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Les livreurs des plateformes : travailleurs migrants, travail populaire dans le cœur des métropoles
No full textInternational audienceJournée d'études « Réfugiés et migrants : histoire.s, géographie.s » de l'APHG Pays de la Loire, Angers, 8 février 202
Synthetic learning: a novel approach for segmenting structures in children brains with perinatal stroke
No full textSegmenting cerebral structures with stroke lesions from paediatric MRIs is crucial for studying pathological neurodevelopment. Deep learning-based methods produce reliable predictions on typically developing brains. However, supervised models often fail to generalise to distorted anatomies due to a lack of annotated brains with stroke. They may also demonstrate reduced accuracy when tested on younger populations or unseen datasets. This study investigates the use of synthetic learning for the whole-brain segmentation task using cerebral MRIs of children with stroke in a multi-site configuration. To this end, we propose to generate synthetic data using publicly available whole-brain label maps from both typically developing children and children with brain distortions. Stroke is simulated by integrating augmented lesion masks on the label maps, which are first registered on a brain template. Synthetic images are then generated with random intensity values for each brain structure. We compare synthetic learning with supervised learning on real data using a U-net based segmentation model (nnU-net). The experimental results demonstrate that the proposed method enables accurate segmentation of the basal ganglia and stroke lesions in paediatric data, achieving mean DICE scores of 0.74 and 0.80. Notably, synthetic learning with prior lesion masks augmentations outperforms training on real data for stroke lesion segmentation, with a 4.1% improvement. The proposed method can accurately segment cross-site data without retraining. These findings underscore the potential of synthetic data to address the scarcity of paediatric medical imaging. Reliable segmentation of paediatric stroke brains could significantly enhance morphometric analysis pipelines
La mise en récit des compétences vertes : Une analyse du storytelling des étudiants-entrepreneurs
No full textInternational audienceA mi-chemin entre le marketing et les ressources humaines, cette recherche s’inscrit dans un contexte où la dimension « verte » s’invite dans nombre de projets entrepreneuriaux. Elle a pour objectif d’explorer la manière dont les étudiants-entrepreneurs mettent en récit leurs compétences vertes lorsqu’ils communiquent sur leur projet. Cinq projets ont fait l’objet d’une analyse netnographique (sites Internet et réseaux sociaux). Les résultats mettent en évidence les dimensions des compétences vertes les plus prégnantes dans le storytelling et donnent lieu à une proposition de catégorisation des profils en fonction de la manière dont les entrepreneurs « racontent » leurs compétences vertes
Viscoélastométrie et sonorhéométrie
No full textInternational audienceLes tests viscoléastométriques (thromboélastométrie, thromboélastographie) et sonorhéométriques (TVE) sont des tests réalisés sur sang total, grâce à des appareils de biologie délocalisée. Ils permettent l'étude de la formation du caillot, sa stabilité à travers les interactions fibrine-plaquettes et sa rétraction et/ou lyse. Ils donnent des résultats cliniquement pertinents en moins de 20 minutes. Ils ont été étudiés essentiellement en chirurgie cardiaque, traumatologie, transplantation hépatique et obstétrique, dans le cadre de l'hémorragie du post-partum. Le niveau de preuve soutenant l'utilisation des TVE est variable selon les situations cliniques, et il est souvent difficile d'isoler l'impact spécifique des TVE de celui de l'algorithme de prise en charge globale auquel ils sont intégrés.</div
Fatty acid analysis in an estuarine fish species to assess the health status of hydrosystems impacted by eutrophication and multistressors
No full textInternational audienceThe originality of this research lies in the use of fish lipid markers, which highlights the importance of fatty acid profiles as biomarkers to evaluate the health status of estuarine systems subject to eutrophication or multistress. In the present paper, we developed an approach combining lipid class and fatty acid analyses on juvenile European flounder muscle, watershed geographic metrics and pollutant levels in sediments, to assess the ecological status of seven small estuaries mainly impacted by agricultural activities in the watersheds. The estuaries showed contrasted fatty acids compositions in flounder muscle. Marked differences in polyunsaturated fatty acid (PUFA) proportions, particularly docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA), reflected not only the state of cell membranes but also variations in the quality of food sources. High levels of PUFA were associated with better ecological conditions, while reduced PUFA availability was clearly linked to eutrophication and multistress. In addition, higher flounder lipid reserve content was clearly identified in the system highly impacted by fish farming, reflecting a contamination of the entire trophic chain by aquaculture waste.</div
Real‐Time PCR Helicobacter pylori Test in Comparison With Culture and Histology for Helicobacter pylori Detection and Identification of Resistance to Clarithromycin: A Single‐Center Real‐Life Study
No full textInternational audienceABSTRACT Background In our center, RT‐PCR was integrated as a routine method to diagnose Helicobacter pylori due to its higher availability after COVID‐19 pandemics. The objective of this study was to assess the feasibility and performance of systematically performed RT‐PCR for H. pylori detection and clarithromycin (CLA) resistance in a real‐life clinical practice. Materials and Methods One hundred consecutive patients underwent an upper digestive endoscopy during which at least four biopsies (two from the antrum and two from the corpus) were obtained for RT‐PCR and culture with antibiogram and four additional biopsies for histology. The results of H. pylori detection were compared among RT‐PCR, histology, and bacterial culture, and the results of CLA susceptibility were compared between culture‐based antibiogram and RT‐PCR. Results Out of 100 patients, 64 were positive for H. pylori by RT‐PCR, 66 by histology, and 53 by culture, with no statistically significant difference among the three methods ( p > 0.05). CLA resistance was found in 8 out of 45 patients (17.7%) by culture and in 12 out of 64 patients (18.7%) by PCR. In 8 H. pylori ‐positive patients by culture, the antibiogram could not be realized due to lack of viability of the strains. In one patient, after a double checking, discrepant results were observed, requiring a complementary molecular analysis by the French National Reference Center for Helicobacters, which confirmed the existence of a double population of H. pylori strains within biopsies, with and without CLA resistance. Conclusions Our study demonstrates that in real‐life clinical practice, RT‐PCR is feasible and comparable in the ability to detect H. pylori and its resistance to CLA to bacterial culture with antibiogram and histology. Given its rapidity and limited dependence on the operator's interpretation, it appears preferable to the other methods
Expression evaluated by digital image analysis techniques of PRAME more than MCM6 is associated with poor prognosis in neuroblastoma: A pilot study with 84 cases
No full textInternational audienceNeuroblastoma is a common childhood tumor originating from neural crest progenitors with variable clinical behavior. Despite improved overall survival, factors such as stage, histoprognosis, MYCN status, and age still influence outcome. MCM6 regulates DNA replication and contributes to cancer progression. PRAME, first identified in melanoma, also acts on cell replication, epithelial-mesenchymal transition, and cell migration and has been associated with poor outcomes in several cancers, including neuroblastoma, using molecular biology techniques. The study aims to investigate MCM6 and PRAME expression and prognostic roles in neuroblastoma. A retrospective study was conducted, which included data of 84 patients with neuroblastoma diagnosed between 2000 and 2022, sourced from the pediatric tumor registry. Patient's characteristics and prognostic tumor factors were collected. Expression of MCM6 and PRAME proteins was evaluated using digital image analysis techniques. Univariate and multivariate analyses were performed using Cox regression to assess the impact of protein expression on survival and their associations with these prognostic factors. A total of 84 children diagnosed with neuroblastoma were included. MCM6 and PRAME were associated with unfavorable histologies (p = 0.03). PRAME was associated with bone marrow metastases (p < 0.01), high mitotic-karyorrhectic index (p = 0.04), and poor histoprognosis (p < 0.01). PRAME and MCM6 expression was correlated with several neuroblastoma prognostic factors. PRAME was significantly (p = 0.05) associated with poor event-free survival (EFS) and not significantly (p = 0.08) associated with overall survival (OS). Although statistical significance was not reached in multivariate analysis, the trends strongly suggested that the overexpression of MCM6 and PRAME was correlated with decreased survival
From Blood to Maps: The Contribution of Sealers and Whalers to the Exploration of the Crozet and Kerguelen Archipelagos (1850s–1930s)
No full textInternational audienceIn 2016, M. Pearson published a paper entitled “Charting the sealing islands”. The author reviews the contribution of sealing hunters to the official and unofficial charting of the islands of the Southern Ocean in the late 18th and early 19th centuries. He highlights that sealers, thanks to their practical skills, rediscovered islands that were misplaced on ocean maps and discovered new ones. He also points out that, though hunters may try to keep the discovery of new hunting grounds secret, to preserve their commercial interests, captains and shipowners were also sometimes proud to share their new geographical knowledge with others.We propose to extend these questions by looking at the role of sealers and whalers in improving coastal mapping of the subantarctic Crozet and Kerguelen islands, in the southern Indian Ocean, from the 1860s to the 1930s. Over this period, hunters sometimes ventured into the bays to catch whales. They also used to club or shot and butcher sea lions and elephant seals on the shore for their fur or blubber. However, the French sailor and explorer, Raymond Rallier du Baty, who carried out surveys of the Kerguelen Islands in 1908 and 1914, wrote: “during the past fifty years other ships had put into some of the bays, had made black rocks run with the blood of their victims, and had gone away without adding a word to the geographical records”. Indeed, approaching these islands remains dangerous, as evidenced by the numerous wrecks. However, American, French and Norwegian whalers and sealers contributed, in their own way, to the exploration of coasts and to the gradual disappearance of dotted coastal lines on maps. This is what we demonstrate from the various sources we use in this paper: French ministerial archives, newspapers and autobiographical accounts of sailors and hunters who explored the Kerguelen and Crozet islands.En 2016, M. Pearson a publié un article intitulé « Charting the sealing islands ». L'auteur revient sur la contribution des chasseurs de phoques à la cartographie officielle et officieuse des îles de l'océan Austral à la fin du XVIIIe siècle et au début du XIXe siècle. Il souligne que les chasseurs de phoques, grâce à leurs compétences pratiques, ont redécouvert des îles mal placées sur les cartes océaniques et en ont découvert de nouvelles. Il souligne également que, bien que les chasseurs tentaient de garder secrète la découverte de nouveaux territoires de chasse, afin de préserver leurs intérêts commerciaux, les capitaines et les armateurs étaient parfois fiers de partager leurs nouvelles connaissances géographiques avec d'autres.Nous proposons de prolonger ces questions en examinant le rôle des chasseurs de phoques et de baleines dans l’amélioration de la cartographie côtière des archipels subantarctiques de Crozet et Kerguelen, dans le sud de l’océan Indien, entre les années 1860 et les années 1930. Au cours de cette période, les chasseurs s’aventuraient parfois dans les baies pour traquer des baleines. Ils abattaient également à coups de gourdin ou de fusil des otaries et des éléphants de mer sur le rivage pour leur fourrure ou leur graisse. Pourtant, le navigateur et explorateur français Raymond Rallier du Baty, qui a effectué des relevés des îles Kerguelen en 1908 et 1914, a écrit : « Depuis cinquante ans, d’autres navires sont entrés dans certaines baies, ont couvert les rochers noirs du sang de leurs victimes, et sont repartis sans ajouter un mot aux annales géographiques ». En effet, l’approche de ces îles reste dangereuse, comme en témoignent les nombreux naufrages. Cependant, les baleiniers et les phoquiers américains, français et norvégiens ont, à leur manière, contribué à l’exploration des côtes et à la disparition progressive des lignes côtières en pointillés sur les cartes. C’est ce que nous démontrent les différentes sources que nous utilisons dans cet article : Archives ministérielles françaises, journaux et récits autobiographiques de marins et de chasseurs ayant exploré les îles Kerguelen et Crozet
Evaluating the effect of viral posts on social media engagement
No full textInternational audienceAs virality has become increasingly central in shaping information sources' strategies, it raises concerns about its consequences for society, particularly when referring to the impact of viral news on the public discourse. Nonetheless, there has been little consideration of whether these viral events genuinely boost the attention received by the source. To address this gap, we analyze content timelines from over 1000 European news outlets from 2018 to 2023 on Facebook and YouTube, employing a Bayesian structural time series model to evaluate the impact of viral posts. Our results show that most viral events do not significantly increase engagement and rarely lead to sustained growth. We identify two primary types of viral effects corresponding to different mechanisms of collective attention response. A 'loaded-type' virality manifests after a sustained growth phase, representing its final burst, followed by a decline in attention. A 'sudden-type' virality, with news emerging unexpectedly, reactivates the collective response process. Moreover, quick viral effects fade faster, while slower processes lead to more persistent growth. These findings highlight the transient nature of viral events and underscore the importance of consistent, steady attention-building strategies to establish a solid connection with the user base rather than relying on sudden visibility spikes.</div