• Korean Journal of Ecology and Environment
• /
• v.33 no.3 s.91
• /
• pp.304-310
• /
• 2000

Enclosure experiments to reduce the growth of Cyanophyceae were carried out using plants in Kyongan stream. Wet plants put into the enclosure at a rate of 2.5 g wet wt/l and at that time, the average concentration of chlorophyll a was ranged from 30 to $50\;{\mu}g/l$. The dominant species was Microcystis aeruginosa. Ginkgo, big cone pine and pine needles significantly inhibited the growth of Microcystis from the early days to the stages of log-Phase. Waterchestnut was the most inhibitory to the growth of Microcystis. Pine needles inhibited in 85% of the algal growth: ginkgo in 80%; big cone pine in 75%; waterchestnut in 78%; wildrice in 59%; and iris in 30%. At the treatment with 0.25 g dried plants/l, algae was declined at a rate of 90% by waterchestnut: 53% by pine needles. Phenolic compounds were purifled from decomposing big cone pine and waterchestnut.

• Horticultural Science & Technology
• /
• v.18 no.6
• /
• pp.811-814
• /
• 2000

Effects of kanamycin concentration on regeneration and rooting of transgenic 'McIntosh Wijcik' were investigated to establish the efficient Agrobacterium-mediated transformation system. Relatively high regeneration frequency of explants appeared even at the high concentration of $150mg{\cdot}L^{-1}$ kanamycin, but the regeneration frequency and the number of normal shoots decreased significantly at a concentration of higher than $100mg{\cdot}L^{-1}$ kanamycin in the gelrite-gellifying medium. Rooting response varied with the transgenic lines in the agar-solidifying medium supplemented with the different concentrations of kanamycin and they were grouped with the inhibition level at $30mg{\cdot}L^{-1}$ concentration. No correlation between copy number and root response was observed. The optimum concentrations of kanamycin for the regeneration of 'McIntosh Wijcik' apple in the medium gellified with gelrite and for indirect-selection of putative transformants in the rooting medium solidified with agar were found to be $100mg{\cdot}L^{-1}$ and $30mg{\cdot}L^{-1}$ respectively.

• Journal of Korean Society on Water Environment
• /
• v.23 no.2
• /
• pp.179-183
• /
• 2007

This study was carried out to evaluate water quality based on physicochemical properties, including ammonium nitrogen ($NH_3-N^+$), nitrate nitrogen ($NO_3-N^-$), consumption of $KMnO_4$ and microbial indicators, such as total colony counts and total surveyed a group of 30 samples three times in 2005 (January to March, July to September, October to December). The mean concentration values of ammonium nitrogen ($NH_3-N^+$), nitrate nitrogen ($NO_3-N^-$) and the consumption of $KMnO_4$, were 0.01 mg/L (range 0.00~0.09 mg/L), 0.48 mg/L (range 0.00~3.31 mg/L) and 0.61 mg/L (0.0~3.42 mg/L), respectively. Based on the results, total colony count was detected in the ranges of 0~412 CFU/mL. In details, 84.4% of test samples was ${\leq}30CFU/mL$, 10.0% was 30~100 CFU/mL and 5.6% was ${\geq}100CFU/mL$. The detected rate of total coliforms was 6.6%. In conclusion, the ground water quality of 30 military facilities in Seoul, Kyunggi-do, and Inchon-city was acceptable for drinking except for a few detection of total colony count and total coliforms over standard.

• Plant Resources
• /
• v.8 no.3
• /
• pp.258-262
• /
• 2005

In autumn, to determine the optimal planting date and plant density of rapeseed in southern areas of Korea, Yudal variety for autumn sowing, the highest yielding variety was grown under three different planting dates and five different plant densities. Yield components such as plant height, ear length, number of seedling stand per $m^2$, number of branches and pod length were highest at the plots with Sep. 30 of planting date and 30/20 cm drilling of plant density. Yield of seed, oil and 1,000 grains weight were highest at the Sep.30 of planting date and 30/20 cm drilling of plant density. Judging from the results reported above, at optimum planting date and plant density of rapeseed seemed to be Sep.30 of planting date and 30/20cm plant density in autumn sowing.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.15 no.1
• /
• pp.171-177
• /
• 2007

In order to investigate the effect of the methanogenic bacteria in bacteria in leachate on the degradability of landfill waste, this study has created 4 cylinder-shape PVC lysimeters (Diameter: 30cm, Height: 200cm, Volume: 140L) and for the biological treatment and recirculation of the leachate, two anaerobic batch reactors (Diameter: 20cm, Height: 30cm) were created. To simulate a conventional landfill, no recycling was done in L1. In L2, 1,068ml of leachate (twice of rainfall amount) was recycled. In L3 and L4, the leachate was anaerobically digested in a dark room (with $35{\pm}1^{\circ}C$) for a week and them recycled by 1,064ml and 2,128ml, respectively, with recycled water only. In terms of cumulative $CH_4$ production, however, L3 and L4 were much higher (three times) than L1 and L2. Between L3 and L4, the latter was 1.23 times higher than the former in terms of cumulative CH4 production. In other words, the more the methanogenic bacteria-activated leachate is recycled, the more active the degradation due to active methane fermentation by the recyled methanogenic bacteria. And methane recovery is different according to the amount of recycled the methanogenic bacteria in leachate.

• Korean Journal of Veterinary Research
• /
• v.35 no.4
• /
• pp.863-868
• /
• 1995

Electroacupuncture therapy was performed in 2 dogs with thoracolumbar disc disease. Case was a 3-year-old female chihuahua with a calcified disc between the 13th thoracic and 1st lumbar vertebrae. Treatment was done by electroacupuncture at San sho yu, Shen yu, Huan tiao and Fu yang-San yin jiao with the current of 0.5~8 volts, 30 Hz for 30 min. She could pass feces and urine 2 days, and walk 9 days after the beginning of the therapy. Case 2 Was a 6-year-old male cocker spaniel with 4 calcified discs(T12-T13, T13-L1, L2-L3 and L6-L7) and spondylosis(lumbosacral junction). Treatment was done by electroacupuncture at Tian ping, Bai hui and Pung kung yu with the current of 2~4 volts, 30 Hz for 20 min. He could pass feces 6 days, urine 8 days, and stand 21 days, after the beginning of the therapy.

• Journal of Forest and Environmental Science
• /
• v.30 no.1
• /
• pp.126-132
• /
• 2014

This experiment was conducted to establish the in vitro propagation of Dendrobium moniliforme through protocorm like body (PLB) induction from the culture of leaf, stem and root explants. Frequency of PLB formation from root explants was higher than those of leaf and stem explants. PLB's proliferation in MS medium including 1.0 mg/L NAA was better than 1.0 mg/L IBA. Frequency of PLB's proliferation on medium with various concentrations of BA, Kinetin, Tidiazuron (0. 1.0, 3.0 mg/L) and NAA (0, 1.0 mg/L) was tested. The maximun proliferation of PLB's was obtained on MS medium supplemented with 3.0 mg/L BA and 1.0 mg/L NAA after 6 weeks of culture. Addition of 200 mg/L activated charcoal (AC) and 30 g/L sucrose was effective on PLB proliferation for D. moniliforme.

• Biomedical Science Letters
• /
• v.30 no.2
• /
• pp.96-99
• /
• 2024

In vitro antimicrobial activities of hot water extracts of Chamaecyparis obtuse, for clinical metallo-β-lactamase-Producing Pseudomonas aeruginosa (MBLPA.) was compared to commonly used conventional antimicrobial agents. All MBLPA was susceptible to colistin or amikacin, but also to imipenem 88.6%, meropenem 100%, piperacillin 85.7%, ceftazidime 97.1%, gentamicin 97.1%, and ciprofloxacin 100% were non-susceptible. MIC range to imipenem, meropenem, cefotaxime, ceftazidime, gentamicin, and ciprofloxacin for MBLPA were each 1 - >128 ㎍/mL, 4 - >128 ㎍/mL, 4 - >128 ㎍/mL, 8 - >128 ㎍/mL, 4 - >128, and 2- >128 ㎍/mL. MIC range to aztreonam for MBLPA were 1 - 128 ㎍/mL. MIC₉₀ to imipenem, meropenem, cefotaxime, ceftazidime, gentamicin, and ciprofloxacin for MBLPA were each 32 ㎍/mL, >128 ㎍/mL, >128 ㎍/mL, >128 ㎍/mL, >128 ㎍/mL, and 128 ㎍/mL. MIC₉₀ to colistin and amikacin were each 1 ㎍/mL and 64 ㎍/mL. The hot water extracts of C. obtuse leaf had the lowest MIC range (0.25 - >0.5 μL/mL), MIC₅₀ (>0.5 μL/mL), and MIC₉₀ (>0.5 μL/mL) of the clinical MBLPA tested, and it was possible more potent than various conventional antimicrobial agents for MBLPA infection patients. Therefore, it suggested the possibility of using extract components of C. obtuse or their derivatives to treat MBLPA infection patients.

• Fisheries and Aquatic Sciences
• /
• v.13 no.1
• /
• pp.71-78
• /
• 2010

We investigated the effect of Cu exposure on the activities of protective antioxidant enzymes in the gills and digestive glands of the manila clam Ruditapes phillippinarum exposed to subchronic concentrations (0, 20, 40, and $80{\mu}gL^{-1}$) of waterborne Cu. No mortality occurred during the experimental period, and no significant condition index differences were observed in any exposure group compared with the control. No significant differences were observed in the digestive glands and gills of the clams observed during 15 days of exposure, but after 30 days, the SOD activity in the gill showed a significant difference between the $80{\mu}gL^{-1}$ Cu-exposed group and the control. GPx activities in the digestive glands and gills were significantly lower after 30 days of Cu exposure. Gill GR activity in the high-exposure group ($80{\mu}gL^{-1}$) was significantly elevated compared with that in the control group. GST activities in the digestive glands of all groups did not change over 30 days. However, GST activity in the gill at $80{\mu}gL^{-1}$ Cu was significantly higher after 15 and 30 days of exposure. GSH activities in the gill showed patterns similar to those of GST activities during exposure periods. In the digestive glands, GSH activity was higher only at $80{\mu}gL^{-1}$ after 30 days exposure. In digestive glands and gills, the MDA levels of clams exposed to $80{\mu}gL^{-1}$ Cu were significantly higher after 30 days of exposure.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.6
• /
• pp.484-488
• /
• 1987

The model experiments were performed in tile circular water tank on the simple cambered and the super-V otter boards attached with the slotted fowler flap at the trailing edge in order to develop more efficient shearing characteristics. The dimension of the model otter boards was varied slightly in the flap chord ratio $0.20\~0.22$ and in the area $432\~426cm^2$ in accordance with the flap angle $30\~50^{\circ}$. The maximum shearing coefficient $C_L=1.78$ and hydrodynamic efficiency $C_L/C_D=4.0$ in the superV type were higher than their efficiencies $C_L=1.75$ and $C_L/C_D=3.7$ in the simple cambered type. As the shearing forces of the otter boards with flap were increased $20\~30\%$ mere than these without flap in spite of increasing the drag and the instability. The effect of flap should be fully investigated for the application.