• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.586-593
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• 2014

Newly reclaimed tidal land is known to be in low status of soil fertility. The incorporation of crop residue is an effective method to improve soil properties and fertility in reclaimed saline soils. The objective of this study was to evaluate the efficiency of rice straw (RS) application to improve physico-chemical properties of saline-sodic soil and its contribution to productivity of whole crop barley. Increasing rate of rice straw improved growth parameter related to yield of whole crop barley, which increased tiller number significantly (p<0.05).The yield increased by 15% (F.W) and 9% (D.W) in rice straw-amended plots. The content of soil organic matter (SOM) in the surface soil (0-20cm) with rice straw incorporation increased by 5~9% (RS 2.5~RS 7.5) compared to RS 0, in which the content of SOM decreased after two consecutive cultivations. Rice straw incorporation promoted soil physico-chemical properties and nutrient-availability of the test crop, as indicated in change in soil bulk density, porosity and increased nutrient uptake of plant. Especially, the P content and uptake of whole crop barley increased with increasing the rate of rice straw application. In conclusion, the rice straw application at rates of $5.0-7.5ton{\cdot}ha^{-1}$ in reclaimed saline soils effectively improved soil properties and crop productivity, which has potentials to reduce the loss of chemical fertilizers and facilitate the favorable condition for crop growth under adverse soil condition.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.44-51
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• 2012

This study was conducted to predict the rice yield loss and to determine the economic threshold levels for direct-seeding flooded rice cultivation from competition to the most serious perennial weeds, Cyperus serotinus Rottb. and Echinochloa crus-galli L. The rice yield loss model of C. serotinus and E. crus-galli were predicted as Y = 560 kg/(1+0.001883x), $r^2$=0.933, and Y = 507 kg/(1+0.001734x), $r^2$=0.867, respectively. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.001883 in C. serotinus and 0.001734 in E. crus-galli, respectively. Economic thresholds calculated using Cousens' equation were negatively related with the competitiveness of weed. The economic thresholds of C. serotinus and E. crus-galli were 15.5 and 2.3 plants per $m^2$, respectively.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.43-49
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• 2010

This study was conducted to predict the rice yield loss and determine the economic threshold levels for water direct seeded rice from competition of the most serious weeds, Scirpus juncoides Roxb. (bulrush) and Echinochlor crusgalli L. (barnyardgrass) in Daegu of Korea. To predict crop yield as a function of weed density used a rectangular hyperbola, and determine their economic threshold levels used the equation developed by Cousens. The rice yield loss model of S. juncoides was predicted as y = 466 / (1+0.00188x), $R^2$ = 0.933 and that of E. crusgalli was y = 458 / (1+0.02402x), $R^2$ = 0.973. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.001884 in S. juncoides and 0.02402 in E. crusgalli. Economic threshold calculated using Cousens' equation was negatively related to the competitiveness of weed. So that the economic threshold of S. juncoides was 13.4 and that of E. crusgalli was 1.07 plants per $m^2$.

• Membrane Journal
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• v.28 no.1
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• pp.31-36
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• 2018

The purpose of this study is to investigate the changes of sludge characteristics according to the changes of influent sewage flowrate in the advanced wastewater treatment processes including MBR, SBR, and $A_2O$. The ratio of the actual sewage flowrate to the design flowrate is decreased from 100% to 70, 40%, and 10%, and the specific denitrification rate and ammonia oxidation (nitrification) rate was measured. The specific nitrification rate of the sludge collected from the aeration tank of each process was measured at a similar value ($0.10gNH_4/gMLVSS/day$) in all three process under the condition of 100% of sewage flowrate. It has tended to decrease significantly as the sewage flowrate decreased from 70% to 40%. The specific denitrification rate was also decreased by ~50% as the sewage flowrate decreased. However, considering the total nitrogen concentration in the influent and the microbial concentration in the reactor, the changes in kinetic parameter did not affect overall nitrogen removal. Therefore, it can be concluded that stable nitrogen removal will be possible under low influent flowrate condition if the MLVSS concentration is kept high.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.177-181
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• 1994

The sequences of the cytoplasmic 5S rRNAs(EMBL accession number X73589 and X73890) from two polupores, Ganoderma applanatum and Schizopora paradoxa, were determined by the direct chemical method for sequencing RNA and compared to the sequences of 9 reported mushrooms. 5S rRNAs of Ganoderma applanatum and Schizopora paradoxa consisted of 118 bases and fit the secondary structure model of the 5S rRNAs of basidiomycetes proposed by Huysmans et al. Based on Kimura’s K_nuc values, the closest fungus to Ganoderma applanatum was Ceratobasidium cornigerum and the one to Schizopora paradoxa was Bjerkandera adusta. When the secondary structures of 5S rRNAs of 11 mushrooms were compared the base substitution occurred at helix regions more than at loop regions. When a phylogenetic tree was constructed using the Neighbor program of the PHYLIP package, it partially discriminated and separated the mushrooms of the Hymenomycetes by the order.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.285-295
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• 2006

Korean water quality standards for the protection of agricultural water uses were originally derived based on management of public water resource. They were not prepared to protect crop plants from contaminants, and therefore required water parameters in agricultural uses were excluded in current water quality standards. Korean water standards in river and lake have five levels, and level IV is correspondent to agricultural water uses. Currently, there is no Korean guidelines to protect crop plants from contaminants contained in agricultural water. In Canada, agricultural water guidelines are provided to protect crops from contaminants. In this study, agricultural water quality standards in Korea were compared with them in developed countries to evaluate the adequacy of Korean water quality standards for the protection of agricultural water uses. Additional water quality parameters in agricultural uses were also proposed. Suggested parameters include electric conductivity, sodium, chloride, boron, copper, iron, zinc, and microbiological quality, They are the required parameters to protect crop plants as well as human health. Current water quality standards in agricultural uses was not considered to be appropriate in terms of crop protection. Additional water parameters should be included in agricultural water quality standards.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1247-1247
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• 2001

Constituents of animal biofluids such as milk, blood and urine contain information specifically related to metabolic and health status of the ruminant animals. Some changes in composition of biofluids can be attributed to disease response of the animals. Mastitis is a major problem for the global dairy industry and causes substantial economic losses from decreasing milk production and reducing milk quality. The purpose of this study was to investigate potential of NIRS combined with multivariate analysis for cow's mastitis diagnosis based on NIR spectra of milk, blood and urine. A total of 112 bulk milk, urine and blood samples from 4 Holstein cows were analyzed. The milk samples were collected from morning milking. The urine samples were collected before morning milking and stored at -35$^{\circ}C$ until spectral analysis. The blood samples were collected before morning milking using a catheter inserted into the carotid vein. Heparin was added to blood samples to prevent coagulation. All milk samples were analyzed for somatic cell count (SCC). The SCC content in milk was used as indicator of mastitis and as quantitative parameter for respective urine and blood samples collected at same time. NIR spectra of blood and milk samples were obtained by InfraAlyzer 500 spectrophotometer, using a transflectance mode. NIR spectra of urine samples were obtained by NIR System 6500 spectrophotometer, using 1 mm sample thickness. All samples were divided into calibration set and test set. Class variable was assigned for each sample as follow: healthy (class 1) and mastitic (class 2), based on milk SCC content. SIMCA was implemented to create models of the respective classes based on NIR spectra of milk, blood or urine. For the calibration set of samples, SIMCA models (model for samples from healthy cows and model for samples from mastitic cows), correctly classified from 97.33 to 98.67% of milk samples, from 97.33 to 98.61% of urine samples and from 96.00 to 94.67% of blood samples. From samples in the test set, the percent of correctly classified samples varied from 70.27 to 89.19, depending mainly on spectral data pretreatment. The best results for all data sets were obtained when first derivative spectral data pretreatment was used. The incorrect classified samples were 5 from milk samples,5 and 4 from urine and blood samples, respectively. The analysis of changes in the loading of first PC factor for group of samples from healthy cows and group of samples from mastitic cows showed, that separation between classes was indirect and based on influence of mastitis on the milk, blood and urine components. Results from the present investigation showed that the changes that occur when a cow gets mastitis influence her milk, urine and blood spectra in a specific way. SIMCA allowed extraction of available spectral information from the milk, urine and blood spectra connected with mastitis. The obtained results could be used for development of a new method for mastitis detection.

• The Korean Journal of Applied Statistics
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• v.24 no.1
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• pp.115-125
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• 2011

By use of a mortality forecasting model and a life table, forecasting the average life expectancy is an effective way to evaluate the future mortality level. There are differences between the actual values of average life expectancy at present and the forecasted values of average life expectancy in population projection 2006 from Statistics Korea. The reason is that the average life expectancy forecasts did not reflect the increasing speed of the actual ones. The main causes of the problem may be errors from judgment for projection, from choice, or use of a mortality forecasting model. In this paper, we focus on the choice of the mortality forecasting model to inspect this problem. Statistics Korea should take a mortality forecasting model with considerable investigation to proceed population projection 2011 without the errors observed in population projection 2006. We compare the five mortality forecasting models that are the LC(Lee and Carter) model used widely and its variants, and the HP8(Heligman and Pollard 8 parameter) model for handling death probability. We make average life expectancy forecasts by sex using modeling results from 2010 to 2030 and compare with that of the population projection 2006 during the same period. The average life expectancy from all five models are forecasted higher than that of the population projection 2006. Therefore, we show that the new average life expectancy forecasts are relatively suitable to the future mortality level.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.4
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• pp.289-300
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• 2001

Telomerase is a ribonucleoprotein that synthesizes telomere repeats. It has been reported that activation of telomerase was associtated with immortalization, proliferative activity and carcinogenesis. Recently, telomerase activity has been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In neuroblastoma, breast carcinoma, gastric carcinoma, non-small cell lung carcinoma, close relationship has been reported between high telomerase activity and lymph node metastasis, tumor aggressiveness and poor prognosis. The purpose of this study is to investigate the clinical implication of telomerase activity assay as an adjunctive factor in decision-making on neck node management, speedy pre-operative judging on histologic malignancy grading. Thus we performed semi-quantitative assay of telomerase activity using Telomerase PCR ELISA $kit^{(R)}$(Boeringer Manheim, Germany) and evaluated correlation between telomerase activity and tumor size, neck node metastasis, Anneroth malignancy score and influence of pre-operative chemotherapy on its activity in 27 cases of oral squamous cell carcinomas and 18 cases of normal oral epithelium. Also, correlation between telomerase activities and PCNA indices was evaluated. The results were obtained as follows: 1. The telomerase activities were detected in 24 specimens out of 27 oral squamous cell carcinoma specimens (88.9%) and in 5 specimens out of 18 normal oral epithelium specimens (27.8%). The mean value of telomerase activities was $0.9793{\pm}0.3428$ in 24 oral squamous cell carcinoma specimens and $0.4855{\pm}0.1117$ in 5 normal oral epithelium specimens. The positivity rate and mean value of telomerase activities in oral squamous cell carcinoma specimens were significantly higher than those of normal oral epithelium specimens (p<0.05). 2. There was no significant correlation between total Anneroth malignancy score and telomerase activity (p>0.05), but points of mitosis index and depth of invasion were significantly correlated with telomerase activities (p<0.05). 3. The positive immunohistochemical staining for PCNA(proliferating cell nuclear antigen) was observed in 26 specimens out of 27 oral squamous cell carcinoma specimens and mean value of PCNA indices of 26 specimens was $53.67{\pm}26.46$. PCNA indices were significantly correlated with telomerase activities (p<0.05). 4. The mean value of telomerase activities was significantly higher in pathologic T3/T4 group than in T1/T2 group (p<0.01). There was no significant difference of mean value of telomerase activities between pathologic neck node positive group and negative group (p> 0.05). Pre-operative chemotherapy significantly lowered the telomerase activities (p<0.05). The above results suggested telomerase activity could be used as diagnostic marker and adjunctive parameter for judging on histologic malignancy in oral squamous cell carcinoma.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.945-951
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• 1998

Background: Although profound hypothermia with total circulatory arrest(TCA) is a valuable maneuver in cardiac surgery, its applications have been limited due to serious complications, especially cerebral damage. In this study, the possible role of creatinine kinase-BB(CK-BB), an index enzyme of ischemic cerebral damage, was assayed as a parameter for the assessment of the cerebral complications after TCA. Hemoglobin(Hb), ionized calcium(Ca++), and blood glucose levels were also assessed as clinical parameters involved in cerebral damage. Materials and methods: Among patients with congenital heart disease, 18 patients who had been operated on with TCA were randomly selected and divided into two groups: 6 with acyanotic and 12 with cyanotic heart disease. Arterial blood from each patient was collected before and after TCA at scheduled times(15 min., 30 min, 1, 2, 4, 8, and 12hr). The levels of CK-BB, Hb, Ca++, and blood glucose were assessed in each sample. Results: As a whole, correlation between CK-BB level and blood sampling time after TCA was not statistically significant. Also, the difference in the level of CK-BB after TCA was not significant between the acyanotic and cyanotic groups. The levels of Hb and CK-BB correlated significantly. Conclusions: The results, which showed no correlation between the alterations in CK-BB level and the TCA duration, suggest that the single assay of the CK-BB level is not a representative measurement for the assessment of cerebral damage after TCA. Also, the cyanotic congenital heart disease group is not more vulnerable to cerebral damage induced by TCA.