Photophysiology: Current Topics in Photobiology and Photochemistry, Volume VI is a collection of papers that discusses photobiological phenomena found on cells of organisms. The papers in this collection deal with specialized areas of photobiology. One paper describes the instruments used in measuring the course of chlorophyll fluorescence in vivo that occurs when a chlorophyll molecule, stimulated by a light source, returns to its ground state from a previous first singlet state, resulting in a light emission lasting for a few nanoseconds. Another paper discusses the mechanism of light-induced carotenoid synthesis in nonphotosynthetic plants, including temperature-independent photochemical reactions, which results in the organism's producing carotenoids on subsequent incubations in darkness. One paper also explains photosensitization observed in mutant cells resulting from exposure to specific wavelength of light in the presence of a natural sensitizer. This paper points out that there are four main groups of photosensitizers, namely, the hypericins, chlorophylls, porphyrins, and psoralens. This book can prove valuable for cell biologists, micro-biologists, students, and researchers involved in the fields of photobiology and photochemistry.

First multi-year cumulation covers six years: 1965-70.

1. Biological, Photochemical, and Spectroscopic Applications of Lasers.- 2. Photochemistry of the Nucleic Acids.- 3. Ultraviolet Radiation Effects on the Human Eye.- 4. Lethal and Mutagenic Effects of Near-Ultraviolet Radiation.- 5. DNA Repair Enzymes in Mammalian Cells.

A keyword listing of serial titles currently received by the National Library of Medicine.

A symposium on biophysical ecology was held at The University of Michigan Biological Station on Douglas Lake August 20-24, 1973. Biophysical ecology is an approach to ecology which uses fundamental principles of physics and chemistry along with mathematics as a tool to understand the interactions between organisms and their environment. It is fundamentally a mechanistic approach to ecology, and as such, it is amenable to theoretical modeling. A theoretical model applied to an organism and its interactions with its environ ment should include all the significant environmental factors, organism properties, and the mechanisms that connect these things together in an appropriate organism response. The purpose of a theoretical model is to use it to explain observed facts and to make predictions beyond the realm of observation which can be verified or denied by further observation. If the predictions are confirmed, the model must be reasonably complete except for second or third-order refinements. If the pre dictions are denied by further observation, one must go back to the basic ideas that entered the model and decide what has been overlooked or even what has been included that perhaps should not have been. Theoretical modeling must always have recourse to experiment in the laboratory and observation in the field. For plants, a theoretical model might be formulated to explain the manner and magnitude by which various environmental factors affect leaf temperature.

Issues for 1977-1979 include also Special List journals being indexed in cooperation with other institutions. Citations from these journals appear in other MEDLARS bibliographies and in MEDLING, but not in Index medicus.