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Download a print version of this document: Cryptosporidium (PDF: 38.78KB/2 page) In April 1993, an intestinal parasite called Cryptosporidium was responsible for a major outbreak of illness in the city of Milwaukee, Wisconsin. More than 400,000 people became ill after drinking contaminated water from the city water supply system. Most of these people recovered on their own, but those with compromised immune systems were sometimes unable to fight off the disease. It is now believed that as many as 100 people may have died as a result of this incident. Since that time, water systems across the country have been taking extra precautions to make sure such an incident does not occur in their communities. A variety of measures can and are being taken. Providing information is an important part of this effort. Information about this illness can help you protect yourselfand thats especially important for people who have conditions that may compromise their immune systems. This fact sheet provides information on Cryptosporidiumwhat it is, whats being done about it, and what you can do to avoid becoming ill. Although Cryptosporidium is not new, it has been recognized as a health threat for a relatively short timethe first known cases of illness in humans date from 1976. Because of what happened in Milwaukee, increased concern has been focused on the issue. Intensive efforts have been underway to measure the risks associated with Cryptosporidium contamination in drinking water with steps being taken to reduce them, including new regulations that strengthen the requirements for public water systems using surface water as their source. What is Cryptosporidium? Cryptosporidium is a protozoana slightly more complex type of organism than a bacterium or virus. It can live in the intestines of humans or animals. Of the six known species of Cryptosporidium, Cryptosporidium parvum is thought to pose the greatest threat of human infection. Outside of the body, Cryptosporidium is protected by an outer shell called an oocyst. Once the oocyst is consumedin food or waterthe organism can emerge from the shell and infect the lining of the intestine, causing an illness called cryptosporidiosis. The symptoms include diarrhea, nausea, vomiting, and abdominal cramping. The illness usually begins two to ten days after infection and generally lasts for no more than several weeks for people with normal immune systems. However, for people with compromised immune systems, the illness may be more persistent and more severeeven fatal. People with compromised immune systems can include those living with HIV or AIDS, as well as cancer patients receiving chemotherapy. The principle source of Cryptosporidium contamination is believed to be animals, both domestic and wild. Cryptosporidium is relatively widespread in the environment and is commonly found in rivers and lakesespecially when the water is contaminated with animal wastes. Based on the results of national sampling and testing efforts, it is likely that some amount of Cryptosporidium contamination can probably be detected in most water supply systemsif they get their water from surface water sources (lakes, rivers, or streams) and if enough samples are taken. Whats being done to protect our drinking water in Minnesota? Oocysts can survive chlorine treatment, which means that Cryptosporidium resists conventional disinfection methods. The water must be filtered in order to remove Cryptosporidium. Most public water systems in Minnesota use wells to get their water from under the ground. These groundwater systems have a built-in advantage in the fight against Cryptosporidium: the ground itself serves as a natural filter as the water percolates from the surface down to the aquifer. Twenty-four community water systems and approximately 60 noncommunity water systems in Minnesota use surface water as their source of drinking water. Surface water is open to the environment and more susceptible to contamination. However, all surface water systems in Minnesota use filtrationwhich removes Cryptosporidiumas part of the treatment process. Monitoring requirements must be met, and the water system must be operating at optimum levels at all times so that a breakdown does not occur at this critical point in the treatment process. There are new regulations in place for public water systems that use a surface water source. These regulations aim to improve public health protection through the control of microbial contaminants by focusing on systems with elevated Cryptosporidium risk. To determine if a surface water source is vulnerable to contamination, surface water systems are required to monitor their source water for Cryptosporidium. Based on the annual average of these results, additional treatment may be required. However, due to the high cost of Cryptosporidium analysis, surface water systems serving less than 10,000 people are eligible to conduct E. coli monitoring in lieu of Cryptosporidium monitoring. If the annual average of the E. coli results exceeds specific trigger levels, then Cryptosporidium monitoring will be required to determine if additional treatment is required. The Minnesota Department of Health (MDH) is one of only four sites in the United States chosen to participate in a federally funded Emerging Infections Program. As part of this program, MDH is conducting surveillance for cryptosporidiosis so that if outbreaks occur, they can be detected early. Treatment systems follow a multi-barrier approach in dealing with Cryptosporidium It’s important to remember that monitoring for Cryptosporidium (or E. Coli) will detect pathogens only after they are already present. For that reason, system operators need to make sure their treatment facilities are functioning efficiently and effectively at all times. To protect against Cryptosporidium and other waterborne diseases, the public water systems use a multi-part strategy that includes: - protecting the source water and supporting watershed management efforts. - using the most effective possible treatment methods. - making sure the water distribution system is properly maintained. - conducting the required water quality monitoring for the treated water and the distribution system. What you can do to protect yourself People with compromised immune systems may want to consult with their clinicians and consider special precautions, such as those listed below, any time there are questions regarding the safety of their drinking water. Boiling the water for one minute (and allowing it to cool before drinking) is the best extra measure that can be taken to make sure water is free of Cryptosporidium and any other germs. People should also avoid drinking or accidentally swallowing water from rivers, lakes, streams, or swimming pools. People with compromised immune systems should avoid swimming in rivers, lakes, and perhaps even swimming pools (oocysts are not killed by chlorine) since accidental water ingestion often occurs with swimming. Alternatives to boiling water include switching to bottled water or installing point-of-use water treatment devices. Bottled water is subject to fewer regulatory safeguards than water from your public water supply system, however, and its quality can vary. Unless it has been distilled or pasteurized, bottled water may not be any safer than tap water. If the bottling company gets its water from a properly designed and operated groundwater system, its unlikely that there will be any Cryptosporidium in the water. Point-of-use filters are effective against Cryptosporidium if they are capable of removing particles one micrometer or less in diameter. Also, devices that use ultraviolet technology are effective for inactivating the organism. When selecting a treatment system for the removal of Cryptosporidium, be sure to select a device that is ANSI/NSF certified for the technology being used. Also, when using any type of treatment device, it is important to maintain it properly and when using a filtration device, change the filters at regular intervals. Failing to maintain a treatment unit will reduce its effectiveness and may even make contamination problems worse. For more information: Contact the Minnesota Department of Health Drinking Water Protection Section at 651-201-4700.
Women are From Mars: Closing the Gender Gap in Space by Maria Perica 13 years ago, the beginning of February was met with horrifying news from NASA: the space shuttle Columbia disintegrated upon reentry into the atmosphere, killing all 7 crew members. This disaster is commemorated every year, but lately, NASA has shared some more cheerful news with us regarding the first manned mission to Mars. 46 years after the first man walked on the surface of the moon, NASA has started the process of selecting the first man to walk on Mars, and it looks like it may actually be a woman. For the first time ever, NASA’s latest class of astronauts is 50% female. The gender gap in STEM is slowly closing as the predominantly male, high-level positions in biology, physics, and engineering, are increasingly including women. This exciting news hints at advancements in closing this gap in space travel. Progress in this field has been encouragingly rapid; female astronauts were not even considered as applicants in the 1960s when astronauts were applying to man the Lunar Mission. The team has been training since 2013, and will soon join NASA’s 46 other active astronauts. The journey to Mars is about 25 million miles, which will take anywhere from six to nine months. Phase One of the mission to Mars is called Earth Reliant, and involves seeing how astronauts on the International Space Station survive without being bound to Earth. Phase Two involves the perfecting of complex operations that are needed in a deep-space environment. Only then will NASA be able to move onto phase 3, which is Earth Independent – the manned mission to Mars. NASA hopes to send these hopeful astronauts into space in about 15 years.
Here is an Audio Clip taken from "http://cc636243-a.twsn1.md.home.com/sond0107.htm" Can you handle the truth? Perhaps a better question is just exactly what makes something true? The goal of this lesson The purpose of this short lesson is to acquaint you with a philosophical orientation to learning referred to as "constructivism" and to consider its implications to education. After you finish this lesson, you should be able to: A short exercise To begin, I'd like you to complete a little exercise. It begins with two questions: Hopefully, you can complete this with two or three friends or classmates. Take a few minutes to compare your answers. Many people come up with all sorts of interesting statements of fact, ranging from mathematics (e.g. 2+2=4) to language (e.g. each sentence must contain a subject and a verb) and history (e.g. Columbus discovered America in 1492). However, there is one final question I would you like you to answer: This is a rather unnerving challenge. So many things we accept to be true without really questioning the validity of the statements. Good examples come from math and science, such as the world is round and it travels around the sun. I read somewhere that someone once asked the philosopher Ludwig Wittgenstein how it could have been people could have been so stupid to have believed that the sun revolved around the earth. He is said to have responded, "I agree, but I wonder what it would look like if the sun really did revolve around the earth?" The point being, that it would look exactly the same. Do you agree with this "fact"? Here's one fact that I dare say would be judged by most people as being true beyond refute: "The sum of the interior angles of any triangle equals 180 degrees." This is something we all learned in school. But how do you know it to be true? You could draw a triangle on a sheet of paper and measure the angles. But this is just one triangle, how do you know it to be true of all triangles? So, you draw many triangles, measuring each one carefully. Perhaps you even use a tool such as Geometer's Sketchpad which allows you to construct and test literally thousands of triangles in a matter of seconds. But those are just small triangles drawn on paper or the computer screen,. How do you know it to be also true of large triangles? Perhaps you take some string and construct triangles that fill a table, a room, or someone's backyard. But these are still relatively small triangles, what about really big triangles, measuring miles along a side? Let's jump to an extreme case. If you start at the north pole and stretch a piece of string to the equator, turn left 90 degrees, walk around one quarter of the way around the globe, then turn left 90 degrees again you will eventually find yourself back at the north pole. The triangle you have constructed will have three interior angles measuring 270 degrees! Of course, you will say that I have tricked you and that the curvature of the earth got in the way. That argument only makes sense when you have a certain perspective on things, because as you are pulling the string, it certainly appears straight from where you are standing. A new perspective or understanding can lead to a changing of the "truth." (Incidentally, this is not really a trick. Einstein's General Theory of Relativity, as I understand it, says that space is curved in the presence of a gravitational field, so the angles of triangles, even as you originally understand them, do not really measure 180 degrees.) This is a good point to bring up the concept of "viability versus truth," because many ideas are viable in the everyday world and ought to be taught. Another good example is Newton's laws of motion. These are still viable, even though they are no longer considered "true" by physicists, because they have practical uses. So, as our understanding of something increases, truth itself can change. The phrase "You are what you know" aptly captures the importance of epistemological questions, such as "what does it mean to "know" something?". However, curricular questions about what should be taught and why are not always perfectly aligned with the "truthfulness" of the content. However, there remain appropriate reasons to teach certain content in schools even through they are no longer accepted as true (i.e. Newton's laws of motion) because the ideas remain useful and meaningful in many contexts. In other words, the ideas are viable. However, a constructivist teacher is more concerned about the meanings that his/her students have about content and seeks to use these meanings as the seeds for greater understanding. A constructivist teacher knows that "teaching" is really a misnomer -- one cannot really teach something to somebody else (a la pouring information into somebody's head). In a sense, individuals teach themselves in a social context. Instead, a teacher's responsibility is to facilitate learning by providing lots of interesting opportunities for meanings to be formed, shared, and discussed. This does not mean that education should be a "free for all" where all ideas have equal standing. The concept of viability shows that some ideas are more viable than others under certain conditions. But this is a very different attitude that simply saying that students are "wrong." Do you wonder what would happen if you could change the philosophy of school? What would the institution of "school" look like if its philosophy changed to constructivism? Would there even be schools? Here's a chance to learn more about the implications of these philosophies on educational practice. Instead of just reading about it, here is a light-hearted simulation of these principles for you to experience. In groups of two or three, discuss the concepts expressed in this lesson. Here are some possible questions to consider: (I hope, by now, that the irony of designing a lesson about constructivism has not been lost!) Read this short chapter by ErnstVon Glaserfeld. It explains and discusses the concept of viability: Read this chapter by me (Lloyd Rieber). It explains and discusses constructivism in the context of instructional technology:
Every country has a constitution of some sort that outlines the government’s structure. A constitution is simply the set of rules that govern how power is distributed and exercised. In other words, these rules structure the government of a state. Without such a set of rules, the state could not function and anarchy would reign. Although no constitution can cover every possible question or issue, all states need to spell out at least the fundamental matters of the distribution and use of power. Some constitutions—such as that of the United States or the Basic Law of Germany—are codified into written documents. In other states, such as the United Kingdom, the constitution consists of many documents, laws, court rulings, and traditional practices that have never been compiled into a single document. But in every case, custom, history, and tradition play an important role. Strong constitutions share three characteristics, or principles, of constitution design: Example: The U.S. Constitution has been amended nearly thirty times, allowing Americans to adapt their structure of government to changing mores, beliefs, and practices. The Bill of Rights was the first set of amendments. Other amendments include the Thirteenth Amendment, which made slavery illegal in 1865, and the Nineteenth Amendment, which gave women the right to vote in 1920. Although these three principles of constitutional design help ensure solid governmental structures, ultimately they are merely guidelines. Some successful constitutions do not include them, and a number of states have succeeded in imposing governments that differ greatly from tradition. Unfortunately, any radical departures from tradition or history usually require violence. Example: After a fourteen-year war to gain independence from Portugal, Angola entered into a decades-long civil war to determine which ethnic political party would head the country. Intervention from other nation-states, which favored one party over another and wanted to see their favorite gain dominance, exacerbated the violence. Some constitutions are short documents. The U.S. Consti-tution, for example, covers only a few pages. Others are lengthy. The Basic Law of Germany, for example, is roughly five times as long as the U.S. Constitution. As a general rule, older constitutions are shorter than newer constitutions. Example: In the United States, state constitutions are frequently far longer than the federal one, which was ratified in 1789. In part, this is because most state con-stitutions were written after the federal one. Even states that predate the federal Constitution have rewritten their constitutions, sometimes more than once. Constitutions, particularly short ones, tend to be vague in their contents. Vague constitutions have two advantages: Example: The vague U.S. Constitution has encouraged political leaders to work together through congressional committees. These committees have become a hallmark of the American democratic process.
Mapping Latin America A Cartographic Reader For many, a map is nothing more than a tool used to determine the location or distribution of something—a country, a city, or a natural resource. But maps reveal much more: to really read a map means to examine what it shows and what it doesn’t, and to ask who made it, why, and for whom. The contributors to this new volume ask these sorts of questions about maps of Latin America, and in doing so illuminate the ways cartography has helped to shape this region from the Rio Grande to Patagonia. In Mapping Latin America,Jordana Dym and Karl Offen bring together scholars from a wide range of disciplines to examine and interpret more than five centuries of Latin American maps.Individual chapters take on maps of every size and scale and from a wide variety of mapmakers—from the hand-drawn maps of Native Americans, to those by famed explorers such as Alexander von Humboldt, to those produced in today’s newspapers and magazines for the general public. The maps collected here, and the interpretations that accompany them, provide an excellent source to help readers better understand how Latin American countries, regions, provinces, and municipalities came to be defined, measured, organized, occupied, settled, disputed, and understood—that is, how they came to have specific meanings to specific people at specific moments in time. The first book to deal with the broad sweep of mapping activities across Latin America, this lavishly illustrated volume will be required reading for students and scholars of geography and Latin American history, and anyone interested in understanding the significance of maps in human cultures and societies. 360 pages; ISBN 9780226921815 , or download in Title: Mapping Latin America Author: Jordana Dym; Karl Offen
They have a spin of 1 (except for the Higgs boson, which has no spin). Importantly, they can stack on top of one another. They have no charge (except for the W bosons which can have a charge of either +1 or -1 They each carry (or "mediate") a specific type of force: - photons: electromagnetic force (which mediates: electricity, magnetism and the interactions between electrons) - gluons: the strong nuclear force (which holds quarks together, eg inside protons & neutrons and by a mechanism that is described by "quantum chromodynamics") - W and Z bosons: the weak nuclear force (a helper force that's involved in beta decay - beta decay is mentioned on the page describing how one quark can change into another) - Higgs bosons: associated with the Higgs field A particle which hasn't yet been discovered is the graviton - the force particle that is predicted to be involved in gravity
Feeling that gross, phlegmy, “mucus in chest” feeling? It’s an uncomfortable feeling, but there’s a reason it happens. Mucus is a secretion produced by, and covering, mucous membranes which surround all major organs. Mucous fluid is normally produced from cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. The major function of mucus is to protect the body from fungi, bacteria and viruses. The mucus in the lungs and respiratory tracts traps foreign dust particles and bacteria to protect the body from disease. Why does mucus form in the chest? We think of mucus as only lining our nose. But in fact, our nose, mouth, trachea, sinuses, lungs and gastrointestinal tracts are all lined with mucus secreting cells. A healthy individual produces 1-1.5 litres of mucus every day. Excessive mucus is secreted by the mucosal sacs due to a bacterial or a viral infection or an allergy. Allergies due to triggers like pollen or dust lead to congestion and nasal stuffiness. Due to allergies, mast cells in our body secrete a substance known as histamine which leads triggers sneezing, itching, and nasal stuffiness. This leads to the excessive secretion of mucus, leading to chest congestion. There are various remedies for how to relive chest congestion click here to read more When we develop a cold, mucus develops in our chest due to our immune system’s reaction. The immune system produces mucus to expel the disease causing pathogen from our body. Does mucus have a purpose? Mucus has a very important function in maintaining the health of our body. Mucosal sacs line the inside of our respiratory and gastrointestinal tracts. They secrete mucus to keep the epithelium lining them moist and hydrated. Without mucus, they will dry out and crack. The mucus lining in our oesophagus helps with peristalsis. Peristalsis are the wave like contractions along our gut that help food reach the duodenum of the small intestine. Mucus also reduces the friction between the organs in the body by making sure they slide against each other. Mucus also serves as a barrier against harmful substances in the air that we breathe. Irritant particles, bacteria and virus stick to the sticky surface of the mucus, preventing them from going any further in our body. The mucus is then swept away by the cilia in the aforementioned tracts. Is mucus harmful? Excessive mucus is harmful to us. Excessive mucus blocks our bronchial tubes and trachea, making it very difficult to breathe in and out. This difficulty in breathing leads to wheezing, soreness in the chest and a cough. Such symptoms cause the body to tire out. In case of excessive mucus build up, it is very important to take in plenty of fluids as our body can tire out. The presence of excessive mucus can be dangerous to our health. Abnormal coughing can lead to emphysema. Coughing can cause the alveolar sacs in the pleural cavity to coalesce, reducing the surface area for gaseous exchange to take place. This leads to small amounts of oxygen being taken in by our body. The lack of oxygen inhibits our body’s ability to carry out its normal functions and we tire easily. If your problem persists even after using the best nasal sprays, then consult your doctor immediately.
invented in 1914 by Dr. E. E. Fournier d’Albe, then a lecturer in physics in the university of Birmingham. It is based upon the properties of selenium, an element which is a better electrical conductor in light than in darkness. A beam of light is rendered intermittent by the interposition of a revolving siren disc and is then concentrated into a small bright point on the paper to be read. If the point on the paper is white, it will reflect the light; if it is black it will not. A selenium cell placed close to the paper, on receiving the reflected beam of intermittent light, will respond to each flash by a change in conductivity, and if the frequency of the flashes is of the “musical” order (between 30 and 30,000 flashes per second), a telephone receiver connected with the selenium and a battery will sound a musical note. A blind person could thus tell whether the paper is black or white. That is the principle of the optophone. In practice a small row of luminous points is substituted for a single point, and each point in the row is given a different frequency by suitably perforating the siren disc. The row, usually of five or six points, just fills up the size of the tall letters of the print to be read. When the whole row falls upon the black stem of a letter there is silence in the telephone. As the letters pass their various shapes are indicated by the sounding or silence of the different notes, and after some practice the blind person learns to recognize letters from their sounds, and so to read ordinary type. The first reading test was given by the inventor in March 1917, the matter read being a leading article in The Times. In Aug. 1918, Miss Mary Jameson, a blind pupil from Norwood, gave the first public reading demonstrations, reading an unknown page from a book at a speed of about two words per minute. Later, with an improved instrument, she attained a speed of about 20 words per minute. A new type of optophone was brought out in 1920 by Barr & Stroud, of Glasgow. In this instrument two selenium cells were used, balanced against each other in such a manner that white paper produced silence, and the black letters themselves made the musical sounds. Reading demonstrations were also given with this instrument, but any advantage in the way of ease of reading was found to be counter-balanced by a greater delicacy and complexity of adjustment. The new type is known as the “black-sounder,” and the original type is termed the “white-sounder.” The latter type was approved by the Inventions and Research Committee of the National Institute for the Blind in 1921 after an exhaustive series of tests. The optophone is intended to place the world’s printed literature once more within reach of the blind. It is applicable, without special preparation, to any language, and can also be used for reading typescript, but not handwriting. See “A Type-reading Optophone,” Roy. Soc. Proceedings (1914); “The Optophone,” Journal of Roy. Soc. of Arts (1921); “The Optophone,” St. Dunstan's Review, No. 55 (1921). Orange Free State (see 20.151), a province of the Union of S. Africa. At the 1911 census it had a pop. of 528,174 compared with 387,315 in 1904—an increase of 26.67%. Whites numbered 175,189, coloured 352,985. In 1918 the white pop. was 181,678. The increase in pop. since 1904 was very largely due to the development of agriculture and stock farming, the province being essentially a pastoral region. The only big town is the capital, Bloemfontein (pop. in 1911 26,925). While new settlers included many of British origin, the white inhabitants remained predominantly of Dutch descent. Nearly all the coloured people are Bantu and in 1911 the province had only 108 Asiatics. A higher proportion, 50.77 %, of the natives professed Christianity than in any other province of the Union. There were in 1918 only 5,588 persons (all races and both sexes) engaged in factories in the province, but in Jagersfontein it possesses one of the chief diamond mines in S. Africa, and there is a group of small but rich diamond mines in the Boshof area, proclaimed in 1906, 1910 and 1912. There are coal mines by the Vaal at Vereeniging, which produced 469,000 tons in 1910 and 838,000 tons in 1919. Dr. A. E. W. Ramsbottom was the first administrator, being succeeded by Mr. H. C. Wessels. Both had been members of the Ministry during the brief period (July 1907–May 1910) while the province had been a self-governing colony. The provincial administration at first continued the system of compulsory bilingual education enforced in 1908, but the struggle conducted by the English-speaking part of the people over the medium of instruction came virtually to an end in 1912, the provincial council having adopted, in the main though still with a bias in favour of the Dutch language, the proposal suggested by the Union Parliament that up to standard IV. instruction in the schools should be given in the “home language” of the scholar. In 1920 an ordinance was passed recognizing “Afrikaans,” i.e. the Taal or colloquial Dutch, as equivalent to Netherlands Dutch as a medium of instruction, and its adoption, for Dutch scholars, was very general. In most respects the provincial administration was progressive and was conducted on non-party lines. (For the administrative system see Cape Province.) Provincial expenditure rose from £511,000 in 1912–3 to £611,000 in 1917–8, the amount spent on education in the years named being £250,000 and £473,000 respectively. The province was the stronghold of the Dutch Nationalists. Up to his death in 1916 ex-President Steyn, who lived near Bloemfontein, though he held no office, exercised very great influence on public affairs. In the crisis caused by the World War Steyn opposed operations against German S.W. Africa. There followed the rebellion of Gen. De Wet, the Free State being the principal theatre of the campaign. Gen. Hertzog, the parliamentary chief of the Dutch Nationalists and after Steyn’s death their undisputed leader, carried the Free State in the elections of 1915, 1920 and 1921. In Feb. of the last-named year, when he had declared for the secession of the union from the British Empire, his party won 16 out of the 17 constituencies into which the province was divided (see South Africa). ((F. R. C.)) Ordnance (see 20.189.)—(I.) Principles of Design. The principal requirements from a gun are accuracy, high muzzle velocity and high remaining velocity at any given range. These points are dependent on the ballistics, or power, of the gun, on the twist and form of the rifling, and on other factors outside the gun, such as the weight and shape of the projectile and the design of the driving-band on the projectile. At the same time as definite conditions are laid down for these main requirements, certain limitations are imposed upon the designer in connexion with the working pressures in the gun, the length and weight of the gun, the feasibility of repair, and the length and weight of the projectile. These various factors must be considered from the point of view of their relation to each other as they are to a very large extent interdependent, and variation in any one of them will react on one or more of the others. The limiting factor in the working pressure is the strength of the gun to resist the firing stresses, and any increase in these beyond a certain limit will necessitate a corresponding increase in the strength of the gun, that is, in the amount of material employed in its construction, which obviously entails an increase in the weight of the gun, a very important consideration. The length of the gun has an important effect on ballistics, and any increase in this respect not only is accompanied by increased weight but also affects the question of the space occupied, another important consideration. Further, any variation in the weight or length, or both, of the gun will affect the position of the centre of gravity, and so affect the design of the mounting or carriage. Another aspect of the question of length is its effect upon the “girder strength” of the gun. In modern ordnance efforts are made to place the centre of gravity as near the breech as possible, and, the gun being supported on its mounting at or near this point, with long guns a considerable proportion of the total length remains unsupported, and therefore has a tendency to “sag” due to its own weight. Theoretically a longer gun gives better ballistics, but in practice the length of modern guns is usually 45 to 50 calibres; though this has been sometimes exceeded in what may be termed “freak” guns, and may in future be exceeded in hyper-velocity - Acknowledgment is due, for the illustrations in this article, to Messrs. Armstrong, Whitworth & Co.; Messrs. Schneider, Ltd.; Messrs. Pavesi & Co.; Messrs. Vickers, Ltd.; the Editor of Mechanical Engineering; the Royal Carriage Department, Woolwich; the Royal Artillery Institution, Woolwich; and the U.S. War Department.
DE.6. Life Processes 6.2. Matter and Energy Transformations Enduring Understanding: All organisms transfer matter and convert energy from one form to another. Both matter and energy are necessary to build and maintain structures within the organism. 6.2.C. Most living things use sugar (from food) and oxygen to release the energy needed to carry out life processes (cellular respiration). Other materials from food are used for building and repairing cell parts. (Level: Important) DE.7. Diversity and Continuity of Living Things 7.1. Reproduction, Heredity and Development Enduring Understanding: Organisms reproduce, develop, have predictable life cycles, and pass on heritable traits to their offspring. 7.1.F. Chromosomes are found in the nucleus of the cell and contain genes that are made of DNA. Inherited traits of individuals are controlled by genes. (Level: Essential) 7.1.H. In humans, gender is determined by a pair of sex chromosomes. Females possess two X chromosomes; males an X and a Y chromosome. The sex of an embryo is determined by the sex chromosome found in the sperm cell. (Level: Important)
Light from this supernova, called supernova 1987a, first reach earth in 1987. It occured in a nearby galaxy and was the closest supernova since the invention of the telescope. The Hubble Space Telescope took this picture of supernova 1994. Credit: NASA, P.Challis, R.Kirshner (Harvard-Smithsonian Center for Astrophysics) and B. Sugerman (STScl) Burning a billion times brighter than our sun, the phenomena called supernovas have unlocked mysteries about black holes, the origin of metals such as gold and the expansion of the universe. Supernovas are rare -- the last supernova seen in our galaxy was recorded in 1604, according to NASA. Although this supernova may have baffled those living at the time, by observing supernovas in other galaxies, astronomers now understand what a supernova is the final explosion of a massive, dying star. What happens during a supernova All stars, including our sun, will eventually run out of the hydrogen gas that fuels the nuclear fusion reactions in their cores. When this happens, smaller stars expand into what astronomers call red giants, then shrink into faint white dwarfs, according to NASA. But massive stars, that have at least five times the mass of the sun and can be much larger, are likely to become red supergiants and explode in supernovas. Forces at work within stars are what give rise to the explosion seen during supernovas. For most of a star's life, gravity pulls its gases inward, but its nuclear reactions push the gases outward, and the forces engage in a constant tug-of-war. But when the nuclear fusion in a star stops, the star loses the outward push that countered gravity. Gravity then takes over, and the star begins to collapse in on itself. Eventually, the force of the collapsing material heats up the star's core enough to start a series of new nuclear reactions, forming heavier and heavier metals, until the core becomes solid iron and nuclear reactions stop. Within a second, the iron core's temperature rises to more than 180 billion degrees Fahrenheit (100 billion degrees Celsius), crushing the iron atoms closer together until the core explodes in a shock wave. This explosion is a supernova. Supernovas may leave behind a brilliantly colored cloud of gas called a nebula, a black hole or perhaps nothing at all. But that just explains Type II supernovas. Type I supernovas involve a complex interaction between a pair of a binary stars where one star eventually explodes, according to NASA. What supernovas reveal In February 2006, researchers observed an unusual supernova 440 million light years away. As it exploded, the supernova released an intense flash of X-rays called a gamma-ray burst. Previously, scientists thought gamma ray bursts only formed from spiraling matter falling into black holes. As more research is done into supernovas, scientists have also used the phenomena to study the entire universe. A subtype of supernovas, Type Ia, are among the brightest things in the universe, and all shine with roughly equal intensity. So by observing supernovas over time, researchers in the 1990s were able to see that the supernovas were all moving away from the center of the universe at an increasing rate, showing the universe was expanding. Scientists call the unknown force behind the expansion dark energy. In April, the international Supernova Cosmology Project (SCP) at the Lawrence Berkeley National Laboratory announced the largest collection of data on supernovas yet amassed, to continue studying dark energy. Got a question? Email it to Life's Little Mysteries and we'll try to answer it. Due to the volume of questions, we unfortunately can't reply individually, but we will publish answers to the most intriguing questions, so check back soon.
For over 50 years, humans have been actively launching spacecraft and satellites into space, often without considering what happens to the remaining debris or how to remove inactive satellites from the crowded orbits. This video takes a look at the issue and the measures put in place by the European Commission to address the challenge. Although the Sun is 150 million kilometres away from us, any activity on its surface can not only impact life of astronauts operating in the International Space Station, but can also directly affect and disturb our daily lives on Earth – satellites, infrastructures and normal functioning of telecommunications. This video highlights the work of the European Commission to ensure space experts and researchers will be able to predict and mitigate the potential destructive impact of space weather on our lives. Satellites collect a vast amount of data from space. Often collected in raw status, the datasets need to be processed in order to become valuable and meaningful information to the scientific community at large. The video shows the commitment of the EU to support a wide range of space research projects funded under the EU FP7 in order to ensure the exhaustive exploitation of valuable space data.
Accessibility is the successful access that people with disabilities have to content and spaces. As I mentioned at the end of Accommodation versus Inclusive Design, I concluded that accessibility is a mismatch between the design and a user’s needs. On the web (or with ICT – information and communication technology) we can create that match by starting with W3C’s web content accessibility guidelines (WCAG). The 4 principles of WCAG are: - perceivable: broadening the sensory experiences to include sight, sound, and touch, - operable: all interactive components and navigation are navigable and usable, - understandable: content, component functionality, and design are easy to understand, and - robust: content & functionality is compatible with a variety of browsers, devices, and assistive technologies. Challenges on the web I won’t go into further detail about all its success criteria just because I’ve written quite a bit about them while studying for the WAS exam. However, I do want to mention some common challenges that people face when on the web, and how accessible design can help designers and developers be aware of how to address these barriers. \|Video & audio\|\| Universal design can help Universal design creates products and environments that the vast majority of people can use, taking into account the natural physical diversity among people. Universal design doesn’t just think about people with disabilities, it thinks about a lot of people. By expanding our view from accessible design to universal design, we can make a more usable experience for a lot more people. Stay tuned for my next post that will go further into universal design, its origins, and its solutions in the context of the physical world.
As the number of teens and young children using the Internet rise, so are the incidents of cyberbullying. Since censoring or banning specific forms of online speech is not possible, it is up to parents to understand what cyberbullying is and how to protect their children. What is Cyberbullying Cyberbullying is the technology equivalent of playground or neighborhood bullying. There are no sticks or stones involved, however; the bullying is all on a psychological level. Children being bullied cannot go home and avoid the rumors or taunts; it is all waiting for them online as much as being spread at school or in social circles. Social networking sites such as, Facebook and Twitter are prime locations for bullying comments. Kids, especially teens, use these services as ways to establish either who they are or who they want to be. These sites can also easily promote the common adolescent behavior of bullying. Cyberbullying is not confined to Internet sites. Text messages can also become sources of unwanted, demoralizing comments. How to Protect Teens From Cyberbullying Parents are in a unique position in regards to their children’s online behavior. Being involved in the behavior of children, including teens, when they are involved with the Internet or text messaging is not legally considered a violation of their free speech. It is parents’ responsibility to educate children about acceptable behavior. This is similar to asking kids where they are going after school or where they have been when they return home. Parents and other adults can monitor kids’ digital activities through an active presence or by using monitoring software. It is important to be involved in their recreational activities, even when the child is a teen, in order to help them understand both their responsibilities as emerging adults and the consequences of their actions and decisions. Monitoring software can be useful for verifying activities while parents are not home, or to block sites deemed to be inappropriate. It is also advisable to watch for signs of cyberbullying, whether the child is the victim or the bully. Keeping communication open and comfortable helps, but so does being actively involved in a kid’s activities. As children and teens increase their online presence, it is natural that typical human behaviors will follow them into the digital world. Cyberbullying Can Kill Ryan Patrick Halligan was a gentle teenager who was struggling through adolescence and was cyberbullied relentlessly until the pain became so unbearable for him that he committed suicide. His sexual orientation was questioned and then in an effort to quell those rumors he took up with a girl. She chatted with him online, but he didn’t know that she later publicized his personal messages and had a laugh at his expense with her friends. When he got to school he was teased and told he was a loser. This particular incident was enough to send him over the edge as he had been bullied previously online and at school. How to help prevent bullying and what to do when it does happen It’s important that we as parents try to remember what it was like to be a teen and how horribly painful it can be when faced with public humiliation. Other things parents can do include keeping the computer in a public safe zone such as the kitchen, family room or living room. If chatting is allowed, make sure you know who your kids are talking to and that they don’t give their personal information out such as password or location to anyone. Sometimes kids give others their passwords as a test of friendship but it’s a bad idea. You never know who that information will be slipped to. Some people have gone so far as to steal another’s account and impersonate them. If this does happen, contact your ISP and support team immediately to report it and get a new account. It’s not a good idea for children to open any email from people they don’t know and setting up an email account with a safe list of people to communicate with is something parents can encourage their children to do. If they do receive an abusive email it is best that they don’t respond to it as this can encourage the bully further. If the abuse continues it should be reported. Some children are nervous about telling anyone because they’re concerned it will make the situation worse. Reassure them that the more people know the better and that it’s not their fault. It’s against the law in many places to harass people. In Canada it is illegal and according to the Criminal Code of Canada it’s a criminal act to communicate repeatedly with someone if it is causing them to fear for their safety. It is also a violation of human rights if someone is spreading hate by insulting someone for their race, religion, sex, sexual orientation or because of a disability. Children who bully need help too. Often they’re being abused at home and acting out towards others to compensate for their own feelings of powerlessness. Children who bully are more likely to skip school and get in trouble with the law when they get older, so it’s important that an adult or teacher tries to reach out to them to find out what kind of home life they could have that is possibly contributing to their delinquent behavior.
Scientists often look to nature for cues when designing robots — some robots mimic human hands while others simulate the actions of octopus arms or inchworms. Now, researchers have designed a new soft robotic gripper that draws inspiration from an unusual source: pole beans. While pole beans and other twining plants use their touch-sensitive shoots to wrap themselves around supports like ropes and rods to grow upward, the UGA team’s robot is designed to firmly but gently grasp objects as small as 1 millimeter in diameter. In a new study, the researchers say their soft robotic spiral gripper offers several advantages over existing robotic devices. Their robot’s twining action only requires a single pneumatic control, which greatly simplifies its operation by eliminating the need for complex coordination between multiple pneumatic controls. Since they use a unique twining motion, the soft robotic gripper works well in confined areas and needs only a small operational space. The UGA device offers another advancement over much existing robotics: an embedded sensor to provide critical real-time feedback. Source: Science Daily
Get Charged! Introduction to Electrical Energy Students are introduced to the idea of electrical energy. They learn about the relationships between charge, voltage, current and resistance. They discover that electrical energy is the form of energy that powers most of their household appliances and toys. In the associated activities, students learn how a circuit works and test materials to see if they conduct electricity. Building upon a general understanding of electrical energy, they design their own potato power experiment. In two literacy activities, students learn about the electrical power grid and blackouts.
An algorithm is a step-by-step procedure for solving a particular problem. When we design an algorithm for a computer to use, we must specify each step very precisely, so that it can be implemented as a computer program. To define an algorithms we usually need to specify: As an example, building on the previous sections, we will define an algorithm for drawing an n-sided polygon of a given size, using turtle graphics. The algorithm has 2 inputs: By radius, we mean the radius of the circle which encloses the polygon. In other words, the distance from the centre of the shape to one of its corners: Clearly there are some constraints on the inputs: In theory, there is no limit to the number or sides, or the radius of the polygon. When you code up the algorithm, you might decided to set maximum values to avoid problems. For example, if you ask for a billion sides you might choose to give an error, otherwise it might take a very long time to draw! These limits aren't really part of the algorithm, they are called implementation details. The output of our algorithm is simply the polygon, drawn by the turtle. Depending of the type of turtle, it might draw on the screen, drag a pen on paper, or just move around on the floor. We must calculate the angle the turtle must turn through at each corner. We have previously worked out that: angle = 360.0/n We must also calculate the length of each side. This is given by (See here): length = 2 * radius * sin(angle/2) We can then draw the shape like this: repeat n times: forward(length) right(angle) Angles in turtle graphics use degrees (1 full turn = 360 degrees). However, in most languages, the sine function expects the angle to be in radians (1 full turn = 2 PI radians). Th easiest solution is to define a second variable, the angle in radians: angle_r = anglePI/180 Here is the example code in Python. It can be easily rewritten in other languages that support turtle graphics: import math import turtle n = 6 radius = 100 angle = 360/n angle_r = anglemath.pi/180 length = 2radiusmath.sin(angle_r/2) for i in range(n): turtle.forward(length) turtle.left(angle) Copyright (c) Axlesoft Ltd 2020
At the beginning of the first millenium CE, the discovery of the monsoon winds and the means to use them created a nautical revolution, allowing for major water crossings toward India and Ceylon. Trading between East Africa and the Persian Gulf intensified in the eighth century, but African relations with Islamic merchants were of a different nature to those of earlier times, since they settled in Africa, boosting urbanization. From the ninth century onward, Muslim geographers Buzurg b. Shahriyâr and al-Mas‘ûdî mention regular trade relations with East Africa, Zanzibar, Pemba and Sofala (Freeman-Grenville 1962: 9-17), while the most famous story of a Persian navigator is of course that of “Sindbâd the Sailor”, who supposedly reached the al-Qumr region, which includes the Comoros Islands and northern Madagascar, between 806-807. These sources indicate that as early as the ninth century, there were major shipping routes between Asia and Africa. The transition between the eleventh and twelfth century was a period of change. A number of urban East African centers developed at this time as did architecture in stone, used for public buildings, mosques and enclosure walls. The Swahili city-states were established: Malindi and Mombasa were mentioned in 1154 by al-Idrîsî who spoke also of the island of Angazidja (Anjouan) and Sufala, the golden country. During the reign of Sulaymân b. al-Hasan, from 1178 to 1195, Kilwa made a fortune from the gold trade from Sofala. For this period, the major chronicles of Swahili city-states are precious tools for the archaeologist, the most famous being the Kilwa Chronicle (Freeman-Grenville 1962: 34-49). A new balance of power developed in the thirteenth century. The Swahili coast was divided into several independent sultanates, including Kilwa, Mombasa, Malindi, Pate and Mogadishu. In 1212-1229, Yâqût noted the cities of Mogadishu, Merka and Malindi, but not until Ibn Battûta’s work of 1331 do we have a precise description of the cities on the eastern coast (Freeman-Grenville 1962: 27-32). Ibn Battûta noted that Mombasa was large, with wooden mosques. Kilwa was supposedly one of the most beautiful towns in the world with stone houses covered with palm-leaf roofs or makuti; only certain mosques and the palace had hard flat roofs. From the fourteenth to fifteenth century, Kilwa continued to hold the monopoly for gold, trading gold from Yufi, situated a one-month walk from the coast. Sofala, a vassal of Kilwa city, maintained commercial relations with the Shona kingdom of Great Zimbabwe; the rise of Great Zimbabwe was intimately linked to the trading of gold with Islamized peoples. Vasco da Gama discovered the route to India and the East African coast in 1498. The European objective was to control eastern trade markets. They possessed two important technological advantages that ensured their domination of the Indian Ocean: the use of firearms and large, fast boats, caravels. The Portuguese built some fifty forts around the Indian Ocean, from Mozambique to Malacca, occupying the coasts of Kenya and Tanzania during the sixteenth and seventeenth century. Despite founding some trading posts, they quickly abandoned any attempt at political hegemony and were content keeping control of the sea routes. At the end of the seventeenth century the area saw significant conflict involving Portuguese and Omani forces. After the fall of Mombasa, the Imam of Oman sent governors and garrisons to large cities such as Pate, Lamu, Mombasa, Zanzibar and Kilwa. In 1828, an Omani garrison was installed at Fort Jesus and the Sultanate of Zanzibar was founded. The Sultanate of Zanzibar required a lot of slaves to maintain its clove plantations, the main export product. Large caravans were organized by the Omanis who destroyed the indigenous populations’ economy and introduced firearms in exchange for slaves and ivory. These slave caravans were funded by wealthy Indian merchants, the banians. But the commercial force of the Sultanate of Zanzibar was also its weakness, its plundering economy being based solely on slavery and the export of tropical products such as ivory and cloves, the limited number of these products increasing the precariousness of the economic system. The direct slave trade brought about important social changes, with Swahilis using landward populations rather than venturing beyond the coastline. For the first time in the history of East Africa, Islam took root in the interior lands of Kenya and Tanzania, right up to the Great Lakes region. In 1876, the movement of slaves toward the coast was strictly prohibited. The prohibition of the slave trade and the development of steam navigation eventually destroyed the supremacy of the Omani fleet. The opening of the Suez Canal imposed one last blow on the Sultanate causing it to lose its primary markets. The last sultan, Sa‘îd Barghash, died in 1888 and Zanzibar became a British protectorate on 1 July 1890. One territory, one population, one religion Wa-swahili, or “shore people”, designates the inhabitants of the East African coastline, and signifies above all a culture with a common language, Kiswahili, and the same religion, Islam. Arab-Persian geographers referred to the inhabitants of the East African coast as the Zanj. The Portuguese also noticed a difference between continental Africans and the people of the coast, who in light of their religion and customs they equated with “Moors” or “Kaffirs”. It was at the beginning of the nineteenth century that the first use of the term “Swahili” appeared, with settlers trying to classify and differentiate the different populations of Africa. The Swahilis have defined themselves as such since the colonial period, but differentiate between themselves according to their region, island or town of origin. Despite some common ground, Swahili identity remains multiple, incorporating populations of diverse background, both Cushitic and Bantu. Swahili culture extends from Mogadishu in Somalia, through Kenya, Tanzania, north Madagascar and Comoros, to the bay of Sofala in Mozambique. As well as religion and language, these coastal populations share the same social organization and architecture. More than 450 Swahili archaeological sites have been registered spread over 3,000 km of the coastline (Pradines 2004: 18-20). The lifestyles on the east coast, Comoros and Madagascar were homogenous due to the dissemination of new ideas and techniques by maritime travellers. Swahili culture reflects neither a specific ethnic group nor a particular nationality. The Swahili civilization stands at the periphery of the Muslim and African worlds, resulting in the development of a unique coastal culture based on trade. In fact, its marginal position is linked to our vision of the Indian Ocean, which separates Africa, Arabia and Asia. But the ocean also provides a connection between these very different cultures: the Swahilis are thus dynamic players, equal to Arab, Persian and Indian traders. Swahili archaeology is at the crossroads of Islamic archaeology and African archaeology.
Bakersfield Night Sky — May 20, 2017 by Nick Strobel The week after commencement BC faculty were working on the next step of creating the Guided Pathways System (college GPS) in a series of intensive all-day work sessions. During that week the Cassini spacecraft zipped through the tiny gap between Saturn’s cloud tops and its rings in its fourth of the Grand Finale Orbits. As it went through the plane of the rings, Cassini beamed a radio signal through the rings, so the Cassini team on Earth could see how the rings changed the radio signal. How the signal was affected will tell us about the sizes of the particles in the rings and how the ring structure changes at different distances from Saturn. Cassini scientists are also using the radio signal to measure the mass of Saturn’s rings from how the gravity of the rings changed the velocity of Cassini. Changes in the velocity of Cassini create shifts in the frequency of the radio signal—more mass means more gravitational force that creates greater changes in the velocity and that results in greater changes in the radio frequency. We measure the changes in radio frequency and work backwards to get the mass. Something similar, by the way, is used by police officers when they use their radar guns to measure the speed of your car. The radar gun bounces a beam of radio waves off your car and the reflected radio waves will have a change in frequency that depends on your speed. Too great a change in the frequency means you get a ticket. If you want to impress your friends at a party, you can tell them that this is an example of the “doppler effect”. (Well, you will either impress them or get another eye roll.) Measuring the mass of the rings will help us figure out the age of the rings. A more massive measurement probably means the rings are old, up to a few billion years of age. If the rings are on the low mass end, then they’re probably just a hundred million years or so old. Figuring out the age of the rings will give us further insights into the individual differences in how the giant planets formed—why is Saturn so impressively endowed with such a gorgeous set of rings and not the other giant planets? Also, the physics of the ring system is very similar to the physics of the disk that formed the planets around our sun 4.6 billion years ago and the proto-planetary disks we see around other stars today. Earthbound Saturn observers will see Saturn as a bright starlike yellow-white object rising at about 10 p.m. among the stars of Ophiuchus. Saturn is also now in the same direction as the bulge of the Milky Way, so the sky background behind Saturn will be significantly brighter. To the right of Saturn, about a hand width with fingers outstretched at arm’s length from your head, will be the dimmer but still bright, red-orange heart of Scorpius, the red supergiant Antares. The star chart below shows the sky at 11 p.m. tonight. Three zodiac constellations west of Saturn is Virgo in which you’ll see the super-bright king of the planets, Jupiter. We’re now exploring that planet up close with the Juno spacecraft. The Juno spacecraft completed its sixth flyby of Jupiter yesterday in an orbit that got it to within about 2700 miles from the cloud tops. To the left of Jupiter in Virgo is the medium-bright star, Spica. Almost directly above Spica is the brightest star north of the celestial equator, Arcturus, in the constellation Bootes. You can also find Arcturus by extending the arc of the handle part of the Big Dipper. Arcturus and Saturn will be about the same brightness with Arcturus the brighter and more orange of the two. Spica is dimmer than Arcturus because Spica is almost seven times further away than Arcturus. Spica actually emits about fifty-six times more energy than Arcturus, or about 12,100 times more energy than the sun. To the left of Bootes is the bowtie shape of Hercules. Binoculars will help you see the fuzzy patch in the upper right part of Hercules, M13. In a telescope, you’ll see that the fuzzy patch resolves into a cluster of hundreds of thousands of stars called a globular cluster. Later this week, in the early morning of May 22, you will see the thin waning crescent moon pass by Venus low in the east in the pre-dawn sky. The moon will be at new moon phase on May 25, so look for a beautiful waxing crescent moon low in the west shortly after sunset the evenings of May 26 to 28. Want to see more of the stars at night and save energy? Shield your lights so that the light only goes down toward the ground. See www.darksky.org for how. Director of the William M Thomas Planetarium at Bakersfield College Author of the award-winning website www.astronomynotes.com
Ulcers are skin wounds that are slow to heal. In the foot, as prominent metatarsal heads on the plantar (bottom of the foot)are subjected to increased pressure, the skin begins to become callused. When subjected to shearing forces, there is a separation between the layers on this callused skin, which fills with fluid and becomes contaminated and infected. The result is a foot ulcer. Diabetics are especially prone to ulcers because of there lack of sensation and the inability to feel the pain involved with the beginnings of an ulceration. Ulcers are classified in four stages, according to how deeply they penetrate the layers of skin they have broken through. The four stages of ulcers are: -Stage 1 -- Characterized by reddening wounds over bony areas. The redness on the skin does not go away when pressure is relieved. -Stage 2 -- Characterized by blisters, peeling, or cracked skin. There is a partial thickness skin loss involving the top two layers of the skin. -Stage3 -- Characterized by broken skin and sometimes bloody drainage. There is a full thickness skin loss involving subcutaneous tissue (the tissue between the skin and the muscle.) -Stage 4 -- Characterized by breaks in the skin involving skin, muscle, tendon, and bone and are often associated with a bone infection (osteomyelitis). The are also four major cause of foot ulcers: -Neuropathic -- Related to the nerves and characterized by a loss of sensation in the feet. -Arterial -- Related to poor blood circulation to the lower extremity. This type of ulcer can be very painful and is usually found on the tips of toes, lower legs, ankle, heel, and top of the foot. It can very easily become infected. -Venous -- Related to compromised veins. These ulcers are often seen around the inside of the ankle and are slow to heal. -Decubitus -- Derived from excessive and prolonged pressure on one area of the foot. The most common type of decubitus ulcer of the feet is bed sores on the backs of the heels of people confined to bed for long periods of time. Foot ulcers are a common problem for diabetics. Contact casts are sometimes applied to the diabetic foot to relieve the bony prominent areas of pressure, allowing ulcers to heal.
T-TEST in Excel TTEST function is categorized as a Statistical function in Excel. In mathematical terms, the TTEST function in excel will calculate the probability that is associated with a Student’s T-Test. This function is usually used to test the probability of two samples that have underlying populations with the same mean. T-TEST Formula in Excel Below is the T-Test Formula in Excel Details of Parameters: T-TEST in excel has the following required parameters, i.e., array1, array2, tails, and type. - array1: it is the first data set. - array2: it is the second data set. - Tails: Tails specifies the number of distribution tails. If tails = 1, T-TEST uses the one-tailed distribution. If tails = 2, TTEST uses the two-tailed distribution. - Type: Type is the kind of t-testT-testA T-test is a method to identify whether the means of two groups differ from one another significantly. It is an inferential statistics approach that facilitates the hypothesis testing. to perform. - Two-sample equal variance (homoscedastic) - Two-sample unequal variance (heteroscedastic) How to Use the TTEST Function in Excel? The T-Test in excel is very simple and easy to use. Let us understand the working of the TTEST function in excel by some examples. TTEST function can be used as a worksheet function and as a VBA function. TTEST function as a worksheet function. The T-Test in Excel Example #1 Suppose have given the following expenses data spent in India and in the US. The probability associated with the Student’s paired t-test with a 1-tailed distribution for the two arrays of data below can be calculated using the Excel function. The T-Test formula in excel used is as follows: =TTEST(A4:A24,B4:B24,1,1) The output will be 0.177639611. T-TEST in Excel Example #2 A marketing research firm tests the effectiveness of a new flavoring for a leading beverage using a sample of 21 people, half of whom taste the beverage with the old flavoring and the other half who taste the beverage with the new flavoring. Two-sample equal variance (homoscedastic) is calculated by the following T-Test formula in Excel =TTEST(A31:A51,B31:B51,1,2) The output will be 0.454691996. T-TEST in Excel Example #3 To investigate the effect of a new fever drug on driving skills, a researcher studies 21 individuals with fever. All participants then entered a simulator and were given a driving test, which assigned a score to each driver, as summarized in the below table. Two-sample unequal variance (heteroscedastic) can be calculated by Excel TTest function by replacing the type to 3 =TTEST(A57:A77,B57:B77,1,3) The output will be 0.364848284. T-TEST in Excel can be used as a VBA function. Suppose we have the data sets located in the excel sheet range from A4 to A24 and B4 to B24, then we can calculate the TTEST of the given datasets by using the below VBA functions. Sub TTESTcal() // start the TTEST function scope Dim TTEST as interger TTEST = Application.WorksheetFunction.TTest(Range(“A4:A24”),Range(“B4:B24”),1,1) MsgBox TTEST // print the TTEST value in the message box. End sub // End the TTEST function Things to Remember about the TTEST Function in Excel - TTest function through the #N/A Error if the two supplied arrays have different lengths. - The tails and type parameters are truncated to integers. - The T-Test in excel returns #ValueT-Test In Excel Returns #Value#VALUE! Error in Excel represents that the reference cell the user has either entered an incorrect formula or used a wrong data type (mostly numerical data). Sometimes, it is difficult to identify the kind of mistake behind this error.! Error if either the provided tails parameter or the provided type parameter is non-numeric. - The T-Test in excel returns #NUM! Error if- - The supplied tails parameter has any value other than 1 or 2. - The supplied type parameter is not equal to 1, 2, or 3. T-TEST in Excel Video This has been a guide to TTEST Function in Excel. Here we discuss the T-TEST Formula in excel and how to use TTEST function along with excel example and downloadable excel templates. You may also look at these useful functions in excel –
Genetic mutations are alterations in DNA that may result in the development of a disease later in life. A BRCA gene is a tumour suppressor gene that helps to prevent the development of some cancers, particularly breast cancer. If a mutation occurs, this gene no longer functions at preventing these cancers. Genetic screening is when a population is tested for a mutation in an attempt to identify a group of people that are positive for the mutation. This can help identify cancer in different populations as well as track their inheritance. This study was conducted online, questioning the Irish populations opinions on how a genetic mutation would alter their life. Topics covered included having children, illness prevention therapies if a mutation were discovered, and what impact would a mutation have on their life. Comparisons were made between genders, and age groups to demonstrate if differences of opinions exist between each group selected was compared with the overall attitude of the population. It was discovered that there was an overall difference of opinion between the different age groups, but in some questions like the ones regarding children, the opinions were similar. In this study, an investigation was conducted regarding the Irish population’s attitudes and existing knowledge towards genetic screening and how testing positive for a genetic mutation, specifically in either the BRCA1 or BRCA2 gene, would influence lifestyle choices. McCarthy, Emer; Fleming, Ada; and Cronin, Dawn Hannah "An Investigation on the Irish Population’s Attitudes and Knowledge Towards Genetic Screening for Cancer," International Undergraduate Journal of Health Sciences: Vol. 1 , Article 8. Available at: https://sword.cit.ie/iujhs/vol1/iss1/8
Play is not only about having fun or to keep kids distracted, it is a crucial part of a child’s development. Children are building all kinds of skills during playtime. Giving them access to a variety of construction toys and creative products helps them build self-confidence and fosters independent learning. Fine and gross motor skills are developed, eye-hand coordination is honed, and by overcoming challenges they become adept problem solvers. Giving children time to explore and play with others helps them develop into more confident human beings. For well-rounded development of a child, it is important they play with a variety of things. Natural materials, like sand and water, challenge different senses than do manufactured toys, like wooden blocks and construction materials. For example, playing in the sand involves scooping, patting and wriggling. Whereas playing with construction toys requires grasping, snapping, clicking and stacking, which fine-tunes eye-hand coordination. Children will normally compare pieces before trying to connect or stack them, which will teach them depth perception and practice recognizing “same and different.” Older children must use math to count the pieces they will need, and reading skills when instructions are included to build more elaborate designs. Children with a learning disability especially benefit from the development of these skills. But toys only do half the job. Another crucial role of playing is the opportunity for children to explore friendships. Studies have shown that children who have friends tend to be more socially competent and altruistic, and have higher self-esteem and self-confidence. Friendships enable children to learn more about themselves and develop their own identity. This begins paying off during their tumultuous teens, as friends are able to help them reduce stress and navigate challenging experiences. Construction toys are perfect for sharing, making it easier to have a playmate nearby. Building together fosters teamwork and cooperation. Kids learn to take each other’s advice and take turns. Parents can also join in. While constructing objects, parents can ask their children how they made it, what components they needed to use, or ask for instructions on how to make another one. Not only does this encourage social skills, but it helps children give and understand directions and practice verbalization.
The 10 Big Ideas provide a purpose for the aspects, skills, knowledge, and contexts chosen to form the substance of the curriculum. These big ideas form a series of multi-dimensional interconnected threads across the curriculum, allowing children to encounter and revisit their learning through a variety of subject lenses. Over time, these encounters help children to build conceptual frameworks that enable a better understanding of increasingly sophisticated information and ideas. Our Ten Big Ideas Invites children to find out what it means to be human. Invites children to find out about the diverse natural environments of the world and the plethora of species, both plant and animal, that live in them. They explore the characteristics and features of a range of habitats and study how living things interact with them. Invites children to find out about the diverse and dynamic physical processes that are present in, and have a significant impact on, places, the environment, and the world around them. Invites children to explore the visual, cultural, social, and environmental aspects of homes in their locality and the fuller world. Invites children to discover the place of everyday and exceptional creativity, including the qualities of persistence, determination, originality, and resilience that form the basis of the creative process. Invites children to compare ways that things are the same or different. They identify simple and more complex patterns and make connections. Invites children to be curious and search for answers in response to original, familiar and more complex questions. Invites children to explore the importance of significant people, places, events and inventions. They examine why things are meaningful to some and not to others, based on their values, beliefs and experiences. Invites children to explore the properties of all matter, including that which is living and non-living. It explores how elements are both formed and change. Invites children to find out about the causes and consequences of change and evolution.
Plaque is the sticky film of food and bacteria that forms on the teeth and produces acids, which dissolve the tooth enamel. Brushing with fluoride toothpaste can help to remove plaque before it has time to harden and become tartar. Tartar build-up can cause serious dental health problems, which may ultimately result in tooth loss. Once tartar is formed, only a trip to the dentist can remove it. Gingivitis, a mild inflammation of the gums, is the earliest stage of gum disease. Plaque and tartar build up at the gum line, causing your gums to get red and puffy. You may also notice some bleeding during brushing and flossing. Periodontal disease, also called gum disease, is an inflammation and infection of the gums and bone that surround and support your teeth. It is caused by bacteria in plaque, a sticky, colourless film that constantly forms on your teeth. Gum disease is the major cause of tooth loss among adults. Good oral hygiene is essential to alleviate bad breath. Brush thoroughly twice a day with GLISTER Multi-Action Fluoride Toothpaste and GLISTER Toothbrush, which helps remove plaque and food particles. Use GLISTER Mint Refresher Spray to freshen your breath and prevent bad breath.
The following information, adapted from The MLA Handout for Writers of Research Papers edition, demonstrates many of the more common examples of how to cite your sources using MLA style. For additional information, consult the MLA Handout at the reference desks located throughout the Texas A&M University libraries. When you omit the author’s name in the sentence: Ex. One researcher discovered a direct relationship between the frequency of laughter and the level of anxiety in teaching scenarios (Elizondo 2). When you mention the author’s name in your sentence: Ex. Elizondo states that “Responding to humor that the client has placed in their document shows that you are indeed a person” (154). When you cite more than one work by the same author: Ex. The author initially proposed making jokes within the learning environment to foster a productive atmosphere. (Elizondo, Laughing and Learning 24). However, he eventually settles on a more indirect approach, focusing on observational mirth instead of forced humor (Elizondo, “My Humorous Hubris” 2). When the work has three or more authors: Ex. Researchers hold that humor can effectively be used to reduce power distances in writing consulting scenarios (Elizondo et al. 9). Citations in the “Works Cited” List The Modern Language Association (MLA) has dropped the use of specific citations for different sources due to the combination of sources so common in modern publications, like a song listened to online, taken from a record album released decades ago. MLA has, instead, created a list of core elements that should be identified and placed in order in a citation. Entries on your “Works Cited” page should be organized alphabetically by author. If no author is available for a source, alphabetize by the title of the source. - Title of source - Title of container - Other contributors - Publication Date : Begin the citation with the name of the author, if available. When creating your entry, list the authors in the order they appear in the source material. The first author should be written Last name, First name . If you are citing a source with two authors, cite the first author as described, followed by “and” and the second author’s name with the first name first, followed by the last name. If you are citing three or more authors, cite the first author as described, followed by “et al.,” the Latin abbreviation meaning “and others.” Exs. Dryden, Tyler. Seully, Greg and Benjamin Wasikowski. Reed, Arturo et al. 2. Title of source : Cite titles exactly as they are given in the source. If the source is part of a larger work (ex. an article within a journal, a short story in an anthology), put the title in quotation marks. If a source is self-contained or independent (ex. a book or film), italicize the title. This part of the citation will be followed by a period. Ex: Wuthering Heights. “A Short History of the Microwave.” Saving Private Ryan. 3. Title of container : If the documented source is a part of something larger (ex. a television series, an academic journal), that larger unit is referred to as the container. For example, if your source is an article, the container would be the journal in which it appeared. Containers are italicized and followed by a comma. Exs. Microwave Monthly, The Great Anthology of Short Stories, Game of Thrones, 4. Other contributors : “Other contributors” includes people that had a hand in the final product but are not the original creator, such as editors or translators. Cite these contributors with an unabbreviated description of their action (ex. edited by, translated by). This part of the citation, if applicable, will be followed by a comma. Exs. edited by Tom Lane, translated by Hunter Pierce, performed by George Clooney, : Sources are commonly released in multiple forms (ex. reprinted versions of textbooks, extended cuts of films). This part of the citation, if applicable, will be followed by a comma. Exs: 7th ed., extended director’s cut, unabridged version, : Do not confuse Version . When a source is part of a numbered sequence, like a journal, cite the number. If the source is numbered in a two-tier system (ex. volumes and issues, seasons and episodes), differentiate between the two by type. This part of the citation, if applicable, will be followed by a comma. Exs. vol. 5, no. 9, season 8, episode 1, no. 147, : This part of the citation refers to the agent responsible for making the source publicly available (ex. a research agency, university press, film studio). Publishers for websites are often found at the bottom of the page with the copyright information. This part of the citation, if applicable, will be followed by a comma. Exs. Texas A&M UP, Twentieth Century Fox, Museum of Fine Arts, Houston, 8. Publication date : Sources can sometimes appear in different media on different dates. Choose the date most relevant to your work. Periodicals are sometimes dated with a season, rather than a specific date. Include this information along with the year. This part of the citation, if applicable, will be followed by a comma. Exs. 28 Dec. 2011, 1999, Spring 2002, : The source’s location is dependent on how the source was published. Locations in print sources are indicated with page numbers. The location for a website is often its URL. Publishers sometimes use digital object identifiers (DOI) as locators for online publications. When available, use DOIs instead of URLs, as DOIs do not change. This will be the last item in the citation and should be followed by a period. Note: Keep in mind that not every element will appear in every citation. Regardless of which element appears last, MLA citations should always end with a period.
Introduction: Intro to Perspective and Construction Drawing Here are the basics to learning perspective and construction drawing, from simply drawing line to one and two point perspective. With these 8 steps you can learn the core skills to apply to construction drawing, design, and other types of formal drawing. Step 1: Line Exercises Starting by learning basic straight line technique will help you with the more complex skills. - Make 2 points and draw a straight line in between the two - Lock wrist and use arm to achieve straight line motion - Not too slow (line may be rough), but also not rushed (the line might be inaccurate, go past the second dot) Once you have repeated the lines enough that you feel that you have mastered them, making sure they are straight and consistent, you can move on to curves. Step 2: Curves Curves are similar to lines but utilize the curve of your wrist that you want to try and avoid when drawing lines. - Lock your arm in place and use the natural curve of the wrist to draw a curved line between two points. - Draw over the same line 8 times Repeat enough times that the curves are consistent. Try curves of different sizes. Still utilizing your curve, you can move on to ellipses. Step 3: Ellipses Ellipses are even circles or ovals. There are two methods of drawing ellipses, the latter will get you more exact shapes. - For small ellipses, ghost by moving arm (for large ellipses)/wrist (for small ellipses) while in motion, lower the pencil down on to the paper. This will get you used to the motion of the ellipse before you put your pencil to the paper, and it will make it more precise. - Draw box using straight lines. - Draw ellipses inside of the box, starting a new ellipse at the midpoint of each previous circle, to make even shapes. Those are the basics to learning 2D renderings. Now you can use these skills to create 3D shapes and perspective. Step 4: Learning Isometric Shapes There are two basic types of 3D angles/shapes, Isometric and Oblique. Isometric shapes are made up of straight lines facing the same direction do not converge to a single point, but remain parallel no matter what direction they are facing. Isometric shapes refer to a non-frontal facing view on an object, or at a corner. Step 5: Learning Oblique Shapes An oblique drawing starts with a straight on view of one of the object's faces, which is often the front face. Angled, parallel lines are drawn to represent the object’s depth. Straight lines facing the same direction do not converge to a single point, but remain parallel no matter what direction they are facing. Step 6: 1 Point Perspective Perspective!!! Perspective drawing will really allow you to accurately represent 3D objects on a 2D picture plane, and is a perfect culminations of the skills you have learned so far. There are 3 types of perspective drawing, 1 point, 2 point, and 3 point (which we will not cover, as it is less relevant, far more difficult, and comes up less often). You can implement perspective in anything from architectural work to object design. 1 point perspective is similar to oblique where one plane remains flat and facing the viewer, side planes and vertical planes converge to a single point on the horizon line. All vertical lines are parallel. - Start by drawing a horizontal horizon line and one “vanishing point” somewhere on the line. - The vanishing point is the point on the horizon line at which all of our lines will go to. - Draw the vertical lines, they have nothing to do with the vanishing point and will be completely vertical. - Then draw the horizontal lines completely horizontal with planes/sides of a shape that run parallel with the horizon line. - The remaining sides will run towards the vanishing point. - This means that if you extended your line it should run straight through the vanishing point. - Do this on all lines in planes that do not run parallel to the horizon line, and are not vertical. Once you are able to master this with a variety of different shapes (moving on from simple cubes), try 2 point perspective. Step 7: 2 Point Perspective 2 point perspective is similar to one point perspective, but instead there are 2 points of conversion on the horizon line. Typically, 2 point perspective is used to describe an object where the corner is visible, that clearly heads towards two separate vanishing points. Just like in 1 point perspective, all verticals will still remain parallel. - Start by drawing the horizon line. - Draw the corner of the box using a vertical line that is closest to the viewer. - Draw light lines that converge to each of the vanishing points on the horizon line. - Next, draw the receding corners of the box using shorter, vertical lines. - Lastly, darken the outline of the box created to separate the object from the space around it. Okay! Hopefully you've mastered these skills and can move forward to shading, to bring realism to your drawings and make them more impressive and interesting. Step 8: Basic Shading After learning all of these techniques, you can incorporate shading into your drawings to heighten them even further. Shading is a pretty easy concept to understand. Shading comes in when determining where light and shadow are in your drawing. - Planes directly facing the light source will receive the most amount of light, therefore being the brightest areas on an object. - Mid-tones indirectly face the light, and will appear less bright than planes directly facing or directly opposing the light. - Dark Tones receive little to no light, and are always darker than planes facing the light source. - Cast shadows help to “ground” an object and to establish a sense of space. Here, we are using a hatching and crosshatching technique, which is made up of individual lines that get closer and darker in the darker areas and lighter and more spread out in the lighter areas. You may also simply shade completely, just varying the tone or weight of your utensil. Hopefully this tutorial has been helpful! You can implement these skills with a variety of different drawing styles and subjects, and use these basics to further explore drafting.
The galaxy Messier 101 is a swirling spiral of stars, gas, and dust. Messier 101 is nearly twice as wide as our Milky Way Galaxy. Spitzer's view [left frame], taken in infrared light, reveals the galaxy's delicate dust lanes as yellow-green filaments. Such dense dust clouds are where new stars can form. In this image, dust warmed by the light of hot, young stars glows red. The rest of the galaxy's hundreds of billions of stars are less prominent and form a blue haze. Astronomers can use infrared light to examine the dust clouds where stars are born. Messier 101 has a pancake-like shape that we view face-on. This perspective shows off the spiral structure that gives it the nickname the Pinwheel Galaxy. In this Hubble image [middle frame], taken in visible light, the bright blue clumps are regions where new stars have formed. The yellowish core consists mainly of old stars. The dark brown dust lanes are colder and denser regions where interstellar clouds may collapse to form new stars. All of these features are shaped into a beautiful spiral pattern by a combination of gravity and rotation. Astronomers use visible light to study where and how stars form in spiral galaxies. Chandra's image of Messier 101 [right frame], taken in X-ray light, shows the high- energy features of this spiral galaxy. X-rays are generally created in violent and/or high- temperature events. The white dots are X-ray sources that include the remains of exploded stars as well as material colliding at extreme speeds around black holes. The pink and blue colors are emission from million-degree gas and from clusters of massive stars. The pink emission indicates lower-energy X-rays and the blue higher-energy X- rays. One reason astronomers study Messier 101's X-rays is to better understand how black holes grow in spiral galaxies. The International Year of Astronomy Great Observatories Image Unveiling is supported by the NASA Science Mission Directorate Astrophysics Division. The project is a collaboration between the Space Telescope Science Institute, the Spitzer Science Center, and the Chandra X-ray Center. Object Names: M101, NGC 4547, The Pinwheel Galaxy Image Type: Astronomical/Annotated Credit for Chandra Image: NASA, CXC, and K. Kuntz (JHU) To access available information and downloadable versions of images in this news release, click on any of the images below:
Before any eye surgery such as custom LASIK vision correction is considered, basic education about the eye tends to be helpful for our patients. Here is a quick primer on your eyes and how they work. The Process of Sight All vision is based on light. In order for you to see correctly, light must pass through various parts of your eye for your brain to interpret what you are seeing and produce an image of the object you are looking at. To see clearly, the cornea (the front of your eye) must be perfectly round. When light passes into the cornea, it passes through the iris, the pupil, and finally, the crystalline lens, located inside of the eye. Depending on the amount of light, the pupil and the iris muscles adjust to allow the proper amount of light in. After passing through the iris and the pupil, the crystalline lens focuses the light onto the retina. The retina senses different types of light and allows the optic nerve to send the information to the brain. For proper eyesight, the cornea (the clear window in front of the eye) and the lens (behind the pupil) must properly focus or”refract” light onto the retina (at the back of the eye). If the length or shape of the eye is not ideal, the light may get focused too early (in front of the retina) or too late (behind the retina) leaving a blurred image on the eye is a very complex organ that must work precisely in order to produce correct vision. When there are problems with the shape of the cornea, the focusing ability of the crystalline lens, or with the retina, your vision can become jeopardized. Myopia (near-sightedness), hyperopia (far-sightedness), and astigmatism (distorted vision) are what are known as refractive errors. These types of errors can be corrected with corrective lenses such as contact lenses or glasses and can often be permanently corrected with LASIK.
New finding could help circuits keep shrinking In 1959 physicist Richard Feynman issued a famed address at a meeting of the American Physical Society, a talk entitled “There’s Plenty of Room at the Bottom.” It was an invitation to push the boundaries of the miniature, a nanotech call to arms that many physicists heeded to great effect. But more than 50 years since his challenge (pdf), researchers have begun to run up against a few hurdles that could slow the progression toward ever-tinier devices. Someday soon those hurdles could threaten Moore’s Law, which describes the semiconductor industry’s steady, decades-long progression toward smaller, faster, cheaper circuits. One issue is that as wires shrink to just nanometers in diameter, their resistivity tends to grow, curbing their usefulness as current carriers. Now a team of researchers has shown that it is possible to fabricate low-resistivity nanowires at the smallest scales imaginable by stringing together individual atoms in silicon. The group, from the University of New South Wales (U.N.S.W.) and the University of Melbourne in Australia, and from Purdue University in Indiana, constructed their wires from chains of phosphorus atoms. The wires, described in the January 6 issue of Science, were as small as four atoms (about 1.5 nanometers) wide and a single atom tall. Each wire was prepared by lithographically writing lines onto a silicon sample with microscopy techniques and then depositing phosphorus along that line. By packing the phosphorus atoms close together and encasing the nanowires in silicon, the researchers were able to scale down without sacrificing conductivity, at least at low temperatures. “What people typically find is that below about 10 nanometers the resistivity increases exponentially in these [silicon] wires,” says Michelle Simmons, a U.N.S.W. physicist and a study co-author. But that appears not to be a problem with the new wires. “As we change the width of the wire, the resistivity remains the same,” she says. Phosphorus is often introduced into silicon because each phosphorus atom donates an electron to the silicon crystal, which promotes electrical conduction or even can serve as bits in quantum computation schemes. But those conduction electrons can easily be pulled away from duty, especially in tiny wires where the wire’s exposed surface is large compared with its volume. By encasing the nanowires entirely in silicon, Simmons and her colleagues made the conduction electrons more immune to outside influence. “That moves the wires away from the surfaces and away from other interfaces,” Simmons says. “That allows the electron to stay conducting and not get caught up in other interfaces.” Demonstrating electric transport in a wire so small “is quite an accomplishment,” says Volker Schmidt, a researcher at the Max Planck Institute of Microstructure Physics in Halle, Germany. “And being able to fabricate metallic wires of such dimensions, by this theoretically microelectronics-compatible approach, could be a potentially interesting route for silicon-based electronics.” The wires, the researchers say, have the carrying capacity of copper, indicating that the technique might help microchips continue their steady shrinkage over time. Bookmark this page for “Moores Law” and check back regularly as these articles update on a frequent basis. The view is set to “news”. Try clicking on “video” and “2” for more articles.
The History Department aims to ensure that students develop a passion for, and critical understanding of the past, and are able to use this to form educated opinions regarding the present. At Key Stage 3, students study a range of topics including the Roman Empire, Medieval and Tudor England, Black Peoples of the Americas c.1600-2009, Industrial Britain and the Twentieth Century World. At GCSE, students study Elizabethan England, Weimar and Nazi Germany, Superpower Relations and the Cold War and Crime and Punishment through Time. The A-Level course focuses on Revolution and Settlement in Early Modern Britain, 1625-1701, Russian Revolutions 1894-1924 and Civil Rights and Race Relations in the USA, 1850-2009. Recently, History students have been involved in an intergenerational project with the Maidenhead Heritage Centre, and have visited Auschwitz as part of the Holocaust Education Trust’s work on developing understanding through schools. GCSE Textbooks and Revision Guides If parents wish to purchase books to help with their child's studying, here is a recommended list: Edexcel 9-1. Pearson books for textbook (Early Elizabethan England, Weimar and Nazi Germany, Superpower Relations and the Cold War). Hodder textbook for Crime and Punishment through time. Purple Edexcel 9-1 revision guides are recommended for revision.
Male songbirds use a versatile part of the brain to learn their father’s song during the early stages of development, according to a report published yesterday in the online version of Nature. Researchers at the University of California at San Francisco (UCSF) found that Bengalese finch males use a trial-and-error method in learning the song they will use to attract a mate once they reach maturity. The learning process begins around 40 days after hatching and ends about 90 days into development. During their research, the neuroscientists focused primarily on the basal ganglia, a cluster of the brain known to be responsible for action selection, cognitive functions, and motor systems in birds and other animals. The brain structure is located at the base of the forebrain in humans and has been found to play a central role in neurological disorders including Parkinson’s disease, obsessive-compulsive disorder, and Tourette’s syndrome. One neurological model posits that the basal ganglia reinforces a behavioral pattern by transmitting a rewarding dopamine signal after receiving feedback on the result of the movement from the motor cortex. “It’s the first place where the brain is putting two and two together,” said UCSF’s Jonathan Charlesworth, the first author of the report. “If you remove the basal ganglia in a bird that hasn’t yet learned to sing, it will never learn to do so.” Through previous research in the UCSF lab, neurologists were about to determine that adult finches can track the different notes in the song that that they play or hear and can modify them individually. The foundational experiments conducted in the lab of Michael Brainard, an associate professor of physiology at UCSF, showed that the adult finches could be trained to change notes in their song by emitting a harsh noise when a finch hit a particular note. After a few hours of hearing these timed sonic disruptions, the finch would alter the pitch of the note associated with that noise. In the latest experiment, researchers sought to block signals sent from the basal ganglia to see if it would affect the finch’s ability to learn how to modify its song. They discovered that as long as the bird’s anterior forebrain pathway – a bundle of nerves between the basal ganglia and the motor cortex – was blocked, the birds could not change their song in accordance with the previous experiment’s negative stimulus. The team then removed the block and found the finches were able to change the pitch of their song with no additional practice. It was as if they finches knew they wanted to change the particular note in their song, but couldn’t physically do it. “This study represents an important step in identifying brain mechanisms that mediate trial-and-error behavioral learning,” Richard Mooney, a neurobiologist at Duke University, told Nature News. “It suggests that the basal ganglia can learn how to improve behavior even when they are prevented from changing it. This stands in contrast to the popular idea that the basal ganglia must actively drive variability for trial-and-error learning to occur.” Brainard expects this research to be extremely relevant to the efforts to treat and cure neurological disorders like Huntington’s or Parkinson’s disease.
A Virtual Private Network or VPN, is a connection method used to add security and privacy to private and public networks. VPNs add privacy and security to networks by masking a users internet protocol (IP) address so their online actions are virtually untraceable. VPNs work by creating a data tunnel between a user’s local network and an exit node in another location, giving the illusion that a user is in another location then where they actually are. VPNs use encryption to scramble data when it’s sent over a Wi-Fi network. By encrypting the data, it makes it unreadable. VPN hides a users: - Your browsing history - Your IP address and location - Your location for streaming - Your devices - Your web activity — to maintain internet freedom In Data Defined, we help make the complex world of data more accessible by explaining some of the most complex aspects of the field. Click Here for more Data Defined.
Essential Question: How can I use context clues to figure out the meaning of unknown words? CONTEXT CLUES Writers often include other words or phrases to help with the understanding of a vocabulary word. These words or phrases are referred to as context clues. They are built into the sentences around the difficult word. You can make logical guesses about the meanings of many words by using the clue words. Types of Context Clues 1. Examples 2. Synonyms and definitions 3. Antonyms and contrasts 4. Experience or sense of the sentence What are example clues? Using examples, an author tries to show what a word means. A writer may give just one example or several. Remember that these examples are not synonyms. Look for words or phrases like "such as," "including," or "consists of." Colons : and dashes - can also signal examples. Here are some example clues: The river was full of noxious materials such as cleaning agents from factories and pesticides from the nearby farms. This third grade was full of precocious children. One child had learned to read at two and another could do algebra at age 6. When going to an office party you should show your best decorum, for example, dress your best, drink and eat moderately, and be sure to thank the host before you leave. The words highlighted in yellow are examples of the word that you need to define. A definition or synonym clue is a clue that means the same as the vocabulary word. The initial, or first, class explained how to write a sentence, and they made it easy to learn. (We learn from the words around initial that the definition is first. The comma is a signal that a definition or example might follow.) An antonym or opposite clue means the opposite of the vocabulary word. Janice, who was incapable of lying, had to tell Tanya the truth about her purse. Does incapable mean A. Truth B. Unable C. Noticed D. Delivered incapable = A. unable incapable of lying had to tell the truth These are opposite, so we know she couldnt lie and had to tell the truth. Tips for understanding a new word: When choosing the definition of a word, try to insert a word you know that makes sense with the other words and see if it is on the list of choices. More Tips Read the sentences around the word. Dont just skip to the underlined word and try to figure it out. Sometimes meanings are hidden in the other sentences. People who skip over words they dont understand can lose more than just one word; they can lose the entire meaning of a sentence or more. 1.The joey, which is a baby kangaroo, peeked out of his mother's pocket. (definition) 2. The beach was covered with debris like paper and cans, and the children picked up all the trash. (synonym) 3. The ancient dress looked like new after she washed it. (antonym) 4. These were the words that pinwheeled through Despereauxs mind as his body descended into the darkness. Experience or sense of the sentence Fluorescence is an emission of light due to an optical transition between states of the same spin multiplicities (e.g., singlet to singlet). Since this is an allowed transition, it is intense and fast. Interview Skills & Resume Writing Workshop ... stay involved and interested Maintain enthusiasm throughout the interview Be professional Ask your questions at the end of the interview At end of interview be sure to clarify next steps, but don't put... No theory gets it all correct but each theory contributes to a more complete and accurate view of how international relations work. Three levels of causes of war(and other things in IR - Nye metaphor) Deep (or ultimate) causes: "logs... Do Birds of Feather Flock Together? Arianne Jennings Why did I chose to research this topic????? Clore and Byrne (1974) Emotion is the basic determinant of attraction Blass & Schwarcz (1982) Tor & Singh (2007) Does Similar attitudes cause an... Coordination complexes [CoCl2(en)2]Cl dichloro bis(en) cobalt(III) chloride Cl Cl N N N N N N trans-same Co Co N N N N N N N N Cl Cl N N Cl Cl Cl Cl cis-Co Co enantiomers Coordination complexes Na[FeCl4]... They found the issue - incorrect implementation of ETSI code in XYZ's custom script on NAS decoding. Benefits. The issues once resolved ensured that ABCbecame more competitive and hence got the new business in the area of Conformance Toolset worth... Use cranes, hoists, lift tables, and other lift-assist devices whenever you can. Test the weight of an object before lifting by slightly pushing with hand or foot. Get help if it's too heavy for you to lift by yourself. PPT-024-04.... Ready to download the document? Go ahead and hit continue!
Macrosegregation is the uneven distribution of alloying elements within a solidified aluminum part, creating, for example, copper-poor regions. This is most likely to occur in the center of a casting, where it remains hidden until the casting is reprocessed for another use such as rolling a thick slab into a flat sheet. These unbalanced structures can form on a scale from several fractions of an inch to several yards and they can lead to cracking, shearing, or other mechanical failure of the material. This issue is thought to be particularly significant as industry moves toward faster production schedules and larger sheet metal runs—for example, parts for pickup trucks and airplane wings. Greater emphasis on aluminum recycling also poses issues where the composition of secondary elements may be unpredictable. “Analyzing the structure, and in particular the presence of solid grains, formed as the aluminum alloy turns from liquid to solid is difficult because you cannot see through aluminum, the material is rapidly cooled from 700ºC, and differently sized grains are moving as the aluminum solidifies at the rate of about 2 to 3 in/min,” said Antoine Allanore, Assistant Professor of Metallurgy at MIT. The problem is typically a lack of the alloying element near the center of the solidifying slab or ingot. “It’s a very perverse situation in the sense that from the outside the solid slab could look very nice, ready to go to the next treatment, and it’s only later on that you discover that there was this defect in a section, or in an area, which basically means a huge loss of productivity for the entire supply chain,” said Allanore. Over the past three years, Allanore and his student, Samuel R. Wagstaff, were able to pinpoint a single number—the “macrosegregation index”—that quantifies the difference between the ideal chemical makeup and the actual chemical makeup at specific points in the solidification process. “In our experiments, we did some specific tests at full scale to quench, so to basically sample the molten metal as it’s cast, and we’ve seen grains anywhere between 10 microns up to 50 microns, and those grains are, according to our development, the ones responsible for macrosegregation,” said Allanore. Their solution is inserting a jet stream to recirculate the hot liquid so those grains get redistributed uniformly as opposed to accumulating in one region of the ingot. “It’s like a hose of water in a swimming pool,” he said. “From a purely fluid mechanics perspective, the mixture is homogeneous. It’s just a full, complete mixture of the alloying elements and aluminum.” “The introduction of the jet induced a completely different recirculation of the grains and therefore you get different microstructure, all along the section. It’s not just on the edges or not just in the center, it’s really across the entire section,” Allanore said. The researchers were able to calculate the optimal jet power needed for the most common aluminum alloys, and then tested their predictions. Centering on metal work Wagstaff finished his doctorate at MIT in September after three years and now works for Novelis in Sierre, Switzerland. A multi-generational, and successful, interest in metals led him to first working for Novelis at age 14. After he earned his bachelor’s degree in mechanical and aerospace engineering at Cornell University, Novelis offered Wagstaff the opportunity to pursue a PhD to help the company solve the problem of macrosegregation by developing a method to stir aluminum. “The problem with aircraft-grade or aerospace-grade plate is you have very significant macrosegregation regions in the center of that plate, so you have drastic drops in mechanical properties in the very center,” said Wagstaff. “Our research started with the idea we want to be able to stop macrosegregation.” “We knew we could figure out how to mix things up and we could stir things around, but being able to compare A to B to C would have been really difficult, and so that’s where the macrosegregation index came from. That’s just a numerical scheme that we invented to compare type A mixing to type B mixing to type C mixing, so then we can somehow relate all of the different mixing parameters together to say this kind of mixing is better,” he said. The solution was to design a jet that would work with existing direct-chill casting machines. “All we did was change the jet power as a function of diameter using a magnetic pump to control speed, power, and velocity of that jet throughout the casting,” said Wagstaff. “The great thing about jets is they are pretty well defined, we understand how they expand, how their forces are distributed as a function of time, as a function of space, so they are a relatively easy phenomenon to study. We ended up coupling magnets with the jet and built a noncontact magnetic pump to generate our jet.” The team developed formulas to calculate how fast and how strong the jet power has to be to prevent clustering of defects in the center for a given set of alloying elements and mold dimensions. While officially the researchers report improvement of 20%, Wagstaff says with optimization of the jet pump, improvement up to 60% is possible. According to Carolyn Joseph, a grad student in Allanore's group, small variations in individual grains, or microsegregation, can sometimes be healed by reheating the aluminum casting, but when large-scale uneven distribution occurs with a weak centerline, it is impractical because it would take far too long for the copper or other alloying element to migrate through the material. Using the new jet stirring technique, she takes samples during casting near the two-phase region (slurry), in which grains of solid metal circulate in the liquid aluminum. She does this by rapidly cooling the metal at various locations along the ingot as it is being formed, and she studies the samples under a microscope for differences in grain size, shape, composition, and distribution. “The size of your solid structure, how fine or coarse it is, depends on the rate at which you’re cooling it,” said Joseph. Microscopic images she made of samples showing large grain structures are evidence those grains were solid in the slurry before it was rapidly cooled. “In the liquid, they are mixed, the cooper and aluminum form a solution, but when you go from liquid to solid, there is segregation of the alloying elements,” said Joseph. Grains that form early are depleted in copper and tend to cluster in the center of a slab. “The advantage of this is that it’s an intermediate type of snapshot. Instead of looking at the final cross-section and studying its grain size and composition, we can see it at an intermediate stage, while it’s a semi-solid mixture, what’s going on,” said Joseph. “On the macroscale, you want an even distribution of copper, and that’s what Sam’s mixing has been able to achieve.” Role in recycling Allanore believes the jet-stirred aluminum process can also play a role in recycling. “Not all recycled products of aluminum are the same, because some of them come from a former plane and some of them come from a former beverage can, and these are two different alloys,” he said. “So when it comes to society being able to recycle and make new high-quality aluminum products, we can clearly see that there is an issue of how are we going to deal with those alloying elements.” The work that Allanore has done is seen as one example of how researchers can modify existing technologies so that they become more ready to have more recycled material without compromising at the end with the quality of the product that you are making. “By doing the proper amount of theoretical work and experimental work and working in collaboration, hand-in-hand with industry, we can find these type of solutions that allow higher productivity and more recycled materials, which means less energy and less environmental impact, something very exciting,” said Allanore.Continue reading »
The Southwest is also definable, to an extent, by environmental conditions – primarily aridity. Aridity is the environmental condition in which the net loss of moisture – through transpiration and evaporation – exceeds the net gain through precipitation. In other words, the environmental definition of the American Southwest is simply that it is dry. Causing this aridity is a rather complex set of factors, including: - Persistent high pressure systems - Rain shadow effects - Seasonal patterns of jet stream position and air circulation Aridity in the Southwest, of course, is variable, with some areas losing as more than fourteen times the annual rainfall in actual evaporation. The aridity of the Southwest is compounded by the fact that precipitation typically follows a bi-seasonal pattern comprised of two wet seasons divided by periods of greater dryness. The better known of these wet seasons is the summer monsoon, which lasts from about mid-June to early September. The other wet season is that of the winter months (November through April). The summer monsoons play a strong role in forming the environments of the Southwest, and were critically important to ancient farmers in the region. The monsoons result from a shift in wind direction from west/southwest to south/southeast. The winds from the south bring moisture that forms short-lived, localized storms with the potential for intense rainfall. Flashfloods, hail, lightning, and strong winds are common aspects of summer monsoon storms, and even tornadoes have been known to form as a result. Despite the potential danger and damage, however, the monsoons provide life-giving moisture in a region that is always dry. Like the summer monsoons, the milder storms of winter provide vital moisture. The snowpack accumulated through the winter months in the high country feeds the streams and rivers of the Southwest, and moistens the soil for springtime planting of maize and other crops in high-elevation settings. Without the snowpack, the Southwest suffers severe droughts that are often prolonged because the monsoon rains simply cannot bring enough water to overcome the winter’s lack. Although essentially all of the Southwest shares aridity and bi-seasonal precipitation as common characteristics, topography and elevation provide for immense variability in precipitation, temperature, and biological resources. Topographically, the Southwest encompasses four major physiographic zones – the Colorado Plateau, the Transitional Highlands, the Southern Basin and Range, and the southwestern Plains. The rivers of the Southwest provided microenvironments of great importance to prehistoric people in the Southwest, and many of the most famous southwestern sites are located in these regions. Finally, the environment of the Southwest can also be broken in to life zones, of which Merriam’s are the most commonly used. Life zones describe vegetative and faunal regimes based on precipitation, elevation, and temperate, and provide a simple means for describing portions of the highly variable Southwest. Learn more about the environments of the Southwest:
\|Reventador, stratovolcano in the Amazonian Andes of Ecuador\| A world-wide pulse of magma erupting through the sea bed helped kill off the dinosaurs 66 million years ago, new research has found.A record of volcanism preserved along ancient mid-ocean ridges provides evidence for heightened worldwide magmatic activity 66 million years ago just after the Chicxulub meteor struck Earth, according to University of Oregon scientists. The research, published in Science Advances, points to changes in the strength of gravity above the seafloor, which indicate a transient period of increased volumes of magma being released along ridges that mark the oceanic boundaries of tectonic plates. Volcanism, particularly a massive outpouring of basalt recorded by the Deccan Traps in India, has been in and out of the extinction debate. Rare volcanic events at such a scale are known to cause catastrophic disturbances to Earth's climate and, when they occur, they are often linked to mass extinctions. Since evidence of the meteor strike near present day Mexico surfaced in the 1980s, scientists have debated whether the impact or the Deccan Traps volcanic eruptions was the primary driver for extinction of the dinosaurs. Progressively more accurate dating methods indicate that while the Deccan Traps eruptions were active during the mass extinction, they actually began significantly before the Chicxulub impact, said Leif Karlstrom, a professor in the UO's Department of Earth Sciences and co-author on the study with Byrnes. The meteor is closely aligned in time with the onset of mass extinction, seeming to indicate a dominant role, he said. Still, the near coincidence in time of such globally catastrophic events continues to spur debate. Similar to the impacts that normal tectonic earthquakes sometimes have on wells and streams, Karlstrom said, the study proposed that powerful shaking liberated magma stored in the mantle beneath the Deccan Traps and caused the largest eruptions there. The new National Science Foundation-supported study at the UO adds another layer to the story, said Karlstrom, who also co-authored on the UC-Berkeley research. It suggests that other volcanic activity around the world was triggered by the meteor. Seismic waves moving through the Earth, he said, may have accelerated volcanism already occurring along mid-ocean ridges. "Our work suggests a connection between these exceedingly rare and catastrophic events, distributed over the entire planet," Karlstrom said. "The meteorite's impact may have influenced volcanic eruptions that were already going on, making for a one-two punch." The findings emerged as Byrnes, now a postdoctoral researcher at the University of Minnesota, discovered the evidence for volcanic activity by analyzing publicly available global datasets, including two updated in the last decade, on free-air gravity, ocean floor topography and tectonic spreading rates. Free-air gravity anomalies, measured in milligals, account for variations in gravitational acceleration, found from satellite measurements of additional seawater collecting where the Earth's gravity is stronger. Excess matter on the ocean floor, such as new magma, is a primary cause of elevated marine gravity anomalies. A gal reflects a change in the rate of motion of a centimeter, about 0.4 of an inch, per second squared. Byrnes and Karlstrom found changes in free-air gravity anomalies of between five and 20 milligals associated with seafloor created in the first million years after the meteor. "We found evidence for a previously unknown period of globally heighted volcanic activity during the mass-extinction event," Byrnes said. "This study does not say precisely that this volcanic activity is what killed the dinosaurs. What we are adding to the conversation is global volcanic activity during the known environmental crisis." The gravity data analyzed in the research came from the Scripps Institution of Oceanography at the University of California, San Diego, the seafloor ages from the EarthByte group at the University of Sydney, and seafloor elevation from the National Geophysical Data Center of the National Oceanic and Atmospheric Administration. The study is published in the journal Science Advances.
Topic #10: Sound and Light Activity #1: Sound Waves (November 27, 2017) The purpose of this four-part activity was to introduce and observe the properties of sound waves and how sound moves through different mediums. The first part, Dancing Salt, involved holding a vibrating tuning fork near a cup covered with plastic wrap and a pile of salt on top. We observed that the vibrations of the sound waves caused the air molecules to oscillate, transferring the sound energy to the salt, which also began to oscillate (which is why it’s called “dancing” salt!). The second part of the activity, Singing Wine Glass, observed how sound waves travel along the bottom of a wine glass and bounce back to a person’s ears when he/she rubs a slightly wet finger around the rim of the glass. The Amazing Fork activity involved tying a string around a fork, wrapping the ends of the string around the index fingers, and putting the fingers into the ears. When the fork hit against the table, we observed that the sound waves travelled through the strings, through the fingers, and into the ears, producing a loud sound. The last part of this activity, Longitudinal and Transverse Waves, was completed using a long slinky. One person held each end of the slinky and took turns oscillating it back in forth in order to illustrate the longitudinal (left/right) movement for sound waves and the transverse (up/down) movement for light waves. I would introduce the concept of sound to my students by first explaining how sound waves work and how objects can sound different through different mediums. I would have students come up with a list of various sounds they come across in their daily lives. Students could then get into small groups and complete sound activities, such as the Dancing Salt and Amazing Fork tasks. Because students may have difficulty understanding how similar objects can produce different sounds and how sound waves work to produce sounds, the lesson on sound could be made easier by having students describe different sounds and their properties (loud/soft, high/low, etc.). Another idea for an activity that I came across in my research would be a homemade xylophone using glow sticks and glasses filled with different amounts of water (http://www.playathomemomllc.com/2011/07/glow-sticks-thinking-outside-the-box/). Hitting the glasses would produce different variations of sound and the glow sticks would add fun colors to make it appear more like a xylophone! Activity #2: Light Box (November 29, 2017) This activity involved the use of a light box and three mirrors (plane, convex, and concave) in order to observe how light rays reflect from each of the mirrors at different angles. The plane mirror caused the light rays to reflect at an angle less than (an acute angle) the original light ray. The convex mirror caused the reflected light rays to spread out and the concave mirror caused the reflected light rays to focus together. The purpose of this activity was to observe how light waves reflect off of three different types of mirrors. The lesson on light could be introduced to students by first explaining how light waves work and how light can appear differently after being reflected from different objects. I would perform the light box activity with the whole class using a larger light box set-up and then having the students discuss their observations in smaller groups. Difficulties with this activity may include differentiating between the different types of mirrors, as well as sketching the reflections of the light. As mentioned before, this activity could be made easier by using a larger set-up for the whole class in order to ensure that all students understand how to complete the activity. Another fun extension would be to use colored lights to observe the reflections!
By Kaitlyn Gerber, Carleton College Scientists have long known that the lungfish, a four-legged freshwater fish that can breathe through lungs as well as gills, is evolutionarily unique. However, a team of researchers at the University of Chicago have made another startling discovery: lungfish can "walk," using their thin limbs to lift their bodies and propel themselves along the bottoms of streams and lakes. Published online in the Proceedings of the National Academy of Scientists, a recent paper has the potential to reshuffle evolutionary history. Previously, scientists had believed that the ability to walk had originated in tetrapods, animals with a backbone and four limbs, who were through to be the first land-dwellers. However, the ability of lungfish to "walk" along the bottom suggests that the motions of walking actually occurred underwater, before transitioning to land. As a result, fossil tracks originally attributed to early tetrapods may actually be from the ancestors of the lungfish. The study originated when Heather King, a doctoral student at the University of Chicago, observed strange movements in an African lungfish belonging to Dr. Michael Coates, the study's co-author. "If you just look at the lungfish," said King in an interview with Scientific American, "you would think it was impossible for it to walk. It doesn’t have a sacrum, which was thought necessary for the animal to lift itself off the ground, and it doesn't have anatomical feet." King and her colleagues designed a special tank that monitored the lungfish's every move with video cameras, which revealed that the lungfish commonly use their hind, or pelvic, limbs to elevate themselves and push their bodies forward. "This is all information we can only get from a living animal," explained King in an interview. "Because if you were just to look at the bones, like you would with a fossil, you might not ever know these motions could occur." At various points, the lungfish both "bounded," using both pelvic limbs at the same time, and "walked," moving its limbs in alternating motion. Because it can apparently rotate each limb and place each footfall in front of the joint, the motion suggests that some creatures would have been capable of producing some of the fossil tracks that had been attributed to primitive tetrapods. In particular, sets of tracks discovered in early 2010 surprised scientists because they were 395 million years old -- 20 million years older than the earliest tetrapods in the fossil record. If these footprints do, in fact, belong to a common ancestor of both the lungfish and the tetrapods, they may indicate that when the tetrapods appeared, the ability to walk had already evolved. "It's tempting to attribute alternating impressions to something like the footfalls of an early tetrapod with digits, and yet here we've got good evidence that living lungfish can leave similar sequences of similar gait," Michael Coates, professor of Organismal Biology and Anatomy at the University of Chicago, explained in a statement. However, "the fin or limb use thought to be unique to tetrapods is actually more general." Below is a segment of King's footage, in which the lungfish "walks" forwards with its pelvic limbs. Video Credit: The University of Chicago Kaitlyn Gerber is a sophomore at Carleton College, where she plans to major in biology. Originally from Ridgefield, CT, she is an active soccer player and science fan, especially of ecology and astronomy.
The Boreal Forest: Earth's Green Crown Canada's vast boreal forest is among the largest intact forest ecosystems left on earth, and must be preserved. Photo: Northern Images / Wayne Sawchuk Moose are so tightly bound to the boreal forest that one nickname for this ecosystem is the "spruce-moose forest." The largest members of the deer family, moose are enormous animals; bulls weigh between 900 and 1200 pounds and stand about six feet high from hoof to shoulder. Moose are what's called a fire-dependent species. They eat aquatic vegetation and various parts of deciduous trees -- leaves in summer and twigs and buds in winter. Although they do munch on balsam fir, the dominant conifers of the boreal forest are not on their diet. How is it, then, that moose do so well in the boreal forest? The answer is in the frequent wildfires that rage through the boreal. In the aftermath of a forest fire, most of the first growth that regenerates from or colonizes the blackened landscape is deciduous -- sun-loving aspens, birch, willows and other deciduous trees and shrubs. Moose begin to invade a burn a year or two after the fire to take advantage of this smorgasbord. With food available in abundance, cows frequently give birth to twins and the area's moose population will expand rapidly and remain high until conifers begin to mature and crowd out the deciduous trees. Fire is a crucial element of boreal ecology, and many boreal plants and animals flourish in the aftermath of wildfires. Believe it or not, timber-industry advocates have tried to use this as justification for the practice of clearcutting. "It's good for the forest," they say, and argue that it mimics the way forest fires kindle natural regeneration. Industrial clearcutting causes soil degradation and erosion, lowers water quality, reduces biodiversity, and drastically alters forest habitat and wildlife behavior. last revised 7/20/2004 Sign up for NRDC's online newsletter NRDC Gets Top Ratings from the Charity Watchdogs - Charity Navigator awards NRDC its 4-star top rating. - Worth magazine named NRDC one of America's 100 best charities. - NRDC meets the highest standards of the Wise Giving Alliance of the Better Business Bureau. - Q&A: Documentary Filmmaker Ken Burns on National Parks - Ken Burn spoke to OnEarth about his motivation for his new documentary series on America's national parks. - In the Canadian Boreal Forest, a Conservation Ethic at Work - After fighting successfully for years to keep destructive logging, hydropower and mining projects out of their traditional territory, the people of Poplar River are now working to secure permanent protection for their boreal forest homeland.
Slavery was fundamental to the early romans because rome was an agrarian society, and there was always a need for farm labor not all roman slaves were the defeated enemy: some were purchased at auction, others were freemen enslaved through their own misdeeds. What the life of a female slave in ancient rome was like female slaves of ancient rome women of ancient rome were often abandoned as babies or young girls, sometimes these children were taken by dealers and sold into slavery if the man of the house went to far into debt, him and the rest of his. The history of slavery dates back to a time well before the founding of rome historical records indicate that slavery had been in existence four thousand years before the birth of christ in many civilizations, the use of slaves was a way of life. In rome, on the other hand, slavery began to yield to tenancy and the antecedents of serfdom before the fall of the empire,. Roman slavery and the question of race marble statue of possible african slave in rome most historians of the roman world have decoupled the concepts of bondage and race that are central to the arguments justifying the enslavement of millions of people in the united states and other modern western nations. Slavery in rome underwent quite a few changes in the republic and the empire as a result of slave rebellions and other shifts in policy i would probably argue that there was more difference between slavery in rome at different time periods than there was between slavery in early rome and in the greek city states. Start studying slavery in the roman empire learn vocabulary, terms, and more with flashcards, games, and other study tools 90% of the residents of rome were. Kids learn about slavery during ancient rome including how someone became a slave, slave work, how they were treated, freedmen, rebellions and the servile wars, and fun facts. Roman slavery slavery was an important part of the ancient world, and it was an integral piece of roman daily life and the economy though slavery was practiced all over the mediterranean, and was abundant in the east, its impact in other places was not felt nearly as much as it was in rome and her empire. Slavery in the early roman empire slavery was considered normal in virtually all cultures in ancient times, and the romans were no exception in rome, proof. Slavery in rome a person who is forced to work for another, usually without pay is called a slave and slavery is the use of slaves to get work done (wikipedia) the institution of slavery is as old as civilization. Roman religious toleration: the senatus consultum de bacchanalibus, 186 bce, from livy, history of rome, book xxxix [at this site] roman religiones licitae and illicitae , c 204 bce - 112 ce [at this site. When did slavery end in rome is employment a modern kind of slavery how did slavery end in canada when did slavery end in italy is it impossible to end slavery. Rome's dependence upon slaves has been well established in terms of economics and general society this paper, however, seeks to demonstrate this dependence, during the end of the republic and. Media in category slavery in ancient rome the following 44 files are in this category, out of 44 total. This book, first published in 1994, is concerned with discovering what it was like to be a slave in the classical roman world. Learn more about slavery in rome for more information on rome, log onto hbocom watch rome online at hbo go® with hbo go, you can wa. I suggest, therefore, that asking whether a lot of people in ancient rome felt guilty about owning slaves may be a red herring, a notion called forth by our inculturation which abhors the institution of slavery as criminal and inhumane. Slaves of ancient rome like other ancient civilisations, slavery was an integral part of society in ancient rome slaves in rome consisted of a sizeable portion of the population and were involved in a variety of work. Slavery after rome, 500-1100 offers a substantially new interpretation of what happened to slavery in western europe in the centuries that followed the fall of the roman empire. I'd have to think hard to remember my classes in roman law, so let me offer you this i once was at a conference on it and law in austria -- the rechtsinformatiksgespräche" in salzburg. Slavery was the practice of taking a human being and making them do the work of another by force this was practiced through out the ancient world and especially in rome and greece. Slavery was an ever-present feature of the roman world slaves served in households, agriculture, mines, the military, manufacturing workshops, construction and a wide range of services within the city. Slavery in ancient rome roman slaves played an important role in society and the economy besides manual labor, slaves performed many domestic services they could.
Some types of carbohydrate molecules include monosaccharides, disaccharides and polysaccharides. These molecules are often called sugars. Other carbohydrate molecules are oligosaccharides and nucleotides. Carbohydrates are regarded as the most plentiful compounds available on earth.Continue Reading Commonly referred to as saccharides, carbohydrates are molecular compounds consisting mostly of three elements: hydrogen, carbon and oxygen. Monosaccharides, often called simple sugars, are the simplest form of carbohydrate and are the basic building blocks of complex carbohydrates. They are represented with a general formula, (C•H2O) n, where n can take such values as 3, 5 or 6. Monosaccharides can be categorized based on the number of carbon atoms in a molecule. Trioses, such as glyceraldehyde, have three carbon atoms. Pentose, including ribose and deoxyribose, have five carbon atoms. Hexoses, such as fructose, glucose and galactose, consist of six carbon atoms. Monosaccharides are the principal source of energy for organisms. Disaccharides are made up of two monosaccharides linked by a covalent bond known as glycosidic linkage. These are the simplest polysaccharides, and include sucrose and lactose. The unmodified disaccharide has the formula, C12H22O11. Polysaccharides are formed from a series of reactions of monosaccharides. The process involves addition of one unit at a time resulting into a large molecule via condensation polymerization. The most common types of polysaccharides include starch and glycogen. Starch is made strictly by plants, while glycogen is made strictly by animals.Learn more about Atoms & Molecules
Copyright © 2007 Dorling Kindersley Earthworms are the most familiar worms, but there are thousands of other types of these soft, legless creatures. Some are microscopic, others grow to several yards long. Earthworms and roundworms are tube-shaped. Flatworms are shaped like leaves or ribbons. Worms live on land and in water and can be found in virtually every habitat on Earth. Earthworms live in the soil. Leeches and bloodworms inhabit ponds and rivers. Most ribbon worms and some flatworms live in the oceans. Ragworms and lugworms are found on the seashore. Some worms are PARASITES that live on or inside other animals. Some flatworms have simple eyes that can detect light, but most worms are blind. Their most important sense is touch. The earthworm’s skin picks up vibrations caused by sounds or movements. Some predatory worms have sensitive tentacles on their heads, which help them to capture their food. There are over 100,000 species of worm in three main phyla: Parasites live on or inside other animals or plants, called their hosts. They feed on the blood or tissues of their host, or steal its food. Some parasitic worms in people survive without their host even noticing. Others can cause serious diseases. Leeches use suckers on their head and tail to latch on to animals, including humans, in order to suck their blood. They inject a chemical that keeps the host’s blood flowing freely. This lets them feed until they are bloated; then they drop off. Leeches lurk in ponds, streams, and other wet places. Tapeworms live in the guts of animals such as pigs, cats, and humans. The host becomes infected when it eats food containing tapeworm eggs or young. Inside the gut, the worm feeds on the host’s half-digested food. As it matures, the worm produces small packages of eggs, which pass out of the victim’s body.
Self-harm is the intentional infliction of physical injury to oneself. This practice is more prevalent among teenagers than other age groups, particularly those teens who have trouble coping with emotion. Common forms of self-harm include hair pulling, burning (often with a cigarette), biting and cutting. Self-mutilation and self-harm are generally interchangeable terms, but most of the recent literature favors the term self-harm. Awareness of self-harm has increased significantly in recent years. This heightened awareness has fueled research studies on how best to help teens who need to stop engaging in self-harm. The current approach includes both short-term and long-term goals. The short-term goal is to teach teens how to distract themselves when they feel the urge to self-harm. The long-term treatment goal is to address the underlying emotional issues that provoke these urges. Importantly, studies show that treatment is far more effective if the teen wants to stop self-harming and is a willing participant in treatment. Short-Term Goal: Stop Self-Harming When the desire to engage in self-harm arises, often the urge can be stifled if the teenager focuses on some kind of distraction. Many teens find the following activities are helpful diversions: - Cleaning or tidying up their rooms - Dancing to music - Going for a walk - Playing sports or running - Reading a favorite book or magazine - Taking a shower. If the urge to self-harm is related to feeling of anger, sometimes punching a pillow or tearing a piece of paper can be a helpful outlet. The key is to stay busy and active until the feelings subside. Self-harming is a dangerous activity. Learning how to divert the impulse to self-harm keeps the teenager out of immediate danger. However, the underlying reasons that make a person want to self-harm need to be addressed in order to ensure the teen learns healthy ways to express emotion and cope with all the stresses that accompany the transition into adulthood. Long-Term Goal: Address Underlying Issues To address the reasons why a person wants to self-harm, professional counseling is often advised, preferably with a therapist trained in treating cutting or other forms of self-mutilation. Teenagers who practice self-harm tend to be introverted and may have difficulty talking openly about their innermost feelings. Therefore, a therapist that the teen feels comfortable with, and who will be supportive, is important. Typically, the therapist will request one-on-one sessions with the teen as well as family counseling sessions that include the teen’s parents. Depending on what the counseling reveals, the therapist may recommend that the teen take medication to treat underlying psychological issues. The most commonly prescribed medications for teenagers trying to overcome self-harming tendencies are antidepressants. Due to potential severe side effects, these decisions are made on a case-by-case basis. Teens that self-harm often struggle with emotional issues, but self-harm doesn’t necessarily indicate an underlying psychological disorder. In some cases, however, an underlying mental illness is present — such as depression or borderline personality disorder — that is contributing to the drive to self-harm. Therapy can help identify and treat such mental illnesses. American Academy of Child Adolescent Psychiatry. (1999). Facts for families: Self-injury in adolescents. Retrieved August 17, 2010, from http://aacap.org/page.ww?name=Self-Injury in Adolescents
An electroencephalogram (EEG) is a test to detect problems in the electrical activity of the brain. Electroencephalogram; Brain wave test How the test is performed: Brain cells communicate with each other by producing tiny electrical impulses. In an EEG, this faint electrical activity is measured by putting electrodes on the scalp. The test is performed by an EEG technician in your health care provider's office, at a hospital, or at an independent laboratory. You will be asked to lie on your back on a bed or in a reclining chair. The technician will apply between 16 and 25 flat metal disks (electrodes) in different positions on your scalp. The disks are held in place with a sticky paste. The electrodes are connected by wires to an amplifier and a recording machine. The recording machine converts the electrical impulses into patterns that can be seen on a computer screen, as well as stored on a computer disk. Before computers, the activity was printed on paper. In either case, the electical activity looks like a series of wavy lines. You will need to lie still with your eyes closed because any movement can alter the results. You may be asked to do certain things during the recording, such as breathe deeply and rapidly for several minutes or look at a bright flashing light. How to prepare for the test: You will need to wash your hair the night before the test. Do not use any oils, sprays, or conditioner on your hair before this test. Your health care provider may want you to stop taking certain medications before the test. Do not change or stop medications without first talking to your health care provider. You should avoid all foods containing caffeine for 8 hours before the test. Sometimes it is necessary to sleep during the test, so you may be asked to reduce your sleep time the night before. If you're asked to sleep as little as possible before the test, don't consume any caffeine, energy drinks, or other products that help you stay awake. How the test will feel: This test causes no discomfort. Although having electrodes pasted onto your skin may feel strange, they only record activity and do not produce any sensation. No significant electricity passes from the electrode into your skin. Why the test is performed: EEG is used to help diagnose if you're having seizures and if so, what type. An EEG is also used to find the causes of confusion , and to evaluate head injuries , tumors, infections, degenerative diseases such as Alzheimer's disease, and abnormal changes in body chemistry that affect the brain. It is also used to evaluate problems with sleep ( sleep disorders ) and to investigate periods of unconsciousness. The EEG may be done to show that the brain has no activity, in the case of someone in a deep coma. It can be helpful when trying to decide if someone is brain dead. EEG can not be used to measure intelligence. Brain electical activity has certain frequencies (the number of waves per second) that are normal for different levels of consciousness. For example, brain waves are faster when you are awake, and slower when you're sleeping. There are also normal patterns to these waves. These frequencies and patterns are what the EEG reader looks for. What abnormal results mean: Abnormal results on an EEG test may be due to: - An abnormal structure in the brain (such as a brain tumor ) - Attention problems - Tissue death due to a blockage in blood flow (cerebral infarction) - Drug or alcohol abuse - Head injury - Inflammation of the brain (encephalitis ) - Hemorrhage (abnormal bleeding caused by a ruptured blood vessel) - Migraines (in some cases) - Seizure disorder (such as epilepsy or convulsions ) - Sleep disorder (such as narcolepsy ) Note: A normal EEG does not mean that a seizure did not occur. What the risks are: The procedure is very safe. However, the flashing lights or fast breathing (hyperventilation ) required during the test may trigger seizures in those with seizure disorders. The health care provider performing the EEG is trained to take care of you if this happens. It may be difficult to get the paste out of your hair, but it should come out after a few washings with regular shampoo. Foldvary-Schaefer N, Wyllie E. Epilepsy. In: Goetz, CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2007: chap 52.
Interactive Number Simulation Created from Three Simple Rules - Each number N creates a circle with Radius = N. - The Circumference of each circle is divided by N, creating an Arc of Length = Circumference / N. - Each arc makes a complete rotation in N iterations. Each arc represents its number spacially by its length, and temporally by the number of iterations required to make a complete rotation. For example, the number 2 arc is half its circle in length, and takes 2 iterations to make a complete rotation. The number 3 arc is a third its circle in length, and takes 3 iterations to complete a rotation, and so on for all numbers. Each arc is the same length since: Length = Circumference / N, and Circumference = 2 * PI * N Length = 2 * PI * N / NLength = 2 * PI The simulation starts with all arcs in horizontal alignment. When an arc comes back into horizontal alignment, that means it is a divisor of the current number of iterations . Iteration numbers with no arcs in alignment are prime numbers , and are marked in Red. Iteration numbers with factors, are , and are marked in White. pattern is a direct consequence of only the above three rules , and is in no way forced, or coerced to fit that shape.
The differences between the 'moderates' and the 'extremists' were as below: a) The moderates had faith in gradual reforms whereas the nationalists believed that the swaraj is their birth right. b) The moderates believed in the theory of mendicancy but the extremists were against it. c) Moderates were against an all out struggle against the British but the nationalists wanted to mobilise the whole country against the British rule. d) The moderates believed that the British could be persuaded to see the justness of their demands but on the other hand, the nationalists were of the view that the demands could be realised only by putting pressure on the British Government. e) The moderate leaders were sent to jails but the nationalists were beaten, handcuffed and sent to jail several times. The nationalists were more popular among the masses in comparison to moderates. Methods adopted by the nationalists to achieve their aim : The nationalists did not believe in the constitutional methods. They favoured the use of force and revolutionary methods to achieve their aims. They did not believe in petitions, appeals and memorandums and they followed harsh methods and resorted to passive resistance. The nationalists believed in the strength of Indian masses. They believed in launching a continued struggle against the British. They promoted the national movement into mass movement. Swadeshi was another method adopted by the nationalists. Its main aim was to hit the Britishers economically. They promoted a clear-cut break from the constitutional methods followed by the moderates. Boycott was a weapon used by them to draw the attention of the Britishers. They not only boycotted the British goods but also boycotted government services, titles and honours. The nationalists laid more emphasis on the national education. Special institutions were set up to impart education as per the needs of the nation. There was a need for promoting an education which would strengthen national feelings. On 15th August 1906, the National Council of education was set up.
On this day in 1953, Cambridge University scientists James D. Watson and Frances H.C. Crick announce that they have determined the double-helix structure of DNA, the molecule containing human genes. Though DNA–short for deoxyribonucleic acid–was discovered in 1869, its crucial role in determining genetic inheritance wasn’t demonstrated until 1943. In the early 1950s, Watson and Crick were only two of many scientists working on figuring out the structure of DNA. California chemist Linus Pauling suggested an incorrect model at the beginning of 1953, prompting Watson and Crick to try and beat Pauling at his own game. On the morning of February 28, they determined that the structure of DNA was a double-helix polymer, or a spiral of two DNA strands, each containing a long chain of monomer nucleotides, wound around each other. According to their findings, DNA replicated itself by separating into individual strands, each of which became the template for a new double helix. In his best-selling book, The Double Helix (1968), Watson later claimed that Crick announced the discovery by walking into the nearby Eagle Pub and blurting out that “we had found the secret of life.” The truth wasn’t that far off, as Watson and Crick had solved a fundamental mystery of science–how it was possible for genetic instructions to be held inside organisms and passed from generation to generation. Watson and Crick’s solution was formally announced on April 25, 1953, following its publication in that month’s issue of Nature magazine. The article revolutionized the study of biology and medicine. Among the developments that followed directly from it were pre-natal screening for disease genes; genetically engineered foods; the ability to identify human remains; the rational design of treatments for diseases such as AIDS; and the accurate testing of physical evidence in order to convict or exonerate criminals. Crick and Watson later had a falling-out over Watson’s book, which Crick felt misrepresented their collaboration and betrayed their friendship. A larger controversy arose over the use Watson and Crick made of research done by another DNA researcher, Rosalind Franklin, whose colleague Maurice Wilkins showed her X-ray photographic work to Watson just before he and Crick made their famous discovery. When Crick and Watson won the Nobel Prize in 1962, they shared it with Wilkins. Franklin, who died in 1958 of ovarian cancer and was thus ineligible for the award, never learned of the role her photos played in the historic scientific breakthrough.
Role of the Adult and the Environment - The child depends on the adult to provide the environment and the opportunity to use these tendencies to their fullest in order to fulfill their needs. The adult should provide for each tendency as listed above, with the understanding that while each one is important throughout life, there are sensitive periods for each one in which needs and other tendencies are most fully strengthened and matured. - The physical environment should be simple, beautiful and orderly, with plenty of room to move around, as well as an arrangement which requires both gross and fine motor movement; minimal changes only as needed and with the participation of all affected persons. - A regular routine should be established with the children, again with the children participating in any necessary changes, i.e. with forewarning or other preparation. The child thrives on hearing real language, enunciated clearly, not baby talk or watered down sentences; he needs guidance and advice for specific social situations as they present themselves. - The child needs to see excellent role models, who perhaps make mistakes but are quick to recognize them, ask forgiveness and improve themselves. - The child needs opportunities for rest and reflection after moment of intense work, therefore simpler activities should always be present in the environment to which the child can return at any time. - The adult should allow the child to participate in the world around him, opening and closing doors and drawers, helping to prepare or clean up for various family and social activities. - The adult should move at the child’s pace; there should be substantial enough time to allow for plenty of repetition without unnecessary interruption; materials and activities which require exactness, including glass and other fragile items which require exactness of movement; materials at the child’s level to promote usage. - Mistakes should be expected and almost encouraged, with materials, activities and words set up in a manner which allows for auto-correction.
The way by which plants and animals are put in groups is known as categorization and science of categorization is known as nomenclature or taxonomy. Taxonomy is constructed of nomenclature (naming) and systematics (placing into groups) that is done according to resemblances and dissimilarities. Nomenclature or taxonomy in biology is binominal pursuing work of Carl-Linnaeus. By the binominal system every organism has 2 Latin names (that are globally settled to evade uncertainty of local names). The 2 Latin names are specific and generic names. This is same approach you have the initial name and the family name. Generic name starts with capital letter whereas specific starts with small letter. Generic name may be shortened in first letter of word like Homo Sapiens can be written in form of H. Sapiens. Therefore hierarchy can be offered starting with highest so: Every group has the number of lower hierarchy. Sub-phylum vertebrata is build of 6 classes, whereas class mammalia is constructed of 19 orders and so on. In animal subphylum only class mammalia have hairs and feed the young with milk. Though reptiles, mammalian, amphibian fishes and birds have vertebral column, and so all are known as vertebrae. The word species explains group of directly associated organisms that are able to interbreeding make fertile offspring. But there are some omissions to the definition. By inference, exception to underlined description would signify that when few members of similar species interbreed, the offspring are not fertile. At times 2 genetically connected organisms can create infertile offspring as is case of the cross between donkey and the cow generating the mule. When members of similar specie, in their effort to live have to adapt to diverse situation, they develop to turn out to be very dissimilar from each other that they cannot interbreed productively to produce fertile offspring. Kinds of Classification: There are 2 major kinds - artificial and natural. The classification is artificial when organisms are set together by thinking of only few simply experimental features. The most utilize categorization is natural and phylogenetic. The Super Kingdoms - Virus and Eukaryote: Living things were clustered in two kingdoms (plants and animals) till lately. It was thought that plants were antotrophic; and animals relied on organic sources. Animals should thus move about to look for their food for which they require the developed nervous system to perform. Conversely plants don't require moving as they can tap from the location raw materials with which they produce. Fact that all cellular forms contain one or other of the 2 opposite characteristics:- i) DNA is not surrounded by nuclear membrane and free in cytoplasm (prokaryotes). ii) DNA surrounded in nuclear membrane (eukaryotes). It signifies that prokaryotes don't have nuclear and that eukaryotes developed from prokaryotes. The Viruses (Super Kingdom) Viruses considered as boundary between living and non living things. Their main characteristics are: i) They are obligate endoparasites, causing disease to their host. ii) They only reproduce by occupying living cells iii) They are the smallest living organisms iv) They are easy in structure. Have only small piece of nucleic acid, either DNA or RNA enclosed by the protein or lipo-protein coat. Eukaryotae (Super Kingdom) i) Features of viruses are extremely different from eukaryotae whose characteristics are sum up here: ii) Except for protoctista, are multicellular, larger iii) DNA is linear and have in defined nucleus. iv) Contain both DNA and RNA v) Contain several organs in the individual cells. vi) Comprise of complex structures of cell walls and membranes. The Five Kingdoms: a) The Prokaryotae Kingdom: Prokaryotic bacteria and blue-green algae and different primitive pathogens; due to lack of consensus on how to divide organisms in phyla informal names are utilized for main divisions: kingdom Monera, Monera, Prokayotae moneran, moneron - organisms which usually reproduce by asexual budding or fission and whose nutritional form is absorption or photosynthesis or chemosynthesis b) Protoctista Kingdom: This group is least natural of five kingdoms. Protoctista are the group of eukaryotic organisms which could not fit in other 3 (fungi, plantae and animalia) kingdoms. A lot of of them are unicellular. It includes those eukaryotes which are regarded as ancestors of plants, animals and fungi. c) Fungi Kingdom: Fungi are significant organisms which belong to their own kingdom, entirely separate from plants and animals. The immensely varied group of great economic significance, fungi remains immensely under-studied compared to plants. d) The Kingdom Plantae: Plants (autotrophic eukaryotes) arrived on earth only 420 million years ago, while other life have existed here since 3.5 thousand million years ago. Kingdom plantae is known as kingdom Metaphyta. Kingdom plantae comprises all kinds of multicellular, eukaryotic, photosynthetic plants found in the biosphere. Every member of family includes true nucleus and advanced membrane bound organelles. e) Kingdom Animalia: Animals are one of four eukaryote kingdoms. They are heterotrophic, multicellular, ingest food, digest food within and egest undigested wastes. Similar to plantae, rest of variations among animal beyond description just given rely on evolutional trend and adaptation to fifferent hapitats. Specification Identification Keys: The key is the method by which biologists easily recognize the organism. To do the key these are steps you should take: i) Write observable characteristics like shape, number of appendages, color, segments. ii) Match them with diagnostic traits of the particular group keys like these could be explained as artificial as they deal only with forms. Though several keys permit organism to be categorized in the natural phylogenetic hierarchical classification system. Tutorsglobe: A way to secure high grade in your curriculum (Online Tutoring) Expand your confidence, grow study skills and improve your grades. Since 2009, Tutorsglobe has proactively helped millions of students to get better grades in school, college or university and score well in competitive tests with live, one-on-one online tutoring. Using an advanced developed tutoring system providing little or no wait time, the students are connected on-demand with a tutor at www.tutorsglobe.com. 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Arrays of ObjectsEdit composition nested structure By now we have seen several examples of composition (the ability to combine language features in a variety of arrangements). One of the first examples we saw was using a method invocation as part of an expression. Another example is the nested structure of statements: you can put an if statement within a while loop, or within another if statement, etc. Having seen this pattern, and having learned about arrays and objects, you should not be surprised to learn that you can have arrays of objects. In fact, you can also have objects that contain arrays (as instance variables); you can have arrays that contain arrays; you can have objects that contain objects, and so on. In the next two chapters we will look at some examples of these combinations, using Card objects as an example. If you are not familiar with common playing cards, now would be a good time to get a deck, or else this chapter might not make much sense. There are 52 cards in a deck, each of which belongs to one of four suits and one of 13 ranks. The suits are Spades, Hearts, Diamonds and Clubs (in descending order in Bridge). The ranks are Ace, 2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen and King. Depending on what game you are playing, the rank of the Ace may be higher than King or lower than 2. If we want to define a new object to represent a playing card, it is pretty obvious what the instance variables should be: rank and suit. It is not as obvious what type the instance variables should be. One possibility is Strings, containing things like "Spade" for suits and "Queen" for ranks. One problem with this implementation is that it would not be easy to compare cards to see which had higher rank or suit. encode encrypt map to An alternative is to use integers to encode the ranks and suits. By ``encode, I do not mean what some people think, which is to encrypt, or translate into a secret code. What a computer scientist means by ``encode is something like ``define a mapping between a sequence of numbers and the things I want to represent. For example, tabularl c l Hearts & & 2 Diamonds & & 1 Clubs & & 0 tabular The obvious feature of this mapping is that the suits map to integers in order, so we can compare suits by comparing integers. The mapping for ranks is fairly obvious; each of the numerical ranks maps to the corresponding integer, and for face cards: tabularl c l Queen & & 12 King & & 13 tabular that they are not part of the Java program. They are part of the program design, but they never appear explicitly in the code. The class definition for the Card type looks like this: verbatim class Card int suit, rank; public Card () this.suit = 0; this.rank = 0; public Card (int suit, int rank) this.suit = suit; this.rank = rank; As usual, I am providing two constructors, one of which takes a parameter for each instance variable and the other of which takes no parameters. To create an object that represents the 3 of Clubs, we would use the new command: Card threeOfClubs = new Card (0, 3); The first argument, 0 represents the suit Clubs. The printCard methodEdit When you create a new class, the first step is usually to declare the instance variables and write constructors. The second step is often to write the standard methods that every object should have, including one that prints the object, and one or two that compare objects. I will start with printCard. String!array of array!of String In order to print Card objects in a way that humans can read easily, we want to map the integer codes onto words. A natural way to do that is with an array of Strings. You can create an array of Strings the same way you create an array of primitive types: String suits = new String ; Then we can set the values of the elements of the array. suits = "Clubs"; suits = "Diamonds"; suits = "Hearts"; suits = "Spades"; Creating an array and initializing the elements is such a common operation that Java provides a special syntax for it: String suits = "Clubs", "Diamonds", "Hearts", "Spades" ; The effect of this statement is identical to that of the separate declaration, allocation, and assignment. A state diagram of this array might look like: reference String!reference to The elements of the array are references to the Strings, rather than Strings themselves. This is true of all arrays of objects, as I will discuss in more detail later. For now, all we need is another array of Strings to decode the ranks: String ranks = "narf", "Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King" ; The reason for the "narf" is to act as a place-keeper for the zeroeth element of the array, which will never be used. The only valid ranks are 1--13. This wasted entry is not necessary, of course. We could have started at 0, as usual, but it is best to encode 2 as 2, and 3 as 3, etc. Using these arrays, we can select the appropriate Strings by using the suit and rank as indices. In the method printCard, verbatim public static void printCard (Card c) String suits = "Clubs", "Diamonds", "Hearts", "Spades" ; String ranks = "narf", "Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King" ; System.out.println (ranks[c.rank] + " of " + suits[c.suit]); the expression suits[c.suit] means ``use the instance variable suit from the object c as an index into the array named suits, and select the appropriate string. The output of this code Card card = new Card (1, 11); printCard (card); is Jack of Diamonds. The sameCard method The word ``same is one of those things that occur in natural language that seem perfectly clear until you give it some thought, and then you realize there is more to it than you expected. ambiguity natural language language! For example, if I say ``Chris and I have the same car, I mean that his car and mine are the same make and model, but they are two different cars. If I say ``Chris and I have the same mother, I mean that his mother and mine are one and the same. So the idea of ``sameness is different depending on the context. When you talk about objects, there is a similar ambiguity. For example, if two Cards are the same, does that mean they contain the same data (rank and suit), or they are actually the same Card object? To see if two references refer to the same object, we can use the == operator. For example: Card card1 = new Card (1, 11); Card card2 = card1; if (card1 == card2) System.out.println ("card1 and card2 are the same object."); This type of equality is called shallow equality because it only compares the references, not the contents of the objects. equality identity shallow equality deep equality To compare the contents of the objects---deep equality---it is common to write a method with a name like sameCard. verbatim public static boolean sameCard (Card c1, Card c2) return (c1.suit == c2.suit && c1.rank == c2.rank); Now if we create two different objects that contain the same data, we can use sameCard to see if they represent the same card: Card card1 = new Card (1, 11); Card card2 = new Card (1, 11); if (sameCard (card1, card2)) System.out.println ("card1 and card2 are the same card."); In this case, card1 and card2 are two different objects that contain the same data so the condition is true. What does the state diagram look like when card1 == card2 is true? In Section incomparable I said that you should never use the == operator on Strings because it does not do what you expect. Instead of comparing the contents of the String (deep equality), it checks whether the two Strings are the same object (shallow equality). The compareCard methodEdit compareCard operator!conditional conditional operator For primitive types, there are conditional operators that compare values and determine when one is greater or less than another. These operators (< and > and the others) don't work for object types. For Strings there is a built-in compareTo method. For Cards we have to write our own, which we will call compareCard. Later, we will use this method to sort a deck of cards. ordering complete ordering partial ordering Some sets are completely ordered, which means that you can compare any two elements and tell which is bigger. For example, the integers and the floating-point numbers are totally ordered. Some sets are unordered, which means that there is no meaningful way to say that one element is bigger than another. For example, the fruits are unordered, which is why we cannot compare apples and oranges. In Java, the boolean type is unordered; we cannot say that true is greater than false. The set of playing cards is partially ordered, which means that sometimes we can compare cards and sometimes not. For example, I know that the 3 of Clubs is higher than the 2 of Clubs, and the 3 of Diamonds is higher than the 3 of Clubs. But which is better, the 3 of Clubs or the 2 of Diamonds? One has a higher rank, but the other has a higher suit. In order to make cards comparable, we have to decide which is more important, rank or suit. To be honest, the choice is completely arbitrary. For the sake of choosing, I will say that suit is more important, because when you buy a new deck of cards, it comes sorted with all the Clubs together, followed by all the Diamonds, and so on. With that decided, we can write compareCard. It will take two Cards as parameters and return 1 if the first card wins, -1 if the second card wins, and 0 if they tie (indicating deep equality). It is sometimes confusing to keep those return values straight, but they are pretty standard for comparison methods. First we compare the suits: if (c1.suit > c2.suit) return 1; if (c1.suit < c2.suit) return -1; If neither statement is true, then the suits must be equal, and we have to compare ranks: if (c1.rank > c2.rank) return 1; if (c1.rank < c2.rank) return -1; If neither of these is true, the ranks must be equal, so we return 0. In this ordering, aces will appear lower than deuces (2s). As an exercise, fix it so that aces are ranked higher than Kings, and encapsulate this code in a method. Arrays of cardsEdit array!of object object!array of deck The reason I chose Cards as the objects for this chapter is that there is an obvious use for an array of cards---a deck. Here is some code that creates a new deck of 52 cards: Card deck = new Card ; Here is the state diagram for this object: The important thing to see here is that the array contains only references to objects; it does not contain any Card objects. The values of the array elements are initialized to null. You can access the elements of the array in the usual way: if (deck == null) System.out.println ("No cards yet!"); But if you try to access the instance variables of the non-existent Cards, you will get a NullPointerException. exception!NullPointer run-time error null deck.rank; // NullPointerException Nevertheless, that is the correct syntax for accessing the rank of the ``twoeth card in the deck (really the third---we started at zero, remember?). This is another example of composition, the combination of the syntax for accessing an element of an array and an instance variable of an object. The easiest way to populate the deck with Card objects is to write a nested loop: int index = 0; for (int suit = 0; suit <= 3; suit++) for (int rank = 1; rank <= 13; rank++) deck[index] = new Card (suit, rank); index++; The outer loop enumerates the suits, from 0 to 3. For each suit, the inner loop enumerates the ranks, from 1 to 13. Since the outer loop iterates 4 times, and the inner loop iterates 13 times, the total number of times the body is executed is 52 (13 times 4). I used the variable index to keep track of where in the deck the next card should go. The following state diagram shows what the deck looks like after the first two cards have been allocated: As an exercise, encapsulate this deck-building code in a method called buildDeck that takes no parameters and that returns a fully-populated array of Cards. The printDeck methodEdit printDeck print!array of Cards Whenever you are working with arrays, it is convenient to have a method that will print the contents of the array. We have seen the pattern for traversing an array several times, so the following method should be familiar: public static void printDeck (Card deck) for (int i=0; i<deck.length; i++) printCard (deck[i]); Since deck has type Card, an element of deck has type Card. Therefore, deck[i] is a legal argument for printCard. searching linear search findCard The next method I want to write is findCard, which searches through an array of Cards to see whether it contains a certain card. It may not be obvious why this method would be useful, but it gives me a chance to demonstrate two ways to go searching for things, a linear search and a bisection search. Linear search is the more obvious of the two; it involves traversing the deck and comparing each card to the one we are looking for. If we find it we return the index where the card appears. If it is not in the deck, we return -1. public static int findCard (Card deck, Card card) for (int i = 0; i< deck.length; i++) if (sameCard (deck[i], card)) return i; return -1; The arguments of findCard are named card and deck. It might seem odd to have a variable with the same name as a type (the card variable has type Card). This is legal and common, although it can sometimes make code hard to read. In this case, though, I think it works. statement!return return!inside loop The method returns as soon as it discovers the card, which means that we do not have to traverse the entire deck if we find the card we are looking for. If the loop terminates without finding the card, we know the card is not in the deck and return -1. If the cards in the deck are not in order, there is no way to search that is faster than this. We have to look at every card, since otherwise there is no way to be certain the card we want is not there. But when you look for a word in a dictionary, you don't search linearly through every word. The reason is that the words are in alphabetical order. As a result, you probably use an algorithm that is similar to a bisection search: Start in the middle somewhere. Choose a word on the page and compare it to the word you are looking for. If you found the word you are looking for, stop. If the word you are looking for comes after the word on the page, flip to somewhere later in the dictionary and go to step 2. If the word you are looking for comes before the word on the page, flip to somewhere earlier in the dictionary and go to step 2. If you ever get to the point where there are two adjacent words on the page and your word comes between them, you can conclude that your word is not in the dictionary. The only alternative is that your word has been misfiled somewhere, but that contradicts our assumption that the words are in alphabetical order. In the case of a deck of cards, if we know that the cards are in order, we can write a version of findCard that is much faster. The best way to write a bisection search is with a recursive method. That's because bisection is naturally recursive. The trick is to write a method called findBisect that takes two indices as parameters, low and high, indicating the segment of the array that should be searched (including both low and high). To search the array, choose an index between low and high (call it mid) and compare it to the card you are looking for. If you found it, stop. If the card at mid is higher than your card, search in the range from low to mid-1. If the card at mid is lower than your card, search in the range from mid+1 to high. Steps 3 and 4 look suspiciously like recursive invocations. Here's what this all looks like translated into Java code: public static int findBisect (Card deck, Card card, int low, int high) int mid = (high + low) / 2; int comp = compareCard (deck[mid], card); if (comp == 0) return mid; else if (comp > 0) return findBisect (deck, card, low, mid-1); else return findBisect (deck, card, mid+1, high); Rather than call compareCard three times, I called it once and stored the result. Although this code contains the kernel of a bisection search, it is still missing a piece. As it is currently written, if the card is not in the deck, it will recurse forever. We need a way to detect this condition and deal with it properly (by returning -1). The easiest way to tell that your card is not in the deck is if there are no cards in the deck, which is the case if high is less than low. Well, there are still cards in the deck, of course, but what I mean is that there are no cards in the segment of the deck indicated by low and high. With that line added, the method works correctly: public static int findBisect (Card deck, Card card, int low, int high) System.out.println (low + ", " + high); if (high < low) return -1; int mid = (high + low) / 2; int comp = deck[mid].compareCard (card); if (comp == 0) return mid; else if (comp > 0) return findBisect (deck, card, low, mid-1); else return findBisect (deck, card, mid+1, high); I added a print statement at the beginning so I could watch the sequence of recursive calls and convince myself that it would eventually reach the base case. I tried out the following code: Card card1 = new Card (1, 11); System.out.println (findBisect (deck, card1, 0, 51)); And got the following output: verbatim 0, 51 0, 24 13, 24 19, 24 22, 24 23 verbatim Then I made up a card that is not in the deck (the 15 of Diamonds), and tried to find it. I got the following: verbatim 0, 51 0, 24 13, 24 13, 17 13, 14 13, 12 -1 verbatim These tests don't prove that this program is correct. In fact, no amount of testing can prove that a program is correct. On the other hand, by looking at a few cases and examining the code, you might be able to convince yourself. The number of recursive calls is fairly small, typically 6 or 7. That means we only had to invoke compareCard 6 or 7 times, compared to up to 52 times if we did a linear search. In general, bisection is much faster than a linear search, especially for large arrays. Two common errors in recusive programs are forgetting to include a base case and writing the recursive call so that the base case is never reached. Either error will cause an infinite recursion, in which case Java will (eventually) throw a StackOverflowException. recursion!infinite infinite recursion exception!StackOverflow Decks and subdecksEdit Looking at the interface to findBisect public static int findBisect (Card deck, Card card, int low, int high) verbatim it might make sense to treat three of the parameters, deck, low and high, as a single parameter that specifies a subdeck. We took a similar view in Section graphics when we were talking about bounding boxes. In that case I referred to x, y, width and height as if they were a single parameter, a bounding box. parameter!abstract abstract parameter This kind of thing is quite common, and I sometimes think of it as an abstract parameter. What I mean by ``abstract, is something that is not literally part of the program text, but which describes the function of the program at a higher level. For example, when you invoke a method and pass an array and the bounds low and high, there is nothing that prevents the invoked method from accessing parts of the array that are out of bounds. So you are not literally sending a subset of the deck; you are really sending the whole deck. But as long as the recipient plays by the rules, it makes sense to think of it, abstractly, as a subdeck. There is one other example of this kind of abstraction that you might have noticed in Section objectops, when I referred to an ``empty data structure. The reason I put ``empty in quotation marks was to suggest that it is not literally accurate. All variables have values all the time. When you create them, they are given default values. So there is no such thing as an empty object. But if the program guarantees that the current value of a variable is never read before it is written, then the current value is irrelevant. Abstractly, it makes sense to think of such a variable as ``empty. This kind of thinking, in which a program comes to take on meaning beyond what is literally encoded, is a very important part of thinking like a computer scientist. Sometimes, the word ``abstract gets used so often and in so many contexts that it comes to lose its meaning. Nevertheless, abstraction is a central idea in computer science (as well as many other fields). A more general definition of ``abstraction is ``The process of modeling a complex system with a simplified description in order to suppress unnecessary details while capturing relevant behavior. [encode:] To represent one set of values using another set of values, by constructing a mapping between them. [shallow equality:] Equality of references. Two references that point to the same object. [deep equality:] Equality of values. Two references that point to objects that have the same value. [abstract parameter:] A set of parameters that act together as a single parameter. [abstraction:] The process of interpreting a program (or anything else) at a higher level than what is literally represented by the code. encode shallow equality deep equality abstract parameter abstraction
Implications of Each Grouping Although the distinctions between the grouping practices implied by the terms defined above may seem slight, they have significant implications for practice. The ungraded or nongraded approach acknowledges that age is a crude indicator of what children are ready to learn. It emphasizes regrouping children for instruction on the basis of perceived readiness to acquire knowledge and skills, and not according to age. It does not emphasize educational benefits of a learning environment in which children at different knowledge and skill levels work together. In other words the main goal implied by the term nongraded is that of homogenizing children for instruction according to achievement instead of age, even though this was not the original rationale for introducing the term (Lewis, 1969). Several kinds of combined grades and continuous progress practices do not set out to increase the sense of family within the class or encourage children with different levels of knowledge and experience to team together. In contrast, mixedage grouping involves class composition that takes advantage of the heterogeneity of experience, knowledge, and skills in a group of children with an age range of more than one year (Katz et al., 1990). Research on crossage interaction in spontaneous, experimental, and educational settings indicates that a variety of developmental and educational benefits can be obtained from such interaction, especially in the early years (Balaban, 1991). Elkind (1989) recommends mixedage grouping as a developmentally appropriate alternative to a rigid lockstep curriculum and as a way to strengthen teachers' sensitivity to the normal variability of children's developmental trajectories in a single age group. Mixed age grouping can provide older children with the opportunity to be helpful, patient, and tolerant of younger peers' competencies, and thus give them some of the desirable early experiences of being nurturing that underlie parenting and helping others who are different from oneself. Exposure to older children as nurturers provides young recipients with models of behavior they can emulate when they become the older members of a group. Research on crossage interaction, peer tutoring, and cooperative learning indicates that an age range of greater than one year can provide a level of intellectual stimulation that supports the development of both intellectual and academic competence. This sort of learning environment is also likely to generate greater social benefits than sameage groups, especially for children who are atrisk in particular social development categories (Katz et al., 1990).
\|MadSci Network: Physics\| FORCE = MASS * (SPEED^2)/RADIUS I could solve for mass, if I can measure: RADIUS = length of rope, SPEED, and FORCE = whatever my scale is saying the force the rope is being pulled at is. I could simplify my SPEED measurement by using the relation that for a circular path: SPEED = RADIUS * ANGULAR SPEED ANGULAR SPEED is how fast the object completes an orbit in RADIANS. One orbit is 2PI radians (about 6.28 per revolution). I could pick a spot to be my starting point of my circular orbit, like say a line on the ground and keep time of how long it takes me to turn all the way around and face that same direction while holding the rope which is attached to the unknown mass. This time = TIME of ONE ORBIT. The final equation is: FORCE = MASS (RADIUS^2) * 6.28 /(TIME of ONE ORBIT). Rearranging the equation: MASS = FORCE * (TIME of ONE ORBIT) /( 6.28 * (RADIUS^2)). And there are probably other ways someone can come up with to measure mass without gravity. Try the links in the MadSci Library for more information on Physics.
Looking at context, language and form, carol atherton provides a close analysis of the witches in act 1, scene 3 of macbeth. An analysis of macbeth's ambition share flipboard how do the witches in shakespeare's 'macbeth' witches drive the plot why guilt is so important in macbeth. And declares that he will spend the night at macbeth's the only eyewitness account of macbeth in shakespeare's macbeth analysis and. Twelfth night william shakespeare contents plot overview + literary analysis involves examining all the parts of a novel theme a fundamental and. Sight, light, darkness, and blindness we may remember that this is exactly the kind of night macbeth wanted macbeth navigator home \| theme index. The tragedy of macbeth shakespeare homepage of the imperial theme--i thank be bright and jovial among your guests to-night macbeth so shall i. No fear shakespeare by sparknotes features the complete edition of macbeth side-by-side with an accessible, plain english a midsummer night’s dream. Othello the moor of venice by: william shakespeare a playwright biography william shakespeare (26 april 1564 – 23 april 1616)was an english poet and playwright, widely regarded as the greatest writer in the english language and the world's pre-eminent dramatist. Get all the key plot points of william shakespeare's macbeth on macbeth summary from litcharts duncan decides to spend the night in celebration at macbeth's. Shakespeare's macbeth study guide with scholarly the royal patent that changed shakespeare's life soliloquy analysis: now stole upon the time the dead of night. Macbeth (2,118 ) othello (656) romeo william shakespeare's sonnet 1 - analysis i analyze in this paper is william shakespeare's sonnet 1 the main theme of. Literature literary resources (commonly called macbeth) is a play by william shakespeare about a regicide and the tragedy of macbeth, by william shakespeare. Conclusion for macbeth by william shakespeare ties together important themes and answers significant questions that macbeth conclusion character analysis. Macbeth themes shakespeare's macbeth william shakespeare introduces this theme in act i william shakespeare a midsummer night's dream. Free analysis of shakespeare macbeth - in shakespeare’s macbeth, the theme of guilt and conscience william shakespeare, literary analysis. Critical analysis of macbeth paint the night red report shakespeare yr 10 close study of shakespeare - geetha shekar william shakespeare - hamlet. Macbeth study guide contains a biography of william shakespeare, literature essays, a complete e-text, quiz questions, major themes, characters, and a full summary and analysis. You are writing a literary analysis essay on shakespeare's macbeth which of the following is a reliable source of information on the topic - 1589621. Theme of darkness in macbeth english macbeth is a famous play written by william shakespeare theme of darkness appears result show that macbeth is night. Literary critique (romeo and juliet by (romeo and juliet by william shakespeare) othello and macbeth in these, shakespeare's characters present vivid. William shakespeare's use of foreshadowing in macbeth is what makes the play so william shakespeare's macbeth, one of his go to macbeth literary analysis. Dive deep into william shakespeare with extended analysis of macbeth “as written by shakespeare,” there was an a midsummer night. You are writing a literary analysis essay on shakespeare's macbeth which of the following is a reliable source of information on the topic - 4002514. Macbeth by william shakespeare responding to critics requires students to analyze six literary each time covering summary, analysis, context, theme. Macbeth summary notes macbeth • author: william shakespeare background: • based on a true story • macbeth, as a person, actually lived. Literary analysis, shakespeare title: macbeth in william shakespeare's tragedy macbeth we find a both night and a lamp shakespeare gives. Macbeth by william shakespeare home / literature / macbeth analysis literary devices in macbeth symbolism here's what you should remember about shakespeare. Macbeth is a tragedy written by william shakespeare macbeth is shakespeare's and a helpful critical analysis which gives prominence to the theme of. Shakespeare's sonnets with analysis and paraphrase although love is the overarching theme of the sonnets shakespeare personally london.
Equity of Access Equity of access means that all people have the information they need-regardless of age, education, ethnicity, language, income, physical limitations or geographic barriers. It means they are able to obtain information in a variety of formats-electronic, as well as print. It also means they are free to exercise their right to know without fear of censorship or reprisal. In addition to these efforts supporting equity of access, ALA also actively priorities access to information.
Salmonellosis in Gerbils Salmonellosis is a contagious disease caused by infection with the Salmonella bacterium. It is quite rare in pet gerbils and is usually spreads due to the ingestion of food or water that has been contaminated with the infected feces or urine of wild rodents. Infected bedding material can also act as a potential source for transmission of salmonellosis disease in gerbils. An infected gerbil that is being treated for salmonellosis may still continue to infect other animals even thought it does not appear to be sick. It is important to note that this disease has known zoonotic potential, and an infected gerbil can act as a source for the spread of salmonellosis to humans as well. Hence, salmonellosis needs to be managed with caution. Treatment is generally not effective for the control of salmonellosis. Taking steps to prevent the spread of this bacterial infection is the best way to manage salmonellosis in gerbils. Finally, infected gerbils can act as potential sources for the spread of salmonellosis infection to each other, and to humans as well, making this a disease with zoonotic potential. Hence this condition should be managed with caution, with disposable medical grade gloves used for cleaning and handling all things gerbil related (including the gerbil itself), sanitizing or disposing of all gerbil equipment and bedding, and care taken when going from the gerbil to other gerbils, people, or even to other animals. Symptoms and Types Salmonellosis is often fatal for gerbils. The symptoms which may be observed prior to it becoming severe include: - Rough hair coat - Distended abdomen - Diarrhea and resulting weight loss - Miscarriage (in pregnant gerbils) Ultimately it is the Salmonella bacteria that causes this condition. It is typically transmitted through the ingestion of food or water that has been contaminated by the feces of infected animals or insects. However, bedding and other materials in the gerbil's cage may also be contaminated by infected insects or wild rodents. You will need to provide a thorough history of your gerbil's health leading up to the onset of symptoms. Observing the clinical symptoms exhibited by the infected gerbil will help your veterinarian to make a tentative diagnosis, but laboratory work will be necessary for making a confirmed diagnosis. A complete blood profile will be conducted, including a chemical blood profile and a urinalysis. Collecting fecal samples for culturing will also be necessary for identifying the bacterial species that is responsible for the bacterial infection. Only then will your veterinarian be able to conclusively identify the Salmonella bacterium as the underlying cause for your gerbil's condition. An in-depth examination of the properties of urine; used to determine the presence or absence of illness The singular form of the word bacteria; a tiny, microscopic organism only made up of one cell.
Can the temperature of the food we eat affect the intensity of its taste? It depends on the taste, according to a new study by Dr. Gary Pickering and colleagues from Brock University in Canada. Their work shows that changes in the temperature of foods and drinks have an effect on the intensity of sour, bitter and astringent (e.g. cranberry juice) tastes but not sweetness. Their work is published online in Springer's Chemosensory Perception journal. We are all familiar with the effect of temperature on taste -- think about starting to eat or drink something while it is warm and finishing when it has cooled, or vice versa. The same food or beverage can taste different depending on its temperature. In addition, in 20-30 percent of the population, heating or cooling small areas of the tongue draws out a taste sensation without the presence of food or drink. These individuals are known as 'thermal' tasters. Over three sessions, 74 participants recruited from Brock University and the local community (a combination of 'thermal' tasters, 'super' tasters i.e. people who are particularly sensitive to tastes in general, and 'regular' tasters) tasted sweet, sour, bitter and astringent solutions at both 5oC and 35oC. They were then asked to rate the intensity of the tastes over a period of time. For all three types of tasters, temperature influenced the maximum perceived intensity from astringent, bitter and sour solutions, but not from the sweet solutions. Specifically: The authors conclude: "For some individuals, temperature alone can elicit taste sensations. These individuals seem to be more sensitive to tastes in general. What our work shows is that, in addition to these sensitive individuals, the temperature of a specific taste can affect how intense it tastes." Cite This Page:
Plants adapt to their environment inside and outdoors. Although certain plants require more care than others, many plants grow well in little plastic pots on a window sill or balcony. Container plants have more watering needs than plants in the garden. The up side to the small containers is they are easy to move for increased lighting or protection from the elements. Pruning keeps the plants small enough for a little container. It is important to remember the time will come when the plant needs more room and must be transplanted to a larger pot. Cactus plants need more than sand to survive. The soil needed for healthy cactus plants is a mixture of sand, potting soil and perlite. Fill the pot with a quality cactus soil mix and make a well in the center for planting the cactus. Wearing gloves helps protect your hands while planting and caring for the cactus plants. Water generously after planting and refrain from watering again until the soil is dry. Keep the cactus plants in full sun for healthy growth. Kitchen herbs grown in containers provide you with easy access to the savory plants for use in many dishes. Herbs require a quality potting soil, plenty of water and sunlight. Keep the herbs from becoming leggy or spindly by pinching the plants back every week or two. The best way to water the plants is to set the plastic pots in the sink and water with a slow stream of water. Allow the plants to sit and drain for at least 1/2 hour before putting the pots back in the window. Dracaena sanderiana, also known as lucky bamboo, is a member of the lily family and not bamboo. Lucky bamboo needs indirect sunlight to avoid scorching the leaves. While the plant grows in water, lucky bamboo suffers from some of the added chemicals, like fluoride, in tap water. Use spring water or filtered water when watering the lucky bamboo. Add fertilizer every 3 to 4 weeks to supply the necessary nutrients for the plant.
When enormous stresses build and push large intact rock masses beyond their yield limit, faulting of the surface is likely to occur. A fault is a fracture along which movement occurs. The plane that extends into the earth and along which slippage occurs is called the fault plane. The fault dip is the angle from horizontal that the fault plane makes. The map direction that the fault takes is called the strike, measured east or west of true north. Generally, two walls are distinguished, the footwall and hanging wall. The hanging wall moves horizontally, vertically, or in both directions relative to the footwall. We identify the hanging and foot walls relative to the fault plane. The hanging wall is above the fault plane while the foot wall is below. The steep face of an exposed block is called the fault scarp. The fault line is the trace of the fault along the surface.
On this day 95 years ago (25 March, 1920), the Black and Tans arrived in Ireland. The force of Temporary Constables were recruited to assist the Royal Irish Constabulary (RIC) during the Irish War of Independence. The force was the brainchild of Winston Churchill, then British Secretary of State for War, and was recruited in Great Britain in late 1919.Thousands, many of them British World War I veterans, answered the British government’s call for recruits. Their role was to help the RIC maintain control and fight the Irish Republican Army (IRA), the army of the Irish Republic. The nickname “Black and Tans” arose from the colours of the improvised uniforms they initially wore, composed of mixed khaki British Army and rifle green RIC uniform parts. The Black and Tans became infamous for their attacks on civilians and civilian property.
New Leap In Artificial Intelligence May Finally Allow Robots To 'Learn' The iCub humanoid robot will now be able to understand what is being said to it and even anticipate the end of a sentence. Credit:Inserm / P. Latron /iTechPost.com A new iCub robot that may soon actually learn new languages is a stunning development in the field of artificial intelligence — it is an especially dramatic leap considering that in the past robots were simply programmed with information, not capable of adding any through "learning." The experts working on the machine at Europe's National Center for Scientific Research (CNRS), INSERM (Institut nationa de la santo et del la receherch medicale) and the Université Lyon 1 believe that if they can make the polyglot robot a reality, the machine may unlock the door to a true "artificial neuronal network." Like Us on Facebook Such a network would allow human beings to finally "teach" robots how to do an assortment of other activities. The innovation came about thanks to the years the iCub team put into developing a "simplified artificial brain." The brain in turn "reproduces certain types of so-called 'recurrent' connections observed in the human brain," writes Science Daily. The system allows the robot to analyze and understand new phrases. These sentences may include new syntax/grammar structure, as well. Beyond this, the robot will have the ability to link together two different sentences and complete the phrase before spoken. Fashioned with a byzantine foundation powered by 53 separate motors, the iCub is already capable of movement in the head, arms, hands, waist and legs. iCub's development team is currently engaged in giving the robot a sense of touch, as it already possesses a sense of "proprioception" (body configuration) and can see and hear, reports Red Orbit. Before being taught how to "learn" language, Red Orbit says the iCub was taught how to balance on two legs. "In tests with INSERM," continues Red Orbit, "researchers asked the iCub to point to a guitar, shown in the form of a blue object; and then asked the robot to point to a violin, shown as a red object. Prior to each task the robot was required to repeat the sentence and explain that it had fully understood the task it was asked to accomplish." Because the human brain processes language at a real-time speed and creates expectations as people speak, the days of having an actual conversation with an iCub robot are still part of a sci-fi future that only might be coming to a store near you. "At present, engineers are simply unable to program all of the knowledge required in a robot," says Dr. Peter Ford Dominey of the Robot Cognition Laboratory at INSERM and research director at CNRS. "We now know that the way in which robots acquire their knowledge of the world could be partially achieved through a learning process — in the same way as children." In addition to conversing with a robot and truly teaching it to learn, this research could also be of value in treating the linguistics malfunctions of sufferers of Parkinson's disease. Like what you're reading? Follow @profklickberg.
Presentation on theme: "Density a physical property of matter Property = a characteristic that gives a substance identity Properties of Vinegar: - clear liquid - strong odor."— Presentation transcript: Property = a characteristic that gives a substance identity Properties of Vinegar: - clear liquid - strong odor - reacts with baking soda - acidic Physical Properties can be observed without changing the composition of the substance Examples; -Color -Texture -Shape -Hardness -Buoyancy -Viscosity -Miscibility -Density DENSITY StyrofoamBrick Brick is more dense than Styrofoam because there is more mass packed into the same volume (more molecules or atoms in the same space.) Density Density can be defined as unit mass per unit volume Density = Mass / Volume D = m / v Example: Density Density is a property of matter. If you measure the mass and the volume of an object, you can calculate its density using the formula: (g) (mL) D = m/v Density = mass/volume So, the units of density must be…. g/mL The Units for density come from this formula… Why is density measured in g/mL? Because the formula for density is (akagrams per milliliter) (notgee slash em-ell) m mass (in grams) g D = ----- = ------------ -------------- ---- v volume (in milliliters) mL Metric System ssecondTime K or o C Kelvin or degree celsius Temperature LliterVolume ggramMass mmeterLength Unit Symbol UnitQuantity Volume is special because: Volume can be measured in liters (L), milliliters (mL), etc. s or… OR… Volume can be measured in cubic meters (m 3 ) centimeters (cm 3 ), …..etc. Remember; 1 cm 3 = 1 mL 1 cm 3 = 1 mL Remember this geometry? Volume of a cube is …. l x w x h i.e. 4cm x 5cm x 2cm = 40 cm 3 i.e. x (5cm) 2 x 10cm = 250 cm 3 Volume of a cylinder is …. r 2 h Determining the Volume of an Irregularly Shaped Solid 22 mL 32 mL Units of Density: –Mass is measured in g. –Volume is measured in mL or cm 3. –Density is mass / volume, (g) / (mL) (g) / (cm 3 ),so.. density is measured in: g/mL or g/cm 3 1 cm 3 = 1 mL 1 cm 3 = 1 mL DENSITY - an important and useful physical property 13.6 g/cm 3 21.5 g/cm 3 Aluminum 2.7 g/cm 3 Platinum Mercury Density of Gold: 19.30 g/mL Silver: 10.50 g/mL Aluminum: 2.70 g/mL Atoms of some elements are more dense than others. Sample Problem What is the density of 5.0 g of tin that has a volume of 1.2 mL? D = m / v = 4.2 g/mL D = ? m = 5.0 g v = 1.2 mL Steps for Solving Problems 1.Write the shopping list: the unknown variable. (whats the question asking for?) all of the known variables. 2.Write the formula you will be using. 3. Calculate the final answer and include the units. Sample Problem What is the density of 45.0 g of a liquid that has a volume of 62.5 mL? D = m / v = g/mL D = ? m = 45.0 g v = 62.5 mL Variations of the Density Formula: D = m/v v = m/D m = v D Dv m Sample Problem What is the volume of 21.0 g of tin? (Density of Tin = 4.2 g/mL) v = ? D = 4.2 g/mL m = 21.0 g v = m / D v = 5 mL Sample Problem What is the mass of 20 cm 3 of tin? (Density of Tin = 4.2 g/mL) m = ? D = 4.2 g/mL v = 20 cm 3 m = v D m = 84 g = 4.2 g/cm 3 = 20 mL Review: 3 methods of measuring volume: directly using glassware geometry (e.g. l w h ) water displacement (v f – v i ) Variations of the Density Formula: D = m/v v = m/D m = v D 1. Write the unknown variable. 2. Write all the known variables. 3. Convert all variables to similar units. 4. Write formula you will be using. 5. Calculate: Plug and Chug 6. Circle your final answer with correct units.
Looks like you are using an old version of Internet Explorer - Please update your browser ScienceNOW: “Untangling Canine Coiffures” The many differences in dog fur are reducible to just a few genetic factors, a team reports in Science. So what does that teach creationists about the tricks of biology? Dog hair seems to be about as diverse as something can get: it comes in many colors, lengths, thicknesses, and degrees of curliness. Researchers at the (U.S.) National Human Genome Research Institute wondered what the genetic basis was for some of those these differences. The scientists began by keeping things simple: they looked for genetic variation in the genome of just one breed of dog, the dachshund, which comes in short-haired, long-haired, and wiry-haired varieties. After looking at some 50,000 “spots” (pardon the pun) in the genetic codes of 100 dachshunds, the researchers discovered that differences in one location on canine chromosome 13 determine the wiriness of dachshund hair; a particular gene known as R-spondin-2 encodes a protein that results in the wiry hair follicles and produces the characteristic “mustaches” of some dog breeds. Meanwhile, a mutation in a gene called FGF5 correlated with longer hair; 91 percent of the long-haired dogs in the study had the mutation, compared to only 4 percent of the short-haired dogs. The incredible diversity of dog fur is largely due to differences in just three genes. In a corresponding study, the researchers examined the genes of 76 Portuguese water dogs to pin down the genetic cause of curly hair. They learned that a difference in the gene for hair protein keratin caused the curliness. Knowing that differences in those three genes alone resulted in differences in hair length, wiriness, and curliness, the researchers embarked on a bigger project: they analyzed the genomes of dogs from 80 breeds (nearly 1,000 dogs in total) to learn how the identified genetic changes interacted to result in the varieties of dog hair. They discovered that different combinations of the gene types result in the seven coat types most common among the dogs sampled. For example, basset hounds have none of the three mutations, and instead have short, straight-haired coats. Dogs with all three mutations have long, curly hair and mustaches, such as the bichon frisé. (For this very reason, AiG’s Ken Ham has fondly referred to his family’s bichon frisé as a “mutant”—see As I Always Said: “It’s a Mutant!”) Thus, the incredible diversity of dog fur is largely due to differences in just three genes. Cornell University geneticist Gregory Acland commented, “All the unique characteristics are something that occurred once a long time ago and have been preserved ever since.” That’s due not only to the effects of natural selection (e.g., only long-haired dogs surviving in cold climates), but also due to the power of artificial selection (e.g., breeders selecting for certain traits, resulting in dogs with specific characteristics based on everything from farmers’ needs to pet owners’ fancies). What does this study tell creationists? It gives us a good idea of the scope of genetic differences required to account for the diversity within one part of what was probably one created canid kind (extending beyond dogs to wolves, dingoes, etc.). We cannot say for sure how many of these differences are the result of a mutation and how many were simply due to the diverse information God gave each created kind; however, we can get a better idea of how the kind may have changed over the four millennia since Noah’s Ark. Remember, if you see a news story that might merit some attention, let us know about it! (Note: if the story originates from the Associated Press, Fox News, MSNBC, the New York Times, or another major national media outlet, we will most likely have already heard about it.) And thanks to all of our readers who have submitted great news tips to us.
Endothermic and Exothermic Reactions Exothermic and endothermic are common chemical reactions. In this lab, students will measure the changes in temperature during reactions and determine what type of reaction has occurred. 1. Describe the differences between endothermic and exothermic reactions 2. Identify chemical reactions as endothermic or exothermic 3. Measure the change in temperature during a reaction Lesson Materials (view or download) chemistry, chemical changes Last updated: 3/4/2015
What is a blood transfusion? A blood transfusion is donated blood given to patients with abnormal blood levels. The patient may have abnormal blood levels due to blood loss from trauma or surgery, or as a result of certain medical problems. The transfusion is done with one or more of the following parts of blood: red blood cells, platelets, plasma, or cryoprecipitate. What are the potential benefits of a blood transfusion? If your body does not have enough of one of the components of blood, you may develop serious life-threatening complications. - Red blood cells carry oxygen through your body to your heart and brain. Adequate oxygen is very important to maintain life. - Platelets and cryoprecipitate help to prevent or control bleeding. - Plasma replaces blood volume and also may help to prevent or control bleeding. How safe are blood transfusions? Blood donors are asked many questions about their health, behavior, and travel history in order to ensure that the blood supply is as safe as it can be. Only people who pass the survey are allowed to donate. Donated blood is tested according to national guidelines. If there is any question that the blood is not safe, it is thrown away. However, there is still a very small chance that something will go undetected in the screening process. To put this in perspective, let’s look at your chances of getting a disease from a blood transfusion: - HIV: 1 in 2 million cases - Hepatitis C: 1 in 1 million cases - Hepatitis B: 1 in 137,000 cases For comparison, let’s look at your lifetime odds for a few other things: - Struck by lightning: 1 in 700,000 - Deadly plane crash: 1 in 500,000 - Accidental drowning: 1 in 80,000 - Deadly car accident: 1 in 5,000 Additional transfusion risks and reactions: - severe allergic reaction - human error - bacterial contamination - Transfusion-Related Acute Lung Injury (an immune reaction that affects a person’s lungs) - fever, chills, rash - temporary decreased ability to fight infections - fluid overload These reactions may be mild or severe. Most mild reactions are not life-threatening when treated quickly. Severe transfusion reactions may be life-threatening. Are there any alternatives? The alternatives available and how well they work will depend on your situation. If you need a transfusion, sometimes medications can be used in order to help your body to make its own blood. Some medications may also be used to prevent or control bleeding. If the blood loss is too great, or if you are in a potentially life-threatening situation, these alternatives may not work quickly enough to help you. In these instances, there are no other options except for receiving the transfusion. You do have the right to refuse a blood transfusion that your doctor has ordered. You must be aware of the risks and consequences of not accepting the transfusion. As a patient, you have the responsibility to discuss this with your physician before making your decision. Very often, the risks of not receiving a transfusion include loss of life or permanent disability. What can I expect during the transfusion? The nurse will check your blood pressure, pulse, and temperature before the transfusion is started. The blood will be given through your IV. Two nurses will check the blood at your bedside before starting the transfusion. A nurse will check your blood pressure, pulse, and temperature after the transfusion has been running for 15 minutes, and again when the blood is completed. Your transfusion will take anywhere from 1 to 3 hours. It may take a little longer, or it may even take less time depending on what component (part) of blood you are receiving. How do I know if I am having a reaction? A reaction can occur during a transfusion, up to a day following the transfusion, or even up to several months after the transfusion. Your nurse will watch you closely for a reaction. If a reaction occurs, the transfusion will be stopped. During your transfusion, please let your nurse know immediately if you have any of the following symptoms: - bleeding, pain, or new bruising at the IV site - severe back pain - fever, chills - nausea, vomiting - rash, hives, itching - headache, dizziness - cold, clammy skin - chest pain - fast heartbeat - trouble breathing, wheezing - dark or reddish urine - yellowing of the skin or eyes After the transfusion If any of the listed symptoms develop after a blood transfusion, you may be having a transfusion reaction. If you are in the hospital, notify your nurse or doctor immediately. If you have been discharged from the hospital and any of the above symptoms develop, contact your doctor immediately. If you are unable to reach your doctor, call 911 or go to the nearest Emergency Room. After your transfusion, you should rest and take care not to overexert yourself for at least 24 to 48 hours. Once you are discharged, call to schedule a follow-up appointment with your primary care physician. Additional information may be found at: - National Heart, Lung, and Blood Institute. What is a blood transfusion? - Food and Drug Administration. Keeping Blood Transfusions Safe: FDA's Multi-layered Protections for Donated Blood © Copyright 1995-2017 The Cleveland Clinic Foundation. All rights reserved. This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/1/2011…#14755
Why work hard to collect good seed? In agriculture, collecting seed from superior parent stock has been practiced for thousands of years. This technique results in higher yields and environmentally durable plants. This concept, however, has yet to gain widespread acceptance in forestry practice. To maximize yields and quality of trees for plantations, agroforestry, and other uses, the following principles for collecting seed should be observed. One program, two benefits In forestry, as in agriculture, the quality of offspring plants improved populations will result if the seed used to produce them was collected from superior individuals, stands or orchards. Seed quality is measured in two ways. One, by the physical quality of the seed and secondly by the desired physical traits of the resultant mature tree. The benefits of using quality seeds, chosen from selected parent trees, are twofold: improved survival and greater economic returns. Seeds from healthy, well-formed trees provide greater assurance that resulting stock will have good form, survive and better resist stressed conditions due to marginal sites, frequent cutting, or harsh climates. These adverse conditions typically weaken all but the strongest trees, making them vulnerable to insects, fungi, parasitic plants, and diseases. More important, because of the long-term resource investment and land and labor commitment in forestry, high survival rates of good quality trees is a must. In agriculture, farmers can recoup their loses after a poor season, or even two. Trees, however, occupy a site for years. Therefore, any reduction in growth or quality from planting inferior stock represents a lost opportunity, which can be measured in time and capital, for as long as a tree occupies a particular site. Higher product yields For the second benefit, economic return, the investment in selection will be more than compensated for by higher product yields over shorter rotations. Better yields result in more building materials, higher fruit production and quality, faster fuelwood growth, and quicker and more prolific regrowth after lopping. Simple measures are most effective Effective seed selection can create success, even though sophisticated techniques may not be used. Any attention given to seed source will be a measured improvement over current practices. In addition, careful seed handling practices must be included as part of the seed collection program. Such practices include transport, seed preparation, handling, cleaning, grading, and seed testing. Disregarding these practices will result in damaged seed or allow the inclusion of unwanted or excessive amounts of foreign materials, which may hinder germination and plant production. The following sections in this bulletin describe how to develop a system of proper seed collection and handling practices. Where to get started Planning the seed collection strategy Too often in large planting programs the task of seed collection is an afterthought, typically left until the last minute and done hurriedly by unskilled or untrained labor while final nursery preparations are being made. Small-scale planters usually have access to left-over seeds from large programs. In either case, little consideration is given to seed quality, form, or location of the parent stock. Sometimes, to satisfy the requisite seed volume, nursery managers purchase bulked seed from villagers. However, villagers tend to collect from the nearest trees or stands, which generally include immature, diseased, distressed and otherwise inferior seed. And, if seeds need to be collected from the crown, villagers will choose the easy-to-climb trees, which are typically small and misshapen. Such trees would not normally be chosen as prime seed source candidates. Also, in some species a single tree will produce a large amount of seed in some years. Such a harvest may satisfy the bulk requirement, but would be genetically dangerous because only one phenotype is represented. This technique causes problems for both large- and small-scale planters. Careful planning avoids wasted time, effort Either approach, using untrained labor or collecting seed from a single tree, can be a critical mistake. Such practices often result in low survival, substandard trees, and a poor economic return for the time and work invested, for example, nursery and site preparation costs. Instead of an impromptu search or purchase from unknown sources, any seed collection, both large-scale and small-scale, should be a developed program of scheduled activities overseen by knowledgeable individuals. This is especially true for those involved in large-scale planting programs. Those involved in small-scale plantings can often request advice from nearby large-scale planters. These essential activities include selection of preferable parent trees; preparation of equipment including provisions for handling, transport, extraction, testing, grading, and storage; recruitment and training of workers and; seed sampling and quality monitoring. A timeline and workplan for the collection itself must be developed in conjunction with overall nursery operations. More important of these is the selection of preferable parent stock. This can be accomplished by an able person who can distinguish between desired and inferior seed sources. This person, in turn, can supervise field collection crews during harvest. Incorporating many of these activities often requires the level of funding available to large-scale operations. Nevertheless, even the small-scale planter should apply the principles as best possible whenever collecting seed. "The choice of seed source is one of the most important decisions faced by the forest manager. An error in judgment can lead to crops with poor stem and branch form or prone to pests and diseases. Within the genetic constitution of the seed is the potential for either good or poor tree growth, and since even small increases in growth rate or improved timber quality can lead to a much enhanced return on investment, the advantages of using the best available seed from which to grow the planting stock are considerable." Hibberd, P.G. (Forestry Commission Handbook 6: Forestry Practice) HMSO London, 1991. Genetics provides the basis for seed selection Why is it necessary to collect only from certain preferable trees? Tree improvement programs worldwide have shown that seed collected from trees with particular traits tends to produce trees with similar traits. One can correctly assume that if good parent trees are selected, then most of the resultant offspring will be of desirable quality. Yet despite this concept's proven value and wide understanding, it is seldom applied in the field. To correct this shortcoming, simple parent tree selection guidelines should be developed. These would identify the desired traits and specify the parent trees that reflect those traits. Such traits might include straight trunks, fast growth, and better form. These guidelines are normally met in national or company research programs, but following them will benefit all planters who are careful about the source of their seeds. The traits in turn are chosen to reflect the ultimate desired use of the tree, including building materials, windbreaks, shade, fuelwood, or erosion control. At the same time, these guidelines should not be made cumbersome. For the benefit of those individuals collecting seeds, the guidelines could be a condensed set of simple criteria. Indeed, immediate benefits can be derived from using even the most basic concepts, such as selecting trees of good form and vigor and avoiding trees that are poorly developed, diseased, dying, or are isolated from others of the same species. These simple methods should be applied to large and small programs. Collection strategy includes area, number, and spacing. While it is important to collect seed from the best parent trees it is also important to gather seed from several parent trees. Collecting seed from several parent trees assures a diversity among seedlings being planted. Whether the program is large or small, maintaining diversity is important and will help guard against pest epidemics. To obtain adequate diversity, seedlots should be collected from a number of trees within a species' range. Researchers have yet to determine an ideal number of trees per seedlot. In plantations and along roads more emphasis should be placed on collecting from the best trees. In all cases care should be taken to collect seed from several trees representative of the best parent stock. Researchers have yet to determine an ideal number of trees per seedlot, i.e., those seeds that will be used in one planting. However, most agree that collection should not rely on only one or two individual trees. According to some sources, a minimum of 15 to 25 mother trees per bulked seed source is preferred. Furthermore, collection should cover a broad geography, including the environmental extremes at the edge of the range. Seed selected from a narrow sampling of trees should be avoided as this will limit genetic diversity. Keeping a proper distance between selected parent trees is also vital. During natural regeneration of some species, seeds fall near the parent stock. In time, inbreeding may occur, which will result in lower quality individuals. To reduce the chance of collecting a seedlot predominated by half-siblings, a 100-meter distance between collection trees of the same species is recommended. This practice is especially critical to species that are lopped or coppiced as a method of harvest and regeneration. The temptation to forego a minimum number and spacing strategy is perhaps greatest during years of abundant seed production. Here, a large seed quantities are available from relatively few trees. At such times, an even greater effort should be made to ensure genetic variety. Even better, abundant seed years can be opportune. When properly cleaned and prepared, seeds can be stored for several years. Stored volumes of good seed will help ensure supplies during leaner production cycles. Where possible, all large-scale planting programs should have at least two years' seed supply in storage. Conversely, leaner seed years present other challenges. During such years shortfalls will occur and the urge will be to collect for quantity, without regard to quality. If at all possible, seed collection during lean production years should be minimized. Proper scheduling is vital to quality Aside from genetic and site qualities, other considerations must be factored into the collection strategy. For instance, only mature seed from ripened fruits should be gathered. Harvest schedules must account for the different times at which fruits from various species ripen. Depending on species, maturation can last between two to six months. To help determine ripening, periodic surveys of the selected stands is suggested. Surveys should begin after flowering, as is the practice with cocoa. To prevent any false readings, specific sample trees should be marked and used throughout the process. The surveys will also serve as an early indication of the season's expected seed volume and quality. In addition, field surveyors can detect early infestations of insects, disease, or other seed predators. With such information, the harvesting strategy and schedules can be adjusted to accommodate any foreseen hindrances. Take note of growing sites Aside from desired end-use traits, the tree must adapt to its growing site. In particular, it must withstand periodic harsh conditions, such as drought, and be able to grow in poor soils. Physical traits alone may yield few clues as to site adaptability. Here, environmental distinctions may help. The collection staff should note even the slightest variation throughout a species' range. Topography, soils, microclimate, associated vegetation, and man-caused factors such as perennial grazing may all influence how a species conforms to its surroundings. In overall location, a species typically grows best in the middle of its range and fares less well at the edges. However, seedlots should reflect all site variations, thus assuring that no one habitat is relied on too heavily. But some cautions are needed when sampling for habitat. When associated plants are used as site indicator species, one must discern between natural conditions and man-made alterations. For example, continual grazing can heavily degrade a site, even to the point where it changes the vegetative makeup. In addition, extreme dry or wet areas should be excluded if not within the normal bounds of a species' requirements. During collection of particular stands, efforts should concentrate on trees that comprise the stand's perimeter. These individuals produce better quality seed. Aside from natural areas, man-made stands should be reviewed carefully before selection as a seed source. For example, early reforestation efforts may have given little thought to seed collection, thus producing inferior parent trees to those found in natural stands. Or, the species planted on the site may not be well suited for the area. Whenever possible, historical data or records should be referred to for such stands. A short list of collection tactics - Collect seedlots from between 15 and 25 individuals that are spaced at least 100 meters distance from any other collection tree of the same species. - Choose trees in vigorous health and avoid any that are diseased, suppressed, deformed, environmentally stressed, or in otherwise poor health. - Collect from trees that are well formed and either dominant or co-dominant in the canopy. - Avoid individuals that are isolated from others of the same species. - Harvest only mature seed from ripened fruits. - To ensure genetic variation, collect fruits equally from all parts of the crown--top, sides, and bottom--as these parts may have been pollinated at varying times from different sources. - Collect throughout a species' normal habitat, noting variations in site. - Man-made stands, including live fencing, plantations, or windbreaks, should be carefully reviewed as to their establishment before being selected as a seed source. A field strategy. How to select good trees Parent tree selection in the field is best done as a planned team effort coordinated by a trained person. This selection of preferred trees serves to eliminate errors that would otherwise be produced by last-minute collection efforts. In addition, a planned, timely program allows for the full use of available people and resources. Development of the collection strategy includes a series routine screenings of potential parent stock. The series is broken into three progressive phases. Phase one is done well before the onset of flowering. Given simple guidelines for site selection and appearance, general laborers search for appropriate stands. Locations of such are recorded, along with general descriptive information. Phase two involves technical staff. Here, the identified stands are reviewed for their potential as a seed source. The review includes analysis of the site makeup including soils and topography, species composition, volume and spacing, and age, size and health of the trees. Initial selections are made as to potential parent stock. These trees are marked for further study in phase three. In phase three, trained professionals examine the marked individuals for a final selection. The trees are analyzed for their physical characteristics, including their form, branching, growth rate, dominance, crown cover, health, and any clues as to their seed productive capabilities. Before the final candidates are chosen, additional criteria are again considered. This includes the previous mentioned spacing preference of at least 100 meters between individuals of the same species. And, preference will be given to those trees located in the stand's perimeter. Finally, selected trees are marked and their location noted. Monitoring will increase as flowering begins and continue through the seed harvest period. Monitoring includes volume and quality of the seed as it matures, in addition to any indications of pest infestations including insects and disease. Seed handling and preparation Seeds are rarely taken directly from the collection site for immediate planting in the nursery. Instead, they must first undergo a preparation that will ensure proper germination and help eliminate bad or damaged seed. Preparation includes all activities from collection to sowing. These activities cover transport, sorting, extracting, cleaning, testing, and grading. In addition, seed harvesting and sowing periods are often months apart, which requires adequate storage facilities. The facilities must protect the seed stock from the weather and intrusive pests such as animals, insects or molds. In some instances, proper temperature control may also be required. This is especially true if seed is to be kept over a number of years. Handling in the field Once the fruits are picked or collected, they must be transported directly for seed processing. Any lag time in the field could cause desiccation or predation by various seed pests. The seeds must also be well-protected from the weather to prevent excessive contact with moisture, which may prompt early germination. In addition, because of the variation in harvested fruits, handling techniques must flexible. Those in charge of collection must have adequate knowledge as to each species' requirements and limitations during transport. For example, while the hard coated seeds of most leguminous species travel well, other seeds are more fragile and require greater handling care. Proper conditioning limits seed degradation The nursery manager must have facilities readied for seed preparation at the time of collection. Such facilities should be located at the nursery site, thus eliminating the need for further transport before sowing. Seed extraction should occur as the fruits arrive from the field. Again, any lag between collection and preparation will cause the seed to degrade or spoil. Depending on species, equipment for both dry and moist extraction may be needed. Dry extraction requires appropriate sorting and drying areas, tumblers, and screens for sieving. Moist extraction calls for a method of macerating the fleshy fruits, followed by drying and cleaning of any remaining foreign materials. In either case, all inert materials must be removed as these can result in poor germination or hamper storage ability. Also, the rate of drying and moisture content must be carefully monitored during the drying process. Seeds dried too quickly may become damaged. While small-scale planters may not have access to sophisticated equipment for drying and cleaning seeds, they should aim to remove as much foreign material as possible. After extraction, the pure seed is then graded. Grading helps ensure a more homogenous seed set, which in turn will produce more uniform growth in the nursery. Grading is done either by seed size, weight, or a combination of both. Actual seed size within the same species will vary due to a number of factors. The goal is to eliminate undersized, immature, or deformed seed. This usually can be done by hand if great quantities are not required. However, graders must be provided samples of the desired well-graded product to use as a guide. In addition to grading, seeds are tested for germination rates, and are examined for phytosanitary concerns and species purity. Using these factors, the forester must develop criteria for consistent seed certification. No matter how carefully done, collection efforts in the field will be nullified if inconsistent methods of grading and testing are used from one seed lot to the next. Proper storage is essential If the prepared seed is not used within a reasonable amount of time, adequate storage must be provided. As noted, most leguminous seeds store well in normal conditions, provided they are properly cleaned, dried, and protected. Such prepared, intact seed can be handled and stored without fear of damage. However, if storage is required for several years, special facilities, such as cold storage, may be needed for some species. On the other hand, if germination begins, different measures must be taken. Here, the seed ceases dormancy and begins to use stored nutrients for survival. At this point, its shelf life is drastically reduced. Thus, it is important to closely observe the condition of the stored seed and monitor it periodically to ensure the storage environment remains intact. Why collect seed from several provinces? Differences in how trees adapt to environments is often more important with a species than among species. There can be important differences in growth between seed sources from different geographical areas and environments. The areas and environments in which stands have developed through natural selection are call provenances. The growth, measured in height, in tropical hardwoods of the most vigorous provenances can be 30 to 50 percent greater than the growth in the least vigorous provenances. Unfortunately, there are very few tree species that have been adequately explored in their center of origin and studied in provenance and progeny tests on multiple sites, leaving much uncertainty about provenances which are intended to represent an entire species. Perhaps the most striking example of this comes form the use of Acacia mangium in Sabah, Malaysia, where ultimately thousands of hectares were planted from seed collected from one tree. As a result, growth rates of third generation were one-half those of the first generation. This bulletin was originally published by The World Bank/AGRNR. by Norman Jones 1 Bradfield Avenue, BRIDGEND, Mid-Glam CF31 4HL, United Kingdom Tel [44 16560] 656726; Fax [44 1656] 768369;
The cerebellum is located in the lower part of the brain, towards the back. This part of the brain plays a role in body movement, eye movement, and balance. A cerebellar stroke occurs when the brain’s blood supply to this area is interrupted. Without blood, the brain tissue quickly dies. This results in the loss of certain functions. A stroke is a serious condition that needs emergency care. Copyright © Nucleus Medical Media, Inc. There are two main types of stroke ischemic and hemorrhagic. An ischemic stroke is the most common type of stroke. An ischemic stroke is caused by a blockage of the blood flow, which may be due to: - A clot from another part of the body like the heart or neck. The clot breaks off and flows through the blood until it becomes trapped in a blood vessel supplying the brain. - A clot that forms in an artery that supplies blood to the brain. - A tear in an artery supplying blood to the brain. Called an arterial dissection. A hemorrhagic stroke is caused by a burst blood vessel. Blood spills out of the broken blood vessel and pools in the brain. This interupts the flow of blood and causes a build up of pressure on the brain. Last reviewedDecember 2013by Rimas Lukas, MD Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Growing Up With Hearing Loss Signs of Hearing Loss Read this page to learn about some signs of hearing loss. As your child grows, does something seem wrong with her hearing? - Sleep soundly even when you talk loudly near her? - Not babble anymore (after 9 months)? Signs of normal hearing If you think your child has a hearing loss, talk to your doctor. Also, read this timeline of normal things most hearing babies do. Just remember, all children are different. They may not do all of these things on time: From birth to 3 months: - React to loud noises - Wake up at loud sounds - Be soothed by the sound of your voice - Start making sounds in the back of her throat, like going "goo" From 3 to 6 months: - React to the sound of your voice - Start turning her head or eyes towards sounds - Like playing with toys that make noise - Stop to listen to voices - Smile when someone talks to her - Cry in different ways when she needs different things - such as if she's hungry, or needs to be changed. From 6 to 12 months: - Answer to her name - Make many different baby talk sounds - Start to understand simple words, like "mama," "dada," and "wave bye-bye" - Turn her head to familiar sounds, like a telephone ringing - React to changes in your tone of voice By 12 months: - Copy sounds that she hears - Answer simple questions like, "Where's the ball?" - Recognize her name - Understand what "no" means From 12 to 18 months: - Give you a toy when you ask her - Point to parts of the body when you ask her - Put sounds together - Use a few simple words, like "mama," "more," and "no." - Follow simple directions that you tell her By 18 months: - Understand about 50 words By 2 years: - Understand yes and no questions - Use words that you often use at home or school - Make simple sentences - Follow simple orders without being shown what to do By 2 ½ years: - Use about 270 words - Say or sing short rhymes and songs - Check out interesting sounds, or tell others about them By 3 years: - Make simple sentences of 3 to 4 words - Use about 1,000 words - Be able to tell a story - Know her name and the names of people in her family - Sing songs
When reading a story, students may be asked to identify the lesson. (CCSS 1.RL.2, 2.RL.2, 3.RL.2) In this download, you will find an anchor mat that can be used during initial instruction to explore what a lesson is. As a formative assessment piece, students can complete the anchor mat independently to monitor if understanding is being maintained. Also included in this download is an organizer that students can fill out while reading a story independently. After they identify the lesson of a story, students can add text evidence that can be used to support their thinking. Students also can complete this organizer with a partner. Some of the images on these pages are in color, but the pages can be printed in grayscale to save ink. Or students can put the pages into a plastic sleeve and use a wipe-off marker to respond. Or using a document camera, the pages can be projected onto a whiteboard. Students can respond on sticky notes and then add their sticky notes to each section. Students then can compare their ideas. Recycle the skill throughout the year. Vary the level of scaffolding needed based on student readiness levels. Check out the preview!
\|Although it measures only 110 miles from the north to south and 200 from east to west, Bhutan - called by its people Druk Yul, "the Land of the Thunder Dragon" -- is home to a remarkable variety of climates and ecosystems. Essentially, the country is divided into three major land regions: plains and river valleys in the south; a mid-Himalayan (5,000 to 14,000 ft. high) area north of the valleys; and the mountainous lands in the Himalayas, which range from 14,000 to 24,000 ft. above sea level. A Wealth of Life: The Himalayas In particular, the Himalayas are noteworthy for their biological richness. Since the Himalayas' geologically recent origin less than 25 million years ago, they have molded the region's fauna and flora by limiting Indian species from moving northward, and Tibetan species from moving southward. Because of its youthfulness, the Himalaya has not yet evolved plant and animal life uniquely adapted to its terrain; flora and fauna are instead an amalgam of forms native to India, Southeast Asia, the Mediterranean and Europe. Himalayan rivers were in place before the mountains were, and consequently, the river courses have remained unchanged while they have cut ever deeper gorges and valleys. These valleys have provided the main avenues of contact between Indian and Eurasian wildlife. Animals adapted to cold climes, such as wolves, brown bears and rose finches, moved south from Eurasia, while tropical species moved north into the foothills, eventually meeting in the high mountains. The main Himalaya, stretching for 1,900 miles and varying in width from 50 to nearly 200 miles, really consists of three parallel ranges: the low hills of the Outer Himalaya that do not exceed 3,000 feet; the Middle Himalaya, whose peaks vary in height from 6,000-14,000 feet. This zone supports extensive and magnificent forests of conifers, oaks, maples, laurels and magnolias that are now almost totally unique to Bhutan, not having suffered the mass-deforestation of other Himalayan countries. The Inner Himalaya is distinguished by its snow and ice clad peaks. These peaks border plateaus, and in turn form the southern edge of Tibet. Tibet, a vast area of plains, mountains and gorges, is only now being explored fully by naturalists. Tropical heat and Arctic cold are telescoped into a span of little more than 40 miles in Bhutan. The entire region boasts a richness and variety of plants and wildlife that are perhaps unequalled in the world. Botanists have estimated that at least 6,500 species of flowering plants grow in Nepal alone. Bhutan, far less explored and catalogued, is acknowledged as having more. A new order of amphibians was discovered in Nepal in the early 1970s, one can only wonder at what awaits discovery amidst the forest clad hills of Bhutan.
Students will explore the shape of a circle with bubbles, Terry Winters’s painting Rhyme, and a project of their own. They will identify the different colors in Rhyme, decorate circles with similar colors, and arrange smaller circles on a larger circle template, mimicking elements of Winters’s painting. Intended Age GroupEarly childhood (ages 3-5) Length of LessonOne 40 minute lesson Standards AreaVisual Arts Students will be able to: - recognize the shape of a circle in various objects; - identify shapes and colors in Winters’s painting; - count the number of circles in Winters’s painting and in their own project; and - arrange smaller circles inside a larger circle template. - Warm-up: Blow some bubbles for the children and allow them to pop the bubbles and have some silly time. Ask students what shape the bubbles make. Help the children take turns blowing bubbles as well (they’ll love it!). - Show the students Rhyme and ask what colors they see. What shapes do they see? Counting out loud with the students, find the number of small circles inside one large circle (the number of small circles differs but there should be around eight or nine per large circle). - Distribute a Circles handout to each student and give them time to color the smaller circles with the same colors Winters used—pink, red, black, grey, blue, yellow, etc. - If your students are comfortable with scissors, let them cut out all of the circles on the handout. Help younger students cut out their circles. - Invite the students to arrange their smaller circles on the larger circle, just like Winters put smaller circles in his larger circles! How many little circles can they fit on their larger circle? Have the students count their circles out loud to a partner. - At least one bottle of bubbles with a bubble wand (you can get as fancy as you want here!) - Colored pencils, markers, or crayons - About the Art section on Rhyme - One color copy of the painting for every four students, or the ability to project the image onto a wall or screen - Circles handout - Visual Arts - Invent and Discover to Create - Observe and Learn to Comprehend - Relate and Connect to Transfer - Language Arts - Oral Expression and Listening 21st Century Skills - Critical Thinking & Reasoning - Information Literacy About the Art Who Made It? Terry Winters was born in Brooklyn, New York, in 1949. He has a keen interest in science and scientific breakthroughs and is knowledgeable about computer simulations, genetic mapping, and electronic microscopes. Winters’ enthusiasm for science manifests itself in his art, as he often finds inspiration for his paintings in the biological forms found in nature. He has researched the sources of ancient pigments used to create color in paints and dyes, and he has even ground pigments to make his own paints. In effect, he has stretched the creative act to include making the very materials with which his art is created. Winters spent ten years focused almost solely on developing his approach to painting, postponing any exhibiting of his artwork until he had worked out his own relationship to the creative task. What Inspired It? “I’m interested in how to give a picture of these things we can’t see,” says Winters. Rhyme has endless possibilities for interpretations, as Winters’ paintings draw from a variety of sources at once. His early sketches of plant parts—like pods, spores, and stamens—that he found in natural history museums and books became the starting point for the subject matter of his paintings. Images of hot air balloons, soccer balls, sponges, and soap bubbles fill his sketch books and lend qualities to the forms he creates. Yet despite the real-world origin of his imagery, Winters doesn’t aim to represent specific processes or structures through his paintings. Ideas that are rooted in biology and chemistry take on a life of their own when they reach the canvas. Winters is also interested in the forces of the natural world that fall outside human perception. At any given moment there are several—perhaps innumerable—forces at work that extend beyond the realm of what we can perceive. We cannot hear sounds that fall outside a certain range, see light at certain wavelengths, or distinguish molecular interactions with the naked eye, yet we experience the effects of these interactions and conditions. These indefinable, imperceptible, but nonetheless existing occurrences are the kinds of things Winters tries to depict in his paintings. You can see two distinct groupings of circular shapes in this painting. Each circular shape is made of smaller cell-like clusters which enclose even more circular forms. What might these groupings of circles mimic? Soap bubbles? Insect eyes? The black circular forms in the lower left portion of the painting appear to be incomplete and seem to mimic the two more defined circular groupings. There is also another vague cluster of circles outlined in yellow paint. Just as the forms in Rhyme might evoke the building blocks of life, these incomplete shapes might suggest the building blocks of Winters’ creative process. You can see evidence of Winters’ gestures, particularly in the upper left-hand corner of the painting. Notice how the dark brown background lightens and blurs into the lower left portion of the surface. For Winters, titles are an essential part of the creation and experience of his paintings. Like his forms, his titles do not link his paintings to the real world in any linear or logical way. As he works on a given painting, verbal associations arise in his mind, and in turn, influence the evolution of the painting.
- CLASS: Mammalia (Mammals) - ORDER: Carnivora - FAMILY: Felidae - GENUS: Panthera - SPECIES: uncia Living at the top of the world: Legendary snow leopards are rarely seen in the wild, as they live high in the mountains of Central Asia. Although the cats freely cross the international boundaries of 12 countries, their secretive behavior and remote habitat among the highest mountains in the world add to their mystery. Because of their shy behavior and uncanny, almost mystical ability to disappear among the rocks, snow leopards have entered the folklore of local peoples in many countries and have been described as shape-changing mountain spirits. Snow leopards are almost impossible to locate and study in the wild because they blend in with their surroundings so well. Add the extreme conditions of cold and steep terrain, often beyond the limits of human endurance, and it is extremely difficult to radio tag snow leopards for research purposes. Smoky gray and blurred black markings on a pale gray or cream-colored background provide the snow leopard with superb camouflage in the mountains. These “spots” are arranged in distinct rows and get paler in the winter. No wonder this medium-sized cat has been called the ghost cat of the Himalayas! Snow leopards have dense fur not found on cats in warmer climates. They move to different altitudes along with the summer and winter migrations of their prey animals, so their coats vary from fine in the summer to thick in the winter. HABITAT AND DIET A unique cat in an extreme habitat: So how do snow leopards live at high altitudes? They keep mainly to cliffs and rocky slopes, below the permanent snow line. Snow leopards have a relatively small head with a short, broad nose that has a large nasal cavity that passes cold air through and warms it. Their huge paws have fur on the bottom that protects and cushions their feet for walking, climbing, and jumping. The wide, furry paws also give the cat great traction on snow. Short, well-developed front legs and chest muscles help with balance when climbing. The snow leopard's incredibly long, thick, and beautiful tail also helps with balance and is sometimes as long as the cat's body! Most active at dawn and dusk, snow leopards are powerful predators capable of killing prey two to three times their own weight. Recent radio-tracking data shows they bring down prey every 10 to 15 days. Blue sheep and ibex are their main food, along with marmots, game birds, small rodents, and livestock. Snow leopards stalk their prey, then spring and grab onto it. Problems arise in the winter, when marmots are hibernating and snow leopards turn to livestock for food. This brings them into conflict with herders and farmers. And as marmots are hunted for their pelts and meat or killed as pests by farmers, snow leopards must hunt livestock more often. This creates the cycle that puts snow leopards in direct competition with people. At the San Diego Zoo, our snow leopards are fed a ground meat product made for zoo carnivores most days, large bones two times per week, and a thawed rabbit once a week. Living in such rocky terrain, it isn't easy for snow leopards to find one another. Typically solitary and nomadic, the cats advertise their presence by leaving distinct signals along their travel routes, scent marking and claw raking on boulders and tree trunks. Sometimes they deposit urine and/or feces samples in scraped soil depressions as messages. Even cheek rubbing can spread scent, so all of these smell "advertisements" can remain for days and weeks to mark off ranges. Like other larger cats, snow leopards hiss, growl, moan, and yowl, but they do not roar, as their throat is similar to that of the smaller cats; instead, snow leopards make a friendly chuff and can purr, too. When breeding season arrives, January through late March, snow leopards send vocal messages to pair up. After breeding, the male goes off, and the female is responsible for finding a safe place to have and rear her cubs, most likely a nest among the rocks (only recently, through the use of GPS technology, has a den with cubs been located). Usually two or three cubs are born to a litter in June or July. The cubs are much darker than their mother, and their eyes open when they are about seven days old. By two months old, they can run and eat solid food. At three months of age, the youngsters are ready to learn how to hunt for that food. Youngsters usually leave the mother at 18 to 22 months, reaching sexual maturity at 2 to 3 years of age. AT THE ZOO Our first snow leopards arrived from the wild on January 21, 1949, a day when San Diego also received its first snow in 99 years! Over the years, we’ve had more snow leopards, and 13 cubs have been born here. Today, our snow leopards live in a naturalistic setting of rocky outcroppings and ledges. For enrichment, scent sprays and lotions are placed on boulders, logs, and ground cover. The cats are not picky and enjoy any new scent offered. Bones and treats placed in challenging areas encourage exercise. These daily enrichment items help stimulate the snow leopards' natural behaviors. They don't play with "toys," but they like manipulating and smashing gourds when no one is looking! No one knows for sure how many snow leopards remain in the wild, due to their elusive nature and challenging (for humans!) habitat, but it is estimated that there are no more than 4,000 to 6,500 of the ghost cats over their entire range. Historically, habitat remoteness served to protect snow leopards from humans, particularly conflicts with herders and farmers. Indeed, there are no known snow leopard attacks on humans, as the cats would rather run away than fight. But with human encroachment into the high mountain ranges comes competition for living space and food. The snow leopard’s beautiful coat has also been its undoing, as they have been hunted for their fur until their numbers became severely reduced. Many countries have banned the import of snow leopard fur, but the trade persists, primarily because of human poverty. And although snow leopards are listed as an endangered species, they continue to be hunted for their bones and organs, too, which are used in traditional Asian medicines. Mining activities also continue to degrade habitat, forcing snow leopards and their prey to move into less suitable areas where they can come into conflict with human efforts to survive in the harsh mountain habitats. Cooperation between governments, conservation agencies, and the general public is essential. If the farmer and herder's quality of life can be improved through better management of grazing lands, payment for livestock preyed upon by the cats, and more health care and education services, then we have a chance to protect snow leopards and other wildlife in the region. The Snow Leopard Trust, based in Seattle, is a nonprofit organization dedicated to the conservation of snow leopards. The Trust believes the cats can be helped through a balanced approach that considers the needs of local people and the environment and includes education programs, training, and support for park and reserve staff in various countries. There are now more than 100 protected areas for snow leopards, 36 of which are found on international borders. San Diego Zoo Global takes part in the Association of Zoos and Aquariums’ Species Survival Plan for snow leopards and provides direct support to the Snow Leopard Trust.
Rounding Mixed Numbers Worksheets - Math > - Pre-Algebra > - Fractions > - Rounding > - Mixed Numbers Put your super-promising math genius to play with our free worksheets on rounding mixed numbers to the nearest whole numbers. These printables offer rounding exercises for mixed numbers consisting of a whole number and a fraction part. Students must check whether the fraction part is greater than or equal to 1/2. If yes, the rounded number is the next whole number after the one in the given mixed number. If not, the answer is only the whole number part of the given number. Our pdf worksheets on rounding mixed numbers to the nearest whole numbers are ideal for 4th grade and 5th grade kids.
The International Space Station is no longer the only place where humans can live in orbit. On Nov. 29, 2022, the Shenzhou 15 mission launched from China’s Gobi Desert carrying three taikonauts – the Chinese word for astronauts. Six hours later, they reached their destination, China’s recently completed space station, called Tiangong, which means “heavenly palace” in Mandarin. The three taikonauts replaced the existing crew that helped wrap up construction. With this successful mission, China has become just the third nation to operate a permanent space station. China’s space station is an achievement that solidifies the country’s position alongside the U.S. and Russia as one of the world’s top three space powers. As scholars of space law and space policy who lead the Indiana University Ostrom Workshop’s Space Governance Program, we have been following the development of the Chinese space station with interest. Unlike the collaborative, U.S.-led International Space Station, Tiangong is entirely built and run by China. The successful opening of the station is the beginning of some exciting science. But the station also highlights the country’s policy of self-reliance and is an important step for China toward achieving larger space ambitions among a changing landscape of power dynamics in space. Capabilities of a Chinese station The Tiangong space station is the culmination of three decades of work on the Chinese manned space program. The station is 180 feet (55 meters) long and is comprised of three modules that were launched separately and connected in space. These include one core module where a maximum of six taikonauts can live and two experiment modules for a total of 3,884 cubic feet (110 cubic meters) of space, about one-fifth the size of the International Space Station. The station also has an external robotic arm, which can support activities and experiments outside the station, and three docking ports for resupply vehicles and manned spacecraft. Like China’s aircraft carriers and other spacecraft, Tiangong is based on a Soviet-era design – it is pretty much a copy of the Soviet Mir space station from the 1980s. But the Tiangong station has been heavily modernized and improved. The Chinese space station is slated to stay in orbit for 15 years, with plans to send two six-month crewed missions and two cargo missions to it annually. The science experiments have already begun, with a planned study involving monkey reproduction commencing in the station’s biological test cabinets. Whether the monkeys will cooperate is an entirely different matter. Science and a steppingstone The main function of the Tiangong station is to perform research on life in space. There is a particular focus on learning about the growth and development of different types of plants, animals and microorganisms, and there are more than 1,000 experiments planned for the next 10 years. Tiangong is strictly Chinese made and managed, but China has an open invitation for other nations to collaborate on experiments aboard Tiangong. So far, nine projects from 17 countries have been selected. Although the new station is small compared to the 16 modules of the International Space Station, Tiangong and the science done aboard will help support China’s future space missions. In December 2023, China is planning to launch a new space telescope called Xuntian. This telescope will map stars and supermassive black holes among other projects with a resolution about the same as the Hubble Space Telescope but with a wider view. The telescope will periodically dock with the station for maintenance. China also has plans to launch multiple missions to Mars and nearby comets and asteroids with the goal of bringing samples back to Earth. And perhaps most notably, China has announced plans to build a joint Moon base with Russia – though no timeline for this mission has been set. A new era in space is unfolding. The Tiangong station is beginning its life just as the International Space Station, after more than 30 years in orbit, is set to be decommissioned by 2030. The International Space Station is the classic example of collaborative ideals in space – even at the height of the Cold War, the U.S. and the Soviet Union came together to develop and launch the beginnings of the space station in the early 1990s. By comparison, China and the U.S. have not been so jovial in their orbital dealings. In the 1990s, when China was still launching U.S. satellites into orbit, concerns emerged that China was accidentally acquiring – or stealing – U.S. technology. These concern in part led to the Wolf Amendment, passed by Congress in 2011, which prohibits NASA from collaborating with China in any capacity. China’s space program was not mature enough to be part of the construction of the International Space Station in the 1990s and early 2000s. By the time China had the ability to contribute to the International Space Station, the Wolf Amendment prevented it from doing so. It remains to be seen how the map of space collaboration will change in the coming years. The U.S.-led Artemis Program that aims to build a self-sustaining habitat on the Moon is open to all nations, and 19 countries have joined as partners so far. China has also recently opened its joint Moon mission with Russia to other nations. This was partly driven by cooling Chinese-Russian relations but also due to the fact that because of the war in Ukraine, Sweden, France and the European Space Agency canceled planned missions with Russia. As tensions on Earth rise between China, Russia and the West, and some of that jockeying spills over into space, it remains to be seen how the decommissioning of the International Space Station and operation of the Tiangong station will influence the China-U.S. relationship. An event like the famous handshake between U.S. astronauts and Russian cosmonauts while orbiting Earth in 1975 is a long way off, but collaboration between the U.S. and China could do much to cool tensions on and above the Earth.
The final source of Biblical Preaching is imagination. Charles Koller notes that imagination alone can turn a dull sermon into one that comes alive. Imagination helps you create connections between the past and the present in interesting ways. Koller notes that while it is powerful, one should take pains not to abuse it with attempts to be clever. In addtion, any conjectures or additions to the text should be identified as such to the people. Expression of Imagination Koller notes that imagination is expressed in a few ways: - Visualization – This is the portrayal of insicdents in a dramatic way. You can often find details in the text which people often overlook. One might look at our series on preaching with stories. - Supposition – Here you create a incident to illustrate the point rather than attempting to find a true one. Once again, Koller says that we must make clear to the people what we are doing. - Parable – Jesus used this very frequently. Koller notes that we must be sure to make clear the difference between facts and fiction. - Figures of Speech – Koller notes a few of these that we can make better use of. Simile Here you make a comparison using the imagination. Instead of the Hudson River is like the Rhine you could say the Hudson Rivers flows like the march of time. Analogy this is an extended simile that looks at the resemblance between the things. Metaphor Here you say something is the thing that it is compared to. So we are the salt of the earth. We are not literally salt, but we have characteristics of it. Personification – This is an interesting one. Here you apply characteristics of humanity to objects that are not a part of the human family. For example when the “stones cry out.” Preachers must use their imaginations in sermons. God has called us to worship him with our whole being, certainly it includes the imagination. I agree that merely appealing to it will make any sermon more effective.
By Freeman ya Ngulu. A special type of light created using an ancient Namibian gemstone may be the key to a new light-based quantum computer that could solve a long-standing scientific mystery, in new research led by Britain’s University of St Andrews. It was discovered that there is In this study, it was discovered that naturally mined copper oxide (CuO) gemstones from Namibia could be used to create Rydberg polaritons, the largest hybrid particles of light and matter ever created. The Rydberg polariton is constantly switching from light to matter and vice versa. Light and matter are like two sides of the same coin, the Rydberg polariton, and the matter side causes the polaritons to interact with each other. This interaction is of great importance as it enables the development of quantum simulators, a class of quantum computers in which information is stored in qubits. Unlike binary bits in traditional computers, which can only be 0 or 1, qubits can take an infinite number of values between 0 and 1. As a result, it can store more information and run multiple processes at the same time. Investigating scientific mysteries: In a paper published in the journal Nature Materials, the researchers behind the discovery said the feature could help solve important mysteries in physics, chemistry and biology, such as how to make high-temperature superconductors for high-speed trains. He explains that it may be possible to solve it with a quantum simulator. , how to make cheap fertilizers that could solve global hunger, or how proteins fold to make it easier to produce more effective medicines. “Creating quantum simulators with light is the holy grail of science,” said project leader Hamid Ohadi in a press release. “By developing a key component, Rydberg his Polariton, we have taken a big step forward.” The researchers trapped light between two highly reflective mirrors to generate the Rydberg polariton using cuprous oxide crystals found in a Namibian quarry. A cuprous oxide crystal mined in Namibia was thinned and polished into a 30-micrometer slab before being sandwiched between two mirrors to produce a Rydberg polariton 100 times larger than previously demonstrated. rice field. Following this work, the team decided to further refine these methods to investigate the possibility of creating the next component of quantum simulators: quantum circuits. Cuprous oxide is a crystal mined from Namibia used to create the Rydberg Polariton. (Photo credit: University of St. Andrews).
What is Education and Examples? Education is a process of acquiring knowledge, skills, values, and attitudes through various formal and informal means. It is an essential tool that empowers individuals to lead a meaningful and productive life by providing them with the necessary tools and resources to succeed in various spheres of life. Education can take many forms, including formal education such as attending schools, colleges, and universities, as well as informal education such as learning through life experiences, reading, and online courses. It plays a crucial role in personal growth, career development, and social mobility, and can lead to higher levels of achievement, better employment opportunities, and a higher standard of living. There are various types of education, such as: Formal Education: Formal education is a structured form of education that takes place in schools, colleges, and universities. It provides students with a structured curriculum that covers various subjects, including math, science,
Mosquitos are known for their irritating bites and buzzing sound as they fly around. However, did you know that there is one species of mosquito that is much larger than the others? In this article, learn more about the largest mosquito in the world, including its size compared to other species, its habitat, and other interesting facts. Some Facts about the Giant Mosquito The biggest species of mosquito in the world is called the Nelson’s giant mosquito, also known as the Elephant mosquito. It is scientific name is Toxorhynchites nelsoni and it can grow to be up to 2.5 inches long. It is one of the largest members of the Culicidae family and is commonly found in the Neotropics, South Asia, and parts of Africa. How Big Is the Nelson’s Giant Mosquito? Nelson’s giant mosquito can measure up to 2.5 inches in length, which is substantially bigger than other mosquito species. These size variations are due to living in different parts of the world, with shorter mosquitoes being found in cooler areas and larger mosquitoes being found in warmer and more humid environments. The size of the Nelson’s giant mosquito usually ranges from 1 to 1.5 inches in length. Where Is the Nelson’s Giant Mosquito Found? Most mosquitoes tend to thrive in hot, humid tropical environments. The Nelson’s giant mosquito is no exception to this, as it is commonly found in the Neotropics, South Asia, and parts of Africa. This mosquito species can also survive in moist areas and thrive in semi-arid environments, so it is quite a versatile species. What Is the Difference between the Nelson’s Giant Mosquito and Other Mosquito Species? The Nelson’s giant mosquito is easily distinguishable from other species due to its large size. It is also different from other species of mosquitoes in that it does not transmit any kind of viruses or diseases. This is because the mosquito has adapted to drinking nectar from flowers and plants, which serves as its sustenance. What Are the Unique Characteristics of the Nelson’s Giant Mosquito? The Nelson’s giant mosquito has a few unique characteristics that make it a one of a kind mosquito species. One of its unique characteristics is its striking yellow and black stripes, which helps distinguish it from other mosquito species. It also has long, black legs and an elongated head, making it a signt to behold. People Also Ask Why Is the Nelson’s Giant Mosquito the Biggest Mosquito in the World? Nelson’s giant mosquito is the biggest mosquito in the world partly due to its large size and also because of its ability to survive in both hot and semi-arid environments. It also has adapted to feed on only nectar from flowers and plants, which helps it thrive in different kinds of climates. What Do Nelson’s Giant Mosquitoes Eat? Nelson’s giant mosquitoes mainly feed on nectar and pollen from flowers and plants. They do not feed on human blood, like other species do. This is why they are not known to transmit any kind of disease. Are Nelson’s Giant Mosquitoes Dangerous? No, Nelson’s giant mosquitoes are not dangerous as they do not transmit any kind of virus or disease. These mosquitoes mainly feed on nectar and pollen from flowers, so they are harmless to humans. Do Nelson’s Giant Mosquitoes Bite? Nelson’s giant mosquitoes are known to bite, but the bites are usually very mild and do not cause any lasting damage. These bites are not known to spread any kind of virus or disease. How Can I Prevent Nelson’s Giant Mosquitoes from Entering My Home? The best way to prevent Nelson’s giant mosquitoes from entering your home is by keeping the doors and windows screened and fixing any broken windows or screens. You should also ensure that standing water is removed from your outdoor areas and seal any cracks or crevices around your home. Nelson’s giant mosquito is one of the biggest species of mosquito in the world, measuring up to 2.5 inches in length. It is mainly found in the Neotropics, South Asia and parts of Africa. Unlike other mosquito species, the Nelson’s giant mosquito only drinks nectar and pollen from plants and flowers and they do not transmit any kind of virus or disease. Overall, it is interesting to learn more about this unique species of mosquito and its different characteristics.
Status: Not Listed The little brown bat varies in color from brown, reddish, to golden, although some albino specimens have been observed. Bats are grouped into the order Chiroptera, which means “hand wing.” This phrase refers to the fact that the wings of all bats are made up of a thin membrane stretched over elongated finger bones. On average, little brown bats weigh less than half an ounce and have a wingspan of 8 to 11 inches (20 to 28 centimeters). Females are typically larger than males. The little brown bat is found in abundance throughout the northern United States into Canada. It is present in lesser numbers in southern states and is absent from the southern Great Plains. Little brown bats also live in high-elevation forests in Mexico. Little brown bats are not territorial—they live in colonies numbering in the hundreds of thousands of individuals. Colonies aggregate at nesting sites called roosts. There are several different types of roosts that serve different purposes—day and night roosts provide habitat for bats when they are sleeping or resting. Hibernacula are a type of roost that is occupied in the winter months. Little brown bats choose buildings, caves, trees, rocks, and wood piles as roost sites. They may migrate hundreds of miles to get from their summer habitats to hibernacula. A variety of wild mammals, birds, and snakes will incorporate these bats into their diets, because the large colony sizes make them easy to catch. Domestic cats are a major predator of bats that roost near people. To locate their prey, most insect-eating bats use a system called echolocation. This supersense is similar to sonar used in ships. The bat emits a high frequency sound that bounces off objects in their environment. They can then determine the location and size of prey by listening to the sound echo that returns to them. Little brown bats are nocturnal and hunt most actively for a few hours after dusk. They must eat half their body weight in insects per night to prevent malnourishment. New mothers sometimes eat more than their own body weight in a single night. Eating insects plays an important role in the bats' ecosystem by controlling bug populations near their roost sites. Mating is random and promiscuous. Both males and females mate with more than one partner. As a prenup to mating, large swarms occur during late summer and fall. The mating season usually starts in August and pups are born approximately two months later. Once the young are born, they are dependent on their mother for food and warmth. At about one month of age, they can fly and catch insects on their own. Each mother has one pup a year and can identify her offspring based on scent and calls. Individuals usually live to six or seven years, although one 31-year-old little brown bat was found in the wild. Such a long lifespan is highly unusual for small mammals. The population of little brown bats is declining. They are one of many bat species suffering from white-nose syndrome, a fungal disease that affects hibernating bats and causes death. Little brown bats tend to go where people go, because many of the structures we build are suitable habitat for them. The bats can transmit parasites and occasionally rabies, so control measures have been used on them in some instances. Pesticide build-up, deforestation, and mining are also detrimental to little brown bats. Hibernation occurs over winter. During this time, the bats can withstand a temperature change of nearly 120 degrees Fahrenheit without suffering any damage. Five ways to participate in the 50th anniversary celebration!Read More Take the Clean Earth Challenge and help make the planet a happier, healthier place.Learn More Promoting more-inclusive outdoor experiences for allRead More A groundbreaking bipartisan bill aims to address the looming wildlife crisis before it's too late, while creating sorely needed jobs.Read More
DermNet provides Google Translate, a free machine translation service. Note that this may not provide an exact translation in all languages Author: Marie Hartley, Staff Writer, 2009. The bed bug, Cimex lectularius, is a blood-sucking human parasite that is found worldwide. Bed bugs come from the insect family Cimicidae. The bed bug is oval shaped, flat, reddish brown, and up to 5 mm long. Immature bed bugs are smaller than adults and may be translucent to light yellow. Bed bugs are attracted by warmth and generally feed at night. They can survive for long periods (e.g. up to one year) without feeding. In developed countries, bed bugs often hide in the cracks and crevices of mattresses, bed frames, and other nearby structures. They can travel in furniture, luggage, and clothing, or can migrate through holes in walls, water pipes, or gutters. In developing countries, bed bugs can be found in the cracks and crevices of the walls of mud houses, as well as thatched roofs. Reports of bed bug infestations appear to be increasing in homes, apartments, hotel rooms, hospitals, and hostels in developed countries. This may be due to increased international travel, immigration, and insecticide resistance. Bed bugs usually feed without detection by the host, although some people with bed bug infestations report a restless night's sleep. Bed bugs generally bite in a linear pattern (a line) on exposed areas of skin such as the face, neck, hand, and arms. Most patients do not experience a reaction to a bed bug bite, and the only evidence is a tiny punctum (hole) at the site of the bite. When a reaction occurs, the lesions are most commonly 2 to 5 mm red, itchy bumps. If they are not scratched they usually resolve in a week or so. Some people experience significant skin reactions to the bites including: Systemic reactions that have been rarely associated with bed bugs include asthma and anaphylaxis. Treatment is not generally required. However, various treatments may relieve the symptoms of bed bug bites: Firstly bed bugs must be correctly identified. A thorough search of the cracks and crevices of the bed and surrounding areas should be undertaken to detect the easily visible bed bugs or their faecal matter. Eradication of bed bugs can be difficult and requires chemical and non-chemical control strategies. Hire a licensed professional pesticide applicator with experience in treating bed bugs. For further details, refer to the links in our Related information section below. Once clear of bed bugs prevent recurrence by enclosing mattress and pillows, removing clutter, and reducing hiding places for the bugs. Each bed leg or caster can be placed in a container of talcum powder or wrapped in adhesive tape (sticky side out) to act as a barrier to the bugs. See the DermNet NZ bookstore. © 2020 DermNet New Zealand Trust. DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice.
Antoine Henri Becquerel (1852-1908) was a French physicist and winner of the 1903 Nobel Prize in Physics. Becquerel was born in Paris, France on December 15, 1852. He was the son of a professor of applied physics, Alexander Becquerel. He began his studies in 1872 at École Polytechnique just south of Paris. After a couple of years, he began working for the French government’s Department of Roads and Bridges. In 1894, he was appointed chief engineer of the department. Becquerel received a Doctor of Science degree in 1888. He later became Professor of Applied Physics in the Department of Natural History at the Paris Museum, a post his father had held previously. In 1895, he was appointed Professor at École Polytechnique. In 1896, Becquerel discovered natural radioactivity. Earlier that year, German physicist, Wilhelm Röntgen discovered x-rays. A type of phosphorescence had been present in vacuum tubes during Röntgen’s experiment. This caused Becquerel to wonder if there was any link between x-rays and naturally occurring phosphorescence. He conducted an experiment on uranium salts, which he inherited from his father. He hypothesized that the uranium would absorb light and reemit it as x-rays. He put the uranium on photographic plates. He developed the plates and observed that the uranium had, in fact, emitting radiation similar to x-rays. However, on a cloudy day in March, Becquerel decided to develop photographic plates of uranium that had not been exposed to sunlight. He found that even without contact to sunlight, the uranium was emitting radiation. While Becquerel initially believed the rays he was observing were similar to x-rays, further experiments should that unlike x-rays, the magnetic and electric fields of these rays could be deflected. Becquerel had, in fact, discovered radioactivity. He died in Le Croisic, France on August 25, 1908.
5.OA.B.3 Generate two numerical patterns using two given rules. Identify apparent relationships between corresponding terms. Form ordered pairs consisting of corresponding terms from the two patterns, and graph the ordered pairs on a coordinate plane. 5.NBT.A.2 Explain and apply patterns in the number of zeros of the product when multiplying a number by powers of 10. Explain and apply patterns in the values of the digits in the product or the quotient, when a decimal is multiplied or divided by a power of 10. Use whole-number exponents to denote powers of 10. 5.NBT.B.6 Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, subtracting multiples of the divisor, and/or the relationship between multiplication and division. Illustrate and/or explain the calculation by using equations, rectangular arrays, area models, or other strategies based on place value. 5.NBT.B.7 Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; justify the reasoning used with a written explanation. 5.NF.A Use equivalent fractions as a strategy to add and subtract fractions. 5.NF.A.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. 5.NF.A.2 Solve word problems involving addition and subtraction of fractions. 5.NF.A.2a Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. 5.NF.B Apply and extend previous understandings of multiplication and division to multiply and divide fractions. 5.NF.B.3 Interpret a fraction as division of the numerator by the denominator (a/b = a ÷ b). Solve word problems involving division of whole numbers leading to answers in the form of fractions or mixed numbers, e.g., by using visual fraction models or equations to represent the problem. 5.NF.B.4c Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area is the same as would be found by multiplying the side lengths. 5.NF.B.5b Explaining why multiplying a given number by a fraction greater than 1 results in a product greater than the given number (recognizing multiplication by whole numbers greater than 1 as a familiar case). 5.NF.B.7c Solve real-world problems involving division of unit fractions by non-zero whole numbers and division of whole numbers by unit fractions, e.g., by using visual fraction models and equations to represent the problem. 5.MD.A Convert like measurement units within a given measurement system. 5.MD.A.1 Convert among different-sized standard measurement units within a given measurement system, and use these conversions in solving multi-step, real-world problems (e.g., convert 5 cm to 0.05 m; 9 ft to 108 in). 5.MD.B.2 Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use operations on fractions for this grade to solve problems involving information presented in line plots. 5.MD.C.5 Relate volume to the operations of multiplication and addition and solve real-world and mathematical problems involving volume. 5.MD.C.5a Find the volume of a right rectangular prism with whole-number side lengths by packing it with unit cubes, and show that the volume is the same as would be found by multiplying the edge lengths, equivalently by multiplying the height by the area of the base. Represent threefold whole-number products as volumes, e.g., to represent the associative property of multiplication. 5.MD.C.5b Apply the formulas V = l × w × h and V = b × h for rectangular prisms to find volumes of right rectangular prisms with whole-number edge lengths in the context of solving real-world and mathematical problems. 5.MD.C.5c Recognize volume as additive. Find volumes of solid figures composed of two non-overlapping right rectangular prisms by adding the volumes of the non-overlapping parts, applying this technique to solve real-world problems. 5.G.A Graph points on the coordinate plane to solve real-world and mathematical problems. 5.G.A.1 Use a pair of perpendicular number lines, called axes, to define a coordinate system, with the intersection of the lines (the origin) arranged to coincide with the 0 on each line and a given point in the plane located by using an ordered pair of numbers, called its coordinates. Understand that the first number in the ordered pair indicates how far to travel from the origin in the direction of one axis, and the second number in the ordered pair indicates how far to travel in the direction of the second axis, with the convention that the names of the two axes and the coordinates correspond (e.g., x-axis and x-coordinate, y-axis and y-coordinate).
I encountered this diagram when reading an explanation about why the front wheels of cars lift up when they accelerate. The diagram is in the reference frame of the car, so that there is a fictitious force $MA$ on the center of mass. $f_1$ and $f_2$ are the frictional forces on the wheels. Now the car is not moving backwards and accelerating forwards. It is moving forwards and accelerating forwards. So when viewed from an inertial frame, $f_1$ and $f_2$ should point opposite to $A$, right? Yet why does it point in the same direction as $A$ in the reference frame of the car? We aren't interested in the bulk motion of the vehicle, only the relative motion of the part of the car touching the road (the bottom of the wheel). It's often useful to imagine what would happen if we turned friction to zero. We'll let the car move forward a bit and then turn it off. As the accelerator pedal is pressed, the wheel will slip and spin forward. Looking at the ground, the bottom of the wheel moves backward relative to the ground. So when friction returns, the force appears opposite to the relative motion of the tire, and it points forward. Another way to see this is that a car rolling forward may be coasting (no frictional force), accelerating (friction accelerates the car forward), or braking (friction accelerates the car backward). You can't tell the direction of friction by looking at the speed of the car. For the vehicle to move in the direction pointed to by A, the wheels have to rotate clockwise in the reference image. Thus the direction in which the wheels push the ground is opposite to A and consequently the ground pushes the wheels or you could say the entire car frame in the direction of A (3rd Law). These are the forces f1 and f2 depicted in the image. Note that we always show those forces which are acting ON our frame of reference by elements outside the frame, which is the road in this case providing friction.
Watercolor painting is a painting method. A watercolor is either the medium or the resulting artwork. Watercolor, also known in French as aquarelle, is named for its primary component. It consists of a pigment dissolved in water and bound by a colloid agent (usually a gum, such as gum arabic); it is applied with a brush onto a supporting surface, such as vellum, fabric, or—more typically—dampened paper. The resulting mark (after the water has evaporated) is transparent, allowing light to reflect from the supporting surface, to luminous effect. Watercolor is often combined with gouache (or "bodycolor"), an opaque water-based paint containing a white element derived from chalk, lead, or zinc oxide. The technique of water-based painting dates to ancient times, and belongs to the history of many cultures in the world. In the West, European artists used watercolor to decorate illuminated manuscripts and to color maps in the Middle Ages, and to make studies from nature and portrait miniatures during the Renaissance. When the Western world began to mass produce paper, the medium took on a whole new dimension of creativity. The advantages of watercolor lie in the ease and quickness of its application, in the transparent effects achievable, in the brilliance of its colors, and in its relative cheapness. Watercolor is a tradition that dates back to primitive man using pigments mixed with water to create cave paintings by applying the paint with fingers, sticks and bones. Ancient Egyptians used water-based paints to decorate the walls of temples and tombs and created some of the first works on paper, made of papyrus. But it was in the Far East and Middle East that the first watercolor schools or predominant styles emerged in the modern sense. Chinese and Japanese masters painted on silk as well as exquisite handmade paper. Their art was filled with literary allusion and calligraphy, but the primary image was typically a contemplative landscape. This characteristic anticipated what was to be a central aspect of Western watercolor traditions in later centuries. In India and Persia, the opaque gouache paintings created by the Moslems depicted religious incidents derived from Byzantine art. During the Middle Ages, monks of Europe used tempera to create illuminated manuscripts. These books were considered a major form of art, equivalent to easel painting in later years. The most famous illuminated book was by the Limbourg brothers, Paul, Herman, and Jean. This calendar, Les Tres Riches Heures du Duc de Berry, or sometimes called "The Book of Hours," was created about 1415. Medieval artists also worked in fresco which continued throughout the Renaissance. Fresco is a method by which pigments are mixed with water and applied to wet plaster. This method was used primarily to create large wall paintings and murals by such artists as Michelangelo and Leonardo da Vinci. The most famous fresco is Michelangelo's Sistine Chapel of the Vatican, painted from 1508 to 1512. Paper played an important role in the development of watercolor. China has been manufacturing paper since ancient times. The Arabs learned their secrets during the eighth century. Paper was imported to Europe until the first papermaking mills were finally established in Italy in 1276. A few other mills developed later in other parts of Europe, while England developed its first mills by 1495. However, high-quality paper was not produced in Britain until much later, during the eighteenth century. During and after the Renaissance, artists like Albrecht Durer, Rembrandt, Peter Paul Rubens, and Sir Anthony van Dyck used watercolors to tint and shade drawings and woodcuts. In Germany, Dürer's (1471-1528) watercolors led to the establishment of a school of watercolor painting that was led by Hans Bol (1534-1593). Durer is traditionally considered the first master of watercolor because his works were full renderings used as preliminary studies for other works. Since paper was considered a luxury item in these early ages, traditional Western watercolor painting was slow in evolving. The increased availability of paper by the fourteenth century finally allowed for the possibility of drawing as an artistic activity. From the seventeenth century to the present, the British school of watercolor, which especially features landscape subjects, has been perhaps the most continuous and widely followed tradition in Europe. Among the most famous of the artists are: Alexander Cozens, William Gilpin, Thomas Gainsborough, Francis Towne, Paul Sandby, Thomas Girtin, John Sell Cotman, Samuel Palmer, William Blake, John Constable, J. M. W. Turner, and Richard Parkes Bonnington. The three English artists credited with establishing watercolor as an independent, mature painting medium are Paul Sandby (1730-1809), Thomas Girtin (1775-1802), who pioneered watercolor's use in large format landscape painting, and J. M. W. Turner (1775-1851). Turner created hundreds of historical, topographical, architectural, and mythological paintings. His method of developing the watercolor painting in stages, starting with large, vague color areas established on wet paper, then refining the image through a sequence of washes and glazes, permitted him to produce large numbers of paintings with workshop efficiency and made him a multimillionaire in part through sales from his personal art gallery, the first of its kind. Among the important and highly talented contemporaries of Turner and Girtin were John Varley, John Sell Cotman, Anthony Copley Fielding, Samuel Palmer, William Havell, and Samuel Prout. The Swiss painter Louis Ducros was also widely known for his large format, romantic paintings in watercolor. The American West was an important area in the history of American art, and of watercolor in particular. Much of the record of exploration of the lands and people west of the Mississippi was kept by artists whose only means of painting was watercolor. George Catlin (1796-1870) was one of the "explorer artists" who used watercolor to document his travels among Indian tribes during the 1830s. Thomas Moran's watercolor sketches of Yellowstone, in 1871, so impressed Congress that they voted to make Yellowstone the nation's first National Park. The American Society of Painters in Watercolor (now the American Watercolor Society) was founded in 1866. Major nineteenth century American exponents of the medium included William Trost Richards, Fidelia Bridges, Thomas Moran, Thomas Eakins, Henry Roderick Newman, John LaFarge, and, preeminently, Winslow Homer. Watercolor was less popular in continental Europe, though many fine examples were produced by French painters, including Eugene Delacroix, Francois-Marius Granet, Henri-Joseph Harpignies, and the satirist Honore Daumier. Among the many twentieth century artists who produced important works in watercolor were Wassily Kandinsky, Emil Nolde, Paul Klee, Egon Schiele, and Raoul Dufy; in America the major exponents included Charles Burchfield, Edward Hopper, Charles Demuth, Elliot O'Hara, and, above all, John Marin, 80 percent of whose total output is in watercolor. In this period, American watercolor (and oil) painting was often imitative of European Impressionism and Post-Impressionism, but significant individualism flourished within "regional" styles of watercolor painting in the 1920s to 1940s, in particular the "Ohio School" of painters centered around the Cleveland Museum of Art, and the "California Scene" painters, many of them associated with Hollywood animation studios or the Chouinard School of Art (now CalArts Academy). During the 1940s, artistic experimentation became a major focus in the New York City art scene resulting in the development of Abstract Expressionism. Watercolor began to lose a certain amount of its popularity. It was not a medium which played a role in the evolution of the new movement in abstraction. Watercolors were small and intimate in scale and were subordinate to the huge canvases of the Abstract Expressionists. However, one such artist, Mark Rothko (1903-1970), utilized large areas of transparent washes and color staining on his canvases to create large scale works which were atmospheric, contemplative, and reminiscent of the watercolor tradition. Later, a second generation of Abstract Expressionist, including Sam Francis (1923-1994) and Paul Jenkins (b. 1923), also employed similar wash methods to produce transparent color fields on large canvases. By incorporating watercolor techniques into canvas painting, American artists not only re-popularized the medium but continued a long tradition of innovative experimentation. Watercolors continue to be utilized by important artists such as Joseph Raffael, Andrew Wyeth, Philip Pearlstein, Eric Fischl, Gerard Richter, and Francesco Clemente. Modern watercolor paints are now as durable and colorful as oil or acrylic paints, and the recent renewed interest in drawing and multimedia art has also stimulated demand for fine works in watercolor. Albrecht Durer's Tal von Kalchreuth (1494-1495) J.M.W. Turner's Ein Bett:Faltenwurfstudie Winslow Homer'sAfter the Hurricane (1899) Commercial watercolor paints come in two grades: "Artist" (or "Professional") and "Student." Artist quality paints are usually formulated using a single pigment, which results in richer color and vibrant mixes. Student grade paints have less pigment, and often are formulated using two or more less expensive pigments. Artist and Professional paints are more expensive but many consider the quality worth the higher cost. Paints comprise four principal ingredients: Thanks to modern industrial organic chemistry, the variety, saturation (brilliance), and permanence of artists' colors available today is greater than ever before. A brush consists of three parts: The tuft, the ferrule and the handle. The tuft is a bundle of animal hairs or synthetic fibers tied tightly together at the base; the ferrule is a metal sleeve that surrounds the tuft, gives the tuft its cross sectional shape, provides mechanical support under pressure, and protects from water the glue joint between the trimmed, flat base of the tuft and the lacquered wood handle, which is typically shorter in a watercolor brush than in an oil painting brush, and also has a distinct shape—widest just behind the ferrule and tapering to the tip. Every watercolor painter works in specific genres and has a personal painting style and "tool discipline," and these largely determine his or her preference for brushes. Most watercolor painters before 1800 had to use whatever paper was at hand: Thomas Gainsborough was delighted to buy some paper used to print a Bath tourist guide, and the young David Cox preferred the heavy paper used to wrap packages. James Whatman first offered a wove watercolor paper in 1788, and the first machinemade ("cartridge") papers from a steam powered mill in 1805. All art papers can be described by eight attributes: Furnish, color, weight, finish, sizing, dimensions, permanence, and packaging. Watercolor painters typically paint on paper specifically formulated for watermedia applications. Fine watermedia papers are manufactured under the brand names Arches, Fabriano, Hahnemuehle, Lanaquarelle, Saunders Waterford, Strathmore, Winsor & Newton, and Zerkall; and there has been a recent remarkable resurgence in handmade papers, notably those by Twinrocker, Velke Losiny, Ruscombe Mill, and St. Armand. Watercolor painting has the reputation of being quite demanding; it is more accurate to say that watercolor techniques are unique to watercolor. Unlike oil or acrylic painting, where the paints essentially stay where they are put and dry more or less in the form they are applied, water is an active and complex partner in the watercolor painting process, changing both the absorbency and shape of the paper when it is wet and the outlines and appearance of the paint as it dries. The difficulty in watercolor painting is almost entirely in learning how to anticipate and leverage the behavior of water, rather than attempting to control or dominate it. Basic watercolor technique includes washes and glazes. In watercolors, a wash is the application of diluted paint in a manner that disguises or effaces individual brush strokes to produce a unified area of color. Typically, this might be a light blue wash for the sky. A glaze is the application of one paint color over a previous paint layer, with the new paint layer at a dilution sufficient to allow the first color to show through. Glazes are used to mix two or more colors, to adjust a color (darken it or change its hue or chroma), or to produce an extremely homogeneous, smooth color surface or a controlled but delicate color transition (light to dark, or one hue to another). This method is currently very popular for painting high contrast, intricate subjects, in particular colorful blossoms in crystal vases brightly illuminated by direct sunlight. Wet in wet includes any application of paint or water to an area of the painting that is already wet with either paint or water. In general, wet in wet is one of the most distinctive features of watercolor painting and the technique that produces the most striking painterly effects. At the other extreme from wet in wet techniques, drybrush is the watercolor painting technique for precision and control, supremely exemplified in many botanical paintings and in the drybrush watercolors of Andrew Wyeth. The goal is to build up or mix the paint colors with short precise touches that blend to avoid the appearance of pointilism. The cumulative effect is objective, textural, and highly controlled, with the strongest possible value contrasts in the medium. All links retrieved August 11, 2013. New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here: The history of this article since it was imported to New World Encyclopedia:
BOREAS: Boreal Ecosystem Atmosphere Study The Boreal Ecosystem-Atmosphere Study (BOREAS) is a large-scale international interdisciplinary experiment in the northern boreal forests of Canada. Its goal is to improve our understanding of the boreal forests -- how they interact with the atmosphere, how much CO2 they can store, and how climate change will affect them. BOREAS wants to learn to use satellite data to monitor the forests, and to improve computer simulation and weather models so scientists can anticipate the effects of global change. \|Begin Date\|\|1994-05-24 00:00:00\| \|End Date\|\|1994-09-19 23:59:59\| Map data from IBCSO, IBCAO, and Global Topography. Maximum (North) Latitude: Minimum (South) Latitude: Minimum (West) Longitude: -112.00, Maximum (East) Longitude: -93.00
Salona was an ancient city located at the estuary of the river Jadro in present-day Solin, a suburb of Split on the Adriatic coast of Croatia. It became the capital of the Roman province of Dalmatia in 9 CE. Before the Romans Salona was a settlement of the Dalmatean, an Illyrian people who lived on the shore of the Adriatic. During the 3rd century BCE, Greek colonists from the island of Issa founded an emporium (trade centre) on the coast north of Salona and another one to the south. In 117 BCE the Roman general Metellus Macedonicus invaded Salona and finally in 78 BCE it was permanently conquered. About 33 BCE, during Augustus' reign, Salona became a Roman colony. A few years later, Augustus conquered the entire region from the Danube to the Adriatic coast. This newly conquered area came to be known as the province of Illyria with Salona as its capital. however, the province was too big and too challenging to be managed by a single governor and, therefore, Augustus decided to split Illyria in two: the southwestern half being named Dalmatia with Salona remaining as its capital. During this time the city flourished and acquired all the characteristics of an important Roman city: defensive walls, a theatre, an amphitheatre for 15,500 spectators and a forum. In 170 CE, during the time of Marcus Aurelius, a new wall enclosing all three sections of the city was built and the population is estimated as around 50,000. Salona remained Roman for longer than most of the other cities in the western half of the Roman Empire. During the 5th century CE it was home to the governor of Dalmatia, Julius Nepos, the last man entitled to claim the throne of the Western Roman Empire. He was recognized as Emperor of the West for a brief length of time (473-475 CE) but ultimately he was deposed and returned to Salona. He was still accepted as Emperor by some until 480 CE. The city became part of the East Roman Empire and it was given to Theodoric, a Gothic king, in 493 CE. The Emperor Justinian brought Salona back under Roman control in 535 CE; he rebuilt its fortifications and Salona remained one of the key ports of the empire. Salona is particularly important for the study of early Christian society and architecture. During the 5th and 6th centuries CE a number of churches were built in the city and also basilicas with large cemeteries containing martyrs' burials. In 530 and 533 CE, regional church councils were also held in Salona. Shortly after this, invading Slav tribes from across the Danube began to threaten the region but they did not reach the Aegean coast. During the rest of the 6th century CE Salona was a fairly secure place but by the beginning of the 7th century CE things had changed rapidly: all over the Balkans, Slav tribes moved freely as a result of the collapse of the frontier defences. Salona resisted for some time but about 614 CE its inhabitants abandoned their homes and fled to Split, where the emperor Diocletian had a palace built for his retirement and which offered a more readily defensible haven.
Although the term “sonnet” merely refers to a diminutive version of the Italian for “sound” (Oppenheimer 291), the poetic form has come to inhabit a highly contested space for writers and critics alike. In the case of Claude McKay and the Harlem Renaissance, the sonnet raises questions concerning the identity of modernist poetry, and, further, how colonized voices should interact with forms originating from the colonizer. Claude McKay, a Jamaican-born poet, was one of the first black writers to achieve recognition with his 1911 Jamaican-dialect poems in The Daily Gleaner (Hunter 566). Later in his career, however, McKay turned away from dialect poems in favor of sonnets in Standard English, for which he is now known. Often associated with the Harlem Renaissance of the 1920s, McKay’s fourth, and perhaps most well-known, book of poetry was Harlem Shadows, published in 1922, and it is this association that sparks much of McKay’s criticism. McKay’s adherence to classic forms starkly contrasts other Harlem Renaissance contemporaries, like Langston Hughes, whose poetry followed fewer conventional forms and moved towards incorporating more everyday speech patterns in their writing. McKay, for his sonnets and Standard English, is accused of imitating the colonizer’s speech and forgoing his black and Jamaican roots to achieve “universality.” However, dialect, nation speak, and form are not the only means of reclaiming narrative and “writing back” to empire. These elements, rather than depicting a new narrative for a historically “othered” voice, end up acting as a means to exoticize the voice of a black “other,” especially during McKay’s time. Through a primary focus on the 1921 poem “Jasmines,” close reading reveals that Claude McKay’s Standard English sonnets shirk white expectation, respond to colonial discourse, and decentralize a standardized British narrative through conversation with the very form of the sonnet itself. As a black Jamaican writer at the turn of the 20th century, it is common for criticism of Claude McKay’s poetry to focus on the group that the critic believes McKay should have written to represent. For example, in “History of the Voice,” Kamau Brathwaite, a Barbadian poet and academic, wrote on the importance of “nation language” as a means of representing and validating colonized, Caribbean voices. In the essay, Brathwaite uses McKay as an example of a Caribbean poet who “[i]n order to be ‘universal,’… forshook his nation language … and went to the sonnet … McKay allowed himself to be imprisoned in the pentameter; he did not let his language find its own parameters” (283). McKay’s adherence to the sonnet form, for Brathwaite, acts as a way to hide his Caribbean roots and thus fail to artistically give his colonized voice representation. Brathwaite mistakenly equates “universality” with a non-typed voice that does not imply specific place, despite referring to an English dialect and poetic form derived from Europe. Brathwaite assumes that McKay’s use of any “standard” is without intention and is unrelated to place since it is not related to Caribbean dialect specifically. Brathwaite, however, fails to recognize that McKay chose to “find his own parameters” in the sonnet after establishing himself as a dialect poet in The Daily Gleaner a decade before his Standard English sonnets. With his first poems, McKay extensively utilized the “nation speak” that Brathwaite called for in the Jamaican journal The Daily Gleaner. McKay’s “nation speak” is expemplified in the 1911 poem “Agnes o’ de Village Lane,” which included such lines as “In de school-room worn an’ old/Fus’ I saw your pretty smile” (“Agnes o’ de Village Lane” lines 7-8) and “For dey t’umped an’ beat poor me/Tell me skin tu’n black an’ blue” (“Agnes o’ de Village Lane” lines 14-15). In these poems, it is clear that McKay attempts to show a more Caribbean manner of speech through leaving letters out of words like “an’,” “t’umped,” and “tu’n,” or by giving certain words alternative spellings completely like “fus’,” “dey,” and “tell.” Upon discovering McKay’s dialect poems in this style, Walter Jekyll, the first of several white patrons throughout McKay’s life, praised the Jamaican poet, claiming “this is the real thing” (qtd. in North 101). What, however, is the “real thing?” What was the real “Negro” being depicted for the journals’ mostly white readership? It is telling what McKay’s white readership wanted from his dialect poems from the criticism he faced upon turning toward Standard English sonnets a decade later. Robert Minor once told McKay, “You are ‘not a real Negro’ … when he [McKay] confessed to liking E.E. Cummings” (qtd. in North 103), and Roy Fuller, in a “Caribbean Voices” broadcast, insisted that Caribbean poets, like, one may assume, McKay, had to stop writing like Keats and “learn to write like themselves” (qtd. in Breiner 114). Just like Walter Jekyll’s praise for the “real thing,” Brathwaite, Minor, and Fuller’s beliefs concerning the correct “nation language” for Caribbean expression warrant examination. Phrases like “own parameters” and “like themselves” indicate a desire to let the poet speak for himself, but, in the end, merely stipulate that that self should reflect a very narrow manner of preconceived speech representing a carefully maintained “other” in an imagined dichotomy between Standard English and its received derivations. Walt Hunter’s “Claude McKay’s Constabulary Aesthetics: The Social Poetics of the Jamaican Dialect Poems” begins to unpack many of these assumptions, but spends the article’s bulk examining McKay’s early dialect poems from The Daily Gleaner. Pointing to McKay’s use of dialect in order to manipulate and push standard forms, Hunter argues that McKay’s sonnets were not a misrepresentation of black voice. Instead, for McKay, “[i]t is the layering of vernacular and Standard English, not the choice between them, that we find…The formal intricacy of McKay’s poems depends on the use of dialect” (757). Hunter praises McKay for his manipulations for the sonnet with “modernist innovation” (583), but, through his criticism, continues to laud the dialect poem as the only valid means of expression for the Caribbean poet. Rather than further discussing McKay’s dialect poems—which were originally produced under the insistence of a white benefactor to fit narrow ideas of black voice—it is the Standard English poems that warrant a closer look. Although Hunter outlines McKay’s manipulation of standard form, he comes just short of fully engaging with everything McKay accomplishes through inhabiting the space between configuration and liberation in his Standard English sonnets. Looking specifically at the poem “Jasmines,” the subject, in conjunction with the specific instances in which the form is adhered to and not, converses with the sonnet’s expectations in order to write back to imperial tradition from a uniquely Caribbean perspective that does not rely on dialect’s easy signifiers. The fifteen-line sonnet first published in 1921 goes: Flora, like that in “Jasmines,” holds a long tradition in post-colonial writing, native species being a clearly distinctive feature between colonized and colonizer countries. Flowers, specifically, are commonly used in response to European literary traditions, often in relation to Wordsworth’s daffodils in “I Wandered Lonely as a Cloud,” which children across the British empire were required to memorize for school, despite having no daffodils in their own countries (Reiss 180-182). Claude McKay’s Jamaica would have been among the colonies under a standardized British educational system subject to memorizing Wordsworth. In an immediately post-slavery Jamaica (around 1834 to 1838), education was the intended mechanism for relieving fears about the sudden departure of slavery’s controls and the ensuing destabilization of Caribbean society; it was a way to maintain social control and preserve the plantation and plantocracy. In the 1860s, the British government reformed Caribbean education to include The System of Payment by Results, where schools only received funding if they passed standardized examinations, often characterized by rote memorization (King). Especially considering that standardized examinations are built around the notion of right and wrong, forcing school children to memorize European cultural norms for basic funding functioned to create a European center for what was correct and normal, in effect marginalizing colonies as spaces of difference and otherness. This system of colonial education is the center piece to post-colonial arguments like those put forward by Bill Ashcroft, Gareth Griffiths, and Helen Tiffin in their seminal work The Empire Writes Back. “[T]hrough the literary canon,” they argue, “the body of British texts which all too frequently still acts as a touchstone of taste and value, and through RS-English (Received Standard English), which asserts the English of south-east England as a universal norm, the weight of antiquity continues to dominate cultural production in much of the post-colonial world” (6). Kamau Brathwaite also points to a standardized British educational system as a form of everyday colonial life that requires literary “nation speak” to respond to England throughout his “History of the Voice.” The sonnet and its descriptions of British flora become the expected norm for poetry, art, and culture. Even in countries whose speech did not imitate iambic pentameter and whose landscape did not resemble rolling hills of daffodils, British colonies were placed in a cultural other, as taught in their own schools and internalized through mandatory memorization. All of Wordsworth’s poem follows a perfect iambic tetrameter consisting of eight syllables alternating between unstressed and stressed syllables. McKay’s poem, on the other hand, continuously interrupts his iambic pentameter of ten syllables alternating between unstressed and stressed. Notably, most of these interruptions occur with lines containing the word “jasmines,” which he positions in ways that encourage trochaic (stressed then unstressed), anapestic (unstressed, unstressed, stressed), and dactylic (stressed, unstressed, unstressed) patterns all in one phrase (lines 3, 9, 14). The only quatrain, in fact, where McKay employs continuous, uninterrupted iambic pentameter is in the third. Beyond adhering to iambic pentameter, this quatrain also departs from the very subject of jasmines and instead delves into a description of cold climates uncharacteristic to the Caribbean. Walt Hunter, in his analysis of the poem, considers the English sonnet “the ‘cold place’ where McKay’s jasmines should not be able to bloom—and yet, paradoxically, the only place they can” (582). However, the quatrain in full iambic pentameter’s departure into England’s cold climate aligns the perfect sonnet form, and, by relation, England itself, with that which is not hospitable to Caribbean identity. The jasmine is not present in “the street … wet and weird with snow,” “weird” functioning to reverse colonialist discourse and to other the colonist’s climate. Instead, the poem finds its resolution “here,” where the jasmines grow, in the final couplet. McKay re-centers poetic discourse from England to the Caribbean and finds luxury not in the culture of the empire, but in the make-up of the colonies’ own defining attributes. The poem, in turn, transforms the assumed story of a lover scented by jasmines into a recasting of finding one’s identity in a colonized space. Especially in the context of a colonialist education system which forced rote memorization of English poetry, the line crossing the first two quatrains, “Your face was in the mirror. I could see/You smile and vanish suddenly away” (“Jasmines”) comes to define the poem’s purpose. As with Homi Bhabha’s evaluation of colonialist discourse from the 1980s, mirrors have an important colonial distinction (29, 33) since the colonizer forces its cultural image onto its colonies and tries to recreate their mirror image overseas. In “Jasmines,” the mirrored face asserts questions of colonial identity caught between its native land and an invading foreign culture. “Your face” is what “I could see” in the mirror, skewing clear-cut definitions of the self. However, the you in the poem is also inextricably tied to the idea of jasmines and, by extension, the Caribbean. The speaker is overwhelmed by their scent before their face vanishes in the second and third quatrains to be replaced by a British storm, leaving the author’s own face “sad [and] suffering from parting grown so dear.” Despite speaking as a Caribbean writer, McKay projects the Caribbean as a lover, rather than the self, whose voice is drowned out by the colonist’s “mad roar,” emphasizing the struggle to perpetuate cultural identity in a colonized space encouraged to mirror far-off daffodils. While the lover’s physical face may be lost, their scent remains in the room, growing and luxuriant. “Jasmines” may be a reflection of the colonialist poetic constraints found in the sonnet, but it rejects a full mirror image, and goes beyond an expected Caribbean voice by manipulating the sonnet form. Rather than writing Jamaican dialect or black dialect or following modernist trends, McKay engages with the sonnet just enough to highlight his minute deviations and thus give them added significance. The criticism that McKay faced both during his lifetime and concerning his legacy afterwards unfairly holds McKay up against narrow ideas of “nation speak” as the only means of conveying colonial subjecthood when, in practice, this often became means to goggle at the voice of an “other” contrasting a received European norm. Additionally, the Caribbean is a corner of the world whose islands changed European hands continuously throughout their histories and were, additionally, subject to African, indigenous, and North American influences. To say that McKay needed to speak for one, correct identity in his poetry would have been a misrepresentation of the Caribbean in and of itself by creating a generically “other,” unindividualized voice whose defining characteristic was merely opposing the European standards learned across the empire. McKay’s choice to speak through and manipulate the sonnet was thus a better illustration of a multicultural Caribbean identity than would have been possible through adhering to his dialect poems through the entirety of his oeuvre, despite the praise he received for this earlier style.
The search for exoplanets is heating up, thanks to the deployment of space telescopes like Kepler and the development of new observation methods. In fact, over 1800 exoplanets have been discovered since the 1980s, with 850 discovered just last year. That’s quite the rate of progress, and Earth’s scientists have no intention of slowing down! Hot on the heels of the Kepler mission and the ESA’s deployment of the Gaia space observatory last year, NASA is getting ready to launch TESS (the Transiting Exoplanet Survey Satellite). And to provide the launch services, NASA has turned to one of its favorite commercial space service providers – SpaceX. The launch will take place in August 2017 from the Cape Canaveral Air Force Station in Florida, where it will be placed aboard a Falcon 9 v1.1 – a heavier version of the v 1.0 developed in 2013. Although NASA has contracted SpaceX to perform multiple cargo deliveries to the International Space Station, this will be only the second time that SpaceX has assisted the agency with the launch of a science satellite. This past September, NASA also signed a lucrative contract with SpaceX worth $2.6 billion to fly astronauts and cargo to the International Space Station. As part of the Commercial Crew Program, SpaceX’s Falcon 9 and Dragon spacecraft were selected by NASA to help restore indigenous launch capability to the US. The total cost for TESS is estimated at approximately $87 million, which will include launch services, payload integration, and tracking and maintenance of the spacecraft throughout the course of its three year mission. As for the mission itself, that has been the focus of attention for many years. Since it was deployed in 2009, the Kepler spacecraft has yielded more and more data on distant planets, many of which are Earth-like and potentially habitable. But in 2013, two of four reaction wheels on Kepler failed and the telescope has lost its ability to precisely point toward stars. Even though it is now doing a modified mission to hunt for exoplanets, NASA and exoplanet enthusiasts have been excited by the prospect of sending up another exoplanet hunter, one which is even more ideally suited to the task. Once deployed, TESS will spend the next three years scanning the nearest and brightest stars in our galaxy, looking for possible signs of transiting exoplanets. This will involve scanning nearby stars for what is known as a “light curve”, a phenomenon where the visual brightness of a star drops slightly due to the passage of a planet between the star and its observer. By measuring the rate at which the star dims, scientists are able to estimate the size of the planet passing in front of it. Combined with measurements the star’s radial velocity, they are also able to determine the density and physical structure of the planet. Though it has some drawbacks, such as the fact that stars rarely pass directly in front of their host stars, it remains the most effective means of observing exoplanets to date. In fact, as of 2014, this method became the most widely used for determining the presence of exoplanets beyond our Solar System. Compared to other methods – such as measuring a star’s radial velocity, direct imaging, the timing method, and microlensing – more planets have been detected using the transit method than all the other methods combined. In addition to being able to spot planets by the comparatively simple method of measuring their light curve, the transit method also makes it possible to study the atmosphere of a transiting planet. Combined with the technique of measuring the parent star’s radial velocity, scientists are also able to measure a planet’s mass, density, and physical characteristics. With TESS, it will be possible to study the mass, size, density and orbit of exoplanets. In the course of its three-year mission, TESS will be looking specifically for Earth-like and super-Earth candidates that exist within their parent star’s habitable zone. This information will then be passed on to Earth-based telescopes and the James Webb Space Telescope – which will be launched in 2018 by NASA with assistance from the European and Canadian Space Agencies – for detailed characterization. The TESS Mission is led by the Massachusetts Institute of Technology – who developed it with seed funding from Google – and is overseen by the Explorers Program at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
The Heisenberg Uncertainty Principle is a relationship between certain types of physical variables like position and momentum, which roughly states that you can never simultaneously know both variables exactly. Informally, this means that both the position and momentum of a particle in quantum mechanics can never be exactly known. Mathematically, the Heisenberg uncertainty principle is a lower bound on the product of uncertainties of a pair of conjugate variables. The most well-known expression takes the position and momentum to be the conjugate variables: Suppose the position of a particle is known to very high precision, so that is very small. Then the uncertainty principle shows that must be large, i.e. the momentum is not known precisely. Furthermore, neither uncertainty can vanish, so neither position nor momentum can ever be exactly measured. States that saturate the inequality in the Heisenberg uncertainty principle are called squeezed states, of which coherent states like the photon states in a laser are a subclass. The uncertainty principle relates the standard deviations of two conjugate variables, which are any two variables related to each other by the Fourier transform. For example, the wavefunction of a free particle is: where the are states of definite momentum, i.e. eigenstates of the momentum operator. If we let , the integral becomes Therefore, the position-space wavefunction is indeed the Fourier transform of another wavefunction that is dependent on momentum instead. This wavefunction, , is called the momentum-space wavefunction. The momentum-space wavefunction can be recovered given the position-space wavefunction by taking the inverse Fourier transform: This Fourier analysis achieves the interesting result of displaying the direct relationship between two variables and that describe the same wave-packet in different spaces. In this example, a free particle is measured in the position space by , but measured in the momentum space by . Regardless of which space one chooses to measure the particle, the physics doesn't change. Therefore, this relationship of conjugate variables allows one to measure particles in physical experiments in two ways. In fact, much of crystallography and solid-state physics relies on measurements made in momentum space in lieu of position space. The standard deviation of some variable is defined by That is, gives the average squared difference from the mean . The uncertainty principle holds for any quantum mechanical state . To derive the uncertainty principle thus requires consideration of the expectation value of in some arbitrary state . This expectation value is given by: Since is Hermitian, setting gives . Similarly, the momentum uncertainty is written: A clever application of the Cauchy-Schwarz inequality gives the rough form of the Heisenberg uncertainty principle: To obtain the final expression, compute the right-hand side above: Taking the complex conjugate, Using the following property of complex numbers: replacing with and with yields Substituting back in for all of the inner products previously computed, this translates to This is the generalized Heisenberg uncertainty principle. Note that no part of the above derivation uses the fact that and represent position and momentum, only the fact that they are conjugate variables. Therefore, the above inequality holds for any two conjugate variables. The canonical commutation relation gives . Substituting in above and taking the square root yields the most well-known form of the Heisenberg uncertainty principle: Another uncertainty relation which is often referenced in discussion of quantum mechanics is the energy-time uncertainty principle, It is tempting to interpret this equation as the statement that a system may fluctuate in energy by an arbitrarily large amount over a sufficiently short time scale. This explanation is often given as a description for particle-antiparticle production and annihilation, where a particle and its antiparticle appear spontaneously from the vacuum briefly via "borrowed" energy before colliding and returning to vacuum. However, this explanation is not very precise and the given inequality is not so well-defined in quantum mechanics despite the nice physical interpretation. The reason it is not well-defined is because there is no operator in quantum mechanics corresponding to the measurement of time, although the Hamiltonian is the operator corresponding to energy. Nevertheless, as explained in this section, there is some way to make sense of an energy-time uncertainty principle by considering how the measurement of an arbitrary operator changes in time. Since time is not an operator, it is unclear how time enters quantum mechanics at all. The answer is that time is incorporated into the Schrödinger equation, where it describes the time rate of change of a wavefunction. Physically, the passage of time is recorded by noting that certain physical observables are changing over time: for instance, perhaps the position of a particle is changing, which one interprets as motion over time, or the momentum of a particle is changing, which one interprets as accelerating or decelerating over time. To quantify this statement, consider the Ehrenfest theorem governing the dynamics of the expectation value of an operator in terms of the commutator with the Hamiltonian: Assuming that does not depend explicitly on time (which is typically the case), the second term vanishes and the expectation value of the is generally nonzero. Therefore, and satisfy the generalized Heiseinberg uncertainty relation: Notably, since the Hamiltonian is the energy operator, corresponds to the uncertainty in energy. Taking square roots now gives the relation: Define by the relation: In other words, corresponds to the time it takes the measured value of to shift by , for any operator . Given this definition, substituting in yields the relation: which is a more rigorous expression of the energy-time uncertainty principle. Formally, using the definition of one can see that if the energy changes slowly, the rate of change of all expectation values of any observable operator must also be slow. This makes sense because if the energy (i.e., the Hamiltonian) changes slowly, the wavefunction itself that is evolved by the Hamiltonian changes slowly, so the expectation value of observables corresponding to measurements of that wavefunction must change slowly as well. The energy of an electron in a magnetic field is, in some unit system: where choice of positive or negative sign corresponds to spin-down or spin-up respectively, and is the spin magnetic moment of the electron. In an adiabatic transition, the parameters of a quantum system are gradually changed to bring a system smoothly from one state to another state. Suppose an electron starts in the spin-up ground state in a magnetic field of strength . The magnetic field is then reduced slowly to strength and then increased slowly again back to strength . Find the minimum time for the process of tuning the magnetic field to occur for which the electron is expected to remain in the spin-up ground state after the process ends. Hint: consider the energy-time uncertainty principle. Note: this is a very simple demonstration of the fact that adiabatically tuning electron spins requires relatively long time scales. Griffiths, David J. Introduction to Quantum Mechanics. Second Edition. Pearson: Upper Saddle River, NJ, 2006.
The History Of Vivisection During the Renaissance period, competitive intellectual inquiry emerged to overwhelm Church injunctions and Autopsies revealed medical inaccuracies that had prevailed for 1,300 years since Galen. For the first time, the medical community was starting to understand the real causes of disease. In the mid-nineteenth century a failed playwright turned animal experimenter, Claude Bernard conducted numerous experiments. The sheer volume of results – accurate or not – that resulted from his animal experiments effectively created an animal experimentation business. Medical research had started to branch out into areas not directly related to the Physician Industry. In other words, people who could not make it as Doctors could still make a living as animal experimenters (Vivisectors), and still influence medical advancement. In fact, the animal experimentation machine generated such an abundance of conclusions that those conclusion very often overwhelmed human evidence to the contrary. Soon, animal experimenters were asking for and receiving money for their research. Animal breeders began to make huge profit too and suppliers of lab equipment also enjoyed their expanding market. Despite the huge disparities in results between animals, and animals and humans, the growing industry was still seen to be providing useful information in the study of diseases. Then, in the 1930s a single incidence of a drug effecting an animal the same way it effected a human secured the use of animals for drug development too. Of course, the same problems persisted: Animals often reacted differently to the same chemical substances. However, the pharmaceutical industry was off and running, developing strong ties with animal experimenters and using their results to boost profits. The disaster of thalidomide, a drug designed to suppress morning sickness that led to over 10,000 babies with birth defects, spurred the US Congress to offer the American public every possible guarantee of medication safety. That “guarantee” took the form of animal testing. Nevermind that thalidomide itself had been tested on animals prior to release and had not imposed birth defects on them. And that even after scientists knew what to look for, they found birth defect from thalidomide only occasionally. In approximately10 strains of rats, 15 strains of mice, 11 breeds of rabbits, 2 breeds of dogs, 3 strains of hamsters, 8 species of primates and in other such varied species as cats, armadillos, guinea pigs, swine and ferrets in which thalidomide has been tested, teratogenic effects have been induced only occasionally. Nevermind also that there was already ample evidence that chemicals react very differently in different species. By legislating that all drugs must prove safe and effective in animals prior to release, the government created a legal safehouse for pharmaceutical companies and any other industry with a product of questionable medical safety. Ever since, when lawsuits occur, big business can justifiably claim that they acted with due diligence to the full extent of the law. Inevitably, big business’ enthusiasm over this legal safety net has played a large role in making animal experimentation a sacred cow.
How will climate change affect the Great Lakes? With much of the world focused on the Climate Talks in Copenhagen, Denmark over the past two weeks, many of you in the Great Lakes area may be wondering, “how will climate change affect the Lakes?” So let’s take a moment to briefly look at this question. Global concern with climate change is primarily focused on the amount of greenhouse gases in the atmosphere. Greenhouse gases, such as carbon dioxide, water vapor, and methane, among others, are an essential part of our atmosphere, and they serve a vital role in making our planet warm enough for life. Greenhouse gases trap energy (in the form of longwave radiation) that is being emitted by the Earth, reflecting it back into the atmosphere to warm the planet. As the amount of carbon dioxide in the atmosphere has increased or decreased over time, the planet’s temperature has changed in roughly the same proportion. Scientists have determined this relationship from studying ice cores taken from Antarctica which include ice which fell as snow from over 400,000 years ago. Right now there is more carbon dioxide in the atmosphere than at any time measured in the ice core. Scientists expect that this will lead to a gradual warming of the planet in most areas. But what does this specifically mean for the Great Lakes region? There are four aspects of the climate in the Great Lakes region where we can expect to see some changes: ice cover, evaporation levels, precipitation, and lake levels. Researchers have attempted to determine trends for total ice cover on the Great Lakes since 1963, unfortunately with little success. Ice cover has varied greatly from year to year. While it has dropped significantly over the last decade, the results are not conclusive enough to suggest that this is a trend. However, ice cover trends on smaller lakes in the Great Lakes region do show trends of freezing later and thawing earlier. Rates of evaporation and precipitation on the Great Lakes are difficult to project, and vary across the region. The Western region of the Lakes tends to be drier, while the Southeast area tends to have far more precipitation (“lake-effect” snow and rain). Climate change models suggest that temperatures will increase over the next century over the Great Lakes. Higher temperatures suggest an increase in evaporation, which should then lead to an increase in precipitation. This means that current trends will likely be accentuated, with the Western Region of the Lakes being slightly drier, while the Southeast will be slightly wetter. Warmer temperatures mean that less of this precipitation will fall as snow on average, although annual amounts will likely vary considerably. One key question scientists are trying to answer is whether the increase in evaporation will be greater than the increase in precipitation. Currently, scientists project that rates of evaporation will, on average, outpace rates of precipitation, although the degree of difference is still a subject of debate. But what does all of this mean for water levels in the Great Lakes? This is an important question; after all, our current infrastructure around the Lakes, from ports and canals to beaches and boardwalks, were designed and built based on the water levels experienced throughout the Twentieth Century. This is a far more complicated question than the one facing coastal cities along the oceans that are contending with sea level rise due to glacial melt and thermal expansion of water. Water levels in the Great Lakes will be determined almost entirely by levels of precipitation and evaporation, as well as by the quantities of water removed from the watershed through consumption or diversion. A further consideration is that water levels are controlled at two points; at the outflow from Lake Superior, and at the outflow from Lake Ontario, as regulated by the International Joint Commission. This suggests that the Lake Superior, as the upstream lake, will serve as the bellwether for the rest of the lakes. In reading through the many reports on this subject, most climate models suggest that we may see declines in lake levels over the next 100 years; one suggests that we may see declines of up to 2.5 meters (8.2 feet). Granted, this is hardly conclusive; another model that suggests a “wetter” future climate over the Great Lakes projects a small increase in lake levels. The truth is likely somewhere in between, with water levels falling between 0.23 meters and 2.5 meters. What is certain is that more research is needed to improve modeling of the climate in the Great Lakes region. There is a lot of information available on the web on the topics I have mentioned above. For summaries of the data from the Vostok Ice Core, check out the Carbon Dioxide Information Analysis Center. For more information on the subject of ice cover in the Great Lakes region, please look at “Impacts of Climate Change on Lake and River Ice Cover,” co-authored by John Magnuson, Director Emeritus of the Limnology Center at the University of Wisconsin, Madison. Further, a great resource on climate change is Chapter 11 of the Intergovernmental Panel on Climate Change’s (IPCC) Working Group 1 contribution to the Fourth Assessment Report. The section on North America starts on page 887; it was published in 2007, so it’s fairly up-to-date. One of the best reports analyzing climate models for the region that I have found is “Evaluation of Potential Impacts on Great Lakes Water Resources Based on Climate Scenarios of Two GCMs,” published in the Journal of Great Lakes Research (Lofgren, B. M., F. H. Quinn, A. H. Clites, R. A. Assel, A. J. Eberhardt, and C. L. Luukkonen, 2002). Finally, great work continues to be done at the Great Lakes Environmental Research Lab (GLERL), part of the National Oceanic and Atmospheric Administration. If any reader is familiar with more recent published work on climate modeling for the Great Lakes region, I would love to hear about it!
About This Chapter Teacher Resources for High School Algebra - Chapter Summary This chapter will provide you with resources that you may find useful in your high school algebra class, when teaching students about topics they may find confusing. Some of these topics include: - One-step equations - Algebraic expressions - Linear equations You'll be exposed to a variety of techniques you can use to help your algebra students, including math drills that offer a fun way to sharpen their skills. Short quizzes allow you to assess your understanding of teaching high school algebra, and you can always ask our instructors for help if you have a problem. How It Helps - Improves lesson plans These resources will provide you with suggestions about how you can improve your high school algebra lesson plans. - Teaches new learning strategies Learn about how you can use drills to improve students' understanding of algebraic expressions. - Enhances student understanding Discover new teaching ideas to improve your students' understanding of algebra. By the end of this chapter, you should be able to: - Create lesson plans for lessons on solving algebraic equations and inequalities - Implement games and other activities to improve students' understanding of algebra - Teach students about graphing linear equations - Use math drills to help students learn algebra 1. Solving One-Step Equations Lesson Plan Solving one-step equations may sound simple, but for many students they're a challenge. Teach how words translate words into a math problem with clear steps and several examples. Finish up with an activity. 2. Algebraic Expressions Games & Activities Algebra can be a lot of fun if you make the effort to engage students. A way to do that is to play games and involve students in activities. Here are some ideas to get you started. 3. Inequalities Lesson Plan Easy to read and understand, and full of examples and simple steps, this lesson plan will help you teach your students how to solve inequalities in a snap. Guided and independent work samples included, as well as a fun follow-up game. 4. Graphing Linear Equations Lesson Plan In this lesson, students will practice converting between the slope-intercept and standard forms of linear equations. Then, students will graph linear equations using two common procedure that each start with the standard form. 5. Math Drills for Algebra Math drills are a great way to give your students consistent algebra practice that doesn't feel quite so repetitive. There are many options for math drills; check out some of these ideas. Earning College Credit Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level. To learn more, visit our Earning Credit Page Transferring credit to the school of your choice Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you. Other chapters within the Algebra I: High School course - High School Algebra: Solving Math Word Problems - High School Algebra: Percent Notation - High School Algebra: Calculations, Ratios, Percent & Proportions - High School Algebra: Real Numbers - High School Algebra: Exponents and Exponential Expressions - High School Algebra: Properties of Exponents - High School Algebra: Radical Expressions - High School Algebra: Algebraic Expressions and Equations - High School Algebra: Algebraic Distribution - High School Algebra: Properties of Functions - High School Algebra: Working With Inequalities - High School Algebra: Linear Equations - High School Algebra: Factoring - High School Algebra: Quadratic Equations - High School Algebra: Graphing and Factoring Quadratic Equations - High School Algebra: Properties of Polynomial Functions - High School Algebra: Rational Expressions - High School Algebra: Matrices and Absolute Value - High School Algebra: Data, Statistics, and Probability
The butterfly is known for its wings rather than any part of its body. They are colored. When the butterfly is in flight, they add beauty and charm. The wings are borne by the middle part of the body, the thorax which is present in-between the head and the abdomen. The wings are on the upper side. On the lower side of the thorax, are the legs. The legs of butterfly are as important as the wings. There are three pairs of legs, the forelegs, the middle legs and the hind legs. Like any other insect leg, the butterfly leg is made up of five joints, the last joint or the foot bears grasping claws. When the butterfly sits on a flower or a leaf, the claws provide grip. The front pair of legs or the forelegs is nonfunctional. They are short and reduced, in most butterfly species. If at all they are of any use to the butterfly, it is merely to clean the feelers, or the antennae. The middle and hind legs are for walking. The muscles of the thorax control the wings and legs. When the butterfly is in the larval stage, it has the usual three pairs of legs. In addition there are up to five pairs of prolegs. The prolegs are not jointed. They bear tiny hooks arranged in rings at the tip. During metamorphosis, the prolegs disappear. In the adult butterfly, the legs serve important sensory functions as well. The legs bear pores, scales, and hairs. These are specialized sense organs. They can detect vibrations and sound, besides smell and taste. The smell and taste sense organs are on the feet of the legs. When the butterfly alights on a flower, these sensory structures examine the flower first. They assist the antennae or the feelers in determining the right plant and flower. These sense organs are of utmost importance for the butterfly in spotting the flower, since the eyes are ineffective and the vision a mere blur. One reason why certain furniture in our house holds are fitted with “butterfly legs” is probably because of their special functional significance and aesthetics.
Methane is a simple molecule consisting of just one carbon atom bound to four hydrogen atoms. But that simplicity belies the complex role the molecule plays on Earth—it is an important greenhouse gas, is chemically active in the atmosphere, is used in many ecosystems as a kind of metabolic currency, and is the main component of natural gas, which is an energy source. Methane also poses a complex scientific challenge: it forms through a number of different biological and nonbiological processes under a wide range of conditions. For example, microbes that live in cows’ stomachs make it; it forms by thermal breakdown of buried organic matter; and it is released by hot hydrothermal vents on the sea floor. And, unlike many other, more structurally complex molecules, simply knowing its chemical formula does not necessarily reveal how it formed. Therefore, it can be difficult to know where a sample of methane actually came from. But now a team of scientists led by Caltech geochemist John M. Eiler has developed a new technique that can, for the first time, determine the temperature at which a natural methane sample formed. Since methane produced biologically in nature forms below about 80°C, and methane created through the thermal breakdown of more complex organic matter forms at higher temperatures (reaching 160°C-220°C, depending on the depth of formation), this determination can aid in figuring out how and where the gas formed. A paper describing the new technique and its first applications as a geothermometer appears in a special section about natural gas in the current issue of the journal Science. Former Caltech graduate student Daniel A. Stolper (PhD ’14) is the lead author on the paper. “Everyone who looks at methane sees problems, sees questions, and all of these will be answered through basic understanding of its formation, its storage, its chemical pathways,” says Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry at Caltech. “The issue with many natural gas deposits is that where you find them—where you go into the ground and drill for the methane—is not where the gas was created. Many of the gases we’re dealing with have moved,” says Stolper. “In making these measurements of temperature, we are able to really, for the first time, say in an independent way, ‘We know the temperature, and thus the environment where this methane was formed.'” Eiler’s group determines the sources and formation conditions of materials by looking at the distribution of heavy isotopes—species of atoms that have extra neutrons in their nuclei and therefore have different chemistry. For example, the most abundant form of carbon is carbon-12, which has six protons and six neutrons in its nucleus. However, about 1 percent of all carbon possesses an extra neutron, which makes carbon-13. Chemicals compete for these heavy isotopes because they slow molecular motions, making molecules more stable. But these isotopes are also very rare, so there is a chemical tug-of-war between molecules, which ends up concentrating the isotopes in the molecules that benefit most from their stabilizing effects. Similarly, the heavy isotopes like to bind, or “clump,” with each other, meaning that there will be an excess of molecules containing two or more of the isotopes compared to molecules containing just one. This clumping effect is strong at low temperatures and diminishes at higher temperatures. Therefore, determining how many of the molecules in a sample contain heavy isotopes clumped together can tell you something about the temperature at which the sample formed. Eiler’s group has previously used such a “clumped isotope” technique to determine the body temperatures of dinosaurs, ground temperatures in ancient East Africa, and surface temperatures of early Mars. Those analyses looked at the clumping of carbon-13 and oxygen-18 in various minerals. In the new work, Eiler and his colleagues were able to examine the clumping of carbon-13 and deuterium (hydrogen-2). The key enabling technology was a new mass spectrometer that the team designed in collaboration with Thermo Fisher, mixing and matching existing technologies to piece together a new platform. The prototype spectrometer, the Thermo IRMS 253 Ultra, is equipped to analyze samples in a way that measures the abundances of several rare versions, or isotopologues, of the methane molecule, including two “clumped isotope” species: 13CH3D, which has both a carbon-13 atom and a deuterium atom, and 12CH2D2, which includes two deuterium atoms. Using the new spectrometer, the researchers first tested gases they made in the laboratory to make sure the method returned the correct formation temperatures. They then moved on to analyze samples taken from environments where much is known about the conditions under which methane likely formed. For example, sometimes when methane forms in shale, an impermeable rock, it is trapped and stored, so that it cannot migrate from its point of origin. In such cases, detailed knowledge of the temperature history of the rock constrains the possible formation temperature of methane in that rock. Eiler and Stolper analyzed samples of methane from the Haynesville Shale, located in parts of Arkansas, Texas, and Louisiana, where the shale is not thought to have moved much after methane generation. And indeed, the clumped isotope technique returned a range of temperatures (169°C-207°C) that correspond well with current reservoir temperatures (163°C-190°C). The method was also spot-on for methane collected from gas that formed as a product of oil-eating bugs living on top of oil reserves in the Gulf of Mexico. It returned temperatures of 34°C and 48°C plus or minus 8°C for those samples, and the known temperatures of the sampling locations were 42°C and 48°C, respectively. To validate further the new technique, the researchers next looked at methane from the Marcellus Shale, a formation beneath much of the Appalachian basin, where the gas-trapping rock is known to have formed at high temperature before being uplifted into a cooler environment. The scientists wanted to be sure that the methane did not reset to the colder temperature after formation. Using their clumped isotope technique, the researchers verified this, returning a high formation temperature. “It must be that once the methane exists and is stable, it’s a fossil remnant of what its formation environment was like,” Eiler says. “It only remembers where it formed.” An important application of the technique is suggested by the group’s measurements of methane from the Antrim Shale in Michigan, where groundwater contains both biologically and thermally produced methane. Clumped isotope temperatures returned for samples from the area clearly revealed the different origins of the gases, hitting about 40°C for a biologically produced sample and about 115°C for a sample involving a mix of biologically and thermally produced methane. “There are many cases where it is unclear whether methane in a sample of groundwater is the product of subsurface biological communities or has leaked from petroleum-forming systems,” says Eiler. “Our results from the Antrim Shale indicate that this clumped isotope technique will be useful for distinguishing between these possible sources.” One final example, from the Potiguar Basin in Brazil, demonstrates another way the new method will serve geologists. In this case the methane was dissolved in oil and had been free to migrate from its original location. The researchers initially thought there was a problem with their analysis because the temperature they returned was much higher than the known temperature of the oil. However, recent evidence from drill core rocks from the region shows that the deepest parts of the system actually got very hot millions of years ago. This has led to a new interpretation suggesting that the methane gas originated deep in the system at high temperatures and then percolated up and mixed into the oil. “This shows that our new technique is not just a geothermometer for methane formation,” says Stolper. “It’s also something you can use to think about the geology of the system.” Formation temperatures of thermogenic and biogenic methane, by D.A. Stolper et al. www.sciencemag.org/lookup/doi/… 1126/science.1254509 Note : The above story is based on materials provided by California Institute of Technology
What Are You Doing? ¿Que Pasa? Learning a second language? Crayola® Markers add a FLASH (of color) to your bilingual cards. 1. People all over the world do the same things that you do every day. They use different words to describe these activities. If you’re learning another language, here is a colorful way to build your vocabulary with word games. 2. Cut rectangular cards from file folders with Crayola Scissors. On each card, draw objects that you use or see every day with Crayola Markers. Glue two cards back-to-back with a Crayola Glue Stick to make a two-sided picture card. 3. Cut out smaller cards. Write the word for each picture in your language on one side of each card. Look up how to spell the same word in your second language and write it on the other side of the smaller card. Decorate the edges of your cards with lively borders. 4. Invent your own ways to use these vocabulary study tools. To make a game, you could punch two holes in each two-sided card. Punch one hole in a corner of each of the word cards. Thread string through matching word and picture cards. Tie them together. 5. Check your vocabulary! Add new cards as you learn new words. Adult supervision is required for any arts & crafts project. Observe children closely and intervene as necessary to prevent potential safety problems and ensure appropriate use of arts and crafts materials. Some craft items, particularly beads and buttons, are potential choking hazards for young children. Avoid use of such small parts with children younger than 3 years. Craft items such as scissors, push pins and chenille sticks may have sharp points or edges. Avoid use of materials with sharp points by children younger than 4 years. Read all manufacturers' safety warnings before using arts and craft supplies. Scissors—ATTENTION: The cutting edges of scissors are sharp and care should be taken whenever cutting or handling. Blunt-tip scissors should be used only by children 4 years and older. Pointed-tip scissors should be used only by children 6 years and older. String-Like Materials—Includes string, raffia, lacing, yarn, ribbon, and other similar material. Children 3 years and younger should not be given any string-like material that is longer than 12 inches. Close adult supervision is essential whenever children use string-like material. When crafts are to be worn around the necks of children 8 years and younger, attach the ends of the “string-like material” with clear adhesive tape, which allows easy release of the bond if the craft becomes entangled or caught on equipment. For children older than 8 years, the ends of the “string-like material” may be tied and knotted. - Decorate a box in which to store your ever-growing pack of cards. - Exchange your cards with those made by your classmates. Combine several sets for a challenging game. Quickly move on to verbs, adjectives, phrases, and other parts of speech. - For concrete ideas, review the English/Spanish books by Rebecca Emberley including Let’s Go/Vamos, My House/Mi Casa, Taking a Walk/Caminado. - Assessment: Ask children to check each other’s vocabulary words for spelling and accurate matches.
Head wave movie A charge is detonated in the upper left hand corner generating a pair of expanding rings. The red and blue rings show regions of high and low pressure respectively. The expanding rings hit the ocean bottom. At the point of contact, the energy is split between a reflected wave in the ocean and a transmitted wave in the ocean bottom. The reflected wave is distorted since the phase of the reflection coefficient varies between 0 and 90 degrees depending on the angle of incidence. The transmitted wave preserves its shape but stretches because the sound speed in the bottom is faster. The wave in the ocean bottom travels faster and pulls ahead of the water wave. Energy is continuously shed from the ocean bottom and forms a diagonal band (the head wave=lateral wave=conical wave) connecting the transmitted and reflected waves. Start (requires an mpeg movie player)
Linking Geography and Food - Asia, China - Grades 3-5, Grades 6-8, Grades 9-12 - Social Studies & Geography Students will explore the ways that physical and human geography can contribute to the food culture of another world region. Begin by viewing Amy Throndsen's slide show, A Taste of Tongren, and discussing the central concepts using the accompanying lesson plan, What Can Food Tell Us About a Place?. In the slide show, Amy describes the cuisine of the Guizhou region of China. Using the slide show as a starting point, students will explore the ways that physical and human geography can contribute to the food culture of another world region. - give examples of how physical geography can influence food production - describe how the movement of people into a region can influence cuisine - explain the connection of a specific dish to the geography and culture of its region of origin - Revisit the photos in the slide show, A Taste of Tongren. Have students make observations and inferences about Tongren's climate and geography. Suggested questions: - What landforms do you see? - Do you see any bodies of water or evidence of water? - What foods are grown? What conditions do you think these foods need? - How are people dressed? What does this suggest about the climate? Find Guizhou province and Tongren City on a map. Discuss: - What else do you notice about the region's topography and location (e.g ., latitude, proximity to water bodies, proximity to other countries and regions)? - How might these influence food production and consumption? - Discuss how geography and climate can influence a region's food production and consumption. Give familiar food production examples (e.g., oranges in Florida; corn in the Midwest; grapes in California; lobster in New England) and have students brainstorm additional ideas. How do local climate and geography make the production of these foods possible? - Explain that human factors, like the movement of people and the presence of distinct cultural groups, also play a role in regional cuisine. Consider the past and present immigrant groups in your region. Is there evidence of these cultures in your local cuisine? (e.g., types of foods families prepare; types of foods available in local supermarkets; types of restaurants in your community; types of foods students have tried before). Individually or in groups, have students research food production and cuisine in a selected country, world region, or U.S. region. Ask them to investigate: - How do geography and climate influence the types of foods that are produced? - How do the cultural backgrounds of the people influence local cuisine? Have students share their learning by preparing a dish from their chosen region. When presenting the dish, students should explain: - Which ingredients are produced in the region? - How do climate and geography make the production of these foods possible? - What are the origins and cultural significance of the dish? Frameworks & Standards - Where we live influences how we live. - Both physical and human factors shape a place and its practices. - How does geography play a role in my daily life and in the lives of others? - How does the movement of people influence the culture of a place? - Essential Element II: Places and Regions - Essential Element III : Physical Systems - Essential Element IV: Human Systems - Thematic Strand I: Culture - Thematic Strand VII : Production, Distribution, and Consumption
A bacteriophage is a virus that infects bacteria. A type of bacteriophage is bacteriophage lambda. This specific bacteriophage infects E. Coli. It is composed of protein and double stranded DNA ¡VdsDNA). The DNA of the phage contains around 50,000 base pairs and codes for 50 proteins. At both ends of the DNA of the phage, there are cohesive ends, which are composed of 12 nucleotides. Both ends compliment each other, which makes the DNA circular once together. This circular DNA is usually present in an infected bacterial cell. This protects the DNA to be degraded by the cell. In this laboratory experiment, restriction enzymes were used to analyze the DNA of the lambda phage. Restriction enzymes cut DNA in specific locations of the DNA sequence. The restriction enzymes used were EcoR1 and Bam H1. Both of these restriction enzymes cut DNA into six fragments. Gel Electrophoresis Apparatus 100x Triacetate EDTA Buffer with a pH of 8.0 Methylene Blue Stain Water Bath 37¢XC (Incubator) Water Bath 70¢XC (Incubator) Phage Lambda DNA (uncut) EcoR1- Restriction Enzyme EcoR1 + Bam H1 ¡V Mixture of Restriction Enzymes ¡÷ Preparing the DNA samples In this lab experiment, four small tubes were labeled 1-4. Once labeled, 10£gl of the following material was placed in each of the tubes as shown in Table 1.1: Table 1.1 Sample Placement in small Tubes Name of Sample Eco-R1 Buffer solution EcoR1 + Bam H1 Mixture EcoR1 + Bam H1 Mixture After each of the solutions were put into the tubes, 5£gl of lambda phage DNA was placed into each tube. In order to mix the solutions inside, the tubes were gently tapped. The tubes were then placed into the Water Bath 37¢XC Incubator for 50 minutes. ¡÷ Preparing the Gel Electrophoresis While the tubes are incubating, the gel electrophoresis apparatus was being set up. The concentration of the agarose gel needed is 1.2%. The number of grams needed to make 1.2% of agarose gel in 30mLs of Triacetate EDTA Buffer with a pH of 8.0 was calculated. It was calculated that 0.36 grams of the agarose powder needed to be used. Using the balance, 0.36 grams of agarose powder was weighed and then 30 mL of Triacetate EDTA Buffer with a pH of 8.0 was added to the agarose powder. The mixture of the buffer and powder were then heated in the microwave until the solution was clear (60 seconds). Once the solution was clear, it was then placed into the gel electrophoresis apparatus with the gel comb. The gel was left alone to solidify. When the gel was solid, the gel comb was removed leaving behind the wells. ¡÷ Cont. of Preparation of DNA Samples Once the gel is prepared and the incubation period reached 50 minutes, 5£gl of gel electrophoresis sample buffer (Triacetate EDTA Buffer with a pH of 8.0), was placed into each of the four tubes. Tube #4 was then placed was transferred to the Water Bath 70¢XC (Incubator) for five minutes. When the five minutes have passed, the tube was then placed in the ice bath for a couple of minutes. ¡÷ Gel Electrophoresis 15Ýl of each sample were loaded to the well using a micropipette. Samples and wells are listed below in Table 1.2. Table 1.2 Sample Placement in Wells Name of Sample After the wells were loaded with the samples, the wells were sealed with agarose gel. This prevents the samples from overflowing in the gel. Once this was completed the gel was moved so that the wells were on the negative electrode side. Then 300mL of Triacetate EDTA Buffer with a pH of 8.0 was then added to the electrophoresis apparatus. The wires for the electrophoresis apparatus were then connected to the voltage base; one wire on the negative and the other on the positive. Then cover the gel with the lid and turning on the base to 120 mV. The... Please join StudyMode to read the full document
Although the genus Philautus was discovered in 1822, knowledge of these frogs is still fairly limited due to their small size and great variety of colours (4). Male Philautus frogs typically have internal vocal sacs (6) and the euphonious tinkling sound, which is characteristic of these tiny green and brown frogs, is most often heard during the rainy season (7). Philautus acutirostris has a very unique method of reproduction, as it exhibits direct development. That is, the eggs develop straight into froglets, typically having no aquatic tadpole stage (4). Following copulation, the female shrub frog produces a clutch of 10 to 20 eggs (2). The eggs are usually laid on the ground, under stones or dead leaves, or on the leaves of a fern, small shrub, or tree (4). Such plants are thought to typically include the wild banana plant and epiphytic ferns (2).
It is called generic software and includes databases, spreadsheets, word processing, text handling and draw programmes. And it has become the focus of a national project designed to show how high-level historical thinking can come out of using relatively low-level information technology. The government-funded project found there had been a decline in the use of IT in history, due to the introduction of the national curriculum and changes in the technology available in schools. For instance, simulations, once at the forefront of developments, were being used less and less. The underuse of IT has also been a common complaint of school inspectors. So the project, managed by the Historical Association and the National Council for Education Technology, starting with key stage 3, set out to show how the technology available in schools could be put to better use. The project team found that the generic software programmes can help historians in many ways. Take the teaching of overviews, which has always been difficult. How would you cover a long time span without resorting to a dull litany of details and dates? One solution is to use a database of medieval castles. Pupils can quickly search for patterns of change and continuity, seeing how castles changed from Norman motte and bailey to Henrician concentric gun platforms. The database also makes accessible sufficient examples for pupils to recognise that change neither takes place immediately in one year, nor uniformly across a country. Another solution to outlines is the use of a spreadsheet of trade figures for Britain 1750-1900. Again a quick search for patterns. Why did British trade with countries like the United States or France's noticeably dip at certain dates? This is an opportunity to examine the impact of the American and French Revolutions, while plotting the relative balance of British trade with Africa or Asia enables pupils to chart the development of the British Empire. The ease of search and graphing of spreadsheets makes statistical data accessible and manipulable for Year 9 pupils. Historical causation is another difficult area. The use of word processing, spread-sheet, text-handling or draw programmes allows pupils to manipulate the causes of any historical event on screen. By highlighting, placing into boxes, connecting with lines or linking pages pupils can see how the causes of the English Civil War are connected, how they might be categorised and what relative importance they have. Alternatively, pupils might develop a database of the problems facing Tudor and Stuart monarchs. In the process they would be forced to consider such issues as religion or the difference between a rebellion and civil war. Both these activities provide a base on which extended writing can be developed. At one attainment level this might mean a well constructed essay, at another it might mean a few sentences that constitute an historical explanation. In either instance word processing is an invaluable aid to teachers trying to improve pupils' communication of their knowledge and understanding. It is used not to produce a neat final copy but to draft and redraft an explanation, which pupils would find infinitely more difficult using pen and paper. Site visits are invaluable for pupils but difficult for some schools to achieve. CD-Rom technology can now bring the site into the classroom far more excitingly than photographs can. This makes it possible for pupils to compare the present site with reconstructions. These can be linked on disc with the available written evidence to evaluate reconstruction drawings as interpretations of history. Historical enquiry, in particular pupils framing their own questions, is another area where IT can help. Many teachers have developed databases of historical sources such as census returns, trade directories, soldiers executed in the First World War. The power of the computer has been the swift searching by pupils to test their hypotheses. Were all children under eight scholars? An alternative approach is through a pupil-constructed database which categorises the sources available for study. Do the sources we have about the Romans affect what we know about them? Yes is the answer an examination of such a database suggests. Here the database is not being used to examine one large source but a wide range of sources. On a smaller scale word processing allows easy study of one written source on disc. This can be highlighted, for example, to separate narrative from explanation or fact from opinion. Finally, the most recent development is CD-Rom, where vast quantities of stored information can be searched. Here, as in any enquiry, pupils need to know what they are looking for; they need to frame valid historical questions. For teachers the issue is which CD-Rom to buy. The History and IT Support Project will be publishing one leaflet on CD-Rom to help history teachers make informed choices and another on using IT. Classroom materials, guidance and training will follow. The three project officers, myself, Rob Entwistle, and Ben Walsh can be contacted at the NCET, Milburn Hill Road, Science Park, Coventry, CV4 7JJ. Dave Martin is a history adviser in Dorset
The purpose of this lab is to determine which pigments in a plant support or effect photosynthesis, based on starch production, which wavelengths of light are involved in photosynthesis, and identify plant pigments found in a plant leaf by means of paper chromatography. Life on Earth is dependent entirely on the energy from the Sun, not only to keep the planet at a suitable temperature but also to provide the energy required to sustain life. The energy of the Sun, in the form of photons, is actively captured by chlorophyll and related pigments present in photosynthetic organisms, like plants and algae. This captured energy is used to convert carbon dioxide into complex energy-rich molecules that can be used by themselves or other organisms. “Photosynthesis is the conversion of light energy to chemical energy in the form of sugar and other organic molecules.” (Russell, Wolfe, Hertz, & Starr, 2010). Photosynthesis can be categorized into two main processes: light-dependant reactions and light-independent reactions. For the purpose of this lab, light-dependant reactions will be investigated. The reactants involved in photosynthesis include carbon dioxide, water and sunlight to produce glucose, oxygen, and water. The light reactions involve the capture and use of light energy by pigment molecules to synthesize NADPH and ATP. Plants use this light energy to produce glucose from carbon dioxide. The glucose is stored mainly in the form of starch granules, in the chloroplasts of cells. Glucose in the form of starch is non-polar and is not soluble in water, allowing it to be stored much more compactly. The chloroplast is formed from an outer membrane, an inner membrane, and an intermembrane compartment. The aqueous environment within the inner membrane is called the stroma. Within the stroma is the thylakoids, which are flattened, closed sacs. It is in these sacs that the specific molecules required to carry out the light reactions of photosynthesis are contained, including the pigments, electron transfer carriers, and the ATP synthase enzymes for ATP production. A pigment is able to absorb photons of light and differ by the wavelengths of light they can absorb. The amount of energy in a photon is inversely related to its wavelength. Blue light has a shorter wavelength and consists of photons that have higher energy than the longer wavelength red light. When photons of light hit an object, they can be reflected off the object, transmitted through the object or absorbed by the object. The absorption of light by a pigment results in electrons becoming excited and moving to a higher energy state. Colour is determined by the wavelengths that it cannot absorb, therefore chlorophyll is green since it does not absorb green light. If a pigment absorbs all wavelengths of visible light, the object appears black. A large variety of pigments can be found in plants. The most common are chlorophylls a and b and carotenoids, located in the chloroplasts of cells, and anthyocyanins, located in the cell vacuoles and do not contribute to photosynthesis. Each of these pigments has different properties and performs different functions for the plant, including absorbing light in different parts of the spectrum. The more light absorbed equals the more energy available for a plant. The pigment molecules that can be found in plants are specifically arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts. Each contains a reaction centre surrounded by an antenna complex. Light from the sun travels into the chloroplast and goes through the antenna pigment. The energy trapped by the antenna complex is funnelled to the reaction centre, called P700, where it is used to oxidize a chlorophyll molecule and donate an electron to a primary acceptor molecule to continue into carbon fixation to ultimately release glucose sugar (Oracle ThinkQuest, 2010). The reaction centers are named after the wavelength...

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