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Biodegradation of Bio-Based Polymers in Soil: Toward Sustainable Molecularly Imprinted Systems for Biopesticide Delivery
No full textInternational audienceMolecularly imprinted polymers (MIPs) are synthetic polymers with specific recognition sites for target molecules, offering tailored release properties. It is created by imprinting the target’s molecular structure into a polymer matrix during synthesis, providing selective binding sites to a target molecule with high affinity. While molecular imprinting technology has predominantly been applied in drug delivery, its adaptation for agro-industrial use requires polymers capable of withstanding various stresses—including shear, oxidative, thermal, and biological—while remaining biodegradable at the end of their lifecycle. Within the realm of sustainable polymer manufacturing, integrating monomers sourced from renewable origins is necessary but also poses a challenge. Given that the cross-linker typically comprises over 80% of the MIP composition, replacing it with a biobased substitute is a first step towards eco-friendlier MIPs. This project focuses on synthesizing novel biobased MIPs through precipitation free-radical polymerization, utilizing various biobased cross-linkers derived from plant oils, and polysaccharides, in contrast to the conventional petroleum-based reagents typically employed in molecular imprinting. However, it's important to note that sourcing from bio-derived materials doesn't automatically ensure good biodegradability. Consequently, the environmental fate of these new polymers is under examination. Their biodegradation is examined in microcosms replicating biotic and abiotic conditions found in natural environments, alongside an investigation into their impact on soil microbial communities. Using MIPs for the delivery of biopesticides allows for regulation of their release rate, ensuring a stable and enduring impact on the environment. This is important because even though biopesticides are a sustainable alternative to their conventional counterparts, their effectiveness is hindered by their brief persistence at the plant's target site, primarily due to factors like biodegradation and washing. This poses challenges to their widespread adoption. Biopesticides chosen to serve as templates for these newly developed delivery systems are evaluated for their antifungal efficacy against three prominent crop phytopathogens: Sclerotinia sclerotiorum, Botrytis cinerea, and Fusarium solani. This research aims to furnish policymakers with valuable insights for regulating the use of these new formulations in commercial applications
Inhibition de la digestion anaérobie des boues d'épuration urbaines par le propionate de sodium : production de biogaz et évolution de la communauté microbienne dans des réacteurs semi-continus
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Dans le périurbain, la révolution n'a pas encore eu lieu. Inégalités foncières et vulnérabilité des territoires ruraux dans la périphérie de Sfax en Tunisie : l'exemple de Mahrès
No full textInternational audienceSince its “Revolution”, Tunisia has been caught up in a deep crisis. Its “modern”,“intensive” agricultural model is reaching its limits, the economic insecurity offamily farmers is high, and food shortages are frequent. In this context, the aim ofthis article is to propose an analysis of Tunisia’s peri-urban rural territories whichcould represent a strategic challenge in responding to the popular aspirationsexpressed in 2011. So, in this paper, our study focuses on land dynamics inMahrès, in the periphery of Sfax. Based on fieldwork involving interviews withfarmers of different profiles and representatives of agricultural services, and the production of diachronic maps showing changes in local land use since the end of the 19th century, we highlight the current vulnerability of small farms in Mahrès. We particularly observe how land inequalities are being reinforced, and how thecurrent relations between Sfax and its rural periphery determine the economicdomination of small fellahs. Then, our work suggests that in Tunisia, a changein the dynamics of rural territories, based on new relationships between farmers,which would enable a new land development, should be encouraged.Depuis sa « Révolution », la Tunisie connaît une crise profonde. Son modèleagricole « moderne » atteint ses limites, la précarité économique des agriculteursfamiliaux est élevée, et les pénuries alimentaires sont fréquentes. Dans cecontexte, l’objectif de cet article est de proposer une analyse des territoiresruraux périurbains tunisiens qui pourraient servir de cadres stratégiques pourrépondre aux aspirations populaires exprimées en 2011. Pour cela, notre étudeporte sur les dynamiques foncières à Mahrès, dans la périphérie de Sfax. Àpartir d’un travail de terrain qui a donné lieu à la conduite d’entretiens avec desexploitants de différents profils et des représentants des services agricoles, et de laproduction de cartes diachroniques montrant les évolutions des usages du sol auniveau local depuis la fin du XIXe siècle, nous mettons en évidence la vulnérabilitéactuelle des petites exploitations mahressiennes. Nous observons comment lesinégalités foncières se renforcent, et comment les relations actuelles entre Sfaxet sa périphérie rurale déterminent la domination économique des petits fellahs.Ainsi, notre travail suggère qu’un changement dans la dynamique des territoiresruraux, à partir de nouvelles relations entre agriculteurs, qui permettraient unenouvelle mise en valeur du foncier, est à encourager
Présentation pour l'atelier " Prompt Engineering : l'art des requêtes efficaces "
No full textThis workshop offers an in-depth exploration of Prompt Engineering, the art of crafting optimized queries to interact effectively with AI models such as ChatGPT, Mistral, or Llama. The workshop will guide you through best practices for designing prompts that yield accurate and creative results.Through concrete examples and hands-on exercises, we will cover the theoretical foundations by discussing relevant scientific literature, as well as advanced tips to enhance the efficiency of your queries. The goal is to equip participants with the tools to maximize the outcomes of their interactions with AI systems while gaining a deeper understanding of how these models work.This document is the presentation used during the Prompt Engineering workshop held on December 13th by ObTIC at Bibliothèque Nationale de France. It outlines the objectives, methodology, and key content of the session, focusing on best practices for crafting effective prompts for AI models like ChatGPT, Mistral, and Llama. The presentation includes insights into theoretical foundations, practical exercises, and advanced techniques to optimize AI interactions. Designed for participants and interested readers, it serves as a reference for understanding and applying prompt engineering principles.Ce document est la présentation utilisée lors de l'atelier sur le Prompt Engineering organisé le 13 décembre par ObTIC à la Bibliothèque Nationale de France. Il expose les objectifs, la méthodologie et les principaux contenus de la session, en se concentrant sur les meilleures pratiques pour élaborer des prompts efficaces pour des modèles d'IA tels que ChatGPT, Mistral et Llama. La présentation comprend des éléments sur les fondements théoriques, des exercices pratiques et des techniques avancées pour optimiser les interactions avec l'IA. Conçu pour les participants et les lecteurs intéressés, il sert de référence pour comprendre et appliquer les principes du prompt engineering
Boundary Objects in the Preliminary Phases of Management, Design and Engineering: Literature review
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Multi-aerial pursuit of an intruder drone using a behavioral approach based on energy
No full textInternational audienceThe pursuit-evasion is a model describing many practical problems and applications in the context of Unmanned Aerial Vehicles (UAVs). In this paper, we propose a solution based on a multi-agent scheme with robustness that is able to capture agile intruders. Our solution uses a control scheme based on energy dissipation and robustness to avoid numerical approximations, unlike solutions that solve the Hamilton-Jacobi-Isaacs (HJI) in a numerical way. In addition, the proposed controller ensures asymptotic stability using the Lyapunov theory, with smooth state changes and guarantees the capture of the target. Experimental results demonstrate the performance of the proposed solution even in presence of an agile intruder
Geospatial Uncertainties: A Focus on Intervals and Spatial Models Based on Inverse Distance Weighting
No full textLecture Notes in Networks and SystemsInternational audienceProcessing geospatial data requires to manage many sources of uncertainties; some appear in classical inference problems, some others are specific to this setting. The goal of this paper is to study the management of these uncertainties via standard intervals and sets when the inference model considered relies on inverse distance weighting. We provide a general discussion with examples, together with a study of the associated optimisation problems induced by different sources of uncertainty. We conclude the paper by an illustration on a semi-synthetic use case, generated according to data recorded via real studies
Soft Learning Probabilistic Circuits
No full textInternational audienceProbabilistic Circuits (PCs) are prominent tractable probabilistic models, allowing for a range of exact inferences. This paper focuses on the main algorithm for training PCs, LearnSPN, a gold standard due to its efficiency, performance, and ease of use, in particular for tabular data. We show that LearnSPN is a greedy likelihood maximizer under mild assumptions. While inferences in PCs may use the entire circuit structure for processing queries, LearnSPN applies a hard method for learning them, propagating at each sum node a data point through one and only one of the children/edges as in a hard clustering process. We propose a new learning procedure named SoftLearn, that induces a PC using a soft clustering process. We investigate the effect of this learning-inference compatibility in PCs. Our experiments show that SoftLearn outperforms LearnSPN in many situations, yielding better likelihoods and arguably better samples. We also analyze comparable tractable models to highlight the differences between soft/hard learning and model querying
Uniform Polymer Microspheres by Photoinduced Metal‐Free Atom Transfer Radical Precipitation Polymerization
No full textInternational audienceHerein, a photoinduced method is introduced for the synthesis of highly cross-linked and uniform polymer microspheres by atom transfer radical polymerization (ATRP) at room temperature and in the absence of stabilizers or surfactants. Uniform particles are obtained at monomer concentrations as high as 10% (by volume), with polymers being exempt from contamination by residual transition metal catalysts, thereby overcoming the two major longstanding problems associated with thermally initiated ATRP-mediated precipitation polymerization. Moreover, the obtained particles have also immobilized ATRP initiators on their surface, which directly enables the controlled growth of densely grafted polymer layers with adjustable thickness and a well-defined chemical composition. The method is then employed successfully for the synthesis of molecularly imprinted polymer microspheres