Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
This paper presents a synthesis of a multidisciplinary study carried out along the Nîmes Roman aqueduct, located in the southeast part of France. The study was motivated by archaeologists attempting to explain the partial destructions of only one aerial bridge of the aqueduct (Pont de la Lône). Given its close proximity to the Nîmes seismically active fault, a possible seismic origin for the destructions was invoked. Seismologists and structural engineers thus carried out a variety of field and numerical investigations to test the seismic hypothesis. Supporting field evidence was found first along the aerial bridge section of the aqueduct: broken stalactites, arch warping, cracks and destruction of the bridge just above a breast wall shortly after its construction. Secondly, the underground part of the canal was analysed: irregularity in the thickness of calcite deposits of the canal walls, presence of numerous cracks, horizontal shift of the otherwise linear structure of the canal and presence of calcite twins in the deposits, found only where the canal crosses the Nîmes fault system. Numerical modelling and experimental results show that (1) only the Pont de la Lône would have suffered serious damage under seismic solicitation (assuming an M6 earthquake at 10 km distance). The second aerial bridge, the three levels arches Pont du Gard, an historical monument still standing today, would have suffered less damage, due to its very different fundamental frequency of around 0.4 Hz, far from the amplified seismic near-field spectrum; (2) the numerical models also show that a fall of the canal wall would require a higher magnitude event (M > 6); (3) the presence of calcite twinning requires a differential static stress of 4 MPa or greater, which can only be achieved very close to the fault rupture of a M > 6 earthquake; (4) finally, local surface rupturing of such a fault would also corroborate the hypothesis that the observed offset of the canal may be partly seismically induced. Although other possible origins for each individual evidence may not be excluded, the observed spatiotemporal concentration of architectural/geological anomalies together with the numerical results allow us to support a possible co-seismic origin for these disorders, indirectly attesting to the potential seismic activity (M > 6) of the nearby Nîmes fault. Furthermore, following the conclusions of archaeological studies, the disorders occurred between 250 and 350 year AD, thus providing timing for this possible seismic event, an essential parameter in seismic hazard analysis. These results validate the archaeo-seismological approach as a tool that may help improve the knowledge of major infrequent earthquakes in areas of moderate seismic activity.
ISSN: 0921-030X

hal-00379064
https://hal.archives-ouvertes.fr/hal-00379064
DOI : 10.1007/s11069-008-9276-9

Éditeur(s) : HAL CCSD Institute of Electrical and Electronics Engineers (IEEE) Institute of Electrical and Electronics Engineers
Résumé : International audience
Conventional quantitative electron probe microanalysis of actinides requires the use of reference standard samples. However, for such elements, standards are generally not available. To overcome this difficulty, standardless methods of analysis are used, in which the x-ray intensity emitted by the standard is calculated. To be reliable, such calculations require accurate knowledge of physical data such as the x-ray production cross section. However, experimental data of this quantity are not always available for actinide elements. In the present work, experimental L and M x-ray production cross sections were measured for elements uranium and lead. Measurements were performed with two electron microprobes using wavelength-dispersive spectrometers using thin self-supporting targets. Experimental results are compared with calculated cross sections obtained from different analytical formulae, and, whenever possible, with experimental data obtained from the literature.
ISSN: 0018-9499

hal-01122820
https://hal.archives-ouvertes.fr/hal-01122820
DOI : 10.1109/TNS.2014.2321016

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 Oxford University Press (OUP)
Résumé : International audience
Our knowledge and understanding of the 3-D lithospheric structure of the Himalayas and the Tibetan Plateau is still challenging although numerous geophysical studies have been performed in the region. The GOCE satellite mission has the ambitious goal of mapping Earth's gravity field with unprecedented precision (i.e. an accuracy of 1-2 mGal for a spatial resolution of 100 km) to observe the lithosphere and upper-mantle structure. Consequently, it gives new insights in the lithospheric structure beneath the Himalayas and the Tibetan Plateau. Indeed, the GOCE gravity data now allow us to develop a new strategy for joint gravimetry-seismology inversion. Combined with teleseismic data over a large region in a joint inversion scheme, they will lead to lithospheric velocity-density models constrained in two complementary ways. We apply this joint inversion scheme to the Hi-CLIMB (Himalayan-Tibetan Continental Lithosphere during Mountain Building) seismological network which was deployed in South Tibet and the Himalayas for a 3-yr period. The large size of the network, the high quality of the seismological data and the new GOCE gravity data set allow us to image the entire lithosphere of this active area in an innovative way. We image 3-D low velocity and density structures in the middle crust that fit the location of discontinuous low S-velocity zones revealed by receiver functions in previous geophysical studies. In the deeper parts of our velocity model we image a positive anomaly interpreted to be the heterogenous Indian lithosphere vertically descending beneath the centre of the Tibetan Plateau.
ISSN: 0956-540X

hal-00858024
https://hal.archives-ouvertes.fr/hal-00858024
DOI : 10.1093/gji/ggs110

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : The tropical coast of Queensland, Australia is experiencing rapid population and tourism growth. Heavy development pressure is being placed on the biophysical environment, which includes the largest sand island in the world (World Heritage listed), Fraser Island. Despite the existence of State planning legislation oriented towards environmental sustainability, it is apparent that little, if any, regard is being paid to the long-term effects of resort and canal-estate development on the underlying biophysical environment of the coast and islands. While the remarkable surface features of the tropical coastal environment such as the surf beaches, the unique dune lakes, and the coastal vegetation, as well as the prolific wildlife, are used as selling points for new settlement and above all tourism, little is known or apparently of major concern with respect to the long term environmental impact of coastal development. While the crowding effect of large numbers of visitors and their impact on the natural environment - through significant degradation, site hardening or lack of proper on-site management – has been identified as a particular problem in certain areas, there is little knowledge of impacts on the underlying coastal geomorphology. In particular, developmental choices are often made in ignorance of, or disregard of, the widespread existence of tropical acid sulfate soils in that coastal environment. Reactive soils such as these can, and do, greatly affect the biophysical outcomes of a development if they are exposed. This paper documents such impacts in the form of a case study of the acid sulfate soil problem in relation to the development of tourist resorts, and suggests that part of the solution is for the State Government to insist on enforceable standards relating to their development for tourism in the coastal zone. These would reduce the use by many resort owners of fancy golf course developments as an environmental cover up to make it look as if they put a lot of effort into protecting the environment….
La côte tropicale du Queensland est confrontée à un accroissement rapide de la population. Les fortes pressions anthropiques pèsent sur le milieu biophysique, qui comprend notamment a plus grande île de sable du monde, un site classé Patrimoine de l’Humanité, Port Hinchinbrook et Fraser Island. Malgré l’existence d’une législation nationale orientée vers la préservation de l’environnement, il est manifeste que peu d’attention est accordée aux effets à long terme des sites touristiques et du développement de l’urbanisation sur ces franges côtières sensibles. L’aspect massif des flux de visiteurs et leurs impacts sur le milieu naturel a été identifié comme un sujet d’inquiétude particulier dans certaines régions. La connaissance des impacts sur la géomorphologie côtière souterraine est très réduite et les choix de développement sont souvent faits dans l’ignorance ou au mépris de la présence répandue de terrains de sulfate d’acide dans ce milieu côtier. Des sols réactifs comme ceux-là peuvent affecter, et affectent, grandement les résultats géophysiques d’un développement lorsqu’ils sont connus. Des études de cas sur le problème des sols de sulfate d’acide suggèrent qu’une partie de la solution pour le gouvernement de l’Etat du Queensland est d’imposer des normes obligatoires pour le développement du tourisme dans la zone côtière.
Australie
Queensland

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.1272
http://journals.openedition.org/etudescaribeennes/1272

Éditeur(s) : HAL CCSD ACM New York, NY, USA
Résumé : International audience
This paper focuses on the study of the behavior of a genetic algorithm based classifier system, the Adapted Pittsburgh Classifier System (A.P.C.S), on maze type environments containing aliasing squares. This type of environment is often used in reinforcement learning litterature to assess the performances of learning methods when facing problems containing non markov situations. Through this study, we discuss on the performances of the APCS on maze type environments and also of the efficiency of an improvement of the APCS learning method inspired from the XCS : the covering mechanism. We manage to show that, without any memory mechanism, the APCS is able to build and to keep accurate strategies to produce regular sub-optimal solutions to these maze problem. This statement is shown through a comparison of the results obtained by the XCS, XCSM and XCSMH on distinct maze problems with these obtained by the APCS.
Proceedings of the 2008 GECCO conference companion on Genetic and evolutionary computation
Atlanta, GA, United States

hal-00520607
https://hal.archives-ouvertes.fr/hal-00520607
DOI : 10.1145/1388969.1389013

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Strombus gigas and Strombus pugilis are threatened species and aquaculture represents a good alternative solution to the fishing. In this study, we highlighted the intracellular digestion process in the digestive gland of two Strombidae species, S. gigas and Strombus pugilis, by the cytochemical characterization of two lysosomal enzymes: acid phosphatase and arylsulfatase. In order to check the efficiency of artificial food digestion, we onducted the characterization on freshly collected, tarved and artificially fed individuals of S. pugilis. TEM observations of digestive gland sections from freshly collected individuals of both species revealed the resence of acid phosphatase and arylsulfatase activity mostly located in the apical third of digestive cells. Both enzymes were also detected in artificially fed individuals. In response to the starvation, acid phosphatase is not produced anymore by digestive cells, while arylsulfatase is still present. To our knowledge, this is the first cytochemical validation of intracellular digestion of artificial food in Strombidae. This study highlights the intracellular digestion of artificial food developed for Strombidae aquaculture. Moreover, we have shown that the lysosomal activity could be used as a feed index.
ISSN: 1059-910X

hal-00743013
https://hal.univ-antilles.fr/hal-00743013
DOI : 10.1002/jemt.22074

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cet article aborde la création du projet Observatoire de Tourisme et Culture de la Serra Gaúcha qui, dans son étape initiale, inclut les dix villes de l’Agglomération urbaine nord-est de l’État de Rio Grande Do Sul (AUNe). La création de l’Observatoire a été prévue dans le projet de Valorisation du Tourisme intégré à l’Identité culturelle des Territoires (VICTUR), financé par le Programme URB-AL, de la Commission européenne. Le programme de Maîtrise en Tourisme de l’Université de Caxias do Sul coordonne et développe les activités de recherche de l’Observatoire, dont l’objectif principal est de contribuer au développement régional, par un processus de socialisation de connaissances, au moyen d’un portail électronique (www.observatur.org.br). L’initiative démontre la possible coopération et la présence réelle d’échanges entre les organismes publics et privés pour la réalisation de projets d’intérêts communs qui mettent en valeur le capital social régional.
This article discusses the creation of Project Monitoring Tourism and Culture of the Serra Gaucha, which in its initial stage, includes the ten cities of the urban north-eastern state of Rio Grande Do Sul (ELL). The creation of the Observatory has been provided in the proposed Integrated Tourism Enhancement of the Cultural Identity Territories (victuri), funded by the URB-AL, the European Commission. The program in Tourism Degree from the University of Caxias do Sul coordinates and develops research activities of the Observatory, whose main objective is to contribute to regional development, um process of socialization of knowledge, by means of an electronic portal (www.observatur.org.br). The initiative demonstrates the cooperation and the possible presence of real exchange between public and private projects of common interests that enhance the regional capital.
Brésil
Rio Grande Do Sul

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.3986
http://journals.openedition.org/etudescaribeennes/3986

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Recently it has become clear that exposure to xenobiotics may result in various forms of cell death; not only passive cell deaths like necrosis, or programmed cell deaths such as apoptosis, but also regulated necrosis, autophagy, senescence, or mitotic catastrophe. Complex cell signaling networks influence the processing of cell death. Furthermore, recent research has revealed early complex molecular interactions between organelles prior to the final triggering of cell death. The plasma membrane may play an important role in the early cell death signaling events. Regarding this latter aspect, drugs and environmental pollutants have been reported to affect plasma membrane characteristics which may further affect cell fate. Changes in membrane fluidity or in composition and function of specialized membrane microdomains (plasma membrane remodeling) have been proven to be involved in the regulation of many important physiological signaling pathways, including cell death. Furthermore, it has been suggested that a crosstalk between chemical-induced cellular membrane effects and other organelles may be of vital importance to explain the final outcome of chemical exposure. Here, we review the effects of plasma membrane remodeling on cell survival and cell death; we describe how the cell signaling pathways activated by changes in plasma membrane characteristics may influence cell fate. Since plasma membrane function plays an important role in the regulation of a number of cellular responses, it has been implicated in the development or progress of several diseases. A better knowledge of the effects of various chemicals on plasma membrane remodeling may be important for understanding the pathogenesis of major diseases, and may assist in developing new therapeutic strategies.
ISSN: 0300-483X

inserm-00818916
http://www.hal.inserm.fr/inserm-00818916
DOI : 10.1016/j.tox.2012.12.014
PUBMED : 23287390

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
CMAS 3D, developed in MATLAB (R), is a program to support visualization of major element chemical data in three dimensions. Such projections are used to discuss correlations, metamorphic reactions and the chemical evolution of rocks, melts or minerals. It can also project data into 2D plots. The CMAS 3D interface makes it easy to use, and does not require any knowledge of Matlab (R) programming. CMAS 3D uses data compiled in a Microsoft Excel (TM) spreadsheet. Although useful for scientific research, the program is also a powerful tool for teaching.
ISSN: 0098-3004

hal-00413570
https://hal.archives-ouvertes.fr/hal-00413570
DOI : 10.1016/j.cageo.2008.07.002

Éditeur(s) : ESA Publication
Résumé : Satellite remote sensing has emerged as an essential and necessary observing system to acquire global information about the state of the ocean. Complemented with in situ observing networks, the ultimate goals are to be able to make accurate estimates of selected key sets of geophysical variables, with the intention of either making operational predictions across time and spatial boundaries, or advancing fundamental knowledge through development of empirical relationships and theoretical models. For satellite oceanography, improvements are then constantly being sought in our understandings of the geophysical processes, the sensor physics, the electromagnetic and microwave properties and interactions at the complex air-sea interface. Challenges appear as unlimited as the variety of sea surface dynamics and boundary layer meteorological conditions with their broad range of spatial and temporal scales across the globe. To face these challenges, numerous efforts took places over the passed decade to build an ever-increasing quality, quantity, duration and integration of ocean observations. In parallel, simulation capabilities largely improved. All these efforts are then all critically calling for improved methodologies to better structure the wealth of information that is made readily accessible. This latter aspect is a very demanding new component for future multidisciplinary scientific research. Major innovations to consolidate sensor data repositories, to automate tailored queries, to extract, reveal and quantify relationships will then closely associate computer science developments and applied statistics with comprehensive theoretical and experimental thematic studies.
Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society (ESA Publication), 2010

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00029/14046/11241.pdf
DOI:10.5270/OceanObs09.pp.12
http://archimer.ifremer.fr/doc/00029/14046/

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Millimetre waves correspond to the range of frequencies located between 30 and 300 GHz. Many applications exist and are emerging in this band, including wireless telecommunications, imaging and monitoring systems. In addition, some of these frequencies are used in therapy in Eastern Europe, suggesting that interactions with the human body are possible. This review aims to summarise current knowledge on interactions between millimetre waves and living matter. Several representative examples from the scientific literature are presented. Then, possible mechanisms of interactions between millimetre waves and biological systems are discussed.
ISSN: 1631-0705

hal-00874362
https://hal.archives-ouvertes.fr/hal-00874362
DOI : 10.1016/j.crhy.2013.02.005

Éditeur(s) : HAL CCSD Wiley
Résumé : Tank bromeliads form a conspicuous, yet neglected freshwater habitat in Neotropical forests. Recent studies driven by interests in medical entomology, fundamental aspects of bromeliad ecology and experimental research on food webs have, however, prompted increasing interest in bromeliad aquatic ecosystems. As yet, there is nothing in the literature about the life histories and environmental drivers of invertebrate population dynamics in tank bromeliads. Based on fortnightly samples taken over oneyear, size frequency plots and individual dry masses allowed us to establish the life cycles and growth rates of the dominant aquatic invertebrates in a common bromeliad species of French Guiana. Linear mixed-effect models and Mantel tests were used to predict changes in density, biomass, and growth rates in relation to temperature, rainfall, humidity and detrital resources. Annual variations in invertebrate densities and biomasses could be described according to three types of distribution: unimodal, bimodal or almost constant. Despite seasonal variations, precipitation, temperature, relative humidity and detritus concentration accounted significantly for changes in density and biomass, but we found no significant responses in growth rates of most invertebrate species. Species rather displayed non-seasonal life cycles with overlapping cohorts throughout the year. There was also a trend for delayed abundance peaks among congeneric species sharing similar functional traits, suggesting temporal partitioning of available resources. Beyond novel knowledge, quantitative information on life histories is important to predict food-web dynamics under the influence of external forcing and self-organisation. Our results suggest that changes in species distribution that will affect population dynamics through biotic interactions in space and/or time could have greater effects on food webs and ecosystem functioning than changes in environmental factors per se.
ISSN: 0046-5070

hal-01607779
https://hal.archives-ouvertes.fr/hal-01607779
DOI : 10.1111/fwb.12862
PRODINRA : 407311

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
We use 3 yr of surface absolute gravity measurements at three sites on the Larzac plateau (France) to quantify the changes induced by topography and the building on gravity time-series, with respect to an idealized infinite slab approximation. Indeed, local topography and buildings housing ground-based gravity measurement have an effect on the distribution of water storage changes, therefore affecting the associated gravity signal. We first calculate the effects of surrounding topography and building dimensions on the gravity attraction for a uniform layer of water. We show that a gravimetric interpretation of water storage change using an infinite slab, the so-called Bouguer approximation, is generally not suitable. We propose to split the time varying gravity signal in two parts (1) a surface component including topographic and building effects (2) a deep component associated to underground water transfer. A reservoir modelling scheme is herein presented to remove the local site effects and to invert for the effective hydrological properties of the unsaturated zone. We show that effective time constants associated to water transfer vary greatly from site to site. We propose that our modelling scheme can be used to correct for the local site effects on gravity at any site presenting a departure from a flat topography. Depending on sites, the corrected signal can exceed measured values by 5-15 μGal, corresponding to 120-380 mm of water using the Bouguer slab formula. Our approach only requires the knowledge of daily precipitation corrected for evapotranspiration. Therefore, it can be a useful tool to correct any kind of gravimetric time-series data.
ISSN: 0956-540X

hal-00795590
https://hal.archives-ouvertes.fr/hal-00795590
DOI : 10.1093/gji/ggs007

Éditeur(s) : Academic Press Ltd- Elsevier Science Ltd
Résumé : Over the last decade, RNA interference pathways have emerged in eukaryotes as critical regulators of many diverse biological functions including, among others, transcriptional gene regulation, post-transcriptional gene silencing, heterochromatin remodelling, suppression of transposon activity, and antiviral defences. Although this gene silencing process has been reported to be relatively well conserved in species of different phyla, there are important discrepancies between plants, invertebrates and mammals. In penaeid shrimp, the existence of an intact and functional RNAi machinery is supported by a rapidly growing body of evidence. However, the extent to which this process participates to the host immune responses remains poorly defined in this non-model organism. This review summarizes our current knowledge of RNAi mechanisms in shrimp and focuses on their implication in antiviral activities and shrimp immune defences.
Fish & Shellfish Immunology (1050-4648) (Academic Press Ltd- Elsevier Science Ltd), 2013-04 , Vol. 34 , N. 4 , P. 1002-1010

Droits : 2012 Elsevier Ltd. Published by Elsevier Ltd
http://archimer.ifremer.fr/doc/00119/23063/20899.pdf
DOI:10.1016/j.fsi.2012.06.008
http://archimer.ifremer.fr/doc/00119/23063/

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
The spatio‐temporal dynamics of disease spread provide an area of acute scientific interest but substantial analytic challenges. Analytic approaches need to draw from current knowledge of disease systems yet be flexible enough to provide targeted inference without restrictive assumptions. We explore this balance in detail with respect to the observed pattern of spread of sugarcane yellow leaf virus, the causal agent of yellow leaf disease. This disease affects cultivated sugarcane plants and spreads via an aphid vector (Melanaphis sacchari). The system is of considerable economic interest, but presents several analytic complications. First, the plants begin as well separated individuals that grow into large plants with overlapping leaf canopies enabling increased vector access between neighbouring plants. The overlap between neighbouring plants first occurs within rows and then extends between rows, presenting another interesting spatial component to consider when modelling the propagation of infection. Second, the vector initially flies between plants but at some point sheds wings and shifts to walking between plants. We are particularly interested in how these two features of the system and their interrelation may impact the spatial spread of disease over time. In addition, we also explore the impact of potential immigration of infected vectors from outside of the study area. We treat our observed cane field as a spatial grid with regular spacing between rows and smaller spacing within rows. Our data consist of observed disease status of each of 1643 plants at each of six time points. We provide descriptive summaries of the temporal evolution of spatial pattern in infection, then propose hierarchical models to describe the pattern and capture the influence of the ecological and environmental factors listed above.
ISSN: 0143-9782

hal-00684235
https://hal.archives-ouvertes.fr/hal-00684235

Éditeur(s) : HAL CCSD
Résumé : After a review of knowledge, attitudes and practices related to leishmaniasis in Amazonia, this work focused on the vegetal species used for its cure. Utilization of geographic and cultural diffusion index allowed to characterize Pan-Amazonian antileishmanial taxa and to investigate the mechanisms allowing for their diffusion. Consistency between traditional use and laboratory results were looked for. Two " knowledge, attitudes and practices " surveys were conducted amongst the Chayahuita (Peru) and along the upper and middle Oyapock river (French Guiana, Teko and Wayãpi groups). These allowed us to refine the knowledge and perception of the disease in these cultural groups, to define patterns in the therapeutic itinerary, and to make an inventory of antileishmanial plant species. Thirty one species used by the Chayahuita were collected and submitted to in vitro assays on axenic amastigotes of Leishmania amazonensis. Pseudoelephantopus spicatus (Asteraceae) is one of the most active and most frequently used plant. From this species, piptocarphol derivatives, very active against Leishmania in vitro, were isolated along with ursolic acid. Presence of these molecules justifies the use of this species as traditional antileishmanial remedy by the Chayahuita.
Après avoir dressé un inventaire des connaissances, attitudes et pratiques concernant les leishmanioses en Amazonie d'après la littérature, le présent travail s'est focalisé sur les espèces végétales connues et utilisées dans le traitement de ces maladies. L'utilisation d'indices de diffusion (géographique, culturelle) a permis de caractériser des taxons antileishmaniens panamazoniens et de définir certains mécanismes impliqués dans leur diffusion. Des cohérences entre usages traditionnels et résultats de laboratoire ont été recherchés. Deux enquêtes de type " connaissance, attitudes et pratiques " effectuées au sein du groupe chayahuita (Pérou), et sur le haut et moyen cours du fleuve Oyapock (Guyane, communautés teko et wayãpi) ont permis d'affiner les connaissances sur la perception de cette maladie dans ces différents groupes culturels, de comprendre les recours aux différentes thérapeutiques et de dresser un inventaire des espèces médicinales utilisées. Trente et une espèces collectées chez les Chayahuita ont été soumises à des essais in vitro sur amastigotes axéniques de Leishmania amazonensis. Pseudoelephantopus spicatus (Asteraceae) compte parmi les espèces les plus actives et les plus fréquemment utilisées, et des dérivés du piptocarphol très actifs sur les parasites in vitro ont été isolés conjointement à l'acide ursolique. La présence de ces molécules permet de justifier en partie l'usage de cette espèce comme antileishmanien traditionnel par les Chayahuita.
https://tel.archives-ouvertes.fr/tel-00590977

tel-00590977
https://tel.archives-ouvertes.fr/tel-00590977
https://tel.archives-ouvertes.fr/tel-00590977/document
https://tel.archives-ouvertes.fr/tel-00590977/file/ThA_se_Odonne_light.pdf

Éditeur(s) : HAL CCSD
Résumé : The purpose of this thesis is to improve the knowledge about and apply data mining techniques and some Bayesian model in the field of social and environmental health inequalities. On the neighborhood scale on the Paris, Marseille, Lyon and Lille metropolitan areas, the health event studied is infant mortality. We try to explain its risk with socio-economic data retrieved from the national census and environmental exposures such as air pollution, noise, proximity to traffic, green spaces and industries. The thesis is composed of two parts. The data mining part details the development of a procedure of creation of multidimensional socio-economic indices and of an R package that implements it, followed by the creation of a cumulative exposure index. In this part, data mining techniques are used to synthesize information and provide composite indicators amenable for direct usage by stakeholders or in the framework of epidemiological studies. The second part is about Bayesian models. It explains the "BYM" model. This model allows to take into account the spatial dimension of the data when estimating mortality risks. In both cases, the methods are exposed and several results of their usage in the above-mentioned context are presented. We also show the value of the socio-economic index procedure, as well as the existence of social inequalities of infant mortality in the studied metropolitan areas.
Cette thèse a pour but d'améliorer les connaissances concernant les techniques d'analyse de données et certains modèles bayésiens dans le domaine de l'étude des inégalités sociales et environnementales de santé. À l'échelle géographique de l'IRIS sur les agglomérations de Paris, Marseille, Lyon et Lille, l'événement sanitaire étudié est la mortalité infantile dont on cherchera à expliquer le risque avec des données socio-économiques issues du recensement et des expositions environnementales comme la pollution de l'air, les niveaux de bruit et la proximité aux industries polluantes, au trafic automobile ou aux espaces verts. Deux volets principaux composent cette thèse. Le volet analyse de données détaille la mise au point d'une procédure de création d'indices socio-économiques multidimensionnels et la conception d'un package R l'implémentant, puis la création d'un indice de multi-expositions environnementales. Pour cela, on utilise des techniques d'analyse de données pour synthétiser l'information et fournir des indicateurs composites utilisables directement par les décideurs publics ou dans le cadre d'études épidémiologiques. Le second volet concerne les modèles bayésiens et explique le modèle " BYM ". Celui-ci permet de prendre en compte les aspects spatiaux des données et est mis en œuvre pour estimer le risque de mortalité infantile. Dans les deux cas, les méthodes sont présentées et différents résultats de leur utilisation dans le contexte ci-dessus exposés. On montre notamment l'intérêt de la procédure de création d'indices socio-économiques et de multi-expositions, ainsi que l'existence d'inégalités sociales de mortalité infantile dans les agglomérations étudiées.
https://tel.archives-ouvertes.fr/tel-00943004

tel-00943004
https://tel.archives-ouvertes.fr/tel-00943004
https://tel.archives-ouvertes.fr/tel-00943004/document
https://tel.archives-ouvertes.fr/tel-00943004/file/Manuscrit_LallouA_final.pdf

Éditeur(s) : HAL CCSD Geological Society of America
Résumé : International audience
Fault pseudotachylytes form by frictional melting during seismic slip and therefore are widely interpreted as “earthquake fossils.” Rapid movement along a rupture surface typically forms a pseudotachylyte generation vein, the thickness of which increases with earthquake magnitude. The direction and sense of seismic slip cannot always be determined due to the generally complex geometry of pseudotachylyte veins. Here we show, for the first time, that the orientation of the magnetic fabric of fault pseudotachylytes indicates both direction and sense of seismic slip. The magnetic fabric, acquired in a manner similar to that of other magmas, arises in this case from the asymmetric preferred orientation of paramagnetic grains during viscous shear of the friction melt. This kinematic information, coupled with fault plane orientation and generation vein thickness, provides new and critical insight for the earthquake focal mechanism. The magnetic fabric of pseudotachylytes therefore not only constitutes a valuable kinematic criterion for these fault rocks, but also could expand our knowledge of prehistoric seismic events.
ISSN: 0091-7613

hal-01217133
https://hal.archives-ouvertes.fr/hal-01217133
DOI : 10.1130/G36587.1

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
While the populations of large herbivores are being depleted in many tropical rainforests, the importance of their trophic role in the ecological functioning and biodiversity of these ecosystems is still not well evaluated. This is due to the outstanding plant diversity that they feed upon and the inherent difficulties involved in observing their elusive behaviour. Classically, the diet of elusive tropical herbivores is studied through the observation of browsing signs and macroscopic analysis of faeces or stomach contents. In this study, we illustrate that the original coupling of classic methods with genetic and ethnobotanical approaches yields information both about the diet diversity, the foraging modalities and the potential impact on vegetation of the largest terrestrial mammal of Amazonia, the lowland tapir. The study was conducted in the Guianan shield, where the ecology of tapirs has been less investigated. We identified 92 new species, 51 new genera and 13 new families of plants eaten by tapirs. We discuss the relative contribution of our different approaches, notably the contribution of genetic barcoding, used for the first time to investigate the diet of a large tropical mammal, and how local traditional ecological knowledge is accredited and valuable for research on the ecology of elusive animals.
ISSN: 1932-6203

halsde-00676374
https://hal.archives-ouvertes.fr/halsde-00676374
DOI : 10.1371/journal.pone.0025850
PUBMED : 21991372