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radiation sickness

(Encyclopedia)radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a disturbance in ...

infrared radiation

(Encyclopedia)infrared radiation, electromagnetic radiation having a wavelength in the range from c.75 × 10−6 cm to c.100,000 × 10−6 cm (0.000075–0.1 cm). Infrared rays thus occupy that part of the electrom...

Zika virus

(Encyclopedia)Zika virus zēˈkə [key], single-stranded RNA virus of the genus flavivirus that infects human and primates and causes a disease known as Zika fever or zika. It is primarily transmitted by the bite o...

Van Dyck, Sir Anthony

(Encyclopedia)Van Dyck or Vandyke, Sir Anthony both: văn dīk [key], 1599–1641, Flemish portrait and religious painter and etcher, b. Antwerp. In 1618 he was received as a master in the artists' guild, but even ...

Edison, Thomas Alva

(Encyclopedia)Edison, Thomas Alva, 1847–1931, American inventor, b. Milan, Ohio. A genius in the practical application of scientific principles, Edison was one of the greatest and most productive inventors of his...

complex ion

(Encyclopedia)complex ion, charged molecular aggregate (see ion), consisting of a metallic atom or ion to which is attached one or more electron-donating molecules. In some complex ions, such as sulfate, SO4−2, t...

cubism

(Encyclopedia)cubism, art movement, primarily in painting, originating in Paris c.1907. In painting the several sources of cubist inspiration included the later work of Cézanne; the geometric forms and compresse...

Alcott, Bronson

(Encyclopedia)Alcott, Bronson ôlˈkət, ăl–, –kŏt [key], 1799–1888, American educational and social reformer, b. near Wolcott, Conn., as Amos Bronson Alcox. His meager formal education was supplemented by ...

anemia

(Encyclopedia)anemia ənēˈmēə [key], condition in which the concentration of hemoglobin in the circulating blood is below normal. Such a condition is caused by a deficient number of erythrocytes (red blood cell...

Audubon, John James

(Encyclopedia)Audubon, John James ôˈdəbŏn [key], 1785–1851, American ornithologist, b. Les Cayes, Santo Domingo (now Haiti). The illegitimate son of a French sea captain and plantation owner and a Creole cham...