Detection of Fluorine in the Halo Planetary Nebula BoBn 1: Evidence For a Binary Progenitor Star

We have found the fluorine lines [F IV] 3996.92A,4059.90A in the extremely metal-poor ([Ar/H] = -2.10+/-0.21) halo planetary nebula (PN) BoBn 1 in high-dispersion spectra from the 8.2-m VLT/UVES archive. Chemical abundance analysis shows that the fluorine abundance is [F/H] = +1.06+/-0.08, making BoBn 1 the most fluorine-enhanced and metal-poor PN among fluorine-detected PNe and providing new evidence that fluorine is enhanced by nucleosynthesis in low mass metal-poor stars. A comparison with the abundances of carbon-enhanced metal-poor (CEMP) stars suggests that BoBn 1 shares their origin and evolution with CEMP-s stars such as HE1305+0132. BoBn 1 might have evolved from a binary consisting of ~2 Msun primary and ~0.8 Msun secondary stars.Comment: 13 pages, 3 figures, accepted by ApJ Letter

Gender differences in dietary behaviors among Japanese adolescents

Unhealthy dietary behaviors in adolescence are an important public health problem. Gender differences in dietary behaviors have already appeared during adolescence. However, few studies have assessed a variety of adolescent dietary behaviors in Japan. We aimed to clarify gender differences in unhealthy dietary behaviors among Japanese adolescents. The participants consisted of 84,988 participants from seventh to 12th grades. Unhealthy dietary behaviors were defined according to the National Health and Nutrition Survey. Multivariable logistic regression was used to analyze a nationally representative sample of Japanese adolescents from the 2014 to 2015 Lifestyle Survey. The effective response rate was 51.4%. The prevalence of unhealthy dietary behaviors (skipping breakfast, snacking, eating out, skipping meals, eating alone at dinner, and subjectively poor diet quality) among boys and girls was 14.2% versus 12.4%, 19.6% versus 14.1%, 10.6% versus 7.0%, 7.9% versus 5.6%, 13.3% versus 12.1%, and 12.3% versus 15.8%, respectively. Compared with boys, girls were more negatively associated with skipping breakfast [OR = 0.76 (95% CI 0.73–0.79)], snacking [OR = 0.67 (95% CI 0.65–0.70)], eating out [OR = 0.62 (95% CI 0.59–0.66)], skipping meals [OR = 0.61 (95% CI 0.58–0.65)], and eating alone at dinner [OR = 0.79 (95% CI 0.76–0.83)]. However, girls were more positively associated with subjectively poor diet quality [OR = 1.19 (95% CI 1.14.1.24)]. The findings suggest that gender differences existed in dietary behaviors. Gender differences in dietary behaviors suggest opportunities for tailoring interventions related to dietary education in schools

Sacrificial Mechanical Bond is as Effective as a Sacrificial Covalent Bond in Increasing Cross-Linked Polymer Toughness.

Sacrificial chemical bonds have been used effectively to increase the toughness of elastomers because such bonds dissociate at forces significantly below the fracture limit of the primary load-bearing bonds, thereby dissipating local stress. This approach owes much of its success to the ability to adjust the threshold force at which the sacrificial bonds fail at the desired rate, for example, by selecting either covalent or noncovalent sacrificial bonds. Here, we report experimental and computational evidence that a mechanical bond, responsible for the structural integrity of a rotaxane or a catenane, increases the elastomer's fracture strain, stress, and energy as much as a covalent bond of comparable mechanochemical dissociation kinetics. We synthesized and studied 6 polyacrylates cross-linked by either difluorenylsuccinonitrile (DFSN), which is an established sacrificial mechanochromic moiety; a [2]rotaxane, whose stopper allows its wheel to dethread on the same subsecond time scale as DFSN dissociates when either is under tensile force of 1.5-2 nN; a structurally homologous [2]rotaxane with a much bulkier stopper that is stable at force >5.5 nN; similarly stoppered [3]rotaxanes containing DFSN in their axles; and a control polymer with aliphatic nonsacrificial cross-links. Our data suggest that mechanochemical dethreading of a rotaxane without failure of any covalent bonds may be an important, hitherto unrecognized, contributor to the toughness of some rotaxane-cross-linked polymers and that sacrificial mechanical bonds provide a mechanism to control material fracture behavior independently of the mechanochemical response of the covalent networks, due to their distinct relationships between structure and mechanochemical reactivity

Trends in sleep problems and patterns among Japanese adolescents: 2004 to 2017

Background Sleep problems in adolescence, such as insomnia and short sleep duration, are associated with physical and mental health problems. However, little is known about the recent trends in sleep problems among adolescents. Therefore, this study examined trends in sleep problems among Japanese adolescents. Methods Using data from the Lifestyle Survey of Adolescents collected in 2004 (n = 102,451), 2008 (n = 95,680), 2010 (n = 98,867), 2012 (n = 101,134), 2014 (n = 85,931), and 2017 (n = 64,417), we calculated the trends of insomnia, shorter sleep duration, late bedtimes, and poor sleep quality. Multivariable logistic regression analysis models were used to examine the association of each sleep problem and survey years. Findings We analyzed data from 545,285 Japanese adolescents. Results indicated that, since 2004, the odds ratio for insomnia have decreased (Adjusted odds ratio [AOR] 0•85, 95% CI 0•82–0•87), as have the odds ratio for poor sleep quality (AOR 0•92, 95% CI 0•88–0•95). However, the odds ratio for shorter sleep duration (AOR 1•13, 95% CI 1•10–1•17) and late bedtimes tended to increase (AOR 1•06, 95% CI 1•03–1•08) during this period. Interpretation The prevalence of insomnia symptoms and poor sleep quality among adolescents decreased from 2004 to 2017. However, there were increasing trends toward shorter sleep duration and late bedtimes. These changes are both relieving and concerning. Teachers, parents, and health professionals should consider educating adolescents regarding sleep hygiene, adjusting schedules of extracurricular activities, and enhancing time management to improve their sleep quantity

Effectiveness of Screening and Brief Alcohol Intervention at the Workplace: A Study Protocol for a Randomized Controlled Trial at Five Japan-Based Companies

Background: Despite evidence regarding the effectiveness of screening and brief interventions for excessive alcohol use in primary care, these tools are not a part of routine practice. It has been suggested that using these tools at the workplace may be critical to alcohol-associated harm; however, evidence for this claim is unclear. The aim of this article is to develop a study protocol which evaluates the effect of brief alcohol intervention at the workplace to reduce harmful alcohol drinking. Methods: A randomized controlled trial involving employees (aged 20–74 years) of five Japan-based companies who were screened “positive” by Alcohol Use Disorder Identification Test (AUDIT) is on-going. Participants were randomized into “Patient Information Leaflet” (control group), “Brief Advice and Counselling,” and “Five-minute Brief Advice” groups. A self-administered questionnaire was used to assess alcohol consumption, lifestyle behavior, health status, work performance, and consequences of alcohol use. Data of laboratory markers were collected from routine health checkups.Results: A total of 351 participants were randomized into Patient Information Leaflet (n = 111), Brief Advice and Counselling (n = 128), and Five-minute Brief Advice (n = 112) groups. Participants were mostly men with a median age of 49 years. Median AUDIT score and weekly alcohol consumption were 11 points and 238 g/week, respectively. Two-thirds of the participants were manufacturing workers. Conclusion: This study protocol developed the first trial in Japan to investigate the effect of brief alcohol intervention combined with a recommended screening tool at the workplace. Our findings can provide evidence on the effectiveness and relevance of these tools to occupational health

Heat-not-burn tobacco, electronic cigarettes, and combustible cigarette use among Japanese adolescents: a nationwide population survey 2017

Background: From among the global public health concerns, smoking remains one of the most crucial challenges. Especially for adolescents, the increase in the use of electronic cigarettes is controversial, as its use may lead to established smoking. In Japan, where a unique tobacco regulation system exists, the heat-not-burn tobacco market has been growing. However, the prevalence and association of combustible cigarettes and new tobacco-related products have not yet been closely investigated among Japanese adolescents. This study aimed to clarify the prevalence of smoking among adolescents, including new types of tobacco-related products, and to compare the characteristics of their users. Methods: The 2017 Lifestyle Survey of Adolescents is a nationally-representative survey collected in Japan. From the national school directory, 98 junior high schools and 86 high schools were randomly sampled throughout Japan. The students completed an anonymous questionnaire at school. We calculated the prevalence of use for each type of tobacco product. Then, the use of a combination of products and the characteristics of different types of products were examined. Results: In total, 64,152 students from 48 junior high schools and 55 high schools were included the analysis (school response rate = 56%, Mage = 15.7 years, 53.9% boys). The age-adjusted rate of ever (current) use of electronic cigarettes was 2.1% (0.7%) in junior high school and 3.5% (1.0%) in high school; that of combustible cigarettes was 2.6% (0.6%) in junior high school and 5.1% (1.5%) in high school. The rate of heat-not-burn tobacco use was lower relative to other products: 1.1% (0.5%) in junior high school and 2.2% (0.9%) in high school. An examination of the combined use of the three products identified a high number of dual users. Comparisons between different types of users indicated different backgrounds for combustible cigarette users and new product users. Conclusions: The prevalence of new tobacco-alternative products is growing in popularity among Japanese adolescents. Dual use is common, and many adolescents use new products only. Moreover, e-cigarettes might attract a broader range of groups to smoking. Continuous monitoring and research are needed to investigate their influence as a possible gateway to tobacco smoking

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

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