In view of the observed flat rotation curves spiral galaxies and motivated by simple fact that within newtonian gravity a stationary axisymmetric mass distribution or dark matter vortex finite extent readily displays somewhat flattened out velocity curve up to distances comparable such transverse galaxy's disk, possibility flattening may rather be manifestation some space-time curvature purely ...

A retrospective study. To summarize and describe the radiographic parameters of adult degenerative scoliosis (ADS) and explore the radiological parameters which are significantly different in sagittal balanced and imbalanced ADS patients. ADS is the most common type of adult spinal deformity. However, no comprehensive description of radiographic parameters in ADS patients has been made, and few...

Monte Carlo simulations of complex rotation of single −CH3 groups, −(CH3)3 groups and −BH3 groups were performed for trimethylamine borane (CH3)3NBH3. In the course of these simulations the correlation functions for different models of rotation were determined. Knowledge of these functions and of some data extracted from NMR experiments allowed for the calculation of the longitudinal magnetic r...

For a Jordan domain with smooth boundary, the boundary rotation h is defined as the total variation of the direction angle of the tangent to the boundary curve under a complete circuit. The domain is said to have bounded turning or rotation if h < 1 and the functions under such mappings are called functions of bounded boundary turning or rotation. We define a generalization of this concept and ...

For an area-preserving twist map F of a finite annulus, we obtain “quasi-foliations” of the annulus by one-sided-F -invariant graphs of functions that are either continuous (in which case the graph is a fully invariant curve) or have countably many jump discontinuities. For each of the one-sided-invariant graphs there is a well defined (one-sided) rotation number and all the numbers between the...

A rotation matrix can be generated by a unit timelike quaternion in the three dimensional Minkowski space. In this paper, we correspond columns of this rotation matrix to Frenet vectors of a nonlightlike curve and we find a reformulation of Frenet’s formulas of nonlightlike curves in terms of the timelike quaternions in the Minkowski 3-space. Moreover, we do same things for the parallel transpo...

We study gravitational lensing by spiral galaxies, using realistic models consisting of halo, disk, and bulge components combined to produce a flat rotation curve. Proper dynamical normalization of the models is critical because a disk requires less mass than a spherical halo to produce the same rotation curve—a face-on Mestel disk has a lensing cross section only 41% as large as a singular iso...

We present new Hi (20′′ resolution) and CO observations of NGC 4548, an anemic galaxy in the Virgo cluster. The atomic gas distribution shows a ring structure which is distorted at the northern edge. The overall rotation curve is derived with a tilted ring model. We compare our rotation curve with previous ones and discuss the differences. The velocity field of the CO pointings fits very well w...