Gwent Historical region, southeastern Wales. Its heart is the plain of Gwent, and it includes a coastal plain along the River Severn estuary. Gwent was and still is the gateway between England and southern Wales. The Romans built a military headquarters and major fortress in Gwent, and the Normans erected castles. Formerly a Welsh county (1974-96), it has since been divided into several unitary authorities. The economy of the region relies on both agriculture and industry.
Gwyn, Nell orig. Eleanor Gwyn (b. Feb. 2,1650, London, Eng.—d. Nov. 14, 1687, London) British actress. She was selling oranges at the Drury Lane Theatre when she became the mistress of its leading actor, Charles Hart, who trained her for the stage. She became the leading come¬ dienne of the King’s Company (1666-69) and as “pretty, witty Nell” was in demand as a speaker of impudent prologues and epilogues. She became the mistress of Charles II (1669-85) and was popular with the public, who found her high spirits and frank recklessness welcome antidotes to Puri¬ tanism.
Gwynedd or Gwyneth \'gwi-,neth\ County (pop., 2001: 116,838), northwestern Wales. It encompasses most of the historic counties of Caer¬ narfonshire and Merioneth. Its administrative centre is Caernarfon. The ancient region of Gwynedd comprised most of northern Wales. The Nor¬ mans built castles at Caernarfon and Conwy but did not penetrate inland. It thus remained a stronghold of Welsh culture, with a high proportion of Welsh-speaking people. The landscape is mostly mountains of old hard rock cut by Ice Age glaciers. It includes Snowdonia National Park (1951), which covers about half its total area. Tourism is economically important.
gymnasium In Germany, a state-maintained secondary school that pre¬ pares pupils for higher academic education. This type of nine-year school originated in Strasbourg in 1537. Though the usual graduation age is 19 or 20, pupils may terminate their studies at age 16 and enter a vocational school. Secondary or postprimary education is also provided by middle schools ( Mittelschulen ), teachers’ colleges, and commercial schools.
gymnastics Competitive sport in which individuals perform optional and prescribed acrobatic exercises, mostly on special apparatus, in order to demonstrate strength, balance, and body control. Part of the ancient Olym¬ pic Games, gymnastics was virtually reinvented in the modern era by the German Friedrich Jahn (1778-1852). The sport became part of the revived Olympics in 1896; women’s gymnastics was instituted in 1936. Men’s events include the horizontal bar, parallel bars, pommel horse, vaulting, rings, and floor exercises. Women’s events include the balance beam, uneven par¬ allel bars, vaulting, floor exercises, and rhythmic sportive gymnastics.
gymnosperm Vjim-no-.spornA Any woody plant that reproduces by means of a seed (or ovule) in direct contact with the environment, as opposed to an angiosperm, or flowering plant, whose seeds are enclosed by mature ovaries, or fruits. The four surviving gymnosperm divisions are Coniferophyta (conifers, the most widespread), Cycadophyta (cycads), Ginkgophyta (ginkgos), and Gnetophyta. More than half are trees; most of the rest are shrubs. Gymnosperms occur on all continents except Antarc¬
tica, and especially in the temperate latitudes. Those widely found in the Northern Hemisphere are junipers, firs, larches, spruces, and pines; in the Southern Hemisphere, podocarps ( Podocarpus ). The wood of gymno¬ sperms is often called softwood to differentiate it from the hardwood of angiosperms. Many timber and pulp trees are also planted as ornamentals. Gymnosperms also are a minor source of food; of essential oils used in soaps, air fresheners, disinfectants, pharmaceuticals, cosmetics, and per¬ fumes; of tannin, used for curing leather; and of turpentines. Gymnosperms were a major component in the vegetation that was compressed over mil¬ lions of years into coal. Most are evergreen. They produce male and female reproductive cells in separate male and female strobili (see cone).
gynecology See obstetrics and gynecology
gynecomastia V.gl-no-ko-'mas-te-oV Breast enlargement in a male. It usually involves only the nipple and nearby tissue of one breast. More rarely, the whole breast grows to a size normal in a female. True gyneco¬ mastia is related to an increase in estrogens. Testicular or pituitary-gland tumours commonly cause gynecomastia. Similar conditions (pseudogy¬ necomastia) are caused by excessive body fat, inflammatory disorders, granular lesions, or growth of tumours. Treatment involves hormone therapy, correction of the estrogen disorder, or tumour removal.
gypsum Vjip-S9m\ Common sulfate mineral, hydrated calcium sulfate (CaS0 4 -2H 2 0), of great commercial importance. Deposits occur in many countries, but the U.S., Canada, France, Italy, and Britain are among the leading producers. Crude gypsum is used as a fluxing agent, soil condi¬ tioner, filler in paper and textiles, and retarder in portland cement. About three-fourths of the total production is calcined for use as plaster of paris and as building materials in plaster, board products, and tiles and blocks.
Gypsy see Rom
gypsy moth Species (. Lymantria dispar) of tussock moth, a serious pest of trees. The European strain was introduced into eastern North America c. 1869. The heavy-bodied, weak-flying female is white with black zig¬ zag markings and a wingspan of 1.5-2 in. (38-50 mm). The smaller, darker male is a stronger flier. The voracious larvae can completely defo¬ liate deciduous trees within weeks. The larger Asian gypsy moth (wing¬ span of about 3.5 in., or 90 mm) is even more threatening because the female is a stronger flier, enabling it to spread quickly, and the larvae eat the leaves of both conifers and deciduous trees. It was introduced into northwestern North America in 1991. Sprayed insecticides remain the most effective means of control.
Gypsy Rose Lee See Gypsy Rose Lee
gyrfalcon Vjsr-.fal-konV Arctic bird of prey ( Falco rusticolus), the larg¬ est falcon. It may reach 2 ft (60 cm) in length. It breeds only in the North Pole region (and in some Central Asian highlands) but is sometimes seen at lower latitudes when food is scarce. It varies from pure white with black speckling to dark gray with barring. Its legs are fully feathered.
It hunts near the ground for hares, rodents, and birds of the tundra and seacoast. In traditional falconry, the gyrfalcon was the bird of kings.
gyroscope Vjl-re- I skop\ A mechanical or optical device used to maintain orientation during motion.
A mechanical gyroscope consists of a rapidly spinning wheel set in a framework that permits it to tilt freely in any direction or to rotate about any axis. The momentum of such a wheel causes it to retain its attitude when the framework is tilted. An optical gyroscope, laser or fibre, measures the inter¬ ference pattern generated by two light beams, traveling in opposite direc¬ tions within a mirrored ring or fibre loop, in order to detect very small changes in motion. Gyroscopes are used in compasses, in automatic pilots on ships and aircraft, in the steering mechanisms of torpedoes, in antiroll equipment on large ships, and in inertial guidance systems.
Gyrfalcon (Falco rusticolus ) with prey.
SHELLY GROSSMAN/WOODFIN CAMP & ASSOCIATES
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822 I H-R diagram ► habituation
H-R diagram See Hertzsprung-Russell diagram
Ha-erh-pin See Harbin
Ha Jin (b. Feb. 21, 1956, Jinzhou, China) Chinese-U.S. writer. He joined the army at age 14. He received a doctorate at Brandeis University in the U.S., where he remained. His book of stories Under the Red Flag (1997) concerns the Cultural Revolution. His novel Waiting (1999), about Chi¬ nese society, won the National Book Award, as well as the 2000 PEN/ Faulkner Award for fiction.
Haakon IV Haakonsson \ , ha-kon... , ha-k6ns- l s6n\ known as Haa¬ kon the Old (b. 1204, Norway—d. December, 1263, Orkney Islands) King of Norway (1217-63). After he became king, his mother answered doubts about his pater¬ nity (he was the illegitimate son of Haakon III) by passing through an ordeal of hot irons. He estab¬ lished Norwegian sovereignty over Iceland and Green¬ land (1261-62) and died defending the Hebrides and the Isle of Man from the Scots. He was a noted patron of the arts, and his reign began the “golden age” in medieval Norwegian history.