| magnetoencephalography | The measurement of magnetic fields over the head generated by electric currents in the brain. As in any electrical conductor, electric fields in the brain are accompanied by orthogonal magnetic fields. The measurement of these fields provides information about the localization of brain activity which is complementary to that provided by electroencephalography. Magnetoencephalography may be used alone or together with electroencephalography, for measurement of spontaneous or evoked activity, and for research or clinical purposes. (12 Dec 1998) |
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| magnetograph | <physics> An automatic instrument for registering, by photography or otherwise, the states and variations of any of the terrestrial magnetic elements. Origin: Magneto- + -graph. Source: Websters Dictionary (01 Mar 1998) |
| magnetogyric ratio | In nuclear magnetic resonance, the ratio of the magnetic dipole moment of the nucleus to the nuclear spin angular momentum; the gyromagnetic ratio is a unique value for each type of nucleus. Synonym: magnetogyric ratio. (05 Mar 2000) |
| magnetohydrodynamics | <physics, study> Physical model describing the properties of electrically conducting fluids interacting with magnetic and electric fields. Magnetohydrodynamic theory is relevant at relatively low frequencies and for distance scales larger than the Larmor radius. Synonym: hydromagnetics. (13 Jan 1998) |
| magnetometer | <physics> An instrument for measuring the intensity of magnetic forces; also, less frequently, an instrument for determining any of the terrestrial magnetic elements, as the dip and declination. Origin: Magneto-: cf. F. Magnetometre. Source: Websters Dictionary (01 Mar 1998) |
| magnetometric | Pertaining to, or employed in, the measurement of magnetic forces; obtained by means of a magnetometer; as, magnetometric instruments; magnetometric measurements. Source: Websters Dictionary (01 Mar 1998) |
| magnetomotor | A voltaic series of two or more large plates, producing a great quantity of electricity of low tension, and hence adapted to the exhibition of electromagnetic phenomena. Source: Websters Dictionary (01 Mar 1998) |
| magneton | A unit of measurement of the magnetic moment of a particle (e.g., atom or subatomic particle). Bohr magneton, a constant in the equation relating the difference in energies between parallel and antiparallel spin alignments of electrons in a magnetic field; the net magnetic moment of one unpaired electron; used in electron spin resonance spectrometry for detection and estimation of free radicals. Synonym: electron magneton. (05 Mar 2000) |
| magnetosome | <microbiology> Enveloped compartment in magnetotactic bacteria containing magnetite particles. By using this organelle to detect the vertical component of the Earth's magnetic field, the bacteria swim towards the bottom of the sea. Origin: Gr. Soma = body (18 Nov 1997) |
| magnetotactic bacteria | <microbiology> Bacteria that can orient themselves in the earth's magnetic field due to the presence of magnetosomes. (09 Oct 1997) |
| magnetotaxis | Tactic response to magnetic field, in magnetotactic bacteria the Earth's magnetic field is used as a guide to up and down in deep sediment. (18 Nov 1997) |
| magnetotherapy | <medicine> The treatment of disease by the application of magnets to the surface of the body. Source: Websters Dictionary (01 Mar 1998) |
| magnification | The amplification of an image by using enlarged views to magnify an area for greater detail. (13 Nov 1997) |
| magnification angiography | Enhanced imaging of small blood vessels using an increased distance from subject to film, as in magnification radiography. (05 Mar 2000) |
| magnification empty | <microscopy> Magnification beyond which no new information is revealed. (05 Aug 1998) |