• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.61-65
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• 2011

The objective of this study was to examine the effect of various discontinuous Percoll washing conditions on motile sperm recovery rate and motion kinematics. Frozen semen samples from 3 bulls (0.5 ml plastic straws, 6% glycerol in egg yolk-Tris-glycerol extender) were thawed in $37^{\circ}C$ water bath for 1 min. After thawing, the mixed semen samples were randomly allocated to 12 treatment groups. Briefly, the spermatozoa were centrifuged for three different time lengths (10, 20, and 30 min) at two gravities ($300{\times}g$ and $700{\times}g$) through two concentrations of discontinuous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll and 2 ml 90%: 2 ml 45% Percoll to remove extender, debris, and dead spermatozoa. Motile sperm recovery rate and motion kinematics were evaluated by computer assisted sperm analyzer using Makler counting chamber. Sperm motility (%) and motile sperm recovery rate showed similar pattern in all treatment groups. However, sperm motility (%) and motile sperm recovery rate were highest at $700{\times}g$ for 30 min through a discontionous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll. There were no significant differences in motion kinematics after various Percoll washings. These results suggest that force of centrifugation, centrifugation time, and Percoll volume significantly affect motile sperm recovery rate.

• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.326-333
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• 2011

The need for rapid on-site monitoring of hydroponic macronutrients has led to the use of ion-selective electrodes, because of their advantages over spectrophotometric methods, including simple methodology, direct measurement of analyte, sensitivity over a wide concentration range, and low cost. Stability and repeatability of response can be a concern when using multiple ion-selective electrodes to measure concentrations in a series of samples because accuracy might be limited by drifts in electrode potential. A computer-based measurement system could improve accuracy and precision because of both consistent control of sample preparation and easy calibration of sensors. Our goal was to investigate the applicability of a cobalt-based electrode used in conjunction with a laboratory-made automated test stand for quantitative determination of ${PO_4}^-$ in hydroponic solution. Six hydroponic solutions were prepared by diluting highly concentrated paprika hydroponicsolution to provide a concentration range of 1 to 300 ppm $PO_4$-P. A calibration curve relating electrode response to phosphate in paprika hydroponic solution titrated to pH 4 with 0.025M KHP was developed based on the Nikolskii-Eisenman equation with a coefficient of determination ($R^2$) of 0.94. The laboratory-made test stand consisting of three cobalt-based electrodes measured phosphate concentrations similar to those obtained with standard laboratory methods (a regression slope of 0.98 with $R^2$ = 0.80). However, the y intercept was relatively high, 30 ppm, probably due to the relatively large amount of variation present among multiple measurements of the same sample. Further studies on the high variation in EMFs obtained with cobalt electrodes during replicate measurements were required for P estimations comparable to those obtained with standard laboratory instruments.

• Analytical Science and Technology
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• v.28 no.5
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• pp.353-360
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• 2015

Boiling is an efficient removal method to reduce radon in groundwater when ventilating indoor air. 13 groundwater samples with various radon concentrations were used to evaluate the reduction rate of radon with heating temperature and time. The groundwater samples were obtained by Bladder pump and on-situ measurements such as dissolved oxygen (DO) and hydrogen concentration (pH) and so on were carried out by a flow cell system isolated from the ambient atmosphere environment. All samples for measuring radon in groundwater were analyzed by liquid scintillation counter (LSC). The experiment result showed that increasing groundwater temperature enhanced radon removal rate but the initial radon concentration with high level lowered the removal rate. This means that radon reduction in groundwater by heating needs more heating energy and longer heating time with radon concentrations. Radon removal rate in groundwater, therefore, mainly depends on the initial radon concentration, heating temperature, and heating time.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.2
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• pp.161-167
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• 2001

Objective: Granulocyte-macrophage colony stimulating factors known to be secreted in murine and human reproductive tract. The development of human, bovine and murine embryos could be promoted by addition of GM-CSF in culture medium. However, the pregnancy and implantation rate of embryos cultured in GM-CSF have not been evaluated. The aim of this study was to assess the effect of GM-CSF in embryo development, pregnancy and implantation rate. Methods: A total of 191 IVF cycles were divided into control and GM-CSF supplement group (control=96, GM-CSF=95). The embryos were cultured for three day with or without 2 ng/ml of recombinant human GM-CSF. The quality of embryo, developmental velocity, pregnancy and implantation rates were compared. Results: There was no difference in age, number of gonadotropin ampules used, number of oocytes and fertilization. The number of ICSI cycle was higher in GM-CSF group. In GM-CSF group, G-1 grade embryos were the highest in proportion (56.4%), while G-2 grade embryos were highest (44.3%) in control group. The developmental velocity of embryos were not different between GM-CSF and control group. The pregnancy and implantation rates were significantly higher in GM-CSF group than control (47.4% vs. 33.3%, 17.0% vs. 11.1% respectively). Conclusion: By adding GM-CSF in culture medium, the quality of embryo, pregnancy and implantation rate could be improved.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.339-344
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• 2011

Ulmus davidiana var. japonica Rehder (Urticales: Ulmaceae) (UD) is a tree widespread in northeast Asia. It is traditionally used for anticancer and anti-inflammatory therapy. The present study investigated the effect of an ethanol extract of UD on vascular tension and its underlying mechanism in rats. The dried root bark of UD was ground and extracted with 80% ethanol. The prepared UD extract was used in further analysis. The effect of UD on the cell viability, vasoreactivity and hemodynamics were investigated using propidium iodide staining in cultured cells, isometric tension recording and blood pressure analysis, respectively. Low dose of UD ($10{\sim}100{\mu}g/ml)$ did not affect endothelial cell viability, but high dose of UD reduced cell viability. UD induced vasorelaxation in the range of $0.1{\sim}10{\mu}g/ml$ with an $ED_{50}$ value of $2{\mu}g/ml$. UD-induced vasorelaxation was completely abolished by removal of the endothelium or by pre-treatment with L-NAME, an inhibitor of nitric oxide synthase. UD inhibited calcium influx induced by phenylephrine and high $K^+$ and also completely abolished the effect of L-NAME. Intravenous injection of UD extracts (10~100 mg/kg) decreased arterial and ventricular pressure in a dose-dependent manner. Moreover, UD extracts reduced the ventricular contractility (+dP/dt) in anesthetized rats. However, UD-induced hypotensive actions were minimized in L-NAME-treated rats. Taken together, out results showed that UD induced vasorelaxation and has antihypertensive properties, which may be due the activation of nitric oxide synthase in endothelium.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.85-97
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• 2003

This study was aimed at suggest a proper logging method of mountain forest using geographic information system(GIS) based on digital terrain model(DTM) in the National Forest at Mt. Kumsan in Namhae-gun, Gyungsangnam-do, which has about 2,948 ha in area. The areal percentage of 201 to 250m in the elevation was about 15.5%, elevation of 251 to 300m was 14.5%, and 78.75% for higher than 400m. The accumulated areal percentage of below 30% in the gradient was 17.2%, and 81.0% for steeper than 60%. The area for tractor skidding was 17.2%(511.7ha), the area for tractor attached winch skidding was 63.8%(1,896.3ha) and 18.4%(545.5ha) for cable yarding. It is important to choose the proper logging machines for timber harvesting. In general, the selection of logging operation system was affected several major environmental factors like as terrain conditions(slope gradient, slope length) and stand factors. The rate of middle slope gradients in terrain conditions showed higher than that of steep slope gradients in this area. Therefore, it considered that the logging operation system in this area could apply to tractor+winch operating machine according to terrain conditions.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.722-733
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• 2019

This study was carried out to provide basic information for the ecological preservation management of temple forest (Donghaksa, Gapsa, Sinwonsa) by investigating the ecological characteristics of vegetation structure of the Cultural Heritage Site in Mt. Gyeryongsan National Park based on the Braun-Blanquet vegetation survey method from September 2018 to May 2019. As a result of hierarchical cluster analysis, the forest vegetation was classified into 3 vegetation units (Zelkova serrata - Akebia quinata - Kerria japonica community, VU1; Quercus serrata - Callicarpa japonica - Carpinus cordata community, VU2; and Pinus densiflora - Prunus sargentii - Fraxinus sieboldiana community, VU3). The indicator species of each vegetation unit were 12 taxa, 8 taxa, and 6 taxa, respectively. The result of the importance value analysis showed that Z. serrata had the highest importance value in all vegetation units, and the result of the species diversity analysis showed that the species diversity of VU3 was 0.939, which was relatively higher than other vegetation units. The result of the CCA of correlation between vegetation units and abiotic environmental factors showed that VU2 had a negative correlation with altitude, and biotic environmental factors had no significant correlation with vegetation units.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.216-222
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• 2016

In relation to the impact of cumulative rainfall on landslides in accordance with the cumulative number of days, for the more than 100 mm rainfall, the 3 days cumulative rainfall experienced 64.9% of the total points, which is 986 points out of the 1520 points. The 5 days cumulative rainfall period experienced 60% of the total landslides, which is 846 points out of 1520 points analyzed. The 3 days or 5 days cumulative rainfall thus had a greater effect on landslides than the other days. In addition, for the 101-200 mm rainfall, more landslides occurred in the 10 days cumulative number of days, for the 201-300 mm, more landslides occurred in the 14 days cumulative number of days, whereas the 18 days cumulative number of days had more landslides for the 301-400 mm rainfall. Thus, it is imperative to take into consideration cumulative rainfall and the cumulative number of days of rainfall in the establishment of forecasting and warning systems for landslides, to minimize the damage caused to life and property by landslides.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.16-23
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• 2010

Experiments were performed for investigate the immune activities on human B and T cell growth and secretion of their cytokines. Also, antibodies in serum were investigated in female ICR mouse by feeding the extracts of Acer mono at dose of 30 and 100 mg/mL of one day orally for 15 days. The cytotoxicity of the samples on normal human cell (HEL299) was below 24.15% in adding the all extracts. Both human immune B and T cells were increased up to about 40% by the high pressure extraction process. The secretion of cytokines (IL-6, TNF-${\alpha}$) on human B and T cells were increased up to 20-50% by adding the high pressure extraction process compare to the hot water extraction process. Also, total serum IgG levels increased by feeding Acer mono extacts. It can be conclude that optimum condition for efficient extraction of Acer mono as functional materials is solvent extraction process using water with high pressure at below $100^{\circ}CA$ than typical process.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.157-163
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• 1993

The present study focuses on simulating river profile changes downstream of the Daecheong multipurpose dam by using the computer program HEC-6, which was developed by the United States Army Corps of Engineers. The dam locates at the Keum river, a typical alluvial stream, whose bed material is composed mostly of fine and medium sands. The study reveals that after the completion of dam, a 15 km long reach downstream from the regulatory dam was severely degraded by about 2~3 m. No further severe degradation of this reach is expected, however, because the river-bed of this reach has been well armored since then with gravels and cobbles. Some places in the study reach were degraded locally by 2 m, due mainly to the large-scale gravel mining activities in that reach. On the other hand, a 20 km long reach in downstream study reach is aggraded more or less by 0.5~1 m. Calculation by the computer program HEC-6 is close to measurement for the study river reach. According to the results by HEC-6, the study river reach would remain generally stable in the future, except a few places in the mid-upstream where further river-bed degradation of 1~2 m would occur and a few places in the far downstream where local river-bed aggradations of about 0.5 m would occur.