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Measurement of the branching fraction ratio at large dilepton invariant mass
No full textInternational audienceA test of lepton universality between muons and electrons is performed using decays (where , ), in the dilepton invariant-mass-squared region above 14.3GeV. The data used for the measurement consists of beauty meson decays produced in proton-proton collisions, corresponding to an integrated luminosity of fb, collected by the LHCb experiment between 2011 and 2018. The ratio of branching fractions for and decays is measured to be , which is consistent with the Standard Model prediction of unity. This constitutes the most precise test of lepton flavour universality using decays with dilepton invariant-mass-squared above the mass, whilst being the first of its kind at a hadron collider
Pratiquer la cohabitation : analyse des modes interrelations entre biodiversité et sportifs dans le cadre de la pratique du trail
No full textProjet suivi par Julien GautheyLe projet de recherche et développement s’est notamment concrétisé à travers une recherche doctorale dont la thèse a été soutenue publiquement le 11 juillet 2024 au laboratoire Environnement et Dynamique des Territoires de Montagne (Edytem ; UMR 5204) à l’université Savoie Mont-Blanc. Ce rapport repose essentiellement sur les matériaux ainsi que les analyses menées pendant cette recherche doctorale. D’après l’Enquête Nationale sur les Pratiques Physiques et Sportives (ENPPS) menée par le ministère chargé des sports et l’Institut National de la Jeunesse et de l’Education Populaire auprès de 12 000 répondants, la pratique du trail réunit en 2020 plus d’un million de pratiquants en France. Cette pratique sportive se retrouve sur l’ensemble du territoire français et au-delà.Elle ne se limite ni au terrain montagnard, ni au temps des vacances ou aux espaces des courses organisées. À l’aune de cette recherche nous pouvons avancer que la pratique du trail est une activité diffuse dans le temps et dans l’espace dont la diversité des formes est d’une brûlante actualité. Elle pourrait se définir très sommairement par le fait de courir sur des sentiers comme l’anglicisme ‘trail’ utilisé pour la nommer le suggère.L’ensemble des recherches menées dans ce projet s’est concentré sur cette seule pratique. Le choix de cette focale resserrée a permis de capter les nuances d’engagement des sportifs et la diversité de leurs expériences. In fine, ce projet s’est attaché à récolter et analyser des matériaux qualitatifs pour rendre compte des rapports des traileurs à leurs environnements de pratique dans une approche compréhensive complémentaire à des approches quantitatives
Uma viagem ao passado: a mecânica da alteridade em dois dispositivos digitais
No full textInternational audienceThis chapter presents a reflexive and theoretical exploration of two original digital devices conceived and developed by the authors: R\FRAME (2019) and ] P P P [ (2023). Anchored in a research-creation methodology, these immersive and museographic devices employ augmented reality to interrogate dominant narratives of cultural heritage and reveal latent forms of otherness embedded within institutional frameworks of memory. Rather than offering an empirical analysis of audience reception, this study critically engages with the conceptual and spatial implications of these digital interventions. By reconfiguring visual, memorial, and corporeal experiences, the devices operate as speculative tools for exploring the dynamics between visibility and invisibility, presence, and absence, within the broader context of heritage mediatization. The chapter argues that such digital devices open alternative pathways for transmitting and re-articulating cultural memory, while simultaneously exposing the ideological structures that frame the production and dissemination of historical knowledge.Este capítulo presenta una exploración reflexiva y teórica de dos dispositivos digitales originales concebidos y desarrollados por los autores: R\FRAME (2019) y ] P P P [ (2023). Basados en una metodología de investigación-creación, estos dispositivos inmersivos y museográficos emplean la realidad aumentada para cuestionar las narrativas dominantes del patrimonio cultural y revelar formas latentes de alteridad incrustadas en los marcos institucionales de la memoria. En lugar de ofrecer un análisis empírico de la recepción del público, este estudio aborda de forma crítica las implicaciones conceptuales y espaciales de estas intervenciones digitales. Al reconfigurar las experiencias visuales, conmemorativas y corporales, los dispositivos funcionan como herramientas especulativas para explorar las dinámicas entre visibilidad e invisibilidad, presencia y ausencia, dentro del contexto más amplio de la mediatización del patrimonio. El capítulo sostiene que estos dispositivos digitales abren vías alternativas para transmitir y rearticular la memoria cultural, al tiempo que exponen las estructuras ideológicas que enmarcan la producción y difusión del conocimiento histórico.Ce chapitre présente une exploration réflexive et théorique de deux dispositifs numériques originaux conçus et développés par les auteurs : R\FRAME (2019) et ] P P P [ (2023). Ancrés dans une méthodologie de recherche-création, ces dispositifs immersifs et muséographiques utilisent la réalité augmentée pour interroger les récits dominants du patrimoine culturel et révéler les formes latentes d'altérité intégrées dans les cadres institutionnels de la mémoire. Plutôt que d'offrir une analyse empirique de la réception du public, cette étude s'intéresse de manière critique aux implications conceptuelles et spatiales de ces interventions numériques. En reconfigurant les expériences visuelles, mémorielles et corporelles, ces dispositifs fonctionnent comme des outils spéculatifs permettant d'explorer les dynamiques entre visibilité et invisibilité, présence et absence, dans le contexte plus large de la médiatisation du patrimoine. Le chapitre soutient que ces dispositifs numériques ouvrent des voies alternatives pour transmettre et réarticuler la mémoire culturelle, tout en exposant les structures idéologiques qui encadrent la production et la diffusion des connaissances historiques.Este capítulo apresenta uma exploração reflexiva e teórica de dois dispositivos digitais originais concebidos e desenvolvidos pelos autores: R\FRAME (2019) e ] P P P [ (2023). Ancorados em uma metodologia de pesquisa-criação, esses dispositivos imersivos e museográficos empregam realidade aumentada para questionar narrativas dominantes do patrimônio cultural e revelar formas latentes de alteridade incorporadas em estruturas institucionais de memória. Em vez de oferecer uma análise empírica da recepção do público, este estudo aborda criticamente as implicações conceituais e espaciais dessas intervenções digitais. Ao reconfigurar experiências visuais, memoriais e corporais, os dispositivos funcionam como ferramentas especulativas para explorar a dinâmica entre visibilidade e invisibilidade, presença e ausência, dentro do contexto mais amplo da mediatização do patrimônio. O capítulo argumenta que tais dispositivos digitais abrem caminhos alternativos para transmitir e rearticular a memória cultural, ao mesmo tempo em que expõem as estruturas ideológicas que enquadram a produção e a disseminação do conhecimento histórico
Measurement of the top-quark pole mass in dileptonic events at TeV with the ATLAS experiment
No full textInternational audienceA measurement of the top-quark pole mass is presented in events with an additional jet, , produced in collisions at TeV. The data sample, recorded with the ATLAS experiment during Run 2 of the LHC, corresponds to an integrated luminosity of 140 . Events with one electron and one muon of opposite electric charge in the final state are selected to measure the differential cross-section as a function of the inverse of the invariant mass of the system. Iterative Bayesian Unfolding is used to correct the data to enable comparison with fixed-order calculations at next-to-leading-order accuracy in the strong coupling. The process (), where top quarks are taken as stable particles, and the process (), which includes top-quark decays to the dilepton final state and off-shell effects, are considered. The top-quark mass is extracted using a fit of the unfolded normalized differential cross-section distribution. The results obtained with the and calculations are compatible within theoretical uncertainties, providing an important consistency check. The more precise determination is obtained for the measurement: GeV, which is in good agreement with other top-quark mass results
Elaboration de ferrites spinelles par impression 3D pour applications à haute fréquence
No full text(Mn,Zn)Fe2O4 and (Ni,Zn,Cu)Fe2O4 ferrites are widely used as soft magnetic materials for passive components (transformers, inductors) operating up to several MHz in power electronics applications, such as power converters. However, reducing the size of these components, which occupy about 40% of the volume of converters, could be facilitated by the design of complex-shaped cores potentially including property gradients.In this context, additive manufacturing techniques applied to ferrite magnetic cores present an interesting opportunity to improve core integration, particularly by enabling the realization of innovative architectures.The objective of this thesis is to study the potential of 3D printing magnetic cores based on MnZn and NiZnCu ferrites through paste extrusion and to demonstrate that the components produced using this shaping method can achieve magnetic performance comparable to, or even superior to, those obtained by the conventional die pressing process. Work on the formulation of the pastes has led to the optimization of the mass loading rate (82 wt% for MnZn ferrite and 84 wt% for NiZnCu ferrite), as well as an investigation into the influence of particle size and shape on viscosity. A degassing step for the paste was added to limit air inclusions and improve the green density of the printed parts.Process parameters, particularly printing speed and printing bed temperature, were adjusted based on systematic characterizations of the rheological behavior of the pastes. This approach enabled the printing of components with geometries corresponding to CAD models, in particular because of very good resistance to sagging during extrusion. The debinding and sintering cycles were defined to ensure effective densification while avoiding cracking of the components and ensuring the formation of the desired ferrimagnetic spinel phase for both MnZn and NiZnCu ferrites. Printed parts made with degassed pastes achieved a relative density greater than 90%, and their microstructure (grain size, residual porosity) could be correlated with powder characteristics and sintering parameters.In some cases, samples produced from uniaxial compaction exhibited higher losses than those printed, measuring 448 mW/cm³ compared to 363 mW/cm³ (for MnZn ferrite: at 1 MHz and under 50 mT). The study showed that the geometry of the components significantly influences eddy current losses and can induce dimensional resonance. We demonstrated that permeability is primarily related to porosity, whether macro or micro, and that grain size plays a key role in optimizing the magnetic performance of NiZnCu ferrites. We overcame the issue of low green density in printed parts by using a paste composed of two different particle sizes.Les ferrites (Mn,Zn)Fe2O4 et (Ni,Zn,Cu)Fe2O4 sont largement utilisés comme matériaux magnétiques doux pour les composants passifs (transformateurs, inducteurs) fonctionnant jusqu'à plusieurs MHz dans les applications d'électronique de puissance, telles que les convertisseurs de puissance. Toutefois, une réduction de la taille de ces composants, qui occupent environ 40 % du volume des convertisseurs, pourrait être facilitée par la conception de noyaux de forme complexe comprenant éventuellement des gradients de propriétés.Dans ce contexte, les techniques de fabrication additive appliquées aux noyaux magnétiques de ferrite constituent une opportunité intéressante pour améliorer l’intégration des noyaux, en accédant notamment à la réalisation d’architectures innovantes.L’objectif de cette thèse est d’étudier de potentiel de l’impression 3D de noyaux magnétiques à base de ferrites MnZn et NiZnCu par extrusion de pâte et de démontrer que les pièces élaborées avec cette méthode de mise en forme peuvent atteindre des performances magnétiques comparables, voire supérieures, à celles obtenues par le procédé conventionnel de pressage en matrice. Le travail sur la formulation des pâtes a permis l’optimisation du taux de charge massique (82 wt% pour ferrite MnZn et 84 wt% pour ferrite NiZnCu), ainsi que l’étude de l’influence de la granulométrie et de la forme des particules sur la viscosité. Une étape de dégazage de la pâte a été ajoutée pour limiter les inclusions d’air et améliorer la densité crue des pièces imprimées.Les paramètres de procédé, en particulier la vitesse d’impression et la température de support d’impression, ont été ajustés sur la base de caractérisations systématiques du comportement rhéologique des pâtes. Cette approche a permis d’imprimer des pièces avec des géométries correspondant aux modèles de CAO, notamment grâce à une très bonne résistance aux affaissements durant l’extrusion. Les cycles de déliantage et de frittage ont été définis pour garantir une densification efficace en évitant la fissuration des pièces et pour assurer la formation de la phase spinelle ferrimagnétique souhaitée pour les ferrites MnZn et les ferrites NiZnCu. Les pièces imprimées avec des pâtes dégazées ont atteint une densité relative supérieure à 90 % et leur microstructure (taille de grain, porosité résiduelle) a pu être reliée aux caractéristiques des poudres et des paramètres de frittage.Dans certains cas, les échantillons issus de la compaction uni-axiale présentent des pertes plus élevées que ceux imprimées 448 mW/cm³ contre 363 mW/cm³ (pour le ferrite MnZn : à 1 MHz et sous 50 mT). L’étude a montré que la géométrie des pièces influence significativement les pertes par courants de Foucault et peut induire une résonance dimensionnelle. Nous avons démontré que la perméabilité est principalement liée à la porosité, qu'elle soit macro ou micro et que la taille des grains joue un rôle clé dans l’optimisation des performances magnétiques des ferrites NiZnCu. Nous avons surmonté le problème de la faible densité à cru dans les pièces imprimées, par l’emploi d’une pâte composée de deux granulométries différentes
Integrative models of psychopathology and psychotherapy: A PRISMA-based scoping review
No full textInternational audienceIntroductionSince the 1970s there has been increasing interest in integrative approaches to psychopathology. Within this framework, numerous models have been developed. The aim of this manuscript is to inventory these models, provide a critical evaluation of them, and offer recommendations for their further development.MethodWe conducted a scoping review based on PRISMA guidelines. The search strategy included keywords related to psychotherapy and/or psychopathology, one keyword related to models or conceptualizations, and one keyword associated with the integrative notion. The selected studies focused exclusively on integrative models of psychopathology and/or psychotherapy. The research was carried out using PsycInfo, PubMed, and EMBASE databases.ResultsA total of 61 manuscripts were included in the systematic review. We identified a broad range of conceptual proposals, which can be categorized into three main types of models: 1) Models proposing a general framework for understanding psychopathology, 2) Models focusing on common factors in psychotherapy and 3) Models suggesting that a specific psychotherapy is inherently integrative.ConclusionsMany of these identified models face criticism for their lack of clear methodological development, limited empirical evidence, and/or restricted applicability to psychotherapeutic interventions. Future models should aim to address these limitations in order to advance the fieldIntroductionDepuis les années 1970, l’intérêt pour les approches intégratives de la psychopathologie n’a cessé de croître. Dans ce cadre, de nombreux modèles ont été développés. L’objectif de ce manuscrit est d’en dresser un inventaire, d’en proposer une évaluation critique et de formuler des recommandations pour leur développement futur.MéthodeNous avons réalisé une revue exploratoire selon les lignes directrices PRISMA. La stratégie de recherche comprenait des mots-clés liés à la psychothérapie et/ou à la psychopathologie, un mot-clé relatif aux modèles ou aux conceptualisations, ainsi qu’un mot-clé associé à la notion d’intégration. Les études sélectionnées portaient exclusivement sur les modèles intégratifs de la psychopathologie et/ou de la psychothérapie. La recherche a été effectuée dans les bases de données PsycInfo, PubMed et EMBASE.RésultatsAu total, 61 manuscrits ont été inclus dans la revue systématique. Nous avons identifié un large éventail de propositions conceptuelles, pouvant être classées en trois grandes catégories de modèles : 1) les modèles proposant un cadre général de compréhension de la psychopathologie, 2) Les modèles mettant l’accent sur les facteurs communs en psychothérapie et 3) Les modèles suggérant qu’une psychothérapie spécifique est intrinsèquement intégrative.ConclusionsNombre de ces modèles font l’objet de critiques en raison de leur manque de développement méthodologique clair, de preuves empiriques limitées et/ou de leur applicabilité restreinte aux interventions psychothérapeutiques. Les modèles futurs devraient s’attacher à surmonter ces limites afin de faire progresser le domaine
Prevailing effect of residual stresses and defects on the fatigue strength of net-shape parts produced with Laser Powder Bed Fusion (L-PBF) 316L stainless steel
No full textInternational audienceLaser Powder Bed Fusion (L-PBF) additive manufacturing enables the production of complex-shaped parts with high mechanical resistance. Such components exhibit a multi-scale microstructure, internal, sub-surface, and surface defects, a rough surface finish and a residual stress gradient in the as-built net-shape condition. All of these factors can alter the fatigue behaviour. This study aims to improve the understanding of the combined effect of various surface parameters on the fatigue behaviour of L-PBF 316L stainless steel by conducting an extensive experimental campaign. Uni-axial fatigue tests were carried out on six batches having an as-built or heat-treated microstructure and a net-shape, pre-corroded net-shape, single-defect net-shape or polished surface condition. Results were compared with data from the literature: as-built polished, pre-corroded polished, or single-defect polished specimens. Studied defects were process-induced (e.g. lack of fusion, spatter, gas pore) and artificial (i.e. corrosion pit, electric discharge machined defect). Their sizes ranged from 10 to 700 μm. The residual stresses gradients were characterized by X-ray diffraction. A Kitagawa–Takahashi diagram was used to illustrate the effects of the various parameters on the fatigue behaviour. Residual stresses and defects were the most influential factors on the fatigue strength of net-shape specimens over surface condition and sub-surface microstructure
Human Attachment and the Electrophysiological Dynamics of Emotion Regulation: An Event‐Related Potential Study
No full textInternational audienceABSTRACT Emotion regulation is pivotal in human interactions and well‐being. Modulating one's emotional state is intricately linked with psychological, behavioral, and physiological responses. Extensive research has explored how individuals with varying attachment orientations manage emotions, predominantly through self‐report measures and behavioral assessments. However, the influence of attachment orientations on temporal electrophysiological dynamics during emotion regulation tasks remains underexplored. Here, 90 adults' EEG brain activity was recorded while they engaged in tasks of attending to, reappraising, or suppressing emotions elicited by unpleasant images. Their attachment orientations were assessed using the Experiences in Close Relationships‐12 (ECR‐12) questionnaire to explore the association between Late Positive Potential (LPP) and attachment anxiety and avoidance amidst the deployment of emotion regulation strategies. Using Linear Mixed‐Effects Model analysis, our results revealed a lower amplitude of the LPP during cognitive reappraisal, suggesting the efficacy of this strategy in diminishing emotional intensity. Moreover, higher attachment anxiety exhibited increased LPP amplitude during both Reappraisal and Suppression, as well as during the negative natural condition, indicating heightened emotional responses. This study provides novel insights into the relationship between attachment orientations and emotion regulation, as evidenced by EEG‐based measurements of the LPP. The findings indicate that individuals with higher attachment anxiety display distinct electrophysiological responses, particularly in emotional scenarios
The Role of Earthworms in Mediating Environmental Impacts on Mountain Ecosystem Functioning
No full textInternational audienceAim Soils host a quarter of all terrestrial species, and the pivotal role played by earthworms in soil ecosystem functioning is thought to be paramount. Here, we aimed to quantify the causal influence of changing environments, especially climate, soil conditions, and vegetation type and structure, on earthworm diversity and the subsequent impacts on ecosystem functions. Location French Alps. Time Period 2016–2021. Major Taxa Studied Earthworms and plants. Methods Along 17 elevational gradients, we sampled climate, soil conditions, plant relevés, ecosystem functions, and earthworm diversity from soil environmental DNA. Through a causal inference framework and structural equation modelling, we quantified how climate conditions structure soil conditions and vegetation structure along the gradients, how these three compartments shape earthworm diversity, and how, in turn, earthworm diversity modulates ecosystem functions in addition to direct environmental impacts. Results Vegetation was the most important driver of earthworm diversity, with acquisitive plant strategies contributing to an increase in earthworm diversity, followed by soil organic matter. While climate was important, its impact on earthworm diversity was only indirect, through cascading effects mediated by vegetation and soil. In addition to the abiotic drivers, earthworm diversity had an important effect on three out of the four studied ecosystem functions (i.e., carbon stock, plant primary productivity and carbon and nitrogen limitation of microbes). In closed habitats, earthworm diversity was positively linked to proxies of carbon stock and carbon availability, while in grasslands, it was positively linked to proxies of nitrogen availability. Interestingly, aboveground productivity was found to be independent of earthworm diversity. Main Conclusions Our study underscores the central role of earthworm diversity in linking environmental drivers to ecosystem functioning. We emphasise the importance of incorporating earthworm diversity in models aiming to elucidate the cascading effects of climate change across various ecosystem compartments, ultimately shaping ecosystem functioning
Cortical evidence accumulation for visual perception occurs irrespective of reports
No full textInternational audiencePerceptual experience is a multi-faceted, dynamical process, tackled empirically through measures of stimulus detectability and confidence. To assess if stimulus detection and confidence can be explained by evidence accumulation, a form of sequential sampling of sensory evidence, we analyzed high-gamma activity from stereo-electroencephalographic data of 29 participants partaking in 3 pre-registered experiments. In an immediate-response experiment, individual channels and decoded multivariate latent variables in the visual, inferior frontal, and anterior insular cortices displayed functional markers of evidence accumulation. In two further experiments, this signal in the ventral visual cortex differentiated between (1) seen and unseen stimuli in delayed detection, (2) high and low intensity stimuli during passive viewing, and (3) levels of confidence when stimuli were seen. A computational model of leaky evidence accumulation successfully reproduced both behavioral and neural data. Overall, these results indicate that evidence accumulation explains key aspects of perceptual experience, encompassing both conscious access and monitoring