Éditeur(s) : UNDP Guyana UNDP Guyana ( Guyana )
Résumé : (Funding) Support for the development of the technical infrastructure and partner training provided by the United States Department of Education TICFIA program.
While the global response to HIV and AIDS has realized several successes in achieving universal access to prevention, care and treatment to date, challenges persist in ensuring equal access to these services for most at risk populations. The epidemiology of HIV reflects a stark disparity in access to prevention and treatment services for neglected most-at risk populations, such as men who have sex with men (MSM). World-wide, MSM often experience higher rates of HIV relative to the total population. The reasons for this dynamic are multi-faceted and include high risk behaviors, and cultural as well as structural barriers. For MSM in developing countries, for example, basic services for prevention and treatment of HIV infection have yet to reach the large majority of men. Homophobia and discrimination limit access of MSM to prevention services and markedly increase vulnerability, as do criminalization of same-sex behavior. Decriminalization of same-sex behavior is a structural intervention for prevention of HIV infection and has recently been embraced by a nonbinding statement from the United Nations (Beyrer C,Clin Infect Dis. 2010 May 15;50 Suppl 3:S108-13) In the Caribbean, all of the above mentioned barriers exist. In fact, recent evidence demonstrates that there is a correlation between the decriminalization of homosexuality and lower rates of HIV (UNAIDS). This correlation is attributed to improved access to services. Therefore, The United Nations Development Program (UNDP) has recently launched an initiative to address the current situation regarding men who have sex with men in Guyana where the HIV prevalence in this population is 19.4% in contrast to 1.8% in the total population. This rapid assessment has been commissioned to supplement two previous studies that were conducted in Guyana in informing the design of upcoming activities to support local capacity building to enhance access to services and respect for the human rights protections for MSM. Unfortunately, in Guyana, like much of the Caribbean, MSM tend to be a hard to reach population, perhaps due to elevated levels of stigma and discrimination and difficulty in accessing men who might participate in high risk same sex behaviors yet do not self-identify as an MSM. As a result, there is a relative paucity of data concerning the knowledge, attitudes and behaviors of this total population in Guyana. (i.e. those who self –identify and those who do not) The baseline report is organized as follows: the methodology is explained followed by the study limitations, the review (literature and desk). The report then proceeds with describing the reality of work and working with sexual and gender minorities in Guyana, the status quo and entry points. The main findings of the capacity assessment and focus groups are then discussed. Issues relating to the uniformed forces and health services providers are then presented followed by discussions and conclusions.

Droits : All rights reserved by the source institution.

Résumé : At the outbreak of war with Spain in 1898, the U.S. Army was very small in numbers. This situation necessitated an immediate call for volunteers. President McKinley's appeal was overwhelmingly answered by a generation that had grown up in the shadow of their elders' Civil War glory. One group answering the call was the First Regiment of the U.S. Cavalry Volunteers, headed by Colonel Leonard Wood, a distinguished army doctor and Medal of Honor recipient. The regiment was actually the brainchild of Theodore Roosevelt, assistant secretary of the navy and Wood's friend. Roosevelt, realizing his own lack of military experience, suggested Wood for the command. The Rough Riders, as the regiment was soon known, comprised 1,250 men, including cowboys, Native Americans and eastern college athletes. Despite their dissimilarities, they were in excellent physical condition'a stark contrast to most of the other volunteer contingents. The Rough Riders departed from Tampa in mid-June without their horses. They landed at Daiquiri on June 22 and two days later served with distinction in a battle at Las Guásimas. Immediately prior to the conflict at San Juan, Colonel Wood was promoted to another field command, enabling Roosevelt as a full colonel to take command of the Rough Riders. On July 1, Roosevelt, having secured a horse, led his forces in a charge up Kettle Hill outside of Santiago. They achieved their goal and later in the day participated in the victory at San Juan Hill. By seizing these heights, American guns commanded the harbor at Santiago. The Spanish position was imperiled and an abortive attempt by the Spanish navy to escape from the harbor was halted with devastating results. Spanish land forces surrendered shortly thereafter. Roosevelt urged the Rough Riders' swift evacuation, fearing the continuing spread of disease. They returned to Montauk, Long Island, where they were held in quarantine before being mustered out in September. More than one-third of the Rough Riders were casualties in the Spanish-American War, a fact that has led some observers to criticize Roosevelt for unnecessary risk-taking. Nevertheless, the Rough Riders became heroes to the American public and Roosevelt emerged as a major national figure.
(Funding) Funded in part by the Institute for Museum and Library Services (IMLS), Ephemeral Cities Project.
Tampa |z 1271000 |2 ceeus
Hillsborough County |z 12057 |2 ceeus
United States of America -- Florida -- Hillsborough County -- Tampa
United States

Droits : All rights reserved. 2005.
D20-012

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
OBJECTIVE: To assess the relationship between hypertension and perceived material insecurity in a disadvantaged Caribbean population. PATIENTS AND METHODS: We used data from a cross-sectional study involving 2420 disadvantaged subjects aged 18-69 years, included consecutively at three Guadeloupian health centers. Hypertension was diagnosed over two consultations with a total of six blood pressure measurements. Perceived material insecurity was assessed using a closed-ended question. RESULTS: The prevalence of hypertension was estimated at 17.7% among subjects who believed their material situation would improve in the future, at 28.2% among those who believed it would remain the same, and at 43.3% among those who believed it would deteriorate. A multivariate logistic regression analysis showed that hypertension risk more than doubled (OR: 2.35 - P: 0.002) among subjects who believed that their material situation would deteriorate in the future compared to those who believed that their situation would improve, with no significant sex-related differences. This relationship was especially strong among subjects aged 40 years or more (OR: 3.30 - P<10(-3)), and among subjects with low education level (OR: 3.81 - P: 0.003), but was independent of the other tested variables. CONCLUSION: In this disadvantaged population, perceived material insecurity is a psychosocial factor strongly associated with hypertension, independently of subjects' risk behaviors. Subjects aged 40 years or more and subjects with a low education level seem the most vulnerable.
ISSN: 0003-3928

hal-00739792
https://hal.univ-antilles.fr/hal-00739792
https://hal.univ-antilles.fr/hal-00739792/document
https://hal.univ-antilles.fr/hal-00739792/file/HTA_et_precarite_percue_en_guadeloupe_-_Copie.pdf
DOI : 10.1016/j.ancard.2012.04.023

Éditeur(s) : HAL CCSD John Libbey Eurotext
Résumé : International audience
Environmental health risk assessment is commonly used in France for risk management purposes. The Methodology section of the "Société française de santé environnement" (French Society for Environmental Health) seeks to improve the utility and implementation of risk assessment in France. An initial operational objective is to make a list of short-, intermediate- and long-term improvements. This inventory is based in part on the experience and expertise of society members in this area and in part on their analysis of "Science and Decisions: Advancing Risk Assessment" (National Research Council 2009). In this paper, the Society recommends modifications in the indications for and use of risk assessments, during each of the four stages of the process: hazard identification and dose-response assessment, exposure assessment, risk characterization, and results interpretation. Some may be implemented now, while others need consensus building or research because of gaps in knowledge. Environmental health risk assessment must be understood as a decision tool for risk management in situations of uncertainly. Thus, appropriate linkage is required between decision making and assessment, and between the methods and the expected results.
L'évaluation des risques sanitaires est fréquemment utilisée en France dans les processus de décision en santé environnementale. La section " Méthodologie d'évaluation des risques sanitaires " de la Société française de santé environnement (SFSE) s'est donnée pour objectif de proposer des éléments de réflexion et des outils méthodologiques en vue d'améliorer l'utilité et les pratiques de l'évaluation des risques sanitaires. Un premier objectif opérationnel est l'inventaire des améliorations possibles à court, moyen et long termes à apporter à la démarche et à son utilisation. Ce travail s'est fondé, d'une part, sur la pratique et l'expertise des membres de la section, et, d'autre part, sur une lecture critique du rapport " Science and Decisions : Advancing Risk Assessment " publié en 2009 par le National Research Council et portant également sur les évolutions de la démarche. Dans cet article, la section restitue les conclusions de cet inventaire critique et propose un certain nombre d'améliorations en termes d'indications et d'utilisations de l'évaluation des risques sanitaires pour chacune des quatre étapes : identification des dangers et relation dose-réponse ; évaluation de l'exposition ; caractérisation des risques ; et interprétation des résultats. Certaines recommandations peuvent être mises en oeuvre immédiatement ; d'autres, en préalable à leur mise en oeuvre, nécessitent un consensus ou encore de la recherche car les connaissances manquent. En conclusion, la section insiste sur le fait que l'évaluation des risques sanitaires doit être comprise comme une aide à la décision en situation d'incertitude ; l'articulation entre le contexte décisionnel et l'évaluation, sa méthodologie et les résultats attendus est donc primordiale.
ISSN: 1635-0421

ineris-00963325
https://hal-ineris.archives-ouvertes.fr/ineris-00963325
DOI : 10.1684/ers.2011.0435
INERIS : EN-2012-016

Éditeur(s) : HAL CCSD Institut de Géographie Alpine
Résumé : International audience
The international symposium on «Urban Growth and Natural Hazards, in particular in Developing Countries» was held in the University Blaise Pascal, Clermont-Ferrand (France) on December 2 and 3, 1994. This meeting brought together about 70 research people, Ph.D. students, and professionals from France and 12 countries, representing universities, research agencies, as well as government and private companies. The symposium aimed to gather specialized people who are engaged and acting in programmes on hazard appraisal, risk prevention and urban management in city environment. These people aimed to compare experiences acquired in two different fields: on the one hand urban growth and its consequences, and on the other hand, natural hazards and effects, in particular in Developing Countries.Half-way through the International Decade for Natural Hazard Disaster Reduction, we strove to reconcile two points of view usually distincts: nature-oriented research and society-oriented research on hazards. These convergent approaches should merge, not only to improve knowledge of natural hazards and risks, but also to cope with hazard and risk situation on a day-basis in a city. We also choose to study both approaches in Developing Countries (DC) because most of the large cities of the world already are or will be located there in near future. In addition, city location in DC coincides with tropical areas where natural hazards are most frequent threats to life, in particular in mountains, on seashores, and on active convergent plate margins. We stress the fact that the 3 following topics are often lacking in studies which have been carried out on natural hazard appraisal and management. 1) How should we include social and economical factors, and particularly a sound analysis of vulnerability of people and values at risk ? 2) How should we cope with hazard management in large cities of Developing Countries ? 3) What is the specific task of research people in hazard case studies engaged in urban environment and management?Three themes correspond to the three sessions of the symposium. (1) Natural hazards and environmental factors : inventory, diagnostic and classification, (2) Vulnerability of urban society and environment : concepts, approaches, and classification, (3) Tools for urban risk prevention and risk management in case of crisis and catastrophes.
Ce numéro de la Revue de Géographie Alpine reprend une dizaine parmi les 41 contributions exposées par des chercheurs français et étrangers lors du colloque international « Croissance urbaine et risques naturels dans les pays en développement » qui s'est déroulé à l'Université Blaise Pascal, Clermont-Ferrand, les 2 et 3 décembre 1994. L'objectif général du colloque était de rassembler les diverses compétences existant en France et à l'étranger dans le domaine de l'évaluation et de la gestion des risques naturels et de confronter les expériences acquises à l'interface entre les villes en croissance et le champ d'action des phénomènes naturels créateurs de risques. Le colloque a donc réuni des chercheurs, des doctorants et des praticiens français et leurs collègues étrangers chargés de prévention, de gestion des risques naturels et de gestion urbaine, principalement dans les grandes villes des pays en développement (P.E.D.).Parvenus à mi-chemin de la Décennie Internationale pour la Prévention des Catastrophes Naturelles, nous avons porté des regards croisés sur les approches naturalistes et sociologiques des risques naturels. Il est maintenant nécessaire de faire converger ces approches, non seulement dans la connaissance des menaces et des risques, mais dans la gestion du risque quotidien en milieu urbain. Nous avons concentré ces approches dans les pays en développement ; en effet, le site de leurs grandes villes coïncide souvent avec le champ d'action des phénomènes naturels générateurs de risques, notamment dans la zone intertropicale et en particulier dans les marges continent ales actives (par exemple autour du Pacifique).Nous avons porté l'accent sur 3 points principaux, qui semblent en partie faire défaut dans les études et les méthodes actuellement mises en oeuvre dans la gestion des risques naturels : 1) comment prendre en compte les aspects socio-économiques, en particulier les types d'analyse des vulnérabilités ? 2) comment aborder la gestion des risques en milieu urbain dans les P.E.D. ? 3) quel rôle doit jouer le chercheur en Sciences de l'Homme, de la Société et de la Terre dans les analyses, les expertises consacrées aux risques et surtout dans leur gestion globale, à la charnière des sociétés citadines précaires et des milieux « naturels » contraignants ?Les contributions ont été regroupées, exposées et discutées lors du colloque sous forme de 3 thèmes. (1) Les phénomènes naturels créateurs de dommages (= menaces) : diagnostic, inventaire et typologie, (2) Les vulnérabilités des sociétés et des espaces urbanisés : concepts, typologie et modes d'analyse, (3) Les outils d'aide à la prévention et à la gestion du risque en milieu urbain.
Colloque international : "Croissance urbaine et risques naturels dans les pays en développement"
Clermont-Ferrand, Université Blaise Pascal, France

ISBN : 0035-1121
hal-01165252
https://hal.archives-ouvertes.fr/hal-01165252

Éditeur(s) : HAL CCSD John Libbey Eurotext
Résumé : International audience
Chemical risk assessment is a tool used in decision-making processes concerning situations of scientific uncertainty. Approaches to risk assessment in occupational and environmental health share the same objective of risk prevention. Nevertheless, the methods for both differ depending on whether the goal is to enforce regulations or conduct expert assessments and studies. These differences are stronger in occupational health, for which regulations require risk assessments at the work station, to classify and prioritize exposure situations to implement occupational risk prevention strategies. Risk assessment thus has somewhat different meanings in occupational and environmental health. This article attempts to clarify the different terms used in the different contexts and to describe the similarities and differences of the two approaches.
ISSN: 1635-0421

hal-00936256
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00936256
DOI : 10.1684/ers.2013.0646

Éditeur(s) : HAL CCSD
Résumé : International audience
Primary spontaneous pneumothorax (PSP) is common and affects young and active patients. Guidelines are accurate about diagnosis and treatment indications, but the initial optimal management remains unclear. Smoking is the main risk factor and smoking cessation must be systematically advised. If simple surveillance is acceptable for small PSP and/or paucisymptomatic patient with PSP, exsufflation or hospitalization with chest tube drainage remains the standard treatment in other situations. Ambulatory management is possible and could become the next standard of care. © 2015, Société de réanimation de langue française (SRLF) and Springer-Verlag France
Reanimation

hal-01326967
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01326967
DOI : 10.1007/s13546-015-1156-1

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
In spite of several studies on factors affecting nitrogen (N) export in water, the spatiotemporal variability of N export is rarely addressed. This review aims at discussing the different factors involved in N export in water and the intra-annual variability of N occurrences in rivers at a watershed scale. From the analysis of the existing works some recommendations on future research work are proposed regarding (i) other N forms than nitrate being systematically considered for routine analysis or experimental studies (at least Kjheldal nitrogen), (ii) hydrologists and biogeochemists working together to better understanding of N dynamics according to water pathways, especially during “situations at risk,” (iii) water quality monitoring being reinforced both spatially and temporally, especially thanks to high frequency instrumentation, and (iv) accurate data on watersheds needed to give better explanations of N variations. We argue that a better understanding of spatiotemporal variability could greatly enhance the remediation of N export impacts, which is crucial to anticipate the impacts of global changes
ISSN: 1064-3389

hal-01195736
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01195736
DOI : 10.1080/10643389.2015.1010432

Résumé : The use of acoustical systems in various human activities in the ocean (industry, defence, science) raises the issue of their impact upon marine mammals populations. Several serious accidents linked to the use of naval sonars led the military, industrial and scientific communities to investigate the potential dangers of their own activity. This report aims at identifying the risks for the cetaceans linked to the use of acoustic and seismic systems currently used for oceanographic science. The analysis proposed here stays within the frame of bibliography synthesis and elementary modelling, and brings no new scientific elements on the topic. An overview of the status of cetacean populations is given first, with a summary of the possible acoustical threats. Risks are classified and described, insisting on the cases of massive stranding events. The present status of knowledge about auditory characteristics of cetaceans is summarised, and the definition of an objective threshold for acoustical risk is discussed ; the usually-admitted values are finally retained, despite of their evident limitations. The report presents also the emission characteristics of the various acoustic and seismic systems used in oceanographic, emphasising the ones operated by Ifremer; for the potentially harmful ones (according to the currently-used criteria) a model is proposed for the radiated acoustical intensity field, giving the extent of risk areas. This analysis concludes to the harmlessness of most systems, excepted heavy seismics and at a lesser degree low-frequency multibeam echosounders. Finally a variety of possible mitigation measures are presented and discussed; the regulations imposed by some countries are detailed. The report finally recommends both short-term measures aimed at limiting the potential risks, and longer-term actions for participating in the general effort of scientific and technological research in this field.
L'emploi des systèmes acoustiques dans les diverses activités humaines en milieu océanique (industrielles, de défense, scientifiques) pose le problème de leur impact sur les populations de mammifères marins. L'évidence de plusieurs événements graves liés à l'utilisation de sonars navals a amené les communautés militaires, industrielles et scientifiques à s'interroger sur les dangers potentiels de leurs propres activités. Le présent rapport tente de cerner les risques, pour les Cétacés, liés à l'emploi des systèmes acoustiques et sismiques couramment mis en oeuvre pour la recherche océanographique. L'analyse proposée ici reste à un niveau de synthèse bibliographique et de modélisation élémentaire, et n'offre pas d'éléments scientifiques nouveaux sur la question. On commence par donner un panorama de la situation des populations de cétacés et des agressions sonores qui les menacent. Les risques acoustiques sont répertoriés et décrits, en insistant sur les cas avérés d'échouages massifs. L'état actuel de connaissances sur les caractéristiques auditives des cétacés est résumé, et la définition d'un seuil objectif de risque acoustique est discutée ; on retient par défaut les valeurs de seuils généralement admises actuellement, en dépit de leurs limitations évidentes.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2007/rapport-2390.pdf
http://archimer.ifremer.fr/doc/00000/2390/

Éditeur(s) : HAL CCSD
Résumé : The sandy coasts of Languedoc-Roussillon are a zone vulnerable to erosion and flooding. These hazards are generally associated with a combination of natural factors such as waves, wind, rising sea levels and the importance of sediment supply, and are therefore worsened during storms. For the management of such risks, a better knowledge of the hydrodynamic phenomena occuring from the surf zone through to the coastal scale is essential. This need led to the development of a numerical modelling platform consisting of the 3D ocean circulation model Symphonie, usually dedicated to regional and coastal scales, which was modified to include the wave forcing, modeled by the WaveWatch III or Swan models. Using this platform the entire littoral and coastal regions can be accurately represented. The model was tested in several academic cases. Measurements on the barred beach of Sète during the winter of 2008-2009 served to refine the model, which is able to successfully reproduce the characteristics of the currents in coastal areas, drifts or rip currents over more complex bathymetries and also the vertical profiles of currents. To validate the model on the inner-shelf, we compared the simulations with measurements taken during a winter storm in 2004 around the mouth of the Têt river, as well as during storms in 2007 and 2008 in the Gulf of Aigues-Mortes. Currents are generally well reproduced. However, the scope of wave action seems limited to a depth of 30m. The characteristics of our model allow a good reproduction of the currents at all scales and the 3D nature of the model permits a more precise calculation of the shear stress and bottom current responsible, respectively, for the suspension and advection of sediments.
Le littoral sableux du Languedoc-Roussillon est un système vulnérable aux risques d'érosion et de submersion. Ces aléas sont liés à la conjonction des facteurs naturels que sont les vagues, vent, élévation du niveau de la mer et apports sédimentaires et sont donc aggravés en période de tempête. En vue d'une gestion des risques, une meilleure connaissance des phénomènes hydrodynamiques de l'échelle littorale à l'échelle côtière est essentielle. Ce travail a conduit à la réalisation d'une plateforme de modélisation numérique composée du modèle de circulation océanique 3D Symphonie, traditionnellement dédié aux échelles régionales et côtières, qui a été modifié pour inclure le forçage par les vagues, modélisées par les modèles Wavewatch III ou Swan, et ainsi étendre sa validité au littoral. Le modèle a été testé sur des cas académiques littoraux. Des mesures sur la plage à double barres de Sète pendant l'hiver 2008-2009, ont également servi à parfaire le modèle qui reproduit ainsi avec succès les caractéristiques des courants en zone littorale : la dérive, les courants sagittaux sur des bathymétries plus complexes et les profils verticaux des courants. Pour valider le modèle à des échelles plus côtières, nous avons confronté ses résultats à des mesures réalisées pendant une tempête hivernale en 2004 aux alentours de l'embouchure de la Têt, mais également sur des tempêtes de 2007 et 2008 dans le Golfe d'Aigues-Mortes. Les courants sont globalement bien reproduits. Les zones d'action des vagues semblent limitées aux zones de profondeur inférieure à 30 m. Notre modèle autorise une reproduction correcte des courants à toutes les échelles et sa nature 3D permet un calcul plus précis de la tension de cisaillement de fond et du courant près du fond, responsables respectivement de la mise en suspension et de l'advection des sédiments.
https://tel.archives-ouvertes.fr/tel-00680405

tel-00680405
https://tel.archives-ouvertes.fr/tel-00680405
https://tel.archives-ouvertes.fr/tel-00680405v2/document
https://tel.archives-ouvertes.fr/tel-00680405/file/2011_MICHAUD.pdf

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Hand disinfection with alcohols-based hand rubs (ABHRs) are known to be the most effective measure to prevent nosocomial infections in healthcare. ABHRs contain on average 70% by weight of one or more alcohols. During the hand rubbing procedure, users are exposed to these alcohols not only through dermal contact, but also via inhalation, due to the physical and chemical properties of alcohols volatilizing from alcoholic solutions or gels into the air. Ethanol ingestion is well known to increase risks of several diseases (affecting the pancreas, liver, cardiovascular system…), but there is a lack of knowledge about the effects of exposure to other alcohols (including n- or isopropanol) via inhalation and dermal contact, despite the worldwide use of ABHRs. This work aims at discussing possible health effects related to unintentional alcoholization (via inhalation and dermal contact) from professional ABHR usage to suggest the need for more research in this area (but not to question the value of ABHRs). Based upon an average of 30 hand rubbings per healthcare professional per day, it can be assumed that a healthcare worker may be exposed to a maximum 5,500 mg/m(3) per work shift, five times above the recommended occupational time weighted average limit. Thus, in order to answer the question posed in the title, studies on spatial and temporal variability of alcohol emission from ABHRs in real world situations and studies on certain high risk individuals are needed.
ISSN: 1660-4601

hal-01122305
https://hal.archives-ouvertes.fr/hal-01122305
PUBMED : 20948945
DOI : 10.3390/ijerph7083038
PUBMEDCENTRAL : PMC2954566

Éditeur(s) : HAL CCSD Lippincott, Williams & Wilkins
Résumé : International audience
BACKGROUND: Exposure to solvents during pregnancy has long been suspected of increasing the risk of congenital malformations, but the lack of prospective assessment of specific solvent exposures has prevented definitive conclusions. METHODS: In a cohort of 3421 pregnant women in Brittany (2002-2006), occupational solvent exposure was assessed from self-report during pregnancy and from a job-exposure matrix. Congenital malformations were diagnosed among live births, stillbirths, and medical pregnancy terminations. In a nested case-control sample, urinary concentrations of 10 metabolites of glycol ethers and chlorinated solvents were measured in maternal samples collected during early pregnancy (n = 79 cases, 580 controls). RESULTS: Dose-response trends linked occupational solvent exposure (both self-reported and based on a job-exposure matrix) to the risk of major congenital malformations--especially oral clefts, urinary tract malformations, and male genital malformations. Detection of some glycol ether metabolites and trichloroacetic acid in urine was associated with increased risks of oral clefts and of urinary tract and limb defects. CONCLUSIONS: This prospective study, using three independent methods of exposure assessment, suggests several specific associations between solvent exposure during early pregnancy and congenital malformations. Results based on urinary biomarkers, although limited by small numbers, identify work situations that require further investigation.
ISSN: 1044-3983

hal-00875918
https://hal.archives-ouvertes.fr/hal-00875918
DOI : 10.1097/EDE.0b013e31826c2bd8
PUBMED : 23007043

Éditeur(s) : HAL CCSD
Résumé : In order to minimize CO2 atmospheric concentration, a solution consists in sequestrating CO2 in geological reservoirs. To estimate long term risks, it is necessary to quantify the couplings between reaction processes as well as structural and hydrodynamical modifications. We realised two experimental benches enabling injecting CO2-enriched-brine in conditions corresponding to in situ storage (T < 200 oC and P < 200 bar) and developed
an experimental protocol using X-Ray microtomography and fluid and rock analyses in order to measure the variations of physical and chemical parameters.
The study of carbonated reservoirs near the injection well, allows quantifying different k-phi relationships depending on the dissolution processes and triggered by the local fluid chemical composition and initials conditions. Away from the injection well, we observe carbonate precipitation decreasing the permeability. The study of fracturated caprock samples shows that alternative percolation of CO2-enriched-brine and CO2 gas increases the fracture permeability.
The study of silicated rocks indicates carbonate precipitation in zeolite sandstone and sintered dunite grains. Nevertheless, in zeolite sandstone we also observe the precipitation of clay particles located in the uid pathways which decrease strongly the permeability.
Afin de minimiser la concentration en CO2 dans l'atmosphère une solution consiste à le séquestrer dans les réservoirs géologiques. Pour évaluer les risques à long terme, il est nécessaire de quantifier les couplages entre les processus réactionnels et les modifications structurales et hydrodynamiques. Dans cette optique, nous avons construit deux dispositifs expérimentaux permettant d'injecter des saumures chargées en CO2 dans les conditions de stockage (T < 200 °C et P < 200 bar) et mis en oeuvre un protocole expérimental utilisant la microtomographie RX et l'analyse des roches et des fuides pour quantifier les variations des paramètres physiques et chimiques. Dans le cas des réservoirs carbonatés, on observe, près du puits d'injection, une forte variabilité des relations k-phi en fonction du régime de dissolution contrôlé par la chimie locale du fluide, ainsi que par les conditions initiales. A plus grande distance, on observe des processus de précipitation diminuant fortement la perméabilité. L'étude des roches de couverture fracturées (argilite) a montré qu'une percolation alternée d'une saumure chargée en CO2 et de CO2 gaz augmentait la perméabilité de fracture. Dans le cas des roches silicatées, la précipitation de carbonates est mise en évidence aussi bien dans les grès à zéolites que dans les frittés de dunite de San Carlos. Cependant, dans les grès à zéolites, la précipitation d'une phase argileuse est observée dans les chemins d'écoulement et engendre une forte diminution de la perméabilité.
https://tel.archives-ouvertes.fr/tel-00416408

tel-00416408
https://tel.archives-ouvertes.fr/tel-00416408
https://tel.archives-ouvertes.fr/tel-00416408/document
https://tel.archives-ouvertes.fr/tel-00416408/file/These_Luquot.pdf

Éditeur(s) : Universite Montpellier II
Résumé : Since 1980, the expansion of a green macro-alga: Valonia aegagropila (C Agardh) is observed in Salses-Leucate lagoon (France). It is currently distributed in the north of the lagoon with important biomasses (40 gDW/m²) eroding the cover of Zostera noltii. The free form of the alga can be transported with the surface or bottom currents depending on seasons. It multiplies mainly by vegetative reproduction. There are few studies on the ecophysiological capacities of V. aegagropila. This work tries to answer why (physiological adaptation) and how (mechanical process of transport) the alga invaded the lagoon, with an approach including observations, experiments in controlled environment and biological and hydrodynamic models. The growth capacities depend on temperature and light intensities, the nutrients absorption rates and internal nitrogen and phosphorus internal quotas were measured and modelled using a Droop model based on internal quota. Vertically transport was studied with laboratory experiments and measurements of biomass transport were made into the lagoon. The biological model (growth, vertical transport, mortality) was coupled to the MARS 3D hydrodynamic model with a meshgrid of 160m. The results show an adaptation of the alga to low availability of phosphorus and an annual growth of biomass controlled by the availability of nutrient during winter. The alga seems to occupy the whole zones where growth is optimal and the risk of invasion of the southern part of the lagoon is limited. This work opens on research prospects on an ecological model (confronting physiological capacities and competition of V. aegagropila, Zostera noltii, green algae and primary production), new physiological experiments, ecological observations and potential valorisation of V. aegagropila.
Depuis 1980, est observée dans l'étang de Salses-Leucate l'expansion d'une macro-algue verte : Valonia aegagropila (C. Agardh). En 2004, elle était présente sur la presque totalité de la moitié nord de la lagune avec des biomasses importantes (jusqu'à 600 gPS/m²). L'algue envahit et érode également la couverture d'herbiers garant de la biodiversité, de la productivité et de la stabilité de l'écosystème. V. aegagropila se reproduit essentiellement de manière végétative (fragmentation des thalles) et possède la particularité de retenir de l'oxygène de la photosynthèse dans sa structure sphérique. Cet oxygène piégé lui donne la possibilité de mouvement sur la verticale et d'être transportée dans le domaine par les courants. Les conditions physico-chimiques de l'étang présentent de fortes variations saisonnières en salinité, en température et en turbidité, ainsi que des apports nutritifs faibles : la production primaire est principalement limitée par le phosphore. Il existe malheureusement peu d'informations sur V. aegagropila ainsi que trop peu de connaissances sur son écophysiologie. Elle semble vivre dans des milieux plutôt oligotrophe dans des régions tropicales à sub-tropicales. Ce travail basé sur une approche d'observations de terrain, d'expérimentations en milieu contrôlé (en laboratoire) et de modélisation des processus, a permis d'une part d'explorer les capacités adaptatives physiologiques de V. aegagropila aux conditions environnementales de l'étang et d'autre part de mettre à jour les modes de fonctionnement de la dynamique spatio-temporelle de la population. Les capacités de croissance ont été mesurées sur un large spectre de température et de lumière. Les capacités d'absorption des sels nutritifs dans l'eau et les facultés de l'algue à stocker l'azote et le phosphore dans ses tissus ont également été étudiées. D'autre part, un modèle de dynamique des populations a été conceptualisé puis développé. Les processus pris en compte dans ce modèle sont la croissance de l'algue (modèle à quota interne), la flottabilité de l'algue et la mortalité par surdensité. Ces processus ont été paramétrés en majeure partie par des expérimentations réalisées en laboratoire. Ce modèle 0D a par la suite était couplé au modèle hydrodynamique MARS3D (modèle Ifremer) mis en place sur la lagune de Salses-Leucate, utilisant deux grilles de calcul (160m ou de 80m de résolution). Les simulations réalisées permettent d'appréhender les capacités spatio-temporelles de la croissance de l'algue dans l'étang, le turnover annuel de la biomasse totale et les attracteurs de biomasse du système sous différents évènements météorologiques. Ces résultats sont comparés avec les répartitions cartographiques de la population observées in situ en 1999 et 2004 et des flux de biomasses mesurés au cours d'observations de terrain entre juin 2003 et septembre 2004. L'ensemble des résultats montre d'une part une adaptation de l'algue à évoluer dans un milieu pauvre en phosphore et d'autre part une croissance annuelle de la biomasse totale qui est principalement contrôlée par les apports hivernaux en sels nutritifs dans la lagune. Les résultats des simulations montrent également que V. aegagropila semble occuper à présent la majeure partie des zones favorables à sa croissance. Il est également montré que si sa capacité de mouvement peut favoriser la dispersion d'individus dans la lagune et accélérer la croissance de la population pour de faibles biomasses initiales, cette même capacité de mouvement joue plutôt un rôle de régulation de la population lorsque la biomasse totale devient importante. On peut penser que le risque de colonisation de l'herbier à zostère de la partie sud de la lagune (bassin de Salses) est limité. Ce travail ouvre enfin des perspectives de recherche sur l'amélioration du modèle de dynamique des populations de l'espèce, sur de nouvelles expérimentations à réaliser ou encore sur la surveillance écologique du milieu. Des propositions sont faites pour concevoir un modèle écologique confrontant les capacités physiologiques des macrophytes (algues vertes, Valonia et zostères) afin d'apréhender les phénomènes de compétitions et les modes de fonctionnement du réseau trophique de la lagune de Salses- Leucate. Des pistes sur la valorisation de la matière algale de V. aegagropila sont enfin proposées.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/these-2453.pdf
http://archimer.ifremer.fr/doc/00000/2453/

Éditeur(s) : HAL CCSD Elsevier
Résumé : The Gulf of Aigues-Mortes (NW Mediterranean Sea) is a midshelf zone whose scale is an intermediate between the nearshore scale (0–10 m depth) and the coastal scale (including the whole continental shelf). Its hydrodynamics is investigated for the first time. ADCP, CTD and thermosalinograph data were collected during three short cruises (HYGAM; March 6–7, 20–21, April 5–6, 2005). They were scheduled approximately every 15 days to sample the gulf circulation under different weather conditions. Moreover, the cruise data were used to validate the Symphonie model, a 3D primitive equations circulation model. The circulation features displayed by in situ data were well reproduced by Symphonie. A downscaling modelling approach was implemented, the largest scale being obtained by the replay of the MFSTEP regional model of the North-Western Mediterranean Sea. The analysis, closely coupling in situ measurements and model results, provides information that would not have been obtained using data separately. The great variability of the oceanic circulation at this scale is well evidenced. Winds are the main forces, not only locally but also at a larger scale. North winds generate coherent structures interacting with the general Mediterranean circulation. The explanation of the induced currents is then not straightforward, some of them being, for example, northward. South and southeast winds reinforce the sloping surface, the latter allowing the geostrophic equilibrium with longshore currents. This study, focused on the end of winter 2004–2005, also enhances the heat fluxes from offshore to nearshore, as well as the initiation of shelf dense waters. The knowledge of the midshelf oceanic circulation is then applied to run a numerical experiment which describes both the dispersion of a fictive contaminant from a point S (at the centre of the GAM), and evaluates the risk of contamination of the beaches along the GAM shores.
ISSN: 0278-4343

hal-00196620
https://hal.archives-ouvertes.fr/hal-00196620
DOI : 10.1016/j.csr.2007.06.006

Éditeur(s) : HAL CCSD Presses université de Laval
Résumé : International audience
This article aims to specify the challenges related to adapting the Disability Creation Process (DCP) model to the experience of chronic disease, specifically Human immunodeficiency virus (HIV). In this perspective, a conceptual clarification is proposed because the DCP is mainly used to study populations in situations of disability due to motor, sensory, mental or behavioral disabilities. However, this model seems to be able to adequately read the specific experience of HIV, and help to understand differently life trajec-tories of people living with HIV (PLHIV). Indeed, HIV infection, despite its status as a "chronic disease", continues to contribute to the risk of social isolation. Body modifications induced by the disease or its treatment has an impact on how others view PLHIV. They expose the visibility of HIV status and, ultimately, the fear of social exclusion. In this respect, the analysis of the DCP may allow us to understand the varia-tions in the quality of social participation and identify the phases of vulnerability by focusing on body image in particular induced by the infection or treatments. This approach provides the opportunity for new insight into the influence of social environments (particularly health management or community support) with re-gards to the lifestyle and the daily experiences of socially disadvantaged people.
Cet article tente de spécifier les enjeux d’une adaptation du modèle du Processus de production du handicap (PPH) au vécu de la maladie chronique, et plus spécifiquement du virus de l’immunodéfi-cience humaine (VIH). Dans cette perspective, un éclaircissement conceptuel est proposé, car le PPH a principalement été utilisé pour étudier les populations vivant des situations de handicap liées à des incapa-cités motrices, sensorielles, intellectuelles ou comportementales. Ce modèle semble toutefois en mesure de renouveler la lecture de l’expérience spécifique du VIH, et d’aider à saisir autrement les trajectoires de vie des personnes vivant avec le VIH (PVVIH). En effet, l’infection au VIH, malgré son statut de « maladie chronique », demeure associée à un risque d’isolement social. Les modifications corporelles induites par la maladie ou par son traitement confronte les PVVIH au regard de l’autre. Elles exposent à la visibilité du statut sérologique et, in fine, à la peur de l’exclusion sociale. Dans ce cadre, l’analyse du Processus de production du handicap peut permettre de comprendre les variations de la qualité de la participation sociale et d’identifier les phases de vulnérabilité en s’intéressant notamment au rapport au corps induit par l’infection et les traitements. Cette approche offre l’opportunité d’un nouvel éclairage sur le poids des envi-ronnements sociaux (notamment des dispositifs de prises en charge sanitaire ou d’accompagnement communautaire) sur les habitudes de vie et l’expérience quotidienne d’un public fragilisé socialement.
ISSN: 1499-5549

hal-01681423
https://hal.archives-ouvertes.fr/hal-01681423

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Sur la terre ferme, la sécurité est devenue un thème récurrent de la vie politique, des imaginaires voire de la réalité. Dans le monde de la croisière au contraire, la communication vend un univers idyllique. Or la réalité de la vie à bord du navire n’est pas faite que de bonheur, et les armateurs, les voyagistes, les équipages et les autorités administratives anticipent des situations qui mettent en péril les passagers. La gestion des épidémies ne se limite pas à la grippe H1N1, moment exceptionnel qui cache la réalité fréquente des épidémies de gastro-entérite. Le quotidien sécuritaire est aussi constitué par les risques plus traditionnels : le feu et le naufrage. La croisière également s’accompagne de viols et violences sur des croisiéristes, voire de disparitions de passagers. Ces trois dangers de la croisière font l’objet de mesures de santé publique, de définition de normes de sécurité internationales depuis 1914, et de mesures législatives récentes, puisque le dernier texte a été promulgué par le président Obama en juillet 2010. L’Europe montre un retard important dans l’organisation de cette politique, gage de développement de l’industrie de la croisière.
On land, security has become a recurring theme in the political life of the imagination or reality. In the world of cruising the contrary, communication sells idyllic world. The reality of life on the ship is not made that happiness, and shipowners, operators, crews and administrative authorities anticipate situations that endanger passengers. Outbreak management is not limited to the H1N1 exceptional moment that hides the reality of frequent outbreaks of gastroenteritis. The daily safe is also constituted by the more traditional risks: fire and sinking. The cruise also accompanied by rape and violence on cruise or disappearances of passengers. These three dangers of the cruise are the subject of public health measures, definition of international safety standards since 1914, and recent legislation, since the final text was issued by President Obama in July 2010. Europe shows a significant delay in the organization of the political guarantee for the development of the cruise industry.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5220
http://journals.openedition.org/etudescaribeennes/5220

Résumé : Les pathologies inflammatoires démyélinisantes primitives du système nerveux central (SNC) sont dominées par deux entités : la sclérose en plaques (SEP) et la neuromyélite optique (NMO). Ces deux pathologies se différencient par : 1. leur phénotype, la NMO se caractérisant par une myélite extensive dans le plan transversal et longitudinal et peu de lésions encéphaliques initiales ; 2. leur sévérité, le pronostic de la NMO étant moins bon que celui de la SEP ; 3. leur mécanisme immunologique, puisque l’immunité humorale domine nettement dans la NMO, cette pathologie répondant peu ou pas aux traitementshabituellement prescrits dans la SEP. Un anticorps sérique (IgG-NMO) a été retrouvé chez les patients atteints de NMO avec une sensibilité de 50-70% et une spécificité de 90-100%. Cet anticorps a pour cible le principal canal hydrique du SNC, l’aquaporine-4 (AQP4), qui se situe principalement sur les pieds astrocytaires jalonnant la barrière hémato-encéphalique. La SEP est relativement familière des neurologues car décrite sur le plan épidémiologique et dans son histoire naturelle depuis plus d’un siècle à travers de larges séries réalisées parfois en population générale. Son approche thérapeutique progresse suite à des essais contrôlés qui s’accumulent depuis maintenant près de 20 ans. Toutefois, la majorité des travaux ont été effectués chez les populations Caucasiennes en raison de sa plus grande fréquence dans ces populations. A l’inverse, la NMO garde encore un relatif mystère à cause de sa relative rareté, l’établissement très récent de critères diagnostiques et une physiopathologie très récemment éclaircie par la découverte de l’IgG-NMO qui a indiscutablement suscité un regain d’intérêt de cette affection. Ainsi, son incidence est quasiment inconnue de même que sa susceptibilité génétique. La progression du handicap de la NMO qu’il soit visuel ou moteur à l’évidence sévère, ne repose toujours pas sur des chiffres précis, la description des lésions neuroradiologiques reste encore très embryonnaire. Enfin, même s’il existe un consensus pour traiter énergiquement les poussées de NMO et les espacer, il n’existe quasiment aucune étude prospective.
Introduction: Aim of the study is to describe épidemiology, phenotype and treatment of demyelinating inflammatory diseases of the central nervous system (CNS) namely multiple sclerosis (MS) and neuromyelitis optica (NMO) in French West Indies.Epidemiology: MS emerged in the French West Indian (FWI) population with an incidence of 1.27/100 000 (CI 95%: 1.16-1.38) for the period 1992-2007 while incidence of NMO remained stable at 0.19/100,000 (CI 95%: 0.15–0.23). Both migration in Metropolitean France (MF) and decrease of sun exposure were risk factors for MS acquisition in FWI. Phenotype and treatment of NMO: NMO is a very rapidly disabling disease with median times to reach DSS 3, 6 and 8 of one year, 8 years and 22 years respectively. However, treatment by plasma exchanges were shown to reduce sequellae of NMO attacks ; mitoxantrone and rituximab reduced significantly annualized relapse rate (ARR) from 1.7 to 0.29 (p<10-4) and from 1,34 to 0,56 (p=0.0005) respectively, improving dramatically natural course of NMO.Phenotype and treatment of MS: Absence of Migration in MF in MS patients was found to be the strongest independent predictive factor of disability progression to DSS 6 (hazard ratio, 2.59; p=0.0002); beside short time to DSS3 (p=0.005), later age at onset (p=0.005), and multi-symptomatic onset (p=0.03). Treatment of MS by interferon beta-1 had a moderate impact in MS while natalizimab proved to be highly effective by reducing drastically ARR and inflammatory parameters on magnetic resonance imaging. Conclusion: Spectrum of demyelinating inflammatory disorders of CNS has reversed in French West Indies with overrepresentation of MS. Agressive therapy is needed to improve prognosis of NMO. Rapidly increasing of its incidence makes MS a new public health problem in French West Indies.

http://www.theses.fr/2012AGUY0511/document

Éditeur(s) : HAL CCSD Mineralogical Society of America
Résumé : International audience
In situ mineralization of CO2 in ultramafic rock-hosted aquifers is one of the promising solutions for decreasing CO2 concentrations in the atmosphere. Naturally altered ultramafic rocks suggest that carbonation processes are controlled by local heterogeneities in the structure of the rock and fluid transport at the water-rock interfaces. We studied the role of rock crystallographic anisotropy relative to the global fluid flow direction on the mineralization of CO2 by means of electron microscope analyses from the macro- to the micrometer scale (EBSD-FIB). The sample used for the measurements was a hot pressed olivine core percolated by water enriched in CO2 (pCO2 = 10 MPa) at 180 °C. During the percolation experiment, olivine was dissolved and two types of carbonates, dolomite, and magnesite, were precipitated on olivine surfaces. The results showed that the dissolution of olivine is controlled by its crystallographic properties as shown by the development of etch-pits only on the (010)ol planes and with elongated shapes parallel to the [010]ol axes. In contrast, the precipitation of carbonates is governed by hydrodynamic properties. Carbonates are heterogeneously distributed in the percolated rock. They are mainly located along the moderate (for dolomite) and the minor (for magnesite) flow paths, both oriented parallel to the principal fluid flow direction, which allow carbonates to be supplied with divalent cations (e.g., Ca2+, Mg2+, and Fe2+). In these flow paths, carbonate growth is systematically oriented normal to the flow that facilitates the development of chemical gradients with cationic supersaturation conditions for carbonate precipitation near the walls.In natural systems, the (010)ol planes are parallel to the Moho and the (100)ol planes are vertical; our study suggests that flow of CO2-rich fluids will induce precipitation of carbonates localized along, and preferentially clogging, vertical flow paths while favoring olivine dissolution along horizontal fluid pathways. This dual control of structure and fluid flow on carbonation mechanisms could be an important parameter allowing sustainable CO2 storage in peridotites, while limiting the risks of leakage toward the surface.
ISSN: 0003-004X

hal-01143393
https://hal.archives-ouvertes.fr/hal-01143393
DOI : 10.2138/am-2015-4913

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Satellite precipitation products are a means of estimating rainfall, particularly in areas that are sparsely equipped with rain gauges. The Guiana Shield is a region vulnerable to high water episodes. Flood risk is enhanced by the concentration of population living along the main rivers. A good understanding of the regional hydro-climatic regime, as well as an accurate estimation of precipitation is therefore of great importance. Unfortunately, there are very few rain gauges available in the region. The objective of the study is then to compare satellite rainfall estimation products in order to complement the information available in situ and to perform a regional analysis of four operational precipitation estimates, by partitioning the whole area under study into a homogeneous hydro-climatic region. In this study, four satellite products have been tested, TRMM TMPA (Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis) V7 (Version 7) and RT (real time), CMORPH (Climate Prediction Center (CPC) MORPHing technique) and PERSIANN (Precipitation Estimation from Remotely-Sensed Information using Artificial Neural Network), for daily rain gauge data. Product performance is evaluated at daily and monthly scales based on various intensities and hydro-climatic regimes from 1 January 2001 to 30 December 2012 and using quantitative statistical criteria (coefficient correlation, bias, relative bias and root mean square error) and quantitative error metrics (probability of detection for rainy days and for no-rain days and the false alarm ratio). Over the entire study period, all products underestimate precipitation. The results obtained in terms of the hydro-climate show that for areas with intense convective precipitation, TMPA V7 shows a better performance than other products, especially in the estimation of extreme precipitation events. In regions along the Amazon, the use of PERSIANN is better. Finally, in the driest areas, TMPA V7 and PERSIANN show the same performance.
ISSN: 2072-4292

Droits : http://hal.archives-ouvertes.fr/licences/copyright/
hal-01257912
https://hal.archives-ouvertes.fr/hal-01257912
https://hal.archives-ouvertes.fr/hal-01257912/document
https://hal.archives-ouvertes.fr/hal-01257912/file/remotesensing-07-15831.pdf
DOI : 10.3390/rs71215831