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National Estuarine Research Reserve System

(Encyclopedia)National Estuarine Research Reserve System: see under National Marine Sanctuary Program. ...

New York State Canal System

(Encyclopedia)New York State Canal System, waterway system, 524 mi (843 km) long, traversing New York state and connecting the Great Lakes with the Finger Lakes, the Hudson River, and Lake Champlain. The waterway, ...

Sierra Madre, mountain system, Mexico

(Encyclopedia)Sierra Madre dĕl so͝orˈ [key] is a tumbled, broken mass of uptilted mountains that touch the Pacific coast but form into no clearly defined range. It spreads over S Mexico between the volcanic belt...

acetylcholine

(Encyclopedia)acetylcholine əsētˌəlkōˈlēn [key], a small organic molecule liberated at nerve endings as a neurotransmitter. It is particularly important in the stimulation of muscle tissue. The transmission ...

brain stem

(Encyclopedia)brain stem, lower part of the brain, adjoining and structurally continuous with the spinal cord. The upper segment of the human brain stem, the pons, contains nerve fibers that connect the two halves ...

thyroxine

(Encyclopedia)thyroxine thīrŏkˈsēn [key], substance secreted by the thyroid gland. The hormone thyroxine forms by combining the amino acid tyrosine with iodine. Complexed to a protein, it is stored in the folli...

drug poisoning

(Encyclopedia)drug poisoning, toxic effects caused by an administered drug. Worldwide more than 9 million natural and synthetic chemicals have been identified; fewer than 3000 cause more than 95% of acidental and d...

cybernetics

(Encyclopedia)cybernetics [Gr.,=steersman], term coined by American mathematician Norbert Wiener to refer to the general analysis of control systems and communication systems in living organisms and machines. In cy...

chorea

(Encyclopedia)chorea kərēˈə, kō– [key] or St. Vitus's dance, acute disturbance of the central nervous system characterized by involuntary muscular movements of the face and extremities. The disease, known al...

Greengard, Paul

(Encyclopedia)Greengard, Paul, 1925–2019, American neuroscientist, b. New York City, Ph.D. Johns Hopkins, 1953. Greengard was on the staff at Geigy Research Laboratories (1959–67) and a professor at the Albert ...