557 résultats pour "founder"

• 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...

• 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...

• Computer Science.

  theoretical research is called algorithmic complexity. Computer scientists in this field seek to develop techniques for determining the inherent efficiency of algorithmswith respect to one another. Another area of theoretical research called computability theory seeks to identify the inherent limits of computation. Software engineers use programming languages to communicate algorithms to a computer. Natural languages such as English are ambiguous—meaning that theirgrammatical structure and vocab...

• God. I INTRODUCTION God, the center and focus of religious faith, a holy

  C Islam Islam arose as a powerful reaction against the ancient pagan cults of Arabia, and as a consequence it is the most starkly monotheistic of the three biblically rootedreligions. The name Allah means simply “the God.” He is personal, transcendent, and unique, and Muslims are forbidden to depict him in any creaturely form. The primary creed is that “There is no god but Allah, and Muhammad is the apostle of Allah.” Allah has seven basic attributes: life, knowledge, power, will, hearing, se...

• Greenhouse Effect.

  addition, humans cut down huge tracts of trees for lumber or to clear land for farming or building. This process, known as deforestation, can both release the carbonstored in trees and significantly reduce the number of trees available to absorb carbon dioxide. As a result of these human activities, carbon dioxide in the atmosphere is accumulating faster than Earth’s natural processes can absorb the gas. By analyzing airbubbles trapped in glacier ice that is many centuries old, scientists have d...

• Galileo I INTRODUCTION Galileo (1564-1642), Italian physicist and astronomer who, with German astronomer Johannes Kepler, initiated the scientific revolution that flowered in the work of English physicist Sir Isaac Newton.

  V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...

• Galileo.

  V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...

• Excerpt from Martin Chuzzlewit - anthology.

  But there is one other piece of evidence, bearing immediate reference to their close connextion with this memorable event in English History, which must carryconviction, even to a mind (if such a mind there be) remaining unconvinced by these presumptive proofs. There was, within a few years, in the possession of a highly respectable and in every way credible and unimpeachable member of the Chuzzlewit Family (for hisbitterest enemy never dared to hint at his being otherwise than a wealthy man...

• Charles Dickens I INTRODUCTION Charles Dickens English author Charles Dickens ranks as one of the most popular writers in the history of world literature.

  Papers of the Pickwick Club (1836-1837; 1837); The Adventures of Oliver Twist (1837-1839; 1838); The Life and Adventures of Nicholas Nickleby (1838-1839; 1839); The Old Curiosity Shop (1840-1841; 1841); Barnaby Rudge (1841); The Life and Adventures of Martin Chuzzlewit (1843-1844; 1844); Dombey and Son (1846-1848; 1848); The Personal History of David Copperfield (1849-1850; 1850); Bleak House (1852-1853; 1853); Hard Times (1854); Little Dorrit (1855-1857; 1857); A Tale of Tw...

• Benjamin Franklin.

  Copley Medal for distinguished contributions to experimental science. Franklin also exerted a great influence on education in Pennsylvania. In 1749 he wrote thepamphlet Proposals Relating to the Education of Youth in Pennsylvania; its publication led to the establishment in 1751 of the Academy of Philadelphia, later to become the University of Pennsylvania. The curriculum he suggested departed considerably from the study of the Greek and Roman classics then in vogue. Instead itemphasized Engl...

• Benjamin Franklin - USA History.

  Copley Medal for distinguished contributions to experimental science. Franklin also exerted a great influence on education in Pennsylvania. In 1749 he wrote thepamphlet Proposals Relating to the Education of Youth in Pennsylvania; its publication led to the establishment in 1751 of the Academy of Philadelphia, later to become the University of Pennsylvania. The curriculum he suggested departed considerably from the study of the Greek and Roman classics then in vogue. Instead itemphasized Engl...

• From Bulfinch's Mythology: Prometheus and Pandora - anthology.

  The world being thus furnished with inhabitants, the first age was an age of innocence and happiness, called the Golden Age. Truth and right prevailed, though not enforced by law, nor was there any magistrate to threaten or punish. The forest had not yet been robbed of its trees to furnish timbers for vessels, nor had men builtfortifications round their towns. There were no such things as swords, spears, or helmets. The earth brought forth all things necessary for man, without his labour inplo...

• Herman Melville.

  information in Omoo , but various religious groups condemned both books for their unfavorable comments on the work and insensitivity of missionaries in the South Seas. Mardi is a philosophical allegory framed by another adventure at sea. The book’s hero, accompanied by characters representing the intellect, poetry, history, and philosophy, searches the world for universal truth. The book is filled with descriptions—intended as allegories—of human customs, religions, governments, and historical...

• 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...

• Influenza.

  days and disappear in seven to ten days. However, coughing and fatigue may persist for two or more weeks. Death from influenza itself is rare. But influenza can aggravate underlying medical conditions, such as heart or lung disease. Invading influenza viruses produceinflammation in the lining of the respiratory tract, damage that increases the risk that secondary infections will develop. Common complications include bronchitis,sinusitis, and bacterial pneumonia, occurring most frequently in olde...

• Isaac NewtonIINTRODUCTIONIsaac Newton (1642-1727), English physicist, mathematician, and natural philosopher, considered one of the most important scientists of all time.

  B Calculus (Newton’s “Fluxional Method”) In 1669 Newton gave his Trinity mathematics professor Isaac Barrow an important manuscript, which is generally known by its shortened Latin title, De Analysi . This work contained many of Newton’s conclusions about calculus (what Newton called his “fluxional method”). Although the paper was not immediately published, Barrowmade its results known to several of the leading mathematicians of Britain and Europe. This paper established Newton as one of the...

• Isaac Newton.

  B Calculus (Newton’s “Fluxional Method”) In 1669 Newton gave his Trinity mathematics professor Isaac Barrow an important manuscript, which is generally known by its shortened Latin title, De Analysi . This work contained many of Newton’s conclusions about calculus (what Newton called his “fluxional method”). Although the paper was not immediately published, Barrowmade its results known to several of the leading mathematicians of Britain and Europe. This paper established Newton as one of the t...

• The Souls of Black Folk by W.

  in amused contempt and pity. One ever feels his two-ness,—an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in onedark body, whose dogged strength alone keeps it from being torn asunder. The history of the American Negro is the history of this strife—this longing to attain self-conscious manhood, to merge his double self into a better and truer self. Inthis merging he wishes neither of the older selves to be lost. He would not Africanize America, f...

• Air Pollution.

  Several pollutants attack the ozone layer. Chief among them is the class of chemicals known as chlorofluorocarbons (CFCs), formerly used as refrigerants (notably in airconditioners), as agents in several manufacturing processes, and as propellants in spray cans. CFC molecules are virtually indestructible until they reach thestratosphere. Here, intense ultraviolet radiation breaks the CFC molecules apart, releasing the chlorine atoms they contain. These chlorine atoms begin reacting withozone, br...

• United States (Overview) - country.

  parts. IV UNITED STATES PEOPLE When Europeans first reached North America in the 1520s, they encountered other people—Native Americans—and they also encountered a new geography. Someimagined they were entering “a howling wilderness”—an environment filled with exotic flora and fauna but sparsely populated. In reality, they found their way to alandmass that was widely settled. But soon after the Europeans’ arrival, the population of the Americas plummeted, largely because Native Americans lacked...

• Reconstruction (U.

  Instead, Congress began a lengthy debate over Reconstruction policy. The program eventually enacted resulted from a series of compromises among Republicanfactions; the Radicals were never powerful enough to gain everything they sought. Still, fueled by anger at the president's refusal to compromise and at the appearanceof former Confederates returning to power throughout the South, members of Congress moved increasingly toward the Radicals. The key Reconstruction measuresenacted aimed to produce...

• Roman Mythology.

  Her temple on the Aventine Hill in Rome was a center for organizations of skilled craftspeople. According to tradition, in 509 BC the dynasty of Etruscan kings ended and the Roman Republic was founded. The republic was ruled by two chief magistrates, called consuls, who were elected by the people to one-year terms. During the time of the republic, the Capitoline temple became the most important public shrine of theRoman people and the focus of public worship. Each January, the new consuls offer...

• Gravitation I INTRODUCTION Gravitation, the force of attraction between all objects that tends to pull them toward one another.

  precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...

• Gravitation - astronomy.

  precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...

• Marketing.

  Where advertising reaches a mass audience, personal or direct selling focuses on one customer at a time. That kind of individual attention makes direct sellingexpensive, but it also makes it effective. As the costs of personal selling have risen, the utilization of salespeople has changed. Simple transactions are completed byclerks. Salespeople are now used primarily where the products are complex and require detailed explanation, customized application, or careful negotiation over priceand paym...

• Mexican Revolution.

  growing economic and social difficulties. Although Madero called for free and democratic elections, and a ban on reelection at all levels of government, he offered little tourban workers seeking higher wages and better working conditions, or to indigenous people seeking the restoration of their traditional lands. Madero’s intention was tolead a political rebellion, not a social revolution. Despite the political nature of the plan, it became a rallying point for poor and working-class Mexicans, m...

• Money.

  A Early Monetary Regulations In the American colonies, coins of almost every European country circulated, with the Spanish dollar predominating. Because of the scarcity of coins, the colonists alsoused various primitive mediums of exchange, such as bullets, tobacco, and animal skins. Many of the colonies issued paper money that circulated at varying rates ofdiscount. The first unified currency consisted of the notes issued by the Continental Congress to finance the American Revolution. These no...

• Confucian philosophy, Korean

  neglected by more traditional Confucianism. Read with new eyes, an entirely new level of meaning was uncovered in the ancient texts: they discovered a Confucian foundation for the meditative cultivation of consciousness that had been a particular strength of the Buddhists, and to frame it and provide an account of sagehood equal to Buddhist talk of enlightenment, they found a complete metaphysical system, a Confucian version of the kind of thinking that had been elaborated mainly under Daoist au...

• George Herbert Walker Bush.

  Lebanon. More troubling was the disclosure that agents operating under direct White House supervision used profits from the arms sales to buy weapons for thecontras, a group of anti-government Nicaraguan rebels, despite an explicit congressional ban on such aid. Bush later claimed that he opposed the arms-for-hostagesdeal, but offered little evidence to back his claims ( see Iran-Contra Affair). C 1988 Presidential Election While the Reagan-Bush program helped produce prosperity for the wealth...

• George Herbert Walker Bush - USA History.

  Lebanon. More troubling was the disclosure that agents operating under direct White House supervision used profits from the arms sales to buy weapons for thecontras, a group of anti-government Nicaraguan rebels, despite an explicit congressional ban on such aid. Bush later claimed that he opposed the arms-for-hostagesdeal, but offered little evidence to back his claims ( see Iran-Contra Affair). C 1988 Presidential Election While the Reagan-Bush program helped produce prosperity for the wealth...

• Sweden - country.

  mi) and is Sweden’s second largest lake, after Vänern. The two lakes, together with several smaller lakes, rivers, and canals, form an internal water route called theGöta Canal. Built in the early 19th century, the Göta Canal extends for about 386 km (about 240 mi) and provides a scenic transportation link between the Baltic Sea,at Stockholm, and the Kattegat. Sweden’s other large lakes in the district include Mälaren, Hjälmaren, and the famously picturesque Siljan. D Climate Although one-seven...

• 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...

• Earthquake.

  III CAUSES Most earthquakes are caused by the sudden slip along geologic faults. The faults slip because of movement of the Earth’s tectonic plates. This concept is called theelastic rebound theory. The rocky tectonic plates move very slowly, floating on top of a weaker rocky layer. As the plates collide with each other or slide past eachother, pressure builds up within the rocky crust. Earthquakes occur when pressure within the crust increases slowly over hundreds of years and finally exceeds...

• John F.

  by the United States, was unable to withstand the advance of Communist forces under Mao Zedong (Mao Tse-tung). By the end of 1949 government troops had beenoverwhelmingly defeated, and Chiang led his forces into exile on Taiwan. The triumphant Mao formed the People’s Republic of China. Truman’s critics, includingKennedy, charged that the administration had failed to support Chiang Kai-shek against the Communists. Kennedy easily won reelection to Congress in 1948 and 1950. In 1952 he decided to r...

• John F.

  by the United States, was unable to withstand the advance of Communist forces under Mao Zedong (Mao Tse-tung). By the end of 1949 government troops had beenoverwhelmingly defeated, and Chiang led his forces into exile on Taiwan. The triumphant Mao formed the People’s Republic of China. Truman’s critics, includingKennedy, charged that the administration had failed to support Chiang Kai-shek against the Communists. Kennedy easily won reelection to Congress in 1948 and 1950. In 1952 he decided to r...

• Harry S.

  B2 Presiding Judge Political machines, such as the Pendergast organization, were common to both parties in the 1920s. They were based on the spoils system, in which winning politiciansgave government jobs to those loyal party members who had helped them get elected. Using government jobs as rewards, politicians created efficient (and oftenalmost unstoppable) vote-getting “machines,” in which party loyalty was often more important than doing any work. Without local machine support a political ca...

• Harry S.

  B2 Presiding Judge Political machines, such as the Pendergast organization, were common to both parties in the 1920s. They were based on the spoils system, in which winning politiciansgave government jobs to those loyal party members who had helped them get elected. Using government jobs as rewards, politicians created efficient (and oftenalmost unstoppable) vote-getting “machines,” in which party loyalty was often more important than doing any work. Without local machine support a political ca...

• Cell (biology) - biology.

  proteins, or other proteins required by the cell. While relatively simple in construction, prokaryotic cells display extremely complex activity. They have a greater range of biochemical reactions than those found in theirlarger relatives, the eukaryotic cells. The extraordinary biochemical diversity of prokaryotic cells is manifested in the wide-ranging lifestyles of the archaebacteria andthe bacteria, whose habitats include polar ice, deserts, and hydrothermal vents—deep regions of the ocean un...

• Croatia - country.

  III PEOPLE OF CROATIA The total population of Croatia at the time of the 1991 census was 4,784,265; a 2008 estimate was 4,491,543. During and after the war ethnic Serbs fled Croatia whileethnic Croats moved in. Croatia’s population growth rate in 2008 was -0.04 percent, despite population gains due to immigration. Croatia’s natural population growthrate, which measures births and deaths, has been negative since 1998. Life expectancy at birth was 75 years in 2008. The population density in 2008...

• Andrew Jackson.

  against a resolution praising President George Washington’s administration. Jackson claimed that Washington’s policy toward Native Americans was too lenient and thatJay’s Treaty, concluded with the British under Washington’s administration, was too damaging to American interests. After one year in the House, Jackson was elected to fill out an unexpired term in the U.S. Senate, the other chamber of the Congress of the United States. He servedfrom September 1797 to April 1798 and then retired to p...

• Andrew Jackson

  against a resolution praising President George Washington’s administration. Jackson claimed that Washington’s policy toward Native Americans was too lenient and thatJay’s Treaty, concluded with the British under Washington’s administration, was too damaging to American interests. After one year in the House, Jackson was elected to fill out an unexpired term in the U.S. Senate, the other chamber of the Congress of the United States. He servedfrom September 1797 to April 1798 and then retired to p...

• Andrew Jackson - USA History.

  against a resolution praising President George Washington’s administration. Jackson claimed that Washington’s policy toward Native Americans was too lenient and thatJay’s Treaty, concluded with the British under Washington’s administration, was too damaging to American interests. After one year in the House, Jackson was elected to fill out an unexpired term in the U.S. Senate, the other chamber of the Congress of the United States. He servedfrom September 1797 to April 1798 and then retired to p...

• Greek Mythology.

  world in search of her; as a result, fertility left the earth. Zeus commanded Hades to release Persephone, but Hades had cunningly given her a pomegranate seed toeat. Having consumed food from the underworld, Persephone was obliged to return below the earth for part of each year. Her return from the underworld each yearmeant the revival of nature and the beginning of spring. This myth was told especially in connection with the Eleusinian Mysteries, sacred rituals observed in the Greektown of Ele...

• 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...

• Berlin - geography.

  boroughs of Wedding and Tiergarten. Other important central areas include Kreuzberg and Friedrichshain, now united as the Friedrichshain-Kreuzberg borough, andPrenzlauer Berg, now incorporated as a part of the Pankow borough. Tiergarten contains a large wooded park, a zoo, and a variety of public monuments as well as the large, modern Congress Hall and the Reichstag building, which wasbuilt from 1884 to 1894. The Reichstag and the surrounding area have undergone renovation to accommodate the Bun...

• Light - astronomy.

  Each different frequency or wavelength of visible light causes our eye to see a slightly different color. The longest wavelength we can see is deep red at about 700 nm.The shortest wavelength humans can detect is deep blue or violet at about 400 nm. Most light sources do not radiate monochromatic light. What we call white light,such as light from the Sun, is a mixture of all the colors in the visible spectrum, with some represented more strongly than others. Human eyes respond best to greenlight...

• Christmas.

  The new custom of Christmas gift giving allowed the marketplace to exert an unprecedented influence on holiday celebrations. Commercial innovations such asdepartment stores and mass advertising further expanded the custom of exchanging Christmas gifts. Seasonal retail sales helped fuel the economy, causing merchantsand advertisers to become some of the season’s most ardent promoters. Many holiday celebrants regretted these changes, however, and began voicing the nowcommon lament that Christmas h...

• Zimbabwe - country.

  contamination—especially from the dieldrin and DDT used in tsetse fly control—has significantly affected wildlife and human health. III PEOPLE AND SOCIETY OF ZIMBABWE In 2008 Zimbabwe’s population was estimated to be 12,382,920, giving the country a population density of 32 persons per sq km (83 per sq mi). With a birth rate of27 per 1,000 and a death rate of 22 per 1,000, Zimbabwe’s population growth rate is 0.6 percent. Life expectancy at birth was estimated at 40 years in 2008, downfrom 59...

• Mexico City - geography.

  The park houses some of Mexico's most important public buildings, including Chapultepec Castle. Construction of the castle began in 1783. Positioned on the park’shighest elevation, the castle functioned as a fortress during colonial times. It once served as the presidential residence and now houses the National Museum of History,which includes murals by 20th-century Mexican painter Juan O'Gorman. Los Pinos, the official residence and working offices of the president, is also on the grounds, buti...

• Venezuela - country.

  Venezuela has six navigable rivers. Of the thousand or more streams in the country, the majority flow into the Orinoco. The Orinoco flows east across central Venezuelaand drains approximately four-fifths of the total area of the country. With the tributaries—the Apure, Meta, and Negro rivers—it forms the outlet into the Atlantic Oceanfor the waters of much of the interior of Colombia, as well as of inland Venezuela. F Climate The climate of Venezuela is tropical on the Llanos and along the coas...