Phagotrophic protists are major consumers of microbial biomass in aquatic ecosystems. However, biochemical mechanisms underlying prey recognition and phagocytosis by protists are not well understood. We investigated the potential roles of cell signaling mechanisms in chemosensory response to prey, and in capture of prey cells, by a marine ciliate (Uronema...
Marine bacterioplankton play an important role in global elemental cycles because they return carbon dioxide and nutrients to the biosphere as they reduce organic matter. Furthermore, marine bacterioplankton are not uniformly active, and subpopulations of the in situ community may be more or less active at any given time. Defining...
The objectives of this study were to: (1) determine if individual
differences in the learner characteristics of field dependence, state
and trait anxiety, age, sex, and prior computer experience were related
to performance in operating a computer system; (2) to determine if
differences in performance would occur as a result...
The biological transformation of dinitrogen gas (N2) into combined forms(termed N2 fixation) by certain genera of oceanic cyanobacteria represents the largest incoming flux of nitrogen to the global ocean. As such, biological nitrogen fixation
plays a significant role in the regulation of oceanic productivity and the export of
carbon and...
Workers with dimethyl sulfoxide (DMSO) in the
United States and England have reported in the literature
that the chemical affects the weight gaining ability of
experimental animals. Narula, University of Oregon
Medical School, Portland, found that 50 parts per million
DMSO increased the size and numbers of tissue culture
cells....
Effects of light intensity, exposure to desiccation, reduced
salinity, and thermal elevation on the functional and structural characteristics
of marine benthic diatom communities were investigated
in a laboratory model ecosystem and a respirometer chamber.
Measurements of biomass (dry weight and ash-free dry weight)
and chlorophyll a were made for each...
Animal dietary preferences have been studied by feeding-site
examinations, animal observation, and stomach and esophageal collections.
Analysis of fecal material for undigested plant cuticle is
another means for obtaining the same information.
This study was conducted to: (1) prepare a microscope slide
series depicting the surface features of leaves and...
To determine which isolates will most rapidly replace
Phellinus weirii in stumps and roots, Trichoderma spp. were
isolated from P. weirii-infested stumps and roots, identified, and
examined for growth rates and lethal effects on P. weirii in vitro.
Phellinus weirii-infested Douglas-fir stumps and stump roots
were sampled for microorganisms by...