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contrôle optimal pour des modèles mathématiques de thérapies anticancéreuses
No full textThis thesis develops mathematical frameworks and numerical methods for nonlocal balance equations with applications to cancer treatment optimization. Nonlocal models, which incorporate interactions over finite spatial ranges through integral operators, offer more accurate representations of biological phenomena than traditional local partial differential equations.We first establish the mathematical theory for nonlocal conservation laws, proving existence and uniqueness of solutions through a two-stage approach : solving a linearized problem with frozen nonlocal terms via characteristics, then establishing a fixed point for the full system. This approach avoids the Kružkov entropy conditions typically required for local conservation laws. We then apply this framework to two tumor growth models. The first is a two-component system coupling tumor density and drug concentration, for which we develop optimal control theory. We prove well-posedness, non-negativity preservation, and existence of optimal controls, deriving necessary optimality conditions through an adjoint formulation.The second is a three-component model representing competition between tumor cells, healthy tissue, and nutrients. For this system, we exploit spherical symmetry to obtain a radial formulation in order to reduce the dimension of the problem.For the numerical solution, we develop two methods. A collocation scheme using cubic B-splines for spatial discretization combined with sixth-order backward differentiation formulas addresses the radial three-component model. A meshless method based on radial basis functions provides flexibility for complex geometries. Both methods are validated through manufactured solutions. The theoretical and numerical tools developed provide a foundation for optimizing cancer treatment protocols that account for the nonlocal nature of cellular interactions in tumor tissue.Cette thèse développe des cadres mathématiques et des méthodes numériques pour les équations de conservation non-locales avec applications à l’optimisation du traitement du cancer. Les modèles non-locaux, qui incorporent des interactions sur des portées spatiales finies à travers des opérateurs intégraux, offrent des représentations plus précises des phénomènes biologiques que les équations aux dérivées partielles locales traditionnelles.Nous établissons d’abord la théorie mathématique pour les lois de conservation non locales, prouvant l’existence et l’unicité des solutions par une approche en deux étapes :résolution d’un problème linéarisé avec termes non-locaux gelés via les caractéristiques,puis établissement d’un point fixe pour le système complet. Cette approche évite les conditions d’entropie de Kružkov typiquement requises pour les lois de conservation locales.Nous appliquons ensuite ce cadre à deux modèles de croissance tumorale. Le premier est un système à deux composantes couplant la densité tumorale et la concentration de médicament, pour lequel nous développons la théorie du contrôle optimal. Nous prouvons le caractère bien posé, la préservation de la non-négativité et l’existence de contrôles optimaux, dérivant les conditions d’optimalité nécessaires par une formulation adjointe. Le second est un modèle à trois composantes représentant la compétition entre cellules tumorales, tissu sain et nutriments. Pour ce système, nous exploitons la symétrie sphérique pour obtenir une formulation radiale pour réduire la dimension du problème.Pour la résolution numérique, nous développons deux méthodes. Un schéma de collocation utilisant des B-splines cubiques pour la discrétisation spatiale combiné avec des formules de différentiation rétrograde d’ordre six permet de résoudre le modèle radial à trois composantes. Une méthode sans maillage basée sur des fonctions de base radiales offre une flexibilité pour des géométries complexes. Les deux méthodes sont validées par des solutions manufacturées. Les outils théoriques et numériques développés fournissent une base pour optimiser les protocoles de traitement du cancer qui tiennent compte de la nature non-locale des interactions cellulaires dans le tissu tumoral
Ni-NbO<sub>x</sub> Bifunctional Catalysts for Selective Hydrodeoxygenation of m-Cresol to Toluene
No full textInternational audienceThe catalytic performances of a series of Ni supported on mesoporous silica (SBA-15) and niobia, as well as Ni-NbOx dispersed on SBA-15 were evaluated for the hydrodeoxygenation (HDO) of m-cresol at 300 °C under atmospheric pressure. Under the reaction conditions, hydrogenation and C-C hydrogenolysis pathways yielding only oxygenated products dominated over the monometallic Ni catalyst. In contrast, the Direct DeOxygenation pathway (DDO) leading to toluene was significantly promoted when Ni was in contact with oxophilic NbOx surface. Tuning the Ni-Nb ratio on silica revealed a remarkable enhancement of the DDO rate constant. Indeed, the kinetic rate constant determined over 5Ni5Nb/SBA was about 11 times higher than that measured on the catalyst containing only the Ni phase. This enhanced performance can be attributed to the formation of well-dispersed Ni-NbOx interfacial sites, where the hydrogenation capability of Ni associate with the oxophilic character of Nb⁵⁺/Nb⁴⁺ species allowing to a more efficient activation of the C-O bonding and promoting the DDO reaction pathway. These results offer valuable insights for the rational design of selective catalysts for the transformation of lignin-derived bio-oils into aromatic hydrocarbons
Essential oil production from seeds of carrot (Daucus carota L.) grown on phytomanaged trace element-contaminated soils
No full textInternational audienceThe cultivation of Daucus carota L. (carrot) on soils polluted with trace elements (TE) constitutes an innovative phytomanagement approach, combining significant ecological and economic benefits. This plant species exhibits a notable capacity to extract trace elements from the soil while generating valuable biomass, primarily intended for hydrodistillation to produce high-quality essential oils (EO). Carrots exhibit an enhanced capacity to accumulate cadmium in their leaf tissues, with a high bioconcentration factor (BCF = 1.71), as well as significant zinc accumulation. Furthermore, the cultivation of this biennial plant promotes an increase in soil microbial biomass, as assessed by phospholipid fatty acid (PLFA) content, specifically enriching populations of Gram− bacteria, Gram+ bacteria, and saprotrophic fungi, thereby contributing to the modulation of microbial dynamics and the alleviation of stress within soil microbial communities. The EO extracted from carrot seeds contain TE concentrations below the quantification limit compared to other commercially available EO. Chemical analysis of the EO reveals a composition similar to that of commercial oils, with the major components being carotol (27.53%), an oxygenated sesquiterpene, and sabinene (26.08%), a monoterpene hydrocarbon. These EO have been extensively evaluated for their biological properties, demonstrating significant antifungal activity against Fusarium culmorum (IC50 = 0.57 ± 0.11 mg/ml) and Zymoseptoria tritici (IC50 = 1.09 ± 0.12 mg/ml), as well as antigermination activity against Blumeria graminis spores (IC50 = 1.47 ± 0.15 mg/ml). Additionally, these EO exhibit notable herbicidal properties, particularly in inhibiting root elongation and germination of the monocots species Lolium perenne (ryegrass) and the dicots species Lactuca sativa (lettuce). These findings highlight the potential of carrot as a tool for phytoremediation and the production of high-value bioactive compounds
Composite P3HT/ZnO thin films via FTM for improved charge transport in OFETs
No full textInternational audienceZinc oxide (ZnO) nanorods, measuring 500 nm in diameter and 100 nm in length, were created in this article using an optimised hydrothermal low temperature technique. Using the newly created floating film transfer method, a large-scale oriented composite thin film of ZnO nanorod dispersion and poly (3-hexyl thiophene) is created. A thin film of the produced nanocomposite was placed to an active area of the p-type organic transistor in order to increase its mobility. The obtained high charge carrier hole mobility µ, of ˃0.08 cm2/Vs along the orientation direction is caused by the nanocomposite thin film, as has been established. As per the prior research, the achieved result is approximately two orders higher and represents a more than four-fold boost over the pristine polymer device. The XRD and SEM were utilized to examine the crystalline characteristics of the nanostructure, and the atomic force microscope was employed to investigate the thin film morphology of the nanocomposite
Des catastrophes, des hommes et des impôts : mécanismes fiscaux et réactions aux 'signes' dans l’Antiquité gréco-romaine
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John Hyrcanus’ conquests : a forgotten page of the Seleucid Fraternal War
No full textInternational audienceIt is generally assumed that the beginning of the conquests was a clear sign of the political independence of the Hasmonean rulers. In this paper, I consider together literary, numismatic and archaeological data to demonstrate that neither John Hyrcanus, nor Alexander Jannaeus, led their fights for their own purposes only. Their conquests must be evaluated in both their local and regional contexts. In the end, it appears that they acted as loyal vassals to their Seleucid and Lagid masters, taking their part in the civil war against the usurper Antiochos IX and his ally Ptolemy IX
Simulation-based Evaluation of the Impact of using Blockchain for Traceability in an Industry 4.0 Factory
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Unprecedented suspended solids load caused by record-breaking extremes in southern Brazil: the May 2024 event
No full textInternational audienceIn May 2024, intense precipitation and flooding impacted southern Brazil in what became the country’s worst climate disaster. The unforeseen volume of runoff was funneled into Patos Lagoon, the world’s largest choked coastal lagoon, transporting large amounts of suspended solids (SS) from the watershed and eroded margins. In this study, we estimate SS concentration, discharge, and mass budget in Patos Lagoon during the May 2024 extreme flood event. Given the challenges of monitoring such extreme events, a multi-proxy approach was adopted, integrating optical satellite data with in situ gravimetric samples, gauging station records, rating curves, and ADCP measurements. Results revealed unprecedented water discharge rates (May 2024 monthly average of 1.78×10 4 m³/s, 37% above the historical maximum) and high SS concentrations (up to 463 g/m³). Between April 1 st and June 30 th , more than 9 million tonnes of SS were delivered to the Patos Lagoon (9.77×10 6 ± 6.75×10 6 t), exceeding the typical annual load and comparable to about one month’s worth of the SS discharge from the Río de La Plata. This study provides the first estimate of the SS mass budget for Patos Lagoon, suggesting that most of the SS was exported to the coastal ocean, while a fraction likely accumulated within the lagoon. These findings offer a foundational understanding of how extreme hydrometeorological events influence sediment dynamics in choked coastal systems
Insights into air pollution at an urban site in the Greater Cairo Megacity : Minor PM2.5 sources with significant health risks
No full textInternational audienceThis study presents a comprehensive chemical characterization and source apportionment of PM2.5 in the Greater Cairo Area (GCA), one of the world's most polluted megacities. A total of 59 PM2.5 samples were collected continuously and on a 24-h basis during the winter of 2019–2020 at an urban background site and analyzed for a wide range of organic and inorganic species. The Positive Matrix Factorization (PMF) model was applied to identify and quantify as many as eleven sources contributing to PM2.5, highlighting the highly complex mixture of aerosols over the GCA. These sources include industrial emissions (coal combustion, lead and copper smelting), vehicular exhaust and non-exhaust emissions, open waste and wood burning, cooking, processed secondary aerosols, transported crustal dust, and mixed regional pollution. Local primary particulate controllable sources dominated elemental health risks, contributing 60% of the total non-cancer risk (NCR:1.7) and 52% of the total cancer risk (CR:2.1 × 10−5), despite representing a much smaller fraction of PM2.5 mass. Industrial emissions, though contributing only ∼12% of PM2.5 mass, were responsible for 37% of elemental NCR and 29% of CR. These findings underscore the need for targeted mitigation strategies addressing the burden of air pollution in GCA
Collecte récurrente des Déchets et Résolution Heuristique
No full textInternational audienceCollecte récurrente des Déchets et Résolution Heuristiqu