16 research outputs found

    Méthode de libération d'une piÚce micromécanique et piÚce micromécanique comprenant des attaches sacrificielles

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    A method for fabricating a micromechanical part from a substrate in which the part is fabricated by providing a plurality of fasteners between the part and the substrate, the fasteners being sacrificial, characterized in that the fasteners include at least one hinge at the end of each fastener located beside the part, and in that the method includes a step of breaking the sacrificial fasteners. The micromechanical parts employing this type of sacrificial fastener are also described

    Development of a Space Bioreactor using Microtechnology

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    A miniature bio-reactor for the cultivation of cells aboard Spacelab is presented. Yeast cells are grown in a 3 milliliter reactor chamber. A supply of fresh nutrient medium is provided by a piezo-electric silicon micro-pump. In the reactor, pH, temperature, and redox potential are monitored and the pH is regulated at a constant value. The complete instrument is fitted in a standard experiment container of 63 x 63 x 85 mm. The bioreactor was used on the IML-2 mission in July 1994 and is being refurbished for a reflight in the spring of 1996

    Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions

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    Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6–20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale

    A simpliïŹed temperature model for the three way catalytic converter

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    International audienceA semi empirical model based on thermodynamic behaviour of a three way catalytic converter has been proposed to predict temperature evolution of the converter during the cold start. The model is based on energy and mass balance in the TWC considered as control volume. Parameters of the heat equations are identified separately using a step by step approach. Thermocouples have been inserted along the monolith canals to measure the axial evolution of temperature. Experiments on the engine test bench have been conducted to identify the parameters and to validate the model

    A simplified thermal model for the three way catalytic converter

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    TAP 2016, 21st International Transport and Air Pollution Conference, LYON, FRANCE, 24-/05/2016 - 26/05/2016A semi empirical model based on thermodynamic behaviour of a three way catalytic converter has been proposed to predict temperature evolution of the converter during the cold start. The model is based on energy and mass balance in the TWC considered as control volume. Parameters of the heat equations are identified separately using a step by step approach. Thermocouples have been inserted along the monolith canals to measure the axial evolution of temperature. Experiments on the engine test bench have been conducted to identify the parameters and to validate the model

    Synthesis of new pyrrolidine derivatives as inhibitors of alpha-mannosidase and of glioblastoma cells growth

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    New 2-benzylamino-3,4-dihydroxypyrrolidines bearing aromatic and aliphatic amido side chains have been prepared. The influence of the amido substituents on the inhibitory activity of these diamines toward 24 commercially available glycosidases was determined. The most potent and selective alpha-mannosidase inhibitor (6d) (N-[(2R)-2-({[(2R,3R,4S)-3,4-dihydroxypyrrolidin -2-yl]methyl} amino)-2-phenylethyl]-3-bromobenzamide) of these series was also the most potent inhibitor of the growth of human glioblastoma cells

    Simple Évaluation de TempĂ©rĂ© Prairie Pertinence comme Habitat pour Trois Insecte Taxons

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    International audienceWe propose a set of indicators to evaluate how grazing by livestock and grassland management can help preserve biodiversity in the insect communities of grassland ecosystems. These indicators can be calculated for any grassland for which management and botanical composition are known, and they do not require advanced knowledge on conservation biology and entomology. Based on the scientific literature and expert interviews, each indicator combines pressure (i.e., 16 management classes) and state variables (i.e., sward botanical composition and several of the plant functional characteristics) to assess the effects on butterfly, bumblebee, and grasshopper abundance and species richness. Each indicator was based on a multicriteria decision tree with fuzzy partitioning to account for uncertainty in the threshold values between different alternatives. The output validation of indicators was performed by comparing decision tree output with standardized measurements from 10 surveys across France, Germany, Switzerland, Wales, and Italy. The prediction of grassland suitability for butterflies was more accurate for butterfly species richness ( P &lt; 0.05) than for butterfly abundance ( P = 0.10), as even under standardized transect counts, recorders will observe disproportionately more individuals when it is sunny and warm. The sensitivity of the butterfly species richness indicator was then tested using an independent dataset of 395 French grasslands. There were significant differences in predicted species richness (χ 2 15 = 121.16; P &lt; 0.05) among the 16 management classes, and they were ranked consistently in spite of very parsimonious assumptions in the decision tree. The prediction of grassland suitability was good for bumblebee abundance ( P &lt; 0.05) and species richness ( P &lt; 0.01). This prediction was also successful for grasshopper abundance ( P &lt; 0.05) and species richness ( P = 0.05), all outliers coming from a highly diverse grassland community located on shallow soil in the Italian survey. This set of indicators can thus provide a cost-effective evaluation of temperate grassland suitability as habitat for three insect taxa. These indicators have more relevance than general insect species richness, and their application does not require any entomological skill. The indicators can help stakeholders to make adequate decisions for insect conservation in grassland ecosystems, but do not have direct applicability to higher conservation value taxa or species.Nous proposons un ensemble d'indicateurs pour Ă©valuer comment le pĂąturage par le bĂ©tail etprairiela gestion peut aider Ă  prĂ©server la biodiversitĂ© dans leinsectecommunautĂ©s deprairieĂ©cosystĂšmes. Ces indicateurs peuvent ĂȘtre calculĂ©s pour toutprairiedont la gestion et la composition botanique sont connues et qui ne nĂ©cessitent pas de connaissances avancĂ©es en biologie de la conservation et en entomologie. Sur la base de la littĂ©rature scientifique et d'entretiens avec des experts, chaque indicateur combine des variables de pression (c'est-Ă -dire 16 classes de gestion) et d'Ă©tat (c'est-Ă -dire la composition botanique du gazon et plusieurs des caractĂ©ristiques fonctionnelles de la plante) pour Ă©valuer les effets sur l'abondance des papillons, des bourdons et des sauterelles et richesse en espĂšces. Chaque indicateur Ă©tait basĂ© sur un arbre dĂ©cisionnel multicritĂšres avec un partitionnement flou pour tenir compte de l'incertitude sur les valeurs seuils entre diffĂ©rentes alternatives. La validation des rĂ©sultats des indicateurs a Ă©tĂ© effectuĂ©e en comparant les rĂ©sultats de l'arbre dĂ©cisionnel avec les mesures standardisĂ©es de 10 enquĂȘtes en France, en Allemagne, en Suisse, au Pays de Galles et en Italie. La prĂ©diction deprairie pertinencepour les papillons Ă©tait plus prĂ©cise pour la richesse spĂ©cifique des papillons (P < 0,05) que pour l'abondance des papillons (P = 0,10),commemĂȘme avec des comptages de transects standardisĂ©s, les enregistreurs observeront de maniĂšre disproportionnĂ©e plus d'individus lorsqu'il fait chaud et ensoleillĂ©. La sensibilitĂ© de l'indicateur de richesse spĂ©cifique des papillons a ensuite Ă©tĂ© testĂ©e Ă  l'aide d'un jeu de donnĂ©es indĂ©pendant de 395 prairies françaises. Il y avait des diffĂ©rences significatives dans la richesse spĂ©cifique prĂ©vue (χ 2 15 = 121,16 ; P < 0,05) parmi les 16 classes de gestion, et elles ont Ă©tĂ© classĂ©es de maniĂšre cohĂ©rente malgrĂ© des hypothĂšses trĂšs parcimonieuses dans l'arbre de dĂ©cision. La prĂ©diction deprairie pertinenceĂ©tait bon pour l'abondance des bourdons (P < 0,05) et la richesse spĂ©cifique (P < 0,01). Cette prĂ©diction a Ă©galement rĂ©ussi pour l'abondance des sauterelles (P < 0,05) et la richesse spĂ©cifique (P = 0,05), toutes les valeurs aberrantes provenant d'un environnement trĂšs diversifiĂ©.prairiecommunautĂ© situĂ©e sur un sol peu profond dans l'enquĂȘte italienne. Cet ensemble d'indicateurs peut donc fournir une Ă©valuation rentable detempĂ©rĂ© prairie pertinence comme habitatpourTrois insecte taxons. Ces indicateurs sont plus pertinents que les indicateurs gĂ©nĂ©rauxinsecterichesse spĂ©cifique, et leur application ne nĂ©cessite aucune compĂ©tence entomologique. Les indicateurs peuvent aider les parties prenantes Ă  prendre des dĂ©cisions adĂ©quates pourinsecteconservation dansprairieĂ©cosystĂšmes, mais n'ont pas d'applicabilitĂ© directe Ă  une valeur de conservation plus Ă©levĂ©etaxonsou espĂšce. Copyright © 2022 Dumont, Rossignol, Huguenin-Elie, Jeanneret, Jerrentrup, LĂŒscher, Taugourdeau, Villerd et Plantureux

    Le musée et le politique

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    Tout au long du XIXe siĂšcle et du premier XXe siĂšcle, le musĂ©e s'est inscrit dans un ensemble de pratiques de contrĂŽle, social et moralisateur : il devait consolider les vertus publiques et travailler Ă  la prospĂ©ritĂ© industrieuse. Le musĂ©e s’inscrivait aussi dans le jeu des rivalitĂ©s internationales, autant dans la crainte de dĂ©perditions patrimoniales que dans la compĂ©tition autour de nouvelles collections Ă  former. Mais Ă  partir des annĂ©es 1960 et 1970 cet idĂ©al a Ă©tĂ© de plus en plus vivement contestĂ©. On a voulu mettre au jour les agendas politiques cachĂ©s de l’institution en montrant ses liens avec les pouvoirs, politiques, industriels, financier, et en cultivant au contraire les utopies d’un musĂ©e forum. La musĂ©ologie nouvelle entretient alors des liens Ă©troits avec la rĂ©flexion politique et les thĂ©ories sociales, le dĂ©veloppement de nouveaux savoirs – l’écologie, les Ă©tudes matĂ©rielles, l’anthropologie –, aussi bien qu’avec le postcolonialisme et le multiculturalisme. La « politique du musĂ©e » est, au sein des dĂ©mocraties contemporaines, une catĂ©gorie ou un sous-ensemble de politiques culturelles plus gĂ©nĂ©rales. De nouveaux musĂ©es nationaux tĂ©moignent de la rĂ©Ă©criture des thĂšmes traditionnels de l’État, de la nation et des identitĂ©s, tandis qu’à l’inverse des musĂ©es de « de l’Europe » ou du monde et de l’histoire globale tentent de proposer un rĂ©cit. Les mises en scĂšne et les choix des expĂŽts peuvent susciter de vives polĂ©miques, capables de conduire Ă  l’annulation de la manifestation, la fermeture de l’institution ou l’échec de sa fondation. Les processus de collectionnisme et d’interprĂ©tation peuvent faire l’objet de propositions participatives dans une visĂ©e de dĂ©mocratie directe. Des pressions, liĂ©es Ă  des populismes ou Ă  des groupes d’influence, sur la possession et la disposition des collections remettent en cause des organisations qui paraissaient rĂ©glĂ©es naguĂšre par un consensus sur les compĂ©tences professionnelles de la conservation. Ce numĂ©ro propose un panorama des configurations qui, depuis plus de deux siĂšcles, articulent le musĂ©e et la politique. Throughout the 19th and early 20th centuries, museums were part of a system of moral and social control: they were intended to consolidate public virtues and to work towards industrious prosperity. Museums were also a part of global rivalries, as much out of a fear of cultural perdition as part of a competition surrounding new types of collections to be amassed. This ideal, however, began to be more and more contested in the 1960s and 70s. There was a desire to reveal the hidden political agendas of museum, tied to political, industrial and financial powers, and to instead cultivate the utopia of the museum as a forum. New museology thus maintains close ties to political considerations and social theories, the development of new fields (such as ecology, material studies and anthropology) as well as postcolonial and multicultural studies. Within modern democracies, “museum policy” is a category or subsection of more general cultural policies. New national museums testify to the rewriting of traditional themes such as the State, the nation and identities, while on the contrary “European”, world or global history museums attempt to propose new narratives. The staging and choice of exhibitions can provoke strong debates, leading in some cases to an event’s cancellation, the closing of an institution or one’s ultimate failure to open. Processes of collection and interpretation can be opened up to wider participation with the aim of cultivating a sort of direct democracy. Pressure, linked to certain populist groups or lobbies, surrounding the acquisition and organization of certain types of collections can shed doubt on the very existence of an institution whose survival seemed approved by general consensus concerning the professional capabilities of curators and conservators. This is issue proposes a panorama of the variety of configurations that have, for the past two hundred years, linked museums and policy
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