Columbia Encyclopedia

Search results

500 results found

Horvitz, H. Robert

(Encyclopedia)Horvitz, H. Robert (Howard Robert Horivtz), 1947–, American geneticist, b. Chicago, Ill., Ph.D. Harvard, 1974. Horvitz has been a professor at the Massachusetts Institute of Technology since 1978. W...

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...

meningitis

(Encyclopedia)meningitis sĕrˌəbrōspīˈnəl [key], acute inflammation of the meninges, the membranes that cover and protect the brain and spinal cord. It can be caused by bacteria, viruses, fungi, or other orga...

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...