2538 résultats pour "area"

• 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...

• Plate Tectonics.

  ridges. The Mid-Atlantic Ridge is an underwater mountain range created at a divergent plate boundary in the middle of the Atlantic Ocean. It is part of a worldwidesystem of ridges made by seafloor spreading. The Mid-Atlantic Ridge is currently spreading at a rate of 2.5 cm per year (1 in per year). The mid-ocean ridges today are60,000 km (about 40,000 mi) long, forming the largest continuous mountain chain on earth. Earthquakes, faults, underwater volcanic eruptions, and vents, oropenings, along...

• Prints and Printmaking I INTRODUCTION Prints and Printmaking, pictorial images that can be inked onto paper, and the art of creating and reproducing them.

  Bewick’s The SkylarkBritish engraver Thomas Bewick’s The Skylark is part of his History of British Birds (2 vols., 1797 and 1804). Bewick wasthe first artist to demonstrate the full potential of wood engraving and is renowned for his fine natural history illustrations.Each illustration shows some of the bird’s natural habitat.Folio Society, London/Bridgeman Art Library, London/New York Historically, the wood engraving was chiefly used for illustrations in magazines and books. It is similar to th...

• Lebanon (country) - country.

  during the civil war. Within the country, thousands of Shia Muslim refugees fled fighting in southern Lebanon in the 1990s and moved into shantytowns in Beirut’ssouthern suburbs. Lebanon’s major cities were greatly affected by the civil war. Beirut has gradually regained most of its prewar population and remains the country’s largest city. Tripoli,the northern port, is the second largest city. Jūniyah, north of Beirut, was developed as a wartime port and subsequently had a population boom. Za ḩl...

• Television.

  A charge-coupled device (CCD) can be much smaller than a camera tube and is much more durable. As a result, cameras with CCDs are more compact and portablethan those using a camera tube. The image they create is less vulnerable to distortion and is therefore clearer. In a CCD, the light from a scene strikes an array ofphotodiodes arranged on a silicon chip. Photodiodes are devices that conduct electricity when they are struck by light; they send this electricity to tiny capacitors. Thecapacitors...

• Dogsledding.

  Mushers are caretakers, but also coaches. Top mushers have large kennels, and their preparation for competition begins by buying and breeding race-specific dogs.They train their dogs, decide which to run on certain days, and make adjustments during races by switching and dropping dogs. Serious competitors run their dogsyear-round, using carts and all-terrain vehicles when there is not enough snow on the ground. During races they decide their strategy, choosing when to rest and whento push ahead....

• Desert - geography.

  from the rain shadow produced by the Sierra Nevada. Other desert areas in the interiors of some continents have formed because the prevailing winds are far removed from large bodies of water and have lost much of theirmoisture by the time they reach those regions. Such deserts are the Gobi and Turkistan of Eurasia. Gobi DesertThe largest desert in Asia, the Gobi straddles the border between Mongolia and China. It contains a series of basins that are dividedby low, flat-topped ranges and isolated...

• Automobile Racing.

  beginning in 1906 at Le Mans it came to refer to the principal F1 auto race in a given nation, except in the United States, where the term continues to be used lessdiscriminately. After the end of World War I in 1918, when automobile racing blossomed internationally, a series of GP races in several nations became reserved for F1competition, and an annual GP calendar was developed consisting of national races, such as the French Grand Prix and the British Grand Prix. An annual award calledthe Wor...

• Kenya - country.

  threatens fish and other water life in the lake by depriving them of oxygen. Kenya is well known for its game parks—including Masai Mara Game Park and Tsavo National Park in the south, and Marsabit National Reserve in the north—whichattract large numbers of tourists and much revenue. Conservation of wildlife within reserves has thus received high priority. About 13 percent (2007) of Kenya’s totalland is protected. There are 229 (2004) threatened species in Kenya. Threatened habitats include the...

• Mountain Climbing.

  teeth on one side, and a straight, flat, metal blade called an adze on the other. Ice axes have many uses. One of the most common is to help the climber stay balanced on steep slopes. The climber swings the axe with a short, quick movement to lodge the pick in snow or ice, creating a secure anchor. If a climber should slip and beginsliding down a snowfield, a self-arrest can be performed by turning face down on the snow and burying the pick in the snow surface. The climber’s weight over the...

• 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...

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

  frequency, column (d), is the ratio of the frequency of an interval to the total count; the relative frequency is multiplied by 100 to obtain the percent relative frequency.The cumulative frequency, column (e), represents the number of students receiving grades equal to or less than the range in each succeeding interval; thus, thenumber of students with grades of 30 or less is obtained by adding the frequencies in column (c) for the first three intervals, which total 53. The cumulative relativef...

• Vietnam - country.

  E Natural Resources Vietnam’s most valuable natural resource is its land, particularly the fertile, alluvial soils in the Red and Mekong deltas. Some 29 percent of the land is currently beingcultivated. Vietnam has some valuable mineral resources, including gold, iron, tin, zinc, phosphate, chromite, apatite, and anthracite coal. Most deposits are located in the northernpart of the country. Few attempts were made to extract these minerals until the French takeover of Vietnam at the end of the 1...

• North America - Geography.

  D Climate Although North America has considerable climatic variety, five principal climatic regions can be identified. The northern two-thirds of Canada and Alaska, as well as all ofGreenland, have subarctic and arctic climates, in which long, dark, bitterly cold winters alternate with brief, mild summers. Most of the region, which receives relativelylittle precipitation, is covered with snow and ice during much of the year. A second climatic region is made up of the eastern two-thirds of the U...

• Comedy

  Socrates suffered in the comedy of Aristophanes. Throughout history, opposition to comedy and laughter has been strongest in societies which emphasize physical restraint, decorum and conformity. Many medieval monastic orders had statutes forbidding laughter. The Puritan and Victorian eras saw many condemnations of comedy and laughter. The more authoritarian the regime, the greater its suppression of comedy. Hitler even set up ‘joke courts' to punish those who made fun of his regime - one Berl...

• Puzzle.

  Visual puzzles involve searching a picture to find hidden or disguised figures or answering a question about some part of a visual illusion. For instance, the popular 19th- century prints of American lithographic company Currier & Ives featured hidden people, animals, and other objects. A 16th-century painting from Bukhara, Uzbekistan,of a camel includes hidden figures of 17 people, 10 rabbits, a monkey, and a dragon (Metropolitan Museum of Art, New York City). B Mathematical Puzzles and Logic...

• Turbine.

  steam turbine has supplanted the reciprocating engine as a prime mover in large electricity-generating plants and is also used as a means of jet propulsion. Steam turbines are used in the generation of nuclear power and in nuclear ship propulsion. They operate with fuel-fired boilers for power generation. In cogenerationapplications requiring both process heat (heat used in an industrial process) and electricity, steam is raised at high pressure in the boiler and extracted from the turbineat th...

• Honolulu - geography.

  of Brigham Young University. The state’s largest museum, the Bernice Pauahi Bishop Museum, is located in Honolulu. It contains a large collection of Polynesian archaeological artifacts, as well asmany exhibits on Hawaiian history and culture. The museum also has an extensive entomological collection with more than 13 million specimens. Other importantmuseums include the Honolulu Academy of Arts, known for its extensive collection of Japanese, Chinese, and Korean art; the Contemporary Museum, wit...

• Detroit - geography.

  of German and Irish immigrants. In the first half of the 20th century, the percentage of foreign-born residents declined, even though many immigrants arrived fromeastern Europe. During World War II (1939-1945), both whites and blacks were attracted from the South to work in the city’s defense industries. In 1950 foreign-bornand black residents each made up about 16 percent of the total population. In the five decades after 1950, the city lost almost half of its population, as many white resident...

• Heredity - biology.

  allele from the mother and a mutated allele from the father. In both of these cases, the child will be a carrier. The child develops the disease only if he or she receives amutated allele from each parent. When both parents are carriers, there is a 25 percent chance that a child will be disease-free, a 25 percent chance that it will have thedisease, and a 50 percent chance that it will be a carrier. Examples of genetic diseases that follow the dominant-recessive pattern include sickle-cell anemi...

• 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...

• St. Louis (city) - geography. I INTRODUCTION Skyline of St. Louis, Missouri St. Louis,

  The metropolitan counties to the east of the Mississippi River in Illinois are home to both industry and fertile farmlands. The only heavily urbanized sections lie close to theriver in St. Clair County, site of East Saint Louis, and Madison County. The economy of East Saint Louis has been depressed since the 1960s, and the city is plagued bycrime, deteriorated housing, and declining property values. Several small cities have split off from East Saint Louis, taking large factories and much of the...

• Costa Rica - country.

  protection from future deforestation is not guaranteed. Deforestation places Costa Rica’s rich biodiversity in danger. The country’s location on the cusp between Northand South America and its abundance of tropical forests make it home to a great variety of species, many of them rare and threatened. Deforestation also contributesto the country’s problematic rate of soil erosion. Costa Rica is party to international treaties concerning biodiversity, climate change ( see Global Warming), endangere...

• 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...

• 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...

• 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...

• Interstellar Matter - astronomy.

  silhouette of a cloud of dust. At other times, it blocks only a percentage of the light from behind it, a process known by astronomers as extinction . The long, narrow dark lanes in the Milky Way as seen from Earth are examples of extinction. The amount of extinction is different for different wavelengths of light. A2 Reddening Starlight that does not get completely absorbed by interstellar dust can still be changed by the dust’s effects. As light passes through less dense patches of interstel...

• Telescope - astronomy.

  Observatory). In some telescopes designed in the 1990s, the mirror’s weight has been dramatically reduced by sandwiching a honeycomb pattern of glass ribs between a thin, butrigid, concave mirror and a flat back plate. Engineers have even developed meniscus mirrors—mirrors that are too thin to support their own weight. An adjustableframework supports the meniscus mirror, and servomechanical actuators, controlled by computer, continually adjust the shape of the mirror as it tracks celestial tar...

• London (England) - geography.

  In the northern part of the West End is Bloomsbury, the city’s traditional intellectual center, with its concentration of bookshops and homes of writers and academics. Inthe early 20th century a number of famous writers, critics, and artists who lived here became known as the Bloomsbury Group. Here, too, is the British Museum, one ofLondon’s chief tourist attractions. Nearby is the giant complex of the University of London, whose various colleges and departments have taken over much ofBloomsbury...

• 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...

• 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....

• Biodiversity.

  a common molecule, ribonucleic acid (RNA), and most also have deoxyribonucleic acid (DNA). These molecules direct the production of proteins—molecules responsiblefor the structure and function of virtually all living cells. This is the evolutionary chain of life. All species are descended from a single common ancestor. From that ancient single-celled microbe, all inherited RNA. As time goesby, species diverge and develop their own peculiar attributes, thus making their own contribution to biodiv...

• Biodiversity - biology.

  a common molecule, ribonucleic acid (RNA), and most also have deoxyribonucleic acid (DNA). These molecules direct the production of proteins—molecules responsiblefor the structure and function of virtually all living cells. This is the evolutionary chain of life. All species are descended from a single common ancestor. From that ancient single-celled microbe, all inherited RNA. As time goesby, species diverge and develop their own peculiar attributes, thus making their own contribution to biodiv...

• Los Angeles - geography.

  size and population) among all the cities in Los Angeles County. It is irregular in shape because it has grown over the years through the annexation of surrounding territoryand cities. The city proper is shaped like a lighted torch, its narrow handle extending north from the Port of Los Angeles to downtown Los Angeles, and its flames flickeringirregularly to the north, west, and northwest. Several separate cities—such as Beverly Hills, Santa Monica, and Culver City—are partly or completely surro...

• Brazil - country.

  occasional droughts. Brazil contains a wealth of mineral and plant resources that have not yet been fully explored. It possesses some of the world’s largest deposits of iron ore and containsrich deposits of many other minerals, including gold and copper. Brazil’s fossil fuel resources are modest, but this limitation is offset by the considerable hydroelectricpotential of the nation’s many rivers. Although Brazil is an important producer of tropical crops, areas of highly fertile land are limited...

• 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...

• Excerpt from Troilus and Cressida - anthology.

  Enter Pandarus and Cressida, veiled PANDARUS. Come, come, what need you blush? Shame's a baby. ( To Troilus ) Here she is now: swear the oaths now to her that you have sworn to me. ( To Cressida ) What, are you gone again? You must be watched ere you be made tame, must you? Come your ways, come your ways; an you draw backward, we'll put you i'th'fills. ( To Troilus ) Why do you not speak to her? ( To Cressida ) Come, draw this curtain, and let's see your picture. Alas the day, how loath you are...

• Deoxyribonucleic Acid - biology.

  bacterium Escherichia coli . In 1998 scientists achieved the milestone of sequencing the complete genome of a multicellular organism—a roundworm identified as Caenorhabditis elegans . The Human Genome Project, an international research collaboration, was established to determine the sequence of all of the 3 billion nucleotide base pairs that make up thehuman genetic material. In 2003 scientists completed the sequencing of the human genome. The project identified nearly all of the estimated 20...

• Psychoanalysis.

  A cornerstone of modern psychoanalytic theory and practice is the concept of anxiety, which institutes appropriate mechanisms of defense against certain dangersituations. These danger situations, as described by Freud, are the fear of abandonment by or the loss of the loved one (the object), the risk of losing the object's love,the danger of retaliation and punishment, and, finally, the hazard of reproach by the superego. Thus, symptom formation, character and impulse disorders, andperversions,...

• Bahrain - country.

  A Religion Almost all Bahrainis and the majority of nonnatives are followers of Islam (Muslims). About 70 percent of all native Bahrainis belong to the Shia branch of Islam, whilethe remainder, including the ruling al-Khalifa clan, are adherents of the Sunni branch. Non-Muslims, including Hindus, Buddhists, Christians, and Jews, account for 15percent of the total population. High unemployment among the Shia population has caused considerable discontent on the part of this group toward the Sunni...

• Dog. I INTRODUCTION Dog, mammal generally considered to be the first domesticated animal.

  French word for butterfly because it has ears that resemble butterfly wings, is a happy, friendly dog, suitable for small living spaces. The final dog group, nonsporting ,includes a wide variety of purebreds that differ in size, coat, overall appearance, and personality, from the shorthaired spotted dalmatian to the curly-haired poodle. V DOG BEHAVIOR Instinctive behaviors of the domestic dog are comparable to those of its wild relatives, the wolf, coyote, fox, and jackal. Unlike trained behavi...

• Dog - biology.

  French word for butterfly because it has ears that resemble butterfly wings, is a happy, friendly dog, suitable for small living spaces. The final dog group, nonsporting ,includes a wide variety of purebreds that differ in size, coat, overall appearance, and personality, from the shorthaired spotted dalmatian to the curly-haired poodle. V DOG BEHAVIOR Instinctive behaviors of the domestic dog are comparable to those of its wild relatives, the wolf, coyote, fox, and jackal. Unlike trained behavi...

• Encyclopedia of Philosophy: Action

  act. Where someone Φs by Ψ-ing, Ψ-ing is said to be more basic than Φ-ing; and the basic act is defined as the one than which no other was more basic. Moving the body (that is, moving a bit of it in one or another way) isusually a basic act. When Mary raises her right arm directly - in order to vote at the meeting - raising the right armis the basic act. But in the unusual case in which someone raises their right arm by lifting it with their left arm,raising the right arm, although a bodily...

• Inuit.

  VII HOUSING, TRANSPORTATION, AND CLOTHING Inuit homes are of two kinds: walrus or sealskin tents for summer and huts or houses for winter. Winter houses are usually made of stone, with a driftwood orwhalebone frame, chinked and covered with moss or sod. The entrance is a long, narrow passage just high enough to admit a person crawling on hands and knees.During long journeys some Canadian Inuit build igloos, winter houses of snow blocks piled in a dome shape (the term igloo comes from the I...

• Yangtze - Geography.

  A Agriculture and Industry Today about 400 million people, or about one-third of the population of China, live in the Yangtze Basin. Many are engaged in agriculture. The basin contributes nearlyhalf of China’s crop production, although only one-quarter of the basin is arable. The most fertile areas for farming are the Sichuan Basin, the plains between theYangtze and its tributary the Han, and the plains of the lower basin. In all about 40 percent of the cereals, more than 30 percent of the cott...

• Geology.

  terminology. Today the geologic time scale is generally agreed upon and used by scientists around the world, dividing time into eons, eras, periods, and epochs. Everyfew years, the numerical time scale is refined based on new evidence, and geologists publish an update. Geologists use several methods to determine geologic time. These methods include physical stratigraphy, or the placement of events in the order of their occurrence,and biostratigraphy, which uses fossils to determine geologic time...

• 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...

• Zebra - biology.

  C Life Span Captive zebras have lived into their late 30s. Life expectancy in the wild, where predators abound, is probably not much more than 12 years. IV SOCIAL BEHAVIOR Like horses, zebras have large brains and a wide variety of social behaviors. Although they cannot match the overall intelligence of mammals that hunt, zebras interactwith each other in complex ways. Zebras usually live in groups known as herds, but the social structure of these groups depends on the species. The plains zeb...

• Animal Behavior - biology.

  The first motor program analyzed in much detail was the egg-rolling response of geese. When a goose sees an egg outside its nest, it stares at the egg, stretches itsneck until its bill is just on the other side of the egg, and then gently rolls the egg back into the nest. At first glance this seems a thoughtful and intelligent piece ofbehavior, but it is a mechanical motor program; almost any smooth, rounded object (the sign stimulus) will release the response. Furthermore, removal of the egg on...