• Title/Summary/Keyword: 교란 요인

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Geographical Distribution and Ecology in Microhabitats of the Rare Species, Pulsatilla tongkangensis Y.N. Lee et T.C. Lee (희귀종인 동강할미꽃(Pulsatilla tongkangensis Y.N. Lee et T.C. Lee)의 지리적 분포와 미소생육지의 생태)

  • Oh, Hyun-Kyung;Lee, Kyungeun;Lee, Yonghak;Choung, Yeonsook
    • Korean Journal of Ecology and Environment
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    • v.47 no.spc
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    • pp.74-82
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    • 2014
  • A perennial plant species of Ranunculaceae, Pulsatilla tongkangensis is a very rare species only found in limestone vegetation of South Korea. It is not only rare but also has great value as a horticultural resource, thus resulting in serious problems of overexploitation and habitat disturbance. For the conservation of the rare species and its development as a resource, the study was conducted with the following three aims: first, to investigate any new geographical distribution of the species; second, to identify the site condition and vegetation structure of its habitat; and third, to compare the ecology of P. tongkangensis in other microhabitats such as rock, slope and ridge area. A new distribution was found in limestone vegetation at Danyang-gun, Chungcheongbuk-do. It was, therefore, confirmed that the distribution of P. tongkangensis exactly coincides with the area of distribution of limestone, indicating a possibility that the species might be a calcicole. 87% of the microhabitats found in rocks. Compared to P. tongkangensis, at ridges or slopes, number of P. tongkangensis plants were few in rocks. It is possibly due to the lack of microhabitats that could settle in rocky areas. Once established on rocks, however, plants grew large enough to flower with higher number of leaves and flowers per plant, resulting in higher flowering rate on rocky areas. Cracks in/between rocks are likely to be safe places for the plants with favorable light conditions, abundant fine particles to root down and reduced competition for resources. Yet, further research is necessary in terms of determining whether the species is indeed a calcicole, whether other limiting factors work in its establishment stage, and genetic diversity exists in the population.

An Experimental Study on the Water Temperature Sensitivity of Exotic Fishes (외래어종의 수온 민감성에 대한 실험 연구)

  • Son, Minwoo;Park, Byeoung Eun;Byun, Jisun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.483-483
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    • 2018
  • 우리나라 하천 생태계에서 외래어종은 토착 어류의 개체수를 빠르게 감소시키고 서식처에서 우점종이 되어 생태계 교란을 야기하고 있다. 이러한 현안의 문제점을 해결하기 위해 외래어종과 관련된 많은 연구가 진행되고 있다. 본 연구는 우리나라 대표적 외래어종인 배스와 블루길을 대상으로 수온에 따른 서식처 형성을 관찰한다. 그 후 계절별로 형성된 서식처 안에서 수온을 조절하여 외래어종의 생태환경에 따른 민감성을 분석하는 것을 목적으로 수행하였다. 실험실 연구를 진행하는 동안 외래어종이 서식처를 형성할 때 민감하게 반응하는 수온 차가 계절에 따라 달라짐을 발견하였다. 이 사실을 증명하기 위해 농업용 저수지로부터 채집한 배스와 블루길을 길이 12 m, 깊이 0.6 m, 폭 1 m의 하천과 유사한 자연적 환경이 갖추어진 수조에 이식한 후, 외래어종이 서식처를 형성할 때 계절에 따라 어떻게 반응하는지 면밀히 관찰하였다. 수조를 3개의 구역으로 나누어 좌측 끝단을 히터를 설치한 온수대, 우측 끝단을 냉각기를 설치한 냉수대, 중앙은 온도 조절장치를 설치하지 않은 중수대로 구분하여 실험하였고 계절 마다 수온을 조절하며 수온 차와 서식처 형성의 상관성 분석이 진행되었다. 실험 진행 시 수온을 제외한 수조 안 환경은 동일하게 유지하였다. 실험 결과, 동계에는 실험실 수조의 평균 수온이 $12.88^{\circ}C$이고 어류는 각 구간별 수온의 차이가 $1^{\circ}C$ 이하에도 민감하게 반응하며 조금이라도 수온이 높은 구역에 서식처를 형성하였다. 춘계에는 평균 수온 $16.15^{\circ}C$가 되면서 어류가 온수대에 서식처를 형성하기는 하나 각 구간별 $1^{\circ}C$ 정도의 차이에는 중수대까지 서식처를 형성하였다. 즉 동계보다는 수온 차이에 둔감하게 반응하는 특성을 보였다. 또한 춘계에서 하계로 넘어가는 과도기에 수조의 평균 수온이 $21^{\circ}C$로 올라가자 외래어종은 각 구간별 수온 차이와는 관계없이 이미 서식처로 형성했던 온수대를 넘어 수조 전체에 좀 더 확산된 형태의 서식처를 형성하였다. 하계에는 수조의 평균 수온이 $25.67^{\circ}C$였으며 수온을 조절하여 관찰한 결과 외래어종은 약 $24^{\circ}C$ 수온보다 낮은 냉수대에 서식처를 뚜렷하게 형성하는 모습을 보였다. 즉 외래어종은 $20{\sim}24^{\circ}C$ 정도의 수온에 서식처를 가장 선호 하며 동계에는 수온이 가장 높은 곳, 하계에는 가장 낮은 곳에 형성하는 것으로 판단된다. 실험을 진행하는 동안 수조 내 구역의 구분을 위해 공통으로 설치된 가림판 부근에 외래어종의 군락이 형성된 것을 통해, 향후에는 외래어종의 서식처 형성과 장애물과 같은 지형적인 요인이 미치는 영향에 관한 연구가 필요할 것으로 판단된다.

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Soil Organic Carbon Determination for Calcareous Soils (석회암 유래 토양의 토양유기탄소 분석법 연구)

  • Jung, Won-Kyo;Kim, Yoo-Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.39 no.6
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    • pp.396-402
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    • 2006
  • Soil organic carbon has long been considered as the most critical factor to evaluate the soil quality, fertility, and fertilizer prescription. In addition, soil organic carbon may impact on greenhouse gas effects and global warming. Because of that, the management of soil organic carbon is increasingly important not only for improving soil quality but also for managing soil as a greenhouse gas source. Both wet and dry combustion have been used to determine soil organic carbon. Many benefits, such as automation and less labor, could the dry combustion method become more popular. Inorganic form of carbon could overestimate soil organic carbon when the dry combustion method was applied. Determination of soil inorganic carbon may contribute to the improved accuracy of soil organic carbon analysis using dry combustion method. Objectives of this research were 1) to develop soil inorganic carbon determination method using modified digital pressure calcimeter and 2) to evaluate soil organic carbon from calcareous soils using the dry and wet combustion method. Results showed that the significant linear relationship was found between soil inorganic carbon content and pressure calcimeter output. Inorganic carbon ranged from 22% to 28% of total carbon in the calcareous soil samples. Soil organic carbon content by dry combustion for calcareous soil was determined by subtracting inorganic carbon measured by the digital pressure calcimeter from total carbon. Soil organic carbon determined by dry combustion method was significantly correlated with that by wet combustion method. In conclusion, the digital pressure calcimeter may use to improve soil organic carbon determination for the calcareous soils by subtracting of soil inorganic carbon from total carbon determined by dry combustion method.

Inhibitory Effects of Illicium verum Hooker fil. Dichloromethane Fractions on Adipocyte Differentiation (팔각회향 dichloromethane 분획물에 의한 지방세포 분화 억제 효과)

  • Jeong, Hyun Young;Jeong, In Kyo;Kim, Nam Ju;Yun, Hee Jung;Park, Jung Ha;Kim, Byung Woo;Kwon, Hyun Ju
    • Journal of Life Science
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    • v.29 no.4
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    • pp.447-454
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    • 2019
  • Fat accumulation in adipocytes occurs through the process of adipogenesis in which preadipocytes differentiate into adipocytes. Obesity is a metabolic disorder caused by excessive accumulation of fat in the body, which increases the incidence of cardiovascular diseases, hypertension, type 2 diabetes, hyperlipidemia, and various cancers. Recently, inhibition of adipocyte differentiation was shown to be a potential antiobesity strategy. In this study, the inhibitory effect of dichloromethane fractions from Illicium verum Hooker fil. water extract on the differentiation of 3T3-L1 preadipocytes to adipocytes was investigated. Dichloromethane fractions from I. verum Hooker fil. significantly inhibited adipocyte differentiation when applied during the adipocyte differentiation process, as assessed by measuring fat accumulation using Oil-red O staining. In addition, dichloromethane fractions from I. verum Hooker fil. reduced important adipogenic transcription factors, such as CCAAT/enhancer binding protein ${\alpha}$ ($C/EBP{\alpha}$), $C/EBP{\beta}$, and peroxisome proliferator activated receptor ${\gamma}$ ($PPAR{\gamma}$). The expression of FAS and LPL, which are terminal differentiation markers of mature adipocytes, was also reduced in the 3T3-L1 adipocytes treated with dichloromethane fractions from I. verum Hooker fil. In addition, the treatment significantly inhibited mitotic clonal expansion, which is essential for adipocyte differentiation, by arresting the G1 phase of the cell cycle. Taken together, these results suggest that dichloromethane fractions from I. verum Hooker fil. may be a natural material with antiobesity effects.

The Influence of Pre-service early childhood Teacher's Empathetic Ability and Interpersonal Competence on Teacher's Efficacy (예비유아교사의 공감능력과 대인관계 유능성이 교사효능감에 미치는 영향)

  • Choi, In-Sook;Park, Yu-Mi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.454-462
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    • 2018
  • This study examines the influence of pre-service early childhood teacher's empathy and interpersonal competence on teacher efficacy. The subjects of this study include 358 pre-service early childhood teachers. The instruments used in this study were the emotional empathy scale, interpersonal competence questionnaire (ICQ) and the teacher efficacy scale. Collected data was analyzed using the SPSS program. In order to determine the general background of the pre-service teachers, the frequency and percentages were used. For examination of empathetic ability, interpersonal competence and teacher efficacy of pre-service early childhood teachers, a descriptive statistics analysis was conducted. In addition, in order to assess the relationship among empathetic ability, interpersonal competence and teacher efficacy of pre-service early childhood teachers, Pearson's correlation analysis was conducted. Lastly, for the examination of the effects and relative explanation of empathetic ability, interpersonal competence and teacher efficacy of pre-service early childhood teachers, multiple regression analysis was conducted. The results of this study were as follows: first, pre-service early childhood teachers were shown to have higher empathetic ability, interpersonal relationships and teacher efficacy rates than average. Second, there was a positive correlation among empathetic ability, interpersonal competence and teacher efficacy of pre-service early childhood teachers. Third, teacher efficacy of pre-service early childhood teachers was influenced by their empathetic ability and interpersonal competence. The results of this study suggest that teacher efficacy improvement programs for pre-service early childhood teachers should consider their empathetic ability. Also, study results emphasize the necessity of empathetic ability and interpersonal relationship improvement program for pre-service early childhood teachers.

Effect of Resilience on Academic Burnout of Nursing Students (간호대학생의 리질리언스가 학업소진에 미치는 영향)

  • Lee, Eunha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.178-187
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    • 2019
  • This study was to identify the effect of resilience on academic burnout of nursing students. The participants were 300 students of nursing college located in C do, Korea through a questionnaire. Data were collected from November 1 to 16, 2018. The collected data were complied using the SPSS/WIN 24.0 statistic program with Paired t-test, ANOVA, Pearson's Correlation coefficient, Multiple Regression. The results were as follows. The mean scores were resilience $61.40({\pm}12.96)$, academic burnout $41.49({\pm}7.50)$ and a statistically significant relationship between resilience and academic burnout (r=-.512, ${\rho}<.001$). Multiple regression analysis revealed that academic burnout of nursing students was significantly affected by satisfaction of nursing major(${\beta}=.380$, ${\rho}<.001$), health status(${\beta}=.171$, ${\rho}=.040$), resilience(${\beta}=-.333$, ${\rho}<.001$) and The coefficient of determination for these factors, $R^2$ showed an explanation force of 41.0%. Resilience was associated with lower levels of academic burnout. These findings suggest that it is necessary to develop a nursing educational program in order to recognize the importance of developing resilience and to manage the academic burnout.

The Study on the modernism characteristics of melodrama in the 1930s (1930년대 멜로드라마의 모더니즘적 특성 연구)

  • Sim, Sang-gyo
    • (The) Research of the performance art and culture
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    • no.35
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    • pp.203-227
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    • 2017
  • In this thesis, I examined the characteristics of modernism in this work, focusing on the melodrama "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')", which was popular in the 30s when the consciousness of modernity was overflowing. There has never been an example of a connection between modernism and drama in the 1930s. The characteristic of modernism is clearly embedded in the representative drama of "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')" at that time. In the title "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')". 'Don' reveals modern elements. 'Love' can be seen as revealing melodramatic elements. The flair of modern art, which is a background to reveal modern elements, is spread throughout the works. Hongdo fails to complete the relationship with his family, as well as with the couple. It became a person who accepted the modernistic phenomenon by showing the domination of matter. While the typical method of constructing conflicts in the pre-modern narrative works is horizontal and sequential, it can be said that it was in the form of a train station, while the post-modern era of narrative conflict formation from the 30s forms a plurality of conflicts simultaneously, can do. The fear of the ordinary people who see the reality that urban and western values are already rampant by attempting new contents that lead the change of values in "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')" became a factor to transfer into internal conflict again.

Identification of Freshwater Fish Species in Korea Using Environmental DNA Technique - From the Experiment at the Freshwater Fish Ecological Learning Center in Yangpyeong, Gyeonggi Do - (환경DNA 기술을 이용한 국내 담수어류종 탐지 가능성 - 경기도 민물고기생태학습관 중심으로 -)

  • Kim, Gawoo;Song, Youngkeun
    • Journal of Environmental Impact Assessment
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    • v.30 no.1
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    • pp.1-12
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    • 2021
  • This study focused on verifying the identification of freshwater fish species in Korea using Environmental DNA (eDNA) technique. The research of DNA is increasing in the field of ecology, since this is more sensitive of identify rather than traditional investigation method. Which is difficult to detect species hidden in water and be easily influenced by diverse factors (sites, bad weather, researchers and so on). We applied the pilot test in aquarium (Freshwater Fish Ecological Learning Center in Yangpyeong, Gyeonggi Do), where freshwater fish species are inhabits. We conducted to sampling and analyzing the sixteen water samples (50 species from 7 orders and 13 families) using MiFish primer set. The results showed that 45 species (90%) was investigated by eDNA. It highlight that eDNA with universal primer is possible to detect freshwater fish species of Korean. However, the errors on species identification seems to be caused by the primer that be not suited perfectly and the pollution such as aquarium, sampling collectors.

The association between body composition and bone mineral density in subjects aged 50 years or older in men and postmenopausal women in Korea

  • Cho, Jeong-Ran
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.8
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    • pp.209-220
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    • 2021
  • The effect of body composition such as lean mass and fat mass on bone mineral density (BMD) is complex and still controversial. In this study, we investigated the relationship between body composition and bone mineral density using nation-wide data from 2008 to 2011 Korea National Health and Nutrition Examination Survey (KNHANES) in 2,139 men and 2,193 postmenopausal women aged 50 years or older. Subjects with history of medication for osteoporosis or with diseases or malignancy affecting bone metabolism were excluded. Data of anthropometric measurements and demographic characteristics were collected by trained examiner. Fasting blood sample was obtained for blood chemistry analysis. BMD of the lumbar spine, total femur, and femoral neck, and body composition such as total lean mass (TLM), total fat mass (TFM), truncal fat mass (TrFM) were measured using dual-energy X-ray absorptiometry (DXA). There were significant positive correlations between body composition indices such as lean mass and fat mass with BMD. In multiple regression analysis, TLM was positively associated with BMD after adjusting age, body mass index, monthly house income, education level, physical activity, daily calcium intake and vitamin D concentration in both men and postmenopausal women. BMD at lumbar spine and femur in lowest quartile of TLM was significantly lower than other quartiles after adjusting those confounding factors in both gender. TrFM was negatively associated with total femur BMD in male and femur neck BMD in postmenopausal women after adjusting confounding factors. In conclusion, TLM is very important factor in maintaining BMD in subjects aged 50 years or older in men and postmenopausal women.

Think about Having Children : A Study on Childbirth and Parenting (자녀 출산과 양육에 대한 고찰)

  • Lee, Jeung Gwan
    • Journal of Christian Education in Korea
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    • v.65
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    • pp.55-80
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    • 2021
  • This study attempted to find a Christian religious alternative to the seriousness of the problem of low birth rate which has become a national and social problem, and its alternative. Korea is a low birth rate country. The phenomenon of low birth rate and childbirth avoidance is a reality that not only are national problems but also Korean churches are experiencing serious problems, and will continue to affect them. It will affect the church in four major ways. First, is a sharp decline in the number of members. Second, is the decline of Sunday schools. Third, various family problems and generational conflicts will arise. And it brings problems such as a crisis of faith among members. Young people living today have an unconventional attitude toward marriage, childbirth, and parenting. But for Christians, childbirth is a way of living in that God blessed us to "be fruitful, multiply, and fill the earth." In other words, childbirth must be recognized as a blessing from God, not a human decision. Therefore, we must know how precious the fetus is in front of God and that it is a precious life. Thus, we should be interested in how to nurture the life God has given. To do so the church's role is education is to shape the value of life from a biblical perspective. Therefore the church needs to see how the Christian faith of young and married couples who are about to marry, give birth, and raise children, affects the childbirth and rearing of children. And it is necessary to study what the role of church and Christian education is to solve the problem of low birth rate and to suggest alternatives. For this study, we will first identify the factors of low birth rate. Then we will confirm childbirth and the blessing of God through the Bible. Finally, the role of the church in low birth rate and educational alternatives will be presented.