Eight different asymptotic models, of which some are entirely new while others are revised versions, are compared with respect to their goodness of fit for the description of the longitudinal growth of stature in 27 healthy children from the French Auxological Survey. Some growth models are based on total age, defined as measured from the time of fertilization, and may be particularly suitable if prenatal data are to be included in the analysis or if prenatal extrapolations are desired. Other models are based on postnatal age (age after birth), and some of these are the most accurate, but they would not be suitable for prenatal data or extrapolations. More general models, such as the polynomial logistic or the triple logistic, can be used but are not the most accurate among those included in the present study. Two new models are proposed which possess an improved goodness of fit. © 1992 Wiley-Liss, Inc.

A new seven-parameter asymptotic growth curve has been applied to longitudinal data on the height of 13 boys and 14 girls from 1 month to 19 years of age. The residual sums of squares with this new curve were 7.5 times lower on the average than with the currently-used five-parameter curve No. 1 of Preece and Baines (1978, Annals of Human Biology 5, 1-24) and 2.4 times lower than with the recent six-parameter curve of Shohoji and Sasaki (1987, Growth 51, 432-450). The new curve is expressed with respect to total age, passes through the origin, and fits infants as satisfactorily as older children.

There appears to be a reduction in endothelium-dependent and endothelium-independent, macro- and microvascular function associated with diving. Our results suggest that in the process of vascular dysfunction during diving, functional changes in the vessel wall may not be limited to the endothelium and may be mediated by alterations in vascular smooth muscle.

Pre-dive oral hydration decreases circulatory bubbles, thus offering a relatively easy means of reducing decompression sickness risk. The prehydration condition allowed attenuation of dehydration and prevention of hypovolaemia induced by the diving session. Hydration and diving did not change plasma surface tension in this study.

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