597 research outputs found
Launcher attitude control: some additional design and optimization tools
This paper deals with the launcher attitude control during atmospheric flight. A two step approach combining an H1 control design and an optimization procedure is proposed. The first step is multi-objective stationary H1 design based on the Cross Standard Form. It provides easily a first rough solution from a few physical tuning parameters. The second step is a fine tuning using an multi-constraint satisfaction algorithm. This algorithm enables the certification criteria computed on the validation model to be met and is also used to propagate the nominal tuning to the full flight envelope
La formation dâenseignants entre utilitarisme et cycles de Don : illustration en Ă©ducation physique
La formation des enseignants est gĂ©nĂ©ralement conçue en termes de transmission/construction utilitaire de connaissances et de compĂ©tences, et les formateurs valorisent le plus souvent lâadhĂ©sion, au moins formelle, Ă une logique utilitariste. Cependant, certains faits significatifs ne sont pas explicables dans cette logique. Ces faits sont analysĂ©s Ă partir de la thĂ©orie du Don dans des cas dâaide spontanĂ©e et des dispositifs de conseil chez des Ă©tudiants, des enseignants stagiaires et des formateurs. Lâanalyse montre que la nature des liens de confiance ou de dĂ©fiance qui se tissent entre formateurs et formĂ©s pourrait avoir une influence dans la formation des enseignants. Ces liens permettent la rĂ©alisation de cycles de don ou de vengeance qui autorisent ou non le transfert de connaissances chez les enseignants nouveaux venus.In general, teacher training is envisaged in terms of transmission/construction of knowledge and competencies, and trainers most often place value on a utilitarian logic, as least in a formal sense. However, certain significant events are not explained using this logic. These situations are analyzed based on the theory of the âGiftâ in cases of spontaneous help and advice between students, teacher mentors, and teacher trainers. The analysis shows that nature of relationships, being either those of confidence or defiance, that develop between trainers and their students can impact on teacher training. These links show the presence of cycles of gift and of vengeance that facilitate or prevent the transfer of knowledge to newly arrived teachers.La formaciĂłn docente se concibe en general en tĂ©rminos de transmisiĂłn/construcciĂłn utilitaria de conocimientos y de competencias, y los formadores habitualmente valoran la adhesiĂłn, por lo menos formal, a una lĂłgica utilitarista. Sin embargo, algunos hechos significativos no se pueden explicar dentro de esta lĂłgica. Estos hechos son analizados a partir de la teorĂa del Don en unos casos de ayuda espontĂĄnea y de dispositivos de apoyo con estudiantes, docentes en prĂĄcticas y formadores. El anĂĄlisis muestra que la naturaleza de los lazos de confianza o de desconfianza que se generan entre formadores y formados podrĂa influir en la formaciĂłn docente. Estos lazos permiten la realizaciĂłn de ciclos de don o de venganza que autorizan o no la transferencia de conocimientos en los docentes reciĂ©n llegados
Abdominal Computed Tomography Scan: A Useful Diagnosis Tool for Early and Delayed Splenic Complications in Malaria
Resolution enhancement of input parameters in a demand side management model
©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.International audienceDemand side management (DSM) and distributed generation (DG) introduce into power systems new dynamics and behaviors which must be taken into account in the planning and operation of the system. This paper presents a model that aims to simulate the spread out effects of DSM actions in a region. This model is suitable designed to represent the territorial or local specificities of each studied area where the DSM actions apply. The model involves a large number of input data. The main question is what should be the optimal level of detail this data has to be collected in terms of spatial resolution so that meaningful results are obtained. The paper presents a method to define the input data which are critical to collect with a higher spatial resolution. Results for a case study in France are presented
Utilisation des données Google Street View pour cartographier la distribution géographique des espÚces. Une étude préliminaire de la processionnaire du pin (Thaumetopoea pityocampa)
Article publiĂ© suite Ă l'Ă©vĂ©nement : MEDINSECT 3 ; Hammamet-Tunis (Tunisie) - (2012-05-08 - 2012-05-11).Mapping species distribution is an important and useful task to monitor invasive species spread or native species expansion under climate change. Unfortunately it requires a lot of occurrence data that are not easily available from literature and that are very time-consuming to collect in the field. For that reason, we designed a survey with the aim to explore to which extent large-scale databases such as Google Street View could be used to derive valid occurrence data. We worked with an insect species, the Pine Processionary Moth (PPM) Thaumetopoea pityocampa because the larvae of that moth build silk nests on its host tree that are easily visible. The presence of the species at one location can therefore be inferred from visual records derived from the panoramic views available from Google Street View. We designed a standardized procedure allowing the evaluation of the presence of the PPM on a large sampling grid (covering 46 848 km2) located in France. Field sampling has been conducted in parallel, which allowed a straightforward comparison between field and Google-derived datasets. Data derived from Google Street View were highly similar to field data as we found an accuracy (percentage of field values correctly predicted using Google Street View) of 92.9%. We conclude that Google database might provide useful occurrence data for mapping the distribution of species which presence can be visually evaluated such as the PPM. More data are needed, however, to assess the range of spatial scales at which Google Street View actually provides reliable occurrence data.La cartographie de la distribution gĂ©ographique des espĂšces est importante pour suivre lâĂ©volution des aires de distribution dâespĂšces invasives ou dâespĂšces natives en expansion gĂ©ographique. Malheureusement, les donnĂ©es nĂ©cessaires sont parfois difficilement accessibles Ă partir de la littĂ©rature et sont coĂ»teuses Ă collecter sur le terrain. Pour cette raison, nous avons conçu une Ă©tude dans le but d'explorer dans quelle mesure il est possible dâutiliser les bases de donnĂ©es telles que Google Street View (GSV) pour obtenir des donnĂ©es dâoccurrence valides. Nous avons choisi de travailler avec une espĂšce dâinsecte, la chenille processionnaire du pin (PP) Thaumetopoea pityocampa car les larves de cette espĂšce se dĂ©veloppent dans le feuillage des arbres hĂŽtes et tissent un nid blanc aisĂ©ment visible. La prĂ©sence de l'espĂšce dans un site donnĂ© peut donc ĂȘtre facilement renseignĂ©e en examinant les vues panoramiques disponibles pour de nombreuses localitĂ©s dans la base de donnĂ©es de Google Street View. Nous avons conçu une procĂ©dure standardisĂ©e permettant d'Ă©valuer la prĂ©sence de la PP Ă partir des donnĂ©es GSV et nous lâavons mise en oeuvre sur une aire dâĂ©tude couvrant 46 848 km2dans la rĂ©gion Centre en France. La distribution de lâespĂšce a Ă©galement Ă©tĂ© dĂ©crite Ă lâaide dâĂ©chantillonnages rĂ©alisĂ©s sur le terrain. Les donnĂ©es issues de lâexamen des images Google Street View ont Ă©tĂ© comparĂ©es aux donnĂ©es de terrain et se sont rĂ©vĂ©lĂ©es de bons estimateurs de la prĂ©sence de la processionnaire du pin avec une prĂ©cision (proportion de valeurs correctement estimĂ©es) de 92.9% sur notre zone dâĂ©tude pour un maillage de 16 km x 16 km. Ces rĂ©sultats suggĂšrent que lâexploitation des bases de donnĂ©es de GSV pourrait permettre de produire des donnĂ©es Ă©cologiques intĂ©ressantes pour les espĂšces dont la prĂ©sence peut ĂȘtre estimĂ©e visuellement Ă partir de photographies. Des Ă©tudes complĂ©mentaires sont cependant nĂ©cessaires pour mieux cerner la gamme dâĂ©chelles spatiales auxquelles GSV fournit des donnĂ©es dâoccurrence fiables
Prevalence of liver fibrosis and risk factors in a general population using non-invasive biomarkers (FibroTest)
<p>Abstract</p> <p>Background</p> <p>FibroTest and elastography have been validated as biomarkers of liver fibrosis in the most frequent chronic liver diseases and in the fibrosis screening of patients with diabetes. One challenge was to use them for estimating the prevalence of fibrosis, identifying independent risk factors and to propose screening strategies in the general population.</p> <p>Methods</p> <p>We prospectively studied 7,463 consecutive subjects aged 40 years or older. Subjects with presumed advanced fibrosis (FibroTest greater than 0.48) were re-investigated in a tertiary center.</p> <p>Results</p> <p>The sample characteristics were similar to those of the French population. FibroTest was interpretable in 99.6%. The prevalence of presumed fibrosis was 2.8%, (209/7,463), including cirrhosis in 0.3% (25/7,463); 105/209 (50%) subjects with presumed fibrosis accepted re-investigation. Fibrosis was confirmed in 50, still suspected in 27, indeterminate in 25 and not confirmed with false positive FibroTest or false negative elastography in 3 subjects. False negative rate of FibroTest estimated using elastography was 0.4% (3/766). The attributable causes for confirmed fibrosis were both alcoholic and nonalcoholic fatty liver disease (NAFLD) in 66%, NAFLD in 13%, alcohol in 9%, HCV in 6%, and other in 6%. Factors independently associated (all P < 0.003) with confirmed fibrosis were age, male gender, waist circumference, HCV antibody and alcohol consumption estimated using carbohydrate-deficient transferrin, enabling efficient screening-oriented strategies to be compared and proposed.</p> <p>Conclusions</p> <p>Biomarkers have permitted to estimate prevalence of advanced fibrosis around 2.8% in a general population aged 40 years or older, and several risk factors which may be used for the validation of selective or non-selective screening strategies.</p
CoCAS: a ChIP-on-chip analysis suite
Motivation: High-density tiling microarrays are increasingly used in combination with ChIP assays to study transcriptional regulation. To ease the analysis of the large amounts of data generated by this approach, we have developed ChIP-on-chip Analysis Suite (CoCAS), a standalone software suite which implements optimized ChIP-on-chip data normalization, improved peak detection, as well as quality control reports. Our software allows dye swap, replicate correlation and connects easily with genome browsers and other peak detection algorithms. CoCAS can readily be used on the latest generation of Agilent high-density arrays. Also, the implemented peak detection methods are suitable for other datasets, including ChIP-Seq output
Connecting Terminal Carboxylate Groups in Nine-Coordinate Lanthanide Podates: Consequences on the Thermodynamic, Structural, Electronic, and Photophysical Properties
PetaFlow: a global computing-networking-visualisation unitwith social impact
International audienceThe PetaFlow application aims to contribute to the use of high performance computational resources forthe benefit of society. To this goal the emergence of adequate information and communication technologies withrespect to high performance computing-networking-visualisation and their mutual awareness is required. Thedeveloped technology and algorithms are presented and applied to a real global peta-scale data intensive scientificproblem with social and medical importance, i.e. human upper airflow modelling
CD8+ T Cells from Human Neonates Are Biased toward an Innate Immune Response
To better understand why human neonates show a poor response to intracellular pathogens, we compared gene expression and histone modification profiles of neonatal naive CD8+ T cells with that of their adult counterparts. We found that neonatal lymphocytes have a distinct epigenomic landscape associated with a lower expression of genes involved in T cell receptor (TCR) signaling and cytotoxicity and a higher expression of genes involved in the cell cycle and innate immunity. Functional studies corroborated that neonatal CD8+ T cells are less cytotoxic, transcribe antimicrobial peptides, and produce reactive oxygen species. Altogether, our results show that neonatal CD8+ T cells have a specific genetic program biased toward the innate immune response. These findings will contribute to better diagnosis and management of the neonatal immune response.This project was specifically supported by a joint EcosNord-Anuies-SEP-Con-acyt project (M11S01). Work in the M.A.S. laboratory is supported by grantsfrom Consejo Nacional de Ciencia y Tecnologı Ìa(CONACYT; CB-2011-01168182) and Programa de Mejoramiento del Profesorado (PROMEPSI-UAEM/13/342). Work in the S.S. laboratory is supported by recurrent fundingfrom the Inserm and Aix-Marseille University and by specific grants from theEuropean Unionâs FP7 Program (agreement 282510-BLUEPRINT), the Associ-ation pour la Recherche contre le Cancer (ARC) (project SFI20111203756), andthe Aix-Marseille initiative dâexcelence (A*MIDEX) project ANR-11-IDEX-0001-02. We thank Centro Estatal de la Transfusio Ìn Sanguı Ìnea in Cuernavaca for thedonation of leukocyte concentrates and the mothers and babies of HospitalGeneral Parres in Cuernavaca for the donation of cord blood. This study makesuse of data generated by the Blueprint and Roadmap consortia. A full list of theinvestigators who contributed to the generation of the data is availablefromwww.blueprint-epigenome.euandhttp://www.roadmapepigenomics.org/. Funding for the Blueprint project was provided by the European UnionâsSeventh Framework Program (FP7/2007-2013) under grant agreement282510 â BLUEPRINT. The Roadmap consortium is financed by the NIH. Weare grateful to Professor C.I. Pogson for critical reading of the manuscript.S
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