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Strains of enteric bacteria and pseudomonads containing plasmid R388::Tnl721 (Tpr, Tcr) or pRO101 (Hgr, Tcr) were starved for over 250 days in sterile well water to evaluate effects of starvation-survival on plasmid expression and maintenance. Viable populations dropped to between approximately 0.1 and 1% of the initial populations. Escherichia coli(pRO101)(More)
Rates of nitrogen fixation and denitrification were measured in Alaskan continental shelf sediments. In some regions, rates of nitrogen fixation and denitrification appeared to be equal; in other areas, rates were significantly different. Potential rates of denitrification were found to be limited primarily by the available nitrate substrate. Major regional(More)
Ectomycorrhizal mats in forest soils have a wide global distribution and have been noted as potentially important elements in forest soil nutrient cycling. To elucidate the relationship between ectomycorrhizal mats and their environment, we undertook field studies and spatial analyses of mat distributions at different spatial scales. We used two(More)
Two methods for determining relative microbial activity in the marine environment were compared. In one method, a single concentration of a labeled substrate was used to calculate rates of substrate utilization; in the other, multiple concentrations of the same substrate (heterotrophic activity method) were used to calculate maximum potential substrate(More)
The acute effects of crude oil on glucose uptake rates by marine microorganisms were studied in 215 water and 162 sediment samples collected from both arctic and subarctic marine waters. The mean percentage reduction of glucose uptake rates ranged from 37 to 58 in the water samples exposed to crude oil and from 14 to 36 in the sediment samples. Substrate(More)
It is generally understood that employees in organizations misuse technology in specific ways--by sending and receiving personal email, frequenting chat rooms, and using the Web for non-work-related reasons. However, little research has focused on what motivates this type of use. The present study extends existing communication technology and organizational(More)
The ectomycorrhizal fungi Gautieria monticola and Hysterangium setchellii both form dense hyphal mats in coniferous forest soils of the Pacific Northwest. We recently observed that all Douglas-fir seedlings found under the canopy of a maturing 60–75 year stand were associated with mats formed by ectomycorrhizal fungi. The significance of these mat(More)
Specialized ectomycorrhizal fungi form dense mats in forest soils that have different enzyme levels, higher respiration rates, more biomass, different soil fauna, and different soil chemistry compared with adjacent soils not obviously colonized by these mats. In this study, mats formed by two genera of fungi collected in three locations were compared with a(More)