(from the article "Hypsipyle") ...sons to the Argonaut Jason. When the other women learned that she had spared her father, she was deposed and sold into slavery to Lycurgus, king of Nemea. One day, ...
brass wind musical instrument with a cup-shaped mouthpiece and padded keys, the bass version of the old keyed bugle. The name (from Greek ophis and kleid, "serpent" and "key") alludes ... [1 Related Articles]
(from the article "avoidance behaviour") ...in isolation respond to man-made models with appropriate eyespots painted on. It has been suggested that many human beings are specifically (and perhaps instinctively) disturbed by the sight of snakes-the ...
(from the article "echinoderm") ...Cambrian about 570,000,000 years ago; pear-shaped or spindle-shaped body with many plates arranged spirally.Lower Ordovician to Upper Silurian about 395,000,000-500,000,000 years ago; dome-shaped body partly or completely covered by ...
only family in the fern order Ophioglossales, a primitive group of ferns. The family contains four genera and about 80 species. Its members are characterized by leaves (fronds) that are ... [1 Related Articles]
(from the article "igneous rock") ...ultramafics. The sequences consisting of layer 1 (limestone and chert sedimentary rocks), layer 2 of MORB lavas and dikes, and layer 3 of gabbro and diorite and the ultramafic rocks ...
(from the article "fungus") ...ascomata; included in subclass Sordariomycetidae; examples of genera include Diaporthe, Gnomonia, Cryphonectria, and Valsa.Pathogenic on plants, causing diseases such as Dutch elm disease and oak wilt; long, tubular ascomata ...
unidentified region famous in Old Testament times for its fine gold. The geographic list of Genesis 10 apparently places it in Arabia, but in the time of Solomon (c. 920 ... [2 Related Articles]
(from Greek ophis, "serpent"), member of any of several Gnostic sects that flourished in the Roman Empire during the 2nd century AD and for several centuries thereafter. A variety of ... [2 Related Articles]
(from the article "diabase") ...is mostly pyroxene or hornblende. In diabase, poorly formed pyroxene crystals wrap around or mold against long, rectangular plagioclase crystals to give it the characteristic texture known as diabasic or ...
genus of orchids, family Orchidaceae, containing approximately 30 species of plants native to Eurasia and North Africa. All have metallic-coloured, hairy flowers that resemble insects. Each plant is less than ... [2 Related Articles]
(from the article "nervous system, human") The ophthalmic nerve passes through the wall of the cavernous sinus and enters the orbit via the superior orbital fissure. Branches in the orbit are (1) the lacrimal nerve, serving ...
medical specialty dealing with the diagnosis and treatment of diseases and disorders of the eye. The first ophthalmologists were oculists. These paramedical specialists practiced on an itinerant basis during the ... [3 Related Articles]
(from the article "Helmholtz, Hermann von") Among Helmholtz' most valuable inventions were the ophthalmoscope and the ophthalmometer (1851). While doing work on the eye, and incidentally showing that it was a rather imperfect piece of workmanship ...
paralysis of the extraocular muscles that control the movements of the eye. Ophthalmoplegia usually involves the third (oculomotor), fourth (trochlear), or sixth (abducens) cranial nerves. Double vision is the characteristic ... [1 Related Articles]
instrument for inspecting the interior of the eye, invented in 1850 by the German physiologist Hermann von Helmholtz. The ophthalmoscope became a model for later forms of endoscopy. The device ... [4 Related Articles]
German motion-picture director whose mastery of fluid camera movement gave his films a characteristic lyrical flow. He was one of the first truly international directors, sensitive to national differences and ... [2 Related Articles]
(from the article "New Frontiers in Radio") XM Satellite Radio, based in Washington, D.C., had already set up a show for the popular duo Opie and Anthony, who had been fired from commercial radio after they broadcast ...
American pathologist who conducted important research on the causes, transmission, and diagnosis of tuberculosis and on immunization against the disease.
Estonian astronomer best known for his studies of meteors and meteorites, and whose life work was devoted to understanding the structure and evolution of the cosmos. [2 Related Articles]
(from the article "Santalales") Opiliaceae is a tropical woody family of 10 genera and about 30 species. Its leaves are usually two-ranked (distichous), and they barely show any venation on the blades. Many have ...
(from the article "arachnid") 11,000 species. Body usually hardened; 1st pair of legs have sensory organs.20 species found in North America and parts of the Mediterranean region, all of ...
(from the article "war, law of") The laws of war are to be found not only in treaties entered into by states but also in customary international law, which is found in the actual practice of ...
(from the article "China") ...reporting directly to the ruler, who coordinated all important decisions. In decision making, the emperor received additional advice from academicians and other advisers-collectively known as opinion officials-whose function was to ...
(from the article "public opinion") Opinion research developed from market research. Early market researchers picked small samples of the population and used them to obtain information on such questions as how many people read a ...
(from the article "drug") The term opioid has been adopted as a general classification of all of those agents that share chemical structures, sites, and mechanisms of action with the endogenous opioid agonists. Opioid ...
(from the article "endocrine system, human") ...but also as neuromodulators. As neuromodulators, they do not act directly as neurotransmitters but rather increase or decrease the action of neurotransmitters. Well-known examples are the opioids (e.g., enkephalins), so ...
(from the article "nervous system") ...tract and the cardiovascular system. It is not surprising, therefore, that there are multiple receptors for these substances. There may in fact be as many as eight different types of ...
(from the article "Alexander the Great") The issue came to a head at Opis (324), when Alexander's decision to send home Macedonian veterans under Craterus was interpreted as a move toward transferring the seat of power ...
any marine gastropod of the approximately 2,000 species of the subclass Opisthobranchia. These gastropods, sometimes called sea slugs and sea hares, breathe either through gills, which are located behind the ... [3 Related Articles]
(from the article "Caudata") ...it remains cartilaginous, the vertebrae are said to be amphicoelous (biconcave, or depressed on both the anterior and posterior sides), but, if it mineralizes or ossifies, the vertebrae are termed ...
(from the article "flatworm") ...rarely vertebrates; excretory vessels not open to the exterior. Most representatives require 3 hosts to complete one life cycle. Many hundreds of species.Cercaria never armed; excretory pores open on ...
(from the article "water snake") ...piscator), one of the more common species in southern Asia, grows to 1.1 metres (3.5 feet), preys upon fish and mice, and lays 17-100 eggs. In addition,
German poet and literary theorist who introduced foreign literary models into German poetry and who was a pioneer in establishing a national German literature. [2 Related Articles]
narcotic drug that is obtained from the unripe seedpods of the opium poppy (Papaver somniferum), a plant of the family Papaveraceae. (See poppy.) Opium is obtained by slightly incising the ... [27 Related Articles]
(from the article "Representative poisonous plants") ...especially for the production of narcotics; such a plant is tobacco, which was probably first used by American Indian tribes for the preparation of a narcotic drink and only later ...
in Chinese history, the traffic that developed in the 18th and 19th centuries in which Western nations, mostly Great Britain, exported opium grown in India and sold it to China. ... [3 Related Articles]
two trading wars in the mid-19th century in which Western nations gained commercial privileges in China. The first Opium War (1839-42) was between China and Britain, and the second Opium ... [15 Related Articles]
(from the article "braconid") ...pests such as beetles of the families Buprestidae and Cerambycidae. The braconid Chremilus rubiginosus attacks the granary weevil (Sitophilus granarius). In the Mediterranean region Opius concolor is a parasite of ...
(from the article "Bono") ...the trade routes of the Sahara to the terminal ports of North Africa and from there to Europe and elsewhere. Bono engaged in wars with Jakpa of Gonja and was ...
(from the article "Opole") city, capital of Opolskie wojewodztwo (province), southwestern Poland, situated on the Oder River. Opole began as the home of the Slavic Opolanie tribe; the earliest mention of ...
city, capital of Opolskie wojewodztwo (province), southwestern Poland, situated on the Oder River. Opole began as the home of the Slavic Opolanie tribe; the earliest mention of ... [1 Related Articles]
(from the article "Opole") ...southwestern Poland, situated on the Oder River. Opole began as the home of the Slavic Opolanie tribe; the earliest mention of it was in the 9th century. In 1202 it ...
wojewodztwo (province), southern Poland. It is bordered by the provinces of Wielkopolskie and Lodzkie to the north and Slaskie to the east, by the Czech Republic to ...
any of about 66 species of New World mammals constituting the family Didelphidae of the superorder Marsupialia. For ordinal relatives in American tropics, see rat opossum; for Australasian marsupials called ... [1 Related Articles]
any member of the crustacean order Mysidacea. Most of the nearly 1,000 known species live in the sea; a few live in brackish water; and fewer still live in fresh ... [2 Related Articles]
(from the article "lepidopteran") ...worldwide of very small to minute moths; antennae with broad "eyecaps" at the base; larvae mostly leaf and bark miners, a few gall makers. Approximately 100 worldwide species of ...
(from the article "Shklovsky, Viktor Borisovich") Educated at the University of St. Petersburg, Shklovsky helped found OPOYAZ, the Society for the Study of Poetic Language, in 1914. He was also connected with the Serapion Brothers, a ...
German geologist and paleontologist, who was one of the most important early stratigraphers. Oppel was a professor at Munich from 1861. In studying the Swabian Jura he discovered that paleontologic ... [1 Related Articles]
(from the article "Western sculpture") One trend of Surrealist or Fantasist sculpture of the late 1920s and the 1930s consisted of compositions made up of found objects, such as Meret Oppenheim's "Object, Fur Covered Cup" ...
South African businessman (b. Oct. 28, 1908, Kimberley, S.Af.-d. Aug. 19, 2000, Johannesburg, S.Af.), as the enormously wealthy chairman of the Anglo American Corp. (1957-82) and De Beers Consolidated Mines, ...
American theoretical physicist and science administrator, noted as director of the Los Alamos laboratory during development of the atomic bomb (1943-45) and as director of the Institute for Advanced Study, ... [7 Related Articles]
(from the article "Austria") ...want of money. This was a period of perpetual war as well as great economic investments, both entailing excessive strain on state finances. At first the government resorted to rich ...
(from the article "Western architecture") After Nicolas Pineau returned to France from Russia, he, with Gilles-Marie Oppenordt and Juste-Aurele Meissonier, who were increasingly concerned with asymmetry, created the full Rococo. Meissonier and Oppenordt should be ...
(from the article "South African literature") ...love, exile, old age, and the poetical craft. Besides writing vivid romantic poetry, Uys Krige was also a short-story writer and playwright and a fine translator from the Romance languages. ...
("OPPY"), Australian cyclist and politician (b. May 29, 1904, Rochester, Victoria, Australia--d. April 18, 1996, Melbourne, Australia), dominated long-distance cycling in the 1920s and '30s before serving in the Australian ...
(from the article "Eton College") The other students, called Oppidans, now number more than 1,200 and are housed in boardinghouses under the care of house masters. The Oppidans have traditionally come from England's wealthiest and ...
(from the article "France") With the republican regime apparently safe from outside attack, rival factions developed among the republicans. During the 1880s the labels Radical and Opportunist began to be attached to the two ...
American magazine associated with the Harlem Renaissance, published from 1923 to 1949. The editor, Charles S. Johnson, aimed to give voice to black culture, hitherto neglected by mainstream American publishing. [4 Related Articles]
(from the article "Physical Sciences") ...of whether the Martian arctic could support life, what the history of water was at the landing site, and how Martian climate was affected by polar dynamics. Meanwhile, the Mars ...
(from the article "comparative advantage") economic theory, first developed by 19th-century English economist David Ricardo, that attributed the cause and benefits of international trade to the differences among countries in the relative opportunity costs (costs ...
(from the article "primate") ...capable of grasping objects such as branches. Not all primates have similarly dextrous hands; only the catarrhines (Old World monkeys, apes, and humans) and a few of the lemurs and ...
(from the article "Bodmer, Johann Georg") ...machine to make gears; it could cut teeth of predetermined pitch, form, and depth in a metal blank. Bodmer also patented various steam-engine devices and is credited with inventing the ...
(from the article "angiosperm") ...on stems in angiosperms are alternate, opposite (paired), and whorled. In alternate-leaved plants, the leaves are single at each node and borne along the stem alternately in an ascending spiral. ...
in Pythagorean philosophy, a set of 10 pairs of contrary qualities. The earliest reference is in Aristotle, who said that it was in use among some contemporary Pythagoreans. But Aristotle ... [2 Related Articles]
in astronomy, the circumstance in which two celestial bodies appear in opposite directions in the sky. The Moon, when full, is said to be in opposition to the Sun; the ... [3 Related Articles]
(from the article "United Kingdom") ...Charles Spencer, earl of Sunderland, now serving as secretary of state. At the same time the heir apparent to the throne, George, prince of Wales, quarreled with his father and ...
(from the article "joint") ...most frequent movement is that in which the thumb swings so that it comes "face to face" with one or another of the fingers, as in grasping a needle or ...
(from the article "Uranus") ...major moons are porous and highly insulating. First, the reflectivity increases dramatically at opposition, when the observer is within 2° of the Sun as viewed from the planet. Such so-called ...
in traditional logic, a diagram exhibiting four forms of a categorical proposition (q.v.), or statement, with the same subject and predicate, together with their pairwise relationships:
(from the article "Czechoslovak region, history of") ...May not only the Czechs but also the Slovaks made statements to which Masaryk and his collaborators could point when pressing for an official recognition. The anti-Austria resolution, adopted at ...
(from the article "crime") ...by a comprehensive series of provisions. The reforms, which were supplemented by detailed codes of practice, allowed a confession to be admitted into evidence provided that it was not obtained ...
(from the article "Media and Publishing") ...satellite radio's freedom. Other high-profile media personalities also embraced satellite radio. TV talk-show host Oprah Winfrey agreed to headline a channel on XM Satellite Radio called Oprah & Friends, which ...
(from the article "Winfrey, Oprah") Winfrey has engaged in numerous philanthropic activities, including the creation of Oprah's Angel Network, which sponsors charitable initiatives worldwide. In 2007 she opened a $40-million school for disadvantaged girls in ...
private court or household created by Tsar Ivan IV the Terrible (1565) that administered those Russian lands (also known as oprichnina) that had been separated from the rest of Muscovy ... [2 Related Articles]
(from the article "coloration") Vision itself depends on a biochrome that consists of a protein, opsin, attached to a chromophore. The chromophore may be either retinal (vitamin A1), in which case the molecule is ...
(from the article "immune system") ...of complement activation. But perhaps the most important result of C3b production is that great numbers of C3b molecules are deposited on the surface of an invading pathogen in a ...
(from the article "Computers and Information Systems") Computer and printer maker Hewlett-Packard acquired two software businesses, paying $1.6 billion for Opsware, whose software automated data-centre administration, and $214 million for Neoware, which made software for centralizing the ...
(from the article "patristic literature") ...asunder by Donatism, the heretical movement that rejected the efficacy of sacraments administered by priests who had denied their faith under persecution, came the measured anti-Donatist polemic of Optatus of ...
(from the article "Computers and Information Systems") Meanwhile, chip manufacturers Advanced Micro Devices (AMD) and Intel continued their competition to put the most processors on a single chip. AMD released its latest Opteron chips-for computer servers-which each ...
degeneration of the optic nerve (the second cranial nerve) due to direct or indirect damage to a particular type of retinal cell, called ganglion cells, whose axonal projections collectively make ...
(from the article "double refraction") ...ray is seen to split into the ordinary ray CO and the extraordinary ray CE upon entering the crystal face at C. If the incident ray enters the crystal along ...
(from the article "eye, human") ...The fibres from the nasal halves of each retina cross to the opposite side of the brain, while those from the temporal halves remain uncrossed. This partial decussation is called ...
(from the article "animal development") ...which later serves as the pathway for the optic nerve. The optic vesicles extend laterally until they reach the skin, whereupon the outer surface caves in so that the vesicle ...
(from the article "eye, human") ...orbit is made up of parts of the maxilla, zygomatic, and palatine bones, while the roof is made up of the orbital plate of the frontal bone and, behind this, ...
(from the article "endocrine system") ...hormone (a hormone that has the gonads as its target organ) is stored in a typical neurohemal organ until its release is stimulated. For example, phototropic information detected by the ...
(from the article "nervous system") ...portion of the brain stem. Sensory and motor nuclei for cranial nerves extend from the hindbrain to the midbrain. The roof of the midbrain, or tectum, developed as the primary ...
second cranial nerve, which carries sensory nerve impulses from the more than one million ganglion cells of the retina toward the visual centres in the brain. The vast majority of ... [9 Related Articles]
inflammation of the optic nerve (the second cranial nerve). The inflammation causes a fairly rapid loss of vision in the affected eye, a new blind spot (a scotoma, usually in ... [2 Related Articles]
(from the article "nervous system, human") ...the optic foramen, and they join to form the optic chiasm. At the chiasm, fibres from the nasal halves of each retina cross, while those from the temporal halves remain ...
(from the article "animal development") As has been pointed out, the rudiments of the eyes develop from optic vesicles, each of which remains connected to the brain by an eye stalk, which later serves as ...
the ability of a substance to rotate the plane of polarization of a beam of light that is passed through it. (In plane-polarized light, the vibrations of the electric field ... [4 Related Articles]
(from the article "laser") ...is a laser oscillator. Oscillation determines many laser properties, and it means that the device generates light internally. Without mirrors and a resonant cavity, a laser would just be an ...
the straight line passing through the geometrical centre of a lens and joining the two centres of curvature of its surfaces. Sometimes the optical axis of a lens is called ... [2 Related Articles]
(from the article "textile") Optical brightening, or optical bleaches, are finishes giving the effect of great whiteness and brightness because of the way in which they reflect light. These compounds contain fluorescent colourless dyes, ...
