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DESIMP'22 Désimperméabilisation des zones urbaines pour la protection de la qualité des cours d'eau et de la zone littorale du Golfe d'Aigues-Mortes : efficacité, leviers et freins
No full textInternational audienc
Influence of Seed structure on Volume distribution of α‐Synuclein Oligomer at Early Stages of Aggregation using nanopipette
No full textInternational audienceUnderstanding α-synuclein aggregation is crucial in the context of Parkinson's disease. The objective of this study was to investigate the influence of aggregation induced by preformed seeding on the volume of oligomers during the early stages, using a label-free, single-molecule characterization approach. By utilizing nanopipettes of varying sizes, the volume of the oligomers can be calculated from the amplitude of the current blockade and pipette geometry. Further investigation of the aggregates formed over time in the presence of added seeds revealed an acceleration in the formation of large aggregates and the existence of multiple distinct populations of oligomers. Additionally, we observed that spontaneously formed seeds inhibited the formation of smaller oligomers, in contrast to the effect of HNE seeds. These results suggest that the seeds play a crucial role in the formation of oligomers and their sizes during the early stages of aggregation, whereas the classical thioflavin T assay remains negative
Naming, relocating and dating the woods of Notre-Dame “forest”, first results based on collated data and archaeological surveys of the remains
No full textInternational audienceThe tragic fire of Notre-Dame Cathedral in Paris on April 15th 2019 has provided researchers with a wide variety of materials to study. The condition of the framework remains does not allow any reuse, which creates an unprecedented opportunity to study the charred pieces of the frame: about 10,000 for the highest estimates. But upstream from the wooden items study, an inventory is required to establish methods that are consistent with the potential of the charred remains of the cathedral's framework. The purpose of this article is therefore to present the problems raised, the methods applied, the potential of the remains of the n-dame's frame - so called the "forest" - and the first results
Allometric options for predicting tropical tree height and crown area from stem diameter
No full textpublié sur la plateforme de prerpints : Research SquareTree height and crown area are important predictors of aboveground biomass but difficult to measure on the ground. Numerous allometric models have been established to predict tree height from diameter (H–D) and crown area from diameter (CA–D). A major challenge is to select the most precise and accurate allometric model among existing ones, depending on the species composition and forest type where the model is to be applied. To propose a principle to select tree H–D and tree CA–D allometric models, we build a method based on k -fold cross-validation using a large dataset spanning six forest types from central Africa. We then compared the errors and biases using 22 previously established H–D and CA–D allometric model forms via three inter-comparable scenarios: locally derived for the forest type vs. regional vs. pantropical; regional (encompassing the forest type) vs . pantropical; regional (not encompassing the forest type) vs. pantropical model. H–D allometries were more variable across forest types in central Africa than CA–D allometries: (i) forest type explained 6% of the variance in H–D allometry and 2% of the variance in CA–D allometry, while species explained 9% and 2% of the variance in H–D allometry and CA–D allometry, respectively; (ii) for H–D allometry, the six forest types resulted in five best-fit models whereas, for CA–D allometry, four models provided the best fit for the six forest types. We recommend using allometric models specific to the forest type, preferentially to regional ones. Regional models should in turn be preferred to pantropical allometric models
Glutaredoxin regulation of primary root growth confers early drought stress tolerance in pearl millet
No full textInternational audienceSeedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millet’s early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modelling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including GWAS and QTL approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re- annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment
Reply to: Microbial dark matter could add uncertainties to metagenomic trait estimations
No full textInternational audienc
Beyond the surface: exploring social challenges in groundwater community monitoring implementation
No full textInternational audienceThe key tool for any groundwater manager is a network of piezometers for monitoring water levels in both unconfined and confined aquifers. This information, when generated at an appropriate time step and spatial scale, facilitates the assessment of annual recharge, tracking long-term stock depletion, modeling and estimating sustainable extraction limits, understanding aquifer-river interactions, implementing usage restriction measures, and evaluating their effectiveness. Unfortunately, most existing monitoring networks suffer from insufficient spatial density, primarily due to a lack of public agency resources. This has led to experimenting with citizen science and community monitoring approaches for water level data production. Despite the success highlighted in the literature, challenges in convincing users to engage in sensitive data-sharing are often overlooked. Based on a social science approach, this communication explores trust-building, technical measures, and data-sharing modalities, examining an experiment conducted by the authors in Northern Morocco
Human activities and densities shape insecticide resistance distribution and dynamics in the virus-vector Culex pipiens mosquitoes from Morocco
No full textInternational audienceBackground: Mosquitoes of the Culex pipiens complex are widely distributed vectors for several arboviruses affecting humans. Consequently, their populations have long been controlled using insecticides, in response to which different resistance mechanisms have been selected. Moreover, their ecological preferences and broad adaptability allow C. pipiens mosquitoes to breed in highly polluted water bodies where they are exposed to many residuals from anthropogenic activities. It has been observed for several mosquito species that anthropization (in particular urbanization and agricultural lands) can lead to increased exposure to insecticides and thus to increased resistance. The main objective of the present study was to investigate whether and how urbanization and/or agricultural lands had a similar impact on C. pipiens resistance to insecticides in Morocco.Methods: Breeding sites were sampled along several transects in four regions around major Moroccan cities, following gradients of decreasing anthropization. The imprint of anthropogenic activities was evaluated around each site as the percentage of areas classified in three categories: urban, agricultural and natural. We then assessed the frequencies of four known resistance alleles in these samples and followed their dynamics in five urban breeding sites over 4 years.Results: The distribution of resistance alleles revealed a strong impact of anthropization, in both agricultural and urbanized lands, although different between resistance mutations and between Moroccan regions; we did not find any clear trend in the dynamics of these resistance alleles during the survey.Conclusions: Our study provides further evidence for the role of anthropic activities in the selection and maintenance of mutations selected for resistance to insecticides in mosquitoes. The consequences are worrying as this could decrease vector control capacities and thus result in epizootic and epidemic outbreaks. Consequently, concerted and integrated disease control strategies must be designed that include better management regarding the consequences of our activities
Despite structural identity, ace-1 heterogenous duplication resistance alleles are quite diverse in Anopheles mosquitoes
No full textInternational audienceAnopheles gambiae s.l . has been the target of intense insecticide treatment since the mid-20th century to try and control malaria. A substitution in the ace-1 locus has been rapidly selected for, allowing resistance to organophosphate and carbamate insecticides. Since then, two types of duplication of the ace-1 locus have been found in An. gambiae s.l . populations: homogeneous duplications that are composed of several resistance copies, or heterogeneous duplications that contain both resistance and susceptible copies. The substitution induces a trade-off between resistance in the presence of insecticides and disadvantages in their absence: the heterogeneous duplications allow the fixation of the intermediate heterozygote phenotype. So far, a single heterogeneous duplication has been described in An. gambiae s.l . populations (in contrast with the multiple duplicated alleles found in Culex pipiens mosquitoes). We used a new approach, combining long and short-read sequencing with Sanger sequencing to precisely identify and describe at least nine different heterogeneous duplications, in two populations of An. gambiae s.l . We show that these alleles share the same structure as the previously identified heterogeneous and homogeneous duplications, namely 203-kb tandem amplifications with conserved breakpoints. Our study sheds new light on the origin and maintenance of these alleles in An. gambiae s.l . populations, and their role in mosquito adaptation
Freins et leviers pour une plus grande intégration culture-élevage à l'échelle territoriale
No full textCarrefour de l'innovation agronomique du jeudi 9 novembre 2023 à L’ENSAT de ToulouseNational audienceThe specialization of agriculture and livestock, the territorial concentration of production and the resultingimpacts on the environment call for a paradigm shift. To meet the sustainability challenges, reconnectingcrops and livestock on a local scale would make it possible to exploit the services associated with integrating livestock into cropping systems, and vice versa. Crop-livestock integration makes it possible to exploit biological synergies between animal and plant production through the exchange of nutrients (fertilization, feeding) and natural complementarities between species (biological control). However, these practices are not (yet) part of the current dominant agricultural model, and their development will require the removal of a number of obstacles, which, while not prohibitive, currently limit their scope.La spécialisation de l’agriculture et de l’élevage, la concentration territoriale des productions et les impactsinduits sur l’environnement, nécessitent un changement de paradigme. Pour répondre aux enjeux dedurabilité, reconnecter cultures et élevage à une échelle locale permettrait de valoriser les services liés àl’intégration de l’élevage dans les systèmes de culture, et inversement. L’intégration culture-élevagepermet en effet d’exploiter les synergies biologiques entre productions animales et végétales à traversl’échange de nutriments (fertilisation, alimentation) et les complémentarités naturelles entre espèces (luttebiologique). Pour autant, ces pratiques ne font pas (encore) partie du modèle agricole dominant actuel etleur développement nécessitera de lever certains freins qui à défaut d’être rédhibitoires, en limitentaujourd’hui la portée