Digital Commons Network^™

The Role Of Msa In Staphylococcus Aureus Biofilm Formation, Karthik Sambanthamoorthy, Antony Schwartz, Vijayaraj Nagarajan, Mohamed O. Elasri

Faculty Publications

Background

Staphylococcus aureus is an important pathogen that forms biofilms. The global regulator sarA is essential for biofilm formation. Since the modulator of sarA (msa) is required for full expression of sarA and regulates several virulence factors, we examined the capacity of the msa mutant to form biofilm.

Results

We found that mutation of msa results in reduced expression of sarA in biofilm and that the msa mutant formed a weak and unstable biofilm. The msa mutant is able to adhere to surfaces and begins to form biofilm but fails to mature indicating that the defect of the …

Effect Of Linker Structure On Surface Density Of Aptamer Monolayers And Their Corresponding Protein Binding Efficiency, Subramanian Balamurugan, Anne Obubuafo, Robin L. Mccarley, Steven A. Soper, David A. Spivak

Faculty Publications

A systematic study is reported on the effect of linker size and its chemical composition toward ligand binding to a surface-immobilized aptamer, measured using surface plasmon resonance. The results, using thrombin as the model system, showed that as the number of thymidine (T) units in the linker increases from 0 to 20 in four separate increments (T0, T 5, T10, T20), the surface density of the aptamer decreased linearly from approximately 25 to 12 pmol·cm -2. The decrease in aptamer surface density occurred due to the increased size of the linker molecules. In addition, thrombin binding capacity was shown to …

Uva-Induced Photo Recovery During Early Zebrafish Embryogenesis, Qiaoxiang Dong, W. Todd Monroe, Terrence R. Tiersch, Kurt R. Svoboda

Faculty Publications

DNA photorepair has been widely studied in simple aquatic organisms that live in the marine environment, but is less understood in more complex species that live in freshwater. In the present study, we evaluated UVA-induced DNA photo recovery in embryonic stages of zebrafish, Danio rerio, a freshwater model species. Evaluation of UVB exposure and UVA photo recovery of zebrafish embryos revealed different UVB tolerances and capacities for UVA photo recovery at different stages of development. Effective UVA photo recovery was observed at 3 h post-fertilization (hpf), 6-7 hpf, and 12 hpf, but not in the early cleavage stage (2-32 cells). …

Identification Of Adropin As A Secreted Factor Linking Dietary Macronutrient Intake With Energy Homeostasis And Lipid Metabolism, K. Ganesh Kumar, James L. Trevaskis, Daniel D. Lam, Gregory M. Sutton, Robert A. Koza, Vladimir N. Chouljenko, Konstantin G. Kousoulas, Pamela M. Rogers, Robert A. Kesterson, Marie Thearle, Anthony W. Ferrante, Randall L. Mynatt, Thomas P. Burris, Jesse Z. Dong, Heather A. Halem, Michael D. Culler, Lora K. Heisler, Jacqueline M. Stephens, Andrew A. Butler

Faculty Publications

Obesity and nutrient homeostasis are linked by mechanisms that are not fully elucidated. Here we describe a secreted protein, adropin, encoded by a gene, Energy Homeostasis Associated (Enho), expressed in liver and brain. Liver Enho expression is regulated by nutrition: lean C57BL/6J mice fed high-fat diet (HFD) exhibited a rapid increase, while fasting reduced expression compared to controls. However, liver Enho expression declines with diet-induced obesity (DIO) associated with 3 months of HFD or with genetically induced obesity, suggesting an association with metabolic disorders in the obese state. In DIO mice, transgenic overexpression or systemic adropin treatment attenuated hepatosteatosis and …

Identification Of Adropin As A Secreted Factor Linking Dietary Macronutrient Intake With Energy Homeostasis And Lipid Metabolism, K. Ganesh Kumar, James L. Trevaskis, Daniel D. Lam, Gregory M. Sutton, Robert A. Koza, Vladimir N. Chouljenko, Konstantin G. Kousoulas, Pamela M. Rogers, Robert A. Kesterson, Marie Thearle, Anthony W. Ferrante, Randall L. Mynatt, Thomas P. Burris, Jesse Z. Dong, Heather A. Halem, Michael D. Culler, Lora K. Heisler, Jacqueline M. Stephens, Andrew A. Butler

Faculty Publications

Obesity and nutrient homeostasis are linked by mechanisms that are not fully elucidated. Here we describe a secreted protein, adropin, encoded by a gene, Energy Homeostasis Associated (Enho), expressed in liver and brain. Liver Enho expression is regulated by nutrition: lean C57BL/6J mice fed high-fat diet (HFD) exhibited a rapid increase, while fasting reduced expression compared to controls. However, liver Enho expression declines with diet-induced obesity (DIO) associated with 3 months of HFD or with genetically induced obesity, suggesting an association with metabolic disorders in the obese state. In DIO mice, transgenic overexpression or systemic adropin treatment attenuated hepatosteatosis and …

Geographic, Seasonal, And Precipitation Chemistry Influence On The Abundance And Activity Of Biological Ice Nucleators In Rain And Snow, Brent C. Christner, Rongman Cai, Cindy E. Morris, Kevin S. Mccarter, Christine M. Foreman, Mark L. Skidmore, Scott N. Montross, David C. Sands

Faculty Publications

Biological ice nucleators (IN) function as catalysts for freezing at relatively warm temperatures (warmer than -10°C). We examined the concentration (per volume of liquid) and nature of IN in precipitation collected from Montana and Louisiana, the Alps and Pyrenees (France), Ross Island (Antarctica), and Yukon (Canada). The temperature of detectable ice-nucleating activity for more than half of the samples was ≥ -5°C based on immersion freezing testing. Digestion of the samples with lysozyme (i.e., to hydrolyze bacterial cell walls) led to reductions in the frequency of freezing (0-100%); heat treatment greatly reduced (95% average) or completely eliminated ice nucleation at …

Development Of Theta Rhythmicity In Entorhinal Stellate Cells Of The Juvenile Rat., Burton Bg, Economo Mn, Lee Gj, White Ja

Faculty Publications

No abstract provided.

Escherichia Coli Ftna Acts As An Iron Buffer For Re-Assembly Of Iron-Sulfur Clusters In Response To Hydrogen Peroxide Stress, Jacob P. Bitoun, Genfu Wu, Huangen Ding

Faculty Publications

Iron-sulfur clusters are one of the most ubiquitous redox centers in biology. Ironically, iron-sulfur clusters are highly sensitive to reactive oxygen species. Disruption of iron-sulfur clusters will not only change the activity of proteins that host iron-sulfur clusters, the iron released from the disrupted iron-sulfur clusters will further promote the production of deleterious hydroxyl free radicals via the Fenton reaction. Here, we report that ferritin A (FtnA), a major iron-storage protein in Escherichia coli, is able to scavenge the iron released from the disrupted iron-sulfur clusters and alleviates the production of hydroxyl free radicals. Furthermore, we find that the iron …

The Effect Of Chromium Propionate On Growth Performance And Carcass Traits In Broilers, A. R. Jackson, S. Powell, S. Johnston, J. L. Shelton, T. D. Bidner, F. R. Valdez, L. L. Southern

Faculty Publications

Chromium has been considered by many nutritionists as an essential nutrient for animals and humans. Research on the use of Cr from organic sources in poultry is limited. Two experiments were conducted to determine the effects of dietary addition of 0, 200, 400, or 800 ppb Cr as chromium propionate on growth performance and carcass traits in 0- to 42- or 0- to 49-d-old broilers. The results of these experiments indicate that Cr as chromium propionate improved feed efficiency in the later phases of growth and decreased mortality in one experiment but not another. Also, chromium propionate supplementation had no …

2-(3-Methyl-2-Nitrophenyl)-4,5-Dihydro-1,3-Oxazole, Dongwei Lei, Huibin Yang, Bin Li, Zhuo Kang

Faculty Publications

In the title compound, C10H10N2O3, an inter-mediate in the synthesis of anthranilamide insecticides, all the non-H atoms except the nitro-group O atom lie on a crystallographic mirror plane. The H atoms of the methyl group are disordered over two sets of sites with equal occupancies. In the crystal structure, C - H⋯N links lead to chains of mol-ecules propagating in [100].

Host-Pathogen Interactions, Insect Outbreaks, And Natural Selection For Disease Resistance, Bret D. Elderd, Jonathan Dushoff, Greg Dwyer

Faculty Publications

The theory of insect population dynamics has shown that heterogeneity in natural-enemy attack rates is strongly stabilizing. We tested the usefulness of this theory for outbreaking insects, many of which are attacked by infectious pathogens. We measured heterogeneity among gypsy moth larvae in their risk of infection with a nucleopolyhedrovirus, which is effectively heterogeneity in the pathogen's attack rate. Our data show that heterogeneity in infection risk in this insect is so high that it leads to a stable equilibrium in the models, which is inconsistent with the outbreaks seen in North American gypsy moth populations. Our data further suggest …

Leucon (Crymoleucon) Rossi, A New Species (Crustacea: Cumacea: Leuconidae) From The Shelf Waters Of The Ross Sea (Antarctica), With A Key To The Genus Leucon South Of 60°S, Peter Rehm, Richard W. Heard

Faculty Publications

A new leuconid cumacean, Leucon (Crymoleucon) rossi n. sp., is described from depths of 84 to 458 m in the Ross Sea off the Victoria Land coast. Leucon rossi n. sp. is distinguished from other members of the genus by a combination of characters including 1) a blunt, horizontally directed pseudorostrum) Without a distinctly protruding siphon; 2) strongly developed antennal notch; 3) entire dorsomedian margin of carapace appearing serrate, armed with 14 to 19 anteriorly Curved spines in female (up to 21 in subadult males); 4) a small, but distinct, spine behind the frontal lobe; and 5) the uropodal peduncle …

Gene Order Phylogeny Of The Genus Prochlorococcus, Haiwei Luo, Jian Shi, William Arndt, Jijun Tang, Robert Friedman

Faculty Publications

Background
Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria.

Methodology/Principal Findings
Orthologous gene sets and their genomic positions were identified from 12 species of Prochlorococcus and 1 outgroup species of Synechococcus. From this data, inversion and breakpoint distance-based phylogenetic trees were computed by GRAPPA and FastME. Statistical support of the resulting topology was obtained by application of a 50% jackknife resampling technique. The result was consistent and congruent with nucleotide sequence-based and gene-content based …

Biological Invasions And Biocultural Diversity: Linking Ecological And Cultural Systems, Jeanine Pfeiffer, Robert Voeks

Faculty Publications

Study of the ecological and economic effects of invasive species has paralleled their progressively pervasive influence worldwide, yet their cultural impacts remain largely unexamined and therefore unrecognized. Unlike biological systems, where the ecological consequences of biological invasions are primarily negative, from an ethnoscientific standpoint, invasive species' impacts on cultural systems span a range of effects. Biological invasions affect cultural groups in myriad, often unpredictable and at times contradictory ways. This review groups case studies into a conceptual matrix suggesting three categorically different cultural impacts of invasive species. Culturally impoverishing invasive species precipitate the loss or replacement of culturally important native …

Centers For Oceans And Human Health: Contributions To An Emerging Discipline, Edward A. Laws, Lora E. Fleming, John J. Stegeman

Faculty Publications

No abstract provided.

Impacts Of Climate Variability And Future Climate Change On Harmful Algal Blooms And Human Health, Stephanie K. Moore, Vera L. Trainer, Nathan J. Mantua, Micaela S. Parker, Edward A. Laws, Lorraine C. Backer, Lora E. Fleming

Faculty Publications

Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implicated in recent climate change, and are projected to substantially impact the climate on a global scale in the future. For marine and freshwater systems, increasing concentrations of greenhouse gases are expected to increase surface temperatures, lower pH, and cause changes to vertical mixing, upwelling, precipitation, and evaporation patterns. The potential consequences of these changes for harmful algal blooms (HABs) have received relatively little attention and are not well understood. Given the apparent increase in HABs around the world and the potential for greater problems as a result of climate change …

Timing Of Supplementation Of Selenium And Isoflavones Determines Prostate Cancer Risk Factor Reduction In Rats, Merrill J. Christensen, Jessica R. Tolman, Edwin D. Lephart, Dennis L. Eggett, Kenneth Setchell

Faculty Publications

High dietary intake of selenium or isoflavones reduces risk factors for prostate cancer. We tested whether combined supplementation of these two dietary components would reduce prostate cancer risk factors in rats more than supplementation of each component individually. Methods Male Noble rat pups were exposed from conception to diets containing an adequate (0.33-0.45 mg/kg diet) or high (3.33-3.45 mg/kg) concentration of selenium as Se-methylselenocysteine and a low (10 mg/kg) or high (600 mg/kg) level of isoflavones in a 2 x 2 factorial design. Pups consumed their respective diets until sacrifice at 35, 100, or 200 days. Male Noble rat breeders, …

Improving Reversal Median Computation Using Commuting Reversals And Cycle Information, William Arndt, Jijun Tang

Faculty Publications

In the past decade, genome rearrangements have attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. Methods for reconstructing phylogeny from genome rearrangements include distance-based methods, MCMC methods, and direct optimization methods. The latter, pioneered by Sankoff and extended with the software suites GRAPPA and MGR, is the most accurate approach, but is very limited due to the difficulty of its scoring procedure—it must solve multiple instances of the reversal median problem to compute the score of a given tree. The reversal median problem is known to be NP-hard and all …

Identification Of A Functionally Essential Amino Acid For Arabidopsis Cyclic Nucleotide Gated Ion Channels Using The Chimeric Atcngc11/12 Gene, Joyce Baxter, Wolfgang Moeder, William Urquhart, Dea Shahinas, Kimberley Chin, Dinesh Christendat, Hong Gu Kang, Magdalena Angelova, Naohiro Kato, Keiko Yoshioka

Faculty Publications

We used the chimeric Arabidopsis cyclic nucleotide-gated ion channel AtCNGC11/12 to conduct a structure-function study of plant cyclic nucleotide-gated ion channels (CNGCs). AtCNGC11/12 induces multiple pathogen resistance responses in the Arabidopsis mutant constitutive expresser of PR genes 22 (cpr22). A genetic screen for mutants that suppress cpr22-conferred phenotypes identified an intragenic mutant, #73, which has a glutamate to lysine substitution (E519K) at the beginning of the eighth β-sheet of the cyclic nucleotide-binding domain in AtCNGC11/12. The #73 mutant is morphologically identical to wild-type plants and has lost cpr22-related phenotypes including spontaneous cell death and enhanced pathogen resistance. Heterologous expression analysis …

Central Blockade Of Oxytocin Receptors During Mid-Late Gestation Reduces Amplitude Of Slow Afterhyperpolarization In Supraoptic Oxytocin Neurons, R. Teruyama, D. L. Lipschitz, L. Wang, G. R. Ramoz, W. R. Crowley, S. L. Bealer, W. E. Armstrong

Faculty Publications

The neurohypophysial hormone oxytocin (OT), synthesized in magnocellular paraventricular (PVN) and supraoptic (SON) nuclei, is well known for its effects in lactation. Our previous studies showed that central OT receptor (OTR) binding is increased during gestation and that blockade of central OTRs, specifically during mid-late gestation, causes a delay in OT release during suckling and reduces weight gain in pups, suggesting decreased milk delivery. In the present study, we tested whether central OTR blockade during late gestation disrupts the gestation-related plasticity in intrinsic membrane properties. Whole cell current-clamp recordings were performed in OT neurons from pregnant rats (19-22 days in …

Effects Of M-Tyrosine On Feeding And Survival Of Formosan Subterranean Termites (Isoptera: Rhinotermitidae), Bal K. Gautam, Gregg Henderson

Faculty Publications

Amino acids are important to all animal life. Termites rely mainly on microorganisms to retrieve these nitrogen sources from their food. One naturally occurring amino acid, m-tyrosine, has been reported to be toxic to bacteria and weeds. Its direct effects on termite survival are unknown however. Both no-choice and choice bioassays using five different doses of m-tyrosine were conducted to determine the feeding response and survival of Formosan subterranean termites, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in the laboratory. In no-choice tests, although all doses of m-tyrosine tested reduced filter paper consumption, only the highest dose tested (0.05 M) had significantly …

Dietary Resistant Starch Upregulates Total Glp-1 And Pyy In A Sustained Day-Long Manner Through Fermentation In Rodents, June Zhou, Roy J. Martin, Richard T. Tulley, Anne M. Raggio, Kathleen L. Mccutcheon, Li Shen, Samuel Colby Danna, Sasmita Tripathy, Maren Hegsted, Michael J. Keenan

Faculty Publications

Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are anti-diabetes/obesity hormones ecreted from the gut after meal ingestion. We have shown that dietary-resistant starch (RS) increased GLP-1 and PYY secretion, but he mechanism remains unknown. RS is a fermentable fiber that lowers the glycemic index of the diet and liberates short-chain fatty acids (SCFAs) through fermentation in the gut. This study investigates the two possible mechanisms by which RS stimulates GLP-1 and PYY secretion: the effect of a meal or glycemic index, and the effect of fermentation. Because GLP-1 and PYY secretions are stimulated by nutrient availability in the gut, the …

The Battle Of Morgarten In 1315: An Essential Incident In The Founding Of The Swiss State, Albert Winkler

Faculty Publications

In 1315 Leopold I of the Habsburg family led an army invaded the early Swiss states of Uri, Schwyz, and Unterwalden. Leopold’s army was typical feudal force and included many knights on horseback. The Swiss states were largely free peasants who were developing infantry tactics, and the conflict with the Habsburgs was in part a social conflict. In one of the most stunning and lopsided military victories in history, the Swiss overwhelmed and routed Leopold’s army at the Pass at Morgarten. Within days, the victorious Swiss states concluded the Pact of Brunnen which was a major step in cooperation between …

Numerical Simulation Of Local Temperature Distortions During Ice Nucleation Of Cells In Suspension, D. Kandra, R. V. Devireddy

Faculty Publications

Knowledge of intercellular ice formation in cells embedded in an extra-cellular suspension is essential for effective design of freezing protocols. The presence of cell membrane causes super-cooling of the intra-cellular region, which nucleates at much lower temperatures than the surrounding extra-cellular space and is accompanied by the exothermic release of the latent heat. This is a dynamic process and causes thermal distortions in and around the cell where nucleation occurs. In the present study, an attempt has been made to numerically determine the magnitude of thermal distortion (ΔT) and the time (dt) it takes for this distortion to damp out …

Neuroimaging And Recovery Of Language In Aphasia, Cynthia K. Thompson, Dirk B. Den Ouden

Faculty Publications

The use of functional neuroimaging techniques has advanced what is known about the neural mechanisms used to support language processing in aphasia resulting from brain damage. This paper highlights recent findings derived from neuroimaging studies focused on neuroplasticity of language networks, the role of the left and right hemispheres in this process, and studies examining how treatment affects the neurobiology of recovery. We point out variability across studies as well as factors related to this variability, and we emphasize challenges that remain for research.

Cardiorespiratory Fitness As A Predictor Of Fatal And Nonfatal Stroke In Asymptomatic Women And Men, Steven P. Hooker, Xuemei Sui, Natalie Colabianchi, John E. Vena, James N. Laditka, Michael J. Lamonte, Steven N. Blair

Faculty Publications

Background and Purpose - Prospective data on the association between cardiorespiratory fitness (CRF) and stroke are largely limited to studies in men or do not separately examine risks for fatal and nonfatal stroke. This study examined the association between CRF and fatal and nonfatal stroke in a large cohort of asymptomatic women and men.

Methods - A total of 46,405 men and 15,282 women without known myocardial infarction or stroke at baseline completed a maximal treadmill exercise test between 1970 and 2001. CRF was grouped as quartiles of the sex-specific distribution of maximal metabolic equivalents achieved. Mortality follow-up was through …

The Unconscionability Game: Strategic Judging And The Development Of Federal Arbitration Law, Aaron-Andrew P. Bruhl

Faculty Publications

This Article uses recent developments in the enforcement of arbitration agreements to illustrate one way in which strategic dynamics can drive doctrinal change. In a fairly short period of time, arbitration has grown from a method of resolving disputes between sophisticated business entities into a phenomenon that pervades the contemporary economy. The United States Supreme Court has encouraged this transformation through expansive interpretations of the Federal Arbitration Act. But not all courts have embraced arbitration so fervently, and therefore case law in this area is marked by tension and conflict. The thesis of this Article is that we can better …

Drought Stress And Preharvest Aflatoxin Contamination In Agricultural Commodity: Genetics, Genomics And Proteomics, Baozhu Guo, Zhi Yuan Chen, R. Dewey Lee, Brian T. Scully

Faculty Publications

Throughout the world, aflatoxin contamination is considered one of the most serious food safety issues concerning health. Chronic problems with preharvest aflatoxin contamination occur in the southern US, and are particularly troublesome in corn, peanut, cottonseed, and tree nuts. Drought stress is a major factor to contribute to preharvest aflatoxin contamination. Recent studies have demonstrated higher concentration of defense or stress-related proteins in corn kernels of resistant genotypes compared with susceptible genotypes, suggesting that preharvest field condition (drought or not drought) influences gene expression differently in different genotypes resulting in different levels of "end products": PR(pathogenesis-related) proteins in the mature …

Into The Imagined Forest: A 2000-Year Retrospective Of The German Woods, Richard Hacken

Faculty Publications

In a "House of Learning" lecture in the Harold B. Lee Library in October, 2008, Richard Hacken gave this presentation, a combination of text and images. Coming from the history of ideas, this retrospective of the German woods looked at historical, linguistic, artistic, philosophical, political, literary, cultural, and of course botanical aspects of the German forest. In summary, five major forest themes arise from Germans imagining their own German woods: (1) taming the external and internal wilderness; (2) establishing social justice; (3) advocating national unity; (4) maintaining a sense of the sacred; and (5) encouraging ecological awareness.

Conservation And Conflict Between Endangered Desert Fishes, Jennifer M. Gumm, Jennifer L. Snekser, Murray Itzkowitz

Faculty Publications

Conservation of naturally sympatric endangered species requires unique considerations. While impacts of invasive species garner much attention, interactions between endangered species must also be managed. The endangered Leon Springs pupfish, Cyprinodon bovinus, has suffered a population decline due to decreasing natural habitat. As breeding habitat is lost, C. bovinus is also adversely affected by the sympatric, endangered Pecos gambusia, Gambusia nobilis. Here, we document interactions between these species, finding significantly more G. nobilis accumulated at pupfish spawning events than randomly distributed on breeding grounds in the absence of spawning. As a known egg predator, our results suggest that G. nobilis …