Yokohama College of Commerce

The purpose of this study was to compare roller skiing economy during different training phases in Nordic combined (NC) athletes and determine the aerobic and anaerobic factors responsible for changes in skiing economy. Seven elite NC athletes underwent incremental load tests on a large buried treadmill in both spring and autumn using roller skis. Measurements included oxygen uptake, respiratory exchange ratio, and blood lactate concentration. Roller skiing economy was calculated from aerobic and anaerobic energy system contributions, and overall roller skiing economy was determined by combining the two. Comparisons were made between the skiing economies obtained in the two measurement sessions. Physical characteristics and incremental test performance remained consistent between the two measurement sessions. The overall skiing economy at each speed significantly improved toward the competition season (p < 0.05). Similarly, the contribution of anaerobic energy system at each speed showed significant improvement (p < 0.05). In contrast, the contribution of aerobic energy system did not change between the two measurement sessions. This study reveals that NC athletes enhance their skiing economy at the same speed during submaximal efforts in preparation for the competition season. This improvement is predominantly associated with an improvement in the contribution of anaerobic energy system.

article: Hormone and oxidative stress response during recovery on normoxia after hypoxic resistance exercise - Gazzetta Medica Italiana - Archivio per le Scienze Mediche 2022 June;181(6):432-8 - Minerva Medica - Journals

This study’s purpose was to clarify methods of effectively promoting student engagement within higher education classes in Japan. To that end, a qualitative survey was performed of university students, based on the concept of learning experience (LX) levels. Via textual analyses of collected data, respective factors were extracted that affect the increase, decline, and stagnation of learning-experience levels. Then, differences between these factors were verified. Consequently, the following were found to have positive effects on increasing learning experience levels: interesting subject, value recognition, sense of progress in learning, clarity of attended classes, class format, and relatedness to the future. Moreover, the following were suggested as positively affecting a decrease of LX level: decline of interest/motivation regarding the subject and the study circumstances of other classes. Also observed as contributing to the stagnation of LX level were a decline of interest/motivation around the subject and study circumstances in other classes.

Kinematic parameters during throwing were analyzed to examine whether the absence of run-up before ball release or ball graspability was associated with ball velocity acquisition process in 33 participants. Three-dimensional coordinates were measured using a motion analysis system with eight infrared cameras with a sampling rate of 250 Hz. The captured motion data were computed to calculate the kinematic parameters. Path analysis, a structural equation modeling technique, was applied to the obtained kinematic parameters to clarify the "strength" and "direction" of the interrelationship among the observed parameters because it can detect the relationship of each parameter in the complicated theoretical model. When throwing small graspable softballs "without" run-up, the velocity of the center of the body mass influenced the ball velocity. However, in that case, a greater backward trunk tilt with a longer acceleration distance is necessary to acquire greater ball velocity. When throwing large non-graspable dodgeballs with and without run-up and/or throwing small graspable softballs "with" run-up, the horizontal velocity of the thrower's center of the body mass positively affected the ball velocity via pull distance due to the acceleration distance of the ball and increased step length. The non-graspable dodgeball accelerated with a shorter pull distance in the lateral direction, and the presence or absence of run-up did not affect the ball velocity acquisition process in non-graspable ball throwing.

Abstract Sargassum forests play an important role in coastal waters as habitats for marine organisms, including commercial species. However, human activities have negatively affected their distribution causing a worldwide decline of Sargassum forests. Mapping and monitoring the distribution and biomass of these habitats using acoustic remote sensing techniques is key for their conservation. Nonetheless, most researches based on acoustic remote sensing methods focus on estimations of macrophyte area and its canopy height, and less researches reporting 3D visualization of these habitats. This study demonstrates the use of high-resolution multibeam echosounder (MBES) bathymetric data to visualize the 3D structure of Sargassum forests. Comparing acoustic data and underwater camera photos collected in field surveys, we identified Sargassum individuals as vertical clusters of contiguous sounding points with a base close to the sea bottom in the sounding data of the MBES. Using this criterion, we could distinguish Sargassum echoes, visualize the 3D structure of Sargassum forests and estimate the number of Sargassum individuals in the survey area. Using the relation between thallus length and dry weight of sampled Sargassum plants, standing stock and biomass could be estimated assuming the thallus length was the height of Sargassum plants identified with the MBES.

In this paper, we deal with the problem of database statistics publishing with privacy and utility guarantees. While various privacy and utility metrics have been proposed, purposes of using the statistics for a user and an adversary and their background knowledge about the database have not been specified. We model the user and the adversary from two perspectives. First, we model their background knowledge: knowledge of statistics of the database and knowledge of distribution for the database. Then we model the purposes of them as decision functions in statistical decision theory. Privacy and utility metrics are defined based on risk functions. Comparison of the statistical decision-theoretic framework we propose and differential privacy framework is made through a numerical example.

Book ReviewForeign Language Education in Japan: Exploring Qualitative Approaches, Sachiko Horiguchi, Yuki Imoto, and Gregory S. Poole (Eds.) (2015). Rotterdam: Sense Publishers, 191 pages, Paperback €45.20 ISBN: 978-94-6300-323-0 (paperback)