Background: In temperate-breeding birds, individuals must adjust their physiological states from one life-history stage to another in response to changing conditions to maximize ecological fitness. Previous evidences ...Background: In temperate-breeding birds, individuals must adjust their physiological states from one life-history stage to another in response to changing conditions to maximize ecological fitness. Previous evidences have shown that body mass, size-corrected mass(SCM), and hematocrit(Hct) could be used as estimates of the energetic state of individuals to illustrate life-history trade-offs and individual quality in field physiology. Plasma alkaline phosphatase(ALP) plays critical roles in regulating the metabolism of energy but very limited information is known on its link with body mass or Hct.Methods: We determined the changes of plasma ALP levels in both early breeding and wintering stages of male Eurasian Tree Sparrows(Passer montanus), and examined the relationships between ALP and body mass, SCM, and Hct of the birds.Results: Our study showed that(1) in male Eurasian Tree Sparrows, body mass did not vary with life-history stage but plasma ALP activity significantly increased in the wintering stage compared to the breeding stage;(2) ALP activity was not correlated with individual body mass but was positively correlated with individual SCM and Hct. Such positive correlations, however, only occurred in the wintering but not in the breeding stages.Conclusions: Our results suggest that plasma ALP activities in free-living birds can be used as one of the indicators o body condition or nutritional status for analyzing individual variation in the wintering but not in the breeding stages. The life-history dependent relationships between plasma ALP activity and body condition may contribute to our better understanding of the trade-off between individual survival and reproduction in free-living animals.展开更多
Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 2...Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 20th century, the company became well known in Europe especially for metallic constructions, having built the majority of metal bridges in the north of Italy such as the famous Paderno bridge （1887-1889）, one of the biggest arch bridge for the period. In the 1930s, the company built some interesting examples of steel frame buildings, applying the electrical welding technique, acquired in industrial constructions, to civil buildings. The steel frame was quite rare in Italian buildings, especially in the matter of civil constructions and Savigliano made an effort in modernizing the Italian construction system, through research and innovation. The paper will discuss some examples of Savigliano＇s works dating back to 1930, and in particular, it will present a specific example never studied before： the hangar at the Elmas military airport, in Cagliari （Sardinia）. The building is worth mentioning for the innovations experimented, as the new welding technique allowed a series of improvements in the construction process.展开更多
Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits o...Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits on islands. Lifehistory theory also predicts that there is a trade-off between body size and reproductive effort, and between egg size and clutch size. We surveyed the rice frog, Fejervarya limnocharis, on 20 islands within the Zhoushan Archipelago and two nearby sites on the mainland of China to compare differences in life-history traits and to explore relationships among those traits. Rice frog females reached a greater body size on half of the smaller islands among the total 20 surveyed islands, and larger egg size, decreased clutch size and reduced reproductive effort on most of the islands when compared to the two mainland sites. Insular body size was negatively correlated with reproductive effort. There was a negative correlation between egg size and clutch size. Results suggest that life-history theory provides a good explanation for co-variation between body size and reproductive effort, and between egg size and clutch size in rice frogs on the islands.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 31672292, 31372201)the Natural Science Foundation of Hebei Province (C2017205059)
文摘Background: In temperate-breeding birds, individuals must adjust their physiological states from one life-history stage to another in response to changing conditions to maximize ecological fitness. Previous evidences have shown that body mass, size-corrected mass(SCM), and hematocrit(Hct) could be used as estimates of the energetic state of individuals to illustrate life-history trade-offs and individual quality in field physiology. Plasma alkaline phosphatase(ALP) plays critical roles in regulating the metabolism of energy but very limited information is known on its link with body mass or Hct.Methods: We determined the changes of plasma ALP levels in both early breeding and wintering stages of male Eurasian Tree Sparrows(Passer montanus), and examined the relationships between ALP and body mass, SCM, and Hct of the birds.Results: Our study showed that(1) in male Eurasian Tree Sparrows, body mass did not vary with life-history stage but plasma ALP activity significantly increased in the wintering stage compared to the breeding stage;(2) ALP activity was not correlated with individual body mass but was positively correlated with individual SCM and Hct. Such positive correlations, however, only occurred in the wintering but not in the breeding stages.Conclusions: Our results suggest that plasma ALP activities in free-living birds can be used as one of the indicators o body condition or nutritional status for analyzing individual variation in the wintering but not in the breeding stages. The life-history dependent relationships between plasma ALP activity and body condition may contribute to our better understanding of the trade-off between individual survival and reproduction in free-living animals.
文摘Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 20th century, the company became well known in Europe especially for metallic constructions, having built the majority of metal bridges in the north of Italy such as the famous Paderno bridge （1887-1889）, one of the biggest arch bridge for the period. In the 1930s, the company built some interesting examples of steel frame buildings, applying the electrical welding technique, acquired in industrial constructions, to civil buildings. The steel frame was quite rare in Italian buildings, especially in the matter of civil constructions and Savigliano made an effort in modernizing the Italian construction system, through research and innovation. The paper will discuss some examples of Savigliano＇s works dating back to 1930, and in particular, it will present a specific example never studied before： the hangar at the Elmas military airport, in Cagliari （Sardinia）. The building is worth mentioning for the innovations experimented, as the new welding technique allowed a series of improvements in the construction process.
基金supported by the grant from the"973"Program of China(No.2007CB411600)the Chinese Academy of Sciences(CAS)(No.kscx2-yw-z-1021)the"Xi Bu Zhi Guang"Program of CAS(No.XBBS201102)
文摘Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits on islands. Lifehistory theory also predicts that there is a trade-off between body size and reproductive effort, and between egg size and clutch size. We surveyed the rice frog, Fejervarya limnocharis, on 20 islands within the Zhoushan Archipelago and two nearby sites on the mainland of China to compare differences in life-history traits and to explore relationships among those traits. Rice frog females reached a greater body size on half of the smaller islands among the total 20 surveyed islands, and larger egg size, decreased clutch size and reduced reproductive effort on most of the islands when compared to the two mainland sites. Insular body size was negatively correlated with reproductive effort. There was a negative correlation between egg size and clutch size. Results suggest that life-history theory provides a good explanation for co-variation between body size and reproductive effort, and between egg size and clutch size in rice frogs on the islands.
