HAL-Université de Bretagne Occidentale
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Consommation de demain : étude de l’acceptabilité et de l’adaptation des personnes âgées et des professionnels de santé à l'introduction des protéines d'algues marines en milieu hospitalier et en EHPAD
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Chronic Kidney Disease of unexplained cause (CKDx): a consensus statement by the Genes & Kidney Working Group of the ERA
No full textInternational audienceChronic kidney disease of unexplained cause (CKDx) is a diagnosis of exclusion. With an estimated global prevalence of at least 16–20% among CKD patients, CKDx poses a significant challenge to the field. To date, there is no established consensus on the definition of CKDx. Additionally, guidance on the diagnosis and reporting of CKDx remains lacking. CKDx is characterized by the inability to identify a specific etiology after comprehensive diagnostic evaluation, including laboratory tests, imaging, and histological or genetic analyses. This condition encompasses diverse clinical scenarios, which vary depending on the availability of diagnostic resources across healthcare systems. Notably, as the diagnostic yield of genetic testing in CKDx ranges from 11 to over 30% in the literature, it has become an integral part of the diagnostic armamentarium for patients with CKDx. This consensus statement of the working group ‘Genes&Kidney’ of the European Renal Association proposes a definition of CKDx, along with recommendations for the diagnostic approach and diagnostic reporting standards, including guidance on genetic workup as a key tool in a large proportion of such cases. Improved reporting standards, including the systematic documentation of diagnostic tests performed, are essential to avoid the negative therapeutic consequences of misdiagnoses, address the diagnostic gap in CKDx, and inform future research. By fostering a cause-directed approach, this work aims to enhance patient care and lay the foundation for further advancements in nephrology
Synthesis and Reactivity of a Diiron Complex Related to the Active Site of the [FeFe]-Hydrogenases: Towards a Stabilized Terminal Hydride
No full textInternational audienceIn a context of energy crisis, hydrogen (H2) is increasingly seen as a green energy vector. However, its production still largely depends on fossil fuels. In nature, metalloenzymes, particularly [FeFe]-hydrogenases, efficiently catalyze the reversible conversion of H2 into protons as described by the equation: H2 = 2H+ + 2e-.[1] This reaction takes place under mild conditions (room temperature and atmospheric pressure) without requiring noble metals, making it a promising route for sustainable H2 production.To develop efficient catalysts based on earth-abundant metals, bioinspired complexes related to the active site of [FeFe]-hydrogenase are currently researched.[1,2] Notably, organometallic diiron dithiolate complexes have been developed with phosphine ligands, to construct novel electrocatalysts for the hydrogen evolution reaction. In this context, a complex containing two electron-rich chelating phosphine ligands [Fe2(µ-pdt)(2-dmpe)2(CO)2] (pdt: propanedithiolate, dmpe: bis(dimethylphosphino)ethane) has been synthesized and structurally characterized. In solution, this complex is present under two isomers (Scheme 1), one of them displays a rotated geometry such as the active-site of the [FeFe]-hydrogenases. Very reactive, the compound [Fe2(µ-pdt)(2-dmpe)2(CO)2] activates small chlorinated molecules forming regioselectively novel terminal or bridging chloro complexes from CHCl3 or CH2Cl2, respectively.[3] In addition, regioselective formation of protonated complexes is also observed. The addition of a strong acid mainly affords a bridging hydride complex, while the use of a lower acid leads to a particularly stabilized terminal hydride isomer.[4
Shifting the remote sensing paradigm for monitoring the critical zone using drones
No full textInternational audienceRemote sensing data are increasingly used to monitor the critical zone. This study argues that drones are transforming the remote sensing paradigm. While recent satellite constellations (e.g., Sentinel-1 and Sentinel-2) have revolutionized Earth observation through improved temporal resolution, most research efforts have focused on refining data processing methods to extract key environmental variables such as soil moisture (Gao et al. 2017), snow cover ( Gascoin et al. 2019), and crop classification (Blickensdörfer et al. 2022).In parallel, drone technology has become more prevalent. Their high flexibility and superior spatial, spectral, and temporal resolutions enable the acquisition of high-quality remote sensing data over limited areas. To monitor essential critical zone and biodiversity variables effectively, it is crucial to adapt acquisition protocols. These protocols must be defined through interdisciplinary collaboration, considering the processes under study before data collection. They should determine the optimal spectral and temporal resolutions based on the size of the target object (e.g., leaves, trees, landscapes), its characteristics, and the ecological, hydrological, or climatic processes influencing its behavior over time (e.g., hourly, daily, or seasonally).Drones show great potential for applications such as viticulture, forest ecology, and habitat mapping, though their use remains exploratory and experimental.This paper presents three case studies demonstrating the capabilities of drones in critical zone monitoring and their role in shifting the remote sensing paradig
Désinformation et observance thérapeutique en oncologie : deux études expérimentales par vignette en population générale
No full textInternational audienceContexte : L’impact de la désinformation en oncologie reste peu étudié (Swire-Thompson & Johnson, 2024). Des études corrélationnelles en population générale ont montré un lien entre croyances conspirationniste (CCs) et intention de recourir à des médecines alternatives (MA) en replacement des traitements conventionnels (Fournier & Varet, 2024). La présente recherche visait à tester la causalité de ces relations et identifier des leviers interventionnels.Méthodes : Deux études expérimentales en ligne (N = 258 et 462) préenregistrées (https://doi.org/10.17605/OSF.IO/2EDT9) manipulaient l’exposition à un contenu de désinformation relayant des CCs sur les traitements oncologiques et évaluaient sa crédibilité. Les participants sans antécédents de cancer se projetaient dans la position d'un patient recevant un diagnostic de cancer avec recommandation de chimiothérapie.Résultats : Etude 1 : l'exposition à un contenu pro-CCs (vs. anti-CCs) augmentait les intentions de recours à des MA en remplacement de la chimiothérapie, via un effet sur les CCs, uniquement chez les participants jugeant le contenu très crédible (effet indirect à +1 E.T. : d = 1.25, IC95% [0.95, 1.58]). Etude 2 : lorsque l’exposition à l’article pro-CCs était précédée d’une induction (vs. non-induction) à la vigilance et l’exactitude, l’intention de recourir aux MA en remplacement était réduite (effets indirects agrégés via la crédibilité et les CCs : d = -0.30, IC95% [-0.49, 0.11]).Discussion : Ces résultats corroborent l'existence d’effets délétères de la désinformation sur les comportements de santé en oncologie. Les implications et limites pour les réduire en population générale (e.g., dépistage) et clinique (e.g., adhésion thérapeutique) seront discutés
« La politique vaccinale durant la Covid 19 : une oscillation inassumée entre responsabilité individuelle et responsabilité collective »
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Thermodynamics and kinetics of the isotopic equilibration of nitrogen gas ( N 2 ) in water: Implications for biological N 2 fixation experiments
No full textInternational audienceBetter characterization of biological N 2 fixation along with its controlling factors is needed for improved projections of the feedbacks between nitrogen cycling, ecosystems productivity, and climate dynamics. Building on an ongoing community effort to refine estimates of biological N 2 fixation, we outline several considerations aimed at improving 15 N 2 incubation measurements. We first show based on a theoretical analysis that the bias associated with equilibrium isotopic fractionation is within the uncertainty of 15 N 2 incubation experiments, even under conditions with a large headspace to aqueous ratio, such as in soil or sediment incubations. Second, we empirically determine the effects of temperature and agitation on the equilibration kinetics. Shaking intensity seems to be a dominant control on the kinetics of equilibration. Our results show that nearly complete equilibration of dissolved 15 N 2 is achieved within 4 min of vigorous shaking at 20°C at atmospheric pressure, but significantly slower at lower temperatures. The equations presented in our study are adaptable to varying 15 N 2 incubation conditions and other trace gas isotope addition experiments
Mobilités nocturnes et VELIs : enjeux et limites d’un usage urbain émergentProjet VIMob, Expérimentation des usages de véhicules intermédiaires et véhicules électriques légers
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Femmes et direction d'entreprise : regards croisés franco-allemand sur les réformes récentes
No full textInternational audienceL'actualité législative européenne, en particulier la directive européenne 2022/2381 "Women on Boards", est l'occasion la revenir sur les réformes menées en France et en Allemagne pour promouvoir la parité au sein des organes de gouvernance des entreprises. Les réformes successives adoptées par les deux pays, notamment l'instauration de quotas, leur ont permis d'être pionniers en la matière. Cette conférence est l'occasion de dresser un état des lieux comparé et d'observer comment le législateur, en droit des sociétés, saisit la question de l’égalité de genre
Joint Sub-6 GHz and mm-Wave V2I MIMO Radio Channel Characterization
No full textInternational audienceThe development of 5G and 6G networks has driven to the development of two key technologies: massive Multiple-Input Multiple-Output (mMIMO) and access to millimeter wave (mm-Wave) frequencies [1], and the concept of distributed cell-free massive MIMO (CF-mMIMO), primarily targeting sub-6GHz frequencies [2], [3]. In this context, the demand for very high-speed systems is growing rapidly, especially for scenarios with a high density of users. In particular, the transmission of navigation, safety and multimedia entertainment data in vehicles is a major challenge, requiring a communication scheme with very high throughput, low latency and very high coverage quality. To meet these objectives, CF-mMIMO technology is a promising candidate: distributed antennas provide seamless coverage and their synchronization reduces latency, while guaranteeing high throughput. The spectrum for these systems is generally in the sub-6 GHz range (FR1), where moderate attenuation ensures a favorable link budget. In order to increase capacity, wider frequency bands are also being investigated in other parts of the radio spectrum, for example in the millimetre-wave range (FR2) where bandwidths of up to 100 MHz are available in the 26–28 GHz and 40 GHz bands.The coexistence of these technologies would require a fine exploitation of radio channel characteristics considering vehicle and user mobility for Vehicule-to- Infrastructure (V2I) and Vehicle-to-Vehicle (V2V) applications. At mm-Wave frequencies, most current mm- Wave V2X measurements are conducted in static environments rather than dynamic ones, and primarily focus on propagation losses [4]. The limited number of mm- Wave V2V channel measurements makes it difficult to draw statistically significant conclusions about real-world mm-Wave V2V channels. In [5], [6] dynamic V2V SISO channel measurements were performed to investigate the large-scale parameters and stationarity. Channel sounder and first measurements for CF-mMIMO have been presented in [7], [8]. More recently investigations on large-scale parameters have been presented in [9]. V2V measurements at 3 GHz and 30 GHz in urban scenarios have been described in [10].In this article, we present a dual-band channel measurement campaign for the V2I scenario, in which the sub-6GHz and mm-Wave frequency ranges are jointly sounded. More specifically, the multipath channel is evaluated simultaneously at 5.93 GHz and 26.5 GHz using two complementary real-time MIMO sounders. The experimental setup is provided in Section II. The measurement campaign is described in Section III. Data processing is detailed in Section IV, and the results in terms of Power Delay Profile (PDP), Doppler Spectral Density (DSD) and path loss are illustrated in Section V