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Physics-Informed Neural Estimation of State and Unknown Input inAutonomic Cardiac Dynamics with Left-Invertibility Constraints
No full textInternational audienceUnderstanding brain–heart interaction (BHI) requires models that capture how the central nervous system and the cardiovascular system co-regulate each other under internal and external stressors to preserve homeostasis and give rise to macroscopic physiological states such as sleep, arousal, or vigilance. At the core of this loop are interoceptive variables, defined as latent autonomic control signals that encode the body’s internal state and drive cardiac adjustments; however, these variables are not directly measurable. Recovering these hidden drives from peripheral cardiac signals requires taking into account nonlinear dynamics and physiological confounds, as well as limited measurement data. This work proposes a physics-informed neural estimator for simultaneous state estimation and reconstruction of unknown control inputs in a nonlinear, coupled model of autonomic cardiac regulation. The estimator enforces model-based constraints along with data-driven regularization, and embeds structural identifiability conditions derived from the system itself, yielding guarantees without prescribing a dynamical prior for the unknown input. Validation of stressevokedcardiac recordings shows the accurate recovery of heart rate, along with estimates of state (being blood pressure) and the unknown control input (being the blood-pressure setpoint); hence, enabling physiology-consistent, left-invertible inferenceof interoceptive autonomic dynamics
New insight on the properties of the superconducting iron spin ladder BaFe<sub>2</sub>S<sub>3</sub>
No full textInternational audienceBaFe2S3 and BaFe2Se3 are the only two quasi-one-dimensional iron-based compounds that become superconductors under pressure. Interestingly, these two compounds exhibit different symmetries and properties. While more detailed and recent studies on BaFe2S3 using single crystals have advanced the field towards a more universal description of this family, such a study is still lacking for the compound BaFe2S3 . Here, we present a detailed study of the crystalline and magnetic structures performed on single crystals using X-ray and neutron diffraction. We demonstrate a polar structure at room temperature within the Cm2m followed by a structural transition at TS = 130 K to the polar Pb21m space group, space group. This space group remains unchanged across the magnetic transition at TN = 95 K, revealing multiferroic characteristics with a weak magnetoelastic coupling. The determined magnetic structure is monoclinic (Pam ), with non-collinear Fe magnetic moments, tilted from the rung axis. This reexamination of the temperature-dependent properties of BaFe2S3 provides new insights into the physics of this system from multiple key perspectives
Measurements of the proton-induced reaction 155Gd(p,n)155Tb at energies between 7 and 26 MeV with highly-enriched 155Gd targets
No full textInternational audienceBackground The need for new medical radionuclides continues to grow as treatments become more personalised. Terbium-155, a gamma emitter, is an appealing isotope that could be used for Single Photon Emission Computed Tomography (SPECT). Since it belongs to the Terbium quadruplet, it could be coupled with other Tb isotopes to form a theranostic pair. However, it is currently not accessible in sufficient quantities with an acceptable radionuclidic purity. An investigation of the excitation function of the nuclear reaction 155Gd(p,n) over an energy range accessible to most medical cyclotrons is relevant for optimizing 155Tb production. For the first time, we report the measurements of this reaction with highly enriched (> 99.0%) 155Gd targets. Methods Pure 155Gd targets, with isotopic enrichment better than 99%, have been produced using the highperformance electromagnetic separator SIDONIE at IJClab, Orsay, France. Proton activation measurements have been performed using two different cyclotrons and a linear accelerator (linac). Results The full excitation function of 155Gd(p,n)155Tb has been obtained over the 7-26 MeV range. All 18 measured cross-sections are consistent with each other, without the need of any renormalization. All the obtained data were compared with already published results and clearly show a maximum production at 11 MeV, with a cross section of 500 mb. Conclusion Experimental data indicates excitation function maximum around 11 MeV for the studied energy range, and cross sections are greater when target purity in 155Gd is higher
Investigations of raster layup effect on mechanical and fracture properties of material extruded ABS samples under biaxial loadings
No full textInternational audienceThe mechanical properties of 3D printed parts are influenced by the parameters used during the manufacturing process. Among them, the raster orientation plays an important role. In this study, biaxial tensile tests coupled with digital image correlation are used to evaluate the effect of raster orientation on the deformation and failure mechanisms of acrylonitrile butadiene styrene samples. It is shown that the local deformation mechanisms are mainly driven by the raster orientation after the crack initiation at sample corners. The kinematic fields evidence that the local deformation mechanisms are related to the mesostructures induced by the fabrication process. A comparative analysis of the different printing orientations (0°/90°, ±45°, 15°/105°, and 30°/120°) reveals that the orthotropic architecture strongly influences the mechanical response and failure mechanisms. This study points out the necessity of improving the filament junctions of polymer parts obtained by fused filament fabrication
Measurement of the Z production cross section and search for anomalous neutral triple gauge couplings in pp collisions at = 13 TeV
No full textInternational audienceA measurement of the fiducial cross section of the associated production of a Z boson and a high- photon, where the Z decays to two neutrinos, and a search for anomalous triple gauge couplings are reported. The results are based on data collected by the CMS experiment at the LHC in proton-proton collisions at = 13 TeV during 20162018, corresponding to an integrated luminosity of 138 fb. The fiducial Z cross section, where a photon with a greater than 225 GeV is produced in association with a Z, and the Z decays to a pair (Z()), is measured to be 23.3 fb, in agreement, within uncertainties, with the standard model prediction. The differential cross section as a function of the photon has been measured and compared with standard model predictions computed at next-to-leading and at next-to-next-to-leading order in perturbative quantum chromodynamics. Constraints have been placed on the presence of anomalous couplings that affect the ZZ and Z vertex using the spectrum of the photons. The observed 95% confidence level intervals for -conserving and are determined to be (3.4, 3.5) 10 and (6.8, 6.8) 10, and for and they are (2.2, 2.2) 10 and (4.1, 4.2) 10, respectively. These are the strictest limits to date on , and
Les interfaces graphiques pour la modélisation hydrologique. De la préparation des données à la prévision des débits
No full textInternational audienceFor nearly ten years, the Hydrology team at the HYCAR research unit (Antony) has been designing and developing graphical interfaces dedicated to hydrological modeling. These tools are intended to facilitate the entire modeling process — from the preparation and validation of input data to the visualization and interpretation of results, including hydrological forecasting. Designed both as educational resources and decision-support tools, these interfaces help improve understanding and interpretation of streamflow simulations across watersheds.Depuis près de dix ans, l’équipe Hydrologie des bassins versants de l’U.R. HYCAR (Antony) conçoit et développe des interfaces graphiques dédiées à la modélisation hydrologique. Ces outils visent à faciliter l’ensemble du processus de modélisation, depuis la préparation et la validation des données d’entrée jusqu’à la visualisation et l’interprétation des résultats, notamment des prévision hydrologiques. Pensées comme supports pédagogiques et des outils d’aide à la décision, ces interfaces contribuent à améliorer la compréhension l'interprétation des simulations de débits sur les bassins versants
Comparison of the trace and major elements distribution in river waters from large-scale watersheds of the Tibetan Plateau
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Investigating post-wildfire effects in contrasted Mediterranean ecosystems
No full textInternational audiencePurpose: This review examines the effects of wildfires in Mediterranean and contrasted ecosystems (e.g. in terms of topography, vegetation cover, wildfire history) through the prism of ecosystem components. This approach considers the multiple components of the ecosystem, including soils and sediments, water, and biota, as well as external stressors such as chemical contaminants, to assess the multiple impacts of wildfires. These impacts, which spread from upper to lower catchment areas, affect all ecosystem components, physical, biological, and functional, in a cumulative process along the entire trajectory. Their extent and nature depend on both the intrinsic characteristics of the environment, such as topography, vegetation cover, soil type, and hydrological connectivity, and the characteristics of the wildfire, including its intensity, severity, extent, and frequency. By investigating erosion processes, biodiversity changes and their impacts via environmental DNA analysis, the redistribution of fire retardants, and sediment transport, the aim is to provide a comprehensive understanding of wildfire effects. The main objective of the current review is to synthesize existing knowledge and to identify critical gaps in our understanding of the interactions between these factors, including wildfire, biodiversity, erosion, and contaminants. Methods: Relevant journal articles were extracted from the Clarivate Web of Science database as of September 9, 2025. A total of 161 publications were analyzed, and their findings were categorized into three thematic axes related to wildfire effects: post-wildfire erosion and sediment dynamics, biodiversity assessment using environmental DNA (eDNA), and the transfer of contaminants such as flame retardants and Polycyclic Aromatic Hydrocarbons (PAHs). Results and Conclusion: The results highlighted the complex relationships between wildfire-induced erosion, sediment dynamics, biodiversity and the effects of contaminant transfers in impacted areas. Accordingly, the need to implement comprehensive long-term research, conducted over more than two decades and conducted at integrative spatial scales (e.g. at the catchment level), to improve our understanding of ecological connectivity, sediment transport dynamics, and the cumulative effects of wildfires is demonstrated
Analysis of French Spirit Barrels (Oak Wood) Metabolites by LDI-MSI
No full textInternational audienceInsight into the composition, migration, degradation, and external interactions of compounds within oak is fundamental to the wine and spirits industry, given their direct impact on the organoleptic properties of aged spirits. The characterization of oak extracts has traditionally relied on HPLC-MS and GC-MS. However, (MA)LDI-MS imaging is a technique that could give newinformation about wood metabolite distribution.IntroductionCognac barrels are primarily made of oak wood (Quercus spp.), a genus within the Fagaceae family that includes approximately 500 species. Understanding the composition, migration, degradation, and external interactions of compounds in oak is essential for the wine and spirits industry, as these processes directly influence the organoleptic properties of aged spirits. Oak extracts have been widely studied using techniques such as HPLC-MS1 and GC-MS2, while more recent work has used TOF-SIMS3 to analyze small surface regions of barrel staves. Although TOFSIMS offers high spatial resolution, it is limited in mass range and mass resolution.(1) Glabasnia, A.; Hofmann, T. Identification and Sensory Evaluation of Dehydro- and Deoxyellagitannins Formed upon Toasting of Oak Wood (Quercus alba L.). J. Agric. Food Chem. 2007, 55 (10), 4109–4118. DOI: 10.1021/jf070151m.(2) Flamini, R.; Panighel, A.; Marchi, F. de. Mass spectrometry in the study of wood compounds released in the barrel‐aged wine and spirits. Mass Spectrometry Reviews 2023, 42 (4), 1174–1220. DOI: 10.1002/mas.21754.(3) Cournut, A.; Vanbellingen, Q. P.; Demaye, A.; Ochs, M.; Römpp, A.; Touboul, D.; Eparvier, V.; Brunelle, A. Multimodal Analysis of Oak Wood Metabolites for a Comprehensive Understanding of the Aging Process in Typical French Spirit Barrels. Journal of mass spectrometry : JMS 2025, 60 (9), e5170. DOI: 10.1002/jms.5170.MethodsWe analyzed the transversal surface of oak staves, from the inner to the outer barrel wall, enabling the observation of gradual chemical changes across the entire wood section. We compared freshly cut, freshly toasted, and historical (100-year-old) staves. For our studies, we utilized a MALDI source equipped with autofocus and large sample holders, allowing the direct analysis of intact samples (2.0×0.3×0.5 cm).ResultsPreliminary results revealed a decrease in ion signal intensity in the inner and/or outer regions of the barrel. Several experimental strategies (including changes in acquisition direction, the use of internal standards, and optimization of instrumental parameters) were tested to determine whether this effect reflected true chemical variation or methodological limitations. Colocalization analysis using MZmine proved particularly effective for identifying spatially correlated compounds. Notably, compounds such as cyclotene, methylbutyric acid, and 1-(2-furanyl)ethanone seem to have higher intensities in toasted regions, consistent with previous reports based on barrel wood extracts. Additionally, previously unreported signals were observed in localized wood areas. Several compounds were tentatively identified using data-dependent acquisition (DDA) andMS/MS library matching.ConclusionAlthough this work at a preliminary stage, it demonstrates the feasibility of analyzing intact barrel staves by MALDI-MSI and establishes methodological strategies that will support comprehensive future studies of compound behavior in cognac barrels
Nighttime Contrail Characterization from Multisource Lidar and Meteorological Observations
No full textInternational audienceThe present study provides a comprehensive nighttime contrail characterization combining Raman lidar, ADS-B flight data, and ECMWF ERA5 reanalysis over southern France. Observations of different case studies of contrail formation and development throughout their lifetimes provide valuable insights into the contrails’ morphological, microphysical, and optical properties, persistence, and dispersion. We present a multisource methodology to detect and characterize nighttime aircraft contrails over the Observatory of Haute-Provence (OHP) in France. The determination of contrail signatures was performed by applying sensitivity analyses by spatiotemporal thresholding and clustering for contrail detection. Optimizing the thresholds permits the improvement of contrail detection and the reduction of unnecessary noise. The optimal combination of these thresholds, which best reduces false positives and negatives, was SR = 2.1, time = 7.2 min, and altitude = 0.3 km. Subsequent merging of the spots produces persistent contrail signatures at altitudes of 8.7–10.3 km, with thicknesses of 0.1–1.1 km, widths of 2–2.8 km, and optical depths of 0.05–0.40. Contrail optical depth correlates significantly with geometrical thickness and width, which highlights the interplay between contrail morphology and ambient thermodynamic conditions. Our methodology demonstrates the value of combining lidar and flight data for contrail characterization using lidar measurements, flight data, and meteorological information