Les sources archivistiques du thème chemins de fer et alimentation

Le Centre des archives historiques de la SNCF, partie intégrante du Service des Archives et de la Documentation, a ouvert ses portes au Mans en 1995. Depuis lors, il s’efforce de remplir les missions suivantes : collecte des archives historiques de la SNCF au niveau national, tri, classement, élaboration d’instruments de recherche et, bien sûr, communication des archives. Il a la particularité de conserver également un très riche fonds d’imprimés, d’ouvrages et de publications sérielles. La présente analyse se limite au domaine français et aux sources présentes au Centre du Mans, l’exposé des sources complémentaires restant à réaliser. Après avoir abordé les sources permettant une approche par les produits, elle traite l’action des chemins de fer pour limiter les pertes et les avaries par le biais des emballages et des méthodes de manutention. La question primordiale du ravitaillement de la population est ensuite évoquée, à travers les gares-marchés. Deux autres aspects du sujet sont la nécessité pour le chemin de fer d’assurer la conservation des denrées périssables par le biais d’installations frigorifiques et de mettre en service un matériel de transport adapté. La volonté d’améliorer les conditions de chargement et de déchargement et de réduire ainsi les coûts de manutention conduit au développement de l’utilisation de la palette, puis du conteneur, et à la mécanisation de la manutention. La chaîne qui relie le producteur au consommateur est analysée dans son détail, incluant les embranchements particuliers et les transports terminaux. En dernier lieu est présenté l’état des sources conservées par le Centre du Mans sur le thème de la restauration ferroviaire.The SNCF’s Center of Historical Archives, an integral part of the Services des Archives et de la Documentation, was opened in Le Mans in 1995. Since then it has undertaken the following missions: to assemble historical archives of the SNCF at the national level, to sort, classify, and develop research tools, and of course to make documents available to the public. As a special feature, it also preserves a large collection of printed material, monographs, and serial publications. The present study is limited to the French holdings and the sources found at the Centre du Mans; a presentation of ancillary sources remains to be done. After discussing sources which allow an approach by product, we study the measures taken by railways to limit loss and spoilage caused by packaging and handling methods. The fundamental issue of providing supplies to the population through “gares-marchés” (railway station-markets) is then raised. Two other aspects of the topic are the railway’s need to provide ways of preserving perishable merchandise using refrigerated installations and also implement proper transportation equipment. The desire to improve loading and unloading conditions and as a result reduce handling costs leads to developing the use of palettes and then containers and to the mechanization of handling. The chain connecting the producer to the consumer is analyzed in depth, including specific branch lines and terminal transportation. Finally we discuss the sources available at the centre du Mans on the topic of railway food service

Les sources pour écrire l’histoire des cheminots dans la Résistance

Mener une étude historique sur la résistance cheminote, quel que soit le périmètre géographique de l’enquête, représente un long travail. Il faut en effet se livrer à une exploitation systématique de toutes les sources écrites et figurées, sans oublier la collecte de témoignages ou le recours aux archives orales qui peuvent permettre d’accéder au « dessous des choses », aux cheminements. Au préalable, il peut être fort utile de se rapprocher des associations d’anciens résistants, par le biais..

Optimal Control of Saccades by Spatial-Temporal Activity Patterns in the Monkey Superior Colliculus

A major challenge in computational neurobiology is to understand how populations of noisy, broadly-tuned neurons produce accurate goal-directed actions such as saccades. Saccades are high-velocity eye movements that have stereotyped, nonlinear kinematics; their duration increases with amplitude, while peak eye-velocity saturates for large saccades. Recent theories suggest that these characteristics reflect a deliberate strategy that optimizes a speed-accuracy tradeoff in the presence of signal-dependent noise in the neural control signals. Here we argue that the midbrain superior colliculus (SC), a key sensorimotor interface that contains a topographically-organized map of saccade vectors, is in an ideal position to implement such an optimization principle. Most models attribute the nonlinear saccade kinematics to saturation in the brainstem pulse generator downstream from the SC. However, there is little data to support this assumption. We now present new neurophysiological evidence for an alternative scheme, which proposes that these properties reside in the spatial-temporal dynamics of SC activity. As predicted by this scheme, we found a remarkably systematic organization in the burst properties of saccade-related neurons along the rostral-to-caudal (i.e., amplitude-coding) dimension of the SC motor map: peak firing-rates systematically decrease for cells encoding larger saccades, while burst durations and skewness increase, suggesting that this spatial gradient underlies the increase in duration and skewness of the eye velocity profiles with amplitude. We also show that all neurons in the recruited population synchronize their burst profiles, indicating that the burst-timing of each cell is determined by the planned saccade vector in which it participates, rather than by its anatomical location. Together with the observation that saccade-related SC cells indeed show signal-dependent noise, this precisely tuned organization of SC burst activity strongly supports the notion of an optimal motor-control principle embedded in the SC motor map as it fully accounts for the straight trajectories and kinematic nonlinearity of saccades

Towards a co-design approach to digital device for learning

Contrary to predictions that information and communication technologies would get a new wind on innovative pedagogy blowing, current e-learning platforms have instead a binding effect on effective implementation. This observation is based on our experience with design of the Tandem Canada platform. The Tandem Canada Platform was elaborated to learn French and English in a tandem approach. With this platform, teachers can find a partner class and collaborate with it. Their students grouped in tandem can exchange by text, audio, video in a synchronous or asynchronous way. The platform is composed by different modules, specially the exchange space offers to teachers a technological and pedagogical support to make language learning in tandem. Because of its standard status, Moodle was chosen to implement the exchange space. Then, two difficulties emerged: structure of Moodle is too rigid and its functions are not customizable to support this innovative mode of teaching/learning. More generally, to develop a technological support to innovative pedagogy, the reality had to be twisted to give the closest match to the platform formalism. So, the obtained platform does not really correspond to the needs of the users, they have to adapt to the technology when it should be the other way around. We think it is important that all different users can build a conceptual model which reflects their needs, regardless the digital device. Today, there are user-centered propositions or development-based propositions to design digital devices for teaching/learning. Their design is still in the hands of e-learning platform developers. But how to obtain such conceptual models? How to do these models designed by non-programmers could be directly implemented? We propose a new approach allowing the users to conduct the design workshops. With this participatory approach, users become true co-designers of their own digital device for teaching/learning. This approach is called DEMOS for Design mEthod for demOcratic information System. The purpose is to involve future users in the design of their future system while respecting their viewpoints. The method is presented in the form of a MAP: a navigational structure with a selection of four intentions and strategies to achieve it. First, participants can express divergent visions about the pedagogical tool to be built. Secondly, this allows the emergence of different participants viewpoints on the future platform. Thirdly, the participants, grouped according to their viewpoint, can design their own pedagogical conceptual model. Lastly, the conceptual models are linked together by the participants, to get consolidated viewpoint models directly implementable in the future system. Thanks to various activities such as photolanguage, mind mapping, user stories writing, participants develop standardized conceptual models by always speaking in their current vocabulary. Through the application of this participatory approach to the Tandem Canada platform design, the paper aims to show how to facilitate a better translation of various viewpoints of the users on a conceptual model of the e-learning solution, model that could be directly implemented

Insights in the Architecture of Silicon-Based Plasma Polymers Using Partial Network Ethanolysis Combined with Electrospray Tandem Mass Spectrometry

International audienceThin films obtained upon plasma polymerization of D4 and HMDSO precursors at atmospheric pressure are submitted to controlled ethanolysis to produce oligomers amenable to electrospray mass spectrometry. When using high resolution mass spectrometry to assess their elemental composition and tandem mass spectrometry to characterize their end-groups, a whole set of ethanolysis products is identified, from which the network connectivity in the original film can be reconstructed. Ethanolysis products of ppD4 and ppHMDSO exhibit the same structural features composed of linear and cross-linked PDMS moieties, the extent of cross-linking reflecting the inorganic character of the film. Oligomers originally embedded in the solid network and released as intact species upon its dissolution are also observed. [GRAPHICS]

Comment developper l'autonomie des utilisateurs dans un projet de site Web de bibliotheque

Available from INIST (FR), Document Supply Service, under shelf-number : TM 625 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Electrospray tandem mass spectrometry combined with authentic compound synthesis for structural characterization of an octamethylcyclotetrasiloxane plasma polymer

International audienceElectrospray tandem mass spectrometry was used here to study the soluble part of a thin film prepared by plasma polymerization of octamethylcyclotetrasiloxane (D4). Accurate mass measurements and Si-29 nuclear magnetic resonance (NMR) spectroscopy, as well as synthesis of authentic compounds used as models to understand the MS/MS behavior of plasma polymers, were combined to structurally investigate oligomers present in this extract. All precursor ions were protonated or ammoniated molecules, known to provide more useful information for dimethylsiloxane (DMS)-based polymers as compared to alkali adducts. Apart from a major compound consisting of two D4 units connected via an oxygen bridge, it was found that the soluble part of this plasma polymer was mainly composed of cyclolinear polysiloxanes, in which cyclic units composed of four DMS were covalently connected by linear DMS segments. As the size of precursor ions increases, discrepancies observed between MS/MS data of synthesized molecules and of plasma oligomers would reveal the presence of branched isomers in the soluble part of the film, consistently with the expected propensity of the plasma polymerization process to favor random branching. (C) 2012 Elsevier B.V. All rights reserved

In vivo administration of a lentiviral vaccine targets DCs and induces efficient CD8(+) T cell responses

The present study evaluates the potential of third-generation lentivirus vectors with respect to their use as in vivo–administered T cell vaccines. We demonstrate that lentivector injection into the footpad of mice transduces DCs that appear in the draining lymph node and in the spleen. In addition, a lentivector vaccine bearing a T cell antigen induced very strong systemic antigen-specific cytotoxic T lymphocyte (CTL) responses in mice. Comparative vaccination performed in two different antigen models demonstrated that in vivo administration of lentivector was superior to transfer of transduced DCs or peptide/adjuvant vaccination in terms of both amplitude and longevity of the CTL response. Our data suggest that a decisive factor for efficient T cell priming by lentivector might be the targeting of DCs in situ and their subsequent migration to secondary lymphoid organs. The combination of performance, ease of application, and absence of pre-existing immunity in humans make lentivector-based vaccines an attractive candidate for cancer immunotherapy

Les cheminots dans la Résistance

À l’occasion de la première présentation, de décembre 2005 à avril 2006 au Mémorial Maréchal Leclerc de Hauteclocque et de la Libération de Paris, Musée Jean Moulin, de l’exposition Les Cheminots dans la Résistance réalisée par la Fondation de la Résistance, avec la participation et le soutien de la SNCF et en coopération avec l’Association pour l’histoire des chemins de fer en France, l’AHICF a réuni tous ceux qui font de la résistance des cheminots une histoire en évolution : auteurs et membres du comité historique de l’exposition, jeunes chercheurs, conservateurs d’archives et de musées en France et en Europe. Aux actes du colloque tenu le 3 décembre 2005 sont ajoutées d'importantes références – bibliographie critique, publication de documents inédits – pour les travaux futurs

Placental vascularity and resorption delay after conservative management of invasive placenta: MR imaging evaluation

International audienceOBJECTIVES:To assess the potential of magnetic resonance (MR) imaging in evaluating placental vascularity and predicting placental resorption delay after conservative management of invasive placenta.METHODS:MR examinations of 23 women with conservative management of invasive placenta were reviewed. Twelve women had pelvic embolisation because of postpartum haemorrhage (Group 1) and 11 had no embolisation (Group 2). Comparisons between the two groups were made with respect to the delay for complete placental resorption at follow-up MR imaging and degree of placental vascularity 24 h after delivery on early (30s) and late (180 s) phase of dynamic gadolinium chelate-enhanced MR imaging.RESULTS:The median delay for complete placental resorption in the cohort study was 21.1 weeks (range, 1-111 weeks). In Group 1, the median delay for complete placental resorption was shorter than in Group 2 (17 vs 32 weeks) (P = 0.036). Decreased placental vascularity on the early phase was observed in Group 1 by comparison with Group 2 (P = 0.003). Significant correlation was found between the degree of vascularity on early phase of dynamic MR imaging and the delay for complete placental resorption (r = 0.693; P < 0.001).CONCLUSIONS:MR imaging provides useful information after conservative management of invasive placenta and may help predict delay for complete placental resorption