Éditeur(s) : HAL CCSD Société géologique de France
Résumé : A study combining very high resolution seismic and sediment core data has been carried out on the Thau lagoon (Mediterranean coast, microtidal setting, SE France) in order to understand more clearly the dynamics and Holocene chronology of its closure through the different stages of its filling. One main seismic unit (U2) has been defined into the infill, above the rocky basement (U0) and a composite unit U1, which is interpreted as remnants of Pleistocene fluvial terraces or/and to early marine Holocene deposits. Unit U2, that reaches locally 9 m in thickness, rests conformably on U1 in the central part of the lagoon and onlaps U0 or U1 close to the edge of the lagoon. It is divided in two sub-units, U2-1 and U2-2. U2-2 rests paraconformably on U2-1 in the central part of the lagoon where the infill is the thickest, while a marked erosional unconformity is observed between U2-1 and U2-2 on topographic highs of the basement and on the seaward edge of the lagoon. A total of seven elementary sequences have been observed in U2-1 and U2-2.;According to core data, U2 consists in a series of mud-dominated sequences, with shell fragments dispersed at the base. The vertical distribution of the fauna into U2-1 and U2-2 reveals a lagoonal environment. However in U2-1, marine species are more abundant in the south of the lagoon. C-14 AMS dating provides three ages: similar to 6000 cal yr B.P. in the lower part of U2-1 on CAL1, 5400 cal yr B.P. just above the boundary between U2-1 and U2-2 on CAL4, similar to 3000 cal yr B.P. in the middle of U2-2 on CAL4.;A scenario to explain the lagoon infill stratigraphy and geometry is proposed. The beginning of the lagoon infill occurred with the initiation of the barrier construction, as soon as the sea-level rise slowed down significantly, i.e. between 7000-6000 yr B.P. The sediment-fill began into the back-barrier system, with a high rate of sedimentation for U2-1, according to the radiocarbon data. At 5400 yr B.P., the barrier is assumed to be totally closed leading to the deposition of the fully lagoonal U2-2 succession. The unconformity between U2-1 and U2-2 is interpreted as the result of a rapid landward retreat of the barrier. This severe retreat could be related to climate forcing and/or brutal change in sediment discharge driven by the Rhone River, which is the main sediment source of the longshore drift. In this scenario, the last sub-unit, U2-2, represents most of the late Holocene infill. In this framework, the elementary sequences observed in U2-2 could be related to high frequency climate changes of about 1000-1500 years periodicity according to C-14 dates.
EISSN: 1777-5817

hal-00486386
https://hal.archives-ouvertes.fr/hal-00486386
DOI : 10.2113/gssgfbull.181.2.197

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
The widely-used herbicide atrazine (ATZ) is detected in ground and surface water in many countries. Several studies in animals have demonstrated that ATZ has endocrine-disrupting effects on male and female reproduction in many vertebrate species. In this study, we investigated the effects of ATZ exposure on meiosis, a key step in gametogenesis in mammals. The treatment was initiated before oocyte entry into meiosis, which occurs during the embryonic period in females. We found that embryonic exposure to ATZ increases the level of 8-oxo-guanine in the nucleus of meiotic cells, reflecting oxidative stress and affecting meiotic double-strand break repair, chromosome synapsis and crossover numbers. Finally, embryonic exposure to ATZ reduces the number of primordial follicles and increases the incidence of multi-oocyte follicles in adult mice. Our data demonstrate that embryonic exposure to ATZ disrupts prophase I of meiosis and affects normal follicle formation in female mice.
ISSN: 2045-2322

hal-01560149
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560149
DOI : 10.1038/s41598-017-03738-1
PUBMED : 28615648

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Although ants may induce community-wide effects via changes in physical habitats in terrestrial environments, their influence on aquatic communities living in plant-held waters remains largely underexplored. The neotropical tank-bromeliad Aechmea mertensii (Bromeliaceae) occurs along forest edges in ant-gardens initiated by Camponotus femoratus or by Pachycondyla goeldii. Its leaves form wells that hold rainwater and provide suitable habitats for many aquatic organisms. We postulated that these ant-plant mutualisms indirectly affect the microbial community structure via changes in the environmental conditions experienced by the plants. To test this hypothesis, we analyzed the protist communities from 63 tank-bromeliads associated with either C. femoratus or P. goeldii (hereafter Cf-Aechmea and Pg-Aechmea) along a forest edge in French Guiana. For each plant, a large number of environmental variables (including habitat structure, food resources, incident radiation and the presence of aquatic invertebrates) were quantified to determine their relative importance in driving any observed differences across ant-associated plants. Pg-Aechmea are located in sun-exposed areas and hold low volumes of water and low amounts of detritus, whereas Cf-Aechmea are located in partially shaded areas and accumulate higher amounts of water and detritus. Protists (i.e., protozoa and algae) inhabiting Cf-Aechmea exhibit greater richness and abundances than those in Pg-Aechmea. Variations in detritus content, number of leaves, incident radiation, and the epiphyte richness of the ant-garden were the main factors explaining the variation in protist richness. A shift in the functional group composition of protists between bromeliads tended by different ant species suggested that mutualistic ants indirectly mediate changes in the microbial food web.
Basic and Applied Ecology

hal-00913126
https://hal.archives-ouvertes.fr/hal-00913126
https://hal.archives-ouvertes.fr/hal-00913126/document
DOI : 10.1016/j.baae.2012.10.002
OATAO : 10190

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 Elsevier
Résumé : International audience
This paper focuses on the analyses of the clastic sedimentary infill of the Coastal Plain of Eastern Mexico, which initiated synchronously with the Laramide orogeny in the vicinity of the Golden Lane. Results of these analyses are used as boundary conditions for calibrating/interpreting seismic profiles across more distal depocenters in the offshore of the Gulf of Mexico, from the sea shore and continental slope in the west to the abyssal plain in the east. The objective of the study is to better predict the reservoir distribution in the Deep offshore Basin of the Gulf of Mexico (DBGM), in order to explore for petroleum. The Coastal Plain is underlain by three morpho-tectonic domains: the tectonic front of the Sierra Madre Orientale (SMO), the Chicontepec deep water flexural basin, and the Tuxpan Platform (also known as the Golden Lane). Each domain is characterized by a distinct, dominantly siliciclastic Cenozoic lithostratigraphy. After a Jurassic rifting episode, followed by thermal subsidence, the oceanic basin and its western passive margin were deformed during the Upper Cretaceous and Paleogene, by far field stresses associated with the Cordilleran-Laramide Orogeny. Starting in the Late Cretaceous-Early Paleogene and during the Early Eocene, the tectonic load associated with the Laramide Orogen (Sierra Madre Oriental, SMO) caused flexural subsidence of the foreland located under the Coastal Plain. During this period, a massive transfer of siliciclastic sediments occurred from the Laramide foothills into the adjacent foreland. Sediments were eroded of the Sierra Madre tectonic wedge. Loading by these sediments pushed source units associated with the former passive margin down ward. The first syn-tectonic sediments of the Laramide orogeny were turbiditic silt layers in submarine fans which record also numerous collapse episodes and gravity slides. During the Late Eocene and Oligocene, the flexural subsidence stopped in the hinterland, whereas the subsidence of the passive margin resumed. This resulted in a change in the overall sedimentary architecture of the basin. Paleo-highs and reefs facies of the Golden Lane were flooded. Clastics by-passed the reefs and progradational clastic stratification formed as sediment moved towards the DBGM in the east. The final depositional environment of the continental platform/Coastal Plain became deltaic, marked by a succession of sand bars, levees and channels systems. From Miocene times onward, a system of gravitational listric faults developed near the platform to slope transition, resulting in a coeval compressional system at the transition between the slope and the abyssal plain. This system is driven by sediments charge. Because the sedimentation rate is larger than the subsidence, a large amount of clastics and slumped sediments are deposited in hangingwall basins.
ISSN: 0264-8172

hal-00424586
https://hal.archives-ouvertes.fr/hal-00424586
DOI : 10.1016/j.marpetgeo.2008.03.009

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Dans les Antilles françaises, les réflexions sur le concept de développement durable se bornent essentiellement à la protection de l’environnement. En Martinique, la problématique du développement durable a été traitée pour la première fois par un élu, leader d’une association écologiste ; cette approche a été renforcée par le Conseil Général de la Martinique dans le cadre d’un AGENDA 21, qui met fortement l’accent sur la problématique des risques et de la biodiversité. Cette approche environnementale est aujourd’hui relayée par les organisations syndicales et patronales siégeant au sein de l’Association Régionale pour l’Amélioration des Conditions de Travail (ARACT). Cette démarche vise à inscrire la dimension sociale dans la dynamique du développement durable impulsée en Martinique.
In the French West Indies, reflections on the concept of sustainable development are mainly oriented to the protection of the environment. In Martinique, the challenge of initiating sustainable development was first proposed by a politician, and a leader of an ecological association; this approach has been reinforced by the General Council of Martinique as part of AGENDA 21, which puts strong emphasis on the issue of natural risks and biodiversity. This approach to the environment is now backed by trade unions and employer organizations that serve within the Regional Association for the Improvement of Working Conditions. This approach aims to make the social dimension in the dynamics of sustainable development more evident in Martinique. La quête du sens
Martinique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.471
http://journals.openedition.org/etudescaribeennes/471

Éditeur(s) : HAL CCSD International Medical Press
Résumé : International audience
Background: Although the role of clinical/biological factors associated with mortality has already been explored in HIV-infected patients on antiretroviral therapy (ART), to date little attention has been given to the potential role of social vulnerability. This study aimed to construct an appropriate measure of social vulnerability and to evaluate whether this measure is predictive of increased mortality risk in ART-treated patients followed up in the ANRS CO8 APROCO-COPILOTE cohort.Methods: The cohort enrolled 1,281 patients initiating a protease inhibitor-based regimen in 1997–1999. Clinical/laboratory data were collected every 4 months. Self-administered questionnaires collected psycho-social/behavioural characteristics at enrolment (month [M] 0), M4 and every 8–12 months thereafter. A multiple correspondence analysis using education, employment and housing indicators helped construct a composite indicator measuring social vulnerability. The outcome studied was all-cause deaths occurring after M4. The relationship between social vulnerability and mortality, after adjustment for other predictors, was studied using a shared-frailty Cox model, taking into account informative study dropout.Results: Over a median (IQR) follow-up of 7.9 (3.0–11.2) years, 121 deaths occurred among 1,057 eligible patients, corresponding to a mortality rate (95% CI) of 1.64 (1.37, 1.96)/100 person-years. Leading causes of death were non-AIDS defining cancers (n=26), AIDS (n=23) and cardiovascular diseases (n=12). Social vulnerability (HR [95% CI] =1.2 [1.0, 1.5]) was associated with increased mortality risk, after adjustment for other known behavioural and bio-medical predictors.Conclusions: Social vulnerability remains a major mortality predictor in ART-treated patients. A real need exists for innovative interventions targeting individuals cumulating several sources of social vulnerability, to ensure that social inequalities do not continue to lead to higher mortality.
ISSN: 1359-6535

hal-01299300
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01299300
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01299300/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01299300/file/Twelve-year%20mortality%20in%20HIV-infected%20patients_accepted.pdf
DOI : 10.3851/IMP2960

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Introduction: The value and challenges of long-term prophylaxis (LTP) in adolescents and young adults need further characterisation.Aim: To determine the proportions of adolescents and young adults with severe or moderately severe haemophilia in France under LTP and treatment on demand (OD).Methods: Patients 15 to 25 years old with haemophilia A or B, factor VIII/IX ≤ 2% and no current inhibitor could be included if they had been under factor VIII/IX treatment at least 12 months and kept a treatment and bleeding diary.Results: LTP was administered to 169/212 patients (79.7%) and OD treatment to 40/212 patients (18.9%). The most frequent reasons for initiating LTP were joint bleeding, target joints and frequent bleeds; whereas OD treatment was most often selected on the basis of mild bleeding phenotype or because of constraints on LTP. The mean annual bleed rate (ABR) in the OD group (6.33) was higher than in the LTP group (3.07, p < 0.001). Mean ABR did not differ significantly between age strata (15–18, > 18–21 and > 21–25 years), but was significantly higher for patients with severe haemophilia (4.02) as compared to those with moderate haemophilia (1.97, p = 0.002). No significant difference was observed in mean ABR for joint bleeds between the LTP and OD groups. Physician reported LTP compliance was good or excellent in 97.0% of patients.Conclusion: LTP is the predominant factor VIII/IX treatment among adolescents and young adults with severe or moderately severe haemophilia in France. LTP was associated with low ABR and high compliance. © 2017 The Authors
ISSN: 0049-3848

hal-01467550
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467550
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467550/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467550/file/Choice%20of%20factor%20VIII-IX%20regime.pdf
DOI : 10.1016/j.thromres.2016.12.023

Éditeur(s) : HAL CCSD Geological Society of London
Résumé : The Borborema and Benin–Nigeria provinces of NE Brazil and NW Africa, respectively, are key areas in the amalgamation of West Gondwana by continental collision during the Brasiliano/Pan-African orogenies. Both are underlain by complex basement: Nigeria has c. 3.05 Ga Archaean crust but no known Palaeoproterozoic rocks >2.0 Ga; in NE Brazil, 2.6–3.5 Ga Archaean rocks form small cores within Palaeoproterozoic gneiss terrains affected by plutonism at c. 2.17 Ga. Both regions exhibit Late Palaeoproterozoic (c. 1.8 Ga) rift-related magmatism and metasedimentary sequences overlying the basement. The Seridó Group of NE Brazil (<0.65 Ga) is similar to the Igarra Sequence in SW Nigeria. The Ceará Group, which may date back to c. 0.85 Ga, is a passive margin deposit on crust thinned during initiation of an oceanic domain. In both provinces, basement and sedimentary cover were involved in tangential tectonics that resulted in crust-thickening by nappe-stacking associated with closure of this ocean. Frontal collision between c. 0.66 and 0.60 Ga later evolved to an oblique collision, generating north–south continental strike-slip shear zones at c. 0.59 Ga. In NE Brazil, the main Pan-African suture is probably buried beneath the Parnaíba Basin. The Transbrasiliano Lineament, interpreted as the prolongation of the Kandi–4°50 Lineament in Hoggar, may represent a cryptic suture.
West Gondwana: Pre-cenozoic correlations across the south atlantic region

hal-00412234
https://hal.archives-ouvertes.fr/hal-00412234
DOI : 10.1144/SP294.4

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Baikal Rift System in southern Siberia is one of the main intracontinental extensional features on Earth. The rift system represents the northwestern boundary of the Amuria plate and in that respect can be considered as an evolving plate boundary. The Baikal Rift System has been widely studied both in terms of geology and geophysics and many models have been proposed for its formation and evolution. However, the age of the initiation of deformation and the mechanism driving this deformation are still largely debated. While major extension has occurred since the Late Miocene-Pliocene, the onset of extension seems older than the India-Asia collision, implying that several driving mechanisms may have acted together or in relay through time. In this work, we review the available data and models for deformation in an area encompassing the Baikal Rift System, the Sayan ranges to the west and the Transbaikal to the east. Using a synthesis of this data and our own field and mapping observations, we show that the Baikal Rift System, along with transpressional deformation in the Sayan ranges and transtension in the Transbaikal area, can be explained through major left-lateral strike-slip systems. The deformation is strongly controlled by inherited crustal and lithospheric structures, and is distributed over a wide area within the western Amuria plate that consequently cannot be considered as a rigid block. Such distributed deformation is likely to have a strong effect on the structure of the future continental margin if extension evolves towards the formation of oceanic crust.
ISSN: 1342-937X

hal-00903612
https://hal.archives-ouvertes.fr/hal-00903612
DOI : 10.1016/j.gr.2012.07.017

Éditeur(s) : HAL CCSD
Résumé : Subduction is one of the major geodynamical process active during the Earth evolution. The characterization of arc magmas, their evolution through space and time, and the relationship between arc magmatism and continental crust forming processes, constitute the main research topics in petrology and geochemistry since the last three decades. This study focuses on an exhumed portion of the Kohistan Arc (N Pakistan), which is an exceptional ‘in situ' laboratory to study and follow through time the processes active on subduction zones. Based on a pluri-geochemical approach, this study allows unraveling two major issues : 1/ The lack of a cogenetic relationship between the arc root (i.e. ultramafic rocks) and the overlying gabbroic crustal section. The Jijal ultramafic section does not bear a crustal origin and was emplaced at ~117 Ma via a magma-rock reaction between REE-depleted ‘boninite-like' melts and the pre-existing lithospheric mantle with Indian-MORB affinities; 2/ A three-stage geodynamical model covering the arc evolution through ~30 Ma. This model starts with the onset of the subduction followed by the building of the volcanic arc (1st stage). The 2nd stage corresponds to a major thermal event, characterized by abundant magma underplating and by granulitisation of the arc base. Recycling of the residual/cumulative lower crust into the convective asthenospheric mantle was efficient during this stage, and probably related to thermo-mechanical erosion processes. The last stage, between ~95 and 85 Ma, seals the end of the intra-oceanic subduction and corresponds to an “amagmatic” period. This step is followed by a voluminous, but short, magmatic pulse at ~85 Ma, occurring just before the arc-continent collision. At last, this study emphasizes the more mafic composition of the investigated crustal arc section when compared to the bulk continental crust. Nevertheless the arc section composition nicely fits with the lower continental crust average.
Les zones de subduction représentent des zones d'évolution clés dans la compréhension des processus géologiques majeurs actifs sur notre planète. En particulier, la caractérisation et l'évolution des magmas générés dans les zones d'arcs océaniques et la relation entre leur genèse et les processus de croissance crustale sont des axes primordiaux. Cette étude est focalisée sur la portion d'arc océanique exhumée du Kohistan (Nord Pakistan) qui constitue un laboratoire exceptionnel pour appréhender cette problématique. Basée sur une approche géochimique multi-méthodes (éléments majeurs et en trace, isotopes), cette étude a permis d'établir : 1/ l'absence de relation génétique directe entre les roches ultrabasiques de la racine de l'arc et la section crustale sus-jacente. La formation de la séquence ultrabasique de Jijal se produit à ~117 Ma via une réaction de type magma-roche entre des liquides de type boninitique (appauvris en terres rares), et le manteau lithosphérique de type MORB-Indien ; 2/ un modèle géodynamique en trois stades majeurs résumant l'évolution de l'arc océanique et de la subduction sur une période d'environ 30 Ma. Ce modèle débute par l'initiation de la subduction et la formation de l'arc volcanique s.s. (1er stade) ; le 2ème stade correspond à un évènement thermique majeur. Il est représenté par un sous-placage important de magmas et une granulitisation intense de la base de l'arc. Le recyclage de la croûte inférieure cumulative et résiduelle, dans le manteau sous-jacent, se produit durant cette étape vraisemblablement suite à des processus d'érosion thermo-mécanique. Le dernier stade, entre 95 Ma et 85 Ma, scelle la fin du fonctionnement de la zone de subduction et correspond à une période amagmatique suivie par une brève reprise du magmatisme avant la collision de l'arc après 85 Ma. Enfin, une modélisation numérique comparative avec la croûte continentale globale met en évidence la composition significativement plus basique de la croûte de l'arc insulaire du Kohistan. De fortes similitudes sont en revanche observées entre la section d'arc étudiée et la croûte continentale inférieure.
https://tel.archives-ouvertes.fr/tel-00437770

tel-00437770
https://tel.archives-ouvertes.fr/tel-00437770
https://tel.archives-ouvertes.fr/tel-00437770/document
https://tel.archives-ouvertes.fr/tel-00437770/file/thesedhuime.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Understanding subduction rheology in both space and time has been a challenge since the advent of plate tectonics. We herein focus on "subduction infancy", that is the first ~1-5 My immediately following subduction nucleation, when a newly born slab penetrates into the upper plate mantle and heats up. The only remnants of this critical yet elusive geodynamic step are thin metamorphic soles, commonly found beneath pristine, 100-1000 km long portions of oceanic lithosphere emplaced on continents (i.e., ophiolites).Through the (i) worldwide compilation of pressure-temperature conditions of metamorphic sole formation augmented by pseudosection thermodynamic modeling, (ii) calculations of the viscosity of materials along the plate interface and (iii) generic numerical thermal models, we provide a conceptual model of dynamic plate interface processes during subduction infancy (and initiation s.l.).We show in particular how major rheological switches across the subduction interface control slab penetration, and the formation of metamorphic soles. Due to the downward progression of hydration and weakening of the mantle wedge with cooling, the lower plate (basalt, sediment) and the upper plate (mantle wedge) rheologies equalize and switch over a restricted temperature-time-depth interval (e.g., at ~800°C and ~1 GPa, during 0.1-2 My, for high-temperature metamorphic sole formation). These switches result in episodes of maximum interplate mechanical coupling, thereby slicing the top of the slab and welding pieces (basalt, sediment) to the base of the mantle wedge. Similar mechanical processes likely apply for the later, deeper accretion and exhumation of high-temperature oceanic eclogites in serpentinite mélanges, or for the accretion of larger tectonic slices.This model provides constraints on the effective rheologies of the crust and mantle and general understanding, at both rock and plate scale, for accretion processes and early slab dynamics.
AGU Fall Meeting 2015
San Francisco, United States

insu-01242103
https://hal-insu.archives-ouvertes.fr/insu-01242103

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
This article studies the associative movement of people with a motor disability in Guadeloupe (FWI), which has contributed to the development of the care activities on the island. The first self-regulated associations, initiated at the beginning of the 1980s, were to influence the structuration of the new social and medico-social sector. From the analysis of the main actors’ interviews and archival materials, we can notice a double identity claim: a disabled people identity and a Guadelupian identity. This double identity claim will influence the care activities. While at first, the adjustment with the mainland France is looked for, the actors also provide an anti-authority speech, which puts forward Guadelupian specificities about the care activities.
Cet article étudie le mouvement associatif de personnes présentant une déficience motrice en Guadeloupe, département français d’outre-mer (DOM), qui a contribué au développement de la prise en charge du handicap sur l’île. Les premières associations autogérées, émergeantes au début des années 1980 vont influencer la structuration du jeune secteur social et médico-social. Sur la base d’une analyse des témoignages des acteurs de ce mouvement et d’archives associatives, nous avons pu relever que l’identité mobilisatrice est double : celle de personne ayant des incapacités et celle de Guadeloupéen. Cette double identité aura pour conséquence de donner une coloration particulière aux activités du care. Alors que dans un premier temps, le « rattrapage » avec la métropole est souhaité, les acteurs mobilisent également un discours contestataire en mettant en avant les spécificités guadeloupéennes dans la prise en charge des personnes handicapées.
ISSN: 1875-0672

Droits : info:eu-repo/semantics/OpenAccess
hal-01679051
https://hal.archives-ouvertes.fr/hal-01679051
https://hal.archives-ouvertes.fr/hal-01679051v1/document
https://hal.archives-ouvertes.fr/hal-01679051/file/care%20et%20postcolonialisme-%20villoing%20et%20al.%20.pdf
DOI : 10.1016/j.alter.2014.11.002

Résumé : Depuis de nombreuses années, les biologistes étudiant des poissons d'eau douce, ont mis en évidence les relations existant entre le cycle de maturation et les facteurs environnementaux tels que la température et la photopériode (Bullough, 1940 ; Merinan & Schedl, 1941 ; Harrington 1957, Henderson, 1963...). En aquaculture, pour des espèces tempérées comme le loup, la dorade, le turbot, dès 1973, l'opportunité du décalage de la saison de ponte grâce au raccourcissement des cycles environnementaux naturels, est démontré (Girin & Devauchelle, 1978). Sur le loup (Dicentrarchus labrax), des pontes décalées ont pu être obtenues par manipulation du seuil facteur est également reprise par Suquet (1987) puis par Bouget (1988), sur la dorade (Sparus aurata). Devauchelle (1980) démontre que la maturation et la ponte du turbot (Scophthalmus maximus) se réalisent à température constante sans problème majeur. Bacon (1973) présente les plans d'un laboratoire à environnement contrôle utilisé par Kuo & al. (1974) pour des travaux sur le mullet (Mugil cephalus). D'autres travaux sont réalisés sur des espèces subtropicales comme Trachintous carolinus (Hoff & al. 1972, 1978). Pour une espèce tropicale telle que le milkfish Chanos chanos, Lee & al. (1987) concluent à une prépondérance du facteur photophase sur la température pour l'induction de la maturation. Chez Siganus guttatus, espèce tropicale à rythme de ponte mensuel, le facteur lumineux (cycle lunaire) semble être le plus important dans un milieu ou la température de l'eau est stade tout le long de l'année (plus ou moins 1 degré centigrade) (Soletchnik, non publié). Ainsi, chez les poissons tempérés, l'initiation de la maturation serait clairement déclenchée par l'augmentation de la photopériode (Bye & Htun Han, 1979). Harrington (1959), quant à lui, pense que l'influence de la température sur les poissons à longue saison de ponte est plus importante que celle de la photopériode. L'importance relative de l'un ou l'autre de ces deux facteurs, température et photopériode dans les processus physiologiques de maturation et de ponte de l'ombrine, sont actuellement à l'étude aux Etats Unis (Robert, Comm. pers.). L'opération envisagée en Martinique dès 987 est celle des transférer et d'adapter en conditions tropicales et dans un environnement insulaire une technologie développée dans différents états américains depuis le début des années 70. Les premiers cycles de maturation et ponte ont été initiés début 1989 avec la mise en fonctionnement des salles géniteurs à environnement contrôle. Les premiers résultats obtenus dans cette structure, et en cages flottantes sont décrits dans ce chapitre.

Droits : 1990 Ifremer
http://archimer.ifremer.fr/doc/00133/24408/22408.pdf
http://archimer.ifremer.fr/doc/00133/24408/

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : International audience
Meiotic DNA double-stranded breaks (DSBs) initiate genetic recombination in discrete areas of the genome called recombination hotspots. DSBs can be directly mapped using chromatin immunoprecipitation followed by sequencing (ChIP-seq). Nevertheless, the genome-wide mapping of recombination hotspots in mammals is still a challenge due to the low frequency of recombination, high heterogeneity of the germ cell population, and the relatively low efficiency of ChIP. To overcome these limitations we have developed a novel method--single-stranded DNA (ssDNA) sequencing (SSDS)--that specifically detects protein-bound single-stranded DNA at DSB ends. SSDS comprises a computational framework for the specific detection of ssDNA-derived reads in a sequencing library and a new library preparation procedure for the enrichment of fragments originating from ssDNA. The use of our technique reduces the nonspecific double-stranded DNA (dsDNA) background >10-fold. Our method can be extended to other systems where the identification of ssDNA or DSBs is desired.
ISSN: 1088-9051

hal-00877675
https://hal.archives-ouvertes.fr/hal-00877675
DOI : 10.1101/gr.130583.111
PUBMED : 22367190

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : International audience
– The 300 km long allochthonous sheet of oceanic mantle forming the New Caledonia ophiolite displays three specific characters: 1) the ophiolite pile lacks concordant sheeted dykes and pillow basalt layers; 2) the ophiolite, refered to as the Peridotite nappe, is thrusted over the basaltic formations of the Poya terrane which are classicaly thought to originate from a different oceanic environment; 3) The basal contact of the ultramafic sheet is remarkably flat all along New-Caledonia and the Peridotite nappe has not been thickened during obduction, rather it experienced significant extension. This suggests that the peridotites have not been emplaced by a tectonic force applied to the rear. New petrological and geochemical results obtained from mantle rocks finally show that the Poya terrane may originate from the same oceanic basin as the peridotites. In this article, we consider such possible cogenetic links and we propose a simple model for the obduction of the New Caledonia ophiolite in which the Poya basalts represent the original cover of the Peridotite nappe. We infer that continuous uplift of the subducted units buried beneath the oceanic lithosphere in the northern part of New Caledonia drove passive uplift of the ophiolite and led to erosion and to initiation of sliding of the basaltic layer. During the Priabonian (latest Eocene), products of the erosion of the basaltic layer were deposited together with sediments derived from the Norfolk passive oceanic margin. These sediments are involved as tectonic slices into an accretionary wedge formed in response to plate convergence. The volcaniclastic sedimentation ends up with the emplacement of large slided blocks of basalts and rafted mafic units that progressively filled up the basin. Obduction process ended with the gravity sliding of the oceanic mantle sheet, previously scalped from its mafic cover. This process is contemporaneous with the exhumation of the HP-LT units of Pouebo and Diahot. Gravity sliding was facilitated by the occurrence of a continuous serpentine sole resulting from metasomatic hydratation of mantle rocks, which developed during the uplift of the Norfolk basement and overlying Diahot and Pouébo units. Progressive emersion of the obducted lithosphere allowed subsequent weathering under subaerial, tropical conditions. Obduction passive et mise en place gravitaire des grandes nappes ophiolitiques : les ophiolites de Nouvelle-Calédonie (SW Pacifique) sont-elles un cas d'école ? Résumé. – La nappe de manteau de Nouvelle-Calédonie, s'étendant sur 300 km de long montre trois caractéristiques im-portantes: 1) La succession ophiolitique ne contient ni dykes, ni basaltes en coussin, 2) l'ophiolite est charriée sur des formations basaltiques (nappe de Poya) que l'on considère classiquement comme originaires d'un bassin océanique dif-férent de celui d'où est issu le manteau, et 3) le contact basal de la nappe ultrabasique est remarquablement plat tout le long de l'île et celle-ci n'a pas été épaissie durant l'obduction. Cela suggère que les péridotites n'ont pas été mises en place en réponse à une poussée tectonique arrière. De nouveaux résultats pétrologiques et géochimiques obtenus sur l'ophiolite montrent en réalité que les basaltes de Poya peuvent être extraits de la fusion du manteau de l'ophiolite. Nous proposons donc un nouveau modèle pour l'obduction, dans lequel les basaltes de Poya forment la couver-ture initiale primitive du manteau de la nappe des péridotites. La surrection progressive des unités profondes enfouies lors de la subduction de la lithosphère du bassin sud-Loyauté à l'Eocène, a permis le soulèvement passif de l'ophiolite et l'érosion puis le glissement des unités basaltiques. Durant le Priabonien, l'accumulation des produits de l'érosion de la couche des basaltes et de la marge passive de Norfolk ont formé les séquences de flysch comprenant localement des débris basaltiques grossiers. Ces sédiments font partie d'un prisme d'accrétion tectonique construit en réponse à la convergence au front de la subduction. La sédimentation détritique se termine par la mise en place de grandes unités ba-saltiques glissées qui comblent le bassin. Le processus de l'obduction se termine par le glissement gravitaire de l'écaille de manteau océanique sur les basaltes. Cet événement est contemporain de l'exhumation des unités HP-BT de Pouébo et du Diahot. Le glissement gravitaire a été facilité par la présence sous l'ophiolite, d'une semelle continue de serpentines résultant de l'interaction du manteau avec des fluides métasomatiques remontant durant l'exhumation des unités en-fouies pendant la subduction continentale. L'émersion progressive de la lithosphère obduite a placé le manteau dans des conditions d'altération supergène tropicale.
EISSN: 1777-5817

hal-01257702
https://hal.archives-ouvertes.fr/hal-01257702
https://hal.archives-ouvertes.fr/hal-01257702/document
https://hal.archives-ouvertes.fr/hal-01257702/file/Lagabrielleetal-BSGF-2012-revised-light.pdf
DOI : 10.2113/gssgfbull.184.6.545

Éditeur(s) : HAL CCSD Éditions de la Maison des sciences de l'homme
Résumé : International audience
For over a century, the complementary nature of fishing and farming activities in the floodplain of the Rufiji River (Tanzania) has formed the basis of the economy in its villages. Starting in the 1970s, the fishery evolved from a seasonal activity practiced on foot during flooding and using traditional traps to year-round dugout canoe operated lake fisheries using nets.The paper analyses the drivers of this change. After having rejected the simplistic technocratic hypothesis that technical innovation equals progress, the paper examines the relevance of the productivity of the different fishing techniques in the light of the evolution of the role of fisheries in the village economy. During the change-over period, the national and international economy deprives the villages of their main habitual sources of cash income. In the absence of any alternative, fisheries imposed themselves as the unique source of cash income, a function they can only fulfil if practiced year-round and this can only be achieved using canoes and nets. However, the perception of the causes of these changes in the villages is differentiated. For those who initiated the change-over, and who are now of an advanced age, the main driver of the transition to nets was the empowerment of the youth versus the elders. Such an interpretation resonates well with the economic determinants. However, it requires considering the modernisation process as a contextualised multi-sided expression of market globalisation.
Depuis plus d’un siècle, l’économie des villages de la plaine inondable du Rufiji (Tanzanie) est fondée sur la complémentarité des activités agricoles et des activités halieutiques. À partir de la fin des années 1970, les pêches traditionnelles à la nasse, pratiquées à pied saisonnièrement lors de la crue annuelle, sont supplantées par les pêches embarquées (pirogues monoxyles) au filet dans les lacs, pratiquées elles toute l’année. L’article s’interroge sur les déterminants de cette substitution.Après avoir rejeté l’hypothèse techniciste vulgaire qui voudrait que l’innovation technique soit synonyme de progrès, la pertinence du critère de productivité des différentes techniques de pêche est examinée à la lumière de l’évolution de la place des activités halieutiques dans l’économie villageoise. Il apparaît qu’à partir de cette époque, l’évolution économique nationale et internationale prive les villageois de leurs principales ressources monétaires habituelles. En l’absence de toute alternative, la pêche s’impose alors comme unique source de revenu monétaire, une fonction qu’elle ne peut remplir qu’à condition d’être pratiquée tout au long de l’année, ce que seules les techniques au filet permettent. Cependant, les représentations villageoises des causes de la généralisation de la pêche au filet sont différentes. Pour ceux d’entre eux, aujourd’hui très âgés, qui furent les pionniers de cette innovation, c’est le souci d’émancipation des cadets vis-à-vis des aînés qui aurait été le moteur de l’adoption de techniques de pêche au filet. Ce point de vue entre en résonance avec les déterminations économiques à condition de considérer le processus de modernisation comme manifestation multiforme contextualisée de la mondialisation marchande.
ISSN: 0248-6016

hal-01344410
https://hal.univ-antilles.fr/hal-01344410
https://hal.univ-antilles.fr/hal-01344410/document
https://hal.univ-antilles.fr/hal-01344410/file/Pauletal2015Version_Def.pdf

Éditeur(s) : HAL CCSD Berlin: A. Asher & Co.
Résumé : International audience
In this work, we compare IASI-retrieved vertical water vapour profiles and related precipitable water over a complex region, namely the Rhine Valley area, during the pre-operational period of IASI exploitation (June?August 2007). Both IASI water vapour mixing ratio profiles and integrated water vapour content are retrieved from L1C radiances spectra using two techniques and compared with water vapour related observations acquired during the Convective and Orographically-induced Precipitation Study (COPS) field campaign that took place in this area at that time (i.e. lidars, radiosoundings and a global positioning system - GPS - station network). This work addresses the issue of IASI vertical spatial resolution and its capability to detect two-layer water vapour structures such as those observed in a mountainous area and which play an important role in convective initiation or inhibition. We found that this capability mostly relies on the type of a-priori background vector (climatology or space-time colocated ECMWF analysis), which is used within the retrieval scheme. Systematic comparison of water vapour products derived from 71 IASI spectra confirms that IASI can retrieve water vapour amounts in 2 km width layers, in the lower troposphere, with an accuracy of approximately 10%.
ISSN: 0369-1845

hal-00923710
https://hal.archives-ouvertes.fr/hal-00923710
https://hal.archives-ouvertes.fr/hal-00923710/document
https://hal.archives-ouvertes.fr/hal-00923710/file/masiello.pdf
DOI : 10.1127/0941-2948/2013/0430

Éditeur(s) : HAL CCSD
Résumé : International audience
La gestion de projets multi-acteurs est très complexe, eu égard aux cycles de vie de plus en plus courts des concepts et technologies, aux nouvelles normes réglementaires auxquelles les acteurs ne peuvent se soustraire, et à l’augmentation du nombre de parties prenantes, qui travaillent de manière cloisonnée.Pour relever ces défis, comment gérer la complexité de ces projets et les profils des différents acteurs ? Plus précisément, comment les faire collaborer efficacement afin d’optimiser les échanges, les remontées d’information et les arbitrages ?A travers une recherche-intervention (David, 2000) menée sur une période de plus de trois ans, nous analysons les pratiques d’un groupe d’entreprises réunies autour d’un projet fédérateur. Ce dernier, intitulé « Forest Initiative », rassemble les compétences de partenaires d’affaires dans le but de développer de nouveaux modèles d’aménagement agricole. Afin de mener à bien ce projet, les parties prenantes ont crée un modèle d’affaires innovant : un Ecosystème d’Affaires (EA). Il s’agit de rassemblements d’entreprises et d’acteurs provenant de secteurs d’activités différents, liés de façon formelle ou non, qui ont tous intérêt à promouvoir leurs standards technologiques respectifs pour garder leur leadership (Moore,1996).En liant les champs des EA et de la gestion de projet, notre recherche aboutit à proposer une nouvelle voie d’exploration pour la compréhension de la conduite de projets complexes au sein de groupes d’entreprises.
84e congrès de l'Association Francophone pour le Savoir (ACFAS)
MONTREAL, Canada

hal-01314738
https://hal.archives-ouvertes.fr/hal-01314738

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : International audience
Guadeloupe island (West French Indies) is one of the twenty islands that compose the Lesser Antilles arc, which results from the subduction of the Atlantic ocean plate beneath the Caribbean one. The island lies in a complex volcano-tectonic system and the need to understand its geological context has led to numerous on- and offshore geophysical investigations. This work presents a compilation and the processing of available, on-land, airborne and marine, gravity and magnetic data acquired during the last 40 years on Guadeloupe islands and at the scale of the Lesser Antilles arc. The overall dataset provides new Bouguer and reduced to the pole magnetic anomaly maps at the highest achievable resolution. Regionally, the main central negative gravity trend of the arc allows defining two subsident areas. The first one is parallel to the arc direction (~N160°E) to the north, whereas the second unexpected southern one is oriented parallel to oceanic ridges (N130°E). Along the Outer arc, the long wavelength positive anomaly is interpreted, at least along the Karukera spur, as an up-rise of the volcanic basement in agreement with the seismic studies. To the NE of Guadeloupe, the detailed analysis of the geophysical anomalies outlines a series of structural discontinuities consistent with the main bathymetric morphologies, and in continuity of the main fault systems already reported in this area. Based on geophysical evidences, this large scale deformation and faulting of the Outer arc presumably primarily affects the Atlantic subducting plate and secondarily deforms the upper Caribbean plate and the accretion prism, as evidenced in bathymetry as well as on the islands. At the scale of Guadeloupe island, combined gravity and magnetic modeling has been initiated based on existing interpretation of old seismic refraction profiles, with a general structure in three main layers. According to our geophysical anomalies, additional local structures are also modeled in agreement with geological observations: i) the gravity and magnetic signals confirm an up-rise of the volcanic basement below the limestone platforms outcropping on Grande-Terre island ; ii) the ancient volcanic complexes of Basse-Terre island are modeled with high density and reverse magnetized formations; iii) the recent volcanic centre is associated with formations consistent with the low measured density and the underlying hydrothermal system. The E-W models coherently image a NNW-SSE depression structure in half-graben beneath Basse-Terre island, its western scarp following the arc direction in agreement with bathymetric and seismic studies to the north of the island. The so-defined depressed area, and particularly its opening in half-graben toward the SW, is interpreted as the present-day front of deformation of the upper plate, associated with the recent volcanic activity on and around Guadeloupe. Based on this regional deformation model, perspectives are given for further integrated investigation of key targets to address the internal structure and evolution of the Lesser Antilles arc and Guadeloupe volcanic system.
EISSN: 1777-5817

hal-00853352
https://hal.archives-ouvertes.fr/hal-00853352
DOI : 10.2113/gssgfbull.184.1-2.77