• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.916-920
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• 2005

Acetohydroxy acid synthase catalyzes the first common step in the biosynthesis of branched chain amino acids. AHAS plays two distinct metabolic roles, and is designated as anabolic AHAS and catabolic AHAS, depending on its function. Anabolic AHAS is FAD-dependent, while its catabolic counterpart is not. In this work, a conserved motif was identified in the $\beta$-domain of anabolic AHASs, but not in catabolic AHAS ($_{372}RFDDR_{376}$). In order to determine the functions of this motif, we replaced the motif with the corresponding sequence in FAD-independent AHAS, SPVEY. None of these three mutants (SPV, SPVE, and SPVEY) was detected with bound FAD. However, two of these mutants (SPVE and SPVEY) were active at a low level of specific activity. Although they exhibited pyruvate- and ThDP- dependent characteristics, the activity of the two active mutants appears to be FAD-independent. The SPVEY mutant was completely insensitive to the three tested herbicides, even at extremely high concentrations and is also somewhat more thermolabile than the wild type enzyme. The data provided in this work suggest that the RFDDR motif is a possible determinant of the FAD-dependent and herbicide-resistant properties of tobacco AHAS. The SPVEY mutant appears to exhibit catabolic AHAS-like activity.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.669-672
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• 2013

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.201-210
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• 2007

Soybean [Glycine max(L.) Merr.] oil is versatile and used in many products. Modifying the fatty acid profile would make soy oil more functional in food and other products. The ideal oil with the most end uses would have saturates(palmitic + stearic acids) reduced from 15 to < 7%, oleic acid increased from 23 to > 55%, and linolenic acid reduced from 8 to < 3%. Reduced palmitic acid(16:0) is conditioned by three or more recessive alleles at the Fap locus. QTLs for reduced palmitic acid have mapped to linkage groups(LGs) A1, A2, B2, H, J, and L. Genes at the Fad locus control oleic acid content(18:1). Six QTLs($R^2$=4-25%) for increased 18:1 in N00-3350(50 to 60% 18:1) explained four to 25% of the phenotypic variation. M23, a Japanese mutant line with 40 to 50% 18:1 is controlled by a single recessive gene, ol. A candidate gene for FAD2-1A can be used in marker-assisted breeding for high 18:1 from M23. Low linolenic acid(18:3) is desirable in soy oil to reduce hydrogenation and trans-fat accumulation. Three independent recessive genes affecting omega-3 fatty acid desaturase enzyme activity are responsible for the lower 18:3 content in soybeans. Linolenic acid can be reduced from 8 to about 4, 2, and 1% from copies of one, two, or three genes, respectively. Using a candidate gene approach perfect markers for three microsomal omega-3 desaturase genes have been characterized and can readily be used in for marker assisted selection in breeding for low 18:3.

• Journal of the Korea Fashion and Costume Design Association
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• v.10 no.1
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• pp.135-144
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• 2008

The reason that we are familiar with fashion from the 1950s is because of the work such as New Look done by a french fashion designer, Christian Dior who had taken on an almost mythical significance by his name. Moreover, in the sense of popularity, the appearance of Marilyn Monroe and Audrey Hepburn, two typical Hollywood actresses who each has directly-opposed image, is the symbol of youthful America of the 1950s and represents the remarkable start of the American fashion. Still, these days designers and mass medias recall the fashion from the 50s remaking and parodying it to suit public's taste. Being due to the World War II, Europe suffered not only the loss of its national tradition and reputation but also got a fatal blow politically and economically. On the other hand, the United States of America occupied a primary position in the world and outstandingly became the most powerful country. The American fashion of the 1950s represents youth and newness and rejects outdated and outmoded style. In this period, appears the indication which announces previously the youth culture. Poodle skirt is the fashion item that acquired popularity among young american women and girls in the late 1950s. In effect, it is the fashion as American as apple pie. A costly A-line skirt had been transformed into a cheap felt skirt. Instead of a real poodle dog which was carried by French women like an accessory, they embroidered a poodle dog on the lower edge of their skirt. As deriding the snobbish gait, they swayed themselves frantically to the rhythm of Rock n' Roll which swept those days. This was an attitude of young Americans against the existing trend of Europe. Poodle skirt showed the free spirit and intention of young people unbound to custom and established vogue. In addition, in the aspect of comprising the American spirit of independent, pioneer, and subjective American people, it goes beyond the bounds of common concept of fad. Poodle skirt is an unique symbol of the 1950s' American fashion which prognosticates the advent of the United States and the success in modern fashion world which was changing after 1950s.

• Information Systems Review
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• v.11 no.1
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• pp.161-179
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• 2009

Nowadays an increasing number of Internet users are running individual websites as Blog or Cyworld. As this type of personal media has a great influence on communication among people, business comes to care about Network Effect, Network Software, and Social Network. For instance, Cyworld created the web service called 'Minihompy' for individual web-logs, and acquired 2.4milion users in 2007. Although many people assumed that the popularity of Minihompy, or Blog would be a passing fad, Cyworld has improved its service, and expanded its Network with various contents. This kind of expansion reflects survival efforts from infinite competitions among ISPs (Internet Service Provider) with focus on enhancing usability to users. However, Cyworld's Network Effect is gradually diminished in these days. Both of low production cost of service vendors and the low searching/conversing costs of users combine to make ISPs hard to keep their market share sustainable. To overcome this lackluster trend, Cyworld has adopted new strategies and try to lock their users in their service. Various efforts to improve the continuance and expansion of Network effect remain unclear and uncertain. If we understand beforehand how a service would improve Network effect, and which service could bring more effect, ISPs can get substantial help in launching their new business strategy. Regardless many diverse ideas to increase their user's duration online ISPs cannot guarantee 'how the new service strategies will end up in profitability. Therefore, this research studies about Network effect of Cyworld's 'Minihompy' using System-Dynamics method which could analyze dynamic relation between users and ISPs. Furthermore, the research aims to predict changes of Network Effect based on the strategy of new service. 'Page View' and 'Duration Time' can be enhanced for the short tenn because they enhance the service functionality. However, these services cannot increase the Network in the long-run. Limitations of this research include that we predict the future merely based on the limited data. We also limit the independent variables over Network Effect only to the following two issues: Increasing the number of users and increasing the Service Functionality. Despite of some limitations, this study perhaps gives some insights to the policy makers or others facing the stiff competition in the network business.