| | - Osmanabad
- town, southeastern Maharashtra state, western India, located north of Solapur. Part of the ancient Yadava Hindu kingdom, it fell to the Bahmani and Bijapur sultanates in the 14th and 16th centuries and was later incorporated into the territories of the nizams of Hyderabad. It became a part of the Indian ...
- Osmena, Sergio
- Filipino statesman, founder of the Nationalist Party (Partido Nacionalista) and president of the Philippines from 1944 to 1946.
- osmium
- chemical element, one of the platinum metals of Groups 8-10 (VIIIb), Periods 5 and 6, of the periodic table and the densest naturally occurring element. A gray-white metal, osmium is very hard, brittle, and difficult to work, even at high temperatures. Of the platinum metals it has the highest melting ...
- Osmond, Gilbert
- fictional character, an expatriate American who marries Isabel Archer in The Portrait of a Lady (1881) by Henry James.
- osmoregulation
- in biology, maintenance by an organism of an internal balance between water and dissolved materials regardless of environmental conditions. In many marine organisms osmosis (the passage of solvent through a semipermeable membrane) occurs without any need for regulatory mechanisms because the cells have the same osmotic pressure as the sea. ...
- osmosis
- the spontaneous passage or diffusion of water or other solvents through a semipermeable membrane (one that blocks the passage of dissolved substances-i.e., solutes). The process, important in biology, was first thoroughly studied in 1877 by a German plant physiologist, Wilhelm Pfeffer. Earlier workers had made less accurate studies of leaky ...
- Osmund Of Salisbury, Saint
- Norman priest, who was chancellor of England (c. 1072-78) and bishop of Salisbury (1078-99).
- Osmunda
- fern genus of the family Osmundaceae, with divided fronds and often growing to a height of 1.5 metres (5 feet). The matted fibrous roots of these abundant ferns are called osmunda fibre, osmundine, or orchid peat; they are broken up and used as a rooting medium for epiphytic orchids (those ...
- Osmundaceae
- the royal fern family, the only family of the fern order Osmundales. A primitive group consisting of three present-day genera of large ferns-Osmunda, Todea, and Leptopteris-the family contains about 20 species; 5 to 10 extinct genera date from the Late Permian Period (about 260 million to 251 million years ago). ...
- Osnabruck
- city, Lower Saxony Land (state), northwestern Germany. It lies on the canalized Hase River between the Teutoburg Forest (Teutoburger Wald) and the Wiehen Mountains (Wiehengebirge).
- Osorno
- city, southern Chile, lying at the junction of the Damas and Rahue rivers, 40 miles (64 km) inland from the Pacific coast. It was founded in 1553 under the name Santa Marina de Gaete, but this attempt failed. It was refounded in 1558 by Garcia Hurtado de Mendoza, who named ...
- osprey
- large, long-winged hawk, about 65 cm (26 inches) long, that lives along seacoasts and larger interior waterways, where it catches fish. It is brown above and white below, with some white on the head.
- Osroene
- ancient kingdom in northwestern Mesopotamia, located between the Euphrates and Tigris rivers and lying across the modern frontier of Turkey and Syria. Its capital was Edessa (modern Urfa, Tur.). The name of the kingdom appears to have been ultimately derived from a certain Osroes of Orhai, who founded the state ...
- Oss
- gemeente (municipality), south-central Netherlands, east-northeast of 's-Hertogenbosch and about 3 miles (5 km) south of the Maas (Meuse) River. Principal economic activities include food processing, pharmaceuticals and electronics manufacturing, and services. Mainly Roman Catholic, it was chartered in 1399. Pop. (2007 est.) 76,652.
- Ossa
- mountain massif, nomos (department) of Larissa (Modern Greek: Larisa), eastern Thessaly (Thessalia), Greece. It lies on the Gulf of Thermai (Thermaikos) and is separated on the north from the Olympus (Olympos) massif by the Vale of Tempe (Tembi). Rising from a broad, steep-sided plateau to a pyramidal peak of 6,489 ...
- Ossa, Mount
- highest peak in Tasmania, Australia, rising to 5,305 feet (1,617 m), in the central highlands. At the northern end of the rugged Ducane Range, Mount Ossa, along with several other peaks surpassing 5,000 feet, lies within Cradle Mountain-Lake St. Clair National Park. Its slopes are deeply gouged by glacial corries ...
- Osservatore Romano, L'
- daily newspaper published in Vatican City, one of the most influential papers in Italy and the de facto voice of the Holy See.
- Ossetic language
- eastern Iranian language spoken in the northern Caucasus by the Ossetes. There are two major dialects: (1) eastern, called Iron, and (2) western, called Digor. The majority of the Ossetes speak Iron, which is the basis of the literary language now written in the Cyrillic alphabet. Ossetic is the modern ...
- Ossian
- the Irish warrior-poet of the Fenian cycle of hero tales about Finn MacCumhaill (MacCool) and his war band, the Fianna Eireann. The name Ossian became known throughout Europe in 1762, when the Scottish poet James Macpherson "discovered" and published the poems of Oisin, first with the epic Fingal and the ...
- Ossianic ballads
- Irish lyric and narrative poems dealing with the legends of Finn MacCumhaill and his war band. They are named for Oisin (Ossian), the chief bard of the Fenian cycle. These poems belong to a common Scots-Irish tradition: some are found in the Scottish Highlands, others in Ireland, but their subjects ...
- Ossietzky, Carl von
- German journalist and pacifist, winner of the Nobel Prize for Peace for 1935.
- Ossining
- village in the town (township) of Ossining, Westchester county, southeastern New York, U.S., on the east bank of the Hudson River. The site was part of a land grant made in 1680 to Frederick Philipse by Charles II and known as Philipsburg Manor; Philipse purchased more land from the Wappinger ...
- Ossory
- an ancient kingdom of Ireland that won for itself a semi-independent position as a state within the kingdom of Leinster, probably in the 1st century AD. In the 9th century it was ruled by an able king, Cerball, who allied himself with the Norse invaders and figured in later centuries ...
- Ostade, Adriaen van
- painter and printmaker of the Baroque period known for his genre pictures of Dutch peasant life. He also did religious subjects, portraits, and landscapes. Van Ostade was a prolific artist, executing his small-scale works in oil, usually on wood panels. He also worked in watercolour, did spirited pen drawings, and ...
- Ostade, Isack van
- Dutch genre and landscape painter of the Baroque period, especially noted for his winter scenes and depictions of peasants and travelers at rustic inns.
- Ostaijen, Paul van
- Flemish man of letters whose avant-garde Expressionist poetry and writings on literature and art were influential in Belgium and the Netherlands.
- ostariophysan
- any of about 8,000 species of bony fishes belonging to a group that includes the majority of freshwater fishes throughout the world. Familiar representatives of this group are the minnows, suckers, carps, piranhas, electric eels, and innumerable catfishes. Humans consume huge quantities of ostariophysans for food. Some of these fishes ...
- Osteen, Joel
- American televangelist, theologian, and popular speaker and author.
- Ostend
- municipality, Flanders Region, northwestern Belgium. It lies along the North Sea and at the end of the Ghent-Brugge Canal. A fishing village (originally Oostende-ter-Streepe) since the 9th century, it was fortified in 1583 and became the last Dutch stronghold in Belgium, falling to the Spanish in 1604 after a three-year ...
- Ostend Company
- trading company that operated from the Austrian Netherlands from 1722 to 1731. Founded by the Holy Roman emperor Charles VI, it represented an attempt to cash in on the riches being won by the Dutch and English East India companies and stemmed from Charles VI's awareness of the importance of ...
- Ostend Manifesto
- (Oct. 18, 1854), communication from three U.S. diplomats to Secretary of State William L. Marcy, advocating U.S. seizure of Cuba from Spain; the incident marked the high point of the U.S. expansionist drive in the Caribbean in the 1850s. After Pierre Soule, U.S. minister to Spain, had failed in his ...
- osteoarthritis
- disorder of the joints characterized by progressive deterioration of the articular cartilage. It is the most common joint disease, affecting more than 80 percent of those who reach the age of 70. Although its suffix indicates otherwise, osteoarthritis is not characterized by excessive joint inflammation as is the case with ...
- osteoblast
- large cell responsible for the synthesis and mineralization of bone during both initial bone formation and later bone remodeling. Osteoblasts form a closely packed sheet on the surface of the bone, from which cellular processes extend through the developing bone. They arise from the differentiation of osteogenic cells in the ...
- osteochondroma
- solitary benign tumour that consists partly of cartilage and partly of bone. Osteochondromas are common and may develop spontaneously following trauma or may have a hereditary basis. No treatment is required unless the tumour interferes with function, in which case it should be surgically removed. Rarely, a solitary osteochondroma will ...
- osteochondrosis
- relatively common temporary orthopedic disorder of children in which the epiphysis (growing end) of a bone dies and then is gradually replaced over a period of years. The immediate cause of bone death is loss of blood supply, but why the latter occurs is unclear. The most common form, coxa ...
- osteoclast
- large multinucleated cell responsible for the dissolution and absorption of bone. Bone is a dynamic tissue that is continuously being broken down and restructured in response to such influences as structural stress and the body's requirement for calcium. The osteoclasts are the mediators of the continuous destruction of bone. Osteoclasts ...
- osteoclastoma
- bone tumour found predominantly at the end of long bones in the knee region, but also occurring in the wrist, arm, and pelvis. The large multinucleated cells (giant cells) found in these tumours resemble osteoclasts, for which the tumour is named. Usually seen in female adults between the ages of ...
- osteocyte
- a cell that lies within the substance of fully formed bone. It occupies a small chamber called a lacuna, which is contained in the calcified matrix of bone. Osteocytes derive from osteoblasts, or bone-forming cells, and are essentially osteoblasts surrounded by the products they secreted. Cytoplasmic processes of the osteocyte ...
- Osteodontokeratic tool industry
- assemblage of fossilized animal bones found at Taung by Raymond Arthur Dart about 200 miles (320 km) from Johannesburg, S.Af., where the first specimen of Australopithecus africanus was found, and at Makapansgat, where other specimens of A. africanus were found. Dart proposed that these fossils were tools used by A.africanus, ...
- osteogenesis imperfecta
- rare hereditary disease of connective tissue characterized by brittle bones that fracture easily. OI arises from a genetic defect that causes abnormal or reduced production of the protein collagen, a major component of connective tissue. There are four types of OI, which differ in symptoms and severity.
- osteoglossomorph
- any member of what is widely believed to be the most primitive group of bony fishes. This reputation stems from their rudimentary caudal skeleton and the lack of a set of intermuscular bones throughout the abdominal and anterior caudal regions of the body. Osteoglossomorphs are unique among fishes in that ...
- Osteolepis
- extinct genus of lobe-finned fishes from the Late Devonian; Osteolepiformes is a variation of this name that was given to a group of vertebrates that contained the closest relatives of the tetrapods. Osteolepis survived into later Devonian time. (The Devonian Period lasted from 416 million to 359 million years ago.) ...
- osteoma
- small, often solitary bone tumour found mainly on bones of the skull. Osteomas usually appear in late childhood or young adulthood; they are often asymptomatic. They do not become malignant, and treatment (by excision) is necessary only if the tumour interferes with normal functioning.
- osteomalacia
- condition in which the bones of an adult progressively soften because of inadequate mineralization of the bone. (In children the condition is called rickets.) Osteomalacia may occur after several pregnancies or in old age, resulting in increased susceptibility to fractures. Symptoms include bone pain, weakness, numbness of the extremities, and ...
- osteomyelitis
- infection of bone tissue. The condition is most commonly caused by the infectious organism Staphylococcus aureus, which reaches the bone via the bloodstream or by extension from a local injury; inflammation follows with destruction of the cancellous (porous) bone and marrow, loss of blood supply, and bone death. Living bone ...
- osteon
- the chief structural unit of compact (cortical) bone, consisting of concentric bone layers called lamellae, which surround a long hollow passageway, the Haversian canal (named for Clopton Havers, a 17th-century English physician). The Haversian canal contains small blood vessels responsible for the blood supply to osteocytes (individual bone cells). Osteons ...
- osteonecrosis
- death of bone tissue that may result from infection, as in osteomyelitis, or deprivation of blood supply, as in fracture, dislocation, Caisson disease (decompression sickness), or radiation sickness. In all cases, blood circulation in the affected area ceases, bone cells die, and the marrow cavity becomes filled with debris. Surrounding ...
- osteopathy
- health care profession that emphasizes the relationship between the musculoskeletal structure and organ function. Osteopathic physicians develop skill in recognizing and correcting structural problems through manipulative therapy and other treatments.
- osteoporosis
- disease characterized by the thinning of bones, with a consequent tendency to sustain fractures from minor stresses. Osteoporosis is the most common metabolic bone disease, and its name literally means "porous bone." The disorder is most common in postmenopausal women over age 50. It is estimated that approximately one-fourth of ...
- osteosarcoma
- most common bone cancer, primarily affecting the long bones, particularly those in the knee, hip, or shoulder regions. The cause of osteosarcoma is unknown, but genetic factors and radiation therapy may be involved in its development. Osteosarcoma occurs more often in males than in females; most affected individuals are under ...
- Osterdalen
- narrow valley, Hedmark fylke (county), southeastern Norway. It extends in a general north-south direction from the eastern flanks of the Dovre Mountains and is approximately 75 miles (120 km) long. The Glomma (Glama), Norway's longest river, flows through the valley. Lumbering, agriculture (grains and hay), and livestock raising are principal ...
|
|