| NHCP | nonhistone chromosomal protein |
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| RMSCR | rhabdomyosarcoma chromosomal region |
| aberration, spherical | <optics> A lens defect whereby image forming rays of one colour, passing through the outer zones of a lens come to focus at a different distance from the lens than do those of more central rays. With a simple spherical (or plano-spherical) lens the outer rays always meet the axis closer to the lens than do more central rays and the lens is uncorrected or undercorrected. When the reverse is true the lens has been overcorrected. (05 Aug 1998) |
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| ventricular aberration | Abnormal intraventricular conduction of a supraventricular beat, especially where surrounding beats are normally conducted. Synonym: ventricular aberration. (05 Mar 2000) |
| mental aberration | Disturbed thought or behaviour that connotes a psychological or psychiatric impairment. See: delusion. (05 Mar 2000) |
| meridional aberration | An aberration produced in the plane of a single meridian of a lens. (05 Mar 2000) |
| chromatic 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) |
| chromosome aberration | Any deviation from the normal number or morphology of chromosomes; also the phenotypic consequences thereof. (05 Mar 2000) |
| monochromatic aberration | A defect in an optical image arising because of the nature of lenses; the main types are spherical, coma, curvature, and distortion aberration, and astigmatism of oblique pencils. (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) |
| coma aberration | The distortion of image formation created when a bundle of light rays enters an optical system not parallel to the optic axis. <botany> Any tuft, as the hairs on a seed, or the greenery on a radish or a pineapple. Synonym: coma. Origin: G. Kome, hair, foliage (05 Mar 2000) |
| curvature aberration | Lack of spatial correspondence causing the image of a straight extended object to appear curved. (05 Mar 2000) |
| spherical aberration | <microscopy> A lens defect in which image forming rays passing through the outer zones of the lens focus at a distance from the principal plane, different from that of the rays passing through the centre of the lens. The aberration caused by (near-paraxial) monochromatic light rays or electron beams passing through different radii of a lens not coming to the same focus. (05 Aug 1998) |
| newtonian 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) |
| dioptric aberration | <microscopy> A lens defect in which image forming rays passing through the outer zones of the lens focus at a distance from the principal plane, different from that of the rays passing through the centre of the lens. The aberration caused by (near-paraxial) monochromatic light rays or electron beams passing through different radii of a lens not coming to the same focus. (05 Aug 1998) |
| distortion aberration | The faulty formation of an image arising because the magnification of the peripheral part of an object is different from that of the central part when viewed through a lens. (05 Mar 2000) |
| optical aberration | Failure of rays from a point source to form a perfect image after traversing an optical system. (05 Mar 2000) |