15 research outputs found

    Measurements of nitric oxide and ammonia soil fluxes from a wet savanna ecosystem site in West Africa during the DACCIWA field campaign

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    Biogenic fluxes from soil at a local and regional scale are crucial to study air pollution and climate. Here we present field measurements of soil fluxes of nitric oxide (NO) and ammonia (NH3) observed over four different land cover types, i.e. bare soil, grassland, maize field, and forest, at an inland rural site in Benin, West Africa, during the DACCIWA field campaign in June and July 2016. At the regional scale, urbanization and a massive growth in population in West Africa have been causing a strong increase in anthropogenic emissions. Anthropogenic pollutants are transported inland and northward from the megacities located on the coast, where the reaction with biogenic emissions may lead to enhanced ozone production outside urban areas, as well as secondary organic aerosol formation, with detrimental effects on humans, animals, natural vegetation, and crops. We observe NO fluxes up to 48.05 ngNm 2 s 1. NO fluxes averaged over all land cover types are 4:79 5:59 ngNm 2 s 1, and maximum soil emissions of NO are recorded over bare soil. NH3 is dominated by deposition for all land cover types. NH3 fluxes range between 6:59 and 4.96 ngNm 2 s 1. NH3 fluxes averaged over all land cover types are 0:911:27 ngNm 2 s 1, and maximum NH3 deposition is measured over bare soil. The observations show high spatial variability even for the same soil type, same day, and same meteorological conditions. We compare point daytime average measurements of NO emissions recorded during the field campaign with those simulated by GEOS-Chem (Goddard Earth Observing System Chemistry Model) for the same site and find good agreement. In an attempt to quantify NO emissions at the regional and national scale, we also provide a tentative estimate of total NO emissions for the entire country of Benin for the month of July using two distinct methods: upscaling point measurements and using the GEOS-Chem model. The two methods give similar results: 1:170:6 and 1.44 GgN month 1, respectively. Total NH3 deposition estimated by upscaling point measurements for the month of July is 0.21 GgN month1

    Approches génériques pour calculer le plan de production des procédés d'un smart grid

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    International audienceLe souhait d'augmenter la part des Ă©nergies renouvelables dans le mix Ă©nergĂ©tique entraine une augmentation des parts des Ă©nergies non pilotables. Une façon d'intĂ©grer ces Ă©nergies dans le rĂ©seau Ă©lectrique actuel est de moduler la courbe de charge en utilisant des procĂ©dĂ©s regroupĂ©s au sein d'un smart grid. Afin de piloter ce dernier comme une centrale classique il est nĂ©cessaire de dĂ©terminer son plan de production, ce qui implique de calculer trĂšs rapidement le plan de production de chacun de ses procĂ©dĂ©s. L'objectif principal de cette Ă©tude est donc de calculer le plan de production optimal de n'importe quel type de procĂ©dĂ© en moins d'une minute, de façon Ă  maximiser son gain en fonction d'un signal de prix reçu. Les procĂ©dĂ©s peuvent ĂȘtre classĂ©s en six groupes : les procĂ©dĂ©s de production pilotable, de consommation pilotable, de dĂ©placement de production non pilotable, de consommation non pilotable, de stockage, et de dĂ©placement de consommation pilotable. Suivant leur nature, ces procĂ©dĂ©s ont des caractĂ©ristiques diffĂ©rentes et peuvent ĂȘtre soumis Ă  diverses contraintes.  Nous proposons un modĂšle gĂ©nĂ©rique de programmation par contraintes (PPC) et un modĂšle gĂ©nĂ©rique de programmation linĂ©aire en nombres entiers (PLNE). Les rĂ©sultats montrent que les premiĂšres solutions trouvĂ©es par le solveur de PLNE sont trĂšs Ă©loignĂ©es de l'optimum, alors que la mĂ©thode de PPC fournit trĂšs rapidement de bonnes solutions. En utilisant la PPC afin de trouver une solution initiale pour le solveur de PLNE, les rĂ©sultats sont nettement amĂ©liorĂ©s : le gap moyen pour la combinaison des deux mĂ©thodes est de 1,79 % contre 5,73 % pour la PPC et 6,03 % pour la PLNE, et 52 % des problĂšmes sont rĂ©solus en moins d'une minute.</p

    A meteorological dataset of the West African monsoon during the 2016 DACCIWA campaign

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    International audienceAbstractAs part of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, extensive in-situ measurements of the southern West African atmospheric boundary layer (ABL) have been performed at three supersites Kumasi (Ghana), SavĂš (Benin) and Ile-Ife (Nigeria) during the 2016 monsoon period (June and July). The measurements were designed to provide data for advancing our understanding of the relevant processes governing the formation, persistence and dissolution of nocturnal low-level stratus clouds and their influence on the daytime ABL in southern West Africa. An extensive low-level cloud deck often forms during the night and persists long into the following day strongly influencing the ABL diurnal cycle. Although the clouds are of a high significance for the regional climate, the dearth of observations in this region has hindered process understanding. Here, an overview of the measurements ranging from near-surface observations, cloud characteristics, aerosol and precipitation to the dynamics and thermodynamics in the ABL and above, and data processing is given. So-far achieved scientific findings, based on the dataset analyses, are briefly overviewed.</jats:p

    High Risk of Anal and Rectal Cancer in Patients With Anal and/or Perianal Crohn’s Disease

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    International audienceBackground & AimsLittle is known about the magnitude of the risk of anal and rectal cancer in patients with anal and/or perineal Crohn’s disease. We aimed to assess the risk of anal and rectal cancer in patients with Crohn’s perianal disease followed up in the Cancers Et Surrisque AssociĂ© aux Maladies Inflammatoires Intestinales En France (CESAME) cohort.MethodsWe collected data from 19,486 patients with inflammatory bowel disease (IBD) enrolled in the observational CESAME study in France, from May 2004 through June 2005; 14.9% of participants had past or current anal and/or perianal Crohn’s disease. Subjects were followed up for a median time of 35 months (interquartile range, 29–40 mo). To identify risk factors for anal cancer in the total CESAME population, we performed a case-control study in which participants were matched for age and sex.ResultsAmong the total IBD population, 8 patients developed anal cancer and 14 patients developed rectal cancer. In the subgroup of 2911 patients with past or current anal and/or perianal Crohn’s lesions at cohort entry, 2 developed anal squamous-cell carcinoma, 3 developed perianal fistula–related adenocarcinoma, and 6 developed rectal cancer. The corresponding incidence rates were 0.26 per 1000 patient-years for anal squamous-cell carcinoma, 0.38 per 1000 patient-years for perianal fistula–related adenocarcinoma, and 0.77 per 1000 patient-years for rectal cancer. Among the 16,575 patients with ulcerative colitis or Crohn’s disease without anal or perianal lesions, the incidence rate of anal cancer was 0.08 per 1000 patient-years and of rectal cancer was 0.21 per 1000 patient-years. Among factors tested by univariate conditional regression (IBD subtype, disease duration, exposure to immune-suppressive therapy, presence of past or current anal and/or perianal lesions), the presence of past or current anal and/or perianal lesions at cohort entry was the only factor significantly associated with development of anal cancer (odds ratio, 11.2; 95% CI, 1.18-551.51; P = .03).ConclusionsIn an analysis of data from the CESAME cohort in France, patients with anal and/or perianal Crohn’s disease have a high risk of anal cancer, including perianal fistula–related cancer, and a high risk of rectal cancer

    Persistent headaches one year after bacterial meningitis: prevalence, determinants and impact on quality of life

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    International audienceBackground: Little is known on headaches long-term persistence after bacterial meningitis and on their impact on patients' quality of life.Methods: In an ancillary study of the French national prospective cohort of community-acquired bacterial meningitis in adults (COMBAT) conducted between February 2013 and July 2015, we collected self-reported headaches before, at onset, and 12 months (M12) after meningitis. Determinants of persistent headache (PH) at M12, their association with M12 quality of life (SF 12), depression (Center for Epidemiologic Studies Depression Scale) and neuro-functional disability were analysed.Results: Among the 277 alive patients at M12 87/274 (31.8%), 213/271 (78.6%) and 86/277 (31.0%) reported headaches before, at the onset, and at M12, respectively. In multivariate analysis, female sex (OR: 2.75 [1.54-4.90]; p < 0.001), pre-existing headaches before meningitis (OR: 2.38 [1.32-4.30]; p < 0.01), higher neutrophilic polynuclei percentage in the CSF of the initial lumbar puncture (OR: 1.02 [1.00-1.04]; p < 0.05), and brain abscess during the initial hospitalisation (OR: 8.32 [1.97-35.16]; p < 0.01) were associated with M12 persistent headaches. Neither the responsible microorganism, nor the corticoids use were associated with M12 persistent headaches. M12 neuro-functional disability (altered Glasgow Outcome Scale; p < 0.01), M12 physical handicap (altered modified Rankin score; p < 0.001), M12 depressive symptoms (p < 0.0001), and M12 altered physical (p < 0.05) and mental (p < 0.0001) qualities of life were associated with M12 headaches.Conclusion: Persistent headaches are frequent one year after meningitis and are associated with quality of life alteration

    One-Year Sequelae and Quality of Life in Adults with Meningococcal Meningitis: Lessons from the COMBAT Multicentre Prospective Study

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    Trial registration: ClinicalTrial.Gov identification number NCT01730690.International audienceIntroduction: COMBAT is a prospective, multicentre cohort study that enrolled consecutive adults with community-acquired bacterial meningitis (CABM) in 69 participating centres in France between February 2013 and July 2015 and followed them for 1 year.Methods: Patients aged at least 18 years old, hospitalised with CABM were followed during their hospitalisation and then contacted by phone 12 months after enrolment. Here we present the prevalence of sequelae at 12 months in a subgroup of patients with meningococcal meningitis.Results: Five of the 111 patients with meningococcal meningitis died during initial hospitalisation and two died between discharge and 12 months, leaving 104 patients alive 1 year after enrolment, 71 of whom provided 12-month follow-up data. The median age was 30.0 years and 54.1% of the patients had no identified risk factor for meningitis. More than 30% reported persistent headache, more than 40% were not satisfied with their sleep and 10% had concentration difficulties. Hearing loss was present in about 15% of the patients and more than 30% had depressive symptoms. About 13% of the patients with a previous professional activity had not resumed work. On the SF-12 Health Survey, almost 50% and 30% had physical component or mental component scores lower than the 25th percentile of the score distribution in the French general population. There was a non-significant improvement in the patients' disability scores from hospital discharge to 12 months (p = 0.16), but about 10% of the patients had residual disability.Conclusions: Although most patients in our cohort survive meningococcal meningitis, the long-term burden is substantial and therefore it is important to ensure a prolonged follow-up of survivors and to promote preventive strategies, including vaccination

    Relationship between serotypes, disease characteristics and 30-day mortality in adults with invasive pneumococcal disease

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    Reaching the Second and Third Joint United Nations Programme on Human Immunodeficiency Virus (HIV)/AIDS 90-90-90 Targets Is Accompanied by a Dramatic Reduction in Primary HIV Infection and in Recent HIV Infections in a Large French Nationwide HIV Cohort

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    International audienceAbstract Background In late 2013, France was one of the first countries to recommend initiation of combination antiretroviral therapy (cART) irrespective of CD4 cell count. Methods To assess the impact of achieving the second and third Joint United Nations Programme on HIV/AIDS 90-90-90 targets (ie, 90% of diagnosed people on sustained cART, and, of those, 90% virologically controlled) on human immunodeficiency virus (HIV) incidence, we conducted a longitudinal study to describe the epidemiology of primary HIV infection (PHI) and/or recent HIV infection (patients with CD4 cell count ≄500/mm3 at HIV diagnosis; (PRHI) between 2007 and 2017 in a large French multicenter cohort. To identify changes in trends in PHI and PRHI, we used single breakpoint linear segmented regression analysis. Results During the study period, 61 822 patients were followed in the Dat’AIDS cohort; 2027 (10.0%) had PHI and 7314 (36.1%) had PRHI. The second and third targets were reached in 2014 and 2013, respectively. The median delay between HIV diagnosis and cART initiation decreased from 9.07 (interquartile range [IQR], 1.39–33.47) months in 2007 to 0.77 (IQR, 0.37–1.60) months in 2017. A decrease in PHI (−35.1%) and PRHI (−25.4%) was observed starting in 2013. The breakpoints for PHI and PRHI were 2012.6 (95% confidence interval [CI], 2010.8–2014.4) and 2013.1 (95% CI, 2011.3–2014.8), respectively. Conclusions Our findings show that the achievements of 2 public health targets in France and the early initiation of cART were accompanied by a reduction of about one-third in PHI and PRHI between 2013 and 2017. Clinical Trials Registration NCT02898987
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