• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.157-168
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• 2020

The sensitivity of forest soil to acidification in the Republic of Korea (ROK) was evaluated based on pH_H2O, cation exchange capacity (CEC), and base saturation (BS). Sensitivity to acidification was categorized into three grades: adequate level (AL, pH ≧ 4.2, CEC ≧ 15cmol/kg, BS ≧ 15%), caution level (CL, at least one indicator is below AL), and severe Level (SL, all three indicators are below AL). Soil samples were collected from the 65 stationary monitoring plots (40 × 40 ㎢), distributed throughout ROK. Only 19% of soil samples were classified as AL, while 66% and 15% were CL and SL, respectively. The median of pH_H2O, CEC, BS, and Ca/Al indicator in AL soils was pH 4.64, 20.7cmol/kg, 29%, and 6.3, respectively. Moreover, BC_ex (K⁺, Mg²⁺, Ca²⁺) and available phosphorus (AP) concentration compared with a threshold value and molar ratio of BC_ex and AP to total nitrogen (TN) was high. This indicates that AL soils have a good nutrient condition. The molar Ca/Al ratio, an indicator for toxicity of exchangeable aluminum (Al_ex), was more than 1, indicating no negative impact of Al_ex on plant growth. On the contrary, the median of pH_H2O, CEC, and BS in SL soils was pH 4.02, 13.2cmol/kg, and 10%, respectively. The Ca/Al index was less than 0.6, which indicates that negative impacts of Al_ex on plants were high. Furthermore, both the concentration of BC_ex in SL soils and the BC_ex/TN ratio were the lowest among the three acidity degrees. This shows that SLsoils can be degraded by soil acidification compared with less acidic soils.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1497-1507
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• 2016

The purpose of this study was to conduct importance and performance analysis of sanitation management in workers at small and medium foodservice industries using HACCP prerequisites. Questionnaires were distributed to 500 small and medium foodservice industry workers in Seoul Gyeonggi province, and a total of 458 responses were used for analysis. Factors with relatively low comparison degree were as follows. 'Handwashing and clean uniform of employee in the workplace', 'regular checking and managing of trapped vermin and rodents', 'checking stocked raw materials', 'recording and filing the results of improved food safety factors', and 'regular cleaning and sterilizing of monitoring tools' factors must be improved along with their performance levels through sanitation education. According to the IPA results, among the 15 HACCP prerequisite factors with high importance but low performance were '2. Regular checking and managing of trapped vermin and rodents', '4. Handwashing and clean uniform of employee in the workplace', '14. Preventing food cross-contamination'. Furthermore, the small and medium foodservice industry IPA with high importance but low performance were 'Regular checking and managing of trapped vermin and rodents', 'Handwashing and clean uniform of employee in the workplace', and 'Preventing food cross-contamination' for the small foodservice industry, along with 'Vermin and rodents control' and 'Recording and filing the results of improved food safety factors' for the medium foodservice industry. Thus, there is a need for reinforced hygiene education through case studies on actual food service establishments to fulfill sanitation guidelines and set amended guides for much-needed items for small and mid-sized food service.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.58-64
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• 2011

The purpose of this study was to analyze the content and consumption of total sugar from school lunches at Incheon and Chuncheon. The samples were collected from eight elementary schools and eight middle schools in Incheon and Chuncheon for 15 days. The analysis of total sugar content was performed for 1334 main dishes, side dishes, and desserts, which were supplied by elementary and middle school foodservices. Total sugar content was extracted from various types of food with 50% ethanol after defatting. We simultaneously analyzed sugars such as fructose, glucose, sucrose, maltose, and lactose by a high performance liquid chromatography with refractive index detector. The average lunch intake for elementary school and middle school students was $372.6{\pm}72.2g$ and $449.2{\pm}81.1g$, respectively. The total sugar content in desserts was $7.21{\pm}6.32g/100g$, $1.69{\pm}2.44g/100g$ in side dishes, and $0.32{\pm}0.77g/100g$ in main dishes. Among side dishes, fried foods, stir-fried foods, and sauces contained the highest amounts of total sugar. The total sugar intake was $4.63{\pm}5.11g$ in desserts, $0.64{\pm}1.01g$ in side dishes, and $0.55{\pm}1.48g$ in main dishes. Main and side dishes with a high total sugar intake included cooked rice with seasoning, fried foods, stir-fried foods, and preserved foods. The average total sugar intake per meal for elementary school, middle school, and all students was $4.03{\pm}3.67g$, $6.97{\pm}6.59g$, and $5.50{\pm}5.53g$, respectively. We have provided useful information to decrease the intake of total sugar in school lunches. It is recommended that total sugar intake be continuously monitored.

• Journal of Life Science
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• v.24 no.10
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• pp.1039-1045
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• 2014

This study analyzed whether human chorionic gonadotropin (hCG) induces ER stress via the IRE/XBP1 pathway in mouse Leydig tumor (mLTC-1) cells. In a previous study, we demonstrated that the unfolding protein response (UPR) plays an important role in the expression of steroidogenic enzymes by modulating the ATF6 pathway, as well as ER stress-mediated apoptosis in hCG-stimulated Leydig cells. Although UPR signaling has been reported to regulate the IRE1/XBP1 pathway, it is not known whether hCG-induced ER stress in Leydig cells can activate the pathway. To investigate the activation of the IRE1/XBP1 pathway in mLTC-1 cells after hCG treatment, we performed a Western blot analysis to detect the phospho-IRE1 protein and an RT-PCR analysis to validate splicing of XBP1 mRNA. We used ER stress-activated indicator (ERAI) constructs for monitoring the activity of IRE1 and then analyzed by fluorescence microscopy and flow cytometry. The expression levels of the phospho-IRE1 protein markedly increased in response to the hCG treatment. In the mLTC-1 cells transfected with an F-XBP1-venus/F-$XBP1{\Delta}DBD$-venus construct, the hCG treatment led to the appearance of green fluorescent cells and detectable fluorescence in the nucleus and cytosol, respectively. In addition, splicing of XBP1 mRNA significantly increased after the hCG treatment. Taken together, these results indicate that hCG-induced ER stress leads to activation of the IRE1/XBP pathway in Leydig cells.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.170-180
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• 2014

The aim of this study was to investigate pesticide residues in 2,877 market vegetables in the northern area of Seoul in 2013. Pesticide residues in the samples were analysed by multiresidue method for 285 pesticides using GC-ECD/NPD and HPLC-DAD/FLD. 385 samples(13.4%) were detected with pesticide residues at or below MRL, and 15 samples(0.5%) were found to detect pesticide residues exceeding MRL. The most frequently detected samples were sedum(63.6%), chamnamul(45.8%), leek(44.5%) and green&red pepper(30.8%). Among the 15 violated samples, leek(5 cases) and welsh onion(4 cases) showed the highest violation rate. A total of 74 samples(18.5%) contained multiple pesticide residues in one vegetable. Procymidone, chlorofenapyr and cypermethrin were the pesticide most frequently found. As a tool of risk assessment through the consumption of pesticide detectable agricultural products, the ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was calculated into the range of 1.05~28.61%. The results have meant that there was no health risk through dieting commercial agricultural products detected with pesticide residues.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.603-616
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• 2010

Based on recent dramatic increases in foodborne outbreaks in restaurants, self-managed sanitation systems are now recommended to control contributing risk factors. This study aimed to improve sanitation management practices in restaurants and had two objectives. First, we tried to develop a self-managed sanitation check-list, including risk factors contributing to foodborne illness and Korean food hygiene regulation articles. We also tried to evaluate current sanitation management practices in restaurants according to operation and restaurant type. Thirty restaurants were evaluated by on-the-spot inspectors using an auditing tool consisting of four dimensions, seventeen categories, and forty-one items. Total compliance rate categorized by operation type significantly differed between chain restaurants and self-managed restaurants, with values of 85.5% and 51.6%, respectively. Therefore, self-managed restaurants, which showed the lowest compliance rate of below 30.0%, need more strict control to improve current unsanitary management practices, specifically relating to 'sterilization of knives, chopping boards, and wiping cloths', 'sanitation training', 'not allowing access into the kitchen to outsiders', 'handling of food or utensils on shelves at a 15 cm distance away from floor', 'prevention of cross-contamination of cooked foods or vegetables', and 'records of kitchen access or inspection'. Thus, an effective food sanitation system is essential and should be implemented to improve the existing sanitary conditions in restaurants. However, the most important factor to achieving food sanitation management objectives is food handlers' self-motivation.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.33-37
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• 2006

Bottle gourd (Lagenaria siceraria Standl.) has been used as a rootstock for the watermelon cultivation because of better growth ability at low temperature and avoidance from contamination of the soil disease. Since the genetic source for the elite rootstock is limited in nature, the genetic engineering method is inevitable to develop new lines especially to obtain the functionally important or multi-disease resistant bottle gourd. Recently, our lab has set up a successful system to transform the bottle gourd. in order to monitor the transformation process, GFP gene is used. Cotyledons of the inbred line 9005, 9006 and G5 were used to induce the shoot under the selection media with MS + 30 g/L sucrose + 3.0 mg/L BAP + 100 mg/L kanamycin + 500 mg/L cefotaxime + 0.5 mg/L $AgNO_3$, pH 5.8. The shoot was developed from the cut side of the explants after 3 weeks on the selection media. The shoot was incubated in the rooting media with 1/2 MS + 30 g/L sucrose + 0.1 mg/L IAA + 50 mg/L kanamycin + 500 mg/L cefotaxime, pH 5.8 and moved to pot for acclimation. Although the shoot development rate was depended on the genotype, the G5 was the best line to be transformed. Monitoring GFP expression from the young shoot under microscope could make the selection much easier to distinguish the transformed shoot from the non-transformed shoots.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.164-171
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• 2005

The aim of this study was to evaluate the load of nutrient from paddy fields. Water management practices that can reduce eutrophication and meet water quality requirements will also be addressed. Continuous monitoring from May to September in 2002 and 2003 was conducted for water quantification and qualification at the intensive paddy fields in Icheon, Gyunggi province of Korea. Water balance and concentration variation of nitrogen and phosphorus in the water were independently compared for water quality assessment at each rice cultivation period. Rice land preparation and transplanting periods usually marked the highest water demand when compared to other periods of cultivation. Overall, a greater net irrigation ratio was observed during the transplanting period in 2002 (92.3%) and 2003 (87.2%). The measured total N loads of precipitation, irrigation, drainage, and percolation during the rice cultivation period were 9.9, 41.6, 22.1, and $5.5kg\;ha^{-1}$ for 2002 and 15.8, 55.4, 17.3, and $7.5kg\;ha^{-1}$ for 2003, respectively. The measured total P loads of precipitation, irrigation, drainage, and percolation during the rice cultivation period were 2.1, 13.0, 3.6, and $1.8kg\;ha^{-1}$ for 2002 and 1.6, 15.0, 5.0, and $1.2kg\;ha^{-1}$ for 2003, respectively. Daily nutrient load followed the pattern of surface drainage water, but this pattern was changed by rainfall events. The nutrient load in drainage water depends on rainfall and surface drainage water amount from the paddy fields. Interestingly, the load of total N and total P output was smaller than the input load due to the natural infiltration that Occurred during the rice cultivation period. It is concluded that the paddy fields have a beneficial effect on the ecosystem and can reduce eutrophication in the water.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.555-566
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• 2013

Total maximum daily load enforced in 2004 is a program to evaluate the amount of pollutants by each land use type and manage to meet a target water quality of each waterbody. The many research to calculate runoff load of pollutants by landuse type have been studied. This study was conducted to calculate pollutants EMC, load and unit load in stormwater runoff generated from tomato growing area. Monitoring was conducted about 32 event during 4years and water quality parameters such as BOD, $COD_{Mn}$, TOC, TSS, TN, TP, $NH_3-N$, $NO_3-N$, $PO_4-P$ were analyzed at the laboratory. The average EMC were measured as follows: 9.6 BOD mg/L, 17.2 $COD_{Mn}$ mg/L, 5.5 TOC mg/L, 319.4 TSS mg/L, 4.4 T-N mg/L, 2.6 T-P mg/L, 0.5 $NH_3-N$ mg/L, 0.04 $NO_2-N$ mg/L, 2.6 $NO_3-N$ mg/L, 0.8 $PO_4-P$ mg/L. TN and TP is dichargeed as $NO_3-N$ and particle phosphorus type, respectively.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.110-118
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• 2006

The Namyang Stream in Hwaong polder was planned for several water uses including recreation, where people can contact the water and consume some amount during the recreational activity. A human health risk was assessed from exposure to E. coli in the Namyang Stream, which receives partially treated wastewater from watershed. The QUAL2E model was applied to simulate stream water quality, and this model was calibrated and verified with field monitoring data. The calibration result showed a high correlation coefficient of greater than 0.9. The mean concentration of E. coli in the Namyang Stream from the QUAL2E output was in the range of 5,000 ${\sim}$ 8,000 MPN 100 mL^{-1}$, which exceeded national and international guidelines. The Beta-Poisson was used to estimate the microbial risk of pathogens ingestion and the Monte-Carlo analysis (10,000 trials) was used to estimate the risk characterization of uncertainty. The Microbial risk assessment showed that the risk ranged from 7.9 ${\times}\;10^{-6}\;to\;9.4\;{\times}10^{-6}$. Based on USEPA guidelines, the range of $10^{-6}\;to\;10^{-8}$ was considered reasonable levels of risk for communicable disease transmission from environmental exposure, and the risk above $10^{-4}$ was considered to be in the danger of infection. Therefore, water quality of the Namyang Stream might not be in the danger of infection although it exceeded national and international guidelines. However, it was in the range of communicable disease transmission, and thorough wastewater collection and treatment at the source is recommended to secure safe recreation water quality.