We evaluated whether group locomotor imagery training-combined knowledge of performance (KP) lead to improvements in gait function in community dwelling individuals with chronic stroke. Ten adults who had suffered a hemiparetic stroke at least 6 months earlier participated in group locomotor imagery training-combined KP for 5 weeks, twice per week, with 2 h intensive training. Dynamic gait index scores increased significantly after the group locomotor imagery training-combined KP. However, times for the timed up-and-go test did not improve significantly after the training. Group locomotor imagery training-combined KP may be a useful option for the relearning of gait performance for community dwelling individuals with chronic hemiparetic stroke.

The objective of this study was to evaluate the effects of mirror therapy on motor function recovery following a stroke through a systemic review and meta-analysis. In total, nine of the 48 studies were identified from search engines between 1997 and 2011, as well as from a review of the reference lists of each identified study. The quality of each study was assessed using Jadad scale, and the effect size was calculated as a Cohen's effect size using MetaAnalyst (Beta 3.13). The overall effect size of the mirror therapy was 2.005 (95% confidence interval=1.041~2.970) in a random-effects model. This finding suggests that mirror therapy is beneficial for improving motor function following a stroke. The results from the subgroup analysis according to categorical variables were as follows: First, the effect size was larger for an onset time of less than 1 year (1.166) than for a duration of 1 year or more (.668). Second, the effect size of unpublished dissertations (1.610) was larger than published articles (1.221). Third, motor recovery of upper extremities (1.609) had a greater effect than motor recovery of lower extremities (.903). The major limitation of this study is the relatively small study population. Therefore, further individual studies of mirror therapy should be conducted in order to generalize the effects. In addition, mirror therapy supervised by a physical therapist should be recognized as a potential approach to manage motor function following a stroke and recommended to patients to improve their motor function.

A small number of active galactic nuclei are known to exhibit prominent double peak emission profiles that are well-fitted by a relativistic accretion disk model. We develop a Monte Carlo code to compute the linear polarization of a double peaked broad emission line arising from Thomson scattering. A Keplerian accretion disk is adopted for the double peak emission line region and the geometry is assumed to be Schwarzschild. Far from the accretion disk where flat Minkowski geometry is appropriate, we place an azimuthally symmetric scattering region in the shape of a spherical shell sliced with Δμ =0.1. Adopting a Monte Carlo method we generate line photons in the accretion disk in arbitrary directions in the local rest frame and follow the geodesic paths of the photons until they hit the scattering region. The profile of the polarized flux is mainly determined by the relative location of the scattering region with respect to the emission source. When the scattering region is in the polar direction, the degree of linear polarization also shows a double peak structure. Under favorable conditions we show that up to 0.6% linear polarization may be obtained. We conclude that spectropolarimetry can be a powerful probe to reveal much information regarding the accretion disk geometry of these active galactic nuclei.

Ever since the identification of 6830 and 7088 features as the Raman scattered O VI 1032, 1038 resonance doublets in symbiotic stars by Schmid (1989), Raman scattering by atomic hydrogen has been a very unique tool to investigate the mass transfer processes in symbiotic stars. Discovery of Raman scattered He II in young planetary nebulae (NGC 7027, NGC 6302, IC 5117) allow one to expect that Raman scattering can be an extremely useful tool to look into the mass loss processes in these objects. Because hydrogen is a single electron atom, their wavefunctions are known in closed form, so that exact calculations of cross sections are feasible. In this paper, I review some basic properties of Raman scattered features and present detailed and explicit matrix elements for computation of the scattering cross section of radiation with atomic hydrogen. Some astrophysical objects for which Raman scattering may be observationally pertinent are briefly mentioned.

In Lee, Kang & Byun (2001) the discovery of Raman scattered 6545 A feature was reported in symbiotic stars and the planetary nebula M2-9. The broad emission feature around 6545 A is formed as a result of Raman scattering of He II n = 6 → n = 2 photons by atomic hydrogen. In this paper, we introduce a method to compute the equivalent width of He II ⋋ 1025 line and present an optical spectrum of the symbiotic star RR Telescopii as an example for a detailed illustration. In this spectrum, we pay attention to the broad Hα wings and the Raman scattered He II 6545 feature. The broad Ha wings are also proposed to be formed through Raman scattering of continuum around Lyβ by Lee (2000), and therefore we propose that the equivalent width of the He II ⋋ 1025 emission line is obtained by a simple comparison of the strengths of the 6545 feature and the broad Hα wings. We prepare a template Hα wing profile from continuum radiation around Lyβ with the neutral scattering region that is supposed to be responsible for the formation of Raman scattered He II 6545 feature. Isolation of the 6545 feature that is blended with [N II] ⋋ 6548 is made by using the fact that [N II] ⋋ 6584 is always 3 times stronger than [N II] ⋋ 6548. We also fit the 6545 feature by a Gaussian which has a width 6.4 times that of the He II ⋋ 6527 line. A direct comparison of these two features for RR Tel yields the equivalent width EW Hel025 = 2.3 Å of He II ⋋ 1025 line. Even though this far UV emission line is not directly observable due to heavy interstellar extinction, nearby He II lines such as He II ⋋ 1085 line may be observed using far UV space instruments, which will verify this calculation and hence the origins of various features occurring in spectra around Hα.