813 résultats pour "may"

• Bible.

  collection of many different books. The Old Testament is by no means a unified book in terms of authorship, date of composition, or literary type; it is instead a veritablelibrary. Generally speaking, the books of the Old Testament and their component parts may be identified as narratives, poetic works, prophetic works, law, or apocalypses.Most of these are broad categories that include various distinct types or genres of literature and oral tradition. None of these categories is limited to the...

• Dinosaur - biology.

  The behavior of dinosaurs was governed by their metabolism and by their central nervous system. The dinosaurs’ metabolism—the internal activities that supply thebody’s energy needs—affected their activity level. It is unclear whether dinosaurs were purely endothermic (warm-blooded), like modern mammals, or ectothermic (cold-blooded), like modern reptiles. Endotherms regulate their body temperature internally by means of their metabolism, rather than by using the temperature oftheir surroundin...

• "A Modest Proposal" - anthology.

  I SHALL now therefore humbly propose my own Thoughts; which I hope will not be liable to the least Objection. I HAVE been assured by a very knowing American of my Acquaintance in London; that a young healthy Child, well nursed, is, at a Year old, a most delicious, nourishing, and wholesome Food; whether Stewed, Roasted, Baked, or Boiled; and, I make no doubt, that it will equally serve in a Fricasie, or Ragoust. I DO therefore humbly offer it to publick Consideration, that of...

• Fruit - biology.

  from a flower with several pistils. The ovary may have a single compartment, or carpel, which houses the ovule or ovules. Or the ovary may consist of two or morecarpels, each of which may contain one or more ovules. A drupe develops from an ovary with a single carpel and is characterized by an edible exocarp and mesocarp and an inedible, hard endocarp, or pit that encloses asingle seed. Cherries, peaches, apricots, and plums are examples of drupes. Almonds also are classified as drupes, but in a...

• Memory (psychology).

  memory span —how many items people can correctly recall in order. Researchers would show people increasingly long sequences of digits or letters and then ask them to recall as many of the items as they could. In 1956 American psychologist George Miller reviewed many experiments on memory span and concluded that peoplecould hold an average of seven items in short-term memory. He referred to this limit as “the magical number seven, plus or minus two” because the results of thestudies were so consi...

• Stock Exchange.

  A Example of a Trade In an example of a trade, an investor wanting to buy 200 shares—also known as two round lots, of 100 shares each—of IBM stock will telephone or e-mail the order to abrokerage firm. This communication is normally made to an individual called a stockbroker. The investor might desire to buy the shares at the market, or current, price.On the other hand, the investor may choose to pay no more than a set amount per share. The brokerage firm then contacts one of its floor brokers...

• Leaf - biology.

  The mesophyll, sandwiched between the upper and lower epidermis, consists of many thin-walled cells that are usually arranged in two layers. The palisade layer is next to the upper epidermis. It consists of cylindrical cells that are packed closely together. Next to the palisade layer and making up most of the thickness of the leaf bladeis the spongy layer. The spongy layer consists of roundish cells that are packed loosely together and have numerous air spaces between them. In most plants t...

• Telephone.

  digits is dialed. The development of inexpensive and reliable amplification provided by the introduction of the transistor in the 1960s made practical the design of adialing system based on the transmission of relatively low power tones instead of the higher-power dial pulses. Today most telephones have push buttons instead of a rotary dial. Touch-Tone is an optional service, and telephone companies still maintain the ability to receive pulsedialing. Push-button telephones usually have a switch...

• Civil Rights and Civil Liberties.

  A Religious Freedom Although religious freedom has not generally been curtailed in the United States, Roman Catholics, Jews, and members of such unconventional Protestant groups as theOneida Community and the Church of Jesus Christ of Latter-day Saints have historically been discriminated against and sometimes have even been persecuted,although today overt discrimination has almost vanished. The federal Civil Rights Act of 1964, as well as many state and local laws, prohibits religious discrimi...

• Medicine.

  C Other Health Professionals Medicine is not restricted to physicians. A wide variety of health care practitioners work in this exciting field. By far the largest professional group is nurses. Registerednurses help physicians during examinations, treatment, and surgery. They observe, evaluate, and record patients’ symptoms, administer medications, and provideother care ( see Nursing). Nurse practitioners perform basic duties once reserved for physicians, such as diagnosing and treating common i...

• Compositionality

  sentence construction, an operation on meanings, such that the meaning of any sentence is mechanically determined by applying the operations on meanings (given by the rules used in constructing the sentence) to the meanings of the simple parts. (Often a host of extra restrictions are incorporated. For example: the operations may be limited to applying function to argument; the order in which operations are applied may be settled by the structure of the sentence.) Some see such principles as prov...

• Football.

  C Special Teams Each team has players who enter the game during special plays such as kickoffs, field goals, punts, and returns. The kicker kicks off at the beginning of a game or half,and after his team has scored. The kicker also scores points for the offensive team by kicking the ball through the goalpost’s vertical posts, also known as the uprights;these scores are called field goals. When the offensive team must surrender the ball to the opponents, a punter comes in to kick the ball downfi...

• Iraq - country.

  The Euphrates begins in Turkey, crosses Syria, and enters Iraq at Abū Kam āl. The flow of the Euphrates into Iraq has been greatly reduced by dams built by Turkeyand Syria. The gradient of the Euphrates above the town of H īt, in west central Iraq, is steep. In the 2,640 km (1,640 mi) from its source in Turkey to H īt, the river fallsfrom 3,000 m (10,000 ft) to a low water elevation of 50 m (170 ft) above sea level, an average drop of 1 m per km (6 ft per mi). In Iraq below H īt the fall is very...

• Acid Rain.

  the Adirondack Mountains of New York State, a quarter of the lakes and ponds are acidic, and many have lost their brook trout and other fish. In the middleAppalachian Mountains, over 1,300 streams are afflicted. All of Norway’s major rivers have been damaged by acid rain, severely reducing salmon and trout populations. E Plants and Animals The effects of acid rain on wildlife can be far-reaching. If a population of one plant or animal is adversely affected by acid rain, animals that feed on tha...

• Bat - biology.

  tomb bat has rather small ears. The shapes of bat ears are extremely varied. The wide ears of the Australian false vampire bat meet above the head and are fused.Many bats are able to turn their ears in the direction of faint noises. Bat hearing and its use in echolocation are highly developed. Some bats have large, conspicuous eyes, while others may have small beady eyes. This variation suggests that vision plays different roles in the lives of various species.Despite the familiar expression, 'b...

• Venus (planet) - astronomy.

  level winds circle the planet at 360 km/h (225 mph), making a complete rotation in only four days. These winds are said to super-rotate because they travel muchfaster than the rotation of the planet itself. These high-speed winds cover the planet completely, blowing toward the west at virtually every latitude from equator topole. The motions of descending probes, however, have shown that the bulk of Venus’s tremendously dense atmosphere, closer to the planet’s surface, is almoststagnant. From th...

• Ulysses S.

  In the autumn of 1862, Grant began planning the drive on Vicksburg, Mississippi, the Confederate stronghold on the Mississippi River, which was to yield one of hisgreatest military successes. After several unsuccessful attempts on Vicksburg during the winter, Grant devised a new strategy of attack. In April 1863 he marched hisarmy south along the west side of the river to a point well below the heavily defended city. There, with the aid of the Union river fleet, he crossed the river and began as...

• Ulysses S.

  In the autumn of 1862, Grant began planning the drive on Vicksburg, Mississippi, the Confederate stronghold on the Mississippi River, which was to yield one of hisgreatest military successes. After several unsuccessful attempts on Vicksburg during the winter, Grant devised a new strategy of attack. In April 1863 he marched hisarmy south along the west side of the river to a point well below the heavily defended city. There, with the aid of the Union river fleet, he crossed the river and began as...

• Automation.

  Not all industries require the same degree of automation. Agriculture, sales, and some service industries are difficult to automate. The agriculture industry may becomemore mechanized, especially in the processing and packaging of foods; however, in many service industries such as supermarkets, for example, a checkout countermay be automated and the shelves or supply bins must still be stocked by hand. Similarly, doctors may consult a computer to assist in diagnosis, but they must makethe final...

• Election.

  majority systems usually reduce the number of competitive political parties—for example, the mostly two-party system in the United States. Proportional representation systems boost participation by increasing the value of a vote to smaller or more marginal portions of a national population. In the UnitedStates, plurality or majority systems have reduced the incentive to vote of citizens who do not identify closely with the Democratic or Republican Party. Disillusionmentwith the major parties and...

• Artificial Intelligence.

  Work in AI has primarily focused on two broad areas: developing logic-based systems that perform common-sense and expert reasoning, and using cognitive andbiological models to simulate and explain the information-processing capabilities of the human brain. In general, work in AI can be categorized within three research anddevelopment types: symbolic, connectionist, and evolutionary. Each has characteristic strengths and weaknesses. A Symbolic AI Symbolic AI is based in logic. It uses sequences...

• Map - geography.

  Relief MapRelief maps are three-dimensional models of the terrain in an area; on them, color and scale are used to indicate geographicalfeatures rather than simply to delineate political boundaries. Because of this feature, relief maps are extensively used in engineeringand the military. This map shows portions of Alaska and northwestern Canada.United States Geological Survey Among the most important of the special-purpose maps are hydrographic and aviation charts. Hydrographic charts are used f...

• River.

  IV RIVER PATTERNS River patterns, or general shapes, depend on the geologic zone and the climate of the location. There are four river patterns: meandering, braided, anastomosing, andstraight. A meandering pattern follows a winding, turning course. A braided pattern has connected channels that resemble a hair braid. An anastomosing river patterncombines features of the meandering and braided patterns. Some river patterns are simply straight channels. Meandering and braided are the most common...

• River - Geography.

  IV RIVER PATTERNS River patterns, or general shapes, depend on the geologic zone and the climate of the location. There are four river patterns: meandering, braided, anastomosing, andstraight. A meandering pattern follows a winding, turning course. A braided pattern has connected channels that resemble a hair braid. An anastomosing river patterncombines features of the meandering and braided patterns. Some river patterns are simply straight channels. Meandering and braided are the most common...

• Ice Ages.

  B Future Ice Ages The record of previous glacial activity is the best indicator for future ice ages. Scientists examine the evidence for the numerous 100,000-year glacial-interglacial cycleswithin the present ice age to attempt a forecast of future ice ages. Since all previous ice ages lasted tens of millions of years, our present ice age will likely continue fora considerable amount of time. Each glaciation begins slowly and may take 80,000 years or more to reach its maximum extent. A rapid me...

• Bear - biology.

  programs sponsored by zoos or other breeding centers have attempted to breed giant pandas in captivity, although most of these programs have proved unsuccessful.Among the difficulties faced by captive breeders has been the problem of encouraging a female giant panda to mate with a selected male during the two to three daysof the year when she is most fertile, a period known as estrus. B Spectacled Bear Creamy-white rings surrounding the eyes give the spectacled bear its name. Its shaggy coat of...

• Folktales I INTRODUCTION "Little Red Riding Hood" The popular children's story "Little Red Riding

  seemed important to them. Thus, the Grimms postulated a common Indo-European origin for folktales, and the German philologist Theodor Benfey as well as theScottish writer William Clouston believed that stories diffused by way of travelers migrating east and west from India. Such theories, however, have proven incompleteand inadequate. Nevertheless, the research of these and other scholars greatly stimulated interest in folklore and folktales. The German scholar Max Muller held thatmyths originat...

• Criminal Law.

  for rehabilitative treatment for the offender. On the other hand, the goals of punishment may at times conflict. The retributive and deterrence theories call for theinfliction of unpleasant experiences upon the criminal, including harsh prison treatment; but the prison environment may not be conducive to, or may even defeat,rehabilitation. No one theory of punishment addresses all the goals of criminal law. A combination of theories and goals plays a part in the thinking of the legislators who e...

• Sexual Harassment.

  A person who believes he or she has experienced sexual harassment on the job has a limited period of time in which to file a complaint with the EEOC. After the EEOCinvestigates the matter, it issues a right to sue letter, regardless of its conclusions about the matter. The victim then has 90 days to file a lawsuit against the employer in federal court. If he or she is successful in the lawsuit, the victim can receive up to $300,000 in compensatory damages for each incident of unlawful harassme...

• Development (biology) - biology.

  Understanding the molecular machinery within cells gives biologists a direct basis for understanding growth, because growth is the synthesis of new protoplasm, andbiologists know the basic mechanism of this synthesis. One key gap, however, exists in this knowledge. Biologists want to know not only how substances aresynthesized but also how growth is controlled so that the proportions of an animal or plant remain consistent from generation to generation. The direction and amountof growth, which a...

• Prison.

  Furthermore, experts disagree about whether imprisoning criminals actually prevents further crime. Some critics charge that American prisons simply warehouseviolence—meaning that U.S. prison inmates are confined and incapacitated in large numbers, with little or no effort made to rehabilitate them. Critics have labeled theresult of this process turnstile justice, referring to the fact that most inmates are chronic and persistent offenders and return to prison following conviction for new crime...

• Fire - chemistry.

  were usually natural caves. Eventually people learned to dip branches in pitch to form torches. They created crude lamps by filling a hollowed out piece of stone withmoss soaked in oil or tallow (a substance derived from animal fat). By cooking with fire, prehistoric people made the meat of the animals they killed more palatable and digestible. They learned to preserve meat by smoking it over a fire,vastly decreasing the danger of periodic starvation. Cooking also enabled them to add some for...

• Fungus - biology.

  Many fungi can reproduce by the fragmentation of their hyphae. Each fragment develops into a new individual. Yeast, a small, single-celled fungus, reproduces bybudding, in which a bump forms on the yeast cell, eventually partitioning from the cell and growing into a new yeast cell. V CLASSIFICATION OF FUNGI Scientists have long disagreed about how to classify fungi, and the classification systems are still developing. The first description of fungi was published in 1729 byItalian botanist Pier...

• Endocrine System.

  thermostat. When the heat in a house falls, the thermostat responds by switching the furnace on, and when the temperature is too warm, the thermostat switches thefurnace off. Usually, the change that a hormone produces also serves to regulate that hormone's secretion. For example, parathyroid hormone causes the body toincrease the level of calcium in the blood. As calcium levels rise, the secretion of parathyroid hormone then decreases. This feedback mechanism allows for tight controlover hormon...

• Forensic Science.

  barbiturates, cocaine, amphetamines, and heroin. When a body is discovered in a lake, stream, river, or ocean and the lungs are found to be filled with water, the medical examiner must determine if the drowningoccurred where the body was found or elsewhere. A standard microscope that can magnify objects to 1500 times their actual size is used to look for the presence orabsence of diatoms, single-celled algae that are found in all natural bodies of water. The absence of diatoms raises the possi...

• 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...

• Honey Bee - biology.

  B Reproduction and Development The queen controls the sex of her offspring. When an egg passes from her ovary to her oviduct, the queen determines whether the egg is fertilized with sperm from thespermatheca. A fertilized egg develops into a female honey bee, either worker or queen, and an unfertilized egg becomes a male honey bee, or drone. The queen lays the eggs that will develop into more queens in specially constructed downward-pointing, peanut-shaped cells, in which the egg adheres to the...

• 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...

• Neptune (planet) - astronomy.

  The gaseous atmosphere of Neptune contains hydrogen, helium, and about 3 percent methane. It extends about 5,000 km (about 3,000 mi) above the planet’s ocean.Light reflected from Neptune’s deep atmosphere is blue, because the atmospheric methane absorbs red and orange light but scatters blue light. In 1998 astronomersalso identified molecules of methyl in Neptune’s atmosphere. Methyl molecules each contain one carbon atom and three hydrogen atoms. Methyl molecules are knownas hydrocarbon radical...

• Ancient Egypt.

  around 4500 BC. The style and decoration of the pottery found at these sites differ from those of pottery found in Upper Egypt. The northern type eventually fell out of use. Other differences between the peoples in Upper Egypt and Lower Egypt include the nature of their architecture and the arrangements for burial of the dead, thelatter perhaps signifying differing religious beliefs. B Unification and Early Dynastic Period By 3500 BC, the settlement of Hierakonpolis, located on the west bank...

• Ancient Egypt - USA History.

  around 4500 BC. The style and decoration of the pottery found at these sites differ from those of pottery found in Upper Egypt. The northern type eventually fell out of use. Other differences between the peoples in Upper Egypt and Lower Egypt include the nature of their architecture and the arrangements for burial of the dead, thelatter perhaps signifying differing religious beliefs. B Unification and Early Dynastic Period By 3500 BC, the settlement of Hierakonpolis, located on the west bank...

• 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...

• Library (institution).

  rooms, special galleries for exhibitions, auditoriums for lectures or concerts, computer rooms, children’s rooms, photocopy rooms, and classrooms. A3 Lending Materials As part of their mission to provide information resources to the community, public libraries allow users to borrow items from their collections for limited amounts of time.To be eligible to borrow public library materials, a user must register her or his name, address, and other basic information with the local library’s circulat...

• Coral - biology.

  Soft corals lack a distinct skeleton. Although they live in colonies, the individual polyps are fused into a complex body, usually strengthened by small lumps or spikesknown as sclerites, which are made of protein and calcite. Soft corals come in a variety of shapes, including undulating sheets, upright mushroomlike shapes, andbeautiful shapes that form branches. A number of other octocorals have skeletons made from a hard or horny protein, sometimes strengthened with more brittle calcareous dep...

• Jupiter (planet) - astronomy.

  Beneath the supercritical fluid zone, the pressure reaches 3 million Earth atmospheres. At this depth, the atoms collide so frequently and violently that the hydrogenatoms are ionized—that is, the negatively charged electrons are stripped away from the positively charged protons of the hydrogen nuclei. This ionization results in asea of electrically charged particles that resembles a liquid metal and gives rise to Jupiter’s magnetic field. This liquid metallic hydrogen zone is 30,000 to 40,000 k...

• 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...

• Rhinoceros - biology.

  Male and female rhinos have a similar physical appearance, although male rhinos are usually larger than females, with the size difference varying between species. Inthe wild, some rhinos probably live into their late 40s, and they have survived into their 30s in captivity. IV TYPES OF RHINOCEROSES Until recently, mammalogists divided the rhinoceros family into three subfamilies, each with different characteristics. Scientists now believe that living rhinos belong to asingle subfamily, although...

• Physics I INTRODUCTION Physics, major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces.

  Starting about 1665, at the age of 23, Newton enunciated the principles of mechanics, formulated the law of universal gravitation, separated white light into colors,proposed a theory for the propagation of light, and invented differential and integral calculus. Newton's contributions covered an enormous range of naturalphenomena: He was thus able to show that not only Kepler's laws of planetary motion but also Galileo's discoveries of falling bodies follow a combination of his ownsecond law of m...

• Amphibian (animal) - biology.

  strong enough to kill potential predators. C Hearing, Vision, and Vocalizations Amphibians rely on their senses to find food and evade predators. Amphibians lack external ears but have well-developed internal ears. Hearing is most acute in frogs,which typically have a middle ear cavity for transferring sound vibrations from the eardrum, or tympanum, to the inner ear. Frogs and toads also use their keen hearingin communicating with one another. Using a true voice box, or larynx, and a large, exp...