• ALGAE
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• v.18 no.4
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• pp.295-299
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• 2003

The population dynamics of Ecklonia stolonifera was investigated at Tongyeong coastal area in the South Sea of Korea. The blade length and width, stipe length and diameter, mean total length and mean weight were measured from randomly collected fifty individuals in every month. The plants in Tongyeong population were relatively bigger than those of Busan Korea and Aomori Japan in terms of their blade length and width. The population biomass was low in winter and high in spring and summer. The sporangial sori were found from August to December but prominent in September and October. About 90 % of the Tongyeong population was consisted of one- and two-year old plants and the zoosporangial sori were observed mostly in two-year old plants. It was different from the results of Busan and Aomori population in which the zoosporangial sori were observed from the plants older than three years. The new populations were developed from the zoospores of two-year old plants and their generation time was relatively shorter than those of Busan and Aomori.

• Genes and Genomics
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• v.40 no.12
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• pp.1319-1329
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• 2018

SSRs were successfully isolated from the Perilla crop in our current study, and used to analyze Perilla accessions from East Asia. Analyses of the clear genetic diversity and relationship for Perilla crop still remain insufficient. In this study, 40 new simple sequence repeat (SSR) primer sets were developed from RNA sequences using transcriptome analysis. These new SSR markers were applied to analyze the diversity, relationships, and population structure among 35 accessions of the two cultivated types of Perilla crop and their weedy types. A total of 220 alleles were identified at all loci, with an average of 5.5 alleles per locus and a range between 2 and 10 alleles per locus. The MAF (major allele frequency) per locus varied from 0.229 to 0.943, with an average of 0.466. The average polymorphic information content (PIC) value was 0.603, ranging from 0.102 to 0.837. The genetic diversity (GD) ranged from 0.108 to 0.854, with an average of 0.654. Based on population structure analysis, all accessions were divided into three groups: Group I, Group II and the admixed group. This study demonstrated the utility of new SSR analysis for the study of genetic diversity and population structure among 35 Perilla accessions. The GD of each locus for accessions of cultivated var. frutescens, weedy var. frutescens, cultivated var. crispa, and weedy var. crispa were 0.415, 0.606, 0.308, and 0.480, respectively. Both weedy accessions exhibited higher GD and PIC values than their cultivated types in East Asia. The new SSR primers of Perilla species reported in this study may provide potential genetic markers for population genetics to enhance our understanding of the genetic diversity, genetic relationship and population structure of the cultivated and weedy types of P. frutescens in East Asia. In addition, new Perilla SSR primers developed from RNA-seq can be used in the future for cultivar identification, conservation of Perilla germplasm resources, genome mapping and tagging of important genes/QTLs for Perilla breeding programs.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.428-434
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• 1997

The effect of genetic diversity in sub-populations on breeding efficiency was examined with prospect of potential crossbreeding. Simulation study of selection was performed for 20 generations with 20 replications each, comparing average breeding values and inbreeding coefficients between the two breeding systemes; single population scheme and two population scheme. The different genetic levels were assumed to be caused by different gene frequencies. Phenotypes of two traits generated polygenic effect with additive 36 loci and residuals distributed normally were selected by selection index procedure. High genetic gain with less inbreeding was clearly recognized in the single population scheme, independently of difference in genetic level, economic weight and genetic correlation. Genetic correlation after selection in the single population scheme was lower than the two population scheme. When crossbreeding between the sub-population was taken into account, superiority of the two population scheme was suggested under those restrictions; difference in genetic level is moderate, selection criterion for the two traits is not far from even economic weight, and genetic correlation is positive with low to moderate value. The use of complementarity increased the possibility of the two population scheme.

• Korean Journal of Social Welfare
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• v.64 no.4
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• pp.337-357
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• 2012

This study explores a changing social expenditure structure of welfare states on new social risks, using logistic regression analysis with Panel Corrected Standard Errors Model on panel data of 1997-2007 years from 27 OECD nations. The result of this study presents that social expenditure structures have been adjusted with new social risk structure due to trade openness, female employment rates, and child population rates. Greater trade openness, higher women's employment rates, and lower child population rates are, more social investment expenditures are than income security expenditures. Rates of employment in service industries and elderly population rates are not statistically significant on the change of social expenditure structure. This result does not imply a complete switch from demand-based to supply-based social policy, but somewhat reflects transitions of a social welfare system for changing economic and social environments in order to sustain welfare state economically.

• Korea journal of population studies
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• v.24 no.1
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• pp.41-65
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• 2001

This study aims a comparative analysis of social stratification in the Great Seoul area using two types of population. One type of population is a resident population(常住人口), and the other is a daytime population주간인구(晝間人口). In most demographic studies, only resident population have been considered. There has been less attention to daytime population. However, a resident population have a character of night population야간인구(夜間人口). In fact, most people move and work in the areas where they do not live in everyday life in the contemporary period, which indicates that the concept of a daytime population is more significant than that of a resident population. This study reveals that a number of people, on the one hand. come together to the downtown area to work or study while they live in other areas. On the other hand, resident population in downtown area do not move so much. When we analyze the social stratification structure of the Great Seoul area using a resident population, we find that the resident population of downtown area consist of those of low social status. On the contrary, the daytime population of downtown area in Seoul consist of those of high social status. This means that most people of high social status live in the southern area of Seoul or outside Seoul, but make a living in downtown area in everyday life. From this study, we find that the concept of a daytime population is as important as that of a resident population. The more residence becomes separate from work place, the more the significance of the concept of a daytime population grows in making policy as wall as in demographic studies. This study implies that we need to pay more attention to the concept of daytime population in demographic and sociological Studies.

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.837-851
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• 2016

The growth and development of Gwangyang city was a result of the POSCO Gwangyang Works, and Gwangyang city is one of typical firm citys in Korea. The objective of this study is to identify and examine the change of migration and population structure in Gwangyang city from 2001 to 2010. Since 1981, total number of population of Gwangyang city increased from 78,478 in 1981 to 145,512 in 2010. The population structure by age was changed with population increase since 2001, and 30-40 aging group was 35% of total in 2010. During 2001-2010, the netmigraion showed -2,925 people, however, the number of inmigrants were overtaking the number of out-migrants since 2008. The most common reason of in-migrants was occupation(49.5%). Factors influencing Gwangyang City's population growth and oversupply are the location of POSCO Gwangyang Works and steel-related enterprises, opening and construction of Gwangyang container berth, the related development projects and establishment of Gwangyang Bay Area Free Economic Zone, and the local policies of Gwangyang City connected with these large-scale national projects. As a result, the number of manufacturing-related businesses increased due to various regional development projects conducted in Gwangyang City, and the growth of the business continued to increase due to the increase of younger people and births.

• Journal of Life Science
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• v.16 no.6
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• pp.898-903
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• 2006

The genetic diversity and population structure of fifteen Potentilla discolor Bunge populations in Korea were determined using genetic variations at 19 allozyme loci. Fourteen of the 19 loci (73.7%) showed detectable polymorphism. Genetic diversity at the species level and at the population level was high ($H_{ES}\;=\;0.215$, $H_{EP}\;=\;0.196$, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}\;=\;0.069)$. Total genetic diversity values $(H_T)$ varied between 0.0 and 0.656, giving an average overall polymorphic loci of 0.292. The interlocus variation of genetic diversity within populations $(H_S)$ was high (0.274). On a per locus basis, the proportion of total genetic variation due to differences among populations $(G_{ST})$ ranged from 0.010 for Pgm-2 to 0.261 for Pgd-2 with a mean of 0.069, indicating that about 6.9% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. discolor. The estimate of gene flow based on $G_{ST}$ was high among Korean populations of P. discolor (Nm = 3.36).

• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.115-120
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• 2010

Genetic variation and population structure of the slender bitterling Acheilognathus lanceolatus of Korea (the Han, Geum, Dongjin, Seomjin and Nakdong Rivers) and Japan (the Katsura River) were assessed by amplified fragment length polymorphism (AFLP) analysis. Five combinations of selective primers generated 345~374 DNA fragments, of which 55~131 were polymorphic. The Nakdong River population had the highest genetic diversity and the Han River population had the lowest genetic diversity. Dendrogram based on the distance matrix revealed that individuals from each population consistently clustered together and bifurcated into two distinct clades (or population groups) composed of the Han, Geum, Dongjin and Seomjin River populations and of the Nakdong and Katsura River populations, supported with high bootstrap values. The pairwise genetic differentiation ($F_{ST}$) estimates showed that the six populations were genetically well differentiated (P<0.01). The analysis of molecular variance (AMOVA) after partitioning the six populations into two population groups revealed very strong biogeographic structuring between them with 25.49% of total variance (P<0.01). Taken together, the AFLP markers clearly divided six A. lanceolatus populations into two population groups.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.1
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• pp.1-7
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• 2018

Information on the patterns of genetic diversity and population structure is essential for the rational use and efficient management of germplasms; accurate information aids in monitoring germplasms, and can also be used to predict potential genetic gains. In this study, we assessed genetic diversity, focusing on Korean rice accessions for theand their sustainable conserved diversity. Using DNA profiling with 12 simple sequence repeat (SSR) markers, we detected a total of 333 alleles among 2,016 accessions. The number of alleles ranged from 21 to 53, with an average of 27.8. Average polymorphism information content was 0.797, with the lowest being 0.667 and the highest 0.940. CA cluster analysis and the model-based population structure revealed two main groups that could be subdivided into five subgroups. Analysis of the molecular variance study based on the SSR profile data showed 5% variance among the profiles, whereas we recorded 93% variance among individuals and 2% variance within individuals. Specifically, the utilized diversity for of the breeding program is restricted in that cultivars were located in limited clades. These results revealed that preserving the diversity of Korean landraces could be useful sources for breeding new rice cultivars, and cwould be the basis for the sustainable conservation and utilization of a Korean rice germplasm.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1381-1386
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• 2014

In spite of variation in coat color, size, and production traits among indigenous Bangladeshi cattle populations, genetic differences among most of the populations have not been investigated or exploited. In this study, we used a high-density bovine single nucleotide polymorphism (SNP) 80K Bead Chip derived from Bos indicus breeds to assess genetic diversity and population structure of 2 Bangladeshi zebu cattle populations (red Chittagong, n = 28 and non-descript deshi, n = 28) and a semi-domesticated population (gayal, n = 17). Overall, 95% and 58% of the total SNPs (69,804) showed polymorphisms in the zebu and gayal populations, respectively. Similarly, the average minor allele frequency value was as high 0.29 in zebu and as low as 0.09 in gayal. The mean expected heterozygosity varied from $0.42{\pm}0.14$ in zebu to $0.148{\pm}0.14$ in gayal with significant heterozygosity deficiency of 0.06 ($F_{IS}$) in the latter. Coancestry estimations revealed that the two zebu populations are weakly differentiated, with over 99% of the total genetic variation retained within populations and less than 1% accounted for between populations. Conversely, strong genetic differentiation ($F_{ST}=0.33$) was observed between zebu and gayal populations. Results of population structure and principal component analyses suggest that gayal is distinct from Bos indicus and that the two zebu populations were weakly structured. This study provides basic information about the genetic diversity and structure of Bangladeshi cattle and the semi-domesticated gayal population that can be used for future appraisal of breed utilization and management strategies.