436 research outputs found

    Des bibliothèques inclusives

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    De lintégration à linclusion, le pas franchi est celui qui traduit dans les pratiques avec les publics la révolution copernicienne qui a bouleversé la bibliothéconomie en plaçant les usagers « au centre ». Sa mission émancipatrice passe désormais par la co-construction des services

    Sources of dissolved organic matter during storm and inter-storm conditions in a lowland headwater catchment: constraints from high-frequency molecular data

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    International audienceThe transfer of dissolved organic matter (DOM) at soil–river interfaces controls the biogeochemistry of mi-cropollutants and the equilibrium between continental and oceanic C reservoirs. Understanding the mechanisms controlling this transfer is fundamental to ecology and geochem-istry. DOM delivery to streams during storms is assumed to come from the flushing of preexisting soil DOM reservoirs mobilized by the modification of water flow paths. We tested this hypothesis by investigating the evolution of the composition of stream DOM during inter-storm conditions and five storm events monitored with high-frequency sampling. The composition of DOM was analyzed using thermally assisted hydrolysis and methylation (THM) with tetramethylammo-nium hydroxide (TMAH) coupled to a gas chromatograph and mass spectrometer. In inter-storm conditions, stream DOM is derived from the flushing of soil DOM, while during storm events, the modification of the distribution of chemical biomarkers allows the identification of three additional mechanisms. The first one corresponds to the destabilization of microbial biofilms due to the increase in water velocity, resulting in the fleeting export of a microbial pool. The second mechanism corresponds to the erosion of soils and river banks, leading to a partition of organic matter between particulate and dissolved phases. The third mechanism is linked to the increase in water velocity in soils that could induce the erosion of macropore walls, leading to an in-soil partition between soil microparticles and dissolved phase. The contribution of this in-soil erosive process would be linked to the magnitude of the hydraulic gradient following the rise of the water table and could persist after the recession, which could explain why the return to inter-storm composition of DOM does not follow the same temporal scheme as the discharge. These results are the most important factors in understanding the transfer of nutrients and micropollutants at the soil–river interfaces during the hot moments that are storm events

    Hydrodynamical Simulations of the Lyman Alpha Forest: Model Comparisons

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    We investigate the properties of the Lyman alpha forest as predicted by numerical simulations for a range of currently viable cosmological models. This is done in order to understand the dependencies of the forest on cosmological parameters. Focusing on the redshift range from two to four, we show that: (1) most of the evolution in the distributions of optical depth, flux and column density can be understood by simple scaling relations, (2) the shape of optical depth distribution is a sensitive probe of the amplitude of density fluctuations on scales of a few hundred kpc, (3) the mean of the b distribution (a measure of the width of the absorption lines) is also very sensitive to fluctuations on these scales, and decreases as they increase. We perform a preliminary comparison to observations, where available. A number of other properties are also examined, including the evolution in the number of lines, the two-point flux distribution and the HeII opacity.Comment: 37 pages, 21 figures, submitted to Ap

    Didactique de l’écriture en situation de raccrochage scolaire : une entrée par les compétences. Un début d’étude collaborative au micro lycée de Paris

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    International audienceDidactique de l'écriture en situation de raccrochage : une entrée par les compétences ? Un début d'étude collaborative au micro-lycée de Paris Régine Delamotte, Marie-Claude Penloup et Anne-Marie Petitjean, université de Rouen La question du passage à l'écriture s'avère peu traitée dans les travaux actuels sur le décrochage scolaire alors même que les enseignants des micro-lycées d'Évreux et de Paris ont une demande explicite concernant les difficultés que rencontrent leurs élèves pour passer à l'écriture acadé-mique, en même temps d'ailleurs qu'ils soulignent leurs compétences en écriture créative. Pour répondre à cette demande, l'étude diagnostique que nous présentons s'appuie sur des données diverses : observations, enquêtes auprès des acteurs, textes produits lors d'une séance d'écriture créative. Cet ensemble est construit à partir de positions théoriques sociolinguistiques et (so-cio)didactiques qui seront rappelées. Il nous amène à mettre en évidence l'existence effective de compétences en écriture créative chez les élèves du micro-lycée et à en évaluer les enjeux pour la didactique

    Secondary prevention of cardiovascular diseases : targeting all the cardiovascular risk factors.

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    editorial reviewedThis article focuses on the secondary prevention of cardiovascular (CV) diseases, namely the prevention of recurrence in subjects with a personal history of CV event, and the prevention of a first event in patients identified as at very high risk. For all these patients at very high risk, treatment is primarily based on the application of hygienic and dietary measures, including increasing the volume of physical activity, modifying the diet, and obtaining, if necessary, weight loss, as well as stopping smoking. This strategy has proven its benefits in terms of reducing morbidity and mortality. In addition, these patients must receive pharmacological treatment, whose the additional benefits are proven. The article details the pharmacological classes that are currently recommended, as well as the optimal management of CV risk factors and the therapeutic targets to be achieved

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected
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