| light water | <radiobiology> Ordinary H2O, as opposed to heavy water, which contains atoms of the heavier isotopes of hydrogen, deuterium and/or tritium. See: hydrogen, isotope, deuterium, tritium, heavy water. (09 Oct 1997) |
|---|---|
| light-water reactor | <radiobiology> Class of fission reactors using ordinary light water as a coolant, rather than liquid metal or heavy water (water with deuterium instead of hydrogen). (09 Oct 1997) |
| light wire appliance | An orthodontic appliance utilizing small gauge labial wires with expansion and contraction loops formed into it and attached to bands fitted to individual teeth; sometimes called Begg light wire differential force technique. (05 Mar 2000) |
| abstracting and indexing | Shortening or summarizing of documents; assigning of descriptors for referencing documents. (12 Dec 1998) |
| academies and institutes | Organizations representing specialised fields which are accepted as authoritative; may be non-governmental, university or an independent research organization, e.g., national academy of sciences, brookings institution, etc. (12 Dec 1998) |
| accounts payable and receivable | Short-term debt obligations and assets occurring in the regular course of operational transactions. (12 Dec 1998) |
| aged, 80 and over | A person 80 years of age and older. (12 Dec 1998) |
| algae and fungi | Algae represent a group of spore-propagating plants, unicellular or undifferentiated into root, stem, and leaf. They include seaweed and many unicellular fresh water plants, most of which contain chlorophyll. They account for about 90% of the earth's photosynthetic activity. Fungi are eukaryotic, heterotrophic organisms that live as saprobes or parasites and include mushrooms, yeasts, smuts, molds, etc. They lack chlorophyll. (12 Dec 1998) |
| alkyl and aryl transferases | <enzyme> A somewhat heterogeneous class of enzymes that catalyze the transfer of alkyl or related groups (excluding methyl groups). Registry number: EC 2.5 (12 Dec 1998) |
| allergy and immunology | A medical specialty concerned with the hypersensitivity of the individual to foreign substances and protection from the resultant infection or disorder. (12 Dec 1998) |
| alligators and crocodiles | Large, long-tailed reptiles, including caimans, of the order loricata. (12 Dec 1998) |
| Amine Precursor Uptake and Decarboxylation | <pharmacology, physiology> Paracrine cells of which argentaffin cells are an example. Usage of the term APUD is neither helpful nor memorable. Acronym: APUD (11 Nov 1997) |
| amino acids, peptides, and proteins | Amino acids and chains of amino acids connected by peptide linkages. (12 Dec 1998) |
| Anderson and Goldberger test | A test for typhus in which the patient's blood is injected into a guinea pig's peritoneal cavity. In typhus a typical temperature curve will be observed. (05 Mar 2000) |
| anniversaries and special events | Occasions to commemorate an event or occasions designated for a specific purpose. (12 Dec 1998) |