• 제목/요약/키워드: Active sampling

검색결과 298건 처리시간 0.028초

항공기 기내 청소노동자의 분진, 초미세먼지(PM2.5) 및 블랙카본 노출수준 평가 (Exposure Assessment of Dust, Ultra Fine Dust(Particulate Matter 2.5, PM2.5) and Black Carbon among Aircraft Cabin Cleaners)

  • 박현희;김세동;김성호;박승현
    • 한국산업보건학회지
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    • 제33권2호
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    • pp.171-187
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    • 2023
  • Objectives: Aircraft cabin cleaning work is characterized by being performed within a limited time in a narrow and enclosed space. The objective of this study was to evaluate the exposure levels to dust, ultra fine dust(PM2.5) and black carbon(BC) among aircraft cabin cleaners. Methods: Active personal air sampling for respirable dust(n=73) and BC(n=47) was conducted during quick transit cleaning(cabin general and vacuum-specific) and seat cover replacement and total dust and PM2.5 were area-air-sampled as well. Also, size distribution of particle was identified with the cleaning workers targeted. Dusts were collected with PVC filters using gravimetric analysis. The concentration of PM2.5 and the particle size distribution were measured with real-time direct reading portable equipment using light scattering analysis. The concentration of BC was measured by aethalometer(filter-based real-time light absorption analysis instrument). Results: The geometric mean of respirable dust was the highest at vacuum cleaning as 74.4 ㎍/m3, following by replacing seat covers as 49.3 ㎍/m3 and cabin general cleaning as 47.8 ㎍/m3 . The arithmetic mean of PM2.5 was 4.83 ~ 9.89 ㎍/m3 inside the cabin, and 28.5~44.5 ㎍/m3 outside the cabin(from bus and outdoor waiting space). From size distribution, PM2.5/PM10 ratio was 0.54 at quick transit cleaning and 0.41 at replacing seat covers. The average concentration of BC was 2~7 ㎍/m3, showing a high correlation with the PM2.5 concentration. Conclusions: The hazards concentration levels of aircraft cabin cleaners were very similar to those of roadside outdoor workers. As the main source of pollution is estimated to be diesel vehicles operating at airports, and it is necessary to replace older vehicles, strengthen pollutant emission control regulations, and introduce electric vehicles. In addition, it is necessary to provide as part of airport-inftastructure a stable standby waiting space for aircraft cabin cleaners and introduce a systematic safety and health management system for all workers in the aviation industry.

음악요법이 초산부의 경막하 무통 분만 중 분만통증, 분만경험, 자아존중감에 미치는 효과: 유사실험 연구 (The effects of music therapy on labor pain, childbirth experience, and self-esteem during epidural labor analgesia in primiparas: a non-randomized experimental study)

  • 안성연;박은지;문유리;이보영;이은별;김동연;정성희;김진경
    • 여성건강간호학회지
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    • 제29권2호
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    • pp.137-145
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    • 2023
  • Purpose: This non-randomized study was performed to evaluate the effects of music therapy on labor pain, the childbirth experience, and self-esteem in women during vaginal delivery. Methods: In total, 136 primiparous women over 37 weeks of gestation receiving epidural analgesia during vaginal delivery were recruited via convenience sampling. To minimize diffusion effects, data from the control group (n=71) were collected first (April 2020 to March 2021), followed by data from the music group (n=65; April 2021 to May 2022). Participants in the music group listened to classical music during labor, while the control group was offered usual care (no music). Labor pain was measured using a numeric rating scale (NRS), and self-esteem and childbirth experience were collected using self-report questionnaires. Data were analyzed using the independent t-test, chi-square test and Cronbach's α coefficients. Results: The overall pain level (NRS) at baseline was 0 in both groups. Mothers in the music therapy group had lower levels of latent pain (t=1.95, p=.005), active pain (t=3.69, p<.001) and transition-phase pain (t=7.07, p<.001) than the control group. A significant difference was observed between the two groups, and the music therapy group expressed more positive perceptions of the childbirth experience (t=-1.36, p=.018). For self-esteem, the experimental group's score was slightly higher, but without a statistically significant difference from the control group. Conclusion: Using music therapy during labor decreased labor pain and improved the childbirth experience. Music therapy can be clinically recommended as a non-pharmacological, safe, and easy method for nursing care in labor.

머신러닝과 3D 프린팅을 이용한 저비용 인공의수 모형 (Low-cost Prosthetic Hand Model using Machine Learning and 3D Printing)

  • 신동욱;염호준;박상수
    • 문화기술의 융합
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    • 제10권1호
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    • pp.19-23
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    • 2024
  • 양손 절단 환자들에게 미용적 목적과 함께 기능적 목적을 갖춘 의수가 필요하며 잔존 근육의 근전도를 이용한 인공 의수에 대한 연구가 활발하나 아직도 비싼 비용의 문제가 있다. 본 연구에서는 저비용의 부품과 소프트웨어인 표면 근전도 센서, 머신러닝 소프트웨어 Edge Impulse, Arduino Nano 33 BLE, 그리고 3D 프린팅을 이용하여 인공의수를 제작하고 성능을 평가하였다. 표면 근전도 센서로 획득하고 Edge Impulse에서 디지털 시그널 프로세싱 과정을 거친 신호들을 이용하여 머신러닝으로 손가락 운동의 종류를 판단하는 훈련을 통해 각 손가락의 굽힘 운동신호를 의수 모델의 손가락들에 전달하였다. 디지털 시그널 프로세싱 조건을 노치 필터 60 Hz, 대역필터 10-300 Hz, 그리고 샘플링 주파수 1,000 Hz로 했을 때, 머신 러닝의 정확도가 82.1%로 가장 높았다. 각 손가락 굴곡 운동간에 혼동될 수 있는 가능성은 약지가 가장 높아서 검지의 운동으로 혼동될 가능성이 44.7 %이었다. 저비용 인공의수의 성공적인 개발을 위해서는 더 많은 연구가 필요하다.

도시.농촌 지역 초등학생의 가족환경, 건강행위 및 건강상태에 관한 비교 (Comparision of Family Environment, Health Behavior and Health State of Elementary Students in Urban and Rural Areas)

  • 배연숙;박경민
    • 지역사회간호학회지
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    • 제9권2호
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    • pp.502-517
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    • 1998
  • This research intends to survey family environment, health behavior and health status of the students in urban-rural elementary schools and analyze those factors comparatively, and use the result as basic material for school health teacher to teach health education in connection with family and regional areas. It also intends to improve a pupil's self-abilitiy in health care. The subjects involve 2,774 students of urban elementary schools and 583 student in rural ones, who were selected by means of a multi -stage probability sampling. Using the questionnaire and school documents, we collected data on family environment, health behavior and health status for 19 days. Feb. 2nd 1998 through Feb. 20th 1998. The R -form of Family Environment Scale (Moos, 1974) was used in the analysis of family environment(Cronbach's Alpha =0.80). Questionnaires of Health Behavior in School-aged children used by the WHO in Europe(Aaro et al., 1986) and the ones developed by the Health Promotion Committee of the Western Pacific(WHO, 1995)(adapted by long Young-suk and Moon Young-hee(1996)) were used in the analysis of health behavior, as well documents on absences due to sickness, school health room-visits, levels of physical strength, height, weight and degree of obesity were used to determine health status. In next step, We used them with an $X^2$-test, t-test, Odds Ratio, and a 95% Confidence Interval. 1. In two dimensions of three, family-relationship (t=3.41, p=0.001) and system -maintenances(t= 2.41, p=0.0l6) the mean score of urban children were significantly higher than those of rural ones. In the personal development dimension however, there was little significant difference. Assorting family environment into 10 sub-fields and analyzing them, we recognized that urban children were superior to rural children in the sub-fields of expressiveness (t =3.47, p=0.001), conflict (t=0.48, p=0.001), active-recreational orientation (t = 1.97, p=0.049) and organization (t=4.33, p=0.000). 2. Referring to the Odds Ratios of urban-rural children's health behaviors, urban children set up more desirable behavior than rural children wear ing safety belts (Odds Ratio =0.32, p=0.000), washing hands after meals(Odds Ratio = 0.43, p= 0.000), washing hands after excreting (Odds Ratio = 0.39, p=O.OOO), washing hands after coming - home ( Odds Ratio = 0.75, p = 0.003), brushing teeth before sleeping(Odds Ratio =0.45, p=0.000), brushing teeth more than once a day (Odds Ratio =0.73, p=0.0l2), drinking boiled water (Odds Ratio = 0.49, p=0.000), collecting garbage at home(Odds Ratio=0.31, p=0.000) and in the school(Odds Ratio =0. 67, p=0.000). All these led to significant differences. As to taking milk(Odds Ratio = 1.50, p=0.000), taking care of eyesight(Odds Ratio=1.41, p=0.001) and getting physical exercise in(Odds Ratio = 1.33, p=0.0l9) and outside the school(Odds Ratio = 1.32, p=0.005), rural children had more desirable behavior which also revealed a significant difference. There was little significant difference in smoking, but the smoking rate of rural children(5.5%) was larger than that of urban children(3.9%). 3. Health status was analyzed in terms of absences, school health room-visits, levels of physical strength, and the degree of obesity, height and weight. Considering Odds Ratios of the health status of urban-rural children, the health status of rural children was significantly better than that of the urban ones in the level of physical strength(t=1.51, p=0.000) and the degree of obesity(t=1.84, p=0.000). The mean height of urban children ($150.4{\pm}7.5cm$) is taller than that of their counterparts($149.5{\pm}7.9$), which revealed a significant difference (t =2.47, p=0.0l4). The mean weight of urban children($42.9{\pm}8.6kg$) is larger than that of their counterparts($41.8{\pm}9.0kg$), which was also a significant difference(t=2.81, p=0.005). Considering the results above, we can recognize that there are significant differences in family environment, health behavior, and health status in urban-rural children. These results also suggestion ideas for health education. What we would suggest for the health program of elementary schools is that school health teachers should play an active role in promoting the need and importance of health education, develop the appropriate programs which correspond to the regional characteristics, and incorporate them into schools to improve children's ability to manage their own health management.

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일부 농촌지역 노인의 건강생활습관에 따른 기능적 건강상태의 변화 (Change of Functional Health Status according to Healthy Life-style of the Elderly Living in Rural Community)

  • 황병덕;이상원;문효정;이성국
    • 농촌의학ㆍ지역보건
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    • 제30권2호
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    • pp.151-165
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    • 2005
  • 농촌지역노인들이 평소 실천해온 건강생활습관이 기능적 건강상태의 변화에 미치는 영향을 분석하여 건강상태에 바람직하게 작용하는 건강생활습관요인들을 찾아내기 위한 목적으로 경상북도 성주군의 65세 이상 노인 중 8개보건진료소권역의 3개리에 거주하고 있는 노 1,295명을 대상으로 하여 1996년 10월 한달간 1차 조사를 실시하고 3년 10개월 후인 2000년 7월과 8월에 이들에 대한 2차 추적조사를 실시하였다. 추적된 대상자는 1,014명이었다. 건강생활습관의 경우 요인분석을 통해 6개의 요인 15항목의 생활습관 문항을 사용하였다. 1차조사시 고ADL과 고IADL이었던 자만 대상으로 하여 2차 조사시 건강수준의 변화여부를 종속변수로 하였다. ADL은 단순분석결과 남자는 일반적 특성 중 연령, 경제수준, 직업, 교육수준이, 여자는 연령과 경제수준이 건강상태의 변화에 유의한 관련성이 있었다. 다중 로지스틱 회귀분석의 결과 일반적 특성이 ADL의 변화에 유의한 변수로 남자는 연령과 교육수준이, 여자는 연령과 경제수준이었다. 건강생활습관으로는 남자에서 식이요인이, 여자에서는 식이요인과 사회 참여요인이었으며, 일반적 특성을 통제하였을 경우에는 남 여 모두 식이요인이 유의한 변수였다. IADL은 단순분석결과 남자는 일반적 특성 중 연령이, 여자는 연령과 교육수준이 건강상태의 변화에 유의한 관련성이 있었다. 다중 로지스틱 회귀분석의 결과 일반적 특성이 IADL의 변화에 유의한 변수로 남자는 연령이, 여자는 연령과 교육수준이었다. 건강생활습관으로 여자만 식이요인과 스트레스해소요인이었으며, 일반적 특성을 통제하였을 경우에도 여자만 식이요인과 스트레스해소요인이 유의한 변수였다. 결론적으로 65세 이상 노인인구의 기능적 건강을 유지하기 위해서는 올바른 식이습관과 적극적인 사회참여활동 그리고 스트레스해소 등의 건강 생활습관을 유지하도록 하는 방안이 강구되어야 한다. 이를 위하여 지역사회의 보건관련기관과 주민의 참여를 통한 보건교육 및 생활습관의 개선 작업들에 보다 많은 지원과 인력개발 등의 다각적 노력이 경주되어야 할 것이다.

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LA-ICP/MS를 이용한 담수 어류 이석 내 금속 원소 농도 분석 (Analysis of the Concentration of Metal Elements in Freshwater Fish Otolith Using LA-ICP/MS)

  • 박현우;윤숙희;박재선;임보라;이혜리;최종우
    • 생태와환경
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    • 제52권4호
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    • pp.324-332
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    • 2019
  • 본 연구는 Laser ablation ICP/MS (이하 LA-ICP/MS)를 이용한 환경오염 추적연구를 위하여 어류 내 이석을 분석하였다. 어류의 이석은 어류가 서식하는 환경에 영향을 받는 것으로 알려져 있어 국외에서는 이를 활용한 연구가 활발하나 국내에서는 이에 대한 연구가 미비한 실정이다. 그래서 본 연구에서는 환경오염의 지표로 사용되는 금속 원소의 성분 분석을 통하여 어류 이석을 이용한 환경오염 추적 가능성을 파악하고자 하였다. 또한 금속 원소의 성분 분석을 위해서는 전처리 과정을 줄여 분석 시간을 단축시킬 수 있는 것으로 알려진 LA-ICP/MS를 이용하였다. 시료채취는 연구지역과 배경지역으로 나누어 실험을 진행하였고, 실험 어종은 담수종인 잉어를 선정하였다. LA-ICP의 분석 최적 조건을 정립하기 위하여 이석 표준물질인 FEBS-1을 이용하여 9개 금속 원소(Li, Mg, Mn, Cu, Zn, Sr, Ba, Pb, U)의 정확도와 정밀도를 확인하였다. 정립한 조건을 이용하여 실제시료를 분석한 결과, 연구지역에서 채집한 어류 이석 내 금속 원소 성분의 총 농도가 2202.9 mg kg-1으로 배경 지역의 1086.3 mg kg-1보다 2.03배 높게 측정되었다. 원소별로는 Li과 U을 제외한 모든 원소가 연구 지역이 배경지역보다 높게 나타났다. 그리고 퇴적물 측정망 분석 자료와 비교한 결과, Zn, Pb, Cu가 두 지역의 퇴적물 금속 원소 농도 분포와 어류 이석 내 금속 원소 농도 분포 경향이 유사하게 나타났다. 이러한 결과로 보아 어류 내 이석은 퇴적물과 같이 환경오염원을 추적하는 데 활용할 수 있다는 것을 확인하였다.

노후적응에 관한 연구 - 생활만족도 및 가족의 교류도를 중심으로- (A study on the adjustment problems of the aged)

  • 서병숙
    • 대한가정학회지
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    • 제27권2호
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    • pp.133-148
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    • 1989
  • This study attempts of analyze empirically the living status of the elderly in Korea by finding out the problems of it in the family and by clarifying the influences of the family environmental variables and the values on the adjustment of the aged. To carryout the aim of this study, the causes and the patterns of the problems for the aged had been found out through the review of literature. Based on them the questionnaire was prepared including the questions of the values, family environmental vriables as well as the degree of satisfaction of thier liver and the extent of life interchange. The former variables were taken as independent and the latter were taken as dependent variables, so that the relationship between the two variables could be exemplified. The 400 aged over 60 living in Seoul and the other cities were selected through the purposive sampling and interviewed. The answers of the 376 respondents, 94% of the sample, were analyzed for this study. The following results have been found out through the various statistical analysis such as frequency distribution, chi-square test, pearson's correlation, analysis of variance and cluster analysis. At first, the results from the examination of the frequency distribution regarding the living status of the aged are; I) sixteen percent of the respondents living with their married offspring were receiving economical support, though they pointed out the problems of the extended family are the inconveniences with their children (60%) and simpleness (20%) of their livers. It seems that the aged in Korea are poor and have negative opinion on the relationship with their offspring even if they live in the same house. Secondly, it has been found out that the family environmental variables, especially such as sex, occupation, residence, education, level, living ability and the family type, play and important role not only on the degree of satisfaction of their liver but also on the extent of interchange of their lives. However, the variables such as religion and whether the spouse is alive or not do not play and important role. Thirdly, the reported main reasons of their delightness were healthy life (1.87%), the well-being of their offspring (2.08%), the spouse's long life (3.38%), religious activity (5.05%), the hobby activity (4.31%) and the participation in the social activity (5.05%). While, they mainly concern about the illness (1.98%), offspring (2.00%), econmic difficulties (3.39%), inharmonious home (3.81%) and the despicable treatment (3.81%). The respondents wer classified into two groups, they are dependent and independent, using cluster analysis. Health, social activity, offspiring, religion, couple's long life among the factors which lead them to be delighted were turned out to be statistically signhificant at 0.01 significance level between the two groups. As far as their worrisome matters are concerned, health and economic difficulties were significantly different between the two groups. Fourthly, regarding the life interchange, it has been proved that there is a statistically significant differences betwwen the two groups in the economic and the emotional satisfaction, help for ordinary life, status in the family, subjective and objective relationship with offspring, but not in economic dependency and the activity status. Fifthly, it has been noted that there is a high correlation between the degree of life's satisfaction and the extent of life interchange. On the basis of the results mentioned above, it could be concluded taht; i) The majority of the aged in Korea are not economically active, and thus they live with their married offspring even of they have a negative opinion on the subjective relationship with them. This can be pointed out as the main problem of the aged and thus it needs to be studied further. ii) the environmental variables such as age, sex education level, family type and occuption (which can not be changed by their effrot) turned out to give an important effect on the extent of the life interchange among the aged. iii) The respondents who are identified as independent group have a higher degree of life satisfaction and family status than the group identified as defendent. Thus, it can be inferred that it is possible for them to adjust their life by making an effort to modify themselves. iv) The high correlation between the extent of life interchange and the degree of life satisfaction indicates that the elderly themselves can adjust in order to obtain the higher degree of life satisfaction. Therefore, the following suggestions are derived from this study. First of all, the aged should try to be psychologically independent. Second, they need to control themselves in order to achieve self-assurance. Third, the community have to prepare a program of self-development for the aged. Fourth, the social welfare policy that can solve the problem of illness and poverty of the elderly should be introduced, so that their minimum requirements can be satisfied.

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HDTV 응용을 위한 10비트 200MS/s 75.6mW $0.76mm^2$ 65nm CMOS 파이프라인 A/D 변환기 (A 10b 200MS/s 75.6mW $0.76mm^2$ 65nm CMOS Pipeline ADC for HDTV Applications)

  • 박범수;김영주;박승재;이승훈
    • 대한전자공학회논문지SD
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    • 제46권3호
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    • pp.60-68
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    • 2009
  • 본 논문에서는 HDTV와 같이 고해상도 및 고속의 동작을 동시에 요구하는 고화질 영상시스템 응용을 위한 10비트 200MS/s 65nm CMOS ADC를 제안한다. 제안하는 ADC는 고속 동작에서 저 전력 소면적 구현에 적합한 4단 파이프라인 구조를 기반으로 설계되었으며, 입력단 SHA 회로에서는 1.2V의 낮은 단일 전원 전압에서도 높은 입력 신호를 처리하기 위해 4개의 커패시터를 기반으로 설계하여 $1.4V_{p-p}$의 입력 신호를 ADC 내부 회로에서는 $1.0V_{p-p}$으로 낮추어 사용할 수 있도록 하였다. 또한 높은 전압이득을 갖는 증폭기를 필요로 하는 SHA와 MDAC1은 출력 임피던스가 감소하는 65nm CMOS 공정의 제약 사항을 극복하기 위해 통상적인 2단 증폭기 대신 3단 증폭기 구조를 기반으로 설계하였으며 200MS/s 높은 동작 속도를 고려하여 RNMC 및 multipath 주파수 보상기법을 추가하여 설계하였다. 전력 소모 최소화를 위해 스위치 기반의 바이어스 전력최소화 기법을 sub-ranging flash ADC에 적용하였고, 기준 전류 및 전압 발생기를 온-칩으로 집적하는 동시에 외부에서도 인가할 수 있도록 하여 시스템 응용에 따라 선택적으로 사용할 수 있도록 하였다. 제안하는 시제품 ADC는 65nm CMOS 공정으로 제작되었으며, 측정된 DNL 및 INL은 10비트 해상도에서 각각 최대 0.19LSB, 0.61LSB 수준을 보이며, 동적 성능으로는 150MS/s와 200MS/s의 동작 속도에서 각각 54.4dB, 52.4dB의 SNDR과 72.9dB 64.8dB의 SFDR을 보여준다. 시제품 ADC의 칩 면적은 $0.76mm^2$이며, 1.2V 전원 전압과 200MS/s의 동작 속도에서 75.6mW의 전력을 소모한다.

남한강류역(南漢江流域)의 호르텐스극구흡충(棘口吸蟲) 감염실태(感染實態)와 생활사(生活史)에 관(關)한 연구(硏究) (Experimental and epidemiological studies on the life cycle of Echinostoma hortense Asada, 1926(Trematoda: Echinostomatidae))

  • 안영겸;양룡석
    • Parasites, Hosts and Diseases
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    • 제24권2호
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    • pp.121-136
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    • 1986
  • Recently there have been some reports on human infections of Echinostoma hortense in Korea. It was found that a few species of freshwater fishes were playing the role of the second intermediate host of E. hortense. However, molluscan intermediate host has not been identified yet in Korea. The present study aimed to establish the life cycle of E. hortense in laboratory. Experimental studies such as egg production from the rat, development of the eggs in vitro, exposure of miracidia to freshwater snails, shedding pattern of cercariae from infected snails, morphology of cercariae, cercarial infection to the second intermediate host and infection of metacercariae to the definitive hosts were done. In addition, epidemiological surveys on the infection status in inhabitants and house rats, and on the natural infection of larval echinostomes in the snails and fishes were carried out along the South Hangang-river. The results obtained were as follows: 1. The eggs deposited from adults in physiological saline were cultivated at room temperature($20{\sim}24^{\circ}C$). The miracidia were firstly observed on 8 days after cultivation, and 85.5% of the eggs contained the mature miracidia on 11 days after cultivation. More than 90% formed the miracidia when cultivated at temperature $22{\sim}27^{\circ}C$. Hatching of the miracidia began on 12 days after cultivation and continued for a week. The size of the miracidia was $103.0{{\times}}51.4{\mu}m$ in average. The motility of the miracidia were active up to 8 hours after shedding, but they were all dead within 10 hours after shedding. 2. A freshwater snail, Radix auricularia coreana was cultivated in aquaria. A hatched $F_1$ snails from the egg masses were exposed to 20 miracidia respectively. Escape of cercariae started on 15 days after infecton. Radix auricularia coreana was experimentally identified as the first intermediate host of E. hortense in Korea. 3. Cercarial shedding started on $15{\sim}20$ days after infection by snail, continued for about 10 days (8.8 days in average). Infected snails were dead within 32 days after the miracidial infection. About 1,335 cercariae($328{\sim}1,994$) per snail were shed in its life, and 119 cercariae in average per snail per day were shed. The cercariae were motile for more than 24 hours, and then squirming at the bottom until death. The body and tail sizes of cercariae were $356{\times}186{\mu}m$ and $510{\times}68{\mu}m$ in average, respectively. The rediae parasitized in the snail hosts were found mainly around the pericardial regions, and their size was $1,575{\times}258{\mu}m$ in average. The numbers of developing cercariae in a mature redia were 14 in average ($7{\sim}20$ in range). The numbers of rediae in a snail were 102 in average on 15 days after miracidial infection and 221 in average on 28 days. 4. Three uninfected Misgurnus anguillicaudatus, less than 6.5cm long were used in for the cercarial infection. They were all exposed with 755 cercariae, and examined at 5-day intervals starting from 10 days after infection. All the fishes were infected with metacercariae of E. hortense and a total of 275 was found infected(36.4%). The metacercariae were fed to rats and the adult worms were obtained on 15 days after infection. 5. The infected rats began to deposit the eggs on 11 days after infection. The number of eggs deposited per day per worm (EPD/worm) was $400{\sim}500$ on 3 weeks after infection and was increased to $1,000{\sim}1,500$ on 4 to 17 weeks, then decreased to 800 on 21 weeks after infection. 6. A total of 745 stool specimens collected from 576 male and 169 female residents of 8 different villages along South Hangang basin was examined. Out of 745 specimens, the eggs of Echinostoma sp. were found in 2 cases (0.3%). Of 34 house rats one showed egg-positive (2.9%). 7. Total 971 Radix auricularia coreana collected from 7 sampling stations were examined for shedding of cercariae. Three snails (0.3%) shed the cercariae of E. hortense. A total of 119 out of 542 freshwater fishes (22.0%) had the metacercariae of E. hortense. The fishes parasitized with the metacercariae were 4 out of 14 examined species. The infection rates of 4 species were 34.1% (106 out of 311) in Misgurnus anguillicaudatus, 30.4% (7 out of 23) in Misgurnus mizolepis, 4.3% (2 out of 46) in Moroco oxycephalus and 22.2% (4 out of 18) in Odontobutis obscura interrupta. In summarizing the above results, the first intermediate host of E. hortense was found as Radix auricularia coreana in Korea. Also, it took about 46 days for the shortest completion of a life cycle of E. hortense in summer; that is, 10 days for miracidial development in eggs, 15 days for cercarial development in the snail, about 10 days for metacercarial development in the second intermediate hosts, and 11 days for the maturation as the adults in the definitive hosts. The natural infection rates of E. hortense in the intermediate hosts were relatively high but those in the definitive hosts were low in the middle areas of South Hangang basin.

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하계 생육기 동안 Zoysiagrass와 Creeping Bentgrass의 비구조적 탄수화물 함량의 비교 (Comparison of Non-structural Carbohydrate Concentration Between Zoysiagrass and Creeping Bentgrass During Summer Growing Season)

  • Kim, Dae-Hyun;Jung, Woo-Jin;Lee, Bok-Rye;Kim, Kil-Yong;Kim, Tae-Hwan
    • 한국초지조사료학회지
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    • 제22권2호
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    • pp.145-152
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    • 2002
  • Zoysiagrass [Zoysia marella (L.) Merr.]와 creeping bentgrass (Agrostis palustris Huds)에서 고온 스트레스에 대한 탄수화물대사 반응을 규명하기 위해 4월부터 9월까지의 식물체내의 탄수화물 대사산물의 변화를 비교 분석하였다. 각 초종의 샘플은 1998년 조성된 무안 Country Club의 green과 fairway에서 채취하였다. Creeping bentgrass의 지상부 수량은 6월부터 8월까지 점차 감소하였고 이후 회복되었다. 반면 zoysiagrass의 지상부 수량은 크게 변하지 않았다. Creeping bentgrass의 엽록소 함량은 7월까지 zoysiagrass의 엽록소 함량에 비해 현저하게 높았고, 그후 7월부터 8월까지 43%의 감소를 보였다. 가용성 당의 경우 zoysiagrass은 전 시험기간동안 creeping bentgrass보다 높게 유지되었다. Zoysiagrass의 가용성 당은 4월부터 5월사이 약 58%의 증가를 보였고, 이후 8월까지 유의적인 변화가 없었다. Creeping bentgrass의 가용성 당은 7월까지 다소 증가한 후, 8월에 급격하게 감소하였다 Zoysaigrass의 Starch의 농도는 4월부터 5월까지 증가한 후 9월까지 지속적으로 감소하였다. Creeping bentgrass의 경우 starch와 fructan 농도는 공히 6월과 7월 사이의 높은 축적 및 7월과 8월 사이의 급격한 감소하는 특이점을 보였다. 이상의 결과들은 zoysiagrass 보다 creeping bentgrass가 6월과 8월 사이의 고온 스트레스를 많이 받고 있음을 보여주며, 이 기간 중 creeping bentgrass의 비구조적 탄수화물의 활발한 축적과 가수분해는 고온 스트레스와 밀접한 관련이 있음을 잘 나타내고 있다.