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Predecessor
Volume 35, Issue 9
Displaying 1-3 of 3 articles from this issue
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Original Paper
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Yasuhiro ASADA, Yumiko OHKOUCHI, Sadahiko ITOHArticle type: Original Paper
2012 Volume 35 Issue 9 Pages 135-142
Published: 2012
Released on J-STAGE: September 10, 2012
JOURNAL FREE ACCESSDisability Adjusted Life Years (DALYs) are good estimates of the effects caused by waterborne pathogens in drinking water. The illness-to-infection rate of Campylobacter jejuni is one of the most important factors for estimating DALYs. In this study, the illness-to-infection rate of Campylobacter jejuni was estimated on the basis of seroepidemiological survey. From the data of serum antibody levels against C. jejuni, the cutoff levels for asymptomatic infection were set on the basis of medical data from previous studies and using a statistical procedure. From these cutoff levels, the percentage of people with asymptomatic infection was estimated to be 7.9 - 35.0% and 12.1 - 13.6%, respectively. By using the numbers of people with symptomatic infection estimated using the number of laboratory-confirmed cases, the illness-to-infection rate of C. jejuni was estimated to be 12.1 - 53.8% and 31.3 - 35.1%, respectively.View full abstractDownload PDF (670K)
Note
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Yasuo SHIMIZU, Hiroji TAKAHASHIArticle type: Note
2012 Volume 35 Issue 9 Pages 143-149
Published: 2012
Released on J-STAGE: September 10, 2012
JOURNAL FREE ACCESSThere are five evaluation axes for the "soundness indicators of water environment". However, the levels of importance of each of these axes or individual indicators, which an observer considers, are not the same. In consideration of an investigator's subjectivity, the analytic hierarchy process (AHP) technique is proposed as a method of evaluating a water environment synthetically. The structure of subjective judgment, which serves as a backdrop to an investigator's judgment, is analyzed. First, the same subject performs water environmental research at three points of a case river and clarifies the features of each water environment. Subsequently, a hierarchical evaluation factor structure of the soundness index is built. By applying the AHP technique, the result well described subjectivity of the observer, which showed the different tendency from typical method. It is considered that the AHP technique is an effective method of understanding an investigator's feeling explicitly as well as the water environment completely.View full abstractDownload PDF (2061K)
Survey Report
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Shingo MASUKI, Kenichi WAKABAYASHI, Satoru TAKAHASHI, Hiroshi BESSYO, ...Article type: Survey Report
2012 Volume 35 Issue 9 Pages 151-157
Published: 2012
Released on J-STAGE: September 10, 2012
JOURNAL FREE ACCESSThe vertical migration of blue-green algae in a stratified dam reservoir was investigated from 12:00 Sept. 18 to 14:00 Sept. 19, 2009 (at 2 h intervals). The result shows that the rates of sinking to depths of 5 m and 9.5 m from the surface were 0.35 m·h-1 and 0.73 m·h-1, the rates of flotation toward the surface from depths of 5 m and 9.5 m were 0.41 m·h-1 and 0.79 m·h-1. A diurnal thermocline was formed. The diurnal vertical migration cycle shows that the blue-green algae floated and covered the surface at 12:00, started sinking at 14:00, and reached the deepest part (9.5 m) at 0:00. The blue-green algae flotation toward the surface from depths of 5 m and 9.5 m was observed after 2:00 and the blue-green algae reached the surface at 12:00.View full abstractDownload PDF (1173K)
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