487 research outputs found

    LES RESSOURCES HUMAINES ET LA STRATEGIE DE L’ENTRPRISE

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    HUMAN RESOURCES AND COMPANY STRATEGY This article focuses on the issue of HUMAN RESOURCES AND CORPORATE STRATEGY from a strategic point of view and Globalization and its impact on Human resources

    Échanges en surface dans le modèle de chimie transport multi-échelles MOCAGE

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    Les échanges en surface dans le Modèle de Chimie Transport (MCT) multi-échelles MOCAGE de Météo-France comprennent à la fois les flux d'émissions et de dépôt sec d'espèces gazeuses. Une interface 2D a été développée entre MOCAGE et le modèle de prévisions météorologiques opérationnel français ARPEGE dans le but de calculer des flux à la surface réalistesPour les émissions, un inventaire global est employé pour le moment; cet inventaire a été construit essentiellement à partir des inventaires des programmes IGAC/GEIA (International Global Atmospheric Chemistry / Global Emission Inventory Activity) et EDGAR (Emission Database for Global Atmospheric Research qui ont des résolutions temporelles annuelles, sai-sonnières ou mensuelles et une résolution spatiale de un degré.Le dépôt sec d'espèces gazeuses, y compris l'ozone, le dioxyde de soufre, les composés azotés, les composés organiques à longue et à courte durée de vie, a été paramétrisé selon [Wesely, 1989]. Le modèle calcule la vitesse de dépôt à partir de valeurs de trois résistances en série, les résistances aérodynamique, laminaire et de la surface. Ces résistances sont calculées en utilisant les champs de surface d'ARPEGE. Les champs liés à la végétation, tels l'indice foliaire, sont prescrits avec une résolution de un degré sur le globe et de cinq minutes sur l'Europe. Un certain nombre de modifications a été apporté à la paramétrisation de [Wesely, 1989], par exemple pour la formulation de la résistance stomatale et celle de la résistance de surface sur les surfaces mouillées. Les valeurs calculées de vitesse de dépôt ont été comparées à des observations et leurs distributions spatiales et temporelles ont été analysées sur deux saisons opposées (hiver et été, sur les différents domaines de MOCAGE, de résolution allant de 2 degrés pour le globe à 0.25 degrés pour la France.Surface exchanges considered in the MOCAGE multiscale Chemistry and Transport Model (CTM) of Météo-France include both emissions and dry deposition of gaseous species. To compute realistic time-dependent fluxes at the surface, a 2D interface between MOCAGE and ARPEGE, the French operational numerical weather prediction model, was developed.With regard to emissions, a default global inventory is presently employed. Built mainly from the IGAC/GEIA (International Global Atmospheric Chemistry / Global Emission Inventory Activity) and the EDGAR (Emission Database for Global Atmospheric Research programs, this inventory has an annual, seasonal or monthly temporal resolution, and a degree-by-degree spatial resolution.Dry deposition of gaseous species, including ozone, sulfur dioxide, nitrogen-containing com-pounds, long-lived and short-lived intermediates organic compounds, were parameterised ac-cording to [Wesely, 1989]. The model calculates dry deposition velocities from three resistances in series: aerodynamic, laminar, and surface. These resistances are computed using the surface fields obtained from the analyses or forecasts of ARPEGE. Vegetation fields such as the Leaf Area Index are prescribed with a one-degree spatial resolution at the global scale, and a five-minute resolution over Europe. A number of modifications was incorporated into the original surface resistance scheme (e.g., the formulation of stomatal resistance and surface resistance over wet surfaces. Calculated dry deposition velocities were compared to observations, and the spatial and temporal distributions were analysed for two different seasons (summer and winter) using the varions MOCAGE domains of varying resolutions (from 2 degrees over the globe to 0.25 degrees over France)

    Parthenogenetic activation decreases the polyphosphoinositide content of frog eggs

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    AbstractPolyphosphoinositides were quantified in metaphase II-arrested eggs of the amphibian Xenopuslaevis, and 8–10 min later in eggs activated by pricking. The content of phosphatidylinositol 4,5-biphosphate (PIP2) was remarkably high in metaphase II-arrested eggs with respect to that of phosphatidylinositol 4-phosphate (PIP). It was found to drop dramatically at activation. In contrast PIP content did not change significantly

    How can we know whether fish feel pain? Epistemology of the scientific study of fish sentience

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    I start by defining sentience and giving an analysis of the epistemological problems that plague its scientific study; this consists mainly in justifying that the attribution of sentience is underdetermined by the data. Second I show that as a result of this situation of underdetermination, most of the types of arguments used to infer sentience from the data are inconclusive and lead to a stalemate. Third, I argue that the stalemates arise from a foundationalist epistemology which needlessly leads to skeptical conclusions; as an alternative, I propose to adopt a coherentist framework and defend a process of ‘epistemic iteration’ (Chang 2004) within that framework, which I argue gives us a way out of the underdetermination

    From roses to bullets: the rise and decline of post-Soviet colour revolutions

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    The chapter explores the reasons for the colour revolutions’ successes and failures in the post-Soviet space. The article starts with an overview on the colour movement from the first stirrings to the present day. We then propose criteria that will be applied to our analysis, constructed on five variables. The factual analysis of individual countries that follows is built around these five variables

    Le reporting environnemental : simple effet de mode ou vrai enjeu stratégique pour les dirigeants ?

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    A linear CO chemistry parameterization in a chemistry-transport model: evaluation and application to data assimilation

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    This paper presents an evaluation of a new linear parameterization valid for the troposphere and the stratosphere, based on a first order approximation of the carbon monoxide (CO) continuity equation. This linear scheme (hereinafter noted LINCO) has been implemented in the 3-D Chemical Transport Model (CTM) MOCAGE (MOdèle de Chimie Atmospherique Grande Echelle). First, a one and a half years of LINCO simulation has been compared to output obtained from a detailed chemical scheme output. The mean differences between both schemes are about ±25 ppbv (part per billion by volume) or 15% in the troposphere and ±10 ppbv or 100% in the stratosphere. Second, LINCO has been compared to diverse observations from satellite instruments covering the troposphere (Measurements Of Pollution In The Troposphere: MOPITT) and the stratosphere (Microwave Limb Sounder: MLS) and also from aircraft (Measurements of ozone and water vapour by Airbus in-service aircraft: MOZAIC programme) mostly flying in the upper troposphere and lower stratosphere (UTLS). In the troposphere, the LINCO seasonal variations as well as the vertical and horizontal distributions are quite close to MOPITT CO observations. However, a bias of ~−40 ppbv is observed at 700 Pa between LINCO and MOPITT. In the stratosphere, MLS and LINCO present similar large-scale patterns, except over the poles where the CO concentration is underestimated by the model. In the UTLS, LINCO presents small biases less than 2% compared to independent MOZAIC profiles. Third, we assimilated MOPITT CO using a variational 3D-FGAT (First Guess at Appropriate Time) method in conjunction with MOCAGE for a long run of one and a half years. The data assimilation greatly improves the vertical CO distribution in the troposphere from 700 to 350 hPa compared to independent MOZAIC profiles. At 146 hPa, the assimilated CO distribution is also improved compared to MLS observations by reducing the bias up to a factor of 2 in the tropics. This study confirms that the linear scheme is able to simulate reasonably well the CO distribution in the troposphere and in the lower stratosphere. Therefore, the low computing cost of the linear scheme opens new perspectives to make free runs and CO data assimilation runs at high resolution and over periods of several years
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