2538 résultats pour "are"

• Western Philosophy.

  the popular belief in personal deities, but he failed to explain the way in which the familiar objects of experience could develop out of elements that are totally differentfrom them. Anaxagoras therefore suggested that all things are composed of very small particles, or “seeds,” which exist in infinite variety. To explain the way in whichthese particles combine to form the objects that constitute the familiar world, Anaxagoras developed a theory of cosmic evolution. He maintained that the activ...

• 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...

• Canadian Parliament.

  government’s legislative program. Members of Commons can also present a motion in response to the Budget Speech, which reviews the government’s economicrecord, taxation, and expenditure plans, and to Supply Motions, which concern budgets for individual departments. If a majority of MPs support a no-confidence motion,the government must resign. Also, if Parliament rejects a significant government proposal, the government is expected to resign and request the governor-general to call an election....

• Homer I INTRODUCTION Homer According to tradition, the Greek poet Homer is believed to be the author of the Iliad and the Odyssey, two great epics of ancient Greek literature.

  The Return of OdysseusAfter the Greek warrior Odysseus returns from the Trojan War to his home in Ithaca, he kills the uninvited and unwantedsuitors of his wife, Penelope, who believed him to be dead. Odysseus’s astonishing skill with the bow convinces Penelopethat he is indeed her long-absent husband. This anonymous engraving is of an unknown date.Corbis The Odyssey narrates the return of the Greek hero Odysseus from the Trojan War. The opening scenes depict the disorder that has arisen in Ody...

• Earth (planet).

  Milky Way to complete one revolution around the Galaxy’s center. Earth’s axis of rotation is inclined (tilted) 23.5° relative to its plane of revolution around the Sun. This inclination of the axis creates the seasons and causes the height of the Sun in the sky at noon to increase and decrease as the seasons change. The Northern Hemisphere receives the most energy from the Sun when it is tiltedtoward the Sun. This orientation corresponds to summer in the Northern Hemisphere and winter in the S...

• Earth (planet) - astronomy.

  Milky Way to complete one revolution around the Galaxy’s center. Earth’s axis of rotation is inclined (tilted) 23.5° relative to its plane of revolution around the Sun. This inclination of the axis creates the seasons and causes the height of the Sun in the sky at noon to increase and decrease as the seasons change. The Northern Hemisphere receives the most energy from the Sun when it is tiltedtoward the Sun. This orientation corresponds to summer in the Northern Hemisphere and winter in the S...

• Ecosystem.

  work. The tiny bacteria and fungi feed upon the remains of the salmon. They break down the salmon intochemical nutrients. Nutrients from the salmon go into the soil. The roots of plants along the riverbank take up the nutrients. They use the nutrients to make food. Inthis way, nutrients get recycled back through the ecosystem. WHAT CAN HARM AN ECOSYSTEM? Any change in one living or nonliving part of an ecosystem can cause changes in other parts. Droughts,storms, and fires can change ecosystems....

• Ireland - country.

  F Plants and Animals Ireland’s animal life does not differ markedly from that of England or France. Over many centuries of human settlement almost all of Ireland’s natural woodlands werecleared, and indigenous animals such as bear, wolf, wildcat, beaver, wild cattle, and the giant Irish deer (a type of fallow deer) gradually disappeared. However, thehardy and versatile Connemara pony, Ireland’s only native pony breed, has been used by Irish farmers since prehistoric times. The great auk, or gar...

• Planetary Science - astronomy.

  III ORIGINS AND COMPOSITIONS OF PLANETS Astronomers believe that planetary systems are formed of elemental materials that were created in the interiors of giant stars. Some of this material comes from giantstars that shed material into space as they age. Most of the matter to form planets, however, comes from stars that explode as supernovas and spread debris enrichedwith the heavier chemical elements into space. According to the currently accepted views, the most likely first stage in the evo...

• Shanghai - geography.

  language. V EDUCATION AND CULTURE Shanghai is one of China’s leading centers of learning and culture. The metropolitan area is home to more than 40 institutions of higher learning. These include some ofChina’s most famous universities, such as Fudan University (founded in 1905), Tongji University (1907), and the East China Normal University (1951). A large branch ofthe Chinese Academy of Sciences is located in Shanghai, and extensive research is undertaken in areas such as semiconductors, laser...

• Buddhism.

  Although never actually denying the existence of the gods, Buddhism denies them any special role. Their lives in heaven are long and pleasurable, but they are in thesame predicament as other creatures, being subject eventually to death and further rebirth in lower states of existence. They are not creators of the universe or incontrol of human destiny, and Buddhism denies the value of prayer and sacrifice to them. Of the possible modes of rebirth, human existence is preferable, because thedeitie...

• Magnetism I 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...

• Jerusalem - geography.

  There are many other artifacts in the city, tied to various periods of history; those of Canaanite, Israelite, Greek, Roman, Arab, Crusader, and Ottoman origin areamong the more prominent. Modern attractions include the Israel Museum (completed in 1965), which houses the Shrine of the Book, where the Dead Sea Scrolls areexhibited; the Rockefeller Museum (opened in 1938), which contains archaeological finds; the Yad Vashem Holocaust Museum; the Museum of Biblical Archaeology; theMuseum of Islamic...

• Canadian Forces.

  As the Land Force Command component of the CF, the Canadian army is responsible for land combat and for physically protecting people and land-based resources. Itis the component of the CF most often called on to support international military operations and peacekeeping missions and to maintain order in times of civil unrest. A Organization The 20,900 personnel who comprise the army’s regular force are organized into four geographically based areas. Land Force Atlantic includes the provinces of...

• Jakarta - geography.

  than half the households use piped water for drinking. Fewer still use piped water for bathing and washing. Only a small part of Jakarta is served by piped sewers and manyhomes lack septic tanks. III ECONOMY Jakarta developed as a center of trade under the Europeans and it continues to play an important role in international and domestic commerce. The metropolitan region isIndonesia's largest economic center; it attracts most of Indonesia's domestic and foreign investment and, as the administr...

• Colleges and Universities.

  and (3) large universities that include undergraduate programs in addition to graduate and professional schools. D Graduate and Professional Schools Professional schools are typically divisions of large universities. They offer specialized education in a variety of professional fields, such as education, business, medicine,law, social work, agriculture, journalism, architecture, fine arts, nursing, engineering, and music. Some professional schools offer four- or five-year programs leading toa b...

• Gabon - country.

  government is engaged in preservation and reforestation programs. The fish catch in 2005 was 43,941 metric tons. C Mining Mining has developed rapidly since Gabon’s independence in 1960. Annual production of extremely high-grade manganese ore, from Moanda in the southeast, was1,090,000 metric tons in 2004. The rich deposits of iron ore located at Mekambo and Bélinga in the northeast have reserves estimated at more than 500 million metrictons. Exploitation of the iron ore has been hampered by th...

• Confucianism.

  IV NEO-CONFUCIANISM After centuries of intellectual and cultural dominance by Buddhism, China began to experience a revival of Confucian thought during the Tang dynasty ( AD 618-907). It was led by poet and essayist Han Yu (Han Yü). Han Yu attacked Buddhism and Daoism, which he believed had kept government officials from seeing how they couldhelp the people. To further public welfare, he urged them to study the way of the ancient sages through the Five Classics . Han Yu almost lost his life f...

• Cuba - country.

  Only two land mammals, the hutia, or cane rat, and the solenodon, a rare insectivore that resembles a rat, are known to be indigenous. The island has numerous batsand nearly 300 kinds of birds, including vultures, wild turkeys, quail, finches, gulls, macaws, parakeets, and hummingbirds. The bee hummingbird of Cuba is thesmallest bird in the world. Among the few reptiles are tortoises, caimans, the Cuban crocodile, and a species of boa that can attain a length of 3.7 m (12 ft). More than700 speci...

• Native Americans of Middle and South America.

  A line that snakes across central Mexico near the Tropic of Cancer forms the northern boundary of Mesoamerica; north of this line rainfall sharply declines and theclimate is much drier. The ancient civilizations of Mesoamerica all arose and developed in the area between this line and the Guatemalan highlands far to the south. Richvolcanic soils are found throughout much of the region. A2 People and Languages Mesoamerica was a great melting pot, home to many peoples and interrelated cultures. In...

• Houston - geography.

  Prominent historical and cultural institutions include the Civic Center Complex, located in the central business district. The complex is composed of the George R. BrownConvention Center; the Wortham Center, which is the home of the Houston Grand Opera and the Houston Ballet; and the Jesse H. Jones Hall for Performing Arts, whichis the home of the Houston Symphony. The nearby Alley Theatre houses a professional repertory acting company. Among other local professional performance groupsare the Ma...

• Taxation.

  Thus, corporate income faces a higher tax burden than income earned by individuals or by other types of businesses. Tax legislation passed in 2003 in the United Statesattempted to address this issue by lowering the tax rate on dividends. Some economists have proposed abolishing the corporate income tax and instead taxing the owners of corporations (shareholders) through the personal income tax.Other students of the tax system see the corporate income tax as the price corporations pay in return f...

• 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...

• Native Americans of North America.

  addition to smallpox and measles, explorers and colonists brought a host of other diseases: bubonic plague, cholera, typhoid fever, scarlet fever, pleurisy, mumps,diphtheria, pneumonia, whooping cough, malaria, yellow fever, and various sexually transmitted infections. Despite the undisputed devastation wreaked on Indian populations after European contact, native populations showed enormous regional variability in their response todisease exposure. Some peoples survived and, in some cases, even...

• Native Americans of North America - Canadian History.

  addition to smallpox and measles, explorers and colonists brought a host of other diseases: bubonic plague, cholera, typhoid fever, scarlet fever, pleurisy, mumps,diphtheria, pneumonia, whooping cough, malaria, yellow fever, and various sexually transmitted infections. Despite the undisputed devastation wreaked on Indian populations after European contact, native populations showed enormous regional variability in their response todisease exposure. Some peoples survived and, in some cases, even...

• Indian Literature I 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...

• Cleveland (Ohio) - geography.

  III POPULATION According to the national census, the population of Cleveland was 505,616 in 1990, a decline of 11.9 percent from the 1980 population of 573,822. The decrease continuedinto the 1990s, falling a further 5.4 percent between 1990 and 2000. The population was 478,403 in 2000. By 2006, Cleveland's population was estimated at 444,313. Thedecrease was attributed to a continuing flight to the suburbs, begun before 1970 and fueled by racial polarization and public school problems. In 2000...

• Federal Republic of Germany - country.

  B Rivers and Lakes Rivers have played a major role in Germany’s economic development. The Rhine River flows in a northwesterly direction from Switzerland through much of westernGermany and The Netherlands into the North Sea. It is a major European waterway and a pillar of commerce and trade. Its primary German tributaries include theMain, Mosel, Neckar, and Ruhr rivers. The Oder (Odra) River, along the border between Poland and Germany, runs northward and empties into the Baltic; it provides an...

• Judaism.

  is learned or memorized”), the earliest document of rabbinic literature, edited in Palestine at the turn of the 3rd century. Subsequent rabbinic study of the Mishnah inPalestine and Babylonia generated two Talmuds (“that which is studied”; also called Gemera, an Aramaic term with the same meaning; see Talmud), wide-ranging commentaries on the Mishnah. The Babylonian Talmud, edited about the 6th century, became the foundation document of rabbinic Judaism. Early rabbinic writings also include exe...

• Statistics I INTRODUCTION Statistics, branch of mathematics that deals with the collection, organization, and analysis of numerical data and with such problems as experiment design and decision making.

  Professional pollsters typically conduct their surveys among sample populations of 1,000 people. Statistical measurementsshow that reductions in the margin of error flatten out considerably after the sample size reaches 1,000.© Microsoft Corporation. All Rights Reserved. The raw materials of statistics are sets of numbers obtained from enumerations or measurements. In collecting statistical data, adequate precautions must be taken tosecure complete and accurate information. The first problem of...

• George Frideric Handel I INTRODUCTION Handel's Water Music In addition to his popular operas and oratorios, German-born composer George Frideric Handel wrote music in the 1700s for the church and for royal celebrations.

  During the 1720s and 1730s Handel worked primarily as a composer and producer of operas for the London stage. This extremely productive phase of his career beganwith the opening of the Royal Academy of Music in London in 1719. The Royal Academy was founded with the support of the king and aristocratic subscribers for theproduction of Italian operas. Its directors sent Handel to continental Europe to hire some of the world’s greatest singers. Handel was not the only composer writingoperas for Aca...

• United States House of Representatives.

  Because of the high cost of elections and the short two-year term of office, members of the House campaign almost constantly. They spend much of their time raisingcampaign funds, and they frequently return to their districts to keep in touch with voters. Because the elections are so frequent, House members tend to pay closeattention to how their votes in Congress will be seen in the short term. House members tend to come from wealthier family backgrounds than average Americans. Few working class...

• 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...

• World Energy Supply.

  In the 1990s, oil production by non-OPEC countries remained strong and production by OPEC countries rebounded. The result at the end of the 20th century was aworld oil surplus and prices (when adjusted for inflation) that were lower than in 1972. Experts are uncertain about future oil supplies and prices. Low prices have spurred greater oil consumption, and experts question how long world petroleum reservescan keep pace with increased demand. Many of the world’s leading petroleum geologists beli...

• Artistic interpretation

  that a musical passage leads back to the tonic key is to describe it non-interpretively, but to explain it simply as abridge passage is to interpret it, however obviously. 2 Meaning Most theorists of literary criticism agree that the interpretation of literature aims to disclose meanings in texts.They disagree about the ground of such meaning, whether it is simply the semantic conventions of the language,the intentions of authors, or the interpretive activities of readers or critics. But i...

• Physics I INTRODUCTION Physics, major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces.

  Starting about 1665, at the age of 23, Newton enunciated the principles of mechanics, formulated the law of universal gravitation, separated white light into colors,proposed a theory for the propagation of light, and invented differential and integral calculus. Newton's contributions covered an enormous range of naturalphenomena: He was thus able to show that not only Kepler's laws of planetary motion but also Galileo's discoveries of falling bodies follow a combination of his ownsecond law of m...

• Turkmenistan - country.

  A Ethnic Groups With Turkmens constituting 77 percent of the population, Turkmenistan is the most ethnically homogeneous of the Central Asian republics. Uzbeks make up the largestminority group, with about 9 percent of the population. Other ethnic groups include Russians, Kazakhs, Tatars, Ukrainians, Azeris (ethnic Azerbaijanis), Armenians, andBaluch. In 1993 a bilateral treaty between Turkmenistan and Russia granted dual citizenship to Russians in the republic. At the 1995 census Russians cons...

• Liver.

  by bacterial infections. But hepatitis is most often caused by one of several viruses. The hepatitis A virus (HAV) can produce flulike symptoms and jaundice, but manypeople who contract it have no symptoms. The disease tends to resolve on its own. Because HAV lives in feces in the intestinal tract, hepatitis A is prevalent in areaswhere drinking water is contaminated with raw sewage. Good hygiene practices and a hepatitis A vaccination are effective measures of prevention. Hepatitis B is a more...

• 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...

• Depression (psychology).

  IV CAUSES Some depressions seem to come out of the blue, even when things are going well. Others seem to have an obvious cause: a marital conflict, financial difficulty, or somepersonal failure. Yet many people with these problems do not become deeply depressed. Most psychologists believe depression results from an interaction betweenstressful life events and a person’s biological and psychological vulnerabilities. A Biological Factors Depression runs in families. By studying twins, researche...

• Extreme Sports.

  racing events are the Raid Gauloises and the Eco-Challenge. Created in 1989 by French journalist Gerard Fusil, the Raid Gauloises is a grueling two-week adventure racein which five-person teams cross rugged and remote terrain. The inaugural Raid was held in New Zealand, and subsequent races have been staged in Costa Rica,Madagascar, Borneo, and Chile. The race has five separate stages designed to fit each location’s unique terrain. Stages may require horseback riding, white-waterpaddling, mounta...

• Guyana - country.

  European patterns of living. People of mixed African and European ancestry form a distinct group in Guyana, maintaining closer social ties to the European communitythan to the African Guyanese community. Asians from the Indian subcontinent began to arrive in the 19th century, following the abolition of slavery in Guyana, to work as indentured and contract laborers. Theycontinued to arrive until 1917, when Britain outlawed indentured servitude. Thousands of Indians chose to remain in Guyana after...

• Dominican Republic - country.

  Manatees and sea turtles also live in Dominican waters. Common birds include blue herons, glossy ibis, flamingos, and brown pelicans. E Environmental Issues Urban dwellers of the Dominican Republic enjoy good access to safe water, but rural communities do not. While current water use is low relative to available resources,water shortages do occur. Although deforestation was once a serious problem in the Dominican Republic, by the beginning of the 21st century, the annual rate of deforestation h...

• Dallas (Texas) - geography.

  VI RECREATION Dallas contains more than 400 parks that cover a total of about 20,000 hectares (about 50,000 acres). Notable parks include Marsalis Park, which contains the DallasZoo, and the parks surrounding White Rock Lake, Bachman Lake, and Lake Cliff. City-owned greenbelts parallel White Rock Creek, Turtle Creek, and the Trinity River.Fair Park contains a number of museums, the city aquarium, and the Cotton Bowl stadium (the site of the annual Cotton Bowl college football game), as well as...

• Portland - geography.

  Garden arena, which opened in 1995. In 2000 the Portland Fire, an expansion Women's National Basketball Association team, began play in the Rose Garden as well. VI ECONOMY Portland enjoys a diversified economy. Major manufactured products include paper, transportation equipment, metal products, sportswear, and electronic componentsand equipment. Major corporations headquartered in the metropolitan region include Nike, a leader in the manufacture of sports footwear, in Beaverton; Louisiana-Paci...

• Virus (computer).

  how closely it resembles a virus. It relies on experience with previous viruses to predict the likelihood that a suspicious file is an as-yet unidentified or unclassified newvirus. Other types of antiviral software include monitoring software and integrity-shell software. Monitoring software is different from scanning software. It detects illegal orpotentially damaging viral activities such as overwriting computer files or reformatting the computer's hard drive. Integrity-shell software establis...

• Ancient Egypt - history.

  The Nile River runs through the ancient city of Thebes in eastern Egypt. For a time, beginning in 2040 bc, Thebes was the capital ofEgypt.Farrell Grehan/Photo Researchers, Inc. According to inscriptions and documents found by archaeologists, the Egyptians called their country Kemet, meaning “the Black Land,” a reference to the dark, fertile soil that remained after the Nile floodwaters had receded. They also used another term, Deshret, or “the Red Land,” a designation for the desert sands th...

• Mesoamerica.

  for cooking. In other regions, the earliest ceramics are more sophisticated technically and aesthetically. At around 1800 BC in the Pacific coastal region of Soconusco (in what is now southeastern Chiapas State, Mexico), the earliest pottery was very complex both in forms and decoration. It seems to have had a social function and beenused primarily for ritual feasting. III MAJOR CIVILIZATIONS Over a period of 3000 years, beginning in about 1500 BC, a number of important cultures emerged in M...

• Health Insurance.

  needs services. Essentially, individuals make regular payments to the plan rather than having to pay especially large sums at any one time in the event of sudden illnessor injury. In this way, the group as a whole funds expensive treatments for those few who need them. Many people believe that in addition to providing financial stability, health insurance can promote good health. Supporters of this idea claim that by lowering thepersonal cost of services, insurance induces individuals to seek he...

• Native American Languages.

  From Nahuatl, spoken in Middle America, come avocado, cacao, cocoa, chile/chili, chocolate, coyote, tamale , tomato , and many others. Contributions from South American languages include jaguar, cashew, tapioca, and toucan from Tupinambá; alpaca, condor, jerky, llama, puma, and quinine from Quechua; and barbecue, canoe, guava, hammock, hurricane, iguana, maize, papaya, and potato from Maipurean (Arawakan). Native American languages, in turn, have borrowed words from European language...