Relationships between diatom metrics based on species nutrient traits and agricultural land use.

We assessed how diatom metrics were related to different ranges of agricultural land use. Diatom assemblage composition, nutrients, and landscape characteristics were determined at 232 sites in eight agriculturally dominated study areas of the continental United States. Two regional groups based on differences in diatom relations to human disturbance were determined.

The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan.

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. This study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p < 0.

Effects of excess copper on growth of wild rice (Zizania palustris) seedlings tested in reconstituted and natural waters.

Dissolved copper was toxic to wild rice (Zizania palustris) seedlings when exposed in water from the seed collection site of Swamp Creek, Crandon, Wisconsin, USA, and in laboratory-prepared artificial or reconstituted water. Seeds for the study were harvested, then held through a portion of dormancy, in Swamp Creek. After 60 days they were shipped to a laboratory, chilled, and tested with copper after germination.

Control of photon beam dose profiles by localized transverse magnetic fields.

Unlike electron beams, scant attention has been paid in the literature to possible magnetic field effects on therapeutic photon beams. Generally, dose profiles are considered to be fully determined by beam shape, photon spectrum and the substances in the beam path. Here we show that small superconducting magnets can exercise potentially useful control over photon dose profiles.

Metabolism of intranasally applied cocaine.

Surprisingly little is known about the metabolism and toxicity of cocaine in man. In this study serum obtained following nasal surgery was assayed for benzoylecgonine (the major metabolite of cocaine) by radioimmunoassay. It was found that cocaine was rapidly hydrolyzed in the serum.

FOUR HUNDRED AND FIFTY CONSECUTIVE OPEN HEART OPERATIONS.

Four hundred and fifty consecutive open heart operations on 437 patients, using cardiopulmonary by-pass, were done at the Stanford Medical Center from January 8, 1960, to July 15, 1964. The in-hospital mortality was 6.4 per cent.