Weakly supervised segmentation of polyps on colonoscopy images

openIl cancro del colon-retto (CRC) è una delle principali cause di morte a livello mondiale e continua a rappresentare una sfida critica per la salute pubblica, richiedendo una precisa e tempestiva diagnosi e un intervento mirato. La colonscopia, ovvero l'esame diagnostico volto a esplorare le pareti interne del colon per scoprire eventuali masse tumorali, ha dimostrato essere un metodo efficace per ridurre l'incidenza di mortalità. Le tecniche emergenti, come l'analisi avanzata delle immagini tramite reti neurali, sono promettenti per una diagnosi accurata. Tuttavia, alcuni studi hanno riportato che, per varie ragioni, una certa percentuale di polipi non viene rilevata correttamente durante la colonscopia. Una delle più importanti è la dipendenza dalle annotazioni a livello di pixel, che richiede molte risorse computazionali; per questo si rendono necessarie soluzioni innovative. Questa tesi introduce alcune strategie per migliorare l'identificazione dei polipi. A tal fine, le tecniche principali utilizzate coinvolgono i cosiddetti metodi di Explainable AI per l'analisi delle mappe di salienza e di attivazione, attraverso diversi algoritmi di rilevamento della salienza visiva e la Gradient-weighted Class Activation Mapping (Grad-CAM). Inoltre, viene utilizzata una rete neurale per la segmentazione con architettura DeepLabV3+, in cui vengono fornite le bounding box sulle immagini di addestramento, in un contesto debolmente supervisionato.Colorectal cancer (CRC) is one of the leading causes of death worldwide and continues to pose a critical public health challenge, demanding precise early detection and intervention. Colonoscopy, the diagnostic examination aimed at exploring the inner walls of the colon to discover any tumour masses, is an effective method to decrease mortality incidence. Emerging techniques, such as advanced image analysis driven by neural networks, hold promise for accurate diagnosis. However, studies have reported that, for various reasons, a certain percentage of polyps are not correctly detected during colonoscopy. One of the most important is the dependency on pixel-level annotations, which requires a lot of computational resources, making necessary innovative solutions. This thesis introduces strategies for improving polyp identification. For this purpose, the main techniques involve the so-called Explainable AI tools for analyzing saliency maps and activation maps, through several state-of-the-art visual saliency detection algorithms and Gradient-weighted Class Activation Mapping (Grad-CAM). In addition, a neural network for segmentation with DeepLabV3+ architecture is used, in which bounding boxes are provided on the training images, within a weakly supervised framework

Tree-visibility orders

AbstractWe introduce a new class of partially ordered sets, called tree-visibility orders, containing interval orders, duals of generalized interval orders and height one orders. We give a characterization of tree-visibility orders by an infinite family of minimal forbidden suborders. Furthermore, we present an efficient recognition algorithm for tree-visibility orders

Global Constraint Catalog, 2nd Edition

This report presents a catalogue of global constraints where each constraint is explicitly described in terms of graph properties and/or automata and/or first order logical formulae with arithmetic. When available, it also presents some typical usage as well as some pointers to existing filtering algorithms

Global Constraint Catalog, 2nd Edition (revision a)

This report presents a catalogue of global constraints where each constraint is explicitly described in terms of graph properties and/or automata and/or first order logical formulae with arithmetic. When available, it also presents some typical usage as well as some pointers to existing filtering algorithms

Tracing the glycogen cells with protocadherin 12 during mouse placenta development.

International audienceAmong the different trophoblast subtypes of the mouse placenta, the glycogen cells (GC) are one of the trophoblast subtypes that invade the decidua. We previously established that GC specifically expressed protocadherin 12 (PCDH12). In this paper, we investigated the origin of the PCDH12-positive cells and we characterized their fate in the maternal tissues. Our data indicate that they directly originate from the central part of the ectoplacental cone at embryonic day (E) 7.5. PCDH12-positive cells start to accumulate glycogen from E10.5 and the first migrating cells could be observed from this age. Unlike other placental and decidual cells, GC do not express P-cadherin, which may explain their migration properties in this organ. In the decidua, GC settle in the vicinity of the maternal vascular sinuses but do not incorporate in the endothelium. By the end of gestation (E17.5), most GC islets of the decidua enter into a lytic phase and form large lacunae. These lacunae, filled with glycogen, may provide a substantial source of energy at the end of gestation or during delivery. Our data suggest that spongiotrophoblasts and GC are two independent lineages and we bring insights into GC migration and fate

Reconstruction of Finite Truncated Semi-Modular Lattices

AbstractIn this paper, we prove reconstruction results for truncated lattices. The main results are that truncated lattices that contain a 4-crown and truncated semi-modular lattices are reconstructible. Reconstruction of the truncated lattices not covered by this work appears challenging. Indeed, the remaining truncated lattices possess very little lattice-typical structure. This seems to indicate that further progress on the reconstruction of truncated lattices is closely correlated with progress on reconstructing ordered sets in general

Escola de Programação de Computadores para crianças e adolescentes

Anais do 35º Seminário de Extensão Universitária da Região Sul - Área temática: EducaçãoO aprendizado sobre programação de computadores permite que crianças e adolescentes aprendam a trabalhar de forma colaborativa e a pensar de forma sistemática na solução de problemas. Entretanto, no Brasil há uma carência pelo ensino de programação nas escolas de Ensino Fundamental e isso resulta no desinteresse pelo tema. Este projeto de extensão teve como objetivo ensinar programação de computadores para crianças e adolescentes do Ensino Fundamental das escolas de Fraiburgo - SC. Foram utilizadas ferramentas educativas durante as oficinas de programação e robótica. Participaram 65 alunos e os resultados apresentam evidências de que a metodologia de ensino e as ferramentas utilizadas facilitaram a aprendizagem e tornaram o processo divertid

Vincent Goulet, Christoph Vatter, dirs, Champs médiatiques et frontières dans la « Grande Région » SaarLorLux et en Europe/Mediale Felder und Grenzen in der Großregion SaarLorLux und in Europa

Les textes de ce livre prennent place dans un objectif large de compréhension des modes de circulation transfrontalière des informations ou nouvelles médiatiques. Issu du programme de formation et recherche de la Maison des sciences de l’homme Lorraine « La circulation transfrontalière des informations médiatiques dans la grande Région » (Infotransfront), le contenu de ce travail à la fois collectif, bilingue et plurinational (France, Allemagne, Luxembourg et Suisse) vise à « situer la questi..