Éditeur(s) : HAL CCSD
Résumé : National audience
Introduction-objectifsBien que la prise en charge de personnes vivant avec le VIH (PVVIH) s’améliore globalement en Guyane, les disparités régionales et communautaires restent importantes. L’objectif est ici de décrire pour la première fois les caractéristiques épidémiologiques, spatiales et cliniques des PVVIH suivies en zones isolées. Matériels et MéthodesLes données présentées sont issues du suivi clinique réalisé en Centres Délocalisés de Prévention et de Soins (CDPS) de janvier 2014 à novembre 2015. Ces données ont été analysées et comparées aux données des PVVIH suivis dans les 3 centres hospitaliers de Guyane issues du logiciel Nadis®.Résultats 174 PVVIH ont étés pris en charge en CDPS et comparés à 2143 patients suivis sur le littoral. L’évolution du taux annuel de découvertes de séropositivité VIH montre une arrivée plus tardive mais particulièrement active en zones isolées par rapport au littoral, notamment chez les patients d’origine brésilienne (p<0,005). L’âge médian est de 43,8 ans, le sex ratio homme/femme est de 0,98. En zone isolées comme sur le littoral 1/3 des PVVIH sont dépistés tardivement (<200 CD4/mm3). Le succès virologiques après 6 mois de traitement est de 80% vs 88% sur le littoral (p=0,135), la moyenne des derniers CD4 (424 vs 569/mm3) est plus basse que sur le littoral (p<0,005) enfin la charge virale moyenne est plus élevée que sur le littoral (8960 vs 5317 copies /mL) (p<0,005). L’histoplasmose est la première cause d’infection opportuniste retrouvée. La répartition spatiale des patients suivis montre une incidence et prévalence de cas particulièrement élevée dans les villes frontalières charnières que constituent Maripasoula et Saint Georges de l’Oyapock. ConclusionLe caractère particulièrement actif et original de l’épidémie et les indicateurs de suivi moins bons que sur le littoral rappellent l’importance de compléter les moyens de la prise en charge des PVVIH en zones isolées en Guyane.
SFLS 2016 - XVIIème Congrès de la Société française de lutte contre le sida
Montpellier, France

inserm-01475954
http://www.hal.inserm.fr/inserm-01475954
http://www.hal.inserm.fr/inserm-01475954/document
http://www.hal.inserm.fr/inserm-01475954/file/2016%2C%20Mosnier%20-%20Les%20p%C3%A9riph%C3%A9ries%20de%20l%27%C3%A9pid%C3%A9mie%20de%20VIH%20en%20Guyane.pdf

Éditeur(s) : HAL CCSD Royal Society, The
Résumé : There is broad consensus that the diversity of functional traits within species assemblages drives several ecological processes. It is also widely recognized that rare species are the first to become extinct following human-induced disturbances. Surprisingly, however, the functional importance of rare species is still poorly understood, particularly in tropical species-rich assemblages where the majority of species are rare, and the rate of species extinction can be high. Here, we investigated the consequences of local and regional extinctions on the functional structure of species assemblages. We used three extensive datasets (stream fish from the Brazilian Amazon, rainforest trees from French Guiana, and birds from the Australian Wet Tropics) and built an integrative measure of species rarity versus commonness, combining local abundance, geographical range, and habitat breadth. Using different scenarios of species loss, we found a disproportionate impact of rare species extinction for the three groups, with significant reductions in levels of functional richness, specialization, and originality of assemblages, which may severely undermine the integrity of ecological processes. The whole breadth of functional abilities within species assemblages, which is disproportionately supported by rare species, is certainly critical in maintaining ecosystems particularly under the ongoing rapid environmental transitions.
ISSN: 0962-8452

hal-01532639
https://hal.archives-ouvertes.fr/hal-01532639
DOI : 10.1098/rspb.2016.0084
PRODINRA : 384617

Éditeur(s) : HAL CCSD American Association for the Advancement of Science
Résumé : 6 pages
International audience
Large impacts provide a mechanism for resurfacing planets through mixing near-surface rocks with deeper material. Central peaks are formed from the dynamic uplift of rocks during crater formation. As crater size increases, central peaks transition to peak rings. Without samples, debate surrounds the mechanics of peak-ring formation and their depth of origin. Chicxulub is the only known impact structure on Earth with an unequivocal peak ring, but it is buried and only accessible through drilling. Expedition 364 sampled the Chicxulub peak ring, which we found was formed from uplifted, fractured, shocked, felsic basement rocks. The peak-ring rocks are cross-cut by dikes and shear zones and have an unusually low density and seismic velocity. Large impacts therefore generate vertical fluxes and increase porosity in planetary crust.
ISSN: 0036-8075

hal-01399386
https://hal.archives-ouvertes.fr/hal-01399386
PUBMED : 27856906
DOI : 10.1126/science.aah6561

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Coral bleaching events threaten coral reef habitats globally and cause severe declines of local biodiversity and productivity.Related to high sea surface temperatures (SST), bleaching events are expected to increase as a consequenceof future global warming. However, response to climate change is still uncertain as future low-latitude climatic conditionshave no present-day analogue. Sea surface temperatures during the Eocene epoch were warmer than forecastedchanges for the coming century, and distributions of corals during the Eocene may help to inform models forecastingthe future of coral reefs. We coupled contemporary and Eocene coral occurrences with information on their respectiveclimatic conditions to model the thermal niche of coral reefs and its potential response to projected climate change.We found that under the RCP8.5 climate change scenario, the global suitability for coral reefs may increase up to 16%by 2100, mostly due to improved suitability of higher latitudes. In contrast, in its current range, coral reef suitabilitymay decrease up to 46% by 2100. Reduction in thermal suitability will be most severe in biodiversity hotspots, especiallyin the Indo-Australian Archipelago. Our results suggest that many contemporary hotspots for coral reefs,including those that have been refugia in the past, spatially mismatch with future suitable areas for coral reefs posingchallenges to conservation actions under climate change.
ISSN: 1354-1013

hal-01145464
https://hal.archives-ouvertes.fr/hal-01145464
DOI : 10.1111/gcb.12868

Éditeur(s) : HAL CCSD
Résumé : National audience
Les lherzolites de l’étang de Lherz, de Freychinède et de Berqué sontassociées à des métasédiments détritiques contenant des fragments dominantsde manteau et de marbres issus du démantèlement de la couverturemétamorphique mésozoïque de la Zone Nord-Pyrénéenne(ZNP).Les relations originelles entre le socle ultrabasique et ces brèches etmicrobèches ne sont pas toujours accessibles, mais on peut observeren quelques endroits des caractères de contacts sédimentaires (surfaceirrégulière, anfractuosités emplies de microbrèches, remaniement dela lherzolite serpentinisée). La matrice des brèches est invariablementconstituée de grains issus du démantèlement du manteau serpentiniséou non (Ol, CPX, OPX, spinelles, serpentines). Ce cortège ultrabasiqueest associé à des fragments de marbres souvent foliés portant déjàl’empreinte du métamorphisme HT pyrénéen. On trouve également engrande quantité de petites phyllites dont l’origine est soit détritique, soitmétamorphique, par cuisson de la brèche lors d’un stade tardif métamorphismeHT crétacé. Sur le corps de Lherz, la composition des clastes desbrèches évolue entre un pôle 100% carbonaté et un pôle 100% ultrabasique.Par endroit, les carbonates envahissent la péridotite serpentiniséequi prend alors l’aspect typique des ophicalcites. En plusieurs points,à la périphérie immédiate des corps de Lherz et de Freychinède et dansles fentes au sein des lherzolites de Berqué, affleurent les roches à saphirine(voir Monchoux, 1973) faites de lits de minéraux souvent bien triéset de microbrèches dont la composition, surprenante, associe un cortègeultrabasique à un cortège singulier de débris de métaévaporites etde métaophites (phlogopites, anthophyllites, enstatites, hornblendes,...).La mise à nu du manteau dans la ZNP au Crétacé s’accompagne doncdu démantèlement de toute la couverture métamorphique prérift, depuisle Trias jusqu’au Crétacé. Cette contrainte est intégrée dans le modèled’exhumation proposé pour cette partie de la ZNP. Ce modèle tente derendre compte également de la présence au sein du corps principal desbrèches de Lherz (vallon de Fontête Rouge) de rares fragments d’uncroûte continentale à affinité granulitique
24 ème Réunion des sciences de la Terre 2014
Pau, France

insu-01080835
https://hal-insu.archives-ouvertes.fr/insu-01080835

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

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Coral reefs are among the most species-rich and threatened ecosystems on Earth, yet the extent to which human stressors determine species occurrences, compared with biogeography or environmental conditions, remains largely unknown. With ever-increasing human-mediated disturbances on these ecosystems, an important question is not only how many species can inhabit local communities, but also which biological traits determine species that can persist (or not) above particular disturbance thresholds. Here we show that human pressure and seasonal climate variability are disproportionately and negatively associated with the occurrence of large-bodied and geographically small-ranging fishes within local coral reef communities. These species are 67% less likely to occur where human impact and temperature seasonality exceed critical thresholds, such as in the marine biodiversity hotspot: the Coral Triangle. Our results identify the most sensitive species and critical thresholds of human and climatic stressors, providing opportunity for targeted conservation intervention to prevent local extinctions.
ISSN: 2041-1723

hal-01282870
https://hal-univ-perp.archives-ouvertes.fr/hal-01282870
https://hal-univ-perp.archives-ouvertes.fr/hal-01282870/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01282870/file/ncomms10491.pdf
DOI : 10.1038/ncomms10491

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Resolving the early diversification of animal lineages has proven difficult, even using genome-scale datasets. Several phylogenomic studies have supported the classical scenario in which sponges (Porifera) are the sister group to all other animals (''Porifera-sister''3 hypothesis), consistent with a single origin of the gut, nerve cells, and muscle cells in the stem lineage of eumetazoans (bilaterians + ctenophores + cnidarians). In contrast, several other studies have recovered an alternative topology in which ctenophores are the sister group to all other animals (including sponges). The ``Ctenophora-sister'' hypothesis implies that eumetazoan-specific traits, such as neurons and muscle cells, either evolved once along the metazoan stem lineage and were then lost in sponges and placozoans or evolved at least twice independently in Ctenophora and in Cnidaria + Bilateria. Here, we report on our reconstruction of deep metazoan relationships using a 1,719-gene dataset with dense taxonomic sampling of non-bilaterian animals that was assembled using a semi-automated procedure, designed to reduce known error sources. Our dataset outperforms previous metazoan gene superalignments in terms of data quality and quantity. Analyses with a best-fitting site-heterogeneous evolutionary model provide strong statistical support for placing sponges as the sister-group to all other metazoans, with ctenophores emerging as the second-earliest branching animal lineage. Only those methodological settings that exacerbated long-branch attraction artifacts yielded Ctenophora-sister. These results show that methodological issues must be carefully addressed to tackle difficult phylogenetic questions and pave the road to a better understanding of how fundamental features of animal body plans have emerged.
ISSN: 0960-9822

hal-01681528
https://hal.archives-ouvertes.fr/hal-01681528
DOI : 10.1016/j.cub.2017.02.031

Éditeur(s) : HAL CCSD
Résumé : International audience
Up-to-date estimates of the health outcomes of preterm children are needed for assessing perinatal care, informing parents, making decisions about care, and providing evidence for clinical guidelines. To determine survival and neonatal morbidity of infants born from 22 through 34 completed weeks' gestation in France in 2011 and compare these outcomes with a comparable cohort in 1997. The EPIPAGE-2 study is a national, prospective, population-based cohort study conducted in all maternity and neonatal units in France in 2011. A total of 2205 births (stillbirths and live births) and terminations of pregnancy at 22 through 26 weeks' gestation, 3257 at 27 through 31 weeks, and 1234 at 32 through 34 weeks were studied. Cohort data were collected from January 1 through December 31, 1997, and from March 28 through December 31, 2011. Analyses for 1997 were run for the entire year and then separately for April to December; the rates for survival and morbidities did not differ. Data are therefore presented for the whole year in 1997 and the 8-month and 6-month periods in 2011. Survival to discharge and survival without any of the following adverse outcomes: grade III or IV intraventricular hemorrhage, cystic periventricular leukomalacia, severe bronchopulmonary dysplasia, retinopathy of prematurity (stage 3 or higher), or necrotizing enterocolitis (stages 2-3). A total of 0.7% of infants born before 24 weeks' gestation survived to discharge: 31.2% of those born at 24 weeks, 59.1% at 25 weeks, and 75.3% at 26 weeks. Survival rates were 93.6% at 27 through 31 weeks and 98.9% at 32 through 34 weeks. Infants discharged home without severe neonatal morbidity represented 0% at 23 weeks, 11.6% at 24 weeks, 30.0% at 25 weeks, 47.5% at 26 weeks, 81.3% at 27 through 31 weeks, and 96.8% at 32 through 34 weeks. Compared with 1997, the proportion of infants surviving without severe morbidity in 2011 increased by 14.4% (P < .001) at 25 through 29 weeks and 6% (P < .001) at 30 through 31 weeks but did not change appreciably for those born at less than 25 weeks. The rates of antenatal corticosteroid use, induced preterm deliveries, cesarean deliveries, and surfactant use increased significantly in all gestational-age groups, except at 22 through 23 weeks. The substantial improvement in survival in France for newborns born at 25 through 31 weeks' gestation was accompanied by an important reduction in severe morbidity, but survival remained rare before 25 weeks. Although improvement in survival at extremely low gestational age may be possible, its effect on long-term outcomes requires further studies. The long-term results of the EPIPAGE-2 study will be informative in this regard.
ISSN: 2168-6211

hal-01258705
http://hal.univ-brest.fr/hal-01258705
PUBMED : 25621457
DOI : 10.1001/jamapediatrics.2014.3351

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Although coral reefs support the largest concentrations of marine biodiversity worldwide, the extent to which the global system of marine-protected areas (MPAs) represents individual species and the breadth of evolutionary history across the Tree of Life has never been quantified. Here we show that only 5.7% of scleractinian coral species and 21.7% of labrid fish species reach the minimum protection target of 10% of their geographic ranges within MPAs. We also estimate that the current global MPA system secures only 1.7% of the Tree of Life for corals, and 17.6% for fishes. Regionally, the Atlantic and Eastern Pacific show the greatest deficit of protection for corals while for fishes this deficit is located primarily in the Western Indian Ocean and in the Central Pacific. Our results call for a global coordinated expansion of current conservation efforts to fully secure the Tree of Life on coral reefs.
ISSN: 2041-1723

hal-01282920
https://hal-univ-perp.archives-ouvertes.fr/hal-01282920
https://hal-univ-perp.archives-ouvertes.fr/hal-01282920/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01282920/file/ncomms10359.pdf
DOI : 10.1038/ncomms10359