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Selective catalytic conversion of polyphenylene oxide waste into benzene and toluene for hydrogen storage via zeolite-controlled hydro-pyrolysis
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Segmentation and morphometry of intracranial internal carotid artery calcification in relation to brain atrophy
No full textNational audiencePurposeIntracranial internal carotid artery calcification (iICAC) is a form of intracranial arteriosclerosis and is associated with an elevated risk of stroke and dementia. However, iICAC’s relationship with brain atrophy remains poorly understood. We aimed to automatically quantify iICAC morphometric characteristics and evaluate their associations with regional brain volumes (BVs).MethodsWe developed an automated approach to compute iICAC surface area and thickness from CT brain scans in a sample of physically active South American subsistence farmers (n = 1,232, age range: 40 years to 92 years, 48.1% female, 794 Tsimane and 438 Moseten). Linear regression models were used to assess associations between two iICAC features and regional BVs, adjusted for age, sex, population, and total intracranial volume.ResultsSignificant negative relationships were found between regional BVs and iICAC surface area, but not iICAC thick-ness. Frontal, parietal, temporal, and subcortical BVs exhibited significant negative associations with iICAC surface area (standardized β range: -0.146 to -0.066, p ≤ 0.013), while the occipital BV did not (standardized βlef t = -0.035, p = 0.249; βright = 0.007, p = 0.810). Subcortical BVs demonstrated the strongest negative associations with iICAC surface area (standardized βlef t = -0.146, p < 0.001; βright = -0.139, p < 0.001).ConclusioniICAC surface area—assumed to reflect arterial stiffness—shows a stronger relationship with regional BV loss than iICAC thickness—assumed to indicate arterial stenosis. The findings suggest that brain regions primarily supplied by the anterior circulation are more vulnerable to iICAC-related atrophy. Subcortical BVs showed the strongest negative associations with iICAC surface area, with region-specific analyses identifying significant effects in the putamen, thalamus, hippocampus, amygdala, pallidum, and ventral diencephalon, suggesting heightened vulnerability of deep gray-matter structures to iICAC-related atrophy
Risk-taking behavior related to mercury contamination in a high Arctic seabird
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Wideband Radiometry From P to S Band for Monitoring Polar Regions
No full textInternational audienceThis article reviews existing and planned contributions of spaceborne microwave radiometry from P to S band to new measurements of key geophysical variables with a particular focus on the polar regions. It summarizes the current state of spaceborne microwave radiometry to measure ice sheet thermal states, sea ice thickness (SIT), salinity, and sea surface salinity (SSS). Then, this article discusses the potential of wideband radiometry, with continuous sampling in the range of 0.4-2 GHz, as a breakthrough for enhancing the estimation of geophysical variables such as SSS and the geothermal heat flux beneath the polar ice sheets, which are currently monitored primarily using L-band radiometry satellites. Furthermore, this article describes opportunities for new unique observations that cannot be achieved with the current constellation of satellite sensors. In addition, this article demonstrates the advantages of using low-frequency radiometry in sensing soil moisture and biomass from space due to the great sensing depth. This article concludes with a discussion of mission concepts highlighting the CryoRad mission, which has been selected as one of the four candidates for European Space Agency Earth Explorer 12 competition and is now conducting Phase 0 feasibility studies, envisions a 0.4–2-GHz dedicated spaceborne radiometer operated with circular polarization
Compréhension territoriale de la circularité du système agroalimentaire : flux énergétiques et azotés de deux régions d'élevage en Bretagne (France)
No full textInternational audienceContextRegions of intensive farming are often associated with large nutrient surpluses emitted from agri-food systems (AFS). Agricultural transitions require reaching a balance between the roles of livestock systems in producing high-quality protein and organic fertilizers, while mitigating pollutant emissions. However, effects of the relative percentages of ruminants and monogastric animals in regions with high livestock density on their food production and environmental impacts remain unexplored. While most research on nutrient flows in AFS focuses mainly on large scales (e.g. continents, countries), the territorial scale remains underexplored.ObjectiveThis study aimed to develop an integrated, down-scaled (NUTS 3) assessment framework to analyze nitrogen (N) and energy flows in two territories with differing compositions of ruminants and monogastric animals.MethodsUsing material flow analysis based on public data, we examined two neighboring territories in Brittany, France. We assessed their environmental impacts, N flows, and energy functioning.Results and conclusionsThe two territories imported 38% and 62% of N in feed, respectively, producing enough animal products to meet 9–13 times their local need for animal-based food. The results suggest that the area of external agricultural land required for producing feed imports is as large as the used agricultural area in the territory. Energy from biogas production represented 20% of the total energy input of the AFS. The territory with a more balanced share of ruminants and monogastric animals had higher livestock N conversion efficiency (37% vs. 30%) but lower total N self-sufficiency (21% vs. 12%) than the more ruminant-dominant territory.SignificanceThese results provide novel insights into environmental impacts of multiple combinations of ruminant and monogastric animal systems in similar territories. Such results could be useful for local policymakers and AFS stakeholders to help them understand the impacts of different livestock combinations on N and energy flows in their territory. The study also provides a framework for subnational-scale assessments, which are not well represented in public data. This framework is a key first step to facilitate the transition toward more sustainable AFS
Density dependence modulates climate change impacts on eastern Bering Sea snow crab
No full textInternational audiencePopulations change as a result of many interacting processes, each of which may be moderated by density dependence and/or climate. Models and projections of population dynamics support conservation and economic planning, but the extent to which the influence of climate or density is incorporated varies.We develop a population dynamics model for eastern Bering Sea snow crab (Chionoecetes opilio) that fits to data collected from 1982 to 2023 to estimate variability in recruitment and mortality. We then use generalized additive models (GAMs) to explain the variability in recruitment, mortality and maturity using environmental covariates and density. Finally, we project the population forward under various assumptions about climate and density dependence on recruitment, mortality and maturity.Feedbacks among population processes result in different short- and long-term population trajectories. For example, including density dependence in mortality projections allows for a stronger rebound in the population in the short term, but the harmful effects of warming outweigh the protective effect of lower density in the long term.Projected long-term crab abundances were much lower than historically observed under receding ice cover in the Bering Sea regardless of the combination of processes driven by density and climate.Synthesis and applications. Our results underscore the need for management capable of addressing the impacts of both density and climate effects on multiple processes in harvested populations. Non-stationarity in drivers of population dynamics (e.g. climate change) will further affect the ability of management to achieve sustainable yields. Current frameworks built around equilibrium-based maximum sustainable yield are not well-suited to address either of these issues
Le Capital d'une capitale
No full textInternational audienceA travers l'exemple de Paris, ce livre propose une lecture renouvelée de l'histoire de la richesse. Grâce à une documentation exceptionnelle, l'analyse de l'évolution de la richesse parisienne au cours des deux derniers siècles permet en effet d'éclairer des processus rarement identifiables ailleurs. Dans la capitale, autant l'importance et la composition de la richesse varient, autant sa distribution reste stable. Les données individuelles portant sur l'ensemble de la population montrent que la richesse et ceux qui la détiennent connaissent un renouvellement continu, y compris au sein des plus riches, alors même qu'une part toujours considérable de la richesse est héritée. Si les Parisiens sont nombreux à épargner, leurs efforts sont épuisés par les incertitudes de la vie de sorte que, jusque dans les années 1920, deux tiers d'entre eux n'ont aucune richesse au décès. Il faut attendre la diffusion des systèmes de retraite pour que cette proportion diminue. Seule l'intervention publique permet alors de réduire la part très élevée des personnes qui meurent sans richesse ainsi que les écarts d'espérance de vie, de santé et d'éducation. Ces dimensions essentielles, longtemps presque figées en dépit de la longue croissance de la richesse jusqu'à la Première Guerre mondiale, n'ont sensiblement progressé qu'ensuite, notamment lorsque l'Etat social a transformé les conditions d'accumulation et de transmission du capital. L'histoire de la richesse ouvre ainsi sur une histoire des choix politiques, des aspirations sociales et des inégalités que les sociétés acceptent - ou refusent - de tolérer
Évaluation du programme Passerelle Plus: impact sur l’insécurité alimentaire de ménages en précarité et conditions d’efficacité d’un transfert monétaire non restrictif et accompagné
No full textInternational audienceContexte : En France, de fortes inégalités sociales persistent en matière d’alimentation. L’aide alimentaire ne répond que partiellement aux besoins et ne peut à elle seule enrayer les causes profondes de l’insécurité alimentaire (IA). Cette étude a pour objectif d’évaluer et comprendre l’impact du dispositif Passerelle Plus qui vise à réduire l’IA en proposant un transfert monétaire (TM) non restrictif et accompagné à des ménages en précarité. Méthode : Un essai contrôlé randomisé a été mené auprès de 342 ménages en précarité à Montreuil, identifiés par des acteurs sociaux de proximité puis répartis en 2 groupes : intervention (TM de 60 €/mois/personne du foyer pendant 4 mois via une carte utilisable pour paiement et retrait ; proposition de rendez-vous avec un travailleur social et d’un atelier d’échange sur l’alimentation) et contrôle (programme reçu après 6 mois). Les indicateurs d’IA, de bien-être et de lien social ont été mesurés par questionnaire à l’inclusion (T0), puis à 3 et 6 mois. Les achats alimentaires mensuels ont été recueillis à 3 mois pour évaluer la qualité nutritionnelle. Des entretiens qualitatifs ont été menés avec 20 participants et 28 acteurs de la mise en œuvre. Les coûts ont été recensés pour estimer le cout-efficacité du programme.Résultats : Le programme a significativement amélioré la sécurité alimentaire, le bien-être mental et le lien social à 3 mois. Les entretiens ont mis en évidence plusieurs leviers (soulagement financier et psychologique, confiance accordée aux usagers et aux acteurs locaux pour le ciblage) mais aussi des freins (saturation des services sociaux, durée limitée du soutien) à l’efficacité du programme. Conclusion : Passerelle Plus montre qu’une aide financière libre d’utilisation, associée à un accompagnement, réduit l’IA et renforce l’accès aux droits. Ces résultats apportent des éléments pour orienter les politiques publiques de lutte contre la précarité alimentaire et les inégalités sociales de santé en France MESSAGES PRINCIPAUX : Le programme Passerelle Plus combine transfert monétaire non restrictif et accompagnement. L’évaluation montre qu’il améliore la sécurité alimentaire et le bien-être des ménages en précarité, et identifie les facteurs qui influencent son efficacit
Genetic traits of IncK2 plasmids and the Escherichia coli host underlying the association to the chicken gut
No full textInternational audienceThis manuscript presents the phylogeny and conservation of IncK2 plasmids in Europe. It also provides insights into genetic traits responsible for IncK2 plasmids and its Escherichia coli host adaptation to the chicken gut. Fifty-eight E. coli isolates from nine European countries were sequenced using Illumina and Nanopore technology. Genetic analyses were performed to determine the relatedness of IncK2 plasmids and their E. coli hosts from poultry (80% of the total) and other sources. To analyse genetic traits associated with E. coli and IncK2 plasmid from chicken origin, a genome-wide association study (GWAS) was performed. The phylogenetic analysis of IncK2 plasmids revealed conservation across sources and countries of isolation. GWAS revealed multiple genes associated with IncK2 plasmids or its E. coli host from chicken origin. The predicted functions of these genes can indicate a selective advantage in the chicken gut, and that IncK2 plasmids are adapted to the physiological environment of the chicken gut. Impact StatementPlasmids are the main vector for the spread of antimicrobial resistance genes between bacteria and within different sources. This manuscript presents the analysis of the similarities of IncK2 plasmids carrying antimicrobial resistance genes across Europe. It also investigates genetic traits responsible for IncK2 plasmids and its Escherichia coli host adaptation to the chicken gut. Researching the ways how plasmids that carry antimicrobial resistance determinants adapt to their hosts and environments provides invaluable information for future interventions, aiming to limit the spread of these mobile genetic elements and antimicrobial resistance.</div
Potentiel des satellites Pléiades Neo pour restituer la topographie fine des glaciers
No full textInternational audienceLa résolution de 30 cm offerte par les satellites Pléiades Neo représente un gain d’un facteur deux par rapport à leurs prédécesseurs, les Pléiades HR. Combinée avec des capacités stéréoscopiques, elle permet de construire des modèles numériques de terrain (MNTs) métriques pour caractériser finement les reliefs, en particulier pour les petits glaciers, comme ceux des Pyrénées. Dans cette étude, nous évaluons la précision des MNTs déduits d’images Pléiades Neo sur les glaciers de l’Aneto, d’Ossoue et du Monte Perdido en les comparant à des MNTs acquis par drone et aux couvertures Lidar nationales. Nous montrons que les MNTs déduits avec le corrélateur More Global Matching (MGM) sont plus précis que d’autres corrélateurs. Nous soulignons également la capacité des MNTs Pléiades Neo à restituer des détails fins de la morphologie glaciaire comme les moulins sur le glacier d’Ossoue, beaucoup plus difficiles à caractériser avec Pléiades HR