• The Korean Journal of Ecology
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• v.10 no.2
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• pp.81-89
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• 1987

This study was carried out to inverstigate the oribatid fauna at Mt. Moak near Chonju, Korea. Samples were taken from 4 sites at the north sides, 200, 300, 500 and 600 above sea levels and south sides, 200, 400, 600, and 700m above sea levels. The results were as follows: Oribatid mites of 37 families, 62 genera, 118 species were collected in this study. Numbers of species were less at high level than at low level sites. Species diversity index was less at high level than at low level sites, and less at the south than at the north side. Species similarity index indicated that there are two types, i.e. "high sea level type", and "low sea level type" at Mt. Moak. According to the MGP analysis-I, most of the sites belonged to "Type G". "Group M" and "Group P" appeared more in the lower level sites.up P" appeared more in the lower level sites.ites.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.84-88
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• 2016

To understand the effects of habitat characteristics on the genetic diversity of Persicaria thunbergii, three sites of different environmental conditions in a water system were surveyed. Site A was the closest to the source of the water system, and there was a dam between sites A and B. Site C is located on the lowest downstream in the water system. Vegetation survey of four quadrats at each site was performed, and soil samples were collected for physicochemical analysis. Random amplification of polymorphic DNA (RAPD) analysis of ten P. thunbergii individuals at each site was conducted to calculate population genetic diversity and genetic distance among populations. Soil was sterile sand at site A, whereas loamy soil at sites B and C. A pure stand of P. thunbergii appeared at site A, while other species occurred together (such as Humulus japonicus and Phragmites australis) at sites B (Shannon-Wiener index; $H_B=0.309$) and C ($H_C=0.299$). Similar to the species diversity, genetic diversity (Nei's gene diversity; h) within population of site A ($h_A=0.2381$) was relatively lower than sites B ($h_B=0.2761$) and C ($h_C=0.2618$). However, site C was separated from sites A and B in genetic distance rather than the geographical distance (Nei's genetic distance; A~B, 0.0338; B~C, 0.0685; A~C, 0.0833).

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.495-502
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• 2007

Species biotic index (SBI), based on a fish assemblage, was applied to a stream assessment using long-term ecological fish data set (1996 to 2001) in Boryong dam area, which is located in the mainstream of Ungchun Stream of Chungnam province, Korea. According to the methods of Hilsenhoff (1988), the scores of tolerance guild assigned 10 classes to each species by its habitat and feeding guild, but modified current 7 criteria to 5 scoring standards due to unclear borderline among species. Relative abundance in the species number of upper stream guilds was only 7% of the total, whereas the abundance in the species number of middle to downstream upper stream guilds was 64%. Mean SBI, based on dataset in Site 1 during 1995-2001 averaged 5.10, which was judged as a "good" condition by the rank criteria of SBI. Before the dam construction, mean SBI in the Site 1 was 4.61, indicating a "good" condition, but after the dam construction, mean SBI was 5.60, indicating a "fair" condition. Trajectory analysis in the Site 1 showed significantly (One-way ANOVA, $F_{6,21}=3.26$, p=0.02) different among years, reflecting the changes of fish composition and population density by the dam construction, whereas Site 2 showed no significant changes ($F_{6,21}=1.00$, P =0.45) difference among years. Mean SBI prior to the dam construction in the Site 3 was 4.52 but after the construction, the value was 6.30, indicating a distinct difference between the pre- and post-dam construction. Trajectory analysis at the Site 3 supported this fact: Values of SBI showed significantly ($F_{6,21}$=14.37, p<0.01) different. Mean SBI was 4.67 in the Site 4, indicating a "good" condition in the health and the health rank was same as the sampling sites 1, 2, and 4. Trajectory in the Site 4 showed no significant ($F_{6,21}=2.35$, p=0.07) difference among the years. Overall, our trajectory analysis indicated that three of four sampling sites (sites 1, 3, 4) showed significant decreases (n=7, p<0.05) and that the proportions of sensitive species declined evidently in the sites 1 and 2 and the tolerant species increased in the dam sites. Our outcomes may be used as a key data for diagnosis of the long-term ecological impact in the future in the watershed.

• Korean Journal of Community Nutrition
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• v.12 no.4
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• pp.405-416
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• 2007

This study was to examine the needs among elementary school dietitians (n = 115) for developing a nutrition information internet site for children. A survey questionnaire included general characteristics, internet use regarding health and nutrition information, and needs for developing a nutrition information site. The mean age of the subjects was 36.2 years. The higher working experience group (> 10 years of working as dieticians) had higher mean age (p < 0.001), had a larger number of enrolled students at school (p < 0.01) and the number of those receiving school lunch (p < 0.01) than the counterparts (${\le}10$ years group). Sources of health and nutrition information were mainly PC/internet (60.4%) and seminar (14.4%). About 95% used health or nutrition information using the internet, however, the majority of users (71.6%) used internet information only when they needed it. Major reasons for using internet information was 'to get nutrition education materials' (63.8%) and 'to obtain general nutrition information' (21%). One third of the subjects were satisfied with nutrition information internet sites; major problems with internet sites were 'lack of content' (38.9%) and 'lack of practical information' (33%). These characteristics regarding internet use were not different between work experience groups. Major problems with nutrition education were 'lack of nutrition educational materials' (41.1 %) and 'lack of nutrition education skills' (32.1%). These were significantly different between the work experience groups (p < 0.01). Subjects preferred CD/internet to leaflet/booklet as nutrition educational materials. In developing nutrition sites for children, subjects wanted topics such as obesity assessment, dietary assessment, and obesity. Subjects responded that contents of nutrition information should be 'suitable to the children's knowledge levels' (31.1%), 'interesting enough by including quizzes, games and songs' (27.8%), 'inserting many illustrations/icons' (16.3%). In terms of designing internet sites for children, they wanted that internet sites should 'be easy enough to find the sites' (29.2%), 'use illustrations and characters' (24.8%), 'use communication channels such as Q&A' (18.7%). Needs for developing internet sites for children were not different by the work experience group. This study suggests that web sites for children should be carefully developed considering the contents and design, have less information with more illustrations, designed to induce the interest of children, as well as including sections such as eating habit assessment and games.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.212-219
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• 2004

To minimize the danger of soil erosion and settle habitats earlier, afforestation, which vegetates bare slopes, is selected as an environmental recovering technology. Large portions of these areas often are suffered by a bad germination and growth inhibition of sprayed seeds. Afforested materials collected in the normal and damaged sites were not any big difference in chemical characteristics and biological response to ryegrass. But background soil of the damaged site has very low pH (3.6) and high contents of iron and aluminum compared with them of the normal sites. Both germination and root growth of ryegrass were inhibited severely in the water extracts of damaged soils, but not in the water extracts of normal sites. Groundwater collected nearby the damaged sites was very strong acidic (pH 33) and exhibited a high value of electrical conductivity and high contents of iron and aluminum. In the ground water, germinated ryegrass was scarcely grown. In Al standard solution, the root growth of ryegrass was inhibited over 50% in 0.5 mM in pH 3.5-4.5 and in 1.4 mM in pH 5.5, which seems to be related to $Al^{3+}$ activity in solution. In the ferric Fe ($Fe^{3+}$) standard solution, ryegrass growth was inhibited over 50% in the concentration of 14-19 mM in root and 23-25 mM in shoot. This strong tolerance of ryegrass to $Fe^{3+}$ might be concerned with the very low activity of $Fe^{3+}$ at pH 3.5-5.5. In contrast, ryegrass responded very sensitively to ferrous Fe ion ($Fe^{2+}$), especially in root growth: $Fe^{2+}$ concentrations corresponding to 50% growth reduction were 0.3-0.4 mM at pH 3.5-5.5 in roots. This high growth inhibition should be related to the high ion activity of $Fe^{2+}$ irrespective of different pH conditions. In conclusion, low pH and high contents of $Fe^{2+}$ and aluminum seem to be caused by pyrite and be closely related to the growth inhibition of ryegrass seeded in afforested area.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.9
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• pp.955-960
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• 2006

Catalytic decomposition over HZSM-5 was carried out in semi-batch reactor to recover gasoline from waste plastics(HDPE). To enhance the liquid yield with a molecule range of gasoline, the properties of catalytic decomposition were investigated over a commercial Si/ZSM-5 catalyst and HZSM-5 catalysts modified with P and Mg. Optimum loadings of P and Mg on HZSM-5 were 0.5 wt% and 2.0 wt%, respectively, based on conversion and liquid yield. $NH_3-TPD$ profile indicated that strong and weak acid sites totally decreased in P loading on HZSM-5 catalyst, strong acid sites moderately decreased and weak acid sites sharply reduced in Mg loading on HZSM-5 catalyst. In the case of Si/ZSM-5 catalyst, all acid sites almost disappeared, subsequently, catalytic decomposition significantly decreased, and little liquid product was produced. When HZSM-5 catalyst was modified with P and Mg, the carbon distribution of liquid product was shifted to lower carbon number and its all components was within a molecular range of gasoline($C_5-C_{11}$). Especially, over Mg(2.0 wt%)/ZSM-5 catalyst, 55.8% of liquid yield with 100% of a molecular range of gasoline, was obtained at $400^{\circ}C$, suggesting it as a promising catalyst for recycle of waste plastics.

• BMB Reports
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• v.28 no.2
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• pp.94-99
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• 1995

The properties of binding sites in the active site of $Zn^{2+}$-glycerophosphocholine cholinephosphodiesterase were examined using substrates and inhibitors of the enzyme. Phosphodiesterase hydrolyzed p-nitrophenylphosphocholine, p-aminophenylphosphocholine, and glycerophosphocholine, but did not hydrolyze either acylated glycerophosphocholine or bis (p-nitrophenyl)phosphate, suggesting a size limitation for interaction with a glyceryl moiety-binding subsite. The hydrolysis of p-nitrophenylphosphocholine was competitively inhibited by glycerophosphocholine and p-aminophenylphosphocholine, while glycerophosphoethanolamine was a weak inhibitor. The enzyme was also inhibited by choline, but not by ethanolamine. Thiocholine, a much more potent inhibitor than choline, was more inhibitory than cysteamine, suggesting a strict specificity of an anionic subsite adjacent to a $Zn^{2+}$ subsite. Of all oxyanions tested, the tellurite ion was found to strongly inhibit the enzyme by binding to a $Zn^{2+}$ subsite. The inhibitory role of tellurite was synergistically enhanced by tetraalkylammonium salts, but not by glycerol. Deactivation of the enzyme by diethylpyrocarbonate was partially protected by choline, but not by glycerophosphate. It is suggested that the active site of phosphodiesterase contains three binding subsites.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.421-432
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• 1994

The local route of antibiotic administration can accomplish higher therapeutic doses in subgingival sites than those possible by systemic therapy. This investigation assessed on the clinical and microbiological effect of 30% Minocycline loaded polycaprolactone film (Mino-strip) on rapidly progressive periodontitis. Mino-strip was applied in the periodontal pockets of 15 patients with clinically diagnosed as a rapidly progressive periodontitis. 8sites for each patient with a 5mm probing pocket depth were selected in split mouth design and were assigned into group. i.e., placebo(group 1), supragingival scaling and R/P(group 2), Mino-strip applied only(group 3), R/P and Mino-strip applied(group 4). Supragingival scaling and oral hygiene instruction were performed 1 wk before experiment. Mino-strip was applied weekly on day 0 and 7. Clinical and microbiological test were performed on day 0, 7, 14, 28, 56. In R/P and Mino-strip applied group, Gingival index, GCF volume, probing depth and loss of attachment level were significantly reduced after the first weeks following treatment. In R/P and Mino-strip applied group, the relative proportions of spirochetes and motile rods were significantly reduced and the proportions of cocci and non motile rod were correspondingly increased for eight weeks following treatment. In R/P and Mino-strip treated group, total anaerobic and aerobic bacterial count were significantly decreased for the first two weeks following treatment and streptococcus count was decreased for eight weeks following treatment. In R/P and Mino-strip applied group, P. gingivalis, P. intermedius, B. forsythus, A. actinomycetemcomitans, F. nucleatum, E. corrodens, C. rectus counts were significantly reduced after the first week following treatment. According to this study, it is appeared that 30% Minocycline-loaded polycaprolacton film was effective in the treatment on rapidly progressive periodontitis.

• Asian Journal of Turfgrass Science
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• v.10 no.3
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• pp.213-230
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• 1996

A study of occurrence and distribution of cellular slime molds(CSMs) in forest soils of central areas of Korea was carried out. Samples for CSMs isolation were collected from 4 study sites; Mt.Kyeryong, Mt. Taebaek, Mt. Sobaek and Mt. Sokri. In Mt. Kyeryong, six species were found. These were Dictyostelium fasciculatum, D.firmibasis, D. mucoroides, D. minutum, D. brefeldianum and Polysphondylium pallidum. The average number of species isolated at one site was 0.75, and average density(clones /g soil) was 292. The results of soil sample analyses were that the concentration of Pb was higher than any other areas. In Mt. Taebaek, seven species were found; D. fasciculatum, D.firmibasis, D. mucoroides, D. miuutum, P.pallidum. P. violaceum, P. candidum. The average number of species isolated at one site was 2.3,and average density was 1,108. Based on importance values calculated from study sites within each of three elevation ranges, several of the more widely distributed and abundant species have distribution patterns that show a response to elevation. In Mt. Sobaek, eleven species were found. These were D. fasciculatum. D.firmibasis, D. mucoroides, D. miuutum, D. brefeldianum, D. crassicaule,D. deminutivum, D. implicatum, P. pallidum. P. violaceum and P. candidum. The average number of species isolated at one site was 3, and average density was 793. Species diversity appeared to be the highest in this area. In Mt. Sokri, six species were found. These were D. fasciculatum. D. mucoroides, D. minutum, D. purpureum, P. pallidum. and P. violaceum. The average number of species isolated at one site was 2.4 and average density was 858. It was noticeable that D.purpureum were much more comrnonly found in this pinus evergreen forest. Key words: Cellular slime molds(CSMs), Importance value, Elevation, Average number of species, Average density.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.439-448
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• 2007

The purpose of this study was to investigate the seasonal variations of sediment oxygen demand (SOD) in Lake Paldang and Lake Chungju of the Han River system and to suggest SOD values as parameters for the water quality prediction models of two lakes. SOD was measured at laboratory using sediment collected at 2 sites in Lake Paldang from June to November and at 4 sites in Lake Chungju from May to November in 2005, respectively. It was found from the laboratory test that the SOD in Lake Paldang ranged from 337.8 to 881.0 mg $O_2m^{-2}d^{-1}$ and in Lake Chungju ranged from 143.0 to 969.1 mg $O_2m^{-2}d^{-1}$. The SOD of Lake Paldang showed similar variations to the content of organic matter of sediment. The SOD of Lake Chungju was positively correlated with temperature (r=0.78, p<0.01), $PO_4-P(r=0.79,\;p<0.01)$, TP (r=0.55, p<0.05), DTP (r=0.55, p<0.05), $NO_3-N$ (r=(0.72, p<0.01) of hypolimnetic water. These results indicate that the SOD of Lake Paldang was affected by the content and origin of organic matter of sediment and the SOD of Lake Chungju was closely correlated with physical and chemical factors.