| aged, 80 and over | A person 80 years of age and older. (12 Dec 1998) |
|---|---|
| maternal age 35 and over | Pregnancy in women 35 or more years of age. It is used for normal pregnancies and for problems of pregnancy occurring in a woman's late reproductive years. These include effects on the mother's physical and mental health as well as risks of perinatal mortality and foetal abnormality. (12 Dec 1998) |
| crossing over | <genetics, molecular biology> The breaking during meiosis of one maternal and one paternal chromosome, the reciprocal exchange of corresponding sections of DNA along pairs of homologous chromosomes by symmetrical breakage and crosswise rejoining of the chromosomes. This results in the transfer of a block of genes from each chromosome to its homologue. In contrast to genetic recombination, which is a phenotypic phenomenon, crossing-over is genotypic. Any even number of crossing-overs between two loci will cancel out phenotypically and no recombination will occur. Recombination can result from DNA exchange of alleles between between homologous chromatids in meiosis, giving rise to chiasmata. Compare: recombination. (10 Nov 1998) |
| somatic crossing-over | Crossing-over that occurs during the mitosis of somatic cells, in contrast to that which occurs in meiosis. (05 Mar 2000) |
| drug, over-the-counter | Drug for which a prescription is not needed. (12 Dec 1998) |
| tie-over dressing | A dressing placed over a skin graft or other sutured wound and tied on by the sutures which have been left of sufficient length for that purpose. Synonym: bolus dressing. (05 Mar 2000) |
| unequal crossing over | <cell biology> Crossing over between homologous chromosomes that are not precisely paired, resulting in nonreciprocal exchange of material and chromosomes of unequal length. Favoured in regions containing tandemly repeated sequences. (18 Nov 1997) |
| uneven crossing-over | Unequal crossing-over, crossing-over that happens when the breaks do not occur at precisely homologous points in two chromatid strands, and hence results in localised duplication of genetic material in one chromatid and complementary deletion in the other. (05 Mar 2000) |
| flip-over disease | <disease> A disease of young, fast-growing broiler chickens which causes them to die suddenly with a short, terminal, wing-beating convulsion, whereby they often flip over and die on their backs. (05 Mar 2000) |
| flow-over vaporiser | A device for vaporization of a liquid anaesthetic by causing gases to pass over the anaesthetic or over material saturated with the anaesthetic. (05 Mar 2000) |
| four-strand crossing over | Crossing over with both strands of DNA from each sister chromatid, so that both strands from one chromatid are exchanged for both strands on the other. This is different from the usual case where only one of the two DNA strands on one sister chromatid is exchanged for the one matching strand (of the two strands) on the other sister chromatid. (09 Oct 1997) |
| balanced bite | The simultaneous contacting of the upper and lower teeth on the right and left and in the anterior and posterior occlusal areas in centric and eccentric positions within the functional range; used primarily in reference to the mouth, but also arranged and observed on articulators, developed to prevent a tipping or rotating of the denture bases in relation to the supporting structures. Synonym: balanced articulation, balanced bite. (05 Mar 2000) |
| biscuit bite | A record of the relation of the mandible to the maxillae, the act of recording the relation of the mandible to the maxillae. Synonym: biscuit bite, maxillomandibular registration. (05 Mar 2000) |
| bite | 1. To seize with the teeth, so that they enter or nip the thing seized; to lacerate, crush, or wound with the teeth; as, to bite an apple; to bite a crust; the dog bit a man. "Such smiling rogues as these, Like rats, oft bite the holy cords atwain." (Shak) 2. To puncture, abrade, or sting with an organ (of some insects) used in taking food. 3. To cause sharp pain, or smarting, to; to hurt or injure, in a literal or a figurative sense; as, pepper bites the mouth. "Frosts do bite the meads." 4. To cheat; to trick; to take in. 5. To take hold of; to hold fast; to adhere to; as, the anchor bites the ground. "The last screw of the rack having been turned so often that its purchase crumbled, . . . It turned and turned with nothing to bite." (Dickens) To bite the dust, To bite the ground, to fall in the agonies of death; as, he made his enemy bite the dust. To bite in, to corrode or eat into metallic plates by means of an acid. To bite the thumb at (any one), formerly a mark of contempt, designed to provoke a quarrel; to defy. "Do you bite your thumb at us ?" . To bite the tongue, to keep silence. Origin: OE. Biten, AS. Bitan; akin to D. Bijten, OS. Bitan, OHG. Bizan, G. Beissen, Goth. Beitan, Icel. Bita, Sw. Bita, Dan. Bide, L. Findere to cleave, Skr. Bhid to cleave. Cf. Fissure. 1. To seize something forcibly with the teeth; to wound with the teeth; to have the habit of so doing; as, does the dog bite? 2. To cause a smarting sensation; to have a property which causes such a sensation; to be pungent; as, it bites like pepper or mustard. 3. To cause sharp pain; to produce anguish; to hurt or injure; to have the property of so doing. "At the last it [wine] biteth like serpent, and stingeth like an adder." (Prov. Xxiii. 32) 4. To take a bait into the mouth, as a fish does; hence, to take a tempting offer. 5. To take or keep a firm hold; as, the anchor bites. 1. The act of seizing with the teeth or mouth; the act of wounding or separating with the teeth or mouth; a seizure with the teeth or mouth, as of a bait; as, to give anything a hard bite. "I have known a very good fisher angle diligently four or six hours for a river carp, and not have a bite." (Walton) 2. The act of puncturing or abrading with an organ for taking food, as is done by some insects. 3. The wound made by biting; as, the pain of a dog's or snake's bite; the bite of a mosquito. 4. A morsel; as much as is taken at once by biting. 5. The hold which the short end of a lever has upon the thing to be lifted, or the hold which one part of a machine has upon another. 6. A cheat; a trick; a fraud. "The baser methods of getting money by fraud and bite, by deceiving and overreaching." (Humorist) 7. A sharper; one who cheats. 8. A blank on the edge or corner of a page, owing to a portion of the frisket, or something else, intervening between the type and paper. Origin: OE. Bite, bit, bitt, AS. Bite bite, fr. Bitan to bite, akin to Icel. Bit, OS. Biti, G. Biss. See Bite, v, and cf. Bit. Source: Websters Dictionary (01 Mar 1998) |
| bite analysis | A study of the relations of the occlusal surfaces of opposing teeth and their effect upon related structures. Synonym: bite analysis. (05 Mar 2000) |