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« Le paradoxe de la concordia discors dans la description de l’expérience musicale à la Renaissance : écriture, enjeux et inflexions »
No full textInternational audienceCet article interroge simultanément les formes et les fonctions du motif de la concordia discors dans les descriptions d’œuvres d’art à la Renaissance, qu’elles s’attachent à la mu-sique, mais aussi aux arts visuels. Il s’agit en particulier d’étudier en quoi la concordia discors constitue à la fois un lieu commun de l’évocation, mais aussi un principe d’écriture et de lecture aux accents néoplatoniciens, puisqu’il invite le lecteur à rechercher dans la va-riété et l’abondance de la description un principe d’unité supérieur, de s’abstraire de la di-mension sensible pour contempler l’Idée
Conditions de mise en œuvre de la tomodensitométrie pour l’ étude d’ un couteau médiéval découvert en contexte préventif (diagnostic « Cœur de Ville » à Buzançais, Indre)
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Humans can accurately categorise negative but not positive emotional facial expressions in horses
No full textInternational audienceRecognising emotional facial expressions plays a key role in communication, both within and between species. Many non-human animals, including horses, discriminate and react to emotional human facial expressions. This raises the question of whether humans also consider some animals' facial expressions when determining their emotional states. To address this, the present study aimed to assess human ability to categorise horses' facial expressions according to their valence (positive/negative) and arousal (high/low), across eight distinct situations likely to elicit emotions (e.g., social isolation, going to a food bucket), and whether prior experience referring to the level of contact with horses improved this ability. An online task, in the form of a quiz, was conducted in which human participants were asked to categorise photographs of horses' facial expressions based on perceived emotional valence and arousal. Results showed that participants (n = 930) performed well in the valence categorisation of expressions displayed in situations likely to elicit negative emotions (e.g., social isolation: 90 % of correct categorisation, sudden stimulus: 91 %), and that experience with horses improved performance in these cases. However, participants had greater difficulty in categorising the valence of facial expressions emitted in positive contexts (e.g., grooming: 42 %, going to a food bucket: 59 %), and experience, based on their level of contact, did not consistently enhance performance. Low arousal context (resting in the sun: 93 %) was well recognised, while categorisation accuracy for high arousal contexts (e.g., going to a food bucket: 55 %, sudden stimulus: 96 %) was more variable. These findings suggest that humans have a limited ability to recognise horses' emotional states based on facial expressions, particularly for positive emotions, highlighting the need for increased awareness and caution when interpreting them. Accurate recognition of animals' emotional facial expressions is therefore crucial, as it contributes directly to the broader assessment of their welfare
Évaluer la traduction automatique à l’ère de l’IA : de la métrique à l’évaluation humaine (étude de cas français–chinois dans le domaine médical)
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Rapid cell turnover to model adipocyte size distribution
No full textInternational audienceWhite adipose tissue, composed of adipocyte cells, primarily stores energy as lipid droplets. The size of adipocytes varies significantly within the tissue according to the amount of stored lipids. A striking observation is that the adipocyte size distribution is bimodal, and thus, this tissue is lacking a characteristic size.We propose a novel dynamical model, based on a partial differential equation, to represent the adipocyte size distribution. The model assumes continuous adipocyte growth, with a velocity dependent on cell radius and extracellular lipid availability, together with constant rates of cell recruitment and death.We prove the existence and local stability of a unique stationary solution for a broad range of growth velocity functions. Choosing a parsimonious formulation, we show that only three parameters are enough to describe adipocyte size distributions measurements in rats. These parameters are robustly estimated through approximate Bayesian computation, and the model demonstrates excellent agreement with experimental data. This mechanistic, three-parameter framework offers a new and interpretable approach to characterizing adipocyte size distributions
A rapid immunochromatographic assay for the detection of BK Polyomavirus in urine samples from hematopoietic stem cell transplant recipients
No full textInternational audienceHemorrhagic cystitis (HC) following hematopoietic stem cell transplantation (HSCT) is a significant event that can lengthen hospital stays and the need for care. The causes of HC can be multiple, but BK Polyomavirus (BKPyV) is the main protagonist in frequency. Currently, the clinical tool widely used to detect the presence of the virus in urine is PCR-based viral genome testing. We have developed a new rapid test for the antigenic detection of BKPyV in urine. The aim of this diagnostic study was to retrospectively evaluate the performance of this new assay as compared to BKPyV PCR on urine from HSCT patients with suspected HC. 49 samples from 49 different patients were evaluated, 20 of whom presented with HC. Of these 20 samples, 19 (95%) were positive by the rapid antigen test. Of the 37 BKPyV PCR-positive samples, 31 were above 7log10 copies/mL, including the 20 patients with HC. Thus, the overall performance of the rapid test for HC is greatly improved compared with PCR, with specificity rising from 62.1% to 86.2% and positive predictive value from 64.5% to 82.6%. In conclusion, this new tool could be implemented as a point-of-care test to rapidly confirm or rule out a suspicion of BKPyV-HC after HSCT
Optimal Dirac controls for time-periodic bistable ODEs, application to population replacement
No full textThis work addresses an optimal control problem on a dynamics governed by a nonlinear differential equation with a bistable time-periodic nonlinearity. This problem, relevant in population dynamics, models the strategy of replacing a population of A-type individuals by a population of B-type individuals in a time-varying environment, focusing on the evolution of the proportion of B-type individuals among the whole population. The control term accounts for the instant release of B-type individuals. Our main goal, after noting some interesting properties on the differential equation, is to determine the optimal time at which this release should be operated to ensure population replacement while minimizing the release effort. The results establish that the optimal release time appears to be the minimizer of a function involving the carrying capacity of the environment and the threshold periodic solution of the dynamics; they also describe the convergence of the whole optimal release strategy. An application to the biocontrol of mosquito populations using Wolbachia-infected individuals illustrates the relevance of the theoretical results. Wolbachia is a bacterium that helps preventing the transmission of some viruses from mosquitoes to humans, making the optimization of Wolbachia propagation in a mosquito population a crucial issue
Selecting feeding behavior would enhance feed efficiency in slow-growing free-range broiler
No full textBackgroundIn the free-range poultry industry, commercial birds have access to outdoor environments where climatic conditions are variable and uncontrolled. However, breeding animals must be selected under confined and controlled conditions for sanitary reasons. These environmental differences can reduce selection efficiency due to genotype-by-environment (G×E) interactions, particularly affecting feed efficiency—a key trait for sustainability that impacts both economic performance and environmental footprint. Therefore, selection based solely on performance in confined conditions may not be optimal for free-range systems.To enhance sustainability in such systems, it is important to identify indoor traits genetically correlated with outdoor feed conversion ratios. This study investigates the potential for integrating feeding behavior traits into selection schemes for slow-growing broiler chickens raised outdoors during summer.ResultsWe analyzed various feeding behaviors expressed indoors, including the number of meals, the timing and distribution of intake, and their variability both within and across days, as well as the correlation between these feeding behaviors and temperature. Many traits exhibited moderate to high heritability and were genetically correlated with outdoor feed conversion ratios. However, the correlations between traits are not always favorable: some behavioral traits were positively correlated with feed conversion ratio but they were negatively correlated with each other.To address these interactions, we tested a G matrix approach, which quantifies the genetic variances and covariances among traits. Using the G matrix framework, we identified two main axes, gmax and g2, accounting for 74% of the genetic variance in feeding behaviors. The gmax axis included meal frequency, early-day consumption, and day-to-day variation in morning intake and meal number, while g2 axis was mainly correlated with traits related to early morning intake. Selection on the gmax axis could enhance feed efficiency and meat quality without compromising carcass yield, unlike selection on g2, which may improve feed efficiency at the expense of meat quality and carcass composition.ConclusionsThese findings suggest that incorporating feeding behavior traits, particularly those aligned with gmax, into indoor selection schemes could significantly enhance feed efficiency in outdoor environments
Decoding Cerebrospinal Fluid: Integrative Metabolomics Across Multiple Platforms
No full textInternational audienceCerebrospinal fluid (CSF) is a key biological matrix that reflects the physiological and pathological states of the central nervous system (CNS). It supports brain function by regulating ionic balance, facilitating molecular transport, and clearing metabolic waste. In this article, we present a standardized protocol for CSF collection along with an integrative multiplatform metabolomic workflow that combines proton nuclear magnetic resonance spectroscopy (1 H-NMRS) and high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Integrating these complementary analytical modalities enhances metabolite coverage and improves analytical robustness, enabling a more comprehensive and reliable characterization of the CSF metabolome. This workflow supports the discovery of potential biomarkers and advances our understanding of neurochemical alterations within the CNS