43 research outputs found
Suzaku observations of subhalos in the Coma cluster
We observed three massive subhalos in the Coma cluster with {\it Suzaku}.
These subhalos, labeled "ID 1", "ID 2", and "ID 32", were detected with a
weak-lensing survey using the Subaru/Suprime-Cam (Okabe et al. 2014a), and are
located at the projected distances of 1.4 , 1.2 , and 1.6
from the center of the Coma cluster, respectively. The subhalo "ID 1"
has a compact X-ray excess emission close to the center of the weak-lensing
mass contour, and the gas mass to weak-lensing mass ratio is about 0.001. The
temperature of the emission is about 3 keV, which is slightly lower than that
of the surrounding intracluster medium (ICM) and that expected for the
temperature vs. mass relation of clusters of galaxies. The subhalo "ID 32"
shows an excess emission whose peak is shifted toward the opposite direction
from the center of the Coma cluster. The gas mass to weak-lensing mass ratio is
also about 0.001, which is significantly smaller than regular galaxy groups.
The temperature of the excess is about 0.5 keV and significantly lower than
that of the surrounding ICM and far from the temperature vs. mass relation of
clusters. However, there is no significant excess X-ray emission in the "ID 2"
subhalo. Assuming an infall velocity of about 2000 , at the
border of the excess X-ray emission, the ram pressures for "ID 1" and "ID 32"
are comparable to the gravitational restoring force per area. We also studied
the effect of the Kelvin-Helmholtz instability to strip the gas. Although we
found X-ray clumps associated with the weak-lensing subhalos, their X-ray
luminosities are much lower than the total ICM luminosity in the cluster
outskirts.Comment: 19 pages, 8 figures, ApJ in pres
Suzaku observations of the Hydra A cluster out to the virial radius
We report Suzaku observations of the northern half of the Hydra A cluster out
to ~1.4 Mpc, reaching the virial radius. This is the first Suzaku observations
of a medium-size (kT ~3 keV) cluster out to the virial radius. Two observations
were conducted, north-west and north-east offsets, which continue in a filament
direction and a void direction of the large-scale structure of the Universe,
respectively. The X-ray emission and distribution of galaxies elongate in the
filament direction. The temperature profiles in the two directions are mostly
consistent with each other within the error bars and drop to 1.5 keV at 1.5
r_500. As observed by Suzaku in hot clusters, the entropy profile becomes
flatter beyond r_500, in disagreement with the r^1.1 relationship that is
expected from accretion shock heating models. When scaled with the average
intracluster medium (ICM) temperature, the entropy profiles of clusters
observed with Suzaku are universal and do not depend on system mass. The
hydrostatic mass values in the void and filament directions are in good
agreement, and the Navarro, Frenk, and White universal mass profile represents
the hydrostatic mass distribution up to ~ 2 r_500. Beyond r_500, the ratio of
gas mass to hydrostatic mass exceeds the result of the Wilkinson microwave
anisotropy probe, and at r_100, these ratios in the filament and void
directions reach 0.4 and 0.3, respectively. We discuss possible deviations from
hydrostatic equilibrium at cluster outskirts. We derived radial profiles of the
gasmass- to-light ratio and iron-mass-to-light ratio out to the virial radius.
Within r_500, the iron-mass-to-light ratio of the Hydra A cluster was compared
with those in other clusters observed with Suzaku.Comment: 16 pages, 15 figures; Accepted for publication in PAS
Suzaku Observation of Abell 1689: Anisotropic Temperature and Entropy Distributions Associated with the Large-Scale Structure
(Abridged) We present results of Suzaku observations of the intracluster
medium (ICM) in Abell 1689, combined with complementary analysis of the SDSS
data and weak and strong lensing analysis of Subaru/Suprime-Cam and HST/ACS
observations. Faint X-ray emission from the ICM around the virial radius is
detected at 4.0 sigma significance. We find anisotropic gas temperature and
entropy distributions in cluster outskirts correlated with large-scale
structure of galaxies. The high temperature and entropy region in the
northeastern (NE) outskirts is connected to an overdense filamentary structure.
The outskirt regions in contact with low density void environments have low gas
temperatures and entropies, deviating from hydrostatic equilibrium. These
results suggest that thermalization of the ICM occurs faster along the
filamentary structures than the void regions. A joint X-ray and lensing
analysis shows that the hydrostatic mass is of spherical lensing
one but comparable to a triaxial halo mass within errors in 0.6r_{2500} \simlt
r \simlt 0.8r_{500}, and that it is significantly biased as low as \simlt60%
within , irrespective of mass models. The thermal gas pressure
within is, at most, --60% of the total pressure to balance
fully the gravity of the spherical lensing mass, and --40% around the
virial radius. Although these constitute lower limits when one considers the
possible halo triaxiality, these small relative contributions of thermal
pressure would require additional sources of pressure, such as bulk and/or
turbulent motions.Comment: 24 pages, 15 figures, 9 tables. Accepted for publication in Ap
Genetic and Epigenetic Alterations of Lysophosphatidic Acid Receptor Genes in Rodent Tumors by Experimental Models
Lysophosphatidic acid (LPA) is a bioactive mediator and induces several
biological effects, including cell proliferation, migration, morphogenesis and
differentiation. LPA interacts with at least six G protein-coupled receptors
(GPCRs), including LPA receptor-1 (LPA1), LPA2,
LPA3, LPA4, LPA5 and LPA6. These
receptors show different biological functions through the binding of LPA,
depending on the type of cells. In human malignancies, a high level of LPA
production was found in plasma and ascites in ovarian cancer cases. Moreover,
aberrant expression levels of LPA receptor genes were detected in some cancer
cells. Therefore, it is suggested that LPA receptors may be involved in the
pathogenesis of tumor cells as well as LPA per se. Recently, we have reported
that alterations of LPA receptor genes also occur in rodent tumors. In this
review, we summarize the recent evidence in the investigations of LPA receptor
alterations in rodent tumors by experimental models
The crucial role of the TRPM7 kinase domain in the early stage of amelogenesis.
Transient receptor potential melastatin-7 (TRPM7) is a bi-functional protein containing a kinase domain fused to an ion channel. TRPM7 is highly expressed in ameloblasts during tooth development. Here we show that TRPM7 kinase-inactive knock-in mutant mice (TRPM7 KR mice) exhibited small enamel volume with opaque white-colored incisors. The TRPM7 channel function of ameloblast-lineage cells from TRPM7 KR mice was normal. Interestingly, phosphorylation of intracellular molecules including Smad1/5/9, p38 and cAMP response element binding protein (CREB) was inhibited in ameloblasts from TRPM7 KR mice at the pre-secretory stage. An immunoprecipitation assay showed that CREB was bound to TRPM7, suggesting that direct phosphorylation of CREB by TRPM7 was inhibited in ameloblast-lineage cells from TRPM7 KR mice. These results indicate that the function of the TRPM7 kinase domain plays an important role in ameloblast differentiation, independent of TRPM7 channel activity, via phosphorylation of CREB.福岡歯科大学2017年
No association of the Trp 64 Arg mutation of the β3-adrenergic receptor gene with obesity, type 2 diabetes mellitus, hyperlipidemia, and hypertension in Japanese patients with schizophrenia
This study was conducted to address the question of whether the β3-adrenergic receptor gene mutation (Trp 64 Arg) is associated with metabolic disease in Japanese patients with schizophrenia. Methods : In a cross-sectional study, 89 participants were grouped into three genotypes. The 64 Arg allelic frequency in patients with or without metabolic disease was analyzed. Anthropometrics variables and biochemical parameters were compared among the genotypes. Results : The 64 Arg allele, which had a frequency of 0.22, was not associated with obesity, type 2 diabetes mellitus, dyslipidemias, or hypertension. No significant differences among the genotypes were found in current age, age at diagnosis with schizophrenia, body mass index, waist-hip ratio, plasma glucose, plasma insulin, triglycerides, free fatty acids. Patients with the 64 Arg allele had greater 24-h excretion of norepinephrine than those lacking the variant (p=0.019). Conclusion : The 64Arg allelic mutation is not associated with obesity, type 2 diabetes mellitus, lipid metabolism dysfunction, or hypertension in Japanese patients with schizophrenia