Life Sciences Commons^™

Decreased Temperature Variance Associated With Biotic Composition Enhances Coastal Shrub Encroachment, Lauren K. Wood, Spencer Hays, Julie C. Zinnert

Biology Publications

Regime shift from grasslands to shrub-dominated landscapes occur worldwide driven by altered land-use and climate change, affecting landscape function, biodiversity, and productivity. Warming winter temperatures are a main driver of expansion of the native, evergreen shrub, Morella cerifera, in coastal landscapes. Shrub establishment in these habitats alters microclimate, but little is known about seasonal differences and microclimate variance. We assessed influence of shrubs on microclimate variance, community composition, and community physiological functioning across three vegetation zones: grass, transitional, and shrub in a coastal grassland. Using a novel application of a time-series analysis, we interpret microclimatic variance modification and elucidate …

Topography And Disturbance Influence Trait‐Based Composition And Productivity Of Adjacent Habitats In A Coastal System, Joseph K. Brown, Julie C. Zinnert

Biology Publications

Coastal systems experience frequent disturbance and multiple environmental stressors over short spatial and temporal scales. Investigating functional traits in coastal systems has the potential to inform how variation in disturbance frequency and environmental variables influence differences in trait‐based community composition and ecosystem function. Our goals were to (1) quantify trait‐based communities on two barrier islands divergent in topography and long‐term disturbance response and (2) determine relationships between community trait‐based composition and ecosystem productivity. We hypothesized that locations documented with high disturbance would have habitats with similar environmental conditions and trait‐based communities, with the opposite relationship in low‐disturbance locations. Furthermore, we …

Ovarian Transcriptomic Analyses In The Urban Human Health Pest, The Western Black Widow Spider, Lindsay S. Miles, Nadia A. Ayoub, Jessica E. Garb, Robert A. Haney, Brian C. Verrelli

Center for Integrative Life Sciences Education Publications

Due to their abundance and ability to invade diverse environments, many arthropods have become pests of economic and health concern, especially in urban areas. Transcriptomic analyses of arthropod ovaries have provided insight into life history variation and fecundity, yet there are few studies in spiders despite their diversity within arthropods. Here, we generated a de novo ovarian transcriptome from 10 individuals of the western black widow spider (Latrodectus hesperus), a human health pest of high abundance in urban areas, to conduct comparative ovarian transcriptomic analyses. Biological processes enriched for metabolism—specifically purine, and thiamine metabolic pathways linked to oocyte …

Seasonal Facilitative And Competitive Trade‐Offs Between Shrub Seedlings And Coastal Grasses, Michael N. Sinclair, Natasha N. Woods, Julie C. Zinnert

Biology Publications

Shrub expansion is occurring in grasslands globally and may be impacted by the balance of competition and facilitation with existing grasses. Along the mid‐Atlantic and Gulf coasts, the native shrub Morella cerifera (wax myrtle) is rapidly expanding and displacing other native coastal species. Recent research suggests that much of this expansion is due to warming winter temperatures, as temperatures below −15°C kill M. cerifera. The objective of this project was to understand the importance of species interactions with grasses on the growth and physiology of M. cerifera at the seedling life stage through both field and laboratory experiments. In …

Impacts Of Beef Concentrated Animal Feeding Operations On Environmental Sustainability In The United States And Practices For Improvement, Laura Clark

VCU Phi Kappa Phi Award Winners

The geographic concentration of beef concentrated animal feeding operations [CAFOs] has changed the landscape of environmental sustainability for agriculture in the United States. As land availability has decreased, operations have struggled to maintain feasible practices to minimize environmental detriment. The United States Environmental Protection Agency [EPA] imposed rules to be followed as a means of mitigation, but the fast-paced rate of change minimizes effectiveness. The overall environmental sustainability of beef CAFOs has shifted from historical rates, leading to a need for reassessment. Part of this reassessment will include stronger environmental practices to be considered for implementation. I explored the role …

The Utilization Of Sex Hormone Antibodies For Screening And Separation Of Trace Biological Mixtures, Kristin N. Jones

Master of Science in Forensic Science Directed Research Projects

Touch or trace evidence consists of epidermal cells deposited by contact with items such as handled objects, touched surfaces, or worn clothes. This type of evidence has surpassed most other sample types submitted to forensic labs and typically consists of low quantities of DNA and multiple contributors. In this study epithelial skin cells, i.e., “touch/trace evidence,” were used as they are estimated to constitute approximately half of the casework evidence items submitted for DNA analysis. For the optimization of antibody staining, male and female skin epithelial samples from donors were incubated and hybridized with antibodies of various concentrations of Alexa …

Non-Destructive, Rapid Differentiation Of Cell Types Relevant To Sexual Assault Investigations Utilizing Morphological And Autofluorescence Signatures, Taylor R. Moldenhauer

Master of Science in Forensic Science Directed Research Projects

Current methods for confirming the presence of spermatozoa in sexual assault samples can be time-consuming and often lack sensitivity; however, this remains the most definitive test for the presence of semen. Additionally, male DNA can be deposited without the presence of intact sperm as may be the case with seminal fluid from vasectomized individuals or sexual activity where seminal fluid is not recovered (e.g., perpetrator wears a condom, penetration without ejaculation, etc.). The ability to detect bodily fluids, as well as quantify their presence in a sample, could aid in forensic DNA analysis by limiting the amount of time performing …

The Substantiality Of The Neuroplasticity Hypothesis Of Major Depressive Disorder: The Prospective Use Of Ketamine-Like Drugs As Antidepressants, Roma Kankaria

Auctus: The Journal of Undergraduate Research and Creative Scholarship

Abstract

Major depressive disorder (MDD) affects approximately 17.3 million adults in the United States each year. For more than 50 years, the serotonin hypothesis of MDD, which hypothesizes that a deficiency of monoaminergic neurotransmitters results in depression, has been the foundation for neuropsychological research. However, studies reveal that only an estimated 50% of MDD patients respond to traditional, biogenic-amine-based antidepressants (ADs), like selective serotonin reuptake inhibitors (SSRIs). Research has noted that the neuroplasticity hypothesis, which posits that weakened excitatory synaptic transmission results in depression, offers an alternative mechanism by which ketamine-like drugs lacking the abuse liability and psychoactive effects of …

The Utilization Of Eukaryotic Cell Types In Microbiomes For Semen, Vaginal Fluid, And Menstrual Blood Identification Using 18s Rdna, Ines Benaissa

Master of Science in Forensic Science Directed Research Projects

The accurate identification of body fluids is vital for crime scene investigation and forensic analysis. While many body fluids can be presumptively identified, there is a lack of confirmatory testing for verification. Therefore, the purpose of this study was to determine if body fluids (menstrual blood, vaginal fluid, and semen) could be differentiated based on their eukaryotic microbial communities. The target area of interest was the V9 hyper-variable region of 18S ribosomal DNA (18S rDNA). The samples were extracted, barcoded using a duel-index strategy, and PCR amplified before undergoing high throughput sequencing using the Illumina Miseq FGx instrument. The samples …

Development Of An Untargeted Gas Chromatography-Mass Spectrometry (Gc/Ms) Method For The Detection Of Drugs In Wastewater, Samuel A. Miller

Master of Science in Forensic Science Directed Research Projects

Monitoring current illicit drug trends and consumption rates of pharmaceuticals using a non-invasive collection technique is needed to address the present drug use and the growing drug epidemic. Reliance on self-reporting drug use surveys is not always a practical measure of illicit drug use. Wastewater analysis has been used globally as a targeted method for monitoring the consumption of specific illicit drugs. Current existing analytical techniques for wastewater analysis focus on the use of targeted liquid chromatography-mass spectrometry (LC-MS) based techniques. Few gas chromatography (GC) procedures exist for wastewater analysis, and those that do concentrate their methods on a single …

A Eukaryotic Signature Based Method For Identification Of Saliva, Feces, And Urine, Alyssa Daniels

Master of Science in Forensic Science Directed Research Projects

The conception of the Human Microbiome Project advanced the understanding of microbial communities in the human body and previous research has established that unique microbial signatures can help distinguish each body fluid. While these signatures have been developed for the prokaryotic microbiome, the next step is the examination of the eukaryotic microbiome. Eukaryotic signatures could provide a greater specificity and statistical weight when discerning between body fluids. These microbial markers can be implemented to develop a confirmatory assay for body fluid identification that works in tandem with other DNA based methods in the forensic workflow. Using a VCU approved IRB …

Application Of Optical Trapping To Obtain Single-Source Str Profiles From Forensically Relevant Body Fluid Mixtures With Modified Dna Analysis Workflow, Benjamin J. O'Brien

Master of Science in Forensic Science Directed Research Projects

Current methods of mixture separation in forensic DNA laboratories typically deconvolute the mixture after analysis using statistical analysis or probabilistic genotyping. To save time and effort of labs already backlogged, a method to separate mixtures on a cellular level before analysis needs to be developed. Optical trapping is a method that uses a focused 1064 nm laser to manipulate cells. Previous research has shown that approximately 50 spermatozoa or 15 leukocytes from a liquid sample are required to produce a full STR DNA profile. It was found that the number of spermatozoa required remains constant when the method of sample …

Development Of A Quantitative Pcr (Qpcr) Based Method For Studying Temporal Dna Degradation In Waterlogged Bone, Isis Thornton

Master of Science in Forensic Science Directed Research Projects

Human activities are often centered around the presence of water, thus it is not surprising that there are many water-related human deaths. Accumulated degree days (ADD), and other aquatic variables may affect DNA retrieval from waterlogged bone. Calcium and collagen in bone can inhibit the PCR necessary to produce an STR profile; the current solution is a time-consuming organic extraction. While there are examples of research on DNA degradation in terrestrial bone over time, there has been little work done on submerged bone samples and they are usually limited to case studies. The major aim of this study was to …