Éditeur(s) : HAL CCSD Society for Range Management
Résumé : Grasslands and agroecosystems occupy one-third of the terrestrial area, but their contribution to the global carbon cycle remains uncertain. We used a set of 316 site-years of CO(2) exchange measurements to quantify gross primary productivity, respiration, and light-response parameters of grasslands, shrublands/savanna, wetlands, and cropland ecosystems worldwide. We analyzed data from 72 global flux-tower sites partitioned into gross photosynthesis and ecosystem respiration with the use of the light-response method (Gilmanov, T. G., D. A. Johnson, and N. Z. Saliendra. 2003. Growing season CO(2) fluxes in a sagebrushsteppe ecosystem in Idaho: Bowen ratio/energy balance measurements and modeling. Basic and Applied Ecology 4:167-183) from the RANGEFLUX and WORLDGRASSAGRIFLUX data sets supplemented by 46 sites from the FLUXNET La Thuile data set partitioned with the use of the temperature-response method (Reichstein, M., E. Falge, D. Baldocchi, D. Papale, R. Valentini, M. Aubinet, P. Berbigier, C. Bernhofer, N. Buchmann, M. Falk, T. Gilmanov, A. Granier, T. Grunwald, K. Havrankova, D. Janous, A. Knohl, T. Laurela, A. Lohila, D. Loustau, G. Matteucci, T. Meyers, F. Miglietta, J.M. Ourcival, D. Perrin, J. Pumpanen, S. Rambal, E. Rotenberg, M. Sanz, J. Tenhunen, G. Seufert, F. Vaccari, T. Vesala, and D. Yakir. 2005. On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm. Global Change Biology 11: 1.424-1439). Maximum values of the quantum yield (alpha = 75 mmol.mol(-1)), photosynthetic capacity (A(max) = 3.4 mg CO(2) . m(-2).s-1), gross photosynthesis (P(g,max) = 1.16 g CO(2) . m(-2).d(-1)), and ecological light-use efficiency (epsilon(ecol) = 59 mmol . mol(-1)) of managed grasslands and high-production croplands exceeded those of most forest ecosystems, indicating the potential of nonforest ecosystems for uptake of atmospheric CO(2). Maximum values of gross primary production (8 600 g CO(2) . m(-2).yr(-1)), total ecosystem respiration (7 900 g CO(2) . m(-2).yr(-1)), and net CO(2) exchange (2 400 g CO(2) . m(-2).yr(-1)) were observed for intensively managed grasslands and high-yield crops, and are comparable to or higher than those for forest ecosystems, excluding some tropical forests. On average, 80% of the nonforest sites were apparent sinks for atmospheric CO(2), with mean net uptake of 700 g CO(2) . m(-2).yr(-1) for intensive grasslands and 933 g CO(2) . m(-2).d(-1) for croplands. However, part of these apparent sinks is accumulated in crops and forage, which are carbon pools that are harvested, transported, and decomposed off site. Therefore, although agricultural fields may be predominantly sinks for atmospheric CO(2), this does not imply that they are necessarily increasing their carbon stock.
ISSN: 1550-7424

hal-01190754
https://hal.archives-ouvertes.fr/hal-01190754
DOI : 10.2111/rem-d-09-00072.1
PRODINRA : 214043

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

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

Éditeur(s) : HAL CCSD Thieme Publishing
Résumé : International audience
The aim of the present study was to compare the effects of prior cycling and a successive run on respiratory muscle performance during a cycle-run succession as performed in the triathlon. We hypothesized that despite the moderate intensity of exercise and the absence of exhaustion, the crouched cycling position would induce a decrease in respiratory muscle performance that would be reversed by the successive vertical run position. Ten male triathletes (22.6 +/- 1.1 yr) performed a four-trial protocol: (1) an incremental cycle test to assess maximal oxygen uptake (VO2max), (2) 20 min of cycling (C), (3) 20 min of running (R), and (4) 20 min of cycling followed by 20 min of running (C-R). Trials 2, 3 and 4 were performed at the same metabolic intensity, i. e., 75 % of VO2max. Respiratory muscle force was assessed by measuring maximal expiratory (P(Emax)) and inspiratory (P(Imax)) pressures from the functional residual capacity (FRC) before and 10 min after C, R, and C-R. Respiratory muscle endurance was assessed one day before and 30 min after C, R, and C-R, by measuring the time limit (T(lim)), which corresponds to the length of time a respiratory load can be sustained before the process of fatigue develops sufficiently to cause task failure. The results showed a similar significant decrease in P(Imax) (132.4 +/- 4.9 versus 125.7 +/- 5.6 cm H2O, p < 0.05) and T(lim) (5.22 +/- 0.28 versus 3.68 +/- 0.32 min, p < 0.05) post-C and post-C-R (133.7 +/- 4.0 versus 126.9 +/- 5.2 cm H2O, and 5.29 +/- 0.18 versus 3.49 +/- 0.41 min, respectively, p < 0.05) compared with the pre-trial values. In contrast, P(Imax) and T(lim) were not significantly decreased post-R (131.8 +/- 6.1 cm H2O versus 129.6 +/- 6.4 cm H2O, and 4.90 +/- 0.69 versus 4.40 +/- 0.56 min, respectively, p > 0.05). We concluded that moderate intensity exercise not performed to exhaustion induced a decrease in respiratory muscle performance. Moreover, the respiratory muscle fatigue induced by prior cycling was maintained, and neither reversed nor worsened, by the successive run.
ISSN: 0172-4622

hal-00720715
https://hal.univ-antilles.fr/hal-00720715

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few 'hyperdominant' species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits. We find that dominance of forest function is even more concentrated in a few species than is dominance of tree abundance, with only ≈1% of Amazon tree species responsible for 50% of carbon storage and productivity. Although those species that contribute most to biomass and productivity are often abundant, species maximum size is also influential, while the identity and ranking of dominant species varies by function and by region.
ISSN: 2041-1723

hal-01204225
https://hal.archives-ouvertes.fr/hal-01204225
DOI : 10.1038/ncomms7857
PRODINRA : 305614
PUBMED : 25919449

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
BACKGROUND & AIMS: Nutrients influence non-alcoholic fatty liver disease. Essential fatty acids deficiency promotes various syndromes, including hepatic steatosis, through increased de novo lipogenesis. The mechanisms underlying such increased lipogenic response remain unidentified. METHODS: We used wild type mice and mice lacking Liver X Receptors to perform a nutrigenomic study that aimed at examining the role of these transcription factors. RESULTS: We showed that, in the absence of Liver X Receptors, essential fatty acids deficiency does not promote steatosis. Consistent with this, Liver X Receptors are required for the elevated expression of genes involved in lipogenesis in response to essential fatty acids deficiency. CONCLUSIONS: This work identifies, for the first time, the central role of Liver X Receptors in steatosis induced by essential fatty acids deficiency.
ISSN: 0168-8278

inserm-00872314
http://www.hal.inserm.fr/inserm-00872314
DOI : 10.1016/j.jhep.2013.01.006
PUBMED : 23333450

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BMC Cancer

hal-00875547
https://hal.archives-ouvertes.fr/hal-00875547

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Neonatal infection constitutes one of Senegal’s most important public health problems, with amortality rate of 41 deaths per 1,000 live births.Methods: Between January 2007 and March 2008, 242 neonates with suspected infection were recruited at threeneonatal intensive care units in three major tertiary care centers in Dakar, the capital of Senegal. Neonatal infections wereconfirmed by positive bacterial blood or cerebrospinal fluid culture. The microbiological pattern of neonatal infectionsand the antibiotic susceptibility of the isolates were characterized. In addition, the genetic basis for antibiotic resistanceand the genetic background of third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae were studied.Results: A bacteriological infection was confirmed in 36.4 % (88/242) of neonates: 22.7 % (30/132) during the early-onsetand 52.7 % (58/110) during the late-onset periods (p > 0.20). Group B streptococci accounted for 6.8 % of the 88 collectedbacterial isolates, while most of them were Enterobacteriaceae (n = 69, 78.4 %). Of these, 55/69 (79.7 %) were 3GC-R. TheblaCTX-M-15 allele, the blaSHV and the blaTEM were highly prevalent (63.5, 65.4 and 53.8 %, respectively), usually associatedwith qnr genes (65.4 %). Clonally related strains of 3GC-R Klebsiella pneumoniae and 3GC-R Enterobacter cloacae, the twomost commonly recovered 3GC-R Enterobacteriaceae (48/55), were detected at the three hospitals, underlining the roleof cross-transmission in their spread. The overall case fatality rate was 18.6 %.Conclusions:Measures should be taken to prevent nosocomial infections and the selection of resistant bacteria
ISSN: 1471-2334

Droits : http://creativecommons.org/licenses/by/
hal-01473613
https://hal.archives-ouvertes.fr/hal-01473613
https://hal.archives-ouvertes.fr/hal-01473613/document
https://hal.archives-ouvertes.fr/hal-01473613/file/High%20third-generation%20cephalosporin%20resistant%20Enterobacteriaceae%20prevalence%20rate%20among%20neonatal%20infections%20in%20Dakar%2C%20Senegal.pdf
DOI : 10.1186/s12879-016-1935-y

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Isotopic fractionation of tritium is a highly relevant issue in radiation protection and requires certain radioecological considerations. Sound evaluation of this factor is indeed necessary to determine whether environmental compartments are enriched/depleted in tritium or if tritium is, on the contrary, isotopically well-distributed in a given system. The ubiquity of tritium and the standard analytical methods used to assay it may induce biases in both the measurement and the signification that is accorded to the so-called fractionation: based on an exhaustive review of the literature, we show how, sometimes large deviations may appear. It is shown that when comparing the non-exchangeable fraction of organically bound tritium (neOBT) to another fraction of tritium (e.g. tritiated water) the preparation of samples and the measurement of neOBT reported frequently led to underestimation of the ratio of tritium to hydrogen (T/H) in the non-exchangeable compartment by a factor of 5 % to 50 %. In the present study, corrections are proposed for most of the biological matrices studied so far. Nevertheless, the values of isotopic fractionation reported in the literature remain difficult to compare with each other, especially since the physical quantities and units often vary between authors. Some improvements are proposed to better define what should encompass the concepts of exchangeable and non-exchangeable fractions.
ISSN: 0160-4120

hal-01117744
https://hal.archives-ouvertes.fr/hal-01117744
https://hal.archives-ouvertes.fr/hal-01117744/document
https://hal.archives-ouvertes.fr/hal-01117744/file/Article%20review%20discrimination%20isotopique-envoy%C3%A9.pdf
DOI : 10.1016/j.envint.2013.12.020

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm) in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households). The GMT for the general population was 47.1 (95% confidence interval (CI): 45.1, 49.2). According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by-sa/
hal-01122215
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122215
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122215/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122215/file/journal.pone.0060127.pdf
PUBMED : 23613718

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Archives of Cardiovascular Diseases Supplements
Strasbourg, France

hal-01118035
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118035
DOI : 10.1016/S1878-6480(14)71283-2

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
Marine protist diversity inventories have largely focused on planktonic environments, while benthic protists have received relatively little attention. We therefore hypothesize that current diversity surveys have only skimmed the surface of protist diversity in marine sediments, which may harbor greater diversity than planktonic environments. We tested this by analyzing sequences of the hypervariable V4 18S rRNA from benthic and planktonic protist communities sampled in European coastal regions. Despite a similar number of OTUs in both realms, richness estimations indicated that we recovered at least 70% of the diversity in planktonic protist communities, but only 33% in benthic communities. There was also little overlap of OTUs between planktonic and benthic communities, as well as between separate benthic communities. We argue that these patterns reflect the heterogeneity and diversity of benthic habitats. A comparison of all OTUs against the Protist Ribosomal Reference database showed that a higher proportion of benthic than planktonic protist diversity is missing from public databases; similar results were obtained by comparing all OTUs against environmental references from NCBI's Short Read Archive. We suggest that the benthic realm may therefore be the world's largest reservoir of marine protist diversity, with most taxa at present undescribed.
ISSN: 0168-6496

hal-01383722
http://hal.upmc.fr/hal-01383722
http://hal.upmc.fr/hal-01383722/document
http://hal.upmc.fr/hal-01383722/file/Forster_2016_Benthic_protists.pdf
DOI : 10.1093/femsec/fiw120

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
Under physiological conditions, the liver sinusoidal endothelial cells (LSECs) mediate hepatic immune tolerance toward self or foreign antigens through constitutive expression of anti-inflammatory mediators. However, upon viral infection or Toll-like receptor 2 (TLR2) activation, LSECs can achieve proinflammatory functions, but their role in hepatic inflammation during acute viral hepatitis is unknown. Using the highly virulent mouse hepatitis virus type 3 (MHV3) and the attenuated variants 51.6-MHV3 and YAC-MHV3, exhibiting lower tropism for LSECs, we investigated in vivo and in vitro the consequence of LSEC infection on their proinflammatory profiles and the aggravation of acute hepatitis process. In vivo infection with virulent MHV3, in comparison to attenuated strains, resulted in fulminant hepatitis associated with higher hepatic viral load, tissue necrosis, and levels of inflammatory mediators and earlier recruitment of inflammatory cells. Such hepatic inflammatory disorders correlated with disturbed production of interleukin-10 (IL-10) and vascular factors by LSECs. We next showed in vitro that infection of LSECs by the virulent MHV3 strain altered their production of anti-inflammatory cytokines and promoted higher release of proinflammatory and procoagulant factors and earlier cell damage than infection by attenuated strains. This higher replication and proinflammatory activation in LSECs by the virulent MHV3 strain was associated with a specific activation of TLR2 signaling by the virus. We provide evidence that TLR2 activation of LSCEs by MHV3 is an aggravating factor of hepatic inflammation and correlates with the severity of hepatitis. Taken together, these results indicate that preservation of the immunotolerant properties of LSECs during acute viral hepatitis is imperative in order to limit hepatic inflammation and damage. IMPORTANCE Viral hepatitis B and C infections are serious health problems affecting over 350 million and 170 million people worldwide, respectively. It has been suggested that a balance between protection and liver damage mediated by the host's immune response during the acute phase of infection would be determinant in hepatitis outcome. Thus, it appears crucial to identify the factors that predispose in exacerbating liver inflammation to limit hepatocyte injury. Liver sinusoidal endothelial cells (LSECs) can express both anti- and proinflammatory functions, but their role in acute viral hepatitis has never been investigated. Using mouse hepatitis virus (MHV) infections as animal models of viral hepatitis, we report for the first time that in vitro and in vivo infection of LSECs by the pathogenic MHV3 serotype leads to a reversion of their intrinsic anti-inflammatory phenotype toward a proinflammatory profile as well to as disorders in vascular factors, correlating with the severity of hepatitis. These results highlight a new virus-promoted mechanism of exacerbation of liver inflammatory response during acute hepatitis.
ISSN: 0022-538X

hal-01390974
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390974
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390974/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390974/file/Mouse%20Hepatitis%20Virus%20Infection_accepted.pdf
DOI : 10.1128/JVI.01069-16

Résumé : Les départements et territoires d'outre mer sont généralement l'objet d'enjeux économiques importants, et de conflits d'activités liés au développement touristique, aquacole, agricole et industriel. Les études font généralement état d'une lente dégradation de l'environnement marin avec diminution des coraux et de la faune associée, au profit d'une augmentation de la couverture algale. On constate parfois un envasement ou un ensablement des sites, la présence dans l'eau de polluants organiques, dont des pesticides, des métaux ainsi que des microorganismes d'origine fécale. En Martinique, ce dernier aspect, lié à l'assainissement des zones rurales, urbaines et touristiques est actuellement considéré comme une préoccupation majeure pour les prochaines années. L'étude réalisée sur le site de la baie de Fort de France en Martinique, en 1990 - 1993, avait pour objectif de définir l'impact des activités sur la qualité bactériologique des eaux de la baie. Ce travail comporte plusieurs aspects : - l'estimation des concentrations en bactéries d'origine fécale des principaux rejets ou rivières situées autour de la baie, - l'étude de la circulation des masses d'eaux dans la baie pour l'établissement d'un modèle hydrodynamique, - l'estimation des temps de mortalité des bactéries d'origine fécale dans les eaux martiniquaises en fonction des conditions locales (ensoleillement, température de l'eau, teneur en matière en suspension ... ).

Droits : 1994 Ifremer
http://archimer.ifremer.fr/doc/00132/24303/22301.pdf
http://archimer.ifremer.fr/doc/00132/24303/

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: The potential interest of antifungal treatment of non-immunocompromized patients with sepsis, extra-digestive Candida colonization and multiple organ failure is unknown. It represents three-quarters of antifungals prescribed in Intensive Care Units. It may allow early treatment of invasive fungal infection in the incubation phase but expose patients to unnecessary antifungal treatments with subsequent cost and fungal selection pressure. As early diagnostic tests for invasive candidiasis are still considered to be insufficient, the potential interest in this strategy needs to be demonstrated. METHODS: This prospective multicenter, double blind, randomized-controlled trial is conducted in 23 French Intensive Care Units. All adult patients, mechanically ventilated for more than four days with sepsis of unknown origin and with at least one extradigestive fungal colonization site and multiple organ failure are eligible for randomization. Patients with proven invasive candidiasis are not included. After a complete mycological screening, patients are allocated to receive micafungin 100 mg intravenously once a day or placebo for 14 days. We plan to enroll 260 patients. The main objective is to demonstrate that micafungin increases survival of patients without invasive candidiasis at day 28 as compared to placebo. Other outcomes include day 28 and 90 survival and organ failure evolution. Additionally, pharmacokinetics of micafungin in enrolled patients will be measured and evolution of fungal biomarkers and susceptibility profiles of infecting fungi will also be followed. DISCUSSION: This study will help to provide guidelines for treating non-immunocompromized patients with fungal colonization multiple organ failure and sepsis of unknown origin.Trial registration: Clinicaltrials.gov number NCT01773876.
ISSN: 1745-6215

inserm-00913515
http://www.hal.inserm.fr/inserm-00913515
http://www.hal.inserm.fr/inserm-00913515/document
http://www.hal.inserm.fr/inserm-00913515/file/1745-6215-14-399.pdf
PUBMED : 24261608

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The Nile delta sedimentation constitutes a continuous high resolution (1.6 mm/year) record of Ethiopian African monsoon regime intensity. Multiproxy analyses performed on core MS27PT recovered in hemipelagic Nile sediment margin (<90 km outward of the Rosetta mouth of the Nile) allow the quantification of the Saharan aeolian dust and the Blue/White Nile River suspended matter frequency fluctuations during the last 21 cal. ka BP. The radiogenic Sr and Nd isotopes, clay mineralogy, bulk elemental composition and palynological analyses reveal large changes in source components, oscillating between a dominant aeolian Saharan contribution during the LGM and the Late Holocene (~4 to 2 cal. ka BP), a dominant Blue/Atbara Nile River contribution during the early Holocene (15 to 8.4 cal. ka BP) and a probable White Nile River contribution during the Middle Holocene (8.4 to 4 cal. ka BP). The following main features are highlighted: 1. The rapid shift from the LGM arid conditions to the African Humid Period (AHP) started at about 15 cal. ka BP. AHP extends until 8.4 cal. ka BP, and we suggest that the Ethiopian African Monsoon maximum between 12 and 8 cal. ka BP is responsible for a larger Blue/Atbara Nile sediment load and freshwater input into the Eastern Mediterranean Sea. 2. The transition between the AHP and the arid Late Holocene is gradual and occurs in two main phases between 8.4 and 6.5 cal. ka BP and 6.5 to 3.2 cal. ka BP. We suggest that the main rain belt shifted southward from 8.4 to ~4 cal. ka BP and was responsible for progressively reduced sediment load and freshwater input into the eastern Mediterranean Sea. 3. The aridification along the Nile catchments occurred from ~4 to 2 cal. ka BP. A dry period, which culminates at 3.2 cal. ka BP, and seems to coincide with a re-establishment of increased oceanic primary productivity in the western Mediterranean Sea. We postulate that the decrease in thermo-haline water Mediterranean circulation could be part of a response to huge volumes of fresh-water delivered principally by the Nile River from 12 to 8.4 cal. ka BP in the eastern Mediterranean. We propose that the large hydrological change in Ethiopian latitude could be a trigger for the 8.2 ka cooling event recorded in high latitude. Revel R., Colin C., Bernasconi S., Combourieu-Nebout N., Ducassou E., Grousset F.E., Rolland Y., Migeon S., Brunet P., Zhaa Y., Bosch D., Mascle J.,. "21,000 years of Ethiopian African moonsoon variability recorded in sediments of the western Nile deep sea fan", Regional Environmental Change,
ISSN: 1436-3798

hal-00836300
https://hal.archives-ouvertes.fr/hal-00836300

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Retreatment with pegylated interferon (peg-IFN) and ribavirin (RBV) results in poor sustained virological response (SVR) rates in human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients. There are limited data regarding the use of telaprevir plus peg-IFN/RBV in this population. HIV type 1-infected patients who previously failed ≥12 weeks of peg-IFN/RBV for HCV genotype 1 coinfection were enrolled in a single-arm, phase 2 trial. Patients with cirrhosis and previous null response were excluded. Authorized antiretrovirals were tenofovir, emtricitabine, efavirenz, atazanavir, and raltegravir. All patients received peg-IFN alfa-2a (180 µg/week) plus RBV (1000-1200 mg/day) for 4 weeks, followed by telaprevir (750 mg or 1125 mg every 8 hours with efavirenz) plus peg-IFN/RBV for 12 weeks and peg-IFN/RBV for 32-56 weeks according to virological response at week 8. The primary endpoint was the SVR rate at 24 weeks after the end of treatment (SVR24). Sixty-nine patients started treatment; SVR24 was achieved in 55 (80% [95% confidence interval, 68%-88%). SVR24 was not influenced by baseline fibrosis stage, IL28B genotype, antiretroviral regimen, HCV subtype, CD4 cell count, previous response to HCV treatment, HCV RNA level, or HCV RNA decline at week 4. HCV treatment was discontinued for adverse events (AEs) in 20% of patients, including cutaneous (4%), psychiatric (4%), hematological (6%), and other AEs (6%). Peg-IFN or RBV dose reduction was required in 23% and 43% of patients, respectively. Seventy percent of patients required erythropoietin, blood transfusions, or RBV dose reduction for anemia. Two patients died during the study. No HIV breakthrough was observed. Despite a high discontinuation rate related to toxicity, a substantial proportion of treatment-experienced HIV-coinfected patients achieved SVR24 with a telaprevir-based regimen. Clinical Trials Registration. NCT01332955.
ISSN: 1058-4838

hal-01118447
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118447
PUBMED : 25139963
DOI : 10.1093/cid/ciu659

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Objectifs. - Évaluer les effets du triathlon classique (1,5 km natation, 40 km cyclisme, 10 km course à pied) sur la capacité de diffusion pulmonaire (DLCO) 24 heures après la compétition. Méthodes et résultats. - Dix triathlètes masculins (21,5 ± 2,8 ans) ont effectué une spirométrie et une mesure de la capacité de diffusion pulmonaire avant la compétition (pré-T) et 24 heures après l'épreuve (post-T). Les résultats montrent une diminution significative du volume expiratoire maximal en 1 s (5,17 ± 0,4 L.s-1 contre 4,09 ± 0,6 L.s-1) et du débit expiratoire maximal 25-75 % de la capacité vitale (6,98 ± 0,2 L.s-1 contre 4,90 ± 0,2 L.s-1). En revanche, les résultats ne montrent pas de différence significative entre les DLCO pré-T et post-T (38,1 ± 3,3 mL.min-1.mmHg-1 contre 37,1 ± 3,7 mL.min-1.mmHg-1) ni les ratios DLCO/VA (5,59 ± 0,5 mL.min-1.mmHg-1.A-1 contre 5,55 ± 0,7 ml.min-1.mmHg-1.A-1). Conclusion. - La DLCO est normale chez les triathlètes 24 heures après une compétition classique. Ceci peut traduire l'absence de lésions alvéolocapillaires pendant le triathlon. La baisse de la DLCO rapportée deux heures après un exercice dans la littérature peut s'expliquer par la baisse du volume sanguin pulmonaire qui apparaît comme un phénomène transitoire. Cependant, la baisse des débits pulmonaires observée 24 heures après le triathlon suggère la persistance chez les triathlètes d'un syndrome obstructif bronchique.
ISSN: 0765-1597

hal-00720522
https://hal.univ-antilles.fr/hal-00720522
https://hal.univ-antilles.fr/hal-00720522/document
https://hal.univ-antilles.fr/hal-00720522/file/Article_3_.pdf

Éditeur(s) : HAL CCSD ACSM
Résumé : International audience
The aim of this study was to examine the effects of the cycle-run and run-cycle successions of the triathlon and duathlon, respectively, on respiratory muscle strength and endurance. Methods: Respiratory muscle strength was assessed by measuring maximal inspiratory (P1max) and expiratory {PEmax) pressures. Respiratory muscle endurance was assessed by measuring the time limit (Tlim). Twelve triathleles participated in a three-trial protocol. The first trial consisted of an incremental cycle test to assess the maximal oxygen uptake (VO2max) of triathletes. Trial 2 consisted of 20 min of cycling followed by 20 min of running (C-R), and trial 3 consisted of 20 min of running followed by 20 min of cycling (R-C). Trials 2 and 3 were performed at the same metabolic intensity (% VO2max). P1max and P1max were measured before and 10 min after C-R and R-C, and I min after the post-C-R and post-R-C Tlim measurements (P1max l'). Tlim was measured I d before and 30 min after C-R and R-C. Results: The results showed a significant decrease in P1max after C-R (126.7 ± 4.3 cmH2O, P < 0.05) and R-C (123.7 ± 4.9 cmH2O, P < 0.05) compared with the baseline values (130 ± 3.8 and 129.6 ± 4.3 cmH2O, respectively). P1max 1' showed a significantly greater decrease after R-C versus C-R(111.2 ± 5.5 cmH2O vs 121.2 ± 3.9 cmH2O,respectively, P < 0.001). Tlim after C-R (3.3 ± 0.3 min) decreased significantly compared with baseline values (4.19 ± 0.3min and 4.02 ± 0.3 min, respectively). However, the Tlim decrease after R-C was significantly greater than after C-R (P < 0.001). Conclusion: We concluded that respiratory muscle strength and endurance were less decreased after the cycle-run succession and that cycling induced a greater decrease in respiratory muscle endurance than running.
Medicine & Science in Sports & exercise

hal-00720796
https://hal.univ-antilles.fr/hal-00720796

Éditeur(s) : HAL CCSD
Résumé : International audience
The corrosion rates in the presence of some indole derivates, namely, 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane), as inhibitors of C38 steel corrosion inhibitor in 1 M HCl solution, were measured by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, in the range of temperatures from 25 to 55∘C. Results obtained revealed that the organic compounds investigated have inhibiting properties for all temperatures. The inhibition was assumed to occur via adsorption of the indole molecules on the metal surface. Adsorption of indole derivates was found to follow the Langmuir isotherm. The apparent activation energies, enthalpies, and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined by potentiodynamic polarization and electrochemical impedance. The fundamental thermodynamic functions were used to collect important information about indole inhibitory behaviour.
international Journal of Corrosion

hal-01683120
https://hal.univ-antilles.fr/hal-01683120
DOI : 10.1155/2013/139798

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The Hedgehog (Hh) family of secreted proteins act as morphogens to control embryonic patterning and development in a variety of organ systems. Post-translational covalent attachment of cholesterol and palmitate to Hh proteins are critical for multimerization and long range signaling potency. However, the biological impact of lipid modifications on Hh ligand distribution and signal reception in humans remains unclear. In the present study, we report a unique case of autosomal recessive syndromic 46,XY Disorder of Sex Development (DSD) with testicular dysgenesis and chondrodysplasia resulting from a homozygous G287V missense mutation in the hedgehog acyl-transferase (HHAT) gene. This mutation occurred in the conserved membrane bound O-acyltransferase (MBOAT) domain and experimentally disrupted the ability of HHAT to palmitoylate Hh proteins such as DHH and SHH. Consistent with the patient phenotype, HHAT was found to be expressed in the somatic cells of both XX and XY gonads at the time of sex determination, and Hhat loss of function in mice recapitulates most of the testicular, skeletal, neuronal and growth defects observed in humans. In the developing testis, HHAT is not required for Sertoli cell commitment but plays a role in proper testis cord formation and the differentiation of fetal Leydig cells. Altogether, these results shed new light on the mechanisms of action of Hh proteins. Furthermore, they provide the first clinical evidence of the essential role played by lipid modification of Hh proteins in human testicular organogenesis and embryonic development.
ISSN: 1553-7390

hal-01063929
https://hal.archives-ouvertes.fr/hal-01063929
DOI : 10.1371/journal.pgen.1004340
PUBMED : 24784881