302 research outputs found
Granular Cell Myoblastoma of the Larynx
Granuloma cell myoblastoma ofthe larynx is a relatively uncommon tumor. A review of the literature reveals only 52 cases reported. The lesion is a benign growth which is often asymptomatic, though most commonly associated with hoarseness. The treatment of choice is local surgical excision. Four successfully treated cases are reported. All four patients are Negro â three females and one male
Re: "Comparison of antipseudomonal betalactams for febrile neutropenia empiric therapy: systematic review and network metaanalysis" by Horita et al
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Universality of low-energy scattering in (2+1) dimensions
We prove that, in (2+1) dimensions, the S-wave phase shift, , k
being the c.m. momentum, vanishes as either as . The constant is universal and .
This result is established first in the framework of the Schr\"odinger equation
for a large class of potentials, second for a massive field theory from proved
analyticity and unitarity, and, finally, we look at perturbation theory in
and study its relation to our non-perturbative result. The
remarkable fact here is that in n-th order the perturbative amplitude diverges
like as , while the full amplitude vanishes as . We show how these two facts can be reconciled.Comment: 23 pages, Late
Asymptotic Fourier Coefficients for a C â Bell (Smoothed-âTop-Hatâ) & the Fourier Extension Problem
In constructing local Fourier bases and in solving differential equations with nonperiodic solutions through Fourier spectral algorithms, it is necessary to solve the Fourier Extension Problem. This is the task of extending a nonperiodic function, defined on an interval , to a function which is periodic on the larger interval . We derive the asymptotic Fourier coefficients for an infinitely differentiable function which is one on an interval , identically zero for , and varies smoothly in between. Such smoothed âtop-hatâ functions are âbellsâ in wavelet theory. Our bell is (for x â„ 0) where where . By applying steepest descents to approximate the coefficient integrals in the limit of large degree j , we show that when the width L is fixed, the Fourier cosine coefficients a j of on are proportional to where Î( j ) is an oscillatory factor of degree given in the text. We also show that to minimize error in a Fourier series truncated after the N th term, the width should be chosen to increase with N as . We derive similar asymptotics for the function f ( x )= x as extended by a more sophisticated scheme with overlapping bells; this gives an even faster rate of Fourier convergencePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43417/1/10915_2005_Article_9010.pd
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