Skip to main content
Log in

Four-urn catenary model for excretion

  • Published:
Bulletin of Mathematical Biology Aims and scope Submit manuscript

Abstract

A chain-like arrangement of four urns (a catenary system) into which different color balls (white, corresponding to radio atoms, and black, corresponding to stable atoms) are being transferred is used to simulate the transport of atoms down the GI tract of man and animals. Into the first urn (stomach) are placedw o white balls andr black balls while in the 2nd (small intestines) and 3rd (large intestines) urn, onlyr blacks are put in, with no whites. A sample of sizer is transferred from the 1st, 2nd and 3rd urns to the 2nd, 3rd and 4th (infinite universe) urns. From the random variable difference equations the first and second moments for the distribution of the number of radio atoms present in each urn are obtained. The variance of the contents of radioatoms in the excretion urn is

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Literature

  • Bernard, S. R. 1977. “An Urn Model Study of Variability Within a Compartment.”Bull. math. Biol. 39, 463–470.

    Article  MATH  MathSciNet  Google Scholar 

  • Bernard, S. R. and R. L. Hayes. 1970. “Dose to Various Segments of the Gastrointestinal Tract.”Medical Radionuclides: Radiation Dose and Effects. Ed. R. J. Cloutier, C. L. Edwards and W. S. Snyder, AEC Symposium Series 20, pp. 295–314.

  • Bernard, S. R., M. Sobel and V. R. R. Uppuluri 1981. “On a Two-urn Model of Polyatype.”Bull. math. Biol. 43, 33–45.

    Article  MATH  MathSciNet  Google Scholar 

  • Hayes, R. L., J. E. Carlton and W. R. Butler. 1963. “Radiation Dose to the Human Intestinal Tract from Internal Emitter.”Health Phys. 9, 915–920.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

Research sponsored by the Office of Health and Environmental Research, U.S. Department of Energy under contract W-7405-eng-26 with the Union Carbide Corporation.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Sobel, M., Bernard, S.R., Uppuluri, V.R.R. et al. Four-urn catenary model for excretion. Bltn Mathcal Biology 46, 219–227 (1984). https://doi.org/10.1007/BF02460070

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02460070

Keywords

Navigation