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dream

(Encyclopedia)dream, mental activity associated with the rapid-eye-movement (REM) period of sleep. It is commonly made up of a number of visual images, scenes or thoughts expressed in terms of seeing rather than in...

connective tissue

(Encyclopedia)connective tissue, supportive tissue widely distributed in the body, characterized by large amounts of intercellular substance and relatively few cells. The intercellular material, or matrix, is produ...

Nichols, Mike

(Encyclopedia)Nichols, Mike, 1931–2014, American actor and director, b. Berlin, Germany, as Mikhail Igor Peschkowsky. His family immigrated to the United States in ...

Magellanic Clouds

(Encyclopedia)Magellanic Clouds măjˌəlănˈĭk [key], two dwarf galaxies located in the far southern sky and visible to the unaided eye; they are classified as irregular because they show no definite symmetry or...

Marburg virus disease

(Encyclopedia)Marburg virus disease, formerly known as Marburg virus hemorrhagic fever, disease caused by infection with a Marburg virus, a filovirus that belongs to a family (Filoviridae) of RNA viruses that also ...

Bradbury, Ray

(Encyclopedia)Bradbury, Ray (Raymond Douglas Bradbury) brădˈbĕrˌē, –bərē [key], 1920–2012, American writer, b. Waukegan, Ill. A popular and prolific writer of science fiction who did much to bring the ge...

brittlestar

(Encyclopedia)brittlestar, common name for echinoderms belonging to the class Ophiuroidea. The name is derived from their habit of breaking off arms as a means of defense. New arms are easily regenerated. They are ...

sun grebe

(Encyclopedia)sun grebe, common name for a tropical, mainly aquatic bird of the family Heliornithidae. Sun grebes, also called finfoots, are remarkable for their colorful, puffy-toed, webbed feet, which may serve a...

solid

(Encyclopedia)solid, one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from liquid and gas, in which a substance has both a definite shape and a definite volume....

seasonal affective disorder

(Encyclopedia)seasonal affective disorder (SAD), recurrent fall or winter depression characterized by excessive sleeping, social withdrawal, depression, overeating, and pronounced weight gain. SAD effects an estima...