From settling to rheology and hydration: How fine fractions govern the behavior of cement-based suspensions

International audienceThis study investigates the role of fine particles in governing macroscopic behaviors of suspensions, in particular, cement-based pastes. Granulometric analyses were performed on both raw and binary systems of Portland cement with limestone filler re-grinded or not (LF2, LF1), and fly ash (FA) at various substitution rates (0–100 % vol) to modify fine particle content and identify a particle size threshold. Based on granulometric analyses, a threshold of 5 μm was justified and chosen for subsequent investigation. Suspension stability was assessed using Turbiscan Lab, measuring both settling velocity and supernatant clarity. The results indicate that systems with a higher fine fraction, such as those with LF2 (97.6 %), exhibit enhanced stability, as evidenced by significantly reduced settling velocity compared to LF1 (54.4 %) that demonstrates moderate stability, and FA (34.4 %) that displays pronounced instability. Rheological measurements were performed on raw and 50 % binary systems, and the results revealed that systems with a higher fine fraction exhibit a higher storage modulus G', notably LF2 compared to LF1 and FA, and OPC-50LF2 compared to OPC-50LF1 and OPC-50FA, indicating a denser structural network. Additionally, systems with a high fine fraction displayed a lower percolation threshold confirming the enhanced ability of fine particles to form interconnected networks. Isothermal calorimetry further showed that replacing 50 % of OPC with LF2 and LF1 leads to an increase in the intensity of the main hydration peak by 58 % and 47 %, respectively, compared to pure OPC, indicating that the nucleation-precipitation effect is more pronounced when more fine particles in the system

“Rap as Gaeilge and Kneecap : Turning US Hip Hop Into a Tool For Irish Identity, Resistance, And Community Bridging in Post-Conflict Northern Ireland”

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Strongly interacting matter in extreme magnetic fields

International audienceMagnetic fields are ubiquitous across different physical systems of current interest; from the early Universe, compact astrophysical objects and heavy-ion collisions to condensed matter systems. A proper treatment of the effects produced by magnetic fields during the dynamical evolution of these systems, can help to understand observables that otherwise show a puzzling behavior. Furthermore, when these fields are comparable to or stronger than Λ_QCD, they serve as excellent probes to help elucidate the physics of strongly interacting matter under extreme conditions of temperature and density. In this work we provide a comprehensive review of recent developments on the description of QED and QCD systems where magnetic field driven effects are important. These include the modification of meson static properties such as masses and form factors, the chiral magnetic effect, the description of anomalous transport coefficients, superconductivity in extreme magnetic fields, the properties of neutron stars, the evolution of heavy-ion collisions, as well as effects on the QCD phase diagram. We describe recent theory and phenomenological developments using effective models as well as LQCD methods. The work represents a state-of-the-art review of the field, motivated by presentations and discussions during the "Workshop on Strongly Interacting Matter in Strong Electromagnetic Fields" that took place in the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*) in the city of Trento, Italy, September 25-29, 2023

Territoria Naturalia. Aménager sans altérer, entre partage et réserve

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La place de l’Histoire du droit et des institutions dans les pensées libertaires

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Comparative study of three cellular materials under blast and sustained shock wave

International audienceThis study investigates the mechanical response of three cellular materials—polyisocyanurate (PIR), autoclaved aerated concrete (AAC), and Aluminum Lightweight Foam (ALF, Nufoam® 140)—under blast and shock loading conditions. The research aims to provide experimental data for optimizing building protection against explosion hazards. Laboratory-scale tests were conducted using a shock tube to generate blast and sustained shock waves. The materials’ responses were analyzed using high-speed imaging and digital image correlation. Results indicate that PIR exhibits significant deformation under sustained shocks but shows recovery under blast loading. AAC demonstrates erosion-based energy dissipation, with material loss concentrated at the extremities. ALF, serving as a reference, shows excellent mechanical energy dissipation. The study highlights the potential of these materials for applications requiring both thermal insulation and blast resistance, contributing to the development of predictive tools and larger-scale experiment designs

The transcriptome of the ovine choroid plexus is regulated by thyroid hormone but not by photoperiod

International audienceThe photoperiodic control of seasonal functions requires the action of melatonin at the pars tuberalis of the pituitary and subsequent control of local thyroid hormone (TH) signaling by tanycytes lining the basolateral part of the third ventricle. Therefore, TH supply of tanycytes through the cerebrospinal fluid (CSF) produced by the choroid plexuses (CP) is central to photoperiodism. Here, the transcriptome of the CP of the lateral ventricles was established by RNAseq in ewes maintained under three experimental conditions: ewes exposed to a short photoperiod (SP; 8.5 h of light), intact ewes submitted to an acute 3-week exposure to a long photoperiod (LP-Sham; 15.5 h of light) and ewes thyroidectomized prior to the LP exposure (LP-THX). Photoperiod impacted the expression of 1169 genes (SP vs LP-Sham) while 575 genes were sensitive to TH (LP vs LP-THX). Compared to TH-responsive genes, photoperiod-responsive genes displayed rather weak transcriptional changes. In line with this, RT-qPCR for select candidate genes validated the impact of TH, but not that of photoperiod. We demonstrate weak expression of the melatonin MT1 receptor in the CP, which provides a functional rationale for this. In conclusion, the CP appears as a permissive tissue to the expression of TH-dependent seasonality governed by tanycytes rather than being an integral component of the melatonin-dependent photoperiodic response

Le Miroir des sots de Nigel de Longchamps

International audienceFirst French translation, with commentary, of Nigel de Longchamps' (Wireker) work, Speculum Stultorum. A poem of 4000 elegiac lines, composed in Latin by this Anglo-Norman monk of the late 12th century, in which he makes, through the tribulations and encounters of the donkey Burnellus, a fierce satire of the papacy and the various religious orders of his time,Cet ouvrage propose la première traduction française, avec commentaires, de l'ouvrage de Nigel de Longchamps (Wireker), Speculum Stultorum. Il s'agit du poème de 4000 vers élégiaques, composé en latin par ce moine anglo-normand de la fin du XIIe siècle, dans lequel il fait, à travers les tribulations et les rencontres de l'âne Burnellus, une satire féroce de la papauté et es différents ordres religieux de son temps

Un dialogue qui ne dit pas son nom ? Formes, usages et limites du dialogue professionnel en PME

de La Rochefoucauld, M., Chader, A. (2025). La Régulation Interne de L'usage de L'intelligence Artificielle Générative En Entreprise : Cas D'orange. Innovations, Pub. anticipées(0), I190-XXXII.International audienceÀ l’heure où les organisations sont invitées à « ouvrir des espaces de discussion sur le travail », le dialogue professionnel suscite un intérêt croissant en tant que levier de régulation, de reconnaissance et d’adaptation. Pourtant, ce concept demeure peu stabilisé scientifiquement, notamment dans les PME où les pratiques sont largement informelles. Cet article s’appuie sur une étude qualitative menée auprès de 11 PME françaises, au travers de 44 entretiens semi-directifs croisant les regards de quatre profils d’acteurs (salariés, managers, représentants du personnel, direction). L’objectif est de mieux comprendre comment le dialogue professionnel est défini, mis en œuvre et perçu dans les pratiques organisationnelles, et comment il s’articule – ou entre en tension – avec le dialogue social. Les résultats mettent en évidence une pluralité de représentations, une prédominance des formes informelles, et un besoin de structuration lisible. Le dialogue professionnel apparaît à la fois comme ressource de management, espace d’expression ou tentative d’innovation sociale, mais aussi comme un objet ambivalent dont la légitimité dépend de sa reconnaissance et de son articulation avec les formes de représentation collective

Mind wandering and its relationship with sustained attention and executive functions in preschoolers

International audienceMind wandering (MW) is a phenomenon that has been largely described in adults, during which thoughts do not stay on the current tasks or goals. Considering its negative impact on educational outcomes, measuring and understanding MW in children is essential. MW has been associated with attentional and executive performance in children above 8 years old. Given the huge changes in attention and executive functions organization before 6 years old, our study aimed at exploring how mind wandering interacts with these processes in preschoolers.Sixty children aged 4 to 6 years old were asked to evaluate their mind wandering propensity in the classroom using an adapted daydreaming questionnaire. They were also administered neuropsychological tests and questionnaires evaluating sustained attention, processing speed, cognitive flexibility, inhibition and a selection of individual traits.Preschoolers’ self-evaluation strongly correlated with their teacher’s evaluation, showing the feasibility of assessing MW in young children. The MW scores also correlated with the children’s performance in several tests assessing sustained attention, processing speed, cognitive flexibility and inhibition, as well as some individual traits. A latent variable modeling revealed that MW is best modeled by a latent factor independent from attention, speed and inhibition, but highly correlated with attention.Our results thus reveal the central role of attention in child development, suggesting that mind wandering in preschoolers could be linked to attention immaturity