purpose: to investigate the effects of surface ablation excimer surgery on higher-order aberrations and to assess the safety and efficacy of wavefront-guided surface ablation excimer surgery in patients with hyperopia and hyperopic astigmatism. methods: in this analytical & descriptive study, wavefront-guided surface ablation excimer surgery was performed in 58 eyes of 31 patients with hyperopi...

Context. It has been suggested that resonant phenomena may play a role in determining the properties of mean-field dynamos, such as operate in the Sun and other stars. Aims. We tried to identify resonances which are expected to occur when a mean-field dynamo excites waves of quasi-stationary magnetic field in two distinct spherical layers. Methods. We used a model with two physically separated ...

PET imagery is a valuable oncology tool for characterizing lesions and assessing lesion response to therapy. These assessments require accurate delineation of the lesion. This is a challenging task for clinicians due to small tumor sizes, blurred boundaries from the large point-spread-function and respiratory motion, inhomogeneous uptake, and nearby high uptake regions. These aspects have led t...

Author(s) of this paper may load this reprint on their own web site provided that this cover page is retained. Republication of this article or its storage in electronic databases or the like is not permitted without prior permission in writing from the IUCr. A numerically efficient method of constructing symmetric real spherical harmonics is presented. Symmetric spherical harmonics are real sp...

This paper reports a new procedure for specifying monochromatic nonradiating ~NR! current distributions ~NR sources! and the electric and magnetic fields they produce ~NR fields!. Vector spherical harmonics and a Fourier–Bessel series are used to derive a new vector spherical-wave expansion for continuous NR fields confined within a spherical volume. The analysis yields complete orthogonal sets...

The data saturation problem in Landsat imagery is well recognized and is regarded as an important factor resulting in inaccurate forest aboveground biomass (AGB) estimation. However, no study has examined the saturation values for different vegetation types such as coniferous and broadleaf forests. The objective of this study is to estimate the saturation values in Landsat imagery for different...