Recombination kinetics of a dense electron-hole plasma in strontium titanate

We investigated the nanosecond-scale time decay of the blue-green light emitted by nominally pure SrTiO$_3$ following the absorption of an intense picosecond laser pulse generating a high density of electron-hole pairs. Two independent components are identified in the fluorescence signal that show a different dynamics with varying excitation intensity, and which can be respectively modeled as a bimolecular and unimolecolar process. An interpretation of the observed recombination kinetics in terms of interacting electron and hole polarons is proposed

Photogenerated Carriers in SrTiO3 Probed by Mid-Infrared Absorption

Infrared absorption spectra of SrTiO$_3$ have been measured under above-band-gap photoexcitations to study the properties of photogenerated carriers, which should play important roles in previously reported photoinduced phenomena in SrTiO$_3$. A broad absorption band appears over the entire mid-infrared region under photoexcitation. Detailed energy, temperature, and excitation power dependences of the photoinduced absorption are reported. This photo-induced absorption is attributed to the intragap excitations of the photogenerated carriers. The data show the existence of a high density of in-gap states for the photocarriers, which extends over a wide energy range starting from the conduction and valence band edges.Comment: 5 pages, 5 figures, submitted to J. Phys. Soc. Jp

Pilophorus from Thailand.

18 p. : ill. (some col.) ; 26 cm.Morphologically novel species of the ant-mimetic plant bug genus Pilophorus Hahn from Thailand are reviewed, with photographic images of live individuals. Three species, Pilophorus barbiger, P. giraffoides, and P. portentosus, are described as new, in addition to two known Thai species, P. maculatus (Schuh) and P. pleiku (Schuh), which are also diagnosed. The female of P. pleiku is reported for the first time. The biology and immature forms are documented for P. pleiku and P. barbiger, which were observed to be associated with ants on the rubiaceous broadleaf, Gardenia sootepensis Hutch. The systematic position of such morphologically novel species is discussed. Pilophorus palawanus (Schuh) is newly recorded from Singapore

Optically tuned dimensionality crossover in photocarrier-doped SrTiO3_3: onset of weak localization

We report magnetotransport properties of photogenerated electrons in undoped SrTiO$_3$ single crystals under ultraviolet illumination down to 2 K. By tuning the light intensity, the steady state carrier density can be controlled, while tuning the wavelength controls the effective electronic thickness by modulating the optical penetration depth. At short wavelengths, when the sheet conductance is close to the two-dimensional Mott minimum conductivity we have observed critical behavior characteristic of weak localization. Negative magnetoresistance at low magnetic field is highly anisotropic, indicating quasi-two-dimensional electronic transport. The high mobility of photogenerated electrons in SrTiO$_3$ allows continuous tuning of the effective electronic dimensionality by photoexcitation.Comment: 7 pages, 7 figure

Physical activity environment and Japanese adults’ body mass index

Evidence about the impacts of the physical activity environment on adults’ weight in the context of Asian countries is scarce. Likewise, no study exists in Asia examining whether Walk Score®—a free online walkability tool—is related to obesity. This study aimed to examine associations between multiple physical activity environment measures and Walk Score® ratings with Japanese adults’ body mass index (BMI). Data from 1073 adults in the Healthy Built Environment in Japan study were used. In 2011, participants reported their height and weight. Environmental attributes, including population density, intersection density, density of physical activity facilities, access to public transportation, and availability of sidewalks, were calculated using Geographic Information Systems. Walk Scores® ratings were obtained from the website. Multiple linear regression analysis was conducted to examine the association between each environmental attribute and BMI. Adjusting for covariates, all physical activity environmental attributes were negatively associated with BMI. Similarly, an increase of one standard deviation of Walk Score® was associated with a 0.29 (95% confidence interval (CI) of –0.49-–0.09) decrease in BMI. An activity-friendly built environment was associated with lower adults’ BMI in Japan. Investing in healthy community design may positively impact weight status in non-Western context

Willingness to pay for municipality hospital services in rural Japan: a contingent valuation study

<p>Abstract</p> <p>Background</p> <p>The Japanese healthcare system has undergone reforms to address the struggles that municipality hospitals face. Reform guidelines clearly define criteria for administrative improvement. However, criteria to evaluate the demand for healthcare provisions in rural Japan, including the needs of rural residents for municipality hospitals in particular have not been specified. The purpose of this paper is to measure residents' willingness to pay (WTP) for municipality hospital services using the contingent valuation method, and to evaluate municipality hospital valuation on the basis of WTP. K town, located in the Hokkaido prefecture of Japan, was selected as the location for this study. Participants were recruited by a town hall healthcare administrator, hospital and clinic staff, and a local dentist. Participants were asked what amount they would be willing to pay as taxes to continue accessing the services of the municipality hospital for one year by using open-ended questions in face-to-face interviews.</p> <p>Findings</p> <p>Forty-eight residents were initially recruited, and 40 participants were selected for the study (response rate 83%). As compared to K town's population, this data slanted toward the elderly, although there was no significant difference in frequency among the characteristics. The median WTP was estimated at 39,484 yen ($438.71), with a 95$308.95-615.96). Logistic regression revealed no significant factors affecting WTP.</p> <p>Conclusions</p> <p>If the total amount of residents' WTP for the municipality hospital were to be estimated by this result, it would calculate with 129,586,000 yen ($1,439,844). This is approximately equal to the amount of money to be transferred from the general account of the government of K town, more than one-half of the town tax of K town, and about two-fold in comparison to Japan as a whole. This showed that K town's residents placed a high valuation on the municipality hospital, which nearly equalled the amount that the K town government provided to the municipality hospital to cover its annual deficit. K town residents had come to expect not only general clinical practice, but also emergency medical services and night practice provided by their own town's municipality hospital. WTP can be used as a measure of hospital evaluation because it reflects the importance of the hospital to the residents in its region.</p