| memory trace | See: engram. (05 Mar 2000) |
|---|---|
| trace | 1. To mark out; to draw or delineate with marks; especially, to copy, as a drawing or engraving, by following the lines and marking them on a sheet superimposed, through which they appear; as, to trace a figure or an outline; a traced drawing. "Some faintly traced features or outline of the mother and the child, slowly lading into the twilight of the woods." (Hawthorne) 2. To follow by some mark that has been left by a person or thing which has preceded; to follow by footsteps, tracks, or tokens. "You may trace the deluge quite round the globe." (T. Burnet) "I feel thy power . . . To trace the ways Of highest agents." (Milton) 3. Hence, to follow the trace or track of. "How all the way the prince on footpace traced." (Spenser) 4. To copy; to imitate. "That servile path thou nobly dost decline, Of tracing word, and line by line." (Denham) 5. To walk over; to pass through; to traverse. "We do tracethis alley up and down." (Shak) Origin: OF. Tracier, F. Tracer, from (assumed) LL. Tractiare, fr.L. Tractus, p. P. Of trahere to draw. Cf. Abstract, Attract, Contract, Portratt, Tract, Trail, Train, Treat. 1. A mark left by anything passing; a track; a path; a course; a footprint; a vestige; as, the trace of a carriage or sled; the trace of a deer; a sinuous trace. 2. <chemistry> A very small quantity of an element or compound in a given substance, especially when so small that the amount is not quantitatively determined in an analysis;-hence, in stating an analysis, often contracted to tr. 3. A mark, impression, or visible appearance of anything left when the thing itself no longer exists; remains; token; vestige. "The shady empire shall retain no trace Of war or blood, but in the sylvan chase." (Pope) 4. <geometry> The intersection of a plane of projection, or an original plane, with a coordinate plane. 5. The ground plan of a work or works. Syn.-Vestige; mark; token. See Vestige. Origin: F. Trace. See Trace. Source: Websters Dictionary (01 Mar 1998) |
| trace conditioned reflex | A conditioned reflex established by applying the stimulus a short time before reinforcement; in the conditioned reflex of the animal so prepared, the response occurs at the same interval of time after the application of the stimulus as during the period of training. (05 Mar 2000) |
| trace conditioning | Conditioning when there is no temporal overlap between the conditioning stimulus and the unconditioned stimulus. (05 Mar 2000) |
| trace element | Any chemical element that an organism needs very small quantities of tosurvive. (09 Oct 1997) |
| trace elements | A group of chemical elements that are needed in minute quantities for the proper growth, development, and physiology of an organism. (12 Dec 1998) |
| trace nutrient | Essential dietary elements required only in small quantities. They are present in the body in amounts less than .005% of body weight. (12 Dec 1998) |
| alum root | <botany> A North American herb (Heuchera Americana) of the Saxifrage family, whose root has astringent properties. Source: Websters Dictionary (01 Mar 1998) |
| anatomical root | That portion of a tooth extending from the cervical line to its apical extremity. (05 Mar 2000) |
| angelica root | The root of Angelica archangelica (family Umbelliferae); a tonic and stimulant that may cause nausea; used as a carminative, diuretic, and externally as a counterirritant. (05 Mar 2000) |
| anterior root | The motor root of a spinal nerve. Synonym: radix anterior, radix motoria, anterior root, motor root, radix ventralis. (05 Mar 2000) |
| aquatic root | <plant biology> Roots that develop on stems above the normal position occupied by roots, in response to prolonged inundation with water. (09 Oct 1997) |
| arched root | <botany> Roots produced on the plant stems in a position above the normal position of roots, which serve to brace the plant during and following periods of prolonged inundation with water. (09 Oct 1997) |
| black root | <botany> Dried rhizome and roots of Veronicastrum virginicum (family Serophulariaceae). Indigenous to North America. Formerly used as a cathartic. Synonym: black root, Culver's root. (05 Mar 2000) |
| vandal root | <botany> Any plant of the genus Valeriana. The root of the officinal valerian (V. Officinalis) has a strong smell, and is much used in medicine as an antispasmodic. <botany> Greek valerian, a plant (Polemonium caeruleum) with blue or white flowers, and leaves resembling those of the officinal valerian. Origin: LL. Valeriana, perhaps from some person named Valerius, or fr. L. Valere to be strong. Powerful, on account of its medicinal virtues: cf. F. Valeriane. Source: Websters Dictionary (01 Mar 1998) |