Scientific Publications of the University of Toulouse II Le Mirail
Not a member yet
92205 research outputs found
Sort by
In-situ measurement of AlAs growth rate by magnification inferred curvature method
No full textInternational audienceDespite the development of numerous in-situ monitoring tools applied to MBE, the direct absolutemeasurement of growth rates remains challenging [1]. The calibration of group-III element fluxes, andconsequently the associated growth rate, is performed through various methods (such as RHEEDoscillations, equivalent pressure measurement, optical methods, quartz crystal microbalance, etc.) [2].However, these direct in-situ measurements are often constraining since valid only under specificconditions and/or involve indirect measurements that require the knowledge of additional parameters.In this study, we applied the magnified inferred curvature method (MIC) [3] to directly measurethe growth rate of slightly strained AlAs layers on GaAs substrate, and thus enabling to calibrate in-situ the Al effusion cells, and simultaneously controlling directly the growth rate and composition ofAlxGa1−xAs layers independently of their thickness, and the growth conditions. From MICmeasurements, we were able to deduce the elastic parameters at growth temperature, enabling us toachieve an universal calibration of the atomic flux for the aluminum cell. This calibration is alsoapplicable to other group-III element cells, provided they induce strain relatively to the substrate, andis fully and directly transferable from one epitaxy chamber to another.This method, when applied to the MBE growth of complex III-V epitaxial structures [4], such asBragg mirrors [5,6] and VCSELs, proves to be highly advantageous, significantly reducing the numberof calibration runs needed to achieve the desired device characteristics
A Complex Network Analysis Approach for Generating Realistic Instances of the Scheduled Service Network Design Problem
No full textLong-haul freight transportation forms the backbone of global supply chains and involves diverse types of carriers, e.g., liner shipping companies, rail freight operators, less-than-truckload carriers, express parcel companies, etc. Planning decisions across these applications can be assisted by solving the Scheduled Service Network Design Problem, a fundamental but computationally challenging optimization problem. However, most instances used in the literature are not accessible, and the few available benchmarks were not designed to reflect the structural properties of real-world freight transportation networks. To fill this gap, we introduce a new open-source generator of instances for the Scheduled Service Network Design Problem. Our generator leverages insights from Complex Network Analysis to reproduce key structural features of freight transportation networks, while allowing users to tune parameters to generate diversified instances. A computational study validates its ability to produce networks exhibiting metrics aligned with those of networks derived from existing freight applications. We also include features such as preprocessing rules, varied demand pattern generation, and network emulation to increase the value of our tool for both practitioners and researchers
El Taller de escrituras dramáticas y teatrales con población LGTBIQ+ · Transvivere: retornando a la esperanza
No full textEl acto mismo de escribir se convierte en un acto de resistencia, de sobrevivencia, si viene desde una subjetividad que ha sido rechazada y reprimida durante mucho tiempo. Cuando acepté el reto de dirigir un taller de escritura dramática y teatral con población migrante LGBTIQ+ sabía que sería un enorme desafío, que tendría obstáculos enormes y mucho trabajo por delante. Pero sabía también que era algo absolutamente necesario. No solamente porque era un vacío epistemológico que se necesitaba cubrir en el seno del programa TransMigrARTS, sino además porque quería probar lo importante que era el acto de escribir cuando se formaba parte de una población migrante, tanto desde lo geográfico como desde las diversidades sexuales y de género. Yo mismo hago parte de esta población y el acto de escribir me ha supuesto al mismo tiempo, una liberación y una necesidad venida desde lo más profundo de mi ser. Necesitaba ver lo que podría lograrse cuando otras personas migrantes y pertenecientes a los sectores LGBTIQ+ se sentaban a escribir juntxs
Les architectes de l'ombre : comprendre et modéliser les processus de construction collective des nids d'insectes sociaux
No full textInternational audienc
RespirAndo Actions performatives pour traverser l’expérience migratoire
No full textInternational audienceCan Roots Be Planted Amidst Migratory Movements Through Performative Actions? This article explores the performative dimension of the RespirAndo workshop, developed as part of the TransMigrARTS project, which seeks to transform the vulnerabilities of migrant populations through art. Implemented in Toulouse (France) and Aarhus (Denmark), the workshop employs performance as a means of using the body, movement, and breath as tools to strengthen support networks and well-being. RespirAndo Performative actions to transit the migratory experience. Using an applied research-creation methodology (ARC) based on performative writing through images, this article analyses two workshop sessions held in Aarhus in the spring of 2024: A Stone in the Path and Planting Roots. Through this exploration, we reflect on the creative power of art tore-signify the migratory experience, enabling new ways of inhabiting the world, forging connections, and envisioning collective futures of wellbeing for migrants.¿Es posible sembrar raíces en medio del movimiento migratorio desde acciones performativas? Este artículo explora la dimensión performativa del taller RespirAndo desarrollado dentro del proyecto TransMigrARTS, que busca transformar las vulnerabilidades de la población migrante a través del arte. Implementado en Toulouse (Francia) y Aarhus (Dinamarca), a partir de la performance, el taller propone el cuerpo, el movimiento y la respiración como herramientas para fortalecer redes de apoyo y de bienestar. Desde una metodología de investigación-creación aplicada (ICA), basada en la escritura performativa a partir de imágenes, el artículo analiza dos sesiones del taller en Aarhus durante la primavera de 2024: Una piedra en el camino y Sembrando arraigos. A través de esta exploración, reflexionamos sobre la potencia creadora del arte, para resignificar la experiencia migratoria, permitiendo nuevos modos de habitar el mundo, construir vínculos y proyectar futuros colectivos de bienestar para las personas migrantes.Est-il possible d’enraciner des liens au sein du mouvement migratoire à travers des actions performatives ? Cet article explore la dimension performative de l'atelier RespirAndo, développé dans le cadre du projet TransMigrARTS, qui vise à transformer les vulnérabilités des populations migrantes par les arts. Mis en œuvre à Toulouse (France) et à Aarhus (Danemark), cet atelier utilise la performance pour proposer le corps, le mouvement et la respiration comme outils de renforcement des réseaux de soutien et du bien-être. À partir d’une méthodologie de recherche-création appliquée (RCA), fondée sur l’écriture performative à partir d’images, cet article analyse deux sessions de l’atelier organisées à Aarhus au printemps 2024 : Une pierre sur la route et Semer des racines. Par cette exploration, nous réfléchissons au pouvoir créatif de l’art pour re-signifierl’expérience migratoire, permettant ainsi de nouvelles manières d’habiter le monde, de tisser des liens et de projeter des futurs collectifs debien-être pour les personnes migrantes
Conditioning a collective avoidance response in rummy‐nose tetra
No full textInternational audienceEscape waves in animal groups, such as bird flocks and fish schools, have attracted a lot of attention, as they provide the opportunity to better understand how information can efficiently propagate in moving groups, and how individuals can coordinate their actions under the threat of predators. There is a lack of appropriate experimental protocols to study escape waves in highly social fish, in which the number of individuals initiating the escape and the identity of the initiators are controlled. Indeed, highly social fish or obligate schoolers have a tendency to not respond well or to freeze when tested in experimental setups designed for single individuals. In this manuscript, we report the results of a pilot experiment with limited sample size using an aversive conditioning protocol to trigger a collective escape response to a green light in a group of rummy‐nose tetra ( Hemigrammus rhodostomus ). Our experimental results suggest that aversive conditioning can (i) be successfully used in this schooling species, (ii) trigger collective escape responses, and (iii) be transferred from the training setup to a new environment. We also introduce metrics to characterize learning and forgetting at group level. These results nurture promising future empirical research on the cognitive and behavioral mechanisms of escape responses in schools of fish, both at the individual and collective scales
The Influence of Bee Movements on Patterns of Pollen Transfer between Plants: An Exploratory Model
No full textFrom the symposium “Pollinator-plant interactions in a changing landscape: embracing integrative approaches across scales” presented at the annual meeting of the Society for Integrative and Comparative Biology, January 3–7, 2025International audienceMost—if not all—pollinators make foraging decisions based on learning and memory. In interaction with environmental conditions and competitive pressure, pollinators’ cognition shapes their movement patterns, which in turn determine pollen transfers. However, models of animal-mediated pollination often make simplifying assumptions about pollinator movements, notably by not incorporating learning and memory. Better considering cognition as a driver of pollinators’ movements may thus provide a powerful mechanistic understanding of pollen dispersal. In this exploratory study, we connect pollinator behavior and plant reproduction by using an agent-based model of bee movements implementing reinforcement learning. Simulations of two bees foraging together in environments containing twenty plants show how learning can improve foraging efficiency as well as plant pollination quality through larger mating distances and smaller self-pollination rates while creating spatially heterogeneous pollen flows. This suggests that pollinators’ informed foraging decisions contribute to genetic differentiation between plant subpopulations. We believe this theoretical exploration will pave the way for a more systematic analysis of animal-mediated plant mating patterns, as model predictions can be tested experimentally in real bee-plant systems
Evidence for symbolic use of ochre by Micoquian Neanderthals in Crimea
No full textInternational audienceOchre use is widely regarded as a potential marker of symbolic behavior in Paleolithic societies. We conducted a multiproxy analysis of 16 ochre pieces from Middle Paleolithic Micoquian sites in Crimea [Zaskalnaya V (ZSKV), ZSKVI, and Prolom II] and mainland Ukraine (Mukhovets), spanning up to 70,000 years. Using portable x-ray fluorescence, scanning electron microscopy coupled to energy-dispersive spectroscopy, and technological analysis, we identified deliberate modifications including grinding, scoring, flaking, and scraping. Three pieces (ZSKV-05, ZSKV-06, and ZSKV-07) show features exceeding utilitarian use: One is shaped into a crayon-like tool with repeated resharpening, another appears to be a crayon fragment, and a third bears engraved, polished surfaces. These traits suggest the intentional production of marks and curated use. While practical applications (e.g., hide processing) remain plausible for other specimens, the evidence supports symbolic use among some Crimean Neanderthals. Our results highlight their cognitive complexity and underscore the importance of regional, multiproxy approaches in evaluating the emergence of symbolic material culture
