Life Sciences Commons^™

Temporal Variability And Cooperative Breeding: Testing The Bet-Hedging Hypothesis In The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters

Biological Sciences Faculty Publications

Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenonmay be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) inpopulations living inhighly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker (Melanerpes formicivorus). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance …

Groundwater Thresholds For Root Decomposition And The Relation To Barrier Island Ecological State Changes, Matthew Lee Smith

Biological Sciences Theses & Dissertations

Barrier islands off the eastern shore of Virginia exhibit distinct habitats that abruptly transition between periodically brackish/freshwater marshes, wooded swales, and sparsely vegetated dunes. There is strong evidence that the plant communities and ecosystem processes occurring in each habitat are primarily influenced by nutrient availability and the distance between two of the three free surfaces: land and freshwater. At the Virginia Coast Reserve-Long Term Ecological Research Site in Virginia, USA, thresholds to belowground decomposition rates were identified by measuring decay of native roots and rhizomes at 32 elevations in relation to mean annual groundwater levels (-0.356 – 1.937 m). Negative …

Determining The Prevalence And Distribution Of Tick-Borne Pathogens In Southeastern Virginia And Exploring The Transmission Dynamics Of Rickettsia Parkeri In Amblyomma Maculatum, Chelsea L. Wright Thompson

Biological Sciences Theses & Dissertations

Tick-borne pathogens are an increasing threat to human and animal health worldwide. In the United States, cases of Lyme disease, spotted fever rickettsioses, ehrlichiosis and anaplasmosis are on the rise. Factors related to emergence include appearance of a new pathogen, recognition of an existing pathogen and environmental changes that result in new exposure events. Despite the rise in tick-borne disease incidence within many states, including Virginia, there is a paucity of data related to the prevalence and distribution of ticks and tick-borne pathogens.

The first aim of this dissertation research was to determine the tick-borne pathogen composition within tick populations …

Molecular Phylogeny Of The Genus Houstonia And Allies In Rubiaceae, Hunter Lee Shanks

Biological Sciences Theses & Dissertations

Houstonia (Rubiaceae) is a strictly North American genus of 24 species distributed from Mexico, throughout the United States, up to Canada. Houstonia has proven to be a taxonomically difficult genus since the Linnaean description of Houstonia and the related genera: Hedyotis and Oldenlandia in 1753. For over 250 years botanists have lumped and separated Houstonia from Hedyotis and Oldenlandia based on various morphological characters. The most recent circumscription of Houstonia (Terrell 1996) separated the genus into two subgenera with each subgenus containing two sections. Nuclear (ITS) and plastid (trnL-F, rps16) DNA sequences were used to build a molecular phylogeny depicting …

Behavioral Immunity Suppresses An Epizootic In Caribbean Spiny Lobsters, Mark J. Butler Iv, Donald C. Behringer Jr., Thomas W. Dolan Iii, Jessica Moss, Jeffrey D. Shields

Biological Sciences Faculty Publications

Sociality has evolved in a wide range of animal taxa but infectious diseases spread rapidly in populations of aggregated individuals, potentially negating the advantages of their social interactions. To disengage from the coevolutionary struggle with pathogens, some hosts have evolved various forms of "behavioral immunity"; yet, the effectiveness of such behaviors in controlling epizootics in the wild is untested. Here we show how one form of behavioral immunity (i.e., the aversion of diseased conspecifics) practiced by Caribbean spiny lobsters (Panulirus argus) when subject to the socially transmitted PaV1 virus, appears to have prevented an epizootic over a large seascape. We …

Section Abstracts: Biology With Microbiology And Molecular Biology

Virginia Journal of Science

Abstracts of the Biology with Microbiology and Molecular Biology Section for the 93rd Annual Meeting of the Virginia Academy of Science, May 21-23, 2015, James Madison University, Richmond, Virginia

Section Abstracts: Natural History And Biodiversity

Virginia Journal of Science

Abstracts of the Natural History and Biodiversity Section for the 93rd Annual Meeting of the Virginia Academy of Science, May 21-23, 2015, James Madison University, Richmond, Virginia

Blue Carbon In Freshwater / Brackish Marshes On The Barrier Islands Of Virginia Aboveground Net Primary Productivity And Carbon Pools, Emily Caitlin Adams

Biological Sciences Theses & Dissertations

"Blue carbon" is a relatively new concept describing carbon distributed tidally and sequestered via net production within coastal ecosystems, including seagrass beds, mangrove forests, and salt-water marshes. These systems sequester carbon at least 10 times faster than terrestrial systems. Fresh to brackish wetlands that receive irregular tidal influence due to overwash and storm events have not been typically studied as blue carbon systems. My objective was to quantify carbon pools within four interdunal fresh to brackish marshes on Hog Island, Virginia to determine their blue carbon potential. Marshes 1 and 2 were farthest from the ocean, below and above a …

Plasma Activated Air Mediates Gene Transfer, Chelsea M. Edelblute

Biological Sciences Theses & Dissertations

Cold plasma is produced when strong applied electric fields accelerate free electrons, which dissociate, excite, or ionize gaseous molecules [1]. The deposition of ions from the plasma source is dependent on power generation, input gas composition, and gas flow rate. In the presence of reactive species, the membrane of eukaryotic cells is compromised allowing for otherwise impermeant molecules, such as DNA, to enter the inner-cell milieu [2].

The efficacy of a novel cold plasma reactor based on shielded sliding discharge for the delivery of plasmid DNA was assessed. The device is entirely non-contact, wherein the plasma never directly touches the …

Blue Carbon In Coastal Freshwater/Brackish Marshes On The Barrier Islands Of Virginia: Belowground Carbon Dynamics, Nathan M. Sedghi

Biological Sciences Theses & Dissertations

Some coastal ecosystems sequester substantially more carbon (blue carbon) than land locked systems due to high net primary production and deposition associated with oceanic influences. Most blue carbon research has focused on mangroves, seagrass beds, and salt marshes. Studies on blue carbon potential of coastal freshwater marshes are less common. Barrier islands frequently flood, with seawater reaching interior ecosystems. I examined brackish/freshwater marshes on Virginia barrier islands for possible roles as blue carbon systems. I studied four interior marshes on Hog Island, which varied in proximity to a direct overwash path and protection by a trail berm that divides northern …

Computational Development For Secondary Structure Detection From Three-Dimensional Images Of Cryo-Electron Microscopy, Dong Si

Computer Science Theses & Dissertations

Electron cryo-microscopy (cryo-EM) as a cutting edge technology has carved a niche for itself in the study of large-scale protein complex. Although the protein backbone of complexes cannot be derived directly from the medium resolution (5-10 Å) of amino acids from three-dimensional (3D) density images, secondary structure elements (SSEs) such as alpha-helices and beta-sheets can still be detected. The accuracy of SSE detection from the volumetric protein density images is critical for ab initio backbone structure derivation in cryo-EM. So far it is challenging to detect the SSEs automatically and accurately from the density images at these resolutions. This dissertation …

Amphibian And Small Mammal Assemblages In A Northern Virginia Forest Before And After Defoliation By Gypsy Moths (Lymantria Dispar), Joseph C. Mitchell

Virginia Journal of Science

The introduced European gypsy moth (Lymantria dispar) caused substantial defoliation and mortality of oak trees along the North Fork of Quantico Creek in Prince William Forest Park, Prince William County, Virginia, U.S.A., in 1989 and the early 1990s. Results of a drift fence/pitfall study conducted in 1988 were compared to those obtained from the same technique in the same areas in 1993 to elucidate whether the amphibian and small mammal assemblages had changed over time. Number of Lithobates sylvaticus increased significantly in 1993, but the numbers of Lithobates clamitans and Plethodon cinereus were significantly higher in 1988. Total …

Transmission-Blocking Vaccines: Focus On Anti-Vector Vaccines Against Tick-Borne Diseases, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Tick-borne diseases are a potential threat that account for significant morbidity and mortality in human population worldwide. Vaccines are not available to treat several of the tick-borne diseases. With the emergence and resurgence of several tick-borne diseases, emphasis on the development of transmission-blocking vaccines remains increasing. In this review, we provide a snap shot on some of the potential candidates for the development of anti-vector vaccines (a form of transmission-blocking vaccines) against wide range of hard and soft ticks that include Ixodes, Haemaphysalis, Dermacentor, Amblyomma, Rhipicephalus and Ornithodoros species.

Mutations In The Plasmodium Falciparum Chloroquine Resistance Transporter, Pfcrt, Enlarge The Parasite's Food Vacuole And Alter Drug Sensitivities, Serena Pulcini, Henry M. Staines, Andrew H. Lee, Sarah H. Shafik, Guillaume Bouyer, Catherine M. Moore, Daniel A. Daley, Matthew J. Hoke, Lindsey M. Altenhofen, Heather J. Painter, Jainbing Mu, David J.P. Ferguson, Manuel Llinás, Rowena E. Martin, David A. Fidock, Roland A. Cooper, Sanjeev Krishna

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine resistance transporter, PfCRT, are the major determinant of chloroquine resistance in this lethal human malaria parasite. Here, we describe P. falciparum lines subjected to selection by amantadine or blasticidin that carry PfCRT mutations (C101F or L272F), causing the development of enlarged food vacuoles. These parasites also have increased sensitivity to chloroquine and some other quinoline antimalarials, but exhibit no or minimal change in sensitivity to artemisinins, when compared with parental strains. A transgenic parasite line expressing the L272F variant of PfCRT confirmed this increased chloroquine sensitivity and enlarged food vacuole phenotype. Furthermore, the introduction …

Comparative Population Genetics Of Two Invading Ticks: Evidence Of The Ecological Mechanisms Underlying Tick Range Expansions, Robyn Nadolny, Holly Gaff, Jens Carlsson, David Gauthier

Biological Sciences Faculty Publications

Two species of ixodid tick, Ixodes affinis Neumann and Amblyomma maculatum Koch, are simultaneously expanding their ranges throughout the mid-Atlantic region of the US. Although we have some understanding of the ecology and life history of these species, the ecological mechanisms governing where and how new populations establish and persist are unclear. To assess population connectivity and ancestry, we sequenced a fragment of the 16S mitochondrial rRNA gene from a representative sample of individuals of both species from populations throughout the eastern US. We found that despite overlapping host preferences throughout ontogeny, each species exhibited very different genetic and geographic …

Climate, Environmental And Socio-Economic Change: Weighing Up The Balance In Vector-Borne Disease Transmission, Paul E. Parham, Joanna Waldock, George K. Christophides, Deborah Hemming, Folashade Agusto, Katherine J. Evans, Nina Fefferman, Holly Gaff, Abba Gumel, Shannon Ladeau

Biological Sciences Faculty Publications

Arguably one of the most important effects of climate change is the potential impact on human health. While this is likely to take many forms, the implications for future transmission of vector-borne diseases (VBDs), given their ongoing contribution to global disease burden, are both extremely important and highly uncertain. In part, this is owing not only to data limitations and methodological challenges when integrating climate-driven VBD models and climate change projections, but also, perhaps most crucially, to the multitude of epidemiological, ecological and socio-economic factors that drive VBD transmission, and this complexity has generated considerable debate over the past 10-15 …

A Robust Deep Model For Improved Classification Of Ad/Mci Patients, Feng Li, Loc Tran, Kim-Han Thung, Shuiwang Ji, Dinggang Shen, Jiang Li

Electrical & Computer Engineering Faculty Publications

Accurate classification of Alzheimer's disease (AD) and its prodromal stage, mild cognitive impairment (MCI), plays a critical role in possibly preventing progression of memory impairment and improving quality of life for AD patients. Among many research tasks, it is of a particular interest to identify noninvasive imaging biomarkers for AD diagnosis. In this paper, we present a robust deep learning system to identify different progression stages of AD patients based on MRI and PET scans. We utilized the dropout technique to improve classical deep learning by preventing its weight coadaptation, which is a typical cause of overfitting in deep learning. …

A Popular And Potentially Sustainable Fishery Resource Under Pressure-Extinction Risk And Conservation Of Brazilian Sciaenidae (Teleostei: Perciformes), Ning L. Chao, Flávia L. Frédou, Manuel Haimovici, Monica B. Peres, Beth Polidoro, Marcelo Raseira, Rosana Subira, Kent E. Carpenter

Biological Sciences Faculty Publications

Croakers (Sciaenidae) are major fishery resource in Brazil; constituting 22% of marine and 9% of freshwater fishery landings. Croakers are subject to heavy fishing pressure throughout Brazil, but habitat alteration is also an important threat to regional populations. In this regional Sciaenidae assessment, each species was analyzed for relative risk of extinction, including the identification and quantification of the impact of major threats and existing conservation measures, based on application of the Categories and Criteria of the IUCN Red List of Threatened Species. Of the 52 species of Sciaenid fishes (34 marine and 18 freshwater) present in Brazilian waters, the …

Identification And Comparative Analysis Of Subolesin/Akirin Ortholog From Ornithodoros Turicata Ticks, Hameeda Sultana, Unnati Patel, Daniel E. Sonenshine, Girish Neelakanta

Biological Sciences Faculty Publications

Background: Subolesin is an evolutionary conserved molecule in diverse arthropod species that play an important role in the regulation of genes involved in immune responses, blood digestion, reproduction and development. In this study, we have identified a subolesin ortholog from soft ticks Ornithodoros turicata, the vector of the relapsing fever spirochete in the United States.

Methods: Uninfected fed or unfed O. turicata ticks were used throughout this study. The subolesin mRNA was amplified by reverse transcription polymerase chain reaction (RT-PCR) and sequenced. Quantitative-real time PCR (QRT-PCR) was performed to evaluate subolesin mRNA levels at different O. turicata developmental stages …

Are Semen Quality Parameters Sufficient For Biomonitoring Spermatozoa Dna Integrity And Oxidatively Damaged Dna, Hueiwang Anna Jeng, Ruei-Nian Li, Wen-Yi Lin

Community & Environmental Health Faculty Publications

The present study aimed to investigate the relationship between semen quality parameters and DNA integrity, and determine whether semen quality parameters could serve as a reliable biomarker for monitoring sperm DNA damage. Conventional semen parameters from a total of 202 male human subjects were analyzed. DNA fragmentation and 8-oxo-7,8-dihydro-2′- deoxyguanosine (8-oxoGuo) were used to assess sperm DNA integrity. DNA fragmentation was analyzed by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and sperm chromatin structure assay (SCSA), while 8-oxodGuo was quantified by the liquid chromatography/tandem mass spectrometry (LC-MS/MS) coupled with an on-line solid phase system. The levels of …

Electroporation Of Mammalian Cells By Nanosecond Electric Field Oscillations And It's Inhibition By The Electric Field Reversal, Elena C. Gianulis, Jimo Lee, Chunqi Jiang, Shu Xiao, Bennet L. Ibey, Andrei G. Pakhomov

Bioelectrics Publications

The present study compared electroporation efficiency of bipolar and unipolar nanosecond electric field oscillations (NEFO). Bipolar NEFO was a damped sine wave with 140 ns first phase duration at 50% height; the peak amplitude of phases 2-4 decreased to 35%, 12%, and 7% of the first phase. This waveform was rectified to produce unipolar NEFO by cutting off phases 2 and 4. Membrane permeabilization was quantified in CHO and GH₃ cells by uptake of a membrane integrity marker dye YO-PRO-1 (YP) and by the membrane conductance increase measured by patch clamp. For treatments with 1-20 unipolar NEFO, at 9.6-24 …

Life-History Aspects Of Moxostoma Cervinum (Blacktip Jumprock) In The Roanoke River, Virginia, Dezarai A. Thompson, John S. Bentley, Steven L. Powers

Virginia Journal of Science

Life-history aspects of Moxostoma cervinum(Blacktip Jumprock) were identified using specimens from recent collections and the Roanoke College Ichthyological Collection. The largest specimen examined was a female 161.27 mm SL and 66 months of age. Spawning appears to occur in May, with a mean of 2477.6 oocytes (SD = 2825.3) up to 1.54 mm diameter in gravid females. Sexual maturity appears to occur by 1-2 years of age in males and 2-3 years of age in females. Male to female ratio was not significantly different from 1:1. Chironomidae composed the bulk of the diet; while detritus, Trichoptera, Ephemeroptera, and Acari …

Peptide Inhibitor Of Complement C1 (Pic1) Rapidly Inhibits Complement Activation After Intravascular Injection In Rats, Julia A. Sharp, Pamela S. Hair, Haree K. Pallera, Parvathi S. Kumar, Clifford T. Mauriello, Julius O. Nyalwidhe, Cody A. Phelps, Dalnam Park, Nicole M. Thielens, Stephen M. Pascal, Waldon Chen, Diane M. Duffy, Frank A. Lattanzio, Kenji M. Cunnion, Neel K. Krishna

Chemistry & Biochemistry Faculty Publications

The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in preclinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1). In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator …

Predicting Effects Of Ocean Warming, Acidification, And Water Quality On Chesapeake Region Eelgrass, Richard C. Zimmerman, Victoria J. Hill, Charles L. Gallegos

OES Faculty Publications

Although environmental requirements of seagrasses have been studied for years, reliable metrics for predicting their response to current or future conditions remain elusive. Eelgrass (Zostera marina L.) populations of the Chesapeake region lie near the southern limit of their range in the Western North Atlantic, exposing them to increasing thermal stress as the climate warms. However, CO₂ stimulated photosynthesis may offset some of the negative effects of temperature stress. The combined effects of temperature, CO₂, and light availability controlled by water quality and epiphytes were explored using GrassLight, a bio-optical model that provided a predictive …