• Journal of Ecology and Environment
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• v.29 no.6
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• pp.559-563
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• 2006

This work was investigated the effects of the elevated $CO_2$ and Pb contamination on the growth of Pinus densiflora. Two-years pine trees were planted in Pb-contaminated soils (500 mg/kg-soil) and uncontaminated soils, and cultivated for 3 months in the growth chamber where $CO_2$ concentration was controlled at 380 or 760 ppmv. The growth of P. densiflora were comparatively analyzed in 4 kinds of soil samples (CA : $CO_2$ 380 ppmv + Pb 0 mg/kg, CB : $CO_2$ 380 ppmv + Pb 500 mg/kg, EA : $CO_2$ 760 PPmv + Pb 0 mg/kg, EB : $CO_2$ 760 ppmv + Pb 500 mg/kg). It was measured the growth changes of the p. densiflora caused by $CO_2$ concentration and Pb contamination. The growth of P. densiflora was remarkably inhibited in the Pb-contaminated soil, although the biomass and the root elongations were not significantly affected by the elevated $CO_2$. These results suggested that the growth of p. densiflora was sensitively influenced by Pb contamination rather than $CO_2$ concentration. Compared to the initial soil, total Pb concentration in the soil samples was decreased at 760 ppmv $CO_2$ as well as at 380 ppmv $CO_2$ after 3 months. The accumulation of Pb in the roots at 760 ppmv $CO_2$ was two-fold of that at 380 ppmv $CO_2$, indicating that Pb bioavailability in the root of p. densiflora might be affected by the elevated $CO_2$.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.243-251
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• 2011

BACKGROUND: Gypsum($CaSO_4{\cdot}2H_2O$) is known as an ideal amendment to improve soil quality of the reclaimed coastal land. Since gypsum has very high concentration of electron acceptor like ${SO_4}^{2-}$, its application might be effective on reducing $CH_4$ emission during rice cultivation, but its effect has not been studied well. METHODS AND RESULTS: The effect of gypsum on $CH_4$ emission and rice growth characteristics was studied by pot test, which was packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Chemical-grade gypsum was applied in two soils having EC 2.25 and 9.48 dS/m at rates of 0, 0.5, 1.0 and 2.0%(wt/wt). $CH_4$ emission was characterized a week interval by closed chamber method during rice cultivation. $CH_4$ emission rate was significantly decreased with increasing salt accumulation and gypsum application levels. With increasing gypsum application, dissolved ${SO_4}^{2-}$ concentration in the leachate water was significantly increased, which might have suppressed $CH_4$ production in soil. Total $CH_4$ flux was dramatically decreased with increasing gypsum application. In contrast, rice yield was increased with increasing gypsum application and then achieved maximum productivity at 1.0% gypsum application in two soils. CONCLUSION(s): Gypsum is a very good soil amendment to suppress $CH_4$ emission in reclaimed coastal paddy soils, and improve rice productivity and soil properties. The optimum application level of gypsum is assumed at ca. 1% to improve soil productivity with reducing effectively $CH_4$ emission during rice cultivation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.2
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• pp.108-116
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• 2023

Recently, the concentration of fine dust causative substances (NOx, VOC, etc.) in the atmosphere has increased, resulting in high concentrations of tropospheric ozone (O3) and increased damage to crops. This study aimed to analyze the impact of high concentrations of ozone gas on the initial growth of rice plants and investigate the relationship between ozone damage resistance and anthocyanin biosynthesis. To achieve this, rice plants were exposed to elevated levels of ozone g as using an ozone chamber, and subsequent measurements were taken to assess changes in growth, the percentage of damaged leaves, and the anthocyanin content. The results revealed that varieties with a higher proportion of damaged leaves exhibited a relative increase in anthocyanin biosynthesis following ozone exposure. Notably, detrimental effects on growth, such as decreased biomass, were mitigated. Additionally, Anthocyanin biosynthesis genes in rice were listed by selecting homologous genes from Arabidopsis and Maize. The expression of OsF3H2, OsFLS1 and OsLDOX3 was induced during ozone treatment. This result is expected to contribute to the study of the protection mechanism of plants from ozone damage.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.363-375
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• 2016

Potentilla kleiniana is a perennial herb beloning to Rosaceae family. Herein we investigated the effect of light intensity, light quality and chemical elicitor on plant growth and the accumulation of bioactive compounds in P. kleiniana. After 60 days of cultivation under different shading level [0% (200 μmol·m⁻²·s⁻¹), 35% (95 μmol·m⁻²·s⁻¹), 55% (65 μmol·m⁻²·s⁻¹), 75% (40 μmol·m⁻²·s⁻¹)] in the greenhouse, chlorophyll and carotenoid content were the highest under 35% treatment, however, plant height, leaf number and biomass were the highest under non-shading. As a result of cultivation among strong light condition as a control, florescence and three mixture light sources [red:white:blue (RWB) = 8:1:1, red:blue (RB) = 8:2, red:green:blue (RGB) = 8:1:1] as treatments in plant growth chamber (25 ± 2℃, 185 ± 3 μmol·m⁻²·s⁻¹), growth, biomass, chlorophyll content low difference between total phenolic compouds and flavonoid content were higher under RWB treatment. DPPH radical elimination ability was the highest under all treatments especially florescence and RGB treatment except control. As a result of treating chemical elicitor [salicylic acid (SA), methyl jasmonate (MeJA)] concentration (0, 50, 100, 200 μM) respectively, plant height, petiole diameter and biomass were higher under non-treatment, MeJA 50 μM. It was investigated that fresh weight and dry weight under MeJA 50 μM treatment were especially a little high. Total phenolic compounds and flavonoid content of SA 50 μM treatment was the highest but DPPH radical elimination ability was significantly the highest under MeJA 200 μM (88.65%) and MeJA 50 μM (87.84%) treatment. Thus, this study suggested that we determined optimal shading and light quality in the greenhouse and plant growth chamber also confirmed bioactive compound content, antioxidant ratio increase according to different chemical elicitation concentration.

• Progress in Medical Physics
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• v.11 no.2
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• pp.123-130
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• 2000

The performance of an electrometer directly affects on the accuracy and precision in radiation dosimetry. This study is to list of the quality control for maintaining performance and to perform evaluation tests of an electrometer. Performance tests selected include proper polarizing voltages, warm-up and equalization time, leakages, long-term stability, linearity, and effect of ambient conditions. An electrometer connected with a rigid stem ionization chamber was evaluated with a Strontium-90 check device. Bias voltage was measured directly on the input socket. Equalization time is the time required for reaching threshold of charged state after the power is on or the bias voltage is changed. Pre- and post-signal leakages are defined as the accumulation of signal with no exposure and after exposure, respectively. Over three months period, the electrometer's long-term stability was measured by comparison of the temperature-pressure corrected readings. Linearity was expressed as the deviation of readings from multiple short exposures from one continuous exposure. Effect of ambient conditions was expressed as the zero drift of the electrometer over 17-34$^{\circ}C$ temperature ranges. For two nominal values, 300 and 500 volts, measured voltages were lower by 2.5 and 5.8%, respectively. The warm-up time, 20 minutes, was longer than the lamp time by 9 minutes and the equalization time was less than 1 minute. Without exposure, the zero-drift was 0.002 scale-unit in 15 minutes and the leakage after 10 minutes exposure was minimal. The IQ-4 was stable over 99.4% for three-month periods. Deviation from the linearity was 0.9% for measurement scale, 0.000-9.991. Over 17-34$^{\circ}C$ temperature range, the zero-drift was minimal, less than 0.2%. For a clinically-used electrometer, a list for the basic peformance evaluations is proposed. By running this program, the measurement error using an electrometer can be reduced and in turn the improvement in accuracy and precision of radiation dosimetry can be achieved.

• The Journal of Internal Korean Medicine
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• v.31 no.4
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• pp.792-812
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• 2010

In the 18th century, Xu Lingtai (徐靈胎) and Yoshimasu Todo (吉益東洞) were famous doctors advocating ancient medicine, though they lived in different countries, China and Japan. We compared their major books, analyzed their academic thoughts and then took conclusions as below. 1. The first, for instance "Classified Prescriptions of Treatise on Cold Damage Diseases, 傷寒論類方" and "Classified Assemblage of Prescriptions, 類聚方". Based on essential thought that a prescription and a syndrome should correspond, these books arranged and classified the Zhang Zhongjing (張仲景)'s texts."Classified Prescriptions of Treatise on Cold Damage Diseases", based on the thought that principles, methods, formulas and medicinals (理法方藥) were integrated in prescriptions, tried to find out the implicit treatment rules in prescriptions and syndromes through analyzing "Treatise on Cold Damage Diseases, 傷寒論". On the other hand, because Classified Assemblage of Prescriptions focused on the syndromes of ancient prescriptions (古方), it classified and collected the related texts of Treatise on Cold Damage Diseases and "Synopsis of Prescriptions of the Golden Chamber, 금궤요략", and then suggested only simple instructions on how to prescribe medicine. So in this book, the trend of experience was clear. 2. The second, there is "100 Kinds Records from Shennong's Classic of Materia Medica, 神農本草經百種錄" and "Description work of herbal pharmacology comprised of excerpts from Shanhanlun and medical experiences, 藥徵". Though both of these books are professional oriental pharmacology publications that advocate reactionism, there were remarkable differences in writing style between them. "Description work of herbal pharmacology comprised of excerpts from Shanhanlun and medical experiences" was based on "Treat on Cold Damage Diseases" and "Synopsis of Prescriptions of the Golden Chamber", just explained the effects of medications and discussed 'matter of course (所當然)', but not discussed 'the reason why (所以然)'. In explaining style of syndromes, it confirmed through research, and emphasized the inductive method. On the other hand, "100 Kinds Records from Shennong's Classic of Materia Medica based on "Shennong's Classic of Materia Medica, 神農本草經", explained the nature of medications and discussed 'the reason why (所以然)'. In explaining style of syndromes, it annotated and explained, and emphasized the process of reasoning. 3. The third, there is "Discuss the Headwaters of Medicine, 醫學源流論" and Severance of Medical evils, 醫斷". Aiming the then medical theories fallen in confused state, these books brought order out of chaos, clarified the categories of medical research, and emphasized the scientific method that could put theories into practice and verify them. The difference is that "Severance of Medical Evils" researched only macroscopic viewable clinical phenomena, and even denied the existence of names of diseases and etiological causes. Thus, it emphasized the accumulation of experiences, laid emphasis on "watching and realizing (目認)", and "understand and taking in (解悟)". Discuss the Headwaters of Medicine extremely emphasized the research of 'something not occuring (未然)', that is to say, induced notions of a disease from observing clinical phenomena, furthermore based on these, predicted the 'something not occuring (未然)' and emphasized researching 'the reason why (所以然)'. As regards how they deal with the traditional theories and post-Zhang Zhongjing's medicines, "Severance of Medical evils" took completely denying attitudes. In case of "Discuss the Headwaters of Medicine", it could be used reasonably through specific situation and detailed analysis. Collectively speaking, there were some differences between medical theories of Xu Lingtai and Yoshimasu Todo. Actually, these differences were whether he tried to research the essence of disease, whether he tried to consider it rationally, and how he treated various opinions occurring in the theories of traditional medicine and clinical experience.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1094-1099
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• 2012

This study investigated the effect of a long-term high-fat diet on energy metabolic substrate utilization in resting rats in order to revalue source fat energy efficiency during a high-fat diet and its effect on energy expenditure and body fat accumulation. Sprague-Dawley male rats at 4 weeks of age were bought from Orient Bio Con. The rats were divided into a control (CON) group and a high-fat diet (HF) group. Rats ate a high-fat diet (w/w 40%, kcal/kcal 64.9%) ad libitum for 5 weeks. Food intake and body weight were measured every day at 09:00 throughout the experimental period. Energy expenditure was measured using an animal energy metabolism chamber after 4 weeks. The final body weight did not change between the CON and HF groups, but caloric intake was significantly higher in the HF group than in the CON group (p<0.05). There was no difference between the groups in oxygen uptake, however carbon dioxide production was significantly higher in the HF group. Also, the respiratory exchange ratio was higher in the HF group. Carbohydrate oxidation was lower in the HF group than in the CON group, but fat oxidation in the HF group was greater. These results mean that energy substrate oxidation at rest is affected by diet composition, especially dietary fat content. Abdominal fat fad weights were significantly higher by 33% in the HF group than in the CON group even though the calorie intake in the HF group was higher by 6%. These results suggested that the dietary fat calorie value might have a higher Atwater value of 9 kcal/g, which mean that dietary fat calorie values could be reconsidered in body weight control scenarios such as which the obese or weight class athletes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.3
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• pp.198-206
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• 1995

Baled silage making(BS) of selected forage crops was discussed during 1991-1993, to determine the best cutting time of the plants for BS production, BS yields and silage quality. Seven species of forage crops and pasture grasses(rye, barley, spring oat, Italian ryegrass, orchardgrass, alfalfa and grass-legume pasture mixtures) were harvested at different stage of growth from young plant to physiological maturity, and baled in a self constructed square baling chamber. Each bales, measured 90cm length, 60cm width and 50cm height, were wrapped with 0.05mrn thick polyethylene plastic film, and stored in stack silo. Each bales were weighed between 15-20 kg in dry matter basis. The effects of pre wilting and formic acid addition on the silage quality of young plant materials, which contained high water concentration, was also evaluated during the experiment. Rye plant including of barley and spring oat were evaluated as a good materials for baled silage making. Fodder rye produced high quality BS with a value of silage quality point 84(Flieg's point) when the plant harvested at stage of greatest dry matter accumulation by 12.64 tonha. The best quality BS of barley was obtained at stage of hard dough to yellow stage by 11.9 ton/ha dry matter yield and 81 point silage quality. Italian ryegrass and pasture grasses including of orchardgrass, alfalfa and grass-legume pasture mixtures procuced also high quality bale silage by harvesting at stage of late blooming. However pre witting operation and formic acid addition was required for BS production of grass materials because of high water contents. Water contents of Italian ryegrass and other pasture species ranged 18.9%(Italian) to 20.8%(alfalfa). Silage quality point of Italian BS harvested at late blooing was increased from 72 to 88 by 1/2-one day pre wilting and 0.3% formic acid treatment. Silage quality of young plant materials of rye and other forage crops, barley and spring oat were also improved markedly through the pre wilting treatment and formic acid addition.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.210-218
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• 2018

Background: Soil respiration (Rs) is a major factor of the absorption and accumulation of carbon through photosynthesis in the ecosystem carbon cycle. This directly affects the amount of net ecosystem productivity, which affects the stability and sustainability of the ecosystem. Understanding the characteristics of Rs is indispensable to scientifically understand the carbon cycle of ecosystems. It is very important to study Rs characteristics through analysis of environmental factors closely related to Rs. Rs is affected by various environmental factors, such as temperature, precipitation, soil moisture, litter supply, organic matter content, dominant plant species, and soil disturbance. This study was conducted to analyze the effects of micro-topographical differences on Rs in forest vegetation by measuring the Rs on the ridge and southern slope sites of the broadly established Quercus mongolica forest in the central Korean area. Method: Rs, Ts, and soil moisture data were collected at the southern slope and ridge of the Q. mongolica forest in the Mt. Jeombong area in order to investigate the effects of topographical differences on Rs. Rs was collected by the closed chamber method, and data collection was performed from May 2011 to October 2013, except Winter seasons from November to April or May. For collecting the raw data of Rs in the field, acrylic collars were placed at the ridge and southern slope of the forest. The accumulated surface litter and the soil organic matter content (SOMC) were measured to a 5 cm depth. Based on these data, the Rs characteristics of the slope and ridge were analyzed. Results: Rs showed a distinct seasonal variation pattern in both the ridge and southern slope sites. In addition, Rs showed a distinct seasonal variation with high and low Ts changes. The average Rs measurements for the two sites, except for the Winter periods that were not measured, were $550.1\;mg\;CO_2m^{-2}h^{-1}$ at the ridge site and $289.4\;mg\;CO_2m^{-2}h^{-1}$ at the southern slope, a difference of 52.6%. There was no significant difference in the Rs difference between slopes except for the first half of 2013, and both sites showed a tendency to increase exponentially as Ts increased. In addition, although the correlation is low, the difference in Rs between sites tended to increase as Ts increased. SMC showed a large fluctuation at the southern slope site relative to the ridge site, as while it was very low in 2013, it was high in 2011 and 2012. The accumulated litter of the soil surface and the SOMC at the depth range of 0~5 cm were $874g\;m^{-2}$ and 23.3% at the ridge site, and $396g\;m^{-2}$ and 19.9% at the southern slope site. Conclusions: In this study, Rs was measured for the ridge and southern slope sites, which have two different results where the surface litter layer is disturbed by strong winds. The southern slope site shows that the litter layer formed in autumn due to strong winds almost disappeared, and while in the ridge site, it became thick due to the transfer of litter from the southern slope site. The mean Rs was about two times higher in the ridge site compared to that in the southern slope site. The Rs difference seems to be due to the difference in the amount of litter accumulated on the soil surface. As a result, the litter layer supplied to the soil surface is disturbed due to the micro-topographical difference, as the slope and the change of the community structure due to the plant season cause heterogeneity of the litter layer development, which in turn affects SMC and Rs. Therefore, it is necessary to introduce and understand these micro-topographical features and mechanisms when quantifying and analyzing the Rs of an ecosystem.