• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.2
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• pp.33-42
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• 1999

The objective of this study was to determine the optimal amount and the mixture ratio of seeds for revegetation species by investigating their growth characteristics. For the purpose of the experiments, 15 plants were chosen. In May of 1995 to September of 1998, the nursery seedbeds of the College of Agriculture and Life Sciences, Seoul National University were seeded with the mixtures of those species. Then, the nursery seedbeds were treated to investigate the effects of the amount of seeding, the amount of fertilizer, and the depth of soil on the growth characteristics. As the results of the experiments, it was found that the effects of all the treatments on growth of shoots and roots were significant in the early phase. For the expected number of seedlings more than 3,000 per square meter, many seedlings got withered to death while the survivors were suppressed to grow slow in the early stage due to the density problem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.279-284
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• 1995

The competition relationship between orchardgrass(Docflis glomerutu L. cv; Potomac) and red clover (Trifnlium prurense L. cv; Kenland) was investigated under the pure and mixed swards. Each species were grown in intra- and interspecific competition in pots and fields for 2-years. Intra- and interspecific competition were evaluated by calculating traditional methods; expected yield, relative yield total(RYT), aggressivity and compensation index(CI), and shoot and root dry matter production in the orchadgrass(ffi) pure, red clover(RC) pure and orchardgrdss(W)-red clover(RC) mixed sward. The results obtained were summarized as follows: Compared to OG and RC pure swards, the shoot and root dry maaer(DM) yield of OG-RC mixed sward were higher and more deeply rooted under the soil than those of OG and RC pure sward. Also, the number of tillen per plant of OG in the OG-RC mixed sward was less than that of OG pure sward, but that of RC in the OGRC mixed sward was more than that of RC pure sward. OG-RC mixed sward were evaluated as a productive sward type compared to OG and RC pure swards in that actual yield was higher than expect yield and that relative yield total(RYT), and compensation index(C1) were high. As mentioned above, compared to intraspecific competition as a OG and RC pure sward, interspecific competition as a OG-RC mixed sward was evaluated to productive type under the ffi and RC species utilization

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.30-38
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• 2017

The red-spotted apollo butterfly, Parnassius bremeri Bremer, 1864 (Lepidoptera: Papilionidae), is an endangered species in South Korea. Development and application of molecular markers to assess population genetics perspectives can be used as a basis to establish effective conservation strategies. In this study, we developed 12 microsatellite markers specific to P. bremeri using Illumina paired-end sequencing and applied the markers to South Korean populations to understand population characteristics. Genotyping of 40 P. bremeri individuals from three localities showed that at each locus, the observed number of alleles ranged from 6 to 22 and the observed and expected heterozygosities were 0.500-1.00 and 0.465 to 0.851, respectively. Significant deviation from the Hardy-Weinberg equilibrium was not observed in all loci studied. The population based $F_{ST}$ and $R_{ST}$ collectively suggest that at least the Samcheok population in northernmost Gangwon Province has a significant divergence from the remaining two populations (P < 0.01), and this result is also reflected in the forewing length. Further studies with an increased sample size will be necessary to draw robust conclusions and devise conservation strategies.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.8
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• pp.1087-1096
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• 2001

The dynamic structures of unsteady CH$_4$/Air jet diffusion flame with a flame-vortex interaction were numerically investigated. A timed-dependent, axisymmetric computational model and a low mach number approximation were employed in the present calculation. A two-step global reaction mechanism which considers 6 species, was used to calculate the reaction rates. The predicted results including the gravitational effect show that the large outer vortices and the small inner vortices can be well simulated without any additional disturbances near nozzle tip. It was found that the temperature and species concentrations have deviated values even for the same mixture fraction in the flame-vortex interaction region. It was also shown that the flame surface is not deformed by the inner vortex in upstream region, while in downstream region, the flame surface is compressed or stretched by the outer vortex roll-up. The present unsteady jet flame configuration accompanying a flame-vortex interaction is expected to give good implications for the unsteady structures of turbulent flames.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.805-810
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• 2007

Inter simple sequence repeat (ISSR) markers were performed in order to analyse the phylogenetic relationships of eight Hypericum electum populations in Korea. The six primers were produced 37 reproducible ISSR bands. Analysis of ISSR from individual plants of Korean H. erectum resulted in 22 polymorphic bands with 59.5%. Across populations, the mean number of alleles per locus was 1.348 and Shannon's information index was 0.203.Population Mt. Gyeryong had the highest expected genetic diversity (0.175) among all populations. When species were grouped by eight populations, within group diversity was 0.140 (Hs), while among group diversity was 0.472 (G$_{ST}$) on a per locus basis. The estimated gene flow (Nm) for H. erectum was very low (0.561). It is suggested that reproductive isolation by the isolation of geographical distance among H. electum populations and genetic drift may have played roles in shaping the population structure of this species. In phonetic tree, all populations were well separated from each other. Thus, ISSR markers are very effective in classifying natural population levels of genus Hypericum in Korea.

• Journal of Environmental Science International
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• v.5 no.1
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• pp.61-69
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• 1996

The combined wastewater of municipal landfill leachate and municipal sewage was treated using several sets of bench-scale aerated circulating system including porous media. Investigated items in this experiment were the dominant protozoa and metazoa in this system, the variation of microfauna relationship between operating condition and dominant genera. Also considered the factors determining dominant genera and their role. The outcome of this research is as follows; 1. Aspidisca, Vorticella, Truhellophyllum, Lecane, Philodina, Cyclops were mainly appeared prior to combinding leachate, while Trachelocerca, Bodo, Glaucoma were the dominant genera after combinding leachate. 2. As to metazoa, Nematode and Philodina were not influenced by 5oA leachate mixing ratio, meanwhile Crustacea has high sensitivity for increased leachate mixing ratio and it was not appeared in 5% leachate mixing ratio. 3. The appropriate treatability could'nt be expected at the above 10% leachate mixing ratio. Especially, in the condition of 20% leachate mixing ratio, all of the microfauna were affected damage seriously on their existence. Meanwhile hydraulic retention time, substrate loading rate and slut자e production rate didn't give notable influence on increasing the number of microfauna. 4. As to protozoa, saprozoic and holozoic species were appeared commonly and polysaprobic species were dominent. 5. Filamentous organsms were nearly not affected by leachate mixing. It seems that they could live without any trouble at the 10% leachate mixing ratio, if the substrate is sufficient. 6. Diversity of microfauna had a reducing trernd as the sewage was mixed with leachate.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.214-218
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• 2009

Platycodon grandiflorum is a long-lived herbaceous and one of the very important herbal medicine and foods. P. grandiflorum is called do-ra-ji in Korea. Inter-simple sequence repeats (ISSR) markers were performed in order to analyse the phenetic relationships of four accessions of P. grandiflorum. Wild groups had higher expected diversity, 0.164 for Korean and 0.157 for Chinese accessions than those of cultivated groups, 0.079 for Korea and 0.059 for China. The total genetic diversity in P. grandiflorum was 0.268 across species and the value was lower than average values for species with similar life history traits. The patchy distribution and domestication are proposed as possible factors contributing to low genetic diversity. An assessment of the proportion of diversity within species, HAccession/HSpecies, indicated that about 57.1% the total genetic diversity was among species. Thus, the majority of genetic variation (42.9%) resided within accessions. The estimated Nm (the number of migrants per generation) was very low among four accessions (mean Nm = 0.376). The low estimate of Nm indicated that gene flow was not extensive among four accessions. ISSR01-02 locus can be recognized as an unique locus of Korean groups (wild and cultivated accessions). Thus the locus can be used to distinguish Korean accessions from Chinese accessions. ISSR04-06 locus was found specific to Chinese groups (wild and cultivated accessions) and was not shown in Korean accessions. Although the size of sampling was not large enough for P. grandiflorum, the analyses of ISSRs will certainly provide an enhanced view on the phylogeny of accessions.

• Korean Journal of Environment and Ecology
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• v.11 no.2
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• pp.166-176
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• 1997

To investigate the vegetation structure of Fraxinus mandshurica communith, twenty plots were set up and surveyed in the valley of Mt. Minjuji area that rises 700~1,100m above the sea level. Each plot has 100m$^{2}$ in size. By using the TWINSPAN of classification technique, total plots was divided into six communities. In the species composition analysis, it was expected that F. mandshurica community would derive from Quercus mongolica community. The F. mondshurica community was composed together of Carpinus laxiflora, Acer mono and Cornus controversa. It was turned out that F. mandshurica community was edaphic climax because the competition species not appeared. In the DBH distribution analysis, F. mandshurica appeared through all layers, and species diversity showed lower index(Shannon's index 0.72~0.82) because the community was stable. The number of mean individuals and species was about 111.5 and 11.0 per 100m$^{2}$ respectively.

• Molecules and Cells
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• v.46 no.6
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• pp.329-336
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• 2023

Reactive oxygen species (ROS) serve as secondary messengers that regulate various developmental and signal transduction processes, with ROS primarily generated by NADPH OXIDASEs (referred to as RESPIRATORY BURST OXIDASE HOMOLOGs [RBOHs] in plants). However, the types and locations of ROS produced by RBOHs are different from those expected to mediate intracellular signaling. RBOHs produce O₂^•- rather than H₂O₂ which is relatively long-lived and able to diffuse through membranes, and this production occurs outside the cell instead of in the cytoplasm, where signaling cascades occur. A widely accepted model explaining this discrepancy proposes that RBOH-produced extracellular O₂^•- is converted to H₂O₂ by superoxide dismutase and then imported by aquaporins to reach its cytoplasmic targets. However, this model does not explain how the specificity of ROS targeting is ensured while minimizing unnecessary damage during the bulk translocation of extracellular ROS (eROS). An increasing number of studies have provided clues about eROS action mechanisms, revealing various mechanisms for eROS perception in the apoplast, crosstalk between eROS and reactive nitrogen species, and the contribution of intracellular organelles to cytoplasmic ROS bursts. In this review, we summarize these recent advances, highlight the mechanisms underlying eROS action, and provide an overview of the routes by which eROS-induced changes reach the intracellular space.

• Journal of Species Research
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• v.12 no.4
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• pp.281-285
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• 2023

The red-tongue viper(Gloydius ussuriensis) is one of only three species of the genus Gloydius found in South Korea. Gloydius ussuriensis has a narrow activity radius and is distributed nationwide, and this species was reported to have the largest population among the Korean species in genus Gloydius. Preliminary results of a phylogenetic analysis using part of the mitochondrial DNA indicated that domestic G. ussuriensis is not comprised of monophyletic groups, and morphological analysis showed differences between domestic populations. In this study, we developed 17 microsatellites for the analysis of G. ussuriensis genetic diversity based on these characteristics. These microsatellites were developed using six multiplex panels, which could be employed to validate 80 G. ussuriensis specimens from different geographical regions in South Korea. The average number of alleles per locus was 12.2 and ranged from 4 to 25 alleles; the observed heterozygosity ranged from 0.238 to 0.950 and the expected heterozygosity ranged from 0.213 to 0.933. As a result of assessing four inland populations, a high level of genetic diversity was confirmed. These newly developed markers will be useful for further studies on the population structure and evolutionary history of the G. ussuriensis.