• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.161-168
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• 1986

A 1.95Kb Sau3Al fragment coding for $\alpha$-amylase from Bacillus amyloliquefaciens was isolated by the shotgun method using Escherichia coli as a host. The genome of Bacillus amyloliquefaciens was partially digested with the restriction endonuclease Sau3Al and joined to plasmid YRp7 cleaved with the restriction endonuclease BamHI. The $\alpha$-amylase gene present in a 1.95Kb insert was stably maintained and expressed in Escherichia coli. The amount of $\alpha$-amylase activity produced by Escherichia coli containing the hybrid plasmid pEA24 was about 65% of the activity produced by the donor Bacillus amyloliquefaciens strain. The properties of $\alpha$-amylase produced by Escherichia coli were very similar to those produced by Bacillus amyloliquefaciens as based on optimum temperature, pH, and effect of CaCl$_2$ concentration. About 70% of the $\alpha$-amylase produced by Escherichia coli was localized in the periplasmic space, whereas the remaining enzyme was localized in the inner part of the cell.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.414-419
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• 1996

The xylnX gene encoding a xylanase from Clostridium thermocellum ATCC27405 was cloned in the plasmid pJH27, an E. coli-Bacillus shuttle vector and the resultant recombinant plasmid, pJX18 was transformed into E. coli HB101. The overexpressed xylanase was found to be secreted into the periplasmic space of the recombinant E. coli cells. The crude enzyme was obtained by treating the E. coli cells with lysozyme, and purified by DEAE-Sepharose column chromatography. Molecular wieght of the xylanase was estimated to be 53 kDa by gel filtration. The pI value was determined to be pH 8.8. The N-terminal sequence of the enzyme protein was Asp-Asp-Asn-Asn-Ala-Asn-Leu-Val-Ser-Asn which was considered to be the sequence of that of the mature form protein. The Km value of the enzyme for oat spelt xylan was calculated to be 2.63 mg/ml and the Vmax value was $0.47 {\mu}mole/min$. The xylanase had a pH optimum for its activity at pH 5.4 and a temperature optimum at $60^{\circ}C$. The enzyme hydrolyzed xylan into xylooligosaccharides which were composed mainly of xylobiose (40%) and xyloltriose (12%) after 5 hour reaction. This result indicates that the xylanase from C. thermocellum ATCC27405 is an endo-acting enzyme.

• Korean Journal of Family Social Work
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• no.55
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• pp.265-297
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• 2017

This study aims to provide basic information about the policy and system improvements relevant to single elderly men, through an investigation concerning the use and needs of activity spaces near their housing environments. Eighteen single elderly men over 60-years-old living in Gunsan city of Jeonbuk province in Korea participated in in-depth interview, and the data were qualitatively analyzed. The results of the study are as follows: The social networks of the participants were focused on friends or colleagues, while mutual exchanges with their children were intermittently undertaken. Natural networks of the elderly were formed mainly in third places, such as parks, restaurants, or community facilities, and about a half of the elderly participants had no spatial needs, and the rest required spaces for meal services, the elderly living community, jobs, leisure/hobby activities, or facility improvements. The elements influencing use of activity spaces were access from the residence, health, social networks, and economic conditions. The results suggest the following: Exercise or leisure facilities supporting elderly mobility should be set up close to their residential environments. Senior facilities centered on systematic supports and shuttle buses circulating around the places that the elderly visit frequently should be considered. On the other hand, regular maintenance and education on residents' proper use of the facilities, and sufficient information and fee discounts for the general programs are needed so that the elderly could interact with the younger generation. From a public perspective, a rational system and policy based on understanding single elderly men's needs should be prepared for provision and management of the activity space.

• The Korean Journal of Air & Space Law and Policy
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• v.19 no.2
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• pp.97-136
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• 2004

The Northeast Asian air cargo market has expanded tremendously as a result of the opening up of the Chinese market. The importance of the Asia-Pacific region in the global air transport has also increased. The exchange of human and material resources, services, and information in Northeast Asia, which is expected to increase in the near future, requires that the airlines operating within this region adopt a more liberalized approach. This paper introduced alternatives which can be applied to the Northeast Asian airlines industry so as to bring about the integration of regional air transport: First, this paper found a need for individual Northeast Asian nations to alter their policies towards the airlines industry. Second, each country should further liberalize their respective domestic air transport. Third, there is a need for freer air service agreements to be signed between the nations of Northeast Asia. Fourth, the strategic alliances between the airlines operating in Northeast Asia should be further strengthened. Fifth, this liberalization process should be carried out in an incremental manner, beginning with more competitive airports and routes, or with less-in-demand routes. Sixth, there is a need for a shuttle system to be put into place between the main airports in China, Korea, and Japan. Seventh, these three nations jointly develop aviation safety and security systems that are in accordance with international standards. Eighth, the liberalization process of the aviation industry should be undertaken in conjunction with other related fields. Ninth, organizations linking together civil aviation organization in the Asia-Pacific area should be formed, as should each government linking together. By doing so, these countries will be able to establish regular venues through which to exchange opinions on the integration and liberalization of the air cargo market so as to induce the gradual liberalization of the actual market. The liberalization of the air transport in Northeast Asia will prove to be a daunting task in the short term. However, if the Chinese airlines continue to exhibit continuous growth and Japanese airlines are able to complete their move towards a low-cost structure, this process could be completed earlier than expected. Over the last twenty five years the air transport has undergone tremendous changes. The most important factor behind these changes has been the increased liberalization of the market. As a result, rates have decreased while demand has increased. This has resulted in turning the air transport industry, which was long perceived as an industry in decline, into a high-growth industry. The only method of increasing regional exchanges in the air transport is to pursue further liberalization. The country which implements this liberalization process at the earliest date may very well emerge as a leading force within the air transport industry.