112 research outputs found
BIOMECHANICAL FEATURES OF STRIKING MOVEMENTS ON JAPANESE DRUM
The purpose of this study is to clarify the biomechanical features of the human striking movements observed while playing the Japanese drum by three dimensional analysis. Three subjects participated in this study in order to deterimine the motion of a professional player, an experienced player and a novice player. Digital videography method was applied to each subject, regarding their maximum effort during a 15-second exercise, and measured EMG and GRF. The results showed that the biomechanical features of striking movements are to make the most of ability with the features of Taiko, through repetition of efficient strike and recovery. Moreover, the crucial point was expressed at a strike velocity of 4.42m/s and at a recovery velocity of 3.76m/s. In addition, the feature of Yoko-uchi by a professional player is a single leg striking method
X-Ray Study of Temperature and Abundance Profiles of the Cluster of Galaxies Abell 1060 with Suzaku
We carried out observations of the central and 20' east offset regions of the
cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral
analysis has revealed temperature and abundance profiles of Abell 1060 out to
27' ~ 380; /h_70 kpc, which corresponded to ~ 0.25; r_180. Temperature decrease
of the intra cluster medium from 3.4 keV at the center to 2.2 keV in the
outskirt region are clearly observed. Abundances of Si, S and Fe also decrease
by more than 50% from the center to the outer, while Mg shows fairly constant
abundance distribution at ~ 0.7 solar within r < 17'. O shows lower abundance
of ~ 0.3 solar in the central region (r~ 6'), and indicates a similar feature
with Mg, however it is sensitive to the estimated contribution of the Galactic
components of kT_1 ~ 0.15 keV and kT_2 ~ 0.7 keV in the outer annuli (r ~ 13').
Systematic effects due to the point spread function tails, contamination on the
XIS filters, instrumental background, cosmic and/or Galactic X-ray background,
and the assumed solar abundance tables are carefully examined. Results on
temperature and abundances of Si, S, and Fe are consistent with those derived
by XMM-Newton at r < 13'. Formation and metal enrichment process of the cluster
are discussed based on the present results.Comment: 20 pages, 19 figures, accepted for publication in PAS
Novel function of HATs and HDACs in homologous recombination through acetylation of human RAD52 at double-strand break sites
The p300 and CBP histone acetyltransferases are recruited to DNA double-strand break (DSB) sites where they induce histone acetylation, thereby influencing the chromatin structure and DNA repair process. Whether p300/CBP at DSB sites also acetylate non-histone proteins, and how their acetylation affects DSB repair, remain unknown. Here we show that p300/CBP acetylate RAD52, a human homologous recombination (HR) DNA repair protein, at DSB sites. Using in vitro acetylated RAD52, we identified 13 potential acetylation sites in RAD52 by a mass spectrometry analysis. An immunofluorescence microscopy analysis revealed that RAD52 acetylation at DSBs sites is counteracted by SIRT2- and SIRT3-mediated deacetylation, and that non-acetylated RAD52 initially accumulates at DSB sites, but dissociates prematurely from them. In the absence of RAD52 acetylation, RAD51, which plays a central role in HR, also dissociates prematurely from DSB sites, and hence HR is impaired. Furthermore, inhibition of ataxia telangiectasia mutated (ATM) protein by siRNA or inhibitor treatment demonstrated that the acetylation of RAD52 at DSB sites is dependent on the ATM protein kinase activity, through the formation of RAD52, p300/CBP, SIRT2, and SIRT3 foci at DSB sites. Our findings clarify the importance of RAD52 acetylation in HR and its underlying mechanism
In Orbit Timing Calibration of the Hard X-Ray Detector on Board Suzaku
The hard X-ray detector (HXD) on board the X-ray satellite Suzaku is designed
to have a good timing capability with a 61 s time resolution. In addition
to detailed descriptions of the HXD timing system, results of in-orbit timing
calibration and performance of the HXD are summarized. The relative accuracy of
time measurements of the HXD event was confirmed to have an accuracy of
s s per day, and the absolute timing was confirmed
to be accurate to 360 s or better. The results were achieved mainly
through observations of the Crab pulsar, including simultaneous ones with RXTE,
INTEGRAL, and Swift.Comment: Accepted for publication on PASJ Vol.60, SP-1, 200
The ASTRO-H X-ray Observatory
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly
successful X-ray missions initiated by the Institute of Space and Astronautical
Science (ISAS). ASTRO-H will investigate the physics of the high-energy
universe via a suite of four instruments, covering a very wide energy range,
from 0.3 keV to 600 keV. These instruments include a high-resolution,
high-throughput spectrometer sensitive over 0.3-2 keV with high spectral
resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in
the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers
covering 5-80 keV, located in the focal plane of multilayer-coated, focusing
hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12
keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and
a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the
40-600 keV band. The simultaneous broad bandpass, coupled with high spectral
resolution, will enable the pursuit of a wide variety of important science
themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical
Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to
Gamma Ray
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Clusters of galaxies are the most massive gravitationally-bound objects in
the Universe and are still forming. They are thus important probes of
cosmological parameters and a host of astrophysical processes. Knowledge of the
dynamics of the pervasive hot gas, which dominates in mass over stars in a
cluster, is a crucial missing ingredient. It can enable new insights into
mechanical energy injection by the central supermassive black hole and the use
of hydrostatic equilibrium for the determination of cluster masses. X-rays from
the core of the Perseus cluster are emitted by the 50 million K diffuse hot
plasma filling its gravitational potential well. The Active Galactic Nucleus of
the central galaxy NGC1275 is pumping jetted energy into the surrounding
intracluster medium, creating buoyant bubbles filled with relativistic plasma.
These likely induce motions in the intracluster medium and heat the inner gas
preventing runaway radiative cooling; a process known as Active Galactic
Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus
cluster core, which reveal a remarkably quiescent atmosphere where the gas has
a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from
the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s
is found across the 60 kpc image of the cluster core. Turbulent pressure
support in the gas is 4% or less of the thermodynamic pressure, with large
scale shear at most doubling that estimate. We infer that total cluster masses
determined from hydrostatic equilibrium in the central regions need little
correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
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