• Parasites, Hosts and Diseases
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• 제53권2호
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• pp.177-187
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• 2015

Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles co-existed, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.

• 한국경제지리학회지
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• 제27권2호
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• pp.95-119
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• 2024

최근 서울대도시권 내 기업가정신의 공간분포에 관한 여러 연구가 있어 왔지만, 기업가 집적지들의 산업구성과 공간 분포 사이의 관계를 면밀히 살펴보지 못했다. 이에 본 연구는 2021년 벤처 캐피털 투자액 자료를 이용해 먼저 핫스팟 분석을 통해 기업가 집적지를 식별하였다. 이어서 집적지의 산업구성을 분석하기 위해 산업 다양성 및 전문화, 소프트웨어 및 비소프트웨어 산업 비중을 측정하였고, 집적지 조성 관련 정책도 검토하였다. 그 결과, 서울대도시권 내 14개의 기업가 집적지를 확인하였고, 도심에 인접한 집적지일수록 산업 다양성과 소프트웨어 산업 비중이 높으며, 정책이 교외 집적지의 산업 전문화에 크게 영향을 미치는 것을 확인하였다. 본 연구는 이러한 이해를 바탕으로 집적지 정책이 수립되어야 함을 시사한다.

• 한국경제지리학회지
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• 제17권1호
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• pp.129-146
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• 2014

본 연구는 산업구조의 다양성이 실업과 고용안정에 어떠한 영향을 미치는지를 지역경제 수준에서 분석하였다. 이를 통하여 대부분의 지역에서 일부 산업을 전략적으로 육성하려는 산업특화정책이 해당 지역경제의 안정성에 어떤 영향을 미쳤는지를 분석하였다. 실증분석을 위해 1993년부터 2010년까지의 우리나라의 16개 시도의 자료를 이용하여 허핀달지수를 측정하고 패널회귀모형을 이용하여 추정하였다. 주요 실증분석결과를 요약하면 다음과 같다. 첫째, 허핀달지수를 계산하여 산업구조 다양성 정도와 변화를 측정해 본 결과 대부분의 지역에서 1990년대에는 산업구조가 특화되다가 2000년대에는 다양화되는 방향으로 변화하는 패턴이 발견되었다. 둘째, 패널회귀모형의 추정 결과, 대부분 지역에서 산업구조의 다양성을 높일수록 실업률이 낮아지는 현상을 보였다. 그렇지만 산업구조 다양성과 고용불안정도 사이에는 통계적으로 유의한 관계가 부분적으로만 확인되었다. 셋째, 대도시일수록 실업률이 높고 고용이 불안정한 것으로 나타났지만 이러한 관계가 매우 유의하다고 보기는 어려웠다. 취업자수증가율이 높은 지역일수록 고용불안정지수는 낮고, 경제활동인구 중 여성비율이 높은 지역일수록 고용불안정지수는 낮으며, 취업자 중 대학 졸업자 비율이 높은 지역일수록 실업률이 높지만 고용불안정도는 낮은 것으로 나타났다. 이상과 같은 실증분석을 고려해보면, 지역전략 산업육성정책과 같은 산업특화정책은 정책의도와는 달리 지역경제 전반의 실업률을 상승시켜서 경제 불안정성을 증대시킬 가능성이 있다. 고용 측면의 관점에서 본다면 산업구조를 특화시키는 것보다 다양성을 높이는 전략이 바람직하다.

• Fisheries and Aquatic Sciences
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• 제14권1호
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• pp.16-21
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• 2011

The genetic diversity and population genetic structure of thread-sail filefish, Stephanolepis cirrhifer (Temminck & Schlegel), were examined with a nucleotide sequence analysis of a 495bp fragment of the 5'-end of the cytochrome b gene in 113 fish collected from five populations from the south and east coasts of the Korean Peninsula. Seventeen variable nucleotide sites and 16 haplotypes were defined. The observed haplotypes had a shallow haplotype genealogy and no geographical association. Most of the populations had high haplotype diversity and low nucleotide diversity, and significant negative values for Fu's $F_S$, suggesting rapid, recent population growth from an ancestral population and sudden population expansion. The estimated pairwise fixation indices ($F_{ST}$) indicate that substantial gene flow occurs among these populations. Thread-sail filefish in the South Sea of Korea and East Sea Korean populations forms a single panmictic population. Thus, thread-sail filefish in these areas should be treated as one management unit.

• The Plant Pathology Journal
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• 제30권1호
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• pp.10-24
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• 2014

Genetic diversity and differentiation of 50 Colletotrichum spp. isolates from legume crops studied through multigene loci, RAPD and ISSR analysis. DNA sequence comparisons by six genes (ITS, ACT, Tub2, CHS-1, GAPDH, and HIS3) verified species identity of C. truncatum, C. dematium and C. gloeosporiodes and identity C. capsici as a synonym of C. truncatum. Based on the matrix distance analysis of multigene sequences, the Colletotrichum species showed diverse degrees of intera and interspecific divergence (0.0 to 1.4%) and (15.5-19.9), respectively. A multilocus molecular phylogenetic analysis clustered Colletotrichum spp. isolates into 3 well-defined clades, representing three distinct species; C. truncatum, C. dematium and C. gloeosporioides. The ISSR and RAPD and cluster analysis exhibited a high degree of variability among different isolates and permitted the grouping of isolates of Colletotrichum spp. into three distinct clusters. Distinct populations of Colletotrichum spp. isolates were genetically in accordance with host specificity and inconsistent with geographical origins. The large population of C. truncatum showed greater amounts of genetic diversity than smaller populations of C. dematium and C. gloeosporioides species. Results of ISSR and RAPD markers were congruent, but the effective maker ratio and the number of private alleles were greater in ISSR markers.

• Animal cells and systems
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• 제15권3호
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• pp.243-249
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• 2011

The genetic diversity and population history of the Asian shore crab, Hemigrapsus sanguineus, were investigated with a nucleotide sequence analysis of 536 base pairs (bp) of the mitochondrial cytochrome c oxidase subunit I gene (COI) in 111 samples collected from four populations in Korea and one in Japan. In total, 28 haplotypes were defined by 27 variable nucleotide sites in the COI region examined. The observed haplotypes had a shallow haplotype genealogy and no geographical associations. Most of the populations had high haplotype diversity (0.656-0.788) and low nucleotide diversity (0.00165-0.00244), and significant negative values for Fu's $F_S$, suggesting rapid and recent population growth from an ancestral population and sudden population expansion. The pairwise fixation indices ($F_{ST}$) estimated with the exact test and the migration rates indicate that substantial gene flow occurs among these populations as a result of sea currents, except between the Yellow Sea coast of Korea (BUA) and the Pacific Ocean coast of Japan (JPA). These two populations (BUA and JPA) showed significant genetic differentiation and low migration rate.

• Journal of Plant Biology
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• 제38권4호
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• pp.329-336
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• 1995

Raphanus sativus L. var. hortensis f. raphanistroides (wild radish: Brassicaceae), a herbaceous perennial, occurs only on beaches in East Asia. Genetic diversity and population structure of seven Korean populations were investigated using starch gel electrophoresis. Although the Korean populatins are small, isolated with patchy distribution, the population maintain a moderate level of genetic diversity; the mean percentage fo polymorphic loci was 51.4%, mean number of alleles per locus was 1.84, and mean expected heterozygosity was 0.116. A combination of animal-outcrossing breeding system, wide geographical distribution, restricted ecological distribution, and a propensity for high fecundity may in part be explanatory factors contributing the moderate level of genetic diversity within populations. An overall excess of homozygotes relative to Hardy-Weinberg expetations (mean FISa=0.116) indicates that consanguineous mating occur within wild radish populations, leading to a family structure within a circumscribed area. Although population of wild radish experience a limited gene flow, only 5% of the total genetic variation found in Korean wild radish populations examined is due to differences among populations (mean GST=0.052). This value is considerably lower than the mean values of species with similar life history and ecological characteristics. However, significant differences were found in allele frequencies between populations for all polymorphic loci (P<0.01). It is supposed that directional selection toward genetic uniformity (similar gene frequencies) in a relatively homogenous habitat is thought to be operated among Korean wild radish populations.

• 한국약용작물학회지
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• 제13권2호
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• pp.69-74
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• 2005

Kalopanax pictus is a long-lived woody species mostly distributed in East Asia. K. pictus has been regarded as medically and ecologically important species in Korea. Thornless castor aralia variant, local name 'Cheongsong' is an endemic to Cheongsong province in Korea. Random amplified polymorphic DNA (RAPD) was used to investigate the genetic variation and structure of Korean populations of two species. A high level of genetic variation was found in six K. pictus populations. Twelve primers revealed 49 loci, of which 29 were polymorphic (59.2%). Nei's gene diversity for K.pictus and K. pictus variant were 0.119 and 0.098, respectively. Mean of genetic diversity in K. pictus was higher than average values for species with similar life history traits. The asexual and sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. An indirect estimate of the number of migrants per generation (Nm=0.857) indicated that gene flow was not extensive among Korean populations of K.pictus. It is suggested that the isolation of geographical distance and reproductive isolation between K.pictus and K.pictus variant populations may have played roles in shaping the population structure of this species.

• Journal of Forest and Environmental Science
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• 제38권1호
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• pp.12-20
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• 2022

Pongamia (Pongamia pinnata L.) as a source of non-edible oil, is potential tree species for biodiesel production. For several reasons, both technical and economical, the potential of P. pinnata is far from being realized. The exploitation of genetic diversity for crop improvement has been the major driving force for the exploration and ex situ/in situ conservation of plant genetic resources. However, P. pinnata improvement for high oil and seed production is not achieved because of unsystematic way of tree improvement. Performance of P. pinnata planted by Karnataka Forest Department was assessed based on yield potential by collecting 157 clones out of 264 clones established by Karnataka Forest Department research wing under different research circles/ranges. It was evident that the all the seed and pod traits were significantly different. Further, selection of superior germplasm based on oil and pod/seed parameters was achieved by application of Mahalanobis statistics and Tocher's technique. On the basis of D² values for all possible 253 pairs of populations the 157 genotypes were grouped into 28 clusters. The clustering pattern showed that geographical diversity is not necessarily related to genetic diversity. Cluster means indicated a wide range of variation for all the pod and seed traits. The best cluster having total oil content of more than 34.9% with 100 seed weight of above 125 g viz. Cluster I, II, III, IX, XV, XIX, XXI, XXIII, XXVI and XXVII were selected for clonal propagation.

• 한국환경과학회지
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• 제33권6호
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• pp.367-382
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• 2024

Alpine and subalpine plants are isolated and distributed in mountaintop areas at high altitudes and, are among the species most vulnerable to global warming. If the rate of warming continues at its current rate, it is highly likely that this species will be unable to find new refugia and will be the last to go extinct in their current habitats. Therefore, research on the distribution and diversity of alpine and subalpine plants is urgently needed and is important from the perspective of biodiversity conservation. Therefore, this study focused on the distribution of alpine and subalpine plants native to national parks. Alpine and subalpine plants distributed across the 12 national parks accounted for approximately half (47.78%) of all alpine plants in Korea. The average relative frequency of occurrence was 0.23, plant similarity between national parks was 37.19%, and beta diversity was 0.63. The number of species was positively correlated with the latitude, elevation, and area of the national park. Thus the geographical distributions of alpine and subalpine plants haves distinct spatial specificities and physical environmental differences.