8,054 research outputs found

    Can price transparency contribute to more affordable patient access to medicines?

    Get PDF
    No abstract available

    Artinian Gorenstein algebras with linear resolutions

    Full text link
    Fix a pair of positive integers d and n. We create a ring R and a complex G of R-modules with the following universal property. Let P be a polynomial ring in d variables over a field and let I be a grade d Gorenstein ideal in P which is generated by homogeneous forms of degree n. If the resolution of P/I by free P-modules is linear, then there exists a ring homomorphism from R to P such that P tensor G is a minimal homogeneous resolution of P/I by free P-modules. Our construction is coordinate free

    A Hybrid Model of Neutrino Masses and Oscillations: Bulk Neutrinos in the Split-Fermion Scenario

    Get PDF
    Higher-dimensional models of neutrino physics with one or more right-handed neutrinos in the bulk have attracted considerable attention in recent years. However, a critical issue for such models is to find a way of introducing the required flavor dependence needed for generating neutrino oscillations. In this paper, we point out that a natural ``minimal'' framework that accomplishes this can be constructed by combining the bulk-neutrino hypothesis for right-handed neutrinos with the split-fermion scenario for left-handed neutrinos. This combination leads to a unique flavor signature for neutrino phenomenology which easily incorporates large flavor mixing angles. This hybrid scenario also has a number of additional important features. For example, one previous difficulty of the split-fermion scenario applied to neutrinos has been that the mass matrix is exponentially sensitive to neutrino displacements within the brane. However, in our hybrid scenario, the interactions between the brane and bulk naturally convert this dependence from exponential to linear. Another important feature is that our hybrid scenario provides its own natural regulator for Kaluza-Klein sums. Thus, in our scenario, all Kaluza-Klein summations are manifestly finite, even in cases with multiple extra dimensions. But most importantly, our mechanism completely decouples the effective neutrino flavor mixing angles from the sizes of the overlaps between the neutrino wavefunctions within the brane. Thus, we are able to obtain large neutrino mixing angles even when these neutrinos have significant spatial separations and their overlaps vanish.Comment: 11 pages, LaTeX, 1 figur

    A minimal model for short-time diffusion in periodic potentials

    Full text link
    We investigate the dynamics of a single, overdamped colloidal particle, which is driven by a constant force through a one-dimensional periodic potential. We focus on systems with large barrier heights where the lowest-order cumulants of the density field, that is, average position and the mean-squared displacement, show nontrivial (non-diffusive) short-time behavior characterized by the appearance of plateaus. We demonstrate that this "cage-like" dynamics can be well described by a discretized master equation model involving two states (related to two positions) within each potential valley. Non-trivial predictions of our approach include analytic expressions for the plateau heights and an estimate of the "de-caging time" obtained from the study of deviations from Gaussian behaviour. The simplicity of our approach means that it offers a minimal model to describe the short-time behavior of systems with hindered dynamics.Comment: 8 pages, 6 figure

    Separation of (3.14C) 3-Hydroxy.3-methylglutaric acid from (3_14C) 3-Hydroxy-3-methylglutaryl CoA using Sephadex G-15 column chromatography

    Get PDF
    A new method has been developed for the separation of (3- 14C) 3-Hydroxy-3-methylglutaric acid from a (3-14C) 3-Hydroxy-3-methylglutaryl CoA preparation using Sephadex G-15 column chromatography. This method is simple, rapid and is useful in studies where the preparation of (3_ 14C) 3-Hyd1'oxy-3-methylglutaryl CoA is required to bef1'eef1'Om (3_ 14C) 3-Hydroxy-3-methylgluta1'ic acid contamination

    Comment on "Why interference phenomena do not capture the essence of quantum theory" by Catani et al

    Full text link
    It was recently argued by Catani et al that it is possible to reproduce the phenomenology of the double-slit experiment with a deterministic, local, and classical model (arXiv:2111.13727). The stated aim of their argument is to falsify the claim made by Feynman (in his third book of Lectures on Physics) that the double-slit experiment is "impossible, absolutely impossible, to explain in any classical way" and that it "contains the only mystery" of quantum mechanics. We here want to point out some problems with their argument, and defend Feynman's position.Comment: 3 pages, no figures, comments welcom
    corecore