38 résultats pour "secondary"

• Public Education in the United States.

  opportunities for them to break out from whatever social or economic circumstances constrained their development. IV HIGHER EDUCATION During the 20th century participation in higher or postsecondary education in the United States increased as dramatically as it did in American high schools. At thebeginning of the century about 2 percent of Americans from the ages of 18 to 24 were enrolled in a college. There were fewer than 1,000 colleges then, with enrollmenttotaling about 157,000 students. N...

• Plant - biology.

  B1 Vacuoles Vacuoles are membrane-bound cavities filled with cell sap, which is made up mostly of water containing various dissolved sugars, salts, and other chemicals. B2 Plastids Plastids are types of organelles, structures that carry out specialized functions in the cell. Three kinds of plastids are important here. Chloroplasts contain chlorophyllsand carotenoid pigments; they are the site of photosynthesis, the process in which light energy from the sun is fixed as chemical energy in the b...

• Finland - country.

  Productive forestland is the most valuable natural resource of Finland. Spruce, pine, and silver birch are the principal trees used to manufacture wood and pulp andpaper products. Finland lacks coal and petroleum resources and is a net importer of energy resources. However, Finland does have significant deposits of peat, which is cut from thenumerous peat bogs that cover much of the north. Peat is an important heat source for homes, and it provides about 7 percent of Finland’s electricity needs....

• Nova - astronomy.

  When first discovered, the spectrum of a nova shows that the expanding layers of gas that cause the brightening have temperatures of 40,000° to 50,000° C (70,000°to 90,000° F)—about eight times as hot as the surface of the Sun. By the time a nova reaches maximum brightness, the temperature of the material has fallen to about10,000° C (about 20,000° F), or lower. Just after maximum brightness, the escaping cloud of gas cools and expands enough to become transparent. This transparency allows astro...

• Austria - country.

  Wildlife is generally scarce in Austria. Chamois, deer, and marmot are still present; bear, which were once abundant, are now almost completely absent. Hunting isstrictly regulated to protect the remaining species. F Environmental Issues Industrial emissions, a high volume of tourist traffic, and significant air pollution from other countries—principally the former East Germany, Slovakia, and the CzechRepublic—combine to make acid rain the major environmental problem in Austria. One-quarter of...

• SECONDARY ROADS AND THE ART OF MOTORCYCLING

  It was some years ago that IJIY wife and 1 and our friends first began to catch on to these roads. We. took them once in a while for variety or for a shortcut to another main highway, and each time the scenery was grand and we left the road with a feeling of relaxation and enjoyment. We did this time after time before realizing what should have been obvious: these roads are truly different from the main ones. The whole pace (1) of lif...

• Human Sexuality.

  About six weeks after conception, if a Y chromosome is present in the embryo's cells (as it is in normal males), a gene on the chromosome directs the undifferentiatedgonads to become testes. If the Y chromosome is not present (as in normal females), the undifferentiated gonads will become ovaries. If the gonads become testes, they begin to produce androgens (male hormones, primarily testosterone) by about eight weeks after conception. These androgens stimulate development of the one set of the...

• Martial Arts.

  These movements are based on stylized renditions of ancient kung fu arm and foot blows. C Tae Kwon Do Tae kwon do (Korean for 'way of hands and feet') was founded in 1955 by a group of masters led by Korean general Choi Hong Hi. It is the national sport and pastimeof Korea and is also popular throughout the world. Often referred to as Korean karate, tae kwon do is reputedly based on ancient Korean and modern Japanesemethods of combat. Basic to tae kwon do are many spectacular kicks, particularl...

• Parkinson Disease.

  III SYMPTOMS Parkinson disease most notably affects motor control (muscle activity). The disease progresses differently for each individual—symptoms develop swiftly in some peopleand slowly in others. Some Parkinson patients may develop problems that affect their intellect or ability to reason, or they may suffer from depression or anxiety. A Motor Control Problems Doctors look for the presence of four principal symptoms in patients they suspect may have Parkinson disease. Tremor (the involun...

• Czech Republic - country.

  enforcement of environmental regulations. Environmental considerations have also led some government officials to promote nuclear energy as a key source of powerfor the country’s future. The Czech Republic produces most of its energy by burning domestic coal. Much of the coal burned is low quality with a high ash and sulfur content—a key componentof acid rain—producing high levels of air pollution. Forests in the Czech Republic are among the most seriously affected by acid rain in all of Europe....

• Bulgaria - country.

  E Climate Most of Bulgaria has a continental climate, with cold winters and hot summers. The climate in general is more severe than in other European areas of the samelatitudes, and the average annual temperature range is greater than that of neighboring countries. Severe droughts, frosts, winds, and hail storms frequently damagecrops. A Mediterranean climate, with dry summers and mild, humid winters, prevails in the valley of the southwestern Rhodope Mountains; the northern limit of theclimati...

• 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...

• Sewage Disposal.

  greater load on the piping system and the treatment plant. The amount of storm-water drainage to be carried away depends on the amount of rainfall as well as on the runoff or yield of the watershed ( see Drainage). A typical metropolitan area discharges a volume of wastewater equal to about 60 to 80 percent of its total daily water requirements, the rest being used for washingcars and watering lawns, and for manufacturing processes such as food canning and bottling. B Composition The composi...

• Tuberculosis.

  TB has existed for thousands of years. Scars on a skull found in Turkey indicate the presence of the disease 500,000 years ago. Scientists also have found tubercles inmummified bodies from ancient Egypt. References to TB can be found in the writings of ancient Babylonia, Egypt, and China. The term tuberculosis was first used in 1839; it was derived from the Latin word tubercula, meaning small lump, referring to the small scars seen in tissues of infected individuals. TB reappeared in Europe...

• Seoul - geography.

  higher learning in South Korea. All of South Korea’s top-ranked universities are in Seoul, including Chung-ang University (1918), Ewha Women’s University (1886),Korea University (1905), Seoul National University (1946), Sogang University (1960), Sung Kyun Kwan University (1938), and Yonsei University (1885). The National Museum features collections of Korean art and artifacts, and the National Science Museum showcases modern Korean technology. The National Library ofKorea, the country’s largest...

• Seoul - geography.

  Major arts centers include Sejong Cultural Center, the largest performing arts center in South Korea located in Sejongno in central Seoul. The Korea Traditional PerformingArts Center, which showcases traditional Korean music and dance, is in the Seocho district. VI RECREATION Biwon, or the Secret Garden, formerly a retreat for the Yi rulers of the Chosŏn dynasty, is now a public park occupying 32 hectares (80 acres) just north of ChangdeokPalace. Namsan Park, located on Namsan Mountain south of...

• Indian Music I INTRODUCTION Classical Dance of South India The southern Indian kathakali is a dance drama that dates from the 17th century.

  Sangita Ratnakara, was written in the 13th century. However, subsequent writers tended to focus on the emotional connotations of individual ragas, associating them with moods, performance times, colors, and deities, and grouping them in terms of families. The modern theoretical system began in the 16th century, when ragasbegan to be classified according to scale—72 in the Karnāṭak system and 10 principal ones in the Hindustani. The 72 mela, as the Karn āṭak scales are called, are derived thro...

• The Gambia - country.

  The population of The Gambia (2008 estimate) is 1,735,464, making it one of the least populous countries of Africa. Still, the country has a fairly high overall populationdensity of 174 persons per sq km (449 per sq mi), and the population is increasing at a rate of 2.7 percent a year. Banjul, formerly called Bathurst, is the capital andonly seaport. The largest city is Serrekunda, a transportation hub and commercial center. B Religion and Language The great majority of the people of The Gambia...

• Eye. I INTRODUCTION Eye, light-sensitive organ of vision in animals. The eyes of

  Several structures, not parts of the eyeball, contribute to the protection of the eye. The most important of these are the eyelids, two folds of skin and tissue, upper andlower, that can be closed by means of muscles to form a protective covering over the eyeball against excessive light and mechanical injury. The eyelashes, a fringe ofshort hairs growing on the edge of either eyelid, act as a screen to keep dust particles and insects out of the eyes when the eyelids are partly closed. Inside the...

• Immune System.

  The humoral immune response involves a complex series of events after antigens enter the body. First, macrophages take up some of the antigen and attach it to classII MHC molecules, which then present the antigen to T helper cells. The T helper cells bind the presented antigen, which stimulates the T helper cells to divide andsecrete stimulatory molecules called interleukins. The interleukins in turn activate any B lymphocytes that have also bound the antigen. The activated B cells then divide...

• 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...

• Invertebrate - biology.

  animals with a five-pointed design. They live in the sea and move with the help of tiny fluid-filled feet—another feature found nowhere else in the animal world. Zoologists recognize several different groups of worms. The phylum known as flatworms contains the simplest animals possessing heads. Nerves and sense organs areconcentrated in the head. Most flatworms are paper-thin and live in a variety of wet or damp habitats, including the digestive systems of other animals. Roundwormsrepresent anot...

• Invertebrate - biology.

  animals with a five-pointed design. They live in the sea and move with the help of tiny fluid-filled feet—another feature found nowhere else in the animal world. Zoologists recognize several different groups of worms. The phylum known as flatworms contains the simplest animals possessing heads. Nerves and sense organs areconcentrated in the head. Most flatworms are paper-thin and live in a variety of wet or damp habitats, including the digestive systems of other animals. Roundwormsrepresent anot...

• Honduras - country.

  A Principal Cities The capital and largest city of Honduras is Tegucigalpa (2006 estimate, 1,324,000), located in the south-central highlands region. The country’s second largest city isSan Pedro Sula (549,498). The principal city and commercial center in the north, it lies in the heart of the vast banana plantations on the Caribbean Sea. La Ceiba(127,590) and Puerto Cortés (90,161) are among the leading Caribbean ports. B Language and Religion Spanish is the official language and is spoken by...

• Ecuador - country.

  F Natural Resources Ecuador’s main mineral wealth is in petroleum. Other mineral resources of the country include gold, silver, copper, lead, and zinc. Forests cover 38.3 percent of thecountry. G Plants and Animals Along the northern part of the Ecuador coast, and within the inner portion of the southern coast, tropical jungles abound. In some places the jungles extend up theslopes of the Andes as wet, mossy forests. Dense forests cover both flanks of the Cordilleras, as well as the Oriente, u...

• Hungary - country.

  Northern Hungary lacks sufficient water, especially between July and October, when precipitation levels are typically low. Canals irrigate the Great Hungarian Plain,which is subject to drought. Because of the country’s mainly flat terrain, only limited water resources can be harnessed for hydroelectric power. F Environmental Issues Rapid industrialization in Hungary following World War II contributed significantly to a number of major environmental problems, including air, water, and soil pollu...

• Zimbabwe - country.

  contamination—especially from the dieldrin and DDT used in tsetse fly control—has significantly affected wildlife and human health. III PEOPLE AND SOCIETY OF ZIMBABWE In 2008 Zimbabwe’s population was estimated to be 12,382,920, giving the country a population density of 32 persons per sq km (83 per sq mi). With a birth rate of27 per 1,000 and a death rate of 22 per 1,000, Zimbabwe’s population growth rate is 0.6 percent. Life expectancy at birth was estimated at 40 years in 2008, downfrom 59...

• Middle East - Geography.

  though overall they have improved considerably since the 1970s. This variation reflects the different levels of wealth and development in countries of the Middle East. Inthe highly developed country of Israel the infant mortality rate was 8 deaths per 1000 live births in 1997. By comparison, the rate per 1000 live births was 71 in less-developed Egypt and 75 in Yemen. A Ethnic Groups and Languages Arabs make up the majority of the people of the Middle East, accounting for almost the entire popu...

• Atom - chemistry.

  Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions. A Atomic Number Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral,the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties ofthe atom. The ligh...

• Atom I INTRODUCTION Water Molecule A water molecule consists of an oxygen atom and two hydrogen atoms, which are attached at an angle of 105°.

  spontaneously break apart and change, or decay, into other atoms. Unlike electrons, which are fundamental particles, protons and neutrons are made up of other, smaller particles called quarks. Physicists know of six different quarks.Neutrons and protons are made up of up quarks and down quarks —two of the six different kinds of quarks. The fanciful names of quarks have nothing to do with their properties; the names are simply labels to distinguish one quark from another. Quarks are unique amo...

• Battle of Waterloo.

  In the meantime, Grouchy had failed to overtake Blücher's army. At about 10 PM on June 17, Grouchy's scouts informed him that the Prussians, instead of retreating east to Namur, had turned northwest, seeking apparently a juncture with Wellington. Grouchy's message of warning to Napoleon brought the reply, sent at 10 AM on June 18, that Grouchy should keep trying to make contact with the Prussians. Grouchy's pursuit was slovenly and unhurried, and he failed to locate the enemy. On the morning o...

• Diseases of Animals.

  infected animal. It may also spread in milk or in garbage that contains contaminated meat. Typical symptoms include blisters that appear on the mouth and feet;animals may become lame when their hooves degenerate. Canine distemper is a highly contagious disease caused by the paramyxovirus, which is transmitted in discharges from the nose and eyes. Symptoms begin with fever,malaise, and nasal and ocular discharges and may progress to convulsions and other nervous system disorders. Parvoviruses aff...

• Influenza.

  days and disappear in seven to ten days. However, coughing and fatigue may persist for two or more weeks. Death from influenza itself is rare. But influenza can aggravate underlying medical conditions, such as heart or lung disease. Invading influenza viruses produceinflammation in the lining of the respiratory tract, damage that increases the risk that secondary infections will develop. Common complications include bronchitis,sinusitis, and bacterial pneumonia, occurring most frequently in olde...

• Earthquake.

  III CAUSES Most earthquakes are caused by the sudden slip along geologic faults. The faults slip because of movement of the Earth’s tectonic plates. This concept is called theelastic rebound theory. The rocky tectonic plates move very slowly, floating on top of a weaker rocky layer. As the plates collide with each other or slide past eachother, pressure builds up within the rocky crust. Earthquakes occur when pressure within the crust increases slowly over hundreds of years and finally exceeds...

• 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...

• 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...

• Cambodia - country.

  The population of Cambodia is 14,241,640 (2008 estimate). Population growth per year is estimated at 1.8 percent, one of the highest rates in Asia. The rate of infantmortality is also high. The population density is 81 persons per sq km (209 per sq mi), with the densest concentrations on the heavily cultivated central plain. Themountainous regions of the country, where malaria is widespread, are thinly populated, as are the poorly watered northern provinces. During the late 1970s, under thebruta...

• 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...