• The Korean Journal of Malacology
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• v.28 no.3
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• pp.197-213
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• 2012

This study was performed to know the community structure of macrobenthos and environmental factors at each 16 stations in the subtidal sandy bottoms of the southern coastal water of Jeju Island from July to November, 2011. Mean temperature and mean salinity were $20.2-22.7^{\circ}C$, 33.7-34.9 psu which shows stable water messes. Chlorophyll a concentrations of phytoplankton ranged from 0.71 to 1.71 mg/L (1.11 mg/L), showing higher July than September and November with a blooming in summer. The mean concentration values (the ranges in parentheses) of nitrate, phosphate, and silicate are 0.029-0.206 mg/L (0.101 mg/L), 0.001-0.027 mg/L (0.007 mg/L), 0.024-0.682 mg/L (0.454 mg/L), respectively. However, the values higher coastal zone due to influxes from the land. A total of 37 species was identified. of these mollusca comprised 29 secies (78.4%); Echinodermata 5 (13.5%); Arthropoda 3 (8.1%). density and biomass were estimated to be 550 ind./$m^2$ and 20,951.8 gwwt/$m^2$, respectively. Mollusca were the most dominant faunal group in terms of abundance (481 ind./$m^2$) and number of species as well, whereas bivalves were predominant in biomass (16,647.6 gwwt/$m^2$). The dominant species were Vasticardium burchardi, Oblimopa japonica, Mactar achatina, Bornatemishistrioiw akawai, Paphia vernicosa, Amusium japonicum, Glycymeris albolineata, Astriclypeus manni in 15-30 m. The seasonal variation appeared as distinct, Mollusca of individual and biomass. When summer was make a slow increase, after the highest decrease in autumn. The abundance of macrobenthic invertebrates showed significant correlation with environmental factors (Chlorophyll a, DIN, $SiO_2$, Fine sand, Very fine sand) in almost all sampling depths. The biodiversity, evenness richness index were appeared 1.56-2.50 (H'), 0.49-0.80 (E'), 4.12-4.67 (R) in each stations. The dominace index were appeared Highest in November and lowest in September.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.150-159
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• 2008

Purpose: To assess the relationship between lifestyle and metabolic syndrome in obese children and adolescents. Methods: We retrospectively reviewed the medical records and laboratory results of 109 subjects (7~15 years of age) who visited our pediatric obesity clinic between January 2004 and December 2007. They completed the parent- and self-report questionnaire developed by the Committee on Nutrition of the Korean Pediatric Society to assess lifestyle. The metabolic syndrome was defined as having 3 or more of the following metabolic risk factors: obesity, hypertension, serum triglycerides ${\geq}$110 mg/dL, HDL-cholesterol ${\leq}$40 mg/dL, fasting glucose ${\geq}$110 mg/dL, and insulin ${\geq}20{\mu}IU/mL$. Results: All subjects had at least 1 risk factor (obesity). Sixty-three percent of subjects had 2 or more risk factors, 32% of subjects had 3 or more risk factors, and 10% had 4 or more metabolic risk factors. Hypertriglyceridemia (36%), hypertension (32%), hyperinsulinemia (24%), and HDL-hypocholesterolemia (20%) were observed. Fasting blood glucose levels were normal in all subjects. Hypertension was significantly associated with an unbalanced diet and hyperinsulinemia was significantly associated with parental obesity (p<0.05). Those who ate after 8 PM were at a risk of hypertension (odds ratio, 2.5; 95% CI, 1.0~6.1). Those who did not have a preference for exercise were at a risk of hyperinsulinemia (odds ratio, 10.4; 95% CI, 2~54.1). Those who watched TV for ${\geq}$3 hours/day were at a risk of metabolic syndrome (odds ratio, 4.8; 95% CI, 1.2∼18.8). Conclusion: Lifestyle, such as eating late, no preference for exercise, and TV watching ${\geq}$3 hours/day, were related to metabolic syndrome in obese children and adolescents.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.40-53
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• 2013

Most of the existing domestic studies to identify the distribution of longevity population and influencing factors oriented confirmatory approach. Furthermore, most of the studies in this research topic simply have used their own definition of spatial unit of analysis or employed arbitrary spatial units of analysis according to data availability. These research approaches can not sufficiently reflect the spatial characteristic of longevity phenomenon and exposed to the Modifiable Aerial Unit Problem(MAUP). This research performed the Exploratory Spatial Data Analysis(ESDA) to identify the spatial autocorrelation of the distribution of longevity population and investigated whether the modifiable areal unit problem in the aspect of scale effect using spatial population data in Korea. We used Si_Gun_Gu and Eup_Myeon_Dong as two different spatial units of regional longevity indicators measured. Then, we applied Getis-Ord Gi* to investigate the existence of spatial hot spots and cold spots. The results from our analysis show that there exist statistically significant spatial autocorrelation and spatial hot spots and cold spots of regional longevity at both Si_Gun_Gu and Eup_Myeon_Dong levels. This result implies that the modifiable areal unit problem does exist in the studies of spatial patterns of longevity population distribution. The demand for longevity researches would be increased inevitably. In addition, there were apparent differences for the global spatial autocorrelation and local spatial cluster which calculated different spatial units such as Si_Gun_Gu and Eup_Myeon_Dong and this can be seen as scale effect of MAUP. The findings from our analysis show that any study in this topic can mislead results when the modifiable areal unit problem and spatial autocorrelation are not explicitly considered.

• Journal of Animal Science and Technology
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• v.55 no.3
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• pp.185-194
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• 2013

Microsatellite markers have been a useful genetic tool in determining diversity, relationships and individual discrimination studies of livestock. The level of genetic diversity, relationships among two Korean indigenous chicken brand populations (Woorimatdag: WR, Hanhyup3: HH) as well as two pure populations (White Leghorn: WL, Rhode Island Red: RIR) were analyzed, based on 26 MS markers. A total of 191 distinct alleles were observed across the four chicken populations, and 47 (24.6%) of these alleles were unique to only one population. The mean $H_{Exp}$ and PIC were estimated as 0.667 and 0.630. Nei's $D_A$ genetic distance and factorial correspondence analysis (FCA) showed that the four populations represented four distinct groups. However, the genetic distance between each Korean indigenous chicken brand (WR, HH) and the pure population (WL, RIR) were threefold that among the WR and HH. For the STRUCTURE analyses, the most appropriate number of clusters for modeling the data was determined to be three. The expected probabilities of identity among genotypes of random individuals (PI) were calculated as $1.17{\times}10^{-49}$ (All 26 markers) and $1.14{\times}10^{-15}$, $7.33{\times}10^{-20}$ (9, 12 with the highest PI value, respectively). The results indicated that the brand chicken breed traceability system employing the own highest PI value 9 to 12 markers, and might be applicable to individual identification of Korean indigenous chicken brand.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.288-297
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• 2010

This study was to evaluate the ecological stream health through the Multimetric Fish Assessment Index (MFAI) along with fish fauna analysis based on the tolerance and trophic guilds at Miho stream in 2008 and 2009. Also, we analysed total mercury concentration in fish tissues to examine heavy metal contamination. Total sampled fish were 40 species and 2,557 individuals and Zacco platypus was the most dominant with 35% relative abundance. It was sampled with 11.4% RA for Korean endemic species (10 species 291 individuals) less than average RA 39.3% for the Geum river watersheds. According to the tolarance guild analysis, tolerant species was more dominant with 58.9% RA (15 species, 1,507 individuals) than sensitive species with 6.6% RA. Trophic guild analysis also suggested that omnivores were more dominant (60.5% RA) than insectivores (31.5% RA). Riffle-benthic species was also sampled with 7.7% RA. Ecological stream health based on the MFAI were averaged 25.3 (n=3) with fair-poor condition in 2008 and also 26.3 (n=3) with fair condition in 2009, just slightly increased than 2008. Qualitative habitat evaluation index was averaged 134 (n=3) with fair condition but most of sites had sediment accumulation that reflected substrate degradations proceeding. From the result of total mercury accumulation in fish tissues, kidney and liver tissues showed the highest but the lowest for gill tissues. Overall mercury concentration were not exceed the national standards by Korean Federation of Drug and Administration (KFDA). Consequently, our result could correspond with the characteristics of Miho stream where point sources such industrial complexes and wastewater treatment plant widely distributed around the stream along the gradient of up and downstream.

• Korean Journal of Environment and Ecology
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• v.31 no.5
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• pp.444-454
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• 2017

There are many ongoing studies of infectious diseases as the major factor responsible for global declining of the amphibian population. Although some point out the amphibian rearing facilities like frog farms as one of the important sources of harboring and spreading amphibian infectious pathogens in the wild, there have been few related studies in South Korea. In this study, we investigated the bacterial and fungal colonies on the skin and in the internal organs of frogs and tadpoles collected inside and outside of Dybowski's brown frog farms in Inje, Goesan, and Gongju to compare the difference according to the region and between inside and outside the farm. We also intended to classify the bacteria collected from the tadpoles into species by analyzing 16s rDNA gene sequences. The result showed that the number of bacterial colonies found in the skin and gut of frogs and the number of fungal colonies found in the skin and liver of frogs collected in Goesan was significantly greater than those in the frogs in Inje. However, there was no difference between the frogs collected inside and outside of farms in both regions. In the case of tadpoles, the number of fungal colonies in the tadpoles collected from Gongju was greater than that in the tadpoles collected from Inje. The comparison of inside and outside frog farms showed that there were more bacterial colonies on the skin of the tadpoles collected from inside than outside the frog farm in Inje and more bacterial colonies in the organs of the tadpoles collected from outside than inside the farm in Gongju. The frogs with higher condition factor (body weight/snout-vent length*100) showed fewer bacterial colonies on the skin and fewer fungal colonies in the heart, but there were no significant relationships in tadpoles. We identified the total of 15 genera and four phyla of bacteria, but the difference according to regions and between inside and outside farm was not evident. The result of this study indicates that the different conditions according to the locality of farm and between inside and outside farm cause the difference in the population sizes of bacterial and fungal colonies and that it can affect the overall health condition of Dybowski's brown frogs in the farm. Moreover, the result suggests that effective disease control in the facility is greatly necessary to ensure successful operation of amphibian rearing facility and to prevent the possible spread of diseases from the facility to the wild.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.197-206
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• 2007

This study was conducted to survey the population of water birds wintering at the seven coastal wetlands of Jeollanam province including Suncheon Bay and Yeongsan Lake, from 2000 through 2003. The 90 species and 857,570 individuals in total were sighted at the seven survey sites. We classified the wintering water birds into seventeen groups of taxa based on the similar ecological attributes, among which, eight groups were found to inhabit the water surface or riparian areas. Classified groups that showed higher rate of using bay areas than that of lake areas were in the order of waders, gulls and swans. On the other hand, the groups that showed higher rate of using lake areas than that of using bay areas were revealed in the order of dabbling ducks, grebes and geese. In conclusion, there was a difference in the pattern between the two classified groups. As a result of the UPGMA cluster analysis using CCs ($S{\varnothing}rensen'a$ index of similarity and Ro (Horn's index of community overlap), the results showed that Suncheon Bay had the most unique species formation out of the seven areas. Bay and lake areas were different from each other in the formation of species and Individuals. As a result of combining the index rank according to the maximum aggregate count, the Suncheon Bay is ranked the highest in importance of the habitats for water birds, followed by the order of Boseong-Deukryang Bay, Gangjin Bay, Gocehongam Lake, Geumho Lake, Yeomam Lake, and Yeongsan Lake. Considered overall, the importance of the bay areas was relatively higher than that of reclaimed lake areas.

• Journal of Wetlands Research
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• v.1 no.1
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• pp.29-44
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• 1999

Vegetation structure and distribution of the vascular hydrophytes and hygrophytes, and the growth pattern, standing crop and amounts of nutrient uptake by Salix species were investigated in the upper stream wetlands of the Namgang-Dam, Chinju-city, Gyeongsangnam-do, Korea from April to November in 1997. The flora was composed of 43 hydrophytes and 241 hygrophytes, or total 284 vascular plants. The life forms of the hydrophytes were classified as 27 kinds of emergent plants, 4 floating-leaved plants, 3 free-floating plants, and 9 submersed plants. In the herb layer, the dominant species was Persicaria hyciropiper, and the ranges of the species diversity indices (H'), equitabilities, (J') and community similarity indices (CCs) were 1.59~1.89, 0.87~0.96, and 0.35~0.83, respectively. In the shrub and subtree layers, 17 kinds of Salix species were supposed to the pioneer plants at the early stage of the succession. The number of branches per main stem of Salix species was 5.0. The DBH class-frequency histograms of Salix species were the reverse J type, and the natural regeneration of the Salix community was expected. Basal area of Salix species per square meter was $24.87cm^2$. Volume of Salix species per square meter was $12,008cm^3$ and total phytomass of the Salix species was estimated as 12,894 ton. Biomass distribution of Salix species in the stem, the branch and twig, and the leaf was 64.1%, 28.1%, and 7.8%, respectively. The amounts of nitrogen and phosphorus absorbed by Salix species were 68,022 and 19,823 kg. It was recommended that application and conservation of the wetland and other counterplans are indispensable to reduce the adverse effects of water pollution and to preserve the wetland ecosystem.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.152-159
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• 2002

The seasonal variations of nitrifying bacterial population sampled from 3 sites in Moon-Chon reservoir were analyzed by in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes from August 2000 until July 2001. In addition, physico-chemical parameters such as temperature, pH, chi-a and DOC were measured to determine correlations between those factors and the size of nitrifying bacterial populations. Total bacterial numbers varied in the range of $0.8{\sim}1.5{\times}10^6\;cells/ml$ independent of sites and had the maximal values in March at all 3 stations. The ratio of eubacteria to total bacteria ranged from 44.9% to 79.5%, and the ratio of each nitrifying bacteria to eubacterial numbers reached only $1.0{\sim}7.4%$. The variations of ammonia-oxidizing bacteria ranged from $1.1{\times}10^4$ to $3.0{\times}10^4\;cells/ml$ without noticeable peak values whereas those of nitrite-oxidizing bacteria varied in $1.3{\sim}5.7{\times}10^4\;cells/ml$ with the increasing tendency in winter regardless of the sites. Moreover it was observed that the numbers of nitrite-oxidizing bacteria were higher than those of ammonia-oxidizing bacteria. Total bacterial numbers correlated with water temperature (r = 0.355, p<0.05) and DOC (r = 0.58G, p<0.01) positively whereas nitrite-oxidizing bacteria correlated with temperature (r = -0.416, p<0.05) and pH (r = -0.568, p = 0.001) negatively. In addition, DOC represented good correlations with eubacterial numbers (r = 0.448, p<0.01). These results indicate that temperature, DOC and pH might be one of the main factors affecting variations of bacterial populations in the aquatic ecosystem. It was also suggested that FISH method is a useful tool for detection of slow growing nitrifying bacteria.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1040-1046
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• 2010

This research is composed of a series of survey of existing plants species by classifying biotope type of agro-ecosystem of Guksoo village area of Yangpyeong County, to collect and analyze basic data of vegetation analysis for indicators development of agro-ecosystem habitat quality. From the observation area, we found total 141 kinds of tracheophytes (53 Family 114 Genus 124 Species 16 Variety 1 Breed) and they are 3.36% of total Korean tracheophytes (4,191 kinds). Among those 141 tracheophytes, there are 23 kinds of naturalized plants (11 Family 20 Genus 20 Species 2 Variety) and they are 8.61% of total Korean naturalized plants (267 kinds). Among those 141 tracheophytes, they include 0.71% of pteridophyte, 0.71% of gymnosperm, 98.58% of angiosperm. So, most of them are angiosperm. When we classify them according to plant life form characteristics, dormant/diapause type plants include 45 species (31.91%) of annual plant (Th), 19 species (13.48%) of Th (w), 17species (12.06%) of hemicryptophyte (H). Regarding propagation type, as for the Radicoid form, there are 99 species (70.21%) of crumb structure plant, 13 species (9.22%) of $R_4$, 12 species (8.51%) of $R_{2.3}$ are the crumb structure does not make any connection on the ground or under ground. As for the Disseminule form of propagation type, there are 62 species (43.97%) of Gravity dispersal type $D_4$), 23 species (16.31%) of Wind dispersal type ($D_1$), 21 species (14.89%) of $D_{1.4}$. According to this survey of plant distribution rate by plant life form characteristics, we may acquire many knowledge about species composition of sociability, cluster's reaction against environmental elements, space usage and possible species competition in community. It may be very useful basic data for habitat preservation to keep and promote biological diversity.