"Realizzazione di un ricevitore VHF aeronautico su piattaforma software-defined radio di tipo SCA (Software Communications Architecture)"

Questo lavoro di tesi presenta la realizzazione di un ricevitore VHF, nella banda che va da 118 a 137 MHz, implementato su una piattaforma di tipo software defined-radio secondo le regole dell'architettura SCA (Software Communications Architecture). Dopo aver descritto accuratamente il sistema SDR (Software Defined Radio), l'architettura SCA e OSSIE, il software grazie al quale è stato possibile sviluppare e poi validare il ricevitore, viene decritto lo standard VHF aeronautico per le comunicazioni vocali definito dall'ICAO (International Civil Aviation Organization). Il lavoro prosegue descrivendo le funzionalità di ogni blocco del ricevitore VHF aeronautico e la sua implementazione software mediante la waveform ric_vhf_aeronautico costruita grazie all'ambienete di sviluppo Eclipse di OSSIE. I risultati ottenuti con questo progetto sono una ottima flessibilità, una buona riconfigurabiltà, compatibilità con altri sistemi radio SDR e grandi vantaggi in termini economici vista la possibilità di apportare delle modifiche al sistema, in real time, senza dover cambiare l'hardware sottostante. Dal punto di vista prestazionale, il ricevitore VHF software possiede una qualità del segnale audio di poco inferiore ad un ricevitore hardware commerciale presentando infatti un livello di rumore leggermente più elevato. Il funzionamento del ricevitore VHF presenta un leggero carico computazionale e quindi la possibiltà di essere caricato su un PC standard. This thesis presents the development of a VHF receiver, the bandwidth ranging from 118 to 137 MHz, implemented on a software-defined radio platform according to the rules of architecture SCA (Software Communications Architecture). After describing accurately the system SDR (Software Defined Radio), SCA and OSSIE, the software with which it was possible to develop and then validate the receiver, it decrypts the standard aeronautical VHF voice communications defined by the ICAO (International Civil Aviation Organization). The work goes on to describe the functionality of each block of the aeronautical VHF receiver and its software implementation using the waveform ric_vhf_aeronautico built with the Eclipse developed by OSSIE. The results from this project are a good flexibility, good riconfigurability, compatibility with other radio SDR systems and great advantages in economic terms because of the possibility to make changes to your system in real time, without changing the underlying hardware. From the performance standpoint, the VHF receiver software has a quality of the audio signal just under to a receiver commercial hardware by presenting in fact a slightly higher noise level. The operation of the VHF receiver has a light computational load and therefore the ability to be loaded on a standard PC

A Novel Differential Time-of-Arrival Estimation Technique for Impact Localization on Carbon Fiber Laminate Sheets

Composite material structures are commonly used in many industrial sectors (aerospace, automotive, transportation), and can operate in harsh environments where impacts with other parts or debris may cause critical safety and functionality issues. This work presents a method for improving the accuracy of impact position determination using acoustic source triangulation schemes based on the data collected by piezoelectric sensors attached to the structure. A novel approach is used to estimate the Differential Time-of-Arrival (DToA) between the impact response signals collected by a triplet of sensors, overcoming the limitations of classical methods that rely on amplitude thresholds calibrated for a specific sensor type. An experimental evaluation of the proposed technique was performed with specially made circular piezopolymer (PVDF) sensors designed for Structural Health Monitoring (SHM) applications, and compared with commercial piezoelectric SHM sensors of similar dimensions. Test impacts at low energies from 35 mJ to 600 mJ were generated in a laboratory by free-falling metal spheres on a 500 mm × 500 mm × 1.25 mm quasi-isotropic Carbon Fiber Reinforced Polymer (CFRP) laminate plate. From the analysis of many impact signals, the resulting localization error was improved for all types of sensors and, in particular, for the circular PVDF sensor an average error of 20.3 mm and a standard deviation of 8.9 mm was obtained

The spread of multi drug resistant infections is leading to an increase in the empirical antibiotic treatment failure in cirrhosis: a prospective survey

Background The spread of multi-resistant infections represents a continuously growing problem in cirrhosis,particularly in patients in contact with the healthcare environment. Aim Our prospective study aimed to analyze epidemiology, prevalence and risk factors of multiresistant infections, as well as the rate of failure of empirical antibiotic therapy in cirrhotic patients. Methods All consecutive cirrhotic patients hospitalized between 2008 and 2013 with a microbiologically-documented infection (MDI) were enrolled. Infections were classified as Community- Acquired (CA), Hospital-Acquired (HA) and Healthcare-Associated (HCA). Bacteria were classified as Multidrug-Resistant (MDR) if resistant to at least three antimicrobial classes, Extensively-Drug-Resistant (XDR) if only sensitive to one/two classes and Pandrug-Resistant (PDR) if resistant to all classes. Results One-hundred-twenty-four infections (15% CA, 52% HA, 33% HCA) were observed in 111 patients. Urinary tract infections, pneumonia and spontaneous bacterial peritonitis were the more frequent. Forty-seven percent of infections were caused by Gram-negative bacteria. Fifty-one percent of the isolates were multi-resistant to antibiotic therapy (76% MDR, 21% XDR, 3% PDR): the use of antibiotic prophylaxis (OR = 8.4; 95%CI = 1.03-76; P = 0,05) and current/recent contact with the healthcare-system (OR = 3.7; 95%CI = 1.05-13; P = 0.04) were selected as independent predictors. The failure of the empirical antibiotic therapy was progressively more frequent according to the degree of resistance. The therapy was inappropriate in the majority of HA and HCA infections. Conclusions Multi-resistant infections are increasing in hospitalized cirrhotic patients. A better knowledge of the epidemiological characteristics is important to improve the efficacy of empirical antibiotic therapy. The use of preventive measures aimed at reducing the spread of multi-resistant bacteria is also essential

Efficacy of MRI data harmonization in the age of machine learning. A multicenter study across 36 datasets

Pooling publicly-available MRI data from multiple sites allows to assemble extensive groups of subjects, increase statistical power, and promote data reuse with machine learning techniques. The harmonization of multicenter data is necessary to reduce the confounding effect associated with non-biological sources of variability in the data. However, when applied to the entire dataset before machine learning, the harmonization leads to data leakage, because information outside the training set may affect model building, and potentially falsely overestimate performance. We propose a 1) measurement of the efficacy of data harmonization; 2) harmonizer transformer, i.e., an implementation of the ComBat harmonization allowing its encapsulation among the preprocessing steps of a machine learning pipeline, avoiding data leakage. We tested these tools using brain T1-weighted MRI data from 1740 healthy subjects acquired at 36 sites. After harmonization, the site effect was removed or reduced, and we measured the data leakage effect in predicting individual age from MRI data, highlighting that introducing the harmonizer transformer into a machine learning pipeline allows for avoiding data leakage

Progression of brain atrophy in spinocerebellar ataxia type 2: A longitudinal tensor-based morphometry study

Spinocerebellar ataxia type 2 (SCA2) is the second most frequent autosomal dominant inherited ataxia worldwide. We investigated the capability of magnetic resonance imaging (MRI) to track in vivo progression of brain atrophy in SCA2 by examining twice 10 SCA2 patients (mean interval 3.6 years) and 16 age- and gender-matched healthy controls (mean interval 3.3 years) on the same 1.5 T MRI scanner. We used T1-weighted images and tensor-based morphometry (TBM) to investigate volume changes and the Inherited Ataxia Clinical Rating Scale to assess the clinical deficit. With respect to controls, SCA2 patients showed significant higher atrophy rates in the midbrain, including substantia nigra, basis pontis, middle cerebellar peduncles and posterior medulla corresponding to the gracilis and cuneatus tracts and nuclei, cerebellar white matter (WM) and cortical gray matter (GM) in the inferior portions of the cerebellar hemisphers. No differences in WM or GM volume loss were observed in the supratentorial compartment. TBM findings did not correlate with modifications of the neurological deficit. In conclusion, MRI volumetry using TBM is capable of demonstrating the progression of pontocerebellar atrophy in SCA2, supporting a possible role of MRI as biomarker in future trials

Validation and Ecological Niche Investigation of a New Fungal Intraspecific Competitor as a Biocontrol Agent for the Sustainable Containment of Aflatoxins on Maize Fields

Crop yield and plant products quality are directly or indirectly affected by climate alterations. Adverse climatic conditions often promote the occurrence of different abiotic stresses, which can reduce or enhance the susceptibility to pests or pathogens. Aflatoxin producing fungi, in particular, whose diffusion and deleterious consequences on cereals commodities have been demonstrated to highly depend on the temperature and humidity conditions that threaten increasingly larger areas. Biological methods using intraspecific competitors to prevent fungal development and/or toxin production at the pre-harvest level are particularly promising, even if their efficacy could be affected by the ecological interaction within the resident microbial population. A previously characterized Aspergillus flavus atoxigenic strain was applied in two maize fields to validate its effectiveness as a biocontrol agent against aflatoxin contamination. At one month post-application, at the harvest stage, its persistence within the A. flavus population colonizing the maize kernels in the treated area was assessed, and its efficacy was compared in vitro with a representation of the isolated atoxigenic population. Results proved that our fungal competitor contained the aflatoxin level on maize grains as successfully as a traditional chemical strategy, even if representing less than 30% of the atoxigenic strains re-isolated, and achieved the best performance (in terms of bio-competitive potential) concerning endogenous atoxigenic isolates

Plasma cholesterol and lipoprotein levels in relation to tumor aggressiveness and survival in HCC patients

open13Hepatocellular carcinoma is associated with several chronic liver diseases, especially chronic hepatitis B virus, hepatitis C virus, and alcoholism. It is increasingly appreciated that obesity/metabolic syndrome is also associated with chronic liver disease and subsequent hepatocellular carcinoma.openCarr, Brian I; Giannelli, Gianluigi; Guerra, Vito; Giannini, Edoardo G; Farinati, Fabio; Rapaccini, Gian Ludovico; Marco, Maria Di; Zoli, Marco; Caturelli, Eugenio; Masotto, Alberto; Virdone, Roberto; Sacco, Rodolfo; Trevisani, FrancoCarr, Brian I; Giannelli, Gianluigi; Guerra, Vito; Giannini, Edoardo G; Farinati, Fabio; Rapaccini, Gian Ludovico; Marco, Maria Di; Zoli, Marco; Caturelli, Eugenio; Masotto, Alberto; Virdone, Roberto; Sacco, Rodolfo; Trevisani, Franc

Religious freedom before, during and after Covid-19 between Europe and the Member States

Interventi tenuti il 26 novembre 2021 in occasione del Seminario di studio sul tema “Religious freedom before, during and after covid-19 between Europe and the Member States” organizzato dall’Eulerit Academic Forum dell’Università degli Studi di Trieste col supporto del Modulo Jean Monnet su “The European impact on the regulation Law&Religion in Italy and Beyond

Diode laser stimulation prevents Fibroblast- Myofibroblast transition reducing TRPC1 expression: new perspectives for tissue fibrosis treatment

Fibrosis consists in a excessive and persistent formation of fibrous connective tissue that occurs frequently in different organs or tissues after an injury. The cells principally involved in the onset and progression of fibrosis, are the activated form of the fibroblasts, namely myofibroblasts. Although required for the wound healing and the reparative response to organ/tissue damage, myofibroblast persistence contributes to the increased synthesis and deposition of extracellular matrix proteins, which replace the necrotic or damaged tissue with a scar. In such perspective, identification of treatments capable of preventing myofibroblast generation and defining their molecular targets appears a key step for the design of therapeutic strategies aimed at counteracting fibrosis. On these bases, in the present study, by a morphological, biochemical and electrophysiological approach, we evaluated the effects of a diode laser treatment (635 nm) on the differentiation of NIH3T3 fibroblasts into myofibroblasts. We found that the laser stimulation was able to inhibit TGF-β1-induced fibroblast-myofibroblast transition and modify the myofibroblast resting membrane potential and inwardly rectifying K+ currents. We also found that the treatment up-regulated metalloprotease (MMP)-2 and -9 expression and downregulated the tissue inhibitors of metalloproteinases (TIMP)1 and -2 in TGF-β1-treated cells. Interestingly, the effects of the laser on fibroblasts involved the Transient Receptor Potential Channel 1 (TRPC-1) functionality. In conclusion, the present study besides offering novel experimental evidence on the mechanisms of action of the diode laser, may provide a promising therapeutic perspective for the treatment of tissue fibrosis extending the potential clinical application of the low level laser therapy