The Dielectric Properties of Wood IV : On Dielectric Dispersions of Oven-dried Wood

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。In this paper, the dielectric absorptions of oven-dried wood were investigated. There existed three dielectric absorptions in wood. The position of dielectric absorption in high frequency range at low temperature coincided with that of viscoelastic one, and the relaxation process may be associated with the motion of CH_2OH groups in the disordered region of wood substances. The absorption of oven-dried KUSUNOKI appeared in low frequency range at room temperature may be due to the existence of the conductive material and was influenced by the shape of the material in wood. The absorption in very low frequency range at high temperature may be associated with the segmental motion of molecules in the amorphous region accompanied by thermal degradation

<Note>Some Physical Properties of Wood and Cellulose Irradiated with Gamma Rays

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。The effect of gamma irradiation from cobalt-60 on specific gravity, degree of crystallinity, thermal softening temperature, tensile strength and torsional creep behavior of wood and cellulose were investigated and the following results were obtained. 1) A dosage up to about 10^8 rad had little effect on the specific gravity of wood and cellulose. 2) The degree of crystallinity of wood and cellulose remained almost unchanged up to 3×10^7 rad, but started to decrease rapidly at about 1×10^8 rad. 3) The softening temperature of cellulose shifted gradually to a lower temperature region up to about 3×10^7 rad and abruptly in the range exceeding 3×10^7 rad. 4) Strength of wood decreased with increasing irradiation dosage, depending remarkably on loading modes. 5) The value of creep compliance of wood at time 0.1 min did not change up to 1×10^7 rad, but increased markedly in the range exceeding about 3×10^7 rad

Updated meta-analysis of the relation between heart disease and androgenic alopecia or alopecia areata

BackgroundThe relationship between baldness and heart disease is still controversial. We performed an updated meta-analysis of observational studies to evaluate the relation between heart disease and androgenic alopecia or alopecia areata.AimsTo evaluate the relation between heart disease and androgenic alopecia or alopecia areata.Methods Studies were identified by searching Medline and Embase up to October 20, 2017 without language restriction. Meta-analysis was performed by using a random-effects model.Results Nine studies were included in the meta-analysis (eight on androgenic alopecia and one on alopecia areata: 44,806 participants). Compared to men without baldness, men with androgenic alopecia had an increased risk of heart disease (relative risk (RR): 1.32, 95 per cent CI: 1.08 to 1.63, p=0.01, I2=25 per cent), and younger men (< 55 or &le; 60 years) showed a stronger association (RR: 1.44, 95 per cent CI: 1.11 to 1.86, p=0.01, I2=0 per cent). The positive relation depended on the severity of baldness and decreased in order of severe vertex (RR: 1.60, 95 per cent CI: 1.19 to 2.16, p=0.002), moderate vertex (RR: 1.41, 95 per cent CI: 1.22 to 1.64, p < 0.001), mild vertex (RR: 1.18, 95 per cent CI: 1.05 to 1.33, p=0.007), and frontal baldness (RR: 1.10, 95 per cent CI: 0.92 to 1.32, p=0.28)). In contrast, there was no significant relation between alopecia areata and heart disease (RR: 0.91, 95 per cent CI: 0.60 to 1.39, p=0.66).ConclusionAndrogenic alopecia is associated with heart disease, but alopecia areata is not

Direction of collaborative problem solving-based STEM learning by learning analytics approach.

The purpose of this study was to explore the factors that might affect learning performance and collaborative problem solving (CPS) awareness in science, technology, engineering, and mathematics (STEM) education. We collected and analyzed data on important factors in STEM education, including learning strategy and learning behaviors, and examined their interrelationships with learning performance and CPS awareness, respectively. Multiple data sources, including learning tests, questionnaire feedback, and learning logs, were collected and examined following a learning analytics approach. Significant positive correlations were found for the learning behavior of using markers with learning performance and CPS awareness in group discussion, while significant negative correlations were found for some factors of STEM learning strategy and learning behaviors in pre-learning with some factors of CPS awareness. The results imply the importance of an efficient approach to using learning strategies and functional tools in STEM education

Intra-cardiac echocardiography guided catheter ablation of a right posterior accessory pathway in a patient with Ebstein׳s anomaly

AbstractWe report a case of Ebstein׳s anomaly in which radiofrequency catheter ablation of an accessory pathway was successfully performed under intra-cardiac echocardiography. A 50-year-old woman was referred to our hospital for radiofrequency catheter ablation of a paroxysmal supraventricular tachycardia. A 12-lead surface electrocardiogram revealed ventricular pre-excitation associated with type B Wolff–Parkinson–White syndrome. In the baseline electrophysiological study, an orthodromic atrioventricular reciprocating tachycardia with a right posterior accessory pathway was induced. A phased-array intra-cardiac echo probe was positioned in the right atrium to visualize the atrioventricular junction. The key structures for catheter ablation, such as the atrialized right ventricle, atrioventricular junction, and tricuspid valve, were clearly visualized on intra-cardiac echocardiography. Radiofrequency current was successfully delivered at the atrioventricular junction, where a Kent potential was recorded. During a 6-month follow-up period, the patient was free from arrhythmias. The findings in this case suggest that phased-array intra-cardiac echocardiography is useful for ablation of right-sided accessory pathways in patients with Ebstein׳s anomaly

東シナ海の流れ藻に蝟集する稚魚の摂餌生態と海洋環境

Many commercially important fishes associate with drifting seaweeds in their juvenile stage, however, the ecological significance of drifting seaweeds for juvenile fishes is still unclear. We postulated that the following two hypotheses may be applicable for juvenile fishes associate with drifting seaweeds, the “concentration of food supply” hypothesis: juvenile fishes are attracted by phytal animals on the drifting seaweeds and the “indicator-log” hypothesis: fish use accumulations of drifting seaweed as an indicator of productive areas (e.g. frontal areas) for food. We investigated the frontal areas, zooplankton abundance around the drifting seaweed, and the food availability of fish juveniles associated with drifting seaweed accumulations in the East China Sea in 2012 and 2013. A total of 14 drifting seaweed mass and 22 species (n = 408) of fish juveniles were collected. We found that 49.7 - 99.7 % of the individual fed on planktonic food and the feeding incidence on phytal animals was less than 50 %. Although drifting seaweeds were aggregated around the frontal areas of surface currents, the zooplankton abundance was not significantly different between these frontal areas and other areas. Our findings indicate that ecological significance of drifting seaweeds as feeding habit is relatively low for juvenile fishes associated with drifting seaweeds.流れ藻には多くの水産上重要種の稚魚が付随するが，流れ藻の稚魚にとっての生態学的意義は明らかにされていない。筆者らは次の2仮説のいずれかが流れ藻付随稚魚に当てはまると考え，“concentration of food supply hypothesis”（流れ藻葉上生物を摂餌するため）と“indicator log hypothesis”（流れ藻をフロント域のような餌豊度の高い海域の目印とするため）を検証するため，2012年と2013年に東シナ海の流れ藻周辺の海洋環境，フロント域，動物プランクトン豊度，流れ藻付随稚魚の摂餌個体率を調べた。流れ藻は表層流の収束帯に集積されていたが，収束帯のプランクトン豊度は高くなかった。合計14個の流れ藻を採集し，合計22種（408尾）の稚魚の胃内容物を調査した結果，稚魚の49.7 - 99.7 %の個体はプランクトンを選択的に摂餌していたが，葉上生物の摂餌個体率は高くなかった（50 %未満）。以上の結果から流れ藻の稚魚にとっての生態学的意義は摂餌場でないことが示唆された

Visualization of the radiofrequency lesion after pulmonary vein isolation using delayed enhancement magnetic resonance imaging fused with magnetic resonance angiography

AbstractBackgroundThe radiofrequency (RF) lesions for atrial fibrillation (AF) ablation can be visualized by delayed enhancement magnetic resonance imaging (DE-MRI). However, the quality of anatomical information provided by DE-MRI is not adequate due to its spatial resolution. In contrast, magnetic resonance angiography (MRA) provides similar information regarding the left atrium (LA) and pulmonary veins (PVs) as computed tomography angiography. We hypothesized that DE-MRI fused with MRA will compensate for the inadequate image quality provided by DE-MRI.MethodsDE-MRI and MRA were performed in 18 patients who underwent AF ablation (age, 60±9 years; LA diameter, 42±6mm). Two observers independently assessed the DE-MRI and DE-MRI fused with MRA for visualization of the RF lesion (score 0–2; where 0: not visualized and 2: excellent in all 14 segments of the circular RF lesion).ResultsDE-MRI fused with MRA was successfully performed in all patients. The image quality score was significantly higher in DE-MRI fused with MRA compared to DE-MRI alone (observer 1: 22 (18, 25) vs 28 (28, 28), p<0.001; observer 2: 24 (23, 25) vs 28 (28, 28), p<0.001).ConclusionsDE-MRI fused with MRA was superior to DE-MRI for visualization of the RF lesion owing to the precise information on LA and PV anatomy provided by DE-MRI

Polarimetric Imaging of Large Cavity Structures in the Pre-transitional Protoplanetary Disk around PDS 70: Observations of the disk

We present high resolution H-band polarized intensity (PI; FWHM = 0."1: 14 AU) and L'-band imaging data (FWHM = 0."11: 15 AU) of the circumstellar disk around the weak-lined T Tauri star PDS 70 in Centaurus at a radial distance of 28 AU (0."2) up to 210 AU (1."5). In both images, a giant inner gap is clearly resolved for the first time, and the radius of the gap is ~70 AU. Our data show that the geometric center of the disk shifts by ~6 AU toward the minor axis. We confirm that the brown dwarf companion candidate to the north of PDS 70 is a background star based on its proper motion. As a result of SED fitting by Monte Carlo radiative transfer modeling, we infer the existence of an optically thick inner disk at a few AU. Combining our observations and modeling, we classify the disk of PDS 70 as a pre-transitional disk. Furthermore, based on the analysis of L'-band imaging data, we put an upper limit mass of companions at ~30 to ~50MJ within the gap. Taking account of the presence of the large and sharp gap, we suggest that the gap could be formed by dynamical interactions of sub-stellar companions or multiple unseen giant planets in the gap.Comment: accepted by APJ