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KAIST Professor Finds Paradox in Human Behaviors on Road
-Strange as it might seem, closing roads can cut delays A new route opened to ease traffic jam, but commuting time has not been reduced.Conversely, motorists reached their destinations in shorter times after a big street was closed. These paradoxical phenomena are the result of human selfishness, according to recent findings of a research team led by a KAIST physics professor. Prof. Ha-Woong Jeong, 40, at the Department of Physics, conducted a joint research with a team from Santa Fe Institute of the U.S. to analyze the behaviors of drivers in Boston, New York and London. Their study found that when individual drivers, fed with traffic information via various kinds of media, try to choose the quickest route, it can cause delays for others and even worsen congestion. Prof. Jeong and his group"s study will be published in the Sept. 18 edition of the authoritative Physical Review Letters. The London-based Economist magazine introduced Prof. Jeong"s finding in its latest edition. Prof. Jeong, a pioneer in the study of "complex system," has published more than 70 research papers in the world"s leading science journals, including Nature, PNAS and Physical Review Letters. "Initially, my study was to reduce annoyance from traffic jam during rush hours," Prof. Jeong said. "Ultimately, it is purposed to eliminate inefficiency located in various corners of social activities, with the help of the network science." The Economist article read (in part): "...when individual drivers each try to choose the quickest route it can cause delays for others and even increase hold-ups in the entire road network. "The physicists give a simplified example of how this can happen: trying to reach a destination either by using a short but narrow bridge or a longer but wide motorway. In their hypothetical case, the combined travel time of all the drivers is minimized if half use the bridge and half the motorway. But that is not what happens. Some drivers will switch to the bridge to shorten their commute, but as the traffic builds up there the motorway starts to look like a better bet, so some switch back. Eventually the traffic flow on the two routes settles into what game theory calls a Nash equilibrium, named after John Nash, the mathematician who described it. This is the point where no individual driver could arrive any faster by switching routes. "The researchers looked at how this equilibrium could arise if travelling across Boston from Harvard Square to Boston Common. They analysed 246 different links in the road network that could be used for the journey and calculated traffic flows at different volumes to produce what they call a “price of anarchy” (POA). This is the ratio of the total cost of the Nash equilibrium to the total cost of an optimal traffic flow directed by an omniscient traffic controller. In Boston they found that at high traffic levels drivers face a POA which results in journey times 30% longer than if motorists were co-ordinated into an optimal traffic flow. Much the same thing was found in London (a POA of up to 24% for journeys between Borough and Farringdon Underground stations) and New York (a POA of up to 28% from Washington Market Park to Queens Midtown Tunnel). "Modifying the road network could reduce delays. And contrary to popular belief, a simple way to do that might be to close certain roads. This is known as Braess’s paradox, after another mathematician, Dietrich Braess, who found that adding extra capacity to a network can sometimes reduce its overall efficiency. "In Boston the group looked to see if the paradox could be created by closing any of the 246 links. In 240 cases their analysis showed that a closure increased traffic problems. But closing any one of the remaining six streets reduced the POA of the new Nash equilibrium. Much the same thing was found in London and New York. More work needs to be done to understand these effects, say the researchers. But even so, planners should note that there is now evidence that even a well intentioned new road may make traffic jams worse."
New System to Generate Extreme-Ultraviolet Light Developed
A KAIST research team led by Prof. Seung-Woo Kim of the Mechanical Engineering Department developed a new system for generating coherent extreme-ultraviolet (EUV) light, school authorities announced on June 5. The new system comes in a metallic nano-structure consisting of a two-dimensional array of gold "bow tie" elements on a sapphire plate. The new process was featured in the British journal Nature on June 5. The properties of coherent EUV light make it a prime candidate for exciting technological applications. But, at present, the equipment needed to generate the short-wavelength light is costly and bulky. The system developed by Prof. Kim"s research team is expected to reduce both cost and bulk. The new system uses the conventional principle of high-harmonic generation via the interaction of a femtosecond laser pulse with a gas, but adopts the novel concept of amplifying light by way of local plasmon field enhancement, according to the research team.
Professor Sang-Yup Lee publishes a requested paper in Nature Biotechnology
Professor Sang-Yup Lee publishes a requested paper in Nature Biotechnology “The era of commercialized bioplastic is coming” Disclose an opinion as specialist at a requested paper in Nature Biotechnology, October 2006 A team led by Barbel Friedrich, Professor of Humboldt-Universitat zu Berlin, and Alexander Steinbuchel, Professor of West falische Wilhelms-Universitat Munster, found out the entire genome sequence of the typical bioplastic-producing microorganism ‘Ralstonia eutropha’ and published a paper on it in Nature Biotechnology, October 2006. As the entire genome sequence of the typical bioplactic-producing microorganism has been discovered, it is expected that the efficient production of bioplastic will be available through strain improvement at a more systematic level. Regarding this paper, Nature Biotechnology requested world-renowned scholar Sang-Yup Lee, LG Chemical Chair-Professor of KAIST Chemical and Biomolecular Engineering Department, an expert analysis on the future of bioplastic production as a result of the deciphering of the genome sequence, and Professor Lee revealed his opinion at ‘News and Views’ in Nature Biotechnology, October 2006, issued on October 10. In the analysis, he insisted, “The deciphering of the genomes of Ralstonia means to pave the way for the improvement of strains at a system level by combining simulation through various omics and imaginary cells and engineering at a genome level. It will be possible to produce plastic with desired properties by altering the components of plastic as desired and produce bioplastic, more efficient and economical than have been reported so far, through the optimization of metabolic flow.” Professor Lee is a world-renowned scholar in the bioplastic field, who has presented about 70 SCI papers in the field. He created a word ‘Plastic Bacteria’ at Trends in Biotechnology in 1996 and published an expert paper regarding E.Coli Plastic at Nature Biotechnology in 1997. He is now performing a research concerning the improvement of bioplastic-producing strains as an example of a research employing a systematic method for the system biological research and development project of the Ministry of Science and Technology. The followings are the contents of Professor Lee’s paper concerning microorganism plastic published at ‘News and Views’ in Nature Biotechnology, October 2006. - Polyhydroxyalkanoate (PHA) is a high molecule that numerous microorganisms accumulate in their own cells as energy storage substance when they are rich in carbonic resources, but poor in the other growth factors. The PHA high molecule is polyester, in which the unit substances (unit chemicals) are ester-bonded, and has been studied worldwide about twenty years before. However, PHA’s worse properties than petrochemical plastic and extremely high production cost have prevented its commercialization. The production cost of PHA was 15 dollars per kg in 1980’s, twenty times higher than the price of polypropylene. Sang-Yup Lee, LG Chemical Chair-Professor of KAIST Chemical & Biomolecular Department’s BK21 Project Group, has performed a research concerning the efficient production of microorganism plastic through the combination of metabolic engineering and fermentation process under the support of the Ministry of Science and Technology, and developed a process that lowers the production cost of PHA to 2-3 dollars per kg. He also has developed PHA-producing bacteria, efficient enough to fill plastic tightly, and named it ‘Plastic Bacteria’. - The unprecedented rise of oil price for the past two years activated the researches on Bio-based energies and chemical production globally. PHA is also regaining attentions although the researches on it have been withered so far due to its poor economical efficiency and properties. The result of the genome deciphering of the typical plastic-producing microorganism ‘Ralstonia eutropha’ published by a German research team in Nature Biotechnology, October 2006 suggests huge meanings. That is, it will provide a blueprint over the metabolic activities of the bacteria and thus enables more systematic strain improvement. - Eyeing on these facts, Nature Biotechnology requested Professor Sang-Yup Lee an expert analysis, and Professor Lee analyzed that there would be a dramatic development of microorganism plastic production through the application of the system biological engineering method, which is now being performed actively by Professor Lee at KAIST. In the analysis, Professor Lee revealed, “As the genome sequence has been found out, it becomes possible to establish metabolic network at a genome level, and since simulation becomes available, numberless trial and errors and experiments can be replaced with imaginary experiments rapidly. In addition, It makes the more efficient development of strains possible by fusion-analyzing the omics result such as various transcripts, proteins, metabolites, etc.” He also expected that it would be possible to produce tailor-made PHA having desired properties through metabolic engineering as well as the efficient production of plastic. Besides, he prospected that his research on the production of optically pure hydroxyl carboxyl acid, Professor Lee’s international patent right, would gain driving forces and technical development would be made rapidly at biological hydrogen production, production, dissolution and application of aromatic compounds, etc. by featuring this strain. - Recently, Metabolic and ADM, U.S. companies, jointly started to produce PHA at a commercialization level, and Brazil having rich natural resources is commercializing PHA, following Bio-ethanol. In addition, Japan and Germany having a bunch of research performance in this field, and Australia having rich biomass are also performing consistent researches on PHA’s commercialization. Professor Lee prospected, “With the finding out of the genome sequence of the typical bioplastic-producing microorganism, competition for commercialization will be fiercer among nations through the development of efficient production systems.” - Professor Lee prospected that as the efficient production of PHA becomes possible, the production of plastic from various renewable ingredients (cellurose, starch, suger, etc.) through microorganism fermentation would be made practically and the white biotechnologies of existing chemicals would gain more power. He also said, “Korea also will have to try to secure the production technologies and industry of Bio-based chemicals through strategic cooperation with resource powerfuls, etc. on the basis of the technical dominancy in some system metabolic engineering fields.” - ‘News and Views’ in Nature Biotechnology is a section that publishes analyses of world-renowned specialists in the corresponding fields over the contents of some papers having great influences among papers published in the issue. KAIST Professor Sang-Yup Lee has published his second expert analysis of ‘Deciphering bioplastic production’ in the volume of October 2006, following the first paper ‘Going into the era of E.Coli plastic’.
Professor Eunjoon Kim's team finds synapse-forming protein
Professor Eunjoon Kim’s team finds synapse-forming protein - discover a new protein ‘NGL’ that promotes the formation of neuronal synapses - can presume the cause of various brain disorders including schizophrenia - will be published at Nature Neuroscience Vol. 9 in September A new protein that promotes the formation of synapses in human brains was discovered by a Korean research team. The team led by Eunjoon Kim, Professor of Department of Biological Sciences and Head of Creative Research Group of Synapse Formation), announced that it had discovered a new fact that NGL protein promotes the formation of neuronal synapses and this fact would be published in Nature Neuroscience Vol. 9 on September 18. Professor Kim’s team discovered that a membrane protein named ‘NGL’ located at post synapse links with other membrane protein named netrin-G in pre synapse, acting as crosslink, and promotes the formation of a new synapse. ‘NGL’ is the second protein found to crosslink synapse, following neuoroligin. With the discovery of this new protein, the principle of synapse formation and the causes of various brain disorders can be presumed. In the human brain, about more than 100 billion neuron cells and about 10,000 synapses compose neural circuit. A synapse is the place where innervation occurs between neuron cells. The formation of synapse induces the formation of neural circuit, and neural circuit is deeply related with various brain disorders as well as normal development of brains or brain functions. “As netrin-G linked with NGL is related with schizonphrenia and neuoroligin and synapse crosslinking protein having a similar function with NGL is deeply related with mental retardation and autism, I think NGL is related with various brain disorders including schizophrenia.” <Explanation of attached photos> ■ Photo1: Experiment for confirming NGL’s ability to form synapse No. 1 Mix ordinary cell (green) revealing NGL at its surface and neuron cell. Axon grows toward NGL (ordinary cell) located in the middle of ten o’clock direction and meets NGL, where NGL induces the formation of pre synapse (red) in the contacting axon. Whether pre synapse has been formed can be told by the fluorescent dying (red) of pre synapse protein named Synapsin. - Figure a-b: formation of synapse by NGL - Figure c-d: transformed NGL losing synapse forming ability cannot form synapse ■ Photo 2: Experiment for confirming NGL’s ability to form synapse No. 2 When beads coated with NGL are scattered on neuron cell, the beads contact with the axon of the neuron cell (the beads are clearly visible at the phase differentiation image in the middle panel). At this time, NGL induces the formation of pre synapse (red) in the axon. Whether pre synapse has been formed can be told by the fluorescent dying (red) of pre synapse protein named SynPhy (panel a) or VGlut1 (panel b).
Gene Protecting Brain Nerves Discovered
THE KOREA TIMES 2005.1.31By Kim Tae-gyu / Staff Reporter South Korean scientists have for the first time discovered genes tasked with protecting brain nerves. Korea Advanced Institute of Science and Technology professor Kim Jae-seob said Sunday the new genes, named pyrexia, shield brain nerves from outside stimuli, including high temperatures. ``The channel gene of pyrexia will open the door to developing new-concept medicines for brain damage in patients of high fever or drug addicts,’’ he said. The channel gene refers to transport proteins, which provide a static passageway for a variety of essential substances to enter into cells. ``Up until now, a lot of channel genes activated by temperatures have been identified. But among them, pyrexia is first that guards brain nerves from external stresses,’’ Kim said. Kim’s team learned pyrexia plays a pivotal role in the body through experiments with genetically engineered flies that did not have any pyrexia. Up to 60 percent of the pyrexia-depleted mutants were paralyzed within three minutes of exposure to a temperature of 40 degrees Celsius. In comparison, just 9 percent of normal flies were paralyzed with the same stimulus, indicating pyrexia is responsible for protecting animals from high-temperature stress. ``Our next goal is to develop pyrexia-embedded drugs, which can be expected to commercially debut in about five years,’’ Kim said. Kim has already applied for international patents for his medical breakthrough, which will be printed in the March edition of Nature Genetics, a science journal. firstname.lastname@example.org
Nerve-protecting gene discovered
Korean scientists for the first time have identified a gene that blocks nerve damage from fevers and the use of narcotics, a state-run research institute said yesterday. The finding may open the way for new medicine that can prevent the loss of brain function which is frequently caused by excessive stimulation of nerves and abnormally high body temperature. "The research is in an early stage. But this approach has the potential to develop genetics-based preventatives against brain-attacking diseases," said Kim Jae-seob, a bioscience professor of the Korea Advanced Institute of Science and Technology, who led the study. The researchers named the gene Pyrexia, which means fever. Kim"s team extracted it from genetically engineered fruit flies using a genome-screening system. In laboratory tests, they found that the gene is activated to 39 degrees Celsius or higher. The researchers enhanced Pyrexia"s functionality in some fruit flies while removing the gene from others to observe their different reactions when exposed to high temperature. "The fruit flies without the gene showed severe nerve disorder and suffered paralysis of brain function, while Pyrexia-enhanced flies maintained their normal brain conditions," the professor said. The researchers got the same result from experiments with human cells, he said. There are a lot of channel proteins, which enable ions to enter and exit the cell, that react to the level of temperature, but Pyrexia is the first of its kind that actually protects the neurons from external stimulus, he said. The finding will appear on the March edition of the London-based science magazine Nature Genetics. THE KOREA HERALD 2005.1.31 (email@example.com) By Kim Tong-hyung
Researchers Find Mechanism of Tumor Suppressor Genes
By Kim Tae-gyu. Staff ReporterTHE Korea Times 02-06-2004 Korean scientists continue to break new ground in fighting cancer as domestic researchers examined the mechanism of a gene which can help detect and treat various sorts of cancer. Korea Advanced Institute of Science and Technology (KAIST) Prof. Lim Dae-sik on Thursday said his team uncovered the mechanism of RASSF1A (Ras Association Domain Family 1 A), or tumor suppressor genes, for the first time in the world. The gene was widely considered to play an important role in reducing the proliferation of cancer cells, but its exact function and processes have remained unknown up to now. It is the second cancer-related breakthrough by Koreans in a week after Korea Institute of Science and Technology (KIST) Prof. Chung Hesson unveiled the oral anti-cancer drug. ``Cancer results from the failed management of cell cycles due to things like radiation. After a two-year intensive study, we found out how RASSF1A governs the cell cycle,"" Lim said. Lim added cancer is caused by abnormal cells, which continue to grow and divide out of control unlike normal cells, which die over time. Cancer cells develop into malignant tumors, eventually inflicting damaging effect on the human body. As a result, a lack of the RASSF1A indicates a high possibility of cancer and injection of it into cells is believed to help cure the deadly disease, according to Lim. Dr. Song Min-sup, who took charge of the research, said the findings will especially pave the way for the detection and treatment of lung cancer. ``The dearth of RASSF1A was reported mostly in the case of lung cancer. The new findings will provide insight into the diagnosis and cure of lung cancer from its early stages,"" Song explained. Lung cancer is a very elusive disease because it doesn"t cause symptoms in its infancy. When symptoms do occur, usually it is too late. ``We expect commercial detection kits or drugs for lung cancer in around five years after pre-clinic experimentation and two-phase clinic trials,"" Song expected. Details of the study is available in the scientific journal Nature Cell Biology in its February edition. firstname.lastname@example.org
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