| exposure odds ratio | <epidemiology> See Odds ratio. (05 Dec 1998) |
|---|---|
| extraction ratio | The fraction of a substance removed from the blood flowing through the kidney; it is calculated from the formula (A -V)/A, where A and V, respectively, are the concentrations of the substance in arterial and renal venous plasma. (05 Mar 2000) |
| K:A ratio | <abbreviation> Ketogenic-antiketogenic ratio. (05 Mar 2000) |
| ketogenic-antiketogenic ratio | The proportion between substances that form ketones in the body and those that form d-glucose. (05 Mar 2000) |
| zeta sedimentation ratio | The ratio of the zetacrit to the haematocrit, normally 0.41 to 0.54 (41 to 54%); it is a sensitive indicator of the erythrocyte sedimentation rate (ESR) and, unlike the latter, is unaffected by anaemia, which tends to elevate the ESR. (05 Mar 2000) |
| fertility ratio | A measure of the fertility of a population based on the female population in the child-bearing age-group, defined as ages 15-49 years. (05 Mar 2000) |
| flux ratio | The ratio of the two unidirectional fluxes through a particular boundary layer or membrane. (05 Mar 2000) |
| lecithin/sphingomyelin ratio | A ratio used to determine foetal pulmonary maturity, found by testing the amniotic fluid; when the lungs are mature, lecithin exceeds sphingomyelin by 2 to 1. (05 Mar 2000) |
| functional terminal innervation ratio | The number of muscle fibres divided by the number of axons that innervate them. (05 Mar 2000) |
| low aspect ratio | <physics> An aspect ratio for a torus that is small (minor radius is almost as big as major radius). There are many fusion devices which are designed to have a low aspect ratio. Such devices look more like tractor tires than bicycle tires, as toruses go. There are reasons to believe that low aspect ratio devices will offer some advantages for a fusion reactor. Usually, ease of theoretical and/or numerical analysis is not one of these advantages. (16 Mar 1998) |
| L/S ratio | <abbreviation> Lecithin/sphingomyelin ratio. (05 Mar 2000) |