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Thawing permafrost in the Arctic is leading to coasts disintegrating into the sea at a rate of up to 22 metres a year in some areas. The large quantities of ice in Arctic coastal soils help to hold the land together, and when temperatures rise the land starts to fall apart. As well as land, archaeological remains and ancient frozen animal bodies and plants are also washed into the sea. The retreat of the coastlines is also flooding shallow Arctic waters with both nutrients and pollutants, scientists say an article in the journal Nature Climate Change. While there is already evidence of how animals such as polar bears are being affected by climate change, very little is known about what effect coastal collapse will have on Arctic marine life. The loss of land and permafrost is also having a profound effect on people's livelihoods in the Arctic. One coast retreating fast is that of Herschel Island off the coast of Canada in the Beaufort Sea. At Herschel, thawed permafrost is collapsing in the form of mudslides, spreading out into the coastal waters in sediment plumes stretching for miles. There is very little data available across Arctic coastlines at the moment, so scientists are using Herschel Island as a model to try to understand what might happen elsewhere. Study author Michael Fritz of the Alfred Wegener Institute's Helmholtz Centre for Polar and Marine Research in Germany says that the island, which retreats by up to 22 metres a year, is a good indicator for how the coasts of other Arctic nations could be faring. Countries that have permafrost coastlines in the Arctic include the US, Canada, Russia and Greenland. "We have very little data at the moment. Only about 2% of the Arctic coasts are actually classified – so for those we know how high the cliff is, what is the sediment, what is the geology, what is the carbon content, what are the nutrients and pollutants in the soil," Fritz told IBTimes UK. As 34% of coasts in the world are permafrost – around 253,000 miles – Fritz said that we can expect to see more mudslides across the Arctic region. "We can until now only guess the implications for the food chain," he said. However, there are several ways that Fritz says it might be affected. The soil from the melted permafrost deposits a large quantity of organic material in the water, which is broken down by microorganisms, releasing more carbon dioxide into the atmosphere. The nutrients released can also fuel the growth of algal blooms, depleting oxygen in the water and potentially killing fish and other sea animals. Fritz and his colleagues are calling for a concerted international effort to study Arctic coastlines. There has been little research on this previously due to the inaccessibility of many of the coasts, and it can be politically challenging to study the area. "The Arctic is inhabited, unlike the Antarctic, and these coasts belong to different countries. And these countries have an interest to have the right and the ownership of the coasts, and to do research but also economic development in those areas," Fritz says. "This can hinder but it can also profit research, so that these areas can be better studied in the future."
- slide 1 of 5 According to the American Cancer Soceity 2008 study, about one in every three women and one in every two men, are likely to have cancer in their lifetime. Cancer is often a devastating disease and many scientists continue to discover the mechanisms of its development, and search for ways to cure it. Studies have shown that genes often play a role in normal body growth and in cancer formation. Examples of these genes are the proto-oncogene and oncogene, respectively. The difference between proto-oncogene and oncogene generally lie in their functions inside the body. - slide 2 of 5 Proto-oncogenes are usually responsible in making proteins which are important in stimulating division of cells, in stopping apoptosis or cell death, and in controlling cell differentiation. These processes are often necessary in the growth and maintenance of body organs and tissues. During embryogenesis, the action of these proto-oncogenes are mostly increased since tissues and organs are continually developing. As their functions are completed, some of these activities are often turned off. There are several classifications of proto-oncogene groups, and these classifications are generally based on their function inside the cell. Examples of proto-oncogenes are receptor tyrosine kinases, growth factors, and membrane associated G-proteins, among many others. From cell growth, through differentiation and during proliferation, these different kinds of proto-oncogenes are usually involved in the process. When these proto-oncogenes undergo mutations, however, they become oncogenes, which are capable of turning normal cells into cancer cells. Mutations are permanent alterations or changes that occur in the sequence of DNA in a given gene, often resulting in the production of a protein that functions differently, like increasing its activity or performance. - slide 3 of 5 Oncogenes are proto-oncogenes that experienced mutation through several possible means. These include deletion and insertion mutations, increased transcription, point mutations, and gene amplification, among others. Viruses can also cause transformation of the proto-oncogene into an oncogene. When these mutations occur, the result is often an increased activity in the affected proto-oncogenes. Cells often divide continually, causing it to increase in numbers, and in the growth of tumor size. There is also increased inhibition of apoptosis that regulate the death of cells naturally. When this happens, cells which are supposed to die, continue to stay in the body. These mechanisms are typical of how cancer develops inside the body. Reactivation of proto-oncogenes that were turned off when their functions were completed, can also cause cancer formation later in life. And those that continue to perform increased activities than necessary may also contribute to the growth of cancer. - slide 4 of 5 The Difference Between Proto-Oncogene and Oncogene Classes Of the two gene classes, the proto-oncogenes are necessary for the proper development of a healthy body. Oncogenes, on the other hand, often promote negative effects inside the cells, thus leading to cancer formation.
What is X-ray? X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 1016 Hz to 3 1019 Hz) and energies in the range 120 eV to 120keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Rntgen radiation, after Wilhelm Conrad Rntgen, who is generally credited as their discoverer, and who had named them X-rays to signify an unknown type of radiation.:1–2 Correct spelling of X-ray(s) in the English language includes the variants x-ray(s) and X ray(s). XRAY is used as the phonetic pronunciation for the letter x. X-rays from about 0.12 to 12 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 12 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays, due to their penetrating abilities. Hard X-rays can penetrate solid objects, and their most common use is to take images of the inside of objects in diagnostic radiography and crystallography. As a result, the term X-ray is metonymically us ed to refer to a radiographic image produced using this method, in addition to the method itself. By contrast, soft X-rays can hardly be said to penetrate matter at all; for instance, the attenuation length of 600 eV (~ 2 nm) x-rays in water is less than 1 micrometer.X-rays are a form of ionizing radiation, and exposure to them can be a health hazard. The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays). Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays. However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually distinguished by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.
What is scoliosis, and what are its symptoms? Scoliosis is the abnormal currative of the spine that results in an “S-shaped” configuration down the back. While many cases of scoliosis can be attributed to congenital conditions, degenerative spinal conditions, or spinal tumors, in most instances have no identifiable underlying cause. For some people, scoliosis produces no symptoms, but, for others, the S-shaped curve could get worse, increasing both back and leg pain. If spinal stenosis or a tumor is also a factor, you could experience weakness. How is it diagnosed and treated? To reach a diagnosis, one of our orthopedists will discuss your pain history and perform a physical exam. Diagnostic scans, such as X-rays, myelograms, MRIs, or CT scans can identify the full degree of your spinal curvature. Annual X-rays can monitor any curve changes over time. Using a brace has proven effective in some pediatric cases. If lower back and leg pain is present, physical therapy or epidural steroid injections can offer relief. But, if additional nerve problems appear or if the curvature progresses rapidly, surgery may be required.
Megaloblastic anemia, the production in the bone marrow of abnormal nucleated red cells known as megaloblasts, develops as the result of dietary deficiency of, faulty absorption of, or increased demands for vitamin B12 or folic acid. When such a vitamin deficiency occurs, bone marrow activity is seriously impaired; marrow cells proliferate but do not mature properly, and erythropoiesis becomes largely ineffective. Anemia develops, the number of young red cells (reticulocytes) is reduced, and even the numbers of granulocytes (white cells that contain granules in the cellular substance outside the nucleus) and platelets are decreased. The mature red cells that are formed from megaloblasts are larger than normal, resulting in a macrocytic anemia. The impaired and ineffective erythropoiesis is associated with accelerated destruction of the red cells, thereby providing the features of a hemolytic anemia (caused by the destruction of red cells at a rate substantially greater than normal). Vitamin B12 is a red, cobalt-containing vitamin that is found in animal foods and is important in the synthesis of deoxyribonucleic acid (DNA). A deficiency of vitamin B12 leads to disordered production of DNA and hence to the impaired production of red cells. Unlike other vitamins, it is formed not by higher plants but only by certain bacteria and molds and in the rumen (first stomach chamber) of sheep and cattle, provided that traces of cobalt are present in their fodder. In humans, vitamin B12 must be obtained passively, by eating food of an animal source. Furthermore, this vitamin is not absorbed efficiently from the human intestinal tract unless a certain secretion of the stomach, intrinsic factor, is available to bind with vitamin B12. The most common cause of vitamin B12 deficiency is pernicious anemia, a condition mostly affecting elderly persons. In this disorder the stomach does not secrete intrinsic factor, perhaps as the result of an immune process consisting of the production of antibodies directed against the stomach lining. The tendency to form such antibodies may be hereditary. Patients with pernicious anemia are given monthly injections of vitamin B12. Oral treatment with the vitamin is possible but inefficient because absorption is poor. Other forms of vitamin B12 deficiency are rare. They are seen in complete vegetarians (vegans) whose diets lack vitamin B12, in persons whose stomachs have been completely removed and so lack a source of intrinsic factor, in those who are infected with the fish tapeworm Diphyllobothrium latum or have intestinal cul-de-sacs or partial obstructions where competition by the tapeworms or by bacteria for vitamin B12 deprives the host, and in persons with primary intestinal diseases that affect the absorptive capacity of the small intestine (ileum). In these conditions, additional nutritional deficiencies, such as of folic acid and iron, are also likely to develop. Blood changes similar to those occurring in vitamin B12 deficiency result from deficiency of folic acid. Folic acid (folate) is a vitamin found in leafy vegetables, but it is also synthesized by certain intestinal bacteria. Deficiency usually is the result of a highly defective diet or of chronic intestinal malabsorption as mentioned above. Pregnancy greatly increases the need for this vitamin. There is also an increased demand in cases of chronic accelerated production of red cells. This type of deficiency also has been observed in some patients receiving anticonvulsant drugs, and there is some evidence that absorption of the vitamin may be impaired in these cases. Often several factors affecting supply and demand of the vitamin play a role in producing folic acid deficiency. Unless folic acid deficiency is complicated by the presence of intestinal or liver disease, its treatment rarely requires more than the institution of a normal diet. In any event the oral administration of folic acid relieves the megaloblastic anemia. Some effect can be demonstrated even in pernicious anemia, but this treatment is not safe because the nervous system is not protected against the effects of vitamin B12 deficiency, and serious damage to the nervous system may occur unless vitamin B12 is given. In addition to the above conditions, megaloblastic anemia may arise in still other situations. Selective vitamin B12 malabsorption may be the consequence of a hereditary defect. Deranged metabolism may play a role in some instances of megaloblastic anemia that accompany pregnancy. Metabolic antagonism is thought to be the mechanism underlying the megaloblastic anemia associated with the use of certain anticonvulsant drugs and some drugs employed in the treatment of leukemia and other forms of cancer. In fact, one of the earliest drugs used to treat leukemia was a folic acid antagonist.
Definition - What does Bond mean? A bond is a form of debt investment in which individual or institutional investors loan money to an organization or the government for a fixed or variable rate of interest. The duration of the investment is for a pre-agreed upon period of time. When investors buy a bond, they enter into an agreement with the corporation that is issuing it, also called the issuer. In this agreement, the issuer promises to repay the agreed rate of interest as well as the principal within the stipulated time frame. Investors who have bought these bonds are bondholders or creditors of the organization. Divestopedia explains Bond Bonds are issued by government or private entities when they want to raise money to finance new projects, manage existing ones or to refinance existing debts. They take this option instead of borrowing money from banks because the latter may require some form of collateral as security. In return, the issuer pays a certain amount of interest to the investor with a payout, usually semi-annually. The rate of interest for the bond depends on two main factors: the duration of the bond and the credit quality. In general, if the issuer's credit is poor, then the interest rate tends to be high because the chances for default is high. Bonds with longer maturity dates also carry higher interest because they have lower liquidity and the chances for default are high. There are many types of bonds available, depending on the issuer. Some well-known types of bonds include U.S. government securities, corporate bonds, municipal bonds, asset-backed securities and mortgage-backed securities. Each of these bonds come with their own advantages and disadvantages, so it is up to the investor to analyze them before investing. From an investors' perspective, bonds offer the balance needed in an investment portfolio. Most financial experts recommend that investors have a balance between cash, stocks, bonds and assets in order to mitigate potential financial losses. This is why bonds have been traditionally used to plan towards specific financial objectives such as college education or retirement.
German vs. Italian nationalism - The French Revolution as a model of inspiration. - Other aspects of Napoleon's rule. - A dual strain of nationalism. - Vienna territorial arrangements in both Italy and Germany. - The great Italian revolutionary, Mazzini. - The geographic spread of where and to what extent constitution was granted. - The formation of economic unions. - The lack of a general popularization of ideas. - Two fundamental weaknesses of nationalism. - Tuscany as an examples of how nationalism became radical. - Reliance on external developments. Indeed, in tracing the development of nationalism in the early 19th century, we are confronted with the inherent weaknesses of division, particularism and mass indifference; dubious motives of ?nationalists' and oft-yieldless attempts to surmount forces of repression- to the point that it is questionable at some stages, if genuine nationalism even existed at all. Nationalism is essentially the belief that people who share a common language, culture or history should be brought together to form a nation-state; the desire of a community to assert its independence and uniqueness from another. Since in Italy and Germany we refer to integrated nationalism, the desire for unification would then invariably be a prerequisite of a nationalist. In the spirit of discussion, we shall not assume the most stringent definitions of a nationalist- this implies not discrediting one wholly based on what type of unity was craved. [...] The fact that particularism, the antithesis to the idea of a single nation, remained such a veritable thorn in the flesh indicated that nationalism still had a way to go in really infusing the population's mindsets. This brings us to the next stumbling block: the lack of a general popularization of ideas. The middle class liberals had always faced a difficulty in reaching out to the urban artisans and peasant majority, failing enormously in any attempts (if at all) to make the nationalist platform popular and accessible to the masses. [...] [...] In a sense, perhaps Italian nationalism seemed to have received more encouragement from Napoleon than German nationalism did, because it was more in Napoleon's political interest to do so for the former. Italian was promoted as a national language- an attempt to justify Napoleon's presence and mitigate hostility towards his rule. In Germany where Napoleonic rule was shorter, there was no such promotion of nationalist thinking; instead Napoleon was more intent on ?sidetracking the German spirit?. Hence, by 1815 there was the emergence of two kinds of nationalism: liberalism nationalism and romantic nationalism. [...] [...] It is interesting to note that, eventually it is the moderate Norths of Piedmont and Prussia that take the lead in the unification of Italy and Germany- perhaps an indication that the achievements at the end of Italian and German unification were of a moderate nature. There were non-political causes that led to the rise of nationalism, the most significant of which was economic. Cynically speaking, nationalism demonstrated at times to be so spurred on by economic factors, that the true nature and motivations of some nationalist movements can be thrown into doubt. [...]
This section contains free e-books and guides on Basic Algebra, some of the resources in this section can be viewed online and some of them can be downloaded. A Treatise on AlgebraCharles SmithOnline \| NA Pages This book covers the following topics: Multiplication of monomial expressions, Factors found by rearrangement and grouping of terms, Bemainder Theorem, Discussion of roots of a quadratic equation, Irrational equations, nationalizing factors, Radix fractions, General convergent, Reduction of quadratic surds to continued fractions, Theory op Numbers, Congruences, Multiplication of determinants. The First Steps in AlgebraG. \| 269 Pages This book is written for pupils in the upper grades of grammar schools and the lower grades of high schools. The introduction of the simple elements of Algebra into these grades will, it is thought, so stimulate the mental activity of the pupils, that they will make considerable progress in Algebra without detriment to their progress in Arithmetic, even if no more time is allowed for the two studies than is usually given to Arithmetic alone. Beginning and Intermediate AlgebraTyler WallacePDF \| 489 Pages Beginning and Intermediate Algebra is an open source book written by Tyler Wallace. This book covers the following topics: Pre-Algebra, Solving Linear Equations, Inequalities, Systems of Equations, Graphing, Polynomials, Factoring, Quadratics, Rational Expressions, Functions and Radicals. Philosophy and Fun of AlgebraMary Everest BooleOnline \| 56 Pages This note covers the following topics: From Arithmetic To Algebra, The Making of Algebras, Simultaneous Problems, Partial Solution: Elements of Complexity, Mathematical Certainty, The First Hebrew Algebra, The Limits of the Teacherís Function, The Use of Sewing Cards, The Story of a Working Hypothesis, Macbethís Mistake, Jacobís Ladder.
Ultraviolet radiation, skin type and skin cancer Skin cancer, including basal cell carcinoma,squamous cell carcinoma, and melanoma, is the mostcommon form of cancer, particularly in fair-skinnedpopulations. Ultraviolet radiation, most often in the form ofsunlight, is the major causative agent for skin cancer.Individuals who tend to develop sunburns or havesusceptible pigmentary characteristics, such as a faircomplexion or freckles, are at a higher risk for developing skincancer. The use of sunscreens or sun-protective clothing, andavoidance of midday sunlight and tanning beds are skincancer prevention strategies, although the prevalence ofthese behaviours is low. Effective prevention campaigns,exemplified by Australia’s model, include interventions at thesocietal, community, and individual levels.
The Frozen Alphabet Learn letters, explore, and play with "The Frozen Alphabet"! All you need to get started are letters and water. What You'll Need - or slotted spoon or tongs How We Did It To prepare for "The Frozen Alphabet", put one plastic letter in each part of the ice cube tray or in a small container, fill it with water, and freeze. The plastic letters wanted to float so I pushed them down in the tray and the container as much as possible. I filled our sand table with water and dumped the letter ice cubes in. If you don't have a sand or water table you can use a large container filled with water or even a small baby pool. Grab the letters with your hands, a slotted spoon, tongs, or a net. If they were still frozen, N had to put it back and look for a new one. She felt sorry for the letters all frozen in those ice cubes and decided she wanted to help them escape. As you help each letter escape its cube, say the letter and/or letter sound and transfer it to "safety" (a bowl or tray). She was so happy to rescue the letter M for me! To put a twist on this activity, fill your water table or container with ice and just a little water and hide the letters in the ice. Your child can explore and dig through the cold cubes to find the letters.
Researchers shine light on cool substance Cool science For the first time, scientists have found a way of studying Bose-Einstein Condensates without destroying them. The method, reported in the New Journal of Physics, will allow researchers to examine the properties of Bose-Einstein Condensates, which are clouds of atoms cooled to temperatures of just 100 nano-Kelvin above absolute zero. At such cold temperatures, atoms lose their individual identity and behave as a single macroscopic entity. Little movement can occur, making Bose-Einstein condensates ideal for probing atomic structure. Studying these exotic substances will allow scientists to carry out fundamental research in new fields including atom lasers to precisely measure gravity, and models to study the emission of Hawking radiation from black holes. Until now, it's been impossible to measure and control Bose-Einstein Condensates simultaneously. Using even a single photon of light to study them can heat them up enough to destroy them. "Our new method uses a feedback mechanism which prevents the act of observing the Bose-Einstein condensate from destroying it," says one of the study's authors, Dr Joe Hope of the Australian National University in Canberra. Solar system model Most people picture an atom as a little version of the solar system, with a nucleus in the centre and electrons orbiting around it. "That's a good approximation for everyday life, but when we look closer, we discover that they're actually waves. That's the theory around quantum mechanics," says Hope. "When they get that cold, the fact that they're not particles but waves, becomes important, because they all slide into the same quantum state, becoming one big wave." Scientists wanting to study these properties are hampered by the frailty of condensates. "It's like taking a snap shot of everyone in the room, with the flash was so bright, that everyone runs away, preventing you from taking another picture," says Hope. "So you get a single snapshot of a moment in time, but to get another, you have to find everyone and start again." Hope and colleagues needed to determine if there was a way to keep cooling the condensate to compensate for the heating that was occurring while it was being studied. "We've found we could get a net cooling effect, but had to design it very carefully," says Hope. "It's a feedback mechanism, providing information about changes to the condensate which is constrained by a laser or magnetic trap, which adjusts its shape and position tens of thousands of times a second to compensate." A Bose-Einstein Condensate is created by firing photons of laser light at the target atoms at lower frequencies that those of the atom, causing the light to pass by without affecting it. If the atom moves towards the laser, the frequency changes through Doppler shifting until the two resonate pushing the atom back. By surrounding the atom with lasers on all sides, it can be slowed down causing it to lose most of its energy, through laser cooling. The remaining heat is removed by evaporation, as hot atoms move away, leaving only colder ones behind, a process which can lose over 99.9 per cent of all atoms in the condensate. "We're now working on a method of removing the evaporation process completely, using only the trap feedback and laser cooling to reach condensate temperatures," says Hope.
Like light, sound travels through the air in waves, but unlike light, sound is not made of lots of tiny particles. How sound works When something makes a sound, like you clapping your hands, it’s because when you clapped your hands that shook the air molecules around your hands and made them vibrate (that means they shake quickly back and forth). This vibration, in turn, shook the air molecules a little further away from your hands, and they shook the air molecules next to them, and so on, until the air molecules inside your ear were vibrating too (and inside the ears of the people sitting near you too). When the air molecules inside your ear begin to shake, they wobble tiny hairs inside your ear that are connected to nerves under your skin. If your ears are working, these nerves then send messages to your brain to tell you that you heard a noise. Movement of sound Because sound has to move molecules in order to travel, it’s impossible for sound to move through space, where there are very few molecules. Space is a very quiet place. But sound doesn’t have to move through air – it can just as easily move through water, or through metal wires. In fact, sound moves faster through water than it does through air. But whether in air or in water, sound moves much more slowly than light does. While light travels at 186,000 miles per second, sound only goes 343 metres per second, or about 770 miles per hour. A fast airplane can go faster than the speed of sound. Because of this, you often hear things long after you saw them. For instance, you have to wait to hear thunder after you see lightning in a storm, even though they’re the same thing. - The movement of the air molecules in waves is a bit like ocean waves – the bigger the waves the more powerful they are – and the louder the noise! - Sound waves can’t travel when there isn’t any air so that’s how we know space is silent. - If you listen to loud music you could damage the sensitive hairs that make sense of sound waves that hit your ear drum – so turn it down! Check out some more fascinating facts about sound…
Both Earth and Mars currently have oxidizing atmospheres, which is why iron-rich materials in daily life develop rust (a common name for iron oxide) during the oxidation reaction of iron and oxygen. The Earth has had an oxidizing atmosphere for approximately two and a half billion years, but before that, the atmosphere of this planet was reducing – there was no rust. The transition from a reduced planet to an oxidized planet is referred to as the Great Oxidation Event or GOE. This transition was a central part of our planet’s evolution, and fundamentally linked to the evolution of life here – specifically to the prevalence of photosynthesis that produced oxygen. Planetary geologists at HKU have discovered that Mars underwent a great oxygenation event of its own – billions of years ago, the red planet was not so red. The discovery was published recently in Nature Astronomy in a paper led by research postgraduate student Jiacheng LIU and his advisor Associate Professor Dr. Joe Michalski, both affiliated with the Research Division for Earth and Planetary Science and Laboratory for Space Research. The researchers used infrared remote sensing and spectroscopy to measure the molecular vibration of the material on the Martian surface from orbit, in order to reveal the mineralogy and geochemistry of ancient rocks on Mars. Through detailed comparisons of infrared remote sensing data and data collected in the laboratory here on Earth, the team showed that ancient rocks on Mars exposed at the surface had been weathered under reducing conditions, indicating a reduced atmosphere did exist. Many people are aware that Mars is cold and dry now, but ~ 3.5 billion years ago, it was warmer and wetter. It was warm enough to allow the formation of river channels, lakes, and minerals that formed by interaction with water. Scientists who have used mathematical models to constrain the conditions of an early Martian atmosphere, have concluded that greenhouse warming occurred, but they also concluded from their models that the greenhouse must have included reduced gases rather than carbon dioxide, implied that a reducing atmosphere might have existed. Yet until now, there has not been any evidence that the reduced atmosphere of early Mars actually occurred. This work indicates that it did exist. This project involved detailed infrared remote sensing of Mars, using infrared spectroscopy to map minerals in exposed, weathered rock units. The work was built on detailed analysis of weathered volcanic rocks in Hainan Island in southwestern China, where thick sequences of basalt, similar to volcanic rocks on Mars occur. Jiacheng Liu analyzed the altered rocks systematically using infrared spectroscopy in the laboratory and produced a paper on that research published recently in Applied Clay Science. “Jiacheng has carried out a truly excellent PhD project, built on careful analysis in the laboratory and application of those laboratory results to remote sensing of Mars,” Dr. Michalski commented, “Jiacheng has built on his detailed work on samples from Hainan Island to show that similar mineralogical trends occurred in rocks on Mars.” Assistant Professor Dr. Ryan MCKENZIE from Research Division for Earth and Planetary Science is also impressed by these findings. “This is a rather remarkable study with findings that will significantly impact how we understand the early evolution of terrestrial planets and their surface environments. The transition from a reducing to oxidizing atmosphere on Earth ~2.5 billion years ago was only possible because of the existence of life, as oxygen is a waste product of metabolic processes like photosynthesis. Without microbes producing oxygen, it would not accumulate in our atmosphere, and we could not be here. While there are certainly differences in the local conditions Mars and Earth have been subjected to during their evolutionary histories, my mind can’t help but start thinking about what Jiancheng’s results may mean for a potential early Martian biosphere,” Dr. McKenzie remarked. As China’s first mission to Mars Tianwen-1 is underway – has successfully arrived in Mars orbit on February 10 and set to land on Mars in May 2021, scientists are preparing for an exciting year of Mars exploration and discovery. This work demonstrates how spectroscopy and remote sensing lead to fundamental discoveries of significant importance for understanding Mars’ history. As we begin to understand the most ancient history of Mars, researchers are ready to directly search of any signatures that life might have once existed on ancient Mars, and HKU plans to be at the center of this great scientific adventure. Reference: “Anoxic chemical weathering under a reducing greenhouse on early Mars” by J. Liu, J. R. Michalski, W. Tan, H. He, B. Ye and L. Xiao, 11 February 2021, Nature Astronomy. About the Research Division for Earth and Planetary Science and the Laboratory for Space Research at HKU The Research Division for Earth and Planetary Science and the Laboratory for Space Research specializes in applications of traditional Earth and environmental science techniques and skills for modern space science challenges. Dr. Joe Michalski operates the Planetary Spectroscopy and Mineralogy Laboratory at HKU and is the Deputy Director of the Laboratory for Space Research.
Predictive coding of spoken words in human auditory cortex In a recent MEG study by Pierre Gagnepain, Rik Henson and Matt Davis we show how the brain achieves incredible speed and accuracy in recognising speech. The study published on 10th April 2012 in Current Biology shows that the brain is constantly using knowledge of familiar words to predict what speech sounds will be heard next. Matt Davis explains: "Many of us are familiar with using predictive texting on mobile phones – these systems try to guess what you want to say to save you the trouble of typing it. What we've shown is that the human brain uses a similar, but more sophisticated form of prediction in making sense of speech. The Superior Temporal Gyrus, a part of the brain involved in hearing, is constantly predicting what sounds will come next when listening to speech. So, having heard the syllable 'form...' rather than trying to guess whether the word is 'formal', 'formidable' or 'formula', the brain predicts which sounds would come next if each of these words were said. By predicting which sounds will be heard, the brain can respond to incoming speech extraordinarily quickly." Full details of the paper can be found here: Gagnepain, P, Henson, R. N. & Davis, M.H. (2012) Temporal predictive codes for spoken words in human auditory cortex. Current Biology, 22(7), 615-622. PDF. Supporting Information. The picture below, generated by Simon Strangeways, illustrates predictive coding as a neural mechanism that allows listeners to use knowledge of familiar words and their constituent sounds when understanding speech. Each speech sound is a star and familiar words are constellations. A human listener predicts future sounds when listening, so as to recognise the constellation ("formula") once the sequence of sounds ("formu...") uniquely identifies a single word. Iain DeWitt has spotted an error with equation (3) in the paper. The division by p(speech) is incorrect and should excluded. Thanks to Iain for his careful reading of the paper.
The region that is now Northern Ireland was long inhabited by native Gaels who were Irish-speaking and Catholic. It was made up of several Gaelic kingdoms and territories, and was part of the province of Ulster. During the 16th century English conquest of Ireland, Ulster was the province most resistant to English control. In 1788, the Treaty of Breda was signed between the English and the Irish, ending the English rule in Ireland. About Northern Ireland in brief Northern Ireland was created in 1921, when Ireland was partitioned by the Government of Ireland Act 1920. The majority of Northern Ireland’s population were unionists, who wanted to remain within the United Kingdom. Meanwhile, the majority in Southern Ireland were Irish nationalists and Catholics who wanted a united independent Ireland. In the late 1960s, a campaign to end discrimination against Catholics and nationalists was opposed by loyalists. This unrest sparked the Troubles, a thirty-year conflict involving republican and loyalist paramilitaries and state forces. The 1998 Good Friday Agreement was a major step in the peace process, including paramilitary disarmament and security normalisation. Northern Ireland competes separately at the Commonwealth Games, and people from Northern Ireland may compete for either Great Britain or Ireland at the Olympic Games. In many sports, the island of Ireland fields a single team, a notable exception being association football. The region that is now Northern Ireland was long inhabited by native Gaels who were Irish-speaking and Catholic. It was made up of several Gaelic kingdoms and territories, and was part of the province of Ulster. During the 16th century English conquest of Ireland, Ulster was the province most resistant to English control. In 1607, the lands were confiscated by the Crown and colonized with English-speaking Protestant settlers from Britain. The rebels of 1641 began an anti-Catholic discrimination,governance, and roll back the Plantation. It developed into the wider Wars of the Three Kingdoms, which ended with the English Parliament’s conquest of Limerick in 1715. Many more Scots migrated to Ulster during the Scottish famine of 1690, and are still celebrated by some Protestants in Northern Ireland. The Protestantism of the 1690s led to the Battle of Derry and Battle of Boyne and the creation of the Ulster-Scots. In 1788, the Treaty of Breda was signed between the English and the Irish, ending the English rule in Ireland. This led to a series of wars between the two countries, including the First and Second World Wars. The Treaty was signed in 1798, and the Treaty was later amended to end the Second World War. The treaty was signed by the British and Irish governments, with the British taking control of the Irish Sea. The Irish Sea was the last part of Ireland to become part of Britain in 1829. The British government took control of Ireland in 1922, and later the Irish Free State in 1922. The United Kingdom and the Republic of Ireland share a border to the south and west with Northern Ireland, and share a population of 1,810,863. The Northern Ireland Assembly holds responsibility for a range of devolved policy matters, while other areas are reserved for the British government. Today, the former generally see themselves as British and the latter generally see itself as Irish, while a Northern Irish or Ulster identity is claimed by a large minority from all backgrounds. In 2011, Northern Ireland constituting about 30% of the island’s population and about 3% of UK’s population.
Measurement is one of my most favorite math concepts to teach. Put a ruler in the hands of a student and they are as happy as a peach! When Hope and I were putting together our 2nd Grade math unit on measurement we really wanted to make sure to pull together activities that were hands-on and engaging. We also wanted to incorporate several skills in such as estimating, comparing, adding & subtracting, and more! Here’s a little look at our favorite activities from Magic of Math Unit 6: Students will create a robot then estimate and measure using inches. Students create a City-Scape and estimate/measure the height of each building. Afterwards students compare the heights of different buildings. Students will also use a ruler to measure the lengths of different lines. During Spin, Move, and Measure students decide which unit of measurement would be best to measure in. Students also measure several of the objects that can be found around the classroom. Using small cars, our friends will host a Meter Derby to measure the length their cars travel using meters. Students also take a peek at Wacky Line Ups! These pictures will give students a chance to measure objects that aren’t lined up perfectly on a ruler. Building Lego Towers will give our friends an opportunity to estimate and measure using centimeters. We will also work on comparing lengths in centimeters with a little Twizzler Station activity! Students are always trying to sneak a little paper airplane making into their day, so why not give them the opportunity to do so?! Paper airplanes will take flight and students will have a blast estimating and measuring! One of our other skills to master is measuring the area of a rectangle. This also includes partitioning rectangles into equal parts. Students create their very own dream room and measure the area of each object that they include! Want an excuse to break out the chocolate?! Using a Hershey’s bar, students will partition rectangles and find the area of each new shape using their candy bar 🙂 We provide many opportunities for students to practice covering a shape appropriately to find the area of different sized rectangles. We just couldn’t leave out the cuteness! Students create a dinosaur and estimate/measure the area of each part. Your little learners will become Area Royalty after they create their very own Area Crowns! Let’s just face it, word problems can be such a bore, but goodness they are important! We did try to take the pain out of it with different ways to attack those tricky things! You can find all of the activities shown above HERE… plus there are SOOOO many more that we didn’t even show 🙂 As a little added bonus, I put together this Measurement Review that can be used after your students have learned how to measure length. This can be displayed on the projector or used as a Scoot activity! Find this freebie HERE! Need one more measurement activity to add to your teacher tool chest? Click HERE to read all about a student-favorite… The Measurement Olympics!
Scientists report (see AAAS report, Wired article or actual research) that they are now able to refract or focus gamma rays. Contrary to theory, they have discovered that gamma rays can be deflected by the nucleus of a silicon atom. Down a bit in the article they said that the mystery deflecting gamma rays seems to be the creation of “virtual electron” electron&anti-electron pairs in the nucleus. The deflection is something ~1.000000001 not much yet, but the belief is that even heavier elements such as gold will refract gamma rays even better. Gamma-ray and gamma ray bursts are typically evidence of extremely energetic explosions witnessed in distant galaxies. They are the most luminous electromagnetic events in the universe. Most gamma ray bursts are released during supernova explosions when a star violently collapses. But what can you do with Gamma ray optics? The possibility of gamma ray optical systems introduces a whole new way of looking at the universe. For example, the introduction of x-rays in the early 1900s created an entirely new way to see inside the human body, never before possible. It’s unclear what gamma ray optics or a G-ray machine will do for medicine or human health but it’s certain that such devices will be better able to “see” processes and objects impossible to detect today. One item of interest was the promise that someday, gamma ray optics will be able to render harmless, radioactive isotopes such as nuclear waste. Somehow a focused gamma ray beam at the proper (neutron binding energy) wavelength could be used to “evaporate” or remove neutrons from an atomic nucleus and by doing so render it less lethal. How this works on Kg of material versus a single atom is another question. Also, gamma ray optics could be used in the future to potentially create designer radioactive isotopes for medical diagnostics and therapy. Even higher resolution nuclear spectroscopy is envisioned by using gamma ray optics. I don’t know about nuclear waste, but if gamma ray optics could transmute lead into gold, we might have something. This probably means that someday, gamma ray optics will be able to store information in an atomic nucleus and that would certainly take data density out of the magnetic domain altogether.
Mindfulness means being in the present moment. Noticing the own thoughts without judging or attaching to them. It is about being compassionate to yourself and others. Also, it is about accepting the current state and being able to let go. Mindfulness was first introduced in the 1970s to help people who suffer from chronic pain, but there are various things mindfulness can help us with. In today’s world, with the technology helping us in many ways, it also leads to more stress, because people expect shorter respond rates and short times to finish projects. Many people forget about themselves and their own needs. They are not aware of their thoughts and emotions which can lead to burnout and panic attacks. The stress levels are high and the fear of failure or losing a job/project because of a competitor is big. “Your vision will become clear only when you can look into your own heart. Who looks outside, dreams; who looks inside, awakes.” – Carl Jung Mindfulness can help to balance the left and right side of the brain – the more rational, logical part and the emotional, artistic part. Also, it helps is to stay calmer in stressful situations – for example during traffic or in meetings. Instead of letting the amygdala react for us in a stressful situation within only 30ms and getting angry, we are able to use the rational part in our brain which usually takes about 100ms to decide. With practicing mindfulness we can even make this process longer to 250ms. It helps us to stay calmer and instead of reacting we are able to respond. This means, in the long run, we are less stressed and more balanced. “Between stimulus and response there is a space. In that space is our power to choose our response. In our response lies our growth and our freedom.” – Victor Frankl But mindfulness cannot only help with these parts in life. It can even help people suffering from depression, chronic pain or ADHD. MRI tests prove that when practicing mindfulness for about 8 weeks the pain can be reduced by 75% and when practicing mindfulness on a longer term, the pain can be reduced even more. If suffering from depression, mindfulness can reduce the risk of relapse. To notice the benefits of mindfulness, it needs regular practice to rewire the brain (neuroplasticity). There are two types of ways to practice mindfulness, the informal and the formal way. The formal way is through meditation and the informal way can be practiced during the daily life. For example, by doing tasks mindful: being fully present at the moment and whenever thoughts come up you can notice them without judging and then letting them go. Like a cloud in a blue sky or a leaf floating on a river. Whenever you notice being distracted by thoughts, you can get yourself back in the present by using your senses: What do you feel? What do you smell? What do you see? What do you hear? The attitudes of mindfulness are non-judging, being patient and curious (“a beginners mind”), trust, non-striving, acceptance, and letting go. This is why I believe, mindfulness can even help us with bigger things: like aggression or distrust against foreigners, other countries and religions. “The real question is not whether life exists after death. The real question is whether you are alive before death.” – Osho
When salt is mixed with water, the salt dissolves because the covalent bonds of water are stronger than the ionic bonds in the salt molecules. Formation of ions At the molecular level, salt dissolves in water due to electrical charges. Both water and salt compounds are polar, with positive and negative charges on opposite sides in the molecule. The bonds in salt compounds are called ionic because they both have an electrical charge—the chloride ion is negatively charged, and the sodium ion is positively charged. Likewise, a water molecule is ionic in nature. Still, the bond is called covalent, with two hydrogen atoms both situating themselves with their positive charge on one side of the oxygen atom, which has a negative charge. - The positively charged side of the water molecules is attracted to the negatively charged chloride ions. The negatively charged side of the water molecules is attracted to the positively charged sodium ions. - Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together. - After the salt compounds are pulled apart, the sodium and chloride atoms are surrounded by water molecules. Once this happens, the salt is dissolved, resulting in a homogeneous solution.
In the 1800 s, John Dalton proposed the first atomictheory. Since then, scientists have learned much more aboutthe structure of an atom, and therefore the atomic theoryhas changed. Dalton had to have a basis for his ideas about atoms. The first law he based his ideas on was the law orconservation of mass. This theory was discovered by Frenchchemist Antoine Lavoisier. He was the first to corectlydemonstrate how something burns. The law basically saysthat atoms can t be destroyed or divided, they havedefinite mass, and the total mass should be the same afterand before a chemical reaction takes place. Another theoryDalton based his works on was the law of definiteproportions. This law was discovered by another FrenchChemist, Joseph Proust. In 1799, he showed that teh;proportion of mass of elementsw in a given compouind willalways be identical. Dalton felt that with his atomictheory, together with these theorys, gave strong proof forthe exsistance of atoms. Dalton s theory stated that all elements are made ofatoms, indestructible parts, the smallest parts of allatoms. He also stated that all elemnts are exactly the sameand compounds are formed by joining together two or moreatoms. This first atomic theory, however, was not excactlycorrect. There are many ideas along the way that helpedform the new atomic theory as it is today. The first ideathat helped contradict Dalton s theory was provided by William Crookes. In the 1870 s, Crookes created a Crookestube, which pumps out high voltage which is applied to twoelectrodes. The opposite of the glass tube is turnedyellow. If an object is placed in the middle of the tube,the shape of the object is on the other side of the tube. This suggested that there are particles smaller than atoms, because electricity is not an atom, and that s what producedthe yellow shadow at the end of the glass tube. Another new law that caused the further contradictionof Dalton s theory was Rutherford s model of an atom. Rutherford s experiment showed clearly that every atom has apositively charged center. Rutherford first believed thatthe positively charged helium atoms were called alphaparticles. With further experimentation, he reliezed thatnot only did atoms have a positively charged center, but amostly empty exterior from the center (nucleus), that alsohad negativly charged rather small particles (electrons orbiting the nucleus. However, Rutherford s model did have flaws. Forinstance, in his model, if electrons orbited the nucleus, then the electrons would lose energy and spiral in towardsthe nucleus. Danish physicist Niels Bohr made improvementon faults like these in Rutherford s model. In Bohr smodel, electrons do not lose energy when orbiting andtherfore do not spiral in toward the nucleus. Another newfactor in Bohr s model is energy levels. Electrons orbitaround energy levels. In each energy level, the fartheraway the level from the nucleus, the more energy anelectron. In Bohr s model, the only way an electron canloose energy is by dropping an energy level, or moving onemore energy level closer to the nucleus. At the lowestenergy level, electrons can not lose energy because they areat a ground state, they can not move any lower. Another important theory is the quantum theory. Hundreds of years ago, during the 1600 s, there was adebate on wether light travels in waves or in particles. Then, in 1864 the idea that light travels in waves was onceagain brought to attention. In the early 1900 s, Max Planckrevived the theory of particles. Planck did experimentsthat could only be explained if light traveled in particles, what he called quanta. How much energy each quanta haddepended on what color the light is. The quantum theorystates that quanta, the fundamental unit of light, travelsin discreet packets.
When it comes to the underwater world, there are countless creatures that captivate our attention. One such creature is the Freshwater Tiger Moray Eel. With its striking appearance and unique characteristics, this eel is a true marvel of nature. In this blog post, we will explore the fascinating world of the Freshwater Tiger Moray Eel and uncover some interesting facts about this elusive species. What is a Freshwater Tiger Moray Eel? The Freshwater Tiger Moray Eel, scientifically known as Gymnothorax polyuranodon, is a species of eel that belongs to the Muraenidae family. Unlike its saltwater counterparts, this eel inhabits freshwater environments, such as rivers and lakes, in Southeast Asia. It is known for its vibrant coloration, which consists of dark green or brownish-black spots on a yellowish background, resembling the stripes of a tiger. How Big Can They Grow? The Freshwater Tiger Moray Eel is a relatively large species, with adults reaching an average length of 1.5 meters (5 feet). However, some individuals have been known to grow even larger, measuring up to 2 meters (6.5 feet) in length. These eels have a slender body shape, allowing them to navigate through narrow crevices and holes in their freshwater habitats. What Do They Eat? As carnivorous predators, Freshwater Tiger Moray Eels have a diverse diet. They primarily feed on small fish, crustaceans, and mollusks. Using their strong jaws and sharp teeth, they are able to capture and swallow their prey whole. These eels are known for their voracious appetite, consuming a significant amount of food in a single feeding session. How Do They Reproduce? Reproduction in Freshwater Tiger Moray Eels is an intriguing process. They are oviparous, which means that they lay eggs. The female eel releases her eggs into the water, where they are fertilized by the male. The eggs then develop and hatch into larvae, which eventually transform into juvenile eels. It is worth noting that the reproductive behavior of these eels is still not fully understood, and further research is needed to uncover all the details. Are They Dangerous to Humans? While Freshwater Tiger Moray Eels possess sharp teeth and a powerful bite, they are generally not considered a threat to humans. These eels are shy and elusive, preferring to hide in crevices and only venturing out to hunt for food. However, if provoked or cornered, they may defend themselves by biting. It is important to exercise caution and respect their natural habitat when encountering these magnificent creatures. The Freshwater Tiger Moray Eel is a truly remarkable species that showcases the diversity of life in our planet's freshwater ecosystems. With its striking appearance and unique behaviors, it continues to captivate the interest of researchers and nature enthusiasts alike. By understanding and appreciating these fascinating creatures, we can contribute to the conservation and preservation of their fragile habitats.
How does flow cytometry work immunology? Flow cytometry works by illuminating cells, or other types of particle, as they flow in front of a light source, such as a single or dual laser beam. The light source then detects and correlates signals from those cells. Why is flow cytometry important in immunology? Immunology and Flow Cytometry Efficacy – Because immunological responses are highly dependent on individual reactions, flow cytometry helps to isolate cells for further testing. Speed – Being able to sort thousands of cells per second helps to ensure that the flow cytometry testing is done quickly and efficiently. What is flow cytometry Pubmed? Flow cytometry is a sophisticated instrument measuring multiple physical characteristics of a single cell such as size and granularity simultaneously as the cell flows in suspension through a measuring device. What is the principle of flow? Flow is how work progresses through a system. When a system is working well, or having “good” flow, it tends to move steadily and predictably, whereas, “bad” flow means the work starts and stops. Every time there is a breakdown in the flow, chances of accumulating waste increase. What is polychromatic flow cytometry? The term polychromatic flow cytometry applies to such systems that detect five or more markers simultaneously. Polychromatic flow cytometry is particularly useful in the evaluation of plasma cells, and the role of flow cytometry in the assessment of plasma cell disorders is reviewed in depth. Where is flow cytometry performed? Flow cytometry immunophenotyping may be performed on blood, bone marrow, or other samples to provide this additional information. It can detect normal cells as well as abnormal cells whose pattern of markers are typically seen with specific types of leukemia and lymphoma. Why is flow cytometry done? Flow cytometry is a laboratory method used to detect, identify, and count specific cells. This method can also identify particular components within cells. This method may be used to evaluate cells from blood, bone marrow, body fluids such as cerebrospinal fluid (CSF), or tumors. What is flow cytometry Slideshare? • Flow cytometry is a technique used to detect and measure physical and chemical characteristics of a population of cells or particles • A sample containing cells or particles is suspended in a fluid and injected into the flow cytometer instrument. How is a flow cytometry test done? Flow cytometry is a lab test used to analyze characteristics of cells or particles. During the process, a sample of cells or particles is suspended in fluid and injected into a flow cytometer machine. Approximately 10,000 cells can be analyzed and processed by a computer in less than one minute.
Cracking the AP Biology Exam AN OVERVIEW OF MEIOSIS To preserve the diploid number of chromosomes in an organism, each parent must contribute only half of its chromosomes. This is the point of meiosis. Meiosis is the production of gametes. Since sexually reproducing organisms need only haploid cells for reproduction, meiosis is limited to sex cells in special sex organs called gonads. In males, the gonads are the testes, while in females they are the ovaries. The special cells in these organs—also known as germ cells—produce haploid cells (n), which then combine to restore the diploid (2n) number during fertilization: female gamete (n) + male gamete (n) = zygote (2n) When it comes to genetic variation, meiosis is a big plus. Variation, in fact, is the driving force of evolution. The more variation there is in a population, the more likely it is that some members of the population will survive extreme changes in the environment. Meiosis is far more likely to produce these sorts of variations than is mitosis, and therefore confers selective advantage on sexually reproducing organisms. We’ll come back to this theme in Chapter 12.
Kids’ physical activity before the age of five matters so much because of the developing brain In the current pandemic many parents of young children are finding themselves spending more time in the role of caregiver than usual. Keeping young children physically active and miminizing screen time while parents manage work schedules may be a serious challenge. But even before families became more confined to home due to closures and social distancing, children were not getting enough physical activity. The 2020 ParticipACTION report card report card gives children and youth’s physical activity in Canada a D+. The report says less than one in five children and youth in Canada meet guidelines for sedentary behaviours, physical activity and sleep. The International Physical Literacy Association defines physical literacy as “the motivation, confidence, physical competence, knowledge and understanding to value and take responsibility for engagement in physical activities for life.” Both when children are at home and when they are in care, parents are encouraged to consider how adults are supporting children’s physical development. The importance of early childhood physical literacy development should not be overlooked. The brain connections and neural pathways that are formed before the age of five set the foundations for how the brain will develop throughout life. This not only applies to the social, emotional and cognitive areas of development (or “domains”) but also the physical. There is strong support for physical activity in the early years, and researchers have reported that time spent in this critical developmental period focusing on physical development through physical activity and active play has many benefits. Physically, this includes improved co-ordination and higher levels of fitness. Socially, this means improved co-operation and sharing with others. Emotionally, this means better management of emotions and overall behaviour. Young children who are regularly engaged in physical activities also demonstrate cognitive benefits, including improved attention, problem-solving and persistence in tasks. Research has shown that providing physical activity and active play in the early years positively relates with motor skill ability, fitness levels and physical activity in adolescence and beyond. All these have positive relationships to overall health and wellness. Unprecedented screen time Young children in Canada are growing up with unprecedented access to digital media and technology, which has led to some concerns among health professionals. From a young age, children are enticed with bright and colourful screens and sometimes are just as likely to play games on a phone as they are to play with a ball on the floor, test their balance or ride a tricycle. Consequently, in comparison to previous generations, more children today are entering school lacking basic physical skills. In the province of Manitoba, more than a quarter (26.7 per cent) of children in kindergarten in 2018-19 did not meet motor skill expectations for their age. It’s now more important than ever before that those caring for young children consider opportunities for physical development. Adults play critical role Each person’s physical literacy journey will take its own path, but adults play a crucial role in this journey by providing a range of opportunities and modelling an active lifestyle. Being active as a family is the primary way children will build positive habits for physical activity, particularly before time spent with peers becomes an important factor. Our previous research measured physical activity levels in children and found, on average, kids walked 3,604 fewer steps on a typical weekend day compared to school days. Because parents have a role in children’s physical activity and children typically spend weekends with parents, finding ways to increase family weekend physical activity is important. Early childhood education Some children may also not find adequate physical activity in child care. One study of a sample of about 400 early learning and child care practitioners found that they saw their key responsibilities as promoting social, emotional, and cognitive development — especially numeracy and literacy. This could suggest that children’s physical development and learning may not always take equal priority for practitioners, although regulatory issues and environments can also influence what happens in early learning and care programs. Providing early childhood caregivers with physical literacy knowledge is one way to influence more physical literacy development opportunities for children. One strategy to begin addressing this issue is through education resources such as the Physical Literacy Handbook for Early Childhood Educators. Programs for early childhood caregivers and parents can also help underscore how physical learning, development and engagement is related to other key developmental outcomes. Movement for Life program We partnered with the City of Winnipeg Community Services department to create the Movement for Life! program focused on physical literacy development in the early years. The program, aimed at early childhood caregivers including parents, combines a three-hour educational workshop, a participant handbook and practical sessions facilitated by Fit Kids Healthy Kids. During these sessions, children participate in activities related to physical literacy, while caregivers observe and learn strategies to facilitate these. The goal of the program is that participants will gain confidence, understanding and competence in providing opportunities in physical literacy for very young children. Our research, to date, on the Movement for Life! program shows that early childhood caregivers who participate in the program are more confident in their ability to offer physical activities that develop children’s motivation, confidence, competence, knowledge and understanding related to engagement in physical activities. Don’t need to be Olympians Parents don’t need to be Olympians to get kids active. Simple games and making the most of opportunities to be active are perfect ways to get young kids and families moving together. The early years are critical for establishing a strong foundation for human growth in all developmental domains. Sharing knowledge and strategies, as well as providing enhanced training to those who can most influence physical literacy in young children, is a great place to start. Nathan Hall, Associate Professor, Faculty of Education and Faculty of Kinesiology and Applied Health, University of Winnipeg and Melanie Gregg, Professor of Sport and Exercise Psychology, University of Winnipeg Photos by Shutterstock
File Name: tidal power plant advantages and disadvantages .zip This article evaluates benefits and challenges of various energy sources, including solar, nuclear, wind, and more. Some energy sources are cleaner than others. However, all of them have an impact on the environment. You will be surprised to see that, during the manufacturing of parts, some green technologies may pollute and increase the greenhouse effect more than traditional energy sources. Technologies that are clean as they operate but have a great impact on the environment when they are manufactured especially regarding emission of potent greenhouse gases need more research before being widely adopted. Most of the Earth's energy comes from the Sun. Solar power, that's obvious, but the energy in coal originally came from the Sun too. Prehistoric plants stored the Sun's energy in their leaves, and when they died and eventually formed coal seams, that energy was still there. So when we burn coal or any fossil fuel , we're releasing chemical energy that was stored in plants millions of years ago. The same goes for Wind and Wave power. Waves occur because of winds, and winds blow because the Sun warms our atmosphere. Updated December 6, Tidal turbines, like this one in Nova Scotia, can be used to produce large amounts of clean renewable energy. Image source: Hakai Magazine. With climate change becoming more and more of a threat, there has been an increased focus on renewable energy sources and the demand for clean energy. This has brought on rapid development of new ways to harness energy, like tidal power. Tidal energy pros and cons. Here are the main tidal energy pros and cons:. Local governments can dramatically reduce their carbon footprint by purchasing or directly generating electricity from clean, renewable sources. Using a combination of renewable energy options can help meet local government goals especially in some regions where availability and quality of renewable resources vary. Generating renewable energy on-site using a system or device at the location where the power is used e. Purchasing green power through through renewable energy certificates RECs - also known as green tags, green energy certificates, or tradable renewable certificates — that represent the technology and environmental attributes of electricity generated from renewable resources. Purchasing renewable energy from an electric utility through a green pricing or green marketing program, where buyers pay a small premium in exchange for electricity generated locally from green power resources. On-site power generation provides local governments with the most direct access to renewable energy. In addition to the overall benefits, on-site projects also provide a hedge against financial risks and improve power quality and supply reliability. Tidal power is growing rapidly in interest as countries look for ways to generate electricity without relying on fossil fuels. Tidal power schemes do have several disadvantages as listed below. One of the largest disadvantage to tidal power is its large upfront cost. The few installations that have been tried have demonstrated that the long term cost of electricity generation is lower with tidal power systems, but the large upfront costs can make any such venture risky for private investors. Thus, while there are some private companies working in the industry, most of the cost of building large tidal power systems is falling to governments and taxpayers. The costs of tidal systems stem from two primary areas. It is becoming clearer and clearer by the day that the world must break its addiction to fossil fuels. It is clear that humanity must switch to sustainable energy sources to ensure the survival of both ourselves and of our precious environment upon which we all depend. However, as with all energy sources, there are advantages and disadvantages to using this type of energy. This type of energy does not generate greenhouse gases or cause pollution through oil spills or burning like fossil fuels do. Lets now discuss the advantages and disadvantages of tidal energy. 1) It is an inexhaustible source of energy. 2) Tidal energy is environment friendly energy and.Reply Internal audit manual for microfinance institutions pdf target times pdf free downloadReply Tidal power has great potential for future power and electricity generation because of the massive size of the oceans. Tidal energy is a form of hydropower that.Reply A considerable body of research is currently being performed to quantify available tidal energy resources and to develop efficient devices with which to harness them.Reply Internal audit manual for microfinance institutions pdf strategic role of human resource management pdfReply
In this class we designed and tested mirco robots made from MEMS fabrication, which is similar to computerchip fabrication. The robot contains polymer and metal. The motion of the robot is generated from the capacitive surface that the robot is on. Changes in electric field will allow the robot to deflect to produce motion. The design you see in this video contains two hanging masses on feet. The masses resonate at different frequencies allowing the robot to turn when specific electric frequencies are applied.
An X-ray is a widely used diagnostic test to examine the inside of the body. X-rays are a very effective way of detecting problems with bones, such as fractures. They can also often identify problems with soft tissue, such as pneumonia or breast cancer. If you have a X-ray, you will be asked to lie on a table or stand against a surface so that the part of your body being X-rayed is between the X-ray tube and the photographic plate. An X-ray is usually carried out by a radiographer, a healthcare professional who specialises in using imaging technology, such as X-rays and ultrasound scanners. You can find out more about x-ray tests, how they are performed, their function and the risks by visiting the NHS Choices website.
Many physiological and hormonal shifts occur in teenage bodies as they enter puberty. Darkening of the skin is a prominent feature of puberty. The effects of this phenomenon on adolescents’ sense of self-worth and general health can be devastating. Insight into the causes and potential treatments for skin darkening throughout puberty can be gained by an examination of the scientific literature on the topic. In fact, up to 90% of teenagers have some degree of skin darkening throughout puberty, as stated by the American Academy of Dermatology. While this is a perfectly normal occurrence, some teens may struggle to accept the changes in their looks, especially if they are oblivious to the scientific principles underpinning skin darkening. This article will discuss the physiological mechanisms that cause the skin to darken during adolescence. The physiological and mental effects of this transition will be discussed, as will the function of hormones, genetics, and sun exposure. Helping adolescents feel more confident and capable is possible by increasing our knowledge of the process of skin darkening during puberty. What is Skin Darkening? Hyperpigmentation, or skin darkening, occurs when melanin production increases and causes the skin to darken. The pigment melanin is responsible for the natural hues of our skin, hair, and eyes. Melanin is made by melanocytes, which are found in the epidermis, the skin’s outermost layer. Explanation of Melanin Production The generation of melanin is controlled by a number of variables, including genetics, hormones, and UV exposure. The melanocytes’ production of melanin is a natural defense mechanism of the body that is triggered when the skin is exposed to UV radiation from the sun. How Melanin Production Contributes to Skin Darkening The pigment melanin plays a role in skin darkening by contributing to the skin’s deepening hue. Melanin absorbs ultraviolet (UV) light and turns it into heat, which helps prevent cellular damage from the sun. Hyperpigmentation occurs when the skin’s melanocytes are damaged as a result of prolonged exposure to UV rays, making the skin’s melanin distribution more patchy. Types of Melanin Eumelanin and pheomelanin are both forms of melanin. The pigment eumelanin gives skin its brown and black tones, whereas the pigment pheomelanin gives it its red and yellow hues. Darker-skinned persons have more eumelanin and lighter-skinned people have more pheomelanin in their skin. What Causes Skin Darkening During Puberty? Many teenagers develop hyperpigmentation (a darkening of the skin) or a change in skin tone (a lightening of the skin) during puberty. Skin darkening throughout puberty can be attributed to several reasons, including fluctuating hormone levels, time spent in the sun, and racial/ethnic background. Changes in Hormone Levels Hormonal shifts occur during puberty and may alter melanin synthesis, the pigment responsible for skin color. Androgens like testosterone (among others) have been shown to increase melanin formation, which in turn darkens the skin. Therefore, adolescents with elevated testosterone levels may have hyperpigmentation during the onset of puberty. During puberty, when many adolescents spend more time outdoors, sun exposure is a common cause of skin darkening. The sun’s ultraviolet rays can cause your skin to produce more melanin, which can cause your skin to darken. Therefore, it is crucial to use sunscreen with an SPF of 30 or higher and wear protective clothing, hats, and sunglasses. Ethnicity and Genetics Both hereditary and environmental variables have a role in establishing an individual’s skin tone. There is more melanin in the skin of persons with darker skin tones and less in the skin of those with lighter skin tones. People of African-American, Hispanic, and South Asian descent are disproportionately affected by this phenomenon throughout adolescence. Hyperpigmentation during adolescence can also be caused by genetic diseases such as familial hyperpigmentation or melasma. How Hormones Affect Skin Pigmentation Skin pigmentation is just one of many biological processes that are controlled by hormones. Estrogen and testosterone are the main hormones that influence skin color. The Role of Hormones Melanin, the pigment responsible for skin color, is produced and controlled in large part by hormones. Ovaries and testes generate the sex hormones estrogen and testosterone, respectively. Changes in skin pigmentation can occur because of the effects of these hormones on melanocytes, the cells responsible for making melanin. Effects of Estrogen on Skin Pigmentation Estrogen has been shown to increase melanin synthesis, which can make skin darker. Hyperpigmentation is a common side effect of pregnancy in women because estrogen levels rise. Melasma or chloasma is a skin disorder characterized by the development of brown spots on the cheeks, nose, and upper lip. Changes in skin pigmentation, including hyperpigmentation, have been linked to estrogen therapy. Effects of Testosterone on Skin Pigmentation Testosterone’s effects on skin pigmentation can be somewhat different from estrogen’s, yet it can still have an influence. Sebum, or oil secreted by the skin’s sebaceous glands, can be stimulated to create more oil by testosterone. This can cause acne and other skin problems, including changes in skin tone. In addition, increased melanin production due to elevated testosterone levels might cause hyperpigmentation (darkening of the skin). The Impact of Sun Exposure on Skin Darkening Sunlight has a significant role in the development of hyperpigmentation, or the darkening of the skin. Sunburns, early signs of aging, and even skin cancer have all been linked to the sun’s harmful ultraviolet (UV) radiation. Below, I will go through the dangers of tanning beds, the effects of direct sunlight, and preventative measures you may take to keep your skin healthy. How UV Rays a\Affect the Skin Sunlight’s ultraviolet (UV) radiation can create mutations in skin cells’ DNA, which can eventually lead to cancer. Melanin, the pigment responsible for skin color, can be produced in response to exposure to UV rays. Hyperpigmentation, or a darkening of the skin, can result from an increase in melanin production and, if untreated, can be permanent. Premature aging, including wrinkles, age spots, and drooping skin, can develop with prolonged sun exposure. The Impact of Tanning Beds Tanning beds produce dark skin by exposing users to artificial UV rays. However, tanning beds release more dangerous quantities of UV radiation, making them even more dangerous than sunbathing. The use of tanning beds has been associated with an increased risk of skin cancer, particularly the most deadly form of the disease, melanoma. This is why safer alternatives to tanning beds, such as self-tanners and spray tans, are preferable. How to Protect the Skin From Sun Damage Hyperpigmentation and skin darkening can be prevented by taking precautions against sun exposure. Among these are: - Protect yourself from the elements by donning a hat, sunglasses, and long sleeves whenever you venture outside. - Applying a broad-spectrum sunscreen with at least an SPF of 30 before going outside, and reapplying it every two hours (more often if swimming or sweating). - Seeking out shady areas between the hours of 10 a.m. and 4 p.m. - Keeping away from UV generators like tanning beds. - Antibiotics and some acne treatments, among others, might enhance UV sensitivity, so it’s important to be aware of this. - Keeping an eye out for any moles or lesions that show signs of change and consulting a doctor. The Role of Genetics in Skin Darkening Both hereditary and environmental variables interact to establish an individual’s skin tone. Genetic factors are crucial in skin darkening because they control how much and what kind of melanin the skin’s pigment cells (melanocytes) generate. In this reply, we’ll talk about the hereditary elements that cause dark skin, how race affects skin tone, and what additional hereditary variables contribute to pigmentation. Explanation of Genetic Factors Genes that affect melanin production, melanin subtypes, and melanin distribution in the skin are just a few of the many genes that influence skin color. The amount and kind of melanin generated, for instance, can be affected by variations in the MC1R gene, which codes for a protein involved in melanin formation. Different forms of this gene are associated with a wide spectrum of skin tones. The Impact of Ethnicity on Skin Color The production of melanin varies greatly amongst ethnic groups, making ethnicity a crucial factor in determining skin tone. There is more melanin in the skin of people with darker skin tones and less in the skin of those with lighter skin tones. People of African heritage, for instance, have a darker complexion than those of European descent because their skin contains more of the pigment melanin. However, due to genetic and environmental influences, there can be a wide range of skin tones even among members of the same ethnic group. Other Genetic Factors That Contribute to Skin Darkening There are other genes besides MC1R that can have a role in skin pigmentation. The production of eumelanin, the melanin responsible for dark skin, can be affected by mutations in the ASIP gene, for instance. Because it is involved in melanin transport to skin cells, SLC24A5 gene variants can also influence skin pigmentation. Variations in the HERC2 gene, as well as the TYR and OCA2 genes, have been linked to differences in skin pigmentation. The Psychological Impact of Skin Darkening During Puberty Because of the hormonal shifts that occur throughout puberty, skin darkening often occurs. Although this is a normal part of growing up, it can have a profound emotional impact on teenagers, especially those who struggle with low self-esteem or who have to deal with criticism from others. Here, we’ll talk about the mental effects of puberty’s inevitable darkening of the skin, including how it affects a child’s sense of self-worth, how different cultures see different shades of skin, and why it’s crucial to keep lines of communication open with adolescents going through this transition. Relationship Between Appearance and Self-Esteem Self-perception and social perception are both heavily influenced by outward appearance. Skin darkening during puberty can contribute to the already overwhelming sense of physical and emotional change that many adolescents experience. Negative actions, such as withdrawing from social situations or taking risks, are often the result of low self-esteem. It’s worth noting that some people who experience skin darkening may come to appreciate their new skin color, while others may have difficulty accepting it. Cultural Attitudes Toward Skin Color Teenagers’ self-perceptions of their skin color may be influenced by cultural attitudes toward skin color. Lighter skin is prized in some societies, while darker complexions are sometimes stigmatized. Teenagers, especially those who are of a different ethnicity or cultural background than their peers, may experience feelings of shame or self-consciousness as a result of these attitudes. However, there are communities where a lighter complexion is seen as a sign of weakness, whereas darker skin is viewed as a symbol of strength and life. Open Dialogue is Crucial During Puberty for Children When a child is going through puberty, it’s important for them to talk openly with their parents about how they feel about their child’s skin darkening and other changes in their appearance. Parents can aid their children by showing unconditional love and acceptance, talking about the importance of accepting others regardless of their appearance and addressing any hurtful words or situations their children may have experienced. Parents should listen to their children and encourage them to talk about how they feel in a secure and accepting setting. Coping with Skin Darkening During Puberty Many adolescents have a difficult time adjusting to the changes in their looks and health brought on by their skin’s darkening as they enter adulthood. This response will address the issue of skin darkening during puberty and offer solutions for dealing with it, such as promoting body positivity, caring for the skin, and guidance for parents and caregivers. Tips for Maintaining Healthy Skin Teenagers going through puberty, more than anyone else, need to take extra care of their skin. Here are some suggestions for keeping your skin in good condition: - Use sunscreen: Protect your skin from sun damage and skin discoloration by using sunscreen with an SPF of at least 30. - Stay hydrated: The skin may be kept moisturized and looking healthy by drinking plenty of water. - Follow a healthy diet: You can acquire the vitamins and nutrients your skin needs by eating a diet high in fruits, vegetables, and whole grains. - Avoid tanning beds: There is evidence that tanning beds raise the risk of skin cancer and other skin-related diseases. - Establish a skincare routine: Maintaining healthy skin and warding off breakouts can be accomplished with the use of mild cleansers, moisturizers, and exfoliants. Advice for Parents and Caregivers When a teen’s skin darkens during puberty, parents and other caregivers can play a vital role in easing their transition. Advice for guardians and caregivers is as follows: - Provide positive reinforcement: Teenagers should be encouraged to feel comfortable in their own skin and praised for practicing healthy behaviors like using sunscreen and eating right. - Address negative comments or experiences: Adolescents who are subjected to racism should be talked to about their experiences and given guidance if they need it. - Foster open communication: Teens should feel comfortable talking about their experiences with racism and other biases, therefore facilitating an atmosphere where they may do so openly. Promoting Body Positivity Teens can gain self-esteem and acceptance by learning to love and accept their bodies as they are. Some suggestions for spreading body acceptance: - Encourage positive self-talk: Teens can benefit from learning to talk positively to themselves and concentrating on their positive qualities rather than dwelling on their weaknesses. - Celebrate diversity: Teens should be taught to value and appreciate people of all shapes, sizes, and colors. - Educate on media literacy: Promote media literacy skills and raise awareness of the media’s impact on adolescent self-esteem to aid in the development of a positive body image. Frequently Ask Questions - Skin Darkening: - American Academy of Dermatology: https://www.aad.org/public/diseases/color-problems/skin-darkening - National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3543296/ - World Health Organization: https://www.who.int/news-room/q-a-detail/sun-protection - Hormones and Skin Pigmentation: - DermNet NZ: https://dermnetnz.org/topics/melanocyte-stimulating-hormone/ - Journal of Clinical and Aesthetic Dermatology: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2825123/ - Skin Pharmacology and Physiology: https://www.karger.com/Article/Abstract/496415 - Sun Exposure and Skin Darkening: - Centers for Disease Control and Prevention: https://www.cdc.gov/cancer/skin/basic_info/sun-safety.htm - American Cancer Society: https://www.cancer.org/cancer/skin-cancer/prevention-and-early-detection/uv-protection.html - The Skin Cancer Foundation: https://www.skincancer.org/risk-factors/sunburn/ - Genetics and Skin Darkening: - Journal of Investigative Dermatology: https://www.sciencedirect.com/science/article/abs/pii/S0022202X1547215X - Harvard Health Publishing: https://www.health.harvard.edu/a_to_z/skin-color-and-genetics-a-to-z - National Human Genome Research Institute: https://www.genome.gov/genetics-glossary/Melanin - Psychological Impact of Skin Darkening: - Child Mind Institute: https://childmind.org/article/puberty-mental-health/ - American Psychological Association: https://www.apa.org/monitor/2016/09/physical-appearance - HealthyChildren.org: https://www.healthychildren.org/English/ages-stages/gradeschool/puberty/Pages/Puberty-A-Parents-Guide-for-Boys-and-Girls.aspx
YBP to the end of the Last Glacial Maximum was cooler and with a more balanced supply of moisture than today.During the Last Glacial Maximum, the mean annual temperature decreased from 11 °C (52 °F) down to 5 °C (41 °F) degrees, and annual precipitation had decreased from 100 cm (39 in) down to 45 cm (18 in). The skull length could reach up to 310 mm (12 in) or longer, with a broader palate, frontal region, and zygomatic arches compared with the Yukon wolf. Its sagittal crest was higher, with the inion showing a significant backward projection, and with the rear ends of the nasal bones extending relatively far back into the skull.Geographic differences in dire wolves were not detected until 1984, when a study of skeletal remains showed differences in a few cranio-dental features and limb proportions between specimens from California and Mexico (C. dirus are sometimes easy to identify compared to other Canis specimens because the baculum (penis bone) of the dire wolf is very different from that of all other living canids. Single guben Ecological factors such as habitat type, climate, prey specialization, and predatory competition have been shown to greatly influence gray wolf craniodental plasticity, which is an adaptation of the cranium and teeth due to the influences of the environment.YBP, the abundance of conifers decreased, and those of the modern coastal plant communities, including oak woodland, chaparral, and coastal sage scrub, increased.The Santa Monica Plain lies north of the city of Santa Monica and extends along the southern base of the Santa Monica Mountains, and 28,000–26,000YBP it was dominated by coastal sage scrub, with cypress and pines at higher elevations. Seriøs dating side Allerød The sites range in elevation from sea level to 2,255 m (7,400 ft).Dire wolf fossils have rarely been found north of 42°N latitude, with five unconfirmed reports above this latitude.The dire wolf lived in the Americas during the Late Pleistocene epoch (125,000–10,000 years ago). The species was named in 1858, four years after the first specimen had been found.Two subspecies are recognized, these being Canis dirus guildayi and Canis dirus dirus. The species probably descended from Armbruster's wolf (Canis armbrusteri) and evolved from it in North America. The fossilized jawbone with cheek-teeth was obtained by the geologist Joseph Granville Norwood from an Evansville collector, Francis A. The paleontologist Joseph Leidy determined that the specimen represented an extinct species of wolf and reported it under the name of Canis primaevus. Norwood's letters to Leidy are preserved along with the type specimen (the first of a species that has a written description) at the Academy of Natural Sciences, Philadelphia. The largest collection of dire wolf fossils has been obtained from the Rancho La Brea Tar Pits in Los Angeles, California. Dire wolf remains have been found across a broad range of habitats including the plains, grasslands, and some forested mountain areas of North America, and in the arid savannah of South America.
Crimes Against Humanity A crime against humanity is a serious criminal act committed within the context of a “widespread and systematic attack directed against a civilian population”. A crime against humanity can can occur during war or peace, and can include murder, rape, slavery, persecution, extermination, and torture. War crimes are serious criminal acts committed within the context of an “armed conflict”: a resort to armed force between states. They can also be committed in a civil war. The criminal act must be related to the armed conflict, so a murder or a theft during a war but unrelated to the war is not a “war crime”. A war crime can be many different things, from illegal seizure of property to attacking civilian objects to using prohibited gases. Genocide is an act committed with the intent to destroy in whole or in part a national, ethnic, racial, or religious group. It can include killing or causing serious bodily or mental harm to members of the group. It can also include deliberately inflicting on the group conditions of life calculated to bring about its physical destruction, or imposing measures to prevent births. Genocide can happen during war or peace.
South Dakota Department of Health Office of Disease Prevention - 605-773-3737 — (1-800-592-1861 in South Dakota only) This material is provided for informational purposes only and is not a substitute for medical care. We are not able to answer personal medical questions. Please see your health care provider concerning appropriate care, treatment or other medical advice. What is plague? Plague is a severe disease caused by the bacteria Yersinia pestis that is normally found in rodents and transmitted to man by fleas. Plague can exist in different forms, bubonic and pneumonic plague. Pneumonic plague requires strict isolation and disinfection, and treatment procedures. The disease is relatively rare in the United States, limited to western part of the country. Who gets plague? People working with or visiting areas with infected rodents are at greater risk for contracting plague. Pets may get plague from infected rodents and then transmit the disease to humans. How is plague spread? Plague is most commonly spread by exposure to infected fleas. Other important sources include the handling of tissues from infected animals (especially rabbits or rodents), airborne droplets from humans or household pets with plague pneumonia or by laboratory exposure. Plague has the potential to be used as a bioterrorism agent. It could be mass produced, aerosolized, and disseminated. This has the potential to infect many people with a pneumonic form of plague with the possibility of person to person transmission. What are the symptoms of plague? The initial symptom of bubonic plague would be a swollen, inflamed and tender lymph gland in the body near the site where the infected flea bit the person. Fever is usually present as well as malaise, myalgia, nausea, prostration, headache, and chills. The disease may progress to a generalized blood infection called septicemic plague. Septicemic plague can spread the bacteria throughout the body and create further complications, leading to pneumonic plague, the bleeding into the skin and other organs, septic shock, and/or death. Pneumonic plague symptoms include weakness, a rapidly developing pneumonia with shortness of breath, chest pain, cough, and bloody or watery sputum. Nausea, vomiting, and abdominal pain are also common. Without early and rapid treatment, the symptoms progress to respiratory failure, shock, and can eventually lead to death. Plague is 50% fatal in untreated bubonic plague, whereas untreated pneumonic and septicemic plague are nearly always fatal. How soon do symptoms occur? The incubation period for bubonic plague is generally one to seven days. Pneumonic plague's incubation period is between one to four days. Does past infection with plague make a person immune? Immunity after plague recovery is variable, and may not provide complete protection. Currently there is no licensed vaccine available for plague. What is the treatment for plague? The treatment of plague is a regimen of antibiotics for a minimum of seven days. A variety of antibiotics have been effective against plague. It is extremely important for antibiotics to be given to those exposed as quickly as possible to help prevent the more serious symptoms and death from occurring. What types of animals can harbor plague? Since 2004 plague has been detected in southwestern South Dakota rodents and caused die-offs in local prairie dog colonies. Other animals have also been implicated in the transmission of plague to humans: rock squirrel, wood rat, rabbit, ground squirrel, tree squirrel. What can be done to prevent the spread of plague? The patient, his/her clothing and baggage should be treated to kill all fleas that may be attached. Patients with pneumonic plague should be quarantined until three full days of antibiotic treatment have been administered. Close contacts of the patient should be closely monitored and given antibiotics for seven days. When human or animal cases have been identified, efforts to control the fleas with insecticides, followed by the control of rodents where people live, work and play may be necessary. - Centers for Disease Control and Prevention - Cheyenne River Sioux Tribe
Events Leading Up To World War 2 Events Leading Up To World War 2 World War II killed more people, destroyed more property, disrupted more lives, and probably had more far-reaching consequences than any other war in history. The war, which ended in 1945, eventually involved 61 countries, claimed 50 million lives, and completely changed the geopolitical landscape. The causes of World War II can be easily traced back to many of the unsolved issues from the end of World War I and the treaties that ended it also created new political and economic problems. Forceful leaders in several countries took advantage of these problems to seize power. The desire of dictators in Germany and Italy, and Japan to conquer additional territory brought them into conflict with the democratic nations. After World War I ended, representatives of the victorious nations met in Paris in 1919 to draw up peace treaties for the defeated countries. When the Germans heard about the Treaty of Versailles anger raged throughout the country. They had not been allowed to take part in the talks yet, they were being forced to sign the treaty. The Germans felt they were not to be blamed for the war. Even the soldier sent to sign the Treaty refused to sign it “To say such a thing would be a lie,” and only after the treat of being invaded did they sign. The Treaties were worked out in haste by these countries with opposing goals; and failed to satisfy even the victors. Of all the countries on the winning side, Italy and Japan left the peace conference most dissatisfied. Italy gained less territory than it felt it deserved and vowed to take action on its own. Japan gained control of German territories in the Pacific and thereby launched a program of expansion. But Japan was angered by the peacemakers’ failure to endorse the principle of the equality of all races. The countries that lost World War I–Germany, Austria, Hungary, Bulgaria, and Turkey–were especially dissatisfied with the Peace of Paris. They were stripped of territory, arms and were required to make reparations (payments for war damages). The Treaty of Versailles, which was signed with Germany, punished Germany severely. The German government agreed to sign the treaty only after the victorious powers threatened to invade. Many Germans particularly resented the clause that forced Germany to accept responsibility for causing World War I. World War I seriously damaged the economies of the European countries. Both the winners and the losers came out of the war deeply in debt. The defeated powers had difficulty paying reparations to the victors, and the victors had difficulty repaying their loans to the United States. The shift from a wartime economy to a peacetime economy caused further problems. Italy and Japan suffered from too many people and too few resources after World War I. They eventually tried to solve their problems by territorial expansion. In Germany, runaway inflation destroyed the value of money and wiped out the savings of millions of people. In 1923, the German economy neared collapse. Loans from the United States helped Germany’s government restore order. By the late 1920’s, Europe appeared to be entering a period of economic stability. A worldwide business slump known as The Great Depression began in the United States in 1929. By the early 1930’s, it had halted Europe’s economic recovery. The Great Depression caused mass unemployment, wide spread poverty and despair. It weakened democratic governments and strengthened extreme political movements that promised to end the economic problems. Two movements in particular gained strength. The forces of Communism, known as the Left, called for revolution by the workers. The forces of fascism, called the Right, favored strong national government. Throughout Europe, the forces of the Left clashed with the forces of the Right. The political extremes gained the most support in countries with the greatest economic problems and the deepest resentment of the Peace of Paris. Nationalism was an extreme form of patriotism that swept across Europe during the 1800’s. Supporters of nationalism placed loyalty to the aims of their nation, above any other public loyalty. Many nationalists viewed foreigners and members of minority groups as inferior. Such beliefs helped nations justify their conquest of other lands and the poor treatment of minorities within their borders. Nationalism was a chief cause of World War I, and it grew even stronger after that war. Nationalism went hand in hand with feelings of national discontent. Many Germans felt humiliated by their country’s defeat in World War I and its harsh treatment under the Treaty of Versailles. During the 1930’s, they enthusiastically supported a violently nationalistic organization called The Nazi Party. The Nazi Party declared that Germany had a right to become strong again. Nationalism also gained strength in Italy and Japan. The Peace of Paris established an international organization called The League of Nations to maintain peace. Each country backed its own interests at the expense of other countries this prevented The League from working effectively.. Only weak countries agreed to submit their disagreements to The League of Nations for settlement. Strong nations reserved the right to settle their disputes by threats or, force. The political unrest and poor economic conditions that developed after World War I enabled dictatorships to arise in several countries. Especially in those countries that lacked a tradition of democratic government. During the 1920’s and 1930’s, dictatorships came in to power in the Soviet Union, Italy, Germany, and Japan. They held total power and ruled without regard to law. The dictatorships used terror and secret police to crush opposition to their rule. People who objected risked imprisonment or execution. In the Soviet Union, the Communists, led by Lenin, had seized power in 1917. Lenin had set up a dictatorship that firmly controlled the country by the time he died in 1924. After Lenin’s death, Joseph Stalin and other leading Communists struggled for power. Stalin eliminated his rivals one by one and became the Soviet dictator in 1929. In Italy, economic distress after World War I led to strikes and riots. As a result of the violence, a strongly nationalistic group called The Fascist Party gained many supporters. Benito Mussolini, leader of the Fascists, promised to bring order and prosperity to Italy. He vowed to restore to Italy the glory it had known in the days of the ancient Roman Empire. By 1922, the Fascists had become powerful enough to force the king of Italy to appoint Mussolini premier. Mussolini, who took the title il Duce (the Leader), soon began to establish a dictatorship. In Germany, The Nazi Party made spectacular gains as The Great Depression deepened during the early 1930’s. Many Germans blamed all their country’s economic woes on the hated Treaty of Versailles, which forced Germany to give up territory, resources and pay large reparations. In 1933, Adolf Hitler, the leader of the Nazis, was appointed chancellor of Germany. Hitler, who was called der Fuhrer (the Leader), soon made Germany a dictatorship. He vowed to ignore the Versailles Treaty and to avenge Germany’s defeat in World War I. Hitler preached that Germans were a “superior race” and that such peoples as Jews and Slavs were inferior. He began a campaign of hatred against Jews and Communists. He promised to rid the country of them. Hitler’s extreme nationalism appealed to many Germans. In Japan, military officers began to hold political office during the 1930’s. By 1936, they had strong control of the government. Japan’s military government glorified war and the training of warriors. In 1941, General Hideki Tojo became premier of Japan. During the 1930’s, Japan, Italy, and Germany followed a policy of aggressive. They invaded weak lands; that could be taken over easily. The dictatorships knew what they wanted, and they grabbed it. The democratic countries responded with timidity and indecision to the aggression of the dictatorships. Japan was the first dictatorship to begin a program of conquest. In 1931, Japanese forces seized control of Manchuria, a region of China rich in natural resources. Some historians consider Japan’s conquest of Manchuria as the real start of World War II. Japan made Manchuria a puppet state called Manchukuo. In 1937, Japan launched a major attack against China. It occupied most of eastern China by the end of 1938, though the two countries had not officially declared war. Japan’s military leaders began to speak about bringing all of eastern Asia under Japanese control. Italy looked to Africa to fulfill its ambitions for an empire. In 1935, Italian troops invaded Ethiopia, one of the few independent countries in Africa. The Italians used machine guns, tanks, and airplanes to overpower Ethiopia’s poorly equipped army. They had conquered the country by May 1936. After Hitler took power, he began to build up Germany’s armed forces in violation of the Treaty of Versailles. In 1936, Hitler sent troops into the Rhineland, a region of Germany along the banks of the Rhine River. Under the treaty, the Rhineland was to remain free of troops. In March 1938, German soldiers marched into Austria and united it with Germany. Many people in Germany and Austria welcomed that move. The acts of aggression were easy victories for the dictatorships. The League of Nations proved incapable of stopping them. It lacked an army and the power to enforce international law. The United States had refused to join the League or become involved in European disputes. Great Britain and France were unwilling to risk another war so soon after World War I. The two powers knew they would bear the burden of any fighting. The aggressors soon formed an alliance. In 1936, Germany and Italy agreed to support one another’s foreign policy. The alliance was known as the Rome-Berlin Axis. Japan joined the alliance in 1940, and it became the Rome-Berlin-Tokyo Axis. The Spanish Civil War from 1936 to 1939. In 1936, many of Spain’s army officers revolted against the government. The army rebels chose General Francisco Franco as their leader. Franco’s forces were known as Nationalists or Rebels. The forces that supported Spain’s elected government were called Loyalists or Republicans. The Spanish Civil War drew worldwide attention. Yet during the war, the dictatorships again displayed their might while the democracies remained helpless. Hitler and Mussolini sent troops, weapons, aircraft, and advisers to aid the Nationalists. The Soviet Union was the only power to help the Loyalists. France, Britain, and the United States decided not to become involved. However, Loyalist sympathizers from many countries joined the International Brigades that the Communists formed to fight in Spain. The Spanish Civil War served as a military testing grounds for World War II. Germany, Italy, and the Soviet Union used it to test their weapons and tactics. The war in Spain was also a rehearsal for World War II, in that it split the world into forces that either supported or opposed Nazism and Fascism. Hitler prepared to strike again soon after Germany absorbed Austria in March 1938. German territory then bordered Czechoslovakia on three sides. Czechoslovakia had become an independent nation after World War I. Its population consisted of many nationalities, including more than 3 million people of German descent. Hitler sought control of the Sudetenland, a region of western Czechoslovakia where most of the Germans lived. Urged on by Hitler, the Sudeten Germans began to clamor for union with Germany. Czechoslovakia was determined to defend its territory. France and the Soviet Union had pledged their support. As tension mounted, Britain’s Prime Minister Neville Chamberlain tried to restore calm. Chamberlain wished to preserve peace at all cost. He believed that war could be prevented by meeting Hitler’s demands. That policy became known as appeasement. Chamberlain had several meetings with Hitler during September 1938 as Europe teetered on the edge of war. Hitler raised his demands at each meeting. On September 29, Chamberlain and French Premier Edouard Daladier met with Hitler and Mussolini in Munich, Germany. Chamberlain and Daladier agreed to turn over the Sudetenland to Germany, and they forced Czechoslovakia to accept the agreement. Hitler promised that he had no more territorial demands. The Munich Agreement marked the height of the policy of appeasement. Chamberlain and Daladier hoped that the agreement would satisfy Hitler and prevent war–or that it would at least prolong the peace until Britain and France were ready for war. The two leaders were mistaken on both counts. The failure of appeasement soon became clear. Hitler broke the Munich Agreement in March 1939 and seized the rest of Czechoslovakia. He thereby added Czechoslovakia’s armed forces and industries to Germany’s military might. In the months before World War II began, Germany’s preparations for war moved ahead faster than did the military build-up of Britain and France.
Structural Biochemistry/Proteins/Nitrogen Fixation Nitrogen Fixation, or rather, the fixing of Nitrogen, is a process where N₂ is reduced into NH₃, either biologically or abiotically. The nitrogen in amino acids, pyrimidines, purines and other molecules all come from the N₂ in our atmosphere. The fixing of nitrogen can also be associated with the conversion of nitrogen into other forms, other than ammonia, such as nitrogen dioxide. The triple bond that is present in N₂ is very strong; it has a bond energy of 940 kJ/mol. Yet, it is thermodynamically favorable to form ammonia from hydrogen and nitrogen, yet the reaction is still very difficulty kinetically speaking since intermediates can prove to be unstable. It has been estimated that approximately 60 percent of the newly fixed nitrogen on Earth is produced by diazotrophic microorganisms, while lightning and ultraviolet radiation contribute another 15 percent and the rest 25 percent is done by industrial processes. The main avenue for entry of nitrogen into the biosphere is nitrogen fixation. In the nitrogen fixation, we basically fix the dinitrogen, or nitrogen gas into ammonia. Also, fixation of nitrogen requires lots of energy because the triple bond of nitrogen gas is stable. However, breaking the triple bond to generate ammonia requires a series of reduction steps involving high input of energy. Biologically speaking, the conversion of nitrogen into ammonia is usually done by bacteria and archaea. These organisms that are responsible for nitrogen fixation are called diazotrophic microorganisms. For example, the symbiotic Rhizobium bacteria, a diazotrophic microorganism, goes into the roots of leguminous plants to form root nodules where they fix nitrogen. Other examples include Cyanobacteria, Azotobacteraceae, and Frankia. Industrial Processes of Nitrogen Fixation include Dinitrogen complexes, Ambient Nitrogen reduction, and the most common process is the Haber process, invented in 1910. The Haber process involves high pressure, high temperatures, possibly an iron or ruthenium catalyst to produce ammonia. Nitrogen Fixation, in the biological sense, is run by an enzyme called nitrogenase. The reason why the nitrogenase complex is used is because it has multiple redox centers. In general though, nitrogenase complex contains two proteins. The first, a reductase, which provides electrons while the second part, nitrogenase, uses these electrons to turn nitrogen into ammonia. The transferring of electrons, from reductase to nitrogenase, in this process is coupled with the hydrolysis of ATP by the reductase. The reaction for this process is N2 + 8 H+ → 2 NH3 + H2. The reason why this process is an 8 electron process and not simply a 6 electron process is due to the extra mole of Hydrogen that gets generated along with the generation of the ammonia. Often the microorganisms that carry out nitrogen fixation, contain the 8 electrons from the reduced form of Ferredoxin, which can be made from photosynthesis or oxidative processes. Also, this process is coupled by two ATP molecules for each mole, which in turn, equals 16 molecules. The reason for this is not that the ATP hydrolysis is making the reduction thermodynamically favorable since the process is already thermodynamically favorable, but rather allows the reaction to be kinetically possible. Nitrogen fixing bacteria generally separate anaerobic nitrogen fixation from aerobic metaboism by one of several mechanisms. In the ocean and in the freshwater systems, cyanobacteria are the major nitrogen fixers. Within an ecosystem, nitrogen fixers ultimately make the reduced nitrogen available for assimilation by nonfixing microbes and plants. Besides, nitrogen fixation is extremely energy intensive; thus the rate of fixation usually fails to meet the potential demand of other members of the ecosystem. Berg, Tymoczko, Stryer, Biochemistry Sixth Edition Slonczewski, Joan L. Microbiology. "An Evolving Science." Second Edition.
The Sabine's Gull is a small species of gull that breeds across parts of the Arctic. They are highly migratory; many birds travel down to coastal areas around South America and southern Africa for the winter. In most taxonomies, the Sabine's Gull is considered to be the only bird in its genus, Xema. Its general behavior and especially its hunting-style and flight are all particularly tern-like. Sabine's Gulls are named for the Irish ornithologist and explorer Sir Edward Sabine. Two other birds are named after Sabine: Sabine's Puffback (a kind of bushshrike) and Sabine's Spinetail (a type of swift).
Gestational diabetes is diabetes during pregnancy. It usually goes away once delivery is done, however it does make the development of diabetes mellitus in future more likely for the mother and the child. Like in other types of diabetes in gestational diabetes to blood sugar is raised. High blood glucose is caused because the mother can’t produce enough insulin and resistant to insulin. Insulin resistance occurs due to fat burden and hormones produces by the placenta. Insulin helps move glucose out of the blood and into the body’s cells where it can be turned into energy. A pregnant woman’s cells naturally become slightly more resistant to insulin and its effects. This change is specially designed to increase the mother’s blood glucose level to make more nutrients available to the baby. Obesity before pregnancy adds to insulin resistance. The mother’s body makes more insulin to keep the blood glucose level normal. In a small number of women, even this increase is not enough to keep their blood glucose levels in the normal range. As a result, they develop gestational diabetes. Thus Gestational diabetes is caused by a change in the way a woman’s body responds to insulin during pregnancy. A pregnant woman’s insulin needs are two to three times higher than that of normal. Two reasons why the mother needs more insulin: • Pregnancy causes the release of certain types of hormones (made by the placenta) which make it harder for insulin to do its job • Because the growth demands of the foetus (developing baby) increase the mother’s need for insulin Effects OF GESTATIONAL diabetes on mother and child? The risks to the mother include: • An increased chance of a caesarean section to deliver the baby. • An increased chance of developing pregnancy-induced hypertension and protein in the urine. • An increased chance of getting urinary tract infections. The risks to the baby include: • Being very fat and large at birth. Babies who are too large (4 kgs) or fat at birth have a much higher risk of developing serious problems following their birth. • Having their shoulders dislocated during the birth process (because they are too large to fit well through the birth canal). • Having a serious low blood glucose level soon after birth. This can happen because before being born the baby had been getting a very high level of glucose out of the mother’s blood (across the placenta). The baby had adjusted to this high glucose level by making high levels of its own insulin. When the placenta separates after birth this high level of glucose (from the mother) suddenly stops. The baby still has very high levels of its own insulin and this can cause its blood glucose to fall too low. • Prolonged new-born jaundice • Low levels of calcium in its blood. • Respiratory distress syndrome (this can be quite dangerous). • Underweight and small babies. • Future risk of developing diabetes with increased chances of diabetes-related complications of eye, kidney, brain and feet. This risk reduces with a reduction in the weight and waist length of the mother and the child. Symptoms of gestational diabetes The symptoms of gestational diabetes can be tiredness and excessive urination. The patient may not have any complaints and diabetes may get detected during blood checkup. Risk of developing gestational diabetes: If you have one or more of the following factors you are more likely to develop gestational diabetes: • Having a family history of type 2 diabetes in a close relative (parents or brothers and sisters) • Having gestational diabetes in a previous pregnancy • If a previous baby had a birth defect • If you are very overweight • If you are aged over 30 • If you have had a previous stillbirth or spontaneous miscarriage • If you’ve had a previous large baby (greater than 4 kilos ) or a small baby • If you have a history of pregnancy-induced high blood pressure, urinary tract infections, or polyhydramnios (too much amniotic fluid) Screening for gestational diabetes? All pregnant women must have screened for gestational diabetes. This test usually is done between 24 weeks and 28 weeks of pregnancy. It may be done earlier if you have risk factors. The only way to confirm gestational diabetes is with a glucose tolerance test, which needs to be carried out after eight hours without food. The woman is given a solution of 75 gms glucose to drink, and then blood samples are taken and analyzed after 2 hours post glucose reading if more than 140 mg/dl is a diagnostic of GDM. Treatment of Gestational diabetes Since every pregnancy is precious and demands good care, it is important to visit a Doctor who is a Diabetes specialist to understand the action plan to control the blood sugar levels. The first line of treatment is to follow a healthy lifestyle but eating nutritious food which full fill needs of mother and growing infants and regular physical exercise during the pregnancy. Some women with gestational diabetes require blood sugar-lowering medicines or insulin to manage their blood sugar levels in a healthy range during pregnancy. The target of blood sugars during pregnancy are: HbA1c < 6.5 % Fasting blood sugar: 80-100 mg/dl 1 Hour post meals: 120-140
Ancient Sunken Cities – 3 Puzzling Enigmas Is the truth of human history concealed and buried beneath the oceans? Hundreds of sunken cities adorn the ocean floors of our planet, and dozens of them are believed to be more than 3 millennia old. Although most people are only familiar with the myth of the underwater kingdom of Atlantis, sunken ruins of ancient civilizations are as real as the Egyptian pyramids and can offer us many clues about the history of humanity. Researchers believe that most sunken civilizations were submerged by the end of the last Ice Age about 9,000 to 10,000 years ago, as the massive ice caps covering much of Europe and North America melted. There are also sunken archaeological sites which are believed to have fallen due to seismic activity, such as earthquakes and volcanic eruption. What makes the following three sites interesting is that they all date back to a time when we have been taught to believe that humans only lived as nomads or in small settlements and were incapable of organizing a large-scale, civilized society. Although some skeptics may continue to argue that structures at these sites were made by nature, many historians and archaeologists are starting to question the mainstream view of ancient human history and continue to seek proof that support their alternative theories that these were man-made, pre-historic civilizations. Found off the coast of India near Pakistan in the Gulf of Cambay, the Cambay Ruins are one of the most ancient of the world’s sunken cities. They were discovered in 2001 by India’s National Institute of Ocean Technology, led by chief geologist Badrinaryan Badrinaryan. Artifacts such as pottery, human bones and sections of wall were recovered from the site. Certain pieces have been carbon-dated at nearly 9,500 years old by both the National Geophysical Research Institute in Hyderabad, India, and Geowissenschaftlicte Gemeinschaftsaulguben in Hannover, Germany. If the carbon-dating carried out by these two organizations is accurate, this site predates the oldest known civilization in the region, the Harappan, by more than 5,000 years. The Cambay Ruins sit at 120 feet (36 meters) underwater and measure five by three miles. Marine archaeologists believe that the buildings at the site stand on enormous foundations, which they discovered using a technique known as sub-bottom profiling. “The [oceanographers] found that they were dealing with two large blocks of apparently man-made structures.” “Cities on this scale are not known in the archaeological record until roughly 4,500 years ago when the first big cities begin to appear in Mesopotamia.” “Nothing else on the scale of the underwater cities of Cambay is known. The first cities of the historical period are as far away from these cities as we are today from the pyramids of Egypt.” ~ Graham Hancock, author of Underworld: The Mysterious Origins of Civilization Sunken City of Yonaguni Off the southern coast of Yonaguni, Japan, about 70 feet underwater lies a massive pyramid, often called the “Japanese Atlantis.” The site is dated to be at least 5,000 years old, based on the dates of stalactites found inside underwater caves that sank with the city. The Yonaguni pyramid is believed by some to have been taken by an earthquake about 2,000 years ago. Some scientists think this is a natural structure resulting from tectonic activity, although many argue that the pyramid is man-made, considering many 90-degree angles, man and animal-like carvings, and what appears to be stairways and a massive arch. “The largest structure looks like a complicated, monolithic, stepped pyramid that rises from a depth of 25 meters [82 feet].” “I think it’s very difficult to explain away their origin as being purely natural, because of the vast amount of evidence of man’s influence on the structures.” ~ Masaaki Kimura, a marine geologist at the University of the Ryukyus in Japan Many experts believe that the site consists of remnants of an old city that existed above ground when the sea levels were much lower than they are today. One possible culture that inhabited this site is the Jomon, Japanese inhabitants, who existed from around 12,000 BC to around 300 BC and are believed to be the first culture on Earth to develop pottery. Some believe that the site is what remains of Mu, a fabled Pacific civilization rumored to have vanished beneath the waves. In the deep waters of Cabo de San Antonio off the west coast of Cuba rests one of the most fascinating of the ancient sunken cities. The site was discovered by the Russian/Canadian oceanographer Paulina Zelitsky and the Advanced Digital Communications exploration company when their expedition in the area brought them upon unusual formations of smooth blocks, crests, and geometric shapes. Because the site is underneath 1,900 to 2,500 feet of water (about a half mile, or 600-750 meters), it has been difficult to truly explore the area. There are no real images of the sunken city of Cabo de San Antonio, although data collected using sonar scans and video reveals structures that are not likely to form naturally. “These are extremely peculiar structures, and they have captured our imagination.” “If I had to explain this geologically, I would have a hard time.” ~ Geologist Manuel Iturralde, director of research at Cuba’s Natural History Museum A theory exists that this sunken metropolis is old enough to have existed during the Ice Age, and it is believed that the city sank anywhere from 15,000 to 50,000 years ago. Ancient stories of the Maya and native Yucatecos passed through the generations tell of an island inhabited by their ancestors that vanished beneath the waves. After continued research, Zelitsky has identified that the site measures about 20 square kilometers (a size of a modern city). She has collected many samples that prove the site is man-made and was at one time above sea level. “Samples that we recovered from the ocean bottom have justified our structures that we call megalithic structures. The samples are granite stone, completely polished, with some incrustations of fossils. Fossils of organic creatures that normally live on the surface, not on the ocean bottom.” “The stone we recovered from ocean bottom is very polished granite. All of the peninsula of northwest part of Cuba, all of this peninsula is limestone, very fractured limestone. So, geologically, it (megalithic granite structures) is totally foreign to Cuba. But it’s also not known in Yucatan because Yucatan is also limestone, not granite. Granite is found only in the center of Mexico.” ~ Paulina Zelitsky, Ocean Engineer, Advanced Digital Communications Just how many ruins of ancient civilizations are buried under the vast ocean waters of the Earth? Underwater findings such as these three sites give us a new perspective on the history of the human race, and more questions than answers. About the Author Terence Newton is a staff writer for WakingTimes.com, and an aficionado of interesting things. When he is not meditating, or thriving on this ball of confusion we call earth, he is busy helping out and spreading light. This article is offered under Creative Commons license. It’s okay to republish it anywhere as long as attribution bio is included and all links remain intact. ~~ Help Waking Times to raise the vibration by sharing this article with the buttons below…
Today we will tell you today is national what day. World Press Freedom Day was established by the United Nations General Assembly in December 1993 after the Seminar for the Development of an Independent and Pluralistic African Press. This seminar was held in Windhoek, Namibia in 1991, and led to the adoption of the Windhoek Declaration on the Promotion of Independent and Pluralistic Media. World Press Freedom Day May 03 The Windhoek Declaration called for the establishment, maintenance and promotion of a pluralistic, free and independent press and emphasized the importance of a free press for the development and preservation of democracy within the world. a state, as well as for economic development. World Press Freedom Day is celebrated on 3 May each year, when the Windhoek Declaration was adopted. Although World Press Freedom Day has been celebrated since 1993, it is taking root even further in the history of the United Nations. Indeed, Article 19 of the 1948 Universal Declaration of Human Rights stipulates that: “Everyone has the right to freedom of opinion and expression, which implies the right not to be worried about his opinions and that of seeking, receiving and spreading, without frontier considerations, information and ideas by any means of expression whatsoever. ” Today, around the world, 3 May has become an opportunity to inform the public about violations of the right to freedom of expression and the time to remember that many journalists face death or imprisonment. Transmitting the news to people. According to the United Nations Educational, Scientific and Cultural Organization (UNESCO), which coordinates activities highlighting May 3, World Press Freedom Day, it is: - A day of action, which promotes and allows the establishment of initiatives aimed at defending the freedom of the press. - An evaluation day, in order to paint a picture of the freedom of the press around the world. - A reminder day, which reminds states of the respect they have given to freedom of the press. - A warning day, to alert the public and increase awareness of the cause of press freedom. - A day of reflection, to stimulate debate among media professionals on issues affecting press freedom and professional ethics. - A commemorative day in memory of the journalists who lost their lives while practicing their profession. - A day of support for the media who are victims of measures that hinder freedom of the press or that aim to abolish it. One weapon the press Freedom of the press is considered a cornerstone of human rights and an assurance that other rights will be respected. It promotes transparency and good governance and represents for society the guarantee that true justice will prevail. Freedom of the press is the bridge that connects understanding and knowledge. It is essential to the exchange of ideas between nations and cultures, which is itself a condition for lasting understanding and cooperation.
June 30, 2010 Desert Bats Reveal The Secret Of Their Survival Desert bats reduce water loss by changing the make-up of their skin, allowing them to thrive in some of the world's most inhospitable environments This is surprising as with large naked wings and the energy they expend in flight, bats are expected to have high rates of water loss by evaporation, say the scientists from the Ben-Gurion University in Israel.This may provide significant insight into how bats might respond to a future changing climate. The researchers are presenting their work at the Society for Experimental Biology Annual Conference in Prague on Wednesday June 30th, 2010. The researchers found total water loss in the desert-living Pipistrellus kuhli was just 80% of other non-desert species. Total water loss is made up of the sum of cutaneous (through the skin) and respiratory (exhaling) water losses, explained lead researcher Dr MuÃ±oz-Garcia. Desert bats were found to have reduced cutaneous water loss (CWL), the biggest contributor to total water loss, when compared to non-desert species of bats of the same size. The proposed mechanism of adjusting the lipid (fat) composition of their skin is known in other species of mammals and birds. Dr MuÃ±oz-Garcia and his team were the first to identify this link in other species of bat, and aim to prove it in desert bats. The scientists believe that these findings provide significant insight into how bats can adapt to major changes in their environment. "Control of energy expenditure and water loss is crucial for all terrestrial animals to survive and reproduce", explains lead researcher AgustÃ MuÃ±oz-Garcia. "This is particularly important for animals that live in deserts, where ambient temperatures are high, humidity is low and drinking water is scarce" The next step for Dr MuÃ±oz-Garcia and his team is to examine further species of desert bats to consolidate their findings so far and shed more light on the adaptive mechanism for reducing CWL. "Our plan is to measure at least 8 species from different environments, so we can start building a database that can allow future comparisons", Dr MuÃ±oz-Garcia explained. Image Caption: The researchers found total water loss in the desert-living Pipistrellus kuhli was just 80 percent of other nondesert species. Credit: Shai Pilosof On the Net:
Life cycle – Sporophyte development Hornwort sporophytes lack setae. Each tapering "horn-like" sporophyte, that grows out from a bulbous foot embedded in the thallus is entirely spore capsule. To see the foot you need to dissect the hornwort. The immature sporophyte is green and so, like the immature moss sporophyte, photosynthesizes. A liverwort or moss capsule comes to a definite stop in its development, with the spores having all matured together. The capsule then opens in some way to release the spores. In the hornwort genus Notothylas the sporophyte also has a determinate period of growth. By contrast in the other hornwort genera the sporophyte is continually growing from near the base. In theory such a sporophyte could grow indefinitely, though the death of the aging thallus or changes in environmental conditions eventually put a stop to sporophyte growth. Technically the near-basal area in which there is continual cell addition is an example of a meristem. Meristems are found in all plants for all plant growth is via meristematic tissue of some sort. The apical cell, mentioned in the introductory LIFE CYCLE page is an example of a meristematic cell. The meristematic tissue near the base of a hornwort sporophyte is composed of a number of cells. By the production of new cells the meristem is constantly causing the sporophyte to extend upward. This means that the oldest part of the sporophyte is at the apex with regions progressively younger as you go down the sporophyte. When the sporophyte is still very short it is enclosed within a protective sheath (an involucre) but the sporophyte grows through it, leaving a cylindrical remnant around the sporophyte's base. This photo of a species of Megaceros shows some involucral remnants quite well. Given that the oldest cells in the sporophyte are near the apex it is in the apical region that the first spores mature. Then the spores a little lower mature and so on. In this photo the majority of sporophytes are brown in the upper region and green below. The spores in the brown areas are approaching maturity but in the green areas spore development is at various earlier stages. As the spores mature the sporophyte walls change from green to brown, though mature spores may be green to brown, the colour depends on genus. When spores near the apex are mature the sporophyte develops slits there. Generally there are two slits but in some species there is only one and there are also species in which four slits develop. As the sporophyte dries the slits open and the spores can be released. As lower areas of the sporophyte mature the slits extend downward. This photo shows a number of sporophytes with dried and open upper regions. In many hornworts the slits stop a little before the sporophyte apex so that the sporophyte segments are united at their apices. In a mature sporophyte you will also find pseudo-elaters. These are tiny, filamentous structures that superficially resemble the spiralled elaters that are a feature of the capsules in many liverwort species. However, elaters and pseudo-elaters have different origins and there's more about the differences between elaters and pseudo-elaters in the ELATERS page. The pseudo-elaters are not spiralled in the genera Anthoceros, Folioceros, Phaeoceros, always spiralled in Megaceros and Dendroceros and have rudimentary spiral thickenings in Notothylas. This photo shows a cross section through the lower, still green region of a hornwort sporophyte. The yellow-green cells forming a ring around the centre are the sporogenous cells that will give rise to spores as well as the pseudo-elaters. Between the sporogenous cells and the sporophyte surface are the chlorophyllous, photosynthesizing cells. The photo (right) is of a cross-section of the upper part of a hornwort spore capsule that has started to turn brown. You can see that the outermost cells now have a brownish tinge. Where the previous photo showed sporogenous cells there is now a mass of dark green cells – a mix of mature spores and pseudo-elaters. Here are some spores and pseudo-elaters. Along the hornwort sporophyte's central axis there is a column of sterile tissue called a columella. This is thought to be a conducting system that helps supply nutrients to the developing spores. When you look at a group of open sporophytes it's easy to see the capsule segments but amongst them you'll find the columellas, thinner and wiry in appearance. If you use a handlens to look closely at mature sporophytes such as the ones shown in this earlier photograph you will be able to see columellas amongst the split capsules. The columellas are markedly thinner than the sporophyte segments. On the left is an enlargement of part of that previous photo and the arrow points to a columella.
Interactions between plants and herbivores can have a significant effect on plant growth and development, and ultimately, on a plant's economic value. Research has traditionally focused on aboveground herbivores, despite the considerable role that belowground herbivory by both vertebrates and invertebrates can play within a range of ecosystem processes. Root feeders have been classified as agricultural pests but can also be used as biological control agents against invasive species and can affect community dynamics of plants, soil micro-organisms and populations of aboveground organisms. Bringing together a broad range of viewpoints and approaches, Root Feeders presents a comprehensive review of knowledge on root herbivores and illustrates their importance within ecosystems. Chapters discuss problems of visualizing the organisms in the soil, their role in agriculture, grassland and forest ecosystems, and present specific case studies on the management, control and influence of root feeders. Covering all aspects from food web ecology to the effects of climate change, this will be valuable reading for researchers and professionals in agricultural entomology, plant science, ecology and soil science. 1: Methods for studying root herbivory 2: New experimental techniques for studying root herbivores 3: Root herbivory in agricultural ecosystems 4: Root herbivory in grassland ecosystems 5: Root herbivory in forest ecosystems 6: Grape phylloxera - an overview 7: Using biocontrol against root feeding pests, with particular reference to Sitona root weevils 8: Invasive root feeding insects in natural forest ecosystems of North America 9: Linking above- and belowground herbivory 10: Root feeders in heterogeneous systems: foraging responses and trophic interactions 11: Climate change impacts on root herbivores
\|Area\|\|14,000,000 km² (5,405,430 mi²) (280,000 km² (108,108 mi²) ice-free, 13,720,000 km² (5,297,321 mi²) ice-covered)\| \|Population\|\|~1000 (none permanent)\| \|governed by the Antarctic Treaty Secretariat \|Partial Territorial claims (subject to the Antarctic Treaty System)\|\| Argentina \|Reserved the right to make claims\|\| Russia Antarctica is Earth's southernmost continent, overlying the South Pole. Situated in the southern hemisphere and largely south of the Antarctic Circle, Antarctica is surrounded by the Southern Ocean. At 14.4 million km², it is the fifth-largest continent in area after Asia, Africa, North America, and South America; in turn, Europe and Australia are smaller. Some 98 percent of Antarctica is covered by ice, which averages at least 1.6 km in thickness. On average, Antarctica is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents. Since there is little precipitation, except at the coasts, the interior of the continent is technically the largest desert in the world. There are no permanent human residents and Antarctica has never had an indigenous population. Only cold-adapted plants and animals survive there, including penguins, fur seals, mosses, lichens, and many types of algae. The name Antarctica comes from the Greek antarktikos, meaning "opposite to the Arctic." Although myths and speculation about a Terra Australis ("Southern Land") date back to antiquity, the first confirmed sighting of the continent is commonly accepted to have occurred in 1820 by the Russian expedition of Mikhail Lazarev and Fabian Gottlieb von Bellingshausen. However, the continent remained largely neglected for the rest of the nineteenth century because of its hostile environment, lack of resources, and isolated location. The Antarctic Treaty was signed in 1959 by twelve countries. To date, forty-five countries have signed the treaty. The treaty prohibits military activities and mineral mining, supports scientific research, and protects the continent's ecozone. Ongoing experiments are conducted by more than 4,000 scientists of many nationalities and with different research interests. Belief in the existence of a Terra Australis—a vast continent located in the far south of the globe to "balance" the northern lands of Europe, Asia, and North Africa—had existed since the times of Ptolemy (first century CE), who suggested the idea in order to preserve the symmetry of all known landmasses in the world. Depictions of a large southern landmass were common in maps such as the early sixteenth century Turkish Piri Reis map. Even in the late seventeenth century, after explorers had found that South America and Australia were not part of the fabled "Antarctica," geographers believed that the continent was much larger than its actual size. European maps continued to show this hypothetical land until Captain James Cook's ships, HMS Resolution and Adventure, crossed the Antarctic Circle on January 17, 1773, and once again in 1774. The first confirmed sightings of Antarctica took place in 1920 and is credited to captains and crews of three ships: - Fabian Gottlieb von Bellingshausen (a captain in the Russian Imperial Navy), - Edward Bransfield (a captain in the British Navy), and - Nathaniel Palmer (an American sealer out of Stonington, Connecticut). Von Bellingshausen is reported to have sighted Antarctica on January 27, 1820, three days before Bransfield sighted land, and ten months before Palmer did so in November 1820. On that day the two-ship expedition led by Von Bellingshausen and Mikhail Petrovich Lazarev reached a point within 32 km (20 miles) of the Antarctic mainland and saw ice fields there. The first documented landing on mainland Antarctica was by the American sealer John Davis in Western Antarctica on February 7, 1821, although some historians dispute this claim. In December 1839, as part of the United States Exploring Expedition of 1838–1842 (conducted by the United States Navy), the expedition comprised of 433 men and six ships sailed from Sydney, Australia into the Antarctic Ocean, as it was then known, and reported the discovery "of an Antarctic continent west of the Balleny Islands." That part of Antarctica was later named "Wilkes Land," after the expedition's commander, Lt. Charles Wilkes, a name it maintains to this day. In 1841, explorer James Clark Ross passed through what is now known as the Ross Sea and discovered Ross Island (both of which were named for him). He sailed along a huge wall of ice that was later named the Ross Ice Shelf. Mount Erebus and Mount Terror are named after two ships from his expedition: HMS Erebus and Terror. Mercator Cooper landed in Eastern Antarctica on January 26, 1853. During an expedition led by Ernest Shackleton in 1907, parties led by T. W. Edgeworth David became the first to climb Mount Erebus and to reach the South Magnetic Pole. In addition, Shackleton himself and three other members of his expedition made several firsts in December 1908–February 1909: they were the first humans to traverse the Ross Ice Shelf, the first to traverse the Transantarctic Mountain Range (via the Beardmore Glacier), and the first to set foot on the South Polar Plateau. On December 14, 1911, a party led by Norwegian polar explorer Roald Amundsen from the ship Fram became the first to reach the geographic South Pole, using a route from the Bay of Whales and up the Axel Heiberg Glacier. One month later, the Scott Expedition reached the pole. Richard Evelyn Byrd led several voyages to the Antarctic by plane in the 1930s and 1940s. He is credited with implementing mechanized land transport on the continent and conducting extensive geological and biological research. However, it was not until October 31, 1956, that anyone set foot on the South Pole again; on that day a U.S. Navy group led by Rear Admiral George Dufek successfully landed an aircraft there. Centered asymmetrically around the South Pole and largely south of the Antarctic Circle, Antarctica is the southernmost continent and is surrounded by the southern waters of the World Ocean. Alternatively it is washed by the Southern Ocean or the southern Pacific, Atlantic, and Indian Oceans. It covers more than 14 million km², making it the fifth-largest continent, about 1.3 times larger than Europe. The coastline measures 17,968 km (11,160 miles) and is mostly characterized by ice formations. Antarctica is divided in two by the Transantarctic Mountains close to the neck between the Ross Sea and the Weddell Sea. The portion west of the Weddell Sea and east of the Ross Sea is called Western Antarctica and the remainder Eastern Antarctica, because they roughly correspond to the Western and Eastern Hemispheres relative to the Greenwich meridian. Approximately 98 percent of Antarctica is covered by the Antarctic ice sheet, a sheet of ice averaging at least one mile in thickness. The continent has approximately 90 percent of the world's ice (and thereby approximately 70 percent of the world's fresh water). If all of this ice were melted, sea levels would rise about 200 feet (61 m). In most of the interior of the continent precipitation is very low, down to 20 mm/year; in a few "blue ice" (glacial ice) areas precipitation is lower than mass loss by sublimation causing the local mass balance to be negative. In the dry valleys the same effect occurs over a rock base, leading to a desiccated landscape. Western Antarctica is covered by the West Antarctic Ice Sheet. The sheet has been of recent concern because of the real, if small, possibility of its collapse. If the sheet were to break down, ocean levels would rise by several meters in a relatively geologically short period of time, perhaps a matter of centuries. Several Antarctic ice streams, which account for about 10 percent of the ice sheet, flow to one of the many Antarctic ice shelves. Vinson Massif, the highest peak in Antarctica at 16,050 feet (4,892 meters), is located in the Ellsworth Mountains. Although Antarctica is home to many volcanoes, only Mount Erebus is known to be active. Located on Ross Island, Erebus is the southernmost active volcano. There is another famous volcano called Deception Island, which is famous for its giant eruption in 1970. Minor eruptions are frequent and lava flow has been observed in recent years. Other dormant volcanoes may potentially be active. In 2004, an underwater volcano was found in the Antarctic Peninsula by American and Canadian researchers. Recent evidence shows this unnamed volcano may be active. Antarctica is home to more than 70 lakes that lie thousands of meters under the surface of the continental ice sheet. Lake Vostok, discovered beneath Russia's Vostok Station in 1996, is the largest of these subglacial lakes similar in size to Lake Ontario. It is believed that the lake has been sealed off for 25 million years. There is some evidence, in the form of ice cores drilled to about 400 m above the water line, that Vostok's waters may contain microbial life. The sealed, frozen surface of the lake shares similarities with Jupiter's moon Europa. If life is discovered in Lake Vostok, this would strengthen the argument for the possibility of life on Europa. Flora and fauna The climate of Antarctica does not allow extensive vegetation. A combination of freezing temperatures, poor soil quality, lack of moisture, and lack of sunlight inhibit the flourishing of plants. As a result, plant life is limited to mostly mosses and liverworts. The autotrophic community is made up of mostly protists. The flora of the continent largely consists of lichens, bryophytes, algae, and fungi. Growth generally occurs in the summer, and only for a few weeks at most. There are more than 200 species of lichens and approximately 50 species of bryophytes, such as mosses. Seven hundred species of algae exist, most of which are phytoplankton. Multicolored snow algae and diatoms are especially abundant in the coastal regions during the summer. There are two species of flowering plants found in the Antarctic Peninsula: Deschampsia antarctica (Antarctic hair grass) and Colobanthus quitensis (Antarctic pearlwort). Land fauna is nearly completely invertebrate. Invertebrate life includes microscopic mites, lice, nematodes, tardigrades, rotifers, krill, and springtails. The flightless midge Belgica antarctica, just 12 mm in size, is the largest land animal in Antarctica. The Snow Petrel is one of only three birds that breed exclusively in Antarctica. They have been seen at the South Pole. A variety of marine animals exist and rely, directly or indirectly, on the phytoplankton. Antarctic sea life includes penguins, blue whales, orcas, and fur seals. The Emperor penguin is the only penguin that breeds during the winter in Antarctica, while the Adélie Penguin breeds farther south than any other penguin. The Rockhopper penguin has distinctive feathers around the eyes, giving the appearance of elaborate eyelashes. King penguins, Chinstrap penguins, and Gentoo Penguins also breed in the Antarctic. It is the male partner of both the King and Emperor penguins that is responsible for incubating the single egg for up to two months by balancing it on top of their feet and keeping it warm under a special pouch, while the female feeds out at sea. The Antarctic fur seal was very heavily hunted in the eighteenth and nineteenth centuries for its pelt by sealers from the United States and the United Kingdom. The Weddell Seal, a "true seal," is named after Sir James Weddell, commander of British sealing expeditions in the Weddell Sea. Antarctic krill, which congregates in large schools, is the keystone species of the ecosystem of the Southern Ocean, and is an important food organism for whales, seals, leopard seals, fur seals, squid, icefish, penguins, albatrosses, and many other birds. The 1978 enactment of the Antarctic Conservation Act in the U.S. brought several restrictions to U.S. activity on the continent. The introduction of alien plants or animals can bring a criminal penalty, as can the extraction of any indigenous species. The overfishing of krill, which plays a large role in the Antarctic ecosystem, led officials to enact regulations on fishing. The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR), a treaty that came into force in 1980, requires that regulations managing all Southern Ocean fisheries consider potential effects on the entire Antarctic ecosystem. Despite these new acts, unregulated and illegal fishing, particularly of Patagonian toothfish, remains a serious problem. The illegal fishing of toothfish has been increasing, with estimates of 32,000 tons in the year 2000. Antarctica is the coldest place on Earth. It is a frozen desert with little precipitation; the South Pole itself receives less than 4 inches (10 cm) per year, on average. Temperatures reach a minimum of between -80°C and -90°C (-112°F and -130°F) in the interior in winter and reach a maximum of between 5°C and 15°C (41°F and 59°F) near the coast in summer. Sunburn is often a health issue as the snow surface reflects almost all of the ultraviolet light falling on it. Eastern Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the center cold and dry. Despite the lack of precipitation over the central portion of the continent, ice there lasts for extended time periods. Heavy snowfalls are not uncommon on the coastal portion of the continent, where snowfalls of up to 1.22 meters (48 inches) in 48 hours have been recorded. At the edge of the continent, strong katabatic winds off the polar plateau often blow at storm force. In the interior, however, wind speeds are typically moderate. During summer, more solar radiation reaches the surface during clear days at the South Pole than at the equator because of the 24 hours of sunlight each day at the Pole. Antarctica is colder than the Arctic for two reasons. First, much of the continent is more than 3 km above sea level, and temperature decreases with elevation. Second, the Arctic Ocean covers the north polar zone: The ocean's relative warmth is transferred through the icepack and prevents temperatures in the Arctic regions from reaching the extremes typical of the land surface of Antarctica. Given the latitude, long periods of constant darkness or constant sunlight create climates unfamiliar to human beings in much of the rest of the world. The aurora australis, commonly known as the southern lights, is observed in the night sky near the South Pole. Typically the aurora appears either as a diffused glow or as "curtains" that approximately extend in the east-west direction. Each curtain consists of many parallel rays, each lined up with the local direction of the magnetic field lines, suggesting that aurora is shaped by the earth's magnetic field. Another unique spectacle is diamond dust, a ground-level cloud composed of tiny ice crystals that may continue for several days without interruption. It generally forms under otherwise clear or nearly clear skies, so people sometimes also refer to it as clear-sky precipitation. A sun dog, a frequent atmospheric optical phenomenon, is a bright "spot" beside the true sun that typically appears when the sun is low, such as at sunrise and sunset. Geological history and paleontology More than 170 million years ago, Antarctica was part of the supercontinent Gondwana. Over time, Gondwana gradually broke apart and Antarctica as it is known today was formed around 25 million years ago. Paleozoic era (540-250 Mya) During the Cambrian period, Gondwana had a mild climate. West Antarctica was partially in the northern hemisphere, and during this period large amounts of sandstones, limestones, and shales were deposited. East Antarctica was at the equator, where sea-floor invertebrates and trilobites flourished in the tropical seas. By the start of the Devonian period (416 Mya), Gondwana was in more southern latitudes and the climate was cooler, though fossils of land plants are known from this time. Sand and silts were laid down in what is now the Ellsworth, Horlick, and Pensacola Mountains. Glaciation began at the end of the Devonian period (360 Mya), as Gondwana became centered around the South Pole and the climate cooled, though flora remained. During the Permian period, the plant life became dominated by fern-like plants such as Glossopteris, which grew in swamps. Over time these swamps became deposits of coal in the Transantarctic Mountains. Towards the end of the Permian period, continued warming led to a dry, hot climate over much of Gondwana. Mesozoic era (250-65 Mya) As a result of continued warming, the polar ice caps melted and much of Gondwana became a desert. In East Antarctica, the seed fern became established, and large amounts of sandstone and shale were laid down at this time. The Antarctic Peninsula began to form during the Jurassic period (206-146 Mya), and islands gradually rose out of the ocean. Ginkgo trees and cycads were plentiful during this period, as were reptiles such as Lystrosaurus. In West Antarctica, coniferous forests dominated through the entire Cretaceous period (146-65 Mya), though Southern beech began to take over at the end of this period. Ammonites were common in the seas around Antarctica, and dinosaurs were also present, though only two Antarctic dinosaur species (Cryolophosaurus, from the Hanson Formation, and Antarctopelta) have been described to date. It was during this period that Gondwana began to break up. Gondwana breakup (160-23 Mya) Africa separated from Antarctica around 160 Mya, followed by the Indian subcontinent, in the early Cretaceous (about 125 Mya). About 65 Mya, Antarctica (then connected to Australia) still had a tropical to subtropical climate, complete with a marsupial fauna. About 40 Mya Australia-New Guinea separated from Antarctica and the first ice began to appear. Around 23 Mya, the Drake Passage opened between Antarctica and South America, which resulted in the Antarctic Circumpolar Current. The ice spread, replacing the forests that then covered the continent. Since about 15 Mya, the continent has been mostly covered with ice. Geology of present-day Antarctica The geological study of Antarctica has been greatly hindered by the fact that nearly all of the continent is permanently covered with a thick layer of ice. However, new techniques such as remote sensing, ground-penetrating radar, and satellite imagery have begun to reveal the structures beneath the ice. Geologically, West Antarctica closely resembles the Andes mountain range of South America. The Antarctic Peninsula was formed by uplift and metamorphism of sea-bed sediments during the late Paleozoic and the early Mesozoic eras. This sediment uplift was accompanied by igneous intrusions and volcanism. The most common rocks in West Antarctica are andesite and rhyolite volcanics formed during the Jurassic period. There is also evidence of volcanic activity, even after the ice sheet had formed, in Marie Byrd Land and Alexander Island. The only anomalous area of West Antarctica is the Ellsworth Mountains region, where the stratigraphy is more similar to the eastern part of the continent. East Antarctica is geologically varied, dating from the Precambrian era, with some rocks formed more than 3 billion years ago. It is composed of a metamorphic and igneous platform which is the basis of the continental shield. On top of this base are various modern rocks, such as sandstones, limestones, coal, and shales laid down during the Devonian and Jurassic periods to form the Transantarctic Mountains. In coastal areas such as Shackleton Range and Victoria Land some faulting has occurred. The main mineral resource known on the continent is coal. It was first recorded near the Beardmore Glacier by Frank Wild on the Nimrod Expedition, and now low-grade coal is known across many parts of the Transantarctic Mountains. The Prince Charles Mountains contain significant deposits of iron ore. The most valuable resources of Antarctica lie offshore, namely the oil and natural gas fields found in the Ross Sea in 1973. Exploitation of all mineral resources is banned until 2048 by the Protocol on Environmental Protection to the Antarctic Treaty. Antarctica has no permanent residents, but a number of governments maintain permanent research stations throughout the continent. The number of people conducting and supporting scientific research and other work on the continent and its nearby islands varies from approximately 4,000 in summer to about 1,000 in winter. Many of the stations are staffed year-round. The first semi-permanent inhabitants of regions near Antarctica (areas situated south of the Antarctic Convergence) were British and American sealers who often spent a year or more on South Georgia Island, beginning in 1786. During the whaling era, which lasted until 1966, the population of that island varied from over 1,000 in the summer (over 2,000 in some years) to some 200 in the winter. Most of the whalers were Norwegian, with an increasing proportion of Britons. The settlements included Grytviken, Leith Harbour, King Edward Point, Stomness, Husvik, Prince Olav Harbour, Ocean Harbour, and Godthul. Managers and other senior officers of the whaling stations often lived together with their families. Among them was the founder of Grytviken, Captain Carl Anton Larsen, a prominent Norwegian whaler and explorer who adopted British citizenship in 1910, along with his family. The first child born in the southern polar region was Norwegian girl Solveig Gunbjörg Jacobsen, born in Grytviken on October 8, 1913, with her birth being registered by the resident British Magistrate of South Georgia. She was a daughter of Fridthjof Jacobsen, the assistant manager of the whaling station, and of Klara Olette Jacobsen. Jacobsen arrived on the island in 1904 to become the manager of Grytviken, serving from 1914 to 1921; two of his children were born on the island. Emilio Marcos Palma was the first person born on the Antarctic mainland, at Base Esperanza in 1978; his parents were sent there along with seven other families by the Argentinean government to determine if family life was suitable on the continent. In 1986, Juan Pablo Camacho was born at the Presidente Eduardo Frei Montalva Base, becoming the first Chilean born in Antarctica. Several bases are now home to families with children attending schools at the station. As the only uninhabited continent, Antarctica has no government and belongs to no country. Various countries claim areas of it, although as a rule, no other countries recognize such claims. The area between 90°W and 150°W is the only part of Antarctica, indeed the only solid land on Earth, not claimed by any country. Since 1959, claims on Antarctica have been suspended and the continent is considered politically neutral. Its status is regulated by the 1959 Antarctic Treaty and other related agreements, collectively called the Antarctic Treaty System. For the purposes of the Treaty System, Antarctica is defined as all land and ice shelves south of 60°S. The treaty was signed by twelve countries, including the Soviet Union (and later Russia), the United Kingdom, and the United States. It set aside Antarctica as a scientific preserve, established freedom of scientific investigation, environmental protection, and banned military activity on that continent. This was the first arms control agreement established during the Cold War. The Antarctic Treaty prohibits any military activity in Antarctica, such as the establishment of military bases and fortifications, the carrying out of military maneuvers, or the testing of any type of weapon. Military personnel or equipment are permitted only for scientific research or for other peaceful purposes. The only documented land military maneuver was Operation NINETY, undertaken by the Argentine military. The United States military issues the Antarctica Service Medal to military members or civilians who perform research duty in Antarctica. The medal includes a "wintered over" bar issued to those who remain on the continent for two complete six-month seasons. The Antarctic Treaty The main treaty was opened for signature on December 1, 1959, and officially entered into force on June 23, 1961. The original signatories were the 12 countries active in Antarctica during the International Geophysical Year of 1957-58 and willing to accept a U.S. invitation to the conference at which the treaty was negotiated. These countries were Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, the USSR, the United Kingdom, and the United States (which opened the Amundsen-Scott South Pole Station for the International Geophysical Year). Articles of the Antarctic Treaty - Article 1—area to be used for peaceful purposes only; military activity, such as weapons testing, is prohibited, but military personnel and equipment may be used for scientific research or any other peaceful purpose; - Article 2—freedom of scientific investigation and cooperation shall continue; - Article 3—free exchange of information and personnel in cooperation with the United Nations and other international agencies; - Article 4—does not recognize, dispute, or establish territorial claims and no new claims shall be asserted while the treaty is in force; - Article 5—prohibits nuclear explosions or disposal of radioactive wastes; - Article 6—includes under the treaty all land and ice shelves south of 60 degrees 00 minutes south; - Article 7—treaty-state observers have free access, including aerial observation, to any area and may inspect all stations, installations, and equipment; advance notice of all activities and of the introduction of military personnel must be given; - Article 8—allows for jurisdiction over observers and scientists by their own states; - Article 9—frequent consultative meetings take place among member nations; - Article 10—treaty states will discourage activities by any country in Antarctica that are contrary to the treaty; - Article 11—disputes to be settled peacefully by the parties concerned or, ultimately, by the International Court of Justice; - Articles 12, 13, 14—deal with upholding, interpreting, and amending the treaty among involved nations. The main objective of the ATS is to ensure in the interests of all humanity that Antarctica shall continue forever to be used exclusively for peaceful purposes and shall not become the scene or object of international discord. The treaty forbids any measures of a military nature, but not the presence of military personnel per se. It avoided addressing the question of existing territorial claims asserted by some nations and not recognized by others. Other agreements, some 200 recommendations adopted at treaty consultative meetings and ratified by governments, include: - Agreed Measures for the Conservation of Antarctic Fauna and Flora (1964) (entered into force in 1982) - The Convention for the Conservation of Antarctic Seals (1972) - The Convention for the Conservation of Antarctic Marine Living Resources (1980) - The Convention on the Regulation of Antarctic Mineral Resource Activities (1988) (although it was signed in 1988, it was subsequently rejected and never entered into force) - The Protocol on Environmental Protection to the Antarctic Treaty was signed October 4, 1991 and entered into force January 14, 1998; this agreement prevents development and provides for the protection of the Antarctic environment through five specific annexes on marine pollution, fauna, and flora, environmental impact assessments, waste management, and protected areas. It prohibits all activities relating to mineral resources except scientific. Although coal, hydrocarbons, iron ore, platinum, copper, chromium, nickel, gold, and other minerals have been found, they have not been located in large enough quantities to exploit. The 1991 Protocol on Environmental Protection to the Antarctic Treaty also restricts a struggle for resources. In 1998, a compromise agreement was reached to add a 50-year ban on mining until the year 2048, further limiting economic development and exploitation. The primary agricultural activity is the capture and offshore trading of fish. Antarctic fisheries in 2000-01 reported landing 112,934 tons. Small-scale tourism has existed since 1957 and is currently largely self-regulated by the International Association of Antarctica Tour Operators (IAATO). However, not all vessels associated with Antarctic tourism are members of IAATO. Several ships transport people to Antarctica to visit specific scenic locations. A total of 27,950 tourists visited in the 2004-05 Antarctic summer with nearly all of them coming from commercial ships. The number is predicted to increase to over 80,000 by 2010. There has been some recent concern over the adverse environmental and ecosystem effects caused by the influx of visitors. A call for stricter regulations for ships and a tourism quota have been made by some environmentalists and scientists. Antarctic sightseeing flights (which did not land) operated out of Australia and New Zealand until the fatal crash of Air New Zealand Flight 901 in 1979 on Mount Erebus, which killed all 257 aboard. Qantas Airlines resumed commercial overflights to Antarctica from Australia in the mid-1990s. Transportation on the continent has transformed from heroic explorers crossing the isolated remote area of Antarctica on foot to a more open area due to human technologies enabling more convenient and faster transport by land and predominantly air and water. Aircraft and pilots need to be capable of landing on ice, snow, or gravel runways, as there are no paved runways. Landings are generally restricted to the daylight season (Summer months from October to March). Winter landings have been performed at Williams Field but low temperatures mean that aircraft cannot stay on the ice longer than an hour or so, as their skis may freeze to the ice runway. Travel is normally by military aircraft delivering cargo. Major landing fields include: - Williams Field—Serves McMurdo Station and Scott Base. - Pegasus Blue-Ice Runway—Serves McMurdo Station and Scott Base. - Annual Sea-Ice Runway—Serves McMurdo Station and Scott Base. In the Antarctic summer, several companies offer excursions on ice-strengthened vessels to Antarctica. Ice-strengthened (not quite as tough as icebreaker) boats are preferred since icebreakers are round on the bottom—a configuration that amplifies the already massive wave action in the Drake passage. Each year, scientists from 27 different nations conduct experiments not reproducible in any other place in the world. In the summer more than 4,000 scientists operate research stations; this number decreases to nearly 1,000 in the winter. McMurdo Station is capable of housing more than 1,000 scientists, visitors, and tourists. Researchers include biologists, geologists, oceanographers, physicists, astronomers, glaciologists, and meteorologists. Geologists tend to study plate tectonics, meteorites from space, and resources from the breakup of the super continent Gondwanaland. Glaciologists in Antarctica are concerned with the study of the history and dynamics of floating ice, seasonal snow, glaciers, and ice sheets. Biologists, in addition to examining the wildlife, are interested in how harsh temperatures and the presence of people affect adaptation and survival strategies in a wide variety of organisms. Medical physicians have made discoveries concerning the spreading of viruses and the body's response to extreme seasonal temperatures. Astrophysicists at Amundsen-Scott South Pole Station study the celestial dome and cosmic microwave background radiation. Many astronomical observations are better made from the interior of Antarctica than from most surface locations because of the high elevation, which results in a thin atmosphere and low temperature, which minimizes the amount of water vapor in the atmosphere, thus allowing for a view of space clearer than anywhere else on Earth. Antarctic ice serves as both the shield and the detection medium for the largest neutrino telescope in the world, built 2 km below Amundsen-Scott station. Since the 1970s, an important focus of study has been the ozone layer in the atmosphere above Antarctica. In 1985, three British Scientists working on data they had gathered at Halley Station on the Brunt Ice Shelf discovered the existence of a hole in this layer. In 1998, NASA satellite data showed that the Antarctic ozone hole was the largest on record, covering 27 million square kilometers. It was eventually determined that the destruction of the ozone was caused by chlorofluorocarbons emitted by human products. With the ban of CFCs in the Montreal Protocol of 1989, it is believed that the ozone hole will close up over the next fifty years. Meteorites from Antarctica are an important area of study about material formed early in the solar system; most are thought to come from asteroids, but some may have originated on larger planets. The first Antarctic meteorites were found in 1912. In 1969, a Japanese expedition discovered nine meteorites. Most of these meteorites have fallen onto the ice sheet in the last million years. Motion of the ice sheet tends to concentrate the meteorites at blocking locations such as mountain ranges, with wind erosion bringing them to the surface after centuries beneath accumulated snowfall. Compared with meteorites collected in more temperate regions on Earth, the Antarctic meteorites are well-preserved. This large collection of meteorites allows a better understanding of the abundance of meteorite types in the solar system and how meteorites relate to asteroids and comets. New types of meteorites and rare meteorites have been found. Among these are pieces blasted off the moon, and probably Mars, by impacts. These specimens, particularly ALH84001 discovered by ANSMET, are at the center of the controversy about possible evidence of microbial life on Mars. Because meteorites in space absorb and record cosmic radiation, the time elapsed since the meteorite hit the Earth can be determined from laboratory studies. The elapsed time since fall, or terrestrial residence age, of a meteorite represents more information that might be useful in environmental studies of Antarctic ice sheets. In 2006, a team of researchers from Ohio State University used gravity measurements by NASA's Gravity Recovery and Climate Experiment (GRACE) satellites to discover the 300-mile-wide Wilkes Land crater, which probably formed about 250 million years ago. - ↑ National Geophysical Data Center, NOAA Satellite and Information Services. Retrieved May 25, 2007. - ↑ The Mariner's Museum, Age of Exploration. Retrieved May 25, 2007. - ↑ SouthPole.com, James Clark Ross. Retrieved May 25, 2007. - ↑ Australian Antarctic Division, Tannatt William Edgeworth David. Retrieved May 25, 2007. - ↑ SouthPole.com, Roald Amundsen. Retrieved May 25, 2007. - ↑ National Science Foundation, Scientists Discover Undersea Volcano Off Antarctica. Retrieved May 25, 2007. - ↑ Lisa Asselbergs, Creatures of Antarctica. Retrieved May 25, 2007. - ↑ Scientific Committee on Antarctic Research, The Antarctic Treaty System: An Introduction. Retrieved May 25, 2007. - ↑ Antarctica Institute of Argentina, Argentina in Antarctica. Retrieved May 25, 2007. - ↑ International Association of Antarctica TourOperations, Tourism Statistics. Retrieved May 25, 2007. - ↑ Antarctic Connection, Science in Antarctica. Retrieved May 25, 2007. - ↑ NASA Astromaterials Curation, Meteorites from Antarctica. Retrieved May 25, 2007. - ↑ Ohio State Research, Bang in Antarctica. Retrieved May 25, 2007. - Bledsoe, Lucy Jane. 2006. How to survive in Antarctica. New York: Holiday House. ISBN 0823418901 - Ley, Willy. 1962. The poles. Life nature library. New York: Time, Inc. - Petersen, David. 1998. Antarctica. A true book. New York: Children's Press. ISBN 0516207709 - Robinson, Kim Stanley. 1998. Antarctica. New York: Bantam Books. ISBN 0553100637 - United States. 2002. Antarctic region. Washington, DC: Central Intelligence Agency. All links retrieved October 16, 2012. - Antarctica. The Open Directory Project. - Discovering Antarctica. - Antarctica Pictures, Information and Travel Cool Antarctica. 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: Note: Some restrictions may apply to use of individual images which are separately licensed.
The national effort made by black people and their supporters in the 1950s and 1960s to eliminate segregation and gain equal rights. The first large episode in the movement, a boycott of the city buses in Montgomery, Alabama, was touched off by the refusal of one black woman, Rosa Parks, to give up her seat on a bus to a white person. A number of sit-ins and similar demonstrations followed. A high point of the civil rights movement was a rally by hundreds of thousands in Washington, D.C., in 1963, at which a leader of the movement, Martin Luther King, Jr., gave his “I have a dream” speech. The federal Civil Rights Act of 1964 authorized federal action against segregation in public accommodations, public facilities, and employment. The Voting Rights Act of 1965 was passed after large demonstrations in Selma, Alabama, which drew some violent responses. The Fair Housing Act, prohibiting discrimination by race in housing, was passed in 1968. After such legislative victories, the civil rights movement shifted emphasis toward education and changing the attitudes of white people. Some civil rights supporters turned toward militant movements (see Black Power), and several riots erupted in the late 1960s over racial questions (see Watts riots). The Bakke decision of 1978 guardedly endorsed affirmative action. But he also reminded the younger members of the crowd of the civil rights movement of the last century. I was speaking to Lee Daniels who called the gay rights movement “the civil rights movement of our time.” Yes, Lewis behaved honorably during the civil rights movement. In the 1950s, said Maya, their mother studied at Berkeley and worked as a student organizer during the civil rights movement. Some Christians opposed the civil rights movement while others marched and advocated for racial equality. In 175 well-chosen words, he sums up the trials and the grit and bravery of the civil rights movement. First, if only for the constancy and fervor of its demands, was the civil rights movement. Time, however, was precisely what Forrestal lacked, given the increasing political strength of the civil rights movement. World War II marked the beginning of an important step in the evolution of the civil rights movement. The influence of the church on the militant phase of the civil rights movement is one of the movement's salient characteristics.
Ladder logic was originally a written method to document the design and construction of relay racks as used in manufacturing and process control. Each device in the relay rack would be represented by a symbol on the ladder diagram with connections between those devices shown. In addition, other items external to the relay rack such as pumps, heaters, and so forth would also be shown on the ladder diagram. Ladder logic has evolved into a programming language that represents a program by a graphical diagram based on the circuit diagrams of relay logic hardware. Ladder logic is used to develop software for programmable logic controllers (PLCs) used in industrial control applications. The name is based on the observation that programs in this language resemble ladders, with two vertical rails and a series of horizontal rungs between them. While ladder diagrams were once the only available notation for recording programmable controller programs, today other forms are standardized in IEC 61131-3 (For example, as an alternative to the graphical ladder logic form, there is also a more assembly language like format called Instruction list within the IEC 61131-3 standard.). Ladder logic is widely used to program PLCs, where sequential control of a process or manufacturing operation is required. Ladder logic is useful for simple but critical control systems or for reworking old hardwired relay circuits. As programmable logic controllers became more sophisticated it has also been used in very complex automation systems. Often the ladder logic program is used in conjunction with an HMI program operating on a computer workstation. The motivation for representing sequential control logic in a ladder diagram was to allow factory engineers and technicians to develop software without additional training to learn a language such as FORTRAN or other general purpose computer language. Development, and maintenance, was simplified because of the resemblance to familiar relay hardware systems. Implementations of ladder logic have characteristics, such as sequential execution and support for control flow features, that make the analogy to hardware somewhat inaccurate. This argument has become less relevant given that most ladder logic programmers have a software background in more conventional programming languages. Ladder logic can be thought of as a rule-based language rather than a procedural language. A "rung" in the ladder represents a rule. When implemented with relays and other electromechanical devices, the various rules "execute" simultaneously and immediately. When implemented in a programmable logic controller, the rules are typically executed sequentially by software, in a continuous loop (scan). By executing the loop fast enough, typically many times per second, the effect of simultaneous and immediate execution is achieved, if considering intervals greater than the "scan time" required to execute all the rungs of the program. Proper use of programmable controllers requires understanding the limitations of the execution order of rungs. The language itself can be seen as a set of connections between logical checkers (contacts) and actuators (coils). If a path can be traced between the left side of the rung and the output, through asserted (true or "closed") contacts, the rung is true and the output coil storage bit is asserted (1) or true. If no path can be traced, then the output is false (0) and the "coil" by analogy to electromechanical relays is considered "de-energized". The analogy between logical propositions and relay contact status is due to Claude Shannon. Ladder logic has contacts that make or break circuits to control coils. Each coil or contact corresponds to the status of a single bit in the programmable controller's memory. Unlike electromechanical relays, a ladder program can refer any number of times to the status of a single bit, equivalent to a relay with an indefinitely large number of contacts. So-called "contacts" may refer to physical ("hard") inputs to the programmable controller from physical devices such as pushbuttons and limit switches via an integrated or external input module, or may represent the status of internal storage bits which may be generated elsewhere in the program. Each rung of ladder language typically has one coil at the far right. Some manufacturers may allow more than one output coil on a rung. —[ ]—Normally open contact, closed whenever its corresponding coil or an input which controls it is energized. (Open contact at rest) —[\]—Normally closed ("not") contact, closed whenever its corresponding coil or an input which controls it is not energized. (Closed contact at rest) —( )—Normally inactive coil, energized whenever its rung is closed. (Inactive at rest) —(\)—Normally active ("not") coil, energized whenever its rung is open. (Active at rest) The "coil" (output of a rung) may represent a physical output which operates some device connected to the programmable controller, or may represent an internal storage bit for use elsewhere in the program. A way to recall these is to imagine the checkers (contacts) as a push button input, and the actuators (coils) as a light bulb output. The presence of a slash within the checkers or actuators would indicate the default state of the device at rest. ------[ ]--------------[ ]----------------( ) Key switch 1 Key switch 2 Door motor The above realizes the function: Door motor = Key switch 1 AND Key switch 2 This circuit shows two key switches that security guards might use to activate an electric motor on a bank vault door. When the normally open contacts of both switches close, electricity is able to flow to the motor which opens the door. ------[ ]--------------[\]----------------( ) Close door Obstruction Door motor This circuit shows a push button that closes a door, and an obstruction detector that senses if something is in the way of the closing door. When the normally open push button contact closes and the normally closed obstruction detector is closed (no obstruction detected), electricity is able to flow to the motor which closes the door. --+-------[ ]-------+-----------------( ) \| Exterior unlock \| Unlock \| \| +-------[ ]-------+ Interior unlock The above realizes the function: Unlock = Interior unlock OR Exterior unlock In common industrial latching start/stop logic we have a "Start" button to turn on a motor contactor, and a "Stop" button to turn off the contactor. When the "Start" button is pushed the input goes true, via the "Stop" button NC contact. When the "Run" input becomes true the seal-in "Run" NO contact in parallel with the "Start" NO contact will close maintaining the input logic true (latched or sealed-in). After the circuit is latched the "Stop" button may be pushed causing its NC contact to open and consequently the input to go false. The "Run" NO contact then opens and the circuit logic returns to its inactive state. --+----[ ]--+----[\]----( ) \| Start \| Stop Run \| \| +----[ ]--+ Run -------[ ]--------------( ) Run Motor This latch configuration is a common idiom in ladder logic. In ladder logic it is referred to as seal-in logic. The key to understanding the latch is in recognizing that "Start" switch is a momentary switch (once the user releases the button, the switch is open again). As soon as the "Run" solenoid engages, it closes the "Run" NO contact, which latches the solenoid on. The "Start" switch opening up then has no effect. For safety reasons, an Emergency-Stop and/or Stop should be hardwired in series with the Start switch, and the relay logic should reflect this. --[\]----[\]----+--[ ]--+---------( ) ES Stop \| Start \| Motor \| \| +--[ ]--+ Run Here is an example of what two rungs in a ladder logic program might look like. In real world applications, there may be hundreds or thousands of rungs. Typically, complex ladder logic is 'read' left to right and top to bottom. As each of the lines (or rungs) are evaluated the output coil of a rung may feed into the next stage of the ladder as an input. In a complex system there will be many "rungs" on a ladder, which are numbered in order of evaluation. 1. ----[ ]---------+----[ ]-----+----( ) Switch \| HiTemp \| A/C \| \| +----[ ]-----+ Humid 2. ----[ ]----[\]--------------------( ) A/C Heat Cooling This represents a slightly more complex system for rung 2. After the first line has been evaluated, the output coil "A/C" is fed into rung 2, which is then evaluated and the output coil "Cooling" could be fed into an output device "Compressor" or into rung 3 on the ladder. This system allows very complex logic designs to be broken down and evaluated. Additional functionality can be added to a ladder logic implementation by the PLC manufacturer as a special block. When the special block is powered, it executes code on predetermined arguments. These arguments may be displayed within the special block. +-------+ -----[ ]--------------------+ A +---- Remote unlock +-------+ Remote counter +-------+ -----[ ]--------------------+ B +---- Interior unlock +-------+ Interior counter +--------+ --------------------+ A + B +----------- \| into C \| +--------+ Adder In this example, the system will count the number of times that the interior and remote unlock buttons are pressed. This information will be stored in memory locations A and B. Memory location C will hold the total number of times that the door has been unlocked electronically. PLCs have many types of special blocks. They include timers, arithmetic operators and comparisons, table lookups, text processing, PID control, and filtering functions. More powerful PLCs can operate on a group of internal memory locations and execute an operation on a range of addresses, for example, to simulate a physical sequential drum controller or a finite state machine. In some cases, users can define their own special blocks, which effectively are subroutines or macros. The large library of special blocks along with high speed execution has allowed use of PLCs to implement very complex automation systems. Ladder notation is best suited to control problems where only binary variables are required and where interlocking and sequencing of binary is the primary control problem. Like all parallel programming languages, the sequential order of operations may be undefined or obscure; logic race conditions are possible which may produce unexpected results. Complex rungs are best broken into several simpler steps to avoid this problem. Some manufacturers avoid this problem by explicitly and completely defining the execution order of a rung, however programmers may still have problems fully grasping the resulting complex semantics. Analog quantities and arithmetical operations are clumsy to express in ladder logic and each manufacturer has different ways of extending the notation for these problems. There is usually limited support for arrays and loops, often resulting in duplication of code to express cases which in other languages would call for use of indexed variables. As microprocessors have become more powerful, notations such as sequential function charts and function block diagrams can replace ladder logic for some limited applications. Some newer PLCs may have all or part of the programming carried out in a dialect that resembles BASIC , C, or other programming language with bindings appropriate for a real-time application environment.
What is uremia? Uremia (or uraemia) is a disorder of kidney function that occurs when the kidneys cannot properly remove urea from the body, so waste from urine accumulates in the blood and another series of diseases can occur. What are the symptoms of uremia? The main symptoms of this pathology are: - asterixis (tremors) - lethargy (prolonged drowsiness) - hyperreflexia (increased osteotendinous reflexes) - uremic flush (metallic and bitter taste in the mouth) - serositis, especially pericarditis (inflammation of the tissue around the heart) - nausea and vomiting - white or reddened tongue What are the causes of uremia? The main cause of uremia is kidney failure. Kidney failure can be acute or it can be chronic. Acute kidney failure generally follows a severe infection, significant blood loss, severe dehydration or sometimes from kidney stones blocking the drainage of urine from the kidneys. Chronic kidney failure can occur as a result of type 2 diabetes or polycystic kidney disease. Rarer causes of kidney failure include a high protein diet, gastrointestinal bleeding, drug use, bladder rupture, dehydration or chronic pyelonephritis. What is the treatment for uremia? In some cases, if the uremia is due to excess protein or hypotension, it can be treated with a change in diet and prescribing drugs. However, this condition can be very serious, so it is usually treated with more invasive techniques: - Dialysis: this consists of removing waste and excess fluid from the blood through the blood vessels around the walls of the abdomen. - Kidney transplant: this consists of replacing the damaged kidney with a healthy one so that proper renal function is restored.
What have the Romans ever done for us? Ancient Rome is well known for its contribution to the modern world in areas such as sanitation, aqueducts, and roads, but the extent to which it has shaped modern thinking about sexual identity is not nearly so widely recognized. Although LGBT (lesbian, gay, bisexual, transgender) people owe a lot to the Romans, the importance of Rome in this respect has been largely overlooked by historians. Attention has focused instead on ancient Greece as a model of a society in which same-sex relationships were accepted and even celebrated. Oscar Wilde famously defended himself while on trial for his sexual behaviour by making reference to the Greek philosopher Plato, who had made the “affection of an elder for a younger man … the very basis of his philosophy.” Early gay activists of the late nineteenth and twentieth centuries, such as John Addington Symonds, George Cecil Ives, and Edward Carpenter also downplayed the sexual element in homosexual relations by promoting a similarly noble ideal of Greece, where love between males played an important role in the education of young citizens. These activists saw Rome as a corrupt copy of Greece. It was the playground of sexually incontinent emperors such as Nero and Heliogabalus (or Elagabalus), who took decadence to new heights and outraged public opinion by openly marrying men. Roman poets such as Catullus and Martial wrote graphically about sex, while the novelist Petronius had conjured up a riotous world of orgies, cross-dressing, and bathhouses where spectators applauded at the sight of an enormous penis. Apologists for homosexual relations wanted to distance themselves from excesses of this kind in order to gain acceptance for their own desires and therefore used Roman ‘vice’ as a contrast to Greek ‘virtue’. This vision of Rome as a decadent society was appalling to some, but it is also easy to see why it was appealing to others. Wilde talked of Plato in public, but he also had his hair cut in the style of a decadent emperor, and privately referred to the days before his downfall as his ‘Neronian hours.’ The anonymously published 1893 pornographic novel Teleny (which has sometimes been attributed to Wilde) makes clear links between its own fascination with large penises and Rome’s priapic preoccupations. The ancient Greeks, in contrast, had depicted boys with small penises as a vision of perfect male beauty in their art. Teleny also features an all-male orgy at which the participants (some of whom are cross-dressed) are aroused by images that recreate sexually explicit Roman wall-paintings. The star-crossed yet devoted male lovers at the heart of this novel are cast as the emperor Hadrian and his doomed beloved, Antinoüs, the beautiful young man who was commemorated by Hadrian in statues and images all around the empire. To this day, the figures of the emperor and his slave, the Roman gladiator, and the legionary, remain staples of gay pornography, eroticizing differences in power between men and fitting well into a modern gay aesthetic that places a high value on hyper-masculinity. Lesbian desire and the women who feel it are repeatedly referred to in hostile terms in Roman literature. The satirical poet Juvenal is particularly scathing about women who have sex with each other, but his disapproval didn’t prevent Anne Lister (1791-1840) of Shibden Hall, near Halifax from finding his poetry on the theme arousing. She also used his poetry and references to other Roman poets who had discussed lesbian desire to sound out other women’s tendencies. Rome also offers models for transgendered identities, sexual fluidity, and a range of sexual configurations and possibilities. Poet laureate Carol Ann Duffy, for example, plays on the poet Ovid’s portrait of one of the many gender-bending characters from his Metamorphoses, in her 1999 poem “From Mrs Tiresias” (in the collection The World’s Wife). Ovid’s Tiresias was transformed from being a man into a woman, and then back again, and clearly made the most of this gender fluidity, since he reveals that sex is more pleasurable as a woman. Rome, then, has offered LGBT people throughout history a model of a society in which same-sex desires were highly visible and openly discussed, as well as a number of authors who were very frank indeed about sex and sexuality, and who wrote about taboo topics in many other traditions, such as transvestism, transgendered individuals, and sex changes. Today, Rome offers us a sex-positive and multi-faceted vision of sexual possibilities and permutations that challenges the more famous, but also more limited, version of Greek homosexuality that has played such an important role in LGBT history. Featured image credit: The Roses of Heliogabalus by Lawrence Alma-Tadema, 1888. Public domain via Wikimedia Commons.
Question: "What is Reformation Day?" Answer: Reformation Day is a Protestant religious holiday celebrated on October 31. It recognizes the day German monk Martin Luther nailed his 95 Theses to the door of the Wittenberg Church in 1517. This act is commemorated as the official starting point of the Protestant Reformation. Officially, Reformation Day has been commemorated since 1567. Exact dates for the holiday varied until after the two hundredth celebration in 1717 when October 31 became the official date of celebration in Germany and later expanded internationally. Within the Lutheran tradition, Reformation Day is considered a lesser holiday and is officially named “The Festival of the Reformation.” Most Lutheran churches (and others who celebrate this day) commemorate it on the Sunday prior to October 31. The impact of Martin Luther and the Protestant Reformation has been enormous on global Christianity. In contrast to the extra-biblical traditions and works-based practices of Roman Catholicism, Luther called the Church back to the good news of salvation by grace alone through faith alone (Ephesians 2:8-9). Luther believed the Word of God was the supreme authority for the Christian faith, rather than tradition or papal decrees. In the process of bringing the Scriptures to the common person, Luther translated the Bible into German, published numerous books and sermons of biblical teachings, and composed numerous hymns based on biblical themes. Many of his hymns are still sung today. Luther was brought to trial before the church, and the court attempted to force him to recant. Luther’s response is often quoted: “I cannot choose but adhere to the Word of God, which has possession of my conscience; nor can I possibly, nor will I even make any recantation, since it is neither safe nor honest to act contrary to conscience! Here I stand; I cannot do otherwise, so help me God! Amen.” From Germany, the Protestant Reformation expanded through Europe, influencing the work of John Calvin in Geneva, Ulrich Zwingli in Zurich, and John Knox in Scotland. The Reformation Luther led also sparked the Anabaptist (free church) movement and the English Reformation. These movements, in turn, influenced the spread of Christianity to the Americas and throughout the world where European exploration took place. South Africa, India, Australia, and New Zealand all felt the impact of Luther’s hammer in Wittenberg. Robert Rothwell has noted, “Today, Luther’s legacy lives on in the creeds and confessions of Protestant bodies worldwide. As we consider his importance this Reformation Day, let us equip ourselves to be knowledgeable proclaimers and defenders of biblical truth. May we be eager to preach the Gospel of God to the world and thereby spark a new reformation of church and culture.” Reformation Day remains a central rallying point for all of those who choose to follow Christ by faith according to His Word. The holiday commemorates the actions of a man who was willing to stand against the ideas of his day and to present God’s Word as our guide for salvation (John 3:16) and Christian living.
Scientists have been probing individual regions of the brain for over a century, exploring their function by zapping them with electricity and temporarily putting them out of action. Despite this, they have never been able to turn off consciousness – until now. Although only tested in one person, the discovery suggests that a single area – the claustrum – might be integral to combining disparate brain activity into a seamless package of thoughts, sensations and emotions. It takes us a step closer to answering a problem that has confounded scientists and philosophers for millennia – namely how our conscious awareness arises. Many theories abound but most agree that consciousness has to involve the integration of activity from several brain networks, allowing us to perceive our surroundings as one single unifying experience rather than isolated sensory perceptions. One proponent of this idea was Francis Crick, a pioneering neuroscientist who earlier in his career had identified the structure of DNA. Just days before he died in July 2004, Crick was working on a paper that suggested our consciousness needs something akin to an orchestra conductor to bind all of our different external and internal perceptions together. With his colleague Christof Koch, at the Allen Institute for Brain Science in Seattle, he hypothesised that this conductor would need to rapidly integrate information across distinct regions of the brain and bind together information arriving at different times. For example, information about the smell and colour of a rose, its name, and a memory of its relevance, can be bound into one conscious experience of being handed a rose on Valentine’s day. The pair suggested that the claustrum – a thin, sheet-like structure that lies hidden deep inside the brain – is perfectly suited to this job (Philosophical Transactions of The Royal Society B, doi.org/djjw5m). It now looks as if Crick and Koch were on to something. In a study published last week, Mohamad Koubeissi at the George Washington University in Washington DC and his colleagues describe how they managed to switch a woman’s consciousness off and on by stimulating her claustrum. The woman has epilepsy so the team were using deep brain electrodes to record signals from different brain regions to work out where her seizures originate. One electrode was positioned next to the claustrum, an area that had never been stimulated before. When the team zapped the area with high frequency electrical impulses, the woman lost consciousness. She stopped reading and stared blankly into space, she didn’t respond to auditory or visual commands and her breathing slowed. As soon as the stimulation stopped, she immediately regained consciousness with no memory of the event. The same thing happened every time the area was stimulated during two days of experiments (Epilepsy and Behavior, doi.org/tgn). To confirm that they were affecting the woman’s consciousness rather than just her ability to speak or move, the team asked her to repeat the word “house” or snap her fingers before the stimulation began. If the stimulation was disrupting a brain region responsible for movement or language she would have stopped moving or talking almost immediately. Instead, she gradually spoke more quietly or moved less and less until she drifted into unconsciousness. Since there was no sign of epileptic brain activity during or after the stimulation, the team is sure that it wasn’t a side effect of a seizure. Koubeissi thinks that the results do indeed suggest that the claustrum plays a vital role in triggering conscious experience. “I would liken it to a car,” he says. “A car on the road has many parts that facilitate its movement – the gas, the transmission, the engine – but there’s only one spot where you turn the key and it all switches on and works together. So while consciousness is a complicated process created via many structures and networks – we may have found the key.” Awake but unconscious Counter-intuitively, Koubeissi’s team found that the woman’s loss of consciousness was associated with increased synchrony of electrical activity, or brainwaves, in the frontal and parietal regions of the brain that participate in conscious awareness. Although different areas of the brain are thought to synchronise activity to bind different aspects of an experience together, too much synchronisation seems to be bad. The brain can’t distinguish one aspect from another, stopping a cohesive experience emerging. Since similar brainwaves occur during an epileptic seizure, Koubeissi’s team now plans to investigate whether lower frequency stimulation of the claustrum could jolt them back to normal. It may even be worth trying for people in a minimally conscious state, he says. “Perhaps we could try to stimulate this region in an attempt to push them out of this state.” Anil Seth, who studies consciousness at the University of Sussex, UK, warns that we have to be cautious when interpreting behaviour from a single case study. The woman was missing part of her hippocampus, which was removed to treat her epilepsy, so she doesn’t represent a “normal” brain, he says. However, he points out that the interesting thing about this study is that the person was still awake. “Normally when we look at conscious states we are looking at awake versus sleep, or coma versus vegetative state, or anaesthesia.” Most of these involve changes of wakefulness as well as consciousness but not this time, says Seth. “So even though it’s a single case study, it’s potentially quite informative about what’s happening when you selectively modulate consciousness alone.” “Francis would have been pleased as punch,” says Koch, who was told by Crick’s wife that on his deathbed, Crick was hallucinating an argument with Koch about the claustrum and its connection to consciousness. “Ultimately, if we know how consciousness is created and which parts of the brain are involved then we can understand who has it and who doesn’t,” says Koch. “Do robots have it? Do fetuses? Does a cat or dog or worm? This study is incredibly intriguing but it is one brick in a large edifice of consciousness that we’re trying to build.”
Connect the conjunctions This activity is based on a piece of literature you are studying. Glue onto a LARGE dice 6 pictures taken from the book being studied. One per face. Onto another LARGE dice glue 6 conjunctions, one per face. Example: because, and, hence, etc... To each conjunction allocate a point or points, the harder the conjunction the more the points.So that "and" might have 1 point, and "as a result of" might have 6 points. In small groups (3-4 players) each child takes it in turn to roll both dice and then make up a sentence concerning the picture using the conjunction. If the other players think the sentence makes sense then the player gets the number of points attached to that particular conjunction. The player with the most points when the game is halted is the winner. World's Best Jobs! Dave's ESL Cafe Copyright © 2008 Dave Sperling. All Rights Reserved.
British Quakers in Parliament in the Nineteenth Century In 1698, John Archdale of Upperside Meeting, (now Chilterns), in Buckinghamshire, was the first Quaker to be elected as an MP. However he could not take up his seat because he would not swear an oath of allegiance to the King, a requirement for all MPs at that time. How could a person who openly refused to swear an oath to uphold the monarch be trusted in Parliament? This refusal kept Quakers out of Parliament until an alternative was finally found in the nineteenth century. Joseph Pease (1799-1872) was elected to represent South Durham in 1832, and his election catalysed change. A committee was formed to try to find a way round his ‘oath problem’. The resulting 1832 Reform Bill enabled Quakers to express their loyalty through affirmation rather than an oath. (To this day, many Quakers do this in several contexts where oath taking is the norm. ) Joseph Pease duly affirmed, and became the first Quaker MP. He worked with Thomas Fowell Buxton (whose mother was a Quaker) in the anti-slavery movement. In 1841 he left politics and in 1860 he became the President of the Peace Society. Six other members of the Pease family also became MPs, including Henry and Arthur Pease, mentioned below. John Bright (1811–1889) was the second Quaker MP. In 1843 he was elected to represent the City of Durham. He was a very accomplished orator and was famous for his passionate speeches. He joined with MP Richard Cobden in a campaign that succeeded in 1846 in repealing the Corn Laws that were keeping bread prices high. Bright led the Peace Society in opposing the Crimean War and lost his seat in 1850. His unwillingness to modify his principles did not make him popular with his fellow MPs. He was re-elected soon afterwards and remained in Parliament for the next thirty years. During the American Civil War he helped to prevent Britain from breaking the blockade of Confederate ports by force. In 1868 Prime Minister William Gladstone invited him to join his cabinet, the first Quaker to do so. In 1882 he resigned from a second cabinet appointment over British Military intervention in Egypt. His brother Jacob was also an MP. John Ellis (1789-1862) another Quaker became the MP for Leicester from 1848 to 1852 and joined John Bright in Parliament. He was a liberal reformer who had attended the1840 anti-slavery convention in London. Charles Gilpin (1815-1874) was elected to Parliament to represent Northampton in 1857. He remained in Parliament for seventeen years. He served as Secretary to the Poor Law Board (which oversaw workhouses, and provided basic poor relief) until 1865, When he was appointed, John Bright disapproved, because of the nature of the work, and is said to have told Gilpin "Thou'd better have a rope put around thy neck". This is especially ironic since Gilpin was an active campaigner against capital punishment. For the rest of the nineteenth century there was a disproportionate number of Quaker MPs. Among them were: Henry Pease (1807-1881), son of Edward Pease, the railway pioneer, represented Durham South in Parliament from 1857 until 1865. He was President of the Peace Society and visited the Tsar of Russia with Joseph Sturge, in an attempt to prevent the Crimean War. Edmund Backhouse was elected as MP for Darlington in 1867 serving until 1880. Unlike Bright and Gilpin he was not an orator but he was reputed to be very able and conscientious having common sense and sound judgement. Theodore Fry (1836-1912), son of chocolatier Francis Fry, succeeded him. He was MP for Darlington from 1880 to 1895. Arthur Pease (1837-1898), son of Joseph Pease MP, was MP for Whitby from 1880 to 1885 and for Darlington from 1895 until 1896. He was a member of the Royal Commission on Opium in India from 1893-1895. John Pennington Thomasson (1841-1904) represented Bolton in Parliament from 1880 to 1885. He was a great philanthropist and gave over £30,000 to improve education in Bolton. George William Palmer (1851-1913), whose family were partners in the biscuit makers Huntley and Palmers, was prominent in local government prior to entering Parliament in 1892. He was defeated in the 1895 election but regained his seat in 1898 and remained in Parliament until 1904. Quaker parliamentarians were mostly Liberals.
17 October 1990 The Royal Swedish Academy of Sciences has decided to award the 1990 Nobel Prize in Physics jointly to Professors Jerome I. Friedman and Henry W. Kendall both of the Massachusetts Institute of Technology, Cambridge, MA, USA, and Richard E. Taylor of Stanford University, Stanford, CA, USA, for their pioneering investigations concerning deep inelastic scattering of electrons on protons and bound neutrons, which have been of essential importance for the development of the quark model in particle physics. Professors Jerome I. Friedman and Henry W. Kendall, both of the Massachusetts Institute of Technology (MIT), and Richard E. Taylor, of the Stanford Linear Accelerator Center (SLAC), share this year's Nobel Prize in Physics. The value of the prize is 4 million Swedish crowns. The three prizewinners were key persons in a research team which in a series of investigations found clear signs that there exists an inner structure in the protons and neutrons of the atomic nucleus. What has become known as the "SLAC-MIT experiment" paved the way for further investigations of the innermost structures of matter. Ever since the beginning of this century, researchers have studied the inner structure of atoms. Our knowledge has increased successively, among other ways through the discovery (around 1910-1930) of the nucleus of the atom and its nucleons. During the 1950s there arrived on the scene a large number of what were termed hadrons, whose properties resembled those of nucleons. To reduce these to order, the concept of quarks was introduced, at the beginning of the 1960s. Yet it was impossible to see any traces of quarks in nature until the SLAG-MIT The discovery was made when protons and neutrons were illuminated with beams from a giant "electron microscope" - a two-mile-long accelerator at SLAC in California, USA. The inner structure was interpreted to mean that quarks form the fundamental building blocks of protons and neutrons. The electrically neutral "glue" binding the quarks together is called gluons. All matter on earth, including our human bodies, consists to more than 99% of quarks with associated gluons. The little that remains is electrons. The prizewinners' contributions The work now rewarded was carried out at the end of the 1960s and the beginning of the 1970s by a group of researchers from MIT and SLAC. The work was a continuation of earlier investigations in which, using the electron as a probe, the structure of nucleons (protons and neutrons) was studied. Unlike in earlier investigations, electron beams of record-high energies were now available. These beams were supplied by a two-mile-long linear accelerator at SLAC, which afforded a "microscope" of higher resolution than earlier. No new phenomenon was expected: the experiment was fairly generally regarded as routine. Electron scattering against nucleons, but at lower electron energies, had been performed over two decades, and it was thought that enough was known about the structure of nucleons - a view that proved to be entirely false. The essence of the SLAG-MIT experiments was to observe how a beam of electrons at high velocities (energy from 4 GeV to 21 GeV) is affected when it is led through a target consisting either of liquid hydrogen or of deuterium. The scattered electrons were recorded using two large magnetic spectrometers. One of these was used for observing electrons scattered at 6 and 10 degrees, and the other for greater scattering angles (18, 26 and 34 degrees). As well as the scattering angle, the energy of the electrons was measured with the spectrometers. Collaboration between SLAC and MIT started at the beginning of 1967, with the study of so called elastic scattering against protons (the process e + p - > e + p, in which the electron bounces against the proton as if they were both rubber balls). Similar experiments at lower electron energies had shown that the nucleons behaved like "soft" structures which were only able to scatter the electrons at small angles. The new results from elastic scattering confirmed the earlier measurements. The probability of obtaining a large scattering angle was found to be very small. Following this conventional initial phase, it was decided to have a look also at what was termed inelastic electron scattering, e + p -> e + X, where X is not necessarily a proton. Such processes were known from experiments at lower energies, and nothing fundamentally new was to be expected. However, the researchers found to their amazement that the probability of deep inelastic scattering - where the incident electron loses a large part of its original energy and emerges at a large angle in relation to the original direction - was considerably greater than expected. At first they believed the result was incorrect or misinterpreted. One suspected source of error was so-called radiation corrections - the incident or departing electron could radiate away part of its energy in the form of light, which they had not observed, and which could therefore, they thought, have caused them to misinterpret what had happened. But after careful work on the part of the research group it gradually became clear that an inner nucleonic structure, termed hard scattering centres, had been observed. Here was a repetition, although at a deeper level, of one of the most dramatic events in the history of physics, the discovery of the nucleus of the atom. At the beginning of our century Hans Geiger and Ernest Marsden performed a series of experiments in which they measured the scattering of alpha particles passing through a thin metal foil. Geiger and Marsden (1909) found to their surprise that some of the alpha particles were scattered at very large angles, such as 90°, to their original direction. The head in Manchester, where Geiger and Marsden were working, was Ernest Rutherford, one of the most eminent physicists of the time and winner of the 1908 Nobel Prize in Chemistry. Rutherford undertook a systematic theoretical investigation of Geiger's and Marsden's results and those of similar experiments with beta particles (as electrons were called at the time). In these, the no-less-amazing phenomenon had been discovered that a small fraction of the incident electrons boomeranged back after impact. Rutherford showed in a classic paper (1911) that the observations made did not agree with the current picture of the atom - a soft, jelly-like sphere in which the positive and negative charges were diffusely distributed. Such a soft target could at most produce a small deflection of the incident particles. He also found that the probability of many small deflections adding to achieve a large deflection was vanishingly small. After careful comparison of the data with theoretical expectations he concluded that "considering the evidence as a whole, it seems simplest to suppose that the atom contains a central charge distributed through a very small volume, and that the large single deflections are due to the central charge as a whole, and not to its constituents". Thus the concept of atomic nucleus was born. Knowledge of the structure of the nucleus of the atom increased considerably when James Chadwick discovered the neutron in 1932. In the same year, Werner Heisenberg realised that atomic nuclei consist of protons and neutrons. Chadwick was rewarded with the 1935 Nobel Prize in Physics for the discovery of the neutron and Heisenberg received the 1932 Physics Prize for "the creation of quantum mechanics". The realization that the proton and the neutron were building blocks of atomic nuclei represented a giant step forwards in the systematisation of the design of matter. Proton, neutron and electron became the three fundamental building blocks of nature. But as early as 1933-1934 it was suspected that the proton and the neutron were more complicated particles than the electron. The nucleons exhibited unexpectedly large magnetic fields ("anomalous magnetic moments") which could be interpreted in such a way that they contained electric currents. The magnetic properties of the nucleons were first measured by Otto Stern and co-workers. Stern was rewarded with the 1943 Nobel Prize in Physics for "the molecular ray method and his discovery of the magnetic moment of the proton. " During the 1950s, the structure of nucleons was systematically investigated using electron scattering. A series of interesting phenomena were observed, among them that electrons with energies up to 1 GeV saw nucleons as soft "spheres", implying that electron scattering at large angles was very improbable. Measurements were taken of how charge and magnetism are distributed inside the nucleons. Robert Hofstadter played a leading role in these investigations and was rewarded with a 1961 Nobel Prize in Physics for his "pioneering studies of electron scattering in atomic nuclei and for his thereby achieved discoveries concerning the structure of the nucleons". During the 1950s and 1960s the special position of the proton and the neutron as nature's building blocks was questioned. A large number of particles, termed hadrons, were being discovered at this time, and showed similarities to the nucleons. It became a matter of urgency to bring new order to physics so as to understand how hadrons should be classified. After many attempts, the riddle of the hadrons was successfully solved, mainly through the work of Murry Gell-Mann (Nobel Prize in Physics, 1969). The various hadrons were found to be related and to behave as members of a kind of family ("representations of a symmetry-group"). This abstract mathematical description became appreciably easier and more comprehensible when three building blocks were introduced, quarks. Now all the hadrons then known could be built up of these three quarks and their antiparticles. Since this involves great conceptual simplification, the quark concept was immediately taken seriously. Quarks were sought both in nature, e.g. in sea water, meteorites and cosmic rays, and in experiments using high-energy accelerators. But no quarks were to be found. After a time the most popular explanation of the absence of quarks was that they were only "mathematical quantities" included in the equations of physics. The first traces of quarks The SLAG-MIT experiments became the contemporary counterpart of Geiger's and Marsden's experiment. At that time, the scattering of alpha particles at large angles was explained by the existence of a "hard grain" the atomic nucleus - in the middle of the atom. In the modern version, Rutherford's role was assumed chiefly by the theoreticians James D. Bjorken and the late Richard P. Feynman (who received a Nobel Prize in Physics in 1965). This time, the scattering of electrons at large angles was explained by the existence of "hard grains" - quarks - in the nucleons. But the results could not be fully explained using quarks alone. The experiments indicated that there were also electrically neutral components in the nucleons, and there was great eagerness to discover their nature as well. Development was rapid and the neutral components of the nucleons were soon interpreted as gluons, the intermediaries of the strong force. This introduced a new era in the history of physics.
The blue whale (scientifically referred to as balaenoptera musculus) is a large marine mammal that is part of the baleen whale (mysticeti) suborder and is the largest animal alive growing to lengths of up to 100 ft. long and weighing as much as 150 tons or more. In addition to the blue whales massive size it is also one of the loudest animals in existence. In fact a blue whales calls can be heard several miles away and far below the oceans surface. Due to their large size these marine mammals are rarely ever attacked. Other than humans that hunted blue whales during the whaling era the only known predator to the blue whale is a pack of hungry killer whale, however these attacks appear to be rare and rarely successful. In cases where the blue whale is attacked the killer whales tend to go after a young defenseless whale rather than an adult blue whale. Because the blue whale is able to travel through the ocean without worrying about being hunted themselves they are known as apex predators, which means they are predators that do not have any predators of their own. Physical Characteristics and Appearance Although the blue whale is referred to as having a deep blue color when they are at the surface of the water the blue whale actually appears to be a grayish blue. When they dive back under the water the color of the water and the light from the sun make these marine mammals look a deeper blue than they really are. As stated earlier when they are fully matured the blue whale can grow to be over 100 ft. long (average is around 70 – 80 ft.) and weigh more than 150 tons. Even though they are massive animals their body is relatively slim and streamlined for speed and long distance travel allowing them to swim up to 25 miles per hour or more when the feel threatened (average speed is closer to 5 mph). From an overhead position the blue whales oval shaped body resembles that of a submarine, but with with flippers and flukes. The blue whale has a very small triangular dorsal fin as compared to the larger dorsal fin of many other whale species and the flippers which are used for steering are relatively short when compared to the rest of its body. In fact the blue whales flippers only measure about 12% of the whales entire length. Because the blue whale is a baleen whale it does not have any teeth, but instead relies on its baleen plates to capture its prey. The baleen plates have bristles attached to them that act like a fence or net which allows the blue whale to capture its prey while also allowing water to freely move in and out of its mouth. Diet and Hunting Methods When it comes to their diet the blue whale is known to primarily consume krill, although other small ocean creatures such as copepods may also be ingested. In order to maintain their steady diet the blue whale is almost always found in area’s with high concentrations of krill, such as in the Arctic ocean. Because the blue whale does not have teeth they are unable to grab their prey or chew their food so they use a method known as “filter feeding” in order to obtain their prey. Just as the name implies filter feeding involves filtering swarms or groups of krill from the water so that they can easily be consumed. Filter feeding can be though of like using sifter that removes sand or water, but prevents larger objects from passing through the small holes. The blue whale filter feeds works by opening its mouth while it swims towards a large swarm of krill in order to capture as many krill as possible in its mouth. The blue whale then pushes the excess water out with its tongue while the krill stays trapped in the bristles. Once all of the water is removed the whale swallows its prey whole. Despite being such a huge animal the blue whale can only consume small prey due to the fact that its esophagus is too small to consume larger sources of food and it is unable to chew its food and break it down into smaller pieces. In fact the blue whales esophagus is so small that it would not be able to swallow an adult human. Habitat and Migration In the past the blue whale was a very abundant species throughout the world however their overall populations have declined considerably since the whaling era, which was an extremely popular and lucrative business that unfortunately caused mass deaths among the various whale species between the 17th – 20th centuries. The extent of the whale hunting was so severe in fact that it left the blue whale species nearly extinct. Before the whaling era became extremely popular and lucrative it was estimated that between 200,000 and 300,000 blue whales existed in the world’s oceans, however since the whaling era ended estimates are closer to 5,000 – 12,000 whales with some researchers claiming possible higher numbers. While this majestic species can still be seen living in many of the major oceans such as the Antarctic Ocean, Atlantic Ocean, Indian Ocean and the Pacific Ocean their populations have become scarce and largely fragmented because of the mass whaling that occurred in the past. Today these marine mammals tend to be found in colder temperature waters where they can stock up on food in preparation for mating season, however they may also travel to warmer climates during certain times of the year. These whales migrate towards colder polar waters during feeding season when large abundances of krill inhibit the cool waters and will travel to the warmer tropical waters during mating season where they can reproduce and give birth in steady waters. During their migration trips the blue whale can travel thousands of miles from one location to the next. While they migrate most whales will forgo eating food and live primarily off of blubber/body fat and stored calories. The excessive amounts of food they consume during feeding season helps these marine mammals build up their supply of blubber which they’ll rely on for energy during their long trip. Migration trips can last for up to 4 months depending on where they are traveling from or going to. In order to minimize their energy expenditure and limit the amount of calories they use these marine mammals travel an average of 3 – 6 miles per hour during their migration, however when they feel threatened or agitated they can reach speeds of over 30 miles per hour for short bursts. Once the blue whale reaches its mating grounds it will spend the next several months socializing, mating and giving birth to live offspring before beginning its long journey back to its feeding grounds. During their long journey the older, pregnant and sexually mature whales will typically travel first and furthest due to experience and excess body fat which allows them to deal with colder waters more effectively than younger whales. This amazing species can often be found living in deep offshore waters near the upper and lower northern/southern hemispheres in the Arctic and Antarctic regions during their feeding season (which takes places during the summer months). During this time the blue whale can be seen eating large amounts of various prey to prepare for their long migration trip towards the equator and into places such as the Channel Islands, Farallon Islands and Monterrey Bay where they go to mate and give birth. The summer is an ideal time for these marine mammals to stock up on food as their prey tends to migrate towards the northern/southern polar hemispheres during this time of year. As stated earlier the blue whale can often be found in the upper and lower northern/southern hemispheres during feeding season, however when mating season comes around these large marine mammals begin their migration towards the warmer tropical regions of the world such as the Golf of Mexico and Costa Rica. During mating season the blue whales will move to these warmer temperate waters to find a mating partner or bear offspring. They will then mate and rest in their new-found home for several months before migrating back towards the Arctic and Antarctic waters they live in during their feeding season. Although blue whales can be found living near the equator many of the blue whales will limit how close they come to the equator because they can become easily overheated due to their large size and thick layer of blubber. The average gestation period for the blue whale is around 10 – 12 months, which provides these marine mammals with enough time to mate and bear offspring in the same tropical climate. Social Structure and Communication Blue whales are solitary animals often traveling alone or in small groups. They communicate to one another by using loud low-pitched moans and whines which can be heard many miles away. During mating periods adult blue whales may be heard performing mating calls which are often referred to as a mating song as they look for other whales to mate with. These songs can often be heard over long distances and is even observable well below the surface of the water. Although the exact reason for these songs is unknown it is believed that it may play a role in helping the whales find a mating partner, locate other pod members and even express sorrow when a pod member is sick or dies. While these marine mammals tend to prefer smaller groups the blue whale can be found traveling in larger pods during periods of feeding, mating and migration. Reproduction and Lifespan Little is known about how blue whales reproduce. The average gestation period for a female blue whale usually lasts 10 – 12 months once the female becomes impregnated. At the end of the gestation term the female will give birth to a single offspring. The baby blue whale can measure in at 20 – 25 ft. long when born (1/4 – 1/3 the size of an adult blue whale). For the first 6 – 9 months the newborn will be fed milk from its mother nipple. The milk is full of fat and nutrients that will the child develop during its first months of life. After the child stops being nursed by its mother it will begin to start consuming solid foods and hunting for its own prey. Once the young whale matures around the ages of 5 – 10 years it can begin mating and reproducing on its own. As with other baleen whale species when the blue whale reaches adult hood the female whales typically grow to be larger than their male counterparts. While fertile the female blue whale may give birth every 2-3 years after giving birth to its previous child. In terms of lifespan it is estimated that a blue whale may live for up to 90 years. In the past during the whaling era the blue whale faced frequent threats from whalers and poachers looking to sell their oil so that it could be used to make various products. Excessive hunting eventually led to huge declines in the blue whale population. Eventually the act of commercial whaling begin outlawed making it illegal for companies and individuals to continue hunting them. Today the blue whale is a protected species and anyone caught killing them could face fines and jail time. While these marine mammals are relatively safe from human interaction they may still be hunted from time to time for their meat. Aside from occasionally being hunted the blue whale may also face threats from pollution, collisions with boats and ships, global warming and incidents with fishing gear and other aquatic equipment. As stated earlier these marine mammals do not have any known predators, however smaller less experienced blue whales may be occasionally attacked by a group of killer whales. For more information about the whaling era read: The history of whaling. 10 Interesting blue whale facts - Being able to grow to lengths of over 100 ft. long and weighing up to 180 tons the blue whale is the largest living animal in the world. - Although the blue whale is called a “blue” whale it is actually closer to a grayish blue rather than a solid blue. It isn’t until the whale dives under the water that it appears to be a solid blue color. - A baby blue whale can measure in at around 25 ft. long making it as big as a killer whale, which is the largest marine mammal in the dolphin species. - A healthy adult blue whale can live for 70 – 90 years. - The blue whale can eat as many as 40 million krill per day or around 8,000 lbs. daily in order to power its massive body. - These marine mammals aren’t known to have any natural predators, except for occasional attacks on smaller (usually) baby whales by a pack of killer whales, however these attacks appear to be quite rare. - When searching for food the blue whale can hold its breath for up to 35 minutes. - Depending on where the research has been gathered it is estimated that as much as 95% – 99% of the entire blue whale population was killed during the whaling era. - Due to significant hunting during the whaling era these marine mammals are now considered endangered and are listed as a protected species. - The blue whale belongs to one of around 80 known species is Cetacea, which includes all species of whale, dolphin and porpoise.
According to a study published in Developmental Psychobiology, companion animals, such as dogs, cats or guinea pigs, may be a good addition to treatment programs designed to help children with ASDs improve their social skills and interactions with other people. “Previous studies suggest that in the presence of companion animals, children with autism spectrum disorders function better socially,” said James Griffin, Ph.D., of the Child Development and Behavior Branch at Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “This study provides physiological evidence that the proximity of animals eases the stress that children with autism may experience in social situations.” For the new study, researchers measured skin conductance — the ease at which an unnoticeable electric charge passes through a patch of skin — in children with ASDs and in typically developing children. Researchers divided 114 children, ages five to 12 years old, into 38 groups of three. Each group included one child with ASD and two typically developing children. Each child wore a wrist band fitted with a device that measures skin conductance. When people are feeling excited, fearful, or anxious, the electric charge travels faster through the skin, providing an objective way to gauge social anxiety and other forms of psychological arousal, according to the researchers. For the first few minutes, the children read a book silently, giving researchers a baseline measure of skin conductance while carrying out a non-stressful, familiar task. Next, each child was asked to read aloud from the book, a task designed to measure their level of apprehension during social situations. The researchers then brought toys in the room and allowed the children 10 minutes of free play time. These situations may be stressful for children with ASDs, who may have difficulty relating socially to typically developing peers, the researchers note. Finally, the researchers brought two guinea pigs into the room and allowed the children to have 10 minutes of supervised play with the animals. The researchers said they chose guinea pigs because of their small size and docile nature. The researchers found that, compared to the typically developing children, the children with autism had higher skin conductance levels when reading silently, reading aloud, and in the group toy session. These higher levels are consistent with reports from parents and teachers, and from other studies, that children with ASDs are more likely to be anxious in social situations than typically developing children. When the session with the guinea pigs began, however, skin conductance levels among the children with ASDs dropped significantly, according to the study’s findings. The researchers speculate that because companion animals offer unqualified acceptance, their presence makes the children feel more secure. For reasons the researchers cannot explain, skin conductance levels in the typically developing children rose during the session with the guinea pigs. The researchers said they believe that these higher readings may indicate excitement at seeing the animals, rather than any nervousness or apprehension. Lead researcher Dr. Marguerite O’Haire, from the Center for the Human-Animal Bond in the College of Veterinary Medicine of Purdue University in Indiana, added that earlier studies have shown that children with ASDs were less likely to withdraw from social situations when companion animals are present. These studies, along with the new findings, indicate that animals might “play a part in interventions seeking to help children with autism develop their social skills,” she said. She cautioned, however, that the findings do not mean that parents of children with ASDs should rush to buy an animal for their children. Further research is needed to determine how animals might be used in programs aimed at developing social skills, she advised. “Our study was conducted in a supervised setting, by researchers experienced in working with kids with autism spectrum disorders who understand the needs and requirements of the animals,” O’Haire said, adding that careful supervision was provided during the study to ensure the welfare of the children, as well as the animals. Photo Credit: Marguerite O’Haire, Ph.D., from the Center for the Human-Animal Bond in the College of Veterinary Medicine of Purdue University in West Lafayette, Indiana.
According to National Geographic, a new research study shows that the magnetic North Pole is changing positions at a surprisingly quick pace, sliding towards Russia at a speed of about 40 miles per year. Traditionally, the Pole has been located in Northern Canada, but these rapid shifts are causing it to jump dramatically. Scientists believe that changes deep within the Earth’s molten core are to blame for the shift, although it is difficult to measure and track those changes. Researchers have detected a disturbance on the surface of the core that is creating a “magnetic plume” which is responsible for the change in the Pole’s location, but how that plume was created remains a mystery. The shifting of the magnetic pole is not quite as problematic as it once would have been. For centuries the North Pole has been used for navigational purposes, but for the most part, standard compasses have been replaced with sophisticated GPS tracking systems. Still, many explorers, mountaineers, backpackers, and the like still prefer using a compass over an electronic device. As the pole shifts position, they’ll need to learn to take into account its new location when plotting their course. At this point, scientists are unsure exactly how far the pole will move or if it will become a permanent shift in location. The mysterious plume could dissipate and cause the pole to return to its original position, not far from Canada’s Ellesmere Island, or it could continue to move for years to come.
American Sign Language Welcome to the American Sign Language wikibook. American Sign Language, or ASL is a visual language expressed through hand gestures and facial expressions. It is a language used by many Deaf, hearing-impaired and hearing people in North America. This wikibook aims to teach ASL vocabulary, grammar and exercises to beginners. Feel free to contribute! Table of Contents - Introduction: History of American Sign Language · Deaf Culture · Alphabet and Numbers - Location - Linguistics - Level 1: Fingerspelling 1 · Vocabulary 1 · Basic Grammar 1 · Simple Sentences 1 - Grammar 1 - Lesson 2: Fingerspelling 2 · Vocabulary 2 · Basic Grammar 2 · Facial Expressions 1 · Dialogue 1 - Lesson 3:
Lymphoma is a cancer of white blood cells called B-lymphocytes, or B-cells. They multiply rapidly and form tumors. Lymphoma of the brain or spinal cord is called central nervous system (CNS) lymphoma. AIDS-related lymphoma is sometimes called Non-Hodgkin’s Lymphoma (NHL). In 1985, the Centers for Disease Control added NHL to the list of diseases that define AIDS. Hodgkin’s Disease, another type of lymphoma, is rare in people with HIV. The longer you live with a suppressed immune system, the higher the risk of NHL. It can occur even with a high CD4 count. It can be serious and often fatal, sometimes within a year. The use of combination antiretroviral therapy (ART) cut the rates of most opportunistic infections by about 80%. At first, this did not appear to be true for NHL. However, newer studies show a decrease of about 50% in NHL rates, especially CNS lymphoma. NHL still accounts for about 20% of the deaths of people with HIV. Approximately 10% of people with HIV may eventually develop NHL. NHL tumors can occur in the bone, abdomen, liver, brain or other parts of the body. The first signs of NHL are swollen lymph nodes, fever, night sweats, and weight loss of more than 10%. These symptoms occur with several AIDS-related illnesses. If health care providers cannot find another cause for these symptoms, they will test for NHL. NHL is usually diagnosed using imaging techniques or biopsies. The imaging techniques include various scans (CAT, PET, gallium, and thallium). A biopsy is an examination of cells from a suspected tumor. The cells are collected by a thin needle, or they are cut out surgically. NHL is caused by long-term stimulation of the immune system. When B-cells multiply quickly for many years, more mutations occur. Some of these mutations cause cancer. About 4% of people with symptoms of HIV disease develop NHL each year. The rate of NHL in people with HIV is over 80 times higher than for the general population. A recent study found higher rates for people with a CD4 count that ever dropped below 200, and the longer they had a high or uncontrolled viral load. The risk of NHL is increased by infection with Epstein-Barr virus and by genetic factors. The rate of NHL is twice as high in men as in women, and twice as high in Caucasians as in people of African or Caribbean ancestry. At the present time we don’t know how to prevent NHL. Most cancers are treated by a combination of drugs (chemotherapy or chemo). Chemo is very toxic. It suppresses the immune system. It can cause nausea, vomiting, fatigue, diarrhea, swollen and sensitive gums, mouth sores, hair loss, and numbness or tingling in the feet or hands. Chemo also damages bone marrow. This can cause anemia (low red blood cells) and neutropenia (low white blood cells). Neutropenia increases the risk of bacterial infections. Additional drugs may be needed to fight these side effects. NHL in the central nervous system is very difficult to treat. Radiation therapy may be used instead of, or in addition to chemotherapy. ART makes it easier for HIV patients to tolerate strong chemotherapy for NHL. As a result, the death rate from NHL has dropped by over 80%. Seventy-four percent of patients recovered from NHL in a study using a newer combination of chemotherapy drugs known as EPOCH. Since people started using strong ART, the types of NHL seen in people with HIV are easier to treat. As a result, people with HIV and NHL are living longer. Several types of chemo are used for NHL. Chemo clears up tumors in about 50% of patients. However, tumors return in many patients within a year. People diagnosed with NHL are at a higher risk of developing pneumocystis pneumonia (PCP) and should take medications to prevent it. See Fact Sheet 515 for more information on PCP. “Monoclonal antibodies” are being used against NHL, and researchers continue to study their use. These drugs are produced through genetic engineering. They attack the B-cells that are multiplying out of control. The names of monoclonal antibodies end in “-mab,” such as rituximab. They shrink tumors and increase the time before tumors return. NHL, a cancer involving B-cells, affects people with advanced AIDS. It is serious and often fatal. The use of ART has reduced the number of new cases. This is especially true for NHL in the central nervous system (CNS). NHL is treated with chemotherapy drugs. In the CNS, radiation therapy is also used. Even if NHL tumors are cleared up, they tend to return in many people. Treatment of NHL is difficult. People who get it often have very weak immune systems. ART strengthens the immune system and permits the use of stronger chemotherapy. It also seems to make NHL easier to treat. Additional drugs are often needed to deal with the side effects of chemo. New genetically engineered drugs called monoclonal antibodies are now being used against NHL. Studies of the use of monoclonal antibodies and new combinations of chemo drugs are continuing.
About Human Rights Day The Universal Declaration of Human Rights (UDHR) was adopted on 10 December 1948. The date has since served to mark Human Rights Day worldwide. The High Commissioner for Human Rights, as the main UN rights official, and her Office play a major role in coordinating efforts for the yearly observance of Human Rights Day. The UDHR: the foremost statement of the rights and freedoms of all human beings The Declaration adopted by the United Nations General Assembly in 1948, consists of a preamble and 30 articles, setting out a broad range of fundamental human rights and freedoms to which all men and women, everywhere in the world, are entitled, without any distinction. The Declaration was drafted by representatives of all regions and legal traditions. It has over time been accepted as a contract between governments and their peoples. Virtually all states have accepted it. The Declaration has also served as the foundation for an expanding system of human rights protection that today focuses also on vulnerable groups such as disabled persons, indigenous peoples and migrant workers. The Most Universal Document in the World The Office of the High Commissioner for Human Rights has been awarded the Guinness World Record for having collected, translated and disseminated the Universal Declaration of Human Rights into more than 380 languages and dialects: from Abkhaz to Zulu. The Universal Declaration is thus the most translated document - indeed, the most "universal" one in the world.
Brain metastasis refers to the spread (metastasis) of cancer to the brain from another part of the body. Over the last few decades, the improved effectiveness of surgery, chemotherapy and radiotherapy has meant people now survive cancer for longer than ever before. In addition, more advanced diagnostic and screening methods mean cancer is often detected early, well before it has spread from its site of origin to other parts of the body. However, brain tumors still occur in patients months or years after they first received treatment. The prognosis of brain metastasis is poor and most patients with this condition eventually die. In many cases, patients do not experience any symptoms as a result of having cancer until it has spread to the brain. Once the cancer does involve the brain, symptoms may be wide ranging and examples include: - Nausea and vomiting - Loss of memory - Cognitive changes - Behavioral changes - Visual disturbances - Numbness and tingling of limbs - Balance problems - Bell’s palsy A study of 2,700 patients being treated for brain metastasis showed that common cancers from which the brain tumors originated included lung cancer, breast cancer, genitourinary cancer, osteosarcoma, melanoma, head and neck cancer, pancreatic cancer, neuroblastoma and lymphoma. The treatment of brain metastasis is usually focused on relieving symptoms and prolonging survival. In some cases, procedures such as open craniotomy, aggressive chemotherapy and radiosurgery may be attempted if a patient is young and fit. Some of the symptomatic therapies that may be administered include corticosteroids to prevent edema (swelling) in the brain and anti-epileptic drugs to prevent seizures. Radiotherapy may be given in the form of whole-brain irradiation, radiosurgery or fractionated radiotherapy. Surgery is often used to remove a single tumor or a limited number of tumors that are located close to each other. Reviewed by Sally Robertson, BSc
LA: Write informative/explanatory texts to examine a topic and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content. LA: Demonstrate command of the conventions of standard English capitalization, punctuation, and spelling when writing. LA: Engage effectively in a range of collaborative discussions with diverse partners on grade level topics, texts, and issues, building on others' ideas and expressing one's own clearly. SCI: Ask questions about the natural and human-built worlds. SS: Use appropriate resources, data sources, and geographic tools to generate, manipulate, and interpret information. VA: Use different media, techniques, and processes to communicate ideas, experiences, and stories. VA: Use visual structures of art to communicate ideas.
History of the Illinois Valley Our valley has a rich historic past which ranges from the Native Americans to miners and loggers to the pioneers, all of whom helped make our valley a great place to live today. About 10,000 years ago, the first Native Americans arrived in the valley and were called Takelma, or Dagelmas, which in their language means “they who live alongside the river.” The Takelmas lived off the land and built wooden plank or “pit” houses which consisted of a central fire pit. They gathered native plants, fished the local streams and hunted the game. Acorns from the local oak trees provided an important food source. Before the acorns could be used, they had to first be soaked in water to leach out the chemical called tannin. This tannin was later used in the tanning of hides. Prior to the discovery of gold in the valley in the early 1850s, the Takelmas lived a peaceful life. As more non-native people moved into the area in search of gold, conflicts broke out between miners and the Native Americans. Between 1855 and 1856, several pitched battles occurred which became known as the Rogue Indian Wars. Today, there are several historic markers in the valley that recall this conflict. Geologic History of the Valley: The valley’s rich geologic history goes back almost 200 million years when most of today’s land area started out as an ancient ocean bottom. Over time, this ocean bottom was pushed up and transformed into part of the Siskiyou Mountains. Today, the Siskiyou Mountains are only one of two mountain ranges that run west to east in the entire United States. Another indication of the geologic age of our valley is the Oregon Caves National Monument. About 180 million years ago, the caves started out as an ancient ocean reef. Over time this reef was pushed up (uplifted in geologic terms) and as it underwent immense pressure, the limestone was heated and changed into marble. Today, you can go on ranger-guided tours of the “Marble Halls of Oregon” and see a variety of limestone and marble formations. Gold, copper and other mining activities continued into the early part of the 1900s and today there are many active small mining claims which speak of the valley’s rich geologic heritage.
Predicting the Future Overview: Moore’s Law states that computer processor speed doubles every 18 months. Compare that to progress in the early 1900′s and your students can see how things are moving zillions of miles per hour faster than in the past. With the new millennium upon us, what better time to predict the future? Resources: Teacher: time line of inventions for the last 100 years. Student: pencil, paper. Teacher Preparation: none. 1. Review time line of inventions for this century. Older students can research this on their own. 2. Brainstorm ideas of what breakthroughs or inventions may happen by the year 2000. 3. Students may be assigned specific areas to focus on, such as medicine, transportation or communication to research in order to better predict what the next five years holds. This could be as simple as third graders reading through their science book index, or as involved as high school seniors doing a research paper with numerous bibliography entries. Variations/Options: As a resource, Wired Magazine highlights monthly a futuristic topic with predictions by experts for its implementation; research into predictions from 10 to 20 years ago on various topics to share with the class; make a time line of Internet-related events.
ASU researchers aim to pull fuels out of thin air Nonrenewable fossil fuels give liquid fuels a bad name. But not all liquid fuels are fossil fuels, and fuels don’t have to be dirty. Fuels are considered dirty when they put new carbon dioxide into the atmosphere, which causes pollution and the buildup of environmentally detrimental greenhouse gases. But what if rather than using fuels that add carbon dioxide, we could create fuels that recycle carbon dioxide from the atmosphere? Researchers at Arizona State University are exploring the idea of creating fuels that do just that: carbon-neutral liquid fuels. Think of them as fuels created out of thin air. The endeavor builds on the advances being made at ASU’s Center for Negative Carbon Emissions, which is developing a technology that collects carbon dioxide from the atmosphere using an air-capture technique that literally scrubs it from the air and then captures it so it can be reused at an affordable cost — a carbon dioxide recycling program. This effort moves toward closing the carbon cycle, which means making sure no new carbon dioxide ends up in the atmosphere — essential for ensuring that concentrations don’t surpass unsafe limits for life on Earth. In addition to the environmental benefits of removing carbon dioxide, excessive amounts of it can be turned into carbon-neutral liquid fuels, making it a renewable energy source. “The answer to our search for a sustainable future is likely to involve a combination of technologies — and fuels from air will play an important role.” — Arvind Ramachandran, ASU environmental engineering doctoral student How exactly can fuel be pulled from thin air? Like any magic act, it is surprisingly simple. First, the center's researchers generate hydrogen by using a renewable, carbon-free electricity source (such as wind energy or solar power) to split water through a process called electrolysis. Second, this gaseous hydrogen is combined with the carbon dioxide captured from air. What does this mixture produce? Methanol, an alcohol fuel similar to ethanol. Voila! Fuel from air. Like ethanol, methanol can be blended with gasoline or further processed into gasoline. “When this methanol or synthetic gasoline is burned, it releases carbon dioxide and water back into the atmosphere where it can then be recaptured and reused to make more fuel,” said Steve Atkins, a Center for Negative Carbon Emissions senior engineer who specializes in this technology. Methanol can also be converted into plastics that would be carbon negative, or into other fuels such as diesel and jet fuel. “If we can make air-capture affordable then we have a carbon-neutral feedstock to make liquid fuels and take advantage of abundant renewable energy,” said Christophe Jospe, who was CNCE’s chief strategist from September 2014 until June of this year and is now founding The Carbon A List to highlight the most promising approaches to capturing and recycling carbon dioxide. The big impacts of this technology are threefold. First, it can help society to go carbon neutral. Unlike fossil fuels, carbon-neutral liquid fuels do not add greenhouse gases or generate a net carbon footprint. Limiting, and preferably reducing, our carbon footprint is essential for sustaining life. Second, this technology is attractive because carbon-neutral liquid fuels can be used within our current industrial infrastructure. “If we can’t use the internal combustion engines in our cars, then we have wasted assets,” Jospe said. This renewable alternative can work within society’s current infrastructure and energy system and be more sustainable. Third, it addresses some of the limitations of other renewable energy methods. Solar and wind power experience intermittent drops in energy production. Much like traditional liquid fuels, carbon-neutral liquid fuels can be stored long-term and used in accordance with demand. “During periods of intermittency in renewable energy, you could utilize liquid, carbon-neutral synthetic fuels to provide electrical power,” said Atkins — though he acknowledges the round-trip efficiency (electricity to fuels and back to electricity) would be low. Related to our transportation fleet, Jospe said, “We don’t need to move toward a totally electrified transportation fleet. We can use fuels, but the fuels need to become carbon neutral.” Flying an airplane with an electric battery may not be a realistic option due to the reality of energy density (how much energy is contained within a unit). “Batteries can’t pack as much electrons into the same amount of space,” Jospe said. That means options like jet fuel are beneficial because they are lighter weight, and can power travel across further distances. Maybe it’s easiest to say that they offer users more bang for their buck. But nonrenewable fuels, like jet fuel, also come with nasty consequences for the environment. Promisingly, the energy density of carbon-neutral liquid fuels can be more advantageous than current batteries. They are also better than fossil fuels because they avoid adding new carbon to the atmosphere. Arvind Ramachandran, a first-year environmental engineering doctoral student, is advancing research in converting captured carbon dioxide into fuels and chemicals under the supervision of Klaus Lackner, the director of CNCE and a professor in ASU’s Ira A. Fulton Schools of Engineering. “I think it is very clear that we have to figure out a way to become carbon negative or at least carbon neutral,” said Ramachandran, who earned his master’s degree in chemical engineering from Columbia University. “Making sure that our mobile sources of carbon dioxide emissions, such as cars and airplanes, are running on carbon-neutral fuels represents a powerful way of achieving carbon neutrality,” he said. The U.S. Department of Energy’s ARPA-E REFUEL program (short for Advanced Research Projects Agency-Energy’s Renewable Energy to Fuels through Utilization of Energy-dense Liquids) is currently offering funding opportunities to encourage innovations in liquid fuel technology that promise significant impacts. Jospe thinks the air-capture technique fits the need by supporting the synthesis of fuels made from the air. CNCE is currently applying for ARPA-E funding to advance this effort. Getting fuels from air is not the only option researchers at ASU are exploring. Others are advancing the production of biofuels from algae as part of a multi-university project supported by a recently awarded $2 million grant from the Bioenergy Technologies Office in the U.S. Department of Energy. Additional niche applications of the air-capture technology would make it possible to use it to carbonate beverages, create high-value chemicals and sequester carbon in products such as graphene, plastics and carbon fiber. These and many other products and systems require the use of carbon dioxide. “Let’s get that carbon from air so we know it’s carbon neutral, rather than a source that doesn’t help us close the carbon cycle,” Jospe said. CNCE researchers will promote and build on these ideas further when ASU hosts the Fuels From Air Conference on Sept. 28-30. The conference will bring researchers from around the world to discuss closing the carbon cycle, techniques in taking fuels from air and different ways to turn carbon dioxide into fuels. Ramachandran, a budding specialist in this new and exciting field, said it best: “The answer to our search for a sustainable future is likely to involve a combination of technologies — and fuels from air will play an important role.”
HIV or Human Immunodeficiency Virus is a lentivirus, which is a sub-classification of the retrovirus. It causes the HIV infection which over time leads to AIDS or Acquired Immunodeficiency Syndrome. AIDS is a deadly condition in which the affected person’s immune system fails leading to the spread of life-threatening infections and cancers in his body. The average survival period for a person affected with HIV without treatment is nine to eleven years subject to the subtype of HIV. HIV infection can occur by the transference of blood, breast milk, vaginal fluid, semen or pre-ejaculate. HIV occurs as both free virus particles and as virus inside the infected immune cells within the above-mentioned bodily fluids.
Squash (plural squash or squashes) is the common name used for four species in the genus Cucurbita of the gourd family Cucurbitaceae: C. pepo, C. maxima, C. mixta, and C. moschata. These plants, which originated in the Americas, are tendril-bearing plants characterized by hairy stems, unisexual flowers, and a fleshy fruit with a leathery rind that is a type of false berry called a pepo. The name squash also is used for the edible fruit of any of these plants, which can vary considerably in shape, color, and size and is consumed as a vegetable. In North America, squash are loosely grouped into summer squash or winter squash, as well as autumn squash (another name is cheese squash) depending on whether they are harvested as immature fruits (summer squash) or mature fruits (autumn squash or winter squash). Gourds are from the same family as squash. Well known types of squash include the pumpkin and zucchini. Although originating in the Americas, squash are now grown in most countries. While squash tend to be quite nutritious, with high levels of vitamins A and C, niacin, riboflavin, and iron, their attraction to humans extends beyond this to more internal and aesthetic values. Their great variety in colors, color patterns, and shapes—from light green or white to deep yellow, orange, and dark green, from solid to striped, and from flattened to cylindrical to crookneck varieties—combined with their special aroma and taste, offers humans a unique visual and culinary experience. The four species of squash belong to the Cucurbitaceae, a flowering plant family commonly known as gourds or cucurbits and including crops like cucumbers, luffas, melons, and watermelons. The family is predominantly distributed around the tropics, where those with edible fruits were among the earliest cultivated plants in both the Old and New Worlds. The Cucurbitaceae is sometimes known as the gourd family and sometimes as the squash family. Most of the plants in this Cucurbitaceae family are annual vines, but there are also woody lianas, thorny shrubs, and trees (Dendrosicyos). Many species have large, yellow or white flowers. The stems are hairy and pentangular. Tendrils are present at 90 degrees to the leaf petioles at nodes. (In botany, a tendril is a specialized stem, leaf, or petiole with a threadlike shape that is used by climbing plants for support and attachment, generally by twining around whatever it touches.) Leaves are exstipulate, alternate, simple palmately lobed or palmately compound. The flowers are unisexual, with male and female flowers usually on different plants (dioecious), or less common on the same plant (monoecious). The female flowers have inferior ovaries. The fruit is often a kind of berry called a pepo. The pepo, derived from an inferior ovary, is characteristic of the Cucurbitaceae. Squashes generally refer to four species of the genus Cucurbita native to the New World, also called marrows depending on variety or the nationality of the speaker. Archaeological evidence suggests that squash may have been first cultivated in Mesoamerica some 8,000 to 10,000 years ago (Roush 1997; Smith 1997), but may have been independently cultivated elsewhere, albeit later (Smith 2006). Squash was one of the "Three Sisters" planted by Native Americans. The Three Sisters were the three main indigenous plants used for agriculture: Maize (corn), beans, and squash. These were usually planted together, with the cornstalk providing support for the climbing beans, and shade for the squash. The squash vines provided ground cover to limit weeds. The beans provided nitrogen fixing for all three crops. The English word "squash" derives from askutasquash (literally, "a green thing eaten raw"), a word from the Narragansett language. This was documented by Roger Williams, the founder of Rhode Island, in his 1643 publication A Key Into the Language of America. Similar words for squash exist in related languages of the Algonquian family such as Massachusett. The squash fruit is classified as a pepo by botanists, which is a special type of epigynous berry with a thick outer wall or rind formed from hypanthium tissue fused to the exocarp; the fleshy interior is composed of mesocarp and endocarp. (An epigynous berry, or false berry, is an accessory fruit found in certain plant species with an inferior ovary, distinguishing it from a true berry. In these species other parts of the flower can ripen along with the ovary, forming the false berry.) There is great variety in the size, shape, and color of squash fruit, with shapes including flattened and cylindrical forms, and squash with straight and crooked necks. Colors may be white, green, yellow, and with stripes or solid colors. Squash is commonly divided into two main categories: Summer squash and winter squash. This is not a biological classification, but rather division on the basis of when the vegetable is harvested—in other words, whether the squash is immature or mature. Both summer and winter squash can be of any of the four species. Summer squash is most commonly associated with C. pepo, but winter squash is common among all four species. Summer squash is the category that includes those squash harvested during the growing season, while the skin is still tender and the fruit relatively small. They have soft seeds and thin, edible skins, and tender flesh with a high water content (Herbst 2001). Summer squash is very perishable and may last only five days even when refrigerated in a plastic bag (Herbst 2001). They are consumed almost immediately after harvesting and require little or no cooking. Summer varieties include young vegetable marrows such as zucchini (also known as courgette), pattypan, and yellow crookneck). Winter squash is the category for those squash harvested at maturity, generally the end of summer, cured to further harden the skin, and stored in a cool place for eating later. Winter squash have thick and hard seeds and skin, and flesh that is firmer (Herbst 2001). Winter squash, protected by its hard skin, can be stored much longer and does not require refrigeration, lasting a month or more in a cool dark place depending on the variety (Herbst 2001). They generally require longer cooking time than summer squashes. Winter varieties include butternut, Hubbard, buttercup, ambercup, acorn, spaghetti squash, and pumpkin) (Note: Although the term "winter squash" is used here to differentiate from "summer squash," it is also commonly used as a synonym for Cucurbita maxima.) Four species of the genus Cucurbita are called squash or pumpkins rather indiscriminately. While squashes and pumpkins are notorious for producing hybrids when grown within pollinator range of each other; the different species do not naturally hybridize with each other. As with all other members of the family, the flowers come in pollen-bearing male form and the ovary-bearing female form, with both forms being present on the plant. Squash has historically been pollinated by the native North American squash bee Peponapis pruinosa, and related species. However, this bee and its relatives have declined, probably due to pesticide sensitivity, and most commercial plantings are pollinated by European honey bees today. One hive per acre (4,000 m² per hive) is recommended by the United States Department of Agriculture. Gardeners with a shortage of bees often have to hand pollinate. Inadequately pollinated female squash flowers will usually start growing but abort before full development. Many gardeners blame various fungal diseases for the aborted fruit, but the fix proves to be better pollination, not fungicide. Nutritional value per 100 g \|Energy 20 kcal 70 kJ\| \|Percentages are relative to US recommendations for adults. Summer squash are high in vitamin A, vitamin C, and niacin and winter squash are a good source of iron, riboflavin, vitamin A, and vitamin C (Herbst 2001). Summer squash are commonly prepared by steaming, baking, deep-frying, and sautéing, and winter squash is commonly prepared by removing the seeds and baking, steaming, or simmering them (Herbst 2001). In addition to the fruit, other parts of the plant are edible. Squash seeds can be eaten directly, ground into paste, or (particularly for pumpkins) pressed for vegetable oil. The shoots, leaves, and tendrils can be eaten as greens. The blossoms are an important part of Native American cooking and are also used in many other parts of the world. The squash has been an essential crop in the Andes since the pre-Columbian era. The Moche culture from Northern Peru made ceramics from earth, water, and fire. This pottery was a sacred substance, formed in significant shapes and used to represent important themes. Squash are represented frequently in Moche ceramics (Berrin and Larco 1997). 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: Note: Some restrictions may apply to use of individual images which are separately licensed.
If your teeth seem especially sensitive after you brush them or when you consume certain foods or beverages, you're hardly alone: By one estimate, around 35 percent of the U.S. population experiences some degree of tooth sensitivity. While the difference between sensitivity and pain may be somewhat blurry, we can say that sensitive teeth usually produce discomfort in response to a stimulus like temperature, pressure, or even the sweetness of particular foods. What causes tooth sensitivity — and what should you do about it? In general, tooth sensitivity results when dentin, the living tissue that makes up most of the “body” of the tooth, begins transmitting sensations to nerves deep in the tooth's inner core. The nerves relay these sensations to the brain, and they're felt as pain. To understand how this works, let's take an even closer look at your teeth. Tooth Anatomy 101 Dentin is a sturdy, calcified tissue, that can't usually be seen. It's normally covered by super-hard enamel on the visible part of the tooth (the crown), and by softer tissue called cementum on the tooth's roots (which typically lie below the gum line). The dentin itself is composed of many tiny tubules. When these tubules become exposed to the environment of the mouth, tooth sensitivity and pain may result. There are several reasons why the dentin can become exposed. For one, the gums may recede (shrink down), revealing some of the tooth's root surfaces. This can be caused by genetic factors, periodontal disease, excessively vigorous brushing — or a combination of all three. This problem may be worsened if the tooth's roots weren't completely covered by cementum during their development, as sometimes occurs. Another factor that may contribute to sensitivity is the erosion of tooth surfaces due to excessive acid in the diet. While acids occur naturally in the mouth, habitually drinking sodas and sports drinks can severely erode teeth — and brushing soon after you drink actually worsens the effect. That's because these acids soften the outer surfaces of the teeth, and brushing then makes it easy to wear them away. It's best to wait for an hour afterwards, to give your saliva a chance to neutralize the acid. Tooth decay can also cause sensitivity. Decay may not only expose dentin, but can work its way down to the nerves themselves — at which point, your pain level may escalate. And sometimes, even dental work itself can cause sensitivity. Because the same tooth structures are involved, it may sometimes take a few days after a cavity is filled, for example, for a tooth to “calm down.” Dealing With Tooth Sensitivity What can you do about sensitive teeth? If it's a relatively minor irritation, try not to brush the affected teeth too long or hard. Make sure you're using a soft-bristled brush and the proper, gentle brushing technique. Always use a toothpaste containing fluoride, as this ingredient is proven to increase the strength of tooth enamel, which helps resist erosion. You can also try a toothpaste with ingredients designed especially for sensitive teeth, such as potassium. Studies show that these can be effective… but it may take approximately 4 – 6 weeks for you to notice the difference. If sensitivity persists, however — or if your tooth pain becomes more intense — don't wait to get an examination to determine what's causing the problem. Once diagnosed, the most appropriate way to reduce the sensitivity will be recommended. Some treatments may include concentrated fluoride varnishes, prescription mouthrinses, or materials that are bonded to the outer surfaces of teeth. But tooth sensitivity may also be an early warning sign of other dental problems — and the sooner they're taken care of, the better off you'll be! Treatment of Tooth Sensitivity As many as 35% of the U.S. population suffers from tooth sensitivity. Causes include overly aggressive brushing, which causes the gum tissue to recede exposing the root surfaces of the teeth; and acidic beverages, which erode the teeth. Fortunately, there are products available for use at home or in the dental office that can help... Read Article Sensitive Teeth Tooth sensitivity — to hot or cold, for example — is often a problem where the gums have receded, exposing the root surfaces of the teeth. These areas of the teeth have sensitive nerve fibers. Find out what steps you can take to minimize this problem... Read Article A Severe Toothache You may think a painful toothache that goes away on its own is no longer cause for concern. However, it's still worth a visit to the dentist. The disappearance of pain could mean that the nerve tissue deep inside the tooth has died, yet an infection is still present... Read Article
Gigantic asteroids have smashed into the Earth before—RIP dinosaurs—and if we’re not watching out for all those errant space rocks, they could crash into our world again, with devastating consequences. That’s why Ed Lu and Danica Remy of the Asteroid Institute started a new project to track as many of them as possible. Lu, a former NASA astronaut and executive director of the institute, led a team that developed a novel algorithm called THOR, which harnesses massive computing power to compare points of light seen in different images of the night sky, then matches them to piece together an individual asteroid’s path through the solar system. They’ve already discovered 104 asteroids with the system, according to an announcement they released on Tuesday. While NASA, the European Space Agency, and other organizations have their own ongoing asteroid searches, all of them face the challenge of parsing telescope images with thousands or even 100,000 asteroids in them. Some of those telescopes don’t or can’t take multiple images of the same region on the same night, which makes it hard to tell if the same asteroid is appearing in multiple photos taken at different times. But THOR can make the connection between them. “What’s magical about THOR is, it realizes that out of all those asteroids, this one in a certain image, and this one in another image four nights later, and this one seven nights later are all the same object and can be put together as the trajectory of a real asteroid,” Lu says. This makes it possible to track the object’s path as it moves, and to determine if it’s on a trajectory bound for Earth. Such a formidable task wouldn’t have been possible with older, slower computers, he adds. “This is showing the importance of computation in going forward in astronomy. What's driving this is that computation is becoming so powerful and so cheap and ubiquitous.” Astronomers typically spy asteroids with something called a “tracklet,” a vector measured from multiple images, typically taken within an hour. These often involve an observing pattern with six or more images, which researchers can use to reconstruct the asteroid’s route. But if the data is incomplete—say, because a cloudy night obstructs the telescope’s view—then that asteroid will remain unconfirmed, or at least untrackable. But that’s where THOR, which stands for Tracklet-less Heliocentric Orbit Recovery, comes in, making it possible to ascertain the path of an asteroid that would have otherwise been missed. While NASA benefits from telescopes and surveys dedicated to spotting potentially hazardous asteroids, other data sets abound. And THOR can use almost any of them. “THOR makes any astronomical data set a data set where you can search for asteroids. That’s one of the coolest things about the algorithm,” says Joachim Moeyens, cocreator of THOR, and an Asteroid Institute fellow and graduate student at the University of Washington. For this initial demonstration, Moeyens, Lu, and their colleagues searched billions of images taken between 2012 and 2019 from telescopes managed by the National Optical Astronomy Observatory, many by a sensitive camera mounted on the Blanco 4-meter telescope in the Chilean Andes.
Conduction of excitation (GB#113H01) \| 基礎医学教育研究会(KIKKEN)Lab ● Electricity is running in the human body As you are experiencing on a daily basis, electric signals are fast anyway. If you try to convey information quickly among the body, it is best to use electrical signals as well. In nerve and muscle fibers, cells are in the shape of long strings (fibrous) like electric wires, and they use electricity to convey signals to the fibers. However, in reality, the electricity flowing through the cellular material does not reach far in the distance. In the electric appliances around us, electricity is flowing at once by using a copper wire while applying voltage, but another means is required in the body. That is the job of action potential conduction. - 1 ● Does electricity not travel far in the body? - 2 ● Conduction of excitation is a message game - 3 ● Running cell excitation does not turn back - 4 ● Excitation is transmitted quickly when suppressing leakage of ions - 5 ● Conduction is faster as the fiber becomes thicker - 6 ● What is the conduction speed of big animals? - 7 ○ Referenced sites - 8 ○ Related articles - 9 ○ Referenced books ● Does electricity not travel far in the body? Copper atoms are fixed in the copper wire, only electrons move over it. The number of copper atoms making up the entire copper wire is fixed, and the number of electrons carried by atoms is also fixed. So if you push in some electrons from the edge of the copper wire, the same number of electrons are driven out from the other side. It is not necessary to wait until the electron itself actually entered is moved to the other side. The signal travels far and farther. On the other hand, in the body, you can not make signal lines compacted with metal atoms like copper wire. It seems that ions with electricity are swimming underwater. Besides, ions in water do not easily exchange electrons.So when an electric signal occurs in a certain place, atoms (ions) with electricity move rather than electrons. But, the ions are much heavier than the electrons and they are big, so they collide with them. Moreover, it got leaked to the side on the way, and the electricity is not transmitted to places far away even if it is several millimeters. When the voltage is made much higher, the ions are forcibly blown and the electricity flows. However, without any meaning, electricity flows only, it can not be used for signals. That is the state of electric shock. ● Conduction of excitation is a message game Nerve and muscle fibers want to convey signals far away as surely as possible. However, the electric signal of the request is not transmitted at a stretch to far. So, what to do is to partially utilize the nature of the electricity transmitted immediately, and send a signal far away using chain reaction. In these cells, an ion channel that opens and closes in response to electricity is embedded in the entire cell membrane, and its opening and closing is transmitted in a chain reaction. The first action potential is generated at a place of the cell. The occurrence of action potential is called cell excitation. When the cell is excited, a voltage-dependent sodium channel opens and cationic sodium ions flow from outside the cell across the cell membrane. The inside of the cell membrane is originally in a state of negative electricity called resting potential. It is excited when the membrane potential causes depolarization to a certain extent. The incoming sodium ion becomes an electrical signal and depolarizes to the surroundings, but its effect does not reach the end of the fibrous cell as written above. But that’s enough. Open the reaching range sodium channel and generate a new action potential, then generate an action potential there from and next to it. As such, an open ion channel depolarizes around it to generate an action potential, a new action potential opens its surrounding channels, and the open channel also depolarizes around it. And repeated chain reactions are being transmitted. Ultimately, when the action potential arrives at the destination, the calcium channel opens additionally, and the increased calcium ion in the cell starts the next work. Excitement conduction is like a messaging game played in a line along a cellular fiber. Here, the voice is an electric signal, and a human corresponds to a channel. ● Running cell excitation does not turn back When cell excitation occurs, sodium ion flows into the cell, and positive electricity increases in the cell in that part. This depolarizes the surroundings and generates an action potential there, but then the action potential will occur only in places that are not excited just before. In the area just excited, even if depolarization occurs immediately afterwards, action potential does not occur. This is because the ion channel reacting with depolarization has the property that once it is opened, it does not open even when stimulated for a while. In action potential, it does not react for a certain period behind it. This is called the refractory period. Since there is a refractory period, excitation conduction will only proceed forward if it starts once. In the message game, this message game is slightly different, and the person who heard the message does not sneak out by placing his hand on the ear of the next person. The person who speaks is to repeat what you heard, so that both neighbors can hear it at the same time, but with no more audible voice. However, once a person speaks out, his voice can not be output for a while. In the meantime, even if the person can hear the voice of the neighbor, that person can not make it out. That’s why the message goes only in a certain direction. This method does not have to worry about which direction the message is conveyed. The person who heard it just repeats what he could hear. Excitement conduction is similar as well, and ion channels do not mind which excitement came from. So, in principle excitement can start with either fiber, which can go to either. This is said in the textbook “the nature of bi-directional conduction of excitement.” Actually, afferent nerve, efferent nerve and so on, the direction in which the signal travels with each fiber is decided in the body, so it might be a slightly confusing term. After the refractory period, the membrane returns to its original state. Excitement does not leave a trace on the membrane. Therefore, excitation conduction can be repeated any number of times, thousands of times and tens of thousands of times. (Although the actual repetitive message game gets tired soon ….) ● Excitation is transmitted quickly when suppressing leakage of ions The reason why the electrical signal of the action potential does not reach far is that ions are leaked little by little in the middle of the cell membrane. So if you suppress that leakage, the flow of ions will go far and conduction will proceed faster. In a message game, if you put a pipe that allows easy voice to pass between yourself and the members of both neighbors, you can spread the distance to which the same number of messages are told, so that the speed of the message doubles as a result. For nerve fibers, there is a method of covering the axon with a pipe that stops the leakage of ions, thereby increasing the conducting distance. Actually, around the axon, another cell makes a structure called myelin sheath, which spreads only the cell membrane and is wound tightly and many times. This nerve fiber is called myelinated nerve fiber. The excitatory conduction of myelinated nerve fibers is many times faster than that of unmyelinated nerve fiber. However, when there is a myelin sheath, the fiber becomes many times thicker, and the number of fibers packed in a limited space decreases, so that myelinated fibers and unmyelinated fibers are properly used depending on the application there. Then, when wrapped in myelin sheath, the leakage of ions disappears and conduction proceeds fast, but the ions traveling in the axons and outside the fibers are stagnated due to various obstacles this time. So at an interval of absolute safety, there is a gap called “node of Ranvier” in myelin sheath. In myelinated nerve fibers, the action potential is generated only at this node and excitation is transmitted, so this way of transmission is called saltatory conduction. There is a “demyelinating disease” in which the myelin sheath of myelinated nerve fibers is morbidly dropped out. It is easy to imagine that the conduction velocity slows down as the myelin sheath falls out and becomes an unmyelinated nerve. However, physiologically speaking, since there is no voltage-dependent sodium channel originally under the myelin sheath, the axon that lost myelination afterward should be quite different from the original unmyelinated nerve fiber. Depending on the extent of demyelination, if several blocks of myelin sheath are completely dropped, strong ion flow can not be expected to activate ion channels in the demyelinated tip. It seems reasonable to think that excitement conduction stops halfway. The incompletely damaged portion of the myelin sheath conducts incompletely, so the speed may be slow. In addition, it seems that each myelination sheath is long, the fiber with fast conduction speed is more affected by demyelination, and as a nerve fiber bundle, the conduction velocity is slowed as a whole. I think that the main symptom of demyelinating disease is “paralysis”, not sensory delay or movement delay. (Addenda) The influence on conduction due to dropping of myelin sheath seems to change with temperature. If the temperature is high, the movement of ions and channels is fast, the conduction is not easily excited and the conduction tends to be oblique, and if the temperature is low it is possible to get excited somehow, but it tends to become excitation conduction with a slow speed. Indeed, in “multiple sclerosis”, a representative of demyelinating diseases, it is known that the neurological symptoms of paralysis worsen as body temperature increases. ● Conduction is faster as the fiber becomes thicker “Excitement conduction is faster as the fiber is thicker” is a super fundamental subject which certainly comes out to the test. When the fiber becomes thick, when the cross section is seen, the length of the cell membrane becomes longer, but the cross sectional area of the fiber becomes wider by the square thereof. That’s why it is easier for ions to move in the axon, so it’s easier for electric signals to travel far. So, in fact, how much conduction speed? If you open a nearby textbook, the table of nerve fiber thickness and conduction velocity is almost always listed. As the representative one, the fastest fiber in the body is the motor nerve fiber that moves the skeletal muscle, and the sensory nerve fiber that checks the change in the length of the muscle, it is roughly around 100 m/s. In normal human the fastest peak is roughly 60 m/s when measured with the hands and feet. Both fibers eventually involve skeletal muscle movement, and of course, become myelinated nerve fibers. Because the maximum running speed of human being is about 10 m / sec, its 10 times that, for Olympic-class players, it may be an element that decides the limit of movement soon. In the late one, unmyelinated fibers per 30 cm/s will be on the table. This is assigned to autonomic nerves which may take some time, and dull pain nerve fibers which deliberately delivers over time. Usually, it is not described in the textbook, but the conduction speed of skeletal muscle fibers (not nerve fibers) seems to be about 3 to 4 m/sec. ● What is the conduction speed of big animals? By the way, these examples in textbooks are basically data on cats and humans. Roughly speaking, assuming that it is up to 100 m/sec, it is 0.02 sec when the signal is transmitted from the head to the foot when it is almost 2 m in human. This is almost no noticeable conduction time, so there is no problem, but it is 0.3 seconds if it is blue whale with a length of 30 meters. Well, in fact, whale movements are quite slow, so it might be such a thing. However, since conduction velocity of pain fibers is less than half of that of exercise system fibers in humans, if it is so for whales, conduction time seems to be about 0.6 seconds, is it so? There are more worrisome things about the nerve fibers of big animals. It is a nerve that is also present in humans, but in the branch of the vagus nerve that comes out from the medulla oblongata, there is a peripheral nerve called “recurrent laryngeal nerve”. It dominates the muscles of the throat, swallowing, speaking out. It somehow comes under the aortic arch, just above the heart. It is uselessly wrapping around, and in the case of humans this detour is not so bothersome. But how about the giraffe? When this nerve comes around the heart all the way from the brain, its length is about 12 m. Then, even though giraffe realizes it by swallowing strange things, the muscles of the throat can not react until about 0.2 seconds or less. That’s tough. Anxious such as something on the site below. (However, the main point of the article is that such evil things can not be done if there really is God, so evolution is not a proverb of God ….) In addition, it is written about how the head chief dragon which exceeded 10 m even with the neck alone. ○ Referenced sites ○ Related articles ◆ Action potential ◆ Voltage-dependent sodium channel ◆ Resting membrane potential ◆ シナプス伝達 neural signal transmission ◆ Cation and anion, attraction and repulsion ◆ Lipid bilayer of the cell membrane ◆ 心筋線維 myocardial fiber ◆ Stretch reflex ◆ 対光反射 pupillary light reflex ◆ A neural circuit for voluntary movement ○ Referenced books ・細胞の分子生物学，ニュートンプレス; 第5版 (2010/01) ・肉単―ギリシャ語・ラテン語 (語源から覚える解剖学英単語集 (筋肉編)) ・カラー図解人体の正常構造と機能全10巻縮刷版，坂井建雄，日本医事新報社 rev.20140611, rev.20140912，rev.20170505，rev.20170516, rev.20180407.KISO-IGAKU-KYOIKU-KENKYUKAI(KIKKEN)
COVID 19 – Update What is COVID-19? The COVID-19 is a corona virus disease that is caused by Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-COV-2). First discovered in Wuhan, China in 2019 (December) it is a beta Corona virus in the same subgenus as the SARS virus but in different clade. The structure of the receptor binding gene region is very similar to that of the south coronavirus, and a virus has been shown to use the same receptor, the angiotensin converting enzyme 2 (ACE 2) for cell entry. Till March 28 more than 600,000 cases of COVID-19 has been reported. The first case of COVID-19 from Wuhan was reported at the end of year 2019. The primary mode of spread is through droplets of saliva or nasal secretions when an infected person coughs or sneezes on an unsuspecting bystander. The person to person spread of COVID-19 is thought to occur mainly by respiratory droplets resembling the spread of influenza. Infection can also occur if a person touches an infected surface and then touches his or her face, eyes or nose. Droplets don’t travel more than 6 feet and do not linger in air for long. The incubation period is variable and the disease can occur within 14 days following exposure, although most cases occur approximately 4 to 5 days after exposure. Most infections are mild 81%, severe disease occurs in 14% and critical disease occurs in about 5% of the cases. The case fatality rate is about 2.3%. The risk factors for the severe illness includes following: 1. Cardiovascular disease. 2. Diabetes mellitus. 4. Chronic lung disease. 6. Chronic kidney disease. Individuals of any age can acquire the severe illness although the Middle Ages or elderly are more prone.
Bleeding into the skinEcchymoses; Skin spots - red; Pinpoint red spots on the skin; Petechiae; Purpura Bleeding into the skin can occur from broken blood vessels that form tiny red dots (called petechiae). Blood also can collect under the tissue in larger flat areas (called purpura), or in a very large bruised area (called an ecchymosis). Purpura is purple-colored spots and patches that occur on the skin, and in mucus membranes, including the lining of the mouth.Read Article Now Book Mark Article Aside from the common bruise, bleeding into the skin or mucous membranes is a very significant sign and should always be checked out by a health care provider. Redness of the skin (erythema) should not be mistaken for bleeding. Areas of bleeding under the skin do not become paler (blanch) when you press on the area, like the redness from erythema does. Many things can cause bleeding under the skin. Some of them are: - Injury or trauma - Allergic reaction - Autoimmune disorders - Viral infection or illness affecting blood clotting (coagulation) - Medical treatment, including radiation and chemotherapy - Antiplatelet medicines such as clopidogrel (Plavix) - Bruise (ecchymosis) - Birth (petechiae in the newborn) - Aging skin (ecchymosis) - Idiopathic thrombocytopenic purpura (petechiae and purpura) - Henoch-Schonlein purpura (purpura) - Leukemia (purpura and ecchymosis) - Medicines -- Anticoagulants such as warfarin or heparin (ecchymosis), aspirin (ecchymosis), steroids (ecchymosis) - Septicemia (petechiae, purpura, ecchymosis) Protect aging skin. Avoid trauma such as bumping or pulling on skin areas. For a cut or scrape, use direct pressure to stop the bleeding. If you have a drug reaction, ask your provider about stopping the drug. Otherwise, follow your prescribed therapy to treat the underlying cause of the problem. When to Contact a Medical Professional Contact your provider if: - You have sudden bleeding into the skin for no apparent reason - You notice unexplained bruising that does not go away What to Expect at Your Office Visit Your provider will examine you and ask questions about the bleeding, such as: - Have you recently had an injury or accident? - Have you been ill lately? - Have you had radiation therapy or chemotherapy? - What other medical treatments have you had? - Do you take aspirin more than once a week? - Do you take Coumadin, heparin, or other "blood thinners" (anticoagulants)? - Has the bleeding occurred repeatedly? - Have you always had a tendency to bleed into the skin? - Did the bleeding start in infancy (for example, with circumcision)? - Did it start with surgery or when you had a tooth pulled? The following diagnostic tests may be performed: - Coagulation tests including INR and prothrombin time - Complete blood count (CBC) with platelet count and blood differential Complete blood count (CBC) A complete blood count (CBC) test measures the following:The number of red blood cells (RBC count)The number of white blood cells (WBC count)The tota...Read Article Now Book Mark Article A platelet count is a lab test to measure how many platelets you have in your blood. Platelets are parts of the blood that help the blood clot. The...Read Article Now Book Mark Article - Bone marrow biopsy Hayward CPM. Clinical approach to the patient with bleeding or bruising. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 128. Juliano JJ, Cohen MS, Weber DJ. The acutely ill patient with fever and rash. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 57. Schafer AI. Approach to the patient with bleeding and thrombosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 162. Black eye - illustration A black eye is caused by bleeding into the tissue around the eye. This most often follows trauma. The medical term for this type of bruising is ecchymosis. Review Date: 5/3/2021 Reviewed By: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Researchers have found that the microbiome in the respiratory tract contributes to how susceptible we each are to the flu. Work is underway to use this data to create a preventive tool Researchers have been making strides on harnessing the body’s own immune system to fight a variety of diseases. Now, researchers at the University of Michigan believe they can use the microbiome of the respiratory system to create a preventive treatment for influenza. While vaccines are effective in protecting against some strains of the flu, not everyone is compliant with getting a flu shot, so the University of Michigan research team set out to find a cost-effective and easy way to reduce influenza risk. The flu virus targets cells in the upper and lower respiratory tracts-an area of the body already laden with bacteria from our own microbiome. Now a study, published in PLOS One, reveals that flu risk varies based on the composition of an individual’s own bacterial colonization. Previous studies have demonstrated changes in the microbiome in the nose and throat after infection of the flu virus, but there has been no association to date between the human nose/throat microbiome and influenza risk specifically. To study this further, the research team used data from the Nicaraguan Household Transmission Study, where healthy individuals living in a household with someone infected with flu were tracked for 13 days or until they developed the flu themselves. The study involved a total of 537 individuals, and samples were taken of the bacteria in their nose and throat at the onset of the study. The bacteria found in the microbiome of these individuals was studied and categorized into five clusters, and found that certain cluster groups were at lower risk for contracting the flu. This discovery, the research team notes, may explain why some individuals are naturally more susceptible to flu that others. Translating this discovery into an intervention is the next step, but there is a long road ahead. The research team hopes to use the data collected in this study can be used to find possible clinical and public health applications, perhaps in the form of a preventive treatment-like a probiotic-that would tailor an individual’s bacterial response to certain viruses. Betsy Foxman, PhD, professor of epidemiology and director of the Center for Molecular and Clinical Epidemiology of Infectious Diseases at the University of Michigan, co-authored the study. She said that while clinical applications of this research are not yet clear, it does confirm that the bacterial composition of the respiratory tract does play a role in determining the risk of acquiring influenza. “In the future, we may be able manage the nose/throat microbiome to help prevent acquiring influenza and other respiratory viruses and decrease risk of associated secondary bacterial infections-particularly otitis media and pneumonia,” Foxman said. “This would help preserve antibiotics, slowing the emergence of antibiotic resistance.” Foxman said the research team will continue to study the respiratory microbiome to determine if there are specific compositions that are particularly effective in preventing the risk of acquiring certain influenza types.
Crystallin is a transparent protein that makes up the lens of the human eye. This protein is water-soluble in structure, and has also been found in other parts of the body, such as the heart, and in some cancerous tumours. Crystallins make up 90% of water-soluble proteins in the lens of the eye. There are three classifications of Crystallins in science: alpha, beta and gamma. Beta and gamma crystallins are similar in structure, and have been grouped under the name βγ-Crystallins. The alpha Crystallins are named α-crystallins; and together, these two “families” of Crystallins make up 90% of proteins in the eye lens, and 30% of proteins in the entire eye. Research into crystallin is still ongoing; there have been significant breakthroughs in the last decade, particularly in determining the structure of Crystallin. In early 2020, researchers at the University of Munich determined the structure of Crystallin for the first time - the result of 40 years’ research. This allowed scientists to study any further uses of Crystallin, beyond what they already understood - and these findings helped to progress cataract treatment. Primarily, Crystallin’s function is to give the eye refractive power. This means that the eye is able to take in and refract light, without obstructing it - hence the transparent structure of the protein. In essence, Crystallin is the protein that allows humans to see light in such a detailed way, as well as having metabolic and regulatory function too, scientists believe.
Feeding your eyes is the most important thing you can do to ensure good vision. The foods you eat contribute directly and indirectly to your continuing eye health, or they can contribute to declining vision, eye disease, perhaps even blindness. A diet rich in fruits and vegetables, herbs, spices and fish contributes directly by supplying certain vitamins, carotenoids, minerals and essential fatty acids to your eyes. A diet loaded with saturated fats and sugar lacks many of the antioxidants necessary for eye health, which will lead to a buildup of free radicals. It also offers or creates substances that put your eyes at risk, such as arterial plaque, which leads to restricted blood flow through the blood vessels of the eyes. Foods also contribute indirectly to eye health by doing such things as supplying substances that regulate your blood sugar, high levels of which are directly implicated in diabetes-related eye diseases and can increase your risk of developing glaucoma. These foods are good for maintaining good eyesight. Weakened eyesight may be the result of improper nutrition and lack of the relevant nutrients that are related to the maintenance of the various eye components. • Carrots. These are rich in Vitamin A. Beta-carotene which is a precursor of Vitamin A plays an important role in numerous biochemical reactions in the body. The benefits of Vitamin A / Beta-carotene include maintenance of the surface linings in the eyes, and intestinal, urinary and respiratory tracts. • Cold water fish. These include sardines, mackerel, cod and tuna. These fish are a rich source of omega-3 fatty acids, and particularly DHA which plays a crucial role in the structure of cell-membranes. It is recommended for people with dry eyes and for the preservation of sight in general. • The leafy greens. These include spinach and kale. These are rich in carotenoids, with lutein of particular interest. This is a pigment that protects the macula (part of the eye deep in the centre of the retina) from damage via sunlight. • Eggs. They are rich in sulfur, cysteine, lecithin and again, lutein. They can protect from cataract formation. • Garlics and onions. These are also rich in sulfur, which is required for the synthesis of glutathione which is an antioxidant for the whole body, including the eye lens. It protects the body from damage and deterioration and this applies to the eyes as well. • Fruits and vegetables. They contain a lot of Vitamin C, Vitamin A, Vitamin E and Beta-carotene. Carrots are good for daytime vision. • Blueberries and grapes. They contain anthocyanins which are good for night vision. • Nuts and seeds. these contain zinc which is important for retina function. Zinc is also required to release Vitamin A from the liver which is then used by the eye. • Apricots (dried) Herbs and Spices Share this article
Soil salinity is caused by several factors. Soils may become saline as a result of land use, including the use of irrigation water with high levels of salt. Seawater is also a source of salts in low-lying areas along the coast through tidal estuaries or when rainfall in coastal regions mixes with sea spray. Saltwater intrusion into freshwater aquifers may occur when wells are close to the coast and water is pumped to the surface for various purposes, including irrigation. Irrigating from salt-impacted wells or saline industrial water may lead to the formation of saline soils. Soil sodicity, on the other hand, is caused by high sodium levels in soils at concentrations greater than 15 percent of the cation exchange capacity. Sodic soils tend to have poor structure with unfavorable physical properties such as poor water infiltration and air exchange, which can reduce plant growth.
In our day-to-day life people ‘manage’ many tasks. So, it is important to understand the meaning of the word Management. In simple words, Management means ‘To Manage’. To define it formally: It is the function that coordinates the efforts of individuals to accomplish an objective using available resources efficiently and effectively. The key processes of management are: Planning, Organising, Staffing, Directing and Controlling. All these steps are related and interdependent to each other. Every organisation has to follow a set of processes. If they are followed sequentially, the organisations get to know how to plan and organise their staff and how to direct them to attain the personal and organisational goals. It also helps them in dealing with predictability scenarios or unforeseen situations. By working together, the organisation builds Trust in their employees and on themselves in return, to deal with complex situations. If relationships are healthy, the work environment becomes favourable and people start working more dedicatedly, efficiently and effectively. If organisation cares for its employees and maintains its relationship in their good and hard times, the employees get further motivated and they try to give their best at work. This results to help the organisation to successfully compete in this competitive world of technology and helps to sustain their position in the markets. Understanding Organisation, Prediction& Trust The main areas of trust are: - Integration of speech and action - Respect and emotional bonding - Active communication
Since the ancient times, people have harnessed the kinetic energy created by the flow of wind to generate heat, mechanical energy and electricity. Wind Energy in History The earliest known windmills were in Iran (then Persia) where people constructed what looked like large paddle wheels that rotated with the wind to grind food grain. Similar designs of windmills became popular along the coast of the Mediterranean as well. Many years later, the Dutch improved this basic windmill to make it more efficient. They made its fins with sail cloth, which being light, caught even the slightest movement of wind. Holland is still famous for its picturesque windmills. Later, American colonists used windmills extensively. They ground wheat and corn, pumped water, and sawed logs -- all with the aid of windmills. Rural areas far from power lines used windmills to generate electricity as late as the 1920s. But soon, power generated by fossil fuel combustion became so cheap and widespread that windmills were reduced to being merely picturesque additions to the American landscape. This changed in the 1980s, when rising oil prices led to a renewed interest in wind energy. State subsidies and favourable policies caused wind energy to lift off in a big way in California. Other states followed suit, but still California generates twice as much energy from wind, than any other American state. How Wind Energy Machines work Traditional windmills consist of blades that rotate when the wind blows. These are connected to a shaft, which can either power a pump or turn an electric generator. The amount of energy produced by a wind machine depends upon the wind speed and the size of the blades in the machine. In general, when the wind speed doubles, the power produced increases eight times. Larger blades capture more wind. As the diameter of the circle formed by the blades doubles, the power increases four times. The actual process of converting the wind’s kinetic energy into more usable forms is as follows – - The wind blows on the blades, making them rotate. - The rotation of the blades turns a shaft inside the nacelle (the box at the top of the turbine). - The shaft is connected to a gearbox which shifts gears to increase the rotation speed enough to crank up the generator. - The generator, similar to ones found in conventional power stations, works on principles of electromagnetism, converting rotational energy into electrical energy. - The electrical output enters a transformer, which adjusts the voltage to one that is suitable for the distribution system. Types of Wind Energy Machines Wind machines are of two types, depending on whether the shaft is horizontal or vertical. Ones with horizontal shafts, which are very tall and wide to gather the maximum wind, are more popular. This shaft transmits power through a series of gears, which provide power to a water pump or electric generator. Their blades are like airplane propellers, and typically stand tall. In fact a horizontal axis wind turbine could even be as tall as a 20-storey building. The largest wind machine in the world has blades longer than a football field! The vertical axis machines have up to four long curved blades on a vertical shaft. Their blades go from top to bottom and look like giant eggbeaters in shape. These are typically about 100 feet tall and 50 feet wide, and make up only a small percentage of wind machines presently in use. The latest wind energy system, the Wind Amplified Rotor Platform (WARP) uses lesser land and is more efficient than the other wind machines in use today. Instead of blades, this system has what looks like a stack of wheel rims, each outfitted with a pair of small, high capacity turbines. Its manufacturers, Eneco plan to market WARP to power offshore oil platforms and wireless telecommunications systems. (for more on WARP, see ) Basic Requirements for a Wind Farm An area where a number of wind electric generators are installed is called a wind farm. Here is a list of considerations to keep in mind in order to develop a Wind Farm – - Selecting the right location for a wind farm is very important. Look for open areas that are high above the ground, for as a rule, wind speed increases with altitude and over open land with no windbreaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling. - There should be enough land available, for existing windmill technologies require a lot of space. - Look out for a power grid nearby to explore the possibilities of connecting the wind energy output to it. - If the Wind Machine is a small one, ensure it is close to the place where the power is to be consumes, to minimize transmission and distribution costs. The biggest advantage of using wind as an energy source is that it is completely renewable, free and causes no harmful emissions. Also, global wind mapping has revealed that Wind Energy is only second to Solar Energy in its potential for addressing the world’s energy requirements. It is also relatively cheap. Looking at leveled costs over twenty years, wind energy is the cheapest source of electricity. Unlike in conventional power projects, the cost per kilo watt hour reduces over a period of time as against rising cost for conventional power projects. Wind energy projects require little or no investment in manpower. In recognition of its immense potential, many players from the conventional fossil fuel and power sectors have entered the global wind energy market. Some of these include Shell, General Electric, ABB, Siemens, AES and Florida Power and Light. Wind power, has long been considered to be as fickle as wind itself. Since the wind does not blow strongly enough to produce power all the time, energy from wind machines is considered "intermittent," that is, it comes and goes. Therefore, electricity from wind machines must have a back-up supply from another source. Further, this means that utility companies can use it for only part of their total energy needs. Electricity produced by wind power often fluctuates in voltage and wattage, which makes it difficult to link it to a conventional utility grid. Windmills and their blades are easily damaged by lightening and high winds. Their parts are difficult to replace and expensive to repair. The rotating blades of Wind Energy Machines are often noisy and a nuisance for people living nearby. There have also been many cases of bird mortality because of the rotor blades of wind machines. Many critics of the larger Wind Energy Machines feel that they have little aesthetic appeal and detract from the landscape’s natural beauty. New Applications Smaller wind turbines are now being developed for generating electricity, heating, and pumping water in remote sites. Thanks to them, thousands of Mongolian nomads use modern micro turbines to boil water for tea. Central Americans use them to power refrigerators to store fish for delivery to nearby markets. Antarctic explorers use them to power their isolated base camps. Recently, students at the Department of Industrial Design at Indian Institute of Technology, Delhi designed an even smaller wind turbine which can charge mobile phones. The pocket-size turbine generates three to four watts of electricity, enough to charge mobile phones, and costs merely Rs 200. New research on Wind Energy machines by scientists at Stanford University has revealed ways in which wind farms can supply regular, not intermittent power. By running the power generated through powerful transformers to control voltage, and interconnecting wind farms with a transmission grid – wind energy can become as consistent a power source as coal power plants. - World Wind Energy Association - Connecting Wind Farms Can Make A More Reliable And Cheaper Power Source - WIND: A GLOBAL POWER SOURCE To view Global and local wind maps, go to http://www.windenergy.com/global_frame.htm and http://www.ocean.udel.edu/windpower/ResourceMap/index-world.html For a comprehensive list of Wind Machine Suppliers, go to http://www.eco-web.com/index/category/7.6.html
Workers recovered 40 fossilized meteorites ranging from one to 20 centimeters in diameters from a limestone quarry in southern Sweden. Birger Schmitz, now at Rice University, and his colleagues at the Earth Sciences Center in Göteborg, Sweden, then searched ancient marine sediments preserved at the site for tiny grains from decomposed meteorites. "What we are doing is astronomy, but instead of looking up at the stars, we are looking down into the earth," Schmitz says. Specifically, the researchers looked for traces of the mineral chromite, which is a signature of an extraterrestrial body known as the L-chondrite parent body that broke up around 500 million years ago. The size and number of the grains recovered indicate that the asteroid explosion that spawned the meteorite shower was "one of the largest bodies that disrupted the asteroid belt during its late history." Signs of a heightened bombardment by meteors were consistent over the entire 250,000-square-kilometer area that the scientists studied. The team will next head to China to search for asteroid remains dating from the same time period, and Schmitz notes that several sites in South America hold promise for yielding well-preserved chromite evidence as well.
Hero Engine (third law of motion) Replica of a Hero's Engine. © Sussex Steam Company\John Whitehouse - K-2 3-5 6-8 Students use the thrust produced by falling water to investigate Newton’s Third Law of Motion. Student teams will construct water-propelled engines out of soft drink cans and investigate ways to increase the action-reaction thrust produced by water shooting out of holes punched in the can sides. The "Hero Engine" activity is from the Rockets Educators Guide. Although grade levels are suggested, small modifications will enable more complex activities to be used successfully with other grade levels for observation, demonstration or complete lessons. Funded by the following grant(s) This publication is by the National Aeronautics and Space Administration, NASA Kennedy Space Center, and released into the Public Domain. Permission is not required for duplication.
- Human Evolution Research - Climate and Human Evolution - Anthropocene: The Age of Humans - Asian Research Projects - East African Research Projects - Human Origins Program Team - What's Hot In Human Origins? - Fossil Forensics: Interactive - E. A. Mammal Dentition Database - Human Evolution Evidence - 3D Collection - Human Fossils - Human Family Tree - Timeline Interactive - Human Characteristics - About Us It's All in Your Head: An Investigation of Human Ancestry (Grades 9-12) Author/Source: ENSI (via Understanding Evolution) - All organisms, including humans, retain evidence of their evolutionary history. - The fossil record contains transitional forms. - Anatomical similarities of living things reflect common ancestry. - Scientists pose, test, and revise multiple hypotheses to explain what they observe. - Scientific ideas are developed through reasoning. - Scientists use the similarity of DNA nucleotide sequences to infer the relatedness of taxa. - Scientists use fossils (including sequences of fossils showing gradual change over time) to learn about past life. Grade Level: 9-12 Time: One to two class periods Teaching Tips: Casts of skulls are necessary; however, the lesson also provides a collection of hominoid photos to accomodate a greater number of measurements. The author provides an excellent list of discussion questions.
my car is (probably) a different color than your car, even if we both own ford mustangs. an 'instance' refers to a specific object that has been created of a given class. each and every car that rolls of the assembly plant is an instance of the car, with it's own color, VIN, odometer reading, etc, but they are all of the same 'Ford Mustang' class. [ October 27, 2008: Message edited by: fred rosenberger ] There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors Joined: Jun 28, 2008 i need some more clarification, still i have not understood. i am repeating my query, "object says-- my instance variable values can be diffferent from my buddy's values." I think the book is referring to "buddy's" as another implementation of the respective class. For example, you have your blueprint/superclass named Car with an String instance variable of Color. Now you have two classes that extend Car named Mustang and Bronco. Both of the subclasses will have access to their own Color instance variable from Car, however; it can have different values. They simply mean that two different instances of the class can have different values. Let's say there exists a factory method called "getMustang()". You call it like this: Mustang myMustang = getMustang("Blue"); you get a blue mustang. Now you're a nice guy. you have a buddy or friend who wants a mustang, but he wants a red one. So, you can call the method again: Mustang myBuddysMustang = getMustang("Red"); now you have two Mustang objects - one is yours, and one is your buddy's. Both have a 'color' instance variable to hold what color the Mustang is, but the two (yours and your buddy's) hold DIFFERENT values.
Description of Wisdom The Wisdom symbol consists in an arrow, of which the shaft is a wavy or meandering line. The arrow moves at a slight diagonal and the arrowhead is pointing downwards and to the left. This represents wisdom and specifically a person who is wise and true to themselves. If the arrowhead were to point downwards and to the left, the symbol would represent far-sight and impressive powers of observation. General American Native Rock Art description American Native Rock Art is found predominantly in the Southwest United States of America. Utah, New Mexico and Tesco also contain a significant number of surviving occurrences. All are either pictographs: drawings or paintings made on rocks; or petroglyphs: images carved into the rock. Native Rock Art found in the United States of America can date from as long ago as 3000 BC. Much of it is extremely ancient, while more recent examples contain symbols that are common to many tribes, and so it is hard to say much that is definitive about the peoples who made these images. Some symbols stood for human character traits, like wisdom or far-sightedness, while others represent abstract concepts such as wealth or creativity. Other symbols told myths and histories that involved the tribe’s travels, achievements or successful hunting expeditions. Some, likely, serve as warnings. Though some of these symbols were carved onto stone, at least one belief system says that the stones themselves are bodies of the ‘stone people’. Legends hold that the symbols were burned into the stone people by the gods using lightning strikes. Many large Native American rock carvings and pictographs still exist to this day, and are treated as significant cultural and historical artefacts in the United States of America.
Poorest, Most Vulnerable Countries Face Worst Impacts if Warming Pushes Past 1.5° to 2.0°C The world’s poorest nations will see the biggest local climatic shifts at the margin between 1.5° and 2.0°C average global warming, even though they often have the least capacity to adapt to those impacts, according to a study published late last month in the journal Geophysical Research Letters. While the vast majority of the world’s population will feel the effects of heat waves, changing rainfall patterns, rising sea levels, and other climate effects as the atmosphere warms, poor countries will be hardest hit, researchers Dr. Andrew King and Luke Harrington explain in a guest post for Carbon Brief. Like this story? Subscribe to The Energy Mix and never miss an edition of our free e-digest. “The weather we experience every day is a combination of the long-term trend of climate change—the ‘signal’—and the short-term fluctuations of natural variability—the ‘noise’,” they explain. Separating those effects shows that, “in general, missing the 1.5°C limit and reaching 2,0°C of warming will mean a more palpable change in local temperatures in the tropics than at higher latitudes.” Past research has shown that poorer regions of the world have seen climate impacts first and worst. King and Harrington projected into the future by comparing their signal-to-noise ratio with 2010 GDP data for different parts of the world, to “investigate the relationship between local climate change and current wealth patterns,” they write. “As the less economically developed areas of the world tend to be in the tropics and the more developed economies are in the higher latitudes, we see a strong inverse relationship,” they note. “This mean, in general, the wealthiest will experience less perceptible climate change than the poorest.” By projecting a set of future scenarios called “shared socioeconomic pathways” to mid- century, they spotted severe consequences for developing countries as average global warming pushes past the 1.5°C threshold. “This result is remarkably clear given we are only examining a half-a-degree difference in global temperature,” they note. “Low-income countries are consistently the ones which will experience the largest perceptible shifts in local climate beyond the 1.5C limit. And these countries often have a limited capacity to adapt to a changing climate.”
Infectious diseases, also known as transmissible diseases or communicable diseases, comprise clinically evident illness (i.e., characteristic medical signs and/or symptoms of disease) resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism. In certain cases, infectious diseases may be asymptomatic for much or even all of their course in a given host. In the latter case, the disease may only be defined as a “disease” (which by definition means an illness) in hosts who secondarily become ill after contact with an asymptomatic carrier. An infection is not synonymous with an infectious disease, as some infections do not cause illness in a host. Infectious pathogens include some viruses, bacteria, fungi, protozoa, multicellular parasites, and aberrant proteins known as prions. These pathogens are the cause of disease epidemics, in the sense that without the pathogen, no infectious epidemic occurs. The term infectivity describes the ability of an organism to enter, survive and multiply in the host, while the infectiousness of a disease indicates the comparative ease with which the disease is transmitted to other hosts. Transmission of pathogen can occur in various ways including physical contact, contaminated food, body fluids, objects, airborne inhalation, or through vector organisms. Infectious diseases are sometimes called “contagious” when they are easily transmitted by contact with an ill person or their secretions (e.g., influenza). Thus, a contagious disease is a subset of infectious disease that is especially infective or easily transmitted. Other types of infectious/transmissible/communicable diseases with more specialized routes of infection, such as vector transmission or sexual transmission, are usually not regarded as “contagious,” and often do not require medical isolation (sometimes loosely called quarantine) of victims. However, this specialized connotation of the word “contagious” and “contagious disease” (easy transmissibility) is not always respected in popular use.
Nematodes belong to the phylum Nematoda and are multicellular organisms reminiscent of un-segmented worms. Nematodes are rounded at both ends and are very small in size, usually measured in mm, but can sometimes reach a few cm. The phylum Nematoda is comprised of over 28 000 species which have been described and a large portion of these species are parasitic in nature. Nematodes have evolved to adapt to a wide range of habitats including a range of elevations, every part of the Earth’s lithosphere and on the ocean floor. In terms of their anatomy, nematodes are not largely complex, but have interesting characteristics. Some important features of nematodes include: - The head of a nematode is distinct and radially symmetrical, whereas the rest of the body is bilaterally symmetrical - The epidermis of a nematode is covered by a collagenous cuticle which can have two to three complex layers - Their mouth is composed of multiple lips and they bear teeth - They have no stomach and thus, nutrients are absorbed by the cells of their gut lining - It is from body movements that food moves through the digestive system - Nematodes have muscles and they have nerves Figure 1. This image is representative of a nematode, specifically a soybean cyst nematode1. In terms of reproduction, female nematodes lay eggs and during favourable conditions, a larger number of eggs get produced. These eggs are either laid inside or outside of a plant and will hatch when the land is suitable. Thus, eggs can remain dormant for long periods of time if conditions are harsh since they have an outer shell for protection. Evidently, nematodes resemble yet another unique life form existing on this planet. Although nematodes are often parasitic and harmful to humans, it is still important to study these organisms as they are part of the diversity existent on Earth. 1. Wikimedia Commons. (2006). Soybean cyst nematode and egg. Retrieved from http://en.wikipedia.org/wiki/File:Soybean_cyst_nematode_and_egg_SEM.jpg Title Image Credit: Wikimedia Commons
The sudden and near-constant stream of news reports about swine flu can cause anyone to feel anxious and worried. These reactions are understandable because there are unknowns about the spread and severity of the illness. Even during this period of uncertainty, you can take several steps to manage your anxiety and have a positive outlook. Keep things in perspective. Government officials need to prepare for worst-case scenarios in order to protect the public. The public, however, does not need to expect the worst. To date, the cases that have been identified in the United States are not severe. Americans who have contracted the illness have recovered. Get the facts. Gather information that will help you accurately determine your risk so that you can take reasonable precautions. Find a credible source you can trust such as news from the U.S. Centers for Disease Control (cdc.gov/h1n1), a local or state public health agency, or local elected official such as a state governor. This is a rapidly evolving situation, so gather information at regular intervals in order to help you distinguish facts from rumors. Be wary of unsubstantiated rumors, which can be upsetting and may deter you from taking appropriate action. Maintain a hopeful outlook. Public health agencies around the globe are working on identifying outbreaks of the illness and to ensure the availability of the best medical care to those who are sick. Throughout the centuries, people have survived difficult life circumstances and gone on to live fulfilling and productive lives. There is no reason why this situation cannot be similar. Limit worry and agitation by lessening the time you and your family spend watching or listening to upsetting media coverage. Stay healthy. A healthy lifestyle—including proper diet and exercise—is your best defense against any disease threat. Adopting hygienic habits such as washing your hands regularly will also minimize your exposure to all types of germs and disease sources. A healthy body can have a positive impact on your thoughts and emotions, enabling you to make better decisions and deal with the flu's uncertainties. Build resilience. Resilience is the process of adapting well in the face of adversity, threats or significant sources of stress. Draw on skills you have used in the past that have helped you to manage life's adversities and use those skills to help you manage your emotions during this challenging time. Keep connected. Maintaining social networks can foster a sense of normality, and provide valuable outlets for sharing feelings and relieving stress. If officials have recommended limiting your social contact to contain an outbreak, you can stay connected via e-mail and telephone. Seek additional help. If you have intense feelings of anxiety or hopelessness or are having trouble performing your job or other daily activities, a licensed mental health professional such as a psychologist can help you develop an appropriate strategy for moving forward. If you would like to speak to a counselor call us at 212.229.1671 option 1.
- The rules of war, or international humanitarian law (as it is known formally) are a set of international rules that set out what can and cannot be done during an armed conflict. - The main purpose of international humanitarian law (IHL) is to maintain some humanity in armed conflicts, saving lives and reducing suffering. - To do that, IHL regulates how wars are fought, balancing two aspects: weakening the enemy and limiting suffering. - The rules of war are universal. The Geneva Conventions (which are the core element of IHL) have been ratified by all 196 states. Very few international treaties have this level of support. - Everyone fighting a war needs to respect IHL, both governmental forces and non-State armed groups. - If the rules of war are broken, there are consequences. War crimes are documented and investigated by States and international courts. Individuals can be prosecuted for war crimes. In this short clip we tell you all about the rules of war: Without the rules of war, we all lose.
Want to know where Cymbeline is set? See each setting Shakespeare used in the play on the map below. Shakespeare was ‘thinking deep’ in setting Cymbeline. It’s set in the middle ages in a mythical England and a Rome that is very different from the Rome of Shakespeare’s great Roman plays. It is more like the Renaissance cities Shakespeare creates in other plays, such as Verona in Romeo and Juliet. Shakespeare reminds us all the time of the setting by referring to the two places. He uses the word Britain rather than England because in this play the idea of Empire is central. It is to some extent about the tension between the two empires of Rome and Britain, the first in a decadent state and the second beginning to flourish. The old and the new. The play’s major ambiguity is that Rome is the ruler of Britain and its equal at the same time. The map below shows all the locations Shakespeare used for Cymbeline. You can zoom in on the map for a more detailed view of an area, and click the icons on the map for more information. Text in the more info box are the specific locations Shakespeare references in his Cymbeline text.
Issue Date: September 1, 2008 Tracking Ocean Iron OF ALL THE trace metals in the ocean, iron is the most important for sustaining life. That's because many marine organisms living in surface waters use enzymes that require dissolved iron for vital processes such as photosynthesis. But dissolved iron is scarce in surface waters because it is constantly converted into particles that sink into the deep sea and settle into sediments. For decades, oceanographers thought atmospheric mineral dust was the major source of dissolved . . . You Do Not Have Access to C&EN Protected Content. - Chemical & Engineering News - ISSN 0009-2347 - Copyright © American Chemical Society
1. My friend and I each had a piece of paper the same shape. We each cut our shape in halves but when I looked I saw that my halves were a different shape than my friend’s halves. What might our original pieces of paper have looked like? 2. Teddy’s sister draw a shape on his notebook. The shape makes him think of a rectangle, but it is not a rectangle. what could the shape be? Explain your answer. 1. A school cook has 9 1/2 gallons of milk. If each child receives one cup of milk with their lunch, how many children can the cook serve? How many gallons would the cook need to serve 160 students? Explain your answer. 2. Andy has made a puzzle. He takes a whole circle and cuts the whole into half. He takes the half and cuts it in half. Finally he takes the small piece he cut and cuts that in half. How many of these small pieces can he put together to make the same size rectangle that she startet with? Explain your answer. 3. Draw a small rectangle. Draw a bigger rectangle that the smaller one is part of. Tell what fraction of the big recrangle the small one is. 1. The pet store has 37 gold fish. The manager needs to buy fish bowls for the fish. She can only put three fish in each of the fish bowls. How many bowls does she need to buy? 2. Tyson has 7 cows, 4 horses, and some chickens on his farm. How many legs do the farm animals have in all? Explain your answer. Could there be 33 legs in all? 3. The Cardinals and Raiders needs 49 points to win a game. The Cardinals’ score is less than 28 points. How many points did the Raiders need win the game? 4. If a chicken lays 3 eggs a day, how long will it take the farmer to collect 5 dozen eggs? 5. One worker at Kroger Bakery can make 24 loaves of bread in one hour. Each worker has an 8 hour shift. At the end of the shift, the worker must pack his or her bread into cartons. If each carton contains the same number of loaves, what are some possible ways to pack the loaves into cartons? 6. What if you had 24 pieces of candy for yourself and some friends? How many friends could you share the candy with and how many would you each get? Remember to be fair and share the candy equally. Show and explain how you solved the problem. What happens if you share the 24 pieces of candy with a different number of friends? Show and explain how you solved the problem. How many different ways could the candy be shared equally among friends? 7. Choose two numbers and compare them. Which one is smaller and how much smaller. Tell how you know. 1. Given the following number line, place an x where 324 is approximately \|300——————————-400\| Explain with words how you determined where the x should be placed. 2. Mrs. B. left school at 3:25. She had to stop at the Dr’s office, that was 15 minutes from school. Then, she went to the grocery store. It took her 30 minutes to buy what she needed for dinner. After going to the store she drove home. What time could Mrs. B. have gotten home? Explain how you got your answer with words or pictures. 3. Dan had some money, all dollar bills larger than $1. He bought a movie for $16.50 and spent $6.50 on candy. Explain how much money Dan could have started with. 4. Look at a page of a story book that has both text and picture. Which area is greater? The area for the text or the area for the picture? 1. Use pattern blocks to make shape pictures. Use as many different shapes as you can. Describe the properties of your picture and tell why you used those shapes. 2. Hoe are these shapes alike? How are they different? 3. select one shape. Cut it in 5 pieces. Give it to your friend to put together. 1. What can you find in your classroom that is around as long as your legs? 2. Describe one object that is shorter than your height. Tell how you know it is shorter. 3. Describe one thing that weight less than your bag. How you know it weights less than the bag? 4. you want to buy a plastic cover for your table. what do you need to measure and how would you measure it? 1. A two digit number has more tens than ones. what could the number be? how do you know your number is correct? 2. How are the number 10 and 14 alike? how are they different? 3. Replace the box with valued from 1 to 9 to make each problem true. you can use each number as often as you want. 1. Show the number 5 in as many different way as you can. 2. The answer is 6. what is the question. 3. Cindy had a party. She invited two guests. Her guests each invited four guests, and then those guests each invited three guests. How many people were at Cindy’s party? Explain how you determined your solution. 4. Make up a subtraction question where there is a 4, a 5 and a 6 somewhere in the question or answer. 1. Consider the outline of the figure below. Investigate how to cover up that outline by arranging different blocks to fit into the space exactly. If you were to use only one type of block, which block can be used to cover the outline? 1. You have 10 different rods – each a different color and a different length. If you use just the red rods and put them together in a train (one next to each other), what other length rods could you make? List the other rods by color. Explain why only some rods work.
Northern Ecuador’s Condor Bioreserve stretches from Andean grasslands to Amazon rainforests. Its mountain streams trickle into rivers that supply water to the capital of Quito. The region is a sanctuary for the endangered spectacled bear and the Andean condor, the world’s largest flying bird. A top conservation priority, the bioreserve is threatened by unsustainable farming, over-grazing, logging, illegal hunting, and intentionally set fires. Local communities depend on natural resources to survive, yet come into conflict with wildlife when bears attack cattle pasturing near their habitat, costing families thousands of dollars a year. USAID is working to protect the reserve through several initiatives. Programs in several villages hire, train, and equip residents to be park rangers and provide guard stations, two-way radios, patrol vehicles, and training on habitat protection. Local residents learn how to reduce poaching, illegal logging, and fires. Other programs focus on promoting ecotourism, which can bring revenue through low-impact activities like nature hikes, controlled sport fishing, and camping. USAID is also supporting efforts to study bear habitats to help farmers identify less vulnerable locations for raising their livestock. The results have been remarkable. About two years into the program, deforestation has declined and the number of intentionally set fires has dropped 35 percent. Illegal hunting and fishing have been curtailed as local communities increasingly realize the benefits of ecotourism. Identification of bear habitats, which has helped herders find safer grazing grounds, has led to a drop in the number of livestock attacks. The village of Oyacachi had only four incidents in 2004, down from 20 the year before. By working to protect the environment, endangered native species, and the livelihoods of local residents, USAID is helping preserve an important ecological and cultural area of Ecuador so that future generations can continue to benefit from its wealth. Last updated: June 01, 2016
Multimeter is also known as multiplex table, multimeter, three-meter, multi-purpose table, etc. It is indispensable for power electronics and other departments >Measurement instruments, generally with the main purpose of measuring voltage, current and resistance. The multimeter is a multi-function, multi-range measuring instrument. The general multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance and audio level, etc., and some can also measure AC current. Capacitance quantity, inductance quantity and some parameters of semiconductor. The multimeter is divided into a pointer multimeter and a digital multimeter according to the display mode. 1, multimeter diode file or resistor file can measure circuit board fault, if using diode file When using the test leads to measure the points to be tested, if the circuit board is short-circuited, it will ring, if there is a indicator on the multimeter >Light, or resistance file,If it is a short circuit, the display of the multimeter is zero. 2. Measurement of DC voltage: First insert the black test pen into the “com” hole and the red test pen into the “V Ω”. The value can be read directly from the display. If the display is “1.”, it means that the range is too small, then it is necessary to add a large amount of time to measure the industrial electrical equipment. Select the knob to a range larger than the estimated value (Note: the values on the dial are the maximum range, “V-” means DC voltage, “V~” means AC voltage, “A” is current), then Connect the meter to the power supply or both ends of the power supply; keep the contact stable. If “-” appears to the left of the value, it indicates that the polarity of the test leads is opposite to the actual power supply polarity. At this time, the red test lead is connected to the negative pole. 3. Measurement of AC voltage: The test lead jack is the same as the DC voltage measurement, but the knob should be switched to the AC position “V~” The required range can be. There is no positive or negative AC voltage, and the measurement method is the same as before. Regardless of the AC or DC voltage, pay attention to personal safety. Do not touch the metal part of the test lead with your hand. 4. Measurement of resistance: turn the range switch > Dial to the appropriate range of Ω, insert the red test lead into the V/Ω hole, and insert the black test lead into the COM hole. If the measured resistance value exceeds the maximum value of the selected range, the multimeter will display .1. At this time, a higher range should be selected. When measuring resistance, the red test pen is positive and the black test pen is negative, which is the opposite of the analog multimeter. Therefore, when measuring polarized components such as transistors and electrolytic capacitors, attention must be paid to the polarity of the test leads. 5. Measure the current with a multimeter: first select the range, the multimeter’s DC current file has “mA” with 1mA, 1omA, 100mA three-range range. The range selected should be based on the current in the circuit. The multimeter should then be placed in series with the circuit under test. After disconnecting the corresponding part of the circuit, connect the multimeter to the ends of the breakpoint. Finally, the correct reading, the DC current scale is still the second. If the 100mA is selected, the third line can be used, and the reading can be multiplied by 10. 6. Measuring capacitance with a multimeter: Some digital multimeters have the function of measuring capacitance. The range is divided into 2000p, 20n, 200n, 2μ and 20μ. During measurement, the two pins of the discharged capacitor can be directly inserted into the Cx jack on the board, and the display data can be read after selecting the appropriate range. Precautions for use: - 1) Before using the multimeter, first perform “Mechanical zeroing”, that is, when there is no measured power, make the multimeter pointer point to zero voltage or zero current. - 2) In the process of using the multimeter, you can not touch the metal part of the test pen by hand, so as to ensure the accuracy of the measurement on the one hand and personal safety on the other hand. - 3) When measuring a certain amount of power, you cannot shift gears while measuring, especially when measuring high voltage or high current. Will destroy the multimeter. If you need to shift gears, you should first disconnect the test leads and then measure them after shifting. - 4) When the multimeter is in use, it must be level Place it to avoid errors. Also, be careful to avoid the influence of external magnetic fields on the multimeter. - 5) When the multimeter is used, the switch should be placed in the exchange The maximum block of voltage.If it is not used for a long time, the battery inside the multimeter should be taken out to prevent the battery from corroding other devices in the watch.
Hal May needs a microscope to see his workmates, but wonders if eventually it will take an environment as large as an ocean to reach their potential. In his lab at the Hollings Marine Laboratory at Fort Johnson on Charleston Harbor, May and his staff have found methods to induce microbes to produce various chemicals and fuels that eventually could have commercial value, and do it at minimal cost in a relatively new process called microbial electrosynthesis. With this process, electricity is used as an energy source to feed microbes and stimulate them into producing a variety of organic compounds. We've gotten a long way on fossil-based systems, but in the long run, there are these issues with carbon released into the atmosphere, as well as someday, you will run out (of fossil fuels). Hal May, Ph.D. “You take electricity, carbon dioxide, water, and microbes, and you say ‘make something’ which also means they have to make a living out of this,” he says. “The electricity is their energy source. We all have to have an energy source –theirs is electricity. We all have to have a carbon source – their carbon source is carbon dioxide.” May, an environmental microbiologist with a Ph.D. from Virginia Tech, initially succeeded in getting microbes to generate electrical current, but eventually concentrated on feeding electricity to microbes to make other products. This project came in response to an initiative from the U.S. Department of Energy’s Advanced Research Projects Agency (ARPA), seeking innovative shortcuts to make chemicals and fuels from carbon dioxide. “’We don’t want to use fossil fuels and we don’t want to use photosynthesis. We just want to make it straight up from carbon dioxide,’” May recalls the DOE’s directive, “which was a bit of a tall order.” “So I proposed (that) you could put an electrode in (with microbes) and that could be the energy source for these things. The reason I proposed that was because I knew the reverse was true. We can make electricity in an electrode with microbes, but can we get microbes to consume electricity in an electrode, just turn the process around. That was the basis of my hypothesis,” May explains. Microbes can be found practically everywhere – in the air, ground, water and in living creatures, and they can thrive in dramatically different environments. May and his research assistants made an extensive search looking for the right microbes, and found the best candidates in a cistern behind a local beer brewery. “Of all the different sources we’ve been using, that’s the one that worked,” May says. “Different stages of fermentation and different types of fermentation. In the end, all of that gets washed out of the tanks and goes into a cistern at the back of the building as a pretreatment before they can release it legally into the Charleston wastewater system. You would expect most of what is in there: a bunch of yeast, leftover sugars, alcohol, vitamins, a few other intermediate fermentation items. That all goes back in the cistern and becomes an even bigger, nastier brew. \|May's microbes, with a little electric current, can produce a variety of compounds, including hydrogen, acetic acid and methane. \|\| \| “It’s not sterile, of course. They don’t want it to be sterile. They want it to consume as much waste as possible before it goes into the wastewater treatment system. From a microbiology standpoint, that’s wonderful. That means you have a very happy, active population of microorganisms that you feed every day, and they’ve been feeding them for years. So that means you’ve got them well adapted to do whatever crazy things they’re doing in there.” On a rainy day, May and his research assistants collected a batch of the brewery’s tiny inhabitants and brought them back to his lab. Fortunately, for May anyway, they had traveled in separate vehicles to the brewery, and he chose to let the students bring the microbes back with them, “because you don’t want to smell your car for a week after that stuff’s been in there.” From there, it was a matter of configuring the microbes to become proficient at their task by adjusting the amount of voltage to use, proper temperature and pH, and how much carbon dioxide to give them, among other factors. Eventually, May and his staff begin to observe the brewery microbes drawing noticeable amounts of electric current. “That told us something was off to the races,” he says. Microbes, it turns out, are capable of producing a variety of organic compounds. “It’s how we discovered antibiotics, microbes producing antibiotics and antibiotics are pretty complex molecules,” May explains. “The microbial world has a tremendous capability to make lots of different compounds, from anything to plastic precursors to fuels to drugs.” “What May’s microbes have primarily produced so far are hydrogen, acetic acid and methane. Potentially, several other compounds could be produced, many of them with commercial applications, although May says that stage is a long way off. “If we can produce hydrogen acetate, theoretically you could then make ethanol from that. If you can make hydrogen and butyrate, theoretically you could make butanol. Each of those could be a fuel. You could even convert some products into bioplastics,” he says. Acetic acid, for example, already has a huge market in the production of polymers, paints and plastics. The same goes for hydrogen, which can be used as a fuel or as an ingredient in other products. Then there is the sustainability factor. May’s lab uses nothing more than electric current and carbon dioxide to get results. Nothing else, at least at this stage, is needed, making it extremely cost-effective. In fact, based on a hypothetical rate of five cents per kilowatt-hour, May’s lab can produce 60 cents worth of acetic acid with only 35 cents of electricity. ‘We’ve gotten a long way on fossil-based systems, but in the long run, there are these issues with carbon released into the atmosphere,” May says about current production methods, “as well as someday, you will run out (of fossil fuels).“ The challenge, of course, is to produce a high enough volume of these compounds to make them commercially viable. May has broached that subject with some engineering firms to explore the possibility. Eventually, the solution may be only a short distance from his Fort Johnson location – the Atlantic Ocean. “The ocean is gargantuan and captures CO2 more so than fresh water,” he explains. “If you could build a reactor and use marine water, you could use the CO2 from the ocean and convert it into a useful chemical. I want to see if we can leverage the ocean for this.” May is also interested in the ocean for other reasons. “The diversity of organisms in the ocean is so vast, we may find another microbe out there that will do this very well or make a different chemical. I want to go look.” This story is part of MUSC's Annual Report 2011-2012: The Greening of MUSC. To see the full version, visit this site.
Pragmatic Language Tips Parents, cargivers, families, and teachers can help individuals use language appropriately in social situations (pragmatics). Some general suggestions to help develop skills in three major pragmatic areas are listed below. Using Language for Different Purposes Ask questions or make suggestions to use language for different purposes: \|Desired Language Function \|\|Suggested Question or Comment \|\|"What did you do?" "Tell me about..." \|\|"Tell your friend..." "What do you want?" Respond to the intended message rather than correcting the pronunciation or grammar. Be sure to provide an appropriate model in your own speech. For example, if an individual says, "That's how it doesn't go," respond, "You're right. That's not how it goes." Take advantage of naturally occurring situations. For example, practice greetings at the beginning of a day, or have the individual ask peers what they want to eat for dinner or request necessary materials to complete a project. Changing Language for Different Listeners or Situations Role-play conversations. Pretend to talk to different people in different situations. For example, set up a situation (or use one that occurs during the course of a day) in which the individual has to explain the same thing to different people, such as teaching the rules of a game, or how to make a cake. Model how the person should talk to a child versus an adult, or a family member versus a friend of the family. Encourage the use of persuasion. For example, ask the person what he or she would say to convince family members or loved ones to let him or her do something. Discuss different ways to present a message: - Polite ("Please may I go to the party?") versus impolite ("You better let me go") - Indirect ("That music is loud") versus direct ("Turn off the radio") - Discuss why some requests would be more persuasive than others Conversation and Storytelling Skills Comment on the topic of conversation before introducing a new topic. Add related information to encourage talking more about a particular topic. Provide visual cues such as pictures, objects, or a story outline to help tell a story in sequence. Encourage rephrasing or revising an unclear word or sentence. Provide an appropriate revision by asking, "Did you mean...?" Show how nonverbal signals are important to communication. For example, talk about what happens when a facial expression does not match the emotion expressed in a verbal message (e.g., using angry words while smiling). To contact a speech-language pathologist, visit ASHA ProFind.
First of all, what is all this talk about sodium "wanting," or "prefering" to do anything? Atoms don't have feelings. As far as gaining or losing electrons, if a sodium atom loses an electron, and a chlorine molecule happens to pick up that electron, NaCl(s) can form. This is way lower in potential energy than the reactants, so this reaction is spontaneous. Find lattice energy in the index and look at the diagram for this in your text. The student is correct in that E must be absorbed by Na to form Na+, and a little E is released in forming Cl-, but the majority of the E released is from the two ions coming together. As far as IE goes, if you check your gen chem text, the ionization energy for every single element is +, meaning it requires E to separate atoms from electrons. Does this mean that cations don't exist? Of course not. EA and IE are useful concepts/data to help explain what is going on in a chemical reaction, but these numbers are for gas phase reactions of atoms. About NaH: there isn't much support for this compound to be labeled as Na- and H+. This compound reacts with water (and other proton sources) to form H2 gas, leaving behind an anion (OH- if it's reacting with water). There is the odd Na- H+ compound, but someone worked really hard to make this: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12022811&dopt=Abstract So the original poster did a nice job questioning her prof, and trying to reason stuff out. But please, no more atomic feelings! Atoms gain or lose electrons to form compounds, but they don't do this unless enough energy is returned by new bonds forming. Check out the difference in the IE's of Na and then of Na+ and you can see the difference. Yes good point NaH is sodium which has gained an electron, -1 oxidation state, 1s2. So what is the right answer to the original question? I would say that sodium tends to lose an electron, what do others think? Should the answer be both lose and gain an electron? (maybe depends on the level of the student?)
The Goldilocks Zone refers to the habitable zone around a star where the temperature is just right - not too hot and not too cold - for liquid water to exist on an planet. Liquid water is essential for life as we know it. Where we find liquid water on Earth we also find life. "The only life we know about is our carbon-based life, and water plays a crucial part in our own existence, and so it's only natural that we direct our attention to planets in locations capable of having liquid water," Professor John Webb of the University of New South Wales said. There are at least a dozen or so potentially habitable exoplanets, planets which are in varying degrees similar to Earth.Professor John Webb "There's plenty of life on Earth and there's plenty of water, but we've yet to find life on other planets even in our own solar system." Looking for planets in the Goldilocks Zone is a way that allows scientists to hone in their search for Earth-like planets that could contain life. Basically, the assumption is that if it's possible there may be liquid water on the planet, then it's also possible that the planet may be habitable. Goldilocks Zones in other star systems "The location of a Goldilocks Zone around another star depends on the type of star," Professor Webb said. Bigger hotter stars have their Goldilocks Zones further out, while smaller cooler stars such as M-type red dwarf stars have habitable zones much closer in. Red dwarfs are the most common type of star in the Milky Way galaxy, and have very long life expectancies. "This means life should have lots of time to evolve and develop around such as star," he said. Observations by the European Southern Observatory's High Accuracy Radial velocity Planet Searcher, has concluded about 40 per cent of red dwarfs have super-Earth class planets orbiting in their habitable zone. Alternatively, NASA's planet hunting Kepler space telescope searches for planets orbiting in the habitable zones of Sun-like stars by looking for planets with an average 365-day orbit. More than just temperature Just because a planet or moon is in the Goldilocks Zone of a star, doesn't mean it's going to have life or even liquid water. After all, Earth isn't the only planet in the Sun's Goldilocks Zone - Venus and Mars are also in this habitable zone, but aren't currently habitable. "Venus is Earth's sister planet, both are about the same size and in the same region of the solar system, and Venus once also had water," Professor Webb said. "However, Venus now has a runaway greenhouse effect going on, with a surface temperature of over 460 degrees Celsius, which has boiled away all its liquid water." At the other end of the Sun's Goldilocks Zone is Mars which also once had liquid water flowing across its surface in rivers, lakes and oceans. "However, the Red Planet is now a freeze-dried desert, with a thin carbon dioxide atmosphere, and only one 99th the atmospheric pressure of sea level on Earth," Professor Webb said. "The lack of both a significant atmosphere and a global magnetic field - thanks to its mostly solidified core - means the Martian surface is constantly being irradiated by the Sun. "Any water still on Mars, which hasn't degassed into space and been blown away by the solar wind, or irradiated into hydroxyls on the surface, is either frozen in the planet's ice caps and permafrost, or quickly subducts directly from ice to gas during the local Martian summer." While there is some evidence pointing to the possible existence of subsurface salt water brines which can seep to the surface, we're yet to find any life on the Red Planet. "Finally, and much closer to home, we have a third terrestrial world, the Moon, which has virtually no atmosphere, just the hint of a dusty exosphere above its surface, and with the only water being either locked up as ice on the shaded floors of deep craters, or as hydroxyls on the irradiated lunar surface, and definitely no life," Professor Webb said. Getting it right is hard "If you want to calculate the average temperature that some exoplanet has, given its distance from its host star, you actually need to know a lot about that exoplanet, including the kind of atmosphere it has, the reflectivity of its clouds, and whether it has any kind of greenhouse effect," he said. "And the trouble is you actually don't know those things, so the calculations can give you the wrong answers." Professor Webb said Earth and Venus could be good examples of getting it wrong. "If you perform a simple calculation for Earth, taking into account the apparent reflectivity of our clouds, that is the sunlight that's being reflected back into space without heating the surface, and you ignore the effect of greenhouse gases, you can actually get the wrong answer and conclude that Earth is not habitable," he said. "And if you calculate the mean surface temperature of Venus based only on the reflectivity of its cloud cover, then one would expect a surface temperature of minus 10 Celsius, over 470 Celsius less than its actual surface temperature. "There are at least a dozen or so potentially habitable exoplanets, planets which are in varying degrees similar to Earth," Professor Webb said. For these reasons, he said we should relax our definition of the Goldilocks or the habitable zone around stars somewhat, or we could miss a major discovery. "Ultimately when the technology and methodology improves, we will be able to measure any atmosphere around these planets, and that might give us some clue to what's really going on there, but right now these things are very hard to do."
What Are Omega-3 Fatty Acids?Omega-3 fatty acids (also called "n-3s") are primarily found in certain cold water seafoods, including halibut, tuna and salmon, amongst others. They are also found in sea algae, some nuts and plant oils (particularly flaxseed oil). They are also called essential fatty acids because while the body cannot produce them on its own, they are essential to health. The reason why they are referred to in the plural ("acids") is because several different fatty acids occur in nature. Health Benefits of Omega-3 Fatty AcidsRemarkably, Omega-3 fatty acids are required by every cell in the body for optimum health. They have health benefits at every stage of life: - DHA (one of the most important n-3s) plays an important role in brain development, including both the development of motor and general cognitive skills. - DHA plays a part in the development and maintenance of eyesight. - "Long chain" Omega-3s (DHA and EPA) have anti-inflammatory effects that help maintain joint health and aid in the prevention of cardiovascular disease. What the Study ShowsOriginally publishing in the prestigious journal, Neurology (28 February 2012) and reported elsewhere online, lead author Dr. Zaldy Tan of the geriatric division at UCLA and the Easton Center for Alzheimer's Disease Research stated: "We feel fatty-acid consumption exerts a beneficial effect on brain aging by promoting vascular health". While earlier research has focused on Omega-3s found in blood plasma, Dr. Tan's team focused on n-3s found in the red blood cells. Because fatty acids are stored in the cells over time, this gave researchers a better idea of the average intake of foods containing these essential acids rather than the "snapshot" of recent use provided by plasma alone. Dr. Tan and his team measured levels of Omega-3s in the red blood cells of 1,575 study participants. The average age of the participants was 67, they were primarily caucasian and all were dementia-free. Approximately 3 months later, they were given MRI (magnetic resonance imaging) scans and standard mental functioning tests. The tests revealed that: - Those with the lowest levels of Omega-3s (the bottom percent) appeared to have less blood flow to the brain. - The bottom 25 percent had lower brain volumes than the top 75 percent overall. - Those with the least Omega-3s in their blood cells performed more poorly on tests measuring visual memory, attention and abstract thinking. While health officials recommend at least two servings of Omega-3 rich fish per week, an earlier study based on food intake surveys suggested that those who ate fish 3 times a week or more were even less at risk of developing vascular brain diseases such as dementia and Alzheimers. Other researchers stress the importance for brain health of the long chain Omega 3s found in fish (DHA and EPA) over the short chain n-3 (ALA) found in green vegetables and vegetable oils, though this, too, is essential for health.
This publications is also available as an ebook. See all ebooks. Author: Urban/Small Farm IPM Specialist, Los Lunas Agricultural Science Center, New Mexico State University. Integrated pest management (IPM) is an approach to managing pests that seeks to limit or suppress pest populations by using a variety of compatible tactics that minimize potential harmful effects on human health and the environment. Chemical controls (insecticides) are used only as a last resort. The concept of IPM was first developed in the late 1950s to address various issues that had arisen from the overuse of chemical controls for insect pests, including widespread environmental problems and resistance to insecticides (with consequent control failures). While IPM was originally developed in relation to insect problems, the basic approach is equally applicable to pests in the broader sense, such as weeds, nematodes, plant pathogens (i.e., disease-causing organisms), and vertebrate pests. The ultimate goal of a good IPM program is to keep populations of all potential pests below the level at which a pesticide is considered necessary. This is achieved through a combination of tactics that includes cultural, biological, and physical controls, with chemical controls being used only if other measures prove inadequate. The emphasis throughout is on managing pests (i.e., keeping them within tolerable limits), rather than on eliminating them. IPM begins with planning and choosing the correct plants for your particular site. Try to ensure that the plants that you select are suitable for your conditions; take into account the eventual height and width of the plants (particularly trees and shrubs), their preferences for soil type and pH (a measure of soil acidity), winter hardiness, and their tolerance of sun, shade, and drought. Plants not suited to your growing conditions will always be under some degree of physiological stress, and stressed plants are much more susceptible to pest and disease problems. Much can be done to prevent pest problems by paying close attention to plant health and regular maintenance. Correct irrigation and fertilization are particularly important; too much or too little of either water or fertilizer can trigger pest outbreaks. The condition of your soil is also important. Regular addition of well-composted (not fresh) plant wastes or animal manures helps increase the level of organic matter, which in turn will stimulate beneficial soil microbes and other organisms. These microbes can improve plant health by increasing the availability of certain nutrients, by helping prevent or reduce root colonization by disease-causing plant pathogens, and by stimulating the plants' own natural defenses against insect pests and diseases. If lawns are part of your landscape, make sure that mowing heights are appropriate (setting the blades too low, for example, can create bare patches that provide sites for weed establishment)1. Be particularly careful when mowing close to trees and shrubs because mechanical injury from the mower can provide points of entry for pest insects or disease organisms. Try to prevent an excessive build-up of dead "thatch" at soil level (e.g., by using mechanical aeration devices) since this can reduce irrigation efficiency and encourage problems such as chinch bugs. Correct irrigation and fertilization practices are as important for your lawn as for other elements of the home garden. Follow correct procedures for pruning (including fruit trees)2 since incorrect techniques (or timing) can stress the plants and make them more susceptible to pest problems. Finally, sanitation techniques such as the prompt removal and destruction of virus-infected plants or insect-infested fruit may also help reduce pest and disease build-up. All insects have a range of natural enemies that help provide some degree of control. These biological control agents include predatory invertebrates such as ladybird beetles ("ladybugs"), lacewings, ground beetles, rove beetles, big-eyed bugs, pirate bugs, hover flies, and many others. Equally important, but often less visible, are the parasitoids-various species of wasps and flies that lay their eggs on or in the body of a host insect; when the eggs hatch, the developing parasitoid larva feeds on the internal tissues of the host until the host dies. At that point, the parasitoid larva usually pupates inside the dead host, and eventually a new adult parasitoid emerges. Parasitoids tend to be more restricted than predators in the number of different insects that they can successfully attack, but nevertheless can be very effective biological control agents if given the chance. Populations of beneficial insects can be encouraged by minimizing the use of pesticides and by diversifying your plantings to include a variety of flowering plants. The adult stages of many beneficial insects benefit from having access to nectar and/or pollen, which can extend their lifespan and reproductive output, or, in some cases, sustain them when prey is scarce. Since beneficial insects differ widely in size and in their preferences for different flowers, it helps to grow a mixture of flowering species to provide a variety of flower shapes, sizes and blooming periods. The ideal is to provide continuous bloom for as much of the growing season as possible. Larger predators such as insectivorous birds are also important predators of insects, and if sufficient space is available you might want to consider installing nest boxes to encourage them. Both birds and beneficial insects will also benefit from a regular supply of fresh water, but remember to empty and clean out the container every few days to prevent the development of mosquito larvae. In enclosed or partially enclosed situations such as greenhouses and hoop houses, you may want to consider buying and releasing beneficial insects from a commercial insectary company. If the correct natural enemies are selected and the releases are done early enough (i.e., as soon as developing pest problems are detected and before their populations become too high), this approach can be very effective. However, it is not normally worth releasing beneficial insects in an open garden situation, as the insects will often disperse some distance away from the release site. These include both the physical removal of pests and using mechanisms designed to prevent them from reaching your plants in the first place. Hand-removal of pests, though laborious, can be effective on a small scale (e.g., with bagworms or squash bug egg masses). Preventative approaches include the use of floating row covers to cover newly emerged seedlings or transplants before they can be colonized by pest insects. This technique is most commonly used to protect vegetable crops from either direct pests or the vectors of plant pathogens (e.g., to protect brassicas from flea beetles, or to protect tomatoes and other species from the beet leafhopper that can transmit curly top virus) (Figure 1). To be effective, care must be taken to ensure that no pests are present before the covers are installed, that there are no holes in the covers, and that a good seal is maintained between the soil and the edges of the covers. For crops that require insect pollination, the covers must be removed once flowers are produced. Physical controls suitable for use in protected cropping situations include very fine mesh to cover ventilation openings and large-scale rolls of yellow plastic coated with insect-trapping glue; the latter will attract and capture a variety of greenhouse pests (e.g., thrips, whiteflies, and fungus gnats), but must be replaced when the trapping surface becomes saturated with either insects or wind-blown soil particles. Unfortunately, the yellow surface is also attractive to various beneficial insects, so avoid this technique if releasing biological control agents into the greenhouse. Figure 1. Floating row covers used to protect newly transplanted tomato plants from beet leafhopper (vector of curly top virus). In commercial situations, IPM usually includes a regularly scheduled program of pest monitoring together with formal treatment thresholds (also known as "action thresholds"). Application of insecticides is limited to situations when the pest population reaches the recommended treatment threshold. In a home garden, however, treatment thresholds for specific plants and pests may not be available, and pest monitoring (while still very important) tends to be more informal and less intensive. In home gardens, monitoring for pests and beneficials may simply involve regular visual inspection of plants while carrying out other garden chores. With insect pests, feeding damage is often more noticeable than the insect itself. Many chewing insects feed in very characteristic ways that can help with diagnosis (e.g., flea beetles create small, circular "shot holes" while adult vine weevils cut semi-circular notches in the margins of attacked leaves). The presence of sap-sucking pests (e.g., aphids, scale insects, whiteflies, and mealybugs) is often first noticed by the presence of a sticky coating of "honeydew" on the surface of the leaves. This sugary waste product is excreted as the insects feed, and typically falls on the leaves underneath the colony; examining the undersurface of leaves above the honeydew will often reveal the insects responsible. If the honeydew is not washed off by rain, it may become covered by black "sooty mold"; although this fungus is unsightly, it only damages the plant indirectly by reducing the amount of light reaching the leaves. Both the honeydew and the sooty mold can be washed off with water. Apart from careful visual checking, more formal methods of monitoring include the use of traps of various kinds (e.g., yellow sticky cards, pheromone traps, light traps, etc.). These are used for particular pests or situations, but a detailed explanation of their use lies outside the scope of this publication. Consult your local county Extension office for guidance on their use in relation to specific pests. Insecticides must be chosen and applied with care. Ideally, it is best to try to use a selective product, that is, one that will kill the pest while preserving beneficial insects. Unfortunately, few such products are available for use by home gardeners; most of the commonly available products (including many so-called "organic" products) are broad spectrum in nature and will kill both pest insects and their natural enemies. In some cases, this can result in secondary pest outbreaks, whereby spraying for one pest can create "new" pest problems through the destruction of predators and/or parasitoids that were keeping other potential pest species under control. Before proceeding with an insecticide application, double-check that you have correctly identified the pest (otherwise your control tactics are likely to fail), that the insect is in the correct stage for treatment (some stages are easier to kill than others), and that the product you plan to use is registered for the intended purpose in New Mexico. If in doubt, contact the New Mexico Department of Agriculture. Remember that it is illegal to apply any pesticide in a manner not in accordance with the directions and instructions given on the product label. Cranshaw, W. 2004. Garden insects of North America: The ultimate guide to backyard bugs. Princeton, NJ: Princeton University Press. Cranshaw, W. 1998. Pests of the West: Prevention and control for today's garden and small farm. Golden, CO: Fulcrum Publishing. Ellis, B.W., and Bradley, F.M. (Eds.). 1996. The organic gardener's handbook of natural insect and disease control: A complete problem-solving guide to keeping your garden and yard healthy without chemicals. Emmaus, PA: Rodale Books. Evans, A.V. 2007. National Wildlife Federation field guide to insects and spiders & related species of North America. New York: Sterli 1See NMSU Cooperative Extension Service Guide H-505: Mowing Your Lawn. http://aces.nmsu.edu/pubs/_h/h-505.pdf 2See NMSU Cooperative Extension Service Guide H-156: Tree Pruning Techniques. http://aces.nmsu.edu/pubs/_h/h-156.pdf To find more resources for your business, home, or family, visit the College of Agricultural, Consumer and Environmental Sciences on the World Wide Web at aces.nmsu.edu Contents of publications may be freely reproduced for educational purposes. All other rights reserved. For permission to use publications for other purposes, contact [email protected] or the authors listed on the publication. New Mexico State University is an equal opportunity/affirmative action employer and educator. NMSU and the U.S. Department of Agriculture cooperating. Printed and electronically distributed April 2011, Las Cruces, NM
Learn something new every day More Info... by email A diffusion barrier is usually a thin coating of material used to prevent diffusion. Diffusion occurs when molecules move from an area of high concentration to an area of low concentration so that an equal number occurs in both areas. Diffusion happens whether the molecules are in a gas, liquid or solid state, and can lead to the contamination of one product by another. A diffusion barrier is usually only micrometers thin, and is used to enhance the shelf life of metal-containing products by slowing their corruption from other products nearby. These types of barriers are used in a variety of commercial applications, so effective and inexpensive barriers are highly sought-after, especially by the electronics industry. Although oxygen and hydrogen gas diffusion barriers exist, the majority of diffusion barriers are metals. A good diffusion barrier has physical and chemical properties that vary depending on the metal components used to make the barrier. The thinner the diffusion barrier, and the more uniform the coating, the more effective the barrier. The metals in the barrier must be non-reactive to the materials around it, so they do not diffuse into and corrupt the metals the barrier is supposed to be protecting. Furthermore, the diffusion barrier must be able to strongly adhere to what it is protecting to provide a secure barrier that will completely prevent diffusion by any molecules. The different materials used to make diffusion barriers offer different advantages, and care must be taken to optimize the thickness, reactivity and adherence of the barrier. Metals differ in their reactivity and adherence, with some metals providing a high degree of non-reactivity but low adherence, or vice versa. Some barriers may have multiple layers to accommodate the need for both non-reactive and adhesive metals. Alternatively, a combination of metals, called alloys, may be used to form the barrier. A number of metals have been used in the creation of diffusion barriers, including aluminum, chromium, nickel, tungsten and manganese. Diffusion barriers have been commonly used in the manufacturing of electronics for decades. They are used to preserve the integrity of internal copper wiring from the silica insulation that surrounds it. This serves to prolong the lifespan of the electronic device by preventing circuit failure that would occur if the copper and silica came in contact. So far, the technology for creating and depositing diffusion barriers has allowed for increased speed of consumer electronics; however, new alloys and barrier deposition techniques are being investigated for use in new generations of electronics. One of our editors will review your suggestion and make changes if warranted. Note that depending on the number of suggestions we receive, this can take anywhere from a few hours to a few days. Thank you for helping to improve wiseGEEK!
In this post, we will discuss the differences between ArrayList and LinkedList in Java. Given a linked list containing 0’s, 1’s and 2’s, sort linked list by doing single traversal of it. This post provides an overview of some of the available techniques to implement a linked list in C++ programming language. Write an algorithm to compute the height of a binary tree with leaf nodes forming a circular doubly linked list where the left and right pointers of the leaf node will act as a previous and next pointer of circular doubly linked list respectively. For example, consider below binary tree. The leaf nodes are … Given a binary tree, print vertical sum of it. Assume, the left and right child of a node makes 45 degree angle with the parent. In this post, we will see how to detect cycle in a a linked list using Hashing and Floyd’s Cycle Detection Algorithm. Given a linked list, split it into two lists where each list contains alternating elements from the original list and then finally join them back together. Given a linked list, move its last node to front. Given a linked list, check if linked list is palindrome or not. Given a linked list, rearrange linked list nodes in specific way in linear time and constant space. The alternate positions in the output list should be filled with the nodes starting from the beginning and from the very end of the original list respectively. Given a linked list and two positive integers M and N, delete every N nodes in it after skipping M nodes. Write a function that takes two lists, each of which is sorted in increasing order, and merges the two together into one list which is in decreasing order and return it. In other words, merge two sorted linked lists from their end.
Microscopic fossils found in Western Australia show life on earth in its most primitive form, according to a new report. Close to three years ago, a research team from the University of Western Australia found fossils of tiny organisms in 3.4 billion-year-old sandstone in Strelley Pool in the dry Pilbara region, some 1,500 km north of Perth. After years of extensive analysis, there is now clear evidence that fossilized bacteria fed on sulfur, and not oxygen, in order to produce energy and grow, according to the report published in Nature Geoscience journal. “At last we have good solid evidence for life over 3.4 billion years ago,” said the report’s co-author Professor Martin Brasier from the University of Oxford Department of Earth Sciences. “It confirms there were bacteria at this time, living without oxygen.” The earth was very hot and volatile when these organisms lived. Volcanic activity was widespread and cloudy skies kept in the heat, pushing ocean temperatures up to around 40-50 degrees. Oxygen levels were very low and only increased millions of years later when algae and plant matter began producing the gas through respiration. But the primitive organisms whose existence was recorded in the sandstone of the oldest known beach on earth thrived in these conditions, living off sulfur found in soil and around hydrothermal vents and hot springs. Similar bacteria still exist today. Fossil or Fake? The Strelley Pool fossils are some of the best preserved ever found. But it can be very difficult to distinguish between genuine organic fossils and the natural mineralization process in rock structures. And thanks to technological advances over the last decade, convincing the scientific community of evidence of fossilized life has become even more difficult. In 2002, for example, the same Oxford department who published this latest report claimed microfossils found in the Apex cherts of the Pilbara region were not consistent with the shape and crystal structure of fossilized bacteria, despite having been widely considered so. Years of studying these new microfossils produced crucial results that seem to confirm they are indeed biological and were not formed through any mineralization process. Furthermore, pyrite crystals or fool’s gold associated with the imprints are very likely to have been produced as a by-product of sulfur metabolism. Life On Mars This research will undoubtedly be of interest to those seeking to answer the eternal question: are we alone? If life does exist outside the earth’s atmosphere, it is likely to be in the form of sulfur-eating microorganisms in low-oxygen environments. Professor Brasier says any proposed evidence of microfossils from elsewhere in our solar system will have to pass the same chemical and physical tests as those from Strelley Pool. “Could these sorts of things exist on Mars?” he asks. “It is just about conceivable.” Key Statistics - Fossils in Western Australia (source: Government of Western Australia) - The world’s oldest known fossil stromatolites, or layered rock structures, are located in Marble Bar in the Pilbara region. - The 3.54-billion-year-old stromatolites represent more geological periods throughout history than any other worldwide. - Organisms such as those found fossilized at Strelley Pool near Marble Bar were responsible for transforming the toxic greenhouses gasses of the earth’s earliest atmosphere into breathable oxygen.
Cecil Ingold was one of the world’s leading mycologists (scientists who study fungi)who was best known for his discovery of Ingoldian fungi and for his research into the physical mechanisms of spore dispersal. Ingoldian fungi are an important and ubiquitous group of aquatic fungi that play a key role in aquatic ecosystems by processing dead vegetation and recycling nutrients. His long-term botanical studies of aquatic fungi started in 1938. He analysed water samples he collected from a brook near his home in Cropston, Leicestershire. He firmly believed that botanists should collect and work with fresh material, gathered from the field. He despised the traditional dependence on preserved or pickled specimens. He combined acute powers of observation, whether on forays or peering down a microscope, with…
For most of us, a computer probably seems fast enough if it's able to run "LEGO Lord of the Rings" or a YouTube video of an English bulldog on a skateboard without slowing to a crawl. But for scientists who need to work on really complicated problems, the mere 158 billion calculations per second that a PC with an i7 processor can perform isn't nearly enough [sources: Peckham, ORNL, Kolawole]. That's why researchers are so excited about the Tennessee-based Oak Ridge National Laboratory (ORNL)'s new toy, the Cray Titan supercomputer. When it was unveiled in October 2012, the Titan claimed the title of world's fastest computer, which had been held by the IBM Sequoia Blue Gene/Q machine at the Lawrence Livermore National Laboratory in California for just six months [sources: Burt, Johnston]. How fast is the Titan? Its theoretical top speed is 27 petaflops, which doesn't sound that impressive unless you know that it means 27,000 trillion calculations per second [source: ORNL]. That's hundreds of thousands times faster than your top-of-the-line PC. Unlike your PC, though, Titan won't fit on a desktop; it occupies a space the size of a basketball court [source: Kolawole]. Titan's incredible speed makes it a fantastic tool for tackling really complicated problems that involve gigantic amounts of data. Researchers plan to use it to run detailed simulations of the Earth's climate, which may yield ideas on how to lessen global warming. They also may use it to help design super-efficient internal combustion engines and solar panels, and to run biological simulations that will help speed the testing of new drugs. On the pure science level, Titan could help scientists simulate the breaking of the bonds that hold molecules together, giving them new insights into one of the most important processes in nature [sources: ORNL, Kolawole]. But the Titan is important not just because it's incredibly fast, but because it pioneers a new sort of supercomputer design that could spawn a generation of even speedier machines. For years, scientists have achieved higher and higher speeds simply by building machines with thousands and thousands of central processing units, or CPUs, in them, and then breaking the calculations they want to perform into smaller pieces that could be parceled out to all of those CPUs [source: ORNL]. The drawback of that approach is all those CPU chips require enormous amounts of electricity. The Titan, however, pairs each of its 18,688 CPUs with a graphic processing unit, or GPU — the sort of chip used in hot-rod gaming PCs — to accelerate the computations. GPUs don't draw as much juice as CPUs, so the result is a machine that's faster than its predecessors but also a lot more energy efficient [sources: ORNL, Kolawole]. Researchers see the Titan as blazing the way toward exascale-class computers — that is, machines a thousand or more times as fast as the most powerful supercomputers today [sources: Kolawole, Goodwin and Zacharia].

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