30,671 research outputs found

    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

    Unified theory of the semi-collisional tearing mode and internal kink mode in a hot tokamak: implications for sawtooth modelling

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    In large hot tokamaks like JET, the width of the reconnecting layer for resistive modes is determined by semi-collisional electron dynamics and is much less than the ion Larmor radius. Firstly a dispersion relation valid in this regime is derived which provides a unified description of drift-tearing modes, kinetic Alfven waves and the internal kink mode at low beta. Tearing mode stability is investigated analytically recovering the stabilising ion orbit effect, obtained previously by Cowley et al. [Phys. Fluids (29) 3230 1986], which implies large values of the tearing mode stability parameter "Delta prime" are required for instability. Secondly, at high beta it is shown that the tearing mode interacts with the kinetic Alfven wave and that there is an absolute stabilisation for all "Delta prime" due to the shielding effects of the electron temperature gradients, extending the result of Drake et. al [Phys. Fluids (26) 2509 1983] to large ion orbits. The nature of the transition between these two limits at finite values of beta is then elucidated. The low beta formalism is also relevant to the m=n=1 tearing mode and the dissipative internal kink mode, thus extending the work of Pegoraro et al. [Phys. Fluids B (1) 364 1989] to a more realistic electron model incorporating temperature perturbations, but then the smallness of the dissipative internal kink mode frequency is exploited to obtain a new dispersion relation valid at arbitrary beta. A diagram describing the stability of both the tearing mode and dissipative internal kink mode, in the space of "Delta prime" and beta, is obtained. The trajectory of the evolution of the current profile during a sawtooth period can be plotted in this diagram, providing a model for the triggering of a sawtooth crash.Comment: 37 pages, updated version, accepted, to appear on Plasma Physics and Controlled Fusio

    The Effect of Plasma Beta on High-n Ballooning Stability at Low Magnetic Shear

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    An explanation of the observed improvement in H-mode pedestal characteristics with increasing core plasma pressure or poloidal beta, as observed in MAST and JET, is sought in terms of the impact of the Shafranov shift, d', on ideal ballooning MHD stability.Comment: 18 pages, 5 figures. This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IoP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

    Differential equations for the cuspoid canonical integrals

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    Differential equations satisfied by the cuspoid canonical integrals I_n(a) are obtained for arbitrary values of n≥2, where n−1 is the codimension of the singularity and a=(ɑ_1,ɑ_2,...,ɑ_(n−1)). A set of linear coupled ordinary differential equations is derived for each step in the sequence I_n(0,0,...,0,0) →I_n(0,0,...,0,ɑ_(n−1)) →I_n(0,0,...,ɑ_(n−2),ɑ_(n−1)) →...→I_n(0,ɑ_2,...,ɑ_(n−2),ɑ_(n−1)) →I_n(ɑ_1,ɑ_2,...,ɑ_n−2,ɑ_(n−1)). The initial conditions for a given step are obtained from the solutions of the previous step. As examples of the formalism, the differential equations for n=2 (fold), n=3 (cusp), n=4 (swallowtail), and n=5 (butterfly) are given explicitly. In addition, iterative and algebraic methods are described for determining the parameters a that are required in the uniform asymptotic cuspoid approximation for oscillating integrals with many coalescing saddle points. The results in this paper unify and generalize previous researches on the properties of the cuspoid canonical integrals and their partial derivatives

    MARKET CONDUCT IN THE U.S. READY-TO-EAT CEREAL INDUSTRY

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    The FTC's "shared monopoly" case was the focus of U.S. antitrust activity during the late 1970s, but prosecution of the cereal industry was terminated in 1981. We estimate the degree of market power in the industry, and find an increase in multilateral power after 1981.Marketing,

    STRUCTURAL CHANGE IN HIGHER EDUCATION: IMPLICATIONS FOR AGRICULTURAL ECONOMICS ACADEMIC PROGRAMS

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    Major changes affecting Agricultural Economics include: level and sources of funding, increased accountability, a renewed emphasis on teaching, increasing university and college linkages, an evolving student base, and the continuing adoption of educational technology. Major implications include: broader faculty teaching involvement, agribusiness program development, expanding multidisciplinary majors, Ph.D program modifications for teacher preparation, expanding professional M.S. degrees, graduate program size and specialization reductions, alternative financing of graduate education, and faculty training in teaching methods. Teaching represents a major growth opportunity for Agricultural Economics, but it remains to be seen whether the discipline takes advantage of this opportunity.Agribusiness, Accountability, Funding, Environmental, Undergraduate, Graduate, Multidisciplinary, Portfolio, Teaching/Communication/Extension/Profession,
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