著者
Motomu NAKASHIMA Shun MAEDA Takahiro MIWA Hiroshi ICHIKAWA
出版者
The Japan Society of Mechanical Engineers
雑誌
Journal of Biomechanical Science and Engineering (ISSN:18809863)
巻号頁・発行日
vol.7, no.2, pp.102-117, 2012 (Released:2012-03-13)
参考文献数
32
被引用文献数
26 25

In this study, the optimal arm strokes in crawl swimming which maximize the swimming speed and propulsive efficiency were solved computationally. For this objective, an optimizing method which consisted of the random search and the PSO (Particle Swarm Optimization) algorithm was constructed. In order to consider the muscle strength characteristics of the swimmer as the constraint condition of the optimization, an experiment to measure the maximum joint torques was carried out for various joint angles and angular speeds. Using the measured experimental data as the reference values, a musculoskeletal simulation model was constructed. By the constructed musculoskeletal model, muscle strength characteristics in various conditions were investigated and used to create a database. Using this database, the optimizing calculation was finally conducted and the following results were obtained: In the optimization maximizing the swimming speed, the swimming speed became maximum when the stroke cycle was 0.9 s. A relatively I-shaped stroke was obtained in this case. In the optimization maximizing the propulsive efficiency, the propulsive efficiency became maximum when the stroke cycle was 1.3 s. A relatively S-shaped stroke was obtained in this case. Two strokes which respectively maximized the swimming speed and propulsive efficiency were very similar to each other when the stroke cycles were the same. The swimming speeds and stroke cycles obtained in the optimizing calculation were within reasonable ranges compared to the actual races.
著者
Hiroko P. Indo Hsiu-Chuan Yen Ikuo Nakanishi Ken-ichiro Matsumoto Masato Tamura Yumiko Nagano Hirofumi Matsui Oleg Gusev Richard Cornette Takashi Okuda Yukiko Minamiyama Hiroshi Ichikawa Shigeaki Suenaga Misato Oki Tsuyoshi Sato Toshihiko Ozawa Daret K. St. Clair Hideyuki J. Majima
出版者
日本酸化ストレス学会
雑誌
Journal of Clinical Biochemistry and Nutrition (ISSN:09120009)
巻号頁・発行日
pp.14-42, (Released:2014-12-23)
参考文献数
90
被引用文献数
36 232

Fridovich identified CuZnSOD in 1969 and manganese superoxide dismutase (MnSOD) in 1973, and proposed ”the Superoxide Theory,” which postulates that superoxide (O2•−) is the origin of most reactive oxygen species (ROS) and that it undergoes a chain reaction in a cell, playing a central role in the ROS producing system. Increased oxidative stress on an organism causes damage to cells, the smallest constituent unit of an organism, which can lead to the onset of a variety of chronic diseases, such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis and other neurological diseases caused by abnormalities in biological defenses or increased intracellular reactive oxygen levels. Oxidative stress also plays a role in aging. Antioxidant systems, including non-enzyme low-molecular-weight antioxidants (such as, vitamins A, C and E, polyphenols, glutathione, and coenzyme Q10) and antioxidant enzymes, fight against oxidants in cells. Superoxide is considered to be a major factor in oxidant toxicity, and mitochondrial MnSOD enzymes constitute an essential defense against superoxide. Mitochondria are the major source of superoxide. The reaction of superoxide generated from mitochondria with nitric oxide is faster than SOD catalyzed reaction, and produces peroxynitrite. Thus, based on research conducted after Fridovich’s seminal studies, we now propose a modified superoxide theory; i.e., superoxide is the origin of reactive oxygen and nitrogen species (RONS) and, as such, causes various redox related diseases and aging.