52 research outputs found

    Neural hypernetwork approach for pulmonary embolism diagnosis

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    Background Hypernetworks are based on topological simplicial complexes and generalize the concept of two-body relation to many-body relation. Furthermore, Hypernetworks provide a significant generalization of network theory, enabling the integration of relational structure, logic and analytic dynamics. A pulmonary embolism is a blockage of the main artery of the lung or one of its branches, frequently fatal. Results Our study uses data on 28 diagnostic features of 1427 people considered to be at risk of pulmonary embolism enrolled in the Department of Internal and Subintensive Medicine of an Italian National Hospital “Ospedali Riuniti di Ancona”. Patients arrived in the department after a first screening executed by the emergency room. The resulting neural hypernetwork correctly recognized 94 % of those developing pulmonary embolism. This is better than previous results obtained with other methods (statistical selection of features, partial least squares regression, topological data analysis in a metric space). Conclusion In this work we successfully derived a new integrative approach for the analysis of partial and incomplete datasets that is based on Q-analysis with machine learning. The new approach, called Neural Hypernetwork, has been applied to a case study of pulmonary embolism diagnosis. The novelty of this method is that it does not use clinical parameters extracted by imaging analysis

    The mammals of Angola

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    Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the countryinfo:eu-repo/semantics/publishedVersio

    Prolonging the Shelf Life of Homemade Gelatin Ultrasound Phantoms

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    A significant limitation of homemade phantoms is shelf life. Our goal was to compare the impact on shelf life of easily obtained additives. Fifteen additives were mixed into a gelatin-psyllium hydrophilic mucilloid fiber phantom; three of these additives were used as a layer on top of the phantom. The mixtures were stored in the refrigerator and at room temperature. The samples were evaluated daily for microbial growth and phantom degradation. A 4% of chlorhexidine gluconate layer on top of the phantom quickly made the phantom unusable. The addition of benzoic acid and bleach to the mixture negatively affected phantom appearance with ultrasound imaging. The addition of household bleach or 4% chlorhexidine gluconate to the mixture or a 10% povidone-iodine layer on top of the phantom was the best way to preserve samples stored at room temperature. The refrigerated sample outlasted the paired room temperature sample in every case, with most room temperature samples becoming unusable by day 10 and most refrigerated samples lasting past 50 days
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