43 research outputs found

    Privacy-Preserving Design of Data Processing Systems in the Public Transport Context

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    The public transport network of a region inhabited by more than 4 million people is run by a complex interplay of public and private actors. Large amounts of data are generated by travellers, buying and using various forms of tickets and passes. Analysing the data is of paramount importance for the governance and sustainability of the system. This manuscript reports the early results of the privacy analysis which is being undertaken as part of the analysis of the clearing process in the Emilia-Romagna region, in Italy, which will compute the compensations for tickets bought from one operator and used with another. In the manuscript it is shown by means of examples that the clearing data may be used to violate various privacy aspects regarding users, as well as (technically equivalent) trade secrets regarding operators. The ensuing discussion has a twofold goal. First, it shows that after researching possible existing solutions, both by reviewing the literature on general privacy-preserving techniques, and by analysing similar scenarios that are being discussed in various cities across the world, the former are found exhibiting structural effectiveness deficiencies, while the latter are found of limited applicability, typically involving less demanding requirements. Second, it traces a research path towards a more effective approach to privacy-preserving data management in the specific context of public transport, both by refinement of current sanitization techniques and by application of the privacy by design approach. Available at: https://aisel.aisnet.org/pajais/vol7/iss4/4

    Universal Behavior of Lyapunov Exponents in Unstable Systems

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    We calculate the Lyapunov exponents in a classical molecular dynamics framework. The system is composed of few hundreds particles interacting either through Yukawa (Nuclear) or Slater-Kirkwood (Atomic) forces. The forces are chosen to give an Equation of State that resembles the nuclear and the atomic 4He^4He Equation Of State respectively near the critical point for liquid-gas phase transition. We find the largest fluctuations for an initial "critical temperature". The largest Lyapunov exponents λ\lambda are always positive and can be very well fitted near this "critical temperature" with a functional form λTTcω\lambda\propto |T-T_c|^{-\omega}, where the exponent ω=0.15\omega=0.15 is independent of the system and mass number. At smaller temperatures we find that λT 0.4498\lambda\propto T~ ^{0.4498}, a universal behavior characteristic of an order to chaos transition.Comment: 11 pages, RevTeX, 3 figures not included available upon reques

    Is There a Crucial Link Between Vitamin D Status and Inflammatory Response in Patients With COVID-19?

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    Background: Hypovitaminosis D has been suggested to play a possible role in coronavirus disease 2019 (COVID-19) infection. Methods: The aim of this study is to analyze the relationship between vitamin D status and a biochemical panel of inflammatory markers in a cohort of patients with COVID-19. A secondary endpoint was to evaluate the correlation between 25OHD levels and the severity of the disease. Ninety-three consecutive patients with COVID-19-related pneumonia were evaluated from March to May 2020 in two hospital units in Pisa, in whom biochemical inflammatory markers, 25OHD levels, P/F ratio at nadir during hospitalization, and complete clinical data were available. Results: Sixty-five percent of patients presented hypovitaminosis D (25OHD ≤ 20 ng/ml) and showed significantly higher IL-6 [20.8 (10.9–45.6) vs. 12.9 (8.7–21.1) pg/ml, p = 0.02], CRP [10.7 (4.2–19.2) vs. 5.9 (1.6–8.1) mg/dl, p = 0.003], TNF-a [8.9 (6.0–14.8) vs. 4.4 (1.5–10.6) pg/ml, p = 0.01], D-dimer [0.53 (0.25–0.72) vs. 0.22 (0.17–0.35) mg/l, p = 0.002], and IL-10 [3.7 (1.8–6.9) vs. 2.3 (0.5–5.8) pg/ml, p = 0.03]. A significant inverse correlation was found between 25OHD and all these markers, even adjusted for age and sex. Hypovitaminosis D was prevalent in patients with severe ARDS, compared with the other groups (75% vs. 68% vs. 55%, p < 0.001), and 25OHD levels were lower in nonsurvivor patients. Conclusions: The relationship between 25OHD levels and inflammatory markers suggests that vitamin D status needs to be taken into account in the management of these patients. If vitamin D is a marker of poor prognosis or a possible risk factor with beneficial effects from supplementation, this still needs to be elucidated

    Mannose as a biomarker of coronary artery disease: Angiographic evidence and clinical significance

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    Background High mannose has previously associated with insulin resistance and cardiovascular disease (CVD). Our objective is to establish whether mannose is associated with anatomical evidence of coronary artery disease (CAD). Methods Plasma mannose concentrations were measured by liquid chromatography/tandem mass spectrometry in a discovery cohort (n = 513) and a validation cohort (n = 221) of carefully phenotyped individuals. In both cohorts CAD was quantitated using state-of-the-art imaging techniques (coronary computed coronary tomography angiography (CCTA), invasive coronary angiography and optical coherence tomography). Information on subsequent CVD events/death was collected. Associations of mannose with angiographic variables and biomarkers were tested using univariate and multivariate regression models. Survival analysis was performed using the Kaplan-Meier estimator. Results Mannose was related to indices of CAD and features of plaque vulnerability. In the discovery cohort, mannose was a marker of quantity and quality of CCTA-proven CAD and subjects with a mannose level in the top quartile had a significantly higher risk of CVD events/death (p = 3.6e-5). In the validation cohort, mannose was significantly associated with fibrous cap thickness < 65 \u3bcm (odds ratio = 1.32 per each 10 \u3bcmol/L mannose change [95% confidence interval, 1.05\u20131.65]) and was an independent predictor of death (hazard ratio for mannose 65vs < 84.6 \u3bcmol/L: 4.0(95%CI, 1.4\u201311.3), p = 0.006)

    Introduzione al protocollo SIP

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    Laboratorio VoIP, pjsip

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    Cenni di sicurezza

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    Introduzione al IP Multimedia Subsystem

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    Estensioni SIP

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    Registratio & Location Server

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