Proceedings+of+the+National+Academy+of+Science
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Scaling Laws between Population and Facility Densities Found
A research team led by Prof. Ha-Woong Jeong of the Department of Physics, KAIST, has found a positive correlation between facilities and population densities, university authorities said on Tuesday (Sept. 2). The research was conducted in the cooperation with a research team of Prof. Beom-Jun Kim at Sungkyunkwan University.
The researchers investigated the ideal relation between the population and the facilities within the framework of an economic mechanism governing microdynamics.
In previous studies based on the global optimization of facility positions in minimizing the overall travel distance between people and facilities, the relation between population and facilities should follow a simple law. The new empirical analysis, however, determined that the law is not a fixed value but spreads in a broad range depending on facility types.
To explain this discrepancy, the researchers proposed a model based on economic mechanism that mimics the competitive balance between the profit of the facilities and the social opportunity cost for population.
The results were published in the Proceedings of the National Academy of Sciences of the United States on Aug. 25.
2009.09.04 View 11950 -
Maximum Yield Amino Acid-Producing Microorganism Developed with use of System Biotechnology
Maximum Yield Amino Acid-Producing Microorganism Developed with use of System Biotechnology
A team led by Sang-Yup Lee, a distinguished professor of Chemical and Biomolecular Engineering and chair professor of LG Chemical, has succeeded in developing maximum yield L-valine-producing microorganism by using System Biotechnology methods. The research results will be published at the April fourth week (April 23 - 27) edition of the Proceedings of the National Academy of Sciences (PNAS) of the USA.
Prof. Lee’s team has developed maximum yield amino acid-producing microorganism (target substance of L-valine, an essential amino-acid) by using microorganism E cell system and simulation methods.
His team produced initial producing microorganism by selectively operating necessary parts in colon bacillus genome and excavated preliminary target gene which is to newly be operated through transcriptome analysis using DNA chips. Then they performed a great amount of gene deletion experiment on computer by using MBEL979, E-cells of colon bacillus, and excavated secondary engineering targets. And they finally succeeded in developing maximum yield valine-producing microorganism that can extract 37.8 grams of valine from 100 grams of glucose by applying experiment results to the actual development of microorganism so as to achieve the optimization of metabolic flux in cells,
Prof. Lee said, “Since successfully used for the development of microorganism on a systematic system level, system biotechnology methods are expected to significantly contribute to the development of all biotechnology-relevant industries. At the beginning, we had huge obstacles in fusing IT and BT, but my team mates cleverly overcame such obstacles, hence I’m very proud of them.” The producing microorganism and its developing methods are pending international applications (PCT).
2007.04.26 View 13579