• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.106-112
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• 2015

Purpose: The long-term administration of antibiotics interferes with bacterial culture in the middle ear fluids (MEFs) of young children with otitis media with effusion (OME). The purpose of this study is to determine whether molecular diagnostics can be used for rapid and direct detection of the bacterial pathogen in culture-negative MEFs. Methods: The specificity and sensitivity of both polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) to the lytA gene of Streptococcus pneumoniae were comparatively tested and then applied for pneumococcal detection in the clinical MEFs. Results: The detection limit of the PCR assay was approximately $10^4$ colony forming units (CFU), whereas that of LAMP was less than 10 CFU for the detection of S. pneumoniae. Both PCR and LAMP did not amplify nucleic acid at over $10^6$ CFU of H. influenzae or M. catarrhalis, both of which were irrelevant bacterial species. Of 22 culture-negative MEFs from children with OME, LAMP positivity was found in twelve MEFs (54.5%, 12/22), only three of which were PCR-positive (25%, 3/12). Our results showed that the ability of LAMP to detect pneumococcal DNA is over four times higher than that of PCR (P<0.01). Conclusions: As a high-resolution tool able to detect nucleic acid levels equivalent to <10 CFU of S. pneumoniae in MEFs without any cross-reaction with other pathogens, lytA -specific LAMP may be applied for diagnosing pneumococcus infection in OME as well as evaluating the impact of a pneumococcal conjugate vaccine against OME.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.28-34
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• 2015

This study is to investigate microbiological hazards which can be used as fundamental data to adequately control leeks hazards and develop leeks GAP model for those who want to get GAP system. The microbiological investigations on cultivation environments (soil and water), crops (leeks), personal hygiene (workers' hands, clothes and gloves) and working tools (boxes) have been conducted for one year, so the period was classified under non-cultivation, cultivation, and post harvest. Total bacteria was detected from soil (4.0~6.7 log CFU/g), leeks (4.6~5.1 log CFU/g), hands (ND~3.3 log CFU/hand) and gloves ($ND{\sim}5.4\;log\;CFU/cm^2$) while nothing was detected from the other samples. The coliform contamination of leeks (4.8~5.0 log CFU/g) was more high than that of soil (3.9~4.2 log CFU/g). In case of foodborne pathogens, only B. cereus was detected at the level of 0.5~4.6 log CFU/g (or hand, $100cm^2$). Fungi was observed at the level of 2.1~3.8 log CFU/g (or hand, $100cm^2$) excepting water and some working tools. These results demonstrate that the contamination of leeks is comparatively higher than that of soil sample. The reason may be the cross-contamination by biological hazards presenting on soil. Therefore, it is necessary to properly control soil and fertilizer for safety against biological hazards.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.618-623
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• 2011

Escherichia coli O157:H7 has been considered as a significant food-borne pathogen since its role in causing hemorrhagic colitis and hemolytic uremic syndrome in humans was recognized. In this study, we developed an immunochromatography (ICG) assay for the detection of E. coli O157:H7. E. coli O157:H7 monoclonal antibody (EC MAb) and colloidal gold were conjugated and its specificity was determined by the ICG treated with EC MAb and antimouse IgG at test and control lines, respectively. The detection limit of the ICG was $1{\times}10^5$ CFU/mL, and no crossreactivity was observed to other E. coli strains and major food-borne pathogens. To determine the minimum enrichment time for the ICG, meats and sprouts were inoculated with $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7. After enrichment time of 10 and 2 h for meats and sprouts, respectively, up to $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7 could be detected by ICG.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.3
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• pp.302-307
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• 2002

To investigate difference of components changes in salt-fermented anchovy, Engaulis japonicus sauce during 18 months fermentation by tank size, various chemical properties were examined at 2$\~$3 months intervals. The contents of total and amino nitrogen, total ATP related compounds increased gradually during 18 months of fermentation, and showed higher content in salt-fermented anchor sauce produced by large tank scale (LTS) product than those of small tank scale (STS) product during fermentation. Hypoxanthine and uric acid were the most abundant in ATP related compounds, ranging from $81.1\%$ to $90.4\%$, The cross point of inosine (HxR) + hypoxanthine (Hx) and uric acid was faster in LTS with 10.3 months fermentation than in STS with 12.6 months fermentation. After 18month of fermentation, the LTS was rich in free amino acids, such as glutamic acid, alanine, aspartic acid, valine, Iysine in that order. On the other hand, the STS was rich in free amino acids, glutamic acid, aspartic acid, alanine, vsine, valine in that order. Absorbance at 453 nm were higher in STS than in STS, but was no difference the rate of increase during fermentation.

• Journal of Intelligence and Information Systems
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• v.17 no.3
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• pp.187-201
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• 2011

KOSPI200 index is the Korean stock price index consisting of actively traded 200 stocks in the Korean stock market. Its base value of 100 was set on January 3, 1990. The Korea Exchange (KRX) developed derivatives markets on the KOSPI200 index. KOSPI200 index futures market, introduced in 1996, has become one of the most actively traded indexes markets in the world. Traders can make profit by entering a long position on the KOSPI200 index futures contract if the KOSPI200 index will rise in the future. Likewise, they can make profit by entering a short position if the KOSPI200 index will decline in the future. Basically, KOSPI200 index futures trading is a short-term zero-sum game and therefore most futures traders are using technical indicators. Advanced traders make stable profits by using system trading technique, also known as algorithm trading. Algorithm trading uses computer programs for receiving real-time stock market data, analyzing stock price movements with various technical indicators and automatically entering trading orders such as timing, price or quantity of the order without any human intervention. Recent studies have shown the usefulness of artificial intelligent systems in forecasting stock prices or investment risk. KOSPI200 index data is numerical time-series data which is a sequence of data points measured at successive uniform time intervals such as minute, day, week or month. KOSPI200 index futures traders use technical analysis to find out some patterns on the time-series chart. Although there are many technical indicators, their results indicate the market states among bull, bear and flat. Most strategies based on technical analysis are divided into trend following strategy and non-trend following strategy. Both strategies decide the market states based on the patterns of the KOSPI200 index time-series data. This goes well with Markov model (MM). Everybody knows that the next price is upper or lower than the last price or similar to the last price, and knows that the next price is influenced by the last price. However, nobody knows the exact status of the next price whether it goes up or down or flat. So, hidden Markov model (HMM) is better fitted than MM. HMM is divided into discrete HMM (DHMM) and continuous HMM (CHMM). The only difference between DHMM and CHMM is in their representation of state probabilities. DHMM uses discrete probability density function and CHMM uses continuous probability density function such as Gaussian Mixture Model. KOSPI200 index values are real number and these follow a continuous probability density function, so CHMM is proper than DHMM for the KOSPI200 index. In this paper, we present an artificial intelligent trading system based on CHMM for the KOSPI200 index futures system traders. Traders have experienced on technical trading for the KOSPI200 index futures market ever since the introduction of the KOSPI200 index futures market. They have applied many strategies to make profit in trading the KOSPI200 index futures. Some strategies are based on technical indicators such as moving averages or stochastics, and others are based on candlestick patterns such as three outside up, three outside down, harami or doji star. We show a trading system of moving average cross strategy based on CHMM, and we compare it to a traditional algorithmic trading system. We set the parameter values of moving averages at common values used by market practitioners. Empirical results are presented to compare the simulation performance with the traditional algorithmic trading system using long-term daily KOSPI200 index data of more than 20 years. Our suggested trading system shows higher trading performance than naive system trading.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.52-61
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• 2009

The purpose of this study was to investigate the extent of excessive sugar, sodium, cholesterol, and saturated fat consumptions by elementary school students through processed food's intake. A survey study was conducted with 384 fourth and sixth grade students and their mothers from two schools in Seoul and Gyeonggi province. The data were analyzed for the frequency analysis, chi-square test and Pearson correlation using the SPSS/Windows (ver. 15.0). Results showed that students consumed high amounts of sugars through processed milk and carbonated beverages, and yogurt. Additionally, they had high sodium and saturated fat levels in their diet through Ramen. There was significant correlation (p<0.01) between mothers' purchasing and students' intake of processed food. Overall, both students and mothers had some knowledge on the impact of sodium on human health. About 50 percent of the respondents did not have accurate information about cholesterol, saturated fat, and trans fat. More than 50 percent of students and mothers had no nutritional education on the risk of excessive intake of sugar, sodium, cholesterol, saturated fat, and trans fat. Top twenty percent of the students had 39.7 g of sugar, 940.1 mg of sodium, 17.8 mg of cholesterol, and 11.2 g of saturated fat through processed foods per day on the average. These results suggest that execution of nutritional education about processed food is needed for high risk group of elementary school students and their mothers. Moreover, government must enact the regulation and policy for the food industry to reduce the risky nutrients from children's favorite processed food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1139-1147
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• 2013

The purpose of this study was to analyze the relationship between sanitary knowledge score and sanitary management performance among school foodservice employees. For this purpose, a paper-based questionnaire was developed and distributed to 300 school foodservice employees in Jinhae-gu, Changwon from May 13 to June 10 in 2009. A total of 276 responses were received and analyzed. The results of this study were as follows. The sanitary knowledge score of school foodservice employees was 16.60 (total score: 20). Their sanitary management performance level was 4.77 (based on a 5-point Likert scale). We found that sanitary management performance level of high sanitary knowledge score group was significantly higher than that of low sanitary knowledge score group (P<0.001). There was a significant positive correlation between sanitary knowledge score and sanitary management performance of school foodservice employees (P<0.01). Regression analysis showed that sanitary knowledge score of school foodservice employees had a positive effect on sanitary management performance (P<0.001). It implies that as school foodservice employees' sanitary knowledge increased, their sanitary management performance increased. In conclusion, to improve the sanitary quality of school foodservice, school foodservice employees' sanitary management performance level should be increased by improving their sanitary knowledge. So, a systematic and consistent sanitary education program should be conducted for school foodservice employees.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.257-265
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• 2005

Background : Rifabutin (ansamycin) is a spiro-piperidyl rifamycin, which is highly active against Mycobacterium tuberculosis. It has been found that some clinical isolates of tubercle bacilli that are resistant to rifampicin are susceptible to rifabutin, with some patients with multi-drug resistant pulmonary tuberculosis having shown favorable clinical and bacteriological responses to the rifabutin. This study was conducted to find the proportion of rifabutin-susceptible strains among rifampicin-resistant isolates from Korean MDR-TB patients, and investigate the presence of specific rpoB mutations, which may confer resistance to rifampicin, but not to rifabutin. Methods : 201 rifampicin-resistant and 50 pan-susceptible M. tuberculosis isolates were randomly selected for this study. The isolates were retested at rifampicin and rifabutin concentrations of 0, 20, 40 and $80{\mu}g/ml$, respectively. The isolates that grew at and/or over a rifabutin concentration of $20{\mu}g/ml$ were judged rifabutin-resistant. The rpoB gene was extracted from the isolates, and then amplified for direct sequencing to investigate specific rpoB mutations that conferred rifabutin- susceptibility but rifampicin-resistance. Results : Out of the 201 rifampicin-resistant M. tuberculosis, 41 strains (20.4%) were susceptible to rifabutin using the absolute concentration method on Lowenstein-Jensen media. The rpoB mutation types that showed susceptibility to rifabutin were Leu511Pro, Ser512Arg, Gln513Glu, Asp516Ala, Asp516Gly, Asp516Val, Asp516Tyr, Ser522Leu, His526Asn, His526Leu, His526Cys, Arg529Pro and Leu533Pro. A reverse hybridization technique was able to detect 92.5% of the rifabutin-susceptible isolates, with a specificity of 96.1% among 195 M. tuberculosis isolates with the rpoB mutation. Conclusions : Around 20% of the rifampicin-resistant isolates in Korea showed susceptibility to rifabutin, which was associated with some specific mutations of rpoB. Rifabutin could be used for the treatment of MDR-TB patients, especially when drug susceptibility testing reveals susceptibility to rifabutin.

• Pediatric Infection and Vaccine
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• v.20 no.3
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• pp.131-138
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• 2013

Purpose: This study aimed to study the antibody response of Japanese encephalitis vaccination in children using different kinds of vaccines (inactivated vaccine, live attenuated vaccine or interchanged) and evaluate the effectiveness of the vaccines to provide the basis of efficient immunization schedule of Japanese encephalitis. Methods: Measurement of the neutralization antibody (NTAb) titers following Japanese encephalitis vaccination using different vaccines for 170 children, 2-6 year of age, who visited six university hospitals and are confirmed by immunization records. Results: Among 170 children who were given primary immunization on Japanese encephalitis, 103 children were given inactivated vaccine, 64 children were given live attenuated vaccine and 3 children were given interchangeably. NTAb titers were more than 1:10 in all children of three groups. The geographic mean antibody titer was 322 in inactivated vaccine group and 266 in live attenuated vaccine group. However, there was no significant difference between two groups. In both groups, the NTAb titer showed the peak at 1-4 months after the third immunization and declined. The NTAb titers of three children who were given two kinds of vaccines alternately were 1:135, 1:632, and 1:2511, respectively. Conclusion: According to the results of this study in children younger than 6 years old, there is no significant difference in effectiveness between inactivated and live attenuated vaccines. However, further studies for the changes of antibody titers for a longer period of time on larger population are required.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.181-194
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• 2002

Parasitism is a one-sided relationship between two organisms in which one benefits at the expense of the other. Parasitic dinoflagellates, particularly species of Amoebophrya, have long been thought to be a potential biological agent for controlling harmful algal bloom(HAB). Amoebophrya infections have been reported for over 40 species representing more than 24 dinoflagellate genera including a few toxic species. Parasitic dinoflagellates Amoebophrya spp. have a relatively simple life cycle consisting of an infective dispersal stage (dinospore), an intracellular growth stage(trophont), and an extracellular reproductive stage(vermiform). Biology of dinospores such as infectivity, survival, and ability to successfully infect host cells differs among dinoflagellate host-parasite systems. There are growing reports that Amoebophrya spp.(previously, collectively known as Amoebophrya ceratii) exhibit the strong host specificity and would be a species complex composed of several host-specific taxa, based on the marked differences in host-parasite biology, cross infection, and molecular genetic data. Dinoflagellates become reproductively incompetent and are eventually killed by the parasite once infected. During the infection cycle of the parasite, the infected host exhibits ecophysiologically different patterns from those of uninfected host in various ways. Photosynthetic performance in autotrophic dinoflagellates can be significantly altered following infection by parasitic dinoflagellate Amoebophrya, with the magnitude of the effects over the infection cycle of the parasite depending on the site of infection. Parasitism by the parasitic dinoflagellate Amoebophrya could have significant impacts on host behavior such as diel vertical migration. Parasitic dinoflagellates may not only stimulate rapid cycling of dissolved organic materials and/or trace metals but also would repackage the relatively large sized host biomass into a number of smaller dinospores, thereby leading to better retention of host's material and energy within the microbial loop. To better understand the roles of parasites in plankton ecology and harmful algal dynamics, further research on a variety of dinoflagellate host-parasite systems is needed.