• 대한조선학회논문집
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• 제45권4호
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• pp.403-410
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• 2008

This paper describes the optimization of the rudder section by the genetic algorism based on VLM(Vortex Lattice Method) and panel method. The developed propeller-rudder analysis program has been validated by comparing with experimental data. The research extends to optimize the anti-erosion rudder section of the large container ship. The object function is the amount of pressure at leading edge of rudder which is closely related with erosion phenomena. The optimized rudder has been compared with conventional rudder with NACA 0021 section by analyzing with the developed program. The finally optimized section has low and mild pressure distribution in comparison with the NACA rudder. The experiments is expected to be carried out for the validation of the present optimization and more parametric study of section geometry is also expected to be conducted in the near future.

• International Journal of Industrial Entomology and Biomaterials
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• 제11권2호
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• pp.93-98
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• 2005

Studies on extended egg preservation schedule from 120 days to 180 days was taken up with 20 germplasm accessions of mutant silkworm genetic stocks of Bombyx mori L. Statistical analyses of the data collected over three trials revealed no significant changes both in the qualitative and quantitative traits of the genetic stocks between treatment (6 months egg preservation) and control (4 months egg preservation), except for fifth instar larval duration in TMS-61, TMS-62, TMS64, TMS-31 and TMS-34 shell weight in TMS-62, TMS-64 and TMS-66. Thus, the results indicate that extended schedule of 6 months egg preservation can safely be adopted, which will reduce the cost of conservation and minimize the genetic erosion owing to reduced crop cycle.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.68-68
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• 2017

The status of corn genetic diversity in the uplands of Sarangani in Southern Philippines was investigated using 12 morphological traits subjected to multivariate statistical analyses. Information about traditional farming, post-harvest and storage practices were also elicited especially in relation to losses of traditional varieties, a phenomenon known as genetic erosion. While a handful of farmers still plant traditional corn varieties in the remotest areas, a significant number had already shifted to genetically modified corn. Furthermore, principal component analysis (PCA) reduced the 12 morphological traits into 5 principal components and identified ear length and ear weight to be major contributors to variation. Cluster Analysis, on the other hand, formed two distinct groups but failed to give information about intra-cluster variability among the 32 collected corn accessions. These results warrant that more informative morphological traits and that molecular markers will be used to obtain a better picture of genetic diversity in Sarangani upland corn. Molecular analysis is also needed to establish genetic identities of these cultivars and to detect gene introgression from GM varieties into the gene pool of farmers' corn varieties. These analyses are imperative for the conservation of traditional corn varieties before they disappear in the Sarangani uplands because of shifting priorities of upland farmers.

• 한국산림과학회지
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• 제98권5호
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• pp.531-538
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• 2009

We used enzyme electrophoresis to evaluate genetic diversity in five populations of endemic ash, Fraxinus chiisanensis in Korea. Of 15 putative allozyme loci examined 26.7% were polymorphic and expected heterozygosity for the species was low (0.082). Within the range, population were highly differentiated ($F_{ST}$=0.356) and little genetic variation was explained by geography. The pattern of distribution of variation showed low genetic variation within populations and pronounced divergence among populations, which was consistent with the prediction for the effects of limited gene flow and local genetic erosion. Although the frequencies of male plants were dominant ranging from 79.3% to 89.4%, most mating events seems to be inevitable mating between relatives in small populations based on heterozygote deficiency of this species. Small effective population size and the limited dispersal contributed to the low rates of gene flow within as well as between populations.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1491-1500
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• 2019

Objective: European pigs have been imported to improve the economically important traits of Thai pigs by crossbreeding and was finally completely replaced. Currently Thai indigenous pigs are particularly kept in a small population. Therefore, indigenous pigs risk losing their genetic diversity and identity. Thus, this study was conducted to perform large-scale genetic diversity and phylogenetic analyses on the many pig breeds available in Thailand. Methods: Genetic diversity and phylogenetics analyses of 222 pigs belonging to Thai native pigs (TNP), Thai wild boars (TWB), European commercial pigs, commercial crossbred pigs, and Chinese indigenous pigs were investigated by genotyping using 26 microsatellite markers. Results: The results showed that Thai pig populations had a high genetic diversity with mean total and effective ($N_e$) number of alleles of 14.59 and 3.71, respectively, and expected heterozygosity ($H_e$) across loci (0.710). The polymorphic information content per locus ranged between 0.651 and 0.914 leading to an average value above all loci of 0.789, and private alleles were found in six populations. The higher $H_e$ compared to observed heterozygosity ($H_o$) in TNP, TWB, and the commercial pigs indicated some inbreeding within a population. The Nei's genetic distance, mean $F_{ST}$ estimates, neighbour-joining tree of populations and individual, as well as multidimensional analysis indicated close genetic relationship between Thai indigenous pigs and some Chinese pigs, and they are distinctly different from European pigs. Conclusion: Our study reveals a close genetic relationship between TNP and Chinese pigs. The genetic introgression from European breeds is found in some TNP populations, and signs of genetic erosion are shown. Private alleles found in this study should be taken into consideration for the breeding program. The genetic information from this study will be a benefit for both conservation and utilization of Thai pig genetic resources.

• Journal of Plant Biology
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• 제38권2호
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• pp.173-180
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• 1995

We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.

• 한국수정란이식학회지
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• 제32권3호
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• pp.235-241
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• 2017

가축유전자원으로서 흑염소 정액은 가축의 증식 및 유전적 개량을 위하여 동결정액으로서 보존될 필요성이 높으나 아직까지 연구 결과가 많이 누적되어 있지 않은 것으로 판단된다. 국내의 흑염소 동결유전자원의 생산성과 효율성 분석을 위하여 가축유전자원센터에서 보유 중인 흑염소 3 계통을 이용하여 전기자극방법에 의하여 채취된 정자와 정소상체유래 정자를 동결 보존하였다. 동결 전 Triladyl 난황희석액을 이용하여 흑염소의 정액과 혼합하여 $17^{\circ}C$에서 2시간 보존하면 응고현상을 관찰할 수 있었으며 42.9%의 비율로 난황이 변화한다는 것을 육안으로 관찰할 수 있었다. 정장 제거용 배양액으로 전기자극 유래 정자를 세정 후 동결 보존하면 융해 후 정자 생존율이 정액 세정용 배양액 $53.8{\pm}5.2%$로 나타났으며 정소상체 정자는 $74.6{\pm}10.6%$로 유의적으로 높게 관찰되었다. 융해된 정자의 장수성을 $17^{\circ}C$에서 조사해 보면 정소상체 유래 정자가 전기자극 유래 정자보다 우수한 것으로 조사되었다. 그러므로, 염소 동결 유전자원을 보존하는 방법으로 정소상체 정자는 활용성이 인정되며, 염소의 개량과 선발을 위하여 농가에서 활용 가능한 동결정액의 생산과 융해 후 생존성 증진을 위하여 더 많은 동결 보존 연구가 필요하다고 판단된다.

• 한국산림과학회지
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• 제107권4호
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• pp.378-384
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• 2018

대추나무는 갈매나무과에 속하며 과실에 높은 영양가를 지니고 있어 전통 한의학에서 널리 사용되고 있는 경제적으로 중요한 종이다. 국내에서 재배되고 있는 대추나무들의 품종실태를 파악함으로서 우량개체 선발과 육종계획 수립에 유용한 유전정보를 얻고자 보은, 경산 등 대추 주산지 6곳에서 수집된 대추나무 270개체를 대상으로 ISSR 표지 분석을 수행하였다. 그 결과 유전적 다양성을 보여주는 S.I.값은 0.107, 유전적 유사도는 0.935로 높게 나타나 연구에 사용된 대추나무들이 특정 품종 또는 개체에 편중되어 있었다. 또한 270개체 중 67%인 180개체가 '복조'와 동일한 유전자형을 나타내는 것으로 관찰되었다. 본 연구를 통해 국내 재배 대추나무 개체들의 유전적 다양성이 매우 낮은 것으로 파악되었다. 이에 외부 교란에 취약할 가능성이 큰 것으로 예상되며, 시장에 판매되고 있는 대부분의 대추가 단위결실을 통해 생산되는 것으로 판단된다.

• Journal of Genetic Medicine
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• 제16권2호
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• pp.62-66
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• 2019

Harlequin ichthyosis (HI, OMIM #242500) is one of the most severe skin diseases among the autosomal recessive congenital ichthyoses, with high morbidity and mortality, particularly in newborns. Clinically, it is characterized by a typical appearance of generalized, thick, yellowish, hyperkeratotic plates with deep erythematous fissures on the skin. Herein, we present the case of a newborn girl with HI that was genetically confirmed by targeted gene panel analysis. The premature baby was encased in an opaque white membrane with erosion covering the skin of the entire body except the lips, with her hands and feet restricted by the membrane. Humidification, emollient, and retinoic acid treatment were started; the thick ichthyosis gradually peeled off and the underlying skin was only covered with thin scales. Targeted gene panel analysis using next-generation sequencing and validation with Sanger sequencing and quantitative polymerase chain reaction analyses confirmed compound heterozygous mutations of the ABCA12 gene (p.N1380S and a partial gene deletion encompassing exon 9). The parents were carriers for each of the identified mutations. Early recognition of the genetic etiology of congenital ichthyosis can, thus, facilitate genetic counseling for patients and their families.

• 수산경영론집
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• 제47권3호
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• pp.53-69
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• 2016

The purpose of this study is to explore the ecosystem service and benefit indicators of natural seaweed beds. Ecosystems of natural seaweed beds provide a wide range of services and benefits to human society including provisioning services, regulating services, supporting services, and cultural services. Indicators for each of the ecosystem services are chosen by marine plants ecologists and as follows. Ecosystem indicators of natural seaweed beds for provisioning services are well-being food(amount of seaweed harvested/amount of fish landed, fish biomass, area of natural seaweed beds, the number of species, contribution to the second production), raw materials(amount of biomass by breed, amount of aquaculture feed), genetic resources(amount of genetic material extracted, amount of genetic material contained by age and habitat), and medicinal resources(amount of medicinal material extracted). Ecosystem indicators of natural seaweed beds for regulating services are air purification(amount of fine dust/NOx or $SO_2$ captured), climate regulation(amount of $CO_2$ sequestered), waste treatment(amount of N, P stored, biochemical degradation capacity COD), and costal erosion prevention(length and change of natural coast line, amount of sediment prevented). Ecosystem indicators of natural seaweed beds for supporting services are lifecycle and maintenance(primary production, contribution to the second production) and gene pool protection(amount of compositional factors in ecosystem, introduced species). Ecosystem indicators of natural seaweed beds for cultural services are recreation and tourism(the number of visits of an area) and information for cognitive development(amount of time spent in education, research and individual learning about ecosystem of natural seaweed beds).