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Long Island, island, United States

(Encyclopedia)Long Island (1990 pop. 6,861,454), 1,723 sq mi (4,463 sq km), 118 mi (190 km) long, and from 12 to 20 mi (19–32 km) wide, SE N.Y.; fourth largest island of the United States and the largest outside ...

Farm Credit Administration

(Encyclopedia)Farm Credit Administration (FCA), an independent agency of the executive branch of the federal government that supervises and regulates the Farm Credit System (FCS) for American agriculture. The Farm ...

dark matter

(Encyclopedia)dark matter, material that is believed to make up nearly 27% of the mass of the universe but is not readily visible because it neither emits nor reflects electromagnetic radiation, such as light or ra...

nuclear winter

(Encyclopedia)nuclear winter, theory holding that the smoke and dust produced by a large nuclear war would result in a prolonged period of cold on the earth. The earliest version of the theory, which was put forwar...

obsidian

(Encyclopedia)obsidian ŏbsĭdˈēən [key], a volcanic glass, homogeneous in texture and having a low water content, with a vitreous luster and a conchoidal fracture. The color is commonly black, but may be some s...

lignite

(Encyclopedia)lignite lĭgˈnīt [key] or brown coal, carbonaceous fuel intermediate between coal and peat, brown or yellowish in color and woody in texture. It contains more moisture than coal and tends to dry and...

mammography

(Encyclopedia)mammography, diagnostic procedure that uses low-dose X rays to detect abnormalities in the breasts. Tomosynthesis, also known as 3D mammography, is form of mammography that combines X-ray images taken...

Saint Charles

(Encyclopedia)Saint Charles. 1 City (1990 pop. 22,501), Kane co., NE Ill., on the Fox River, a suburb of Chicago; inc. 1850. Located in an agricultural area (corn and soybeans), the city has food-processing, alumin...

Schick test

(Encyclopedia)Schick test, diagnostic test designed to evaluate susceptibility to diphtheria. A small amount of diphtheria toxin is injected into the skin; the injection will produce an area of redness and swelling...

diapensia

(Encyclopedia)diapensia dīəpĕnˈsēə [key], common name for the Diapensiaceae, a family of low evergreen shrubs native to cool and arctic regions of the Northern Hemisphere. The species that are restricted to t...