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....
The relationship between nitrogen (N) availability and the growth of macroalgae in a seasonal upwelling region (Yaquina Head, Oregon, USA) was investigated. Water column nutrient concentrations were relatively high and stable during the winter, decreased in early spring, and were highly variable in the summer and early fall. Periods of...
Originally published in "Proceedings of the Fifth Southern Conference on Forest Tree Improvement," by the School of Forestry, North Carolina State College, Raleigh, N.C., 1959.
This report is the eighth in a series that describe recent oceanographic observations within the California Current system, from Oregon to Baja California. The emphasis here is placed on the observations conducted concurrently by the CalCOFI (California Cooperative Oceanic Fisheries Investigations), IMECOCAL (Investigaciones Mexicanas de la COrriente de CALifornia), and...
An important internal link in the supply chain is between supply managers and their internal customers. These individuals must collaborate to determine purchase specifications, develop sourcing strategies, ensure supplier performance, and maintain effective supplier relationships. Using power and social networking as the theoretical lenses, we develop and test a conceptual...