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Biological Sciences Faculty Publications

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Articles 571 - 600 of 1156

Full-Text Articles in Biology

Direct Interaction Of Flix And Flbd Is Required For Their Regulatory Activity In Caulobacter Crescentus, Zhaohui Xu, Rachel J. Dutton, James W. Gober May 2011

Direct Interaction Of Flix And Flbd Is Required For Their Regulatory Activity In Caulobacter Crescentus, Zhaohui Xu, Rachel J. Dutton, James W. Gober

Biological Sciences Faculty Publications

Background: The temporal and spatial expression of late flagellar genes in Caulobacter crescentus is activated by the transcription factor FlbD and its partner trans-acting factor FliX. The physical interaction of these two proteins represents an alternative mechanism for regulating the activity of sigma(54) transcription factors. This study is to characterize the interaction of the two proteins and the consequences of the interaction on their regulatory activity. Results: FliX and FlbD form stable complexes, which can stand the interference of 2.65 M NaCl. The stability of FliX and FlbD was affected by the co-existence of each other. Five FliX mutants (R71A, …


The Assembly Of Ecological Communities Inferred From Taxonomic And Functional Composition, Eric R. Sokol, E. F. Benfield, Lisa K. Belden, H. Maurice Valett May 2011

The Assembly Of Ecological Communities Inferred From Taxonomic And Functional Composition, Eric R. Sokol, E. F. Benfield, Lisa K. Belden, H. Maurice Valett

Biological Sciences Faculty Publications

Among-site variation in metacommunities (beta diversity) is typically correlated with the distance separating the sites (spatial lag). This distance decay in similarity pattern has been linked to both niche-based and dispersal-based community assembly hypotheses. Here we show that beta diversity patterns in community composition, when supplemented with functional-trait information, can be used to diagnose assembly processes. First, using simulated data, we show how the relationship between distance decay patterns in taxonomic and functional measures of community composition can be used to predict the influence of a given trait on community assembly. We then use the patterns generated by the simulation …


Thinking Outside The Channel: Modeling Nitrogen Cycling In Networked River Ecosystems, Ashley M. Helton, Geoffrey C. Poole, Judy L. Meyer, Wilfred M. Wollheim, Bruce J. Peterson, Patrick J. Mulholland, Emily S. Bernhardt, Jack Arthur Stanford, Clay Arango, Linda R. Ashkenas, Lee W. Cooper, Walter K. Dodds, Stanley V. Gregory, Robert O. Hall Jr., Stephen K. Hamilton, Sherri L. Johnson, William H. Mcdowell, Jody D. Potter, Jennifer L. Tank, Suzanne M. Thomas, H. Maurice Valett, Jackson R. Webster, Lydia Zeglin May 2011

Thinking Outside The Channel: Modeling Nitrogen Cycling In Networked River Ecosystems, Ashley M. Helton, Geoffrey C. Poole, Judy L. Meyer, Wilfred M. Wollheim, Bruce J. Peterson, Patrick J. Mulholland, Emily S. Bernhardt, Jack Arthur Stanford, Clay Arango, Linda R. Ashkenas, Lee W. Cooper, Walter K. Dodds, Stanley V. Gregory, Robert O. Hall Jr., Stephen K. Hamilton, Sherri L. Johnson, William H. Mcdowell, Jody D. Potter, Jennifer L. Tank, Suzanne M. Thomas, H. Maurice Valett, Jackson R. Webster, Lydia Zeglin

Biological Sciences Faculty Publications

Agricultural and urban development alters nitrogen and other biogeochemical cycles in rivers worldwide. Because such biogeochemical processes cannot be measured empirically across whole river networks, simulation models are critical tools for understanding river-network biogeochemistry. However, limitations inherent in current models restrict our ability to simulate biogeochemical dynamics among diverse river networks. We illustrate these limitations using a river-network model to scale up in situ measures of nitrogen cycling in eight catchments spanning various geophysical and land-use conditions. Our model results provide evidence that catchment characteristics typically excluded from models may control river-network biogeochemistry. Based on our findings, we identify important …


Effects Of Soil Biota From Different Ranges On Robinia Invasion: Acquiring Mutualists And Escaping Pathogens, Ragan M. Callaway, Eulogio J. Bedmar, Kurt O. Reinhart, Cinta Gómez Silvan, John Klironomos May 2011

Effects Of Soil Biota From Different Ranges On Robinia Invasion: Acquiring Mutualists And Escaping Pathogens, Ragan M. Callaway, Eulogio J. Bedmar, Kurt O. Reinhart, Cinta Gómez Silvan, John Klironomos

Biological Sciences Faculty Publications

The net effects of soil biota on exotic invaders can be variable, in part, because net effects are produced by many interacting mutualists and antagonists. Here we compared mutualistic and antagonistic biota in soils collected in the native, expanded, and invasive range of the black locust tree, Robinia pseudoacacia. Robinia formed nodules in all soils with a broad phylogenetic range of N-fixing bacteria, and leaf N did not differ among the different sources of soil. This suggests that the global expansion of Robinia was not limited by the lack of appropriate mutualistic N-fixers. Arbuscular mycorrhizal fungi (AMF) from the …


Win-Win For Wind And Wildlife: A Vision To Facilitate Sustainable Development, Joseph M. Kiesecker, Jeffrey S. Evans, Joe Fargione, Kevin Doherty, Kerry R. Foresman, Thomas H. Kunz, David E. Naugle, Nathan P. Nibbelink, Neal D. Niemuth Apr 2011

Win-Win For Wind And Wildlife: A Vision To Facilitate Sustainable Development, Joseph M. Kiesecker, Jeffrey S. Evans, Joe Fargione, Kevin Doherty, Kerry R. Foresman, Thomas H. Kunz, David E. Naugle, Nathan P. Nibbelink, Neal D. Niemuth

Biological Sciences Faculty Publications

Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production, making appropriate siting and mitigation particularly important. Species that require large unfragmented habitats and those known to avoid vertical structures are particularly at risk from wind development. Developing energy on disturbed lands rather than placing new developments within large and intact habitats would reduce cumulative impacts to wildlife. The U.S. Department of Energy estimates that it will take 241 GW of terrestrial based wind development …


Avian Community Ecology And The Shifting Baseline In Sugarcreek Metropark, Jennifer Lynne Hays, Thomas P. Rooney, Jeffrey L. Peters Apr 2011

Avian Community Ecology And The Shifting Baseline In Sugarcreek Metropark, Jennifer Lynne Hays, Thomas P. Rooney, Jeffrey L. Peters

Biological Sciences Faculty Publications

No abstract provided.


Abundance And Trends Of Woodpecker Populations In The Wright State Biology Preserve, Brittany Damron, Thomas P. Rooney Apr 2011

Abundance And Trends Of Woodpecker Populations In The Wright State Biology Preserve, Brittany Damron, Thomas P. Rooney

Biological Sciences Faculty Publications

No abstract provided.


Carbon Sequestration In Soils Of The Wright State University Biology Preserve, Laurie Wissler, Thomas P. Rooney Apr 2011

Carbon Sequestration In Soils Of The Wright State University Biology Preserve, Laurie Wissler, Thomas P. Rooney

Biological Sciences Faculty Publications

No abstract provided.


Review Of Acanthocephala (Hemiptera: Heteroptera: Coreidae) Of America North Of Mexico With A Key To Species, J. E. Mcpherson, Richard J. Packauskas Ph.D., Robert W. Sites, Steven J. Taylor, C. Scott Bundy, Jeffrey D. Bradshaw, Paula Levin Mitchell Apr 2011

Review Of Acanthocephala (Hemiptera: Heteroptera: Coreidae) Of America North Of Mexico With A Key To Species, J. E. Mcpherson, Richard J. Packauskas Ph.D., Robert W. Sites, Steven J. Taylor, C. Scott Bundy, Jeffrey D. Bradshaw, Paula Levin Mitchell

Biological Sciences Faculty Publications

A review of Acanthocephala of America north of Mexico is presented with an updated key to species. A. confraterna is considered a junior synonym of A. terminalis, thus reducing the number of known species in this region from five to four. New state and country records are presented.


A Unique Coxiella Burnetii Lipoprotein Involved In Metal Binding (Limb), James M. Battisti, Linda D. Hicks, Michael F. Minnick Apr 2011

A Unique Coxiella Burnetii Lipoprotein Involved In Metal Binding (Limb), James M. Battisti, Linda D. Hicks, Michael F. Minnick

Biological Sciences Faculty Publications

Coxiella burnetii is the bacterial agent of Q fever in humans. Here, we describe a unique, ~7.2 kDa, surface-exposed lipoprotein involved in metal binding which we have termed LimB. LimB was initially identified as a potential metal-binding protein on far-Western (FW) blots containing whole-cell lysate proteins when probed with nickel-coated horseradish peroxidase (Ni-HRP) and developed with a chemiluminescent HRP substrate. The corresponding identity of LimB as CBU1224a was established by matrix-assisted laser desorption ionization-tandem time-of-flight mass spectrometry. blast analyses with CBU1224a showed no significant similarity to sequences outside strains of C. burnetii. Additional in silico analyses revealed a putative 20 …


Plant Invasions, Generalist Herbivores, And Novel Defense Weapons, Urs Schaffner, Wendy M. Ridenour, Vera C. Wolf, Thomas Bassett, Caroline Müller-Schärer, Steve Sutherland, Christopher J. Lortie, Ragan M. Callaway Apr 2011

Plant Invasions, Generalist Herbivores, And Novel Defense Weapons, Urs Schaffner, Wendy M. Ridenour, Vera C. Wolf, Thomas Bassett, Caroline Müller-Schärer, Steve Sutherland, Christopher J. Lortie, Ragan M. Callaway

Biological Sciences Faculty Publications

One commonly accepted mechanism for biological invasions is that species, after introduction to a new region, leave behind their natural enemies and therefore increase in distribution and abundance. However, which enemies are escaped remains unclear. Escape from specialist invertebrate herbivores has been examined in detail, but despite the profound effects of generalist herbivores in natural communities their potential to control invasive species is poorly understood. We carried out parallel laboratory feeding bioassays with generalist invertebrate herbivores from the native (Europe) and from the introduced (North America) range using native and nonnative tetraploid populations of the invasive spotted knapweed, Centaurea stoebe. …


Society For The Advancement Of Biology Education Research (Saber), Karen Sirum, Erika G. Offerdahl, Teri Balser, Clarisa Dirks, Kathryn Miller, Jennifer L. Momsen, Lisa Montplaisir, Marcy Osgood Apr 2011

Society For The Advancement Of Biology Education Research (Saber), Karen Sirum, Erika G. Offerdahl, Teri Balser, Clarisa Dirks, Kathryn Miller, Jennifer L. Momsen, Lisa Montplaisir, Marcy Osgood

Biological Sciences Faculty Publications

No abstract provided.


Preliminary Analysis Of An Agent-Based Model For A Tick-Borne Disease, Holly Gaff Apr 2011

Preliminary Analysis Of An Agent-Based Model For A Tick-Borne Disease, Holly Gaff

Biological Sciences Faculty Publications

Ticks have a unique life history including a distinct set of life stages and a single blood meal per life stage. This makes tick-host interactions more complex from a mathematical perspective. In addition, any model of these interactions must involve a significant degree of stochasticity on the individual tick level. In an attempt to quantify these relationships, I have developed an individual-based model of the interactions between ticks and their hosts as well as the transmission of tick-borne disease between the two populations. The results from this model are compared with those from previously published differential equation based population models. …


Automated Upscaling Of River Networks For Macroscale Hydrological Modeling, Huan Wu, John S. Kimball, Nate Mantua, Jack Arthur Stanford Mar 2011

Automated Upscaling Of River Networks For Macroscale Hydrological Modeling, Huan Wu, John S. Kimball, Nate Mantua, Jack Arthur Stanford

Biological Sciences Faculty Publications

We developed a hierarchical dominant river tracing (DRT) algorithm for automated extraction and spatial upscaling of basin flow directions and river networks using fine-scale hydrography inputs (e. g., flow direction, river networks, and flow accumulation). In contrast with previous upscaling methods, the DRT algorithm utilizes information on global and local drainage patterns from baseline fine-scale hydrography to determine upscaled flow directions and other critical variables including upscaled basin area, basin shape, and river lengths. The DRT algorithm preserves the original baseline hierarchical drainage structure by tracing each entire flow path from headwater to river mouth at fine scale while prioritizing …


The Forgotten Stage Of Forest Succession: Early-Successional Ecosystems On Forest Sites, Mark E. Swanson, Jerry F. Franklin, Robert L. Beschta, Charles M. Crisafulli, Dominick A. Dellasala, Richard L. Hutto, David B. Lindenmaver, Frederick J. Swanson Mar 2011

The Forgotten Stage Of Forest Succession: Early-Successional Ecosystems On Forest Sites, Mark E. Swanson, Jerry F. Franklin, Robert L. Beschta, Charles M. Crisafulli, Dominick A. Dellasala, Richard L. Hutto, David B. Lindenmaver, Frederick J. Swanson

Biological Sciences Faculty Publications

Early-successional forest ecosystems that develop after stand-replacing or partial disturbances are diverse in species, processes, and structure. Post-disturbance ecosystems are also often rich in biological legacies, including surviving organisms and organically derived structures, such as woody debris. These legacies and post-disturbance plant communities provide resources that attract and sustain high species diversity, including numerous early-successional obligates, such as certain woodpeckers and arthropods. Early succession is the only period when tree canopies do not dominate the forest site, and so this stage can be characterized by high productivity of plant species (including herbs and shrubs), complex food webs, large nutrient fluxes, …


Population Proteomics: Quantitative Variation Within And Among Populations In Cardiac Protein Expression, Bernard Rees Mar 2011

Population Proteomics: Quantitative Variation Within And Among Populations In Cardiac Protein Expression, Bernard Rees

Biological Sciences Faculty Publications

Population analysis of gene expression is typically achieved by quantifying levels of mRNA; however, gene expression is also a function of protein translation and turnover. Therefore, a complete understanding of population variation in gene expression requires quantitative knowledge of protein expression within and among natural populations. We used two dimensional fluorescence difference gel electrophoresis (2D-DIGE) to quantitatively compare expression of heart ventricle proteins among 18 individuals in three populations of the teleost fish Fundulus. Among populations, expressions between orthologous proteins and mRNAs were generally positively correlated. Additionally, similar to the pattern of cardiac mRNA expression for the same populations, we …


A Specific Interaction Of Small Molecule Entry Inhibitors With The Envelope Glycoprotein Complex Of The Junín Hemorrhagic Fever Arenavirus, Celestine J. Thomas, Hedi E. Casquilho-Gray, Joanne York, Dianne L. Decamp, Dongcheng Dai, Erin B. Petrilli, Dale L. Boger, Richard A. Slayden, Sean M. Amberg, Stephen Sprang, Jack H. Nunberg Feb 2011

A Specific Interaction Of Small Molecule Entry Inhibitors With The Envelope Glycoprotein Complex Of The Junín Hemorrhagic Fever Arenavirus, Celestine J. Thomas, Hedi E. Casquilho-Gray, Joanne York, Dianne L. Decamp, Dongcheng Dai, Erin B. Petrilli, Dale L. Boger, Richard A. Slayden, Sean M. Amberg, Stephen Sprang, Jack H. Nunberg

Biological Sciences Faculty Publications

Arenaviruses are responsible for acute hemorrhagic fevers worldwide and are recognized to pose significant threats to public health and biodefense. Small molecule compounds have recently been discovered that inhibit arenavirus entry and protect against lethal infection in animal models. These chemically distinct inhibitors act on the tripartite envelope glycoprotein (GPC) through its unusual stable signal peptide subunit to stabilize the complex against pH-induced activation of membrane fusion in the endosome. Here, we report the production and characterization of the intact transmembrane GPC complex of Junín arenavirus and its interaction with these inhibitors. The solubilized GPC is antigenically indistinguishable from the …


Volatile Chemicals From Leaf Litter Are Associated With Invasiveness Of A Neotropical Weed In Asia, Inderjit, Heather Evans, Christoph Crocoll, Devika Bajpai, Rajwant Kaur, Yu-Long Feng, Carlos Silva, Jacinto Treviño Carreón, Alfonso Valiente-Banuet, Jonathan Gershenzon, Ragan M. Callaway Feb 2011

Volatile Chemicals From Leaf Litter Are Associated With Invasiveness Of A Neotropical Weed In Asia, Inderjit, Heather Evans, Christoph Crocoll, Devika Bajpai, Rajwant Kaur, Yu-Long Feng, Carlos Silva, Jacinto Treviño Carreón, Alfonso Valiente-Banuet, Jonathan Gershenzon, Ragan M. Callaway

Biological Sciences Faculty Publications

Some invasive plant species appear to strongly suppress neighbors in their nonnative ranges but much less so in their native range. We found that in the field in its native range in Mexico, the presence of Ageratina adenophora, an aggressive Neotropical invader, was correlated with higher plant species richness than found in surrounding plant communities where this species was absent, suggesting facilitation. However, in two nonnative ranges, China and India, A. adenophora canopies were correlated with much lower species richness than the surrounding communities, suggesting inhibition. Volatile organic compound (VOC) signals may contribute to this striking biogeographical difference and …


Latitudinal Variation In Top-Down And Bottom-Up Control Of A Salt Marsh Food Web, Laurie B. Marczak, C.-K. Ho, K. Wieski, H. Vu, R. F. Denno, S. C. Pennings Feb 2011

Latitudinal Variation In Top-Down And Bottom-Up Control Of A Salt Marsh Food Web, Laurie B. Marczak, C.-K. Ho, K. Wieski, H. Vu, R. F. Denno, S. C. Pennings

Biological Sciences Faculty Publications

The shrub Iva frutescens, which occupies the terrestrial border of U.S. Atlantic Coast salt marshes, supports a food web that varies strongly across latitude. We tested whether latitudinal variation in plant quality (higher at high latitudes), consumption by omnivores (a crab, present only at low latitudes), consumption by mesopredators (ladybugs, present at all latitudes), or the life history stage of an herbivorous beetle could explain continental-scale field patterns of herbivore density. In a mesocosm experiment, crabs exerted strong top-down control on herbivorous beetles, ladybugs exerted strong top-down control on aphids, and both predators benefited plants through trophic cascades. Latitude …


Floodplain Succession And Soil Nitrogen Accumulation On A Salmon River In Southwestern Kamchatka, Michael R. Morris, Jack Arthur Stanford Feb 2011

Floodplain Succession And Soil Nitrogen Accumulation On A Salmon River In Southwestern Kamchatka, Michael R. Morris, Jack Arthur Stanford

Biological Sciences Faculty Publications

We documented riparian primary succession on an expansive floodplain (Kol River, Kamchatka, Russian Federation) that receives large nitrogen subsidies from spawning Pacific salmon. As is typical of primary succession, new alluvial deposits in the lower Kol floodplain were nitrogen poor (200 kg persulfate N/ha to 10 cm soil depth); however, nitrogen accumulated rapidly, and soils contained 1600 kg N/ha (to 10 cm + the litter layer) by 20 years. Soil nitrogen approached an asymptote at 2500 kg N/ha by 80 years. Nitrogen-fixing Alnus trees were a minor component of the forest community during the first 20 years of succession. However, …


T-705 (Favipiravir) Inhibition Of Arenavirus Replication In Cell Culture, Michelle Mendenhall, Andrew Russell, Terry Juelich, Emily L. Messina, Donald F. Smee, Alexander N. Freiberg, Michael R. Holbrook, Yousuke Furuta, Juan-Carlos De La Torre, Jack H. Nunberg, Brian B. Gowen Feb 2011

T-705 (Favipiravir) Inhibition Of Arenavirus Replication In Cell Culture, Michelle Mendenhall, Andrew Russell, Terry Juelich, Emily L. Messina, Donald F. Smee, Alexander N. Freiberg, Michael R. Holbrook, Yousuke Furuta, Juan-Carlos De La Torre, Jack H. Nunberg, Brian B. Gowen

Biological Sciences Faculty Publications

A number of New World arenaviruses (Junin [JUNV], Machupo [MACV], and Guanarito [GTOV] viruses) can cause human disease ranging from mild febrile illness to a severe and often fatal hemorrhagic fever syndrome. These highly pathogenic viruses and the Old World Lassa fever virus pose a significant threat to public health and national security. The only licensed antiviral agent with activity against these viruses, ribavirin, has had mixed success in treating severe arenaviral disease and is associated with significant toxicities. A novel pyrazine derivative currently in clinical trials for the treatment of influenza virus infections, T-705 (favipiravir), has demonstrated broad-spectrum activity …


Soil Microbes Drive The Classic Plant Diversity-Productivity Pattern, Stefan A. Schnitzer, John N. Klironomos, Janneke Hillerislambers, Linda L. Kinkel, Peter B. Reich, Kun Xiao, Matthias C. Rillig, Benjamin A. Sikes, Ragan M. Callaway, Scott A. Mangan, Egbert H. Van Nes, Marten Scheffer Feb 2011

Soil Microbes Drive The Classic Plant Diversity-Productivity Pattern, Stefan A. Schnitzer, John N. Klironomos, Janneke Hillerislambers, Linda L. Kinkel, Peter B. Reich, Kun Xiao, Matthias C. Rillig, Benjamin A. Sikes, Ragan M. Callaway, Scott A. Mangan, Egbert H. Van Nes, Marten Scheffer

Biological Sciences Faculty Publications

Volume 92, Issue 2 (February)

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< Previous Article Next Article> Volume 92, Issue 2 (February 2011)

Stefan A. Schnitzer, John N. Klironomos, Janneke HilleRisLambers, Linda L. Kinkel, Peter B. Reich, Kun Xiao, Matthias C. Rillig, Benjamin A. Sikes, …


Is Wildlife Going To The Dogs? Impacts Of Feral And Free-Roaming Dogs On Wildlife Populations, Julie K. Young, Kirk A. Olson, Richard P. Reading, Sukh Amgalanbaatar, Joel Berger Feb 2011

Is Wildlife Going To The Dogs? Impacts Of Feral And Free-Roaming Dogs On Wildlife Populations, Julie K. Young, Kirk A. Olson, Richard P. Reading, Sukh Amgalanbaatar, Joel Berger

Biological Sciences Faculty Publications

In human-populated landscapes, dogs (Canis familiaris) are often the most abundant terrestrial carnivore. However, dogs can significantly disrupt or modify intact ecosystems well beyond the areas occupied by people. Few studies have directly quantified the environmental or economic effects of free-roaming and feral dogs. Here, we review wildlife-dog interactions and provide a case study that focuses on interactions documented from our research in Mongolia to underscore the need for studies designed to best determine how dogs affect native wildlife and especially imperiled populations. We suggest additional research, public awareness campaigns, and the exclusion of dogs from critical wildlife habitat. The …


Oxygen Limitation And Tissue Metabolic Potential Of The African Fish Barbus Neumayeri: Roles Of Native Habitat And Acclimatization, Bernard Rees Jan 2011

Oxygen Limitation And Tissue Metabolic Potential Of The African Fish Barbus Neumayeri: Roles Of Native Habitat And Acclimatization, Bernard Rees

Biological Sciences Faculty Publications

Oxygen availability in aquatic habitats is a major environmental factor influencing the ecology, behaviour, and physiology of fishes. This study evaluates the contribution of source population and hypoxic acclimatization of the African fish, Barbus neumayeri, in determining growth and tissue metabolic enzyme activities. Individuals were collected from two sites differing dramatically in concentration of dissolved oxygen (DO), Rwembaita Swamp (annual average DO 1.35 mgO2 L-1) and Inlet Stream West (annual average DO 5.58 mgO2 L-1) in Kibale National Park, Uganda, and reciprocally transplanted using a cage experiment in the field, allowing us to …


Cell Signalling: Binding The Receptor At Both Ends, Stephen R. Sprang Jan 2011

Cell Signalling: Binding The Receptor At Both Ends, Stephen R. Sprang

Biological Sciences Faculty Publications

G-protein-coupled receptors initiate a wide range of signalling pathways in cells. It seems that both a G protein and an agonist molecule must bind to the receptors to persistently activate them.


Modulation Of A Gef Switch: Autoinhibition Of The Intrinsic Guanine Nucleotide Exchange Activity Of P115-Rhogef, Zhe Chen, Liang Guo, Stephen R. Sprang, Paul C. Sternweis Jan 2011

Modulation Of A Gef Switch: Autoinhibition Of The Intrinsic Guanine Nucleotide Exchange Activity Of P115-Rhogef, Zhe Chen, Liang Guo, Stephen R. Sprang, Paul C. Sternweis

Biological Sciences Faculty Publications

p115-RhoGEF (p115) belongs to the family of RGS-containing guanine nucleotide exchange factors for Rho GTPases (RGS-RhoGEFs) that are activated by G12 class heterotrimeric G protein α subunits. All RGS-RhoGEFs possess tandemly linked Dbl-homology (DH) and plekstrin-homology (PH) domains, which bind and catalyze the exchange of GDP for GTP on RhoA. We have identified that the linker region connecting the N-terminal RGS-homology (RH) domain and the DH domain inhibits the intrinsic guanine nucleotide exchange (GEF) activity of p115, and determined the crystal structures of the DH/PH domains in the presence or absence of the inhibitory linker region. An N-terminal extension of …


Use Of Microcalorimetry To Determine The Costs And Benefits To Pseudomonas Putida Strain Kt2440 Of Harboring Cadmium Efflux Genes, Sean M. Gibbons, Kevin Feris, Michele A. Mcguirl, Sergio E. Morales, Anu Hynninen, Philip W. Ramsey, James E. Gannon Jan 2011

Use Of Microcalorimetry To Determine The Costs And Benefits To Pseudomonas Putida Strain Kt2440 Of Harboring Cadmium Efflux Genes, Sean M. Gibbons, Kevin Feris, Michele A. Mcguirl, Sergio E. Morales, Anu Hynninen, Philip W. Ramsey, James E. Gannon

Biological Sciences Faculty Publications

A novel microcalorimetric approach was used to analyze the responses of a metal-tolerant soil bacterium (Pseudomonas putida strain KT2440) to metal resistance gene deletions in cadmium-amended media. As hypothesized, under cadmium stress, the wild-type strain benefited from the resistance genes by entering the exponential growth phase earlier than two knockout strains. In the absence of cadmium, strain KT1, carrying a deletion in the main component (czcA1) of a Cd/Zn chemiosmotic efflux transporter (CzcCBA1), grew more efficiently than the wild type and released similar to 700 kJ (per mole of biomass carbon) less heat than the wild-type strain, showing the energetic …


Dynamics Of Gene Duplication In The Genomes Of Chlorophyll D-Producing Cyanobacteria: Implications For The Ecological Niche, Scott R. Miller, A. Michelle Wood, Robert E. Blankenship, Maria Kim, Steven Ferriera Jan 2011

Dynamics Of Gene Duplication In The Genomes Of Chlorophyll D-Producing Cyanobacteria: Implications For The Ecological Niche, Scott R. Miller, A. Michelle Wood, Robert E. Blankenship, Maria Kim, Steven Ferriera

Biological Sciences Faculty Publications

Gene duplication may be an important mechanism for the evolution of new functions and for the adaptive modulation of gene expression via dosage effects. Here, we analyzed the fate of gene duplicates for two strains of a novel group of cyanobacteria (genus Acaryochloris) that produces the far-red light absorbing chlorophyll d as its main photosynthetic pigment. The genomes of both strains contain an unusually high number of gene duplicates for bacteria. As has been observed for eukaryotic genomes, we find that the demography of gene duplicates can be well modeled by a birth-death process. Most duplicated Acaryochloris genes are of …


Effects Of Xs® Energy Drink On Aerobic Exercise Capacity Of Athletes, Kevin M. Sheehan, Lynn K. Hartzler Jan 2011

Effects Of Xs® Energy Drink On Aerobic Exercise Capacity Of Athletes, Kevin M. Sheehan, Lynn K. Hartzler

Biological Sciences Faculty Publications

A small increase in performance is often the difference between winning and losing for athletes, and energy supplements are marketed to give them a competitive edge. One such supplement is XS® Energy Drink which contains B vitamins, caffeine, taurine, and an herbal adaptogen blend. XS® Energy Drink is primarily designed and marketed as an alertness stimulus; however, it is also marketed to athletes as a performance enhancing supplement. The hypothesis of this investigation was that the consumption of XS® Energy Drink before exercise would increase aerobic capacity (an increase in Vo2max) and time to fatigue, and would decrease time for …


On Characterizing Adaptive Events Unique To Modern Humans, Jessica L. Crisci, Alex Wong, Jeffrey M. Good, Jeffrey D. Jensen Jan 2011

On Characterizing Adaptive Events Unique To Modern Humans, Jessica L. Crisci, Alex Wong, Jeffrey M. Good, Jeffrey D. Jensen

Biological Sciences Faculty Publications

Ever since the first draft of the human genome was completed in 2001, there has been increased interest in identifying genetic changes that are uniquely human, which could account for our distinct morphological and cognitive capabilities with respect to other apes. Recently, draft sequences of two extinct hominin genomes, a Neanderthal and Denisovan, have been released. These two genomes provide a much greater resolution to identify human-specific genetic differences than the chimpanzee, our closest extant relative. The Neanderthal genome paper presented a list of regions putatively targeted by positive selection around the time of the human-Neanderthal split. We here seek …