Background: Evaporation is of significant ecological interest.Evaporation from an animal always results in a decrease in the temperature of the surface from which the evaporation occurs.Therefore,evaporation is a one-...Background: Evaporation is of significant ecological interest.Evaporation from an animal always results in a decrease in the temperature of the surface from which the evaporation occurs.Therefore,evaporation is a one-way transfer which causes heat loss from the organism.Biological evaporation always involves the loss of water which is a vital resource for nearly all biochemical processes.Evaporation is loss of heat via loss of body mass.Methods: The simultaneous determination of energy expenditure and loss of body mass in resting birds allows us to estimate evaporative heat loss.This method includes direct measurements of the energetic equivalent of the loss of body mass as the ratio between heat production,determined by the rate of oxygen consumption and the loss of body mass at various ambient temperatures.Results: The data indicate that evaporation was minimal at lower critical temperature and that the rate of evaporation increased at lower or higher temperatures.Obtained results indicate that passerine and non-passerine species have the ability to change their non-evaporative heat conductance the same number of times(approximately fourfold),and that their abilities in this respect are similar.Conclusions: The novelty of the study resides in the stoichiometric approach to determination of total evaporative water loss.The analysis shows that determinations by stoichiometric approach of total evaporative water loss yielded the values,which fit into the confidence intervals of all equations from literatures.The basal metabolic rate and nonevaporative thermal conductance are fundamental parameters of energetics and determine the level of physiological organization of an endothermic animal.展开更多
The variations of muscle tissus, peroxidase and Ca2+-ATPase activities and Vp （pasteurization value） were investigated with the fresh samples of grass carp （Ctenopharyngodon idellus） heated at different temperatur...The variations of muscle tissus, peroxidase and Ca2+-ATPase activities and Vp （pasteurization value） were investigated with the fresh samples of grass carp （Ctenopharyngodon idellus） heated at different temperatures, thus revealing the mechanism of denaturation of muscle protein by heating. The experimental results showed the great difference in muscle tissue structure before and after the samples heated. In the initial stage of heating the water loss accounted for 50% of the total. When the samples were separately heated at 75, 85, and 95℃, fh values （dehydration curve slope） were 5, 4.1 and 1.7, respectively, while Vp reaching 40 minutes were 22, 8 and 5 min, respectively. As to the time for deactivation of peroxidase in the heated samples at the various temperatures, it varied from 38, 10 and to less than 6 min, respectively and the deactivation rates of Ca2+-ATPase in 1 min were 50%, 88% and 100%, respectively. Consequently, the higher temperature the sample was heated, the faster rate of thermocon ductivity, the lower rate of water loss, and the faster rate of peroxidase deactivation it was. Also, the Vp for the least requirement of pasteurization （Vp≥40min） was obtained.展开更多
基金the Russian Foundation for Basic Research for longterm support of my research (grants # 12-04-01288 and 16-04-00643)
文摘Background: Evaporation is of significant ecological interest.Evaporation from an animal always results in a decrease in the temperature of the surface from which the evaporation occurs.Therefore,evaporation is a one-way transfer which causes heat loss from the organism.Biological evaporation always involves the loss of water which is a vital resource for nearly all biochemical processes.Evaporation is loss of heat via loss of body mass.Methods: The simultaneous determination of energy expenditure and loss of body mass in resting birds allows us to estimate evaporative heat loss.This method includes direct measurements of the energetic equivalent of the loss of body mass as the ratio between heat production,determined by the rate of oxygen consumption and the loss of body mass at various ambient temperatures.Results: The data indicate that evaporation was minimal at lower critical temperature and that the rate of evaporation increased at lower or higher temperatures.Obtained results indicate that passerine and non-passerine species have the ability to change their non-evaporative heat conductance the same number of times(approximately fourfold),and that their abilities in this respect are similar.Conclusions: The novelty of the study resides in the stoichiometric approach to determination of total evaporative water loss.The analysis shows that determinations by stoichiometric approach of total evaporative water loss yielded the values,which fit into the confidence intervals of all equations from literatures.The basal metabolic rate and nonevaporative thermal conductance are fundamental parameters of energetics and determine the level of physiological organization of an endothermic animal.
文摘The variations of muscle tissus, peroxidase and Ca2+-ATPase activities and Vp （pasteurization value） were investigated with the fresh samples of grass carp （Ctenopharyngodon idellus） heated at different temperatures, thus revealing the mechanism of denaturation of muscle protein by heating. The experimental results showed the great difference in muscle tissue structure before and after the samples heated. In the initial stage of heating the water loss accounted for 50% of the total. When the samples were separately heated at 75, 85, and 95℃, fh values （dehydration curve slope） were 5, 4.1 and 1.7, respectively, while Vp reaching 40 minutes were 22, 8 and 5 min, respectively. As to the time for deactivation of peroxidase in the heated samples at the various temperatures, it varied from 38, 10 and to less than 6 min, respectively and the deactivation rates of Ca2+-ATPase in 1 min were 50%, 88% and 100%, respectively. Consequently, the higher temperature the sample was heated, the faster rate of thermocon ductivity, the lower rate of water loss, and the faster rate of peroxidase deactivation it was. Also, the Vp for the least requirement of pasteurization （Vp≥40min） was obtained.
