Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data

Japanese laser interferometric gravitational wave detectors, TAMA300 and LISM, performed a coincident observation during 2001. We perform a coincidence analysis to search for inspiraling compact binaries. The length of data used for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors are operated simultaneously. TAMA300 and LISM data are analyzed by matched filtering, and candidates for gravitational wave events are obtained. If there is a true gravitational wave signal, it should appear in both data of detectors with consistent waveforms characterized by masses of stars, amplitude of the signal, the coalescence time and so on. We introduce a set of coincidence conditions of the parameters, and search for coincident events. This procedure reduces the number of fake events considerably, by a factor $\sim 10^{-4}$ compared with the number of fake events in single detector analysis. We find that the number of events after imposing the coincidence conditions is consistent with the number of accidental coincidences produced purely by noise. We thus find no evidence of gravitational wave signals. We obtain an upper limit of 0.046 /hours (CL $= 90$) to the Galactic event rate within 1kpc from the Earth. The method used in this paper can be applied straightforwardly to the case of coincidence observations with more than two detectors with arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in Physical Review

Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

Diagnostic accuracy of Japanese posttraumatic stress measures after a complex disaster: The Fukushima Health Management Survey

Background: The PTSD Checklist (PCL) has also been widely used among traumatized populations to screen people with posttraumatic stress disorder (PTSD); however, the Japanese version of the PCL has yet to be validated. We examined the diagnostic accuracy of the Japanese version of PCL-Specific (PCL-S) and the abbreviated versions of the PCL-S among the evacuees of the Fukushima Daiichi Nuclear Power Plant accident. Methods: Fifty-one participants were recruited from an evacuee and clinical sample. The PCL-S, Impact of Event Scale-Revised (IES-R), and World Health Organization Composite International Diagnostic Interview were administered. Screening properties of the PCL-S, IES-R, and abbreviated PCL-S against PTSD diagnosis, including sensitivity, specificity, and diagnostic efficiency, were calculated. Receiver operating characteristic curves were drawn and optimal cut-off points were examined. Results: The sensitivity, specificity, and diagnostic efficiency of the PCL-S was 66.7%, 84.9%, and 79.2%, respectively (at 52, the area under the curve was 0.83). The cut-off point method for the PCL-S performed better than did the symptom cluster method. The screening properties of the abbreviated versions were comparable to those of the full version. Conclusions: The Japanese version of the PCL-S showed moderate diagnostic accuracy and improved performance over the IES-R for DSM-IV-based PTSD diagnosis. The Japanese version of the PCL-S was a reliable and valid measure, and its diagnostic accuracy was reasonable for both full and abbreviated versions

The association between self-reported sleep dissatisfaction after the Great East Japan Earthquake, and a deteriorated socioeconomic status in the evacuation area: the Fukushima Health Management Survey

Background: Currently, few studies have thoroughly investigated the socioeconomic factors related to sleep problems among evacuees following a disaster. Objectives: To examine sleep problems in evacuees using data from a large-scale cohort survey of evacuees conducted after the 2011 Great East Japan Earthquake (GEJE). Methods: In sum, 73,433 residents who were living in evacuation zones responded to The 2011 Fukushima Health Management Survey. We excluded 16,659 participants who did not answer the question about sleep problems or those younger than 20 years. Thus, data from 56,774 participants (24,959 men and 31,815 women) were used for this analysis. Evacuees' self-reported sleep dissatisfaction was determined based on their response to the question 'Are you satisfied with the quality of your sleep? '. The response options 'Unsatisfied' and 'Very unsatisfied' were considered as the outcome for the present study. Prevalence ratios (PRs) and 95% confidence intervals (CIs) for the prevalence of self-reported sleep disturbance were estimated using modified Poisson regression models. Results: Of the qualifying survey respondents, 20.3% (4387 men and 7128 women) reported sleep dissatisfaction. Compared with participants living in their own or a relative's home (PR = 1), those living in temporary housing or rental accommodation had a higher prevalence of sleep dissatisfaction (1.47; 95% CI 1.44-1.50 and 2.16; 95% CI 2.07-2.26 in men; 1.39; 95% CI 1.36-1.41 and 1.92; 95% CI 1.86-1.99 in women). Higher educational attainment was also associated with a higher prevalence of sleep dissatisfaction in men, as were job loss and decreased income in both men and women. Conclusion: Self-reported sleep dissatisfaction after the GEJE was associated with a deteriorated socioeconomic status among evacuees. However, future longitudinal studies are warranted

Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

Stable Operation of a 300-m Laser Interferometer with Sufficient Sensitivity to Detect Gravitational-Wave Events within our Galaxy

TAMA300, an interferometric gravitational-wave detector with 300-m baseline length, has been developed and operated with sufficient sensitivity to detect gravitational-wave events within our galaxy and sufficient stability for observations; the interferometer was operated for over 10 hours stably and continuously. With a strain-equivalent noise level of $h\sim 5 \times 10^{-21} /\sqrt{\rm Hz}$, a signal-to-noise ratio (SNR) of 30 is expected for gravitational waves generated by a coalescence of 1.4 $M_\odot$-1.4 $M_\odot$ binary neutron stars at 10 kpc distance. %In addition, almost all noise sources which limit the sensitivity and which %disturb the stable operation have been identified. We evaluated the stability of the detector sensitivity with a 2-week data-taking run, collecting 160 hours of data to be analyzed in the search for gravitational waves.Comment: 5 pages, 4 figure

Development and Evaluation of a Gatekeeper Training Program Regarding Anxiety about Radiation Health Effects Following a Nuclear Power Plant Accident: A Single-Arm Intervention Pilot Trial

After the Fukushima Daiichi Nuclear Power Plant accident in March 2011, residents perceived a radiation exposure risk. To address the concerns about radiation exposure and the subsequent effects on their health, we developed the gatekeeper training program for radiation health anxiety and mental health issues. The program consisted of a presentation and roleplay, with educational objectives to the increase knowledge and understanding around radiation health anxiety, alcoholism, depression, and suicide. Twenty-six counselors participated in the program as a single-arm intervention. To measure the outcomes, the subjects reported self-confidence when they counselled with residents with radiation health anxiety and other mental health issues. Comparing the answers to pre- and 2-month follow-up surveys, the confidence levels were higher after 2 months than at baseline, especially for the question “How confident are you at supporting a resident with mental health issues?”, which showed the largest increase (p < 0.001). Regarding radiation health anxiety the questions “Can you communicate coping skills to a resident with radiation health anxiety?” (p = 0.007) and “Can you refer a resident with radiation health anxiety to professionals who can cope appropriately?” (p = 0.016) showed significant increases in their confidence levels. This program could be useful for on-going health activities and future nuclear disasters