• Journal of Environmental Science International
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• v.24 no.2
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• pp.163-174
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• 2015

The Youngsan Lake was constructed to supply agricultural water to the extensive rice fields in the basin of the lake in 1981. Hypoxia has often developed in the bottom water of the lake during the warm season although the water depth is relatively shallow (< 16 m). We investigated the spatial and temporal variations of dissolved oxygen (DO) and physical properties such as water temperature, salinity and turbidity to elucidate the effects of change in physical properties on DO dynamics in the lake. Vertical profiles of DO, temperature, salinity, and water density were also explored to verify the development of stratification in relation to DO variation in the water column. Hypoxia (DO < $2mg\;L^{-1}$) was not observed in the upper regions whereas hypoxia was detected in the lower regions during the warm season. Thermocline generally developed in the lower regions during the warm season unlike the previous studies in which no thermocline was observed. However, water column was well mixed when freshwater water was discharged from the reservoir through the sluice gate of the dike. DO concentrations also decreased when halocline or pycnocline developed during the dry season suggesting that the vertical stratification of water column affects DO dynamics although the water depth is shallow in the Youngsan lake.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1594-1608
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• 2009

Research on barley as an animal feed started some decades ago but its utilization in animal production has been limited to countries that grow the crop extensively. Corn has been the most popular energy feed in cattle rations, but the high price of corn and the decreased supply of the grain in the international market have shifted the focus of the animal industry to other cereal crops like barley. Studies have indicated that growth performance of cattle fed barley-based diets has been generally comparable with that of those fed corn-based diets, while results for cattle fed whole-crop barley silage have been more variable. Beef from cattle fed barley-based diets has proved to be as tender and as acceptable for taste as that from animals fed other finishing diets when compared at similar growth rates and degree of finish. The barley crop contains good amounts of antioxidants like 2"O-GIV isovitexin, so from the meat science point of view, a desirable influence of these components on meat quality traits such as meat color, oxidative stability and sensory characteristics might be expected. Furthermore, the effect of the distinctive fatty acid profile of beef fed from whole-crop barley silage on sensory traits is also an important subject to be elucidated. A lot of studies have been made over past decades on the effect of barley, and especially whole crop barley, on beef cattle production and meat quality, but these data have not been collectively documented in a review. The current review re-visits previous literature to underline the effects of barley in the diet on beef quality traits and to identify areas for further studies.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.103-108
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• 1985

A series of experiments were conducted to determine the effect of pH, salinity, seeding depth, and moisture stress on the germination and growth of Echinochloa colons (L.) Link. Germination significantly decreased at pH 10, but shoot lengths were not affected by the pH tested. Germination was not affected by salt concentrations of up to 0.1%, but was significantly reduced at 0.5%. A 1.0% salt concentration did not significantly reduce shoot length. Increase in seeding depth significantly reduced emergence. Irrespective of seeding depth, the coleoptilar node was always just below the soil surface. Delayed and decreased germination was obtained at -4.6 bars of simulated water potential, while no germination occurred at -9.8 bars. Soil moisture stress significantly reduced plant height, delayed panicle initiation, and reduced seed production.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.705-715
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• 2013

The response of the freshwater microalga Chlorella vulgaris to mercuric ion ($Hg^{2+}$) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing $Hg^{2+}$ concentration. The maximum photochemical efficiency of photosystem II(Fv/Fm) changed remarkably with increasing $Hg^{2+}$ concentration and treatment time. In particular, above $200{\mu}M\;Hg^{2+}$, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by $Hg^{2+}$; the fluorescence emission decreased considerably in steps J, I, and P with an increase in $Hg^{2+}$ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ${\Phi}_{PO}$, ${\Psi}_O$ and ${\Phi}_{EO}$) decreased with increasing $Hg^{2+}$ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ${\Phi}_{PO}$, ${\Psi}_O$, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.275-275
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• 2017

Dressing is a seasoned mixture usually used as a stuffing in food. Quality characteristics and antioxidant activity of fruit dressing using lentil legume were investigated. The four groups were divided into D-1(fruit dressing purchased from the local market in Deagu, Korea), D-2 (grapefruit-sugaring dressing prepared with grapefruit sugaring and lentil legume paste), D-3 (vinegar dressing purchased from the local market in Deagu, Korea), D-4 (pineapple-vinegar dressing prepared with pineapple vinegar and lentil legume paste), and then they were analyzed with regard to general compositions, Hunter's color value, mineral and free amino acid content and antioxidant activities. The pH and titratable acidity in all samples ranged from 2.9 to 4.6 and from 0.6 to 1.2%, respectively. The crude protein content were 2.29% for D-2 dressing and 4.03 for D-4 sample, while were not detected D-1 and D-3 samples. In case of Hunter's value, The ' L'and 'a' values of all samples ranged from 45.98 to 56.54 and from -1.59 to 3.30, respectively. The D-4 sample exhibited the higher levels of Ca (215.40 mg/kg), K (1,105.83 mg/kg), Mg (233.63 mg/kg) and Fe (13.78 mg/kg). The levels of heavy metals (As, Pb, Cd and Hg) in all samples were not detected. The contents of total amino acid in D-3 and D-4 samples were 8.269 and 3.419 mg/mL, respectively. The highest contents of total phenols($191.13{\mu}g\;GAE/mL$) and DPPH radical scavenging activity(93.69%, Inhibition) were observed in D-4 sample.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.59-70
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• 2000

In nature, plant diseases, insects and parasites (hereafter called as "pest") must be co-survived. The most common expression of co-survival of a host crop to the pest can be tolerance. With tolerance, chemical uses can be minimized and it protects environment and sustains host productivity and the minimum pest survival. Tolerance can be applicable in all living organisms including crop plants, lifestocks and even human beings. Tolerant system controls pest about 90 to 95% (this pest control system often be called as horizontal or partial resistance), while the use of chemicals or selection of high resistance controls pest 100% (the most expression of this control system is vertical resistance or true resistance). Controlling or eliminating the pests by either chemicals or vertical resistance create new problems in nature and destroy the co-survial balance of pest and host. Controlling pests through tolerance can only permit co-survive of pests and hosts. Tolerance is durable and environmentally-friend. Crop cultivars based on tolerance system are different from those developed by genetically modified organism (GMO) system. The former stabilizes genetic balance of a pest and a host crop in nature while the latter destabilizes the genetic balance due to 100% control. For three decades, the author has implemented the tolerance system in breeding maize cultivars against various pests in both tropical and temperate environments. Parasitic weed Striga species known as the greatest biological problem in agriculture has even been controlled through this system. The final effect of the tolerance can be an integrated genetic pest management (IGPM) without any chemical uses and it makes co-survival of pests in nature.in nature.

• The Plant Pathology Journal
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• v.20 no.1
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• pp.67-74
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• 2004

A complete understanding of the epidemiological factors required for optimum for disease development facilitates the design of effective and reliable screening techniques and also disease prediction models. An attempt was made to study the effects of different temperatures ($15-35^{\circ}C$) and leaf wetness periods (4-24 h) on the development of late leaf spot (LLS) in three groundnut genotypes differing in their susceptibility to LLS infection. Irrespective of the genotype, the disease progress evaluated based on different components of resistance was maximum between $15-20^{\circ}C$ and minimum between $20-25^{\circ}C$. At temperatures $\geq$$30^{\circ}C$, LLS development was insignificant. The overall severity of LLS increased with an increase in the leaf wetness period from 4 h to 12 h a day. Further increase of wetness period to 16 h resulted in a rapid increase in the severity. Thereafter, the disease severity gradually decreased with an increase in the wetness period. The effect of temperature and wetness periods on the individual component of disease quantification was not uniform compared between genotypes with different levels of susceptibility/resistance to LLS infection. The results of this study indicate that temperature and leaf wetness period are critical in late leaf spot screening programs since the expression of disease symptoms measured from disease initiation till defoliation, varied differently in the test genotypes with respect to change in these two parameters.

• Journal of the Korean GEO-environmental Society
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• v.18 no.7
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• pp.21-35
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• 2017

The 3S Basin is described as an important contributor in terms of many aspects in the Mekong River Basin in Southeast Asia. However, the 3S Basin has been suffering adverse consequences of changing discharge and sediment, which are derived from farming, deforestation, hydropower dam construction, climate change, and soil erosion. Consequently, a large population and ecology system that live along the 3S Basin are seriously affected. Accordingly, the calculating and simulating discharge and sediment become ever more urgent. There are many methods to simulate discharge and sediment. However, most of them are designed only during a single rainfall event and they require many kinds of data. Therefore, this study applied a Catchment-scale Soil Erosion model (C-SEM) to simulate discharge and sediment in the 3S Basin. The simulated results were judged with others references's data and the observed discharge of Strung Treng station, which is located in the mainstream and near the outlet of the 3S Basin. The results revealed that the 3S Basin distributes 31% of the Mekong River Basin's total discharge. In addition, the simulated sediment results at the 3S Basin's outlet also substantiated the importance of the 3S Basin to the Mekong River Basin. Furthermore, the results are also useful for the sustainable management practices in the 3S Basin, where the sediment data is unavailable.

• Journal of Environmental Science International
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• v.27 no.7
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• pp.561-575
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• 2018

Agricultural soils around springwaters heavily affected by pesticide run-off and around wells considering the regional characteristics were collected at 24 stations in Jeju Island, and the physicochemical properties and adsorption and leaching characteristics of four nonionic pesticides (diazinon, fenitrothion, alachlor, and metalaxyl) were investigated. The values of the major soil factors affecting the adsorption and leaching of pesticides, namely, soil pH($H_2O$), organic matter content, and cation exchange capacity (CEC), were in the range of 4.64 ~ 8.30, 0.9 ~ 13.1% and 12.7 ~ 31.7 meq/100 g, respectively. The Freundlich constant, $K_F$ value, which gives a measure of the adsorption capacity, decreased in the order of fenitrothion > diazinon > alachlor > metalaxyl, which was identical to their lower water solubility. Among the collected soils, the $K_F$ value was very highly correlated with organic matter content ($r^2=0.800{\sim}0.876$) and CEC ($r^2=0.715{\sim}0.825$) and showed a high correlation with clay content ($r^2=0.473{\sim}0.575$) and soil pH($H_2O$) ($r^2=0.401{\sim}0.452$). The leaching of pesticides in the soil column showed a reverse relationhip with their adsorption in soils, i.e., the pesticides leached more quickly for the soils with lower values of organic matter content and CEC among the soils and for the pesticides with higher water solubility.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1789-1800
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• 2019

Objective: Although alveolar macrophages play a key role in the respiratory immunity of livestock, studies on the mechanism of differentiation and survival of alveolar macrophages are lacking. Therefore, we undertook to investigate changes in the lipid metabolism and survival rate, using 3D4/31 macrophages and Dudleya brittonii which has been used as a traditional asthma treatment. Methods: 3D4/31 macrophages were used as the in vitro porcine alveolar macrophages model. The cells were activated by exposure to phorbol 12-myristate 13-acetate (PMA). Dudleya brittonii extraction was performed with distilled water. For evaluating the cell survival rate, we performed the water-soluble tetrazolium salt cell viability assay and growth curve analysis. To confirm cell death, cell cycle and intracellular reactive oxygen species (ROS) levels were measured using flow cytometric analysis by applying fluorescence dye dichlorofluorescein diacetate and propidium iodide. Furthermore, we also evaluated cellular lipid accumulation with oil red O staining, and fatty acid synthesis related genes expression levels using quantitative polymerase chain reaction (qPCR) with SYBR green dye. Glycolysis, fatty acid oxidation, and tricarboxylic acid (TCA) cycle related gene expression levels were measured using qPCR after exposure to Dudleya brittonii extract (DB) for 12 h. Results: The ROS production and cell death were induced by PMA treatment, and exposure to DB reduced the PMA induced downregulation of cell survival. The PMA and DB treatments upregulated the lipid accumulation, with corresponding increase in the acetyl-CoA carboxylase alpha, fatty acid synthase mRNA expressions. DB-PMA co-treatment reduced the glycolysis genes expression, but increased the expressions of fatty acid oxidation and TCA cycle genes. Conclusion: This study provides new insights and directions for further research relating to the immunity of porcine respiratory system, by employing a model based on alveolar macrophages and natural materials.