| LDA | laser Doppler anemometry; left dorso-anterior [fetal position]; linear discriminant analysis; lympho... |
|---|---|
| LET | lidocaine, epinephrine, and tetracaine [solution]; linear or low energy transfer |
| LFER | linear free-energy relationship |
| LFx | linear fracture |
| LINAC | linear accelerator |
| biological coefficient | Rarely used term denoting the energy expended by the body at rest. (05 Mar 2000) |
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| Bunsen's solubility coefficient | The milliliters of gas STPD dissolved per milliliter of liquid and per atmosphere (760 mm Hg) partial pressure of the gas at any given temperature. (05 Mar 2000) |
| velocity coefficient | The rate of transformation of a unit mass of substance in a chemical reaction. (05 Mar 2000) |
| recombination coefficient | <radiobiology> The rate of recombination of positive ions with electrons (or negative ions) in a gas, per unit volume, divided by the product of the particle densities of the two species (positive ions and electrons/negative ions) involved. (09 Oct 1997) |
| mass attenuation coefficient | <physics> The mass attenuation coefficient, u/p, of a material for uncharged ionising particles is the quotient of DN/N by pdl, where DN/N is the fraction of particles that experience interactions in traversing a distance dl in a material of density p. (16 Dec 1997) |
| reflection coefficient | A measure of the relative permeability of a particular membrane to a particular solute; calculated as the ratio of observed osmotic pressure to that calculated from van't Hoff's law; also equal to 1 minus the ratio of the effective pore areas available to solute and to solvent. (05 Mar 2000) |
| partition coefficient | <chemistry> Equilibrium constant for the partitioning of a molecule between hydrophobic (oil) and hydrophilic (water) phases. A measure of the affinity of the molecule for hydrophobic environments and thus, for example: a rough guide to the ease with which a molecule will cross the plasma membrane. (18 Nov 1997) |
| reliability coefficient | An index of the consistency of measurement often based on the correlation between scores obtained on the initial test and a retest (test-retest reliability) or between scores on two similar forms of the same test (equivalent-form reliability). (05 Mar 2000) |
| respiratory coefficient | <physiology> Molar ratio of carbon dioxide production to oxygen consumption. (18 Nov 1997) |
| Rideal-Walker coefficient | A figure expressing the disinfecting power of any substance; it is obtained by dividing the figure indicating the degree of dilution of the disinfectant that kills a microorganism in a given time by that indicating the degree of dilution of phenol which kills the organism in the same space of time under similar conditions. Synonym: hygienic laboratory coefficient, phenol coefficient. (05 Mar 2000) |
| permeability coefficient | A coefficient associated with simple diffusion through a membrane that is proportional to the partition coefficient and the diffusion coefficient and inversely proportional to membrane thickness. (05 Mar 2000) |
| phenol coefficient | A figure expressing the disinfecting power of any substance; it is obtained by dividing the figure indicating the degree of dilution of the disinfectant that kills a microorganism in a given time by that indicating the degree of dilution of phenol which kills the organism in the same space of time under similar conditions. Synonym: hygienic laboratory coefficient, phenol coefficient. (05 Mar 2000) |
| molar extinction coefficient | Absorbance (of light) per unit path length (usually the centimeter) and per unit of concentration (moles per liter); a fundamental unit in spectrophotometry. Synonym: absorbancy index, absorptivity, molar absorbancy index, molar absorptivity, molar extinction coefficient. (05 Mar 2000) |
| coefficient | 1. The expression of the amount or degree of any quality possessed by a substance, or of the degree of physical or chemical change normally occurring in that substance under stated conditions. 2. The ratio or factor that relates a quantity observed under one set of conditions to that observed under standard conditions, usually when all variables are either 1 or a simple power of 10. Origin: L. Co-+ efficio (exfacio), to accomplish (05 Mar 2000) |
| coefficient of consanguinity | A statistical way of gauging how close two people are as to the genes. The coefficient of inbreeding (symbolised as F) is the probability that a person with two identical genes received both genes from an identical ancestor. Take first cousins who by definition share a set of grandparents. So for any particular allele (gene) in the father, the chance that the mother inherited the same allele from the same source is 1/8. Further, for any gene the father passes to his child, the chance is 1/8 that the mother has the same gene and 1/2 that she transmits that gene to the child so 1/8 X 1/2 = 1/16. Thus, a first-cousin marriage has a coefficient of inbreeding F =1/16. The added risks to the offspring of first cousins depend not only upon this coefficient of inbreeding but also upon the genetic family history and, in some cases, upon test results (for example, for beta thalassaemia for first cousins of Italian descent). However, there are always added risks from the mating of closely related persons and those risks are not negligible. (12 Dec 1998) |