Etude et modélisation des transferts d'eau et de sel en milieu deltaïque agricole (Camargue-France)

L objectif premier de ce travail est l étude puis la modélisation numérique 3D du fonctionnement hydrogéologique et salin actuel d une partie de l aquifère superficiel de la Moyenne Camargue afin de l utiliser, dans un second temps, pour la prévision qualitative des modifications induites par le changement climatique. La caractérisation de l aquifère a été mené selon deux approches: une étude structurale, en utilisant des sondages à la tarière et différentes techniques géophysiques (ERT, ES et cartographie EM), et une étude hydrogéologique, intégrée par plusieurs campagnes de pompages, suivi piézométrique et des prélèvements de l eau souterraine. Cette méthodologie a servi pour caractériser la géométrie de l aquifère superficiel ainsi que son fonctionnement actuel et les processus qui l affectent. Divers phénomènes environnementaux ont été identifiés, tels que: un lessivage du sol grâce à l action de l irrigation, un endoréisme observé dans les zones basses produit par l effet de l évaporation, et la reproduction des fluctuations de l étang de Vaccarès dans la piézométrie, jusqu au moins 30m de la rive. Le modèle numérique construit à partir des observations du terrain reproduit les principaux processus observés. Il met en évidence un possible flux sortant vers le Vaccarès et le rôle important du marais dans l hydrodynamique et le comportement hydrosalin du système. Les résultats du modèle face aux différents scénarios de prédiction montrent une intrusion d eau du Vaccarès et, donc, une salinisation du système induit par la remontée du niveau marin, ainsi que la présence de l irrigation et le marais comme facteurs essentiels dans la neutralisation de cette salinisation.The main objective in this investigation is to construct a representative 3D numerical groundwater flow model of a local superficial aquifer in the Medium Camargue plain to simulate the actual hydrogeological and salt behavior. The 3D model will be used, in a second time, to simulate modifications of the system behavior provide by climate changes. The characterization of the aquifer was carried out by two approaches: a structural survey, using auger drilling technique and some geophysics techniques (EM mapping ERT, ES and), and a hydrogeological survey composed by several pumping tests, piezometric monitoring and groundwater samples. The methodological approach used allowed characterizing the geometry, behavior of the system and the process governing performance of the superficial aquifer. Several environmental phenomena were been identified, such as: a soil s leaching; an endorheic phenomenon at the lower elevation areas; and the reproduction of the Vaccares pond s fluctuations at the water table, until 30 m from shore. The numerical model, which has been constructed through field observations, reproduces principal process of the aquifer. This model highlights a possible outflow from the aquifer to the Vaccares pond and the important role of marsh in the hydrodynamic and hydrosaline behavior of the system. The results of the prediction scenarios tested with the numerical model highlights a possible intrusion from Vaccares water and, therefore, a salinization of the system produced by increase of sea level rise. The important presence of the irrigation and the marsh to neutralize a future salinization has been exposed.AVIGNON-Bib. numérique (840079901) / SudocSudocFranceF

Geochemistry of Clay Dunes and Associated Pan in the Senegal Delta, Mauritania

L Since the construction of the anti-salting Diama dam, a resumption of aeolian deflation has been observed in the Senega

Algebraic and Topological Invariants of Curves and Surfaces with Quotient Singularities

Le but principal de cette thèse de doctorat est l'étude de l'anneau de cohomologie du complément d'une courbe algébrique réduite dans le plan projectif pondéré complexe dont les composantes irréductibles sont des courbes rationnelles (avec ou sans points singuliers). En particulier, des représentants holomorphes (rationnels) sont obtenus pour les classes de cohomologie. Pour atteindre notre objectif, il est nécessaire de développer une théorie algébrique des courbes sur des surfaces avec des singularités quotient et d'étudier des techniques pour calculer certains invariants particulièrement utiles à travers des Q-résolutions plongées.The main goal of this PhD thesis is the study of the cohomology ring of the complement of a reduced algebraic curve in the complex weighted projective plane whose irreducible components are all rational (possibly singular) curves. In particular, holomorphic (rational) representatives are found for the cohomology classes. In order to achieve our purpose one needs to develop an algebraic theory of curves on surfaces with quotient singularities and study techniques to compute some particularly useful invariants by means of embedded Q-resolutions.PAU-BU Sciences (644452103) / SudocSudocFranceF

17‐Beta Hydroxysteroid Dehydrogenase 13 Is a Hepatic Retinol Dehydrogenase Associated With Histological Features of Nonalcoholic Fatty Liver Disease

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148371/1/hep30350.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148371/2/hep30350_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148371/3/hep30350-sup-0001-Supinfo.pd

Detection of Plant DNA in the Bronchoalveolar Lavage of Patients with Ventilator-Associated Pneumonia

BACKGROUND: Hospital-acquired infections such as nosocomial pneumonia are a serious cause of mortality for hospitalized patients, especially for those admitted to intensive care units (ICUs). Despite the number of the studies reported to date, the causative agents of pneumonia are not completely known. Herein, we found by molecular technique that vegetable and tobacco DNA may be detected in the bronchoalveolar lavage from patients with ventilator-associated pneumonia (VAP). METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we studied bronchoalveolar lavage (BAL) from patients admitted to ICUs with ventilator-associated pneumonia. BAL fluids were assessed with molecular tests, culture and blood culture. We successfully identified plant DNA in six patients out of 106 (6%) with ventilator-associated pneumonia. Inhalation was confirmed in four cases and suspected in the other two cases. Inhalation was significantly frequent in patients with plant DNA (four out of six patients) than those without plant DNA (three out of 100 patients) (P<0.001). Nicotiana tabacum chloroplast DNA was identified in three patients who were smokers (cases 2, 3 and 6). Cucurbita pepo, Morus bombycis and Triticum aestivum DNA were identified in cases 1, 4 and 5 respectively. Twenty-three different bacterial species, two viruses and five fungal species were identified from among these six patients by using molecular and culture techniques. Several of the pathogenic microorganisms identified are reported to be food-borne or tobacco plant-associated pathogens. CONCLUSIONS/SIGNIFICANCE: Our study shows that plants DNA may be identified in the BAL fluid of pneumonia patients, especially when exploring aspiration pneumonia, but the significance of the presence of plant DNA and its role in the pathogenesis of pneumonia is unknown and remains to be investigated. However, the identification of these plants may be a potential marker of aspiration in patients with pneumonia

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead