Birds show phylogenetic variation in the relative importance of respiratory versus cutaneous evaporation, but the consequences for heat tolerance and evaporative cooling capacity remain unclear. We measured evaporative water loss (EWL), resting metabolic rate (RMR) and body temperature (Tb) in four arid-zone columbids from southern Africa [Namaqua dove (Oena capensis, ∼37 g), laughing dove (Spi...

background: obesity and diabetes are the most important problems of public health. evidence from molecular animal research and epidemiologic investigations indicate that calcium intake may have an influence on body composition, weight and insulin resistance. the objective of this study was to determine the effects of calcium supplementation on body composition, weight, insulin resistance and bl...

We report the first empirical data describing the interactive effects of simultaneous changes in irradiance and convection on energy expenditure by live mammals. Whole-animal rates of solar heat gain and convective heat loss were measured for representatives of two ground squirrel species, Spermophilus lateralis and Spermophilus saturatus, that contrast in coloration. Radiative heat gain was qu...

heat stress particularly  at  outdoor  workplaces in hot-dry    climates can  disrupt    the physical or mental functions and effect negatively on human performance. we aimed to study the effect of heat stress on productivity loss among workers of brick workshops in qom province – central iran. this cross-sectional descriptive and analytic study was performed on 184 workers in 40 brick workshop...

background: heat stress is one of the harmful factors present in many workplaces. it can lead to performance loss and low functionality of the labor force. therefore, the aim of this study was to evaluate exposure to heat stress and its consequent performance loss among workers functioning in indoor high-temperature workplaces. materials and methods: this descriptive, analytical study was condu...

Energy metabolism is strongly linked to the circadian rhythms in sleep and body temperature. Both heat production and heat loss show a circadian modulation. Sleep preferably occurs during the circadian phase of decreased heat production and increased heat loss, the latter due to a profound increase in skin blood flow and, consequently, skin warming. The coupling of these rhythms may differ depe...

In 5 dogs which ingested 25 or 50 ml. of D20 with one daily meal, maximal plasma concentrations of tracer were reached in 12-24 hr. The disappearance rate during 14 days was exponential, confirming studies of others in humans. Water turnover, calculated from values obtained for body water and the disappearance rates, agreed well with total water intake, which included water taken as such and th...

BACKGROUND Allometric scaling, which represents the dependence of biological traits or processes on body size, is a long-standing subject in biological science. However, there has been no study to consider heat loss to the ambient and an insulation layer representing mammalian skin and fur for the derivation of the scaling law of metabolism. METHODS A simple heat transfer model is proposed to...

Skin to skin care has been practised in primitive and high technology cultures for body temperature preservation in neonates. Regional skin temperature and heat flow was measured in moderately hypothermic term neonates to quantitate the heat transfer occurring during one hour of skin to skin care. Nine healthy newborns with a mean rectal temperature of 36.3 degrees C were placed skin to skin on...