| BEI | back-scattered electron imaging; biological exposure indexes; butanol-extractable iodine |
|---|---|
| BEIR | biological effects of ionizing radiation |
| BFB | biological feedback; bronchial foreign body |
| BHL | bilateral hilar lymphadenopathy; biological half-life |
| BI | background interval; bacterial or bactericidal index; base-in [prism]; basilar impression; Billroth ... |
| biological clocks | The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioural phenomena in plants and animals. The pineal gland, which receives input from the optic nerves and connects to the hypothalamus, may be the biological clock in humans. (12 Dec 1998) |
|---|---|
| biological coefficient | Rarely used term denoting the energy expended by the body at rest. (05 Mar 2000) |
| biological containment | <molecular biology> Refers to any number of methods to contain genetically engineered organisms by creating biochemical barriers to prevent them from growing outside the laboratory. In the case of bacteria and yeasts, genes in the organisms may be altered so that they need to have a supply of a nutrient that is normally found only in the laboratory. (21 Mar 1998) |
| biological control | <agriculture> The agricultural use of living things, such as parasites, diseases, and predators, to control or eliminate others, such as weeds and pests, rather than by using chemicals (herbicides and pesticides). (21 Mar 1998) |
| biological dressings | Human or animal tissue used as temporary wound coverings. (12 Dec 1998) |
| biological engineering | <agriculture> A type of artificial selection, the creation of plant or animal breeds that are agriculturally or industrially useful. Compare: natural selection. (21 Mar 1998) |
| biological factors | Compounds made by living organisms. They have biological or physiological activities. (12 Dec 1998) |
| biological half-life | <biochemistry, biology> This is the time required for one-half of the total amount of a particular substance in a biological system to be consumed or broken down by biological processes when the rate of removal is approximately exponential. Toxic chemicals with a long biological half-life (such as some pesticides) will tend to accumulate in the body and are, therefore, more likely to be harmful. A substance with a short biological half-life may still accumulate if a portion of it it becomes tightly bound to bone or other tissues, even if most of it is quickly cleared from the body. (21 Mar 1998) |
| biological hazard potential | <radiobiology> Measure of the hazard posed by a given quantity of radioactive material in which the variation in biological effects of the various elements are accounted for. See: integrated biological hazard potential. (21 Mar 1998) |
| biological immunotherapy | <immunology> Treatment of disease by stimulating the bodys own immune system. This is a type of therapy currently being researched as a treatment for cancer. (16 Dec 1997) |
| biological magnification | <biology, zoology> The process by which toxins such as pesticides build up in each successive link in the food chain. For instance, a given population of beetles may have very low levels of a fat-soluble pesticide, but the pesticide will build to much greater levels in the fat of a bird that eats those beetles, and the pesticide will reach greater levels still in a human or panther that eats the beetle-eating birds. (21 Mar 1998) |
| biological markers | Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc. (12 Dec 1998) |
| biological monitoring | This is the periodic examination of biological specimens for the purposes of monitoring their exposure to or the effects of potentially toxic chemicals to the environment. This is normally done by analysing the amounts of the toxic substances or their metabolites present in body tissues and fluids. The term is also used to mean assessment of the biological status of populations and communities of organisms at risk, in order to protect them and to gain an early warning of possible hazards to human health. (09 Oct 1997) |
| biological oceanography | <study> The study of marine plants and animals and the way they interact with the marine environments. Similar to the study of marine biology. (21 Mar 1998) |
| biological oxidation | Decomposition of organic materials by microorganisms. (05 Dec 1998) |