beta; B, β +
(Greek: B, β; second letter of the Greek alphabet and the second object in any order of arrangement or classification)
2. A small electrically charged particle thrown off by many radio-active materials.
It is identical to the electron and possesses the smallest negative electric charge found in nature.
Beta particles emerge from radioactive material at high speeds, sometimes close to the speed of light.3. An electron emitted at high velocity from a radioactive atom that is undergoing spontaneous disintegration.
Beta particles do not exist in the nucleus but are created during disintegration, or beta decay, when a neutron converts to a proton to emit an electron.
2. A stream of electrons projected by radioactive substances.
They are identical with cathode rays, possess great penetrative power, and are easily deflected by an electric or magnetic field in a direction opposite to that of the alpha rays.
2. In electroencephalography, a rapid rhythm usually of low voltage, which can be recorded in the motor areas of the brain and sometimes in the frontal regions; especially, during states of stress or anxiety or after the administration of certain drugs such as barbiturates.
3. The second most common waveform occurring in electroencephalograms of the adult brain, characteristically having a frequency from 13 to 30 cycles per second.
It is associated with an alert waking state but can also occur as a sign of anxiety or apprehension.
2. In chemistry, a prefix to indicate isomeric variety or position in compounds of substituted groups.
3. The second of any series, or a second item in a series or system of classification; such as, in chemistry, astronomy, botany, physics, etc.
4. A mathematical measure of the sensitivity of rates of return on a portfolio or a given stock compared with rates of return on the stock market as a whole.
A beta of 1.0 indicates that an asset closely follows the market; a beta greater than 1.0 indicates greater volatility than the market.5. The second position from a designated carbon atom in an organic molecule at which an atom or a radical may be substituted.
6. In computer science, a beta version or beta test; the final stage in the testing of new software before its commercial release, conducted by testers other than its developers.
These agents are used in treating hypertension, angina, certain cardiac arrhythmias, and postmyocardial infarction.
They may also be helpful in preventing migraine and in treating stage fright and benign essential tremor.
A hormone, secreted by the adrenal gland and similar to epinephrine, that is the principal neurotransmitter of sympathetic nerve endings supplying the major organs and skin.
It increases blood pressure and rate and depth of breathing, raises the level of blood sugar, and decreases the activity of the intestines.
2. Medications that reduce heart rate and force contraction as well as dilate blood vessels, lowering blood pressure.
They are prescribed for coronary artery disease; including angina, irregular heart rhythms, and a history of heart attack, as well as, to prevent migraine headaches.
2. A disorder of speech in which the consonant b receives excessive emphasis and other consonants may be pronounced as b.