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AOL ... Aphanomyces
AOL
one of the largest Internet-access subscription service companies in the United States, providing a range of Web services for users. AOL was one of the first companies to establish a strong sense of community among its users through buddy lists and instant messaging services, which transmit billions of messages daily.
Aomori
northernmost ken (prefecture) on the island of Honshu, Japan. It is bordered by the Pacific Ocean (east), the Tsugaru Strait (north), and the Sea of Japan (East Sea; west). The peninsulas of Tsugaru and Shimokita enclose Mutsu Bay. Aomori has a relatively poor agricultural economy that is handicapped by long, ...
Aomori
city and capital of Aomori ken (prefecture), Japan, located on Aomori Bay. One of Japan's most important transportation centres, it is the terminus of both northern Honshu rail lines and railroad ferry services across the Tsugaru Strait to Hakodate, on Hokkaido. The Tohoku Highway and Seikan Tunnel facilitate communication between ...
Aoraki/Mount Cook National Park
park, west-central South Island, New Zealand. Established in 1953, it has an area of 273 square miles (707 square km) and has a common western boundary with Westland National Park. The park extends for about 40 miles (65 km) along the crest of the Southern Alps. At the park's widest ...
Aornos, Siege of
(327 BC), conflict in which Alexander the Great seized a nearly impregnable natural stronghold blocking his route to India. Aornos is evidently modern Pir Sarai, a steep ridge a few miles west of the Indus and north of the Buner rivers in modern Pakistan. Unable to storm the rock, Alexander ...
aorta
in vertebrates and some invertebrates, the blood vessel (or vessels) carrying blood from the heart to all the organs and other structures of the body.
aorta, coarctation of the
congenital malformation involving the constriction, or narrowing, of a short section of that portion of the aorta that arches over the heart. The aorta is the principal artery conducting blood from the heart into the systemic circulation. The partial obstruction of the aortic channel causes a characteristic murmur and causes ...
aortic arch syndrome
group of disorders that cause blockage of the vessels that branch off from the aorta in the area in which the aorta arches over the heart. The aorta is the principal vessel through which the heart pumps oxygen-rich blood into the systemic circulation. The aortic branches that may be affected ...
aortic insufficiency
failure of the valve at the mouth of the aorta-the principal artery that distributes blood from the heart to the tissues of the body-to prevent backflow of blood from the aorta into the left lower chamber (ventricle) of the heart, from which it has been pumped. The defect causes characteristic ...
aortic stenosis
narrowing of the passage between the left lower chamber (ventricle) of the heart and the aorta, the principal artery of the systemic circulation. The defect is most often in the valve at the mouth of the aorta but may be just above or below the valve (supravalvular and subvalvular aortic ...
Aosta
city, capital of Valle d'Aosta region, northwestern Italy, at the confluence of the Buthier and Dora Baltea rivers and commanding the Great and Little St. Bernard pass roads, north-northwest of Turin. It was a stronghold of the Salassi, a Celtic tribe that was subdued by the Romans in 25 BC, ...
aoudad
North African goatlike mammal of the family Bovidae (order Artiodactyla). This species has been inappropriately called a sheep, although recent genetic information reveals that it is much more closely related to wild goats. The aoudad stands about 102 cm (40 inches) at the shoulder. It has a fringe of long, ...
Aouelloul Crater
large crater located 28 mi (45 km) southwest of Chinguetti, Mauritania, and thought to be of meteoritic origin. Discovered by air in 1951, it is 833 ft (250 m) in diameter and 33 ft in depth. A large amount of fused silica glass has been found in the area, but ...
Aozou Strip
northernmost part of Chad, a narrow strip of territory that extends along the country's entire border with Libya. The Aozou Strip has an area of about 44,000 square miles (114,000 square km) and consists almost entirely of the Sahara desert. The Tibesti Mountains interrupt the desert in the northwest, near ...
Apa River
river rising in the Amambai Mountains in southwestern Brazil, forming the Brazil-Paraguay border. It flows for about 160 miles (260 km) in a northwesterly direction to join the Paraguay River at the city of Corumba.
Apa Sherpa
Nepali mountaineer and guide who was best known for having achieved the most ascents of Mount Everest.
Apa Tani
tribal people of Arunachal Pradesh (former North East Frontier Agency), a mountainous state in the extreme northeast of India. They speak a Tibeto-Burman language of the Sino-Tibetan family and numbered about 13,100 in the 1970s.
Apabhramsha language
literary language of the final phase of the Middle Indo-Aryan languages. When the Prakrit languages were formalized by literary use, their variations came to be known as Apabhramsha. Despite this close relationship, scholars generally treat Apabhramsha and the nonliterary Prakrits separately.
Apache
North American Indians who, under such leaders as Cochise, Mangas Coloradas, Geronimo, and Victorio, figured largely in the history of the Southwest during the latter half of the 19th century. Their name is probably derived from a Spanish transliteration of apachu, the term for "enemy" in Zuni.
Apache
an open-source Web server created by American software developer Robert McCool. Apache was released in 1995 and quickly gained a majority hold on the Web server market. Apache provides servers for Internet giants such as Google and Wikimedia projects such as Wikipedia. In the early 21st century, Apache servers deployed ...
Apadana
collection of legends about Buddhist saints, one of the latest books in the latest section (the Khuddaka Nikaya) of the Sutta Pitaka ("Basket of Discourse") of the Pali canon. This work, which is entirely in verse, presents stories about 547 monks and 40 nuns. For each personage there are tales ...
Apalachee
tribe of North American Indians who spoke a Muskogean language and inhabited the area in northwestern Florida between the Aucilla and Apalachicola rivers above Apalachee Bay. In the 16th century the Spanish explorers Panfilo de Narvaez (in 1528) and Hernando de Soto (in 1539) led expeditions to Apalachee territory.
Apalachee Bay
arm of the Gulf of Mexico indenting the coast of northern Florida, U.S., 25 miles (40 km) south of Tallahassee. It receives the Ochlockonee, St. Marks, Econfina, and Aucilla rivers, and its marshy coast forms St. Marks National Wildlife Refuge. In 1528 five boats were built in the bay by ...
Apalachicola
city, seat (1832) of Franklin county, northwestern Florida, U.S. It lies on Apalachicola Bay (bridged) at the mouth of the Apalachicola River, on the Intracoastal Waterway, about 80 miles (130 km) southwest of Tallahassee.
Apamea Cibotus
city in Hellenistic Phrygia, partly covered by the modern town of Dinar, Tur. Founded by Antiochus I Soter in the 3rd century BC, it superseded the ancient Celaenae and placed it in a commanding position on the great east-west trade route of the Seleucid Empire. In the 2nd century BC ...
Apanas, Lake
reservoir in northern Nicaragua. Formed by damming the Tuma River just north of Jinotega city, Lake Apanas has an area of 20 square miles (51 square km). It supplies the Asturias hydroelectric station, the largest in the country and the focus of a power grid serving much of the more ...
apapane
(Himatione sanguinea), Hawaiian songbird, common on larger islands, a nectar-feeding member of the Hawaiian honeycreeper family, Drepanididae (order Passeriformes). About 13 centimetres (5 inches) long, it is red, except for its dark wings and tail and its white vent. Its bill is fairly short and slightly curved. The apapane lives ...
Apapocuva
a Guarani-speaking South American Indian people living in small, scattered villages throughout the Mato Grosso, Parana, and Sao Paulo states of southeastern Brazil. In the second half of the 20th century, the Apapocuva probably numbered fewer than 500 individuals.
Aparicio, Luis
professional baseball player who was known for his outstanding fielding, speed on the base paths, and durability. Aparicio appeared in 2,581 games at shortstop, more than any other player in the history of American professional baseball.
Aparimitayus-sutra-shastra
in Buddhism, a short treatise (shastra) on the Aparimitayus-sutra, one of the major Pure Land sutras, by the Indian monk Vasubandhu (flourished 5th century CE). It expresses the author's personal devotion to Amitabha, the celestial Buddha of Infinite Light, and his desire for rebirth in the Western Paradise, or Amitabha's ...
Aparri
town, northeastern Luzon, Philippines. It lies along the Babuyan Channel of the Philippine Sea, near the mouth of the Cagayan River. Aparri is the interisland port for much of northeastern Luzon. Anti-Spanish insurgents landed there in 1898 under Colonel Daniel Tirona, and civil government was restored in 1901 under the ...
apartheid
policy that governed relations between South Africa's white minority and nonwhite majority and sanctioned racial segregation and political and economic discrimination against nonwhites. The implementation of apartheid, often called "separate development" since the 1960s, was made possible through the Population Registration Act of 1950, which classified all South Africans as ...
apartment house
building containing more than one dwelling unit, most of which are designed for domestic use, but sometimes including shops and other nonresidential features.
Apartments of the Rainforest
Tree hollows are sought-after refuges for a succession of creatures, from termites to primates. Tree hollows make safe nests and dens where mothers can raise their young protected from predators and where roosting birds and various mammals can take shelter during the day.
apathy
in Stoic philosophy, condition of being totally free from the pathe, which roughly are the emotions and passions, notably pain, fear, desire, and pleasure. Although remote origins of the doctrine can probably be found in the Cynics (second half of the 4th century BC), it was Zeno of Citium (4th-3rd ...
apatite
any member of a series of phosphate minerals, the world's major source of phosphorus, found as variously coloured glassy crystals, masses, or nodules. If not for its softness (Mohs hardness 5, compared with the 7 to 9 of most gems), apatite would be a popular gemstone; much of the material ...
Apatosaurus
giant herbivorous sauropod dinosaur, one of the largest land animals of all time, that lived between 147 million and 137 million years ago during the Late Jurassic and Early Cretaceous periods. Its fossil remains are found in North America and Europe.
Apatow, Judd
American writer, director, and producer known for creating offbeat comedies featuring unconventional protagonists.
Apaturia
Greek religious festival that was held annually in nearly all the Ionian towns. At Athens it took place in the month of Pyanopsion (October-November) and lasted three days, on which occasion the various phratries (clans) of Attica met to discuss their affairs. The name probably means the festival of "common ...
Apatzingan
city, west-central Michoacan estado (state), west-central Mexico. It lies along the Apatzingan (Acahuato) River, 176 miles (283 km) southwest of Morelia, the state capital. Its name commemorates the signing there in 1814 of the Constitution of Apatzingan by the congress called by the revolutionary leader Jose Maria Morelos to declare ...
Apausha
in ancient Iranian religion, a demonic star who in an important myth does battle with Tishtrya over rainfall.
ape
any tailless primate of the families Hylobatidae (gibbons) and Hominidae (chimpanzees, bonobos, orangutans, gorillas, and human beings). Apes are found in the tropical forests of western and central Africa and Southeast Asia. Apes are distinguished from monkeys by the complete absence of a tail and the presence of an appendix ...
Apeldoorn
gemeente (municipality), east-central Netherlands. It lies east of the sandy and wooded Veluwe Hills, on the edge of the Soeren (Suren) Forest. Noted traditionally for its many gardens, paper mills, and laundries, Apeldoorn is a residential and industrial town that manufactures pharmaceuticals, chemicals, and refrigeration machinery. There are many sanitariums ...
apella
ancient Spartan assembly, corresponding to the ekklesia of other Greek states. Its monthly meetings, probably restricted to full citizens over 30, were presided over at first by the kings, later by ephors (magistrates). Not empowered to initiate proposals, the body considered subjects forwarded by the ephors or gerousia (council of ...
Apelles
early Hellenistic Greek painter whose work was held in such high esteem by ancient writers on art that he continues to be regarded, even though none of his work survives, as the greatest painter of antiquity.
Apellicon Of Teos
a wealthy Greek book collector, who became an Athenian citizen. He had bought from the descendants of Neleus of Scepsis in the Troad the libraries of Aristotle and Theophrastus, which were in a damaged condition but might have contained the only copies of the Aristotelian treatises to survive. Apellicon is ...
Apennine Range
series of mountain ranges bordered by narrow coastlands that form the physical backbone of peninsular Italy. From Cadibona Pass in the northwest, close to the Maritime Alps, they form a great arc, which extends as far as the Egadi Islands to the west of Sicily. Their total length is approximately ...
aperture
in optics, the maximum diameter of a light beam that can pass through an optical system. The size of an aperture is limited by the size of the mount holding the optical component, or the size of the diaphragm placed in the bundle of light rays. The hole in the ...
Apgar Score System
medical rating procedure developed in 1952 by American anesthesiologist Virginia Apgar to evaluate the condition of newborn infants and to identify those that require life-sustaining medical assistance, such as resuscitation. The Apgar score is a qualitative measurement of a newborn's success in adapting to the environment outside the uterus.
Apgar, Virginia
American physician, anesthesiologist, and medical researcher who developed the Apgar Score System, a method of evaluating an infant shortly after birth to assess its well-being and to determine if any immediate medical intervention is required.
Aphanomyces
genus of parasitic fungi in the class Oomycetes (phylum Oomycota, kingdom Chromista) that forms two successive asexual, motile spores (zoospores). The first one is produced in a spore sac (sporangium) but soon forms a cyst from which the second zoospore arises. The latter, on contact, infects a susceptible host plant. ...