1005 résultats pour "sées"
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Thermodynamics
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INTRODUCTION
Thermodynamics, field of physics that describes and correlates the physical properties of macroscopic systems of matter and energy.
Carnot EngineThe idealized Carnot engine was envisioned by the French physicist Nicolas Léonard Sadi Carnot, who lived during theearly 19th century. The Carnot engine is theoretically perfect, that is, it converts the maximum amount of energy intomechanical work. Carnot showed that the efficiency of any engine depends on the difference between the highest andlowest temperatures reached during one cycle. The greater the difference, the greater the efficiency. An automobileengine, for example, wou...
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Meteorología - ciencias de la naturaleza.
PluviómetroLas precipitaciones se miden con un pluviómetro como este, que se localiza en Tasmania (Australia) y forma parte de una estaciónmeteorológica.Cape Grim B.A.P.S./Simon Fraser/SciencePhoto Library/Photo Researchers, Inc. Las observaciones hechas a nivel del suelo son más numerosas que las realizadas a altitudes superiores. Incluyen la medición de la presión atmosférica, la temperatura, lahumedad, la dirección y velocidad del viento, la cantidad y altura de las nubes, la visibilidad y la...
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Confederation of Canada - Canadian History.
Québec conference seemed in many ways to give Macdonald the centralized union he wanted. The federal government would control banking, finance, defense,transportation, and commerce among the provinces. It would also have far greater powers of taxation than the provincial governments would have. In private,Macdonald predicted that the central government would be so strong that it would soon swallow up the provinces completely. Yet the Québec resolutions were vague or contradictory enough to give...
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Mental Retardation.
For example, measles, chicken pox, and whooping cough may lead to encephalitis and meningitis, which can damage the brain. Physical trauma to the brain can also cause mental retardation. Brain damage may result from accidental blows to the head, near drowning, severe child abuse, andchildhood exposure to such toxins as lead and mercury. Experts believe that poverty and a lack of stimulation during infancy and early childhood can be factors inmental retardation. Children raised in poor environmen...
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Pollination - biology.
rapidly as in cross-pollination, because one plant with a beneficial gene can transmit it only to its own offspring and not to other plants. Self-pollination evolved laterthan cross-pollination, and may have developed as a survival mechanism in harsh environments where pollinators were scarce. IV POLLEN TRANSFER Unlike animals, plants are literally rooted to the spot, and so cannot move to combine sex cells from different plants; for this reason, species have evolved effectivestrategies for ac...
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Computer.
which can activate computer commands in conjunction with voice recognition software. “Tablet” computers are being developed that will allow users to interact with theirscreens using a penlike device. E The Central Processing Unit Information from an input device or from the computer’s memory is communicated via the bus to the central processing unit (CPU), which is the part of the computerthat translates commands and runs programs. The CPU is a microprocessor chip—that is, a single piece of sil...
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Malawi - geographie.
Früchte, Gemüse und Erdnüsse sowie Getreide; exportiert werden vor allem Tabak, Tee, Zucker und Baumwolle. Fischfang und Fischverarbeitung dienen vorwiegend derEigenversorgung, entwickeln sich aber zu einem potentiellen Exportzweig. Die Fischindustrie hat ihren Hauptstandort in Nkhotakota am Westufer des Malawisees. Diejährliche Fangmenge liegt bei 59 595 Tonnen (2005). 6.2 Außenhandel und Währung Aufgrund seiner geographischen Lage ist Malawi beim Im- und Export auf Transportwege durch seine N...
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Jane Austen.
years later.) Mansfield Park is Jane Austen’s most ambitious novel—in length, in variety of characterization, and in the scope of its theme. It centers on the effects of upbringing on personal morality in three families—the middle-class Bertrams, the fashionable Crawfords, and the impoverished Prices. Austen has been praised for her presentation ofthe complex relations between the members of the families, but as in Sense and Sensibility, she frustrates the expectations of her readers that the...
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Magnetism
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INTRODUCTION
Magnetism, an aspect of electromagnetism, one of the fundamental forces of nature.
the French physicist Paul Langevin produced a theory regarding the temperature dependence of the magnetic properties of paramagnets (discussed below), which wasbased on the atomic structure of matter. This theory is an early example of the description of large-scale properties in terms of the properties of electrons and atoms.Langevin's theory was subsequently expanded by the French physicist Pierre Ernst Weiss, who postulated the existence of an internal, “molecular” magnetic field inmaterials...
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Temple (building)
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INTRODUCTION
Wat Phra Kaeo
Thailand has nearly 18,000 Buddhist temples, called wats, throughout the country.
colonnaded terraces connected by ramps. The surrounding area was planted with trees and flowers during Hatshepsut’sreign and for many years after.Gian Berto Vanni/Art Resource, NY In ancient Egypt, temples were grandiose, built of huge blocks and columns of stone. Often they were enlarged by successive rulers to form strung-out series of templeparts, as in the gigantic Temple of Amon (circa 1550-1070 BC) at Al Karnak. The Nile cliffs were used as settings for temples, such as the massive mortuar...
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Biodiversidad - ciencias de la naturaleza.
Las áreas ricas en especies endémicas pueden ser lugares de especiación activa o de refugio de especies muy antiguas; sea cual sea su interés teórico, es importante parala gestión práctica de la biodiversidad identificar estas áreas discretas con proporciones elevadas de endemismos. Por definición, las especies endémicas de un lugardeterminado no se encuentran en ningún otro. Cuanto menor es el área de endemismo, mayor es el riesgo de que las especies endémicas sufran cambios de población deorig...
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Stroke.
IV DIAGNOSIS The symptoms typical of a stroke can also be caused by other conditions, including brain tumors, various infections, and overdoses of certain drugs. A patient that hasstrokelike symptoms may undergo a battery of imaging techniques to rule out other medical problems and confirm that a stroke has occurred. The key imagingtechnique used in diagnosing strokes is computed tomography (also known as CT or CAT scanning), which employs X rays to obtain images of the internal structures oft...
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Suicide.
C Sociological Theories Most social scientists believe that a society’s structure and values can influence suicide rates. French sociologist Émile Durkheim argued that suicide rates are related tosocial integration —that is, the degree to which an individual feels part of a larger group. Durkheim found suicide was more likely when a person lacked social bonds or had relationships disrupted through a sudden change in status, such as unemployment. As one example of the significance of social bond...
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Himalayas - geography.
result of deforestation the habitat of most of the wildlife has been destroyed. They are now restricted to special protected areas such as the Jaldapara and Kazirangasanctuaries in India ( see Kaziranga National Park) and the Chitawan preserve in Nepal. There are few animals in the Middle Himalayas because of extensive deforestation. In the Great Himalayas musk deer, wild goats, sheep, wolves, and snow leopards are found. The existence of the Abominable Snowman or Yeti has beenreported by highla...
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Digestive System.
The stomach, located in the upper abdomen just below the diaphragm, is a saclike structure with strong, muscular walls. The stomach can expand significantly to storeall the food from a meal for both mechanical and chemical processing. The stomach contracts about three times per minute, churning the food and mixing it with gastricjuice. This fluid, secreted by thousands of gastric glands in the lining of the stomach, consists of water, hydrochloric acid, an enzyme called pepsin, and mucin (the...
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Henry VIII
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INTRODUCTION
Henry VIII (1491-1547), king of England (1509-1547), the image of the Renaissance king as immortalized by German artist Hans Holbein, who painted him hands on
hips, legs astride, exuding confidence and power.
that was completed by 1540. The crown then took possession of all their property, paying small pensions to the approximately 10,000 monks and nuns who weredeprived of their homes. In a reversal of roles, many towns were forced to assist the same people who had once provided charity to the less fortunate. To pay for hiscontinued wars, Henry sold the former monastic lands to nobles and gentry, who thereby gained an interest in the success of Henry’s reformation and becamedependent upon the king. T...
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Henry VIII.
that was completed by 1540. The crown then took possession of all their property, paying small pensions to the approximately 10,000 monks and nuns who weredeprived of their homes. In a reversal of roles, many towns were forced to assist the same people who had once provided charity to the less fortunate. To pay for hiscontinued wars, Henry sold the former monastic lands to nobles and gentry, who thereby gained an interest in the success of Henry’s reformation and becamedependent upon the king. T...
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Henry VIII .
that was completed by 1540. The crown then took possession of all their property, paying small pensions to the approximately 10,000 monks and nuns who weredeprived of their homes. In a reversal of roles, many towns were forced to assist the same people who had once provided charity to the less fortunate. To pay for hiscontinued wars, Henry sold the former monastic lands to nobles and gentry, who thereby gained an interest in the success of Henry’s reformation and becamedependent upon the king. T...
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Cuban Missile Crisis.
inspect ships to determine whether they were carrying weapons. Kennedy warned that if Khrushchev fired missiles from Cuba, the result would be “a full retaliatoryresponse upon the Soviet Union.” Because international law defines a blockade as an act of war, Kennedy and his advisers decided to refer to the blockade as a quarantine. The United States wassupported by other members of the Organization of American States, an organization of nations in the western hemisphere that seek to cooperate on...
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Cuban Missile Crisis - U.
inspect ships to determine whether they were carrying weapons. Kennedy warned that if Khrushchev fired missiles from Cuba, the result would be “a full retaliatoryresponse upon the Soviet Union.” Because international law defines a blockade as an act of war, Kennedy and his advisers decided to refer to the blockade as a quarantine. The United States wassupported by other members of the Organization of American States, an organization of nations in the western hemisphere that seek to cooperate on...
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Giant Panda - biology.
In 2007 conservationists announced that a parasitic roundworm was responsible for a significant number of the panda deaths reported in the wild since 1990. Theparasite Baylisascaris schroederi causes the disease visceral larval migrans, which results in bleeding in the lungs, the liver, and the intestines, and can also affect the brain. It is not known if other recent pandas deaths were caused by the same parasite or by a different contagious disease. Loss of habitat from deforestation is forc...
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Mechanics
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INTRODUCTION
Mechanics, branch of physics concerning the motions of objects and their response to forces.
Components of VelocityNeglecting air resistance, a ball thrown into the air at an angle will travel in a parabolic path. The velocity of the ball (V)has independent vertical (V) and horizontal (H) components; the horizontal component stays the same the entire time theball is in the air, while the vertical component, the only component affected by gravity, changes continuously while theball is aloft.© Microsoft Corporation. All Rights Reserved. To understand why and how objects accelerate, force...
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Igneous Rock.
As a magma cools, the first crystals to form will be of minerals that become solid at relatively high temperatures (usually olivine and a type of feldspar known asanorthite). The composition of these early-formed mineral crystals will be different from the initial composition of the magma. Consequently, as these growing crystalstake certain elements out of the magma in certain proportions, the composition of the remaining liquid changes. This process is known as magmatic differentiation.Sometime...
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Jane Austen
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INTRODUCTION
Jane Austen
English author Jane Austen crafted satirical romances set within the confines of upper-middle-class English society.
up their personal pride and prejudices before they can enter into a happy relationship together. As do Austen’s earlier writings, Pride and Prejudice displays the themes of appearance versus reality, and impulse versus deliberation. Elizabeth, trusting her own impulses, makes a mistake about Darcy and his apparent arrogance that deliberation and further experience eventually cause her to correct. Of Elizabeth, Austenwrote: “I must confess that I think her as delightful a creature as ever appea...
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Police.
body. In larger agencies, executive officers may be selected through a civil service or merit system, after moving through the ranks from patrol officer to sergeant,lieutenant, captain, and (in still larger agencies) deputy or assistant chief. At the county level, the head of the agency usually holds the title sheriff. The sheriff is almost always elected and has the power to appoint deputies. Sheriffs'departments often provide law enforcement services for unincorporated areas of counties and ar...
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Richard Wagner
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INTRODUCTION
Richard Wagner (1813-1883), German composer, conductor, and essayist, one of the most influential cultural figures of the 19th century.
May 1864 he was summoned to Munich by the 18-year-old King Ludwig II of Bavaria, who settled Wagner's debts, paid him a generous allowance, and provided himwith housing. Wagner was soon joined in his new home by Cosima von Bülow, Liszt’s daughter and the wife of German conductor and pianist Hans von Bülow. Wagnerand Cosima began a relationship that produced three children before the dissolution of the Bülows' marriage in 1870. Mounting hostility toward Wagner by members ofLudwig’s court resulted...
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D-Day Invasion.
The Allied planners focused on the beaches around Caen and the Cotentin Peninsula in northern France rather than those of Calais, even though it meant the forcewould be crossing at a wider part of the English Channel. That disadvantage was far outweighed by what the site offered: comparatively scanty defensive fortificationsand beachhead ideally suited for successful exits. The clincher was an isolated battlefield that the Germans would have difficulty reinforcing. The date was set for May 1, 19...
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World Wide Web.
browser does not display the URL for the user. Instead, to indicate that an item is selectable, the browser changes the color of the item on the screen and keeps theURL associated with the link hidden. When a user clicks on an item that corresponds to a selectable link, the browser consults the hidden information to find theappropriate URL, which the browser then follows to the selected page. Because a link can point to any page in the Web, the links are known as hyperlinks. See also Hypermedia...
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Hardware (computer).
Magnetic tape drives use magnetic tape similar to the tape used in VCR cassettes. Tape drives have a very slow read/write time, but have a very high capacity; in fact,their capacity is second only to hard disk drives. Tape drives are mainly used to back up data. Compact disc drives store information on pits burned into the surface of a disc of reflective material ( see CD-ROM). CD-ROMs can store up to 737 megabytes (MB) of data. A Compact Disc-Recordable (CD-R) or Compact Disc-ReWritable (CD-RW)...
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Uranus (planet) - astronomy.
V COMPOSITION AND STRUCTURE A Interior of Uranus Uranus contains mostly rock and water, with hydrogen and helium (and trace amounts of methane) in its dense atmosphere. Astronomers believe that Uranus, likeNeptune, formed from the same material—principally frozen water and rock—that composes most of the planet’s moons. As the planet grew, pressures andtemperatures in the planet’s interior increased, heating the planet’s frozen water into a hot liquid. Uranus probably has a relatively small roc...
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Rio de Janeiro (city) - geography.
were coronated; and Our Lady of Candelária Church, thought by some to be the city’s most beautiful church. Another building of interest is the Imperial Palace, located several blocks west of Santos Dumont Airport. Originally constructed as Brazil’s colonial governor’s capitol in1743, it was converted to the royal palace during the city’s period as an imperial capital. It has recently been restored and now houses a cultural center. Otherimpressive 19th-century palaces include Itamaraty and Catete...
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Water Pollution.
Cryptosporidium in the water supply of Milwaukee, Wisconsin, sickened more than 400,000 people and killed more than 100. H Thermal Pollution Water is often drawn from rivers, lakes, or the ocean for use as a coolant in factories and power plants. The water is usually returned to the source warmer than when itwas taken. Even small temperature changes in a body of water can drive away the fish and other species that were originally present, and attract other species in placeof them. Thermal pol...
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Calvin Coolidge.
By 1923 President Harding was faced with a number of difficulties. A business depression, which had begun in 1922, continued. In addition, the Republican majorities inboth houses of Congress were reduced in the election of 1922, and a discontented farm bloc of Western Republican senators threatened to destroy the Senate majorityby allying with the Democrats. Finally, it was rumored that major scandals involving Harding's friends were about to break. The rumors were soon proved accurate. The dire...
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Calvin Coolidge
By 1923 President Harding was faced with a number of difficulties. A business depression, which had begun in 1922, continued. In addition, the Republican majorities inboth houses of Congress were reduced in the election of 1922, and a discontented farm bloc of Western Republican senators threatened to destroy the Senate majorityby allying with the Democrats. Finally, it was rumored that major scandals involving Harding's friends were about to break. The rumors were soon proved accurate. The dire...
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John Macdonald.
dissolution of the existing Union. The Atlantic colonies, which consisted of Nova Scotia, Prince Edward Island, New Brunswick, and Newfoundland, were considering the question of their own union andplanned to meet at Charlottetown, Prince Edward Island, on September 1, 1864. Macdonald saw his opportunity and secured an invitation for the Canadians to attend.The delegates of the Atlantic colonies put off their own discussion until they had heard the Canadians. Macdonald spoke of the advantages in...
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John Macdonald - Canadian History.
dissolution of the existing Union. The Atlantic colonies, which consisted of Nova Scotia, Prince Edward Island, New Brunswick, and Newfoundland, were considering the question of their own union andplanned to meet at Charlottetown, Prince Edward Island, on September 1, 1864. Macdonald saw his opportunity and secured an invitation for the Canadians to attend.The delegates of the Atlantic colonies put off their own discussion until they had heard the Canadians. Macdonald spoke of the advantages in...
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John Macdonald - Canadian History.
dissolution of the existing Union. The Atlantic colonies, which consisted of Nova Scotia, Prince Edward Island, New Brunswick, and Newfoundland, were considering the question of their own union andplanned to meet at Charlottetown, Prince Edward Island, on September 1, 1864. Macdonald saw his opportunity and secured an invitation for the Canadians to attend.The delegates of the Atlantic colonies put off their own discussion until they had heard the Canadians. Macdonald spoke of the advantages in...
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San Antonio (city, Texas) - geography.
The SBC Center is the home venue for the San Antonio Spurs of the National Basketball Association (NBA) and the San Antonio Silver Stars of the Women's NationalBasketball Association (WNBA). The dome also serves as the site for the Alamo Bowl, an annual post-season college football game. Large themed amusement parks inthe San Antonio area are Fiesta Texas and Sea World of Texas. San Antonio’s major annual event is the Fiesta, a ten-day celebration in late April with carnivals, ethnic feasts, art...
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Stress (psychology).
blood flow is diverted from the internal organs and skin to the brain and muscles. Breathing speeds up, the pupils dilate, and perspiration increases. This reaction issometimes called the fight-or-flight response because it energizes the body to either confront or flee from a threat. Another part of the stress response involves the hypothalamus and the pituitary gland, parts of the brain that are important in regulating hormones and many otherbodily functions. In times of stress, the hypothal...
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Fruit - biology.
from a flower with several pistils. The ovary may have a single compartment, or carpel, which houses the ovule or ovules. Or the ovary may consist of two or morecarpels, each of which may contain one or more ovules. A drupe develops from an ovary with a single carpel and is characterized by an edible exocarp and mesocarp and an inedible, hard endocarp, or pit that encloses asingle seed. Cherries, peaches, apricots, and plums are examples of drupes. Almonds also are classified as drupes, but in a...
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Neptune (planet) - astronomy.
The gaseous atmosphere of Neptune contains hydrogen, helium, and about 3 percent methane. It extends about 5,000 km (about 3,000 mi) above the planet’s ocean.Light reflected from Neptune’s deep atmosphere is blue, because the atmospheric methane absorbs red and orange light but scatters blue light. In 1998 astronomersalso identified molecules of methyl in Neptune’s atmosphere. Methyl molecules each contain one carbon atom and three hydrogen atoms. Methyl molecules are knownas hydrocarbon radical...
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Declaration of Independence.
communication networks to publicize British actions and encourage demonstrations of defiance. Soon these committees and some colonial legislatures issued a call for anall-colony congress to discuss other appropriate responses to Britain’s actions. The Continental Congress first met in Philadelphia from September to the end of October1774. This body did not plan for war; instead, it debated the extent to which the colonies should carry their resistance to Great Britain. The First Continental Cong...
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Declaration of Independence - U.
communication networks to publicize British actions and encourage demonstrations of defiance. Soon these committees and some colonial legislatures issued a call for anall-colony congress to discuss other appropriate responses to Britain’s actions. The Continental Congress first met in Philadelphia from September to the end of October1774. This body did not plan for war; instead, it debated the extent to which the colonies should carry their resistance to Great Britain. The First Continental Cong...
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Scramble for Africa.
additional territorial grabs. The most significant of these rules stated that colonial powers were obligated to notify each other when they claimed African territory.Further, subsequent “effective occupation” of the claimed area was necessary for the claim to remain valid. Through it all, as Europeans negotiated their rights toAfrican territory, not a single African was present. Once the conference was over, it was clear that a European Scramble for African territories was underway. Southern Afr...
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National Socialism .
VII THE PARTY IN THE REICHSTAG The movement grew rapidly, recruiting thousands of discharged civil servants, ruined shopkeepers and small-business owners, impoverished farmers, workersdisillusioned with the Socialist and Communist parties, and a host of frustrated and embittered young people of all classes, brought up in the postwar years and withouthope of personal economic security. In the Reichstag elections of 1930 the National Socialists polled almost 6.5 million votes (more than 18 perce...
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Labor Unions in Canada - Canadian History.
job. Before collective bargaining begins, workers elect a bargaining committee. The bargaining committee determines the workers’ demands and strategy innegotiations with the employer. Local unions usually are part of national or international unions. These national and international unions employ a staff for organizing workers at the local level, doingresearch, educating union members about labor and political matters, and working with local union leaders. Unions hold regular conventions of dele...
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Tanzania - country.
The population of Tanzania (2008 estimate) is 40,213,162, giving the country an overall population density of 45 persons per sq km (118 per sq mi). Yet the populationdistribution is irregular, with high densities found near fertile soils around Kilimanjaro and the shores of Lake Malawi, and comparatively low density throughout much ofthe interior of the country. In the late 1960s and 1970s the Tanzanian government resettled most of the rural population in collective farming villages as part of i...
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Atlantic Slave Trade.
members of the planters’ society. Through most of the years of the Atlantic trade, prices for Africans remained favorable in relation to the price of the crops theyproduced. They were, thus, the best economic solution for plantation owners seeking inexpensive labor. The Atlantic slave trade began as a trickle in the 1440s and grew slowly through the 17th century. By 1700, 25,000 slaves, on average, were crossing the Atlantic everyyear. After 1700 the trade grew much more rapidly to a peak in the...
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Popular Music
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INTRODUCTION
Satchmo Sings "Back O' Town Blues"
One of the founders of instrumental jazz music, American Louis Armstrong, known as Satchmo, also profoundly influenced
vocal jazz and popular song.
disseminating popular music until the 1920s remained printed sheet music. By the late 19th century, the music-publishing business was centralized in New York City,particularly in an area of lower Manhattan called Tin Pan Alley. “After the Ball” (1892) by Charles K. Harris, the first popular song to sell 1 million copies—in this case, ofsheet music—inspired rapid growth in the music-publishing industry. Composers were hired to rapidly produce popular songs by the dozens, and the techniques ofFost...
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Indian Literature
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INTRODUCTION
Arundhati Roy's The God of Small Things
Indian author Arundhati Roy poses with a copy of her acclaimed first novel, The God of Small Things (1997).
Mathura BuddhaMany of the earliest texts of Indian literature were religious writings of Buddhism. This Buddha figure carved out ofsandstone is from Mathura, a city in northern India that was at the center of Buddhist sculptural activity from the 2ndcentury bc to the 6th century ad.Angelo Hornak/Corbis The sacred Vedas were composed in Old Sanskrit by Aryan poet-seers between about 1500 BC and about 1000 BC. The Vedas are compilations of two major literary forms: hymns of praise to nature deit...