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Full-Text Articles in Life Sciences
Arabian Sea Response To Monsoon Variations, Raghu Murtugudde, Richard Seager, Prasad Thoppil
Arabian Sea Response To Monsoon Variations, Raghu Murtugudde, Richard Seager, Prasad Thoppil
Faculty Publications
This study aims to quantify the impact of strong monsoons on the mixed layer heat budget in the Arabian Sea by contrasting forced ocean general circulation model simulations with composite strong and weak monsoon winds. Strong (weak) monsoons are defined as years with zonal component of the Somali Jet being greater (smaller) by more than a standard deviation of the long-term mean of the National Centers for Environmental Prediction reanalysis winds. Coastal upwelling is shown to be demonstrably stronger for strong monsoons leading to significant surface cooling, shallower thermoclines, and deeper mixed layers. A coupled ecosystem model shows that surface …
Evalution Of The Efficacy Of The Photosystem Ii Inhibitor Dcmu In Periphyton And Its Effects On Nontarget Microorganisms And Extracellular Enzymatic Reactions, Steven N. Francoeur, Audrey C. Johnson, Kevin A. Kuehn, Robert K. Neely
Evalution Of The Efficacy Of The Photosystem Ii Inhibitor Dcmu In Periphyton And Its Effects On Nontarget Microorganisms And Extracellular Enzymatic Reactions, Steven N. Francoeur, Audrey C. Johnson, Kevin A. Kuehn, Robert K. Neely
Faculty Publications
We examined the efficacy of the photosystem II inhibitor 3-(3,4-diclorophenyl)-1,1-dimethyl urea (DCMU) for inhibition of algal photosynthesis in periphyton associated with submerged decomposing litter of Typha angustifolia. We also investigated the possible nontarget effects of DCMU exposure on heterotrophic microorganisms (i.e., bacteria and fungi) and extracellular enzyme activity associated with decaying litter. Standing-dead Typha leaf litter was submerged for 34 and 73 d, returned to the laboratory, and used for controlled laboratory experiments that examined the effect of DCMU on algal ([14C]bicarbonate, pulse-amplitude modulated fluorometry), bacterial ([3H]leucine), and fungal ([14C]acetate) production. Simultaneous assays …
A Statistical Appraisal Of Disproportional Versus Proportional Microbial Source Tracking Libraries, Brian J. Robinson, Kerry J. Ritter, Rudolph D. Ellender
A Statistical Appraisal Of Disproportional Versus Proportional Microbial Source Tracking Libraries, Brian J. Robinson, Kerry J. Ritter, Rudolph D. Ellender
Faculty Publications
Library-based microbial source tracking (MST) can assist in reducing or eliminating fecal pollution in waters by predicting sources of fecal-associated bacteria. Library-based MST relies on an assembly of genetic or phenotypic "fingerprints" from pollution-indicative bacteria cultivated from known sources to compare with and identify fingerprints of unknown origin. The success of the library-based approach depends on how well each source candidate is represented in the library and which statistical algorithm or matching criterion is used to match unknowns. Because known source libraries are often built based on convenience or cost, some library sources may contain more representation than others. Depending …
Algal Regulation Of Extracellular Enzyme Activity In Stream Microbial Communities Associated With Inert Substrata And Detritus, Steven T. Rier, Kevin A. Kuehn, Steven N. Francoeur
Algal Regulation Of Extracellular Enzyme Activity In Stream Microbial Communities Associated With Inert Substrata And Detritus, Steven T. Rier, Kevin A. Kuehn, Steven N. Francoeur
Faculty Publications
We tested the hypothesis that algae influence the activities of extracellular enzymes involved in mineralization processes within microbial assemblages in streams. We tested the prediction that the factors that influence algal biomass and photosynthesis (i.e., diel fluctuations in photosynthetically active radiation [PAR], long-term variations in light regime, and community development stage) would have a corresponding effect on extracellular enzyme activities. We also tested the prediction that algae would influence enzyme activities on inorganic substrata and in detrital communities where they ultimately would influence plant litter decomposition rates. We allowed microbial communities to develop on inert substrata (glass-fiber filters) or on …