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  • arthritis mutilans (disease)

    arthritis: Spondyloarthropathies: …though certain forms, such as arthritis mutilans, can be quite severe. Occasionally the onset of symptoms associated with psoriatic arthritis is acute, though more often it is insidious, initially presenting as oligoarthritis with enthesitis. Over time, arthritis begins to affect multiple joints (polyarthritis), especially the hands and feet, resulting in…

  • Arthrobotrys (fungal genus)

    fungus: Predation: …rings of some species of Arthrobotrys, Dactylella, and Dactylaria—soil-inhabiting fungi easily grown under laboratory conditions. In the presence of nematodes, the mycelium produces large numbers of rings through which the average nematode is barely able to pass. When a nematode rubs the inner wall of a ring, which usually consists…

  • arthrodesis (medicine)

    joint: Types of joints: Such fusion is called arthrodesis. All permanent and some transient joints permit movement. Movement of the latter may be temporary, as with the roof bones of an infant’s skull during birth, or long-term, as with the joints of the base of the skull during postnatal development.

  • arthrodial joint (anatomy)

    Plane joint, in anatomy, type of structure in the body formed between two bones in which the articular, or free, surfaces of the bones are flat or nearly flat, enabling the bones to slide over each other. Because the articular surfaces of the bones are free and move in a sliding motion, the plane

  • arthrodire (placoderm)

    Arthrodire, any member of an order of extinct, armoured, jawed fishes (placoderms) found in Devonian freshwater and marine deposits. (The Devonian period lasted from 416 million to 359 million years ago.) Early arthrodires, such as the genus Arctolepis, were well-armoured fishes with flattened

  • Arthrodiriformes (placoderm)

    Arthrodire, any member of an order of extinct, armoured, jawed fishes (placoderms) found in Devonian freshwater and marine deposits. (The Devonian period lasted from 416 million to 359 million years ago.) Early arthrodires, such as the genus Arctolepis, were well-armoured fishes with flattened

  • arthrogryposis (pathology)

    joint disease: Congenital and hereditary abnormalities: In arthrogryposis multiplex congenita (multiple congenital crooked joints), many joints are deformed at birth, particularly the hip. The deformities are the consequence of muscle weakness that in turn sometimes results from spinal cord disease. Clubfoot (talipes equinovarus) is a congenital deformity in which the foot is…

  • arthrogryposis multiplex congenita (pathology)

    joint disease: Congenital and hereditary abnormalities: In arthrogryposis multiplex congenita (multiple congenital crooked joints), many joints are deformed at birth, particularly the hip. The deformities are the consequence of muscle weakness that in turn sometimes results from spinal cord disease. Clubfoot (talipes equinovarus) is a congenital deformity in which the foot is…

  • Arthroleptidae (amphibian family)

    Anura: Annotated classification: Family Arthroleptidae No fossil record; 8 presacral vertebrae; vertebral column procoelous with Presacral VIII (biconcave); aquatic larvae or direct development; 7 genera, 74 species; adult size 1.5–13 cm (0.5–5 inches); 2 subfamilies: Arthroleptinae (Africa) and Astylosterninae (Africa). Family Dendrobatidae

  • Arthroleptinae (amphibian subfamily)

    Anura: Annotated classification: 5–5 inches); 2 subfamilies: Arthroleptinae (Africa) and Astylosterninae (Africa). Family Dendrobatidae (poison frogs) No fossil record; 8 presacral vertebrae; pectoral girdle completely firmisternal; intercalary cartilages absent; omosternum present; Bidder’s organ absent; maxillary teeth present or absent. Larvae carried on backs of adults;

  • arthropathy (pathology)

    Joint disease, any of the diseases or injuries that affect human joints. Arthritis is no doubt the best-known joint disease, but there are also many others. Diseases of the joints may be variously short-lived or exceedingly chronic, agonizingly painful or merely nagging and uncomfortable; they may

  • arthroplasty (surgery)

    bone disease: Therapeutic and corrective measures: Arthroplasty, aimed at restoration of normal joint motion, is usually performed because of pain and restricted motion—for example, in rheumatoid arthritis of the elbow or the hip—but occasionally to restrict mobility—for example, in recurrent dislocation of the shoulder. Structural support and smooth gliding surfaces can…

  • Arthropleura (fossil invertebrate)

    millipede: The extinct invertebrate Arthropleura, a relative of centipedes and millipedes, lived during the Carboniferous Period (359.2 million to 299 million years ago) and ranks among the largest insects ever described; estimates from fossil armour segments suggest that the species could have grown to more than 2 metres (6.6…

  • arthropod (animal phylum)

    Arthropod, any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes. About 84 percent of all known species of animals are members of this phylum. Arthropods are

  • arthropod-borne virus (virus)

    Arbovirus, acronym derived from arthropod-borne virus, any of a group of RNA viruses that develop in arthropods (chiefly blood-sucking mosquitoes and ticks), in which they cause no apparent harm, and are subsequently transmitted by bites to vertebrate hosts, in which they establish infections and

  • Arthropoda (animal phylum)

    Arthropod, any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes. About 84 percent of all known species of animals are members of this phylum. Arthropods are

  • arthrosis deformans (pathology)

    Osteoarthritis, disorder of the joints characterized by progressive deterioration of the articular cartilage or of the entire joint, including the articular cartilage, the synovium (joint lining), the ligaments, and the subchondral bone (bone beneath the cartilage). Osteoarthritis is the most

  • Arthur (film by Gordon [1981])

    John Gielgud: …the Orient Express (1974) and Arthur (1981), for which he received an Academy Award for best supporting actor. His last major film role was in Prospero’s Books (1991), based on Shakespeare’s The Tempest. He also directed for the stage.

  • Arthur (constable of France)

    John V (or VI): …later allowed his own brother Arthur to become constable of France when the dauphin was claiming the French crown as Charles VII. Though he made efforts toward a real entente with Charles in the 1430s, John was party to the revolts of the Praguerie in 1440 and the League of…

  • Arthur (Illinois, United States)

    Arthur, village, Douglas and Moultrie counties, east-central Illinois, U.S. It lies about 30 miles (50 km) southwest of Champaign. Founded in 1873 as a railroad switching point, it was originally called Glasgow but was soon renamed for a brother of Robert Hervey, president of the Paris and Decatur

  • Arthur (legendary king of Britain)

    King Arthur, legendary British king who appears in a cycle of medieval romances (known as the Matter of Britain) as the sovereign of a knightly fellowship of the Round Table. It is not certain how these legends originated or whether the figure of Arthur was based on a historical person. The legend

  • Arthur & George (novel by Barnes)

    Julian Barnes: …not in the historical novel Arthur & George (2005), in which one of the title characters is based on Sir Arthur Conan Doyle. In 2011 Barnes published Pulse, a collection of short stories, as well as The Sense of an Ending, a Booker Prize-winning novel that uses an unreliable narrator…

  • Arthur Andersen (American company)

    Arthur Andersen, Arthur Andersen LLP was one of the largest public accounting firms in the 1990s, with more than 85,000 employees operating in 84 countries. During the last decade of the partnership’s life, auditors at several regional offices failed to detect, ignored, or approved accounting

  • Arthur Bell & Sons PLC (British company)

    Guinness: In 1985 the firm acquired Arthur Bell & Sons PLC, a distiller of Scotch whisky, and in 1986 it bought The Distillers Co. PLC, which was the largest Scotch distiller in the world. Guinness’s use of clandestine and apparently illegal stock transactions in acquiring Distillers created a major corporate scandal…

  • Arthur D. Little, Inc. (American company)

    research and development: Independent laboratories: …of organization is represented by Arthur D. Little, Inc., Cambridge, Mass., which is run on strictly commercial lines, seeking to make a commercially viable profit from the resources employed. Only one or two organizations of similar type have been established in western Europe, and they have not grown to a…

  • Arthur Guinness & Sons PLC (Irish company)

    Guinness, former company, incorporated in 1886 as Arthur Guinness Son & Co. Ltd., best known as the brewer of a distinctive dark and creamy stout. In 1997 the company merged with Grand Metropolitan PLC to form Diageo PLC. Guinness remains a brand of that company, which is headquartered in London.

  • Arthur Guinness Son & Co. Ltd. (Irish company)

    Guinness, former company, incorporated in 1886 as Arthur Guinness Son & Co. Ltd., best known as the brewer of a distinctive dark and creamy stout. In 1997 the company merged with Grand Metropolitan PLC to form Diageo PLC. Guinness remains a brand of that company, which is headquartered in London.

  • Arthur I (duke of Brittany)

    Arthur I, duke of Brittany, a grandson of King Henry II of England; he was a rival of his uncle John (king of England from 1199) for several French provinces, both in his own interest and in that of King Philip II Augustus of France. In October 1190 Arthur was recognized as heir presumptive to the

  • Arthur II (duke of Brittany)

    Arthur II, duke of Brittany (1305–12), son of John II and Beatrice of England. By successive marriages before his accession, he acquired the viscounty of Limoges (1275) and the county of Montfort-l’Amaury (1292). During his short reign, the war between Edward I of England and Philip IV of France

  • Arthur III, duc de Bretagne (French military officer)

    Arthur, constable de Richemont, constable of France (from 1425) who fought for Charles VII under the banner of Joan of Arc and later fought further battles against the English (1436–53) in the final years of the Hundred Years’ War. In childhood (1399) he had been given the English title of Earl of

  • Arthur III, Duke of Brittany (French military officer)

    Arthur, constable de Richemont, constable of France (from 1425) who fought for Charles VII under the banner of Joan of Arc and later fought further battles against the English (1436–53) in the final years of the Hundred Years’ War. In childhood (1399) he had been given the English title of Earl of

  • Arthur Kill Bridge (bridge, Elizabeth, New Jersey, United States)

    Arthur Kill Bridge, steel vertical-lift bridge, completed in 1959, spanning the Arthur Kill (channel) between Elizabeth, N.J., and Staten Island, N.Y. The movable section, suspended from two 215-foot- (66-metre-) high towers, is 558 feet (170 m) long and can be raised 135 feet (41 m) above the

  • Arthur M. Sackler Gallery (museum, Washington, District of Columbia, United States)

    Arthur M. Sackler Gallery, Smithsonian Institution museum located on the Mall in Washington, D.C., noted for its collection of Asian art. The foundation of the gallery’s collection was a donation of approximately 1,000 works owned by Arthur M. Sackler, a New York City psychiatrist who also

  • Arthur Murray Party, The (American television show)

    Arthur Murray: …publicity from the television show The Arthur Murray Party (1950–60), hosted by Kathryn Murray and featuring dance instruction, dance contests, singing, and comedy sketches. In the 1960s Arthur Murray’s high-pressure sales tactics and contest promotions came under the scrutiny of the Federal Trade Commission. In 1964 Murray resigned as president,…

  • Arthur Newman (film by Ariola [2012])

    Colin Firth: In the dark comedy Arthur Newman (2012), he starred as a discontented family man who fakes his death and embarks on a journey under an assumed identity. He played a former World War II prisoner of war who goes in search of the Japanese interpreter who tortured him in…

  • Arthur Pass (mountain pass, New Zealand)

    Arthur Pass, road through the Southern Alps, west-central South Island, New Zealand. At an elevation of 3,018 feet (920 metres), it is the lowest pass and the only crossing for motor traffic between the Haast and Lewis passes. It crosses a mountain ridge between peaks 6,000 feet (1,800 metres)

  • Arthur’s Pass (mountain pass, New Zealand)

    Arthur Pass, road through the Southern Alps, west-central South Island, New Zealand. At an elevation of 3,018 feet (920 metres), it is the lowest pass and the only crossing for motor traffic between the Haast and Lewis passes. It crosses a mountain ridge between peaks 6,000 feet (1,800 metres)

  • Arthur’s Seat (hill, Scotland, United Kingdom)

    Edinburgh: City site: One of them, called Arthur’s Seat, the centrepiece of the royal park, has an elevation of 823 feet (251 metres) and dominates the city’s southeastern flank. The valleys between these striking hills were scoured deep and clean by glacial action in the Pleistocene Epoch. Edinburgh has been built on…

  • Arthur’s Theme (Best That You Can Do) (song by Allen, Bacharach, Cross, and Sager)
  • Arthur, Bea (American entertainer)

    Bea Arthur, (Bernice Frankel), American actress (born May 13, 1922, New York, N.Y.—died April 25, 2009, Los Angeles, Calif.), portrayed an outspoken, acerbic-tongued feminist in the television sitcom Maude (1972–78) and a sharp-witted divorcée who shares a home with her mother (played by Estelle

  • Arthur, Chester A. (president of United States)

    Chester A. Arthur, 21st president of the United States. Elected vice president on the Republican ticket of 1880, Arthur acceded to the presidency upon the assassination of President James A. Garfield. As president, he confounded his critics and dismayed many of his friends among the Stalwart

  • Arthur, Chester Alan (president of United States)

    Chester A. Arthur, 21st president of the United States. Elected vice president on the Republican ticket of 1880, Arthur acceded to the presidency upon the assassination of President James A. Garfield. As president, he confounded his critics and dismayed many of his friends among the Stalwart

  • Arthur, Ellen (wife of Chester Arthur)

    Ellen Arthur, wife of Chester A. Arthur, 21st president of the United States. She never served as first lady because she died of pneumonia before her husband assumed office. The president’s sister, Mary Arthur McElroy, acted as White House hostess. Ellen Lewis Herndon was the daughter of naval

  • Arthur, Frederick, Lord Stanley of Preston (Canadian governor-general)

    ice hockey: Early organization: …game when the Canadian governor-general, Frederick Arthur, Lord Stanley of Preston, donated a cup to be given annually to the top Canadian team. The three-foot-high silver cup became known as the Stanley Cup and was first awarded in 1892–93. (The first winner was the Montreal Amateur Athletic Association team, which…

  • Arthur, J. C. (American botanist)

    J.C. Arthur, American botanist who discovered basic facts about the parasitic fungi known as rusts. Graduated from what is now Iowa State University, Ames, in 1872, Arthur received his doctorate at Cornell University, Ithaca, N.Y., in 1886. In 1887 he became professor of botany at Purdue

  • Arthur, Jean (American actress)

    Jean Arthur, American film actress known for her cracked, throaty voice, which accentuated her charm and intelligence in a series of successful comedies. After modeling and performing in small parts on the Broadway stage, Arthur made her screen debut in a silent western, Cameo Kirby (1923). She

  • Arthur, Joseph Charles (American botanist)

    J.C. Arthur, American botanist who discovered basic facts about the parasitic fungi known as rusts. Graduated from what is now Iowa State University, Ames, in 1872, Arthur received his doctorate at Cornell University, Ithaca, N.Y., in 1886. In 1887 he became professor of botany at Purdue

  • Arthur, Nell (wife of Chester Arthur)

    Ellen Arthur, wife of Chester A. Arthur, 21st president of the United States. She never served as first lady because she died of pneumonia before her husband assumed office. The president’s sister, Mary Arthur McElroy, acted as White House hostess. Ellen Lewis Herndon was the daughter of naval

  • Arthur, Owen (prime minister of Barbados)

    Owen Arthur, Barbadian politician who served as prime minister (1994–2008) of Barbados. His economic policies significantly cut unemployment and won his party near-total control of the House of Assembly. Arthur was raised in the parish (subregion) of St. Peter. He earned a bachelor’s degree in

  • Arthur, Owen Seymour (prime minister of Barbados)

    Owen Arthur, Barbadian politician who served as prime minister (1994–2008) of Barbados. His economic policies significantly cut unemployment and won his party near-total control of the House of Assembly. Arthur was raised in the parish (subregion) of St. Peter. He earned a bachelor’s degree in

  • Arthur, Sir George, 1st Baronet (British official)

    Sir George Arthur, 1st Baronet, colonial administrator who was governor of Van Diemen’s Land (now Tasmania) from 1825 to 1836. His efforts to expand the island’s economy were remarkably successful. After army duty in the Napoleonic Wars in Europe and Egypt (1804–14), Arthur served as lieutenant

  • Arthurian legend

    Arthurian legend, the body of stories and medieval romances, known as the matter of Britain, centring on the legendary king Arthur. Medieval writers, especially the French, variously treated stories of Arthur’s birth, the adventures of his knights, and the adulterous love between his knight Sir

  • Arthurian romance

    Arthurian legend, the body of stories and medieval romances, known as the matter of Britain, centring on the legendary king Arthur. Medieval writers, especially the French, variously treated stories of Arthur’s birth, the adventures of his knights, and the adulterous love between his knight Sir

  • Arthus phenomenon (medicine)

    Arthus phenomenon, local swelling, redness, and tissue death following skin injection of soluble antigen into a subject previously immunized by a series of similar injections. The tissue damage is a result of the precipitation of antigen–antibody complexes in the walls of the blood vessels; the

  • arti (Hinduism and Jainism)

    Arti, (Hindi: “the ceremony of lights”) in Hindu and Jain rites, the waving of lighted lamps before an image of a god or a person to be honoured. In performing the rite, the worshiper circles the lamp three times in a clockwise direction while chanting a prayer or singing a hymn. Arti is one of the

  • arti maggiori (Florentine guild)

    Italy: Florence in the 14th century: …the seven major guilds, or arti maggiori—that is, the judges and notaries, the Calimala (bankers and international traders in cloth), the money changers, the silk merchants, the doctors and apothecaries, the wool merchants, and the dealers in furs. Together with dominant figures from five guilds of lesser status (the arti…

  • arti medie (Florentine guild)

    Italy: Florence in the 14th century: …guilds of lesser status (the arti medie, or middle guilds, consisting of the butchers, the shoemakers, the smiths, the stonemasons, and the secondhand dealers), the popolo gathered every two months to elect six priors who ruled Florence as supreme magistrates.

  • Artibeus jamaicensis (mammal)

    Jamaican fruit bat, (Artibeus jamaicensis), a common and widespread bat of Central and South America with a fleshy nose leaf resembling a third ear positioned on the muzzle. The Jamaican fruit bat has gray-brown fur and indistinct, whitish facial stripes. It has no tail, and the membrane stretching

  • Artibeus lituratus (mammal)

    Fruit bat, any of numerous tropical bat species belonging either to the Old World fruit bats (family Pteropodidae), such as flying foxes, or to fruit-eating genera of the American leaf-nosed bats (family Phyllostomidae), especially those of the genus Artibeus (see Jamaican fruit

  • Artibonite River (river, Hispaniola)

    Artibonite River, river, the longest on the island of Hispaniola. It rises in the Cordillera Central (Cibao Mountains) of the Dominican Republic and flows southwest along the border with Haiti and then west and northwest into Haiti and through the fertile Artibonite Plain to enter the Gulf of La

  • artichoke (plant and vegetable)

    Artichoke, (Cynara cardunculus, variety scolymus), large thistlelike perennial plant of the aster family (Asteraceae) grown for its edible flower buds. The thick bracts and the receptacle of the immature flower head, known as the heart, are a culinary delicacy. The artichoke’s flavour is delicate

  • article (grammar)

    Romance languages: The emergence of articles: The definite and indefinite articles were unknown in Latin but developed everywhere in Romance, usually from the Latin demonstrative ille ‘that’ (though in a few parts from reflexive ipse ‘himself’) and the numeral unus ‘one.’ The definite article is proclitic (attaches to the following…

  • Article 231 of the Treaty of Versailles (European history)

    Weimar Republic: The Treaty of Versailles: …the Allies inserted the famous war-guilt clause, article 231:

  • Article 87 (Russian government)

    Russia: The State Duma: …at any time and, under Article 87, to pass emergency decrees when they were not in session.

  • Article IV Consultation (economics)

    International Monetary Fund: Advising borrowing governments: …these contacts, known as “Article IV Consultations,” the IMF attempts to assess each country’s economic health and to forestall future financial problems. The fund also operates the IMF Institute, a department that provides training in macroeconomic analysis and policy formulation for officials of member countries.

  • Articles and Translations for Use and Amusement (Russian journal)

    Mikhayl Mikhaylovich Shcherbatov: …1759 and 1761 in the Articles and Translations for Use and Amusement, Russia’s first scientific and literary journal, which had been founded by Prince M.V. Lomonosov in 1755. These early works paradoxically combine the ideas of the Enlightenment with the pessimistic estimate of human nature and social progress that prompted…

  • articular cartilage (anatomy)

    joint: Articular cartilage: Articular cartilage (cartilage that covers the articulating part of a bone) is of the type called hyaline (glasslike) because thin sections of it are translucent, even transparent. Unlike bone, it is easily cut by a sharp knife. It is deformable but elastic, and…

  • articular nerve (anatomy)

    joint: Articular nerves: The sources of nerve fibres to a joint conform well to Hilton’s law—the nerves to the muscles acting on a joint give branches to that joint as well as to the skin over the area of action of these muscles. Thus, the knee…

  • Articulata (lamp shell)

    lamp shells: Paleontology: The Articulata, diverse and most numerous from Ordovician times to the present, were, in the Cambrian, represented by several specialized forms. Articulate evolution tended toward shell elaboration for bottom dwelling and perfection of feeding mechanisms from the simple looped lophophore to the elaborate lobate and spiral…

  • Articulatae (plant class)

    Equisetopsida, (division Pteridophyta), class of primitive spore-bearing vascular plants. Most members of the group are extinct and known only from their fossilized remains. The sole living genus, Equisetum, order Equisetales, is made up of 15 species of very ancient herbaceous plants, the

  • articulated rear axle (mechanics)

    automobile: Axles: Articulated rear axles offer individual wheel suspension at the rear as well as the front. Individual rear suspension not only eliminates the heavy rear axle housing but also permits lowered bodies with no floor humps, because the transmission and differential gears can be combined in…

  • articulated vehicle

    bus: Modern buses: Articulated buses were first used in Europe in the 1950s. In this arrangement a trailer body is connected to the rear of a conventional front-engine bus by means of a hitch, a flexible diaphragm, and a continuous floor panel with arcuate mating surfaces during turn…

  • articulation (biology)

    Ordovician radiation: In the Early Ordovician Epoch, articulate (jointed) brachiopods, gastropods, and cephalopods appeared in shallow-water habitats as inarticulate brachiopods and trilobites declined in those habitats. Through the remainder of the Ordovician Period, articulate brachiopods and gastropods continued to spread farther offshore as trilobites and inarticulate brachiopods became rarer in all but…

  • articulation (education)

    education: The psychology and pedagogy of Herbart: Herbart speaks of “articulation”—a systematic method of constructing correct, or moral, idea masses in the student’s mind. First the student becomes involved in a particular problem, and then he considers its context. Each of these two stages has a phase of rest and of progress, and thus there…

  • articulation (speech)

    Articulation, in phonetics, a configuration of the vocal tract (the larynx and the pharyngeal, oral, and nasal cavities) resulting from the positioning of the mobile organs of the vocal tract (e.g., tongue) relative to other parts of the vocal tract that may be rigid (e.g., hard palate). This

  • Articuli centum et sexaginta (work by Bruno)

    Giordano Bruno: Works: …of minor works, including the Articuli centum et sexaginta (1588; “160 Articles”) against contemporary mathematicians and philosophers, in which he expounded his conception of religion—a theory of the peaceful coexistence of all religions based upon mutual understanding and the freedom of reciprocal discussion. At Helmstedt, however, in January 1589 he…

  • artículo de costumbres (literature)

    Spanish literature: Costumbrismo: The cuadro de costumbres and artículo de costumbres—short literary sketches on customs, manners, or character—were two types of costumbrista writing, typically published in the popular press or included as an element of longer literary works such as novels. The cuadro was inclined to description for its own sake, whereas the…

  • artifact (archaeology)

    archaeology: …describe, classify, and analyze the artifacts he studies. An adequate and objective taxonomy is the basis of all archaeology, and many good archaeologists spend their lives in this activity of description and classification. But the main aim of the archaeologist is to place the material remains in historical contexts, to…

  • Artificers, Statute of (England [1563])

    apprenticeship: Early history: …conditions of apprenticeship with the Statute of Artificers of 1563, which attempted to limit exclusionary practices and to ensure adequate labour.

  • artificial abrasive

    abrasive: Abrasive materials: their composition and properties: Synthetic abrasives, on the other hand, are the product of considerable processing of raw materials or chemical precursors; they include silicon carbide, synthetic diamond, and alumina (a synthetic form of corundum). Most natural abrasives have been replaced by synthetic materials because nearly all industrial applications…

  • artificial aging (metallurgy)

    metallurgy: Hardening treatments: Aging is done at an elevated temperature that is still well below the temperature at which the precipitate will dissolve. If the alloy is heated still further, the precipitate will coarsen; that is, the finest particles will dissolve so that the average particle size will…

  • artificial body part (medicine)

    Prosthesis, artificial substitute for a missing part of the body. The artificial parts that are most commonly thought of as prostheses are those that replace lost arms and legs, but bone, artery, and heart valve replacements are common (see artificial organ), and artificial eyes and teeth are also

  • artificial breeding

    Artificial insemination, the introduction of semen into the vagina or cervix of a female by any method other than sexual intercourse. The procedure is widely used in animal breeding and is used in humans when a male is sterile or impotent or when a couple suffers from unexplained infertility (when

  • artificial cardiac pacemaker (artificial)

    Pacemaker, electronic cardiac-support device that produces rhythmic electrical impulses that take over the regulation of the heartbeat in patients with certain types of heart disease. A healthy human heart contains its own electrical conducting system capable of controlling both the rate and the

  • artificial contrast agent (medicine)

    Contrast medium, substance comparatively opaque to X ray, which, when present in an organ or tissue, causes a lighter appearance—i.e., a more definite image—on the X-ray film. Some body structures, such as the lungs, show in X-ray films and in fluoroscopic images by virtue of the sharp difference

  • artificial corundum (mining)

    corundum: Artificial corundum may be produced as a specialty product, as for gem use, by slow accretion and controlled growth on a boule in an oxyhydrogen flame. This procedure is known as the Verneuil process (q.v.).

  • artificial flavoring (food)

    flavouring: Imitation, artificial extracts, essences, and flavours: Imitation, artificial extracts, essences, and flavours are prepared by bringing into solution with alcohol, glycerol, or propylene glycol various synthetic flavouring agents to formulate an extract, essence, or flavour with the likeness of the flavour of the fruit, spirit, or…

  • artificial flavouring (food)

    flavouring: Imitation, artificial extracts, essences, and flavours: Imitation, artificial extracts, essences, and flavours are prepared by bringing into solution with alcohol, glycerol, or propylene glycol various synthetic flavouring agents to formulate an extract, essence, or flavour with the likeness of the flavour of the fruit, spirit, or…

  • artificial heart

    Artificial heart, device that maintains blood circulation and oxygenation in the human body for varying periods of time. The two main types of artificial hearts are the heart-lung machine and the mechanical heart. The heart-lung machine is a mechanical pump that maintains a patient’s blood

  • artificial induction (geology)

    earthquake: Artificial induction: Earthquakes are sometimes caused by human activities, including the injection of fluids into deep wells, the detonation of large underground nuclear explosions, the excavation of mines, and the filling of large reservoirs. In the case of deep mining, the removal of rock produces…

  • artificial insemination

    Artificial insemination, the introduction of semen into the vagina or cervix of a female by any method other than sexual intercourse. The procedure is widely used in animal breeding and is used in humans when a male is sterile or impotent or when a couple suffers from unexplained infertility (when

  • artificial intelligence

    Artificial intelligence (AI), the ability of a digital computer or computer-controlled robot to perform tasks commonly associated with intelligent beings. The term is frequently applied to the project of developing systems endowed with the intellectual processes characteristic of humans, such as

  • artificial intelligence programming language

    Artificial intelligence programming language, a computer language developed expressly for implementing artificial intelligence (AI) research. In the course of their work on the Logic Theorist and GPS, two early AI programs, Allen Newell and J. Clifford Shaw of the Rand Corporation and Herbert Simon

  • artificial intelligence, situated approach

    Artificial intelligence, situated approach, method of achieving artificial intelligence (AI). Traditional AI has by and large attempted to build disembodied intelligences whose only interaction with the world has been indirect (CYC, for example). Nouvelle AI, on the other hand, attempts to build

  • artificial kidney (hemodialysis)

    Dialysis, in medicine, the process of removing blood from a patient whose kidney functioning is faulty, purifying that blood by dialysis, and returning it to the patient’s bloodstream. The artificial kidney, or hemodialyzer, is a machine that provides a means for removing certain undesirable

  • artificial language (logic)

    metalogic: …syntax (relations among expressions) of formal languages and formal systems. It is related to, but does not include, the formal treatment of natural languages. (For a discussion of the syntax and semantics of natural languages, see linguistics and semantics.)

  • artificial leaf (technology)

    Artificial leaf, silicon-based device that uses solar energy to split hydrogen and oxygen in water, thereby producing hydrogen energy in a clean way, leaving virtually no pollutants. The technology, which was designed to simulate the natural energy-generating process of photosynthesis used by

  • artificial leather (material)
  • artificial life (computer simulation)

    Artificial life, computer simulation of life, often used to study essential properties of living systems (such as evolution and adaptive behaviour). Artificial life became a recognized discipline in the 1980s, in part through the impetus of American computer scientist Christopher Langton, who named

  • artificial life game, electronic (electronic game genre)

    Electronic artificial life game, electronic game genre in which players nurture or control artificial life (A-life) forms. One of the earliest examples is The Game of Life, a cellular automaton created by the English mathematician John Conway in the 1960s. Following a few simple rules, various

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