This work falls within the context of reducing energy consumption in Côte d’Ivoire. As the building sector is one of the energy consumers worldwide, it could be a major source of energy savings. A major source o...This work falls within the context of reducing energy consumption in Côte d’Ivoire. As the building sector is one of the energy consumers worldwide, it could be a major source of energy savings. A major source of energy savings. With this in mind thermal comfort in buildings in Côte d’Ivoire (Abidjan) in order to determine (Abidjan) to determine thermal comfort conditions. To carry out study, measurement campaigns were carried out in various buildings. These measured parameters were used to calculate comfort indices such as PMV, PDD, SET and operating temperature. A correlation was then made between the PMV index and the operating temperature, then between the SET and the operating temperature to determine the thermoneutrality temperature and the different thermal comfort thermal comfort ranges. The PMV gave a thermoneutrality temperature of 24.87˚C in the rainy season and a thermoneutrality temperature of 25.15˚C during the dry season. In addition, the SET gave comfort ranges, with values ranging from 23.23˚C to 25.70˚C in the rainy season and 23.35˚C to 26.08˚C in the dry season. In addition, the acceptability predicted by the PDD showed that in the rainy season, the premises were more acceptable than in the dry season.展开更多
Mongolian gerbils(Meriones unguiculatus)have evolved a wide thermoneutral zone(26.5-38.9°C)and high upper critical temperature,and appear to have a high tolerance for heat exposure.Here,we use a metabolomic...Mongolian gerbils(Meriones unguiculatus)have evolved a wide thermoneutral zone(26.5-38.9°C)and high upper critical temperature,and appear to have a high tolerance for heat exposure.Here,we use a metabolomic approach to measure global metabolite profiles for gerbils between lower(27°C)and upper critical temperatures(38°C)to investigate the role of metabolomic characterization in maintaining basal metabolic rates within a wide thermoneutral zone.We found that in serum and liver,14 and 19 metabolites were significantly altered,respectively.In the aerobic respiration-related tricarboxylic cycle(TCA),5 intermediates(isocitric acid,cis-aconitic acid,α-ketoglutaric acid,fumaric acid and malic acid)were increased in serum in 38°C animals;however,no such increase was found in the liver.A stable level of hepatic TCA cycle intermediates may be related to the steady state of aerobic respiration at 38°C.Metabolomic results also revealed that acute heat exposure caused increased oxidative stress and low molecular weight antioxidants in Mongolian gerbils.Increased methionine and 2-hydroxybutyrate suggest an accelerated synthesis of glutathione.Increased urate and its precursors,inosine and hypoxanthine,were detected at 38°C.Glucuronate,threonate and oxalate involved in ascorbate synthesis and degradation were increased in serum at 38°C.In conclusion,although dramatic metabolomic variation was found,a stable hepatic TCA cycle may contribute to maintaining a constant basal metabolic rate within a wide thermoneutral zone in Mongolian gerbils.展开更多
The thermoneutral zone(TNZ)reflects the adaptation of mammals to their natural habitat.However,it remains unclear how TNZ shifts in response to variations in ambient temperature.To test the hypothesis that ambient temp...The thermoneutral zone(TNZ)reflects the adaptation of mammals to their natural habitat.However,it remains unclear how TNZ shifts in response to variations in ambient temperature.To test the hypothesis that ambient temperature plays a key role in determining TNZ variations between seasons,we measured metabolic rate,body temperature,and cytochrome c oxidase(COX)activity of several visceral organs in striped hamsters(Cricetulus barabensis)either acclimated to semi-natural conditions over a year,or subjected to a gradual decrease in mean temperature from 30±1°C to-15±1°C.The TNZ range in striped hamsters differed seasonally,with a wider TNZ and a lower lower-critical temperature in winter compared to summer.The hamsters showed a consider-able leftward shift of lower-critical temperature from 30°C to 20°C after the ambient temperature of acclimation from 30°C down to-15°C,whereas the upper-critical temperature of TNZ remainedfixed at 32.5°C.The rest-ing metabolic rate in thermoneutral zone(RMRt),nonshivering thermogenesis(NST),and COX activity of brown adipose tissue,liver,skeletal muscle,brain,and kidneys,increased significantly in hamsters acclimated at lower ambient temperatures.Following acute exposure to 5°C and-15°C,hamsters acclimated to 32.5°C had signifi-cantly lower maximal NST and lower serum thyroid tri-iodothyronine(T3)levels compared to those kept at 23°C.Thesefindings suggest that acclimation to the upper-critical temperature of TNZ impairs the hamsters’thermo-genic capacity to cope with extreme cold temperature.Reduced ambient temperature was mainly responsible for the leftward shift of TNZ in striped hamsters,which reflects the adaptation to cold environments.展开更多
文摘This work falls within the context of reducing energy consumption in Côte d’Ivoire. As the building sector is one of the energy consumers worldwide, it could be a major source of energy savings. A major source of energy savings. With this in mind thermal comfort in buildings in Côte d’Ivoire (Abidjan) in order to determine (Abidjan) to determine thermal comfort conditions. To carry out study, measurement campaigns were carried out in various buildings. These measured parameters were used to calculate comfort indices such as PMV, PDD, SET and operating temperature. A correlation was then made between the PMV index and the operating temperature, then between the SET and the operating temperature to determine the thermoneutrality temperature and the different thermal comfort thermal comfort ranges. The PMV gave a thermoneutrality temperature of 24.87˚C in the rainy season and a thermoneutrality temperature of 25.15˚C during the dry season. In addition, the SET gave comfort ranges, with values ranging from 23.23˚C to 25.70˚C in the rainy season and 23.35˚C to 26.08˚C in the dry season. In addition, the acceptability predicted by the PDD showed that in the rainy season, the premises were more acceptable than in the dry season.
基金supported by the National Natural Scientific Foundation of China(31472006 and 31272312)to DHW.
文摘Mongolian gerbils(Meriones unguiculatus)have evolved a wide thermoneutral zone(26.5-38.9°C)and high upper critical temperature,and appear to have a high tolerance for heat exposure.Here,we use a metabolomic approach to measure global metabolite profiles for gerbils between lower(27°C)and upper critical temperatures(38°C)to investigate the role of metabolomic characterization in maintaining basal metabolic rates within a wide thermoneutral zone.We found that in serum and liver,14 and 19 metabolites were significantly altered,respectively.In the aerobic respiration-related tricarboxylic cycle(TCA),5 intermediates(isocitric acid,cis-aconitic acid,α-ketoglutaric acid,fumaric acid and malic acid)were increased in serum in 38°C animals;however,no such increase was found in the liver.A stable level of hepatic TCA cycle intermediates may be related to the steady state of aerobic respiration at 38°C.Metabolomic results also revealed that acute heat exposure caused increased oxidative stress and low molecular weight antioxidants in Mongolian gerbils.Increased methionine and 2-hydroxybutyrate suggest an accelerated synthesis of glutathione.Increased urate and its precursors,inosine and hypoxanthine,were detected at 38°C.Glucuronate,threonate and oxalate involved in ascorbate synthesis and degradation were increased in serum at 38°C.In conclusion,although dramatic metabolomic variation was found,a stable hepatic TCA cycle may contribute to maintaining a constant basal metabolic rate within a wide thermoneutral zone in Mongolian gerbils.
基金supported by grants from National Natural Science Foundation of China(Nos.31670417,31870388).
文摘The thermoneutral zone(TNZ)reflects the adaptation of mammals to their natural habitat.However,it remains unclear how TNZ shifts in response to variations in ambient temperature.To test the hypothesis that ambient temperature plays a key role in determining TNZ variations between seasons,we measured metabolic rate,body temperature,and cytochrome c oxidase(COX)activity of several visceral organs in striped hamsters(Cricetulus barabensis)either acclimated to semi-natural conditions over a year,or subjected to a gradual decrease in mean temperature from 30±1°C to-15±1°C.The TNZ range in striped hamsters differed seasonally,with a wider TNZ and a lower lower-critical temperature in winter compared to summer.The hamsters showed a consider-able leftward shift of lower-critical temperature from 30°C to 20°C after the ambient temperature of acclimation from 30°C down to-15°C,whereas the upper-critical temperature of TNZ remainedfixed at 32.5°C.The rest-ing metabolic rate in thermoneutral zone(RMRt),nonshivering thermogenesis(NST),and COX activity of brown adipose tissue,liver,skeletal muscle,brain,and kidneys,increased significantly in hamsters acclimated at lower ambient temperatures.Following acute exposure to 5°C and-15°C,hamsters acclimated to 32.5°C had signifi-cantly lower maximal NST and lower serum thyroid tri-iodothyronine(T3)levels compared to those kept at 23°C.Thesefindings suggest that acclimation to the upper-critical temperature of TNZ impairs the hamsters’thermo-genic capacity to cope with extreme cold temperature.Reduced ambient temperature was mainly responsible for the leftward shift of TNZ in striped hamsters,which reflects the adaptation to cold environments.
