HAL-Université de Bretagne Occidentale
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Evidence of long-lasting associations between related and unrelated individuals in a subantarctic killer whale population
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L'Espagne et les fonds structurels européens : captation maîtrisée, gestion fragmentée et défis de gouvernance
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Communauté de pratique en santé : engagement des membres et posture de praticienne-chercheure
No full textLa communication se propose d'explorer les grandes lignes d'une recherche menée pour la réalisation d'un mémoire de master 2 en sciences de l'éducation et de la formation. En alternance dans un organisme de formation dédié aux métiers de la rééducation-réadaptation, nous avons œuvré à la mise en place d'une communauté de pratique intentionnelle, dispositif répondant à quatre grands enjeux du secteur : l’interdisciplinarité, le travail ensemble, l'amélioration des pratiques et la formation continue des professionnel·les. Pour mettre en place cette communauté de pratique, les conditions ont dû être pensées pour favoriser l’engagement des membres présent·es aux rencontres. En mobilisant le cadre théorique de l'environnement capacitant, nous interrogeons les facteurs à l’œuvre dans le processus d’engagement des membres de cette communauté de pratique. Grâce à une méthodologie qualitative avec des entretiens individuels et collectifs auprès de certains membres, nous mettrons en lumière les différents facteurs individuels, sociaux et environnementaux et leur articulation individuelle et collective. L’ancrage dans le terrain de cette recherche sera l'occasion de revenir : d'une part, sur la posture de praticien·ne-chercheur·e éprouvée, et d'autre part, sur des préconisations à quatre niveaux : le secteur de la santé, l'organisme de formation, la communauté et ses membres et enfin, la recherche.[Cette recherche a été menée dans le cadre du Master Stratégie et Ingénierie en Formation d’Adultes (SIFA) proposé à l’Université Rennes 2,adossé au Centre de Recherche sur l'Éducation, les Apprentissages et la Didactique (CREAD) et réalisé en alternance au sein de l’Institut deFormation en Pédicurie-Podologie, Ergothérapie et Masso-Kinésithérapire (IFPEK) de Rennes.]</i
Ethnicity affects relapse-free survival in immune-mediated thrombotic thrombocytopenic purpura
No full textInternational audienceImmune-mediated thrombotic thrombocytopenic purpura (iTTP) is caused by a severe, antibody-mediated deficiency of ADAMTS13 (A Disintegrin And Metalloproteinase with ThromboSpondin-1 motifs, 13th member) activity. The B-cell depleting agent rituximab is effective in restoring ADAMTS13 activity and therefore preventing relapses. However, the risk of relapse appears heterogeneous among patients, although the underlying causes are elusive. Preliminary reports suggested that African ancestry could be associated with decreased relapse-free survival (RFS). Data from the registry of the French National Thrombotic Microangiopathy Reference Center were used to further address the role of ethnicity on response and RFS after rituximab administration in the acute as well as in the preemptive setting. A total of 790 patients (134 patients of African ancestry and 656 patients of European ancestry) were included in the study. Time from rituximab administration to ADAMTS13 recovery was comparable between the two cohorts. Patients of African ancestry had inferior 3-year combined RFS after the first rituximab-treated episode compared to patients of European ancestry (
Assessing the effects of three harmful microalgal species on spermatozoa and embryos of the king scallop Pecten maximus
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Static bending of micromorphic Timoshenko beams
No full textInternational audienceAbstract This paper investigates statics and natural vibration of linear elastic cubic lattices, together with their continuum approximations. The lattice endowed with central and angular interactions, referred to as Gazis et al . ’s, is considered first: since the stiffness of each lattice phase must be positive, the equivalent macroscopic Poisson’s ratio must be lower than its central limit 1/4. A volumetric interaction based on a volume-dependent internal pressure is introduced as an additional non-central interaction for a complete calibration of the equivalent Poisson’s ratio up to its incompressibility limit 1/2. This volumetric interaction can also be classified as Fuchs-type, providing a potential energy that depends on the volume variation of each cell. The mixed differential-difference equations of the associated lattice derive from Hamilton’s principle applied to the discrete energies. The algebraic properties of the stiffness matrix of the discrete cell provide information on the positive definiteness of the potential energy, for each lattice with central and non-central interactions. The convergence of this finite lattice towards a linear elastic continuous right parallelepiped is shown in several static loading schemes. The discrete Lamé problem for the free vibration of this parallelepiped is solved for all the considered lattices. It is concluded that discrete and continuum elasticity can be connected by this cubic lattice within a complete range of elasticity parameters
Culturable macroplastic-associated potential human pathogens in coral reef lagoons, Madagascar
No full textInternational audiencePotentially human pathogenic bacteria (PHPBs) have been detected in plastic-associated marine microbiomes, primarily through DNA-based methods. However, data on their culturability and concentrations on plastics remain limited, yet are essential to assess actual health risks. To address this gap, 70 floating macroplastic and 20 seawater samples were collected from two human-impacted reef lagoons in southwestern Madagascar (Atsimo-Andrefana region). PHPBs were cultured from their microbiomes using selective media and quantified. Macroplastics were predominantly polypropylene (34 %) and polyamide (31 %). In increasing order of concentration, four culturable PHPBs, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Vibrio Harveyi clade species, were identified on both macroplastics and in seawater, across all sites and polymer types. Notably, 52 % of macroplastic samples harbored two PHPB species simultaneously, while only 7 % were PHPB-free. Concentrations of all PHPBs were consistently and significantly higher on macroplastics than in seawater, regardless of the measurement unit or polymer type, with the Vibrio Harveyi clade being the most abundant. No significant correlations were observed among PHPB species concentrations, suggesting limited interaction and independent colonization. These findings indicate that floating macroplastics may serve as reservoirs and fomites for viable PHPBs. However, their potential impacts on ecosystems and human health should be interpreted cautiously. We emphasize the need to contextualize PHPB concentration data by considering factors such as exposure pathways, environmental persistence, and bacterial virulence, rather than relying solely on concentration-based comparisons, which may lead to misinterpretation
B cell-intrinsic IL-2 signaling regulates inflammation by promoting IL-10 expression in CD25(+) age-associated B cells
No full textInternational audienceInterleukin (IL)-2 can impact both plasma cell (PC) differentiation and the generation of IL-10(pos) B cells. We generated mice bearing a B cell-specific deletion of Il2rb (Il2rb(ΔB)) to define the B cell-intrinsic role of IL-2. Il2rb(ΔB) mice displayed normal B cell development and homeostasis but increased extrafollicular PC responses upon immunization. In vitro, IL-2 sustained both PC differentiation and expression of a regulatory program. In vivo, IL-2 signaling defined a PDCA-1(pos) splenic B cell subset exhibiting age-associated B cell (ABC) features. Mechanistically, synergistic IL-2 and IFN-γ signaling induced expression of the transcription factor Maf in these ABC progenitors. MAF promoted IL-10 expression and repression of pro-inflammatory programs. In a preclinical multiple sclerosis model, CD25(pos) ABCs contributed to the pool of protective regulatory B cells, and loss of IL-2 signaling reduced IL-10(pos) B cells in the central nervous system and exacerbated neuroinflammation. Thus, IL-2 signaling promotes the generation of IL-10(pos) ABCs, with implications for autoimmunity and inflammation
A code distribution-based trajectory representation and its application to similarity, clustering and classification of AIS big data
No full textInternational audienceAutomatic Identification System (AIS) data received from vessels in a maritime area of interest is a valuable resource for understanding vessel behavior and gaining insights into maritime activities. This paper presents a novel approach for representing vessel trajectories using code distribution and analyzing AIS trajectory big data through machine learning techniques. By introducing PQk-means vector quantization algorithms, AIS trajectory data records are transformed into a series of code documents. Applying the TF-IDF (Term Frequency-Inverse Document Frequency) technique from text mining to these code documents produces a code distribution-based representation of vessel trajectories. This preliminary process enables the application of machine learning algorithms to AIS trajectory big data. Using this representation, three types of applications have been developed: detecting similar trajectories and vessels using vector space models and cosine similarity, clustering voyages and vessels with the K-means algorithm, and recognizing vessels with support vector machine algorithms. The potential of the proposed approach is demonstrated through a series of experiments using practical AIS datasets from a region in northwest France. Overall, the experimental results show that the proposed approach is highly effective for mining AIS big data, outperforms other methods, and confirms its ability to handle high-dimensional trajectories and massive amounts of AIS data within a reasonable computational cost. Moreover, this work provides an opportunity to develop an AIS-oriented version of a large language model based on our code distribution representation of trajectories, and to extend trajectory representation to any type of moving object or numerical vector from diverse sensors
Fault Injection Attacks in On-Chip Interconnects: A Comparative Study of Wishbone, AXI-Lite, and AXI
No full textInternational audienceFault injection attacks exploit physical disturbances to compromise the functionality and security of integrated circuits. As Systemon-Chip (SoC) architectures grow in complexity, the vulnerability of onchip communication buses has become increasingly prominent. Buses, serving as interconnects among various IP cores, represent potential attack vectors for fault-based exploitation. In this study, we perform simulation-driven fault attack injection across three mainstream bus protocols-Wishbone, AXI-Lite, and AXI. We systematically examine fault attack success rates, spatial vulnerability distributions, and timing dependencies to characterize how faults interact with bus-level transactions. The results uncover consistent behavioral patterns across protocols, offering practical insights for both attack modeling and the development of resilient SoC designs.</div