Biology Commons^™

Consequences Of Life History Switch Point Plasticity For Juvenile Morphology And Locomotion In The Túngara Frog, Julie Charbonnier, James R. Vonesh

Biology Publications

Many animals with complex life cycles can cope with environmental uncertainty by altering the timing of life history switch points through plasticity. Pond hydroperiod has important consequences for the fitness of aquatic organisms and many taxa alter the timing of life history switch points in response to habitat desiccation. For example, larval amphibians can metamorphose early to escape drying ponds. Such plasticity may induce variation in size and morphology of juveniles which can result in carry-over effects on jumping performance. To investigate the carry-over effects of metamorphic plasticity to pond drying, we studied the Túngara frog,Physalaemus pustulosus, a …

Using The Past To Restore The Future: Quantifying Historical Vegetation To Assist In Tidal Freshwater Wetland Restoration, Christopher D. Gatens

UROP Posters

Wetlands have been providing humans with critical natural ecosystem services throughout our time on Earth. Nevertheless, these invaluable ecosystems have been habitually altered as a cost of human progression. Two of the most common alterations to wetlands are damming and filling. Both occurred along Kimages Creek in Charles City County, VA during the 19^th and 20^th centuries. In 2010 the Lake Charles dam was partially removed, restoring the creek’s tidal communication with the James River. Upon the recession of the body of water, numerous woody stumps were revealed. We studied these stump remnants in an attempt to assess …

Hannah Huddle: Visually Comparing Art And Science, Mark Hardison

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

Hannah Huddle, a junior at VCU majoring in communications arts with a concentration in scientific illustration, has been working on a research project with VCU biology professor Dr. Lesley Bulluck, and a group of six students, researching the Prothonotary Warbler. Unlike most researchers, Huddle is both studying the biology of the bird and making illustrations of the bird and the research involving the Warbler.

Effects Of Tgf-Β1 And Il-33 On Mast Cell Function, Victor S. Ndaw

Theses and Dissertations

TGFβ is involved in many pathological conditions, including autoimmune disorders, cancer, and cardiovascular and allergic diseases. We have previously found that TGFβ can suppress IgE-mediated mast cell activation in human and mouse mast cells in vitro. IL-33 is a recently discovered member of the IL-1 family capable of inducing mast cell responses and enhancing IgE-mediated activation. In this study, we investigated the effects of TGFβ on IL-33-mediated mast cell activation. Bone marrow-derived mast cells cultured in TGFβ -1, -2, or -3 showed reduced IL-33-mediated production of TNF, IL-6, IL-13 and MCP-1, in a concentration-dependent manner. Furthermore, TGFβ also reduced …

Prothonotary Warbler Nestling Diet And Growth In Response To Variation In Aquatic And Terrestrial Food Availability, Jenna C. Dodson

Theses and Dissertations

Food supply has been suggested as the main determinant of reproductive success in birds. Riparian species can take advantage of seasonal pulses of both terrestrial and aquatic prey, though aquatic resources are often overlooked in studies of diet and reproductive ecology. This study investigates the flux of both aquatic (mayfly) and terrestrial (caterpillar) prey resources and nestling diet of the Prothonotary Warbler throughout the breeding season in two eastern Virginia sites. One site had significantly higher aquatic prey (mayfly) availability. Nestling diet was generally reflective of prey availability, and nestlings grew faster at the site with high aquatic prey availability. …

Mysteries Of The Trypanosomatid Maxicircles: Characterization Of The Maxicircle Genomes And The Evolution Of Rna Editing In The Order Kinetoplastida, Preethi Ranganathan Iyengar

Theses and Dissertations

The trypanosomatid protists belonging to Order Kinetoplastida are some of the most successful parasites ever known to mankind. Their extreme physiological diversity and adaptability to different environmental conditions and host systems make them some of the most widespread parasites, causing deadly diseases in humans and other vertebrates.

This project focuses on their unique mitochondrion, called the kinetoplast, and more specifically involves the characterization of a part of their mitochondrial DNA (also called kinetoplast DNA or kDNA), the maxicircles, which are functional homologs of eukaryotic mitochondrial DNA in the kinetoplastid protists. We have sequenced and characterized the maxicircle genomes of 20 …

An Evaluation Of The Differential Stability Of Nucleic Acids In Biological Fluids Compromised By Degradative Treatments And Environmental Exposure, Tiffany Layne

Master of Science in Forensic Science Directed Research Projects

In an attempt to determine the boundaries of degradation in nucleic acids with increased sensitivity, and provide support for a molecular method for body fluid identification, this study used specific treatments that are commonly found in crime scenes or are present in our daily environment to degrade DNA, messenger RNA, and microRNA in bodily fluids. Recently, the forensic science field has explored the use of RNAs regarding a molecular-based method for forensic body fluid identification. Specifically, messenger RNAs and microRNAs have been researched as markers for body fluids. Messenger RNAs are multifunctional and are shorter than DNA and some are …

Speed And Resolution In The Age Of Technological Reproducibility, Shawn Taylor

Theses and Dissertations

The rate of acceleration of the biologic and synthetic world has for a while now, been in the process of exponentially speeding up, maxing out servers and landfills, merging with each other, destroying each other. The last prehistoric relics on Earth are absorbing the same oxygen, carbon dioxide and electronic waves in our biosphere as us. A degraded .jpeg enlarged to full screen on a Samsung 4K UHD HU8550 Series Smart TV - 85” Class (84.5” diag.). Within this composite ecology, the ancient limestone of the grand canyon competes with the iMax movie of itself, the production of Mac pros, …

Proof-Of-Concept Of Environmental Dna Tools For Atlantic Sturgeon Management, Jameson Hinkle

Theses and Dissertations

Abstract

The Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus, Mitchell) is an anadromous species that spawns in tidal freshwater rivers from Canada to Florida. Overfishing, river sedimentation and alteration of the river bottom have decreased Atlantic Sturgeon populations, and NOAA lists the species as endangered. Ecologists sometimes find it difficult to locate individuals of a species that is rare, endangered or invasive. The need for methods less invasive that can create more resolution of cryptic species presence is necessary. Environmental DNA (eDNA) is a non-invasive means of detecting rare, endangered, or invasive species by isolating nuclear or mitochondrial DNA (mtDNA) from the …

Consequences Of Vine Infestation: Linking Abiotic Influences And Biotic Interactions To Successional And Structural Changes In Coastal Communities, Spencer N. Bissett

Theses and Dissertations

Located at the interfaces of terrestrial and marine environments, coastal habitats are inherently vulnerable to the effects of global change. Barrier island systems in particular serve not only as protective buffers against storm events, but also as sentinel ecosystems for observation of the impacts of sea level rise, and of increasing storm frequency and intensity. In the mid-Atlantic region, shrub thickets of Morella species compose the dominant forest community. The often monospecific nature of these plant community assemblages is advantageous to ecological studies and cross-scale applications; the relatively low diversity facilitates transitions between scales. My objective was to investigate the …

The Genetic Architecture Of Water-Use Efficiency Within And Between Two Natural Populations Of Foxtail Pine, Douglas E. Harwood

Theses and Dissertations

The goal of this project was to determine the genetic architecture of water-use efficiency (WUE) for foxtail pine, which included genomic loci, and effect sizes of this trait. Foxtail pine is a subalpine endemic conifer that inhabits two distinct regional populations separated by 500 km in the mountains of California. In order to achieve this goal, a robust linkage map containing thousands of genetic markers was created using four megagametophyte arrays ranging in size from approximately 70 to 95 megagametophytes. Quantitative trait loci (QTL) discovered for WUE were mapped along the linkage map using linear mixed models and five half-sibling …

Modeling Atp-Binding Cassette G2 (Abcg2) Substrate Specificity, Raghav D. Acharya, Aurijit Sarkar, Glen E. Kellogg

UROP Posters

How well can we predict efflux by ATP-binding cassette G2?

It is estimated that there will be about 1.6 million new cases of cancer and half a million cancer deaths in the US during 2015.ATP-binding cassette (ABC) efflux transporters such as ABCG2 are overexpressed in chemotherapy-resistant cancer cells. Anticancer drugs are prone to efflux by these transporters. Being able to identify drugs that are effluxed is of great interest in drug discovery.The current arsenal of methods used to detect efflux are not easily adaptable to high throughput formats and are limited in scope, making experimental analysis an expensive prospect. Hence, …

Smoking Patterns Among Vcu Students, Jasmine Saini

UROP Posters

For some individuals, college can be a high risk time for the development of problems associated with alcohol use and other substances. The purpose of this study is to examine these initiation and use patterns as they relate to nicotine use among college students 18 years of age and older enrolled in Spit for Science: The VCU Student Survey. The Spit for Science research project evaluates how genetic and environmental factors contribute to substance use and emotional health among college students at VCU. This study uses data from the Spit for Science 2011 cohort (n=2007) to investigate smoking patterns among …

Multi-Platform Arabinoxylan Scaffolds As Potential Wound Dressing Materials, Donald C. Aduba Jr

Theses and Dissertations

Biopolymers are becoming more attractive as advanced wound dressings because of their naturally derived origin, abundance, low cost and high compatibility with the wound environment. Arabinoxylan (AX) is a class of polysaccharide polymers derived from cereal grains that are primarily used in food products and cosmetic additives. Its application as a wound dressing material has yet to be realized. In this two-pronged project, arabinoxylan ferulate (AXF) was fabricated into electrospun fibers and gel foams to be evaluated as platforms for wound dressing materials. In the first study, AXF was electrospun with varying amounts of gelatin. In the second study, AXF …

Effects Of The Algal Toxin Microcystin On Fishes In The James River, Virginia, Maxwell D. Haase

Theses and Dissertations

With the global rise in frequency of harmful algal blooms in estuarine environments comes an increase in prevalence of toxic metabolites, such as microcystin (MC), that some of the cyanobacteria involved will produce. At high concentrations, MC may accumulate in consumer tissues and have deleterious effects on organisms; however impacts of the toxin on aquatic living resources at ecologically relevant concentrations have not been widely documented. We analyzed the effects of MC on juveniles of five fish species from the James River, Virginia to determine if MC has the potential to impede growth. Using three separate experimental approaches, it was …

Roles Of Seed Dispersal And Environmental Filters In Establishment Of The Dominant Shrubs: Morella Cerifera And M. Pensylvanica, On An Atlantic Barrier Island, Benjamin Dows

Theses and Dissertations

Patterns of the expansion of woody cover into grasslands on barrier islands of the Virginia coast were investigated. Seed dispersal of the dominant shrub Morella spp., was sampled deploying seed traps (n = 82) throughout a landscape under shrub encroachment pressure on Hog Island, VA. Traps were placed underneath: fruiting Morella, non-fruiting Morella, co-occurring species (Iva frutescens and Baccharis halimifolia) and in grass land, (no shrub cover). Environmental filters that act upon dispersed seeds and subsequently determine establishment patterns were also investigated. Dispersal distribution throughout the encroachment zone was leptokurtic and dispersal among cover types suggest co-occurring shrub species facilitate …

A Passive Acoustic And Experimental Study Of Juvenile Blue Catfish, Ictalurus Furcatus, Sound Production And Agnostic Behavior In The Tidal Freshwater James River, Laura Morgan

Theses and Dissertations

Blue catfish, Ictalurus furcatus, are an invasive species in the James River, VA. They produce stridulation sounds and passive acoustic monitoring may prove useful in locating and monitoring their populations. Little is known about their behavior, therefore my goal was to examine agonistic behavior and the use of sound in defending a territory. This thesis consists of two manuscripts: 1) A passive acoustic study of the tidal freshwater James River, 2) An experimental study of agonistic behavior in juvenile Blue catfish, Ictalurus furcatus. The first study showed that three sounds (click, run croak) occurred more often in warmer months than …

Planar Cell Polarity And Neurodevelopment, Simon Sun

Theses and Dissertations

Planar cell polarity (PCP) is a developmental signaling mechanism that establishes a polarity within the plane of an epithelium. PCP has been shown to play a role in guiding numerous neurodevelopmental processes such as convergent extension, neuron migration, and axon pathfinding. Certain commissural neurons in the dorsal spinal cord make a series of guidance decisions en route to the brain: first, a ventral projection along the D-V axis, followed by a midline crossing, and after exiting the floorplate, a dorso-anterior turn along the A-P axis. Here, we provide in vivo evidence that the axons of the Commissural Primary Ascending (CoPAs) …

Understanding The Role Of Stylochus Ellipticus As A Predator Of Crassostrea Virginica In Chesapeake Bay Tributaries, Marion Kensey Barker

Theses and Dissertations

Predation may be a key component of the unsuccessful restoration of the Eastern Oyster (Crassostrea virginica), a former keystone species in Chesapeake Bay. Here, I examine the polyclad flatworm Stylochus ellipticus and its potential role as an important predator of C. virginica. Using small-fragment size C. virginica specific DNA primers, oyster DNA was successfully detected in whole organisms homogenates of wild-caught S. ellipticus individuals. Of the 1,575 individuals tested, 68.1% tested positive, thus predation occurred. Predation did not appear to be affected by salinity or temperature; however, season did appear to have an effect on both predation and S. ellipticus …

Conspecific Attraction In A Low-Density Population Of A Threatened Songbird, Daniel James Albrecht-Mallinger

Theses and Dissertations

Many organisms use both vegetation structure and social cues in selecting habitats. Many species of songbirds use the presence of breeding conspecifics as a social cue and sign of habitat quality, and can be induced to settle in unoccupied habitats by artificially broadcasting breeding song, a process referred to as “conspecific attraction”. In our study, we tested response to conspecific attraction a low-density population of the threatened Golden-winged Warbler (Vermivora chrysoptera) in Highland County, VA. Response to broadcast song was observed, with a modest increase in mean male abundance at survey points within 250 meters of treatments, and mean abundance …

Benthic Macroinvertebrate Subsampling Effort And Taxonomic Resolution For Bioassessments Of Streams In The James River Watershed Of Virginia, Laurel Williams

Theses and Dissertations

Benthic macroinvertebrate diversity influences stream food web dynamics, nutrient cycling and material exchange between the benthos and the water column. Stream bioassessment has moved to the forefront of water quality monitoring in terms of benthic macroinvertebrate diversity in the recent past. The objectives of this study were to determine optimum subsample size and level of taxonomic resolution necessary to accurately and precisely describe macroinvertebrate diversity in streams flowing in the Piedmont province of the James River watershed in Virginia. Forty-nine sampling sites were selected from streams within the Piedmont Physiographic Province of the James River watershed. Ten sites were randomly …

Forest Net Primary Production Resistance Across A Gradient Of Moderate Disturbance, Ellen Goodrich-Stuart

Theses and Dissertations

The global carbon (C) balance is vulnerable to disturbances that alter terrestrial C uptake and loss. Moderate disturbances that kill or defoliate only a subset of canopy trees such as insect defoliation, drought, and age-related senescence are increasing in extent and frequency; yet, little is known about the effect of moderate disturbance on forest production and the mechanisms sustaining or supporting the recovery of the C cycle across a range of moderate disturbance severities. We used a broad plot-scale gradient of upper canopy tree mortality within a large manipulation of forest disturbance to: 1) quantify how aboveground wood net primary …

Indirect Effects Between Deer, Mice, And The Gypsy Moth In A Forest Community, John Wojcikiewicz

Theses and Dissertations

White-tailed deer are ecosystem engineers that dramatically alter forest understory vegetation. Consequently, deer can impact many species in a forest through both direct and indirect effects. One species that deer may indirectly affect is the gypsy moth, whose pupae are preyed upon by the white-footed mouse. Through alterations to understory habitat of mice, deer may reduce mouse predation on gypsy moth pupae. In this study, I tested for indirect effects of deer on the gypsy moth by comparing mouse abundance, vegetation properties, and predation on pupae inside, and outside, of long-term deer exclosures. Overall, I did not find evidence for …

The Occurrence And Consequences Of Conspecific Brood Parasitism In The Prothonotary Warbler (Protonotaria Citrea), Anna Tucker

Theses and Dissertations

Brood parasites avoid costs associated with raising young by adding eggs to another individual’s clutch and providing no parental care. When conspecific brood parasitism occurs in species with high parental investment, we expect hosts to suffer costs for raising an enlarged brood. Here I describe conspecific brood parasitism (CBP) in the prothonotary warbler using maternal exclusion analyses of 333 family groups. I found that 23.4% of clutches contained at least one offspring that was not matched to the social mother and determined that parasitism seems to be an opportunistic tactic. Hosts had lower average annual reproductive success than non-hosts, but …

Forest Edges Enhance Mate-Finding In The European Gypsy Moth, Lymantria Dispar, Lily Thompson

Theses and Dissertations

Understanding movement capabilities of individuals within a landscape is essential to identifying the effects of habitat boundaries on species abundances, ranges, and spread rates. Movement barriers due to habitat fragmentation may reduce mate-finding ability in some species, particularly in heterogeneous landscapes containing low-density populations. This study focuses on the effects of habitat type and edge on mate-finding in an invasive defoliator, the European gypsy moth. Adult European gypsy moth males locate mates by following pheromones released by flightless females. Reduced mate-finding was expected in fields and near forest edges based on geographic variation in invasion rates and pheromone plume dynamics. …

Hydroxocobalamin Treatment For Carbon Monoxide Exposures: Characterizing Hemoglobin Changes And Testing For Neurological Sequelae, Leonardo Somera

Theses and Dissertations

Prior work in our lab has indicated that reduced Hydroxocobalamin (B12r) can be added to human blood and is able to convert carbon monoxide (CO) into carbon dioxide. This has great potential as a direct antidote to mitigate the toxic effects of CO poisoning which is a public health risk. In the first part of our work, we use highly specific wavelengths of light and Raman spectroscopy to study changes in Carboxyhemoglobin (COHb) between blood treated with oxygen and blood treated with oxygen and B12r in a flowing circuit of blood. Using Raman spectroscopy, we found that the addition of …

Barrier Island Morphology And Sediment Characteristics Affect The Recovery Of Dune Building Grasses Following Storm-Induced Overwash, Steven T. Brantley, Spencer Bissett, Donald R. Young, Catherine W. V. Wolner, Laura J. Moore

Biology Publications

Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed) barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily …

In Vitro Propagation Of Gentiana Scabra Bunge – An Important Medicinal Plant In The Chinese System Of Medicines, Shih-Hung Huang, Dinesh Chandra Agrawal, Fang-Sheng Wu, Hsin-Sheng Tsay

Biology Publications

Background: Gentiana scabra Bunge commonly known as `Long dan cao' in China has been used in traditional Chinese medicines for more than 2000 years. Dry roots and rhizome of the herb have been used for the treatment of inflammation, anorexia, indigestion and gastric infections. Iridoids and secoiridoids are the main bioactive compounds which attribute to the pharmacological properties of this plant. The species is difficult to mass propagate by seed due to the low percentage of germination and limited dormancy period. Wild populations in some locations are considered to be in the endangered category due to over exploitation.

Results: In …

On The Challenges Of Modeling The Net Radiative Forcing Of Wetlands: Reconsidering Mitsch Et Al. 2013, Scott C. Neubauer

Biology Publications

Wetlands play a role in regulating global climate by removing carbon dioxide (CO2) from the atmosphere and sequestering it as soil carbon, and by emitting methane (CH4) and nitrous oxide (N2O) to the atmosphere. In a recent article in this journal (Mitsch et al. Landscape Ecol 28:583–597, 2013), CO2 sequestration and CH4 emissions were modeled for several freshwater wetlands that vary in vegetation type, climate, and hydrology. The authors of that study made significant errors that caused them to underestimate the importance of wetland CH4 emissions on climate dynamics. Here, I reanalyze the Mitsch et al. dataset and show that …

Reduction Of The Pectoral Spine And Girdle In Domesticated Channel Catfish Is Likely Caused By Changes In Selection Pressure, Michael L. Fine

Biology Publications

Locked pectoral spines of the Channel Catfish Ictalurus punctatus more than double the fish's width and complicate ingestion by gape-limited predators. The spine mates with the pectoral girdle, a robust structure that anchors the spine. This study demonstrates that both spine and girdle exhibit negative allometric growth and that pectoral spines and girdles are lighter in domesticated than in wild Channel Catfish. This finding could be explained by changes in selection pressure for spine growth during domestication or by an epigenetic effect in which exposure to predators in wild fish stimulates pectoral growth. We tested the epigenetic hypothesis by exposing …