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Global Mapping of Concurrent Hazards and Impacts Associated With Climate Extremes Under Climate Change
No full textInternational audienceClimate‐related extreme events impose a heavy toll on humankind, and many will likely become more frequent in the future. The compound (joint) occurrence of different climate‐related hazards and impacts can further exacerbate the detrimental consequences for society. By analyzing postprocessed data from the Inter‐Sectoral Impact Model Intercomparison Project, we provide a global mapping of future changes in the compound occurrence of six categories of hazards or impacts related to climate extremes. These are: river floods, droughts, heatwaves, wildfires, tropical cyclone‐induced winds and crop failures. In line with the existing literature, we find sharp increases in the occurrence of many individual hazards and impacts, notably heatwaves and wildfires. Under a medium‐high emission scenario, many regions worldwide transition from chiefly experiencing a given category of hazard or impact in isolation to routinely experiencing compound hazard or impact occurrences. A similarly striking change is projected for the future recurrence of compound hazards or impacts, with many locations experiencing specific compound occurrences at least once a year for several years, or even decades, in a row. In the absence of effective global climate mitigation actions, we may thus witness a qualitative regime shift from a world dominated by individual climate‐related hazards and impacts to one where compound occurrences become the norm
Expert consensus‑based clinical practice guidelines for nutritional support in the intensive care unit: the French Intensive Care Society (SRLF) and the French-Speaking Group of Pediatric Emergency Physicians and Intensivists (GFRUP)
No full textInternational audienceThe objective of this work was to develop guidelines for nutritional support in critically ill adults and children (excluding neonates and burn patients) unable to maintain an adequate oral intake. We aimed to provide up-to-date recommendations based on high-level evidence including the results of recent landmark randomized controlled trials. Experts from the French Intensive Care Society (SRLF), the French Society of Clinical Nutrition and Metabolism (SFNCM), and the French-Speaking Group of Pediatric Emergency Physicians and Intensivists (GFRUP) used the GRADE methodology to develop the guidelines. Twenty-four Patient Intervention Comparator Outcome (PICO) questions were identified, resulting in 34 adult and 29 pediatric recommendations. Of the 34 recommendations for adults, three were based on high-level evidence, 12 on moderate-level evidence, and 19 on expert opinion. The corresponding numbers for the 29 pediatric recommendations were one, five, and 23. All recommendations achieved strong agreement among the experts. These guidelines emphasize the importance of individualized nutritional support strategies that incorporate recent high-quality evidence to optimize the outcomes of critically ill patients
Embedded Feature-Line Points Tracker for real-time Visual Odometry-based system
No full textInternational audienceLine segment tracker is a fundamental technique in computer vision that follows linear structures in man-made environments, playing a crucial role in Visual Odometry (VO) applications. Although feature-line segments are more efficient than feature-corners in image understanding and geometric inference by enhancing orientation change cues, they face critical challenges such as over-segmentation, occlusions, and ambiguities. In this paper, we address line tracking issues by leveraging feature-line properties. We propose an efficient sparse Lucas-Kanade Optical Flow (OF)-based method to track line segment points. By utilizing the line-fitting model, the anchor, and the gradient properties, we enhance optical flow predictions through three methods: i) an enhanced RANSAC method that uses the segment anchor to reject outliers, ii) a minimization technique that adjusts OF predictions based on anchor direction and gradient, and iii) a flow correction method that integrates both RANSAC and minimization approaches. To meet real-time and embedded constraints, we adopt the Algorithm Architecture Adequacy (A3) methodology for suitable implementation in GPU-based heterogeneous architecture. We also conduct qualitative and quantitative benchmarks in indoor/outdoor environments against state-of-the-art VO front-ends. The results demonstrate the effectiveness of our proposed methods, highlighting the efficiency of tracking line segments via the anchor in real-time at about 50 fps within GPU-based embedded heterogeneous architectures
Better than Multi-Model Means: combining climate models using multivariate graph cuts for improved CMIP6 projections
No full textInternational audienceVarious approaches have been proposed to combine individual climate models and extract a robust signal from an ensemble, such as the Multi-Model Mean or the weighted Multi-Model Mean. However, they often rely on weights that are applied to models globally, overlooking the fact that individual models often demonstrate strengths in specific regions. This suggests that a more localized approach could improve climate projections based on models ensembles. So far, the only approach that really exploits the regional strengths of different models over multi-decadal timescales is the graph cuts approach (Thao et al., 2022). It consists in selecting for each grid point the most appropriate model, while at the same time considering the overall spatial consistency of the resulting field. Although this method showed encouraging results, outperforming other combination approaches, it is limited to optimizing for one variable, resulting in an inconsistent model selection for each and thus a loss of the multivariate relationships observed in the models. For instance it is known that precipitation and temperature are physically linked. Therefore having an independent model combination for each variable can result in inconsistencies. Moreover, the method was only applicable to multi-decadal averages, not allowing for retrieving distributional properties of the combined models such as extreme events. Here we present a series of improvements of graph cuts enabling to combine distributions of daily-means while preserving multivariate relationships, thus better capturing the complete span of climate dynamics. Using the Hellinger distance to measure model performance, we are able to select, at each grid location, the model that best represents the joint distribution of the target variables while minimizing the apparition of unrealistic discontinuities in the resulting fields. The resulting projections display more realistic extremes and compound events representations.   REFERENCES  Thao, S., Garvik, M., Mariethoz, G., & Vrac, M. (2022). Combining global climate models using graph cuts. Climate Dynamics, February. https://doi.org/10.1007/s00382-022-06213-
Second-Line Uterotonics for Uterine Atony: A Randomized Controlled Trial
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Exploratory research on occupational exposures and breast cancer risk in the CECILE study
No full textInternational audienceObjectives In ‘exploratory mode', to examine associations between occupational exposure to 49 prevalent agents and breast cancer risk. Methods In a French population-based case–control study on breast cancer (2005–2007), lifetime occupational histories of 1230 incident cases and 1315 controls were collected. An industrial hygienist coded each job held by a participant. Job codes were subsequently linked to the Canadian job-exposure matrix, and exposure level estimates for numerous agents were generated. Multivariable unconditional logistic regression was used to estimate associations between occupational exposure to 49 prevalent agents and breast cancer risk, adjusting for established breast cancer risk factors and selected sociodemographic covariates. Results Increased ORs, ranging between 1.33 and 2.39, were observed for women in the highest tertile of cumulative exposure versus unexposed for the following 12 agents: sodium carbonate, synthetic fibres, wool fibres, silk fibres, organic dyes and pigments, plastic dusts, plastics pyrolysis fumes, ozone, nitrogen oxides, anaesthetic gases, aliphatic ketones and mononuclear aromatic hydrocarbons. When stratified by menopausal status, the ORs for many of these agents were stronger among premenopausal versus postmenopausal women. Conclusions These findings suggest the possible role of some occupational agents in the aetiology of breast cancer. Further studies, based on large sample sizes and high-quality exposure assessment, are needed to confirm our findings
De la distribution de la matière organique dans le système solaire
No full textThe presence of organic matter is a condition necessary to assess habitability in the solar system. The survey I conduct is to understand its distribution, and thus its sources and its sinks. This could lead to the detection of biosignatures. In this manuscript, I described my past investigations that led to the first detection of organic molecules on Mars. To achieve this, I worked both on in situ data analysis (Curiosity rover), and on laboratory analyses on simple and complex analog samples. The parent molecules present at Mars’ surface are hypothesized, however, their origin is unknown: it could be from meteoritic infall, or formed on Mars through atmospheric, hydrothermal or biological processes. If today a significant number of astrochemists look at Mars and numerous space probes continue to study the red planet, today, Jupiter and Saturn gain a certain notoriety: their icy satellites Europa, Enceladus or Titan hold a high potential in their possibility to host life. The Dragonfly space mission will explore the diverse environments at Titan from 2034 and I am the PI of the French hardware contribution to this mission: the gas chromatograph. From this expertise, we are preparing further exploration probes to investigate ocean worlds Europa and Enceladus. In the same way that I do for my Mars’ studies, I am looking for terrestrial analog environments for those bodies, to prepare both the science and the technical aspects of future missions to explore the habitability of those icy satellites.La présence de matière organique est une condition nécessaire à l’habitabilité des corps du système solaire. Comprendre sa distribution, et par là-même ses sources et ses puits, est l’enquête que je mène. Cette enquête pourrait in fine mener à la détection de biosignatures. Dans ce manuscrit je décris mes travaux passés qui ont abouti à la première détection de molécules organiques sur Mars. Pour cela, je travaille autant à l’analyse de données in situ (rover Curiosity) qu’à des analyses en laboratoire sur des échantillons simples ou complexes. La forme initiale des molécules détectées sur Mars commence à être élucidée, mais leur origine est inconnue : apport météoritique ou formation sur Mars par des sources atmosphériques, hydrothermales ou biologiques. Si de nombreux exobiologistes ont leurs yeux rivés vers Mars et que de nombreuses missions continuent à étudier la planète rouge, aujourd'hui, Jupiter et Saturne sont sous le feu des projecteurs : leurs satellites glacés comme Europe, Encelade ou Titan ont un potentiel qui ne cesse de s'accroître quant à leur possibilité d'abriter des formes de vie. La mission Dragonfly explorera des environnements variés de Titan dès 2034 et je suis responsable de la fourniture hardware française à cette mission. De cette expertise, nous préparons des prochaines missions d’exploration des mondes-océans, Europe, Encelade. A l’instar des études martiennes, je recherche des environnements terrestres analogues pour préparer la science et la technique des futures missions d’exploration de l’habitabilité de ces satellites glacés
Sea ice, aerosols and clouds
No full textInternational audienceThis chapter discusses the intricate interplay between aerosols, clouds, and sea ice, emphasizing their roles in Earth's climate system. Aerosols, originating from both natural and anthropogenic sources, influence cloud formation and properties by acting as cloud condensation nuclei or ice nucleating particles. Clouds, particularly mixed-phase clouds, are crucial in polar regions, affecting energy exchanges and sea ice dynamics. In turn, changes in sea ice affect marine aerosol and biogenic gas emissions in the polar regions, impacting cloud formation. The atmospheric boundary layer over sea ice presents a unique environment, characterized by reduced turbulence and pronounced seasonal variations in radiation. Surface-based temperature inversions are common, especially in winter, impacting atmospheric stability and cloud formation. This chapter also describes the spatial and seasonal distribution of polar clouds, underscoring the observational challenges posed by extreme weather conditions and the limitations of current instrumentation and observation methods. A deeper understanding of the interactions between aerosols, clouds, and sea ice is crucial for enhancing climate models and improving predictions of future changes in polar regions
Securing the forest carbon sink for the European Union’s climate ambition
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Short CIAFU recommendations on the screening and management of asymptomatic bacteriuria in immunocompromised patients
No full textInternational audienceIntroduction: Immunosuppression refers to a functional or quantitative reduction in immune defenses, resulting in a diminished ability to combat microbial pathogens. Immunocompromised patients are at increased risk of severe infections, associated with elevated morbidity and mortality. In routine clinical practice, urine cultures are often performed systematically in patients considered at risk of infection, regardless of urinary symptoms, with the aim of detecting and subsequently treating potential asymptomatic bacteriuria. This study aimed to assess the clinical relevance of screening for and potentially treating asymptomatic bacteriuria in immunocompromised individuals.Materials and methods: A comprehensive literature search was conducted using PubMed and Medline, without restrictions on language or year of publication. This was complemented by an exploration of the scientific grey literature, including expert reports and guidelines from professional societies. Studies were selected using the following keywords: antibiotic treatment, urinary tract infection, asymptomatic bacteriuria, bacteriuria, pyelonephritis, cystitis, immunodeficiency, diabetes, renal transplant, neurogenic bladder, cirrhosis, pregnancy, and antimicrobial resistance. All abstracts and full-text articles were reviewed. The synthesis of the findings was subsequently evaluated by members of the CIAFU expert committee, who formulated the most consensual recommendation possible.Results: Across the reviewed literature, no clear benefit was identified in screening for or treating asymptomatic bacteriuria in immunocompromised patients.Conclusion: It is not recommended to screen for or treat asymptomatic bacteriuria in immunocompromised patients, except in specific, well-established scenarios. Treating asymptomatic bacteriuria does not reduce infection risk; rather, it increases the likelihood of adverse effects and contributes to the development of antimicrobial resistance, with its associated morbidity and mortality.Introduction: L’immunodépression, est la réduction des défenses immunitaires et donc l’incapacité à se défendre vis-à-vis d’un microorganisme. Les patients immunodéprimés ont un risque accru d’infections graves avec une morbi-mortalité plus importante. En pratique courante, des ECBU sont réalisés à titre systématique, en dehors de toute symptomatologie urinaire, chez ces patients jugés à risque infectieux, dans le but de dépister puis traiter une éventuelle colonisation urinaire. L’objectif de ce travail était de statuer sur l’intérêt de dépister et éventuellement traiter la colonisation urinaire chez les patients considérés comme immunodéprimés.Matériels et méthodes: Une recherche bibliographique a été effectué sur Pubmed et Medline sans exclusion du langage ou de l’année de publication, associée à une recherche dans la littérature grise scientifique (rapports d’experts et de sociétés savantes). Nous avons sélectionné les études en utilisant les mots clés antibiotic treatment, urinary tract infection, asymptomatic bacteriuria, bacteriuria, pyelonephritis, cystitis, immunodeficiency, diabetes, renal transplant, neurogenic bladder, cirrhosis, pregnancy, antimicrobial resistance. L’ensemble des résumés et articles ont été analysés. La synthèse de l’analyse a été revue par des membres du comité d’experts du CIAFU proposant la recommandation la plus consensuelle possible.Résultats: Dans les articles étudiés, l’intérêt à dépister ou traiter une colonisation urinaire chez les patients immunodéprimés n’a pas été mis en évidence.Conclusion: Au total, il est recommandé de ne pas dépister ni traiter une colonisation urinaire chez le patient immunodéprimé en dehors des situations déjà décrites. Traiter une bactériurie asymptomatique ne permet pas de réduire le risque infectieux mais présente au contraire un risque d’effets indésirables et contribue à l’aggravation de l’antibiorésistance et de la morbi-mortalité liée à celle-ci