Radio Frequency Electrical Resistance Measurement under Destructive Pulsed Magnetic Fields

We developed a resistance measurement using radio frequency reflection to investigate the electrical transport characteristics under destructive pulsed magnetic fields above 100 T. A homemade flexible printed circuit for a sample stage reduced the noise caused by the induced voltage from the pulsed magnetic fields, improving the accuracy of the measurements of the reflected waves. From the obtained reflectance data, the absolute value of the magnetoresistance was successfully determined by using a phase analysis with admittance charts. These developments enable more accurate and comprehensive measurements of electrical resistance in pulsed magnetic fields.Comment: 7 pages, 5 figure

Social participation and mortality: does social position in civic groups matter?

BACKGROUND: Social participation is known to predict longevity. However, little is known about the effect of social participation according to an individual's position in civic groups. We evaluated the influence of social position on mortality, using data from a large cohort of Japanese older adults (the AGES cohort). METHODS: Of 14,804 individuals aged 65 years and older enrolled in the AGES, 14,286 individuals were followed up for approximately 5 years from 2003 to 2008. We performed inverse probability of treatment weighted (IPTW) Cox proportional hazards regression with multiple imputation of missing values to compute hazard ratios (HR) for all-cause mortality according to the individual's position in the community organization(s) to which they belonged. We examined participation in the following civic groups: neighborhood association/senior citizen club/fire-fighting team, religious group, political organization or group, industrial or trade association, volunteer group, citizen or consumer group, hobby group, and sports group or club. The values for IPTW were computed based on demographic variables, socioeconomic status, and self-reported medical condition. RESULTS: During 22,718 person-years of follow-up for regular members of community groups and 14,014 person-years of follow-up for participants in leadership positions, 479 deaths and 214 deaths were observed, respectively. Relative to regular members, crude HR for all-cause mortality for occupying leadership positions (e.g. president, manager, or having administrative roles) was 0.72 (95 % CI:0.62-0.85). The IPTW-HR was 0.88 (95 % CI: 0.79-0.99) for participants occupying leadership positions. CONCLUSIONS: Holding leadership positions in community organization(s) may be more beneficial to health than being regular members

Multi-level, cross-sectional study of workplace social capital and smoking among Japanese employees

<p>Abstract</p> <p>Background</p> <p>Social capital is hypothesized to be relevant to health promotion, and the association between community social capital and cigarette smoking has been examined. Individual-level social capital has been found to be associated with smoking cessation, but evidence remains sparse on the contextual effect of social capital and smoking. Further, evidence remains sparse on the association between smoking and social capital in the workplace, where people are spending an increasing portion of their daily lives. We examined the association between workplace social capital and smoking status among Japanese private sector employees.</p> <p>Methods</p> <p>We employed a two-stage stratified random sampling procedure. Of the total of 1,800 subjects in 60 companies, 1,171 (men/women; 834/337) employees (65.1%) were identified from 46 companies in Okayama in 2007. Workplace social capital was assessed in two dimensions; trust and reciprocity. Company-level social capital was based on inquiring about employee perceptions of trust and reciprocity among co-workers, and then aggregating their responses in order to calculate the proportion of workers reporting mistrust and lack of reciprocity. Multilevel logistic regression analysis was conducted using Markov Chain Monte Carlo methods to explore whether individual- and company-level social capital was associated with smoking. Odds ratios (ORs) and 95% credible intervals (CIs) for current smoking were obtained.</p> <p>Results</p> <p>Overall, 33.3% of the subjects smoked currently. There was no relationship between individual-level mistrust of others and smoking status. By contrast, one-standard deviation change in company-level mistrust was associated with higher odds of smoking (OR: 1.25, 95% CI: 1.06-1.46) even after controlling for individual-level mistrust, sex, age, occupation, educational attainment, alcohol use, physical activity, body mass index, and chronic diseases. No clear associations were found between lack of reciprocity and smoking both at the individual- and company-level.</p> <p>Conclusions</p> <p>Company-level mistrust is associated with higher likelihood of smoking among Japanese employees, while individual perceptions of mistrust were not associated. The link between lack of reciprocity and smoking was not supported either at the individual- or company-level. Further studies are warranted to examine the possible link between company-level trust and smoking cessation in the Japanese workplace.</p

Using dynamical mode decomposition to extract the limit cycle dynamics of modulated turbulence in a plasma simulation

The novel technique of dynamical mode decomposition (DMD) is applied to the outputs of a numerical simulation of Kelvin–Helmholtz turbulence in a cylindical plasma, so as to capture and quantify the time evolution of the dominant nonlinear structures. Empirically, these structures comprise rotationally symmetric deformations together with spiral patterns, and they are found to be identified as the main modes of the DMD. A new method to calculate the time evolution of DMD mode amplitudes is proposed, based on convolution-type correlation integrals, and then applied to the simulation outputs in a limit cycle regime. The resulting time traces capture the essential physics far better than Fourier techniques applied to the same data

Evidence for TeV gamma-ray emission from the shell type SNR RXJ1713.7-3946

We report the results of TeV gamma-ray observations of the shell type SNR RXJ1713.7-3946 (G347.3-0.5). The discovery of strong non-thermal X-ray emission from the northwest part of the remnant strongly suggests the existence of electrons with energies up to 100 TeV in the remnant, making the SNR a good candidate TeV gamma-ray source. We observed RXJ1713.7-3946 from May to August 1998 with the CANGAROO 3.8m atmospheric imaging Cerenkov telescope and obtained evidence for TeV gamma-ray emission from the NW rim of the remnant with the significance of 5.6 sigma. The observed TeV gamma-ray flux from the NW rim region was estimated to be (5.3 +/- 0.9[statistical] +/- 1.6[systematic]) * 10^{-12} photons cm^{-2} s^{-1} at energies >= 1.8 +/- 0.9 TeV. The data indicate that the emitting region is much broader than the point spread function of our telescope. The extent of the emission is consistent with that of hard X-rays observed by ASCA. This TeV gamma-ray emission can be attributed to the Inverse Compton scattering of the Cosmic Microwave Background Radiation by shock accelerated ultra-relativistic electrons. Under this assumption, a rather low magnetic field of 11 micro gauss is deduced for the remnant from our observation.Comment: Accepted for publication by Astronomy and Astrophysics (5 pages, 2 figures