4,801 research outputs found

    Intestinal tuberculosis

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    Purpose of reviewIntestinal tuberculosis (TB) is increasing due partly to the HIV pandemic. Its clinical presentation mimics inflammatory conditions such as Crohn's disease and malignancies, which are becoming more prevalent, so the diagnosis is problematic.Recent findingsGreater awareness of intestinal TB is needed, both in countries where TB is endemic and developed countries with immigrant populations. Some strains of Mycobacterium tuberculosis are associated with more extrapulmonary disease and greater dissemination, thereby exacerbating the rise in HIV-associated extrathoracic TB. Recent retrospective and prospective studies are leading to the development of diagnostic algorithms. A wide range of imaging techniques is available for sampling and diagnosis. New biochemical, immunological and molecular diagnostic methods are being developed but must be standardized and validated. Developments in drug delivery will facilitate oral therapy even in patients suffering from malabsorption.SummaryThere is an increasing consensus on the risk factors and clinical presentations of intestinal TB. Imaging techniques, coupled with fine needle biopsies, are useful aids to diagnosis, but most important is a greater awareness of the condition by clinicians

    Contextual barriers to mobile health technology in African countries: a perspective piece

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    On a global scale, healthcare practitioners are now beginning to move from traditional desktop-based computer technologies towards mobile computing environments[1]. Consequently, such environments have received immense attention from both academia and industry, in order to explore these promising opportunities, apparent limitations, and implications for both theory and practice[2]. The application of mobile IT within a medical context, referred to as mobile health or mHealth, has revolutionised the delivery of healthcare services as mobile technologies offer the potential of retrieving, modifying and entering patient-related data/information at the point-of-care. As a component of the larger health informatics domain mHealth may be referred as all portable computing devices (e.g. mobile phones, mobile clinical assistants and medical sensors) used in a healthcare context to support the delivery of healthcare services

    Optimization methods applied to hybrid vehicle design

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    The use of optimization methods as an effective design tool in the design of hybrid vehicle propulsion systems is demonstrated. Optimization techniques were used to select values for three design parameters (battery weight, heat engine power rating and power split between the two on-board energy sources) such that various measures of vehicle performance (acquisition cost, life cycle cost and petroleum consumption) were optimized. The apporach produced designs which were often significant improvements over hybrid designs already reported on in the literature. The principal conclusions are as follows. First, it was found that the strategy used to split the required power between the two on-board energy sources can have a significant effect on life cycle cost and petroleum consumption. Second, the optimization program should be constructed so that performance measures and design variables can be easily changed. Third, the vehicle simulation program has a significant effect on the computer run time of the overall optimization program; run time can be significantly reduced by proper design of the types of trips the vehicle takes in a one year period. Fourth, care must be taken in designing the cost and constraint expressions which are used in the optimization so that they are relatively smooth functions of the design variables. Fifth, proper handling of constraints on battery weight and heat engine rating, variables which must be large enough to meet power demands, is particularly important for the success of an optimization study. Finally, the principal conclusion is that optimization methods provide a practical tool for carrying out the design of a hybrid vehicle propulsion system

    The Future of Particle Physics

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    After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities.Comment: Invited talk given at the International Conference on Fundamental Sciences: Mathematics and Theoretical Physics, Singapore, 13-17 March 200

    Quantum power correction to the Newton law

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    We have found the graviton contribution to the one-loop quantum correction to the Newton law. This correction results in interaction decreasing with distance as 1/r^3 and is dominated numerically by the graviton contribution. The previous calculations of this contribution to the discussed effect are demonstrated to be incorrect.Comment: 10 pages, 5 figures; numerical error corrected, few references adde

    Experimental Puzzles in Heavy Flavor Decays - Anomalously high η\eta' appearance in charmless strange B decays - Flavor SU(3) breaking in Charm Decays

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    Simple experimental tests are proposed which can clarify the origin for the anomalously high η\eta' appearance in charmless strange final states in BB decays and can investigate the the nature of SU(3) symmetry-breaking in weak heavy flavor decays.Comment: 13 page

    Constraints on the variability of quark masses from nuclear binding

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    Based on recent work on nuclear binding, we update and extend the anthropic constraints on the light quark masses, with results that are more tightly constrained than previously obtained. We find that heavy nuclei would fall apart (because the attractive nuclear central potential becomes too weak) if the sum of the light quark masses m_u+m_d would exceed their physical values by 64% (at 95% confidence level). We summarize the anthropic constraints that follow from requiring the existence both of heavy atoms and of hydrogen. With the additional assumption that the quark Yukawa couplings do not vary, these constraints provide a remarkably tight anthropic window for the Higgs vacuum expectation value: 0.39 < v/v_physical < 1.64.Comment: 21 pages, 7 figure