38 research outputs found

    Origin of the high elevated Pyrenean peneplain

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    Peneplanation of mountain ranges is generally considered the result of long-term erosional processes that smooth relief and lower elevation near sea level. Therefore peneplain remnants at high elevation in mountain ranges are used to infer posttectonic surface uplift. Such an interpretation has been proposed for the Pyrenees where high-elevation, low-relief erosional surfaces rose up to more than 2000 m. Because the Pyrenean foreland basins are filled with very thick continental deposits, which have buried the early jagged landscape, we challenge this hypothesis by pointing out that relief applanation does not necessarily require elevation lowering. We propose an alternative interpretation in which piedmont aggradation of detrital sediment that comes from erosion of the high chain induces the rise of the base level of the range, therefore reducing strongly the erosive efficiency of the drainage system and resulting in the progressive smoothing of the relief. Such a process allows a high-elevation, low-relief erosional surface to develop at the scale of the range. In the Pyrenees, occurrence of high-elevation, low-relief erosional surface remnants does not imply a posttectonic uplift, but is instead due to the dissection of the initial Miocene high-elevation, low-relief surface by the recent drainage system, the erosive activity of which has been enhanced by global climate change from the late Pliocene onward

    Underlying Event measurements in pp collisions at s=0.9 \sqrt {s} = 0.9 and 7 TeV with the ALICE experiment at the LHC

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    Le concept de globalisation : mythes et réalités

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    The concept of 'gobalization' has become commonly used to refer to the unprecedented degree of economic integration characterizing the world economy in the last decades of the twentieth century. However opinions differ as to whether this merely corresponds to a stage in the development of the world’s economy, or else to a complete break with the past. The shape to be taken by the global economy once the process is completed — if it can be completed, in view of the various forces that may slow it down — is also a matter of debate. After identifying an added difficulty posed by the translation of 'globalization' into French, this paper reviews the literature on these various issues and concludes that the advent of a fully globalized economy may neither be automatic nor entirely desirable

    Entretien avec Alain Epelboin

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    Crochet Soizick, Epelboin Alain. Entretien avec Alain Epelboin. In: Journal des anthropologues, n°52, Printemps – Ă©tĂ© 1993. Situations incertaines. pp. 95-103

    Direct and indirect estimates of dispersal support strong juvenile philopatry and male‐biased dispersal in a freshwater turtle species (<i>Emys orbicularis</i>)

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    This monitoring was conducted under the ethical approval of the Museum National d'Histoire Naturelle de Paris (MNHN Paris) through the personal research program of A. Olivier (no. 405), in accordance with the French legislation and respect of the require-ments and principles of the Charter of Fundamental Rights of the European Union.International audienceDispersal has major impacts on population dynamics, population genetics and evolution, and also is critical for population management and conservation. Dispersal is frequently sex- and age-specific, but current knowledge is strongly taxonomically biased toward birds and mammals. Here, we provide estimates of dispersal in a threatened freshwater turtle species, the European pond turtle Emys orbicularis. Based on 15 years of capture-mark-recapture (CMR) monitoring and DNA samples from 194 individuals, we quantified both demographic and genetic dispersal between three sites separated by 1.5-3.5 km. We also investigated the effect of age and sex on dispersal.Direct (CMR) and indirect (genetic) approaches provided consistent results, showing that the studied sites are connected with a flow of about one to three dozen migrants per generation. Dispersal was both age- and sex-biased in this species, with frequent dispersal of adult males and a strong philopatry of juveniles (of both sexes) and adult females.The network of canals and marshes allow effective dispersal to occur among the three study sites despite the relatively large distance separating them (=3.5 km).The strong philopatry of juveniles contrasts with the frequently higher dispersal rate in young birds and mammals and shows the relevance of investigating dispersal in various taxonomic groups. Our results provide useful information for the conservation of European pond turtle populations

    Tethered oxocyclohexadienyl piano-stool Ru(II) complexes: a new class of metal-ligand bifunctional catalysts

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    International audienceThe straightforward synthesis of tethered η5-oxocyclohexadienyl metal complexes is presented. Preliminary studies in catalysis demonstrate that these tethered half-sandwich Ru(II) complexes behave as bifunctional catalysts with metal-ligand cooperativity and are promising candidates for the development of hydrogen-based energies and chemical storage (i.e. dissociated hydrogen)

    Le modĂšle Ă©conomique anglo-saxon Ă  l’épreuve de la globalisation

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    Depuis le dĂ©but des annĂ©es 1990 l'Ă©conomie mondiale semble s'engager de plus en plus dans la voie de la globalisation. Pour d'aucuns, cette globalisation tendrait Ă  imposer le modĂšle anglo-saxon, libĂ©ral par nature, Ă  l'ensemble de la planĂšte. Cet ouvrage, qui rassemble les actes du colloque organisĂ© en avril 1995 Ă  l'UniversitĂ© de la Sorbonne Nouvelle par le Centre d'Ă©tudes et de recherches sur la vie Ă©conomique des pays anglo-saxons (CERVEPAS), entend contribuer Ă  retoucher cette image. Il montre que si la globalisation constitue Ă  certains Ă©gards le vecteur de la propagation de certaines spĂ©cificitĂ©s anglo-saxonnes dans d'autres rĂ©gions du globe, il existe nĂ©anmoins un Ă©cart sensible entre la rĂ©alitĂ© du fonctionnement de l'Ă©conomie amĂ©ricaine et de l'Ă©conomie britannique et le modĂšle thĂ©orique qu'elles ont inspirĂ© et qu'elles sont censĂ©es incarner. La globalisation les soumet par ailleurs Ă  une Ă©preuve dont l'issue pourrait bien ĂȘtre la mise en cause du modĂšle auquel elles ont donnĂ© naissance

    Intégration dans les Amériques

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    Dix ans aprĂšs la signature du traitĂ© instituant l'Accord de libre-Ă©change de l'AmĂ©rique du Nord (ALENA) et Ă  l'heure oĂč le projet de Zone de libre-Ă©change des AmĂ©riques (ZLEA) semblait devoir se concrĂ©tiser pour 2005, il Ă©tait temps de dresser, pour la premiĂšre fois en France, un bilan des effets, tant sociaux et culturels qu'Ă©conomiques, de cet accord et des dĂ©bats qu'il a suscitĂ©s au Canada, aux États-Unis et au Mexique. L'ALENA est ici traitĂ© comme un exemple particuliĂšrement dĂ©monstratif des nouveaux processus d'intĂ©gration rĂ©gionale qui ont connu une intensification remarquable pendant la derniĂšre dĂ©cennie, tant en AmĂ©rique que dans le reste du monde. Les questions importantes soulevĂ©es au moment de sa signature et de sa ratification restent d'actualitĂ© : questions politiques au sens large, qui portent sur la souverainetĂ© des États contractants, la protection des droits des travailleurs et de l'environnement, mais aussi consĂ©quences Ă©conomiques, territoriales et sociales d'une nouvelle configuration gĂ©opolitique, reprĂ©sentant un « bloc » de 400 millions d'habitants. Ces questions sont abordĂ©es ici dans une perspective pluridisciplinaire, favorisĂ©e par la diversitĂ© des points de vue portĂ©s sur l'intĂ©gration nord-amĂ©ricaine par une vingtaine d'universitaires et de chercheurs mexicains, canadiens, amĂ©ricains et français
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