• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.41-41
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• 2014

Pinewood nematode (PWN, Bursaphelenchus xylophilus) is a serious pathogenic worm that quickly dry pine trees to death. Recently, PWN has been devastating huge amounts of conifer trees in Korea. As a first step to explore the association and ecological roles of fungi in PWN life cycle in Korea, in this study we first isolated and indentified fungi from PWN-infested Korean pine and Japanese black pine wood sampled in Jinju, Sacheon, Pocheon, Chuncheon, Gwangju, and Hoengseong in Korea. A total of 144 fungal isolates were obtained from Japanese black pine wood and 264 fungal isolates from Korean pine wood. Their morphology and nucleotide sequences of the ITS rDNA and ♌-tubulin gene were examined for species identification. Ophiostoma ips, Botrytis anthophila, Penicillium sp., Hypocrea lixii, Trichoderma atroviride, O. galeiforme, Fusarium proliferatum were identified from Japanese black pine wood. Leptographium koreanum, L. pini-densiflorae, Ophiostoma ips, Penicillium raistrick, Trichoderma sp. were isolated from Korean pine wood. O. ips and L. koreanum were the major species on the two different PWN-infected pine tree. The cultivation of PWN on fungal mat of the identified species did some enhance PWN reproduction. The ambrosia beetle, Platypus koryoensis, is a serious pest of oak trees in Korea. In this study we investigated filamentous fungi present in the body of the beetle. Fourteen genera of filamentous fungi belonging to Ascomycota and Basidiomycota were isolated. All the obtained genera were isolated in the mitosporic state. The identified fungi were classified in 11 distinct orders including the Ascomycota (Eurotiales, Hypocreales, Microascales, Ophiostomatales, Pleosporales, and Sordiales) and Basidiomycota (Agaricales, Corticiales, Polyporales, and Russulales Xylariales). Within Ascomycota, 13 species were found. Meanwhile five species were found within Basidiomycota. The results showed the presence of diverse fungi in P. koryoensis. Among the isolated fungi, some were able to produce wood degrading enzymes. Further fungal isolation was performed with P. koryoensis infested Quercus mongolica trees sampled at Kumdan mountain in Hanam-Si, Gyeonggi province from June of 2009 to June of 2010. Penicillin spp. and Trichoderma spp. were the major species of mold fungi group. Pichia guilliermondii was the major species of mold yeast group. Raffaelea quercus-mongolicae was also isolated, but its isolation frequency was not high. Other species identified were Ambrosiella xylebori, Fusarium solani, Cryphonectria nitschke, Chaetomium globosum, and Gliocladium viride, Candida kashinagacola, C. maritima, C. vanderkliftii, Saccharomycopsis crataegensis.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.417-430
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• 1996

This study was conducted to investigate the developmental process of plant community during the secondary succession and the dynamics of soil properties in the burned and unburned areas of Mt. Ch’oly-san. Owing to the forest fire occurred on April, 1989, the red pine(Pinus densiflora) forest and its floor vegetation were burned down. The floristic composition of burned and unburned areas were composed of 53 and 49 species of vascular plants, respectively. The dominant species based on SDR4 of the burned sites were lespedeza cyrtobotrya (89.62), Miscanthus sinensis var. purpurascens (62.50), and Carex humilis (58.73), Quercus serrata (43.33). In contrast, Pinus densiflora (83.56), Lespedeza cyrtobotrya (55.57), Miscanthus sinensis var. purpurascens (51.88) and Carex humilis (50.41) were dominant in the unburned area. The biological spectra showed the $H-D_1-R_5-e$ type in both the burned and unburned areas. The indices of similarity ($CC_S$) between the two areas were 0.74. Degree of succession (DS) was 604 in the burned area and 802 in the unburned area. From these facts, it is assumed that the succession is rapidly progressing because of the recovery of vegetation. The species diversity ($\={H}$) and evenness index(C) in the burned and unburned areas were 0.15 and 0.18, respectively. Red pine tree did not resprout after scorch by the forest fire, but Lespedeza, Quercus, Rhododendron, Albizzia, and Zanthoxylum resprouted from the roots and trunks after the forest fire. It seems that these species are the fire-resistant species. Soil properties such as soil pH, content of organic matter, available phosphous, total nitrogen, tatal carbon, exchangeable potssium, sodium, calcium, and magnesium increased due to forest fire. These results suggest the intensity of forest fire in the study area was relatively weak. Monthly changes of soil properties were of little significance except for some cases.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.3-17
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• 2004

With the rapid growth of the Internet geographic information services through the WWW such as a location-based service and so on. Web GISs (Geographic Information Systems) have also come to be a cluster-based architecture like most other information systems. That is, in order to guarntee high quality of geographic information service without regard to the rapid growth of the number of users, web GISs need cluster-based architecture that will be cost-effective and have high availability and scalability. This paper proposes the design of the cluster-based web GIS with high availability and scalability. For this, each node within a cluster-based web GIS consists of main memory spatial databases which accomplish role of caching by using data declustering and the locality of spatial query. Not only simple region queries but also the proposed system processed spatial join queries effectively. Compare to the existing method. Parallel R-tree spatial join for a shared-Nothing architecture, the result of simulation experiments represents that the proposed spatial join method achieves improvement of performance respectively 23% and 30% as data quantity and nodes of cluster become large.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.253-258
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• 2006

Garlic is a perennial herb primarily distributed throughout the world. These plants are regarded as a medically and agricultural important crop in the world. The genetic relationships between cultivated and wild species were investigated at the population levels by constructing tree based on ISSR (inter-simple sequence repeats) markers. In addition, ISSR analysis was also conducted to estimate genetic diversity and population structure of these species. Three wild garlic populations in Korea were found to have more alleles per locus (mean 1.672 vs. 1.510) higher percent polymorphic locus (67.2 vs. 51.0), and higher diversity (0.250 vs. 0.198) than three cultivated populations. The cultivated and wild species in Korea are well separated from each other at phylogenetic trees. Although there is not direct evidence that A. victorialis is an ancestor of Korean A. sativum, there is a possibility that cultivated A. sativum in Korea has evolved from wild A. victorialis in Korea. Populations of A. victorialis may be useful in germ-plasm classification and evolutionary process.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.126-132
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• 2016

Objectives: This study aims to provide basic data regarding the bacterial total plate count in the atmospheric environment for related studies. Methods: Total plate count and the identification of culturable bacteria in the atmospheric environment in Incheon took place in 2015 using periodic survey. Correlationship analysis was performed between the number of culturable bacteria and environmental elements. In addition, an estimation of novel bacterial species was undertaken using the similarities and phylogenetic tree based on the 16S rRNA gene. Results: The total plate count of culturable bacteria was on average $176CFU/m^3$, and did not exceed $610CFU/m^3$ in the atmospheric environment. Periodic monthly measuring of total plate count was highest in June at $293CFU/m^3$, while the lowest was in July at $125CFU/m^3$. Furthermore, as a result of the identification of culturable bacteria, the genera Arthrobacter and Kocuria were dominant, while novel bacterial taxa that belong to the genera Chryseobacterium and Herbiconiux were separated. Conclusion: The total number of culturable bacteria from the atmospheric environment in Korea is on average $176CFU/m^3$. In addition, the genera Arthrobacter and Kocuria dominate. The presence of novel bacterial taxa are expected in the atmospheric environment, such as belonging to the genera Chryseobacterium and Herbiconiux.

• The Korean Journal of Nuclear Medicine
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• v.15 no.2
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• pp.11-17
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• 1981

Cholescintigraphic studies with $^{99m}Tc-HIDA$(dimethyl iminodiacetic acid) were performed in 22 cases of normal subjects, 21 of acute cholecystitis, 12 of chronic cholecystitis and 12 others, with the results of, 1) In normal control group, liver and intrahepatic biliary tree, CBD and gall bladder, and G-I tract appeared at 10, 20 and 30 minutes after intravenous injection of $^{99m}Tc-HIDA$ respectively, 2) In acute cholecystitis, 20 among 21 cases showed non-visualization of gall bladder with the diagnostic accuracy, sensitivity and specificity of 93.2%, 95.2% and 100% respectively. 3) In chronic cholecystitis, 5 among 12 cases showed non-visualization of gall bladder and remained 7 among 12 cases showed poor contraction of gall bladder (4), delayed visualization of gall bladder (1) and normal findings (2). 4) In the other disease group, the 12 cases which initially suspected as acute cholecystitis, revealed normal scan findings to exclude the cystic duct obstruction easily, With the above results, this scintigraphic procedure was found very rapid, accurate and easily available method for the determining of the cystic duct patency.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.58-65
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• 1999

The purpose of this study was to evaluate the effect of rehabilitation measures on the fired woodland of Chesuk-bong in Mt. Chiri through the vegetation structure and comparison of growth pattern between natural seedlings and transplanted Abies koreana seedlings. It was also discussed the rate of standing and fallen trees of dead conifers in the management strategy for vegetation regeneration and protection of sub-alpine area. In this fired woodland, shrub layers consisting of Weigela subsessilis, Sambucus williamsii var. coreana, Rhododendron schlippenbachii, R. mucronulatum, Tripterygium regelii, and etc. were gradually expanded, and tree species such as Betula ermani, Sorbus commixta, Acer pseudosieboldianum, and Malus baccata var. mandshurica were also regenerated. The growth of height and crown width of Abies koreana seedlings transplanted for vegetation regeneration were a little lower than those of natural seedlings. The seedlings of A. koreana transplanted in this fired woodland grew about 50.6% normally, but the others had multi-branched or growth stopped by death of terminal shoot. Because the number of dead conifers by fire tend to be gradually increased as time passed, it can occurs to the soil erosion and landslide by weakness of the cohesion and resistance of soil. Therefore, it is consider that rehabilitation measures projects of the fired woodland in subalpine area may be more prevention a natural disaster like soil erosion, flood and landslide.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.384-396
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• 2014

Vegetative compatibility groups (VCGs) are determined for many fungi to test for the ability of fungal isolates to undergo heterokaryon formation. In several fungal plant pathogens, isolates belonging to a VCG have been shown to share significantly higher genetic similarity than those of different VCGs. In this study we sought to examine the relationship between VCG and genetic similarity of an important cool season turfgrass pathogen, Sclerotinia homoeocarpa. Twenty-two S. homoeocarpa isolates from the Midwest and Eastern US, which were previously characterized in several studies, were all evaluated for VCG using an improved nit mutant assay. These isolates were also genotyped using 19 microsatellites developed from partial genome sequence of S. homoeocarpa. Additionally, partial sequences of mitochondrial genes cytochrome oxidase II and mitochondrial small subunit (mtSSU) rRNA, and the atp6-rns intergenic spacer, were generated for isolates from each nit mutant VCG to determine if mitochondrial haplotypes differed among VCGs. Of the 22 isolates screened, 15 were amenable to the nit mutant VCG assay and were grouped into six VCGs. The 19 microsatellites gave 57 alleles for this set. Unweighted pair group methods with arithmetic mean (UPGMA) tree of binary microsatellite data were used to produce a dendrogram of the isolate genotypes based on microsatellite alleles, which showed high genetic similarity of nit mutant VCGs. Analysis of molecular variance of microsatellite data demonstrates that the current nit mutant VCGs explain the microsatellite genotypic variation among isolates better than the previous nit mutant VCGs or the conventionally determined VCGs. Mitochondrial sequences were identical among all isolates, suggesting that this marker type may not be informative for US populations of S. homoeocarpa.

• The Plant Pathology Journal
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• v.33 no.2
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• pp.184-192
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• 2017

Tylenchulus semipenetrans is an important and widespread plant-parasitic nematode of citrus worldwide and can cause citrus slow decline disease leading to significant reduction in tree growth and yield. Rapid and accurate detection of T. semipenetrans in soil is important for the disease forecasting and management. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed to detect T. semipenetrans using DNA extracted from soil. A set of five primers was designed from the internal transcribed spacer region (ITS1) of rDNA, and was highly specific to T. semipenetrans. The LAMP reaction was performed at $63^{\circ}C$ for 60 min. The LAMP product was visualized directly in one reaction tube by adding SYBR Green I. The detection limit of the LAMP assay was $10^{-2}J2/0.5g$ of soil, which was 10 times more sensitive than conventional PCR ($10^{-1}J2/0.5g$ of soil). Examination of 24 field soil samples revealed that the LAMP assay was applicable to a range of soils infested naturally with T. semipenetrans, and the total assay time was less than 2.5 h. These results indicated that the developed LAMP assay is a simple, rapid, sensitive, specific and accurate technique for detection of T. semipenetrans in field soil, and contributes to the effective management of citrus slow decline disease.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.515-519
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• 2018

Triatoma rubrofasciata is a wide-spread vector of Chagas disease in Americas. In this study, we completed the mitochondrial genome sequencing of T. rubrofasciata. The total length of T. rubrofasciata mitochondrial genome was 17,150 bp with the base composition of 40.4% A, 11.6% G, 29.4% T and 18.6% C. It included 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. We constructed a phylogenetic tree on the 13 protein-coding genes of T. rubrofasciata and other 13 closely related species to show their phylogenic relationship. The determination of T. rubrofasciata mitogenome would play an important role in understanding the genetic diversity and evolution of triatomine bugs.