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Signal Processing and Machine Learning Algorithms for Precise Timing with PICOSEC Micromegas Detectors
No full textInternational audienceHigh particle rates in current and future experiments make pile-up phenomena a critical issue for extracting useful information. In this context, timing can be important as the 4 dimension parameter for triggering or event reconstruction. The PICOSEC-Micromegas detector has been shown to offer precise timing of the order of tens of ps. In this work, novel signal processing algorithms are being developed and evaluated to demonstrate the technology's ability for online precise timing. We propose, an algorithm based on Artificial Neural Networks (ANN). This algorithm uses a model to train the ANN. The performance of the different algorithms is evaluated using experimental data, resulting in a timing resolution of 18.3 0.6 ps, comparable to the standard analysis based on the Constant Fraction Discrimination technique. Additionally, an alternative algorithm using the charge of the pulse exceeding a threshold as a parameter to correct for systematic effects is reported
First Displaced Vertex Search for Electroproduced Dark-Sector Strongly Interacting Massive Particles by the HPS Experiment
No full textInternational audienceThe Heavy Photon Search experiment (HPS) is a fixed-target, electron beam experiment designed to search for mass resonances and displaced decays using a forward acceptance spectrometer. This article details the search for naturally long-lived ``dark" vector mesons () arising from a dark sector of beyond-Standard-Model SIMP, characterized by a QCD-like symmetry and coupled to the Standard Model photon via a new gauge interaction mediated by the ``heavy photon", or . The results are based on an integrated luminosity of \SI{10608}{nb^{-1}} collected during the 2016 HPS Engineering Run. The displaced vertex search for in the invariant mass range 39-179 MeV showed no statistically significant evidence for signal above the QED background
Business strategies for sustainable meat consumption: multistage investigation into profiling environmentally conscious consumer segments
No full textFNEGE 3, ABS 3International audienceThe market for sustainable meats (SMs) is now in its initial phases of developing into a commercial enterprise. To ensure the success of sustainable alternative meats, it is necessary to have a comprehensive understanding of the consumer motivations, barriers and perceived values associated with these meats. Both the Theory of Consumption Values (TCV) and the Behavioural Reasoning Theory (BRT) were used in this research project to identify and characterise various potential consumer segments that exist within the SMs market. Using the mall intercept technique, data were collected from four different cities. Study 1 comprised 458 participants, whereas Study 2 included 463. Consumers were divided into 6 cluster groups using sequential cluster analysis, considering a variety of consumption values as well as reasons for and against adopting SMs. The findings indicate that the consumers in the different clusters are distinguished by distinct combinations of perceived consumption values and reasons for or against the consumption of SMs. The findings of the study have significant implications for producers, marketers and advocates for sustainable meats, as they can help them build product, marketing and positioning strategies that are specifically targeted to each consumer segment
Test-beam results from MiniCACTUS-v2: A depleted monolithic CMOS timing sensor prototype
No full textInternational audienceMiniCACTUS-v2 is a monolithic sensor prototype designed in LF 150 nm CMOS process for time tagging of individual Minimum Ionizing Particles with an accuracy better than 100 ps. The sensing element is a deep n-well/p-substrate diode without internal amplification. To minimize detector capacitances, the analog front-ends and the discriminators for each pixel have been implemented outside the pixel, at the column level. After fabrication, the sensors have been thinned to 150 microns, 175 microns and 200 microns and then post-processed for backside biasing. The breakdown voltages measured on these sensors are higher than 500 V, ensuring the complete depletion of the charge collection volume. In this paper, we will focus on the time resolution measurements from a test-beam campaign conducted in July 2025 at SPS-CERN. During this period, several pixels from the 3 different sensor thicknesses have been tested at different bias voltages. The best time resolution measured is 48.88 ps on a 0.5 mm x 0.5 mm pixel from a 175 microns-thick sensor at 500 V, with nominal settings for the on-chip analog front-end and discriminator
First-in human assessment of the UroActive® electronic Artificial Urinary Sphincter for treating male stress urinary incontinence (SUI)
No full textInternational audiencePurpose:To evaluate the feasibility, safety, and efficacy during the first year of use of the UroActive® device in males with stress urinary incontinence (SUI).Materials and Methods:This prospective, multicenter, single-arm, first-in-human study enrolled six male patients with bothersome SUI unresponsive to conservative or surgical treatments. After UroActive® implantation, follow up was planned for 5 years (post-activation). Study endpoints included successful device activation, revision, and explantation rates. Other endpoints assessed 24 h pad-weight test reduction, pad usage, uroflowmetry, post-void residual urine, patient-reported outcomes (ICIQ-UI SF, EQ-5D, I-QOL, USP). Adverse events were collected throughout the study.Results:All six patients underwent successful implantation and device activation (100%). No explants or revisions were required during the 365 days post-activation. At 365 days post-activation, the pad weight was reduced by ≥50% in all patients and reduced by ≥75% in five (83.3%). Median pad use decreased from 3.7 to 1.0 pads/day. Uroflowmetry remained within acceptable ranges, and post-void residual urine was minimal. Quality of life scores significantly improved across all instruments. Nine device deficiencies were reported, all involving the patient remote control. No unanticipated serious adverse events occurred.Conclusions:In men with SUI, the UroActive® device demonstrates promising feasibility, safety, and functional outcomes during the 365 days post-activation. Patients experienced substantial symptom improvement and high satisfaction, with no surgical revisions. Larger studies with extended follow-up are needed to confirm these findings and assess long-term device performance
Data from long-term experiments in temperate croplands to evaluate soil organic carbon models
No full textInternational audienceSoil organic carbon (SOC) models need independent evaluation against field measurements, but those latter are rarely publicly available and harmonized. In this study, we collected and shared data from 167 agronomic treatments in 34 agronomic long-term experiments (LTEs) located in temperate croplands, allowing the evaluation of several soil organic C models such as RothC, Century, AMG, MIMICS, ICBM, Millenial, and CTOOL. The dataset includes climate data, soil properties, C inputs from crops (n = 4588 records) and organic amendments, irrigation data, monthly soil cover, as well as SOC stock measurements in the topsoil layer (n = 1328 records). Climate, soil moisture, and soil temperature data were extracted from daily climate databases. Carbon inputs from crops were calculated from observed yields and harvest index, with some harvest index values estimated, combined with crop allometric coefficients from the literature. Descriptions of LTE, agronomic treatments, methodological metadata, and a part of the code, accompanies the dataset. The dataset can be reused to evaluate single SOC models, or to evaluate an ensemble of models
The two-step scenario of the Messinian Crisis (Clauzon et al. , 1996): a specification supported by new data
No full textInternational audienceMany papers refer in a revised way to the two-step scenario of the Messinian Crisis conceived by Clauzon et al. (1996). The present paper recalls the basis for the two-step scenario and discrepancies with the later modified version, completed by new data supported by extensive micropaleontological analyses. Our interpretation of the Sicilian Eraclea Minoa section as belonging to a peripheral basin is the centre of the debate. We show the great amplitude of fluvial erosion during the peak of the crisis, which for the Rhône River, exceeded 400 km upstream of the present shoreline. Based on dinoflagellate cysts, we also recall the reasons for supporting the occurrence of three successive Lago Mare episodes of two different origins. The first and third episodes constitute phases of high sea-level exchanges between the Mediterranean and the Paratethys respectively just before the onset of paroxysm and after it. The second episode is due to overflowing Paratethyan waters from the Aegean Basin just before the end of paroxysm. Similarly, the demonstration of the marine reflooding of the Mediterranean Basin prior to the Zanclean is repeated. We emphasize dissimilarity between basins, focussing in particular on those, isolated or perched ones, which were continuously filled by waters during the desiccation phase: western part of the Alboran Sea and southeastern part of the Levantine Basin (marine waters), Apennine Foredeep (fresh waters), and Aegean Basin (brackish waters). The Apennine Foredeep cannot be the reference for the entire Mediterranean with respect to its evolution during the crisis. During the crisis, water exchanges between the Aegean Basin and the Eastern Paratethys (Dacic Basin, Black Sea) were impossible through the Marmara region because of the development of two opposed fluvial networks. Such exchanges existed thanks to a gateway that was probably located within the Balkans. Investigations around the Levantine Basin point to areas submitted to fluvial erosion during the crisis paroxysm and nearby areas, which might have received marine waters from the Red Sea. Much information is still to be discovered and that more progress is still needed in order to fully decipher this outstanding event.De nombreux articles se réfèrent opportunément mais sous une forme revisée au scénario en deux temps de la Crise messinienne de Clauzon et al. (1996). Cet article rappelle les fondements de ce scénario et les dissemblances avec les autres versions, le tout appuyé par de nouvelles données riches en analyses micropaléontologiques. Notre interprétation de la coupe d’Eraclea Minoa (Sicile) comme relevant d’un bassin périphérique est au centre du débat. Nous montrons l’ampleur de l’érosion fluviatile pendant le paroxysme de la crise qui, pour le Rhône, s’est propagée jusqu’à 400 km en amont de l’actuel littoral. Nous rappelons les arguments en faveur de l’existence de trois épisodes Lago Mare distincts chronologiquement et de nature différente mis en evidence par les kystes de dinoflagellés. Les premier et troisième épisodes résultent des phases d’échanges réciproques à haut niveau marin entre Méditerranée et Paratéthys peu avant le déclenchement du paroxysme et après celui-ci. Le second épisode est dû au déversement des eaux paratéthysiennes issues du bassin égéen peu avant la fin du paroxysme. De même, la démonstration du réennoiement du bassin méditerranéen antérieurement au Zancléen est réitérée. L’accent est mis sur la disparité entre bassins, notamment ceux qui sont restés isolés ou perchés et alimentés en eau pendant la phase de dessiccation: partie occidentale de la Mer d’Alboran et partie sud-est du basin levantin (eau marine), avant-fosse apenninique (eau douce), et basin égéen (eau saumâtre). Il est évident que le processus qu’a connu l’avant-fosse apenninique ne peut plus servir de modèle pour l’ensemble du bassin méditerranéen. Les échanges entre bassin égéen et Paratéthys orientale (basin dacique, Mer Noire) ne pouvaient s’effectuer par la région de Marmara, siège pendant la crise de deux réseaux fluviatiles de sens opposé, mais par un corridor probablement intra-balkanique. Les résultats sur le pourtour du bassin levantin laissent entrevoir des secteurs soumis à l’érosion fluviatile lors du paroxysme de la crise à côté de secteurs ayant pu bénéficier d’entrées d’eaux marines de la Mer Rouge. Il reste encore beaucoup à découvrir et à comprendre pour démystifier complètement cet événement hors normes
Dopage des semi-conducteurs à base de silicium en phase diamant hexagonale
No full textThe emergence of hexagonal-diamond (2H) group-IV semiconductors has opened new opportunities for next-generation optoelectronics. Unlike their cubic-diamond (3C) counterparts, whose indirect band gaps limit optical emission, 2H polytypes exhibit distinct electronic structures. In particular, 2H-Si shows a lower indirect band gap of about 0.95 eV, while 2H-Ge behaves as a pseudo-direct-gap semiconductor with a reduced band gap of roughly 0.3 eV. In addition, 2H-Si₁₋ₓGeₓ alloys enable continuous tuning of the band gap from the indirect limit of 2H-Si to the direct regime of 2H-Ge, covering emission wavelengths in the technologically important 1.3-1.8 µm range. Photoluminescence experiments indicate that increasing the Ge content shifts the conduction-band minimum toward the Γ point, leading to a direct and optically allowed transition for Ge concentrations above x = 0.65. These characteristics make hexagonal group-IV materials promising candidates for CMOS-compatible mid-infrared light emitters. However, their full technological potential depends on a detailed understanding of doping mechanisms, impurity thermodynamics, and dopant-defect interactions, which remain largely unexplored. This thesis investigates dopant incorporation, segregation, and interactions with extended defects in hexagonal Si-based semiconductors using density functional theory (DFT). It focuses on three main questions: (i) how the hexagonal crystal phase modifies the structural and electronic properties of conventional p-type and n-type dopants, (ii) how very high boron concentrations affect the structural stability of 2H-SiGe alloys, and (iii) how dopants interact with extended planar defects, particularly the I₃ basal stacking fault. The results show that group-III impurities are generally more stable in the 2H phase, reflecting their preference for local threefold coordination in the hexagonal lattice. Charged acceptors display enhanced stability and slightly shallower charge-transition levels in 2H-Si compared with 3C-Si. Neutral donors do not show a strong phase preference, whereas positively charged donors are more stable in the cubic phase, which leads to shallower donor levels in 3C-Si than in 2H-Si. These trends underline the key role of local bonding and crystal symmetry in determining impurity energetics across different polytypes. For hyperdoping, the calculations demonstrate that extremely high boron concentrations in 2H-SiGe do not destabilize the structure thermodynamically or mechanically. This confirms that hyperdoping is energetically feasible in the hexagonal alloy and suggests the possibility of superconductivity in metastable 2H-SiGe, analogous to what has been observed in heavily doped cubic Si, Ge, and SiGe. The study of dopant interactions with the I₃ basal stacking fault reveals that neutral and negatively charged p-type dopants preferentially occupy lattice sites away from the fault. This preference is much weaker for neutral or positively charged n-type dopants and for isovalent impurities. The segregation behavior results from a combination of electrostatic effects, local strain, and symmetry breaking at the defect, highlighting the strong influence of the local defect environment on dopant stability and distribution in 2H-Si. Overall, this work provides a comprehensive theoretical framework for understanding doping in hexagonal group-IV semiconductors. It supports the rational design of optimized 2H-Si, 2H-Ge, and 2H-SiGe materials and nanostructures, offers insight into their behavior under technologically relevant doping conditions, and helps guide future experimental developments in optoelectronic and quantum-material applications.L'apparition des semi-conducteurs du groupe IV de structure diamant hexagonale (2H) a ouvert de nouvelles perspectives pour l'optoélectronique. Contrairement à leurs homologues de structure diamant cubique (3C), dont les bandes interdites indirectes limitent l'émission optique, les polytypes 2H présentent des structures électroniques distinctes : le 2H-Si possède un gap indirect plus faible (0,95 eV), tandis que le 2H-Ge devient un semi-conducteur à gap pseudo-direct avec une bande interdite réduite (0,3 eV). Les alliages 2H-Si₁₋ₓGeₓ permettent un ajustement continu du gap de bande, passant d'indirect (2H-Si) à direct (2H-Ge), et couvrant des longueurs d'onde d'émission dans la plage pertinente de 1,3 à 1,8 μm. Les études de photoluminescence révèlent que l'augmentation de la teneur en Ge déplace le minimum de la bande de conduction vers le point Γ, conduisant à une transition directe et optiquement permise pour des concentrations en Ge supérieures à 0,65. Ces propriétés positionnent les matériaux du groupe IV en phase 2H comme des candidats prometteurs pour des émetteurs moyen-infrarouges compatibles CMOS. Cependant, leur potentiel technologique nécessite une compréhension plus approfondie des mécanismes de dopage, de la thermodynamique des impuretés et des interactions dopant-défaut. Cette thèse étudie l'incorporation des dopants, leur ségrégation et leurs interactions avec les défauts étendus dans les semi-conducteurs à base de silicium hexagonal en utilisant la théorie de la fonctionnelle de la densité (DFT). Elle aborde trois questions de recherche centrales : (i) comment la phase cristalline hexagonale modifie-t-elle le comportement structural et électronique des impuretés de type p et n conventionnelles ? (ii) comment des concentrations extrêmes de bore affectent-elles la stabilité structurelle des alliages 2H-SiGe ? (iii) comment les dopants interagissent-ils avec les défauts plans étendus, en particulier la faute d'empilement basale omniprésente de type I₃ ? Les résultats montrent que les impuretés du groupe III sont plus stables dans la phase 2H, ce qui reflète leur préférence pour une coordination locale tricoordonnée inhérente au réseau hexagonal. Les accepteurs chargés présentent une stabilité renforcée et des niveaux de transition de charge légèrement moins profonds dans le 2H-Si par rapport au 3C-Si. Les donneurs neutres ne montrent pas de forte préférence de phase, tandis que les donneurs chargés positivement favorisent la structure cubique, conduisant à des niveaux donneurs plus peu profonds dans le 3C-Si que dans le 2H-Si. Ces résultats soulignent le rôle critique du liaisons locales et de la symétrie cristalline dans la détermination de l'énergétique des impuretés entre polytypes. Concernant l'hyperdopage, la thèse montre que des concentrations ultra-élevées de bore dans les alliages 2H-SiGe ne compromettent pas la stabilité structurelle ou thermodynamique, même sous dopage massif. Cela confirme la faisabilité énergétique de l'hyperdopage dans l'alliage hexagonal et suggère un potentiel pour la supraconductivité dans le 2H-SiGe métastable, de manière analogue aux effets observés dans le 3C-Si, le Ge et le SiGe fortement dopés. Enfin, l'analyse des interactions des dopants avec la faute d'empilement basale I₃ montre que les dopants de type p neutres ou négatifs préfèrent des sites éloignés du défaut, contrairement aux dopants de type n et aux impuretés isovalentes. Ce comportement de ségrégation résulte d'une interaction complexe entre l'ionisation électrostatique, les distorsions stériques locales et la rupture de symétrie au niveau du défaut, mettant en évidence l'influence critique de l'environnement local des défauts sur la stabilité et la distribution des dopants dans le 2H-Si. Cette thèse fournit un cadre théorique pour le dopage dans les semi-conducteurs hexagonaux du groupe IV et soutient la conception de matériaux 2H-Si, 2H-Ge et 2H-SiGe optimisés pour l'optoélectronique et les matériaux quantiques
The role of reactive oxygen species and calcium signaling in antiviral defense in Arabidopsis
No full textPlant viruses interfere with host signaling pathways, but it remains unclear how calcium (Ca 2+ ) signaling, reactive oxygen species (ROS), and changes in the plasma membrane interact during viral infection. Here, we investigated how plantago asiatica mosaic virus (PlAMV) modulates host Ca 2+ and ROS-associated signaling in Arabidopsis thaliana. Using live-cell imaging and the R-GECO1.2 Ca 2+ sensor, we observed a rapid increase in cytoplasmic Ca 2+ before the virus was detected, indicating that Ca 2+ release occurs early in infection. Genetic analysis showed that GLR, CPK3, and CNGC, core components of Ca 2+ signaling, limit PlAMV spread between cells, while the usual pattern-triggered immunity (PTI) co-receptors were not needed. This means that Ca 2+based antiviral restriction operates independently of PTI. With the plasma membrane-tethered and cytosolic HyPer7 biosensor, we found that ROS levels were lower inside infection foci in the inoculated leaves, but higher in nearby cells, respectively. The NADPH oxidases RBOHD and RBOHF, which produce ROS, slowed down the local viral propagation. The PM sphingolipid biosynthetic enzyme MOCA1 altered ROS patterns and reduced the virus's spread. Epistasis analysis revealed a functional interaction between RBOHD and MOCA1, suggesting that ROS signaling and plasma membrane sphingolipid homeostasis are interconnected in antiviral defense.Overall, our findings suggest that PlAMV triggers Ca 2+ influx and ROS signaling at the plasma membrane, which induces sphingolipid reorganization and helps restrict the propagation of the virus. This study shows how Ca 2+ , ROS, and membrane sphingolipid signaling work together in plant antiviral immunity and points to possible ways to improve resistance to viruses
Quantum Coherent Transport of 1D Ballistic States in Second-Order Topological Insulator Bi4Br4
No full textMain text and Supplemental materialInternational audienceWe investigate quantum transport in micrometer-sized single crystals of BiBr, a material predicted to be a second-order topological insulator. 1D topological states with long phase coherence times are revealed via the modulation of quantum interferences with magnetic field and gate voltage. In particular, we demonstrate the existence of Aharanov-Bohm interference between 1D ballistic states several micrometers long, that we identify as phase-coherent hinge modes on neighbouring step edges at the crystal surface. These Aharanov-Bohm interferences are made possible by a disordered phase-coherent contact region, the existence of which is confirmed by STEM/EDX imaging of FIB lamellae. Their coherent nature modulates the transmission of the 1D edge states, leading to weak antilocalization and universal conductance fluctuations with surprisingly large characteristic fields and a strongly anisotropic behavior. These complementary experimental results provide a comprehensive, coherent description of quantum transport in Bi4Br4 and establishes the material as belonging to the class of second-order topological insulators with topologically protected 1D ballistic states