Soil phosphorus (P) availability was compared with Mehlich-1 soil testing and P fractionation at a research farm (RF) and 32 private farms (PFs) in north Florida. The environmental risks caused by P release were evaluated using the P saturation ratio (PSR). Soil Mehlich-1 P at the RF and the PFs was 41.9 4.1 and 278 13 mg/kg, respectively. The dominant inorganic P fraction for all farms was NaO...

Isocratic high-performance liquid chromatography methods are described for separating the major classes of phospholipids and for isolating the individual molecular species of phospholipids. Fractionation of a total lipid extract of rat liver on a silica column resulted in quantitative recoveries of all major phospholipids with preservation of their fatty acid composition. Rat liver phosphatidyl...

A method is reported for the isolation of a highly purified fraction of urinary bladder membranes containing hexagonal plaques. The method uses zonal centrifugation as the final step of fractionation. The purified fraction was characterized by its electron microscopic morphology, by its enzymatic profile, by quantitative and qualitative analysis of lipids and by the protein pattern obtained by ...

Phosphorus retention in sediments has been estimated for three basins in Lake Simcoe, a mesotrophic lake in Ontario, Canada. Total phosphorous (TP) fractionation was used to examine the concentration of phosphorus (P) binding forms in the sediments of Cook's Bay, Kempenfelt Bay, and the Main Basin. The extended sequential extractions allowed us to differentiate between organic-, inorganic-, car...

Historically it has been shown repeatedly that single high doses of radiation do not allow a therapeutic differential between tumor and critical normal tissues but dose fractionation does. The purpose of conventional dose fractionation is to increase dose to the tumor while preserving normal tissue function. Tumors are generally irradiated with 2Gy dose per fraction delivered daily to a more or...