Felix Breitenecker

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Cellular Automata are being applied as a method for mathematical modelling and simulation in a variety of scientific areas. Usually a cellular automaton constitutes a microscopic description or abstraction of a natural system. The tools used for a mathematical derivation and validation of the cellular automaton modelling approach are however often optimised(More)
The theme of this master thesis was motivated by a benchmark of the Federation of European Simulation Societies, EUROSIM. The Benchmark deals with the problem of groundwater pollution. A two-dimensional domain filled with water may be considered. In the middle of this area a pollution source is located. This source emits solid constantly or at certain(More)
To establish a qualitative and quantitative model of blood glucose response to stress hormone exposure, healthy subjects (HS) on and off somatostatin (250 micrograms/h) as well as insulin dependent diabetic patients were infused with either epinephrine (E), glucagon (G), cortisol (F), growth hormone (GH) or with a cocktail of these hormones raising plasma(More)
To elucidate the efficacy of continuous vs. intermittent exposure to epinephrine, phenylephrine, and insulin, hepatic glucose production was monitored in isolated perfused rat livers (means +/- SE, n = 6 each). To this end livers of fed rats were perfused with 5 mM glucose Krebs-Ringer buffer in a nonrecirculating system. Using this model it was shown that(More)
To elucidate in vitro the transience of glucagon-induced hepatic glucose release, the effects of glucagon on hepatic glucose production and cAMP release were evaluated in the isolated rat liver preparation perfused by a nonrecirculating system. Glucagon was added to the infusate in stepwise increasing concentrations at 0, 60, and 100 min to give final(More)
PURPOSE Prostate-specific antigen (PSA) doubling-time (PSA-DT) is an important indicator of progression and survival in men with prostate cancer. Three major limitations regarding PSA-DT determination may lead to inconsistent results: the variety of mathematical methods currently applied, the non-standardized handling of input variables and the potential(More)
With the progress in modeling dynamic systems new extensions in model coupling are needed. The models in classical engineering are described by differential equations. Depending on the general condition of the system the description of the model and thereby the state space is altered. This change of system behavior can be implemented in different ways. In(More)
BACKGROUND Hormone receptor expression can be quantified by computerized image analysis in immunohistochemically stained specimens. When comparing semiquantitative scoring with computerized image analysis a review of the literature shows contradictory findings concerning the correlation of these two methods. Recent technical approaches have been developed(More)