• 제목/요약/키워드: Population migration

검색결과 372건 처리시간 0.025초

멸종위기종 남방동사리의 보전을 위한 상세 분포 지역 및 개체군 크기 파악 (Identifying Distribution Areas and Population Sizes for the Conservation of the Endangered Species Odontobutis obscura)

  • 김정희;박상현;백승호;백충열
    • 생태와환경
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    • 제57권2호
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    • pp.102-110
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    • 2024
  • 본 연구는 현장조사와 문헌조사를 통해 멸종위기종 남방동사리의 정밀분포 현황을 제시하였으며, mark-recapture 방법을 활용하여 주요 서식구간에 대해 개체군 크기를 파악하였다. 거제도 내 18개 지방하천을 대상으로 현장조사를 실시한 결과 산양천 수계에 포함되는 산양천, 구천천, 부춘천 본류 및 유입지류에서만 남방동사리의 서식이 확인되었다. 남방동사리는 출현 지점별 0.5%에서 35.3%의 상대 풍부도를 보였으며, 일부지점에 대해서 상대풍부도가 높게(18.8~35.3%) 나타나 집중 서식 지역으로 확인되었다. 총 6건의 문헌 연구에서 남방동사리의 서식 여부를 확인하였으나 연구의 목적, 범위, 기간에 따라 출현 현황의 차이를 보였다. 현장조사와 문헌조사를 포함하여 분포 지역을 확인한 결과 남방동사리는 산양천, 구천천, 부춘천 본류 및 유입하천의 최상류부터 하류까지 고르게 서식하고 있었다. 현재 산양천 수계의 남방동사리는 수계 내 안정적인 서식을 유지하고 있으나 제한된 분포 범위는 장기적으로 유전적 다양성 결핍과 같은 문제를 내포하고 있다. 남방동사리 개체군 크기는 총 2개 지점에서 최종 확인되었다. 지점별 단위면적 (m2)당 0.5개체에서 1.5개체가 서식하는 것으로 확인되었으며, 방류지점으로부터 이동거리는 평균 13.1 m로 매복형 포식자의 제한된 이동 특성을 보였다. 멸종위기종 연구에서 종의 분포와 개체군 크기에 대한 현황을 파악하는 것은 멸종위기종 보전 및 보호를 위한 기초이며 중요한 단계이다. 이러한 정보를 바탕으로 서식지 위협 요인 분석, 기초 생태 (먹이, 서식, 산란) 연구, 환경유전자 활용 남방동사리 탐지기술 개발 등의 추가 연구가 이루어진다면 남방동사리의 보호에 큰 도움이 될 수 있을 것으로 판단된다.

Erythropoietin-producing Human Hepatocellular Carcinoma Receptor B1 Polymorphisms are Associated with HBV-infected Chronic Liver Disease and Hepatocellular Carcinoma in a Korean Population

  • Kim, Kyoung-Yeon;Lee, Seung-Ku;Kim, Min-Ho;Cheong, Jae-Youn;Cho, Sung-Won;Yang, Kap-Seok;Kwack, Kyu-Bum
    • Genomics & Informatics
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    • 제6권4호
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    • pp.192-201
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    • 2008
  • Erythropoietin-producing human hepatocellular carcinoma receptor B1 (EPHB1) is a member of the Eph family of receptor tyrosine kinases that mediate vascular system development. Eph receptor overexpression has been observed in various cancers and is related to the malignant transformation, metastasis, and differentiation of cancers, including hepatocellular carcinoma (HCC). Eph receptors regulate cell migration and attachment to the extracellular matrix by modulating integrin activity. EphrinB1, the ligand of EPHB1, has been shown to regulate HCC carcinogenesis. Here, we sought to determine whether EPHB1 polymorphisms are associated with hepatitis B virus (HBV)-infected liver diseases, including chronic liver disease (CLD) and HCC. We genotyped 26 EPHB1 single nucleotide polymorphisms (SNPs) in 399 Korean CLD, HCC, and LD (CLD+HCC) cases and seroconverted controls (HBV clearance, CLE) using the GoldenGate assay. Two SNPs (rs6793828 and rs11717042) and 1 haplotype that were composed of these SNPs were associated with an increased risk for CLD, HCC, and LD (CLD+HCC) compared with CLE. Haplotypes that could be associated with HBV-infected liver diseases by affecting downstream signaling were located in the Eph tyrosine kinase domain of EPHB1. Therefore, we suggest that EPHB1 SNPs, haplotypes, and diplotypes may be genetic markers for the progression of HBV-associated acute hepatitis to CLD and HCC.

중국동포(Chinese-Korean) 집단적 거주지에 나타난 지역사회에 대한 중국동포의 인식변화에 관한 연구 (A Study on Variation of Chinese-Korean's Recognition to the Local Community in their Enclave)

  • 김영로
    • 한국사회복지학
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    • 제63권3호
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    • pp.133-156
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    • 2011
  • 본 연구는 서울 영등포구 대림동 인근에 집단적으로 거주 및 활동하고 있는 중국 동포들을 심층 면담하는 질적연구방법을 사용하였다. 이를 통해 이들의 이주초기와 현재의 지역사회에 대한 인식변화 및 현실문제를 극복하려는 대응방법을 고찰하였다. 이들이 처해 있는 현실과 갈등, 현안의 극복 노력, 동포사회 내부변화와 지향방향 등을 이해하는 것은 우리사회로의 통합에 핵심변수가 된다. 이들은 이미 방대한 거주지를 형성했고 소수자집단화 되었으며 인정투쟁을 하는 동시에 권력의 열세를 극복하고자 정치권력을 쟁취하려고 시도하고 있다. 이들에 대한 사회복지적 개입은 외국인 유입으로 초래되는 사회파편화 방지를 위해 보다 적극적인 것이어야 하고 다민족 다문화 현상에 대한 우리의 적응과 이들을 주민으로 받아들이기 위한 상호계몽적인 질서를 구축, 전파하기 위한 방안이어야 한다.

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The first review study on association of DNA methylation with gastric cancer in Iranian population

  • Shahbazi, Mahsa;Yari, Kheirollah;Rezania, Niloufar
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권5호
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    • pp.2499-2506
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    • 2016
  • Background: Gastric cancer (GC) is the second leading cause of cancer-related death worldwide. Several environmental, genetic and epigenetic factors have been suggested to have a role in GC development. Epigenetic mechanisms like histone changes and promoter hyper-methylation are now being increasingly studied. Associations between methylation of many gene promoters with the risk of gastric cancer have been investigated worldwide. Such aberrant methylation may result in silencing of specific genes related to cell cycling, cell adhesion, apoptosis and DNA repair. Thus this molecular mechanism might have a key role in proliferation and migration of cancerous cells. Materials and Methods: In this review article we included studies conducted on DNA methylation and gastric cancer in Iranian populations. Using Science direct, Pubmed/PMC, Springer, Wiley online library and SciELO databases, all published data until 31 January 2016 were gathered. We also searched Science direct data base for similar investigations around the world to make a comparison between Iran and other countries. Results: By searching these databases, we found that the association between methylation of seven gene promoters and gastric cancer had been studied in Iran until 31 January 2016. These genes were p16, hLMH1, E-cadherin, CTLA4, $THR{\beta}$, mir9 and APC. Searching in science direct database also showed that 92 articles had been published around the world till January 2016. Our investigation revealed that despite the importance of GC and its high prevalence in Iran, the methylation status of only a few gene promoters has been studied so far. More studies with higher sample numbers are needed to reveal the relation of methylation status of gene promoters to gastric cancer in Iran. Conclusions: Further studies will be helpful in identifying associations of DNA methylation in candidate genes with gastric cancer risk in Iranian populations.

단편화된 서식처의 연결을 위한 야생동물 이동통로의 조성 -대상지 선정 및 조성기법을 중심으로- (A Study on the Wildlife Corridor for Connecting Fragmented Habitat -Focused on Site Selection and Design Methods-)

  • 김귀곤;최준영;손삼기
    • 한국조경학회지
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    • 제28권1호
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    • pp.70-82
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    • 2000
  • This is a study to generate a theoretical base for the development of wildlife corridor as a solution to the problems of wildlife population size reduction and declining bio-diversity resulting from the fragmented habitats caused by road constructions. This study seeks to examine and define techniques in very aspect of wildlife corridor including planning, site selection, design and development, and maintenance through an actual application. The results of this study are as follows. 1) The wildlife corridor should be developed in an approach supplementing a landscape ecological approach and a restoration ecological approach bilaterally. To this end, systematic methodology and process are required. 2) It was restored an ecosystem as close as possible go to the forest ecosystem before road development. In addition, in order to allow it to function as an ecological corridor, topography restoration, stream development, and ecological plantation were implemented. 3) The result of monitoring activities that continued for one year since the development confirmed the migration and inhabitation of a number of animals including small mammals. It is judged that it functions as a corridor in fragmented habitats as initially expected. 4) Through continuous monitoring in the future, the effects of corridor development on ecological restoration need to be reviewed in a long-term perspective. There is also a need to develop and refine a comprehensive maintenance plan for wildlife corridors and their surroundings. Based on such study results, actual data on the development of wildlife corridor should be accumulated. In follow-up studies, after continuous monitoring for a long period of time, the effects of wildlife corridor development should be evaluated comprehensively and wildlife corridor applicable to Korea should be standardized by correcting disclosed problems.

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PC 클러스터 기반 병렬 유전 알고리즘-타부 탐색을 이용한 배전계통 고장 복구 (PC Cluster Based Parallel Genetic Algorithm-Tabu Search for Service Restoration of Distribution Systems)

  • 문경준;이화석;박준호;김형수
    • 대한전기학회논문지:전력기술부문A
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    • 제54권8호
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    • pp.375-387
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    • 2005
  • This paper presents an application of parallel Genetic Algorithm-Tabu Search (GA-TS) algorithm to search an optimal solution of a service restoration in distribution systems. The main objective of service restoration of distribution systems is, when a fault or overload occurs, to restore as much load as possible by transferring the do-energized load in the out of service area via network reconfiguration to the appropriate adjacent feeders at minimum operational cost without violating operating constraints, which is a combinatorial optimization problem. This problem has many constraints with many local minima to solve the optimal switch position. This paper develops parallel GA-TS algorithm for service restoration of distribution systems. In parallel GA-TS, GA operators are executed for each processor. To prevent solutions of low fitness from appearing in the next generation, strings below the average fitness are saved in the tabu list. If best fitness of the GA is not changed for several generations, TS operators are executed for the upper $10\%$ of the population to enhance the local searching capabilities. With migration operation, best string of each node is transferred to the neighboring node after predetermined iterations are executed. For parallel computing, we developed a PC cluster system consists of 8 PCs. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through ethernet switch based fast ethernet. To show the validity of the proposed method, proposed algorithm has been tested with a practical distribution system in Korea. From the simulation results, we can find that the proposed algorithm is efficient for the distribution system service restoration in terms of the solution quality, speedup, efficiency and computation time.

농촌지역 주거약자를 위한 주택 리모델링 지원사업 개선방향 설정에 관한 연구 (A Study on the Improvement related with the House Remodeling Support Program for Underprivileged Group in Rural Area)

  • 김혜란;임창수;김상범;김은자;홍광우
    • 농촌계획
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    • 제19권2호
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    • pp.75-91
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    • 2013
  • In rural areas, in spite of the development projects of town and houses has been performed after the New Community Movement, due to rapid industrialization and urbanization, which lasted until the 2000s from the 1980s, out-migration to the cities, changes in the industrial structure, rapid aging was carried. As a result, the gap of housing environment between urban and rural areas became more serious. The meantime, the housing problem is recognized only to the problems of the big cities, mostly urban public housing policy oriented. However, when you check the indicator of the housing environment, such as the percentage of aging housing, rural environment has become a relatively poor compared to the city. In addition, due to a decrease in income and aging of the population living in rural areas of existing infrastructure to improve the living environment is weakened. And inside of the rural areas, changes in the housing environment and polarization phenomenon is becoming increasingly serious. Therefore, in this study, there is a purpose to be presented the improvement direction for efficient implementation of house remodeling support program for underprivileged group in rural areas and requires immediate attention improvement of housing environment. Previously, House remodeling support project in rural areas was carried out at the initiative of local governments and government mainly. For this reason, it is difficult due to limited institutional, to reflect the necessary parts directly to the real life of the residents. And, the demand for improvement of housing environment need modifications to solve the inconvenience of life of residents directly in many cases. It is considered that community-based house remodeling support project is to be carried out through the participation of local residents.

Mitochondrial DNA Sequence Variation of the Mason Bee, Osmia cornifrons (Hymenoptera: Apidae)

  • Kim, Hwa-Young;Lee, Kyeong-Yong;Lee, Sang-Beom;Kim, Se-Ryeon;Hong, Mee-Yeon;Kim, Dong-Young;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제16권2호
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    • pp.75-86
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    • 2008
  • In order to understand geographic genetic variation and relationship among populations of the mason bee (Osmia cornifrons Radoszkowsky), which is used as pollinator for apple tree, we sequenced a portion of mitochondrial (mt) COI gene, which corresponds to "DNA Barcode" region (658 bp) from 81 O. cornifrons individuals collected over eight localities in Korea. The sequence data revealed overall moderate to low genetic diversity within species, with a maximum sequence divergence of 0.76%. Geographically, two haplotypes (BAROC01 and BAROC02) were widespread with a frequency of 82.7%, whereas several haplotypes were found in a locality as a single individual, suggesting that haplotype distribution can be summarized as coexistence of a few widespread haplotypes and several regionally restricted haplotypes. Overall, high rate of per generation female migration (Nm=$1.1{\sim}$infinite) and low level of geographic subdivision ($F_{ST}=0{\sim}0.315$) among localities were characteristic. Although two populations (p < 0.026) were genetically subdivided from the remaining localities, no clear polarity was observed. Taken together, the nature of genetic divergence of the mason bee populations is characterized as one that possessing moderate to low genetic diversity, high gene flow, and wide spread haplotypes with ahigh frequency, concordant with the capability of dispersal in connection with the lack of historical biogeographic barriers.

Bis Is Involved in Glial Differentiation of PI9 Cells Induced by Retinoic Acid

  • Yoon, Jung-Sook;Lee, Mun-Yong;Lee, Jae-Seon;Park, Chan-Sun;Youn, Ho-Joong;Lee, Jeong-Hwa
    • The Korean Journal of Physiology and Pharmacology
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    • 제13권3호
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    • pp.251-256
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    • 2009
  • Previous observations suggest that Bis, a Bcl-2-binding protein, may playa role the neuronal and glial differentiation in vivo. To examine this further, we investigated Bis expression during the in vitro differentiation of P19 embryonic carcinoma cells induced by retinoic acid (RA). Western blotting and RT-PCR assays showed that Bis expression was temporarily decreased during the free floating stage and then began to increase on day 6 after the induction of differentiation. Double immunostaining indicated that Bis-expressing cells do not express several markers of differentiation, including NeuN, MAP-2 and Tuj-1. However, some of the Bis-expressing cells also were stained with GFAP-antibodies, indicating that Bis is involved glial differentiation. Using an shRNA strategy, we developed bis-knock down P19 cells and compared them with control P19 cells for the expression of NeuroD, Mash-1 and GFAP during RA-induced differentiation. Among these, only GFAP induction was significantly attenuated in Pl9-dnbis cells and the population showing GFAP immunoreactivity was also decreased. It is noteworthy that distribution of mature neurons and migrating neurons was disorganized, and the close association of migrating neuroblasts with astrocytes was not observed in P19-dnbis cells. These results suggest that Bis is involved in the migration-inducing activity of glial cells.

연변지역 탈북 아동 및 청소년의 체위와 식생활 양상 (Anthropometric Measurements and Dietary patterns of North Korean Migrant Children in China)

  • 장남수
    • Journal of Nutrition and Health
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    • 제33권3호
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    • pp.324-331
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    • 2000
  • A deteriorating North Korean economy, coupled with a devastating natural disaster such as flooding and drought in recent years, brought about a severe food shortage and malnutrition problem which caused a migration of its population including young children to neighboring countries. We conducted a nutritional survey on a total of 436 children, aged 4-19 years old, who migrated to the China side of the border from July to September, 1999. The study subjects were interviewed by Korean-Chinese interviewers who were trained for anthropometric measurements and dietary surveys. Heights, weights, and chest circumference of the subjects were 70-90% of the South Korean reference values for the corresponding age and sex. Dietary intakes of the subjects were found to be extremely poor-the average number of food, mostly of plant origin, consumed in a day was 2.8, and the proportion of the subject who reported to take all three meals in a day while residing in North Korea was as low as 36.2%. Ninety five percent of the subjects had at least one clinical symptom related to malnutrition, 68.6% had 2-4 symptoms, and 15.1% had 5 or more symptoms. The results of this study provided an objective data for the first time on the severity of the food crisis and malnutrition problem that afflicted North Korean older children and adolescents as well as children aged 7 or under as previously reported elsewhere. the wasted and stunted children and youths prevailing in North Korea could exert a negative influence on the country's health and economy. More researches are needed in the future to investigate on the impact of malnutrition in North Korean children on the country's social, economic, and cultural state as well as on the health and nutrition situation.

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