1,184 research outputs found

    The Geology of Evangeline and St. Landry Parishes, Louisiana.

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    Mathematical Modelling of Syphilis Transmission Dynamics: Impacts of Mass Media Report, Risky Sexual Behavior and Treatment

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    Abstract Syphilis is one of the deadly sexually-transmitted diseases. This paper studied the impacts of sexual behavior, mass media report and treatment of infected individuals on the dynamics of syphilis transmission. The analytical and numerical analyses of the model are presented. The disease free equilibrium of the model is both locally and globally asymptotic stable when the associated reproduction number is less than unity.  Analysis of the Reproduction number shows that it is not possible to control syphilis disease transmission if the rate of individuals practicing risky sexual behavior is high. Furthermore, the treatment of late (latent and tertiary) syphilis infection is beneficial to the infected individuals, but has no impact in the lowering of the reproduction number. This study suggests that the effective control strategy of syphilis must focus on lowering the number of individuals practicing risky sexual behavior and applying higher treatment rates for early syphilis infections. Furthermore, the media function should address the issues regarding safe sexual behavior. Keywords: Syphilis, sexually transmitted infection, Risky sexual behavior, Mass medi

    Feynman-Jackson integrals

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    We introduce perturbative Feynman integrals in the context of q-calculus generalizing the Gaussian q-integrals introduced by Diaz and Teruel. We provide analytic as well as combinatorial interpretations for the Feynman-Jackson integrals.Comment: Final versio

    qq-graded Heisenberg algebras and deformed supersymmetries

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    The notion of qq-grading on the enveloping algebra generated by products of q-deformed Heisenberg algebras is introduced for qq complex number in the unit disc. Within this formulation, we consider the extension of the notion of supersymmetry in the enveloping algebra. We recover the ordinary Z2\mathbb{Z}_2 grading or Grassmann parity for associative superalgebra, and a modified version of the usual supersymmetry. As a specific problem, we focus on the interesting limit q→−1q\to -1 for which the Arik and Coon deformation of the Heisenberg algebra allows to map fermionic modes to bosonic ones in a modified sense. Different algebraic consequences are discussed.Comment: 2 figure

    Bulk spectral function sum rule in QCD-like theories with a holographic dual

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    We derive the sum rule for the spectral function of the stress-energy tensor in the bulk (uniform dilatation) channel in a general class of strongly coupled field theories. This class includes theories holographically dual to a theory of gravity coupled to a single scalar field, representing the operator of the scale anomaly. In the limit when the operator becomes marginal, the sum rule coincides with that in QCD. Using the holographic model, we verify explicitly the cancellation between large and small frequency contributions to the spectral integral required to satisfy the sum rule in such QCD-like theories.Comment: 16 pages, 2 figure

    New connection formulae for some q-orthogonal polynomials in q-Askey scheme

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    New nonlinear connection formulae of the q-orthogonal polynomials, such continuous q-Laguerre, continuous big q-Hermite, q-Meixner-Pollaczek and q-Gegenbauer polynomials, in terms of their respective classical analogues are obtained using a special realization of the q-exponential function as infinite multiplicative series of ordinary exponential function

    In Memoriam: Ralph P. Boas, Jr (1912-1992)

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    Color-coordinate system from a 13th-century account of rainbows.

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    We present a new analysis of Robert Grosseteste’s account of color in his treatise De iride (On the Rainbow), dating from the early 13th century. The work explores color within the 3D framework set out in Grosseteste’s De colore [see J. Opt. Soc. Am. A 29, A346 (2012)], but now links the axes of variation to observable properties of rainbows. We combine a modern understanding of the physics of rainbows and of human color perception to resolve the linguistic ambiguities of the medieval text and to interpret Grosseteste’s key terms

    History : a medieval multiverse.

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    Solving the Frustrated Spherical Model with q-Polynomials

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    We analyse the Spherical Model with frustration induced by an external gauge field. In infinite dimensions, this has been recently mapped onto a problem of q-deformed oscillators, whose real parameter q measures the frustration. We find the analytic solution of this model by suitably representing the q-oscillator algebra with q-Hermite polynomials. We also present a related Matrix Model which possesses the same diagrammatic expansion in the planar approximation. Its interaction potential is oscillating at infinity with period log(q), and may lead to interesting metastability phenomena beyond the planar approximation. The Spherical Model is similarly q-periodic, but does not exhibit such phenomena: actually its low-temperature phase is not glassy and depends smoothly on q.Comment: Latex, 14 pages, 2 eps figure
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