Evolution of sexual dimorphism of wing shape in the Drosophila melanogaster subgroup

Background: Sexual dimorphism of body size has been the subject of numerous studies, but few have examined sexual shape dimorphism (SShD) and its evolution. Allometry, the shape change associated with size variation, has been suggested to be a main component of SShD. Yet little is known about the relative importance of the allometric and non-allometric components for the evolution of SShD. Results: We investigated sexual dimorphism in wing shape in the nine species of the Drosophila melanogaster subgroup. We used geometric morphometrics to characterise wing shape and found significant SShD in all nine species. The amount of shape difference and the diversity of the shape changes evolved across the group. However, mapping the divergence of SShD onto the phylogeny of the Drosophila melanogaster subgroup indicated that there is little phylogenetic signal. Finally, allometry accounted for a substantial part of SShD, but did not explain the bulk of evolutionary divergence in SShD because allometry itself was found to be evolutionarily plastic. Conclusion: SShD in the Drosophila wing can evolve rapidly and therefore shows only weak phylogenetic structure. The variable contribution of allometric and non-allometric components to the evolutionary divergence of SShD and the evolutionary plasticity of allometry suggest that SShD and allometry are influenced by a complex interaction of processes

Main dipoles of the CNAO accelerator: some general features and systematic effects associated with fluxmeter-based magnetic measurements

LPSC-acc ;This report presents some general characteristics of the main synchrotron dipole magnets designed for the CNAO project. It gives some estimates of field integrals and magnetic field flux using the TOSCA field maps. Then it aims to evaluate some systematic effects associated to the magnetic measurements planned with the fluxmeter, especially designed to characterize the CNAO dipoles. All of what follows was performed at maximum magnetic field without magnet shimming

Rotational velocities of A-type stars II. Measurement of vsini in the northern hemisphere

This work is the second part of the set of measurements of vsini for A-type stars, begun by Royer et al. (2002). Spectra of 249 B8 to F2-type stars brighter than V=7 have been collected at Observatoire de Haute-Provence (OHP). Fourier transforms of several line profiles in the range 4200--4600 A are used to derive vsini from the frequency of the first zero. Statistical analysis of the sample indicates that measurement error mainly depends on vsini and this relative error of the rotational velocity is found to be about 5% on average. The systematic shift with respect to standard values from Slettebak et al. (1975), previously found in the first paper, is here confirmed. Comparisons with data from the literature agree with our findings: vsini values from Slettebak et al. are underestimated and the relation between both scales follows a linear law: vsini(new) = 1.03 vsini(old) + 7.7. Finally, these data are combined with those from the previous paper (Royer et al. 2002), together with the catalogue of Abt & Morrell (1995). The resulting sample includes some 2150 stars with homogenized rotational velocities.Comment: 16 pages, includes 13 figures, accepted in A&

L'Ensenyament en català a la Catalunya del Nord: primer pas per a una eventual reversió sociolingüística

En el context de substitució lingüística del català pel francès a la Catalunya del Nord, la manca d'enquestes no permet conèixer amb precisió l'estat del català ni del seu ús efectiu en la societat. El marc legal francès i l'absència de consciència i de voluntat política de les administracions locals priven que se desenvolupi una política lingüística explícita a favor del català. L'ensenyament en català coneix una progressió lenta. El seu possible desenvolupament és la condició sine qua non per a una eventual reversió de l'evolució de la situació del català.Given the lack of research on the replacement of the Catalan language with French in Northern Catalonia, it is impossible to ascertain with any precision the status of Catalan or its actual use in this region. The French legal framework, combined with the lack of awareness and political interest of the local administrations, hinder the development of a language policy that explicitly promotes Catalan. The use of Catalan as the language of instruction is slowly taking root, and its further development is absolutely essential in order for there to be any possible reversal of the status of Catalan in this society

Molecular and ecophysiological characterisation of the Tunisian bee: Apis mellifera intermissa

This study concerns the morphological identification, the molecular features and the eco-physiology of the Tunisian bee Apis mellifera intermissa, focused on 655 colonies from 7 populations: Kroumirie Moogod, North East Cap Bon, Ridge and Tell, high steppe, lower steppe, Atlas Chainon, Jeffara and Ouarra. The geometric morphometry of the interior wing of the bee shows polymorphism in size and shape. The size polymorphism is essentialy related to beekeeping practices. The characterization by means of a cytoplasmic molecular marker - mitochondrial DNA (DNA m t) - showed that the Tunisian bee originated from lineage A, which contradicts its membership to lineage M as demonstrated by a study based on biometric data only (Ruttner, 1988). There is a genetic polymorphism of the Tunisian bee in the presence of four haplotypes: A1, A8, A9 and A4. The distribution of the A4 and A9 haplotypes depends on ecological conditions. Foreign haplotypes are present in the region of Ghardimaou near the Algerian border (C7 haplotype). The study of some ecophysiological parameters in colonies of Apis mellifera intermissa from 5 sites showed that the Tunisian bee is endowed with a very marked disregard for all haplotypes (A1, A4, A8 and A9). However, we report the existence of a difference between these haplotypes in thermoregulation, oviposition and respiration of solitary bees. The temperature of the A1 and A8 haplotypes brood nest is around 36°C while the A9 and A4 haplotypes brood nest has a temperature of 34°C when weather conditions are extreme. The A4 and A9 haplotypes fall into hibernation, the temperature of the brood nest ranging between 22 and 28°C. The A1 and A8 haplotypes have a high tendency to lay A9 and A4 haplotypes, which however is variable, ranging from zero to average depending on climatic conditions. A study of respiration of isolated honeybees showed a difference in oxygen consumption between haplotypes A1/ A8 and A4/A9 at low temperatures