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Intubate patients with sepsis before midnight or do it when the time comes?
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L'Encyclopédie des communautés et pratiques communautaires: Extraits choisis – Édition 2025
No full textInternational audienceL’Encyclopédie des communautés et pratiques communautaires propose un corpus inédit de connaissances sur les sources, formes et modes d’organisations collaboratives et collectives d’hier, d’aujourd’hui et de demain.Rassemblant des spécialistes internationaux de diverses disciplines, dont le droit, la sociologie, l’économie ou les sciences de la gestion, cet ouvrage de référence constitue une ressource précieuse pour comprendre et analyser les fondements et fonctionnements des communautés qui imaginent de nouvelles façons de vivre ensemble.Ainsi les communautés dont il est question ici sont celles qui s’articulent autour de trois axes : la défense d’un intérêt communautaire, comme la protection d’un espace naturel ; le partage d’un bien privatif ou commun, comme les habitats participatifs ; ou encore la production des connaissances, telle l’encyclopédie Wikipédia.Publiée en libre accès, cette encyclopédie évolutive, dont sont présentés ici les premiers extraits, a vocation à s’enrichir continuellement sous la supervision d’un comité scientifique international et pluridisciplinaire, afin d’offrir unevision plurielle et engagée des communautés et pratiques communautaires
Glacial-interglacial changes in Antarctic Intermediate Water advection in the Southeast Pacific during the last 787 kyr
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L'engagement religieux de l'entreprise : un engagement pour la foi ou pour le marché ?
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Aerosol spectral optical properties in the Paris urban area and its peri-urban and forested surroundings during summer 2022 from ACROSS surface observations
No full textInternational audienceAbstract. The complex refractive index (CRI; n−ik) and the single scattering albedo (SSA) are key parameters driving the aerosol direct radiative effect. Their spatial, temporal, and spectral variabilities in anthropogenic–biogenic mixed environments are poorly understood. In this study, we retrieve the spectral CRI and SSA (370–950 nm wavelength range) from in situ surface optical measurements and the number size distribution of submicron aerosols at three sites in the greater Paris area, representative of the urban city, as well as its peri-urban and forested rural environments. Measurements were taken as part of the ACROSS (Atmospheric Chemistry of the Suburban Forest) campaign in June–July 2022 under diversified conditions: (1) two heatwaves leading to high aerosol levels, (2) an intermediate period with low aerosol concentrations, and (3) an episode of long-range-transported fire emissions. The retrieved CRI and SSA exhibit an urban-to-rural gradient, whose intensity is modulated by the weather conditions. A full campaign average CRI of 1.41−0.037i (urban), 1.52−0.038i (peri-urban), and 1.50−0.025i (rural) is retrieved. The imaginary part of the CRI (k) increases and the SSA decreases at the peri-urban and forest sites when exposed to the influence of the Paris urban plume. Values of k > 0.1 and SSA < 0.6 at 520 nm are related to a black carbon mass fraction larger than 10 %. Organic aerosols are found to contribute to more than 50 % of the aerosol mass and up to 10 % (urban), 17 % (peri-urban), and 22 % (forest) of the aerosol absorption coefficient at 370 nm. A k value of 0.022 (370 nm) was measured at the urban site for the long-range-transported fire episode
Conception de films photomagnétiques ultra-minces par électrodéposition de complexes Fe 4 Co 4 pontés au cyanure commutables
No full textInternational audiencePreparing thin-films of molecular polymetallic materials remains one of the current limitations in the implementation of polymetallic complexes into devices. The hurdle was tackled here using an electrochemical route for depositing the cyanido-bridged polymetallic complex {Tl[Fe II (2-TPhTp)(CN) 3 ] 4 [Co III (Tp)] 3 [Co II (Tp)]}(1) (where 2-TPhTp = [4-(2thienyl)Phenyl]tris(pyrazol-1-yl)borate ; and Tp = hydrotris(pyrazol-1-yl)borate), functionalized with thiophene groups, on conductive surface (Pt/mica). Cyclic voltammograms show that the electrochemical pattern of the cubic units is maintained in the electropolymerized film, notably with four quasi reversible successive Fe III /Fe II redox events. Assessing the morphology and the chemical composition of the resulting thin-film by Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS) experiments respectively, reveal a homogenous deposition (thickness of ca. 20 nm) showing the expected metallic ratio. More importantly, X-ray Absorption Spectroscopy (XAS) and X-ray Magnetic Circular Dichroism (XMCD) measurements demonstrate that the photo-induced metal-metal electron transfer is preserved in the film. XMCD signals of Fe and Co atoms at their L 2,3 absorption edges both indicate an equivalent conversion of Fe II -CN-Co III diamagnetic pairs into Fe III -CN-Co II paramagnetic ones under laser light irradiation below 62 K. As for the photomagnetic complex, the phenomenon is reversible: the metastable Fe III -CN-Co II paramagnetic pairs thermally relax to the diamagnetic ground state upon heating to room temperature.La préparation de couches minces de matériaux polymétalliques moléculaires reste l'une des limitations actuelles dans la mise en œuvre de complexes polymétalliques dans des dispositifs. Cet obstacle a été abordé ici en utilisant une voie électrochimique pour déposer le complexe polymétallique ponté cyanido {Tl[Fe II (2-TPhTp)(CN) 3 ] 4 [Co III (Tp)] 3 [Co II (Tp)]}(1) (où 2-TPhTp = [4-(2thiényl)phényl]tris(pyrazol-1-yl)borate ; et Tp = hydrotris(pyrazol-1-yl)borate), fonctionnalisé avec des groupes thiophène, sur une surface conductrice (Pt/mica). Les voltampérogrammes cycliques montrent que le motif électrochimique des unités cubiques est maintenu dans le film électropolymérisé, notamment avec quatre événements redox Fe III /Fe II successifs quasi réversibles. L'évaluation de la morphologie et de la composition chimique du film mince obtenu, par microscopie à force atomique (AFM) et spectroscopie de photoélectrons X (XPS), révèle un dépôt homogène (épaisseur d'environ 20 nm) présentant le rapport métallique attendu. Plus important encore, les mesures de spectroscopie d'absorption des rayons X (XAS) et de dichroïsme circulaire magnétique des rayons X (XMCD) démontrent que le transfert d'électrons métal-métal photo-induit est préservé dans le film. Les signaux XMCD des atomes de Fe et de Co à leurs seuils d'absorption L 2,3 indiquent tous deux une conversion équivalente des paires diamagnétiques Fe II -CN-Co III en paires paramagnétiques Fe III -CN-Co II sous irradiation laser à une température inférieure à 62 K. Concernant le complexe photomagnétique, le phénomène est réversible : les paires paramagnétiques métastables Fe III -CN-Co II se relaxent thermiquement et reviennent à l'état fondamental diamagnétique lors du chauffage à température ambiante
Le droit français des pratiques commerciales déloyales inter-entreprises : état des lieux et analyse critique
No full textInternational audienceThe purpose of this article is to present French unfair trade practices law in b2b relationships in the light of the creation of European super purchasing bodies and to discuss certain avenues for both national and European reform that have been proposed in recent months in the context of the future Egalim 4 law and a possible European Egalim.Le présent article a pour objet de présenter le droit français des pratiques commerciales déloyales inter-entreprises, à l’aune de la création des supercentrales d’achat européennes, et de discuter certaines pistes de réformes tant nationales qu’européennesqui ont pu être proposées ces derniers mois, dans le cadre de la future loi Egalim 4 et d’un éventuel Egalim européen
Calibration of Upper Air Water Vapour Profiles Using the IPRAL Raman Lidar and ERA5 Model Results and Comparison to GRUAN Radiosonde Observations
No full textInternational audienceAccurate measurements of upper troposphere humidity are essential to enhance understanding of contrail formation and guiding mitigation efforts. This study evaluates the ability of the IPRAL Raman Lidar, located south of Paris, to provide high-resolution water vapour mixing ratio (WVMR) profiles at contrail-relevant altitudes. Raman signals are screened on hourly bases, and a universal calibration method, independent of acquisition mode, is proposed towards operational Lidar water vapour profiles, using co-located ERA5 data. Calibration factors are derived from comparisons between 4 and 6 km, and nightly coefficients determined from hourly factors. Instrumental stability is monitored through the temporal evolution of calibration factors, and stable-period medians are adopted as final values. The uncertainty of calibrated WVMR profiles is assessed by comparison with GRUAN processed Meteomodem M10 radiosondes and ERA5 data. Results show a high agreement (>90%), with IPRAL exhibiting a small negative bias (~10%) below 8 km, reducing to ~5% up to 10.5 km to radiosondes. ERA5 systematically underestimates water vapour at cruise altitudes, with a dry bias increasing from 10% at 9 km to >20% at 11 km. Recent IAGOS corrections to ERA5, improving supersaturation representation, are validated over Paris. This calibrated Lidar data set supports improved atmospheric modelling and contributes to future air traffic management strategies
How Well Do AMIP6 and CMIP6 Reproduce the Specific Extreme El Niño Teleconnections to North America?
No full textInternational audienceExtreme El Niño events (e.g., 1982–1983, 1997–1998) are characterized by strong, eastward‐shifted warm Sea Surface Temperature anomalies, and a southward migration of the eastern Pacific Inter‐Tropical Convergence Zone (ITCZ) to the equator. Using an ensemble simulation with a single AMIP6 model, Beniche et al. (2024, https://doi.org/10.1038/s41598‐024‐52580‐9 ) suggested that such events uniquely yield an eastward shift of the Pacific‐North American (PNA) teleconnection pattern, with specific impacts over North America. Here, we first examine the robustness of these results in 135 ensemble members from 23 different AMIP6 models. The specific, eastward‐shifted extreme El Niño teleconnection pattern is robust in all models but one. It is also highly reproducible across years and ensemble members, due to stronger teleconnection amplitude than that of internal atmospheric noise. This yields specific, predictable impacts (defined as 0.5 STD) such as warm conditions over Northeast America (69% chances), and wet anomalies over California (77%) and Florida (97%). We then show that 26 out of the 42 CMIP6 models we examined reproduce extreme El Niño events, defined as El Niño events associated with large eastern Pacific rainfall anomalies. These models tend to have a weaker cold tongue bias than the rest of CMIP6. Despite a degradation in performance from AMIP6 to CMIP6, 18 out of the 26 selected models capture the specific extreme El Niño teleconnections, albeit with some underestimation of wet anomalies over California and Florida. We end by discussing implications for future North American climate projections based on CMIP6
A versatile integrated protocol to extract organic balms from archaeological linen: A new way to provide reliable radiocarbon dating for contaminated textile
No full textInternational audienceRadiocarbon dating of archaeological textiles can be particularly challenging when exogenous organic balms were deposited on their surface, as these organic mixtures can sometimes contain radiocarbon-depleted materials such as fossil bitumen. This is a key issue for radiocarbon dating of linen fragments used in the wrapping of Egyptian mummies, as bitumen has been repeatedly identified in several contexts. Radiocarbon dating of contaminated fragments can be facilitated by an analytical approach involving textile surface analysis by ATR-IR (Attenuated Total Reflection – Infrared Spectroscopy) to diagnose the state of contamination observed on each fragment, followed by a three-step organic extraction to remove all chemical families identified. This study was organized in two parts. First, mock-up samples were prepared, made of modern linen and experimental balms, to develop an integrated methodology based first on ATR-IR diagnosis for the state of contamination of textile, then on a solvent extraction to remove organic contaminants. The solvent extraction was monitored by ATR-IR and radiocarbon dating to control the complete removal of fossil compounds. The extraction protocol chosen is a three-step procedure (3x CHCl3, then 3x hexane, then 3x MeOH), which can be tunable depending on the state and the nature of organic contamination on the textile. This new integrated methodology, which can be used in a versatile way to ensure reliable radiocarbon dating of linen archaeological textiles, was then applied to samples collected from an Egyptian child mummy conserved in Musée des Confluences, embalmed using a process that included the use of fossil bitumen. Thanks to this new protocol, we were able to date this mummy to the Late Period of Egypt