1113 résultats pour "only"

• Drug. I INTRODUCTION Drug, substance that affects the function of living cells, used

  normalizing chemical activity in the emotional centers of the brain. Antianxiety drugs, also referred to as tranquilizers, treat anxiety by decreasing the activity in theanxiety centers of the brain. Sedative-hypnotic drugs are used both as sedatives to reduce anxiety and as hypnotics to induce sleep. Sedative-hypnotic drugs act by reducing brain-cell activity.Stimulant drugs, on the other hand, increase neuronal (nerve cell) activity and reduce fatigue and appetite. Analgesic drugs reduce pain...

• 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...

• Molecule - chemistry.

  attracted to the negatively charged electrons between them. The electrons belong to the molecule as a whole. However, each hydrogen atom now has a complete outershell of two electrons. The formula H 2 describes a hydrogen molecule, a discrete unit. When a molecule contains just two atoms, such as the hydrogen molecule does, it is called a diatomic molecule. Some atoms can form covalent bonds with more than one other atom and thus create a larger molecule. Atoms form molecules with covalent bo...

• Connecticut Yankee - anthology.

  This missionary knight's name was La Cote Male Taile, and he said that this castle was the abode of Morgan le Fay, sister of King Arthur, and wife of King Uriens,monarch of a realm about as big as the District of Columbia—you could stand in the middle of it and throw bricks into the next kingdom. “Kings” and “Kingdoms”were as thick in Britain as they had been in little Palestine in Joshua's time, when people had to sleep with their knees pulled up because they couldn't stretch outwithout a passp...

• William Shakespeare I INTRODUCTION William Shakespeare English playwright and poet William Shakespeare, who lived in the late 1500s and early 1600s, is regarded as the greatest dramatist in the history of English literature.

  Avon, Warwickshire, a prosperous town in the English Midlands. Based on this record and on the fact that children in Shakespeare’s time were usually baptized two orthree days after birth, April 23 has traditionally been accepted as his date of birth. The third of eight children, William Shakespeare was the eldest son of John Shakespeare, a locally prominent glovemaker and wool merchant, and Mary Arden, thedaughter of a well-to-do landowner in the nearby village of Wilmcote. The young Shakespeare...

• Roman Empire .

  A Government Augustus did not derive his power from any single office, but from the authority of his name and his victory. In fact, he carefully pieced together a patchwork of powersthat allowed him to be an absolute ruler and yet avoid the hatred Caesar aroused as dictator. In Latin, the name Augustus implies both political authority and religiousrespect. The Romans had for some time called Octavian imperator , a title once awarded to victorious generals that soon became associated with the r...

• Roman Empire - History.

  A Government Augustus did not derive his power from any single office, but from the authority of his name and his victory. In fact, he carefully pieced together a patchwork of powersthat allowed him to be an absolute ruler and yet avoid the hatred Caesar aroused as dictator. In Latin, the name Augustus implies both political authority and religiousrespect. The Romans had for some time called Octavian imperator , a title once awarded to victorious generals that soon became associated with the r...

• Jesus Christ I INTRODUCTION Jesus Christ (between 8 and 4 BC-AD 29?

  Monday and Tuesday, according to the synoptists), he drove from the Temple the traders and moneychangers who, by long-established custom, had been allowed totransact business in the outer court (Mark 11:15-19), and he disputed with the chief priests, the scribes, the Pharisees, and the Sadducees questions about hisauthority, tribute to Caesar, and the resurrection. On Tuesday, Jesus also revealed to his disciples the signs that would usher in his Parousia, or second coming. See Second Coming. O...

• Jesus Christ.

  Monday and Tuesday, according to the synoptists), he drove from the Temple the traders and moneychangers who, by long-established custom, had been allowed totransact business in the outer court (Mark 11:15-19), and he disputed with the chief priests, the scribes, the Pharisees, and the Sadducees questions about hisauthority, tribute to Caesar, and the resurrection. On Tuesday, Jesus also revealed to his disciples the signs that would usher in his Parousia, or second coming. See Second Coming. O...

• Ancient Rome .

  attributed to Numa, including the selection of virgins to be priestesses of the goddess Vesta. He also established a calendar to differentiate between normal workingdays and those festival days sacred to the gods on which no state business was allowed. His peaceful reign lasted from 715 to 673 BC. Under Tullus Hostilius (672–641 BC) the Romans waged an aggressive foreign policy and began to expand their lands by the conquest of nearby cities like Alba Longa. When the warlike King Hostilius co...

• Ancient Rome - USA History.

  attributed to Numa, including the selection of virgins to be priestesses of the goddess Vesta. He also established a calendar to differentiate between normal workingdays and those festival days sacred to the gods on which no state business was allowed. His peaceful reign lasted from 715 to 673 BC. Under Tullus Hostilius (672–641 BC) the Romans waged an aggressive foreign policy and began to expand their lands by the conquest of nearby cities like Alba Longa. When the warlike King Hostilius co...

• 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...

• 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...

• Lewis and Clark Expedition.

  took a small detachment into present-day north central Montana, thinking that the course of the Marias River might provide an American claim to fur-rich country inwhat is now the Canadian province of Alberta. In August the groups reunited on the Missouri River, near the mouth of the Yellowstone. They arrived in St. Louis onSeptember 23, 1806. C Relations with the Native Americans and Spanish The Lewis and Clark Expedition made a journey through the homelands of native people. What American expl...

• Lewis and Clark Expedition - explorer.

  took a small detachment into present-day north central Montana, thinking that the course of the Marias River might provide an American claim to fur-rich country inwhat is now the Canadian province of Alberta. In August the groups reunited on the Missouri River, near the mouth of the Yellowstone. They arrived in St. Louis onSeptember 23, 1806. C Relations with the Native Americans and Spanish The Lewis and Clark Expedition made a journey through the homelands of native people. What American expl...

• Jane Austen I INTRODUCTION Jane Austen English author Jane Austen crafted satirical romances set within the confines of upper-middle-class English society.

  up their personal pride and prejudices before they can enter into a happy relationship together. As do Austen’s earlier writings, Pride and Prejudice displays the themes of appearance versus reality, and impulse versus deliberation. Elizabeth, trusting her own impulses, makes a mistake about Darcy and his apparent arrogance that deliberation and further experience eventually cause her to correct. Of Elizabeth, Austenwrote: “I must confess that I think her as delightful a creature as ever appea...

• Gravitation I INTRODUCTION Gravitation, the force of attraction between all objects that tends to pull them toward one another.

  precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...

• Gravitation - astronomy.

  precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...

• International Criminal Court.

  only exercise its jurisdiction when a national court is unwilling or unable to carry out the investigation or prosecution. For example, the ICC might intervene when agovernment’s judicial system has collapsed or is actively shielding a person from criminal responsibility. The court may hold accountable any person aged 18 or older at the time of the crime without regard to the individual’s official duties or functions. Therefore, heads ofstate, legislators, and other high-ranking government offic...

• Turkmenistan - country.

  A Ethnic Groups With Turkmens constituting 77 percent of the population, Turkmenistan is the most ethnically homogeneous of the Central Asian republics. Uzbeks make up the largestminority group, with about 9 percent of the population. Other ethnic groups include Russians, Kazakhs, Tatars, Ukrainians, Azeris (ethnic Azerbaijanis), Armenians, andBaluch. In 1993 a bilateral treaty between Turkmenistan and Russia granted dual citizenship to Russians in the republic. At the 1995 census Russians cons...

• American Revolution.

  C1 The South Southern agriculture was founded on the cultivation of tobacco, wheat, and corn in Virginia, Maryland, and North Carolina, and of rice and indigo (a blue dye) in SouthCarolina and Georgia. There was a large demand for these crops in Europe. These crops were cultivated with the help of black slaves imported from Africa. The whiteplanter class in the South was the most powerful, both politically and economically. C2 The North Wheat was the main cash crop of the mid-Atlantic colonies...

• American Revolution - U.

  C1 The South Southern agriculture was founded on the cultivation of tobacco, wheat, and corn in Virginia, Maryland, and North Carolina, and of rice and indigo (a blue dye) in SouthCarolina and Georgia. There was a large demand for these crops in Europe. These crops were cultivated with the help of black slaves imported from Africa. The whiteplanter class in the South was the most powerful, both politically and economically. C2 The North Wheat was the main cash crop of the mid-Atlantic colonies...

• New Hampshire - geography.

  Washington. D1 Temperature The coldest parts of the state are in the White Mountains and the extreme north. Average January temperatures range from about -11° C (about 12° F) along theCanadian border to about -3° C (about 26° F) along the coast. July temperatures range from about 17° C (about 63° F) in the mountains to about 21° C (about 70° F)in the south. D2 Precipitation Precipitation is evenly distributed throughout the year over most of the state. However, the higher peaks of the White Mo...

• New Hampshire - USA History.

  Washington. D1 Temperature The coldest parts of the state are in the White Mountains and the extreme north. Average January temperatures range from about -11° C (about 12° F) along theCanadian border to about -3° C (about 26° F) along the coast. July temperatures range from about 17° C (about 63° F) in the mountains to about 21° C (about 70° F)in the south. D2 Precipitation Precipitation is evenly distributed throughout the year over most of the state. However, the higher peaks of the White Mo...

• 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...

• 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...

• Iowa - geography.

  Okoboji, Lost Island, Silver, and West Swan lakes. In addition, reservoirs have been created by damming several smaller Iowa rivers. There are a number of largereservoirs behind dams on the Mississippi River along the Iowa state line. C Climate Iowa’s climate is characterized by warm, generally moist summers and cold winters. Temperatures vary considerably from season to season and, at times, from day today. However, monthly averages are relatively uniform throughout the state and usually vary...

• Iowa - USA History.

  Okoboji, Lost Island, Silver, and West Swan lakes. In addition, reservoirs have been created by damming several smaller Iowa rivers. There are a number of largereservoirs behind dams on the Mississippi River along the Iowa state line. C Climate Iowa’s climate is characterized by warm, generally moist summers and cold winters. Temperatures vary considerably from season to season and, at times, from day today. However, monthly averages are relatively uniform throughout the state and usually vary...

• 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...

• 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...

• United Kingdom - country.

  B Natural Regions and Topography The island of Great Britain can be divided into two major natural regions—the highland zone and the lowland zone. The highland zone is an area of high hills andmountains in the north and west. The lowland zone in the south and east consists mostly of rolling plains. The zones are divided by an imaginary line running throughEngland from the River Exe on the southwest coast to the mouth of the River Tees on the northeast coast. The lowland zone has a milder climat...

• Grover Cleveland.

  Americans, Roman Catholics, and Southerners, who all generally supported the Democratic Party. The statement lost Blaine any chance of getting the Irish Americanvote in New York City. The Mugwumps supported Cleveland because of Blaine’s political past. Even the Prohibition Party candidate received 25,000 votes that normallywould have gone to the Republican candidate. New York’s 36 electoral votes swung the election to Cleveland. He won the state’s vote by only about 1000 in a total vote of more...

• Grover Cleveland

  Americans, Roman Catholics, and Southerners, who all generally supported the Democratic Party. The statement lost Blaine any chance of getting the Irish Americanvote in New York City. The Mugwumps supported Cleveland because of Blaine’s political past. Even the Prohibition Party candidate received 25,000 votes that normallywould have gone to the Republican candidate. New York’s 36 electoral votes swung the election to Cleveland. He won the state’s vote by only about 1000 in a total vote of more...

• 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...

• Neandertals.

  Neandertals made stone tools by striking flakes from rock “cores.” The cores were carefully selected and prepared so that only a single blow was normally required todetach a flake. A number of relatively standardized flakes were sometimes produced from a single core. These sharp flakes served as “blanks” that were further workedand shaped into the desired tools. Suitable stone was sometimes rare, and often tools were sharpened and resharpened to make new tools, yielding a whole variety ofshapes...

• Communism.

  In Britain, Robert Owen, a philanthropic Welsh manufacturer, strove against the social problems brought about by the Industrial Revolution and sought to improve thewelfare of workers. As manager of a cotton mill, he enhanced the environment of his workers by improving their housing, modernizing mill equipment for greater safetyand sanitation, and establishing low-priced stores for the workers and schools for their children. Owen believed that workers, rather than governments, should createthe in...

• Communism .

  In Britain, Robert Owen, a philanthropic Welsh manufacturer, strove against the social problems brought about by the Industrial Revolution and sought to improve thewelfare of workers. As manager of a cotton mill, he enhanced the environment of his workers by improving their housing, modernizing mill equipment for greater safetyand sanitation, and establishing low-priced stores for the workers and schools for their children. Owen believed that workers, rather than governments, should createthe in...

• Chemistry - chemistry.

  parts of oxygen by weight, which is a ratio of about 1 to 8, regardless of whether the water came from the Mississippi River or the ice of Antarctica. In other words, acompound has a definite, invariable composition, always containing the same elements in the same proportions by weight; this is the law of definite proportions. Many elements combine in more than one ratio, giving different compounds. In addition to forming water, hydrogen and oxygen also form hydrogen peroxide.Hydrogen peroxide h...

• Maine - geography.

  temperatures range from 17° to 21°C (62° to 70°F) with the southern interior being the warmest and the east coast and north the coolest. However, daytime summertemperatures may reach the lower 30°s C (lower 90°s F), and temperatures in winter have fallen as low as -44°C (-48°F) in the interior. D2 Precipitation Precipitation (rainfall and snowfall) in Maine is evenly distributed throughout the year. Most areas receive from 860 to 1,020 mm (34 to 40 in) yearly, although parts ofthe coast are som...

• Maine - USA History.

  temperatures range from 17° to 21°C (62° to 70°F) with the southern interior being the warmest and the east coast and north the coolest. However, daytime summertemperatures may reach the lower 30°s C (lower 90°s F), and temperatures in winter have fallen as low as -44°C (-48°F) in the interior. D2 Precipitation Precipitation (rainfall and snowfall) in Maine is evenly distributed throughout the year. Most areas receive from 860 to 1,020 mm (34 to 40 in) yearly, although parts ofthe coast are som...

• 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)...

• 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...

• 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...

• Brian Mulroney.

  At the party convention Mulroney was one of the candidates who ran against Clark. This time Mulroney did not have to contend with a rival candidate from Québec. Healso had the support of the remnants of the Diefenbaker faction—who disliked Clark even more than they disliked Mulroney. Mulroney was also endorsed by asubstantial group of members of Parliament; this endorsement helped allay concerns about whether he could provide effective leadership in Parliament. Mulroney waselected leader of the...

• Brian Mulroney - Canadian History.

  At the party convention Mulroney was one of the candidates who ran against Clark. This time Mulroney did not have to contend with a rival candidate from Québec. Healso had the support of the remnants of the Diefenbaker faction—who disliked Clark even more than they disliked Mulroney. Mulroney was also endorsed by asubstantial group of members of Parliament; this endorsement helped allay concerns about whether he could provide effective leadership in Parliament. Mulroney waselected leader of the...

• North Carolina - geography.

  The drainage divide in North Carolina follows the Blue Ridge range on the eastern margin of the mountain region. This is called the “Eastern Continental Divide.” West ofthis divide, rivers drain into the Mississippi River through the Tennessee River and other tributaries of the Ohio River. The French Broad, the largest, and the LittleTennessee flow into the Tennessee River. The New River flows into the Kanawha River of West Virginia which in turn flows into the Ohio River. Most of the state’s ri...

• Extrasolar Planets - astronomy.

  When a planet passes in a front of the star it orbits—an event called a transit—it causes a small dip in the brightness of the star. Measuring the slight change in thebrightness can be used not only to directly detect a planet, but to determine its size and orbit. However, the planet needs to orbit in a plane that lies in a telescope’sline of sight on the star. Despite long odds, Earth-based telescopes have detected and studied a few exoplanets using this method. The first space telescope design...

• North Carolina - USA History.

  The drainage divide in North Carolina follows the Blue Ridge range on the eastern margin of the mountain region. This is called the “Eastern Continental Divide.” West ofthis divide, rivers drain into the Mississippi River through the Tennessee River and other tributaries of the Ohio River. The French Broad, the largest, and the LittleTennessee flow into the Tennessee River. The New River flows into the Kanawha River of West Virginia which in turn flows into the Ohio River. Most of the state’s ri...