Stochastic properties of an autocatalytic reaction system constrained to have a carrying capacity are studied by considering the effects of whitehyphen;noise fluctuations on various rate parameters. The transient behaviors and the subsequent steady state (SS) possibilities in these noisy systems are analyzed through the Stratonovich calculi together with the moment expansion approximation scheme. The results can thus be compared readily with those of the internal fluctuations. It is found that, among various noises, the noise in the carrying capacity is most fatal to the reaction processes while the additive noise is less significant. It is interesting to find that the multiplicative noise due to the fluctuating net growth rate may induce a slowing down phenomena when the noise intensity approaches a critical value. The stochastic SS structures are found to be similar to those found previously for the internal case. Though the stable SS are possible over a wide range of noise intensities, the transient behaviors demonstrate that a fluctuation catastrophe may happen long before the expected SS is established.
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