485 research outputs found

    Stellar Parameters and Elemental Abundances of Late-G Giants

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    The properties of 322 intermediate-mass late-G giants (comprising 10 planet-host stars) selected as the targets of Okayama Planet Search Program, many of which are red-clump giants, were comprehensively investigated by establishing their various stellar parameters (atmospheric parameters including turbulent velocity fields, metallicity, luminosity, mass, age, projected rotational velocity, etc.), and their photospheric chemical abundances for 17 elements, in order to study their mutual dependence, connection with the existence of planets, and possible evolution-related characteristics. The metallicity distribution of planet-host giants was found to be almost the same as that of non-planet-host giants, making marked contrast to the case of planet-host dwarfs tending to be metal-rich. Generally, the metallicities of these comparatively young (typical age of ~10^9 yr) giants tend to be somewhat lower than those of dwarfs at the same age, and super-metal-rich ([Fe/H] > 0.2) giants appear to be lacking. Apparent correlations were found between the abundances of C, O, and Na, suggesting that the surface compositions of these elements have undergone appreciable changes due to dredge-up of H-burning products by evolution-induced deep envelope mixing which becomes more efficient for higher-mass stars.Comment: Accepted for publication in PASJ (21 pages, 15 figures) (wrong URL of e-tables in Ver.1 has been corrected in Ver.2

    Error control on mobile station sides in collaborative multiple-input multiple-output systems

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    Collaboration between mobile stations (MSs) may lead to a new form of wireless communication. Collaboration on MS sides considerably improves signal detection performance, especially for multiple-input multiple-output (MIMO) transmission systems. In this study, a novel detector collaboration system is proposed to reduce the traffic volume on inter-MS collaboration links. Multiple MSs in the immediate vicinity are used to collaboratively decode the MIMO signals received from a base station. Furthermore, we consider a distributed detection system, in which multiple detection MSs decode the MIMO signals independently. Multiple decision results are exploited to improve the error performance. Residual interference coefficients were used to finalize the decision results. The error ratio performance and the traffic volume over collaboration wireless links were compared with those of two combining schemes through computer simulations and field experiments. The results revealed that the proposed error control scheme on mobile station sides offers a better tradeoff between the error performance and the traffic volume on the collaboration wireless links

    Ο Βιβλιοθηκονόμος - Επιστήμονας Πληροφόρησης

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    Resolution of pulmonary multiplanar reconstruction images from 0.5-mm theoretical isotropic data: a fundamental study using an inflated and fixed lung specimen.

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    The aim of the present study was to define the resolution of multiplanar reconstruction (MPR) of the lung from &#34;theoretical isotropic data.&#34; Using inflated and fixed lung specimens of the pig placed in the chest wall phantom, 0.5-mm isotropic data were obtained with 2 different helical pitches: 1:7 (high-quality mode) or 1:13, (high-speed mode), and 2 different tube currents: 250 mAs (high-tube-current mode) or 100 mAs (low-tube-current mode), with or without overlapping reconstruction. MPRs were created from these axial data. The diameter of the smallest visible pulmonary artery and bronchi of these CT images were measured on the corresponding slices of the specimen. The high-speed and low-tube-current mode significantly degraded the image quality due to increased noise. The smallest visible pulmonary artery and bronchus resolved on MPRs from axial-spiral data with 0.5-mm collimation were approximately 100 micrometer and 1,000 micrometer in diameter, respectively. In conclusion, helical pitch and tube current influence the resolution of MPR of the lung.</p

    Near-infrared long persistent luminescence of Er3+ in garnet for the third bio-imaging window

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    生体透過率の高い波長で長時間光り続ける蛍光体の開発に成功 --光源を必要としない近赤外域での生体分子可視化に--. 京都大学プレスリリース. 2016-11-29

    Male Pheromones Induce Ovulation in Female Honeycomb Groupers (Epinephelus merra): A Comprehensive Study of Spawning Aggregation Behavior and Ovarian Development

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    This study characterizes the spawning phenomena of the honeycomb grouper (Epinephelus merra), which is a lunar-synchronized spawner that spawns a few days after full moon. To elucidate the aggregation characteristics of wild honeycomb groupers, the numbers of males and females at the spawning grounds were counted before and after the full moon. Approximately 20 males were consistently observed at the spawning grounds throughout the study period. Females appeared several days after full moon and rapidly increased in number, peaking four days after full moon (41 individuals). The maturation status of the females aggregating at the spawning grounds was investigated. The gonadosomatic index increased rapidly three days after full moon, and ovulation was confirmed. Individuals with ovulatory eggs were present for three days, after which the number of females at the spawning grounds decreased. Additionally, the role of males in final oocyte maturation (FOM) and ovulation in females during the spawning phase was investigated in captivity. FOM was induced in females reared in water with mature males, suggesting that male pheromones in the water induced FOM via activation of the hypothalamic–pituitary–gonadal axis. This suggests that spawning at the natural spawning grounds was the result of male–female interactions via pheromones

    Association between Oral Health Status and Diabetic Nephropathy-Related Indices in Japanese Middle-Aged Men

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    Oral health status is known to be associated with lifestyle-related diseases such as diabetes and chronic kidney disease. In Japan, around 40% of hemodialysis cases are patients with diabetic nephropathy. The aim of this study was to clarify the association between oral health status and diabetic nephropathy-related indices in Japanese middle-aged men. Sixty-six men (age range: 55–64 years) with ≥20 remaining teeth and who received public medical checkups and oral examinations were enrolled. We examined correlations of age, body mass index, HbA1c, HDL-C, LDL-C, neutral fat, serum creatinine, and the estimated glomerular filtration rate (eGFR) with the number of remaining teeth or the community periodontal index (CPI) score (periodontal pocket < 4mm: 0, 4–6 mm: 1, ≥6 mm: 2). A positive correlation between the CPI score and serum creatinine and a negative correlation between CPI score and eGFR (Spearman’s rank correlation coefficient, r = 0.459, p < 0.01, and r = −0.460, p < 0.01, respectively) were observed. The mean eGFR in the CPI score 0 group was significantly higher than that in the CPI score 1/2 group (82.6 vs. 70.7, Student’s t-test, p < 0.01). Logistic regression analysis using eGFR as a dependent variable and age, CPI score, body mass index, HbA1c, and neutral fat as independent variables suggested that low eGFR (<60) could be attributed to CPI score (OR = 3.169, 95% CI: 1.031–9.742, p = 0.044). These results suggest a possible association between periodontal status and renal function in Japanese middle-aged men. Periodontal condition is controlled by oral prophylaxis, and periodontal disease and chronic kidney disease have some common risk factors. Thus, periodontal management can contribute to the prevention of severe chronic kidney disease
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