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From research to Deuxfleurs and back again: towards digital service infrastructure as commons
No full textInternational audienceWe introduce Deuxfleurs -- a hosting collective in France -- and summarize its relation to research; we then propose a preliminary analysis of Deuxfleurs' digital service infrastructure as a Common Pool Resource (CPR). Digital service infrastructure are well-studied in Computer Science from a technical point of view, but their governance is often a blind spot. Conversely, digital commons is an active field of research, but proposed results often ignore the materiality of the infrastructure. Combining the two aspects fits the definition of "undone" Computer Science and can open interesting research questions
SPATIALLY FILTERED SPARSE BAYESIAN LEARNING FOR DIRECTION-OF-ARRIVAL ESTIMATION WITH LEAKY-WAVE ANTENNAS
No full textInternational audienceDirection-of-arrival (DoA) estimation with leaky-wave antennas (LWAs) offers a compact and cost-effective alternative to conventional antenna arrays but remains challenging in the presence of coherent sources. To address this issue, we propose a spatially filtered sparse Bayesian learning (SF-SBL) framework. Firstly, the field of view (FoV) is divided into angular sectors according to the frequency beam-scanning property of LWAs, and Bayesian inverse problems are then solved within each sector to improve efficiency and reduce computational cost. Both on-grid SBL and off-grid SBL formulations are developed. Simulation results show that the proposed approach achieves robust and accurate DoA estimation, even with coherent sources
Co-culturing with bacteria modulates fatty acid composition in benthic diatom biofilms for lipid-based biotechnologies: A case study of Amphora sp.
No full textInternational audienceDespite being recognized as promising oleaginous microalgal resources, benthic diatom biofilms remain overlooked in microalgal biotechnology. To enhance their industrial potential, bacterial interactions can exploit to boost biomass, increase lipid yields and tailor lipid profiles. Given the complexity of natural biofilms, our study adopted a reductionist approach to investigate the impact of bacteria on the metabolism of a marine benthic diatom, Amphora sp., through binary co-cultures. Bacteria were isolated from non-axenic Amphora sp. biofilm cultures during the exponential phase in a lab-scale porous substrate biofilm photobioreactor. A bacterial biofilm assay was conducted to select biofilm-forming strains, followed by co-culturing them with Amphora sp. in bottle culture flasks, assuming these strains would persist and interact within the Amphora biofilm. All cultures were maintained for 6 days in F/2-enriched artificial seawater at 16 • C, under a 12:12 light:dark cycle (100 μmol photons.m -2 .s -1 ). Biomass and lipid contents were quantified using the gravimetric method, while fatty acid profiles were analysed using GC-MS. Results showed that some bacterial strains reduced Amphora sp. biomass, while Nitratireductor sp. and Sulfitobacter sp. had no noticeable effect. However, significant shifts in fatty acid profile of Amphora sp. were observed in most co-cultures while none of the individual bacterial strains substantially affected lipid production compared to its axenic and non-axenic counterparts. Co-cultures with Nitratireductor sp. and Sulfitobacter sp. yielded 50-55 % saturated, 40-50 % monounsaturated, and 1-6 % polyunsaturated fatty acids, indicating favourable biodiesel properties. Thus, modifying the microbiome of microalgal biofilms could be an innovative strategy for tailoring fatty acid composition for lipid-based applications
Procédé de pilotage d'un réacteur nucléaire, réacteur nucléaire et procédé de calibration
No full textActes de Collogue EACT : L'Histoire de la naissance de la sinologie française : la contribution des missionnaires et les savants français au XVIIIe siècle
No full textActes de Colloque : The 5th International Symposium of the European Association of Chinese Teaching in celebration of the 10th Anniversary of the EAC
Tara Polaris expeditions: seasonal and long-term contaminant monitoring in the changing central Arctic
No full textInternational audienceThe central Arctic atmosphere, cryosphere, hydrosphere and biosphere, is heavily impacted by anthropogenic activities. While some contaminants originate from local activities, the majority are transported over long distances via rivers, ocean currents, and atmospheric pathways. Contaminants can have adverse effects on the environment, ecosystems, and human health, which are expected to intensify with continued emissions and warming climate. This article outlines the objectives for new studies on contaminants in the Arctic Ocean, in particular during the Tara Polaris expedition, with an emphasis on year-round long-term contaminant dynamics and associated ecotoxicological risks. Mercury contamination remains a major concern in the Arctic, especially in the form of methylmercury, which is primarily produced by marine microbes. Methylmercury bioconcentrates, bioaccumulates and biomagnifies to harmful levels in Arctic wildlife and threatens indigenous communities. Anthropogenic lead (Pb), though low in Arctic waters, remains toxic and may be remobilized by climate change. Plastic pollution, from nano-to macro-scales, is widespread across all Arctic compartments, closely interacting with planktonic communities and posing ingestion risks to invertebrates, fish, seabirds and mammals (including humans). Chemicals of Emerging Arctic Concern (CEAC), including newly recognized persistent organic pollutants inherited from past industrial activities (e.g., per-and polyfluoroalkyl substances (PFAS)), are more recalcitrant in the environment than many other synthetic compounds, raising serious questions about their long-term ecological and health effects. In this context, the Tara Polaris expeditions aim to produce high-resolution, year-round observational data in the central Arctic to deepen our understanding of contaminant sources, transport, internal cycling and environmental fate. These data will also support the development and refinement of numerical models for contaminant dynamics in the context of both Arctic and global environmental change
Dose- and genotype-dependent cardiac arrhythmia and sudden death in rats following microdystrophin gene therapy
No full textInternational audienceRecombinant adeno-associated virus (rAAV) vectors encoding microdystrophin (MD) are a promising treatment for Duchenne muscular dystrophy (DMD). GNT0004, an rAAV2/8 vector expressing MD1, is currently being tested in patients with DMD. Here, we explored supra-optimal intravenous doses of GNT0004 (2.1 × 1014 and 4.2 × 1014 vg/kg, up to 14 times the therapeutic dose) in wild-type (WT) and DMDmdx rats. In all cohorts, robust MD1 protein expression was observed. In DMD animals, creatine kinase levels were normalized, and skeletal muscle and heart histology and functions were improved. However, unexpected sudden deaths occurred at the highest dose. In WT animals, deaths were observed at both doses and were associated with increased arrhythmic events, which may promote structural and functional heart issues. Immunohistological analysis suggested that overexpression of MD1 may disrupt the dystrophin-associated protein complex, increasing the risk of arrhythmias and sudden death. In DMDmdx rats, the 2.1 × 1014 vg/kg dose was well tolerated, but some deaths occurred at 4.2 × 1014 vg/kg, for which a causal link to GNT0004 cannot be excluded. At this dose, increased arrhythmic risk and cardiac pathological remodeling were observed. These observations highlight the potential risk of MD overexpression in the heart and suggest a need for careful monitoring of patients with DMD treated with gene therapy
Symposium : Enquête, compétences critiques et enseignement de l’histoire
No full textInternational audienc