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orthodontics ... Osborn, Mount
orthodontics
division of dentistry dealing with the prevention and correction of irregularities of the teeth-generally entailing the straightening of crooked teeth or the correcting of a poor bite, or malocclusion (physiologically ... [1 Related Articles]
orthodox
(from Greek orthodoxos, "of the right opinion"), true doctrine and its adherents as opposed to heterodox or heretical doctrines and their adherents. The word was first used in early 4th-century ...
Orthodox Church in America
ecclesiastically independent, or autocephalous, church of the Eastern Orthodox communion, recognized as such by its mother church in Russia; it adopted its present name on April 10, 1970. [2 Related Articles]
Orthodox Church of Albania
(from the article "Albania") ...of the Roman pope until 732. In that year the iconoclast Byzantine emperor Leo III, angered by Albanian archbishops because they had supported Rome in the Iconoclastic Controversy, detached the ...
Orthodox Church of Constantinople
(from the article "Nestorius") early bishop of Constantinople whose views on the nature and person of Christ led to the calling of the Council of Ephesus in 431 and to Nestorianism, one of the ...
Orthodox Church of Czechoslovakia
autocephalous, or ecclesiastically independent, member of the Eastern Orthodox communion, created in 1951 by the patriarchate of Moscow. [2 Related Articles]
Orthodox Church of Finland
Eastern Orthodox church, recognized as the second state church of Finland. Most of the Orthodox Finns were originally from Karelia, the southeastern part of Finland that was annexed by the ... [2 Related Articles]
Orthodox Church of Poland
ecclesiastically independent member of the Eastern Orthodox communion, established in 1924 to accommodate the 4,000,000 Orthodox Christians residing in the vast Ukrainian and Byelorussian territories acquired by Poland after World ...
Orthodox Jewish Congregations of America, Union of
official federation of Jewish Orthodox synagogues in the United States and Canada; its counterpart organization for rabbis is the Rabbinical Council of America. [1 Related Articles]
Orthodox Judaism
the religion of those Jews who adhere most strictly to traditional beliefs and practices. Jewish Orthodoxy resolutely refuses to accept the position of Reform Judaism that the Bible and other ... [14 Related Articles]
Orthodox Presbyterian Church
(from the article "Machen, John Gresham") ...revision of the 17th-century English Presbyterian creed, the Westminster Confession. Following his suspension from the ministry, he helped found the Presbyterian Church in America, which became the Orthodox Presbyterian Church ...
Orthodox, Baptistery of the
(from the article "mosaic") ...of this trend are the flaming visages of angels in Sta. Maria Maggiore, Rome (c. AD 432-440) and the spiritualized physiognomies of St. Bartholomew and his fellow apostles in the ...
Orthodoxy, Autocracy, and Nationality
in Russian history, slogan created in 1832 by Count Sergey S. Uvarov, minister of education 1833-49, that came to represent the official ideology of the imperial government of Nicholas I ... [3 Related Articles]
Orthodoxy, Feast of
feast celebrated on the first Sunday of Lent by the Eastern Orthodox Church and Eastern Catholics of the Byzantine Rite to commemorate the return of icons (sacred images) to the ... [4 Related Articles]
orthoferrosilite
(from the article "pyroxene") The most common pyroxenes can be represented as part of the chemical system CaSiO3 (wollastonite, a pyroxenoid), MgSiO3 (enstatite), and FeSiO3 (ferrosilite). Since no true pyroxenes exist with calcium contents ...
orthogenesis
theory that successive members of an evolutionary series become increasingly modified in a single undeviating direction. That evolution frequently proceeds in orthogenetic fashion is undeniable, though many striking features developed ...
Orthognatha
(from the article "spider") ...low; overpower web-entangled prey; Loxosceles reclusa (brown recluse) and Loxosceles laeta venomous to humans.2,000 to 3,000 species; most species large and long-lived in warm climates. 2 pairs ...
orthogneiss
(from the article "gneiss") Gneiss can be classified on the basis of minerals that are present, presumed formational processes, chemical composition, or probable parent material. Orthogneiss is formed by the metamorphism of igneous rocks; ...
orthogonal array
(from the article "combinatorics") A k × N matrix A with entries from a set X of s ⪖ 2 symbols is called an orthogonal array of strength t, size N, k constraints, and ...
orthogonal Latin squares
(from the article "combinatorics") ...cells of which are occupied by k distinct symbols of a set X = 1, 2, . . . , k, such that each symbol occurs once in each row ...
orthogonal trajectory
family of curves that intersect another family of curves at right angles (orthogonal; see ). Such families of mutually orthogonal curves occur in such branches of physics as electrostatics, in ...
orthographic projection
common method of representing three-dimensional objects, usually by three two-dimensional drawings, in each of which the object is viewed along parallel lines that are perpendicular to the plane of the ... [2 Related Articles]
orthography
(from the article "Baltic languages") The Lithuanian alphabet is based on the Roman (Latin) alphabet. It has 33 letters, several employing diacritical marks, and is phonetic. In linguistic literature an acute accent is used for ...
orthokinesis
(from the article "animal behaviour") ...a stimulus) and kinesis (undirected response proportional to the intensity of a stimulus). These two types of behaviour-most often descriptive of invertebrates-may be further subdivided. Orthokinesis, for example, is a ...
orthometric correction
(from the article "surveying") ...increase in the force of gravity at higher latitudes), the distances between the surfaces and the geoid do not exactly represent the surfaces' heights from the geoid. To correct these ...
orthomyxovirus
(from the article "virus") ...in envelope give crownlike (coronal) appearance. Viruses of this family are important agents of gastrointestinal disease in humans, poultry, and bovines.Enveloped virions about 60 to 300 nm in diameter ...
orthonectid
(from the article "orthonectid") any of a class (Orthonectida) of rare wormlike parasites of various marine invertebrates, including bivalved mollusks and polychaete annelids; they are usually included in the phylum Mesozoa, a group regarded ...
Orthonotia
(from the article "bivalve") ...attachment and a trend toward loss of the anterior adductor muscle. The common mussels (family Mytilidae) are thought to be derived from an extinct group, the family Modiomorphidae. The subclass ...
Orthonychidae
(from the article "passeriform") ...singers, musical whistles and fluty notes. 3 genera, 14 species in forests and cultivated lands from India to Philippines, south to Borneo, Java, Sumatra.Medium-sized terrestrial birds, ...
orthopedic device
(from the article "materials science") Joint replacements, particularly at the hip, and bone fixation devices have become very successful applications of materials in medicine. The use of pins, plates, and screws for bone fixation to ...
orthopedics
medical specialty concerned with the preservation and restoration of function of the skeletal system and its associated structures, i.e., spinal and other bones, joints, and muscles. [3 Related Articles]
orthophotoscope
(from the article "surveying") A much more precise technique is based on the use of an orthophotoscope. With this device, overlapping photographs are employed just as in the stereoscopic plotter already described, but the ...
orthopnea
(from the article "cardiovascular disease") ...extremities (e.g., the legs), large amounts of fluid become mobilized, resulting in rapid expansion of the blood volume and in shortness of breath. Shortness of breath on lying down is ...
orthopositronium
(from the article "positronium") ...are oppositely directed, decays by annihilation into two photons, with a mean life of about one-tenth of a nanosecond (or 10-10 second; a nanosecond is 10−9 second); and orthopositronium, in ...
orthopteran
broadly, any member of one of four insect orders. Orthopteran has come to be regarded as the common name for these related groups, which exhibit considerable morphological, physiological, and paleontological ... [2 Related Articles]
orthopyroxene
any of a series of common silicate minerals in the pyroxene family. Orthopyroxenes typically occur as fibrous or lamellar (thin-plated) green masses in igneous and metamorphic rocks and in meteorites. [3 Related Articles]
orthopyroxene granite
(from the article "orthopyroxene granite") member of the charnockite (q.v.) series of metamorphic rocks.for more general content related to this topiccharnockite
Orthoreovirus
(from the article "virus") ...nm in diameter and containing double-stranded RNA in 10 to 12 segments. Viruses in this family infect many species of plants and animals. The animal Reoviridae are divided into 4 ...
orthorhombic system
one of the structural categories systems to which crystalline solids can be assigned. Crystals in this system are referred to three mutually perpendicular axes that are unequal in length. If ... [8 Related Articles]
orthostat
(from the article "Anatolian religion") The traditional Hittite iconography survived but was gradually permeated by Aramaic and Assyrian influences. Orthostats (stone slabs set at the base of a wall) from Malatya on the Euphrates show ...
orthostatic hypotension
(from the article "hypotension") Orthostatic hypotension-low blood pressure upon standing up-seems to stem from a failure in the autonomic nervous system. Normally, when a person stands up, there is a reflex constriction of the ...
orthotopic graft
(from the article "transplant") Tissue or organ grafts may be transplanted to their normal situation in the recipient and are then known as orthotopic-for example, skin to the surface of the body. Alternatively, they ...
orthotropism
(from the article "tropism") ...thigmotropism (response to mechanical stimulation), traumatotropism (response to wound lesion), and galvanotropism, or electrotropism (response to electric current). Most tropic movements are orthotropic; i.e., they are directed toward the source ...
Orthurethra
(from the article "gastropod") ...at most narrowly separated; shell conical to vestigial, heavily to weakly calcified; eyes at tips of upper (usually) tentacles; terrestrial; about 26,800 species.Pore of ureter opening into mantle cavity ...
Ortigao, Jose Duarte Ramalho
Portuguese essayist and journalist known for his mastery of Portuguese prose and his critical reflections on his native land.
Ortigoza, Napoleon
(from the article "Paraguay") ...to grant Stroessner a state funeral. The government said it would seek to confiscate Stroessner's personal fortune, believed to be at least $500 million. Less noted was the death in ...
Ortiz Mena, Antonio
Mexican politician was credited with fueling Mexico's phenomenal growth (about 6% annually) while serving as the country's finance minister (1958-70). Ortiz Mena, a lawyer by profession, held a variety ...
Ortiz, David
(from the article "Baseball") ...of the Pittsburgh Pirates claimed the NL batting title with a mark of .344. Ryan Howard of the Philadelphia Phillies led the NL with 58 home runs and 149 runs ...
Ortiz, Fernando
anthropologist, essayist, and philologist who pioneered in the study of neo-African cultures in the Americas, particularly in Cuba.
Ortiz, Jose Domingo
(from the article "El Banco") ...called it Barbudo ("Bearded One") because of its bearded chief. In 1544 Alonzo de San Martin renamed it Tamalameque (now the name of a town a few miles to the ...
Ortiz, Roberto M.
(from the article "Argentina") The election of 1937, in which the government retained its power, was marked by fraud and violence; however, the next president, Roberto M. Ortiz, returned to more proper electoral procedures, ...
ortolan
(Emberiza hortulana), Eurasian garden and field bird of the subfamily Emberizinae, family Fringillidae. It grows fat in autumn, when large flocks gather for migration to northern Africa and the Middle ...
Ortoli, Francois-Xavier
French politician was president (1973-77) of the European Commission (EC; part of what later became the European Union) during a period of social upheaval and the entry of three new ...
Orton, Edward, Jr.
(from the article "pottery") A close study of the technical side of manufacture was not undertaken until Edward Orton, Jr., succeeded in getting support for the establishment of a department of ceramics at Ohio ...
Orton, Harold
(from the article "linguistics") ...for instance, are now working on regional atlases that will complement data contained in the Atlas linguistique de la France. In England, work began in 1946, under the direction of ...
Orton, Joe
British playwright noted for his outrageous and macabre farces. [1 Related Articles]
Ortona
town, Abruzzi region, central Italy, on a promontory 230 feet (70 m) above sea level, on the Adriatic coast, about 11 miles (18 km) southeast of Pescara. An ancient settlement, ...
Ortstock
(from the article "Schwyz") ...about 25 square miles (65 square km) are occupied by lakes, chiefly parts of Lakes Zurich and Lucerne, a small area of Lake Zug, and the whole of Lakes Lauerz ...
Ortygia
(from the article "Syracuse") Syracuse's nucleus is formed by the southward-projecting island of Ortygia, which half-encloses the bay known as the Great Harbour. The remains of antiquity on the continuously inhabited Ortygia are less ...
Orumiyeh
city, extreme northwestern Iran. It lies just west of Lake Urmia on a large fertile plain that yields grains, fruits, tobacco, and other crops. The population is mainly Azeri Turkish, ...
Oruro
city, west-central Bolivia. It lies at 12,150 feet (3,702 metres) above sea level in the Altiplano region, 30 miles (48 km) north of Poopo Lake. Founded in 1606 as Real ... [2 Related Articles]
Orvieto
town, Umbria regione, central Italy. The town is situated atop an isolated rock 640 feet (195 m) above the junction of the Paglia and Chiana rivers. An Etruscan and later ... [1 Related Articles]
Orvieto Cathedral
(from the article "Maitani, Lorenzo") Italian architect and sculptor primarily responsible for the construction and decoration of the facade of Orvieto Cathedral.descriptionOrvietoOrvieto's Gothic cathedral, which ...
Orvieto ware
Italian maiolica, a tin-glazed earthenware produced originally at Orvieto, in Umbria, from the 13th century onward. It was copied from, or inspired by, the faience produced in Paterna, Spain. The ... [1 Related Articles]
Orvilos, Mount
(from the article "Greece") ...the Rhodope (Rodhopis) Mountains, composed mainly of sharp-edged and frequently sloping plateaus, often rising more than 7,000 feet (1,800 metres) and reaching 7,287 feet (2,212 metres) at Mount Orvilos. The ...
Orwell, George
English novelist, essayist, and critic famous for his novels Animal Farm (1945) and Nineteen Eighty-four (1949), the latter a profound anti-Utopian novel that examines the dangers of totalitarian rule. [8 Related Articles]
Ory, Kid
American trombonist and composer who was perhaps the first musician to codify, purely by precept, the role of the trombone in classic three-part contrapuntal jazz improvisation. Ory is often remembered ... [2 Related Articles]
Oryctes nasicornis
(from the article "rhinoceros beetle") ...(Xyloryctes jamaicensis) is a dark brown scarab a little over 25 mm (1 inch) long. The male possesses a single upright horn; the female has only a small tubercle. One ...
Oryol
oblast (region), western Russia. It occupies an area of rolling hills of the Central Russian Upland, into which are cut many broad, shallow river valleys. The greater ...
Oryol
city and administrative centre of Oryol oblast (region), western Russia. It is located on the headwaters of the Oka River at its confluence with the Orlik River. ... [1 Related Articles]
oryx
(genus Oryx), any of four large antelopes (family Bovidae, order Artiodactyla) living in herds on deserts and dry plains of Africa and Arabia. [1 Related Articles]
Oryx gazella
(from the article "oryx") The beisa and gemsbok, subspecies of O. gazella, inhabit eastern and southern Africa, respectively. The scimitar oryx (O. dammah), once found throughout northern Africa, was restricted to the southern rim ...
Oryzoideae
(from the article "Poaceae") A peripheral subgroup of the Bambusoideae is sometimes segregated as the subfamily Oryzoideae owing to the distinctive spikelets and aquatic or wetland herbaceous habit of these tropical and warm-temperate plants. ...
Oryzomys alfaroi
(from the article "rice rat") ...to grayish brown upperparts and paler underparts. Their tails are sparsely haired and vary in length depending upon the species. Body size also varies. Among the smallest is
Oryzomys angouya
(from the article "rice rat") ...Oryzomys alfaroi, from southern Mexico to western Ecuador, with a body up to 12 cm (4.7 inches) long and a slightly shorter tail; among the largest is
Oryzomys bolivaris
(from the article "rice rat") ...for example, O. megacephalus and O. yunganus are restricted to lowland tropical rainforests of the Amazon Basin, and O. bolivaris is ...
Oryzomys megacephalus
(from the article "rice rat") ...to cloud forests in the mountains of southern Mexico, Central America, and the Andes. Certain rice rats are indigenous to particular biogeographic regions; for example, O. megacephalus ...
Oryzomys yunganus
(from the article "rice rat") ...Mexico, Central America, and the Andes. Certain rice rats are indigenous to particular biogeographic regions; for example, O. megacephalus and O. yunganus are restricted ...
Orzeszkowa, Eliza
Polish novelist and a leading writer of the Positivist period (the Polish Positivists took their name from Auguste Comte's philosophy but were themselves mainly utilitarians). Questions of education, independence, and ... [1 Related Articles]
os basale
(from the article "Gymnophiona") ...and compact. Centres of ossification have fused, which has reduced the number of independent cranial bones in caecilians in comparison with anurans and salamanders; for example, a single bone, the ...
Os Mutantes
(from the article "Performing Arts") In Brazil musicians also mixed revival and experiment. Members of Os Mutantes, the rock band that had been hailed as Brazil's answer to the Beatles in the '60s, released a ...
os resectum
(from the article "death rite") ...suggests that the rest of the body was not ritually buried. The Egyptians removed the viscera, which were preserved separately in four canopic jars. The Romans observed the curious rite ...
Osa
city and administrative centre of Osa rayon (sector), Perm oblast (province), Russia, on the left bank of the Kama River near its confluence with the Tulva River. The city is ...
Osa Peninsula
peninsula, southern Costa Rica, bounded on the northwest by Coronado Bay, on the west by the Pacific Ocean, and on the east by the Gulf of Dulce. Costa Rica's second ...
Osaces
(from the article "Pacorus") In the summer of 51 BC Pacorus was sent to invade Syria with an army commanded by Osaces, an older warrior. Osaces, however, was killed in battle, and early the ...
Osage
North American Indian tribe of the Dhegiha branch of the Siouan linguistic stock. The name Osage is a French alliteration of the name Wazhazhe, one of the two ancient kin ... [3 Related Articles]
Osage orange
(Maclura pomifera), thorny tree with large, yellow-green, wrinkled fruit and a milky sap that can produce dermatitis in humans. It is the only species of its genus in the mulberry ...
Osage River
river rising as the Marais des Cygnes (French: "Swan Marshes") in the Flint Hills near Eskridge, Kan., U.S. It becomes the Osage (named for the Osage Indians) after its junction ... [1 Related Articles]
Osagyefuo Kuntunkununku II
Ghanaian Okyehene (ruler) of the Akim Abuakwa traditional area and president of the advisory National House of Chiefs (1998-99). Born Alex Agyeman, the son of a businessman, he studied medicine ...
Osaka
fu (urban prefecture), Honshu, Japan. It is bordered by Kyoto urban prefecture (north) and by the ken (prefectures) of Hyogo (northwest), Nara (east), and ... [1 Related Articles]
Osaka
city and capital of Osaka fu (urban prefecture), south-central Honshu, Japan. The city, together with its neighbouring city Kobe and nearby Kyoto, are the centres of the Keihanshin Industrial Zone, ... [6 Related Articles]
Osaka Action Agenda
(from the article "Asia-Pacific Economic Cooperation") ...achieving a free trade and investment regime in the Asia-Pacific region by 2010 for members with developed economies and by 2020 for members with developing ones. The following year it ...
Osaka Bay
(from the article "Osaka-Kobe metropolitan area") ...into their diluvial uplands. The area is bounded by the Ikoma Mountains in the east, the Izumi Mountains in the south, and the Rokko Mountains in the northwest. The southwestern ...
Osaka Castle
(from the article "Osaka-Kobe metropolitan area") The city of Osaka is situated on the delta of the Yodo River. To the east of the central city, Osaka Castle, originally built by Toyotomi Hideyoshi, stands on a ...
Osaka Spinning Company
(from the article "Shibusawa Eiichi, Shishaku") ...National Bank (present-day Daiichi Kangyo Bank) of Japan, which he had helped found. That same year he founded the Oji Paper Manufacturing Company, and 10 years later he began the ...
Osaka World's Fair
(from the article "building construction") ...plastic membranes, which were devised by Walter Bird of Cornell University in the late 1940s and were soon in use for swimming pools, temporary warehouses, and exhibition buildings. The Osaka ...
Osaka-Kobe metropolitan area
second largest urban and industrial agglomeration in Japan, located on Osaka Bay in west-central Honshu at the eastern end of the Inland Sea. The cities of Osaka and Kobe are ...
Osasco
city, southeastern Sao Paulo estado (state), Brazil. Located at 2,360 feet (720 m) above sea level, Osasco lies along the Tiete River. It is just northwest of Sao Paulo city, ...
Osawatomie
city, Miami county, eastern Kansas, U.S. It lies along the Marais des Cygnes River at the mouth of Pottawatomie Creek; its name combines elements of the words Osage and Pottawatomie. ...
Osborn, Henry Fairfield
American paleontologist and museum administrator who greatly influenced the art of museum display and the education of paleontologists in the United States and Great Britain. [1 Related Articles]
Osborn, Mount
(from the article "Alaskan mountains") ...consists of broad, convex hills and ridges with an average elevation of about 2,000 feet surmounted by more rugged mountain groups. A few peaks rise above 3,000 feet; the highest, ...