Biology Commons^™

Application Of Shortest-Path Network Analysis To Identify Genes That Modulate Longevity In Saccharomyces Cerevisiae, Jr Managbanag

Theses and Dissertations

Shortest-path network analysis was employed to identify novel genes that modulate longevity in the baker’s yeast Saccharomyces cerevisiae. Based upon a set of previously reported genes associated with increased life span, a shortest path network algorithm was applied to a pre-existing protein-protein interaction dataset in order to construct a shortest-path longevity network. To validate this network, the replicative aging potential of 88 single gene deletion strains corresponding to predicted components of the shortest path longevity network was determined. The 88 single-gene deletion strains identified by a network approach are significantly enriched for mutation conferring both increased and decreased replicative life …

Plumage Ornamentation As An Indicator Of Female Age And An Influence In Male Mate Choice In Protonotaria Citrea, The Prothonotary Warbler In Virginia., Terry Smith

Theses and Dissertations

Flamboyant plumage and ornamentation is common and well-known in male birds; it serves as a sexual display to attract potential mates. While flamboyant plumage is less common and usually more subtle in female birds, it does occur in some species such as Dark-Eyed Juncos (Junco hyemalis) and Prothonotary Warblers (Protonotaria citrea). Prothonotary Warblers display relatively subtle sexual dimorphism. This study examines variations in tail spot patterns in Prothonotary Warblers and relates those variations to age in females. Females with fewer than six spots tend to be two years old or younger; females with six spots or more tend to be …

The Effect Of Nacl On Akinete Differentiation In The Cyanobacterium Nostoc Punctiforme, Jonathan Heekin

Theses and Dissertations

Nostoc punctiforme is a nitrogen-fixing, symbiotic/free-living cyanobacterium. There has been a great deal of research conducted on the genomic nature of N. punctiforme as it pertains to its ecologically important role in the nitrogen cycle in varied environments around the world. My study concentrated on the dormant cell type known as the akinete. Increasing concentrations of NaCl were used to follow the growth phases from germination to akinete formation (lag phase-logarithmic growth phase-stationary phase). I found that increased salt concentrations caused N. punctiforme to form akinetes faster when compared to the control. Germination rates were not greatly increased or shortened …

The Ecology Of Fear: Oviposition And Colonization In Aquatic Systems, Leeanna Pletcher

Theses and Dissertations

Amphibians and aquatic invertebrates have complex life histories that link aquatic and terrestrial food webs. It has been suggested that amphibian reproduction is an important source of carbon to some aquatic systems. This process of energy flow may be shaped by shifts in habitat selection in response to predators. We hypothesized that predators decrease colonization and oviposition of prey, reducing active inputs. Thus predation risk is expected to shift the relative amounts of active and passive subsidies. We manipulated the presence of fish predators in aquatic mesocosms. Results suggest hylid treefrog eggs and hydrophilid beetles were less abundant in predator …

Effects Of Predation Risk, Density And Disease On Energy Efficiency In A Larval Anuran, Sarah Crane

Theses and Dissertations

Predation, density and disease affect behavior, morphology and growth. There is a lack of information on how these changes relate to efficiency of energy transfer in anuran larvae, although previous studies suggest that predation should decrease and competition should increase efficiency. Using a 2 x 2 factorial design, we manipulated predation presence and larval density to test how predation risk and density affect energy efficiency. During the experiment, approximately half of the tadpoles were infected by an unknown disease. Neither predation risk nor density affected assimilation or growth efficiency, despite changes in growth and development. Disease, however, decreased gut length …

The Ecology Of Fear: Colonization And Oviposition In Aquatic Systems [Poster], Leeanna Pletcher, Johanna Kraus, James R. Vonesh

Biology Presentations

Introduction

Amphibians and aquatic invertebrates have complex life histories that link aquatic and terrestrial food webs. It has been suggested that amphibian reproduction is an important source of carbon to some aquatic systems. Movement of organisms across the aquatic-terrestrial habitat boundary can represent important subsidies to the receiving habitat. Subsidies are organisms, nutrients, or detritus that cross habitat boundaries and are consumed, and these allochthonous inputs can affect food web structure. Predators can alter subsidies by consuming organisms that would otherwise move across habitat boundaries. Predator induced shifts in habitat selection are a well known non-lethal effect in aquatic systems. …

Camk-Ii Promotes Beta-Catenin-Dependent Transcription By Binding Flightless-I, Jamie Mcleod

Theses and Dissertations

Transient intracellular elevations of Ca2+ are common signaling mechanisms used to allosterically regulate proteins. One potential target of Ca2+ is Ca2+/calmodulin dependent protein kinase type II (CaMK-II). CaMK-II is a multi-functional protein kinase known to influence cellular pathways such as cell motility and cell cycle progression. Within the cell cycle, CaMK-II promotes the expression of the regulator protein cyclin D1, which is necessary for cell cycle progression. To further understand CaMK-II’s role in cyclin D1 expression, the binding partners of cytosolic CaMK-II were studied using mass spectrometry. Several proteins were identified including β actin, β tubulins, tropomodulin- 3 and Flightless-I. …

Role Of The Small Terminase Subunit Encoded By Staphylococcus Aureus Pathogenicity Island Sapi1 In Formation Of Sapi1 Transducing Particles, Nicholas Paul Olivarez

Theses and Dissertations

Staphylococcus aureus pathogenicity island SaPI1 is a genomic element that is mobilized and transduced at high frequency by helper phage 80α. SaPI1 encodes a small terminase protein that belongs to the phage small terminase subunit family. The presence of SaPI1-encoded small terminase suggests that it plays a role in SaPI1-specific packaging into transducing particles by complexing with the 80α large terminase subunit and redirecting recognition to a pac site on SaPI1 DNA from 80α DNA. The effects of deleting the small terminase genes in SaPI1 and in a prophage copy of 80α are consistent with this hypothesis. Induction of the …

Mechanical Abrasion And Electroporation In The Transformation Of Intact Pleurotus Ostreatus Hyphæ And Nutrient-Dependant Resistance To Hygromycin B, Alexander Cordesman

Theses and Dissertations

ABSTRACT 1: Abrasive treatment and subsequent electroporation of the basidiomycete Pleurotus ostreatus in a hypertonic buffer was investigated as a potential method of transforming of intact hyphæ. Mycelia, which are not capable of being transformed via electroporation due to interference by the cell wall, were abraded in an attempt to mechanically degrade the cell wall prior to electroporation. An electroporation field strength of 12,500 V/cm for 500 μs to 1.25 ms was found to be optimal based upon mortality effects. A 32 μm carborundum abrasive was initially evaluated but was quickly found to be inappropriately large so a corundum abrasive …

Stream Ambient Noise, Spectrum And Propagation Of Sounds In The Goby Padogobius Martensii: Sound Pressure And Particle Velocity, Marco Lugli, Michael L. Fine

Biology Publications

The most sensitive hearing and peak frequencies of courtship calls of the stream goby, Padogobius martensii, fall within a quiet window at around 100Hz in the ambient noise spectrum. Acoustic pressure was previously measured although Padogobius likely responds to particle motion. In this study a combination pressure (p) and particle velocity (u) detector was utilized to describe ambient noise of the habitat, the characteristics of the goby’s sounds and their attenuation with distance. The ambient noise (AN) spectrum is generally similar for p and u (including the quiet window at noisy locations), although the energy distribution of uspectrum is …

The Legacy Of Harvest And Fire On Ecosystem Carbon Storage In A North Temperate Forest, Christopher M. Gough

Biology Publications

Forest harvesting and wildfire were widespread in the upper Great Lakes region of North America during the early 20th century. We examined how long this legacy of disturbance constrains forest carbon (C) storage rates by quantifying C pools and fluxes after harvest and fire in a mixed deciduous forest chronosequence in northern lower Michigan, USA. Study plots ranged in age from 6 to 68 yrs and were created following experimental clear-cut harvesting and fire disturbance. Annual C storage was estimated biometrically from measurements of wood, leaf, fine root, and woody debris mass, mass losses to herbivory, soil carbon content, and …

Corticular Photosynthetic Dynamics For A Coastal Evergreen Shrub: Myrica Cerifera, Jaclyn K. Vick

Theses and Dissertations

I quantified seasonal variations in corticular photosynthesis in 1st through 5th order branches of Myrica cerifera L. (Myricaceae) in order to determine whether corticular photosynthesis contributes to whole plant carbon gain by reducing respirational CO2 loss. Maximum % refixation was 110 ± 39 % of CO2 efflux in the dark (Rd) in 1st order branches during winter, minimum was 18 ± 3 % in 5th order branches during summer. Variations in % refixation paralleled changes in photosynthetically active radiation (PAR). As light attenuated with increasing branch order % refixation decreased. Increased PAR in the winter due to a more sparse …

Spatial And Temporal Patterns Of Anadromous Fish Passage At Boshers Dam Vertical Slot Fishway On The James River, Richmond, Virginia, Matthew Thomas Fisher

Theses and Dissertations

Boshers dam vertical slot fishway, James River, Virginia, U.S.A., opened in 1999 and restored connectivity to 543.3 km of spawning habitat for anadromous fish. The fishway also allowed local movement of resident species. Video observation from 2001-2005 was used to evaluate environmental predictors of American shad (Alosa sapidissima) and sea lamprey (Petromyzon marinus) passage. The ecological effects of restoring connectivity to upstream habitat for gizzard shad (Dorosoma cepedianum) and blue catfish (Ictalurus furcatus) are also discussed. Regression analysis determined that the best predictor of increased daytime American shad passage is higher water temperatures and discharge and for increased daytime sea …

A Comparison Of The Pectoral Spines In Virginia Catfishes, Amanda Dawn Duvall

Theses and Dissertations

Catfish pectoral spines are an anti-predator defense mechanism. They can be bound or locked, making the fish harder to swallow, or used to produce distress calls by rubbing ridges on the dorsal process against a channel in the wall of the pectoral girdle. Growth of the pectoral spine and girdle were examined in relation to fish size within and across species that occur throughout central and eastern Virginia. These included blue catfish (Ictalurus furcatus), channel catfish (Ictalurus punctatus), white catfish (Ameiurus catus), brown bullheads (Ameiurus nebulosus), yellow bullheads (Ameiurus natalis), flathead catfish (Pylodictis olivaris), margined madtom (Noturus insignis), and tadpole …

Interleukin-10 Suppresses Mast Cell Ige Receptor Expression And Signaling In Vitro And In Vivo, Sarah B. Kennedy

Theses and Dissertations

Background: Mast cells are known for their role in allergy, asthma, and systemic anaphylaxis, and have been shown to play a role in inflammatory disease. Interleukin-10 can regulate inflammatory responses both in vitro and in vivo, and may be a natural regulator of mast cell activation.Objective: To examine Interleukin-10 mediated regulation of FcεRI expression and related downstream signaling molecules, and to determine how this affects mast cell function in vitro and in vivo.Methods: Mast cell FcεRI expression was evaluated with and without IL-10 treatment in human lung and skin mast cells, and on peritoneal mast cells from mice overexpressing IL-10 …

Degenerate Oligonucleotide Primed - Polymerase Chain Reaction Evaluation And Optimization To Improve Downstream Forensic Str Analysis Of Low Quality/Low Quantity Dna, Lindsay Paige Thompson

Theses and Dissertations

When forensic biological samples yield low quality/low quantity DNA, thecurrent STR analysis methods do not generate acceptable profiles. Whole genomeamplification can be used to pre-amplify the entire genome for downstream analyses. A commercially available kit for DOP-PCR, a form of WGA, is currently being used in the clinical for downstream single locus targets. Forensic analyses utilize a multiplex amplification. This study determined that the "home brew" created by our lab performs the same as the commercially available kit. Future optimization studies of DOP-PCR can utilize this "home brew". Additionally, this research determined that a 10 second increase in electrokinetic injection …

Acquisition And Retention Of Bacterial Spores (Bacillus Atrophaeus) By Eight Insect Species, Kieron Marie Torres

Theses and Dissertations

Acquisition and retention of spores of an anthrax surrogate, Bacillus atrophaeus Nakamura ("BG") were evaluated in eight insect species. Species included: house cricket (Acheta domesticus L.), German cockroach (Blatella germanica L.), common house fly (Musca domestics L.), blue bottle fly (Calliphora vomitoria L.), hairy rove beetle Creophilus maxillosus L.), yellow mealworm (Tenebrio molitor L.), common paper wasps (Polistes exclamans exclamans Viereck), red paper wasps (Polistes Carolina L.), red harvester ant (Pogonymyrmex barbatus Smith). Individual insects were offered BG-treated food and sacrificed at specified time intervals following one, two or three meals. Resulting samples were surface-washed five consecutive times then homogenized …

Genetic Assessment Of Rare Blackbanded Sunfish (Enneacanthus Chaetodon) Populations In Virginia, Diana Marie Kercher

Theses and Dissertations

Enneacanthus chaetodon, the blackbanded sunfish, has become increasingly rare throughout its distribution in the Eastern United States. In Virginia, E. chaetodon maintains an endangered status and individuals persist in six populations. Mitochondrial DNA (mtDNA) and microsatellite data were assessed to determine the genetic characters and gene diversity of the Virginia populations. The results of these analyses were then compared to five additional populations; four from New Jersey and one from North Carolina that were known to have relatively good fitness and were not impacted severely by habitat alteration. The results of this study are relevant to selection of proper management …

Invasion Genetics Of The Blue Catfish (Ictalurus Furcatus) Range Expansion Into Large River Ecosystems Of The Chesapeake Bay Watershed, Colleen Beth Higgins

Theses and Dissertations

The blue catfish, Ictalurus furcatus (Ictaluridae), is ranked among the most invasive, nonnative species of concern in the Chesapeake Bay watershed. This species, intentionally introduced to three major tributaries and a number of impoundments between 1974 and 1989 for sport fishing, has spread into three additional tributaries. Using samples from the introduced tributary populations as a baseline, we evaluated microsatellite genetic variation in light of demographic and ecological data to elucidate the potential sources of the invasive I. furcatus populations. In general, the populations surveyed in the Chesapeake Bay watershed were considerably more inbred (F ranged from 0.03 - 0.27) …

Calcium/Calmodulin Dependent Protein Kinase Type-Ii Associates With Flightless-I To Influence Its Nuclear Localization, Matthew Edward Seward

Theses and Dissertations

Ca2+/calmodulin-dependent protein kinase type-II (CaMK-II) is a Ser/Thr protein kinase regulated by Ca2+ and Calmodulin. It is a highly conserved and broadly expressed enzyme and has a unique structure and dynamic regulation. It has the ability to remain active in the absence of Ca 2+ as a result of Ca2+ dependent autophosphorylation. CaMK-II phospliorylates proteins involved in neurotransmitter secretion, long term potentiation, cytoskeletal dynamics, gene transcription, and cell motility. To support existing and identify new intracellular roles of CaMK-II, potential binding partners were identified. This was accomplished by transfecting and purifying "FLAG-tagged" CaMK-II's (α, βE, δC, and δE). CaMK-II associated …

Degenerate Oligonucleotide Primed-Pcr: Thermalcycling Modifications And Comparison Studies, Denise N. Rodier

Theses and Dissertations

Degenerate Oligonucleotide Primed-PCR (DOP-PCR) can potentially enhance analysis of low copy number DNA samples. Theoretically, this procedure replicates fragments of the genome that can then be used for downstream multiplex STR analysis. The objective of this study is to optimize DOP-PCR by examining ramplelongation times and cycle numbers in the non-specific amplification portion of DOP-PCR, and by modifying the degenerate primer. Additionally, other methods such as Multiple Displacement Amplification (MDA) and Low Copy Number PCR (LCN PCR) were examined for their ability to create accurate DNA profiles from low DNA input amounts. Increasing the ramplelongation times showed no effect on …

Transforming Growth Factor-Β1 (Tgf-Β1) Induces Mast Cell Apoptosis, Farnaz Norozian

Theses and Dissertations

Mast cells are potent effectors of the inflammatory response, playing an important role in atopy, bacterial immunity, and animal models of arthritis, multiple sclerosis, and heart disease. Hence controlling mast cell numbers and responsiveness is essential for preventing inflammatory disease. This work demonstrated that the cytokine TGF-β1 is a potent inducer of mast cell apoptosis, a finding that was consistent for cultured mouse bone marrow-derived mast cells, peritoneal mast cells, and human mast cells. Cell death appeared to be the result of TGF-mediated repression of IL-3 receptor expression and function, leading to mitochondria1 damage and activation of an apoptotic cascade …

Autocrine Effects Of Catecholamines On Macrophage Release Of Interleukin-6 (Il-6), Shaunta D. Poe

Theses and Dissertations

Effects of norepinephrine (NE) on macrophage cytokine release are complex because the cells have both α2 and β2 adrenergic receptors, which mediate opposing actions. Furthermore, β2-adrenergic agonists are reported to have both stimulatory and inhibitory effects on interleukin-6 (IL-6). This study was designed to clarify the autocrine role of macrophage-derived NE on IL-6 production in activated peritoneal macrophages. Effects of NE on IL-6 production in the RAW264.7 macrophage cell-line also were investigated. Treatment of activated peritoneal macrophages with endotoxin, the α2-adrenergic antagonists yohimbine or RS79948 revealed that the α2-adrenergic receptor mediates a stimulatory autocrine action of catecholamines on IL-6 production. …

Modulation Of The Serotonin Reuptake Transporter In Raw264.7 Macrophages, Sienna Marie Arenas Malubay

Theses and Dissertations

Serotonin (5-HT) plays an important role as both a neurotransmitter and animmune modulator. The serotonin reuptake transporter (SERT) clears the extracellular space of 5-HT, which decreases the effects of 5-HT on target cells. This study demonstrated that the RAW264.7 macrophage cell line expresses SERT function, measured by assays of 3H-5HT uptake. The 5-HT uptake in RAW264.7 macrophages was more than 10-fold that of peritoneal macrophages, indicating that these cells are an excellent model for studying regulation of the SERT. Activation of macrophages with lipopolysaccharide (LPS) increased SERT activity in a time- and concentration-dependent manner and Western blots indicate that the …

Genetic Variation Among Geographically Disparate Yellow Perch Broodstock Populations, Chandler Brooke Givens

Theses and Dissertations

As a prelude to strain selection for domestication and future marker assisted selection, genetic variation revealed by microsatellite DNA was evaluated in yellow perch, Perca flavescens, from four wild North American populations collected in 2003-2004 (Maine, ME; New York, NY; North Carolina, NC; and Pennsylvania, PA), and two captive populations (Michigan, MI; Ohio, OH). For the loci examined, levels of heterozygosity ranged from He = 0.04 to 0.88, genetic differentiation was highly significant among all population pairs, and effective migration ranged from low (Nem = 0.3) to high (Nem = 4.5). Deviation from Hardy-Weinberg 1equilibrium was regularly observed indicating significant …

Novel Characteristics Of Murine Bone Marrow-Derived Macrophages And Human Macrophage-Like Cells, George Tharwat Georges

Theses and Dissertations

These studies provide evidence for novel properties of macrophages derived from bone marrow stem cells. In study 1, treatment of activated mouse bone marrow-derived macrophages (BMM) with either catecholamine synthesis inhibitors (α-methyl-para-tyrosine and fusaric acid) or the β2 adrenergic receptor antagonist ICI 118,551 demonstrated that BMM produce catecholamines. The catecholamines modulated macrophage cytokine production through autocrine actions on adrenergic receptors. In study II, undifferentiated human bone marrow cells were incubated in 30% mouse L929 fibroblast conditioned medium and generated adherent cells within three days. The cells were clearly identifiable as macrophages based on surface proteins and phagocytic activity but produced …

Phylogeography Of Marine Meiofaunal Nemerteans Of The Ototyphlonemertes Fila Species Complex, Alexander Tulchinsky

Theses and Dissertations

Morphological conservatism combined with intraspecific variability has obstructed studies of speciation and species boundaries among marine meiofauna. Ototyphlonemertes is a genus of meiofaunal nemerteans inhabiting the interstitial spaces of marine sediments. Its members lack pelagic larvae and dispersal potential is believed to be poor. A phylogeographic study of Ototyphlonemertes fila is presented using mitochondrial (cox3) and nuclear (ISSR) molecular markers. Deep genetic divergence (approximately 18% in cox3) was observed between sympatric mitochondrial lineages in Florida. This divergence was reflected in the nuclear marker as well, suggesting the presence of two cryptic species. The first contains Florida and New England populations …

A Multiple-Objective Decision Analysis Of Stakeholder Values To Identify Watershed Improvement Needs, Jason R. W. Merrick, Gregory S. Parnell, Jamison Barnett, Margot Garcia

Statistical Sciences and Operations Research Publications

The paper describes the use of multiple objective decision analysis to qualitatively and quantitatively assess the quality of an endangered watershed and guide future efforts to improve the quality of the watershed. The Upham Brook watershed is an urban watershed that lies at the interface of declining inner city Richmond, Virginia and growth-oriented Henrico County. A section of stream within the watershed has been identified as so dangerously polluted that it threatens the health of the residents who live within the watershed boundaries. With funding provided by the National Science Foundation, the Upham Brook watershed project committee was formed to …

Genetic Variability, Pathogen Susceptibility, Subspecies Identity And Conservation Of The Endangered Northern Flying Squirrel (Glaucomys Sabrinus) In Virginia, James Lincoln Sparks Jr.

Theses and Dissertations

I examined the population genetic structure of three known subspecies of Glaucomys sabrinus from Appalachia, Washington State, and two previously unexamined populations from Mount Rogers National Recreation Area (MRNRA) in Southwestern Virginia. Mean FST (0.107) and an AMOVA (P G. sabrinus subspecies populations in the southern Appalachians are genetically differentiated. Glaucomys sabrinus at MRNRA were less inbred than expected. Gene flow, a consensus tree based on Nei's genetic distance, elevated heterozygosity and morphometric data suggest that the MRNRA G. sabrinus population is an intergrade of the two recognized Appalachian subspecies, G. s. fuscus and G. s. coloratus. I compared inbreeding …

Material And Acoustic Properties Of Swimbladders Of Tilapia And Channel Catfish, Mohammed Ali Nawaz

Theses and Dissertations

Acoustically, teleost swimbladders have been considered resonant underwater bubbles. Contrary results indicating that bladders are tuned less sharply than such a bubble have been explained by damping of surrounding fish tissue. Recent findings in toadfish and weakfish, however, suggest that the bladder is a highly damped structure and that the frequency of the fish sounds is deternlined as a forced response to sonic muscle movement rather than by resonance of the bladder. In this study I examined acoustics and material properties of swimbladders in Tilapia (an auditory generalist) and the channel catfish (an auditory specialist). The swimbladder was struck with …