• The Korean Journal of Ecology
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• 제14권2호
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• pp.171-179
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• 1991

In this study, the balnce of the litter production and decompsition on the forest floors in the green belt nearby seoul, which had been established in 1972, and turnover cycles of minerral nutrients were inverstigated. litter production and decomposition in the forests of quercus accutissima, q, serrata, q. mongolica, salix koreensis and alnus hirsuta were reached at the equilibium stated from 1972 to 1988 but this balance in the pine forest of pinus densiflore and p. rigida was not. Under the forests in the blance of the litter production and decomposition, the maximum amounts of n, p, k, ca and na retured to soil annually were 4.9g/㎡ in the alnus hirsuta forest, 0.35g/㎡ in the salix koreensis forest, 2.70g/㎡ in the quercus accutissima forest, 8.85g/㎡ in the s. koreensis forest and 3.93g/㎡ in the s. koreensis forest, respectively, and the minimum were 2.8g/㎡ in the s. koreensis forest, 0.108g/㎡ in the q. mongolica forest, 0.06g/㎡ in the s. koreensis forest, 2.12g/㎡ q. mongolica forest and 0.15g/㎡ in the q.accutissima forest.

• 대한지역사회영양학회지
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• 제8권5호
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• pp.689-698
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• 2003

The purpose of this study was to evaluate the relationship between the diversity of food intake and nutrient intake among Korean college students participating in a nutrition education class via the internet. The subjects were 796 college students throughout South Korea (278 males, 518 females). A 3 days dietary recall survey was conducted and results were analyzed using the Computer-aided Nutritional Analysis Program. Dietary variety was assessed by DDS (dietary diversity score), MBS (meal balance score), and DVS (dietary variety score). Dietary quality was assessed by NAR (nutrient adequacy ratio), and MAR (mean adequacy ratio). As the DDS, MBS and DVS increased, the NAR and MAR improved. The subjects with a DDS of above 4 or a MBS of above 10 or a DVS of above 11 met two-thirds of the Korean recommended dietary allowance for most nutrients. The DDS, MBS and DVS correlated positively and significantly with the NAR and MAR. Associations between the NAR and high levels of DVS were more positive than those between the NAR and the DDS. Based on these results, the food intake of these subjects was not adequate. Specially, the dietary intake of calcium and iron were not adequate. Therefore, dietary guidelines should be made considering nutritional characteristics so as to improve the intake from all of the major food groups and provide a variety of foods in their diets.

• Journal of Nutrition and Health
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• 제34권1호
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• pp.54-61
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• 2001

The Ca and P balance studies were carried out with two different diets varying Ca levels : the current Korean RDA level(normal Ca diet) and the high level (High Ca diet) which was determined by adding 2SD to mean Ca intake of all subjects. The subjects were sever healthy adult woman, aged from 25 to 32 years old. The metabolic studies were conducted for two weeks with a days recess in between : during the fist week with normal Ca diet and during the second week with high Ca diet. The composition of nutrients excepting Ca of both diets was similar to subjects usual intake. The result were summarized as follows: Mean daily Ca intake was 728.8mg from norma Ca diet and 945.5mg from high Ca diet. Fecal excretion of Ca increased significantly(p<0.05) on high Ca diet, but urinary excretion of Ca did not show any differences between the two diet periods. There were also no significant differences in Ca retention between the two diet periods but it tended to be greater during high Ca diet period: 112.1mg/day during normal Ca diet period vs 208.2mg/day during high Ca diet period. Mean apparent Ca absorption was 41.2% on normal Ca diet and 42.1% on high Ca diet, indicating it was not affected by high Ca intake level used in this study. On the contrary, P retention was significantly increased up to 109.4mg/day with high Ca diet as compared to- 41mg/day with normal Ca diet. There were no significant differences in fecal and urinary excretion of P but those to be lower during high Ca diet period. The above results showed that higher Ca intake more than current RDA(700mg/day), in the level of 945.5mg/day, could increase Ca retention through Ca absorption comparable to the rate appeared on RDA level intake. P retention was also improved by high Ca intake. Therefore, higher Ca intake than the current RDA level seemed to produce favorable effects on bone health in adult women. However, the current RDA level seemed to be relatively appropriate, considering the results that all the subjects but one maintained positive Ca balance with normal Ca diet. (Korean J Nutrition 34(1):54-61, 2001)

• Nutritional Sciences
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• 제4권1호
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• pp.34-38
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• 2001

The purpose of this study was to compare the energy expenditure of normal-weight and overweight Korean middle-aged women (40-60 yr). Middle-aged oveweight ($BMI\;{\geq}\;25$, n= 20) and normal-weight women were ($BMI\;{\leq}\;23$, n = 20) were recruited in Seoul. Anthropometric measurements, body composition, energy intake, daily activity time, and energy costs of some daily activities were measured. Energy expenditure at rest and while reading the newspaper, washing dishes, mopping the floor, and walking on a treadmill at 1.0, 2.0, 3.5mph were measured by indirect calorimeter and total daily energy expenditure was estimated by summation of energy costs of different activities. The overweight group had significantly higher values of body weight, triceps skinfold thickness, thigh circumference, waist circumference, hip circumference, BMI, WTR, WHR, body surface area, percentage body fat, fat mass, fat free mass (FFM), and muscle mass compared to normal-weight group. The energy intakes of both groups were close to RDA and other nutrient intake status was also satisfactory. There were no significant differences in intakes of energy and nutrients between the two groups. Overweight subjects showed lower energy expenditure per kg body weight for reading the newspaper, washing dishes and mopping the floor, and walking on a treadmill at 2.0 and 3.5 mph, however, energy expenditure per kg FFM did not differ between the two groups. Daily energy expenditure for all activities was significantly higher in the overweight compared to the normal-weight group due to higher body weight. Both overweight and normal-weight groups showed negative energy balance between energy intake and energy expenditure, and there was no significant difference in energy balance between the two roups. Total daily energy expenditure correlated highly with FFM and body surface area. The result of present study does not offer an explanation on the energy imbalance and weight gain of overweight women.

• Asian-Australasian Journal of Animal Sciences
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• 제2권1호
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• pp.7-16
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• 1989

To determine the effect of sodium plus potassium to chloride ratio and lysine level on blood pH, blood acid-base parameters, lysine-arginine antagonism and growth performance, four hundred and thirty two chicks of 3 days age were used in a completely randomized $3{\times}3$ factorial experiment. Variables contained three levels of lysine (0.8, 1.2 and 1.6%) and dietary electrolyte (100, 200 and 300 mEq/kg). Birds fed 200 mEq/kg and electrolyte had the best growth rate and feed efficiency, followed by those fed 300 mEq/kg and 100 mEq/kg electrolyte. It is proposed that high levels of dietary electrolyte may improve the growth of chicks fed diets containing excess lysine by increasing lysine catabolism. High or low levels of lysine and dietary electrolyte resulted in higher mortality than those of optimum level (1.2%) of lysine and 200 mEq/kg of electrolyte balance. When the electrolyte level was increased, the pH, $pCO_2$, base excess, $HCO_3{^-}$ and total $CO_2$ of blood plasma were increased. The utilization of nutrients was changed when the electrolyte and lysine were manipulated. Plasma chloride tended to be greater in chicks receiving high chloride diet and was the highest in chicks fed the high lysine diet. Plasma sodium and potassium were unaffected by dietary lysine. Diet containing high lysine decreased the level of arginine and excess dietary electrolyte increased arginine level in plasma. It may be concluded that cation supplementation tended to alleviate the lysine-arginine antagonism but chloride exacerbated. Tibia bone length and ash contents were significantly affected by electrolyte balance and lysine level.

• Ocean and Polar Research
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• 제38권1호
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• pp.81-88
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• 2016

In many fish species, including Nile tilapia (Oreochromis niloticus), gonadal development occurs at the expense of stored energy and nutrients. Therefore, reproductive systems are inhibited by limited food supply. It has been well established that reproductive function is highly sensitive to both metabolic status and energy balance. Nothing is known about the possible mediated connection between energy balance and reproduction. Kisspeptin, a neuropeptide product of the Kiss gene has emerged as an essential gatekeeper of reproduction and may be possibly be linked to energy balance and reproduction in non-mammalians. Thus, in this study, the effect of fasting (10 days) on the expression of kisspeptin and the gonadotropin-releasing hormone (GnRH) gene were assessed in Nile tilapia (male and female) using qRT-PCR. In addition, plasma levels of estradiol-$17{\beta}$ ($E_2$) and 11-ketotestosterone (11-KT) in adult tilapia were measured by ELISA. In male tilapia, fasting reduced Kiss2 and GnRH I mRNA expression in the brain and 11-KT level in comparison with the fed tilapia (p < 0.05). In females, however, there were no significant differences in GnRH I mRNA expression and $E_2$ between fish subjected to fasting and those fed (p > 0.05). These data indicate the impact of nutritional states on kisspeptin as a potential regulatory mechanism for the control of reproduction in male Nile tilapia.

• 한국미생물·생명공학회지
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• 제31권4호
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• pp.435-438
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• 2003

Iron required by all organisms is related with diverse biological processes. Most eukaryotes need extra iron to maintain their nutrition balance. However, extra iron supplement gives many problem to solubility in the cells. To increase the bio-availability of iron in cells, yeast was applied to carry the iron with solubility. Selection of yeast mutants with enhanced iron uptake were performed by mutagenesis using the alkylation agent EMS. Eleven mutant strains with enhanced iron uptake were selected by the measurement of iron content with atomic absorption spectrometer. The iron content in mutants was 1.5- to 2.5-fold more than that in wild-type. These mutants could be served as iron-fortified nutrients for food and feed.

• 동아시아식생활학회지
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• 제7권1호
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• pp.107-115
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• 1997

The purpose of this study was to investigate of nutritional status, a intention for dietary inprovement and a degree of dietary satisfaction of Buddhist nuns9age 23~43yr). The survey was carried out through physical examination and questionaries at Woon Mun temple in Kyungpook province September through Octoer in 1996. The results are summarized as follows: 1) All nutrients were higher than recommended daily allowances, and the ratios of carbohydrate:protein: lopid from total calories was 76:13:11 respecting ; 2) In degree of dietary satisfaction: satisfaction, between, dissatisfaction were 55.47, 36.59, 7.93% of subjects. 3)In intention for dietary improvements : the s\ulcorner way, a little improvements, much improvements were 55.47, 41.46, 3.07%. 4) Diet type were in regular sequence of volume, gourmet ; balance ; diet ; fast food type.

• Journal of Dairy Science and Biotechnology
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• 제19권1호
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• pp.30-38
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• 2001

The most important task in Korean dairy industry is to keep the seasonal and annual balance of raw milk supply and demand. Too much surplus milk supply which causes dumping sale of market milk makes dairy industries get in trouble of management, and eventually affects to farmers and consumers economically. As balancing of supply and demand is so important in the fee economic market system, the adaption of the quota system of milk production and seasonal price differentiation has been recommended very often as a method of controlling the milk supply and demand. However, this recommendation did not go through successfully due to the strong objection of dairy farmers. Recently, the voice of consumer's requirement for safer and more hygienic, and high protein, low fat level dairy product is getting stronger. By knowledge of this kind changes, quality improvement in nutrients and hygiene is the most positive way to expand the volume of milk consumption. To meet the consumer's demand, therefore, it is necessary to revise the level of milk fat content and the hygienic grading system for the payment system of raw milk.

• 한국농공학회지
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• 제43권6호
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• pp.154-162
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• 2001

This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.