• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.517-523
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• 2003

The physical properties of polypropylene (PP) membranes under the radiation field were investigated. To calculate radiation flux affecting to PP, it was used MCNP4A Code. The PP membrane and deoxygenation equipment were standardized to bar structure in order to calculate the phonton flux with MCNP4A Code. The change in the properties of the PP membrane to be used in deoxygenation equipment was rarely occurred during the usage work because the radiation level of reactor coolant water was very low level and The doses of radiation workers are very low. From the results, it was found that the Physical properties of PP membranes which used for nuclear power plant reactor coolant water disposal were not rarely changed under the simulated radiation field.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.467-472
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• 2024

Multiple sequence alignment (MSA) is a method of collecting and aligning multiple protein sequences or nucleic acid sequences that perform the same function in various organisms at once. clustalW, a representative multiple sequence alignment algorithm using BioPython, compares the degree of alignment by column position. In addition, a web logo and phylogenetic tree are created to visualize conserved sequences in order to improve understanding. An example was given to confirm the differences between humans and other species, and applications of BioPython are presented.

• Korean Journal of Plant Taxonomy
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• v.36 no.3
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• pp.189-207
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• 2006

Goodyera rosulacea, which is morphologically similar to G. repens, is described recently as a new species based on its distinct morphological characters such as rosette-formed leaves, short rhizome and habitat. To verify the taxonomic identity of G. rosulacea and its taxonomic relationship within Korean Goodyera taxa, sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and the trnL region of cpDNA from 24 accessions including 1 outgroup accession were analyzed. Aligned sequences were analyzed using maximum parsimony and distance method, and the taxonomic identity and the taxonomic relationships among the related taxa were estimated by the existence of private marker gene and the phylogenetic tree of the aligned sequences. Molecular data indicate that G. rosulacea gas several private marker genes and shows monophyly in phylogenetic trees of both ITS and trnL sequences. the pairwise distance between G. rosulacea and the orher taxa of Korean Goodyera was 3.49-6.68% for ITS region and 5.05-9.53% for trnL region, indicating that G. rosulacea could be treated as an independent species. Therefore, our molecular data support the taxonomic of G. rosulacea as a distinct species of Korea. In phylogenetic trees, G. rosulacea formed same clade with G. repens, which has similar morphological characters with G. rosulacea, and showed the lowest pairwise distance with G. repens among Korean Goodyera taxa. These molecular data sugguested that G. rosulacea and G. repens are closely related taxa.

• Korean Journal of Plant Taxonomy
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• v.39 no.1
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• pp.35-41
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• 2009

Astilbe (Saxifragaceae) is a genus well known for its disjunctive distribution in Asia and eastern North America. In this study, we reconstructed a molecular phylogeny of the genus using the sequences of ITS regions of nuclear ribosomal DNA. A total of 17 species representing major lineage of Astilbe and closely related taxa were included in the phylogenetic analyses. We obtained a Bayesian phylogenetic tree in which Saxifragopsis was positioned as a sister group to Astilbe. The Japanese endemic species, A.platyphylla was the most basal lineage within the genus. This species is well known for its distinct morphological features such as unisexual flowers, apetaly, and calyx with 7-11 lobes. Two species, A. biternata, a New World representative of the genus, and A. rivularis widely distributed in S. Asia, branched off early in the evolution of Astilbe. The remaining species formed a strongly supported core clade, which diverged into two robust geographical lineages: the first ("Japonica" clade) of species distributed in Japan, Taiwan, and Philippines and the other ("Rubra" clade), of taxa in China and Korea. The ITS phylogeny indicates that the Bering land bridges were the major route for the origin and dispersal of A. biternata. The two Taiwanese taxa and A. philippinensis were found to derive from the Japanese member, as the genus advanced southwards. The ITS phylogeny suggests that apetaly originated independently at least two times within the genus. Our results do not support Engler's classification system of the genus based on the leaf type (simple vs. compound), but reaffirm Hara's taxonomic idea which primarily considered the features of calyx.

• Research in Plant Disease
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• v.21 no.3
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• pp.235-242
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• 2015

A 2014 nationwide survey in radish fields investigated the distribution of common viruses and possible emerging viruses. Radish leaves with virus-like symptoms were collected and 108 samples assayed by RT-PCR using specific primers for Radish mosaic virus (RaMV), Cucumber mosaic virus (CMV), and Turnip mosaic virus (TuMV); 47 samples were TuMV positive, and RaMV and CMV were detected in 3 and 2 samples, respectively. No samples showed double infection of TuMV/RaMV, or RaMV/CMV, but two double infections of TuMV/CMV were detected. TuMV isolates were sorted by symptom severity, and three isolates (R007-mild; R041 and R065-severe) selected for BLAST and phylogenetic analysis, which indicated that the coat protein (CP) of these isolates (R007, R041, and R065) have approx. 98-99% homology to a previously reported TuMV isolate. RaMV CP showed approx. 99% homology to a previously reported isolate, and the CMV CP is identical to a previously reported Korean isolate (GenBank : GU327368). Three isolates of TuMV showing different pathogenicity (degree of symptom severity) will be valuable to study determinants of pathogenicity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.157-168
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• 2000

Sea urchin S. intermedius occurring in the Korean east coast is a cold water species that belongs to the family Strongylocentrotidae of Echinoidea. Although it is known that there are nine species in the family, species identification criteria, phylogenetic relationships, time and process of evolution of the family members have not been uncovered clearly. In the present study, I tried to find some clues to such problems for S. intermedius by means of DNA sequences. For this, cytochrome c oxidase subunit I (COI), one of the mitochondrial genes that evolve fast and follow maternal inheritance was analyzed. DNA was extracted from the female gonad of S. intermedius, a segment of COI gene amplified by polymerase chain reaction (PCR), and finally a total of 1077 base pair sequence of COI obtained by cloning and sequencing the PCR product. The sequence was compared with homologous genes of other sea urchins and echinoderm species. Phylogenetic trees of the COI gene segment revealed that S. intenedius is a sister species of S. purpuratus which lives along the east coast of the Paciflc. With reference to the fossil records of sea urchins and genetic distances in the molecular phylogenies, it is estimated that the two species were separated about 0.89 million years ago when the earth temperature fluctuated significantly. The current disjunct distribution patterns of the two species and the climate change of the earth at the time of separation suggest that speciation might have occurred by vicariance. The COI gene sequence obtained here now can be used as a molecular character which discerns S. intermedius from the other sea urchin species of Strongylocentrotidae.

• Korean Journal of Plant Taxonomy
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• v.45 no.4
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• pp.306-317
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• 2015

This study was conducted to address the taxonomic status of the Korean endemic species Saxifraga octopetala, which is sometimes considered conspecific to Micranthes manchuriensis. Extensive molecular phylogenetic analysis using nrITS sequences as well as morphological examination of type specimens of the two species were undertaken to ascertain the phylogenetic position and species delimitation of S. octopetala. In the resulting nrITS trees, a total of 65 accessions representing S. octopetala grouped together and nested within the Micranthes clade, exhibiting a close relationship with M. nelsoniana and M. manchuriensis. Multiple accessions of M. manchuriensis collected from China and Russia also formed a clade, showing a sister group relationship with M. nelsoniana var. pacifica and M. fusca. The ambiguous species entity of S. octopetala is thought to have originated from Nakai's misinterpretation of Wilford's collection (type specimens of M. manchuriensis), which is a complex collection including an inflorescence of M. nelsoniana. In spite of apparent morphological similarity between S. octopetala and M. manchuriensis, they differ in the presence and absence of underground stolons. The distinct position of S. octopetala within the Micranthes clade on the nrITS tree suggests that it should retain species status in Micranthes. Thus a new combination (Micranthes octopetala) is proposed.

• Korean Journal of Plant Taxonomy
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• v.46 no.1
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• pp.1-12
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• 2016

DNA sequences of nrITS regions obtained from 49 accessions representing 12 species and one variety within the section Adonanthe of the genus Adonis were analyzed to test the previous intra-sectional classification system and to determine their phylogenetic relationships. The results showed that the seven accessions of A. amurensis Regel et Radde included in the present study did not form a monophyletic group, as some of the accessions showed a close relationship with the Japanese endemic species A. ramosa Franch., which implies that the current species delimitation and identification of A. amurensis is problematic. Adonis pseudoamurensis W. T. Wang, which is frequently misidentified as A. ramosa in Korea, formed a segregated group, which suggests that they should not be considered as conspecific taxa. Accessions from A. shikokuensis Nishikawa et Koji Ito, A. multiflora Nishikawa et Koji Ito, and A. pseudoamurensis formed a clade, but monophyly of each species was not evident. The nrITS data did not support the classification system proposed by Wang, who classified sect. Adonanthe into four series, as most of these were found to be either polyphyletic or paraphyletic.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.1-6
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• 2000

가압 경수로의 증기발생기는 원자로(reactor vessel)와 가압기(pressurizer)에서 가열ㆍ가압된 1차 계통의 고온, 고압수가 터빈을 돌리는 2차 계통수와 열교환을 일으켜 고온ㆍ고압의 증기를 발생시키는 것으로, 전열관의 파손이 발생될 경우 1차 계통에서 2차 계통으로 방사능 물질이 누출되어 심각한 문제가 야기된다. 따라서 증기발생기의 전열관 손상이나 파손 문제는 원자력 발전소의 수명과 밀접한 관계가 있다. (중략)

• Feed Journal
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• v.5 no.5 s.45
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• pp.104-111
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• 2007

지금까지 동물의 이름이 나올 때마다, 그 분류학상의 이름을 쓰기위해 다양한 검색을 시도했으나, 그러한 이름이 반드시 일치하지는 않았다. 다음호에 예정되어 있는 전시 동물에서는 우에노(상야) 동물원에서만 420종의 동물이 있으므로, 동물 분류에 관해서 좀 더 관심을 가져볼 필요가 있다. 또, 사료 원료가 되는 식물에 대해서도, 그 분류에 대해 기술 하고자 한다. 이러한 과정에서 우리가 알 수 있는 것은 현재, 동식물의 분류법은 확립된 것이 아니고, 계속 변화하고 있다는 것이다. 2005년 2월 12일 아사히(조일) 신문에, DNA로 조사한 백합과의 분류가 종래의 계통수와 크게 달라, 가까운 장래 교과서나 그림도감도 대폭적인 재검토가 강요받게 될 것 같다고 보도되었다. 그러한 이유로 지금까지, 그리고 앞으로도, 주로 학명만을 필요에 따라서 표기하기로 했으며, 그 이유를 기술 하고자 한다.