Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)

As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.Comment: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correctio

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VI: The Sixth Year (2013-2014)

Continuing the project described by Kato et al. (2009, PASJ, 61, S395, arXiv:0905.1757), we collected times of superhump maxima for 56 SU UMa-type dwarf novae mainly observed during the 2013-2014 season and characterized these objects. We detected negative superhumps in VW Hyi and indicated that the low number of normal outbursts in some supercycle can be interpreted as a result of the disk tilt. This finding, combined with the Kepler observation of V1504 Cyg and V344 Lyr, suggests that the disk tilt is responsible for modulating the outburst pattern in SU UMa-type dwarf novae. We also studied the deeply eclipsing WZ Sge-type dwarf nova MASTER OT J005740.99+443101.5 and found evidence of a sharp eclipse during the phase of early superhumps. The profile can be reproduced by a combination of the eclipse of the axisymmetric disk and the uneclipsed light source of early superhumps. This finding confirms the lack of evince of a greatly enhanced hot spot during the early stage of WZ Sge-type outburst. We detected growing (stage A) superhumps in MN Dra and give a suggestion that some of SU UMa-type dwarf novae situated near the critical condition of tidal instability may show long-lasting stage A superhumps. The large negative period derivatives reported in such systems can be understood a result of the combination of stage A and B superhumps. The WZ Sge-type dwarf novae AL Com and ASASSN-13ck showed a long-lasting (plateau-type) rebrightening. In the early phase of the rebrightening, both objects showed a precursor-like outburst, suggesting that the long-lasting rebrightening is triggered by a precursor outburst.Comment: 73 pages, 88 figures, accepted for publication in PAS

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. III: The Third Year (2010--2011)

Continuing the project described by Kato et al. (2009, PASJ 61, S395, arXiv:0905.1757), we collected times of superhump maxima for 51 SU UMa-type dwarf novae mainly observed during the 2010-2011 season. Although most of the new data for systems with short superhump periods basically confirmed the findings by Kato et al. (2009) and Kato et al. (2010, PASJ 62, 1525, arXiv:1009.5444), the long-period system GX Cas showed an exceptionally large positive period derivative. An analysis of public Kepler data of V344 Lyr and V1504 Cyg yielded less striking stage transitions. In V344 Lyr, there was prominent secondary component growing during the late stage of superoutbursts, and the component persisted at least for two more cycles of successive normal outbursts. We also investigated the superoutbursts of two conspicuous eclipsing objects: HT Cas and the WZ Sge-type object SDSS J080434.20+510349.2. Strong beat phenomena were detected in both objects, and late-stage superhumps in the latter object had an almost constant luminosity during the repeated rebrightenings. The WZ Sge-type object SDSS J133941.11+484727.5 showed a phase reversal around the rapid fading from the superoutburst. The object showed a prominent beat phenomenon even after the end of the superoutburst. A pilot study of superhump amplitudes indicated that the amplitudes of superhumps are strongly correlated with orbital periods, and the dependence on the inclination is weak in systems with inclinations smaller than 80 deg.Comment: 87 pages, 92 figures, Accepted for publication in PASJ, correction in the author list and tex

Isolation and characterization of a virus (CvV-BW1) that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan

<p>Abstract</p> <p>Background</p> <p>We performed an environmental study of viruses infecting the symbiotic single-celled algae of <it>Paramecium bursaria </it>(<it>Paramecium bursaria Chlorella </it>virus, PBCV) in Lake Biwa, the largest lake in Japan. The viruses detected were all <it>Chlorella variabilis </it>virus (CvV = NC64A virus). One of them, designated CvV-BW1, was subjected to further characterization.</p> <p>Results</p> <p>CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the <it>dnapol </it>gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A.</p> <p>Conclusions</p> <p>We conclude that CvV-BW1 composes a distinct species within <it>C. variabilis </it>virus.</p

Dose-escalated Salvage Whole-pelvic Radiotherapy for Biochemical Recurrence After Radical Prostatectomy for High-risk Prostate Cancer

Background/Aim: To investigate the institutional experience of dose-escalated salvage whole-pelvic radiotherapy (WPRT) with the simultaneous integrated boost (SIB) technique in patients with biochemical recurrence (BCR) after radical prostatectomy for high-risk prostate cancer. Patients and Methods: This retrospective study included 21 patients with BCR who received radical prostatectomy for high-risk prostate cancer and underwent salvage RT. Clinical target volume (CTV) of the whole pelvis (CTV56) included the prostate bed, common iliac, external iliac, internal iliac, and obturator lymph node regions. The boost CTV (CTV66) included the prostate bed. Planning target volumes (PTV) were generated by adding a margin of 6-8 mm to CTV (PTV56 and PTV66). Doses of 56.1 and 66 Gy in 33 fractions were delivered to PTV56 and PTV66, respectively. Results: The 5-year biochemical progression-free survival, overall survival, and cause-specific survival rates were 72%, 94%, and 94%, respectively. A grade 3 late genitourinary toxicity event of gross hematuria was observed in one patient (4%). Acute and late toxicities of grade ≥3, other than gross hematuria, were not observed in any patient. Conclusion: Dose-escalated salvage WPRT using the SIB technique provides appropriate tumor control without increasing the incident of significant toxicities.Cancer Diagnosis and Prognosis, 4(3), pp.315-319; 2024journal articl