著者

Yoshio Tsuda Yoshihide Maekawa Kohei Ogawa Kentaro Itokawa Osamu Komagata Toshinori Sasaki Haruhiko Isawa Takashi Tomita Kyoko Sawabe

出版者

国立感染症研究所 Japanese Journal of Infectious Diseases 編集委員会

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

pp.JJID.2014.576, (Released:2015-03-13)

参考文献数

27

被引用文献数

4 48

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A total of 160 autochthonous dengue cases transmitted by Aedes albopictus were reported from August to October 2014 in Tokyo Metropolis, Japan. Ae. albopictus is a medically important vector of dengue virus which has been expanding its geographic distribution in temperate regions. The understanding of the distribution and density of biting Ae. albopictus during the dengue outbreak case in Tokyo 2014 is valuable and important to evaluate the epidemic-risk of dengue fever in other highly populated cities in Europe. Of the 160 cases, 134 patients had visited a same park located in central Tokyo, Yoyogi Park. Mosquitoes infected with dengue virus were collected from this park suggesting that the place was the exclusive center of dengue transmission. This study aimed to collect referential data to estimate the transmission threshold of dengue virus in terms of biting density of Ae. albopictus and demonstrated high transmission-risk areas of dengue virus in Yoyogi Park and the vicinity. The overall mean density of biting Ae. albopictus, 7.13/man/8 min, was sufficiently high for successful transmission of dengue virus, and areas with biting densities higher than the overall mean density were classified as high transmission-risk areas of dengue virus in Yoyogi Park.

著者

Takashi TOMITA Shigeki HAGIHARA Masaya SHIMAKAWA Naoki YONEZAKI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E105-D, no.10, pp.1665-1677, 2022-10-01

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This paper focuses on verification for reactive system specifications. A reactive system is an open system that continuously interacts with an uncontrollable external environment, and it must often be highly safe and reliable. However, realizability checking for a given specification is very costly, so we need effective methods to detect and analyze defects in unrealizable specifications to refine them efficiently. We introduce a systematic characterization on necessary conditions of realizability. This characterization is based on quantifications for inputs and outputs in early and late behaviors and reveals four essential aspects of realizability: exhaustivity, strategizability, preservability and stability. Additionally, the characterization derives new necessary conditions, which enable us to classify unrealizable specifications systematically and hierarchically.

著者

Takashi Tomita Hidekazu Goto Yuya Yoshimura Kazushige Kato Tadashi Yoshida Katsuya Tanaka Kenji Sumiya Yukinao Kohda

出版者

The Pharmaceutical Society of Japan

雑誌

Biological and Pharmaceutical Bulletin (ISSN:09186158)

巻号頁・発行日

vol.39, no.4, pp.648-651, 2016-04-01 (Released:2016-04-01)

参考文献数

9

被引用文献数

4 13

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The present study examined the dissolution of magnesium oxide (MgO) from MgO tablets placed in a food thickening agent (food thickener) and its effects on laxative activity. We prepared mixtures of MgO tablets suspended in an aqueous suspension and food thickeners in order to evaluate the dissolution of MgO. The results of the dissolution tests revealed that agar-based food thickeners did not affect the MgO dissolution. In contrast, some xanthan gum-based food-thickener products show dissolution rates with certain mixtures containing disintegrated MgO tablets suspended in a food thickener that decrease over time. However, other xanthan gum-based food-thickener products show dissolution rates that decrease immediately after mixing, regardless of the time they were allowed to stand. In order to investigate the laxative activity of MgO, we orally administered a mixture of MgO suspension and food thickener to mice and observed their bowel movements. The animal experiments showed that when agar-based food thickeners were used, the laxative activity of MgO was not affected, but it decreased when xanthan gum-based food thickeners were used.

著者

Kohei Ogawa Osamu Komagata Toshihiko Hayashi Kentaro Itokawa Shigeru Morikawa Kyoko Sawabe Takashi Tomita

出版者

国立感染症研究所 Japanese Journal of Infectious Diseases 編集委員会

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

pp.JJID.2015.038, (Released:2015-06-12)

参考文献数

21

被引用文献数

8

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The objective of this study was to clarify the efficacy of a currently-available DEET repellent against tick species in Japan. We performed two different field trials: “human trap,” and “flag-dragging.” In total, 482 ticks were collected from white flannel cloths in field studies. The species of collected ticks consisted of Ixodes persulcatus and I. ovatus which accounted for 5.3 and 94.7% in the human trap test and 31.4 and 68.6% in the flag-dragging test, respectively. The repellency levels of DEET-treated flannel cloths in the human trap and flag-dragging tests were 84.0 and 99.7%, respectively. The escape time of I. persulcatus and I. ovatus female adults from DEET-treated flannel cloth was measured. Median escape times for I. persulcatus and I. ovatus on DEET-treated flannel cloth were 48 s (95% CI: 30–96) and 10 s (95% CI: 5–24), respectively. In contrast, many ticks remained on untreated flannel for 10 min after mounting. These results indicate that DEET repellents appear to prevent tick bites and that the use of DEET repellents against ticks is effective as a personal protective measure.