41 research outputs found

    Cosmological Constraints on Newton's Constant

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    We present cosmological constraints on deviations of Newton's constant at large scales, analyzing latest cosmic microwave background (CMB) anisotropies and primordial abundances of light elements synthesized by big bang nucleosynthesis (BBN). BBN limits the possible deviation at typical scales of BBN epoch, say at 10^8 \sim 10^12m, to lie between -5% and +1% of the experimental value, and CMB restricts the deviation at larger scales 10^2 \sim 10^9pc to be between -26% and +66% at the 2\sigma confidence level. The cosmological constraints are compared with the astronomical one from the evolution of isochrone of globular clusters.Comment: 4 pages, 5 figure

    Effect of Primordial Magnetic Field on Seeds for Large Scale Structure

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    Magnetic field plays a very important role in many astronomical phenomena at various scales of the universe. It is no exception in the early universe. Since the energy density, pressure, and tension of the primordial magnetic field affect gravitational collapses of plasma, the formation of seeds for large scale structures should be influenced by them. Here we numerically investigate the effects of stochastic primordial magnetic field on the seeds of large scale structures in the universe in detail. We found that the amplitude ratio between the density spectra with and without PMF (∣P(k)/P0(k)∣|P(k)/P_0(k)| at k>0.2k>0.2 Mpc−1^{-1}) lies between 75% and 130% at present for the range of PMF strengths 0.5 nG <Bλ<1.0< B_\lambda < 1.0 nG, depending on the spectral index of PMF and the correlation between the matter density and the PMF distributions.Comment: 20 pages, 5 figures, submitted to PRD 23 Jan 2006, Revised 02 Oct 2006, accepted for publication in PR

    Complement activation pathways associated with islet cell surface antibody (ICSA) derived from child patients with insulin-dependent diabetes mellitus (IDDM).

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    We studied the pathways of complement activation associated with the islet cell surface antibody (ICSA) obtained from sera of 7 patients (age less than 15 years) with insulin dependent diabetes mellitus (IDDM). The target cells were 51CR labelled rat islet cells and the complement source was human AB serum. Complement-dependent antibody mediated cytotoxicity (CAMC activity) was obtained using the percentage of cytotoxicity. CAMC activity of untreated sera was significantly inhibited by treating with EGTA or EDTA (p less than 0.001). The CAMC activity of EDTA-treated sera was significantly lower than that of EGTA-treated sera (p less than 0.001). In the inactivated human AB serum, it was lower than that of EGTA-treated sera (p less than 0.05), but not different from that of EDTA-treated sera. These results show that the complement activation associated with ICSA in patients occurred not only via the classical pathway but also via the alternative pathway.</p

    What Factors are Involved in the Knowledge Necessary for the Self-Management of Diabetic Patients?

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    The aim of this study is to obtain data for improving a training program for patients with diabetes mellitus. One hundred eighty-seven patients with non-insulin dependent diabetes mellitus were tested with 20 questions about their knowledge for self-management of diabetes mellitus. Then to draw out factors in their personal backgrounds relating to their correct answers, multiple regression analyses were conducted. As a result, four factors showed significant differences in the following order: Educational careers &#62; ages &#62; duration of disease &#62; socioeconomic strata. The results of the present study have shown for the first time, that these four factors closely concern patients to acquire the necessary knowledge for their self-management of the disease. In addition, this study has raised some fundamental problems regarding the training program for patients: how education should be given to patients.</p

    The Japanese space gravitational wave antenna; DECIGO

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    DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries of the universe such as dark energy, formation mechanism of supermassive black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of three drag-free spacecraft, whose relative displacements are measured by a differential Fabry– Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre- DECIGO first and finally DECIGO in 2024

    DECIGO pathfinder

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    DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article

    Current status of space gravitational wave antenna DECIGO and B-DECIGO

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    Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is the future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could be produced during the inflationary period right after the birth of the universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in the heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry-Perot Michelson interferometers with an arm length of 1,000 km. Three clusters of DECIGO will be placed far from each other, and the fourth cluster will be placed in the same position as one of the three clusters to obtain the correlation signals for the detection of the primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder of DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand the multi-messenger astronomy.Comment: 10 pages, 3 figure

    The status of DECIGO

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    DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometers are arranged on heliocentric orbit around the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present

    2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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