• The Korean Journal of Malacology
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• v.27 no.1
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• pp.15-27
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• 2011

This study was performed to observe ultrastructure of the gill and to ascertain the effect of salinity on histopathological and ultrastructural changes in the gill of the Japanese clam, Corbicula japonica. Experimental period was 7 days. Experimental groups consisted of control, 5, 10, 20 psu. $LC_{50}$ (96 h.) by the probit was 19.55 psu. Mortality was significantly different from the control (p < 0.05). Inner demibranch of the gill of C. japonica was wider 1.37 times than outer demibranch (p < 0.001). The filament zone on the plica can be distinguished by the six epithelial celll cell; frontal ciliated epithelium ($7{\mu}m$), latero-frontal ciliated epithelium ($5{\mu}m$), postlatero-frontal epithelim ($3{\times}8{\mu}m$), and lateral ciliated epithelium ($5{\mu}m$) in the frontal zone, endothelial cellin the intermediate zone, and abfrontal cell in the abfrontal zone. It had one type of secretory cell that was filled with fibrous substances of low electron density. The gill of C. japonica exposed to 5 psu for 7 days was observed partially disappearance of the cilia, and glycogen granule in the filament. In the 10 psu, gill appeared partially modification of epithelial cell and destruction of the glycocalyx. Gill exposed to 20 psu was extended nuclus of the ciliated epithelial cell, destruction of the organelles, and observed glycogen granules infiltration and numerous vacuoles. Moreover, more than 50% filaments were observed that come out chitinous rod from disappearance of epithelial cell in the filament. Therefore, the destruction of the cilia and epithelial cell induce physiological activity and it may be leading directly to death.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.277-283
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• 2002

In the present study, adverse effects of megadose of dietary perilla oil were investigated in an experimental model consisted of 6 groups of Wistar rats. To compare the adverse effects of megadose perilla oil with different kind of dietary fat, rats were fed one of the following diets for one month: 10% beef tallow (B$_1$B), 10% corn oil (C$_1$B), 10% perilla oil (P$_1$B), 20% beef tallow (B$_2$B), 20% corn oil (C$_2$B), and 20% perilla oil (P$_2$B) diet. The body weight gain rate seemed to be more affected by the size of fat contents than the species of fat in the diet, so the body weight gain rate of 20% fat groups were significantly higher than those of 10% fat groups in spite of the larger amount of flood intake in 10% fat groups than in 20% fat groups. The levers of plasma triglyceride and total-cholesterol in 20% fat groups were significantly increased in dose dependent fashion when compared to 10% groups, the values of beef tallow (B$_2$B) group being the highest among all groups. Plasma glutainic pyruvic transferase activities and level of blood urea nitrogen had a tendency to increase along with increase of fat contents (%) in diets, the values of P$_2$B group, the highest among all groups, being beyond the normal levers. The plasma carbon dioxide concentration of P$_2$B group was the highest in all groups and exceeded the normal value, there being no significant difference among the plasma carbon dioxide concentration of others groups. The results showed that large dose and long term intake of dietary perilla oil had some adverse effects on hepatic and other organic functions in rats.

• The Korean Journal of Financial Management
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• v.26 no.3
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• pp.103-138
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• 2009

In this article we examine a unique data set of intraday fair disclosure(FD) releases to shed light on market efficiency within the trading day. Specifically, this paper analyze the response of stock prices on fair disclosure disseminated in real-time through KIND(Korea Investor's Network for Disclosure) on Korea stock exchange during the period from January 2003 to September 2004. We find that the prices of stock experiences a statistically and economically significant increase beginning seconds after the fair disclosure is initially announced and lasting approximately two minutes. The stock price responds more strongly to fair disclosure on smaller firm but the response to fair disclosure on the largest firm stock is more gradual, lasting five minutes. We also examine the profitability of a short-term trading strategy based on dissemination of fair disclosure. After controlling for trading costs we find that trader who execute a trade following initial disclosure generate negative profits, but trader buying stock before initial disclosure realize statistically significant positive profit after two minute of disclosure. Summarizing overall results, our evidence supports that security prices on Korea stock exchange reflects all available information within two minutes and the Korea stock market is semi-strongly efficient enough that a trader cannot generate profits based on widely disseminated news unless he acts almost immediately.

• Korean Journal of Social Welfare
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• v.59 no.1
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• pp.199-221
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• 2007

This study examines the conditions and causes of income inequality and seeks assignments for mitigating income inequality. An analysis of the conditions and causes of income inequality is summarized as follows. First, income inequality, which rapidly increased after the economic crisis, increased and reduced repeatedly during 1999-2004, and remained a level in 2005 as high as that of the year directly after the economic crisis. Second, an analysis of the causes of income inequality by utilizing the long-term data(1985-2004) shows that unemployment rate, nonstandard employment rate, and the rising rate of land prices positively affect income inequality. Third, an analysis of the causes of income inequality by utilizing the data before and after the economic crisis(1995-2004) demonstrates that unemployment rate, nonstandard employment rate, and the workers' income ratio between large enterprises and small enterprises positively affect income inequality. Fourth, the rising rate of land prices which significantly affects income inequality in the data of 1985-2004 does not affect income equality in the data of 1995-2004, and the workers' income ratio between large enterprises and small enterprises which does not affect income inequality in the data of 1985-2004 significantly affect income equality in the data of 1995-2004. These results suggest several implications for mitigating income inequality. First, alternative plans to reduce unemployment rate must be prepared. Second, policies to reduce nonstandard employment rate should be established. Third, programs to stabilize or lower the land prices must be deliberated. Fourth, a master-plan to support small to medium enterprises must be carried out in order to reduce the wage differentials between large enterprises and small to medium enterprises.

• The Korean Journal of Zoology
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• v.24 no.3
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• pp.133-144
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• 1981

The ultrastructures of the pigment cells in the Asiatic land salamander (Hynobius leechi) dorsal skin were obtained by means of electron microscope. The results were as follows; 1. The pigment cells of the epidermis consisted of the melanocytes in the germinal layer and of the melanophores distributing to the keratinocyte layer. The traits of these cells in the epidermis were as follows: A. The nuclei of the melanocytes were round or oval in shape and appeared as partly small or large infoldings of the nuclear envelope. B. Rough-surfaced endoplasmic reticulums and Golgi complexes were well developed in infranuclear cytoplasm. Many ribosomes were mainly distributed around the perinuclear portion. C. The melanosomes of the melanocytes were observed as a found or an oval shape and strong electron-dense or less electron-dense melanosomes were observed. D. The infoldings of the nuclear envelope in the melanophore were partly found deeper than those of the melanocyte. The cytoplasm of the melanophore filled with melanosomes caused organelles not to be observed in that. 2. The pigment cells in the dermis were composed of the xanthophores just beneath basement membrane and the melanophores in the connective tissue. The traits of these cells in the dermis were as follows: A. The xanthophores contained round or oval vesicles, and these vesicles were divided into 6 types (type I pterinosome, type II pterinosome, type III pterinosomes, type iv pterinosome, type V pterinosome, type VI pterinosome). B. Most of the nuclei of the melanophores in the dermis were elongate in shape, and a portion of the nuclear envelope was deep infolded. C. Becuase the cytoplasm was filled with the melanosomes of the same electron-density, organelles were not observed in the cytoplasm. D. Two processes of the melanophore in the dermis extended in parallel with a xanthophore and the cytoplasm in those processes were filled with the melanosomes.

• Journal of Life Science
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• v.26 no.8
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• pp.963-969
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• 2016

Kinesin superfamily proteins (KIFs) are microtubule-dependent molecular motor proteins essential for the intracellular transport of organelles and protein complexes in cells. Kinesin 1 is a member of those KIFs that transport various cargoes, including organelles, synaptic vesicles, neurotransmitter receptors, cell signaling molecules, and mRNAs through interaction between its light chain subunit and the cargoes. Kinesin light chains (KLCs) are non-motor subunits that associate with the kinesin heavy chain (KHC) dimer. KLCs interact with many different binding proteins, but their particular binding proteins have not yet been fully identified. We used the yeast two-hybrid assay to identify proteins that interact with the tetratricopeptide repeat (TPR) domain of KLC1. We found an interaction between the TPR domain of KLC1 and Wiskott-Aldrich syndrome protein family member 1 (WAVE1), a member of the WASP/WAVE family involved in regulation of actin cytoskeleton. WAVE1 bound to the six TPR domain-containing regions of KLC1 and did not interact with KHCs (KIF5A, KIF5B, and KIF5C) in the yeast two-hybrid assay. The carboxyl (C)-terminal verprolin-cofilin-acidic (VCA) domain of WAVE1 is essential for interaction with KLC1. Also, other WAVE isoforms (WAVE2 and WAVE3) interacted with KLC1 in the yeast two-hybrid assay. When co-expressed in HEK-293T cells, WAVE1 co-localized with KLC1 and co-immunoprecipitated with KLC1 and KIF5B. These results suggest that kinesin 1 motor protein may transport WAVE complexes or WAVE-coated cargoes in cells.

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.531-538
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• 2007

A total of 127 Korean native black pigs(gilt 30, boar 97) were used to investigate the carcass properties, yields of retail cut and meat quality. The average live weight, chilled carcass percentage and retail cut percentage used in this study were 74.69kg, 71.14% and 61.09% for boar, and 75.5kg, 73.88% and 56.25% for gilt, respectively. Although gilts were higher in live weight and chilled carcass percentage whereas lower in retail cut percentage when compared to boars, there was no significantly difference between gender(p<0.05). Gilts had higher fat contents than boars regardless of weight range groups. Protein contents increased as slaughter weight increased for gilt and boar groups. Gilts contained high intramuscular fat contents had significantly lower Warner-Bratzler shear force(WBS) and water holding capacity(WHC) when compared to boar in the same weight range group(p<0.05). There was no significantly different in meat color(p>0.05) although gilts had higher L(lightness), a(redness) and b(yellowness) values when compared to the same group of boar. From the result of this study can be used for the grading guideline and quality evaluation standard of Korean native black pigs by gender and live weight.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.7-14
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• 1998

In order to understand the action mechanism of polyhexamethylene biguanide (PHMB) to the cyst of Accnthcnloebc on the morphological basis, the cysts of four corneal isolates of Acanthanoebc were treated with minimal cysticidal concentration (MCC) of PHMB and their ultrastructural changes were examined by transmission electron microscopy. The most striking change of cysts treated with PHMB compared with normal cysts was the shrinkage of intracystic amoebae, which resulted in the separation of the plasma membrane of intracystic amoeba from endocystic wall. Subplasmalemmal lipid droplets became irregularly shaped . In severely damaged cysts, cytoplasm was aggregated and organelles were severely deformed. Cytoplasmic materials were leaked out through the damaged plasma membrane. Most cysts showed aggregation of nuclear chromatin material. Number of mitochondrial cristae was also reduced. Ecto- and endo-cystic walls were relatively well tolerated. Findings in the present study revealed that PHMB affected mainly on plasma membrane, but lesser on organellar membrane of intracystic amoeba. It seemed likely that PHMB might kill cystic forms of Accnthamoebc by similar mechanism in which this environmental biocide can damage the cell wall of Escherichia coli by binding with acidic phospholipids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.111-120
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• 1991

In order to investigate the cellular peroxidative damage due to heated oil intake and the preventive effect of vitamin E on it rats were fed heated corn oil with acid value of 4.02 at the level of 10 Cal% and three different levels of vitamin E that were 0, 40 and 200 mg/kg diet. Control group was fed fresh corn oil and 40mg/kg diet of vitamin E. After ech feeding period of 0, 3 and 6 weeks, liver superoxide dismutase (SOD), glutathione peroxidase (GPX) activities and microsomal content of vitamin E and lipid peroxide (LPO) were measured as well as cellular morphology was examined. SOD activities and LPO contents were higher, while GPX activities and vitamin e contents were lower in heated oil groups than control group. Electromicroscopic observation revealed the loss of inner mitochondrial membrane and cristae and irregular arrangement of nuclear membrane and chromatin in heated oil groups. As dietary vitamin e level was increased, SOD activity and LPO content were decreased, but GPX activity and vitamin E content in the liver increased and cellular peroxidative damage reduced progressively. This phenomena was more remarkable in 6 weeks of feeding than 3 weeks.

• Journal of the Economic Geographical Society of Korea
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• v.24 no.3
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• pp.283-299
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• 2021

As the intelligent revolution triggered by digital technology, unmanned vehicles such as self-driving cars, robots, and drones appeared, which brought about innovative changes in the industry. Gyeonggi Local government has established both an ordinance and a basic plan regarding unmanned vehicles. It is time to prepare a data-based policy by understanding the current state of the unmanned vehicle industry in the province. As a result of the survey, the unmanned vehicle industry in Gyeonggi Province is 25% of the nationwide, and more than 88% is concentrated in the southern part of Gyeonggi Province. The land sector such as the robot and autonomous vehicles are focused on 71.4% and the aviation sector such as drones are 26.7%. However, unmanned vehicle companies in Gyeonggi-do are mostly small-sized businesses with less than 10 years of experience and are in the stage of introduction and growth level. They have a plan to improve technology through continuous R&D by hiring human resources. Therefore, Gyeonggi-do needs to consider policy support for sustainable growth of start-up and small enterprises and for fostering professional manpower and technical skills as well as for establishing an unmanned vehicle industry network to create, share, and spread knowledge.