Éditeur(s) : INRA : Institut National de la Recherche Agronomique Université des Antilles. Service commun de la documentation
Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS
Description : Loss of agrodiversity mediated by varietal legacy is an important concern, translating as crop species being at risk for genetic erosion, while loss of genetic resources may deplete material available for future breeding strategies. We explored varietal dynamics in the Guadeloupean agricultural yam system. Interviewing farmers about the varieties cultivated in the past compared to their current varieties demonstrated that no dramatic loss of varieties occurred in the two to three latest decades, and changes in variety frequency mostly affected former widespread varieties while frequency of uncommon varieties demonstrated some stability in cultivation frequency. Varietal dynamics nevertheless reflected strong sub-regional trends, and socio-economic impacts such as age of producers or in farm crop diversity. Recurrent epidemics of anthracnose since its historical start in the 70s did not change varietal turnover too strongly, but resulted into transition from Dioscorea alata to less susceptible species or into a decrease of yam cultivation especially for farmers with financial dissatisfaction. La perte d'agrodiversité négociée par le legs variétal est un souci important, traduisant comme espèces de culture étant en danger pour l'érosion génétique, alors que la disparition des ressources génétiques peut épuiser le matériel disponible pour de futures stratégies d'élevage. Nous avons exploré la dynamique variétale dans le système agricole d'igname en Guadeloupe. Les agriculteurs enquêtés au sujet des variétés cultivées dans le passé comparé à leurs variétés actuelles ont démontré qu'aucune perte dramatique de variétés ne s'est produite pendant les deux à trois dernières décennies, et les changements de la fréquence de variété ont en grande partie affecté d'anciennes variétés répandues tandis que la fréquence des variétés rares démontrait une certaine stabilité dans la fréquence de culture. La dynamique variétale a néanmoins reflété des tendances sous-régionales fortes, et les impacts socio-économiques tels que l'âge des producteurs ou dans la ferme cultivent la diversité. Épidémies récurrentes d'anthracnose puisque son début historique pendant les années 70 n'a pas changé le chiffre d'affaires variétal trop fortement, mais résulté dans la transition de dioscorea alata aux espèces moins susceptibles ou dans une diminution de culture d'igname particulièrement pour des agriculteurs avec mécontentement financier.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16259
V16259

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Geographical distribution of parasite species can provide insights into the evolution and diversity of parasiticcommunities. Biogeography of marine parasites is poorly known, especially because it requires anunderstanding of host-parasite interactions, information that is rare, especially over large spatial scales.Here, we have studied the biogeographical patterns of dactylogyrid parasites of chaetodontids, one of themost well-studied fish families, in the tropical Indo-west Pacific region. Dactylogyrid parasites were collectedfrom gills of 34 butterflyfish species (n = 560) at nine localities within an approximate area of62 million km2. Thirteen dactylogyrid species were identified, with richness ranging from 6 to 12 speciesat individual localities. Most dactylogyrid communities were dominated by Haliotrema angelopterum orHaliotrema aurigae, for which relative abundance was negatively correlated (q = !0.59). Parasite richnessand diversity were highest in French Polynesia and the Great Barrier Reef (Australia) and lowest in Palau.Three biogeographic regions were identified based on dactylogyrid dissimilarities: French Polynesia,characterised by the dominance of H. angelopterum, the western Pacific region dominated by H. aurigae,and Ningaloo Reef (Australia), dominated by Euryhaliotrema berenguelae. Structure of host assemblageswas the main factor explaining the dissimilarity (turnover and nestedness components of the Bray-Curtis dissimilarity and overall Bray-Curtis dissimilarity) of parasite communities between localities,while environment was only significant in the turnover of parasite communities and overall dissimilarity.Spatial structure of localities explained only 10% of the turnover of parasite communities. The interactionof the three factors (host assemblages, environment and spatial structure), however, explained the highestamounts of variance of the dactylogyrid communities, indicating a strong colinearity between the factors.Our findings show that spatial arrangement of chaetodontid dactylogyrids in the tropical Indo-westPacific is primarily characterised by the turnover of the main Haliotrema spp., which is mainly explainedby the structure of host assemblages.
ISSN: 0020-7519

hal-01562156
https://hal-univ-perp.archives-ouvertes.fr/hal-01562156
DOI : 10.1016/j.ijpara.2017.01.006

Éditeur(s) : HAL CCSD Inter-Research
Résumé : International audience
Ecological connectivity is important for effective marine planning and biodiversity conservation. Our aim was to identify factors important in influencing variation in benthic community structure on shallow rocky reefs in 2 regions of the Mediterranean Sea with contrasting oceanographic regimes. We assessed beta (β) diversity at 146 sites in the littoral and shallow sub-littoral from the Adriatic/Ionian Seas (eastern region) and Ligurian/Tyrrhenian Seas (western region) using a null modelling approach to account for variation in species richness. The distance decay relationship between species turnover within each region and geographic distance by sea was determined using generalised linear models. Mantel tests were used to examine correlations between β diversity and connectivity by ocean currents, estimated from Lagrangian dispersal simulations. Variation in β diversity between sites was partitioned according to environmental and spatial components using a distance-based redundancy approach. Species turnover along a gradient of geographic distance was greater by a factor of 3 to 5 in the western region than the eastern region, suggesting lower con-nectivity between sites. β diversity was correlated with connectivity by ocean currents at both depths in the eastern region but not in the western region. The influence of spatial and environmental predictors of β diversity varied considerably between regions, but was similar between depths. Our results highlight the interaction of oceanographic, spatial and environmental processes influencing benthic marine β diversity. Persistent currents in the eastern region may be responsible for lower observed β diversity compared to the western region, where patterns of water circulation are more variable.
Marine Ecology Progress Series

Droits : http://creativecommons.org/licenses/by/
hal-01357935
https://hal-univ-perp.archives-ouvertes.fr/hal-01357935
https://hal-univ-perp.archives-ouvertes.fr/hal-01357935/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01357935/file/m553p001.pdf
DOI : 10.3354/meps11783

Éditeur(s) : HAL CCSD Wiley
Résumé : Unveiling the genetic basis of local adaptation to environmental variation is a major goal in molecular ecology. In rugged landscapes characterized by environmental mosaics, living populations and communities can experience steep ecological gradients over very short geographical distances. In lowland tropical forests, interspecific divergence in edaphic specialization (for seasonally flooded bottomlands and seasonally dry terra firme soils) has been proven by ecological studies on adaptive traits. Some species are nevertheless capable of covering the entire span of the gradient; intraspecific variation for adaptation to contrasting conditions may explain the distribution of such ecological generalists. We investigated whether local divergence happens at small spatial scales in two stands of Eperua falcata (Fabaceae), a widespread tree species of the Guiana Shield. We investigated Single Nucleotide Polymorphisms (SNP) and sequence divergence as well as spatial genetic structure (SGS) at four genes putatively involved in stress response and three genes with unknown function. Significant genetic differentiation was observed among sub-populations within stands, and eight SNP loci showed patterns compatible with disruptive selection. SGS analysis showed genetic turnover along the gradients at three loci, and at least one haplotype was found to be in repulsion with one habitat. Taken together, these results suggest genetic differentiation at small spatial scale in spite of gene flow. We hypothesize that heterogeneous environments may cause molecular divergence, possibly associated to local adaptation in E. falcata.
ISSN: 1010-061X

hal-01032412
https://hal.archives-ouvertes.fr/hal-01032412
DOI : 10.1111/jeb.12069

Résumé : The purpose of this book is to value the economic significance of marine-related activities in France. Each industrial, or public non-commercial, sector is characterized by key figures relating to annual turnover, value added, employment and budget. These figures are accompanied with qualitative information on the recent development, current situation and future perspectives of the sector in terms of markets, employment and technological progress. Public and private R&D is also allowed for. Given the diversity of marine-related activities, this information aims at enabling the reader to assess their importance from a comparative angle. From the sector-based approach it is possible to draw certain conclusions. Notably, commercial activities contributed over 1,3% of the GDP in 1995, such ratio having to be seen as a minimum estimate, worked out on the basis of available data. Seaside-related tourism is by far the most important industry. Most activities experienced a decrease in employment in the first half of the '90s. The estimated annual amount spent on R&D was over FFr 4,5 billion in the recent past period 1995-1996.
Le présent ouvrage a pour but d'évaluer l'importance économique des activités liées à la mer en France. Chaque secteur - industriel marchand, public non marchand - est caractérisé par des chiffres clés portant sur le chiffre d'affaires annuel, la valeur ajoutée, l'emploi, le budget. Ces indicateurs sont accompagnés d'informations qualitatives sur l'évolution récente, la situation actuelle et les perspectives du secteur : marchés, emplois, progrès technique. La R&D publique et privée est également prise en compte. Compte tenu de la diversité des activités liées à la mer, ces informations visent à permettre au lecteur d'en apprécier l'importance sous un angle comparatif. L'approche sectorielle permet de tirer certaines conclusions. Notamment, les activités marchandes ont contribué à plus de 1,3 % du PIB en 1995, un tel ratio devant être compris comme un minimum, calculé à partir des données disponibles. Le tourisme littoral est, de loin, l'activité la plus importante. Dans la plupart des branches, l'emploi baisse dans la première moitié des années 1990. Les dépenses annuelles de R&D sont estimées à plus de 4,5 milliards de francs dans la période récente 1995-1996.

Droits : 1997 Ifremer
http://archimer.ifremer.fr/doc/2001/rapport-1347.pdf
http://archimer.ifremer.fr/doc/00000/1347/

Éditeur(s) : HAL CCSD
Résumé : International audience
Several forthcoming wireless telecommunication systems will use electromagnetic frequencies at millimeter waves (MMWs), and technologies developed around the 60-GHz band will soon know a widespread distribution. Free nerve endings within the skin have been suggested to be the targets of MMW therapy which has been used in the former Soviet Union. So far, no studies have assessed the impact of MMW exposure on neuronal metabolism. Here, we investigated the effects of a 24-h MMW exposure at 60.4 GHz, with an incident power density (IPD) of 5 mW/cm2, on the dopaminergic turnover of NGF-treated PC12 cells. After MMW exposure, both intracellular and extracellular contents of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were studied using high performance liquid chromatography. Impact of exposure on the dopamine transporter (DAT) expression was also assessed by immunocytochemistry. We analyzed the dopamine turnover by assessing the ratio of DOPAC to DA, and measuring DOPAC accumulation in the medium. Neither dopamine turnover nor DAT protein expression level were impacted by MMW exposure. However, extracellular accumulation of DOPAC was found to be slightly increased, but not significantly. This result was related to the thermal effect, and overall, no evidence of non-thermal effects of MMW exposure were observed on dopamine metabolism. © 2017 The Author. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.
Journal of Radiation Research

hal-01580502
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01580502
DOI : 10.1093/jrr/rrx004
PUBMED : 28339776

Éditeur(s) : Natl Shellfisheries Assoc
Résumé : The pearl industry in French Polynesia is based on exploitation of natural stocks of the black-lip pearl oyster (Pinctada margaritifera); it generates an annual turnover of 90 million euros. Improvements in pearl quality need genetic studies to improve the populations. This pearl oyster is a protandric species, where the sex-ratio normally is biased towards males. There is an increasing interest in gender control to find the mechanisms to augment female proportions for management purposes. This review summarizes information on exogenous and endogenous factors regulating gender in this and other bivalves and concludes that P. margaritifera is a protandric hermaphrodite, developing as a male during the first two years and without evidence of an effect from abiotic and biotic factors on gender during this phase. Later, pearl oysters progressively change to females, reaching a sex ratio close to 1:1 in specimens >8 years; at this stage, gender is apparently influenced by environmental parameters, but particularly by stress. Future research should seek to accurately determine the effect of temperature and food on sex ratios. Studies should be performed to characterize genes responsible for expression of gender. The use of hormones is a path that might be explored to influence the gender of pearl oysters.
Journal Of Shellfish Research (0730-8000) (Natl Shellfisheries Assoc), 2011-08 , Vol. 30 , N. 2 , P. 231-240

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00040/15100/12543.pdf
DOI:10.2983/035.030.0206
http://archimer.ifremer.fr/doc/00040/15100/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : L’expansion de la microfinance en Haïti ne semble pas correspondre au développement réel des entreprises financées. Dans cet article, nous analysons dans quelle mesure les conditions de microfinancement déterminent la performance financière des microentreprises emprunteuses. À partir d’un échantillon de soixante-deux microentrepreneurs, nous avons estimé un modèle économétrique qui met en relation le chiffre d’affaires et 6 variables explicatives : taux d’intérêt, montant crédit, délai de remboursement, niveau d’éducation, localisation de l’entreprise, genre-associé. Selon nos résultats, les variables explicatives des résultats financiers des microentrepreneurs sont le délai de remboursement, le genre féminin et la localisation. Il est donc confirmé qu’un délai de remboursement long améliore les résultats financiers des microentreprises bénéficiaires de la microfinance. Par contre, un taux d’intérêt faible ne garantit pas nécessairement de meilleurs résultats financiers puisque le taux d’intérêt n’est pas corrélé significativement au chiffre d’affaires des entreprises.
The expansion of microfinance in Haiti does not seem to correspond to the actual development of microentreprises borrowing from microfinance organizations. In this article, we analyze the extent to which microfinance methodology determine the financial performance of borrowers. Based on a sample of 62 microentrepreneurs, we estimated an econometric model linking turnover and 6 explanatory variables: interest rate, credit amount, repayment period, education level, location, partner’s gender. According to our results, the variables explaining the microentrepreneurs' financial results are: the repayment period, the female gender of partner, and the location. It is therefore confirmed that a long repayment period improves the financial results of microenterprises benefiting from microfinance. On the other hand, a low interest rate does not necessarily guarantee better financial results since the interest rate is not significantly correlated with the turnover of the microentreprises.
Haïti

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.10381
http://journals.openedition.org/etudescaribeennes/10381

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : International audience
Meiotic recombination is required for the segregation of homologous chromosomes and is essential for fertility. In most mammals, the DNA double-strand breaks (DSBs) that initiate meiotic recombination are directed to a subset of genomic loci (hot spots) by sequence-specific binding of the PRDM9 protein. Rapid evolution of the DNA-binding specificity of PRDM9 and gradual erosion of PRDM9-binding sites by gene conversion will alter the recombination landscape over time. To better understand the evolutionary turnover of recombination hot spots and its consequences, we mapped DSB hot spots in four major subspecies of Mus musculus with different Prdm9 alleles and in their F1 hybrids. We found that hot spot erosion governs the preferential usage of some Prdm9 alleles over others in hybrid mice and increases sequence diversity specifically at hot spots that become active in the hybrids. As crossovers are disfavored at such hot spots, we propose that sequence divergence generated by hot spot turnover may create an impediment for recombination in hybrids, potentially leading to reduced fertility and, eventually, speciation
ISSN: 0890-9369

hal-01281480
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281480
DOI : 10.1101/gad.270009.115
PUBMED : 26833728

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Nitrogen (N) transfer from legume trees to associated crops is a key factor for the N economy of low-input agroforestry systems. In this work, we presented a new approach to estimate N transfer based on the 15N content of root exudates and N released by root turnover of the donor plant (Gliricidia sepium) and the temporal change of the 15N content of the receiver plant (Dichanthium aristatum). The study was carried out in greenhouse using two isotopic methods: 15N leaf feeding (LF) and the natural 15N abundance (NA). Measurements of exudate 15N were made at several dates before and after tree pruning. A time-dependent box model was devised to quantify N transfer in time and to make comparisons between the isotopic methods. In NA, although tree roots and exudates presented a similar 15N signature before tree pruning, exudates were strongly depleted in 15N after pruning. In LF, exudates were always depleted in 15N in relation to tree roots. Hence, the current assumption used in N transfer studies concerning the equal 15N/14N distribution in tissues of the donor plant and in its excreted N was not confirmed in our study. Before pruning, N transfer functioned as a two-N-source system (soil N and exudates N) and both isotopic methods provided similar estimates: 11–12% for LF and 10–15% for NA. Calculations performed with the model indicated that N transfer occurred with small or nil fractionation of 15N in exudates. After pruning, there was a third N source associated with N released from tree root turnover. During this period, the isotopic signature of the receiver plant showed a transient state due to the progressive decrease of 15N content of that N source. The amount of N derived from the tree represented 65% of the total N content of the grass at the end of the experiments.
ISSN: 1161-0301

hal-01082183
https://hal-agroparistech.archives-ouvertes.fr/hal-01082183
DOI : 10.1016/j.eja.2007.03.003

Éditeur(s) : Université Bordeaux 1
Résumé : The mercury cycle was explored in the Petit-Saut reservoir / Sinnamary Estuary continuum in French Guiana. Main processes involve (i) photo-induced reduction, (ii) adsorption and desorption at the particle surfaces, (iii) methylating bacterial activity, (iv) precipitation and dissolution of iron oxyhydroxides and sulfides. Sources of mercury to the Petit-Saut reservoir consist of the partly impacted river-tributaries, the atmospheric deposition and the flooded soils or vegetation. Once into the reservoir, divalent mercury undergoes a large spectrum of transformations including speciation and phase changes. We, here, probe these processes and demonstrate that the Petit-Saut reservoir behaves as a privileged site for atmospheric recycling and in situ methylation. At the air / water interface, the mercury evasion exceeds by 50 % the direct atmospheric deposition. The in situ monomethylmercury (MMHg) production mostly occurs at the water-column chemocline and near the benthic interface. It reaches, for the whole reservoir, 8.1 moles yr-1 which corresponds to a 0.06 % d-1 methylation rate. We calculated that the 2003/04 period MMHg outputs from the reservoir to the Sinnamary Estuary averaged 13.5 moles yr-1 while the inputs were 5.4 moles yr-1. The dynamic Sinnamary Estuary is the genuine geochemical reactor of the continuum. There, the divalent mercury undergoes rapid yet profound partitioning among phases, recycling to the atmosphere and methylation processes. Those mostly originate from the long-scale oxygen paucity of the dam discharged waters. The expression of marked redox gradients and the intense organic matter turnover enhance the production of methylable inorganic mercurial species and tend to favor the sulfate reducing bacteria (methylating agents) activity. As a result, the dynamic Sinnamary Estuary exports 60 % more MMHg than it does import: 27 versus 17 moles yr-1. Further at large, in the saline estuary, we determined: (i) a non conservative behavior of dissolved (< 0.2 µm) mercury, (ii) a lowering of the mercury level of particles during mixing with the Amazon plume and (iii) a gradual dilution of the estuarine mercury concentrations by oceanic waters.
La retenue de Petit-Saut et, à l'aval, l'estuaire du Sinnamary sont deux centres d'altération du cycle naturel du mercure. Les processus sont, entre autres, (i) la photoréduction, (ii) la sorption / désorption en surface des particules, (iii) l'activité méthylante des bactéries, (iv) la dissolution / précipitation des oxyhydroxydes et des sulfures de fer. Les sources de mercure vers la retenue sont variées. Elles regroupent, en premier lieu, les affluents (partiellement orpaillés), l'atmosphère, les sols et la végétation ennoyés. Dans la colonne d'eau, les formes divalentes du mercure subissent un train complet de transformations couplant changements de phase et de spéciation. Nos résultats illustrent ces processus et démontrent que la retenue constitue un site privilégié de recyclage vers l'atmosphère et de méthylation. A l'interface air / eau, les exports en mercure de la retenue excèdent de 50 % le dépôt atmosphérique. La production endogène de monométhylmercure (MMHg) a lieu dans des sites particuliers : la chemocline et l'interface benthique. Elle atteint pour l'ensemble de la retenue 8,1 moles a-1 soit un taux de méthylation de 0,06 % j-1. On estime que la retenue exporte vers l'estuaire du Sinnamary 13,5 moles a-1 de MMHg alors qu'elle n'importe que 5,4 moles a-1. L'estuaire dynamique du Sinnamary constitue le véritable réacteur chimique du système fonctionnant en liaison avec celui de la retenue. Le mercure y décrit un cycle rapide aux processus de partition, de recyclage et de méthylation marqués. Ces processus résultent de l'oxygénation incomplète et durable des masses d'eau anoxiques exportées par la retenue de Petit-Saut. L'expression de gradients rédox prononcés conjuguée à un intense recyclage de la matière organique y favorise la production de formes méthylables de mercure ainsi que l'activité des bactéries sulfatoréductrices (agents de la méthylation). C'est pourquoi, l'estuaire dynamique du Sinnamary exporte 60 % plus de MMHg qu'il n'importe : 27 contre 17 moles a-1. Plus en aval, dans l'estuaire salin, nous avons mis en évidence : (i) un comportement non conservatif du mercure dissous, (ii) un appauvrissement du mercure des particules suite au mélange avec le panache de l'Amazone et (iii) une dilution des concentrations par les masses d'eau océaniques.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/these-1508.pdf
http://archimer.ifremer.fr/doc/00000/1508/

Éditeur(s) : EDP Sciences
Résumé : Market position and its evolution were analysed in nine key fish and cephalopod species subject to long-term changes, using the Bay of Biscay fisheries as a case study. Although such long term changes have already been documented, and in some cases shown to be related to the impacts of fishing, changes in the physical environment, or both, relatively little work has been devoted to their potential consequences in economic terms. The nature and extent of these consequences was determined in the present study by looking at the composition of the affected fish production, and the status of different fish products on the markets. We propose a methodology to characterize market position for this set of nine species. The selected species represent a significant part of the gross turnover of French fishing fleets operating in the bay. These species were characterized in terms of their potential sensitivity to fishing and changes in environmental conditions due to global warming. We separated species potentially positively (Engraulis encrasicolus and Lophius budegassa) and negatively affected (Pollachius pollachius and Lophius piscatorius) by warming. Evolution of the value of production of the nine species was then depicted using analysis of macro-economic index (production and potential consumption) and price indices. This revealed the relatively high sensitivity of domestic production to the market crisis that occurred in France in the early 1990s, compared to imported and exported products. The relative position of individual species, with respect to the market and its evolution between 1990 and 2005, was analyzed by multi-factorial analysis. Results derived from the analysis clearly distinguish two groups of species, the first characterized by higher prices (monkfish, Nephrops, sole, seabass) and the second by larger volumes available on the French market (pollack, hake, anchovy, sardine, cuttlefish). We conclude that a major part (69 to 87%) of the gross turnover associated with catches of these fish species in the Bay of Biscay remains potentially unaffected by long-term changes related to climate.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2008-07 , Vol. 21 , N. 3 , P. 307-316

Droits : EDP Sciences, IFREMER, IRD 2008
http://archimer.ifremer.fr/doc/2008/publication-4716.pdf
DOI:10.1051/alr:2008047
http://archimer.ifremer.fr/doc/00000/4716/

Éditeur(s) : HAL CCSD
Résumé : International audience
The functioning of the Manche-à-Eau lagoon and of its mangrove environment with the population of marine fish of Guadeloupe has been studied since 1983, and particularly in the 2000s. This ecosystem supports a stable fish assemblage structure because of its twice a day turnover (14.8%) of marine water. It is a favorable and important site for the reproduction (38%) and growth (46%) of a large number of species. The life cycle of these fish species share, for the most part, an ecophase in the mangrove in brackish water and a marine ecophase outside the lagoon. The mangrove plays a vital role in the retention of continental nutrients. This facilitates the trophic exploitation of vegetal and animal detritus bases by the fish in high population density. The majority of populations present individuals reaching length at least 40% from the known maximum length for the species, although only 38.1% have individuals longer than 300 mm. The mangrove aids in the spawning activity of fish species (41% to 58% of the total abundance) and in the reproductive (maturation, migration) process (58% in density and 70% in biomass). The sedentary species lay their eggs in the mangrove, whereas the temporary species stay there during their trophic ecophase or after a genesic migration from the sea to assure sexual maturation for both sexes in the species.
Proceedings of the 61st Gulf and Caribbean Fisheries Institute
Gosier, Guadeloupe

hal-00755780
https://hal.univ-antilles.fr/hal-00755780
https://hal.univ-antilles.fr/hal-00755780/document
https://hal.univ-antilles.fr/hal-00755780/file/GCFI_61_2009_307-312.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Maternal affective disorders are frequently treated with selective serotonin reuptake inhibitor medications (SSRIs); with up to 10% of women being prescribed these medications during pregnancy. Infant development depends on the early serotonergic environment, which is altered by perinatal SSRIs, raising concern about how these medications affect neural outcomes. While clinical and preclinical research suggests an impact of SSRIs on the developing brain, more research is needed to determine the effects on neuroplasticity, the serotonergic system, and the hypothalamic-pituitary-adrenal axis in neural regions mediating behavior. The current work investigated the effects of the SSRI, fluoxetine, on the serotonergic system in the prefrontal cortex (PFC) during pre-adolescence, and changes to synaptic markers and glucocorticoid receptor density in the cingulate cortex (medial PFC) of pre-adolescent and adult Sprague-Dawley male and female rats. To model aspects of Perinatal Depression and maternal anxiety, pre-gestational maternal stress was used resulting in male and female offspring from 4 groups: 1) control, 2) perinatal fluoxetine exposed, 3) pre-gestational maternal stress exposed, and 4) pre-gestational maternal stress + fluoxetine. Perinatal fluoxetine prevented the effects of maternal stress on 5-HT levels and 5-HT turnover ratio in the PFC of pre-adolescent offspring, particularly in females. However, pre-gestational stress reduced synaptophysin and PSD-95 densities in the cingulate cortex, effects that were more pronounced in males. Interestingly, perinatal fluoxetine exposure reduced GR density in adult males in this same brain area. Together, results show differential effects of perinatal SSRIs and pre-gestational maternal stress on neurodevelopment in the PFC of males and females.
ISSN: 0028-3908

hal-01647158
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647158
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647158/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647158/file/Gemmel%20-%20Perinatal%20fluoxetine%20prevents%20the%20effect.pdf
DOI : 10.1016/j.neuropharm.2017.10.009

Résumé : Les mécanismes à l’origine du maintien de la forte diversité locale des arbres des forêts tropicales humides constituent encore une énigme pour les scientifiques. Cette thèse a pour but d’étudier et de comprendre certains facteurs biotiques et abiotiques qui influencent l’assemblage des communautés des forêts tropicales humides d’Amazonie. A l’aide d’une approche empirique conduite dans les forêts tropicales de Guyane française et du Loreto au Pérou, de nombreuses expériences de terrain ont été mises en place dans le but d’apporter des éléments de réponse sur les mécanismes impliqués dans le maintien de la diversité des communautés d’arbres et d’insectes des forêts amazoniennes. Dans un premier temps, cette thèse permet de souligner l’importance des pressions biotiques exercées sur les communautés d’arbres. En effet, les communautés d’insectes peuvent influencer la composition des communautés d’arbres le long d’un gradient environnemental conduisant à des compromis entre la défense et la croissance. Ces compromis ou tradeoff permettent de maintenir la coexistence des espèces de forêts tropicales humides en favorisant la spécialisation des arbres à leur habitat (Chapitre 1, Annexe 3). Cependant, de nombreux facteurs peuvent engendrer des variations dans les compromis d’allocation exhibés par les plantes, ce qui peut compliquer la validité de ces résultats. Dans ce sens, nous avons souligné l’influence du rôle de la cascade trophique et l’existence chez certaines espèces d’arbres de stratégies d’évitement des insectes (Chapitre 2). Dans un second temps, nous avons montré que les filtres environnementaux et les distances géographiques favorisent un fort turnover de la composition des arthropodes des forêts tropicales (chapitre 3, Annexe 2). Les résultats de cette étude ont des implications fondamentales sur les mécanismes qui expliquent la structuration des communautés d’insectes herbivores. Nous avons souligné l’importance de l’interaction des communautés des insectes herbivores et de leurs plantes associées. De plus, des prédictions sont présentées sur le degré de spécialisation des insectes à leur plante-hôte (Annexe 3), notamment sur les implications possibles dans les compromis d’allocation chez les plantes. Finalement, des perspectives de recherche sont proposées en vue de poursuivre ces travaux de recherche, et notamment des extensions de mes expériences vers d’autres régions tropicales et tempérées et l’intégration de la phylogénie pour comprendre des mécanismes de coévolution entre communautés d’arbres et insectes. Nous proposons également une intégration des résultats de cette thèse dans les stratégies locales et régionales de conservation des forêts tropicales du bassin amazonien.
The mechanisms underlying the maintenance of local diversity of trees in tropical rainforests remain under debate. This dissertation aims to study and understand some biotic and abiotic factors that may influence both tree and insect community assembly in lowland tropical forests of Amazonia. I used an empirical approach to study communities of trees and insects in tropical forests of French Guiana and Peru, to address the extent to which insect herbivores contribute to the turnover of tree species across strong environmental gradients. In Chapter 1, I studied how herbivorous insect communities can influence the composition of tree communities along an environmental gradient by reinforcing tradeoffs between defense and growth that promote habitat specialization (Chapter 1, Appendix 3). The complicated variation in the patterns of growth and defense from this study led me to pursue further observations of an alternative plant defense strategy of time-avoidance of herbivores, which I examined in detail in Chapter 2. I found evidence for coordinated leaf production in some tree species that was consistent with the satiation of herbivores, suggesting that multiple interactions between plants and their herbivores may be responsible for patterns of habitat specialization in trees. In the second part of the dissertation, I examined insect herbivore communities in detail to test for turnover in species composition across geographic and environmental gradients. In Chapter 3, I present evidence for substantial beta-diversity in arthropod communities throughout lowland Amazonian forests. In the discussion I propose research perspectives to complete this research, including the extension of observations to compare tropical and temperate regions and the integration of molecular phylogenetics information to study coevolution of plant lineages and their insect herbivores. I conclude with suggestions for the integration of the results of this thesis in local and regional strategies for the preservation and conservation of tropical forests in the Amazon basin.

http://www.theses.fr/2013AGUY0582/document

Résumé : The document, fifth edition of a collection which has started in 1997, presents a survey of marine-related activities in France. The commercial sector includes exploitation and extraction of marine resources, manufacturing industry, private services. In this new edition, a special effort is devoted to the analysis of maritime ports related industries. The non-commercial sector includes public services, among which the Navy, state services, education, safety, marine and coastal environment protection, marine sciences. Each activity of the commercial sector is described by key figures (turnover, value added, employment). The non-commercial sector includes data on running costs, in particular personnel costs. In addition to indicators, qualitative information is provided on the recent developments and future prospects of industries.
Le document, cinquième édition d'une série lancée en 1997, présente un panorama des activités liées à la mer en France. Le secteur marchand comprend l'exploitation et l'extraction des ressources marines, l'industrie manufacturière, les services privés. Dans cette nouvelle édition, un effort particulier est consacré à l'analyse de l'activité portuaire. Le secteur non marchand est constitué des services publics, dont la Marine nationale, les services de l'État, l'enseignement, la sécurité, la protection de l'environnement littoral et marin, la recherche scientifique. Chaque activité du secteur marchand est décrite par des chiffres-clés (chiffre d'affaires, valeur ajoutée, emploi). Sur le secteur non marchand sont fournies des données de coûts, dont les coûts de personnel. Tous ces indicateurs sont accompagnés d'informations qualitatives sur l'évolution récente et les perspectives des branches d'activité.

Droits : 2004 Ifremer
http://archimer.ifremer.fr/doc/00083/19400/16993.pdf
http://archimer.ifremer.fr/doc/00083/19400/

Éditeur(s) : HAL CCSD Wiley
Résumé : 1. Trade-offs among functional traits reveal major plant strategies that can give insight into species distributions and ecosystem processes. However, current identification of plant strategies lacks the integration of root structural traits together with leaf and stem traits. 2. We examined correlations among 14 traits representing leaf, stem and woody root tissues. Traits were measured on 1084 individuals representing 758 Neotropical tree species, across 13 sites representative of the environmental variation encompassed by three widespread habitats (seasonally flooded, clay terra firme and white-sand forests) at opposite ends of Amazonia (French Guiana and Peru). 3. Woody root traits were closely aligned with stem traits, but not with leaf traits. Altogether leaf, stem and woody root traits delineated two orthogonal axes of functional trade-offs: a first axis defined by leaf traits, corresponding to a leaf economics spectrum, and a second axis defined by covarying stem and woody root traits, corresponding to a wood economics spectrum. These axes remained consistent when accounting for species evolutionary history with phylogenetically independent contrasts. 4. Despite the strong species turnover across sites, the covariation among root and stem structural traits as well as their orthogonality to leaf traits were strongly consistent across habitats and regions. 5. We conclude that root structural traits mirrored stem traits rather than leaf traits in Neotropical trees. Leaf and wood traits define an integrated whole-plant strategy in lowland South American forests that may contribute to a more complete understanding of plant responses to global changes in both correlative and modelling approaches. We suggest further meta-analyses in expanded environmental and geographic zones to determine the generality of this pattern.
ISSN: 0269-8463

hal-01032415
https://hal.archives-ouvertes.fr/hal-01032415
DOI : 10.1111/j.1365-2435.2012.02020.x

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies establishing the demographic and life-history consequences of occupying different reef substrata are rare and no studies have monitored individuals in situ over their lifetime and determined the fate of their offspring. Here, we documented a quasi-turnover and local reproductive success for an entire population of orange clownfish (Amphiprion percula) from Kimbe Island, Papua New Guinea, by taking bi-annual samples of DNA over a 10-yr period (2003–2013). We compared demographic and life-history traits of individuals living on two host anemone species, Heteractis magnifica and Stichodactyla gigantea, including female size, adult continued presence (a proxy for relative longevity range), early post-settlement growth, the number of eggs per clutch and ‘local’ reproductive success (defined for each adult as the number of offspring returning to the natal population). Our results indicate that while the relative longevity of adults was similar on both host anemone species, females living in H. magnifica were larger than females in S. gigantea. However, despite females growing larger and producing more eggs on H. magnifica, we found that local reproductive success was significantly higher for clownfish living in S. gigantea. Life-history traits also exhibited local spatial variation, with higher local reproductive success recorded for adults living on S. gigantea on the eastern side of the island. Our findings support a ‘silver-spoon’ hypothesis that predicts individuals that are fortunate enough to recruit into good habitat and location will be rewarded with higher long-term reproductive success and will make a disproportionate contribution to population renewal.
ISSN: 0722-4028

hal-01357939
https://hal-univ-perp.archives-ouvertes.fr/hal-01357939
DOI : 10.1007/s00338-016-1485-1

Éditeur(s) : HAL CCSD
Résumé : International audience
Despite their dynamic nature, certain chromatin marks must be maintained over the long term. This is particulary true for histone 3 lysine 9 (H3K9) trimethylation, that is involved in the maintenance of healthy differentiated cellular states by preventing inappropriate gene expression, and has been recently identified as the most efficient barrier to cellular reprogramming in nuclear transfer experiments. We propose that the capacity of the enzymes SUV39H1/2 to rebind to a minor fraction of their products, either directly or via HP1α/β, contributes to the solidity of this mark through (i) a positive feedback involved in its establishment by the mutual enforcement of H3K9me3 and SUV39H1/2 and then (ii) a negative feedback sufficient to strongly stabilize H3K9me3 heterochromatin in post-mitotic cells by generating local enzyme concentrations capable of counteracting transient bursts of demethylation. This model does not require direct molecular interactions with adjacent nucleosomes and is favoured by a series of additional mechanisms including (i) the protection of chromatin-bound SUV39H1/2 from the turnovers of soluble proteins, which can explain the uncoupling between the cellular contents in SUV39H1 mRNA and protein; (ii) the cooperative dependence on the local density of the H3K9me3 of HP1α/β-dependent heterochomatin condensation and, dispensably (iii) restricted enzyme exchanges with chromocenters confining the reactive bursts of SUV39H1/2 in heterochromatin. This mechanism illustrates how seemingly static epigenetic states can be firmly maintained by dynamic and reversible modifications. © 2016 Elsevier B.V.
Biochimica et Biophysica Acta - Gene Regulatory Mechanisms

hal-01467548
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467548
DOI : 10.1016/j.bbagrm.2016.11.006
PUBMED : 27876670

Éditeur(s) : HAL CCSD Royal Society, The
Résumé : International audience
Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase.
ISSN: 0962-8452

hal-01239322
https://hal-univ-perp.archives-ouvertes.fr/hal-01239322
DOI : 10.1098/rspb.2015.1311