HAL: Hyper Article en Ligne
Not a member yet
3159010 research outputs found
Sort by
Preconception Generational Impacts on Male Reproduction
No full textCeci est une mise à jour d’Aurore Gely-Pernot, Preconception Generational Impacts Male, Editeur(s) : Michael K. Skinner, Encyclopedia of Reproduction (Second Edition), Academic Press, 2018, Pages 642–648, ISBN 9780128151457International audienceAlthough mammalian development is directly affected by maternal exposure to environmental stressors during pregnancy, there has been over the last decade increasing evidence of the effect of paternal preconceptional exposure on the health of future generations. This chapter give an overview of the main physical, chemical and socio-cultural agents able to impact offspring health after male preconceptional exposure. It give also an overview of epigenetic mechanisms possibly involved in paternal inheritance
Tunable synthesis of C-SiOxCy monoliths
No full textInternational audienceThis study establishes key structure–property relationships, offering valuable guidelines for designing porous monolithic C-SiOxCy materials for energy storage sensors, and electrocatalysis. We report a tunable sol-gel synthesis of monolithic C-SiOxCy composites with tailored physicochemical and electrical properties. By combining resorcinol, formaldehyde, TEOS, APTES, and kapok fibers, twenty-one formulations were prepared while systematically varying five synthesis parameters: TEOS-to-resorcinol molar ratio, sol concentration, sol pH, drying method, and pyrolysis temperature. The resulting composites exhibited silica contents ranging from 19 to 80 wt%, bulk densities from 0.10 to 1.11 g/cm³, specific surface areas up to 562 m²/g, and electrical conductivities reaching 8 S/cm. Structural analyses (SEM, ²⁹Si NMR, N2 adsorption) revealed that the materials consist of integrated hybrid networks rather than separate carbon and silica domains. Factor analyses highlighted the dominant roles of TEOS/R on composition and porosity, supercritical drying on texture, and pyrolysis temperature on conductivity. Acidic conditions and sol dilution promoted high surface areas and pore volumes, while alkaline pH and carbon-rich environments enhanced electrical transport
Grassland phases as ecological buffers: Reducing invasive weeds even under drought-induced stress in cropping systems
No full textInternational audienceAgricultural systems are increasingly vulnerable to biological invasions and climate extremes, particularly drought, which can disrupt competitive balances and favor invasive weed establishment. Ecological strategies such as integrating temporary grassland phases into crop rotations offer potential to enhance system resilience, yet their long-term effectiveness under drought stress remains poorly quantified. A 12-year field experiment in western France was used to evaluated five rotational systems differing in the duration (3 or 6 years) and nitrogen fertilization of grassland phases within annual crop rotations. Weed invasion patterns were assessed using hierarchical statistical models, and an integrative drought stress index was developed to capture both the intensity and duration of water deficits over time. The influence of grassland management on invasive weed richness, temporal dynamics, drought sensitivity, and weed carryover between phases was examined. Invasive weed richness increased linearly with the proportion of annual crops, while systems with prolonged, well-fertilized grasslands exhibited significantly reduced invasion pressure-even under drought. Grassland phases buffered the effects of climate stress and minimized weed persistence across years, particularly when nitrogen inputs were adequate. Conceptualizing the system as a dynamic source-sink model revealed that crops serve as invasion sources, while well-managed grasslands act as ecological sinks that suppress invaders over time. These findings highlight the value of spatial-temporal diversification as a nature-based solution to reduce weed invasion in a changing climate. Incorporating extended grassland phases into rotations can strengthen agroecosystem resistance to invasive species and reduce dependency on chemical control strategies, contributing to the design of more sustainable and climate-resilient agricultural landscapes
An innovative setup to study the breakage of SiO2 agglomerates under shear stress
No full textInternational audienceGranular materials are involved in many industrial processes such as mixing, compaction, etc. When the granular material is in the form of agglomerates, i.e. an assembly of aggregates, particle fragmentation might occur under shear stress. This can either be a benefit for the process and should be controlled, or an issue which must be avoided. This paper focuses on the study of agglomerate breakage under shear stress, presenting a new experimental set-up designed for industrial contexts. The stress range selected lead to two distinct regimes: at low stresses, agglomerates break into individualized fragments, while high stresses fines agglomeration leads to the formation of flakes. These observations contribute to quantify the breakage stress of initial agglomerates, showing agreement with findings in the existing literature
Strengthening temporal action segmentation through diffusion models
No full textInternational audienceThis paper addresses the task of temporal action segmentation and presents a joint approach that combines low-level and high-level video analysis techniques. Our approach introduces the usage of diffusion models to enhance the quality and accuracy of temporal action segmentation. This paper introduces a new method to segment actions in videos over time. We blend basic and advanced video analysis methods, using the diffusion technique from denoising to make our results more accurate. By combining text information with visual features from different levels of a video, we create a multi-stage process that generates diverse features using the denoising network and improves the quality of our visual data. By leveraging the interplay between denoising and high-level segmentation tasks, our approach offers several advantages. These include the incorporation of a feedback loop for iterative refinement, improved overall performance through synergy between the two tasks, enhanced robustness and generalization. Our approach achieves reliable accuracies of 83.4%, 90.7% and 77.6% on the Georgia Tech Egocentric Activities, 50 Salads and Breakfast datasets respectively
Oxygen vacancy engineering by La-incorporation into Co3O4 matrix for boosting catalytic oxidation of vinyl chloride: experimental and DFT evidences
No full textfffInternational audienceliste mot clef
Smoked fish from Gabon: nutritional benefits vs. contaminant risks
No full textInternational audienceSmoked fish is the most common form of fish consumption in many African countries. Smoking is likely to cause changes in nutritional value and in the concentration of certain toxic elements. We assessed these changes in the Bonga shad (Ethmalosa fimbriata, Bowdich 1825). Fatty acids (26), vitamin A, trace elements (14) and polycyclic aromatic hydrocarbons (PAHs, 24) were examined in E. fimbriata at different smoking durations (fresh, 24 h, 48 h and 72 h). Composition of smoked fish revealed high inter-individual variability. Smoking did not affect total fatty acid concentrations, but it led to a 4.5-fold decrease in vitamin A and a decrease in the concentrations of Ca, Mg, Mn, Pb and Sr. Meanwhile, it increased the concentrations of PAHs (by a factor of 42), Cd, Mo and Na. Despite these changes, toxic metals (As, Cd and Pb) and PAHs levels remained within safety limits, except for the B(a)P Toxic Equivalent (TEQ) in 72 h-smoked fish. High inter-individual variability in toxic metals, PAHs and nutrients concentrations is suspected to originate from the heterogeneity of the smoking process, and to natural variation in fish. Overall, our results highlight the safety of artisanal smoked fish for human consumption when processed under certain conditions. To further enhance consumer safety, dietary recommendations would advise ensuring fish skin integrity in order to reduce flesh contamination
Strengthening Biometric Fuzzy Vault Against Statistical Bias Exploitation
No full textInternational audienc
Integrated production and maintenance planning in imperfect hybrid manufacturing–remanufacturing systems with outsourcing and carbon emissions
No full textInternational audienceThis study investigates the integrated planning of production, maintenance, and quality control in a hybrid manufacturing-remanufacturing system, accounting for deterioration, variability in the quality of returned products, carbon emissions, and outsourcing opportunities. The network consists of a manufacturer collaborating with an outsourcing remanufacturing provider. The manufacturer operates a single failure-prone machine to produce new products and to remanufacture returned ones. Recovered products that the manufacturer cannot process are sent to the outsourcing provider for remanufacturing. The system generates harmful emissions, potentially leading to environmental taxes and sanctions. We formulate a mixed-integer nonlinear programming model to determine the optimal integrated manufacturing, remanufacturing, outsourcing, and preventive maintenance plan. Eventually, the proposed strategy minimizes total economic costs and defects and ultimately reduces carbon emissions. We use a global solver for solving small instances, while a genetic algorithm metaheuristic is developed for larger ones. Extensive computational experiments reveal that the developed genetic algorithm is highly efficient, achieving gaps of less than 0.95% within shorter execution times for small instances and significantly outperforming the solver in larger ones. The results show that the integrated outsourcing strategy, combined with accounting for carbon emissions from both new and remanufactured products, significantly reduces the reliance on new products, leading to notable cost savings and environmental benefits. These savings become more pronounced as the number of returns increases
Analyzing the long-term interest of agroforestry in the context of uncertainties
No full textNe pas diffuser l'article (qui n'est pas en accès libre)International audienceAgroforestry has been promoted as a sustainable land-use practice that combines trees and crops to optimize productivity and enhance ecosystem services. However, its long-term benefits are subject to uncertainties. This paper examines the conditions under which agroforestry remains competitive compared to conventional agriculture and forestry, highlighting how the integration of agroforestry can also limit adaptability in the face of environmental and economic change. Using a dynamic model, we explore the trade-offs between agroforestry and conventional land-use specialization, incorporating the concept of quasi-option value to underscore the importance of maintaining flexibility in decision-making under uncertainty. Our analysis of a hypothetical farm offers a framework for evaluating strategic choices under uncertainty across context-dependent agronomic and market conditions, providing a transparent assessment of when agroforestry is competitive and when it is not. Beyond sensitivity exploration, we provide a calibration-and-validation template with explicit data inputs so that practitioners can instantiate the model on specific farms or regions and assess whether agroforestry is adoption-worthy under their local conditions