Background: Mobilization and cranio-cervical flexion exercise has been reported in reducing pain from cervical part and improving its motor function; also, has been represented that alleviate of neck pain and recover of neck muscles improve the normal gait performance. However, few studies have identified the effects of mobilization and exercise on pain and gait parameters with preceding issues. Objective: To examine the effects or changes of pressure pain threshold (PPT) and gait parameters in patients with chronic neck pain. Design: Cross-Sectional Clinical Trials Methods: Twenty patients with the history of neck pain (>3 months) performed the cervical mobilization and cranio-cervical flexion exercise. Gait parameters were assessed with wireless device and collected data were transmitted to the personal computer via Bluetooth. The PPT was measured posteroanterior direction at the prone position and the mean of subsequent three PPT measurements was used for the final analysis. Results: Both cervical central posteroanterior mobilization (CCPAM) (p<.000) and sling-based cranio-cervical flexion exercise (SBCCFE) (p<.000) group showed a significant increase in the PPT and the gait parameters, cadence (p<.023), was significantly increased in the CCPAM group, however slightly increased in the SBCCFE group. The comparison between the CCPAM and the SBCCFE groups after treatment did not show significant differences for the score on the PPT and gait parameters. Conclusions: This study suggests that CCPAM and SBCCFE increase PPT, cadence, and gait speed.

Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a “anti-correlated” mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ∼1.6% to ∼7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.

Intensity interferometry, based on the Hanbury Brown–Twiss effect, is a simple and inexpensive method for optical interferometry at microarcsecond angular resolutions; its use in astronomy was abandoned in the 1970s because of low sensitivity. Motivated by recent technical developments, we argue that the sensitivity of large modern intensity interferometers can be improved by factors up to approximately 25 000, corresponding to 11 photometric magnitudes, compared to the pioneering Narrabri Stellar Interferometer. This is made possible by (i) using avalanche photodiodes (APD) as light detectors, (ii) distributing the light received from the source over multiple independent spectral channels, and (iii) use of arrays composed of multiple large light collectors. Our approach permits the construction of large (with baselines ranging from few kilometers to intercontinental distances) optical interferometers at the cost of (very) long-baseline radio interferometers. Realistic intensity interferometer designs are able to achieve limiting R-band magnitudes as good as mR ≈ 14, sufficient for spatially resolved observations of main-sequence O-type stars in the Magellanic Clouds. Multi-channel intensity interferometers can address a wide variety of science cases: (i) linear radii, effective temperatures, and luminosities of stars, via direct measurements of stellar angular sizes; (ii) mass–radius relationships of compact stellar remnants, via direct measurements of the angular sizes of white dwarfs; (iii) stellar rotation, via observations of rotation flattening and surface gravity darkening; (iv) stellar convection and the interaction of stellar photospheres and magnetic fields, via observations of dark and bright starspots; (v) the structure and evolution of multiple stars, via mapping of the companion stars and of accretion flows in interacting binaries; (vi) direct measurements of interstellar distances, derived from angular diameters of stars or via the interferometric Baade–Wesselink method; (vii) the physics of gas accretion onto supermassive black holes, via resolved observations of the central engines of luminous active galactic nuclei; and (viii) calibration of amplitude interferometers by providing a sample of calibrator stars.