posterior area of the brain known as the superior temporal sulcus – an area that’s involved in predicting future actions based on past actions. While children start to think about other people’s mental states at around age five, this new data shows that the neural basis of this ability continues to develop and mature well past early childhood. A second piece of research presented at the festival shows that teenagers are also less adept at taking someone else’s perspective and deciding how they would feel in another person’s shoes. Participants aged eight to 36 years were asked how they would feel and how they would expect someone else to feel in a series of situations. Adults were far quicker than teenagers at judging emotional reactions – both how they would feel and how a third party might feel in a given situation. For example, ‘How would you feel if you were not allowed to go to your best friend’s party?’ or ‘A girl has just had an argument with her best friend. How does she feel?’ Dr Blakemore said: “It seems that adults might be better at putting themselves in other people’s mental shoes and thinking about the emotional impact of actions – but further analysis is required. The relative difficulty that teenagers have could be down to them using a different strategy when trying to understand someone else’s perspective, perhaps because the relevant part of the brain is still developing. The other factor to consider is that adults have had much more social experience.” “Whatever the reasons, it is clear that teenagers are dealing with, not only massive hormonal shifts, but also substantial neural changes. These changes do not happen gradually and steadily between the ages of 0–18. They come on in great spurts and puberty is one of the most dramatic developmental stages.” Source: University College London Explore further: Ebola reveals shortcomings of African solidarity
Hives (urticaria), also nettle fever, is a complicated and complex skin disease. It arises as a result of a hypersensitive reaction to various chemical and natural substances or external stimuli on the skin. Around 10 to 20 percent of people in Germany have had hives at some point in their lives. Hives are not contagious, but should be examined and treated by a doctor as soon as possible, as in some cases it can lead to circulatory shock and then a life-threatening situation. What is hives (urticaria)? Hives are known in medical terminology as urticaria and are characterized by characteristic red wheals on the skin that arise from smaller, reddened bumps. These can basically appear on any part of the body, some are more susceptible to it than others. See phonecations for All You Need to Know About Gastric Laryngitis. Acute urticaria is a form that lasts 6 weeks at the longest and then resolves. If the symptoms last longer, it is called chronic hives. Most hives are triggered by histamines secreted by the skin’s mast cells. As a result, the small elevations form first, which gradually spread to wheals. The reasons for the release of histamine are different. This can be an autoimmune reaction, for example. The body does not tolerate its own substances that it releases itself. In response, hives develop. However, there can also be a hypersensitivity to a substance that either comes into direct contact with the skin or passes through the digestive tract. These can be coloring or flavoring substances, but also pathogens such as bacteria, which only express themselves through this symptom. In rarer cases, there is a real allergy, which is noticeable by hives. The other two major causes of hives include the physically and psychologically induced condition. External stimuli such as pressure or scratching can cause red wheals to appear on the affected area, which disappear over time or only after a longer healing process. Stress or mental stress can also be the trigger of hives. Symptoms, Ailments & Signs The first signs of hives are itching and the typical wheals. As a result of the accumulation of water, the surface of the skin swells and inflamed areas develop, which are sharply defined and painful on contact. These wheals can be white to reddish and a few millimeters to two centimeters in size. Several wheals can combine to form a large-scale skin change. This can lead to bleeding and, in isolated cases, to the development of ulcers. Typical accompanying symptoms are also feelings of tension and skin irritations, for example sensory disturbances or overheating. Occasionally, the wheals are accompanied by so-called angioedema. This is cushion-like, swollen subcutaneous tissue that is usually painless. However, redness, itching and a feeling of tension can occur. Angioedema occurs mainly on the face, palms and soles. In some cases, the mucous membranes are also affected. Wheals resolve within a day. In chronic hives, the skin changes can last for weeks, months or even years and affect large areas of the skin. If hives occur as part of an allergy, anaphylactic shock can occur, which is associated with shortness of breath, outbreaks of sweating, tachycardia and finally circulatory shock. course of the disease The course of hives depends on the form of the disease. In the acute form, the disease usually only lasts a few days or a few weeks. The maximum duration of acute hives is six weeks. As already mentioned, typical symptoms are a very itchy skin rash with reddish wheals and, in rare cases, painful swelling of the skin. Chronic hives, however, can last up to several years or appear again and again. However, the symptoms of acute hives are less common. Chronic hives should always be treated by a doctor to investigate the cause and thus identify potential allergies, or hypersensitivity to certain foods that are responsible for the chronic hives. In most cases, those affected by hives suffer from various skin complaints. These are very uncomfortable and can mean a significantly reduced quality of life for those affected. In most cases, a rash develops on the skin. This rash is also associated with itching, so scratching can also form scars. Children in particular scratch themselves constantly, which can also lead to bleeding. The skin itself is white in color on the affected areas and also slightly swollen in some cases. Hives can also spread to the tongue or mucous membranes. It can also lead to shock and, in the worst case, heart failure. However, this case occurs only very rarely. As a rule, hives can be reduced relatively easily with the help of medication. The patient may need light therapy. However, no particular complications arise. The hives usually do not negatively affect the life expectancy of the patient. When should you go to the doctor? If the skin symptoms remain unchanged for days, this should be clarified by a doctor. If skin changes increase, a doctor’s visit is advisable in the next few days. If itching, antipruritic medication may be needed. Which medications are suitable or what alternatives there are to drug therapy can be clarified with your family doctor. If shortness of breath, circulatory problems or swelling of the body occur, emergency action is required as a life-threatening condition can arise. If swelling occurs, for example on the face, an emergency medicine specialist can quickly alleviate the symptoms with medication. In the case of chronic courses, urticaria advice can be sought in special treatment centers. The focus here is on helping people to help themselves. This avoids frequent visits to the doctor, which can reduce the quality of life. If you are unsure whether a doctor’s visit is necessary, it is advisable to do so as a precaution. Accompanying psychological complaints, which are a consequence of the itching, for example, can also be addressed by the family doctor. A further referral to specialists who specialize in psychological support or skin diseases is made by the general practitioner. Treatment & Therapy Acute urticaria is usually not treated. In most cases, the wheals will go away on their own. Depending on the cause, this can happen within a few minutes, but it can also take a few weeks. Chronic hives are treated with antihistamines and cortisol. However, both active ingredients only suppress the symptom of an underlying disease. Therefore, it must be determined at the same time why chronic hives developed. It can only be permanently eliminated if the trigger is also eliminated. If there is an underlying bacterial infection of the digestive tract, hives will only go away permanently if the bacteria are fought and killed. Accordingly, individual therapy with specific drugs for the respective disease is required. Drugs do not help with psychological causes. In such cases, it is important to find the trigger and eliminate it in the long term. A psychologist can help with this. Outlook & Forecast There are already very good treatment options for hives these days. The most important thing is to find out what caused the disease. This can be done by keeping a diary. If the drug treatment works well, the patient can be symptom-free. The unpleasant hives are prevented by avoiding the trigger and by taking long-term medication. The prognosis of hives is therefore very good with successful treatment. If left untreated, hives lead to spontaneous swelling of the skin, redness, itching and burning. The symptoms are very uncomfortable for those affected. They can last up to 24 hours and severely restrict the patient’s everyday life and quality of life. Insomnia, loss of concentration and performance (at school or work) are not uncommon. As a result, sex life can suffer and depression, withdrawal and anxiety can massively affect those suffering from hives. The prospect of healing or learning to live with the disease is very good in today’s modern medical age. There is not only sufficient specialist literature for extensive research into the causes, but also enough medicinal and homeopathic approaches that enable a symptom-free life with hives. Hives can only be prevented if the cause is known. If it is physical, it is important to avoid situations in which it could arise again. In allergic reactions, the body must be kept away from the substance to which it is reacting. The same applies to hives that occur as a result of an intolerance. Prevention becomes more difficult when it comes to psychosomatic hives. Since stress in particular can hardly be avoided effectively in everyday life, the patient must be taught to process stressful situations effectively and thus prevent the development of physical symptoms. When those affected have gone through the acute treatment phase, it must be determined which trigger has caused the hives. This may be induced by chemical or biological factors such as infection, food, medication, or insect venom, or it may be the result of physical irritation from friction, cold, pressure, heat, or light. If there is a high probability that the trigger is in the diet, an elimination diet should be followed. This is important to avoid serious complications such as glottic or Quincke edema in the future. With this special form of nutrition, the patient receives only tea, water, potatoes and rice for a week. These foods are generally considered to be minimally irritating, meaning they contain no flavors, fragrances, colors, or preservatives that could lead to urticaria. When the immune system has been cured after a week of dieting, the series of provocation tests begins in the follow-up care. Gradually, the patient receives a food that may be responsible for the hives. The cause can be identified through strict documentation of the skin and mucous membrane reaction. The provocation test also includes a skin test in which a small area is exposed to various physical stimuli. Here, too, the reactions are precisely documented. If those affected then know about the causes of urticaria, they can avoid this unpleasant condition in the future. You can do that yourself In everyday life, people affected by hives should ideally know exactly what they are allergic to. This makes it possible to avoid certain ingredients as much as possible. It is not always easy to find out what you are reacting to with hives. It can therefore be helpful to keep a log: When do the wheals appear and in what context? Sometimes it is possible to identify a trigger for the itching and wheals with a close-meshed protocol. Especially when potential triggers of hives are unclear, it is important that those affected have the necessary medication in their medicine chest. The hives can be so severe that the eye swells up completely. In the worst case, the respiratory tract can also be obstructed in severe uricaria. Self-help in acute cases is not possible here. While milder symptoms of hives in everyday life can often be alleviated by appropriate antihistamines, shortness of breath is always a medical emergency. Relatives should be familiar with the external symptoms and know that they must call an emergency doctor immediately if they have difficulty breathing. This can quickly stop the allergic reaction with special drugs that are administered intravenously.
Italy lies between 35 ° 29ʹ ( Lampedusa ) and 47 ° 05ʹ north latitude, and between 6 ° 33ʹ and 18 ° 30ʹ east longitude. The border to the north with Switzerland and Austria follows largely the watershed between Po and the Danube. In the west, the border with France mainly follows the watershed between Po and Rhone. The border with Slovenia was established following a referendum after the Second World War and does not follow any natural boundary lines. The sea border is formed by the Ligurian Sea, the Bonifacio Strait, the Tyrrhenian Sea, the Sicily Sea, the Ionian Sea, the Otranto Strait and the Adriatic Sea. Italy is geologically a relatively young country, formed during the alpine mountain range that took place in the tertiary between 70 and 10 million years ago. Both the Alps and the Appennines belong to this folding mountain system. After the folds, the country has been exposed to vertical shifts, including periods of subsidence. These offsets have largely occurred along fracture lines, where there was already a considerable volcanic activity already in the Tertiary period. An earthquake still occurs (an earthquake killed more than 3,000 people southeast of Naples in November 1980), and Mount Vesuvius, Etna and Aeolian Islands is one of the most active volcanic regions in Europe. The geological development has led to the formation of a number of natural landscapes or small regions, which can be divided into three main areas: the Alps, Posletta and the Appennines, as well as the islands of Sicily and Sardinia. Within Italy’s borders are found almost the entire inside of the alpine arch, including parts of the Western Alps, the Central Alps and the Eastern Alps. The Western Alps rise like a wall from Posletta and consist mainly of crystalline rocks. The valleys here are very short or almost completely missing. The highest parts are the Greek Alps (Gran Paradiso 4061 meters above sea level), the Mont Blanc massif, which in Italy rises to 4700 meters above sea level, and the Wallis alps (Alpi pennine) with Monte Rosa (4634 meters above sea level) and Monte Cervino ( German Matterhorn, 4478 meters above sea level) on the border with Switzerland. The Central Alps consist of powerful strata of Mesozoic and Tertiary limestones, reaching into the Rätian Alpsover 4000 meters (Piz Bernina 4049 meters above sea level). Here the ice has excavated a number of north-south valleys, today partially filled by lakes: Lake Maggiore, Lake Como, Lake Iseo and Lake Garda. These, at the southern end, are dammed by large moraine ridges, are deep and have a great influence on the local climate. Further east, the Alps eventually pass into the Dolomites, which consist of heavily folded limestone deposits. The highest reaches of Marmolada (3342 meters above sea level). At the far east, the border with Austria is formed by the Karnian Alps. The entire alpine area is strongly shaped by the ice with pointed peaks, bottoms and eggs. A number of deep valleys lead up to pass over the watershed. For example, Dora Riparia leads up to Mont Cenis Pass (2082 meters above sea level), Dora Baltea up to Lille (2188 meters above sea level) and Store (2472 meters above sea level) St. Bernhard Passes, Ticino Valley to St. Gotthard Pass (1154 meters above sea level) and the Adige valley to the Brenner Pass (1370 meters above sea level). Posletta is a subsidence area ( geosynclinic ) between the Alps and the Appennines filled with late tertiary and quaternary, up to 10 kilometers thick sediments, and was previously a shallow sea bay. Sletta, which in Italian is called Pianura Padana, covers an area of 46,000 square kilometers and is over 320 kilometers long and up to 200 kilometers wide. The upper parts (Alta Pianura) consist of gravel and sand deposits, the lower parts (Bassa Pianura) of clay. The gravel-sand plains are very water-permeable and therefore dry, so that irrigation must be used in great style, but the rainwater breaks out again in a source zone where the upper and lower parts of the plain meet. The rivers from the Alps have cut the upper part of the plain into a number of separate plateaus. They unite in Po (652 kilometers long), which extends into the Adriatic into a large delta, where sand, gravel and clay particles are sedimented. To the west of Padova, two extinct volcanoes rise over the plain: Monti Berici (421 meters above sea level) and Colli Euganei (603 meters above sea level). Apennines. From Passo della Cisa on the border between Tuscany and Emilia-Romagna. The Apennines, which extend along the entire peninsula and continue along the north coast of Sicily, are made up of Mesozoic and Tertiary limestones and clay slates, which were folded into tertiary. The height varies mostly between 750 and 1800 meters, with the main chain closest to the Adriatic Sea. All the way north, at Savona, the Appennines cross into the Ligurian Alps on the border with France. These mountains are called Ligurian Appennines, and are easy to pass at Genoa (Passo dei Giovi, 472 meters above sea level). East of the Taro River follows the Tuscan Appennines with Monte Cimone (2165 meters above sea level) as the highest point. To the west of the Tuscan Appennines is a small mountain area, Apuan Appennines, which consists of transformed sediments, including the famous marble at Carrara. Monte Pisanino (1946 meters above sea level) is the highest point in this group. At the Bocca Serriola pass, Tuscan Appennines turn into Roman Appennines, which consist of several parallel chains made up of limestone. The highest is Abruzzi, which reaches 2912 meters above sea level on the Gran Sasso d’Italia (Corno Grande), the highest mountain in the Italian peninsula. To the west of the main chain are lower parallel chains in Umbria and the Sabiner mountains, which reach all the way down to Rome. Neapolitan Appennines begin south of a line fromGaeta to the Adriatic. The chain bends away from the Adriatic Sea and approaches the Tyrrhenian Sea, as it reaches south of Naples. The mountains reach their highest point in the Serra Dolcedorme (Pollino, 2267 meters above sea level) in Calabria. The Apennines’ western foreland extends from La Spezia in the north to the south of Naples. Almost everywhere there is a low coastal plain with dunes and shores, and behind these often swampy fields. The northern part of Tuscany, around the river Arno, is a hilly country. The highest point here is Monte San Michele (893 meters above sea level). Further south, the landscape is strongly characterized by volcanic activity. The highlands between Monte Amiata (1738 meters above sea level) in southern Tuscany and the Albanian mountains south of Rome are of volcanic origin. The lakes of Bolsena, Vico, Bracciano, Albano and Nemi lie in the craters of extinct volcanoes. Also the scenic fields north of the Gulf of Naples and the islands of Ischia, Procida and Ponza are volcanic. Mount Vesuvius (1277 meters above sea level), Italy’s most famous volcano, dominates the Gulf of Naples. To the southeast, on the “heel” of the Italian peninsula, the Appennines are separated from the isolated Monte Gargano (1056 meters above sea level) on the “track” of the low limestone plateau of Puglia. Sicily: Taormina with parts of the ancient Greek amphitheater. In the background to the left volcano Etna. Sicily, like the Italian peninsula, consists mostly of mountain and hinterland. The mountains along the north coast are a continuation of the Appennines, and consist alternately of limestone, clay, sandstone and crystalline rocks. The mountains continue to the west in the Egyptian islands. Etna (3323 meters above sea level) is Europe’s highest active volcano and covers an area of about 1200 square kilometers. The Aeolian islands north of Sicily, including Vulcano and Stromboli, are all volcanic. Ustica, further west, is an isolated volcanic island. In the Strait between Sicily and Tunisia are three Italian islands: Pantelleria, Linosa and Lampedusa. The first two are volcanic, the latter consisting of limestone. Sardinia is for the most part composed of crystalline rocks of much older date than the rest of Italy. A massive block covers the island’s eastern two-thirds. This is separated from the smaller Iglesian massif at the Campidanol catchment. The island’s highest point is Gennargentu (La Marmora, 1834 meters above sea level).
The researchers say their study, which was funded by the EAT Forum and independent global health non-profit Wellcome, is the first to quantify how food production and consumption affects planetary boundaries, a term that describes the safe operating space for humanity beyond which Earth’s vital systems could become unstable. Several of these boundaries have already been crossed, they write, particularly those concerning climate change and biogeochemical flows related to nitrogen and phosphorous cycles. “If socioeconomic changes towards Western consumption patterns continue, the environmental pressures of the food system are likely to intensify, and humanity might soon approach the planetary boundaries for global freshwater use, change in land use, and ocean acidification,” the study reads. “Beyond those boundaries, ecosystems could be at risk of being destabilized and losing the regulation functions on which populations depend.” Essentially, the researchers argue there are three areas for action: adopting more plant-based ‘flexitarian’ diets that reduce meat and dairy intake; improved land management practices and climate-smart agriculture; and thirdly, cutting food loss and waste in half. In part II of our coverage on this Nature article published next week, FoodNavigator speaks to co-author and science director of EAT and the Stockholm Resilience Centre, Dr. Fabrice DeClerck PhD, who offers advice to manufacturers and suppliers on how to be part of the solution. "But it has to be a combination because with just one of these measures we will not make it without exceeding environmental boundaries," said co-author Wim de Vries of Wageningen University. The researchers provide country-specific data and a series of scenarios produced specifically for the study that offer “a good starting point” for this endeavour. “[…] When the solutions are implemented together, our research indicates that it may be possible to feed the growing population sustainably,” said a statement by lead author Dr Marco Springmann of the University of Oxford. De Vries added: “Without concerted action, we found that the environmental impacts of the food system could increase by 50-90% by 2050 as a result of population growth and the rise of diets high in fats, sugars and meat. In that case, all planetary boundaries related to food production would be surpassed, some of them by more than twofold.” A global shift to more plant-based diets globally could reduce agriculture- and food production-related greenhouse gas emissions by more than half. It would also reduce the use of fertilizer, cropland and fresh water from between one-tenth and a quarter. A variety of measure is needed to bring about the necessary dietary changes, including food labelling, taxes and subsidies, awareness campaigns and education. “Integrated, multicomponent approaches that include clear policy measures might be best suited for changing diets”. “An important first step would be to align national food-based dietary guidelines with the present evidence on healthy eating and the environmental impacts of diets,” they add. It is believed that over one-third of all food we produce is either lost before it reaches the market, or is wasted by households. To reduce this, the scientists argue for a two-pronged approach depending on the underlying cause. In developing countries, where food waste is mostly caused by food spoiling due to a lack of facilities, investments must be made in agricultural infrastructure, technological skills, cold storage, transport and distribution. Meanwhile, in developed countries, they call for education and awareness campaigns, food labelling, improved packaging that prolongs shelf life and changes in legislation and business behaviour that promote closed-loop supply chains. Halving the amount of food wasted alone could reduce environmental impacts by up to one-sixth, the researchers calculate. As for making farming more ‘climate-smart’, the study calls on producers to adopt sustainable practices such as recycling fertilizers and improving water management. The authors conclude: “Synergistically combining improvements in technologies and management, reductions in food loss and waste, and dietary changes towards healthier, more plant-based diets, with particular attention to local contexts and environmental pressures, will be a key challenge in defining region specific pathways for the sustainable development of food systems within the planetary option space.” “Options for keeping the food system within environmental limits” Available online 10 October 2018, doi.org/10.1038/s41586-018-0594-0 Authors: Marco Springmann, Michael Clark, Daniel Mason-D’Croz, Keith Wiebe, Benjamin Leon Bodirsky et al.
Here in the United States, we use US customary units of measurement, such as pounds, feet, and inches, for most of our daily activities. However, we are also accustomed to seeing—and sometimes using—the metric system adopted by most other countries. So, should we use metric or US customary units of measurement in our writing? Before answering that question, let’s take a closer look at the names US customary units of measurement and the metric system. The Names: The Metric System and US Customary Units of Measurement The metric system is officially called the International System of Units, commonly abbreviated as SI units. However, unless your writing is highly technical or scientific, you can safely follow the lead of one of our primary scientific style guides, the Publication Manual of the American Psychological Association (APA style), which uses the name metric instead of SI.1 US customary units of measurement are based on the historical imperial units of measurement previously used in the United Kingdom.2 Although not identical, US customary units of measurement are sometimes called imperial units or English units. In addition, they are sometimes called US standard units or conventional units. Three Guidelines for Using Metric and US Customary Units of Measurement The three guidelines below explain when to use metric and when to use US customary units of measurement in writing. Note that if you are following a specific style guide, that guide’s recommendations should always override the information presented here. 1. Use the metric system in technical, scientific, and medical writing. Technical, scientific, and medical publications almost always use the metric system abbreviations rather than US customary units. Part A is attached 5 cm behind Part B. The patient lost 4 kg of body weight per month. In fact, the following style guides require the metric system for most lengths and weights: Publication Manual of the American Psychological Association (APA style)3 (See the Style Guide Alert below.) Scientific Style and Format from the Council of Science Editors (CSE style)4 AMA Manual of Style from the American Medical Association (AMA style)5 Style Guide Alert: APA Style Although the Publication Manual of the American Psychological Association (APA style) recommends the metric system, it acknowledges that US customary units may be necessary under certain circumstances. In those situations, include the metric equivalent in parentheses.6 The test subjects walked at least 1 mi (1609.34 m) per day. 2. Use US customary units of measurement in nontechnical writing. US customary units can be used in most general and business writing intended for a US audience. They can also be used in most academic writing in the humanities. The average car weighs two tons. The coffee table is forty-seven inches long. As shown in the examples above, US customary units are normally spelled out rather than abbreviated.7 The choice to use numerals or spell out the numbers connected to the units of measurement will depend on your style guide. In an upcoming post, we will look at when—and how—to abbreviate US customary units in specific situations. 3. Mix metric and US customary units of measurement when necessary. Follow the advice of The Associated Press Stylebook (AP style) if you are writing nontechnical content for an international audience by including both US customary units and metric units.8 If your primary audience is in the United States, place the metric conversion in parentheses directly after the US customary unit: The kitten weighs approximately 2 pounds (1 kilogram). If your primary audience is outside of the United States, place the US customary unit conversion in parentheses, instead: JoAnne used about 3.79 liters (1 gallon) of gas driving to the airport. Both units of measurement are spelled out and rounded to avoid decimals or long number strings, when possible. Again, the choice to use numerals or spell out the numbers connected to the units of measurement will depend on your style guide. You can find many conversion charts online, including this unit conversion web page provided by the National Institute of Standards and Technology. 1. Publication Manual of the American Psychological Association, 7th ed. (Washington, DC: American Psychological Association, 2020), 6.27. 2. “Imperial units,” Encyclopedia Britannica, accessed January 7, 2020. 3. Publication Manual of the American Psychological Association, 6.27. 4. Council of Science Editors, Scientific Style and Format, 8th ed. (Chicago: University of Chicago Press, 2014), 12.2.3. 5. American Medical Association, AMA Manual of Style, 10th ed. (New York: Oxford University Press, 2007), 18.5.1. 6. Publication Manual of the American Psychological Association, 6.27. 7. The Chicago Manual of Style, 17th ed. (Chicago: University of Chicago Press, 2017), 9.13. 8. The Associated Press Stylebook 2022–2024 (New York: Associated Press, 2020), 188–89. Updated June 21, 2022
Cracking the Code, The world of machines and mechanisms is a complex and interconnected web of precision and ingenuity. From the smallest gears in a watch to the massive engines that power our vehicles, these mechanical systems are a testament to human innovation. But behind their seemingly magical functionality lies a well-kept secret—machine and mechanism theory. In this article, we embark on a captivating journey to crack the code, exploring the hidden secrets of machine and mechanism theory and unraveling the principles that make these mechanical marvels work. 1. The Essence of Machine and Mechanism Theory: Machine and mechanism theory is the backbone of mechanical engineering, providing a systematic approach to understanding the behavior and function of machines and mechanisms. At its core, it seeks to explain how these systems convert and transmit motion, force, and energy to perform useful tasks. By studying the theory, engineers gain the knowledge necessary to analyze, design, and optimize various mechanical systems. 2. Kinematics: The Language of Motion: One of the fundamental pillars of machine and mechanism theory is kinematics—the study of motion without considering the forces involved. It focuses on describing the position, velocity, and acceleration of individual components within a system, enabling engineers to understand how these parts move relative to one another. Kinematics forms the language through which we communicate and analyze the intricate dance of motion in mechanical systems. 3. Dynamics: Decoding the Forces: While kinematics explains motion, dynamics unravels the mystery of forces within machines and mechanisms. By applying Newton’s laws of motion, engineers can analyze how forces act upon different components and how these forces affect the overall motion of the system. Dynamics provides insights into the cause-and-effect relationships between forces and motion, helping engineers optimize performance, minimize energy loss, and ensure system stability. 4. Mechanism Design: The Art of Creating Motion: At the heart of machine and mechanism theory lies the art of mechanism design. Engineers employ their understanding of kinematics and dynamics to create mechanisms that translate motion and transmit forces in desired ways. Whether it’s the intricate linkage systems of a robotic arm or the complex gearing of an automotive transmission, mechanism design requires a deep understanding of the principles governing motion and force transmission. 5. Control Theory: Mastering the System: Control theory complements machine and mechanism theory by focusing on how to manipulate and regulate the behavior of mechanical systems. It involves the integration of sensors, actuators, and feedback loops to monitor system variables and adjust parameters in real-time. Control theory allows engineers to achieve precise control, stability, and response characteristics in machines and mechanisms, enabling automation, robotics, and advanced control systems. 6. Real-World Applications: The secrets of machine and mechanism theory find applications in countless industries and domains. From transportation and manufacturing to healthcare and aerospace, mechanical systems powered by this theory drive progress and innovation. Advanced robotic systems in manufacturing streamline production, while precise mechanical systems in medical devices enhance patient care. The applications are vast, and the impact is far-reaching. 7. Challenges and the Future: As we continue to delve into the secrets of machine and mechanism theory, challenges and opportunities lie ahead. The ever-increasing complexity of machines and the integration of emerging technologies like artificial intelligence and nanotechnology present new frontiers to explore. Additionally, the sustainable and ethical design of machines and mechanisms calls for a thoughtful approach, ensuring that our technological advancements align with societal needs and environmental considerations. 8. Unleashing the Power of Discovery: Cracking the code of machine and mechanism theory is a journey of discovery and wonder. It is a journey that unveils the hidden mechanisms behind our mechanical world, sparking creativity and innovation. With each revelation and breakthrough, engineers and researchers push the boundaries of what is possible, unlocking new possibilities and shaping the future of technology. The secrets of machine and mechanism theory empower us to create more efficient, reliable, and versatile mechanical systems that enhance our lives and drive progress. Cracking the Code of machine and mechanism theory allows us to unravel the secrets that lie beneath the surface of mechanical systems. By understanding the principles of kinematics, dynamics, mechanism design, and control theory, we gain the ability to analyze, design, and optimize machines and mechanisms in various industries. This knowledge opens doors to innovation, enabling us to create advanced robotics, efficient engines, precise medical devices, and more.
Kalina Grabb studies some of the ocean’s most reactive chemicals By Daniel Hentz \| February 5, 2020 Kalina Grabb is a marine geochemist and MIT-WHOI Joint Program student, specializing in the study of reactive oxygen species (ROS) in the ocean. An alumna of Harvard University, Grabb spent her formative years researching the lifecycle of sulfur, nitrogen and oxygen in the ocean system. After graduating, she was awarded a Fulbright Fellowship and conducted independent research at the Ocean University of China in Qingdao, where she studied nitrogen cycling within the Yangtze River. She is now a member of Colleen Hansel’s microbial geochemistry lab, where she has played an integral role in the development of DISCO, or Diver-operated Submersible Chemiluminescent sensOr, which performs in situ measurements of volatile chemicals produced in marine ecosystems. You've spent a good deal of your time at WHOI studying highly reactive superoxide. What is this chemical and why is it so important to study it? Superoxide is a type of reactive oxygen species (ROS), which comprises short-lived oxygen-containing molecules that play essential roles in the health and biogeochemistry of the ocean. They are produced and destroyed by any organism that utilizes oxygen––including us! When they build up inside of humans, they can lead to oxidative stress and can be linked to cancer, heart disease, aging, and many other detrimental health conditions. This is why we are encouraged to eat antioxidants, such as blueberries and dark chocolate. However, while we traditionally think of ROS as having negative impacts, more recent evidence indicates that ROS is also vital for some essential biological processes. At the right concentrations, ROS can help with cell signaling, growth regulation, fending off pathogens, and more. The balance of ROS within an organism is similar to a “Goldie Locks” effect. If you have too much, it is harmful; if you have too little, some essential biological functions fail. We have known that ROS plays a vital role in the health of other marine organisms, however, it wasn’t until a few years ago that we discovered that coral reefs were associated with extremely high concentrations of superoxide. In the dire state of coral reefs today, it is extremely important to understand how this chemical affects their health. Superoxide may be playing an unrecognized, yet critical role. You're a part of WHOI's Broader Impacts Group (BIG), where you've sought to educate others about coral conservation. What knowledge do you try to impart through outreach? I like to educate people about the beauty, vitality, and vulnerability of coral reef environments. I hope others learn to care for our coral reefs, which can inspire them to make small changes to help sustain ocean life, protect our coastlines, and preserve their beauty. I feel really lucky to have found my passion through ocean science, so I want to inspire younger generations from all backgrounds to discover their passion. Not everyone has the chance to be acquainted with the ocean, so it is extremely important to access diverse populations and share with them a small part of what we know and what we study. With the advent of technologies like DISCO, how do you think your field will change in the next decade? DISCO is just one example of technologies that are increasing our capacity to collect in situ measurements in novel ways. But it’s also non-invasive, which means we can use it without disturbing the reef ecosystem. The real-time data collection assists in previewing the superoxide concentrations during collection so that we can amend our surveys based on current observations. While these are only a few features of DISCO, overall advancement in technology within the field of oceanography is allowing scientists to ask and answer questions that they could not before. While there are many new instruments being developed in the field, DISCO, in particular, could continue to increase the sampling capabilities that allow us to better understand organisms in their natural environment. What made you choose to study at Woods Hole Oceanographic Institution? As a perspective student, I was interested in being surrounded by cutting edge ocean research, but what I really underestimated was the importance of the people. In particular, I feel privileged to work on this project and with my advisor, Colleen Hansel, whom I really admire both as a scientist and as a person. I am constantly impressed by the innovative way that she approaches scientific questions that leads us to explore questions from unique angles. She is a great role model for how to be an incredible scientist while also balancing family life. As a whole, WHOI happens to have some of the world’s leading experts in a wide range of disciplines, so it is easy to gain insight into tangential areas of study and discuss with others potential ways to collaborate. People here are readily willing to help and explain things so that others can understand. Since the beginning, I always felt WHOI scientists valued students’ opinions and treated us more as peers rather than pupils. Here, I feel I’ve been in a nurturing environment that allows me to grow as a scientist, yet one that also pushes me to learn skills that I did not think were possible. I am extremely thankful to be a part of this community.
Overview and Objective In this lesson, students explore a game to build the background knowledge needed to classify and define the terms factor, multiple, prime, and composite. The game introduces the idea as to why 1 is neither prime or composite. The game is played by taking turns selecting a number on a hundreds chart, and then collecting points. A point is scored for each unique rectangular array that they can create with that number of square tiles. This activity can be used with younger students who can identify numbers up to 100, and who have the dexterity to use a mouse. This activity can also be used with high school and upper level mathematics as it explores number systems such as highly composite, abundant numbers, superior numbers and their intersections. Invite students to explore how many unique rectangles they can make with 100 square tiles. Share this Polypad with students so they can explore this question. This video shows how to “push and pull” the merged squares to find rectangles and how to duplicate and recolor rectangles so that students can see all of their findings. Click here to learn more about using Number Tiles on Polypad. Be sure to include a 1 x 100 and a 100 x 1 as different rectangles. This will set the groundwork for why 1 is not prime or composite. Also, 100 is a perfect square, so remind students that squares are a type of rectangle, and should be included. There are a total of 9 unique rectangles: 1x100, 2x50, 4x25, 5x20, 10x10, 20x5, 25x4, 50x2, and 100x1. Play the Rectangle Game. Make a copy of this gameboard and then share a copy with students. Each player clicks on a number on the gameboard to open a Polypad with that number of square tiles. They find as many unique rectangles as possible (note: 1 x 3 is different than 3 x 1). Then score a point for each unique rectangle. 3 has two unique rectangles (3x1 and 1x3), so this would score 2 points. 4 has three unique rectangles (4x1, 2x2, 1x4), so this would score 3 points. Once points are scored, players can block that number using a colored chip. After four rounds, the player with the most points is the winner. Students can play additional games as time allow. Gather as a class to discuss the following. Worst Gameboard Number: 1. It only has 1 rectangle (1x1). Because it only has 1 factor, it is not prime, but it is also not composite. Bad Gameboard Numbers: 2, 3, 7, 11, and other prime numbers because you can only make 2 rectangles. Good Gameboard Numbers: 4, 6, 8, 9, 10, 12 and other composite numbers because you can make multiple rectangles. Best Gameboard Numbers: 60, 72 and 96 because you can make the most (12 rectangles) with these 3 numbers. These numbers have the most factors of any number under 100. Amount of different rectangles: factors Flipped rectangles: (example: 3 x 2 and 2x 3) use the same factors and are an example of the commutative property of multiplication. Square rectangles: (example: 2 x 2) these are square numbers because the two sides use the same factor. - Smallest Gameboard number with the most rectangles: 60 because it is a highly composite number. Highly composite numbers is a positive integer with more divisors than any smaller positive integer has. - Upper level mathematics number theory terms: Highly composite number, smooth number, abundant number, superior number Support and Extension To help support students, ask them the following: Sarah picked 100, because it was the biggest number. She scored 9 points because she found 9 different rectangles (one of which was a square). Zarah found another number on the gameboard that would give her more points than Sarah. What number could it be? For an extension question, ask students the following: What if the gameboard extended to 1,000. What are the best gameboard numbers? Polypad and Gameboard For This Lesson To assign these to your classes in Mathigon, save a copy to your Mathigon account. Click here to learn how to share Polypads with students and how to view their work.
RAJASAURUS NARMADENSIS – THE DINOSAUR NATIVE TO NARMADA VALLEY Recent excavations in the Narmada valley, have revealed that Rajasaurus Narmadensis, an endemic species of dinosaur, was existing in the Narmada valley during Cretaceous period [also known as the ‘K-period’]. The K-period spanned between Jurassic period (145 million years ago) and Paleogene Period (66 million years ago). In the History – Rajasaurus Narmadensis is a species of carnivorous abelisaurid theropod dinosaur from the late Cretaceous of India. Not many of us are aware that India was once a home to a number of dinosaurs from the early Triassic to the late Cretaceous. Gujarat is one of the few states of India that contains a wealth of dinosaur fossilized remains. Rajasaurus is a genus of carnivorous abelisaurid theropod dinosaur from the Late Cretaceous of India, containing one species – Rajasaurus Narmadensis. The bones were excavated from the Lameta Formation (a sedimentary rock formation found in Madhya Pradesh, Gujarat, and Maharashtra, India) in the Gujarat state of Western India, probably inhabiting what is now the Narmada River Valley. The generic name Rajasaurus derives from the Sanskrit rāja, meaning ‘king, sovereign, chief, or best of its kind’ and Ancient Greek sauros, meaning ‘lizard’; and its specific name Narmadensis refers to the Narmada River in central India near where it was discovered. Attractive Replication – A replica of the endemic dinosaur with the distinctive horn is created and exhibited for the visitors. The replica is about three times the estimated–original size; it measures 75 feet in length and 25 feet in height. This offers the visitors a glimpse into the evolution of the planet and mankind and is an attempt to create public awareness regarding the wealth of ancient flora and fauna of this area. The positioning of the sculptures is in such a way that one can actually feel the presence of these extinct formidable beasts at this place. It gives you an experience of how life on Earth was like millions of years ago. A nature trail amidst the forests of Vindyachal takes you to the Rajasarus Narmadensis and a treasurable moment to relive the primeval era when these colossal beasts used to roam in the prehistoric woodlands of Narmada valley. Rajasaurus has become a tourist attraction for the state of Gujarat. The continued popularity of dinosaurs as movie monsters has become striking because of films like Jurassic Park and in TV shows. It has therefore captivated attention among the crowd especially the younger generation. Growing charm of Dinosaur toys is another reason for its admiration.
Sections 10.7 - 10.9 Fluid dynamics is the study of how fluids behave when they're in motion. This can get very complicated, so we'll focus on one simple case, but we should briefly mention the different categories of fluid flow. Fluids can flow steadily, or be turbulent. In steady flow, the fluid passing a given point maintains a steady velocity. For turbulent flow, the speed and or the direction of the flow varies. In steady flow, the motion can be represented with streamlines showing the direction the water flows in different areas. The density of the streamlines increases as the velocity increases. Fluids can be compressible or incompressible. This is the big difference between liquids and gases, because liquids are generally incompressible, meaning that they don't change volume much in response to a pressure change; gases are compressible, and will change volume in response to a change in pressure. Fluid can be viscous (pours slowly) or non-viscous (pours easily). Fluid flow can be rotational or irrotational. Irrotational means it travels in straight lines; rotational means it swirls. For most of the rest of the chapter, we'll focus on irrotational, incompressible, steady streamline non-viscous flow. The equation of continuity states that for an incompressible fluid flowing in a tube of varying cross-section, the mass flow rate is the same everywhere in the tube. The mass flow rate is simply the rate at which mass flows past a given point, so it's the total mass flowing past divided by the time interval. The equation of continuity can be reduced to: Generally, the density stays constant and then it's simply the flow rate (Av) that is constant. There are basically two ways to make fluid flow through a pipe. One way is to tilt the pipe so the flow is downhill, in which case gravitational kinetic energy is transformed to kinetic energy. The second way is to make the pressure at one end of the pipe larger than the pressure at the other end. A pressure difference is like a net force, producing acceleration of the fluid. As long as the fluid flow is steady, and the fluid is non-viscous and incompressible, the flow can be looked at from an energy perspective. This is what Bernoulli's equation does, relating the pressure, velocity, and height of a fluid at one point to the same parameters at a second point. The equation is very useful, and can be used to explain such things as how airplanes fly, and how baseballs curve. The pressure, speed, and height (y) at two points in a steady-flowing, non-viscous, incompressible fluid are related by the equation: Some of these terms probably look familiar...the second term on each side looks something like kinetic energy, and the third term looks a lot like gravitational potential energy. If the equation was multiplied through by the volume, the density could be replaced by mass, and the pressure could be replaced by force x distance, which is work. Looked at in that way, the equation makes sense: the difference in pressure does work, which can be used to change the kinetic energy and/or the potential energy of the fluid. Bernoulli's equation has some surprising implications. For our first look at the equation, consider a fluid flowing through a horizontal pipe. The pipe is narrower at one spot than along the rest of the pipe. By applying the continuity equation, the velocity of the fluid is greater in the narrow section. Is the pressure higher or lower in the narrow section, where the velocity increases? Your first inclination might be to say that where the velocity is greatest, the pressure is greatest, because if you stuck your hand in the flow where it's going fastest you'd feel a big force. The force does not come from the pressure there, however; it comes from your hand taking momentum away from the fluid. The pipe is horizontal, so both points are at the same height. Bernoulli's equation can be simplified in this case to: The kinetic energy term on the right is larger than the kinetic energy term on the left, so for the equation to balance the pressure on the right must be smaller than the pressure on the left. It is this pressure difference, in fact, that causes the fluid to flow faster at the place where the pipe narrows. Consider a geyser that shoots water 25 m into the air. How fast is the water traveling when it emerges from the ground? If the water originates in a chamber 35 m below the ground, what is the pressure there? To figure out how fast the water is moving when it comes out of the ground, we could simply use conservation of energy, and set the potential energy of the water 25 m high equal to the kinetic energy the water has when it comes out of the ground. Another way to do it is to apply Bernoulli's equation, which amounts to the same thing as conservation of energy. Let's do it that way, just to convince ourselves that the methods are the same. Bernoulli's equation says: But the pressure at the two points is the same; it's atmospheric pressure at both places. We can measure the potential energy from ground level, so the potential energy term goes away on the left side, and the kinetic energy term is zero on the right hand side. This reduces the equation to: The density cancels out, leaving: This is the same equation we would have found if we'd done it using the chapter 6 conservation of energy method, and canceled out the mass. Solving for velocity gives v = 22.1 m/s. To determine the pressure 35 m below ground, which forces the water up, apply Bernoulli's equation, with point 1 being 35 m below ground, and point 2 being either at ground level, or 25 m above ground. Let's take point 2 to be 25 m above ground, which is 60 m above the chamber where the pressurized water is. We can take the velocity to be zero at both points (the acceleration occurs as the water rises up to ground level, coming from the difference between the chamber pressure and atmospheric pressure). The pressure on the right-hand side is atmospheric pressure, and if we measure heights from the level of the chamber, the height on the left side is zero, and on the right side is 60 m. This gives: Bernoulli's equation can be used to explain why curveballs curve. Let's say the ball is thrown so it spins. As air flows over the ball, the seams of the ball cause the air to slow down a little on one side and speed up a little on the other. The side where the air speed is higher has lower pressure, so the ball is deflected toward that side. To throw a curveball, the rotation of the ball should be around a vertical axis. It's a little more complicated than that, actually. Although the picture here shows nice streamline flow as the air moves left relative to the ball, in reality there is some turbulence. The air does exert a force down on the ball in the figure above, so the ball must exert an upward force on the air. This causes air that travels below the ball in the picture to move up and fill the space left by the ball as it moves by, which reduces drag on the ball.
January 17, 2014 AWJ by the Asahi Shimbun By HIROHIKO NAKAMURA/ Staff Writer Advances in chemical analysis are helping archaeologists to gain a better understanding of what early inhabitants of the Japanese islands were like. In recent years, new hypotheses have emerged from testing of artifacts and amino acids in human remains about the origins of ancient Japanese. By blending conventional archaeological research with the latest advances in chemistry, scientists are slowly unraveling many of these mysteries. A team led by Tokyo University of Science professor Izumi Nakai has developed a special X-ray fluorescence (XRF) analyzer for chemical analysis, which can detect different types of elements and their concentration. Many decorative items, such as glass beads less than 1 centimeter in diameter, have been found in sites dating to Japan’s Yayoi Pottery Culture (300 B.C.-A.D. 300) and in tumuli built during the Kofun Period (third century to seventh century). Glass was not made in Japan at this time, which means the beads came from overseas. But from where is not known. Unlike ordinary glass objects, it is difficult to speculate on the origins of simple glass beads based on their ornamentation or patterns. Nakai’s team hopes to reveal the origin of ancient Japanese glass through chemical analysis. The elemental composition of glass varies, depending on where it is made. Researchers can figure out where glass in ancient Japan was brought from by using an XRF analyzer to compare samples from Japan and elsewhere. Nakai’s team analyzed glass beads excavated from over 100 tumuli and archaeological sites across Japan, as well as cultural properties kept at Todaiji temple in Nara and Byodoin temple’s Phoenix Hall in Kyoto Prefecture. They also examined artifacts from sites in Turkey and Syria as well as Laos, Vietnam and elsewhere. Many beads excavated in western Japan are alumina soda-lime glass, which contains a large amount of aluminum. The results of the analysis showed that even the beads’ trace components closely matched glass found at sites in India and Southeast Asia. Pigments used to color the glass were also of the same type and composition. “We were able to scientifically prove a very high likelihood that ancient glass in Japan was carried from Southeast Asia and South Asia by maritime trade,” Nakai said. “This shows us that ancient people used the maritime Silk Road in addition to the overland Silk Road to carry goods to and from West Asia.” FROM AMINO ACIDS Research is also being done on the eating habits of ancient Japanese by analyzing amino acids taken from human remains and animals excavated at archaeological sites. A University of Tokyo team led by Minoru Yoneda, a professor of isotope ecology, has focused on nitrogen inside amino acids. Through eating, nitrogen is absorbed into the body where it accumulates. The team believes it may be able to figure out eating habits by examining the proportion of nitrogen isotopes N15 and N14 extracted from bones. Yoneda and his team extracted collagen protein from human and animal bones found at the Tochibara rock shelter, a site in Nagano Prefecture that dates to the Jomon Pottery Culture (8000 B.C.-300 B.C.). In the samples extracted, the team examined the proportion of nitrogen isotopes in the amino acids phenylalanine and glutamic acid. Yoneda said the size of the Tochibara rock shelter suggests that it likely housed a large number of people. According to one theory, an enormous quantity of food was needed to feed the community. That could have marked the start of farming in the area because of uncertain supplies of food from hunting. The results of an analysis of the amino acids showed a large divergence in the ratio of nitrogen isotopes between Margaritiferidae, a family of freshwater mussels and mollusks, on one side and humans and land animals on the other. The team said the results indicate that humans relied on land ecosystems for food. Furthermore, the value of the isotopic ratio in humans is nearly the same as that for foxes, which are mainly carnivorous animals, rather than the figure found in largely herbivorous animals such as deer, rabbits and wild boar. This demonstrates that while the humans were omnivorous, they principally consumed meat. The results allow the researchers to estimate that 50 to 70 percent of the protein consumed by humans came from land animals. This finding caused Yoneda to express doubts about conventional theories. “If they primarily lived as farmers, then the figure should be closer to those of herbivores,” he said. “Perhaps agriculture had not developed yet in this region.”
Water is the only common substance on the earth that appears in all three of its natural states within the normal range of its climatic conditions, sometimes at the same time. The three states include liquid, solid, and gas or — water, ice, and water vapor. Most liquids contract steadily as they freeze. Water, however, contracts only a certain amount, but begins to expand as it reaches its freezing point of 0°C (32°F). This expansion can fracture rocks. An unusual characteristic of water is its heat capacity, that is, its ability to absorb heat without becoming extremely hot itself. Think of a swimming pool on a hot day— does the water ever get as hot as the air temperature? Water has a high surface tension, that is, the ability of a substance to stick to itself. Certain light items can float on water and small insects can walk on water. It is estimated that it would take a force of 210,000 pounds to pull apart a column of water 1 inch in diameter. Water has a tremendous ability to stick to surfaces; this is called adhesion. In a very narrow column such as a plant root or stem, the combination of surface tension and adhesion pulls water upward. This movement is known as capillarity. A remarkable property of water is its ability, given enough time, to erode or, wear away, the hardest of rocks. The human body is 66% water. Of the world’s total freshwater supply, over two-thirds is found underground. About 82% of our blood is water. Water helps digest our food, take in oxygen, transport body wastes, and control body temperature. Only 3% of the water found on the earth is freshwater; 97% is salt water, found in the oceans and salty lakes. Only 1% of the earth’s water supply is in a form that is usable by animals, plants, and humans. Water data are often measured in millions of gallons per day (mgd). A million gallons is roughly equal to 20,000 full bathtubs.
Also called hydrolaccoliths, pingos are spectacular domes of earth and vegetation covered ice usually found in the Arctic and subarctic. They can reach up to 90 metres (300 feet) high and more than 800 metres (0.5 mile) across and are usually circular or oval-shaped. They may be green on the outside, but the core is solid, clear ice. Pingos are not easy to understand; they form when the pressure of freezing groundwater pushes up a layer of frozen ground. They can only form in a permafrost environment, where ice freezes and thaws constantly throughout the year. They are essentially formed by ground ice which develops during the winter months as temperatures fall, and they usually grow at a rate of 1-2 centimeters per year. To form entirely, they need decades or even centuries. The core, which often accounts for most of the pingo size, is made of solid ice; the ice in the core originates from the segregation of injection of fluid water. If the overlying material breaks, the ice can become exposed and melt, creating a crater or a lake. Some larger pingos may even have large cones like some volcanoes do, potentially filled by a lake. There are two types of pingos: open-system and closed-system. Open-system pingos form when water flows from an external source – aquifers – in regions of discontinuous or thin permafrost. They often form at the base of slopes. Because they are always under the impact of artesian pressure, they tend to grow more (not because of the pressure directly, but because the ice core that is being fed the water from the aquifer). They are often oval in shape. The surprising thing about these formations is they also form in non-glacial areas, but scientists aren’t sure why. Closed-system pingos, in contrast, form as a result of hydrostatic pressure, where external water sources are not available. The confined mass of saturated soil freezes, pushing the overlying material upward as it expands. They’re often found in the drained lake or river channels or in river deltas. The earliest evidence we have of pingos comes from the Pleistocene Epoch (2.6 million to 11,700 years ago), but they would have likely formed in all periods when the climate was cool enough. Because they form in very specific conditions, they are important climate indicators and can provide valuable information about climate change. Eventually, pingos outgrow their stability (or the underlying system changes or collapses), and they break down. The current estimate is that pingos can last about 1000 years. Tuktoyaktuk in the Mackenzie Delta has one of the highest concentrations of pingos.
- Search Military records Find your ancestors in our military collection - Browse Memory BankRead the stories in the findmypast memory bank - History of Anzac Day Find out more on the origins of Anzac Day - Military History Articles Read articles by Military experts - Boer War Learn more about the Boer War - First World War Learn more about World War I - Second World War Learn more about World War II - Korean War Learn more about the Korean War - Vietnam War Learn more about the Vietnam War - Photos View wartime photos - Videos Watch videos on the wars - Free Digital Magazine Download the findmypast and Inside History Magazine - Ask an Expert Send in your questions for our experts - Blog Read our blog and stay up to date - Inside History Magazine Read about our partner in this project Learn more about the Vietnam War The Vietnam War was a Cold War-era military conflict which occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It is sometimes referred to as the Second Indochina War. In Vietnam it is often referred to as the American War. It was fought between the communist Democratic Republic of Vietnam (North Vietnam) and its allies, and the US-backed Republic of Vietnam in the south. It ended with the defeat of South Vietnam in April 1975. The Viet Cong, a lightly armed South Vietnamese communist common front directed by the North, largely fought a guerrilla war against anti-communist forces in the region. The Vietnam People's Army (North Vietnamese Army) engaged in a more conventional war, at times committing large units into battle. U.S. and South Vietnamese forces relied on air superiority and overwhelming firepower to conduct search and destroy operations, involving ground forces, artillery, and airstrikes. Photo at right shows the evacuation of a wounded Korean infantryman by American medical evacuation iroquois helicopter. The U.S. government viewed involvement in the war as a way to prevent a communist takeover of South Vietnam as part of their wider strategy of containment. The North Vietnamese government and Viet Cong viewed the conflict as a colonial war, fought initially against France, backed by the U.S., and later against South Vietnam. American military advisors arrived in what was then French Indochina beginning in 1950. U.S. involvement escalated in the early 1960s, with troop levels tripling in 1961 and tripling again in 1962. U.S. combat units began being deployed in 1965. Operations covered international borders, with Laos and Cambodia heavily bombed. American involvement in the war peaked in 1968, at the time of the Tet Offensive. After this, U.S. ground forces were gradually withdrawn as part of a policy known as Vietnamization. Despite the Paris Peace Accords, signed by all parties in January 1973, fighting continued. By 1969, at the peak of U.S. involvement in the war, more than 500,000 U.S. military personnel were involved in the Vietnam conflict. Growing opposition to the war in the United States led to bitter divisions among Americans, both before and after President Richard Nixon ordered the withdrawal of U.S. forces in 1973. In 1975, communist forces seized control of Saigon, ending the Vietnam War, and the country was unified as the Socialist Republic of Vietnam the following year. U.S. military involvement ended on 15 August 1973 as a result of the Case--Church Amendment passed by the U.S. Congress. The capture of Saigon by the Vietnam People's Army in April 1975 marked the end of the war, and North and South Vietnam were reunified the following year. The war exacted a huge human cost in terms of fatalities. Estimates of the number of Vietnamese soldiers and civilians killed vary from 800,000to 3.1 million. Some 200,000--300,000 Cambodians, 20,000--200,000 Laotians, and 58,220 U.S. service members also died in the conflict. The Vietnam War was the longest and most unpopular conflict of the century for both Australia and New Zealand. The war was the cause of the greatest social and political dissent in Australia since the conscription referendums of the First World War. Many draft resisters, conscientious objectors, and protesters were fined or jailed, while some soldiers met a hostile reception on their return home. Photo at right shows South Vietnamese soldiers take a break following heavy fighting in the Tan Son Nhut area near Saigon airport. Did you know? - The Vietnam War is one of the longest military engagements in recent history. The conflict raged on for nearly 20 years, November 1, 1955 to the Fall of Saigon on April 30, 1975 - About 7,500 women served in the Vietnam war - There were approximately over 3 million killed in the Vietnam war and more than half were civilians - Five men that were killed were only 16 years old! - The oldest man killed was 62 years old! - 91% of Vietnam vets were glad that they served - 74% of the vets would serve again knowing the outcome - Congress never declared war against Vietnam, so it should be called the Vietnam conflict, which it commonly is - The U.S. didn't lose the war but withdrew before they lost - The average fighter was only 22 years old! - 66% of the soldiers were drafted - During the Vietnam War the national debt increased by $146 billion (1967-1973). Adjusted for inflation, the debt in 1992 dollars was $500 billion - April 30 is celebrated as Reunification Day or Victory Day in Vietnam
Rapid climate change—such as recent changes in climate that are occurring more rapidly than at any time since the last glacial maximum—presents two particularly formidable challenges for national parks and society in general. First, we must improve our understanding of the effects of climate change and how to manage them. Second, we must communicate the science of climate change in a concrete, noncontroversial (or minimally controversial) way that promotes understanding and action. In the National Park Service (NPS), many efforts are under way to address these two challenges (http://www.nps.gov/climatechange). Here, we describe one promising approach that addresses both challenges simultaneously: studying climate-driven changes in phenology—the timing of seasonal biological events, such as flowering and migrations. Phenology has played an important role in the lives of people, plants, and animals through history. Human subsistence has depended on knowing when food plants are available and when game species arrive or depart on migrations. Much of ecological theory and many of our management practices recognized this, but assumed that phenology was relatively stable from one year to the next, in part because climate, which drives the timing of many phenological events, was long thought to be fairly stable, or “stationary” (Milly et al. 2008). In a period of rapid climate change, though, understanding phenology becomes even more important. Almost every ecological relationship and process—including predator-prey and plant-pollinator interactions, the spread of disease, pest outbreaks, and water and carbon cycling—depends on the timing of phenological events (Forrest and Miller-Rushing 2010). As climatic conditions change, phenology changes, and so do these ecological relationships and processes. These shifts are further complicated because the phenologies of different species change at different rates and in different directions, some occurring earlier, others later (Sherry et al. 2007; Thackeray et al. 2010). In some cases this may lead to mismatches, as has occurred in parts of Europe where pied flycatchers (Ficedula hypoleuca) are now breeding too late relative to when their primary food source, winter moth caterpillars, is available; where this mismatch is most severe, populations of pied flycatchers are declining by up to 90% (Both et al. 2006). Changes in phenology also vary across space, as is evident in the earlier-than-average spring green-up and flowering of most plants in the northern United States, but later in southern regions (Zhang et al. 2007; Von Holle et al. 2010). Right now we are ill-equipped to predict the impacts of phenological changes on species and ecosystems because of a dearth of data describing the phenology of most species and the role of timing in regulating species interactions and ecological processes. In addition to its role in ecosystem functions, phenology provides one of the most fundamental ways people relate to nature. Phenological events mark the changing of seasons: the emergence of leaves and butterflies and the sounds and activities of birds, frogs, and other animals herald the arrival of spring; fall foliage and crop harvest mark the onset of autumn and winter in much of the country. Because phenology is tightly coupled with climate and is changing wherever climate is changing, it provides a way that people can “see” climate change and its impacts wherever they are.
Are you a freshman? You can easily learn tips that will help you stay ahead. You will be a step further than many of your classmates. Study skills are an ordered set of actions taken by the student to achieve understanding and memorizing concepts, principles or facts permanently. Many students who get good academic results, have been able to establish the most effective strategies. Regular use of these strategies allows the student to better leverage his/her experience, not only about intellectual resources and, therefore, improve his/her academic performance. The study technique is an essential learning strategy in the educational process of young people today. Far from going out of style, it is a necessary activity to complement other learning activities such as project development, exchange and contrasting opinions or carrying out enforcement activities. Studying means to relate the new with the integrated knowledge and to remember it at the right time, that is, understand it and memorize it permanently. Study skills are part of the learning strategies that can be grouped into three groups: organizational strategies, strategies for classroom work and study and memorization of information. Organizational strategies may allow you to create an order in aneffective manner. Strategies for classroom work are those that make their class work more useful. The techniques of study and memorization of the information is to understand and remember concepts, principles, or facts permanently. As with other learning strategies, some freshman need specific training in such techniques to improve their effectiveness as students. Others, however, do so alone. Study techniques cannot be learned as an isolated learning, but their training is carried out using the guidance note set out below, as they study classroom content. Studying is a process that requires four stages: - Text comprehension. - Selecting and organizing concepts, so that the amount of information is smaller and therefore easier to learn. - Memorization of key concepts. - Evocation of the study. Read-Ahead. This is great in order to make a very quick read about everything that you are supposed to study to get a general idea about the content of the text. Teacher will be impressed! They will have nothing to complain about. Main memory concept Visualization of the scheme. To memorize the layout of keys made, you will need to look closely for a time, two to five minutes depending on the size of the scheme, showing attention to the number of elements in each level, positioned at different levels. There are few…, that is, observing with attention to detail. After trying to cover up the scheme and play on paper. If replicated successfully move to the next phase. Otherwise, repeat the process. Repeated recitation of the abstract. First, you have to divide the abstracts into small parts to study them separately, one after another. It can be done with questions or paragraphs. It is then being read three times, orally or silently, the first of the separate parts, after which it will clog it and try to read again without looking. Then you need to check and, if achieved, do the same with the second part. If not, re-read three times and again to check. You can be a freshman with extensive knowledge! Are you ready to be the top freshman ever? Are you willing to invest time mastering studying skills?
Spring means severe weather and increased concern for natural disasters like tornadoes, hurricanes, wildfires and earthquakes. Here are free printable weather science lesson plans on natural disasters, fire safety, emergency preparedness and other severe weather issues. NOAA, the National Atmospheric and Oceanic Administration, has free printable severe weather science lesson plans. Print materials from the NWS (National Weather Service) and the Red Cross. There is a series of free printable severe weather science booklets from the Red Cross on Owlie Skywarn, an owl who teaches children about different kinds of weather. Owlie covers thunder storms, tornadoes, lightning, floods, hurricanes and winter storms. The booklet is 44 pages long and contains free printable coloring pages. Learn about severe weather with Billy and Maria. These children explore storms, lightning, hurricanes, fire safety and emergency preparedness in free printablesevere weather coloring pages, puzzles, word searches and weather experiments. NOAA has a free printable booklet about the tsunamis and earthquakes with Tommy Tsunami and Ernie Earthquake. It explores the relationship between the two phenomena. This booklet is 15 pages long and has several activities for weather science units. There is a free printable guide to make a weather satellite, too. Ready.gov is the homepage for free printable emergency safety kids activities from FEMA, the Federal Emergency Management Administration. Children can follow Herman the hermit crab as he teaches children about emergency preparedness, weather science, natural disasters, This site helps children create emergency safety response plans. Spring severe weather science is also concerned with wildfires which are sparked by droughts. October is offical Fire Prevention month. You could follow up weather science units with science lessons on wildfires and fire safety. Visit Sparky.for free printable fire safety and emergency safety games, coloring pages and activities about fire prevention. Over 75 years ago, a little bear was discovered wandering alone after wildfires, then called a forest fires, took his home. He was namedSmokey Bear and he became the voice for forest rangers and fire prevention. Get free printable fire emergency safety help there too. Ready.gov is a natural disasters emergency preparedness website maintained by FEMA with free printable severe weather resources, lesson plans, emergency planning kits and lots of resources. Ready.gov teaches students about natural disasters and weather-related emergency safety. You'll find lesson plans and activities for wildfires, hurricanes, tornadoes, storm safety, floods, blizzards, droughts and more. The focus of the website is two-pronged: Make an Emergency Plan and Get a Kit. Ready.gov provides printable checklists to prepare for disaster. Children might read The Big Wave by Pearl S. Buck to learn more about tidal waves (now called tsunamis). The Big Wave is a 1948 story of a Japanese family's experiences following a tsunami. After the 2004 tsunami, Scholastic Books made copies of this book available at reduced rates, to help children understand the event.This books explains floods and hurricane storm surges like the one that drowned New Orleans and much of the gulf coast in Hurricane Katrina of 2005.
What’s alopecia and what can you do about it? Hair loss can be stressful and alienating. Knowing the different types and causes of hair loss can help to clarify the unknown and make a stressful situation a little more manageable. A burn is damage to your body's tissues caused by heat, chemicals, electricity, sunlight or radiation. Scalds from hot liquids and steam, building fires and flammable liquids and gases are the most common causes of burns. Another kind is an inhalation injury, caused by breathing smoke. There are three types of burns: Burns can cause swelling, blistering, scarring and, in serious cases, shock and even death. They also can lead to infections because they damage your skin's protective barrier. Antibiotic creams can prevent or treat infections. After a third-degree burn, you need skin or synthetic grafts to cover exposed tissue and encourage new skin to grow. First- and second-degree burns usually heal without grafts. All burns need to be evaluated by a specialist trained in the treatment of burns to provide patients with the best possible outcome. The Ohio State Comprehensive Burn Center is the only adult burn center in central Ohio verified by the American College of Surgeons and the American Burn Association. Source: National Institutes of Health: National Institute of General Medical Sciences Get tips from Ohio State experts right to your inbox.
One of the most famous works in the history of international law is Hugo Grotius' Mare Liberum from the beginning of the 17th Century. The entire discipline of international law is arguably founded on this, and dissertations like it, dealing with the legal peculiarities regarding situations with vessels from different countries on the high seas. “Mare Liberum” is literally “Free Sea” in English, that is, an area outside the territory of any state and thereby free from states' jurisdiction, and Grotius believed the high seas were just that. States begged to differ, naturally, and through the years they tried to extend their territorial sovereignty from land as far as possible in to the seas and oceans. In the 20th Century the technological advances that made the exploitation of the natural resources of the seas and the ocean floor much more efficient only increased the coastal states' desire to gain absolute control. The situation needed regulating, and so far, the most significant word in the delimitation of maritime zones was written in 1982 when, after nine long years of deliberation, the United Nations Convention on the Law of the Sea (CLS) was finally (almost) complete. This convention is by many considered a constitution of the law of the sea. The convention's definition of the different maritime zones is the most extensive in any one treaty. The baselines are the starting point from where all other zones are measured. These are usually the low water line along the coasts. There is a tradition of using straight lines across fjords and bays, but there are no established standards for this practice. Also, archipelagos may draw straight lines joining the outermost islands, within reason. The internal waters The internal waters lies between the baseline and the coastline. This includes rivers and their mouths, canals and harbors, and of course lakes. When straight baselines have been used, quite considerable areas of water close to a state may be internal waters (especially in the case of archipelagic waters). Internal waters is treated like land territory and the coastal state has complete jurisdiction and absolute territorial sovereignty. The territorial sea Extending outwards from the baseline is the territorial waters. In the old days, the breadth of this belt was as long as a cannonball could reach, fired from the shore. In the 19th Century 3–4 nautical miles was one norm, but many countries extended on this for reasons of economy (fishing) or national security. The CLS set the maximum range to 12 mi. As was the case with a coastal state's internal waters, terriotorial sea is treated like land territory, but with the exception that foreign vessels (ships, not airplanes) have the right to “innocent passage”, that is, peaceful navigation through the waters. Such passage must be “continuous and expedititious” and submarines must remain surfaced. The right to innocent passage, as given by the CLS, includes some protection from the jurisdiction of the coastal state, and only if the following conditions are met can the crew be arrested or the ship inspected: - “if the consequences of the crime extend to the coastal State; - if the crime is of a kind to disturb the peace of the country or the good order of the territorial sea; - if the assistance of the local authorities has been requested by the master of the ship or by diplomatic agent or consular officer of the flag State; or - if such measures are necessary for the suppression of illicit traffic in narcotic drugs or psychothropic substances” Whether warships can claim innocent passage is contested. United States believe they can, China believe they can't. Special rules govern international straits such as those of Dover, Hormuz or Gibraltar. For these straits vessels' rights to safe passage are reinforced. And not only does the right to transit passage unambigiously cover warships (even submarines may remain submerged) it also covers airplanes as this was a condition for several states before agreeing to a 12 mi territorial belt. Some straits (e.g. Bosporus) have individual treaties governing their use. As do man-made canals like Suez and Panama. The high seas If an area is outside both the territorial or internal waters of any coastal state and its exclusive economic zone (see below) it is considered high sea. The high seas are fundamentally free, and the vessels travel only under the jurisdiction of their flag state. The freedom of the high seas comprises - freedom of navigation - freedom of overflight - freedom to lay submarine cables and pipelines… - freedom to construct artificial islands and other installations permitted under international law… - freedom of fishing… - freedom of scientific resarch… The list is from the CLS, slightly truncated as it refers to articles of further regulation of these areas in the convention, but the basic principle remains that any state (coastal or inland) and its vessels are free to do as they please on the high seas as long as they do it peacefully and without restricting other states in doing the same. The one major exception to these rules is piracy and slave trade. Pirates and slave traders is under the jurisdiction of any nation, and warships may board such vessels. Near coastal waters, there might be a few further restrictions on the freedom of the high seas, as described below: The contiguous zone The contiguous zone borders the territorial seas of a coastal state and extends no longer than 24 mi from the baselines. While it is technically in the high seas, the zone gives the coastal state jurisdiciton in cases concerning immigration, sanitation, taxes or customs if the crimes have been committed inside the territory of the coastal state. Thus, the contiguous zone gives states a better chance to catch fleeing vessels. Even if the culprit manages to escape from the contiguous zone the coastal state may continue the chase if it is engaged in “hot pursuit” and this chase is not interrupted. If the culprit sails into another state's territorial waters the chase has to be called off, hot pursuit or not. The exclusive economic zone (EEZ) Since the 1960es coastal states have laid claim to special fishing zones exclusive to those states. Acceptance of such claims conflict with the freedom of the seas, but it became customary to accept exclusive fishing zones to an extent of 12 mi from the baselines, nonetheless. This escalated into claims of what was now known as exclusive economic zones to an extent of up to 200 mi from the baselines, and these claims were eventually accepted as well. In the EEZ, the states have “sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superjacent to the sea-bed and of the sea-bed and its subsoil, and with regard to other activities for the economic exploitation and exploration of the zone, such as the production of energy from the water, currents and winds” The coastal state is also given the jurisdiction to uphold these rights. In all other aspects, the rules and freedoms of the high seas prevail. The continental shelf This is the seabed and subsoil to the extent of no less than 200 mi from the baselines (which makes the area co-extensive with the EEZ) and up to 350 mi, or, alternatively, up to 100 mi from the 2.5 kilometers isobath. If a coastal state lays claim to the continental shelf in extent of over 200 mi they have to pay an annual fee to the International Seabed Authority. In this area the coastal state has sovereign rights to explore and exploit the natural resources of the sea-bed and subsoil, not the sea above it (unless, of course, the sea above it is in the coastal state's EEZ). The sea-bed and ocean floor and subsoil thereof This area has been the most controversial. In 1970 the United Nation's General Assembly announced that “The sea-bed and ocean-floor, and the subsoul thereof, beyond the limits of national jurisdiction (hereinafter referred to the area), as well as the resources of the area, are the common heritage of mankind.” The idea was that third world states and, explicitly, “mankind as a whole” should be given an opportunity to take part in the exploitation of the natural resources of the sea. In the convention of 1982 this was the last unresolved issue. The idea was to give all rights to this, the area, to the International Seabed Authority (ISA). The ISA would then either exploit it themselves or sell concessions. This was unacceptable to most industrial countries and many of them (notably United States and the Soviet Union) instead created national laws governing authorizations to exploit the area. However, ultimately nobody was interested in the costly exploitation of the area, and in 1994 a compromise was reached that liberalized the acces to the area while retaining the system of licenses and fees to the ISA. (This is part of my personal quest (study) on international and humanitarian law)
Definition of Cumulative Sentence A cumulative sentence is known as a “loose sentence,” that starts with an independent clause or main clause, which is simple and straight, provides main idea, and then adds subordinate elements or modifiers. It adds subordinate or modifying elements after the subject and the predicate. Writers use these types of sentences when they want to put forth the main idea first, and provide details to elucidate the idea further thereafter. They use these details in the form of dependent or subordinate phrases or clauses. These types of sentences work better in various forms of writing, specifically in explaining theories, by giving the main idea at the beginning, and then adding more information to build up the idea further. For instance, in the sentence, “Llanblethian hangs pleasantly, with its white cottages, and orchard and other trees…” (The Life of John Sterling, by Thomas Carlyle), the main clause is short, independent, and straightforward, while the subordinate elements clarify the idea further. Examples of Cumulative Sentence in Literature Example #1: More Die of Heartbreak (by Saul Bellow) “The radiators put out lots of heat, too much, in fact, and old-fashioned sounds and smells came with it, exhalations of the matter that composes our own mortality, and reminiscent of the intimate gases we all diffuse.” In these lines, the main idea is simply the heat of radiators. After that, comes additional information, telling how dangerous the smell of these radiators could be for the humans. Example #2: Some Dreamers of the Golden Dream (by Joan Didion) “The San Bernardino Valley lies only an hour east of Los Angeles by the San Bernardino Freeway but is in certain ways an alien place: not the coastal California of the subtropical twilights and the soft westerlies off the Pacific but a harsher California, haunted by the Mojave just beyond the mountains, devastated by the hot dry Santa Ana wind that comes down through the passes at 100 miles an hour and whines through the eucalyptus windbreaks and works on the nerves.” Example #3: Life and Times of Chaucer (by John Gardner) “The unwieldy provision carts, draught horses, and heavily armed knights kept the advance down to nine miles a day, the huge horde moving in three parallel columns, cutting broad highways of litter and devastation through an already abandoned countryside, many of the adventurers now traveling on foot, having sold their horses for bread or having slaughtered them for meat.” This is a perfect description of a cumulative sentence. The main clause is about carts, and then there are further details that explain how carts move down the road. Example #4: Gentlemen of the Road: A Tale of Adventure (by Michael Chabon) “He wept silently, after the custom of shamed and angry men, so that when the pursuit party came tumbling, pounding, scrabbling down the trail, past the fold in which he and Hillel stood concealed, he could hear the creak and rattle of their leather armor with its scales of horn; and when the Arsiyah returned, just before daybreak, at the very hour when all of creation seemed to fall silent as if fighting off tears, Zelikman could hear the rumbling of the men’s bellies and the grit in their eyelids and the hollowness of failure sounding in their chests.” This is another very good example of cumulative sentence. The main clause is very short and straight, telling someone has wept; thereafter, the author has given a detailed description of why someone, mentioned in the main clause, wept silently. Function of Cumulative Sentence Cumulative sentences are easier to understand, straightforward, and simple. The additional details in these sentences become relatively important, as they elucidate the main idea, given in a few words at the beginning. They are useful when the goal of a writer is clarity rather than suspense. Cumulative sentences give an informal, conversational, and relaxed feeling to a work of art. Besides, one must be judicious while explaining a main clause through subordinate and modifying phrases or clauses. At times, readers might not read full details in the entire sentence, as they have already read the main idea. Moreover, if a sentence becomes too long, they might lose interest, or forget the main idea at the end of a sentence.
The scanning electron microscope (SEM) is one of the most adaptable accessories available for examining and dissecting the morphological properties of microstructure and substance composition. The fundamental scanning electron microscope principle needs to be known in order to understand the basics of the electron microscope. The eye is actually able to distinguish objects having an angle of view of about 1/60 °, which corresponds to a resolution of ~ 0.1 mm (with an optimal viewing distance of 25 cm). Scanning electron microscope resolution has a limit of ~ 2000 Å by increasing the viewing angle through the optical lens. Light microscopy was and is very important for research. Since the discovery that electrons can deviate from magnetic fields in various experiments in the 1890s, electron microscopes have been developed by replacing light sources with high-energy electron beams. Things You Should Know for Scanning Electron Microscope Scanning electron microscopy (SEM) reflects a focused electron beam on a surface to create an image. The electrons in the beam interact with the sample and generate a variety of signals that can be used to obtain information about surface topography and composition. If there is enough light, the human eye can distinguish two points 0.2mm from each other without an additional lens. This distance is called the dissolution or dissolution of the eye. The scanning and transmission electron microscopy can be used to increase this distance and allow the eye to see a point even closer than 0.2 mm away. Modern light microscopes have a maximum magnification of about 1000x. The resolution of a microscope is limited not only by the number and quality of lenses but also by the wavelength of light used for illumination. White light has a wavelength from 400 to 700 nanometers (nm). The average wavelength is 550 nm, which leads to a limit of the theoretical resolution (no visibility) of light microscopy in the white light of about 200 to 250 nm. The need for an used scanning electron microscope was developed when wavelength became the limiting factor in light microscopy. Electrons have a much shorter wavelength, which allows for better resolution. Difference Between Optical and Scanning Electron Microscope As the dimensions of the material and device have shrunk, many structures can no longer be characterized by light microscopy. For example, to determine the integrity of the nanofiber filter layer shown here, an electron microscope is required to characterize the sample. The chief scanning and transmission electron microscopy parts include: - Source of electrons - The gap through which electrons move with an electromagnetic lens - Electronic detectors - Sample room - Computer and screen for viewing pictures At the top of the string, electrons are generated, accelerated downward, and passed through a combination of lenses and holes to create a focused electron beam hitting the surface of the sample. The sample is mounted on a table in an area of the room. Unless the microscope is designed to operate at a low vacuum, the column and chamber are evacuated by a pump combination. The degree of vacuum depends on the scanning electron microscope principle. The position of the electron beam on the sample is controlled by a scanner coil which is located above the objective lens. With this winding, the block can be scanned on the sample surface. These ray scans, or scans, as the name microscope suggests, allow information to be gathered about a specific area of the sample. A number of signals are received as a result of the electron probe interaction and scanning electron microscope resolution. These signals are then recorded by a suitable detector. Elastic scattering is the result of the deflection of electrons coming from the nucleus of the sample or from the outer shell electrons with the same energy. This type of interaction is characterized by a slight loss of energy during the collision and a wide-angle change in the direction of the scattered electrons. If you are wondering how much is an electron microscope cost? Then the answer is not definite. Incoming electrons that are scattered elastically at an angle of more than 90 ° are known as back-scattering electrons (BSE) and provide a useful signal to represent the sample. Inelastic scattering occurs through various interactions between the incoming electrons and the sample electrons and atoms and causes the primary electrons to transfer significant energy to these atoms. The amount of energy lost depending on whether the sample of electrons is excited individually or together and on the binding energy of electrons to atoms. As a result, the excitation of sample electrons during ionization of the sample atoms leads to the formation of secondary electrons (SE), which generally have an energy of less than 50 eV and can be used to sample or analyze electrons at random. In addition to the signals, the environmental scanning electron microscope further generates the image, a number of other signals are generated when the electron beam enters the sample, including the characteristic X-ray emission, Auger electrons, and cathodoluminescence.
This is a set of 15 different reading passages with comprehension questions perfect for first grade homework or assessment. Each page includes a short text in a large, easy-to-read font, followed by three comprehension questions. Two are multiple choice and the third is a short response. Students are prompted to read each passage three times and color in a smiley face each time they read it before answering the questions. Multiple choice questions have two possible answer choices with large “bubble” circles for students to color in to indicate their answer. Great practice for standardized testing. Each page is provided in two versions: - Version A - Includes space for parent initials to use as homework - Version B - Includes space for a score/grade to use as classwork or assessment First Grade Reading Comprehension RL.1.1, RL.1.3, RI.1.1, RI.1.10, RF.1.4, RF.1.4a ✪ "I homeschool my first grader and I bought this for her to do everyday. She LOVES it! She loves to color the faces in as she reads the passage each time, and she loves to see her score at the end. Thank you for such an awesome resource!" - Buyer ✪ "Thank you. I've been looking for comprehension stories to pick up where my kinders need a challenge. This does a good job, and they have to answer the questions and highlight where they find the answers in the text. Kindergarteners can do so many things people don't think they can do. Thank you." - Elizabeth
A parasitic infection occurs following the invasion of a parasite, an organism that lives and thrives on or inside a host organism. The parasite often survives at the expense of the host. The most common transmission methods for parasites are blood, feces, contaminated food and water, and insects. The prevalence and prognosis of parasitic infections vary by type and depends on several factors, including geographical region and access to adequate medical care. Experts believe more than 200 million people have malaria. The Plasmodium parasite, protozoa, is transmitted through the blood by the bite of an infected mosquito. The vast majority of cases of malaria exist in sub-Saharan Africa. Malaria presents with fever and chills and, if not treated, can lead to anemia, cerebral malaria, organ failure, and death. This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.
Sending Requests Using HTTP HTTP or Hypertext Transfer Protocol is the main protocol of the World Wide Web. When you request a web page by typing its address into your web browser, that request is sent using HTTP. The browser is an HTTP client, and the web page server is (unsurprisingly) an HTTP server. In essence, HTTP defines a set of rules regarding how messages and other data should be formatted and exchanged between servers and browsers. Why Do I Need To Know About This? Ajax sends server requests using the HTTP protocol. It's important to recognize the different types of HTTP requests and the responses that the server may return. Ajax applications need to construct HTTP requests to query the server and will base decisions about what to do next on the content of HTTP responses from the server. What Is (and Isn't) Covered in This Lesson It would be possible to fill the whole book with information on the HTTP protocol, but here we simply discuss it in terms of its roles in requesting web pages and passing information between them. In this lesson you'll look at the construction of HTTP requests and responses and see how HTML forms use such requests to transfer data between web pages.
STRUCTURE AND FUNCTION OF HEART STRUCTURE AND FUNCTION OF HEART – The heart is the major and specialized organ of the blood circulation system. It is made up of cardiac muscles. Its size is the size of its own closed fist, on average, it is about 12 cm in length and 9 cm in width, it weighs about 250 grams to 390 grams in adult males and between 200 and 275 grams in adult females. The heart beats approx 72 times in a minute and 1 lakhs times in a day. The study of heart-related diseases is called cardiology. The hormone which stimulates the heartbeat of the heart is thyroxin. CARDIAC CYCLE plays important role in the functioning of the heart. The structure of the heart is made more complicated because it is the mechanism that allows blood to be distributed throughout the body in sufficient amounts and return to the heart. This continuous process is accomplished with the help of two blood vessels: veins and arteries. The arteries that carry oxygen-rich blood from the heart and to other parts of the body are called arteries and the vessels which bring deoxygenated blood back to the heart are called veins. LOCATION OF HEART The heart is situated in the thoracic cavity between the lungs within the mediastinum. [Structure and function of heart] It is a muscular, hollow, contractile, conical organ that is located behind the sternum with a portion of the middle tissue of both lungs called the mediastinum, and some obliquely on the left side. Due to some being on the left side, one-third of it is situated from the midline of the body to the right side and two-third part is located on the left side. The upper part of the heart is slightly wider, which is called the base, and is tilted to some right. The base is directed superiorly and slightly posterior. The lower point is called the apex which is slightly to the left and slightly forward and rests on the diaphragm. The APEX boundary reaches the intercostals between the fifth and sixth left ribs. Keeping a hand in this place gives the impression of a heartbeat. It is important to know the location of the heart placing a stethoscope to hear the heart sound [lub-dub], placing an electrode on the chest to record an electrocardiogram [ECG], and performing cardiopulmonary resuscitation [CPR] depend on a knowledge of the heart position. LAYERS OF HEART WALL Basically, there are three layers of tissues in the heart wall. The outermost layers called PERICARDIUM, the middle layer of the heart wall is called MYOCARDIUM, and the inner layer is called ENDOCARDIUM. The pericardium is the outermost layer of the heart. The pericardium or cardiovascular is made up of two sacs. The outer sac is made up of fibrous tissues and is in continuity with the double layer of the serous membrane from the inside. In the external fibroid, the sac remains in continuity with tunica adventitia of the large heart vessels above and adjacent to the diaphragm at the bottom. Being fibrous and inelastic in nature, it prevents excessive dilation of the heart.[Structure and function of heart] - The outer layer of the serous membrane covers the fibrous corpus of the parietal pericardium. - The inner layer, the visceral pericardium or EPICARDIUM that is in continuation of the parietal pericardium, is affixed to the heart muscle. The serous membrane consists of flat epithelial cells. It releases a serous fluid into the space between the visceral and parietal layers which prevents friction between the two layers during the heart pulse, which keeps the heart functioning freely. The myocardium is the middle layer of the heart. The myocardium is made up of cardiac muscle fibers or cardiac myocytes. It contains special types of fibers which belong to the involuntary class. The thickness of the myocardium varies; it is thickest at the apex and becomes thinner towards the base. The left ventricle remains thicker because it has to do more work, in the same right ventricle, this layer is thinner because it only has to flow blood to the lungs. This layer is very thin in the atrium. The myocardium is consist of three muscle fibers:- - Fiber helps in the formation of the contractile unit of the heart - fiber which helps in the formation of pacemaker - fiber which helps in the formation of a conductive system of the heart The endocardium is the innermost layer of the human heart. The Endocardium is a thin, smooth, shimmering soft membrane within the heart. It is made up of flat epithelial cells that merge with the endothelium in the internal levels of the blood vessels by being continuous. The Endocardium is covered with all the four chambers and valves of the heart. CHAMBERS OF THE HEART The septum divides the heart lengthwise, and valves divide it crosswise. Each side of the heart thus has two chambers, one above the other. A thin membrane called the Endocardium lines each chamber. [Structure and function of heart] The entire right side of the heart deals with the exchange of impure blood and the left side deals with the exchange of pure blood. Both the right and left parts are again divided by a transverse septum, forming an upward and downward chamber. In this way, the entire internal cavity of the heart is divided into 4 chambers: - Right atrium - Right ventricle - Left atrium - Left ventricle Both the atrium and ventricle on the left and the right side are connected by a hole. Valves are attached to these holes, the valves between the two chambers are in such a way that blood can only go from the atrium to the ventricle, but cannot return. In this chamber, the deoxygenated blood returning from the body is stored in the entire body. Veins coming from different parts of the body are made up of two large veins, the superior vena cava [from the upper part of the body] and the inferior vena cava [from the lower part of the body], which come into the right atrium and opens separately. The right atrium only accepts blood, and the work of pumping blood has little to do, so its contraction is relatively low, that’s why its walls [membrane] relatively thin and weak. After receiving the blood, it has to push the blood so much that it opens the tricuspid valve and goes into the ventricle. Impure blood from the right atrium flows into the right ventricle via the right interventricular orifice. The contraction of the right atrium pushes blood, causing the tricuspid valve sutures to open themselves and impure blood to enter the ventricle. The second moment there is a contraction in the right ventricle, as a result of which the blood is pushed to drain out. The right ventricle has a hole called a pulmonary orifice.[Structure and function of heart] Through this, the pulmonary artery emerges, which later goes out of the heart and divides into two parts and goes to the right and left lungs. As soon as there is a contraction in the right ventricle, impure blood goes through it to be purified into the lungs. As blood enters the pulmonary artery from the ventricle, the pulmonary valve between them closes and impure blood cannot return to the ventricle. The ventricle walls are thicker and stronger than the right atrium because it has to be compressed more than the right atrium to pump blood so that it can reach the lungs to be purified. The upper chamber of the left side of the heart is called the left atrium. It is smaller than the right atrium. Its walls are thicker than the right atrium. In this, two of the four pulmonary veins come from the right pleura [LUNGS] and two from the left pleura [LUNGS] through four holes and bring pure oxygenated blood to the left atrium. The lower chamber of the left part of the heart is the largest chamber and its reefs are also thicker than the reefs of all other chambers. It has a hole called an aortic orifice. Through this, the aorta carries blood to different parts of the body. As a result of the contraction of the left atrium, purified blood fills the left ventricle. The second moment comes to the contraction of the left ventricle. Before this, the mitral valve between the left atrium and the ventricle is closed. On narrowing of the left ventricle, the purified blood opens the aorta’s door with a push and blood comes out of it. There are also valves on the aortic mouth that prevent the blood flow from returning. In this way, the left ventricle performs the most important function of providing nutrients and oxygen to the tissues in the body and also carrying the blood to the body. Structure and function of the heart There are valves in the heart to prevent the backward flow of blood. - TRICUSPID VALVE: positioned between the right atrium and right ventricle - PULMONARY VALVE: positioned between the right ventricle and pulmonary artery - MITRAL VALVE: positioned between the left atrium and the left ventricle - AORTIC VALVE: positioned between the left ventricle and aorta STRUCTURE AND FUNCTION OF HEART Pumping blood to the lungs Blood from the body that enters the right side of the heart contains carbon dioxide, a gaseous waste the cells produced in generating energy. Blood comes in the right Atrium through the superior-inferior Vena cava. The Atrium fills the blood and then contract, forcing the blood through the tricuspid valve into the right ventricle. After the ventricle is filled, the pressure pushes the tricuspid and valve to close, and the pulmonary valve, leading to the Pulmonary artery, to open, the ventricle contracts and the blood through the Pulmonary artery and into the lungs. In the lungs, through the exchange of gases carbon dioxide is removed from the blood, and oxygen is added in the blood. The oxygenated blood then flows through the pulmonary veins to the left side of the heart. Pumping blood throughout the body Oxygenated blood from the lungs enters and fills the Atrium. The Atrium then contracts which squeezes the blood through the mitral/ bicuspid valve into the left ventricle, after blood fills the ventricle, the mitral valve closes and the aortic valve opens. Blood pours into the aorta and flows through arteries to the body tissues. Regulating blood pressure Blood in the circulatory system like water in the pipes of the water system is always under pressure. Blood pressure refers to the force with which the blood pushes against the walls of the arteries. That force drives blood from the heart to all parts of the body. Structure and function of heart- Each person’s blood pressure reflects the amount of blood in the body, the strength and rate of the heart contraction, and the elasticity of the arteries. As the heart pump in cycles, pressure in the arteries Rises and Falls during systole and diastole. Contraction of the heart produces systolic blood pressure, and relaxation produced diastolic blood pressure. The heart helps regulate blood pressure by producing a hormone that helps the kidney in eliminating Salt from the body. Excess salt may contribute to high blood pressure, which is called hypertension. Hypertension can injure the heart, brain, and Kidneys. Regulating the heart rate Both sides of the heart pump blood at the same time. As the right ventricle contract and send blood to the lungs, the left ventricle contract and screws blood out to the body. The heart cycle of activity has two periods, systolic and diastolic. Systolic occurs when the ventricle contract, and diastole when they relax. One complete contraction and relaxation of the heart muscle make up one heartbeat. Structure and function of heart READ MORE ABOUT- Structure and function of skin
8th grade reading comprehension worksheets 8th grade reading comprehension worksheets.1602814200 Comprehension is the foundation of all education. Reading is an essential skill that students need to gain to develop as citizens in a modern society. Comprehension becomes important as students advance from primary school to junior high school, through high school, and on into post-graduate studies. Reading comprehension tests are one way to evaluate students’ comprehension abilities during this time. 8th grade reading comprehension worksheets are a simple way to help young students improve their reading ability. These easy Comprehending Worksheets and tests help students hone their reading skills, learn vocabulary, and learn what they’re reading. Here is a list of basic vocabulary, grammar, sentence structure, and sentence punctuation worksheets for the 8th grade level. This list can be modified to suit your particular needs.
Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as 1⁄760 of this. Manometric units such as the centimetre of water, millimetre of mercury, and inch of mercury are used to express pressures in terms of the height of column of a particular fluid in a manometer.read more about on wikipedia.org
Some of the ancient tales refer to a banana tree as the Tree of Knowledge of Good and Evil. This plant is known to have originated in the tropical areas of Southeast Asia, and was first cultivated in Papua New Guinea. As of today, it is grown throughout the tropical belt.The botanical name of the banana plant is Musa sapientium. Although this plant closely resembles the palm tree, actually it is an herb and not a tree. Since the plant is tall and strong, it is often referred to as a tree. However, the stem is botanically a 'psuedostem', which can grow to a height of 2 to 8 meters. This pseudostem bears flowers and fruit every year, and then dies to give way to another one of its kind. This stem is covered by enormous number of leaves that overlap each other to form a tough column that protects it from strong winds. This is nature’s method of providing wind resistance to this 'false trunk'. The leaves of this plant are fan shaped, and grow to about 3 meters in length. A single large flower, protected by red bracts, emerges from the apex of the stem. Flowers on a banana plant are red, yellow or black in color. The fruit is borne in bunches called hands at some distance from the flower. These hands have the capacity to contain about 200 bananas, and point upwards due to the effect of light. The bunch laden with fruit weighs approximately 90 pounds, and sometimes even more. This plant reproduces by vegetative propagation of underground roots or budding stems. More Articles : - Banana Care Tips - Banana Facts - Banana Nutritional Facts - Banana Producing Countries - History Of The Banana - How Many Calories Are In A Banana ? - How Many Carbs In A Banana ? - How Many Grams Of Sugar In A Banana ? - How Much Potassium Is In A Banana ? - How Much Protein Is In A Banana ? - Is A Banana A Herb ? - Origin Of Banana - What Does A Banana Tree Look Like ? - What Is The Nutritional Value Of A Banana ? - Why Is A Banana Yellow ?
In August 2016, the first large cruise ship traveled through the Northwest Passage, the northern waterway linking the Atlantic and Pacific oceans. The following year, the first ship without an icebreaker plied the Northern Sea Route, a path along Russia’s Arctic coast that was, until recently, impassable by unescorted commercial vessels. In recent decades parts of the Arctic seas have become increasingly ice-free in late summer and early autumn. As sea ice is expected to continue to recede due to climate change, seasonal ship traffic from tourism and freight is projected to rise. A study from the University of Washington and the University of Alaska Fairbanks considers the potential impacts on the marine mammals that use this region during fall and identify which will be most vulnerable. “We know from more temperate regions that vessels and whales don’t always mix well, and yet vessels are poised to expand into this sensitive region,” said lead author Donna Hauser “Even going right over the North Pole may be passable within a matter of decades. It raises questions of how to allow economic development while also protecting Arctic marine species.” The study looked at 80 subpopulations of the seven marine mammals that live in the Arctic and identified their risks on or near major shipping routes in September, a month when the Arctic Ocean has the most open water. Forty-two of these subpopulations would be exposed to vessel traffic, and the degree of exposure plus the particular characteristics of each species determine which are most sensitive. The most vulnerable marine mammals were found to be narwhals, or tusked whales. These animals migrate through parts of the Northwest Passage to and from their summertime habitats. “Narwhals have all the traits that make them vulnerable to vessel disturbances — they stick to really specific areas, they’re pretty inflexible in where they spend the summer, they live in only about a quarter of the Arctic, and they’re smack dab in the middle of shipping routes,” said co-author Kristin Laidre, a polar scientist. “They also rely on sound, and are notoriously skittish and sensitive to any kind of disturbance.” Other mammals found to be vulnerable were beluga and bowhead whales. Walruses also were vulnerable because some populations are relatively small and known to live along shipping routes, compared to generally large and widely distributed populations of ringed and bearded seals, which were shown to be less vulnerable. The study found the least vulnerable animals were polar bears, which are largely on land during September, and don’t rely on underwater sound for communication or navigation. Shipping in other seasons may have a greater impact. The paper also identified two “pinch points,” narrow passageways where ships and animals are most likely to intersect. These are the Bering Strait that separates the U.S. and Russia, and Lancaster Sound in the northern Canadian territory of Nunavut. These regions had a risk of conflicts two to three times higher than on other parts of the shipping route. Travel through the Arctic Ocean is already beginning, with the Russian route having the most potential for commercial ships. The Northern Sea Route had more than 200 ships from 2011 to 2016, all of which were large vessels. More than 100 vessels passed through the Northwest Passage during that time, with more than half being small, private vessels like personal yachts. Photo credit: Kristin Laidre/University of Washington
Geolocation is the process of determining your location on Earth. Although the concept of geolocation is often connected with GPS, there is more than one way to determine your location when you are on the Internet. For example, your Internet address (IP address) can be used to determine roughly where you are, even without the more advanced methods of geolocation. Suppose that you want a more precise determination of your location than that provided by your IP address. For example, a website may want to know your location in order to provide you with a local map, or to identify a nearby restaurant or hotel. The Opera web browser (Opera) can tell the website approximately where you are, with the help of Google Location Services (GLS). Opera will always ask for your permission, and your privacy will always be respected. Turning on geolocation The first time you go to a website that requests geolocation information, Google Location Services’ terms and conditions are presented. If you agree to them, the service is activated. After that, every time a website requests geolocation information, Opera tells you and gives you the choice to Allow or Block that website. How geolocation works The exact way that geolocation works depends on the device, and its way of connecting to the Internet. If the device is a desktop computer, without any wireless connections, the IP address is used to determine the device’s location, and the measurement is rather crude. To determine the location of a laptop or other wireless device, Opera may additionally send the following data from nearby Wi-Fi access points: - MAC address (uniquely identifies the hardware) - Signal strength (tells how far away it is) A database of known Wi-Fi access points, along with the measured signal strength, makes it possible to give rather precise location information. The success of this method depends largely on the concentration of known access points. If the device is connected to a mobile telephone network, location data may include the cell IDs for the cell towers closest to you, along with their signal strength. If the device is GPS-enabled, the location may be obtained via GPS. Any or all of the above methods may be used to determine the device’s location, if the device has sufficient connectivity. In what follows, we refer to this data as the location data. Checking if a webpage is using location data When you first go to a webpage that uses location data, Opera tells you, and you decide whether or not to send the data. From then on, a pin appears in the address field connected with that page. Clicking on the pin presents you with the options to Allow or Block that website. Your privacy with geolocation Every time a website requests your location data, Opera informs you and asks for your permission to send it. With your permission, Opera passes location data to Google Location Services and sends an estimated latitude and longitude to the website. Opera does not save location data, nor are any cookies generated. Every time your location is requested, Opera redetermines the location data.
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What are Eye Allergies? Eye allergies are a specific form of eye disease caused by different kinds of irritants. These vary from person to person and can include environmental, infectious, or artificial substances. In the process of fighting off this threat, the body’s immune system causes the eyes to release histamine. Histamine is a compound that is released by cells in response to injury and in allergic and inflammatory reactions. This can trigger itchy, red, and watery eyes, as well as inflammation and a bloodshot appearance. Eye allergies mainly affect the surface of the eye as well as the inner folds of the eyelids.2,3,4
This page uses content from Wikipedia and is licensed under CC BY-SA. The Bastarnae (Latin variants: Bastarni, or Basternae; Ancient Greek: Βαστάρναι or Βαστέρναι) were an ancient people who between 200 BC and 300 AD inhabited the region between the Carpathian mountains and the river Dnieper, to the north and east of ancient Dacia. The Peucini, denoted a branch of the Bastarnae by Greco-Roman writers, occupied the region north of the Danube delta. The ethno-linguistic affiliation of the Bastarnae was probably Celtic, which is supported by earliest historians. However, later historian sources imply a Germanic or Scytho-Sarmatian origins. Often they are associated with the Germans, or the peoples "between the Celts and the Germans". The most likely scenario is that they were originally a Celtic tribe, originally resident in the lower Vistula river valley. In ca. 200 BC, these tribes then migrated, possibly accompanied by some Germanic elements, southeastwards into the North Pontic region. Some elements appear to have become assimilated, to some extent, by the surrounding Sarmatians by the 3rd century. Although largely sedentary, some elements may have adopted a semi-nomadic lifestyle. It has not, so far, been possible to identify archaeological sites which can be conclusively attributed to the Bastarnae. The archaeological horizons most often associated by scholars with the Bastarnae are the Zarubintsy and Poienesti-Lukashevka cultures. The Bastarnae first came into conflict with the Romans during the 1st century BC, when, in alliance with Dacians and Sarmatians, they unsuccessfully resisted Roman expansion into Moesia and Pannonia. Later, they appear to have maintained friendly relations with the Roman empire during the first two centuries AD. This changed from c. 180, when the Bastarnae are recorded as participants in an invasion of Roman territory, once again in alliance with Sarmatian and Dacian elements. In the mid-3rd century, the Bastarnae were part of a Gothic-led grand coalition of lower Danube tribes that repeatedly invaded the Balkan provinces of the Roman empire. Large numbers of Bastarnae were resettled within the Roman empire in the late 3rd century. According to Polybius (200 – 118 BC): "A mission from the Dardanians now arrived, telling of the Bastarnae, their numbers, the huge size and the valour of their warriors, and also pointing out that Perseus and the Galatians were in league with this tribe. They said they were much more afraid of him than of the Bastarnae, and they begged for aid." According to Livy (64 BC – 17 AD): "The way to the Hadriatic and to Italy lay through the Scordisci; that was the only practicable route for an army, and the Scordisci were expected to grant a passage to the Bastarnae without any difficulty, for neither in speech nor habits were they dissimilar, and it was hoped that they would unite forces with them when they saw that they were going to secure the plunder of a very wealthy nation." According to Strabo (64 BC – 24 AD): "However, it is clear from the "climata" and the parallel distances that if one travels longitudinally towards the east, one encounters the regions that are about the Borysthenes and that are to the north of the Pontus; but what is beyond Germany and what beyond the countries which are next after Germany — whether one should say the Bastarnae, as most writers suspect, or say that others lie in between, either the Iazyges, or the Roxolani, or certain other of the wagon-dwellers — it is not easy to say; nor yet whether they extend as far as the ocean along its entire length, or whether any part is uninhabitable by reason of the cold or other cause, or whether even a different race of people, succeeding the Germans, is situated between the sea and the eastern Germans. And this same ignorance prevails also in regard to the rest of the peoples that come next in order on the north; for I know neither the Bastarnae, nor the Sauromatae, nor, in a word, any of the peoples who dwell above the Pontus, nor how far distant they are from the Atlantic Sea, nor whether their countries border upon it." Accroding to Plutarch (AD 46 – 120 AD): "He also secretly stirred up the Gauls settled along the Danube, who are called Basternae, an equestrian host and warlike; and he invited the Illyrians, through Genthius their king, to take part with him in the war. And a report prevailed that the Barbarians had been hired by him to pass through lower Gaul, along the coast of the Adriatic, and make an incursion into Italy." According to Tacitus (56 – 120 AD): "As to the tribes of the Peucini, Veneti, and Fenni I am in doubt whether I should class them with the Germans or the Sarmatæ, although indeed the Peucini called by some Bastarnæ, are like Germans in their language, mode of life, and in the permanence of their settlements. They all live in filth and sloth, and by the intermarriages of the chiefs they are becoming in some degree debased into a resemblance to the Sarmatæ." According to Cassius Dio (155 – 235 AD): "During the same period in which these events occurred Marcus Crassus was sent into Macedonia and Greece and carried on war with the Dacians and Bastarnae. I have already stated who the former were and why they had become hostile; the Bastarnae, on the other hand, who are properly classed as Scythians, had at this time crossed the Ister and subdued the part of Moesia opposite them, and afterwards subdued the Triballi who adjoin this district and the Dardani who inhabit the Triballian country." According to Zosismus (490s – 510 AD): "He likewise left in Thrace the Bastarnae, a Scythian people, who submitted to him, giving them land to inhabit there; on which account they observed the Roman laws and customs." The origin of the tribal name is uncertain. It is not even clear whether it was an exonym (a name ascribed to them by outsiders) or an endonym (a name by which the Bastarnae described themselves). A related question is whether the groups denoted "Bastarnae" by the Romans considered themselves a distinct ethnic group at all (endonym) or whether it was a generic exonym used by the Greco-Romans to denote a disparate group of tribes of the Carpathian region that could not be classified as Dacians or Sarmatians. One possible derivation is from the proto-Germanic word bastjan (from Proto-Indo-European root bʰas-) means "binding" or "tie". In this case, Bastarnae may have had the original meaning of a coalition or bund of tribes. It is possible that the Roman term basterna, denoting a type of wagon or litter, is derived from the name of this people (or, if it is an exonym, the name of the people is derived from it) which was known, like many Germanic tribes, to travel with a wagon-train for their families. It has also been suggested that the name is linked with the Germanic word bastard, meaning illegitimate or mongrel. But Batty considers this derivation unlikely. If the name is an endonym, then this derivation is unlikely, as most endonyms have flattering meanings (e.g. "brave", "strong", "noble"). Trubačev proposes a derivation from Old Persian, Avestan bast- "bound, tied; slave" (cf. Ossetic bættən "bind", bast "bound") and Iranian *arna- "offspring", equating it with the δουλόσποροι "slave Sporoi" mentioned by Nonnus and Cosmas, where Sporoi is the people Procopius mentions as the ancestors of the Slavs. The original homeland of the Bastarnae remains uncertain. Babeş and Shchukin argue in favour of an origin in eastern Pomerania on the Baltic coast of todays NW Poland, on the grounds of correspondences in archaeological material e.g. a Pomeranian-style fibula found in a Poieneşti site in Moldavia (although Batty considers the evidence insufficient). Babeş identifies the Sidoni, a branch of the Bastarnae which Strabo places north of the Danube delta with the Sidini located by Ptolemy in Pomerania. Batty argues that Greco-Roman sources of the 1st century AD locate the Bastarnae homeland on the northern side of the Northern Carpathian mountain range, encompassing S.E. Poland and SW Ukraine (i.e. the region traditionally known as Galicia). Pliny locates the Bastarnae between the Suebi and the Dacians (contermini Dacis). The Peutinger Map (produced in ca. 400 AD, but including material from as early as the 1st century) shows the Bastarnae (mis-spelt Blastarni) north of the Carpathian mountains and appears to name the Galician Carpathians as the Alpes Bastarnicae. From Galicia, the Bastarnae expanded into modern-day Moldavia and Bessarabia, reaching the Danube delta. Strabo describes the Bastarnae as inhabiting the territory "between the Ister (river Danube) and the Borysthenes (river Dnieper)". He identifies three sub-tribes of the Bastarnae: the Atmoni, Sidoni and Peucini. The latter derived their name from Peuce, a large island in the Danube delta, which they had colonised. The 2nd-century geographer Ptolemy states that the Carpiani or Carpi (believed to have occupied Moldavia) separated the Peucini from the other Bastarnae "above Dacia" (i.e. north of Dacia). It thus appears that the Bastarnae were settled in a vast arc stretching around the northern and eastern flanks of the Carpathians from SE Poland to the Danube delta. The larger group inhabited the northern and eastern slopes of the Carpathians and the region between the Prut and Dnieper rivers (Moldova Republic/Western Ukraine), while a separate group (the Peucini, Sidoni and Atmoni) dwelt in and north of the Danube delta region. Scholars hold divergent theories about the ethnicity of the Bastarnae. The view, following what appears to be the most authoritative view among earliest scholars, is that they spoke Celtic. However others hold that they were Scythian/Germanic, or mixed Germanic/Sarmatian. A fringe theory is that they were Proto-Slavic. Shchukin argues that ethnicity of the Bastarnae was unique and rather than trying to label the Bastanae as Celtic, Germanic or Sarmatian, it should be accepted that the "Basternae were the Basternae". Batty argues that assigning an "ethnicity" to the Bastarnae is meaningless, as in the context of the Iron Age Pontic-Danubian region, with its multiple overlapping peoples and languages, ethnicity was a very fluid concept: it could and did change rapidly and frequently, according to socio-political vicissitudes. This was especially true of the Bastarnae, who are attested over a relatively vast area. A leading reason to consider the Bastarnae as Celtic is that the regions they are documented to have occupied (northern and eastern slopes of the Carpathians) overlapped to a great extent with the locations of Celtic tribes attested in the northern Carpathians. Indeed, a large part of this region, Galicia, may derive its name from its former Celtic inhabitants the Taurisci, Osi, Cotini and Anartes of Slovakia and northern Romania and the Britogalli of the Danubian Mouth region. In addition, archaeological cultures, which some scholars have linked to the Bastarnae (Poieneşti-Lukashevka and Zarubintsy), display pronounced Celtic affinities. Finally, the arrival of the Bastarnae in the Pontic-Danubian region, which can be dated to 233-216 BC according to two ancient sources, coincides with the latter phase of Celtic migration into the region (400-200 BC). The earliest historians give a Celtic or Gallic origin to the Bastarnae. Roman historian Livy, writing in c. AD 10, attest that the Bastarnae spoke Celtic. Relating the Bastarnic invasion of the Balkans of 179 BC (see Conflict with Rome below), he describes them then as "they were not very different in either language or manners" to the Celtic tribe of the Scordisci, a tribe of Pannonia. The Scordisci are described as Celtic by Strabo (although he adds that they had mingled with Illyrians and Thracians). The Greeks historian Plutarch inform us that the Roman consul Hostilius "secretly stirred up the Gauls settled along the Danube, who are called Basternae". However, a Celtic identity for the Bastarnae is apparently contradicted by Polybius (writing ca. 150 BC), who was an actual contemporary of the events described, unlike Livy, who was writing some 200 years later. Polybius clearly distinguishes the Bastarnae from the "Galatae" (i.e. Celts): "an embassy from the Dardani arrived [at the Roman Senate], talking of the Bastarnae, their huge numbers, the strength and valour of their warriors, and also reporting that Perseus [king of Macedon] and the Galatae were in league with this tribe". In addition, inscription AE (1905) 14, recording a campaign on the Hungarian Plain by the Augustan-era general Marcus Vinucius (10 BC or 8 BC), also appears to distinguish the Bastarnae from neighbouring Celtic tribes: "Marcus Vinucius... governor of Illyricum, the first [Roman general] to advance across the river Danube, defeated in battle and routed an army of Dacians and Basternae, and subjugated the Cotini, Osi,...[missing tribal name] and Anartii to the power of the emperor Augustus and of the people of Rome." Greco-Roman geographers of the 1st century AD are unanimous and specific that the Bastarnae were Germanic in language and culture. The Greek geographer Strabo (writing c. AD 5-20) says the Bastarnae are "of Germanic stock". The Roman geographer Pliny the Elder (c. AD 77), classifies the Bastarnae and Peucini as constituting one of the 5 main subdivisions of Germanic peoples (he lists the other subdivisions as the Inguaeones, Istuaeones and Hermiones (West Germanic tribes), and the Vandili (Vandals, East Germanic, but he classifies differently than the Bastarnae). The Roman historian Tacitus (c. AD 100) describes the Bastaenae as Germans with substantial Sarmatian influence, but moves on to state: "The Peucini, however, who are sometimes called Bastarnae, are like the Germans in their language, way of life and types of dwelling." Strabo includes the Roxolani, generally considered by scholars to have been a Sarmatian tribe, in a list of Bastarnae subgroups. However, this may simply be an error due to the close proximity of the two peoples north of the Danube delta. In the 3rd century, the Greek historian Dio Cassius states that the "Bastarnae are properly classed as Scythians" and "members of the Scythian race". Likewise, the 6th-century historian Zosimus, reporting events around AD 280, refers to "the Bastarnae, a Scythian people". However, it appears that these late Greco-Roman chroniclers used the term "Scythian" more often in a geographical sense (i.e. inhabitants of the region they called Scythia i.e. the Pontic region north of the Danube) rather than in an ethnic one (i.e. members of the Scythian people, steppe nomads of Iranic origin, related to the Sarmatians, who had supplanted the Scythians' dominance of the steppes in the period BC). For example, Zosimus also routinely refers to the Goths, who were undoubtedly Germanic-speakers, as "Scythians". It is possible that some Bastarnae may have been assimilated by the surrounding (and possibly dominant) Sarmatians, perhaps adopting their tongue (which belonged to the Iranian group of Indo-European languages) and/or Sarmatian customs. Thus Tacitus' comment that "mixed marriages are giving [the Bastarnae] to some extent the vile appearance of the Sarmatians". On the other hand, the Bastarnae maintained a separate name-identity until ca. AD 300, probably implying retention of their distinctive ethno-linguistic heritage until that time. It seems, on balance, likely that the core population of Bastarnae had always been, and continued to be, Germanic in language and culture. According to Todd, traditional archaeology has not been able to construct a typology of Bastarnae material culture, and thus to ascribe particular archaeological sites to the Bastarnae. A complicating factor is that the regions where Bastarnae are attested contained a patchwork of peoples and cultures (Sarmatians, Scythians, Dacians, Thracians, Celts, Germans and others), some sedentary, some nomadic. In any event, post-1960s archaeological theory questions the validity of equating material "cultures", as defined by archaeologists, with distinct ethnic groups. On this view, it is impossible to attribute a "culture" to a particular ethnic group: it is likely that the material cultures discerned in the region belonged to several, if not all, of the groups inhabiting it. These cultures probably represent relatively large-scale socio-economic interactions between disparate communities of the broad region, possibly including mutually antagonistic groups. It is not even certain whether the Bastarnae were sedentary or nomadic (or semi-nomadic). Tacitus' statement that they were "German in their way of life and types of dwelling" implies a sedentary bias, but their close relations with the Sarmatians, who were nomadic, may indicate a more nomadic lifestyle for some Bastarnae, as does the wide geographical range of their attested inhabitation. If the Bastarnae were nomadic, then the sedentary "cultures" identified by archaeologists in their lebensraum would not represent them. Nomadic peoples generally leave scant traces, due to the impermanent materials and foundations used in the construction of their dwellings. Scholars have identified two closely related sedentary "cultures" as possible candidates to represent the Bastarnae (among other peoples) as their locations broadly correspond to where ancient sources placed the Basternae: the Zarubintsy culture lying in the forest-steppe zone in northern Ukraine-southern Belarus, and the Poieneşti-Lukashevka (Lucăşeuca) culture in northern Moldavia. These cultures were characterised by agriculture, documented by numerous finds of sickles. Dwellings were either of surface or semi-subterranean types, with posts supporting the walls, a hearth in the middle, and large conical pits located nearby. Some sites were defended by ditches and banks, structures thought to have been built to defend against nomadic tribes from the steppe. Inhabitants practiced cremation. Cremated remains were either placed in large, hand-made ceramic urns, or were placed in a large pit and surrounded by food and ornaments such as spiral bracelets and Middle to Late La Tène-type fibulae (attesting the continuing strength of Celtic influence in this region). A major problem with associating Lukashevka and Zarubintsy with the Bastarnae is that both cultures had disappeared by the early 1st century AD, although the Bastarnae continue to be attested in those regions throughout the Roman Principate. Another issue is that the Poieneşti-Lukashevka culture has also been attributed to the Costoboci, a people considered ethnic-Dacian by mainstream scholarship, which inhabited northern Moldavia, according to Ptolemy (ca. AD 140). Indeed, Mircea Babeş and Silvia Theodor, the two Romanian archaeologists who identified Lukashevka as Bastarnic, nevertheless insisted that the majority of the population in the Lukashevka sphere (N. Moldavia) was "Geto-Dacian". A further problem is that neither of these cultures were present in the Danube delta region, where a major concentration of Bastarnae are attested by the ancient sources. Starting in about AD 200, the Chernyakhov culture became established in the W. Ukraine/Moldova region inhabited by the Bastarnae. The culture is characterised by a high degree of sophistication in the production of metal and ceramic artefacts, as well as of uniformity over a vast area. Although this culture has conventionally been identified with the migration of the Gothic ethnos into the region from the Northwest, Todd argues that its most important origin is Scytho-Sarmatian. Although the Goths certainly contributed to it, so probably did other peoples of the region such as the Dacians, proto-Slavs, Carpi, and possibly the Bastarnae. The Bastarnae first appear in the historical record in 179 BC, when they crossed the Danube in massive force. They did so at the invitation of their long-time ally, king Philip V of Macedon, a direct descendant of Antigonus, one of the Diadochi, the generals of Alexander the Great who had shared out his empire after his death in 323 BC. The Macedonian king had suffered a disastrous defeat at the hands of the Romans in the Second Macedonian War (200-197 BC), which had reduced him from a powerful Hellenistic monarch to the status of a petty client-king with a much-reduced territory and a tiny army.[Note 1] After nearly 20 years of slavish adherence to the Roman Senate's dictats, Philip had been goaded beyond endurance by the incessant and devastating raiding of the Dardani, a warlike Thraco-Illyrian tribe on his northern border, which his treaty-limited army was too small to counter effectively. Counting on the Bastarnae, with whom he had forged friendly relations in earlier times, he plotted a strategy to deal with the Dardani and then to regain his lost territories in Greece and his political independence. First, he would unleash the Bastarnae against the Dardani. After the latter had been crushed, Philip planned to settle Bastarnae families in Dardania (southern Kosovo/Skopje region), to ensure that the region was permanently subdued. In a second phase, Philip aimed to launch the Bastarnae on an invasion of Italy via the Adriatic coast. Although he was aware that the Bastarnae were hardly likely to achieve the same success as Hannibal some 40 years earlier, and would most likely end up cut to pieces by the Romans, Philip hoped that the Romans would be distracted long enough to allow him to reoccupy his former possessions in Greece. But Philip, now 60 years of age, died before the Bastarnae could arrive. The Bastarnae host was still en route through Thrace, where it became embroiled in hostilities with the locals, who were unable (or unwilling) to provide them with sufficient food at affordable prices as they marched through. Probably in the vicinity of Philippopolis (modern Plovdiv, Bulgaria), the Bastarnae broke out of their marching columns and pillaged the land far and wide. The terrified local Thracians took refuge with their families and animal herds on the slopes of Mons Donuca, the highest mountain in Thrace (Mt. Musala, Rila Mts., Bulgaria). A large force of Bastarnae chased them up the mountain, but were driven back and scattered by a massive hailstorm. Then the Thracians ambushed them, turning their descent into a panic-stricken rout. Back at their wagon-laager in the plain, around half the demoralised Bastarnae decided to return home, leaving c. 30,000 to press on to Macedonia. Philip's son and successor Perseus, while protesting his loyalty to Rome, deployed his Bastarnae guests in winter quarters in a valley in Dardania, presumably as a prelude to a campaign against the Dardani the following summer. But in the depths of winter their camp was attacked by the Dardani. The Bastarnae easily beat off the attackers, chased them back to their chief town, and besieged them. But they were surprised in the rear by a second force of Dardani, which had approached their camp stealthily by mountain paths, and proceeded to storm and ransack it. Having lost their entire baggage and supplies, the Bastarnae were obliged to withdraw from Dardania and to return home. Most perished as they crossed the frozen Danube on foot, only for the ice to give way. Despite the failure of Philip's Bastarnae strategy, the suspicion aroused by these events in the Roman Senate, which had been warned by the Dardani of the Bastarnae invasion, ensured the demise of Macedonia as an independent state. Rome declared war on Perseus in 171 BC and after the Macedonian army was crushed at the Battle of Pydna (168 BC), Macedonia was split up into 4 Roman puppet-cantons (167 BC). 21 years later, these were in turn abolished and annexed to the Roman Republic as the province of Macedonia (146 BC). The Bastarnae first came into direct conflict with Rome as a result of expansion into the lower Danube region by the proconsuls (governors) of Macedonia in the period 75-72 BC. Gaius Scribonius Curio (proconsul 75-3 BC) campaigned successfully against the Dardani and the Moesi, becoming the first Roman general to reach the river Danube with his army. His successor, Marcus Licinius Lucullus (brother of the famous Lucius Lucullus), campaigned against the Thracian Bessi tribe and the Moesi, ravaging the whole of Moesia, the region between the Haemus (Balkan) mountain range and the Danube. In 72 BC, his troops occupied the Greek coastal cities of Scythia Minor (modern Dobruja region, Romania/Bulgaria),[Note 2] which had sided with Rome's Hellenistic arch-enemy, king Mithridates VI of Pontus, in the Third Mithridatic War (73-63 BC). The presence of Roman forces in the Danube delta was seen as a major threat by all the neighbouring transdanubian peoples: the Peucini Bastarnae, the Sarmatians and, most importantly, by Burebista (ruled 82-44 BC), king of the Getae. The Getae occupied the region today called Wallachia as well as Scythia Minor and were either a Dacian- or Thracian- speaking people.[Note 3] Burebista had unified the Getae tribes into a single kingdom, for which the Greek cities were vital trade outlets. In addition, he had established his hegemony over neighbouring Sarmatian and Bastarnae tribes. At its peak, the Getae kingdom reportedly was able to muster 200,000 warriors. Burebista led his transdanubian coalition in a struggle against Roman encroachment, conducting many raids against Roman allies in Moesia and Thrace, penetrating as far as Macedonia and Illyria. The coalition's main chance came in 62 BC, when the Greek cities rebelled against Roman rule. In 61 BC, the notoriously oppressive and militarily incompetent proconsul of Macedonia, Gaius Antonius, nicknamed Hybrida ("The Monster", an uncle of the famous Mark Antony) led an army against the Greek cities. As his army approached Histria (Sinoe), Antonius detached his entire mounted force from the marching column and led it away on a lengthy excursion, leaving his infantry without cavalry cover, a tactic he had already used with disastrous results against the Dardani. Dio implies that he did so out of cowardice, in order to avoid the imminent clash with the opposition. But it is more likely that he was pursuing a large enemy cavalry force, probably Sarmatians. A Bastarnae host, which had crossed the Danube to assist the Histrians, promptly attacked, surrounded and massacred the Roman infantry, capturing several of their vexilla (military standards). This battle resulted in the collapse of the Roman position on the lower Danube. Burebista apparently annexed the Greek cities (55-48 BC). At the same time, the subjugated "allied" tribes of Moesia and Thrace evidently repudiated their treaties with Rome, as they had to be re-conquered by Augustus in 29-8 BC (see below). For 44 BC, Roman dictator-for-life Julius Caesar planned to lead a major campaign to crush Burebista and his allies once and for all, but he was assassinated before it could start. However, the campaign was made redundant by Burebista's overthrow and death in the same year, after which his Getae empire fragmented into 4, later 5 independent petty kingdoms. These were militarily far weaker, as Strabo assessed their combined military potential at just 40,000 armed men, and were often involved in internecine warfare. The Geto-Dacians did not again become a threat to Roman hegemony in the lower Danube until the rise of Decebal 130 years later (AD 86). Once he had established himself as sole ruler of the Roman state in 30 BC, Caesar's grand-nephew and adopted son Augustus inaugurated a strategy of advancing the empire's southeastern European border to the line of the Danube from the Alps, the Dinaric Alps and Macedonia. The primary objective was to increase strategic depth between the border and Italy and also to provide a major fluvial supply-route between the Roman armies in the region. On the lower Danube, which was given priority over the upper Danube, this required the annexation of Moesia. The Romans' target were thus the tribes which inhabited Moesia, namely (from West to East) the Triballi, Moesi and those Getae who dwelt South of the Danube. The Bastarnae were also a target because they had recently subjugated the Triballi, whose territory lay on the southern bank of the Danube between the tributary rivers Utus (Vit) and Ciabrus (Tsibritsa), with their chief town at Oescus (Gigen, Bulgaria). In addition, Augustus wanted to avenge the defeat of C. Antonius at Histria (Sinoe) 32 years before and to recover the lost military standards. These were held in a powerful fortress called Genucla (Isaccea, near modern Tulcea, Romania, in the Danube delta region), controlled by Zyraxes, the local Getan king. The man selected for the task was Marcus Licinius Crassus, grandson of Crassus the triumvir and an experienced general at 33 years of age, who was appointed proconsul of Macedonia in 29 BC. The Bastarnae provided the casus belli by crossing the Haemus and attacking the Dentheletae, a Thracian tribe who were Roman allies. Crassus marched to the Dentheletae's assistance, but the Bastarnae host hastily withdrew over the Haemus at his approach. Crassus followed them closely into Moesia but they would not be drawn into battle, withdrawing beyond the Tsibritsa. Crassus now turned his attention to the Moesi, his prime target. After a successful campaign which resulted in the submission of a substantial section of the Moesi, Crassus again sought out the Bastarnae. Discovering their location from some peace envoys they had sent to him, he lured them into battle near the Tsibritsa by a stratagem. Hiding his main body of troops in a wood, he stationed as bait a smaller vanguard in open ground before the wood. As expected, the Bastarnae attacked the vanguard in force, only to find themselves entangled in the full-scale pitched battle with the Romans that they had tried to avoid. The Bastarnae tried to retreat into the forest but were hampered by the wagon-train carrying their women and children, as these could not move through the trees. Trapped into fighting to save their families, the Bastarnae were routed. Crassus personally killed their king, Deldo, in combat, a feat which qualified him for Rome's highest military honour, spolia opima, but Augustus refused to award it on a technicality.[Note 4] Thousands of fleeing Bastarnae perished, many asphyxiated in nearby woods by encircling fires set by the Romans, others drowned trying to swim across the Danube. Nevertheless, a substantial force dug themselves into a powerful hillfort. Crassus laid siege to fort, but had to enlist the assistance of Rholes, a Getan petty king, to dislodge them, for which service Rholes was granted the title of socius et amicus populi Romani ("ally and friend of the Roman people"). The following year (28 BC), Crassus marched on Genucla. Petty king Zyraxes escaped with his treasure and fled over the Danube into Scythia to seek aid from the Bastarnae. But before he was able to bring reinforcements, Genucla fell to a combined land and fluvial assault by the Romans. The strategic result of Crassus' campaigns was the permanent annexation of Moesia by Rome. About a decade later, in 10 BC, the Bastarnae again clashed with Rome during Augustus' conquest of Pannonia (the bellum Pannonicum 14–9 BC). Inscription AE (1905) 14 records a campaign on the Hungarian Plain by the Augustan-era general Marcus Vinucius: "Marcus Vinucius...[patronymic], Consul [in 19 BC]...[various official titles], governor of Illyricum, the first [Roman general] to advance across the river Danube, defeated in battle and routed an army of Dacians and Basternae, and subjugated the Cotini, Osi,...[missing tribal name] and Anartii to the power of the emperor Augustus and of the people of Rome." Most likely, the Bastarnae, in alliance with Dacians, were attempting to assist the hard-pressed Illyrian/Celtic tribes of Pannonia in their resistance to Rome. It appears that in the final years of Augustus' rule, the Bastarnae made their peace with Rome. The Res Gestae Divi Augusti ("Acts of the divine Augustus" AD 14), a self-congratulatory inscription commissioned by Augustus to list his achievements, states that he received an embassy from the Bastarnae seeking a treaty of friendship. It appears that a treaty was concluded and apparently proved remarkably effective, as no hostilities with the Bastarnae are recorded in surviving ancient sources until c. 175, some 160 years after Augustus' inscription was carved. But surviving evidence for the history of this period is so thin that it cannot be excluded that the Bastarnae clashed with Rome during it.[Note 5] The Bastarnae may have been involved in the Dacian Wars of Domitian (86-88) and Trajan (101-102 and 105-106), since these took place in the lower Danube region and it is known that both sides were supported by neighbouring indigenous tribes.[original research?] In the late 2nd century, the Historia Augusta mentions that in the rule of Marcus Aurelius (161-80), an alliance of lower Danube tribes including the Bastarnae, the Sarmatian Roxolani and the Costoboci took advantage of the emperor's difficulties on the upper Danube (the Marcomannic Wars) to invade Roman territory. During the late 2nd century, the main ethnic change in the northern Black sea region was the immigration, from the Vistula valley in the North, of the Goths and accompanying Germanic tribes such as the Taifali and the Hasdingi, a branch of the Vandal people. This migration was part of a series of major population movements in the European barbaricum (the Roman term for regions outside their empire). The Goths appear to have established a loose political hegemony over the existing tribes in the region. Under the leadership of the Goths, a series of major invasions of the Roman empire were launched by a grand coalition of lower Danubian tribes from c. 238 onwards. The participation of the Bastarnae in these is likely but largely unspecified, due to Zosimus' and other chroniclers' tendency to lump all these tribes under the general term "Scythians" - meaning all the inhabitants of Scythia, rather than the specific Iranic-speaking people called the Scythians. Thus, in 250-1, the Bastarnae were probably involved in the Gothic and Sarmatian invasions which culminated in the Roman defeat at the Battle of Abrittus and the slaying of the emperor Decius (251). This disaster was the start of the Third Century Crisis of the Roman empire, a period of military and economic chaos. At this critical moment, the Roman army was crippled by the outbreak of a second smallpox pandemic, the plague of Cyprian (251-70). The effects are described by Zosimus as even worse than the earlier Antonine plague (166-80), which probably killed 15-30% of the empire's inhabitants. Taking advantage of Roman military disarray, a vast number of barbarian peoples overran much of the empire. The Sarmato-Gothic alliance of the lower Danube carried out major invasions of the Balkans region in 252, and in the periods 253-8 and 260-8. The Peucini Bastarnae are specifically mentioned in the 267/8 invasion, when the coalition built a fleet in the estuary of the river Tyras (Dnieper). The Peucini Bastarnae would have been critical to this venture since, as coastal and delta dwellers, they would have had seafaring experience that the nomadic Sarmatians and Goths lacked. The barbarians sailed along the Black Sea coast to Tomis in Moesia Inferior, which they tried to take by assault without success. They then attacked the provincial capital Marcianopolis (Devnya, Bulg.), also in vain. Sailing on through the Bosporus, the expedition laid siege to Thessalonica in Macedonia. Driven off by Roman forces, the coalition host moved overland into Thracia, where finally it was crushed by emperor Claudius II (r. 268-70) at Naissus (269). Claudius II was the first of a sequence of military emperors (the so-called "Illyrian emperors" from their main ethnic origin) who restored order in the empire in the late 3rd century. These emperors followed a policy of large-scale resettlement within the empire of defeated barbarian tribes, granting them land in return for an obligation of military service much heavier than the usual conscription quota. The policy had the triple benefit, from the Roman point of view, of weakening the hostile tribe, repopulating the plague-ravaged frontier provinces (bringing their abandoned fields back into cultivation) and providing a pool of first-rate recruits for the army. But it could also be popular with the barbarian prisoners, who were often delighted by the prospect of a land grant within the empire. In the 4th century, such communities were known as laeti. The emperor Probus (r. 276-82) is recorded as resettling 100,000 Bastarnae in Moesia, in addition to other peoples (Goths, Gepids and Vandals). The Bastarnae are reported to have honoured their oath of allegiance to the emperor, while the other resettled peoples mutinied while Probus was distracted by usurpation attempts and ravaged the Danubian provinces far and wide. A further massive transfer of Bastarnae was carried out by emperor Diocletian (ruled 284-305) after he and his colleague Galerius defeated a coalition of Bastarnae and Carpi in 299. The remaining transdanubian Bastarnae disappear into historical obscurity in the late empire. Neither of the main ancient sources for this period, Ammianus Marcellinus and Zosimus, mention the Bastarnae in their accounts of the 4th century, possibly implying the loss of their separate identity, presumably assimilated by the regional hegemons, the Goths. Such assimilation would have been facilitated if, as is possible, the Bastarnae spoke an East Germanic language closely related to Gothic. If the Bastarnae remained an identifiable group, it is highly likely that they participated in the vast Gothic-led migration, driven by Hunnic pressure, that was admitted into Moesia by emperor Valens in 376 and eventually defeated and killed Valens at Adrianople in 378. Although Ammianus refers to the migrants collectively as "Goths", he states that, in addition, "Taifali and other tribes" were involved. However, after a gap of 150 years, there is a final mention of Bastarnae in the mid-5th century. In 451, the Hunnic leader Attila invaded Gaul with a large army which was ultimately routed at the Battle of Châlons by a Roman-led coalition under the general Aetius. Attila's host, according to Jordanes, included contingents from the "innumerable tribes that had been brought under his sway." One such were the Bastarnae, according to the Gallic nobleman Sidonius Apollinaris. However, E.A. Thompson argues that Sidonius' mention of Bastarnae at Chalons is probably false: his purpose was to write a panegyric and not a history, and Sidonius added some spurious names to the list of real participants (e.g. Burgundians, Sciri and Franks) for dramatic effect. \|Wikimedia Commons has media related to Bastarnae.\| \|Wikisource has the text of the 1911 Encyclopædia Britannica article Bastarnae.\|
What's in this article? Pink Eye Overview Pink eye (conjunctivitis) is an inflammation or infection of the transparent membrane (conjunctiva) that lines your eyelid and covers the white part of your eyeball. When small blood vessels in the conjunctiva become inflamed, they’re more visible. This is what causes the whites of your eyes to appear reddish or pink. Pink eye is commonly caused by a bacterial or viral infection, an allergic reaction, or in babies an incompletely opened tear duct. Though pink eye can be irritating, it rarely affects your vision. Treatments can help ease the discomfort of pink eye. Because pink eye can be contagious, early diagnosis and treatment can help limit its spread. What Causes Pink eye? Pink eye has a number of different causes, including: - Bacteria (such as gonorrhea or chlamydia) - Irritants such as shampoos, dirt, smoke, and pool chlorine - Allergies, like dust, pollen, or a special type of allergy that affects some contact lens wearers Pink eye caused by some bacteria and viruses can spread easily from person to person, but is not a serious health risk if diagnosed promptly. Pink eye in newborn babies, however, should be reported to a doctor immediately, as it could be a vision-threatening infection. Pink Eye Symptoms No surprise: the primary symptom of pink eye is an eye that has a pink appearance. Other symptoms of pink eye depend on the type of conjunctivitis you have: - Viral conjunctivitis. Watery, itchy eyes; sensitivity to light. One or both eyes can be affected. Highly contagious; can be spread by coughing and sneezing. - Bacterial conjunctivitis. A sticky, yellow or greenish-yellow eye discharge in the corner of the eye. In some cases, this discharge can be severe enough to cause the eyelids to be stuck together when you wake up. One or both eyes can be affected. Contagious (usually by direct contact with infected hands or items that have touched the eye). - Allergic conjunctivitis. Watery, burning, itchy eyes; often accompanied by stuffiness and a runny nose, and light sensitivity. Both eyes are affected. Not contagious. How is conjunctivitis diagnosed? Conjunctivitis can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on evaluation of the conjunctiva and surrounding tissues, may include: - Patient history to determine the symptoms the patient is experiencing, when the symptoms began, and the presence of any general health or environmental conditions that may be contributing to the problem. - Visual acuity measurements to determine the extent to which vision may be affected. - Evaluation of the conjunctiva and external eye tissue using bright light and magnification. - Evaluation of the inner structures of the eye to ensure that no other tissues are affected by the condition. - Supplemental testing may include taking cultures or smears of conjunctival tissue, particularly in cases of chronic conjunctivitis or when the condition is not responding to treatment. Using the information obtained from these tests, your optometrist can determine if you have conjunctivitis and advise you on treatment options. How Is Pink eye Treated? The treatment for pink eye depends on the cause. - Bacteria. Pink eye caused by bacteria, including those related to STDs, is treated with antibiotics, in the form of eye drops, ointments, or pills. Eye drops or ointments may need to be applied to the inside of the eyelid three to four times a day for five to seven days. Pills may need to be taken for several days. The infection should improve within a week. Take or use the drugs as instructed by your doctor, even if the symptoms go away. - Viruses. This type of pink eye often results from the viruses that cause a common cold. Just as a cold must run its course, so must this form of pink eye, which usually lasts from four to seven days. Viral conjunctivitis can be highly contagious. Avoid contact with others and wash your hands frequently. If you wear contact lenses, you should throw away contacts worn while you have pink eye and wear glasses. Same for makeup. - Irritants. For pink eye caused by an irritating substance, use water to wash the substance from the eye for five minutes. Your eyes should begin to improve within four hours. If the conjunctivitis is caused by acid or alkaline material such as bleach, immediately rinse the eyes with lots of water and call your doctor immediately. - Allergies. Allergy-associated conjunctivitis should improve once the allergy is treated and the allergen removed. See your doctor if you have conjunctivitis that is linked to an allergy.
\|Pre-production\|\|This is also called “the silent period,” when the student takes in the new language but does not speak it. This period often lasts six weeks or longer, depending on the individual.\| \|Early production\|\|The individual begins to speak using short words and sentences, but the emphasis is still on listening and absorbing the new language. There will be many errors in the early production stage.\| \|Speech Emergent\|\|Speech becomes more frequent, words and sentences are longer, but the individual still relies heavily on context clues and familiar topics. Vocabulary continues to increase and errors begin to decrease, especially in common or repeated interactions.\| \|Beginning Fluency\|\|Speech is fairly fluent in social situations with minimal errors. New contexts and academic language are challenging and the individual will struggle to express themselves due to gaps in vocabulary and appropriate phrases.\| \|Intermediate Fluency\|\|Communicating in the second language is fluent, especially in social language situations. The individual is able to speak almost fluently in new situations or in academic areas, but there will be gaps in vocabulary knowledge and some unknown expressions. There are very few errors, and the individual is able to demonstrate higher order thinking skills in the second language such as offering an opinion or analyzing a problem.\| \|Advanced Fluency\|\|The individual communicates fluently in all contexts and can maneuver successfully in new contexts and when exposed to new academic information. At this stage, the individual may still have an accent and use idiomatic expressions incorrectly at times, but the individual is essentially fluent and comfortable communicating in the second language.\| How long does it take for a language learner to go through these stages? Just as in any other learning situation, it depends on the individual. One of the major contributors to accelerated second language learning is the strength of first language skills. Language researchers such as Jim Cummins, Catherine Snow, Lily Wong Filmore and Stephen Krashen have studied this topic in a variety of ways for many years. The general consensus is that it takes between five to seven years for an individual to achieve advanced fluency. This generally applies to individuals who have strong first language and literacy skills. If an individual has not fully developed first language and literacy skills, it may take between seven to ten years to reach advanced fluency. It is very important to note that every ELL student comes with his or her own unique language and education background, and this will have an impact on their English learning process. It is also important to keep in mind that the understood goal for American ELL students is Advanced Fluency, which includes fluency in academic contexts as well as social contexts. Teachers often get frustrated when ELL students appear to be fluent because they have strong social English skills, but then they do not participate well in academic projects and discussions. Teachers who are aware of ELL students’ need to develop academic language fluency in English will be much better prepared to assist those students in becoming academically successful. (Learn more about academic language in Colorín Colorado’s academic language resource section.) To All the Boys I’ve Loved Before By Jenny Han MAJOR MOTION PICTURE COMING TO NETFLIX AUGUST 17, 2018! Lara Jean’s love life gets complicated in this New York Times bestselling “lovely, lighthearted romance” (SLJ) from the New York Times bestselling author of The Summer I Turned Pretty series. What if all the crushes you ever had found out how you felt about them…all at once? Sixteen-year-old Lara Jean Song keeps her love letters in a hatbox her mother gave her. They aren’t love letters that anyone else wrote for her; these are ones she’s written. One for every boy she’s ever loved—five in all. When she writes, she pours out her heart and soul and says all the things she would never say in real life, because her letters are for her eyes only. Until the day her secret letters are mailed, and suddenly, Lara Jean’s love life goes from imaginary to out of control.
Jupiter’s moon Ganymede is the largest and most massive of the Solar System’s moons. It has a mean radius of 2634.1±0.3 km (about 1636 miles, 0.413 Earths). For comparison, our Moon’s radius is 1,737.1 km (1079 mi). What if Ganymede was the Earth’s second moon? How would it look in the sky, if it was at the same distance as the Moon? It would of course cause much higher tidal forces than the moon. What’s more, Ganymede’s crust is very rich in water ice. If it was orbiting Earth that ice would quickly melt and turn it into an ocean moon. It would also quickly develop an atmosphere, possibly mostly water vapor but probably also with a bunch of other volatiles that was trapped in the ice. So it wouldn’t look like that photo for long, it would quickly turn into a blue and white swirly ball. There is some speculation that Ganymede’s existing internal ocean (that may contain more water than all of Earth’s oceans combined) may already be hospitable for life, which means there might even already be native Ganymedan life. Probably just microorganisms but if human civilization survives the tidal effects of all this, it could be a scientific gem. With a mean radius of 2634.1±0.3 km (about 1636 miles), Ganymede is 8% larger than the planet Mercury (2,439.7 km), although only 45% as massive. It is the ninth largest object in the Solar System and the largest without a substantial atmosphere. Astronomers using the Hubble Space Telescope found evidence of thin oxygen atmosphere on Ganymede in 1996. The atmosphere is far too thin to support life as we know it. Ganymede is the only moon with its own magnetic field, which causes auroras. Scientists have also found strong evidence of an underground ocean on Ganymede. Ganymede was discovered by Galileo Galilei on January 7, 1610. The discovery, along with three other Jovian moons, was the first time a moon was discovered orbiting a planet other than Earth. The discovery of the four Galilean satellites eventually led to the understanding that planets in our solar system orbit the sun, instead of our solar system revolving around Earth. Ganymede is named for a boy who was made cupbearer for the ancient Greek gods by Zeus (Zeus is “Jupiter” to the Romans). The Galilean moons are the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in January 1610 and recognized by him as satellites of Jupiter in March 1610, hence the term. The German astronomer Simon Marius (1573-1625) probably made an independent discovery of the moons at about the same time that Galileo did, and he may have unwittingly sighted them up to a month earlier, but the priority must go to Galileo because he published his discovery first. Completed missions to Ganymede Several probes flying by or orbiting Jupiter have explored Ganymede more closely, including four flybys in the 1970s, and multiple passes in the 1990s to 2000s. Pioneer 10 approached in 1973 and Pioneer 11 in 1974, and they returned information about the satellite. This included a more specific determination on physical characteristics and resolving features to 400 km (250 mi) on its surface. Pioneer 10’s closest approach was 446,250 km. Voyager 1 and Voyager 2 were next, passing by the moon in 1979. They refined its size, revealing it was larger than Saturn’s moon Titan, which was previously thought to have been bigger. The grooved terrain was also seen. In 1995, the Galileo spacecraft entered orbit around Jupiter and between 1996 and 2000 made six close flybys to explore Ganymede. These flybys are denoted G1, G2, G7, G8, G28, and G29. During the closest flyby (G2), Galileo passed just 264 km from its surface. During a G1 flyby in 1996, the Ganymedian magnetic field was discovered, while the discovery of the ocean was announced in 2001. Galileo transmitted a large number of spectral images and discovered several non-ice compounds on the surface. Latest posts by M. Özgür Nevres (see all) - Apollo 17 and its destination (Moon) in one photo - June 23, 2019 - Solar System through the eyes of Hubble Space Telescope - June 15, 2019 - What if Ganymede was the Earth’s second moon? - June 12, 2019
Assessment dominates education from K-12 through college. There are different types of assessment, formative (helps students improve) and summative (grading of students). However, institutional assessment involves the bigger picture of how an institution or a department is doing academically. In institutional assessment, teachers enter data into a mega-database. For example, teachers may enter their students’ grades on each section of the final. Then someone, often a department head, analyzes the overall results using the online data, to assess the student learning across specific courses and across the department. Institutional assessment has some basic flows 1) Most institutions have not identified a specific enough curriculum that can be assessed. Many contain very general statements of learning. For example, English might state that students will write a well-written essay. Has the English department specified what constitutes a well-written essay? Likewise, a Modern language department may have the curriculum statement “The student should speak in sentences that have relatively simple structures and concrete vocabulary”. What does “speak” mean? Does it mean to be able to talk about one’s life, to hold a conversation. to repeat from memory? When there are only general learning statements, there cannot be any meaningful assessment. 2) If departments have identified specific learning goals, what is the priority of those learning goals? For example, in English the purpose of writing is to communicate ideas or feelings. Shouldn’t the organization of ideas be more important than the spelling? Or does spelling/grammar have the same assessment weight as organization? Likewise, in Modern Languages, are all skills (listening, speaking, reading and writing) treated equally in assessment weighting even though both in class and in the real world, people listen and speak almost double the amount that they read and write? Have the specific learning goals and their priority been communicated to the teachers/students through a department website/wiki? 3) The departments do not have exemplars that show the quality that they expect of students. Does the English department share electronically with all English teachers essays that show what constitutes a high level paper, an acceptable paper, and a non-acceptable paper? Again, are these exemplars on the department website for each course? Does the Modern Language department share audio files of a good ten sentence conversation through their website or an their department app? 4) They have vague assessment tools. The English department has a generic rubric (has good organization, conveys ideas, etc.) that can be interpreted differently by different people. What type of essay will be the written? An autobiographical essay requires a very different approach than a contrast essay. In Modern Languages, how will writing be assessed – holistically or analytically? If different educators can come up with different scores for the same student, then the assessment tool does not accurately measure learning. Teachers can receive a digital image of the rubric and work assessed using that rubric. How well does the assessment tool match up with how the information was taught in class? Is the assessment tool such as the final developed at the competency level or at the highly competent level? Students may be competent but not highly competent 5) The departments do not do a thorough analysis to get at the root problem once they have discovered a gap. If the students do not achieve well, was it due to the students’ lack of effort, a misunderstanding of how to answer the assessment question, a specific word in the assessment question, the thinking level of the test question, the structure of the assessment item, the textbook, the textbook’s powerpoints, the teacher’s explanation, the homework, or the online work? Usually much additional exploration is needed to determine the real reason for the gap. Once the department identifies the gap, what specific strategy will help the students over come this gap? Will the department suggest technology-based strategies that appeal to students such as Youtube videos, interactive websites, interactive apps and that help the students directly overcome the gap? 6) Most important of all, how does the institutional assessment help students improve in the course right now? Most institutions assess once a semester. After the analysis, the department focuses on what changes will happen in the future year. Unless regular assessment is done in small intervals throughout the year and changes made almost instantly, then the assessment does not benefit the present students. Next year’s students may be very different than the students who took this assessment. Classroom teachers need access to the online data and analysis so they can take class time to provide the students new learning strategies. Then, students can be successful learners! How does your institution assess student learning? My Spanish spontaneous speaking activities (20+) includes Modified Speed Dating (Students ask a question from a card-whole class), Structured Speaking (Students substitute in or select words to communicate in pairs), Role Playing (Students talk as people in pictures or drawing from 2-4 people) and Speaking Mats (Can talk using a wide variety of nouns, verbs and adjectives to express their ideas- pairs or small group), Spontaneous Speaking (based on visuals or topics in pairs), and Grammar speaking games (pairs or small group). Available for a nominal fee at Teacherspayteachers: http://bit.ly/tpthtuttle My three formative assessment books: http://is.gd/tbook
We constantly fret about external threats and foreign attacks — but its an entirely other level of concern when the offensive comes from outer space. Two close calls with asteroids earlier this year were a wake-up call about the threat space rocks pose to our planet. A 150-foot asteroid sideswiped the Earth at one-fourteeth the distance between our planet and the Moon. And that threat became real when a large meteor exploded over Russia on February 15th, injuring over 1,100 people from the damage by the shockwave. On Friday afternoon, an asteroid larger than both of those combined will make its closest approach to Earth at 4:59 EST on May 31st. The asteroid, named 1998 QE2, is 1.7 miles (2.7 km) in diameter. The moniker follows a coding convention from the US Minor Planet Center in Cambridge, Massachusetts. But the name just happens to describe its enormous girth at just over 9 times the size of the Cunard luxury liner Queen Elizabeth 2. In fact, it’s so large it’s been found to be carrying its own moon in tow. If an asteroid of this size hit Earth, the consequences could be devastating on a global scale. Fear not, though: this asteroid will speed by us at comfortable distance of 3.6 million miles. However, the distance is close enough for two powerful radar facilities to catch detailed images. Both the Goldstone radar telescope in California and the Aricebo telescope in Puerto Rico will bounce microwave signals off 1998 QE2. The returning radar echoes contain surface details and other rich data that will help NASA scientists learn more about 1998 QE2 and add to the general knowledge of other known near-earth objects.
The Standard Model of Particle Physics describes the fundamental particles and their interactions via the strong, electromagnetic and weak forces, providing precise predictions for measurable quantities that can be tested experimentally. Here’s the latest!! It’s hot!!! It’s exciting!!! At least, if you’re a particle physicist… Writing in Nature, physicists working on the CMS (Compact Muon Solenoid) and LHCb (Large Hadron Collider “beauty”) experiments at CERN – the Conseil Européen pour la Recherche Nucléaire – announced the discovery of a rare decay of the strange B-meson, as well as further information regarding an even rarer decay of the B0-meson. In both cases, the decays produce two oppositely charged muons. Quarks and Mesons In particle physics, mesons are hadronic sub-atomic particles composed of one quark and one antiquark, bound together by the strong interaction. Because mesons are composed of sub-particles, they have a physical size, with a diameter roughly one femto-metre (10-15 metre), which is about 2⁄3 the size of a proton or neutron. Mesons appear in Nature as short-lived products of very high-energy interactions between particles made of quarks. Unlike alpha-particles, mesons are not produced by radioactive decay. In cosmic ray interactions, such particles are ordinary protons and neutrons. All mesons are unstable, with the longest-lived lasting for only a few hundredths of a microsecond. Charged mesons decay (sometimes through intermediate particles) to form electrons and neutrinos. Uncharged mesons may decay to photons. Mesons are also produced artificially in high-energy particle accelerators that collide protons, anti-protons, or other particles. Now, B mesons are mesons composed of a bottom antiquark and either an up (B+), down (B0), strange (B0s) or charm quark (B+c) – the combination of a bottom antiquark and a top quark being assumed impossible because of the top quark’s exceedingly short lifetime. The Standard Model predicts that the , and decays are very rare, with about four of the former occurring for every billion B0s mesons produced, and one of the latter occurring for every ten billion B0 mesons. The probabilities, or branching fractions, of the strange B meson B0s and the B0 meson decaying into two oppositely charged muons (μ+ and μ–) are especially interesting because of their sensitivity to theories that extend the Standard Model. A difference in the observed branching fractions with respect to the predictions of the standard model would provide a direction in which the Standard model should be extended. The Standard Model of particle physics also predicts that both processes are very unlikely, and this means that both decays should be very sensitive to the existence of physics beyond the Standard Model. In other words, if the measured decay rates differ from those predicted by the Standard Model, this could provide important clues about some of physics most exotic mysteries, such as dark matter and the scarcity of antimatter in our Universe. Indeed, a deviation could even be an important milestone on the long journey towards a Theory of Everything that reconciles the Standard Model with the General Theory of Relativity. But before the Large Hadron Collider (LHC) at CERN started operating, no evidence for either decay mode had been found. Upper limits on the branching fractions were an order of magnitude above the Standard Model predictions. CMS and LHCb Collaboration The CMS Collaboration & LHCb Collaboration (2015) have performed a joint analysis of the data from proton-proton collisions collected in 2011 at a centre-of-mass energy of 7 TeV (tera-electronvolts), and in 2012 at 8 TeV. The particle physicists report the first observation of the decay, with a statistical significance exceeding six standard deviations – the best measurement so far of its branching fraction. They obtained evidence for the decay with a statistical significance of three standard deviations. Both measurements are statistically compatible with Standard Model predictions and allow stringent constraints to be placed on theories beyond it. The LHC experiments resumed taking data in March 2015, recording proton-proton collisions at a centre-of-mass energy of 13 TeV (tera-electronvolts), which will approximately double the production rates of B0s and B0 mesons and lead to further improvements in the precision of these crucial tests of the Standard Model. But the Standard Model holds, and the combined CMS/LHCb decay rate for the strange B-meson is just as predicted. The B0 decay rate also appears to fall in line with the SM. However, it is not yet deemed a “discovery” because the statistical significance of the measurement is only about 3σ – well short of the required 5σ. Dr Vakhtang Kartvelishvili who works on the ATLAS experiment at CERN, pointed out in a paper called “Particle physics discovery raises hope for a theory of everything” that the measured B0 decay rate is about four times larger than predicted by the Standard Model – while still being statistically compatible. The title reflects the hope in the particle physics community that important clues about physics beyond the Standard Model could soon be forthcoming at the LHC. So there are two possible scenarios: - If the Universe is kind to particle physicists, this discrepancy will endure as more data are collected on the decay in the upcoming runs of the LHC. - If the Universe is very unkind, you may get what some critics have called the “nightmare scenario of particle physics” in which physicists build increasingly energetic accelerators, yet never reach energies high enough to realise physics beyond the Standard Model. With collisions at 13 TeV at the LHC, we may not have to wait for long to see if a breakthrough is forthcoming… An animation of how the strange B-meson decay is detected by the CMS appears in the video below:
Photograph by Peg Skorpinski For biologist and herpetologist Tyrone Hayes, scientific breakthroughs don't begin and end in the laboratory. They also come from the field. Which is why, more often than not, you'll find Hayes wet, muddy, and knee-deep in an African swamp at 2 a.m., the time when the frogs come out. Hayes grew up in South Carolina, and, as a boy, one of his favorite pastimes was tracking down the region's abundant turtles, snakes, and toads. That abiding fascination led Hayes to earn an undergraduate degree in organismic and evolutionary biology from Harvard University. He later received a Ph.D. in integrative biology from the University of California, Berkeley, where he currently serves as a professor. Hayes says an interest in frog hormones, specifically those of a tiny reed frog common in Ethiopia and Uganda, sparked his interest in his current fieldwork. "Surprisingly, frog hormones are very similar, and in some cases identical, to human hormones," he says. "So what affects a frog may also affect humans." It was during a night in the boggy African bush that Hayes's flashlight revealed an unexpected discovery: Several members of the reed frog genus had changed color. Males, which are normally green, had taken on the reddish background and white spots of females. Seeking to understand why, Hayes arrived at a theory: During the metamorphosis from tadpole to adult, frogs are very sensitive to changes in their environment, including chemicals in the water or in their food supply. So the change in coloration indicated that the frogs' extremely thin, sensitive skin was reacting to contaminants in the water. Thousands of frogs later, Hayes and his research team have proved the theory correct. Reed frogs, indeed, serve as tiny red flags that can warn when dangerous, even cancer-causing chemicals are present in a water source. These harmful substances may contain or act like hormones, triggering the color transformation. Contaminants include plastic by-products, pesticides in crop sprays such as DDT, and synthetic hormones such as DDS. Because they cannot be broken down during sewage treatment, the toxins flow into marshes and lakes. "This is the same water people cook and bathe with," Hayes notes. "We've found developmental changes in tadpoles when water contains contaminants 50 times lower than what's allowed in U.S. drinking water. If chemicals in such low concentrations can impact amphibians, mammals may also be affected." Hayes realized his simple observation could have enormous practical applications: Reed frogs could become a low-cost way to test for water pollution in developing countries. Local residents would only need to raise the frogs in questionable water sources and observe their color as adults to check for contaminants. Hayes's findings reveal a crucial new link between conservation and health. Latest Explorer News - Video: “Toy” Drone Deployed in Ivory Investigation - Project Baseline: Conserving the Underwater World through Citizen Science and Reporting - The Arctic Is Changing … Or Is It? - Video: Inside Togo’s Voodoo Fetish Market - Hope for New England’s Offshore Treasures - Video: The Accepting Nature of Orphaned Baby Elephants - The Stunning Ways Driftwood Builds Landscapes - Prehistoric Sea Monsters Emerge From the Arctic Landscape - Fuzzy Nautilus Rediscovered and Filmed After 30 Years - Hunters Bagged 10,000 Lions in Africa Since 2003, Trophy Data Show What are Tyrone Hayes and the rest of the National Geographic Explorers up to? Meet the E-Team and learn about their projects in this interactive mural. In Their Words Surprisingly, frog hormones are very similar, and in some cases identical, to human hormones. Our Explorers in Action Meet female explorers who have pushed the limits in adventure, science, and more.
Physical Description Of Kangaroo. Kangaroos are not greatly bothered by predators, but when pursued by dogs, for instance, often head for water, standing submerged to the chest, and attempting to drown the attacker by holding him underwater. Another defensive tactic is to get their back to a tree and kick at their adversary with their clawed hind feet, sometimes with sufficient force to kill a man. Kangaroos have large, powerful hind legs, large feet adapted for leaping, a long muscular tail for balance, and a small head. Like all marsupials, kangaroos have a pouch called a marsupium in which their young complete their development after birth. Kangaroos are the only large animals to use hopping as a means of locomotion. The comfortable hopping speed for Red Kangaroos is about 20–25 km/h (13–16 mph), but they can hop as fast as 70 km/h (43 mph) over short distances. This fast and energy-efficient method of travel has evolved less in response to the danger of predators, but more because of the need to regularly cover large distances in search of food and water.
© LISA OVERHOLTZER In the northern basin of what is now central Mexico, not far from Mexico City, the ancient Otomí people lived on an island in the middle of Lake Xaltocan. From the 11th to the 14th centuries, the town of Xaltocan developed into one of several bickering city-states in the region that eventually succumbed to conquest by the Tepanecs, and was ultimately swallowed up by the Aztec empire. “Historical sources say the population fled,” says Christopher Morehart, an anthropology professor at Georgia State University. Oral history, recorded by the Spanish centuries later, describes a Tepanec conquest in the late 14th century that left Xaltocan empty. But the archeological record paints a different picture. Artifacts dug up from excavation sites indicate that houses were still occupied during the time when Xaltocan was supposedly abandoned. Most recently, evidence from ancient DNA has been thrown into the mix, suggesting that—at least in part—family lines became broken by Tepanec and, later, Aztec rule. © LISA OVERHOLTZERPart of Otomí practice was to bury family members under the patios adjacent to their homes. Deborah Bolnick, a professor at the University of Texas at Austin, and her colleagues obtained mitochondrial DNA from teeth and bone samples of 25 people interred at three households in Xaltocan. The residents range from babies to seniors, and radiocarbon dating suggests that some of the remains date from 1325 to 1475. Ten of the individuals lived in Xaltocan before the Tepanec conquest in 1395 and 15 afterward. The researchers screened the mitochondrial DNA to compare the diversity of lineages within pre- and post-conquest remains. The individuals all belong to one of the haplogroups A2, B2, C1, or D1, which are the most common lineages among Native Americans. Bolnick’s team found that D1 and B2 were more common before the conquest and that A2 and C1 became more prevalent afterward. They also found that there were no close relationships between the haplotypes within these groups before Xaltocan was sacked and the haplotypes present afterwards. “It’s certainly consistent with some kind of broad-scale demographic shift,” says Graciela Cabana, a molecular anthropologist at the University of Tennessee, who was not part of the study. Theodore Schurr, a professor at the University of Pennsylvania, says population turnovers have been seen in other regions of the world, such as prehistoric Siberia, but are often thought to be driven by climate and environmental forces. The Xaltocan findings, he says, seem to indicate more “about warfare and power and shifting alliances and the impact on the common population on the ground. So that then leads to, at least on the basis of the maternal lineages, some differences in the [haplo]types that are present pre- and post-conquest in this particular town.” An abandonment and repopulation of Xaltocan is also supported by Morehart’s studies of the ancient Mesoamerican method of growing foods in floating garden beds, a practice known as chinampa agriculture. These artificial island garden beds were constructed in shallow lakes to farm maize, beans, and other crops. “These chinampas date to the height of Xaltocan as an independent kingdom. In other words, after the supposed collapse or conquest of Xaltocan at the end of the 14th century, the chinampas were abandoned,” he says. But the researchers caution against using the genetic evidence to generalize about the behavior of the entire town. “My guess is there’s something else happening, some demographic change at the site, but maybe not a complete population replacement,” says Bolnick. It could be that only the elite citizens of Xaltocan fled, or that there was a reorganization within the community. “We also don’t know whether we could be looking at something that is idiosyncratic to these households,” says Deborah Nichols, an anthropologist at Dartmouth College. Evidence from ancient DNA suggests that—at least in part—family lines became broken by Tepanec and, later, Aztec rule. Bolnick further points out that her study only looked at the matrilines, and it’s possible that some continuity persisted among the male lineages. Cabana says there’s good reason for using mitochondrial DNA, however. There are multiple mitochondrial genomes in a cell, and ancient DNA is often degraded. “So for us to do studies that require a large population size, the only shot we have to do that is to go after mitochondrial DNA. By definition that limits the scope of the analysis to maternally derived DNA [in order] to make inferences about the population as a whole,” Cabana says. Bolnick says her group is now collecting data from the Y chromosome and from biparentally inherited markers, including 15 loci of short tandem repeats and the amelogenin locus, which can be used to determine the sex of the individual. Morehart says the genetic data is valuable in offering another line of evidence, in addition to the historical and archeological records, about the methods of conquest during this period. “This provides one line of data looking not just at historical change in Xaltocan, but also potentially some of the imperial strategies the Aztecs may have maintained in moving populations from here to there, something that we don’t know too much about archaeologically.”
Deciding what is and isn’t a planet is a problem on which the International Astronomical Union has generated a large amount of hot air. The challenge is to find a way of defining a planet that does not depend on arbitrary rules. For example, saying that bodies bigger than a certain arbitrary size are planets but smaller ones are not will not do. The problem is that non-arbitrary rules are hard to come by. In 2006, the IAU famously modified its definition of a planet in a way that demoted Pluto to a second class member of the Solar System. Pluto is no longer a full blown planet but a dwarf planet along with a handful of other objects orbiting the Sun. The IAU’s new definition of a planet isan object that satisfies the following three criteria. It must be in orbit around the Sun, have sufficient mass to have formed into a nearly round shape and it must have cleared its orbit of other objects. Pluto satisfies the first two criteria but fails on the third because it crosses Neptune’s orbit(although, strangely, Neptune passes). Such objects are officially called dwarf planets and their definition is decidedly arbitrary. In its infinite wisdom, the IAU states that dwarf planets are any transNeptunian objects with an absolute magnitude less than +1 (ie a radius of at least 420 km). Today, Charles Lineweaver and Marc Norman at the Australian National University in Canberra focus on a new way of defining dwarf planets which is set to dramatically change the way we think about these obects. The problem boils down to separating the potato-shaped objects in the Solar System from the spherical ones. What Lineweaver and Norman have done is show from first principles how this dividing line falls naturally between objects that are larger and smaller than 200 kilometers in radius. Their approach is simply to look for a potato-sphere threshold in images of bodies in the Solar System. The empirical evidence suggests that the threshold lies at about 200 km. Lineweaver and Norman then work out the material strength of these bodies in their early years when their shape was being determined. They calculate the other forces at work on these bodies, such as the gravitational forces and the forces associated with rapidly spinning bodies. It turns out that when viewed from this point of view, the 200 km threshold fits pretty well. Anything smaller than this would almost certainly not have been squeezed by forces large enough to mould it into a sphere. Anything larger, on the other hand, is sufficiently squeezed t form a sphere. Lineweaver and Norman’s conclusion is that dwarf planets are essentally anything larger than 200km in radius that have not cleared their own orbit of other bodies. Such a definition fits most objects in the Solar System but there are one or two oddities that don’t fit the bill. the asteroid Vesta, for example, is both potato-shaped and larger than 200km across. Lineweaver and Norman explain this away by suggesting that it may have been deformed by a collision relatively late on in life. The 200km threshold looks to be a sensible criteria that the astronomical community can rally around. The trouble is that it dramatically increases the number of objects that count as dwarf planets and that may not please everyone, particularly those who hanker for special treatment for Pluto. On the other hand, it makes Pluto the main representative of the dwarf planets, an important but poorly studied subgroup of bodies in the Solar System. That can only increase interest in this icy object. As astronomers are only too keenly aware, interest is more or less synonymous with funding. And, of course, that is the unspoken issue at the heart of the debate over what is and isn’t a planet. Ref: arxiv.org/abs/1004.1091: The Potato Radius: a Lower Minimum Size for Dwarf Plan
Welcome back to Messier Monday! Today, in our ongoing tribute to Tammy Plotner, we take a look at the M13 globular cluster, which is often referred to as the Great Globular Cluster in Hercules. Enjoy! In the 18th century, French astronomer Charles Messier began cataloging all the “nebulous objects” he had come to find while searching the night sky. Having originally mistook these for comets, he compiled a list these objects in the hopes of preventing future astronomers from making the same mistake. In time, the list would include 100 objects, and would come to be known as the Messier Catalog to posterity. One of these objects is M13 (aka. NGC 6205) a globular cluster located in the Hercules constellation. Located some 25,100 light-years away from Earth, this cluster is made up of 300,000 stars and occupies a region of space that measures 145 light-years in diameter. Given its sheer size and its location, it is often referred to as the “Great Hercules Cluster”. This 11.65 billion year old formation of stars is one of the most impressive globular clusters in the northern hemisphere. Containing over 300,000 stars packed into a 145 light year sphere, the center of this glorious object is 500 times more concentrated than its outer perimeters. And out of all of those stars there stands one stranger – Barnard 29. This spectral type B2 star is a young, blue star that M13 is believed to have collected during one of its tours around the Milky Way Galaxy. Other interesting finds include the 15 blue straggler star candidates and 10 other possible that have been spotted by the Hubble Space Telescope. The stars in the blue horizontal branch of M13 appeared to be centrally depleted relative to other stellar types and the blue stragglers in the combined sample are centrally concentrated relative to the older red giant stars. However, the Stromgren photometry work performed by Frank Grundah (et al.) suggests this is a normal occurrence in evolution. “We also note the existence of what appears to be two separate stellar populations on the horizontal branch of M13. Among other possibilities, it could arise as the result of differences in the extent to which deep mixing occurs in the precursor red giants.” In their 2002 study, “An aligned stream of low-metallicity clusters in the halo of the Milky Way“, astronomers Yoon and Lee declared: “One of the long-standing problems in modern astronomy is the curious division of Galactic globular clusters, the “Oosterhoff dichotomy,” according to the properties of their RR Lyrae stars. Here, we find that most of the lowest metallicity clusters, which are essential to an understanding of this phenomenon, display a planar alignment in the outer halo. This alignment, combined with evidence from kinematics and stellar population, indicates a captured origin from a satellite galaxy. We show that, together with the horizontal-branch evolutionary effect, the factor producing the dichotomy could be a small time gap between the cluster-formation epochs in the Milky Way and the satellite. The results oppose the traditional view that the metal-poorest clusters represent the indigenous and oldest population of the Galaxy.” As to how old M13’s stars are, there is more than one answer. According the work of R. Glebocki (et al), stellar rotation within Messier 13 can also play a role in how the stars age. As they state in their 2000 research study, “Catalog of Projected Rotational Velocities”: “Much theoretical and observational work about the role that rotation plays in stellar evolution has been done. Angular momentum is one of the fundamental parameters in the process of star formation as well as in early life of a star. A considerable amount of research has been done on the stellar axial rotational velocities. Clusters present unique possibility of determination of age of stars.” History of Observation: M13 was originally discovered by Edmond Halley in 1714. In his notes, he wrote of the cluster: “This is but a little Patch, but it shews it self to the naked Eye, when the Sky is serene and the Moon absent.” On June 1st, 1764, Charles Messier officially catalogued the star cluster as item 13. As he described it at the time: “In the night of June 1 to 2, 1764, I have discovered a nebula in the girdle of Hercules, of which I am sure it doesn’t contain any star; having examined it with a Newtonian telescope of four feet and a half [FL], which magnified 60 times, it is round, beautiful & brilliant, the center brighter than the borders: One perceives it with an ordinary [non-achromatic] refractor of one foot [FL], it may have a diameter of three minutes of arc: It is accompanied by two stars, the one and the other of the ninth magnitude, situated, the one above and the other below the nebula, & little distant. I have determined its position at its passage of the Meridian, and compared with the star Epsilon Herculis; its right ascension has been concluded to be 248d 18′ 48″, and its declination 36d 54′ 44″ north. It is reported in the Philosophical Transactions, no. 347, page 390, that Mr. Halley discovered by hazard that nebula in 1714: it is, he says, almost on a straight line with Zeta and Eta according to Bayer, a bit closer to the star Zeta than to Eta, & when comparing its situation between the stars, its place is rather close to Scorpius 26d 1/2 with 57 degrees Northern [ecliptic] latitude, it is nothing but a small patch; but one sees it well without a telescope when the weather is fine, and if there is no light of the moon.” Although Sir William Herschel would soon enough resolve it into stars and again by his son and many others, no one described the history of this object more eloquently than Admiral Smyth: “A large cluster, or rather ball of stars, on the left buttock of Hercules, between Zeta and Eta; the place of which is differentiated from Eta Herculis, from which it lies south, a little westly, and 3deg 1/2 distant. This superb object blazes up in the centre, and has numerous outliers around its attenuated disc. It was accidentally hit upon by Halley, who says, “This is but a little patch, but it shows itself to the naked eye, when the sky is serene, and the moon absent.” The same paper, in describing this as the sixth and last of the nebulae known in 1716, wisely admits, “there are undoubtedly more of these which have not yet come to our knowledge:” ere half a century passed, Messier contributed his 80 or 90 in the Catalogue of 103; and before the close of that century WH [William Herschel] alone had added to the above 6, no fewer than 2500; and his son, in re-examining these, added 520 more! In my own refractor its appearance was something like the annexed diagram; but I agree with Dr. Nichol, that no plate can give a fitting representation of this magnificent cluster. It is indeed truly glorious, and enlarges on the eye by studying gazing. “Perhaps,” adds the Doctor, “no one ever saw it for the first time through a telescope, without uttering a shout of wonder.” This brilliant cluster was discovered by Halley in 1714; and fifty years afterwards it was examined by M. Messier, with his 4-foot Newtonian, under a power of 60, and described as round, beautiful, and brilliant; but, “ferret” as he was in these matters, he adds, “Je me suis assuré qu’elle ne contient aucune étoile.” This is rather startling, since the slightest optical aid enables the eye to resolve it into an extensive and magnificent mass of stars, with the most compressed part densely compacted and wedged together under unknown laws of aggregation. In 1787, Sir William Herschel pronounced it “a most beautiful cluster of stars, exceedingly compressed in the middle, and very rich.” It has been recently viewed in the Earl of Rosse’s new and powerful telescope, when the components were more distinctly separated, and brighter, than had been anticipated; and there were singular fringed appendages to the globular figure, branching out into the surrounding space, so as to form distinct marks among the general outliers.” And so Messier 13 has been part of our imaginations for many years. And in 1974, a message was sent from Arecibo Observatory designed to communicate the existence of human life to hypothetical extraterrestrials. Known as the “Aricebo Message”, it was expected that this communique had a better chance of finding intelligent life since the odds of it existing within this massive cluster of stars was greater than elsewhere. Locating Messier 13: To locate M13, all one needs to know is the “Keystone” asterism of Hercules. While this lopsided rectangle isn’t particularly bright, once you understand where to find it, you’ll be able to spot it even under relatively light-polluted skies. Both Vega (in the constellation of Lyra) and Arcturus (in Bootes) are very bright stars and the keystone is about 1/3 the distance between them. Once you locate it, always remember that Messier 13 is on the leading western side – no matter what position Hercules may be in. By just generally aiming your binoculars in the center of the two stars on the western side, you can’t miss this big, bright globular cluster. When using a finderscope, aim slightly north of the center point and you’ll easily spot it as well. From a dark sky location, M13 can often be seen unaided as a small, fuzzy spot on the sky. And here are the quick facts on the Great Hercules Cluster to help you get started: Object Name: Messier 13 Alternative Designations: M13, NGC 6205, the “Great Hercules Cluster” Object Type: Class V Globular Cluster Right Ascension: 16 : 41.7 (h:m) Declination: +36 : 28 (deg:m) Distance: 25.1 (kly) Visual Brightness: 5.8 (mag) Apparent Dimension: 20.0 (arc min) We have written many interesting articles about Messier Objects here at Universe Today. Here’s Tammy Plotner’s Introduction to the Messier Objects, , M1 – The Crab Nebula, M8 – The Lagoon Nebula, and David Dickison’s articles on the 2013 and 2014 Messier Marathons.
A wind turbine is made up of two major components and having looked at one of them, the rotor blade design in the previous tutorial, we can now look at the other, the Wind Turbine Generator or WTG’s which is the electrical machine used to generate the electricity. A low rpm electrical generator is used for converting the mechanical rotational power produced by the winds energy into usable electricity to supply our homes and is at the heart of any wind power system. At the end of 2014, worldwide PV capacity reached at least 177,000 megawatts. Photovoltaics grew fastest in China, followed by Japan and the United States, while Germany remains the world's largest overall producer of photovoltaic power, contributing about 7.0 percent to the overall electricity generation. Italy meets 7.9 percent of its electricity demands with photovoltaic power—the highest share worldwide. For 2015, global cumulative capacity is forecasted to increase by more than 50 gigawatts (GW). By 2018, worldwide capacity is projected to reach as much as 430 gigawatts. This corresponds to a tripling within five years. Solar power is forecasted to become the world's largest source of electricity by 2050, with solar photovoltaics and concentrated solar power contributing 16% and 11%, respectively. This requires an increase of installed PV capacity to 4,600 GW, of which more than half is expected to be deployed in China and India. Wind turbines allow us to harness the power of the wind and turn it into energy. When the wind blows, the turbine's blades spin clockwise, capturing energy. This triggers the main shaft, connected to a gearbox within the nacelle, to spin. The gearbox sends that energy to the generator, converting it to electricity. Electricity then travels down the tower to a transformer, where voltage levels are adjusted to match with the grid. Geothermal energy - Just under the earth's crust are massive amounts of thermal energy, which originates from both the original formation of the planet and the radioactive decay of minerals. Geothermal energy in the form of hot springs has been used by humans for millennia for bathing, and now it's being used to generate electricity. In North America alone, there's enough energy stored underground to produce 10 times as much electricity as coal currently does. “California Looks to Stationary Energy Storage as a Solution to Peaker Plants” • Central California electric utility Pacific Gas & Electric is planning to replace three old natural gas power plants in its network with stationary energy storage installations from Tesla. California is looking to add 1.3 GW of storage to its power grid by 2020. [CleanTechnica] A: Modern solar panels typically last twenty to thirty years before there’s a noticeable increase in output loss. Most residential solar providers offer a 20- to 25-year warranty, but many such warranties only guarantee a certain power output (e.g., a guarantee of 80% output for twenty years). Carefully read through the fine print to make sure you understand the warranty and what it covers. Floating solar arrays are PV systems that float on the surface of drinking water reservoirs, quarry lakes, irrigation canals or remediation and tailing ponds. A small number of such systems exist in France, India, Japan, South Korea, the United Kingdom, Singapore and the United States. The systems are said to have advantages over photovoltaics on land. The cost of land is more expensive, and there are fewer rules and regulations for structures built on bodies of water not used for recreation. Unlike most land-based solar plants, floating arrays can be unobtrusive because they are hidden from public view. They achieve higher efficiencies than PV panels on land, because water cools the panels. The panels have a special coating to prevent rust or corrosion. In May 2008, the Far Niente Winery in Oakville, California, pioneered the world's first floatovoltaic system by installing 994 solar PV modules with a total capacity of 477 kW onto 130 pontoons and floating them on the winery's irrigation pond. Utility-scale floating PV farms are starting to be built. Kyocera will develop the world's largest, a 13.4 MW farm on the reservoir above Yamakura Dam in Chiba Prefecture using 50,000 solar panels. Salt-water resistant floating farms are also being constructed for ocean use. The largest so far announced floatovoltaic project is a 350 MW power station in the Amazon region of Brazil. Stop getting twisted!! Gold Plated Contacts Heavy 30 amp Per conductor slip ring total 180 amps....Great for even heavy 12 volt environment wind generators as used in our Cat 5 and Freedom II Dual PMA Turbines This rotating connector will be great for the wind generator. The current can be split up in DC applications by using two conductors to cut down on the resistance. If you have application specific questions feel free to ask me before buying. Has 3 mounting holes in collar and long wires for easy installation Shared Specifications Wires 6 Current 0~30A Voltage 600 VDC/VAC Max speed 250RPM Overall diameter 30mm Length 66mm Contact Material Precious Metal:gold-gold Contact Resistance <2mOhm Housing Material Plastics Torque 0.06N. Manufacturers often claim that their vertical axis turbine is better at extracting power from low speed winds. Unfortunately the laws of physics get in the way here: There is very little power in low speed winds. The blade of a vertical or horizontal type turbine is equally good at extracting that power, though with the vertical type the blades move at an angle to the wind where they do not extract energy for part of every rotation, adding drag and making a vertical type turbine just a little less efficient than a similar sized horizontal one. There is no advantage when it comes to low winds. With feed-in tariffs, the financial burden falls upon the consumer. They reward the number of kilowatt-hours produced over a long period of time, but because the rate is set by the authorities, it may result in perceived overpayment. The price paid per kilowatt-hour under a feed-in tariff exceeds the price of grid electricity. Net metering refers to the case where the price paid by the utility is the same as the price charged. It all started in Vermont in 1997. Our passion for protecting the environment led us to our mission: to use the power of consumer choice to change the way power is made. Today, as the longest-serving renewable energy retailer, we remain committed to sustainability every step of the way. By offering only products with an environmental benefit and operating with a zero-carbon footprint, we’re living our promise to the planet, inside and out. Conventional hydroelectricity works very well in conjunction with solar power, water can be held back or released from a reservoir behind a dam as required. Where a suitable river is not available, pumped-storage hydroelectricity uses solar power to pump water to a high reservoir on sunny days then the energy is recovered at night and in bad weather by releasing water via a hydroelectric plant to a low reservoir where the cycle can begin again. However, this cycle can lose 20% of the energy to round trip inefficiencies, this plus the construction costs add to the expense of implementing high levels of solar power. Several refineries that can process biomass and turn it into ethanol are built by companies such as Iogen, POET, and Abengoa, while other companies such as the Verenium Corporation, Novozymes, and Dyadic International are producing enzymes which could enable future commercialization. The shift from food crop feedstocks to waste residues and native grasses offers significant opportunities for a range of players, from farmers to biotechnology firms, and from project developers to investors. Flashing 6 Times: High temperature protection; Flashing 7 Times: PWM driving undervoltage/overvoltage; Flashing 8 Times: Internal voltage reference undervoltage/overvoltage; Flashing 9 Times: Sensor bias current error; Flashing 10 Times: Hardware zero passage detection failure. Noted that the above operations can only be performed with the power grid connected. In the United States, one of the main problems with purchasing green energy through the electrical grid is the current centralized infrastructure that supplies the consumer’s electricity. This infrastructure has led to increasingly frequent brown outs and black outs, high CO2 emissions, higher energy costs, and power quality issues. An additional $450 billion will be invested to expand this fledgling system over the next 20 years to meet increasing demand. In addition, this centralized system is now being further overtaxed with the incorporation of renewable energies such as wind, solar, and geothermal energies. Renewable resources, due to the amount of space they require, are often located in remote areas where there is a lower energy demand. The current infrastructure would make transporting this energy to high demand areas, such as urban centers, highly inefficient and in some cases impossible. In addition, despite the amount of renewable energy produced or the economic viability of such technologies only about 20 percent will be able to be incorporated into the grid. To have a more sustainable energy profile, the United States must move towards implementing changes to the electrical grid that will accommodate a mixed-fuel economy. Marine energy (also sometimes referred to as ocean energy) refers to the energy carried by ocean waves, tides, salinity, and ocean temperature differences. The movement of water in the world's oceans creates a vast store of kinetic energy, or energy in motion. This energy can be harnessed to generate electricity to power homes, transport and industries. The term marine energy encompasses both wave power – power from surface waves, and tidal power – obtained from the kinetic energy of large bodies of moving water. Reverse electrodialysis (RED) is a technology for generating electricity by mixing fresh river water and salty sea water in large power cells designed for this purpose; as of 2016 it is being tested at a small scale (50 kW). Offshore wind power is not a form of marine energy, as wind power is derived from the wind, even if the wind turbines are placed over water. The oceans have a tremendous amount of energy and are close to many if not most concentrated populations. Ocean energy has the potential of providing a substantial amount of new renewable energy around the world. The array of a photovoltaic power system, or PV system, produces direct current (DC) power which fluctuates with the sunlight's intensity. For practical use this usually requires conversion to certain desired voltages or alternating current (AC), through the use of inverters. Multiple solar cells are connected inside modules. Modules are wired together to form arrays, then tied to an inverter, which produces power at the desired voltage, and for AC, the desired frequency/phase.
HIV infection happens in three stages. Without treatment, it will get worse over time and eventually overwhelm your immune system. First Stage: Acute HIV Infection Most people don’t know right away when they’ve been infected with HIV, but a short time later, they may have symptoms. This is when your body’s immune system puts up a fight, typically within 2 to 6 weeks after you’ve gotten the virus. It’s called acute retroviral syndrome or primary HIV infection. The symptoms are similar to those of other viral illnesses, and they’re often compared to the flu. They typically last a week or two and then completely go away. They include: Nausea and vomiting Swollen lymph nodes A red rash that doesn’t itch, usually on your torso Doctors can now prevent HIV from taking hold in your body if they act quickly. People who may have been infected — for example, had unprotected sex with someone who is HIV-positive — can take anti-HIV drugs to protect themselves. This is called PEP. But you must start the process within 72 hours of when you were exposed, and the medicines can have unpleasant side effects. Second Stage: Chronic HIV Infection After your immune system loses the battle with HIV, the flu-like symptoms will go away. Doctors may call this the asymptomatic or clinical latent period. Most people don’t have symptoms you can see or feel. You may not realize you’re infected and can pass HIV on to others. This stage can last 10 years or more. During this time, untreated HIV will be killing CD4 T-cells and destroying your immune system. Your doctor can check how many you have with blood tests (normal counts are between 450 and 1,400 cells per microliter). As the number drops, you become vulnerable to other infections. Fortunately, a combination, or “cocktail,” of medications can help fight HIV, rebuild your immune system, and prevent spreading the virus. if you’re taking medications and have healthy habits, your HIV infection may not progress further. Third Stage: AIDS AIDS is the advanced stage of HIV infection. This is usually when your CD4 T-cell number drops below 200. You can also be diagnosed with AIDS if you have an “AIDS defining illness” such as Kaposi’s sarcoma (a form of skin cancer) or pneumocystis pneumonia (a lung disease). If you didn’t know you were infected with HIV earlier, you may realize it after you have some of these symptoms: Being tired all of the time Swollen lymph nodes in your neck or groin Fever that lasts for more than 10 days Unexplained weight loss Purplish spots on your skin that don’t go away Shortness of breath Severe, long-lasting diarrhea Yeast infections in your mouth, throat, or vagina Bruises or bleeding you can’t explain People with AIDS who don’t take medication only survive about 3 years, even less if they get a dangerous infection. But with the right treatment and a healthy lifestyle, you can live a long time.
First graders were reading about maps, so in STEAM they planned and designed a map of an imaginary community. First, we brainstormed places in a town and made a concept map. Next, students made a map on the Interactive Whiteboard. Then, they made a model of their town. Each group made a different building for our town. A big thank you goes out to Colteryahn Dairy who donated empty cartons for the buildings. Students programmed the BeeBots to go from one place in the town to another. They also learned about circuits and made “Squishy Circuits” with play dough, a battery pack and a light bulb. They put their “Squishy Circuits” in the buildings to light them up! See our learning in action in this video: During the 2nd Nine Weeks, Kindergarteners studied Bees in the STEAM Lab through hands-on coding. First, students worked together to create beehives out of donated cardboard tubes and tissue paper flowers. Each week students learned about the ways bees are helpful through short videos from Discovery Education. Then, students arranged their beehives and flowers on their BeeBot mat. Students took turns programming or “coding” the BeeBots to get them to model a task such as: - Getting Nectar- Going from the beehive to a flower. - Making Honey- Going from a flower to the beehive. - Pollination- Going from one flower to another flower. - Bee Dance- Going back to the beehive and doing a dance to communicate to the other bees where the flowers are. - Two Bees- The first bee goes from the beehive to the flower and and the second bee follows! Check out the video compilation of this project below, and be sure to check out your child’s See Saw Portfolio. (Don’t have a See Saw account? Email Miss Conroy at [email protected] to ask for one!)
What is influenza (the flu)? Influenza (with strains like swine flu, H1N1, avian flu, human flu) is a viral infection of the respiratory tract that is infectious. What are symptoms of the flu? Symptoms of the flu are similar to those of a cold but generally much worse in severity. Although the onset of the flu can come on quickly, most people who get the flu feel better within a week. • scratchy throat • fever 102º to 106° F • nasal drip or congestion • fatigue or a lack of energy • body aches • hacking cough • chest discomfort or pains • difficulty sleeping When is flu season? The Center for Disease Control and Prevention states that flu season typically begins in October and can last through May. However, you can get the flu at any time of the year. It is just most common between the months of October and May. How does the flu spread? The flu is contagious and most adults are able to spread the flu before they even have any symptoms. Children are thought to be contagious for longer periods of time. "People with flu can spread it to others up to about 6 feet away. Most experts think that flu viruses are spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Less often, a person might also get flu by touching a surface or object that has flu virus on it and then touching their own mouth or nose."* If you are sick, be aware of everything you touch and wash everything in hot soapy water. Stay home from work, schools, churches, meetings, gatherings of any sorts, to help stop the spreading of the flu. How can I avoid catching the flu? Even though the flu is contagious, there are ways you can avoid getting the sick this flu season. • Wash Your Hands: Keep germs at bay by washing your hands thoroughly and frequently with warm water and soap. Try to wash your hands for a full 15 seconds. • Healthy Diet: Eat nutritious food to help stave off the flu. Have an assortment of fruits, vegetables, grains, nuts, and fish. • Immune Supplements: Take immunity-booting supplements to keep your immune system in peak performance. • Rest: Get plenty of sleep. Your body should be well-rested so that your immune system is functioning properly. • Get a Flu Shot: Many local pharmacies offer low-cost flu shots that can help prevent you from getting the local strains of the flu. • Stay Relaxed: Stress can actually weaken the immune system. Take time out of your day to decompress if you need to. • Stay Hydrated: Drink plenty of fluids that help hydrate the body. Avoid drinks that dehydrate you like coffee, tea, and alcohol. • Avoid the Virus: Try not to touch surfaces that may be contaminated with the flu virus. Additionally, avoid close contact with people who are sick.
1.You are given the following data ...Find the correlation coefficient, r . 2.Imagine that the correlation between years of education and happiness scores is .31. Describe what this correlation indicates 3.Describe a research question that would use a one-way chi square analysis. Create some data and enter it into the cells for obtained frequency. What is your null hypothesis? What are your expected frequencies? 4.For question #3, what are your degrees of freedom? Calculate the chi square. Setting alpha at .01, have you found significance? Discuss your findings 5.Describe what a scatter plot would look like for each of the following correlations 6.Suppose we collected data on the number of students within four college majors (psychology, business, health sciences, liberal arts) and the number of students who want to get a particular type of degree (associates, bachelors, masters, doctoral). a.What type of statistical test will we be using? b.What is our null hypothesis? c.How many cells are there? d.How will we know if we have found significance? 7.Dr. H collected the following data where x represents the age at which the subject was married and y represents the age of the partner at the time of marriage. See attached document Correlations, null hypothesis, chi-square, scatter plots and coefficients are determined. A Complete, Neat and Step-by-step Solution is provided in the attached Excel file.
Largest craters on Earth[change \| change source] The five largest confirmed impact structures are: - Vredefort crater, South Africa: 300 km diameter, 2023 million years ago. - Sudbury Basin, Ontario, Canada: 250 km diameter, 1850 million years ago. - Chicxulub crater, Mexico: 170 km diameter, 65 million years ago. - Popigai crater, Russia: 100 km diameter, 35.7 million years ago. - Manicouagan crater, Quebec, Canada: 100 km diameter, 214 million years ago. There are some other suggested impact structures which are larger. It is a feature of the Earth that climate, weathering and plate tectonics removes most of the older features and events. In comparison, the Moon retains a nearly complete record of its past impact events. The implication is that the Earth once suffered a similar bombardment in its early history. This period is known as the Late Heavy Bombardment, because it occurred after the Earth and Moon formed. Largest unconfirmed craters[change \| change source] Any of these may or may not be meteorite craters: - Australian impact structure: Northern Territory, Australia: multiple rings 600 km, 545 million years ago at the Neoproterozoic/Cambrian boundary. - Shiva crater, Indian Ocean, west of India: ~600 km length, 400 km width, 65 million years ago. Obviously this is of high interest, because of the date. - Wilkes Land crater, Antarctica: 485 km. 250–500 mya. - Nastapoka arc, Nunavut/Quebec, Canada: 450 km. unknown - Ishim impact structure, Kazakhstan: 300 km. 430–460 mya. - Bedout, off-shore of Western Australia: 250 km, 250 mya. - East Warburton Basin, Southern Australia: 200+ km, 300–360 mya. Largest named craters in the Solar System[change \| change source] - North Polar Basin/Borealis Basin (disputed) – Mars – Diameter: 10,600 km - South Pole–Aitken basin – Moon – Diameter: 2,500 km - Hellas Basin – Mars – Diameter: 2,100 km - Caloris Basin – Mercury – Diameter: 1,550 km - Imbrium Basin – Moon – Diameter: 1,100 km Identifying impact craters[change \| change source] - A layer of shattered rock under the floor of the crater. This layer is called a 'breccia lens'. - Shatter cones, which are chevron-shaped impressions in rocks. Such cones are formed most easily in fine-grained rocks. - High-temperature rock types, including laminated and welded blocks of sand, tektites, or glassy spatters of molten rock. They may have relatively large amounts of trace elements that are associated with meteorites, such as nickel, platinum, iridium, and cobalt. - Microscopic pressure deformations of minerals. These include fracture patterns in crystals of quartz and feldspar, and formation of high-pressure materials such as diamond, derived from graphite and other carbon compounds, or varieties of shocked quartz. References[change \| change source] - Earth Impact Database - Frank Dachille. "Frequency of the formation of large terrestrial impact craters". http://adsabs.harvard.edu/full/1976Metic..11..270D. - Zeylik B. S.; Seytmuratova E. Yu, 1974: A meteorite-impact structure in central Kazakhstan and its magmatic-ore controlling role. Doklady Akademii Nauk SSSR: 1, Pages 167-170 - 'Largest ever asteroid impact' found in Australia. BBC News Science & Environment. - Glikson A.Y. et al 2015. Geophysical anomalies and quartz deformation of the Warburton West structure, central Australia. Tectonophysics 643, 55–72. - French B.M. 1998. Traces of catastrophe: a handbook of shock-metamorphic effects in terrestrial meteorite impact structures. LPI Contribution #954. Houston, Texas, USA: Lunar and Planetary Institute. - Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, - Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a high-pressure shock. - Sagy A.; Fineberg J.; Reches Z. (2004). "Shatter cones: branched, rapid fractures formed by shock impact". Journal of Geophysical Research 109: B10209. doi:10.1029/2004JB003016. http://web.cocc.edu/breynolds/classes/UO_Geol_353/shatter%20cones.pdf. - French, Bevan M. (2005). "Stalking the wily shatter cone: a critical guide for impact-crater hunters" (pdf). Impacts in the Field (Impact Field Studies Group) 2 (Winter): s 3–10. http://web.eps.utk.edu/~faculty/ifsg_files/newsletter/Winter_2005.pdf
- Student Worksheet - Bibliography/Resources EPISODE 21: Saga of Hope Directed by Juliann Blackmore A descendant traces two Icelandic families as their fortunes are made and broken in rural Manitoba at the turn of the century. - Founding the colony of New - Disappointment and consequences of broken dreams - Preservation of ancestral and cultural heritage - New Iceland - To learn how the Icelanders came to settle in Canada - To appreciate the precariousness of immigrant settlement - To understand how ancestral and cultural heritage are preserved - Draw a family tree to trace your ancestry as far back as possible. Piece together information about long-lost or distant ancestors by talking to living relatives. Try to extend the family tree beyond its current branches by doing a genealogical search on the Internet or through an archives located in your familys place of origin. - Write a personal essay/story/saga about your familys history. Interviewing the elder members of your family would be a good place to start in gathering good stories and important details. - Visit your school or local library and find a novel/movie about ethnic identity and ancestral heritage to read/view together as a class. Roots, by Arthur Haley is one suggestion. - Locate and visit the focal-point of a cultural communitysomething similar to the Tergesen store or a more formal organization or associationwhere you live. Find out what role it plays in preserving ethnic heritage. - Have a class show-and-tell where each class member brings in a family heirloom (book, bible, photograph, or any personal object) that has been passed down over generations.
A computer virus is a piece of malicious computer software (malware) which attempts to copy itself into existing executable files on a computer. By doing this, the virus hijacks the file's execution. Computer viruses generally attempt to destroy software and operating systems, but usually not before spreading themselves to other devices. Methods of transmission - Automatic replication: When an infected program is run, the virus also runs, searching the host computer for other programs to infect. - By email: viruses (and other kinds of malware) are often transmitted as email attachments. In some cases, scripts within a message can also be used to infect a device, if the E-mail client program is not configured to ignore scripts. - Misleading software: A "Trojan Horse" is a program which seems useful, but contains a virus or other malware. The main program may or may not perform as advertised, but the distributor knows it is infected. A Trojan Horse carried virus typically does not replicate itself but is spread when the user copies the program. In some cases, legitimate software may also be infected after release. Even though the software by itself is legitimate and safe, infected copies can be distributed to attack unsuspecting users. - Instant messaging: A direct computer-to-computer link required for instant messaging can be misused to deliver a virus. Configuring email software so that it never runs attached programs or embedded scripts is an easy way to stop email-transmitted viruses. This should be the default setting, especially for corporate systems. Computer users should also be aware that free games and other such scripts available on the Internet can be risky to use. Reputable software companies go to great lengths to ensure virus-free software, so it is wise to stick with these whenever possible. Using a designated computer (or virtual system) is a safer way to experiment with such higher-risk internet services. A virus is technically a type of software which acts very much like a biological virus; the term refers to a specific kind of malware which infects preexisting files. However, since virus attacks became well known before most other types malware attacks, many people use the term "virus" for any kind of malicious software. Although this is technically incorrect, it is common for someone to call anything unwanted, such as adware, a virus.
There are two basic schemes for connecting a load or generator in a three-phase circuit. The Y or "wye" connection joins neutrals of each phase at a common junction. The or "delta" connection is a triangle whose vertices form the buses, and there is no neutral bus. Examples of each connection scheme are shown in Figure 1. In the three phase circuit arrangements displayed in Figure 1, each leg is shown with an impedance. If the impedances are identical on each phase, then the load is said to be balanced. A three-phase source is balanced when each leg produces equal magnitude voltage, with phase difference between any two phases, as shown in Figure 2. By convention, the three phases are designated a, b, and c. If a phase is chosen as reference, then the balanced line-to-neutral voltages in a wye-connected generator will be This phase sequence is called abc or positive sequence, in which leads by , and leads by , as shown in Figure 3 on the left. An alternative arrangement is acb, or negative sequence, shown in Figure 3 on the right. The delta-connected generator does not have line-to-neutral voltages, of course. The voltages between phases, or line-to-line voltages, form a closed path around buses a, b, and c, and normally sum to zero, in the case of a balanced system. In a wye-connected generator, line-to-line voltages can be calculated from line-to-neutral voltages. The line-to-line voltages are greater in magnitude by a factor of , and they lead the line-to-neutral voltages by : This is illustrated in Figure 4, a phasor diagram of positive-sequence voltages for a balanced wye-connected generator. Example Problem B3.3.1 Find the positive sequence line-to-line voltages in the balanced wye-connected generator if the line-to-neutral voltages have a magnitude of 12kV, and phase a is the reference. Line currents in a three-phase system can be calculated from phase voltages and impedances. For a balanced system with a wye-connected load, the line current equations can be written as Figure 5 illustrates the line currents in a balanced wye-connected load. is the impedance per phase between the source and the neutral. Load currents in a balanced delta-connected system are calculated using this equation: Line currents always sum to zero in a delta-connected system because there is no neutral wire. Figure 6 illustrates the currents in a delta-connected load. Example Problem B3.3.2 Given a wye-connected load of impedance and balanced positive sequence source with , find the load currents. A capacitor is considered a generator of positive reactive power, and its function in the power system is to supply reactive power needed by inductive loads. It is desirable to operate with loads that are not highly inductive. By compensating such loads with a shunt capacitor, the source current and apparent power decrease, resulting in more efficient operation and better voltage regulation. Also, reduced current permits the use of smaller conductors, so a significant savings in equipment and wiring costs may be realized by keeping power factor close to unity. The practice of improving a lagging power factor by installing capacitors in parallel with an inductive load is called power factor correction. Example Problem B3.3.3 Draw the power triangle for a single-phase source which delivers 80 kW to a load at 0.7 pf lagging. If the source voltage is 480 V, calculate the current required by this load. Size the shunt capacitor required to reduce the power factor in Example Problem 3 to 0.9 lagging. This impedance contains resistive and inductive elements: After power factor correction, load impedance will be Note that a change in load impedance from to is accomplished by adding a capacitive reactance of . The corresponding capacitance is Now, examine the power triangle after power factor correction. The result is significantly lower reactive power requirement, with a reduction in load current.
A sonic boom is created when an object travels faster than the speed of sound. When an airplane reaches the speed of sound, it makes such an explosive noise it can be seen with the naked eye. This is often called "breaking the sound barrier." The visible part of a sonic boom is actually air that becomes squashed by sound waves. The thunder that a storm makes is also a sonic boom caused by lightning forcing air to move faster than the speed of sound. References[change \| change source] - "The Science of Thunder". Retrieved 2008-06-17.
The Top 10: Epidemic Hall of Infamy Historically speaking, these infectious diseases have been the deadliest, followed closely by other childhood diseases like diphtheria, as well as typhus and hepatitis B and C. 1. Influenza or “flu” Viral respiratory illness Spread: by tiny droplets from sneeze or cough Symptoms: fever, headache, fatigue, cough, sore throat, runny/stuffy nose, muscle aches and sometimes intestinal upset Best prevention: annual vaccination for seasonal flu Impact: Seasonal flu annually sickens about 5–20 percent of the U.S. population, sending 200,000 people to the hospital and killing 36,000 people. Note: Scientists fear a more serious influenza, currently found primarily in poultry and wild birds, might change into a more serious form, called pandemic influenza, that could easily pass from person to person as did the Spanish Influenza of 1918. Ancient disease caused by the variola virus Spread: person-to-person or via contaminated Symptoms: high fever and extensive rash; can cause permanent scarring or death Best prevention: was eliminated worldwide by an aggressive global vaccination program; last naturally occurring case reported in 1977 Impact: brought to the New World by explorers and settlers, devastating native peoples; killed about 300 million people in just the 20th century Note: Except for laboratory stockpiles, the variola virus has been eliminated, but the U.S. still prepares for a bioterrorist-caused outbreak. 3. Plague (bubonic and pneumonic) Caused by Yersinia pestis bacterium Spread: bites from infected fleas/rodents (bubonic) or by inhaling the bacteria through close contact with an infected person (pneumonic) Symptoms: (bubonic) swollen glands; (pneumonic) fever, chills, headache, extreme exhaustion, lung infection, breathing difficulty Best prevention: avoid contact with infected animals/fleas; antibiotics if exposure certain Impact: killed one-third of Europe’s population in 1348–50; today, World Health Organization reports 1,000–3,000 cases annually Note: Ten to 20 people in the U.S. develop plague annually from fleas or rodents, but the country’s last person-to-person infection was in 1924. A toxin-producing bacterial infection of the intestines Spread: contaminated food or water Symptoms: diarrhea, vomiting, dehydration, kidney failure Best prevention: sanitary water supplies and sewage treatment; early treatment with fluid replacement and, in severe cases, antibiotics Impact: In summer 1832, cholera killed more than 3,000 people in New York, then 4,000 more in New Orleans a few months later. With more than 120 countries reporting indigenous cases since 1991, cholera seems to be on the rise globally. In 2004, the World Health Organization said that 56 countries officially reported 101,383 cholera cases, including 2,345 deaths. Note: kills half of untreated people with severe cases but less than 1 percent of those who get prompt fluid replacement 5. Tuberculosis (TB) Caused by the Mycobacterium tuberculosis bacterium; TB usually attacks lungs; can affect kidney, spine and brain Spread: person-to-person through air Symptoms: bad cough, chest pain, coughing blood if bacterium settles in lungs Best prevention: good ventilation; skin tests to identify people carrying TB without obvious symptoms; treatment of those identified with active TB disease. Antibiotics can cure most cases. Impact: Two billion people—one-third of world’s population—are thought to be infected with TB bacteria. Annually, 8 million people worldwide develop active TB and nearly 2 million die. Note: TB was once the leading cause of death in Four kinds of malaria parasites can infect people Spread: bites from infected mosquitoes Symptoms: high fever, shaking chills and flu-like illness Best prevention: avoid mosquito bites; take regionally specific anti-malaria drugs Impact: Annually 300 million–500 million cases of malaria occur worldwide, killing more than 1 million people. Most of the 1,300 U.S. malaria cases each year are in travelers and immigrants returning from high malaria-risk areas. Note: Development of a malaria vaccine, not yet available, is a top international public health research priority. 7. AIDS (Acquired Immune Deficiency Syndrome) Caused by Human Immunodeficiency Virus (HIV) Spread: sexual contact, sharing needles/syringes with infected person, transfusions or mother-to-infant transmission Symptoms: damages immune system, progressively destroying ability to fight infections and certain cancers Best prevention: avoid unprotected sex or needle-sharing; combinations of antiviral drugs can slow spread of HIV in body and delay opportunistic Impact: Worldwide, AIDS is leading cause of death of 15-to-49-year-olds with cases totaling 45 million in 2005. Note: National Institute for Allergies and Infectious Diseases estimates 950,000 Americans are infected with HIV, one-quarter of whom don’t know it. 8. Yellow Fever Spread: by mosquitoes Symptoms: headache, fever, jaundice, kidney failure Best prevention: vaccination, avoiding mosquito bites Impact: common in rural sub-Saharan Africa and South America; Africa also experiences urban yellow fever outbreaks. In 2001, the World Health Organization reported there were 200,000 estimated cases of yellow fever, with 30,000 deaths, per year. Note: The last great U.S. epidemic occurred in 1878 in New Orleans, killing 13,000 people. Highly infectious viral disease Spread: person-to-person contact Symptoms: fever, fatigue, headache, vomiting, neck stiffness, pain in limbs; one in 200 infections leads to irreversible paralysis, killing 5–10 percent of those paralyzed when breathing muscles are affected; mainly strikes children under age 5 Best prevention: vaccination Impact: Until effective vaccines were developed in 1950s, polio annually crippled thousands of children in industrialized countries. Today only four countries worldwide remain polio-endemic: India, Nigeria, Pakistan and Afghanistan. Note: The worst U.S. polio epidemic caused more than 27,000 cases and 7,000 deaths in 1916. Highly communicable viral respiratory disease Spread: coughing and sneezing Symptoms: rash, high fever, cough, runny nose and red, watery eyes; complications include ear infections, pneumonia, encephalitis, seizures and death. Best prevention: measles vaccine Impact: About 454,000 people, mostly children, died from measles worldwide in 2004. Note: Before a vaccine became available in 1963, almost everyone got the measles. After the vaccine, U.S. cases dropped by 98 percent. Information for the Top 10 was drawn primarily from the Centers for Disease Control and Prevention, the World Health Organization and the National Institute of Allergy and Infectious Disease. — Pat Bailey Uniting Against a Possible Pandemic Predicting Future Epidemics A Big Look at Small Invaders Ducking Bird Flu and other Contagious Diseases Pat Bailey writes about the agricultural and veterinary sciences for UC Davis.
February 13, 2014 British Antarctic Survey Team Counts Whales Using Satellites Brett Smith for redOrbit.com - Your Universe Online A new report from the British Antarctic Survey has revealed that satellites can be used to accurately estimate whale populations. The report authors said the technique they developed could revolutionize the way whales are counted."This is a proof of concept study that proves whales can be identified and counted by satellite,” said study author Peter Fretwell, a researcher with the British Antarctic Survey. “Whale populations have always been difficult to assess; traditional means of counting them are localized, expensive and lack accuracy,” he continued. “The ability to count whales automatically, over large areas in a cost effective way will be of great benefit to conservation efforts for this and potentially other whale species." In the report, which was published in the open-access journal PLOS ONE, the researchers looked at one of the biggest right whale populations, which were mating off the coast of Argentina at the time. The population was chosen, due to its huge size and tendency to bask near the surface in large numbers around sheltered coastal oceans during mating season. Nearly driven to extinction, these right whales are seeing a limited recovery following the conclusion of whaling activities by the international community. However, many recent deaths have been seen in their nursery waters off the coast of Argentina. Their population is currently unknown, but with this sharp increase in calf fatalities, conservationists have been calling for accurate population estimates. To test the prospective of using high-resolution satellite imagery to find and count baleen whales, the study team used satellite imagery that covered 40 square miles and could penetrate farther into the water column than images off other satellites. The authors utilized four various automatic identification techniques and analyzed the results compared to those using manual whale detection methods. The manual methods used three main criteria to identify a whale: objects visible in the image should be the right configuration, they should be where whales would be expected to be and there should be very few similar objects that might be mistaken as whales. The manual counting revealed 55 probable whales, 23 possible whales and 13 sub-surface features. The automated counting method utilized light from the far blue end of the spectrum. This technique revealed 89 percent of probable whales identified in the manual count. The study authors concluded that these techniques are more effective than traditional techniques of determining populations of marine mammals. They added that this is one of the first successful research studies to use satellite imagery to count whales, a technique that might be applied to future surveys of various marine mammal populations. "Whales populations have always been difficult to assess, traditional means of counting them are localized, expensive and lack accuracy,” Fretwell said. “The ability to count whales automatically, over large areas in a cost effective way will be of great benefit to conservation efforts for this and potentially other whale species." The researchers noted that future satellites will provide even higher quality imagery and allow for greater confidence in not only finding whales – but also differentiating mother and calf pairs. Image Below: This is a satellite versus aerial view of southern right whales. Credit: British Antarctic Survey
The article below was a featured article on ezinearticles.com and they granted me an ‘expert author’ designation as a result. Renaissance Warfare and Weapons – Siege Tactics The era commonly known as “Early Modern Warfare” began during the middle of the fifteenth century and lasted until the end of the eighteenth century. The widespread use of gunpowder along with the weapons designed to use it, changed the methods of warfare dramatically. China had been using gunpowder for centuries before the European countries began using it. Cannons were the first common weapons to use gunpowder. But at the time, all weapons that used gunpowder were generally large, very heavy, required many men to deploy them and were unwieldy to say the least. Cannons first appeared in Europe during the late Middle Ages and their primary use was for attacking castles. The development of the siege cannon quickly made the use of castles and their tall walls, for your main defense obsolete. The siege cannon meant that the attacker was now favored to be the ultimate battle winner. As a result, the character of the defensive position had to be changed. The high castle walls gave way to slopping walls. These slopping walls would deflect the cannon shots and allow the primary defense mechanism, the wall itself, to remain intact. Castles with their tall and relatively thin walls became obsolete as a defense tool. The castles gave way to “fortresses”. These fortresses were built with thick slopping walls. To defend themselves, cities had to spend vast amount of money to build the new fortresses. These fortresses, with their ability to sustain cannon fire then brought back the “Siege” as the primary tactic for attacking a position. A siege is the assault of a city or fortress with the intent of winning through attrition, a more modern term is a “blockade”. When an attacker could not get the city or fortress to surrender and realizing that a direct frontal attack would not be successful would resort to the siege tactic. A siege usually meant the attackers would surround the target, either the city or a fortress with the intent of blocking the entry of supplies and provisions to the inhabitants. Common siege tactics were: 1. Mining or sapping Mining or sapping involved digging a tunnel under the walls of the castle or fortress. The mines would have wooden reinforced walls for support. Once complete the attackers would fill the mine with flammable materials and set it on fire. Later, with the use of gunpowder, the mines would be filled with explosives, which was a much more effective use of the “sapping or mining”. The purpose of the sapping, or mining was to bring down the wall over the mine and allow an entrance point for the attackers. 2. Artillery bombardment. Using everything thing imaginable to go over the wall of the fortress or castle and inflict harm. 3. The use of the siege engines. There are many types of siege engines. The general categories are ballista, battering ram, catapult, helepolis, mangonel, onager, siege tower and trebuchet. Ballista: This is a powerful weapon that resembles a giant crossbow. The purpose of the ballista was to throw heavy arrows. It could shoot the arrows one at a time or in groups. The ballista is also knows as a “bolt thrower”. In earlier times the Romans used the ballista to hurl large stones but during the Middle Ages the ballista was modified to throw arrows, which at the time were known as bolts. The crossbow is believed to have been inspired by the early ballista. The ballista was made of wood and used animal sinew as the rope or string. Winches were used to pull back (cock) the ballista. The ballista was a very accurate weapon when hurling bolts (arrows) but the accuracy was gained at the expense of range. The first known use of a ballista was in Italy in 400 B.C. The catapult was a natural evolution of the ballista. Battering Ram: Battering rams are devices used to break through fortification walls or doors. They have been in use since ancient time. The simplest form of a battering ram is a large heavy log carried by several attackers to hit the fortress or castle door or wall. The objective is to do enough damage to the wall or door to allow the attackers inside. A more efficient design of the battering ram was to use a wheeled frame to carry it. The battering ram was suspended by ropes or chains which allowed the ram to be much larger and be swung more easily. The sides and roofs of this improved type of battering ram were sometime covered with protective materials to keep them from being set on fire and to protect the attackers. Some battering rams were not suspended by ropes or chains but were placed on rollers instead. This would allow the ram to gain much higher speed and thus inflict much more damage. The writer Vitruvius described this type of rolling battering ram as used by Alexander the Great. To defend themselves from a battering ram the defenders would drop obstacles in front of the battering ram or use grappling hooks to immobilize the ram or set the ram and/or its frame on fire. Another defense was to simply launch an attack on the ram as it approached them. The use of battering rams can be traced to the destruction of Jerusalem and the fall of Rome. They were used throughout the Crusades too. Catapult: A catapult is a type of siege engine used to hurl a projectile a long distance. Catapults were not weapons that the attackers carried with them into battle and they were generally built on the battle site. They are made from wood and it was plentiful on most battlefields. The differentiation of differing types of catapults comes from the way they used to store and release their energy. The first type of catapult was a variation of the Roman ballista. These used rope or animal sinew to hurl the objects. The rope or sinew was pulled back under tension and when the tension was released the energy carried the projectile. So if the catapult stored and released the energy through tension, it is considered a tensional catapult. Another type of catapult is the torsion catapult. These have an arm with a bucket, cup or sling to hold the projectile. The force is transferred to the sling through the use of rope at the other end of the throwing arm. These ropes are placed are pulled tight to “load” the catapult with torsion energy. Another type of catapult uses gravity rather tension or torsion energy to throw the projectile. The Trebuchet is the most common of these types of catapults. Helepolis: This is an ancient type of siege engine and was known as the “Taker of Cities”. It was invented by Demetrius Poliorcetes for use during the siege on Salamis in Cyprus. The shape of the original helepolis was a tall square tower that was supported on four wheels. The helepolis was divided internally into nine different stories. The lower stories held machines used to throw projectiles (large stones). The middle section contained catapults for throwing darts (large spears). The top section was used for throwing smaller stones and smaller catapults. The helepolis was manned by two hundred soldiers and was propelled via a large drive belt and wheel inside the helepolis. The soldiers could propel the helepolis from the inside without having to take direct fire from the defenders. Mangonel: This type of siege engine is a catapult type used to throw projectiles at castle walls. The mangonel could hurl projectiles over great distances (1,300 feet). This is a much longer distance than the trebuchet, which was invented later. The mangonel was not very accurate and hurled the projectiles at a much lower angle than the trebuchet. The mangonel was a torsion arm catapult that used a sling to hold the projectile. The energy was stored by twisting ropes or sinew. In battles, mangonels hurled rocks, burning objects or just about anything else the attackers could think of. Vessels filled with flammable materials were popular and would create a large fireball upon impact. The most unusual object hurled by the mangonel was sometimes the dead and decaying carcasses of animals or people. These were used as psychological weapons to lower the morale of the defenders as well as to spread disease among the defenders. This was an effective tactic due to the poor conditions the besieged had to endure. Poor hygiene, food in short supply, living in cramped conditions and the abundance of vermin were all conducive to the rapid spread of disease. A variation of the mangonel was adapted to provide cover for troops in battle. This type of variation was first used by Alexander the Great. The shortcoming of the mangonel was it accuracy but it’s versatility and ease of maneuvering made it the most popular siege catapult during the medieval period. Onager: The onager is a torsion type of catapult. The torsion energy is stored by twisting ropes. The release of the energy provided a type of kicking action and thus the name onager which meant “wild ass”. The construction of the onager was pretty straightforward. It consisted of a frame which stayed on the ground. The front of the frame had a solid wooden vertical frame attached to it. The vertical frame had an axle running through it with a large single spoke protruding from it. In battle the spoke was pulled down via the use of twisted ropes or winched down to hold store the energy. When the energy was release the spoke would violently kick into the crosspiece of the vertical frame and the projectile would shoot forward. A variation of the onager is the mangonel. The mangonel used a bowl to hold the projectile instead of the sling and was less powerful than the onager. Siege Tower: This is a specialized siege engine used to protect the attackers as they approached the walls of the fortress or castle. These were often rectangular shaped and sat on four wheels. They were built to a height of approximately the height of the wall and sometimes even higher. When built higher than the wall the siege tower allowed archers to shoot into the castle or fortress. These were heavy and difficult to maneuver and were generally built on the battle site. They took a long time to construct and were used primarily when all other types of siege tactics had failed, like sapping or direct ladder assault. Its large size made it an easy target for the defender cannons upon approach. If the siege tower was successful, the last thing to do was to drop planks between the tower and the wall to allow the attackers to enter the fortress or castle. The outcome of a siege falls into one of these four categories: 1. If the defenders repelled the attackers without aid from outside forces then the position is deemed to have been “held”. 2. If the defenders repelled the attackers with the help of outside forces then the position is deemed to have been “relieved” or “raised”. 3. If the attackers succeed in taking the fortress, castle or city but the defensive forces are able to escape then the position is deemed to have been “evacuated”. 4. If the attackers succeed in taking the fortress, castle or city and they also destroy and/or capture the defenders then the besieged entity is deemed to have “fallen”.
Frida Kahlo and Expression Through Self-Portraits Lesson Plan Students learn about the Mexican painter, then create self-portraits while considering the question, "What is important to you?" - Grades: PreK–K, 1–2 - Unit Plan: The students will learn about Mexican artist Frida Kahlo. The students will brainstorm what is important to them, and then include these things in their own self-portrait. - Learn how to make a self-portrait - Learn about the life of Frida Kahlo - Smart About Art: Frida Kahlo, the Artist Who Painted Herself by Margaret Frith - Whiteboard or chart paper - Whiteboard markers or markers for chart paper - Print of The Frame by Frida Kahlo, along with several other self-portrait prints by Frida Kahlo - Mirrors, one per student - 9- by 12-inch white construction paper, one sheet per student - Frida by Jonah Winter - A ball of yarn - Construction paper in various colors, slightly larger than 9- by 12-inches Set Up and Prepare - Source the examples of Frida Kahlo self-portraits. An inexpensive way to get terrific prints of artists' work is to buy calendars, especially out-of-date calendars that are often sold at big discounts. - At the top of the whiteboard or chart paper, write: What Is Important to You? - Underneath the question, make a large capital T to divide the chart in half. - On one side of the T-chart, write "Frida Kahlo." On the other side write "Our Class." Step 1: Read the book Smart About Art: Frida Kahlo: The Artist Who Painted Herself by Margaret Frith. Brainstorm different things that were important to Kahlo. Write down the responses on the T-chart under her name. Step 2: Tell the class that Kahlo is known for her self-portraits. Ask the class what a self-portrait is. Bring out more prints of Kahlo's self-portraits to show the class. Step 3: Give each student a mirror. Invite them to look at themselves in the mirror. The students may partner up with a buddy to tell each other what color his/her hair is, what color his/her eyes are, what the shape of his/her face and eyes are, etc. Step 4: Invite them to start drawing themselves! (Head and shoulders only.) Use a pencil to model for the students how to make a big circle or oval on the white construction paper for the face. Draw eyes, nose, mouth, and ears. I give different examples on the board for how to draw the parts of a face. Draw a neck and then the shoulders going down to the bottom of the page. Step 1: Read the book Frida by Jonah Winter. Discuss the story and add responses to the T-chart about what was important to Kahlo. Step 2: Continue self-portraits with mirrors. Model for students and lightly outline all the pencil marks with a brown crayon. Invite students to add color to their self-portraits with crayon. They should add color to the skin, eyes, mouth, hair, and eyebrows. Step 1: Revisit the stories about Kahlo, reviewing the things that were important to her. Now have the students think about what is important to them. Step 2: Complete the T-chart with the Weave a Web activity. Weave a Web Activity - Divide the group in half. Send half of the students to classroom centers or to work on individual assigments. - Instruct the remaining half of the students to sit in a circle. - Pose the question, "What is important to you?" to one student. - Write the student's answer on the "Our Class" side of the T-chart. - Now instruct him or her to toss the ball of yarn to the person sitting opposite, without letting go of the yarn. - Repeat steps 3-5 for each student. - Once all of the students have shared and received a part of the yarn ball, it should look like a spider web. Invite each student to, one at a time, drop his or her string. - Discuss what would happen if we didn't work as a group — the answer is that everything would fall apart. Step 3: Switch groups and do the same Weave a Web activity with the students who were at centers. Step 4: Continue self-portraits by having the students draw pictures of what is important to them on the outside area of their self-portraits. Step 1: Have the students fill in all the white areas on their self-portraits. Invite them to add more color and detail to the pictures. Step 2: Mount the kids' self-portraits onto construction paper that is larger than the portraits, thereby forming a frame. Step 3: Have the students tell you what is important to them. Type up their responses and add the dictation to the bottom of the picture. Step 4: Display the self-portraits so everyone can see the students' beautiful artwork. Supporting All Learners For my English-language learners: I pair them with an English-only model to work with and sit next to. If my English-language learner is having trouble responding to the question about what is important to them, I let them point to a picture or a real object. For my more advanced learners: I add a writing component. Ask them to write about what is important to them. - Read the book Diego by Jeanette Winter to learn about Diego Rivera and his artwork. Create a story based on Rivera's murals and paintings, for instance, The Flower Vendor. - Paint a class mural. - Create a Venn diagram about Diego Rivera and Frida Kahlo. Invite the parents in to see the students' self-portraits. Suggest that families begin kindergarten scrapbooks for their children. - Create a self-portrait at home. - Name all the things that are important to them around the house. - Name all the parts of the face. Were the students able to work independently while drawing their self-portraits? Did the students have difficulty with the concept of a "self-portrait"? - Can the students express what is important to them? - Can the students draw and color themselves with their true attributes? - Can the students tell one fact about Frida Kahlo? - Can the students identify what a self-portrait is?
Learning how to read a clock is a very important skill that all children must learn. Learning to tell time is a skill that is covered in the early years, however many children do not master this skill. It is important that parents get involved in the process of helping children learn how to tell time on both an analog and a digital clock. There are many different technology tools that can be utilized to help your child learn how to tell time. Time Monsters is an online animated site for children to learn time. The main character, Professor Tempo leads children through the skills of learning to tell time broken down starting with learning the hour numbers on the clock and ending with reading the minute hands. Each skill has its own animated story lead by Professor Tempo provides an overview of the skill and then a hands-on activity. Without even saving, each time you go back to the site it will start your child where they left off. Quizzes and printables are also provided on this site. Apples for the Teacher – Learning Time Apples for the Teacher has an online interactive quiz to help children to practice telling time by comparing a digital clock to an analog clock. This is a good activity for older children who are struggling with telling time. Another game that they offer, clock practice, has children drag the hour and minute hands to match the time that is represented in the question. Both of these sites can be used for practice, after the skills have already been taught. Live in Nanny Blog – 10 Fun Ways to Teach Kids to Tell Time The blog, Live in Nanny, has informative articles based on education and raising a child. A recent post includes many great ideas to help children to learn how to tell time. Her ideas include songs, games, books, toys, videos, crafts, and online reinforcement. Each topic contains a link to an example. The YouTube video, “Hip Hop Around the Clock”, was really catchy teaching children to learn time through song, technology, and visual representation. Flik-Flak Telling Time Watches Flik-Flak is a brand of analog wrist watches specifically designed for young children to learn how to tell time. The hour, minute, and second hands are very prominent and different colors on the watch face. This helps the children to be able to determine which hand is used to tell the hour, minute, and second. On their website, Professor Flik, guides children through learning how to read their watch with the characters Flak (the hour hand) and Flik (the minute hand). The site also has an online game for children to practice their time telling skills with Flik and Flak. The child has to be able to read the analog clock and then enter its digital value. Providing your child with their own wrist watch is a great way to have them practice at home. Teaching children to learn how to tell time is both a school and a home activity. There are many ways a parent can get involved in teaching children to tell time through the use of technology and online resources. Article By Laura Ketcham-VanHellemont Picture By azmichelle Free Educational Resources by SmartTutor.com
Theaters in the Eighteenth and Nineteenth Centuries The development of a middle-class audience in 18th-century France and England created a desire for more realistic settings and acting. Although some attempts were made in the 18th cent. (notably by David Garrick in England and Adrienne Lecouvreur in France) to combat the artificial, rhetorical style of acting then popular, it was not until the late 19th cent. that a more natural style of acting gained wide acceptance. Of great importance in the development of realistic acting was Constantin Stanislavsky, cofounder of the Moscow Art Theater, who stressed the actors' absolute identification with the characters they portray. Similarly, realism in scenery and costumes was not popular until well into the 19th cent. The creation of realistic effects was facilitated by the introduction of gas lights in the early 19th cent. and of electricity later in the century. Electric lighting was, however, also used for antirealistic effects by such scene designers as Adolphe Appia and Edward Gordon Craig. The introduction of gas lighting made it possible to dim the auditorium lights, a practice that tended to make the audience more separate from the stage. Richard Wagner, in his opera theater at Bayreuth, attempted further to isolate the audience by means of a gap of darkness between a double proscenium arch. While most commercial theaters today still use the proscenium arch stage, there has been much experimental work to restore a vital relationship between audience and stage. By the late 19th cent., theater was dominated by commercial playhouses in large cities, particularly in England and the United States. However, in the late 19th cent. several independent theaters, more interested in art than in making money, came into being, including the Théâtre Libre in Paris (1887), the Freie Bühne in Berlin (1889), the Independent Theatre Society in London (1891), and the Moscow Art Theatre in Russia (1891). Sections in this article: The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved. More on theater Theaters in the Eighteenth and Nineteenth Centuries from Fact Monster: See more Encyclopedia articles on: Theater
Pronunciation in British English[change \| change source] In the United Kingdom, many different people say words in different ways. For example, a man from a place near London may not pronounce his "r"s the same as a man from Scotland or a man from Northern Ireland. Across the country, the accent is different. For instance, in Liverpool, one speaks with a "scouse" accent, and in London, one speaks with a "cockney" accent. Different variations on all of British English exist from the manner in which words are pronounced to the manner in which they are spelt. One place people speak English in a different way is Cornwall, where the Cornish dialect is spoken. Other languages[change \| change source] Britain, like other countries, has languages other than English. In Wales many speak Welsh; in Scotland some people speak Gaelic, and in Ireland a few people speak Irish. However, that is not the subject of this particular article. Spelling in British English[change \| change source] British English often keeps more traditional ways of spelling words than American English. - Some British English words end in "re", because the words were originally taken from French. They are often simplified to "er" in American English - British English: centre, litre, metre. - American English: center, liter, meter. - Some British English words end in "our" and are simplified to "or" in American English. The English spelling also came from the French language. - British English: colour, favour, honour, labour - American English: color, favor, honor, labor - Some British English words the have come originally from the Greek language use "ph". This has been changed to "f" in some other languages. - British English: Sulphur - American English: Sulfur - Some words in British English use "s" where "z" is used in American English. However, spelling them with "z" is also done in Britain sometimes. - British English: colonisation, realisation, organisation - American English: colonization, realization, organization - The word "gray" is also a special case, as it is normally spelled "gray" in American English and "grey" in British English. However, "gray" is also used in Britain, and "grey" is also used in America. - Many of these rules are also used in other countries outside of the United Kingdom, mostly in countries that are members in the Commonwealth of Nations. Vocabulary in British English[change \| change source] In British English, "dock" refers to the water in the space between two "piers" or "wharfs". In American English, the "pier" or "wharf" could be called a "dock", and the water between would be a "slip". Some common differences: British – American - accelerator – throttle[source?] - autumn – fall - biscuit – cookie - bonnet – hood (of a car) - boot – trunk (of a car) - bum – butt - caravan – trailer, mobile home - chips – French fries - courgette – zucchini - crisps – chips - face flannel – washcloth - flat – apartment - football – soccer - garden – yard - handbag – purse - jumper – sweater - lift – elevator - lorry – truck - manual gearbox – stick shift - metro, underground, tube – subway - motorway – freeway - mum – mom - nappy – diaper - number plate – license plate - pants - underpants - pavement – sidewalk - pram – stroller - petrol – gas or gasoline - phone box - phone booth - post – mail, mailbox - railway – railroad - shifting – moving - shopping trolley – shopping cart - surname – last name - take-away – take-out - trousers – pants - to let – to rent - torch – flashlight - tram – streetcar Usage in different countries[change \| change source] American English is only an official language in the United States. In Canada, the accent sounds extremely similar to American English but with few exceptions (see Canadian English). The American spelling in Canada is sometimes used, but traditionally, the British Spelling (with the exceptions of some words like programme, -isation/-ise/-isable, chilli, etc.) is used. Although Commonwealth English is the most spoken, American English is seen more often on the internet. American English vocabulary dominates the visual media: "movies" (British: "films") and television. All Commonwealth nations and Africa learn Commonwealth English, while American English is often learnt in the Americas and China. Z pronounced 'Zee' is only seen in the U.S.A and less commonly in Canada, while Z pronounced 'Zed' is spoken almost everywhere else. The United Kingdom and Ireland use British layout keyboards, while Australia, South Africa, Canada, New Zealand and the U.S.A use American layout keyboards. In continental Europe English as a second language is nowadays sometimes even taught in American English, except perhaps in Scandinavia and the Netherlands.
The ants in these photographs have fallen victim to parasitic fungi which manipulate the behaviour of their host in order to increase their own chances of reproducing. The spores of the fungus attach themselves to the external surface of the ant, where they germinate. They then enter the ant’s body through the tracheae (the tubes through which insects breathe), via holes in the exoskeleton called spiracles. Fine fungal filaments called mycelia then start to grow inside the ant’s body cavity, absorbing the host’s soft tissues but avoiding its vital organs. When the fungus is ready to sporulate, the mycelia grow into the ant’s brain. The fungus then produces chemicals which act on the host’s brain and alter its perception of pheromones. This causes the ant to climb a plant and, upon reaching the top, to clamp its mandibles around a leaf or leaf stem, thus securing it firmly to what will be its final resting place. The fungus then devours the ant’s brain, killing the host. The fruiting bodies of the fungus sprout from the ant’s head, through gaps in the joints of the exoskeleton. Once mature, the fruiting bodies burst, releasing clusters of capsules into the air. These in turn explode on their descent, spreading airborne spores over the surrounding area. These spores then infect other ants, completing the life cycle of the fungus. Depending on the type of fungus and the number of infecting spores, death of an infected insect takes between 4-10 days. The carpenter ant in the photograph on the right has been infected by Cordyceps unilateralis, which is but one of thousands of species of entomopathogenic fungi, more than 400 of which belong to the Cordyceps genus. Between them, these parasitic fungi infect at least nine different orders of arthropods, including the Odonata (dragonflies and damselflies), Blattaria (cockroaches), Hemiptera (aphids, cicadas and leafhoppers), Coleoptera(beetles), Phasmida (stick insects), Hymenoptera (ants, bees and wasps), and Lepidoptera (butterflies and moths). The host range of an individual species is, however, restricted to one species or to a small number of closely related species. Because they are considered as environmentally safe, natural mortality agents, entomopathogenic fungi are used as biological pesticides to control pest species. For example, Metarhizium anisopliae was first used over 100 years ago to try and control the wheat grain beetle Anisoplia austriaca. More recently, researchers have investigated the use of Metarhizium anisopliae, a species which infects the African mosquito Anopheles gambiae, to control the spread of malaria. Entomopathogenic fungi are not the only parasites that can modify the behaviour of their hosts. Equally remarkable is the nematomorph hairworm Spinochordodes tellinii, which is also known as the horsehair worm or the gordian worm, because of its resemblance to the knot created by the Phrygian king Gorius. (According to myth, Gordius used his knot to tie a chariot to a pole, and declared that whoever could untie it would rule all of Asia.) The juvenile gordian worm parasitizes land-living arthropods such as grasshopers, locusts and beetles, but the adult is a free-living aquatic species which can only reproduce in water. Inside the host, the microscopic larvae feed on surrounding tissue, and develop into long worms which can reach up to 4 times the length of the host, and which remain within the body cavity of the host as a long, coiled mass. After metamorphosing, the adult worm induces its host to leave its terrestrial habitat, and to commit suicide by jumping into water and drowning itself, so that the worm can emerge. David Biron and his colleagues have used proteomics to characterise the proteins synthesized by the gordian worm in order to determine how it manipulates its host’s behaviour. They have established that the worm synthesizes proteins which mimic those produced by the insect. These include proteins of the Wnt family, which are involved in the development of the nervous system, as well as others which interfere with the neurotransmitter systems involved in the host’s geotactic behaviour (its oriented movements in relation to the Earth’s magnetic field). Because the genes encoding these proteins are contained in the worm’s genome, but have a direct effect on the insect’s central nervous system when they are expressed, the relationship between the gordian worm and its host is an example of what Richard Dawkins called the extended phenotype, whereby genes expressed by one organism have an effect on the appearance or behaviour of another. (Entomopathogenic fungi and their hosts are also an example of an extended phenotype.) Incredibly, the gordian worm can survive predation on its host. Parasites use various strategies to survive host predation. For example, some develop quickly, in order to emerge from the host before it is preyed upon. Grasshoppers and crickets are preyed upon by fish and frogs; the gordian worm can escape this predation by wriggling out of the mouth, nose or gills of the predator once it has emerged from a host that has been eaten. Biron, D. G., et al (2005). Behavioural manipulation in a grasshopper harboring hairworm: a proteomics approach. Proc. R. Soc. B. 272: 2117-2126. [Full text] Thomas, F., et al (2003). Biochemical and histological changes in the brain of the cricket Nemobius sylvestris infected by the manipulative parasite Paragordius tricuspidatus (Nematomorpha). Int. J. Parasitol. 33: 435-443. [Full text]
Suffixes: word endings (ed, ing) Prefixes and suffixes are structural changes added to root words. Common endings that begin with a vowel (-er, -est, -ing, -ed, able) are usually sounded as syllables. A syllable is a vowel or a group of letters containing a vowel sound which together form a pronounceable unit. All words include at least one vowel. Spelling Rule: (Applies to words that have one syllable). When a short vowel is followed by one consonant at the end of the root word, double the last consonant and add (ed) or (ing). To state this rule simply; “short vowel, one consonant, double” (It needs a friend) Example: The letter “u” is a short vowel in the word run. It is followed by one consonant (n), therefore the last letter (n) is doubled - running. If the short vowel is followed by two consonants (mp), as in the word jump, the last consonant is not doubled - jumping. Read these words (verbs) “Verbs" are action words or words that show movement *Words (verbs) ending with the letter “x” are not doubled because the letter “x” is a blend of two consonants “ks”If the short vowel is followed by two or more consonants (mp), as in the word jump, the last consonant is not doubled - jumping. Dictation/Spelling Practice for Suffixes Do you recall the spelling rule regarding the root word + ending? “short vowel, one consonant, double” (the last consonant) “short vowel, two or more consonants, do not double" (the last consonant) Read these sentences. - His dog begged for my snack. - Did the glass crack when you dropped it? - The rabbit hopped into the bushes. - I hugged my mom and dad when they left the park. - I like to go shopping with my mom. - We stopped and petted the dogs. - I was running very fast when I got tagged. - I helped my dad do a trick. - We kicked a tin can and then rested on the grass. - The man milked a big black yak. - My back itched so much I had to scratch it. - I asked my mom to come and help me. Create a sentence that includes at least one base word + (ed), (ing). Your writing should reflect good penmanship, proper spacing, and correct usage of upper and lowercase letters. Remember all sentences begin with a capital letter and end with a period (.), question mark (?), or exclamation point (!). This portion of the lesson is meant for exposure. The student should revisit this page after he/she has completed lesson (#22, long “e”). Mastery in regard to reading should easily be achieved after the student has completed all the lessons. The suffixes (–ly) added to a base/root word changes its meaning. Sometimes it changes the way the word is used. Words ending in “–ly” normally tell how or how often something is done.Words ending with the suffix –ly (sounds like long e)
In a coal mining area around Katowice in Southern Poland, a team of scientists have been set to work. However, rather than extracting coal, they are using a mine to experimentally assess an alternative method to energy production: introducing steam and oxygen to coal produces hydrogen. This experiment is being carried out as part of the EU research project HUGE (Hydrogen Oriented Underground Coal Gasification for Europe). Hydrogen can be used to power gas turbines, heat boilers and for a synthetic fuel. But its production in the depths of the coal pits is, at this experimental stage, complex and risky. Firstly, a tank delivers liquid oxygen to the site of the mine. The liquid oxygen is allowed to flow into a secure pool, where it expands and evaporates into a gas. Control valves guide the gas through pipes into the mine, direct to the coal deposits, where the gasification process begins. The experiment is carefully monitored with sensors and underground cameras, on the search for irregularities. Monitoring methods are a vital part of the research; while the coal undergoes gasification various dangerous and explosive gases are produced. So measures must be taken to ensure that there are no explosions or leaking of dangerous gases. Monitoring is also done from the surface by geologists and chemists, 25 metres above where the gasification occurs. The researchers want to be sure that gas does not leak through porous soil layers. They use a georadar to see if there are any structural changes in the underground cavity. They also check for possible gas leakages. Another city with a long history of coal mining is Liege, in Belgium. It was here that coal gasification was investigated in a laboratory before beginning the full-scale experiment in Poland. The coal in a mine is not fully exposed, so to recreate the inside of a coal mine realistically, pieces of Polish coal were mixed up with a neutral material. The mix was then placed within the laboratory reactor, where different gases were introduced at different temperatures and pressures. These parameters control just what happens during the gasification process: for example, a higher pressure yields more methane, while a higher temperature yields more hydrogen and carbon monoxide. The technique of chromatography was used to analyse the resulting gases. There are three types of coal gasification: gasification with carbon dioxide gives a gas high in carbon monoxide, gasification with steam gives a gas high in hydrogen, and gasification with hydrogen will produce a gas with a high methane content � forming the base of synthetic natural gas found in energy networks. In Poland the experiment has been running successfully during a three week period. About 50 kg of coal has been gasified per hour without any traces of a dangerous leak. The researchers have been sampling and analysing the resulting hydrogen and other gases. Chromatography is used to identify the various gas components: carbon dioxide, carbon monoxide, hydrogen, nitrogen, oxygen, and some pollutants, like sulphur compounds, for example. Further research will most likely focus on improvements to increase the production rate of hydrogen and decrease the levels of dangerous gases. Gasification has the great advantage of also utilizing the smaller deposits of coal that are traditionally overlooked. This automatically increases the economic potential within a mine and could give new life to struggling coal regions within Europe. Furthermore, with less waste of coal, more energy will be produced in a more environmentally-friendly manner.
Women Making Shells 1919 The large and atmospheric canvas Women Making Shells by Henrietta Mabel May (1877–1971) depicts a noisy, machine-filled shell factory in Montreal. In 1918, when the Canadian War Memorials Fund commissioned a painting of women’s munitions work from May, the organizers obtained permission for her to sketch in the Canadian Pacific Railway Angus shops and the Northern Electric plant. As she was a prominent member of Montreal’s art scene, known for her industrial landscape and harbour scenes, the subject of women’s wartime labour suited her skills and interests. Although many women were employed in factory work before the war, following its outbreak approximately 12,000 women entered the munitions workforce, making them among the most highly visible of wartime female workers. Depictions of these workers were popular, appearing in film, photography, and print propaganda as well as art. It was dangerous work, owing to the chemicals. Many women fell ill with toxic jaundice as the chemical Trinitrotoluene used in shell manufacturing turned their skin yellow. It also affected their hair colour and caused liver damage. Women Making Shells displays May’s interest in Impressionism: the scattered light and textured brushwork highlight her subject and link the painting to Halifax war works such as Convoy in Bedford Basin, c.1919, by Arthur Lismer (1885–1969) and The Convoy and The Entrance to Halifax Harbour, both 1919, by A.Y. Jackson (1882–1974). These war canvases reinforce the conclusion that the war work completed in Canada by Canadian artists was generally more advanced in approach than the more documentary works they painted overseas. Arguably, for Jackson, the Halifax setting of rippling, reflective water and big skies framing dazzle-painted ships permitted a more modern approach, in contrast to the flattened, mud-drenched battlefields under lowering skies, which recalled the gloomy Hague School canvases so popular in prewar Canadian collecting circles. The Canadian War Memorials Fund was also able to offer unprecedented First World War commissions to three other women artists, although the authorities considered it too dangerous for them to work overseas. Frances Loring (1887–1968) and Florence Wyle (1881–1968) sculpted one pair and thirteen individual figures of munitions and farm labourers at work that were subsequently cast in bronze. Dorothy Stevens (1888–1966) made prints based on her drawings of a Toronto aircraft factory and a munitions factory—for example, Munitions – Heavy Shells, c.1918, which depicts women working in a weapons factory.
Which Data Structure Is Used in Tree? A tree is a hierarchical data structure that consists of nodes connected by edges. Each node in a tree can have zero or more child nodes, except for the root node which has no parent. Trees are widely used in computer science and have various applications such as representing hierarchical relationships, organizing data, and implementing algorithms. The Basic Components of a Tree Before we dive into the data structure used in trees, let’s understand the basic components of a tree: - Node: A node is a fundamental building block of a tree. It contains data and references to its child nodes (if any). - Edge: An edge is a connection between two nodes, representing the relationship between them. - Root: The root is the topmost node in a tree. It serves as the starting point for accessing all other nodes in the tree. - Parent: A parent node is any node that has one or more child nodes. - Child: A child node is directly connected to its parent node. - Sibling: Sibling nodes share the same parent. - Leaf: A leaf node is a node that has no children. Data Structure Used in Trees: Linked List or Array? When it comes to implementing trees, there are two common choices for storing and organizing the nodes: linked list and array. Linked List Implementation In a linked list implementation, each node stores a reference to its child nodes. The child nodes are dynamically allocated and connected using pointers or references. This dynamic nature allows for efficient insertion and deletion of nodes within the tree. However, navigating through the tree can be slower compared to an array implementation, as it requires following pointers from one node to another. In an array implementation, the tree is represented using an array where each index corresponds to a node. The relationships between nodes are determined by their indices in the array. For example, given a node at index i, its left child would be at index 2i, and its right child would be at index 2i + 1. This fixed indexing scheme allows for faster navigation through the tree but can be less flexible when it comes to adding or removing nodes. Choosing the Right Data Structure The choice between linked list and array implementation depends on the specific requirements of your application. If your tree structure needs frequent modifications such as insertions and deletions, a linked list implementation might be more suitable due to its dynamic nature. On the other hand, if your focus is on efficient navigation and access of nodes, an array implementation could provide better performance. It’s important to note that there are other advanced data structures optimized for specific scenarios, such as balanced search trees (e.g., AVL trees or red-black trees) that ensure efficient operations in terms of time complexity. In summary, both linked lists and arrays can be used to implement trees. The choice depends on factors such as requirements for modification operations versus navigation/access efficiency. Understanding these data structures can help you make informed decisions when designing and implementing trees in your applications.
During the Constitutional Convention in 1787, Wilson helped to draft the U.S. Constitution; he then led the fight for ratification in Pennsylvania. In 1790 he engineered the drafting of Pennsylvania’s new constitution and delivered a series of lectures that are landmarks in the evolution of American jurisprudence. He was appointed an associate justice of the U.S. Supreme Court (1789–98), where his most notable decision was that on Chisholm v. Georgia (1793). In the winter of 1796–97 financial ruin brought on by unwise land speculation shattered his health and ended his career. This article was most recently revised and updated by Michael Levy.
Myopia or nearsightedness is a very common vision issue in which you can see objects that are near to you clearly, but objects that are far away appear blurry. It happens when the shape of the eye causes light rays to refract improperly, focusing images in front of your retina rather than on your retina. Nearsightedness may occur slowly or rapidly, usually worsening during childhood and adolescence. Nearsightedness normally has the tendency to run in families. A basic eye exam can check whether you are suffering from nearsightedness. You can compensate for the blur with the help of contact lenses, eyeglasses, or refractive surgery. - Blurry vision when you look at objects that are far away - You need to partially close or squint your eyelids in order to see clearly - Headaches because of eyestrain - You face difficulty in seeing while you drive a vehicle, particularly at night (night myopia) Nearsightedness is usually first identified during childhood and is usually diagnosed between the early school years through the teens. A kid with nearsightedness may: - Consistently squint - Need to sit closer to the movie screen, television, or the front of the classroom - Seem to be unaware of objects that are at a distant - Holding objects close to the face - Excessively blink - Rub his or her eyes often Your eye has actually two parts that focus images- the cornea and the lens. - People suffer from Myopia when the eyeball becomes too long, relative to the focusing power of the cornea and also the lens of the eye. This allows light rays to focus at a point in front of the retina, instead of directly on its surface. - Nearsightedness can even be caused by the lens and/or cornea being way too curved for the length of the eyeball. In certain conditions, myopia happens because of a combination of all these factors. - Myopia usually starts in childhood, and you may have a greater risk if your parents are nearsighted. In maximum conditions, nearsightedness stabilizes in early adulthood but at times it keeps on progressing with age. When to see a doctor? If you face serious difficulty in clearly seeing things that are at a distance and that you can’t perform a task as well as you want to, or if the quality of your vision diminishes your enjoyment of activities, then you must visit an eye doctor. The optometrist can easily understand the level of your nearsightedness and suggest to you the treatment options in order to improve your vision. Even though it may not always be obvious that you’re facing trouble with your vision, the American Academy of Ophthalmology advises you to go for regular eye exams. This is because if you have any issues they can be detected early. Nearsightedness is related to a variety of complications from mild to serious, like: - Reduced quality of life. Untreated nearsightedness can negatively impact your quality of life. You may not be able to do a task as well as you want to. And your restricted vision may be a hindrance to your enjoyment of daily activities. - Eyestrain. Untreated nearsightedness may cause you to strain or squint your eyes in order to maintain focus. This can result in headaches and also eyestrain. - Impaired safety. Your own safety and also that of others may be at risk if you have a vision issue. This could be specifically serious if you are driving a vehicle or operating any heavy appliance. - Financial burden. The expense of corrective lenses, eye examinations, and medical treatments can also add up, particularly with a chronic case like nearsightedness. Vision loss and vision reduction can also affect income potential in certain conditions. - Other eye issues. Serious nearsightedness puts you at great risk of glaucoma, cataracts, retinal detachment, and myopic maculopathy — damage in the central retinal area. The tissues present in long eyeballs are stretched and thinned, resulting in inflammation, tears, new blood vessels that are weak and bleed easily, and scarring. Get the Help you need! You can get in touch with Scottsdale Eyeology if you want to receive the best myopia treatment in Scottsdale, AZ. Our optometrist in Scottsdale will perform a comprehensive eye examination and provide you with quality care for all your vision problems. We are just a call away.
World Hydrogen and Fuel Cell Day (H2FC Day) is annually observed on October 8 to recognise the importance of the chemical element, Hydrogen, and its role in the transition towards a cleaner and more equitable energy future. - The day aimed at promoting awareness and understanding of hydrogen as a clean and sustainable energy source, along with the versatile technology of fuel cells. i.In June 2015, the Senate of the United States of America (USA) designated the 8th October of every year as ‘‘National Hydrogen and Fuel Cell Day’’. - The idea of the observance was initiated by the Fuel Cell and Hydrogen Energy Association (FCHEA), the trade association for the fuel cell and hydrogen energy industry in the USA. ii.The first H2FC Day was observed on 8th October 2015. Why October 8? October 8th written in mm/dd format (10/08) refers to the atomic weight of hydrogen (1.008) therefore 8th October was chosen to observe the Hydrogen and Fuel Cell Day. Types of Hydrogen: i.Hydrogen is classified into several types based on its production methods and the carbon dioxide (CO2) emissions it can generate. ii.Each category has its own advantages and disadvantages compared to the others: Green hydrogen: It is produced by electrolysis of water using electricity generated from Renewable Energy (RE) sources. Blue Hydrogen: It is derived from hydrocarbons like natural gas, but carbon capture is employed to reduce its emissions impact. - While not produced directly from RE sources, it is considered cleaner than grey hydrogen. Grey hydrogen: It comes from fossil fuels. Although it is obtained in a similar way to blue hydrogen, CO2 emissions are not controlled so pollution is higher. i.A fuel Cell is an electrochemical energy conversion device, that utilises Hydrogen and Oxygen to generate electricity, heat, and water. ii.It uses the chemical energy of hydrogen or other fuels to cleanly and efficiently produce electricity. i.It can operate at higher efficiencies than combustion engines and can convert the chemical energy in the fuel directly to electrical energy with efficiencies capable of exceeding 60%. ii.Fuel cells have lower or zero emissions compared to combustion engines. There also are no air pollutants. i.H2FC Day serves as a platform to acknowledge the potential of hydrogen and fuel cells in addressing the pressing challenges of climate change, energy security, and environmental sustainability. ii.Hydrogen and fuel cells can be used in multiple sectors for transportation, stationary power, and so on enabling energy security, resiliency, etc in emerging technologies. iii.Hydrogen is composed to play a substantial role in the global energy mix, potentially representing up to 12% of total energy production by 2050, with a notable reduction in associated costs. World Hydrogen and Fuel Cell Day Celebrations in India: On October 7, 2023, the eve of World H2FC Day, the Government of India (GoI) organised an event in New Delhi, Delhi to explore the potential of hydrogen as a green and sustainable energy. - The event was organised by the Ministry of New & Renewable Energy (MNRE), in association with Solar Energy Corporation of India Limited, and gathered hydrogen experts from the industry, academia, and government. Roadmap for the National Green Hydrogen Mission: During the event, the MNRE unveiled the Research and Development (R&D) Roadmap for the “National Green Hydrogen Mission”, with a budget of Rs. 400 crores. - This aims to guide the development of a robust research and development ecosystem for the commercialisation of green hydrogen and contribute to India’s ambitious climate and energy goals. i.The roadmap emphasizes the development of materials, technologies, and infrastructure to improve the efficiency, reliability, and cost-effectiveness of green hydrogen production, storage, and transportation. ii.The R&D program also prioritizes safety and addresses technical barriers to developing a hydrogen economy. National Single Window System (NSWS): i.The event also marked the launch of the National Single Window System (NSWS) Green Hydrogen page for approvals under the National Green Hydrogen Mission. This will enable industry stakeholders to obtain all approvals related to projects under the Mission. MNRE in association with the Department of Financial Services (DFS), Ministry of Finance organised a roundtable meeting to create synergy between the banking system and green hydrogen developers. - This aims to facilitate access to low-cost finance and thus lower the cost of green hydrogen.
Gould’s Belt is a long chain of clouds in the Milky Way comprised of stellar nurseries and hot young stars. Stretching across a substantial part of the night sky, Gould’s Belt includes the Orion Nebula — the middle object in Orion’s “sword” — and a number of other star-forming regions. These regions are opaque in visible light, so the Spitzer Gould’s Belt Survey project used NASA’s Spitzer Infrared Space Telescope, the European Space Agency’s Herschel Space Observatory, and the James Clerk Maxwell Telescope in Hawaii to map the region in infrared and submillimeter light. The survey was led by scientists at the Center for Astrophysics \| Harvard & Smithsonian, in collaboration with a number of other institutions around the world. Since the completion of observations in 2006, the data has continued to supply astronomers with insights into the formation of new stars in the Milky Way. American astronomer Benjamin Gould identified the belt of bright stars and nebulas that bears his name in 1879, while he was assisting the Argentinian government to establish a national observatory. Gould’s Belt stretches across a large portion of the sky, crossing constellations well-known in the Northern Hemisphere sky, including Orion, as well as several only visible from the Southern Hemisphere, such as the Southern Cross. The Orion Nebula and several other large nebulas in Gould’s Belt are known as molecular clouds, which contain regions where new stars form. Significantly, the belt contains a number of hot blue stars; these live a relatively short amount of time, which necessarily implies they are young. Since its discovery, astronomers determined all the nebulas of Gould’s Belt are genuinely linked together in one strand roughly 3000 light-years long. Since the Milky Way is a spiral galaxy, it’s possible the structure is a small spiral arm or arm fragment. The Spitzer Gould’s Belt Survey was designed to study star formation and young stars in this region, which is a relatively close 325 light-years from the Solar System. The survey, conducted primarily using the Spitzer Infrared Space Telescope with follow-up data from other observatories, used infrared and submillimeter light to peer into clouds that are opaque in optical wavelengths. That allowed astronomers to find both newborn stars and map the structure of the gas in the molecular clouds. The observational portion of the survey is complete, but the data continues to be useful to astronomers studying star formation and galactic structure. The survey was led by astronomer Lori Allen, formerly of CfA and now at the National Optical Astronomy Observatory (NOAO), with collaborators at CfA, NASA, and the European Space Agency, along with a number of universities in the United States and Europe.
What is Electron Emission? The liberation of electrons from the surface of a substance is known as electron emission. For electron emission, metals are employed because they have many free electrons. In a metal like copper, platinum or tungsten, there are plenty of free electrons. At room temperature these electrons are free only to the extent that they may transfer from one atom to another within the metal but they cannot leave the metal surface. A free electron cannot escape from the metal surface because it is pulled back by the positively charged atom. The force exerted at the surface of metal that prevents the free electrons from escaping, is called the surface barrier. The attractive surface forces tend to keep the electrons within the metal surface, except for a small portion that happens to have sufficient kinetic energy to breakthrough the energy barrier caused by these forces. The majority of electrons move too slowly for this to happen. The electrons are required to perform a certain amount of work to overcome the restraining forces in order that they may escape out of the surface of a metal. To do this work the electrons must be imparted with sufficient energy from some external source of energy, since their own kinetic energy is inadequate. The amount of energy required for the escape of electrons varies with different materials i.e., electron emission can take place more easily in some materials than in others. Modern physics tells us that even at the absolute zero temperature, the velocity (or kinetic energy) of all the electrons does not reduce to zero; there are many electrons that possess appreciable energy. The maximum energy that an electron in a metal has, at the absolute zero temperature, is called the Fermi level of energy and is designated as EF. If EB is the total barrier an electron has to overcome for coming out of the metal surface, the additional energy required to be imparted to an electron at absolute zero temperature to enable it to escape out will be equal to EB – EF. This additional energy i.e., EB – EF is called the work function of the metal and is designated as Ew or Φ that is In other words, the work function (Ew or Φ) of a metal may be defined as the difference between the energy required to move an electron of a metal to an infinitely large distance and the maximum energy an electron can have at absolute zero temperature. The work function of a metal depends upon the nature of the metal, and the surface conditions. Thus different metals have different work functions. Metals employed for electron emission should have low work function so that a small amount of energy is required for electron emission. There arc several methods by which electron emission can be brought about. In all these methods the electrons arc supplied with energy in one form or the other in a quantity, from which they obtain kinetic energy sufficient to overcome the surface restraint. Types of Electron Emission - Thermionic Emission - Secondary Emission - Field Emission or Cold Cathode Emission - Photoelectric Emission
The modern era has witnessed rapid change that improved the lives of many but also created new social problems. The 17th to 19th centuries included the Enlightenment, the scientific revolution, and the Industrial Revolution. During this period, great unrest occurred, with social contract theory spawning revolutions in Europe and the Americas. The emergence of capitalism on the ruins of feudalism fueled the rise of a low-paid urban labor force and a ballooning of numerous related social ills, such as poverty and crime. Philosophers around the world and throughout history—including Buddha, Plato, and Confucius—have proposed systems of thought to address the social problems of their age. Three major philosophical movements arose to address the challenges of the modern era. In Europe, the Enlightenment—often dated from 1685 to 1815 and also called the Age of Reason—inspired societies to turn to reason, science, and technology to achieve better lives for individuals and steady progress for the human race. New fields of social science arose, among them sociology, as a means of impartially studying and presenting solutions to social problems. New institutions were developed to implement these solutions, many of which still exist today—among them democratic government, national banks and lending programs, and a wide array of nonprofit organizations to serve those in need. The economic progress of this era relied on the system of capitalism, which many thinkers in the early 19th century blamed for producing the bulk of human suffering they witnessed. These thinkers increasingly embraced a type of socialism called Marxism, which advocated for a communist revolution that placed the working class in control of the government and economy. Marxist ideology predicted that communist revolutions would inevitably take place as capitalism advanced within the industrializing world and that these revolutions would create a society devoid of major social problems. Neither of these predictions were realized. Instead, Russia, China, and many countries in Africa, Asia, and South America underwent communist and socialist revolutions but failed to achieve the economic or political equality that Marx had envisioned. Marxist theorists began rejecting both the inevitability of revolution and the Enlightenment belief that the pursuit of knowledge would lead to progress. Instead, they viewed knowledge as reflective of systems of power. They argued that philosophers must take on a new role. Rather than be impartial observers, philosophers must change the way people engage in public discourse in order to cast light on oppression and ultimately accomplish Marx’s goal of an equal society. This branch of philosophy became known as critical theory. Currently, politicians, school board members, teachers, and parents—among others—are active in debates about the inclusion of critical race theory in educational curriculums. This chapter examines the philosophies of Enlightenment social theory, Marxist theory, and critical theory that inform so much of the way we live our lives today.
While Earth’s climate has changed throughout its history, warming is now happening at a rate not seen in the past 10,000 years. Scientific information taken from natural sources (such as ice cores, rocks, and tree rings) and from modern equipment (like satellites and instruments) all show the signs of a changing climate. Source: NASA The UN Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change. The governments of all of 193 UN member countries accept its findings. The IPCC states: ‘Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact’. The burning of fossil fuels like coal, oil and gas has increased carbon dioxide (CO2) in Earth’s atmosphere. Our industrial activities have raised atmospheric CO2 levels by nearly 50% since 1750. We know this increase is due to human activities, because scientists can identify a distinctive isotopic fingerprint in the atmosphere. Clearing land for agriculture, industry, and other human activities has contributed to increased levels of greenhouse gas. In its March 2023 Report, the UN Intergovernmental Panel on Climate Change concluded thatit is unequivocal that the increase of CO2, methane, and nitrous oxide in the atmosphere is the result of human activities, and that human influence is the principal driver of many changes observed across the atmosphere, ocean, cryosphere and biosphere. While the Sun has played a role in past climate changes, the evidence shows the current warming cannot be explained by the Sun. Source: NASA Climate change has already started. We are seeing its effects in the UK in the form of heatwaves, droughts, devastating storms, floods, and damage to harvests. Globally the effects of climate change will increase migration, conflict, disease and global instability. Some of the effects of climate change are happening much faster than climate scientists expected. Human-made climate change is the biggest crisis of our time. It threatens the future of the planet that we depend on for our survival. In April 2023 the UN’s Intergovernmental Panel on Climate Change (IPCC) warned that we only have until 2030 to reduce CO2 emissions and limit global warming to a maximum of 1.5C. Warming above 1.5% is likely to result in climate breakdown. The good news is that climate change can be stopped. We need to act fast. The UN Intergovernmental Panel on Climate Change (IPCC) warned this year that we have seven years left to reduce CO2 emissions and limit global warming. But it added that we have options in all sectors – including energy, industry, transport and agriculture – to at least halve emissions by 2030. The IPCC said: ’We are at a crossroads. The decisions we make now can secure a liveable future. We have the tools and know-how required to limit warming. I am encouraged by climate action being taken in many countries. There are policies, regulations and market instruments that are proving effective. If these are scaled up and applied more widely and equitably, they can support deep emissions reductions and stimulate innovation’. The IPCC says: Limiting global warming will require big changes in energy, industry, transport and agriculture. We need a substantial reduction in fossil fuel use, widespread electrification, improved energy efficiency, and use of alternative fuels such as hydrogen. Since 2010, the costs of solar and wind energy, and batteries have decreased by up to 85%. An increasing range of policies and laws have enhanced energy efficiency, reduced rates of deforestation and accelerated the deployment of renewable energy. Reducing emissions in industry will involve using materials more efficiently, reusing and recycling products and minimising waste. Industry accounts for about a quarter of global emissions. Achieving net zero will be challenging and will require new production processes, low/zero emissions electricity, hydrogen, and, where necessary, carbon capture and storage. Agriculture, forestry, and other land use can provide large-scale emissions reductions and also remove and store carbon dioxide at scale. However, land cannot compensate for delayed emissions reductions in other sectors. Changes in land use practices can benefit biodiversity, help us adapt to climate change, and secure livelihoods, food and water, and wood supplies. China is currently the largest greenhouse gas emitter in the world, but it is decarbonising much faster than countries like the US. China generates almost half of the world’s installed offshore wind, with 26 gigawatts of a total of 54 gigawatts worldwide in 2021. Last year China had an estimated 2.7 million people employed in the solar energy sector, making up more than half of the world’s 4.3 million solar jobs. Source: Harvard. The UK is among those countries with very high historical emissions. We have made a much bigger contribution to the climate crisis than other countries with large populations, such as China and India. Our current UK carbon emissions figure doesn’t include ‘hidden’ carbon – the fossil fuels used to make all the goods we now import from overseas. [Source: Gdn, bookmarked]. And our appetite for beef, soy, palm oil, rubber, cocoa, coffee and wood pulp is destroying vast areas of forest across South America, South East Asia, and Africa, adding a further 40% to our real carbon emissions. ‘Global warming’ refers to the long-term warming of the planet, and is only one aspect of climate change. Global temperature shows a well-documented rise since the early 20th century and most notably since the late 1970s. The Climate Stripes graphic on this page shows this rise. 2023 is already set to have the hottest global average land and sea temperatures ever recorded. ‘Climate change’ includes global warming and the broader range of changes that are happening to our planet. These include rising sea levels; shrinking mountain glaciers; higher ocean temperatures; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times. Source: NASA The countries most affected by climate change (small island nations, and much of Africa and Asia) are often the least responsible for it. Many countries in the global south are now experiencing floods, desertification, increased water scarcity, and devastating tornadoes and hurricanes. These are also the countries with the fewest resources to deal with climate change, making them vulnerable to political unrest, armed conflict, and mass migration. [Source: Global Justice Now] An Oxfam study found that the richest one percent of the world’s population were responsible for more than twice as much carbon pollution as the world’s poorest 3.1 billion people, from 1990 to 2015. The truth is that, European and North American countries currently consume more, and have higher emissions per person on average, than those in China or India. However, this does mean that we can do more than most countries with equivalent emissions to tackle climate change – and use our wealth and diplomatic power to lead by example. [Source: Greenpeace] A lot of people believe that renewable energy is expensive, but this simply isn’t true! Solar power and onshore wind are the cheapest ways of generating electricity. The energy they produce is cheaper than using nuclear, gas, oil, or coal. The cost of renewables has fallen faster than anyone could have predicted. Industry is developing new techniques for storing electricity and managing demand at peak times, meaning that even if it’s not sunny or windy, we can still rely on renewable energy sources. Source: WWF.
For women in the United States, the rights of today were achieved by courageous women with a cause and a drive to see change. These women came, and continue to come, in all shapes and colors. Elizabeth Cady Stanton and Susan B. Anthony were among the first to begin the United States women’s movement; Rosa Parks was an essential part to the Montgomery bus boycott during the civil rights movement; Sandra Day O’Connor was the first woman nominated and confirmed to the U.S. Supreme Court; Hillary Clinton was a strong candidate for the Democratic Party nomination for President in 2008 and is now Secretary of State under the Obama administration; and lastly, Sonia Sotomayor is the first Hispanic man or woman to be confirmed as a U.S. Supreme Court justice. These women know what passion is and how to achieve equality. African women, arguably, have the same drive and determination for change; however, in an overly patriarchal culture, outspoken women fear reprisal, degradation, or worse. The Liberian case study is worth all attention. Women who were directly affected by the civil war related injustices used the Truth and Reconciliation Commission (TRC) as their platform to demand, among other things, quality, justice, and freedom of speech. The Republic of Liberia is located on the Western coast of Africa bordered by Sierra Leone, Guinea, Cote d’Ivoire and the Atlantic Ocean. Historically, the inhabitants of Liberia were former U.S. slaves who dominated the indigenous population through political and economic repression. The Americo-Liberian government was politically dominate until April 1980 when Samuel Doe led a coup to overthrow then president, William Tolbert, and ascended to president. Even though the indigenous population despised repression, Doe’s assumption to presidency came with an era of oppression, dictatorship, and human rights abuses. The political instability continued as Charles Taylor, Doe’s long time Procurement Chief, led an insurgent group to overthrow and kill him. In an attempt to achieve peace and stability, Liberia passed 13 peace agreements followed by temporary ceasefires, but civil violence and in-fighting continued until 2003. Finally, the Comprehensive Peace Agreement (CPA) was agreed to in Accra, Ghana, which discontinued the civil war and created a transitional and fluid national government for two years. The 2005 Liberian election presented the country with its first female president, Ellen Johnson-Sirleaf, in conjunction with the establishment of Liberia’s Truth and Reconciliation Commission (TRC) which was mandated to seek national unity, reconciliation, and justice. From the advent of the TRC, women decisively became involved in making sure the TRC included gender related issues. They knew that despite the fact women are the majority of human rights abuse victims in armed conflicts in Africa, women have been excluded from participating in peace negotiations and decision making on the way forward to secure and create a safe and prosperous environment where they can raise their children. Liberian women’s organizations made it clear that there could not be any real truth telling and real reconciliation if women were excluded from the TRC. As a result, the TRC collected written records of first-hand accounts retold by women. On July 31, 2008 the TRC trained 42 women, from all political sub-divisions, to sensitize and encourage more women to testify at the TRC. As women were being trained, there were simultaneous workshops for men, whose female loved ones would be testifying, equipping them with tools to give proper support to the women. These dialogues were a major part to the project entitled, “Evaluating and Re-Enforcing Women’s Participation In Transitional Justice and Governance” in October 2008. More dialogues were planned throughout the year and once completed the women in these communities came together to mobilize and encourage other women to participate in creating and consolidating peace in Liberia. As the climax of the project neared, the National Conference for Women adopted recommendations about human rights violations and forwarded them to the TRC to be included within the final report. They recommended that: - the warlords and defunct warring factions be sentenced to jail or hard labor, - a war crimes tribunal for Liberia be created, - warlords and people with criminal records be barred from public office, and - child soldiers be given immunity from crimes committed. The ability for women to learn and teach other women, with the support from women’s organizations, has laid a strong, successful foundation for women in Liberia. During the dialogues in 2008 Liberian women strongly supported access to participation in all levels of government, pushed for recognition of knowledge gaps, and proposed more access to education for women. The persistence of Liberian women justifies the increased participation of women in the Truth and Reconciliation Commission. TRC Chairman Counselor Jerome Verdier praised them for their immense contribution to the Liberian peace process saying that “‘because of their roles, peace has now been restored to the country.’” Because of women’s determination, and the recognition of their contribution at all levels of society, Liberia has made forward progress in leaving the problem of gender inequality at a distance. By: Josh Perry
Definite Demonstrative Nouns in Arabic Posted by Fisal on Mar 23, 2011 in Arabic Language, Culture, Grammar, Vocabulary A new type of Arabic definite nouns to look at is the Demonstrative Nouns. These Nouns are definite by themselves because they Refer to a definite person, thing or place. They are referring words. In English, these are called Demonstrative Adjectives or Adverbs of Place but in Arabic, they are Nouns. Arabic has three numbers: singular, dual and plural. Arabic nouns are also masculine or feminine. So, we have different demonstrative nouns that represent or refer to all these three numbers and genders. (1) هذا = ذا = (he-This) : It refers to near masculine singular nouns; (persons and things) Examples: – This is a poet.= هذا شاعر – This is a book. = هذا كتاب (2) ذلك =ذاك = (That) : It refers to faraway masculine singular nouns; (things only). Examples : – That is the Book no doubt in it. =ذلك الكتاب لا ريب فيه – Like father like son. (proverb) = هذا الشبل من ذاك الأسد (3) هذه= ذه = ذى = هذى = (she-This) : It refers to near feminine singular nouns; (persons and things). Examples: – This is a girl. = هذه بنت – This is a tree. = هذه شجرة – These are trees. = هذه أشجار – These are schools. =هذه مدارس (Note: هذه is also more common with plural non-human nouns instead of هؤلاء .) (4) تلك = (That/Those) : It refers to faraway feminine singular or plural nouns; (persons or things). Examples: – That is a girl. = تلك فتاة – That is a tree. = تلك شجرة – Those are trees. = تلك أشجار (5) هذان = ذان = (These two = Both) : It refers to near dual masculine nouns. Examples: – These are two boys. = هذان ولدان. – These are two books. = هذان كتابان. (6) هاتان = تان (These two = Both) : It refers to near dual feminine nouns. Examples: – These are two girls. = هاتان بنتان – These are two papers. = هاتان صحيفتان (Note: When you apply the dual suffix ( ان /ين ) to a noun ending in the closed (marboota) Ta’a, this Ta’a changes to an open Ta’a to allow more letters to be added to the word.) (7) هؤلاء = أولاء = أولى = أولئك = (These / Those) : It refers to near plural masculine or feminine nouns; (persons or things). Examples: – These are heroes. = هؤلاء / أولئك أبطال – Those are girls. = هؤلاء فتيات (8) هنا = (Here) : It refers to near places. Examples: – Here is the school. = هنا المدرسة – Here are the schools. = هنا المدارس – The hotel is here. = هنا الفندق (9) هناك = هنالك = (There) : It refers to faraway places. Examples: – There is a school next to the bank. = هناك مدرسة بجوار البنك – There are schools. = هناك مدارس – There is a hotel. = هنالك فندق – There are hotels. = هنالك فنادق Are you ready for learning Pronouns? Do you know that they are Definite Nouns in Arabic? OK, Next time..!! Check us back soon Peace سلام /Salam/ Build vocabulary, practice pronunciation, and more with Transparent Language Online. Available anytime, anywhere, on any device.
Slug and snail slime not only acts as an adhesive and lubricant for the creatures, it allows them to glide over rough surfaces without the risk of injury. New reseach shows that the mucus could be used in potentical medical applications. Due the slime’s antibacterial and antiviral properties, slug and snail mucus has been investigated for future applications in medicine, in particular, for fighting multidrug resistant bacteria such as MRSA. By Julie Colthorpe Over the last few years, several studies have been carried out on snail and slug mucus’ antimicrobial activity against other microorganisms, especially against multidrug resistant bacteria, such as MRSA (methicillin-resistant Staphylococcus aureus). This is particularly important since one of the major public health problems is an increasing number of antibiotic resistant bacteria. For this reason, research in recent years has been directed towards the discovery of new antimicrobial substances, particularly natural substances such as plant extracts, essential oils and antimicrobial peptides isolated from many different animals, including deep-sea creatures and insects. Sticky and slimy but potentially healing Snail and slug mucus is a sticky elastic substance secreted by specific glands with adhesive and lubricants properties that allows the animals to firmly adhere themselves to many different surfaces, including rough terrain. It also helps the creatures from drying out and thanks to their sliminess, they are viewed as fairly unattractive food options for predators. Unlike snails, slugs have no shell to protect them when they detect danger, which is why slugs have a very thick slime, which makes them disgusting to predators, and so are less likely to be eaten. The mucus is also thought to help prevent infection and facilitate healing. Employment in traditional medicine Used since ancient times for human health, snail and slug mucus is still very important in traditional and folkloristic medicine. Moreover, recent research has investigated the protein and components in the mucus and its antibacterial, antiviral and antifungal activity. The research shows that the antimicrobial activities of slug and snail mucus could lead to their potential employment in several fields as natural additives. Wound-healing and antibacterial In a review recently published in the Journal of Complementary and Integrative Medicine, the authors summarize the results of antimicrobial studies of snail and slug mucus and its compounds in order to better understand its application and propose the slime’s employment in future studies as a natural antimicrobial agent. Research shows snail mucus has the ability to facilitate wound healing and to prevent its infections thanks to its many bioactive compounds. Over the few last years, numerous studies on mucus composition have clarified many aspects of its properties, although much remains to be investigated on its antibacterial activity. Antimicrobial activity against superbugs Based on the results obtained by several studies on the antimicrobial properties of snail and slug mucus, it seems clear that this natural product could be a potential subject of further investigations. The new findings regarding its active components are a starting point for the formulation of new products for therapeutic and pharmacological uses as an alternative to conventional antibiotics. Natural peptides, as like those extracted from the snail and slug mucus, could be considered as potential alternatives in therapy. Read the original article here
1. Engage students in a preliminary discussion about where water comes from. Ask students where they get their water at home. Answers will probably include faucets and hoses. Then, ask students where they think that water originally comes from and how it arrived at their homes. Have a few students call out answers, and then follow up on those answers with the questions below. Ask: Does anyone get water straight from a lake or river? Why or why not? What are some potential issues with getting water straight from an open body of water? Answers should include health concerns, convenience, etc. Prompt students with questions about what sorts of things are found in open bodies of water (runoff, animals, chemicals, bacteria, etc.) 2. Explain that many things must happen to some water before it is safe for people to use. Explain that most water must go through a process that makes it potable, or safe for drinking. This process is called the water-treatment process. Tell students that they are going to learn all of the steps in the water-treatment process, and then they will need to analyze them in order to figure out which order the steps are in. 3. Introduce the steps in the water-treatment process. Write each of the steps on the board. Write them in a jumbled list. For example: filtration, disinfection, sedimentation, and coagulation. The correct order is: coagulation, sedimentation, filtration, and disinfection. Make sure to leave room in between each term to write the students’ guesses and the actual definition under each step. 4. Brainstorm meanings of water-treatment process terminology. Ask students what they think each term means and write down their definitions under the terms on the board. Encourage guesses and creativity. To prompt guesses, break the words down and ask what they think each part of the word means (i.e. highlight the following: coagulation, sedimentation, filtration, and disinfection). When you have discussed all the terms, ask for student volunteers who want to help reveal the actual definitions. Pass a copy of the Definitions of Steps in the Water-Treatment Process handout to the student volunteers. Have the volunteers read the definitions aloud. Write the definitions on the board while the volunteers are reading them aloud. Make sure that students understand the vocabulary used in these descriptions. Encourage students to making drawings of each of the steps in the process. 5. Determine the steps in the water-treatment process. Write each of the steps on a piece of paper using large print. Select four new volunteers from the class. Have them come to the front of the room and hand each of them one of the four steps. Have them line up and introduce themselves to the rest of the class as their respective step in the water-treatment process, asking them to describe what happens in that step in their own words. The steps should not be in the correct order when you hand them out to the volunteers at the front of the room. Have the class direct the volunteers where to stand so that they are in the proper order of steps in the water-treatment process. Ask students to make recommendations. If a student needs help, refer him or her to the definitions on the board. Make sure to ask why a student makes a particular suggestion—don’t let students shout out suggestions without support for their ideas. Once students are in the correct order, stop the discussion. Ask five student volunteers to recap what they have learned so far. Have four of the student volunteers cover one step each and say, in their own words, what happens during that step of the water-treatment process. Have the remaining volunteer describe the order of the steps. 6. Explore different orders and brainstorm why these orders wouldn’t work. Ask the four student volunteers to organize into the following order: coagulation, disinfection, sedimentation, and filtration. Ask all students whether the order above would work to make water potable. Then, as a class, discuss why the steps have to go in a certain order. 7. Conclude the activity by explaining the final step in the water-treatment process. Finally, bring the activity full circle by explaining the final step of the water-treatment process. Explain that the EPA (Environmental Protection Agency) adds storage at the end of the water treatment process. Water is placed in a closed tank or reservoir in order for additional disinfection to take place. The water then flows through pipes to homes and businesses in the community. Throughout the activity, assess student engagement based on amount and quality of participation. When students are determining the order of the water-treatment steps, assess answers based on students’ inclusion of evidence, or why they made that particular suggestion. Extending the Learning Encourage students to think about how water is, or is not, treated in other places around the world. If students are studying a particular region, culture, or society as part of a social studies or history class, have students ask their social studies or history teachers the questions below and write a paragraph with the information they’ve gathered. Then, engage students in a 10-15 minute discussion about their findings. Ask: What bodies of water exist near the area of the world? How do people in this location or society bring water to their homes? Do they treat this water to make it safe for drinking? If not, why not? Does everyone in this society or area of the world have access to this treatment process? Why or why not? Subjects & Disciplines - Earth Science - English Language Arts - Explore the process through which water is treated to become potable - Identify the steps in the water-treatment process - Discuss why it is important that the steps in the water-treatment process occur in a certain order - Information organization Science and Engineering Practices - Asking questions (for science) and defining problems (for engineering) Connections to National Standards, Principles, and Practices National Geography Standards - Standard 14: How human actions modify the physical environment - Standard 15: How physical systems affect human systems National Science Education Standards - (5-8) Standard F-2: Populations, resources, and environments What You’ll Need Materials You Provide - Whiteboard, chalkboard, or chart paper The resources are also available at the top of the page. - Large-group learning Before people can safely use water, it must be found, treated, and transported to households. Water that is safe for drinking is called potable water. The treatment piece of this process is called the water-treatment process. The water-treatment process involves four steps, in this order: coagulation, sedimentation, filtration, and disinfection. The purpose of coagulation is to create dirt clumps that are heavy enough to sink, which is important for the next step in the process. Alum and other chemicals are added to the water, forming “floc”—tiny, sticky particles. Dirt in the water sticks to these particles, forming clumps. As water travels through a tank, gravity causes the clumps of dirt to fall to the bottom. The dirt is removed from the water because the water continues to flow, while the dirt remains at the bottom of the tank. The removal of the dirt is called sedimentation. Filtration is the process of passing a liquid or gas through a porous article or mass (paper, membrane, sand, etc.) to separate out a solution (when some matter is dissolved in something else). Disinfection is the use of chemical and/or other means like UV radiation to kill potentially harmful microorganisms and pathogens in the water. Storage is the final step of the water-treatment process. The EPA adds storage at the end of the water treatment process. Water is placed in a closed tank or reservoir in order for additional disinfection to take place. The water then flows through pipes to homes and businesses in the community. This resource was developed for Geography Awareness Week 2010. Each third week of November, students, families, and community members focus on the importance of geography through events, lessons, games, and challenges; and often meet with policymakers and business leaders. Visit the Geography Awareness Week website to find out more about this program. Recommended Prior Activities process of changing from a liquid to a thickened or semi-solid mass. to clean and remove harmful microorganisms. process of separating solid material from liquids or gases. suitable for drinking. process of accumulating small solid deposits. water that has been used for washing, flushing, or industry. facility that purifies water for drinking, hygiene, and other uses.
Read more about The brown recluse spider is a type of recluse spider with a range that is limited to the Midwestern and South Central United States. The species has necrotic venom and its bite, like other brown spiders, requires immediate medical attention. The brown recluse is one of three species of spiders in North America with medically significant venom, the others being the Chilean recluse and the black widow. Although usually light or medium brown, the color of the brown recluse spider can also be whitish, dark brown, or blackish gray. The brown recluse spider is found throughout the Midwestern and South Central United States. Other species of brown spiders also inhabit these regions, but the brown recluse is the most common. They are rarely seen outside of their native habitat and are less common than previously believed. Occasionally, a small number of individuals may be transported to non-native areas, but infestations rarely become established. The brown recluse is distinguished from other brown spiders by the dark violin-shaped mark on its abdomen. It is critical to learn and understand the physical appearance of the brown recluse since many people mistake other spiders for the deadly species. Habitat And Behavior In its natural environment, the brown recluse spider prefers living outdoors under rocks, woodpiles, debris, and logs. It has also adapted to living indoors alongside humans. The spider is resilient enough to withstand extreme temperatures during summer and winter and can survive for long periods without food or water. The brown recluse is nocturnal and actively hunts at night, preying on both living and dead insects. The species does not use webs or suspend from walls and ceilings to capture food but instead crawls into tight spaces in search of prey. During the day, the spider retreats to dark, secluded areas away from predators and human disturbance. As solitary a spider, the brown recluse retreats to the same spot until it is invaded or destroyed. Female spiders remain close to their retreat, while males and older juveniles are more mobile, and will travel farther in search of food and territory. As a result, they are more likely to wander into bedding, clothing, and shoes and are likely to bite when trapped. On rare occasions, they may be observed during the day crawling on walls and exposed surfaces. Such behavior is typically triggered by intolerable conditions such as overcrowding, hunger, and pesticide application. Female recluse spiders lay an egg sac that usually contains between 40 and 50 eggs. Tiny spiders hatch and molt 5 to 8 times before reaching adulthood. They reach maturity after 12 months and have a lifespan of between two and four years. Female brown recluse spiders can produce 4 to 5 egg sacs in a lifetime and can live in the same habitat throughout its lifespan. Infestation levels range from a few spiders to several thousand. Treating the bite of the brown recluse spider involves first aid and immediate medical care. If possible, the spider should be captured and transferred with the patient for identification. Treatment includes immobilizing the affected limb, local wound care, and a tetanus injection. Several therapies have been used with varying degrees of success. Most people living in infested areas have learned to treat the bites without visiting the hospital. Do you know what is the largest spider in the world? Click here for an answer. Also, learn about the deadliest spiders in the world in this article. Your MLA Citation Your APA Citation Your Chicago Citation Your Harvard CitationRemember to italicize the title of this article in your Harvard citation.
Mars is a dusty, cold, desert world with a very thin atmosphere. It has seasons, polar ice caps and weather and canyons and extinct volacanoes, evidence of an even more active past. It's the only planet where we've sent rovers to roam the alien landscape. NASA currently has three spacecraft in orbit, one rover on the surface and another rover under construction here on Earth. India and ESA also have spacecraft in orbit above the Mars. Mars is a rocky planet. Its solid surface has been altered by volcanoes, impacts, winds, crustal movement and chemical reactions. Mars has a thin atmosphere made up mostly of carbon dioxide (CO2), argon (Ar), nitrogen (N2), and a small amount of oxygen and water vapor. Mars has two moons named Phobos and Deimos. Mars is known as the Red Planet because iron minerals in the Martian soil oxidize, or rust, causing the soil and atmosphere to look red.
AES is a mode of operation, and confusion/diffusion are what we use to achieve a certain mode. AES is a block cipher, which replaces one fixed-length block of bits (plaintext) with another fixed-length block of bits (ciphertext) according to the key. A block cipher is not a mode of operation. Confusion and diffusion are a description of how AES behaves to ensure that given a/many plaintext-ciphertext pairs, you cannot recover the key, as well as given a ciphertext, you cannot recover the plaintext. "Confusion" basically means that the equations that represent the ciphertext are too complicated and cannot be worked with, while diffusion means that each bit of the plaintext influences many (half) of the bits of the ciphertext. These two properties help to ensure that extracting the key from plaintext-ciphertext pairs is difficult or infeasible. Since AES only operates on blocks of 128-bits, you require a mode of operation to encrypt plaintexts of size > 128 bits. So a mode of operation is a way of using a block cipher to encrypt (effectively) arbitrary length messages. Since for a fixed key AES is deterministic, a mode of operation also provides a means to randomize plaintext-ciphertext pairs, so that multiple encryptions of a plaintext cannot be distinguished from each other. This is necessary to properly provide confidentiality of the plaintext.
Difference Between Totipotent and Pluripotent Totipotent vs Pluripotent Stem cells are innate cells found in every living organism particularly multicellular organisms. These organisms must be able to undergo different sexual and reproductive stages such as mitosis for the cell’s dividing purposes. These cells must be able to reproduce themselves into more stem cells. Two broad types of stem cells exist. These are the embryonic stem cell and adult stem cell. With the advent of technology, stem cells can now be grown artificially inside laboratories. The research of stem cells was spearheaded by Ernest McCulloch and James Till during the 1960’s at the University of Toronto. For a stem cell to be called a stem cell, it must possess two properties called self-renewal and potency. “Self-renewal” involves the ability of the cell to undergo different cycles of cell division while “potency” is defined as varying types of specialized cells. Two of the words that will be tackled in this article under the cell potency category are totipotent and pluripotent. “Totipotent” is also known as “omnipotent.” In this type, stem cells can vary into two types of stem cells. These are the embryonic and extraembryonic cell types. These cells came from the unification of an egg and a sperm cell. Thus, these cells can become an organism. “Pluripotent” from the Latin word “pluris” means “more” or “many.” These type of stem cells are defined as having the ability and potential to vary and differentiate into three layers. These are the endoderm, mesoderm, and ectoderm. Pluripotent cells may result in an adult cell or fetal cell type. An example of totipotent cells is a zygote which came from the unification of the egg and sperm cell and has undergone several sexual cellular divisions. An example of a pluripotent cell is an embryonic cell which has not yet developed into any other type of cell. 1.Pluripotency and totipotency is under “cellular potency” which is the ability of one cell to differentiate. 2.Pluripotent cells can potentiate into many cells while totipotent cells come from the outcome of two cells that united and have undergone mitotic division. 3.A zygote is an example of totipotent cells while an embryonic cell is an example of a pluripotent cell. 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
Key Instant Recall Facts (KIRFs) are the core facts that children need to be able to recall quickly in order to support their work across the numeracy curriculum. Each year group will have a new focus for each half term. Although each fact will be introduced and practised in some lesson starters, we would ask that you support your child by practising with them at home. The new target will be sent out each half term, with a top tips sheet to help you and your child. Please speak to your child's class teacher if you would like any further information or support.
Millions of people around the world suffer from severe spinal cord injuries that result in permanent loss of control of their arms or legs, or loss of bladder, bowel or sexual functions. Now, US researchers have developed an oral medication that offers hope that some of these lost functions could be regained. When given to laboratory mice shortly after a spinal cord injury, the drug restored the animals’ mobility. The experimental drug, called LM11A-31, works by blocking the release of a protein that after spinal cord injuries destroys oligodendrocytes, which are nerve cells that surround and protect axons. Axons are the long, thread-like nerve-cell projections that help transmit motor impulses between the brain and the rest of the body. In experiments with mice with crippling spinal cord injuries similar to those seen in humans, the drug overcame a major hurdle in conventional therapies. The compound easily crossed the blood-brain barrier – the natural partition that protects the brain from potentially harmful foreign substances in the bloodstream – and prevented the normal post-injury die-off of oligodendrocytes.
Scientists have long suspected that ocean acidification is affecting corals' ability to build their skeletons, but it has been challenging to isolate its effect from that of simultaneous warming ocean temperatures, which also influence coral growth. New research from the Woods Hole Oceanographic Institution (WHOI) reveals the distinct impact that ocean acidification is having on coral growth on some of the world's iconic reefs. In a paper published Aug. 27, 2020, in the journal Geophysical Research Letters, researchers show a significant reduction in the density of coral skeleton along much of the Great Barrier Reef--the world's largest coral reef system--and also on two reefs in the South China Sea, which they attribute largely to the increasing acidity of the waters surrounding these reefs since 1950. There is currently some speculation that exhaust gas cleaning systems (scrubbers) used in the shipping industry as a compliance tool for new air pollution regulations may be contributing to acidification in some key areas. Several national and regional authorities have already acted to ban or restrict their use to prevent acidification, although this research does not look at the explicit impact of these devices. There is also concern that runoff from the agricultural industry and other pollutants are accelerating acidification. "This is the first unambiguous detection and attribution of ocean acidification's impact on coral growth," says lead author and WHOI scientist Weifu Guo. "Our study presents strong evidence that 20th century ocean acidification, exacerbated by reef biogeochemical processes, had measurable effects on the growth of a keystone reef-building coral species across the Great Barrier Reef and in the South China Sea. These effects will likely accelerate as ocean acidification progresses over the next several decades." Roughly a third of global carbon dioxide emissions are absorbed by the ocean, causing an average 0.1 unit decline in seawater pH since the pre-industrial era. This phenomenon, known as ocean acidification, has led to a 20 percent decrease in the concentration of carbonate ions in seawater. Animals that rely on calcium carbonate to create their skeletons, such as corals, are at risk as ocean pH continues to decline. Ocean acidification targets the density of the skeleton, silently whittling away at the coral's strength, much like osteoporosis weakens bones in humans. "The corals aren't able to tell us what they're feeling, but we can see it in their skeletons," said Anne Cohen, a WHOI scientist and co-author of the study. "The problem is that corals really need the strength they get from their density, because that's what keeps reefs from breaking apart. The compounding effects of temperature, local stressors, and now ocean acidification will be devastating for many reefs." In their investigation, Guo and his co-authors examined published data collected from the skeletons of Porites corals--a long-living, dome-shaped species found across the Indo-Pacific-- combined with new three-dimensional CT scan images of Porites from reefs in the central Pacific Ocean. Using these skeletal archives, which date back to 1871, 1901, and 1978, respectively, the researchers established the corals' annual growth and density. They plugged this information, as well as historical temperature and seawater chemistry data from each reef, into a model to predict the corals' response to constant and changing environmental conditions. The authors found that ocean acidification caused a significant decline in Porites skeletal density in the Great Barrier Reef (13 percent) and the South China Sea (7 percent), starting around 1950. Conversely, they found no impact of ocean acidification on the same types of corals in the Phoenix Islands and central Pacific, where the protected reefs are not as impacted by pollution, overfishing, runoff from land. While carbon dioxide emissions are the largest driver of ocean acidification on a global scale, the authors point out that sewage and runoff from land can exacerbate the effect, causing even further reductions of seawater pH on nearby reefs. The authors attribute the declining skeletal density of corals on the Great Barrier Reef and South China Sea to the combined effects of ocean acidification and runoff. Conversely, reefs in marine protected areas of the central Pacific have so far been shielded from these impacts. "This method really opens a new way to determine the impact of ocean acidification on reefs around the world," said Guo. "Then we can focus on the reef systems where we can potentially mitigate the local impacts and protect the reef."BLOG COMMENTS POWERED BY DISQUS
Schizophrenia is a chronic mental disorder that affects how a person thinks, feels, or behaves. When it is active it causes hallucinations, delusions, trouble with thinking, and lack of self-motivation. It affects 1 of every 100 people and usually starts during early adulthood. Usually, men show symptoms earlier than women. - Positive symptoms – Disorganised speech – Movement disorder - Negative symptoms – Lack emotion – Reduced feeling of pleasure in everyday life – Lack of motivation – Negligence of basic personal hygiene - Cognitive Symptoms – Poor ability to absorb and interpret information – Inability to sustain attention – Problems with working memory There is no particular cause of schizophrenia. It is thought to be caused by a combination of genetics or environmental factors. If you have a family history of schizophrenia you are probably more likely to have it. The genes which are involved in it are still unknown but it’s probably multiple genes. Environment too plays a major role. Prenatal, perinatal and the period of pregnancy is a sensitive period of brain development. So complications occurring during this time such as maternal malnutrition, exposure to toxic n viruses, maternal bleeding during pregnancy, low birth weight are associated with schizophrenia later on in life. Other factors such as traumatic or stressful life circumstances, child abuse, hardships also increase the risk. Taking mind altering drugs particular marijuana during adolescence and early adulthood has been linked to early onset and risk of schizophrenia. Again, just because these things occurred, does not mean that schizophrenia will occur. It’s a very small minority of people who experience those risk factor that will develop schizophrenia, but it does increase risk. Treatment and self-help Seek treatment earlier for best possible outcome. While there is no cure for schizophrenia, people can recover from symptoms with the help of an antipsychotic medication which reduces symptoms such as hallucinations, delusions, paranoia and disordered thinking. What you can do to manage your stress - Take proper sleep - Manage stress - Reach out to others for support - Get active, do yoga or exercise - Take care of yourself - Avoid drugs and alcohol - Eat a healthy, balanced diet Left untreated schizophrenia can result in severe problems such as self-injury, suicide attempts, obsessive compulsive disorder, depression, aggressive behavior and much more. So self-help with medication is a must; because a medication is not the cure for schizophrenia it can only treat the symptoms. There are many misconceptions about schizophrenia, even some people use stereotypes when talking about this mental disorder. Usually, people think it’s like having a personality disorder in which a person have multiple personalities or people having schizophrenia are dangerous or violent because of their symptoms which are not true. Just because someone is suffering from a mental disorder does not mean that they are harmful or violent. Sufferers often describe it as sounds of voices inside their brain which sometimes cause loss of concentration, irritation and many other symptoms depending from person to person. People who are suffering often isolate themselves all they need is your love and support. They just want you to understand them and help them not just avoid or get afraid of them.
Definition - What does Learning Style mean? A person's learning style refers to the way in which they best receive and process information. While an individual may learn through many different methods, most people will favor some methods over others. A person will usually show a preference for information presented in their favored learning style. For instance, some individuals prefer to learn using hands-on activities while others tend to learn better through listening to lectures. Since the concept of learning styles was first developed, several competing theories have arisen. Nonetheless, evaluating students' learning styles continues to be one tool used to develop teaching methods and curricula to improve educational outcomes. WorkplaceTesting explains Learning Style Researchers have conducted several different studies meant to identify various learning styles for both children and adults. Results differ as to the number of learning styles that exist across populations. One commonly accepted set of learning styles is the VARK modalities. VARK is an acronym for visual, aural/auditory, read/write and kinesthetic. Applying this system, a person who learns best by taking notes would be considered to favor the read/write learning style. In comparison, a person who learns best by participating in physical demonstrations would be said to have a kinesthetic learning style. Some researchers include the additional categories of logical, social, and solitary to define an individual's learning style, bringing the total number of styles to seven. Still others define learning styles based on the individual student's cognitive approach, using such categories as avoidant or participative, competitive or collaborative, dependent or independent. Knowing an individual's learning style helps instructors select the best method to convey information to that individual. Additionally, students of all ages can improve their ability to acquire information through awareness and use of their preferred learning style. In the workplace, knowing an employee's learning style can assist in job training and also give supervisors insight into what type of management style the employee will best respond to.
Simple Math practices for pre school kids Teaching Math for kids will be fun. Basic math like addition, subtraction should be done by replication. This application will help to parents/teachers to create worksheets a student. 1. Add student 2. Add worksheet for student by select type of problem (addition, subtraction, multiplication & division), single digit/two digits.., total problems per worksheet. 3. After creating worksheet that will be added to the student name. 5. Print the worksheet and let student do the problem. 6. After student finished the worksheet update the time and result. All the information will be stored in browser using local Storage. So information is not sync-able, will be only available on the computer. To better result make a target time for a type of problems. Example, student should finish 25 problems of single digit addition in 5 mins. Until he/she reach the target create new worksheets for that type problem. This method will help kids to remember basic Math.
Though certainly a contributing factor to most of the Tudor rebellions, political grievances were not the most significant factor in explaining the outbreak of Tudor rebellion. In the case of Wyatt’s rebellion in 1554, political grievances may well have been the most important factor due to the prospects of Mary’s marriage to Philip, England’s fear … Continue reading To what extent were political factors responsible for Tudor rebellions in the period 1529-1569? The scriptures were translated into Welsh during the reign of Elizabeth I for several reasons. These include the Queen’s personal beliefs, the influence of Protestantism and the Lutheran Reformation, and the importance of the divide in language barriers. Possibly the main reason is that Elizabeth was introducing Protestant change after the reign of Mary. William … Continue reading Explain why the scriptures were translated into Welsh The rebellion known as Kett’s rebellion broke out predominantly for economic and religious reasons. However, there are several political reasons for the outbreak. The most significant reason was economic struggles at the time. While religion became increasingly important to the rebels, it was economic issues which first sparked the rebellion. There were rumours that … Continue reading Explain why the rebellion known as Kett’s rebellion broke out The Pilgrimage of Grace was a rebellion whereby several different areas of the country were covered by different rebel groups, so it is difficult to establish one single reason why all of the risings failed. It failed for a combination of reasons: the actions of the king such as success in battle, those … Continue reading Explain why the Pilgrimage of Grace failed In around 1535 (following Henry VIII's break from Rome and marriage to his second wife, Anne Boleyn, but before he relieved her of the burden that was her head), Henry was in desperate need of cash. In a continuation of his attack on Roman Catholicism, Henry launched a campaign against the monasteries which would result … Continue reading Catching the Clergy in the Act Mary Stuart, more commonly known as Mary Queen of Scots, was believed to be the legitimate heir to the English crown presenting a threat to the Queen of England, Elizabeth I. Mary Stuart, being under threat from Protestants in Scotland, travelled to England in 1568 seeking help and protection. When Mary arrived in England, Elizabeth … Continue reading ‘Elizabeth was justified and correct to execute Mary Stuart on the grounds of the threat she posed to the Queen.’ Discuss. – Short A-Level History Style Essay
In the fusion reactor, we convert the energy from particles generated by the fusion reaction that occurs in a plasma into heat and use that heat for producing energy. In the reactor, the part called the blanket that envelops the entire plasma fulfills the role of converting the energy from the plasma into heat. Further, that heat is taken out from the reactor by using a coolant, and the heat generates energy by turning a steam turbine. In this process of removing heat and generating energy, in general, the generation efficiency becomes higher by removing the heat at higher temperature. For that reason, we must raise the temperature of the blanket. Thus, development of materials that will constitute a blanket strong at high temperatures over an extended period of time is demanded. The material to be introduced here is called a “dispersion-strengthened metal.” Typically, the nano-level gaps (of the order of one-millionth of 1mm) that are in a material produce cracks when there is movement. Then, when the temperature increases, those gaps become easier to move. When different varieties of nano-level-size particles scatter uniformly in such a material, because these particles become obstructions and the movement of gaps is suppressed, they become strong materials even at still higher temperatures. Among the dispersion-strengthened metals, there is “oxide dispersion- strengthened ferrite steel” which scattered oxide materials in ferrite steel, which is one type of stainless that is well known as a structural material. Ferrite steel is a fundamental material in the design of the fusion reactor, and is used at temperatures from 400 degrees to as high as 500 degrees Centigrade. From this ferrite steel we newly developed materials where yttrium oxide is dispersed, and we discovered that this is a strong material even at the higher temperature of 700 degrees Centigrade. Further, we have hypothesized using this material as the structural material for the advanced liquid blanket, and have shown systematically the compatibility with this oxide dispersion-strengthened ferrite steel and liquid coolant. (See the April 6, 2015, Research Update.) The dispersion strengthening method is attracting attention as an effective strengthening method that is applicable to many heat-resistant materials, and research is being conducted in research institutes around the world. In addition to ferrite steel, this is expected to be applicable to base materials such as tungsten, vanadium, and copper. The National Institute for Fusion Science, too, plans to report in Japan and abroad our research successes in dispersion-strengthened metals.
Action research design is an educational research involving collecting information regarding current educational programs and outcomes, analyzing the information, developing a plan to improve it, collecting changes after a new plan is implemented, and developing conclusions regarding the improvements. The main purpose of action research is to improve educational programs within schools. The four main types of action research design are individual research, collaborative research, school-wide research and district-wide research. Individual action research is research conducted by one teacher or staff member. This type of research is conducted to analyze a specific task. A teacher may wonder if implementing group activities within an English class will help improve learning. The teacher alone performs research by implementing a group activity for a certain length of time. After the action is performed, the teacher analyzes the results, implements changes, or discards the program if not found to be helpful. Collaborative research involves a group of people researching a specified topic. With collaborative research, more than one person is involved in the implementation of the new program. Typically, a group of students, larger than just one class, are tested, and the results are analyzed. Many times collaborative research involves both teachers and the principal of the school. This type of research offers the collaboration of many people working jointly on one subject. The joint collaboration often offers more benefits than an individual action research approach. Action research programs are generally created from a problem found within an entire school. When a program is researched for an entire school, it is called school-wide action research. For this type of action research, a school may have concerns about a school-wide problem. This can be lack of parental involvement or research to increase students' performance in a certain subject. The entire staff works together through this research to study the problem, implement changes, and correct the problem or increase performance. District-wide research is used for an entire school district. This type of action research is usually more community-based than the other types. This type may also be used to address organizational problems within the entire district. For district-wide research, staff from each school in the district, collaborates in correcting the problem or finding ways to improve the situation. Jennifer VanBaren started her professional online writing career in 2010. She taught college-level accounting, math and business classes for five years. Her writing highlights include publishing articles about music, business, gardening and home organization. She holds a Bachelor of Science in accounting and finance from St. Joseph's College in Rensselaer, Ind.
It’s the start of a new season and in episode one Shaun and Lindsay talk family. They discuss whether teaching runs in someone family before looking at how families are dealt with in ELT. Which famous family tree would use in class? Do you know what a nibling is? Just how many types of cousin are there? All this and more in our season 8 opener. End of pod activity: As your commute is coming to an end, here’s an activity you can take into class. Online, find a series of family idioms in English. Examples include: A chip off the old block The black sheep of the family Blood is thicker than water To follow in your father or mother’s footsteps Or a Marriage of Convenience Split the idioms in half, or remove key words and ask students to put them back together. Then they research the meaning of the expression, and have to say if there are similar or other expressions about the family in their language. Can they translate them into English and explain them? Almost all languages will have idioms or proverbs about the family, so this can become a good speaking activity.
Picture of Hipparchus Hipparchus was a Greek astronomer who lived between 190-120 B.C. He created the first accurate star map and kept a catalogue of over 850 stars with their relative magnitudes. The system of epicycles describing planetary motion was developed by Hipparchus, and helped preserve the geocentric model of the universe. His estimates of the moon's size and distance relative to Earth were also remarkably accurate for his time. Hipparchus is considered the founder of trigonometry for his work with the lengths of chords traced out by angles in a circle. His table of chords was the forerunner to modern trig tables. Shop Windows to the Universe Science Store! Our online store includes issues of NESTA's quarterly journal, The Earth Scientist , full of classroom activities on different topics in Earth and space science, ranging from seismology , rocks and minerals , and Earth system science You might also be interested in: How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more Ptolemy was a Greek astronomer who lived between 85-165 A.D. He put together his own ideas, those of Aristotle, and Hipparchus' system of epicycles and eccentric circles, to formulate the geocentric theory....more The Earth's one natural satellite, the Moon, is more than one quarter the size of Earth itself (3,474 km diameter), making the Earth-Moon system virtually a double-planet. Because of its smaller size,...more Archimedes was a Greek mathematician and engineer who lived between 287-212 B.C. His greatest contributions are in the field of geometry, where he identified the relationship of a sphere and cylinder's...more Aristotle was a Greek philosopher who lived between 384-322 B.C. He was one of the greatest thinkers of the world and his written works encompassed all major areas of thought: logic, science, metaphysics,...more Democritus was a Greek philosopher who lived between 470-380 B.C. He developed the concept of the 'atom', Greek for 'indivisible'. Democritus believed that everything in the universe was composed of atoms,...more Eratosthenes was an ancient Greek astronomer, geographer, and mathematician. He lived from 276 to 194 B.C. Eratosthenes is most famous for making the first accurate measurement of the circumference of...more Plato was a Greek philosopher who lived between 427-327 B.C. In 387 B.C., he founded the Academy in Athens, a school which flourished for about 1,000 years and made many important scientific and mathematic...more
The Arctic Wolf (Canis lupus arctos), also called Polar Wolf or White Wolf, is a mammal of the Canidae family and a subspecies of the Grey Wolf. Arctic Wolves inhabit the Canadian Arctic and the northern parts of Greenland. The Arctic Wolf and the Timber Wolf are the only subspecies of the Grey Wolf that still can be found over the whole of its original range, largely because in their natural habitat they rarely encounter humans. Arctic Wolf Characteristics Arctic Wolves generally are smaller than Grey Wolves, measuring around 3 to 6 feet (0.9 to 1.8 metres) long including the tail. Male Arctic Wolves are larger than female Arctic Wolves. Their shoulder heights vary from 25 to 31 inches (63 to 79 centimetres). Arctic Wolves are bulkier than Grey Wolves, often weighing over 100 pounds (45 kilograms). Weights of up to 175 pounds (80 kilograms) have been observed in full-grown males. Arctic Wolves usually have small ears, which help the wolf maintain body heat. The alpha male is always the largest and will continue growing after other wolves had stopped. Arctic wolves can be black, grey or white. Arctic Wolf Hunting Arctic wolves, like all wolves, hunt in packs. They mostly prey on Caribou and musk oxen, however, they will also kill a number of Arctic Hares, seals, ptarmigan and lemmings, as well as other smaller animals. Moose are also common prey, their long legs may render them slow and at times, stuck, in thick snow, leaving them vulnerable to attacks by wolf packs. As grazing plants are scarce, they roam large areas to find prey up to and beyond 2600 kilometres squared (1000 square miles) and they will follow migrating caribou during the winter. Arctic Wolf Reproduction Normally, only the alpha male and female Arctic wolves breed, however, in large packs others may mate as well. Due to the Arctics permafrost soil and the difficulty it poses for digging dens, Arctic Wolves often use rock outcroppings, caves or even shallow depressions as dens instead. The mother gives birth to 2 or 3 pups in late May to early June, about a month later than Grey Wolves. It is generally thought that the lower number of pups compared to the average of 4 to 5 among Grey Wolves is due to the lack of prey in the Arctic. Female Arctic wolves have a gestation period of about 63 days. The wolf pups stay with their mother for 2 years. At birth, wolf pups tend to have darker fur and their eyes have blue irises that will change to a yellow-gold or orange colour when the pups are between 8 and 16 weeks old. Though extremely unusual, it is possible for an adult wolf to retain its blue-coloured irises. Arctic Wolves have achieved life spans of over 18 years in captivity; however, in the wild, the average life span is only 7 – 10 years. Arctic Wolf Conservation Status The Arctic Wolf is classed as ‘Least Concern’. The White Wolf Sanctuary is a refuge for Arctic wolves located in Tidewater, Oregon. The average population of wolves in the sanctuary is 8 – 10 over 40 acres, of which some are rescued wolves who were injured, unwanted or abandoned.
Malaria is a common infection in hot, tropical areas but can also occur (very rarely) in temperate climates. A serious illness, malaria can cause mild illness in some and life-threatening illness in others. Malaria can be cured if treated. It is caused by parasites of the Plasmodium species, which are carried by mosquitoes infected from biting someone who already has the disease. Malaria is then transmitted to other people when infected mosquitoes bite them. Rarely, it is passed from person to person (from mother to child in “congenital malaria,” or through blood transfusion, organ donation, or shared needles). Worldwide, 300-500 million people are infected with malaria each year. Most cases occur in sub-Saharan Africa, with approximately 2 million people dying there each year. Asia, Latin America, and parts of Europe are also affected by malaria. Malaria is rare in the United States, with only about 1,300 cases reported each year over the last 10 years. Most of these cases occurred in travelers, military personnel, and immigrants who had become infected by malaria parasites outside the United States. Signs and Symptoms Early symptoms of malaria can include irritability and drowsiness, with poor appetite and trouble sleeping. These symptoms are usually followed by chills, then a fever with rapid breathing. The fever may either gradually increase over 1 to 2 days or may rise very suddenly to 105º F (40.6º C) or above. Then, as fever ends and body temperature quickly returns to normal, there’s an intense episode of sweating. The same pattern of symptoms — chills, fever, sweating — may repeat at intervals of 2 or 3 days, depending on which particular species of malaria parasite is causing the infection. Because the initial symptoms are not specific and can be mistaken for other illnesses, malaria can be difficult to diagnose. In countries where the disease is seen a lot, it’s not uncommon for doctors to treat people for malaria who have fever of no obvious cause without getting laboratory confirmation. Other symptoms of malaria include headache, nausea, aches and pains all over the body (especially the back and abdomen), and an abnormally large spleen. Convulsions or loss of consciousness may occur if malaria affects the brain. If it affects the kidneys, the amount of urine produced might be abnormally low. In falciparum malaria, caused by the Plasmodium falciparum parasite, the episode of fever and chills is especially intense, and this variety may be fatal in about 20% of cases. Once malaria parasites enter the bloodstream, they travel to the liver and multiply. Every few days, thousands of parasites are released from the liver into the blood, where they destroy red blood cells. The incubation period for malaria is the time between the mosquito bite and the release of parasites from the liver. This varies, depending on which malaria parasite is causing the disease. In general, it can range from 10 days to a month. With treatment, malaria can usually be cured in about 2 weeks. Without treatment, it can be fatal, especially in children who are poorly nourished. Health authorities try to prevent malaria by using mosquito-control programs aimed at killing mosquitoes that carry the disease. If you travel to an area of the world with a high risk for malaria, you can install window screens, use insect repellents, and place mosquito netting over beds. Insecticide-impregnated bed netting has successfully reduced the number of malarial deaths among African children. Check with your doctor before visiting any tropical or subtropical area at high risk for malaria. Your doctor can give your family anti-malarial drugs to prevent the disease, which need to be taken prior to travel. Several malaria vaccines are currently being developed and tested across the world, but because the malaria parasite has a complicated life cycle, it is a difficult vaccine to develop. Diagnosis and Treatment Doctors diagnose malaria by using special blood tests. A blood sample is sent to the laboratory and checked under a microscope for malaria parasites, which may be seen inside infected red blood cells. Malaria is treated with anti-malarial drugs, such as chloroquine or quinine, given by mouth, by injection, or intravenously (into the veins). Depending on the type of parasite causing the malaria, a person can be treated as an outpatient over a few days or may require hospitalization with IV medication. Doctors also watch for signs of dehydration, convulsions, anemia, and other complications that can affect the brain, kidneys, or spleen. The patient may require fluids, blood transfusions, and breathing assistance. Malaria is a leading cause of death worldwide. It’s important to tell the doctor if there has been any travel to areas where malaria is present. If diagnosed early and treated, malaria can be cured. However, many people who live in areas where malaria is common get repeated infections and never really recover between episodes of illness. Reviewed by: Yamini Durani, MD Date reviewed: July 2012
From the middle of the third to the end of the second centuries B.C., the adult male population was estimated to have risen from about 200,000 to 400,000 individuals. Those numbers, however, don't jibe with censuses organized by the first emperor Augustus in the first centuries B.C. and A.D., which showed a population that had increased to about 4 million to 5 million males. While the granting of citizenship to allies on the Italian peninsula accounts for some of the increase, there is still an estimated unexplained doubling or tripling in the Roman population before the first Augustan census in 28 B.C. Just what accounts for that increase is a matter of intense debate. One camp explains the discrepancy by suggesting that the Empire began counting women and children in the census. While this would account for the relative increase, it would actually imply an overall decline in the population of Rome and there are no suggestions that the entire populace was counted in historical records. On the other side of the debate are those who suggest that the population simply boomed. This would mean that the Roman Empire — and other premodern societies — achieved much higher economic output than previously supposed. It would mean that Roman history as it is now understood would have to be rewritten. The resolution of this debate was found in buried treasure. Two university professors, Peter Turchin of the University of Connecticut and Walter Scheidel of Stanford University, turned their attention to coin hoards — treasure that families buried during times of conflict and then were unable to later recover. Turchin and Scheidel reasoned that by compiling a record of such hoards, and the times in which they were buried, they could learn a great deal about population trends. Their findings? The population of Rome declined after 100 B.C. and the estimates of a population of 4 to 5 million people was, in fact, the entire population of the Roman Empire and not simply a count of the male population. As LiveScience.com quotes Scheidel: "This may seem like an arcane dispute, but it isn't really because the difference is so large — 200 percent.... This model is much more consistent with the low count. I'm not sure that by itself it has absolutely proven it, but it certainly provides additional evidence for the low-count hypothesis." What is interesting is that it also means that if Turchin and Scheidel are correct in their analysis, even as Rome grew in wealth and power, the population of the empire fell. The demographic winter that is afflicting our powerful, wealthy but also increasingly spiritually empty society may echo the experience of an early culture that moved from being a republic to a "multi-cultural" empire.
We take it all for granted. Keeping all your memories on a little device called the mobile phone, having a plethora of books on your e-reader, and what-not. But behind all the magic is a wonder of material science, quantum physics, and magnetism. What is the working principle behind hard disks, what is it made of and how has it evolved over time?! Hard disks are a collection of circular platters mounted on a cylinder. These disks have a magnetic surface that stores information. The surface comprises of several ‘magnetic grains’. These grains are grouped and each group is known as a ‘bit’ or ‘binary digit’. The grains of a bit have a particular direction. Bits with grains in one direction are taken as the 1s while the ones with the other direction are taken as the 0s. 1s and 0s collectively give information in binary. This can be rendered in human-readable form. For instance, the letter J would have a binary value of 01001010. These circular platters are constantly rotating. When you write on a disk, data is fed into disks by converting strings of bits onto electric current by a high power electromagnet. This electromagnet generates a field strong enough to change the direction of the magnetic grains’ magnetization. For reading, a magnetic reader converts this back to an interpretable format. The primary method to increase disk storage capacity is to increase the number of bits that can be stored on a disk. Since the introduction of hard disks by IBM in 1957, the disks’ areal capacity has increased 300 million times! Today’s modern day disks can store about 600 gigs per square inch. Pretty neat, huh?! This transformation has taken a massive amount of research. The reader and writer were made smaller and more sensitive, and development in material sciences and quantum physics have made metallic grains smaller.

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