• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.551-556
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• 2020

Eel Anguilla japonica is an economically important inland culture fish species in East Asian countries, particularly in Korea, Japan, China, and Taiwan. In this study, the effects of feeding frequency on larval growth and survival rate were investigated. Eel larvae (average length, 6 mm) were fed a slurry-type diet containing shark eggs three, five, seven, or nine times per day. Survival rates differed significantly among the four experimental groups. Feeding frequencies of at least five and seven times a day were required until 15 and 30 days after hatching, respectively, to maintain an acceptable survival rate. Leptocephalus growth improved with increased feeding frequency until 15 days after hatching. The results suggest that providing an opportunity for early food intake enhances eel survival and growth in the early leptocephalus stage.

• Journal of Nutrition and Health
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• v.20 no.1
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• pp.54-64
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• 1987

The purpose of this study is to computerize all the necessary information on the daily food value and nutritional status for individuals and groups. In this research, a FOCUS-16jXT (16 bit personal computer ) compatible with IBM-PCjXT was used, and the database files and programs were created by using the dBASEIII package. The food life evaluation system consists of 3 subsystems of Reference, Nutrition Status Assessment and Food Source. The findings are summerized a8 follows: 1. Reference: This subsystem enables users to proceed to the next step, if necessary, by describing each subsystem. 2. Nutrition Status Assessment. 1) Food Habit Assessment: This subsystem determines whether the user has a good food habit or not, based on the answers for ten questions about daily food life. 2) Obesity Assessment: This subsystem calculates Broca index, which is used as a indicator of obesity. 3) Nutrient Intakes: When personal data such as age, sex, weight, height and food consumptions are input, it is possible to calculate the followings. i) Comparison between the amounts intaked and the recommended dietary daily allowances of various nutrients ii) Nutrient intakes from each food group and their composition rates for the nutrients iii) Nutrient intakes per unit body surface area iv) Composition of lipid intake 3. Food Sources: The appropriate food sources for the lacking nutrients will be recommended to the subjects.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.369-374
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• 1992

In order to determine the effect of dietary cellulose levels on chick performance, 1-week-old White Leghorn male chicks were fed semi-purified diets containing either 5%, 10%, 15% or 20% cellulose for 3 weeks. All diets were iso-nitrogenous and iso-caloric. Feed intake and body weight were increased as the cellulose level was increased. Feed conversion was lower in the 5% cellulose diet than in the other diets. Compared to the case of 10% to 20% cellulose diets, relative length (per 100 g body weight) of esophagus, duodenum, small intestine and cecum was longer, and relative weight of esophagus, duodenum and crop was also heavier in the chicks fed the 5% cellulose diet. The other internal organs were not affected by the cellulose level. The retention rates of dry matter and nitrogen were lower in the 5% cellulose group than in the other groups. Concentration of carcass phospholipids was higher in the 5% cellulose group, and that of carcass cholesterol was increased as the cellulose level increased. In conclusion, the dietary cellulose level should be more than 5% to give an adequate chick performance, and no ill effect was found even at 20% level.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.82-89
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• 2011

Ultra lean combustion with stratified air-fuel mixture is one of the methods that can improve fuel economy of gasoline engines. The aim of this study is to show that how much fuel economy is improved and what are differences in engine control of the ultra lean combustion compared with stoichiometric combustion. In this study, the BMW N53 GDI engine, which is one of ultra lean combustion GDI engines introduced in the market recently, was tested at various engine operating conditions. Results indicated that fuel consumption rates were improved by 11.9~25.8% by the ultra lean combustion compared with stoichiometric combustion. It was also found that multiple fuel injection, multiple spark, early intake valve opening, and large vlave overlap duration were the features of the ultra lean combustion for combustion stability and emission improvement.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.144-152
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• 2006

Split injection has been known to reduce total hydrocarbon (THC) emission level and increase engine performance under certain operating conditions 1, 2). Exhaust Gas Recirculation (EGR) is a common technique adopted for nirtric oxides (NOx) reduction by the dilution of intake air, despite a sacrifice of simultaneous increase in THC and decrease in engine performance3). Thus, using split injection with adequate EGR may improve the emission level of UBHC, NOx and the engine performance compared to that of single-injection with or without EGR cases. The purpose of this study is to investigate the engine performance and emission levels at various engine operating conditions and injection methods when it is applied with EGR. The characteristics of single-injection and split-injection were investigated with various engine loads and EGR rates. The engine speed is changed from 800rpm to 1200rpm to investigate how the combustion characteristics are changing with increasing engine speed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.840-846
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• 2014

This study investigated growth and hematological changes in parrotfish Oplegnathus fasciatus (~200 g/fish) reared under different total ammonia nitrogen (TAN) concentrations (0, 4, or 8 mg/L) for 6 weeks. Survival rates of parrotfish in all experimental groups did not significantly differ, as they were all ~100%. Although specific growth rate (SGR), weight gain, and daily feed intake in the high TAN concentration group (TAN8) were significantly lower than in the other two groups, there was no significant difference between the TAN4 group and the control group, (TAN0), indicating that parrotfish have a strong resistance to ammonia toxicity. As for temporal changes of the major blood components, cortisol increased as a result of stress caused by the high ammonia concentration in the TAN8 group. For this reason, the concentrations of energy sources such as glucose and total cholesterol were reduced. However, there was little difference among all experimental groups in concentrations of liver function glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), and nutrient factors, such as total protein and albumin.

• Environmental Engineering Research
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• v.18 no.4
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• pp.221-227
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• 2013

A risk assessment of environmental media was performed for the inhabitants in the area of the abandoned Nokdong metal mine. Soil, groundwater, and crop samples were collected from September to October 2008 around the mine. After pretreatment of these samples, metal concentrations were measured, and a risk assessment was performed using the Korean soil-contamination risk assessment guidelines. Lead (Pb) and arsenic (As) intake rates were the highest for inhalation of soil dust. The cancer risks from ingestion of As-contaminated groundwater, inhalation of As-, Cd-, and Pb-contaminated soils, and contact of As-contaminated soils exceeded the acceptable risk. The sum of all carcinogenic risks was $9.29{\times}10^{-3}$. The non-carcinogenic risk was highest for ingestion of As-contaminated water (11.0), followed, in descending order, by inhalation of Hg-contaminated soil and ingestion of Pb-contaminated water. Most of the risks were associated with As, Cd, Pb, and Hg contamination, and therefore, these metals were considered to be potential toxic carcinogens and non-carcinogens for humans in this area. In this study, the non-carcinogenic risks of ingestion of contaminated water or crops, as well as those associated with the inhalation of soil dust were observed.

• Journal of Preventive Medicine and Public Health
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• v.46 no.4
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• pp.173-182
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• 2013

Obesity during childhood is a dominant risk factor for noncommunicable diseases (NCDs), and is itself considered a disease that needs to be treated. Recently, the growth in childhood obesity in Korea has become stagnant; however, two in every ten children are still overweight. In addition, 60% or more of overweight children have at least one metabolic syndrome risk factor. Thus, childhood obesity should be controlled through lifestyle modification. This paper reviews studies of the modifiable risk factors of obesity in Korean children. According to the life-course approach, preschool-aged children (<5 years) are influenced by their parents rather than individual habits because they are under mostly parental care. Elementary school-aged children (6 to 11 years) are affected by overlapping individual and parental effects. This may mean that the establishment of individual behavior patterns begins during this period. The conditions of poor eating habits such as skipping meals, eating out, and high fat intake, along with low physical activity, facilitate increased obesity among adolescents (12 to 18 years). Notably, adolescent girls show high rates of both underweight and obesity, which may lead to the development of NCDs in their offspring. Therefore, the problem of NCDs is no longer limited to adults, but is also prevalent among children. In addition, early intervention offers cost-effective opportunities for preventing NCDs. Thus, children need primary consideration, adequate monitoring, diagnosis, and treatment to reduce the burden of NCDs later in adulthood.

• Korean journal of food and cookery science
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• v.19 no.3
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• pp.390-395
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• 2003

The purposes of this study were to identify the attributes of food and service quality, to examine the levels of satisfaction and plate wastes leftover in school meals and to determine the relationship between student satisfaction and plate wastes. A questionnaire was administrated to 1000 elementary students. The respondents comprised of 505 boys and 494 girls. The satisfaction score with the food service quality was rated as 'average', with a score of 3.06 out of 5. The quality attributes of the food service were categorized into three aspects, which included food, service and hygiene. The satisfaction scores for the food- and hygiene-related factors were 3.20 and 3.24, respectively. However, the aspect of service was rated at 2.74, indicating a low level of satisfaction. The intake rates of soup, kimchi, fish and vegetables were lower than those of other types of foods. Two groups, a no-leftovers group and a leftovers group, were classified based on whether students ate all or left foods. The satisfaction scores for the school food service attributes between the two groups revealed that the no-leftovers group was more highly satisfied with the food service quality than the leftovers group (p＜0.001).

• Molecules and Cells
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• v.44 no.2
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• pp.116-125
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• 2021

Cardiovascular diseases (CVDs) are the most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) and dyslipidemia is considered at least partially responsible for the increased CVD risk in NAFLD patients. The aim of the present study is to understand how hepatic de novo lipogenesis influences hepatic cholesterol content as well as its effects on the plasma lipid levels. Hepatic lipogenesis was induced in mice by feeding a fat-free/high-sucrose (FF/HS) diet and the metabolic pathways associated with cholesterol were then analyzed. Both liver triglyceride and cholesterol contents were significantly increased in mice fed an FF/HS diet. Activation of fatty acid synthesis driven by the activation of sterol regulatory element binding protein (SREBP)-1c resulted in the increased liver triglycerides. The augmented cholesterol content in the liver could not be explained by an increased cholesterol synthesis, which was decreased by the FF/HS diet. HMG-CoA reductase protein level was decreased in mice fed an FF/HS diet. We found that the liver retained more cholesterol through a reduced excretion of bile acids, a reduced fecal cholesterol excretion, and an increased cholesterol uptake from plasma lipoproteins. Very low-density lipoproteintriglyceride and -cholesterol secretion were increased in mice fed an FF/HS diet, which led to hypertriglyceridemia and hypercholesterolemia in Ldlr-/- mice, a model that exhibits a more human like lipoprotein profile. These findings suggest that dietary cholesterol intake and cholesterol synthesis rates cannot only explain the hypercholesterolemia associated with NAFLD, and that the control of fatty acid synthesis should be considered for the management of dyslipidemia.