339 research outputs found
Distributing load flow computations across system operators boundaries using the Newton–Krylov–Schwarz algorithm implemented in PETSC
No full textThe upward trends in renewable energy penetration, cross-border flow volatility and electricity actors’ proliferation pose new challenges in the power system management. Electricity and market operators need to increase collaboration, also in terms of more frequent and detailed system analyses, so as to ensure adequate levels of quality and security of supply. This work proposes a novel distributed load flow solver enabling for better cross border flow analysis and fulfilling possible data ownership and confidentiality arrangements in place among the actors. The model exploits an Inexact Newton Method, the Newton–Krylov–Schwarz method, available in the portable, extensible toolkit for scientific computation (PETSc) libraries. A case-study illustrates a real application of the model for the TSO–TSO (transmission system operator) cross-border operation, analyzing the specific policy context and proposing a test case for a coordinated power flow simulation. The results show the feasibility of performing the distributed calculation remotely, keeping the overall simulation times only a few times slower than locally
Destination Unknown. Is there any Economics Beyond Tourism Areas?
No full textIn recent years, several papers have been focussing on various aspects of tourism destinations. The destination is a central issue within tourism studies, embodying in one single concept all the specific and problematic features of tourism, such as its systemic nature in which "space" plays a fundamental role.
In this paper we argue that tourism economics shapes itself as an independent discipline within applied economics through the analysis of destinations. Firstly, destinations are neither microeconomic agents nor macroeconomic aggregates, but territorial systems which supply at least one tourism product (a bundle of goods and services) able to satisfy the complex needs of tourism demand.
Secondly, the economic analysis of destinations can identify two specific theorems, the love of variety theorem and the coordination theorem which allow to interpret the tourism destination as a particular type of economic district, which shares some of the features of the industrial district and some others of the cultural district.
Classification-JEL: L1, L83, R3, R5Tourism economics, tourism areas, destination management, industrial districts, cultural districts
Newton-Krylov-Schwarz method for distributed power flow modelling and related applications
No full textLAUREA MAGISTRALELa rete elettrica Europea è una delle più complesse al mondo. La sempre maggiore penetrazione delle energie rinnovabili stabilisce nuove sfide nella gestione delle reti elettriche, incentivando gli operatori di rete (TSOs) ad aumentare la collaborazione al fine di garantire il trasporto efficiente e affidabile di energia elettrica. I flussi inter-zonali sono perlopiù fissati e permettono solamente una limitata flessibilità nella gestione della rete. La condivisione delle informazioni tra TSOs è ancora un problema. Lo scopo di questo lavoro è stato di costruire un tool di calcolo distribuito per la risoluzione del problema di load flow, al fine di migliorare la gestione dei flussi interzonali e allo stesso tempo garantire privacy nelle informazioni. Il modello sfrutta un metodo di Newton inesatto, noto come Newton-Krylov-Schwarz, disponibile in una libreria di calcolo, PETSc.European Electricity grid is one of the most complex grids in the world. The increasing penetration of REnewable Energy Sources (RES) sets new challenges in grid management, stressing Transmission System Operators (TSOs) to increase collaboration so as to ensure high quality and reliable transportation of electricity. Cross-border flows are nearly fixed and only allow limited flexibility for grid management. Data privacy among TSOs is still an issue. The purpose of this work has been to build a Distributed Load Flow solver for better cross-border flow management while allowing for data privacy. The model exploits an Inexact Newton Method, the Newton-Krylov-Schwarz method, available in PETSc libraries
Effectiveness and Safety of Argon Plasma Coagulation in Patients with Haemoptysis Caused by an Endobronchial Malignancy
No full textIntroduction: Patients with central neoplasms and haemoptysis show low survival rates. Symptom control without recurrence 48 h after bronchoscopic interventions may improve the prognosis of these patients. Bronchoscopic argon plasma coagulation (APC) is a useful technique for endobronchial management of haemoptysis in patients with central malignancies. Nevertheless, limited data are available in the literature on its efficacy and safety and the main predictors of success are still unclear. Methods: An observational, prospective, single-centre cohort study was carried out to assess the efficacy (i.e., immediate bleeding cessation without recurrence during the following 48 h) of bronchoscopic APC in the treatment of patients with haemoptysis caused by endobronchial malignancies and the main predictors of success. Results: A total of 76 patients with median age 75 years (interquartile range: 65-79) were enrolled. 67 (88.2%) patients had bleeding cessation without recurrence 48 h after bronchoscopic APC. A low rate of non-serious adverse events (5.3%) was recorded and a low (7.6%) recurrence rate of haemoptysis at 3.5 months after the procedure was also shown. No clinical, demographic and endoscopic variables related to a successful procedure at 48 h were found. Conclusion: This study demonstrates that bronchoscopic APC is an effective procedure in the treatment of patients with haemoptysis caused by endobronchial malignancies, regardless of the clinical characteristics of the patients, the endoscopic and histological features of the neoplasm and the severity of the symptom. Furthermore, it shows a low rate of complications and long-term efficacy in bleeding control
A diachronic study into the distributions of two Italo-Romance synthetic conditional forms
No full textTwo distinct conditional paradigms are available to speakers of Italian, derived from the Latin periphrases cantare habui/cantare habebam. The aim of this thesis is to describe and explain their patterns of attestation in the earliest northern Italian and Tuscan texts, which date from between 1200 and 1400.
Textual analysis showed that while the cantare habui periphrasis was native to both areas, the use of the cantare habebam periphrasis differed in the northern and central dialects. In the northern dialects, the cantare habebam periphrasis was attested in all genres over the whole time period, whereas in the Tuscan dialects it only appeared in literary genres. Moreover, although the northern texts attested both periphrases consistently over time in every genre, only Tuscan poetry followed this pattern. Other genres attested reflexes of the cantare habebam periphrasis for short periods in the fourteenth century. These results suggest that different influences resulted in different patterns of conditional use in the two areas.
This thesis postulates that in the northern Italo-Romance dialects the cantare habebam periphrasis was introduced through the proximity to, and influence of, Provençal. Although the use of reflexes of cantare habebam was reinforced in the north by the Sicilian school of poets, the dual nature of the sources meant that it was also retained in prose, and thence into modern dialect use. In contrast, reflexes of the cantare habebam periphrasis were introduced into central Italy through the Sicilian school alone. Although it appeared in prose texts, this was a sporadic phenomenon, resulting from imitation of the influential poetic texts. Because there was no prose source for reflexes of the cantare habebam periphrasis, it did not enter non-literary genres and quickly disappeared from literary prose genres. The cantare habebam periphrasis eventually disappeared entirely from Tuscan poetry as well, and is not attested at all in the modern central dialects
Erratum: Nodal management and upstaging of disease: Initial results from the Italian VATS Lobectomy Registry [J Thorac Dis, 9, (2017), (2061-2070)] DOI: 10.21037/jtd.2017.06.12
No full textIn the article that appeared on page 2061-2070, Vol 9, No 7 (July 2017) Issue of the Journal of Thoracic Disease (1), there are some mistakes in the presented authors information. In the list of collaborators of the Italian VATS Group are not included the following author names: Alessandro Bertani, Alessandro Gonfiotti, Mario Nosotti, Paolo Albino Ferrari, Lavinia De Monte, Emanuele Russo, Gioacchino Di Paola, Piergiorgio Solli, Andrea Droghetti, Luca Bertolaccini, Roberto Crisci. The correct list of collaborators of the Italian VATS Group should have been shown as below. Alessandro Bertani, MD (IRCCS ISMETT, Palermo); Alessandro Gonfiotti, MD (Careggi Hospital, Firenze); Mario Nosotti, MD (Policlinico Ca'Granda, Milano); Paolo Albino Ferrari, MD (IRCCS ISMETT, Palermo); Lavinia De Monte, MD (IRCCS ISMETT, Palermo); Emanuele Russo, MD (IRCCS ISMETT, Palermo); Gioacchino Di Paola, MD (IRCCS ISMETT, Palermo); Piergiorgio Solli, MD PhD (AUSL Romagna Teaching Hospital, Forlì); Andrea Droghetti, MD (ASST Mantova-Cremona, Mantova); Luca Bertolaccini, MD PhD (AUSL Romagna Teaching Hospital, Forlì); Roberto Crisci, MD PhD (Università dell'Aquila, L'Aquila); Carlo Curcio, MD (Monaldi Hospital, Napoli); Dario Amore, MD (Monaldi Hospital, Napoli); Giuseppe Marulli, MD (University of Padova); Samuele Nicotra, MD (University of Padova); Andrea De Negri, MD (San Martino Hospital, Genova); Paola Maineri, MD (San Martino Hospital, Genova); Gaetano di Rienzo (Vito Fazzi Hospital, Lecce); Camillo Lopez, MD (Vito Fazzi Hospital, Lecce); Angelo Morelli, MD (S. Maria delle Misericordia Hospital, Udine); Francesco Londero, MD (S. Maria delle Misericordia Hospital, Udine); Lorenzo Spaggiari, MD (IEO Hospital, Milano); Roberto Gasparri, MD (IEO Hospital, Milano); Guido Baietto, MD (Maggiore della Carità Hospital, Novara); Caterina Casadio, MD (Maggiore della Carità Hospital, Novara); Maurizio Infante, MD (Borgo Trento Hospital, Verona); Cristiano Benato, MD (Borgo Trento Hospital, Verona); Marco Alloisio, MD (IRCCS Humanitas, Milano); Edoardo Bottoni, MD (IRCCS Humanitas, Milano); Giuseppe Cardillo, MD (Forlanini Hospital, Roma); Francesco Carleo, MD (Forlanini Hospital, Roma); Franco Stella, MD (S. Orsola Hospital, Bologna); Giampiero Dolci, MD (S. Orsola Hospital, Bologna); Francesco Puma, MD (University of Perugia); Damiano Vinci, MD (University of Perugia); Giorgio Cavallesco, MD (University of Ferrara); Pio Maniscalco, MD (University of Ferrara); Luca Ampollini, MD (University of Parma); Paolo Carbognani, MD (University of Parma); Alberto Terzi, MD (Negrar Hospital, Verona); Andrea Viti, MD (Negrar Hospital, Verona); Giampiero Negri, MD (S. Raffaele Hospital, Milano); Alessandro Bandiera, MD (S. Raffaele Hospital, Milano); Reinhold Perkmann, MD (Bolzano Hospital, Bolzano); Francesco Zaraca, MD (Bolzano Hospital, Bolzano); Claudio Andretti, MD (S. Andrea Hospital, Roma); Camilla Poggi, MD (S. Andrea Hospital, Roma); Felice Mucilli, MD (S. Maria Annunziata Hospital, Chieti); Pierpaolo Camplese, MD (S. Maria Annunziata Hospital, Chieti); Luca Luzzi, MD (University of Siena); Marco Ghisalberti, MD (University of Siena); Andrea Imperatori, MD (University of Varese); Nicola Rotolo, MD (University of Varese); Luigi Bortolotti, MD (Humanitas Gavazzeni Hospital, Bergamo); Giovanna Rizzardi, MD (Humanitas Gavazzeni Hospital, Bergamo); Massimo Torre, MD (Niguarda Hospital, Milano); Alessandro Rinaldo, MD (Niguarda Hospital, Milano); Armando Sabbatini, MD (Ospedali Riuniti, Ancona); Majed Refai, MD (Ospedali Riuniti, Ancona); Mauro Roberto Benvenuti, MD (Spedali Civili, Brescia); Diego Benetti, MD (Spedali Civili, Brescia); Alessandro Stefani, MD (Ospedale Policlinico, Modena); Pamela Natali, MD (Ospedale Policlinico, Modena); Paolo Lausi, MD (Ospedale Molinette, Torino); Francesco Guerrera, MD (Ospedale Molinette, Torino)
Characterizing determinants of BK Polyomavirus-specific immune response
No full textBK polyomavirus (BKPyV) is one of now 13 human polyomavirus (HPyV) species detected in humans. BKPyV is only known to infect humans and seroprevalence rates of more than 90% have been reported in adult populations around the world. Following primary infection, BKPyV persists in the renourinary tract without causing any disease as evidenced by urinary shedding in 5% - 10% of healthy immunocompetent blood donors.
In immunocompromised persons, however, BKPyV can cause significant diseases whereby uncontrolled high-level replication may lead to organ invasive pathologies in kidneys, bladder, lungs, vasculature, and the central nervous system. The most consistently found diseases are BKPyV-associated hemorrhagic cystitis (BKPyVHC) in 5%-20% allogeneic hematopoietic stem cells transplant patients, and BKPyV-associated nephropathy (BKPyVAN) in 1%-15% of kidney transplant patients. BKPyVHC is highly symptomatic with pain, anemic bleeding, and increased mortality. BKPyVAN is asymptomatic except for progressive renal failure and premature return to dialysis. Both entities are characterized by high-level viral replication i.e. with urine BKPyV loads of 8-10 log10 Geq/mL, plasma BKPyV loads often above 4 log10 Geq/mL, and an allogeneic constellation between the virus-infected host cell and the available T-cell effectors. Despite these similarities, the clinical manifestations are strikingly different suggesting relevant, but experimentally undefined differences in pathogenesis. Thus, BKPyVHC typically occurs within 4 weeks after allogeneic HSCT and is confined to the bladder, and typically without kidney involvement. By contrast, BKPyVAN is diagnosed around 3-6 months after kidney transplantation and confined to the kidney allograft without causing cystitis. Although high-level BKPyV replication should be formally amenable to antiviral drug treatment, no effective and BKPyV-specific antiviral therapy is currently available. Therefore, a better understanding of the immune alteration in both diseases has been deemed essential to identify patients at risk and to develop prophylactic, preemptive and therapeutic strategies.
The currently recommended strategy for BKPyVAN is to screen kidney transplant patients for BKPyV replication and to promptly reduce immunosuppressive therapy in those with significant replication to facilitate mounting of BKPyV-specific T cell responses and thereby preventing progression to disease. This manoeuver has been linked to expanding BKPyV-specific T cell responses in the peripheral blood of kidney transplant patients. However, this approach may place patients at risk for acute rejection episodes that predispose equally well to premature kidney transplant failure. Although the clinical feasibility of reducing immunosuppression and curtailing BKPyV replication has been shown to be effective in prospective cohort studies for many, but not all of kidney transplant patients, this approach has not been possible in allogeneic HSCT patients because of concurrent or imminent graft-versus host disease. Thus, there are significant gaps in the current understanding of the BKPyV– host interaction in the normal host and in the allogeneic setting, which need to be investigated for a more effective and safer management of these significant viral complications.
In this thesis, the interaction of BKPyV and the immune response has been approached from two different angles. In the first project, potential mechanisms of BKPyV immune evasion were studied. Here, we focused on a small accessory protein called agnoprotein encoded as a leader protein in the late viral early region (LVGR). Although HPyV genomes overall show a very similar genome organization, agnoproteins are only found in the genomes of BKPyV and JCPyV that have a kidney tropisms, but not in any of the other 11 presumably non-renotropic HPyVs. We hypothesized that agnoprotein could play a role in immune evasion by downregulating HLA expression. The effects of agnoprotein were studied on HLA class I and II expression in vitro by flow cytometry following transfection of primary human renal tubular epithelial cells, which are the viral target of BKPyV-associated nephropathy. In addition, transfected human UTA-6 cells were studied as well as UTA-6 cells bearing a tetracycline-regulated agnoprotein. As control, the effects were compared with the ICP47 protein of Herpes simplex virus-1, which has been previously reported to effectively down-regulate HLA class I. Although both viral proteins share some similarities at the protein level, our results showed that BKPyV agnoprotein did not down-regulate HLA class I or class II molecules. Also, there was not inhibitory effect on the increase of HLA-class I or class-II surface expression following exposure to interferon-. By contrast, ICP47 reduced HLA class I surface expression, but not class II. We also evaluated effects of agnoprotein on virus epitope-specific T-cell killing by 51Chromium release assay, however no interference could be observed. We concluded that agnoprotein did not contribute to these types of HLA-dependent immune evasion processes. However, further investigations are needed to understand if agnoprotein could contribute to viral immune escape by other mechanisms.
In the second project, we aimed at better characterizing BKPyV-specific CD8 T cell immunity targeting epitopes encoded in the early viral gene region (EVGR). Selected coding sequences of the BKPyV EVGR were submitted to two web-based computer algorithms (SYFPEITHI, IEDB) in order to predict immunodominant 9mer epitopes presented by 14 frequent HLA-class I molecules. For an experimental confirmation, 97 different 9mer epitopes were chemically synthesized and tested in 42 healthy individuals. A total of 39 epitopes could be confirmed by interferon- ELISpot assay in at least 30% of healthy individuals. Interestingly, most of the 9mer epitopes appeared to cluster in short amino acid stretches, and some 9mer could be presented by more than one HLA class I allele as expected for immunodominant domains. HLA-specific presentation was demonstrated by 9mer- MHC-I streptamers for 21/39 (54%) epitopes. The 9mer dependent T-cell killing by 51Chromium release assay and the CD107a surface detection indicated that the 9mer epitopes could be recognized by cytotoxic T-cells. Moving to a clinically relevant situation, 13 9mer epitopes could be validated in 19 kidney transplant patients protected from, or recovering from, BKPyV viremia. The results suggest that, pending further corroboration in larger patient populations, novel 9mer epitopes can be identified, which are associated with CD8 T cell control of BKPyV replication. Thus the identified immunodominant 9mer T-cell epitopes could be further developed for clinical assays to better predict the risk and the recovery of BKPyV diseases, help guiding immunosuppression reduction, and to develop specific adoptive T-cell therapy or vaccine responses to prevent or treat BKPyV-associated disease
The Overweight Paradox: Impact of Body Mass Index on Patients Undergoing VATS Lobectomy or Segmentectomy
No full text: The aim of this study was to assess the impact of BMI on perioperative outcomes in patients undergoing VATS lobectomy or segmentectomy. Data from 5088 patients undergoing VATS lobectomy or segmentectomy, included in the VATS Group Italian Registry, were collected. BMI (kg/m2) was categorized according to the WHO classes: underweight, normal, overweight, obese. The effects of BMI on outcomes (complications, 30-days mortality, DFS and OS) were evaluated with a linear regression model, and with a logistic regression model for binary endpoints. In overweight and obese patients, operative time increased with BMI value. Operating room time increased by 5.54 minutes (S.E. = 1.57) in overweight patients, and 33.12 minutes (S.E. = 10.26) in obese patients (P < 0.001). Compared to the other BMI classes, overweight patients were at the lowest risk of pulmonary, acute cardiac, surgical, major, and overall postoperative complications. In the overweight range, a BMI increase from 25 to 29.9 did not significantly affect the length of stay, nor the risk of any complications, except for renal complications (OR: 1.55; 95% CI: 1.07-2.24; P = 0.03), and it reduced the risk of prolonged air leak (OR: 0.8; 95% CI: 0.71-0.90; P < 0.001). 30-days mortality is higher in the underweight group compared to the others. We did not find any significant difference in DFS and OS. According to our results, obesity increases operating room time for VATS major lung resection. Overweight patients are at the lowest risk of pulmonary, acute cardiac, surgical, major, and overall postoperative complications following VATS resections. The risk of most postoperative complications progressively increases as the BMI deviates from the point at the lowest risk, towards both extremes of BMI values. Thirty days mortality is higher in the underweight group, with no differences in DFS and OS
Using Data Envelopment Analysis to Evaluate Environmentally Conscious Tourism Management
No full textThis paper discusses a methodology to assess the performances of tourism management of local governments when economic and environmental aspects are considered as equally relevant. In particular, the focus is on the comparison and efficiency assessment of Italian municipalities located on the costal areas. In order to assess the efficiency status of the considered management units, Data Envelopment Analysis (DEA), a methodology for evaluating the relative efficiency of decision making units, is applied. The efficiency index measure used in DEA analysis accounts for both environmental and economic features correlated to the tourism industry. Further, potential managerial improvements for those areas resulting far from the efficiency frontier can be investigated.Data envelopment analysis, Sustainable tourism
The cult of St Nicholas in medieval Italy
No full textSt Nicholas was one of the most popular saints in medieval Italy. His cult attracted the attention
of popes, kings and emperors, and his shrine at Bari became an important international pilgrimage
destination. This thesis asks how the cult of St Nicholas came to be so widespread and popular in
Italy, and why the saint attracted the attention of diverse groups and individuals.
This thesis is structured around four chapters. The first demonstrates that through a
process of Latinisation the cult of St Nicholas became integrated within Italian literary traditions
and within a new spiritual era. Chapter Two reveals that this Latinisation also occurred within the
saint’s iconography. Chapters Three and Four are case studies of the cult in Puglia and Venice,
locations which claimed possession of the saint’s relics. These case studies show that the general
developments that the cult of St Nicholas underwent in Italy, identified in Chapters One and Two,
did not apply universally. Instead, the presence of the saint’s relics resulted in a different profile
of the saint in Bari and Venice. Through the process of Latinisation, the cult of St Nicholas
became updated and remained relevant for its new Italian audience; Chapters Three and Four
show alternative ways that the cult of St Nicholas gained widespread popularity.
This thesis presents for the first time an iconographical study of St Nicholas in Italian art,
which develops existing research of the saint’s Byzantine iconography. Chapter Four presents a
profile of the cult of St Nicholas in Venice in the Middle Ages, which is a significant oversight in
the literature. The thesis uses a variety of visual and textual sources, in particular fresco and
altarpiece representations, archival documents from Venice and Rome (including the Apostolic
Visitations), and under-exploited contemporary and antiquarian Venetian sources
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