Robert A. Burns

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Acclimation to one environmental factor may constrain acclimation to another. Synechococcus elongatus (sp. PCC7942), growing under continuous light in high inorganic carbon (Ci; approximately 4 mm) and low-Ci (approximately 0.02 mm) media, achieve similar photosynthetic and growth rates under continuous low or high light. During acclimation from low to high(More)
BACKGROUND Little is known about the critical period during which the dietary supply of long-chain polyunsaturated fatty acids (LCPUFAs) may influence the maturation of visual cortical function in term infants. AIM To define the relationship between duration of dietary LCPUFA supply and visual acuity at 52 weeks of age. STUDY DESIGN Data from 243(More)
Our initial studies have shown that the cellular slime mold Dictyostelium discoideum is a particularly suitable organism for the study of lysosomal enzyme secretion. During appropriate stages in the life cycle, secretion is prominent for a number of lysosomal enzymes. The methods described here have been developed to investigate various aspects of the(More)
A simple kinetic model for the enzymatic activity of surface-active proteins against mixed micelles has been developed. This model uses the Langmuir adsorption isotherm, the classic equation for the binding of gas molecules to metal surfaces, to characterize enzyme adsorption to micelles. The number of available enzyme binding sites is equated with the(More)
A number of typical lysosomal enzymes are very efficiently secreted from amoebae of the cellular slime mold, Dictyostelium discoideum, during growth and early development. Using conditions which employ axenically grown amoebae in suspension in a simple starvation buffer, the lysosomal enzymes are secreted at rates that are at least as rapid as during normal(More)
The four earliest developmentally controlled enzymes in the cellular slime mold, Dictyostelium discoideum, accumulate during axenic growth in rich media. We have shown that at low cell titers the specific activities of N-acetylglucosaminidase, alpha-mannosidase, leucine aminopeptidase, and alanine transaminase are each at very low or vegetative levels(More)
Synechococcus elongatus strain PCC7942 cells were grown in high or low environmental concentrations of inorganic C (high-Ci, low-Ci) and subjected to a light shift from 50 µmol m−2 s−1 to 500 µmol m−2 s−1. We quantified photosynthetic reductant (O2 evolution) and molar cellular contents of phycobilisomes, PSII, PSI, and ribulose-1,5-bisphosphate carboxylase(More)