183 research outputs found

    Saint Nicolas-de-Bourgueuil – Les caves de la Gardière

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    Date de l'opération : 1984 (SD) Inventeur(s) : Lecompte Jean-Paul ; Boucher M A la suite du déblaiement d'une cave, un grand nombre de fragments de céramique furent récupérés par le propriétaire. En 1984, un relevé stratigraphique fut réalisé dans une petite partie du remblai qui paraît dater du XVe et du XVIe s

    L'innovation, condition de la pérennité des systèmes agroalimentaires localisés

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    La production agroalimentaire artisanale et les produits de terroir ont bien souvent une image traditionnelle, celle de pratiques figées dans le temps, transmises de génération en génération. L'analyse montre au contraire des systèmes agroalimentaires localisés (Syal) confrontés à des besoins permanents d'innovation, pour faire face à des évolutions internes (réduction de la capacité de coordination et d'action collective) et/ ou externes (nouvelles contraintes ou opportunités techniques ou commerciales). Face à ces besoins, certains systèmes sont à même d'instaurer des interactions accrues entre acteurs locaux et acteurs extra-locaux, débouchant sur des innovations techniques ou organisationnelles. Le concept de Syal permet alors d'éclairer bien mieux ces processus d'innovation collectifs et localisés que ne le font les schémas diffusionnistes, et de mettre aussi en évidence les voies d'appui

    Soliton Lattices in the Incommensurate Spin-Peierls Phase: Local Distortions and Magnetizations

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    It is shown that nonadiabatic fluctuations of the soliton lattice in the spin-Peierls system CuGeO_3 lead to an important reduction of the NMR line widths. These fluctuations are the zero-point motion of the massless phasonic excitations. Furthermore, we show that the discrepancy of X-ray and NMR soliton widths can be understood as the difference between a distortive and a magnetic width. Their ratio is controlled by the frustration of the spin system. By this work, theoretical and experimental results can be reconciled in two important points.Comment: 9 pages, 5 figures included, Revtex submitted to Physical Review

    Chapitre 6 - L’innovation, condition de la pérennité des systèmes agroalimentaires localisés

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    Résumé. La production agroalimentaire artisanale et les produits de terroir ont bien souvent une image traditionnelle, celle de pratiques figées dans le temps, transmises de génération en génération. L’analyse montre au contraire des systèmes agroalimentaires localisés (Syal) confrontés à des besoins permanents d’innovation, pour faire face à des évolutions internes (réduction de la capacité de coordination et d’action collective) et/ou externes (nouvelles contraintes ou opportunités techniques ou commerciales). Face à ces besoins, certains systèmes sont à même d’instaurer des interactions accrues entre acteurs locaux et acteurs extra-locaux, débouchant sur des innovations techniques ou organisationnelles. Le concept de Syal permet alors d’éclairer bien mieux ces processus d’innovation collectifs et localisés que ne le font les schémas diffusionnistes, et de mettre aussi en évidence les voies d’appui

    Aerosol indirect effects

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    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (tau a) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. cloud droplet number concentration (N d) compares relatively well to the satellite data at least over the ocean. The relationship between (tau a) and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (fcld) and tau a as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld–tau a relationship, our results indicate that none can be identified as a unique explanation. Relationships similar to the ones found in satellite data between tau a and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - tau a relationship show a strong positive correlation between tau a and fcld. The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of tau a, and parameterisation assumptions such as a lower bound on Nd. Nevertheless, the strengths of the statistical relationships are good predictors for the aerosol forcings in the models. An estimate of the total short-wave aerosol forcing inferred from the combination of these predictors for the modelled forcings with the satellite-derived statistical relationships yields a global annual mean value of −1.5±0.5Wm−2. In an alternative approach, the radiative flux perturbation due to anthropogenic aerosols can be broken down into a component over the cloud-free portion of the globe (approximately the aerosol direct effect) and a component over the cloudy portion of the globe (approximately the aerosol indirect effect). An estimate obtained by scaling these simulated clearand cloudy-sky forcings with estimates of anthropogenic tau a and satellite-retrieved Nd–tau a regression slopes, respectively, yields a global, annual-mean aerosol direct effect estimate of −0.4±0.2Wm−2 and a cloudy-sky (aerosol indirect effect) estimate of −0.7±0.5Wm−2, with a total estimate of −1.2±0.4Wm−2

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Depressive symptoms and alcohol correlates among Brazilians aged 14 years and older: a cross-sectional study

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    Abstract\ud \ud Background\ud The associations between depressive symptoms and alcohol-related disorders, drinking patterns and other characteristics of alcohol use are important public health issues worldwide. This study aims to study these associations in an upper middle-income country, Brazil, and search for related socio-demographic correlations in men and women.\ud \ud \ud Methods\ud A cross-sectional study was conducted between November 2005 and April 2006. The sample of 3,007 participants, selected using a multistage probabilistic sampling method, represents the Brazilian population aged 14 and older. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale and alcohol dependence was assessed using the Composite International Diagnostic Interview. Associations assessed using bi-variate analysis were tested using Rao-Scott measures. Gender specific multinomial logistic regression models were developed.\ud \ud \ud Results\ud Among the participants with alcohol dependence, 46% had depressive symptoms (17.2% mild/moderate and 28.8% major/severe; p < 0.01); 35.8% (p = 0.08) of those with alcohol abuse and 23.9% (p < 0.01) of those with a binge-drinking pattern also had depressive symptoms. Alcohol abstainers and infrequent drinkers had the highest prevalence of major/severe depressive symptoms, whereas frequent heavy drinkers had the lowest prevalence of major/severe depressive symptoms. In women, alcohol dependence and the presence of one or more problems related to alcohol consumption were associated with higher risks of major/severe depressive symptoms. Among men, alcohol dependence and being ≥45 years old were associated with higher risks of major/severe depressive symptoms.\ud \ud \ud Conclusions\ud In Brazil, the prevalence of depressive symptoms is strongly related to alcohol dependence; the strongest association was between major/severe depressive symptoms and alcohol dependence in women. This survey supports the possible association of biopsychosocial distress, alcohol consumption and the prevalence of depressive symptoms in Brazil. Investing in education, social programs, and care for those with alcohol dependence and major/severe depressive symptoms, especially for such women, and the development of alcohol prevention policies may be components of a strategic plan to reduce the prevalence of depression and alcohol problems in Brazil. Such a plan may also promote the socio-economic development of Brazil and other middle-income countries.Brazilian National Secretariat on Drug Policies (SENAD) [grant number 017/2003]
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