Designing Dirac points in two-dimensional lattices

We present a framework to elucidate the existence of accidental contacts of energy bands, particularly those called Dirac points which are the point contacts with linear energy dispersions in their vicinity. A generalized von-Neumann-Wigner theorem we propose here gives the number of constraints on the lattice necessary to have contacts without fine tuning of lattice parameters. By counting this number, one could quest for the candidate of Dirac systems without solving the secular equation. The constraints can be provided by any kinds of symmetry present in the system. The theory also enables the analytical determination of k-point having accidental contact by selectively picking up only the degenerate solution of the secular equation. By using these frameworks, we demonstrate that the Dirac points are feasible in various two-dimensional lattices, e.g. the anisotropic Kagome lattice under inversion symmetry is found to have contacts over the whole lattice parameter space. Spin-dependent cases, such as the spin-density-wave state in LaOFeAs with reflection symmetry, are also dealt with in the present scheme.Comment: 15pages, 9figures (accepted to Phys. Rev. B

Development of Track Condition Monitoring System Using Onboard Sensing Device

Monitoring the conditions of railway tracks is essential for ensuring the railway safety. In-service vehicles equipped with sensors and GPS systems can act as probes to detect and analyse real-time vehicle vibration. Recently, a compact on-board sensing device has been developed. This chapter describes the track condition monitoring system that uses a compact on-board sensing device and diagnosis software. The diagnosis software provides the function of detecting track faults using the root mean square (RMS) of the car-body acceleration. It also allows analysis in the time-frequency domain using wavelet transform. A monitoring experiment in a local railway line showed that the system is effective for practical application

Unusual Carbonaceous Dust Distribution in PN G095.2+00.7

We investigate the polycyclic aromatic hydrocarbon features in the young Galactic planetary nebula PN G095.2+00.7 based on mid-infrared observations. The near- to mid-infrared spectra obtained with the AKARI/IRC and the Spitzer/IRS show the PAH features as well as the broad emission feature at 12 {\mu}m usually seen in proto-planetary nebulae (pPNe). The spatially resolved spectra obtained with Subaru/COMICS suggest that the broad emission around 12 {\mu}m is distributed in a shell-like structure, but the unidentified infrared band at 11.3 {\mu}m is selectively enhanced at the southern part of the nebula. The variation can be explained by a difference in the amount of the UV radiation to excite PAHs, and does not necessarily require the chemical processing of dust grains and PAHs. It suggests that the UV self-extinction is important to understand the mid-infrared spectral features. We propose a mechanism which accounts for the evolutionary sequence of the mid-infrared dust features seen in a transition from pPNe to PNe.Comment: 6 pages, 4 figure

Detection of Gamma-Ray Polarization in Prompt Emission of GRB 100826A

We report the polarization measurement in prompt $\gamma$-ray emission of GRB 100826A with the Gamma-Ray Burst Polarimeter (GAP) aboard the small solar power sail demonstrator IKAROS. We detected the firm change of polarization angle (PA) during the prompt emission with 99.9% ($3.5 \sigma$) confidence level, and the average polarization degree ($\Pi$) of $27 \pm 11$% with 99.4% ($2.9 \sigma$) confidence level. Here the quoted errors are given at 1 $\sigma$ confidence level for two parameters of interest. The systematic errors have been carefully included in this analysis, unlike any previous reports. Such a high $\Pi$ can be obtained in several emission models of gamma-ray bursts (GRBs), including synchrotron and photospheric models. However, it is difficult to explain the observed significant change of PA within the framework of axisymmetric jet as considered in many theoretical works. The non-axisymmetric (e.g., patchy) structures of the magnetic fields and/or brightness inside the relativistic jet are therefore required within the observable angular scale of $\sim \Gamma^{-1}$. Our observation strongly indicates that the polarization measurement is a powerful tool to constrain the GRB production mechanism, and more theoretical works are needed to discuss the data in more details.Comment: 6 pages, 3 figures, accepted for publication in ApJ

Mobilization of Volunteers and Usage of ICT by Environmental Citizen Groups in Japan

It has been said that the spread of social networking services (SNSs) has changed the style of social movements. One of these changes has involved gathering participants, and has been called “the revolution of mobilization.” However, the membership of many Japanese environmental movements are aging and decreasing in number. They are faced with a labor shortage, so how far is “the revolution of mobilization” progressing? This study examines how environmental citizen groups in Japan are using information and communications technology (ICT) to expand their membership and how ICT is changing citizen movements. We interviewed six nationwide environmental citizen groups, three local environmental citizen groups, three nationwide intermediate support organizations, and three local intermediate support organizations. Since these environmental citizen groups possess minimum manpower required to sustain their activities, though they are prepared to use ICT, they are unable to organize, strengthen, or expand. Although the aging membership and shortage of staff are recognized as a big problem, they are unable to solve these problems fully. Although new movements are born from younger generations and big cities, the existing groups have not sufficiently engaged with ICT to develop their movement. In the present situation, existing groups cannot avoid the reduction and aging of their membership, and their activities may decline. Filling the generational gap and regional gap in citizen movements therefore remains a problem.本研究の遂行にあたっては科研費助成金（基盤研究C：25350440：ボランティア参加の機構解明とそれを活用したボランティア獲得の為の情報システム開発：代表前田恭伸）を受けている

Mobilization of Volunteers and Usage of ICT by Environmental Citizen Groups in Japan

It has been said that the spread of social networking services (SNSs) has changed the style of social movements. One of these changes has involved gathering participants, and has been called “the revolution of mobilization.” However, the membership of many Japanese environmental movements are aging and decreasing in number. They are faced with a labor shortage, so how far is “the revolution of mobilization” progressing? This study examines how environmental citizen groups in Japan are using information and communications technology (ICT) to expand their membership and how ICT is changing citizen movements. We interviewed six nationwide environmental citizen groups, three local environmental citizen groups, three nationwide intermediate support organizations, and three local intermediate support organizations. Since these environmental citizen groups possess minimum manpower required to sustain their activities, though they are prepared to use ICT, they are unable to organize, strengthen, or expand. Although the aging membership and shortage of staff are recognized as a big problem, they are unable to solve these problems fully. Although new movements are born from younger generations and big cities, the existing groups have not sufficiently engaged with ICT to develop their movement. In the present situation, existing groups cannot avoid the reduction and aging of their membership, and their activities may decline. Filling the generational gap and regional gap in citizen movements therefore remains a problem.本研究の遂行にあたっては科研費助成金（基盤研究C：25350440：ボランティア参加の機構解明とそれを活用したボランティア獲得の為の情報システム開発：代表前田恭伸）を受けている

Broader autism phenotype as a risk factor for postpartum depression: Hamamatsu Birth Cohort (HBC) Study

AbstractThe broader autism phenotype (BAP), which refers to the expression of behavioral and cognitive propensities that are milder but qualitatively similar to those defining autism spectrum disorder, can play a crucial role in postpartum depression (PPD). We investigated whether pregnant women's BAP would increase the risk for PPD, using a representative birth cohort in Japan. Pregnant women were enrolled in the Hamamatsu Birth Cohort (HBC) Study during their mid-gestation (N=841) and were followed up until 3 months after delivery. BAP was measured mainly during the 2nd trimester of the pregnancy by using the Broader Phenotype Autism Symptoms Scale. Participants scoring 9 points or higher on the Edinburgh Postnatal Depression Scale at least once during the first 3 months after childbirth were diagnosed with PPD. Among participants, 128 (15.2%) women were found to have PPD. Multiple logistic regression analyses showed that BAP were associated with PPD (OR=1.19, 95% CI [1.07–1.31]), even after controlling for other potential confounders. In addition, the association was not moderated by history of depression and/or anxiety disorders, including concurrent depressive and anxiety symptoms during pregnancy. The findings suggest that pregnant women with BAP have an elevated risk for PPD

Deficiency of the RIβ subunit of protein kinase A causes body tremor and impaired fear conditioning memory in rats

The RIβ subunit of cAMP-dependent protein kinase (PKA), encoded by Prkar1b, is a neuronal isoform of the type I regulatory subunit of PKA. Mice lacking the RIβ subunit exhibit normal long-term potentiation (LTP) in the Schaffer collateral pathway of the hippocampus and normal behavior in the open-field and fear conditioning tests. Here, we combined genetic, electrophysiological, and behavioral approaches to demonstrate that the RIβ subunit was involved in body tremor, LTP in the Schaffer collateral pathway, and fear conditioning memory in rats. Genetic analysis of WTC-furue, a mutant strain with spontaneous tremors, revealed a deletion in the Prkar1b gene of the WTC-furue genome. Prkar1b-deficient rats created by the CRISPR/Cas9 system exhibited body tremor. Hippocampal slices from mutant rats showed deficient LTP in the Schaffer collateral–CA1 synapse. Mutant rats also exhibited decreased freezing time following contextual and cued fear conditioning, as well as increased exploratory behavior in the open field. These findings indicate the roles of the RIβ subunit in tremor pathogenesis and contextual and cued fear memory, and suggest that the hippocampal and amygdala roles of this subunit differ between mice and rats and that rats are therefore beneficial for exploring RIβ function