著者

Masatoshi Nakamura Tome Ikezoe Satoru Nishishita Hiroki Tanaka Jun Umehara Noriaki Ichihashi

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.8, no.3, pp.113-116, 2019-05-25 (Released:2019-05-18)

参考文献数

24

被引用文献数

9 15

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Static stretching (SS) is widely used to decrease and retain the passive stiffness of the muscle-tendon unit in clinical and athletic settings. It is important to consider the minimum SS duration required to decrease the passive stiffness of the hamstring, from the perspective of injury prevention of the hamstring muscle. The purpose of this study was to investigate the time course of the effect of static stretching (SS) on passive stiffness of the hamstring and to clarify the minimum SS duration required to decrease the passive stiffness. Fifteen healthy males participated in this study. Fifteen healthy and non-athlete male volunteers participated in this study. SS of 60-s session was performed for five sessions with a 30-s rest between sessions. Passive stiffness was measured prior to SS (PRE) and immediately after each SS session to determine the minimum SS duration required to decrease the passive stiffness. The passive stiffness was calculated as the slope of the torque-angle curve corresponding to 50% of the final angle (Nm/°). Passive stiffness after 180, 240, and 300 s of SS was significantly lower than that at PRE. Our results showed that SS for >180 s is recommended to decrease the passive stiffness of the hamstring muscle.

著者

Tomohiro Nishimura Wittaya Tawong Hiroshi Sakanari Takuji Ikegami Keita Uehara Daiki Inokuchi Masatoshi Nakamura Takuya Yoshioka Shota Abe Haruo Yamaguchi Masao Adachi

出版者

The Plankton Society of Japan, The Japanese Association of Benthology

雑誌

Plankton and Benthos Research (ISSN:18808247)

巻号頁・発行日

vol.13, no.2, pp.46-58, 2018-05-30 (Released:2018-05-24)

参考文献数

68

被引用文献数

13

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Ciguatera fish poisoning (CFP) is caused by toxins originating from an epiphytic/benthic dinoflagellate of the genus Gambierdiscus. In Japan, CFP cases have been increasingly reported not only in subtropical areas but also in temperate areas. It is therefore important to study Gambierdiscus cell occurrences, cell densities, and population dynamics to address CFP outbreaks in Japan. This study assessed the densities in Japanese shallow waters (0.1–3 m depths) and revealed that the densities were lower than those in tropical and subtropical areas worldwide. In the shallow waters of Tosa Bay, a Japanese temperate area, population dynamics of Gambierdiscus cells were assessed monthly between 2007 and 2013. Gambierdiscus did not show substrate preferences for macroalgal species. The cell densities in the area ranged from 0 to 232.2 cells g−1 wet weight algae. The average cell densities in spring, summer, autumn, and winter were 0.1±0.4, 0.9±2.6, 4.0±20.6, and 0.4±1.4 cells g−1 wet weight algae, respectively. The cell densities in summer and autumn were not significantly different (p>0.05), whereas those in summer and autumn were significantly higher than those in spring and winter (p<0.01). A significant positive correlation between cell densities and sea surface temperatures (SSTs) was observed (rs=0.21, p<0.001), while a significant negative correlation between cell densities and salinity was recognized (rs=−0.18, p<0.001). These results suggest that cell densities of Gambierdiscus in Japanese temperate shallow waters increase in summer and autumn when the SST is high and salinity is moderately low.

著者

Aoi MATSUMURA Hiroshige TATEUCHI Masatoshi NAKAMURA Noriaki ICHIHASHI

出版者

Japanese Society of Physical Therapy

雑誌

Physical Therapy Research (ISSN:21898448)

巻号頁・発行日

vol.26, no.2, pp.58-64, 2023 (Released:2023-08-20)

参考文献数

29

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Objective: Generally, low-intensity training is recommended as selective training of the infraspinatus muscle. This study aimed to investigate whether an 8-week intervention of low-intensity, slow-movement, external rotation exercise of the shoulder led to an increase in muscle strength with shoulder external rotation and cross-sectional area (CSA) infraspinatus muscle. Methods: Sixteen healthy male volunteers were randomly assigned to the low-intensity and slow-movement (LS) group (N = 8) or the normal-intensity and normal-speed (NN) group (N = 8). The LS and NN groups performed shoulder external rotation exercises with low intensity and slow movement, and normal intensity and normal speed, respectively. The exercise session consisted of three sets of 10 repetitions, which were performed three times per week for 8 weeks. We measured the CSA of the infraspinatus and muscle strength of the shoulder external rotation before and after the 8-week intervention. Results: A significant increase in infraspinatus CSA from baseline to 8 weeks was found in the LS group (7.3% of baseline) but not in the NN group. No significant differences were found in the muscle strength of shoulder external rotation. Conclusion: Our results suggest that low-intensity exercise of the infraspinatus is effective for muscle hypertrophy when performed with slow movement. This finding may help patients who should avoid excessive stress in the early phase of rehabilitation.

著者

Aoi MATSUMURA Hiroshige TATEUCHI Masatoshi NAKAMURA Noriaki ICHIHASHI

出版者

Japanese Society of Physical Therapy

雑誌

Physical Therapy Research (ISSN:21898448)

巻号頁・発行日

pp.E10227, (Released:2023-04-22)

参考文献数

29

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Objective: Generally, low-intensity training is recommended as selective training of the infraspinatus muscle. This study aimed to investigate whether an 8-week intervention of low-intensity, slow-movement, external rotation exercise of the shoulder led to an increase in muscle strength with shoulder external rotation and cross-sectional area (CSA) infraspinatus muscle. Methods: Sixteen healthy male volunteers were randomly assigned to the low-intensity and slow-movement (LS) group (N = 8) or the normal-intensity and normal-speed (NN) group (N = 8). The LS and NN groups performed shoulder external rotation exercises with low intensity and slow movement, and normal intensity and normal speed, respectively. The exercise session consisted of three sets of 10 repetitions, which were performed three times per week for 8 weeks. We measured the CSA of the infraspinatus and muscle strength of the shoulder external rotation before and after the 8-week intervention. Results: A significant increase in infraspinatus CSA from baseline to 8 weeks was found in the LS group (7.3% of baseline) but not in the NN group. No significant differences were found in the muscle strength of shoulder external rotation. Conclusion: Our results suggest that low-intensity exercise of the infraspinatus is effective for muscle hypertrophy when performed with slow movement. This finding may help patients who should avoid excessive stress in the early phase of rehabilitation.

著者

渡辺 隆 岩上 直幹 小川 利紘 中村 正年 Takashi WATANABE Naomoto IWAGAMI Toshihiro OGAWA Masatoshi NAKAMURA

雑誌

南極資料 (ISSN:00857289)

巻号頁・発行日

no.69, pp.111-115, 1980-03

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冬期高緯度において,中間圏オゾンのロケット観測を太陽吸光法を用いて行った.得られた高度分布は,典型的な中緯度の値にくらべて著しく小さい.

著者

Kosuke Takeuchi Masatoshi Nakamura Hironobu Kakihana Fumiko Tsukuda

出版者

Japan Society of Physical Education, Health and Sport Sciences

雑誌

International Journal of Sport and Health Science (ISSN:13481509)

巻号頁・発行日

pp.201829, (Released:2019-04-24)

参考文献数

37

被引用文献数

2 12

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[Purpose] The purpose of the present study was to investigate static stretching and dynamic stretching protocol.[Methods] 138 coaches of 21 different sports completed a self-reporting questionnaire. The questionnaire was split into four sections and contained fixed-response questions. Section One identified participant demographics. The second and third sections required the participants to detail the static and dynamic stretching they used. The fourth section of the questionnaire identified how participants learned about stretching.[Results] There were 126 coaches using static or dynamic stretching, while 12 coaches did not. Thirty-nine coaches used only static stretching, 10 coaches used only dynamic stretching, and 77 coaches used both types of stretching. The purposes of static stretching were to increase flexibility and to prevent injuries. The purposes of dynamic stretching were improvement of performance and prevention of injuries. The duration of one bout of static and dynamic stretching in a warm-up were 21.8 ± 13.2 and 22.1 ± 16.2 seconds, respectively. A common way to learn about stretching was participation in training sessions.[Discussion] Coaches should use SS for a greater length of time to achieve their purposes. The results of the present study showed gaps between evidence and practice.

著者

Noriaki Ichihashi Satoko Ibuki Masatoshi Nakamura

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.3, no.1, pp.1-10, 2014-03-25 (Released:2014-03-20)

参考文献数

76

被引用文献数

2 2

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The acute and chronic effects of static stretching (SS) on joint range of motion (ROM) and stiffness of muscle-tendon unit (MTU) and/or muscle was reviewed. Previous studies have provided evidence that SS is effective in increasing ROM, both immediately and chronically. Moreover, 75 seconds (75s) SS is sufficient for eliciting an immediate, acute effect. In contrast, the recent trend is to evaluate the effect of stretching not by measuring ROM, but by measuring stiffness in order to eliminate the effect of psychological factors. However, the findings of studies measuring stiffness are conflicting, with some results indicating a decrease in stiffness and others indicating no change in stiffness despite changes in joint ROM. Our study results support that stiffness decrease with SS, and that >2 min of SS is effective in eliciting the effect. The retention time taken to achieve the effect of SS is also under discussion, and the retention time may differ for ROM and muscle stiffness. Concerning the chronic effect of SS, many studies have indicated that a routine SS program decreases passive torque or MTU and muscle stiffness. However, the underlying mechanism for this decrease remains to be clarified.

著者

Masatoshi NAKAMURA Masato INAGI Kazuya TANIGAWA Tetsuo HIRONAKA Masayuki SATO Takashi ISHIGURO

出版者

一般社団法人 電子情報通信学会

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E95.D, no.2, pp.324-334, 2012-02-01 (Released:2012-02-01)

参考文献数

15

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In this paper, we propose a placement and routing method for a new memory-based programmable logic device (MPLD) and confirm its capability by placing and routing benchmark circuits. An MPLD consists of multiple-output look-up tables (MLUTs) that can be used as logic and/or routing elements, whereas field programmable gate arrays (FPGAs) consist of LUTs (logic elements) and switch blocks (routing elements). MPLDs contain logic circuits more efficiently than FPGAs because of their flexibility and area efficiency. However, directly applying the existing placement and routing algorithms of FPGAs to MPLDs overcrowds the placed logic cells and causes a shortage of routing domains between logic cells. Our simulated annealing-based method considers the detailed wire congestion and nearness between logic cells based on the cost function and reserves the area for routing. In the experiments, our method reduced wire congestion and successfully placed and routed 27 out of 31 circuits, 13 of which could not be placed or routed using the versatile place and route tool (VPR), a well-known method for FPGAs.

著者

Tsuyoshi ITO Kazuyuki UCHIDA Masatoshi NAKAMURA Ko NAKASHIMA Kazuhiko SUZUKI Hiroyuki NAKAYAMA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.72, no.10, pp.1387-1390, 2010 (Released:2010-10-29)

参考文献数

18

被引用文献数

1 2

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The paper describes clinical and pathological features of Alexander's disease (AD)-like disorder in a 1 year and 8 months old French bulldog. Clinically, the dog exhibited megaesophagus, emaciation and weakness without any specific neurological symptoms. The dog died of aspiration pneumonia. On the gross observation of formalin-fixed brain, discolored foci were observed in the white matter of the cerebellum and brain stem. Histologically, numerous Rothenthal fibers and hypertrophic astrocytes were distributed especially in the perivascular, subependymal and subpial area of both the cerebrum and cerebellum. The Rosenthal fibers were intensely immunopositive for GFAP and ubiquitin. Demyelination of the white matter was occasionally found in the brain stem. The present case is likely to be categorized in the adult form of AD, though previous AD-like cases in dogs were in the juvenile form.