| instrascene dynamic range | <microscopy> The greatest ratio of highlight to shadow brightness to within a single scene that a video camera (tube) can handle usefully. Contrast with the usable light range of a camera, which is considerably greater than the instrascene dynamic range. See: illumination, Kohler. (05 Aug 1998) |
|---|---|
| instream cover | Areas of shelter in a stream channel that provide aquatic organisms protection from predators or competitors and/or a place in which to rest and conserve energy due to a reduction in the force of the current. (09 Oct 1997) |
| instream flow incremental methodology | Technique to predict the biomass of a fish species or life stage that a stream reach can support at a given flow, given knowledge of the fishes' physical habitat preferences. (09 Oct 1997) |
| instruction | The act of furnishing with authoritative directions. (18 Nov 1997) |
| instructive theory | Theory of antibody production, now considered untenable, in which antigen acted as template for the production of specific antibody as opposed to the clonal selection theory in which pre existing variation occurs and appropriate clones are selectively expanded. (18 Nov 1997) |
| instructress | A woman who instructs; a preceptress; a governess. Source: Websters Dictionary (01 Mar 1998) |
| instrument | A tool or implement. Origin: L. Instrumentum (05 Mar 2000) |
| instrumental | 1. Acting as an instrument; serving as a means; contributing to promote; conductive; helpful; serviceable; as, he was instrumental in conducting the business. "The head is not more native to the heart, The hand more instrumental to the mouth." (Shak) 2. Pertaining to, made by, or prepared for, an instrument, especially. A musical instrument; as, instrumental music, distinguished from vocal music. "He defended the use of instrumental music in public worship." "Sweet voices mix'd with instrumental sounds." (Dryden) 3. Applied to a case expressing means or agency; as, the instrumental case. This is found in Sanskrit as a separate case, but in Greek it was merged into the dative, and in Latin into the ablative. In Old English it was a separate case, but has disappeared, leaving only a few anomalous forms. Instrumental errors, those errors in instrumental measurements, etc, which arise, exclusively from want of mathematical accuracy in an instrument. Origin: Cf. F. Instrumental. Source: Websters Dictionary (01 Mar 1998) |
| instrumental amusia | Loss of ability to play a musical instrument. (05 Mar 2000) |
| instrumental conditioning | Conditioning in which the response is a prerequisite to achieving some goal; often used as a synonym for operant conditioning, but some psychologists make distinctions in the usages of these two terms. (05 Mar 2000) |
| instrumentarium | A collection of instruments and other equipment for an operation or for a medical procedure. (05 Mar 2000) |
| instrumentation | 1. The use of instruments. 2. In dentistry, the application of armamentarium in a restorative procedure. (05 Mar 2000) |
| insuccation | The act of soaking or moistening; maceration; solution in the juice of herbs. "The medicating and insuccation of seeds." (Evelyn) Origin: L. Insucare, insucatum, to soak in; pref. In- + succus, sucus, sap. Source: Websters Dictionary (01 Mar 1998) |
| insudate | Fluid swelling within an arterial wall (ordinarily serous), differing from an exudate in that it does not come to lie extramurally. Origin: L. In, in, + sudo, pp. -atus, to sweat (05 Mar 2000) |
| insufficiency | The condition of being insufficient or inadequate to the performance of the allotted duty. Origin: L. Insufficientia, from sufficiens = sufficient (18 Nov 1997) |