• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.130-135
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• 1997

Tomatoes are flooded differently 0, 5, 10 and 15cm, according to the developing stages such as flowering stage under the condition of greenhouse. Along with this, they are treated according to the time condition such as 6, 12, 24, 48 and 120 hours. The results obtained are summarized as follows. Plant height decreased in the depth of $0{\sim}10cm$ for over 48 hours, in the depth of 15cm for over 24 hours. Number of leaves was the same as in control, and it decreased over. Number of flowers and fruit setting of individuals decreased conspicuously according as the depth and the hours got greater and longer. Adventitious root occurred remarkably in the depth of $0{\sim}10cm$, for over 24 hours and in the depth of 15cm, 12 hours. Epinastic curvature increased greatly as the depth and the hours got greater and longer. Diffusion resistance of stomata cell increased as the depth and the hours got greater and longer. Diseases occurred conspicuously as the hours of flooding got longer rather than as the depth greater. The preventing of diseases caused by insecticide was observed, but it was not greater than in the seedling and transplanting stage. Fertilization was effective in the case of increasing the weight of shoot. Number of fruits per plant did not decrease in the depth of 0cm up to 24 hours, but decreased on the deeper level of flooding and increased as the hours got longer. Moreover with the exception of 120 hours per respective depth of the treatment, average weight of a fruit got greater as the depth and the hours got greater and longer. In the case of epinastic curvature and diffusion resistance, there was negative correlation between all the other investigated characters and positive correlation between weight of a fruits and average weight of a fruit.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.475-481
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• 2006

Purpose : As the prevalence of childhood obesity is increasing, hypertension, hyperlipidemia, insulin resistance and diabetes mellitus have become problems. High homocysteine levels and low vitamin $B_{12}$ supplementation are acknowledged to have a role in coronary artery disease, but there are few studies on homocysteine, insulin and vitamin $B_{12}$ levels in obese children. We aimed to study whether homocysteine, insulin, vitamin $B_{12}$, folic acid levels could have any difference and relation in obese children. Methods : The disease group consisted of 27 children from 8 to 11 years old, whose obesity index was over 130. The control group consisted of 30 healthy children of the same age group. Obesity index and body mass index were calculated by height and body weight of the children, and their systolic and diastolic blood pressures at resting state were checked. Total cholesterol, triglyceride, homocysteine, insulin, vitamin $B_{12}$, folic acid levels were studied after 10 hours of fasting. Intracellular fluid, extracellular fluid, protein, mineral, muscle mass, lean body fat, fat mass and fat percentages were checked by bioelectrical impedance. Results : Homocysteine levels were higher in obese children($8.1{\pm}2.1{\mu}mol/mL$ vs. $4.9{\pm}1.0{\mu}mol/mL$). Insulin levels were also higher in obese children($26.8{\pm}11.2{\mu}IU/mL$ vs. $12.5{\pm}5.24{\mu}IUl/mL$). Vitamin $B_{12}$ was lower in obese children($798.6{\pm}174.3pg/mL$ vs. $967.8{\pm}405.0pg/mL$). But there was not a difference in the folic acid levels between the two groups. In obese children, systolic blood pressure (r=0.535), triglyceride(r=0.517), total cholesterol(r=0.408), folic acid(r=0.408), vitamin $B_{12}$(r=0.338) and abdomoanl fat %(r=0.306) had a positive correlation. Conclusion : We found definite differences of insulin, homocysteine, and vitamin $B_{12}$ plasma levels in obese children, but we need more study to use those parameters as risk factors of metabolic syndrome in pediatric obese patients.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.145-156
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• 1996

The effects of priming with different polyethylene glycol (PEG 6, 000) solutions on the germination, emergence characteristics and early plant growth in rice, barley and wheat were investigated. Rice, barley and wheat seeds were subjected to various priming conditions of osmotic potentials (-0. 75, -1.00 and -1.50 MPa) of PEG, and incubation period were 5 days at 25, 20, 2$0^{\circ}C$, respectively. The percentage of water absorption was highest in barely, and lowest in rice, and all the treatments enhanced water absorption in barley, but showed no significant effects in rice and wheat. Respiration quotient was lower than none PEG treatment seeds, and those of barley and wheat were higher than rice regardless of PEG concentration, and that of rice increased with high PEG concentration. Total germination percentage of osmoconditioning seeds with PEG was higher than that of none treatment seed, and those of barley and wheat were significant. The artificially deteriorated seeds with PEG treatment seeds after ageing treatment could recover to nearly the same germination level as that of the control seeds. The effects of coating polymer were higher than osmoconditioning with PEG, and germination characteristics in rice showed varietal difference at PVP and waterlock at recoated seeds after PEG treatment. Osmoconditioning with PEG reduced mean germination and emergence time, but there was no difference among PEG concentrations. The plant height of PEG treaed seed in rice was taller and those of barely and wheat showed varietal difference, and those of polymer-coated seed after PEG treatment were different among the polymers. The dry weight of PEG treatment were different among the crops, and those were increased with the high PEG concentration. The emergence percentage of PEG-treated seed were higher than none-treated seed, and those were decreased with the increased PEG concentration, and the highest emergence percentage of rice, barley and wheat were 90, 50 and 50% soil moisture content, respectively. The time to emergence in rice was longer than barley and wheat, and those in rice was shortened in high soil moisture content, and barley and wheat were shortened in low soil moisture content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.420-428
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• 1996

This study was conducted to investigate the response of growth and yield of rice under five different cultural methods, machine transplanting(MTNT), puddled drill seeding (PDSNT), drill seeding on soil surface (DSNT) , broadcasting on soil surface (BSNT) under no-tillage paddy condition and conventional machine transplanting(MTT) in Jeonbuk series(siltyloam soil) from 1993 to 1995. Soil hardness was higher in no-tillage soil and increased with highly difference between tillaged and no-tillage soil with deeper soil depth. Bulk density was heavier in no-tillage soil and porosity was higher in tilled soil than that of the control. The rate of effective tiller was higher in MTT, following MTNT, PDSNT, DSNT and BSNT. Weed occurrence was more serious in no-tillage soil, than that of tillaged soil. The rate of lower internode length was lower in DSNT and BSNT and was similar with MTT in PDSNT and MTNT. Height of center gravity in terms of lodging tolerance was lower in direct seeding than in machine transplanting. Depth of buried culm was shorter in no-tillage soil, especially in DSNT and BSNT. Total amount of root was higher in MTT, following MTNT, PDSNT, BSNT and BSNT and the distribution rate of root in shallower soil layer was higher in no-tillage soil, especially in BSNT and DSNT. Field lodging occured highly in BSNT, following DSNA, PDSNT and MTNT with high lodging scale in DSNT and BSNT. Panicle number per unit land square meter was the highest in MTT and the least in BSNT. Ripened grain ratio was low in BSNT and DSNT due to heavy lodging. Yield of milled rice was 93% in PDSNT, 87% in DSNT, 81% in BSNT and 96% in MTNT, compared with 534kg /10a in MTT.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.113-123
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• 2020

Global climatic change and increasing climatic instability threaten crop productivity. Due to climatic change, drought stress is occurring more frequently in crop fields. In this study, we investigated the effect of treatment with hydrogen peroxide (H₂O₂) before leaf development on the growth and yield of sorghum for minimizing the damage of crops to drought. To assess the effect of H₂O₂ on the growth of sorghum plant, 10 mM H₂O₂ was used to treat sorghum leaves at the 3-leaf stage during growth in field conditions. Plant height, stem diameter, leaf length, and leaf width were increased by 7.6%, 9.6%, 8.3% and 11.5%, respectively. SPAD value, chlorophyll fluorescence (Fv/Fm), photosynthetic rate, stomatal conductance, and transpiration rate were increased by 3.0%, 4.9%, 26.0%, 23.4% and 12.7%, respectively. The amount of H₂O₂ in the leaf tissue of sorghum plant treated with 10 mM H₂O₂ was 0.7% of the applied amount after 1 hour. The level increased to approximately 1.0% after 6 hours. The highest antioxidant activity measured by the Oxygen Radical Absorbance Capacity assay was 847.3 µmol·g^-1 at 6 hour after treatment. However, in the well-watered condition, the concentration of H₂O₂ in the plant treated by the foliar application of H₂O₂ was 227.8 µmol·g^-1 higher than that of the untreated control. H₂O₂ treatment improved all the yield components and yield-related factors. Panicle length, plant dry weight, panicle weight, seed weight per plant, seed weight per unit area, and thousand seed weight were increased by 8.8%, 18.0%, 24.4%, 24.7%, 29.9% and 7.1%, respectively. Proteomic analysis showed that H₂O₂ treatment in sorghum increased the tolerance to drought stress and maintained growth and yield by ameliorating oxidative stress.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.325-332
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• 1999

A manure management plan is important for all dairy operations. This experiment was conducted to determine the effect of different nitrogen(N) application rates of liquid cattle manure on the forage quality, N recovery, and total forage yields of corn-oats cropping system and soil properties at the National Livestock Research Institute, RDA, Suweon in 1997. Eight treatments consisting of no fertilizer, chemical fertilizer $320kg\;N\;ha^{-1}$ as urea, the continuous applications of 320, 640 and $960kg\;N\;ha^{-1}$ as liquid cattle manure(LCM), the residual effects of 200, 400 and $600kg\;N\;ha^{-1}$ as liquid cattle manure were arranged in a randomized complete block design with three replications. Mean plant height of fall sown oats was 70 and 61cm at the continuous application and the residual effect plots, respectively. Mean dry matter percent of fall sown oats at the residual effect plots was higher by 0.9% than that of oats at the continuous application plots, but there were no differences among all treatments. Mean crude protein(CP), acid detergent fiber(ADF), and neutral detergent fiber (NDF) contents of fall sown oats at the continuous application plots were higher by 1.0, 1.6, and 3.1%, respectively, than those of the residual effect plots. Also, there were significant differences among treatments (P<0.05). Total forage dry matter yields of corn and oats cropping system were ranged from 11,365 to $25,668kg\;ha^{-1}$ among the treatments. The yield was orderly ranked as LCM $960kg\;N\;ha^{-1}$ > LCM $600kg\;N\;ha^{-1}$ > LCM $640kg\;N\;ha^{-1}$ > LCM $400kg\;N\;ha^{-1}$ (P<0.05). Compared with the control, manurial value(MV) was 158 and 139% for the plot of the LCM $960kg\;N\;ha^{-1}$ and that of the LCM $600kg\;N\;ha^{-1}$, respectively. N recovery percent of fall sown oats was the highest at the plot of the LCM $200kg\;N\;ha^{-1}$ by 50%, and then was higher in order of the LCM $400kg\;N\;ha^{-1}$, LCM $600kg\;N\;ha^{-1}$, and LCM $320kg\;N\;ha^{-1}$. Contents of exchangeable cation in the soil of the residual effect plots was higher than that of the continuous application plots. These results suggest that the LCM $600kg\;N\;ha^{-1}$ may be the most effective in total forage dry matter yields, manurial value, N recovery, and utilizing liquid manure N under the corn and oats double cropping system.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.287-295
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• 2016

Involuntary physical activity induced by the avoidance of electrical shock leads to improved endurance exercise capacity in animals. However, it remains unknown whether voluntary stand-up physical activity (SPA) without forced simulating factors improves endurance exercise capacity in animals. We examined the effects of SPA on body weight, cardiac function, and endurance exercise capacity for 12 weeks. Twelve male Sprague-Dawley rats (aged 8 weeks, n=6 per group) were randomly assigned to a control group (CON) or a voluntary SPA group. The rats were induced to perform voluntary SPA (lifting a load equal to their body weight), while the food height (18.0 cm) in cages was increased progressively by 3.5 every 4 weeks until it reached 28.5 cm for 12 weeks. The SPA group showed a lower body weight compared to the CON group, but voluntary SPA did not affect the skeletal muscle and heart weights, food intake, and echocardiography results. Although the SPA group showed higher grip strength, running time, and distance compared to the CON group, the level of irisin, corticosterone, genetic expression of mitochondrial biogenesis, and nuclei numbers were not affected. These findings show that voluntary SPA without any forced stimuli in rats can effectively reduce body weight and enhance endurance exercise capacity, suggesting that it may be an important alternative strategy to enhance endurance exercise capacity.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.65-69
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• 2009

Purpose: Recently incidence of VDT syndrome has gradually increased as extensive use of computers. VDT syndrome reported by VDT workers include musculoskeletal disorder, neuropsychiatric disoders and eye symptoms such as eye strain, tired eyes, irritation and blurred vision. The environmental factors of VDT syndrome include electromagnetic waves, size, brightness and lighting of computer screen, height of a monitor and a worktable, working hours, kind of task, distance between screen and workers, indoor humidity and temperature, indoor air contamination and ventilation. In this study, we investigated the environmental factors related to body symptoms and health effects included in VDT syndrome. Methods: Study subjects were total 120 persons (54 male, 66 female) with age from 19 to 28. We surveyed the body symptoms and physical discomfort when doing an activity in a short distance such as reading book or paper, computer work. The questionnaire included main body symptoms, self-consciousness symptoms of eye, satisfaction of working environment, pain of the wrist when using keyboard and mouse. Results: Most of people (70%) felt physical pain from long time work of computer, paper, electrical apparatus. They mainly complained pain of neck and low back (57.1%), eye (45.2%) and head (31%). With the environmental factors, 78.3% of the subjects complaint pain of eye from inappropriate illumination. Most of the symptoms included 'eye fatigue'(38.3%), 'dryness of eye'(31.9%) and 'blurred vision'(23.7%). Subjects in this study complained discomfort of their chairs and most of them experienced pain in the wrist when using keyboard or mouse. Conclusions: When people use electrical apparatus or work with paper, people would get their eye fatigue and feeling of physical fatigue because of not harmonizing various environmental factors such as light, space, posture, worktable with theirselves. Therefore, workers should develop preventive method such as self-control of adequate break time to avoid fatigue while VDT work. Work environment should be changed to ergonomic design for optimal visual environment to prevent musculoskeletal disorder through constant research.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1119-1126
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• 2009

Purpose:This study compares the maternal characteristics and birth outcomes of infants of Asian immigrant mothers from developing countries with those of the infants of Korean mothers. Methods:In this multicenter and retrospective study, Asian immigrant women who had delivered between January 2005 and June 2008 were enrolled from9 Medical Centers. In all, 333 births to Asian immigrant women from developing countries (Asian-Korean infants) were included in this study. In addition, sex-, birth year-, and gestational age-matched 333 neonates born to Korean mothers were selected as the control group (Korean infants). On the basis of the hospital data, we investigated the nationality, age, and medical history of the mothers and compared the incidence of congenital infection, Apgar score, weight, height, and head circumference of Asian-Korean infants with those of the Korean infants. Results:The average maternal age of Asian women from developing countries at birth term was 26.7 years, which was significantly lower than that of Korean women (30.8 years, P<0.05). The birth weight of Asian-Korean infants (2,869 g) was significantly smaller than that of Korean infants (2,995 g, P<0.05). There was a significant difference in the incidence of congenital syphilis infection between the Asian-Korean infants and Korean infants (5 cases vs. 0 case, P<0.05). Conclusion:There were significant differences in the perinatal outcomes between the Korean and Asian-Korean infants. A multicenter large-scaled study should be performed to analyze the perinatal outcomes of Asian-Korean infants.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.31-43
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• 1997

This study was carried out to investigate classfication of weedy rice (Oryza sativa) based on isozymes esterase and peroxidase, growth and developmental difference of weedy rices and rices grown under dry and water condition, and weedy rice control and tolerant difference of weedy rices in various herbicides using weedy rices collected from thirteen strains of Chonnam, one Chonbuk, two Kyeongki and two rice cultivars. 1. The collected weedy rices were classified into three groups based on isozyme esterase and peroxidase using polyacrylamide gel electrophoresis(PAGE) method. The classified groups were not same each other. 2. Plant height was taller in collected weedy rices than rice cultivars at 18 days after seeding under dry and water conditions, but number of leaves, shoot fresh weight, root fresh weight and root length were not significantly different between collected weedy rices and rice cultivars. In addition, growths of collected weedy rices were greater in dry- than water-condition. 3. After thiobencarb(S-4-chlorobenzyl diethythiocarbamate), molinate(S-ethyl hexahydro-1H-azepine-1-carbothioate) and oxadiazon(5-tert-butyl-3(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2-one) were applied at 6 days before seeding, the weedy rices controlled 100% by thiobencarb at 2.1kg ai/ha and 024kg ai/ha oxadiazon treatment but controlled 26% to 67% by molinate at 6.5kg ai/ha. Rice due to the herbicides was injured severely(25% to 100%) in flood condition at time of rice seeding after oxadiazon at 0.48kg ai/ha and 2.1kg ai/ha thiobencarb application, except for molinate which injured rice slightly(4% to 13%) in drain condition. The collected weedy rices to all experimented herbicides showed slight intraspecific variations. The intraspecific variations of weedy rices decreased in the order of thiobencarb>molinate>oxadiazon.