Background: The temperature preferences of cold-blooded animals are different for different groups of animals and are closely related to their evolutionary status and level of adaptive capabilities. The range of prefe...Background: The temperature preferences of cold-blooded animals are different for different groups of animals and are closely related to their evolutionary status and level of adaptive capabilities. The range of preferred temperatures for reptiles (28°C - 32°C) coincides with the zone of temperature-dependent increase in the rate of the M-cholinergic reaction in the brain, which was previously found in warm-blooded neurons. The growth of the M-cholinergic process contributes to the transition of adaptive behavior to a higher level. Of the cold-blooded, only reptiles actively use thermoregulatory behavior as a tool to achieve a temperature optimum. This paper is devoted to the study of the behavior of red-eared turtles aimed at reaching the range of preferred temperatures. Temperature conditions necessary for the survival of different groups of cold-blooded animals are compared and the reason for temperature preferences is discussed. Methods: The behavior of turtles was studied under conditions of variable solar radiation and in a 3-section terrarium with gradual temperature ranges: 23°C - 24°C;28°C - 31°C and 45°C - 50°C. Results: It was found that prolonged (up to 1.5 hours) heating at a temperature of 45°C - 50°C was the best way to achieve the preferred temperatures. This method of heating results in increasing the temperature of the shell to an average of 37°C, followed by a very slow decrease during 4 - 6 hours within the limits that closely coincided with the preferred level. Conclusion: The results obtained demonstrate that the main function of the turtle shell is to accumulate heat and keep it for a long time in a variable climate. The preferred temperature achieved in this case is necessary for the temperature-dependent transition of the rate of the M-cholinergic reaction in the brain to a higher level, which creates more significant adaptive capabilities. The temperature range of the M-cholinergic process has two inflection points at 27°C - 29°C and 34°C - 36°C. In accordance with these values, the temperature preferences of cold-blooded animals are divided into three groups: 0°C - 28°C (fish and amphibians);28°C - 32°C (reptiles) and 34°C - 36°C (dinosaurs). Different ranges of preferred temperatures correspond to three stages of adaptive development.展开更多
Rare earth elements of the zircons from the Mesozoic volcanic rocks in Luanping region, Hebei, were analyzed the results reflect that the average values of δEu and （Lu/Gd）N are 0.49 and 21.8 respectively in the zir...Rare earth elements of the zircons from the Mesozoic volcanic rocks in Luanping region, Hebei, were analyzed the results reflect that the average values of δEu and （Lu/Gd）N are 0.49 and 21.8 respectively in the zircons from the top part of Tiaojishan Formation; but the average values of δEu and （Lu/Gd）N are 0.15, 0.06, 0.09 and 14.51, 15.66, 16.25 respectively in the zircons from the lower, and upper part of the Tuchengzi Formation and the bottom bed of the Zhangjiakou Formation. The results show that the characteristics of the zircons from the Tuchengzi Formation are coincident with those of the zircons from the Zhangjiakou Formation, but are different from those of the zircons from the Tiaojishan Formation, and imply that the Tuchengzi Formation has close relation with the Zhangjiakou Formation. Combining the results above with the former isotopic dating results of the volcanic rocks, the authors draw the conclusions as follows ： The Tuchengzi Formation not only has a long interval period with the Tiaojishan Formation, but also is very different from the Tiaojishan Formation in zircon geochemical characteristics. The Zhangjiakou Formation in time, but also is coincident with the Tuchengzi Formation not only is nearly continuous with the Zhangjiakou Formation in geochemistry of zircons. The resuhs imply that the Tuchengzi Formation and the Zhangjiakou Formation were formed in the same geological background, that is, there are not the boundary of the J3-K1 and the interface of the transition of tectonic framework between the Tuchengzi Formation and the Zhangjiakou Formation in the Luanping region. The research shows that the （Lu/Gd）N, δEu are two important parameters which are relatively stable in the analysis of zircons from Crust-source; but the values of ∑LREE of zircons from Crust-source change greatly, especially the abundance of La element, so some ratios of rare earth elements related with La （or ∑LREE） are not usable in determining the characteristics of zircons.展开更多
文摘Background: The temperature preferences of cold-blooded animals are different for different groups of animals and are closely related to their evolutionary status and level of adaptive capabilities. The range of preferred temperatures for reptiles (28°C - 32°C) coincides with the zone of temperature-dependent increase in the rate of the M-cholinergic reaction in the brain, which was previously found in warm-blooded neurons. The growth of the M-cholinergic process contributes to the transition of adaptive behavior to a higher level. Of the cold-blooded, only reptiles actively use thermoregulatory behavior as a tool to achieve a temperature optimum. This paper is devoted to the study of the behavior of red-eared turtles aimed at reaching the range of preferred temperatures. Temperature conditions necessary for the survival of different groups of cold-blooded animals are compared and the reason for temperature preferences is discussed. Methods: The behavior of turtles was studied under conditions of variable solar radiation and in a 3-section terrarium with gradual temperature ranges: 23°C - 24°C;28°C - 31°C and 45°C - 50°C. Results: It was found that prolonged (up to 1.5 hours) heating at a temperature of 45°C - 50°C was the best way to achieve the preferred temperatures. This method of heating results in increasing the temperature of the shell to an average of 37°C, followed by a very slow decrease during 4 - 6 hours within the limits that closely coincided with the preferred level. Conclusion: The results obtained demonstrate that the main function of the turtle shell is to accumulate heat and keep it for a long time in a variable climate. The preferred temperature achieved in this case is necessary for the temperature-dependent transition of the rate of the M-cholinergic reaction in the brain to a higher level, which creates more significant adaptive capabilities. The temperature range of the M-cholinergic process has two inflection points at 27°C - 29°C and 34°C - 36°C. In accordance with these values, the temperature preferences of cold-blooded animals are divided into three groups: 0°C - 28°C (fish and amphibians);28°C - 32°C (reptiles) and 34°C - 36°C (dinosaurs). Different ranges of preferred temperatures correspond to three stages of adaptive development.
文摘Rare earth elements of the zircons from the Mesozoic volcanic rocks in Luanping region, Hebei, were analyzed the results reflect that the average values of δEu and （Lu/Gd）N are 0.49 and 21.8 respectively in the zircons from the top part of Tiaojishan Formation; but the average values of δEu and （Lu/Gd）N are 0.15, 0.06, 0.09 and 14.51, 15.66, 16.25 respectively in the zircons from the lower, and upper part of the Tuchengzi Formation and the bottom bed of the Zhangjiakou Formation. The results show that the characteristics of the zircons from the Tuchengzi Formation are coincident with those of the zircons from the Zhangjiakou Formation, but are different from those of the zircons from the Tiaojishan Formation, and imply that the Tuchengzi Formation has close relation with the Zhangjiakou Formation. Combining the results above with the former isotopic dating results of the volcanic rocks, the authors draw the conclusions as follows ： The Tuchengzi Formation not only has a long interval period with the Tiaojishan Formation, but also is very different from the Tiaojishan Formation in zircon geochemical characteristics. The Zhangjiakou Formation in time, but also is coincident with the Tuchengzi Formation not only is nearly continuous with the Zhangjiakou Formation in geochemistry of zircons. The resuhs imply that the Tuchengzi Formation and the Zhangjiakou Formation were formed in the same geological background, that is, there are not the boundary of the J3-K1 and the interface of the transition of tectonic framework between the Tuchengzi Formation and the Zhangjiakou Formation in the Luanping region. The research shows that the （Lu/Gd）N, δEu are two important parameters which are relatively stable in the analysis of zircons from Crust-source; but the values of ∑LREE of zircons from Crust-source change greatly, especially the abundance of La element, so some ratios of rare earth elements related with La （or ∑LREE） are not usable in determining the characteristics of zircons.
