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De quel droit ? Tensions et ambiguïtés dans le droit des étrangers
No full textLe droit des étrangers est au centre des politiques migratoires et suscite de nombreux débats où incompréhensions et tensions cohabitent. Ce dossier interroge les multiples missions du droit censé défendre les libertés fondamentales et protéger les étrangers de l’arbitraire, mais dont la mise en pratique renforce également des situations analysées ici sous l’angle de la discrimination et l’exception
A High-Resolution Brillouin Study of GeTe and Carbon-Doped GeTe Nanoscale Films: Implication for Thermoelectric and Memory Applications
No full textInternational audienceIn this work, we report the investigation of the acoustic guided modes in GeTe thin films with different microstructures and nanostructurations, interesting for thermoelectric and memory applications. Specifically, we have studied GeTe thin films where crystallization has been obtained through controlled annealing up to 400 and 450 °C, which induces different microstructures, and in a nanocomposite made of nanocrystals of GeTe surrounded by amorphous carbon, recently shown to exhibit glass-like thermal transport. We have performed a Brillouin scattering investigation on films of three different thicknesses per sample and on two different substrates for one of the samples. This has allowed us to estimate with good precision the two isotropic elastic constants and, from them, the bulk longitudinal and transverse sound velocities for the three samples. We observe that elastic constants are independent of the annealing temperature and microstructure in GeTe, while for the nanocomposite, a stiffening is found, in agreement with the estimation of the effective medium elastic moduli following the Reuss approximation. Finally, we extracted the intrinsic phonon attenuation for the Rayleigh mode, showing a much smaller attenuation in the nanocomposite. This has been interpreted as the consequence of a smaller roughness (finer microstructure, better interfaces) and a smaller anharmonicity in the nanocomposite. This latter finding confirms previous results and could be possibly related to a modification of the Peierls distortion in GeTe for nanometric grains, calling for further investigations
Déglutir la violence : phénomènes subjectifs et stratégies de gestion pour les professionnels oeuvrant à son contact
No full textInternational audienceMayotte has faced numerous challenges for years. Misery and insecurity impact daily life for both victims and witnesses. We propose a study on the subjective consequences of violence exposure, particularly among forensic experts and criminological researchers. Despite differing aims and methods, contact with violence may produce similar effects, studied within a complementary and metacultural framework. Mayotte’s intercultural context prompts us to rethink professionals’ perspectives on violence. We propose a plural approach focusing on researchers’ counter-transference and forensic field experiences. Results highlight the significance of group membership and identification in evaluating violence, which can influence professionals’ positioning and emotions. This research suggests that systematized introspection and multidisciplinarity can enhance understanding of these subjective dynamics and help mitigate biases
Traiter des manuscrits endommagés par le feu grâce à l’augmentation de données par intelligence artificielle: le cas du ms. L.II.14 de Turin (T)
No full textInternational audienceAutomatic recognition of handwritten text is a fundamental step in digital humanities for creating corpora and analyzing texts. Typically, for documents with regular scripts and standard layouts, high recognition accuracy above 95% is achievable. However, these success rates drastically decline when dealing with damaged documents, often resulting in significant content loss or making portions of the page difficult to decipher. Paleographers and philologists can often infer potential readings based on their expertise and knowledge of textual traditions. Nonetheless, with automatic document recognition, information loss severely impacts both the detection of content and readability. This study focuses on analyzing the layout of a burned document, specifically the manuscript L.II.14 from Turin. Experimental results using generative neural networks demonstrate demonstrate a 69-percentage point improvement in identifying content areas compared to traditional handwritten text recognition (HTR) models. This enhanced pipeline not only advances computational processing of damaged historical documents but also opens new avenues for document reconstruction.</div
Advanced thin film high entropy alloys with tunable mechanical properties
No full textInternational audienceHigh entropy alloys thin films (HEA-TFs) recently gained attention due to their combination of mutually exclusive properties such as high strength, ductility, and thermal stability [1]. However, a fine control over the microstructural features of HEAs-TF is still an open challenge, requiring the implementation of new nanoengineering strategies.In this context, pulsed laser deposition (PLD) was employed for the synthesis of CoCrCuFeNi HEA-TFs with nanosized grains and a wide range of microstructures such as compact and nanogranular, obtained simply by controlling the background pressure during deposition (from 2*10-3 up to 10 Pa). These HEA-TFs show a high hardness (~11 GPa), which is higher than sputter-deposited counterparts (hardness ~8.3 GPa) and other literature results due to the small domain size (from 38 to 12 nm), leading to Hall-Petch strengthening. Micropillar compression tests reveals high yield strength, up to 2.0 GPa, without sacrificing plastic deformability (no fractures at 30% compression). Nanogranular films show high thermal stability due to the cluster assembled structure and the lattice distortion of HEAs, with grain growth starting from 47% of Tmelt (370°C).The second nanoengineering strategy consists on the synthesis of Al/Alx(CoCrCuFeNi)100-x nanolaminates (NLs) with semi-coherent (FCC/FCC, x=0%) and incoherent (FCC/BCC, x=25%) interfaces, aiming to block the propagation of dislocations to improve hardness and yield strength [2]. This was achieved by controlling the bilayer period (Λ), from 400 nm down to 2.5 nm to further hinder cross-layer dislocation propagation. Among the main results, in situ micropillar compression tests show that incoherent interfaces have a greater capability to improve yield strength (up to 2.2 GPa), while showing great plastic deformability, with no appearance of cracks even at >30% deformation.REFERENCES[1] Zou Y., Nanocrystalline High-Entropy Alloys: A New Paradigm in High-Temperature Strength and Stability, Nano letters, Vol. 17, 2017.[2] Sàenz-Trevizo A., Hodge A. M., Nanomaterials by design: a review of nanoscale metallic multilayers, Nanotechnology, Vol 31, 2020
Voir et pouvoir et mouvoir. Sur deux documentaires du Master en Documentaire de création de l’UPF : Demonstration (2013) et Informe general II. El nuevo rapto de Europa (2015)
No full textInternational audienceLes films Demonstration (2013) et Informe general II. El rapto de Europa (2015) ont été développés au sein du Master en Documentaire de création de l’Université Pompeu Fabra. Comme de nombreux films documentaires réalisés au cours de cette période marquée par les répercussions des crises bancaires et financières de 2008, ils font voir et entendre les pratiques contestataires et les revendications de citoyens espagnols et participent au renouvellement des représentations. Dans cet article, nous avons souhaité interroger les régimes de visibilité d’un ensemble d’institutions économiques et culturelles apparaissant dans ces deux longs-métrages. Dans le partage de regards que proposent ces films, quels points de vue ces œuvres portent-elles sur les productions et les politiques publiques culturelles ? Dans quelle mesure ces films, dans leur diversité, peuvent-ils être porteurs de changement
Boron and phosphorus doped diamond: change in the electronic structure post exposure to low pressure deuterium plasma and its effect on the production of negative ions
No full textInternational audienceNegative ion production is of significant interest for materials processing and neutral beam injection systems for magnetic confinement fusion reactors. The surface production mechanism can be required for high current applications. Dielectric materials, including doped diamond, are of interest for increasing surface production as a potential alternative to low-work function metals and further understanding of the underpinning mechanisms is needed. In this study we use photoemission yield spectroscopy, in conjunction with the Fowler model and mass spectrometry, to measure the negative ion yield and ionization threshold of micro-crystalline diamond ( µ c-D), micro-crystalline boron doped diamond ( µ c-BDD) and single crystal phosphorus doped diamond (PDD) under deuterium plasma exposure at sample temperatures between 30 ∘ C and 700 ∘ C. We observe that deuterium plasma exposure of PDD at 400 ∘ C reduces its ionization threshold from approximately 4.0 eV to 2.1 eV, which is similar to the work function of cesium. While the ionization threshold of diamond is observed to be sensitive to sample temperature and the dopant used, this appears to have negligible effect on negative ion production. Developing a better understanding of which material properties are most significant for negative ion production will assist the development of improved negative ion sources
The gut microbiome connects nutrition and human health
No full textInternational audienceThe gut microbiome has an undeniable role in mediating the health effects of the diet, given its ability to co-digest nutrients and influence nutrient signalling to multiple organ systems. As a suboptimal diet is a major risk factor for and contributor to disease, understanding the multidirectional interactions between the food we eat, the gut microbiome and the different body organ systems is crucial from a public health perspective. Indeed, this research area is leading to the refinement of nutritional concepts and strategies to optimize health through diet. In this Review, we provide an update on how dietary patterns and food intake shape gut microbiome features, the mode of action of diet-microorganism interactions on the immune, nervous and cardiometabolic systems and how this knowledge could explain the heterogeneity of dietary responses, and support food-based dietary guidelines and medical and precision nutrition. Finally, we discuss the knowledge gaps and research efforts needed to progress towards the integration of microbiome science with more precise dietary advice to leverage the role of nutrition in human health
Table ronde Protection des forêts : quel chemin parcouru depuis les peintres de Barbizon ?
No full textInternational audienc
Perceptions regarding long-acting pre-exposure prevention (PrEP) among female sex workers and men having sex with men in San Pedro and Abidjan, Côte d’Ivoire
No full textInternational audienceBACKGROUND: Demonstration studies showed that oral PrEP use and adherence can be complex among some populations, such as Female Sex Workers (FSWs) and men who have sex with men (MSM), especially due to their high mobility, unpredictable daily life or side effects. In this context, long-acting PrEP (currently at different stages of development), such as injectables, gel, implants, vaginal suppositories, vaginal/anal douching, or vaginal rings, may overcome some difficulties encountered with oral PrEP. This study aimed to explore the perceptions of these long-acting formulations among FSWs and MSM in Côte d’Ivoire.METHODS: Embedded within the ANRS 12381 PRINCESSE project, this qualitative sub-study was conducted in November-December 2023 within two community NGOs: Aprosam in San Pedro and Espace Confiance in Abidjan (FSWs and MSM). Overall, 32 FSWs (19 PrEP-naïve and 13 PrEP-experienced) and 12 MSM (3 PrEP-naïve and 9 PrEP-experienced) were interviewed (14 individual interviews, 5 focus groups). A thematic analysis focused on practicality, discretion, autonomy/self-sufficiency, perceived efficacy, and anticipated side effects of the different formulations.RESULTS: Participants generally expressed favorable views toward long-acting PrEP, considered a less restrictive form than oral PrEP. Injections were particularly appreciated for discretion (no visible mark), with six-monthly injections preferred. Some concerns were expressed about injection pain. The gel, likened to a lubricant, was appealing for its dual protective and pleasurable function. However, some participants shared doubts about its effectiveness. Although the implant's long-acting time (1 year) was appreciated, they were not plebiscite due to a lack of discretion (scar) and anticipated potential side effects. The autonomy and ease of use associated with vaginal suppositories were seen as advantageous, provided optimal hygiene conditions were met; the MSM drew a parallel with anal suppositories. Even though vaginal douching is widely practiced among FSWs, the intimate cleansing PrEP lotion received mixed reactions among them due to awareness of the risks of overuse. Lastly, the vaginal ring garnered little interest due to unfamiliarity with the product.CONCLUSIONS: Overall, long-acting PrEP may offer alternative options for HIV prevention. Key elements include being easy to use, simplified follow-up (less often as possible), clear rules for start/stop, discretion, perceived effectiveness, and anticipated side effects