30 research outputs found

    Exact diagonalization study of the Hubbard-parametrized four-spin ring exchange model on a square lattice

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    We have used exact numerical diagonalization to study the excitation spectrum and the dynamic spin correlations in the s=1/2s=1/2 next-next-nearest neighbor Heisenberg antiferromagnet on the square lattice, with additional 4-spin ring exchange from higher order terms in the Hubbard expansion. We have varied the ratio between Hubbard model parameters, t/Ut/U, to obtain different relative strengths of the exchange parameters, while keeping electrons localized. The Hubbard model parameters have been parametrized via an effective ring exchange coupling, JrJ_r, which have been varied between 0JJ and 1.5JJ. We find that ring exchange induces a quantum phase transition from the (π,π)(\pi, \pi) ordered Ne\`el state to a (π/2,π/2)(\pi/2, \pi/2) ordered state. This quantum critical point is reduced by quantum fluctuations from its mean field value of Jr/J=2J_r/J = 2 to a value of 1.1\sim 1.1. At the quantum critical point, the dynamical correlation function shows a pseudo-continuum at qq-values between the two competing ordering vectors

    Targeted prevention in primary care aimed at lifestyle-related diseases:a study protocol for a non-randomised pilot study

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    Background: The consequences of lifestyle-related disease represent a major burden for the individual as well as for society at large. Individual preventive health checks to the general population have been suggested as a mean to reduce the burden of lifestyle-related diseases, though with mixed evidence on effectiveness. Several systematic reviews, on the other hand, suggest that health checks targeting people at high risk of chronic lifestyle-related diseases may be more effective. The evidence is however very limited. To effectively target people at high risk of lifestyle-related disease, there is a substantial need to advance and implement evidence-based health strategies and interventions that facilitate the identification and management of people at high risk. This paper reports on a non-randomized pilot study carried out to test the acceptability, feasibility and short-term effects of a healthcare intervention in primary care designed to systematically identify persons at risk of developing lifestyle-related disease or who engage in health-risk behavior, and provide targeted and coherent preventive services to these individuals. Methods: The intervention took place over a three-month period from September 2016 to December 2016. Taking a two-pronged approach, the design included both a joint and a targeted intervention. The former was directed at the entire population, while the latter specifically focused on patients at high risk of a lifestyle-related disease and/or who engage in health-risk behavior. The intervention was facilitated by a digital support system. The evaluation of the pilot will comprise both quantitative and qualitative research methods. All outcome measures are based on validated instruments and aim to provide results pertaining to intervention acceptability, feasibility, and short-term effects. Discussion: This pilot study will provide a solid empirical base from which to plan and implement a full-scale randomized study with the central aim of determining the efficacy of a preventive health intervention. Trial registration: Registered at Clinical Trial Gov (Unique Protocol ID: TOFpilot2016). Registered 29 April 2016. The study adheres to the SPIRIT guidelines

    Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action

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    Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or “golden rules,” for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice

    The role of \u27professional advisors on financial matters\u27 in entrepreneurial networks

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    This study investigated the influence that 'professional advisors on financial matters' have in comparison with other people with whom entrepreneurs discuss their venture. Based on follow-up surveys completed in relation to the Danish participation in the Global Entrepreneurship Monitor (GEM) survey, it was found that professional advisors on financial matters only play a minor role in the two early phases of the entrepreneurial process before the venture is actually started. It was further revealed that the ties between professional advisors on financial matters and entrepreneurs often are weaker than the ties entrepreneurs have with others in their discussion network. Two practical implications for professional advisors on financial matters emerged from the study
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