5,149 research outputs found
Seasonality of Deaths in the U.S. by Age and Cause
In this paper, we analyze seasonality of deaths by age and cause in the U.S. using public use files for the years 1994 to 1998 by the methods of regression and a variation of Census Method II. We answer the following questions: For each age cohort, how much does each cause of death contribute to seasonality of deaths? What is the reason for the variation in seasonality of deaths with respect to age? We also analyze death records of Social Security Administration over a longer time period to examine how seasonality of deaths has changed since the mid-1970’s. We found that in general, the degree of seasonality in deaths has decreased over time for younger cohorts and has increased over time for older cohorts.mortality, seasonality
Cosmologies with Two-Dimensional Inhomogeneity
We present a new generating algorithm to construct exact non static solutions
of the Einstein field equations with two-dimensional inhomogeneity. Infinite
dimensional families of inhomogeneous solutions with a self interacting
scalar field, or alternatively with perfect fluid, can be constructed using
this algorithm. Some families of solutions and the applications of the
algorithm are discussed.Comment: 9 pages, one postscript figur
Scalar Field Inhomogeneous Cosmologies
Some exact solutions for the Einstein field equations corresponding to
inhomogeneous cosmologies with an exponential-potential scalar field
which generalize solutions obtained previously are considered. Several
particular cases are studied and the properties related to generalized
inflation and asymptotic behaviour of the models are discussed.Comment: 21 pages LaTeX, 3 figures appended as a uuencoded compressed tar fil
Can the Type-IIB axion prevent Pre-big Bang inflation?
We look at the possibility of superinflationary behavior in a class of
anisotropic Type-IIB superstring cosmologies in the context of Pre-big Bang
scenario and find that there exists a rather narrow range of parameters for
which these models inflate. We then show that, although in general this
behavior is left untouched by the introduction of a Ramond-Ramond axion field
through a SL(2,R) rotation, there exists a particular class of axions for which
inflation disappears completely. Asymptotic past initial conditions are briefly
discussed, and some speculations on the possible extension of Pre-big Bang
ideas to gravitational collapse are presented.Comment: harvmac, epsf. 3 figures include
Aortic Coarctation: Recent Developments in Experimental and Computational Methods to Assess Treatments for this Simple Condition
Coarctation of the aorta (CoA) is often considered a relatively simple disease, but long-term outcomes suggest otherwise as life expectancies are decades less than in the average population and substantial morbidity often exists. What follows is an expanded version of collective work conducted by the authors\u27 and numerous collaborators that was presented at the 1st International Conference on Computational Simulation in Congenital Heart Disease pertaining to recent advances for CoA. The work begins by focusing on what is known about blood flow, pressure and indices of wall shear stress (WSS) in patients with normal vascular anatomy from both clinical imaging and the use of computational fluid dynamics (CFD) techniques. Hemodynamic alterations observed in CFD studies from untreated CoA patients and those undergoing surgical or interventional treatment are subsequently discussed. The impact of surgical approach, stent design and valve morphology are also presented for these patient populations. Finally, recent work from a representative experimental animal model of CoA that may offer insight into proposed mechanisms of long-term morbidity in CoA is presented
Generating Black Strings in Higher Dimensions
Starting with a Zipoy-Voorhees line element we construct and study the three
parameter family of solutions describing a deformed black string with arbitrary
tension.Comment: 11 pages, 2 figures, accepted for publication in J. Mod. Phys. Lett.
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