HAL Université de Toulouse, et Toulouse INP
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Differences in growth features between species are driving cereal-legume intercrop yield: A statistical learning approach based on aggregated dataset
No full textInternational audienceIncreasing crop diversification is crucial for developing more sustainable agricultural systems, and cereal-legume intercropping is a promising strategy. This study investigates the factors influencing the yield of cereal-legume intercrops using data from six field experiments in southwestern France, where durum wheat was intercropped with either faba bean or pea. We assessed how differences in plant traits (e.g., height or biomass growth rates) between the associated species were related to the intercrop productivity. Additionally, we developed a novel modeling approach, combining machine learning and mixed-effects models, to identify the key drivers of intercrop performance based on variable importance. Our results showed that interspecific differences in plant traits within intercrops, particularly in biomass accumulation rate, maximum leaf area index, and elongation rates, were the most important factors explaining intercrop yield. These traits and their differences mainly suggest that competitive processes shape the outcome of a mixture and highlight the importance of dynamic measurements in agronomic experiments. The relationship between species yield and trait differences was symmetric for both intercropped species. Furthermore, these relationships were scale-dependent, with trends observed at the aggregate level not always consistent at the level of individual experiments. Our study highlights the importance of considering trade-offs when designing intercropping systems for practical applications and demonstrates the value of combining machine learning with ecological knowledge to gain insights into complex agricultural systems from aggregated datasets
Probing the Higgs boson CP properties in vector-boson fusion production in the channel with the ATLAS detector
No full textInternational audienceThe CP properties of the Higgs boson are studied in the vector-boson fusion production mode. The analysis exploits the decay mode of the Higgs boson into two -leptons using 140 fb of proton-proton collision data at TeV collected by the ATLAS experiment at the Large Hadron Collider. Results are obtained using the Optimal Observable method. CP-violating interactions between the Higgs boson and electroweak gauge bosons are considered in the effective field theory framework, with the interaction strength described in the HISZ basis by , and in the Warsaw basis by , , and . No deviations relative to the Standard Model are observed, and limits are obtained on the strength parameters. The parameter is constrained to the interval [] at the 95% confidence level while is constrained to [], when considering both linear and quadratic effects of physics beyond the Standard Model
Diode PIN verticale sur diamant (100) autosupporté à base de couches i et n dopées phosphore
No full textNational audienceCet article présente la réalisation et la caractérisation de diodes bipolaires n + -i-p + en diamant sur substrat autosupporté (100) caractérisées électriquement jusqu'à 600 °C sous vide à l'aide d'un équipement unique en France. Les résultats obtenus mettent en évidence la faisabilité et les performances prometteuses des diodes PIN en diamant pour des applications en électronique de puissance
Tentative d'amélioration de l'évaluation de la numération des hématies et de l'hématocrite estimés par l'automate d'hématologie XN-1000V chez la chèvre
No full textIn goats, red blood cells are particularly small and very close in size or even identical to that of platelets, which poses a major challenge for hematology analyzers. This similarity complicates the differentiation between these two cell types and compromises the reliability of all variables associated with red blood cells, platelets, and thus hematocrit. The objective of this study was to assess the performance of the automated methods used by the Sysmex XN-V analyzer, electrical impedance and optical flow cytometry, by comparing them to the reference method of manual microhematocrit. Based on the analysis of 57 caprine blood samples, hematocrit values calculated using impedance (RBC-I × MCV/10) and optical cytometry (RBC-O × MCV/10) were both higher than manual microhematocrit, with the former showing a proportional and constant bias, and the latter a constant bias. In conclusion, neither method allows for a reliable estimation of hematocrit in goats: although innovative, flow cytometry does not prove sufficiently reliable for routine use in this species.Chez la chèvre, la taille des hématies est particulièrement petite et très proche ou identique à celle des plaquettes, ce qui pose un problème majeur pour les automates d’hématologie : cette particularité complique la distinction entre ces deux types cellulaires et compromet la fiabilité de l’ensemble des variables associées aux hématies et aux plaquettes et donc de l’hématocrite. L’objectif de cette étude a été d’évaluer l’aptitude des méthodes automatisées utilisées par le Sysmex XN-V, l’impédance électrique et la cytométrie de flux optique, en les comparant à la méthode de référence du microhématocrite. Sur 57 spécimens caprins analysés, l’hématocrite calculé à partir de l’impédance (RBC-I x MCV/10) et la cytométrie optique (RBC-O x MCV/10) sont supérieurs au microhématocrite manuel avec observation respectivement d’un biais constant et proportionnel et constant. En conclusion, aucune des deux méthodes ne permet une estimation fiable de l’hématocrite chez la chèvre : la cytométrie de flux, bien qu’innovante, ne s’avère pas suffisamment fiable pour être utilisée en routine dans cette espèce
Novel approach to probe ionic species mobility in molten salts electrolyte for Thermal Batteries
No full textInternational audienceMolten salt electrolytes play a crucial role in thermal battery cells, offering excellent electrochemical performance and zero self-discharge at room temperature before melting. However, the transport properties of ionic species in these media are not well understood, and much remains unknown about the factors that determine the effectiveness of one electrolyte over another.This study investigates the mobility of ionic species, particularly lithium and fluorine, in eutectic molten salt mixtures like LiF-LiCl-LiBr, commonly used in thermal batteries. Using advanced in situ high-temperature techniques, including high-temperature nuclear magnetic resonance (HT-NMR), pulsed field gradients (PFG), and electrochemical impedance spectroscopy (EIS), we aim to understand the ionic motion processes. The research also examines the binding of these salts with an MgO powder and the effect of compaction on retention properties.The LiF-LiCl-LiBr eutectic shows superior ionic conductivity compared to systems like LiCl-KCl due to its higher lithium concentration and greater lithium mobility. Lithium diffuses faster than other ionic species, such as fluorine, but its high melting point of 440 • C limits its operational temperature range. The compaction rate of bound pellets is key to electrolyte performance, influencing ionic mobility. Higher compaction enhances lithium diffusion but may cause leakage above certain thresholds, depending on salt type and temperature.This innovative approach enables rapid testing of various electrolytic compositions and binders, helping assess performance and the impact of manufacturing processes.</div
The role of reactive oxygen, nitrogen, and sulfur species in the integration of (a)biotic stress signals in legumes
No full textInternational audienceLegumes are crops of considerable economic and ecological significance. They are suitable for cultivation in a variety of environments and temperatures. They are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia, contributing to the enrichment of marginal soils with this essential nutrient, and reduce artificial fertilizer use. Similarly, legumes establish a widespread mutualistic association with soil fungi, involving a reciprocal transfer of nutrients. Global warming is reshaping the interactions of plants with their environment, exerting profound effects on global agricultural systems. Plants have evolved sensing, signalling, and adaptive molecular mechanisms to respond to (a)biotic stimuli. Reactive oxygen, nitrogen, and sulfur species (RONSS) are key players in stress tolerance mechanisms, and their homeostasis, mainly accomplished by antioxidant enzymes and metabolites, is essential to allow redox signalling while preventing oxidative damage. Here, we review recent findings, highlighting metabolic pathways of RONSS and antioxidants, with emphasis on their functions in signalling and protection in response to (a)biotic constraints in legumes. Special attention is paid to the molecular crosstalk between RONSS in response to multiple stimuli and notably how redox homeostasis adjustment can increase (a)biotic stress tolerance and potentially be exploited to mitigate the negative effects of climate change
Diving deep into kelp forest food webs using dietary DNA metabarcoding
No full textInternational audienceRefine our understanding of trophic conditions supporting the ecological integrity of Laminaria hyperborea forests in marine protected areas, by identifying key 'consumer-prey' interactions : i. Identifying key ressources for species of cultural or fisheries importance ; ii. Assessing their trophic reliance on kelp forest communities, iii. Delineating trophic guilds and analyze resource partitioning ; iv. Identifying major trophic linkages and functional redundancy
When coordination chemistry meets soft matter: From hybrid nanoparticles to assemblies
No full textInternational audienc
Variabilités Développementales et Culturelles des Représentations de Nature: Etude comparative entre 3 populations : Occidentale (France),Urbaine du Sud Global (Colombie), Autochtone du Sud Global (Colombie)
No full textInternational audienceThe human-nature connection (HNC) is a lever for action to achieve the sustainability of our societies, since it allows us to act simultaneously on the health of ecosystems and the health of human populations. This HNC varies according to the living environment of individuals, including physical, social, political and cultural environments, and also according to sociodemographic factors, such as age. Thus, inhabitants of countries in the Global North have a lower HNC than those in the Global South; individuals from indigenous peoples have a higher HNC than those in urban areas or the Global North; and children have a high HNC that decreases sharply from adolescence. To explain these disconnections, we came to study through qualitative analysis the representations of nature of adolescents from three different populations: French, urban Colombia, and Indigenous peoples of Colombia. The French have a naturalistic representation of nature opposed to humans (nature-culture distinction) that appears in adolescence, while Colombians have a sacred representation, particularly among indigenous peoples. Thus, it appears important, in order to limit this disconnection in Western countries, to strengthen experiences of living in nature during adolescence, and to contribute to creating imaginaries in which humans and non-humans are not in opposition.La connexion humain-nature (CHN) est un levier d'action pour atteindre la soutenabilité de nos sociétés, puisqu'elle permet d'agir simultanément sur la santé des écosystèmes et la santé des populations humaines. Cette CHN varie en fonction de l'environnement de vie des individus, notamment les environnements physiques, sociaux, politiques et culturels, et également en fonction de facteurs sociodémographique, tel que l'âge. Ainsi, les habitant.es des pays du Nord global présentent une CHN plus faible que ceux du Sud Global ; les individus de peuples autochtones ont une CHN plus élevée que celle des urbains ou du Nord Global ; et les enfants ont une CHN élevée qui diminue fortement dès l'adolescence. Pour venir expliciter ces déconnexions, nous sommes venues étudier par analyse qualitative les représentations de nature des adolescent.es de trois populations différentes : Française, Colombie urbaine, et Peuples autochtones de Colombie. Les Français ont une représentation de nature naturaliste et opposée à l'humain (distinction nature-culture) qui apparait à l'adolescence, tandis que les Colombiens ont une représentation sacrée, notamment chez les peuples autochtones. Ainsi, il apparait important, pour limiter cette déconnexion dans les pays occidentaux, de renforcer les expériences de vécu de nature à l'adolescence, et de contribuer à créer des imaginaires dans lesquels humains et non humains ne sont pas en opposition
Le séquençage à longue lecture de l'opéron 16S-ITS-23S permet d'étudier la transmission du microbiote maternel avec une résolution au niveau de la pseudo-souche
No full textInternational audienceWe developed an optimized bioinformatics pipeline to analyze PacBio HiFi long reads targeting the 16S-ITS-23S region, enabling fine taxonomic resolution down to the level of putative strains. This processing workflow includes quality control (FastQC, MultiQC), denoising with Swarm using various clustering parameters, chimera detection and removal with VSEARCH, and filtering of ASVs based on minimum abundance and presence across multiple samples to ensure biological robustness. Taxonomic affiliation is performed against the GTDB database, with low-confidence identifications (<90% identity) relabeled as “weak affiliation.” To group ASVs into putative strains, we apply hierarchical clustering based on Pearson correlation of abundance profiles (threshold 0.9). This approach allowed, for example, the clustering of 108 ASVs assigned to Escherichia coli into 45 distinct strains. Despite the high computational cost of the process (up to 41 CPU days for fine-resolution clustering), this pipeline provides a putative strain × abundance matrix suitable for studying maternal microbial transmission to piglets. Results show that transmission occurs predominantly during lactation, with about 2.7% of the initial maternal strains persisting until weaning, and a higher proportion of strains shared between piglets and their own mother compared to unrelated sows.Nous avons développé une pipeline bioinformatique optimisée pour analyser les lectures longues PacBio HiFi ciblant la région 16S-ITS-23S, permettant une résolution taxonomique fine jusqu’au niveau des pseudo-souches. Cette chaîne de traitement inclut un contrôle qualité (FastQC, MultiQC), un débruitage via Swarm avec différents paramètres de clustering, une détection et suppression des chimères par VSEARCH, ainsi qu’un filtrage des ASVs selon leur abondance minimale et leur présence dans plusieurs échantillons pour garantir la robustesse biologique. L’affiliation taxonomique est réalisée contre la base GTDB, avec un renommage des identifications faibles (<90 % d’identité) en « weak affiliation ». Pour regrouper les ASVs en pseudo-souches, nous utilisons un clustering hiérarchique basé sur la corrélation de Pearson des profils d’abondance (seuil 0,9). Cette approche a permis, par exemple, de regrouper 108 ASVs assignés à Escherichia coli en 45 souches distinctes. Malgré la forte charge computationnelle du traitement (jusqu’à 41 jours CPU pour le clustering à la résolution fine), ce pipeline fournit une matrice pseudo-souche × abondance exploitable pour étudier la transmission microbienne maternelle aux porcelets. Les résultats montrent que la transmission s’effectue majoritairement durant la lactation, avec environ 2,7 % des souches maternelles initiales persistant jusqu’au sevrage, et une plus grande part des souches partagées entre porcelets et leur mère comparé à des truies non apparentées