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polycythemia

(Encyclopedia)polycythemia pŏlˌēsīthēˈmēə [key], condition characterized by an increase in the production of red blood cells, or erythrocytes, in the blood. Primary polycythemia, also called erythremia, or ...

variable star

(Encyclopedia)variable star, star that varies, either periodically or irregularly, in the intensity of the light it emits. Other physical changes are usually correlated with the fluctuations in brightness, such as ...

garnet

(Encyclopedia)garnet, name applied to a group of isomorphic minerals crystallizing in the cubic system. They are used chiefly as gems and as abrasives (as in garnet paper). The garnets are double silicates; one of ...

Jupiter, in astronomy

(Encyclopedia)Jupiter jo͞oˈpətər [key], in astronomy, 5th planet from the sun and largest planet of the solar system. Astronomers have discovered 79 satellites orbiting Jupiter, but five of those, small sate...

tornado

(Encyclopedia)tornado, dark, funnel-shaped cloud containing violently rotating air that develops below a heavy cumulonimbus cloud mass and extends toward the earth. The funnel twists about, rises and falls, and whe...

Duroc swine

(Encyclopedia)Duroc swine dŭˈrŏk, do͞oˈ– [key], breed originating during the 1800s in the NE United States from crosses among a number of red strains existing in that region. One of the most numerous breeds,...

alizarin

(Encyclopedia)alizarin əlĭzˈərĭn [key], or 1,2-dihydroxyanthraquinone, mordant vegetable dye obtained originally from the root of the madder plant (Rubia tinctorum), in which it occurs as a glucoside. The term...

Irish terrier

(Encyclopedia)Irish terrier, a breed of hardy working terrier developed in the British Isles and believed to be one of the oldest terriers. It stands about 18 in. (46 cm) high at the shoulder and weighs from 25 to ...

Selkirk, town, Canada

(Encyclopedia)Selkirk, town (1991 pop. 9,815), SE Man., Canada, on the Red River. Just S of Lake Winnipeg, it is a port for products from N Manitoba. There are steel mills, foundries, and shipyards in the town. It ...

Hoyle, Sir Fred

(Encyclopedia)Hoyle, Sir Fred hoil [key], 1915–2001, British astrophysicist and mathematician, b. Bingley, Yorkshire. During the years of World War II, Hoyle primarily worked on technical problems related to rada...