| aversive conditioning | <psychology> A form of behaviour training or modification in which a noxious event is used to punish or extinguish undesirable behaviour. See: aversion therapy. Synonym: aversive conditioning. (05 Mar 2000) |
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| aversive control | <psychology> Control of the behaviour of another individual by use of psychologically noxious means; e.g., attempting to force better study habits by withholding a child's allowance, or withholding sexual contact unless the partner complies with a request. (05 Mar 2000) |
| aversive stimulus | <psychology> A noxious stimulus such as an electric shock used in aversive training or conditioning. See: aversive training. (05 Mar 2000) |
| aversive therapy | <psychology> A treatment that suppresses undesirable behaviour by simultaneously exposing the subject to unpleasant consequences. (12 Dec 1998) |
| aversive training | <psychology> A form of behaviour training or modification in which a noxious event is used to punish or extinguish undesirable behaviour. See: aversion therapy. Synonym: aversive conditioning. (05 Mar 2000) |
| aves | <ornithology, zoology> The class of Vertebrata that includes the birds. Aves, or birds, have a complete double circulation, oviparous, reproduction, front limbs peculiarly modified as wings; and they bear feathers. All existing birds have a horny beak, without teeth; but some Mesozoic fossil birds (Odontornithes) had conical teeth inserted in both jaws. The principal groups are: Carinatae, including all existing flying birds; Ratitae, including the ostrich and allies, the apteryx, and the extinct moas; Odontornithes, or fossil birds with teeth. The ordinary birds are classified largely by the structure of the beak and feet, which are in direct relating to their habits. See Beak, Bird, Odontonithes. Origin: L, pl. Of avis bird. Source: Websters Dictionary (01 Mar 1998) |
| aVF | <abbreviation> Augmented electrocardiographic leads from the foot. (05 Mar 2000) |
| aviadenovirus | <virology> A genus of adenoviridae that infects birds. The type species is fowl adenovirus 1 also called celo virus (chick embryo lethal orphan virus). (12 Dec 1998) |
| avian | <zoology> Relating to, affecting, resembling or derived from a bird. (02 Jan 1998) |
| avian achondroplasia | <veterinary> An achondroplasia seen in several breeds of domestic chickens. Inheritance: autosomal dominant. (05 Mar 2000) |
| avian adenovirus type 1 proteinase | <enzyme> 206 aa residues of which 66% are homologous to human ad2 emzyme embl/genbank l13161 Registry number: EC 3.4.22.- Synonym: aavl proteinase, aavl endopeptidase (26 Jun 1999) |
| avian diphtheria | An infection by the fowlpox virus in which tracheal involvement is especially severe. See: fowlpox. Synonym: fowl diphtheria. (05 Mar 2000) |
| avian encephalomyelitis virus | <virology> A virus of the genus Enterovirus (family Picornaviridae) causing avian infectious encephalomyelitis in young chicks. (05 Mar 2000) |
| avian erythroblastosis | <veterinary> An expression of disease of the avian leukosis-sarcoma complex; characterised by severe anaemia and large numbers of erythroblasts in the blood; chickens are most susceptible but fatal natural infections have been reported in guinea fowl. Synonym: fowl erythroblastosis. (05 Mar 2000) |
| avian erythroblastosis virus | <virology> Group of C type RNA tumour viruses (Oncovirinae) that cause various leukaemias and other tumours in birds. The acute leukaemia viruses, that are replication defective and require helper viruses, include avian erythroblastosis (AEV), myeloblastosis (AMV) and myelo cytomatosis viruses. AEV carries two transforming genes, v erbA and v erbB, the cellular homologue of the latter is the structural gene for the epidermal growth factor receptor. AMV carries v myb and causes a myeloid leukaemia, avian myelocytomatosis virus carries v myc. The avian lymphatic leukaemia viruses (ALV) are also Retroviridae but are replication competent and induce neoplasia only after several months, they often occur in conjunction with replication defective leukaemia viruses. (02 Jan 1998) |