Scientific Publications of the University of Toulouse II Le Mirail
Not a member yet
92205 research outputs found
Sort by
Proportional modulation of proliferation and motility under 2D compressive stress depends on mesenchymal phenotype
No full textInternational audienceMechanical stresses, including compression, arise during cancer progression. In solid cancer, especially breast and pancreatic cancers, the rapid tumor growth and the environment remodeling explain their high intensity of compressive forces. However, the sensitivity of compressed cells to targeted therapies remains poorly known. In breast and pancreatic cancer cells, pharmacological PI3K inactivation decreased cell number and induced apoptosis. These effects were accentuated when we applied 2D compression forces in mechanically responsive cells. Compression selectively induced the overexpression of PI3K isoforms and PI3K/AKT pathway activation. Furthermore, transcriptional effects of PI3K inhibition and compression converged to control the expression of an autophagy regulator, GABARAP, whose level was inversely associated with PI3K inhibitor sensitivity under compression. Compression alone blocked autophagy flux in all tested cells, whereas inactivation of basal PI3K activity restored autophagy flux only in mechanically non-responsive compressed cells. This study provides direct evidence for the role of the PI3K/AKT pathway in compression-induced mechanotransduction. PI3K inhibition promotes apoptosis or autophagy, explaining PI3K importance to control cancer cell survival under compression
Towards a CuSEF (CubeSat Systems Engineering Framework)
No full textCubeSat technology has lowered the barrier to entry into space, enabling small organizations and universities to rapidly design and launch miniature satellites. This trend has also created a market in which companies are jostling to sell these systems and the services they provide.Cubesats projects are very often carried out in very specific contexts with small teams and limited budgets. What's more, in the face of stiff competition, industry players are trying to compress development time to keep costs down and deliver the product as quickly as possible. This leads to a very high mission failure rate.A key factor of this high failure rate is the lack of a rigorous yet lightweight systems engineering process adapted to these small, fast-paced projects. Traditional standards for systems engineering (such as the ISO/IEC/IEEE 15288 lifecycle standard or space agency process standards like ECSS) are often not applied on CubeSat projects, as they can be overly complex, resource-intensive, or ill-suited to the constraints of CubeSat-class missions. NewSpace teams (small start-ups or academic groups with limited budgets and personnel) typically operate in a “garage development” style – ad hoc design-build efforts using off-the-shelf parts – which can result in missed engineering steps and inadequate testing.This paper introduces the CubeSat Systems Engineering Framework (CuSEF), tailored for NewSpace, that bridges the gap between heavyweight standards and the practical realities of CubeSat development. CuSEF combines a simplified process model with modern methods and tools to provide structure without undue burden. By adapting the ISO 29110 standard for very small entities and integrating essential requirements from the ECSS space engineering guidelines, the framework aims to enhance the reliability of CubeSat missions while optimizing development cost and time. The following sections review the state of the art, detail the CuSEF framework (its process, methods, and toolset), discuss expected benefits, and conclude with future perspectives
Ausencia y omnipresencia de la familia en el teatro de la memoria de las presas del franquismo: Solo son mujeres de Carmen Domingo
No full textInternational audienc
Spectral scheme for an energetic Fokker-Planck equation with κ-distribution steady states.
No full textThe concern of the present paper is the design of efficient numerical schemes for a specific Fokker-Planck equation describing the dynamics of energetic particles occurring in thermonuclear fusion plasmas (runaway electrons for example). In the long-time limit, the velocity distribution function of these particles tends towards a thermal non-equilibrium κ-distribution function which is a steady-state of the considered Fokker-Planck equation. These κ-distribution functions have the particularity of being only algebraically decaying for large velocities, thus describing very well suprathermal particle populations. Our aim is to present two efficient spectral methods for the simulation of such energetic particle dynamics. The first method will be based on rational Chebyshev basis functions, rather than on Hermite basis sets, which are the basis of choice for Maxwellian steady states. The second method is based on a different polynomial basis set, constructed via the Gram-Schmidt orthogonalisation process. These two new spectral schemes, specifically adapted to the here considered physical context, shall permit to cope with the long-time asymptotics without significant numerical costs
Moment-SOS hierarchies for arrow-type polynomial matrix inequalities with applications to structural optimization
No full textThe Arrow Decomposition (AD) technique, initially introduced in [Mathematical Programming 190(1-2) (2021), pp 105-134], demonstrated superior scalability over the classical chordal decomposition in the context of Linear Matrix Inequalities (LMIs) if the matrix in question satisfied suitable assumptions. The primary objective of this paper is to extend the AD method to address Polynomial Optimization Problems (POPs) involving large-scale Polynomial Matrix Inequalities (PMIs), with the solution framework relying on moment-sum of square (mSOS) hierarchies. As a first step, we revisit the LMI case and weaken the conditions necessary for the key AD theorem presented in [Mathematical Programming 190(1-2) (2021), pp 105-134]. This modification allows the method to be applied to a broader range of problems. Next, we propose a practical procedure that reduces the number of additional variables, drawing on physical interpretations often found in structural optimization applications. For the PMI case, we explore two distinct approaches to combine the AD technique with mSOS hierarchies. One approach involves applying AD to the original POP before implementing the mSOS relaxation. The other approach applies AD directly to the mSOS relaxations of the POP. We establish convergence guarantees for both approaches and prove that theoretical properties extend to the polynomial case. Finally, we illustrate the significant computational advantages offered by the application of AD, particularly in the context of structural optimization problems
Solution methods for the VRP with sharing of deliveries between producers in local food logistic
No full textInternational audienceThis study addresses the logistical challenges in Short Food Supply Chains (SFSC), where producers face high logistical costs. A new variant of the Vehicle Routing Problem (VRP) is proposed, enabling producers to share their deliveries with partner producers. With a partner producer, a producer can either drop off goods for a customer (to be served by the partner producer) or pick up goods for a customer they will visit themselves during their routes.Although solving the Vehicle Routing Problem (VRP) is a key area in optimization, with certain variants tailored to the specificities of SFSC, such as Pickup and Delivery or split deliveries, few studies address a delivery sharing aspect like this.Three heuristic methods were tested: GRASP (Greedy Randomized Adaptive Search Procedure), ILS (Iterated Local Search), and VNS (Variable Neighborhood Search), which systematically explores multiple neighborhoods. Initial results show a significant reduction in logistical costs thanks to the sharing approach, while also highlighting an imbalance in the workload distribution between producers.Mots clés -Circuits CourtsAlimentaires de Proximité, VRP, mutualisation, méta-heuristiques Résumé Cette étude traite des défis logistiques dans les Circuits Courts Alimentaires de Proximité (CCAP), où les producteurs sont confrontés à des coûts logistiques élevés. Une nouvelle variante du problème de tournées de véhicules (VRP) est proposée, permettant aux producteurs de mutualiser leurs livraisons avec d'autres producteurs partenaires. Avec un producteur partenaire, un producteur peut soit lui déposer des marchandises pour un client (que ce producteur servira), soit prendre des marchandises pour un client qu'il visitera lui-même lors de ses tournées. Bien que la résolution du Problème de Tournées de Véhicules (VRP) soit un domaine clé en optimisation, avec certaines variantes adaptées aux spécificités des CCAP, comme le Pickup and Delivery ou les livraisons fractionnées, peu d'études abordent un aspect de mutualisation des tournées comme celui-ci. Trois méthodes de résolutions approchées ont été testées : GRASP (Greedy Randomized Adaptative Search Procedure), ILS (Iterated Local Search), et VNS (Variable Neighborhood Search), qui explore plusieurs voisinages de manière systématique. Les premiers résultats montrent une réduction significative des coûts logistiques grâce à la mutualisation, et mettent en évidence un déséquilibre dans la répartition des charges entre producteurs.</div
: Projeto GENgiBRe. “Relação com a natureza e igualdade de gênero. Uma contribuição à teoria crítica a partir de práticas e mobilizações feministas na agroecologia no Brasil”. Guia metodológico
No full textField research and its methodology are at the heart of the GENgiBRe project's knowledge construction and socialisation objectives. The Methodological Guide therefore constitutes an essential outcome of our project, which reflects our "research-action" approach and our feminist epistemology. The development of this Guide was based on important instruments already proven in the field of feminism and agroecology, such as the Sociobiodiversity Map, the River of Life, the Feminist Social Cartography and the Body-Territory, which were adjusted for the objectives of our project and completed by new instruments. Through this publication, we wish to continue this collective construction, making our Methodological Guide available to communities of researchers with converging interests.La recherche sur le terrain et sa méthodologie sont au cœur des objectifs de construction et de socialisation des connaissances du projet GENgiBRe. Le guide méthodologique constitue donc un aboutissement essentiel de notre projet, qui reflète notre approche "recherche-action" et notre épistémologie féministe. L'élaboration de ce guide est basée sur des instruments importants déjà éprouvés dans le domaine du féminisme et de l'agroécologie, tels que la carte de la sociobiodiversité, le fleuve de la vie, la cartographie sociale féministe et le corps-territoire, qui ont été adaptés aux objectifs de notre projet et complétés par de nouveaux instruments. A travers cette publication, nous souhaitons poursuivre cette construction collective, en mettant notre Guide méthodologique à la disposition de communautés de chercheur-e-s aux intérêts convergents.A pesquisa de campo e sua metodologia estão no centro dos objetivos de construção e socialização do conhecimento do projeto GENgiBRe. O Guia metodológico, portanto, constitui um resultado essencial do nosso projeto, que reflete nossa abordagem de “pesquisação” e nossa epistemologia feminista. O desenvolvimento deste Guia foi baseado em instrumentos importantes já provados no campo do feminismo e da agroecologia, como o Mapa da Sociobiodiversidade, o Rio da Vida, a Cartografia Social Feminista e o Corpo-Território, que foram ajustados para os objetivos do nosso projeto e completados por novos instrumentos. Através desta publicação, desejamos continuar esta construção coletiva, disponibilizando nosso Guia Metodológico para comunidades de pesquisadoras e pesquisadores com interesses convergentes
Influence du contexte d'administration sur les effets pharmacologiques des psychédéliques diméthyltryptamine (DMT) et 5-méthoxy-diméthyltryptamine (5-MeO-DMT)
No full textThe concept of set and setting refers to the extrapharmacological variables influencing the psychedelic experience. The primary objective of this study was to evaluate, using a translational approach, whether the administration context (setting) could influence the pharmacological effects, both desired and adverse, of the psychedelic substances DMT and 5-MeO-DMT. At the low dose of 0.5 mg/kg, 5-MeO-DMT induced an antidepressant-like effect 24 hours after intraperitoneal administration, both in naïve mice and in a mouse model of depression induced by prolonged exposure to corticosterone. After validating pleasant and aversive settings in mice, these effects were found to be modulated by the setting. While a positive environment amplified the antidepressant-like effect, a negative environment hindered it, leading to anxiogenic-like effects. Preliminary analyses of DMT revealed similar results, suggesting that the influence of the setting may extend to all psychedelics. Immunohistochemical analyses conducted in brain regions implicated in depressive disorders and emotion regulation demonstrated an increase in neuroplasticity markers in a positive setting. A reduction in the proportion of perineuronal nets (PNNs) surrounding parvalbumin-expressing neurons in the CA1 region of the hippocampus correlated with the antidepressant-like effect. Additionally, PSD-95 labeling, used as an index of glutamatergic synapse density, increased in the cingulate cortex (Cg2) in the positive setting, confirming enhanced synaptic plasticity. In humans, a systematic review of the literature, based on the PRISMA methodology, analyzed adverse events associated with ayahuasca, DMT, and 5-MeO-DMT in unsupervised, non-clinical supervised, and clinical settings. Among the 62 included studies, 8,053 adverse events were reported in 15,745 participants. These events were predominantly non-serious and transient, affecting cardiovascular, neurological, and psychiatric domains. A lower proportion of serious adverse events was observed during the administration in clinical contexts, partially explained by the exclusion of high-risk participants. Among the non-serious adverse events, transient anxiety was reported even in clinical settings, where the described settings were highly variable. These findings highlight the role of setting in modulating the pharmacological effects of DMT and 5-MeO-DMT, both for their desired and adverse events. They underline the need to optimize the conditions of their administration with a view to their use in therapeutics.Le concept de set and setting désigne les variables extra-pharmacologiques influençant l'expérience psychédélique. L'objectif principal de ce travail était d'évaluer, avec une approche translationnelle, si le contexte d'administration (setting) pouvait jouer un rôle dans les effets pharmacologiques, recherchés et indésirables, des substances psychédéliques DMT et 5-MeO-DMT. À la faible dose de 0,5 mg/kg, la 5-MeO-DMT induit un effet de type antidépresseur 24 heures après administration par voie intrapéritonéale, tant chez des souris naïves que dans un modèle murin de dépression induit par une exposition prolongée à la corticostérone. Après validation de contextes agréables et aversifs chez la souris, ces effets se sont révélés modulés par le setting. Alors qu'un environnement positif amplifie l'effet de type antidépresseur, un environnement négatif l'annule, laissant place à des effets de type anxiogènes. Des analyses préliminaires portant sur la DMT ont révélé des résultats comparables, suggérant que l'influence du contexte d'administration pourrait s'étendre à l'ensemble des psychédéliques. Des analyses immunohistochimiques, effectuées dans des régions cérébrales impliquées dans le trouble dépressif et la régulation des émotions ont mis en évidence une augmentation des marqueurs de neuroplasticité en setting positif. Une diminution de la proportion des perineuronal nets (PNNs) entourant les neurones à parvalbumine dans la région CA1 de l'hippocampe a été corrélée à l'effet de type antidépresseur. De plus, le marquage PSD-95, utilisé comme un index de densité des synapses glutamatergiques, a été augmenté dans le cortex cingulaire (Cg2) en setting positif, confirmant une plasticité synaptique accrue. Chez l'homme, une revue systématique de la littérature, basée sur la méthodologie PRISMA, a analysé les événements indésirables associés à l'ayahuasca, la DMT et la 5-MeO-DMT dans des contextes non supervisés, supervisés non cliniques et cliniques. Parmi les 62 études incluses, 8053 événements indésirables ont été reportés chez 15745 patients. Ces évènements étaient majoritairement non graves et transitoires, affectant les sphères cardiovasculaires, neurologiques et psychiatriques. Une plus faible proportion d'évènements indésirables graves a été observée lors de l'administration de ces substances en contexte clinique et s'explique en partie par l'exclusion des patients à risque. Parmi les évènements indésirables non graves, une anxiété transitoire est retrouvée y compris dans les contextes cliniques pour lesquels les settings décrits présentent une grande variabilité. Ces travaux mettent en évidence le rôle du setting dans la modulation des effets pharmacologiques de la DMT et de la 5-MeO-DMT, tant pour leurs effets recherchés qu'indésirables. Ils soulignent la nécessité d'optimiser les conditions de leur administration dans la perspective de leur utilisation en thérapeutique
