Propagation and scattering of ultrasonic waves in macroscopically anisotropic polycrystalline materials with fiber texture

International audienceThis work investigates the scattering of ultrasonic elastic waves in polycrystalline materials with macroscopic transverse isotropy (TI). Using the Dyson equation with the First-order smoothing approximation (FOSA) for the mass operator, we obtain the complex wavenumber of the qL, T 1 , and qT 2 waves in 3D and qL and qT 2 in 2D. The equations are properly modified by including the Green solution for the reference TI homogeneous medium. Additionally, 2D numerical finite element (FE) models are developed, allowing for a direct comparison with the 2D theoretical amplitude attenuation and phase velocities estimations. The numerical simulations are carried out with a set of periodic boundary conditions (PBC), leading to a proper plane wave propagation even in the case of macroscopic anisotropy. The influence of the orientation of the axis of symmetry on the attenuation and phase velocities is discussed. The role of the symmetry-axis orientation is analyzed, and scattering mechanisms are contrasted between 2D and 3D. Numerical and theoretical results show excellent agreement, confirming the increased wave dispersion when propagation occurs along the cross-fiber (or cross-symmetry-axis) direction

Sex specific correction of maternal inflammation-induced behavioral abnormalities by the inhibition of colony-stimulating factor 1 receptor

International audienceWe have previously reported the therapeutic effect of depletion and renewal of endogenous microglia on autism spectrum disorder-like behaviors in offspring from the dams under maternal immune activation (MIA) by dampening their neuritogenic activation. Here we show a long-lasting pathological effect by MIA, leading to abnormal behaviors in offspring mice in a sex-specific manner at 3 months of age. MIA are induced by injecting Polyinosinic:polycytidylic acid [Poly(I:C)] at 10 mg/kg at E9.5 with preselected dams based on the immunoreactivity to low-dose Poly(I:C) injection. MIA offspring show impairments in sociability and associative memories in both sexes, whereas spatial working memory deficit was observed only in females. MIA does not affect social novelty, novel object recognition, anxiety-like behavior nor sensori-motor or locomotor activity. Administering colony-stimulating factor receptor (CSF1R) inhibitor in young adult MIA offspring renews microglia and ameliorates sociability deficits only in males, and spatial working memory only in females while associative memory impairments are reversed in males and partially restored in females. Transcriptomic analysis of prefrontal cortex and hippocampal tissues reveals synaptogenesis and cholesterol biosynthesis as male and female specific MIA pathways respectively, underpinning sex-dependent response to CSF1R inhibitor treatment. Our results reveal the sex specific therapeutic applications of CSF1R inhibitor for MIA-related social and cognitive disorders

Connecting the Atlantic Meridional Overturning Circulation to the Southern Ocean Following the Closure of Equatorial Seaways During the Cenozoic

International audienceAbstract Global ocean circulation regulates climate and has undergone significant changes over the Cenozoic. Today, the Atlantic Meridional Overturning Circulation (AMOC) is driven by North Atlantic Deep Water (NADW) formation and Southern Ocean upwelling. By contrast, during the middle Eocene to early Oligocene (48–28 Ma), a restricted Drake Passage was limiting the northern Ekman transport, while a circum‐equatorial current sustained by trade winds promoted low‐latitude upwelling. Our set of simulations with the IPSL‐CM5A2 model reveals that this paleogeographic setting favored proto‐NADW upwelling at low latitudes, confining the AMOC to the Northern Hemisphere. Consequently, the role of southern westerly winds was limited, and the northward heat transport was weaker than in the modern ocean

Antibiotic Use and the Persistence of Biologic Therapies in Patients With Psoriasis

International audienceImportance The long-term effectiveness of biologic therapies in psoriasis may decline over time. Gut microbiota alterations induced by antibiotics have been proposed as a potential mechanism impairing biologic persistence. Objective To evaluate the association between antibiotic exposure and the persistence of biologic therapies in patients with psoriasis. Design, Setting, and Participants This retrospective cohort study used data from the French National Health Insurance database between June 2011 and December 2022. Adults initiating a biologic therapy for psoriasis were included, excluding those with preexisting inflammatory bowel disease at baseline. Data were analyzed from January to September 2024. Exposures At baseline, antibiotics exposure was classified as none, 1, or 2 or more dispensations in the 6 months preceding the index date. During follow-up, time-dependent antibiotics exposure was defined as none, 1, or 2 or more antibiotics dispensations in the 6 months prior to each time of follow-up. Main Outcomes and Measures The primary outcome was discontinuation or switch of the initial biologic therapy. Exposure to antibiotics was assessed within 6 months prior to biologic initiation and during follow-up. A weighted Cox marginal structural model was used to estimate adjusted hazard ratios. Results Of 36 129 included patients, 11 228 (42.0%) were female, 20 192 (55.9%) were male, and the mean (SD) age was 48.4 (15.1) years. A total of 9366 (25.9%) were exposed to antibiotics at baseline and 21 900 (60.6%) during follow-up. The most commonly prescribed antibiotic classes were β-lactams, macrolides, and fluoroquinolones. Antibiotic exposure was associated with a higher risk of biologic discontinuation (weighted hazard ratio, 1.12; 95% CI, 1.08-1.16), with a stronger effect observed for multiple dispensations (weighted hazard ratio, 1.29; 95% CI, 1.24-1.35), suggesting a dose-response relationship. Conclusions and Relevance In this cohort study, antibiotic exposure was significantly associated with an increased risk of discontinuation of biologic therapies in psoriasis. These findings support the hypothesis that antibiotics, potentially through gut dysbiosis, may reduce biologic persistence. However, unmeasured confounders limit causal interpretation. Further studies are necessary to validate these findings

Euclid: An automated system to match Rubin transient alerts to Euclid observations

International audienceThe Vera C. Rubin observatory is expected to produce 10 million transient alerts per night in ugrizy filters, whilst Euclid is a visible to near-infrared space telescope engaged in a wide field survey. We present a prototype system to automatically match the transient alerts from Rubin to Euclid observations. The system produces joint light-curves containing both visible and near-infrared photometry, and joint image cutouts. Using Zwicky Transient Facility alerts as a proxy for Rubin, we demonstrate the system in use in cases where Euclid did and did not detect the transient and highlight the value that can be added in each case. For transients detected by Euclid these benefits include identifying the supernovae (SNe) in observations taken prior to ground-based detection, thereby better constraining the explosion time, such as SN 2024pvw detected ~3 d prior to ground based detections. In cases where Euclid did not detect the transient, we demonstrate the benefit of adding Euclid observations to improve host morphology measurements and associations

Autoencoders reveal polyunsaturated fatty acids (PUFA)-Related metabolic signature linked to cancer risk

International audienceBackground: Metabolomics is a valuable tool for characterising biological mechanisms involved in cancer development, but produces complex datasets with intricate interdependencies. While linear dimension reduction techniques such as principal component analysis (PCA), have proven useful to summarise informative hidden patterns, biological evidence suggests metabolic relationships extend beyond linearity. Non-linear dimension reduction techniques, such as autoencoders (AEs), may identify more meaningful components.Methods: We applied AEs and PCA to metabolomic data available for 5828 matched case-control pairs from 8 cancer-specific case-control studies nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, and compared their performance. We evaluated the association between components identified by AEs and PCA with cancer risk, and explored the biological interpretation of components through their association with genetic factors and selected biomarkers.Findings: PCA and AEs showed similar reconstruction performance. PCA's first component (PCA.1) captured phosphatidylcholines (PCs) as the primary source of variability and was associated with cancer risk. Conversely, AEs decomposed PC metabolism into two components, one of which exhibited a stronger association with cancer risk than PCA.1. Unlike PCA.1, this component was strongly associated with genetic variants mapping to the TMEM258 and FADS genes, key in polyunsaturated fatty acids (PUFA) biosynthesis and regulation. Consistently, the AE component demonstrated stronger associations with circulating omega-3 and omega-6 PUFA levels than PCA.1.Interpretation: Linear methods remain adequate for general dimension reduction. However, AEs better captured specific pathways, identifying a component reflecting perturbations in PUFA metabolism associated with cancer risk

Effective Field Theory in Long-Baseline Neutrino Oscillation Experiments

International audienceWe study the phenomenology of physics beyond the Standard Model in long-baseline neutrino oscillation experiments using the most general parametrisation of heavy new physics in the framework of Standard Model Effective Theory (SMEFT), as well as its counterpart below the electroweak scale, Weak Effective Field Theory (WEFT). We compute neutrino production, oscillation, and detection rates in these frameworks, consistently accounting for renormalisation group running as well as SMEFT/WEFT matching. We moreover use appropriately modified neutrino--nucleus cross sections, focusing specifically on the regime of quasi-elastic scattering. Compared to the traditional formalism of non-standard neutrino interactions (NSI), our approach is theoretically more consistent, and it allows for straightforward joint analyses of data taken at different energy scales and by different experiments including not only neutrino oscillation experiments, but also searches for charged lepton flavour violation, low-energy precision measurements, and the LHC. As a specific example, we carry out a sensitivity study for the DUNE experiment and compute projected limits on the WEFT and SMEFT Wilson coefficients. Together with this paper, we also release a public simulation package called ``GLoBES-EFT'' for consistently simulating long-baseline neutrino oscillation experiments in the presence of new physics parameterized either in WEFT or in SMEFT. GLoBES-EFT is available from \href{https://github.com/SalvaUrrea2/GLoBES-EFT}{GitHub}

Euclid: Constraints on f(R) cosmologies from the spectroscopic and photometric primary probes

International audience$\textit{Euclid}$ will provide a powerful compilation of data including spectroscopic redshifts, the angular clustering of galaxies, weak lensing cosmic shear, and the cross-correlation of these last two photometric observables. In this study we extend recently presented $\textit{Euclid}$ forecasts into the Hu-Sawicki $f(R)$ cosmological model, a popular extension of the Hilbert-Einstein action that introduces an universal modified gravity force in a scale-dependent way. Our aim is to estimate how well future $\textit{Euclid}$ data will be able to constrain the extra parameter of the theory, $f_{R0}$, for the range in which this parameter is still allowed by current observations. For the spectroscopic probe, we use a phenomenological approach for the scale dependence of the growth of perturbations in the terms related to baryon acoustic oscillations and redshift-space distortions. For the photometric observables, we use a fitting formula that captures the modifications in the non-linear matter power spectrum caused by the $f(R)$ model. We show that, in an optimistic setting, and for a fiducial value of $f_{R0} = 5 \times 10^{-6}$, $\textit{Euclid}$ alone will be able to constrain the additional parameter $\log f_{R0}$ at the $3\%$ level, using spectroscopic galaxy clustering alone; at the $1.4\%$ level, using the combination of photometric probes on their own; and at the $1\%$ level, using the combination of spectroscopic and photometric observations. This last constraint corresponds to an error of the order of $6 \times 10^{-7}$ at the $1\sigma$ level on the model parameter $f_{R0} = 5 \times 10^{-6}$. We report also forecasted constraints for $f_{R0} = 5 \times 10^{-5}$ and $f_{R0} = 5 \times 10^{-7}$ and show that in the optimistic scenario, $\textit{Euclid}$ will be able to distinguish these models from $\Lambda\mathrm{CDM}$ at more than 3$\sigma$. (abridged

Convex computation of regions of attraction from data using Sums-of-Squares programming

International audienceThis paper focuses on the analysis of the \ac{RoA} for unknown autonomous dynamical systems. A data-driven approach based on the moment-\ac{SoS} hierarchy is proposed, enabling novel \ac{RoA} outer approximations despite the reduced information on the dynamics. The main contribution consists of bypassing the system model and, hence, the recurring constraint on its polynomial structure. Numerical experiments showcase the influence of data on learned approximating sets, highlighting the potential of this method

Evaluating solid-state neutron detectors for measuring 14 MeV neutrons at high temperatures

International audienceSilicon Carbide 4H Polytype (4H-SiC) and Diamond wide bandgap semiconductors are promising detector materials for fusion environments. Threshold energy nuclear reactions provide information on the energy of impinging fast neutrons and the combination of low intrinsic carrier concentration with high thermal conductivity makes these semiconductors suitable for high-temperature applications, especially for neutron monitoring in tritium production through ITER breeding blankets. While the carrier properties of SiC and Diamond offer interesting charge collection dynamics from room temperature up to 200 °C, the stability of their detection performance at high temperatures above 200 °C remains to be confirmed. To investigate this, we conducted a measurement campaign in a fast neutron field representative of fusion reactors at the GENESIS (Generator of Neutrons for Science and IrradiationS) research platform of LPSC (Laboratoire de Physique Subatomique et de Cosmologie) laboratory in Grenoble, France. Both 4H-SiC and Diamond sensors were irradiated with 14 MeV fast neutrons from a D-T neutron generator while encapsulated in a heating device, recording current signals from room temperature up to 500 °C. Using a direct measurement method of charge carrier collection dynamics as a function of applied bias voltage and temperature by pulse shape analysis provided information on velocity drift and collected charge. The results offer a first representative study of charge carrier mobility behavior with increasing temperature up to 500 °C. The stability of performance in terms of CCE (charge collection efficiency) has been demonstrated for SiC from room temperature up to 500 °C, while Diamond experiences a CCE drop of 60% between 200 °C and 300 °C