400 research outputs found

    A quantification mechanism for assessing adherence to information security governance guidelines

    Get PDF
    Purpose: Boards of Directors and other organisational leaders make decisions about the information security governance systems to implement in their companies. The increasing number of cyber-breaches targeting businesses makes this activity inescapable. Recently, researchers have published comprehensive lists of recommended cyber measures, specifically to inform organisational boards. However, the young cybersecurity industry has still to confirm and refine these guidelines. As a starting point, it would be helpful for organisational leaders to know what other organisations are doing in terms of using these guidelines. In an ideal world, bespoke surveys would be developed to gauge adherence to guidelines, but this is not always feasible. What we often do have is data from existing cybersecurity surveys. The authors argue that such data could be repurposed to quantify adherence to existing information security guidelines, and this paper aims to propose, and test, an original methodology to do so. Design/methodology/approach: The authors propose a quantification mechanism to measure the degree of adherence to a set of published information security governance recommendations and guidelines targeted at organisational leaders. The authors test their quantification mechanism using a data set collected in a survey of 156 Italian companies on information security and privacy. Findings: The evaluation of the proposed mechanism appears to align with findings in the literature, indicating the validity of the present approach. An analysis of how different industries rank in terms of their adherence to the selected set of recommendations and guidelines confirms the usability of our repurposed data set to measure adherence. Originality/value: To the best of the authors’ knowledge, a quantification mechanism as the one proposed in this study has never been proposed, and tested, in the literature. It suggests a way to repurpose survey data to determine the extent to which companies are implementing measures recommended by published cybersecurity guidelines. This way, the proposed mechanism responds to increasing calls for the adoption of research practices that minimise waste of resources and enhance research sustainability

    A Decision Aid for COPD patients considering inhaled steroid therapy: development and before and after pilot testing

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Decision aids (DA) are tools designed to help patients make specific and deliberative choices among disease management options. DAs can improve the quality of decision-making and reduce decisional conflict. An area not covered by a DA is the decision of a patient with chronic obstructive pulmonary disease (COPD) to use inhaled steroids which requires balancing the benefits and downsides of therapy.</p> <p>Methods</p> <p>We developed a DA for COPD patients considering inhaled steroid therapy using the Ottawa Decision Support Framework, the best available evidence for using inhaled steroid in COPD and the expected utility model. The development process involved patients, pulmonologists, DA developers and decision making experts. We pilot tested the DA with 8 COPD patients who completed an evaluation questionnaire, a knowledge scale, and a validated decisional conflict scale.</p> <p>Results</p> <p>The DA is a computer-based interactive tool incorporating four different decision making models. In the first part, the DA provides information about COPD as a disease, the different treatment options, and the benefits and downsides of using inhaled steroids. In the second part, it coaches the patient in the decision making process through clarifying values and preferences. Patients evaluated 10 out of 13 items of the DA positively and showed significant improvement on both the knowledge scale (p = 0.008) and the decisional conflict scale (p = 0.008).</p> <p>Conclusion</p> <p>We have developed a computer-based interactive DA for COPD patients considering inhaled steroids serving as a model for other DAs in COPD, in particular related to inhaled therapies. Future research should assess the DA effectiveness.</p

    Magnetic order in orbital models of the iron pnictides

    Full text link
    We examine the appearance of the experimentally-observed stripe spin-density-wave magnetic order in five different orbital models of the iron pnictide parent compounds. A restricted mean-field ansatz is used to determine the magnetic phase diagram of each model. Using the random phase approximation, we then check this phase diagram by evaluating the static spin susceptibility in the paramagnetic state close to the mean-field phase boundaries. The momenta for which the susceptibility is peaked indicate in an unbiased way the actual ordering vector of the nearby mean-field state. The dominant orbitally resolved contributions to the spin susceptibility are also examined to determine the origin of the magnetic instability. We find that the observed stripe magnetic order is possible in four of the models, but it is extremely sensitive to the degree of the nesting between the electron and hole Fermi pockets. In the more realistic five-orbital models, this order competes with a strong-coupling incommensurate state which appears to be controlled by details of the electronic structure below the Fermi energy. We conclude by discussing the implications of our work for the origin of the magnetic order in the pnictides.Comment: 19 pages, 19 figures; published version, typos corrected, references adde

    Interplay of ferromagnetism and triplet superconductivity in a Josephson junction

    Full text link
    In this paper we extend our earlier analysis of the novel Josephson effect in triplet superconductor--ferromagnet--triplet superconductor (TFT) junctions [B. Kastening \emph{et al.}, Phys. Rev. Lett. {\bf{96}}, 047009 (2006)]. In our more general formulation of the TFT junction we allow for potential scattering at the barrier and an arbitrary orientation of the ferromagnetic moment. Several new effects are found upon the inclusion of these extra terms: for example, we find that a Josephson current can flow even when there is vanishing phase difference between the superconducting condensates on either side of the barrier. The critical current for a barrier with magnetization parallel to the interface is calculated as a function of the junction parameters, and is found to display strong non-analyticities. Furthermore, the Josephson current switches first identified in our previous work are found to be robust features of the junction, while the unconventional temperature-dependence of the current is very sensitive to the extra terms in the barrier Hamiltonian.Comment: 24 pages, 15 figure

    Spin-Rotation Symmetry Breaking in the Superconducting State of CuxBi2Se3

    Full text link
    Spontaneous symmetry breaking is an important concept for understanding physics ranging from the elementary particles to states of matter. For example, the superconducting state breaks global gauge symmetry, and unconventional superconductors can break additional symmetries. In particular, spin rotational symmetry is expected to be broken in spin-triplet superconductors. However, experimental evidence for such symmetry breaking has not been conclusively obtained so far in any candidate compounds. Here, by 77Se nuclear magnetic resonance measurements, we show that spin rotation symmetry is spontaneously broken in the hexagonal plane of the electron-doped topological insulator Cu0.3Bi2Se3 below the superconducting transition temperature Tc=3.4 K. Our results not only establish spin-triplet superconductivity in this compound, but may also serve to lay a foundation for the research of topological superconductivity

    Origin and control of spin currents in a magnetic triplet Josephson junction

    Full text link
    We study the appearance of a Josephson spin current in a model triplet superconductor junction with a magnetically-active tunnelling barrier. We find three distinct mechanisms for producing a spin current, and we provide a detailed discussion of the symmetry properties and the physical origins of each. By combining these three basic mechanisms, we find that it is possible to exercise fine control over the spin currents. In particular, we show that unlike the charge current, the spin currents on either side of the barrier need not be identical.Comment: 5 pages, 4 figures, RevTe

    Gap symmetry and structure of Fe-based superconductors

    Full text link
    The recently discovered Fe-pnictide and chalcogenide superconductors display low-temperature properties suggesting superconducting gap structures which appear to vary substantially from family to family, and even within families as a function of doping or pressure. We propose that this apparent nonuniversality can actually be understood by considering the predictions of spin fluctuation theory and accounting for the peculiar electronic structure of these systems, coupled with the likely 'sign-changing s-wave' (s\pm) symmetry. We review theoretical aspects, materials properties and experimental evidence relevant to this suggestion, and discuss which further measurements would be useful to settle these issues.Comment: 86 pages, revie

    Symmetry and Topology in Superconductors - Odd-frequency pairing and edge states -

    Full text link
    Superconductivity is a phenomenon where the macroscopic quantum coherence appears due to the pairing of electrons. This offers a fascinating arena to study the physics of broken gauge symmetry. However, the important symmetries in superconductors are not only the gauge invariance. Especially, the symmetry properties of the pairing, i.e., the parity and spin-singlet/spin-triplet, determine the physical properties of the superconducting state. Recently it has been recognized that there is the important third symmetry of the pair amplitude, i.e., even or odd parity with respect to the frequency. The conventional uniform superconducting states correspond to the even-frequency pairing, but the recent finding is that the odd-frequency pair amplitude arises in the spatially non-uniform situation quite ubiquitously. Especially, this is the case in the Andreev bound state (ABS) appearing at the surface/interface of the sample. The other important recent development is on the nontrivial topological aspects of superconductors. As the band insulators are classified by topological indices into (i) conventional insulator, (ii) quantum Hall insulator, and (iii) topological insulator, also are the gapped superconductors. The influence of the nontrivial topology of the bulk states appears as the edge or surface of the sample. In the superconductors, this leads to the formation of zero energy ABS (ZEABS). Therefore, the ABSs of the superconductors are the place where the symmetry and topology meet each other which offer the stage of rich physics. In this review, we discuss the physics of ABS from the viewpoint of the odd-frequency pairing, the topological bulk-edge correspondence, and the interplay of these two issues. It is described how the symmetry of the pairing and topological indices determines the absence/presence of the ZEABS, its energy dispersion, and properties as the Majorana fermions.Comment: 91 pages, 38 figures, Review article, references adde
    • …
    corecore