Oxygen Isotope Exchange Between Molten Silicate Spherules and Ambient Water Vapor with Nonzero Relative Velocity: Implication for Chondrule Formation Environment

Oxygen isotope compositions of chondrules reflect the environment of chondrule formation and its spatial and temporal variations. Here, we present a theoretical model of oxygen isotope exchange reaction between molten silicate spherules and ambient water vapor with finite relative velocity. We found a new phenomenon, that is, mass-dependent fractionation caused by isotope exchange with ambient vapor moving with nonzero relative velocity. We also discussed the plausible condition for chondrule formation from the point of view of oxygen isotope compositions. Our findings indicate that the relative velocity between chondrules and ambient vapor would be lower than several 100 m/s when chondrules crystallized.Comment: 15 pages, 8 figures. Accepted for publication in Icaru

Robotic Fish Technology and Its Applications to Space Mechatronics

The authors have developed a shark ray robotic fish based on biomimetic approaches. The paper describes the newly developed robotic fish technology and its application to mechatronics in the space. It is found that robotic fish technology creates not only new underwater robotics, but also the next generation space mechatronics for geological survey of lunar/planets and dust cleaning in the space station.2013 the 3rd International Conference on Mechatronics and Applied Mechanics (ICMAM2013), Dec.27-28, 2013 Paris, Franc

The ability to appropriately distinguish throws for different target positions

Repeated and accurate throwing of an object to a target position is a special human motor skill. It is particularly important to understand accuracy, which has received less attention than speed due to difficulties in measurement. Accuracy has been studied in terms of reducing errors against a single target, but also in terms of distinguishing appropriate throws for targets in different positions. In this study, this ability was investigated by evaluating the two-dimensional distributions of the pitch locations of 15 pitches to three target positions in university students with and without baseball experience. The center, major and minor axis length, major and minor axis ratio, slope, area, and percentage of overlapping area of the 95% confidence ellipse were compared between target positions and participants using a two-way repeated-measures analysis of variance (ANOVA). The center and area of the ellipse indicate the mean and variability of the error, respectively. The lengths of the major axes correspond to the variability of the release timing, and the minor axes correspond to the variability of the release point in space. Therefore, the ratio of the major and minor axes indicates how the variability of the pitching motion is controlled. The slope of the ellipse corresponds to the throwing arm's trajectory, and the percentage of overlap area means the ability to distinguish throws at different target positions. The result showed a main effect of participants on all indices except the center of the ellipse. This indicates that participants can generally distinguish throws by target positions regardless of their baseball experience, although participants with baseball experience may naturally reduce variability. Furthermore, participants with baseball experience demonstrated a decrease variability in release timing, which is a primary contributor to the pitch location variability, relative to the spatial variability of the pitching movements. This reduction in timing variability may be attributed to advanced motor control mechanisms

ATF6β is a host cellular target of the Toxoplasma gondii virulence factor ROP18

Toxoplasma virulence factor ROP18 targets endoplasmic reticulum–bound transcription factor ATF6β in the host cell, leading to the detrimental loss of ATF6β through proteasome-dependent degradation

Clinical and laboratory predictors for plaque erosion in patients with acute coronary syndromes

Background-—Plaque erosion is responsible for 25% to 40% of patients with acute coronary syndromes (ACS). Recent studies suggest that anti-thrombotic therapy without stenting may be an option for this subset of patients. Currently, however, an invasive procedure is required to make a diagnosis of plaque erosion. The aim of this study was to identify clinical or laboratory predictors of plaque erosion in patients with ACS to enable a diagnosis of erosion without additional invasive procedures. Methods and Results-—Patients with ACS who underwent optical coherence tomography imaging were selected from 11 institutions in 6 countries. The patients were classified into plaque rupture, plaque erosion, or calcified plaque, and predictors were identified using multivariable logistic modeling. Among 1241 patients with ACS, 477 (38.4%) patients were found to have plaque erosion. Plaque erosion was more frequent in non–ST-segment elevation-ACS than in ST-segment–elevation myocardial infarction (47.9% versus 29.8%, P=0.0002). Multivariable logistic regression models showed 5 independent parameters associated with plaque erosion: age 15.0 g/dL, and normal renal function. When all 5 parameters are present in a patient with non–ST-segment elevation-ACS, the probability of plaque erosion increased to 73.1%. Conclusions-—Clinical and laboratory parameters associatedwith plaque erosion are explored in this retrospective registry study. These parametersmay be useful to identify the subset ofACS patients with plaque erosion and guide themto conservativemanagement without invasive procedures. The results of this exploratory analysis need to be confirmed in large scale prospective clinical studiesDr. Jang has received an educational grant from Abbott Vascular and Medicure. Dr. Adriaenssens has received grants and consulting fees from Abbott Vascula

老朽化吹付け法面の弾性波探査によるモニタリングの適用性

国道42号の同一法面を対象に各種の物理探査手法を使用した実証実験の中から，弾性波探査を用いた法面調査結果を報告し，弾性波探査手法の法面健全性評価への適用性について検討したものである