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Mapping Postictal Aphasia through Signal Complexity: A Stereo‐Electroencephalography Study
No full textInternational audienceObjective:The postictal period provides an opportunity to investigate the pathophysiology underlying aphasia and recovery following epileptic seizures. This study examines postictal aphasia in stereo-electroencephalography (SEEG)explored patients to identify brain regions associated with task-specific language deficits using signal complexity analysis. Methods: We evaluated video-SEEG-recorded focal seizures with and without postictal aphasia in patients with SEEGconfirmed hemispheric language dominance. SEEG traces were analyzed using permutation entropy (PE), with the postictal period quantified by a PE-based metric, the Postictal Alteration Time (PAT). Brain region PAT was correlated with language function recovery (eg, repetition). Electro-clinical recuperation was also assessed within the dorsalventral language stream framework. Additionally, a bedside testing battery was developed to evaluate postictal aphasia severity and task-specific deficits. Results: A total of 322 seizures from 98 patients were analyzed. Seizures with postictal aphasia had longer PAT than those without. Task-specific language recovery correlated with regional PAT (eg, namingmiddle temporal gyrus). Moreover, the dorsal stream recovered faster than the ventral stream. Additionally, the Postictal Aphasia Scale (PAS) was developed, evaluating naming, reading, repetition, and comprehension (verbal and written) and automatic speech. Higher PAS scores (indicating milder deficits) correlated with faster regional complexity recovery. At 5 and 10 minutes postictally, PAS revealed a global aphasia pattern, with comprehension deficits gradually resolving. By 15 minutes, aphasia was primarily production-related, particularly affecting naming. Interpretation: This study provides new insights into the pathophysiology of postictal aphasia and introduces PAS as a tool for assessing postictal aphasia severity and domain-specific deficits, aiding surgical planning and rehabilitation.</div
Enhanced CuO Thin Film Growth via an Optimized Aerosol Droplet Method: Thermal Effects and Structural Evaluation
No full textInternational audienceThe scalable production of high‐quality copper oxide (CuO) thin films remains challenging for semiconductor and gas sensor applications. This study presents an optimized aerosol droplet method (AMD) that enhances film uniformity and crystallinity through improved substrate positioning and aerosol dynamics. Compared to conventional aerosol chemical vapor deposition (ACVD), the modified AMD configuration extends droplet trajectories, reducing thickness variation by 30–50% and enhancing structural ordering. Systematic analysis of substrate temperature effects (100–300°C) shows higher temperatures decrease film thickness and microstrain while increasing crystallite size and improving optical properties. X‐ray diffraction (XRD) confirms phase‐pure monoclinic CuO with enhanced crystallinity, and scanning electron microscopy (SEM) demonstrates temperature‐controlled morphological evolution. Energy‐dispersive X‐ray spectroscopy (EDX) confirms uniform elemental distribution. Raman and photoluminescence (PL) spectroscopy reveal temperature‐dependent defect states and bandgap narrowing from 1.6 to 1.5 eV, accompanied by variations in Urbach energy and dielectric constants. The results demonstrate AMD as an efficient, scalable approach for fabricating high‐performance CuO thin films with tunable structural and optoelectronic properties, making them ideal for advanced gas sensing and optoelectronic devices
Nanoplasmonic sensing on size-selected Pt10 clusters to study CO and oxygen adsorption and CO oxidation
No full textInternational audienceWe studied the adsorption of CO and oxygen and CO oxidation on size-selected Pt10 clusters using indirect nanoplasmonic sensing (INPS) in the pressure range of 10-2 - 10-1 Torr at T = 418 K [1]. CO adsorption was reversible, inducing a blue-shift in the localised surface plasmon resonance (LSPR) response, regardless of the initial CO pressure. We observed a plateau at approximately Δλ = − 0.1 nm at PCO at PCO > 2 × 10-2 Torr, indicating saturation of CO adsorption on Pt10 clusters. Oxygen clearly induces both chemisorption and oxidation of Pt10 clusters until a regime is reached where Δλmax remains positive and constant, showing that the Pt10 clusters are completely oxidised. CO oxidation at different molar fractions is also followed by INPS. All results are discussed in relation to our previous works on 3 nm Pt nanocubes [2]. The study demonstrates the suitability of INPS towards understanding the nature and function of matter in the largely unexplored subnanometer size regime, where properties can often dramatically change when altering the particle size by a single atom.1. B. Demirdjian, M. Vaidulych, I. Ozerov, F. Bedu, S. Vajda, C. R. Henry, Nanoscale 16 (2024) 209682. B. Demirdjian, I. Ozerov, F. Bedu, A. Ranguis and C. R. Henry, ACS Omega 6 (2021) 1339
On a finite-volume approximation of a diffusion-convection equation with a multiplicative stochastic force
No full textInternational audienceThe aim of this paper is to address the convergence analysis of a finite-volume scheme for the approximation of a stochastic non-linear parabolic problem set in a bounded domain of R 2 and under homogeneous Neumann boundary conditions. The considered discretization is semi-implicit in time and TPFA in space. By adapting well-known methods for the time-discretization of stochastic PDEs, one shows that the associated finite-volume approximation converges towards the unique variational solution of the continuous problem strongly in L 2 (Ω; L 2 (0, T ; L 2 (Λ)))
Time-resolved absorption of six chemical species with MAROON-X points to a strong drag in the ultra-hot Jupiter TOI-1518 b
No full textInternational audienceContext. Wind dynamics play a pivotal role in governing transport processes within planetary atmospheres, influencing atmospheric chemistry, cloud formation, and the overall energy budget. Understanding the strength and patterns of winds is crucial for comprehensive insights into the physics of ultra-hot-Jupiter atmospheres. Current research has proposed different mechanisms that limit wind speeds in these atmospheres.Aims. This study focuses on unraveling the wind dynamics and the chemical composition in the atmosphere of the ultra-hot Jupiter TOI-1518 b.Methods. Two transit observations using the high-resolution (Rλ ∼ 85 000) optical (spectral coverage between 490 and 920 nm) spectrograph MAROON-X were obtained and analyzed to explore the chemical composition and wind dynamics using the cross-correlation techniques, global circulation models (GCMs), and atmospheric retrieval.Results. We report the detection of 14 species in the atmosphere of TOI-1518 b through cross-correlation analysis. VO was detected only with the new HyVO line list, whereas TiO was not detected. Additionally, we measured the time-varying cross-correlation trails for six different species, compared them with predictions from GCMs, and conclude that a strong drag is slowing the winds in TOI-1518 b’s atmosphere (τdrag ≈ 103−104 s). We find that the trails are species dependent. Fe+ favors stronger drag than Fe, which we interpret as a sign of magnetic effects being responsible for the observed strong drag. Furthermore, we show that Ca+ probes layers above the Roche lobe, leading to a qualitatively different trail than the other species. Finally, We used a retrieval analysis to further characterize the abundances of the different species detected. Our analysis is refined thanks to the updated planetary mass of 1.83 ± 0.47 MJup we derived from new Sophie radial-velocity observations. We measure an abundance of Fe of log10 Fe = −4.88−0.76+0.63 corresponding to 0.07 to 1.62 solar enrichment. For the other elements, the retrievals appear to be biased, probably due to the different Kp/Vsys shifts between Fe and the other elements, which we demonstrate for the case of VO
A new quasi-asymptotic-preserving mixed formulation with discontinuous Galerkin method for highly anisotropic diffusion equations
No full textThe paper is dedicated to the resolution of highly anisotropic diffusion equations that could be singularly perturbed/ill-conditioned as tends near to zero ( being a positive small parameter characterizing the magnitude of the anisotropy) by a discontinuous Galerkin (DG) method. This work introduces a new asymptotic-preserving-like scheme, called quasi-asymptotic-preserving (QAP), in a mixed formulation and inspired by the asymptotic-preserving macro-micro decomposition. The proposed DG approximation takes root in the Symmetric Weighted Interior Penalty (SWIP) method which was designed to cope with anisotropic diffusivity, and the Local Discontinuous Galerkin (LDG) method in the context of mixed DG methods. The paper shows the problem is well-posed for any \varepsilon>0 regardless of anisotropy topology. Furthermore, for approximation polynomials of degree , the theoretical convergence of the scheme is of order for smooth data whereas numerical tests show an optimal order of . In addition, numerical tests show that, although the condition number of the discrete system remains proportional to , the quality of the numerical solution is not affected in this new formulation
Ce que les enjeux environnementaux font à nos pratiques de coopération
No full textNuméro coordonné par Lucie Bruis-Gervasone et Anne-Gaëlle BeurierInternational audienc
Les saisonniers marocains placés, déplacés et irremplacés dans l’agriculture labellisée corse
No full textInternational audienceAvec une lecture pluridisciplinaire, différentes méthodes d’enquête et des données non publiques, cet article examine les motifs du recrutement des travailleurs étrangers dans l’agrumiculture corse, depuis 2000 et lors de l’épidémie de la Covid-19. La Plaine orientale corse, connue pour sa culture labellisée de la clémentine, accueille chaque année des saisonniers marocains, une main-d’œuvre qualifiée indispensable à cette économie. La Covid a précisément donné lieu à des dérogations exceptionnelles afin d’assurer ce recrutement. Mais les évolutions agricoles depuis 1950 montrent le caractère banal de cette exceptionnalité dans un contexte agricole départemental habitué aux dérogations, et le poids relatif de l’argument des compétences dans les préférences de recrutement de travailleurs destinés à une production labellisée. En effet, le lien au passé colonial intervient dans l’établissement de ces dérogations, pour adapter aux besoins locaux, et selon des réseaux professionnels historiques, l’embauche des Marocains dans cette filière d’excellence
Deciphering the environmental background of a roman brick and tile works in Mariana (Pruniccia, Lucciana, Corsica) with geomorphology, palaeoentomology and archaeobotany
No full textInternational audienceCombined evidence from insect and plant remains was recovered from separate areas of a Roman brick works at the site of Pruniccia (Corsica), in an area adjacent to the Roman town of Mariana. Their interpretation helps us to reconstruct the specific activities undertaken and broaden our understanding of how human activities affected the composition of sub-fossil plant and insect assemblages. After including geomorphological evidence, we also assess the local environmental conditions of the site. In well PT20019, an unexpected abundance and diversity of insects characteristic of aquatic habitats contrasts with results from fruits and seeds, prompting questions on the taphonomic processes involved. The relatively small number of woody taxa identified from charcoal in kiln FR200002 and the related working area (FS20088) includes trees and shrubs that would have been easily accessible nearby. The detection of insect damage in Alnus wood is consistent with the repeated finds of insects which attack wood. This suggests that firewood may have been collected in advance and stored until needed. More generally, our work illustrates the variety of habitats in the area around the Roman town and helps us compensate for the shortage of palaeoenvironmental information available locally up to now