Reconstruction of longitudinal electrons bunch profiles at FACET, SLAC

Work supported by funding from Universite Paris Sud, program "Attractivite" and by the ANR under contract ANR-12-JS05-0003-01 - http://accelconf.web.cern.ch/AccelConf/IPAC2014/papers/thpme093.pdfInternational audienceThe E-203 collaboration is testing a device on FACET at SLAC to measure the longitudinal profile of electron bunches using Smith-Purcell radiation [1]. At FACET the electron bunches have an energy of 20 GeV and a duration of a few hundred femtoseconds [2]. Smith-Purcell radiation is emitted when a charged particle passes close to the sur- face of a metallic grating. We have studied the stability of the measurement from pulse to pulse and the resolution of the measure depending on the number of gratings used

Optimal design of thermally stable proteins

Motivation: For many biotechnological purposes, it is desirable to redesign proteins to be more structurally and functionally stable at higher temperatures. For example, chemical reactions are intrinsically faster at higher temperatures, so using enzymes that are stable at higher temperatures would lead to more efficient industrial processes. We describe an innovative and computationally efficient method called Improved Configurational Entropy (ICE), which can be used to redesign a protein to be more thermally stable (i.e. stable at high temperatures). This can be accomplished by systematically modifying the amino acid sequence via local structural entropy (LSE) minimization. The minimization problem is modeled as a shortest path problem in an acyclic graph with nonnegative weights and is solved efficiently using Dijkstra's method

Usages du vélo et rapports aux espaces publics des enfants : permanence de la division par sexe dans un dispositif d’apprentissage dans un quartier populaire à Strasbourg

Cadre de la recherche : Dans les quartiers prioritaires de la Politique de la Ville en France, les activités physiques, qu’elles soient effectuées dans un cadre de déplacement ou de loisirs, restent en retrait par rapport au territoire français dans son ensemble. Si de multiples travaux analysent les activités physiques et sportives chez les jeunes, voire les adultes, les pratiques des enfants demeurent un point aveugle. Les enfances pauvres méritent pourtant un regard spécifique, particulièrement leurs rapports à l’espace public. Dans cette optique, la littérature scientifique insiste sur les mobilités indépendantes et sur les contraintes familiales, notamment chez les filles. Objectifs : Il s’agit d’interroger les rapports sexués aux espaces publics dans les quartiers populaires à partir des usages du vélo d’enfants de 9 et 10 ans. Méthodologie : Une équipe de sociologues et de géographes a suivi six classes de CM1 dans trois écoles primaires d’un quartier prioritaire de la Politique de la Ville à Strasbourg. Ces enfants ont bénéficié, pour deux d’entre elles, d’une formation spécifique, d’une part, par des éducateurs sportifs municipaux, et, d’autre part, par des formateurs en sécurité routière. La troisième école fait office de groupe témoin. Des questionnaires ad hoc ont été transmis dans chaque école, avant et après les cycles d’apprentissage du vélo, pour étudier l’évolution de leur niveau technique, de leurs usages du vélo dans le quartier et dans la ville, de leurs relations familiales et amicales nouées autour du vélo. Résultats : Les résultats mettent en avant une différenciation sexuée, nette et persistante, en termes de contrôle du vélo, d’aisance technique dans et hors du quartier et surtout de poids de socialisations distinctes au risque et des contraintes familiales liées à la division par sexe. Conclusion : Dès lors persistent, pour les enfants de ce quartier, des usages singuliers de l’espace public à vélo, liés principalement aux configurations relationnelles sexuées dans les familles populaires. Contribution : Cette étude amène à questionner les méthodes d’apprentissage du vélo pour identifier les précautions à prendre pour favoriser les usages du vélo des garçons et des filles dans l’espace public. Il est alors conseiller de mobiliser les familles pour favoriser le vélo pour tous, particulièrement dans les quartiers socialement défavorisés

Longitudinal Profile Monitor Using Smith-Purcell Radiation: Recent Results from the E-203 Collaboration

TUPC38 - Work supported by seed funding from the John Fell Fund, University of Oxford, Université Paris-Sud, program "Attractivité" and by the ANR under contract ANR-12-JS05-0003-01International audienceWe report on recent measurements made at FACET by the E-203 collaboration to test a longitudinal bunch profile monitor based on Coherent Smith-Purcell radiation. The capacity of this monitor to resolve sub-picosecond bunches will be shown as well as a comparison of profile reconstructed for different beam compression settings. We will also present recent electromagnetic simulations of the interactions between the beam and the grating as well as the expected resolution of such monitor. Comparison between Coherent Smith-Purcell radiation measurement and those made with other techniques will also be discussed. Finally future upgrades of the experiment and steps toward the construction of a single shot longitudinal profile monitor will be presented

Comparative analysis of thermophilic and mesophilic proteins using Protein Energy Networks

<p>Abstract</p> <p>Background</p> <p>Thermophilic proteins sustain themselves and function at higher temperatures. Despite their structural and functional similarities with their mesophilic homologues, they show enhanced stability. Various comparative studies at genomic, protein sequence and structure levels, and experimental works highlight the different factors and dominant interacting forces contributing to this increased stability.</p> <p>Methods</p> <p>In this comparative structure based study, we have used interaction energies between amino acids, to generate structure networks called as Protein Energy Networks (PENs). These PENs are used to compute network, sub-graph, and node specific parameters. These parameters are then compared between the thermophile-mesophile homologues.</p> <p>Results</p> <p>The results show an increased number of clusters and low energy cliques in thermophiles as the main contributing factors for their enhanced stability. Further more, we see an increase in the number of hubs in thermophiles. We also observe no community of electrostatic cliques forming in PENs.</p> <p>Conclusion</p> <p>In this study we were able to take an energy based network approach, to identify the factors responsible for enhanced stability of thermophiles, by comparative analysis. We were able to point out that the sub-graph parameters are the prominent contributing factors. The thermophiles have a better-packed hydrophobic core. We have also discussed how thermophiles, although increasing stability through higher connectivity retains conformational flexibility, from a cliques and communities perspective.</p

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on the substantiation of a health claim related to “non - fermentable ” carbohydrates and maintenance of tooth mineralisation by decreasing tooth demineralisation pursuant to Article 13(5) of Regulation (EC) No 1924/2006

Following an application from Roquette Frères, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of France, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to Nutriose® which should replace “fermentable carbohydrates” in foods or beverages in order to obtain the claimed effect, i.e. maintenance of tooth mineralisation by reducing tooth demineralisation. From the information provided, the Panel noted that the main characteristic of carbohydrates which is relevant to the claimed effect is the rate and amount of acid production resulting from their fermentation by saccharolytic bacteria in the oral cavity. This Opinion applies to “non-fermentable” carbohydrates, which should replace “fermentable” carbohydrates in foods or beverages in order to obtain the claimed effect. The Panel considers that maintaining tooth mineralisation by reducing tooth demineralisation resulting from acid production in plaque caused by the fermentation of carbohydrates is a beneficial physiological effect. The Panel concludes that a cause and effect relationship has been established between the consumption of foods/beverages containing “fermentable” carbohydrates at an exposure frequency of four or more times daily and an increased tooth demineralisation, and that the consumption of foods/beverages containing “non-fermentable” carbohydrates instead of “fermentable” carbohydrates may maintain tooth mineralisation by decreasing tooth demineralisation. In order to bear the claim, “fermentable” carbohydrates should be replaced in foods or beverages by “non-fermentable” carbohydrates, so that consumption of such foods or beverages does not lower plaque pH below 5.7 during and up to 30 minutes after consumption, and does not lead to dental erosion

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013 . S tatement on the safety of ' Cetyl Myristoleate Complex ' as an ingredient in food supplements

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to update its opinion on the safety of ‘Cetyl Myristoleate Complex’ (CMC) as a novel food ingredient in the light of a new repeated dose 90-day oral toxicity study in mice. In its previous opinion of 2010, the Panel concluded that based on the available data, the safety of CMC as an ingredient in food supplements has not been established. This conclusion was based on the considerations that in the absence of appropriate data on absorption, distribution, metabolism and excretion, the provided toxicological data were insufficient. Whereas the applicant considers that the NOAEL of CMC in this new 90-day study was 1000 mg/kg body weight (bw), the highest dose tested, the Panel considers that this study and study report has many shortcomings to be a reliable source of information supporting the absence of adverse effects of the parent material CMC. The Panel concludes that the safety of 'Cetyl Myristoleate Complex' has not been established