Prostate-specific antigen (PSA) is a recently described marker for prostate carcinoma (1). In patients with prostatic cancer the concentration of PSA in serum can be as much as 10 mg/L, whereas concentrations in healthy men are <2.8 zg/L (2). Hybritech’s immunoradiometric assay for PSA has been in routine use in our laboratory for 15 months. Its reproducibility is generally good, but two sample...

A simple classification scheme that uses only the presence or absence of a protein domain architecture has been used to determine the phylogeny of 174 complete genomes. The method correctly divides the 174 taxa into Archaea, Bacteria, and Eukarya and satisfactorily sorts most of the major groups within these superkingdoms. The most challenging problem involved 119 Bacteria, many of which have r...

9 Introduction to Number Theory 168 9.1 Subgroups of the Integers . . . . . . . . . . . . . . . . . . . . 168 9.2 Greatest Common Divisors . . . . . . . . . . . . . . . . . . . . 168 9.3 The Euclidean Algorithm . . . . . . . . . . . . . . . . . . . . . 169 9.4 Prime Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 172 9.5 The Fundamental Theorem of Arithmetic . . . . . . . . . . . . ...

Within 5 to 10 min at 37 C, bacteria infected by bacteriophage OX174 acquire the ability to exclude superinfecting OX particles from reproducing themselves. The superinfecting phage are blocked at a stage prior to synthesis of the parental replicative form molecule; the superinfecting deoxyribonucleic acid remains as intact (infective) single strands. Establishment of superinfection exclusion a...

© Informal Logic Vol. 26, No. 2 (2006): pp. 149-174.