215 research outputs found

    Synchronous oceanic spreading and continental rifting in West Antarctica

    Get PDF
    Magnetic anomalies associated with new ocean crust formation in the Adare Basin off north-western Ross Sea (43 – 26 Ma) can be traced directly into the Northern Basin that underlies the adjacent morphological continental shelf, implying a continuity in the emplacement of oceanic crust. Steep gravity gradients along the margins of the Northern Basin, particularly in the east, suggest that little extension and thinning of continental crust occurred before it ruptured and the new oceanic crust formed, unlike most other continental rifts and the Victoria Land Basin further south. A pre-existing weak crust and localisation of strain by strike slip faulting are proposed as the factors allowing the rapid rupture of continental crust

    K-shell photoionization of ground-state Li-like carbon ions [C3+^{3+}]: experiment, theory and comparison with time-reversed photorecombination

    Full text link
    Absolute cross sections for the K-shell photoionization of ground-state Li-like carbon [C3+^{3+}(1s2^22s 2^2S)] ions were measured by employing the ion-photon merged-beams technique at the Advanced Light Source. The energy ranges 299.8--300.15 eV, 303.29--303.58 eV and 335.61--337.57 eV of the [1s(2s2p)3^3P]2^2P, [1s(2s2p)1^1P]2^2P and [(1s2s)3^3S 3p]2^2P resonances, respectively, were investigated using resolving powers of up to 6000. The autoionization linewidth of the [1s(2s2p)1^1P]2^2P resonance was measured to be 27±527 \pm 5 meV and compares favourably with a theoretical result of 26 meV obtained from the intermediate coupling R-Matrix method. The present photoionization cross section results are compared with the outcome from photorecombination measurements by employing the principle of detailed balance.Comment: 3 figures and 2 table

    Automated Analysis in Feature Modelling and Product Configuration

    Get PDF
    The automated analysis of feature models is one of the thriving topics of research in the software product line and variability management communities that has attracted more attention in the last years. A recent literature review reported that more than 30 analysis operations have been identi ed and di erent analysis mechanisms have been proposed. Product con guration is a well established research eld with more than 30 years of successful applications in di erent industrial domains. Our hypothesis, that is not really new, is that these two independent areas of research have interesting synergies that have not been fully explored. To try to explore the potential synergies systematically, in this paper we provide a rapid review to bring together these previously disparate streams of work. We de ne a set of research questions and give a preliminary answer to some of them. We conclude that there are many research opportunities in the synergy of these independent areas.Ministerio de Ciencia e Innovación TIN2009- 07366Junta de Andalucía TIC-590

    Instrumentation for fluorescence lifetime measurement using photon counting

    Get PDF
    We describe the evolution of HORIBA Jobin Yvon IBH Ltd, and its time-correlated single-photon counting (TCSPC) products, from university research beginnings through to its present place as a market leader in fluorescence lifetime spectroscopy. The company philosophy is to ensure leading-edge research capabilities continue to be incorporated into instruments in order to meet the needs of the diverse range of customer applications, which span a multitude of scientific and engineering disciplines. We illustrate some of the range of activities of a scientific instrument company in meeting this goal and highlight by way of an exemplar the performance of the versatile DeltaFlex instrument in measuring fluorescence lifetimes. This includes resolving fluorescence lifetimes down to 5 ps, as frequently observed in energy transfer, nanoparticle metrology with sub-nanometre resolution and measuring a fluorescence lifetime in as little as 60 μs for the study of transient species and kinetics

    Foreign investment, corporate governance and performance in the Chinese listed a share companies

    Get PDF
    We present a novel lens on the presence and impact of qualified foreign institutional investors (QFII) in top shareholdings of the non-financial domestically listed Chinese ‘A’ share firms. The initial results suggest that the presence of a QFII as a top shareholder in these companies is associated with their better performance, using both Tobin’s Q and ROA as the performance measures. Our models include variables representing corporate governance mechanisms, foreign legal person shares, a proxy for international affiliations and a number of time-variant firm characteristics. Economically, the coefficient of impact on the market measure is the more significant, while the effect of having a QFII in top shareholdings on both performance measures is empirically significant. Previously, studies have often ignored the potential for reverse causality beyond using lagged regressors. This is problematic. Therefore, we follow up with a 2SLS instrumental variables and system GMM model to further mitigate this potential and find the empirical relationship holds. Contrary to earlier work on QFIIs and governance post-implementation of the QFII scheme, the findings from our models suggest that the presence of a QFII top shareholder augments market performance holding equal existing corporate governance mechanisms and other controls

    Emerging issues and current trends in assistive technology use 2007-1010: practising, assisting and enabling learning for all

    Get PDF
    Following an earlier review in 2007, a further review of the academic literature relating to the uses of assistive technology (AT) by children and young people was completed, covering the period 2007-2011. As in the earlier review, a tripartite taxonomy: technology uses to train or practise, technology uses to assist learning and technology uses to enable learning, was used in order to structure the findings. The key markers for research in this field and during these three years were user involvement, AT on mobile mainstream devices, the visibility of AT, technology for interaction and collaboration, new and developing interfaces and inclusive design principles. The paper concludes by locating these developments within the broader framework of the Digital Divide

    The General Practice Assessment Questionnaire (GPAQ) – Development and psychometric characteristics

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Continual quality improvement in primary care is an international priority. In the United Kingdom, the major initiative for improving quality of care is the Quality and Outcomes Framework (QoF) of the 2004 GP contract. Although the primary focus of the QoF is on clinical care, it is acknowledged that a comprehensive assessment of quality also requires valid and reliable measurement of the patient perspective, so financial incentives are included in the contract for general practices to survey patients' views. One questionnaire specified for use in the QoF is the General Practice Assessment Questionnaire (GPAQ). This paper describes the development of the GPAQ (with post-consultation and postal versions) and presents a preliminary examination of the psychometric properties of the questionnaire.</p> <p>Methods</p> <p>Description of scale development and preliminary analysis of psychometric characteristics (internal reliability, factor structure), based on a large dataset of routinely collected GPAQ surveys (n = 190,038 responses to the consultation version of GPAQ and 20,309 responses to the postal version) from practices in the United Kingdom during the 2005–6 contract year.</p> <p>Results</p> <p>Respondents tend to report generally favourable ratings. Responses were particularly skewed on the GP communication scale, though no more so than for other questionnaires in current use in the UK for which data were available. Factor analysis identified 2 factors that clearly relate to core concepts in primary care quality ('access' and 'interpersonal care') that were common to both version of the GPAQ. The other factors related to 'enablement' in the post-consultation version and 'nursing care' in the postal version.</p> <p>Conclusion</p> <p>This preliminary evaluation indicates that the scales of the GPAQ are internally reliable and that the items demonstrate an interpretable factor structure. Issues concerning the distributions of GPAQ responses are discussed. Potential further developments of the item content for the GPAQ are also outlined.</p
    corecore