4,508 research outputs found

    Chiral Lagrangian and spectral sum rules for dense two-color QCD

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    We analytically study two-color QCD with an even number of flavors at high baryon density. This theory is free from the fermion sign problem. Chiral symmetry is broken spontaneously by the diquark condensate. Based on the symmetry breaking pattern we construct the low-energy effective Lagrangian for the Nambu-Goldstone bosons. We identify a new epsilon-regime at high baryon density in which the quark mass dependence of the partition function can be determined exactly. We also derive Leutwyler-Smilga-type spectral sum rules for the complex eigenvalues of the Dirac operator in terms of the fermion gap. Our results can in principle be tested in lattice QCD simulations.Comment: 24 pages, 1 table, no figur

    Long time, large scale limit of the Wigner transform for a system of linear oscillators in one dimension

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    We consider the long time, large scale behavior of the Wigner transform W_\eps(t,x,k) of the wave function corresponding to a discrete wave equation on a 1-d integer lattice, with a weak multiplicative noise. This model has been introduced in Basile, Bernardin, and Olla to describe a system of interacting linear oscillators with a weak noise that conserves locally the kinetic energy and the momentum. The kinetic limit for the Wigner transform has been shown in Basile, Olla, and Spohn. In the present paper we prove that in the unpinned case there exists γ0>0\gamma_0>0 such that for any γ(0,γ0]\gamma\in(0,\gamma_0] the weak limit of W_\eps(t/\eps^{3/2\gamma},x/\eps^{\gamma},k), as \eps\ll1, satisfies a one dimensional fractional heat equation tW(t,x)=c^(x2)3/4W(t,x)\partial_t W(t,x)=-\hat c(-\partial_x^2)^{3/4}W(t,x) with c^>0\hat c>0. In the pinned case an analogous result can be claimed for W_\eps(t/\eps^{2\gamma},x/\eps^{\gamma},k) but the limit satisfies then the usual heat equation

    An unusual foreign body migrating through time and tissues

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    BACKGROUND: Beside infections, foreign body incidences are amongst the most frequently encountered pathologies in pediatric otolaryngology. While inhaled foreign bodies represent an acute emergency, symptoms of ingested foreign bodies sometimes appear with some delay. Typically fishbones tend to go unnoticed in a first examination and become symptomatic by fever, odynodyspahgia and torticollis. Exceptionally, foreign bodies migrate and become manifest with a considerable delay. CASE REPORT: We present a case of a young girl who presented with an unusual foreign body which migrated through the cervical tissues causing repeated cervical tumescence's before being diagnosed. CONCLUSION: Repeated cervical abscesses or tumescence's in children or young patients should alert the treating physician to seek for an underlying pathology such as unnoticed foreign bodies or malformations (e.g. cysts). Further the scarce literature on these migrating foreign bodies is discussed

    Idiopathic Phantosmia: Outcome and Clinical Significance

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    Background/Aim: Little is known about the clinical significance of phantosmia. The literature on phantosmia indicates that this symptom has a wide range of differential diagnoses. However, most cases of phantosmia remain of unknown origin. Our goal was to follow up patients with idiopathic phantosmia, with special regard to improvement rates and possible severe health conditions preceded by phantosmia of unknown origin. Methods: Forty-four patients with idiopathic phantosmia which had consulted our Ear-Nose-Throat Smell and Taste Clinic over the last 10 years were contacted by telephone and underwent a structured medical interview. Results: None of the patients had eveloped any severe health condition or Parkinson’s disease. More than 5 years after the occurrence of hantosmia, more than 50% of the patients experienced disappearance (31.8%) or improvement (25%). In the remaining cases, phantosmia did not change (38.7%) or became worse ( ! 5%). Conclusion: The main findings of the present study were that idiopathic phantosmia improves or disappears in almost two thirds of the patients after more than 5 years, and that idiopathic phantosmia seems to be more likely a harmless symptom rather than a reliable predictor of early Parkinson’s disease or other severe diseases.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

    A Retrospective Look at the Sarbanes-Oxley Act of 2002- Has it accomplished its original purpose?

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    As a result of notable frauds including Enron, WorldCom and Waste Management, the United States Congress enacted the Sarbanes-Oxley Act of 2002 (SOX).  The Act would forever change the accounting profession.  After a little more than a decade, publicly traded companies have been able to create and implement policies and procedures to ensure compliance with the Act, specifically the provisions set forth in Section 404.  Since all public companies have implemented SOX compliance together with other regulations imposed by the Internal Revenue Service and other regulatory agencies into their normal reporting routines, management of these companies have realized further benefits associated with SOX compliance.  Because of these reported benefits many private companies have begun to voluntarily implement SOX-like policies and procedures into their own internal framework.  This paper will discuss the perceptions of the enactment and implementation of the Act, the associated benefits derived from SOX compliance and reasons why private companies have begun voluntarily adopting SOX-like policiesprocedures and strategies

    Thermal conductivity in harmonic lattices with random collisions

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    We review recent rigorous mathematical results about the macroscopic behaviour of harmonic chains with the dynamics perturbed by a random exchange of velocities between nearest neighbor particles. The random exchange models the effects of nonlinearities of anharmonic chains and the resulting dynamics have similar macroscopic behaviour. In particular there is a superdiffusion of energy for unpinned acoustic chains. The corresponding evolution of the temperature profile is governed by a fractional heat equation. In non-acoustic chains we have normal diffusivity, even if momentum is conserved.Comment: Review paper, to appear in the Springer Lecture Notes in Physics volume "Thermal transport in low dimensions: from statistical physics to nanoscale heat transfer" (S. Lepri ed.

    Smell and taste disorders

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    Smell and taste disorders can markedly affect the quality of life. In recent years we have become much better in the assessment of the ability to smell and taste. In addition, information is now available to say something about the prognosis of individual patients. With regard to therapy there also seems to be low but steady progress. Of special importance for the treatment is the ability of the olfactory epithelium to regenerate
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