• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.26-32
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• 2018

In order to analyze the effects of sediment on the occurrence of algal bloom on the Giheung Reservoir, the contamination levels of sediments were evaluated. The concentrations of various organic compounds (ignition loss), as well as the total nitrogen, total phosphorus, and heavy metals (Zn, Cr, Co, Ni, Pb, As, Hg, Cd) were analyzed in the sediments taken at eighteen sites of the reservoir. The concentrations of ignition loss and total nitrogen tended to increase from upstream to downstream, and ranged from 4.38 to 12.93% and 2,153 to 4,723 mg/kg, respectively. Heavy metals were in the order of Zn>Cr>Co>Ni>Pb>As>Hg, and the contamination level of the heavy metals was not high as a whole. The concentrations of the total phosphorus were in the range of 765 ~ 3,238 mg/kg, which exceeded the contamination level of the "Sediment Quality Assessment Guideline of River and Lake Sediment (Rule No. 2015-687 of the National Institute of Environmental Research, Korea)" at two upstream sites, four downstream sites, and all downstream sites. These results indicated that the pollution level of the total phosphorus, which is the main factor related to algal bloom, was found to be serious. Therefore, it is necessary to establish a countermeasure for sediment management in order to control the algal bloom which occurs periodically in the reservoir.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.533-542
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• 2015

In order to investigate the effect of internal loading from sediment on algal blooming at Chusori area in Daechung Reservoir, the amount and contamination level of sediment and the release rate of total phosphorus were analyzed. The sedimentary layer was consisted with two layers, and the average depth of upper and lower ones were 0.35 and 1.44 m, respectively. The fraction of inorganic phosphorus in the sediment was higher than that of organic phosphorus, and the fractions of phosphorus which responsible for internal loading were very high as in the range of 72.7 and 80.2% of inorganic phosphorus. The C/N ratio of sediment taken with core sampler indicated the organic compounds are originated from settled algae from water body. The average release rate of total phosphorus from sediment was $6.74({\pm}0.50)mg/m^2/day$. These results indicated that the internal loading from sediment contributes the excessive algal growth at Churosi area, and the countermeasures to improve the quality of sediments are required to manage algal blooming in Daechung Reservoir.

• Journal of Nutrition and Health
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• v.39 no.4
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• pp.338-346
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• 2006

The overall purpose of this study was to investigate the effects of level of isoflavones supplementation on bone metabolism in growing female rats. The effects of level of isoflavones supplementation on bone mineral density (BMD) and bone mineral content (BMC) were inspected in this study. Forty-five rats divided into three groups: Casein, $^1/{_2}IF$, IF. The serum and urine concentrations of calcium and phosphorus were determined. BMD and BMC were estimated by using PIXImus (GE Lunar Co, Wisconsin.) in spine and femur on 3, 6, 9 weeks after feeding. This study of results were as follows: The isoflavones supplementation level did not affect weight gain, mean food intake and food efficiency ratio. The serum concentration of calcium, phosphorus were not significantly different by different level of isoflavones supplementation. The urinary calcium and phosphorus excretion were not significantly different, too. Spine and femur BMD, BMC were not significantly increased by different level of isoflavones supplementation on 3 and 6 weeks after feeding. Spine BMD and spine BMC per weight, femur BMC per weight were significantly increased in the groups $^1/{_2}IF$ and IF at the ninth week after feeding, but there was no significant difference by different level of isoflavones supplementation. Spine BMD per weight and femur BMD per weight were significantly higher in the group of IF than in the group of Casein and $^1/{_2}IF$ at the ninth week after feeding. These results suggest that the group of IF with rich isoflavones supplementation was effective to the increase of BMD spine and femur in growing female rats, respectively.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.19-23
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• 2000

The effects of microbial phutase on laying performance and phosphorus utilization were examined at different levels of dietary nonphosphorus(NPP) in 320 23-week-old Hy-line brown hens for 12weeks. Diets were formulated 0.275%(T1), 0.220%(T2), 0.165%(T3) of NPP levels, and supplemental microbial phytase was 300DPU/kg diet constantly. Conventional diet(C) was formulated 0.275% NPP level without microbial phytase. Egg production and egg mass were higher in T2 than the others (p<0.05), and average egg weight was higher in T1 than the other (p<0.05). Egg productivity was tended to increase with supplemental phytase compared to conventional diet. Daily feed intake a hen also increased in T2 (p<0.05). Feed conversion ratio was improved slightly without significant difference. Eggshell breaking strength and thickness were not different significantly among the treatments. Haugh unit and yolk color were also not different. Calcium and phosphorus retention in body increased in T2 (p<0.05), but dry matter and nitrogen retention were not different significantly. Differences in nitrogen and calcium excretions were not found among the treatments. But phosphorus excretion decreased in order of dietary phosphorus levels with supplement phytase compared to C (p<0.05). Tibial ash, calcium and phosphorus were similar among the treatments. In conclusion, supplemental microbial phytase in laying diet may help to utilize phytase phosphorus, and could decrease NPP intake.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.197-202
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• 1999

Three barrows weighing 45.0 kg, fitted with simple T-cannulas in both the duodenum and terminal ileum, were assigned to diets in a $3{\times}3$ Latin Square design experiment to determine the effect of two calcium levels (0.8% vs 0.4%) on phytase activity and nutrient balance in growing pigs. The control diet contained 0.8% calcium, with no added inorganic phosphorus (0.45% total phosphorus) and no added phytase. The two additional experimental diets contained microbial phytase (750 phytase units/kg) and supplied either 0.8% or 0.4% calcium. With added microbial phytase, ileal and total tract digestibility of rotal phosphorus were improved by 20.9 and 13.8 percentage units, respectively (p=0.01). The apparent duodenal and ileal digestibility of phytate phosphorus were increased by 51.8 and 49.7 percentage units (p=0.01). Lowering dietary calcium in the presence of microbial phytase increased the digestibility of phytate phosphorus by an additional 10.9 (p=0.001) and 5.7 percentage units for duodenal and ileal digestibility, respectively. Supplementation with microbial phytase significantly reduced fecal excretion of nitrogen and phosphorus and increased the percentage of these nutrients retained by the pig. Lowering dietary calcium further increased the percentage of dietary phosphorus retained. Overall, reducing dietary calcium appeared to increase the effectiveness of added microbial phytase in degrading phytate phosphorus. As a result, care should be taken to avoid high levels of dietary calcium when supplementing swine diets with microbial phytase.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.25-30
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• 2000

Present study was conducted to investigate effects of microbial phytase in laying hen diets on utilization of non-phytate phosphorus(NPP) whose levels were adjusted to be adequate or lower than that of NRC requirements. Birds of control roup were fed a diet containing 0.275% NPP and 3.4% Ca, satisfying the NRC(1994) feeding standard. bird on T1, T2 and T3 were allowed to eat diets containing NPP at 100, 80 and 60%, respectively, of Control group, and 4.0% Ca level along with a microbial phytase added at a level of 300 DPU. Three hundred and sixty, ISA Brown layers, 23-week-old, divided into four treatment groups with three replications per treatment and 30 layers per replication were fed the diets for 12 weeks. Levels of feed intake were not different among the groups, The egg mass/feed intake ratio appeared better in T2 group by about 8%, though without a statistical significance, compared to that of control. Egg production fate tended to be improved over the control group by feeding the 100%(T1) and 80%(T2) NPP diets added with phytase, with a significant difference for T2(p<0.05). Mean egg weight and egg shell quality, measured by breaking strength and thickness of the egg shell, of the T2 group tended to show numerically better, without a significance than those of control. Furthermore, birds of the T2 group showed higher calcium and phosphorus contents in tibia by about 9%(p<0.05) than the control. Overall performances of birds in T1 appeared better than those of control, but tended to be lower than those of the T2. The birds in T3 performed similar to the those of the other dietary groups except the relatively low tibia calcium level. In conclusion, the results of this study suggest that supplementation of microbial phytase at a level of 300 DPU was effective to spare about 20% of NPP in laying hen diets without any adverse effects on production performances and bone quality.

• Applied Biological Chemistry
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• v.30 no.1
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• pp.9-16
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• 1987

This experiment was conducted to increase the available constituents contents of Angelica gigas Nakai and to decide the application amounts of nitrogen, phosphorus and potassium fertilizer. The effects of the amounts of their application and absorption on the contents of decursin and sugar in Angelicae gigantis Redix were studied. The decursin contents of root was decreased with increasing the application amount of nitrogen more than 10kg/10a, and increased along with the increasing application level until 20kg/10a and 15kg/10a of phosphorus and potassium, respectively. The decursin yield per 10a was increased with increasing application level until 10kg/10a, 10kg/10a and 10kg/10a of nitrogen, phosphorus and potassium, respectively. The decursin yield per l0a was decreased with increasing application level more than 20kg/10a of nitrogen. The total sugar yield per 10a was increased with increasing the application level until 15kg/10a, 10kg/10a of nitrogen and potassium respectively. But the effect of phosphorus application on the total sugar yield was not observed. The significant negative correlation was obtained between the decursin contents and the nitrogen contents of root$(r=-0.437^{\ast})$, and the significant positive correlation between the decursin contents and the contents of phosphorus$(r=0.587^{{\ast}{\ast}})$ or potassium$(r=0.467^{\ast})$ in root. But the significant correlations between the decursin contents and the their contents of shoots were not observed. It is recommended for decursin production to apply 10kg/10a, 15kg/10a and 10kg/10a of nitrogen, phosphorus and potassium, respectively.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.433-439
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• 2001

Intakes and excretions of calcium and phosphorus were determined for 8 female adolescents(aged 16.3$\pm$0.5y; body mass index 20.4$\pm$1.3kg/$m^2$; body fat 33.3$\pm$2.5%; bone mineral density of lumbar spine in L2-L4; 0.96$\pm$0.08g/$\textrm{cm}^2$) when they consumed diets basal and high in calcium for 6 days each. All subjects consumed a basal Ca diet containing 800mg, Korean RDA level of the subjects, and a high Ca diet containing 1200mg, RDA plus 2 SDs of calcium intake. The diets provided 58% of energy intake as carbohydrate, 25% as fat, and 17% as protein. Food, urine, and fecal composites were collected during the last 3 days of each feeding period. Fecal excretion of calcium was significantly greater on the high Ca than on the basal Ca diet. Hence, apparent absorption rate was significantly lowered from 40.9% on the basal Ca diet to 33.1% on the high Ca diet. There was no significant difference in calcium retention between the two diet periods but it tended to be greater on the high Ca diet. However, excretions and retention of phosphorus did not show any significant difference even though intake was significantly increased from 1,253mg on the basal Ca diet to 1,583mg on the high Ca diet. The results indicate that higher calcium intake than the Korean RDA level is recommended for adolescents to meet peak bone mineral accretion and attain a desirable level of calcium retention. (Korean J Nutrition 34(4) : 433~439, 2001)

• Journal of Korean Society on Water Environment
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• v.34 no.3
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• pp.270-284
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• 2018

Paldang is a river reservoir located in the Midwest of Korea, with a water volume of $244{\cdot}10^6m^3$ and a water surface area of $36.5km^2$. It has eutrophied since the construction of a dam at the end of 1973, and the phosphorus concentration has decreased since 2001. Average hydraulic residence time of the Paldang reservoir is about 10 days during the spring season and 5.6 days as an annual level. The hydraulics and water quality of the reservoir can differ greatly, both temporally and spatially. For the spring period (March to May) in 2001 ~ 2017, the reservoir mean total phosphorus concentration calculated from the budget model based on a plug-flow system (PF) and a continuous stirred-tank reaction system (CSTR) was 13 % higher and 10 % lower than the observed concentration, respectively. A composite flow system (CF) was devised by assuming that the transition zone was plug flow, and that the lacustrine zone was completely mixed. The mean concentration calculated from the model based on CF was not skewed from the observed concentration, and showed just 6 % error. The retention coefficient of the phosphorus derived from the CF was 0.30, which was less than those of the natural lakes abroad or river reservoirs in Korea. The apparent settling velocity of total phosphorus was estimated to be $93m\;yr^{-1}$, which was 6 ~ 9 times higher than those of foreign natural lakes. Assuming CF, the critical load line for the total phosphorus concentration showed a hyperbolic relation to the hydraulic load in the Paldang reservoir. This is different from the previously known straight critical load line. The trophic state of the Paldang reservoir has recently been estimated to be mesotrophic based on the critical-load curve of the phosphorus budget model developed in this study. Although there is no theoretical error in the newly developed budget model, it is necessary to verify the validity of the portion below the inflection point of the critical-load curve afterwards.

• Korean Journal of Community Nutrition
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• v.5 no.2
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• pp.273-279
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• 2000

This study was carried out to evaluate the calcium and phosphorus intakes and correlation with growth performance of 25male breast and formula-fed infants from 1 to 3 months postpartum. There were four groups breast-fed(BF) and three formula-fed groups(FFM, FFN and FFP). There was no significant difference in the height and weight of infants according to feeding methods and formula brands. Milk intake and the concentration of calcium and phosphorus from human milk and the formulas were measured. The average calcium content of human milk was 26.6$\pm$4.1mg/dl and 13.5$\pm$2.0mg/dl, respectively. The average calcium intakes of the brest-fed and formula-fed infants were 205.5$\pm$29.3mg/day and the 460.5$\pm$70.6mg/day, respectively the average calcium intake of breast-fed infants was significantly lower than that of formula fed infant. The percent of RDA(41%) of breast-fed infants was lower than that(75.4%) of formula fed infant. The average phosphorus intake of the brest-fed and formula-fed infants were 105.1$\pm$20.1mg/day and 288.3$\pm$37.3mg/day, respectively. The precent of RDA(27%) for brest fed was significantly lower than that(75.4%) of formula fed. The Ca/P ratios were 2.1 in brest fed and 1.6 in formula fed infant. The average calcium and phosphorus intakes of the formula fed infants was higher than that of the brest-fed infants. This data suggests the calcium and phosphorus intakes form human milk sufficiently support the growth of infants. Therefore, the level of calcium and phosphorus recommended dietary allowances for infants should be reduced.