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Targeted isolation and identification of isoquinoline alkaloids from Xylopia ferruginea bark with anti Aβ-induced paralysis activity
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On the problem of minimizing the epidemic final size for SIR model by social distancing
No full textInternational audienceWe revisit the problem of minimizing the epidemic final size in the SIR model through social distancing of bounded intensity. In the existing literature, this problem has been considered imposing a priori interval structure on the time period when interventions are enforced. We show that when considering the more general class of controls with an L1 constraint on the confinement effort that reduces the infection rate, the support of the optimal control is still a single time interval. This shows that, for this problem, there is no benefit in splitting interventions on several disjoint time periods. However, if the infection rate is known beforehand to change with time once from one value to another one, then we show that the optimal solution could consist in splitting the interventions in at most two disjoint time periods
First Study of the Nuclear Response to Fast Hadrons via Angular Correlations between Pions and Slow Protons in Electron-Nucleus Scattering
No full textInternational audienceWe report on the first measurement of angular correlations between high-energy pions and slow protons in electron-nucleus () scattering, providing a new probe of how a nucleus responds to a fast-moving quark. The experiment employed the CLAS detector with a 5-GeV electron beam incident on deuterium, carbon, iron, and lead targets. For heavier nuclei, the pion-proton correlation function is more spread-out in azimuth than for lighter ones, and this effect is more pronounced in the channel than in earlier studies. The proton-to-pion yield ratio likewise rises with nuclear mass, although the increase appears to saturate for the heaviest targets. These trends are qualitatively reproduced by state-of-the-art event generators, including BeAGLE, eHIJING, and GiBUU, indicating that current descriptions of target fragmentation rest on sound theoretical footing. At the same time, the precision of our data exposes model-dependent discrepancies, delineating a clear path for future improvements in the treatment of cold-nuclear matter effects in scattering
Convergent information flows explain recurring firing patterns in cerebral cortex
No full textInternational audienceCortical population events, short-lived patterns of neuronal activity that recur with consistency, are central to sensorimotor coordination. These reproducible firing patterns are often attributed to attractor dynamics, supported by strong mutual connectivity. However, by using multimodal datasets-including two-photon imaging, electrophysiology and electron microscopy-we show that these reproducible patterns do not involve strongly interconnected neurons. Instead, we show that cortical networks exhibit hierarchical modularity, with core neurons serving as high-information-flow nodes at module interfaces. These cores funnel activity but lack the structural signatures of pattern-completion units that are typically found in attractor networks. Using computational models, we find that distance-dependent connectivity is necessary and sufficient to produce the modularity and transient reproducible events observed in cortex. Our findings suggest that cortical networks are preconfigured to support sensorimotor coordination. This work redefines the structural and dynamical basis of cortical activity, with a focus on the relationship between modular structure and function
Social and occupational factors are associated with musculoskeletal pain prevalence in the general population: a population-based cohort study
No full textInternational audienceObjective: Musculoskeletal pain (MP) is a leading cause of disability worldwide, affecting individual well-being and public health. However, in the literature, the prevalence of MP varies considerably because of methodological inconsistencies, selection biases, and differences in case definitions. This study aimed to estimate the population-based prevalence of MP in France and identify key demographic, socioeconomic, and occupational factors associated with MP.Methods: This cross-sectional study used baseline data for the CONSTANCES cohort study, a large, population-based epidemiological study with participants representative of the French adult population (18-69 years old). Inverse probability weighting was used to correct for selection bias and to improve the generalizability of prevalence estimates. MP was were assessed with the Nordic Musculoskeletal Questionnaire, with significant pain defined as lasting >30 days in the past 12 months. Multivariate logistic regression models were used to identify factors associated with low back pain, estimating odds ratios (ORs) and 95% confidence intervals (CIs).Results: Among 193,436 participants, 46.2% reported pain in at least one anatomical site. The most affected areas were the low back (26.6% adjusted prevalence), shoulder (21.4%), neck (19.0%), and knee (19.1%). Odds of low back pain was associated with female sex (OR 1.39 [95% CI 1.32-1.47]), older age, obesity, depression (1.71 [1.62-1.80]), and comorbidity burden (1.20 [1.15-1.25]). Odds of low back pain was associated with moderate or high occupational physical activity (OR 1.33 [1.20-1.50] and 1.69 [1.48-1.93]) but was inversely associated with very active leisure-time physical activity (0.82 [0.70-0.96]). Education level but not household income was a significant socioeconomic factor associated with MP.Conclusion: MP impose a substantial burden on the French population, particularly among individuals with physically demanding jobs and low education levels. These findings highlight the paradox of physical activity associated with MP
Beyond Paired Data: Self-Supervised UAV Geo-Localization from Reference Imagery Alone
No full textInternational audienceImage-based localization in GNSS-denied environments is critical for UAV autonomy. Existing state-of-the-art approaches rely on matching UAV images to geo-referenced satellite images; however, they typically require large-scale, paired UAV-satellite datasets for training. Such data are costly to acquire and often unavailable, limiting their applicability. To address this challenge, we adopt a training paradigm that removes the need for UAV imagery during training by learning directly from satellite-view reference images. This is achieved through a dedicated augmentation strategy that simulates the visual domain shift between satellite and real-world UAV views. We introduce CAEVL, an efficient model designed to exploit this paradigm, and validate it on ViLD, a new and challenging dataset of realworld UAV images that we release to the community. Our method achieves competitive performance compared to approaches trained with paired data, demonstrating its effectiveness and strong generalization capabilities.</div
Assessing the integrity of SARS-CoV-2 and F-specific RNA bacteriophage RNA in raw wastewater (ANRS0160)
No full textInternational audienceRNA integrity is an essential parameter for analyzing the nature of viral particles, especially in environmental samples where assessing virus infectivity is often difficult or impossible. It is also an important factor in the effectiveness of virus sequencing in environmental matrices containing mixed viral populations composed of variants that differ from one another by only a limited number of mutations, such as in the case of SARS-CoV-2. This study introduces a multiplex Reverse Transcription Digital PCR (RT-dPCR) method for evaluating the RNA integrity of SARS-CoV-2 and F-specific RNA phages belonging to subgroup I (FRNAPH-I) using synthetic RNA, viral stocks, and then raw wastewater (WW) in which SARS-CoV-2 and FRNAPH-I were naturally present. An initial approach using one-step multiplex digital Reverse Transcription PCR (dRT-PCR) demonstrated unequal detection across the genomic regions of both FRNAPH and SARS-CoV-2. To overcome this methodological bias, a two-step method called Long-Range Reverse Transcription digital PCR (LR-RT-dPCR) was developed. This approach involves performing long-range reverse transcription at the 3′ end using a single specific reverse primer to generate contiguous cDNA that spans multiple targets of interest. Following cDNA synthesis, the sample is partitioned, and a multiplex amplification is carried out on targets located at the 3′ end, middle, and 5′ end of the sequence. The LR-RT-dPCR method enabled uniform detection with enhanced sensitivity and was validated using capillary electrophoresis on synthetic RNA of MS2, a phage which belongs to the FRNAPH-I subgroup. LR-RT-dPCR was employed in both triplex and quintuplex formats to analyze the MS2 phage genome (3,569 nucleotides (nt)) and SARS-CoV-2 genome (∼30,000 nt), respectively. Using this approach, viral RNA integrity was evaluated through the detection frequencies of genome fragments of the whole genome. The viral stocks of MS2 phages replicated in a laboratory and stored in phosphate-buffered saline (PBS) exhibited high RNA detection frequencies (> 50 %). In WW, RNA detection frequency was significantly lower, not exceeding 2 % even for the shortest fragment of the FRNAPH-I genome. On the other hand, SARS-CoV-2 RNA showed greater detection frequency than FRNAPH-I RNA in WW, with values exceeding 30 % for short fragments (<1,500 nt) and ranging from 0 % to 44 % for longer fragments (1,500 to 3,500 nt). The relationship between the detection frequency of a fragment and its length does not appear to be strictly linear, as factors other than length can influence genome integrity. These factors include the intrinsic properties of specific genomic regions. For example, the S3-ORF3a region of the SARS-CoV-2 genome appears particularly stable
Uncertainty in projected changes of Indian Summer Monsoon Rainfall by CMIP6 models
No full textInternational audienceA robust and trustworthy rainfall projection over the Indian landmass is vital for devising climate adaptation strategies. However, past studies show large inter-model spread in Indian Summer monsoon (ISM) rainfall projections thus calling for more detailed investigations on the underlying process. In the present study, we investigate this aspect using Coupled Model Intercomparison Project Phase 6 (CMIP6) model projections (Shared Socioeconomic Pathways, SSP5–8.5) and historical simulations. The Multi-Model Ensemble mean (MME) results show intensification of ISM rainfall at the end of the 21st century with ISM rainfall increasing by 1.6 ± 0.8 mm/day under SSP5–8.5 scenario. A moisture budget analysis for the MME further infers that the thermodynamic effect (TH) due to global warming plays a dominant role in enhancing ISM rainfall in the projections, with its dynamic counterpart (DY) assuming an additional contribution. It is also revealed that both DY and TH terms contribute to the inter-model uncertainty in ISM rainfall, but with DY dominating over the other this time. The inter-model uncertainty in DY and ISM rainfall changes is linked to inter-model spread in interhemispheric thermal contrast which in-turn depends on the diversity in Equilibrium Climate Sensitivity (ECS) and Global Mean Temperature (GMT) among the models. Intriguingly, when we remove the inter-model diversity in ECS through a GMT scaling, an Atlantic meridional surface temperature gradient, involving both land and ocean, emerges as a crucial driver in controlling the uncertainty in both DY and ISM rainfall changes, and drives large-scale monsoon circulation changes over African and the Indian subcontinents
Bright Circularly Polarized Electrochemiluminescence from Heterobinuclear Ir III –Au I Enantiomers
No full textInternational audienceThe development of efficient circularly polarized electrochemiluminescence (CP‐ECL) probes is still at its infancy and examples are still very limited. Yet, their achievement would enable gathering a readout that carries privileged information on the probe's chiral environment by monitoring luminescence polarization bias with high signal‐to‐noise ratio. Notwithstanding, this is a highly challenging task and requires judicious chemical engineering of chiral ECL‐active emitters. Herein, we aim at expanding the palette of CP‐ECL luminophores by presenting a novel class of enantiopure heterobinuclear Ir(III)–Au(I) complexes, which are investigated thoroughly by means of chemical, structural, and (chiro‐)optical techniques. The ground and excited state properties are also elucidated by using density functional theory (DFT) approaches including spin‐orbital coupling (SOC) perturbation. The chiral‐at‐metal complexes display luminescence with a polarization bias of the emitted light that is function of the helical arrangement of the coordination sphere around the Ir(III) center. Overall, the photo‐ and electro‐active complexes unraveled in this work combine unparallelly high photoluminescence quantum yield in the orange region, excellent circularly polarized luminescence (CPL) brightness up to 4.5 M −1 cm −1 with a notable ECL activity. Finally, these features provide emitters with CP‐ECL efficiency that encompass remarkably by a factor 3.5 that of the well‐known benchmark tris ‐(2,2′‐bipyridyl)ruthenium(II)