L'aide à l'accès à l'information géographique (un environnement de conception coopérative d'utilisations de données géographiques)

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Mathématiques rech (751052111) / SudocSudocFranceF

APPORTS D'UNE CONCEPTION ORIENTEE OBJET A LA RESOLUTION NUMERIQUE DES EQUATIONS DE MAXWELL DANS LE CADRE D'UNE METHODOLOGIE DE FACTORISATION

PARIS-BIUSJ-Mathématiques rech (751052111) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF

Enrichissement d un ensemble logiciel d exploitation automatique des canaux (extension des bibliothèques de commandes et conception d outils de diagnostics et de reconstitution de mesures)

Le transport de l eau dans les canaux à surface libre pose problème dès lors que la préservation de la ressource devient un enjeu majeur. Le Canal de Provence a mis en place une commande centralisée qui permet de gérer le canal de façon coordonnée et optimisée. Pour cela l exploitation doit s appuyer sur un réseau de mesures et une suite logicielle adaptée. La première partie de ce travail consiste en l'étude du principe physique de la dynamique contrôlée. La régulation nécessite l estimation des volumes en transit et des retards de propagation. La modélisation a été analysée afin d en connaître les incertitudes et les limites. La seconde partie consiste en une nouvelle formalisation informatique et en la mise en place opérationnelle de nouvelles méthodes de contrôle du canal. Enfin, la troisième partie a mené à la conception d outils de reconstruction de mesures basés principalement sur le filtre de Kalman. Les mesures sont en effet la base du processus de contrôle. Ce travail a mené à la mise en place d extensions logicielles qui sont aujourd hui en fonctionnement sur le canal.PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Mathématiques rech (751052111) / SudocFONTAINEBLEAU-MINES ParisTech (771862302) / SudocSudocFranceF

Bases de données d'images- Calculateurs parallèles

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Mathématiques rech (751052111) / SudocSudocFranceF

Action of bacteriolytic enzymes, other than lysozyme, on bacterial cell wall pepticoglycan

peer reviewedLa structure réticulaire proposée pour le peptidoglycane des parois cellulaires bactériennes permet de comprendre les propriétés apparemment contradictoires de résistance mécanique et d'extensibilité qui caractérisent cette structure anatomique, unique dans le monde vivant, destinée à protéger contre l'éclatement osmotique des êtres unicellulaires dont le temps de génération est parfois de quelques dizaines de minutes. Ces études de structure basées sur des dégradations enzymatiques contrôlées, jointes aux recherches sur la biosynthèse du peptidoglycane, ont également permis d'interpréter le mécanisme d'action d'un certain nombre d'antibiotiques. La pénicilline, en particulier, a pour effet d'induire chez S. aureus la formation d'un peptidoglycane fragile dont beaucoup de chaînes polyglycine ont leurs extrémités NH² libres [31, 37]. Chez ces cellules intoxiquées, la réaction de transpeptidisation qui assure normalement la fermeture des ponts, est inhibée. Il est frappant de constater que l'inhibition de la biosynthèse de la liaison D-alanylglycine par la pénicilline provoque la lyse d'une culture de staphylocoques en voie de multiplication et que l'ouverture de cette même liaison par la SA. endopeptidase a pour effet de dissoudre les parois staphylococciques isolées

Structural variations in bacterial cell wall peptidoglycans studied with Streptomyces F1 endo-N-acetylmuramidase

An improved procedure for the purification of the Streptomyces FI [beta]-l,4 endo-N-acetylmuramidase is described. FI enzymes digests cell walls from bacteria of the most important grampositive genera. Its mechanism of action upon cell walls of Staphylococcus aureus, Micrococcus roseus, and Micrococcus lysodeikticus has been studied. To all appearances, the affinity of the F1 enzyme for the glycosidic linkages of N-acetylmuramic add in the polysaccharide chains is greatly enhanced by the peptide substitution of these residues. From an integration of the properties of the FI enzyme digests of various cell walls, it appears that tight network peptidoglycans, typified by a high degree of cross-linkings of the polysaccharide chains through peptide unites, as they occur in cell wals of S. aureus and M. roseus, are not encountered in many cell walls from gram-positive bacteria

Effect of Tocilizumab vs Usual Care in Adults Hospitalized With COVID-19 and Moderate or Severe Pneumonia

International audienceImportance Severe pneumonia with hyperinflammation and elevated interleukin-6 is a common presentation of coronavirus disease 2019 (COVID-19).Objective To determine whether tocilizumab (TCZ) improves outcomes of patients hospitalized with moderate-to-severe COVID-19 pneumonia.Design, Setting, and Particpants This cohort-embedded, investigator-initiated, multicenter, open-label, bayesian randomized clinical trial investigating patients with COVID-19 and moderate or severe pneumonia requiring at least 3 L/min of oxygen but without ventilation or admission to the intensive care unit was conducted between March 31, 2020, to April 18, 2020, with follow-up through 28 days. Patients were recruited from 9 university hospitals in France. Analyses were performed on an intention-to-treat basis with no correction for multiplicity for secondary outcomes.Interventions Patients were randomly assigned to receive TCZ, 8 mg/kg, intravenously plus usual care on day 1 and on day 3 if clinically indicated (TCZ group) or to receive usual care alone (UC group). Usual care included antibiotic agents, antiviral agents, corticosteroids, vasopressor support, and anticoagulants.Main Outcomes and Measures Primary outcomes were scores higher than 5 on the World Health Organization 10-point Clinical Progression Scale (WHO-CPS) on day 4 and survival without need of ventilation (including noninvasive ventilation) at day 14. Secondary outcomes were clinical status assessed with the WHO-CPS scores at day 7 and day 14, overall survival, time to discharge, time to oxygen supply independency, biological factors such as C-reactive protein level, and adverse events.Results Of 131 patients, 64 patients were randomly assigned to the TCZ group and 67 to UC group; 1 patient in the TCZ group withdrew consent and was not included in the analysis. Of the 130 patients, 42 were women (32%), and median (interquartile range) age was 64 (57.1-74.3) years. In the TCZ group, 12 patients had a WHO-CPS score greater than 5 at day 4 vs 19 in the UC group (median posterior absolute risk difference [ARD] −9.0%; 90% credible interval [CrI], −21.0 to 3.1), with a posterior probability of negative ARD of 89.0% not achieving the 95% predefined efficacy threshold. At day 14, 12% (95% CI −28% to 4%) fewer patients needed noninvasive ventilation (NIV) or mechanical ventilation (MV) or died in the TCZ group than in the UC group (24% vs 36%, median posterior hazard ratio [HR] 0.58; 90% CrI, 0.33-1.00), with a posterior probability of HR less than 1 of 95.0%, achieving the predefined efficacy threshold. The HR for MV or death was 0.58 (90% CrI, 0.30 to 1.09). At day 28, 7 patients had died in the TCZ group and 8 in the UC group (adjusted HR, 0.92; 95% CI 0.33-2.53). Serious adverse events occurred in 20 (32%) patients in the TCZ group and 29 (43%) in the UC group (P = .21).Conclusions and Relevance In this randomized clinical trial of patients with COVID-19 and pneumonia requiring oxygen support but not admitted to the intensive care unit, TCZ did not reduce WHO-CPS scores lower than 5 at day 4 but might have reduced the risk of NIV, MV, or death by day 14. No difference on day 28 mortality was found. Further studies are necessary for confirming these preliminary results.Trial Registration ClinicalTrials.gov Identifier: NCT0433180

Sarilumab in adults hospitalised with moderate-to-severe COVID-19 pneumonia (CORIMUNO-SARI-1): An open-label randomised controlled trial

International audienc