• The Microorganisms and Industry
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• v.12 no.2
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• pp.14-18
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• 1986

Barcterial chemotaxis is a transient response of an organism in a situation where environmental homogeneity has been disturbed by certain chemical compounds. The phenomenon has been described in motile bacterial species including enteric bacteria, Gram-positives(14), Spirochaetes (6) and even Archaebacteria (8). However, most comprehensive studies have been done with Escherichia coli and Salmonella typhimurium. Two analogies to higher eucaryotic sensory phenomena are provided by the study of bacterial chemotaxis. First, bacterial chemotaxis is similar to the stimulus-response of neuronal, immune and sperm cells. Second, studies of individual components involved in the bacterial sensory pathway can contribute to the understanding of the function of receptors, controling signals and molecular comparators in transmembrane signalling system. The bacterial sensory transducer, a chemoreceptor in a broad sense, is a unique entity for studying sensory function in which sensory reception, signalling and adaptation are integrated (7,18).

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.711-712
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• 2002

A numerical study of a hemodynamical model for the tumor angiogenesis is carried out. The tumor angiogenesis process is comprised of a sequence of events; secretion of tumor angiogenesis factor(TAF) from the solid tumor, degradation of the basement membrane of nearby blood vessels, migration and proliferation of the endothelial cells. The model takes into account the effect of TAF concentration and endothelial cell density, and their conservation equations are represented as a set of one-dimensional initial boundary value problems. These equations are discretized by using a finite difference method in which the second order schemes both in time and in space are used. The effects of the parameters contained in the model are Investigated extensively through the numerical simulation of the discretized model. The result for the typical case compares very well with the known result.