117 research outputs found
THE USE OF GLOBAL SENSITIVITY ANALYSIS FOR ASSESSING CAPABILITY OF THE MTG/FCI INSTRUMENT TO DETECT AEROSOLS
International audienceThe Flexible Combined Imager (FCI) is an instrument to be borne by the future geostationary meteorological satellite Meteosat Third Generation (MTG). A numerical simulator was set up to provide simulated outputs of the instrument. It includes top-of-atmosphere scene of upwelling spectral radiance obtained by a radiative transfer model in the clear atmosphere, and the transfer function of the FCI. The sensitivity of the sensor outputs to aerosol properties is studied by varying the inputs defining the scenes and their illumination. The Global Sensitivity Analysis (GSA) with the Sobol' decomposition is applied to the outputs of the simulator, yielding a ranking of the inputs with respect to their influence on the FCI numerical outputs. The results are presented for all visible and near infrared channels of the FCI for desert type of aerosols according to the OPAC database. The study highlights the most relevant channels for aerosol detection and characterization and gives assessment of the different sources of uncertainties in aerosol retrieval with such channels
Centre d’anthropologie sociale – CAS
Jean-Pierre Albert, directeur d’étudesAnne Bouchy, directrice d’études à l’EFEO La mort et les religions. Études comparatives Avec Marlène Albert-Llorca, Alain Ballabriga, Anny Bloch-Raymond, Marine Carrin, Patrizia Ciambelli, Jean-Louis Ormières, Valérle Robin, Guillaume Rozenberg, Harald Tambs-Lyche, Sébastien Tank-Storper, Claudine Vassas. Les séances ont été centrées sur le thème « Mort, religion et politique », avec deux orientations principales : Les enjeux des rites funéraires et de la..
Centre d’anthropologie sociale – CAS
Jean-Pierre Albert, directeur d’étudesAnne Bouchy, directrice d’études à l’EFEO La mort et les religions. Études comparatives Avec Marlène Albert-Llorca, Alain Ballabriga, Anny Bloch-Raymond, Marine Carrin, Patrizia Ciambelli, Jean-Louis Ormières, Valérle Robin, Guillaume Rozenberg, Harald Tambs-Lyche, Sébastien Tank-Storper, Claudine Vassas. Les séances ont été centrées sur le thème « Mort, religion et politique », avec deux orientations principales : Les enjeux des rites funéraires et de la..
Investigating the impact of captivity and domestication on limb bone cortical morphology: an experimental approach using a wild boar model
The lack of bone morphological markers associated with the human control of wild animals has prevented the documentation of incipient animal domestication in archaeology. Here, we assess whether direct environmental changes (i.e. mobility reduction) could immediately affect ontogenetic changes in long bone structure, providing a skeletal marker of early domestication. We relied on a wild boar experimental model, analysing 24 wild-born specimens raised in captivity from 6 months to 2 years old. The shaft cortical thickness of their humerus was measured using a 3D morphometric mapping approach and compared with 23 free-ranging wild boars and 22 pigs from different breeds, taking into account sex, mass and muscle force differences. In wild boars we found that captivity induced an increase in cortical bone volume and muscle force, and a topographic change of cortical thickness associated with muscular expression along a phenotypic trajectory that differed from the divergence induced by selective breeding. These results provide an experimental proof of concept that changes in locomotor behaviour and selective breeding might be inferred from long bones morphology in the fossil and archaeological record. These trends need to be explored in the archaeological record and further studies are required to explore the developmental changes behind these plastic responses
Designed Ankyrin Repeat Proteins provide insights into the structure and function of CagI and are potent inhibitors of CagA translocation by the Helicobacter pylori type IV secretion system
The bacterial human pathogen Helicobacter pylori produces a type IV secretion system ( cag T4SS) to inject the oncoprotein CagA into gastric cells. The cag T4SS external pilus mediates attachment of the apparatus to the target cell and the delivery of CagA. While the composition of the pilus is unclear, CagI is present at the surface of the bacterium and required for pilus formation. Here, we have investigated the properties of CagI by an integrative structural biology approach. Using Alpha Fold 2 and Small Angle X-ray scattering, it was found that CagI forms elongated dimers mediated by rod-shape N-terminal domains (CagI N ) prolonged by globular C-terminal domains (CagI C ). Three Designed Ankyrin Repeat Proteins (DARPins) K2, K5 and K8 selected against CagI interacted with CagI C with subnanomolar affinities. The crystal structures of the CagI:K2 and CagI:K5 complexes were solved and identified the interfaces between the molecules, thereby providing a structural explanation for the difference in affinity between the two binders. Purified CagI and CagI C were found to interact with adenocarcinoma gastric (AGS) cells, induced cell spreading and the interaction was inhibited by K2. The same DARPin inhibited CagA translocation by up to 65% in AGS cells while inhibition levels were 40% and 30% with K8 and K5, respectively. Our study suggests that CagI C plays a key role in cag T4SS-mediated CagA translocation and that DARPins targeting CagI represent potent inhibitors of the cag T4SS, a crucial risk factor for gastric cancer development.Bases structurale du système de secretion de type IV d'Helicobacter pyloriBases structurales et moléculaires de l'exploitation de l'integrin a5ß1 par le système de sécrétion de type IV d'Helicobacter pylor
Metabolic reprogramming involving glycolysis in the hibernating brown bear skeletal muscle
Background: In mammals, the hibernating state is characterized by biochemical adjustments, which include metabolic rate depression and a shift in the primary fuel oxidized from carbohydrates to lipids. A number of studies of hibernating species report an upregulation of the levels and/or activity of lipid oxidizing enzymes in muscles during torpor, with a concomitant downregulation for glycolytic enzymes. However, other studies provide contrasting data about the regulation of fuel utilization in skeletal muscles during hibernation. Bears hibernate with only moderate hypothermia but with a drop in metabolic rate down to ~ 25% of basal metabolism. To gain insights into how fuel metabolism is regulated in hibernating bear skeletal muscles, we examined the vastus lateralis proteome and other changes elicited in brown bears during hibernation. Results: We show that bear muscle metabolic reorganization is in line with a suppression of ATP turnover. Regulation of muscle enzyme expression and activity, as well as of circulating metabolite profiles, highlighted a preference for lipid substrates during hibernation, although the data suggested that muscular lipid oxidation levels decreased due to metabolic rate depression. Our data also supported maintenance of muscle glycolysis that could be fuelled from liver gluconeogenesis and mobilization of muscle glycogen stores. During hibernation, our data also suggest that carbohydrate metabolism in bear muscle, as well as protein sparing, could be controlled, in part, by actions of n-3 polyunsaturated fatty acids like docosahexaenoic acid. Conclusions: Our work shows that molecular mechanisms in hibernating bear skeletal muscle, which appear consistent with a hypometabolic state, likely contribute to energy and protein savings. Maintenance of glycolysis could help to sustain muscle functionality for situations such as an unexpected exit from hibernation that would require a rapid increase in ATP production for muscle contraction. The molecular data we report here for skeletal muscles of bears hibernating at near normal body temperature represent a signature of muscle preservation despite atrophying conditions
Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.
RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Vers une recherche-création : explorer la portée transformatrice des récits dans les relations au milieu de vie
International audienceThis article presents research-creation as a mean for renewing the links between arts and social sciences, through a dialogue between texts, bodies and environments. Starting with the narration of different art-science residencies, we question their transformative potential at the confluence of esthetical, cognitive and sensitive dimensions. A step aside from usual definitions of research-creation, the conception developed here is defined as a practice that highlights the documentation of reality in order to test its limits. Face to contemporary ecological crises, and associated challenges, we follow the cracks between different academic discursive norms to engage in the production of new situations, understood as plural and carnal reasoning practices embedded in sensed and lived environmental matrix.Cet article aborde la recherche-création comme support pour reformuler les rapports entre arts et sciences sociales. Plus précisément il s'agit d'interroger la mise en récit des expériences plurielles à propos du territoire compris comme milieu de vie, impliquant les savoirs et imaginaires, le corps sentant et les autres vivants. Nous nous appuyons sur plusieurs expérimentations réalisées au cours de résidences art-science en France pour nous interroger sur leur portée transformatrice, au croisement entre des dimensions cognitives et sensibles : faisant un pas de côté par rapport à la généalogie de la notion de recherche-création, l'approche proposée ici se définit comme pratique valorisant la documentation du réel, dans l'optique d'en éprouver les limites. Face aux défis sociaux posés par les crises écologiques contemporaines, il s'agit dès lors, en nous installant dans les interstices des normes discursives propres à chaque discipline, de prolonger les recherches-actions du côté de nouvelles formes d'engendrement des situations. Impliquant l'environnement vécu pleinement sur le plan corporel, ces expérimentations participent ainsi à redonner au raisonnement, comme activité, sa pluralité et ses incarnations. Abstract This article discusses research-creation as a way to reformulate relationships between the arts and the social sciences. More precisely it explores narration as a medium to bring to light plurality of experiences about the territory as a living environment, involving knowledge and imaginary, the sentient body and other living beings. We rely on several experiments conducted during art-science residencies in France to question their transformative potential, at the crossroads between cognitive and sensitive dimensions: taking a step aside from the genealogy of the notion of research-creation, the approach proposed here is defined as a practice that documents reality in order to test its limits. Faced with the social challenges posed by contemporary ecological crises, we settle in the interstices between disciplinary discursive norms, to extend action-research, toward the creation of situations in a material, fully lived, constantly re-emerging environment. These experiments thus contribute to restore reasoning as an embodied and plural activity
Evaluation des performances de l'échoendoscopie pancréatique dans l'indication opératoire des tumeurs intracanalaires papillaires et mucineuses du pancréas
INTRODUCTION: Les TIPMP doivent être surveillées jusqu'à l'apparition de signes de malignité en IRM ou EEP. L'OBJECTIF DE L'ETUDEétait d'évaluer les performances de l'EEP dans les critères d'indication chirurgicale à partir du compte rendu d'anatomopathologie des pancratectomies de TIPMP. MATERIEL ET METHODE: Cette étude rétrospective, incluant les patients ayant eu une pancréatectomie pour TIPMP entre 2000 et 2012 dans 4 hôpitaux. Si un examen d'imagerie (EEP, IRM ou TDM) retrouvait un critère de malignité définis par le consensus de 2012, le patient était considéré comme ayant un critère péjoratif . RESULTATS: Un cancer était retrouvé chez 36,6% des 131 patients inclus, soit 58% de ceux ayant une atteinte mixte ou du canal principal et 20% des canaux secondaires. L'EEP retrouvait des critères péjoratifs chez 71% des patients, dont 29,8% avaient un cancer contre 42,2%. Chez ceux n'ayant pas de critères péjoratifs, 22,1% des patients n'avaient pas de cancer et 6,9% en avaient. Les critères péjoratifs retrouvés en EEP avaient une bonne sensibilité (0,81) et une mauvaise spécificité (0,35). Ceux ayant la meilleure sensibilité ou composante solide (sen=0,95), un Wirsung > 10mm (spé=0,96), une cytologie suspecte (spé=0,97). Un module mural ou un Wirsung ;esur2 entre 5 et 9 mm avaient une sensibilité correcte (respectivement 0,73 et 0,67). CONCLUSION: Notre travail réalisé en centres experts confirme que l'EEP est un examen clé dans l'indication chirurgicale des TIPMIP qui doit rester pluridisciplinaire. Un compte rendu standardisé d'EEP paraît indispensableAIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocSudocFranceF
« Recréer le Ballet royal de la Nuit. Entretien avec Sébastien Daucé et Thomas Leconte »
International audienc
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