• The Korean Journal of Ecology
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• v.26 no.3
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• pp.135-142
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• 2003

Four legume plants showed better growth by the external nitrogen supply rather than the symbiotic nitrogen fixation only under salt additions. In case of Glycine max and Phaseolus angularis, total nitrogen contents decreased by high salinity level but their amino acid levels significantly increased with the increase of salt treatments and indicated high soluble-/insoluble-N ratios. Cassia tora and Albizzia julibrissin contained less amino acids than G. max and P. angularis but total N (esp. insoluble N fraction) increased with higher salt levels. Asparagine occurred as a main amino acid especially in G. max and P. angularis and can be seen as potential N-storage form in these plants. It might be play an important role for the osmoregulation mechanism under the saline condition. Meanwhile, to investigate what kinds of nitrogen sources are effective for overcoming salt stress on soybean plants, various N forms and concentrations (NH₄NO₃-N, NO₃-N, NH₄NO₃-N; 2.5 and 5 mM) were additionally supplied to the salt gradient medium. Soybean plants treated with NH₄NO₃-N showed the best growth up to 40 mM NaCl and NO₃- fed plants indicated good growth even at 80 mM NaCl treatments. Contrary to NH₄NO₃- and NO₃- fed plants, NH₄/sup +/- fed plants showed remarkable growth reduction and died by 40 and 80 mM NaCl treatments after the first harvest (15th day). Consequently, these results suggest that salt excluding and resistant capacities of soybean plants under NaCl treatments are increased in order of NH₄ - N, control, NO₃- N and NH₄NO₃- N depending on N concentration except NH₄- N treatments.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.3-11
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• 2015

The current real estate market is in a state that is considerably shrink due to the recession and long-term reduction of trading. In response, the government recently announced an innovative way for the middle-class residential housing and it is taking the lead to activate the real estate market. Meanwhile, the domestic housing market is entering a transition period, including structural changes of household structure, changes from joeonse to rent increasingly. Also single-member households will rise steeply, so that makes the high demand of small houses. In addition, the domestic construction industry is interested in new technology called Modular building. The Modular construction is an off-site construction system that shorten construction period, eco-friendly building technology and mobility etc, which can be used in various field. Overall, there are two major issues of the current market, one is the change of the real estate market, and the other is the modular construction. This study will propose modular business model in the rental market through the analysis the profitability of the modular business scenarios and IRR analysis.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.495-520
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• 2018

Because of structural changes in the international oil market and the economy, it is widely recognized that the impact of oil shocks on the economy has weaken since the mid-1980s. This study tries to examine the validity of the recent perception about the relationship between oils shocks and the economy, estimating the time-varying effects of oil shocks on the Korean economy. The results show that the dynamic effects of oil shocks normalized to a one standard deviation has been relatively constant, in contrast to the recent perception and a number of existing studies. In addition, because the shape of impulse response functions at each point in time spanning from 1984:II to 2017:IV has not been changed significantly, it seems that the propagation mechanism of oil shocks also has not been substantially altered. These findings indicate that even though structural changes of the economy, such as the reduction in the share of oil consumption and the spread of high-efficiency energy technologies, have been rapidly progressed, it is not still enough to offset the negative effects of oil shocks. Rather, it seems that the recent perception about the shrinking effects of oil shocks is mainly due to the assumptions that do not reflect changes in the size of oil shocks. In particular, this problem appears more pronounced in the case of the typical a one standard deviation increase oil shock under homoskedasticity assumption, which is widely adopted in the most VAR analyses. Therefore, in estimating the effects of oil shocks on the economy, it is important to specify the correct model and normalization method, to reflect changes in the size of oil shocks.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.353-360
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• 2010

The Kyunggi Bay in mid-west of Korea is a relatively large estuarine system that connects the Han River system with Yellow Sea. Due to macro-tidal range of more than 8 m, the urban estuary shows deep tidal channels and wide tidal flats. Since last 30 years, the coastal development is undergoing, yielding noticeable change in environment. Particularly the tidal flat dynamics are generally accepted as being related with tidal residual flows in this area (Kim et al., 2009). We have estimated the annual variation and vertical structure of residual currents with one-year long observed flows in two major tidal channels of Kyunggi Bay. The moving average method and tidal current harmonic analysis yield nearly the same results on residual flow. The residual flow in Jangbong channel ranges from 20 cm/s in summer to 30 cm/s in winter. It is noticeable that the residual flow in Jangbong channel is flood dominant throughout the year, while the flow in Seokmo channel is ebb-dominant residual flow with current speed range of 20-40 cm/s. Due to the baroclinic response of relatively shallow estuary, significant reduction of energy in bottom layers have been observed, indicating the importance of residual circulation to the tidal flat behavior.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.242-248
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• 1986

To study the effect of cold water irrigation at the reproductive growth stage of rice plants on several growth characters related to source and sink and nutrient uptake, the present experiment was carried out under the different conditions of water temperature and water depth. Deep irrigation with normal temperature water increased culm length, panicle length and panicle exsertion but with cold water resulted adversely. Most sensi-tive response in 5 cm water-depth appeared at reduction division stage and in 20 cm depth at panicle formation stage. Secondary branches and spikelets were increased in number by deep irrigation with normal temperature water, but decreased and degenerated by deep irrigation with cold water at panicle formation stage resulting in high spikelet sterility and low grain filling. Deep irrigation with normal temperature water increased the contents of total nitrogen, phosphate, potassium and silicate in leaf blades, branches and chaff. However, cold water irrigation reduced the uptake of phosphate, potassium and silicate except nitrogen particularly in deep irrigation. Ratios of phosphate, potassium and silicate to total nitrogen content were decreased by cold water irrigation. Branches seemed to have higher requirements for phosphate, potassium and silicate than leaf blades and chaff. Silicate-to-total nitrogen ratio in leaf blades, branches and chaff had significant correlations with yield showing closer relationship between yield and the ratio of silicate to total nitrogen in branches in particu-lar.

• Development and Reproduction
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• v.21 no.4
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• pp.407-415
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• 2017

In the present study, we investigated the role of binding immunoglobulin protein/glucose-regulated protein, 78-kDa (BIP/GRP78)-regulated endoplasmic reticulum (ER)-stress on meiotic maturation and cumulus cells expansion in porcine cumulus-oocyte complexes (COCs). Previously, it has been demonstrated that unfolded protein response (UPR)-related genes, such as molecules involved in ER-stress defense mechanisms, were expressed in matured oocytes and cumulus cells during in vitro maturation (IVM) of porcine oocytes. However, BIP/GRP78-mediated regulation of ER stress in porcine oocytes has not been reported. Firstly, we observed the effects of knockdown of BIP/GRP78 (an UPR initiation marker) using porcine-specific siRNAs (#909, #693, and #1570) on oocyte maturation. Among all siRNAs, siRNA #693 significantly reduced the protein levels of UPR marker proteins (BIP/GRP78, ATF4, and P90ATF6) in porcine COCs observed by Western blotting and immunofluorescence analysis. We also observed that the reduction of BIP/GRP78 levels by siRNA#693 significantly inhibited the meiotic maturation of oocytes (siRNA #693: $32.5{\pm}10.1%$ vs control: $77.8{\pm}5.3%$). In addition, we also checked the effect of ER-stress inhibitors, tauroursodeoxycholic acid (TUDCA, $200{\mu}M$) and melatonin ($0.1{\mu}M$), in BIP/GRP78-knockdown oocytes. TUDCA and melatonin treatment could restore the expression levels of ER-stress marker proteins (BIP/GRP78, $p-eIF2{\alpha}$, $eIF2{\alpha}$, ATF4, and P90ATF6) in siRNA #693-transfected matured COCs. In conclusion, these results demonstrated that BIP/GRP78-mediated regulation of UPR signaling and ER stress plays an important role in in vitro maturation of porcine oocytes.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.259-270
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• 2001

The present study was attempted to investigate the characteristics of epibatidine on secretion of catecholamines (CA) from the isolated perfused model of the rat adrenal gland, and to establish the mechanism of action. Epibatidine $(3{\times}10^{-8}\;M)$ injected into an adrenal vein produced a great inhibition in secretory response of CA from the perfused rat adrenal gland. However, upon the repeated injection of epibatidine $(3{\times}10^{-8}\;M)$ at 15 min-intervals, CA secretion was rapidly decreased after second injection of epibatidine. However, there was no statistical difference between CA secretory responses of both 1st and 2nd periods by the successive administration of epibatidine at 120 min-intervals. Tachyphylaxis to releasing effects of CA evoked by epibatidine was observed by the repeated administration. Therefore, in all subsequent experiments, epibatidine was not administered successively more than twice only 120 min-intervals. The epibatidine-induced CA secretion was markedly inhibited by the pretreatment with atropine, chlorisondamine, pirenzepine, nicardipine, TMB-8, and perfusion of $Ca^{2+}-free$ Krebs solution containing EGTA, while was not affected by diphenhydramine. Moreover, the CA secretion evoked by ACh for 1st period $(0{\sim}4\;min)$ was greatly potentiated by the simultaneous perfusion of epibatidine $(1.5{\times}10^{-8}\;M),$ but followed by time-dependently gradual reduction after 2nd period. The CA release evoked by high potassium $(5.6{\times}10^{-8}\;M),$ for 1st period $(0{\sim}4\;min)$ was also enhanced by the simultaneous perfusion of epibatidine, but those after 2nd period were not affected. Taken together, these experimental data suggest that epibatidine causes catecholamine secretion in a calcium dependent fashion from the perfused rat adrenal gland through activation of neuronal cholinergic (nicotinic and muscarinic) receptors located in adrenomedullary chromaffin cells. It also seems that epibatidine-evoked catecholamine release is not relevant to stimulation of histaminergic receptors.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.288-295
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• 2018

Purpose: The paper aims to compare the effectiveness of the two types of transport demand management measures, namely pull measures and push measures. Method: Case studies of two metropolitan areas in the developing world assess the extent to which increases in fuel prices can contribute to reducing automobile use and increasing the public transport use and the potential of urban rail transit to cause mode shift from automobiles. Within the case studies, a stated response survey of current car users has been conducted for Cairo and an on-line survey of rail transit users in Algiers. Results: There was a major proportion of car drivers who intend to switch to public transport, depending on the range of fuel prices in Cairo and a considerable proportion of rail users who have switched from automobiles resulting in a measurable reduction in CO2 emissions in Algiers. Conclusion: Investments in urban rail can be highly effective where there are demands for better public transport, but this type of pull measures can be much more effective if combined with push measures which significantly raise driving costs.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.143-150
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• 2009

Deicing salt is used to melt snow and ice on the road for traffic safety during the winter season, which accumulates in the roadside vegetation and induces visible injuries. The damage may accelerate particularly when it coincides with early spring leaf out. In order to better understand the response mechanisms, C. kousa (3-year-old) was irrigated twice prior to leaf bud in a rhizosphere with solutions of 0.5, 1.0, and 3.0% calcium chloride ($CaCl_2$) concentration, that were made by using an industrial $CaCl_2$ reagent practical deicing material in Seoul. Physiological traits of the mature leaves were progressively reduced by $CaCl_2$ treatment, resulting in reductions of total chlorophyll contents, chlorophyll a:b, photosynthetic rate, quantum yield, stomatal conductance, $F_V/F_M$, and NPQ. On the contrary, light compensation point and dark respiration were increased at high $CaCl_2$ concentration. A decrease in intercellular $CO_2$ concentration by stomatal closure first resulted in a reduced photosynthetic rate and then was accompanied by low substance metabolic rates and photochemical damage. Based on the reduction of physiological activities at all treatments ($CaCl_2$ 0.5%, 1.0%, and 3.0%), C. kousa was determined as one of the sensitive species to $CaCl_2$.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.192-198
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• 2009

This study was carried out in order to determine in vitro biocompatibility of white mineral trioxide aggregate (MTA), and to compare it with that of the commonly used materials, i. e. calcium hydroxide liner (Dycal), glass ionomer cement (GIC), and Portland cement which has a similar composition of MTA. To assess the biocompatibility of each material, cytotoxicity was examined using MG-63 cells. The degree of cytotoxicity was evaluated by scanning electron microscopy (SEM) and a colorimetric method, based on reduction of the tetrazolium salt 2,3 bis {2methoxy 4nitro 5[(sulfenylamino) carbonyl] 2H tetrazolium hydroxide} (XTT) assay. The results of SEM revealed the cells in contact with GIC, MTA. and Portland cement at 1 and 3 days were apparently healthy. In contrast, cells in the presence of Dycal appeared rounded and detached. In XTT assay, the cellular activities of the cells incubated with all the test materials except Dycal were similar, which corresponded with the SEM observation. The present study supports the view that MTA is a very biocompatible root perforation repair material. It also suggests that cellular response of Portland cement and GIC are very similar to that of MTA.