Institution
Istituto Universitario Di Studi Superiori Di Pavia
Education•Pavia, Italy•
About: Istituto Universitario Di Studi Superiori Di Pavia is a education organization based out in Pavia, Italy. It is known for research contribution in the topics: Pulsar & Neutron star. The organization has 162 authors who have published 566 publications receiving 22605 citations.
Topics: Pulsar, Neutron star, Environmental science, Luminosity, Population
Papers published on a yearly basis
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16 Mar 2021
TL;DR: In this paper, the role of artificial intelligence applied to chest X-rays (CXRs) in supporting the diagnosis of COVID-19 was assessed. And they trained and cross-validated a model with an ensemble of 10 convolutional neural networks with CXRs.
Abstract: We assessed the role of artificial intelligence applied to chest X-rays (CXRs) in supporting the diagnosis of COVID-19. We trained and cross-validated a model with an ensemble of 10 convolutional neural networks with CXRs of 98 COVID-19 patients, 88 community-acquired pneumonia (CAP) patients, and 98 subjects without either COVID-19 or CAP, collected in two Italian hospitals. The system was tested on two independent cohorts, namely, 148 patients (COVID-19, CAP, or negative) collected by one of the two hospitals (independent testing I) and 820 COVID-19 patients collected by a multicenter study (independent testing II). On the training and cross-validation dataset, sensitivity, specificity, and area under the curve (AUC) were 0.91, 0.87, and 0.93 for COVID-19 versus negative subjects, 0.85, 0.82, and 0.94 for COVID-19 versus CAP. On the independent testing I, sensitivity, specificity, and AUC were 0.98, 0.88, and 0.98 for COVID-19 versus negative subjects, 0.97, 0.96, and 0.98 for COVID-19 versus CAP. On the independent testing II, the system correctly diagnosed 652 COVID-19 patients versus negative subjects (0.80 sensitivity) and correctly differentiated 674 COVID-19 versus CAP patients (0.82 sensitivity). This system appears promising for the diagnosis and differential diagnosis of COVID-19, showing its potential as a second opinion tool in conditions of the variable prevalence of different types of infectious pneumonia.
10 citations
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TL;DR: The model suggests that Hebbian rules, with adjustable post-synaptic thresholds, can provide a reliable semantic representation of objects exploiting the statistics of input features.
Abstract: According with a featural organization of semantic memory, this work is aimed at investigating, through an attractor network, the role of different kinds of features in the representation of concepts, both in normal and neurodegenerative conditions. We implemented new synaptic learning rules in order to take into account the role of partially shared features and of distinctive features with different saliency. The model includes semantic and lexical layers, coding, respectively for object features and word-forms. Connections among nodes are strongly asymmetrical. To account for the feature saliency, asymmetrical synapses were created using Hebbian rules of potentiation and depotentiation, setting different pre-synaptic and post-synaptic thresholds. A variable post-synaptic threshold, which automatically changed to reflect the feature frequency in different concepts (i.e., how many concepts share a feature), was used to account for partially shared features. The trained network solved naming tasks and word recognition tasks very well, exploiting the different role of salient versus marginal features in concept identification. In the case of damage, superordinate concepts were preserved better than the subordinate ones. Interestingly, the degradation of salient features, but not of marginal ones, prevented object identification. The model suggests that Hebbian rules, with adjustable post-synaptic thresholds, can provide a reliable semantic representation of objects exploiting the statistics of input features.
10 citations
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TL;DR: In this article, a hard X-ray burst was detected by the INTEGRAL satellite from a direction consistent with the position of AX J1818.8−1559 obtained with the Suzaku satellite in October 2011.
Abstract: In October 2007, a hard X-ray burst was detected by the INTEGRAL satellite from a direction consistent with the position of AX J1818.8−1559, an X-ray source at low Galactic latitude discovered with the Advanced Satellite for Cosmology and Astrophysics (ASCA) satellite in 1996–1999. The short duration (0.8 s) and soft spectrum (power-law photon index of 3.0 ± 0.2) of the burst in the 20–100 keV range are typical of soft gamma-ray repeaters and anomalous X-ray pulsars. We report on the results of an observation of AX J1818.8−1559 obtained with the Suzaku satellite in October 2011. The source spectrum, a power-law with photon index ∼1.5, and flux (∼2×10−12 erg cm−2 s−1, 2–10 keV) did not show significant variations from those derived from archival data of various satellites obtained from 1993 to 2011. We discuss possible interpretations of the data for AX J1818.8−1559 and, based on its association with the INTEGRAL burst, we propose it as a new member of the small class of magnetar candidates.
10 citations
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TL;DR: A socio-emotional Stroop task to assess the influence of social vs. individual (non-social) emotional content, besides negative vs. positive valence, on implicit word processing might help assessing the neural correlates of impaired social cognition and emotional regulation, and the effects of rehabilitative interventions.
10 citations
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Santa Cruz Institute for Particle Physics1, United States Naval Research Laboratory2, National Research Council3, Paris Diderot University4, Rice University5, University of Pavia6, INAF7, University of Washington8, Institut de Ciències de l'Espai9, Columbia University10, Istituto Universitario Di Studi Superiori Di Pavia11, Goddard Space Flight Center12, Max Planck Society13, University of Maryland, College Park14, Australia Telescope National Facility15, Centre national de la recherche scientifique16, George Mason University17, University of Insubria18, SLAC National Accelerator Laboratory19, National Radio Astronomy Observatory20, University of Bordeaux21, University of Manchester22
TL;DR: In this article, the discovery of eight gamma-ray pulsars in blind frequency searches using the LAT, onboard the Fermi Gamma-ray Space Telescope, was reported, and the timing models, light curves, and detailed spectral parameters of the new pulsars were presented.
Abstract: We report the discovery of eight gamma-ray pulsars in blind frequency searches using the LAT, onboard the Fermi Gamma-ray Space Telescope. Five of the eight pulsars are young (tau_c 10^36 erg/s), and located within the Galactic plane (|b|<3 deg). The remaining three are older, less energetic, and located off the plane. Five pulsars are associated with sources included in the LAT bright gamma-ray source list, but only one, PSR J1413-6205, is clearly associated with an EGRET source. PSR J1023-5746 has the smallest characteristic age (tau_c=4.6 kyr) and is the most energetic (Edot=1.1E37 erg/s) of all gamma-ray pulsars discovered so far in blind searches. PSRs J1957+5033 and J2055+25 have the largest characteristic ages (tau_c~1 Myr) and are the least energetic (Edot~5E33 erg/s) of the newly-discovered pulsars. We present the timing models, light curves, and detailed spectral parameters of the new pulsars. We used recent XMM observations to identify the counterpart of PSR J2055+25 as XMMU J205549.4+253959. In addition, publicly available archival Chandra X-ray data allowed us to identify the likely counterpart of PSR J1023-5746 as a faint, highly absorbed source, CXOU J102302.8-574606. The large X-ray absorption indicates that this could be among the most distant gamma-ray pulsars detected so far. PSR J1023-5746 is positionally coincident with the TeV source HESS J1023-575, located near the young stellar cluster Westerlund 2, while PSR J1954+2836 is coincident with a 4.3 sigma excess reported by Milagro at a median energy of 35 TeV. Deep radio follow-up observations of the eight pulsars resulted in no detections of pulsations and upper limits comparable to the faintest known radio pulsars, indicating that these can be included among the growing population of radio-quiet pulsars in our Galaxy being uncovered by the LAT, and currently numbering more than 20.
10 citations
Authors
Showing all 175 results
Name | H-index | Papers | Citations |
---|---|---|---|
Stefano F. Cappa | 94 | 520 | 38793 |
Franco Brezzi | 68 | 197 | 29296 |
Ferdinando Auricchio | 63 | 502 | 14813 |
Stefano Govoni | 61 | 421 | 12936 |
Andrea Tiengo | 55 | 354 | 12495 |
Paolo Esposito | 51 | 373 | 10414 |
Guido Montagna | 48 | 243 | 9348 |
Oreste Nicrosini | 47 | 242 | 8954 |
A. De Luca | 46 | 203 | 12942 |
M. Marelli | 45 | 99 | 10829 |
Marco Racchi | 45 | 150 | 5898 |
Giovanni F. Bignami | 41 | 236 | 16436 |
Luigi Orsenigo | 40 | 109 | 14060 |
Andre Filiatrault | 36 | 208 | 5182 |
Gian Michele Calvi | 36 | 151 | 7354 |