| T2 | transverse relaxation time |
|---|---|
| T2 | diiodothyronine; spin-spin or transverse relaxation time |
| T2* | effective transverse relaxation time |
| T2* | effective transverse relaxation time |
| t | Greek lower case letter tau; life [of radioisotope]; relaxation time; shear stress; spectral transmi... |
| mortality rate, infant | The number of children dying under a year of age divided by the number of live births that year. The infant mortality rate in the united states, which was 12.5 per 1,000 live births in 1980, fell to 9.2 per 1,000 live births in 1990. (12 Dec 1998) |
|---|---|
| mortality rate, maternal | The number of maternal deaths related to childbearing divided by the number of live births (or by the number of live births + foetal deaths) in that year. The maternal mortality rate in the united states in 1993 (and 1994) was 0.1 per 1,000 live births, or 1 mother dying per 10,000 live births. (12 Dec 1998) |
| mortality rate, neonatal | The number of children dying under 28 days of age divided by the number of live births that year. The neonatal mortality rate in the united states, which was 8.4 per 1,000 live births in 1980, declined to 5.8 per 1,000 live births in 1990. (12 Dec 1998) |
| concordance rate | The proportion of a random sample of pairs that are concordant for a trait of interest. A high rate of concordance may be generated in several ways, many of which may result from irrelevant bias; but broadly it is taken as evidence of causal connection (e.g., in the case of identical twins, a genetic component or in spouses of assortative mating). (05 Mar 2000) |
| contact rate | <epidemiology> The rate at which susceptibles meet infecteds. Usually measured as individuals per unit time. (05 Dec 1998) |
| mutation rate | The frequency with which a particular mutation appears in a population or the frequency with which any mutation appears in the whole genome of a population. Normally the context makes the precise use clear. See: fluctuation analysis. (18 Nov 1997) |
| critical rate | A heart rate at which aberration or incomplete block will occur; a result of shortening of cycle length so that it barely includes the refractory period. (05 Mar 2000) |
| crude birth rate | <epidemiology> The number of live births in a year divided by the population size. (05 Dec 1998) |
| crude death rate | <epidemiology> The number of deaths in a year divided by the population size. (05 Dec 1998) |
| pregnancy rate | Ratio of the number of conceptions that occur during a period to the mean number of women of reproductive age. (12 Dec 1998) |
| hazard rate | <statistics> Theoretical measure of the risk of occurrence of an event, e.g., death, new disease, at a point in time. (05 Mar 2000) |
| heart rate | The number of beats per minute. Normal resting heart rates are variable with age, sex, size and overall cardiovascular condition. Heart rate can be determined by taking the pulse. Normal heart rate for an average sized adult is in the range of 60-85 beats/minute. (27 Sep 1997) |
| heart rate, foetal | The heart rate of the foetus. The normal range at term is between 120 and 160 beats per minute. (12 Dec 1998) |
| heat rate | The amount of fuel energy required by a power plant to produce one kilowatt-hour of electrical output. A measure of generating station thermal efficiency, generally expressed in Btu per net kWh. It is computed by dividing the total Btu content of fuel burned for electric generation by the resulting net kWh generation. (05 Dec 1998) |
| scan rate | <microscopy> The number of horizontal-scan lines per frame and vertical scans per second that are repeated in video, for example, 525/60, 625/50. In 525/60, 2: 1 interlaced video, the V scan is repeated at the field rate (which is half of the frame rate for 2: 1 interlaced video) so that 525 H scans take place 30 times a second. The H-scan rate is therefore 525 x 30 = 15.75 kHz. With 525/60, 1: 1 interlace, the H-scan rate would be twice this value. (05 Aug 1998) |