A sensitive assay for the analysis of contaminating segments
in pseudorecombinants constructed from a seed-transmissible (CVM-Pg)
and a non-seed-transmissible (CMV-Le) strain of cucumber mosaic
virus was developed using partial RNase T₁ digestion. Isolated
genomic RNA segments produced unique digestion patterns when 3'-
end labeled, treated with RNase T₁, and subjected...
The uptake of methylammonium (MA) by Chesapeake Bay phytoplankton was measured in short term experiments by using the 14C radioisotope. This uptake was inversely related to ambient NH4+ concentrations, and the specificity for uptake of both substrates was demonstrated by competitive inhibition. At stations with low ambient NH4+, MA uptake...
The virulence of selected isolants of infectious hematopoietic
necrosis virus (IHNV) were differentiated and correlated with
electrophoretic mobilities of virion structural proteins by sodium
dodecylsulfate polyacrylamide gel electrophoresis. A type 1
electropherotype of IHNV was more virulent for kokanee salmon
(Oncorhynchus nerka) and a type 2 strain more virulent for...
Sunflower (Helianthus annuus L., cv. NK894) seedlings, grown hydroponically, were exposed to ozone concentrations of 0.0, 0.1, 0.2, and 0.3 ppm at 60% RH, or 0.0
and 0.3 ppm at 30% and 90% RH, for 6 h/d, for four consecutive days, at ages 15 to 18 days from seeding. Plant...
Epiphytic, planktonic and benthic diatom assemblages were investigated in Netarts Bay, Oregon. Samples were collected for a
one-year period from February 1980 to March 1981. A planktonic flora was observed only during periods of offshore enrichment when marine neritic species were abundant and were transported into the bay by tidal...
In the cockroach Leucophaea maderae, a centre in the brain controls the female's acceptance of courting males. This centre is affected by starvation. A brief exposure to food can induce mating but is inadequate for oocyte development. In fed L. maderae there appears to be a synergistic action of nutrition...