The vasomotor component of the carotid sinus baroreceptor reflex in the cat during stimulation of the hypothalamic defence area.

1. The effect of moderate intensities of stimulation of the hypothalamic defence area on the baroreceptor reflex has been investigated in the cat by comparing the responses of arterial blood pressure and perfusion pressure of the isolated hind-limb muscle bed perfused at constant volume inflow, when the isolated carotid sinus was subjected to a series of non-pulsatile pressures with and without simultaneous hypothalamic stimulation.2.

Modification of the reflex response to stimulation of carotid sinus baroreceptors during and following stimulation of the hypothalamic defence area in the cat.

1. The effects of stimulation of the hypothalamic defence area on carotid sinus baroreceptor reflexes have been investigated by examining the cardiovascular responses to a 15 sec period of increased pressure within the vascularly isolated carotid sinus before, during, and immediately following a 25 sec period of hypothalamic stimulation.2.

Permeability of lung capillaries to macromolecules in foetal and new-born lambs and sheep.

1. The permeability of lung capillaries to macromolecules was investigated in immature and mature foetal lambs, new-born lambs and young sheep. The placental circulation of the foetal animals was maintained intact after delivery by Caesarian section.

Pulmonary lymph flow and the uptake of liquid from the lungs of the lamb at the start of breathing.

1. Lymph from the lungs of lambs and sheep was found to enter both the right lymph duct and the thoracic duct. Right lymph duct flow was collected by constructing a venous sac, the venous tributaries of which were ligated but which the right lymph duct entered; thoracic duct flow was collected by cannulating the duct.

Effects of gestation and prenatal asphyxia on pulmonary surface properties of the foetal rabbit.

1. The pulmonary surface properties of foetal rabbits were studied after delivery by Caesarean section at 26-30 days and after normal delivery at term (31 days).2.

The energy expenditure of coalminers at work.

This survey was intended to provide a basis of information on the energy expenditures for the main component tasks in coal-mining, carried out at different rates and in different postures. Such information is frequently required for studies of the physiological effects of coal-mining; these values reported here were required in particular for studies intended to define thermal limits of the environment suitable for miners at non-mechanized coal-faces, a situation where the metabolic heat produced makes up a large proportion of the total heat load of the individual. Regression lines have been drawn between energy expenditure and speed of shovelling for the miner working in different postures.