Motion among random obstacles on a hyperbolic space

We consider the motion of a particle along the geodesic lines of the Poincar\`e half-plane. The particle is specularly reflected when it hits randomly-distributed obstacles that are assumed to be motionless. This is the hyperbolic version of the well-known Lorentz Process studied by Gallavotti in the Euclidean context. We analyse the limit in which the density of the obstacles increases to infinity and the size of each obstacle vanishes: under a suitable scaling, we prove that our process converges to a Markovian process, namely a random flight on the hyperbolic manifold.Comment: 19 pages, 4 figure

Some families of random fields related to multiparameter L\'evy processes

Let $\mathbb{R}^N_+= [0,\infty)^N$. We here consider a class of random fields $(X_t)_{t\in \mathbb{R}^N_+}$ which are known as Multiparameter L\'evy processes. Related multiparameter semigroups of operators and their generators are represented as pseudo-differential operators. We also consider the composition of $(X_t)_{t\in \mathbb{R}^N_+}$ by means of the so-called subordinator fields and we provide a Phillips formula. We finally study the composition of $(X_t)_{t\in \mathbb{R}^N_+}$ by means of the so-called inverse random fields, which gives rise to interesting long range dependence properties. As a byproduct of our analysis, we study a model of anomalous diffusion in an anisotropic medium which extends the one treated in [8]

Melanoma: esperienza della Clinica Dermatologica di Pisa

Scopo del nostro studio è di calcolare i trend d’incidenza per istotipo di melanoma per verificare se la crescita dei tassi d’incidenza osservata in questi ultimi anni sia legata prevalentemente se non esclusivamente alle forme a diffusione superficiale e non alle altre, e di valutare le loro correlazioni con il sito anatomico

Tra economia e politica: l'internazionalizzazione di Finmeccanica, Eni ed Enel

In an economic system dominated by small and medium enterprises, striking among the large companies are Finmeccanica, Eni and Enel, partially controlled by the Ministry of the Economy and Finance. What are the links between politics and the choices of these companies? Have the changes in the political colour of the governments modified the entrepreneurial policies? Starting from the partial privatisation of these large companies, the book seeks to trace the thread linking politics and economics

Corporate Governance Reforms, Interlocking Directorship and Company Performance in Italy

We analyze the effects of corporate governance reforms on interlocking directorship (ID), and we assess the relationship between interlocking directorships and company performance for the main Italian firms listed on the Italian stock exchange over 1998-2007. We use a unique dataset that includes corporate governance variables related to the board size, interlocking directorships and variables related to companies’ performances. The network analysis showed only some effectiveness of these reforms in slightly dispersing the web of companies. Using a diff-in-diff approach, we then find in the period considered a slight reduction in the returns of those companies where interlocking directorships were used the most, which confirms our assumption on the perverse effect of ID on company performance in a context prone to shareholder expropriation such as the Italian on

Corporate Governance Reforms, Interlocking Directorship and Company Performance in Italy

We analyze the effects of corporate governance reforms on interlocking directorship (ID), and we assess the relationship between interlocking directorships and company performance for the main Italian firms listed on the Italian stock exchange over 1998-2007. We use a unique dataset that includes corporate governance variables related to the board size, interlocking directorships and variables related to companies’ performances. The network analysis showed only some effectiveness of these reforms in slightly dispersing the web of companies. Using a diff-in-diff approach, we then find in the period considered a slight reduction in the returns of those companies where interlocking directorships were used the most, which confirms our assumption on the perverse effect of ID on company performance in a context prone to shareholder expropriation such as the Italian on

Modeling the contribution of male testosterone levels to the duration of positive COVID testing among hospitalized male COVID-19 patients

Background: A growing body of evidence is emerging suggesting testosterone can affect all cells involved in the immune response to both bacterial and viral infections, and the testosterone effect on the immune response could explain the greater susceptibility of men to infections including COVID-19. We aimed to explore the predictive role of male serum total testosterone (TT) levels on the time till viral negativity testing among hospitalized COVID-19 patients. Methods: The univariate effect of risk factors for the duration of COVID-19 viral positivity was evaluated using the log-rank test and Kaplan-Meier estimates. A multivariable Cox regression model was developed to test the role of TT levels and the subsequent odds for shorter viral positivity intervals. Results: Increasing serum TT levels and the need for an oxygen administration strategy were independently predictive for respectively reduced and increased days to negativization (Hazard Ratio [HR]: 1.39, 95% CI: 0.95-2.03 and HR: 0.19, 95% CI: 0.03-1.18). Conclusion: Baseline higher TT levels for male COVID-19 patients at hospital admission are associated with shorter durations of positive COVID-19 testing and thus viral clearance. Our preliminary findings might play a relevant to help pandemic control strategies if these will be verified in future larger multicentric and possibly randomized trials

Safety and feasibility of outpatient surgery in benign prostatic hyperplasia: a systematic review and meta-analysis

Purpose: Most of endourological procedures along the urinary tract have been widely practiced as outpatient operations, including surgery for BPH. This systematic review and meta-analysis was conducted to assess safety and feasibility of outpatient surgery for patients suffering from symptomatic BPH candidate for endoscopic disobstruction. Materials and methods: PubMed, Web of Science, Cochrane, and Embase were searched up until March 30, 2020. MINORS tool was utilized to assess the quality of included studies and a pooled measure of failure or event rate (FR, ER) estimate was calculated. Further sensitivity analysis, subgroup analysis, and meta-regression were conducted to investigate contribution of moderators to heterogeneity. Results: Twenty studies with a total of 1626 patients treated according to outpatient criteria for endoscopic BPH surgery were included. In total, 18 studies reporting data on immediate hospital readmission and/or inability to discharge after endoscopic procedure presented FR estimates ranging from 1.7% to 51.1%. Pooled FR estimate was 7.8% (95% confidence interval [CI]: 5.2%-10.3%); Heterogeneity: Q=76.85; d.f.=17, p<.001; I2= 75.12%. Subgroup analysis according to surgical technique revealed difference among the three approaches with pooled FR of 3% (95%CI: 1%-4.9%), 7.1% (95%CI: 3.9-10.4) and 11.8% (95%CI: 7-16.7%) for TURP, Green-light and HoLEP respectively (p<.001). At meta-regression analysis, none of the retrieved covariates were able to significantly influence the cumulative outcomes reported. ER for postoperative complications and early outpatient visit showed a pooled estimate of 18.6% (95%CI: 13.2%-23.9%) and 7.7% (95%CI: 4.3%-11%) respectively. Conclusions: Our analysis revealed how transurethral procedures for BPH on an outpatient setting are overall reliable and safe. Of note, there were significant outcome differences between groups with regard of type of surgical procedure, perioperative prostate volume and discharge protocol suggesting the need for further prospective analysis to better elucidate the best strategy in such outpatient conduct

A tryptophan metabolite prevents depletion of circulating endothelial progenitor cells in systemic low-grade inflammation

BackgroundChronic systemic inflammation reduces the bioavailability of circulating endothelial progenitor cells (EPCs). Indoleamine 2,3-dioxygenase 1 (IDO1), a key enzyme of immune tolerance catalyzing the initial step of tryptophan degradation along the so-called l-kynurenine (l-kyn) pathway, that is induced by inflammatory stimuli and exerts anti-inflammatory effects. A specific relationship between IDO1 activity and circulating EPC numbers has not yet been investigated.MethodsIn this study, circulating EPCs were examined in mice treated with low doses of lipopolysaccharide (LPS) to mimic low-grade inflammation. Moreover, the association between IDO1 activity and circulating EPCs was studied in a cohort of 277 patients with variable systemic low-grade inflammation.ResultsRepeated low doses of LPS caused a decrease in circulating EPCs and l-kyn supplementation, mimicking IDO1 activation, significantly increased EPC numbers under homeostatic conditions preventing EPC decline in low-grade endotoxemia. Accordingly, in patients with variable systemic low-grade inflammation, there was a significant interaction between IDO1 activity and high-sensitivity C-reactive protein (hs-CRP) in predicting circulating EPCs, with high hs-CRP associated with significantly lower EPCs at low IDO1 activity but not at high IDO1 activity.InterpretationOverall, these findings demonstrate that systemic low-grade inflammation reduces circulating EPCs. However, high IDO1 activity and l-kyn supplementation limit circulating EPC loss in low-grade inflammation

Civiltà della Campania. Anno I, n. 1 (dicembre 1974)

A.I, n. 1 (dicembre 1974): M. Parrilli, Editoriale, P. 3 ; R. Virtuoso, Civiltà della Campania, P. 3 ; G. Galasso, Fisionomìa storica della regione, P. 6 ; Natale in Campania, P. 11, R. Causa, Cinque secoli di Presepe di, P. 12 ; M. Stefanile, I presepi d’una volta di, P. 20 ; D. Rea, L’universo mangereccio del Presepe di, P. 28 ; M. Prisco, Il presepe in provincia di, P. 34 ; B. Gatta, Una storia che non fu, P. 42 ; A. Mozzillo, Stendhal a Napoli, P. 47 ; E. Perrin, Viaggio a Cava d’un abate francese, P. 52 ; A.P. Carbone, Ravello: Villa Rufolo un paradiso per tutti, 54 ; D. Fernandez, Lettera d’amore a Napoli, P. 60 ; A. Gatto, Un mazzetto di poesie con la mia mano, 54 ; M. Parrilli, Vocazione turistica e culturale del Salernitano, P. 60 ; E. Comito, Poesia di Casertantica, P. 64 ; A. Fratta, Majorca e le Sirene, P. 67 ; V. Ricciuti, De Sica addio, P. 72 ; M. Perrotta, Il motoscafo spazzino del mare di Capri, P. 76 ; F. Canessa, Ritorna l’« opera buffa », P. 78 ; P. Gargano, Archeologia in villa, P. 83 ; E. Corsi, Per un nuovo equilibrio alberghiero, P. 86 ; F. Garbaccio, Un termalismo per tutte le stagioni, P. 88; G. Blasi, Amalfi by night, P. 90 ; A. Scelzo, La maratona Paestum-Salerno, P. 91 ; Notiziario, P. 92 ; F. De Ciuceis, Segnalazioni bibliografiche, P. 95