1174 résultats pour "two"

• Ecology.

  an input of nutrients exceeding the capability of the ecosystem to process them. Nutrients eroded and leached from agricultural lands, along with sewage and industrialwastes accumulated from urban areas, all drain into streams, rivers, lakes, and estuaries. These pollutants destroy plants and animals that cannot tolerate theirpresence or the changed environmental conditions caused by them; at the same time they favor a few organisms more tolerant to changed conditions. Thus,precipitation filled...

• Ecology - biology.

  an input of nutrients exceeding the capability of the ecosystem to process them. Nutrients eroded and leached from agricultural lands, along with sewage and industrialwastes accumulated from urban areas, all drain into streams, rivers, lakes, and estuaries. These pollutants destroy plants and animals that cannot tolerate theirpresence or the changed environmental conditions caused by them; at the same time they favor a few organisms more tolerant to changed conditions. Thus,precipitation filled...

• Franklin Pierce.

  At the end of the war, Pierce returned home to his wife and six-year-old son. His law partnership had been dissolved, and he took a new partner. The new firm, like theold one, was highly successful. D Elder Statesman Pierce was by nature a politician. Although still in his early forties, as a retired U.S. senator he became New Hampshire's elder statesman and head of a group of lawyer-politicians called the Concord Clique, or the Regency. The group controlled the state's Democratic Party. Pierce...

• Franklin Pierce

  At the end of the war, Pierce returned home to his wife and six-year-old son. His law partnership had been dissolved, and he took a new partner. The new firm, like theold one, was highly successful. D Elder Statesman Pierce was by nature a politician. Although still in his early forties, as a retired U.S. senator he became New Hampshire's elder statesman and head of a group of lawyer-politicians called the Concord Clique, or the Regency. The group controlled the state's Democratic Party. Pierce...

• Liberia - country.

  West Atlantic, or Kwa linguistic groups. D Education Education is free and compulsory for children between the ages of 6 and 15. However, a scarcity of educational facilities means that few Liberians progress beyondprimary school. Almost all children of primary school-age attend school, but the figure drops to 23 percent (1999–2000) for secondary school-age children. Just 60percent of the population was literate in 2005. Higher education is provided by the University of Liberia (1862), in Monro...

• Glacier.

  covered. In spring the snow cover begins to melt in the lower reaches, exposing the ice surface. As temperatures increase, the melting moves up the glacier. Thesnowline is the highest position the melting reaches during the year. Firn is old granular snow. The firn limit may not exactly coincide with the annual snowline since insome years rapid melting leaves behind firn patches below the snowline. Some glaciers exhibit features called ice streams and icefalls. Ice streams are valley glaciers th...

• Musical I INTRODUCTION George Gershwin American pianist, songwriter, and composer George Gershwin was one of the most important figures in popular song in the 1920s and 1930s.

  C Extravaganzas Another predecessor of musical comedy, the extravaganza, evolved soon after the American Civil War (1861-1865) from traditional English pantomime. Extravaganzaswere typically based on fairy tales and Mother Goose. They introduced some of the elements—songs, dances, and comedy combined with spectacular stage sets andeffects—that American musical comedy later became known for. The first and most famous extravaganza show was The Black Crook (1866), often described as America’s fi...

• Winston Churchill I INTRODUCTION Winston Churchill (1874-1965), British politician and prime minister of the United Kingdom (1940-1945, 1951-1955), widely regarded as the greatest British leader of the 20th century.

  sufficient tools to break the stalemate on the western front and he worked on developing armored fighting vehicles (tanks) to break the deadlock and end theslaughter. As the lines hardened on the western front, Churchill focused on a campaign to force open the Dardanelles Strait, controlled by the Ottoman Empire, to give the Allies adirect route to Russia through the Black Sea. Such a move would bring much-needed supplies to the Russian armies and eliminate the Ottomans from the war. Whenthe nav...

• Winston Churchill.

  sufficient tools to break the stalemate on the western front and he worked on developing armored fighting vehicles (tanks) to break the deadlock and end theslaughter. As the lines hardened on the western front, Churchill focused on a campaign to force open the Dardanelles Strait, controlled by the Ottoman Empire, to give the Allies adirect route to Russia through the Black Sea. Such a move would bring much-needed supplies to the Russian armies and eliminate the Ottomans from the war. Whenthe nav...

• Winston Churchill .

  sufficient tools to break the stalemate on the western front and he worked on developing armored fighting vehicles (tanks) to break the deadlock and end theslaughter. As the lines hardened on the western front, Churchill focused on a campaign to force open the Dardanelles Strait, controlled by the Ottoman Empire, to give the Allies adirect route to Russia through the Black Sea. Such a move would bring much-needed supplies to the Russian armies and eliminate the Ottomans from the war. Whenthe nav...

• Ear. I INTRODUCTION Ear, organ of hearing and balance. Only vertebrates, or animals

  line or rotates in any direction. Each canal also contains sensory areas with sensory hair cells that project into a cone-shaped cap of gelatin. Two of the semicircularcanals are in a vertical position and are used to detect vertical movement, such as jumping or falling. The third canal is horizontal and detects horizontal movement,such as turning or spinning. The action of the canals depends on the inertia of the fluid inside. When the motion of the body changes, the fluid lags behind, causing...

• Birth Control.

  without a prescription and used alone or with a condom, diaphragm, or cervical cap. Spermicides used alone must be inserted deep into the vagina before each act ofintercourse and a woman should not douche for six to eight hours after intercourse. With typical use, spermicides used alone are effective in preventing pregnancyabout 74 percent of the time. They may cause an allergic reaction such as irritation of the vagina or penis. B Intrauterine Device The intrauterine device (IUD) is a small pl...

• Moon - astronomy.

  B Volcanic Features Maria, domes, rilles, and a few craters display indisputable characteristics of volcanic origin. Maria are plains of dark-colored rock that cover approximately 40 percent ofthe Moon's visible hemisphere. The maria formed when molten rock erupted onto the surface and solidified between 3.16 billion and 3.96 billion years ago. This rockresembles terrestrial basalt, a volcanic rock type widely distributed on Earth, but the rock that formed the maria has a higher iron content an...

• Camping.

  Commercial campgrounds serve as campsites for RV and car campers on the outskirts of national and state parks and along highways throughout North America.Owners of commercial campgrounds charge campers on a daily or weekly basis, and provide campsites equipped with hookups for electricity and water. They may alsoprovide such amenities as showers, laundry facilities, or a swimming pool. Many commercial campgrounds belong to a club or network that allows its members toreserve campsites in advance....

• Armenia (country) - country.

  because of ethnic tension brought on by a secessionist conflict in Nagorno-Karabakh, a region inhabited predominantly by Armenians in western Azerbaijan. In thereverse direction, many Armenian refugees entered Armenia from Azerbaijan during the conflict. Armenia’s official state language is Armenian, an Indo-European language with no surviving close relatives. It has a unique 38-letter alphabet that dates from the early5th century. Of its many spoken dialects, the most important are Eastern or Y...

• Philadelphia (city, Pennsylvania) - geography.

  national trend of migration from eastern cities to the warmer climate of the Sun Belt. Whereas in 1950 Philadelphia contained more than 2 million people and ranked as the third largest city in America, the city's population plunged to 1,517,550 by 2000.In 2006, the city's population was estimated at 1,448,394. While the city proper was decreasing in population, the metropolitan area centered on Philadelphia grew. In 2006 the region had 6.2 million inhabitants. Philadelphiaranked as the nation’s...

• National Parks and Preserves.

  Some ibex raised in Italy’s 700 sq km (220 sq mi) Gran Paradiso National Park (1922) were transferred to aid herd restoration elsewhere in the country. Switzerlandreturned lynx to Swiss National Park to keep red deer populations in check. The growth of national parks also enabled many European countries to restore forests thathad given way to industrialization by the early 20th century. Africa’s wildlife was hunted heavily from the late 19th century well into the 20th century. By 1920 big-game h...

• Finland - country.

  Productive forestland is the most valuable natural resource of Finland. Spruce, pine, and silver birch are the principal trees used to manufacture wood and pulp andpaper products. Finland lacks coal and petroleum resources and is a net importer of energy resources. However, Finland does have significant deposits of peat, which is cut from thenumerous peat bogs that cover much of the north. Peat is an important heat source for homes, and it provides about 7 percent of Finland’s electricity needs....

• Uganda - country.

  Uganda’s population is predominantly rural and is concentrated in the south, particularly in the crescent at the edge of Lake Victoria and in the southwest. Almost allUgandans are black Africans. Foreign residents make up less than 4 percent of the population and come mostly from neighboring states. In 2008 Uganda’s population was estimated at 31,367,972. The estimated growth rate of the population in 2008 was 3.6 percent. The birth rate was 48 per 1,000people and the death rate 12 per 1,000. Th...

• Mental Illness.

  note that under this definition, political dissidents could be considered mentally ill for refusing to accept the dictates of their government. VI PREVALENCE Mental illness affects people of all ages, races, cultures, and socioeconomic classes. The prevalence of mental illness refers to how many people experience a mentalillness during a specified time period. A United States and Worldwide In the United States, researchers estimate that about 24 percent of people 18 or older, or about 44 mill...

• anglais

  3. Joe stood Nelly( his date )up however he must borrow her car to play for Saint (St ) Valentine’s day consequently he has to coax her into lending him her car even if it’s not worthwhile /it’s not worth driving there 4. Spats Colombo runs the speakeasy which was raided last night because Toothpick Charlie gave him away to the police so he’s furious and he wants to take his revenge / avenge himself 5. The two friends / both musicians witness the shooting FRIDAY APRIL 6...

• Matrix Theory and Linear Algebra I INTRODUCTION Matrix Theory and Linear Algebra, interconnected branches of mathematics that serve as fundamental tools in pure and applied mathematics and are becoming increasingly important in the physical, biological, and social sciences.

  vectors and V is called a vector space of dimension m. Two- and three-dimensional Euclidean spaces are vector spaces when their points are regarded as specified by ordered pairs or triples of real numbers. Matrices may be used to describe linear changes from one vector space into another. Contributed By:James Singer Reviewed By:J. Lennart BerggrenMicrosoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

• Dinosaurs.

  protected their necks. Ankylosaurus was about 33 feet (10 meters) long. ORNITHOPODS Ornithopods were once the most numerous plant-eating dinosaurs. There were many different kinds.Over time, ornithopods developed broad beaks. These later ornithopods are called duck-billed dinosaurs.Some ornithopods were small and ran fast. Others were huge. Iquanodon, for example, was 25 feet (7.5 meters) long. PACHYCEPHALOSAURS These dinosaurs walked on two feet. They had thick, dome-shaped skulls. Scienti...

• An Injured Home Run.

  couldn't do it,” Gibson later said. “But once I got up in that cage, I didn't feel anything until I was going around the bases.” Gibson sent Dodgers batboy Mitch Poole to tell Lasorda that the slugger was ready if needed. Lasorda hustled to the batting cage to talk to Gibson himself. “As soonas he heard that I wanted to hit,” Gibson said, “he took off.” During Davis's at bat Gibson entered the dugout and sat in the corner wearing a helmet and holding ablack bat. Davis drew a walk, Gibson lim...

• Decker Slaney Goes the Distance.

  to where I felt relaxed.” She ran the laps in approximately 76 seconds each, running each of the six miles in under 5 minutes 10 seconds to finish at 31 minutes 35.3seconds, the fastest 10,000 meters ever run by a woman on a track. It was her third world record in six weeks. Decker Slaney continued to set world records. At the 1983 World Track and Field Championships in Helsinki, Finland, she raced against the best Russian andEastern European runners. In the 3000 meters she surprised the fie...

• Ivan IV Vasilyevich I INTRODUCTION Ivan IV Vasilyevich or Ivan the Terrible (1530-1584), grand prince of Muscovy (1533-1584) and the first formally proclaimed tsar of Russia (1547-1584).

  That same year Ivan resumed rule over all of Muscovy, much of which was in ruins. But in 1575 he farcically abdicated in favor of a Christianized Tatar, SimeonBekbulatovich, for a year. The tragedies of Ivan's existence were not yet over. In 1582 his daughter-in-law Elena appeared immodestly dressed and Ivan censured her.His son Ivan Ivanovich rose to defend his wife, whereupon the tsar killed his son, his only possible respectable heir. This left as heir Ivan’s feebleminded son Fyodor(reigned 1...

• Ivan IV Vasilyevich.

  That same year Ivan resumed rule over all of Muscovy, much of which was in ruins. But in 1575 he farcically abdicated in favor of a Christianized Tatar, SimeonBekbulatovich, for a year. The tragedies of Ivan's existence were not yet over. In 1582 his daughter-in-law Elena appeared immodestly dressed and Ivan censured her.His son Ivan Ivanovich rose to defend his wife, whereupon the tsar killed his son, his only possible respectable heir. This left as heir Ivan’s feebleminded son Fyodor(reigned 1...

• Kuiper Belt - astronomy.

  III RESEARCH The Kuiper Belt is an exciting area of research in astronomy. The discovery and astronomical exploration of the Kuiper Belt over the past decade have fueled arevolution in scientists’ views of the solar system. Today astronomers recognize the Kuiper Belt as the third major region of the solar system (the other two regions arethe inner solar system, with its small rocky planets, and the outer solar system, with its gas-giant planets). They believe that the belt helps explain Pluto’...

• Captain James Cook.

  After leaving Tahiti, the expedition headed north into uncharted territory. After becoming the first Europeans to sight the Hawaiian Islands (which Cook named theSandwich Islands) in 1778, they sailed along the west coast of Canada and Alaska. Twice Cook explored inlets that offered some promise of a Northwest Passage, but tono avail. After sailing through the Bering Strait into the Arctic Sea and briefly scouting the Asian side of the strait, Cook decided to winter in the Hawaiian Islands. Hein...

• Captain James Cook - explorer.

  After leaving Tahiti, the expedition headed north into uncharted territory. After becoming the first Europeans to sight the Hawaiian Islands (which Cook named theSandwich Islands) in 1778, they sailed along the west coast of Canada and Alaska. Twice Cook explored inlets that offered some promise of a Northwest Passage, but tono avail. After sailing through the Bering Strait into the Arctic Sea and briefly scouting the Asian side of the strait, Cook decided to winter in the Hawaiian Islands. Hein...

• Zululand.

  Mpande died in 1872 and Cetshwayo continued his policy of maintaining good relations with the British. However, British interests soon shifted. For the sake of imperialstrategy and economic opportunity, the British decided to bring all the white-ruled states of southern Africa under their authority. But confederation, as this policy wasknown, seemed to be threatened by an independent, powerful, and unpredictable Zulu state in its midst. Despite desperate negotiations by Cetshwayo, the British we...

• Zululand - U.

  Mpande died in 1872 and Cetshwayo continued his policy of maintaining good relations with the British. However, British interests soon shifted. For the sake of imperialstrategy and economic opportunity, the British decided to bring all the white-ruled states of southern Africa under their authority. But confederation, as this policy wasknown, seemed to be threatened by an independent, powerful, and unpredictable Zulu state in its midst. Despite desperate negotiations by Cetshwayo, the British we...

• Montréal - geography.

  requires children of immigrants to be educated in French. As a result, French-language schools became increasingly multiethnic. With four universities, Montréal is one of the leading centers of higher education in Canada. There are two English-language institutions: McGill University (1821) andConcordia University (1974). Their French-language counterparts are the Université de Montréal (1876) and the University of Québec at Montréal (1969). Both private andstate universities are funded by the p...

• Albert Einstein I INTRODUCTION Albert Einstein (1879-1955), German-born American physicist and Nobel laureate, best known as the creator of the special and general theories of relativity and for his bold hypothesis concerning the particle nature of light.

  On the basis of the general theory of relativity, Einstein accounted for the previously unexplained variations in the orbital motion of the planets and predicted thebending of starlight in the vicinity of a massive body such as the sun. The confirmation of this latter phenomenon during an eclipse of the sun in 1919 became a mediaevent, and Einstein’s fame spread worldwide. For the rest of his life Einstein devoted considerable time to generalizing his theory even more. His last effort, the unifi...

• Albert Einstein.

  On the basis of the general theory of relativity, Einstein accounted for the previously unexplained variations in the orbital motion of the planets and predicted thebending of starlight in the vicinity of a massive body such as the sun. The confirmation of this latter phenomenon during an eclipse of the sun in 1919 became a mediaevent, and Einstein’s fame spread worldwide. For the rest of his life Einstein devoted considerable time to generalizing his theory even more. His last effort, the unifi...

• Giraffe - biology.

  One of the most striking elements of giraffe behavior is the duel between males fighting for mating privileges. Giraffe duels are among the most extraordinary in theanimal kingdom. They start when two males approach each other and begin to rub and intertwine their necks. This behavior—known as necking—allows the opponentsto assess each other’s size and strength. Often, necking alone is enough to establish seniority. If not, the rivals begin to exchange blows with their heads. Each giraffebraces...

• Dark Matter - astronomy.

  observed, and the measured frequency of such events has placed limits on how much dark matter can take the form of MACHOs. From the observations that have beenmade by astronomers, it is now known that MACHOs cannot be the dominant constituent of dark matter. There are simply not enough such gravitational lenses. Physicists suspect that a more exotic form of cold dark matter must exist. This form is not baryonic. Like neutrinos, this form barely interacts with ordinary matter, butis some type of...

• Churchill: "The Sinews of Peace" On March 5, 1946, in a

  safeguards to make it effective, these powers would naturally be confided to that world organisation. Now I come to the second danger of these two marauders which threatens the cottage, the home, and the ordinary people—namely, tyranny. We cannot be blind tothe fact that the liberties enjoyed by individual citizens throughout the British Empire are not valid in a considerable number of countries, some of which are verypowerful. In these States control is enforced upon the common people by variou...

• Un, deux, trois ... l'infini - One Two Three ... lnfinity de George Gamow

  MATHÉMATIQUES e f cé ieux mist r Gam L'humour, dans le domaine de la vulgarisation scientifique, est une chose rare. George Gamow, scientifique de renom aux géniales intuitions, est sans doute l'archétype de cette manière originale et peu fréquente de diffuser le savoir. L'extravagance au service de la science, merci mister Gamow. ~ 1 j 1 0 George Gamow est surtout connu pour son travail de vulgarisation de la science, dans un style à la fois précis et loufoque. 52...

• 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...

• 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...

• Hundred Years' War.

  knowledge of English tactics. Du Guesclin became Constable of France (head of the army) in 1370, and when he died in 1380, Clisson succeeded him. Charles also reorganized the French military, developing a full-time, professional army for the first time, and established a regular system of taxation to pay for it. Inaddition, France gained an important ally on the throne of the Spanish kingdom of Castile, Henry II, who had pledged support for Charles V. When the Caroline war began in 1369, the Eng...

• Hundred Years' War .

  knowledge of English tactics. Du Guesclin became Constable of France (head of the army) in 1370, and when he died in 1380, Clisson succeeded him. Charles also reorganized the French military, developing a full-time, professional army for the first time, and established a regular system of taxation to pay for it. Inaddition, France gained an important ally on the throne of the Spanish kingdom of Castile, Henry II, who had pledged support for Charles V. When the Caroline war began in 1369, the Eng...

• 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...

• 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...

• 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...

• 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...

• Machine I INTRODUCTION Machine, simple device that affects the force, or effort, needed to do a certain amount of work.

  to decrease the amount of force needed to do work or to change the direction of the force. The wheel and axle and some levers can also be used to increase the speedof performance of a task, but doing so always increases the amount of force needed. A Inclined Plane NutsNuts are pieces of metal with a hole in the middle. They are screwed on the end of a bolt as a fastening. Nuts come invarying shapes, depending on their intended use.© Microsoft Corporation. All Rights Reserved. Ramps and staircas...

• Electronic Games.

  arcade game of all time. With Pizza Time Theaters legitimizing the idea of arcades and hits such as Ms. Pac-Man , Asteroids , Donkey Kong , Tempest , Frogger , and Defender bringing new excitement to gaming, the coin-operated video game business boomed. In 1981 Americans spent 75,000 person-years and $5 billion playing video games at anestimated 4,300 arcades in the United States. Many popular arcade games also were translated for use on the Atari 2600 and its chief rivals in the homemarket—M...

• 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...