• Orsino (fictional character)

    Twelfth Night: …enters the service of Duke Orsino, who thinks he is in love with the lady Olivia. Orsino sends Viola-Cesario to plead his cause to Olivia, who promptly falls in love with the messenger. Viola, meanwhile, is in love with Orsino, and, when her twin, Sebastian, is rediscovered, many comic situations…

  • Orsk (Russia)

    Orsk, city, Orenburg oblast (region), western Russia. It lies about 150 miles (240 km) south of Magnitogorsk at the confluence of the Ural and Or rivers. It was founded in 1735 as the fortress of Orenburg, which was moved downriver in 1743. Orsk is now a major industrial centre, with a large oil

  • Orso (doge of Venice)

    Venice: Origin of the city: …elected doge, or duke, was Orso, chosen in an anti-Byzantine military declaration in 727, but he was succeeded by Byzantine officials until about 751, when the exarchate of Ravenna came to an end. There followed decades of internal political strife among various settlements vying for supremacy and between pro- and…

  • Orsona (Spain)

    Osuna, town, Sevilla provincia (province), in the comunidad autónoma (autonomous community) of Andalusia, southern Spain. Osuna lies at the foot of a hill at the edge of an extensive plain, east-southeast of Sevilla city. Of Iberian origin, the town became the Roman Urso and supported Pompey

  • Ørsted, Hans Christian (Danish physicist and chemist)

    Hans Christian Ørsted was a Danish physicist and chemist who discovered that electric current in a wire can deflect a magnetized compass needle, a phenomenon the importance of which was rapidly recognized and which inspired the development of electromagnetic theory. In 1806 Ørsted became a

  • Orsza, Battle of (Poland[1514])

    Poland: Foreign affairs: …only a major victory at Orsza in 1514 averted a catastrophe. The victory allowed Sigismund I to detach the Habsburgs from Moscow through the Vienna accords of 1515. Providing for dynastic marriages, the accords opened the way for Habsburg succession in Bohemia and Hungary should the Jagiellonians die out. Eleven…

  • Országh, Pavol (Slovak poet)

    Hviezdoslav was one of the most powerful and versatile of Slovak poets. Hviezdoslav was a lawyer until he became able to devote himself to literature. He originally wrote in Hungarian and was a Hungarian patriot, but in the 1860s he switched both activities to Slovak. By the time of his death the

  • ORT (Russian company)

    Boris Berezovsky: …state airline, Aeroflot, and of Russian Public Television (ORT), Russia’s main television channel.

  • ORT (medicine)

    oral rehydration therapy (ORT), treatment consisting of a salt-and-sugar-based solution taken orally to treat dehydration from diarrhea. The salts can be prepackaged and typically include a combination of sodium, glucose, potassium, and citrate to be mixed with clean water. Oral rehydration therapy

  • ört (Finno-Ugric religion)

    ört, in Finno-Ugric religion, a shape or shadow that corresponds to the individual soul. The Mari people believe that the ört is “free”—i.e., it can leave the body and wander about during dreams or trance states. The concept of a free soul is common to all Finno-Ugric peoples. The Votyak urt and

  • Orta, Lago d’ (lake, Italy)

    Lake Orta, lake in Novara and Verbano-Cusio-Ossola provincie, Piemonte (Piedmont) regione, northwestern Italy, just west of Lake Maggiore, from which it is divided by Mount Mottarone. About 8 miles (13 km) long and 0.75 mile (1.2 km) wide, it has an area of 7 square miles (18 square km). Its

  • Orta, Lake (lake, Italy)

    Lake Orta, lake in Novara and Verbano-Cusio-Ossola provincie, Piemonte (Piedmont) regione, northwestern Italy, just west of Lake Maggiore, from which it is divided by Mount Mottarone. About 8 miles (13 km) long and 0.75 mile (1.2 km) wide, it has an area of 7 square miles (18 square km). Its

  • Ortalis (bird)

    chachalaca, any of several small birds of the curassow family. See

  • Ortalis vetula (bird)

    curassow: Typical is the plain chachalaca (Ortalis vetula), a 50-cm species, ranging from the Texas border to Nicaragua. Weighing about 0.5 kg (1 pound), it is brownish with a long, green-glossed, white-tipped tail. At dawn and sundown, flocks call together from the treetops with a regular, almost metronomic beat.

  • ortaoyunu (Turkish theater)

    Islamic arts: Ortaoyunu: The ortaoyunu (middle show) was the first type of genuine theatre the Turks, and possibly other Muslim peoples, ever had. The Ottoman sultans provided subsidies for ortaoyunu companies of actors, who consequently became generally accepted; also some were retained by the princes of the…

  • Ortega Gaona, Amancio (Spanish fashion executive)

    Amancio Ortega is a Spanish fashion executive and founding chairman (1985) of the Spanish clothing merchandiser Inditex (Industria de Diseño Textil, SA), which included the Zara chain store. As a youth in A Coruña, in northwestern Spain, Ortega gained an entry into the garment business by working

  • Ortega Saavedra, José Daniel (president of Nicaragua)

    Daniel Ortega is a Nicaraguan guerrilla leader, member of the Sandinista junta that took power in 1979, and the elected president of Nicaragua (1984–90, 2007– ). Son of a veteran of the peasant army of César Augusto Sandino, Ortega moved with his family to Managua in the mid-1950s. He briefly

  • Ortega y Gasset, José (Spanish philosopher)

    José Ortega y Gasset was a philosopher and humanist who greatly influenced the cultural and literary renaissance of Spain in the 20th century. Ortega y Gasset studied at Madrid University (1898–1904) and in Germany (1904–08) and was influenced by the neo-Kantian philosophical school at Marburg. As

  • Ortega, Amancio (Spanish fashion executive)

    Amancio Ortega is a Spanish fashion executive and founding chairman (1985) of the Spanish clothing merchandiser Inditex (Industria de Diseño Textil, SA), which included the Zara chain store. As a youth in A Coruña, in northwestern Spain, Ortega gained an entry into the garment business by working

  • Ortega, Daniel (president of Nicaragua)

    Daniel Ortega is a Nicaraguan guerrilla leader, member of the Sandinista junta that took power in 1979, and the elected president of Nicaragua (1984–90, 2007– ). Son of a veteran of the peasant army of César Augusto Sandino, Ortega moved with his family to Managua in the mid-1950s. He briefly

  • Ortega, Domingo (Spanish bullfighter)

    Domingo Ortega was a Spanish matador noted for his daring and for his contribution to the literature of bullfighting. Ortega came from a family of labourers and began bullfighting in 1928. He first appeared as a matador on March 8, 1931, and continued to fight for more than 20 years. He was one of

  • Ortega, Jenna (American actress)

    Jenna Ortega is an American actress who began her career as a child actor, starring in such Disney Channel shows as Stuck in the Middle (2016–18), and later went on to gain international fame with the lead role in the hit Netflix series Wednesday (2022– ). Ortega often discussed her Mexican and

  • Ortega, Jenna Marie (American actress)

    Jenna Ortega is an American actress who began her career as a child actor, starring in such Disney Channel shows as Stuck in the Middle (2016–18), and later went on to gain international fame with the lead role in the hit Netflix series Wednesday (2022– ). Ortega often discussed her Mexican and

  • Ortega, José Gómez (Spanish bullfighter)

    Joselito was a Spanish matador, considered one of the greatest of all time. With Juan Belmonte he revolutionized the art of bullfighting in the second decade of the 20th century. Joselito came from a family of bullfighters and was the youngest man ever to receive the title of matador (October

  • Orteig Prize (aviation prize)

    SpaceShipOne: Inspired by the Orteig Prize won by Charles Lindbergh for his solo flight across the Atlantic in 1927, which was sponsored by American hotel owner Raymond Orteig, the $10 million Ansari X Prize was sponsored by Iranian-born American entrepreneurs Anousheh and Amir Ansari and was offered to the…

  • Orteig, Raymond B. (American hotel owner)

    SpaceShipOne: …sponsored by American hotel owner Raymond Orteig, the $10 million Ansari X Prize was sponsored by Iranian-born American entrepreneurs Anousheh and Amir Ansari and was offered to the first private enterprise that successfully completed two piloted flights with the equivalent weight of two passengers to the boundary of space in…

  • Ortelius, Abraham (Flemish cartographer)

    Abraham Ortelius was a Flemish cartographer and dealer in maps, books, and antiquities, who published the first modern atlas, Theatrum orbis terrarum (1570; “Theatre of the World”). Trained as an engraver, Ortelius about 1554 set up his book and antiquary business. About 1560, under the influence

  • Ortels, Abraham (Flemish cartographer)

    Abraham Ortelius was a Flemish cartographer and dealer in maps, books, and antiquities, who published the first modern atlas, Theatrum orbis terrarum (1570; “Theatre of the World”). Trained as an engraver, Ortelius about 1554 set up his book and antiquary business. About 1560, under the influence

  • Orten, Jiří (Czech poet)

    Czech Republic: Literature of the Czech Republic: …brief life and work of Jiří Orten is an outstanding example of his tragic generation.

  • Orthagorid tyranny (ancient Greek history)

    ancient Greek civilization: The early tyrannies: At Sicyon the Orthagorid tyranny, whose most splendid member was the early 6th-century Cleisthenes, may have exploited the anti-Dorianism already noted as a permanent constituent of the mentality of some Greeks; but since the relevant action—a renaming of tribes—falls in the time of Cleisthenes himself, it is no…

  • orthicon (electronics)

    television: Electron tubes: …improved tubes such as the Orthicon, the Image Orthicon, and the Vidicon. The operation of the camera tube is based on the photoconductive properties of certain materials and on electron beam scanning. These principles can be illustrated by a description of the Vidicon, one of the most enduring and versatile…

  • Orthida (fossil lamp shell order)

    lamp shells: Annotated classification: Order Orthida Usually biconvex, wide-hinged, with interareas in both valves; teeth deltidiodont (leave a growth path along margin of pedicle opening); hinge structures consist of brachiophores (supporting structures), shell substance punctate or impunctate—i.e., with or without pits; more than 200 genera; Early Cambrian through Permian. Order…

  • ortho-carborane (chemical compound)

    carborane: Reactions and synthesis of carboranes: …isomers are often simply called ortho-, meta-, and para-carborane.

  • ortho-cousin (kinship)

    parallel cousin, the child of a paternal uncle (father’s brother) or a maternal aunt (mother’s sister). Parallel cousins are thus the children of two brothers or two sisters. The children of a father’s brother are patrilateral parallel cousins; the children of a mother’s sister are matrilateral

  • ortho-cresol (chemical compound)

    cresol: …formula but having different structures: ortho- (o-) cresol, meta- (m-) cresol, and para- (p-) cresol.

  • ortho-hydrogen (chemistry)

    hydrogen: Ortho-hydrogen and para-hydrogen: Two types of molecular hydrogen (ortho and para) are known. These differ in the magnetic interactions of the protons due to the spinning motions of the protons. In ortho-hydrogen, the spins of both protons are aligned in the same direction—that is, they…

  • ortho-hydroxybenzoic acid (chemical compound)

    salicylic acid, a white, crystalline solid that is used chiefly in the preparation of aspirin and other pharmaceutical products. The free acid occurs naturally in small amounts in many plants, particularly the various species of Spiraea. The methyl ester also occurs widely in nature; it is the

  • ortho-sulfobenzoic acid imide (chemical compound)

    saccharin, organic compound employed as a non-nutritive sweetening agent. It occurs as insoluble saccharin or in the form of various salts, primarily sodium and calcium. Saccharin has about 200–700 times the sweetening power of granulated sugar and has a slightly bitter and metallic aftertaste. For

  • ortho-xylene (isomer)

    chemical industry: Xylene: Ortho-xylene is used mostly to produce phthalic anhydride, an important intermediate that leads principally to various coatings and plastics. The least valued of the isomers is meta-xylene, but it has uses in the manufacture of coatings and plastics. Para-xylene leads to polyesters, which reach the…

  • orthoboric acid (chemical compound)

    boric acid, (H3BO3), white crystalline, oxygen-bearing acid of boron found in certain minerals and volcanic waters or hot springs (see

  • orthobreccia (geology)

    sedimentary rock: Clast-supported conglomerates: Clast-supported conglomerates (and orthobreccias) are deposited by highly turbulent water. For example, beach deposits commonly contain lenses and bands of oligomictic orthoconglomerate, composed mainly (95 percent or more) of stable, resistant, coarse clasts of vein quartz, quartzite, quartz sandstone, and chert. Such deposits are typically generated in the…

  • Orthobunyavirus (virus genus)

    bunyavirus: …bunyavirus family contains five genera: Orthobunyavirus, Phlebovirus, Nairovirus, Tospovirus, and Hantavirus. Most of these viruses are transmitted by arthropods (e.g., ticks, mosquitoes, and sand flies) and cause

  • Orthoceras (fossil mollusk genus)

    cephalopod: Evolution and paleontology: The primitive elongate shell of Orthoceras became unmanageable and coiling resulted, as in the Gastropoda.

  • orthochemical rock (geology)

    sedimentary rock: …rocks and (2) allochemical and orthochemical sedimentary rocks.

  • orthochromatic film (photography)

    motion-picture technology: Introduction of color: …filter to a bi-pack of orthochromatic and panchromatic films with their emulsion surfaces in contact. The orthochromatic film became the blue record. As it was insensitive to red light, the orthochromatic film passed the red rays to the panchromatic film. A 1938 improvement added red-orange dye to the orthochromatic film…

  • orthoclase (mineral)

    orthoclase, common alkali feldspar mineral, a potassium aluminosilicate (KAlSi3O8); it usually occurs as variously coloured, frequently twinned crystals in granite. Orthoclase is used in the manufacture of glass and ceramics; occasionally, transparent crystals are cut as gems. Orthoclase is

  • orthoconglomerate (geology)

    sedimentary rock: Epiclastic conglomerates and breccias: …into two specific categories: (1) clast-supported conglomerates (and breccias) and (2) matrix-supported conglomerates.

  • orthodontics (dentistry)

    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 unacceptable contact of opposing dentition, which may be caused by

  • orthodox (religious doctrine)

    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 Christianity by the Greek Fathers. Because almost every Christian group believes that it holds

  • Orthodox Catholic Church (Christianity)

    Eastern Orthodoxy, one of the three major doctrinal and jurisdictional groups of Christianity. It is characterized by its continuity with the apostolic church, its liturgy, and its territorial churches. Its adherents live mainly in the Balkans, the Middle East, and former Soviet countries. Eastern

  • Orthodox Church (Christianity)

    Eastern Orthodoxy, one of the three major doctrinal and jurisdictional groups of Christianity. It is characterized by its continuity with the apostolic church, its liturgy, and its territorial churches. Its adherents live mainly in the Balkans, the Middle East, and former Soviet countries. Eastern

  • Orthodox Church in America

    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. Established in 1794 in Alaska, then Russian territory, the Russian Orthodox mission

  • Orthodox Church of Albania

    Albania: From Illyria to Albania: Iconoclastic Controversy, detached the Albanian church from the Roman pope and placed it under the patriarch of Constantinople. When the Christian church split in 1054 between the East and Rome, southern Albania retained its tie to Constantinople while northern Albania reverted to the jurisdiction of Rome. This split in…

  • Orthodox Church of Constantinople

    Nestorius: …was an 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 major Christian heresies. A few small Nestorian churches still exist.

  • Orthodox Church of Czechoslovakia

    Orthodox Church of Czechoslovakia, autocephalous, or ecclesiastically independent, member of the Eastern Orthodox communion, created in 1951 by the patriarchate of Moscow. There was no unified Orthodox organization in Czechoslovakia before World War II. In the 19th century some Czechs formed an

  • Orthodox Church of Finland

    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 Soviet Union in 1940, which was Christianized by Russian monks in the 12th

  • Orthodox Church of Greece (national church)

    Church of Greece, the established church of Greece, and one of the most important autocephalous, or ecclesiastically independent, churches of the Eastern Orthodox communion. During the Byzantine Empire and the subsequent Turkish occupation of Greece, the Christian church in Greece was under the

  • Orthodox Church of Poland (Eastern Orthodoxy)

    Orthodox Church of Poland, ecclesiastically independent member of the Eastern Orthodox communion, established in 1924 to accommodate the four million Orthodox Christians residing in the vast Ukrainian and Byelorussian territories acquired by Poland after World War I. As the new political situation

  • Orthodox Church of Romania

    Romanian Orthodox Church, the largest autocephalous, or ecclesiastically independent, Eastern Orthodox church in the Balkans today. It is the church to which the majority of Romanians belong, and in the late 20th century it had a membership of more than 16 million. Christianity first reached Dacia

  • Orthodox Church of Ukraine

    Orthodox Church of Ukraine, autocephalous, or ecclesiastically independent, member of the Eastern Orthodox communion, whose split from the Russian Orthodox Church was affirmed by the Ecumenical Patriarchate of Constantinople in 2019. The predominant religion in Ukraine, practiced by almost half the

  • Orthodox Confession of the Faith, The (Eastern Orthodoxy)

    catechism: …the Orthodox, Peter Mogila composed The Orthodox Confession of Faith. It was approved at a provincial synod in 1640 and standardized by the synod of Jerusalem in 1672. By order of the Russian tsar Peter I the Great, a smaller Orthodox catechism was prepared in 1723.

  • Orthodox Dogmatic Theology (work by Macarius Bulgakov)

    Macarius Bulgakov: …among Macarius’ extensive works is Orthodox Dogmatic Theology, 6 vol. (1847–53). Condensed to three volumes and bound as a single handbook in 1868, the work became a popular student manual. Macarius was influenced by the positive, or historical, theology of Giovanni Perrone and other 19th-century Roman Catholic writers. While closely…

  • Orthodox Jewish Congregations of America, Union of (North American religious federation)

    Union of Orthodox Jewish Congregations of America, official federation of Jewish Orthodox synagogues in the United States and Canada; its counterpart organization for rabbis is the Rabbinical Council of America. The union was established in New York City in 1898 to foster Orthodox beliefs and

  • Orthodox Judaism

    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 sacred Jewish writings contain not only eternally valid moral principles but also

  • orthodox masters (Chinese artists)

    Six Masters of the early Qing period, Group of major Chinese artists who worked in the 17th and early 18th centuries (Qing dynasty). Also known as “orthodox masters,” they continued the tradition of the scholar-painter, following the injunctions of the artist-critic Dong Qichang late in the Ming

  • Orthodox Presbyterian Church (Christianity)

    John Gresham Machen: …of America, which became the Orthodox Presbyterian Church in 1939. Machen was a major theological voice in support of conservative Christianity.

  • Orthodox Rabbis of the United States and Canada, Union of (Orthodox Jewish organization)

    Union of Orthodox Rabbis of the United States and Canada, Orthodox Jewish organization founded in New York City in 1902 to foster traditional Orthodox practices, including strict observance of the sabbath and the dietary laws (kashruth). The union also hopes to insure that Orthodox Jews within

  • Orthodox, Baptistery of the (baptistery, Ravenna, Italy)

    mosaic: Early Christian mosaics: …his fellow apostles in the Baptistery of the Orthodox, Ravenna (c. 450). But the designer’s mastery and sophistication are nowhere more overwhelmingly illustrated than in the glowing interior of the so-called Mausoleum of Galla Placidia (c. 450) at Ravenna, with its blue star-filled mosaic dome, and in the decoration of…

  • Orthodoxy, Autocracy, and Nationality (Russian slogan)

    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 (reigned 1825–55) and remained the guiding principle behind government

  • Orthodoxy, Feast of (Eastern Orthodoxy)

    Feast of Orthodoxy, 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 churches (843) and the end of the long iconoclastic controversy. Fear of idolatry had led to an

  • Orthoepia Anglicana (work by Daines)

    punctuation: Punctuation in English since 1600: … (1589), and Simon Daines, in Orthoepia Anglicana (1640), specified a pause of one unit for a comma, of two units for a semicolon, and of three for a colon, they were no doubt trying to bring some sort of order into a basically confused and unsatisfactory situation. The punctuation of…

  • orthoepy (language)

    pronunciation: Orthoepy, correct pronunciation, is parallel to orthography, correct spelling. “How do you pronounce [spell] that word?” is either a request for the correct pronunciation (spelling) by one who is unsure or a probing for evidence that the respondent does not pronounce (spell) correctly or speaks…

  • orthoferrosilite (pyroxene)

    pyroxene: Chemical composition: …MgSiO3 (enstatite), and FeSiO3 (ferrosilite). Since no true pyroxenes exist with calcium contents greater than that of the diopside-hedenbergite join, the part of this system below this join is known as the pyroxene quadrilateral. Ferrous iron and magnesium substitute freely since they have similar ionic sizes and identical charges.…

  • orthogenesis (biology)

    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 in an orthogenetic group appear to have little if

  • Orthognatha (spider suborder)

    spider: Annotated classification: Suborder Orthognatha (mygalomorph spiders) Most species large and long-lived in warm climates. 2 pairs of book lungs; heart with 4, rarely 3, ostia; bulb of male pedipalps simple; female without epigynum; 13th through 18th ganglia lost, others fused. Family Theraphosidae (hairy mygalomorphs, tarantulas, baboon

  • orthogneiss (geology)

    gneiss: Orthogneiss is formed by the metamorphism of igneous rocks; paragneiss results from the metamorphism of sedimentary rocks. Pencil gneiss contains rod-shaped individual minerals or segregations of minerals, and augen gneiss contains stubby lenses of feldspar and quartz having the appearance of eyes scattered through the…

  • orthogonal array (mathematics)

    combinatorics: Orthogonal arrays and the packing problem: 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 s levels if each t × N submatrix of…

  • orthogonal grid system (urban planning)

    urban planning: Early history: cities, however, was the rigid grid plan of Philadelphia, designed by William Penn (1682). This plan traveled west with the pioneers, since it was the simplest method of dividing surveyed territory. Although it took no cognizance of topography, it facilitated the development of land markets by establishing standard-sized lots that…

  • orthogonal Latin squares

    combinatorics: Orthogonal Latin squares: …squares are said to be orthogonal if, when superposed, any symbol of the first square occurs exactly once with each symbol of the second square. Two orthogonal Latin squares of order 4 are exhibited in Figure 2.

  • orthogonal projection (engineering)

    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 drawing. For example, an orthographic projection of a house typically

  • orthogonal trajectory (mathematics)

    orthogonal trajectory, family of curves that intersect another family of curves at right angles (orthogonal; see figure). Such families of mutually orthogonal curves occur in such branches of physics as electrostatics, in which the lines of force and the lines of constant potential are orthogonal;

  • orthogonality (mathematics)

    orthogonality, In mathematics, a property synonymous with perpendicularity when applied to vectors but applicable more generally to functions. Two elements of an inner product space are orthogonal when their inner product—for vectors, the dot product (see vector operations); for functions, the

  • orthograde posture (physiology)

    primate: Bipedalism: All primates sit upright. Many stand upright without supporting their body weight by their arms, and some, especially the apes, actually walk upright for short periods. The view that the possession of uprightness is a solely human attribute is untenable; humans are merely the one species of the…

  • Orthographiae ratio (work by Manutius)

    punctuation: Punctuation in Greek and Latin to 1600: …a similar system in his Orthographiae ratio (“System of Orthography”); it included, under different names, the modern comma, semicolon, colon, and full point, or period. Most importantly, the younger Aldo stated plainly for the first time the view that clarification of syntax is the main object of punctuation. By the…

  • orthographic projection (engineering)

    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 drawing. For example, an orthographic projection of a house typically

  • orthography (linguistics)

    Baltic languages: Orthography: 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 falling tones and a tilde for rising tones; the grave accent is used for…

  • Orthohepadnavirus (virus genus)

    hepadnavirus: …two recognized genera of hepadnavirus: Orthohepadnavirus and Avihepadnavirus. The former includes hepatitis B viruses that have been isolated from mammals, including humans, woodchucks, ground squirrels, Arctic squirrels, and woolly monkeys. The second genus, Avihepadnavirus, consists of hepatitis B viruses that infect birds, including ducks, herons, cranes, and storks. There are…

  • orthokinesis (biology)

    stereotyped response: Reflex-like activities: …from rest to movement (orthokinesis) or of frequency or amount of turning of the whole animal (klinokinesis), the speed of frequency depending on the intensity of stimulation. Examples of orthokinesis are seen in lampreys, which are more active in high intensities of light, and in cockroaches, which are more…

  • orthometric correction (surveying)

    surveying: Triangulation: To correct these distortions, orthometric corrections must be applied to long lines of levels at high altitudes that have a north–south trend.

  • Orthomyxoviridae (virus group)

    orthomyxovirus, any virus belonging to the family Orthomyxoviridae. Orthomyxoviruses have enveloped virions (virus particles) that measure between 80 and 120 nm (1 nm = 10−9 metre) in diameter. The nucleocapsid, which consists of a protein shell, or capsid, and contains the viral nucleic acids, has

  • orthomyxovirus (virus group)

    orthomyxovirus, any virus belonging to the family Orthomyxoviridae. Orthomyxoviruses have enveloped virions (virus particles) that measure between 80 and 120 nm (1 nm = 10−9 metre) in diameter. The nucleocapsid, which consists of a protein shell, or capsid, and contains the viral nucleic acids, has

  • orthonectid (animal)

    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 as intermediate between protozoans (single-celled animals) and metazoans

  • Orthonectida (animal)

    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 as intermediate between protozoans (single-celled animals) and metazoans

  • Orthonotia (mollusk subclass)

    bivalve: Evolution and paleontology: The subclass Orthonotia also arose in the Ordovician Period and are the probable ancestors of the deep-burrowing razor shells (Solenoidea). The origins of the subclass Anomalodesmata are less clear, but they too arose in the Ordovician Period and may have links to the order Myoida, which presently…

  • Orthonychidae (bird family)

    passeriform: Annotated classification: Family Orthonychidae (logrunners and chowchillas) Medium-sized terrestrial birds, 17–28 cm (about 7–11 inches). Once linked to babblers of Asia and thought to be part of whipbird family (Eupetidae) but now known to be part of the endemic Australasian avifauna. Females build domed stick nests with side…

  • Orthonychinae (bird)

    rail-babbler, any member of the songbird subfamily Orthonychinae (order Passeriformes), placed by some authorities with other babblers in the family Timaliidae and by others near the subfamily Timaliinae when the latter are placed in the Muscicapidae. It is also the particular name of species that

  • orthopedic device

    materials science: Orthopedic devices: 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 aid recovery of bone fractures has become routine, with the number of annual procedures…

  • orthopedic surgery (medicine)

    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. The term orthopedics was introduced in 1741 by French physician Nicolas Andry de Bois-Regard in his

  • orthopedics (medicine)

    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. The term orthopedics was introduced in 1741 by French physician Nicolas Andry de Bois-Regard in his

  • orthophosphoric acid (chemical compound)

    phosphoric acid, (H3PO4), the most important oxygen acid of phosphorus, used to make phosphate salts for fertilizers. It is also used in dental cements, in the preparation of albumin derivatives, and in the sugar and textile industries. It serves as an acidic, fruitlike flavouring in food products.