230 research outputs found
Circumnuclear Multi-phase Gas in the Circinus Galaxy. V. The Origin of the X-Ray Polarization in the Circinus Galaxy
The Imaging X-ray Polarimetry Explorer (IXPE) detected X-ray polarization in
the nearest Seyfert 2 galaxy, the Circinus galaxy, for the first time. To
reproduce the IXPE results, we computed the degree of polarization based on two
types of radiative hydrodynamic simulations: a parsec-scale three-dimensional
model and a sub-parsec-scale axisymmetric model with a higher spatial
resolution. In a series of papers, we confirmed that these models naturally
explain the multi-wavelength observations of the Circinus galaxy from radio to
X-rays. We used a Monte Carlo Simulation for Astrophysics and Cosmology code to
compute the linear polarization of continuum emission. We found that the degree
of polarization based on the parsec-scale radiation-driven fountain model was
smaller than that observed with the IXPE. The degree of polarization based on
the sub-parsec-scale model depends on the hydrogen number density of the disk
(), and the degree of polarization obtained from our simulation is
consistent with that observed with the IXPE in the case of . We investigate where the photons are Compton
scattered and imply that the origin of the X-ray polarization in the Circinus
galaxy is the outflow inside . In this case, the degree of
polarization may change over a timescale of approximately ten years.Comment: 11 pages, 8 figures, accepted for publication in Ap
The (CTG)n polymorphism in the NOTCH4 gene is not associated with schizophrenia in Japanese individuals
BACKGROUND: The human NOTCH4 gene is a candidate gene for schizophrenia due to its chromosomal location and neurobiological roles. In a British linkage study, NOTCH4 gene polymorphisms were highly associated with schizophrenia. In a Japanese case-control association study, however, these polymorphisms did not show significant associations with schizophrenia. We conducted a case-control study with Japanese subjects to explore an association between the triplet repeat polymorphism in the NOTCH4 gene and schizophrenia, including subtypes of schizophrenia, longitudinal disease course characteristics, and a positive family history for psychoses. METHODS: We examined the (CTG)n repeat polymorphism in the NOTCH4 gene among 100 healthy Japanese individuals and 102 patients with schizophrenia (22 paranoid, 38 disorganized, 29 residual, 64 episodic, 31 continuous, 42 with prominent negative symptoms, and 46 with positive family histories) using a polymerase chain reaction-based, single-strand conformational polymorphism analysis. RESULTS: Five different alleles consisting of 6, 9, 10, 11, and 13 repeats of CTG (Leu) in patients with schizophrenia, and 4 alleles consisting of 6, 9, 10, and 11 repeats in controls were found. No significant differences in genotype or allele frequencies of repeat numbers were found between controls and patients. In addition, there were no associations between the polymorphism and schizophrenia subtypes, longitudinal disease course characteristics, or positive family history of the patients. CONCLUSIONS: Our data suggest a lack of association between the NOTCH4 gene triplet repeat polymorphism and schizophrenia in Japanese individuals
加温後のtsAF8細胞の細胞周期
Thermotolerance in tsAF8 cells develops during incubation at 34℃ after heating at 45℃, while it is suppressed by the following incubation at a non-permissive temperature
of 39.7℃ after the same heating. The incubation temperature after heating may affect the cell cycle and consequently thermotolerance. In the present study, a relationship between the thermotolerance and the cell cycle of tsAF8 was investigated. The cell cycle fractions and DNA synthesis were measured by flow cytometry using double staining with propidium iodide and bromodeoxyuridine. When the tsAF8 cells were heated at 45℃ for 20 min, and thereafter incubated at 34℃, bromodeoxyuridine uptake in the S phase cells (DNA synthesis) was recovered to 65.1% 6 h after the heating, and the cells showed gradual accumulation in the G(2)/M phase. When the cells were incubated at 39.7℃ after heating at 45℃ for 20 min, then showed inhibition of thermotolerance development, the DNA synthesis was recovered to 15.1% temporarily 6 h after the heating, but it became 0% after 12 h, and the cells did not remarkably accumulate in any phases of the cell cycle. This inhibition of DNA synthesis at 39.7℃ was considered to be the result of cell survival decreasing by a step-down heating. However, the relationship between the thermotolerance and the cell cycle was not found out in tsAF8 cells, because the cells did not accumulate in any phases of the cell cycle under the inhibitory condition of thermotolerance.tsAF8細胞は45℃の加温後34℃で培養すると温熱耐性が速やかに発現するが,加温後,制限温度である39.7℃で培養すると温熱耐性の発現が抑制される。加温後の培養温度が細胞周期に影響し,その結果として温熱耐性発現に影響を与えている可能性があることから,今回,Propidium Iodide(PI)とbromodeoxyuridine(BrdU)でtsAF8細胞を二重染色し,フローサイトメトリーによって温熱耐性と細胞周期の関係の有無について調べた。tsAF8細胞を45℃20分の加温後34℃で培養すると,6時間後にはG(1)期の細胞が減少し,12時間後にはG(2)/M期への蓄積が見られた。しかし,加温後39.7℃で培養した場合には細胞周期の進行がほとんど見られなかった。BrdU の取込みは,加温せずに39.7℃で培養した場合には活発に行われ,また,45℃20分加温後34℃で培養した場合には,6時間後にはBrdUの取り込みは65.1%まで回復した。しかし,温熱耐性発現の抑制が観察される45℃20分加温後39.7℃で培養した場合には,BrdUの取込み量は6時間後に一時的に15.1%に回復するが,12時間後には取込み量はゼロとなった。BrdUの取り込みが阻害されたのはstep-down heatingの現象による細胞生存率の減少が原因だと考えられたが,温熱耐性発現の抑制が観察される条件下では細胞周期の特定の時期への集積がなかったことから,温熱耐性と細胞周期との関係はtsAF8細胞においては見い出されなかった
Application of X-Ray Clumpy Torus Model (XCLUMPY) to 10 Obscured Active Galactic Nuclei Observed with Suzaku and NuSTAR
We apply XCLUMPY, an X-ray spectral model from a clumpy torus in an active
galactic nucleus (AGN), to the broadband X-ray spectra of 10 obscured AGNs
observed with both Suzaku and NuSTAR. The infrared spectra of these AGNs were
analyzed with the CLUMPY code. Since XCLUMPY adopts the same clump distribution
as that in the CLUMPY, we can directly compare the torus parameters obtained
from the X-ray spectra and those from the infrared ones. The torus angular
widths determined from the infrared spectra () are
systematically larger than those from the X-ray data ();
the difference () correlates with the
inclination angle determined from the X-ray spectrum. These results can be
explained by the contribution from dusty polar outflows to the observed
infrared flux, which becomes more significant at higher inclinations (more
edge-on views). The ratio of the hydrogen column density and V-band extinction
in the line of sight absorber shows large scatter (1 dex) around the
Galactic value, suggesting that a significant fraction of AGNs have dust-rich
circumnuclear environments.Comment: 17 pages, 3 figures, accepted for publication in Ap
Emission image of X-ray-irradiated CR-39 stick doped with methylviologen-encapsulated silica nanocapsules using LED light
Light-emitting diode (LED)-light-excited emission images of 6 MeV-X-ray (10 Gy)-irradiated CR-39 doped with methylviologen-encapsulated silica nanocapsules (MV @SiO2 NCs) were observed using an iPhone 5S for the first time. The excitation and fluorescence spectra were also observed, and the emission peak at 580 nm produced by the X-ray irradiation was confirmed. Emission intensities of 80 kV-X-ray (0.5, 1, 1.5, and 2 Gy)-irradiated CR-39 doped with MV @ SiO2 NCs could be measured using a portable fluorometer (FC-1), and a good linear relationship between their emission intensity and dose was clearly observed
Study of hadron interactions in a lead-emulsion target
Topological and kinematical characteristics of hadron interactions have been
studied using a lead-emulsion target exposed to 2, 4 and 10 GeV/c hadron beams.
A total length of 60 m tracks was followed using a high speed automated
emulsion scanning system. A total of 318 hadron interaction vertices and their
secondary charged particle tracks were reconstructed. Measurement results of
interaction lengths, charged particle multiplicity, emission angles and momenta
of secondary charged particles are compared with a Monte Carlo simulation and
appear to be consistent. Nuclear fragments emitted from interaction vertices
were also detected by a newly developed emulsion scanning system with
wide-angle acceptance. Their emission angle distributions are in good agreement
with the simulated distributions. Probabilities of an event being associated
with at least one fragment track are found to be greater than 50% for beam
momentum GeV/c and are well reproduced by the simulation. These
experimental results validate estimation of the background due to hadron
interactions in the sample of decay candidates in the OPERA oscillation experiment.Comment: 14 pages, 11 figure
A Study of Reconstruction of Magnetic Resonance Image
磁気共鳴は医学におけるイメージングにおいて重要なモダリティーであり,高度な数学的手法が画像の再構成に取り入れられている。画像再構成の数学的手法および画像再構成にいたるまでの数学的な過程を理解するこは,MRIを学ぶものにとって非常に重要であるが,成書において明確な説明はなされていない。ここでは,MR画像の再構成法を,複素関数と複素フ-リェ係数を用いて導いたので報告する。Magnetic resonance is an important modality for medical imaging, and advanced mathematical techniques are introduced into the reconstruction of images. Clearly
understandable explanations of the reconstruction of the MR image and of the mathematical derivation process have not been presented in the texts. Reconstruction of MR image is presented using the complex function and its relevant Fourier coefficients
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