Éditeur(s) : HAL CCSD IOP Publishing
Résumé : The Bureau International des Poids et Mesures (BIPM), Sevres, France, hosted the 7th International Comparison of Absolute Gravimeters (ICAG) and the associated Relative Gravity Campaign (RGC) from August to September 2005.;ICAG 2005 was prepared and performed as a metrological pilot study, which aimed:;(1) To determine the gravity comparison reference values;;(2) To determine the offsets of the absolute gravimeters; and;(3) As a pilot study to accumulate experience for the CIPM Key Comparisons.;This document presents a complete and extensive review of the technical protocol and data processing procedures. The 1st ICAG-RGC comparison was held at the BIPM in 1980-1981 and since then meetings have been organized every 4 years.;In this paper, we present an overview of how the meeting was organized, the conditions of BIPM gravimetric sites, technical specifications, data processing strategy and an analysis of the final results. This 7th ICAG final report supersedes all previously published reports.;Readings were obtained from participating instruments, 19 absolute gravimeters and 15 relative gravimeters. Precise levelling measurements were carried out and all measurements were performed on the BIPM micro-gravity network which was specifically designed for the comparison.
ISSN: 0026-1394

hal-00644529
https://hal.archives-ouvertes.fr/hal-00644529
DOI : 10.1088/0026-1394/48/5/003

Éditeur(s) : Elsevier Science Bv
Résumé : The ontogeny of osmoregulationwas investigated in Litopenaeus stylirostris by studying salinity tolerance and osmoregulatory capacity. Shrimp at different larval and postlarval stages were exposed to various salinities and survival was monitored for 24 h. Survival rates exceeded 80% at salinity over 25 ppt (750 mOsm.kg(-1)) at all the stages. At salinities below to 25 ppt, salinity tolerance was higher in nauplii and zoeae than in mysis larvae. Postlarval stages were able to withstand lower salinities, e.g. 6.0 ppt (176 mOsm.kg(-1)) at PL9 stage, but they were more sensitive than larvae to salinities over 35 ppt (1035 mOsm.kg(-1)). Zoea and mysis larvae slightly hyper-regulated at all tested salinities. After metamorphosis, postlarvae progressively acquired the adult pattern of hyper-hypo-osmoregulation: At PL9, the estimated isosmotic salinity was 24.5 ppt (720 mOsm.kg(-1)); below and over this salinity, animals hyper-regulated and hypo-regulated, respectively. Finally, we determine the effects of lowering salinity at different animal development stages. We conclude that seawater salinity (35 ppt) is optimum during larval stages; but for postlarval stages, lowering salinity at 27 ppt leads to a better growth in 19 days compared to those maintained at 35 ppt (1.07 mg vs 0.47 mg). These results are in agreement with penaeid natural life cycle during which larvae are released in oceanic water while juveniles live in coastal areas where salinity is more fluctuant. (c) 2012 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier Science Bv), 2012-09 , Vol. 362-363 , P. 10-17

Droits : 2012 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00107/21843/20058.pdf
DOI:10.1016/j.aquaculture.2012.07.026
http://archimer.ifremer.fr/doc/00107/21843/

Éditeur(s) : Styli 2003. Trente ans de crevetticulture en Nouvelle-Calédonie. Nouméa - Koné, 2-6 juin 2003. 2004. Gorarant C, Harache Y, Herbland A, Mugnier C. Ed. Ifremer, Actes de Colloque, n°38, pp.113-120
Résumé : Two oyster species are currently present along the French coasts : the indigenous European flat oyster (Ostrea edulis), and the Pacific cupped oyster (Crassostrea gigas), that has been introduced from Japan since the beginning of the 70ies. The flat oyster successively suffered from two protozoan diseases during the 60ies and its production decreased from 20 000 tons/year by that time to 1 500 tons/year nowadays. Consequently, the oyster production is principally (99%) based upon the Pacific oyster species with approximately 150 000 tons/year among which 90% are grown from the natural spat. However, the hatchery production of this species is developing and was estimated to 400 to 800 millions spat in 2002. Moreover, strengthened relationships between IFREMER and the 5 commercial hatcheries, that all joined the SYSAAF (Union of the French poultry, shellfish and fish farming selectors), allow to plan for new genetic breeding programs. At the end of the 80ies, IFREMER initiated a genetic breeding program for the resistance of the European flat oyster to the bonamiosis, and obtained strains more tolerant to this disease. After two generations of massal selection, molecular markers had identified a reduced genetic basis in this program. It was then reoriented to an intra-familial selection. However, we were confronted to a zootechnic problem to manage such a scheme and we compromised by an intra-cohorts of families selection scheme managed using molecular markers. The program has now reached the transfer level with experimentation at a professional scale. Concerning the Pacific cupped oyster, and in parallel with the obtaining and the study of polyploids, performance of different Asian cupped oyster strains were compared to the one introduced in France thirty years ago and currently suffering from summer mortalities. The local strain exhibited better performance, certainly based upon a good local adaptation. In other respects, although early growth is a relevant criteria for selection for growth to commercial stage, it is not to be privileged in the context of an oyster producing region with a limited food availability. Contrary, the spat summer mortality became a priority for numerous teams (genetic, physiology, pathology, ecology,...) joined in the MOREST program. The first results showed important survival differences between fullsib and halsib families. They indicate a genetic determinism to this character "survival" and promote for its selection.
Deux espèces d'huîtres sont aujourd'hui présentes sur les côtes françaises : l'huître plate européenne (Ostrea edulis), indigène, et l'huître creuse du Pacifique (Crassostrea gigas), introduite du Japon dans le début des années 1970. L'huître plate a subi coup sur coup, dans les années 1960, deux maladies dues à des protozoaires parasites et sa production est ainsi passée de 20 000 t/an dans les années 1960 à 1500 t/an aujourd'hui en France. Il en résulte que la filière ostréicole française repose quasiment exclusivement (99%) sur la production de l'huître creuse, C. gigas, avec 150 000 tonnes en 2000 dont environ 90% est issu du captage naturel. Cependant, la reproduction de cette espèce en écloserie est actuellement en expansion avec une estimation de 400 à 800 millions de naissains commercialisés en 2002. Des rapports renforcés entre l'IFREMER et les cinq écloseries françaises de la filière ostréicole, qui adhèrent toutes au SYSAAF (SYndicat des Sélectionneurs Avicoles et Aquacoles Français), permettent désormais d'envisager le développement de nouveaux programmes d'amélioration génétique. A la fin des années 1980, un programme de sélection pour la résistance de l'huître plate à la bonamiose a été initié au sein de l'IFREMER, et a permis d'obtenir des souches plus tolérantes à cette maladie. Après deux générations en sélection massale, les marqueurs moléculaires avaient mis en évidence une base génétique réduite au sein de ce programme qui s'était alors orienté vers une sélection intra-familiale. Devant la lourdeur zootechnique d'un tel schéma, un compromis a été trouvé en réalisant une sélection au sein de cohortes de familles biparentales, la gestion de ces cohortes étant permise par les analyses moléculaires. Le programme est maintenant dans sa phase de transfert, avec des expérimentations à plus grande échelle en partenariat avec la profession. En ce qui concerne l'huître creuse, et en parallèle de l'obtention et l'étude de polyploïdes, les performances de différentes souches d'huîtres creuses provenant d'Asie ont été comparées à celles de la souche introduite en France il y a trente ans, sujette à des mortalités estivales. La souche locale présente de meilleures performances, vraisemblablement grâce à une adaptation bien réalisée. Par ailleurs, bien que l'amélioration de la croissance jusqu'à la taille commerciale s'avère possible par une sélection précoce au stade larvaire, le critère de croissance n'est pas nécessairement à privilégier dans le contexte d'un bassin ostréicole disposant de ressources trophiques limitées. En revanche, les importantes mortalités rencontrées par le naissain en périodes estivales constituent le sujet d'étude prioritaire sur lequel se sont penchées de nombreuses équipes (génétique, physiologie, pathologie, écologie, ...) dans le cadre du grand défi MOREST. Les premiers résultats ont mis en évidence de fortes différences de survie entre des familles biparentales d'animaux indiquant un déterminisme génétique du caractère « survie », et encourageant dans la voie d'une sélection pour ce caractère.

Droits : 2004 Ifremer
http://archimer.ifremer.fr/doc/2003/acte-3491.pdf
http://archimer.ifremer.fr/doc/00000/3491/

Éditeur(s) : HAL CCSD
Résumé : The bacterial microbiota of ants (Hymenoptera: Formicidae) is known to have a defensive role in social insects, particularly for leaf-cutting ants (Formicidae: Attini) due to the use of antimicrobial molecules produced by cuticular actinobacteria. In this thesis, we studied the bacterial microbiota of ants in French Guyana using different approaches based on natural products chemistry and molecular ecology. The first chapter describes the isolation, identification, culture and biological evaluations of 43 cuticular actinobacteria. Antagonism bioassays of isolated strains and antibiotic activities of the culture extracts against human pathogens are presented as well as the identification of an antimicrobial cyclic dipeptide (Cyclo (LPro-LPhe)) isolated from a strain close to Streptomyces thioluteus. Moreover, the implementation of molecular networks applied to UPLC/MS/MS analysis of actinobacterial cocultures allowed us to explore the diversity of metabolites produced under these conditions. The second chapter presents a methodological study to evaluate the capacity of four DNA extraction methods, in terms of richness and composition of the cuticular bacterial microbiota, in high-throughput sequencing from Atta cephalotes and Pseudomyrmex penetrator. The results of metabarcoding highlight two methods of extraction and reveal inter- and intraspecific differences in the composition of cuticular bacterial communities. Finally, chapter three describes the composition of the cuticular bacterial microbiota of Camponotus femoratus and Crematogaster levior in ant garden and the results reveal the acquisition in the environment of a part of the microbiota. In parallel, metabolomic analyses of ant’s cuticle show, on the contrary, a greater specificity related to the ant species. Future researches focusing on statistical analysis strategies combining metabarcoding and metabolomics data are discussed.
Le microbiote bactérien cuticulaire des fourmis (Hymenoptera : Formicidae) est connu pour avoir un rôle défensif chez ces insectes sociaux, notamment chez les fourmis attines (Formicidae : Attini) grâce l’utilisation de molécules antimicrobiennes produites par des actinobactéries cuticulaires. Dans le cadre de cette thèse, nous avons étudié le microbiote bactérien des fourmis de Guyane en utilisant différentes approches en chimie des produits naturels et en écologie moléculaire. Le premier chapitre décrit l’isolement, l’identification, la culture et l’évaluation biologique de 43 actinobactéries cuticulaires de fourmis de Guyane. Les tests d’antagonismes des souches isolées et l’activité antibiotique des extraits de culture contre des micro-organismes pathogènes humains sont présentés ainsi que l’identification d’un dipeptide cyclique (Cyclo(LPro-LPhe)) antimicrobien qui a été isolé à partir d’une souche proche de Streptomyces thioluteus. Par ailleurs, la mise en œuvre de réseaux moléculaires appliqués à une analyse par UPLC/MS/MS de cocultures d’actinobactéries a permis d’explorer la diversité des métabolites produits dans ces conditions. Le deuxième chapitre présente une étude méthodologique pour comparer quatre méthodes d’extraction d’ADN, en termes de richesse et de composition du microbiote bactérien cuticulaire, par séquençage haut débit à partir des espèces Atta cephalotes et Pseudomyrmex penetrator. Les résultats du métabarcoding ADN mettent en lumière deux méthodes d’extraction et révèlent des différences inter- et intraspécifiques dans la composition des communautés bactériennes cuticulaires. Enfin, le chapitre trois décrit la composition du microbiote bactérien cuticulaire des espèces Camponotus femoratus et Crematogaster levior dans les jardins de fourmis. Les résultats soulignent l’acquisition d’une partie du microbiote dans l’environnement. En parallèle l’analyse métabolomique des cuticules montre à contrario une plus grande spécificité liée à l’espèce de fourmi. Les recherches futures axées sur les stratégies d’analyses statistiques combinant le métabarcoding et la métabolomique sont discutées.
https://tel.archives-ouvertes.fr/tel-01537793

NNT : 2017YANE0003
tel-01537793
https://tel.archives-ouvertes.fr/tel-01537793
https://tel.archives-ouvertes.fr/tel-01537793/document
https://tel.archives-ouvertes.fr/tel-01537793/file/thesecarolinebirer.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
An inter-laboratory exercise was organized under the PHARMAS EU project, by the Advanced School of Public Health (EHESP), in order to evaluate the performances of analytical methods for the measurement of antibiotics in waters (surface and tap). This is the first time such an exercise on antibiotics has been organized in Europe, using different kinds of analytical methods and devices. In this exercise thirteen laboratories from five countries (Canada, France, Italy, the Netherlands and Portugal) participated, and a total number of 78 samples were distributed. During the exercise, 2 testing samples (3 bottles of each) prepared from tap water and river water, respectively, spiked with antibiotics, were sent to participants and analyzed over a period of one month. A final number of 77 (98.7%) testing samples were considered. Depending on substances studied by each participant, 305 values in duplicate were collected, with the results for each sample being expressed as the target concentration. A statistical study was initiated using 611 results. The mean value, standard deviation, coefficient of variation, standard uncertainty of the mean, median, the minimum and maximum values of each series as well as the 95% confidence interval were obtained from each participant laboratory. In this exercise, 36 results (6% of accounted values) were outliers according to the distribution over the median (box plot). The outlier results were excluded. In order to establish the stability of testing samples in the course of the exercise, differences between variances obtained for every type of sample at different intervals were evaluated. The results showed no representative variations and it can be considered that all samples were stable during the exercise. The goals of this inter-laboratory study were to assess results variability when analysis is conducted by different laboratories, to evaluate the influence of different matrix samples, and to determine the rate at which participating laboratories successfully completed the tests initiated.
Talanta

hal-00878118
https://hal.archives-ouvertes.fr/hal-00878118
DOI : 10.1016/j.talanta.2012.06.064
PUBMED : 22939142

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Thermal diffusivity of synthetic quartz single-crystals and natural polycrystalline aggregates were measured using a modified Angstrom method at ambient pressure and up to 800 degrees C in order to investigate the effect of crystal preferred orientation on thermal diffusivity of quartz rich rocks. The thermal diffusivity tensor of quartz was determined by measuring the thermal diffusivity of an oriented synthetic quartz single-crystal along the [100] and [001] directions. A naturally deformed, fine-grained quartzite mylonite, was used to compare the single crystal properties with aggregate properties. Using the crystal preferred orientations (CPO) measured by the Electron Back Scattered Diffraction (EBSD) method and the measured thermal diffusivity tensor of quartz, the three-dimensional aggregate thermal diffusivity was modelled using volume averaging models. In order to test the validity of these models that are only based on the properties of the constituent minerals, the thermal diffusivity was then measured on oriented cores as a function of temperature, along three orthogonal directions, parallel to the (X-lineation, Y, Z-pole to foliation) structural frame. Both modelled and direct measurement of thermal diffusivity show an anisotropy of thermal diffusivity, heat transport being more effective parallel to Y-direction and less effective parallel to the lineation X-direction. Thermal diffusivities measured in a given direction on the natural rock are lower by less than 10% than the modelled thermal diffusivity in the same direction, showing that rock imperfections have a weak effect on heat transport. In addition, the modelled thermal diffusivity anisotropy based on the characterization of crystal orientations and thermal diffusivity tensor shows a good agreement with measurements in both alpha and beta stability field. This validation of the petrophysical simulation allows for evaluating the 3D thermal diffusivity of quartz rich rocks in different crustal conditions. The 3D thermal diffusivity of five naturally deformed quartzites displaying quartz fabrics expected in different crustal pressure and temperature ranges were simulated. The resulting thermal diffusivity anisotropies of quartzites range between 40% and 10%, depending on temperature, crystallographic fabric patterns and fabric strength. Under crustal conditions, quartzites deformed in the granulite facies display a high thermal diffusivity in the (XZ) foliation plane, whereas quartzites deformed in greenschist facies have highest thermal diffusivity in the (Z) direction normal to the foliation plane.
ISSN: 0040-1951

hal-00413568
https://hal.archives-ouvertes.fr/hal-00413568
DOI : 10.1016/j.tecto.2008.11.006

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Inorganic arsenic is a toxic environmental contaminant to which humans are mainly exposed through drinking water. This metalloid impairs functions of several key immune cells. Particularly, it reduces IL-2 secretion and proliferation of blood peripheral mononuclear cells stimulated by lectins that, however, do not mimic physiological T cell activation. The present study used isolated human T cells activated, in a more physiological manner, through stimulation with CD3/CD28 antibodies, to carefully analyze the impact of arsenic on T cell proliferation and cytokine expression. We demonstrate that non cytotoxic concentrations of sodium arsenite (As(III), 0.25-2μM) significantly reduce T cell proliferation by increasing the percentage of non dividing cells blocked in G1 phase and by preventing cyclin D3 and CDC25A expression. They also markedly, although not totally, reduces IL-2 expression at both mRNA and protein levels; however, metalloid-dependent inhibition of T cells could not be reversed by addition of recombinant IL-2. In addition, As(III) markedly reduces secretion of interferon-γ without impairing that of IL-4 and IL-13; it also decreases interferon-γ mRNA levels but increases those of IL-13. Finally, simultaneously to its immune effects, As(III) rapidly and potently increases expression of the redox-sensitive genes HMOX1, NQO1 and GCLM in activated T cells without altering the levels of reactive oxygen species. In conclusion, our results demonstrate that As(III) inhibits T cell proliferation, independently of IL-2, and alters the Th balance of cytokines secreted by co-stimulated T cells which thus constitute direct targets of this major environmental contaminant.
ISSN: 0300-483X

inserm-00872848
http://www.hal.inserm.fr/inserm-00872848
DOI : 10.1016/j.tox.2012.05.025
PUBMED : 22683347

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : This chapter seeks to contribute to a greater understanding of tourism on small tropical islands and to tourism planning in this context by outlining aspects of the methodology used in the preparation of the Samoa Tourism Development Plan 2002-2006 and by discussing some of the issues that arose from this process. In particular, the chapter presents a ‘question-asking’ approach that involves wide-ranging stakeholder consultation to identify and then address key issues, namely: - How much tourism does Samoa want and at what rate should it be developed over the next five years? - What will the growth of tourism in Samoa over the period 2002-2006 depend on? - What forms of tourism should be developed and where? - What are the most appropriate processes of tourism development for Samoa? The strategies formulated in the plan are then outlined. The paper concludes that local participation, while invaluable, is by itself insufficient for the preparation of an effective tourism development plan.
En présentant la méthodologie utilisée dans la présentation du Plan d’Aménagement Touristique de Samoa 2002-2006, ce chapitre cherche à éclaircir certains aspects de l’aménagement touristique dans les petites îles tropicales, ainsi que ceux de la planification touristique en ces lieux. Plus spécifiquement, cette étude présente une approche basée sur la formulation de questions destinées aux diverses parties intéressées afin d’identifier et puis d’adresser les points-clés de l’aménagement touristique dans le pays. Quatre questions principales résultent de ce processus, à savoir : Combien de tourisme veut le pays et à quel rythme doit-il se développer pendant les cinq années à venir ? De quels facteurs dépend la croissance du tourisme pendant la période 2002-2006 ? Quelles formes de tourisme faut-il développer et à quels endroits ? Quels sont les processus d’aménagement touristique les plus appropriés pour Samoa? On présente ensuite les stratégies formulées dans le plan. Pour conclure, il semble que la participation locale, bien qu’inappréciable, soit insuffisante par elle-même pour préparer un plan d’aménagement touristique efficace.
Este capítulo presenta la metodología utilizada en la preparación del Plan de Desarrollo Turístico de Samoa 2002-2006 y traza sus líneas generales. De esta manera, el plan pone de manifiesto los puntos claves del desarrollo turístico en las pequeñas islas tropicales y los aspectos metodológicos de la planificación turística en ese contexto. En particular, el trabajo presenta un enfoque basado en la formulación de preguntas destinadas a distintos participes con el fin de identificar los puntos claves del desarrollo turístico del país y de formular algunas estrategias en función de ellos. Cuatro preguntas principales resultan de este proceso:- Cómo quiere Samoa dimensionar su turismo? A qué ritmo debe desarrollarse durante los cinco próximos años? - De qué dependerá el mencionado desarrollo durante el periodo 2002-2006? - Qué tipologías de turismo deben desarrollarse y dónde? - Cuáles son los procesos de desarrollo más apropiados para Samoa? Posteriormente presentamos las estrategias del plan. Concluimos que la participación local es imprescindible pero, sola, no permite la preparación de un plan de desarrollo turístico eficaz.
Samoa

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.1393
http://journals.openedition.org/etudescaribeennes/1393

Éditeur(s) : HAL CCSD Elsevier
Résumé : Le titre a été changé Ancien titre: Roles for local crowding and pressure in counteracting density fluctuations at equilibrium
International audience
What is the probability that all the gas in a box accumulates in the same half of this box? Though amusing, this question underlies the fundamental problem of density fluctuations at equilibrium, which has profound implementations in many physical fields. The currently accepted solutions are derived from the studies of Brownian motion by Smoluchowski, but they are not appropriate for the directly colliding particles of gases. Two alternative theories are proposed here using self-regulatory Bernoulli distributions. A discretization of space is first introduced to develop a mechanism of matter congestion holding for high densities. In a second mechanism valid in ordinary conditions, the influence of local pressure on the location of every particle is examined using classical laws of ideal gases. This approach reveals that a negative feedback results from the reciprocal influences between individual particles and the population of particles, which strongly reduces the probability of atypical microstates. Finally, a thermodynamic quantum of time is defined to compare the recurrence times of improbable macrostates predicted through these different approaches.
Physica A: Statistical Mechanics and its Applications

hal-00920985
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00920985
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00920985v2/document
ARXIV : 1404.6223
DOI : 10.1016/j.physa.2014.03.067

Éditeur(s) : HAL CCSD
Résumé : Inorganic arsenic is an environmental human carcinogen, but is also studied these days because of its potential effectiveness in curing chronic inflammatory disease. Indeed, this metalloid possesses immunosuppressive properties which can dysregulate physiological mechanisms involved in immune defense, or reduce inflammation associated with those inflammatory diseases. Inorganic arsenic is known mainly to alter functions of T cells and macrophages. However, it is unknown whether arsenic targets dendritic cells (DCs). Yet, this antigen presenting cells plays a major role in the immunosurveillance, and is involved in the physiopathology of chronic inflammatory diseases. So, the aim of my thesis work was to study the effects of inorganic arsenic on in vitro differenciation and maturation of dendritic cells from human monocytes. Our results mainly shows that concentrations corresponding to those measured in environmentally exposed people, inhibits DCs secretion of proinflammatory cytokines, which plays a major role in activation and polarization of T cells. Particularly, arsenic strongly impairs expression and secretion of interleukine 12 (IL-12) by an underlying molecular mechanism involving Nrf2. Finally, this work shows that inorganic arsenic has immunosuppressive properties on the physiology in vitro of human dendritic cells. Immunotoxicity may then contribute to the metalloid toxicity in environmentally exposed people. This element could be taken into account when determining arsenic effects in curing some chronic inflammatory diseases.
L’arsenic inorganique est un contaminant environnemental, cancérogène pour l’homme, mais également un métalloïde étudié, aujourd’hui, dans le traitement de maladies inflammatoires chroniques. Il possède des propriétés immunosuppressives pouvant déréguler les mécanismes physiologiques de défense ou bloquer l’exacerbation de réponses inflammatoires chroniques. L’arsenic inorganique altère principalement les fonctions des lymphocytes T et des macrophages. En revanche, l’impact du métalloïde sur la physiologie des cellules dendritiques (DCs) est peu connu. Pourtant, ces cellules présentatrices d’antigène jouent un rôle fondamental dans les processus d’immunosurveillance et sont très impliquées dans la physiopathologie des maladies inflammatoires chroniques. Dans ce contexte, les objectifs de mon travail de thèse étaient d’étudier les effets de l’arsenic inorganique sur la différenciation et la maturation in vitro de DCs générées à partir de monocytes humains. Nos résultats démontrent principalement que des concentrations de métalloïde, compatibles avec les taux plasmatiques d’arsenic mesurés chez les individus exposés, répriment la capacité des DCs à sécréter différentes cytokines pro-inflammatoires jouant un rôle essentiel dans l’activation et la polarisation des lymphocytes T. En particulier, l’arsenic inhibe l’expression et la sécrétion de l’interleukine-12 par un mécanisme moléculaire impliquant le facteur de transcription Nrf2. Au total, ces travaux de thèse démontrent que l’arsenic inorganique possède des propriétés immunosuppressives sur la physiologie in vitro des DCs humaines. Cette immunotoxicité pourrait contribuer à la toxicité du métalloïde chez l’homme exposé par voie environnementale, et être prise en compte pour déterminer les effets de l’arsenic dans le traitement de certaines maladies inflammatoires chroniques
https://tel.archives-ouvertes.fr/tel-01135887

NNT : 2013REN1B013
tel-01135887
https://tel.archives-ouvertes.fr/tel-01135887
https://tel.archives-ouvertes.fr/tel-01135887/document
https://tel.archives-ouvertes.fr/tel-01135887/file/pdf2star-1392896105-Th--se-M--linda-Macoch2.pdf

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : International audience
Chlordecone is an organochlorine pesticide that was extensively used in the French West Indies to fight weevils in banana plantations from 1973 to 1993. This has led to a persistent pollution of the environment and to the contamination of the local population for several decades with effects demonstrated on human health. Chlordecone accumulates mainly in the liver where it is known to potentiate the action of hepatotoxic agents. However, there is currently no information on its in situ localization in the liver. We have thus evaluated a matrix-assisted laser desorption ionization (MALDI) imaging quantification method based on labeled normalization for the in situ localization and quantification of chlordecone. After validating the linearity and the reproducibility of this method, quantitative MALDI imaging was used to study the accumulation of chlordecone in the mouse liver. Our results revealed that normalized intensities measured by MALDI imaging could be first converted in quantitative units. These quantities appeared to be different from absolute quantities of chlordecone determined by gas chromatography (GC), but they were perfectly correlated (R(2) = 0.995). The equation of the corresponding correlation curve was thus efficiently used to convert quantities measured by MALDI imaging into absolute quantities. Our method combining labeled normalization and calibration with an orthogonal technique allowed the in situ absolute quantification of chlordecone by MALDI imaging. Finally, our results obtained on the pathological mouse liver illustrate the advantages of quantitative MALDI imaging which preserves information on in situ localization without radioactive labeling and with a simple sample preparation.
ISSN: 0003-2700

hal-01118103
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118103
PUBMED : 24837422
DOI : 10.1021/ac500313s

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé : International audience
This paper presents a synthetic view of the geodynamic evolution of the Zagros orogen within the frame of the Arabia-Eurasia collision. The Zagros orogen and the Iranian plateau preserve a record of the long-standing convergence history between Eurasia and Arabia across the Neo-Tethys, from subduction/obduction processes to present-day collision (from ~ 150 to 0 Ma). We herein combine the results obtained on several geodynamic issues, namely the location of the oceanic suture zone, the age of oceanic closure and collision, the magmatic and geochemical evolution of the Eurasian upper plate during convergence (as testified by the successive Sanandaj-Sirjan, Kermanshah and Urumieh-Dokhtar magmatic arcs), the P-T-t history of the few Zagros blueschists, the convergence characteristics across the Neo-Tethys (kinematic velocities, tomographic constraints, subduction zones and obduction processes), together with a survey of recent results gathered by others. We provide lithospheric-scale reconstructions of the Zagros orogen from ~ 150 to 0 Ma across two SW-NE transects. The evolution of the Zagros orogen is also compared to those of the nearby Turkish and Himalayan orogens. In our geotectonic scenario for the Zagros convergence, we outline three main periods/regimes: (1) the Mid to Late Cretaceous (115-85 Ma) corresponds to a distinctive period of perturbation of subduction processes and interplate mechanical coupling marked by blueschist exhumation and upper-plate fragmentation, (2) the Paleocene-Eocene (60-40 Ma) witnesses slab break-off, major shifts in arc magmatism and distributed extension within the upper plate, and (3) from the Oligocene onwards (~ 30-0 Ma), collision develops with a progressive SW migration of deformation and topographic build-up (Sanandaj-Sirjan Zone: 20-15 Ma, High Zagros: ~12-8 Ma; Simply Folded Belt: 5-0 Ma) and with partial slab tear at depths (~10 Ma to present). Our reconstructions underline the key role played by subduction throughout the whole convergence history. We finally stress that such a long-lasting subduction system with changing boundary conditions also makes the Zagros orogen an ideal natural laboratory for subduction processes.
ISSN: 0016-7568

insu-00616582
https://hal-insu.archives-ouvertes.fr/insu-00616582
https://hal-insu.archives-ouvertes.fr/insu-00616582/document
https://hal-insu.archives-ouvertes.fr/insu-00616582/file/692.full.pdf
DOI : 10.1017/S001675681100046X

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We compile field data collected along the eastern part of the North Pyrenean Zone (NPZ) to point to a tectonic evolution under peculiar thermal conditions applying to the basin sediments in relation with the opening of the Cretaceous Pyrenean rift. Based on this compilation, we show that when thinning of the continental crust increased , isotherms moved closer to the surface with the result that the brittle-ductile transition propagated upward and reached sediments deposited at the early stage of the basin opening. During the continental breakup, the pre-rift Mesozoic cover was efficiently decoupled from the Paleozoic basement along the Triassic evaporite level and underwent drastic ductile thinning and boudinage. We suggest that the upper Albian and upper Creta-ceous flysches acted as a blanket allowing temperature increase in the mobile pre-rift cover. Finally, we show that continuous spreading of the basin floor triggered the exhumation of the metamorphic, ductily sheared pre-rift cover, thus contributing to the progressive thinning of the sedimentary pile. In a second step, we investigate the detailed geological records of such a hot regime evolution along a reference-section of the eastern NPZ. We propose a balanced restoration from the Mouthoumet basement massif (north) to the Boucheville Albian basin (south). This section shows a north to south increase in the HT Pyrenean imprint from almost no metamorphic recrystallization to more than 600 °C in the pre-and syn-rift sediments. From this reconstruction, we propose a scenario of tectonic thinning involving the exhumation of the pre-rift cover by the activation of various detachment surfaces at different levels in the sedimentary pile. In a third step, examination of the architecture of current distal passive margin domains provides confident comparison between the Pyrenean case and modern analogs. Finally, we propose a general evolutionary model for the pre-rift sequence of the Northeastern Pyrenean rifted margin.
ISSN: 0040-1951

Droits : http://creativecommons.org/licenses/by-nc-nd/
insu-01355131
https://hal-insu.archives-ouvertes.fr/insu-01355131
https://hal-insu.archives-ouvertes.fr/insu-01355131/document
https://hal-insu.archives-ouvertes.fr/insu-01355131/file/TECTO10807-Incorporated%20changes-rev2.pdf
DOI : 10.1016/j.tecto.2016.07.022

Éditeur(s) : Elsevier
Résumé : We present results from multibeam bathymetric data acquired during 2005 and 2006, in the region of maximum slip of the 26 Dec. 2004 earthquake (Mw 9.2). These data provide high-resolution images of seafloor morphology of the entire NW Sumatra forearc from the Sunda trench to the submarine volcanic arc just north of Sumatra. A slope gradient analysis of the combined dataset accurately highlights those portions of the seafloor shaped by active tectonic, depositional and/or erosional processes. The greatest slope gradients are located in the frontal 30 km of the forearc, at the toe of the accretionary wedge. This suggests that long-term deformation rates are highest here and that probably only minor amounts of slip are accommodated by other thrust faults further landward. Obvious N-S oriented lineaments observed on the incoming oceanic plate are aligned sub-parallel to the fracture zones associated with the Wharton fossil spreading center. Active strike-slip motion is suggested by recent deformation with up to 20-30 m of vertical offset. The intersection of these N-S elongated bathymetric scarps with the accretionary wedge partly controls the geometry of thrust anticlines and the location of erosional features (e.g. slide scars, canyons) at the wedge toe. Our interpretation suggests that these N-S lineaments have a significant impact on the oceanic plate, the toe of the wedge and further landward in the wedge. Finally, the bathymetric data indicate that folding at the front of the accretionary wedge occurs primarily along landward-vergent (seaward-dipping) thrusts, all unusual style in accretionary wedges worldwide. The N-S elongated lineaments locally act as boundaries between zones with predominant seaward versus landward vergence.
Earth and Planetary Science Letters (0012-821X) (Elsevier), 2008-11 , Vol. 275 , N. 3-4 , P. 201-210

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-5166.pdf
DOI:10.1016/j.epsl.2008.04.053
http://archimer.ifremer.fr/doc/00000/5166/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cet article analyse les déterminants de la disposition des managers à formaliser les PME informelles en Côte d’Ivoire. Les données utilisées portent sur 400 entreprises du secteur informel enquêtées dans le cadre du projet CAPEC/CRDI. À partir des statistiques descriptives et de l’estimation d’un modèle Probit, l’étude met en évidence d’une part les variables qui influencent négativement et d’autre part celles qui influencent positivement la disposition à formaliser les PME. Il ressort de ces enquêtes que les taxes, le fait que l’entreprise soit dirigée par une femme, les coûts d’enregistrement, l’affiliation à une organisation politique et l’ignorance des procédures ont un effet négatif sur la disposition des managers à formaliser leurs entreprises. Les résultats montrent que la possession d’un plan d’affaires à la création, l’expérience du manager, la localisation, le niveau d’instruction supérieur, la simplification des procédures d’enregistrement affectent positivement la propension à formaliser les PME informelles. De même, les problèmes d’accès au financement et aux marchés publics conduisent les managers à la formalisation de leurs entreprises. Au regard de ces déterminants, la réduction des coûts de la formalisation, un meilleur accès des PME qui se formalisent au financement et aux marchés publics, le renforcement des capacités des opérateurs de l’informel, l’instauration d’une fiscalité incitative et la vulgarisation des procédures de déclaration s’avèrent des leviers importants de la formalisation.
This paper analyzes the determinants of the willingness of managers to formalize informal SMEs in Côte d'Ivoire. The data used relate to 400 informal sector enterprises surveyed under the CAPEC / IDRC project. On the basis of descriptive statistics and the estimation of a Probit model, the study highlights both variables that negatively influence and those that positively influence the willingness to formalize SMEs. These surveys show that taxes, the fact that the company is headed by a woman, registration costs, affiliation to a political organization and ignorance of procedures have a negative effect on the formalization of businesses.Moreover, the results show that ownership of a business plan at creation, managerial experience, location, higher education, simplification of registration procedures positively affect the propensity to formalize informal SMEs. Similarly, the problems of access to finance and public procurement lead to more formalization. In view of these determinants, the reduction in the costs of formalization, better access by SMEs to financing and public procurement, capacity building for informal operators, the introduction of tax incentives and the Dissemination procedures are important levers of formalization.
Côte d’Ivoire

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.10358
http://journals.openedition.org/etudescaribeennes/10358

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Objective. — The aim of this study was to validate the French translation of the category-rating-10 used for assessing perceived exertion (RPE) when monitoring training loads. Methods. — Fifty athletes from individual (Taekwondo) and team sports (soccer) volunteered. Two forward translations, a reconciled version, and then a back-translation were completed to validate the final French version. French Session-RPE, heart rate, and duration were recorded for 622 training sessions.Results. —The comparability of language and similarity of interpretability using a Likert scale were 2 and 1, respectively. A high Cronbach’s coefficient ( = 0.77) was found. The intraclass correlation coefficient of session-RPE was 0.77. High correlations were determined between the session-RPE and HR-based methods during training sessions. The effect size was 0.97.Conclusion. — When monitoring training load, the French version of category-rating-10 exhibits similar reliability, validity, and sensitivity to change as the English version.
Objectif. — L’objet de cette étude était de valider la traduction franc¸aise de l’échelle de la Note de Catégorie-10 utilisée dans l’évaluation de la perception de l’effort pour contrôler la charge d’entraînement.Méthode. —Cinquante athlètes de sport individuel (taekwondo) et d’équipe (football) ont volontairement participé à l’étude. Deux traductions en mode direct, une version réconciliée, puis une traduction indirecte ont été effectuées pour évaluer la version franc¸aise finale. Lafréquence cardiaque, la durée et la charge d’entraînement quantifiée par la version franc¸aise ont été enregistrées durant 622 séances d’entraînement.Résultats. — La comparaison et la similarité de l’interprétation en utilisant l’échelle de Likert étaient de 2 et 1, respectivement. Un coefficient élevé de -Cronbach a été calculé ( = 0,77). Le coefficient de corrélation intraclasse de la RPE-de-séance était de 0,77. Des corrélations élevées ont été observées entre la RPE-séance et les différentes méthodes de contrôle de la charge d’entraînement basées sur la FC (les méthodes de Banister et d’Edwards). L’effet de taille de l’échantillon était de 0,97.Conclusion. —Dans le cadre du contrôle de la charge d’entraînement, la version franc¸aise de l’échelle de la Note de Catégorie-10 présente une similarité de fiabilité, validé et sensibilité aux changements avec la version anglaise.
ISSN: 0765-1597

hal-01163458
https://hal.univ-antilles.fr/hal-01163458
DOI : 10.1016/j.scispo.2012.07.008

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Mantle noble gases record important and ancient isotopic heterogeneities, which fundamentally influence our understanding of mantle geodynamics, yet these heterogeneities are difficult to fully interpret without understanding the basic mechanisms of noble gas storage and transport in mantle minerals. A series of annealing experiments that mimic mantle conditions (i.e. sub-solidus with natural, polycrystalline, texturally equilibrated olivines at low noble gas partial pressures) show that intergranular interfaces (grain boundaries) are major hosts for noble gases in the mantle, and that interfaces can dramatically fractionate noble gases from their radio-parents (U + Th and K). Therefore, noble gas isotopic heterogeneities in the mantle could result from grain size variations. Fine-grained lithologies (mylonites and ultramylonites, for example) with more grain boundaries will have lower U/3He ratios (compared to a coarse grained equivalent), which, over time, will preserve higher 3He/4He ratios. As predicted by theory of points defect diffusivity, these results show that noble gas diffusion along interfaces is different from those in the grain lattice itself at low temperatures. However, for grain size relevant of the Earth's mantle, the resulting effective correlated activation energies (Ea)(Ea) and pre-exponential factors (Do/a2)(Do/a2) produce similar diffusivities at mantle temperatures for interface- and lattice-hosted helium. Therefore, grain boundaries do not significantly affect helium transport at mantle conditions and length scales.
ISSN: 0012-821X

hal-01236013
https://hal.archives-ouvertes.fr/hal-01236013
DOI : 10.1016/j.epsl.2015.08.024

Éditeur(s) : Agrocampus Ouest
Résumé : The origin of fish stocks variability is a key question in fisheries science. The exploitation indeed has an important effect in terms of biomass reduction, but environmental forcing is of central interest as it affects numerous key biological processes. Recent theoretical results have shown that the nature of the environmental fluctuations, the environmental noise, has important ecological consequences on populations and particularly on their fluctuations. In addition the effects of exploitation, that are not a simple removal of individuals but also profoundly modifies the demography, the structure and the trophic interactions of fish stocks, can interact with environmental effects. Through an extensive analysis of time series we aim at understanding the effects of environmental noise on fish stocks variability, according to their biological characteristics (life-history traits) and their exploitation. A technique of time series comparison allows to propose that the fluctuations of Atlantic large pelagics are inherited from the interaction between environmental effects, endogenous dynamics and exploitation. We then show that the colour of environmental noise affects the variability of time series, its effects depending on the life-history traits of species. Finally, preliminary results on bentho-demersal and pelagic stocks from the North Atlantic suggest that the exploitation increases the sensitivity of fish stocks to the colour of environmental noise and affects their variability, according to their life-history traits.
L'origine de la variabilité des stocks de pêche est une question centrale en halieutique. Si l'exploitation tient un rôle important dans la réduction de biomasse, le forçage environnemental affecte de nombreux processus biologiques clés. Des résultats théoriques récents ont montré que la nature des fluctuations environnementales, la couleur du bruit environnemental, avait des implications écologiques importantes sur les populations et notamment sur leurs fluctuations. De plus, les effets environnementaux peuvent agir en interaction avec l'exploitation qui ne consiste pas en un simple prélèvement d'individus, mais qui modifie profondément la démographie, la structure et les interactions trophiques des stocks. Au travers de l'analyse extensive de séries temporelles, on essaye ici de comprendre les effets de la couleur du bruit environnemental sur la variabilité des stocks en fonction de leurs caractéristiques biologiques (traits d'histoire de vie) et de leur état d'exploitation. Le développement d'une technique de comparaison des séries temporelles permet de proposer que les fluctuations des grands pélagiques de l'Atlantique sont héritées de l'interaction entre effets environnementaux, dynamique interne et dynamique de l'exploitation. On montre ensuite que la couleur du bruit environnemental affecte la variabilité des séries temporelles, mais que son effet dépend des traits d'histoire de vie des espèces. Enfin, des résultats préliminaires sur les stocks bentho-démersaux et pélagiques de l'Atlantique Nord, suggèrent que l'exploitation augmente la sensibilité des stocks à la couleur du bruit environnemental et affecte leur variabilité en fonction de leurs traits d'histoire de vie.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2008/these-6596.pdf
http://archimer.ifremer.fr/doc/00000/6596/

Éditeur(s) : HAL CCSD
Résumé : International audience
Astrocytes send out long processes that are terminated by endfeet at the vascular surface and regulate vascular functions as well as homeostasis at the vascular interface. To date, the astroglial mechanisms underlying these functions have been poorly addressed. Here we demonstrate that a subset of messenger RNAs is distributed in astrocyte endfeet. We identified, among this transcriptome, a pool of messenger RNAs bound to ribosomes, the endfeetome, that primarily encodes for secreted and membrane proteins. We detected nascent protein synthesis in astrocyte endfeet. Finally, we determined the presence of smooth and rough endoplasmic reticulum and the Golgi apparatus in astrocyte perivascular processes and endfeet, suggesting for local maturation of membrane and secreted proteins. These results demonstrate for the first time that protein synthesis occurs in astrocyte perivascular distal processes that may sustain their structural and functional polarization at the vascular interface.
Cell Discovery

hal-01545319
https://hal.archives-ouvertes.fr/hal-01545319
DOI : 10.1038/celldisc.2017.5

Éditeur(s) : HAL CCSD BMJ Publishing Group
Résumé : International audience
BACKGROUND: Chronic HCV infection is associated with the development of hepatic fibrosis. The direct role of HCV in the fibrogenic process is unknown. Specifically, whether HCV is able to infect hepatic stellate cells (HSCs) is debated. OBJECTIVE: To assess whether human HSCs are susceptible to HCV infection. DESIGN: We combined a set of original HCV models, including the infectious genotype 2a JFH1 model (HCVcc), retroviral pseudoparticles expressing the folded HCV genotype 1b envelope glycoproteins (HCVpp) and a subgenomic genotype 1b HCV replicon, and two relevant cellular models, primary human HSCs from different patients and the LX-2 cell line, to assess whether HCV can infect/replicate in HSCs. RESULTS: In contrast with the hepatocyte cell line Huh-7, neither infectious HCVcc nor HCVpp infected primary human HSCs or LX-2 cells. The cellular expression of host cellular factors required for HCV entry was high in Huh-7 cells but low in HSCs and LX-2 cells, with the exception of CD81. Finally, replication of a genotype 2a full-length RNA genome and a genotype 1b subgenomic replicon was impaired in primary human HSCs and LX-2 cells, which expressed low levels of cellular factors known to play a key role in the HCV life-cycle, suggesting that human HSCs are not permissive for HCV replication. CONCLUSIONS: Human HSCs are refractory to HCV infection. Both HCV entry and replication are deficient in these cells, regardless of the HCV genotype and origin of the cells. Thus, HCV infection of HSCs does not play a role in liver fibrosis. These results do not rule out a direct role of HCV infection of hepatocytes in the fibrogenic process.
ISSN: 0017-5749

hal-01063909
https://hal.archives-ouvertes.fr/hal-01063909
DOI : 10.1136/gutjnl-2013-305634
PUBMED : 25063678