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PubMed2000

Random walk with an exponentially varying step

A random walk with exponentially varying step, modeling damped or amplified diffusion, is studied. Each step is equal to the previous one multiplied by a step factor s (0 1/s relating different processes. For s<1/2 and s>2, the process is retrodictive (i.e., every final position can be reached by a unique path) and the set of all possible final points after infinite steps is fractal. For step factors in the interval [1/2,2], some cases result in smooth density distributions, other cases present overlapping self-similarity and there are values of the step factor for which the distribution is singular without a density function.

Journal Article↗

PubMed1995

[Massive pleural effusion in liver cirrhosis without ascites].

We present two patients with masive pleural effusion, asociated to cirrhosis. There was no clinical evidence of ascites, and in the first case it didn't even show up in the CT scanning. Al other posible causes were discarded and the therapeutic response was analysed. We evaluated the pathophysiologic mechanisms of the syndrome and we suggest the pneumoperitoneum as a diagnostic procedure which is easy to apply and carries low costs.

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