• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.147-153
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• 2007

Kaolinite [$Al_2Si_2O_5(OH)_4$] was successfully synthesized by a hydrothermal process from amorphous $Al(OH)_3$ and $SiO_2$ at $230^{\circ}C$ under the pressure of $30 kg/cm^2$. The experiments were performed varying temperatures ($180{\sim}280^{\circ}C$), pressure ($10{\sim}60kg/cm^2$), chemistry ($Al_2O_3/SiO_2 = 0.5{\sim}0.38$) and pH ($0.3{\sim}9.5$) of the solution. The autoclaving was carried out in a closed stainless steel vessel. Kaolinite appears from the starting composition of $Al_2O_3/SiO_2= 0.5$ with boehmite and was stable as a single phase with the composition of $Al_2O_3/SiO_2=0.45$. Boehmite was a stable phase below $200^{\circ}C$ for the 240 h period of autoclaving, but kaolinite appeared even in 20 h at $230^{\circ}C$. The single kaolinite phase of a good crystallinity was observed at pH ranging 2 to 6. That indicates that pH is one of the most critical parameters for the successful formation of kaolinite. The optimal molar ratio of $Al_2O_3$ to $SiO_2$ was determined to be 0.45. The XRD pattern of the synthesized kaolinite coincided with that of natural one and its morphology was the cluster type of the kaolinite crystals (diameter = ${\sim}3{\mu}m$), irrespective of starting material, composition and temperature.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.256-263
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• 2007

We performed the biochemical characteristics, molecular epidemiologocal analysis, and drug susceptibility test on V. vulnificus isolated from environmental sources in Incheon. For this study, 233 strains were isolated from seawater, sediment, shellfish. V. vulnificus isolates were divided into 15 biochemical groups, which were positive for ONPG and Amygdalin test. Among the 209 strains, 206 (98.6%) strains and 110 (52.6%) strains revealed positive for vvhA and viuB gene, and the viuB gene detection rates of V. vulnificus from seawater, shellfish and sediment were 48%, 48.5% and 61.6%, respectively. From disc diffusion test on 175 isolates, most of strains were sensitive to Imipenem (100.0%), Sulfamethoxazole/trimethoprim (98.9%), Tetracycline, Ciprofloxacin (98.3%), Ampicillin/sulbactam (97.1%), Ohloramphenicol (96.6%), Cefepime (94.9%) and Ceftriaxone (94.8%), multi-drug resistance rates was 31.5% of seawater, 34.4% of sediment and 29.2% of shellfish. PFGE was performed on 233 V. vulnificus isolates with the objective of investigating the extent of genetic diversity of these isolates in our region. We could find that at least 126 different PFGE patterns were generated according by 90% of similarity and 13 clusters by 58% of similarity. The major cluster was type I (44.6%) during the most of the year, and type J was frequent pattern in June and October. There were 9 distinct PFGE types in July, 8 types in August, 7 types in June, 6 types in September, 5 types in October 3 types in May and 1 type in March.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.300-310
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• 2006

Genomic DNA isolated from three geographical gizzard-shad (Konosirus punctatus) populations in Seocheon (SC), Busan (BS) and Gochang (GC) collected in the West Sea and the southern sea, respectively, off the Korean Peninsula, were PCR-amplified repeatedly. Eight selected decamer and 20-mer primers generated a total of 713 loci in the SC population, 791 in the BS population, and 732 in the GC population, with a DNA fragment size ranging from 100 bp to 2,800 bp. We identified 50 unique loci for the SC population, 70 unique loci for the BS population and 130 for the GC population: 120 shared loci for the three populations. There were 108 specific loci (15.1%) for the SC population, 74 (9.4%) for the BS population, and 67 (9.2%) for the GC population. Eight primers also generated 48 polymorphic loci (6.7%) for the SC population, 26 (3.3%) for the BS population, and 16 (2.2%) for the GC population. The similarity matrix ranged from 0.756 to 0.936 for the SC population, from 0.800 to 0.938 for the BS population, and from 0.731 to 0.959 for the GC population. The dendrogram obtained by the eight primers indicates three genetic clusters: cluster 1 (SEOCHEON 01~SEOCHEON 10), cluster 2 (BUSAN 11~BUSAN 20 and GOCHANG 23~GOCHANG 24), and cluster 3 (GOCHANG 21, 22, 25, 26, 27, 28, 29 and 30). As stated above, some individuals of the GC population appear to belong in BS population. When seeing this result, it was thought with the fact that some individuals of 2 populations seem to come and go partially. Thus, RAPD-PCR analysis revealed a significant genetic distance between the three geographical gizzard-shad populations. Using various decamer and 20-mer primers, RAPD-PCR may be applied to identify specific/polymorphic markers that are particular to a species and geographic population, and to define genetic diversity, polymorphisms, and similarities among geographical gizzard-shad populations.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.173-186
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• 2005

Genomic DNA was isolated from two geographic populations of largehead hairtail (Trichiurus lepturus) in Korea and the Atlantic Ocean. The eight arbitrarily selected primers were found to generate common, polymorphic, and specific fragments. The complexity of the banding patterns varied dramatically between primers from the two locations. The size of the DNA fragments also varied widely, from 150 bp (base pairs) to 3,000 bp. Here, 947 fragments were identified in the largehead hairtail population from Korea, and 642 in the largehead hairtail population from the Atlantic Ocean: 148 specific fragments (15.6%) in the Korean population, and 61 (9.5%) in the Atlantic population. In the Korean population, 638 common fragments with an average of 79.8 per primer were observed.; 429 common fragments, with an average of 53.6 per primer, were identified in the Atlantic population. The number of polymorphic fragments in the largehead hairtail population from Korea and the Atlantic Ocean was 76 and 27, respectively. Based on the average bandsharing values of all samples, the similarity matrix ranged from 0.784 to 0.922 in the Korean population, and from 0.833 to 0.990 in the Atlantic population. The bandsharing value of individuals within the Atlantic population was much higher than in the Korean population. The dendrogram obtained by the eight primers indicated two genetic clusters: cluster 1 (KOREAN 01~KOREAN 11), and cluster 2 (ATLANTIC 12~ATLANTIC 22). Individual KOREAN no. 10 from Korea was genetically most closely related to KOREAN no. 11 in the Korean population (genetic distance = 0.038). Ultimately, individual KOREAN no. 01 of the Korean population was most distantly related to ATLANTIC no. 16 of the Atlantic population (genetic distance = 0.708).

• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.104-113
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• 1991

This experiment was conducted to find the effect of calcium salts on the inhibition of 'Campbell Early' grape(Vitis labruscana B.) berry absicission induced by ethephon. Ethylene evolution, berry abscission rate, and fruit quality were examined. Several mineral contents were determinded in the berries and morphological changes of cells in abscission zone were also studied. 1. Calcium acetate($4.4-8.8g/{\ell}$) and calcium hydroxide($2.2-8.8g/{\ell}$) completely inhibited berry abscission when applied with ethephon 1,000 ppm while calcium chloride was less effective. 2. Ethylene evolution in the berries treated with ethephon alone reached to maximum peak one day after application. However, that peak in the treatment of ethephon with calcium acetate occurred 3 hours after application. 3. No decrease of ethylene production capacity was observed in the ethephon solution even when held up to 36 hours after preparation but the effect on berry abscission was significantly reduced. In contrast, ethylene production of the solution prepared with calcium acetate was greatly decreased along with the increase of holding time. The effect of calcium acetate in aged solution on the inhibition of berry abscission was not altered. 4. There were no differences in mineral contents such as Ca, Mg, and K between the berries sprayed with ethephon 500 ppm or not. Additional calcium accumulation was not found in the skin, flesh, and petiole of clusters sprayed with 3 kinds of calcium salts (1.5 g net Ca per liter) respectively when analyzed 2 weeks before maturity. 5. Ethephon (1,000 ppm) alone induced the development of abscission layer in petiole but those applied with calcium acetate (0.05 M) did not develop any distinct abscission layer 3days after treatment.

• Journal of Life Science
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• v.20 no.10
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• pp.1556-1562
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• 2010

This study examined the histopathologic and electron microscopic findings of aborted fetuses from pregnant dairy cows naturally infected with Neospora caninum (N. caninum) at four farms in Gongju city and Yeonki gun of Choongnam province. Systemic subcutaneous edema was observed in the aborted fetuses. The necropsy revealed considerable serosanguinous fluid in the body cavity of the aborted fetuses. Light microscopy showed the infiltration of many inflammatory cells consisting of macrophages, lymphocytes and mononuclear cells, accompanied by congestion, hemorrhage and necrosis of myocardiac cells and hepatocytes in the liver and heart of the aborted fetuses. In the liver, clusters of tachyzoites were formed in the cytoplasm of hepatocytes and the interstitial tissue. In the brain, many tissue cysts of various sizes were observed in the nerve cells and their adjacent areas. Tissue cysts had a round shape and contained a large amount of bradyzoite. In addition, there was diffuse gliosis accompanied by congestion and hemorrhage and focal necrosis in the brain. Infiltration of microglial cells were observed at the periphery of the focal necrosis and perivascular area in the brain. Electron microscopy showed that the tissue cyst wall had a thickness of approximately 1 ${\mu}m$ with an irregular shape. On the interior side, more than 100 bradyzoites with lengths of 2-5 ${\mu}m$ and widths of 1-2 ${\mu}m$ were observed. The nucleus of in the bradyzoites was located approximately 1-1.5 ${\mu}m$ anterior to the posterior tip of the zoite. In the cytoplasm between the nucleus and the posterior tip, there were many amylopectin granules, electron-dense small-sized and electron-thin large-sized round granules, homogeneously electron-dense rhoptries and micronemes oriented perpendicularly to the zoite pellicle. To summarize, tissue cysts were identified on electron microscopy from the aborted fetus from N. caninum seropositive pregnant cow by the ELISA. This led to the confirmed presence of N. caninum.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.12-23
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• 2019

The purpose of this study was to develop and study an experiential natural education program that could emphasize the importance of the natural environment by providing natural experience opportunities using the natural resources of the urban forest parks using Youngheung Park in Suwon, Gyeonggi Province as a target site. The research target was limited to Suwon Yeongheung Park, which had the potential to become a place for education, where urban forest conservation and sustainable use already coexist. The natural education resources derived by surveying and analyzing the basic environment and the ecology of plants and animals in Suwon Yeongheung Park were organized to establish program goals, directions, and themes. Suwon Yeongheung Park is a water-rich forest that forms an ecological system of wetlands, including rice paddies, muknon wetlands, and dungbun, near a valley area. The U-shaped walkway was smoothly formed along the ridge and includes Doran-gil, which is among the Palochrome Road, designated by the city of Suwon. The soil is acidic, with a pH 4.40, due to urban pollution and acid rain, and is not good for plant growth. Most of the artificial forests, natural forests, and arable land were found using land use and extant life surveys. Old trees were distributed in artificial forests, the oak clusters in natural forests, and the fields and darrinones were distributed in the arable areas. As the forest vegetation declined, the cedar forest was underway, and the cedar trees and red bean pear trees were cultivated due to their adaptability to the urban environment. There are 13 large of 180 sacks, one being 109 centimeters in diameter, the largest silvery tree, and 105 oak trees, provide food and shelter for animals. Six species of waterfowl that used the 22 kinds of forest wetlands, while four species of amphibians and two species of reptiles reside in the wetlands. Natural Monument No. 327, Mauryuk, Class II Endangered Wildlife, was also observed in the wetlands. Eight other species of surface dragonflies and three species of butterflies were observed. By systemizing the resources, members, and characteristics of the forest ecosystems in Suwon Yeongheung Park based on five criteria, the program for a hands-on natural education was presented with the aim of understanding the urban forest ecosystem in Suwon Yeongheung Park, having an affinity with the city, and recognizing its relationship with the community and society. However, further research is needed as there are limitations of research on programs characterized by different ages and classes.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.293-300
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• 2003

This study examined the foraging activities and the Influence of excessive foraging activity by B. ignitus workers on the quality of cherry-tomato fruits in cherry-tomato green-house. The peak time of pollination by B. ignitus worker was recorded at 8:00 and the average of foraging time on each flower was 11.7 secs. The total pollinating time of B. ignitus was 41 mins and 37 secs and its total number of visiting flowers was 195.2. The average time of staying on flowers was 8.8 ${\pm}$5.4 secs when two bumblebees were allowed to pollinate per Pyong (3.954 square yards) in the green house of tomatoes for 24 hours, but it was two times shorter (4.0${\pm}$3.1 secs) compared with that when one bumble-bee was allowed to pollinate per Pyong for one hour. The stamen color of tomato flowers visited by the bumblebee for one hour was brown while the stamen color for 24 hours was dark brown due to the frequent visiting. The average fruit bearing rate of the 4th-6th clusters of tomatoes visited for one hour was 48.9%, which was not significantly different from those allowed to visite for 24 hours. However, the number of seeds of flowers visited for 24 hours was 64.0, which was more than 55.3 seeds of flowers visited for one hour. The weight of fruit was 25.4 g and 24.4 g, respectively. The sweetness was not different significantly between one and 24 hours of visit (P > 0.05). The result revealed that end pro-duct of cherry-tomato was not influenced by over foraging activity of B. ignitus workers on tomato flowers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1618-1628
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• 2013

Relationships between fatty acids and tocopherols in conventional and genetically modified peanut cultivars were studied by gas chromatography with flame ion detector and high performance liquid chromatography with fluorescence detection. Eight fatty acids and four tocopherol isomers in the sample set were identified and quantified. Oleic acid and linoleic acid are major fatty acids and the ratio of oleic and linoleic acids ranged from 1.11 to 16.26. Tocopherols contents were 6.76 to 12.24 for ${\alpha}$-tocopherol (T), 0.08 to 0.39 for ${\beta}$-T, 5.28 to 15.02 for ${\gamma}$-T, and 0.17 to 1.17 mg/100 g for ${\delta}$-T. Correlation coefficient (r) for fatty acids and tocopherols indicated a strong inverse relationship between oleic & linoleic acids (r=-0.97, P<0.05) and positive relationships between palmitic & linoleic acids (r=0.95, P<0.05) and ${\gamma}$-T & ${\delta}$-T (r=0.83, P<0.05). Principal component analysis (PCA) of fatty acids and tocopherols gave four significant principal components (PCs, with eigenvalues>1), which together account for 85.49% of the total variance in the data set with PC1 and PC2 contributing 45.27% and 21.33% of the total variability, respectively. Eigen analysis of the correlation matrix loadings of the four significant PCs revealed that PC1 was mainly contributed by palmitic, oleic, linoleic, and gondoic acids, while PC2 was by behenic acid, ${\beta}$-T, and ${\gamma}$-T. The score plot generated by PC1-PC2 identified sample clusters in the two spatial planes based on the oleic and linoleic acids. The score plot PC3-PC4 didn't separate sample groups.

• Progress in Medical Physics
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• v.14 no.4
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• pp.211-217
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• 2003

The Principal component analysis (PCA) is a well-known data analysis method that is useful in linear feature extraction and data compression. The PCA is a linear transformation that applies an orthogonal rotation to the original data, so as to maximize the retained variance. PCA is a classical technique for obtaining an optimal overall mapping of linearly dependent patterns of correlation between variables (e.g. neurons). PCA provides, in the mean-squared error sense, an optimal linear mapping of the signals which are spread across a group of variables. These signals are concentrated into the first few components, while the noise, i.e. variance which is uncorrelated across variables, is sequestered in the remaining components. PCA has been used extensively to resolve temporal patterns in neurophysiological recordings. Because the retinal signal is stochastic process, PCA can be used to identify the retinal spikes. With excised rabbit eye, retina was isolated. A piece of retina was attached with the ganglion cell side to the surface of the microelectrode array (MEA). The MEA consisted of glass plate with 60 substrate integrated and insulated golden connection lanes terminating in an 8${\times}$8 array (spacing 200 $\mu$m, electrode diameter 30 $\mu$m) in the center of the plate. The MEA 60 system was used for the recording of retinal ganglion cell activity. The action potentials of each channel were sorted by off­line analysis tool. Spikes were detected with a threshold criterion and sorted according to their principal component composition. The first (PC1) and second principal component values (PC2) were calculated using all the waveforms of the each channel and all n time points in the waveform, where several clusters could be separated clearly in two dimension. We verified that PCA-based waveform detection was effective as an initial approach for spike sorting method.