• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.121-134
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• 2015

Spatial and temporal changes in algal population in Yongdam reservoir and ecological factors that induced the changes in the size and composition of algal population were investigated by monthly sampling at ten locations in the reservoir. Nutritional state of the reservoir was identified to be phosphorus-limited with nitrogen to phosphorus (N : P) ratio much greater than 17 in most samples. Algal population was dominated by three taxonomic groups, diatoms, chlorophytes and cyanobacteria. Although explosive algal growth was not observed in the summer, algal population showed transition with time of the dominant algal type from diatoms in the winter to cyanobacteria in the summer. Chlorophyta was not the dominant group in the reservoir although they maintained relatively stable number of cells in the reservoir and showed increase in population from March to May. The application of statistical methods revealed that the factors inducing changes in cell number of each group were water temperature for diatoms and cyanobacteria and phosphorus concentration for chlorophyte. Fluctuation of cyanobacterial population was mainly observed near the inlet of tributaries while diatoms showed higher variation inside the reservoir.

• Ocean Science Journal
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• v.41 no.4
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• pp.211-219
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• 2006

A comparison was made of population of the economically important cockle Anadara (=Scapharca) broughtoni (Bivalvia, Arcidae) inhabiting different areas of the Razdolnaya River estuary at the head of Amurskii Bay (Peter the Great Gulf, East Sea). Also, changes in cockle population density and structure, as well as in cockle growth rates during the last 20 years were studied. In all years of investigation, the morphometrical parameters and growth rates of cockles were smaller at the sites located close to the River mouth than farther down-estuary. The differences can be attributed to higher concentration of suspended particulate matter, decreased salinity and water temperature, as well as a longer exposure to these unfavorable environmental factors at sites located close to the River mouth, compared to farther sites. For two decades, cockle population density had decreased by almost 30 times at some sites in the River estuary. The main reason for this population decline is commercial over-fishing of the cockle. Besides, for the last 20 years, linear parameters of the cockles in the population decreased approximately by 30% and weight parameters, almost two times. Cockle growth rates also decreased for this period. Evidently, these facts are due to the damaging effect of dredging.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.63-68
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• 2002

The purpose of this study was to estimate the population pharmacokinetics of clarithromycin in healthy adult Korean and to investigate the factors influencing the pharmacokinetics of clarithromycin. The population pharmacokinetic parameters of clarithromycin were calculated with the data from healthy adult Koreans. A total of 798 plasma concentrations obtained from 78 subjects after administration of a single oral dose of 250 mg or 500 mg were used for the modeling. The concentration-time data were fitted to a one-compartment open model assuming a first-order absorption and elimination with no lag time. The correlations between various factors [such as sex, age, height, weight, sect creatinine (Scr) and dose and pharmacokinetic parameters were estimated with stepwise linear recession analyses. The selected covariates were incorporated in the population model of NONMEM, and the importance of each covariate was investigated by means of backwards elimination. The apparent clearance (CL/F) was significantly correlated to Scr and sex, and the apparent volume of distribution (Vd/F) was significantly correlated to Scr and height in a nonlinear relationship. The population values of Ka was 1.8 h $r_{-1}$, CL/F was 37.71 L/hr, Vd/F was 200 L and t/ sub 1/2 / was 3.68 hrs for a male Korean with 170 m height and 1.0 mg/dL Scr.

• Journal of the Korean housing association
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• v.25 no.3
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• pp.35-43
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• 2014

Korea is the most rapidly aging country in the OECD countries, becoming 'an aging society' in 2010, when over 12% of the population had reached the age 65 and beyond. Along with the population aging, problems of the elderly have become a social issue. Also, the elderly population in most farming villages is increasing due to the cityward concentration of younger generation and the rapid urbanization centered around the capital area. Yet no definite success in revitalization of these villages has been reported despite the acknowledgement of the problems arising from such phenomena. Therefore, by examining "marginal villages" (communities whose joint social activities are difficult to maintain as over 50% of the population is 65 years or older) in Japan, which at this point has entered "the ultra-aged society" before Korea, this study intends to compare and analyze the countermeasure plans for the population decrease in these villages. The case study has been done with the focus on the literary references published in Japan such as papers, various reports, statistics, newspapers, and journals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1120-1126
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• 2000

Recently, in order to analyze the time series problems that occur in the nature word, and analyzing method using a neural electric network is being studied more than a typical statistical analysis method. A neural electric network has a generalization performance that is possible to estimate and analyze about non-learning data through the learning of a population. In this paper, after collecting weather datum that was collected from 1987 to 1996 and learning a population established, it suggests the weather forecasting system for an estimation and analysis the future weather. The suggested weather forecasting system uses 28*30*1 neural network structure, raises the total learning numbers and accuracy letting the selecting concentration learning about the pattern, that is not collected, using the descending epsilon learning method. Also, the weather forecasting system, that is suggested through a comparative experiment of the typical time series analysis method shows more superior than the existing statistical analysis method in the part of future estimation capacity.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.41-46
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• 1997

Diet is generally accepted as one of the important factors in human cancer development. Ethyl carbamate has been associated with cancer for several decades and mainly found in the fermented beverages and foodstuff. The relationship between ethyl carbamate and the human health cannot be ignored especially in the areas where fermented foods consists of regular food consumption. To investigate the ethyl carbamate exposure level in Korean population, commercial fermented food samples were collected form local markets I Seoul area and home-made varieties were collected throughout the country. Following partial purification the concentration of ethyl carbamete was determined by GC/ MS. The concentration of ethyl carbamate ranged to 70 ppb in soysauce, to 10 ppb in soybean paste, and to 5 ppb in vinegars. Korean traditional alcoholic beverages showed small amount of ethyl carbamate. The estimated daily exposure of Korean population was 0~1900ng/day. It would be prudent to put efforts to minimize the formation of ethyl carbamate since the risk from the higher range exposure cannot be ignored.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.97-103
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• 1996

This study was performed to investigate the effects of lipid on cellular senescence, lipid peroxide production, and morphological changes. For this study we used primary skin fibroblasts from neonate rats grown in media various lipid contents. Fibroblasts were cultured until they lost their proliferation potential either in control medium (Dulbecco's modified Eagle's medium supplement with 10% fetal bovine serum) or in media supplemented with various concentrations of lipid-cholesterol rice component from bovine serum. Cumulative population doublings(CPD, as an index of cellular life span), and cellular thiobarbituric acid reactive substances (TBARS, as an index of lipid peroxide) concentrations were measured and morphological changes were observed. CPD were shortened with increasing lipid concentration in media ; 28.12 for cells grown in control medium and 13.42, 11.42, and 6.19 for those grown in 0.1%, 1% and 5% lipid rich components containing media, respectively. Cellular proliferation ratios were those grown in 5% lipid rich components containing media were delayed and they were degenerated soon. TBARS concentrations were increased with increasing concentration of lipid in media. Morphological changes were observed in cells grown in control medium by cellular senescence. Especially lipid droplets were observed in cells grown in 5% lipid rich components containing media. Therefore it seems that lipid contents in media had an effect on cellular proliferation and cellular life span, possibly via lipid peroxide production.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.677-687
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• 2017

Caffeine has a long history of human consumption but the consumption of caffeine due to caffeinated energy drinks(CEDs) is rapidly growing. Marketing targets of CED sales are children, adolescents and young adults, possibly caffeine-sensitive groups and its effect for them can be significantly different from healthy adults. Caffeine-related toxicities among these groups are growing in number and a number of countries are recognizing severity of caffeine toxicities. Previous research showed prediction of maximal plasma caffeine concentration profiles after the single CED ingestion and the primary aim of this study is to visually predict plasma caffeine concentration after the single and multiple ingestion of standard servings of CED. Based on the population pharmacokinetic model using Monte Carlo simulation, prediction of caffeine concentration leading to caffeine intoxication in the sensitive groups is quantitatively presented and visualized. This research also broadens the perspective by creating and utilizing diverse open science tools including R package, Edison Science App and Shiny apps.

• Nutrition Research and Practice
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• v.10 no.2
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• pp.206-211
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• 2016

BACKGROUND/OBJECTIVES: Obesity, which is a known risk factor for many chronic diseases, has also been associated with vitamin D deficiency. This study explored the relationship between serum 25-hydroxy-vitamin D [25(OH)D] concentrations and adiposity measures in a general Korean population using the most recent, nationally representative survey data. SUBJECTS/METHODS: The study sample consisted of 4,771 Korean adults (${\geq}19years$) who participated in the fifth Korean National Health and Nutrition Examination Surveys. Serum 25(OH)D was determined by radioimmunoassay. Body mass index (BMI), waist circumference (WC) and total body fat content were measured as adiposity measurements. Total body fat content was measured by dual-energy X-ray absorptiometry. RESULTS: The serum 25(OH)D level was significantly higher in men than in women. Serum 25(OH)D concentration was positively correlated with energy intake, and it was negatively correlated with total body fat content (P < 0.0001) and percentage body fat (P < 0.0001) after adjustment for age in both sexes, while was inversely correlated with BMI only in women. In multivariable regression analysis, serum 25(OH)D was inversely associated with the total body fat content after adjustment for age, BMI, education, region, smoking, alcohol consumption, physical activity, and energy intake only in men (P = 0.0047). However, the serum 25(OH)D concentration was not associated with WC or BMI, indicators of adiposity after adjustment for potential risk factors. CONCLUSIONS: Serum 25(OH)D concentration was independently associated with the total body fat content in a general Korean population, but it may be not associated with the indicators for estimating adiposity, such as WC or BMI.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.418-429
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• 2019

This study was conducted to evaluate the antioxidant and antimicrobial activities of lyophilized extracts of scallions (Allium fistulosum L., SLE), garlic (Allium sativum, GLE), and gold kiwi (Actinidia chinensis, GKE) and their effects on the quality of chicken breast meat inoculated with L. monocytogenes during storage for 9 days at $4^{\circ}C$. The lowest minimum inhibitory concentration and minimum bactericidal concentration (25 and 100 mg/mL, respectively) against L. monocytogenes were observed for SLE and GLE, respectively. GKE had the lowest half-maximal inhibitory concentration ($IC_{50}$) for 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity (5.06 mg/mL). The pH values of meat inoculated with L. monocytogenes and dipped in 1% SLE (LSLE), 1% GLE (LGLE), or 1% GKE (LGKE) were lower than that of the control on day 3 of storage (p<0.05). The initial population of L. monocytogenes in meat was 4.95-5.01 Log CFU/g. However, the population in the LSLE (5.73 Log CFU/g) was lower than that in the control (6.23 Log CFU/g) on day 5 (p<0.05). The volatile basic nitrogen value of the LSLE (19.90 mg/100 g) was lower than that of the control (24.38 mg/100 g) on day 7 (p<0.05). Moreover, treatment with SLE resulted in the maintenance of meat quality and reduced the population of L. monocytogenes on the meat. Thus, SLE may be used as an alternative natural and environmentally friendly sanitizer for reducing L. monocytogenes contamination in the chicken meat industry.