• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.413-422
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• 1997

To know the food chain of an intertidal community, feeding habits of Acanthogobius elongata were studied by analyzing stomach contents. A. elongata were monthly collected and the environment conditions of the habitat were investigated in the intertidal zone of Naecho-do, Kunsan from July 1993 to June 1994. Ratio of stomach contents to weight of A. elongata was $1.78\%$, and fullness of stomach showed a similar value to ratio of stomach contents to weight. Fullness of stomach was increased twice a day in the morning and the afternoon. The most important food item was copepods amounting to $54\%$ of the total stomach contents. Of these, Paracalanus parvus was most abundant in spring, Calanus sinicus in summer, Acartia sp. in autumn, and Calanus sinicus in winter. Degree of overlapping for the food items between seasons was not very high, except between spring and summer. There were little differences in feeding habits among the size groups. For all size groups of A. elongata, the occurrence rates of copepods, decapods, molluscs and cirriped larvae were high. As the fish grows, those of amphipods, polychaete larvae, isopods, cumaceans and stomatopods increased gradually. The importance index of the major food items was in the order of Calanus sinicus, Corycaeus affinis and Acartia sp..

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.638-642
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• 2001

To investigate the production of $C_{21}$-steroids during the spawning period of spotted sea bass, Lateolabrax maculatus, we have incubated maturing and ovulating follicles with radiolabeled pregnenolone and $17\alpha$-hydroxyprogesterone for 24 hours. The resulting metabolites were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), When maturing follicles ($700\sim800{\mu}m$ in diameters) were incubated with radiolabeled precursors, $C_{21}$-metabolites were corticosteroids and $17\alpha$-hydroxy, $20\beta$-dihydroprogesterone ($17\alpha20\beta OHP$). When ovulation follicles ($1,000\sim1,150{\mu}m$ in diameters) were incubated with radiolabeled precursors, the major $C_{21}$-metabolites were $17\alpha20\beta OHP$, $17\alpha$,$20\beta$, 21-trihydroxy-4-pregnen-3-one ($17\alpha20\beta21P$), and corticosterone. Additional chromatography by TLC and HPLC confirmed the presence of radioactive $17\alpha20\beta OHP$ in the maturing follicles, and $17\alpha20\beta OHP$,$17\alpha20\beta21P$ and corticosterone in ovulating follicles. Although $17\alpha20\beta OHP$ was found in a small peak, the synthesis of this steroid suggests that it may play a role in regulating the oocyte maturation process. Whereas ovulation is regulated by both $17\alpha20\beta OHP$ and $17\alpha20\beta21P$ in the spotted sea bass. In addition, an unusual finding was the biosynthesis of corticosterone. Whether this production is responsible for the ovulation, and is an area requiring continued research.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.85-90
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• 2005

This study was conducted to investigated the major characteristics of genetically modified rice of 'Milyang 204' originated from Dongjinbyeo compared to a non-transgenic rice varieties Dongjinbyeo and Jun-ambyeo. Basta resistant transgenic rice lines carrying bar gene produced by the Yeongnam Agricultural Research Institute were evaluated for their agronomic characters. The transgenic Japonica rice of 'Milyang 204' showed inferior phenotypic traits compared to a non-transgenic rice variety Dongjinbyeo and Junambyeo. On the basis of UPOV (Union Internationale Pour la Protaection des Obtentions Vegetables) and NSMO(National Seed Management Office) the transgenic 'Milyang 204' showed difference in some traits out of some agronomic traits, such as leaf color, angle of flag leaf, number of spikelets, culm length, white core and white belly compared to the non-transgenic varieties rice.

• Korean journal of applied entomology
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• v.13 no.1 s.18
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• pp.41-45
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• 1974

A total of 230 apparently healthy looking potato stocks and 80 potato stocks with symptoms of virus infection were collected from various seed potato farms in Korea and the incidence of potato virus X (PVX), potato virus S (PVS), potato virus M (PVM) and potato virus Y (PVY) was determined by serological microprecipitin tests. Results obtained are as follows. 1. Serological microprecipitin test retreated the presence of PVX, PVS, PVM and PVY in a number of potato stocks grown for the production of seed potatoes in Korea. 2. The occurrence of potato virus M is reported here for the first time in Korea with experimental evidence. 3. Practically $100\%$ (290 stocks, of the apparently healthy looking potato stocks were demonstrated to be infected with both PVX and PVS. The infection percentages of potato stocks with combination of PVX, PVS, PVM and PVY were as follows. PVX+PVS+PVM:$10.3\%$, PVX+PVS+PVY:$4.5\%$, PVX+PVS+PVM+PVY:$1.03\%$ 4. Irish Cobbler and Shimabara, which are the two major potato varieties in Korea, appear to be symptomless carriers of PVX and PVS. However, when these varieties were infected additionally with PVY, usually severe symptoms resulted. 5. Serological microprecipitin technique appears to be highly suitable for early, quick and reliable diagnosis of PVX, PVS PVM and PVY. It is particularly suited for large scale testing of seed potato stocks for the presence of viruses mentioned above.

• Korean journal of applied entomology
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• v.51 no.1
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• pp.59-65
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• 2012

The black pine bast scale, $Masucoccus$ $thunbergianae$ (Hemiptera: Margarodidae), is a serious pest of the Japanese black pine, $Pinus$ $thunbergii$, in Korea. The distribution of the black pine bast scale was examined, looking overall at 686 towns (eup), townships (myeon) or neighborhoods (dong). There were Japanese black pine ($Pinus$ $thunbergii$) forests in 91 cities, counties (gun) and borough (gu), in seven provinces and three metropolitan cities during 2010. Black pine bast scale were found in 64.8% of cities or counties or borough (59) in 7 provinces and 3 metropolitan cities, and were distributed in all South Costal regions, Pohang in East Costal region and Boryeong in West Costal region. Chungcheongbukdo, Daejeon and Jeju did not have black pine bast scale. All the gu regions in Busan had black pine bast scale, of which the area with the highest prevalence was Haenam in Jeollanamdo (1.713 crawlers/0.785 $cm^2$). Songji-myeon had the highest occurrence rate (6.36 crawlers/0.785 $cm^2$) from the towns, township and dong. The density of black pine bast scale in twigs was highly correlated with percentage of the sample with scale (Correlation coefficacy=0.89).

• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.101-110
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• 2000

Population ecology of Rhynchocypris keumgangensis have been investigated at upper part of the Han River in Korea from January to December, 1995. The habitat was low water temperature and clean area, and stream form was Aa. The major cohabitation fish was Phoxinus phoxinus. The total lengths in this population indicated that below 40 mm group is one year old, 40~65 mm group is two years old, 65~80 mm group is three year and the 80 mm longer group is regarded over four years old. There were no differences in total length distribution between the female and the male. The males became sexually mature, when longer than 45 mm and females longer than 65 mm in total length. Spawning season was from April to mid May with the water temperature in $11{\sim}14^{\circ}C$ and the properous period was April. The mean number of eggs in ovary was 1,616. The sex ratio all the year round of the female to the male was 1 : 0.75. The current velocity of the spawning ground was 44 (20~80) cm/sec and water depth was 35 (5~70) cm. Eggs were laied in 5~15 cm deep underneath the immaculate pebbles (2~6 cm). Sex ratio of the female to the male was 1 : 6.90 for spawning behavior.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.5 no.1
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• pp.28-35
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• 1994

Research on biological aspects on adult depression has been subjected to more than 25 years of systematic research, while biologic investigations regarding childhood and adolescent depression are only now being initiated. Although no unifying, explanatory theory of the biologic etiology of childhood depression emerges from the results of studies reviewed above, the findings do support that biological factors may be involved in the genesis of childhood depression. The research reviewed in this paper suggests that age and pubertal factors have major effects in most biological markers of depression. Some of these markers, like sleep EEG and neuroendocrine markers should be broken down by decades during adult life span. Thus, although adult data are very valuable points of departure for biological research on child and adolescent depression, it is very hard to transfer the adult data to prepubertal children and adolescents, ignoring the biological changes that take place in growth and development, pubety and aging. A great deal of work in basic developmental neuroscience remains to be done. It will be crucial for further advances in this field to determine the normal patterns of neurotransmitter interaction in this age group and to study children at high risk for depression. It will be also crucial to use primate models of depressive illness in order to be able to answer the many queations that cannot be investigated in humans for ethical issues. Conclusively, much closer collaboration between developmental and neurobiological and behavioral studies in primates and in humans will be essential for further development.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.118-131
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• 2018

The forest vegetation of Juwangsan National Park, which is famous for its towering scenic valleys, was syntaxonomically described. The study adopted the $Z{\ddot{u}}rich$-Montpellier School's method emphasizing a matching between species composition and habitat conditions. A combined cover degree and the r-NCD (relative net contribution degree) were used to determine a performance of 265 plant species listed-up in a total of 52 phytosociological $relev{\acute{e}}s$. Nine plant communities were classified through a series of table manipulations, and their distribution and actual homotoneity($H_{act}$) were analyzed. Syntaxa described were Carex gifuensis-Quercus mongolica community, Athyrium yokoscense-Quercus mongolica communiy, Arisaema amurense-Quercus serrata community, Lespedeza maximowiczii var. tomentella-Quercus variabilis community, Tilia rufa-Quercus dentata community, Carex ciliatomarginata-Carpinus laxiflora community, Aristolochia manshuriensis-Zelkova serrata community, Onoclea orientalis-Fraxinus mandshurica community, and Carex humilis var. nana-Pinus densiflora community. A zonal distribution was reviewed and the altitude of about 700 m was the transition zone between the cool-temperate central montane zone (Lindero-Quercenion mongolicae region) and southern submontane zone (Callicarpo-Quercenion serratae region). Only 19 taxa were associated with r-NCD 10% or more, most of which were tree species occurring in the Lindero-Quercenion and some of which was a member of open forests. Species composition of forest vegetation was much less homogeneous, showing the lowest $H_{act}$. Nearly natural forests and/or secondary forests in the Juwangsan National Park were defined as a regional vegetation type, which reflects much stronger continental climate in the Daegu regional bioclimatic subdistrict, rhyolitic tuff predominant, and wildfire interference.

• Journal of the Korean earth science society
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• v.26 no.8
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• pp.759-770
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• 2005

The purpose of this study is to examine the Earth science content relevance of the 7th national science curriculum. For this purpose, we (1) analyzed science curriculum or content standards of Korea, California, England and Japan, (2) compared science textbooks of Korea and Japan, (3) conducted a nationwide survey to gather opinions from students, teachers, professors and textbook authors about the relevance of the science curriculum and textbooks. According to the results, the Earth science contents of the 7th national science curriculum were not appropriate in terms of the objectives of science curriculum and the needs of students and society. The main reasons include the equal division among physics, chemistry, biology and earth science, iack of connection due to fractionation of units, overly strict application of spiral curriculum, and redundant amount of activities and concepts to cover in the textbook. Major suggestions fir securing the relevance of Earth science contents are as follows: First, the science contents and the size of units at each grade level should be determined according to the students' characteristics, not by equal portion rule. Second, the excessive overlapping and repetition of contents due to the spiral curriculum should be avoided. In addition, the number of activities should be reduced and the quality of required science activities should be improved. Third, to raise students' interest in Earth science, real-life applications and real-world Earth science contents should be emphasized including natural disasters, safety, universe and space exploration, and natural resources. Lastly, considering one of the relevance criteria is feasibility, supports for schools and science teachers are needed to realize the goal of the intended science curriculum.

• Journal of Periodontal and Implant Science
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• v.42 no.6
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• pp.185-195
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• 2012

Purpose: (-)-epigallocatechin-3-gallate (EGCG) has been reported to exert anti-inflammatory and antibacterial effects in periodontitis. However, its exact mechanism of action has yet to be determined. The present in vitro study evaluated the anti-in-flammatory effects of EGCG on human periodontal ligament fibroblasts (hPDLFs) and human periodontal ligament stem cells (hPDLSCs) affected by bacterial lipopolysaccharide (LPS) extracted from Porphyromonas gingivalis. Methods: hPDLFs and hPDLSCs were extracted from healthy young adults and were treated with EGCG and/or P. gingivalis LPS. After 1, 3, 5, and 7 days from treatment, cytotoxic and proliferative effects were evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and bromodeoxyuridine assay, respectively. And then, the gene expressions of hPDLFs and hPDLSCs were observed for interleukin (IL)-$1{\beta}$, IL-6, tumor necrosis factor (TNF)-${\alpha}$, osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), and RANKL/OPG using real-time polymerase chain reaction (PCR) at 0, 6, 24, and 48 hours after treatment. The experiments were performed with the following groups for hPDLFs and hPDLSCs; 1) No treat, 2) EGCG alone, 3) P. gingivalis LPS alone, 4) EGCG+P. gingivalis LPS. Results: The 20 ${\mu}M$ of EGCG and 20 ${\mu}g/mL$ of P. gingivalis LPS had the lowest cytotoxic effects, so those concentrations were used for further experiments. The proliferations of hPDLFs and hPDLSCs increased in all groups, though the 'EGCG alone' showed less increase. In real-time PCR, the hPDLFs and hPDLSCs of 'EGCG alone' showed similar gene expressions to those cells of 'no treat'. The gene expressions of 'P. gingivalis LPS alone' in both hPDLFs and hPDLSCs were highly increased at 6 hours for IL-$1{\beta}$, IL-6, TNF-${\alpha}$, RANKL, and RANKL/OPG, except the RANKL/OPG in hPDLSCs. However, those increased gene expressions were down-regulated in 'EGCG+P. gingivalis LPS' by the additional treatment of EGCG. Conclusions: Our results demonstrate that EGCG could exert an anti-inflammatory effect in hPDLFs and hPDLSCs against a major pathogen of periodontitis, P. gingivalis LPS.