165 research outputs found

    Informality, Productivity and Growth in Mexico, 2000.Q2-2014.Q4

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    The huge growth of the informal sector, the labor market relief valve, has conditioned the low Mexican economic growth since the early 1980ÂŽs. From a Lewis (1954) modelÂŽs review, we propose that the growth of informality has limited economic growth, through the systematically factorial productivity reduction. A VECM(4) supports evidence about the factorial productivity reduction by the informal sector growth, associated with slow Mexican economic growth to perpetuate the productivity vicious circle too hard to break

    The Effects of Earthquakes and Fluids on the Metamorphism of the Lower Continental Crust

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    Rock rheology and density have first‐order effects on the lithosphere's response to plate tectonic forces at plate boundaries. Changes in these rock properties are controlled by metamorphic transformation processes that are critically dependent on the presence of fluids. At the onset of a continental collision, the lower crust is in most cases dry and strong. However, if exposed to internally produced or externally supplied fluids, the thickened crust will react and be converted into a mechanically weaker lithology by fluid‐driven metamorphic reactions. Fluid introduction is often associated with deep crustal earthquakes. Microstructural evidence, suggest that in strong highly stressed rocks, seismic slip may be initiated by brittle deformation and that wall‐rock damage caused by dynamic ruptures plays a very important role in allowing fluids to enter into contact with dry and highly reactive lower crustal rocks. The resulting metamorphism produces weaker rocks which subsequently deform by viscous creep. Volumes of weak rocks contained in a highly stressed environment of strong rocks may experience significant excursions toward higher pressure without any associated burial. Slow and highly localized creep processes in a velocity strengthening regime may produce mylonitic shear zones along faults initially characterized by earthquake‐generated frictional melting and wall rock damage. However, stress pulses from earthquakes in the shallower brittle regime may kick start new episodes of seismic slip at velocity weakening conditions. These processes indicate that the evolution of the lower crust during continental collisions is controlled by the transient interplay between brittle deformation, fluid‐rock interactions, and creep flow

    Les réinterventions pour dégénérescence de bioprothÚses péricardiques (17 ans d'expérience et 53 patients consécutifs)

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    TOURS-BU MĂ©decine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Dissections aortiques de type A (Stanford) opérées au CHU de Tours entre 1985 et 2003 (suivi à long terme)

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    TOURS-BU MĂ©decine (372612103) / SudocSudocFranceF

    Mechano-chemical feedbacks during deformation and hydration of peridotites

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    The hydration of the Earth’s mantle is a crucial process for many aspects of our planet, from the behaviour of the tectonic plates to the global water cycle and the origin of life. This process is called serpentinization and has a considerable impact on the rock’s behaviour when under stress. It makes rocks easier to break and is associated with a volume increase that can locally perturb tectonic stress and break surrounding rocks. The rock composing the mantle, peridotite, has however a very low permeability, and water has difficulties to circulate within it. Faulting is thus intimately linked to the water supply during serpentinization. Even though the link between faulting and serpentinization has been established, the way these two processes interact is not fully understood. Tectonically and seismically active zones in oceanic context are recognized to be preferred zones of serpentinization, but most common models for serpentinization do not reflect this major role of tectonics. This work highlights the role of tectonics in serpentinization initiation and maintenance through a combination of microstructural and seismic studies

    Résultat à moyen terme de la chirurgie cardiaque chez l'octogénaire

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    Le vieillissement de la population est un phĂ©nomĂšne d'actualitĂ©. L'objectif est d'Ă©tudier les rĂ©sultats Ă  moyen terme, ainsi que les facteurs de risque influant le rĂ©sultat de la chirurgie cardiaque d'une population d'octogĂ©naires. 169 patients consĂ©cutifs ont Ă©tĂ© opĂ©rĂ©s en chirurgie cardiaque entre le 01/01/2000 et le 31/12/2003 selon les indications de l'Ă©poque et la stratĂ©gie du service. La moyenne d'Ăąge est de 82,5 +- 2,9 ans. Il s'agit de 52,6% d'hommes. 85,7% des patients Ă©taient en rythme sinusal. Le stade NYHA moyen est de 2,5 avec 53% des patients en stade III ou IV. L'Euroscope moyen est de 7,98 +- 1,79. Il s'agissait de 64 pathologies valvulaires aortiques, 43 coronariens, 13 pathologies mitrales, 40 pathologies mixtes, 4 valvulopathies multiples et 5 pathologies diverses. Les donnĂ©es mĂ©dicales ont Ă©tĂ© recueillies par une analyse rĂ©trospective des dossiers mĂ©dicaux et le suivi Ă  moyen terme a Ă©tĂ© rĂ©alisĂ© en contactant le mĂ©decin traitant de chaque patient durant le mois de fĂ©vrier 2006. Nous avons analysĂ© la survie et les paramĂštres influençant la mortalitĂ©. L'analyse statistique classique a Ă©tĂ© rĂ©alisĂ©e. La mortalitĂ© hospitaliĂšre globale a Ă©tĂ© de 8,2%. 43,7% des patients ont prĂ©sentĂ© au moins une complication grave. 6 patients ont Ă©tĂ© perdus de vue (3,5%). Le suivi moyen est de 36,6 mois et le suivi total de 515 annĂ©es patients (suivi entre 25 et 74 mois). La survie actuarielle est de 82,7% Ă  1 an, 79% Ă  2 ans et de 58,7% Ă  5 ans. 109 patients sont vivants lors du suivi. 73,8% sont en rythme sinusal, le stade NYHA moyen est de 1,7 avec 80% des patients en stade NYHA I ou II. 86,2 % d'entre eux sont considĂ©rĂ©s autonomes Ă  domicile. Nous avons mis en Ă©vidence comme prĂ©dictif de dĂ©cĂšs prĂ©coce les antĂ©cĂ©dents d'accidents vasculaires cĂ©rĂ©braux, l'obĂ©sitĂ© l'insuffisance rĂ©nale prĂ©opĂ©ratoire et certaines complications post-opĂ©ratoires (le bas dĂ©bit cardiaque, l'insuffisance cardiaque, l'insuffiance rĂ©nale aigĂŒe mĂȘme transitoire, la nĂ©cessitĂ© d'avoir recours Ă  la perfusion d'amine vasopressive). Enfin, la courbe de survie rejoint celle de la population gĂ©nĂ©rale du mĂȘme Ăąge. L'Ă©valuation de la fonction rĂ©nale prĂ©cise ainsi que de l'Ă©tat nutritionnel permet encore d'affiner la valeur prĂ©dictive de l'Euroscore. L'extension des indications de la chirurgie cardiaque Ă  une tranche d'Ăąge supĂ©rieure paraĂźt lĂ©gitime sous couvert d'une sĂ©lection rigoureuse.TOURS-BU MĂ©decine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    PRODUCCION DE DEXTRANAS CLINICAS

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