The relative contribution of various inorganic and organic forms of nitrogen to the nitrogen requirements of picoplankton was examined with 15N tracers. Size fractionation was used to measure uptake by <1-μM size microorganisms, and inhibitors of protein synthesis were used to separate procaryotic from eucaryotic nitrogen uptake, Picoplankton utilized mainly...
The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even greater in...
Diel periodicity in NH4+ uptake and regeneration in the nutrient-rich environment of the oceanic subarctic Pacific was examined. Surface water was incubated in large shipboard microcosms that allowed repeated sampling of the planktonic community for NH4+ cycling rates, bacterial production rates, and population densities of the dominant autotrophs and heterotrophs....
At a time when environmental conditions are rapidly changing, understanding how thermal extremes impact wildlife is imperative to fully understanding the consequences of climate change in natural ecosystems. While many organisms are currently impacted by rapidly warming and more erratic environmental conditions, identifying and investigating model species whose life histories...
The lens dose equivalent (LDE) is a regulatory limit set to protect radiation workers. Current methods for estimating the LDE are specific to beam sources in a vacuum and require interpolating data from tables. A new set of deterministic equations for photon and electron point sources has been developed. These...
The nursing profession has long sought more diversity in registered nurses (RNs) to reflect the populations served. One way to enhance RN diversity is through diversity in community college (CC) associate degree in nursing (ADN) programs.
Since ADN programs lead to professional employment with middle-class wages, they form an important...
The use of radioactive isotopes as tracers in biological systems
has become widespread since the close of World War II. Proper
use of radiotracers requires a fundamental understanding of the physical
nature of radioactivity, the characteristics of ionizing radiation,
and the various methods available for measuring radioactivity.
More importantly, the...
Descriptions and distributions are given of 28 species of
Liparidae occurring or possibly occurring below 200 m between San
Francisco and northern Vancouver Island, with keys for their identifications.
Nine genera are included: Careproctus, Elassodiscus,
Lipariscus, Nectoliparis, Rhinoliparis, Acantholiparis, Paraliparis,
and two new genera are described, Odontoliparis and Osteodiscus.
Eight...
Field, growth chamber, and greenhouse studies were carried
out to evaluate factors that cause low seed set in Dactylis Glomerata
L. The variety, 'Latar', and the parental clones of the variety,
'Pennlate', were studied in detail.
Floral anatomy investigations indicated that 98 percent of
Dactylis flowers opened at Corvallis in...