• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.54-62
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• 2005

The present study was to determine how seasonal rainfall intensity influences nutrient dynamics, ionic contents, oxygen demands, and suspended solids in a lotic ecosystem. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of rainfall. Dissolved oxygen (DO) had an inverse function of water temperature (r = = = - 0.986, p<0.001). Minimum pH values of<6.5 were observed in the late August when rainfall peaked in the study site, indicating an ionic dilution of stream water by precipitation. Electrical conductivity (EC) was greater during summer than any other seasons, so the overall conductivity values had direct correlation (r = 0.527, p<0.01) with precipitation. Ionic dilution, however, was evident 4 ${\sim}$ 5 days later in short or 1 ${\sim}$ 2 weeks in long after the intense rain, indicating a time-lag phenomenon of conductivity. Daily COD values varied from 0.8 mg $L^{-1}$ to 7.9 mg $L^{-1}$ and their seasonal pattern was similar (r = 0.548, p<0.001) to that of BOD. Total nitrogen (TN) varied little compared to total phosphorus (TP) and was minimum in the base flow of March. In contrast, major input of TP occurred during the period of summer monsoon and this pattern was similar to suspended solids, implying that TP is closely associated (r = 0.890, p<0.01) with suspended inorganic solids. Mass ratios of TN : TP were determined by TP (r= -0.509, p<0.01) rather than TN (r= -0.209, p<0.01). The N : P ratios indicated that phosphorus was a potential primary limiting nutrient for the stream productivity. Overall data suggest that rainfall intensity was considered as a primary key component regulating water chemistry in the stream and maximum variation in water quality was attributed to the largest runoff spate during the summer monsoon.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.251-258
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• 2005

This study was conducted to examine the effect of application of pig manure slurry(PMS) for rye cultivation in Paddy-land on rice productivity The field experiments were carried out from 1999 to 2002 on well-grown rice in Paddy-land at Kimje, Chunbuk province in Korea. PMS was manufactured by the fermentation for 6 months in natural condition. Amount of PMS was adjusted equal to total nitrogen value relative to its value of commercial chemical fertilizers. The amount of PMS were spread evenly over the soil surface two times; first in the autumn (before sowing, end of November) and second in the spring(regrowth of rye, middle of March). The field plots were consisted of four kinds (PMS $100\%$ treatment, PMS $200\%$ treatment PMS $100\%$ treatment with half of CF (CF $50\%$), Full of CF treatment (CF $100\%$). The experiment was designed as a randomized complete block. Each treatment was replicated three times. Rices are customarily gown under tropical korean condition as annuals. The results obtained from this study were summarized as fellows. Panicle length of rice was shorter in PMS $100\%$ than other treatments. Ripening grain ratio was the lower in CF treatment. In treatment of PMS $100\%$ and PMS $200\%$, 1000 grain weight was a downward trend as compared to that of full of CF treatments, whereas number of grains per $m^2$ was increased as compared to other treatments. Number of panicles reveals that there is an increase in order; CF $50\% + PMS\;100\%>\;PMS\;100\%\;>\;CF\;100\%\;>\;PMS\;200\%$. Yield of milled rice showed hi인 in CF $100\%$ and $CF 50\%+ PMS 100\%$, but were was no significant difference among treatments. There were did not a regular tendency in the ratio of leaf sheath bright, however the ratio of lodging area was higher in $CF50\%+PMS\;100\%$ treatment than other treatments. Based on the results of this experiment, $CF 50\%+PMS\;100\%$ may be the most effective in rice productivity under application of PMS for rye cultivation in Paddy-land.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.197-205
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• 2013

This study established a method for preserving chicken primordial germ cells (PGCs) that enables long-term storage in liquid nitrogen ($LN_2$) for preservation of the species. The purpose of this study was to compare the effects of Ethylene Glycol (EG) and Propylene Glycol (PG) on viability of cryopreserved PGCs with vitrification in Korean Native Chicken (Ogye), and to fine should be find or to the optimal protocol for PGCs freezing. One of the important components of cryopreservation process is cryopreservation medium that plays a vital role in preventing cellular injury during freeze-thawing. Cryoprotective agents have been known to improve cell viability after freeze-thawing. PGCs obtained from the germinal gonade of 5.5~6 day (stage 28) chick embryos, using the MACS method were suspended in a freezing medium containing a freezing and protecting agents. Gonads were harvested from stage 28 chick embryos and pooled in groups of 10E embryos, contributing gonads to the cell suspension. The gonadal cells, including PGCs, were then frozen in 1 of the following cryoprotectant treatments: 2.5% EG, 5% EG, 10% EG, 2.5% PG, 5% PG, 10% PG, and 0% cryoprotectant as a control. Effects of exposure to vitrification solution and vitrification, with different concentrations of the cryoprotectant solution, were examined. After freezing and thawing, survival rates of the frozen-thawed PGCs from the 0, 2.5, 5, 10 and 15% EG plus FBS treatment were 44.24%, 64.51%, 85.63%, 80.51% and 73.52% (p<0.05), respectively. The viability of PGCs after freeze-thawing was significantly higher for 10% EG plus FBS treatment than for 10% PG + FBS treatment (p<0.05)(85.63% vs 66.81%). Therefore, these systems may contribute in the improvement of cryopreservation for a scarce species in birds preservation. This study established a method for preserving chicken PGC that enables systematic storage and labeling of cryopreserved PGCs in liquid N at a germplasm repository and ease of entry into a database. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.164-170
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• 2011

Amanita hemibapha is a kind of mycorrhizal mushroom which has a relation with host plants and environmental factors. For the purpose of studying the relationship between environmental factors and mushrooms, in this study we conducted to investigate the soil physicochemical properties, the distribution of plants and the diversity of mushrooms in Gwangyang, Chungdo and Daegu. Soil texture in habitate of Amanita hemibapha was Sandy Loam and Sandy Clay Loam which contains a high rate of sand. Soil pH was approximately 5.0 in all study sites. Total nitrogen contents, C/N ratio and available phosphate($P_2O_5$) were the highest at the Chungdo. However, Gwangyang and Chungdo represent similar Cation Exchange Capacity(C.E.C) and Daegu has much less than other areas. Exchangeable cations, $Ca^{2+}$ content was higher at Gwangyang and Chungdo than Daegu and $Na^+$ content was the highest at Chungdo among three sites. Daegu has much $Mg^{2+}$ contents followed by Chungdo and Gwangyang. Interestingly, $K^+$ content listed in reverse order of $Mg^{2+}$ at Gwangyang, Chungdo and Daegu. The main woody plants in study sites are confirmed as Carpinus laxiflora, Quercus mongolica, Q. serrata and Pinus densiflora. Quercus species are found as a common species in three study sites. Lastly, 8 family and 12 species of mushrooms are emerged in Gwangyang, also 8 family and 12 species and 5 family and 10 species are found in Chungdo and Daegu, respectively. Amanita pantherina, Boletus edulis, Tylopilus felleus and Marasmius maximus, which found in study sites, are also kind of mycorrhizal mushroom same as A. hemibaph. By using correspondence analysis, Q. mongolica, Q. serrata, Q. variabilis and C. laxiflora are expected to as a host plant of A. hemibapha.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.643-658
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• 1994

The sedimentary records of anthropogenic metal loads in the Suyeong Bay, Pusan were determined by combining the Pb-210 dating technique with the measurements of heavy metals in the sediment cores. The sedimentation rates of sediment particles ranged from $0.12\;to\;0.20\;g/m^2/yr\;or\;2.4{\sim}4.0\;mm/yr$ in accumulation rates. The lowest sedimentation rate was observed at station S3 which was characterized by a bottom with relatively low organic matter contents(e.g. TIL and TOC). Heavy metals showed generally higher concentrations at station S1 and S2 near the mouth of the Suyeong River than at station S3 and the outmost station S4. The contents of copper, lead and zinc in the sediment cores especially from station S1 and S2 began to increase around 1930, and were at their highest levels in the $1960{\sim}1970$ period as a result of increasing industrial activities. Concentrations of these heavy metals have slightly decreased since 1970, probably due to regulation of pollution discharge. The natural background levels of copper, lead and zinc in the sediments of this bay ranged $18{\pm}4ppm,\;28{\pm}6ppm\;and\;74{\pm}9ppm$, respectively, by averaging the contents in the sediment depths corresponding to periods between about 1900 and 1920 at the four stations. The total amounts of anthropogenic loads deposited in the sediments since about 1930 were estimated to be $9{\sim}291{mu}g/cm^2$ for lead, $165{\sim}1122{mu}g/cm^2$ for zinc and $20{\sim}208{mu}g/cm^2$ for copper. These values were remarkably high at stations S1 and S2 relative to the other two stations. At stations S1 and S2, the anthropogenic loads of lead, copper and zinc constituted $29{\sim}30\%,\;32{\sim}42\%\;and\;28{\sim}35\%$ of the total sedimentary inventories at the present day, respectively. These metal contents have a good correlation(r>0.7) with each other and cadmium measurements also show a positive linear relation with nickel or total organic nitrogen.

• KSBB Journal
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• v.17 no.1
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• pp.73-79
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• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.300-306
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• 1983

Effect on blast lesion development was investigated in rice cultivar Milyang 23 and Jinheung using two races of Pyricularia oryzae compatible or incompatible to each of two rice cultivars. Discase lesions were measured in rice when inoculated with inoculum mixed with compatible and incompatible races, inoculated with a compatible race following with an incompatible race and vice versa. Lesions were smaller when rice was incoulated with an incompatible race and then inoculated with a compatible race than those inoculated in the reverse way both at the inoculated site and at 3cm-upper part from inoculated spot. The results suggested that induced resistance might play a role in suppression of lesion development although such an effect appeared to be influenced by heavy application of nitrogen fertilizer.

• Journal of Life Science
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• v.13 no.3
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• pp.333-342
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• 2003

The pathogenic effort of high glucose, possibly in concert with fatty acids, is mediated to vascular complications of diabetes via increased production of reactive oxygen species(ROS), reactive nitrogen species(RNS), and subsequent oxidative stress. This study was carried out to investigate the suppressive effect of buchu(Allium tuberosum) on oxidative stress in streptozotocin(STZ)-induced diabetes in Sprague Dawley male rats. The effect of buchu supplementation (10%) on lipid peroxidation, and antioxidative defense system in blood and liver was compared among normal rats fed basal diet(normal) and diabetic rats fed basal diet(DM-control) or 10% buchu-supplemented diet(DM-buchu). Diabetes was experimentally induced by the femoral muscle injection of 50 mg STZ per kg of body weight. Animals were sacrificed after 4 wks of experimental diets feeding. The induction of diabetes by STZ elevated the level of lipid peroxidation represented by thiobarbituric acid-reactive substances(TBARS) and conjugated dienes in plasma, LDL, liver, and erythrocytes. 10% buchu-supplemented diet significantly reduced the levels of conjugated dienes in erythrocytes(p<0.05) and lowered TBARS in liver and LDL to the levels of control. Induction of diabetes by STZ elevated Mn-superoxide dismutase(Mn-SOD) activity and lowered activities of glutathionine reductase(GSH-red) and glutathionine peroxidase(GSH-px). Catalase activity was not affected by the induction of diabetes by STZ. However, buchu supplementation to diabetic rats significantly elevated catalase activity(p<0.05) and slightly elevated GSH-px and GSH-red activities in liver. GSH levels of blood and liver were lowered or not changed by induction of diabetes by STZ, respectively, while buchu supplementation to diabetic rats significantly elevated hepatic GSH level (p<0.05). In conclusion, it can be concluded that buchu might be a food source to attenuate oxidative stress in diabetic patients by inhibiting lipid peroxidation, by increasing hepatic GSH level, and by inducing anti-oxidative enzyme systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.113-118
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• 2016

This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of $0.8dS\;m^{-1}$, $1.6dS\;m^{-1}$, $3.2dS\;m^{-1}$ and $4.8dS\;m^{-1}$. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of $1.6dS\;m^{-1}$, 36.9% in of $3.2dS\;m^{-1}$, and 50.7% in EC of $4.8dS\;m^{-1}$. Root dry matter decreased to 35.8% in EC of $3.2dS\;m^{-1}$, and to 40.5% in EC of $4.8dS\;m^{-1}$. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, $P_2O_5$, $K_2O$ and, MgO in soils of different salinity. On the other hand, $Na_2O$ content was higher in the order roots> shoots> seed, and in the case of roots, $Na_2O$ content increased to 1.02% in soil salinity of $4.8dS\;m^{-1}$. However, up to soil salinity of $1.6dS\;m^{-1}$, the $Na_2O$ content of the seed was similar to that in plant grown in the Control conditions($0.8dS\;m^{-1}$). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately $1.6dS\;m^{-1}$, and seed produced from reclaimedland would be suitable for human consumption.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.621-626
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• 2002

The bacteriological and physicochemical analysis of sea water and sediments in south western part of Jinhae Bay was conducted. The samples were collected from 40 stations, which were established once a month from January to December, 2000. During the study period, the range of temperature was from 5.5 to $23.7^{\circ}C$, the concentration of chemical oxygen demand ranged from 1.20 to 1.55 mg/L, dissolved oxygen ranged from 3.7 to 9.1 mg/L, dissolved inorganic nitrogen ranged from 2.79 to 7.09 $\mu$g-at/L phosphate phosphorus ranged from 0.39 to 0.57 $\mu$g-at/L, and chlorophyll-$\alpha$g-at/L ranged from 4.28 to $9.66 mg/m^{3}$. The chemical oxygen demand, acid volatile sulfide and ignition loss of sediments in south western part of Jinhae Bay ranged from 0.04 to 0.40, from 24.23 to 35.52 mg/L and from 10.49 to $11.09\%$ respectively. The coliform group and fecal coliform MPN's of sea water in south western part of Jinhae Bay ranged from <3.0 to 1,600 MPN/1003nL (means <3.0 MPN/100 mL) and from <3.0 to 93 MPN/100 mL (means <3.0 MPN/ 100 mL), respectively. The coliform group was classified with IMViC reactions were analyzed. Two hundred eighteen strains that were obtained from sea water samples in south westen of Jinhae Bay represented Escherichia coli group, $61.9\%$; Citrobacter freundii group, $12.1\%$; Enterobacter aerogenes, $14.1\%$; and unknown, $11.9\%$.