87 research outputs found

    The Role of Dust in the Early Universe I : Protogalaxy Evolution

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    We develop one-zone galaxy formation models in the early Universe, taking into account dust formation and evolution by supernova (SN) explosions. Especially we focus on the time evolution of dust size distribution, because H2{\rm H}_{2} formation on the dust surface plays a critical role in the star formation process in the early Universe. In the model we assume that star formation rate (SFR) is proportional to the total amount of H2{\rm H}_{2}. We consistently treat (i) the formation and size evolution of dust, (ii) the chemical reaction networks including H2{\rm H}_{2} formation both on the surface of dust and in gas phase, and (iii) the SFR in the model. First, we find that, because of dust destruction due to both reverse and forward shocks driven by SNe, H2_{2} formation is more suppressed than that without dust destruction. At the galaxy age of sim0.8Gyrsim0.8 {\rm Gyr}, for galaxy models with virial mass Mvir=109MM_{\rm vir}=10^{9} M_{\odot} and formation redshift zvir=10z_{\rm vir}=10, the molecular fraction is 2.5 orders of magnitude less in the model with dust destruction by both shocks than that in the model without dust destruction. Second, we show that the H2_{2} formation rate strongly depends on the ISM density around SN progenitors. The SFR in higher ISM density is lower, since dust destruction by reverse shocks is more effective in higher ISM density. We conclude that not only the amount but also the size distribution of dust being related with the star formation activity strongly affects the evolution of galaxies in the early Universe.Comment: 23 pages, 12 figures, 3 tables, Accepted for publication in Ap

    Infusion of angiotensin II reduces loss of glomerular capillary area in the early phase of anti-Thy-1.1 nephritis possibly via regulating angiogenesis-associated factors

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    Infusion of angiotensin II reduces loss of glomerular capillary area in the early phase of anti-Thy-1.1 nephritis possibly via regulating angiogenesis-associated factors.BackgroundAlthough angiotensin II (Ang II) is involved in the progression of renal diseases, infusion of Ang II was reported to surprisingly ameliorate the early phase of anti-Thy-1.1 nephritis (Wenzel et al,Kidney Int 61:1020, 2002). Considering the known proangiogenic effect of Ang II and that angiogenic glomerular capillary repair is required for the recovery of damaged glomeruli in rat anti-Thy-1.1 nephritis, we hypothesized that Ang II infusion starting prior to the initiation of nephritis may induce the expression of angiogenic growth factors such as vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1), resulting in the increased glomerular capillary area in the early phase.MethodsAng II was infused (170ng/min) in rats, and 5 days later, nephritis was induced by the administration of monoclonal 1-22-3 antibodies. Ang II type 1 or type 2 receptor antagonist (AT1R or AT2R, respectively) (losartan or PD123319, respectively) was coadministered.ResultsAng II infusion affected on neither the deposition of Ig nor mesangiolysis in the initial phase, and resulted in the aggravation of creatinine clearance at day 14 and 35 after initiating anti-Thy-1.1 nephritis. Histologic alterations were ameliorated accompanied by reduced loss in rat endothelial cell antigen (RECA)-1(+) endothelial area in Ang II-infused nephritic rats on day 6 and 14 as compared to control nephritic group, and nephritic alterations were mostly resolved on day 35 in both groups. At the early stage (day 6), glomerular expression of VEGF and receptors flk-1 and flt-1 as well as Ang-1, and receptor Tie2 were increased, and glomerular monocyte infiltration and the expression of angiopoietin-2 (Ang-2), a natural antagonist of Ang-1, were reduced. Both Ang II receptors were involved in the regulation of angiogenic factors and receptors.ConclusionThese results demonstrate that infusion of exogenous Ang II starting prior to the induction of nephritis activates VEGF and Ang-1 signaling regulated via both Ang II receptors, potentially leading to the accelerated recovery of injured glomerular endothelial cells in the early phase of anti-Thy-1.1 nephritis. Increased expression of VEGF and Ang-1 on podocytes further suggests the crucial association of endothelial cells and podocytes in maintaining proper glomerular capillary structures

    ナローバンドUVBがHeLa細胞とアレルギー性鼻炎モデルラットの鼻粘膜におけるヒスタミンH1受容体遺伝子発現の亢進とアポトーシスの誘導に与える影響

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    Narrowband-ultraviolet B (NB-UVB) phototherapy is used for the treatment of atopic dermatitis. Previously, we reported that irradiation with 200 mJ/cm2 of 310 nm NB-UVB suppressed phorbol-12- myristate-13-acetate (PMA)-induced up-regulation of histamine H1 receptor (H1R) gene expression without induction of apoptosis in HeLa cells. However, the effect of NB-UVB irradiation on nasal symptoms is still unclear. Here, we show that low dose irradiation with 310 nm NB-UVB alleviates nasal symptoms in toluene 2,4-diisocyanate (TDI)-sensitized allergy model rats. Irradiation with 310 nm NB-UVB suppressed PMA-induced H1R mRNA up-regulation in HeLa cells dose-dependently at doses of 75-200 mJ/cm2 and reversibly at a dose of 150 mJ/cm2 without induction of apoptosis. While, at doses of more than 200 mJ/cm2, irradiation with 310 nm NB-UVB induced apoptosis. Western blot analysis showed that the suppressive effect of NB-UVB irradiation on H1R gene expression was through the inhibition of ERK phosphorylation. In TDI-sensitized rat, intranasal irradiation with 310 nm NB-UVB at an estimated dose of 100 mJ/cm2 once a day for three days suppressed TDI-induced sneezes and upregulation of H1R mRNA in nasal mucosa without induction of apoptosis. These findings suggest that repeated intranasal irradiation with low dose of NB-UVB could be clinically used as phototherapy of AR

    An Investigation and Extension of Tower of Hanoi as a Teaching Material of Mathematics Education

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    В докладе рассматриваются вопросы использования определения инновационные технологии при организации учебного процесса

    The ASTRO-H X-ray Observatory

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    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

    Clinical Outcome of Patients with Pelvic and Retroperitoneal Bone and Soft Tissue Sarcoma : A Retrospective Multicenter Study in Japan

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    This study aimed to retrospectively analyze the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma (BSTS). Overall, 187 patients with BSTS in the pelvis and retroperitoneal region treated at 19 specialized sarcoma centers in Japan were included. The prognostic factors related to overall survival (OS), local control (LC), and progression-free survival (PFS) were evaluated. The 3-year OS and LC rates in the 187 patients were 71.7% and 79.1%, respectively. The 3-year PFS in 166 patients without any distant metastases at the time of primary tumor diagnosis was 48.6%. Osteosarcoma showed significantly worse OS and PFS than other sarcomas of the pelvis and retroperitoneum. In the univariate analyses, larger primary tumor size, soft tissue tumor, distant metastasis at the time of primary tumor diagnosis, P2 location, chemotherapy, and osteosarcoma were poor prognostic factors correlated with OS. Larger primary tumor size, higher age, soft tissue tumor, chemotherapy, and osteosarcoma were poor prognostic factors correlated with PFS in patients without any metastasis at the initial presentation. Larger primary tumor size was the only poor prognostic factor correlation with LC. This study has clarified the epidemiology and prognosis of patients with pelvic and retroperitoneal BSTS in Japan

    The Quiescent Intracluster Medium in the Core of the Perseus Cluster

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    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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