• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.485-485
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• 2022

본 연구에서는 낙동강 수계에서 어류의 수생태 건강성이 악화된 지점, 장기간 수질이 악화되거나 수위가 저하된 지점, 보호종이 지정된 지점을 중심으로 어류 서식지적합도지수(Habitat Suitability index, HSI)를 산정하였다. 현장조사는 하천유량이 감소하는 4월부터 6월 사이 총 4회 실시하였고, 투망과 족대를 이용해 어류 채집하였다. 어류의 서식지 특성 조사를 위해 채집 지점에서 수심, 유속, 하상재료를 조사하고 기록하여 엑셀 자료를 구축하였다. 본 연구에서는 실제 하천 단면의 물리적 특성을 잘 반영할 수 있는 WDFW(Washington Dept. of Fish and Wildlife) 방법을 이용하여 어류 서식처적합도지수를 산정하였다. 낙동강 수계 10개 지점에서 실시한 어류 조사 결과는 전체 9과 35종 2,227개체이다. 낙동강 수계 10개 지점의 대표어종을 선정하기 위해 법정보호종, 유영성종, 고유종, 기타 중요종을 검토한 다음 각 지점별 대표어종, 대리어종, 유사어종 등을 산정하였다. 낙동강 수계 전반에 걸쳐 피라미가 우점종으로 조사되었으며, 낙동강 상류지역에는 모래무지, 하류에는 수수미꾸리와 유사한 종의 출현빈도가 높은 것으로 나타났다. 낙동강 전역에 걸쳐 서식하고 있는 피라미는 가능한 대표어종에서 제외하고, 보호종과 고유종을 중심으로 대표어종을 선정하였다. 그 결과 낙동강 상류 내성천 합류전 지점에서는 피라미, 내성천에서 참마자, 위천에서 참몰개, 갑천에서 돌고기, 황강에서 모래무지, 금호강에서 돌마자, 밀양강에서 쉬리. 남강에서 피라미, 형산강에서 참갈겨니, 태화강에서 피라미로 대표어종을 각각 결정하였다. 다음으로 각 지점별 대표어종에 대한 수심, 유속, 하상재료 조사 자료를 이용해 대표어종에 대한 서식지적합도지수를 산정하였다. 최근 갈수기 유량 감소로 생태계가 위협받는 기간이 증가하고 있다. 하천의 정상적인 생태기능 유지를 위한 최소한의 유량이 필요하고, 이를 확보하기 위한 노력이 요구된다. 어류의 서식지적합도지수를 활용해 갈수기 어류 서식에 필요한 최소한의 유량을 결정하거나, 수생태계 복원을 위한 기초자료로 활용성이 높을 것으로 판단된다.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.210-218
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• 1990

The survival and transfer of chromosomal genes coding for the synthesis of amino acids (threonine, tryptophan, histidine, leucine, methionine) and of plasmid-borne genes coding for resistance to antibiotics (chloramphenicol, kanamycin, erythromycin) by transformation in sterile and nonsterile soil (the soil was amended to 12% vol/vol with the clay mineral, montmorillonite) was studied. In pure culture, the numbers of vegetative cells of the Bacillus subtilis strains decreased by 1 to 1.5 orders of magnitude within one week, but spores of each strain showed lesser decreases. In sterile soil, the populations of vegetative cells and spores decreased by 1.5 to 3 orders of magnitude within 2 to 4 days and then showed little additional decreased. The transformation frequencies (number of transformants/numbers of donors and recipients) of individual amino acid-genes invitro ranged from $1.3{\pm}0.6{\times}10^{-6}$ to $6.0{\pm}2.36{\times}10^{-6}$, of two amino acid-genes from $8.5{\pm}0.7{\times}10^{-8}$ to $3.1{\pm}0.6{\times}10^{-7}$, and of the antibiotic-resistance genes from $1.5{\pm} 0.2{\itmes} 10^{-7}$ to $1.4{\pm} 0.4{\times} 10^{-5}$ . In sterile soil, the frequencies of transfer of individual amino acid-genes ranged from $2.0{\times} 10^{-7}$ to $2.0{\times} 10^{-5}$ and of the antibiotic-resistance genes from $2.0{\times} 10^{-7}$ to $9.4{\pm} 4.7{\times} 10^{-6}$. The transfer of two amino acid-genes in sterile soil was detected at a frequency of $2.0{\times} 10^{-6}$ to $4.5{\times} 10^{-6}$, but only in three instances. The transformation frequencies of antibiotic-resistance genes in nonsterile soil were essentially similar to those in sterile soil. However, to detect transformants in nonsterile soil, higher concentrations of antibiotics were needed, as the result of the large numbers of indigenous soil bacteria resistant to the concentration of antibiotics used in the sterile soil and in vitro studies. The results of these studies show that genes can be transferred by transformation in soil and that this mechanism of transfer must be considered in risk assessment of the release of genetically engineered microorganisms to the environment.

• Journal of Life Science
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• v.20 no.4
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• pp.589-596
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• 2010

We investigated antimicrobial activities of various pine (Pinus densiflora) needle extracts against antibiotic resistant strains of Staphylococcus aureus. Hot water extract showed the highest antimicrobial activity against normal and methicillin resistant Staphylococcus aureus (MRSA), however, it exhibited no antimicrobial activity against penicillin resistant S. aureus (PRSA). Hot water-hexane (HWH), hot water-ethanol (HWE), hexane, and ethanol extracts showed antimicrobial activity against S. aureus, PRSA and MRSA. Minimum inhibitory concentrations (MIC) of HWH, HWE, hexane, and ethanol extracts were 0.05, 0.05, 0.5 and 5 mg/ml, respectively, and HWH and HWE extracts showed the strongest antimicrobial activity among these extracts. Antimicrobial activities of pine needle extracts were stable after heating at $121^{\circ}C$ for 20 min. These results suggested that pine needle extracts can be used as an effective natural antimicrobial agent for food and medical industries.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.246-253
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• 1998

Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri which possessed the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The binding sites of heavy metal in the cells were investigated by chemical modification of functional groups the cell walls. To determine the binding sites of heavy metal in the cells, electrochemical charge of amine and carboxyl groups in the cell walls of heavy metal-tolerant microorganisms were chemically modified. Chemical modifications of amine groups did not affect the heavy metal uptake as compared to native cell walls. In contrast, modifications of carboxyl groups drastically decreased heavy metal uptake as compared to native cell walls, and electron microscopy confirmed that the form and structure of the heavy metal uptake were different from those of native cell walls. The results suggested that the carboxyl groups were the major sites of heavy metal uptake in the heavy metal-tolerant microorganism cell.

• Journal of Korea Water Resources Association
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• v.51 no.3
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• pp.183-193
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• 2018

Channel-forming discharge for downstream section of Yeongju dam in Naesung stream was calculated to analyze stable channel geometry. Determined channel-forming discharge was applied to design stable channel slope, depth, and base width at Yonghyeol station. Used data for channel-forming discharge and stable channel analysis were collected in downstream section of Yeongju dam in Naesung stream before the dam construction. Specified recurrence interval discharge, effective discharge, and bankfull discharge were analyzed and compared to decide final channel-forming discharge which was $260m^3/s$ of bankfull discharge. Stable channel analysis and design program was applied to predict stable channel section of width, depth, and slope with various sediment transport equations of Ackers and White, Brownlie, Engelund and Hansen, and Yang's equations. As a result, all equations of sediment transport produced milder slopes compared to current bed slope of 0.00177 and Ackers and White equation presented the most similar flow depth of current section with the design constraint of current channel width.

• Journal of Plant Biotechnology
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• v.42 no.1
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• pp.19-24
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• 2015

Glycine betaine (GB) is one of the compatible solutes that accumulate in the chloroplasts of certain halotolerant plants under salt or cold stress. The codA gene for choline oxidase, the enzyme that converts choline into GB, has been cloned from a soil bacterium Arthrobacter globiformis. We generated transgenic sweetpotato plants [Ipomoea batatas (L.) Lam] expressing codA gene in chloroplasts under the control of the SWPA2 promoter (referred to as SC plants) and evaluated SC plants under oxidative and drought stresses. SC plants showed enhanced tolerance to methyl viologen (MV)-mediated oxidative stress and drought stress due to induced expression of codA. At $5{\mu}M$ of MV treatment, all SC plants showed enhanced tolerance to MV-mediated oxidative stress through maintaining low ion leakage and increased GB levels compared to wild type plants. When plants were subjected to drought conditions, SC plants showed enhanced tolerance to drought stress through maintaining high relative water contents and increased codA expression compared to wild type plants. These results suggest that the SC plants generated in this study will be useful for enhanced biomass production on global marginal lands.

• The Korean Journal of Ecology
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• v.22 no.1
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• pp.39-43
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• 1999

Serratia marcescens, an enterobacterium of gram-negative bacteria, is characterized by resistance of the admium. Cadmium sensitive PM strain did not grow in the medium at cadmium concentration of 50 ppm. PA strain was induced to accommodate to cadmium by cultivating the mother strain (PC strain) in the medium with 50 ppm cadmium. As compared with PC and PM strains, PA strain revealed the excellent growth in cadmium media and accumulated four to five times higher cadmium concentration in cell than other strains. PA strain accumulated 23% of cadmium in cells when cultured in medium treated with 100 ppm cadmium and this cadmium was more accumulated in cytosol fractions than membrane fractions. Analysis by TEM indicated that cadmium was concentrated as a form of granule in cytosol. In protein patterns of cell after the treatment of cadmium, two inducible proteins (28 KDa and 64 KDa) and one reducible protein (45 KDa) were detected by SDS-PAGE. By Atomic Absorption Spectrophotometer, the amounts of cadmium attached to inducible proteins of 28 KDa and 64 KDa were 318.28 ㎍ and 325.37 ㎍ per gram of protein, respectively. It is assumed that these inducible proteins play an important role in the mechanism of cadmium accumulation in cells. A plasmid of 23Kbp was found in S. marcescens. The ability of resistance to cadmium in plasmid was confirmed by curing experiments.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.41-41
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• 2022

제주 내 크게 6개 지역에 흩어져 분포하고 있는 곶자왈은 화산활동으로 형성되었으며 제주 산림생물자원의 46%가 분포하여 생물종다양성이 매우 높은 것으로 알려져 있다. 곶자왈은 자갈과 바위로 이루어져 있으며 토양이 적게 발달하여 건조에 직면할 가능성이 크다. 본 연구는 곶자왈에서 서식하는 멸종위기종이자 산림청에서 희귀식물로 지정한 개가시나무(Quercus gilva)와 같은 속이면서 공존하고 있는 종가시나무(Quercus glauca)의 건조 내성에 대한 반응을 알아보고자 실내에서 생리 반응을 연구하였다. 온도(22±2.94℃)와 토양 양분(10%)은 자생지의 값을 기준으로 처리하였으며 수분 처리는 토양을 채운 화분에 물이 화분 밑으로 새어나가기 직전까지 포장용수량 700mL를 공급한 후 27일간 단수하였다. 단수기간에 수분함량의 변화는 토양수분함량측정기(Watch Dog)를 설치하여 데이터를 수집하였다. 항목은 토양수분함량에 따른 광합성률, 증산률, 수분이용효율, 기공전도도, Fv/Fm, Fo, Fm, 엽록소함량을 측정하였다. 토양수분함량은 25, 27일째를 제외한 기간에 개가시나무가 종가시나무보다 높았다. 광합성률은 27일째를 제외한 기간에 개가시나무가 종가시나무보다 높았다. 증산률은 4, 5, 11, 14, 25, 27일째에 개가시나무가 종가시나무보다 낮았다. 수분이용효율은 13일째를 제외한 기간에 개가시나무가 종가시나무보다 높았다. 기공전도도는 3, 9일째에 개가시나무가 종가시나무보다 높았다. Fv/Fm은 22, 27일째를 제외한 기간에 개가시나무가 종가시나무보다 높았다. Fo은 3, 14일째를 제외한 기간에 개가시나무가 종가시나무보다 높았다. Fm과 엽록소함량은 기간에 개가시나무가 종가시나무보다 높았다. 이와 같은 실험 결과로 보았을 때 개가시나무가 종가시나무보다 건조 내성에 강한 것으로 판단된다.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.307-315
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• 2016

This study was built to figure out the changes in Cortisol, Free fatty acids and muscle damage indicators, by conducting eight-week interval Taekwondo programs to obese women in their middle age. The exercise programs was consisted of 40 minutes interval Taekwondo workout each time, using the movement of the 80-85% of HRmax intensity. Overall, we got the following conclusions as a result of the conduct. First, Cortisol decreased before and after the 8 week interval, but it did not show a significant change. Second, the FFA showed a significant change by decreasing before and after the 8 week interval. Third, the muscular damage indicators showed a small decrease before and after the Taekwondo workout, but didn't show a significant change. Ultimately, the interval Taekwondo program didn't have a significant effect on improving stress tolerance, stress resistance and protecting muscle injuries, but can be effectively used to increase the lipid oxidation ability.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.353-361
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• 2005

In this study, we performed whole effluent toxicity(WET) test and compared the biological component analyses tests for some streams into which wastewater treatment plant effluents are discharged. The test procedures for the WET test and the biological component analysis were conducted according to U.S. EPA guidelines and the Ohio EPA wading method. The WET tests based on the test species of D. manga and S. capricornutum All treatment plants showed a S. capricornutum toxicity, and at 7 sites, except A and J, we could observe a D. magna toxicity. The highest toxicity was observed at site D and this were followed by E and F. The biological component analyses applied to the effluent discharged stream. We found that total species were low at sites C1, D1 and J1 and the low number of total individuals were observed at sites A1, C1, E1, H1, and J1 compared to the controls and other sites. The species richness was low at sites A1, B1, C1, D1, and J1. The species change was evident at site D(D1) and the tolerant species was predominant. The biological analyses and WET tests suggested that the effluents resulted in massive ecosystem impact.