2,495 research outputs found
Dual Superconductors and SU(2) Yang-Mills
We propose that the SU(2) Yang-Mills theory can be interpreted as a two-band
dual superconductor with an interband Josephson coupling. We discuss various
consequences of this interpretation including electric flux quantization,
confinement of vortices with fractional flux, and the possibility that a closed
vortex loop exhibits exotic exchange statistics
On correlation between protein secondary structure, backbone bond angles, and side-chain orientations
We investigate the fine structure of the sp3 hybridized covalent bond
geometry that governs the tetrahedral architecture around the central
C carbon of a protein backbone, and for this we develop new
visualization techniques to analyze high resolution X-ray structures in Protein
Data Bank. We observe that there is a correlation between the deformations of
the ideal tetrahedral symmetry and the local secondary structure of the
protein. We propose a universal coarse grained energy function to describe the
ensuing side-chain geometry in terms of the C carbon orientations. The
energy function can model the side-chain geometry with a sub-atomic precision.
As an example we construct the C-C structure of HP35 chicken
villin headpiece. We obtain a configuration that deviates less than 0.4 \.A in
root-mean-square distance from the experimental X-ray structure
Elastic Energy and Phase Structure in a Continuous Spin Ising Chain with Applications to the Protein Folding Problem
We present a numerical Monte Carlo analysis of a continuos spin Ising chain
that can describe the statistical proterties of folded proteins. We find that
depending on the value of the Metropolis temperature, the model displays the
three known nontrivial phases of polymers: At low temperatures the model is in
a collapsed phase, at medium temperatures it is in a random walk phase, and at
high temperatures it enters the self-avoiding random walk phase. By
investigating the temperature dependence of the specific energy we confirm that
the transition between the collapsed phase and the random walk phase is a phase
transition, while the random walk phase and self-avoiding random walk phase are
separated from each other by a cross-over transition. We also compare the
predictions of the model to a phenomenological elastic energy formula, proposed
by Huang and Lei to describe folded proteins.Comment: 12 pages, 23 figures, RevTeX 4.
Abelian and Non-Abelian Induced Parity Breaking Terms at Finite Temperature
We compute the exact canonically induced parity breaking part of the
effective action for 2+1 massive fermions in particular Abelian and non Abelian
gauge field backgrounds. The method of computation resorts to the chiral
anomaly of the dimensionally reduced theory.Comment: 13 pages, RevTeX, no figure
What is the best treatment for pertussis?
A short-term course of erythromycin, azithromycin, or clarithromycin is as effective as a long-term (2-week) erythromycin therapy in eradicating Bordetella pertussis from the nasopharynx (strength of recommendation [SOR]: A; based on one meta-analysis of randomized controlled trials [RCTs]). Evidence is insufficient to determine the benefit of antibiotic prophylaxis for pertussis contacts. However, due to high mortality and morbidity, prophylaxis is recommended for families who have an infant less than 6 months old (SOR: C; based on expert opinion)
Expressive Harms, Bizarre Districts, and Voting Rights: Evaluating Election-District Appearances After \u3cem\u3eShaw v. Reno\u3c/em\u3e
This article attempts to define the constitutional principles that characterize Shaw and to suggest how those principles might be applied in a consistent, meaningful way. Part I, in which we argue that Shaw must be understood to rest on a distinctive conception of the kinds of harms against which the Constitution protects, is the theoretical heart of the article. We call these expressive harms, as opposed to more familiar, material harms. In Part II, we briefly survey the history of previous, largely unsuccessful, efforts in other legal contexts to give principled content to these kinds of harms in redistricting. Parts III and IV then provide an alternative for evaluating district appearance by developing a quantitative approach for measuring district shapes that is most consistent with the theory of Shaw. These Parts are the empirical and social-scientific heart of the article. We apply our quantitative approach to congressional districts throughout the country, enabling meaningful comparisons between the congressional district at issue in Shaw and other districts. We also compare the shapes of congressional districts historically to test whether the district in Shaw is a distinctly recent phenomenon. In doing so, we identify the kind of districts most constitutionally vulnerable after Shaw. In Part V, we describe the further questions that lower courts must answer in deciding whether particular vulnerable districts ultimately fail the constitutional standard outlined in Shaw
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