• Animal cells and systems
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• 제15권1호
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• pp.37-43
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• 2011

The Korean freshwater crayfish, Cambaroides similis, has recently suffered from range reduction and habitat degradation caused by environmental changes and water pollution. For the conservation and restoration of this species, it is necessary to understand the current population structures of Korean C. similis using estimation of their genetic variation. In this study, eight micro satellite loci were developed and characterized from 49 individuals collected from four locations: one population from Mt. Bukhan (BH) and three populations from Mt. Gwanak (GA) in Seoul, Korea. As a result, the number of alleles per locus ranged from 2 to 12. The observed heterozygosities and expected heterozygosities ranged from 0.000 to 0.833 and from 0.125 to 0.943, respectively, and the former values were significantly lower than the latter ones expected under the Hardy-Weinberg equilibrium. No significant linkage disequilibrium was revealed between any of the locus pairs after Bonferroni correction. From the pairwise Fst results over all samples, higher differentiation between GA-BH population pairs (mean 0.1789) was observed than between GA population pairs (mean 0.0454). This was also supported by Mantel's test showing that the genetic distances of these crayfish populations were significantly correlated with geographic distances. This result may show the regional differentiation caused by restricted gene flow between northern (BH) and southern (GA) populations within Seoul. These micro satellite markers have the potential for use in analyses of the genetic diversity and population structure of C. similis species, with implications for its conservation and management plans.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.140.2-141
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• 2003

Among over-wintering small brown planthoppers, population of the rice stripe virus (RSV)-viruliferous insects was surveyed throughout the country in late April of 2003 by using DAS-ELISA. Averaged population of the RSV-viruliferous insects in this year was 2.1％, which was lower than that of last year of 3.7％. However, the insect population in Seoul, Incheon and Kyeonggi areas were relatively high showing 6.7％, 6.2％ and 2.6％, respectively. Based on the survey results, it was expected that overall occurrence of RSV on rice could be decreased in this year, except certain areas. Ovarial transmission rate of RSV by the insects on diseased rice samples collected from 10 areas ranged from 22.2％ to 77.8％. Among 35 graminous weed species collected from rice fields in Ganghwa and Kimpo in 2002 and 2003, common reed and formosens were found to be infected by RSV. The result indicates that those weeds are potential alternative natural hosts of the RSV Further studies on ecological and pathological impacts of the alternative natural host of RSV are being processed.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1525-1535
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• 2020

Synthetic dyes are widely used in various industries and their wastage causes severe environmental problems while being hazardous to human health, leading to the need for eco-friendly degradation techniques. The split-gill fungus Schizophyllum commune, which is found worldwide, has the potential to degrade all components of the lignocellulosic biomass and is a candidate for the treatment of synthetic dyes. A systematic molecular analysis of 75 Korean and 6 foreign S. commune strains has revealed the high genetic diversity of this population and its important contribution to the total diversity of S. commune. We examined the dye decolorization ability of this population and revealed 5 excellent strains that strongly decolorized 3 dyes: Crystal Violet, Congo Red and Methylene Blue. Finally, comparison of dye decolorization ability and the phylogenetic identification of these strains generalized their genetic and physiological diversity. This study provides an initial resource for physiological and genetic research projects as well as the bioremediation of textile dyes.

• The Korean Journal of Ecology
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• 제18권4호
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• pp.513-513
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• 1995

분리된 자원을 공급한다. 소척추동물과 포식자의 관계에서 동질로화된 서식지는 소척추동물의 생태적 지위를 단일화시켰으며, 숨을 곳의 급격한 감소로 인해 소척추동물의 군집 밀도를 큰 규모로 변동시킨다. 동질화된 서식지는 또한 서식지 구조의 복잡성을 사라지게 함으로써 종의 다양성이 감소된다는 연구결과를 검토하였다. 실험적연구에서 동질화된 서식지는 소척추동물의 서식밀도와 안정성의 감소, 세력권의 증가로 인한 종간경쟁, 분산의 증가로 특징지워졌다. 따라서 서식지의 이질성 유지는 종의 다양성과 보존의 기능을 높여주는데 기여함을 알게 되었다.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.295-301
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• 2011

We investigated the genetic structure of Korean and Japanese ayu Plecoglossus altivelis populations by examining 669 individuals from 14 populations using three microsatellite loci. Genetic variation did not differ significantly among the populations examined in terms of allelic number and heterozygosity. Korean populations were genetically close to each other, implying that persistent gene flow has occurred in these populations. This suggests that eastern populations in Korea form a single large population and all of the Korean populations are distinct from the Japanese populations. Pairwise population $F_{ST}$ estimates, principal component analyses, and a neighbor-joining tree showed that genetic separation between the southern and pooled eastern coast populations was probably influenced by restricted gene flow. Hierarchical analysis of molecular variance (AMOVA) revealed a weak but significant genetic structure among three ayu groups (eastern and southern coasts of Korea and the Japan coast), and no genetic variation within groups. The estimated genetic population structure and potential applications of microsatellite markers may aid in the proper management of ayu populations.

• 한국도로학회논문집
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• 제11권4호
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• pp.1-7
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• 2009

고령화가 진행될수록 고령운전자의 수 역시 증가될 것으로 예상되어 향후 고령운전자에 의한 교통사고는 급증할 것으로 판단된다. 본 연구는 고속도로 교통사고 발생시 고령층과 비고령층의 구분에 따른 교통사고 특성을 분석하였다. 분석결과 비고령층에 비해 고령층에 작용하는 영향요인이 다르게 나타남을 알 수 있었다. 로짓모형을 통해 비고령층과 고령층의 Odds Ratio를 분석하여 사고영향요인에 따른 차이점을 알아보았으며 고령운전자의 사고 분석 모형을 개발하였다. 비고령층에 비해 곡선구간 및 절토구간, 노면의 습기상태일 때 고령운전자의 사고위험이 높은 것으로 나타났다.

• Journal of Information Science Theory and Practice
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• 제8권1호
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• pp.68-78
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• 2020

This study attempted to uncover the characteristics of health information non-seekers among the United States foreign-born population and identify potential predictors of their non-seeking behavior. The trends of foreign-born health information nonseekers over the past twelve years were also examined. Statistical analysis was conducted with two sets of Health Information National Trends Survey (HINTS) data: HINTS 2 (2005) and HINTS 5 Cycle 1 (2017) datasets. It was found that foreign-born nonseekers differ from foreign-born seekers in terms of a variety of variables including education, income, English proficiency, the uses of Internet and social media, ownership of digital devices, ownership of health insurance, perceived health status, and level of trust in health information sources. Among them, education, Internet use, and trust in online health information were identified as predictors of the foreign-born population's non-seeking of health information. In addition, three variables - race/ethnicity, age, and place of accessing the Internet - which were significant factors in the 2005 dataset, were no longer significant in the 2017 dataset, implying the possible influence of smartphones that reduces Internet accessibility gaps among different racial/ethnic and age groups.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.77-85
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• 2022

Today's universities have a keen interest in educational reform. The issue of population decline in college-age due to population decline is not new. Universities have been developing quantitatively for a long time and are now considering ways to survive rather than qualitative growth. Since the sharp decline in the school-age population due to the population decline has no clear solution immediately, universities are overcoming this crisis by creating many alternatives. Attracting international students is one of them. In this study, the effectiveness of photovoice was examined through the analysis of the case of the Korean-Japanese convergence cartoon class. The photo-voice method has sufficient potential as a teaching method for foreign convergence classes and can be expected to play a role as a teaching method suitable for students participating in convergence classes with different social, cultural, and linguistic backgrounds. In particular, in the convergence class, since participating students generate research materials through photo production, it can be a tool for inner exploration necessary for webtoon production and a tool for narrative inquiry for storytelling. It is expected that expanding the understanding and use of photo voice will have the methodological value of convergence classes. In addition, the teaching method using photo voice produced in the composition of photos and stories is likely to be used as an appropriate tool for convergence classes for students with different social, cultural, and linguistic backgrounds.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.9-15
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• 2011

The functional cardiovascular system is comprised of distinct mesoderm-derived lineages including endothelial cells, vascular smooth muscle cells and other mesenchymal cells. Recent studies in the human embryonic stem cell differentiation model have provided evidence indicating that these cell lineages are developed from the common progenitors such as hemangioblasts and cardiovascular progenitor cells. Also, the studies have suggested that these progenitors have a common primordial progenitor, which expresses KDR (human Flk-1, also known as VEGFR2, CD309). We demonstrate here that sustained activation of BMP4 (bone morphogenetic protein 4) in hESC line, CHA15 hESC results in $KDR^+$ mesoderm specific differentiation. To determine whether the $KDR^+$ population derived from hESCs enhances potential to differentiate along multipotential mesodermal lineages than undifferentiated hESCs, we analyzed the development of the mesodermal cell types in human embryonic stem cell differentiation cultures. In embryoid body (EB) differentiation culture conditions, we identified an increased expression of $KDR^+$ population from BMP4-stimulated hESC-derived EBs. After induction with additional growth factors, the $KDR^+$ population sorted from hESCs-derived EBs displays mesenchymal, endothelial and vascular smooth muscle potential in matrix-coated monolayer culture systems. The populations plated in monolayer cultures expressed increased levels of related markers and exhibit a stable/homologous phenotype in culture terms. In conclusion, we demonstrate that the $KDR^+$ population is stably isolated from CHA15 hESC-derived EBs using BMP4 and growth factors, and sorted $KDR^+$ population can be utilized to generate multipotential mesodermal progenitors in vitro, which can be further differentiated into cardiovascular specific cells.

• Genomics & Informatics
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• 제12권3호
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• pp.127-133
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• 2014

Gastritis is a major disease that has the potential to grow as gastric cancer. Gastric cancer is a very common cancer, and it is related to a very high mortality rate in Korea. This disease is known to have various reasons, including infection with Helicobacter pylori, dietary habits, tobacco, and alcohol. The incidence rate of gastritis has reported to differ between age, population, and gender. However, unlike other factors, there has been no analysis based on gender. So, we examined the high risk factors of gastritis in each gender in the Korean population by focusing on sex. We performed an analysis of 120 clinical characteristics and genome-wide association studies (GWAS) using 349,184 single-nucleotide polymorphisms from the results of Anseong and Ansan cohort study in the Korea Association Resource (KARE) project. As the result, we could not prove a strong relation with these factors and gastritis or gastric ulcer in the GWAS. However, we confirmed several already-known risk factors and also found some differences of clinical characteristics in each gender using logistic regression. As a result of the logistic regression, a relation with hyperlipidemia, coronary artery disease, myocardial infarction, hyperlipidemia therapy, hypotensive or antihypotensive drug, diastolic blood pressure, and gastritis was seen in males; the results of this study suggest that vascular disease has a potential association with gastritis in males.