• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.184-191
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• 2018

During the breeding season, some Eurasian Oystercatchers (Haematopus ostralegus osculans) in Yubu Island foraged in the open mudflat area nearby the breeding ground, instead of the tide water line area, main feeding site throughout the year. We found significant differences in foraging behavior and prey species diversity between the two different feeding site types. Even though the birds took more steps for most probably searching preys, their feeding success was much lower in the open mudflat area than the tide water line area. The multiple peck and boring methods were more frequently adopted to catch polychaetes on the open mudflat area, whereas the single peck method was dominant and gastropods and bivalves were main preys in the tide water line area. This study suggests that the bird shows flexible foraging strategy of shifting feeding site, foraging behavior and preys for better reproductive success.

• Journal of Sericultural and Entomological Science
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• v.27 no.1
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• pp.1-11
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• 1985

In order to clarify the taxanomic position of a new microsporidia K79 which was isolated from the silkworm larvae, Bombyx mori L. in Korea in 1979, the following several experiments such as estimation of pathogenicity in different instar, histopathological examination under light and electronic microscope and examination of fine structure of the sporse were carried out and their result obtained are as follows. In the test of pathogenicity by oral inoculation, the new microsporidia K79 was lower than Nosema bombycis and the susceptibility of the new microsporidia to silkworm was getting lower as the silkworm larvae grew. The lesion of Silkworms' tissue which was infected with the new microsporidia K79 was found in the epithelial cells of trachea, fat body and silk gland cells. The developmental process of the new microsporidia K79 in vivo could be divided into the following five stages: sporoplasm, schizont, sporont, sporoblast, and spore. The process was just the same as the of N. bombycis, but its development was slower than that of N. bombycis. Several differences in the fine structure of the spore under electron microscope, which could be important keys for the classification of microsporidia, were obtained. Anchoring disk and polaroplast lamella of the new microsporidian spore were disclosed to be different from those of N. bombycis. An average number of polar filament coils of the new microporidian spore was 16 at an angle of 75$^{\circ}$. On the basis of various keys for the classification of microsporidia, the results obtained from various experiments proved that the newly isolated microsporidia should be classified into the Genus, "Nosema", nut is further classification for species should be conducted in the future. Therefore, it may be reasonable that the new microsporidia is temperally classified as Nosema sp. K79 considering the fact that it was discovered in Korea in 1979.a in 1979.

• Research in Plant Disease
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• v.23 no.3
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• pp.241-248
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• 2017

The purpose of this study was to develop rapid methods for distinguishing between Heterodera schachtii and H. glycines detected from chinese cabbage fields of highland in Gangwon, Korea. To do this, we performed PCR-RFLP and PCR with the primers set developed in this study for GC147, GC408 and PM001 population, H. schachtii, and YS224, DA142 and BC115 population, H. glycines. Eight restriction enzymes generated RFLP profiles of mtDNA COI region for populations of H. schachtii and H. glycines, repectively. As a result, treatment of two restriction enzymes, RsaI and HinfI, were allowed to distinguish H. schachtii from H. glycines based on the differences of DNA band patterns. The primer set, #JBS1, #JBG1 and #JB3R, amplified specific fragments with 277 and 339 bp of H. schachtii, 339 bp of H. glycines, respectively, while it did not amplify fragments from three root-knot nematodes and two root-lesion nematodes. Thus, the primer set developed in this study could be a good method, which is used to distinguish between H. schachtii and H. glycines.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.451-456
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• 1992

Seventeen antiserum identified by stormont method were used for investigation of appearance type of red blood cell in Cheju horse. Phenotype $A_1$, A', Z, $ZZ_2$, C, K, $P_1$, Q, R, S, $U_2$, X and $N_1$ were classified by Hemolytic reaction and agglutination in $E_2$, H, J and $T_1$, Hokkaido horse and Thoroughbred horse were compared with the type of red blood cell. The results obtained are as follows ; 1. According to the appearance frequency of red blood cell the phenotypes could be classified by 6 groups among horses tested; I group : C, $A_1$, $ZZ_2$, $E_2$, S, Q, II : $P_1$, $U_2$, X, III : A', R, IV : $T_1$, K, V : H, J, VI, $N_1$, Z. 2. In group I the type of C, $A_1$ and $ZZ_2$ showed the Similar frequency among horses but the type of $E_2$, S and Q was lower in Cheju horse than Hokkaido and Thoroughbred horse. 3. In group II there was no differences in the type of $P_1$ and among three species, but Thoroughbred horse was lowest as 11.2 percent than Cheju and Hokkaido horse. 4. The type of $U_2$ and X were highest in Cheju and Hokkaido horse but lowest in Thoroughbred horse. 5. The type of A' and R observed higher appearance frequency in Hoklcaido horse but in the Thoroughbred and Cheju horse appearance ratio were Strikingly lowered. 6. The type of $T_1$ and K was shown higher appearance frequency in Cheju and Thoroughbred horse similarily but lowered in Hokkaido horse. 7. In group V the type of H and J showed similarily as 30 to 40 percent in Cheju and Thoroughbred but no observation in Hokkaido horse. 8. The type of $N_1$ and Z which are group VI was great difference between Cheju and Hokkaido horse but higher in Hokkaido than Cheju horse while there was no observation in thoroughbred horse.

• Journal of Wetlands Research
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• v.2 no.1
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• pp.95-107
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• 2000

The population dynamics of Salix nipponica and S. koreensis and the sediment factors were investigated in the wetland of the Nam-River. Chinju. Gyongsangnam-do, Korea. Each population of S. nipponica and S. koreensis was divided into four stages during the riverbed sedimentation: the first stage of establishment by S. nipponica, the second stage of coexistence by S, nipponica and S. koreensis, the third stage of dominated by S. koreensis, while S. nipponica was decreased during the increase of the water table in the sediment, and the fourth stage of the climax by S. koreensis, while S. nipponica almost died when the water table was twice to the third stage. Tree height, age, and density of S. nipponica were decreased, while S. koreensis increased along the sedimentation. And the composition of understory species showed no differences in each stage. The water table and the clay content affected on the distribution of Salix spp. in each stage, according to the PCA. The water table and the clay content increased during the sedimentation, while the other factors were almost the same.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.1-18
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• 1996

There are many advantages when using IIF and DNA probe methods over anaerobic culture method in that they are time-and effort-saving, more precise and more sensitive. Furthermore, in IIF and DNA probe methods, the detection is possible only with small amount of bacteria, the quantitative analysis is possible, and the cell viability is not necessary. The purpose of this study is to observe the incidence of P.endodontalis by carrying out anaerobic culture, IIF and colony lift using DNA probe method respectively, and to compare these 3 methods in terms of effectiveness and sensitivity in order to identify the most effective detection method. 30 teeth with at least one clinical symptoms, with single canal, and with pulp necrosis were sampled. For sampling bacteria, access cavity was prepared after disinfecting tooth and its surroundings. Then the paper point was inserted up to the periapical area, leave there for a while, and finally it was placed into PRAS Ringer's sol. and PBS sol. In anaerobic culture method, P.endodontalis was identified by biochemical tests after subculturing black and brown colonies which were produced after 7 days of incubation on BAP and Brucella BAP in anaerobic chamber. To identify P.endodontalis in IIF method, species-specific polyclonal rabbit-antisera of P.endodontalis(ATCC 35406) was reacted with sampled PBS sol. dispensed onto glass slide, and then P.endodontalis was examined by phase contrast microscopy after incubating with Goat anti-rabbit lgG conjugated to Fluorescein isothiocyanate. For colony lift using DNA probe method, membranes were laid over colonies on the surface of BAP and were hybridized with cloned DNA probe of P.endodontalis. The existence of P.endodontalis was then identified by the methods of chemiluminescent detection and color metric detection. Black colony was found in 11 teeth out of 30 teeth and P.endodontalis was detected in 6 teeth (20 %) by anaerobic culture method, 16 teeth (53 %) by IIF method, and 7 teeth (23 %) by DNA probe method. IIF method is significantly better in detecting P.endodontalis than DNA probe method and anaerobic culture method. There was no significant differences between DNA probe method and anaerobic culture method. There was significant correlation between the formation of black colony and the existence of P.endodontalis. The probability of detecting P.endodontalis when black colony being present is 2.89 times higher than when not being present. There was significant relationship between the foul odor of clinical symptoms and P.endodontalis. The sensitivity of existing P.endodontalis when foul odor being present was 93.75 %, while the specificity of not existing P.endodontalis when foul odor not being present was 28.57 %. These results suggested that the probes of P.endodontalis will be used to decide the method and prognosis in endodontic treatments.

• Korean Journal of Environment and Ecology
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• v.24 no.5
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• pp.601-610
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• 2010

This study was carried out to classify vegetation structure of the southern and northern slopes in the Deogyusan National Park using TWINSPAN classification and DCCA ordination analysis. The vegetation on the southern slope was classified into Quercus mongolica community, Q. serrata community, Q. variabillis community, Pinus densiflora community, Carpinus laxiflora community, Cornus controversa community and Fraxinus mandshurica community. The vegetation on the northern slope was classified into Q. mongolica community, Q. serrata community, P. densiflora community, C. laxiflora community, Betula davurica community, C. controversa community, F. mandshurica community, B. costata community, Abies koreana community and Taxus cuspidata community. To find out important value in each slope, we took 103 districts on the southern slope and 137 districts on the northern slope. As the result, Q. mongolica was highest value in the southern and northern slopes, followed by P. densiflora, Q. serrata, Q. variabillis, Styrax obassia, Acer pseudosieboldianum in the southern slope, F. mandshurica, A. pseudosieboldianum, Q. serrata, C. laxiflora, C. controversa, C. cordata, Rhododendron schlippenbachii in the northern slope. Species distribution and ecological features had differences between the southern and northern slopes communities. As the result of DCCA ordination analysis, sea level and water availability had high correlation with community distribution. Besides, T-N, O.M., exchangeable Ca and pH did in the southern slope. And exchangeable Ca, pH also did in the northern slope.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1709-1714
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• 2004

The changes of microflora and enzyme activities in Alaska pollack sikhae were evaluated in 3 different temperature conditions, 5$^{\circ}C$, 2$0^{\circ}C$ and alternating temperature (stored at 5$^{\circ}C$ after 10 days of fermentation at 2$0^{\circ}C$), respectively. The number of proteolytic bacteria and 2 lactic acid bacteria including Lactobacillus sp. and Pediococcus sp. increased rapidly up to 10 days and composed major portion of total viable cell (TVC) in sikhae fermented at 2$0^{\circ}C$, whereas those of TVC were occupied by Lactobacillus sp., Pediococcus sp. and yeast after 10 days of fermentation. The major species of microflora in sikhae fermented at alternating temperature were, composed of Lactobacillus, Pediococcus and Streptococcus after 10 days of fermentation. Especially, Leuconostoc sp. was kept up to 27 days at 5$^{\circ}C$ than other temperature conditions (16 days). The activities of protease and lipase in acidic region (pH 3.0) were higher at 2$0^{\circ}C$ than at 5$^{\circ}C$ due to sensitivity of temperature, although those of protease and lipase in neutral region (pH 7.0) were not found any differences in both temperatures. Changing temperature condition from 2$0^{\circ}C$ to 5$^{\circ}C$ in alternating temperature inactivated protease activity, whereas lipase activity was still maintained during fermentation.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.346-357
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• 2013

In this study, it was conducted to produce wood pellets using domestic forest thinning residues and examine their quality according to Korean pellet quality standard. Raw materials were composed of larch and mixed broad leaves species. Based on the small-end diameter (6 cm), they were classified into four different types of raw materials such as LM (larch with middle diameter), LS (larch with small diameter), MM (mixed broadleaf with middle diameter), and MS (mixed broadleaf with small diameter). After crushing and drying process, wood pellets were produced by a ring-die type pelletizer using each raw material. Wood pellets made from four different types of raw materials were tested for their quality such as calorific value, moisture content, ash content, inorganic matters and so on. As results of quality analysis, the calorific values of all wood pellets were higher than 198 kcal/kg, and satisfied with the first grade of Korea wood pellet standard. The ash content was slightly increased after pelletizing. Mechanical durability of wood pellets was highly dependent on the types of raw materials. The quality differences among wood pellets were turned out due to different physical and chemical characteristics of raw materials even though the same pelletizing condition was applied.

• Korean Journal of Environmental Agriculture
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• v.4 no.2
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• pp.108-113
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• 1985

Aerial application tests with a biological insecticide (Thuricide$^{(R)}$) and two low toxicity insecticides, Diflubenzuron (Dimilin$^{(R)}$) and Triflumuron (Alsystin$^{(R)}$) were carried out against the fall webworm (Hyphantria cunea Drury). For experimental application by helicopter, dilutions of 30x and 45x Thuricide, 180x and 240x Alsystin, and 180x Dimilin were utilized. The solutions were applied at a rate of 30 liters per hectare. The results are as follows: 1) All treatments, Dimilin 25% wp, Thuricide wp, and Alsystin 25% wp, were found to very effec tive against fall webworm larvae. Percentages of mortality averaged between 93.9% and 97%. 2) No significant differences in percentages of larval kill were found between dilutions of Thuricide (30x and 45x) or Alsystin (180x and 240x). 3) Assessment of parasite densities in the treated areas 35 days after treatment indicated that percentages of reduction for all five species found, including Brachymeria lasus(Walker) (=obscurata [Walker]), were lower than for areas treated with the conventional insecticide Diplox$^{(R)}$ (trichlorfon) 25% wp. In particular, the percentage of reduction in Thuricide-treated areas was only 21% as compared with the untreated (control) areas. 4) Aerial applications of Dimilin were very effective and economical for control of the fall webworm by comparison with [aerial] applications of Thuricide.