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Sulfate adjustment and early reactivity in cements containing kaolinitic calcined clays: investigation and assessment via a sulfate-limited model system
No full textInternational audienceUnderstanding the early reaction kinetics of calcined clays (CCs) in calcined clay-limestone cements (CCLC) is required to optimize the formulations for optimal early performance. In this study, a clinker-free sulfate-limited model system (SLiM) is utilized to compare the early reactivity of 9 diverse natural CCs. The SLiM consists of an excess of CC and portlandite, and limited gypsum It is demonstrated that the sulfate-carrier depletion time provides a rate of reaction for each clay which is characteristic of its reactivity in a blended cement. As such, it is shown that the SLiM test can be used to probe physico-chemical properties, including the standard enthalpy of formation of metakaolinite, and to understand the mechanical performance and hydration of blended cement with these clays up to 3 days. In conclusion, a foundation for a standard test allowing to adjust gypsum content in CCLC from a single calorimetry measurement is developed
Persistence of vegetative and sporulated forms of Clostridium perfringens exposed to air at different relative humidities
No full textInternational audienceC. perfringens, an anaerobic bacterium, is a common cause of food poisoning that can persist on surfaces in slaughterhouses. However, the mechanisms governing its survival in such environments – characterised by variations in relative air humidity (RAH) – remain poorly understood. This study aimed to evaluate the effect of air exposure on C. perfringens survival and to identify the mechanisms responsible for its inactivation. Vegetative cells and spores of C. perfringens were deposited on inert surfaces and exposed to different RAH (11 %, 43 %, 75 %, 100 %) under both aerobic and anaerobic conditions, to assess the contributions of osmotic and oxidative effects induced by dehydration to cell death. At low RAH, more than 99 % of vegetative cells were inactivated within one day, regardless of oxygen presence. Epifluorescence microscopy and flow cytometry analyses revealed that dehydration and rehydration disrupted membrane integrity, contributing to inactivation through lethal mechanical damage. At 100 % RAH, vegetative cells survived over 3 days under aerobic conditions (>1 %) and over 30 days under anaerobic conditions (>0.003 %). The composition of the dehydration medium had little effect on cell survival. In contrast, spores were much more resistant, with around 10 % survival after two months of stress in presence of oxygen, without any significant effect of dehydration. These results highlight the potential of exploiting RAH fluctuations to develop control strategies targeting C. perfringens vegetative cells. However, the extreme resilience of spores confirms the need for specific and targeted decontamination methods to eliminate them effectively
Introduction
No full textInternational audienceIl est peu habituel d’étudier le religieux, qu’il s’agisse du sentiment ou du clergé, sous l’angle d’un protecteur des droits et institutions. Parfois vu comme une menace ou comme un obstacle vers un régime libéral construit sur une base laïque comme en Occident, les clercs, toutes religions confondues, ont néanmoins développé un discours en ce sens. Sans toujours être conciliant avec les libertés individuelles, son étude s’impose néanmoins pour saisir ce qu’il veut proposer au monde moderne
On the space of subgroups of Baumslag-Solitar groups II : High transitivity
No full textA continuation of "On the space of subgroups of Baumslag-Solitar groups I: perfect kernel and phenotype", by Alessandro Carderi, Damien Gaboriau, François Le Maîitre, Yves Stalder (hal-03829832). 44 pages, 1 figureInternational audienceWe continue our study of the perfect kernel of the space of transitive actions of Baumslag-Solitar groups by investigating high transitivity. We show that actions of finite phenotype are never highly transitive, except when the phenotype is 1, in which case high transitivity is actually generic. In infinite phenotype, high transitivity is generic, except when |m|=|n| where it is empty. We also reinforce the dynamical properties of the action by conjugation on the perfect kernel that we had established in our first paper, replacing topological transitivity by high topological transitivity
Modeling and correction of sensitivity thresholds determined by best EstimateThreshold (BET)
No full textInternational audienceThe r-Alternative Forced Choice (r-AFC) test is a test of discrimination in which the subject is presented with three samples, one of which is a test sample containing a nominated stimulus (test sample), the other being references. The subject is instructed to indicate the test sample. Taste and odor sensitivity thresholds are frequently determined using successive r-AFC tests with stimuli in increasing concentrations. The Best Estimate Threshold (BET) method consists in using successive 3-AFC with increasing concentrations to estimate sensitivity threshold. Then, the threshold is estimated using the geometrical mean of the highest concentration that caused an error and the concentration directly below it. However, a subject who feels no difference between the samples may give a correct answer by chance. It leads to consequent potential bias in the determination of the sensitivity thresholds. This paper aims to formalize and model the thresholds obtained in successive r-AFC in order to quantify the errors inherent in such protocols. It establishes that, when you assumed that the distribution of the true sensitivity threshold is known in the population, the threshold obtained by r-AFC can be modelled with a variable following a specific probability law. This paper presents the theory of this model, then illustrate it with simulations and application on a real dataset. An R package dedicated to these analyses, AFCR, was also created and is available on github (https://github.com/ChemoSens/AFCR). Therefore, sensory scientists could use the package as a help to set up their sensory protocol or-to analyze their own data
Herbicide-induced metabolic changes in a plant-aphid system: how soil bacteria drive the fate and impact of a residual dose of Isoproturon?
No full textInternational audienceAgriculture intensification, massively relying on pesticides, led to the widespread contamination of noncrop terrestrial ecosystems. Soil contamination with pesticide residues widely occurs but its cryptic effects on terrestrial biotic interactions remain unclear, especially at the metabolic scale. We studied the effects of an environmental dose of the herbicide isoproturon on an isoproturon-degrading Sphingomonas soil bacteria - Lolium perenne (Poaceae) and Rhopalosiphum padi (Hemiptera: aphididae) system - in the laboratory. This system is typical of contaminated peri-agricultural ecosystems, such as vegetated buffer strips. We found that isoproturon and its main degradation product transferred from the substrate to aphids, accumulating in plant shoots. No macroscopic effects of the herbicide were observed, but primary metabolites varied in both plants and herbivores. Inoculation of isoproturon-degrading bacteria reduced isoproturon levels in the substrate and suppressed most metabolic variations. Moreover, inoculation of the non-degrading bacterial strain impacted plant metabolism, potentially through mutualistic interaction, underlining the close link between soil microbiota and aboveground organisms. This study shows that isoproturon residues can transfer in a typical grassland trophic system, altering the metabolism of each biological level. It emphasizes the need to consider above- and belowground interactions when assessing seminatural ecosystems' responses to chronic contamination
Tissue from gender-affirming genital surgery as a model for human penile physiology research: promise, ethics, and scientific duty. A gift from transgender women to the science of male sexuality
No full textInternational audienc
Semantic Equirectangular Visual Tracking in Lightweight 3D Building Reconstructions
No full textInternational audienceAccurate visual localization often relies on dense, high-fidelity 3D models, which provide rich geometric and photometric detail but are expensive to acquire, heavy to store, and limited in scalability. As an alternative, lightweight city models represent only coarse building volumes, offering compactness, accessibility, and privacy but posing challenges for reliable alignment due to the lack of textures and fine structure. This work addresses these challenges by introducing a semantic equirectangular Gaussian Mixture–based virtual visual servoing approach that aligns real panoramic images with synthetic views rendered from lightweight building models. The method combines semantic building masks with Gaussian Mixtures, a seamless formulation, and frequency-domain computation to overcome the poor gradients of direct photometric binary-mask alignment while maintaining computational efficiency. Experiments on outdoor trajectories demonstrate accurate and stable tracking, robustness under frame skipping, and resilience to dynamic occlusions through semantic masking. These results indicate that reliable localization is feasible with coarse city models, providing a scalable alternative to high-fidelity reconstructions and opening perspectives for deeper integration of semantic rules into the localization process
Epigenetic regulation of mycorrhizal symbioses: from plastic responses to transgenerational legacies
No full textInternational audienceMycorrhizal symbioses represent one of the most widespread and ecologically significant plant–microbe interactions, shaping plant nutrition, stress resilience, and ecosystem functioning. Beyond their role in nutrient exchange and systemic defense, growing evidence suggests that these symbioses also influence plant plasticity within and across generations through epigenetic regulation. These mechanisms operate throughout the mutualistic interaction, from fungal recognition and root colonization to symbiosis functioning, by regulating gene networks that control signaling, defense suppression, and nutrient exchange. By integrating environmental cues into potentially heritable gene regulatory states, epigenetic regulation fine‐tunes within‐generation responses and may also contribute to effects across generations, thereby influencing adaptation and resilience. The extent of mycorrhiza‐induced epigenetic inheritance likely depends on the host's reproductive strategy and lifespan. Clonal propagation and shorter‐lived hosts tend to preserve epigenetic marks, whereas sexual reproduction and longer‐lived species show partial resetting. This contrast shapes offspring performance, ecological interactions, and evolutionary trajectories. Here, we synthesize current knowledge on the epigenetic regulation of mycorrhizal symbioses, draw parallels with other plant–microorganism interactions (including plant–pathogens and plant–endophytes), highlight its role in within‐generation plasticity and propose a potential role across generations. We outline future research directions to disentangle the stability, ecological relevance, and evolutionary significance of mycorrhiza‐mediated epigenetic inheritance
Non-farm entrepreneurship and children's schooling: Panel data evidence from rural Côte d'Ivoire
No full textInternational audienceThis paper investigates the impact of household participation in non-farm enterprises on children’s school enrolment in Côte d’Ivoire, focusing on children aged 3 to 12—the formative years for early learning and cognitive development. Using household-level panel data and two rigorous empirical strategies, we examine whether engaging in non-agricultural income-generating activities improves educational outcomes. Our findings indicate that participation in rural non-farm enterprises significantly reduces the number of out-of-school children, suggesting a positive link between income diversification and educational investment. Disaggregating results by location and gender reveals important differences. Non-farm entrepreneurship is positively associated with boys’ school enrolment in both rural and urban areas, whereas the positive effect for girls is observed only in urban settings. This highlights a persistent gender gap in rural education access that non-farm income alone may not fully address. These results have clear policy implications. Promoting non-farm enterprise development—particularly in rural areas—can improve school participation rates, especially for boys. However, complementary interventions may be needed to ensure girls benefit equally. Overall, the study underscores the role of rural non-farm entrepreneurship in advancing human capital through enhanced educational outcomes