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Biomedical subjects

T Richards

Publications and source records attributed to T Richards.

At least 127 records · Page 7Linked to original sources
PubMed1985

Calculation of age-specific fertility schedules from tabulations of parity in two censuses.

The mathematics of stable populations recently has been generalized to cover populations with time-varying fertility and mortality by a modification incorporating the sum of age-varying growth rates in place of the fixed growth rate of a stable population. Equations that characterize nonstable populations apply to any cohort-like phenomenon with a measurable property that cumulates gains or losses through time. In particular, the equations fit the relation between a population's average parity at a given age and age-specific fertility rates previously experienced at lower ages. Techniques devised to derive an intercensal life table from single-year age distributions in two censuses are adapted to estimate accurate intercensal fertility schedules from distributions of parity by age of woman in two censuses. Birth-order specific fertility schedules are also estimated.

Adolescent↗
PubMed1983

Farr sighted.

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Cholera↗
PubMed1983

Weather, nutrition, and the economy: short-run fluctuations in births, deaths, and marriages, France 1740-1909.

This paper analyzes short-run fluctuations in national time series of vital events for France in the period 1740 to 1909. Fertility, mortality, and nuptiality form a simultaneous system which interacts with economic and meteorological conditions. In the short run, the demographic variables are endogenous. Economic and meteorological conditions are exogenous. Our indicator of economic conditions is the price of wheat, the principal food crop. Biometric models of fertility and empirical research on the biologically-based interrelations of fertility and mortality provide insight into the expected timing of events. We combine these results with empirical research on the effects of nutrition on fertility and mortality, research in medical biometeorology, and French historical demographic and economic research to formulate our model. The resultant distributed lag system is estimated. We find that the economic/nutritional effects are more likely to be statistically significant in predicting the time path of vital events than are the demographic variables or the effects of meteorological conditions.

Birth Rate↗
PubMed1982

Malocclusion in inbred strain-2 weanling guineapigs.

The incidence of malocclusion was recorded for 4 years. Malocclusion occurred only in animals less than 2 months old. The incidence was significantly reduced (P greater than 0.001) by breeding from animals without affected siblings: it is suggested that malocclusion in this colony has a genetic basis.

Age Factors↗