• Electric Engineers Magazine
• /
• v.195 no.11
• /
• pp.30-34
• /
• 1998

가공송전선의 접지는 주로 내뢰설계에 그 목적이 있지만 전력계통의 안정도, 전력계통의 고장검출과 철탑주변의 접촉전압 및 보폭전압에도 영향을 미치고 있는 것이 사실이다. 특히 전력계통에서 지락사고가 발생할 경우 지락전류가 송전철탑에 시설되어 있는 가공지선과 대지로 분류하는 정도에 따라 지락지점에서의 대지전위 상승이 크게 좌우된다.

• Proceedings of the Zoological Society Korea Conference
• /
• 1994.10a
• /
• pp.99.2-99
• /
• 1994

• Animal Systematics, Evolution and Diversity
• /
• v.12 no.1
• /
• pp.33-43
• /
• 1996

Two new species from Africa, Lotobia nigeriana and L. southafricana, are described and illustrated. These two new species are similar each other, but can be differentiated based on the coloration and male genitalic structure. Relationships among all 24 Lotobia species are analyzed using cladistic method. Revised synapomorphies for the genus Lotobia are provided and taxonomic status of the genera of the subfamily Sphaerocerinae is also discussed.

• Korean Journal of Plant Resources
• /
• v.31 no.1
• /
• pp.37-51
• /
• 2018

Molecular phylogenetic analysis was conducted to evaluate the taxonomic relationships of genus Arisaema L. distributed in Korea and the molecular phylogenetic characteristics of three authentic Arisaema species for the herbal medicine Arisaematis Rhizoma (the rhizomes of A. amurense, A. heterophyllum, and A. erubescens). The sequences of three DNA barcodes (rDNA-ITS, matK, and rbcL) were analyzed using 50 samples of nine taxa consisted of eight Korean and one Chinese Arisaema with one outgroup (Dracunculus vulgaris). Both individual and combined phylogenetic analyses of three DNA barcode sequences revealed that the treated nine taxa are independently classified into six distinct clades (Clade I, A. amurense f. amurense and A. amurense f. serratum; Clade II, A. serratum and A. takesimense; Clade III, A. ringens; Clade IV, A. erubescens; Clade V, A. heterophyllum; Clade VI, A. thunbergii subsp. thunbergii and A. thunbergii subsp. geomundoense). These six clades were reasonably divided into three individual sections, Pedatisecta, Sinarisaema, and Tortuosa. Futhermore, the results of comparative DNA barcode sequences analyses provided a significant information for the taxonomic reconsideration of Arisaema L. at the specific and intraspecific level. However, we could not confirm the taxonomic characteristics or identity among the three authentic medicinal species through the molecular phylogenetic analyses of genus Arisaema L. for Arisaematis Rhizoma.

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

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.05a
• /
• pp.633-634
• /
• 2002

• Herbal Formula Science
• /
• v.1 no.1
• /
• pp.28-60
• /
• 1990

• Korean Journal of Plant Resources
• /
• v.23 no.4
• /
• pp.293-302
• /
• 2010

Taxa of Artemisia collected in Korea were constructed by molecular phylogenetic analysis based on the internal transcribed spacer(ITS) regions of nrDNA. The length of the ITS sequences aligned using the clustal X program was 636~643 bp, and the lengths of the ITS1 and ITS2 regions were 251~255 bp and 217~222 bp, respectively. The total number of variable sites was 95 for the entire sequence, and a parsimony- informative site represented an efficacious site in ITS1 rather than in ITS2. The maximum parsimony tree as calculated by the MEGA 4 program was clustered into five clades. The taxa(A. capillaris, A. japonica var. japonica, A. japonica var. hallaisanensis, A. japonica subsp. littoricora) degenerated ovary of clade 1 was supported as the subgenus Dracunculus by Ling's classification system. The results show that A. nakaii and A. fukudo were quite similar genetically(Boostrap 99%) and that the scientific name of Korean A. dubia should be reconsidered. A. sp. distributed in Ganghwa province was grouped with A. argyi(Boostrap 89%). These results suggest that the molecular techniques used in this study could be useful for the phylogenetic analysis of Korean Artemisia herbs having variations in their morphological characteristics.

• Pediatric Infection and Vaccine
• /
• v.22 no.3
• /
• pp.194-200
• /
• 2015

Purpose: Urinary tract infection (UTI) is a common bacterial infection in children and Escherichia coli is a predominant pathogen. The purpose of this study is to evaluate phylogenetic groups and virulence factors of E. coli causing UTI in children in Korea. Methods: From October 2010 to April 2013, urinary E. coli strains were isolated from the 33 pediatric patients of UTI. Multiplex polymerase chain reactions were performed to evaluate the phylogenetic groups and 5 virulence factor genes (fimH, sfa, papA, hylA, and cnf1) of E. coli. Distribution of molecular characteristics of E. coli was analyzed by clinical diagnosis and accompanying vesicoureteral reflux (VUR). Results: Most (84.8%) uropathogenic E. coli were belonged to phylogenetics group B2 and the others (15.2%) were belonged to group D. The virulence factors were distributed as: fimH (100%), sfa (100%), hylA (63.6%), cnfI (63.6%), and papA (36.4%). According to clinical diagnosis, phylogenetic distribution of E. coli strain was 92.3% of B2 and 7.7% of D in acute pyelonephritis and 57.1% of B2 and 42.9% of D in cystitis. Distribution of virulence factors was similar in both groups. In patients with acute pyelonephritis, phylogenetic distribution was similar in VUR and non-VUR group, but proportion of papA genes were lower in VUR group than that of non-VUR group (43.8% vs. 20.0%, P=0.399). Conclusions: This study provides current epidemiologic molecular data of E. coli causing pediatric UTI in Korea and will be a fundamental for understanding the pathogenesis of pediatric UTI.

• Korean Journal of Plant Taxonomy
• /
• v.42 no.3
• /
• pp.185-196
• /
• 2012

Morphological and geographical examinations as well as phylogenetic analyses using ITS sequences were performed for Asparagus L. in Korea. A total of five species of Asparagus were confirmed to be distributed in South Korea. The shape of cladophylls, length of pedicels, and shape of perianth were considered to be important characteristics for the identification of Koran Asparagus species. A monophyly of each species was evident in the ITS phylogenetic trees in which multiple accessions (5 to 24, depending on species) represented each of the five Korean species. A. rigidulus Nakai, once considered conspecific to A. schoberioides Kunth, formed a distinct lineage in the ITS trees. Pedicels of A. rigidulus, which is distributed mainly in coastal areas, were about two times longer than those of A. schoberioides occurring in inland areas, suggesting that they should be treated as distinct taxa.