| aseptic surgery | The performance of an operation with sterilised hands, instruments, etc., and utilizing precautions against the introduction of infectious microorganisms from without. (05 Mar 2000) |
|---|---|
| aseptic technique | <procedure> A method used by microbiologists and clinicians to keep cultures, sterile instruments and media, and people free of microbial contamination. (09 Oct 1997) |
| asepticism | The practice of aseptic surgery. (05 Mar 2000) |
| asequence | Lack of normal sequence, specifically, between atrial and ventricular contractions. (05 Mar 2000) |
| asexual | Without sex. (27 Sep 1997) |
| asexual dwarfism | Dwarfism in which adult sexual development is deficient. (05 Mar 2000) |
| asexual generation | Reproduction by fission, gemmation, or in any other way without union of the male and female cell, or conjugation. See: parthenogenesis. Synonym: heterogenesis, nonsexual generation. (05 Mar 2000) |
| asexual reproduction | <biology, microbiology> Reproduction in which an organism produces one or more clones of itself, such as by fission or budding. (09 Oct 1997) |
| ASF | <abbreviation> African swine fever. (05 Mar 2000) |
| ash | <radiobiology> Fusion reaction products trapped in a plasma. Ash is bad because (a) it generally radiates more strongly than the fuel ions, and thus reduces energy confinement, and (b) it creates additional plasma pressure and/or reduces pressure available for fuel ions. Controlling ash is a major area of fusion research. Ideally one would be able to extract the ash ions after diverting an appropriate fraction of their energy to heating the fuel ions, and then convert the remaining ash energy to electricity. Current research involves using RF waves to transfer energy from ash ions to fuel ions, and to push the ash into the scrape-off layer, where it can be collected via divertors. (09 Oct 1997) |
| ash wednesday | The first day of Lent; so called from a custom in the Roman Catholic church of putting ashes, on that day, upon the foreheads of penitents. Source: Websters Dictionary (01 Mar 1998) |
| ash-fire | A low fire used in chemical operations. Source: Websters Dictionary (01 Mar 1998) |
| Ashby | Winifred, 20th century haematologist. See: Ashby method. (05 Mar 2000) |
| Ashby method | A differential agglutination method for estimating erythrocyte life span; compatible blood possessing a group factor that the recipient lacks is transferred to the recipient; after the transfusion, sera with potent agglutinins for the recipient's red cells are added to samples of the recipient's blood, and the unagglutinated red cells are counted; using this technique the red cell life span in normal persons is found to be 110 to 120 days. (05 Mar 2000) |
| ashen | Of or pertaining to the ash tree. See: Ash, the tree. Source: Websters Dictionary (01 Mar 1998) |