• Title/Summary/Keyword: Strength Of Evidence

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Health Assessment for Glass Fibre Landfill at Gozan-dong, Inchon (인천시 고잔동에서 제기된 유리섬유에 의한 건강피해 역학 조사)

  • Cho, Soo-Hun;Ju, Yeong-Su;Kim, Kyung-Ryul;Lee, Kang-Kun;Hong, Kug-Sun;Eun, Hee-Chul;Song, Dong-Bin;Hong, Jae-Woong;Kwon, Ho-Jang;Ha, Mi-Na;Han, Sang-Hwan;Seong, Joo-Heon;Kang, Jong-Won
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.1 s.56
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    • pp.77-101
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    • 1997
  • In September 1994, residents of Gozan-dong, Incheon City, made a petition to the government about their health problems which might be caused by previous glass fibre landfill nearby 'H' company. In february 1995, at regular academic meeting of occupational and environmental medicine, a research team of 'D' University presented that they had found glass fibres in groundwater of the area through their survey. They were suspicious of probable association between ingestion of groundwater contaminated with glass fibres and skin tumors among residents. A joint research team was formed and carried out the survey of environment concerning groundwater and its glass fibre existence, and health assessment of residents in the area and industrial workers of 'H' company during May to November, 1995. Analysis of groundwater flow system indicates that the flow lines from the glass fibre landfill pass through or terminate at the 6 houses around the landfill. This means that the groundwater of the 6 houses around the glass fibre landfill could be affected by some possible contaminants from the landfill, but the groundwater quality of the other houses was irrelevant to the landfill. The qualitative and qualitative analyses for glass fibres in 54 groundwater samples including those from the nearby 6 houses, were carried out using SEM equipped with EDS, resulting in no evidence for the presence of glass fibres in the waters. Major precipitates, formed in waters while boiling, were identified as calcium carbonates, in particulary, aragonites in needle form. The results of health assessments of 889 residents in Gozan-dong, participated in this study, showed statistically significant differences in past medical histories of skin tumor and respiratory disease between the exposed group (31 persons who inhabited in 6 houses around the landfill) and the control group, but no significant differences in past medical histories of other diseases, such as cancer mortality, current gastroscopic findings, current skin diseases and respiratory diseases, etc. Also, we could not prove any glass fibres in excised specimens of 9 skin tumors in both groups and there were no health problems possibly associated with glass fibres in employees of the 'H' company. After all, we could not authenticate the association, raised by prior investigators, between groundwater streams, assumedly contaminated with glass fibres or not, and specific disease morbidities or common disease/symptom prevalences. That is, we could not find any glass fibres in groundwater as the only exposure factor of this study hypothesis, and there were not enough certain evidences such as increasing disease prevalences, for examples, skin, respiratory and gastrointestinal diseases etc, possibly related to glass fibre exposure, in exposed group. As a matter of course, the conditions for confirming causal association, for example, strength of the association, consistency of the association, specificity of the association, temporality of the association and dose-response relationship etc, have not been satisfied. In conclusion, we were not able to certify the hypothesis that contamination of groundwater with glass fibres might cause any hazardous health effects in residents who used it for drinking.

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Content Validity of and Information from Elementary Students' Science Portfolio Assessment (초등학교 과학과 포트폴리오 평가의 내용 타당도 검증 및 학생 포트폴리오에서 파악할 수 있는 정보의 유형)

  • Kim, Chan-Jong;Yoon, Sun-Ah
    • Journal of The Korean Association For Science Education
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    • v.22 no.1
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    • pp.190-203
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    • 2002
  • The purpose of this study is to test content validity of a portfolio assessment and to analyse the information which can be obtained from student portfolios. The content validity of the portfolio was tested against the objectives of each lesson and the emphasis of curriculum. The information was identified from the analysis of student portfolios. Students' portfolios from a fourth grade class in Pyeungteak, Kyeungki-do were used for analysis. The portfolios included students' evidence of learning on (I) Strata, Unit 2 'Strata and Fossil,' and (3) Change of Object by Heat, Unit 4 'Heat and Change of Object'. Fourth-grade science textbooks were also analyzed to understand the base level information for portfolio analysis. Two science education specialists and ten elementary teachers majored in science education took part in this analysis. The results of the analysis showed $70{\sim}100%$ of agreement between the objectives of lesson and portfolio forms. Over 90% of agreement is reached between portfolio forms and the emphasis of the curriculum. Student portfolios revealed much information on comprehension, observation, will to study, and process of learning. They also revealed some information on drawing conclusion, communication. self-direction, progress of learning, self-concept, interaction, and process of learning. As a whole, the information in students' portfolios is similar with that dealt in science textbooks. However, students' portfolios have more information on anticipation, will to study, self-direction, and interaction. On the contrary, science textbook deals more with information on observation, planning inquiry, than students' portfolios. The portfolio assessment examined has very sound content validity. The results also show that much more and various information which can not be obtained from pencil and paper test could be obtained from student portfolios. The use of information, obtained from student portfolios will make it possible understand students' learning. their strength and weakness, hence improve student' science learning.

Sorption Studies of $Cd^{2+}$ on Calcite: Kinetics and Reversibility (방해석의 $Cd^{2+}$ 흡착현상에 대한 연구)

  • Yoon, Hyeon;Reeder, Richard J.
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.2
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    • pp.104-113
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    • 2002
  • The sorption of Cd$^{2+}$ on calcite was studied in aqueous solutions of several electrolytes. The Cd$^{2+}$ concentration, 10$^{-8}$ M, was kept well below saturation with respect to CdCO$_3$(s). Sorption behavior of Cd$^{2+}$ in different ionic strengths of NaClO$_4$solutions shows that sorption is independent of ionic strength. This result suggests that Cd$^{2+}$ sorption on calcite surface is of a specific nature, and adsorption is controlled by an inner-sphere type of surface complex. Two stages in the sorption behavior could be identified: an initial rapid uptake, followed by slower uptake reaching a maximum steady state by 145 hrs. No evidence was observed for surface precipitation, although it can not be entirely ruled out. Desorption of Cd$^{2+}$ from the calcite surface after resuspension into Cd-free solution is initially very rapid, but depends partly on the previous sorption history. Desorption behavior of Cd$^{2+}$ show that an initial rapid desorption followed either by slow uptake reaching a maximum, as in the adsorption experiments, or slowing desorption to reach a steady state minimum. This irreversible behavior of Cd$^{2+}$ sorption and desorption may act as one of the controls for regulating the mobility of dissolved Cd$^{2+}$ natural aqueous systems. Calculated adsorption partition coefficients suggest that overall sorption and desorption process in the concentration range are controlled by d single mechanism.ingle mechanism.

Does Sarcopenic Obesity Affect Physical Function and Physical Fitness of Korean Older Women? (근위축비만이 국내 여성고령자의 신체기능과 체력에 미치는 영향)

  • Hong, Seung-youn
    • 한국노년학
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    • v.30 no.3
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    • pp.831-842
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    • 2010
  • BACKGROUND: Sarcopenic obesity(SO), a condition of the reduction in muscle mass paired with an increased fat mass has been paid attention because of its association with disability in later life. A few evidence, however, has reported the association with these factors. PURPOSE: To explore the association among SO, physical function and fitness in older women. METHOD: 257 older women(age of 74) were recruited from Y city and 7 physical functions and 4 fitness tests were measured. Participants were classified into one of four groups based on their body fat and muscle mass: Normal group (GR-A), high fat(GR-B), sarcopenia(GR-C), and sarcopenic obese(GR-D). GLMand LSD-test were conducted with SPSS 12.0. RESULTS: Chair stand, arm-curl, back-scratch, 2-min steps of GR-A was higher than GR-C and GR-D(p<.05). One-leg stand of GR-A was higher than GR-D(p<.01) and of GR-C was higher than GR-D(p<.01).8ft-TUG of GR-D was lower than GR-A(p<.01). Grip strength, knee extension of GR-A was higher than that of GR-C and GR-D(p<.01) and knee flexion of GR-A was also higher than that of GR-C and GR-D(p<.01). CONCLUSION: Based on our findings, we conclude that SO is significantly associated with lower physical function and fitness in older Korean women, which alarm the risk of frailty induced by SO.