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Circulating tumor DNA strongly predicts efficacy of chemotherapy plus immune checkpoint inhibitors in patients with advanced gastro-esophageal adenocarcinoma
No full textInternational audienceBackground Efficacy of 2nd line treatment in advanced gastric or gastro-esophageal junction (GEJ) adenocarcinoma remains limited with no identified strong predictor of treatment efficacy. We evaluated the prognostic value of circulating tumor DNA (ctDNA) in predicting the efficacy of immune checkpoint inhibitors (ICI) plus chemotherapy in the randomized PRODIGE 59-FFCD 1707-DURIGAST trial. Methods ctDNA was evaluated before treatment (baseline) and at 4 weeks (before the third cycle of treatment, C3) using droplet-digital PCR assays based on the detection of CpG methylation.Results Progression-free survival (PFS) and overall survival (OS) were shorter in patients with a high (>1.1 ng/mL) versus low (<1.1 ng/mL) ctDNA concentration at baseline (2.3 vs. 5.8 months; HR = 2.19; 95% CI, 1.09-4.41; p = 0.03 and 4.5 vs. 12.9 months; HR = 2.73; 95% CI, 1.29-5.75; p < 0.01), respectively, after adjustment for identified prognostic variables. Patients with a ctDNA decrease ≤75% between baseline and C3 versus a ctDNA decrease >75% had a worse objective response rate (p = 0.007), shorter PFS (2.2 vs. 7.4 months, HR = 1.90; 95% CI, 1.03-3.51; p = 0.04) and OS (6.6 vs 16.0 months; HR = 2.18; 95% CI, 1.09-4.37; p = 0.03). Conclusions An early decrease in ctDNA concentration is a strong predictor of the therapeutic efficacy of ICI plus chemotherapy in advanced gastric/GEJ adenocarcinoma. Clinical Trial Information NCT03959293 (DURIGAST).The prognosis of advanced gastric and gastro-esophageal junction (GEJ) adenocarcinoma remains poor, with overall survival (OS) ranging from 10% to 15% at 5 years 1 . In Human Epidermal Growth Factor Receptor-2 (HER2) negative unresectable advanced/metastatic tumors, the most frequently used first-line palliative chemotherapy is a doublet of fluoropyrimidine (5fluorouracil (5FU) or capecitabine) plus a platinum salt (cisplatin or oxaliplatin) 2,3 . Recently, the addition of docetaxel (TFOX regimen), immune checkpoint inhibitors (ICI, in PD-L1 positive tumors) and anti-claudin 18.</div
Nonlinear dynamics in breathing-soliton lasers
No full textInternational audienceWe review recent advances in the study of nonlinear dynamics in mode-locked fibre lasers operating in the breathing (pulsating) soliton regime. Leveraging advanced diagnostics and control strategies -- including genetic algorithms -- we uncover a rich spectrum of dynamical behaviours, including frequency-locked breathers, fractal Farey hierarchies, Arnold tongues with anomalous features, and breather molecular complexes. We also identify a novel route to chaos via modulated subharmonic states. These findings underscore the utility of fibre lasers as model systems for exploring complex dissipative dynamics, offering new opportunities for ultrafast laser control and fundamental studies in nonlinear science
Topological waves in acoustic lattices with chiral symmetry
No full textMatériaux poreux et métamatériaux acoustiques; GAPSUS - Acoustique Physique, Sous-Marine et Ultra-Sonore: GVB - Vibro acoustique et Contrôle du Bruit: GABE - Acoustique du Bâtiment et de l'EnvironnementNational audienceWe discuss a particular class of architectured materials, consisting in discrete lattices of acoustic waveguides. We discuss the exotic properties that emerge when the lattice is bipartite, or equivalently, has chiral symmetry, and it is combined with other spatial symmetries. Various combinations can lead to so-called topological phases. As a result, the system can display edge waves, or defect localized modes, with exotic and robust properties, characterized by a topological invariant. We focus on bilayered hexagonal lattices, and show that specific types of defect mode can appear. These modes are topologically protected, and possess an eigenfrequency insensitive to symmetry preserving random perturbations. After discussing the main properties of these topological defect modes theoretically, we present an experimental implementation of such systems using modular networks of tubes
Réduction du rayonnement acoustique de plaques et de coques à l’aide de microperforations
No full textVibro-acoustique : session générale; GVB - Vibro acoustique et Contrôle du BruitNational audienceLa réduction des vibrations et du bruit basse fréquence (BF) est un enjeu industriel, particulièrement pour les structures légères de faible épaisseur. Ainsi, les vibrations de plaques microperforées chargées par un fluide ont été étudiées théoriquement et expérimentalement. Ces structures dissipent de l’énergie grâce aux pertes thermo-visqueuses qui se produisent dans les couches thermo-visqueuses au niveau de la paroi solide des perforations. Cependant, l’impact des microperforations sur l’amortissement ajouté et les propriétés de rayonnement acoustique des plaques et des coques cylindriques reste peu étudié. Cette étude propose d’appliquer la théorie classique du rayonnement acoustique des plaques flexibles à des structures microperforées, en tenant compte du couplage fluide-structure et des dissipations visqueuses dans les couches limites des perforations. Le modèle vibratoire analytique des plaques microperforées, précédemment développé par les auteurs, est : i) utilisé pour déterminer le champ vibratoire des plaques microperforées ; ii) adapté pour obtenir le champ vibratoire des coques cylindriques microperforées. Les champs vibratoires ainsi obtenus permettent d'analyser le rayonnement acoustique des structures microperforées soumises à des excitations mécaniques et/ou acoustiques. Les résultats montrent une réduction significative du rayonnement acoustique des structures microperforées par rapport à leurs homologues non perforés. Les études numériques et expérimentales menées sur ces structures permettent de valider ces résultats. Ainsi, les microperforations apparaissent comme une solution prometteuse pour atténuer les vibrations BF et réduire le bruit associé
Enhanced olfactory performance in deaf Dalmatians: evidence for neurosensory compensation?
No full textCongenital deafness in dogs arises early in life and may lead to compensatory neuroplastic changes involving other sensory modalities. This study assessed whether deaf dogs exhibit enhanced olfactory performance compared to their hearing counterparts. A food search task conducted in a complex indoor environment was used to evaluate olfactory ability. Dogs were required to locate a single hidden kibble across progressively challenging hiding locations. After a learning phase, the evaluation focused on the most difficult conditions, where the kibble was neither visible nor accessible without olfactory guidance. Six purebred Dalmatians (three deaf, three hearing) were initially enrolled; two were excluded due to dropout or lack of motivation. All remaining dogs completed six training sessions before evaluation. Performance was measured as search speed (distance divided by search time), and group differences were analyzed using linear mixed-effects models. Deaf dogs demonstrated significantly higher search speeds than hearing dogs under the most demanding conditions (kibble hidden at a height), but not under simpler ones. No significant effect of time since last meal or interval between sessions was observed. These preliminary findings suggest a potential enhancement of olfactory performance in deaf dogs, possibly as a compensatory response to early auditory deprivation
A bi-directional cascaded transformer network for underwater narrowband signal enhancement
No full textInternational audienceThe narrowband components of ship-radiated noise are critical for the passive detection and identification of ship targets. However, the intricate underwater environment poses challenges for conventional acoustic signal processing methods, particularly at low signal-to-noise ratios. Previous studies have suggested the use of deep learning for denoising, but there is a significant lack of research on underwater narrowband signals. In response, this paper introduces a bi-directional cascaded transformer network (BCT-Net) with two branches simultaneously extracting features from target signals and ambient noise. Leveraging cascaded attention mechanisms, BCT-Net is able to detect narrowband features at signal-to-noise ratios as low as –20 dB. Through a frequency-guided attention module and bi-directional cross-attention-based interaction module, the BCT-Net excels in the extraction of the target features. This methodology enhances noise suppression by leveraging the interaction of features extracted from both the target and noise branches. Operating at a fine-grained level, the model reconstructs subtle frequency variations while ensuring the separation of the target signals and ambient noise. Ablation experiments underscore the unique contributions of each module, which together significantly enhance denoising performance. Our proposed BCT-Net surpasses the existing methods across various evaluation metrics, emphasizing its superiority when it comes to narrowband signal enhancement
Paysage et feuille de route nationale des infrastructures en lien avec les données d'observation
No full textNational audienceCette présentation introduit la session plénière "Offre de services nationale sur les données d'observation : état des lieux, vision et perspectives" du séminaire "Journées GEDEOP - SIST25". Elle donne le panorama des infrastructures de recherche en lien avec les données d'observation, sur la base de la feuille de route nationale "Stratégie nationale des infrastructures de recherche" du Ministère de l'Enseignement supérieur et de la Recherche (édition 2021, version 17/03/2022). Un focus est réalisé sur les infrastructures du domaine "Système Terre et de l'environnement" montrant leur interactions entre elles, et leurs liens avec l'écosystème international et national (Recherche Data Gouv)
Handicraft activities in the small town of Fanum Martis (Famars, noter France) : analysing and interpreting spatial organisation and production size
No full textInternational audienceRecent excavations (2011 to 2020) in the western part of the Roman small town of Fanum Martis, have enabled an overall understanding of its urban lay-out. The town develops economically from the second half of the 1st century onwards, when the nearby civitas capital Bavay decentralizes its handicraft activities, only keeping its administrative role. The small town expands to 200 hectares, with a large range of handicraft and agricultural activities mixed within the urban organization, not restricting them to a particular area. This includes alongside pottery activities, a tannery, bronze and glass production, glue manufacturing and treatment of cereals. These activities, sometimes lacking clear architectural features, have been proved by extensive sampling of artefacts and raw materials, using petrography, carpology, archaeozoology or micromorphological studies to sustain hypotheses. Differences in production size can be noted for pottery manufacturing, using two types of organization: simple workshops with a repertoire of cooking-wares meant to be sold within the town and the pagus and worksites where a range of kilns and buildings suggest an extensive activity for a large distribution of mortaria and flagons to the north of Gallia Belgica. This production probably cannot be seen apart from the nearby agricultural activities, flagons being exported for their contents.The article wishes to illustrate this rich variety of handicrafts, their architectural features but also their lay-out within the urban plan and the analysis of their production size, using the first results of distribution data. Finally, analysis of artefacts themselves lead to a list of probable professions mixing within the same living space (goldsmiths, doctors, horners, …). Thus, a complex image is yielded of a flourishing town where living and producing go hand in hand
Ancestralité et autochtonie. Une recherche pluridisciplinaire sur la mémoire des origines
No full textInternational audienceComment la mémoire des origines participe-t-elle à la construction des identités et des territoires ? Cette interrogation, qui traverse les individus et les sociétés dans la longue durée, est abordée dans ce volume en questionnant le rapport aux origines autour de deux formes d’appartenance : l’ancestralité (comme rapport aux origines familiales) et l’autochtonie (comme rapport aux origines géographiques). La problématique de la mémoire des origines, parce qu’elle associe une analyse critique de la notion d’origine et une réflexion sur l’expression spatiale des identités individuelles et collectives, nécessite une approche résolument pluridisciplinaire. L’ouvrage regroupe ainsi les contributions d’historiens spécialistes des différentes périodes, d’archéologues, d’anthropologues, de politistes et de juristes afin de confronter les concepts et les méthodes autour d’un objet partagé. Ce choix a permis de multiplier les contextes d’analyse — avec une attention particulière portée aux enjeux de mémoire liés au fait colonial (antique, moderne et contemporain) — et de confronter différentes manières de faire vivre cette mémoire des origines, à travers des mots, des objets, des lieux
