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Contribution to metrological corrections of a high spectral resolution mid infrared spectral imager
No full textInternational audienceMid-infrared spectral imaging is becoming increasingly attractive in various fields, from polymer analysis to vegetation monitoring. While conventional architectures such as push-broom systems are now commercially available, applications demanding high spectral resolution or tunability increasingly rely on laser-based illumination.However, coherent sources introduce metrological challenges, including speckle artifacts, intensity instabilities, and beam pointing fluctuations. This work presents correction strategies addressing these effects in a tunable laser imaging system with 10 nm spectral resolution, enabling accurate and reliable data acquisitio
Deep learning prediction of noise-driven nonlinear instabilities in fibre optics
No full textInternational audienceAbstract Machine learning is bringing revolutionary approaches into many fields of physics. Among those, photonics enables fast and scalable information processing. Photonics platforms further possess rich nonlinear dynamics that drive fundamental interest but also prove powerful for applications in computation, imaging, frequency conversion, source development and advanced signal processing. However, incoherent processes of nonlinear optics are hardly exploited in practice as the control of noise-driven dynamics remains challenging. Here, we exploit deep learning strategies and demonstrate that coherent optical seeding can effectively shape incoherent spectral broadening. We focus on the intricate interplay between weak coherent pulses and broadband noise, competing during nonlinear fibre propagation within an amplification process known as modulation instability. We demonstrate artificial neural networks’ capability to efficiently predict these complex incoherent dynamics, both numerically and experimentally. Our results show that input seed properties can be inferred from the incoherent output signal. Furthermore, our approach enables reliable prediction of output spectral fluctuations, paving the way to tailoring complex photonic signals with specific correlation features
« Sceller, signer, tamponner : la fabrique de l'identité (13e-20e siècle) », exposition des Archives départementales de la Charente [en ligne], La Source, Portail des Archives de la Charente
No full texthttps://lasource.archives.lacharente.fr/actualites/nouvelle-expo-virtuelle-74/n:298Exposition virtuelle numérique des Archives départementales de la Charente centrée sur la fabrique de l'identité des sceaux médiévaux aux titres d'identité contemporains. 6 catégories interrogent les acteurs produisant, attestant, contrôlant l'identité des individus à partir d'archives notables et exemplaires. Les notices de cette exposition, rédigées par Jean-Christophe Temdaoui et Albert Perles, analysent les particularités de ces pièces d'archives et en donnent le sens et la portée pour inscrire la construction de la fabrique de l'identité dans celle de l'Etat et des sociétés
L'épaisseur de l'expression. Niveaux de pertinence et vitesses du sens chez Jacques Fontanille
No full textInternational audienc
Les exergames pour aider les personnes âgées à rester actives
No full textInternational audiencePromouvoir l’activité physique (AP) dans le domaine de la santé est essentiel, en particulierpour les personnes âgées. Cependant, l’inactivité reste largement répandue, alimentée pardes barrières environnementales et sociales complexes. Les exergames – jeux vidéo actifsconçus pour encourager le mouvement en y ajoutant une dimension ludique – semblentprometteurs pour relever ces défis en incitant les utilisateurs à pratiquer une AP. En combinantactivités physiques et cognitives, ces technologies proposent des interventions innovantes,engageantes et personnalisables, adaptées aux besoins individuels. Des caractéristiques clés,comme le retour en temps réel sur les performances et l’ajustement des niveaux de difficulté,rendent ces outils particulièrement flexibles pour un large éventail d’utilisateurs. De nombreusesétudes montrent des effets bénéfiques dans plusieurs dimensions : physique (coordination,équilibre…), cognitive (fonctions exécutives, mémoire, attention…) et sociale (entraide, liensociaux, interaction…). Cependant, des recherches supplémentaires sont nécessaires pourmieux comprendre leurs mécanismes d’action et évaluer leurs effets spécifiques sur la santéet le bien-être. Les études actuelles restent principalement exploratoires, et les bénéfices réelsdes exergames doivent être confirmés par des travaux de recherche rigoureux. Comme lesoulignent des études antérieures, la conception soignée des programmes d’entraînementest essentielle pour garantir des résultats significatifs. Bien que l’avenir de ces technologiesdans les activités physiques adaptées semble prometteur, une évaluation et une optimisationcontinues sont nécessaires pour maximiser leur efficacité auprès des populations âgées
Does development of submucosal dissection models influence quality of training? Comparison of existing models
No full textInternational audienceUse of endoscopic submucosal dissection (ESD) is growing, but access to it remains limited. The aim of this study was to compare the performance of various existing models and the progress made by students on them. Four training models (bovine colon (ex-vivo), ex vivo porcine model, live porcine model, and an artificial model (Endogel)) were evaluated during a 1-week training course. Each participant was evaluated at the beginning (D1) and at the end of the training (D5). Learners performed a standardized ESD of 2 cm on the four models in a randomized order. Experts evaluated the ability of participants to perform ESD using the objective structured assessment of technical skill score (OSATS). Sixteen students were involved, the average age was 35.6 years (+/- 4.6) and they practiced endoscopy for 10 years (+/-5.3). The OSATS significantly increased in each model during the week, with mean scores increasing from 8.6 to 23.3, from 10.7 to 12.9, from 8.8 to 21.3 and from 8.2 to 12.5 for the bovine colon, ex vivo porcine model, live porcine model, and Endogel models, respectively. Ex-vivo models are good models for learning ESD skills. The bovine colon model seems to be the most discriminating. Synthetic models should be reserved for novices
ASO Author Reflections: Animal Models for Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) Research
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Prognostic factors of breast cancer and survival in Sub-Saharan Africa: A systematic review and meta-analysis
No full textInternational audienceBackground > Breast cancer is an escalating public health concern in Sub-Saharan Africa (SSA), where mortality rates remain disproportionately high despite lower incidence compared to Western countries. The combination of late-stage diagnoses, limited healthcare infrastructure, and socioeconomic inequalities severely compromises patient outcomes. Methods > We conducted a systematic review and meta-analysis of 85 studies encompassing 33,053 patients across SSA to characterize breast cancer profiles, focusing on age at diagnosis, cancer stage, molecular subtypes, and survival outcomes. Findings > The mean age at diagnosis was 48.7 years, notably younger than in high-income regions. Half of the patients were diagnosed at stage III, and only 4% at stage I. Luminal A was the most prevalent molecular subtype (30%), followed closely by triple-negative breast cancer (29%), known for its aggressive course and limited treatment options. Survival analysis revealed a pooled 5-year survival rate of 44%, with substantial regional disparities: survival was poorest in West Africa and comparatively better in East Africa and South Africa
Somewhat homomorphic encryption based on random codes
No full textInternational audienceWe present a secret-key encryption scheme based on random rank metric ideal linear codes with a simple decryption circuit. It supports unlimited homomorphic additions and plaintext multiplications (i.e. the homomorphic multiplication of a clear plaintext with a ciphertext) as well as a fixed arbitrary number of homomorphic multiplications. We study a candidate bootstrapping algorithm that requires no multiplication but additions and plaintext multiplications only. This latter operation is therefore very efficient in our scheme, whereas bootstrapping is usually the main reason which penalizes the performance of other fully homomorphic encryption schemes. However, the security reduction of our scheme restricts the number of independent ciphertexts that can be published. In particular, this prevents to securely evaluate the bootstrapping algorithm as the number of ciphertexts in the key switching material is too large. Our scheme is nonetheless the first somewhat homomorphic encryption scheme based on random ideal codes and a first step towards full homomorphism. Random ideal codes give stronger security guarantees as opposed to existing constructions based on highly structured codes. We give concrete parameters for our scheme that shows that it achieves competitive sizes and performance, with a key size of 3.7 kB and a ciphertext size of 0.9 kB when a single multiplication is allowed