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Allen, Paul Gardner

(Encyclopedia)Allen, Paul Gardner, 1953–2018, American business executive and philanthropist, b. Seattle. He dropped out of Washington State Univ. (1974) and with his friend Bill Gates co-founded (1975) Microsoft...

tamoxifen

(Encyclopedia)tamoxifen təmŏkˈsĭfĕnˌ [key], synthetic hormone used in the treatment of breast cancer. Introduced in 1978, tamoxifen is used to prevent recurrences of cancer in women who have already undergone...

carotene

(Encyclopedia)carotene kârˈətēnˌ [key], long-chained, unsaturated hydrocarbon found as a pigment in many higher plants, particularly carrots, sweet potatoes, and leafy vegetables. Carotene is thought to assist...

bighorn, in zoology

(Encyclopedia)bighorn or Rocky Mountain sheep, wild sheep, Ovis canadensis, of W North America, formerly plentiful in mountains from SW Canada to N Mexico. Indiscriminate hunting, disease, and scarcity of food enor...

Brace, Charles Loring

(Encyclopedia)Brace, Charles Loring, 1826–90, American clergyman and social reformer, b. Litchfield, Conn. America's pioneer children's advocate, he founded (1853) the Children's Aid Society of New York, an organ...

corticosteroid drug

(Encyclopedia)corticosteroid drug kôrˌtəkōstârˈoid [key], any one of several synthetic or naturally occurring substances with the general chemical structure of steroids. They are used therapeutically to mimic...

genetic testing

(Encyclopedia)genetic testing, medical screening for genetic disorders, by examining either a person's DNA directly or a person's biochemistry or chromosomes for indirect evidence. Testing may be done to identify a...

e-commerce

(Encyclopedia)e-commerce, commerce conducted over the Internet, most often via the World Wide Web. E-commerce can apply to purchases made through the Web or to business-to-business activities such as inventory tran...

longevity

(Encyclopedia)longevity lŏnjĕvˈĭtē [key], term denoting the length or duration of the life of an animal or plant, often used to indicate an unusually long life. The average human life-span of threescore and te...

astigmatism

(Encyclopedia)astigmatism əstĭgˈmətĭzˌəm [key], type of faulty vision caused by a nonuniform curvature in the refractive surfaces—usually the cornea, less frequently the lens—of the eye. As a result, lig...