A Geometrical Relationship between Broad-Line Clouds and an Accretion Disk around Active Galactic Nuclei

Recent hard X-ray spectroscopy of active galactic nuclei has strongly suggested that double-peaked, very broad Fe K emission arises from an accretion disk around the central engine. Model fitting of the observed Fe K emission line profile makes it possible to estimate a probable inclination angle of the accretion disk. In order to study the geometrical relationship between the accretion disk and broad emission-line regions (BLRs), we investigate the correlation between the inclination angle of the accretion disk and the velocity width of BLRs for 18 type-1 Seyfert galaxies. We found that there may be a negative correlation between them, i.e., Seyfert nuclei with a more face-on accretion disk tend to have larger BLR velocity widths, suggesting that the BLRs are not coplanar with respect to the accretion disk. The most probable interpretation may be that the BLRs arise from outer parts ({\it r} $\sim$ 0.01 pc) of a warped accretion disk illuminated by the central engine.Comment: 11 pages, 3 figures; accepted for Publications of the Astronomical Society of Japa

Can The Majorana neutrino CP-violating phases be restricted ?

We reanalyze the constraints in neutrino masses and MNS lepton mixing parameters using the new data from the terrestrial (KamLAND) and astrophysical (WMAP) observations together with the HEIDELBERG-MOSCOW double beta decay experiment. It leads us to the almost degenerate or inverse hierarchy neutrino mass scenario. We discuss the possibility of getting the bound for the Majorana CP violating phase.Comment: 6 pages, 2 figure

Mesa-type patterns in the one-dimensional Brusselator and their stability

The Brusselator is a generic reaction-diffusion model for a tri-molecular chemical reaction. We consider the case when the input and output reactions are slow. In this limit, we show the existence of $K$-periodic, spatially bi-stable structures, \emph{mesas}, and study their stability. Using singular perturbation techniques, we find a threshold for the stability of $K$ mesas. This threshold occurs in the regime where the exponentially small tails of the localized structures start to interact. By comparing our results with Turing analysis, we show that in the generic case, a Turing instability is followed by a slow coarsening process whereby logarithmically many mesas are annihilated before the system reaches a steady equilibrium state. We also study a ``breather''-type instability of a mesa, which occurs due to a Hopf bifurcation. Full numerical simulations are shown to confirm the analytical results.Comment: to appear, Physica

Kiso observations for 20 GRBs in HETE-2 era

We have established a GRB follow-up observation system at Kiso observatory (Japan) in 2001. Since the east Asian area had been blank for the GRB follow-up observational network, this observational system is very important in studying the temporal and spectral evolution of early afterglows. Using this system, we have performed quick observations for optical afterglows from early phase based on HETE-2 and INTEGRAL alerts. Thanks to the quick follow-up observation system, we have been able to use the Kiso observatory in 20 events, and conduct their follow-up observations in optical and near infrared wavelengths.Comment: 5 pages, 4 figure. Accepted for publication into "il nuovo cimento". Proceeding of the 4th Rome GRB conference, eds. L. Piro, L. Amati, S. Covino, B. Gendr

CP Violations in Lepton Number Violation Processes and Neutrino Oscillations

We examine the constraints on the MNS lepton mixing matrix from the present and future experimental data of the neutrino oscillation and lepton number violation processes. We introduce a graphical representation of the CP violation phases which appear in the lepton number violation processes such as neutrinoless double beta decay, the $\mu^--e^+$ conversion, and the K decay, $K^-\to\pi^+\mu^-\mu^-.$ Using this graphical representation, we derive the constraints on the CP violation phases in the lepton sector.Comment: 21pp, REVTeX, 9 Figure

Dementia-specific risks of scabies: Retrospective epidemiologic analysis of an unveiled nosocomial outbreak in Japan from 1989-90

Background: Although senile dementia patients in long-term care facilities are at leading risk of scabies, the epidemiologic characteristics of this disease have yet to be fully clarified. This study documents the findings of a ward-scale nosocomial outbreak in western Japan from 1989-90, for which permission to publish was only recently obtained. Methods: A retrospective epidemiologic study was performed to identify specific risk factors of scabies among patients with dementia. Analyses were based on a review of medical and nursing records. All inpatients in the affected ward at the time of the outbreak were included in the study. Observational and analytical approaches were employed to assess the findings. Results: Twenty of 65 inpatients in the ward met the case definition of scabies. The outbreak. lasted for almost 10 months and as a result, the spatial distribution of infections showed no localized patterns in the latter phase of the outbreak. The duration of illness significantly decreased after initiation of control measures (P = 0.0067). Movement without assistance (Odds Ratio [OR] = 11.3; 95% Confidence Interval [CI]: 2.9,44.8) and moving beyond the room (but within the ward) (OR=4.1; 95% CI: 1.4, 12.5) were significantly associated with infection, while types of room (Western or Japanese) and sleeping arrangement (on beds or futons laid directly on the floor) appeared not to be risk factors. Conclusion: Univariate analysis demonstrated the importance of patients' behaviours during daily activities in controlling scabies among senile dementia patients. The findings also support previous evidence that catching scabies from fomites is far less common. Moreover, since cognitive disorders make it difficult for individuals to communicate and understand the implications of risky contacts as well as treatment method, and given the non-specific nature of individual contacts that are often unpredictable, real-time observations might help improve control practices. © 2005 Tsutsumi et al., licensee BioMed Central Ltd.published_or_final_versio