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Lien entre les limites rencontrées par le chercheur en éducation et la mise en place d’innovations
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Comment caractériser l'autonomie, la coopération, la créativité et l'équité sociale et de genre dans des séances d’enseignement orientées investigation en sciences ? Retour sur l’élaboration d’une grille pluridimensionnelle
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Comparative genomic analysis of QTL for resistance to Aphanomyces euteiches between pea, lentil, faba bean, and the model species Medicago truncatula
No full textInternational audienceKey message: QTL mapping and GWAS detected resistance QTL to Aphanomyces euteiches in faba bean, lentil, and Medicago truncatula. Weak genomic conservation between resistance QTL was identified between these legumes and pea.Abstract: QTL mapping and GWAS detected resistance QTL to Aphanomyces euteiches in faba bean, lentil, and Medicago truncatula. Weak genomic conservation between resistance QTL was identified between these legumes and pea. Aphanomyces root rot, caused by Aphanomyces euteiches, is a damaging disease affecting various legume species. Quantitative trait loci (QTL) for partial resistance have been mainly identified in pea, and to a lesser extent in lentil and Medicago truncatula. This study aimed to identify novel resistance loci from available lentil and faba bean populations, and examine genomic conservation of resistance QTL across legume host species. QTL mapping in the Pop2 faba bean recombinant inbred line (RIL) population and genome-wide association study (GWAS) in the AGILE lentil diversity panel were performed for resistance to A. euteiches under controlled conditions, using genotyping data previously reported. A previous QTL mapping in the LR3 M. truncatula RIL population was updated using 1,536 new SNPs (single-nucleotide polymorphisms). Synteny between resistance QTL to A. euteiches was analyzed based on gene orthology in QTL regions projected onto genomes, using the OrthoLegKB graph database. Four loci, including a major-effect QTL on chromosome 3, Ae-Vf3.1, were associated with resistance in faba bean. In lentil, six minor-effect GWAS-SNPs and two favorable haplotypes at Ae-Lc1.1 and Ae-Lc2.1 loci were identified. Updated analyses in M. truncatula narrowed to 8 Kb the interval of the major-effect locus AER1 and revealed three candidate genes. No synteny between major-effect QTL, detected in this study or previously reported in the literature, was identified across grain legume genomes. These results pave the way for translational genomics approaches facilitating resistance gene discovery and for resistance QTL deployment strategies in legume rotations to preserve their durability
Toxicity by contact of Bordeaux mixture but no behavioral responses of the egg parasitoid Trichogramma cordubensis
No full textInternational audienceThe increasing use of pesticides is recognized as a threat to pest natural enemies. We investigated the effects of Bordeaux mixture, a fungicide widely used in viticulture, on Trichogramma cordubensis, a biological control agent used against the major vineyard pest Lobesia botrana. The lethal and sublethal effects of 20 g.L -1 Bordeaux mixture on T. cordubensis were studied. To assess the potential persistence of Bordeaux mixture, each experiment was conducted at four different time scales after pesticide application. A first experiment aimed to assess the effects of surface contaminations to Bordeaux mixture on the longevity of T. cordubensis, which was reduced by 26 % when exposed to the fungicide. A second experiment aimed to assess the oviposition dynamics of T. cordubensis during the three first days after its emergence in contaminated or unexposed environments. No differences in oviposition were observed when T. cordubensis was exposed to Bordeaux mixture. A third experiment aimed to assess the oviposition choices of T. cordubensis between hosts on either contaminated or unexposed surfaces. No evidence of an oviposition deterrence was detected. Overall, surface contact with Bordeaux mixture was found harmless on T. cordubensis life parameters. Time after fungicide applications did not differently impact our results on longevity and behavior. However, time after both control and pesticide applications may have led to altered micro-environmental conditions affecting T. cordubensis' development. This study suggests that T. cordubensis inability to discriminate against a copper contaminated environment is a crucial factor in enhancing its effectiveness as a biological control agent
On the degree-two part of the associated graded of the lower central series of the Torelli group
No full textInternational audienceWe consider the associated graded of the lower central series of the Torelli group of a compact oriented surface. Its degree-one part is well-understood by D. Johnson's seminal works on the abelianization of the Torelli group. The knowledge of the degree-two part with rational coefficients arises from works of S. Morita on the Casson invariant and R. Hain on the Malcev completion of . Here, we prove that the abelian group is torsion-free, and we describe it as a lattice in a rational vector space. As an application, the group is computed, and it is shown to embed in the group of homology cylinders modulo the surgery relation of -equivalence
Rare interspecific hybridisation between sympatric African four-striped mice, and indications of fine-scale intraspecific spatial structure related to social factors
No full textInternational audienceSpatial and social population structures can influence intra- and interspecific genetic processes. We investigated the spatial and social genetic structure of two sister species and evaluated whether there was evidence of hybridisation between them at a microgeographic scale, in syntopy. Our study models were Rhabdomys bechuanae (Rbech) and Rhabdomys dilectus dilectus (Rdil). We generated population genetic data using microsatellite markers and cross-referenced some of these results with published behavioural data from a prior study, reanalysed here. We compared genetic diversity and gene flow both in sympatry and allopatry, we tested for hybridisation between the sister species in sympatry and assessed the relationship between kinship and fine-scale spatial and social organisation. Genetic diversity was high within all populations of the two species. Population genetic substructure was more pronounced in Rbech than in Rdil, consistent with stronger group cohesion reported for Rbech. STRUCTURE and NEWHYBRIDS analyses suggested that sympatric individuals, 5% in Rbech, and 2% in Rdil, might have hybrid ancestry. Our results indicate social fences may limit gene flow within and between species. Further, limited hybridisation suggests that, despite syntopy, only rare events of hybridisation may occur, possibly at phases of density troughs and/or that F1 hybrids have a relatively low fitness
Sanction de l'absence de revendication. Inopposabilité du droit de propriété à la procédure collective
No full textInternational audience(Com. 5 févr. 2025, no 23-19.029, F-D, Sté Liebherr Werk Biberach Gmbh et a. c / M.N et a., Gaz. Pal. 16 sept. 2025, p. 60, note V. Perruchot-Triboulet ; JCP E 2025. 1156, note T. Stefania ; RPC 2025. Comm. 50, note A. Aynès
Les lég-lumineuses - Des graines riches en protéines qui font pousser l'avenir (présentation des projets SPECIFICS et LETSPROSEED)
No full textInternational audiencePresentation of the SPECIFICS and LETSPROSEED research projects (ANR), which are joining forces to develop the production and consumption of grain legumes such as peas, faba beans, and soybeans, with the aim of making them pillars of sustainable agriculture and food systems.SPECIFICS aims to design pesticide-free cropping systems by mobilizing biological diversity, new sources of resistance, and agroecological levers to strengthen crop resilience and economic value.LETSPROSEED aims to improve the yield, quality, and processing of legume seeds to develop ingredients and foods rich in plant proteins.From soil to plate, legumes are sowing the seeds of the future!Présentation des projets de recherche (ANR) SPECIFICS et LETSPROSEED qui unissent leurs forces pour développer la production et la consommation des légumineuses à graines comme le pois, la féverole et le soja., afin de devenir des piliers d’une agriculture et d’une alimentation durables.SPECIFICS vise à concevoir des systèmes de culture sans pesticide, en mobilisant la diversité biologique, de nouvelles sources de résistance et des leviers agroécologiques pour renforcer la résilience des cultures et leur valorisation économique.LETSPROSEED tend à améliorer le rendement, la qualité et la transformation des graines de légumineuses pour développer des ingrédients et aliments riches en protéines végétales.Du sol à l’assiette, les légumineuses sèment l’avenir
Study of the effect of ultrasonication on MnO2: Morphological evolution from nanosheets to nanofibers and its implications for biomedical redox modulation
No full textInternational audienceTriclinic birnessite (TMA-birnessite) was synthesized and systematically transformed through controlled ultrasonication (10–30 min) to optimize its morphology and redox reactivity for biomedical use. Transmission electron microscopy revealed a progressive morphological evolution: from stacked nanosheets to individual monolayers, and ultimately to elongated nanofibers, driven by anisotropic fragmentation along Mn(III)O6 chains. X-ray diffraction analysis (Williamson-Hall model) indicated a 70 % reduction in crystallite size (from 9.6 to 3.1 nm) and a sixfold increase in microstrains (from 0.2 % to 1.3 %), reflecting extensive defect generation. Ultrasonication enhanced colloidal stability in aqueous media, as demonstrated by improved zeta potential (from –10 mV to –35 mV) and reduced hydrodynamic diameter (from 544 nm to 173 nm), though stability remained limited under physiological ionic strength. Kinetic studies using a pseudo-first-order model revealed morphology-dependent redox reactivity toward glutathione (GSH). Nanofibers exhibited a 1.5-fold faster GSH-mediated reduction rate (k ≈ 0.097 vs. 0.061 min−1 for nanosheets at 4.0 mM GSH), indicating superior antioxidant depletion—critical for targeting tumor microenvironments. Conversely, methylene blue assays indicated a higher oxidative activity for nanosheets, likely related to their higher Mn(III) surface content (41 vs. 33 % in nanofibers), but this test alone does not allow unambiguous identification of the reactive species involved. This interpretation was therefore validated using the terephthalic acid fluorescence probe, which specifically confirmed hydroxyl radical generation in the MnO2/H2O2 system and revealed a stronger OH• production for nanosheets than for nanofibers, particularly in the presence of GSH. These results establish a clear morphology-activity relationship: nanofibers primarily act as GSH scavengers, while nanosheets serve as ROS generators. This tunability positions ultrasonicated birnessite as a promising platform for biomedical applications requiring balanced antioxidant depletion and ROS generation