A Theoretical Light-Curve Model for the 1999 Outburst of U Scorpii

A theoretical light curve for the 1999 outburst of U Scorpii is presented in order to obtain various physical parameters of the recurrent nova. Our U Sco model consists of a very massive white dwarf (WD) with an accretion disk and a lobe-filling, slightly evolved, main-sequence star (MS). The model includes a reflection effect by the companion and the accretion disk together with a shadowing effect on the companion by the accretion disk. The early visual light curve (t ~ 1-15 days after maximum) is well reproduced by a thermonuclear runaway model on a very massive WD close to the Chandrasekhar limit (M_{WD}= 1.37 \pm 0.01 M_\odot), in which optically thick winds blowing from the WD play a key role in determining the nova duration. The duration of the strong wind phase (t~0-17 days) is very consistent with the BeppoSAX supersoft X-ray detection at t~19-20 days because supersoft X-rays are self-absorbed by the massive wind. The envelope mass at the peak is estimated to be ~3x10^{-6} M_\odot, which is indicating an average mass accretion rate ~2.5x10^{-7} M_\odot yr^{-1} during the quiescent phase between 1987 and 1999. These quantities are exactly the same as those predicted in a new progenitor model of Type Ia supernovae.Comment: 7 pages, 3 figures, to appear in ApJL, vol. 52

Feelings of Wellbeing in Adolescents – A Cross-cultural Study of Finnish and Japanese Students

The purpose of this study was to investigate how students studying in sixth and eighth grade in very different contexts evaluate their own psychological wellbeing. The study was conducted with 697 Finnish and 721 Japanese students. The study aimed to explore if there were differences between the wellbeing of Finnish and Japanese male and fe­male sixth and eighth grade students. The same questionnaire was used as a measure in both countries. According to the results, the Japanese students more often suffered from psychosomatic symptoms, symptoms of impulsiveness, social anxiety, and problems of controlling emotions than Finnish students. The Finnish students more often admitted to problems in their social relationships. The eighth graders revealed more symptoms than the sixth graders and the girls more than the boys. The smallest wellbeing score was obta­ined by Japanese eighth grade girls.</p

Usefulness of peripherally inserted central catheters

Introduction : Central venous catheter (CVC) use is essential for treating esophageal cancer. Peripherally inserted central catheters (PICC) are commonly used recently for improved patient comfort and safety. We compared centrally inserted central catheters (CICC) and PICC insertions and examined their safety. Methods : We retrospectively investigated complications at the catheter insertion and post-insertion for 199 patients’ esophageal cancer treatment (CICC : 45, PICC : 154) from 2013 to 2018. In addition, we summarized the results of catheter tip culture. Results : No serious complications occurred at the catheter insertion in either group. The rate of complications at catheter insertion was 5.8% for PICC and 6.7% for CICC patients. Post-insertion complications were observed in 6.5% and 11.1% of patients with PICC and CICC, respectively, and this difference was not significant. The incidence of catheter-related blood stream infection (CRBSI) was significantly lower in PICC than CICC patients (0.3 vs. 1.8 / 1,000 catheter-days ; p = 0.029). Catheter-related thrombosis was observed in PICC : 0.5 and CICC : 0.6, and occlusion due to blood flow reversal was observed in PICC : 0.5 and CICC : 0.6. Conclusion : PICCs are safer and more effective than CICCs for the treatment of esophageal cancer, and reduce the incidence of CRBSI. We hope to standardize the insertion procedures, conventionalize techniques, and establish training systems