Geometric deep learning for polygonal mesh denoising

Il seguente lavoro si propone come analisi degli operatori convoluzionali che caratterizzano le graph neural networks. ln particolare, la trattazione si divide in due parti, una teorica e una sperimentale. Nella parte teorica vengono innanzitutto introdotte le nozioni preliminari di mesh e convoluzione su mesh. In seguito vengono riportati i concetti base del geometric deep learning, quali le definizioni degli operatori convoluzionali e di pooling e unpooling. Un'attenzione particolare è stata data all'architettura Graph U-Net. La parte sperimentare riguarda l'applicazione delle reti neurali e l'analisi degli operatori convoluzionali applicati al denoising di superfici perturbate a causa di misurazioni imperfette effettuate da scanner 3D

Predictive response-relevant clustering of expression data provides insights into disease processes

This article describes and illustrates a novel method of microarray data analysis that couples model-based clustering and binary classification to form clusters of ;response-relevant' genes; that is, genes that are informative when discriminating between the different values of the response. Predictions are subsequently made using an appropriate statistical summary of each gene cluster, which we call the ;meta-covariate' representation of the cluster, in a probit regression model. We first illustrate this method by analysing a leukaemia expression dataset, before focusing closely on the meta-covariate analysis of a renal gene expression dataset in a rat model of salt-sensitive hypertension. We explore the biological insights provided by our analysis of these data. In particular, we identify a highly influential cluster of 13 genes-including three transcription factors (Arntl, Bhlhe41 and Npas2)-that is implicated as being protective against hypertension in response to increased dietary sodium. Functional and canonical pathway analysis of this cluster using Ingenuity Pathway Analysis implicated transcriptional activation and circadian rhythm signalling, respectively. Although we illustrate our method using only expression data, the method is applicable to any high-dimensional datasets

Simmetrizzazione di Steiner e disuguaglianza isodiametrica

Utilizzando la simmetrizzazione di Steiner dimostriamo la disuguaglianza isodiametrica. Come applicazione, mostriamo l'equivalenza tra la misura di Lebesgue e la misura di Hausdorff n-dimensionali di un insieme di R^n. Infine, dimostriamo che la palla è l'unico sottoinsieme di R^n che verifica l'uguaglianza nella disuguaglianza isodiametrica

Discrepant ratios of arterial vs. venous thrombosis in hemophilias A and B as compared to FVII deficiency

Background: The occurrence of a thrombotic event in congenital bleeding disorders has drawn considerable attention in recent years. Both patients with hemophilia and patients with von Willebrand disease and even those with rare coagulation disorders have been shown to present occasional thrombotic events. Little is known on the comparative prevalence of arterial vs. venous thrombosis in these patients. Objectives: The purpose of the present investigation was to evaluate the prevalence of arterial vs. venous occlusions in hemophilia A and B vs. FVII de\ufb01ciency. Methods: A time unlimited search of the literature was carried out using pertinent key words. Arterial or venous occlusions had to be proven by objective methods. Results: Eighty-\ufb01ve patients with hemophilia A or B have been reported to have had an arterial occlusion vs. six cases of FVII de\ufb01ciency. On the contrary, 34 patients with hemophilia A or B and 32 cases with FVII de\ufb01ciency have been reported to have presented with a venous thrombosis. The ratios of arterial vs. venous thrombosis are 3.72, 1.13, and 2.50 for hemophilia A, hemophilia B, and hemophilia A + B combined, respectively, and 0.19 for FVII de\ufb01ciency. Conclusions: Hemophilia A and hemophilia B do not protect from arterial occlusions (mainly acute coronary syndromes), whereas they assure some protection from venous thrombosis. The opposite seems true for FVII de\ufb01ciency. The potential signi\ufb01cance of this discrepancy is discusse

From fine-needle aspiration cytology to fluorescent in-situ hybridization in an unusual case of pharyngeal synovial sarcoma

Synovial sarcoma arising in the pharynx is a rare entity, with very few cases described in literature, mainly as surgical-oriented case reports. We report the case of a healthy 20-year old man who presented with a painless right neck mass, clinically suspicious for a thyroid nodule. Ultrasound scan and fine-needle aspiration cytology failed to provide a definitive result, although suggesting a mesenchymal proliferation, in accordance with magnetic resonance imaging findings. Therefore, the lesion was removed with a minimally invasive surgical intervention. Definitive histologic and immunohistochemical examination of the surgical specimen revealed a biphasic synovial sarcoma, further validated by the detection of SS18 gene rearrangement on fluorescent in-situ hybridization examination. Although rarely, synovial sarcoma may arise in the pharynx. Radiological, cytological, histological and molecular findings are needed along each step of the diagnostic process

Long-term outcomes of pediatric-onset hypertrophic cardiomyopathy and age-specific risk factors for lethal arrhythmic events

IMPORTANCE Predictors of lethal arrhythmic events (LAEs) after a pediatric diagnosis of hypertrophic cardiomyopathy (HCM) are unresolved. Existing algorithms for risk stratification are limited to patients older than 16 years because of a lack of data on younger individuals. OBJECTIVE To describe the long-term outcome of pediatric-onset HCM and identify age-specific arrhythmic risk factors. DESIGN, SETTING, AND PARTICIPANTS This study assessed patients with pediatric-onset hypertrophic cardiomyopathy diagnosed from 1974 to 2016 in 2 national referral centers for cardiomyopathies in Florence, Italy. Patients with metabolic and syndromic disease were excluded. EXPOSURES Patients were assessed at 1-year intervals, or more often, if their clinical condition required. MAIN OUTCOMES AND MEASURES Lethal arrhythmic events (LAEs) and death related to heart failure. RESULTS Of 1644 patients with HCM, 100 (6.1%) were 1 to 16 years old at diagnosis (median [interquartile range], 12.2 [7.3-14.1] years). Of these, 63 (63.0%) were boys. Forty-two of the 100 patients (42.0%) were symptomatic (defined as an New York Heart Association classification higher than 1 or a Ross score greater than 2). The yield of sarcomere gene testing was 55 of 70 patients (79%). During a median of 9.2 years during which a mean of 1229 patients were treated per year, 24 of 100 patients (24.0%) experienced cardiac events (1.9%per year), including 19 LAEs and 5 heart failure-related events (3 deaths and 2 heart transplants). Lethal arrhythmic events occurred at a mean (SD) age of 23.1 (11.5) years. Two survivors of LAEs with symptoms of heart failure experienced recurrent cardiac arrest despite an implantable cardioverter defibrillator. Risk of LAE was associated with symptoms at onset (hazard ratio [HR], 8.2; 95%CI, 1.5-68.4; P = .02) and Troponin I or Troponin T gene mutations (HR, 4.1; 95%CI, 0.9-36.5; P = .06). Adult HCM risk predictors performed poorly in this population. Data analysis occurred from December 2016 to October 2017. CONCLUSIONS AND RELEVANCE Pediatric-onset HCM is rare and associated with adverse outcomes driven mainly by arrhythmic events. Risk extends well beyond adolescence, which calls for unchanged clinical surveillance into adulthood. In this study, predictors of adverse outcomes differ from those of adult populations with HCM. In secondary prevention, the implantable cardioverter defibrillator did not confer absolute protection in the presence of limiting symptoms of heart failure

Regulation of post-Golgi LH3 trafficking is essential for collagen homeostasis

Post-translational modifications are necessary for collagen precursor molecules (procollagens) to acquire final shape and function. However, the mechanism and contribution of collagen modifications that occur outside the endoplasmic reticulum and Golgi are not understood. We discovered that VIPAR, with its partner proteins, regulate sorting of lysyl hydroxylase 3 (LH3, also known as PLOD3) into newly identified post-Golgi collagen IV carriers and that VIPAR-dependent sorting is essential for modification of lysines in multiple collagen types. Identification of structural and functional collagen abnormalities in cells and tissues from patients and murine models of the autosomal recessive multisystem disorder Arthrogryposis, Renal dysfunction and Cholestasis syndrome caused by VIPAR and VPS33B deficiencies confirmed our findings. Thus, regulation of post-Golgi LH3 trafficking is essential for collagen homeostasis and for the development and function of multiple organs and tissues