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Multidisciplinary science funding is more than ever a planetary priority: Reflections from the Make Our Planet Great Again (MOPGA) program
No full textInternational audienceGlobal change poses “wicked problems” that have become ever more complex, pervasive, and damaging. Developing innovative solutions increasingly require diverse research approaches. The Franco-German Make Our Planet Great Again (MOPGA) program was designed to create a unique international network of top-level research, from fundamental to solution-oriented projects. MOPGA stands out from other large research initiatives by focusing not on a singular central research challenge but on facilitating multidisciplinary interactions between traditionally separated fields. MOPGA recognized that social, natural and engineering sciences share a unifying aim to address global change. In addition to addressing timely and innovative research questions within disciplines, MOPGA worked to improve communication across disciplines via annual meetings for all laureates and their research groups, scientific board exchanges, and public online seminars. Drawing on our MOPGA experiences, we discuss how such exchanges should be extended to meet the needs identified by the scientific community, international policy-makers, and regional stakeholders. In the current political landscape of scientific suppression and heightened mistrust in scientific expertise, the need for such bold, independent and collaborative scientific initiatives is greater than ever
Bumblebees are the most efficient pollinators of raspberry and strawberry in urban environments
No full textInternational audiencePollinators are essential for crop pollination, but pollinators differ in their pollination efficiency. In urban areas, environmental filters such as soil sealing or the urban heat island lead to biotic homogenisation of pollinator communities, with generalist species being favoured while specialist species are filtered out. Therefore, efficient pollinators may be excluded from urban areas. In the context of the development of urban agriculture, urban areas require pollination by efficient pollinators. Here, we ask whether pollinators sustained in urban environments are equally efficient, and whether urbanisation impacts the efficiency of pollinators delivering pollination services.Using strawberry and raspberry as experimental plants, we carried out single visit experiments over 2 years (2023 and 2024) in spring and autumn, to assess pollination efficiency in densely urbanised and suburban sites in the region of Paris (France). We measured fruit mass, malformation and seed set of fruits which developed from flowers having received a single visit from a pollinator.3. We found that bumblebees were more efficient than honeybees as pollinators of raspberry, but not strawberry, as measured by fruit mass.Bumblebees were also more efficient than small and large solitary bees for pollinating strawberry, and more efficient than large solitary bees for pollinating raspberry. These differences were detected on mass for strawberries, and on mass, seed set and fruit malformation for raspberries.Practical implication: Environmental filters in urban environments tend to favour few generalist pollinator species. On one hand, these environments support honeybees, which we found were not necessarily the most efficient. On the other hand, wild pollinators, in particular bumblebees, were more efficient than honeybees for pollination of strawberry and raspberry. Thus, urban conservation strategies should focus on promoting these wild and efficient pollinators by planting beneficial plant species in flower beds and providing nesting habitats for ground nesting pollinators. This would promote diverse and efficient pollinators and thus enhance pollination services for urban agriculture
Invasive aspergillosis in liver transplant recipients in France (2007–21): a nationwide, retrospective, matched case–control study
No full textInternational audienceBackgroundInvasive aspergillosis is a rare but severe complication of liver transplantation. Incidence varies from 1·2% to 5·6% and mortality is greater than 50%. Few studies have investigated this complication. We aimed to describe cases of, and identify the factors associated with, invasive aspergillosis occurrence and mortality.MethodsThis nationwide, retrospective, matched case–control study included cases of invasive aspergillosis occurring after liver transplantation between Jan 1, 2007, and Dec 31, 2021, matched 1:1 on centre and transplantation period to control individuals without invasive aspergillosis across 15 liver transplantation centres in France. Cases were patients aged 18 years or older who presented with proven or probable invasive aspergillosis. The matched control was the next patient who received a transplant at the same transplantation centre after the case. Cases were retrospectively identified in each centre using the mycology laboratory database and the French Medicalised Information System Programme. Data were retrieved from hospital charts. The primary outcome was the identification of risk factors associated with the development of invasive aspergillosis following liver transplantation. Multivariable analysis using conditional logistic regression with a random effect for study centres was done to establish risk factors.FindingsAmong 14 332 liver transplantations, 196 recipients with invasive aspergillosis (62 [32%] female and 134 [68%] male) were identified and matched with 196 control individuals (54 [28%] female and 142 [73%] male). Invasive aspergillosis occurred at a median of 29 days (IQR 7–173) after liver transplantation. Risk factors for developing invasive aspergillosis were history of chronic kidney disease (adjusted odds ratio 4·13 [95% CI 2·35–7·24]), liver transplantation for acute liver disease (3·41 [1·44–8·06]), post-liver transplantation renal replacement therapy (3·82 [1·96–7·42]), and post-liver transplantation vasopressor support for longer than 24 h (2·82 [1·70–4·68]).InterpretationThis study identifies three patient populations at risk of invasive aspergillosis after liver transplantation: patients with history of chronic kidney disease, those who have received a transplant for acute liver disease, and those who had a post-operative period marked by organ failure. This identification could lead to new invasive aspergillosis prophylactic strategies
Estimating characteristic lengths by combining direct measurements and the Kozeny-Carman relation
No full texthttps://doi.org/10.1121/10.0042709This work revisits an indirect characterization method that exploits visco-inertial and thermal frequency response functions to estimate the macroscopic parameters of fibrous media [Panneton and Olny, J. Acoust. Soc. Am. 119, 2027–2040 (2006); Olny and Panneton, J. Acoust. Soc. Am. 123, 814–824 (2008)]. In practice, this method faces major challenges for highly resistive materials because the transition frequencies fall outside the measurable range of the standing-wave tube. To overcome this limitation, an alternative approach combining the equivalent characteristic-length relation derived from ultrasound measurements with a Kozeny–Carman-type relation is proposed. The methodology and its validation on resistive felts demonstrate improved estimation of viscous and thermal characteristic lengths from measurable parameters
L’air dans les infections respiratoires : controverses et enjeux pour le soin
No full textNational audienc
La fiscalité locale sur le foncier et le logement : quels enjeux autour de la production de logements abordables ?
No full textIsospectrality for infinite-type hyperbolic surfaces with discrete length spectrum
No full textWe prove that every family of isospectral surfaces with discrete length spectrum arising from Sunada's method is finite. Furthermore, by introducing the topological notion of surfaces with self-duplicating ends, we show that every finite group can be realized as the full isometry group of a hyperbolic structure with discrete spectrum on such a surface, if the genus is infinite. Under the same topological assumptions, we also demonstrate that the above-mentioned isospectral families can have unbounded cardinality within a fixed moduli space
Efficacité et équité de l’enseignement de l’algèbre après une formation continue en didactique au collège
No full textInternational audienceHaving observed recurring difficulties in the learning of elementary algebra, teachers decided to collaborate with researchers to develop tools for analysing students’ work and to design a new teaching method based on the analyses carried out. The method was tested and evaluated in terms of effectiveness and fairness, and the positive results convinced the teachers to extend the experiment. Scientifically, this research addresses a double problem: documenting teachers’ appropriation and use of mathematics education knowledge, and questioning the concepts of effectiveness and fairness for a quantitative approach to the effects of teaching.Le constat de difficultés récurrentes d’apprentissage de l’algèbre élémentaire a conduit des professeurs à s’engager auprès de chercheurs dans un dispositif collaboratif en vue de développer des outils d’analyse des productions des élèves, et de concevoir un dispositif d’enseignement nouveau qui réponde aux analyses effectuées. Ce dispositif a été expérimenté et évalué en termes d’efficacité et d’équité ; les résultats positifs ont convaincu les enseignants de prolonger l’expérimentation. Du point de vue scientifique, cette recherche répond à une double problématique : documenter l’appropriation et l’utilisation de savoirs didactiques par des enseignants, interroger les concepts d’efficacité et d’équité pour une approche quantitative des effets de l’enseignement
Crystallography-dependent MgH2 desorption mechanisms revealed by in-situ SEM with Ti3AlC2 MAX phase catalysts
No full textIn this work, in-situ scanning electron microscopy combined with crystallographic analysis is used to directly visualise, for the first time, the destabilization of MgH2, under a localised electron beam in a Mg-based composite containing a Ti3AlC2 MAX phase. H desorption is shown to initiate and propagate along nanometric linear defects aligned with the {1 10} planes of the rutile MgH2 lattice, the planes with the highest Mg atomic density. This orientation-selective transformation to Mg, accompanied by a volume shrinkage, releases residual stress fields by producing cracks within Mg and at MgH2/Mg interfaces. The presence of Ti3AlC2 particles further localises or promotes the transformation at the interface between Ti3AlC2 and Mg. Such interphases act as favorable sites, analogous to grain boundaries, where the MgH2→Mg + H2 transformation preferentially occurs. These findings provide direct experimental evidence of crystallography-dependent desorption channels and point toward microstructural features that may be exploited to accelerate H release kinetics in Mg-based hydrides
Catégories et approches Dynamiques des Systèmes de Marché : le cas de la Haute Couture
No full textInternational audienceSi les catégories constituent des rouages essentiels dans l’évolution des marchés (Blanchet, 2027), leur rôle demeure cependant peu explicité dans l’approche dynamique des systèmes de marché (Market System Dynamics, notée MSD ci-après) (Giesler, 2008 ; Giesler et Fischer, 2017). Dans cette recherche, nous nous intéressons au maintien d’une catégorie au cours du temps et en particulier à la manière dont elle s’est transformée pour continuer à jouer un rôle majeur au sein du marché. Dans cette optique, nous présentons (1) la littérature sur les MSD et les catégories organisationelles, (2) notre contexte (la Haute Couture) et la collecte de données afférentes ; enfin (3) la synthèse des principaux résultats et les principaux éléments de discussions et apports théoriques