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scarlet fever

(Encyclopedia)scarlet fever or scarlatina, an acute, communicable infection, caused by group A hemolytic streptococcal bacteria (see streptococcus) that produce an erythrogenic toxin. The disease is now uncommon, p...

senility

(Encyclopedia)senility sənilˈətē [key], deterioration of body and mind associated with old age. Indications of old age vary in the time of their appearance. Stooped posture, wrinkled skin, decrease in muscle st...

sand dollar

(Encyclopedia)sand dollar, common name for a marine animal in the same phylum as the starfish (see sea star). The sand dollar has a rigid, flattened, disk-shaped test, or shell, made of firmly united plates lying j...

pinworm

(Encyclopedia)pinworm, roundworm, Enterobius vermicularis, worldwide in distribution and the most common source of worm infestation of humans in the United States. Children are more commonly infested than adults. A...

fracture

(Encyclopedia)fracture, breaking of a bone. A simple fracture is one in which there is no contact of the broken bone with the outer air, i.e., the overlying tissues are intact. In a comminuted fracture the bone is ...

gland

(Encyclopedia)gland, organ that manufactures chemical substances. A gland may vary from a single cell to a complex system of tubes that unite and open onto a surface through a duct. The endocrine glands, e.g., the ...

jaundice

(Encyclopedia)jaundice jônˈdĭs, jänˈ– [key], abnormal condition in which the body fluids and tissues, particularly the skin and eyes, take on a yellowish color as a result of an excess of bilirubin. During t...

moa

(Encyclopedia)moa mōˈə [key] [Maori], common name for an extinct flightless bird of New Zealand related to the kiwi, the emu, the cassowary, and the ostrich. The various species ranged in size from that of a tur...

molting

(Encyclopedia)molting, periodical shedding and renewal of the outer skin, exoskeleton, fur, or feathers of an animal. In most animals the process is triggered by secretions of the thyroid and pituitary glands. Near...

Nuer

(Encyclopedia)Nuer no͞oˈər, no͝or [key], a Nilotic people living around Lake No in South Sudan. Their economy and social life generally revolve around cattle, which are grazed on the plains during the dry seaso...