14,533 research outputs found
Changing nature and sustainability of the industrial district model : the case of Technic Valley in France
This paper examines the impact of contemporary pressures on industrial districts and analyses the changes that are taking place in an industrial district confronted with disembedding and globalization. We discuss the following questions: what are the processes and consequences of disembedding for the changing shape and form of inter-firm trust, contract and network forms? Is there an evolution in subcontracting and trade interdependency? What is the role of institutional infrastructures? We performed a longitudinal qualitative study using a number of different data sources to analyse the evolution of one French industrial district, particularly how new pressures of internationalization and disembedding work to reconfigure inter-firm relations in this district. While the recent literature is dominated by notions about industrial districts that concern only the trend towards increased competition or disembeddedness, this article shows that there is no unilinear trend. In contrast with the findings of certain recent studies, we argue that economic logic does not fully account for recent developments since the adjustment that are being made by the district are characterized rather by re-embeddedness, increased cooperation and institutionalization.industrial district, globalization, economic sociology
A multiplex quantitative real time PCR to detect Xanthomonas axonopodis pv.allii from onion seeds : [P2-26]
Bacterial blight of onion is a seed-borne emerging disease threatening world onion production, and causing damage to other Allium crops. Its causal agent, #Xanthomonas axonopodis pv. Allii# (Xaa) is listed in quarantine European and Mediterranean Protection Plant Organization (EPPO) A1 list since 2009. The development of a reliable tool is necessary to manage Xaa spreading via international seed trade. We developed a triplex quantitative real-time PCR capable of detecting Xaa using the Taqman® technology. This quantitative PCR targets two markers specific from Xaa (1) and an internal control chosen in NADH dehydrogenase from Alliaceae. The multiplex real-time PCR was assayed on a large collection of Xaa strains isolated worldwide and pathogenic to onion or to other Allium species. Xaa strains were detected by the amplification of one or both of the two specific markers. In case of poor or no amplification of these Xaa markers, the internal control signal validates both the extraction process and the reaction itself. Specificity was assayed on 80 Xaa strains, and 120 non target strains belonging to other #X. axonopodis# pathovars including strains from the same #X. axonopodis# subgroup 9.2 sensu Rademaker, other species, other genera, and saprophytic strains isolated from onion seed and plants. We obtained standard curves with high correlation coefficients (r2> 0,99) and amplification efficiencies of more than 90% on bacterial suspension (107 to 103 CFU/ml), and efficiencies of more than 80% from seed macerate, allowing the detection of 5.103 to 5.107 CFU/g for seed artificially inoculated with Xaa strains. We successfully detected both bacterial DNA and internal control DNA from plant by performing two successive steps: homogenization of a seed macerate with a stomacher®, followed by DNA extraction using DNeasy Plant minikit (Qiagen). We are currently validating our assay on naturally contaminated seed lots. This tool would be useful for the international sanitary surveillance of seed exchanges. (Résumé d'auteur
Short-term memory effects of an auditory biofeedback on isometric force control: Is there a differential effect as a function of transition trials?
The aim of the present study was to investigate memory effects, force
accuracy, and variability during constant isometric force at different force
levels, using auditory biofeedback. Two types of transition trials were used: a
biofeedback-no biofeedback transition trial and a no biofeedback-biofeedback
transition trial. The auditory biofeedback produced a low- or high-pitched
sound when participants produced an isometric force lower or higher than
required, respectively. To achieve this goal, 16 participants were asked to
produce and maintain two different isometric forces (305% and 90N5%)
during 25s. Constant error and standard deviation of the isometric force were
calculated. While accuracy and variability of the isometric force varied
according to the transition trial, a drift of the force appeared in the no
biofeedback condition. This result suggested that the degradation of
information about force output in the no biofeedback condition was provided by
a leaky memory buffer which was mainly dependent on the sense of effort.
Because this drift remained constant whatever the transition used, this memory
buffer seemed to be independent of short-term memory processes.Comment: Human Movement Science (2011) epub ahead of prin
Paramètres de détermination de la stabilité des déchets. Comparaison de différents modes de gestion des déchets non dangereux
National audienceLes déchets non dangereux, déchets ménagers et déchets industriels banals, sont généralement incinérés ou enfouis en centres de stockage anciennement dits de " classe II ". La gestion de ces centres de stockage répond à des critères très précis, tant au cours de l'exploitation qu'après l'arrêt de celle-ci. En particulier, un suivi des sites fermés est imposé pendant 30 ans, période pendant laquelle la matière organique, contenue dans les déchets, produit par dégradation biologique d'importantes quantités de biogaz et des lixiviats chargés. A côté de ce mode de stockage " classique ", il est apparu depuis quelques années des modes de gestion différents, qui visent à limiter les émissions gazeuses et liquides des déchets enfouis. Il s'agit d'une part, du fonctionnement de CSD en casiers de type bioréacteur, et d'autre part de l'enfouissement de déchets pré-traités biologiquement. A ces nouveaux modes de gestion s'ajoutent le tri en amont avec les collectes sélectives, et un traitement mécanique plus ou moins poussé avant le traitement biologique, permettant de diminuer la part de produits recyclables ou inertes, de rendre plus accessible la matière organique contenue dans les déchets, et d'homogénéiser la matrice
Risk assessment and comparison of short-term and long-term emissions for different treatment and disposal phases of MSW
International audienceA research program including a comparison between short term and long term emissions of MSW landfill started in 2006. The goal of that program was to access the human health chronic risk of three different waste disposal processes (anaerobic with/without leachate recirculation, with/without aerobic pretreatment) and to provide new criteria for the disposal site. A methodological approach using both calibration of the short term fluxes by in situ measurements and the prediction of long term fluxes by the use of exponential decreasing functions was explored. The identification of contaminant species was made by qualitative and quantitative concentration measurements done in a first stage on the landfill gas, and the collection of chemical leachate load measurements. At this stage of the study, the work did not show specific chemical contaminant species for the different waste disposal
L'oxydation du biogaz : un moyen de réduire les émissions résiduelles
National audienceDepuis le début des années 2000, plusieurs facteurs concourent au besoin de développement de nouveaux modes de gestion des déchets municipaux. Parmi ces nouveaux modes de gestion, la filière de traitement mécanobiologique (TMB) permet de réduire très significativement les émissions résiduelles de biogaz. Les émissions de carbone sous forme de biogaz constituent en effet la très grande majorité des émissions de carbone des déchets enfouis, quelque soit la filière retenue (filière conventionnelle, bioréacteur, TMB)
Structural Agnostic Modeling: Adversarial Learning of Causal Graphs
A new causal discovery method, Structural Agnostic Modeling (SAM), is
presented in this paper. Leveraging both conditional independencies and
distributional asymmetries in the data, SAM aims at recovering full causal
models from continuous observational data along a multivariate non-parametric
setting. The approach is based on a game between players estimating each
variable distribution conditionally to the others as a neural net, and an
adversary aimed at discriminating the overall joint conditional distribution,
and that of the original data. An original learning criterion combining
distribution estimation, sparsity and acyclicity constraints is used to enforce
the end-to-end optimization of the graph structure and parameters through
stochastic gradient descent. Besides the theoretical analysis of the approach
in the large sample limit, SAM is extensively experimentally validated on
synthetic and real data
Quality of composts from municipal biodegradable waste of different origins
International audienceMechanical biological treatment of municipal solid waste is increasing rapidly inaFrance as well as in other European countries. One of the outputs of this treatment is a compost prepared from the organic matter of the waste. This organic matter can be either collected selectively from the customers as biowaste, or separated from the total MSW in the plant. Unlike in Germany or Austria, where only the compost from selective collection of biowaste is allowed to serve as an amendment, in France the use of the compost is based on its compliance to a quality Standard. We present here the first results on an enquiry concerning the quality of composts from the two processes, determined on 5 French plants, between 2008 and now. All the composts fulfill to the prescriptions of the Standard and can be used as soil amendments
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