background paranasal sinus ct has high sensitivity and specificity for sinusitis. however, this modality is costly and involves greater radiation exposure than plain radiographs. objectives we tried to compare 10-cut limited ct scan and standard ct scan in the diagnosis of sinusitis. materials and methods we conducted a cross sectional case series from august to december 2010 on 150 patients wi...

Spiral waves have been observed in several chemical systems, for instance, in the Belousov-Zhabotinsky reaction and in the catalysis on platinum surfaces. Seemingly key to the dynamics of spiral waves is the Euclidean symmetry group SE(N). In this article, an SE(N)-equivariant center-manifold reduction near meandering spirals and other waves is developed. The vector eld on the center manifold h...

The statistics of nested spiral self–avoiding loops, which is closely related to the partition of integers into decreasing parts, has been studied on the square and triangular lattices. The number of configurations with N steps is cN ≃ ( √ 2/24)N−3/2 exp(π √ 2 3 N1/2) and their average sizeXN ≃ (1/2π) √ 3 2 N1/2 lnN to leading order on the square lattice while the corresponding values for the t...

We present a new procedure to fit non-axisymmetric flow patterns to 2-D velocity maps of spiral galaxies. We concentrate on flows caused by bar-like or oval distortions to the total potential that may arise either from a non-axially symmetric halo or a bar in the luminous disk. We apply our method to high-quality CO and Hα data for the nearby, low-mass spiral NGC 2976 previously obtained by Sim...

conclusions there was no statistically significant difference in the parotid absorbed dose between spiral tomography and a panoramic radiograph (p value = 0.18). the overall results of this study were similar to other studies. results for the tube side parotid, the average absorbed doses in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice th...

An ensemble of symmetric potential energy wells arranged at the vertices of a Fibonacci spiral can serve as the basis for an irreducibly two-dimensional thermal ratchet. Periodic rotation of the potential energy landscape through a three-step cycle drives trapped Brownian particles along spiral trajectories through the pattern. Which spiral is selected depends on the angular displacement at eac...

Gradient-based edge detection is a straightforward method to identify the edge points in the original grey-level image. It is intuitive that in the human vision system the edge points always appear where the grey-level value is greatly changed. Spiral Architecture is a relatively new image data structure that is inspired from anatomical considerations of the primate's vision. In Spiral Architcc...

Abstract Finding the ground state of complex many-body systems, such as magnetic materials containing topological textures, like skyrmions, is a fundamental and long-standing problem. We present here genetic-tunneling-driven variance-controlled optimization method, that efficiently identifies two-dimensional skyrmionic systems. The approach combines local energy-minimizer backend metaheuristic ...