Richard J. Barnes

Learn More
The blood flow to the digestive organs of nine sheep was determined by the use of isotopically labelled microspheres before, during and at 2 h and 4 h after feeding. Within 3 min of the start of feeding, the blood flow to the salivary glands and to the smooth muscle of the rumen and reticulum increased three-fold. The blood flow to the epithelium of the(More)
Energy conservation is a key adaptation for desert survival in the Bedouin goat. When food is scarce, metabolism is reduced and body weight can be maintained indefinitely on less than one-half of normal intake. We hypothesized that metabolism would be turned down during both rest and exercise, but it was not. It was low when animals rested and returned to(More)
Insulin secretion and the factors influencing beta-cell function were investigated in the chronically catheterized fetal foal and mare during the second half of gestation. The response of the fetal beta cells to exogenous glucose was also examined. The mean concentration of insulin in the fetal foal was 7.5 +/- 0.5 (S.E.M.) microunit./ml (n = 20) which was(More)
The paper presents a systematic methodology for the optimal design and operational management of offshore oil fields. It is comprised of two tages. At the design stage, the optimal production capacity of a main field is determined with an adjacent satellite field and a well drilling schedule. he problem is formulated as a mixed-integer linear programming(More)
1. Foetal hypophysectomy or bilateral adrenalectomy, carried out in utero at about 100 or 125 days gestation respectively, increased the length of gestation in sheep. It was confirmed that pregnancy was not prolonged significantly if hypophysectomy or adrenalectomy was carried out on one of a pair of twins. The hypophysectomized foetus was, however, smaller(More)
1. The blood flow to the liver in fetuses near term, newborn and adult sheep was measured by the Fick principle, using radionuclide-labelled plastic microspheres, before and during infusion of adrenaline, noradrenaline or glucagon. 2. Glucose output and lactate consumption by the liver in sheep of each age group were calculated by application of the Fick(More)
1. The changes in liver glycogen concentration in normal, adrenalectomized and hypophysectomized foetal lambs have been examined during the last third of gestation using a biopsy technique to remove one or more samples of liver from the same foetus at different gestational ages. 2. The rate of glycogen deposition increased sharply from about 130 days'(More)
Normal Thoroughbred and catheterized Pony mares and their fetuses were used. Fetal oestrogen and progestagen concentrations in late gestation were much higher than maternal values. A major feature of the umbilical steroid concentrations was a large venous-arterial difference in progestagens and total oestrogens throughout late gestation which may indicate a(More)
1. The changes in cardiac output and mean right atrial pressure (R.A.P.) evoked by stimulation of the cardiac autonomic nerves were investigated in cats under chloralose anaesthesia, with unopened chests and spontaneous respiration, and with active vascular reflexes. Cardiac output was measured by thermal dilution; the technique used was calibrated against(More)