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Finite Element Modeling of Compression Therapy in Lower Limb Lymphedema
No full textInternational audiencePatients with lower limb lymphedema experience lymphatic fluid accumulation and swelling, which can progress to fibrosis and fat deposition in the soft tissues, impacting patients physically, socially, and psychologically. Compression therapy is one of the main treatments for lymphedema, but its effects on lymphedematous soft tissues are not yet fully understood. In this study, we developed a finite element model of a lymphedematous leg including subcutaneous and muscle tissues, as well as skin and fascia cruris, to investigate the hydrostatic pressure distribution resulting from the interface pressure applied by a compression stocking. The results highlight the significant influence of the leg's external geometry on the interface pressure, and demonstrate the importance of modeling skin to accurately predict hydrostatic pressure distribution in the subcutaneous tissue, with a 3.5% reduction in leg volume observed after compression. The outcomes improve the understanding of the effects of compression therapy on lower limbs affected by lymphedema and support the development of adapted treatment strategies for patients.</div
Deformation-aided lung segmentation: Introducing the DALS network for efficient learning
No full textInternational audienceNon-invasive regional lung function assessment holds promise for personalized treatment planning in critical care settings. However, to assess lung parenchymal aeration from 3D computed tomography scans, the lungs must be isolated from other organs. This task is difficult in acute respiratory distress syndrome, where extensive and heterogeneous consolidations suppress contrasts within the lungs and between the lung parenchyma and surrounding tissues. Despite the promising performance of deep learning models, the high amount of annotated data required to train such models remains an issue. Here, we propose a multitasking deep neural network, in which lung segmentation in pairs of 3D scans acquired at two different volumes benefits from the estimated deformation field between the two scans. Our learning framework limits the need for annotations: deformation learning is unsupervised, while segmentation learning requires annotations -reference lung masks -only for one scan per pair. We trained our method on moderate to severe ARDS cases without specific preprocessing for noise or artifacts. Evaluated on sixteen challenging cases and compared to three state-of-the-art models, it demonstrated superior performance, while using half as many annotations for training. Although the strongest competitor achieved, on average, the same overlap with the reference lung masks (mean Dice score 0.931), our model generated significantly fewer outliers (mean Hausdorff distance from reference mask surface 26.4mm vs. 50.5 mm)
Sidelobes-Free Wavelet-Based Chirp Compression For Ultrasound Imaging
No full textInternational audienceChirp-coded excitation improves signal-to-noise ratio in ultrasound imaging, but conventional matched filtering introduces high sidelobes that degrade image quality. Alternatives such as mismatched filtering reduce resolution, while Wiener filtering depends on accurate SNR estimation and may amplify noise. In this work, we adapt the Fourier-Wavelet Regularized Deconvolution (ForWaRD) algorithm for chirp compression, exploiting shrinkage in both Fourier and wavelet domains. Simulations and experiments demonstrate that the proposed waveletbased filter outperforms conventional methods by combining high axial resolution with strong sidelobe suppression and effective noise reduction.</div
Cycling in the City: Situated Practices and Unequal Policies
No full textInternational audienceAs illustrated by the Graz Declaration, the development of new alternative and ecological modes is one of the major avenues for accounting for environmental transformations in the field of everyday mobility. Awareness of global environmental changes, health concerns, incorporation of cycling into the digital economy, as well as the electrification of some vehicles have put cycling on the agenda of public authorities and businesses. This chapter presents a synthesis of the existing literature on the return of cycling to the city and on the socio-spatial inequalities that traverse it. The actors in the production of the city who contribute to the development of cycling mobility, and therefore to its being more or less egalitarian, are varied. Comparative approaches focus mainly on public policies and their effects, generally evaluated by modal share or by statistics of use of self-service bicycle systems
[Entretien] - La planification est-elle indispensable au maintien des activités productives ?
No full textInternational audienceEntretien paru dans : Diaz, Isabelle; Guigou, Brigitte. Les sentiers de la ville productive : lectures transversales d'un défi contemporain, PUCA; Institut Paris Région, pp.94-103, 2025.https://www.urbanisme-puca.gouv.fr/les-sentiers-de-la-ville-productive-lectures-a2985.htm
L’entretien comme exercice littéraire : Sangre en el Sur de Saúl Ibargoyen
No full textInternational audienceSangre en el Sur: el fascismo es uno solo (2007), du romancier et poète uruguayen Saúl Ibargoyen entremêle témoignage biographique et fiction d’une manière qui ne peut laisser les sciences sociales indifférentes. Il se présente en effet comme un entretien qu’un narrateur (qu’on devine double de l’auteur) accorde à un enquêteur désireux de rassembler des témoignages sur la dernière dictature uruguayenne (1973-1985). Le récit restitue l’expérience singulière d’une séquence historique traumatique, comme le ferait la retranscription d’un entretien enregistré (des cassettes sont mentionnées et l’écriture reproduit le style oral, avec ses hésitations et familiarités). Il livre également les impressions de l’interviewé devant l’exercice du témoignage, avec ses silences pudiques, réticences devant une curiosité déplacée, méfiances quant à l’usage de ses paroles ou défaillances mémorielles. Que l’apparente retranscription soit en fait un exercice littéraire invite à une réflexion épistémologique sur les rapports que les données des sciences sociales, et spécialement le témoignage oral, entretiennent avec la fiction, notamment sous l’angle des tensions entre vocations documentaire et littéraire, entre fiabilité mémorielle et reconstruction ex-post, ou entre singularité d’expérience et processus historique
Two-Step Femtosecond Laser Ablative strategy for the fabrication of Au-Ni-based and Au-Co-based Nanoparticles with Tunable Plasmonic and Magnetic Behaviors
No full textMagnetic-plasmonic nanoparticles (MP-NPs), combining the localized surface plasmon resonance (LSPR) of noble metals with the magnetic response of transition-metal oxides, represent a versatile class of multifunctional nanomaterials with applications in sensing, catalysis, and biomedicine. However, their structure and properties are highly sensitive to synthesis conditions. Herein, we report a controlled, two-step strategy based on pulsed laser ablation in liquid (PLAL) to synthesize Janus-like Au-Ni-oxides and Au-Co-oxides nanoparticles and investigate the critical influence of ablation sequence on their properties. Comprehensive structural characterization, including XRD, TEM/HRTEM, XPS, and XAS, revealed that the resulting nanostructures are not core-shell but rather Janus-like, consisting of metallic Au, transition-metal oxides, and minor Au-Ni or Au-Co alloy phases. We demonstrate that the ablation order dictates the resulting phase distribution: Au ablated into a pre-existing Ni suspension (Au_in_Ni) produces Au-Ni alloy/NiO interfaces, whereas Ni ablated into a preexisting Au suspension (Ni_in_Au) favors phase-separated Au and NiO domains. Similar trends were observed for the Au-Co systems. The structural differences directly correlate with tunable optical and magnetic behaviors. UV-vis absorption spectroscopy showed that the Au plasmon resonances are broadened and red-shifted in the oxide-rich Au-in-Ni and Au-in-Co systems, but remain sharper and closer to pure Au in the phase-separated Ni-in-Au and Co-in-Au samples. Magnetic measurements at 5 K revealed an exceptionally strong magnetic hardening in the Au-in-Ni sample (Hc= 2130 Oe, Hex= -881 Oe), which surpasses conventional Ni/NiO systems due to robust pinning at the Au-Ni/NiO interfaces. In contrast, the Au-Co systems exhibited lower coercivity (220-571 Oe) and bias fields (-120 to -260 Oe), consistent with the properties of the cobalt oxide phase. These findings highlight that the interplay of oxidation chemistry and ablation sequence governs the structural, optical, and magnetic properties of these bimetallic nanoparticles and demonstrate the unique potential of PLAL for engineering hybrid plasmonic-magnetic heterostructures with tunable exchange anisotropy
Moduler la prise de raquette pendant l’imagerie motrice influence la précision et la performance du service en tennis : une étude pilote
No full textInternational audienceThere is now ample evidence that Motor Imagery (MI) contributes to improve motor performance. Previous studies provided evidence that its effectiveness remains dependent upon specific guidelines and recommendations. The body posture, as well as the context in which MI is performed, are notably critical and should be carefully considered. The present study in young tennis players (n=18) was designed to compare the effectiveness of performing MI of the serve while adopting a loose grip (congruent MI) or holding tightly and squeezing hard the racket (incongruent MI). Data revealed that both MI conditions contributed to enhance the number of successful serves (p<0.001) and the technical quality of the serve (p<0.001). Interestingly, comparing mean serve accuracy scores showed that performance gains were significantly higher in the loose MI group than in the tight MI group (p<0.02). These findings confirm the critical importance of the congruence between the content of the mental representation and the features of the corresponding actual movement. Overall, the present study further highlights the effectiveness of the loose grip while mentally rehearsing the serve, and might thus contribute to update and adjust specific MI guidelines and recommendations.La contribution de l’imagerie motrice (IM) à l’amélioration des performances est désormais bien établie, bien qu’assujettie à des préconisations d’usage et consignes de pratique spécifiques. En particulier, la position et le contexte dans lequel l’IM est effectuée exercent une influence sur sa qualité et son efficacité. L’objectif de cette étude chez de jeunes joueurs de tennis (n=18) était de comparer l’efficacité de deux conditions d’imagerie motrice (IM) : une condition compatible où le joueur imagine son service en tenant la raquette de manière relâchée (IM de relâchement), et une condition incompatible où il imagine tenir la raquette fermement pour créer une tension musculaire (IM de contraction). Les données ont montré que les deux conditions d’IM contribuaient à améliorer le taux de réussite (p<0.001) et la qualité technique du geste de service (p<0.001). En revanche, le score de précision moyen du service était significativement plus élevé après l’IM de relâchement (p<0.02), confirmant l’importance de la compatibilité entre contenu des représentations mentales et exigences de la pratique réelle. Ces données soulignent ainsi l’efficacité du relâchement de la main et permettent d’affiner les consignes liées au travail mental chez les jeunes joueurs de tennis
Leviers féministes contre un rapport néfaste au corps chez les jeunes femmes
No full textThis study of the relationship to the body of young women questions feminism as a lever of resistance to the effects of at least the most deleterious of the commandments to have a «perfect» female body. Indeed, the many aesthetic injunctions so that they comply with standards of weight and appearance are widely spread through dietary modes often related to fitness activities in the gym or on social networks. In peer groups, the male gaze also weighs on social interactions. From this point of view, the recent movements #metoo and #balancetonporc constitute an ideological break conducive to the dissemination of more egalitarian representations within the young generation, including young men. Between the persistence of gender role models and the emergence of their subversion by feminism, the contemporary period presents the interest of a more resilient social context for young women.en français : Cette étude du rapport au corps des jeunes femmes interroge le féminisme comme levier de résistance aux effets au moins les plus délétères des commandements à avoir un corps féminin « parfait ». En effet, les nombreuses injonctions esthétiques afin qu'elles se conforment à des standards de poids et d'apparence se diffusent largement à travers les modes alimentaires souvent liées à des activités de fitness en salle ou sur les réseaux sociaux. Dans les groupes de pairs, le regard masculin pèse aussi sur les interactions sociales. De ce point de vue, les récents mouvements #metoo et #balancetonporc constituent une rupture idéologique propice à la diffusion de représentations plus égalitaires au sein de la jeune génération, y compris chez les jeunes hommes. Entre persistance des modèles de rôles de genre et émergence de leur subversion par le féminisme, la période contemporaine présente l'intérêt d'un contexte social plus résilient pour les jeunes femmes.</div
Umm al-Quwain 2, un site d'habitat et une nécropole aux Emirats arabes unis
No full textInternational audienceThis volume examines the Neolithic period in Eastern Arabie, focusing on the coastal of UAQ2 in Umm Al Quwain, United Arab Emirates. Bosed on years of excavations and surveys conducted by the French Archaelogical in the UAE, it explores how coastal sites lived and adapted between the 8th and the 5th Millenia before present. The book highligts the unique features of UAQ2, including its well preserved stratigraphy, which also provides insights into settlement patterns, substance strategies and burial practicies. These findings offer a detailed understanding of how these communites sustained themseleves through fishing, huntingh, and herding. The site contains one of the oldest known graveyard in the Arabien Gulf, revealing evidence of inter-group vlolence and symbolic practices linked to to ancient pearling traditions. In addition to examinig local practises, this monograph places UAQ2 withing broader regional networks. It explores connections with Mesopotamia, demonstated by Ubaid pottery, and links with the Sultanate of Oman, reflected inshare material culture and technologies. These interactions underline the UAE's significant place in regional exchange during the Neolithic. The study also considers the impact of environnemental changes on human mobility and settlement, including the effects of aridification and schifting coastal landscape. By integrating archaeological and enviromental analyses, this book enhances our understanding of the Neolithic and its place within the the wider prehistoric world.Ce livre porte sur le Néolithique en Arabie orientale, en se concentrant sur le site côtier d'UAQ2 à Umm Al Quwain, aux Émirats arabes unis. S'appuyant sur les résultats d'années de fouilles et de prospections menées par la mission archéologique française aux Émirats arabes unis, on y explore la manière dont les populations côtières ont vécu et se sont adaptées entre le 8e et le 5e millénaire avant notre ère dans la région. L'ouvrage met en lumière les caractéristiques uniques d'UAQ2, notamment sa stratigraphie bien préservée, qui apporte des informations précieuses sur les modes d'occupation du territoire, les stratégies de subsistance et les pratiques funéraires. Ces découvertes offrent un éclairage nouveau sur la manière dont les communautés subsistaient grâce à la pêche, la chasse et l'élevage. Le site comporte l'une des plus anciennes nécropoles connues du Golfe Persique, révélant des témoignages de tensions intergroupes et de pratiques symboliques liées aux traditions perlières. Outre l'étude des pratiques locales, cette monographie situe UAQ2 au sein de réseaux régionaux. Elle explore les liens avec la Mésopotamie, mis en évidence par la céramique Obeid, comme les liens avec le Sultanat d'Oman, reflétés par un partage de la culture matérielle et des technologies. Ces interactions soulignent le rôle important des Émirats arabes unis dans les échanges régionaux au Néolithique. L'étude porte également sur l'impact qu'ont eu les changements environnementaux sur la mobilité des populations (effets de l'aridification et de de la transformation du paysage côtier). En intégrant les résultats d'analyses archéologiques et environnementales, cet ouvrage enrichit notre compréhension du Néolithique et de sa place dans le monde préhistorique