Éditeur(s) : INRA
Résumé : According to the world organisation for animal health (OIE) an emerging disease is defined as a recently admitted serious illness, whose aetiology can, or not, have already been established, and which is likely to be propagated within a population or between populations, for example at the time of international exchanges of aquatic animals and/or products of aquatic animals. Even though the emerging diseases that affect human health have been much studied, those which affect marine organisms and species of aquaculture interest in particular are poorly documented. By restricting emergence to only infectious diseases, we aim at presenting in a non-exhaustive way some scenarios of the emergence of the diseases of aquacultured species by illustrating them with three examples available in the scientific literature: one relating to the appearance of a pathogenic agent in a new host with the case of the herpesvirus of the Koï carp, the other with the evolution of a pre-existing pathogenic agent with the case of shrimp vibriosis due to Vibrio nigripulchritudo in New Caledonia, and the last example relating to the introduction of one pathogenic pre-existing pathogen in an unscathed area with the case of Bonamia ostreae infecting the flat oyster Ostrea edulis. The causes of the emergence of diseases are multiple and implicate in an intercurrent way pathogenic agents, the environment, the host or host species and anthropogenic factors. In the marine environment, these causes are very often ignored. In this context, the development of zoosanitary surveillance networks and diagnostic tools present a considerable interest in order to anticipate, prevent and/or intervene on the emergence of the diseases by limiting their sanitary, ecological and political consequences.
Selon l'Office International des Epizooties (OIE) une maladie émergente désigne une maladie grave récemment reconnue, dont la cause peut, ou non, avoir déjà été établie, et qui est susceptible de se propager au sein d'une population ou entre des populations, par exemple à l'occasion d'échanges internationaux d'animaux aquatiques et/ou de produits d'animaux aquatiques. Si les maladies émergentes qui affectent la santé humaine ont été très étudiées, celles qui touchent les organismes marins et les organismes aquacoles d'intérêt économique en particulier sont en revanche peu documentées. C'est en restreignant l'émergence aux seules maladies infectieuses que seront présentés de façon non exhaustive quelques scénarios de l'émergence des maladies chez les organismes d'intérêt aquacole en les illustrant par trois exemples disponibles dans la littérature scientifique : l'un relatif à l'apparition d'un agent pathogène chez un nouvel hôte avec le cas de l'herpesvirus de la carpe Koï, l'autre à l'évolution d'un agent pathogène existant avec le cas de la vibriose à Vibrio nigripulchritudo sévissant dans les élevages de crevettes pénéides de Nouvelle-Calédonie et enfin le dernier lié à l'introduction d'un pathogène préexistant avec le cas de Bonamia ostreae infectant l'huître plate Ostrea edulis. Les causes d'émergence de maladies sont multiples et font intervenir de façon intercurrente l'agent pathogène, l'environnement, l'hôte ou les espèces hôtes et des facteurs anthropiques. Dans le milieu marin, ces causes sont bien souvent méconnues. Dans ce contexte le développement des réseaux de surveillance et des techniques de diagnostic revêtent un intérêt considérable afin d'anticiper, de prévenir et/ou d'intervenir sur l'émergence des maladies en limitant leur conséquences sanitaires, écologiques et politiques.
INRA Productions Animales (INRA), 2007-07 , Vol. 20 , N. 3 , P. 207-212

Droits : INRA
http://archimer.ifremer.fr/doc/2007/publication-2980.pdf
http://archimer.ifremer.fr/doc/00000/2980/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Standard microbial evolutionary ontology is organized according to a nested hierarchy of entities at various levels of biological organization. It typically detects and defines these entities in relation to the most stable aspects of evolutionary processes, by identifying lineages evolving by a process of vertical inheritance from an ancestral entity. However, recent advances in microbiology indicate that such an ontology has important limitations. The various dynamics detected within microbiological systems reveal that a focus on the most stable entities (or features of entities) over time inevitably underestimates the extent and nature of microbial diversity. These dynamics are not the outcome of the process of vertical descent alone. Other processes, often involving causal interactions between entities from distinct levels of biological organisation, or operating at different time scales, are responsible not only for the destabilisation of pre-existing entities, but also for the emergence and stabilisation of novel entities in the microbial world. In this article we consider microbial entities as more or less stabilised functional wholes, and sketch a network-based ontology that can represent a diverse set of processes including, for example, as well as phylogenetic relations, interactions that stabilise or destabilise the interacting entities, spatial relations, ecological connections, and genetic exchanges. We use this pluralistic framework for evaluating (i) the existing ontological assumptions in evolution (e.g. whether currently recognized entities are adequate for understanding the causes of change and stabilisation in the microbial world), and (ii) for identifying hidden ontological kinds, essentially invisible from within a more limited perspective. We propose to recognize additional classes of entities that provide new insights into the structure of the microbial world, namely ``processually equivalent'' entities, ``processually versatile'' entities, and ``stabilized'' entities.
ISSN: 0169-3867

hal-01544796
https://hal.archives-ouvertes.fr/hal-01544796
DOI : 10.1007/s10539-012-9350-2

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Les îles sont devenues les principaux marchés mondiaux pour le tourisme balnéaire en profitant de leur richesse naturelle et culturelle. Dans le même temps, les îles sont des territoires fragiles avec des ressources limitées, raison pour laquelle un développement durable de l’activité touristique est une nécessité. L'étude de la consommation des ressources naturelles par le tourisme est une étape essentielle pour détecter les menaces que cette activité cause à l'environnement et donc la mise en œuvre de mesures plus durables. Dans cet article, nous analysons la consommation des ressources naturelles dans cinq régions touristiques de Minorque. Les données ont été recueillies auprès des fournisseurs, des établissements touristiques et au travail d’enquête terrain, ainsi cela nous a permis d'estimer la consommation d'eau et d'électricité, la production et la collecte des déchets pour les études de cas. Les consommations élevées d’eau et de déchets observés indiquent la nécessité d'entreprendre des actions. D'autre part, les résultats montrent que les coûts environnementaux les plus élevés proviennent des établissements touristiques fondés sur la faible densité de ménage.
Islands have become world’s leading markets for sun and sand tourism taking advantage of their natural and cultural richness. At the same time, islands are fragile territories with limited resources, reason why a sustainable development of tourism is a necessity. The study of natural resources consumption by tourism is an essential step to detect the threats that this activity is causing to the environment and thus implement measures to go towards a more sustainable direction. In this article we analyze the natural resources consumption in five tourist areas of Menorca. Data were gathered from supplier companies, tourist establishments and through fieldwork, and allowed us to estimate water and electricity consumption, generation and collection of waste for the case studies. The high observed ratios of water consumption as well as waste generation and collection ratios indicate the need to undertake actions. The results showed the higher environmental costs of tourism settlements based on low density of household.
Espagne
Minorque

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6267
http://journals.openedition.org/etudescaribeennes/6267

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 15-19 octobre 1999
Résumé : The Mediterranean small-scale fleet is highly adaptive, showing a dynamic fishing intensity and strategy, and exploiting seasonal abundant resources. In this area, the aggregatory behaviour under floats of juvenile fish has been used since ancient times to exploit oceanic migratory species such as dolphinfish (Coryphaena hippurus), using Fish Aggregating anchored Devices (fads). A total of 2 300 boats are engaged in this fishery from August to December, the main fishing areas being those around Malta, Tunisia, Sicily and Majorca. The fads ( arrow right m2) are made of different cheap floating materials, and are moored in fixed places, ranging from shore waters to areas 60 miles off the coast (1 500 m depth). Each boat deploys an average of 20 to 100 fads. The gears used are special surrounding nets without purse line, and traditional purse seine nets. The fishery exploits young-of-the-year dolphinfish (<6 months old), originated by a pre-spawning migration of adults from Atlantic waters. Their catches show high annual and monthly variability, depending on the recruitment and the accessibility of recruits to the fishery. Pilotfish (Naucrates ductor) and greater amberjack (Seriola dumerili) are also exploited in this fishery as by-catch. A total of about 1 000 metric tons of dolphinfish are yearly caught mainly in September-October. The fads are historically laid in August. Recently, the fads fishing period has increased in Sicily, and the fads are laid in July, so as to catch pilotfish and greater amberjak juveniles. In recent years, the interest for this fishing method and the study of these fisheries has increased in the Mediterranean. Though the market and its seasonality limit this exploitation, this fishery is economically profitable with good revenue.

Droits : Ifremer
http://archimer.ifremer.fr/doc/00042/15286/12672.pdf
http://archimer.ifremer.fr/doc/00042/15286/

Éditeur(s) : Elsevier
Résumé : Previous studies conducted on the continental shelf in the Southeast Bay of Biscay influenced by Gironde waters (one of the two largest rivers on the French Atlantic coast) showed the occurrence of late winter phytoplankton blooms and phosphorus limitation of algal growth thereafter. In this context, the importance of dissolved organic phosphorus (DOP) for both algae and bacteria was investigated in 1998 and 1999 in terms of stocks and fluxes. Within the mixed layer, although phosphate decreased until exhaustion from winter to spring, DOP remained high and phosphate monoesters made up between I I to 65% of this pool. Total alkaline phosphatase activity (APA, V-max) rose gradually from winter (2-8 nM h(-1)) to late spring (100-400 nM h-1), which was mainly due to an increase in specific phytoplankton (from 0.02 to 3.0 nmol mu gC(-1) h(-1)) and bacterial APA (from 0.04 to 4.0 nmol mu gC(-1) h(-1)), a strategy to compensate for the lack of phosphate. At each season, both communities had equal competitive abilities to exploit DOP but, taking into account biomass, the phytoplankton community activity always dominated (57-63% of total APA) that of bacterial community (9-11%). The dissolved APA represented a significant contribution. In situ regulation of phytoplanktonic APA by phosphate (induction or inversely repression of enzyme synthesis) was confirmed by simultaneously conducted phosphate-enrichment bioassays. Such changes recorded at a time scale of a few days could partly explain the seasonal response of phytoplankton communities to phosphate depletion.
Journal of Experimental Marine Biology and Ecology (0022-0981) (Elsevier), 2005-05 , Vol. 318 , N. 2 , P. 213-225

Droits : 2005 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/2005/publication-608.pdf
DOI:10.1016/j.jembe.2004.12.017
http://archimer.ifremer.fr/doc/00000/608/

Résumé : La distribution actuelle des espèces d’arbres des forêts tropicales humides amazoniennes est le résultat de processus dynamiques sur lesquels les perturbations passées, d’origine climatique ou anthropique, peuvent avoir jouées un rôle majeur. Des outils génétiques actuels associés à des méthodes d’analyses puissantes permettent d’inférer et de dater l’empreinte génomique des évènements démographiques subits par les populations naturelles. Le but de cette thèse est de contribuer à une vision d’ensemble de l’évolution démographique de la forêt tropicale humide du plateau des Guyanes pendant le Quaternaire. J’ai d’abord étudié les propriétés des microsatellites (répétitions simple de séquences, SSR) et les limites de leurs applications en tant que marqueurs moléculaires en phylogéographie. Plusieurs allèles SSR contenu dans diverses populations de trois genres d’arbres différents ont été séquencés et le polymorphisme, porté par chaque partie des fragments ADN contenant des SSR, a été étudié. J’ai observé que la quantité de variation génétique était aussi importante dans les régions encadrant le microsatellite que dans le SSR lui-même. Ces régions ont contribué significativement à l’information phylogénétique et ont parfois été la principale source de différenciation entre les individus et les populations. Cette expérience m’a permis de choisir la meilleure stratégie à adopter pour traiter les données de variation génétique des SSR dans des modèles démographiques. J’ai ensuite utilisé ces marqueurs SSR et des méthodes ABC pour étudier l’impact local des occupations humaines précolombiennes sur les forêts en Guyane française. Les changements démographiques subis par des populations de quatre espèces d’arbres ont été comparés entre cinq sites occupés et quatre sites non perturbés. Les perturbations naturelles et induites par l’homme ont contribué à la mise en place de la diversité observée actuellement, comme le suggère des signatures d’effet fondateur détectées sur les sites perturbés ou non. Néanmoins, la taille des populations fondatrices semble être proportionnelle à l’impact humain estimé, indiquant que les perturbations anthropique ont induit un remplacement des populations plus important que les processus écologiques naturels. Pour terminer, j’ai mené une étude de démographie comparative d’espèces d’arbres tropicaux à l’échelle régionale de la Guyane française. Cinq scénarios démographiques ont été testés pour neuf populations de huit espèces en utilisant des microsatellites nucléaires et des séquences chloroplastiques. Les changements démographiques les plus récents détectés convergent vers une signature générale d’expansion de la forêt humide depuis probablement la dernière glaciation. Cela peut suggérer, soit que la composition des forêts du plateau des Guyanes était différente, ou que le couvert forestier était moins étendu. Ce résultat constitue le premier indice de changement passé, probablement d’origine climatique, subi par les communautés forestières du plateau des Guyanes ; qui n’avait jusque-là pas pu être testé avec des méthodes standards en raison d’un manque de fossiles. En conclusion, j’ai recueilli des preuves génétiques que les perturbations, à différents échelles de temps, ont marqué la structure et la composition génétique des forêts du plateau des Guyanes. L’application de ces méthodes à d’autres régions Néotropicales pourrait contribuer, à l’avenir, à reconstruire l’histoire écologique de la forêt amazonienne de façon détaillée.
The current tree species distribution in Amazonian tropical rainforests is the outcome of dynamic processes in which past perturbations, climatic or anthropogenic, may have played a major role. Currently available genetic tools associated with powerful analytical methods allow inferring and dating the genomic imprint of demographic events undergone by natural populations. The aim of my thesis is to contribute to an overview of the demographic evolution of the tropical rainforest in the Guiana shield during the Quaternary. I have first studied the properties of microsatellites or Simple sequence repeat (SSR) and the limits in their applications as molecular markers in phylogeography. Several SSR alleles in multiple populations of three divergent tree genera have been sequenced and the sources of polymorphisms, carried by each portion of SSR-containing DNA amplicons, have been broken apart. I have observed that the amount of variation was as large in flanking regions as in the SSR itself. The former contributed significantly to the phylogenetic information and sometimes was the main source of differentiation among individuals and populations. This experiment allowed me to choose the best strategy to treat SSR variation in demographic modeling. I have subsequently used SSR markers and ABC methods to study the impact of pre-Columbian human settlements at the local level on rainforests in French Guiana. Demographic changes undergone by populations of four tree species were compared between five settled and four undisturbed sites. Both natural turnover and human-induced disturbances appeared as shaping currently observed genetic diversity, with signatures of founder effect both at disturbed and undisturbed sites. Nevertheless, the size of founding populations appeared to be proportional to the estimated human impact, suggesting that human-made disturbance caused deeper population turnover than background ecological processes. Finally, I have conducted a comparative demography study of tropical tree species at the regional level across French Guiana. Five demographic scenarios have been tested for nine populations from eight species using both nuclear microsatellites and chloroplastic sequences. The most recent demographic signals detected converge on a global signature of expansion of the rainforest since probably the last glaciation. This finding can suggest either that the composition of the Guiana shield rainforests was different, or that its global extent was smaller, during earlier epochs of the Pleistocene than today. This result is the first firm indication of changes undergone by the forest communities of the Guiana shield in the distant climatic past – something which could not be tested with standard methods due to almost complete lack of fossil evidence. In conclusion, I have gathered genetic evidence that disturbances, both in historical and geological times, have marked the structure and composition of forests in the Guiana shield.The extensive application of these methods to other regions of the Neotropics maycontribute, in the future, to the detailed reconstruction of the ecological history ofAmazonian forests.

http://www.theses.fr/2012AGUY0568/document

Éditeur(s) : HAL CCSD EDP Sciences
Résumé : International audience
We show that the so-called low-regret (or least-regret) control by J. L. Lions [8] fits on the control of ill-posed problems. At each time, we give the characterization of the so-called no-regret control by means of singular optimality systems. For the backward heat ill-posed problem, no Slater hypothesis is assumed on the admissible set of controls ${{cal U}_{mbox{ iny ad}}}$. This work is two pieces, and two methods are considered : the regularization method and the null-controllability method. For the first method, a zero order corrector is used, while for the second method, the passage to the limit is easy. The results presented here generalize the works in [2,3] to the no-regret control.
ISSN: 1270-900X

hal-00720814
https://hal.univ-antilles.fr/hal-00720814
https://hal.univ-antilles.fr/hal-00720814/document
https://hal.univ-antilles.fr/hal-00720814/file/esaimpr1.pdf

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
1. The use of targets to provide measurable objectives and benchmarks for management, conservation, andrestoration of ecosystems is commonplace. In the marine and coastal realms, targets have been successful insetting sustainable limits to fisheries harvests, thresholds for pollutants, and recommended amounts ofrepresentative habitat included in marine protected area (MPA) networks. Quantifiable targets can dissuadegovernments from making dubious claims about investments in ocean protection that sound impressive butcannot be verified. Examples are presented where protection targets have been used successfully for marinemanagement, and instances where measurable and meaningful benchmarks serve to allow tracking of true progress.2. However, the setting of targets can also be a double-edged sword. In some cases, targets have proven useful,but in many instances, interventions made to fulfil targets not only give a false illusion of progress or even success,they present opportunity costs that impede further conservation.3. Some of these issues were raised in the 2003 article ‘Dangerous Targets?: Unresolved issues and ideologicalclashes around marine protected areas’ that appeared in Aquatic Conservation: Marine and FreshwaterEcosystems. Since its publication, the article’s warnings about how targets can sometimes be dangerous andcounter-productive have led to intense debate among scientists and policy-makers alike, and the paper has beencited in more than 500 publications. Yet today, more than a dozen years after the first ‘Dangerous Targets’publication, new targets are driving more MPA designations and conservation strategies than ever before, andthe ‘dangerous’ aspects of target setting have been largely ignored.4. This paper discusses old ‘dangers’ in the context of new developments in marine conservation, including thelingering problem of having simplistic metrics drive marine policies, and the unintended result that can often occurwhen outputs (percentage of area under MPA designation) do not align with true outcomes of effectivemanagement and conservation. Newly emerging ‘dangers’ in letting areal targets (percentage of area underMPA designation) drive MPA designations are also discussed, including how the rush to fulfil obligations toprotect a certain proportion of area is taking place in planning, separate from broader level, and potentiallymore holistic, marine spatial planning (MSP).5. The paper suggests five recommendations that would allow policy-makers to use targets more effectively,including: (1) increase transparency in planning, especially around specific goals and objectives of MPAestablishment; (2) use time-based areal targets when representativity is a goal of the protected area strategy; (3)
ISSN: 1052-7613

hal-01380963
https://hal-univ-perp.archives-ouvertes.fr/hal-01380963
DOI : 10.1002/aqc.2675

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Understanding long-term variability in the frequency of intense storm activity is important for assessing whether changes are controlled by climate evolution. Understanding this variability is also important for predicting present and future community vulnerability and economic loss. Our ability to make these assessments has been limited by the short (less than 50 years) instrument record of storm activity. Storm-induced deposits preserved in the sediments of coastal lagoons offer the opportunity to study the links between climatic conditions and storm activity on longer timescales. In this study, we present a record of these extreme climatic events that have occurred in the French Mediterrannean coast over the past 1500 years. The identification of these extreme events is based on the analysis of sediment cores from Gulf of Aigues-Mortes lagoons that contain a specific sedimentary and geochemical signature associated with intense storms.;Overwash deposits do not show any evidence of intense storm landfalls in the region for several hundred years prior to the late 17th century A.D. The apparent increase in intense storms around 250 years ago occurs during the latter half of the Little Ice Age, a time of lower continental surface temperatures. Comparison of the sediment record with palaeoclimate records indicates that this variability was probably modulated by atmospheric dynamics. The apparent increase of the superstorm activity during the latter half of the Little Ice Age was probably due to the thermal gradient increase leading to enhanced lower tropospheric baroclinicity over a large Central Atlantic/European domain and leading to a modification of the occurrence of extreme wind events along the French Mediterranean coast. A complete understanding of the relationship between climate fluctuations, storm activity, and the coastal response will be crucial to predicting the impacts of future climate change.
ISSN: 0031-0182

hal-00617525
https://hal.archives-ouvertes.fr/hal-00617525
DOI : 10.1016/j.palaeo.2010.11.009

Éditeur(s) : HAL CCSD Universidad Complutense de Madrid
Résumé : The Lodève Permian synrift sequence is represented by thick stacked climate-controled playa cycles which have been constrained by structural, sedimentological, geochemical and paleontological processes. The present paper merges the different results in order to better constrain the dynamics and palaeoecologycal evolution of the playa system from Late Cisuralian to Early Lopingian time. In this depositional environment, thining upwards sheet-flood sequences represent flooding events; they are relayed by ephemeral ponding, suspension settling and limited carbonate precipitation accompanied by large amounts of shallow to subaerial sedimentary structures... (Ver más) (current and wind ripples, desiccation cracks, rain drops, etc.). The aridity of the climate contrasts with the surprising abundance of the fauna encountered into carbonate-rich silty-clay playa-lake deposits. Ephemeral pools are colonized by numerous shellfish: Choncostraca, Triopsids, and Insects, which led to intense burrowing of the overbank deposits (Scoyenia facies). Tetrapods are common and dominated by several types of reptiles after footprints: Pelycosauria, Parareptilia and Lepidosauria in the Rabejac Fm, and Mammalian reptiles (Therapsida) on the top of the fluvial deposits of the Salagou Fm near La Lieude farm. In addition, elements of a weighty herbivorous Pelycosaurian and a small amphibian Tupilakosaurid, only described in the Triassic before, have been also found in the Upper part of the Permian series of this sector.
ISSN: 1698-6180

hal-00411539
https://hal.archives-ouvertes.fr/hal-00411539

Résumé : La dengue constitue actuellement l'arbovirose la plus répandue sur la planète avec 40% de la population mondiale exposée, soit environ 2,5 milliards de personnes. La maladie est endémique dans tous les continents excepté l'Europe même si les premiers cas de transmission autochtone ont été observés en France métropolitaine et en Croatie en 2010. L'augmentation régulière de son incidence fait actuellement de la dengue un problème de santé publique majeur dans les pays tropicaux et une menace pour d'autres pays du monde. En raison de son mode de transmission, la dengue constitue une maladie étroitement liée à l'environnement. L'urbanisation constitue un facteur important dans l'émergence ou la réémergence d'épidémies de dengue dans les pays tropicaux. Cette étude menée a pour objet d'analyser les liens existant entre le domaine de la santé (situation sanitaire et épidémiologique de la dengue) et de celui de l'environnement (évolution de l'urbanisation) en Guadeloupe continentale entre 2000 et 2008.Pour ce faire, les cas suspects et confirmés de dengue ont été recueillis. L'incidence pour ces deux types de cas a été calculée puis représentée à deux échelles administratives différentes: communes et sections. Les facteurs environnementaux comprenant les variables physiques et socio-démographiques ont été pris en compte pour la définition, l'identification et l'analyse de l'évolution des contextes d'habitation durant la période étudiée. Deux méthodes ont été utilisées: la classification «Raster» consistant en une analyse régulière basée sur des mailles de taille identique et la classification « Vecteur» s'appuyant sur les limites administratives des sections. Ces classifications ont permis de décrire la répartition des différents contextes d'habitation sur le territoire de la Guadeloupe et d'obtenir des indicateurs qui ont été analysés en relation avec les données sanitaires. Il a été mis en évidence que la situation épidémiologique de la dengue dans le département s'est significativement aggravée au cours de la période étudiée. Des épidémies majeures sont apparues en 2001, 2005/2006 et 2007. Le nord Basse-Terre, la région Pointoise ainsi que le sud-est de la Grande-Terre, de la ville du Gosier à Saint-François le long de la côte, sont les régions les plus concernées par l'augmentation d'incidence de la maladie. Concernant les contextes d'habitation, huit contextes distincts ont été identifiés: touristique, naturel, intermédiaire, agricole, résidentiel, rural, périurbain et urbain. Le contexte intermédiaire correspond à des régions de transition entre les autres contextes d'habitation. La différence entre les contextes agricoles et ruraux réside dans la prédominance de surface agricole pour le premier alors que le contexte rural est caractérisé par les espaces cultivés habités. L'évolution surfacique de ces contextes au cours du temps a été analysée en relation avec les incidences. Les résultats montrent que les contextes d'habitation sont statistiquement.associés à l'incidence de la dengue en Guadeloupe. En particulier, les contextes touristiques, résidentiels et ruraux possèdent une association positive élevée avec l'incidence de la dengue.
At present, dengue fever has become the arbovirose the most wide-spread worldwide with 40 % ofthe exposed population, 2,5 billion people. The disease is endemie in all the continents excepted Europe even though the fust cases ofautochthonoustransmissionwere observedinmetropolitanFranceandCroatiain2010.Because oftherecentincrease of its incidence, dengue fever is now a major public health problem in the tropical countries and a threat for the other countries in the worldwide. Due to its mode oftransmission, the disease is closely linked to the environment. Urbanization is an important factor ofthe emergence or the re-emergence of dengue in the tropical countries. This study aims to analyze the links between health and environment domains, which correspond to the epidemiological situation of the dengue and the evolution ofthe urbanization in Guadeloupe.Information about suspect and confirmed cases of dengue were collected. The incidence of suspect and confirmed cases has been estimated, then represented at two different administrative boundaries: communes and sections. Environmental factors including the physical and socio-demographic variables were taken into account to the definition, the identification and the analyze ofevolution of the housing patterns during the studied period. Two methods were used: Il Raster" consisting of a regular analysis based on squares units and "Vector" based on the administrative limits of sections. These classifications allowed to describe the distribution ofthe different housing patterns ofGuadeloupe and to estimate indicators for the analyzing of sanitary data. The results highlight a worsening ofepidemiological situation ofthe dengue over the time in the department. Major outbreaks occurred in 2001,2005/2006 and 2007. The north Basse-Terre, the Pointe-à-Pitre urban area as weIl as the whole coast (frOID the city of Gosier to Saint-François) ofthe southeast ofGrande-Terre were the most affected regions by the increase ofincidence of dengue. Concerning the housing classes, eight different patterns were identified: tourist, natural, intermediate, agricultural, residential, rural, suburban and urban. The intermediate class corresponds to buffer regions between the other patterns. The difference between the agricultural and rural contexts lies in the predominance ofagricultural surface for the first one while the rural context is characterized by the inhabited farmland. The evolution over time of spatial extend ofthese patterns was described in relation with incidence. Results showed that the housing patterns are statically associated with the incidence ofdengue in Guadeloupe. In particular, the touristic, residential and rural patterns have a high positive association with dengue incidence.

http://www.theses.fr/2012AGUY0565/document

Éditeur(s) : American Geophysical Union
Résumé : Noise with periods 3 to 10 s, ubiquitous in seismic records, is expected to be mostly generated by pairs of ocean wave trains of opposing propagation directions with half the seismic frequency. Here we present the first comprehensive numerical model of microseismic generation by random ocean waves, including ocean wave reflections. Synthetic and observed seismic spectra are well correlated (r > 0.85). On the basis of the model results, noise generation events can be clustered in three broad classes: wind waves with a broad directional spectrum (class I), sea states with a significant contribution of coastal reflections (class II), and the interaction of two independent wave systems (class III). At seismic stations close to western coasts, noise generated by class II sources generally dominates, but it is intermittently outshined by the intense class III sources, limiting the reliability of seismic data as a proxy for storm climates. The modeled seismic noise critically depends on the damping of seismic waves. At some mid-ocean island stations, low seismic damping is necessary to reproduce the observed high level and smoothness of noise time series that result from a spatial integration of sources over thousands of kilometers. In contrast, some coastal stations are only sensitive to noise within a few hundreds of kilometers. This revelation of noise source patterns worldwide provides a wealth of information for seismic studies, wave climate applications, and new constraints on the possible directional distribution of wave energy.
Journal of Geophysical Research ( JGR ) - Oceans (0148-0227) (American Geophysical Union), 2011-09 , Vol. 116 , N. C09004 , P. 21 p.

Droits : 2011 by the American Geophysical Union
http://archimer.ifremer.fr/doc/00044/15531/12926.pdf
DOI:10.1029/2011JC006952
http://archimer.ifremer.fr/doc/00044/15531/

Éditeur(s) : University of Tasmania, Université de Bretagne Occidentale
Résumé : Empirical evidence and the theoretical literature both point to stock sustainability and the protection of marine biodiversity as important fisheries management issues. Decision-support tools are increasingly required to operationalize the ecosystem-based approach to fisheries management. These tools need to integrate (i) ecological and socio-economic drivers of changes in fisheries and ecosystems; (ii) complex dynamics; (iii) deal with various sources of uncertainty; and (iv) incorporate multiple, rather than single objectives. The stochastic co-viability approach addresses the trade-offs associated with balancing ecological, economic and social objectives throughout time, and takes into account the complexity and uncertainty of the dynamic interactions which characterize exploited ecosystems and biodiversity. This thesis proposes an application of this co-viability approach to the sustainable management of mixed fisheries, using two contrasting case studies: the French Bay of Biscay (BoB) demersal mixed fishery and the Australian Northern Prawn Fishery (NPF). Both fisheries entail direct and indirect impacts on mixed species communities while also generating large economic returns. Their sustainability is therefore a major societal concern. A dynamic bio-economic modelling approach is used to capture the key biological and economic processes governing these fisheries, combining age- (BoB) or size- (NPF) structured models of multiple species with recruitment uncertainty, and multiple fleets (BoB) or fishing strategies (NPF). Economic uncertainties relating to input and output prices are also considered. The bioeconomic models are used to investigate how the fisheries can operate within a set of constraints relating to the preservation of Spawning Stock Biomasses (BoB) or Spawning Stock Size Indices (NPF) of a set of key target species, maintenance of the economic profitability of various fleets (BoB) or the fishery as a whole (NPF), and limitation of fishing impacts on the broader biodiversity (NPF), under a range of alternative scenarios and management strategies. Results suggest that under a status quo strategy both fisheries can be considered as biologically sustainable, while socio-economically (and ecologically in the NPF case) at risk. Despite very different management contexts and objectives, viable management strategies suggest a reduction in the number of vessels in both cases. The BoB simulations allow comparison of the trade-offs associated with different allocations of this decrease across fleets. Notably, co-viability management strategies entail a more equitable allocation of effort reductions compared to strategies aiming at maximizing economic yield. In the NPF, species catch diversification strategies are shown to perform well in controlling the levels of economic risk, by contrast with more specialized fishing strategies. Furthermore analyses emphasize the importance to the fishing industry of balancing global economic performance with inter-annual economic variability. Promising future developments based on this research involve the incorporation of a broader set of objectives including social dimensions, as well as the integration of ecological interactions, to better address the needs of ecosystem-based approaches to the sustainable harvesting of marine biodiversity.
L’objectif général de la thèse est de modéliser les principaux processus biologiques et économiques régissant des pêcheries multi-espèces et multi-flottilles afin de proposer des stratégies viables pour la gestion durable de ces pêcheries mixtes, dans un contexte stochastique et multiobjectif. Plus spécifiquement, cette thèse utilise des analyses de co-viabilité stochastique pour étudier les arbitrages entre des objectifs contradictoires de gestion (conservation, et viabilité économique et sociale) des pêcheries mixtes. Deux pêcheries mixtes sont analysées dans cette thèse: la pêcherie française mixte démersale du golfe de Gascogne et la pêcherie crevettière australienne du Nord (NPF). Ces deux pêcheries sont multi-espèces, et utilisent des stratégies multiples de pêche, induisant des impacts directs et indirects sur les écosystèmes. Cette thèse propose une application de la co-viabilité stochastique à ces deux cas, en prenant en compte leur histoire, leur contexte socio-politique et les différences dans les stratégies et objectifs de gestion. Les résultats suggèrent que le status quo peut être considéré comme une stratégie biologiquement durable mais socio économiquement à risque dans les deux pêcheries (ainsi qu’à risque écologique dans le cas de la pêcherie australienne). Les simulations réalisées pour le golfe de Gascogne permettent de comparer les arbitrages associés à différentes réductions de capacités par flottille et de montrer qu’il existe des solutions de gestion permettant la co-viabilité du système (viabilité biologique des différentes espèces considérées et viabilité socio-économique des flottilles) contrairement à des stratégies de gestion mono-spécifiques ou basées sur la maximisation de la rente. Dans la pêcherie crevettière australienne, l’analyse montre que les stratégies de diversification permettent de limiter le risque économique contrairement aux stratégies plus spécialisées.

Droits : UBO, Univ. Tasmania
http://archimer.ifremer.fr/doc/00206/31731/30134.pdf
http://archimer.ifremer.fr/doc/00206/31731/

Éditeur(s) : HAL CCSD Elsevier
Résumé : We have integrated the relatively unknown distal domains of the Lower Congo basin, where the main depocenters of the Congo submarine fan are located, with the better-constrained successions on the shelf and upper slope, through the analysis of thousands of km of 2D seismic reflection profiles off-shore the Congo-Angola passive margin. The basin architecture is depicted by two ca. 800-km-long regional cross sections through the northern (Congo) and southern (Angola) margin. A large unit deposited basinward of the Aptian salt limit is likely to be the abyssal-plain equivalent of the upper-Cretaceous carbonate shelf that characterized the first post-rift deposits in West-equatorial African margins. A latest-Turonian shelf-deepening event is recorded in the abyssal plain as a long period (Coniacian-Eocene) of condensed sedimentation and basin starvation. The onset of the giant Tertiary Congo deep-sea fan in early Oligocene following this event reactivates the abyssal plain as the main depocenter of the basin. The time-space partitioning of sedimentation within the deep-sea fan results from the interplay among increasing sediment supply, margin uplift, rise of the Angola salt ridge, and canyon incision throughout the Neogene. Oligocene-early Miocene turbidite sedimentation occurs mainly in NW-SE grabens and ponded inter-diapir basins on the southern margin (Angola). Seaward tilting of the margin and downslope salt withdrawal activates the up-building of the Angola escarpment, which leads to a northward (Congo) shift of the transfer zones during late Miocene. Around the Miocene-Pliocene boundary, the incision of the Congo submarine canyon confines the turbidite flows and drives a general basinward progradation of the submarine fan into the abyssal plain The slope deposition is dominated by fine-grained hemipelagic deposits ever since. Results from this work contribute to better understand the signature in the ultra-deep deposits of processes acting on the continental margin as well as the basin-wide sediment redistribution in areas of high river input.
ISSN: 0040-1951

hal-00424533
https://hal.archives-ouvertes.fr/hal-00424533
DOI : 10.1016/j.tecto.2008.04.009

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

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

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
We examine absolute gravity (AG) and vertical Global Positioning System (GPS) time series between 1995 and 2010 at eight collocated sites in mid-continent North America. The comparison of AG and GPS rates aligned to ITRF2005 yields a gravity/uplift ratio of -0.17 +/- 0.01 mu Gal mm(-1) (1 mu Gal = 10 nm s(-2)) and an intercept of -0.1 +/- 0.5 mm yr(-1). In contrast, aligning the GPS velocities to ITRF2000 results in a gravity/uplift intercept of -1.3 +/- 0.5 mm yr(-1). The near-zero gravity/uplift offset for the ITRF2005 (or ITRF2008) results shows a good alignment of the GPS vertical velocities to Earth's center of mass, and confirms that GPS velocities in this reference frame can be compared to predictions of geodynamic processes such as glacial isostatic adjustment (GIA) or sea-level rise. The observed gravity/uplift ratio is consistent with GIA model predictions. The ratio remains constant in regions of fast and slow uplift, indicating that GIA is the primary driving process and that additional processes such as local hydrology have a limited impact on a decadal time-scale. Combining AG and GPS measurements can provide significant constraints for geodetic, geodynamic, and hydrological studies. Citation: Mazzotti, S., A. Lambert, J. Henton, T. S. James, and N. Courtier (2011), Absolute gravity calibration of GPS velocities and glacial isostatic adjustment in mid-continent North America, Geophys. Res. Lett., 38, L24311, doi:10.1029/2011GL049846.
ISSN: 0094-8276

hal-00689010
https://hal.archives-ouvertes.fr/hal-00689010
DOI : 10.1029/2011GL049846

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In this study, we quantify and analyze the spatial and temporal evolution of the surface displacement of Kahrod landslide located in the center of Alborz range (Iran) within the Haraz valley. This landslide represents a threat for this main drainage axis and its numerous infrastructures. We present three sets of displacement vectors based on GPS technique. An 8-benchmark network has been surveyed four times on a 1-year period basis. It provides accurate information on the rate of displacement within the landslide, and addresses the problem of the mechanical resistance of a small hillock, down slope, under the stress imposed by the landslide. Then. this network is densified (57 marks) and measured twice in 6 months using a rapidstatic approach. This yields to a dense description of surface deformation over the whole landslide. Finally, a 1-year time series of permanent GPS recordings is presented and compared to rainfall. Furthermore, we analyze Envisat radar differential interferograms (DInSAR) spanning the same period as permanent GPS. These geodetic data allow to precisely determine the limits of the current sliding zone and to describe the spatial and temporal evolution of surface displacement. The combination of geodesy and field observations leads to a precise description of the past and present kinematics behavior of Kahrod landslide. The chaotic nature of the sliding mass suggests a first catastrophic landslide in a first episode. During the period of observation, the landslide appears to deform quite steadily, and the evidence of short-term correlation between rainfall and deformation amplitude needs to be confirmed by future measurements. Carrying on the acquisition of GPS and InSAR data within the sliding mass but also within adjacent bedrock should give fundamental information with regards to major activation processes (river sapping, water seeping, earthquakes, or failure within the frontal hill of bedrock) and their potential consequences.
ISSN: 1435-9529

hal-00411318
https://hal.archives-ouvertes.fr/hal-00411318
DOI : 10.1016/j.enggeo.2008.02.013

Éditeur(s) : Elsevier
Résumé : Vibrio tapetis is the marine bacterium responsible for the brown ring disease (BRD) affecting die manila clam, Ruditapes philippinarum. Identification of V tapelis has been previously performed using biochemical criteria and serological procedures. All of these methods are time consuming and ill-adapted to individual screening. This study describes an oligonucleotidic probe (Vt446) and two PCR primers, deduced from the 16S rDNA sequence, allowing a fast and specific V tapetis identification using dot blot hybridisation and species-specific primed PCR (SSP-PCR). The probe and primers have been tested on 60 strains, including referenced Vibrio sp., Gram negative and positive bacteria, marine bacteria samples and isolated clam bacteria. For all the 19 V tapetis strains, the results of PCR assays consistently corroborated those of the agglutination tests. The detection limit was estimated to be 10(2) CFU ml(-1). The SSP-PCR method has resulted in V tapetis detection in larvae, m diseased clams, and in asymptomatic broodstock clams that later developed BRD. In conclusion, the two SSP-PCR primers were useful for direct and fast identification of V tapetis strains isolated in clams, and are well suited for the screening of individual R. philippilnarum broodstock clams and larvae from the hatchery. (C) 2005 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2006-03 , Vol. 253 , N. 1-4 , P. 25-38

Droits : 2005 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/2006/publication-1692.pdf
DOI:10.1016/j.aquaculture.2005.03.047
http://archimer.ifremer.fr/doc/00000/1692/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Peridotite xenoliths with a broad range of textures provides evidence for consistent microstructural evolution in a vertical transect of the shallow lithospheric mantle (35?55 km depth) beneath the Persani Mountains, SE Carpathians, Romania, due to ongoing plate convergence in the Carpathian Arc nearby. The recrystallized grain size, crystal preferred orientations strength, and resulting seismic anisotropy vary continuously and display a strong correlation to equilibrium temperatures, suggesting a continuous change in deformation conditions with depth. The shallowmost xenoliths have microstructures typical of high stress deformation, marked by strong recrystallization to fine grain sizes, which results in weak crystal preferred orientations and anisotropy. The deepest xenoliths have coarse-grained porphyroclastic microstructures and strong crystal preferred orientations. Replacive orthopyroxene structures, consuming olivine, and high H2O concentrations in the pyroxenes are observed in some xenoliths indicating limited percolation of fluids or volatile-rich melts. Despite the high stress deformation and high H2O contents in some of the studied xenoliths, analysis of olivine crystallographic orientations indicates that [100] slip systems, rather than ?wet? [001] accommodate most of the deformation in all samples. Seismic anisotropy estimated from the measured olivine and pyroxene crystal preferred orientations suggests that the strike-parallel fast SKS polarization directions and ~ 1 s delay times measured in the SE Carpathians are likely the consequence of convergence-driven belt-parallel flow in the lithospheric mantle.
ISSN: 0012-821X

hal-00317303
https://hal.archives-ouvertes.fr/hal-00317303
DOI : 10.1016/J.EPSL.2008.04.035

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The Sivas Basin, located in the Central Anatolian Plateau of Turkey, is a foreland basin that records a complex interaction between sedimentation, salt tectonics and regional shortening during the Oligo-Miocene leading to the formation of numerous mini-basins. The Oligocene sedimentary infill of the mini-basins consists of a thick continental succession, the Karayün Formation, comprising a vertical succession of three main sub-environments: (i) playa-lake, (ii) fluvial braided, and (iii) saline lacustrine. These sub-environments are seen as forming a large Distributive Fluvial System (DFS) modified through time as a function of sediment supply and accommodation related to regional changes in climate and tectonic regime. Within neighbouring mini-basins and despite a similar vertical stratigraphic succession, subtle variations in facies assemblages and thickness are observed in stratigraphic units of equivalent age, thus demonstrating the local control exerted by halokinesis. Stratigraphic and stratal patterns reveal in great detail the complex interaction between salt tectonics and sedimentation including different types of halokinetic structures such as hooks, wedges and halokinetic folds. The regional variations of accommodation/sediment supply led to coeval changes in the architectural patterns recorded in the mini-basins. The type of accommodation regime produces several changes in the sedimentary record: (i) a regime dominated by regional accommodation limits the impact of halokinesis, which is recorded as very small variations in stratigraphic thickness and facies distribution within and between mini-basins; (ii) a regime dominated by localized salt-induced accommodation linked to the subsidence of each individual mini-basin enhances the facies heterogeneity within the DFS, causing sharp changes in stratigraphic thickness and facies assemblages within and between mini-basins.
ISSN: 0950-091X

hal-01685659
https://hal.archives-ouvertes.fr/hal-01685659
DOI : 10.1111/bre.12171