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Leeuwarden

(Encyclopedia)Leeuwarden lāˈvärˌdən [key], Frisian Ljouwert, city (1994 est. pop. 87,500), capital of Friesland prov., N Netherlands. It is the center of an agricultural and dairying region and has a noted cat...

Pánuco

(Encyclopedia)Pánuco päˈno͞okō [key], river, c.315 mi (510 km) long, rising as the Santa María River in San Luis Potosí state, N central Mexico, and flowing generally east to empty into the Gulf of Mexico ne...

tissue culture

(Encyclopedia)tissue culture, the propagation of plants through the placement of small amounts of undifferentiated tissue or single cells in an artificial environment. The tissue is placed in a nutrient medium that...

Theocritus

(Encyclopedia)Theocritus thēŏkˈrĭtəs [key], fl. c.270 b.c., Hellenistic Greek poet, b. Syracuse. The history of the pastoral begins with him, and in him the form seems to have reached its height. His poetic st...

cable television

(Encyclopedia)cable television, the transmission of televised images to viewers by means of coaxial cables. Cable systems receive the television signal, which is sent out over cables to individual subscribers, by a...

communications industry

(Encyclopedia)communications industry, broadly defined, the business of conveying information. Although communication by means of symbols and gestures dates to the beginning of human history, the term generally ref...

gamma-ray astronomy

(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...

Mather, John Cromwell

(Encyclopedia)Mather, John Cromwell, 1946–, American astrophysicist, b. Roanoke, Va., Ph.D. Univ. of California, Berkeley, 1974. He has been a researcher at NASA's Goddard Space Flight Center in Greenbelt, Md., s...

Kroemer, Herbert

(Encyclopedia)Kroemer, Herbert, 1928–, German physicist, Ph.D. Univ. of Göttingen, 1952. Kroemer was a researcher at RCA Laboratories in Princeton, N.J. (1954–57), and at Varian Associates in Palo Alto, Calif....

dog racing

(Encyclopedia)dog racing, trials of speed between dogs. Now contested on oval tracks, the sport developed from the ancient practice of coursing, in which specially trained dogs chase game animals in the open field....