557 résultats pour "found"

• Genetic Engineering.

  Pseudomonas fluorescens bacterium. The genetically altered Pseudomonas fluorescens bacterium produces light in proportion to the amount of its activity in breaking down the naphthalene, thus providing a way to monitor the efficiency of the process ( see Bioremediation). A3 Medicine In 1982 the United States Food and Drug Administration (FDA) approved for the first time the medical use of a recombinant DNA protein, the hormone insulin, whichhad been cloned in large quantities by inserting th...

• Collectibles and Collecting.

  common blond and thus commands a higher price. If there are different variations to a collectible, the least common one is usually worth more. Often there areinteresting stories behind rarities, such as the highly sought-after 1909 Honus Wagner baseball card. At that time tobacco companies manufactured and distributedbaseball cards, and when the antitobacco Wagner complained, his card was pulled from production. Very few copies in good condition have ever been found. C Age Age is often an indic...

• Africa.

  The highest elevations in Africa are found in the various ranges of East Africa. After Kilimanjaro, the next highest peaks are Mount Kenya (5,199 m/17,057 ft), north ofKilimanjaro in central Kenya; Margherita Peak (5,109 m/ 16,762 ft) in the Ruwenzori Range on the border between Uganda and the Democratic Republic of the Congo(DRC); Ras Dashen (4,620 m/ 15,157 ft) in the Ethiopian Highlands of northern Ethiopia; Mount Meru (4,565 m/ 14,977 ft), close to Kilimanjaro in Tanzania; and MountElgon (4,...

• Comparative Anatomy.

  In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...

• 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...

• Christopher Columbus I INTRODUCTION Christopher Columbus (1451-1506), Italian-born Spanish navigator who sailed west across the Atlantic Ocean in search of a route to Asia but achieved fame by making landfall in the Americas instead.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Christopher Columbus.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Christopher Columbus.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Christopher Columbus - explorer.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Whale - biology.

  III BEHAVIOR OF WHALES Studies of whales in captivity have taught scientists much about the complex social behavior of whales. Since the late 1980s, advances in the use of satellite trackingsystems have also broadened opportunities for scientists to observe how whales behave in the wild. A Swimming and Diving Whales swim by making powerful up-and-down movements of the tail flukes, which provide thrust. The power comes from body muscles that flex the lower spine upand down in a wavelike motion...

• Africa.

  The highest elevations in Africa are found in the various ranges of East Africa. After Kilimanjaro, the next highest peaks are Mount Kenya (5,199 m/17,057 ft), north ofKilimanjaro in central Kenya; Margherita Peak (5,109 m/ 16,762 ft) in the Ruwenzori Range on the border between Uganda and the Democratic Republic of the Congo(DRC); Ras Dashen (4,620 m/ 15,157 ft) in the Ethiopian Highlands of northern Ethiopia; Mount Meru (4,565 m/ 14,977 ft), close to Kilimanjaro in Tanzania; and MountElgon (4,...

• Africa - Geography.

  The highest elevations in Africa are found in the various ranges of East Africa. After Kilimanjaro, the next highest peaks are Mount Kenya (5,199 m/17,057 ft), north ofKilimanjaro in central Kenya; Margherita Peak (5,109 m/ 16,762 ft) in the Ruwenzori Range on the border between Uganda and the Democratic Republic of the Congo(DRC); Ras Dashen (4,620 m/ 15,157 ft) in the Ethiopian Highlands of northern Ethiopia; Mount Meru (4,565 m/ 14,977 ft), close to Kilimanjaro in Tanzania; and MountElgon (4,...

• Psychotherapy.

  Other managed-care companies pay therapists a set fee to meet with a client for up to a specified maximum number of sessions depending on the nature of theproblem, free of interference from case reviewers. For example, a managed-care firm may pay a therapist $200 to hold up to eight sessions with a person. If the clientuses all eight sessions, the therapist normally loses money. But if treatment stops after two or three sessions, the therapist makes a profit. This relatively new system iscontrov...

• Louisiana - geography.

  lakes are on the Red River and its tributaries. In addition, small oxbow lakes are numerous in the Mississippi Alluvial Plain. Oxbow lakes are formed when a river cutsthrough the neck of one of its loops, or meanders, thus establishing a shorter course and leaving the former loop as a lake separate from the river. Louisiana also hassome artificially created reservoirs. C Coastline Louisiana’s long and irregular coastline extends along the Gulf of Mexico from the Pearl River on the east to the S...

• Louisiana - USA History.

  lakes are on the Red River and its tributaries. In addition, small oxbow lakes are numerous in the Mississippi Alluvial Plain. Oxbow lakes are formed when a river cutsthrough the neck of one of its loops, or meanders, thus establishing a shorter course and leaving the former loop as a lake separate from the river. Louisiana also hassome artificially created reservoirs. C Coastline Louisiana’s long and irregular coastline extends along the Gulf of Mexico from the Pearl River on the east to the S...

• Texas - geography.

  D Climate Eastern Texas has a humid subtropical climate, while a semiarid low latitude climate prevails in central areas, and an arid low latitude climate in the extreme west. Alongthe coast the climate is much milder, with fewer extremes in temperatures. Hurricanes sometimes hit the coastal areas of Texas from late July through September, andtornadoes are common in north-central Texas in April and May. D1 Temperature Summers are hot throughout the state, and temperatures exceeding 35°C (95°F)...

• Texas - USA History.

  D Climate Eastern Texas has a humid subtropical climate, while a semiarid low latitude climate prevails in central areas, and an arid low latitude climate in the extreme west. Alongthe coast the climate is much milder, with fewer extremes in temperatures. Hurricanes sometimes hit the coastal areas of Texas from late July through September, andtornadoes are common in north-central Texas in April and May. D1 Temperature Summers are hot throughout the state, and temperatures exceeding 35°C (95°F)...

• China - country.

  North China lies between the Mongolian Steppe on the north and the Yangtze River Basin on the south. It stretches west from the Bo Hai gulf and the Yellow Sea to theeastern edge of the Tibetan Plateau. Administratively, North China includes Beijing and Tianjin municipalities; Shandong and Shanxi provinces; most of Hebei, Henan,and Shaanxi provinces; and portions of Ningxia Hui Autonomous Region and of Jiangsu, Anhui, and Gansu provinces. Humans have lived in the agriculturally rich region of Nor...

• Ohio - geography.

  conflict with modified Gulf air and causing frontal or cyclonic storms. Gulf air is dominant in summer. In fall, polar air passing over Lake Erie is modified, delaying thekilling frost along the adjacent shoreline. C1 Temperatures The mean annual temperatures for the state range from 9° C (48° F) in the northeast to 13° C (55° F) in the south. Average January temperatures range from -4° C(24° F) in the west to 2° C (35° F) in the south. July averages are 24° C (76° F) in the south and 23° C (73...

• Ohio - USA History.

  conflict with modified Gulf air and causing frontal or cyclonic storms. Gulf air is dominant in summer. In fall, polar air passing over Lake Erie is modified, delaying thekilling frost along the adjacent shoreline. C1 Temperatures The mean annual temperatures for the state range from 9° C (48° F) in the northeast to 13° C (55° F) in the south. Average January temperatures range from -4° C(24° F) in the west to 2° C (35° F) in the south. July averages are 24° C (76° F) in the south and 23° C (73...

• 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...

• Saudi Arabia - country.

  C Natural Resources Some of the world’s largest oil and natural gas fields lie beneath Saudi Arabia and its offshore waters, representing the country’s most economically important naturalresource. In 2007 Saudi Arabia’s oil reserves were estimated at 264 billion barrels. Before the discovery and exploitation of these reserves in the mid-20th century,Saudi Arabia was one of the poorest countries in the world. Its relatively small population subsisted in a harsh environment with little agricultur...

• 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...

• Nova Scotia - Geography.

  summer. Nova Scotia receives an average of more than 1,140 mm (45 in) of rain annually, with the Atlantic shore receiving 1,400 mm (55 in) or more. Most of the provincereceives about 1,900 mm (about 70 in) of snow, and considerable winter precipitation comes in the form of rain or ice storms. The average temperature in January, thecoldest month, is generally about -4°C (about 25°F) near the coast and somewhat colder toward the interior. The average temperature in July, the hottest month, isabout...

• Nova Scotia - Canadian History.

  summer. Nova Scotia receives an average of more than 1,140 mm (45 in) of rain annually, with the Atlantic shore receiving 1,400 mm (55 in) or more. Most of the provincereceives about 1,900 mm (about 70 in) of snow, and considerable winter precipitation comes in the form of rain or ice storms. The average temperature in January, thecoldest month, is generally about -4°C (about 25°F) near the coast and somewhat colder toward the interior. The average temperature in July, the hottest month, isabout...

• Anthropology.

  humans, such as tools, pottery, and buildings) and human fossils (preserved bones). They also examine past environments to understand how natural forces, such as climate and available food, shaped the development of human culture. Some archaeologists study cultures that existed before the development of writing, a time knownas prehistory . The archaeological study of periods of human evolution up to the first development of agriculture, about 10,000 years ago, is also called paleoanthropology....

• Kansas - geography.

  at the adjoining cities of Kansas City, Kansas, and Kansas City, Missouri. Its chief headstreams are the Republican and Smoky Hill rivers, which join to form the KansasRiver at Junction City. Each of the headstreams has numerous tributaries. The Kansas River proper is only 270 km (170 mi) long, but the Smoky Hill River has a lengthof 870 km (540 mi), and the Republican River has a length of 720 km (450 mi). The main tributary flowing into the Kansas River is the Big Blue River. The Arkansas Rive...

• Kansas - USA History.

  at the adjoining cities of Kansas City, Kansas, and Kansas City, Missouri. Its chief headstreams are the Republican and Smoky Hill rivers, which join to form the KansasRiver at Junction City. Each of the headstreams has numerous tributaries. The Kansas River proper is only 270 km (170 mi) long, but the Smoky Hill River has a lengthof 870 km (540 mi), and the Republican River has a length of 720 km (450 mi). The main tributary flowing into the Kansas River is the Big Blue River. The Arkansas Rive...

• Italy - country.

  C Natural Resources Italy is poor in natural resources. Much of the land is unsuitable for agriculture because of mountainous terrain or unfavorable climate. Italy, moreover, lacks substantialdeposits of basic natural resources such as coal, iron, and petroleum. Natural gas is the country’s most important mineral resource. Other deposits include feldspar andpumice. Many of Italy’s mineral deposits on the islands of Sicily and Sardinia had been heavily depleted by the early 1990s. Italy is rich...

• Biblical Archaeology.

  religion, among them the storm deity Baal (title of Hadad) mentioned frequently in the Old Testament. Moreover, the poetry of Ugarit has strong affinities with that ofthe Bible. They share much in the way of vocabulary, structure, and the use of figures of speech and other literary devices. In 1945, at ancient Naj‘Ḩamm ād ī in Upper Egypt, some 50 Gnostic writings in Coptic were discovered. They could be dated to the 4th century AD, but investigation of their character and content showed that t...

• Nanotechnology.

  ever-finer method of reducing material to the nanoscale size. Instead, nanostructures would be assembled atom by atom and molecule by molecule, from the atomiclevel up, just as occurs in nature. However, assembly at this scale has its own challenges. In school, children learn about some of these challenges when they study the random Brownian motion seen in particles suspended in liquids such as water. Theparticles themselves are not moving. Rather, the water molecules that surround the particles...

• Environment.

  escape into space of the infrared energy radiated back out by Earth. This process is referred to as the greenhouse effect. These gases, primarily carbon dioxide,methane, nitrous oxide, and water vapor, insulate Earth’s surface, helping to maintain warm temperatures. Without these gases, Earth would be a frozen planet with anaverage temperature of about -18°C (about 0°F) instead of a comfortable 15°C (59°F). If the concentration of these gases rises, they trap more heat within theatmosphere, caus...

• French Canadian Nationalism - Canadian History.

  The revolution ended in independence for the Americans, who named their new country the United States of America. In the aftermath, thousands of people who hadopposed the American Revolution migrated from what was now the United States to British North America. These people, known as the United Empire Loyalists, settledin the Maritimes, where they greatly increased the British majority over the Acadians, and in Québec. Some settled near francophone communities around Montréal andin the Eastern T...

• Woodrow Wilson.

  daughters. In 1885 Wilson also accepted a position with the newly opened Bryn Mawr College, a school for women near Philadelphia. Wilson was not particularly patient with womenas intellectual associates and did not enjoy his teaching duties. He was, however, able to pursue his writing. A University Professor In 1888 Wilson left Bryn Mawr for a professorship in history and political economy at Wesleyan University in Connecticut. There, in 1889, he published The State, a lengthy textbook analyz...

• Woodrow Wilson

  daughters. In 1885 Wilson also accepted a position with the newly opened Bryn Mawr College, a school for women near Philadelphia. Wilson was not particularly patient with womenas intellectual associates and did not enjoy his teaching duties. He was, however, able to pursue his writing. A University Professor In 1888 Wilson left Bryn Mawr for a professorship in history and political economy at Wesleyan University in Connecticut. There, in 1889, he published The State, a lengthy textbook analyz...

• Northwest Territories - Geography.

  million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...

• Northwest Territories - Canadian History.

  million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...

• Trigonometry I INTRODUCTION Trigonometry, branch of mathematics that deals with the relationships between the sides and angles of triangles and with the properties and applications of the trigonometric functions of angles.

  If point P, in the definition of the general trigonometric function, is on the y-axis, x is 0; therefore, because division by zero is inadmissible in mathematics, the tangent and secant of such angles as 90°, 270°, and -270° do not exist. If P is on the x-axis, y is 0; in this case, the cotangent and cosecant of such angles as 0°, 180°, and - 180° do not exist. All angles have sines and cosines, because r is never equal to 0. Since r is greater than or equal to x or y, the values of si...

• Aegean Civilization .

  warlike. The styles are also more formal and geometric than those of earlier examples, anticipating the art of classical Greece. A typical Mycenaean city had, at its center, the fortress palace of the king. The cities were fortified with massive structures of unevenly cut stones, known as Cyclopeanwalls. The Linear B tablets from this time include names of Greek gods, such as Zeus, and contain detailed records of royal possessions. The gold masks, weapons, andjewelry found by Schliemann at the r...

• Aegean Civilization - USA History.

  warlike. The styles are also more formal and geometric than those of earlier examples, anticipating the art of classical Greece. A typical Mycenaean city had, at its center, the fortress palace of the king. The cities were fortified with massive structures of unevenly cut stones, known as Cyclopeanwalls. The Linear B tablets from this time include names of Greek gods, such as Zeus, and contain detailed records of royal possessions. The gold masks, weapons, andjewelry found by Schliemann at the r...

• 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...

• Manitoba - Geography.

  E Plant Life Forests cover 66 percent of Manitoba. The main forest area is divided into the boreal forest and the mixed-wood forest. The boreal, or northern, forest containsconiferous (cone-bearing) trees, especially white and black spruce, balsam fir, and jack pine. South of the boreal forest is the mixed-wood forest, which contains conifers as well as such deciduous trees as white birch, aspen, poplar, and Manitoba maple. Prairie land is found in the southwest, where the natural vegetation i...

• Manitoba - Canadian History.

  E Plant Life Forests cover 66 percent of Manitoba. The main forest area is divided into the boreal forest and the mixed-wood forest. The boreal, or northern, forest containsconiferous (cone-bearing) trees, especially white and black spruce, balsam fir, and jack pine. South of the boreal forest is the mixed-wood forest, which contains conifers as well as such deciduous trees as white birch, aspen, poplar, and Manitoba maple. Prairie land is found in the southwest, where the natural vegetation i...

• Antarctica - Geography.

  The maximum area of sea ice surrounding Antarctica each winter varies from year to year. A marked decline during the 1970s appears to have reversed in more recentdecades, except in the Antarctic Peninsula area. This area has lost almost 40 percent of its sea ice since the start of the 1980s. Sea ice is important to marine life. Krillfeed on algae that live under the sea ice and are released when the ice melts in spring and summer. In turn, many marine animals feed on krill. Emperor penguinsbreed...

• Agatha Christie

  b. Miss Jane Marple : Miss Jane Marple, another famous character of the work of Agatha Christie appeared in 1930 in the novel The Murder at the Vicarage "and continue his career until 1979, having starred in a dozen novels inwhich it solves the murders of the most interesting as those "train from 16h50" or "At Bertram's Hotel". It is already old when it was discovered in the first book but that did not stop carrying out its various investigations. She leads a quiet life of single hardened in...

• Smoking.

  causes about 20 times the number of deaths in the United States than all other addictive drugs combined. Smoking cessation methods are plentiful, and many books and products are available to help an individual stop smoking. Many smokers turn to group help because ofthe support and understanding provided by other former smokers or people trying to quit. Most successful group-help techniques involve a challenge and rewardsystem that also bolsters the self-discipline of the former smoker. A number...

• Eagle - biology.

  States, is a member of this group found only in North America. It is named for its snow-white head. However, the name bald does not refer to a lack of feathers but comes instead from an outdated word meaning marked with white, as in piebald. The adult bald eagle is blackish brown, with a white head and tail. Its bill, legs, and feet are bright yellow. The bill, which is longer and heavier than the gray bill of golden eagles, is useful for piercing the skin of fish. Bald eagles vary in size....

• Hydrogen - chemistry.

  Hydrogen gas does not usually react with other chemicals at room temperature. That is, it does not split into two hydrogen atoms to combine with other chemicals. Thebond between the hydrogen atoms is very strong and can only be broken with a large amount of energy. However, when heated with a flame or a spark, hydrogen gaswill react violently with oxygen in the air to produce water in the following reaction: 2H2 + O 2 → 2H 2O This chemical equation shows that two hydrogen molecules (H 2) and o...

• Volcano.

  before eruption. Very violent explosive eruptions are called Plinian eruptions, after Roman naturalist Pliny the Elder. These eruptions can last for several hours to daysand eject a large amount of pyroclastic material. Some volcanoes can produce much more energetic eruptions that eject materials farther from the vents because oftheir andesitic and dacitic composition. Andesitic and dacitic lava is generally thicker than basaltic lava. Stiff lava generally produces more-explosive eruptions. B No...

• Colombia - country.

  In Bogotá the average high temperature in January is 20°C (68°F), and in July the average high is 19°C (65°F). The highs for the same months in Barranquilla are 32°C(89°F) and 33°C (91°F). Throughout the year, three-month periods of rain and dry weather alternate. Along the Pacific coast precipitation is heavy. At Bogotá the annual rainfall averages about1,060 mm (about 42 in), and in Barranquilla it averages about 800 mm (about 32 in). Dry weather prevails on the slopes of the Cordillera Orient...