• Current Research on Agriculture and Life Sciences
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• v.18
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• pp.1-7
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• 2000

This study was carried out to determine the effects of plant growth regulators on organogenesis from Cymbidium kanran and Cymbidium hybrida. Optimal rhizome formation from Cymbidium kanran was obtained on MS medium with 10 ppm kinetin+2 ppm NAA. and optimal protocorm formation from Cymbidium hybrida was obtained on MS medium with 10 ppm kinetin+0.05 ppm NAA. However, in this study the optimal media for the callus induction from both explants was not identified. Optimal shoot induction from rhizome of Cymbidium kanran was obtained on MS medium with 10 ppm BA+2 ppm NAA and 5 ppm BA+2 ppm NAA. Optimal shoot induction from protocorm of Cymbidium hybrida was obtained on MS medium with 10 ppm kinetin+2 ppm NAA.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.179-185
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• 1987

Laboratory studies were conducted to evaluate safening effect of CGA 123'407 (4,6-dichloro-2-phenyl-pyrimidine) against pretilachlor, butachlor, and benthiocarb in rice plants. Butachlor and benthiocarb at 50 ppm or higher concentrations significantly inhibited rice growth and pretilachlor gradually inhibited growth of rice plants with increase in concentration starting from 0.5 ppm. CGA 123'407 at 0.1 ppm or higher concentrations was effective in reducing injury of rice plants when butachlor and benthiocarb were applied at rate of 10 ppm. Rice injury from pretilachlor at 10 ppm was also reduced by addition of CGA 123'407 at 0.25 ppm or higher concentrations Herbicidal activity of pretilachlor, butachlor, and benthiocarb was not affected by mixture treatments of CGA 123'407.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.80-88
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• 1995

This survey has been conducted, mostly in inorganic ions, to get some basic data for the culture solution composition, analyzing water quality of some hydroponic farms. pH range was shown from 5.95 to 7.61 and the average of 6.75. Relatively wide range of EC, from 0.07 to 0.97 mS/cm and the average of 0.35 mS/cm were obtained. 19.5 percent of farms investigated showed over 0.5 mS/cm of EC, which means more careful culture solution composition and its management are needed in these farms. Na concentration ranged from 5.0 to 41.4 ppm and Cl concentration ranged from 10 to 99 ppm were shown and their average were 20.38 ppm and 35.16 ppm, respectively. Higher Na concentration compared to standard of 11.5 ppm was shown in 75% of farms and Higher Cl concentration compared to standard of 35.5 ppm was shown in 33.3% of farms. These concentration were considered rather high, which can cause salt accumulation in substrate mats. Ca and Mg concentrations were ranged from 1.60 to 131 ppm and 0.96 to 34.1 ppm, respectively. Average concentrations were 26.11 ppm in Ca and 8.10 ppm in Mg. In case of HCO$_3$, 24 to 295 ppm of concentration range and average of 63.13 ppm were obtained. Fe range was 0.01 to 0.87 ppm and its average was 0.14 ppm. This results showed that Fe elimination was necessary in well water.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.31-40
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• 2003

A research has been done for growing characteristics of Korean ginseng in Geumsan of Chungnam Province. It had been made to determine the transitional element concentrations of the rocks, divided by biotitic granite(GR) and phyllite(PH). The physical and chemical properties of their weathering soils and ginseng nursery soils were analyzed. The texture in the GR weathering and ginseng nursery soils were sandy clay, and the texture of the PH weathering and ginseng nursery soils were heavy or silty clay. The bulk densities of the GR and PH weathering soils were $1.21{\sim}1.32g/cm^3$ and $1.26{\sim}1.38g/cm^3$, respectively. Also, the bulk densities of the GR and PH ginseng nursery soils were $1.02{\sim}1.10g/cm^3$, respectively. The pH (4.80) of the GR weathering soil were lower than the pH of the PH(5.34) weathering soil. The pH in the 2 year and 4 year-ginseng nursery soil of the GR were 4.39 and 4.40. In addition, those of the PH were 5.24 and 5.34, respectively. The difference in pH of the two nursery soils could be from the pH difference between the two parent materials. The organic matter contents of the GR weathering soils(0.24%) were higher than those of the PH(1.02%) weathering soils. The organic matter of the 2 and 4 year-ginseng GR nursery soils were 0.87% and 1.52%, and of the PH nursery soils were 2.06% and 2.96%, respectively. The total nitrogen contents of the GR weathering soils were 259.43ppm and of the PH weathering soils were 657.22ppm. Those of 2 and 4 year-ginseng GR nursery soils were 588.04ppm and 657.22ppm and those of the PH nursery soils were 1037.72ppm and 1227.96ppm, respectively. The nitrate and ammonium contents of the GR weathering soils were the extremely small, and those of the PH weathering soils were 6.7ppm and 9.94ppm. Those of 2 year-ginseng GR nursery soils(223.09ppm and 26.96ppm) were higher than those of PH(19.46ppm and 8.23ppm) nursery soils. And those of 2 year-ginseng PH nursery soils(14.22ppm and 16.84ppm) were lower than those of PH(306.93ppm, 34.21ppm) nursery soils. The difference was due to fertilizer types and more deposits of nitrate after oxidation of ammonium. The phosphate contents of the GR and PH weathering soils were 14.41ppm and 38.60ppm. Those of GR 2 and 4 year-ginseng nursery soils were 46.89ppm and 102.44ppm and those of the PH nursery soils were 147.04ppm and 38.60ppm. The cation exchange capacities of the GR weathering soils were 12.34me/100g and those of the PH weathering soils were 15.40me/100g. Those of 2 and 4 year-ginseng GR nursery soils were 15.80me/100g and 7.70me/100g and those of PH nursery soils were 12.14me/100g and 12.83me/100g. All of exchangeable cation($K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$) contents in the nursery soils were higher than those in the weathering soils. The $SO_4{^2-}$ contents of the weathering soils in both of the GR(5.98ppm) and PH(9.94ppm) were higher than those of the GR and PH ginseng nursery soils. The $Cl^-$) contents of the GR and PH weathering soils were a very small and those of the nursery soils(2-yr GR: 39.06ppm, 4-yr GR: 273.43ppm, 2-yr PH: 66.41ppm, 4-yr PH: 406.24ppm) were high because of fertilizer inputs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.212-216
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• 1981

The growth of Lactobacillus bulgaricus treated with vanillin, ortho-vanillin and guaiaco1 was studied on synthetic medium in mechanically agitated chemostat culture, The exponential-phase growth rate exhibited a maximum at the cells treated with 50 ppm vanillin. That stimulation, however, appears to be an effect on growth rate rather than total cell growth. And the others were inhibited by the chemicals. Much greater inhibition in growth of the cells treated with 100 ppm of each chemical than oars treated with 50 ppm was observed after 25 hour fomentation. For aerobic microbes, the alcohol dehydrogenase reaction is enhanced for the reproduction of NAD, which consequently cause to stimulate fermentation. For micro-aerophilic microbes , however, the same effect was not observed at the present study at least in the case of cell concentration. However except f or one treated with 50 ppm vanillin the same effect was observed in the case of growth is to. From the result using the glucose as a substrate, it was found that the cell concentrations measured in terms of ultimate optical density (UOB/ml), were 0.96 and 0.92, when treated with 50 and 100 ppm vanillin; 0.40 and 0.45 when treated with ortho-vanillin 50 and 100 ppm: 0.49 and 0.47, when treated with guaiacol 50 and 100 ppm. The specific growth rates were 0.44, 0.15, 0.25, 0.29, 0.37, and 0.34; the specific production rates wire 0.33, 0.15, 0.16, 0.22, 0.28, and 0.26 and the glucose concentrations (g/1) after 25 hour fermentation were 23.5, 32.8, 31.5, 29.5, 28.0 and 28.8, these all in the same sequences as the first.

• YAKHAK HOEJI
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• v.23 no.1
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• pp.17-29
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• 1979

The total mercury content in the head hair of 87 dental personnel and 210 Seoul citizens as control was determined. 1) The mean value of mercury content in dentists (8.57ppm) was 3.3 times of Seoul male citizens (2.57ppm) and the median of the former (5.92 ppm) was higher than that of the latter (2.39ppm) by approximately 2.5 times. 2) The mean value of mercury content in dental nurses (5.79ppm) was 2.8 times of Seoul female citizens(2.11ppm) and the median of the former(4.62ppm) was higher than that of the latter (1.86ppm) by approximately 2.5 times. 3) The mean value of mercury content in Seoul citizens was 2.29ppm and the median was 1.98ppm. 4) There was no correlationship between the mercury content in the head hair of dentists and the length of dental surgery experience or the frequency of amalgam fiillings per day. 5) The mercury content of Seoul citizens was higher in the male than in the female. 6) It appears more meaningful to employ median values than mean values when the environmental pollution is considered.

• Journal of Aquaculture
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• v.8 no.3
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• pp.183-193
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• 1995

Blue tilapia, Oreochromis aureus swim-up fry were fed,0, 1, 10, or 60 ppm $17\alpha-methyltestosterone$(MT) for 30 days (sex reversal period). Fish that had been fed 0 ppm MT during the sex reversal period were subsequently fed 0 ppm MT (0-0), 10 ppm MT (0-10) or 60 ppm MT (0-60) for the next 57 days (post sex reversal period) ; fish that had been fed 60 ppm MT during the sex reversal period were subsequently fed 0 ppm MT (60-0), 10 ppm MT (60-10), or 60 ppm MT (60-60) during the post sex reversal period. One group was fed 1 ppm MT (1-1), while another group was fed 10 ppm MT (10-10) during the entire 87-day experiment. There was a significant inverse relationship between concentration of MT and percentage body protein and percentage body fat at the end of the sex reversal period, while there was a significant positive relationship between concentration of MT and percentage body moisture. MT treatment during the post sex reversal period had greater effects on body composition of males at the end of the post sex reversal period than did MT treatment during the sex reversal period. There was a significant inverse relationship between MT concentrations, during both the sex reversal and post sex reversal periods, and gonosomatic indices (GSI) in males. In females, there was a significant inverse relationship between MT concentrations during the post sex reversal period and GSI.

• Proceedings of the Korean Nutrition Society Conference
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• 2000.11a
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• pp.56-56
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• 2000

본 연구는 철분결핍과 caffeine섭취가 흰쥐의 혈당과 과산화에 미치는 영향을 알아보기 위해서 수행되었다. 생후 2주된 48마리의 Sprague-Dawley 수컷 흰쥐를 철분과 caffeine의 첨가 수준에 따라 6군으로 나누어 4주간 사육하였다(C0F0 : caffeine 0%, Fe 5 ppm diet, C1F0 : caffeine 1%, Fe 5 ppm diet, C4F0 : caffeine 4%, Fe 5 ppm diet, C0F1 : caffeine 0%, Fe 50 ppm diet, C1F1 : caffeine 0%, Fe 50 ppm diet, C4F1 : caffeine 0%, Fe 50 ppm diet).(중략)

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.60-64
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• 2009

Effects of $CO_2$ concentration (500, 800, 1,000 and 1,500 ppm) on the initiation and development of fruit body of Grifola frondosa on sawdust cultivation were studied. Optimum concentrations of carbon dioxide for the initiation and development of the fruit body showed the ranges from 500 to 800 ppm. Fruit body initiation was accelerated at lower than 800 ppm $CO_2$ exposure but the maturing of the fruit body was not influenced by above treated $CO_2$ concentrations. The higher ratio of primordial formation, faster fruit body initiation and higher yield were obtained at below 800 ppm of $CO_2$ level, whereas over 1,000 ppm of $CO_2$ levels showed abnormal and lower quality of fruiting bodies. Based on the above results, it is concluded that the favorable $CO_2$ level for bag culture of G. frondosa was below 800 ppm.

• Economic and Environmental Geology
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• v.26 no.4
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• pp.465-472
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• 1993

The heavy metal contents are more abundant in stream waters, paddy soils and rice plants in the vicinity of abandoned mines compared to the surrounding areas in the Kyungpook province. However, these contents tend to decrease with distance from mines, and show some variation under different geological and geochemical environments. The Sin-stream waters have high contents of Cu=4.9 ppm, Pb=0.1 ppm, Zn=3.5 ppm and other heavy metals (Ni, Co, Cd) at Dalsung abandoned mine and low contents of Cu=0.4 ppm, Pb=0.1 ppm, Zn=0.1 ppm and other metals= 0.002 ppm in the surrounding area. The high contents decrease in the downstream in the area of calcareous sedimentary rocks. The paddy soils have high contents of approximately Cu=51 ppm, Pb=83 ppm, Zn=211 ppm, and Cd=11.3 ppm in the vicinity of Gunwi abandoned mine but low contents of Cu=4.5 ppm, Pb=2.9 ppm, Zn=60 ppm and Cd=0.4 ppm in the surrounding area. The Dadeog abandoned mine also shows similar trends to Gunwi mine. The contents of heavy metals of rice plants are high in the roots but trends to decrease through stem+leaf and become low in brown rices.