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A 2007 eruptive column at Mount Etna producing volcanic ash, pumice and lava bombs Santa Ana Volcano, El Salvador, a close up aerial view of the nested summit calderas and craters, along with the crater lake as seen from a United States Air Force C-130 Hercules flying above El Salvador. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature; the melted particles then adhere to the turbine blades and alter their shape, disrupting the operation of the turbine. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere (or troposphere); however, they also absorb heat radiated up from the Earth, thereby warming the upper atmosphere (or stratosphere). Etymology Plate tectonics Divergent plate boundaries "Hotspots" Related:  Common connotations of RED

Christmas While the birth year of Jesus is estimated among modern historians to have been between 7 and 2 BC, the exact month and day of his birth are unknown.[18][19] His birth is mentioned in two of the four canonical gospels. By the early-to-mid 4th century, the Western Christian Church had placed Christmas on December 25,[20] a date later adopted in the East,[21][22] although some churches celebrate on the December 25 of the older Julian calendar, which corresponds to January in the modern-day Gregorian calendar. The date of Christmas may have initially been chosen to correspond with the day exactly nine months after early Christians believed Jesus to have been conceived,[23] or with one or more ancient polytheistic festivals that occurred near southern solstice (i.e., the Roman winter solstice); a further solar connection has been suggested because of a biblical verse[a] identifying Jesus as the "Sun of righteousness".[23][24][25][26][27] Etymology Other names History Dies Natalis Solis Invicti

Convergent boundary Descriptions[edit] The nature of a convergent boundary depends on the type of plates that are colliding. Where a dense oceanic plate collides with a less-dense continental plate, the oceanic plate is typically thrust underneath because of the greater buoyancy of the continental lithosphere, forming a subduction zone. Where two continental plates collide the plates either buckle and compress or (in some cases) one plate delves called subduction, under the other. When two plates with oceanic crust converge, they typically create an island arc as one plate is subducted below the other. Not all plate boundaries are easily defined. Convergent margins[edit] A subduction zone is formed at a convergent plate boundary when one or both of the tectonic plates is composed of oceanic crust. An oceanic trench is found where the denser plate is subducted underneath the other plate. Some convergent margins have zones of active seafloor spreading behind the island arc, known as back-arc basins.

Republican Party (United States) History Founding and 19th century The first official party convention was held on July 6, 1854, in Jackson, Michigan. The Republicans' initial base was in the Northeast and the upper Midwest. Early Republican ideology was reflected in the 1856 slogan "free labor, free land, free men", which had been coined by Salmon P. The GOP supported business generally, hard money (i.e., the gold standard), high tariffs to promote economic growth, high wages and high profits, generous pensions for Union veterans, and (after 1893) the annexation of Hawaii. Nevertheless, by 1890 the Republicans had agreed to the Sherman Antitrust Act and the Interstate Commerce Commission in response to complaints from owners of small businesses and farmers. After the two terms of Democrat Grover Cleveland, the election of William McKinley in 1896 is widely seen as a resurgence of Republican dominance and is sometimes cited as a realigning election. 20th century Warren G. The New Deal coalition of Democrat Franklin D.

Tectonic Plates The edges of these plates, where they move against each other, are sites of intense geologic activity, such as earthquakes, volcanoes, and mountain building. Plate tectonics is a relatively new theory and it wasn't until the 1960's that Geologists, with the help of ocean surveys, began to understand what goes on beneath our feet. Where is the Evidence for Plate Tectonics? It is hard to imagine that these great big solid slabs of rock could wander around the globe. Scientists needed a clue as to how the continents drifted. Click here for the Scotland story Picture the following in your mind: You have a nine piece jigsaw (now there's a challenge). What do you think will happen to the puzzle? Now let's think back to our plates being created at the mid-ocean ridges, it seems to be a good idea but if this is the only type of plate movement then the world would get bigger and bigger. The floor of the Easter Pacific is moving towards South America at a rate of 9 centimetres per year.

Error The word error entails different meanings and usages relative to how it is conceptually applied. The concrete meaning of the Latin word "error" is "wandering" or "straying". Unlike an illusion, an error or a mistake can sometimes be dispelled through knowledge (knowing that one is looking at a mirage and not at real water does not make the mirage disappear). For example, a person who uses too much of an ingredient in a recipe and has a failed product can learn the right amount to use and avoid repeating the mistake. However, some errors can occur even when individuals have the required knowledge to perform a task correctly. Human behavior[edit] One reference differentiates between "error" and "mistake" as follows: An 'error' is a deviation from accuracy or correctness. Oral and written language[edit] An individual language user's deviations from standard language norms in grammar, syntax, pronunciation and punctuation are sometimes referred to as errors. Gaffe [edit] Medicine[edit]

Earth Floor: Plate Tectonics Convergent Boundaries Places where plates crash or crunch together are called convergent boundaries. Plates only move a few centimeters each year, so collisions are very slow and last millions of years. Even though plate collisions take a long time, lots of interesting things happen. For example, in the drawing above, an oceanic plate has crashed into a continental plate. Are They Dangerous Places to Live? On the other hand, earthquakes and volcanoes occurring in areas where few people live harm no one. Back | Next Courage Courage is the choice and willingness to confront agony, pain, danger, uncertainty or intimidation. Physical courage is courage in the face of physical pain, hardship, death or threat of death, while moral courage is the ability to act rightly in the face of popular opposition, shame, scandal or discouragement. In some traditions, fortitude holds approximately the same meaning. In the Western tradition, notable thoughts on courage have come from philosophers such as Aristotle, Aquinas and Kierkegaard; in the Eastern tradition, some thoughts on courage were offered by the Tao Te Ching. More recently, courage has been explored by the discipline of psychology. Theories of courage[edit] Western antiquity and the Middle Ages[edit] Ancient Greece[edit] An early Greek philosopher, Plato (c. 428 BCE – c. 348 BCE),[1] set the groundwork for how courage would be viewed to future philosophers. Ancient Rome[edit] Medieval philosophy[edit] According to Thomas Aquinas,[10] Christianity[edit] Modernity[edit]

World Physical MapMaker Kit About This MapMaker Kit The World Physical MapMaker Kit maps includes a map without country boundaries, city names, and other political features. For a world map with country boundaries see the World Political MapMaker Kit. Download, print, and assemble maps of the physical world in a variety of sizes. The mega map occupies a large wall, or can be used on the floor. Download the MapMaker Kit Download the maps from the carousel above, or from the links below. Blood Human blood fractioned by centrifugation. Plasma (upper layer), buffy coat (middle, white colored layer) and erytrocite layer (bottom) can be seen. Blood circulation: Red = oxygenated Blue = deoxygenated Human blood magnified 600 times Frog blood magnified 600 times Fish blood magnified 600 times In vertebrates, it is composed of blood cells suspended in blood plasma. Vertebrate blood is bright red when its hemoglobin is oxygenated. Jawed vertebrates have an adaptive immune system, based largely on white blood cells. Medical terms related to blood often begin with hemo- or hemato- (also spelled haemo- and haemato-) from the Greek word αἷμα (haima) for "blood". Functions Haemoglobin, a globular protein green = haem groups red & blue = protein subunits Heme Blood performs many important functions within the body including: Constituents of human blood Illustration depicting formed elements of blood. Two tubes of EDTA-anticoagulated blood. Cells One microliter of blood contains: Plasma Physiology

World Political MapMaker Kit About This MapMaker Kit The World Political MapMaker Kit maps include country boundaries, city names, and other political features. For a world map without country boundaries see the World Physical MapMaker Kit. Download, print, and assemble maps of the political world in a variety of sizes. Watch the tutorial video above to get started. Then download each piece of the MapMaker Kit as a PDF file. The mega map occupies a large wall, or can be used on the floor. Download the MapMaker Kit Download the maps from the carousel above, or from the links below. Risk Risk is the potential of losing something of value, weighed against the potential to gain something of value. Values (such as physical health, social status, emotional well being or financial wealth) can be gained or lost when taking risk resulting from a given action, activity and/or inaction, foreseen or unforeseen. Risk can also be defined as the intentional interaction with uncertainty. Definitions[edit] Firefighters at work Risk can be defined in a variety of ways. Basic definitions[edit] The probability of something happening multiplied by the resulting cost or benefit if it does. International Organization for Standardization[edit] The ISO 31000 (2009) / ISO Guide 73:2002 definition of risk is the 'effect of uncertainty on objectives'. Other[edit] The many inconsistent and ambiguous meanings attached to "risk" lead to widespread confusion and also mean that very different approaches to risk management are taken in different fields.[2] For example:[3] History[edit] Practice areas[edit]

Injury The knee of a patient is examined with help of radiography after an injury. An injury is damage to a biological organism caused by physical harm.[1] Major trauma is injury that can potentially lead to serious outcomes. Classification[edit] The United States Bureau of Labor Statistics developed the Occupational Injury and Illness Classification System (OIICS). Under this system injuries are classified by nature,part of body affected,source and secondary source, andevent or exposure. The OIICS was first published in 1992 and has been updated several times since.[2] The World Health Organization developed the International Classification of External Causes of Injury (ICECI). mechanism of injury,objects/substances producing injury,place of occurrence,activity when injured,the role of human intent, and additional modules. The Orchard Sports Injury Classification System (OSICS) is used to classify injuries to enable research into specific sports injuries.[4] By ultimate cause[edit] By modality[edit]

Masculinity Masculinity is a set of qualities, characteristics or roles generally considered typical of, or appropriate to, a man. It can have degrees of comparison: "more masculine", "most masculine'". The opposite can be expressed by terms such as "unmanly" or epicene.[1] A near-synonym of masculinity is virility (from Latin vir, man). Academic study of masculinity underwent a massive expansion of interest in the late 1980s and early 1990s, with courses in the United States dealing with masculinity rising from 30 to over 300.[4] This has led to the investigation of the intersection of masculinity with other axes of social discrimination and also to the use of concepts from other fields – such as feminism's model of the social construct of gender.[5] Nature versus nurture[edit] Hegemonic masculinity[edit] Direct competition of physical skill and strength is a feature of masculinity which appears in some form in virtually every culture on Earth. Critics of masculinity[edit] Western trends[edit]