[Gynecology and aircraft piloting aptitude].

The consequences of gynecological disorders and pregnancy are reviewed, as well as the impact of the stresses of aerospace on female and feto-maternal physiology. Current regulations leave the physician a high degree of discretion. Most of the restrictions on employment which do exist are not due to gynecological reasons.

Circadian variations of systolic time intervals.

In order to test the reality of a circadian evolution of systolic time intervals, an experiment was conducted on six subjects resting in a supine position for 24 h. Heart rate (HR), systole (S), diastole (D), presystole (PS), isovolumetric contraction time (IVCT), normal and corrected ventricular pre-ejection and ejection time (LPEP, LPEPc, LVET, LVETc) were computed by electric rheoplethysmography every 3 h in supine and sitting positions. Evidence of the existence of a circadian rhythm was clear in supine subjects; especially LPEP and LVET acrophases were, respectively, 4.

Circadian rhythm of thermoregulating responses in man exposed to thermal stimuli.

Circadian changes in man's thermoregulating responses were studied in two experimental runs during which 7 volunteer subjects were exposed at 8 equally spaced time points of the 24-h span to a quick rise in temperature (To = 40 degrees C, v = 1 m/sec, P H2O less than 1 kPa) or to progressive cooling, the final temperature being reached after 45 min (To = 20 degrees C, v = 0.2 m/sec, P H2O less than 1 kPa). Under heat exposure, a circadian rhythm was observed in the period preceding the onset of sweating, and also in rectal temperature and mean body temperature, both at the onset of sweating and at its steady state.

The application of variance analysis to the study of biological rhythms of known periods.

This paper describes a statistical technique which permits study of, for example, complex biological rhythms with a known fundamental period. This technique uses the principles of variance analysis. The main calculation phases are: the regression calculation on a periodic time function; the study (by variance analysis) of the validity of the mathematical model; the study of the parallelism between subjects; and, finally, the study of the significance of each harmonic component.

Measurement of systolic time intervals by electrical plethysmography: validation with invasive and noninvasive methods.

An experiment was conducted to validate the use of electrical impedance plethysmography for measuring systolic time intervals. This method is of interest in aerospace medicine since it is a noninvasive technique and very easy to use without causing discomfort to the subject. The equipment, with electrodes placed in front of the heart, gave both the first derivative of the electrical impedance variation and the E.

[Airports malaria: findings of a survey in Paris airports (author's transl)].

From 1976 to 1978, thirteen cases of malaria have been reported from France. Ten of them occurred in the vicinity of the airport Roissy-Charles de Gaulle. The entomological investigation which is described there have been performed to evaluate risk of local transmission and to plan prophylactic measures.

Circadian rhythm of temperature in man. Comparative study with two experiment protocols.

The circadian rhythm of rectal and skin temperature was studied in man at rest and at thermal neutrality according to two different protocols, to make allowance for the experimental conditions. In the first case, ambient temperature (To) was maintained at a constant value close to thermal neutrality and mean skin temperature (Ts) could evolve freely for 24 h. In the second case, Ts was maintained at 34 degrees C by adequately adjusting To during 90 min-periods divided into 8 equidistant points of the 24-h spans.

[Comparison of the sweating rate under thermal constraint equivalent at rest and during exercise].

Subjects exposed to tolerable thermal constraints of equal intensity at rest and during exercise start sweating at lower mean body temperatures during exercise and the sweating rate increases faster during exercise than at rest.

Experimental study of convective heat transfer coefficient for the human body in water.

The steady-state convective heat transfer coefficient in water has been determined by partitional calorimetry for 17 nude subjects. Four water velocities were investigated: 0, 0.05, 0.

Comparison of shivering in man exposed to cold in water and in air.

Metabolic rate (M), mean skin temperature (Tsk) and rectal temperature (Tre) were studied during 2 h exposure to cold in the air (Ta = 15-25 degrees C) and in water (TH2O = 24-32 degrees C). From the results, it was possible to draw tentative equations of the metabolic response in transient and steady state as functions of body temperatures: Mair = 41,3-57.77 dTsk/dt-5.

Mathematical model of man's tolerance to cold using morphological factors.

A mathematical model has been developed to anticipate the physiological responses and the thermal state of a naked human under exposure to cold, taking into account his morphological characteristics (skinfold, size, weight) and the environmental conditions (air or water temperature and velocity, barometric pressure and hygrometry). The skinfold conditions the body's thermal conductance and the metabolism depends both on rectal (Tre) and mean skin (Tsk) temperatures. After being tested, this model was used to study the evolution of Tre.

Circadian variations in the sweating mechanism.

Sweat rates and body temperatures of human subjects were measured at 0200, 1000, and 1800 h during a heat exposure of 90 min. The latent period of sweating was not significantly altered in the evening but significantly shortened during the night. Mean body temperature corresponding to the onset of sweating was nearer to the basal body temperature during the night, while during the day the difference between these two temperatures became larger.

[A model of sweating during muscular exercise].

From a practical viewpoint, thermal sweating during exercise can be described by an exponential equation. The errors from this mathematical model are of few importance. Nevertheless, metrologic and physiological factors can complicate theoretically the model.