著者
工藤 伸一 石田 淳一 吉本 恵子 水野 正一 大島 澄男 古田 裕繁 笠置 文善
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.51, no.1, pp.12-18, 2016 (Released:2016-07-06)
参考文献数
16
被引用文献数
5

Radiation Effects Association has carried out radiation epidemiological study for nuclear industry workers during 1990-2010. We assembled a cohort of 204,103 workers. The average cumulative dose was 13.8 mSv (median 1.0 mSv, interquartile range (IQR) 0.0-10.7 mSv) and the average follow-up period was 14.2 year. The present report has not concluded that low-dose radiation increases cancer mortality based on the follow-up data through 2010. One reason is that analyses among 75,442 respondents― the average cumulative dose was 25.8 mSv (median 6.3 mSv, IQR 0.2-28.0 mSv) and the average follow-up period was 8.3 year―to the lifestyle surveys revealed the decrease of the ERR after adjusting for smoking habits or educational year, suggesting that confounder has a large effect on the association between radiation exposure and mortalities in the cohort. Another reason is that in analyses on all cohort members, no significant ERR was observed in all death, and leukemia excluding chronic lymphoid leukemia. Significant ERR was seen in all cancers excluding leukemia, but this significance of the ERR might be affected by confounder such as smoking, because the significance of the ERR in all cancers excluding leukemia originates in the significance of the ERR in lung cancer.
著者
石田 淳一 子安 増生
出版者
一般社団法人 日本科学教育学会
雑誌
科学教育研究 (ISSN:03864553)
巻号頁・発行日
vol.12, no.1, pp.14-21, 1988-03-10 (Released:2017-06-30)

642 children of grade 1 and 2 were given eight types of word arithmetic problems to test their understanding of semantic structure of addition and subtraction from two points of view: (1) choosing operations required to solve word arithmetic problems, and (2) making up word arithmetic problems to fit given calculations. The types of addition problems were join, combine, compare (compared quality unknown), and those of subtraction problems were separate, combine, compare (difference unknown), compare (compared quality unknown), join missing addend. The main findings are as follows. (a) Semantic structure has a profound effect upon the relative difficulty of word arithmetic problems. (b) Considering the childrens' performance from the two points mentioned above, especially, compare (compared quality unknown) [addition], combine [subtraction], and join missing addend problems are more difficult than others. (c) It is more difficult for children to make up word arithmetic problems to fit given calculations than to solve ordinary word arithmetic problems.
著者
工藤 伸一 石田 淳一 吉本 恵子 古田 裕繁 笠置 文善
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.52, no.4, pp.265-274, 2017 (Released:2018-02-24)
参考文献数
33
被引用文献数
1

Although many radiation epidemiological studies have been carried out, there is still uncertainty about the health effects of low dose and low dose-rate radiation in humans. One reason for this uncertainty is that the risk of radiation itself may be too small to detect. Another possible reason is that the main components of cohorts or statistical method vary in each study. Comparing the Excess Relative Risks (ERRs) with other studies is often one approach; however, few studies have denoted the validity of comparing ERRs. To verify the differences in study methods, we summarized them and the results of radiation epidemiological studies to date. Some of these studies targeted high background residents or patients who received CT scans. In the present work, we focused on cohort studies among nuclear industry workers because they assured more accurate dose measurements and had no possibility of reverse causation (i.e., patients who received CT scans had worse health conditions, which prompted the need for the scans). In addition, we limited the studies to those that summarize derived excess relative risks of mortality based on a linear model.
著者
石田 淳一
出版者
横浜国立大学
雑誌
基盤研究(C)
巻号頁・発行日
2008

長期間の足場のある算数授業は既習事項を手がかりに学ぶという信念を形成し、算数学力の向上に効果的であった。また算数シナリオや授業記録を用いた話し合い指導は、子どもが聴いて考えて伝え合う「学び合い」のある授業づくりに役立った。さらに1時間の授業の中に、協同学習を取り入れて、解法の見通しを相談させたり、問題をグループで解決させたりすることは、新しい学びの習得を促進するだけでなく、仲間と協力して学ぶカを育てるのに効果的であった。