Éditeur(s) : Interciencia
Résumé : Zooplankton abundance, biomass and composition were evaluated in various temporal scales in a seasonal coastal upwelling system at Margarita Island, Venezuela. Scales of temporal variation include weeks, months and seasons (relaxation, upwelling and transition). Seasons were delimitated by upwelling index and sea temperature. The sampling period comprise Sept/2002 - July/2003. Zooplankton samplings were made by horizontal trawls (1-10m depth), using 200,mu m nets, 2-6km from the coastal margin. Total abundance show important variation at week scales, with different patterns between locations, while seasonal differences of abundance are marginal. Biomass only shows seasonal variation due significant reduction in the transition season. Zooplankton assemblages show changes at scale of weeks, with different local patterns, and seasonal changes. Changes in assemblage between the relaxation and upwelling seasons include reduction (during upwelling) of abundance in copepods, cladocerans, salpidae, chaetognates, fish and crustacea larvae. Except by cirripedia larvae, those were important in the upwelling assemblages. Transition shows high variation, with reduction of biomass and assemblage composition similar to upwelling, except by an isolated event. Small scale variation in the zooplankton could be related to physical processes at small scales, eg. turbulence, local circulation, small eddies and filaments, and biological response. Additional sources of nutrient input, eg. riverine input and internal waves, could support local plankton productivity and abundance during relaxation. Detection of high variation in zooplankton abundance and composition at small scales, with local interaction, bring a new light over zooplankton estimation in time series in this system.
La abundancia, la biomasa y la composición del zooplancton costero fueron analizadas a varias escalas temporales en un área afectada por surgencia costera estacional (Isla de Margarita, Venezuela); considerando para ello escalas de semanas, meses y periodos, así como la variación local. La estimación del zooplancton fue realizada a partir de arrastres horizontales (1-10m de profundidad) utilizando redes de 200μ entre 2 y 6 km de la línea de costa, entre set/2002 y jul/2003. La abundancia total presentó alta variabilidad a escala de semanas, con patrones diferentes entre localidades, mientras que la diferencia entre periodos es marginal. La biomasa únicamente mostró variación a escala de periodos por una disminución durante el periodo de transición. La composición presentó fluctuaciones a escalas temporales pequeñas, con patrones de variación diferentes localmente, así como a escala de periodos. Los cambios en composición entre el periodo de relajación y el de surgencia incluyen disminución en la abundancia de copépodos, cladóceros, salpas, quetognatos, larvas de peces y crustáceos; excepto por las larvas de cirrípedos que forman un componente importante durante la surgencia. Se postula que procesos físicos a pequeña escala, como la turbulencia, la circulación local o la formación de pequeños giros o filamentos, y los procesos biológicos, condicionan esta elevada variabilidad a escalas pequeñas. La existencia de fuentes de enriquecimiento adicionales como aportes de ríos y ondas internas pudiera condicionar la presencia de elevada abundancia y biomasa, en especial durante periodos de relajación. Los cambios en composición resaltan la importancia del aporte de merozooplancton costero. Palabras clave / Biomasa / Escalas Temporales / Surgencia / Venezuela / Zooplancton Costero /
Interciencia (0378-1844) (Interciencia), 2014-02 , Vol. 39 , N. 2 , P. 122-128

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00187/29851/28297.pdf
http://archimer.ifremer.fr/doc/00187/29851/

Éditeur(s) : HAL CCSD National Research Council Canada
Résumé : International audience
Spadix temperature was measured in three species of Philodendron: P. acutatum, P. pedatum and P.solimoesense. These species showed two different patterns of spadix temperature during their flowering cycle.In P. acutatum and P. pedatum (subgenus Philodendron), the spadix warmed up twice during the beginning ofeach flowering night with a temperature not significantly different from that of ambient air between the twopeaks. In P. solimoesense (subgenus Meconostigma), the spadix temperature rose up to 14oC above that ofambient air during the first night, then it progressively cooled down but remained 3-6oC above ambient airtemperature. We propose that the heat production and the spadix temperature patterns observed may reflectdifferent physiological processes and have a taxonomic significance in the genus Philodendron.
ISSN: 0008-4026

hal-01202714
https://hal.archives-ouvertes.fr/hal-01202714

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
BACKGROUND: Dengue fever is the most important arboviral infection that affects humans, particularly in tropical and subtropical regions. Here, we provide the first comprehensive overview of the severity of dengue epidemics in French Guiana. METHODOLOGY/PRINCIPAL FINDINGS: We monitored hospitalized cases between 2008 and 2013. Detailed clinical features and biological parameters were collected on a daily basis from all cases. Among the 1,356 cases, 216 (16%) were classified according to the WHO 2009 classification as dengue without warning signs (WS), 926 (68%) were classified as dengue with WS and 214 (16%) were classified as severe dengue. The severity rates were similar between the three major epidemics that occurred during the study period, whereas the hospitalization rate was highest in 2013. Fluid accumulation, aspartate aminotransferase (ASAT) counts>193 IU/L and platelet counts<75,000 cells/mm3 were associated with dengue severity. CONCLUSIONS/SIGNIFICANCE: Our findings provide a recent epidemiological description of the severity of dengue epidemics in French Guiana. These results highlight the potential impacts and consequences of implementing the WHO 2009 classification on hospital activity. Future studies should include virological and immunological investigations of well-documented serum samples.
ISSN: 1932-6203

hal-01477201
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01477201
DOI : 10.1371/journal.pone.0172267
PUBMED : 28196111

Éditeur(s) : HAL CCSD
Résumé : Understanding of the mechanisms driving diversification of species is a significant way to improve the management of ecosystems, predict the impacts of climate change and understand the actual and past biodiversity level. The aim of this thesis is to understand and comprehend genetic mechanisms behind the diversification of species in the presence of gene flow. This thesis is focused on the biological model Symphonia globulifera, which presents two ecotypes: the S.globulifera, specialist of seasonally flooded lowlands and S.sp1, specialist of terra firme. These two ecotypes show low genetic differentiation, despite the presence of two apparent phenotypes. A first part of this thesis was to test the presence of local adaptation of this using reciprocal transplant experiment gardens, allowing the understanding of the ecotypes distributions in their natural habitats. Then, this local adaptation in the presence of gene flow, directed me to the regulation of gene methylation in order to see the role this brand of epigenetics can have in the divergence of the ecotypes. In a third part of the thesis, new generation sequencing of the transcriptome ecotypes in reciprocal gardens transplantations allowed me to show the evidence of gene regulation to differentiate the ecotypes. This work thesis is based on phenotype records data, AFLP genotyping and high-throughput sequencing of the transcriptome, in order to show the important value of gene regulation in the divergence of the locally adapted ecotypes, and a weak role of DNA methylation in the establishment of local adaptation.
Connaitre et appréhender les mécanismes de la diversification des espèces est important pour la gestion des écosystèmes, la prévision des impacts des changements climatiques et la compréhension de la biodiversité actuelle et passée. Le but de cette thèse est de comprendre et de déceler les mécanismes génétiques à l’origine de la diversification des espèces en présence de flux de gènes. Cette thèse se focalise sur le modèle biologique Symphonia globulifera, qui compte deux écotypes : le S.globulifera spécialiste de la terra firme et le S.sp1, spécialiste des bas-fonds. Ces deux écotypes montrent une faible différenciation génétique, malgré la présence de deux phénotypes différents.Une première étape a été de mettre en évidence la présence d’une adaptation locale au sein de cette espèce, par le biais d’une expérimentation de jardins de transplantation réciproques, permettant d’expliquer la répartition des écotypes dans leur habitat naturel. Ensuite, dans le but d’identifier les mécanismes sous-jacent à cette adaptation locale, j’ai testé l’hypothèse que la méthylation des gènes pourrait être une marque de l’épigénétique contribuant à la divergence des écotypes, par l’utilisation d’enzyme sensibles à la méthylation dans un protocole de génotypage AFLP. Enfin, un séquençage haut-débit du transcriptome des écotypes en jardins de transplantation réciproques m’a permis de mettre en évidence une expression différentielle des gènes entre les écotypes, qui pourrait expliquer les différences phénotypiques observées entre les écotypes malgré une faible différentiation génétique. Ces travaux de thèse s’appuie, ainsi, sur des données de traits phénotypiques, de génotypage AFLP et de séquençage à haut débit du transcriptome pour montrer la valeur importante de la régulation des gènes dans la divergence des écotypes adaptés localement, et un faible rôle de la méthylation de l’ADN dans l’établissement cette adaptation locale.
https://tel.archives-ouvertes.fr/tel-01405400

NNT : 2015YANE0005
tel-01405400
https://tel.archives-ouvertes.fr/tel-01405400
https://tel.archives-ouvertes.fr/tel-01405400/document
https://tel.archives-ouvertes.fr/tel-01405400/file/these_-_tinaut.pdf

Éditeur(s) : Elsevier Science Bv
Résumé : A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the NorthWest African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the residence time of water masses resulting in a low natural Cd-uptake by plankton communities while anthropogenic Cd-uptake is high. As expected, the situation is reversed in the Senegalo-Mauritanian upwelling where natural Cd-uptake is higher than anthropogenic Cd-uptake. Based upon an estimate of Cd sources, our modeling study shows, unexpectedly, that the anthropogenic signal of potential Cd-bioaccumulation in the Moroccan upwelling is of the same order of magnitude as the natural signal mainly present in the Senegalo-Mauritanian upwelling region. A comparison with observed Cd levels in mollusk and fishes, which shows overall agreement with our simulations, is confirming our estimates.
Science Of The Total Environment (0048-9697) (Elsevier Science Bv), 2015-02 , Vol. 505 , P. 870-888

Droits : 2014 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00252/36310/35200.pdf
DOI:10.1016/j.scitotenv.2014.10.045
http://archimer.ifremer.fr/doc/00252/36310/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Isotopic fractionation of tritium is a highly relevant issue in radiation protection and requires certain radioecological considerations. Sound evaluation of this factor is indeed necessary to determine whether environmental compartments are enriched/depleted in tritium or if tritium is, on the contrary, isotopically well-distributed in a given system. The ubiquity of tritium and the standard analytical methods used to assay it may induce biases in both the measurement and the signification that is accorded to the so-called fractionation: based on an exhaustive review of the literature, we show how, sometimes large deviations may appear. It is shown that when comparing the non-exchangeable fraction of organically bound tritium (neOBT) to another fraction of tritium (e.g. tritiated water) the preparation of samples and the measurement of neOBT reported frequently led to underestimation of the ratio of tritium to hydrogen (T/H) in the non-exchangeable compartment by a factor of 5 % to 50 %. In the present study, corrections are proposed for most of the biological matrices studied so far. Nevertheless, the values of isotopic fractionation reported in the literature remain difficult to compare with each other, especially since the physical quantities and units often vary between authors. Some improvements are proposed to better define what should encompass the concepts of exchangeable and non-exchangeable fractions.
ISSN: 0160-4120

hal-01117744
https://hal.archives-ouvertes.fr/hal-01117744
https://hal.archives-ouvertes.fr/hal-01117744/document
https://hal.archives-ouvertes.fr/hal-01117744/file/Article%20review%20discrimination%20isotopique-envoy%C3%A9.pdf
DOI : 10.1016/j.envint.2013.12.020

Éditeur(s) : Elsevier
Résumé : Sediment cores acquired in 2004 off the Rhone prodelta show consistent anomalous methane concentrations of up to 87,440 ppm. Methane compositional and isotopic data support a biogenic origin, although there are a few sites that show strongly depleted delta C-13 values (-53%o PDB) suggesting a mixed source for the gas (biogenic and thermogenic). Anomalous methane concentrations (samples with more than 90 ppm) are discussed and integrated with organic carbon data, sedimentary rates and ADCP profiles. Highest gas concentrations were found directly off the river mouth (20-40 m water depth) and where the IFREMER models point to the thickest accumulation (> 2 m) in response to the Rhone flood event. In areas unaffected by the high flux of organic matter and rapid/thick flood deposition, or in between flood events, the conditions for methanogenesis and gas accumulation have not been met; in these areas, the physical and biological reworking of the surficial sediment may effectively oxidize and mineralize organic matter and limit bacterial methanogenesis in the sub-surface. We propose that in the Rhone prodelta flood deposits deliver significant amounts of terrigenous organic matter that can be rapidly buried, effectively removing this organic matter from aerobic oxidation and biological uptake and leading to the potential for methanogenesis with burial.
Marine Geology (0025-3227) (Elsevier), 2006-12 , Vol. 234 , N. 1-4 , P. 215-231

Droits : 2006 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/2006/publication-2396.pdf
DOI:10.1016/j.margeo.2006.09.005
http://archimer.ifremer.fr/doc/00000/2396/

Résumé : After a period of rapid development of the sites (an increase in both reared surface area and production), tropical shrimp aquaculture is currently being faced with critical problems due to economical and ecological constraints. In many countries with favourable conditions for shrimp aquaculture such as indonesia or Vietnam, sites are often badly selected and/or over-exploited. This conducts to sorne extent to decreases or collapses in the production due to the difficulty in predicting the maximum production capacity of the sites. Furthermore, it appears that production sustainability depends on many factors among which socio-economy and ecolo gy are of prime importance. The STD3 project titled « Assessment of tropical shrimp aquaculture impact on the environment in tropical countries using hydrobiology, ecology and remote sensing as helping tools for diagnosis )) was initiated in 1994, with the aim to study the sustainability of marine shrimp aquaculture in tropical areas, main! y Indonesia and Vietnam, through the following tasks: (i) improve site selection and study the impact of aquaculture on marine environments presenting a variable sensitivity to organic sewage, (ii) analyse the socio-economical aspects and profitability of the aquaculture industry and of common resources (iii) use remote sensing and geographical data bases for diagnosis and monitoring of site degradation (iv) reinforce the capacity of Asian scientists through training. Severa! aquaculture sites have been investigated in the Lampung region (South Sumatra, Indonesia), the Mekong delta (Vietnam) and on the West coast of New-Caledonia, providing a large range of typical ecosystems encountered in Asia and in the Pacifie, from coralline sites to coastal plains with mangrove and deltaic areas. The study concerned the spatial structure and seasonal influence of these ecosystems, the temporal variation during the course of the project (3 years) and the relation between the ecological structure and farm productions. Remote sensing provides a synoptic vision over large land expanses. Severa! scenes were processed for landuse mapping using conventional classification techniques. Concerning water quality assessment, a general relation for the Java sea was found between image and field data in terms of total suspended matter. Applying this relation to a new site in Sumatra has provided an initial approach to water type and, together with land use mapping, a preliminary assessment of the suitability of the area to shrimp aquaculture development. Socio-economic research has been focused on the identification ofneeds for collective action, including public policy, in the perspective of shrimp farming sustainability. The main concern is in the regulation of shrimp farming intensification and extensification at the scale of coastal ecosystemic entities in a common property resource management perspective. The common considered here is coastal water quality. Comparing the local development profiles and the institutional grounds for the design and implementation of collective management rules shows that variables such as land tenure system, farm owner socio-economic profile, social homogeneity or heterogeneity of the farmers are key factors to analyse the potential for sustainability. The defmition of water quality and the possible means to ensure its collective management are discussed. The main conclusion is that the economie incentives to farming development are strong but there is no significant difference among traditional, semi-intensive and intensive systems in terms of economie efficiency or wealth distribution. The description of the functioning of the different kinds of ecosystems make it possible to give an advice concerning the positioning of the activity inside the ecosystem, and furthermore to have a reference state in order to determine the impact of the activity on the coastal environnement. This impact can be summarized as an increase in the concentration of total suspended matt€?r, of particulate organic matter and of sulfate reducing bacterias. This organic ma~.er is either issued from rearing activities or from telluric origine, due to mangrove eradication when building the ponds. An evaluation of the relationship existing between productivity and characteristics of each ecosystem bas been conducted by correlating ecological indicators data (concentration of total suspended matter, particulate organic matter, chlorophyll, percentage of pheopigments in total pigments and cyanobacteria and sulfatereducing bacteria in water and sediments) with the average production of the farms. This comparison lead to the compilation of a scale of observed production integrating the range of these environmental parameters with shrimp production levels, bound to facilitate the positioning of shrimp farming in relation with the confmement leve! of each ecosystem. Lastly, ali geographie data originated from the various compartments of the study have been geo-referenced and loaded into a geographical information system. This allows to display any query made on spatial variables and their related statistical data, including the ir variations over the last few years and to reveal patterns and phenomena otherwise not obvious.
Le programme mis en oeuvre par la DRV (Paris, CREMA-L'Houmeau, DELIAO Brest, COP Tahiti, GIE/RA Nouvelle Calédonie), dans le cadre d'un projet européen STD3 «(Sciences et Technique au Service du Développement», en collaboration avec l'Université de Montpellier II, l'Ecole Nationale d'Agronomie de Rennes, l'ITC (Hollande), l'Institut Océanographique de Nha Trang (Vietnam), le BADC de Jepara et le BPPT de Jakarta (Indonésie), avait pour but la mise au point de méthodes permettant d'améliorer la sélection des sites ainsi que le suivi du développement et de l'impact de l'aquaculture des crevettes Péneides en milieu tropical pour éviter la surexploitation. Quatre axes de recherche ont été défmis : a) identifier la nature et quantifier les rejets de déchets issus de ce type d'aquaculture, b) définir les caractéristiques écologiques des écosystèmes susceptibles d'accueillir l'activité aquacole et suivre leur évolution sous l'influence des rejets, c) déterminer l'influence de la gestion des fermes et des ressources (aspects économiques) sur les performances de productivité, d) déterminer la capacité de la télédétection comme outil de diagnostic d'impact à l'échelle de la région, e) mener un programme de formation d'étudiants et jeunes chercheurs Vietnamiens et Indonésiens.

Droits : 1998 Ifremer
http://archimer.ifremer.fr/doc/00132/24357/22357.pdf
http://archimer.ifremer.fr/doc/00132/24357/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Interleukin-27 (IL-27) belongs to the IL-6/IL-12 family of cytokines, associated with different inflammatory diseases and orchestrates its biological activity via common heterodimeric receptor composed of WSX-1 (IL-27Rα) and gp130. The present study was aimed to investigate the regulation of CXCL9, CXCL10, and CXCL11 chemokines in hepatic cells (human LX-2 cell line derived from normal human stellate cells (HSC), primary human hepatocytes, HSC, and HepG2 cells) and concanavalin A (ConA)-induced liver inflammation. We demonstrated that IL-27, but not IL-6, induced/up-regulated CXCR3 ligand genes (CXCL9, CXCL10, and CXCL11; out of 26 selected genes) in a STAT1-dependent manner in hepatic cells in vitro both at transcript and protein levels. In ConA-induced T cell-mediated hepatic model, we showed that soluble IL-27/IFNγ was elevated following ConA hepatitis in association with increased CXCL9, CXCL10, and CXCL11 expression in the liver. The exogenous IL-27 administration induced CXCR3 ligands in mouse liver at 4 h with any significant effect on recruitment of CXCR3(+) immune cells in the liver. The neutralization of IL-27 during ConA hepatitis differentially modulated (transcript vs protein expression) CXCR3 ligands and IFNγ during ConA-induced hepatitis with down-regulated expression of CXCL9 and CXCL10 at transcript level. The IFNγ, complementary regulated the expression of CXCR3 ligands as their up-regulation during ConA hepatitis, was abolished in IFNγ KO mice. In summary, IL-27 up-regulated the CXCL9, CXCL10, and CXCL11 chemokine expression in hepatic cells. IL-27 regulated CXCR3 ligand expression in IFNγ-dependent manner during acute hepatitis suggesting a complementary role of IL-27 and IFNγ to moderate liver inflammation via regulation of CXCR3 ligands. KEY MESSAGE: IL-27 up-regulated CXCR3 ligand expression in human hepatic cells in vitro. IL-27 up-regulated CXCR3 ligand expression and secretion in ConA hepatitis in vivo. CXCR3 ligand expression was down-regulated by blocking IL-27 or IFNγ deficiency. IL-27 modulated liver injury by regulation of CXCR3 ligands in IFNγ-dependent manner.
ISSN: 0946-2716

hal-01214006
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01214006
DOI : 10.1007/s00109-015-1319-6
PUBMED : 26199110

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Neurogenesis initiates during early development and it continues through later developmental stages and in adult animals to enable expansion, remodeling, and homeostasis of the nervous system. The generation of nerve cells has been analyzed in detail in few bilaterian model organisms, leaving open many questions about the evolution of this process. As the sister group to bilaterians, cnidarians occupy an informative phylogenetic position to address the early evolution of cellular and molecular aspects of neurogenesis and to understand common principles of neural development. Here we review studies in several cnidarian model systems that have revealed significant similarities and interesting differences compared to neurogenesis in bilaterian species, and between different cnidarian taxa. Cnidarian neurogenesis is currently best understood in the sea anemone Nematostella vectensis, where it includes epithelial neural progenitor cells that express transcription factors of the soxB and atonal families. Notch signaling regulates the number of these neural progenitor cells, achaete-scute and dmrt genes are required for their further development and Wnt and BMP signaling appear to be involved in the patterning of the nervous system. In contrast to many vertebrates and Drosophila, cnidarians have a high capacity to generate neurons throughout their lifetime and during regeneration. Utilizing this feature of cnidarian biology will likely allow gaining new insights into the similarities and differences of embryonic and regenerative neurogenesis. The use of different cnidarian model systems and their expanding experimental toolkits will thus continue to provide a better understanding of evolutionary and developmental aspects of nervous system formation.
ISSN: 1759-7692

Droits : http://creativecommons.org/licenses/by-nc/
hal-01405097
http://hal.upmc.fr/hal-01405097
http://hal.upmc.fr/hal-01405097/document
http://hal.upmc.fr/hal-01405097/file/Rentzsch_et_al-2016-Wiley_Interdisciplinary_Reviews__Developmental_Biology.pdf
DOI : 10.1002/wdev.257

Résumé : Nos travaux ont permis d'étudier l'effet combiné de la maturation, du mûrissement et des périodes climatiques, sur le profil des composés bioactifs de la banane Musa Cavendish, issus des French West Indies (FWI). La teneur en polyphénols des bananes 400 Degrés Jour (dj) est restée inchangée, tandis que les bananes 600 et 900 dj ont présenté une augmentation significative de leurs teneurs en polyphénols pendant la maturation (pThe combined influence of maturation, ripening and climate periods on French West Indies (FWI) bananas, Musa Cavendish, bioactive compounds profile was studied. The polyphenol content of the 400 dd bananas remained unchanged, while the 600 and 900 dd bananas exhibited a significant polyphenol increase during ripening (p
http://www.theses.fr/2012AGUY0533

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
BACKGROUND:Dengue fever is the most important arboviral infection that affects humans, particularly in tropical and subtropical regions. Here, we provide the first comprehensive overview of the severity of dengue epidemics in French Guiana.METHODOLOGY/PRINCIPAL FINDINGS:We monitored hospitalized cases between 2008 and 2013. Detailed clinical features and biological parameters were collected on a daily basis from all cases. Among the 1,356 cases, 216 (16%) were classified according to the WHO 2009 classification as dengue without warning signs (WS), 926 (68%) were classified as dengue with WS and 214 (16%) were classified as severe dengue. The severity rates were similar between the three major epidemics that occurred during the study period, whereas the hospitalization rate was highest in 2013. Fluid accumulation, aspartate aminotransferase (ASAT) counts>193 IU/L and platelet counts<75,000 cells/mm3 were associated with dengue severity.CONCLUSIONS/SIGNIFICANCE:Our findings provide a recent epidemiological description of the severity of dengue epidemics in French Guiana. These results highlight the potential impacts and consequences of implementing the WHO 2009 classification on hospital activity. Future studies should include virological and immunological investigations of well-documented serum samples
ISSN: 1932-6203

inserm-01481447
http://www.hal.inserm.fr/inserm-01481447
http://www.hal.inserm.fr/inserm-01481447/document
http://www.hal.inserm.fr/inserm-01481447/file/2017%2C%20Flamand%20-%20Epidemiological%20assessment%20of%20the%20severity%20of%20dengue%20epidemics%20in%20French%20Guiana.pdf
DOI : 10.1371/journal.pone.0172267.t003

Éditeur(s) : Elsevier Science Bv
Résumé : Small-scale fisheries have traditionally received less research effort than large-scale fisheries and are generally under-studied in Europe. In spite of their comparatively low volume of catches and economic importance, small-scale fisheries are socially important and an integral part of the European coastal zone. Considering the high heterogeneity of situations and the paucity of quantitative data, we used an analytical methodology based on the comparative method. We carried out an analysis of small-scale fisheries (SSFs) in Europe based on a selection of nine case studies. Our objective was to obtain a comprehensive description of small-scale fleets covering different areas/fisheries/species, encompassing the diversity and specific conditions under which SSFs operate, in order to demonstrate the ecological and social sustainability of this often overlooked fisheries segment. A common approach formulated so that the case studies could be compared with the case histories of other competing users, required that for each set of criteria – technical, biological, socio-economic, and institutional – a set of relevant items and indicators was established. An analysis of characteristics common to the selected case studies is conducted and an attempt made to extend our comparisons to the whole of the European Union. Our results show that (as compared with large-scale fleets, their main competitor) small-scale fleets: (i) are composed of smaller vessels and, consequently, travel lower distances to fishing grounds, and are more reliant on coastal areas; (ii) have smaller crews (although the global employment figure is similar to that of large-scale fleets in Europe); (iii) use mostly, but not exclusively, passive gears; (iv) use multi-purpose fishing approaches, and can change the fish species they target during the year; (v) have lower extraction rates; (vi) have lower total capital investments (including fishing rights), turnover and costs; and (vii) have lower fuel consumption, making them less sensitive to changing oil prices. Dependence on subsidies is lower (viii). Involvement in fisheries management is variable, conservation and access regulation measures are largely local in origin. For the selected case studies, the most significant competitors are large-scale fleets, and recreational fisheries, but other sources of interaction (water quality, invasive species, etc.) cannot be ignored.
Fisheries Research (0165-7836) (Elsevier Science Bv), 2013-02 , Vol. 140 , P. 1-13

Droits : 2012 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00118/22934/20757.pdf
DOI:10.1016/j.fishres.2012.11.008
http://archimer.ifremer.fr/doc/00118/22934/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Saccharomyces cerevisiae is an established model organism for the molecular analysis of fundamental biological processes. The genomes of numerous strains have been sequenced, and the transcriptome and proteome ofmajor phases during the haploid and diploid yeast life cycle have been determined. However, much less is known about dynamic changes of the proteome when cells switch from mitotic growth to meiotic development. We report a quantitative protein profiling analysis of yeast cell division and differentiation based on mass spectrometry. Information about protein levels was integrated with strand-specific tiling array expression data. We identified a total of 2366 proteins in at least one condition, including 175 proteins showing a statistically significant > 5-fold change across the sample set, and 136 proteins detectable in sporulating but not respiring cells. We correlate protein expression patterns with biological processes and molecular function by Gene Ontology term enrichment, chemoprofiling, transcription interference and the formation of double stranded RNAs by overlapping sense/antisense transcripts. Our work provides initial quantitative insight into protein expression in diploid respiring and differentiating yeast cells. Critically, it associates developmentally regulated induction of antisense long noncoding RNAs and double stranded RNAs with fluctuating protein concentrations during growth and development.
ISSN: 1874-3919

hal-01485858
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01485858
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01485858/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01485858/file/Becker%20et%20al.%20-%20The%20protein%20expression%20landscape%20of%20mitosis%20and%20me.pdf
DOI : 10.1016/j.jprot.2016.12.016

Éditeur(s) : HAL CCSD Linnean Society of London
Résumé : Disentangling the impact of landscape features such as rivers and historical events on dispersal is a challenging but necessary task to gain a comprehensive picture of the evolution of diverse biota such as that found in Amazonia. Adenomera andreae, a small, territorial, terrestrial frog species of the Amazonian forest represents a good model for such studies. We combined cytochrome b sequences with 12 microsatellites to investigate the genetic structure at two contrasted spatial scales in French Guiana: along a similar to 6-km transect, to evaluate dispersal ability, and between paired bank populations along a similar to 65-km stretch of the Approuague river, to test the effect of rivers as barriers to dispersal. We observed significant spatial genetic structure between individuals at a remarkably small geographical scale, and conclude that the species has a restricted dispersal ability that is probably tied to its life-history traits. Mitochondrial and microsatellite data also indicate a high level of differentiation among populations on opposite banks of the river, and, in some cases, among populations on the same riverbank. These results suggest that the observed population structure in A. andreae is the result of restricted dispersal abilities combined with the action of rivers and Quaternary population isolation. Given that Amazonia hosts a great portion of anurans, as well as other small vertebrates, that display life-history traits comparable with A. andreae, we argue that our analyses provide new insights into the complex interactions among evolutionary processes shaping Amazonian biodiversity. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 356373.
ISSN: 0024-4066

hal-01032422
https://hal.archives-ouvertes.fr/hal-01032422
DOI : 10.1111/j.1095-8312.2012.01871.x

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Biofouling increases the operational and economic costs associated with pearl production. As currentprocedures for reducing oyster biofouling can be detrimental to survival and growth and may pollute thesurrounding environment developing alternative, biologically-mediated, methods could potentially in-crease both production and ecological sustainability. With this in mind, the present study investigatednatural cleaning of black-lipped pearl oysters, Pinctada margaritifera, by butterflyfishes (Chaetodon). Thefeeding behaviour of six butterflyfish species was examined at Rangiroa Atoll, French Polynesia: Chae-todon auriga, Chaetodon citrinellus, Chaetodon ephippium, Chaetodon lunulatus, Chaetodon trifascialis andChaetodon ulietensis. All species cleaned the surface of pearl oysters by removing epibionts (from 16% to40% of total biomass), although dietary variation may explain different cleaning efficiencies. Generalistomnivores (C. auriga, C. citrinellus, C. ephippium and C. ulietensis) were the most efficient cleaners (%cleaning range: 26e40% of total biomass). Within this group, C. ephippium removed the most biomass(average of 41%) targeting algae and anemones. However, C. auriga targeted the most diverse range ofepibionts, removing significant amounts of algae, sponges, tunicates, and anemones. These resultssuggest that foraging by butterflyfishes can substantially reduce biofouling on economically-importanttropical bivalves.
ISSN: 0272-7714

hal-01434152
https://hal-univ-perp.archives-ouvertes.fr/hal-01434152
DOI : 10.1016/j.ecss.2016.04.001

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
The bivalve Codakia orbicularis, hosting sulfur-oxidizing gill endosymbionts, was starved (in artificial seawater filtered through a 0.22- m-pore-size membrane) for a long-term experiment (4 months). The effects of starvation were observed using transmission electron microscopy, fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH), and flow cytometry to monitor the anatomical and physiological modifications in the gill organization of the host and in the symbiotic population housed in bacteriocytes. The abundance of the symbiotic population decreased through starvation, with a loss of one-third of the bacterial population each month, as shown by CARD-FISH. At the same time, flow cytometry revealed significant changes in the physiology of symbiotic cells, with a decrease in cell size and modifications to the nucleic acid content, while most of the symbionts maintained a high respiratory activity (measured using the 5-cyano-2,3-ditolyl tetrazolium chloride method). Progressively, the number of symbiont subpopulations was reduced, and the subsequent multigenomic state, characteristic of this symbiont in freshly collected clams, turned into one and five equivalent genome copies for the two remaining subpopulations after 3 months. Concomitant structural modifications appeared in the gill organization. Lysosymes became visible in the bacteriocytes, while large symbionts disappeared, and bacteriocytes were gradually replaced by granule cells throughout the entire lateral zone. Those data suggested that host survival under these starvation conditions was linked to symbiont digestion as the main nutritional source.
ISSN: 0099-2240

hal-00750419
https://hal.univ-antilles.fr/hal-00750419
DOI : 10.1128/AEM.02659-08

Éditeur(s) : HAL CCSD Springer Verlag
Résumé :  
The high spatial variability of soil respiration in tropical rainforests is well evaluated, but influences of biotic factors are not clearly understood. This study underlines the influence of tree species characteristics on soil respiration across a 16-monospecific plot design in a tropical plantation of French Guiana. A large variability of soil CO2 fluxes was observed among plots (i.e. 2.8 to 6.8 μmol m−2 s −1 ) with the ranking being constant across seasons. There were no significant relationships between soil respiration and soil moisture or soil temperature, neither spatially, nor seasonally. The variability of soil respiration was mainly explained by quantitative factors such as leaf litterfall and basal area. Surprisingly, no significant relationship was observed between soil respiration and root biomass. However, the influence of substrate quality was revealed by a strong relationship between soil respiration and litterfall P (and litterfall N, to a lesser extent).
ISSN: 0032-079X

hal-01032069
https://hal.archives-ouvertes.fr/hal-01032069
DOI : 10.1007/s11104-008-9866-z

Éditeur(s) : Université de Bretagne Occidentale
Résumé : The stock of Lambi, Strombus gigas (gastropod: strombidae), coastal benthic resource, has been exploited artisanally since the prehistoric period in Martinique. Nowadays, three lines of work exploit the species: free diving, nets (since the middle of the century) and scuba diving since 1985. This report presents the activity of each line of work, surveyed directly from 1986 to 1987: fishing zones and resource allocation, production, effort and performance, detail of catches (by length). The socio economic characteristics of the lambi fishermen are studied. The significant production of leisure fishing is also estimated. The decrease in the production and performance, as well as the lowering of the size of the first catch for about thirty years show that the stock is overexploited. The biological phenomenon of the stock: growth of the shell (length and shell lip), growth in weight, acquiring of sexual maturity, natural mortality are studied. The factors of mortality through fishing are estimated by class of length for the current exploitation regime by pseudo-cohort analysis. If the results confirm that the stock is overexploited, the level of overexploitation of the stock cannot be specified because of the presence of a number of lipped adults not yet too exploited in water deeper than 20 metres. The analysis of the dynamic process of the exploited population indicates two ways to the production of the stock: the forcing of the recruitment and the regulation of the exploitation regime. The lack of economic profitability of the production of juveniles over 30 mm and the difficulties raised by their collection in their natural habitat lead to the rationalization of the exploitation. The production and performance (by recruits) simulations performed for different exploitation regimens indicate that the only two conceivable options are the introduction of a minimum catch size, i.e. lambi with forming lip, and the regulation of the fishing effort. The socio-economic implications of the introduction of the determined management measures show that their applicability level is very low, because of the Martinique fishermen polyactivity, their low socio-economic level and mostly because of the free access to the resource. As a consequence, it is suggested to create new professional structures with a wide jurisdiction, in order to locally manage the marine areas, their use and their resources. (unverified OCR)
Le stock de lambi, Strombus gigas (gastéropode: strombidae), ressource benthique côtière, est exploitée artisanalement depuis l'époque préhistorique en Martinique. Trois métiers exploitent actuellement l'espèce: plongée libre, filets (depuis le milieu du siècle) et plongée en scaphandre autonome depuis 1985. Ce rapport présente l'activité de chaque métier, suivie de 1986 à 1987 par une enquête directe: zones de pêche et allocation de la ressource, productions, efforts et rendements, composition en longueur des captures. Les caractéristiques socioéconomiques des pêcheurs de lambi sont étudiées. La production d'une pêche plaisancière non négligeable est estimée. La diminution de la production, des rendements et l'abaissement de la taille de première capture depuis une trentaine d'années révèlent que le stock est surexploité. Les phénomènes biologiques du stock: croissance de la coquille (longueur et pavillon), croissance en poids, acquisition de la maturité sexuelle, mortalité naturelle sont étudiés. Les coefficients de mortalité par pêche sont estimés par classe de longueur pour le régime d'exploitation actuel par l'analyse de pseudo-cohorte. Si les résultats confirment l'état surexploité du stock, le niveau de surexploitation ne peut être précisé en raison de l'existence d'adultes pavillonnés encore peu exploités sur les fonds de plus de 20 mètres. L'analyse des processus dynamiques de la population exploitée indique deux voies pour restaurer la production du stock: le forçage du recrutement et la régulation du régime d'exploitation. Le manque de rentabilité économique de l'élevage des juvéniles au-delà de 30 mm et les difficultés pour leur collecte dans le milieu naturel conduisent à rechercher la rationalisation de l'exploitation. Les simulations de la production et du rendement par recrue réalisées pour différents régimes d'exploitation indiquent que seule la mise en place d'une taille minimale de capture, i.e le lambi au pavillon en formation, et une régulation de l'effort de pêche sont envisageables. Les implications socio-économiques de la mise en oeuvre des mesures de gestion déterminées montrent que leur niveau d'applicabilité est très faible, en raison de la polyactivité des pêcheurs martiniquais, de leur faible niveau socioéconomique et surtout, du régime de libre accès à la ressource. Aussi, il est proposé la création de nouvelles structures professionnelles aux compétences larges, qui permettraient, pour chacun des bourgs, une gestion locale de l'espace marin, des usages et des ressources. OCR NON CONTRÔLE

Droits : 1993 UBO
http://archimer.ifremer.fr/doc/1993/these-3751.PDF
http://archimer.ifremer.fr/doc/00000/3751/

Éditeur(s) : IEEE
Résumé : Two approaches of ocean color data merging were tested and compared in the North and Equatorial Atlantic Basin: the weighted averaging and the objective analysis. The datasets used were the daily level-3 binned data of chlorophyll-a from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer on the Aqua satellite over the year 2003, which is the first common full year of operation. Since they represent input for both approaches, matchups between the satellite and the in situ data from the SeaWiFS Bio-optical Archive and Storage System and the Atlantic Meridional Transect were first studied to compute a spatial map of the root mean-square error and of the bias. Because of the log distribution of the chlorophyll fields, each approach was applied to untransformed and log-transformed values. The application of the weighted averaging to log-transformed values does not show significant differences in comparison to its application to untransformed values. This is not the case, however, for the objective analysis that gives better results when applied to logtransformed values. Both approaches give combined chlorophyll data of equivalent quality, although the objective analysis could be improved with a better statistical characterization of noise and signal covariance. The main advantage of the objective analysis is its ability to interpolate in space (and time) by taking into account the characteristic scales of chlorophyll-a. As a result, the spatial coverage of the combined data is at least twice as large in the case of objective analysis than weighted averaging. OCR NOT CONTROLLED
IEEE (0196-2892) (IEEE), 2006-11 , Vol. 44 , N. 11 , P. 3436-3451

Droits : 2006 IEEE
http://archimer.ifremer.fr/doc/2006/publication-3631.pdf
DOI:10.1109/TGRS.2006.878441
http://archimer.ifremer.fr/doc/00000/3631/