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Diversité et structure génomique d’une population de truite en expansion aux Iles Kerguelen : mise au point d’une approche de Poolseq
No full textNational audienceOur study aims to understand how demographic and evolutionary processes (genetic drift, migration, selection, mutation) shape genomic diversity and its structure in an expanding brown trout (Salmo trutta) population. Introduced to the Kerguelen Islands in the 1960s, S. trutta has now colonized 54 rivers and continues to expand. These populations have been monitored long-term since 1962 with regular sampling campaigns, which provide us with a rich collection of more than 50,000 samples (scales) distributed along the expansion front over a 50-year temporal gradient.We sequenced 13 pools (25 individuals/pool), corresponding to eight populations, including 3 ancient populations introduced in the 1960s and sampled on 2 to 4 dates, and 3 recent populations, having colonized waterways in the years 2000-2010 and sampled only once. DNA was extracted from epidermal cells attached to scale samples of 1-year-old fry. Sequencing was performed on an MGI sequencer (2 x 150 bp, 50X depth objective) by the EPGV with a preliminary study to determine whether library preparation with and without PCR affects sequencing. Library preparation was also adapted to ancient pools composed of degraded and low-concentration DNA, down to 2 ng/µL.The first results of bioinformatics analyses show that preparing libraries with PCR allows for 10X additional depth without reducing sequencing performance (coverage, duplication). This gain is not negligible, especially for older pools. Across the 13 pools, depth ranges from 35 to 62X, and the number of reads from 500 to 769 million. The SNP calling stage is underway and currently reveals 2.5 million SNPs after filtering for quality and depth.This study thus reveals that DNA extraction and poolseq are feasible from fry scale samples, even old and degraded, and allow obtaining quality genomic data. This study will eventually include 32 additional pools distributed over the same spatio-temporal gradient (45 pools in total). The prospects for the identification of SNPs under selection will be presented.Notre étude vise à comprendre comment les processus démographiques et évolutifs (dérive génétique, migration, sélection, mutation) façonnent la diversité génomique et sa structure dans une population de truite commune (Salmo trutta) en expansion. Introduite aux Iles Kerguelen dans les années 1960, S. trutta a aujourd’hui colonisé 54 cours d’eaux et continue encore son expansion. Ces populations font l’objet d’un suivi à long terme depuis 1962 avec des campagnes d’échantillonnage régulières, qui nous permettent de disposer d’une riche collection de plus de 50 000 échantillons (écailles) répartis le long du front d’expansion sur un gradient temporel de 50 ans.Nous avons séquencé 13 pools d’individus (25 individus/pool), correspondant à huit populations, dont 3 populations anciennes introduites dans les années 60 et échantillonnées sur 2 à 4 dates, et 3 populations récentes, ayant colonisé des cours d’eaux dans les années 2000-2010 et échantillonnées une seule fois. L’ADN a été extrait à partir de cellules épidermiques fixées aux échantillons d’écailles d’alevins âgés de 1 an. Le séquençage a été effectué sur séquenceur MGI (2 x 150 bp, objectif 50X de profondeur) par l’EPGV avec une étude préliminaire visant à savoir si la préparation de la librairie avec et sans PCR affecte le séquençage. La préparation des librairies a également été adaptée aux pools anciens composés d’ADN dégradés et peu concentrés, jusqu’à 2 ng/µL. Les premiers résultats des analyses bioinformatiques montrent que la préparation des librairies avec PCR permet d’obtenir 10 X de profondeur supplémentaire sans réduire la performance du séquençage (couverture, duplication). Ce gain n’est pas négligeable notamment pour les pools anciens. Sur les 13 pools, la profondeur varie de 35 à 62X, et le nombre de reads de 500 à 769 millions. L’étape de SNP calling est en cours et révèle pour le moment 2.5 millions de SNP après filtration sur la qualité et la profondeur.Ainsi cette étude révèle que l’extraction d’ADN et le poolseq sont réalisables à partir d’échantillons d’écailles d’alevin, même ancien et dégradés, et permettent d’obtenir des données génomiques de qualité. Cette étude inclura à terme 32 pools supplémentaires répartis sur le même gradient spatio-temporel (45 pools au total). Les perspectives pour l’identification des SNPs sous sélections seront présentées
Income Shocks, Bride Price, and Child Marriage in Turkey
No full textInternational audienceAbstract Early marriage persists in many countries in spite of legal prohibition. The role of income shocks and bride price norms is investigated in the context of Turkey. Using data from the Turkey Demographic and Health Surveys 1998 to 2018, rainfall shocks are exploited as an exogenous source of variation of household income. To study the role of marital payments, measures of shocks are interacted with a province-level indicator based on past prevalence of bride price. Estimation results show that girls exposed to a large negative shock during adolescence have a higher probability of being married before 15, if living in provinces with a high prevalence of bride price. More arranged and forced marriages are found after severe shocks in those provinces. Results suggest that daughter marriage, as a response to mitigate negative income shocks, is not limited to the poorest countries, and still contributes to household strategies in Turkey
Equilibrium Thermophysical Properties of CO<sub>2</sub> + Cyclohexanol + Toluene Mixtures at T = 293.15–353.15 K and p = 0.1–30 MPa
No full textInternational audienceEquilibrium thermophysical properties of ternary carbon dioxide (CO2) + cyclohexanol + toluene mixtures were investigated at temperatures of 293.15–353.15 K and pressures of 0.1–30 MPa. The study covered phase behavior, density, and Henry’s law constant. Measurements focused on the binary cyclohexanol/toluene (70 wt %/30 wt %) mixture and its combinations with CO2 across 11 mole fractions (0.1004–0.9747 mol/mol). A high-pressure cell with adjustable volume facilitated bubble and dew point pressure detection via visual phase transition observation, yielding saturation pressures from 1.67 to 15.90 MPa. Density data were acquired using a vibrating U-tube densimeter. Phase transition analysis revealed liquid–liquid immiscibility at CO2 mole fractions exceeding 0.6 mol/mol. Molecular simulations estimated the density and Henry’s law constant for the ternary mixture and its binary subsystem (cyclohexanol + toluene). At lower temperatures (293.15 and 303.15 K), density increased with rising CO2 mole fraction. At higher temperatures (333.15 and 353.15 K), density rose for low CO2 mole fractions (0.1–0.3 mol/mol) while decreasing at higher fractions (0.4–0.6 mol/mol). Experimental and simulated density values showed an average deviation of 1.6%, peaking at around 2.8%
Explainable Recommender System to Promote Lesser-Known POIs for Sustainable Tourism and Small Municipality Revitalization
No full textInternational audienceOvertourism has become a growing global challenge, contributing to overcrowding, environmental degradation, and negative impacts on local communities. While popular tourist destinations suffer from these issues, smaller municipalities and lesser-known areas with rich cultural, historical, and natural resources often remain under-visited, missing opportunities for economic development. Traditional tourism management strategies have struggled to address these challenges. This research aims to propose an explainable recommender system that promotes Lesser-Known Points of Interest (LKPs) as sustainable, culturally sensitive alternatives to Well-Known POIs (WKPs). LKPs pose a challenge for traditional recommendation methods, which typically prioritize popular options that are mentioned more frequently, leading to the cold start problem. By integrating heterogeneous data sources, the proposed system will provide personalized LKP recommendations tailored to individual travelers' preferences, offering more unique and rewarding experiences. These recommendations will be embedded within balanced itineraries that combine both popular and lesser-known destinations, promoting a more even distribution of tourism and revitalizing smaller municipalities. Crucially, the system will justify recommendations, enhancing traveler satisfaction and fostering greater acceptance of LKPs. This research represents a novel approach in travel recommendation systems, emphasizing LKPs not solely as substitutes for WKPs but as unique destination
Thermally conductive composites based on h-BN and LDPE with low environmental impact
No full textInternational audienceAs the electrification of various applications continues to advance, the efficient dissipation of heat in electronic devices has become increasingly critical. For example, heat sinks are devices in electronic cards with high thermal conductivity (~ 5 W/m.K) that allow to evacuate heat. In a first phD thesis the effect of the process on the microstructure (and especially the orientation) of boron nitride platelets (h-BN) into LDPE matrix was studied. The final thermal conductivity reached 4.25 W/m·K with 50 wt.% of h-BN. In a second phD thesis, the objective is to elaborate high thermally conductive and environmentally friendly composites. To date, a life cycle assessment (LCA) of the production of 1kg of h-BN by carbothermic process was performed and compared to that of another thermally conductive particle and that of a LDPE polymer matrix. The next step will be to draw up and compare the LCA of the production of 1kg of several composites with a thermal conductivity of 4.25 W/m.K
ECOGEN: An open-source software for simulation of cavitation bubble dynamics
No full textInternational audienceECOGEN is an open-source CFD platform designed for the numerical simulation of compressible multiphase and multiphysics flows. It serves both academic and industrial communities by facilitating research and innovation in fields such as aeronautics, space, defence, energy, and healthcare. Built on a flexible C++ framework, ECOGEN integrates advanced numerical models and methods to handle complex interface problems and highly unsteady flows. It supports multiple physical models (single-phase, multiphase with or without equilibrium), diverse physics (viscosity, surface tension, mass and thermal transfers), and various mesh types (Cartesian, unstructured, AMR). With its HPC capabilities, ECOGEN can efficiently run large-scale simulations on thousands of cores. ECOGEN’s capabilities extend to the detailed investigation of cavitation bubble dynamics in various complex environments. This includes the behaviour of bubbles near urinary stone surfaces, the collapse of gas bubbles above crevices, and cavitating flows around rocket turbopumps. Additionally, it enables the study of impulse-driven release of gas-encapsulated droplets and shock-induced cavitation in droplets. Recent advancements also explore the interaction between single cavitation bubbles and highly deformable solids, providing valuable insights into fluid-structure interactions
Shadowgraphy Study of Transport Properties in Cyclohexanol/Toluene Binary Mixtures
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L'union paradoxale des femmes avec la terre : source d'oppression et voie de réconciliation
No full textInternational audienceStarting from a diachronic perspective, this article examines the way in which the privileged relationship between women and Nature and, more broadly, between women and Territory, has nourished ideologies and systems of representation that are sometimes opposed: used by Western patriarchal ideology as a reason for exploitation and violence, this interconnection is nowadays put forward as a potential source of reparation and emancipation that heals and overcomes contemporary cultural and social fractures.In order to bring the ‘instituted imaginary’, the ‘instituting imaginary’ and the ‘creative imaginary’ - to use Cornelius Castoriadis's terminology - into tension, this research draws first on the philosophical reflections developed by Carolyn Merchant in The Death of Nature: Women, Ecology and the Scientific Revolution, which paved the way for ecofeminism, and by Alicia Puleo in Ecofeminist Keys for Rebels Who Love the Earth and Animals, according to which the condition of women results from a systematic subjugation - parallel to the capitalist exploitation of nature - imposed by the founding fathers of modern science. Above all, it analyses the way in which, in response to the instituted order that they denounce, and to the historical, social and environmental disasters of the Anthropocene, some artists develop a creative imagination based on the experience and aesthetics of care in order to propose a new world order. While the Spanish artists Lucía Loren and Ruth Montiel deploy a symbolism of care that is essentially that of a symbolic repair of the Earth - which also includes a performative dimension in the case of Lucía Loren's eco-agriculture - the Colombian artist Libia Posada, who is also a surgeon, carries out experiments in reconciliation aimed at healing women's bodies with and thanks to the environment that surrounds them. Although her primary aim is to make visible the systemic violence suffered by women, the artistic experience also enables them to reclaim their history, their bodies and their identity, by putting the territory to the test and developing new relationships between the female body and geography. Deconstructing patriarchal values, these artistic projects pave the way for the reconstruction of an ideal of the world, in which women are responsible for reconciling with the Earth on behalf of all humans.Partiendo de una perspectiva diacrónica, este trabajo examina el modo en que la relación privilegiada entre las mujeres y la Naturaleza y, más ampliamente, entre las mujeres y el Territorio, han alimentado ideologías y sistemas de representación a veces opuestos: utilizada por la ideología patriarcal occidental como motivo de explotación y de violencia, esta interconexión aparece hoy en día como una fuente potencial de reparación y emancipación que sana y supera las fracturas culturales y sociales contemporáneas.Para poner en tensión el “imaginario instituido”, el “imaginario instituyente” y el “imaginario creador” –siguiendo la terminología de Cornelius Castoriadis–, esta investigación se basa en primer lugar en las reflexiones filosóficas desarrolladas por Carolyn Merchant en La muerte de la naturaleza: mujeres, ecología y revolución científica, que abrió el camino al ecofeminismo, y por Alicia Puleo en Claves ecofeministas para rebeldes que aman a la Tierra y a los animales, según las cuales la condición de la mujer resulta de una subyugación sistemática –paralela a la explotación capitalista de la naturaleza– impuesta por los padres fundadores de la ciencia moderna. Analiza sobre todo el modo en que, frente a este orden instituido que denuncian, y ante los desastres históricos, sociales y medioambientales del Antropoceno, algunas artistas desarrollan un imaginario creativo basado en la experiencia y la estética del cuidado para proponer un nuevo orden mundial. Mientras las artistas españolas Lucía Loren y Ruth Montiel despliegan un simbolismo del cuidado que es esencialmente el de una reparación simbólica de la Tierra –la cual incluye también una dimensión performativa en el caso de la ecoagricultura de Lucía Loren–, la artista colombiana Libia Posada, definida por su doble condición de artista y cirujana, lleva a cabo experiencias de reconciliación dirigidas a sanar los cuerpos de las mujeres con y gracias al entorno que las rodea. Si bien su primer objetivo es visibilizar la violencia sistémica que sufren las mujeres, la experiencia artística también supone reapropiarse de su historia, su cuerpo y su identidad, poniendo a prueba el territorio y desarrollando nuevas relaciones entre el cuerpo femenino y la geografía.Deconstruyendo los valores patriarcales, estos proyectos artísticos abren el camino para la reconstrucción de un ideal del mundo, en el que las mujeres son responsables de reconciliarse con la Tierra en nombre de todos los seres humanos.Partant d’une perspective diachronique, cet article examine la manière dont la relation privilégiée entre les femmes et la Nature et, plus largement, entre les femmes et le Territoire, a nourri des idéologies et des systèmes de représentation parfois opposés : utilisée par l’idéologie patriarcale occidentale comme motif d’exploitation et de violence, cette interconnexion est de nos jours mise en avant comme une source potentielle de réparation et d’émancipation qui guérit et dépasse les fractures culturelles et sociales contemporaines.Afin de mettre en tension « l’imaginaire institué », « l’imaginaire instituant » et « l’imaginaire créateur » – selon la terminologie de Cornelius Castoriadis – cette recherche s’appuie d’abord sur les réflexions philosophiques développées par Carolyn Merchant dans La Mort de la nature : Les femmes, l’écologie et la Révolution scientifique, qui a ouvert la voie à l’écoféminisme, et par Alicia Puleo dans Clés écoféministes pour les rebelles qui aiment la Terre et les animaux, selon lesquelles la condition des femmes résulte d’un assujettissement systématique – parallèle à l’exploitation capitaliste de la nature – imposé par les pères fondateurs de la science moderne. Il analyse surtout la manière dont, face à cet ordre institué qu’elles dénoncent, et face aux désastres historiques, sociaux et environnementaux de l’Anthropocène, certaines artistes développent un imaginaire créatif basé sur l’expérience et l’esthétique du care pour proposer un nouvel ordre mondial. Alors que les artistes espagnoles Lucía Loren et Ruth Montiel déploient une symbolique du care qui est essentiellement celle d’une réparation symbolique de la Terre – laquelle comporte également une dimension performative dans le cas de l’éco-agriculture de Lucía Loren – l’artiste colombienne Libia Posada, qui exerce également le métier de chirurgien, réalise des expériences de réconciliation visant à guérir le corps des femmes avec et grâce à l’environnement qui les entoure. Bien que son objectif premier soit de visibiliser les violences systémiques subies par les femmes, l’expérience artistique implique également pour celles-ci une réappropriation de leur histoire, de leurs corps et de leur identité, qui passe par une « mise à l’épreuve » du territoire et le développement de nouveaux rapports entre le corps féminin et la géographie. Déconstruisant les valeurs patriarcales, ces projets artistiques ouvrent la voie à la reconstruction d’un idéal du monde, dans lequel les femmes sont responsables de la réconciliation avec la Terre au nom de tous les humains
Secondary ion mass spectrometry as a tool to analyze semiconductor opening switch diodes
No full textInternational audienceThis paper presents a secondary ion mass spectrometry (SIMS) method for the analysis of semiconductor opening switch (SOS) diodes, which are crucial in nanosecond pulsed power systems. The study addresses the gap in experimental measurements of doping concentration in SOS diodes, as the current literature contains mainly theoretical doping profiles. The development of a reliable method for measuring doping concentration is expected to advance SOS technology, given the limited number of manufacturers. The SIMS technique is used to determine the depth distribution and concentration of dopants. The method is adapted to study boron, aluminum, and phosphorus in silicon, with emphasis on detection over several hundred micrometers to clarify the doping profile of SOS diodes. The experimental procedure includes (i) preparation of the SOS diode sample by cutting, polishing, and gold plating; (ii) performing dynamic SIMS analysis using specific conditions for boron/aluminum (O2+/M+) and phosphorus (Cs+/M−) detection; and (iii) using a line scan mode to measure element intensities across the sample, with quantification based on reference samples. The developed SIMS conditions enabled the measurement of the depth distribution of the dopants over a range of 1150 μm with a 2 μm step and providing sufficient lateral resolution. The quantified profiles of boron, aluminum, and phosphorus in the SOS diode are presented. The experimental impurity profiles were in partial agreement with the theoretical doping profiles. This method provides access to the analysis of semiconductor devices with thick structures, which are commonly used in power electronics and solid-state pulsed power
