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Full-Text Articles in Life Sciences

Arabian Sea Response To Monsoon Variations, Raghu Murtugudde, Richard Seager, Prasad Thoppil Dec 2007

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 Dec 2007

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 …


Development Of New Simple Sequence Repeat Markers For Pearl Millet, O. P. Yadav, S. E. Mitchell, A. Zamora, Theresa M. Fulton, Stephen Kresovich Dec 2007

Development Of New Simple Sequence Repeat Markers For Pearl Millet, O. P. Yadav, S. E. Mitchell, A. Zamora, Theresa M. Fulton, Stephen Kresovich

Faculty Publications

No abstract provided.


Species Invasion Shifts The Importance Of Predator Dependence, Blaine D. Griffen, David G. Delaney Dec 2007

Species Invasion Shifts The Importance Of Predator Dependence, Blaine D. Griffen, David G. Delaney

Faculty Publications

The strength of interference between foraging individuals can influence per capita consumption rates, with important consequences for predator and prey populations and system stability. Here we demonstrate how the replacement of a previously established invader, the predatory crab Carcinus maenas, by the recently invading predatory crab Hemigrapsus sanguineus shifts predation from a species that experiences strong predator interference (strong predator dependence) to one that experiences weak predator interference (weak predator dependence). We demonstrate using field experiments that differences in the strength of predator dependence persist for these species both when they forage on a single focal prey species only (the …


A Statistical Appraisal Of Disproportional Versus Proportional Microbial Source Tracking Libraries, Brian J. Robinson, Kerry J. Ritter, Rudolph D. Ellender Dec 2007

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 …


Extracellular Stimuli Specifically Regulate Localized Levels Of Individual Neuronal Mrnas, Dianna E. Willis, Erna A. Van Niekerk, Yukio Sasaki, Mariano Mesngon, Tanuja T. Merianda, Gervan G. Williams, Marvin Kendall, Deanna S. Smith, Gary J. Bassell, Jeffery L. Twiss Sep 2007

Extracellular Stimuli Specifically Regulate Localized Levels Of Individual Neuronal Mrnas, Dianna E. Willis, Erna A. Van Niekerk, Yukio Sasaki, Mariano Mesngon, Tanuja T. Merianda, Gervan G. Williams, Marvin Kendall, Deanna S. Smith, Gary J. Bassell, Jeffery L. Twiss

Faculty Publications

Subcellular regulation of protein synthesis requires the correct localization of messenger RNAs (mRNAs) within the cell. In this study, we investigate whether the axonal localization of neuronal mRNAs is regulated by extracellular stimuli. By profiling axonal levels of 50 mRNAs detected in regenerating adult sensory axons, we show that neurotrophins can increase and decrease levels of axonal mRNAs. Neurotrophins (nerve growth factor, brainderived neurotrophic factor, and neurotrophin-3) regulate axonal mRNA levels and use distinct downstream signals to localize individual mRNAs. However, myelin-associated glycoprotein and semaphorin 3A regulate axonal levels of different mRNAs and elicit the opposite effect on axonal mRNA …


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 Sep 2007

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 …


Distinguishing Importation From Diversification Of Quinolone-Resistant Neisseria Gonorrhoeae By Molecular Evolutionary Analysis, Keith A. Crandall, Marcos Perez-Losada, Margaret C. Bash, Michael Dan, Jonathan Zenilman, Raphael P. Viscidi Jun 2007

Distinguishing Importation From Diversification Of Quinolone-Resistant Neisseria Gonorrhoeae By Molecular Evolutionary Analysis, Keith A. Crandall, Marcos Perez-Losada, Margaret C. Bash, Michael Dan, Jonathan Zenilman, Raphael P. Viscidi

Faculty Publications

Distinguishing the recent introduction of quinolone resistant gonococci into a population from diversification of resistant strains already in the population is important for planning effective infection control strategies. We applied molecular evolutionary analyses to DNA sequences from 9 housekeeping genes and gyrA, parC and porB of 24 quinolone resistant N. gonorrhoeae (QRNG) and 24 quinolone sensitive isolates collected in Israel during 2000-2001. Results- Phylogenetic and eBURST analyses and estimates of divergence time indicated QRNG were introduced on 3 separate occasions and underwent limited diversification by mutation, deletion and horizontal gene transfer. Reconstruction of N. gonorrhoeae demography showed a slowly declining …


A Direct Role Of Jh In The Control Of Imaginal Disc Formation And Growth In Manduca, J. W. Truman, K. Hiruma, J. P. Allee, S.G.B. Macwhinnie, David Champlin Ph.D., L. M. Riddiford May 2007

A Direct Role Of Jh In The Control Of Imaginal Disc Formation And Growth In Manduca, J. W. Truman, K. Hiruma, J. P. Allee, S.G.B. Macwhinnie, David Champlin Ph.D., L. M. Riddiford

Faculty Publications

No abstract provided.


The Effects Of Seeding Time On Native Plant Establishment In A Prairie Reconstruction, Dave W. Williams, Daryl D. Smith Mar 2007

The Effects Of Seeding Time On Native Plant Establishment In A Prairie Reconstruction, Dave W. Williams, Daryl D. Smith

Faculty Publications

The Iowa DOT is seeking ways to improve practices associated with revegetation projects to increase establishment of native grasses and forbs. One of these practices is to seed native grasses and forbs between Apr 01 - June 30 and between Aug. 01 - Aug. 31 (Iowa DOT 2001). We investigated seeding at different times during the growing season to determine the most appropriate seeding time for optimal establishment of prairie grasses and wildflowers.


The Effects Of Seeding Rate Of Prairie Grasses And Forbs On Native Plant Establishment In A Prairie Reconstruction. Iowa Department Of Transportation Final Report., Dave W, Williams, Daryl D. Smith Mar 2007

The Effects Of Seeding Rate Of Prairie Grasses And Forbs On Native Plant Establishment In A Prairie Reconstruction. Iowa Department Of Transportation Final Report., Dave W, Williams, Daryl D. Smith

Faculty Publications

The Iowa DOT is seeking ways to improve practices associated with revegetation projects to increase establishment of native grasses and forbs. Iowa DOT has developed various seed mixes for re-vegetation projects (Iowa DOT 2005). Each seed mix has the potential to result in a different plant community. Results from this research project will provide information on the seeding rates for species needed for optimal establishment of grasses and wildflowers in future Iowa DOT prairie plantings as well as determine if current seeding practices are adequate. This information can be used to revise or develop seeding rate recommendations for revegetation projects.


From Observers To Participants: Joining The Scientific Community, Catherine A. Reinke, Susan R. Singer, Carl Mcdaniel, Carolyn J. Ferguson, Julia Vandermeer, Adam Williamson Jan 2007

From Observers To Participants: Joining The Scientific Community, Catherine A. Reinke, Susan R. Singer, Carl Mcdaniel, Carolyn J. Ferguson, Julia Vandermeer, Adam Williamson

Faculty Publications

In this essay, we have integrated the voices of our mentors and students to explore 45 years of undergraduate research experiences and their role in shaping our scientific community. In considering our collective experiences, we see undergraduate involvement in research as a rich source of community development, one that has both touched our lives and influenced our teaching.


A New N-Terminal Recognition Domain In Caveolin-1 Interacts With Sterol Carrier Protein-2 (Scp-2), Rebecca D. Parr, Gregory G. Martin, Heather A. Hostetler, Megan E. Schroeder, Kiran D. Mir, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder Jan 2007

A New N-Terminal Recognition Domain In Caveolin-1 Interacts With Sterol Carrier Protein-2 (Scp-2), Rebecca D. Parr, Gregory G. Martin, Heather A. Hostetler, Megan E. Schroeder, Kiran D. Mir, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder

Faculty Publications

Although plasma membrane domains, such as caveolae, provide an organizing principle for signaling pathways and cholesterol homeostasis in the cell, relatively little is known regarding specific mechanisms, whereby intracellular lipid-binding proteins are targeted to caveolae. Therefore, the interaction between caveolin-1 and sterol carrier protein-2 (SCP-2), a protein that binds and transfers both cholesterol and signaling lipids (e.g., phosphatidylinositides and sphingolipids), was examined by yeast two-hybrid, in vitro binding and fluorescence resonance energy transfer (FRET) analyses. Results of the in vivo and in vitro assays identified for the first time the N-terminal amino acids (aa) 1−32 amphipathic α helix of SCP-2 …


Selective Cholesterol Dynamics Between Lipoproteins And Caveolae/Lipid Rafts, Stephen M. Storey, Adalberto M. Gallegos, Barbara P. Atshaves, Avery L. Mcintosh, Gregory G. Martin, Rebecca D. Parr, Kerstin K. Landrock, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder Jan 2007

Selective Cholesterol Dynamics Between Lipoproteins And Caveolae/Lipid Rafts, Stephen M. Storey, Adalberto M. Gallegos, Barbara P. Atshaves, Avery L. Mcintosh, Gregory G. Martin, Rebecca D. Parr, Kerstin K. Landrock, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder

Faculty Publications

Although low-density lipoprotein (LDL) receptor-mediated cholesterol uptake through clathrin-coated pits is now well understood, the molecular details and organizing principles for selective cholesterol uptake/efflux (reverse cholesterol transport, RCT) from peripheral cells remain to be resolved. It is not yet completely clear whether RCT between serum lipoproteins and the plasma membrane occurs primarily through lipid rafts/caveolae or from non-raft domains. To begin to address these issues, lipid raft/caveolae-, caveolae-, and non-raft-enriched fractions were resolved from purified plasma membranes isolated from L-cell fibroblasts and MDCK cells by detergent-free affinity chromatography and compared with detergent-resistant membranes isolated from the same cells. Fluorescent sterol …


Full-Length, Glycosylated Nsp4 Is Localized To Plasma Membrane Caveolae By A Novel Raft Isolation Technique, Stephen M. Storey, Thomas F. Gibbons, Cecelia V. Williams, Rebecca D. Parr, Friedhelm Schroeder, Judith M. Ball Jan 2007

Full-Length, Glycosylated Nsp4 Is Localized To Plasma Membrane Caveolae By A Novel Raft Isolation Technique, Stephen M. Storey, Thomas F. Gibbons, Cecelia V. Williams, Rebecca D. Parr, Friedhelm Schroeder, Judith M. Ball

Faculty Publications

Rotavirus NSP4, initially characterized as an endoplasmic reticulum intracellular receptor, is a multifunctional viral enterotoxin that induces diarrhea in murine pups. There have been recent reports of the secretion of a cleaved NSP4 fragment (residues 112 to 175) and of the association of NSP4 with LC3-positive autophagosomes, raft membranes, and microtubules. To determine if NSP4 traffics to a specific subset of rafts at the plasma membrane, we isolated caveolae from plasma membrane-enriched material that yielded caveola membranes free of endoplasmic reticulum and nonraft plasma membrane markers. Analyses of the newly isolated caveolae from rotavirus-infected MDCK cells revealed full-length, high-mannose glycosylated …


Assessment Of Genetic Diversity In The Usda And Cip-Fao International Nursery Collections Of Quinoa (Chenopodium Quinoa Willd.) Using Microsatellite Markers [Abstract], S. A. Christensen, Donald B. Pratt, C. Pratt, P. T. Nelson, M. R. Stevens, Eric N. Jellen, C. E. Coleman, D. J. Fairbanks, A. Bonifacio, Peter J. Maughan Jan 2007

Assessment Of Genetic Diversity In The Usda And Cip-Fao International Nursery Collections Of Quinoa (Chenopodium Quinoa Willd.) Using Microsatellite Markers [Abstract], S. A. Christensen, Donald B. Pratt, C. Pratt, P. T. Nelson, M. R. Stevens, Eric N. Jellen, C. E. Coleman, D. J. Fairbanks, A. Bonifacio, Peter J. Maughan

Faculty Publications

No abstract provided.


Ultrastructure Of Teliospores And Promycelium And Basidiospore Formation In The Four-Spored Form Of Gymnoconia Nitens, One Of The Causes Of Orange Rust Of Rubus, C. W. Mims, E. A. Richardson, Josephine Taylor Jan 2007

Ultrastructure Of Teliospores And Promycelium And Basidiospore Formation In The Four-Spored Form Of Gymnoconia Nitens, One Of The Causes Of Orange Rust Of Rubus, C. W. Mims, E. A. Richardson, Josephine Taylor

Faculty Publications

Orange rust of Rubus is an interesting disease because of the fact that it can be caused by three different rust fungi that produce virtually identical symptoms. One is Gymnoconia peckiana (Howe in Peck) Trotter, which is a demicyclic species, while the other two are endocyclic forms historically referred to as Gymnoconia nitens (Schwein.) Kern & H.W. Thurston. Although the spores produced on infected Rubus leaves by these latter two forms are morphologically identical to the aeciospores of G. peckiana, they actually function as teliospores. However, the teliospores of one of the forms gives rise to two-celled promycelia that …


Updated And New Amphibian And Reptile Records From Clark County, Illinois [Abstract], C. Drew Foster, Stephen J. Mullin Jan 2007

Updated And New Amphibian And Reptile Records From Clark County, Illinois [Abstract], C. Drew Foster, Stephen J. Mullin

Faculty Publications

No abstract provided.


Population Responses Of Wood Frog (Rana Sylvatica) Tadpoles To Overwintered Bullfrog (Rana Catesbeiana) Tadpoles, Leroy J. Walston, Stephen J. Mullin Jan 2007

Population Responses Of Wood Frog (Rana Sylvatica) Tadpoles To Overwintered Bullfrog (Rana Catesbeiana) Tadpoles, Leroy J. Walston, Stephen J. Mullin

Faculty Publications

A fundamental goal in ecology is to understand how environmental variation influences the distribution of individuals within a population. In this study, we used laboratory experiments to examine the population responses of sympatric Wood Frog (Rana sylvatica) tadpoles to native overwintered Bullfrog (Rana catesbeiana) tadpoles. For periods of up to two weeks, we measured growth, activity, and refuge use of Wood Frog tadpoles in small mesocosms with and without an overwintered Bullfrog tadpole present. Bullfrog tadpoles had a negative effect on the growth of Wood Frog tadpoles allotopic (naive) to Bullfrogs, whereas the presence of Bullfrogs had no effect on …


Observations On The Diets Of An Anuran And Eight Lizard Taxa From Sonora, Chihuahua, And Coahuila, Mexico, With Some Notes On Clutch Sizes, Geoffrey R. Smith, J. A. Lemos-Espinal, Christopher B. Dibble, Megan E. Ogle, Joshua J. Schulte, Andrew J. Terlecky, Allison Boyd Jan 2007

Observations On The Diets Of An Anuran And Eight Lizard Taxa From Sonora, Chihuahua, And Coahuila, Mexico, With Some Notes On Clutch Sizes, Geoffrey R. Smith, J. A. Lemos-Espinal, Christopher B. Dibble, Megan E. Ogle, Joshua J. Schulte, Andrew J. Terlecky, Allison Boyd

Faculty Publications

No abstract provided.


Threatened Fishes Of The World: Percilia Irwini (Eigenmann 1927) (Perciliidae), Evelyn Habit, Mark C. Belk Jan 2007

Threatened Fishes Of The World: Percilia Irwini (Eigenmann 1927) (Perciliidae), Evelyn Habit, Mark C. Belk

Faculty Publications

Common name: Carmelita de Concepcion (Spanish).


Biological Status Of Leatherside Chub: A Framework For Conservation Of Western Freshwater Fishes, Mark C. Belk, Jerald B. Johnson Jan 2007

Biological Status Of Leatherside Chub: A Framework For Conservation Of Western Freshwater Fishes, Mark C. Belk, Jerald B. Johnson

Faculty Publications

Outside of anadromous salmonids and a few endangered species, biology of native freshwater fishes of western North America is poorly known. What do we need to know to effectively manage native species and avoid decline and extinction? A recent analysis of the role of science in the Pacific salmon controversy outlines a clear framework for biological evaluation and management of native species. This framework has three components: (1) determine status of populations based on genetic and ecological variation, (2) identify and quantify threats to populations, and (3) determine actions to alleviate threats and promote conservation of populations. We use our …