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Integrating Transport Dynamics into the TIMES-Reunion Model: Exploring Energy Transition Pathways Toward Self-Sufficiency and Carbon Neutrality
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Oxygen supersaturation has negligible effects on warming tolerance across diverse aquatic ectotherms
No full textInternational audienceUnder the midday sun, when photosynthesizers are producing oxygen, shallow aquatic ecosystems can become supersaturated with oxygen (>100% air saturation) while they simultaneously peak in water temperature. It has been suggested that oxygen supersaturation could protect water-breathing animals from mortality during heatwaves because of the potential role of oxygen in governing thermal tolerance. Here, we conducted a circumglobal assessment of the effects of ecologically relevant oxygen supersaturation (150%, hyperoxia) on warming tolerance (here, measured using critical thermal maximum, CT max ) in 14 aquatic ectotherms from diverse marine and freshwater environments (10 fishes, four decapod crustaceans), in a series of 24 experiments that included 147 CT max trials and 1,451 animals using two warming rates (0.3°C min −1 and 1°C h −1 ). In 10 of 14 species, there was no effect of oxygen supersaturation relative to normoxic controls. In four species (two tropical reef fishes and two marine decapod crustaceans), we found mixed evidence for effects of oxygen saturation, with most of the effects being small ( ca . 0.2°C–0.3°C). Thus, contrary to predictions, we conclude that oxygen supersaturation is unlikely to protect most water-breathers from heatwaves and therefore few species distribution models or climate risk assessments will benefit from incorporating oxygen supersaturation
Assessment of Potential Microbial Hydrogen Consumption in European Hydrogen Underground Storage Sites
No full textInternational audienceUnderground hydrogen (H2) storage is a key technology for stabilizing Europe’s renewable energy supply, but microbial activity in subsurface environments may lead to H2 loss, gas quality degradation, and infrastructure damage. The CETP-funded HyLife project brings together four European microbiology laboratories and multiple industry partners to quantify microbial risks associated with underground hydrogen storage. Twenty-one brine samples from salt caverns, aquifers, and depleted gas reservoirs across ten countries were characterized so far using developed fully standardized anoxic sampling and analytical workflows, including geochemical analysis, enrichment cultures, qPCR, and 16S rRNA sequencing. Distinct microbial communities were identified at each site, even when brine chemistries were similar. Enrichment experiments revealed rapid H₂ loss within weeks in several porous-rock reservoirs at ≤ 50°C, while most salt-cavern brines showed negligible activity after 12 months. Hydrogen consumption was most commonly linked to methanogenesis. Kinetic parameters derived from these tests are being integrated into 3D reactive-transport models and an open-access database to support techno-economic assessments, mitigation strategies, and evidence-based guidelines for selecting safe and efficient hydrogen storage sites. The project actively engages industry partners and continues to expand its dataset through additional sampling across diverse geological settings
Casimir operators for the relativistic quantum phase space symmetry group
No full textInternational audience13 page
Wave Friction Factor and Roughness Definition in Multi‐Scale Coral Barrier Reef
No full textInternational audienceWave frictional dissipation is a key process in rough seabed’s environments such as coral reefs, expected to significantly reduce incoming wave energy. In phase‐averaged models, wave dissipation is typically estimated through a wave friction factor which is dependent of the near‐bed orbital excursion and the hydraulic length, a proxy for the seabed substrate roughness. A field experiment was conducted in the South‐Western coral reef barrier of Mayotte (Indian Ocean) to compute through a frequency‐integrated wave energy balance. Significant time and space variations of have been observed, driven by the evolution of the wavefield and the diversity of coral geometry and scales found along the barrier. The fine reef architecture has been examined thanks to a high‐resolution multi‐beam echo sounder survey. This study has reassessed the established link between hydraulic roughness length and roughness standard deviation; it also indicates that second‐order roughness metrics may also significantly explain variations in . Future challenges remain in the proper definition of the length scales of seabed variability attributed to roughness and to bathymetry
Les variations du prix du riz dans la région Haute Matsiatra à Madagascar
No full textIn this article, we demonstrate that climate change has a strong impact on human activities. Based on descriptive analyses, we find that among the prices of substitute products, demand, and inflation, it is the climate that accounts for the largest share of rice price fluctuations in the Haute Matsiatra region. International tensions during the period considered have no significant influence on rice price variations in this region. These results call for caution in this context of significant climate changes.Dans cet article, nous démontrons que le changement climatique a un fort impact sur les activités humaines. En se basant sur des analyses descriptives, nous trouvons qu'entre les prix des produits de substituions, la demande et l'inflation, c'est le climat qui endosse la part importante dans les variations des prix du riz dans la région Haute Matsiatra. Les tensions internationales de la période considérée n'ont aucune influence significative dans les variations du prix du riz dans cette région. Ces résultats lancent un appel à la prudence dans ce contexte de forts changements climatiques.
Spécificités des petites économies insulaires et marchés du travail - Regards croisés entre la Polynésie française et La Réunion
No full textInternational audienceCet article constitue le "Grand entretien" du numéro de la RIMHE consacré aux "Stratégies et défis de la GRH dans les environnements singuliers". Philippe Jean-Pierre, Professeur de sciences économiques à l’Université de La Réunion, et Florent Venayre, Professeur de sciences économiques à l’Université de la Polynésie française, y abordent les caractéristiques et les difficultés propres aux marchés du travail ultramarins
Chicoric Acid and Chlorogenic Acid: Two Hydroxycinnamic Acids Modulate the Glucose 6-Phosphatase Activities in Pancreatic INS1 Beta-Cells—Novel Data in Favor of Two Putative Conformations of the G6Pase Within the ER Membrane
No full textInternational audienceChicoric and chlorogenic acids (CRA and CGA), two caffeic acid derivatives found in a large variety of plants, particularly in Asteraceae, are known to modulate glucose-6phosphatase (G6Pase) in hepatic and muscle cells. The aim of the present study is to use CRA/CGA to explore the modulation role and molecular mechanism of endocrine pancreatic beta-cells' insulin secretion. The G6Pase enzyme activity influenced by caffeic and derivatives alone or in combination was assessed on microsomal fractions of INS1-betacells and hepatocytes. Overall, our results show inverse effects of CGA/CRA, allowing us to investigate the G6Pase activity modulation under low and high glucose concentrations. Our data strongly suggests the existence of two putative forms of the G6Pase enzyme. Based on these observations, we formulate the hypothesis of an adaptative bi-conformational model of G6Pase enzyme activity modulation depending on the level of the beta-cell glucose exposure
Inflammatory Bowel Disease and Pharmacotherapeutic Treatment for Healthcare Providers: a Pedagogic Tutorial
No full textInternational audienceInflammatory bowel disease (IBD) represents significant health challenges on a global scale, primarily encompassing Crohn's disease and ulcerative colitis. These conditions are characterized by cycles of relapse and remission. Current treatment options, including conventional chemical therapies and biologics such as anti-Tumor Necrosis Factor α (anti-TNFα), anti-integrin, anti-interleukins 12 (IL-12) or 23 (IL-23) agents, Janus Kinase (JAK) inhibitors, and sphingosine-1-phosphate (S1p) receptor modulators, provide symptomatic relief but do not offer a cure. These therapies are associated with both localized and systemic adverse effects, necessitating careful patient monitoring. Probiotics and prebiotics have been investigated for their potential to enhance gut microbiota diversity, which may assist in managing IBD. However, their efficacy in preventing disease flares remains limited. Recent advances in drug delivery systems, including pressure-based and pH-sensitive formulations, aim at enhancing localized treatment efficacy while minimizing adverse effects. Additionally, a pharmacogenomic approach could improve treatment personalization, optimize therapeutic outcomes, and enhance patients' quality of life by addressing mental health needs and ensuring comprehensive follow-up care. Despite increased awareness and education among healthcare providers regarding IBD, there is still a need for clearer guidance on available treatment options. Objective: This review aims at providing deeper understanding of IBD management strategies, ultimately striving to improve the quality of care for individuals affected by this disease.</div
A new magnetic observatory in La Réunion Island – meeting data quality requirements in a volcanic island setting
No full textInternational audienceAbstract. A new magnetic observatory has been set on La Réunion Island in the Indian Ocean through a collaboration between the “Institut de physique du globe de Paris” (IPGP) local volcano observatory (Observatoire Volcanologique du Piton de la Fournaise – OVPF) and its magnetic observatory service. This observatory is isolated and serves to monitor the evolution of the Earth's magnetic field in that region. It is also particularly useful for large-scale modelling of the core field and other contributions to the geomagnetic field. Three-component vector magnetic field data are continuously collected at 1 Hz using a fluxgate, while scalar data are collected at 0.2 Hz with a proton magnetometer. The data are transmitted every 5 min to IPGP main site and made immediately available to the scientific community (see http://www.bcmt.fr, last access: 22 August 2025). Due to the strong magnetic field generated by the surrounding volcanic rocks, the differences between the magnetic field strengths as recorded by the proton magnetometer and the strengths calculated from the recorded vector field values vary by more than ∼2 nT during a day. To circumvent this difficulty, constant offset values of −2400, 280, and −20 nT are added to the X, Y, and Z magnetic field components respectively, prior to the data distribution. We show that this approach efficiently reduces the differences between measured and calculated magnetic field strengths inside a day. Calibrated observatory data have been calculated over the year 2023, and, although the baseline values present variations up to 70 nT throughout that year, the derived data meet the quality required for an intermagnet observatory. A Fourier analysis of the data shows that these are not contaminated by significant noise even if peaks at 0.2 Hz indicate small cross-talk between vector and scalar instruments