• Journal of Ecology and Environment
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• v.35 no.3
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• pp.227-234
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• 2012

Quercus aliena and Q. serrata are both occur as natural vegetation alongside natural freshwater bodies of the southern Korea Peninsula. Q. serrata dominates over Q. aliena as secondary forest vegetation in the present day. In order to explain these natural distributional traits of the oak species, we conducted some experiments with oak seedlings which treated with major important environmental resources, including light, moisture and nutrients, under controlled conditions. We then measured the ecological niche breadths and overlap from 15 eco-morphological characteristics. The ecological niche breadth of Q. aliena and Q. serrata were higher in terms of the nutrient factor applied, but was lower terms of light. The niche breadth of Q. serrata was wider than that of Q. aliena in light and moisture exposure. On the other hand, the niche breadth of Q. aliena was similar with that of Q. serrata in terms of the nutrient factor applied. These results imply that Q. serrata has a broader ecological distribution in over a wider variety of light and moisture environments than that of Q. alien. Ecological niche overlap between two oak species was the widest in terms of the light treatment factor applied, and narrowest in terms of moisture. This response pattern was also verified by cluster and principle component analysis. These results suggest competitive interactions between Q. serrata and Q. aliena seedlings may be higher for light resources than moisture or nutrient resources, and that Q. serrata is more shade tolerant than Q. aliena.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.49-55
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• 1996

Water parsley(Oenanthe javanica(Blume) DC) was raised with varying population density(S) in the laboratory aquarium unit to determine the growth equation. The population density was measure after 7 days. The resultant growth curve was well fit to the equation 1/S = A+B (1/S0) with a high correlation coefficient ($R^2$ = 0.999). The maximum specific absorption rate was $9.011 \times 10^{-5}$ kg $NO_x-N/kg$ water parsley$\cdot$day and $1.31 \times 10^{-5}$ kg $PO_4-P/kg$ water parsley$\cdot$day when the average population density was $2.62 kg/m^2$. The relationship between population density and nutrient absorption rate, the absorption rate of $NO_x-N$ was 5.04~5.24 mg/l$\cdot$day when the population density was $7.51~10.0 $mg/m^2\cdot day$ and the absorption rate of $PO_4-P$ was 0.56~0.78 mg/l$\cdot$day when the population density was 5.02~10.0 $kg/m^2\cdot day$. Taking into account the nutrient absorption rate and growth rate, the population density between $7.0 kg/m^2\cdot day$ and $8.0 kg/m^2 \cdot day$ was selected. The removal rate of nutrient was investigated after 7 days culture. Removal rate of $NO_x-N$ was 95.6~99.95% with initial concentration of 35 mg $NO_x-N/l$, and the removal rate of $PO_4-P$ was also high, indicating 80.24~98.9% with initial concentration of 5.95 mg $PO_x-P/l$.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.229-237
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• 2019

The influence of dietary supplementation with a yeast culture on growth performance, fecal score and nutrient digestibility was evaluated in weaned pigs in a 6-week feeding trial. A total of 50 weaning pigs with an initial average body weight (BW) of $7.46{\pm}1.60kg$ were randomly allotted into 1 of 2 dietary treatments according to the initial BW. There were 5 replicate pens in each treatment with 5 pigs per pen. The dietary treatments were as follows: 1) control, basal diet (CON) and 2) 0.10% yeast culture, basal diet supplemented with 0.1% yeast culture (YC). The average daily feed intake was significantly improved with the dietary supplementation of the yeast culture compared with the control during phases 1 and 3. Overall (0 to 6 weeks), dietary supplementation with the 0.1% yeast culture had a significant effect on the feed conversion ratio (FCR). There was no significant difference in the fecal score between the CON and YC dietary treatments. In addition, no difference in the apparent total tract digestibility was observed between the CON and YC dietary treatments. Collectively, the results of this study indicate that dietary supplementation of 0.1% yeast only improved the feed intake of weaning pigs; however, yeast culture supplementation did not affect the average daily gain, feed efficiency, total tract digestibility of dry matter, and nitrogen and energy levels as well as the fecal scores.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.531-537
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• 2022

This study evaluated the effects of dehulled lupin kernel (DLK) supplementation on growth performance, nutrient digestibility, blood urea nitrogen (BUN) and creatinine, fecal microbiota and fecal noxious gas emission in growing pigs. A total of 108 growing pigs (Landrace × Yorkshire × Duroc) with an average initial body weight (IBW) of 24.49 ± 3.2 kg were allocated to one of three dietary treatments (5, 10, and 20 % DLK) according to sex and BW in a randomized complete block design for 6 wk. Each dietary treatment consisted of 9 replication pens with 4 pigs per pen (2 gilts and 2 borrows). The results show that there were no significant differences in growth performance and nutrient digestibility among the treatments (p > 0.05). However, pigs fed the DLK20 diet had a higher BUN compared with those fed the DLK10 diet (p < 0.05). No effects were observed on the fecal microbiota and fecal noxious gas emission among the treatments. In conclusion, the inclusion of 20% DLK had no adverse effects on the performance in growing pigs.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.243-249
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• 2022

Background: Mixed breeding herb Viola collina Besser, which produces both chasmogamous and cleistogamous flower, has limited habitats under closed canopy and short and early flowering timing, making it relatively more vulnerable to climate change. To better understand the effect of light and nutrient on the flower formation and vegetative growth of V. collina, a mesocosm experiment was conducted. Two-by-two factorial treatments of two light conditions (100% and 60% of natural light) and two fertilizer treatment conditions (fertilized and not fertilized) were applied in the mesocosm experiment. Results: The number of flowers, including chamogamous and cleistogamous flowers, was highest (5.65/pot) under 60% light and fertilized condition and lowest (1.41/pot) under 100% light and not-fertilized condition. However, above ground vegetative growth was highest (2.89 g/pot) under 100% light and fertilized condition and lowest (2.38 g/pot) under 60% light and not-fertilized condition. Above ground biomass to belowground biomass ratio was highest (1.50) under 60% light and fertilized condition and lowest (1.26) under 100% light and fertilized condition. Conclusions: This study showed that high light and nutrient are responsible for the vegetative growth, though the effect of fertilizer was reduced due to allocation and retainment of nutrients. In addition, the low light is necessary to make flowers, especially chasmogamous flowers.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.185-192
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• 2022

The purpose of this study was to investigate the effects of condensed molasses fermentation solubles (CMS) on the growth performance, nutrient digestibility, and backfat thickness of growing pigs. In an eight-week trial, a total of 120 cross-bred ([Landrace × Yorkshire]× Duroc) growing pigs with an average initial body weight (BW) of 25.84 ± 1.60 kg were used. The pigs were randomly assigned to one of two dietary treatments based on body weight and sex. The dietary treatments were as follows: CON - corn-soybean meal-based basal diet (CON) + 2% molasses; and TRT1 - CON + 2% CMS. Each treatment had 12 replicates with five pigs (three gilts and two castrated barrows) per pen. Though there were no significant differences observed in terms of the growth performance and nutrient digestibility (p < 0.05), the backfat thickness in pigs fed 2% CMS tended to increase in week 4 (p < 0.1). Thus, 2% CMS could be optimal to replace molasses given that it does not exert any adverse effects on the performance of growing pigs.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.152-158
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• 2023

This study was conducted to evaluate the effects on soil chemical properties and plant growth after applying soldier fly compost (SFC). Treatments were as follows. No fertilizer (NF), control, SFC1 (SFC 250 kg/10a), SFC2 (SFC 500 kg/10a) and SFC3 (SFC 1,000 kg/10a). As compared to control in the pot test, organic matter (OM) and exchangeable sodium (Ex-Na) of SFC3 treatment were increased, and growth and nutrient uptake of young radish were not significantly different. Correlation coefficient between soil chemical factors like total nitrogen (T-N), OM, and CEC and uptake of nitrogen (N) and phosphorus (P) was significantly positive (p≤0.05). Compared to control in the field test, electrical conductivity, T-N, OM, Av.-P₂O₅, and CEC was increased, and lettuce growth was not significantly different. Correlation coefficient between application amount of SFC and T-N, OM, and Av.-P₂O₅ was significant positively (p≤0.05). These results indicated that the application of SFC improved nutrient availability of soil by increasing OM and CEC.

• Journal of Digestive Cancer Research
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• v.1 no.2
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• pp.82-88
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• 2013

Cancer is the first leading cause of death in Korea and the second leading cause of death in the USA. There is extensive research into prevention of cancer and the support of oncology patients with diet or dietary supplements. In vitro and in vivo animal studies have indicated that antioxidants, including beta-carotene, alpha-tocopherol, and ascorbic acid, can yield anti-cancer effects in addition to providing protection against oxidative damage. Although many observational studies have shown that consuming fruits and vegetables can reduce the risk of some cancers, the results of several large-scale human intervention trials testing the benefits of a single or combined higher-dose of individual micronutrients have been inconsistent. Cancer can cause profound metabolic and physiological changes which may affect patients' nutrient requirements. Although the optimal route of nutrient delivery is through diet, cancer patients often suffer symptoms that disrupt their food intake, including anorexia, premature satiety, altered taste and smell, and changes in bowel mobility. In particular, micronutrient deficits can slow postoperative healing, contribute to depression symptoms, and decrease immune competence. Cancer patients are generally motivated to take dietary supplements to improve responses to treatment and quality of life. The Physician's Health Study II (PHS II) randomized controlled trial reported recently that daily multivitamin supplementation significantly, albeit modestly, reduced the risk of total cancer. Although evidence of multivitamin use benefits is limited in cancer patients, taking dietary supplements with constituents in the range of the recommended daily allowance according to the Dietary Reference Intake (DRI) recommendation is generally considered to be safe.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.53-61
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• 2024

A total of 180 21-day-old weaning pigs ([Yorkshire × Landrace] × Duroc) with an initial body weight of 6.44 ± 0.01 kg were randomly assigned to 9 treatments for evaluating the effects of replacing dietary inorganic copper (Cu) and zinc (Zn) with glycine (Gly) or methionine (Met)-chelated Cu and Zn on growth performance and nutrient digestibility. The experimental period was 35 days. There were four replicated pens per treatment, with five pigs (three males and two females) per pen. Dietary treatments consisted of a basal diet (CON), in which the sources of Cu and Zn were in inorganic form. The inorganic Cu and Zn in the basal diet were replaced by glycine-chelated (GC) and methionine-chelated (MC) Cu and Zn by 30, 50, 70, or 100% to form the GC1, GC2, GC3, GC4, or MC1, MC2, MC3, MC4 groups. The 100% replacement of dietary inorganic Cu and Zn with GC or MC increased (p < 0.05) average daily gain, average daily feed intake, and gain-to-feed ratio. The complete replacement of dietary inorganic Cu and Zn with GC or MC led to enhanced (p < 0.05) digestibility of dry matter, nitrogen, Cu and Zn. Thus, the replacement of inorganic Cu and Zn with GC or MC can improve the growth efficiency and nutrient utilization of weaning pigs.