92 research outputs found

    Confidential execution of cloud services

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    In this paper, we present Confidential Domain of Execution (CDE), a mechanism for achieving confidential execution of software in an otherwise untrusted environment, e.g., at a Cloud Service Provider. This is achieved by using an isolated execution environment in which any communication with the outside untrusted world is forcibly encrypted by trusted hardware. The mechanism can be useful to overcome the challenging issues in guaranteeing confidential execution in virtualized infrastructures, including cloud computing and virtualized network functions, among other scenarios. Moreover, the proposed mechanism does not suffer from the performance drawbacks typical of other solutions proposed for secure computing, as highlighted by the presented novel validation results. Copyright © 2014 SCITEPRESS - Science and Technology Publications

    End-to-end service quality for cloud applications

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    This paper aims to highlight the importance of End-to-End (E2E) service quality for cloud scenarios, with focus on telecom carrier-grade services. In multi-tenant distributed and virtualized cloud infrastructures, enhanced resource sharing raises issues in terms of performance stability and reliability. Moreover, the heterogeneity of business entities responsible for the cloud service delivery, threatens the possibility of offering precise E2E service levels. Setting up proper Service-Level Agreements (SLAs) among the involved players, may become overly challenging. However, problems may be mitigated by a thoughtful intervention of standardization. The paper reviews some of the most important efforts in research and industry to tackle E2E service quality and concludes with some recommendations for additional research and/or standardization effort required to be able to deploy mission critical or interactive real-time services with high demands on service quality, reliability and predictability on cloud platforms. © 2013 Springer International Publishing

    Optimization of traffic flows in multiservice telecomunications networks

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    This dissertation investigates routing optimization in IP telecommunication networks, under normal working conditions as well as under failure conditions. The main objectives of the present optimization procedure are the minimization of the maximum link utilization in the network and to provide a configuration that guarantees a 100% survivability degree. Traditionally two different steps are used to achieve this goal. The first one aims to solve the well known “General Routing Problem (GRP)” in order to find the optimal routing network configuration and, successively, a set of “optimal” backup paths is found in order to guarantee network survivability. Furthermore, traditional survivable techniques assume that the planning tasks are performed in a network control center while restoration schemes are implemented distributively in network nodes. In this dissertation innovative linear programming models are presented that, making use of the Multi Protocol Label Switching – Traffic Engineering (MPLS-TE) techniques and IS-IS/OSPF IP routing protocol, melt routing and survivability requirements. The models are extremely flexible, thus it is possible to improve the objective function in order to fit itself to newer applications and/or traffic typologies. The models presented in this dissertation help Internet Service Providers to optimize their network resources and to guarantee connectivity in case of failure, while still be able to offer a good quality of service

    Brokering SLAs for end-to-end QoS in cloud computing

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    In this paper, we present a brokering logic for providing precise end-to-end QoS levels to cloud applications distributed across a number of different business actors, such as network service providers (NSP) and cloud providers (CSP). The broker composes a number of available offerings from each provider, in a way that respects the QoS application constraints while minimizing costs incurred by cloud consumers. Copyright © 2014 SCITEPRESS - Science and Technology Publications

    Data centre optimisation enhanced by software defined networking

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    Contemporary Cloud Computing infrastructures are being challenged by an increasing demand for evolved cloud services characterised by heterogeneous performance requirements including real-time, data-intensive and highly dynamic workloads. The classical way to deal with dynamicity is to scale computing and network resources horizontally. However, these techniques must be coupled effectively with advanced routing and switching in a multi-path environment, mixed with a high degree of flexibility to support dynamic adaptation and live-migration of virtual machines (VMs). We propose a management strategy to jointly optimise computing and networking resources in cloud infrastructures, where Software Defined Networking (SDN) plays a key enabling role

    International Standard Problem No 50 – The University of Pisa contribution

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    The present paper deals with the participation of the University of Pisa in the last International Standard Problem (ISP) focused on system thermal hydraulic, which was led by the Korean Atomic Energy Research Institution (KAERI). The selected test was a Direct Vessel Injection (DVI) line break carried out at the ATLAS facility. University of Pisa participated, together with other eighteen institutions, in both blind and open phase of the analytical exercise pursuing its methodology for developing and qualifying a nodalization. Qualitative and quantitative analysis of the code results have been performed for both ISP-50 phases, the latter adopting the Fast Fourier Transfer Based Method (FFTBM). The experiment has been characterized by three dimensional behavior in downcomer and core region. Even though an attempt to reproduce these phenomena, by developing a fictitious three-dimensional nodalization has been realized, the obtained results were generally acceptable but not fully satisfactory in replicating 3D behavio

    BDNF/TrkB axis activation promotes epithelial-mesenchymal transition in idiopathic pulmonary fibrosis

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    Background: Neurotrophins (NT) belongs to a family of growth factors which promotes neurons survival and differentiation. Increasing evidence show that NT and their receptor are expressed in lung tissues suggesting a possible role in lung health and disease. Here we investigated the expression and functional role of the TrkB/BDNF axis in idiopathic pulmonary fibrotic lung (myo)fibroblasts. Methods: Lung fibroblast were isolated from IPF patients and characterized for the expression of mesenchymal markers in comparison to normal lung fibroblasts isolated from non-IPF controls. Results: BDNF treatment promoted mesenchymal differentiation and this effect was counteracted by the TrkB inhibitor K252a. In this regard, we showed that K252a treatment was able to control the expression of transcription factors involved in epithelial to mesenchymal transition (EMT). Accordingly, K252a treatment reduced matrix metalloproteinase-9 enzyme activity and E-cadherin expression while increased cytoplasmic β-catenin expression. Conclusions: Our results suggest that BDNF/TrkB axis plays a role in EMT promoting the acquisition of (myo)fibroblast cell phenotype in IPF. Targeting BDNF/TrkB seems to represent a viable approach in order to prevent EMT dependent lung fibrosis

    Discontinuously supervised aerobic training vs. physical activity promotion in the self-management of type 2 diabetes in older Italian patients: design and methods of the 'TRIPL-A' randomized controlled trial

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    Physical activity (PA) has health benefits for people with type 2 diabetes (T2D). Indeed, regular PA is considered an important part of any T2D management plan, yet most patients adopt a sedentary lifestyle. Exercise referral schemes (ERS) have the potential to effectively promote physical activity among T2D patients, and their effectiveness may be enhanced when they are supported by computer-based technologies. The 'TRIPL-A' study (i.e., a TRIal to promote PhysicaL Activity among patients in the young-old age affected by T2D) aims to assess if realizing an innovative ERS, based on a strong partnership among general practitioners, specialist physicians, exercise specialists, and patients, and supported by a web-based application (WBA), can effectively lead sedentary older T2D patients to adopt an active lifestyle

    Methodological issues in the observational studies conducted in older population: a narrative review

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    Introduction Well-conducted observational studies may represent valuable tools for getting insight to disease etiology, detecting the effect of age-related changes, and providing an important perspective on health risk factors and disabilities in an aging population. Nevertheless, this kind of research poses several challenges for researchers. The main aim of this narrative review was to address the potential methodological issues in performing the observational studies in the elderly, the factors that influence their participation, and the possible solutions for overcoming the barriers to research in this population. Methods Comprehensive search for the papers published in the period from January 1st 1980 until 31st July 2016 in English or Italian was conducted through MEDLINE, Scopus and Web of Science electronic databases. Findings from the included papers were finally summarized. Results In cohort studies, the following barriers were addressed: sample size calculation, ascertainment of the target population, frequency of data collection, exposure determination, multifactorial loss to follow-up (drop-outs), cognitive impairment, definition of confounders, and ethical aspects. Case-control studies were reported to be prone to the issues like ascertainment of cases and controls, willingness to participate, data accuracy, recall bias, issues related to patients’ multimorbidity, and cognitive impairment. Conclusions Important factors to consider in research in elderly people include: precise definition of the study population, well conducted recruitment process, engagement with family and home care staff, cognitive impairment assessment and the consequent relevant ethical and legal issues, relief of participant burden in order to minimize withdrawal, and engagement with the media
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