This study characterised the pattern of oxygen consumption (VO2) in healthy infants and children asleep and awake (at rest) in a thermoneutral environment. Measurement of respiratory gas exchange (VO2 and VCO2) was made using an open circuit flow through system of indirect calorimetry with a specially designed facemask for the collection of exhaled breath. Fifty two healthy subjects aged 4.5 mo...

The effects of three stressors of different categories, namely cold exposure, immobilization, and lipopolysaccharide (LPS) treatment, on sympathetic nerve activity were examined by assessing its biochemical index norepinephrine (NE) turnover in peripheral organs of C57BL/6 mice. NE turnover was assessed by measuring the decrease in the organ NE concentration 3 h after inhibition of catecholamin...

The increase in the worldwide demand for dairy products, associated with global warming, will emphasize the issue of water use efficiency in dairy systems. The evaluation of environmental issues related to the management of animal dejections will also require precise biotechnical models that can predict effluent management in farms. In this study, equations were developed and evaluated for pred...

The production of new blood cells relies on a hierarchical network of hematopoietic stem and progenitor cells (HSPCs). To maintain lifelong hematopoiesis, HSPCs must be protected from ionizing radiation or other cytotoxic agents. For many years, murine models have been a valuable source of information regarding factors that either enhance or reduce the survival of HSPCs after exposure of marrow...

Energy expenditure in ob/ob mice kept at thermoneutrality was quantified from food intake and body composition of mice treated with leptin over 15 and 75 days, respectively. Energy expenditure in response to 15 days of treatment with leptin was twice as high as under pair-feeding conditions, indicating extensive breakdown of adipose tissue independent of a centrally mediated satiation. Leptin-i...

To clarify the role of autonomic nervous functions in cardiovascular adaptation to microgravity, heart rate variability (HRV) and blood pressure variability (BPV) were evaluated during thermoneutral head-out water immersion (HOI) of eight healthy young subjects 23 to 31 yr of age. The very low-frequency (VLF; 0.00-0.04 Hz) component of BPV tended to increase during HOI, whereas the low-frequenc...

STUDY OBJECTIVES Sleep propensity and skin temperature are functionally related. In young adults, changes of skin temperature within the comfortable thermoneutral zone affect sleep-onset latency and vigilance performance. Aging is associated with both decreased thermosensitivity and poorer sleep. Our goal was to test whether subtle manipulations of core body and skin temperature affect sleep on...

By definition, homeothermic species maintain their core temperature (Tc) regulated within narrow limits. In most of these species, the hypothalamic thermostat is set somewhere between 36 and 38 C, and Tc is tightly kept there, in spite of highly variable ambient temperatures. Several mechanisms to maintain body temperature have been selected during evolution. Vasoconstriction and piloerection a...