The theory of reinforcement predicts that natural selection against the production of unfit hybrids favours traits that increase assortative mating. Whether culturally inherited traits, such as bird song, can increase assortative mating by reinforcement is largely unknown. We compared songs of pied (Ficedula hypoleuca) and collared flycatchers (F. albicollis) from two hybrid zones of different ...

We present here a six-species comparison of tree-ring growth response to extremes (below the 30th and above the 70th percentile) in temperature, precipitation, and corresponding streamflow. The species compared are Pinus edulis (PIED), Pseudotsuga menziesii (PSME), Pinus ponderosa (PIPO), Pinus flexilis (PIFL), Pinus aristata (PIAR), and Picea engelmannii (PCEN). Sensitivity was determined usin...

A13STRACT.--Genomic DNA libraries of the Barn Swallow (Hirundo rustica) and the Pied Flycatcher (Ficedula hypoleuca) were screened for the presence of dinucleotide microsatellite repeats. Two thymine-guanine repeats, "(TG),," and two thymine-cytosine repeats, "(TC),," were isolated and sequenced from the two species, respectively. Polymerase-chain-reaction (PCR) analysis of 25 unrelated Barn Sw...

The use of performance- and image-enhancing drugs/substances (PIED) outside elite sports appears to be increasing, although the current knowledge of the nature of PIED use among recreational athletes is scarce. The present study analyzed enquiries that were submitted to the Danish Anti Doping Agency (ADD) over an 18-month period, to gain knowledge of PIED use among individuals who exercise recr...

In this paper we propose a syntactic and semantic analysis of complex questions. We consider questions involving pied piping and stranding and we propose elementary trees and semantic representations that allow to account for both constructions in a uniform way.

Introduction: véritable attribut de la féminité, le port de chaussures à talons est devenu une exigence professionnelle dans certaines structures des pays en développement comme le Bénin. L'objectif de ce travail est de déterminer les effets spécifiques du port de chaussures à talons hauts sur le squelette appendiculaire inférieur. Méthodes: des examens radiographiques de face et de profil de l...