Digital Commons Network^™

Tracking Changes In Bioavailable Fe Within High-Nitrate Low-Chlorophyll Oceanic Waters: A First Estimate Using A Heterotrophic Bacterial Bioreporter, Robert Michael Mckay, C. E. Mioni, S. M. Handy, M. J. Ellwood, M. R. Twiss, P. W. Boyd, S. W. Wilhelm

Biological Sciences Faculty Publications

It is conventional knowledge that heterotrophic bacteria play a key role in the biogeochemical cycling of oceanic carbon. However, only recently has their role in marine iron ( Fe) biogeochemical cycles been examined. Research during this past decade has demonstrated an inextricable link between Fe chemistry and the biota, as >99% of Fe in marine systems is complexed to organic chelates of unknown but obviously biotic origin. Here we present a novel approach to assess and compare Fe bioavailability in low Fe HNLC waters using a bioluminescent bacterial reporter that quantitatively responds to the concentration of bioavailable Fe by producing …

Impact Of Phytoplankton On The Biogeochemical Cycling Of Iron In Subantarctic Waters Southeast Of New Zealand During Fecycle, Robert Michael Mckay, S. W. Wilhelm, J. Hall, D. A. Hutchins, M. M. D. Al-R Shaidat, C. E. Mioni, S. Pickmere, D. Porta, P. W. Boyd

Biological Sciences Faculty Publications

During austral summer 2003, we tracked a patch of surface water infused with the tracer sulfur hexafluoride, but without addition of Fe, through subantarctic waters over 10 days in order to characterize and quantify algal Fe pools and fluxes to construct a detailed biogeochemical budget. Nutrient profiles characterized this patch as a high-nitrate, low-silicic acid, low-chlorophyll (HNLSiLC) water mass deficient in dissolved Fe. The low Fe condition was confirmed by several approaches: shipboard iron enrichment experiments and physiological indices of Fe deficiency (F(v)/F(m) < 0.25, Ferredoxin Index < 0.2). During FeCycle, picophytoplankton (0.2-2 mu m) and nanophytoplankton (2-20 mu m) each contributed >40% of total chlorophyll. Whereas the picophytoplankton accounted for similar to 50% of total primary production, they …

Ranging Patterns And Habitat Utilization Of Northern River Otters, Lontra Canadensis, In Missouri: Implications For The Conservation Of A Reintroduced Species, Deborah Dorothy Boege-Tobin

Dissertations

I studied the spacing patterns and habitat utilization by reintroduced northern river otters, Lontra canadensis, at two sites in Missouri because previous studies of otters indicate, plasticity of a species social structure will likely be due to the tactics employed in acquiring resources in any given area. Seven hypotheses were tested by employing radio-tracking, habitat assessment and geographic information system approaches: (1) home range (HR) and core area (CA) size differ by sex; (2) HR and CA size differ in breeding vs. non-breeding seasons; (3) percent range overlap differs by sex; (4) habitat utilization, as indicated by latrine use, …

The Use Of Antibiotic Resistance Profiles To Access The Source Of Fecal Contamination In The Rowan County, Kentucky Watershed, Logan Harrison Burns

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Logan Harrison Burns on December 15, 2005.

The Relationship Between Frq-Protein Stability And Temperature Compensation In The Neurospora Circadian Clock, Peter Ruoff, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

Temperature compensation is an important property of all biological clocks. In Neurospora crassa, negative-feedback regulation on the frequency (frq) gene's transcription by the FRQ protein plays a central role in the organism's circadian pacemaker. Earlier model calculations predicted that the stability of FRQ should determine the period length of Neurospora's circadian rhythm as well as the rhythm's temperature compensation. Here, we report experimental FRQ protein stabilities in frq mutants at 20 degrees C and 25 degrees C, and estimates of overall activation energies for mutant FRQ protein degradation. The results are consistent with earlier model predictions, i.e., temperature compensation of …

Exposure To Methamphetamine And Phencyclidine During Development And Subsequent Behavioral Change, Takehiro Minamoto

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Takehiro Minamoto on December 2, 2005.

Modeling The Acquisition Of Social Rank In Crayfish: Winner And Loser Effects And Self-Structuring Properties, Karlo Hock, Robert Huber

Robert Huber

No abstract provided.

Sal-Site: Integrating New And Existing Ambystomatid Salamander Research And Informational Resources, Jeramiah J. Smith, Srikrishna Putta, John A. Walker, D. Kevin Kump, Amy K. Samuels, James R. Monaghan, David W. Weisrock, Chuck Staben, S. Randal Voss

Biology Faculty Publications

Salamanders of the genus Ambystoma are a unique model organism system because they enable natural history and biomedical research in the laboratory or field. We developed Sal-Site to integrate new and existing ambystomatid salamander research resources in support of this model system. Sal-Site hosts six important resources: 1) Salamander Genome Project: an information-based web-site describing progress in genome resource development, 2) Ambystoma EST Database: a database of manually edited and analyzed contigs assembled from ESTs that were collected from A. tigrinum tigrinum and A. mexicanum, 3) Ambystoma Gene Collection: a database containing full-length protein-coding sequences, 4) Ambystoma Map and Marker …

Select Listeria Monocytogenes Subtypes Commonly Found In Foods Carry Distinct Nonsense Mutations In Inla, Leading To Expression Of Truncated And Secreted Internalin A, And Are Associated With A Reduced Invasion Phenotype For Human Intestinal Epithelial Cells, K. K. Nightingale, K. Windham, K. E. Martin, M. Yeung, M. Wiedmann

Biological Sciences

The surface protein internalin A (InlA) contributes to the invasion of human intestinal epithelial cells by Listeria monocytogenes. Screening of L. monocytogenes strains isolated from human clinical cases (n=46), foods (n=118), and healthy animals (n=58) in the United States revealed mutations in inlA leading to premature stop codons (PMSCs) in L. monocytogenes ribotypes DUP-1052A and DUP-16635A (PMSC mutation type 1), DUP-1025A and DUP-1031A (PMSC mutation type 2), and DUP-1046B and DUP-1062A (PMSC mutation type 3). While all DUP-1046B, DUP-1062A, DUP-16635A, and DUP-1031A isolates (n=76) contained inlA PMSCs, ribotypes DUP-1052A and DUP-1025A ( …

Limits Of Temperature Tolerance Of Leishmania Enriettii And Leishmania Hertigi In A Real-Time Pcr Assay, Christina Salinas

Theses & Dissertations

Protozoans of the genus Leishmania are intracellular parasites found across five continents. They cycle between a promastigote form inside the digestive tracts of blood-feeding female sand flies and an amastigote form within mammalian host macrophages. Temperature is an important factor that must be defeated in order for the parasites' survival and continuance. This paper studies the limits of temperature tolerance by Leishmania enriettii and Leishmania hertigi. It was hypothesized that a correlation would exist between the limits of temperature tolerance to body temperature of their host. I explored growth characteristics at 21,27,29, 33, 35, 37, and 39° C. It was …

Bartonella Bacilliformis Groel: Effect On Growth Of Human Vascular Endothelial Cells In Infected Cocultures, Laura S. Smitherman, Michael F. Minnick

Biological Sciences Faculty Publications

Bartonella are the only bacteria known to induce angioproliferative lesions of the human vasculature and liver during infection. Previous work from our lab suggests that GroEL participates in the mitogenic response observed in HUVEC cultures supplemented with the soluble fraction of Bartonella bacilliformis. Work in this study shows that exposure to high concentrations of the fraction is actually cytotoxic for HUVECs. To analyze this phenomenon, live B. bacilliformis-HUVEC cocultures were employed to study the effect of excess bacterial GroEL on the host cell during active infection. Four B. bacilliformis strains were generated to produce varying levels of GroEL. HUVEC cocultures …

Requiring Undergraduate Research For A Bs Degree In Biology: Does It Do Any Good?, Heather G. Kuruvilla, Alicia E. Schaffner, B. E. Phipps

Science and Mathematics Faculty Presentations

Cedarville University is a primarily undergraduate institution located in Southwest Ohio. Cedarville has always been committed to excellence in teaching, and our focus is on mentoring undergraduate students in order to ensure their future success. However, we realize that the research experience is a critical part of “learning science”.

Several years ago, the biology faculty at Cedarville University decided to make a one-semester course in undergraduate research a mandatory component of the BS degree in biology. Research remains a popular elective choice for the BA degree in biology, as well as the biology education degree.

Our aim in requiring research …

[Accepted Article Manuscript Version (Postprint)] Identification And Functional Characterization Of Arabidopsis Peroxin4 And The Interacting Protein Peroxin22, Bethany Zolman, Melanie Monroe-Augustus, Illeana Silva, Bonnie Bartel

Biology Department Faculty Works

Peroxins are genetically defined as proteins necessary for peroxisome biogenesis. By screening for reduced response to indole-3-butyric acid, which is metabolized to active auxin in peroxisomes, we isolated an Arabidopsis thaliana peroxin4 (pex4) mutant. This mutant displays sucrose-dependent seedling development and reduced lateral root production, characteristics of plant peroxisome malfunction. We used yeast two-hybrid analysis to determine that PEX4, an apparent ubiquitinconjugating enzyme, interacts with a previously unidentified Arabidopsis protein, PEX22. A pex4 pex22 double mutant enhanced pex4 defects, confirming that PEX22 is a peroxin. Expression of both Arabidopsis genes together complemented yeast pex4 or pex22 mutant defects, whereas expression …

A Ciliary Sensation: Mapping Components Of The Gtp Signaling Pathway, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

GTP is a chemorepellent in Tetrahymena thermophila, causing cells to exhibit avoidance behavior, characterized by ciliary reversal. Recent work in our laboratory has shown that tyrosine kinase activity is required in order for GTP signaling to take place (Bartholomew et al., submitted for publication). Second messengers which we have found to be important for GTP signaling in Tetrahymena include nitric oxide and cGMP. Previous studies by Kim et al., 1999, have shown that a calcium-based depolarization is elicited by the application of extracellular GTP. Currently, our lab is addressing the question of where intracellular calcium is involved in the GTP …

Avian Hosts For West Nile Virus In St. Tammany Parish, Louisiana, 2002, Nicholas Komar, Nicholas A. Panella, Stanley A. Langevin, Aaron C. Brault, Manuel Amador, Eric Edwards, Jennifer C. Owen

Faculty Publications

West Nile virus (WNV) infections in free-ranging birds were studied in Slidell, St. Tammany Parish, Louisiana, after a human encephalitis outbreak peaked there in July 2002. Seroprevalence in resident, free-ranging wild birds in one suburban site was 25% and 24% in August and October, respectively, indicating that most transmission had ceased by early August. Mortality rates, seroprevalence rates, host competence, and crude population estimates were used in mathematical models to predict actual infection rates, population impacts, and importance as amplifying hosts for several common passerine birds. Northern cardinal (Cardinalis cardinalis) and house sparrow (Passer domesticus) were the principal amplifying hosts, …

Disentangling Above‐ And Below‐Ground Competition Between Lianas And Trees In A Tropical Forest, Stefan A. Schnitzer, Mirjam E. Kuzee, Frans Bongers

Biological Sciences Faculty Research and Publications

1. Light is thought to be the most limiting resource in tropical forests, and thus above‐ground competition is commonly accepted as the mechanism that structures these communities. In many tropical forests, trees compete not only with other trees, but also with lianas, which compete aggressively for below‐ground resources and thus may limit tree growth and regeneration.
2. Using a replicated experiment, we tested the relative strengths of above‐ and below‐ground competition from lianas on tree saplings in a disturbed forest in Côte d’Ivoire with a heterogeneous canopy and relatively high light penetration. We planted seedlings of three tree species and subjected them …

Climatic Unpredictability And Parasitism Of Caterpillars: Implications Of Global Warming, John Stireman, Lee Dyer, D. Janzen, M. Singer, J. Lill, R. Marquis, R. Ricklefs, G. Gentry, W. Hallwachs, P. Coley, J. Barone, H. Greeney, H. Connahs, P. Barbosa, H. Morais, I. Diniz

Biology Department Faculty Works

Insect outbreaks are expected to increase in frequency and intensity with projected changes in global climate through direct effects of climate change on insect populations and through disruption of community interactions. Although there is much concern about mean changes in global climate, the impact of climatic variability itself on species interactions has been little explored. Here, we compare caterpillar–parasitoid interactions across a broad gradient of climatic variability and find that the combined data in 15 geographically dispersed databases show a decrease in levels of parasitism as climatic variability increases. The dominant contribution to this pattern by relatively specialized parasitoid wasps …

Climatic Unpredictability And Parasitism Of Caterpillars: Implications Of Global Warming, John O. Stireman Iii, Lee A. Dyer, D. H. Janzen, M. S. Singer, J. T. Lill, R. J. Marquis, R. E. Ricklefs, G. L. Gentry, W. Hallwachs, P. D. Coley, J. A. Barone, H. F. Greeney, H. Connahs, P. Barbosa, H. C. Morais, I. R. Diniz

Robert Marquis

Applications Of Phylogenetics To Issues In Freshwater Crayfish Biology, Keith A. Crandall

Faculty Publications

Freshwater crayfish have served as model organisms for over 125 years in scientific research, from areas such as neurobiology and vision research to conservation biology and evolution. Recently, evolutionary histories in the form of phylogenies have served as a critical foundation for testing hypotheses in such diverse research areas as well. In this article, I review the amazing diversity of freshwater crayfish, especially in a phylogenetic context and explore how these evolutionary histories have informed crayfish biology and can be used powerfully in the future to guide research in a diversity of areas. Throughout the article, I draw on examples …

Dynamics Of Canopy Cover In A Wet Forest In Costa Rica, Carolina Brinez

FIU Electronic Theses and Dissertations

I examined the effects of soil and slope conditions on canopy dynamics in terms of openness and leaf area index through time as measured by hemispherical photography. Specifically, I compared alluvial versus residual soil and slope versus plateau and flat plots in an old-growth tropical wet forest in Costa Rica. No significant effects of slope were found for any estimator of canopy coverage in any analysis. Soil type approached significance as a single factor and several soil*year interactions were highly significant. In addition, I found highly significant inter-annual variation in all analyses that was concordant on all plot types. This …

Hybridization Of Lythrurus Fasciolaris (Cope) And Lythrurus Umbratilis (Girard) (Cypriniformes: Cyprinidae) In The Ohio River Basin, Robert L. Hopkins Ii

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Robert L. Hopkins, II on November 14, 2005.

The Three Dimensional Detection Of Microvasculatory Bed In The Brain Of White Rat Rattus Norvegicus By A Ca2+ -Atpase Method., Amaiak Chilingaryan, Amayak Chilingaryan, Gary Martin

Gary Martin

A procedure is described which allows for the selective and non-injectional staining of the three-dimensional microvasculatory bed (MVB) in thick sections (60–140 μm) of formalin-fixed brain tissue of white rats Rattus norvegicus. This histochemical method detects ATPase activity and takes place between pH 10.5 and 11.2. Calcium ion is used to capture inorganic phosphate, calcium phosphate is converted to lead phosphate, and subsequently converted to black or dark brown lead sulfide. All vessels are revealed due to a precipitate on the endothelium and smooth muscle cells of arterioles. In some vessels, red blood cells also stain. The background is transparent …

Ego-1, A Putative Rna-Dependent Rna Polymerase, Is Required For Heterochromatin Assembly On Unpaired Dna During C. Elegans Meiosis, Eleanor M. Maine, Jessica Hauth, Thomas Ratliff, Valarie E. Vought, Xingyu She, William G. Kelly

Biology - All Scholarship

During meiosis in C. elegans, unpaired chromosomes and chromosomal regions accumulate high levels of histone H3 lysine 9 dimethylation (H3K9me2), a modification associated with facultative heterochromatin assembly and the resulting transcriptional silencing [1, 2]. Meiotic silencing of unpaired DNA may be a widely conserved genome defense mechanism [3–5]. The mechanisms of meiotic silencing remain unclear, although both transcriptional and posttranscriptional processes are implicated [3–5]. Cellular RNA-dependent RNA polymerases (RdRPs) function in development and RNA-mediated silencing in many species [3, 6, 7] and in heterochromatin assembly in S. pombe [3, 8]. There are four C. elegans RdRPs, including two with known …

Rapid Senescence In Pacific Salmon, Yolanda E. Morbey, Chad Brassil, Andrew P. Hendry

School of Biological Sciences: Faculty Publications

Any useful evolutionary theory of senescence must be able to explain variation within and among natural populations and species. This requires a careful characterization of age-specific mortality rates in nature as well as the intrinsic and extrinsic factors that influence these rates. We perform this task for two populations of semelparous Pacific salmon. During the breeding season, estimated daily mortality rates increased from 0 to 0.2–0.5 (depending on the year) over the course of several weeks. Early-arriving individuals had a later onset and/or a lower rate of senescence in each breeding season, consistent with adaptive expectations based on temporal variation …

Plumage Convergence In Picoides Woodpeckers Based On A Molecular Phylogeny, With Emphasis On Convergence In Downy And Hairy Woodpeckers, Amy C. Weibel, William S. Moore

Biological Sciences Faculty Research Publications

Adult and juvenile plumage characters were traced onto a well-resolved molecular based phylogeny for Picoides woodpeckers, and a simple phylogenetic test of homology, parallelism, and convergence of plumage characters was performed. Reconstruction of ancestral character states revealed multiple events of independent evolution of derived character states in most characters studied, and a concentrated changes test revealed that some plumage characters evolved in association with habitat type. For example, there was a statistically significant association between loss of dorsal barring and use of densely vegetated habitats among Picoides species. Two analyses indicated that convergence, as opposed to parallel evolution or shared …

Empirical Analysis Of The Str Profiles Resulting From Conceptual Mixtures, David R. Paoletti, Travis E. Doom, Carissa M. Krane, Michael L. Raymer, Dan E. Krane

Biology Faculty Publications

Samples containing DNA from two or more individuals can be difficult to interpret. Even ascertaining the number of contributors can be challenging and associated uncertainties can have dramatic effects on the interpretation of testing results. Using an FBI genotypes dataset, containing complete genotype information from the 13 Combined DNA Index System (CODIS) loci for 959 individuals, all possible mixtures of three individuals were exhaustively and empirically computed. Allele sharing between pairs of individuals in the original dataset, a randomized dataset and datasets of generated cousins and siblings was evaluated as were the number of loci that were necessary to reliably …

The Role Of Cuticular Pheromones In Courtship Conditioning Of Drosophila Males, Kathleen King Siwicki, Paul Nicholas Riccio , '05, Lisa Ladewski , '02, F. Marcillac, L. Dartevelle, Stephanie Alexis Cross , '04, J.-F. Ferveur

Biology Faculty Works

Courtship conditioning is an associative learning paradigm in Drosophila melanogaster, wherein male courtship behavior is modified by experience with unreceptive, previously mated females. While the training experience with mated females involves multiple sensory and behavioral interactions, we hypothesized that female cuticular hydrocarbons function as a specific chemosensory conditioned stimulus in this learning paradigm. The effects of training with mated females were determined in courtship tests with either wild-type virgin females as courtship targets, or with target flies of different genotypes that express distinct Cuticular hydrocarbon (CH) profiles. Results of tests with female targets that lacked the normal CH profile, and …

Flexible Social Structure Of A Desert Rodent, Rhombomys Opimus: Philopatry, Kinship, And Ecological Constraints, Jan Randall, Konstantin Rogovin, Patricia Parker, John Eimes

Biology Department Faculty Works

We tested hypotheses based on philopatry, kinship, and ecological constraints to explain sociality in a semifossorial desert rodent, the great gerbil, Rhombomys opimus. Data were collected in the field in Uzbekistan in the spring and fall of 1996 and 1998–2004. Population densities fluctuated dramatically with high turnover in both males and females to reveal that dispersal and social structure were density dependent. Fewer gerbils dispersed at higher densities and members of family groups dispersed together. A majority of females lived in groups at high densities, but as population densities declined, proportionally more females were solitary. DNA analysis revealed that group-living …

Bateman Gradients In Field And Laboratory Studies: A Cautionary Tale, Patricia Parker, Zuleyma Tang-Martinez

Biology Department Faculty Works

Since tools of molecular genetics became readily available, our understanding of bird mating systems has undergone a revolution. The majority of passerine species investigated are socially monogamous, but have been shown to be genetically polygamous. Data sets from natural populations of juncos suggest that multiple mating by females results in a sexual selection gradient as steep for females as for males (a result that does not support Bateman's predictions). However, in males, fitness is enhanced directly through fertilization success with multiple matings; in females fitness benefits may be enhanced immediately through direct access to food, protection against predators, or other …

Contributions Of Heterosis And Epistasis To Hybrid Fitness, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Early-generation hybrid fitness is difficult to interpret because heterosis can obscure the effects of hybrid breakdown. We used controlled reciprocal crosses and common garden experiments to distinguish between effects of heterosis and nuclear and cytonuclear epistasis among morphotypes and advanced-generation hybrid derivative populations in the Piriqueta caroliniana (Turneraceae) plant complex. Seed germination, growth, and sexual reproduction of first-generation hybrids, inbred parental lines, and outbred parental lines were compared under field conditions. Average vegetative performance was greater for hybrids than for inbred lines, and firstseason growth was similar for hybrids and outbred parental lines. Hybrid survival surpassed that of inbred lines …