Publications scientifiques de l'Université de Reims Champagne-Ardenne
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Vers une structuration nationale de l’enseignement en médecine du sommeil : création du Collège national des enseignants en médecine du sommeil (CNESom)
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Organics in the stratosphere: new insights from weather balloon flights conducted in France
No full textInternational audienceAtmospheric aerosols significantly influence the Earth’s climate, yet they remain a major source of uncertainty in climate projections. Here, we present a set of unique offline analysis of organics collected from the ground to the stratosphere with ultimate sensitivity using a new balloon-borne sampling technique deployed on simple weather balloons. Activated and functionalized carbon fabrics were used to target chemical compounds in the gaseous and aerosol forms during three flights over France. Ultra-high-resolution mass spectrometry, enabling the detection of thousands of organic compounds, and highlighted high-carbon-number organics, indicating oligomerization in long-lived tropical stratospheric air masses. Our measurements suggest that large stratospheric sulfate aerosols from volcanic eruptions could play a role in the formation of secondary aerosols in internally mixed particles and may explain the presence of organics with higher carbon numbers. These measurements revealed a drop in the number of unsaturated carbons at higher altitudes
Adapting the City to the Specific Sensory Needs of Autistic People: A Participatory Research Approach
No full textInternational audienceContext: Cities are spaces in which our senses are particularly solicited: vehicle noise, light reflections on glass surfaces, illuminated signs, food odors and more.... For people with atypical neurological or sensory functioning, such as autistic individuals, the intense sensory stimulation present in urban environments can make cities overwhelming, limiting their autonomy and quality of life. The aim of this study is to identify the micro-designs of public space that are favorable and unfavorable to people with autism, based on their experiential knowledge.Method:During the first stage, this participatory project was designed by a consortium of researchers, autistic people, clinicians and local authority representatives, all of whom were involved in decision-making throughout the project’s stages., After receiving ethical approval, an initial phase consisted of semi-structured interviews conducted with 20 autistic adults and 20 professionals who work with them on a daily basis (e.g., specialized educators, psychologists). Participants were asked to express their experience of the city, based on photographs of the urban environment (streets, crosswalks, benches). In a second phase, five design thinking workshops were held with local authority staff (road planning, accessibility),organizations and autistic people, to present the results and foster the collaborative development of solutions, using the various expertise, to make the city more accessible.Results: Overall, urban designs of cities are often a significant source of fatigue, physical discomfort or pain, anxiety and even distress for autistic people. However, micro-designs modifications in public spaces can improve their experience autonomy. Findings showed that sidewalks should be sufficiently wide, with clear traffic- flows rules and indicators, visually-defined boundaries with the roadway, shaded, and not cluttered on the ground. Crosswalks should follow a standardized structure to facilitate identification and use. Vehicles and bicycles speeds should be reduced. Finally, incorporation of quiet areas, plants or water features (fountains, streams) can improve the urban experience for autistic people. The presence of dogs was also identified as an area of interest for some autistic people and warrants further exploration.Discussion: Reducing sensory stimuli to those useful for interaction with urban environments can help limit sensory overload. Physically structuring public spaces to take account of visual, deficit of visual function and vestibular particularities, along with the creation of recuperation areas through increased natural elements, and clearly defined public space usage rules would improve the autonomy for autistic people. Only a participatory approach involving the voices of people with autism and professionals can gather this type of information, which comes under the heading of user expertise. Future perspectives include testing the effect of these micro-adaptations on the behavior and well-being of autistic people during their regular walk but also better characterize the neurovisual and vestibular disorders that have an impact on the urban experience of autistic people.Conclusion: Cities are rich in stimuli that are often poorly adapted to the atypical functioning of autistic people. However, simple solutions can be implemented to enhance walkability, autonomy and overall well-being for neurodivergent individuals in urban environments
Controlling Lampenflora in Heritage Sites: In Situ Testing of Polyoxometalate–Ionic Liquids in the Pommery Champagne Cellar
No full textInternational audienceArtificial lighting, essential for geotouristic purposes in subterranean sites, has facilitated the growth of colored photosynthetic organisms (lampenflora) on monumental 19th century bas‐reliefs of the Pommery Champagne cellar—a UNESCO‐protected heritage site—causing significant aesthetic and physical deterioration. To sustainably preserve these stone artworks, biocidal polyoxometalate–ionic liquids (POM‐ILs) are tested alongside the commercial biocide Preventol RI80 on three trial zones: cleaned and colonized areas of a wall and clean stone samples positioned on a testing station within the cellar. After 1 year, untreated control areas exhibit growth/regrowth of biofilms, whereas surfaces treated with POM‐ILs or Preventol RI80 remain biofilm free. Measurements of colorimetry and chlorophyll fluorescence confirm the effectiveness of both biocides in controlling photosynthetic micro‐organisms. However, confocal fluorescence microscopy highlights a reduced long‐term inhibition by Preventol RI80 compared to POM‐ILs, despite the latter being applied at lower concentrations. Metagenomic analysis further validates the performance of POM‐ILs, showing a notable decrease in microbial richness and diversity in treated areas. While both products effectively inhibit phototrophs and fungi, their efficacy against Pseudomonadota is limited, likely due to microbial adaptation via antibiotic resistance genes. This study underscores the potential of POM‐ILs as a sustainable alternative for preserving cultural heritage against microbial colonization
Segmentation et modélisation du réseau vasculaire cérébral par apprentissage profond
No full textCardio-neurovascular diseases are the leading cause of death worldwide and represent a major public health challenge. Imaging of the cerebral vascular network has significantly improved the diagnosis of these pathologies, and automated image processing algorithms now play a key role in assisting physicians. These algorithms generally rely on the segmentation of the cerebral vascular network. For this reason, automating this task has garnered significant interest.Despite advances, current automatic segmentation methods still suffer from major limitations. They struggle to preserve the topology and connectivity of vascular networks, and traditional segmentation metrics are not well-suited to the geometric complexity of the cerebrovascular network. Additionally, manual annotation, necessary for training these models, remains a time-consuming and tedious task, hindering the creation of annotated datasets.In this thesis, we focus on cerebrovascular segmentation from TOF MRA images. First, we propose a multitask model based on a topological cost function to improve the connectivity of segmentations. Additionally, we introduce a new metric, called ccDice, to quantify topological errors. Finally, we study the impact of annotation scarcity and noise, and we formulate recommendations for clinicians to improve annotation quality, thereby fostering the development of more efficient learning models in the future.Les maladies cardio-neurovasculaires sont la première cause de mortalité dans le monde et représentent un enjeu majeur de santé publique. L'imagerie du réseau vasculaire cérébral a considérablement amélioré le diagnostic de ces pathologies, et les algorithmes de traitement d'images automatiques jouent désormais un rôle clé en assistant les médecins. Ces algorithmes reposent généralement sur la segmentation du réseau vasculaire cérébral. Pour cette raison, l'automatisation de cette tâche suscite aujourd'hui un intérêt majeur.Malgré des avancées, les méthodes actuelles de segmentation automatique présentent encore des limitations majeures. Elles peinent à préserver la topologie et notamment la connectivité des réseaux vasculaires, et les métriques de segmentation traditionnelles ne sont pas adaptées à la complexité géométrique du réseau cérébrovasculaire. De plus, l'annotation manuelle nécessaire pour entraîner ces modèles demeure une tâche chronophage et fastidieuse, freinant la création de jeux de données annotés.Dans cette thèse, nous nous intéressons à la segmentation cérébrovasculaire à partir d'images ARM TOF. Nous proposons en premier lieu un modèle multitâche basé sur une fonction de coût topologique permettant d'améliorer la connectivité des segmentations. Puis, nous proposons une nouvelle métrique, appelée ccDice, permettant de quantifier les erreurs topologiques. Enfin, nous étudions l'impact du manque et du bruit des annotations, et formulons des recommandations à destination des cliniciens pour améliorer la qualité des annotations, favorisant ainsi le développement de modèles d'apprentissage plus performants à l'avenir
Mast Cells Promote Inflammatory Th17 Cells and Impair Treg Cells Through an IL-1β and PGE2 Axis
No full textInternational audiencePurpose: CD4+ effector T cells (Teffs) play a key role in immune responses by infiltrating the sites of inflammation and modulating local leukocyte activity. In turn resident immune cells shape their response. This study aimed to investigate the influence of mast cells (MCs) on Teff biological responses. Methods: This study examined human MC-Teff interactions, focusing on how MCs shape Teff responses. Flow cytometry, qRT-PCR, and cytokine assays were used to analyze the impact of primary human MCs on the Teff phenotype and function. MC-Teff crosstalk within Crohn’s disease patient tissues was assessed using confocal microscopy and advanced image analysis. Results: MCs promoted the differentiation of Th17 cells, particularly the inflammatory Th17.1 subset, that secretes IFN-γ and GMCSF. This differentiation was driven by the PGE2 and IL-1β axis. Additionally, MCs disrupted the phenotype and impaired the suppressive function of regulatory T cells (Tregs) through PGE2, skewing the Th17/Treg balance. The analysis of biopsies from patients with Crohn’s disease indicated that this MC/Teff crosstalk may play a role in the pathogenesis of auto-inflammatory processes. Conclusion: MCs influence CD4+ T cell responses by fostering pro-inflammatory Th17 differentiation while impairing Treg function. This interaction underpins a Th17/Treg imbalance, which is significant in auto-inflammatory diseases such as Crohn’s disease, positioning MCs as critical drivers of disease pathogenesis. Plain language summary: The immune system functions through complex interactions between different types of cells to protect the body from harm. CD4+ T cells are crucial in managing inflammation by directing other immune cells. Mast cells, found in tissues such as the skin and gut, are among the first to respond to potential threats and can influence T cell behavior. This study examined how mast cells and T cells interact in vitro, particularly in Crohn’s disease, a condition in which the immune system causes gut inflammation. We used laboratory techniques to study how mast cells affect T cells, examining their behavior and communication. We also studied tissue samples from individuals with Crohn’s to determine how these interactions occur in real life. We found that mast cells encourage the development of inflammatory T cells called Th17, particularly a type known as Th17.1, which produce strong inflammatory signals. This process relies on specific molecules such as PGE2 and IL-1β. Simultaneously, mast cells weaken the function of regulatory T cells (Tregs), which normally help control inflammation. This leads to an imbalance between Th17 cells and Tregs, tipping the immune system toward excessive inflammation. In tissue samples from Crohn’s disease patients, we found evidence of this imbalance, suggesting that mast cells play a major role in driving harmful inflammation. These findings help us understand why inflammation becomes uncontrollable in diseases such as Crohn’s disease. They also suggest that targeting mast cells could be a promising strategy for new treatments
Contextualisation du FL2i : norme, pratiques d'enseignement et intégration professionnelle en contexte plurilingue
No full textInternational audienceCette communication propose d'examiner la contextualisation des pratiques d'enseignement du Français Langue d'Intégration et d'Insertion (FL2i) au sein des dispositifs de formation destinés aux métiers en tension, notamment dans les secteurs du bâtiment, des services à la personne et de l’hôtellerie-restauration. La problématique centrale de cette étude concerne l’impact de la contextualisation sur les normes linguistiques, la sélection des contenus à enseigner et les pratiques pédagogiques en lien avec les exigences des environnements professionnels. Ainsi, il s’agit de comprendre comment l’adaptation de l’enseignement aux spécificités des secteurs en tension peut améliorer l’insertion socioprofessionnelle des apprenants. L'analyse met en lumière les enjeux liés à l’ajustement de la norme linguistique et des pratiques pédagogiques face aux exigences professionnelles. L'objectif est de répondre aux besoins de travailleurs plurilingues confrontés à des situations de travail spécifiques et complexes, nécessitant une maîtrise des compétences linguistiques adaptées à des contextes variés. Nous postulons que la contextualisation de l'enseignement en FL2i contribue à l'insertion efficace des apprenants dans leurs secteurs d'activité, en favorisant leur participation active aux interactions professionnelles. Nous nous concentrerons sur une analyse des expériences pratiques acquises au sein du Dispositif d’Apprentissage du Français Langue Étrangère au service de l’Insertion Professionnelle (DAFIP), ainsi que sur le dispositif d’« apprentissage de la langue française à visée professionnelle multisectoriel », récemment lancé en 2024. Les données exploitées incluent des observations de terrain, des retours d'expérience d'apprenants, ainsi que desévaluations des résultats d’insertion professionnelle. Mon expérience en tant que praticienne dans ces dispositifs viendra enrichir cette réflexion, illustrant comment la contextualisation vise à répondre aux impératifs d’insertion sociolinguistique et professionnelle des apprenants. En prenant en compte les normes sociolinguistiques correspondant à la réalité du terrain, ces dispositifs rendent les codes linguistiques professionnels plus accessibles. Cela facilite non seulement l'insertion des apprenants dans leur secteur d'activité, mais également leur participation active aux interactions professionnelles et à la dynamique de travail, comme le soulignent Boutet (2001), ainsi que Coste, Moore et Zarate (1997). De plus, en s’éloignant des normes monovariétales rigides, comme discuté par Guerin (2010), ces dispositifs valorisent la diversité langagière, considérée comme une ressource pédagogique et culturelle essentielle en contexte plurilingue. Cette approche plurielle se révèle propice pour permettre aux apprenants d’enrichir les interactions et de naviguer avec aisance dans des environnements professionnels variés. La méthodologie d'analyse se concentrera sur l'ajustement des pratiques didactiques en contexte professionnel, notamment par le biais de méthodes pédagogiques actives et de mises en situation authentiques. Cela permettra d'observer comment le FL2i répond aux besoins spécifiques des apprenants en insertion, ainsi que la manière dont les dispositifs sont conçus pour leur permettre d'acquérir des compétences linguistiques directement mobilisables dans des contextes professionnels concrets, renforçant ainsi leur employabilité : une démarche qui transcende l'enseignement traditionnel de la langue et s'inscrit dans une perspective d'inclusion professionnelle et sociale. Elle souligne aussi l'importance d'une norme linguistique contextualisée, adaptée aux exigences du milieu de travail, dans l'enseignement du français pour adultes, comme l’affirment Cuq et Gruca (2003), ainsi que Mangiante et Parpette (2004). En conclusion, cette communication vise à apporter des éléments de réponse aux questions soulevées lors du colloque, concernant l'impact de la contextualisation sur les normes du français, sur la sélection des contenus à enseigner et sur les pratiques d'enseignement. Cette réflexion s'ancre dans une volonté d'identifier des pratiques pédagogiques adaptées aux enjeux contemporains d'insertion sociolinguistique et professionnelle. Enfin, l'approche préconisée met en avant la nécessité d'une flexibilité et d'une adaptation face à la diversité des réalités rencontrées par les apprenants, afin de permettre une meilleure intégration dans le monde dutravail et une participation active à la société
