Éditeur(s) : HAL CCSD American Medical Association (AMA)
Résumé : International audience
IMPORTANCE Although frequently used in treating intensive care unit (ICU) patients with sepsis, empirical antifungal therapy, initiated for suspected fungal infection, has not been shown to improve outcome. OBJECTIVE To determine whether empirical micafungin reduces invasive fungal infection (IFI)-free survival at day 28. DESIGN, SETTING, AND PARTICIPANTS Multicenter double-blind placebo-controlled study of 260 nonneutropenic, nontransplanted, critically ill patients with ICU-acquired sepsis, multiple Candida colonization, multiple organ failure, exposed to broad-spectrum antibacterial agents, and enrolled between July 2012 and February 2015 in 19 French ICUs. INTERVENTIONS Empirical treatment with micafungin (100mg, once daily, for 14 days) (n = 131) vs placebo (n = 129). MAIN OUTCOMES AND MEASURES The primary end pointwas survival without proven IFI 28 days after randomization. Key secondary end points included new proven fungal infections, survival at day 28 and day 90, organ failure, serum (1-3)-beta-D-glucan level evolution, and incidence of ventilator-associated bacterial pneumonia. RESULTS Among 260 patients (mean age 63 years; 91 [35%] women), 251 (128, micafungin group; 123, placebo group) were included in the modified intent-to-treat analysis. Median values were 8 for Sequential Organ Failure Assessment (SOFA) score, 3 for number of Candida-colonized sites, and 99 pg/mL for level of (1-3)-beta-D-glucan. On day 28, there were 82 (68%) patients in the micafungin group vs 79 (60.2%) in the placebo group who were alive and IFI free (hazard ratio [HR], 1.35 [95% CI, 0.87-2.08]). Results were similar among patients with a (1-3)-beta-D-glucan level of greater than 80 pg/mL (n = 175; HR, 1.41 [95% CI, 0.85-2.33]). Day-28 IFI-free survival in patients with a high SOFA score (> 8) was not significantly different when compared between the micafungin vs placebo groups (HR, 1.69 [95% CI, 0.96-2.94]). Use of empirical micafungin decreased the rate of new invasive fungal infection in 4 of 128 patients (3%) in the micafungin group vs placebo (15/123 patients [12%]) (P =.008). CONCLUSIONS AND RELEVANCE Among nonneutropenic critically ill patients with ICU-acquired sepsis, Candida species colonization at multiple sites, and multiple organ failure, empirical treatment with micafungin, compared with placebo, did not increase fungal infection-free survival at day 28.
ISSN: 0098-7484

hal-01405822
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01405822
DOI : 10.1001/jama.2016.14655
PUBMED : 27706483

Éditeur(s) : HAL CCSD
Résumé : Anopheles darlingi, one of the main malaria vectors in the Neotropics, is widely distributed in French Guiana, where malaria remains a major public-health problem. Elucidation of the relationships between the population dynamics of An. darlingi and local environmental factors would appear to be an essential factor in the epidemiology of human malaria in French Guiana and the design of effective vector-control strategies. In a recent investigation, longitudinal entomological surveys were carried out for 2-4 years in one village in each of three distinct endemic areas of French Guiana. Anopheles darlingi was always the anopheline mosquito that was most frequently caught on human bait, although its relative abundance (as a proportion of all the anophelines collected) and human biting rate (in bites/person-year) differed with the study site. Seasonality in the abundance of human-landing An. darlingi (with peaks at the end of the rainy season) was observed in only two of the three study sites. Just three An. darlingi were found positive for Plasmodium (either P. falciparum or P. vivax) circumsporozoite protein, giving entomological inoculation rates of 0*0-8*7 infectious bites/person-year. Curiously, no infected An. darlingi were collected in the village with the highest incidence of human malaria. Relationships between malaria incidence, An. darlingi densities, rainfall and water levels in the nearest rivers were found to be variable and apparently dependent on land-cover specificities that reflected the diversity and availability of habitats suitable for the development and reproduction of An. darlingi.
Annals of Tropical Medicine and Parasitology / Annals of Tropical Medicine & Parasitology

pasteur-00583507
https://hal-riip.archives-ouvertes.fr/pasteur-00583507
DOI : 10.1179/136485911X12899838683322
PUBMED : 21396247

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
The Miradouro da Lua cliffs, which are 60 km south of Luanda, record the building and uplift of the late Neogene Palaeo-Cuanza delta. The detailed study of the sedimentary architecture and stacking pattern permitted separation of the pile into five depositional units bounded by erosional surfaces and characterised by separate facies associations (genetic sequences = units in this paper). At the base of the series, aeolian deposits (Unit 1) mark the development of a possible coastal desert during the late Miocene aridification. The major Pliocene sea-level rise (Transgressive Systems Tract) led to the drowning of the continental platform into a discrete shoreface-foreshore sequence (Unit 2), followed by an expanded deltaic sequence (Unit 3) that represents the main outcrop of the area. The sedimentary fabric of this prograding wedge during the Highstand Systems Tract reveals laterally stacked pluri-hectometic mouth bars built by the abrupt switching of a bird-foot delta during the Pliocene highstand. The clinoforms are deeply incised by submarine gullies filled both by periodic river-driven turbidite and tidal currents (Unit 4) during the coeval growing of the delta. The topset of the prograding wedge and associated gullies infill is truncated by an overall erosional unconformity that marks the widespread development of an extensive braid-delta system (Unit 5) during the lower Pleistocene sea-level drop (Lowstand Systems Tract). The last 6 m of the Braid-delta unit is overprinted by a ferallitic profile, forming the surface of the plateau and indicating long-term subaerial exposure and weathering processes consistent with the maximum warming of the middle to late Pleistocene interglacial periods. The successive abrupt shifts of the depositional systems through the sedimentary pile indicate a high-amplitude sea level amplified by major coastal uplifts and the reorganisation of the fluvial network. In this context, the palaeo-Cuanza prograding wedge signals the westward tilting and 60 m total uplift of the coastal plain during the Pliocene. A new uplift pulse by differential tilt and slope increase is deduced from the widespread development of the braid-delta complex during the early Pleistocene. The last tectonic event corresponds to the 80- to 100-m uplift and ferallitic paedogenesis during the middle to late Pleistocene interglacial stages.
ISSN: 0899-5362

hal-01053716
https://hal.archives-ouvertes.fr/hal-01053716
DOI : 10.1016/j.jafrearsci.2014.01.013

Éditeur(s) : HAL CCSD American Physical Society
Résumé : International audience
Absolute M-shell x-ray production cross sections have been measured and calculated for Au and Bi for electron incident energies from close to the ionization threshold up to 38 keV. The experimental cross sections were deduced from M alpha x-ray intensities emitted from ultrathin Au and Bi samples deposited on self-supporting C films. The measurements were performed on an electron microprobe using several wavelength-dispersive spectrometers. The x-ray production cross sections were also evaluated theoretically using ionization cross sections calculated from the plane-wave and the distorted-wave Born approximations. Experimental results are compared with the calculated cross sections and also with the results of two analytical formulas widely used in many applications. Good agreement is found between the measured cross sections and the predictions from the distorted-wave Born approximation, which indicates that this approximation is suited for the calculation of M-shell ionization cross sections of heavy elements.
ISSN: 1050-2947

hal-00411432
https://hal.archives-ouvertes.fr/hal-00411432
DOI : 10.1103/PhysRevA.78.022704

Éditeur(s) : HAL CCSD
Résumé : International audience
L’asthme chez les agriculteurs est un phénomène contradictoire, puisque le milieu agricole est à la fois décrit comme étant à risque d’asthme inflammatoire et comme étant protecteur d’asthme allergique.Une étude ancillaire d’AIRBAg (Analyse Incidence et facteurs de Risque de BPCO Agricole) a permis l’analyse de 603 agriculteurs laitiers d’Ille et Vilaine et du Morbihan, afin de définir la prévalence de l’asthme dans cette population, et d’identifier des facteurs de risque et/ou protecteurs de la maladie asthmatique. Pour cela, les patients asthmatiques ont été comparés au reste de la population agricole selon des critères cliniques, professionnels et environnementaux.Nous avons mis en évidence une prévalence de 6 % d’asthme. Aucun facteur professionnel n’était significativement associé au risque d’être asthmatique. Il semble que les facteurs protecteurs principaux soient pour la plupart retrouvés dans notre population d’asthmatique, hormis l’allaitement maternel, présent chez seulement un quart des patients.La prévalence de l’asthme dans notre cohorte d’agriculteur est donc semblable à celle de la population générale, et l’asthme est la maladie obstructive la plus fréquente dans l’échantillon. Aucun facteur professionnel n’a été identifié comme facteur de risque.
Revue des Maladies Respiratoires
Lille, France

hal-01122830
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122830
DOI : 10.1016/j.rmr.2014.10.695

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

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

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
BACKGROUND: Public and scientific concerns about the social gradient of end-stage renal disease and access to renal replacement therapies are increasing. This study investigated the influence of social inequalities on the (i) access to renal transplant waiting list, (ii) access to renal transplantation and (iii) patients' survival. METHODS: All incident adult patients with end-stage renal disease who lived in Bretagne, a French region, and started dialysis during the 2004-2009 period were geocoded in census-blocks. To each census-block was assigned a level of neighborhood deprivation and a degree of urbanization. Cox proportional hazards models were used to identify factors associated with each study outcome. RESULTS: Patients living in neighborhoods with low level of deprivation had more chance to be placed on the waiting list and less risk of death (HR = 1.40 95%CI: [1.1-1.7]; HR = 0.82 95%CI: [0.7-0.98]), but this association did not remain after adjustment for the patients' clinical features. The likelihood of receiving renal transplantation after being waitlisted was not associated with neighborhood deprivation in univariate and multivariate analyses. CONCLUSIONS: In a mixed rural and urban French region, patients living in deprived or advantaged neighborhoods had the same chance to be placed on the waiting list and to undergo renal transplantation. They also showed the same mortality risk, when their clinical features were taken into account
ISSN: 1932-6203

hal-01305481
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01305481
DOI : 10.1371/journal.pone.0153431
PUBMED : 27082113

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
ETHNOPHARMACOLOGICAL RELEVANCE: Cutaneous leishmaniasis is a neglected disease with a high incidence in French Guiana, mainly in the middle and upper Oyapock basin, where Amerindian and some Brazilian people live. The main goals of this work were (i) to assess the knowledge about leishmaniasis in the different populations of the middle and upper Oyapock basin, (ii) to study the therapeutic strategies adopted by people affected by leishmaniasis and (iii) to document the use of phytotherapeutic remedies for leishmaniasis. Knowledge, attitudes and practices (K.A.P.) related to this disease and its treatments have been studied according to cultural group and geographical settlement. Within the Wayãpi group, the evolution of the knowledge of phytoremedies over the last 20 years has been characterised by literature-based comparisons. MATERIALS AND METHODS: A total of 144 questionnaires were administered in all the villages of the upper Oyapock and Camopi basins. Correspondence analyses were used for multivariate analysis. Plant species were identified at the Cayenne Herbarium (CAY). RESULTS: The biomedical concept of leishmaniasis correlates well with the Teko and Wayãpi concepts of kalasapa and kalasapau. Although the vector of this disease was not correctly identified, the most commonly cited aetiology (74.5%) was vector-borne, and related epidemiological schemes correlate well with the one encountered in French Guiana. Theoretically and practically, health centres were the most commonly used resource for diagnostic in instances of leishmaniasis infection (65.9%), independently of the patient's cultural group, along with the use of pharmaceutical drugs (85.3%). Pharmaceuticals were commonly utilised despite the frequent (51.5%) use of phytotherapeutic remedies, alone or in combination with drugs. The most cited medicinal plant species for the treatment of leishmaniasis included Eleutherine bulbosa (Mill.) Urb. (Iridaceae, cited 14 times), Euterpe oleracea Mart. (Arecaceae, 9), Cecropia obtusa Trecul (Cecropiaceae, 8), Jatropha curcas L. (Euphorbiaceae, 7), Ceiba pentandra (L.) Gaertn. (Bombacaceae, 6) and Carica papaya L. (Caricaceae, 6). Multiple correspondence analyses demonstrated that the species used in leishmaniasis remedies are more prone to vary by the user's place of residence than by their cultural origin, which indicates that exchange of knowledge about leishmaniasis remedies has occurred across different cultural groups. Literature-based comparisons between the remedies for leishmaniasis used by the Wayãpi during the 1980s showed a striking evolution, both in terms of diversity of species and number of plants used. The large number of species shared with other Guianese groups argues for intercultural exchange and may explain the majority (57.1%) of the newly used species highlighted in our study. CONCLUSIONS: Leishmaniasis is a well-known disease in the studied area. Phytotherapeutic treatments are still in use, although they are not the main source of remedies, and should undergo pharmacological studies to evaluate their potential therapeutic value.
ISSN: 0378-8741

pasteur-00634597
https://hal-riip.archives-ouvertes.fr/pasteur-00634597
DOI : 10.1016/j.jep.2011.07.044
PUBMED : 21816216

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Analysis of continuous seismic data recorded by a dense passive seismological network (Hi-CLIMB) installed across the Himalayas reveals strong spatial and temporal variations in the ambient seismic energy produced at high frequencies (>1 Hz). From June to September 2003, the high-frequency seismic noise is observed to increase up to 20 dB (relative to (m/s)(2)/Hz) for all the stations located along a steep 30-km-long narrow and deeply incised channel of the Trisuli River, a major trans-Himalayan river. The early summer increase in high-frequency energy is modulated by a 24-h periodicity where the minimum of seismic noise level is reached around noon and the maximum is reached late in the evening. A detailed study of seismic noise amplitude reveals a clear correlation with both regional meteorological and hydrological data along the Trisuli River. Seasonal increase in ambient noise coincides with the strong monsoon rainfall and a period of rapid melting of snow and ice in the high elevations. The observed 24-h cyclicity is consistent with the daily fluctuation of the precipitation and river discharge in the region. River-induced seismic noise is partly generated by stream turbulence, but this mechanism fails to explain the observed clockwise hysteresis of seismic noise amplitude versus water level. This pattern is better explained if a significant part of the observed seismic noise is caused by ground vibrations generated by bed load transport. This points out the potential of using background seismic noise to quantify in continuous river bed load and monitor its spatial variations, which remain difficult with classical approaches.
ISSN: 2169-9313

hal-00412170
https://hal.archives-ouvertes.fr/hal-00412170
DOI : 10.1029/2007JB005034

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Author Summary Leptospirosis is a common disease in tropical regions around the world. It is caused by a bacteria excreted in environmental waters by mammals, especially rodents, through their urine. Leptospirosis has symptoms similar to other tropical diseases, including dengue fever, and early laboratory diagnosis is crucial to provide both appropriate treatments for patients and rapid control measures when an outbreak occurs. In 2011, we undertook a study to determine the incidence of leptospirosis in two territories (Guadeloupe and Martinique) in the French West Indies by establishing a surveillance network and implementing new diagnostic assays in order to ensure an exhaustive diagnostic analysis. We concluded that leptospirosis was previously significantly under-reported in the French West Indies and we recommended: 1- access to these new diagnostic tests for the entire population for a better detection of leptospirosis patients and, 2- the implementation of an integrated surveillance, alert and prevention system for the disease in this region. Our findings had raised the awareness of this neglected disease in the French West Indies and, as another consequence; new diagnostic tests are now reimbursed by the social security insurance in France
ISSN: 1935-2727

Droits : http://creativecommons.org/licenses/by/
hal-01324701
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01324701
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01324701/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01324701/file/journal.pntd.0004668.pdf
DOI : 10.1371/journal.pntd.0004668

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Technologies for wireless telecommunication systems using millimeter waves (MMW) will be widely deployed in the near future. Forthcoming applications in this band, especially around 60 GHz, are mainly developed for high data-rate local and body-centric telecommunications. At those frequencies, electromagnetic radiations have a very shallow penetration into biological tissues, making skin keratinocytes, and free nerve endings of the upper dermis the main targets of MMW. Only a few studies assessed the impact of MMW on neuronal cells, and none of them investigated a possible effect on neuronal differentiation. We used a neuron-like cell line (PC12), which undergoes neuronal differentiation when treated with the neuronal growth factor (NGF). PC12 cells were exposed at 60.4 GHz for 24 h, at an incident power density averaged over the cell monolayer of 10 mW/cm2. Using a large scale cell-by-cell analysis based on high-content screening microscopy approach, we assessed potential effects of MMW on PC12 neurite outgrowth and cytoskeleton protein expression. No differences were found in protein expression of the neuronal marker β3-Tubulin nor in internal expression control β-Tubulin. On the other hand, our data showed a slight increase, although insignificant, in neurite outgrowth, induced by MMW exposure. However, experimental controls demonstrated that this increase was related to heating
ISSN: 0304-3940

hal-01281481
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281481
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281481/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281481/file/Effects%20of%2060-GHz%20Millimeter%20Waves%20on%20Neurite.pdf
DOI : 10.1016/j.neulet.2016.02.038

Éditeur(s) : HAL CCSD Wiley
Résumé :  
The lack of information on the ways seasonal drought modifies the CO2 exchange between Neotropical rainforest ecosystems and the atmosphere and the resulting carbon balance hinders our ability to precisely predict how these ecosystems will respond as global environmental changes force them to face increasingly contrasting conditions in the future. To address this issue, seasonal variations in daily net ecosystem productivity (NEPd) and two main components of this productivity, daily total ecosystem respiration (REd) and daily gross ecosystem productivity (GEPd), were estimated over 2 years at a flux tower site in French Guiana, South America (511605400N, 5215404400W). We compared seasonal variations between wet and dry periods and between dry periods of contrasting levels of intensity (i.e. mild vs. severe) during equivalent 93-day periods. During the wet periods, the ecosystem was almost in balance with the atmosphere (storage of 9.0 gCm_2). Seasonal dry periods, regardless of their severity, are associated with higher incident radiation and lower REd combined with reduced soil respiration associated with low soil water availability. During the mild dry period, as is normally the case in this region, the amount of carbon stored in the ecosystem was 32.7 gCm_2. Severe drought conditions resulted in even lower REd, whereas the photosynthetic activity was only moderately reduced and no change in canopy structure was observed. Thus, the severe dry period was characterized by greater carbon storage (64.6 gCm_2), emphasizing that environmental conditions, such as during a severe drought, modify the CO2 exchange between Neotropical rainforest ecosystems and the atmosphere and potentially the resulting carbon balance.
ISSN: 1354-1013

hal-01032067
https://hal.archives-ouvertes.fr/hal-01032067
DOI : 10.1111/j.1365-2486.2008.01610.x

Éditeur(s) : HAL CCSD Wiley
Résumé : The intensification of the hydrological cycle, with an observed and modeled increase in drought incidence and severity, underscores the need to quantify drought effects on carbon cycling and the terrestrial sink. FLUXNET, a global network of eddy covariance towers, provides dense data streams of meteorological data, and through flux partitioning and gap filling algorithms, estimates of net ecosystem productivity (FNEP), gross ecosystem productivity (P), and ecosystem respiration (R). We analyzed the functional relationship of these three carbon fluxes relative to evaporative fraction (EF), an index of drought and site water status, using monthly data records from 238 micrometeorological tower sites distributed globally across 11 biomes. The analysis was based on relative anomalies of both EF and carbon fluxes and focused on drought episodes by biome and climatic season. Globally P was ≈50% more sensitive to a drought event than R. Network-wide drought-induced decreases in carbon flux averaged −16.6 and −9.3 g C m−2 month−1 for P and R, i.e., drought events induced a net decline in the terrestrial sink. However, in evergreen forests and wetlands drought was coincident with an increase in P or R during parts of the growing season. The most robust relationships between carbon flux and EF occurred during climatic spring for FNEP and in climatic summer for P and R. Upscaling flux sensitivities to a global map showed that spatial patterns for all three carbon fluxes were linked to the distribution of croplands. Agricultural areas exhibited the highest sensitivity whereas the tropical region had minimal sensitivity to drought. Combining gridded flux sensitivities with their uncertainties and the spatial grid of FLUXNET revealed that a more robust quantification of carbon flux response to drought requires additional towers in all biomes of Africa and Asia as well as in the cropland, shrubland, savannah, and wetland biomes globally.
ISSN: 1354-1013

hal-01032076
https://hal.archives-ouvertes.fr/hal-01032076
DOI : 10.1111/j.1365-2486.2009.01991.x

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The dating of alluvial landforms by cosmogenic nuclides requires distinguishing the pre-deposition inheritance from the post-deposition history of the clasts in the studied marker. Moreover, estimating catchment-scale erosion rates from the concentrations of cosmogenic nuclides in active alluvia requires a good knowledge of the local/regional relationships between rock exhumation and transport through space and time. This is still poorly known for timescales of tens of thousand years. In order to document the evolution of clast exhumation and transport rates through time, we analyze in situ 10Be concentrations in boulders and cobbles from hillslopes to outlet of an arid mountainous catchment located in Gobi-Altay, Mongolia, strongly affected by global climatic changes during the Pleistocene-Holocene period. Samples were collected on bedrock, abandoned alluvial deposits, active colluvia and alluvia. Our results show a large 10Be scattering in the active river bed, consistent with a low and discontinuous catchment erosion rate dominated by mass wasting and fluvial incision. On the contrary, pre-exposure signal within abandoned terraces is much more homogeneous, consistent with climatic pulses responsible of strong erosional events on hillslopes and rapid fluvial transport. These results show that exhumation/transport processes at the catchment scale vary in style and intensity through time as a consequence of climatic oscillations. The occurrence of abrupt climatic changes during short periods of time recorded by 10Be concentrations in abandoned alluvia raise questions about the temporal applicability of catchment erosion rates derived from cosmogenic nuclide concentrations measured in sediments of active rivers. On the other hand, strong and short erosion events limit and homogenize the pre-exposure 10Be signal in associated deposits like debris-flows, making them particularly suitable markers for dating in active tectonic and paleoclimatic studies.
ISSN: 0169-555X

hal-00626702
https://hal.archives-ouvertes.fr/hal-00626702
https://hal.archives-ouvertes.fr/hal-00626702/document
https://hal.archives-ouvertes.fr/hal-00626702/file/GEOMOR-2485R1_corrected.pdf
DOI : 10.1016/j.geomorph.2011.07.023

Éditeur(s) : HAL CCSD
Résumé : Patagonia is well known for spectacular occurrences of a variety of glacial-derived landforms and deposits and for a long history of ancient glaciations. In this paper, we first review the diverse evidence that demonstrates the development of glacial-related sedimentary units within the Central Patagonian Cordillera since 7 Ma. Well preserved glacial landforrns at the top surface of mesetas on both sides of the Lago General Carrera-Buenos Aires are described: the Meseta Guenguel to the north, and the volcanic Meseta del Lago Buenos Aires to the south. The latter meseta corresponds to a 3 Ma old, morphologically inverted paleo-piedmont, based on Ar/Ar dates of the uppermost lava flows. It shows evidence of glacier advances to the NE direction. Over a distance of 20 km, glacial landforms observed by remote sensing data and digital elevation model define glacial tongues that were fed by the Cordillera reliefs to the west. These lobes are now beheaded from their westward sources along a morpho-structural corridor that bounds the Meseta del Lago Buenos Aires to the west. These remnants can be correlated with the oldest glacial landforms recognized north of Lago General Carrera-Buenos Aires, on the Meseta Guenguel that form the Chipanque moraine system. From these features it is concluded that the glacial drainage network of Central Patagonia has been strongly modified following relief inversion in response to erosion processes and to tectonic causes. Changes occurred after 3 Ma, from a smooth piedmont surface covered by an extensive ice mantle ending with ample glacial lobes, to the current series of deeply incised glacial valleys such as the Lago General Carrera-Buenos Aires depression. These new data bear important constraints on the history and development of the first glaciations in southern South America.
ANDEAN GEOLOGY

hal-00512682
https://hal.archives-ouvertes.fr/hal-00512682

Résumé : Ce travail de thèse intitulé «Evaluation de marqueurs génétiques du complexe Mycobacterium tuberculosis combinée à l'utilisation d'outils bioinformatiques: apport en épidémiologie et phylogénie de la tuberculose» a consisté en la sélection et l'évaluation de marqueurs minisatellites dans le cadre d'études épidémiologiques et phylogénétiques du bacille tuberculeux, Une première partie a ainsi porté sur l'épidémie de tuberculose en Guadeloupe, Martinique, et Guyane française ainsi que dans un pays continental à faible incidence de tuberculose, la Suède, Les résultats montrent les disparités existant entre les populations de patients tuberculeux des 3 départements français d'Amérique (DFA) ainsi que les similitudes génotypiques existant entre les bacilles tuberculeux. Par ailleurs le rôle majeur joué par les cas d'importation dans l'épidémie de tuberculose a été montré aussi bien dans les DFA qu'en Suède. Nous nous sommes ensuite intéressés à une utilisation optimale des minisatellites pour une meilleure discrimination de la famille génotypique émergeante « Beijing» circulant au Japon (Osaka, Kobe et Okinawa), ainsi qu'en Russie. Nous avons constaté le faible pouvoir discriminant du format classique 12-locus MIRU (Mycobacterial lnterspersed Repetitive Units) et proposons plusieurs nouvelles stratégies de typage basées plusieurs marqueurs minisatellites incluant certains locus hypervariables. Enfin, dans un troisième volet, nous avons étudié la diversité génétique des bacilles tuberculeux circulant actuellement dans la Caraïbe. laquelle semble refléter le passé historique très particulier de cette zone géographique au croisement d'une multitude de peuplements.
This thesis entitled "Evaluation of genetic markers of Mycobacterium tuberculosis combined with the use of bioinformatics tools: input for epidemiology and phylogeny of tuberculosis" deals with the selection and evaluation of minisatellite markers in the context of epidemiological and phylogenetic studies of the tubercle bacillus M. tuberculosis. The first part of the present work has focused on the epidemic of tuberculosis in Guadeloupe, Martinique and French Guiana as well as in a low incidence continental country, i.e Sweden. The results show differences between populations of TB patients in the three French Departments of America and similarities between the genotypes of the circulating tubercle bacilli Moreover, results highlight the important role played by imported cases for TB epidemic the three French departments of America and Sweden. ln a second part, minisatellite markers have been evaluated for a better discrimination of strains of the emerging genotype "Beijing" circulating in Japan (Osaka, Kobe and Okinawa), and Russia. A low discriminatory power of classical format 12-locus MIRU (Mycobacterial lnterspersed Repetitive Units) was observed and new combinations of minisatellites have also been proposed including hypervariable locus. Finally, the genetic diversity of tubercle bacilli circulating in the Caribbean was investigated which currently seem to reflect historical past of this very special region at the intersection of a multitude of cultures and peoples.

http://www.theses.fr/2011AGUY0427/document

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé : International audience
Background. Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression. Method. We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol. Results. We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47-2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04-1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94-1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81-1.32). Conclusions. Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.
ISSN: 0033-2917

hal-01560152
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560152
DOI : 10.1017/S003329171600355X
PUBMED : 28122650

Éditeur(s) : HAL CCSD ACSM
Résumé : International audience
A 26-yr-old man with sickle cell trait (SCT) suddenly lost visual acuity in the left eye after a cycling race in hot tropical environment. The cause was massive central retinal vein occlusion (CRVO) with hemorrhaging that rapidly worsened to neovascular glaucoma. Although medically treated, the eye is now marked by total retinal detachment. Cardiovascular function assessment shows no electrocardiographic abnormalities, no anomaly in the supra-aortic tree, and no evidence of structural heart disease. Although normal coagulation markers values (i.e., activated partial thromboplastin time, prothrombin time, fibrinogen concentration, antithrombin III, factor V, proteins C and S) were observed 2.5 months after the clinical event, a transesophageal echocardiogram performed few hours after the incident revealed the presence of four thrombi in the left atrium suggesting a postexercise hypercoagulable state at that time. Hemorheological measurements at distance of the events demonstrated high red blood cell rigidity at baseline. Therefore, marked blood rheological impairment and activation of the coagulation pathway in response to the heavy and prolonged cycling race could have promoted CRVO in this cyclist carrying SCT. These data suggest that SCT could be considered as a risk factor for significant ocular complications when severe exercise is performed and support the idea that SCT is a contributing factor in blood rheology and vascular dysfunctions.
Medicine & Science in Sports & exercise

Droits : info:eu-repo/semantics/OpenAccess
hal-00698572
https://hal.univ-antilles.fr/hal-00698572
https://hal.univ-antilles.fr/hal-00698572/document
https://hal.univ-antilles.fr/hal-00698572/file/Hedreville_et_al_revised_MSSE-D-08-00064R2.pdf
DOI : 10.1249/MSS.0b013e31818313d0

Résumé : Les études écologiques sont maintenant considérées comme prometteuses en raison de leur capacité à intégrer dans un même modèle autant des facteurs individuels que populationnels. Le mouvement récent de l’open data pourrait jouer un rôle important dans la pérennisation des démarches multidisciplinaires. Cette thèse montre que l’association des méthodes écologiques aux données publiques permet d’éclairer sous un angle nouveau des problématiques des maladies infectieuses.En Guyane Française, des méthodes écologiques dites de séries temporelles couplées aux données climatiques libres ont contribué à une meilleure compréhension du rôle du climat sur la dynamique de la transmission du paludisme, de la leishmaniose cutanée ainsi que de l’histoplasmose disséminée. L’utilisation de méthodes écologiques sur des données libres de la littérature scientifique concernant la séroprévalence toxoplasmose dans les populations humaines a permis d’identifier les principaux facteurs influençant le niveau de séroprévalence globale et indirectement du risque de toxoplasmose congénital associé. L’association de données onusiennes à des méthodes écologiques a permis de montrer qu’une prévalence importante d’ascaridiose est associée à une réduction par 10 de l’incidence du paludisme et l’impact significatif de la corruption sur la mortalité juvéno-infantile et sur les résistances aux anti-tuberculeux. Ces études montrent que l’association des méthodes écologiques aux données publiques permet d’éclairer sous un angle nouveau des problématiques des maladies infectieuses. Ce type d‘étude fournit la flexibilité nécessaire à l’étude des interactions complexes des nombreux déterminants de la santé.
Ecological studies are now considered promising because of their ability to integrate as well as individual factors than populational ones in the same model. The recent open data movement could play an important role in the sustainability of multidisciplinary approaches. The studies developed in this thesis show that the combination of ecological methods with open data could give original results in the issues of infectious diseases.In French Guiana, ecological methods called time series, coupled with open climate data, have contributed to a better understanding of the role of climate on the dynamics of malaria, cutaneous leishmaniasis and disseminated histoplasmosis. The use of ecological methods with open data from the scientific literature concerning toxoplasmosis seroprevalence in human populations has permitted to identify the main factors influencing the level of overall seroprevalence and indirectly to estimate the associated risk of congenital toxoplasmosis.The combination of UN data to ecological methods has shown that a high prevalence of ascariasis is associated with a reduction from 10 in the incidence of malaria and that corruption has a significant impact on child mortality and resistance to TB.The various studies developed in this thesis show that the combination of ecological methods to public data sheds a new light on the issues of infectious diseases. This type of study provides the flexibility to study the complex interactions of many determinants of health.

http://www.theses.fr/2011AGUY0482/document