In transversely isotropic media with a vertical axis of symmetry (VTI media), we can represent the image in vertical time, as opposed to depth, thus eliminating the inherent ambiguity of resolving the vertical P-wave velocity from surface seismic data. In this new (x − τ )-domain, the raytracing and eikonal equations are completely independent of the vertical P-wave velocity, on the condition t...

BACKGROUND The role of antiretroviral therapy in acceleration of atherosclerosis in patients with human immunodeficiency virus (HIV) infection is controversial. We hypothesized that aortic stiffness, an early marker of arteriosclerosis, may be increased in HIV patients treated with protease inhibitors. METHODS AND RESULTS In 32 HIV-infected patients treated with protease inhibitors and 32 age...

Crustal velocity structure of the Chingshui-Tuchang area is obtained from the analysis of Pand S-wave arrivals of 257 local earthquakes recorded by a temporary seismic network in Ilan, northeastern Taiwan. The results of one-dimensional structure show that a major discontinuity in the uppercrust is found at the depth of 3 km for both Pand S-wave velocities. In addition, a significantly low S-wa...

We have studied the formation of relativistic solitary waves due to nonlinearinteraction of strong electromagnetic wave with the plasma wave. Here, our plasma isrelativistic both in temperature and in streaming speed. A set of equations consisting ofscalar and vector potentials together with a third order equation for the enthalpy inphoton gas plasma is obtained analytic...

BACKGROUND To determine sensitivity and specificity of E wave velocity in patients with severe chronic organic mitral regurgitation (MR) and normal left ventricular ejection fraction (EF) and to evaluate prevalence of A wave dominance in patients with severe MR. METHODS We compared 35 patients with quantified severe, chronic, quantified, organic MR due to flail/prolapsed leaflets who had repa...

The central arteries stiffen with age, causing hemodynamic alterations that have been associated with cardiovascular events. Changes in body fat with age may be related to aortic stiffening. The association between vascular stiffness and body fat was evaluated in 2488 older adults (mean age, 74 years; 52% female; 40% black) enrolled in the Study of Health, Aging, and Body Composition (Health AB...

We examined whether the presence of an increasing number of metabolic syndrome "disorders" was associated with an increasing pulse wave velocity, which is recognized as a marker of cardiovascular risk, and evaluated whether an elevated plasma C-reactive protein level augments this increasing pulse wave velocity. Using a cross-sectional study design, C-reactive protein, metabolic syndrome-relate...

I present a finite-difference method for modeling P-SV wave propagation in heterogeneous media. This is an extension of the method I previously proposed for modeling SH-wave propagation by using velocity and stress in a discrete grid. The two components of the velocity cannot be defined at the same node for a complete staggered grid: the stability condition and the P-wave phase velocity dispers...

Circulating C-reactive protein (CRP) level is associated with cardiovascular disease. Whether this relationship is causal has been subject of debate, especially as a potential therapeutic target. Previous studies have demonstrated an association between circulating CRP levels and arterial pulse wave velocity, an accepted measure of arterial stiffness. We investigated the association between cir...

INTRODUCTION AND AIM Right ventricular function is a major determinant of prognosis in pulmonary hypertension. The aim of this study was to assess and compare right ventricular contractile reserve in healthy subjects (controls) and in subjects with pulmonary hypertension (cases). METHODS In this prospective study of seven cases and seven controls undergoing treadmill stress echocardiography, ...