• Journal of the korean society of oceanography
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• v.32 no.3
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• pp.145-155
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• 1997

The distribution of microzooplankton and hydrographic variables were measured in the Virginia portion of Chesapeake Bay and its major rivers. Samples were collected at 14 locations at monthly interval from September 1993 through December 1995. Ciliates were numerically dominated (>90%) and copepod nauplii comprised highest proportion of the total microzooplankton biomass (>77%). Copepod nauplii and ciliates were the most abundant at oligohaline water and rotifers at freshwater. Total microzooplankton density and biomass were usually higher at oligohaline stations than fresh water and polyhaline stations. Despite high nutrient concentration and phytoplankton density at eutrophic water, micro- and mesozooplankton biomass were low. Mesozooplankton were relatively abundant at polyhaline stations. The comparison between annual mean biomass of ciliates (12.7 ${\mu$}gC/1) and that of autotrophic picoplankton (13.5 {$\mu$}gC/1) revealed that ciliates were a major consumer of picoplankton production. The secondary production by ciliates was 12.7 ${\mu}$gC/1/day, representing 5% of the annual mean primary production in Chesapeake Bay, Total microzooplankton comprised 84% of the total zooplankton carbon content, representing five times higher than mesozooplankton biomass.

• 한국유가공학회:학술대회논문집
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• 2007.09a
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• pp.31-37
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• 2007

An understanding functional properties and molecular interactions of milk proteins was critical to improve qualities of fermented dairy products including yogurts and cheeses. Extensive rearrangements of casein particles were important factors to enhance whey separation in yogurt gel network. The use of high hydrostatic pressure treated whey protein as an ingredient of low fat processed cheese food resulted in the production of low fat processed cheese food with acceptable firmness and enhanced meltabilities. Milk protein-based nano particles produced by self-association of proteins could be better nutrient delivery vehicle than micro particle since particle size reduction in nano particles could lead to increased residence time and surface area available in GI tract.

• Journal of Plant Biology
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• v.38 no.4
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• pp.321-328
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• 1995

Calli obtained from basal disc explants of Allium victorialis var.platyphyllum wre grown in three kinds of nutrient media (MS, BDS, and B5), and the frequencies of mitotic index and the chromosomal aberrations were analysed. The mitotic index varied from 0.55% to 1.01% with respect to culture media and ages. The mitotic irregularities like micro-, bi- and multi-nuclei, chromosome bridge and laggards were noted in each types of calli. The chromosome number variations observed in metaphase stage were identified aneuploid and tetraploid. Structural variations such as dicentric chromosomes, centromere breakage and small chromosomes were observed. Relationship between basal medium and chromosomal variability was not observed in this study. But, in BDS medium, NAA and BA had a more effect on number variation than kinetin.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.2
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• pp.143-151
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• 1997

The purpose of this study was to investigate the effect of iron and selenium intakes on utilization of manganese in rats fed adequate, 2-fold, 4-fold iron and adequate, high selenium for 6 weeks. There was no difference feed intake across iron and selenium containing diet groups. Body weight gain in 2-fold iron and high selenium group(MFeHSe) was significantly higher than those in other groups. Serum iron level was increased with iron increment, and liver iron content was decreased with selenium supplementation. Selenium and manganese contents in tissues were decreased with iron increment. In the case of manganese balance, manganese excretion through feces was significantly increased as iron intake was increased. However, retention and apparent absorption of manganese were not significantly affected by dietary iron. From these results, it could be suggested that the supplementations of iron and selenium affected the manganese utilization. Therefore, it must be considered interaction with various minerals in micro-nutrient supplementations.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1600-1607
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• 2014

A total of 120 finishing pigs ([Yorkshire${\times}$Landrace]${\times}$Duroc) with an average body weight (BW) of $49.72{\pm}1.72kg$ were used in 12-wk trial to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, fecal micro flora, meat quality and fecal gas emission. Pigs were randomly allotted to one of three dietary treatments (10 replication pens with 4 pigs per pen) in a randomly complete block design based on their initial BW. Each dietary treatment consisted of: Control (CON/basal diet), OA1 (basal diet+0.1% organic acids) and OA2 (basal diet+0.2% organic acids). Dietary treatment with protected organic acid blends linearly improved (p<0.001) average daily gain during 0 to 6 week, 6 to 12 week as well as overall with the increase in their inclusion level in the diet. The dry matter, N, and energy digestibility was higher (linear effect, p<0.001) with the increase in the dose of protected organic acid blends during 12 week. During week 6, a decrease (linear effect, p = 0.01) in fecal ammonia contents was observed with the increase in the level of protected organic acid blends on d 3 and d 5 of fermentation. Moreover, acetic acid emission decreased linearly (p = 0.02) on d7 of fermentation with the increase in the level of protected organic acid blends. During 12 weeks, linear decrease (p<0.001) in fecal ammonia on d 3 and d 5 and acetic acid content on d 5 of fermentation was observed with the increase in the level of protected organic acid blends. Supplementation of protected organic acid blends linearly increased the longissimus muscle area with the increasing concentration of organic acids. Moreover, color of meat increased (linear effect, quadratic effect, p<0.001, p<0.002 respectively) and firmness of meat showed quadratic effect (p = 0.003) with the inclusion of increasing level of protected organic acid in the diet. During the 6 week, increment in the level of protected organic acid blends decreased (linear effect, p = 0.01) Escherichia coli (E. coli) counts and increased (linear effect, p = 0.004) Lactobacillus counts. During 12-wk of experimental trial, feces from pigs fed diet supplemented with organic acid blends showed linear reduction (p<0.001) of E. coli counts and the tendency of linear increase (p = 0.06) in Lactobacillus count with the increase in the level of organic acid blends. In conclusion, 0.2% protected organic acids blends positively affected growth performance, nutrient digestibility, fecal gas emission and meat quality in finishing pigs without any adverse effects on blood parameters.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.9-14
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• 2018

BACKGROUND: The use of green manure and compost as organic fertilizer may increase crop yield and soil fertility due to improved soil nutrient availability and soil organic matter content (SOM). This study aimed to investigate the effects of hairy vetch (Vicia villosa L.) and compost application on red pepper growth, yield, fruit quality and soil health. METHODS AND RESULTS: The treatments were no fertilizer (CON), chemical fertilizer (CF), hairy vetch (HV), and livestock compost+HV (LC+HV). Red pepper seedlings (70 days old) were transplanted and maintained in experimental plots for 140 days. Plant dry weight, micro- and macronutrient contents of plants and soil chemical properties were determined. All fertilizer treatments significantly increased plant dry weight. Fruit yield was significantly highest with HV treatment. As for nutrient content, plants in HV and LC+HV treatments have significantly higher K and Ca contents than the other treatments. Regarding soil properties, HV and LC+HV application significantly altered the soil chemical properties. Significantly higher SOM was observed in HV and LC+HV treated soils. CONCLUSION: The results of this study suggest that short-term application of hairy vetch and compost is an effective alternative to the conventional chemical fertilizer to increase fruit yield red pepper and improve soil health.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.575-580
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• 2011

The cultivation of once-over harvest pepper cultivars might be very valuable to Korean farmers who still depend on traditional hand-harvesting method. Thus, we conducted this experiment to obtain important information for enhancing the productivity of once-over harvest red pepper fruits by supplying several nutrient-controlling and growth-regulating chemicals, such as $KH_2PO_4$, $SiO_2$ and 2-chloroethylphosphonic acid (ethephon). Adequate fertilization was provided in each treatment plots. In this study, two once-over harvest pepper cultivars, Saengryeg No. 211 and 213 (SR 211 and SR 213), and one regular piecemeal harvest pepper cultivar, Kangryegdaetong (KRDT), were cultivated to evaluate the productivity of pepper fruit as affected by above chemicals. The distribution of macro- and micro-nutrients in pepper fruits among the cultivars were different in term of N, B, Cu, and Fe concentrations. In particular, the concentration of B in SR 213 was about 2 times higher than that in SR 211 and KRDT. However, overall red pepper productivity of SR 211 was markedly higher ($2.91{\sim}3.38Mg\;ha^{-1}$) than that ($1.68{\sim}2.37Mg\;ha^{-1}$) of SR 213. Also, the productivity of matured red pepper was significantly influenced by the treatments of $KH_{2}PO_{4}$, $SiO_2$ and ethephon. The yield indices for matured red pepper fruits were the highest with the treatment of $KH_2PO_4$ or $SiO_2$ with ethephon, which were 113~116% for SR 211 and 147~150% for SR 213. Thus, the applications of $KH_2PO_4$ or $SiO_2$ with ethephon would be suggested to enhance the productivity of matured red pepper fruit.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.441-449
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• 2022

This review is focused on analyzing the limits and shortage of zinc (Zn) for the 2020 Dietary Reference Intakes for Koreans (KDRIs), and provides suggestions for the future establishment of the 2025 KDRIs for Zn. The 2020 KDRIs for Zn have been established to estimate the adequate requirement (EAR), recommended nutrient intakes (RNI), adequate intake (for only 0-5 mon) and tolerable upper intake level (UL). EAR was estimated in 2-stages: the first stage was to construct of the frame of analysis for Zn requirement and the second stage involved a factorial approach by considering the various factors which affect Zn requirement, such as intestinal and urine Zn loss, Zn requirement for growth and development, and Zn absorption rate. For a more precise and accurate establishment of the Zn requirement, we suggest for the following to be considered: 1) considering that Zn is present in minuscule amounts as a trace element in our body, the present values for Zn EAR (as 6-9 mg/d) should be expressed as a decimal point for more accurate DRIs; 2) the frame of analysis for Zn requirement has to be more specifically and should includes the factors which affect Zn requirement; 3) both, the factorial approach and extrapolation method need to be well reviewed and thoroughly understood for establishing precise Zn requirement; 4) currently, human clinical study and balance study (Zn intake, excretion and absorption rate) are limited and more human Zn subject studies are required. All these suggestions are provided to better establish the Zn requirement in the 2025 KDRIs.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.215-220
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• 2011

In order to estimate the inorganic nutrient content in cucumber leaves at respective growth stages under greenhouse conditions, we investigated five cucumber farms practicing a forcing cultivation system with nine-month growth period and another five cucumber farms practicing a semiforcing cultivation system with six-month growth period. The cucumber yield in forcing and semiforcing cultivation systems amounted to 14.8 ton $10a^{-1}$ and 10.7 ton $10a^{-1}$, respectively. Soils between two different cultivation systems showed no significant differences in pH, organic matter contents and exchangeable cation contents during early growth stage, whereas EC, $NO_3$-N and available $P_2O_5$ contents were higher in soils of semiforcing cultivation systems. Suitable soil temperature was well provided by forcing cultivation. The highest NPK contents in leaves were observed in 60~80 days after planting for forcing systems and in 100 days after planting for semiforcing systems. Thereby forcing cultivation systems showed somewhat higher NPK contents. Ca and Mg contents in cucumber leaves did not significantly change during the growth period in forcing systems, while semiforcing systems showed the highest contents of Ca and Mg in 80~100 days after planting. Fe, Mn and Zn contents in leaves also did not significantly change during the growth period, whereas Mn contents were slightly higher in forcing systems due to lower soil pH. B contents in leaves were higher in semiforcing systems because of higher available B contents in soil.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.319-326
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• 2020

BACKGROUND: Measurement equipment was developed for inorganic nutrient concentration inside the hydroponic culture medium with several macro- and micro compositions, and applied for measuring the compositions of conventional medium. METHODS AND RESULTS: Before the equipment development, sonicator and heater were utilized to control temperature around of the module mixing with color reagents and target samples among the inorganic compositions. The measurement module and multi-sampler were also manufactured based on the COMS (Complementary Metal-Oxide Semiconductor) and installed inside the measurement equipment. Concentration of standard solution, value measured by the equipment, standard deviation or measured average value were used for estimating the accuracy and average recall of the equipment. Yamazaki solutions with EC of 0.5, 1.5, and 2.5 dS/m were offered to confirm the equipment accuracy and standard error. CONCLUSION: It was suggested that the developed equipment could be automatically applied for measurement with accuracy of over 96% and standard errors of less than 5% on 12 macro- and micro compositions such as a NO3-N, PO43- or Fe.