Thermogen

To summarize, bacterial sulfate reduction is characterized by large and heterogeneous " S-depletions over very small spatial scales, whereas thermogenic sulfate reduction leads to smaller and more homogeneous " S-depletions. 

Of special interest in recent years has been the analysis of natural gas hydrates that form in marine sediments and polar rocks when saline pore waters are saturated with gas at high pressure and low temperature. Large and 5D-variations of hydrate bound methane, summarized by Kvenvolden (1995) and Milkov (2005), suggest that gas hydrates represent complex mixtures of gases of both microbial and thermogenic origin. The proportions of both gas types can vary significantly even between proximal sites. 

Thermogenic gas is produced when organic matter is deeply buried and - as a consequence - temperature rises. Thereby, increasing temperatures modify the organic matter due to various chemical reactions, such as cracking and hydrogen diproportionation in the kerogen. bonds are preferentially broken... 

Sherwood-Lollar et al. 1993,2002). In contrast to thermogenic hydrocarbons where higher hydrocarbons (ethane, propane, butane) are enriched in and D relative to methane, abiogenic alkanes may be depleted in C and D relative to methane. These depletion patterns relative to methane may be produced by polymerization reactions of methane precursors (Sherwood-Lollar et al. 2002). 

The hypothalamic temperature controller (Bl) can be inactivated by neuroleptics (p. 236), without impairment of other centers. Thus, it is possible to lower a patient s body temperature without activating counter-regulatory mechanisms (thermogenic shivering). This can be exploited in the treatment of severe febrile states (hyperpyrexia) or in open-chest surgery with cardiac by-pass, during which blood temperature is lowered to 10°C by means of a heart-lung machine. 

Thermogenic activity. Chloroform extract of the dried rhizome, at concentrations of 5 and 50 p-g/mL administered by perfusion to the hind limb of rats, stimulated oxygen uptake ° . 

Clark. Pungent principles of ginger Z0139 (Zingiber officinale) are thermogenic in the perfused rat hindlimb. Int J Obesity 1992 16 755-763. 

Thermogenic. Producing heat. Thrombocytosis. Increased numbers of platelets in the peripheral blood. 

Meeuse, B. J.D. and Raskin, I. (1988). Sexual reproduction in the arum lily family, with emphasis on thermogenicity. Sexual Plant Reproduction 1 3-15. 

Seymour, R. S. and Schultze-Motel, P. (1999). Respiration, temperature regulation and energetics of thermogenic inflorescences of the dragon lily Dracunculus vulgaris (Araceae). Proceedings of the Royal Society of London, Series 266 1975-1983. 

Thyroid hormones are intimately involved in regulating the basal metabolic rate. Liver tissue of animals given excess thyroxine shows an increased rate of 02 consumption and increased heat output (thermogenesis), but the ATP concentration in the tissue is normal. Different explanations have been offered for the thermogenic effect of thyroxine. One is that excess thryroxine causes uncoupling of oxidative phosphorylation in mitochondria. How could such an effect account for the observations Another explanation suggests that the thermogenesis is due to an increased rate of ATP utilization by the thyroxine-stimulated tissue. Is this a reasonable explanation Why ... 

Thermodynamics and Reverse Electron Flow Thermogenic Tissues... 

BOX 18-C USING METABOLISM TO GENERATE HEAT THERMOGENIC TISSUES... 

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