2593 résultats pour "with"

• Astrobiology - astronomy.

  water to help reactions along. American chemists Stanley Miller and Harold Urey tested part of Oparin and Haldane’s hypothesis in the early 1950s by simulating conditions of the early Earth. In whathas become known as the Miller-Urey experiment, the two scientists connected two flasks with a loop of glass tubing that allowed the gases to pass between the flasks.They filled the upper flask with methane, ammonia, and hydrogen—components thought to have been in the early atmosphere. They filled the...

• Church (building) I INTRODUCTION Church (building), a building designed for worship for groups of Christians.

  nearby was a basilica; the two are now combined in one building, known as the Church of the Holy Sepulchre. The original Saint Peter's Basilica in Rome, replaced bythe present church during the Renaissance, was a huge processional basilica with projecting wings—transepts—forming a Latin cross in plan. The domed, centralizedform persisted in the Byzantine and Slavic East, where medieval churches, small in scale, often took the form of five domes arranged on a Greek cross plan. IV MEDIEVAL EUROPE...

• Wireless Communications.

  were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small handheld radio transceivers. Public two-way radios with severalfrequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers,film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children’s toys for years. Most walkie-talkiesb...

• Electric Motors and Generators.

  the armature. It is often desirable to generate as high a voltage as possible, and rotating armatures are not practical in such applications because of the possibility of sparkingbetween brushes and slip rings and the danger of mechanical failures that might cause short circuits. Alternators are therefore constructed with a stationary armaturewithin which revolves a rotor composed of a number of field magnets. The principle of operation is exactly the same as that of the AC generator described,...

• Dentistry.

  Together with dentists, dental hygienists and dental assistants make up the team that provides dental care to patients. Hygienists record patient medical histories, suchas blood pressure and pulse. They clean teeth, apply sealants and fluoride treatments, teach patients sound oral hygiene practices, and often assist with X rays. Manyhygienists receive a two-year associate degree, while others may choose to enroll in a four-year program at a university or in a master’s degree program. There are25...

• Atom - chemistry.

  Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions. A Atomic Number Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral,the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties ofthe atom. The ligh...

• 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...

• Iran-Iraq War - History.

  The Iranian offensives of 1982 set a pattern that continued for the rest of the war. Exploiting their superiority in numbers, Iran sent its Revolutionary Guard on theattack, supported by regular military forces. Outnumbered Iraqi forces inflicted heavy losses on the Iranians but ultimately fell back. As soon as the initial Iranian thrusthad exhausted itself, however, the Iraqi army exploited Iranian disorganization and lack of equipment to retake much of the lost territory. As the war continued,...

• James Madison.

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• James Madison

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• James Madison - USA History.

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• Diseases of Animals.

  infected animal. It may also spread in milk or in garbage that contains contaminated meat. Typical symptoms include blisters that appear on the mouth and feet;animals may become lame when their hooves degenerate. Canine distemper is a highly contagious disease caused by the paramyxovirus, which is transmitted in discharges from the nose and eyes. Symptoms begin with fever,malaise, and nasal and ocular discharges and may progress to convulsions and other nervous system disorders. Parvoviruses aff...

• Obesity.

  of a day, contributing to the development of obesity. V TREATMENTS FOR OBESITY Obesity can become a chronic lifelong condition caused by overeating, physical inactivity, and even genetic makeup. No matter what the cause, however, obesity can beprevented or managed with a combination of diet, exercise, behavior modification, and in severe cases, weight-loss medications and surgery. A Diets The most common and conservative treatment for obesity utilizes a nutritionally balanced, low calorie diet...

• Nicaraguan Revolution.

  Directorate. Within a year Robelo and Violeta Chamorro left the junta, and the Council of State was reorganized to guarantee an overwhelming Sandinista majority.Elections were postponed, restrictions were placed on the media, and relations with the Roman Catholic Church became increasingly tense. Two non-Sandinistasreplaced Robelo and Chamorro on the junta, but they had little power, and the government’s relations with opposition political parties and the private business sectordeteriorated. A D...

• Space Exploration - astronomy.

  to produce 250,000 newtons (56,000 lb) of thrust. The Germans launched thousands of V-2s carrying explosives against targets in Britain and The Netherlands. Whilethey did not prove to be an effective weapon, V-2s did become the first human-made objects to reach altitudes above 80 km (50 mi)—the height at which outer spaceis considered to begin—before falling back to Earth. The V-2 inaugurated the era of modern rocketry. A2 Early Artificial Satellites During the years following World War II, the...

• Horse - biology.

  Horses reach sexual maturity at about one and a half years. The estrous cycle in the mare—a mature female horse—typically lasts 21 days. During the first five days ofthe cycle, the mare is usually receptive to mating. The estrous cycle stops during winter and resumes in the spring, which is the start of the breeding season. Astallion—a mature male horse—approaching a mare in estrus engages in various courtship rituals. These include uttering nickering sounds and sniffing and licking themare’s ge...

• Primate - biology.

  The primate order includes a handful of species that live entirely on meat (carnivores) and also a few that are strict vegetarians (herbivores), but it is composed chieflyof animals that have varied diets (omnivores). The carnivorous primates are the four species of tarsiers, which live in Southeast Asia. Using their long back legs, thesepocket-sized nocturnal hunters leap on their prey, pinning it down with their hands and then killing it with their needle-sharp teeth. Tarsiers primarily eat in...

• 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...

• Joseph Stalin I INTRODUCTION Joseph Stalin (1879-1953), general secretary of the Communist Party

  V FOREIGN POLICIES Although Stalin’s policy in the mid-1930s was to support the Communist International (Comintern) in forming a popular front against the rise of fascism in Europe, hegave up the idea of collective security with the West and in August 1939 decided upon an alliance with Nazi Germany. The “Secret Protocols” of the German-SovietNonaggression Pact carved up Eastern Europe into German and Soviet spheres of influence; the Soviets allowed Germany to invade Poland in exchange for Hitle...

• Joseph Stalin.

  V FOREIGN POLICIES Although Stalin’s policy in the mid-1930s was to support the Communist International (Comintern) in forming a popular front against the rise of fascism in Europe, hegave up the idea of collective security with the West and in August 1939 decided upon an alliance with Nazi Germany. The “Secret Protocols” of the German-SovietNonaggression Pact carved up Eastern Europe into German and Soviet spheres of influence; the Soviets allowed Germany to invade Poland in exchange for Hitle...

• Joseph Stalin .

  V FOREIGN POLICIES Although Stalin’s policy in the mid-1930s was to support the Communist International (Comintern) in forming a popular front against the rise of fascism in Europe, hegave up the idea of collective security with the West and in August 1939 decided upon an alliance with Nazi Germany. The “Secret Protocols” of the German-SovietNonaggression Pact carved up Eastern Europe into German and Soviet spheres of influence; the Soviets allowed Germany to invade Poland in exchange for Hitle...

• Indian Art and Architecture I INTRODUCTION Art on the Indian Subcontinent This map highlights places in India and Pakistan where prominent examples of Indian art and architecture have been produced.

  Sun Temple of KonarakThis 13th-century relief depicting a wheel of the chariot of Indian sun god Surya is situated in the Konarak temple. Thetemple, dedicated to Surya, is situated at Puri in the Gulf of Bengal.Keren Su/Corbis The arts of India expressed in architecture, sculpture, painting, jewelry, pottery, metalwork, and textiles, were spread throughout the Far East with the diffusion ofBuddhism and Hinduism and exercised a strong influence on the arts of China, Japan, Myanmar (formerly known...

• Elementary Particles I INTRODUCTION Structure of Matter Modern physics has revealed successively deeper layers of structure in ordinary matter.

  The most fundamental particles that make up matter fall into the fermion category. These fermions cannot be split into anything smaller. The particles that carry theforces acting on matter and antimatter are bosons called force carriers. Force carriers are also fundamental particles, so they cannot be split into anything smaller.These bosons carry the four basic forces in the universe: the electromagnetic, the gravitational, the strong (force that holds the nuclei of atoms together), and the wea...

• Cuban Revolution.

  Confederation of Labor, threw its support behind Batista. In the same month, the U.S. government cut off weapons sales to Batista’s government. U.S. envoys andpolitical moderates in Cuba tried to convince Batista to leave power peacefully, but Batista refused. Meanwhile, revolutionaries from Castro’s movement and from otherorganizations escalated violent resistance. During the second half of 1958, guerrillas seized ground in the countryside from the army. In the cities, several of Batista’sleadi...

• 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...

• 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...

• Tiger - biology.

  have a simple digestive system designed to process meat so that the nutrients can be readily absorbed into the bloodstream. With the exception of white tigers, which have blue eyes, all tigers have yellow eyes. Tigers mainly use vision to find prey. Although tigers see about as well as humansduring the day, their large eye openings gather more light than do human eyes, making tiger night vision far superior to that of humans. In addition, a special structurein the tiger’s eye, called the tapetu...

• Russian Revolutions of 1917 (Histoire) .

  as Marxists. They believed that the working class—with its struggles to organize trade unions and to bring about political reforms of benefit to the majority ofpeople—would become the primary force for revolutionary change. The Russian Marxists formed the Russian Social Democratic Labor Party (RSDLP) in 1898. By 1903,however, the RSDLP had split into two factions. The faction called the Bolsheviks (from the Russian word for “majority”), led by Vladimir Ilich Lenin, favored a more centralized a...

• Cat. I INTRODUCTION Cat, small, mainly carnivorous animal, Felis silvestris catus, member of

  D Coat Colors The domestic cat's original coat color was probably grayish-brown with darker tabby stripes, a color that provides excellent camouflage in a variety of environments. Allother coat colors and patterns are the result of genetic mutations; for example, solid coat colors such as black and blue are the result of a gene that suppresses tabbystripes; an orange coat is the result of a gene that transforms black pigment to orange; and a solid white coat is the result of a gene that complet...

• Cat - biology.

  D Coat Colors The domestic cat's original coat color was probably grayish-brown with darker tabby stripes, a color that provides excellent camouflage in a variety of environments. Allother coat colors and patterns are the result of genetic mutations; for example, solid coat colors such as black and blue are the result of a gene that suppresses tabbystripes; an orange coat is the result of a gene that transforms black pigment to orange; and a solid white coat is the result of a gene that complet...

• Maya Civilization - history.

  III CLASSIC PERIOD Maya Ruins, El SalvadorThe Maya occupied a large part of Central America, and their civilization reached its height between ad 300 and 900. Many ruins ofthe ancient civilization have been excavated in El Salvador, including huge limestone pyramids.Susan McCartney/Photo Researchers, Inc. Classic Maya civilization became more complex in about AD 300 as the population increased and centers in the highlands and the lowlands engaged in both cooperation and competition with each o...

• Arab-Israeli Conflict.

  the Suez Canal and in 1951 blockaded the Strait of Tiran (Israel’s access to the Red Sea), which Israel regarded as an act of war. In June 1956 Egypt nationalized theSuez Canal, which had been jointly owned by Britain and France. In late October, Israel invaded the Gaza Strip and Sinai Peninsula, defeating Egyptian forces there.Britain and France attacked Egypt a few days later. Although the fighting was brief and Israel eventually withdrew from the Sinai and Gaza, the conflict furtherexacerbate...

• Arab-Israeli Conflict - History.

  the Suez Canal and in 1951 blockaded the Strait of Tiran (Israel’s access to the Red Sea), which Israel regarded as an act of war. In June 1956 Egypt nationalized theSuez Canal, which had been jointly owned by Britain and France. In late October, Israel invaded the Gaza Strip and Sinai Peninsula, defeating Egyptian forces there.Britain and France attacked Egypt a few days later. Although the fighting was brief and Israel eventually withdrew from the Sinai and Gaza, the conflict furtherexacerbate...

• Electronic Music I INTRODUCTION Electronic Music, music that requires the use of electronic devices to produce or manipulate sound during its composition and performance.

  III SYNTHESIZERS AND OTHER ELECTRONIC TECHNOLOGY Moog SynthesizerThe musical synthesizer was invented by American Robert Moog. Soon after Moog introduced an early version in 1964, itbecame known as the “Moog Synthesizer,” and then simply as the “Moog.” Here, Japanese composer Isao Tomita uses aMoog synthesizer in his studio.Huynh Cong/AP/Wide World Photos In the 1950s sound synthesizers were developed, principally in the United States. Synthesizers enabled composers to produce sounds electroni...

• Vincent van Gogh I INTRODUCTION Church at Auvers by Van Gogh Dutch artist Vincent van Gogh spent the last months of his life in Auvers-sur-Oise, near Paris, under the care of Dr.

  III PARIS Van Gogh's Self-PortraitThe burning eyes of this Self-Portrait are an example of how 19th-century Dutch painter Vincent van Gogh attempted tocapture the human essence and emotions of his subjects. During the last several years of his life, van Gogh created anumber of self-portraits. The expressive brushstrokes and vibrant colors in these paintings are typical of this later style.Bridgeman/Art Resource, NY In 1886 van Gogh went to live with Théo in Paris, where he became familiar with...

• William Shakespeare I INTRODUCTION William Shakespeare (1564-1616), English playwright and poet, recognized in much of the world as the greatest of all dramatists.

  Shakespeare’s reputation today is, however, based primarily on the 38 plays that he wrote, modified, or collaborated on. Records of Shakespeare’s plays begin toappear in 1594, when the theaters reopened with the passing of the plague that had closed them for 21 months. In December of 1594 his play The Comedy of Errors was performed in London during the Christmas revels at Gray’s Inn, one of the London law schools. In March of the following year he received payment for two playsthat had been per...

• William Shakespeare.

  Shakespeare’s reputation today is, however, based primarily on the 38 plays that he wrote, modified, or collaborated on. Records of Shakespeare’s plays begin toappear in 1594, when the theaters reopened with the passing of the plague that had closed them for 21 months. In December of 1594 his play The Comedy of Errors was performed in London during the Christmas revels at Gray’s Inn, one of the London law schools. In March of the following year he received payment for two playsthat had been per...

• Medical Ethics.

  medical profession. In recent years, however, the field of medical ethics has struggled to keep pace with the many complex issues raised by new technologies for creating and sustaininglife. Artificial-respiration devices, kidney dialysis, and other machines can keep patients alive who previously would have succumbed to their illnesses or injuries.Advances in organ transplantation have brought new hope to those afflicted with diseased organs. New techniques have enabled prospective parents to con...

• Surrealism I INTRODUCTION Surrealism, artistic and literary movement that explored and celebrated the realm of dreams and the unconscious mind through the creation of visual art, poetry, and motion pictures.

  Hieronymus Bosch’s The Garden of Earthly Delights (about 1505-1510).© 2008 Salvador Dali, Gala-Salvador Dali Foundation / Artists Rights Society (ARS), New York./Bridgeman Art Library, London/New York Dreams, according to Freud, were the royal road to studying the unconscious, because it is in dreams that our unconscious, primal desires manifest themselves. Theincongruities in dreams, Freud believed, result from a struggle for dominance of ego and id. In attempting to access the real workings of...

• Leukemia.

  leukemia, and normal or mildly decreased in chronic lymphocytic leukemia. Nearly all chronic leukemia patients have increased white cell counts. In chronic myelocyticleukemia, some of these leukemic white cells are capable of functioning as normal cells do by fighting infectious microbes. Hence, infection is no more common than in ahealthy individual. In chronic lymphocytic leukemia the blood contains large numbers of malignant lymphocytes that do not function normally. Normal lymphocytescoexist...

• Soccer.

  Two assistants, known as linesmen or referees’ assistants, aid the referee. Their primary job is to alert the referee when balls go out of the playing area and to assist inmaking offsides calls (see Rules section below). The assistants carry flags, which they wave when the ball leaves the playing area or use to point to the spot where a foul was committed. V EQUIPMENT Soccer is played with a round leather ball. It is between 68 and 71 cm (27 and 28 in) in circumference and weighs between 396...

• Chemical Reaction - chemistry.

  Many groups of elements occur so often as ions that they are given names: nitrate, NO 3-; sulfate, SO 42-; and phosphate, PO 43-. The suffix -ate usually indicates the presence of oxygen. The positive ion, NH 4+, is called ammonium, as in NH 4Cl, ammonium chloride, or (NH 4)3PO4, ammonium phosphate. Rules for naming more complicated compounds exist, but many compounds have been given trivial names—for example, Na 2B4O7·10 H 2O, borax—or proprietary names—F(CF 2)nF, Teflon. These nonsystemat...

• Electronics.

  electronic circuits. The resistors are made from carbon mixtures, metal films, or resistance wire and have two connecting wires attached. Variable resistors, with anadjustable sliding contact arm, are often used to control volume on radios and television sets. E Capacitors Capacitors consist of two metal plates that are separated by an insulating material ( see Capacitor). If a battery is connected to both plates, an electric charge will flow for a short time and accumulate on each plate. If th...

• Messier Lifts the Curse.

  Swept up in the hype, the Rangers came out for game five at the Garden in a virtual sleepwalk. By the start of the third period they were down 3-0. New Yorkscratched back to level the score as Messier culminated the three-goal spurt with a wrist shot midway through the period. Vancouver then stunned the Rangers—andthe sellout crowd—by netting three quick goals to put the game far out of reach. Game six in Vancouver proved even more of a challenge for the Rangers. The team showed little will...

• Asteroid - astronomy.

  Asteroids of the S type, related to the stony iron meteorites, make up about 15 percent of the total population of asteroids that can be seen from Earth. Much rarer arethe M-type objects, corresponding in composition to the meteorites known as “irons.” These objects are made up of an iron-nickel alloy and may represent the cores ofbodies that were large enough to differentiate into layers and to melt deep inside. Their rocky outer layers may have been removed by impacts with other asteroids . A...

• Native American Architecture I INTRODUCTION Native American Architecture, traditional architecture of the peoples of who lived in North America before Europeans arrived.

  Mound Builders who resided in the area.John Elk III/Bruce Coleman, Inc. Another mound building culture, named Hopewell, also appears to have originated in Ohio but expanded west to Iowa, Kansas, and Oklahoma, south to Louisiana,Mississippi, and Alabama, east to Georgia and the Appalachian Mountains, and north to Wisconsin, Michigan, and lower Ontario in Canada. The Hopewell culture lastedfrom about 200 BC to 400 AD. Hopewell people built large, linear mounds to create enclosures in geometrical...

• Guinea - country.

  Mining operations in 2004 yielded 16 million metric tons of bauxite, 468,400 carats of high-quality diamonds, and 16,000 kg (35,300 lb) of gold. Environmental concernsand political instability in neighboring Liberia have delayed exploitation of high-grade iron ore from Mount Nimba. In 1999 the national budget included $466 million in revenues and $414 million in expenditures. The unit of currency is the Guinean franc, which is divided into 100 centimes (3,644 francs equal U.S.$1; 2005 average...

• War of 1812 - History.

  the thorough training they received in handling guns was far ahead of contemporary British standards. As hostilities loomed, Congress authorized a regular army of 35,000 men, but when the United States officially declared war in June 1812, the actual land force was lessthan 10,000 and nearly half of these soldiers were raw recruits. The existing troops were also widely scattered in small garrisons. The government planned tosupplement this regular force with 50,000 volunteers and 100,000 militiam...

• War of 1812 - U.

  the thorough training they received in handling guns was far ahead of contemporary British standards. As hostilities loomed, Congress authorized a regular army of 35,000 men, but when the United States officially declared war in June 1812, the actual land force was lessthan 10,000 and nearly half of these soldiers were raw recruits. The existing troops were also widely scattered in small garrisons. The government planned tosupplement this regular force with 50,000 volunteers and 100,000 militiam...