Éditeur(s) : HAL CCSD
Résumé : Shoreline and upper beach dynamics under extreme events: the KUNSHEN experiment (Wan Tzu Liao barrier, Taiwan)
PARALIA génie civil & génie côtier

hal-00861950
https://hal.archives-ouvertes.fr/hal-00861950

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Serpentinites from subduction environments represent an important sink for fluid-mobile elements. In order to constrain geochemical behavior of fluid-mobile elements hosted by serpentine phases during subduction processes, we carried out a geochemical study (trace elements and Pb isotopes) of a series of serpentinites and cumulates from the accretionary wedge of Greater Caribbean (Cuba and Dominican Republic). The trace element compositions of the primary and alteration-related phases were analyzed in situ using LA-HR-ICP-MS techniques. The studied samples represent parts of the subducted proto-Atlantic oceanic lithosphere, which has experienced low to high grade metamorphism (greenschist to eclogite facies), before being exhumed; a subset of these samples were derived from the mantle wedge. This sampling provides the opportunity to trace the chemical mobility of fluid-mobile elements during prograde metamorphism along a cold geotherm in an oceanic subduction setting.
ISSN: 0009-2541

hal-00720895
https://hal.archives-ouvertes.fr/hal-00720895
DOI : 10.1016/j.chemgeo.2012.04.009

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators: prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests.
PLoS ONE

hal-00913931
https://hal.archives-ouvertes.fr/hal-00913931
https://hal.archives-ouvertes.fr/hal-00913931/document
DOI : 10.1371/journal.pone.0071735
OATAO : 10204

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : Architectural analyses of temperate tree species using a chronological approach suggest that the expression of epicormic branches is closely related to low growth rates in the axes that make up the branching system. Therefore, sole consideration of epicormic criteria may be sufficient to identify trees with low secondary growth levels or with both low primary and secondary growth levels. In a tropical tree such as Dicorynia guianensis (basralocus), where chronological studies are difficult, this relationship could be very useful as an easily accessible indicator of growth potentials. A simple method of architectural tree description was used to characterize the global structure of more than 1650 basralocus trees and to evaluate their growth level. Measurements of simple growth characters [height, basal diameter, internode length of submittal part (top of the main axis of the tree)] and the observation of four structural binary descriptors on the main stem (presence of sequential branches and young epicormic branches, state of the submittal part, global orientation), indicated that epicormic branch formation is clearly related to a decrease in length of the successive growth units of the main stem. Analysis of height vs. diameter ratios among different tree subgroups, with and without epicormic branching, suggested that trees with epicormic branches generally have a low level of secondary growth compared with primary growth.
ISSN: 0305-7364

hal-01032037
https://hal.archives-ouvertes.fr/hal-01032037
DOI : 10.1093/aob/mcg119

Éditeur(s) : HAL CCSD Météo et Climat
Résumé : International audience
D'initiative française, le projet international HyMeX a pour objectif d'améliorer la compréhension du cycle de l'eau en Méditerranée, de sa variabilité, de l'échelle de l'événement météorologique aux échelles saisonnières et interannuelles, et de ses caractéristiques sur une décennie, dans un contexte de changement global. Le projet est motivé par le rôle déterminant des processus de mésoéchelle, couplés entre l'atmosphère, la mer et la terre, sur la variabilité du système climatique et sur le déclenchement d'événements hydrométéorologiques extrêmes (précipitations et inondations, vents forts et convection océanique, canicules et sécheresses). Le projet vise enfin à évaluer les conséquences de ces événements extrêmes sur la vulnérabilité sociale et économique de cette région et sa capacité d'adaptation.
ISSN: 0026-1181

hal-00828758
https://hal.archives-ouvertes.fr/hal-00828758
https://hal.archives-ouvertes.fr/hal-00828758/document
https://hal.archives-ouvertes.fr/hal-00828758/file/meteo_2013_80_23%20%281%29.pdf
DOI : 10.4267/2042/48792

Éditeur(s) : HAL CCSD Coastal Education and Research Foundation, Inc.
Résumé : International audience
Morphodynamics of sandy, macrotidal, embayed beaches is complex because of the numerous physical processes interacting at the same location over a wide range of temporal scales. As most of these processes are controlled by beach morphology, dynamic feedbacks are generally observed between hydro- and morphodynamics. Investigating short-term processes is essential in order to improve long term morphological prediction. A key question is to understand how beach slope reacts to forcing conditions, in particular the response time of the beach profile, how long the transient state lasts. This study deals with the spatial and temporal responses of beach morphology to varying incident conditions. Here we report main observations, preliminary results and on-going investigations on the DYNATREZ1 field campaign, which was conducted in the framework of the National Observation Service Dynalit. Beach profiles are shown to adapt rapidly to forcing conditions, within two days, with more intense variations observed in the high tide swash zone. The presence of infragravity waves and their dissipation on the beach is highlighted. It is likely that the very large variability in beach slope observed over a single neapspring cycle is responsible for the accordingly large variability in wave skewness, asymmetry and breaking processes, and thus in sediment fluxes and morphological changes.
ICS 2016 Sydney
Sydney, Australia

hal-01254465
https://hal.archives-ouvertes.fr/hal-01254465
DOI : 10.2112/SI75-075.1

Éditeur(s) : HAL CCSD
Résumé : International audience
Conférence MISTRALS PAELOMEX
Montpellier, France

hal-01683548
https://hal-univ-tlse2.archives-ouvertes.fr/hal-01683548

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
ISSN: 1935-2727

hal-01447691
https://hal.archives-ouvertes.fr/hal-01447691
DOI : 10.1371/journal.pntd.0005254
PUBMED : 28081120

Éditeur(s) : HAL CCSD Elsevier
Résumé : Understanding the pattern in spatial distribution of soil microbial processes is critical to understand the environmental factors that regulate them as well as to scale up these processes to ecosystem. Soil samples from a I ha tropical rainforest plot (Paracou, French Guiana) were analyzed according a nested sampling approach using different separation distances ranging from 0.4 to 40 m. The variability of substrate induced respiration (SIR) and of denitrification enzyme activity (DEA) was characterized in relation to various soil properties (total C and N contents, NIRS related index of soil organic matter quality, SOMQ and index of tree influence potential, IP). The variability of SIR and DEA was higher than that of environmental properties. The patterns of accumulated variance as a function of distance varied among the soil properties. The variability of SIR and DEA mainly occurred at small (1 m) scale (and at the 10-40 m-scales for SIR), probably reflecting the quality of litter input that results of the influence of local assemblage of different tree species, though changes in the soil N and C contents. Indeed, total soil C and N contents explained the microbial properties at every scale. Coefficients of codispersion showed that neither SOMQ nor IP did correlate with SIR and DEA, and confirmed that total C and N contents explained microbial properties in a scale dependent and complex manner. Such spatial dependency underlines the importance of soil heterogeneity in this tropical forest with implications for sampling strategies when studying the microbial processes and their response to disturbances. (C) 2012 Elsevier B.V. All rights reserved.
ISSN: 0016-7061

hal-01032409
https://hal.archives-ouvertes.fr/hal-01032409
DOI : 10.1016/j.geoderma.2012.12.009

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 Elsevier
Résumé :  
absent
Ecology and management of a neotropical rainforest: lessons drawn from Paracou, a long-term experimental research site in French Guiana

ISBN : 2-84299-455-8
hal-01189214
https://hal.archives-ouvertes.fr/hal-01189214
PRODINRA : 16123

Éditeur(s) : HAL CCSD Le Cherche midi CNRS
Résumé : 192 pages
National audience
https://hal.archives-ouvertes.fr/hal-01118878

ISBN : 978-2-7491-4075-9
hal-01118878
https://hal.archives-ouvertes.fr/hal-01118878

Éditeur(s) : HAL CCSD Wiley
Résumé :
How Quaternary climatic and geological disturbances influenced the composition of Neotropical forests is hotly debated. Rain fall and temperature changes during and/or immediately after the Last Glacial Maximum (LGM) are thought to have strongly affected the geographical distribution and local abundance of tree species. The paucity of the fossil records in Neotropical forests prevents a direct reconstruction of such processes. To describe community-level historical trends in forest composition, we turned therefore to inferential methods based on the reconstruction of past demographic changes. In particular, we modelled the history of rainforests in the Eastern Guiana Shield over a time scale of several thousand generations, through the application of Approximate Bayesian Computation (ABC) and Maximum Likelihood (ML) methods to diversity data at nuclear and chloroplast loci in eight species or subspecies of rainforest trees. Depending on the species and on the method applied, we detected population contraction, expansion or stability, with a general trend in favour of stability or expansion, with changes presumably having occurred during or after the LGM. These findings suggest that Guiana Shield rain forests have globally persisted, while expanding, through the Quaternary, but that different species have experienced different demographic events, with a trend towards the increase in frequency of light-demanding, disturbance-associated species.
ISSN: 0962-1083

hal-01512150
https://hal.archives-ouvertes.fr/hal-01512150
https://hal.archives-ouvertes.fr/hal-01512150/document
https://hal.archives-ouvertes.fr/hal-01512150/file/Barthe_et_al-_%7B0B6A8C5E-DDFF-4C4E-822C-4E7BC22A6C9B%7D.pdf
DOI : 10.1111/mec.13949

Éditeur(s) : HAL CCSD Taylor & Francis (Routledge)
Résumé : International audience
The Maroni basin, an isolated region delineating the border between Suriname and French Guiana has been affected by the human immunodeficiency virus (HIV) epidemic 10 years after coastal French Guiana. However, the rise in HIV prevalence was sharp, exceeding 1% within 10 years. The aim of the present study is to compare, using the first quantitative data from the general population in remote villages, the knowledge, attitudes, and behaviors regarding HIV between Maroon and Amerindian populations, the two most frequent populations living along the Maroni. Data were collected in 2012 using a structured questionnaire among a random sample of 896 individuals residing in the remote villages on the Maroni river. Proportions were compared between the Maroni and the coastal general population, and between Maroon and Amerindian populations. The present study shows significant differences between territories and between communities living on the Maroni river: the multiple sexual partnerships, more common among population living on the Maroni river, were more frequently reported in Maroons than in Amerindians. Condom use was more frequently reported among men on the Maroni river than on the coast, but these findings were reversed for women. Moreover, among people living on the Maroni river, condom use was more frequently reported among Maroons than among Amerindians. Regarding genital factors that may affect transmission, penile implant seemed to have no ethnic boundaries, steam baths seemed specific to Maroon women. The present results should help to improve community-based specific interventions.
ISSN: 0954-0121

hal-01260915
https://hal.archives-ouvertes.fr/hal-01260915
https://hal.archives-ouvertes.fr/hal-01260915/document
https://hal.archives-ouvertes.fr/hal-01260915/file/2015%2C%20Van%20Melle%20-%20Knowledge%2C%20attitudes%2C%20behaviors%2C%20and%20practices%20differences%20regarding%20HIV.pdf
DOI : 10.1080/09540121.2015.1032203

Éditeur(s) : HAL CCSD
Résumé : International audience
o abstract
34th International Conference on Coastal Engineering ICCE2014 in Seoul, Korea

hal-01426584
https://hal.archives-ouvertes.fr/hal-01426584

Éditeur(s) : HAL CCSD Société nationale de protection de la nature (France)
Résumé : International audience
Les plantes qui présentent des structures anatomiques permettant de retenir de l'eau en permanence sont assez répandues en milieu tropical. Si beaucoup sont maintenant cultivées pour être vendues en jardineries, faisant le bonheur des amateurs, elles forment en milieu naturel des écosystèmes aquatiques encore très peu étudiés et renferment une biodiversité que l'on est loin d'avoir recensée. En Amérique centrale et du Sud, les broméliacées-citerne, qui représentent les plus nombreuses et les plus diversifiées de ces " plantes-mares ", permettent à des organismes très variés d'accomplir leur cycle de vie
ISSN: 0011-0477

hal-00849049
https://hal.archives-ouvertes.fr/hal-00849049
https://hal.archives-ouvertes.fr/hal-00849049/document
https://hal.archives-ouvertes.fr/hal-00849049/file/Carrias2013_Des_plantes.pdf

Éditeur(s) : HAL CCSD Coastal Education and Research Foundation (CERF) Coastal Education and Research Foundation
Résumé : International audience
Current profiles
ISSN: 0749-0208

hal-01122783
https://hal.archives-ouvertes.fr/hal-01122783

Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : International audience
[1] This article presents (U-Th)/He thermochronological data from the Longmen Shan belt, eastern Tibet. Located between the Songpan-Garze terrane and the Yangtze craton, this mountain range is one of the steepest margins of the Tibetan Plateau and an important area for the comprehension of the mechanisms that control the dynamics of such plateau borders in terms of spatial distribution of deformation or timing of topographic building. We describe several age-elevation transects and perform forward modeling of our data to derive quantitative information on the exhumation of the range. A major phase of exhumation started at 8–11 Ma, with an average rate of $0.65 mm a À1. Comparison of zircon and apatite ages indicates that the eastern part of the range may have experienced a significant decrease in exhumation since 2–3 Ma. We use the distribution of finite exhumation across the major faults of the area to quantify their dip-slip throw rate over the last 10 Ma. The Beichuan Fault, which was activated during the 2008 Sichuan earthquake, is the major active structure of the Longmen Shan since the late Miocene, with an average thrusting slip rate between 0.4 and 1 mm a À1. Conversely, over the same time period, only minor dip-slip activity occurred on the Wenchuan Fault Zone. This distribution in space and time of exhumation and deformation is discussed and compared to the different proposed models for the geodynamical evolution of the eastern Tibetan margin. It also provides an important long-term perspective to put in context the destructive 2008 Sichuan earthquake that struck the central Longmen Shan.
ISSN: 0278-7407

hal-01577059
https://hal-amu.archives-ouvertes.fr/hal-01577059
https://hal-amu.archives-ouvertes.fr/hal-01577059/document
https://hal-amu.archives-ouvertes.fr/hal-01577059/file/godard2009late.pdf
DOI : 10.1029/2008TC002407

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
Human leishmaniasis are widely spread diseases with different clinical forms caused by about 20 species within the Leishmania genus. Leishmania species identification is relevant for therapeutic management and prognosis, especially for cutaneous and muco-cutaneous forms. Several methods are available to identify Leishmania species from culture, but they have not been standardized for the majority of the currently described species, with the exception of MultiLocus Enzyme Electrophoresis. Moreover, these techniques are expensive, time-consuming and not available in all laboratories. Within the last decade, mass spectrometry (MS) has been adapted for microorganism identification, including Leishmania However, no commercial reference mass spectral database is available. In this study, a reference mass spectral library (MSL) for Leishmania isolates, accessible through a free web-based application (mass spectral identification, MSI), was constructed and tested. It includes mass spectral data for 33 different Leishmania species, including species that infect humans, animals and phlebotomine vectors. Four laboratories on two continents evaluated MSI performance using 268 samples of which 231 were Leishmania strains. All Leishmania strains, but one, were correctly identified at least at the complex level. A risk of species misidentification within the L. donovani, L. guyanensis and L. braziliensis complexes was observed, as already reported with other techniques. The tested application was reliable, with identification results comparable to those obtained with reference methods, but with a more favorable cost-efficiency ratio. This free online identification system relies on a scalable database and can be implemented directly in the user's computers.
ISSN: 0095-1137

hal-01571305
https://hal.archives-ouvertes.fr/hal-01571305
DOI : 10.1128/JCM.00845-17
PUBMED : 28724559

Éditeur(s) : HAL CCSD
http://hal.univ-reunion.fr/hal-01487167

hal-01487167
http://hal.univ-reunion.fr/hal-01487167