Empirical Fluctuations in Information Measures

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669

Approximate Distributions of Sample Information for Use in Estimating True Information by Confidence Intervals

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669

Shannon Information Theory and Molecular Biology

The role and the contribution of Shannon Information Theory to the development of Molecular Biology has been the object of stimulating debates during the last thirty years. This seems to be connected with some semantic charms associated with the use of the word \u201cinformation\u201d in the biological context. Furthermore information itself, if viewed in a broader perspective, is far from being completely defined in a fashion that overcomes the technical level at which the classical Information Theory has been conceived. This review aims at building on the acknowledged contribution of Shannon Information Theory to Molecular Biology, so as to discover if it is only a technical tool to analyze DNA and proteinic sequences, or if it can rise, at least in perspective, to a higher role that exerts an influence on the construction of a suitable model for handling the genetic information in Molecular Biology

Effects of Irradiation on the Intestinal Cell Population

The radiation syndrome that kills mice in 3.5 days was found to be mainly due to irradiation of the small intestine. Radiation injuries were defined by anatomical fractionation following irradiation first of the entire body region, then of smaller areas, and finally of surgically exposed individual organs. Irradiation with 1200 rad or more of any region that includes the entire small intestine resulted in death at precisely the same time as irradiation of the whole body. Irradiation of any major fraction of the bowel alone resulted in death under the same circumstances but at a slightly later time, and irradiation of the entire body minus the protected surgically exposed small intestine did not cause a comparable syndrome. The sequence of histological changes in the intestinal epithelium after irradiation is described and cell population kinetics in the irradiated animal is discussed. (C.H.