Articles by David S. Duncan in JoVE
A Lipid Extraction and Analysis Method for Characterizing Soil Microbes in Experiments with Many Samples Lawrence G. Oates1, Harry W. Read2, Jessica L. M. Gutknecht3, David S. Duncan1, Teri B. Balser4, Randall D. Jackson1 1Department of Agronomy and Great Lakes Bioenergy Research Center, University of Wisconsin - Madison, 2Department of Soil Science, University of Wisconsin - Madison, 3Department of Soil, Water, and Climate, University of Minnesota, 4Faculty of Science and Engineering, Curtin University The article describes a method that increases throughput while balancing effort and accuracy for extraction of lipids from the cell membranes of microorganisms for use in characterizing both total lipids and the relative abundance of indicator lipids to determine soil microbial community structure in studies with many samples.
Other articles by David S. Duncan on PubMed
The Accuracy of Multidetector Computed Tomography in the Diagnosis of Non-occlusive Mesenteric Ischaemia in Patients After Cardiovascular Surgery Critical Care and Resuscitation : Journal of the Australasian Academy of Critical Care Medicine. Jun, 2014 | Pubmed ID: 24888278 To determine the accuracy of multidetector computed tomography (MDCT) in the diagnosis of nonocclusive mesenteric ischaemia (NOMI) among patients after cardiovascular surgery.
Bouncing Back: Plant-associated Soil Microbes Respond Rapidly to Prairie Establishment PloS One. 2014 | Pubmed ID: 25551613 It is well established that soil microbial communities change in response to altered land use and land cover, but less is known about the timing of these changes. Understanding temporal patterns in recovering microbial communities is an important part of improving how we assess and manage reconstructed ecosystems. We assessed patterns of community-level microbial diversity and abundance in corn and prairie plots 2 to 4 years after establishment in agricultural fields, using phospholipid fatty acid biomarkers. Principal components analysis of the lipid biomarkers revealed differing composition between corn and prairie soil microbial communities. Despite no changes to the biomass of Gram-positive bacteria and actinomycetes, total biomass, arbuscular mycorrhizal fungi biomass, and Gram-negative bacteria biomass were significantly higher in restored prairie plots, approaching levels found in long-established prairies. These results indicate that plant-associated soil microbes in agricultural soils can shift in less than 2 years after establishment of perennial grasslands.
Nitrogen Fertilization Effects on Productivity and Nitrogen Loss in Three Grass-Based Perennial Bioenergy Cropping Systems PloS One. 2016 | Pubmed ID: 26991790 Nitrogen (N) fertilization can greatly improve plant productivity but needs to be carefully managed to avoid harmful environmental impacts. Nutrient management guidelines aimed at reducing harmful forms of N loss such as nitrous oxide (N2O) emissions and nitrate (NO3(-)) leaching have been tailored for many cropping systems. The developing bioenergy industry is likely to make use of novel cropping systems, such as polycultures of perennial species, for which we have limited nutrient management experience. We studied how a switchgrass (Panicum virgatum) monoculture, a 5-species native grass mixture and an 18-species restored prairie responded to annual fertilizer applications of 56 kg N ha(-1) in a field-scale agronomic trial in south-central Wisconsin over a 2-year period. We observed greater fertilizer-induced N2O emissions and sub-rooting zone NO3(-) concentrations in the switchgrass monoculture than in either polyculture. Fertilization increased aboveground net primary productivity in the polycultures, but not in the switchgrass monoculture. Switchgrass was generally more productive, while the two polycultures did not differ from each other in productivity or N loss. Our results highlight differences between polycultures and a switchgrass monoculture in responding to N fertilization.