• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.320-330
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• 2006

An integrated health of a lotic ecosystem, Cho River, was evaluated by various approaches such as conventional water quality analysis, physical assessments of Qualitative Habitat Evaluation Index (QHEI), and the bioassay of Index of Biological Integrity (IBI) durin August${\sim}$September 2005. The IBI model used in the study was based on original multivariate metric model and then modified the metric attributes of the model for the regional application. Physical habitat health, based on the QHEI, was estimated using eleven metrics. During the study, values of IBI model averaged 36, which was judged as 'fair' to 'good' conditions. Spatial variations in the model values were evident: the headwater site (S1) was estimated as 48, indicating an 'excellent' condition, and the other sites were estimated 32${\sim}$38, 'good' condition. Values of the QHEI in the all sites averaged 148, which is judged as a good condition. The QHEI values varied from 120 (fair condition) to 199 (excellent condition) depending on the location of the stream. Site 5 (S5) was estimated as 'fair${\sim}$good' condition, while Site 7 (S7) was estimated as 'excellent' condition. The biological health, based on the IBI, reflected the habitat health. However, chemical conditions in terms of pH, turbidity, electric conductivity, dissolved oxygen (DO) did not make a difference in the biological health because of minor chemical differences among the locations.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.27-32
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• 2012

This study was carried out to investigate artificial insemination (AI) failure status and frozen semen characteristics in Korean proven bulls' number (KPN) semen used for AI of Hanwoo cows in Gangwon East region (Gangneung, Donghae, Taebaek, Samcheok, Sokcho, Yangyang, Goseong). Among semen used for AI, AI failure rate showed lowest at KPN506 (27.6%), whereas highest at KPN593 (77.2%). Correlations of AI failure in between Korean proven bulls semen and cows was 0.2941, which means that AI failure rate of Korean proven bulls semen may have respectable effect on reproduction of Hanwoo cow. In addition, present study was conducted to investigate spermatozoal viability rate, ruptured acrosome rate and active mitochondria in frozen Korean proven bulls semen with flow cytometry. The semen of KPN593 showed significantly ($p$<0.05) higher viability rate in KPN593 (30.49%) than that in KPN637 (37.34%). Furthermore, percentage of ruptured acrosome was lower in KPN637 as 21.37% than in KPN637 (21.37%), but it was not statistically significant. In conclusion, these results indicate that choice of Korean proven bulls semen may correlate positively with conception rate in Hanwoo cow. Therefore, KPN with high AI failure rate might be avoid to increase conception rate and characteristics of frozen semen might be evaluated before its use for AI.

• Korean Journal of Plant Taxonomy
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• v.37 no.2
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• pp.115-129
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• 2007

Using internal transcribed spacer (ITS) sequences and inter-simple sequence repeats (ISSRs) data, genetic diversity of a rare species, Hibiscus hamabo Siebold & Zucc. was examined for 3 populations in Jeju Island, Korea. A total of 14 nucleotide (excluding 3 ambiguous nucleotide) site variation in the ITS was observed from 18 individuals (Population 1, Hadori), which differed up to 13 bp in pair-wise comparison. On the contrary, the ITS sequences of all individuals in Populations 2 and 3 were identical. Genetic diversity estimates including Nei's gene diversity (h) generated by ISSR data were substantially high in Population 1 compared to other two populations. Low genetic variation in Populations 1 and 2 is considered due to genetic drift (bottleneck effect) and limited gene flow in these populations. Considering the differences in genetic diversity, protection of the Population 1(Hadori) is very critical for in situ conservation of Hibiscus hamabo in Korea. If ex situ conservation is required, making the full use of Population 1 will be most efficient.

• Journal of Life Science
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• v.13 no.1
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• pp.90-98
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• 2003

An allium rhizobacterium Serratia plymuthica AL-1 was previously selected as a biocontrol agent of allium white rot. The chitinase from S. plymuthica AL-1 produced in medium containing colloidal chitin was purified by ammonium sulfate precipitation (40~70%), affinity adsorption, column chromatography on DEAE-sephadex A-50 and sephadex C-200 gel filtration. The enzyme was purified 10.8-fold with a yield of 7.3% from the starting culture broth. The purified chtinase gave a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis, it's molecular weight was estimated to be 55 kDa. The optimum pH and temperature of the purified enzyme were pH 5.5 and $55^{\circ}C$, respectively and it is stable up to $50^{\circ}C$ and maintains around 90% of its activity for 60min. The enzyme were activated by $Ca^{2+}$, $Mn^{2+}$ and $Mg^{2+}$ and inhibited by $Cu^{2+}$, SDS, $\rho$-CMB, MIA, respectively. The purified chitinase showed broad spectrum of antifungal activities against plant pathogenic fungi Sclerotium cepivoruin, Alternana alternnta, Colletotrichum glceosporioidrs, Phoma sp., Sclerotinia sclerotiorum, Stemphylium solani, Fusarium oxysporium f. sp. niveum but rarely inhibited Phytophthora capsici and Pythium ultimum.. The purified chitinase from S. plymuthica AL-1 caused swelling, lysis, deceleration and degradation of the hyphal tips of S. sczerotiorum causing allium white rot. It suggest that S. prymuthica AL-1 chitinase play an important part in the bifunctional chitinase / lysozyme activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.594-599
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• 2006

In our previous report, we indicated that not only BSA but also BGG played an important role in the allergenicity of beef. In this study, the effect of heat or high-pressure treatments to beef extract on the SDS-PAGE patterns was examined. The antigenicity of each treated samples was also investigated by Western blots assay with the sera of BGG-positive beef allergic patients. The BGG band and its antigenicity slightly disappeared but not generally in $100^{\circ}C$ group, indicating $100^{\circ}C$ treatment is not sufficient to totally eliminate the antigenicity of beef allergens. Compared with BGG band, BSA band significantly disappeared in SDS-PAGE with $100^{\circ}C$ treatment, indicating BSA is more heat- sensitive than BGG. When the beef extract was heated at $120^{\circ}C$, not only BSA but also BGG bands was largely disappeared in both SDS-PAGE and Western blots. High pressure (HP) treatment even at 600 MPa did not affect SDS-PAGE and Western blots pattern of BSA. On the contrary, BGG treated with HP showed visible changes in SDS-PAGE. 600 MPa treatment significantly reduced the antigencity. Interestingly, these behaviors of BGG were not found in the same experiments with pure BGG treated with HP. From these results, it was speculated that some kinds of proteolytic enzymes in beef extracts were involved in the BGG molecular degradation by HP treatment. The aging experiments of beef extracts treated with HP supported this hypothesis. Further studies are needed to clarify the function and working mechanism of enzymes associated with BGG degradation in beef extracts by HP treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1552-1559
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• 2004

In order to evaluate the potential utilization value as a novel probiotic strain, the immunopotentiating activities of the cellular components from Lactobacillus brevis FSB-1 were examined. L. brevis FSB-1 isolated from kimchi were fractionated into the whole cell, cell wall, cytosol and extracellular preparation, and each fraction was examined on intestinal immune system modulating activity in vitro. The cell wall and cytosol preparation showed the relatively high bone marrow cell proliferating activity through Peyer's patch cell in a dose-dependent manner. But these preparations did not directly stimulate the bone marrow cell proliferation. The whole cell, cell wall and cytosol preparation also induced considerable levels of macrophage activation and mitogenicity of murine splenocytes in vitro. The anti-complementary activity (ITCH_(50)) of the cytosol fraction of L. brevis FSB-1 was the most potent in the cellular components, and the activity showed dose dependency. The complement activation by the cytosol fraction of L. brevis FSB-1 occurs via both alternative and classical pathways, which confirmed by the crossed immunoelectrophoresis using anti-human C3.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.483-494
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• 2019

This study aimed to determine the extent of artificial aquifer recharge and to evaluate appropriate recharge techniques based on field investigations and comparative analysis of each recharge method. Characteristics of the aquifer determine the target aquifer and the recharge method for artificial groundwater recharge. Electrical conductivity surveys, drilling, permeability tests, and grain-size analysis indicate that the hydraulic conductivity of weathered soil and weathered rock is higher than that of upper unconsolidated soil. Pumping tests indicate that the groundwater level was stable at a depth of 12 m until 9 hours of pumping, but after that it dropped again, indicating anisotropic aquifer characteristics. Three types of artificial recharge method were reviewed, including recharge wells, ditches, and ponds, and a combination of two methods is proposed: a recharge well system directly injecting into weathered soil and rock sections with good permeability, and an injection ditch that can increase the recharge effect by line-type injection in the upstream area. The extent of groundwater recharge by the selected methods will be evaluated through on-site tests and if their applicability is verified, they will contribute to securing water in areas of water shortage.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.242-251
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• 1989

Morphometric and genetic analyses on six populations of the two subspecies of Cobitis koreensis were performed to investigate the geographic variation and to clarify their taxonomic status. No significant differences between subspecies were found. Puan population of C. k. pumilus tends to be smaller in numbers of cross bars and dorsal spots, than those of C. k. koreensis populations with no statistical significance. Average degree of genic variation among six populations of the two subspecies was A=1.5, P =37.3%, HD=0.053, and HG=0.097. Marginal populations of Samchog (C. k. koreensis) and Puan(C. k. pumilus) were least variable: A= 1.3, P=23.8%, HD=0.0l0, HG=0.043, and A= 1.2, P=19.0%, HD=0.029, HG=0.078 respectively.The difference between HD and HG in all populations may indicate a patchness distribution between demes within each population. Genetic similarities between the two subspecies were, on the average, S=0.894, and this value correspond to the average genetic similarities among five populations of C. k. koreensis (5=0.899). Chongup population of C. k. koreensis and Puan population of C. k. pumilus was most similar genetically (5 =0.931). The results of morphometric and genetic analysis in this study indicate that C. k. pumilus is not a valid subspecies and should be considered as a population of C. koreensis.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.287-294
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• 1995

Studies were carried out to elucidate the efficacy of exogeneous 20-hydroxyecdysone treatment on terminating pupal diapause in the fall webworm. Hyphantria cunea Drury. And the difference was also investigated between normal adult development and post-diapause development after 20-hydroxyecdysone treatment. In the diapause termination rate of pupae treated with 20-hydroxyecdysone after storage for various periods at 16L:8D and $25\pm$$1^{\circ}C$, at the highest rate was observed from the group stored for the longest period and the lowest rate from those stored for 1.5 months. The time needed for adult emergence was inversely proportional to the chilling (at $0\pm$$1^{\circ}C$) period, and the longer its exposure period at low temperature, the higher its sensitivity to 20-hydroxyecdysone treatment. Pupal diapause duration was almost the same, regardless of storage period in the total darkness or at the photoperiod of 16L:8D, and also they successfully emerged to adult even without any experience at low temperature. The oxygen consumption rate in normally developing pupae showed nearly a typical U-form. But, that of diapausing pupae treated with 20-hydroxyecdysone slowly increased and jumped 14 days after the treatment. Pupal diapause began before formation of adult tissues, an a timing of adult tissue formation coincided with ascending timing of the metabolic rate in both normally developing pupae and diapausing pupae treated with 20-hydroxyecdysone. The diapausing pupae treated with 20-hydroxyecdysone was similar to normally developing pupae in band patterns of proteins from haemolymph or fat body.

• Korean journal of applied entomology
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• v.57 no.1
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• pp.33-38
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• 2018

Walnuts are one of the most economically important fruit trees in forestry. In walnut orchards, however, studies examining damage by insect pests are limited. This study was conducted to investigate the rate of damage caused by Conogethes punctiferalis to walnut fruits and by Acrocercops transecta to walnut leaves. In 2017, the change of damage rate (caused by C. punctiferalis) to fruits were investigated in Buyeo. In addition, we counted fruits and leaves damaged by two lepidopteran species in Gimcheon, Buyeo, Yeongdong, and Hwaseong. Damaged fruits steadily increased in abundance with fruit growth in Buyeo, and the highest number of damaged fruits was documented in late summer. The rates of damage caused by C. punctiferalis to fruits in Buyeo, Gimcheon, and Hwaseong were 22.1%, 20.5%, and 11.7%, respectively. Additionally, the rates of damage caused by A. transecta to leaves in seedlings (58.5% on average) were significantly higher than to those in older trees (11.2% on average), irrespective of the study location. In conclusion, this study showed that C. punctiferalis and A. transecta were serious pests affecting walnut fruits and leaves, respectively. Therefore, management methods for these insect pests need to be developed.