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1.
This study proposes a novel cell collection method based on collagenase treatment and ultrasonic vibration. The method collects calf chondrocytes from a reusable metal cell culture substrate. To develop our concept, we calculated the natural vibration modes of the cell culture substrate by a finite element method, and conducted eigenvalue and piezoelectric-structural analyses. Selecting the first out-of-plane vibration mode of the substrate, which has a single nodal circle, we designed and fabricated the cell collection device. The excited vibration mode properly realized our intentions. We then evaluated the cell collection ratio and the growth response, and observed the morphology of the collected cells. The collagenase and ultrasonic vibration treatment collected comparable numbers of cells to conventional trypsin and pipetting treatment, but improved the proliferating cell statistics. Morphological observations revealed that the membranes of cells collected by the proposed method remain intact; consequently, the cells are larger and rougher than cells collected by the conventional method. Therefore, we present a promising cell collection method for adhesive cell culturing process. 相似文献
2.
Koyama H Muraki Y Ae M 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(2):139-153
We investigated the immediate effects of the combined use of inclined and raised flat boards on the take-off motion of the long jump. Eight male long jumpers were videotaped with two high-speed video cameras (250 Hz) set perpendicular to the runway. The athletes jumped with three modified take-off boards: upward-inclined boards of two different inclinations (2.5 and 5.0 degrees), and a raised flat board (50 mm high). The jumpers performed pre- and post-jumps using their own techniques before and after use of the boards to test their effects. The post- jump revealed significantly less reduction in the horizontal velocity during the take-off than the pre-jump, and the effectiveness of converting the velocity from horizontal to vertical increased significantly in the post-jump. The post-jump demonstrated significantly less knee flexion of the take-off leg during take-off. The reduced knee flexion and slower extension velocity of the take-off leg in the second phase of the post-jump contributed to increasing the knee extension torque in the second phase and resulted in the increases in vertical ground reaction force and vertical velocity. These results suggest that the combined use of the inclined and raised flat boards induced immediate effective changes in the kinematics and kinetics of the take-off motion and represent appropriate training tools for take-off techniques of the long jump. 相似文献
3.
In this article, we explore how Chinese scholars in the USA recount their transnational collaborations and linkages. Guided by post-colonial theories and cultural studies of transnational academic mobility, we utilise in-depth interviews to resituate the scholars' experiences within a discourse of diasporic intellectual networks. We argue that their movement is not simply a transfer from one physical location to another, but rather that the movement itself constitutes a new space of identification, of belonging and of global imagination. We conclude by considering the transnational implications of local agency for global connectivity and emergence of new subjectivities in a fluid global world. 相似文献
4.
Koyama H Muraki Y Ae M 《Sports biomechanics / International Society of Biomechanics in Sports》2005,4(2):113-129
In this study, we investigated the effects of inclined and raised flat boards on the take-off motion of the long jump to determine the effectiveness of these boards as training tools. Eight male long jumpers were videotaped with two high-speed video cameras (250 Hz) set perpendicular to the runway. Four different jumps were performed with in four conditions, all with their medium length run-up: a long jump with their normal technique, long jumps on upward inclined boards of two different inclinations (2.5 and 5.0 degrees), and a long jump on a raised flat board (0 degrees, 50 mm). The raised flat board enhanced the pivot of the body over the take-off foot, and reduced flexion of the take-off leg knee. However, the inclined boards did not produce the same effects as the raised flat board. The use of the inclined boards increased the vertical velocity of the centre of mass of the body at toe-off, resulting in increased airborne time. These results suggest that the raised flat board and inclined boards would be effective in improving long jumpers' techniques during the take-off and airborne phases. 相似文献
5.
When we consider the gap between mathematics at elementary and secondary levels, and given the logical nature of mathematics
at the latter level, it can be seen as important that the aspects of children's logical development in the upper grades in
elementary school be clarified. In this study we focus on the teaching and learning of “division with decimals” in a 5th grade
classroom, because it is well known to be difficult for children to understand the meaning of division with decimals, caused
by certain conceptions which children have implicitly or explicitly. In this paper we discuss how children develop their logical
reasoning beyond such difficulties/misconceptions in the process of making sense of division with decimals in the classroom
setting. We then suggest that children's explanations based on two kinds of reversibility (inversion and reciprocity) are
effective in overcoming the difficulties/misconceptions related to division with decimals, and that they enable children to
conceive multiplication and division as a system of operations. 相似文献
6.
Daisuke Matsui Isao Watanabe Teruhide Koyama Etsuko Ozaki Nagato Kuriyama Shigeto Mizuno 《Journal of sports sciences》2017,35(18):1788-1793
Osteopenia is a condition in which bone mineral density (BMD) is lower than normal. Exercise increases BMD in both the young and adults. This study aimed to compare the radial apparent BMD (aBMD) in Japanese females who are Kendo practitioners (KPs) and those with no regular exercise habits (no-REH). The analysis participants consisted of 45 KPs (mean age: 49.4 years old) and 110 no-REH (mean age: 48.8 years old). Radial aBMD was measured using an ultrasonic bone densitometry system. Radial aBMD in KPs was 196.1 ± 33.9 mg/cm3, and was 182.9 ± 45.3 mg/cm3 in no-REH participants. KPs had significantly higher BMD than no-REH participants. In KPs, left radial aBMD was 196.1 ± 33.9 mg/cm3, and right radial aBMD was 184.5 ± 37.7 mg/cm3. The left radius was also significantly higher than the right radius with respect to aBMD in KPs. After adjusting for age, body mass index, menstrual status, parous women and frequency of milk and dairy intake, the odds ratio (OR) of osteopenia associated with no-REH was 6.58 (95% confidence interval (CI): 1.72–25.1) and the prevalence ratio (PR) of osteopenia associated with no-REH was 4.12 (95% CI: 1.23–13.7). Therefore, the Kendo practice may have a protective efficacy for osteopenia in women. 相似文献
7.
Jill P. Koyama 《教育政策杂志》2013,28(5):701-720
This article ethnographically examines the ways in which No Child Left Behind (NCLB) links local practices to the centralized processing of data through its narrowing of procedures and measurements aimed at accountability. Framed by actor-network theory, it draws upon data consistently collected between June 2005 and October 2008, and then intermittently through October 2010, to consider the ways in which policy technologies, such as standardized testing, bring together New York City (NYC) public schools, district administrators, for-profit educational support businesses, and government officials to address the accountability requirements of NCLB. This article reveals how, through a range of sophisticated mechanisms that support the generation and comparison of data, NYC schools become reduced to data calculation and management centers. NCLB’s standardization, privatization, and marketization encourage local policy actors to become complicit in standardizing and quantifying academic assessment through their reliance on services and products marketed to schools and districts that are not meeting academic benchmarks. These services, mostly offered by for-profit vendors, help keep schools in compliance with policy requirements, but replace a focus on student learning with the production, management, and sometimes the fabrication, of data. 相似文献
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9.
Kazuya Takeda Soichiro Koyama Tomoko Nagai Hiroaki Sakurai Yoshikiyo Kanada 《Measurement in physical education and exercise science》2018,22(1):19-24
The aim of this study was to clarify the intra- and inter-rater reliability of the rate of force development in hip abductor muscle force measurements using a hand-held dynamometer. Thirty healthy adults were separately assessed by two independent raters on two separate days. Rate of force development was calculated from the slope of the force-time curve that was divided into four time intervals (50, 100, 200, and 300 ms). The highest values of the three trials were used for statistical analysis. The intra-class correlation coefficient with a 95% confidence interval, standard error of measurement, and minimal detectable change at the 95% confidence level were calculated for each interval. For assessment of systematic error, Bland-Altman analysis was used. The results indicated that intra- and inter-rater reliability of the highest values at all intervals were sufficient (intra-class correlation coefficient > .7). The Bland-Altman analysis did not show systematic error in either reliability measure. 相似文献
10.
Masafumi Koyama Kazuhiro Morita Masao Fuketa Jun-Ichi Aoe 《Information processing & management》1998,34(6):761-773
Case structures are useful for natural language systems, such as word selection of machine translation systems, query understanding of natural language interfaces, meaning disambiguation of sentences and context analyses and so on. The case slot is generally constrained by hierarchical concepts because they are simple knowledge representations. With growing hierarchical structures, they are deeper and the number of concepts to be corresponded to one word increases. From these reasons, it takes a lot of cost to determine whether a concept for a given word is a sub-concept for concepting the case slot or not. This paper presents a faster method to determine the hierarchical relationships by using trie structures. The worst-case time complexity of determining relationships by the presented method could be remarkably improved for the one of linear (or sequential) searching, which depends on the number of concepts in the slot. From the simulation result, it is shown that the presented algorithm is 6 to 30 times faster than linear searching, while keeping the smaller size of tries. 相似文献