364 research outputs found
Privacy in an Ambient World
Privacy is a prime concern in today's information society. To protect\ud
the privacy of individuals, enterprises must follow certain privacy practices, while\ud
collecting or processing personal data. In this chapter we look at the setting where an\ud
enterprise collects private data on its website, processes it inside the enterprise and\ud
shares it with partner enterprises. In particular, we analyse three different privacy\ud
systems that can be used in the different stages of this lifecycle. One of them is the\ud
Audit Logic, recently introduced, which can be used to keep data private when it\ud
travels across enterprise boundaries. We conclude with an analysis of the features\ud
and shortcomings of these systems
Strong and Weak Policy Relations
Access control and privacy policy relations tend to focus on decision outcomes and are very sensitive to defined terms and state. Small changes or updates to a policy language or vocabulary may make two similar policies incomparable. To address this we develop two flexible policy relations derived from bisimulation in process calculi. Strong licensing compares the outcome of two policies strictly, similar to strong bisimulation. Weak licensing compares the outcome of policies more flexibly by ignoring irrelevant (non-conflicting) differences between outcomes, similar to weak bisimulation. We illustrate the relations using examples from P3P
Metrological characterization of a vision-based system for relative pose measurements with fiducial marker mapping for spacecrafts
An improved approach for the measurement of the relative pose between a target and a chaser spacecraft is presented. The selected method is based on a single camera, which can be mounted on the chaser, and a plurality of fiducial markers, which can be mounted on the external surface of the target. The measurement procedure comprises of a closed-form solution of the Perspective from n Points (PnP) problem, a RANdom SAmple Consensus (RANSAC) procedure, a non-linear local optimization and a global Bundle Adjustment refinement of the marker map and relative poses. A metrological characterization of the measurement system is performed using an experimental set-up that can impose rotations combined with a linear translation and can measure them. The rotation and position measurement errors are calculated with reference instrumentations and their uncertainties are evaluated by the Monte Carlo method. The experimental laboratory tests highlight the significant improvements provided by the Bundle Adjustment refinement. Moreover, a set of possible influencing physical parameters are defined and their correlations with the rotation and position errors and uncertainties are analyzed. Using both numerical quantitative correlation coefficients and qualitative graphical representations, the most significant parameters for the final measurement errors and uncertainties are determined. The obtained results give clear indications and advice for the design of future measurement systems and for the selection of the marker positioning on a satellite surface
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When study site contributes to outcomes in a multi-center randomized trial: a secondary analysis of decisional conflict in men with localized prostate cancer
Purpose Evaluate baseline factors that may explain the influence of study site on decisional conflict (DC) in men from the Personal Patient Profile: Prostate (P3P) randomized trial. Materials and methods 476 cases from 5 P3P sites were included. Participants completed baseline demographic assessments, 4 subscales of the DC scale at baseline (uncertainty, informed, values clarity, and support), the Expanded Prostate Cancer Index Composite (short form) and the State-Trait Anxiety Inventory. Site data regarding typical practices were collected. Linear regressions were used to model the relation between baseline DC scores and study site adjusting for the list of variables. Results: Baseline decisional uncertainly (p = 0.001) and informed (p = 0.03) subscales were significantly different across sites. Participant demographic and baseline measures were significantly different (p < 0.05) between sites except for trait anxiety. We identified participant level factors that explained study site differences at baseline for the decisional uncertainty and values clarity subscales: a preferred treatment choice at study entry, whether the study program was accessed at home vs. in clinic, number of doctors consulted pre-study, working status, state anxiety, information from the media or a health care provider, and perceived knowledge level. State anxiety was associated with higher DC across all subscales. Conclusions: Individual characteristics of men seeking consultation for LPC were associated with DC at baseline, not the site alone; anxiety contributed to higher conflict. These findings will inform future development and implementation of the P3P and other decision support interventions. Trial registration NCT00692653
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Highly-branched poly(N-isopropyl acrylamide) functionalised with pendant Nile red and chain end vancomycin for the detection of Gram-positive bacteria
YesThis study shows how highly branched poly(N-isopropyl acrylamide) (HB-PNIPAM) with a chain pendant solvatochromic dye (Nile red) could provide a fluorescence signal, as end groups bind to bacteria and chain segments become desolvated, indicating the presence of bacteria. Vancomycin was attached to chain ends of HB-PNIPAM or as pendant groups on linear polymers each containing Nile red. Location of the dye was varied between placement in the core of the branched polymer coil or the outer domains. Both calorimetric and fluorescence data showed that branched polymers responded to binding of both the peptide target (D-Ala-D-Aa) and bacteria in a different manner than analogous linear polymers; binding and response was more extensive in the branched variant. The fluorescence data showed that only segments located in the outer domains of branched polymers responded to binding of Gram-positive bacteria with little response when linear analogous polymer or branched polymer with the dye in the inner core was exposed to Staphylococcus aureus.Innovate UK/Smith and Nephew Ltd. (UK) (TSB 103988) and by MRC (MR/N501888/2)
Generation of novel cationic antimicrobial peptides from natural non-antimicrobial sequences by acid-amide substitution
<p>Abstract</p> <p>Background</p> <p>Cationic antimicrobial peptides (CAMPs) are well recognized to be promising as novel antimicrobial and antitumor agents. To obtain novel skeletons of CAMPs, we propose a simple strategy using acid-amide substitution (i.e. Glu→Gln, Asp→Asn) to confer net positive charge to natural non-antimicrobial sequences that have structures distinct from known CAMPs. The potential of this strategy was verified by a trial study.</p> <p>Methods</p> <p>The pro-regions of nematode cecropin P1-P3 (P1P-P3P) were selected as parent sequences. P1P-P3P and their acid-amide-substituted mutants (NP1P-NP3P) were chemically synthesized. Bactericidal and membrane-disruptive activities of these peptides were evaluated. Conformational changes were estimated from far-ultraviolet circular dichroism (CD) spectra.</p> <p>Results</p> <p>NP1P-NP3P acquired potent bactericidal activities via membrane-disruption although P1P-P3P were not antimicrobial. Far-ultraviolet CD spectra of NP1P-NP3P were similar to those of their parent peptides P1P-P3P, suggesting that NP1P-NP3P acquire microbicidal activity without remarkable conformational changes. NP1P-NP3P killed bacteria in almost parallel fashion with their membrane-disruptive activities, suggesting that the mode of action of those peptides was membrane-disruption. Interestingly, membrane-disruptive activity of NP1P-NP3P were highly diversified against acidic liposomes, indicating that the acid-amide-substituted nematode cecropin pro-region was expected to be a unique and promising skeleton for novel synthetic CAMPs with diversified membrane-discriminative properties.</p> <p>Conclusions</p> <p>The acid-amide substitution successfully generated some novel CAMPs in our trial study. These novel CAMPs were derived from natural non-antimicrobial sequences, and their sequences were completely distinct from any categories of known CAMPs, suggesting that such mutated natural sequences could be a promising source of novel skeletons of CAMPs.</p
Examined Lives: Informational Privacy and the Subject as Object
In the United States, proposals for informational privacy have proved enormously controversial. On a political level, such proposals threaten powerful data processing interests. On a theoretical level, data processors and other data privacy opponents argue that imposing restrictions on the collection, use, and exchange of personal data would ignore established understandings of property, limit individual freedom of choice, violate principles of rational information use, and infringe data processors\u27 freedom of speech. In this article, Professor Julie Cohen explores these theoretical challenges to informational privacy protection. She concludes that categorical arguments from property, choice, truth, and speech lack weight, and mask fundamentally political choices about the allocation of power over information, cost, and opportunity. Each debate, although couched in a rhetoric of individual liberty, effectively reduces individuals to objects of choices and trades made by others. Professor Cohen argues, instead, that the debate about data privacy protection should be grounded in an appreciation of the conditions necessary for individuals to develop and exercise autonomy in fact, and that meaningful autonomy requires a degree of freedom from monitoring, scrutiny, and categorization by others. The article concludes by calling for the design of both legal and technological tools for strong data privacy protection
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