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osmosis

(Encyclopedia)osmosis ŏzmōˈsĭs [key], transfer of a liquid solvent through a semipermeable membrane that does not allow dissolved solids (solutes) to pass. Osmosis refers only to transfer of solvent; transfer o...

plague

(Encyclopedia)plague, any contagious, malignant, epidemic disease, in particular the bubonic plague and the black plague (or Black Death), both forms of the same infection. These acute febrile diseases are caused b...

poliomyelitis

(Encyclopedia)poliomyelitis pōˌlēōmīˌəlīˈtĭs [key], polio, or infantile paralysis, acute viral infection, mainly of children but also affecting older persons. Historically, there were three immunologic ty...

Sumer

(Encyclopedia)Sumer so͝o-mērˈēən [key]. The term Sumer is used today to designate the southern part of ancient Mesopotamia. From the earliest date of which there is any record, S Mesopotamia was occupied by a ...

beaver

(Encyclopedia)beaver, either of two large aquatic rodents, Castor fiber and Castor canadensis, known for their engineering feats. They were once widespread in N and central Eurasia except E Siberia, and in North Am...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

adoption

(Encyclopedia)adoption, act by which the legal relation of parent and child is created. Adoption was recognized by Roman law but not by common law. Statutes first introduced adoption into U.S. law in the mid-19th c...

motion picture photography

(Encyclopedia)motion picture photography or cinematography, photographic arts and techniques involved in making motion pictures. See also photography, still. Cinematography developed as a separate craft ve...

Dickinson, Emily

(Encyclopedia)Dickinson, Emily, 1830–86, American poet, b. Amherst, Mass. She is widely considered one of the greatest poets in American literature. Her unique, gemlike lyrics are distillations of profound feelin...

ameba

(Encyclopedia)ameba or amoeba both: əmēˈbə [key], common name for certain one-celled organisms belonging to the phylum Sarcodina of the kingdom Protista. Amebas were previously classified as members of the anim...