Bayesian Approach to Find a Long-Term Trend in Erratic Polarization Variations Observed in Blazars

We developed a method to separate a long-term trend from observed temporal variations of polarization in blazars using a Bayesian approach. The temporal variation of the polarization vector is apparently erratic in most blazars, while several objects occasionally exhibited systematic variations, for example, an increase of the polarization degree associated with a flare of the total flux. We assume that the observed polarization vector is a superposition of distinct two components, a long-term trend and a short-term variation component responsible for short flares. Our Bayesian model estimates the long-term trend which satisfies the condition that the total flux correlates with the polarized flux of the short-term component. We demonstrate that assumed long-term polarization components are successfully separated by the Bayesian model for artificial data. We applied this method to photopolarimetric data of OJ 287, S5 0716+714, and S2 0109+224. Simple and systematic long-term trends were obtained in OJ 287 and S2 0109+224, while no such a trend was identified in S5 0716+714. We propose that the apparently erratic variations of polarization in OJ 287 and S2 0109+224 are due to the presence of the long-term polarization component. The behavior of polarization in S5 0716+714 during our observation period implies the presence of a number of polarization components having a quite short time-scale of variations.Comment: 12 pages, 7 figures, accepted for publication in PAS

Photopolarimetric Monitoring of Blazars in the Optical and Near-Infrared Bands with the Kanata Telescope. I. Correlations between Flux, Color, and Polarization

We report on the correlation between the flux, color and polarization variations on time scales of days--months in blazars, and discuss their universal aspects. We performed monitoring of 42 blazars in the optical and near-infrared bands from 2008 to 2010 using TRISPEC attached to the "Kanata" 1.5-m telescope. We found that 28 blazars exhibited "bluer-when-brighter" trends in their whole or a part of time-series data sets. This corresponds to 88% of objects that were observed for >10 days. Thus, our observation unambiguously confirmed that the "bluer-when-brighter" trend is common in the emission from blazar jets. This trend was apparently generated by a variation component with a constant and relatively blue color and an underlying red component. Prominent short-term flares on time scales of days--weeks tended to exhibit a spectral hysteresis; their rising phases were bluer than their decay phases around the flare maxima. In contrast to the strong flux--color correlation, the correlation of the flux and polarization degree was relatively weak; only 10 objects showed significant positive correlations. Rotations of polarization were detected only in three objects: PKS 1510-089, 3C 454.3, and PKS 1749+096, and possibly in S5 0716+714. We also investigated the dependence of the degree of variability on the luminosity and the synchrotron peak frequency, \nu_peak. As a result, we found that lower luminosity and higher \nu_peak objects had smaller variations in their amplitudes both in the flux, color, and polarization degree. Our observation suggests the presence of several distinct emitting sources, which have different variation time-scales, colors, and polarizations. We propose that the energy injection by, for example, internal shocks in relativistic shells is a major factor for blazar variations on time scales of both days and months.Comment: 39 pages, accepted for publication in PAS

A pediatric case of productive cough caused by novel variants in DNAH9

We report the first Japanese case of primary ciliary dyskinesia caused by DNAH9 variations. The patient, a 5-year-old girl, had repeated episodes of productive cough after contracting the common cold at the age of 1 year and 6 months. She did not have a situs abnormality or congenital heart defect. We identified two novel DNAH9 variants, NM_001372.3: c. [1298C>G];[5547_5550delTGAC], (p.[Ser433Cys];[Asp1850fs])

Frequent association of thrombophilia in cerebral venous sinus thrombosis

application/pdfThrombophilia is frequently associated with venous thromboembolism (VTE) including cerebral venous sinus thrombosis (CVST). The possibility of thrombophilia was examined in 12 patients with CSVT diagnosed in the past 9 years. Thrombophilia due to abnormalities in antithrombin(AT), protein C (PC), or protein S (PS) or antiphospholipid syndrome (APS) was evaluated. Nine patients with abnormally decreased AT, PC or PS and one patient with APS were examined. Of the nine patients examined by a gene analysis of AT, PC, or PS, one had a congenital AT deficiency, one had a congenital PC deficiency, and two had congenital PS deficiencies including a novel mutant(Gly189Ala). AT, PC and PS levels were all decreased in one patient, PS level was decreased in three patients, and AT level was decreased in one patient at the onset of CVST, but these concentrations improved after treatment. CVST is frequently associated with thrombophilia and a transient decrease in AT, PC or PS may be a causal factor.本文/Central Laboratory, Mie University Graduate School of Medicine, Tsu, Japan6

Frequent association of thrombophilia in cerebral venous sinus thrombosis

application/pdf内容の要旨・審査結果の要旨 / 三重大学大学院医学系研究科生命医科学専攻病態解明医学講座臨床検査医学分