• Journal of Bio-Environment Control
• /
• v.20 no.4
• /
• pp.352-356
• /
• 2011

It is true that the industrial development has usually been accompanied with urbanization or centralization of population that has inevitably led to high-rise buildings and densely built-up living area in the cities. While it is badly needed to acquire as much green land within the city limits as possible to compensate for reduced space for recreational purpose in parallel with increasingly urbanized area, the living conditions of plants have become seriously devastated due to shortage of sun light walled-off by high-rise buildings and contaminated environment and air. The shade that is generated by high-rise and compact buildings hinders growth of plants, which makes it urgent to develop native ground cover plant that is strongly viable in the shade. For this purpose, Ligularia stenocephala, best known as greens for Ssam (rice and condiments wrapped in leaves) was cultivated under the 30%, 50%, and 80% shadings and observed to see if there would be any changes in soil conditions, growth of plants and chlorophyll contents depending on the shading rate. The leaf number was 10.8 pieces under the 50% shading and 8.4 under the 30%-shading, 7.7 pieces more than that cultivated under lighting. The leaf width turned out to be excellent from cultivation under the 50%- shading, an evidence indicating its possibility of being cultivated as native ground cover plant in the shade. The live weight of the plants cultivated under the shading increased to 31.63 g, 43.39 g and 19.40 g, respectively, compared to 90.43 g of those in the untreated control plot. The increase in growth of roots was particularly significant with 48.48 g in comparison to 12.33 g under 30% shading cultivation. The chlorophyll synthesis amounted to 46.2 under the 50% shading, showing an increase compared to 41.9 under lighting. The chlorophyll synthesis rather shrank under other shading conditions. The cultivation of Ligularia stenocephala under the 50% shading showed the best condition in growth as native ground cover plant.

• Investigative Magnetic Resonance Imaging
• /
• v.13 no.1
• /
• pp.81-87
• /
• 2009

Purpose : We sought to evaluate enhancement of plaque with gadolinium-based contrast agent by magnetic resonance imaging (MRI) in comparison with histopathology, namely lipid-rich and macrophage-rich components that were two representative characteristics of plaque vulnerability using atherosclerotic rabbit aorta in order to determine which histopathologic component is relevant to the enhancement. Materials and Methods : New Zealand white rabbit (n=4, weight 3.0 to 3.5 kg, all male) was used for animal model of atherosclerosis. Atherosclerotic aortic lesions were induced by high-cholesterol diet and double balloon injury. T1-weight axial images were acquired before and after gadolinium-based contrast agent using a 3-T MRI. MR images and the matched histopathological sections (n=35) were divided into 4 quadrants or 3 (n=130). Enhancement ratio (ER, ER=SIpost/SIpre) on MRI was calculated for each quadrant and compared with histopathology in regard to lipid-rich and macrophage-rich areas. Results : Lipid-rich quadrants were 72 and fibrous quadrants were 58. The number of quadrants which had macrophage-rich areas was 105 and that of quadrants which did not have macrophage-rich areas was 25. ER was significantly higher in lipid-rich quadrants than in fibrous quadrants (mean ER 2.25c$\pm$0.41 vs. 2.72$\pm$0.65, p=0.013). ER poorly correlated with macrophage-rich areas when lipid-component was controlled (correlation coefficient -0.203, p=0.236). Conclusion : Lipid-rich plaques showed stronger enhancement than fibrous plaques using a standard gadolinium-based extracellular contrast agent. Macrophage infiltration did not correlate with degree of enhancement. Further study is warranted that account for optimal time of imaging after contrast injection using various plaque models from early to advanced stages and all possible parameters associated with contrast enhancement.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.5
• /
• pp.434-451
• /
• 2017

For this study, groundwater samples for 3 years from 2011 through 2013 were collected at 106 groundwater monitoring site in Korea. These groundwater samples were analyzed for 13 pesticides such as cabofuran, pentachlorobenzene, hexachlorobenzene, simazine, atrazine, lindane (gamma-HCH), alachlor, heptachlor, chlordane (total), endosulfan (1, 2), dieldrin, endrin, 4,4-DDT. The objectives of this study were to determine the detection frequency and their concentrations of 13 pesticides and evaluate the health risk level considering ingestion, inhalation, and skin contact using concentrations of 13 pesticides in groundwater samples. An analysis was used for the simultaneous determination for 13 pesticides using GC-MS. GC-MS was performed on HP-5ms, using helium ($1ml\;min^{-1}$) as carrier gas. The average recoveries of the pesticides were from 92.8% to 120.8%. The limits of detection (LODs) were between $0.004{\mu}g\;L^{-1}$ and $0.118{\mu}g\;L^{-1}$ and the limits of quantification (LOQs) were between $0.012{\mu}g\;L^{-1}$ and $0.354{\mu}g\;L^{-1}$. 106 groundwater wells were selected. 54 wells were from well to monitor background groundwater quality and 52 wells were from well to monitor groundwater quality in industrial or contamination source area. Eight pesticides including pentachlorobenzene, lindane (Gamma-HCH), heptachlor, chlordane (total), Endosulfan (1, 2), dieldrin, endrin, and 4,4-DDT were not detected in groundwater samples. The detection frequency for hexachlorobenzene, alachlor, carbofuran and simazine was 23.4%, 11.4%, 7.3%, and 1.0%, respectively. Atrazine was detected once in 2011. The average concentrations were $0.00423{\mu}g\;L^{-1}$ for carbofuran, $0.000243{\mu}g\;L^{-1}$ for alachlor, $0.00015{\mu}g\;L^{-1}$ for simazine, and $0.00001{\mu}g\;L^{-1}$ for hexachlorobenzene. The detection frequency of hexachlorobenzene was high, but the average concentration was low. In the contaminated groundwater, the detection frequency for hexachlorobenzene, alachlor, carbofuran, simazine and atrazine was 26.1%, 21.3%, 7.1%, 1.9% and 0.3%, respectively. In the uncontaminated groundwater, detection frequency for hexachlorobenzene, carbofuran and alachlor were 20.2%, 7.5%, and 1.9% respectively. Simazine and atrazine were not detected at uncontaminated groundwater wells. According to the purpose of groundwater use, atrazine was detected for agricultural groundwater use. Hexachlorobenzene showed high detection frequency at agricultural groundwater use area where the animal feeding area and golf course area were located. Alachlor showed more than 50% detection frequency at cropping area, pollution concern river area, and golf course area. Atrazine was detected in agricultural water use area. By land use, the maximum detection frequency of alachlor was found near an orchard. For human risk assessment, the cancer risk for the 5 pesticides was between $10^{-7}$ and $10^{-10}$, while the non-cancer risk (HQ value) was between $10^{-4}$ and $10^{-6}$. For conclusion, these monitoring study needs to continue because of the possibility of groundwater contamination based on various purpose of groundwater use.

• Korean Journal of Agricultural Science
• /
• v.27 no.1
• /
• pp.25-32
• /
• 2000

This experiment was conducted to investigate the effect of feeding monensin on the growth performance and ruminal fermentation characteristics of Han-Woo cattle. Seventy two uncastrated Han-Woo male cattle(BW 267 kg) were randomly allotted to 0, 22, and 33 ppm monensin treatments, three replicates per treatment and eight heads per replicate. Animals were kept in an open barn for an 140-d feeding trial, Concentrates containing different levels of monensin and rice straw cut in 15cm length were fed ad libitum separately. The results obtained from this study were summarized as follows. 1. No significant difference was found in daily gain by monensin feeding. 2. Monensin did not affect the total feed (concentrate + roughage) intake: however, as the monensin level increased, the total feed intake tended to decrease, resulting in 5 % reduction in 33 ppm monensin treatment. 3. Although no significant difference was found among three treatments, 22 and 33 ppm monensin improved the feed efficiency(total feed/gain) by 5.2 % and 5.1 %, respectively, as compared to the 0 ppm monensin treatment. 4. Monensin did not affect the concentrations of ruminal total VFA and acetic acid consistently. Although not significant, monensin feeding of 22 and 33 ppm caused marked increase in ruminal propionic acid concentration, 13.8 % and 19.3 %, respectively. Ruminal butyric acid concentration decreased as monensin level increased. Monensin feeding, regardless of level, decreased the A/P ratio by 12.5 %. In conclusiuon, monensin feeding increased the propionic acid concentration, and decreased the butyric acid concentration and A/P ratio in the rumen. Animals fed monensin consumed less feed, causing the improvement in feed efficiency. Thus, monensin appeared to be a useful feed additive, directing the rumen fermentation in a more productive way. Feed efficiency improved similarly both in 22 and 33 ppm monensin treatments, indicating that 22 ppm might be good enough rather than the 33 ppm monensin level.

• The Korean Journal of Nuclear Medicine
• /
• v.39 no.1
• /
• pp.44-48
• /
• 2005

Purpose: Ethylenediamine-tetramethylenephosphonic acid (EDTMP) has widely used chelator for the labeling of bone seeking radiopharmaceuticals complexed with radiometals. $^{153}Sm$ can be produced by the HANARO reactor at the Korea Atomic Energy Research Institute, Taejon, Korea. $^{153}Sm$ has favourable radiation characteristics $T1/2=46.7\;h,\;{\beta}_{max}=0.81\;MeV\;(20%),\;0.71\;MeV\;(49%),\;0.64\;MeV\;(30%)\;and\;{\gamma}=103\;keV\;(30%)$ emission which is suitable for imaging purposes during therapy. We investigated the labeling condition of $^{153}Sm$-EDTMP and imaging of $^{153}Sm$-EDTMP in normal rats. Materials and methods: EDTMP 20 mg was solved in 0.1 mL 2 M NaOH. $^{153}SmCl^3$ was added to EDTMP solution and pH of the reaction mixtures was adjusted to 3 and 12, respectively. Radiochemical purity was determined with paper chromatography. After 30 min. reaction, reaction mixtures were neutralized to pH 7.4, and the stability was estimated upto 120 hrs. Imaging studies of each reaction were perfomed in normal rats (37 MBq/0.1 mL). Results: The labeling yield of $^{153}Sm$-EDTMP was 99%. The stability of pH 8 reaction at 60, 96 and 120 hr was 99%, 95%, 89% and that of pH 12 at 36, 60, 96 and 120 hr was 99%, 95%, 88%, 66%, respectively. The $^{153}Sm$-EDTMP showed constantly higher bone uptake from 2 to 48 hr after injection. Conclusion: $^{153}Sm$-EDTMP, labeled at pH 8 reaction condition, has been stably maintained. Image of $^{153}Sm$-EDTMP at 2, 24, 48 hr after injection, demonstrate that $^{153}Sm$-EDTMP is a good bone seeking radiopharmaceuticals.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.34 no.1
• /
• pp.26-32
• /
• 2014

'Dahan' (Avena sativa L.), a winter oat cultivar for forage use, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute Crop Science (NICS), Rural Development Administration (RDA) in 2011. It was derived from an original cross between $F_1$[Sprinter/73625] and 'Gwiri26'. Subsequent generations followed by the cross were handled in bulk and pedigree selection programs at Suwon. A line, 'SO99027-GB-B-113-4-4-3', was selected for cold tolerance and good agronomic characteristics and as a line name of 'Gwiri75'. The line 'Gwiri75' was subsequently evaluated for cold tolerance and forage yield during 3 years in four region such as Yesan, Iksan, Kimjae, and Jeju, from 2009 to 2011 and finally named as 'Dahan'. Though similar in heading date to the check cultivar Samhan, 'Dahan' had tall plant length and lodging resistance. It's average forage dry matter yield harvested at milk-ripe stage was 15.6 ton $ha^{-1}$, compared with 14.1 ton $ha^{-1}$ of check cultivar. Cultivar 'Dahan' was lower to the check cultivar 'Samhan' in protein content (8.4% and 9.9%, respectively), while it was superior to the check cultivar in total digestible nutrients (TDN) (60.8% and 59.3%, respectively), and in TDN yield $ha^{-1}$ (9.5 ton and 8.4 ton, respectively). Fall sowing of 'Dahan' is recommended only in the areas where daily minimum mean temperatures are averaged higher than $-7^{\circ}C$ in January, and excluded in mountain area where frost damage is presumable.

• Korean Journal of Environment and Ecology
• /
• v.33 no.5
• /
• pp.497-505
• /
• 2019

Winter hibernation in wildlife is a unique physiological mechanism for survival. For Asiatic black bears (ABBs, Ursus thibetanus ussuricus), hibernation is a very important but dangerous time for the cubs to be born. This study surveyed ABBs living in Mt. Jiri To examine the relationship between the temperature during hibernation and the hibernation days. The survey found that the average start and end dates of hibernation was December 7 and April 20, respectively. The average day of hibernation for females who gave birth was $167.8{\pm}22.6$ days. The average temperature of 5 days before hibernation was $0.6{\pm}4.1^{\circ}C$, the average temperature during hibernation was $1.3{\pm}2.43^{\circ}C$, and the average temperature of five days before the end of hibernation was $12.6{\pm}3.1^{\circ}C$. The hibernation days of the females that did not give birth to cubs and the males were $120.4{\pm}25.7$ days and $113.6{\pm}25.8$ days, respectively. The average temperatures of 5 days before hibernation was $2.1{\pm}4.2^{\circ}C$ and $-1.8{\pm}3.9^{\circ}C$, respectively. The average temperature during hibernation was $-0.2{\pm}1.6^{\circ}C$ and $-0.4{\pm}2.4^{\circ}C$. The average temperatures of five days before the end of hibernation were $7.8{\pm}3.6^{\circ}C$ and $7.8{\pm}4.4^{\circ}C$. These results indicate that females giving birth to cubs have higher hibernation days and average temperatures than the females that do not give birth and the males, which is due to the process of raising cubs during hibernation. The hibernating days and mean temperature for the groups in each lifecycle did not show any difference between the groups. This study is meaningful in that it disclosed the characteristics of hibernating intrinsic behaviors of ABBs. It observed the specific hibernation period and temperature of ABBs bears inhabiting in Mt. Jiri and examined the difference by sex, female(giving birth) and life cycle group according to temperature. The results of this study can be used to prevent the conflict between ABBs and humans in winter and spring and establish the preservation management plan.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.5
• /
• pp.794-800
• /
• 2011

To develop biochar for soil conditioner using water plants, characteristics of nutrients release of biochars were investigated under different water plants, manufacturing times and manufacturing temperatures. Under different water plants for manufacturing biochar, the concentrations of T-N and $P_2O_5$ in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. The concentrations of $K_2O$ in the water were in the order of TYHOR ${\fallingdotseq}$ CRXDM > ZIZLA > PHRCO > MISSA. Under different manufacturing times for biochar, the concentrations of T-N, $P_2O_5$ and $K_2O$ in the water with biochars were higher in the order of 2 hr > 30 min ${\fallingdotseq}$ 1 hr. The concentrations of T-N, $P_2O_5$ and $K_2O$ in the water with biochars were on the order of $350^{\circ}C$ > $500^{\circ}C$ > $600^{\circ}C$ under different manufacturing temperatures. Total amounts of T-N and $K_2O$ releases in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. Using biochars by water plants, total amounts of $P_2O_5$ releases in the water with biochars were on the order of CRXDM > ZIZLA > MISSA >PHRCO > TYHOR. The results of this study suggest that biochars by water plants can supply some of the nutrient requirements of crops and can be a valuable fertilizer.

• Korean Journal of Breeding Science
• /
• v.49 no.2
• /
• pp.80-86
• /
• 2017

'Jungmo2501' (Avena sativa L.), a winter oat for forage use, was developed by the breeding team at the National Institute of Crop Science, RDA in 2010. The following is the characteristics of 'Jungmo2501' that is characterized as light green leaf, yellow brown culm and whitish yellow grain. The heading date of 'Jungmo2501' was about 3 days earlier than that of check cultivar 'Samhan'(May 7 and May 10, respectively). Its plant height was 11 cm longer than 103 cm of the check, and the leaf blade ratio of aerial parts was 26 % higher than the check (11.8% and 9.4%, respectively). The cold tolerance, resistance to lodging and wet injury of 'Jungmo2501' were similar to those of the check. The average forage dry matter yield of 'Jungmo2501' harvested at milk-ripe stage was 5% higher than the check ($15.5ton\;ha^{-1}$ and $14.7ton\;ha^{-1}$, respectively). 'Jungmo2501' was higher than the check in terms of protein content (6.6% and 5.9%, respectively), neutral detergent fiber (58.5% and 57.6%, respectively), and acid detergent fiber (34.5% and 32.1%, respectively), while total digestible nutrients was lower than the check (61.6% and 63.6%, respectively), and TDN yield was $0.37ton\;ha^{-1}$ more than that of the check ($9.71ton\;ha^{-1}$ and $9.34ton\;ha^{-1}$, respectively). The silage grade of 'Jungmo2501' estimated by Flig score showed level II, meaning good quality. Fall sowing cropping of 'Jungmo2501' is recommended only for areas where average daily minimum mean temperatures in January are higher than $-6^{\circ}C$.

• Korean Journal of Environment and Ecology
• /
• v.32 no.6
• /
• pp.603-617
• /
• 2018

This study surveyed the diversity and community characteristics of benthic macroinvertebrates and freshwater fish, which are the main animal classifications in a hydro ecosystem, from May to September 2017 in the western plains of the Demilitarized Zone (DMZ). The results showed a total of 125 species of benthic macroinvertebrates belonging to 66 families, 19 orders, and four phyla in the streams and wetlands. Among benthic macroinvertebrates, Coleoptera (27 spp.: 21.60%) was the largest group in terms of species richness followed by Odonata (26 spp.: 20.80%), non-Insecta (22 spp.: 17.60%), and Hemiptera (11 spp.: 8.80%) occupying in the lentic area. Of the feeding function groups (FFGs), predators (51 spp.: 56.67%) showed a relatively larger presence, indicating the dominance of hygrophilous invertebrates that usually inhabit the freshwater wetlands or ponds. Of the habitat oriented groups (HOGs), climbers (33 spp.: 24.44%) and burrowers (17 spp.: 12.59%) were the dominant groups. This observation is typical in a slow flowing habitat and can lead to the disturbance of the ecosystem due to cannibalism among predators. Cannibalism can be caused by stress induced by various population and environmental factors. For the ecosystem services benchmark (ESB) value, site 13 appeared to be the highest with 82 marks while other sites showed relatively lower rates and indices (III water quality class with ${\alpha}$-mesosaprobic). The analysis result of stability factors showed that almost all sites were evaluated to be the I characteristic group with high resilience and resistance or the III characteristic group that was sensitive to environmental disturbance and formed uneven and unstable communities. Of the freshwater fishes, 46 species (3,405 individuals) belonging to 39 families and 18 orders were identified in all the investigated sites. Among them, Cyprinidae (30 spp.: 65.2%) was the largest group, and Zacco koreanus was identified as the dominant species (728 individuals, 21.4%). The survey of freshwater fish communities found both stable communities (sites 7 and 13) with low dominant index (0.39) and high diversity index (2.29) and unstable communities (sites 2, 3, 8, and 10) in opposite tendency. This survey found five Korean endemic species, 17 species belonging to the export controlled species, two endangered species level II (Lethocerus deyrollei and Cybister chinensis), and rare species (Dytiscus marginalis czerskii) among benthic macroinvertebrates. The survey also found an invasive species, Ampullarius insularus, which was distributed throughout the whole area and thus can continuously disturb the ecosystem in the western plain area in the DMZ. Of freshwater fish, one natural monument (Hemibarbus mylodon) and three endangered species level II (Acheilognathus signifer, Gobiobotia macrocephalus, and G. brevibarba) were observed. The survey also found four introduced species (Pomacea canaliculate, Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides) in the western DMZ area, indicating the need for the protection and conservation measures.