Akita Prefectural University

About: Akita Prefectural University is a education organization based out in Akita, Japan. It is known for research contribution in the topics: Magnetic field & Starch. The organization has 1631 authors who have published 3107 publications receiving 45764 citations. The organization is also known as: Akita kenritsu daigaku.

Short-term changes affecting regeneration of Fagus crenata after the simultaneous death of Sasa kurilensis

Abstract: Question: The aim of the present study is to determine whether seed/seedling predation will increase and Fagus survival will decline with the recovery of the Sasa cover. Methods: We examined Fagus crenata regeneration for seven years in an old-growth Fagus-Sasa forest near Lake Towada, northern Japan, by examining the effects of simultaneous death of Sasa, tree canopy gap formation, mast seeding of Fagus and seed and seedling predation by rodents on the survival of Fagus seeds and current year seedlings. We established four types of sites differing in forest canopy (closed or gap) and Sasa status (dead or alive) following the simultaneous flowering and death of Sasa kurilensis (dwarf bamboo) in 1995. Results: Fallen Fagus seed was abundant in 1997 and 2000 (mast years). In sites with alive Sasa, survival from the first growing season was low due to high seed and seedling predation. In sites with dead Sasa, seed survival under the canopy was high for both mast years, but in gaps it varied between years. Seedling survival was highest in canopy gaps with dead Sasa (gap-dead) in 1998, because of higher light levels and lower predation by rodents. However, seedling survival in these plots was low in 2001, apparently because rapid Sasa recovery favoured rodent predation. In both mast years, Sasa die-back had significant positive effects on seed and seedling survival under closed canopies because the seedlings there were more successful in escaping predation. Conclusion: The change in successful sites for the early stage of regeneration of Fagus appears to reflect the combined effects of canopy gap, seed/seedling predation and revegetation of Sasa.

A tubular piezoelectric vibrator gyroscope

Abstract: This paper proposes a vibrator gyroscope made of a piezoelectric tube, which has the same configuration as that used for the tri-axial sensors and actuators developed in our previous paper. The gyroscopic operation is the same as a circular rod, but the polarization (in thickness direction of the shell) and, accordingly, the electrode arrangement are much simpler. Wireless LAN arrangement is devised for remote data access with which the measurement is possible for the gyroscope under rotation. The experimental results are compared with the numerical simulation with three-dimensional finite-element calculation. The discrepancy between the measured and the experimental is found to depend on the asymmetrical deformation of the structure, and the cause is clearly demonstrated via simulation. This shows the usefulness of the numerical modeling to investigate the cause, in which the parameters of dimensions and boundary conditions can easily change.

The International Long-Term Ecological Research–East Asia–Pacific Regional Network (ILTER-EAP): history, development, and perspectives

Abstract: There are growing needs to broaden and deepen our multi-faceted understanding of the ecosystems, and the networks of Long-Term Ecological Research (LTER) can play significant roles in fostering and applying ecosystem studies at regional and global scales. The International LTER Network (ILTER) is organized as a global network of field research sites and scientists to address current ecological issues such as biodiversity loss and ecosystem degradation within a globally changing environment. The ILTER East Asia–Pacific Regional Network (ILTER-EAP) is one of the four constituent ILTER regional networks. Since 1995, ILTER-EAP has been developed to promote data sharing, research collaborations and capability building in the science and to bridge gaps between societal needs and scientific imperatives on concerns in the Asia–Pacific Region. Currently, ILTER-EAP comprises nine formal ILTER members and two associate networks. Their activities involve long-term and multiple-site observations of structural, functional and developmental aspects of ecosystems, data sharing, and bridging society and ecological science. This paper presents a review of the activities of ILTER-EAP, focusing on its: (1) vision and the development following its inception, (2) scientific activities and major outputs related to selected thematic areas, (3) contributions from ILTER-EAP to the international initiatives, and (4) future challenges and opportunities relating to its development and role in facilitating regional and global research collaborations. Accordingly, regional research questions were identified that could be most effectively addressed by opening up a common research platform, integrated data management system and the network science, which is open to all interested parties.

Comparison of the effects of verbal versus visual information about sound sources on the perception of environmental sounds

Abstract: We perceive our environment by integrating multi-modal information. Although researchers have attempted to interpret sound perception solely through hearing, few attempts have been made using multi-modal information to understand our perception of environmental sounds. In this study, we conducted three experiments in which the sound stimuli were presented alone, with corresponding verbal information, or with corresponding visual information. In order to investigate the difference in the perception attributable to the verbal and visual information, analysis of variance was applied to the factor scores of each stimulus. Our analyses revealed that the effects of additional information on factor scores were different for verbal and visual information, except in the case of brightness. We suggest that the image intrinsic to a sound sources, evoked by verbal and visual information, affects the evaluation of sounds. Furthermore, moving pictures (visual information) contain a variety of information, whereas verbal information gives only determinative information. When this discrepancy produces appreciable differences between verbal and visual information, the changes in the factor scores can be rationally explained. Hence, we consider both the visibility and movement of the sound source to be important factors in our perception of environmental sounds.