Portail HAL UNIV-RENNES
Not a member yet
180610 research outputs found
Sort by
Motor complications and postural abnormalities interplay in Parkinson's disease
No full textInternational audienceBackground: Postural abnormalities (PA) and motor complications (MCs, including motor fluctuations - MFs- and levodopa-induced dyskinesia - LIDs) are hallmark of Parkinson's disease (PD) progression, yet their relationship remains poorly understood.Objective: To investigate the association between PA and MCs, motor symptoms, and non-motor symptoms (NMS) in patients with PD, and to assess whether PA influences the development of MCs over time.Methods: Data of the prospective NS-Park cohort (27 French PD Expert Centers) were analysed. PA was defined by a score ≥2 on item 3.13 of the MDS-UPDRS-III. Associations between PA and MCs, as well as with other motor symptoms and NMS, were assessed using logistic regression models. We used interval censoring survival models to assess the associations between PA at inclusion and the incidence of MCs. Analyses were adjusted for sex, age, disease duration, dopaminergic dose, and disease severity.Results: Among 13,037 included PD patients (58.7 % male, median age at diagnosis 61 years), 724 (5.6 %) presented with PA. Patients with PA had longer disease duration, higher disease severity, and higher dopaminergic treatment. PA exhibited a higher prevalence of troublesome MFs (OR: 5.96; 95 % CI: 4.25-8.32) and LIDs (OR: 2.81; 95 % CI: 1.79-4.30), while associations with milder MCs were inconsistent. However, PA was not significantly associated with the development of MCs during follow-up.Conclusions: PA are associated with more frequent severe MCs, and a higher burden of motor and NMS, making patient care particularly challenging
Decisiveness for Countable MDPs and Insights for NPLCSs and POMDPs
No full textInternational audienceMarkov chains and Markov decision processes (MDPs) are well-established probabilistic models. While finite Markov models are well-understood, analyzing their infinite counterparts remains a significant challenge. Decisiveness has proven to be an elegant property for countable Markov chains: it is general enough to be satisfied by several natural classes of countable Markov chains, and it is a sufficient condition for simple qualitative and approximate quantitative model-checking algorithms to exist.In contrast, existing works on the formal analysis of countable MDPs usually rely on ad hoc techniques tailored to specific classes. We provide here a general framework to analyze countable MDPs by extending the notion of decisiveness. Compared to Markov chains, MDPs exhibit extra non-determinism that can be resolved in an adversarial or cooperative way, leading to multiple natural notions of decisiveness. We show that these notions enable the approximation of reachability and safety probabilities in countable MDPs using simple model-checking procedures.We then instantiate our generic approach to two concrete classes of models inducing countable MDPs: non-deterministic probabilistic lossy channel systems and partially observable MDPs. This leads to an algorithm to approximately compute safety probabilities in each of these classes
Direction-of-Arrival Estimation of Coherent Sources with Leaky-Wave Antennas using Spatially Filtered Interpolation
No full textInternational audienceWith their frequency-beam scanning behavior, leaky-wave antennas (LWAs) are promisingsolutions to develop accurate and cost-effective direction-of-arrival (DoA) estimationsystems. However, DoA estimators such as MUSIC face challenges with coherent sourcesdue to the non-Vandermonde LWA steering matrix. Leveraging the unique radiation propertiesof LWAs, this paper first divides the entire field of view into several angular sectors,and then introduces a robust and accurate sectorized spatially-filtered interpolation (SFI)method to transform the LWA steering matrix into a Vandermonde matrix in each sectorwhile minimizing the issue of out-of-sector interference. The proposed method allowsthus the estimation of DoAs of coherent sources with LWAs. The simulation results showthat the DoAs of multiple coherent sources across the entire field-of-view, regardless theirangular sector, can be correctly estimated. The performance of the proposed method isshown be close to the Cramér-Rao Bound
Combien de balais pour une sorcière ?: Approche anthropo-analytique de la sorcierisation des femmes vieillissantes dans le contexte social contemporain
No full textInternational audienc
Pottery chaînes opératoires at Incoronata. Local/regional production and imports (9th to 7th centuries BC)
No full textInternational audienc
Capturing the positive effects of brain drain through return migration policies: An analysis of the 1980-2022 Moroccan experience
No full textNational audienceThe emigration of highly educated and skilled individuals from low- and middle- to high-income countries has often been synonymous with human capital losses for the countries of origin, a phenomenon known as "brain drain" (Bhagwati and Hamada, 1974). However, under some conditions, these losses can be offset by human capital formation in the source countries precisely due to emigration. In this case, one talks about "beneficial brain drain" and this phenomenon has been coined "brain gain" (Stark et al., 1997, 1998). Using data on the Kingdom of Morocco covering the 1980-2022 period, we investigate the extent to which the government drew economic benefits from an important population of Moroccans living abroad by implementing return migration policies. More specifically, we explore the effects of measures targeting the Moroccan diasporas and their contributions to the Kingdom's economy on (i) the attractiveness of the Kingdom for foreign investors; (ii) the quality and capacity of the country's commercial air and maritime transport infrastructure; and (iii) the level of modernization of its public administration.The data analysis shows that these measures had a positive impact on each of these key dimensions of development, suggesting that this type of policies can be effective in capturing some of the "brain gain" effects that have been highlighted in the empirical literature on the relationship between emigration and development in developing countries (Beine et al., 2001, 2008; Batista et al., 2025)
Proches et lointains, dans l’espace et dans le temps : l’imagerie et l’idéologie des céramistes égéens installés en Italie méridionale au VII siècle avant J.-Chr.,
No full textInternational audienc
OMP multidimensionnel déplié sous contraintes physiques pour les systèmes MIMO à grande échelle
No full textSparse recovery methods are essential for channel estimation and localization in modern communication systems, but their reliability relies on accurate physical models, which are rarely perfectly known. Their computational complexity also grows rapidly with the dictionary dimensions in large MIMO systems. In this paper, we propose MOMPnet, a novel unfolded sparse recovery framework that addresses both the reliability and complexity challenges of traditional methods. By integrating deep unfolding with data-driven dictionary learning, MOMPnet mitigates hardware impairments while preserving interpretability. Instead of a single large dictionary, multiple smaller, independent dictionaries are employed, enabling a low-complexity multidimensional Orthogonal Matching Pursuit algorithm. The proposed unfolded network is evaluated on realistic channel data against multiple baselines, demonstrating its strong performance and potential
Exciton trapping with a twist
No full textInternational audienceIn electron donor–acceptor (D–A) molecules, the relative orientation of constituents has a dramatic influence over their performance. However, the D and A subunits are generally composed of planar aromatic backbones, and the effect of curvature is rarely explored. Here, we investigate how the twist of the aromatic core of a symmetric double-branched D–π–A molecule affects the nature and dynamics of its lower singlet excited state. We show that the twisting of the central donor not only affects the chiroptical properties, and increases the triplet yield, but also facilitates excited-state symmetry breaking (ESSB) and the trapping of the exciton on one D–π–A branch of the molecule. This enhancement is attributed to the decrease in the interbranch coupling upon distortion. Because of this, the loss of the coupling upon ESSB requires a smaller gain in solvation energy to be compensated for and, thus, exciton trapping occurs in a less polar solvent. Consequently, distortion can be viewed as an additional tuning knob for controlling the localisation of electronic excitation in large conjugated systems