• Fisheries and Aquatic Sciences
• /
• v.7 no.3
• /
• pp.130-135
• /
• 2004

The marine dinoflagellate genus Alexandrium, which produces PSP toxins, has a global distribution. As human-assisted dispersal of the species has been suggested, it is important to develop molecular tools to trace the dispersal pathway. To screen population-specific DNA sequences that differentiate Korean and Japanese A. catenella, we targeted the area downstream of the chloroplast psbA gene using PCR with population-specific DNA primers followed by RFLP (restriction fragment length polymorphism) analysis and sequencing. The RFLP patterns of the PCR products divided Korean and Japanese A. catenella regional isolates into three types: Korean, Japanese, and type CMC3, isolated from Korea. We sequenced the PCR products, but found no similar gene in a homology search. The molecular phylogeny inferred from the sequences separated the Korean and Japanese A. catenella strains, as did the RFLP patterns. However, the Japanese isolates included two slightly different sequences (types J and K), while the Korean sequence was the same as the Japanese K type. In addition, a unique sequence was found in the Korean strains CMC2 and CMC3. Population-specific PCR amplification with Japanese A. catenella type-specific PCR primers designed from the type J sequence yielded PCR products for Japanese strains only, showing that the unknown gene can be used for a population analysis of Korean and Japanese A. catenella.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.62 no.5
• /
• pp.1-13
• /
• 2020

The empty houses' problem is important in the local revitalization and local sustainability, and these phenomenon caused by various factors of the region. The population and housing census data are the most effective data available to study this phenomenon by small regions. In this study, logistic regression and multiple regression analysis were performed to understand the effects of population, household, and housing characteristics on empty houses using population and housing census data. Also, the scale and direction of the effect of each characteristic in large cities, small cities, and rural areas were compared. As results, there was a slight difference between cities and province regions in the district and housing characteristic variables. In the comparison of Eup-Myeon-Dong, the affected variables were different in the Dong and Myeon areas. The significance of this study is to examine the effect of the characteristics of population and housing on the vacant houses and to confirm that the factors affecting different regions.

• Journal of Environmental Impact Assessment
• /
• v.18 no.5
• /
• pp.293-299
• /
• 2009

Wintering migratory species of white-fronted geese (Anser albifrons) are common visitor in South Korea, and this study examined the survivorship of white-fronted geese in the Junam Reservoir with the application of Population Viability Analysis (PVA) technique. In Junam PVA analysis was done for the next 50 years using factors of breeding population, sex ratios, survivorship in the VORTEX program. As a result white-fronted geese will reach to carrying capacity within 40 years, and population will reach to carrying capacity later when it becomes smaller. Also with a large initial population white-fronted geese will reach to carrying capacity earlier. In conclusion, for the next 50 years the white-fronted geese are expected to a long-term survival with stable condition with survivorship (0.03) and extinction rate (0.0).

• Journal of Animal Science and Technology
• /
• v.62 no.6
• /
• pp.790-800
• /
• 2020

The Yeonsan Ogye (YO) chicken is a natural heritage of Korea, characterized by black feathers, skin, bones, eyes, and comb. The purebred of YO population has been reared under the natural mating system with no systematic selection and breeding plan. The purpose of this study was to identify the genetic diversity and find the optimal number of population sub-division using 12 polymorphic microsatellite (MS) markers to construct a pedigree-based breeding plan for the YO population. A total of 509 YO birds were used for this study. Genetic diversity and population structure analysis were conducted based on the MS marker genotype information. The overall average polymorphic information content value and expected heterozygosity of the population were 0.586, and 0.642, respectively. The K-mean cluster analysis based on the genetic distance result confirmed that the current YO population can be divided into three ancestry groups. Individuals in each group were evaluated based on their genetic distance to identify the potential candidates for a future breeding plan. This study concludes that a future breeding plan with known pedigree information of selected founder animals, which holds high genetic diversity, could be the best strategy to ensure the conservation of the Korean YO chicken population.

• Journal of Korean Society of Rural Planning
• /
• v.28 no.4
• /
• pp.1-9
• /
• 2022

Rural decline due to the decrease of the local population is an inevitable phenomenon, and a vicious cycle has been formed between a lack of basic living services and a population decrease in rural areas. Therefore, the study aims to derive the migration decision-making characteristics based on basic living service infrastructure data in rural areas. To do this, the population change over the past 20 years was categorized into six types, and the relationship between the classified population change types and the number of basic living service infrastructures was analyzed using decision tree analysis. Of the total 3,501 regions, 801 regions were the continuous decline type, of which 740 were rural areas. On the other hand, among 569 regions that were the continuous increase type, 401 regions were urban areas, confirming the population imbalance between rural and urban areas. As a result of the decision tree analysis on the relationship between population change types and the distribution of basic living service infrastructure, the number of daycare centers was derived as an important variable to classify the continuous increase type. Hospitals, parks, and public transportation were also found to be major basic living services affecting the classification of population change types.

• Journal of Korean Society of Rural Planning
• /
• v.29 no.4
• /
• pp.183-189
• /
• 2023

As South Korea faces a general decline in population, similar to other regions, its rural areas are also experiencing a downward trend. This study examines how the scale and shifts in population within rural towns(eup·myeon) are affecting the number of essential services such as hospitals, laundry shops, and beauty salons. Our analysis encompassed the populations of 1,403 towns, excluding nine areas due to lack of data as of 2020. Since the availability of basic services can vary with population size, we normalized the figures to reflect the number of services per 10,000 people, allowing for a comparative analysis across different population sizes. Generally, areas with more people showed an increase in the number of services per capita. Our review of changes from 2000 to 2020 revealed patterns in how service numbers adjust with population variations. Future research should delve into more detailed trends of these facilities and forecast the rural population's future to ensure that residents in areas where service sustainability may be challenging will have full access to necessary services.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.3
• /
• pp.302-306
• /
• 2001

This study was carried out to construct mapping population and to evaluate the methods involved, including polymorphic DNA marker system and appropriate statistical analysis. As an initial step to establish chicken genome mapping project, White Leghorn (WL) and Korean Ogol chicken (KOC) were used for generating backcross population. From 8 initial parents, total 280 backcross progenies were obtained and 40 were used for genotyping and linkage analysis. For development of novel polymorphic markers for KOC, Random Amplified Polymorphic DNA (RAPD) markers specific for this chicken line were generated. Also included in this study were six microsatellite markers from East Lansing map as reference loci. For segregation analysis, 15 RAPD markers and 6 microsatellites were used to genotype the backcross population. Among the RAPD markers that we developed, 2 pairs of markers were identified to be linked and another 4 RAPD markers showed linkage with microsatellites of known map. In summary, this study showed that our backcross population generated from the mating of KOC to WL serves as a valuable genetic resource for genotyping. Furthermore, RAPD markers are proved to be valuable in linkage mapping analysis.

• Development and Reproduction
• /
• v.23 no.2
• /
• pp.193-198
• /
• 2019

Genomic DNA samples were obtained from cultured penaeid shrimp (Penaeus chinensis) individuals such as fresh shrimp population (FSP) and deceased shrimp population (DSP) from Shinan regions in the Korean peninsula. In this study, 233 loci were identified in the FSP shrimp population and 162 in the DSP shrimp population: 33 specific loci (14.2%) in the FSP shrimp population and 42 (25.9%) in the DSP population. A total of 66 (an average of 9.4 per primer) were observed in DSP shrimp population, whereas 55 unique loci to each population (an average of 7.9 per primer) in the FSP shrimp population. The Hierarchical dendrogram extended by the seven oligonucleotides primers indicates three genetic clusters: cluster 1 (FRESH 01, 02, and DECEASED 12, 13, 15, 16, 17, 19, 20, 22) and cluster 2 (FRESH 03, 04, 05, 06, 07, 08, 09, 10, 11, and DECEASED 14, 18, 21). Among the twenty-two shrimp, the shortest genetic distance that exposed significant molecular differences was between individuals 20 and 16 from the DSP shrimp population (genetic distance=0.071), while the longest genetic distance among the twenty-two individuals that established significant molecular differences was between individuals FRESH no. 02 and FRESH no. 04 (genetic distance=0.477). In due course, PCR analysis has revealed the significant genetic distance among two penaeid shrimp populations.

• Korea journal of population studies
• /
• v.5 no.1
• /
• pp.79-98
• /
• 1982

• Journal of Korean Society of Rural Planning
• /
• v.20 no.4
• /
• pp.127-135
• /
• 2014

The purpose of this study is to show the relation of the change between spacial structure and social conditions of rural area. The spacial structure change of Asan city was analyzed using Space Syntax, and multiple regression analysis (dependent variables: connectivity, global integration, local integration / independent variables: population, household, farm population, farm population of 65years old and over, farm household, part-time farm households, cultivated land) was accomplished. As th result, that the increase of connectivity is related to the increase of population and farm population of 65years old and over and the decrease of farm population, and the increase of local integration is related to the increase of farm population of 65years old and over was showed. However, that global integration is not related to change of social conditions was proved.