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adrenocorticotropic hormone

(Encyclopedia)adrenocorticotropic hormone ədrēˈnōkôrˌtəkōtrŏpˈĭk [key], polypeptide hormone secreted by the anterior pituitary gland. Its chief function is to stimulate the cortex of the adrenal gland to...

Seymour, Horatio

(Encyclopedia)Seymour, Horatio sēˈmôr, sēˈmər [key], 1810–86, American politician, b. Pompey Hill, N.Y. He studied law at Utica, N.Y. and was admitted to the bar in 1832. A Democrat, he was military secreta...

sleep apnea

(Encyclopedia)sleep apnea, episodes of interrupted breathing during sleep. Obstructive sleep apnea is a common disorder in which relaxation of muscles in the throat repeatedly close off the airway during sleep; the...

Chalcedon, Council of

(Encyclopedia)Chalcedon, Council of, fourth ecumenical council, convened in 451 by Pulcheria and Marcian, empress and emperor of the East, to settle the scandal of the Robber Synod and to discuss Eutychianism (see ...

Mariana Trench

(Encyclopedia)Mariana Trench or Marianas Trench, mârˌēănˈəz [key], elongated depression on the Pacific Ocean floor, 210 mi (338 km) SW of Guam. It is the deepest known depression on the earth's surface, havin...

Pratt, Charles, 1st Earl Camden

(Encyclopedia)Pratt, Charles, 1st Earl Camden, 1714–94, British jurist. Appointed (1761) chief justice of the Court of Common Pleas, he earned wide popularity as a result of his ruling in Entick v. Carrington (17...

stamen

(Encyclopedia)stamen, one of the four basic parts of a flower. The stamen (microsporophyll), is often called the flower's male reproductive organ. It is typically located between the central pistil and the surround...

Barth, John

(Encyclopedia)Barth, John bärth [key], 1930–, American writer, b. Cambridge, Md. He attended Johns Hopkins (B.A. 1951, M.A. 1952), and, beginning in 1973, taught writing at its graduate school for nearly 20 year...

productivity

(Encyclopedia)productivity, in economics, the output of any aspect of production per unit of input. It is a measure of the output of a worker, machine, or an entire national economy in the creation of goods and ser...

denaturation

(Encyclopedia)denaturation, term used to describe the loss of native, higher-order structure of protein molecules in solution. Most globular proteins exhibit complicated three-dimensional folding described as secon...