226280 research outputs found
Sort by
Euclid preparation. Galaxy 2-point correlation function modelling in redshift space
No full textInternational audienceThe Euclid satellite will measure spectroscopic redshifts for tens of millions of emission-line galaxies. In the context of Stage-IV surveys, the 3-dimensional clustering of galaxies plays a key role in providing cosmological constraints. In this paper, we conduct a model comparison for the multipole moments of the galaxy 2-point correlation function (2PCF) in redshift space. We test state-of-the-art models, in particular the effective field theory of large-scale structure (EFT), one based on the velocity difference generating function (VDG), and different variants of Lagrangian perturbation theory (LPT) models, such as convolutional LPT (CLPT) and its effective-field-theory extension (CLEFT). We analyse the first three even multipoles of the 2PCF in the Flagship 1 simulation, which consists of four snapshots at . We study both template-fitting and full-shape approaches and find that with the template-fitting approach, only the VDG model is able to reach a minimum fitting scale of at without biasing the recovered parameters. Indeed, the EFT model becomes inaccurate already at . Conversely, in the full-shape analysis, the CLEFT and VDG models perform similarly well, but only the CLEFT model can reach while the VDG model is unbiased down to at the lowest redshift. Overall, in order to achieve the accuracy required by Euclid, non-perturbative modelling such as in the VDG or CLEFT models should be considered. At , the CLPT model is sufficient to describe the data with high figure of merit. This comparison selects baseline models that perform best in ideal conditions and sets the stage for an optimal analysis of Euclid data in configuration space
Understanding dopaminergic dose reduction following STN-DBS: mediation analysis
No full textInternational audienceBackground Levodopa equivalent dopaminergic dose (LEDD) reduction after subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson’s disease varies widely. Identifying predictors may guide patient selection and programming. Our objectives were to identify predictors of LEDD reduction and to test whether motor improvement mediates this association. Methods Data from 144 patients treated by STN-DBS were analysed. Predictors of LEDD reduction were selected using the Boruta algorithm, a machine-learning method comparing variable importance to randomised features and then tested in a structural equation model for direct and motor-mediated effects. Results Mean LEDD reduction was 41.7% (±38.2%) and motor improvement was 48.6% (±26.7%) at 1 year. Among the four predictors identified by Boruta, lower baseline LEDD (β=0.39, p=0.001), greater axial impairment (β=−0.25, p=0.003) and higher total volume of tissue activated (β=−0.17, p=0.031) were directly associated with lower LEDD reduction, independent of motor improvement. Sensorimotor STN overlap was not directly linked to LEDD reduction but was positively associated with motor improvement (β=0.34, p=0.001), which showed a trend-level effect on LEDD reduction (β=0.16, p=0.065). The total effect of sensorimotor STN overlap on LEDD reduction was not significant. Discussion Dopaminergic dose reduction after STN-DBS is constrained by preoperative axial symptoms and stimulation spread, independently of motor improvement, while sensorimotor STN overlap improves motor symptoms but not dose reduction. Integrating motor phenotype with anatomical guidance may enhance medication management post DBS
Target trial emulation to replicate randomised clinical trials using registry data in multiple sclerosis
No full textInternational audienceBackground: Target trial emulation (TTE) offers a formal framework for causal inference using observational data, but its validity must be evaluated in each research domain by replicating randomised clinical trials (RCTs). We aimed to replicate eight RCTs evaluating the efficacy of disease-modifying therapies (DMTs) in multiple sclerosis (MS) using French registry data.Methods: This multicentre, retrospective, observational study was conducted using data extracted in December 2023 from the Observatoire Français de la Sclérose en Plaques (OFSEP) database. For each emulated trial, patients were included when they initiated one of the DMT evaluated in the corresponding RCT and met its inclusion criteria. Clinical outcomes were the annualised relapse rate and 3-month confirmed Expanded Disability Status Scale progression. Radiological outcomes were new/enlarged T2-lesions and new gadolinium-enhanced T1-lesions on a brain MRI. A targeted maximum likelihood estimator was used to estimate the treatment effect adjusted for confounding factors between groups and corrected for censoring and missing outcome assessment.Results: 14 111 patients were included in eight emulated trials: ASSESS (fingolimod vs glatiramer acetate), BEYOND (interferon beta vs glatiramer acetate), CONFIRM (dimethyl fumarate (DMF) vs glatiramer acetate), OPERA (ocrelizumab vs interferon beta), REGARD (interferon beta vs glatiramer acetate), RIFUND-MS (rituximab vs DMF), TENERE (teriflunomide vs interferon beta) and TRANSFORMS (fingolimod vs interferon beta). Treatment effects estimated in emulated trials were concordant with RCT findings in seven of eight trials for relapse rate, and in all six trials assessing disability progression. Radiological outcomes were more challenging to replicate; concordance was achieved in three of five trials for new T2-lesions, and one of four trials for new gadolinium-enhanced T1-lesions.Conclusion: The combined use of a TTE methodology and high-quality registry data is a valid tool to evaluate treatment effectiveness in MS
What Statistics Don’t See: Human Rights as a Narrative for Global Climate Constitutionalism
No full textInternational audienc
Ecole internationale d'été et d'hiver sur les musées en transition
No full textInternational audienceThis chapter presents the two summer and winter schools organized at the University of Toulon (France) and the University of Trois-Rivières at UQTR (Quebec), funded by the Samuel de Champlain program, in the book Musée et écologie, missions, engagements et pratiques (Museums and Ecology: Missions, Commitments, and Practices), in the fourth part entitled “Le musée acteur écoresponsable” (The Museum as an Eco-Responsible Actor), coordinated by Aude Porcedda. Presentation of the book: Faced with the climate emergency and increasing threats to life on Earth, museums must solve a crucial equation: reducing their environmental impact while strengthening their social and cultural role. In this book, more than 80 museum professionals, scientists, and artists come together to discuss the development of strategic guidelines and eco-responsible practices. Musée et écologie (Museums and Ecology) provides an overview of the initiatives of a community committed to creating sober and socially responsible museums, and offers conceptual and practical keys for the eco-design of museums.Ce chapitre présente les deux écoles été et hiver organisées à l'université de Toulon et de l'université Trois-Rivières à l'UQTR financées par le programme Samuel de Champlain au sein de l'ouvrage Musée et écologie, missions, engagements et pratiques, dans la 4ème partie intitulée "Le musée acteur écoresponsable" cordonnée par Aude Porcedda . Présentation de 'l'ouvrage : face à l’urgence climatique et à la multiplication des atteintes au vivant, les musées ont à résoudre une équation décisive : diminuer leur impact écologique tout en renforçant leur rôle social et culturel. Dans cet ouvrage, ce sont plus de 80 acteurs des musées – professionnels, scientifiques et artistes – qui se mobilisent et réfléchissent à la production d’orientations stratégiques et de pratiques écoresponsables. Musée et écologie dresse le panorama des initiatives d’une communauté engagée en faveur d’un musée sobre et citoyen et offre des clés conceptuelles et pratiques pour une écoconception du musée
Downlink optimization for direct-to-satellite IoT with LEO satellites and LoRaWAN
No full textInternational audiencenetworks a b s t r a c t Direct-to-satellite communication systems for the Internet of Things, particularly those based on low-Earth-orbit satellite constellations, are emerging as a transformative solution to achieve global connectivity. However, ensuring efficient and reliable downlink communication from satellites to ground-based IoT devices remains a significant challenge due to intermittent satellite visibility, short contact durations, limited bandwidth, device energy constraints, and high network density. Unlike prior studies that primarily focus on uplink optimization, this work proposes a downlink-aware optimization framework that integrates satellite dynamics, LoRaWAN MAC constraints, and energy-aware scheduling. The framework accounts for physical-layer limitations, satellite visibility modeling, time-slot feasibility, and realistic system parameters consistent with LEO satellite operations. Simulations demonstrate that the proposed downlink-aware optimization framework improves the packet delivery ratio from 0.41 (achieved under random scheduling) to 0.96, while reducing the average energy consumption per successful transmission by approximately 55 %. These results highlight the efficiency of the proposed NSGA-II-based scheduling approach and provide an initial pattern that points toward potential scalability, compared to conventional non-optimized methods, demonstrating its promise for next-generation satellite-enabled IoT networks.</div
Characterising knots by their branched coverings
No full textThese are the notes for a mini-course on the problem of determining knots by means of their cyclic branched coverings given at the Workshop on Branched Covers held at IMUS in Seville from November 17 to 21, 2025.</div
The unexpected dewetting during growth of silicene flakes with dendritic pyramids
No full textInternational audienceSilicene growth on graphene has emerged as a novel method for fabricating silicon-based van der Waals heterostructures. However, the silicene flakes produced in this manner are the result of an exotic growth mode characterized by metastable nanostructures with varying degrees of deviation from equilibrium, with large two-dimensional flakes surrounded by a rim that coexist with small 3D islands, and, at large deposits, thick dendritic pyramids separated by a denuded zone. In order to rationalize and control this growth, a model is derived that revisits the dewetting thermodynamics and considers generally ignored adsorption and step-edge energies. The model is investigated using kinetic Monte-Carlo simulations and mean-field rate equations, and implemented by close inspection of microscopy images. This model perfectly reproduces the experimental outcomes, unveiling an anomalous growth mode, and provides guidelines on experimental conditions for high-quality silicene growth.</div