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Exploring processability limitations of commercial hard carbon for negative electrodes of Na-ion batteries
No full textInternational audienceOptimizing electrode manufacturing processes for sodium-ion batteries (SIBs) is crucial for enhancing their performance and commercial viability. This study systematically investigates the influence of critical electrode fabrication parameters, including solid content, mass loading, and calendering, on commercial hard carbon (HC) electrode properties. Slurries prepared with 35 % and 40 % solid content (SC) demonstrated distinct rheological behaviours, directly affecting electrode mechanical stability and processability. The slurry with SC-35 % provided a better balance between manageable viscosity and robust mechanical stability upon drying, whereas SC40 % slurry exhibited higher viscosity, particle agglomeration, and poorer electrode mechanical integrity. Calendering was studied at compression degrees of 10 %, 20 %, and 30 %, revealing limited effectiveness in reducing porosity due to the intrinsic mechanical properties of HC, whereas, higher compression degrees led to structural damage. Electrochemical studies conducted in half-cells (HC vs. Na) and full-cells (HC vs. Na3V2(PO4)3) clearly indicated better electrochemical performance at moderate calendering degrees (10-20 %), effectively balancing mechanical integrity and electrical conductivity. This comprehensive study results in a useful experimental database in academic literature, underscoring the importance of precise control over slurry formulation and calendering parameters to achieve structurally robust electrodes, thus significantly enhancing the practical performance of SIBs
The LISA Astrophysics "Disc-IMRI" Code Comparison Project: Intermediate-Mass-Ratio Binaries in AGN-Like Discs
No full textInternational audienceUpcoming space-based gravitational wave detectors such as LISA, the Laser Interferometer Space Antenna, will be sensitive to extreme- and intermediate-mass-ratio inspirals (EMRIs and IMRIs). These binaries are comprised of a supermassive black hole and a stellar-mass object or intermediate-mass black hole. Their detection will probe the structure of galactic nuclei and enable tests of general relativity. As these events will be observed over thousands of orbital cycles, they will be extremely sensitive to both the underlying spacetime and astrophysical environment, demanding exquisite theoretical models on both fronts to avoid biased or even erroneous results. In particular, many (E/)IMRIs are expected to occur within accretion discs around supermassive black holes, and the nonlinearities present when modeling these systems require numerical simulations. In preparation for future modeling of LISA sources, we have conducted a comparison between eight different hydrodynamical codes and applied them to the problem of a q = 10^{-4} mass ratio binary interacting with an accretion disc. Thicker discs appear more lenient, and all codes at sufficiently high resolutions are in good agreement with each other and analytical predictions. For thinner discs, beyond the reach of analytical models, we find substantial disagreement between 2D and 3D simulations and between different codes, including both the magnitude and sign of the torque. With time and energy efficiency in mind, codes that leverage moving meshes or grid-based Lagrangian remapping seem preferable, as do codes that can leverage graphical processing units and other energy-efficient hardware
A Functional Intronic Variant of LILRB1 Associated with Clinical Malaria in the Senegalese Population
No full textInternational audienceBackgroundMalaria remains a major health challenge in sub-Saharan Africa despite extensive control measures. Host genetic variation influences susceptibility, but the role of inhibitory receptors such as LILRB1—targeted by Plasmodium falciparum RIFINs—remains unclear. We investigated whether regulatory variants in LILRB1 modulate malaria risk.MethodsRegulatory variants were prioritized from African expression quantitative trait locus (eQTL) datasets by integrating linkage disequilibrium, chromatin accessibility, transcription factor binding, and immune cell–specific expression. Three non-coding variants (rs10416697, rs10423364, rs7246537) and one coding variant (rs1061680) were selected. Genotyping was performed in 267 Senegalese individuals (116 severe malaria, 74 mild malaria, 77 healthy controls). Logistic regression adjusted for age assessed genetic associations. The effect of rs7246537 on promoter activity was tested using luciferase assays.ResultsAmong 10,110 candidate eQTLs, 49 were associated with LILRB1 expression in African populations; three overlapped open chromatin near the distal promoter. Only rs7246537 showed significant association with malaria: allele A carriers had lower risk of clinical malaria (OR = 0.50, 95% CI: 0.28-0.88, p = 0.0165) and cerebral malaria (OR = 0.44, 95% CI: 0.22-0.86, p = 0.0176). rs7246537 colocalized with a YY1-binding site, and luciferase assays confirmed allele-specific effects, with the A allele driving twofold lower promoter activity compared with the G allele.Conclusionsrs7246537 is a functional regulatory variant that reduces malaria susceptibility in Senegalese populations by modulating LILRB1 expression. These findings underscore the importance of non-coding variants and inhibitory immune pathways in malaria pathogenesis
Foveated Retinotopy Improves Classification and Localization in Convolutional Neural Networks
No full textFrom falcons spotting preys to humans recognizing faces, rapid visual abilities depend on a foveated retinal organization which delivers high-acuity central vision while preserving low-resolution periphery. This organization is conserved along early visual pathways but remains underexplored in machine learning. Here we examine how embedding a foveated retinotopic transformation as a preprocessing layer impacts convolutional neural networks (CNNs) for image classification. By applying a log-polar mapping to off-the-shelf models and retraining them, we retain comparable accuracy while improving robustness to scale and rotation. We show that this architecture becomes highly sensitive to fixation-point shifts, and that this sensitivity yields a proxy for defining saliency maps that effectively facilitates object localization. Our results show that foveated retinotopy encodes prior geometric knowledge, offering a solution to visual-search and enhancing both classification and localization. These findings connect biological vision principles with artificial networks, pointing to new, robust and efficient directions for computer-vision systems
Atypical thioredoxin Patrx2 enhances alginate production in mucoid Pseudomonas aeruginosa
No full textInternational audiencePseudomonas aeruginosa, an opportunistic human pathogen, is known for its ability to respond and adapt to its environment, employing intricate adaptation mechanisms that can lead to the formation of complex biofilms. Redox processes play a pivotal role in bacterial adaptation mechanisms. The cytoplasm of most organisms is recognized for maintaining a reducing environment through thiol-disulfide oxidoreductases. In Pseudomonas aeruginosa, we have identified an unusual cytoplasmic thioredoxin named Patrx2. What sets Patrx2 apart is its active site, which contains a consensus sequence, CGHC, identical to the characteristic motif of protein disulfide isomerases (PDIs) found in eukaryotic cells. Our investigations have unveiled that Patrx2, unlike canonical thioredoxins, exhibits disulfide isomerase activity in vitro and displays physicochemical properties, as well as a structural conformation of its catalytic site, reminiscent of PDIs. Using a mutant transposon library, we found that the expression of patrx2 is regulated by the alternative sigma factor AlgU, which is implicated in the formation of alginate biofilms in P. aeruginosa. We further demonstrated strong patrx2 expression in a mucoid strain we constructed, carrying the clinically relevant mucA22 mutation frequently found in cystic fibrosis patients. Furthermore, our results showed a significant decrease in alginate synthesis in a patrx2 mutant in this mucoid strain, this effect was also observed in the C34S catalytic variant, suggesting a role for Patrx2's catalytic site in this phenotype. The study of Patrx2, an atypical thioredoxin expressed within an alginate biofilm, underscores the importance of redox regulation in adaptation mechanisms. The induction of Patrx2's expression in alginateproducing biofilms highlights its potential relevance in redox-regulated adaptation mechanisms.</div
A New Experimental Protocol for Assessing Hominoid Assisted Arboreal Bipedalism
No full textInternational audienceArboreal bipedalism is suggested as a precursor and adaptive locomotor mode for the immediate ancestor of hominin terrestrial bipedalism, yet detailed investigation of its locomotor biomechanics is hindered by its low frequency and observation difficulties in free-ranging hominoids. Further difficulties are faced in the creation and installation of a suitable experimental setup in natural settings. Captive studies may potentially reduce logistical issues, but data on arboreal bipedalism are scarce. We present an experimental design and protocol for collecting video data on arboreal bipedalism in captive primates, from which qualitative and quantitative gait data can be extracted. Our protocol increases the frequency of this rare behavior. Data were collected on six adult chimpanzees (three males, three females) at La Vallée des Singes, Romagne, France. The chimpanzees voluntarily engaged with a simulated arboreal foraging scenario consisting of two parallel PVC tubes and a high-value food reward. Five GoPro cameras recorded interactions with the experimental equipment. For validation of the effectiveness of our experimental design, protocol interactions were identified as successful (activity completed) or unsuccessful. All age and sex classes had successful interactions. Full strides were observed alongside the identification of two forms of arboreal bipedalism, forward-facing and sideways. This highlights the variation within the arboreal bipedalism locomotor category and the capacity for our experimental design to provide suitable data for gait parameter analysis and interspecies comparisons. Our protocol thus permits detailed investigation of arboreal bipedalism's role in the evolution of hominin bipedalism
EHPAD : Comment concilier rentabilité, qualité des soins et humanité ?
No full textCas CCMP G2169, 36 pages (+78 pages de note pédagogiques
Parietal alpha frequency shapes own-body perception by modulating the temporal integration of bodily signals
No full textInternational audienceAn influential proposal in the field of cognitive neuroscience suggests that alpha-frequency brain oscillations constrain the temporal sampling of external sensory signals, shaping the temporal binding window (TBW)-the interval during which sensory signals are integrated. However, whether alpha frequency modulates the integration of self-related sensory signals and the perception of the body as one's own (body ownership) remains unknown. Here, we demonstrate that individual alpha frequency (IAF) from the parietal cortex predicted TBWs and perceptual sensitivities in body ownership and visuotactile simultaneity judgment tasks, with faster frequencies narrowing TBWs and increasing sensitivities, and vice versa. Modulating IAF through brain stimulation altered TBWs and sensitivities, establishing a causal relationship. Computational modeling linked IAF to uncertainty in asynchrony information within the causal inference process. These findings demonstrate that parietal alpha frequency shapes the sense of body ownership by modulating the temporal integration of bodily sensory signals.Multisensory integration refers to the brain's ability to combine sensory information from different modalities into coherent perceptions 1 . This integration process optimizes perception by increasing precision and reducing uncertainty through the utilization of all available sensory information. However, a fundamental challenge for the brain, discussed in the 19th century by the pioneering physiologist and physicist Hermann von Helmholtz, is determining which sensory signals should be integrated and which should be segregated. Sensory signals originating from the same external object or event should be integrated, whereas those from different sources should not. Information from the spatiotemporal correlations among sensory signals helps solve this 'multisensory integration problem', with temporal discrepancies playing a critical role 2 . When there is no, or only a very small, temporal discrepancy between two different signals, they are more likely to be caused by the same event or object and should therefore be integrated. Conversely, larger temporal discrepancies suggest that the signals relate to different events or objects and thus that multisensory integration should not occur, leaving the signals segregated. Therefore, the 'temporal binding window' (TBW) is a crucial notion in multisensory integration. The TBW refers to the temporal interval within which sensory stimuli are more likely to be integrated into a unified percept 3-7 . The TBW also relates to the ability to discriminate different events in time, which depends on signals being separated outside the binding window. The TBW varies across individuals and contributes to individual differences in the temporal resolution of multisensory information processing 3-7 .An influential theory in psychology and neuroscience research proposes that alpha oscillations play a role in sampling sensory signals into discrete perceptual frames, thereby determining the width of the TBW 8-13 . According to this theory, visual perception and multisensory perception occur within a discrete temporal window governed by the frequency of alpha oscillations, which segment perceptual information into perceptual units. Consequently, variations in the frequency of alpha oscillations predict variations in the TBW and the temporal</div
Change in standing acetabular orientation 2 years postoperatively after surgical correction of adult spinal deformity
No full textInternational audienceIntroductionAlthough sagittal alignment is known to influence pelvic position, few studies accurately identify the relationship between sagittal alignment and acetabular orientation. We hypothesized that postoperative PT should be correlated with acetabular change in native hips after surgical correction of adult spinal deformity.The objective of this study was therefore to describe the correlation between the change in pelvic tilt and the change in acetabular orientation two years after surgical correction of adult spinal deformity.Material and methodBased on a retrospective study of a prospective mono center database, 127 acetabuli out of sixty-nine patients were analyzed preoperatively and at two years postoperatively of surgical management of sagittal imbalance by posterior arthrodesis extended to the pelvis. The analysis was based on bi-planar EOS radiographs with 3D reconstructions of the pelvis and spine using SterEOS 3D software.The following specific parameters were analyzed: sacral slope, pelvic tilt, lumbar lordosis, SVA, acetabulum tilt (AT), anteversion (AA) (orientation of the acetabulum in the axial plane), abduction (AAbd) (orientation of the acetabulum in the frontal plane), inclination (AI) (orientation of the acetabulum in the sagittal plane), and anterior acetabulum coverage (ACA).A Pearson correlation was performed between the pre-and postoperative change in acetabular parameters (right and left) and pelvic parameters. Linear regressions were performed to identify the most relevant pelvic and spinal parameters. A subgroup analysis was performed to identify a difference between distal sacral and distal ilium fixations.ResultsAll measured acetabular parameters were significantly different two years after surgery. Changes in AT (p = 0.03), AI (p = 0.03) and ACA (p = 0.05) were significantly greater in the ilium fixation group. Postoperative PT reduction was strongly correlated with the decrease of AT and AA ( = 0.61 and = 0.57, p < 0.001), it was also correlated with the increase of AI and ACA and the decrease of AAbd. The entire cohort linear regression analysis revealed that a 1 ° decrease in PT resulted in a 0.4 ° decrease in AA and a 0.6 ° decrease in AT (R2 = 0.45 and = 0.38).ConclusionOur study highlights the significant influence of the change in sagittal alignment on acetabular orientation in standing position. This correlation explains the increased risk of anterior hip impingement, the change in acetabular load distribution that might lead to early hip osteoarthritis, and the overall change in the subjects' gait pattern
Distinct contributions of suspended and sinking prokaryotes to mesopelagic carbon budget
No full textInternational audienceThe mesopelagic zone, between 100 and 1000 meters depth, is a crucial layer, in which carbon preliminary coming down from the surface is transformed before a portion makes it into the deep ocean. While eddies and their fronts influence surface productivity and carbon export, their effects deeper in the water column remain poorly understood. Here we show the importance and contribution of dark carbon fixation—the conversion of inorganic into organic carbon by prokaryotes—across five contrasting hydrological features in the North Atlantic, using isotopic tracers and quantification of chemoautotrophy genes. The approach allows simultaneous assessment of dark carbon fixation and heterotrophic activity of prokaryotes living suspended in seawater and attached to gravitationally settling particles. Our results highlight that heterotrophic prokaryotes attached to sinking particles contribute up to 21% of the total organic carbon required to sustain prokaryotic metabolism under the influence of eddy fronts. In contrast, dark carbon fixation by suspended prokaryotes can contribute up to half of the total carbon input to the mesopelagic zone in the cyclonic eddy. Our findings challenge the idea that carbon cycling in the mid-depth ocean is uniform, and highlight the need to integrate microbial fractions and physical heterogeneity into ocean carbon model