Functional model of the pancreatic islet of Langerhans with the HOT and COLD optimization methods

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This research is concerned with risk aversive structure and its function of the pancreatic islet of Langerhans constructed with the highly optimized tolerance (HOT) and the constrained optimization with limited deviations (COLD) models.At the first stage of the project, I developed software to generate HOT structures. The validity of the software was verified by applying the software to a toy problem of bio-terrorism in which the structure of a hypothetical bio-sensor network, as a defensive resource against bio-terrorism utilizing pathogenic virus, is optimized with the HOT modelAt the second stage, I utilized a cluster of pancreatic β-cells subject to Sherman's model to approximate an actual pancreatic islet. The performance of the cell-cluster was examined in terms of the fidelity in the permutation entropy of interspike time intervals of the membrane potential to that of actual cells in the islet. As a preliminary numerical experiment, the influence of statistical distribution of the cell parameters on complexity of the electrical activity was examined. Variances in the cell parameters lying between 10 and 15% about mean were found to be able to reproduce the permutation entropy of the actual dynamical behavior.At the final stage, under the assumption that the pancreatic α-cells and δ-cells form scale-free structure in the pancreatic islet, I got started with developing software to generate cell-deficiencies in a β-cell cluster to simulate the structure of an actual pancreatic islet where α-cells, β-cells and δ-cells are supposed to reside in the HOT state. This software is under development, which will reveal importance of the HOT state of the cell-arrangement.