26 research outputs found

    Transparent boundary conditions for locally perturbed infinite hexagonal periodic media.

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    International audienceIn this paper, we propose a strategy to determine the Dirichlet-to-Neumann (DtN) operator for infinite, lossy and locally perturbed hexagonal periodic media. We obtain a factorization of this operator involving two non local operators. The first one is a DtN type operator and corresponds to a half-space problem. The second one is a Dirichlet-to-Dirichlet (DtD) type operator related to the symmetry properties of the problem. The half-space DtN operator is characterized via Floquet-Bloch transform, a family of elementary strip problems and a family of stationary Riccati equations. The DtD operator is the solution of an affine operator valued equation which can be reformulated as a non standard integral equation

    The diagnosis of rupture of fetal membranes (ROM): a meta-analysis

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    Aim: The aim of this study was to compare the performance of tests based on the detection of insulin-like growth factor binding protein 1 (IGFBP-1) and placental α-microglobulin-1 (PAMG-1) in diagnosing rupture of fetal membranes (ROM) across different patient populations. Methods: A meta-analysis was conducted on prospective observational or cohort studies investigating ROM tests based on the detection of IGFBP-1 and PAMG-1 meeting the following criteria: (1) performance metrics calculated by comparing results to an adequate reference method; (2) sensitivity thresholds of the investigated tests matching those of the currently available tests; (3) study population, as a minimum, included patients between 25 and 37 weeks of gestation. Sensitivities, specificities, and diagnostic odds ratios were calculated. Results: Across all patient populations, the analyzed performance measures of the PAMG-1 test were significantly superior compared with those of the IGFBP-1 test. Of particular clinical relevance, PAMG-1 outperformed IGFBP-1 in the equivocal group, which comprised patients with uncertain rupture of membranes (sensitivity, 96.0% vs. 73.9%; specificity, 98.9% vs. 77.8%; PAMG-1 vs. IGFBP-1 tests, respectively). Conclusions: Compared with its performance in women with known membrane status, the accuracy of the IGFBP-1 test decreases significantly when used on patients whose membrane status is unknown. In this latter clinically relevant population, the PAMG-1 test has higher accuracy than the IGFBP-1 tes

    BMJ Open

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    INTRODUCTION: The prevalence of postnatal depression (PND) is significant: reaching up to 20% in the general population. In mechanistic terms, the risk of PND lies in an interaction between a maternal psychophysiological vulnerability and a chronic environmental context of stress. On the one hand, repetition of stressor during pregnancy mimics a chronic stress model that is relevant to the study of the allostatic load and the adaptive mechanisms. On the other hand, vulnerability factors reflect a psychological profile mirroring mindfulness functioning (psychological quality that involves bringing one's complete and non-judgemental attention to the present experience on a moment-to-moment basis). This psychological resource is linked to protective and resilient psychic functioning. Thus, PND appears to be a relevant model for studying the mechanisms of chronic stress and vulnerability to psychopathologies.In this article, we present the protocol of an ongoing study (started in May 2017). METHODS AND ANALYSIS: The study is being carried out in five maternities and will involve 260 women. We aim to determine the predictive psychobiological factors for PND emergence and to provide a better insight into the mechanisms involved in chronic stress during pregnancy. We use a multidisciplinary approach that encompasses psychological resources and biophysiological and genetic profiles in order to detect relevant vulnerability biomarkers for chronic stress and the development of PND. To do so, each woman will be involved in the study from her first trimester of pregnancy until 12 months postdelivery. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ile de France III Ethics Committee, France (2016-A00887-44). We aim to disseminate the findings through international conferences and international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03088319; Pre-results

    The ANTENATAL multicentre study to predict postnatal renal outcome in fetuses with posterior urethral valves: objectives and design

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    Abstract Background Posterior urethral valves (PUV) account for 17% of paediatric end-stage renal disease. A major issue in the management of PUV is prenatal prediction of postnatal renal function. Fetal ultrasound and fetal urine biochemistry are currently employed for this prediction, but clearly lack precision. We previously developed a fetal urine peptide signature that predicted in utero with high precision postnatal renal function in fetuses with PUV. We describe here the objectives and design of the prospective international multicentre ANTENATAL (multicentre validation of a fetal urine peptidome-based classifier to predict postnatal renal function in posterior urethral valves) study, set up to validate this fetal urine peptide signature. Methods Participants will be PUV pregnancies enrolled from 2017 to 2021 and followed up until 2023 in >30 European centres endorsed and supported by European reference networks for rare urological disorders (ERN eUROGEN) and rare kidney diseases (ERN ERKNet). The endpoint will be renal/patient survival at 2 years postnatally. Assuming α = 0.05, 1–β = 0.8 and a mean prevalence of severe renal outcome in PUV individuals of 0.35, 400 patients need to be enrolled to validate the previously reported sensitivity and specificity of the peptide signature. Results In this largest multicentre study of antenatally detected PUV, we anticipate bringing a novel tool to the clinic. Based on urinary peptides and potentially amended in the future with additional omics traits, this tool will be able to precisely quantify postnatal renal survival in PUV pregnancies. The main limitation of the employed approach is the need for specialized equipment. Conclusions Accurate risk assessment in the prenatal period should strongly improve the management of fetuses with PUV

    The painting taken in letters : or how perceive the third visual structure in art

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    La présente recherche s’attache à mettre en relief l’un des aspects particuliers de l’art : la peinture.Il s’agit, à la suite d’une pratique personnelle cultivée depuis plu¬sieurs années et explorant les relations complexes entre expression plastique et intégration de la lettre écrite, de réfléchir sur l’entité singulière qu’est l’écriture.C’est alors que, conjuguant le travail plastique et le travail de recher¬che, se conduit cette étude dont l’objectif se fonde et se développe autour de la question des rapports texte/image au sein des œuvres peintes traversant et construisant l’ensemble de l’histoire de l’art occidental.En 1924, l’artiste Paul Klee (1879-1940) déclare :« Ecrire et dessiner sont identiques en leur fond » . Un cloisonnement entre les disciplines littéraires et pictu¬rales fait néanmoins foi depuis des siècles et ce malgré l’étymologie commune des ter¬mes « écrire » et « dessiner » formulée à partir du mot grec grapheïn . Mais, au regard des pratiques artistiques menées par les cubistes, tels le po¬choir ou le papier collé, par les futuristes, tel le bouleversement des co¬des de composition et de mise en page, par Dada, telle la destruction du langage, par les surréalistes, telle l’« écriture automatique », par les lettristes, telle la prise en compte de la singularité de la lettre même, et par l’Art conceptuel envisageant l’écrit comme une matière à l’œuvre, nous voyons que les liens tissés entre le domaine iconique et le domaine textuel se renou¬vellent cons¬tamment et mérite un examen approfondi.Ainsi, notre recherche organise et analyse les différents usages concédés à la lettre par l’univers pictural. Elle met en valeur son intégration, son implication, son évolution et sa résonnance dans le champ visuel. La tra¬duction des modalités plastiques de l’écriture, après l’observation d’œuvres contemporaines comme celles de Jenny Holzer, de Claude Closky ou de Ta¬nia Mouraud, fait émerger l’indice d’une nouvelle organisation actuelle des codes graphiques qui, après le règne de la figuration et celui de l’abstraction en art, explore le graphème comme une matière picturale première et à part entière. Paul KLEE, Théorie de l’art moderne, Gallimard, Paris, (1956), 1998, p. 58. Bruno DUBORGEL, Figures du grapheïn, Publications Universitaires de Saint-Etienne, Saint-Etienne, 2000, pp. 11-12. « Grapheïn… A/ Primitivement, égratigner, écorcher… B/ Par suite, tracer des signes pour écrire ou pour dessiner, d’où : I/ Graver… II/ Ecrire… […] Le verbe graphô est attesté depuis Homère. Sens : “érafler” (Cf. Iliade 17, 599), tracer, dessiner, écrire, d’où rédiger un décret, etc. », extraits du Dictionnaire Grec-Français d’André Bailly (16e édition, Hachette, Paris, 1950) et du Dictionnaire étymologique de la langue grecque de Paul Chantraine (Histoire des mots, Klincksieck, Paris, 1968).It’s a question of one of peculiarities of art : the painting.It’s a question, following a personal practice cultivated for many years and investigating the complex relations between plastic expression and integration of the written letter, of reflecting about the singular entity that is the writing.It’s then that, conjugating the plastic work and the research work, behaves this study which the objective establishes and develops around the question of relationships text/picture within the painted works crossing and building the whole western art history.Everything begins with the proverb thrown, in 1924, by the artist Paul Klee (1879-1940) declaring that :« To write and to draw are identical in their bottom » .A subdivision between the literary and pictorial disciplines been va¬lid for centuries and it in spite of the common etymology of the terms « to write » and « to draw » formulated from the greek grapheïn word. Neverthe¬less, towards the artistic practices led by the cubists, such the sten¬cil or the stuck paper, by the futurists, such the upheaval of the codes of composition and layout, by Dada, such the destruction of the language, by the surrealists, such the automatic writing, by the lettrist, such the conside¬ration of the visual peculiarity of the letter, and by the Conceptual art envisaging the paper as subject in the work, we see that the links weaved bet¬ween the iconic domain and the textual domain are constantly renewed and deserve a detailed examination.So, our research organizes and analyzes the various practices granted literally within the pictorial universe. It considers its integration, its impli¬cation, its evolution and its resonnance in the field of vision. The translation of the pictorial modalities of the writing, after the observation of works contemporary as those of Jenny Holzer, Claude Closky, Tania Mouraud, brings to the foreground the indication of a new current organization of the graphic codes which, after the reign of the representation and that of the abstraction in art, investigates the grapheme as the first and full pictorial subject. Paul KLEE, Theory of the modern art, Gallimard, Paris, (1956), 1998, p. 58. Bruno DUBORGEL, Figures of the grapheïn, University Publications of Saint-Etienne, Saint-Etienne, 2000, pp. 11-12. « Grapheïn… A/ Primitively, graze, skin… B/ Following, to draw signs to write or to draw, from : I/ Graze… II/ to write… […] The graphô verb is attested since Homère. Sense : « scratch » (Cf. Iliade 17, 599), to draw, to write, where from to draft a decree, etc. », extracted from the André Bailly's Greek-French Dictionary (16th publishing, Hachette, Paris, 1950) and of the Etymological Dictionary of the Greek language of Paul Chantraine (History of the words, Klincksieck, Paris, 1968)

    Rupture prématurée des membranes entre 24 et 34 semaines d'aménorrhée (comparaison d'une antibiothérapie au long cours et d'une antibiothérapie courte)

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    Les ruptures prématurées des membranes (RPM) survenant entre 24 et 34 SA concernent 1 % des grossesses mais sont responsables d'un tiers des accouchements prématurés. La principale complication redoutée est la survenue d'une chorioamniotite et d'une infection bactérienne néonatale précoce. Une antibiothérapie est instaurée dès la survenue de la rupture des membranes mais la durée et le type d'antibiotiques ne sont pas clairement définis parmi les recommandations actuelles. Jusqu'en 2009, les patientes hospitalisées à la maternité du CHU de Bordeaux pour RPM entre 24 et 34 SA bénéficiaient d'une antibiothérapie prolongée jusqu'à l'accouchement. Devant l'émergence de bactéries résistantes dans nos services, nous avons décidé de modifier nos pratiques en appliquant les recommandations américaines et canadiennes qui préconisent une antibiothérapie d'une durée de 7 jours. Notre étude compare ainsi deux groupes de patientes sur une période de 3 ans (de 2008 à 2010) : un groupe (n = 72) ayant reçu une antibiothérapie prolongée (étude rétrospective) et un groupe (n = 61) ayant reçu une antibiothérapie courte (étude prospective). Nous avons observé qu'une antibiothérapie au long cours ne permet pas de prolonger la grossesse ni de prévenir une chorioamiolite ou une infection bactérienne néonatale précoce par rapport à une antibiothérapie courte. Le groupe pour lequel nous avons instauré une antibiothérapie courte présente une diminution significative du nombre de chorioamniotite. Nous observons également une diminution du nombre de bactéries multi-résistantes. Ce protocole fait maintenant partie des habitudes de notre service mais il nous semblerait intéressant de déterminer la plus courte durée d'antibiothérapie nécessaire, voire même de montrer si l'utilisation d'une antibiothérapie est indispensable (notion actuellement remise en question par la dernière publication de la Cochrane Database).BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

    A kinetic mechanism inducing oscillations in simple chemical reactions networks

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