1,105 research outputs found

    Links between production systems and transport : the example of German and French industries

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    Changes in transportation are closely linked to the economic and logistical characteristics of the production system. The aim of this paper is, on the basis of data on the economic context and surveys conducted in France (the 1988 Shipper survey and the 2004 ECHO survey) and in Germany (the 2005 DLR survey), to show the major changes that have occurred in the two countries at both micro- and macro-economic levels and how these have affected transport demand. The first level of analysis relates to changes in the economic fabric. In particular, we have demonstrated the growing proportion of small and medium-sized firms at a time when large production units, which are those that are best able to concentrate their freight and use modes other than the road, are becoming fewer and fewer. At the same time, economic links are becoming more complex and, in the case of France, we have shown the increasing role played by wholesale traders in the distribution of goods. The constant reduction in transport costs and the opening up of markets is another structural factor whose impacts in both France and Germany we have also analysed. In addition to these economic changes, the internal modes of production of firms have also changed. Production is becoming more diversified and Just-in-time practices are spreading. The fragmentation of freight flows is thus occurring both in space and in time, which also has a major effect on the characteristics of the flows generated by firms and changes in transport. In the case of all these changes we have attempted to show the differences and similarities between the ways transport has changed in the two countries.TRANSPORT DE MARCHANDISES ; ALLEMAGNE ; FRANCE

    The influence of snow sublimation and meltwater evaporation on δD of water vapor in the atmospheric boundary layer of central Europe

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    Post-depositional fractionation of stable water isotopes due to fractionating surface evaporation introduces uncertainty to various isotope applications such as the reconstruction of paleotemperatures, paleoaltimetry, and the investigation of groundwater formation. In this study, we investigate isotope fractionation at snow-covered moisture sources by combining 17 months of observations of isotope concentration ratios [HD16O] ∕ [H216O] in low-level water vapor in central Europe with a new Lagrangian isotope model. The isotope model is capable of reproducing variations of the observed isotope ratios with a correlation coefficient R of 0.82. Observations from 38 days were associated with cold snaps and moisture uptake in snow-covered regions. Deviations between modeled and measured isotope ratios during the cold snaps were related to differences in skin temperatures (Tskin). Analysis of Tskin provided by the Global Data Assimilation System (GDAS) of the NCEP implies the existence of two regimes of Tskin with different types of isotope fractionation during evaporation: a cold regime with Tskin < Tsubl,max = −7.7 °C, which is dominated by non-fractionating sublimation of snow, and a warmer regime with Tsubl,max < Tskin < 0 °C, which is dominated by fractionating evaporation of meltwater. Based on a sensitivity study, we assess an uncertainty range of the determined Tsubl,max of −11.9 to −2.9 °C. The existence of the two fractionation regimes has important implications for the interpretation of isotope records from snow-covered regions as well as for a more realistic modeling of isotope fractionation at snow-covered moisture sources. For these reasons, more detailed experimental studies at snow-covered sites are needed to better constrain the Tsubl,max and to further investigate isotope fractionation in the two regimes

    Ray splitting in paraxial optical cavities

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    We present a numerical investigation of the ray dynamics in a paraxial optical cavity when a ray splitting mechanism is present. The cavity is a conventional two-mirror stable resonator and the ray splitting is achieved by inserting an optical beam splitter perpendicular to the cavity axis. We show that depending on the position of the beam splitter the optical resonator can become unstable and the ray dynamics displays a positive Lyapunov exponent.Comment: 13 pages, 7 figures, 1 tabl

    Genome-wide analysis of cell wall-related genes in Tuber melanosporum

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    A genome-wide inventory of proteins involved in cell wall synthesis and remodeling has been obtained by taking advantage of the recently released genome sequence of the ectomycorrhizal black truffle. Genes that encode cell wall biosynthetic enzymes, enzymes involved in cell wall polysaccharide synthesis or modification, GPI-anchored proteins and other cell wall proteins were identified in the black truffle genome. As a second step, array data were validated and the symbiotic stage was chosen as the main focus. Quantitative RT-PCR experiments were performed on 29 selected genes to verify their expression during ectomycorrhizal formation. The results confirmed the array data, and this suggests that cell wall-related genes are required for morphogenetic transition from mycelium growth to the ectomycorrhizal branched hyphae. Labeling experiments were also performed on mycelium and ectomycorrhizae to localize cell wall components

    Virtual faces as a tool to study emotion recognition deficits in schizophrenia

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    Studies investigating emotion recognition in patients with schizophrenia predominantly presented photographs of facial expressions. Better control and higher flexibility of emotion displays could be afforded by virtual reality (VR). VR allows the manipulation of facial expression and can simulate social interactions in a controlled and yet more naturalistic environment. However, to our knowledge, there is no study that systematically investigated whether patients with schizophrenia show the same emotion recognition deficits when emotions are expressed by virtual as compared to natural faces. Twenty schizophrenia patients and 20 controls rated pictures of natural and virtual faces with respect to the basic emotion expressed (happiness, sadness, anger, fear, disgust, and neutrality). Consistent with our hypothesis, the results revealed that emotion recognition impairments also emerged for emotions expressed by virtual characters. As virtual in contrast to natural expressions only contain major emotional features, schizophrenia patients already seem to be impaired in the recognition of basic emotional features. This finding has practical implication as it supports the use of virtual emotional expressions for psychiatric research: the ease of changing facial features, animating avatar faces, and creating therapeutic simulations makes validated artificial expressions perfectly suited to study and treat emotion recognition deficits in schizophrenia

    Rethinking drug design in the artificial intelligence era

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    Artificial intelligence (AI) tools are increasingly being applied in drug discovery. While some protagonists point to vast opportunities potentially offered by such tools, others remain sceptical, waiting for a clear impact to be shown in drug discovery projects. The reality is probably somewhere in-between these extremes, yet it is clear that AI is providing new challenges not only for the scientists involved but also for the biopharma industry and its established processes for discovering and developing new medicines. This article presents the views of a diverse group of international experts on the 'grand challenges' in small-molecule drug discovery with AI and the approaches to address them

    Enabling quantitative data analysis through e-infrastructures

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    This paper discusses how quantitative data analysis in the social sciences can engage with and exploit an e-Infrastructure. We highlight how a number of activities which are central to quantitative data analysis, referred to as ‘data management’, can benefit from e-infrastructure support. We conclude by discussing how these issues are relevant to the DAMES (Data Management through e-Social Science) research Node, an ongoing project that aims to develop e-Infrastructural resources for quantitative data analysis in the social sciences

    High-throughput full-automatic synchrotron-based tomographic microscopy

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    The automatization tools for high-throughput tomographic microscopy developed at the TOMCAT beamline of the Swiss Light Source are describe
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