Technical Monograph PRG-16 May 1981 Oxford University Computing Laboratory. Programming Research Group. 45 Banbury Road. Oxford. OX2 6PE A mathematical model for communicating sequential processes Is given. and a number of Its Interesting and useful properties are stated. The possibilities of non-determinism are fully taken into account.

Beneficiaries of the Old-Age, Survivors, and Disability Insurance (OASDI) program received an 11.2-percent cost-of-living increase in benefits effective June 1981. This increase, the seventh automatic increase since 1975, was reflected in btiefit checks issued early in July. Automatic benefit increases are tied by statute to rises in the Consumer Price Index (CPI). They are initiated whenever t...

Max Ludwig Henning Delbrück applied his knowledge of theoretical physics to biological systems such as bacterial viruses called bacteriophages, or phages, and gene replication during the twentieth century in Germany and the US. Delbrück demonstrated that bacteria undergo random genetic mutations to resist phage infections. Those findings linked bacterial genetics to the genetics of higher organ...

In 1981, Cuba reported the fi rst hemorrhagic dengue epidemic in the Americas, with 344,203 cases, including 10,312 severe and very severe cases, resulting in 158 deaths. In the 30 years following the epidemic, surveillance, control and research have kept Cuba dengue free; although isolated, interrupted epidemics and transmissions have been reported. In this article, we summarize issues of inte...