| thermal spectrum | The part of the invisible spectrum of wave length just longer than that of visible red light. Synonym: thermal spectrum. (05 Mar 2000) |
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| toxin spectrum | A figure in the form of a spectrum used by Ehrlich to represent the neutralizing power of antitoxin in the presence of toxin, toxone, etc. (05 Mar 2000) |
| excitation spectrum | Fluorescence produced over a range of wavelengths of the exciting light. (05 Mar 2000) |
| ultraviolet spectrum | The electromagnetic spectrum beyond the violet end of the visible spectrum. (05 Mar 2000) |
| fluorescence spectrum | Fluorescence evoked over a range of wavelengths when the excitation wavelength is at a maximum. (05 Mar 2000) |
| fortification spectrum | The zigzag banding of light, resembling the walls of fortified medieval towns, that marks the margin of the scintillating scotoma of migraine. Synonym: fortification figures, telehopsias. (05 Mar 2000) |
| frequency spectrum | The range of frequencies in a signal, used to describe the resolving power of an imaging system in radiology. (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) |
| Reuss' colour tables | An obsolete charts in which coloured letters are printed on coloured backgrounds in such combination that some of them are invisible to a person with deficient colour vision. Synonym: Stilling colour tables. (05 Mar 2000) |
| colour | 1. That aspect of the appearance of objects and light sources that may be specified as to hue, lightness (brightness), and saturation. 2. That portion of the visible (370-760 nm) electromagnetic spectrum specified as to wavelength, luminosity, and purity. Origin: L. (05 Mar 2000) |
| colour aberration | When using white light through a lens system, it is inevitable that different wave lengths (colours) are brought to a focus at slightly different points. As a consequence, there are chromatic aberations in the image, good microscope objectives are therefore corrected for this at two wave lengths (achromats) or at three wave lengths (apochromats), as well as for spherical aberration. (18 Nov 1997) |
| colour agnosia | The inability to name or identify specific colours by sight; caused by lesions of the dominant occipital and temporal lobes. (05 Mar 2000) |
| colour blindness | A sex-linked inherited condition where there is an inability to distinguish colours. Very few women are colour blind, but up to 10% of all men have some degree of colour blindness. The most common for is red-green colour blindness. The second most common is blue-yellow. Inheritance: sex-linked (X chromosome). (27 Sep 1997) |
| colour constancy | Unchanging perception of the colour of an object despite changes in lighting or viewing conditions. (05 Mar 2000) |
| colour-contrast microscope | <instrument> A type of microscope in which the condenser stop is of one colour and the annulus is a complement of it so that unstained objects are observed in one colour on a field of the other. (05 Mar 2000) |