Background:Field studies from 2011 onwards have demonstrated the presence of a breeding population of Yellow Wagtails(Motacilla flava)in the Xinjiang Uygur Autonomous Region,China that is phenotypically distinct from ...Background:Field studies from 2011 onwards have demonstrated the presence of a breeding population of Yellow Wagtails(Motacilla flava)in the Xinjiang Uygur Autonomous Region,China that is phenotypically distinct from known subspecies occurring in Asia.Here we describe the plumages and vocalisations of this population and discuss its taxonomic status.Methods:The analysis of plumage is based on field studies and photos available online.Recordings of vocalisations are compared with recordings from other Yellow Wagtail populations,and differences are analysed based on sonograms.Mitochondrial DNA from one individual is compared to other Yellow Wagtail taxa.Results:Unlike M.flava subspecies breeding in or near Xinjiang,males in the studied population show a blue-grey head without prominent white supercilium,being most similar to the widely disjunct M.f.cinereocapilla.They differ from the similarly widely allopatric M.f.thunbergi,which might occur as a migrant or vagrant in Xinjiang,by on average cleaner yellow breast and more extensive white on the throat,and from the widely disjunct M.f.plexa and M.f.macronyx,which might also occur on migration in that area,by softer contact calls and slower pace of song.Females are similar to female M.f.feldegg in plumage.The mitochondrial ND2 tree shows the single sample from Xinjiang to be nested in the clade of western Yellow Wagtail taxa.Conclusion:We discuss whether the Xinjiang breeding population could represent an intergrade between subspecies breeding nearby,or whether it is better regarded as a separate as yet unrecognized subspecies.We argue that the localization of its apparent range in relation to other subspecies along with fairly consistent male and female plumages suggest that it is more likely to represent an undescribed taxon,but conclude that more research is needed to firmly establish its status.展开更多
Introduction: A novel three dimensional approach for aneuploidy screening in the first trimester of pregnancy was developed in which risk assessment derives directly from comparing the plotted data of nuchal transluce...Introduction: A novel three dimensional approach for aneuploidy screening in the first trimester of pregnancy was developed in which risk assessment derives directly from comparing the plotted data of nuchal translucency, pregnancy associated plasma protein A (PAPP-A), and free β-human chorionic gonadotropin (fβ-hCG) of an examined fetus with similar coordinates of fetuses with already known health status. Under this approach, it is possible to utilize either a ‘box’ or a ‘sphere’ model. In either case, optimal volume sizes and the benefits of adopting a ‘minimum number of required fetuses’ (MNR) have not yet been investigated;and for the box model, two modifications, called ‘empty box results positive’ (EB+) and ‘simulation’ (SIM), provide additional options. It was the aim of this study to analyze which of the two models and their variants provides the best test performance. Methods: The study cohort was divided into a reference collective (n = 10,954) and a test collective (n = 4239). The test collective was examined repeatedly, with another model and modification used on each occasion. Test performances were compared by the area under curve (AUC) of receiver operating characteristics (ROC) curves. Results: The sphere model was inferior to the box model when optimal volumes were used with the latter and combined with the modifications EB+ and Sim. EB+ increased the number of assessable fetuses while Sim improved the test performance. MNR improved neither the box nor the sphere model. Conclusion: A new, optimized model in line with the obtained results should be developed and tested in further studies.展开更多
基金support from Jornvall Foundation and the Swedish Research Council(grant No.2015-04402)。
文摘Background:Field studies from 2011 onwards have demonstrated the presence of a breeding population of Yellow Wagtails(Motacilla flava)in the Xinjiang Uygur Autonomous Region,China that is phenotypically distinct from known subspecies occurring in Asia.Here we describe the plumages and vocalisations of this population and discuss its taxonomic status.Methods:The analysis of plumage is based on field studies and photos available online.Recordings of vocalisations are compared with recordings from other Yellow Wagtail populations,and differences are analysed based on sonograms.Mitochondrial DNA from one individual is compared to other Yellow Wagtail taxa.Results:Unlike M.flava subspecies breeding in or near Xinjiang,males in the studied population show a blue-grey head without prominent white supercilium,being most similar to the widely disjunct M.f.cinereocapilla.They differ from the similarly widely allopatric M.f.thunbergi,which might occur as a migrant or vagrant in Xinjiang,by on average cleaner yellow breast and more extensive white on the throat,and from the widely disjunct M.f.plexa and M.f.macronyx,which might also occur on migration in that area,by softer contact calls and slower pace of song.Females are similar to female M.f.feldegg in plumage.The mitochondrial ND2 tree shows the single sample from Xinjiang to be nested in the clade of western Yellow Wagtail taxa.Conclusion:We discuss whether the Xinjiang breeding population could represent an intergrade between subspecies breeding nearby,or whether it is better regarded as a separate as yet unrecognized subspecies.We argue that the localization of its apparent range in relation to other subspecies along with fairly consistent male and female plumages suggest that it is more likely to represent an undescribed taxon,but conclude that more research is needed to firmly establish its status.
文摘Introduction: A novel three dimensional approach for aneuploidy screening in the first trimester of pregnancy was developed in which risk assessment derives directly from comparing the plotted data of nuchal translucency, pregnancy associated plasma protein A (PAPP-A), and free β-human chorionic gonadotropin (fβ-hCG) of an examined fetus with similar coordinates of fetuses with already known health status. Under this approach, it is possible to utilize either a ‘box’ or a ‘sphere’ model. In either case, optimal volume sizes and the benefits of adopting a ‘minimum number of required fetuses’ (MNR) have not yet been investigated;and for the box model, two modifications, called ‘empty box results positive’ (EB+) and ‘simulation’ (SIM), provide additional options. It was the aim of this study to analyze which of the two models and their variants provides the best test performance. Methods: The study cohort was divided into a reference collective (n = 10,954) and a test collective (n = 4239). The test collective was examined repeatedly, with another model and modification used on each occasion. Test performances were compared by the area under curve (AUC) of receiver operating characteristics (ROC) curves. Results: The sphere model was inferior to the box model when optimal volumes were used with the latter and combined with the modifications EB+ and Sim. EB+ increased the number of assessable fetuses while Sim improved the test performance. MNR improved neither the box nor the sphere model. Conclusion: A new, optimized model in line with the obtained results should be developed and tested in further studies.
