Background:The uropygial gland is an exocrine gland located above the tail of birds that produces a diverse range of biochemicals.It has been hypothesized to be involved in chemical protection,water-proofing and maint...Background:The uropygial gland is an exocrine gland located above the tail of birds that produces a diverse range of biochemicals.It has been hypothesized to be involved in chemical protection,water-proofing and maintenance of plumage brightness.Although these not necessarily mutually exclusive functions have received some empirical support,there has been little empirical research on the function of water-proofing.Methods:Here we analyzed data for 229 individual eiders(Somateria mollissima)collected by Danish hunters during 2016-2018.Results:The Eider is a sea-duck that spends almost its entire life in sea water emphasizing water-proofing of the plumage.The size of the uropygial gland increased with body mass in males,but not in females,and it increased with age.The size of the uropygial gland decreased during winter. Eiders with small uropygial glands grew their feathers at a fast rate.Eiders with large wing areas had large uropygial glands. Conclusions:These findings are consistent with large uropygial glands playing a role in water-proofing during molt and foraging, but also that uropygial glands may play a role in chemical defense.展开更多
The objective of this work was to study the effect of the heat treatment and further operation aging on the stereological parameters(size,quantity and volume fraction)of precipitates within ferrite grains of a creep-r...The objective of this work was to study the effect of the heat treatment and further operation aging on the stereological parameters(size,quantity and volume fraction)of precipitates within ferrite grains of a creep-resistant 1.25Cr0.5Mo steel after long-term operation.The heat treatment was similar to the treatment that is carried out in industrial steam pipelines after welding(post weld heat treatment-PWHT)during installation and/or repairing.The operation aging corresponds to a subsequent long in-service operation after repairing.To determine the stereological parameters,SEM digital images were taken from samples of this material after conditions of in-service-aged(after long-term operation),in-service-aged and heat-treated(simulating repairing)and in-service-aged,heat-treated and in-laboratory aged(simulating subsequent long-term operation after repairing).The results indicate that the changes in the stereological parameters of the precipitates within ferrite grains after PWHT is associated with the coarsening process of the within-ferrite-grain precipitates as well as stabilizing the microstructure,since the material aging after PWHT of an in-serviced aged material would not change the stereological parameters.展开更多
文摘Background:The uropygial gland is an exocrine gland located above the tail of birds that produces a diverse range of biochemicals.It has been hypothesized to be involved in chemical protection,water-proofing and maintenance of plumage brightness.Although these not necessarily mutually exclusive functions have received some empirical support,there has been little empirical research on the function of water-proofing.Methods:Here we analyzed data for 229 individual eiders(Somateria mollissima)collected by Danish hunters during 2016-2018.Results:The Eider is a sea-duck that spends almost its entire life in sea water emphasizing water-proofing of the plumage.The size of the uropygial gland increased with body mass in males,but not in females,and it increased with age.The size of the uropygial gland decreased during winter. Eiders with small uropygial glands grew their feathers at a fast rate.Eiders with large wing areas had large uropygial glands. Conclusions:These findings are consistent with large uropygial glands playing a role in water-proofing during molt and foraging, but also that uropygial glands may play a role in chemical defense.
基金supported by the bilateral agreement CAPES-Brazil/MES–Cuba(project number 146/12)carried out at the Brazilian research laboratories LAPROSOLDA-LDTAD from Federal University of Uberlandia(UFU)DEMa-CCDM from Federal University of Sao Carlos(UFSCar)。
文摘The objective of this work was to study the effect of the heat treatment and further operation aging on the stereological parameters(size,quantity and volume fraction)of precipitates within ferrite grains of a creep-resistant 1.25Cr0.5Mo steel after long-term operation.The heat treatment was similar to the treatment that is carried out in industrial steam pipelines after welding(post weld heat treatment-PWHT)during installation and/or repairing.The operation aging corresponds to a subsequent long in-service operation after repairing.To determine the stereological parameters,SEM digital images were taken from samples of this material after conditions of in-service-aged(after long-term operation),in-service-aged and heat-treated(simulating repairing)and in-service-aged,heat-treated and in-laboratory aged(simulating subsequent long-term operation after repairing).The results indicate that the changes in the stereological parameters of the precipitates within ferrite grains after PWHT is associated with the coarsening process of the within-ferrite-grain precipitates as well as stabilizing the microstructure,since the material aging after PWHT of an in-serviced aged material would not change the stereological parameters.
