University of Trento

About: University of Trento is a education organization based out in Trento, Italy. It is known for research contribution in the topics: Population & Context (language use). The organization has 10527 authors who have published 30978 publications receiving 896614 citations. The organization is also known as: Universitá degli Studi di Trento & Universita degli Studi di Trento.

Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun

Abstract: Critical measurements for understanding accretion and the dust/gas ratio in the solar nebula, where planets were forming 4.5 billion years ago, are being obtained by the GIADA (Grain Impact Analyser and Dust Accumulator) experiment on the European Space Agency’s Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko. Between 3.6 and 3.4 astronomical units inbound, GIADA and OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) detected 35 outflowing grains of mass 10−10 to 10−7 kilograms, and 48 grains of mass 10−5 to 10−2 kilograms, respectively. Combined with gas data from the MIRO (Microwave Instrument for the Rosetta Orbiter) and ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instruments, we find a dust/gas mass ratio of 4 ± 2 averaged over the sunlit nucleus surface. A cloud of larger grains also encircles the nucleus in bound orbits from the previous perihelion. The largest orbiting clumps are meter-sized, confirming the dust/gas ratio of 3 inferred at perihelion from models of dust comae and trails.

Is There a Role for Lung Ultrasound During the COVID-19 Pandemic?

Abstract: Lung ultrasound (LUS) has evolved considerably over the last years with respect to its theoretical and operative aspects. Consequently, its clinical application has come to be sufficiently known and widespread. One of the characteristic aspects of LUS is the ability to define the alterations affecting the ratio between tissue and air in the superficial lung. Normally, the lung surface mainly consists of air. Incident ultrasound (US) waves are thus generally completely back-reflected by the visceral pleural plane, especially when healthy. In this context, the scattering of US waves produces artifactual images characterized by horizontal reverberations of the pleural line (A-lines) and mirror effects. When the ratio between air, tissue, fluid, or other biological components is reduced, the lung no longer presents itself as an almost complete specular reflector. Hence, various types of localized vertical artifacts appear on the US images in relation to the alterations of the subpleural tissue. These artifacts have generally been called B-lines, but recently it has become clear that B-lines are very heterogeneous in their appearance. Moreover, their heterogeneity may be exploited as a means to characterize the alterations of the lung surface. Another well-known phenomenon linked to the increase in subpleural lung density (in the absence of consolidated tissue) is the coalescence of many vertical artifacts in more extended echogenic patterns, in which the individual artifacts are still recognizable or fused in a single homogeneous subpleural echogenic area (white lung). When the subpleural density goes toward the value of 1 g/mL (about that of the solid tissue), then consolidations appear. Therefore, the clinician, through the visual inspection of LUS images, can detect, at the subpleural level, nonconsolidative increases in the ratio between full (tissue) and empty (air) and assess them in a range between normal and consolidative. Topographic images of the lesions can also be acquired. Finally, the extent of these lesions on the lung surface, as well as their evolution or regression over time, can also be evaluated. The study of these patterns shows very high sensitivity in cases of interstitial and alveolar-interstitial lung diseases, which have a peripheral distribution. Numerous studies on acute respiratory distress syndrome (ARDS) confirm this. Other studies related to the 2009 pandemic influenza A (H1N1) epidemic confirm these hypotheses even in a virally infectious setting. The recent pneumonia outbreak spreading from Wuhan, China, in December 2019 is caused by the 2019 novel coronavirus infection, defined as new coronavirus disease (COVID-19). This epidemic currently involves many areas of the world, with particular incidence in Italy, representing a serious challenge to public health and the efficiency of the health care structures. The histopathologic appearance of initial COVID19 pneumonia is characterized by alveolar damage, which includes alveolar edema, while the inflammatory component is patchy and mild. Reparative processes with pneumocyte hyperplasia and interstitial thickening can occur. The advanced phases show gravitational consolidations similar to those of ARDS. There are hemorrhagic necrosis, alveolar congestion, edema, flaking, and fibrosis. An analysis of the available computed tomographic (CT) data from patients with COVID-19 pneumonia shows largely bilateral lesions that are patchy and also confluent, appearing as ground glass or with a mixed consolidative and ground glass pattern. Ten percent of lesions with a crazy-paving appearance are reported. The lesions often have a wedge-like appearance with a pleural base. Major consolidations may show air bronchograms. Pleural effusion is absent. Patchy or confluent lesions tend to be distributed along the pleura. The lobe most frequently affected is the lower right lobe, followed by the upper and lower left lobes. The posterior lung is involved in 67% of cases. Given that LUS can identify changes in the physical state of superficial lung tissue, which correlate with histopathologic findings and can be identified on CT but remain hidden in a large percentage of chest radiographs, the role of LUS can be relevant in the context of the COVID-19 epidemic. It should also not be underestimated that, in experimental models of ARDS, LUS has proved capable of detecting lung lesions before the development of hypoxemia. The current clinical evidence (although not yet represented in the literature), the theoretical bases of LUS in the aerated lung, and LUS findings of similar aspects in other diseases (ARDS and flu virus

Deep Complex Networks

Abstract: At present, the vast majority of building blocks, techniques, and architectures for deep learning are based on real-valued operations and representations. However, recent work on recurrent neural networks and older fundamental theoretical analysis suggests that complex numbers could have a richer representational capacity and could also facilitate noise-robust memory retrieval mechanisms. Despite their attractive properties and potential for opening up entirely new neural architectures, complex-valued deep neural networks have been marginalized due to the absence of the building blocks required to design such models. In this work, we provide the key atomic components for complex-valued deep neural networks and apply them to convolutional feed-forward networks and convolutional LSTMs. More precisely, we rely on complex convolutions and present algorithms for complex batch-normalization, complex weight initialization strategies for complex-valued neural nets and we use them in experiments with end-to-end training schemes. We demonstrate that such complex-valued models are competitive with their real-valued counterparts. We test deep complex models on several computer vision tasks, on music transcription using the MusicNet dataset and on Speech Spectrum Prediction using the TIMIT dataset. We achieve state-of-the-art performance on these audio-related tasks.

Social enterprise: An international overview of its conceptual evolution and legal implementation

Abstract: – The purpose of this paper is to analyze the evolution of the social enterprise concept at an international level. It provides a comprehensive overview of the existing literature in this subject area and focuses on the legal implementation of social enterprises., – The paper is an analytic review, building on previous work. Conclusions are on how the social enterprise concept has been legally implemented in a number of representative European countries., – The lack of a common understanding of social enterprise should not be regarded as a limitation as such debate encourages a rethinking of the theoretical definition of enterprise and its legal structure. The legal recognition of social enterprise contributes to conceptual clarification in the countries concerned., – This is a conceptual discussion paper, which stimulates further research on the most interesting mechanisms and consistent models of social enterprise that are developing at an international level., – The paper synthesises existing conceptual studies on social enterprise. It contributes to enrich the current debate on social enterprise and aids in focusing future research.