• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.19-23
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• 1983

Present studies were conducted to investigate the developmental stage and the location of embryos in the reproductive tract at various times after ovulation, the morphologically normal after thawing of embryos preserved in liquid nitrogen, and the survival after transferring frozen-thawed embryos. The results obtained were as follows: 1. Embryo stage and location in the reproductive tract after hCG administration. For the investigation of embryo stage and location in the reproductive tract after ovulation, rabbits were laparotomized at 24, 40, 48, 72 and 120 hrs post hCG injection, simultaneously with mating. the oviducts and uteri were flushed out with PBS medium containing 50% rabbit serum, respectively. 1) Most of embryos was remained in the oviduct within 48 hrs, with the lapse of time, embryos were started to move to uterus and shifted in uterus at 72 hrs after hCG injection. 2) The representatives of embryos stage collected at 24, 40, 48, 72 and 120 hrs were 1-cell(60.4%), 8-cell to early morula (52.3, 39.3%), late blastocyst (95.5%) stages, respectively. 2. Morphological normality and survival of the frozen-thawed embryos. For the evalution of the quality and viability on the frozen-thawed embryos, immediately after thawing, embryos were assessed by morphologically normal under a dissecting microscope, and a further test of frozen-thawed embryos was made by transferring the morphologically normal embryos to the uteri of recipient rabbit induced pseudopregnancy by the injection of hCG at the time of hCG injection in donor rabbits. 1) The propotions of embryos which a, pp.ared morphologically normal was higher when 8-cell (85.7%) and morula(90.5%) were used for freezing than when 4-cell (66.7%) and blastocyst (75.8%) were used. 2) Preganacies were observed at Day 15 after transfer of frozen-thawed 8-cell (7/13), morula (19/42) and blastocyst (3/19) but not after transfer of embryos at 4-cell stage.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1691-1707
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• 2022

Cheonji Lake, the caldera of Baekdu Mountain, located on the border of the Korean Peninsula and China, alternates between melting and freezing seasonally. There is a magma chamber beneath Cheonji, and variations in the magma chamber cause volcanic antecedents such as changes in the temperature and water pressure of hot spring water. Consequently, there is an abnormal region in Cheonji where ice melts quicker than in other areas, freezes late even during the freezing period, and has a high-temperature water surface. The abnormal area is a discharge region for hot spring water, and its ice gradient may be used to monitor volcanic activity. However, due to geographical, political and spatial issues, periodic observation of abnormal regions of Cheonji is limited. In this study, the degree of ice change in the optimal region was quantified using a Landsat -5/-7/-8 optical satellite image and a Modified U-Net regression model. From January 22, 1985 to December 8, 2020, the Visible and Near Infrared (VNIR) band of 83 Landsat images including anomalous regions was utilized. Using the relative spectral reflectance of water and ice in the VNIR band, unique data were generated for quantitative ice variability monitoring. To preserve as much information as possible from the visible and near-infrared bands, ice gradient was noticed by applying it to U-Net with two encoders, achieving good prediction accuracy with a Root Mean Square Error (RMSE) of 140 and a correlation value of 0.9968. Since the ice change value can be seen with high precision from Landsat images using Modified U-Net in the future may be utilized as one of the methods to monitor Baekdu Mountain's volcanic activity, and a more specific volcano monitoring system can be built.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.191-198
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• 1985

Sixty one commercial seed samples of three cruciferous vegetable crops were examined for seed-borne Alternaria spp. by deep freezing blotter method. Alternaria raphani, A. brassicicola and A. brassicae were detected from 7, 6 and 1 seed samples of chinese cabbage out of 20 with average infection ratio of 3.8, 1.8 and 0.5, respectively. A. raphani and A. brassicae were detected from 11 and 2 seed samples of radish out of 38 with average infection ratio of 7.2 and 1.0, respectively. A. brassicicola was detected from 3 samples of cabbage seed with average infection ratio of 21.8. Most of the Alternaria spp. detected were recovered from the seed coat and caused seed rot and seedling infections. A. brassicicola was recovered from the embryos of radish, chinese cabbage and cabbage in low infections and A. raphani was recovered from the embryos of radish. In inoculation experiments, A. brassicicola, A. brassicae and A. raphani produced black leaf spots on old leaves of three creciferous vegetable crops and the spots gradually increased in size appearing gray to light brown lesions which later coalesce and caused defoliation.

• Korean Journal of Animal Reproduction
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• v.13 no.2
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• pp.113-120
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• 1989

In order to determine the sex of preimplantation embryos prior to transfer in cattle, a series of experiments were carried out using 45 Holstein donor cows to examine the ovarian response on the gonadotropin and PGF2${\alpha}$, and the morphology of fresh embryos or frozen/thawed embryos after deep freezing at -196$^{\circ}C$. The sexing of embryos treated with the medium containing H-Y antiserum(10%, v/v) and FITC anti-mouse IgG(10%, v/v) were analysed by chromosomal analysis, and the sex of the embryos which survived were ascertain after delivering the pups. The results obtained were summarized as follows ; 1. The average number of developed follicle and corpus luteum per cow were 13.5 and 8.1, and the ovalation rate was 60.1%. 2. Of 220-ova recovered, 75(34.1%) were morula and 91(41.4%) were blastocyst, and the morphological normal and abnormal rate of ova recovered were 75.5% and 24.5%, respectively. 3. Of 39 frozen/thawed embryos, the scores of normal morula and blastocyst, after thawing were 79.2%(19/24) and 73.3%(11/15). The average rate of frozen/thawed embryos which appeared morphologically normal post thawing was 76.9%(30/39). 4. The sex ratio was measured using the embryos treated with immunofluorescence assay to examine the relationship between embryo developmental stage, sex ratio of morula stage embryo was 42.2%(19/45) fluorescing and 57.8%(26/45) non-fluorescing, on the other hand, the ratio switched to 46.8%(29/62) fluorescing and 53.2%(33/62) non-fluorescing embryo in blastocyst stage. The sex ratio was also measured between fresh and frozen/thawed embryos, fresh and frozen/thawed treated embryos were indicated 45.8%(38/83) fluorescing, 54.2%(45/83) non-fluorescing and 41.7%(10/24) fluorescing, 58.3%(14/24) non-fluorescing. This trend indicated the approximal sex ratio was 1 : 1. 5. The result of karyotype test showed the successful rate of sexing embryo is fluorescing and non-fluorescing was 21.2%(7/33) and 29.6%(8/27). The female to male ratio within 33 fluorescing was 28.6 : 71.4, and the ratio of 27 non-fluorescing embryos was 87.7 : 12.5. 6. Of the embryo transferred after assignment of H-Y phenotype, five of the fluorescing embryos survived to term, all was males. Whereas six non-fluorescing embryos also survived to term and the sexes of the calves were 1 male 5 female.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1649-1656
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• 2015

Gene expression profiling has offered new insights into postmortem molecular changes associated with meat quality. To acquire reliable transcript quantification, high quality RNA is required. The objective of this study was to analyze integrity of RNA isolated from chicken skeletal muscle (pectoralis major) and its capability of serving as the template in quantitative real-time polymerase chain reaction (qPCR) as a function of postmortem intervals representing the end-points of evisceration, carcass chilling and aging stages in chicken abattoirs. Chicken breast muscle was dissected from the carcasses (n = 6) immediately after evisceration, and one-third of each sample was instantly snap-frozen and labeled as 20 min postmortem. The remaining muscle was stored on ice until the next rounds of sample collection (1.5 h and 6 h postmortem). The delayed postmortem duration did not significantly affect $A_{260}/A_{280}$ and $A_{260}/A_{230}$ ($p{\geq}0.05$), suggesting no altered purity of total RNA. Apart from a slight decrease in the 28s:18s ribosomal RNA ratio in 1.5 h samples (p<0.05), the value was not statistically different between 20 min and 6 h samples ($p{\geq}0.05$), indicating intact total RNA up to 6 h. Abundance of reference genes encoding beta-actin (ACTB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine-guanine phosphoribosyltransferase (HPRT), peptidylprolylisomerase A (PPIA) and TATA box-binding protein (TBP) as well as meat-quality associated genes (insulin-like growth factor 1 (IGF1), pyruvate dehydrogenase kinase isozyme 4 (PDK4), and peroxisome proliferator-activated receptor delta (PPARD) were investigated using qPCR. Transcript abundances of ACTB, GAPDH, HPRT, and PPIA were significantly different among all postmortem time points (p<0.05). Transcript levels of PDK4 and PPARD were significantly reduced in the 6 h samples (p<0.05). The findings suggest an adverse effect of a prolonged postmortem duration on reliability of transcript quantification in chicken skeletal muscle. For the best RNA quality, chicken skeletal muscle should be immediately collected after evisceration or within 20 min postmortem, and rapidly preserved by deep freezing.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.16-25
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• 1987

Colletotrichum acutatum, C. coccodes, C. dematium and C. gloeosporioides were detected in seed samples of red pepper (Capsicum annuum). C. dematium and C. gloeosporioides were the predominant species, maximum seed infection of the species in some samples were 84% and 28%, respectively. C. acutatum and C. coccodes were recorded only in low percentages of 1-2. The blotter method proved more suitable for detecting Colletotricum spp. than the deep freezing blotter or agar plate methods. Plating of seed components showed that C. dematium and C. gloeosporioides were recovered more frequently from seed coat, and decreasing amounts of infection were observed in the endosperm and cotyledon. Seed-borne C. dematium and C. gloeosporioides caused seed rot, damping-off, seedling blight and brown discoloration of cotyledon and hypocotyl when infected seeds were sown in agar of test tube or in soil. Inoculation experiments showed that C. acutatum was pathogenic to red fruit of red pepper and C. coccodes was highly pathogenic to red fruit and weakly pathogenic to leaf of the plant. C. dematium was highly pathogenic to leaf and green fruit and C. gloeosporioides was pathogenic to not only leaf but also green and red fruits. Host range of the four seed-borne species of Colletotrichum was also investigated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.445-450
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• 1983

To investigate the effect of harvest time after heading, storage temperature and duration on the dormancy and germination in barley cultivars, the kernels were collected at 5 day intervals from 20 days after heading until 35 days. The kernels were dried at 2$0^{\circ}C$ for 7 days and storaged in freezing chamber (-15$^{\circ}C$). The kernels germinated better at 15$^{\circ}C$ than at $25^{\circ}C$, and 1% $H_2O$$_2$ and 3 ppm GA$_3$ treatments gave much higher germination percentage than non-treatment; $H_2O$$_2$ and GA$_3$ treatments were good for promoting germination of immature harvested kernels. Germination rate index were significantly correlated with germination percentage under $25^{\circ}C$ and 15$^{\circ}C$ temperature conditions. Hangmi, Jogangbori and Muanbori had deep or slight dormancy at the different harvesting time, especially Dusan #8 had the deepest dormancy. The dormancy broke more rapidly under 3$0^{\circ}C$ than 2$0^{\circ}C$ storage conditions, so high temperature accelerated dormancy breaking. Those results showed that dormancy was various with the cultivars, harvesting time, storage temperature and storage duration.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.211-220
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• 2016

This study was to develop the analytical reference material of green-pepper for multi-residue analysis of pesticides. According to the ISO Guide 35, ISO Guide 13528 and EURL-PT protocol, the homogeneity, stability, assigned value and uncertainty were calculated to assess if it was suitable to be used as the proficiency test or quality control. The values of the within-bottle standard variation ($s_{wb}$) and the between-bottle standard variation ($s_{bb}$) were 1.7~3.7% of assigned value according to the requirement of the ISO guide 35. And, the uncertainty ($u^*{_{bb}}$) due to inhomogeneity was 0.8~1.1% for all pesticides. The storage stabilities of ten-pesticides at various conditions were assessed. For all target pesticides, the slop ($b_1$) values were smaller than the corresponding values of $[t_{0.95,n-2}{\times}s(b_1)]$ specified by the ISO guide 35, indicating that there were no statistically significant decreases in the concentration of the target pesticides when the analytical reference material was stored at room temperature ($20{\sim}30^{\circ}C$) for 7 days, freezing ($-20^{\circ}C$) for 30 days and deep freezer ($-80^{\circ}C$. except for bifenthrin, fenpropathrin) for 245 days. For proficiency test by using it developed by Korea Institute of Toxicology, inter-lab test was performed with eight organization performing the residual pesticide analysis. We found that there were some different results among them. Some were assessed as questionable or unacceptable for two pesticides and one organization didn't analyze the six pesticides. From these results, this green-pepper analytical reference material containing ten-pesticides could be used as a tool for the proficiency test to improve the reliability or consistency for pesticide residue's results.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.541-547
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• 1996

The previous monoclonal antibody labeling method for bone marrow immunoscintigrapy was complicated and laborious for clinical application. Also it showed a relatively low labeling efficiency. To improve this procedure, we compared several direct labeling methods of $^{99m}Tc$. 1) The labeling efficiency in the method using gluconate as a transchelator was low (40-70%), but immunoscintigraphy using this radiotracer produced a clear image. 2) To improve labeling efficiency, ${\beta}$-mercaptoethanol was removed after reduction. The labeling efficiency was improved up to 70-80%, but the radioactivity of the blood pool was high. 3) The higest labeling efficiency (>90%) and best quality images could be obtained by using MDP as a transchelating agent. It did not require additional procedures for separation of labeled antibodies. The immunoreactivity of this antibody was 60%. Residual MDP which can be taken up by the bone could be removed by PD-10 column. The reduced antibodies were stable with a high labeling efficiency (>90%) for up to 47 days by deep freezing. We concluded that the improved procedure for $^{99m}Tc$ labeling of anti-NCA-95 monoclonal antibody using MDP as a transchelating agent will be a simple and useful method for clinical application.

• Economic and Environmental Geology
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• v.24 no.2
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• pp.131-150
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• 1991

The Weolseong diatreme was temporally and spatially related to the intrusion of the Gadaeri granite, and was -mineralized by meteoric aqueous fluids. In the Nokdong As-Zn deposit, pyrite, aresenopyrite and sphalerite are the most abundant sulfide minerals. They are associated with minor amount of magnetite, pyrrhotite, chalcopyrite and cassiterite, and trace amounts of Pb-Sb-Bi-Ag sulphosalts. The AsZn ore probably occurred at about $350^{\circ}C$ according to fluid inclusion and compositional data estimated from the arsenic content of arsenopyrite and iron content of sphalerite intergrown with pyrrhotite + chalcopyrite + cubanite. Heating studies of fluid inclusions in quartz indicate a temperature range between 180 and $360^{\circ}C$, and freezing data indicate a salinity range from 0.8 to 4.1 eq.wt % NaCl. The coexisting assemblage pyrite + pyrrhotite + arsenopyrite suggests that $H_2S$ was the dominate reduced sulfur species, and defines fluid parameter thus: $10^{-34.5}$ < ${\alpha}_{S_2}$ < $10^{-33}$, $10^{-11}$ < $f_{S_2}$ < $10^{-8}$, -2.4 < ${\alpha}_{S_2}$ < -1.6 atm and pH= 5.2 (sericte stable) at $300^{\circ}C$. The sulfur isotope values ranged from 1.8 to 5.5% and indicate that the sulfur in the sulfides is of magmatic in origin. The carbon isotope values range from -7.8 to -11.6%, and the oxygen isotope values from the carbonates in mineralized wall rock range from 2 to 11.4%. The oxygen isotope compositions of water coexisting with calcite require an input of meteoric water. The geochemical data indicate that the ore-forming fluid probably was generated by a variety of mechanisms, including deep circulation of meteoric water driven by magmatic heat, with possible input of magniatic water and ore component.