237 research outputs found

    Quality management of surveillance multimedia streams via federated SDN controllers in Fiwi-iot integrated deployment environments

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    Traditionally, hybrid optical-wireless networks (Fiber-Wireless - FiWi domain) and last-mile Internet of Things edge networks (Edge IoT domain) have been considered independently, with no synergic management solutions. On the one hand, FiWi has primarily focused on high-bandwidth and low-latency access to cellular-equipped nodes. On the other hand, Edge IoT has mainly aimed at effective dispatching of sensor/actuator data among (possibly opportunistic) nodes, by using direct peer-to-peer and base station (BS)-assisted Internet communications. The paper originally proposes a model and an architecture that loosely federate FiWi and Edge IoT domains based on the interaction of FiWi and Edge IoT software defined networking controllers: The primary idea is that our federated controllers can seldom exchange monitoring data and control hints the one with the other, thus mutually enhancing their capability of end-to-end quality-aware packet management. To show the applicability and the effectiveness of the approach, our original proposal is applied to the notable example of multimedia stream provisioning from surveillance cameras deployed in the Edge IoT domain to both an infrastructure-side server and spontaneously interconnected mobile smartphones; our solution is able to tune the BS behavior of the FiWi domain and to reroute/prioritize traffic in the Edge IoT domain, with the final goal to reduce latency. In addition, the reported application case shows the capability of our solution of joint and coordinated exploitation of resources in FiWi and Edge IoT domains, with performance results that highlight its benefits in terms of efficiency and responsiveness

    BlockHealth: Blockchain-based secure and peer-to-peer health information sharing with data protection and right to be forgotten

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    Abstract To identify health risks in working environments, it is crucial for companies to share personal health data demonstrating to clients and suppliers their employees are healthy, while being compliant with data protection legislation. Based on these considerations, our Blockchain-based BlockHealth solution allows personal health data sharing with tamper proofing and data protection. Traditionally, the Blockchain guarantees data immutability but not confidentiality. On the contrary, BlockHealth stores in the Blockchain only hash values of data. Health data is stored in private databases managed by companies, thus also allowing to delete data in compliance with the right to be forgotten

    Evaluating Filtering Strategies for Decentralized Handover Prediction in the Wireless Internet

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    The rapid diffusion of heterogeneous forms of wireless connectivity is pushing the tremendous growth of the commercial interest in mobile services, i.e., distributed applications to portable wireless terminals that roam during service provisioning. In the case of both location-dependent mobile services and mobile services with session continuity requirements, there is a growing need for decentralized and lightweight solutions to predict cell handovers, in order to enable proactive service management operations that anticipate actual terminal reconnections at their newly visited cells. The paper discusses how to predict client handovers between IEEE 802.11 cells in a portable and completely decentralized way, only by exploiting RSSI monitoring and with no need of external global positioning systems. In particular, the paper focuses on proposing and comparing different filtering techniques for mitigating Received Signal Strength Indication abrupt fluctuations. Experimental results point out that i) filtering techniques can relevantly improve the efficiency and effectiveness of handover prediction, and ii) the choice of the most appropriate filtering solution to adopt should be made at provisioning time depending on specific service/system requirements, e.g., privileging minimum overhead vs. greater prediction proactivity

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

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    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

    Dependence of brain DTI maps of fractional anisotropy and mean diffusivity on the number of diffusion weighting directions

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    The rotational variance dependence of diffusion tensor imaging (DTI) derived parameters on the number of diffusion weighting directions (N) has been investigated by several Monte Carlo simulation studies. However, the dependence of fractional anisotropy (FA) and mean diffusivity (MD) maps on N, in terms of accuracy and contrast between different anatomical structures, has not been assessed in detail. This experimental study further investigated in vivo the effect of the number of diffusion weighting directions on DTI maps of FA and MD. Human brain FA and MD maps of six healthy subjects were acquired at 1.5T with varying N (6, 11, 19, 27, 55). Then, FA and MD mean values in high (FAH, MDH) and low (FAL, MDL) anisotropy segmented brain regions were measured. Moreover, the contrast-to-signal variance ratio (CVRFA, CVRMD) between the main white matter and the surrounding regions was calculated. Analysis of variance showed that FAL, FAH and CVRFA significantly (p 0.05) depend on N. Unlike MD values, FA values significantly vary with N. It is noteworthy that the observed variation is opposite in low and high anisotropic regions. In clinical studies, the effect of N may represent a confounding variable for anisotropy measurements and the employment of DTI acquisition schemes with high N (> 20) allows an increased CVR and a better visualization of white matter structures in FA maps

    Differential inhibition of the TGF-b signaling pathway in HCC cells using the small molecule inhibitor LY2157299 and the D10 monoclonal antibody against TGF-β receptor Type II

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    We investigated blocking the TGF-b signaling pathway in HCC using two small molecule inhibitors (LY2157299, LY2109761) and a neutralizing humanized antibody (D10) against TGF-bRII. LY2157299 and LY2109761 inhibited HCC cell migration on Laminin-5, Fibronectin, Vitronectin, Fibrinogen and Collagen-I and de novo phosphorylation of pSMAD2. LY2157299 inhibited HCC migration and cell growth independently of the expression levels of TGF-bRII. In contrast to LY2157299, D10 showed a reduction in pSMAD2 only after a short exposure. This study supports the use of LY2157299 in clinical trials, and presents new insights into TGF-b receptor cycling in cancer cells

    Super selective arterial embolization to treat radiation-induced hemorrhagic gastritis: a case report and review of the literature

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    Radiation-induced hemorrhagic gastritis (RIHG) is a rare but potentially fatal event following radiotherapy for locally advanced gastric cancer; the treatment of this condition is not standardized. Only few cases of RIHG have been reported, treated with different therapeutic approaches. Here we report the case of a 79-year-old patient who underwent subtotal gastrectomy for gastric cancer, followed by adjuvant chemo-radiotherapy. Approximately 3 months after the end of the treatment, she developed recurrent diffuse bleeding originating from the entire mucosa of the gastric pouch and from a marginal ulcer. As the bleeding was refractory to several endoscopic treatments and surgery was not indicated, the patient underwent two sessions of transcatheter selective arterial embolization, with resolution of bleeding. Arterial embolization has already been reported for the treatment of hemorrhagic cystitis, developing after irradiation of the pelvis for prostate, bladder, rectum, and cervix cancer. However, to our knowledge, it has never been reported as a treatment for hemorrhagic gastritis. Based on this case, we suggest arterial embolization as an option in the management of RIHG, when standard endoscopic treatment fails

    Seroprevalence of group B Coxsackieviruses: retrospective study in an Italian population

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    Purpose Group B Coxsackieviruses (CVB) include 6 serotypes (B1‐6) responsible for a wide range of clinical diseases. Since no recent seroepidemiologic data are available in Italy, the study aim was to investigate CVB seroprevalence in a wide Italian population. Methods The study retrospectively included 2,459 subjects referring to a large academic hospital in Rome (Italy) in the period 2004‐2016. Seroprevalence rates and neutralizing antibodies (nAb) titers were evaluated in relation to years of observation and subjects’ characteristics. Results Positivity for at least one serotype was detected in 69.1% of individuals. Overall, the prevalent serotype was B4, followed by B3 (33.3%), B5 (26.2%), B1 (12.7%), B2 (11.0%), and B6 (1.7%). For B2, a significant decrease in seroprevalence over years was observed. Positivity to at least one virus was 25.2% in children aged 0‐2 years, but significantly increased in pre‐school (3‐5 yr) (50.3%) and school (6‐10 yr) children (70.4%). Higher nAb responses for B3 and B4 were observed in children aged 3‐5 years. Conclusion A high overall CVB prevalence was found. Type‐specific variations in prevalence over time probably reflect the fluctuations in circulation typical of Enteroviruses. Children are at greater risk for CVB infection given the high number of seronegative subjects aged 0‐10 years
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