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Biomedical subjects

E M Rosell

Publications and source records attributed to E M Rosell.

4 recordsLinked to original sources
PubMed1989

Angular homeostasis: IV. Polygonal orbits.

Some properties are discussed of regular polygons that may result from angular homeostatic processes in stable orbit. To characterize these "homeostatic polygons" we need to discuss the winding number, the sidedness (integer, fractional and irrational), multiplicity, envelopes, and density. A regular (i.e., equilateral, equiangular) polygon may be closed in one revolution about its unique center, in multiple revolutions, or not at all. A homeostatic polygon can be generated only if all vertices are included in a single polygon, which occurs if and only if the number of vertices and the number of revolutions required to complete the polygon are relatively prime. For the homeostatic polygon to have a finite number of sides (without repeating itself) the angle subtended by any two successive vertices at the center must be a rational multiple of 2 pi. Biological implications of these properties are illustrated.

Cell Communication↗
PubMed1982

Theory of genetic counseling for rare recessive traits with consanguinity.

The theory of assessing genetic risk for rare autosomal recessive traits in the face of extensive consanguinity is explored. A general lemma is proved that justifies the partition of posterior probability and recursive incorporation of it, as a means of reducing the logic of analysis to steps of manageable complexity: the conditions are that either the components should be independent or that each component, as it is added, is conditioned on the occurrence of all earlier components. An example is given of a pedigree in which the tracing of a gene by the method of expected proportions is misleading, and another that points up the importance of the posterior information. Four classes of patterns are identified and appropriate methods devised for handling them: the single consanguineous loop, multiple mutually-external loops, nested loops, and multiple closures. The latter problem may be treated in general by the use of truncated generating functions, with or without the use of matrix methods.

Bayes Theorem↗