Éditeur(s) : HAL CCSD Geological Society of America
Résumé : International audience
Integrated Ocean Drilling Program Expedition 313 continuously cored uppermost Eocene to Miocene sequences on the New Jersey shallow shelf (Sites M27, M28, and M29). Previously, 15 Miocene (ca. 23-13 Ma) seismic sequence boundaries were recognized on several generations of multichannel seismic profi les using criteria of onlap, downlap, erosional truncation, and toplap. We independently recognize sequence boundaries in the cores and logs based on an integrated study of core surfaces, lithostratigraphy and process sedimentology (grain size, mineralogy, facies, and paleoenvironments), facies successions, stacking patterns, benthic foraminiferal water depths, downhole logs, core gamma logs, and chronostratigraphic ages. We use a velocitydepth function to predict the depths of seismic sequence boundaries that were tested by comparison with major core surfaces, downhole and core logs, and synthetic seismograms. Using sonic velocity (core and downhole), core density, and synthetic seismograms, we show that sequence boundaries correspond with acoustic impedance contrasts, although other stratal surfaces (e.g., maximum fl ooding and transgressive surfaces) also produce refl ections. Core data are suffi cient to link seismic sequence boundaries to impedance contrasts in 9 of 12 instances at Site M27, 6 of 11 instances at Site M28, and 8 of 14 instances at Site M29. Oligocene sequences have minimal lithologic and seismic expression due to deep-water locations on clinoform bottomsets. Miocene sequences (ca. 23-13 Ma) were sampled across several unconformity clinothems (prograding units) on topset, foreset, and bottomset locations. Excellent recovery allows core-seismic integration that confi rms the hypothesis that unconformities are a primary source of impedance contrasts. Our core-seismic-log correlations predict that key seismic surfaces observed in other sub surface investigations without core and/or well logs are stratal surfaces with sequence stratigraphic signifi cance.
EISSN: 1553-040X

insu-00946235
https://hal-insu.archives-ouvertes.fr/insu-00946235
DOI : 10.1130/GES00858.1

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
We present a set of single-well injection withdrawal tracer tests in a paleoreef porous reservoir displaying important small-scale heterogeneity. An improved dual-packer probe was designed to perform dirac-like tracer injection and accurate downhole automatic measurements of the tracer concentration during the recovery phase. By flushing the tracer, at constant flow rate, for increasing time duration, we can probe distinctly different reservoir volumes and test the multiscale predictability of the (non-Fickian) dispersion models. First we describe the characteristics, from microscale to meter scale, of the reservoir rock. Second, the specificity of the tracer test setup and the results obtained using two different tracers and measurement methods (salinity-conductivity and fluorescent dye­optical measurement, respectively) are presented. All the tracer tests display strongly tailed breakthrough curves (BTC) consistent with diffusion in immobile regions. Conductivity results, measured over 3 orders of magnitude only, could have been easily interpreted by the conventional mobile-immobile (MIM) diffusive mass transfer model of asymptotic log-log slope of 2. However, the fluorescent dye sensor, which allows exploring much lower concentration values, shows that a change in the log-log slope occurs at larger time with an asymptotic value of 1.5, corresponding to the double-porosity model. These results suggest that the conventional, one-slope MIM transfer rate model is too simplistic to account for the real multiscale heterogeneity of the diffusion-dominant fraction of the reservoir.
ISSN: 0043-1397

insu-00373695
https://hal-insu.archives-ouvertes.fr/insu-00373695
https://hal-insu.archives-ouvertes.fr/insu-00373695/document
https://hal-insu.archives-ouvertes.fr/insu-00373695/file/Gouze_et_al-2008-Water_Resources_Research.pdf
DOI : 10.1029/2007WR006278

Éditeur(s) : HAL CCSD Copernicus Publications
Résumé : International audience
During Ocean Drilling Program Leg 134, a mixed sequence of volcaniclastic and carbonate sediments was cored together with basaltic breccias and a single basalt sill in Hole 833B. In this study, data from Schlumberger's Geochemical Logging Tool, together with physical property logs, characterise part of the section and establish a complete log-derived lithostratigraphy. The major transition between the sedimentary rocks and a basaltic sill at 830 mbsf (metres below sea floor) is clearly seen as well as the distinction between the silicate-rich sediments and the carbonate-rich part of the section. The transition between the volcanic sandstone interbedded with basaltic and sed-lithic breccia of Unit III, and the volcanic sandstone of Unit IV is clearly marked by the physical property logs. The accuracy of the logging data was evaluated and discussed with an improved log versus core correlation. The cluster analysis of the complete data set shows a correlation with the data provided by the mechanical caliper device, which in turn indicates the quality of the borehole.
ISSN: 1816-8957

hal-00642165
http://hal.upmc.fr/hal-00642165
http://hal.upmc.fr/hal-00642165/document
http://hal.upmc.fr/hal-00642165/file/Rabaute_et_al-SciDrilling-1997.pdf

Éditeur(s) : HAL CCSD Springer
Résumé : Borehole logs provide in situ information about the fluctuations of petrophysical properties with depth and thus allow the characterization of the crustal heterogeneities. A detailed investigation of these measurements may lead to extract features of the geological media. In this study, we suggest a regularity analysis based on the continuous wavelet transform to examine sonic logs data. The description of the local behavior of the logs at each depth is carried out using the local Hurst exponent estimated by two (02) approaches: the local wavelet approach and the average-local wavelet approach. Firstly, a synthetic log, generated using the random midpoints displacement algorithm, is processed by the regularity analysis. The obtained Hurst curves allowed the discernment of the different layers composing the simulated geological model. Next, this analysis is extended to real sonic logs data recorded at the Kontinentales Tiefbohrprogramm (KTB) pilot borehole (Continental Deep Drilling Program, Germany). The results show a significant correlation between the estimated Hurst exponents and the lithological discontinuities crossed by the well. Hence, the Hurst exponent can be used as a tool to characterize underground heterogeneities.
ISSN: 1866-7411

hal-00617470
https://hal.archives-ouvertes.fr/hal-00617470
DOI : 10.1007/s12517-010-0129-y

Éditeur(s) : HAL CCSD Montpellier : CIRAD
Résumé : This article presents the effects of logging on the dynamics of above-ground biomass from the results of the post-logging study within two forests: Cikel in Eastern Para, Brazil and Paracou in French Guiana. The main objective is to compare the impact of commercial logging on the regeneration of the above-ground biomass in these forests whose characteristics differ in terms of structure and growth. In both sites, the intensity of exploitation is a key factor in determining the loss of biomass and the time required for its regeneration. In Paracou, the regeneration of biomass lost during conventional logging of 10 trees per hectare takes 45 years and more than 100 years when operating with higher intensity (21 trees/ha). In Cikei the forest biomass regenerates after 49 years harvesting 6 trees/ha and that takes 87 years after removal of 8 trees/ha. This regeneration needs similar time on both sites but with lower logging intensity at Cikel, in which felled trees are larger with a greater biomass than those of Paracou. This post-logging study has established a direct correlation of the dynamics of the biomass with the initial structure of the forest, as well as with the parameters of forest dynamics: mortality, growth and recruitment. The accumulation of biomass by the tree growth of the two remaining stands is a key parameter for the net carbon storage, while the contribution of recruitment in Paracou becomes significant only after 10 years after felling. Therefore in view to improve the growth of residual trees, it is compulsory to apply adequate silvicultural treatments such as selective thinning or removal of vines. While the two forests are geographically close enough, their regenerative abilities differ and because of the significant difference in size of the trees, the forest could tolerate more intensive harvesting in French Guiana
ISSN: 0006-579X

hal-01032427
https://hal.archives-ouvertes.fr/hal-01032427

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This paper proposes a new approach for the on-site detection of micropollutants in water in case of accidental or intentional contamination (characterized by high concentration). The technique is based on the use of an automatic multiple solid phase extraction step (MSPE) followed by direct or indirect UV spectrometry (MSPE/UV) for the detection of organic contaminants in water (such as regulated molecules (pesticides ...) as well as emerging pollutants (pharmaceutical products, endocrine disruptors ...)). The development of the system supposes firstly the choice of the most appropriate sorbent(s) and secondly conditions for the detection of targeted micropollutants, from several solid phase extraction cartridges and eluting solvents. Two different extraction sorbents were chosen. These sorbents and several eluting solvents allow the first separation of the compounds based on the physico-chemical properties of each substance (pKa, log Kow) and on the specific interactions with the sorbent. Finally, a UV analysis (either at the maximum of absorbance using a calibration curve or from the whole spectrum using a multicomponent (deconvolution) exploitation method) of each fraction allows a determination and a quantification of each compound. The method is rapid (less than 2 h), sensitive enough for an accidental/intentional contamination (between 5 and 40 μg*L− 1 according to the substances) and with a good precision (between 4 and 14%).
ISSN: 0026-265X

hal-00878024
https://hal.archives-ouvertes.fr/hal-00878024
DOI : 10.1016/j.microc.2012.10.025

Éditeur(s) : HAL CCSD
Résumé : poster presentation, 22nd European Meeting on Hypertension and Cardiovascular protection, London,26-29 April 2012
OBJECTIVE: Several studies demonstrate that the perception of overweight is associated with attempts at weight control in overweight subjects. Our objective is to describe the factors associated with the perception of overweight in an adult Caribbean population, and in particular, to assess the relationship between the perception of overweight and previous medical diagnosis of overweight. METHOD AND DESIGN: Consant was a cross-sectional study carried out in 2007 on a representative sample of the adult Guadeloupean population. Included were 1,005 subjects aged 25-74 years, drawn from stratified random sampling, and interviewed at home. The perception of overweight was evaluated by the question: "Do you consider yourself to be overweight?" with a binary response. RESULTS: Among overweight subjects (Body Mass Index ≥ 25 kg/m2, n = 576), 38.6% provided an incorrect assessment of their weight status. This proportion falls to 17.4% in those who stated to have previously received a medical diagnosis of overweight. However, only 48.8% of overweight subjects stated to have received such a diagnosis. A logistic regression shows that the underestimation of weight status is associated with the absence of previous diagnosis for overweight (OR: 5.35 - p < 10-3), as well as an age greater than or equal to 55 years (OR: 2.91 - p < 10-3), a BMI of less than 30 kg/m² (OR: 2.26 - p: 0.001), the male sex (OR: 1.86 - p: 0.004), and a low income level (OR: 1.62 - p: 0.030), but not a lack of awareness regarding the role of weight control in the prevention of cardiovascular diseases. Similar results are observed if waist circumference is taken as a factor instead of BMI. CONCLUSION: In this population, the lack of medical diagnosis of overweight was the leading factor associated with misperception of overweight. Screening for overweight therefore appears to be one of the preconditions to weight management, and remains a fundamental but often unused element in the fight against obesity.
https://hal.univ-antilles.fr/hal-00739785

Droits : info:eu-repo/semantics/OpenAccess
hal-00739785
https://hal.univ-antilles.fr/hal-00739785
https://hal.univ-antilles.fr/hal-00739785/document
https://hal.univ-antilles.fr/hal-00739785/file/The_lacksur screening_is_the_leading_factor_associated_with_the_misperceptionsur overweight_cor.pdf

Éditeur(s) : HAL CCSD
Résumé : The Franceville Basin (2.1 Ga) in southeastern Gabon, hosts a black shale series well preserved (FB Formation) which represents an exceptional example of unmetamorphised Paleoproterozoic sediment strata. This basin includes the protore of one of the largest Mn-oxide laterite ore worldwide, mined by Eramet-Comilog. The aim of this this work is to determine formation conditions of this protore and to characterize the global sedimentary evolution of the FB Formation which include the protore. This 75 m thick protore is constituted of Mn carbonate-rich black shales which represent a potential ore deposit for the future. It was drilled, on the Bangombé plateau, during a recent campaign of 24 boreholes with an average depth of 125 m.Through multidisciplinary study on these cores and key outcrops of the basin, this work focuses on : i) the depositional environment of the Mn-protore and FB Formation ; ii) the processes of formation of the Mn-carbonates at 2.1 Ga and iii) the architecture and distribution of Mn-rich levels of the protore on the Bangombé Plateau.A detailed sedimentological and petrological study allowed us to redefine the division of the FB into nine units, named U1 to U9 from the base to the top. These units show a fine upward cycle up to U5 and a reverse coarse loop until U9. This division leads to a new interpretation to propose an evolution from a shoreface depositional environment controlled by deltaic currents (U1) to an offshore depositional environment with anoxic conditions (U2). In this basin, a system of submarine fan is developed, feeding a network of sand injections (injectites) covering the Bangombé plateau (70 km²) and with a thickness of 150 m affecting U4 to U7, including the Mn-protore. The protore depositional environment formed below the wave base limit (U4, U5 and U6) in a starved basin, controlled by biochemical sedimentation allowed the formation of Mn-carbonates. The end of starved basin, would allow the re-opening of the detrital input into the offshore basin (U7). This basin is then filled by storm bar deposits intersected by deltaic sub-aquatic channels (U8). The U9 unit corresponds to a quiet lagoon environment, allowing the multicellular organism development for the first time on the planet.A geochemical study allowed the characterization of the depositional environment of Mn-carbonates as an anoxic to sub-oxic and alkaline environment. For the first time, we showed that the manganese carbonates, present as bacteriomorph forms, are precipitated from the seawater by the mediated photosynthetic cyanobacterial activity, which allows CO2 / HCO3 depression of the environment and a local increase of pH. The cyanobacterial activity is controlled by the absence of bottom currents, which increase the detrital input. This would stop the activity of the cyanobacteria and thus would lead to the decrease of the Mn-concentration along the protore.Finally, well-log and a sequential correlation analyses allowed us to detail spatial and timing repartition of FB Formation deposit, controlled by a tectono-sedimentary model. We propose two- tectono-sedimentary phases. A first syn-tectonic phase (U1 to U3) controls the depocentres and sedimentation gaps. Turbidite coarse deposits are located in the most subsident part, clay deposits rather on the slope and carbonates on shoals. A second post-tectonic phase (U4 to U7) allows isopach deposits. The Mn-protore formed during the post-tectonic phase. However, it shows a variable thickness due to subsidence to the north of the Bangombé plateau. So, on the Bangombé plateau, Mn-contents increase towards the south, whereas the protore thickness increases towards the NNE. Moreover sand injectites decrease Mn-content in the eastern part of the Bangombé plateau and impact on the economic evaluation of the Mn-carbonates. Currently, the protore is structured by post-sedimentary faults, which lead to a non-continuity of the high Mn levels on the Bangombé plateau.
Le Bassin de Franceville situé au SE du Gabon présente une série de black shales (Formation FB) d'âge Paléoprotérozoïque (2,1 Ga) surmontant les grès de la Formation FA. Ce bassin peu déformé et non métamorphique représente une archive exceptionnelle des processus de dépôt de cette période de l’histoire de la Terre où la vie commence à se développer. En particulier, la Formation FB contient le protore d'un gisement mondial d'oxydes de manganèse exploité par la société Eramet-Comilog. L’objectif de ce travail est de préciser les conditions de formation de ce protore et de le replacer dans l’histoire du remplissage du bassin. Ce protore d'une épaisseur moyenne de 75 m est constitué de carbonates de manganèse ; il a fait l'objet d'une récente campagne de 24 forages carottés d'une profondeur moyenne de 125 m sur le plateau de Bangombé.A travers une approche pluridisciplinaire comprenant l'étude de ces forages et des affleurements clefs du bassin, ce travail porte sur la caractérisation i) de l'environnement de dépôt du protore et des séries qui l'encadrent (du toit du FA au toit du FB) ; ii) du mode de formation des carbonates de Mn à 2,1 Ga et iii) de l'architecture et de la répartition des hautes teneurs en Mn du protore qui représente un gisement potentiel du futur.L’étude pétro-sédimentaire détaillée a permis de distinguer neuf unités (U1 à U9) au sein de la Formation FB organisées suivant un cycle rétrogradant jusqu’à U5 puis progradant jusqu’à U9. Ce découpage montre une évolution du milieu de dépôt depuis un domaine de shoreface contrôlé par des courants deltaïques (U1) évoluant vers des dépôts d’offshore restreint (U2). Ce bassin enregistre ensuite un système de chenaux-levées turbiditiques (U3) qui alimentent un réseau d'injectites reconnu sur l’ensemble du Pl. de Bangombé et qui traverse 150 m de série (U4 à U7) en affectant le protore et ainsi les teneurs en Mn. L'environnement de dépôt du protore (U5 et U6) marque l’isolement du bassin qui devient affamé et contrôlé par une sédimentation biochimique à l’origine du dépôt des carbonates de Mn. L'Unité 7 correspond à la réouverture des apports détritiques en domaine d'offshore supérieur puis en domaine de shoreface dominé par des dépôts de tempêtes et de chenaux sous-aquatiques deltaïques (U8), et enfin lagunaire (U9) dans lequel apparaissent les premiers métazoaires de l’histoire de la planète, suivant une séquence régressive.Une étude géochimique a permis de préciser les conditions de dépôt du protore qui se forme en milieu alcalin anoxique à sub-oxique. Dans ce milieu, nous montrons pour la première fois une précipitation directe des carbonates de Mn sous forme bactériomorphe induite par l'activité photosynthétique des cyanobactéries qui consomment le CO2/HCO3 et conduisent à une augmentation du pH favorable à la formation des carbonates de Mn. L'activité cyanobactérienne est conditionnée par l’absence de courants de fond qui augmentent la turbidité du milieu et stoppent cette dernière.Les corrélations diagraphiques et séquentielles permettent de préciser la répartition spatiale et temporelle du FB permettant ainsi de replacer le protore dans l’histoire tectono-sédimentaire du bassin. Une première phase syn-tectonique (U1 à U3) contrôle l’épaisseur et la mise en place de dépôts turbiditiques dans les parties subsidentes, de dépôts argileux sur les pentes et de dépôt de carbonates sur les hauts-fonds. La seconde phase post tectonique (U4 à U7) permet la mise en place de dépôts relativement isopaques, bien que le protore enregistre une subsidence plus importante au nord du Pl. de Bangombé. On observe ainsi, sur le Plateau de Bangombé, des teneurs en Mn qui augmentent vers le sud alors que l’épaisseur du protore augmente vers le NNE. Postérieurement au dépôt du FB, le protore est structuré par des failles qui le compartimentent en touches de piano limitant ainsi sa continuité sur le Plateau de Bangombé.
https://hal.archives-ouvertes.fr/tel-01621460

tel-01621460
https://hal.archives-ouvertes.fr/tel-01621460
https://hal.archives-ouvertes.fr/tel-01621460/document
https://hal.archives-ouvertes.fr/tel-01621460/file/these_Dubois2017-MnGabon.pdf

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
One of the main difficulties encountered when characterizing the hydrodynamic properties of a fractured aquifer is to identify the preferential flow paths within it. Different methods may be applied to determine the variability of the permeability at the borehole scale and to image the structure of the main flow zones between boreholes. In this paper, we compare the information obtained from different measurement techniques performed in a set of three 100 m depth wells (well-to-well spacing: 5­10 m) in a fractured crystalline rock setting. Geophysical logging and borehole-wall imaging are used to identify open and closed fractures intersecting the boreholes and their orientation. The comparison with flowmeter and single packer tests shows that few of the fractures interpreted as open from geophysical logs are significantly transmissive. Cross-borehole connectivity is first investigated from single packer tests with pressure monitoring in adjacent boreholes. To determine fracture zone connectivity, we propose a methodology simply based on the variation with packer depth of the ratio of the drawdown in the observation well and the drawdown in the pumping well. The results are compared to the analysis of cross-borehole flowmeter tests. We show that both methods provide consistent results with a similar level of information on connectivity.
ISSN: 0022-1694

insu-00221380
https://hal-insu.archives-ouvertes.fr/insu-00221380
DOI : 10.1016/j.jhydrol.2007.07.007

Éditeur(s) : HAL CCSD
Résumé : International audience
The Socotra Island belongs to the southern rifted margin of the Gulf of Aden and occupied in Neoproterozoic times a key position to constrain the age and the nature of the largely hidden Neoproterozoic rocks of the Arabian plate. Our integrated field, petrographic, geochemical and geochrono- logical study in the Neoproterozoic rocks recognises three main successive events: (a) high-temperature ductile defor- mation and metamorphism forming probably in a compressive or transpressive regime; (b) mafic to intermediate intrusions as vertical sheets, kilometre-scale gabbro laccoliths, mafic dike swarm and lavas which present mainly a depleted arc signature with some evidences of evolution from an enriched-arc signature; (c) felsic intrusions mainly composed of highly potassic calc-alkaline and pinkish granites dated between 840 and 780 Ma. Relationships between the various petrographic types and U-Pb data suggest that these events occurred during a relatively short time span (80 Ma at max). Earlier high-temperature-low-pressure metamorphism stage as well as geochemical signature of mafic rocks show that development of Cryogenian formations of Socotra were controlled successively by an Andean-arc and a back-arc setting. These features cannot be easily reconciled with those of the Arabian-Nubian shield to the west of Socotra and of the Mozambique Belt to the south. We propose that the Socotra basement was developed at an active margin close to the India block in Cryogenian times.
Arabian Journal of Geoscience

hal-00647487
https://hal.archives-ouvertes.fr/hal-00647487
DOI : 10.1007/s12517-011-0476-3

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Coastal aquifers often display seawater intrusion resulting in the formation of a salty water wedge progressing inland. This study investigates the mass transfers in the mixing zone at the freshwater-seawater interface where the water is out of equilibrium with the rock-forming carbonates. Investigations were conducted in two boreholes, separated by 5 m, at the Ses Sitjoles test site (Mallorca Island, Spain) where repeated electrical conductivity logs of the formation and the saturating fluid, as well as regular pore-water sampling and permanent downhole multi-parameter monitoring of the water were performed over a period of 9 a. In the mixing zone, the significant acidification, the calcite saturation index profile and the Ca concentration profile cannot be explained by conservative mixing nor by dissolution-precipitation reactions only. Conversely, the analysis of organic C content and of the distinctly different time-resolved pH profiles measured in the two boreholes suggests the development of perennial biomass that triggers calcite dissolution. Moreover, the presence of biomass seems to be correlated with the permeability and vertical connectivity at the meter-scale. It is speculated that the mechanism could be self-activated because the microbiological activity induces calcite dissolution and tends to increase porosity and permeability that favors biomass development.
ISSN: 0883-2927

hal-00937665
https://hal.archives-ouvertes.fr/hal-00937665
DOI : 10.1016/j.apgeochem.2013.09.011

Éditeur(s) : HAL CCSD Springer Verlag/EDP Sciences
Résumé : International audience
Context: Woodcutting is a very old technology but scientific research is scarce on the subject. In the last 50 years much work on basic mechanisms as well as industrial processes has been done in France. Aims: The specific nature of wood introduces strong differences between wood and metal cutting processes. The paper focuses on French teams' contributions. Results: The basic aspects of the tool–material interaction for different basic modes in woodcutting are highlighted. In primary conversion such as sawing, veneer cutting or green wood chipping, huge progress comes from automation and the possibility of linking the process to log and product quality through new sensors. In secondary processing much has been done on the links between the cutting process, surface qualification and the properties of these surfaces for further processing, such as gluing or coating. Tool wear depends on the cutting process, timber quality, and species. Trade-offs are required in tool technology and coating technologies may improve tool life. Conclusion: A large amount of knowledge and innovation has come from 50 years of worldwide research effort, with France being particularly active in this period. The transfer of skills from metals cutting industry was often a key, but much is needed to move closer to both metal cutting sector and woodcutting skills among craftsmen.
ISSN: 1286-4560

hal-01135156
https://hal.archives-ouvertes.fr/hal-01135156
https://hal.archives-ouvertes.fr/hal-01135156/document
https://hal.archives-ouvertes.fr/hal-01135156/file/Wood_machining_focus_French_research_Thibaut_al_2015.pdf
DOI : 10.1007/s13595-015-0460-2

Éditeur(s) : HAL CCSD
Résumé : International audience
The social networks high level rise led many organizations to invest in information and communication digital technologies (ICDT). Innovation by use theory is convened here to analyze the informational practices taking place in cultural institutions. We try to show in what logics using those technologies linked at digital social networks by certain institutions leaders recalled users influential divert meditational practices and profile a new digital identity of the professional as well as the library assigned role.
L’essor des réseaux sociaux a conduit de nombreuses organisations à investir dans les technologies numériques d’information communication (TNIC). Le modèle théorique de l’innovation par l’usage est ici convoqué pour analyser les pratiques informationnelles qui prennent place dans des institutions à caractère culturel et dans lesquelles quelques activités de médiations articulées autour des usages des réseaux sociaux numériques ont été repérées. Nous tentons de montrer en quoi les logiques d’usages de ces technologies - réseaux sociaux numériques incarnées par certaines institutions leaders, usagers influents déconstruisent les pratiques de médiations et profilent une nouvelle identité numérique aussi bien du professionnel que durôle assigné par convention aux bibliothèques.
Les écosystèmes numériques et la démocratisation informationnelle : Intelligence collective, Développement durable, Interculturalité, Transfert de connaissances
Schoelcher, France

hal-01258338
https://hal.univ-antilles.fr/hal-01258338
https://hal.univ-antilles.fr/hal-01258338/document
https://hal.univ-antilles.fr/hal-01258338/file/Samuel%20TIETSE.pdf

Éditeur(s) : HAL CCSD BMJ Publishing Group
Résumé : International audience
BACKGROUND: The association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously, it is difficult to assess the role of individual substances. OBJECTIVES: The present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos. METHODS: We analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case-control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression. RESULTS: After analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters. CONCLUSIONS: Organic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk
ISSN: 1351-0711

hal-01282444
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01282444
DOI : 10.1136/oemed-2015-103177
PUBMED : 26911986

Éditeur(s) : HAL CCSD
Résumé : International audience
To study the associations between occupation, industry and prostate cancer risk in Guadeloupe, a high incidence area. Incident cases of prostate cancer (707 cases) and 722 population controls were included. Information on lifetime occupational history and other potential risk factors was collected by interview. Logistic regression was used to estimate adjusted odds-ratios (OR) and their 95% confidence intervals (CI). A significantly decreased risk was observed in farmers (OR=0.5; CI 0.4-0.7), whereas marginally elevated ORs were found for farm workers, especially in sugarcane and banana farming. Banana plantation workers had been exposed to chlordecone, an estrogenic insecticide previously found to be associated with prostate cancer risk in this population. Significantly increased risks of prostate cancer were found in stock clerks (OR=2.7; CI 1.0-7.2), fishermen (OR=2.0; CI 1.0-4.0), mail distribution clerks (OR=7.7; CI 1.7-34.4) and electricians employed for more than 20 years (OR=4.0; CI 1.0-15.8), as well as in public administration (OR=1.8; CI 1.2-2.9), retail trade (OR=2.6; CI 1.1-6.0) and manufacture of food products (OR=2.0; CI 1.1-3.9), particularly sugar (OR=13.2; IC 1.6-108). Non-significantly elevated ORs were also seen for construction workers and transport equipment operators. Although the overall findings suggest that occupational factors have only a limited role in prostate cancer aetiology, elevated risks of prostate cancer were found in several occupations or industries. Exposure to pesticides, solvents, traffic-related air pollution, low physical activity, whole-body vibration may explain some of these increased risks.
Challenges for Occupational Epidemiology in the 21st Century EPICOH 2014
Chicago, United States

hal-01118558
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118558
DOI : 10.1136/oemed-2014-102362.312
PUBMED : 25018167

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Sensitive instruments like strainmeters and tiltmeters are necessary for measuring slowly varying low amplitude Earth deformations. Nonetheless, laser and fibre interferometers are particularly suitable for interrogating such instruments due to their extreme precision and accuracy. In this paper, a practical design of a simple pendulum borehole tiltmeter based on laser fibre interferometric displacement sensors is presented. A prototype instrument has been constructed using welded borosilicate with a pendulum length of 0.85 m resulting in a main resonance frequency of 0.6 Hz. By implementing three coplanar extrinsic fibre Fabry-Perot in-terferometric probes and appropriate signal filtering, our instrument provides tilt measurements that are insensitive to parasitic deformations caused by temperature and pressure variations. This prototype has been installed in an underground facility (Rustrel, France) where results show accurate measurements of Earth strains derived from Earth and ocean tides, local hydro-logic effects, as well as local and remote earthquakes. The large dynamic range and the high sensitivity of this tiltmeter render it an invaluable tool for numerous geophysical applications such as transient fault motion, volcanic strain and reservoir monitoring.
ISSN: 0956-540X

hal-01265967
https://hal.archives-ouvertes.fr/hal-01265967
https://hal.archives-ouvertes.fr/hal-01265967/document
https://hal.archives-ouvertes.fr/hal-01265967/file/HCS1.pdf
DOI : 10.1093/gji/ggv358

Éditeur(s) : HAL CCSD
Résumé : Neotropical forests shelter an astonishing and underrated biodiversity. The integrity and stability of these natural ecosystems are threatened by human-induced environmental changes. Therefore, highlighting the determinants of ecosystem functioning, be they natural or anthropogenic, is a daunting but paramount scientific challenge. The intrinsic complexity of highly diversified ecosystems arouses both conceptual and logistical difficulties, which we handle, by manipulating tiny ecosystems, the tank bromeliads. The leaves of tank bromeliads form wells that hold rainwater and intercept leaf litter, allowing for a simple invertebrate aquatic community to thrive. These plants can be exhaustively sampled, are naturally replicated, and widely distributed.From local to biogeographic scales, this thesis aims at understanding how these communities respond to the natural heterogeneity of Amazonian forests, and at predicting the impacts of human-induced disturbances on the structure and functioning of these communities, using in situ and lab experiments. Particular focus is attributed to the influence of some aspects of climate changes (e.g., warming, and various precipitations scenarios) on individual physiology, behavior, and trophic interactions.
Les forêts néotropicales accueillent une importante biodiversité encore méconnue. L’intégrité des écosystèmes naturels est menacée par les changements environnementaux (e.g., réchauffement climatique, destruction des habitats), par conséquent, identifier les facteurs structurants, naturels et anthropiques, du fonctionnement des écosystèmes, représente un défi scientifique crucial. L’inhérente complexité de ces milieux diversifiés pose de nombreux problèmes conceptuels et logistiques comme un échantillonnage exhaustif et/ou l’identification des espèces. Les broméliacées à réservoirs sont des écosystèmes miniatures adéquats pour pallier ces difficultés, car elles retiennent de l’eau de pluie et accumulent de la matière organique au creux de leurs feuilles, permettant ainsi de supporter des réseaux trophiques simples d’invertébrés aquatiques. Elles peuvent être échantillonnées exhaustivement, ont une forte abondance locale, et une large aire de répartition. De l’échelle locale à biogéographique, les travaux de cette thèse visent d’abord à comprendre comment ces communautés se structurent en réponse à l’hétérogénéité naturelle des forêts amazoniennes (e.g., ouverture de la canopée, fluctuations climatiques saisonnières), puis tente de prédire, par le biais d’expérimentations in situ et au laboratoire les réponses structurelles et fonctionnelles de ces communautés à divers scénarios de changement climatique. Une attention particulière a été portée sur l’impact de la température et des précipitations sur la physiologie et le comportement d’espèces clefs, et sur les interactions trophiques au sein des communautés.
https://tel.archives-ouvertes.fr/tel-01405025

NNT : 2015YANE0003
tel-01405025
https://tel.archives-ouvertes.fr/tel-01405025
https://tel.archives-ouvertes.fr/tel-01405025/document
https://tel.archives-ouvertes.fr/tel-01405025/file/These-DEZERALD-Diffusion.pdf

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Probabilistic seismic hazard analyses (PSHA) are commonly based on frequency magnitude statistics from 50-100 yearlong earthquake catalogs, assuming that these statistics are representative of the longer-term frequency of large earthquakes. We test an alternative PSHA approach in continental western Canada, including adjacent areas of northwestern U. S. A., using regional strain rates derived from 179 Global Positioning System (GPS) horizontal velocities. GPS strain rates are converted to earthquake statistics, seismic moment rates, and ground shaking probabilities in seismic source zones using a logic-tree method for uncertainty propagation. Median GPS-based moment rates and shaking estimates agree well with those derived from earthquake catalogs in only two zones (Puget Sound and mid-Vancouver Island). In most other zones, median GPS-based moment rates are 6-150 times larger than those derived from earthquake catalogs (shaking estimates 2-5 times larger), although the GPS-based and catalog estimates commonly agree within their 67% uncertainties. This discrepancy may represent an under-sampling of long-term moment rates and shaking by earthquake catalogs in some zones; however a systematic under-sampling is unlikely over our entire study area. Although not demonstrated with a high confidence level, long-term regional aseismic deformation may account for a significant part of the GPS/catalog discrepancy and, in some areas, represent as much as 90% of the total deformation budget. In order to integrate GPS strain rates in PSHA models, seismic versus aseismic partitioning of long-term deformation needs to be quantified and understood in terms of the underlying mechanical processes.
ISSN: 0148-0227

hal-00689004
https://hal.archives-ouvertes.fr/hal-00689004
DOI : 10.1029/2011JB008213

Éditeur(s) : HAL CCSD
Résumé :   Diffusion du document : INRA Antilles-Guyane, UMR ECOFOG, F97387 Kourou, Guyane (France) Diplôme : DEA
il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION
This work on tropic al humid forest of Paracou includes 16 permanent sample plots covering a total surface of 119 hectares. Ten hectares of them are taken up by floodplains which characteristic is a continuous no-deep underground water level with phases of strong surface water logging. Three items have been studied : (i) Checking that during dry season the maps of the underground water level including its limits are reliable, (ii) Characterising the most suitable ecological niches for certain species, (iii) Additional updating the floodplains characterisation by precisely analysing the chemical soil content as well as the physiological reaction of the Symphonia Globulifera . Checking the underground water level in dry season enabled to put down to a quite good measurement reliability by GIS. The classification ecological of species proposed in this work is based on the relative density in floodplain and drain soil very similar to that which concerns a surface located ten or more kilometres further. This lets us assess that this classification is of a good reliability as long as the climate conditions are quite similar to ours in Paracou. Furthermore the presence of pneumatophores in the Symphonia Globulifera is a good biological criterion as long as it shows a long time ground moisture saturation. By analysing the life litter and the soil we mentioned that the leaf content and the soil content indicate a better nutritional value (phosphorus, calcium and potassium) in the floodplains. For phosphorus the relation between the life litter and the soil results put forward that the Olsen method gives a better explanation of the real phosphorus availability for the trees.
Le dispositif de recherche sur la forêt tropicale humide de Paracou est composé de 16 parcelles permanentes couvrant au total 119 ha, dont 10 ha sont occupés par des bas-fonds, caractérisés par l'existence permanente d'une nappe peu profonde et par des périodes de fort engorgement en surface. Notre étude avait trois objectifs : (i) vérifier la fiabilité des cartes de la profondeur de nappe en saison sèche, qui délimitent ces bas-fonds, (ii) caractériser les préférences écologiques de quelques espèces et (iii) compléter la caractérisation des bas-fonds par l'analyse de la richesse chimique du sol et l'étude de la réaction physiologique du Symphonia globulifera. La vérification sur la profondeur de nappe en saison sèche a montré que les imprécisions des cartes étaient d'ampleur limitée, sans incidence forte par rapport à l'ensemble des données. Le classement écologique des espèces proposé dans cette étude, basé sur leurs densités relatives dans les bas-fonds et hors des bas-fonds, est très similaire à celui présenté par une autre étude, dans un dispositif situé à plusieurs dizaines de kilomètres. Cela suggère que ce classement a une bonne validité, tant que les conditions climatiques ne diffèrent pas trop de celles rencontrées à Paracou. Par ailleurs, la présence des pneumatophores du Symphonia globulifera est un bon critère biologique signalant un engorgement hydrique prolongé du sol. Au niveau des analyses de la litière et du sol, les teneurs foliaires et les teneurs dans le sol semblent indiquer que la nutrition en phosphore, calcium et potassium est meilleure en bas-fonds. Au niveau de la méthode de mesure du phosphore assimilable, les relations entre les résultats de la litière et celles du sol suggèrent que la méthode d'Olsen rend mieux compte de la disponibilité effective du phosphore pour les arbres de la forêt tropicale humide que la méthode de Duchaufour.
https://hal.archives-ouvertes.fr/hal-01189229

hal-01189229
https://hal.archives-ouvertes.fr/hal-01189229
PRODINRA : 17050

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The analysis of field relationships between allochthonous crystalline slivers, ultramafic units and associated sedimentary cover in the high-pressure Schistes Lustrés units of northern Corsica allows reconstruction of the pre-orogenic architecture of a fossil Mesozoic Ocean-Continent Transition (OCT) of the Tethys basin. The studied area, encompassing the Serra di Pigno and Col de Téghime areas (Cap Corse) is composed of an assemblage of prealpine basement sheets made up of serpentinized mantle rocks, Permian gabbros and gneisses, locally associated with Paleozoic metabasites and micaschists. The sedimentary cover includes numerous intervals of calc-schists, marbles, quartzites, micaschists and dolomitic metabreccias yielding a great variety of lithostratigraphical successions. The metasedimentary sequences do not show affinities with the typical cover series of the Prépiémontais margin domains. This implies an origin from a more internal domain (oceanward) for the studied units. In addition, the sedimentary cover of the ultramafic basement units do not display the characters of the classical Alpine ophiolites but bear lithological features showing affinities with both continental and oceanic environments. We assume that the high variability of the sedimentary successions as well as the presence of a basement composed of continental and upper-mantle rocks is consistent with an origin at an OCT. The acidic basement slivers are regarded as former extensional allochthons of continental crust abandoned during breakup on a newly exhumed seafloor of peridotite composition. Such extensional allochthons, will then logically constitute the most internal continental slices buried at great depth during Alpine subduction. This work shows that a lot has to be expected from a revision of the Schistes Lustrés lithostratigraphy in the light of the new concepts of the evolution of the OCT domains.
ISSN: 0040-1951

hal-00795578
https://hal.archives-ouvertes.fr/hal-00795578
DOI : 10.1016/j.tecto.2012.06.013