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distortion

(Encyclopedia)distortion, in electronics, undesired change in an electric signal waveform as it passes from the input to the output of some system or device. In an audio system, distortion results in poor reproduct...

polyp and medusa

(Encyclopedia)CE5 Polyp and medusa stages in the life cycle of Obelia, representative of the phylum Cnidaria polyp and medusa, names for the two body forms, one nonmotile and one typically free swimming, found ...

Filson, John

(Encyclopedia)Filson, John, c.1753–1788, Kentucky pioneer, b. Chester co., Pa. In 1783 he acquired land in Kentucky, taught school, and wrote Discovery, Settlement, and Present State of Kentucke (1784). This firs...

Wildsmith, Brian Lawrence

(Encyclopedia)Wildsmith, Brian Lawrence, 1930–2016, English children's book author and illustrator. He attended the Slade School of Fine Art, University College London (1949–52), and served in the army before b...

bulb

(Encyclopedia)bulb, thickened, fleshy plant bud, usually formed under the surface of the soil, which carries the plant over from one blooming season to another. It may have many fleshy layers (as in the onion and h...

life

(Encyclopedia)life, although there is no universal agreement as to a definition of life, its biological manifestations are generally considered to be organization, metabolism, growth, irritability, adaptation, and ...

Chrysophyta

(Encyclopedia)Chrysophyta krəsŏfˈətə [key], phylum (division) of unicellular marine or freshwater organisms of the kingdom Protista consisting of the diatoms (class Bacillariophyceae), the golden, or golden-br...

Schongauer, Martin

(Encyclopedia)Schongauer, Martin märˈtēn shōnˈgou-ər [key], 1430–91, German engraver and painter, son of a goldsmith of Colmar, Alsace. Schongauer's only certain painting is Madonna of the Rose Arbor (1473;...

Roman de la Rose, Le

(Encyclopedia)Roman de la Rose, Le lə rōmäNˈ də lä rōz [key], French poem of 22,000 lines in eight-syllable couplets. It is in two parts. The first (4,058 lines) was written (c.1237) by Guillaume de Lorris a...

selection

(Encyclopedia)selection. In Darwinism, the mechanism of natural selection is considered of major importance in the process of evolution. Popular formulations sometimes envisage a struggle for existence in which dir...