30 research outputs found

    Measuring Security: A Challenge for the Generation

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    This paper presents an approach to measuring computer security understood as a system property, in the category of similar properties, such as safety, reliability, dependability, resilience, etc. First, a historical discussion of measurements is presented, beginning with views of Hermann von Helmholtz in his 19th century work “Zählen und Messen”. Then, contemporary approaches related to the principles of measuring software properties are discussed, with emphasis on statistical, physical and software models. A distinction between metrics and measures is made to clarify the concepts. A brief overview of inadequacies of methods and techniques to evaluate computer security is presented, followed by a proposal and discussion of a practical model to conduct experimental security measurements

    A Cyber Physical Systems Perspective on the Real-time and Reliable Dissemination of Information in Intelligent Transportation Systems

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    Timely and reliable dissemination of traffic-related information to drivers is a key property that intelligent transportation systems (ITS) should support. Numerous impediments stemming due to (a) physical factors, such as mobility and speed of vehicles, density of vehicles, characteristics of the wireless radio channel, and power and bit rate of radio transceivers, and (b) cyber issues, such as MAC layer access point associations and address resolutions (ARP), network layer addressing, routing and handoffs, and transport layer retransmissions lead to unpredictability in the timely and reliable dissemination of information to drivers. This paper presents compelling arguments in favor of new research directions in this area that are based on a cyber-physical systems (CPS) perspective. In particular, this paper makes three contributions. First, it considers a vehicle-centric perspective to survey and study the physics-and cyber-imposed impediments to the timely and reliable dissemination of information. Second, it presents a promising CPS solution to overcome a subset of the impediments discovered. Third, it outlines lessons learned indicating the need for more focused research and realistic testbeds. The evaluations 1 www.macrothink.org/npa Network Protocols and Algorithm

    Fenoldopam use in a burn intensive care unit: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Fenoldopam mesylate is a highly selective dopamine-1 receptor agonist approved for the treatment of hypertensive emergencies that may have a role at low doses in preserving renal function in those at high risk for or with acute kidney injury (AKI). There is no data on low-dose fenoldopam in the burn population. The purpose of our study was to describe our use of low-dose fenoldopam (0.03-0.09 μg/kg/min) infusion in critically ill burn patients with AKI.</p> <p>Methods</p> <p>We performed a retrospective analysis of consecutive patients admitted to our burn intensive care unit (BICU) with severe burns from November 2005 through September 2008 who received low-dose fenoldopam. Data obtained included systolic blood pressure, serum creatinine, vasoactive medication use, urine output, and intravenous fluid. Patients on concomitant continuous renal replacement therapy were excluded. Modified inotrope score and vasopressor dependency index were calculated. One-way analysis of variance with repeated measures, Wilcoxson signed rank, and chi-square tests were used. Differences were deemed significant at p < 0.05.</p> <p>Results</p> <p>Seventy-seven patients were treated with low-dose fenoldopam out of 758 BICU admissions (10%). Twenty (26%) were AKI network (AKIN) stage 1, 14 (18%) were AKIN stage 2, 42 (55%) were AKIN stage 3, and 1 (1%) was AKIN stage 0. Serum creatinine improved over the first 24 hours and continued to improve through 48 hours (<it>p </it>< 0.05). There was an increase in systolic blood pressure in the first 24 hours that was sustained through 48 hours after initiation of fenoldopam (<it>p </it>< 0.05). Urine output increased after initiation of fenoldopam without an increase in intravenous fluid requirement (<it>p </it>< 0.05; <it>p </it>= NS). Modified inotrope score and vasopressor dependency index both decreased over 48 hours (<it>p </it>< 0.0001; <it>p </it>= 0.0012).</p> <p>Conclusions</p> <p>These findings suggest that renal function was preserved and that urine output improved without a decrease in systolic blood pressure, increase in vasoactive medication use, or an increase in resuscitation requirement in patients treated with low-dose fenoldopam. A randomized controlled trial is required to establish the efficacy of low-dose fenoldopam in critically ill burn patients with AKI.</p

    TBVAC2020: Advancing tuberculosis vaccines from discovery to clinical development

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    TBVAC2020 is a research project supported by the Horizon 2020 program of the European Commission (EC). It aims at the discovery and development of novel tuberculosis (TB) vaccines from preclinical research projects to early clinical assessment. The project builds on previous collaborations from 1998 onwards funded through the EC framework programs FP5, FP6, and FP7. It has succeeded in attracting new partners from outstanding laboratories from all over the world, now totaling 40 institutions. Next to the development of novel vaccines, TB biomarker development is also considered an important asset to facilitate rational vaccine selection and development. In addition, TBVAC2020 offers portfolio management that provides selection criteria for entry, gating, and priority settings of novel vaccines at an early developmental stage. The TBVAC2020 consortium coordinated by TBVI facilitates collaboration and early data sharing between partners with the common aim of working toward the development of an effective TB vaccine. Close links with funders and other consortia with shared interests further contribute to this goal

    A meta-analysis of N-acetylcysteine in contrast-induced nephrotoxicity: unsupervised clustering to resolve heterogeneity

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    <p>Abstract</p> <p>Background</p> <p>Meta-analyses of N-acetylcysteine (NAC) for preventing contrast-induced nephrotoxicity (CIN) have led to disparate conclusions. Here we examine and attempt to resolve the heterogeneity evident among these trials.</p> <p>Methods</p> <p>Two reviewers independently extracted and graded the data. Limiting studies to randomized, controlled trials with adequate outcome data yielded 22 reports with 2746 patients.</p> <p>Results</p> <p>Significant heterogeneity was detected among these trials (<it>I</it><sup>2 </sup>= 37%; <it>p </it>= 0.04). Meta-regression analysis failed to identify significant sources of heterogeneity. A modified L'Abbé plot that substituted groupwise changes in serum creatinine for nephrotoxicity rates, followed by model-based, unsupervised clustering resolved trials into two distinct, significantly different (<it>p </it>< 0.0001) and homogeneous populations (<it>I</it><sup>2 </sup>= 0 and <it>p </it>> 0.5, for both). Cluster 1 studies (<it>n </it>= 18; 2445 patients) showed no benefit (relative risk (RR) = 0.87; 95% confidence interval (CI) 0.68–1.12, <it>p </it>= 0.28), while cluster 2 studies (<it>n </it>= 4; 301 patients) indicated that NAC was highly beneficial (RR = 0.15; 95% CI 0.07–0.33, <it>p </it>< 0.0001). Benefit in cluster 2 was unexpectedly associated with NAC-induced decreases in creatinine from baseline (<it>p </it>= 0.07). Cluster 2 studies were relatively early, small and of lower quality compared with cluster 1 studies (<it>p </it>= 0.01 for the three factors combined). Dialysis use across all studies (five control, eight treatment; <it>p </it>= 0.42) did not suggest that NAC is beneficial.</p> <p>Conclusion</p> <p>This meta-analysis does not support the efficacy of NAC to prevent CIN.</p

    Threat Modeling for Security Assessment in Cyberphysical Systems

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    ABSTRACT In this paper, threat modeling issues in cyberphysical systems are discussed. First a generic model of a cyberphysical system is outlined, with an attack surface suitable for security analysis. Then, a case study of network communication in a road vehicle is presented, with its behavior modeled by a discrete time Markov chain, under the assumption that security violations can cause gradual degradation of functionality. Finally, two ways of numerical assessment of vulnerabilities are analyzed, to help better estimate probabilities of state changes in a Markov model
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