| visual threshold | Threshold of visual sensation, the minimal light intensity evoking a visual sensation. Synonym: achromatic threshold, minimum light threshold. (05 Mar 2000) |
|---|---|
| visual violet | A visual pigment, composed of 11-cis-retinal bound to an opsin, found in the cones of the retina. Synonym: visual violet. Origin: G. Ion, violet, + ops, eye, + -in (05 Mar 2000) |
| visual yellow | The orange retinaldehyde resulting from the action of light on the rhodopsin of the retina, which converts the 11-cis-retinal component of the rhodopsin to all-trans-retinal plus opsin. Synonym: trans-retinal, visual yellow. (05 Mar 2000) |
| primary visual area | Area of the occipital lobe concerned with vision. (12 Dec 1998) |
| primary visual cortex | See: visual cortex. (05 Mar 2000) |
| secondary visual area | Area of the occipital lobe concerned with vision. (12 Dec 1998) |
| secondary visual cortex | See: visual cortex. (05 Mar 2000) |
| evoked potentials, visual | The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways. (12 Dec 1998) |
| unformed visual hallucination | Hallucination composed of sparks, lights, or bursting spheres of light. (05 Mar 2000) |
| formed visual hallucination | <psychiatry> Hallucination composed of scenes, often landscapes. (05 Mar 2000) |
| functional visual loss | An apparent loss of visual acuity or visual field with no substantiating physical signs; often due to a natural concern about visual loss combined with suggestibility and a fear of the worst; best treated with reassurance. (05 Mar 2000) |
| anterior white commissure | A narrow band of white substance bordering on the anterior median fissure of the spinal cord in front of the anterior gray commissure, and consisting of nerve fibres crossing over from one half of the spinal cord to the other. Synonym: commissura alba, anterior white commissure, commissura ventralis alba, ventral white column. (05 Mar 2000) |
| blue white colour selection | <molecular biology, procedure> Method for identifying bacterial clones containing plasmids with inserts. Many modern vectors have their polycloning site within a part of the LacZ gene encoding _ galactosidase, which provides _ complementation in an appropriate mutant E. Coli strain. This means that a re ligated (empty) vector will produce blue colonies when grown on plates containing IPTG and X gal, but colonies with a substantial insert in their plasmid's polycloning site are unable to produce functional _ galactosidase and so produce white colonies. (16 Dec 1997) |
| Bouffardi's white mycetoma | <dermatology> A form of mycetoma common in India and found occasionally in Somalia, caused by the organism Streptomyces somaliensis; in this variety, the muscles, tendons, and bones of the foot are destroyed by the disease process; numerous draining sinuses discharge yellowish grains, clustered like fish roe. (05 Mar 2000) |
| Brumpt's white mycetoma | Mycetoma caused by Pseudallescheria boydii, occurring in temperate and subtropical areas in India; small, white to yellow, hard to soft granules are discharged through the draining sinuses. (05 Mar 2000) |