Éditeur(s) : HAL CCSD EDP Sciences
Résumé : International audience
Understanding mechanisms in DSSCs is fundamental for their improvement; this includes the nanocrystalline semiconducting layer behaviour. Different mesoporous TiO2 layers are fabricated and analyzed for possible use in DSSC solar cells. The preparations included the addition of P123 triblock copolymer as structuring agent to the synthesized anatase sol. This preparation was also mixed with Degussa P25 TiO2 nanoparticles in one case and polystyrene latex in another. Mesoporous mixed TiO2-SiO2 thin layers were also analyzed. The diverse morphologies and features are studied by microscopic techniques and by means of spectral quantum efficiency of a photoelectrochemical cell (PEC) that uses as photoelectrode the unsensitized porous TiO2 layer. Contact angle measurements are also performed. We have found that a very high specific area due to very small nanocrystals and small pores can hinder electrolyte penetration in the pores formed by TiO2 nanograins, affecting photoelectrodes efficiency. © EDP Sciences, 2015.
ISSN: 1286-0042

hal-01683213
https://hal.univ-antilles.fr/hal-01683213
DOI : 10.1051/epjap/2015150221

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In France, reducing social health inequalities has become an explicit goal of health policies over the past few years, one of its objectives is specifically the reduction of the perinatal mortality rate. This study investigates the association between infant mortality and social deprivation categories at a small area level in the Lille metropolitan area, in the north of France, to identify census blocks where public authorities should prioritize appropriate preventive actions. We used census data to establish a neighbourhood deprivation index whose multiple dimensions encompass socioeconomic characteristics. Infant mortality data were obtained from the Lille metropolitan area municipalities to estimate a death rate at the census tract level. We used Bayesian hierarchical models in order to reduce the extra variability when computing relative risks (RR) and to assess the associations between infant mortality and deprivation. Between 2000 and 2009, 668 cases of infant death occurred in the Lille metropolitan area (4.2 per 1,000 live births). The socioeconomic status is associated with infant mortality, with a clear gradient of risk from the most privileged census blocks to the most deprived ones (RR = 2.62, 95 % confidence interval [1.87; 3.70]). The latter have 24.6 % of families who were single parents and 29.9 % of unemployed people in the labor force versus 8.5 % and 7.7 % in the former. Our study reveals socio-spatial disparities in infant mortality in the Lille metropolitan area and highlights the census blocks most affected by the inequalities. Fine spatial analysis may help inform the design of preventive policies tailored to the characteristics of the local communities.
ISSN: 1092-7875

hal-00876255
https://hal.archives-ouvertes.fr/hal-00876255
DOI : 10.1007/s10995-013-1251-8
PUBMED : 23479336

Éditeur(s) : HAL CCSD
Résumé : International audience
Environmental context The safeguarding of water supplies and drinking water is a major issue when considering human health risk management. In this context, an automatic and on-site fractionation system for the detection of organic contaminants has been developed. The main goal of this system is to establish an initial diagnosis by identifying a class of substances involved in a case of pollution. Abstract This paper proposes a new approach for the preconcentration, fractionation, prediction and detection of organic micropollutants in water. The main aim of this study was to implement an innovative fractionation method and a prediction model based on the physicochemical properties of compounds and interactions with the sorbent of solid-phase extraction cartridges. Two sorbents (Strata-SAX and Oasis-HLB) and three specific eluting solvents (mixture of methanol and sodium chloride and mixtures of acetonitrile and ultrapure water) were used to separate organic compounds into five specific fractions according to their physicochemical properties (anionic and cationic or neutral compounds with various polarity). More than 75 molecules (43 molecules individually studied and a mixture with 43 molecules, including 11 molecules individually studied) including pesticides, pharmaceuticals, endocrine disruptors and polycyclic aromatic hydrocarbons, with various properties were studied, and the results showed that the elution fraction can be predicted for more than 85% of the compounds. This methodology could simplify the analytical chain by reducing detailed analysis on limited categories of compounds, and could be used for a rapid and on-site screening of organic compounds. © CSIRO 2016.
Environmental Chemistry

hal-01373945
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01373945
DOI : 10.1071/EN15135

Éditeur(s) : HAL CCSD EDP Sciences
Résumé : International audience
In order to ensure a sustainable management of reef fisheries, data need to be collected regularly on the effect of these fisheries on both fish resources and the ecosystems that sustain them. Habitat and resources monitoring programs can provide such information, but are difficult to implement as they involve a range of technical, financial and human resources. Regarding these problems, the involvement of the local population in monitoring programs, called participatory monitoring, seems to offer solutions. Indeed, participatory monitoring has the potential of increasing the number of data collected at low cost, while taking advantage of the traditional ecological knowledge available locally. Some questions need clarifying, however: which methods can bring relevant information for the monitoring of reef fisheries while being appropriate to the motivations and skills of the local population? Is the degree of participation of the local population sufficient to make the monitoring program work, particularly over the long term? To answer these questions, participatory monitoring methods commonly used for coral reef ecosystems have been implemented to assess reef fisheries at three different sites: Moorea island and Tikehau atoll in French Polynesia, and the Bay of Tulear in Madagascar. While highlighting the relevance of some participatory monitoring programs for snapshot and large-scale surveys, the results of this study also show their lesser interest for regular data gathering on long-time scales. In any case, strong coordination and supervision by scientists are considered essential.
La gestion durable des écosystèmes coralliens nécessite de disposer d’informations régulières concernant l’impact des pêcheries sur les ressources récifales et sur les écosystèmes dont elles dépendent. Les suivis intégrés des ressources, des habitats et des espèces associées qui visent à fournir ce type d’informations sont difficiles à mettre en œuvre, car ils impliquent de nombreuses ressources humaines, techniques et financières. Face à ces problèmes, la participation de la société civile dans les programmes de suivi semble en mesure d’apporter des solutions. Dans le but de tester cette hypothèse, des méthodes de suivi participatif ont été mises en œuvre afin de caractériser des pêcheries récifales sur trois socio-écosystèmes contrastés : l’île de Moorea et l’atoll de Tikehau en Polynésie française, et le littoral de Tuléar à Madagascar. Les résultats de cette étude soulignent la pertinence de certains suivis participatifs pour fournir une vision écosystémique dans le cas de collecte de données ponctuelles et de large envergure, et leur intérêt moindre pour la collecte continue de données sur de longues échelles de temps. Dans tous les cas, une structure de coordination et l’implication de scientifiques s’avèrent primordiales pour assurer pérennité et fiabilité au système de suivi.
ISSN: 1240-1307

hal-01302983
https://hal-univ-perp.archives-ouvertes.fr/hal-01302983
DOI : 10.1051/nss/2013109

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The minerals constituting the Earth's upper mantle are nominally anhydrous silicates (NAMs). However they do contain hydrogen as a trace element, decorating point defects in their crystalline structure. Experimental petrology and mineralogy have quantified the maximum concentration under several compositional and thermodynamic conditions, but systematic studies on the hydrogen concentration in minerals from mantle-derived rocks have only recently been carried out. Here, we have compiled the distribution of hydrogen in upper mantle peridotite xenoliths, from which several conclusions can be drawn. NAMs from peridotite xenoliths contain a few ppm wt. H2O in their structure. From the current database, the hydrogen concentrations in olivine regularly increase with increasing depth. The amount of hydrogen in NAMs from peridotite xenoliths from subduction contexts is not higher than in other geological context for similar temperature and pressure conditions. The highest hydrogen concentrations is found in peridotitic olivines from cratonic mantle, and are likely due to the depth of origin. The increasing hydrogen concentration in olivine with increasing depth is likely controlled by the increase of H partitioning into olivine at the expense of orthopyroxene as imposed by a decrease in Al content in opx with depth. However, the sparse data could also indicate that the bulk hydrogen concentration slightly increases with depth > 150 km. In this case, it would suggest, locally (Udachnaya for example), a possible increase in water fugacity due to fluid saturation. Even if the most abundant mineral in mantle rocks is olivine, the bulk hydrogen concentration in peridotites is controlled by the amount of hydrogen stored in pyroxenes. However, hydrogen concentration in olivine remains crucial for consequences on physical properties such as rheology and electrical conductivity. Kinetics of hydrogen transport is reviewed and hydrous melt/fluid percolation appears necessary to homogenize the hydrogen distribution at km-scale. Sampling of natural rock specimens is currently biased (e.g., in favor of optically attractive samples) and needs improvement, which will be achieved by increasing sample diversity (all type of grain sizes, lithologies, geological settings) and size of rock samples, as well as advances in analytical techniques. Acquisition of high quality data will be achieved by studying the co-existing minerals in mantle specimens, exploring each sample by linear and mapping measurements, and using appropriate FTIR calibrations for polarized and unpolarized radiation.
ISSN: 0024-4937

hal-01306676
https://hal.archives-ouvertes.fr/hal-01306676
DOI : 10.1016/j.lithos.2015.11.012

Éditeur(s) : HAL CCSD
Résumé : Red blood cell hemodynamics influence blood rheology and thus circulatory function. Different authors showed that red blood cells are heterogeneous in blood flow. This heterogeneity could be explained by physical characteristics such as morphology, aggregability and deformability, but also by cellular and molecular environment. All these notions are found in sickle cell disease where sickle red blood cells become more rigid, leading to vascular occlusions, increased with an inflammatory context. In a preceding study, our results showed that velocity heterogeneity allow RBC classification, leading to different RBC sub-groups, using a dynamical approach and flow studies. In order to have a better understanding of the physiological meaning of such an heterogeneity, dynamical velocity experiences have been conducted in the case of normal and sickle red blood cells with different endothelial activations by proinflammatory cytokines, under a constant venular flow. Thus, normal and sickle red blood cells are classified into different sub-groups, showing their heterogeneity. Moreover, sub-population velocities and distribution evolve differently according to vascular state or treatment. These results show that red blood cell velocities and rheology depend on vascular environment and red blood cell morphology. However, the physiological meaning of this behavior should be explained by cellular and molecular effects of such activation.
https://hal.archives-ouvertes.fr/hal-00201461

hal-00201461
https://hal.archives-ouvertes.fr/hal-00201461
https://hal.archives-ouvertes.fr/hal-00201461/document
https://hal.archives-ouvertes.fr/hal-00201461/file/RBCV_Marianne_v1.pdf

Éditeur(s) : HAL CCSD
Résumé : Meteorological phenomena with scales lower than hurricanes, from extreme rainfalls to pollution peaks, represent important environmental and health risks in the Caribbean. These examples show the need to downscale large-scale meteorological data to island-scale fields.The main goal of the present numerical study is the analysis of the meso- and micro-scale mechanisms inducing diurnal and nocturnal circulations in the Guadeloupe archipelago. The Weather Research and Forecasting model is employed. The micro-scale results are obtained by the coupling of the 1-km simulated fields and the Large Eddy Simulation method. Then, in order to analyze the dispersion of a pollutants plume, the micro-scale outputs with 111 m of resolution are used to force the lagrangian particles dispersion model FLEXPART. The study has been conducted for three real cases of weather types linked with strong, medium and weak trade winds.The results of simulations, validated with available observed data, permitted to simulate all local circulations, including a nocturnal counter-current flow which may induce a pollution peak in the urban area of Pointe-à-Pitre city.These works, which may be applied to other Lesser Antilles islands, suggest many environmental and energy applications.
Les phénomènes météorologiques d'échelles inférieures aux cyclones, depuis les pluies intenses, jusqu'à la dégradation de la qualité de l'air, ont pour les Caraïbes une importance aiguë en termes de risques naturels ou de risques sur la santé. Ces exemples attestent de la nécessité d'utiliser des méthodes de descentes d'échelle pour exploiter l'information météorologique de grande échelle et dériver des scénarios locaux appliqués aux territoires insulaires. Les travaux présentés ont pour principaux objectifs la simulation numérique et l'analyse des mécanismes méso- et micro-échelles qui induisent des circulations locales diurnes et nocturnes sur l'archipel de la Guadeloupe, à l'aide du modèle numérique météorologique Weather Research and Forecasting. Les résultats des simulations micro-échelles sont obtenus par le couplage des champs modélisés à 1 km avec la méthode Large Eddy Simulation. Les sorties micro-échelles, à 111 m, sont ensuite utilisées pour forcer le modèle lagrangien de dispersion de particules FLEXPART afin d'étudier la dispersion d'un panache de polluants. L'étude a été menée pour trois cas réels de situations météorologiques correspondant à des alizés soutenus, moyens et faibles. Les résultats des simulations, après validation, et comparaison aux données d'observation disponibles, permettent de restituer l'ensemble des circulations locales et soulignent l'existence d'un écoulement nocturne à contre courant susceptible d'induire une forte pollution sur la zone urbaine de Pointe-à-Pitre. Cette étude, transposable aux autres îles des petites Antilles, laisse envisager de nombreuses applications environnementales et énergétiques.
https://hal.archives-ouvertes.fr/tel-01074600

Droits : info:eu-repo/semantics/OpenAccess
tel-01074600
https://hal.archives-ouvertes.fr/tel-01074600
https://hal.archives-ouvertes.fr/tel-01074600/document
https://hal.archives-ouvertes.fr/tel-01074600/file/rcece_thesis.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : In the context of an ongoing monitoring study on the impacts of gold-mining activities on critical ecosystem processes, we explored the use of soil Denitrifying Enzyme Activity (DEA) and Substrate Induced Respiration (SIR) as ecosystem indicators in tropical rainforests of French Guiana. We also propose DEA/SIR ratio as ecosystem attribute able to describe the state of an ecosystem and to reflect changes in ecological processes. With this purpose, we measured SIR, DEA and DEA/SIR ratio in five gold-mining areas and five surrounding natural reference rainforests. We also measured indicators in two conditions of spontaneous regeneration of vegetation (stratified or not) and two conditions of soil rehabilitation (prior preparation of soils or not). We showed a high variability of DEA, SIR and DEA/SIR ratio in the natural reference forests. This pointed out the necessity to identify relevant reference systems - i.e. proving a close match in all relevant ecological dimensions - to compare with closed perturbed systems in order to assess the levels of alterations after disturbances. Results showed a high impact of gold mine on microbial processes with a strong decrease of DEA (10-fold lower), SIR (2-fold lower) and DEA/SIR ratio (8-fold lower) in perturbed areas in comparison with natural reference forests. The type of spontaneous vegetation (stratified or not) influenced the values of indicators as well as prior rehabilitation of soils, demonstrating the capacity of DEA. SIR and DEA/SIR ratio to respond in proportion to the perturbation (robustness) and to the different levels of restoration (sensitivity). The systematic decrease of the ratio DEA/SIR observed in the studied perturbed situations demonstrates clearly that the structure of microbial communities has been also modified. The ratio DEA/SIR proved to be robust and sensitive, and able to describe in fairly fine way changes of soil microbial communities in terms of structure and function in gold mine areas and during processes of restoration. We propose to use DEA, SIR and DEA/SIR ratio as bioindicators of both structural and functional aspects of C and N cycling in soils. Together with others bioindicators based on key supporting functions in soils, these indicators should accurately evaluate the ecological potential of natural ecosystems and the levels of degradation in case of land-use changes. (C) 2012 Elsevier Ltd. All rights reserved.
ISSN: 1470-160X

hal-01190730
https://hal.archives-ouvertes.fr/hal-01190730
DOI : 10.1016/j.ecolind.2012.01.021
PRODINRA : 213639

Éditeur(s) : Gauthier-villars
Résumé : Until recently, the study of the pathology of oysters concerned some bacterial and a large number of parsitic diseases. Among the latter, diseases caused by fungi such as Labyrinthomyxa marina or by sporozoa such as Minchinia nelsoni in the American oyster have had very important econimic repercussions in the affected areas. The causes of some severe epizooties, such as the "Malpecue Bay disease" in Canada, have never been determined; in other cases, including the mass mortality of the Portuguese oyster in Fance, several years of investigations have been required before the first results of an etiologic nature were obtained. The use of electron microscopy has permitted great strides in the pathology of oysters. Thus, virus diseases have been found to be associated with the diseases of the Portuguse oyster, with gill disease and with the mass mortality of 1970. New and important data have also been obtained with regard to the structure and development of Marteilia refringens a parasite of the flat oyster which has been recognized as belonging to the haplosporidan species. Recently, Mycoplasma-like and Rickettsia-like organisms have been detected in several oyster species and oyster viruses have been isolated on cell cultures. Such results confirm the evolution of research in this field.
Les résultats acquis en matière de pathologie des huîtres concernaient jusqu'à une date récente quelques maladies bactériennes et surtout de nombreuses parasitoses. Pour certaines épizooties graves, comme la maladie de l'huître américaine de Malpèque au Canada, les causes n'ont jamais été déterminées et pour d'autres, comme la mortalité massive de l'huître portugaise en France, les premiers résultats d'ordre étiologique n'ont été obtenus que tardivement avec la mise en évidence d'une infection virale. L'étude ultra-structurale de Marteilia refringens, parasite de l'huître plate, la mise en évidence d'une virose associées à la maladie des branchies de l'huître portugaise, puis la découverte récente de nouveaux germes pathogènes tels que mycoplasmes et rickettsies et l'isolement de virus sur cultures cellulaires chez plusieurs espèces d'huîtres devaient confirmer l'évolution des recherches dans ce domaine.
Oceanologica Acta (0399-1784) (Gauthier-villars), 1978 , Vol. 1 , N. 2 , P. 255-262

Droits : 1978 Elsevier
http://archimer.ifremer.fr/doc/00015/12631/9520.pdf
http://archimer.ifremer.fr/doc/00015/12631/

Éditeur(s) : HAL CCSD EDP Sciences
Résumé : International audience
The dynamic model of plant growth GreenLab describes plant architecture and functional growth at the level of individual organs. Structural development is controlled by formal grammars and empirical equations compute the amount of biomass produced by the plant, and its partitioning among the growing organs, such as leaves, stems and fruits. The number of organs initiated at each time step depends on the trophic state of the plant, which is evaluated by the ratio of biomass available in plant to the demand of all the organs. The control of the plant organogenesis by this variable induces oscillations in the simulated plant behaviour. The mathematical framework of the GreenLab model allows to compute the conditions for the generation of oscillations and the value of the period according to the set of parameters. Two case-studies are presented, corresponding to emergence of oscillations associated to fructification and branching. Similar alternating patterns are commonly reported by botanists. In this article, two examples were selected: alternate patterns of fruits in cucumber plants and alternate appearances of branches in Cecropia trees. The model was calibrated from experimental data collected on these plants. It shows that a simple feedback hypothesis of trophic control on plant structure allows the emergence of cyclic patterns corresponding to the observed ones.
ISSN: 0973-5348

hal-00780592
https://hal-ecp.archives-ouvertes.fr/hal-00780592
https://hal-ecp.archives-ouvertes.fr/hal-00780592/document
https://hal-ecp.archives-ouvertes.fr/hal-00780592/file/Mathieu_2012_Published_mmnp201276p47.pdf
DOI : 10.1051/mmnp/20127603

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
We mainly study a system of two coupled nonlinear Schrödinger equations where one equation includes gain and the other one includes losses. This model constitutes a generalization of the model of pulse propagation in bire-fringent optical fibers. We answered partially to a question of some authors in [8], that in the Manakov case, the solution stays in L 2 (0, T ; H 1), that means that the solution can not blow up in finite time. More precisely, the bound that is provided in this paper does not seem to be optimal but different than those that has been given from a previous study [8]. Thanks to the way we treat the a priori estimate, we obtain a sharp bound in L 2 (0, T ; H 1), which would be difficult to reach from the study of other authors [8]. The result is illustrated by numerical results which have been obtained with a finite element solver well adapted for that purpose.
ISSN: 0022-2526

Droits : http://creativecommons.org/licenses/by/
hal-01270459
https://hal.archives-ouvertes.fr/hal-01270459
https://hal.archives-ouvertes.fr/hal-01270459/document
https://hal.archives-ouvertes.fr/hal-01270459/file/paperver2.pdf

Éditeur(s) : HAL CCSD John Libbey Eurotext
Résumé : International audience
French toxicological reference values (VTR) and French occupational exposure limit values (VLEP) are indicators that are widely used in risk assessment for, respectively, human and occupational health. Neither value can replace the other. However, the information obtained for one can be very useful for the other. We propose to clarify the fundamental differences and similarities between these two values. To achieve this, we review first their history and then the methods used to derive them; we conclude by proposing some improvements to harmonize them. A case study of formaldehyde illustrates our analysis.
ISSN: 1635-0421

hal-00936267
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00936267
DOI : 10.1684/ers.2013.0647

Éditeur(s) : HAL CCSD Springer International Publishing
Résumé : International audience
Understanding the formation processes of maritime archaeological sites and the maritime landscape in the French West Indies is a new challenge in underwater archaeology. This chapter presents an analysis of formation and conservation processes of maritime archaeological sites in Guadeloupe using evidence from both historical and archaeological research. Formation parameters include contemporary events associated with maritime loss and the in situ geophysical regime. Questions considered include: what natural and/or anthropogenic parameters best classify maritime sites in the context of the French West Indies landscape? And: how do these parameters vary by site location? Field-tested case studies are used to assess the archaeological potential for submerged shipwreck sites for three locational typologies within the landscape: submerged, coastal, and micro-island. Geomorphic parameters, including erosion, sea level evolution, and tectonic activity, are evaluated with regard to the formation of coastal Amerindian and colonial sites. The location of shipwrecks are primarily determined by historic patterns in commercial trade and by topographical constraints associated with accessibility, risk, and the presence of natural harbors, parameters important in the Caribbean. A unique feature of Guadeloupe is the high variability of the structure of the coastline through time. The recent discovery of numerous underwater prehistoric artifacts confirms that several islands, coastal areas, and their archaeological sites have been completely submerged or eroded since their formation. The characterization of these formation processes provides both academically interesting and practical information valuable in assessing the impact of development and urbanization in Guadeloupe’s maritime landscape.
Formation Processes of Maritime Archaeological Landscapes

hal-01448703
https://hal.archives-ouvertes.fr/hal-01448703

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We experimentally studied the predatory behavior of Polybia rejecta (Vespidae, Polistinae, Epiponini) towards 2-88 mm-long insects attracted to a UV light trap. Foragers, which began to hunt at 6:30, selected 4-14 mm-long prey insects. Prey detection by sight by hovering wasps was confirmed using decoys. After the wasps landed and walked along a sinuous path, prey were detected by contact or from a distance (1-3cm). This was followed by seizure, stinging (contrarily to most other known cases), prey manipulation and retrieval. Prey that flew off might be caught in flight. The prey load, representing 30.7% of a forager's weight, was optimized by capturing up to six small prey or two medium-sized prey successively (both of which might be consumed in situ). The foragers cut off the wings of larger prey or cut them into two pieces and returned to gather the second piece. The handling time increased exponentially with the weight of the prey. Partial loading (i.e., retrieving a load much inferior to the maximum possible) was likely related to social facilitation, a form of nest-based recruitment that was demonstrated through the experimental elimination of local enhancement by removing foragers (both mechanisms favor the exploitation of favorable patches).
ISSN: 0376-6357

hal-01533217
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01533217
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01533217/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01533217/file/Dejean%20et%20al.%20-%20The%20predatory%20behavior%20of%20the%20Neotropical%20social%20w.pdf
DOI : 10.1016/j.beproc.2017.05.011

Résumé : Ce travail est l'expression d'une volonté de chercheurs, de la Carabe d'améliorer les connaissances scientifiques méso- et micro-météorologiques appliquées aux milieux insulaires sous influence des alizés et de développer la recherche dans ces domaines.On sait que le phénomène météorologique le plus remarquable impactant les îles de la Caraïbe reste le cyclone tropical. Mais d'autres phénomènes, a des échelles inferieures, telles que les pluies intenses, les houles, la dégradation de la qualité de l'air ont une importance aigüe en termes de risques naturels ou de risques sur la sante. Ces exemples attestent la nécessité d'utiliser des méthodes de descente d'échelle pour exploiter l'information météorologique et/ou climatique de grande échelle et dériver des scenarios locaux et régionaux appliques aux territoires insulaires. Ce défi est important car l'attente d'analyses scientifiques pertinentes dans ces domaines est grande.Les travaux présentés dans ce mémoire ont pour principaux objectifs la simulation numérique puis l'analyse des mécanismes méso- et micro-échelles qui induisent des circulations locales diurnes et nocturnes sur l'archipel de la Guadeloupe à l'aide de codes numériques météorologiques éprouves car largement utilises en recherche et en prévision opérationnelle.Ils constituent donc la première étude de modélisation numérique à haute résolution en basse atmosphère, par descente d'échelle dynamique, pour des intervalles d'espace compris entre 1 km et 111 m sur cet archipel.Le modelé atmosphérique Weather Research and Forecasting ARW V3.4 (WRF ARW), non-hydrostatique, a été utilise pour l'ensemble des simulations pour modéliser la troposphère depuis l'échelle globale à l'échelle de la turbulence.Trois situations météorologiques classiques réelles d'une durée de 48 heures, correspondant à 80 % des situations météorologiques observées dans la zone, alizes soutenus (AS), alizes moyens (AM), alizes faibles (AF) ont été examinées. Ces situations sont caractérisées par les valeurs du nombre de Froude local suivantes : 0,82 (AS), 0,41 (AM) et 0,21 (AF). Six domaines de modélisation ont été sélectionnés pour effectuer les descentes d'échelle dynamiques : D01 (maille de 27 km), D02 (maille de 9 km), D03 (maille de 3 km), D04 (maille de 1 km), D05 (maille de 333 m) et D06 (maille de 111 m) avec soixante-dix niveaux verticaux. Les quatre premiers domaines (D01 à D04) couvrent l'archipel de la Guadeloupe et sont utilisés en mode méso-échelle à l'aide d'un schéma d'ensemble de couche limite planétaire YSU. Les domaines D05 (couvrant l'île de la Basse-Terre et le centre de l'archipel) et D06 (couvrant la zone littorale et rurale du Petit Cul-de-Sac Marin et la zone urbaine de l'agglomération pointoise) sont utilisés en mode Large Eddy Simulation avec une fermeture de la turbulence 1,5 TKE 3D. Le modèle WRF a été forcé toutes les six heures par l'assimilation des champs d'analyses globales du modèle NCEP FNL (1° de résolution). Les simulations effectuées ont permis d'obtenir des champs de variables météorologiques 10-minutes à très hautes résolutions spatiales.Les résultats des simulations méso- et micro-échelles ont été confrontés aux valeurs expérimentales obtenues à l'aide de capteurs places sur des mâts météorologiques (campagne Atmo-Mangrov et réseau de mesure Météo-France). Il s'agissait d'optimiser l'utilisation des couplages de codes numériques tout en conservant la possibilité de les confronter aux observations expérimentales.Les résultats des simulations numériques micro-échelles, des différents cas (AS, AM, AF) sont utilisées pour forcer (c'est-à-dire définir les conditions limites) un modèle lagrangien de dispersion de particules : FLEXPART. Le système couple FLEXPART-WRF a été employé dans le domaine D06 pour étudier la dispersion du panache d'oxydes d'azote émis par la principale usine de production d'électricité de l'île.
The present work expresses the will of Caribbean researchers to improve the meso- and micro-meteorological scientific knowledge of the trade winds influenced island areas, and to develop research in these domains.It is well known that tropical hurricanes remain the most remarkable meteorological phenomena that affect the Caribbean islands. But some other phenomena, of smaller scale, such as intense rainfall events, swells, or air quality degradation, are of extreme importance for natural or health hazards. These examples show the need to use downscaling methods to exploit large scale meteorological or climatic information, and to obtain local and regional scenarios for the island areas. This is an important challenge, as sound scientific studies in these matters are eagerly expected. The aim of the research works exposed in the present dissertation is numerical simulation and analysis of the meso- and microscale mechanisms that induce diurnal and nocturnal local circulations in the Guadeloupe archipelago, using numerical meteorological models that are widely used in research and in operational forecasting.These works represent the first high-resolution (1 km to 111 m) numerical study of the lower atmosphere over the Guadeloupe archipelago. The Weather Research and Forecasting ARW 3.4 (WRF-ARW) model is used to simulate the troposphere from global scale to turbulence scale. Real cases of three typical weather types (80% of cases during a year) are examined during 48 hours : strong trade winds (STW), medium trade winds (MTW) and weak trade winds (WTW). These weather types are characterized by values of the local Froude number : 0.82 (STW), 0.41 (MTW) and 0.21 (WTW). Six domains have been selected for the dynamical downscaling : D01 (grid spacing of 27 km), D02 (grid spacing of 9 km), D03 (grid spacing of 3 km), D04 (grid spacing of 1 km), D05 (grid spacing of 333 m) and D06 (grid spacing of 111 m), including 70 vertical levels. The first four domains (D01 to D04) cover the Guadeloupe archipelago and are used in the meso-scale simulations with the planetary boundary layer scheme YSU (ensemble mean). Domain D05 (covering the Basse-Terre island and the middle of the archipelago) and domain D06 (covering the coastal and rural area of Le Petit Cul-de-Sac Marin and the urban area of Pointe-à-Pitre), are employed in the micro-scale simulation (LES) with the 3D TKE 1.5 order closure scheme. WRF has been 6 hourly reinitialized with the NCEP FNL global analyses (resolution of 1°). These simulations permitted to obtain 10-minutes meteorological variable fields with a very high resolution (111 m).Meso-scale and micro-scale model results have been evaluated with observational data from meteorological stations (field campaign Atmo-Mangrov, French Met Office).Once validated, the micro-scale model outputs have been used for the assimilation of the lagrangian particle dispersion model : FLEXPART. The coupling FLEXPART-WRF has been employed in domain D06, in order to analyze the dispersion of the nitrogen oxide plume emitted by the main power plant of the archipelago.

http://www.theses.fr/2014AGUY0735/document

Éditeur(s) : HAL CCSD
Résumé : International audience
In this paper, we introduce and consider a new class of variational inequalities involving two operators, which is called the general nonconvex quasi variational inequality. Several special cases are discussed. We use the projection technique to establish the equivalence between the general noncon vex quasi variational inequalities and the xed point problems. This alternative equivalent formulation is used to study the existence of a solution of the general nonconvex quasi variational inequalities. Using these equivalent for-mulations, we suggest and analyze a wide class of new extragradient methods for solving the general nonconvex quasi variational inequalities. Convergence criteria of these new iterative methods is considered under some suitable conditions.
Bulletin of Mathematical Analysis and Applications

hal-00783908
https://hal.univ-antilles.fr/hal-00783908

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : L’article présente comment les enjeux et les relations socioéconomiques qui sous-tendent la construction des discours sur le développement touristique influencent les pratiques matérielles dans le processus d’appropriation des territoires. Il soutient que les jeux de pouvoir, les valeurs et les croyances constituent un ensemble de relations fabriquant les discours des différents groupes et classes dans un territoire touristique. Ces discours modèlent, à travers des pratiques matérielles, l’espace touristique. Il démontre que l’enchevêtrement de ces relations complexe dans l’étude de cas réalisé sur l’Île-à-Vache. En fait, le « confort existentiel » que recherche le touriste y joue un rôle essentiel. Il influence le discours hégémonique des acteurs dominants et dicte les décisions d’aménagement des destinations touristiques. Dans le cadre de la production et de la mise en tourisme de l’Île-à-Vache, il permet d’expliquer le mécanisme des d’accumulation capitalistique par dépossession dans le processus de développement géographique inégal.
The article shows how the socio-economic relations that underlie the construction of discourse on tourism development influence the material practices in the space appropriation process. It argues that the power, values, and beliefs are a set of discourses of different groups and classes in a tourist area. These discourses shape, through material practices, the tourism space. It illustrate the entanglement of these complex relationships through the case study conducted on Île-à-Vache. In fact, the "existential comfort" that the tourist research plays a vital role. It influences the hegemonic discourse of the dominant players and dictate management decisions of the tourist destinations. As part of the production and the development of tourism Île-à-Vache, it helps to explain the mechanism of capital accumulation by dispossession in the uneven geographical development process.
Haïti
Île-à-Vache

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.8810
http://journals.openedition.org/etudescaribeennes/8810

Éditeur(s) : HAL CCSD
Résumé : Ghost fishing and its consequences are little known in the French West Indies. In Guadeloupe, no allegation concerning ghost fishing was made public to date. In the absence of objective studies about this phenomenon, it is impossible to quantify the impact of these lost gears on the resource (Chaves et al. 2006). However, the characteristics of small-scale fishing existing in this area let think that it happens indeed that fishing machines are lost: - weather constraints, sometimes of catastrophic type (storms, hurricanes). The fishermen fix less racks (traps) during the period preceding the hurricane season in preparation for possible loss (Komla-Soukha and Bouchereau 2007). Of the 40 000 Caribbean traps around Guadeloupe, about 20 000 are lost each year during hurricane season, but continue to catch fish for many months (Burke and Maidens 2004); - accidents (most common causes after the literature) occurring during a fishing operation are events already well orally brought back (Macfayden et al. 2009); - the voluntary abandonment at sea of material by the fisherman for convenience reasons; - the consequences of conflicts of use (thefts, destruction of fishing gears, boardings of ships). It is the case in the Caribbean area in connection with the interactions related to the stake on resources exploitation (Blanchet et al. 2002).
Coastal Zone Asia-Pacific Conference-World Small-Scale Fisheries Congress
Bangkok, Thailand

hal-00755291
https://hal.univ-antilles.fr/hal-00755291
https://hal.univ-antilles.fr/hal-00755291/document
https://hal.univ-antilles.fr/hal-00755291/file/WSFC2010_Proceedings_Bouchereau.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
TRAMIL is a research program applied to the use of medicinal plants in the Caribbean, established in the 1980s. Significant uses of herbal remedies to address self limiting health problems are identified through participatory ethnopharmacological surveys and are the subject of scientific validation. The results are then disseminated to several audiences.While comprising an international scientific contribution to academic research, the TRAMIL network activities value the popular and local knowledge. This fertile relationship between local knowledge and scientific research draws answers to key challenges for Caribbean societies: improving the health of Caribbean populations first and foremost, but also indirectly developing economic prospects in various sectors (agriculture, industry, tourism, and health).The success of TRAMIL is based on a rigorous methodology and on a noteworthy informal network of collaborators invested at different levels of the program, locally and / or regionally. TRAMIL is one of the few trilingual networks that have been active for nearly forty years, well before the popularization of the Internet, in more than twenty Caribbean territories. It involves people and communities, health care professionals, researchers in many disciplines, and information and documentation professionals.This paper proposes to explore these new ways of working together and the accomplishments to which they give rise by presenting some concrete examples of the TRAMIL program in Puerto Rico and examining the program's website and the complex challenges faced by the stakeholders involved in its implementation.
TRAMIL es un programa de investigación aplicada a la medicina popular del Caribe, iniciado en la década de los ‘80. Su trabajo se basa en llevar a cabo encuestas etnofarmacológicas participativas para identificar usos significativos de remedios de plantas, que son objeto de la validación científica, para tratar problemas comunes de salud. La difusión de los resultados de validación de los remedios con uso significativo completa las líneas de acción de TRAMIL. Al tiempo que representan una contribución científica internacional para la investigación académica, las actividades de TRAMIL constituyen la valoración de los saberes populares y locales. Esta relación fecunda entre el conocimiento local y la investigación científica es una respuesta a desafíos fundamentales para las sociedades del Caribe: mejorar la salud de las poblaciones del Caribe directa y en primer lugar, pero también, indirectamente, desarrollar oportunidades económicas en varios sectores (agricultura, la industria, el turismo y la salud).El éxito de TRAMIL se basa en una metodología rigurosa y una importante red informal de colaboradores que participan en diversas funciones del programa, a nivel de país y regional. TRAMIL es una de las pocas redes totalmente trilingües, activa durante casi cuarenta años, mucho antes de la popularización del Internet, en más de una veintena de territorio caribeños. Asocia especialmente a comunidades, profesionales de la salud, investigadores en muchas disciplinas, y profesionales de la información y documentación.Este trabajo tiene como objetivos explorar las modalidades de cooperación y logros sin precedentes de TRAMIL, presentando algunos ejemplos concretos del programa en Puerto Rico y examinar el sitio Web del programa y la complejidad de los desafíos que han enfrentado los actores involucrados en su implementación.
TRAMIL est un programme de recherche appliquée à l’usage des plantes médicinales dans la Caraïbe, né dans les années 1980. Les usages significatifs des plantes pour répondre à des problèmes de santé sont recensés par des enquêtes ethnopharmacologiques participatives puis font l’objet de travaux scientifiques destinés à les valider. Les résultats sont ensuite diffusés auprès de larges publics.Tout en constituant un apport scientifique international à la recherche universitaire, les activités du réseau TRAMIL s’inscrivent dans la valorisation des savoirs locaux. Cette relation fertile entre savoirs locaux et recherche scientifique dessine des réponses à des défis essentiels pour les sociétés caribéennes : l’amélioration de la santé des populations caribéennes de façon directe et en premier lieu, mais également, de façon indirecte, le développement de perspectives économiques dans des secteurs divers (agriculture, industrie, tourisme, santé).Le succès de TRAMIL repose sur une méthodologie rigoureuse et sur un important réseau informel d’acteurs investis à différents niveaux du programme, sur le plan local et/ou pancaribéen. C’est l’un des rares réseaux entièrement trilingue, actifs depuis près de quarante ans (bien avant la popularisation d’internet), dans plus d’une vingtaine de territoire de la Caraïbe. Il associe notamment les populations, les professionnels de santé, les chercheurs dans de nombreuses disciplines, et les professionnels de l’information et de la documentation.La présente contribution propose d’explorer ces modalités de collaboration inédites et les réalisations auxquelles elles donnent lieu, en présentant quelques exemples concrets du programme TRAMIL à Porto Rico, puis en examinant le site internet du programme et les défis complexes auxquels il a confronté les acteurs impliqués dans sa réalisation.
ACURIL 2017
San Juan, Puerto Rico

hal-01629021
https://hal.univ-antilles.fr/hal-01629021

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Wallace (1951) and Bott (1959) were the first to introduce the idea that the slip on each fault surface has the same direction and sense as the maximum shear stress resolved on that surface. However, this simplified hypothesis is questionable since fault mechanical interactions may induce slip reorientations. Earlier numerical geomechanical models confirmed that the slickenlines (slip vectors) are not necessarily parallel to the maximum resolved shear stress but are consistent with local stress perturbations. This leads us to ask as to what extent the Wallace and Bott simplifications are reliable as a basis hypothesis for stress inversion from fault slip data. Here, a geomechanical multi-parametric study using a 3D boundary element method, covering (i) fault geometries such as intersected faults or corrugated fault surfaces, (ii) the full range of Andersonian state of stress, (iii) fault friction, (iv) fault fluid pressure, (v) half space effect and (vi), rock properties, is performed in order to understand the effect of each parameter on the misfit angle between geomechanical slip vectors and the resolved shear stresses. It is shown that significant misfit angles can be found under specific configurations invalidating the Wallace and Bott assumptions, even though fault friction tends to minimize the misfit. We therefore conclude that in such cases, stress inversions based on fault slip data should be interpreted with care.
ISSN: 0040-1951

hal-01218418
https://hal.archives-ouvertes.fr/hal-01218418
DOI : 10.1016/j.tecto.2015.06.030