a site on a cell that, upon interaction with epinephrine or norepinephrine, controls vasoconstriction, intestinal relaxation, pupil dilation, and other physiological processes.
- Alpha rhythm
a pattern of slow brain waves (alpha waves) in normal persons at rest with closed eyes, thought by some to be associated with an alert but daydreaming mind. noun (physiol) the normal bursts of electrical activity from the cerebral cortex of a drowsy or inactive person, occurring at a frequency of 8 to 12 hertz […]
- Alpha-stannic acid
See under . any of the series of acids usually occurring as amorphous powders and varying in composition from H 2 SnO 3 (alpha-stannic acid) to H 4 SnO 4 .
- Alpha test
an early test of new or updated software or hardware conducted by the developers or manufacturers prior to beta-testing by potential users. to subject (software or hardware) to an alpha test. Historical Examples The alpha test included 212 questions in all, and a correct answer to any question netted the subject one point. Psychology Robert […]
- Alpha stock
noun any of the most active securities on the Stock Exchange of which there are between 100 and 200; at least ten market makers must continuously display the prices of an alpha stock and all transactions in them must be published immediately