An ecological study of river otters(Lutra lutra) in Geoje island of Korea

In the late 1950s, population of river otter was continuously declined. Many different explanations for this decline have been presented; e.g. hunting, habitat destruction and indirect or direct influences of eutrophication, acidification and toxic chemicals. Environmental pollution is a world-wide problem, heavy metals belonging to the most important pollutants recently. The progress of industries and dam construction has led to increase emisson of pollutants into ecosystem. In this study, the concentrations of fourteen metals(Cr, Cd, Pb, Ni, Zn and so on) have been determined. Spraints were collected monthly along the Gucheon(a total number of spraints=167) and Yeonchocheon(a total number of spraints=61), Geoje island, January to December, 2004. Metal concentrations were measured by ICP-AES. Lead concentrations were higher at upper stream in two reservoirs(7.02±0.91㎍/g, 1.60±0.88㎍/g, respectively) The high concentration of lead may be partly associated with agricultural activities. The concentrations of chrome, cadmium, lead of Gucheon and chrome of Yeonchocheon tended to increase by season, especially those were the highest in winter. The river otter is a top predator of most aquatic food chains. This makes otters good integrator of their aquatic environment and a useful surrogate species for determining both wildlife and human chemical exposure and potential harmful effects.;Eurasian otter(Lutra lutra) is an endangered wildlife species that population size is declining in Korea. To manage and conserve habitat for otters, it is curcial to understand which habitat components affect habitat preference for otters. The objectives of this study were to analyze otter habitat characteristics with land-cover map. I investigated otter spraints and sprainting site in Geoje Island from January to December, 2004. with GPS coordinates. The analysis of otter habitat use pattern was used by Arcview ver. 3.2 with 1: 25,000 Topology Map and field data. The results meant that otter habitat use was strongly related to riparian vegetation, dam or river construction and human interferences(presence /absence of residential area, commercial area and public facilities). In this study, Gucheon has a high denstiy of riparian vegetation and unconfined channels. Yeonchocheon was being under construction at lower stream so it limited otters' prey use and migration. This study suggests that searching for suitable habitat conditons for otter is essential in trial for conservation or trans-location.;The population density of the Eurasian otter(Lutra lutra) in Korea has been decreased. The main factor of this decline is the loss of habitat. To address the habitat pattern eight microhabitat variables were used: habitat condition(river or dam), waterside pattern, flow velocity, river width, river depth, bank treatment, water use and pollution source. Surveys were conducted on a monthly basis, from January to December, 2004. in Geoje island of Korea. The relationship between the number of spraint and habitat use pattern was evaluated by using GLM(Generalized linear model). Significant correlations were recorded between otter spraints and habitat condition, pollution source, flow velocity and river width. Otters selected dam area that was assumed high in water level. The narrower(2-5m) and slow velocity(5~30m/s) parts of the stream were preferred. Otter habitat also seems to be affected to living pollution and human disturbance. Dam condition was related to otters' preferred habitat of Gucheon, crossboard of bank treatment types was significant in Yeonchocheon. In this study the relationship between habitat situations and its use was measured. This is essential in order to determine which factors may be limiting the present otter population along the river ecosystem and thus help set up an effective conservation strategy.목차 Chapter Ⅰ 수달 배설물을 이용한 중금속 및 미량원소 분석을 통한 하천 생태계 연구 = 1 Abstract = 2 Ⅰ. 서론 = 3 Ⅱ. 연구지역 및 방법 = 5 2.1. 연구 지역 = 5 2.2. 실험 재료 = 7 2.3. 중금속 분석 = 9 2.4. 통계분석 = 11 Ⅲ. 결과 = 12 3.1. 구천 및 연초천의 중금속 및 미량원소의 연평균 농도 = 12 3.2. 구천 및 연초천의 월별 오염 = 16 3.3. 구천 및 연초천의 권역별 오염 = 19 3.4. 구천 및 연초천의 계절별 오염 = 23 3.5. 구천 및 연초천의 권역에 대한 계절별 금속 오염 = 27 3.6. 기존 문헌과의 비교 = 33 Ⅳ. 고찰 = 34 Ⅴ. 참고문헌 = 36 Chapter Ⅱ 토지피복도를 활용한 수달의 서식지 이용 분석에 관한 연구 = 41 Abstract = 42 Ⅰ. 서론 = 43 Ⅱ. 연구지역 및 방법 = 45 2.1. 연구 지역 = 45 2.2. 실험 재료 = 45 2.3. 서식지 분석 = 47 Ⅲ. 결과 = 49 3.1. 수달의 서식지와 연평균 토지피복도 관계 = 49 3.2. 월별 서식지 이용 현황 = 53 3.3. 권역별 서식지 이용 현황 = 56 Ⅳ. 고찰 = 62 Ⅴ. 참고문헌 = 64 Chapter Ⅲ 수달 배설물을 통한 서식지 이용 유형 분석에 관한 연구 = 67 Abstract = 68 Ⅰ. 서론 = 69 Ⅱ. 연구지역 및 방법 = 71 2.1. 연구 지역 = 71 2.2. 실험 재료 = 71 2.3. 서식지 분석 = 73 2.4. 데이터 분석 = 75 Ⅲ. 결과 = 76 3.1. 구천 및 연초천의 서식지 이용 현황 = 76 3.2. 권역별 서식지 이용 현황 = 81 3.3. 계절별 서식지 이용 현황 = 83 Ⅳ.고찰 = 85 Ⅴ.참고문헌 = 88 Chapter Ⅳ 종합 결론 = 9

40마리의 개에서 동종 지방 조직 유래 개 중간엽 줄기 세포의 정맥 내 투여의 안전성 평가

학위논문(석사)--서울대학교 대학원 :수의과대학 수의학과,2020. 2. 윤화영.To evaluate the side effects of mesenchymal stem cell (MSC) transplantation by intravenous infusion of allogenic MSCs in dogs and to examine the long-term safety including tumorigenesis. The study conducted a retrospective analysis of various clinical assessments such as physical examination, blood tests, and radiography and monitored the formation of neoplasms, during the 6-month follow-up period in 40 client-owned dogs that received intravenous infusion of adipose-tissue derived MSCs (AT-MSCs) for the treatment of various underlying diseases between 2012 and November 2018. No significant side effects of the MSC therapy were detected by clinical assessment, blood tests, and radiographic examination in the 6-month follow-up period after the first MSC treatment, and no new neoplasms were observed during this period. This study is the first to evaluate the long-term (≥ 6 month) safety aspects and risk of tumorigenesis for intravenous allogenic AT-MSC infusion. These results suggested that the allogenic AT-MSC infusion does not have a tumorigenic potential in dogs and confirmed that MSC therapy can be a useful and a relatively safe therapeutic approach in canines.줄기세포 치료는 여러 질환에서 치료 효과와 임상적 적용에 대해 수 년 동안 연구되어 왔으며, 최근 수의학에서도 그에 관련된 연구들이 발표되었다. 하지만, 개에서 종양 형성능을 포함한 장기적 안전성을 평가한 보고는 거의 없다. 본 연구에서는 개에서 동종 지방유래 중간엽 줄기 세포의 정맥 내 투여의 부작용을 평가하고 종양 형성을 포함한 장기 안전성을 조사하고자 하였다. 2012년에서 2018년 사이에 기저 질환 치료를 위해 서울대학교 동물병원 내과에 내원한 40마리의 개에서 정맥 내로 줄기세포 투여 후 신체검사, 혈액검사, 영상검사 등의 다양한 임상적 평가가 이루어졌으며, 신생 종양 형성 여부를 6개월의 추적 기간 동안 조사하였다. 첫 번째 줄기세포 투여 후 6 개월의 추적 기간 동안 임상 평가, 혈액 검사 및 방사선 검사 결과 심각한 부작용은 발견되지 않았으며, 이 기간 동안 새로운 신생물은 관찰되지 않았다. 본 연구는 정맥 내 동종 지방유래 중간엽 줄기세포 주입에 대한 6개월 이상의 장기적 안전성 및 종양 발생 위험성을 평가한 첫 연구이다. 또한 동종 지방유래 중간엽 줄기세포 주입 시 개에게 종양 형성능이 확인되지 않았으며 줄기세포 치료는 개에서 유용하고 비교적 안전한 치료 방법이 될 수 있음을 시사하였다.1. Introduction. 1 2. Material and Methods 2 2.1. Study population 2 2.2. Isolation and characterisation of canine AT-MSCs 2 2.3. Administration of canine AT-MSCs 3 2.4. Clinical assessment 4 2.5. Blood tests 4 2.6. Thoracic radiograph and abdominal sonographyy 5 3. Results 6 3.1 Characterization of canine AT-MSCs 6 3.2. No changes were observed between the various clinical parameters tested before and after the MSC therapy 6 3.3. No risk of tumorigenesis was observed after MSC therapy 7 4. Discussion. 8 5. Conclusion 10 References 11 국문초록 19Maste

Male Adolescents Lived Experiences of Father-Son Relationships

본 연구의 목적은 청소년기 아들이 아버지와의 관계에서 무엇을 체험하며, 그 체험 속에드러난 아버지와의 관계의 의미가 무엇인지 이해하는 것이다. 이를 위해, 서울 및 경기 지역에 살고 있는 남자 중?고등학생 6명과 개인별 3회의 심층면접을 실시하였고, van Manen(1990)의 해석학적 현상학의 관점으로 자료를 분석하였다. 연구결과로는 보이지 않는벽, 불거지는 갈등, 성장의 길목에서의 아버지, 마음 속 아버지의 자리, 아버지와 가족, 희망사항이라는 총 6개의 주제를 통해 남자 청소년과 아버지와의 관계 체험의 구조를 살펴보았으며, 이러한 체험의 구조 속에서 거리두기, 부재 속의 고투, 두 마음의 부딪침, 보이지않는 끈이라는 4개의 관계 체험의 의미를 발견하였다. 연구참여자들은 아버지로부터 신체적, 정서적으로 거리를 두면서 탈이상화된 기반 위에서 아버지와의 관계를 현실적으로 재조정하였다. 아버지는 그냥 돈을 벌어오는 사람, 말만 아빠라고 느껴질 뿐 아버지로부터 관심이나애정을 체감하기 어려웠으며, 아버지와의 피상적이고 공소(空疎)한 관계 속에서 청소년기의힘겨운 고투를 하고 있었다. 하지만 이러한 빈약한 정서적 유대관계 속에서도 아버지에 대한갈망을 드러냈으며, 아버지로부터 간섭받지 않고 독립적인 것을 원하면서도 동시에 의존하고친밀한 관계를 맺고 싶은 욕구가 존재했다. 연구참여자들은 아버지와의 동질성과 일체감을인식했으며, 무의식적으로 연결된 무언의 힘을 느꼈다. 아버지의 모습을 내재화하며 동일시하였고, 아버지는 아들의 삶 속에 연결되어 있었다. 본 연구는 청소년기 아들의 관점에서 아버지와의 관계를 깊이 있게 이해함으로써, 청소년기 부자(父子)관계의 의미를 발견하고 원만한 부자관계를 형성하기 위해 고려해야 할 점을 재조명했다는 데 의의가 있다. The purposes of this study are to explore Korean male adolescents lived experiences in their relationship with their fathers and the meanings underlying these lived experiences. A series of in-depth interviews were conducted with six male adolescents who lived in Seoul and Gyeonggi province. van Manens phenomenological approach guided the entire research process. Our hermeneutic phenomenological analysis resulted in six main themes: invisible walls, emerging conflicts, a bumpy road to growth with an indifferent father, the fathers place in the sons heart, the father and his family, and wish lists. In addition, the four overarching meanings throughout the structure of the lived experiences were distancing, lonely struggles in the distant relationship, conflicting ambivalent emotions, and invisible ties. Most participants reported that they had a distant relationship with their fathers and were physically and emotionally separated from their fathers. These participants re-adjusted their expectations of the relationship with their fathers on the basis of de-idealization in a realistic manner. Most of the father-son relationships were not meaningful but empty and shallow while the participants struggled with a bumpy road in their adolescence. The male adolescents viewed their fathers simply as someone who was in charge of economic responsibilities. The sons wanted to be independent from their fathers, but they simultaneously had a longing for their fathers and wanted to rely on them and be in an intimate relationship with their fathers. The participants recognized their own similarities with their fathers and that there were invisible ties between the son and the father. They identified with their fathers, and the father had an influence on the sons lives. This study is meaningful in that it helps us understand the deeper aspects of father-son relationships by listening to adolescent sons voices and providing suggestions for harmonious father-son relationships.N