460 résultats pour "less"

• Zelus (Zelos; Zeal, Strife) Greek The personification of rivalry, envy, jealousy, and eagerness; a demigod or lesser god; son of the Titan Pallas and the water Nymph Styx; brother of Nike (Victory), Bia (Force), and Cratus (Strength).

• Birds.

  Birds need much less sleep than people do. One seabird, called the sooty tern, can fly for years bytaking “naps” that last only a few seconds. Most birds that live on land are active during the day and sleep at night. Owls are just the opposite.They sleep during the day and hunt at night. Birds usually sleep in shrubs, on tree branches, in holes in trees, or on the ground. Most ducks sleep onthe water. Many birds sleep while they are standing. MATING AND BREEDING Many kinds of birds have only on...

• From Sir Gawain and the Green Knight - anthology.

  And she urged it on him eagerly, and ever he refused,And vowed in very earnest, prevail she would not.And she sad to find it so, and said to him then,“If my ring is refused for its rich cost -You would not be my debtor for so dear a thing—I shall give you my girdle; you gain less thereby.”She released a knot lightly, and loosened a beltThat was caught about her kirtle, the bright cloak beneath,Of a gay green silk, with gold overwroght,And the borders all bound with embroidery fine,And this she p...

• Poverty.

  economic and demographic trends, and (7) welfare incentives. A Overpopulation Overpopulation, the situation of having large numbers of people with too few resources and too little space, is closely associated with poverty. It can result from highpopulation density (the ratio of people to land area, usually expressed as numbers of persons per square kilometer or square mile) or from low amounts of resources, or from both. Excessively high population densities put stress on available resources....

• Silk Road - History.

  and high in value because they were carried on the backs of the limited number of camels in each caravan. Thus, of necessity they were luxury items, not bulky rawmaterials or essential goods for daily use. The oases and towns along the route, which were located in or near remote areas, profited from the Silk Road trade and reliedon it for their existence. The great empires of Persia, China, and Rome, however, could easily have survived without the commerce in luxury goods. V SPREAD OF RELIGION A...

• Internal-Combustion Engine.

  any Otto-cycle engine and in actual engines today is slightly more than 40 percent. Diesels are, in general, slow-speed engines with crankshaft speeds of 100 to 750revolutions per minute (rpm) as compared to 2500 to 5000 rpm for typical Otto-cycle engines. Some types of diesel, however, have speeds up to 2000 rpm. Becausediesels use compression ratios of 14 or more to 1, they are generally more heavily built than Otto-cycle engines, but this disadvantage is counterbalanced by theirgreater effici...

• Global Warming.

  some of the warming influence of increasing greenhouse gases. A1 Carbon Dioxide Carbon dioxide is the second most abundant greenhouse gas, after water vapor. Carbon dioxide constantly circulates in the environment through a variety of naturalprocesses known as the carbon cycle. It is released into the atmosphere from natural processes such as eruptions of volcanoes; the respiration of animals, whichbreathe in oxygen and exhale carbon dioxide; and the burning or decay of plants and other organic...

• Political Parties.

  In both Britain and the United States, competition between political parties undermined traditional conceptions of politics rooted in classical and Christian notions ofvirtue and public service. According to this tradition, political leaders should act according to a model of virtue that involved placing the common good above theinterests of a fraction of the society. Leaders acting to benefit only themselves or a narrow portion of the society were considered corrupt. However, party competitionr...

• Black Death.

  disappeared in the West. V DISAPPEARANCE OF PLAGUE Plague became less common in Europe after the 1530s. The last plague in England was in 1665, the last in Western Europe in 1722. Numerous theories have beenoffered to explain the disappearance of plague. It has been argued that black rats, the primary carriers of plague, may have been replaced by larger brown rats that donot carry the infection. A second theory suggests that increased immunity among the rodents that carried the disease or chang...

• Black Death .

  disappeared in the West. V DISAPPEARANCE OF PLAGUE Plague became less common in Europe after the 1530s. The last plague in England was in 1665, the last in Western Europe in 1722. Numerous theories have beenoffered to explain the disappearance of plague. It has been argued that black rats, the primary carriers of plague, may have been replaced by larger brown rats that donot carry the infection. A second theory suggests that increased immunity among the rodents that carried the disease or chang...

• 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...

• Antibiotics.

  In some species of bacteria the cell wall consists primarily of a thick layer of peptidoglycan. Other species have a much thinner layer of peptidoglycan and an outer aswell as an inner membrane. When bacteria are subjected to Gram's stain, these differences in structure affect the differential staining of the bacteria with a dye calledgentian violet. The differences in staining coloration (gram-positive bacteria appear purple and gram-negative bacteria appear colorless or reddish, depending on t...

• Hurricane.

  V HOW HURRICANES ARE DETECTED AND MONITORED Since 1943 U.S. military and civilian aircraft have been flying into hurricanes to measure wind velocities and directions, the location and size of the eye, air pressures,and temperatures in different parts of the storm. A coordinated system of tracking hurricanes was developed in the mid-1950s, and steady improvements have beenmade over the years. In addition to reports from aircraft, geosynchronous weather satellites (since 1966) and ocean buoys tha...

• Helicopter.

  naturally flaps down so as to increase lift. Flapping allows the differences in lift caused by uneven rotor tip speed to cancel out, producing a stable ride. Many helicoptersuse mechanical hinges with lubricated bearings, but some use flexible straps made of a composite material in order to reduce the required maintenance. Helicopters require different amounts of lift and thrust at different times during flight, because the aerodynamic forces acting on them change during hovering andacceleration...

• Astronaut - astronomy.

  Every operation during a flight is important and interesting, but many might be boring to an observer. Much of an astronaut’s job is entering computer instructions,preparing samples, making measurements, recording data, fixing what breaks, and adjusting the checklist when something unexpected happens. Sometimes astronautsretrieve or repair satellites, rendezvous or dock with other spacecraft, and do important emergency repairs. The adaptability of the human crew is crucial to the successof missi...

• South America - Geography.

  South America is dominated by relatively warm climatic regimes. Spanning nearly the entire continent along the equator is a belt of humid tropical climate that grades tothe north and south into broad zones where the length of the rainy season and the amount of rainfall diminish. These zones have wet summers and dry winters and aresubject to prolonged droughts. Droughts are a particularly serious problem in northeastern Brazil and along the northern coast of Venezuela and Colombia. The areas ofra...

• Hong Kong - geography.

  higher than China’s average standard of living. In 2006 Hong Kong’s per capita gross domestic product (GDP) was $27,679.20, although much of the wealth isconcentrated into relatively few hands. IV ECONOMY Hong Kong’s position as one of the world’s most important economic centers is based on several factors. It is located midway between Japan and Singapore, and it liesastride the main shipping and air routes of the western Pacific. It also has long served as a major port of entry and trade for...

• Saturn - astronomy.

  measurements of the magnetic field made by the Voyager space probes in the 1980s. Additional Cassini findings reported in March 2007 suggested that particles originating from geysers on the moon Enceladus may provide a partial explanation for thechange. The neutral gas particles become electrically charged and are captured by Saturn’s magnetic field, forming a disk of hot, ionized gas around the planet’sequator. The charged particles interact with the magnetic field and slow down the rotation of...

• Elephant - biology.

  B Trunk An elephant's nose and upper lip are combined in a long, limber trunk, an exceptionally supple appendage with an estimated 150,000 muscles. The versatile trunk actslike a hand for grasping low-growing shrubs and other food and placing it into the mouth; an arm for breaking off tree branches; or a snorkel for breathing when theelephant's body is submerged. Elephants also use their trunks to suck up water and squirt it into their mouths for drinking or over their bodies for bathing. Nostr...

• Spread of Islam - History.

  Muhammad died in 632 and was succeeded by Abu Bakr, the father of Muhammad’s favorite wife, Aisha. Abu Bakr was the first caliph ( khalifah, Arabic for “successor”) of Islam. Like Muhammad, Abu Bakr was a member of the Quraysh clan. While neither Abu Bakr nor any subsequent caliph claimed the role of prophet, they wereleaders of this new religious enterprise that was quickly becoming a political entity as well. The first four caliphs, all of whom were selected by some form of council ofMuslims,...

• Electoral College.

  III HISTORY OF THE ELECTORAL COLLEGE A Origins One thing is clear about the political theory underpinning the electoral college: The framers of the Constitution could not agree on one. From the outset, the framerswere uncertain about how the president should be chosen. Meeting in the Constitutional Convention in Philadelphia, Pennsylvania, in 1787, the framers originally decidedto have Congress choose the president, and that there should be no popular vote to elect the president. Then the Con...

• Swimming.

  the swimmer and the pinky finger should enter the water first. At the same time, the swimmer moves the left arm through the water below the left side of the body.Once in the water, the right arm begins pulling the swimmer forward by bending at the elbow. At the same time the swimmer holds the left arm straight as it reachesthe hip and lifts it out of the water. As the right arm continues to pull, the swimmer rotates slightly onto the right side and swings the left arm up above the head. As the s...

• Ghana - country.

  times of depressed cacao prices, Ghana has significantly increased exports of timber to generate needed revenue. In 1988 Ghana initiated a conservation plan called the Forest Resource Management Project. In 1989 Ghana restricted the export of 18 tree species, and in 1994 thecountry banned the export of raw logs. About 4.8 percent (1997) of the country’s land is officially protected, but illegal logging threatens Ghana’s remaining forests. Deforestation, overgrazing, and periodic drought have led...

• 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...

• Kazakhstan - country.

  mismanagement. Between 1949 and 1991 the Soviet government conducted about 70 percent of all of its nuclear testing in Kazakhstan, mostly in the northeastern area near the city ofSemipalatinsk (now Semey). Nearly 500 nuclear explosions occurred both above and below ground near Semipalatinsk, while more than 40 nuclear detonationsoccurred at other testing grounds in western Kazakhstan and in the Qyzylqum desert. More than 1 million of Kazakhstan’s inhabitants were exposed to dangerous levelsof ra...

• Quantum Theory I INTRODUCTION Quantum Theory, in physics, description of the particles that make up matter and how they interact with each other and with energy.

  electron in the same way a particle with momentum would: It bumps the electron and changes the electron’s path. The light is also affected by the collision as though itwere a particle, in that its energy and momentum changes. Momentum is a quantity that can be defined for all particles. For light particles, or photons, momentum depends on the frequency, or color, of the photon, which in turndepends on the photon’s energy. The energy of a photon is equal to a constant number, called Planck’s cons...

• Kentucky - geography.

  The climate of Kentucky is characterized by warm or hot summers and cool winters. Throughout the year, temperatures do not vary greatly from place to place,although they are generally slightly lower in the Appalachian Plateaus region than elsewhere in the state. Average July temperatures are usually from 24° to 27°C (76°to 80°F) in the central and western areas and from 23° to 24°C (74° to 76°F) in the east. January averages range from below 1°C (34°F) in the northern Bluegrassregion to more tha...

• Kentucky - USA History.

  The climate of Kentucky is characterized by warm or hot summers and cool winters. Throughout the year, temperatures do not vary greatly from place to place,although they are generally slightly lower in the Appalachian Plateaus region than elsewhere in the state. Average July temperatures are usually from 24° to 27°C (76°to 80°F) in the central and western areas and from 23° to 24°C (74° to 76°F) in the east. January averages range from below 1°C (34°F) in the northern Bluegrassregion to more tha...

• United States History - U.

  and improved upon the designs of Arab sailing ships and learned to mount cannons on those ships. In the 15th century they began exploring the west coast ofAfrica—bypassing Arab merchants to trade directly for African gold and slaves. They also colonized the Madeira Islands, the Azores, and the Cape Verde Islands andturned them into the first European slave plantations. The European explorers were all looking for an ocean route to Asia. Christopher Columbus sailed for the monarchs of Spain in 149...

• United States History - U.

  and improved upon the designs of Arab sailing ships and learned to mount cannons on those ships. In the 15th century they began exploring the west coast ofAfrica—bypassing Arab merchants to trade directly for African gold and slaves. They also colonized the Madeira Islands, the Azores, and the Cape Verde Islands andturned them into the first European slave plantations. The European explorers were all looking for an ocean route to Asia. Christopher Columbus sailed for the monarchs of Spain in 149...

• 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...

• Japan - country.

  island’s fertile soils support agriculture and provide the vast majority of Japan’s pasturelands. In addition, Hokkaidō contains coal deposits, and the cold currents off itsshores supply cold-water fish. Winters are long and harsh, so most of Hokkaid ō is lightly settled, housing about 5 percent of Japan’s population on approximately 20 percent of its land area. However,its snowy winters and unspoiled natural beauty attract many skiers and tourists. Hokkaid ō is thought of as Japan’s northern fr...

• Automobile.

  Electric motors have been used to power automobiles since the late 1800s. Electric power supplied by batteries runs the motor, which rotates a driveshaft, the shaftthat transmits engine power to the axles. Commercial electric car models for specialized purposes were available in the 1980s. General Motors Corporation introduced amass-production all-electric car in the mid-1990s. Automobiles that combine two or more types of engines are called hybrids. A typical hybrid is an electric motor with ba...

• Spain - country.

  B Natural Resources Spain has a number of mineral resources. The largest known deposits are of iron ore, zinc, and lead. Spain also produces significant quantities of copper and mercury.These deposits are mined mainly in Huelva province in southwestern Spain, around Cartagena on the Mediterranean, and at various points along the Bay of Biscay inthe north. Additionally, uranium is mined in the region of Extremadura, near the Portuguese frontier, where pyrites, fluorspar, gypsum, tungsten, and po...

• Nunavut - Canadian History.

  The Arctic Lands is a complex geological area that is centered on the Arctic Ocean. It includes coastal plains, plateaus, and mountains. Coastal plains and plateaus arefound in the western Northwest Territories section of the Arctic Lands, such as on Victoria Island, which is mostly a large, flat plateau. In striking contrast to theserelatively gentle landscapes, the eastern Nunavut section of the Arctic Lands is dominated by a jagged chain of ice-covered mountains. The mountains on EllesmereIsl...

• Pennsylvania - geography.

  B Rivers and Lakes There are three major river basins in Pennsylvania: the Susquehanna, the Ohio, and the Delaware. Together they drain more than 90 percent of Pennsylvania’s landarea. Most of eastern and central Pennsylvania is drained by the Susquehanna and Delaware systems. The western part of the state is drained by the Allegheny andMonongahela rivers, which join at Pittsburgh to form the Ohio. In addition to the three major river basins, short streams flowing into Lake Erie drain the north...

• Pennsylvania - USA History.

  B Rivers and Lakes There are three major river basins in Pennsylvania: the Susquehanna, the Ohio, and the Delaware. Together they drain more than 90 percent of Pennsylvania’s landarea. Most of eastern and central Pennsylvania is drained by the Susquehanna and Delaware systems. The western part of the state is drained by the Allegheny andMonongahela rivers, which join at Pittsburgh to form the Ohio. In addition to the three major river basins, short streams flowing into Lake Erie drain the north...

• American Civil War.

  free state to keep the balance in the Senate. It also provided that slavery would be excluded from the still unorganized part of the Louisiana Territory. A line was drawnfrom Missouri’s southern boundary, at the latitude of 36°30’, and slavery would not be allowed in the territory north of that line,with the exception of Missouri. B Compromise of 1850 Agitation against slavery continued in the North. The South reacted by defending it ever more strongly. The Mexican War, by which the United Stat...

• American Civil War - U.

  free state to keep the balance in the Senate. It also provided that slavery would be excluded from the still unorganized part of the Louisiana Territory. A line was drawnfrom Missouri’s southern boundary, at the latitude of 36°30’, and slavery would not be allowed in the territory north of that line,with the exception of Missouri. B Compromise of 1850 Agitation against slavery continued in the North. The South reacted by defending it ever more strongly. The Mexican War, by which the United Stat...

• Europe .

  D Vegetation Although much of Europe, particularly the west, was originally covered by forest, the vegetation has been transformed by human habitation and the clearing of land.Only in the most northerly mountains and in parts of north central European Russia has the forest cover been relatively unaffected by human activity. On the otherhand, a considerable amount of Europe is covered by woodland that has been planted or has reoccupied cleared lands. The largest vegetation zone in Europe, cuttin...

• Europe - Geography.

  D Vegetation Although much of Europe, particularly the west, was originally covered by forest, the vegetation has been transformed by human habitation and the clearing of land.Only in the most northerly mountains and in parts of north central European Russia has the forest cover been relatively unaffected by human activity. On the otherhand, a considerable amount of Europe is covered by woodland that has been planted or has reoccupied cleared lands. The largest vegetation zone in Europe, cuttin...

• 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...

• Africa - history.

  Africa’s other major mountainous regions occur at the northern and southern fringes of the continent. The Atlas Mountains, a system of high ranges, extend for 2,200 km(1,400 mi) across Morocco, Algeria, and Tunisia, roughly parallel to the northern coast. These ranges enclose a number of broad inland basins and plateaus. In the west, theHigh (or Grand) Atlas contains Toubkal (4,165 m/ 13,665 ft), the highest peak of the system. Toward the east, the Atlas consists of two parallel ranges: the Tell...

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

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

• Evolution - biology.

  genetic diversity to extinction. Sexual reproduction ensures that the genes in a population are rearranged in each generation, a process termed recombination. Although the combinations of genes inindividuals change with each new generation, the gene frequency, or ratio of different alleles in the entire population, remains relatively constant if no evolutionaryforces act on the population. One such force is the introduction of new genes into the genetic material of the population, or gene pool...

• Marriage.

  In many traditional societies, marriage typically involved transfers of property from the parents to their marrying children or from one set of parents to the other. Thesecustoms persist in some places today and are part of the tradition of arranged marriages. For example, in some cultures the bride’s parents may give property (knownas a dowry) to the new couple. The practice of giving dowries has been common in countries such as Greece, Egypt, India, and China from ancient times until thepresen...

• 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...

• English Literature I INTRODUCTION English Literature, literature produced in England, from the introduction of Old English by the Anglo-Saxons in the 5th century to the present.

  evident. That feature is typical of other Old English literature, for almost all of what survives was preserved by monastic copyists. Most of it was actually composed byreligious writers after the early conversion of the people from their faith in the older Germanic divinities. Sacred legend and story were reduced to verse in poems resembling Beowulf in form. At first such verse was rendered in the somewhat simple, stark style of the poems of Caedmon, a humble man of the late 7th century who w...