Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triato-mines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance , diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Cha-gas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.
ISSN: 1935-2727

Droits : http://creativecommons.org/licenses/by/
hal-01298091
https://hal-univ-perp.archives-ouvertes.fr/hal-01298091
https://hal-univ-perp.archives-ouvertes.fr/hal-01298091/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01298091/file/journal.pntd.0004427.PDF
DOI : 10.1371/journal.pntd.0004427

Éditeur(s) : HAL CCSD
Résumé : International audience
EGU General Assembly 2015
Vienne, Austria

hal-01286324
https://hal.archives-ouvertes.fr/hal-01286324
BIBCODE : 2015EGUGA..1713337U

Éditeur(s) : HAL CCSD Universidad de Malaga
Résumé : International audience
The development of information systems follows a long and complex process in which various actors are involved. We report an experiment in which we observe the evolution of the analysis model of an information system through 15 successive versions. We use indicators on the underlying concept lattices built by applying Relational Concept Analysis (RCA) to each version. RCA is an extension of FCA which groups entities based on characteristics they share, including links to other entities. It here helps in analyzing their evolution. From this experience, we establish recommendations to monitor and verify the proper evolution of the analysis process.
CLA'2012: 9th International Conference on Concept Lattices and Applications
Fuengirola (Málaga), Spain

ISBN : 978-84-695-5252-0
lirmm-00743886
http://hal-lirmm.ccsd.cnrs.fr/lirmm-00743886
http://hal-lirmm.ccsd.cnrs.fr/lirmm-00743886/document

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Grey (Halichoerus grypus) and harbour seals (Phoca vitulina) are sympatric seal species, but they display distinct strategies of habitat use and connectivity between haulout sites. The distribution patterns and variations in relative abundance of both species were investigated along the French coast of the English Channel, at the southern limit of their range where seal numbers are increasing. Regular censuses conducted at all main haulout sites in mainland France showed significant seasonal variations at most sites, with more harbour seals counted during summer (breeding and moulting seasons), and more grey seals during summer only in the eastern English Channel. Trends in maximum haulout numbers at haulout sites showed a significant increase over the last five years, ranging from 9.7 to 30.9% per year for harbour seals, and from 5.8% (in the western English Channel) to 49.2% (in the eastern English Channel) per year for grey seals. These rates of increase in grey seal numbers are not linked to local pup production and most probably result from seal movements from the southwest British Isles and the North Sea, respectively. Aerial surveys conducted across the English Channel showed that most seal observations at sea were concentrated in the north-eastern English Channel. Telemetry showed that the 28 harbour seals tracked remained highly coastal, within a radius of 100 km from their haulout sites, and did not move to other known colonies. Grey seals moved much greater distances, reaching up to 1200 km from their capture site. More than half of the 45 grey seals tracked crossed the English Channel, especially during the breeding season, moving to known colonies in the southwest British Isles and the North Sea. Combining individual tracks and long-term surveys of the seal populations allowed a better understanding of the dynamics of these populations and their connectivity at a larger regional scale. The findings provide direct information for the management of grey and harbour seals within the frame of the Marine Strategy Framework Directive, and highlight focus areas where potential interactions between the two species should be monitored.
ISSN: 0967-0645

hal-01509674
https://hal.archives-ouvertes.fr/hal-01509674
DOI : 10.1016/j.dsr2.2017.04.004

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Factors controlling ocean acidification and its temporal variations were studied over the 1995–2011 period at the Dyfamed site at 10 m depth, in the North Mediterranean Sea. The results indicated a mean annual decrease of 0.003 ± 0.001 pH units on the seawater scale. The seasonal variability was characterized by a pH decrease during springtime and a strong pH increase in late fall. Anthropogenic CO2 (CANT) absorption by the ocean was the key driver of seawater acidification in this region, accounting for about 70% of the observed drop in pH, followed by water temperature (about 30%). The total inorganic carbon (CT) data showed a CT increase of 30.0 ± 1.0 μmol kg−1 per decade. This decadal increase is mainly due to the CANT penetration (43.2 μmol kg−1 per decade) in surface waters, which is mitigated for by relatively small opposing changes in CT due to physical and biological processes.
ISSN: 0141-1136

hal-01286093
https://hal-univ-perp.archives-ouvertes.fr/hal-01286093
DOI : 10.1016/j.marenvres.2016.02.016

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon. We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections. The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3°C, mean incidence rates during epidemics could double. In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model dengue spatial heterogeneity in other countries.
ISSN: 1935-2727

Droits : http://creativecommons.org/licenses/by/
pasteur-01247037
https://hal-riip.archives-ouvertes.fr/pasteur-01247037
https://hal-riip.archives-ouvertes.fr/pasteur-01247037/document
https://hal-riip.archives-ouvertes.fr/pasteur-01247037/file/journal.pntd.0004211.pdf
DOI : 10.1371/journal.pntd.0004211

Éditeur(s) : HAL CCSD SAGE Publications
Résumé : International audience
This work aims at developing a general methodology to determine the spatial changes in the basic reproduction number for vector-borne diseases. This requires a spatially explicit modeling system which will be based on a cellular automata (CA) approach and applied to the Chagas disease for both homogeneous and heterogeneous landscapes. Using an extension of the so-called next-generation matrix, we obtained an expression for the basic reproduction number Formula that characterizes the spatial heterogeneity of the risk of emergence of an outbreak. The performed simulation with the built CA model shows the effect of local vector dispersal in a heterogeneous landscape for Chagas disease transmission.
ISSN: 0037-5497

hal-01271476
https://hal-univ-perp.archives-ouvertes.fr/hal-01271476
DOI : 10.1177/0037549715626520

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Heterogeneous patterns of malaria transmission are thought to be driven by factors including host genetics, distance to mosquito breeding sites, housing construction, and socio-behavioural characteristics. Evaluation of local transmission epidemiology to characterize malaria risk is essential for planning malaria control and elimination programmes. The use of geographical information systems (GIS) techniques has been a major asset to this approach. To assess time and space distribution of malaria disease in Bandiagara, Mali, within a transmission season, data were used from an ongoing malaria incidence study that enrolled 300 participants aged under six years old ". Methods: Children's households were georeferenced using a handheld global position system. Clinical malaria was defined as a positive blood slide for Plasmodium falciparum asexual stages associated with at least one of the following signs: headache, body aches, fever, chills and weakness. Daily rainfall was measured at the local weather station. Landscape features of Bandiagara were obtained from satellite images and field survey. QGIS™ software was used to map malaria cases, affected and non-affected children, and the number of malaria episodes per child in each block of Bandiagara. Clusters of high or low risk were identified under SaTScan W software according to a Bernoulli model. Results: From June 2009 to May 2010, 296 clinical malaria cases were recorded. Though clearly temporally related to the rains, Plasmodium falciparum occurrence persisted late in the dry season. Two " hot spots " of malaria transmission also found, notably along the Yamé River, characterized by higher than expected numbers of malaria cases, and high numbers of clinical episodes per child. Conversely, the northeastern sector of the town had fewer cases despite its proximity to a large body of standing water which was mosquito habitat. Conclusion: These results confirm the existence of a marked spatial heterogeneity of malaria transmission in Bandiagara, providing support for implementation of targeted interventions. Background Malaria is one of the leading causes of morbidity and mortality in the world, with an estimated 3.3 billion people at risk of malaria [1]. The incidence of malaria worldwide is estimated to be 216 million cases per year, with 81% of these cases occurring in sub-Saharan Africa. Malaria kills approximately 655,000 people per year; 91% of deaths occur in sub-Saharan Africa [1], mostly in children under five years of age. In Mali, West Africa, malaria represents 36.5% of consultation motives in health center, it is a leading cause of morbidity and mortality children of less than five years of age and the first reason of anaemia in pregnant women [2]. Malaria transmission is seasonal. Malaria parasite transmission and clinical disease are characterized by important microgeographic variation, often between adjacent villages, households or families [3-8]. This local heterogeneity is driven by a variety of factors including human genetics [9,10], distance to potential breeding sites [11,12], housing construction
ISSN: 1475-2875

hal-01307672
https://hal-amu.archives-ouvertes.fr/hal-01307672
https://hal-amu.archives-ouvertes.fr/hal-01307672/document
https://hal-amu.archives-ouvertes.fr/hal-01307672/file/1475-2875-12-82.pdf
DOI : 10.1186/1476-072X-2-5

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The implication of oxidative stress as primary mechanism inducing doxorubicin (DOX) cardiotoxicity is still questionable as many in vitro studies implied supra-clinical drug doses or unreliable methodologies for reactive oxygen species (ROS) detection. The aim of this study was to clarify whether oxidative stress is involved in compliance with the conditions of clinical use of DOX, and using reliable tools for ROS detection. We examined the cytotoxic mechanisms of 2 μM DOX 1 day after the beginning of the treatment in differentiated H9c2 rat embryonic cardiac cells. Cells were exposed for 2 or 24 h with DOX to mimic a single chronic dosage or to favor accumulation, respectively. We found that apoptosis was prevalent in cells exposed for a short period with DOX: cells showed typical hallmarks as loss of anchorage ability, mitochondrial hyperpolarization followed by the collapse of mitochondrial activity, and nuclear condensation. Increasing the exposure period favored a shift to necrosis as the cells preferentially exhibited early DNA impairment and nuclear swelling. In either case, measuring the fluorescence lifetime of 1-pyrenebutyric acid or the intensities of dihydroethidium or amplex red showed a consistent pattern in ROS production which was a slight increased level far from representative of an oxidative stress. Moreover, pre-treatment with dexrazoxane provided a cytoprotective effect although it failed to detoxify ROS. Our data support that oxidative stress is unlikely to be the primary mechanism of DOX cardiac toxicity in vitro.
ISSN: 0300-8177

hal-01285736
https://hal-univ-perp.archives-ouvertes.fr/hal-01285736
DOI : 10.1007/s11010-016-2653-x

Éditeur(s) : HAL CCSD
Résumé : International audience
The most active deep convection area in the western Mediterranean Sea is located in the Gulf of Lions. Recent studies in this area provides some insights on the complexity of the physical dynamics of convective regions, but very little is known about their impacts on the biogeochemical properties. The CASCADE (CAscading, Surge, Convection, Advection and Downwelling Events) cruise, planed in winter 2011, give us the opportunity to compare vertical profiles of properties sampled either during stratified conditions or after/during a convection event. In the present study, we focus on the distributions of the carbonate system properties (mainly total alkalinity, AT; and total dissolved inorganic carbon, CT) because, in the context of the climate change, deep convection areas are suspected to significantly increase the sequestration of anthropogenic CO2 (CANT). Given its limited size, the impact of the Mediterranean Sea on the global carbon budget is probably minor but this marginal sea can be used as a laboratory to better understand carbon sequestration and its transfer to the basin interior by deep convection processes. Distributions of AT and CT, both measured from bottle samples, and that of CANT (estimated with the TrOCA approach) are first analyzed in the light of other key properties (salinity, temperature, and dissolved oxygen). An objective interpolation procedure is then applied to estimate CT and AT from CTD measured properties. With this procedure, the vertical resolution goes from a maximum of 32 samples per station to one property estimate every meter (more detailed distributions are obtained). Results provide arguments to conclude that CANT is rapidly transferred to the deepest layer due to deep convection events. During deep convection events, the increase of CANT in the water column is positively correlated to that of potential density and oxygen content. The challenge of quantifying the amount of sequestered carbon is however not resolved due to the complexity and the highly dynamical nature of the convective regions. Deep convection in the Gulf of Lions, in parallel with cascading along the continental slope, could thus potentially explain the very high levels of both CANT and acidification estimated in the deep layers of the western Mediterranean Sea.
Deep Sea Research Part I: Oceanographic Research Papers

hal-01336725
https://hal-univ-perp.archives-ouvertes.fr/hal-01336725
DOI : 10.1016/j.dsr.2016.04.003

Éditeur(s) : HAL CCSD
Résumé : Integrating ecological connectivity into marine ecosystem management and planning is important, especially in a global context of severe fish stocks depletion and growing habitat degradation. Environmental tools such as Marine Protected Areas have been proposed to protect biodiversity, restore damaged ecosystems, sustain fisheries, and rebuild overexploited stocks. The effectiveness of marine protected areas depends in part on the maintenance of connectivity between marine populations, linked by ecological processes such as larval dispersal. In this thesis, we applied a biophysical model driven by ocean currents derived from satellite altimetry to evaluate connectivity between Western Indian Ocean reefs and across the current MPA system in the Mediterranean Sea. We applied different methods of analysis such as graph-theoretic and clustering. In the Western Indian Ocean, marine connectivity analyses show that the number of connections between reefs increases with fish pelagic larval duration. It also highlights a low connectivity across the region and a high interconnectivity within several regions (Mozambique Channel, Mascarene archipelago). In the Mediterranean Sea, connectance is globally low at the regional scale. This connectance is more important in Western than Eastern Mediterranean. Moreover, the marine connectivity analyses revealed high domestic connectivity rates. Depending on the study area, priority reefs or sites for MPA implementation are proposed. Finally, implications for transboundary marine policies and regional cooperation are discussed.
Intégrer les connaissances sur la connectivité écologique dans la gestion des écosystèmes marins est essentiel, surtout dans un contexte d'appauvrissement des ressources marines et de dégradation des habitats côtiers à l'échelle mondiale. Des outils environnementaux, tels que les Aires Marines Protégées ont été mises en œuvre pour protéger la biodiversité, restaurer les écosystèmes endommagés, soutenir les pêcheries et reconstituer les stocks surexploités. Leur efficacité dépend en partie du maintien de la connectivité entre les populations marines, assurée à travers divers processus écologiques dont la dispersion larvaire. Dans le cadre de ce travail de thèse, un modèle biophysique intégrant des données de courants, issues de mesures d'altimétrie par satellite, a été utilisé pour évaluer la connectivité entre les récifs de l'océan Indien d'une part, et à travers le réseau d'AMP de Méditerranée d'autre part. Différentes méthodes d'analyse ont été utilisées, telles que la théorie des graphes et le clustering. Dans l'océan Indien occidental, l'analyse des connectivités marines montre que le nombre de connexions entre les récifs augmente avec la durée de vie larvaire des poissons. Elle met également en évidence une faible connectivité à l'échelle de la région, mais une forte inter-connectivité au sein de plusieurs sous-régions (Canal du Mozambique, Mascareignes). En Méditerranée, la connectance est globalement faible à l'échelle régionale, bien que plus importante dans le bassin occidental que le bassin oriental. L'analyse des connectivités marines montre également un taux de connectivité élevé à l'échelle d'un même pays. Selon le cas d'étude, une liste de récifs ou de sites prioritaires dans la mise en œuvre des AMP a été proposée. Enfin, les implications de ces résultats en termes de politiques transfrontalières et de coopération régionale sont discutées.
https://tel.archives-ouvertes.fr/tel-01269631

NNT : 2015LARE0003
tel-01269631
https://tel.archives-ouvertes.fr/tel-01269631
https://tel.archives-ouvertes.fr/tel-01269631/document
https://tel.archives-ouvertes.fr/tel-01269631/file/2015lare0003_ECrochelet.pdf

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In this work, we have studied quenching of the fluorescence of two well-known oxygen probes, 1-pyrene butyric acid (PBA) and tris(2,2'-bipyridine)ruthenium ([Ru(bpy)(3)](2+)) by reactive oxygen species (superoxide anion, nitric oxide derivative, hydrogen peroxide) and by the O(2) molecule. Both, time-resolved and steady state fluorescence measurements were performed in solution (ethanol, dimethyl sufoxide, water) and in micelles of Sodium Dodecyl Sulfate that serve as a model for membrane-containing biological structures. We have found that only the free radicals and O(2) can actively quench for the two probes, but not the diamagnetic H(2)O(2). Our data correspond to the classical Stern-Volmer equation. H(2)O(2) has an effect only at high molar concentrations (>0.1 M). In contrast, effective concentrations of free radicals and O(2) that lead to quenching are in millimolar range. In conclusion, our methods allows for detecting global ROS that are small free radicals without interference from the reactive hydroxyl radical. Our data suggest that the method can be used for the quantification of ROS in individual living cells based on the measurement of fluorescence lifetime of those probes
ISSN: 1053-0509

hal-01326234
https://hal.archives-ouvertes.fr/hal-01326234
DOI : 10.1007/s10895-008-0425-z

Éditeur(s) : HAL CCSD
Résumé : International audience
Sharks International
Durban, South Africa

hal-01487162
http://hal.univ-reunion.fr/hal-01487162

Éditeur(s) : HAL CCSD
Résumé : International audience
The published literature related to distributed parameter systems theory is quite large, and it is not feasible in a single book to give a detailed review on the wide historical development of all of it. Our choice of what to cover was motivated by the following consideration. Since distributed parameter systems evolve in time and space, the research investigations on their analysis and control focus on considering the whole system domain for any study. We feel strongly that within this research field, animportant consideration was missing; that of considering that the system may give raise to prescribed subdomains (regions) where one has to achieve an objective. This is the case of so many applications ranging from engineering to life sciences. For that reason, covering classical prerequisite in analysis and control areas, we have devoted the book to the extension of the classical distributed parameter results to regional ones.Students of mathematics do not come into contacts with distributed parameter systems during their classes. They are introduced to them when they start research and often they are influenced by the knowledge and the advice of experimented scientists. This was our case at the very beginning of these research investigations in the mid 70’s. We would liketo express our special thanks to many of them and mainly late Professor Anthony J. Pritchard (University of Warwick, GB) and late Professor J.L. Lions (College de France) who were so encouraging in front of our determination in driving an academic carrier. We also express our thanks to our co-workers and research students. We wish to acknowledge the feedback from all those who took courses based on various parts of this book.This book may be used by graduate students in mathematics, engineering, physics, and even by students from other fields such as life or environmental sciences. This book may also be used as an information source for researchers and education professionals. We assume that the readers already know the basic concepts of analysis and control of distributedparameter systems.
https://hal.archives-ouvertes.fr/hal-01297188

ISBN : 978-2-35412-140-2
hal-01297188
https://hal.archives-ouvertes.fr/hal-01297188

Éditeur(s) : HAL CCSD
Résumé : French Guiana is a region located on the Guiana Shield in South America. Is presents at the same time a high originality in biodiversity, a good state of conservation and a strong correlation to Amazonian carbon stocks. Knowledge on evolution of the forest structure of French Guiana is however still insufficient to bring an optimal management at territory scale. Availability as never seen before of remote sensing data at high spatial resolution such as LiDAR, on large coverage, offers the opportunity to assess the forest resource in French Guiana. The work done during this thesis aim mostly to study the structure and the variations of the canopy height, the factors determining its variability and the consequences of forest logging activities. The data used during this thesis come from an airborne LiDAR and field data from Office National des Forêts (ONF). This thesis manuscript is divided in three parts. The first part introduces the problem and sets the objectives of the thesis. The second part takes the so-called "article" form, that is, the different chapters that compose it are scientific articles published or in the course of publication, it is composed of three studies (I) A study on the gaps detection and environmental determinants on the gap sizes distribution in natural forest: How to characterize the gap size distribution and are there environmental determinants that influence the statistical distribution of gap size? This article has been submitted in Biogeoscience. (ii) A study of the control of the environment on the canopy height structure and variations at different spatial resolutions. Which spatial scales are relevant for analyzing the environmental determinants of canopy height changes in tropical forests from remote sensing data? How can the environment help or not map the height of the canopy in the rainforest? This article was accepted for publication in Remote Sensing. (iii) a third study where we quantified the effects of Reduced Impact Logging (RIL) on the structure and variation of canopy height. What are the effects of logging on canopy height variations and gap size distribution? This article will be submitted for publication in a Forest Ecology and Management journal. In the last part, after a synthesis of the main results, we propose a conclusion.
La Guyane française est une région située sur le Plateau des Guyanes en Amérique du sud. Elle présente à la fois une grande originalité en termes de biodiversité, un bon état de conservation et une forte contribution au stock de carbone Amazonien. Les connaissances sur l’évolution de la structure forestière de la Guyane française restent cependant insuffisantes pour offrir une gestion optimale à l’échelle du territoire. La disponibilité sans précédent de données de télédétection à très haute résolution spatiale telles que le LiDAR , sur de larges couvertures nous offre l'opportunité d’évaluer la ressource forestière de la Guyane Française. Les travaux réalisés dans le cadre de cette thèse visent prioritairement à étudier la structure et les variations de la hauteur de canopée, les facteurs déterminant sa variabilité ainsi que les conséquences des activités d’exploitation forestière. Les données utilisées au cours de la thèse proviennent d’un LiDAR aéroporté et des données de terrains de l'Office National des Forêts (ONF). Ce manuscrit de thèse est divisé en trois grandes parties. La première partie introduit la problématique et fixe les objectifs de la thèse. La seconde partie prend la forme dite « sur article », c'est-à-dire que les différents chapitres qui la compose sont des articles scientifiques publiés ou en cours de publication, elle est composée de trois études. (i) Une étude concernant la détection des trouées et des déterminants environnementaux sur la distribution de tailles des trouées en forêt non exploitée : Comment caractériser la distribution de taille des trouées et est-ce qu’il y a des déterminants environnementaux qui influencent la distribution statistique de taille de trouées? Cet article à été soumis dans Biogeoscience. (ii) Une étude du contrôle de l'environnement sur la structure et les variations de la hauteur de canopée à différentes résolutions spatiales. Quelles échelles spatiales sont pertinentes pour analyser les déterminants environnementaux des variations de hauteur de la canopée en forêt tropicale à partir des données de télédétection ? Comment l’environnement peut aider, ou pas, à cartographier la hauteur de la canopée en forêt tropicale ? Cet article à été accepté pour publication dans Remote Sensing. (iii) Une troisième étude où nous avons quantifié les effets de l’exploitation à faible impact (EFI) sur la structure et la variation de la hauteur de canopée. Quelles sont les effets de l’exploitation forestière sur les variations de hauteur de canopée et sur la distribution de taille des trouées ? Cet article sera soumis pour publication dans une revue scientifique (Forest Ecology and Management). Dans la dernière partie, après une synthèse des principaux résultats, nous proposons des pistes de développement.
https://tel.archives-ouvertes.fr/tel-01527553

NNT : 2016YANE0006
tel-01527553
https://tel.archives-ouvertes.fr/tel-01527553
https://tel.archives-ouvertes.fr/tel-01527553/document
https://tel.archives-ouvertes.fr/tel-01527553/file/these-youven-goulamoussene2.pdf

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Detection and attribution of human influence on sea level rise are important topics that have not yet been explored in depth. We question whether the sea level changes (SLC) over the past century were natural in origin. SLC exhibit power law long-term correlations. By estimating Hurst exponent through Detrended Fluctuation Analysis and by applying statistics of Lennartz and Bunde [2009], we search the lower bounds of statistically significant external sea level trends in longest tidal records worldwide. We provide statistical evidences that the observed SLC, at global and regional scales, is beyond its natural internal variability. The minimum anthropogenic sea level trend (MASLT) contributes to the observed sea level rise more than 50% in New York, Baltimore, San Diego, Marseille, and Mumbai. A MASLT is about 1 mm/yr in global sea level reconstructions that is more than half of the total observed sea level trend during the XXth century.
ISSN: 0094-8276

hal-01336190
https://hal.archives-ouvertes.fr/hal-01336190
https://hal.archives-ouvertes.fr/hal-01336190/document
https://hal.archives-ouvertes.fr/hal-01336190/file/BECKER2014a.pdf
DOI : 10.1002/2014GL061027

Éditeur(s) : HAL CCSD
Résumé : This thesis falls within the scope of social and human geography and more exactly of« disability studies ». Understanding the disability like a « social object », the thesis analyzes the societal consideration of disabled people in non-urbanized areas with a high issue of touristic, recreational and patrimonial development. In the first place, it's the recent construction of disability as a social object that is discussed by reminding the history of the societal consideration of the disabled person in our occidental world. The French model and his fundamental rule of global accessibility for ail the domains of the social life are explained and the « Nature and Disability » thematic is more precisely analyzed as a development of an active living ideal for people who are in a disability situation. Secondly, the thesis develops this thematic on the particular field of the Reunion Island and tries to answer to a question which is both simple and complicated: « Today, how we live with a disability on the Reunion Island? ». ln a last time and on the basis of this study of the disability inside a Reunion Island society with accelerated transformations, the thesis specifies the current tendencies with the emergence of new public policies for the welcome of disabled people on natural and touristic areas of the island. To conclude and referring to an original survey, the thesis suggests some tools of evaluation and decision-making aids to these areas.
Cette thèse s'inscrit dans le champ de la géographie humaine et sociale et plus précisément dans celui des « disability studies ». En positionnant le handicap comme une « figure du social », la thèse analyse la prise en compte sociétale des personnes à mobilité réduite (PMR) dans des environnements non urbanisés, à très fort enjeu de développement touristique, récréatif et patrimonial. Dans un premier temps, c'est la construction récente du handicap en tant que figure du social qui est abordée, en rappelant l'historique de la considération de la personne handicapée dans nos sociétés occidentales. Le modèle français et son principe fondamental d'accessibilité généralisée à tous les domaines de la vie sociale sont détaillés et la thématique « Nature et Handicap » est analysée plus précisément, en tant que développement d'un idéal de vie active pour les personnes en situation de handicap. Dans un second temps, la thèse développe cette thématique sur le terrain particulier de l'Île de La Réunion et tente de répondre à une question à la fois simple et complexe : « comment vit-on avec une déficience aujourd'hui à La Réunion ? ». Dans un dernier temps et sur la base de cette analyse du handicap au sein d'une société réunionnaise aux mutations accélérées, la thèse précise les tendances actuelles avec l'apparition de nouvelles politiques publiques d'accueil des PMR dans les espaces naturels et touristiques de l'île. S'appuyant sur une enquête originale, la thèse propose enfin des outils d'évaluation et d'aide à la décision spécifiques à ces espaces.
https://tel.archives-ouvertes.fr/tel-01279042

NNT : 2012LARE0025
tel-01279042
https://tel.archives-ouvertes.fr/tel-01279042
https://tel.archives-ouvertes.fr/tel-01279042/document
https://tel.archives-ouvertes.fr/tel-01279042/file/2012lare0025_AGuenat.pdf

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
While the effects of deforestation and habitat fragmentation on parasite prevalence or richness are well investigated, host-parasite networks are still understudied despite their importance in understanding the mechanisms of these major disturbances. Because fragmentation may negatively impact species occupancy, abundance and co-occurrence, we predict a link between spatiotemporal changes in habitat and the architecture of host-parasite networks. For this, we used an extensive data set on 16 rodent species and 29 helminth species from seven localities of South-East Asia. We analysed the effects of rapid deforestation on connectance and modularity of helminth-parasite networks. We estimated both the degree of fragmentation and the rate of deforestation through the development of land uses and their changes through the last 20 to 30years in order to take into account the dynamics of habitat fragmentation in our statistical analyses. We found that rapid fragmentation does not affect helminth species richness per se but impacts host-parasite interactions as the rodent-helminth network becomes less connected and more modular. Our results suggest that parasite sharing among host species may become more difficult to maintain with the increase of habitat disturbance.
ISSN: 0021-8790

hal-01355307
https://hal.archives-ouvertes.fr/hal-01355307
DOI : 10.1111/1365-2656.12368
IRD : fdi:010064927

Éditeur(s) : HAL CCSD
Résumé : International audience
La littérature existante sur la stabilité des systèmes est assez importante mais disparate et l’objet de ce livre est de réunir en un seul document les résultats essentiels sur la stabilité des systèmes dynamiques de dimension finie et leurs extensions dans le cas de dimension infinie. Comme les systèmes distribués évoluent dans le temps et l’espace, les explorations et les recherches sur leur stabilité étaient essentiellement centrées sur le domaine global dans lequel évolue le système. Nous avons fortement ressenti que, dans ce sens, des considérations importantes manquaient : celles qui consistentà considérer que le système peut faire l’objet d’intérêt dans une certaine région donnée de ce domaine global. Cela est le cas dans de nombreuses applications allant des sciences de l’ingénieur aux sciences du vivant. Pour cette raison, nous avons dédié cet ouvrage à une extension des résultats classiques au cas régional.Cet ouvrage s’adresse aux étudiants des licences et masters, aux élèves ingénieurs et aux chercheurs intéressés par la stabilité des systèmes dynamiques, sous diverses aspects. Il est organisé en suivant une difficulté croissante. Le premier chapitre portent sur la stabilité et la stabilisabilité des systèmes localisés (c’est-à-dire décrits par des équations différentielles ordinaires), puis sur la stabilité des systèmes linéaires distribués (c’est-à-diredécrits par des équations différentielles aux dérivées partielles). Les chapitres suivants concernent des aspects originaux et innovantsde la stabilité et la stabilisabilité de certaines classes de systèmes motivés par des applications réelles, c’est-à-dire les systèmes semilinéaireset bilinéaires. La stabilité de ces systèmes a été considérée d’un point de vue global et régional. Un aspect particulier concernant la stabilité du gradient a été également considéré pour diverses classes de systèmes.
https://hal.archives-ouvertes.fr/hal-01297263

ISBN : 978-2-35412-231-7
hal-01297263
https://hal.archives-ouvertes.fr/hal-01297263

Éditeur(s) : HAL CCSD
Résumé : International audience
GEOBIA 2012
Rio de Janeiro, France

hal-01107866
https://hal.archives-ouvertes.fr/hal-01107866