Quaternary glaciations affected the distribution of many species. Here, we investigate whether the Arctic represented a glacial refugium during the Last Glacial Maximum or an area of secondary contact following the ice retreat, by analyzing the genetic population structure of the thick-billed murre (Uria lomvia), a seabird that breeds throughout the North Atlantic, North Pacific and Arctic Ocea...

The bill structures of different call types of red crossbills (Loxia curvirostra complex) in western North America usually approximate the predicted optima for foraging on single species of conifers. One clear exception is the call type in the South Hills, Idaho, that is coevolving in an evolutionary arms race with Rocky Mountain lodgepole pine (Pinus contorta ssp. latifolia). Although South Hi...

PURPOSE This study aimed to evaluate the situations and problems of the current health insurance fees for trauma surgeries. METHODS We reviewed the medical records and billing data from trauma surgeries performed in the hospital from August 2012 to July 2014. The name and number of surgeries were investigated and the code and number of operations prescribed by surgeons were compared with the ...

Ring-billed gulls (Larus delawarensis) and gray gulls (Larus modestus) are two species active both by day and night. We have investigated the retinal adaptations that allow the diurnal and nocturnal behaviours of these two species. Electroretinograms and histological analyses show that both species have a duplex retina in which cones outnumber rods, but the number of rods appears sufficient to ...

OBJECTIVE To determine provincial trends in provision of intrapartum care by general practitioners and family physicians (GP/FPs) for the 11 years from 1984 to 1995. DESIGN Analyses of provincial Medical Care Fee-for-Service Utilization data for births from 1984-1985 to 1994-1995. SETTING 10 provinces of Canada. MAIN OUTCOME MEASURES Proportion of vaginal births billed by GP/FPs (expresse...

A soft tissue structure has been discovered on the head of the duck-billed dinosaur Edmontosaurus. Its similarity to a cock's comb and other sexually dimorphic structures of birds suggests that potential sexual signals existed in these extinct animals.

of the dissertation ............................................................................................................. ii Acknowledgments......................................................................................................................... vii Vita .........................................................................................................................

Zimmer et al. (2001) documented two morphological and vocal forms within what was then known as Suiriri suiriri affinis, and described the short-billed form as Suiriri islerorum. However, studies of the Burmeister type material held at the Natural History Collections of the Martin-Luther-University Halle-Wittenberg, Germany, revealed the types of Suiriri s. affinis (Burmeister, 1856) to be the ...

A new dinosaur of Early Cretaceous age was recently discovered in the Gobi Desert of northwest China. It is more closely related to Late Cretaceous hadrosaurids than to Early Cretaceous iguanodontids. It occupies the most basal position in the phylogeny of all duck-billed dinosaurs, or the Hadrosauroidea. This early hadrosauroid sheds new light on the origin of the herbivorous feeding specializ...