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Virginia Commonwealth University: Program Profile
No full textVirginia Commonwealth University (VCU) is an urban, public research university located in Richmond, Virginia. VCU is among only eighty-four R1 universities with a Carnegie Community Engagement classification, which is a testament to VCU’s strong commitment to integrating community engagement through teaching, research, and service to address societal challenges and improve the quality of life for all. The university enrolls more than 28,000 students, representing over one hundred countries. Eighty-five percent of students are Virginia residents, and more than half of all students represent ethnically diverse populations. Thirty-seven percent of all fall 2024 freshmen were first-generation college students. More than two hundred degree programs are offered, including top-ranked programs in the health sciences, arts, and social work
Honoring the First-year Seminar: Exploring High-impact Learning Experiences for the First Year in Honors: About the Authors
No full textHonoring the First-year Seminar: Exploring High-impact Learning Experiences for the First Year in Honors: About the Author
Update to: New Butterfly Taxa and Findings from Genomic Analyses
No full textDue to the United States government shutdown, GenBank services were unavailable, and accession numbers could not be obtained for the sequences reported in the original publication. This update provides the GenBank accession numbers for these sequences, together with additional taxonomic findings accumulated since the initial study. One genus, 16 species and four subspecies are proposed as new (type species or localities in parentheses): Madaga Grishin, gen. n. (Artitropa alaotrana Oberthür, 1916), Udranomia eurianus Grishin, sp. n. (Ecuador: Napo), Entheus dalina Grishin, sp. n. (Brazil: Pará), Entheus ambo Grishin, sp. n. (Colombia: Cauca), Entheus pico Grishin, sp. n. (Colombia: Valle del Cauca), Entheus punyo Grishin, sp. n. (Colombia: Cauca), Porphyrogenes castana Grishin, sp. n. (Brazil: Amazonas), Porphyrogenes foxias Grishin, sp. n. (Suriname), Porphyrogenes tornus Grishin, sp. n. (Brazil: Rondônia), Porphyrogenes sepia Grishin, sp. n. (Brazil: Rondônia), Bungalotis ryta Grishin, sp. n. (Panama: Chiriquí), Pseudodrephalys gap Grishin, sp. n. (Brazil: Rondônia), Grais ecuadoricus Grishin, sp. n. (Ecuador: Sucumbíos), Grais eremitus Grishin, sp. n. (USA: Texas), Hoodus westudus Grishin, sp. n. (Ecuador: Orellana), Eutus brunninotatus Grishin, sp. n. (Bolivia: Santa Cruz), Lento mysto Grishin, sp. n. (Bolivia: La Paz) and Porphyrogenes probus curvatus Grishin, ssp. n. (Costa Rica: San José) (Hesperiidae); and Eurema ella marca Grishin, ssp. n. (Peru: Cajamarca), Eurema agave panave Grishin, ssp. n. (Panama: Colón), and Eurema agave livara Grishin, ssp. n. (Ecuador: Bolívar) (Pieridae). Genomic sequencing revealed additional specimens of recently described species of Entheus Hübner, [1819], previously known from a single specimen. We treat the following taxa of Lasaia (Lasaia) H. Bates, 1868 (Riodinidae) as valid: L. rosamonda Weeks, 1900, stat. rest., L. callaina Clench, 1972, stat. rev., L. maria anna Clench, 1972, stat. rest., L. oaxacensis Grishin, 2024, stat. rest., and L. cola Grishin, 2025, stat. rest.; as well as Lissia laura (Evans, 1937) stat. nov. (not Lissia luehderi (Plötz, 1879)), and Ephyriades brunnea electra (Lintner, 1881), stat. nov. Lectotype and neotype are designated for Antigonus fumosus Plötz, 1884 (Brazil) and Anastrus stigmaticus Mabille, 1883 (Brazil), respectively, establishing these names as objective synonyms
Patch Mow Grazing: Investigating the Effects of Mowing on Forage Nutritive Value, the Biomass–Nutritive Value Relationship, and Herbivore Selection
No full textHerbivore foraging behavior plays a critical role in shaping grassland structural heterogeneity, with selection often driven by forage biomass and nutritive value. Currently, it is thought that herbivores primarily select areas that are greater in nutritive value, and low in biomass. More specifically, disturbances like fire and grazing have been thoroughly studied showing that recently burned and grazed areas are not only higher in nutritive value but disproportionately selected by herbivores in comparison to undisturbed areas. However, most studies address only narrow ranges of defoliation, comparing intensely defoliated sites (\u3c 10 cm) to those that are either not defoliated or have experienced a much longer time since defoliation, thereby decreasing grazing pressure as biomass increases. However, one of the most widely used methods of defoliation in grasslands, mowing, hasn’t been thoroughly studied for its effects on nutritive value, and how it impacts herbivore selection. Our study aimed to (1) evaluate how mowing treatments—i.e., short (5 cm), medium (18 cm), and tall (\u3e30 cm, unmown)—affect nutritive value and herbivore selection, (2) assess the relationship between biomass and nutritive value in a patch mown landscape (3) assess how forage biomass and nutritive metrics, including crude protein (CP) and total digestible nutrients (TDN), influence selection. We found that nutritive value was significantly greater in short-mown patches (5 cm) compared to other patch heights (18 cm to 30+ cm), while biomass was inversely related to nutritive value and digestibility regardless of treatment. Furthermore, we found that cattle selected for our short-mown patches 15–30% more than medium and tall patches. Selection was significantly greater in low biomass areas in comparison to high biomass areas. Areas with higher CP were selected for more than areas with lower CP, and areas with higher TDN were selected for more than those with lower TDN. Our study shows that mowing to a short height significantly increased nutritive value, and also herbivore selection. Our results suggest that herbivores prefer to graze in lower biomass higher nutritive value areas, demonstrating that the mechanism currently driving the creation of heterogeneity is achievable through other methods of defoliation, with defoliation intensity, resulting in lower biomass and higher nutritive value areas, likely being the driver of herbivore selection.
Advisor: Nichols A. McMilla
Crop, Soil Nutrient, and Soil Health Responses within Integrated Crop and Livestock Systems
No full textWe evaluated the influences of grazing livestock on crop production, soil nutrients, and soil health indicators of integrated crop livestock systems using three experiments during a seven-yr. period. Objectives were to (1) determine livestock grazing and cropping system effects on crop yield and soil properties across six yr. in corn-soybean (C-S) and wheat-corn-soybean (W-C-S) systems with and without periodic composted manure application, (2) explore seasonal variation in soil nutrient patterns over two yr., and (3) measure residual responses for corn grain yield plus soil health indicators in yr. seven following a six-yr. study. In experiment 1, neither livestock grazing (p ≥ 0.1261) nor cropping system (p ≥ 0.1640) affected corn, soybean or wheat grain yield or soil properties after six yr. During the final yr. of the experiment, soil biology biomass was greater in the three-crop system compared with the two-crop systems (p \u3c 0.0001). For experiment 2, all soil properties varied seasonally across two yr. (p \u3c 0.0001), except soil organic matter (SOM) (mean 4.18%, p = 0.1975). However, seasonal differences were not attributed to livestock grazing (p ≥ 0.1489) or cropping system (p ≥ 0.1884). Most soil nutrients decreased over the two-yr. experiment, with greater variability for soil nitrogen and soil pH. In experiment 3, corn grain yield was 2.2 Mg ha-1 greater for the W-C-S rotation with manure than either the W-C-S rotation without manure or the C-S rotation (p \u3c 0.0001). The W-C-S rotation with manure had greater soil aggregate stability, SOM, and active carbon with soil phosphorus and potassium concentrations also greater (P ≤ 0.0947). Soils for these three experiments had silty clay loam textures with comparatively high SOM (mean 3.61%) over the seven years of study. This likely buffered changes in crop production, and many soil properties due to livestock grazing and cropping system in the short term (\u3c 6 yr.). Consequently, soils with SOM like our experiments may respond more slowly than low SOM soils.
Advisor: Daren D. Redfear
Integrating Innovative Sensing and Ground Measurements for Forage Mass Estimation in Rye Pasture
No full textThe United States beef industry relies on forages to provide up to 80% of total lifetime dry matter intake, making accurate forage mass estimation essential for determining stocking rates, improving grazing efficiency, and supporting economic sustainability. Traditional methods to quantify forage mass, however, are time-consuming and labor-intensive. This thesis presents research efforts to achieve accurate forage mass estimation in cereal rye pasture by integrating novel sensing technologies.
Chapter 1 reviews the importance and evolution of forage mass estimation methods, from destructive clipping to indirect approaches based on canopy measurements. It then introduces remote sensing, from proximal tools to drone- and satellite-based imagery as scalable and efficient alternatives for quantifying forage availability. Practical implications of remote sensing for the beef industry are meaningful for informed grazing management and improved decision-making.
Chapter 2 evaluates two proximal sensing tools, Canopeo and the Crop Canopy Image Analyzer (CCIA), which use smartphone-based imagery to estimate forage mass. Using 400 paired forage and image samples, canopy cover derived from these tools was regressed against dried forage mass. Both tools showed strong predictive potential, with CCIA being simpler to operate and exhibited slightly superior performance (R2 = 0.78; RMSE = 405 DM kg/ha) compared with Canopeo (R2 = 0.72; RMSE = 500 DM kg/ha). Our results demonstrate that low-cost, close-range imagery can provide reliable estimates when properly calibrated.
Chapter 3 extends close-range proximal approach to spaceborne remote sensing using multispectral satellite imagery to assess forage mass across larger areas. Vegetation indices including NDVI, GNDVI and SFDVI were calculated compared with field clipping data, yielding high predictive accuracy (R2 ≈ 0.86), which outperformed the traditional indirect method of standing height (R2 = 0.44). These findings confirm the potential of satellite sensing to estimate forage mass at the pasture scale.
Collectively, this work demonstrates that proximal and satellite remote sensing can generate accurate forage mass estimates without labor demands of destructive sampling. The findings provide practical pathways for integrating sensing technologies into precision grazing systems, offering producers and scientists rapid and scalable tools to quantify forage availability, optimize stocking decisions, and support more efficient and sustainable beef production.
Advisors: Yijie Xiong and Mary E. Drewnosk
Hydrogen Embrittlement in Ni-Cr Engine Valves
No full textHydrogen energy in the form of internal combustion engines [ICEs] dates to the invention of ICEs themselves. Current efforts to reduce carbon emissions of automobiles are highly invested in hydrogen ICEs, and so investigation into the materials needed for this application is highly important. One problem is hydrogen embrittlement.
Most metals fail through ductile fracture. Hydrogen embrittlement is characterized by a transition from ductile to brittle fracture. This transition results in a lower yield stress and a lack of warning before failure in the absence of significant elastic deformation. A cruicial step in this process is the dissociation of the H2 molecule into two H atoms, which dramatically lowers the size and allows diffusion through the matrix.
This project investigated a proprietary alloy used in engine valves for hydrogen ICEs. The alloy is a majority nickel with a high chromium content and lesser amounts of alloying elements such as titanium, aluminum, etc. A protective layer of CrN is present on the combustion surface. These valves were subjected to an intense exposure regimen in a high temperature hydrogen environment and then analyzed. Analysis includes SEM-EDS, TEM imaging and ACOM, micro- and nano-hardness, and Raman spectroscopy.
Advisor: Bai Cu
Early Childhood Educators\u27 Perception of Burnout: Impact on Educator Self-Efficacy, Teacher-Child Relationships, and Children\u27s Emotional Regulation
No full textEarly childhood educators (ECE) play a critical role in the academic advancement and nurturing care provided to children in their care, a distinct difference in role and responsibilities compared to traditional K-12 schooling. Published by the Buffett Early Childhood Institute, a report pertaining to ECE turnover revealed a nearly 40% annual turnover rate. Factors ECEs previously attributed to their exit of the early childhood education field involve low wage, low self-efficacy, and dealing with challenging behaviors. While not an exhaustive list, in a field relying predominantly on routine and consistency, ECE turnover rate highlights a necessity in exploring potential indirect consequences of the educator revolving door on children. In the present study, guided by interpretative phenomenological analytic approach and Bandura’s social cognitive theory, two ECEs from a Midwest early childhood education center participated in semi-structured interviews to explore their perceptions of burnout and its impact on (1) educator self-efficacy, (2) teacher-child relationships, and (3) children’s emotional regulation. Five cross-sectional themes were identified: (1a) stressor inseparability, (1b) trainings benefit for self-regulation, (2a) educator emotional authenticity, (2b) relationship influence and (3a) children’s perception. Results first suggested that educator self-efficacy is impacted by the inseparability and compiling effect of work and life stressors and job trainings benefit for educator self-regulation, which children experience directly. Second teacher-child relationships are fostered through educators’ emotional authenticity in forms of situational empathy and true emotional expression in the classroom. In addition, valuing the parental relationship, developing a sense of ‘extended familial’ relation and the associated benefits for educators. Third, and lastly, children’s perception, rooted in Bandura’s social cognitive theory, of educator’s self-efficacy and well-being and their behavioral response, cultivating the classroom atmosphere.
Advisor: Mary Garro Zelen
Molecular Pathway Dysregulation in Chronic Liver Disease: Metabolic and Mechanotransductive Drivers of Hepatic Pathophysiology
No full textMetabolic dysfunction–associated steatotic liver disease (MASLD) represents a rapidly growing cause of chronic liver injury, yet the molecular interactions linking metabolic stress, inflammation, fibrosis, and hepatocellular carcinoma (HCC) remain incompletely defined. This thesis integrates transcriptomic analyses across multiple GEO datasets to identify coordinated metabolic, inflammatory, and mechanotransductive pathways that collectively drive disease progression.
Analysis of human liver biopsy datasets (GSE126848 and GSE89632) revealed consistent suppression of glycolysis, β-oxidation, and oxidative phosphorylation across MASLD and MASH samples, accompanied by modest compensatory TCA cycle activation. These alterations reflect impaired metabolic flexibility, mitochondrial stress, and increased ROS susceptibility. Concurrently, cytokine-network enrichment demonstrated activation of IL-6, TNF, and chemokine pathways, highlighting a metabolic–inflammatory feedback loop driven by oxidative stress and immune engagement.
To examine how these biochemical disturbances interface with liver tissue mechanics, additional datasets (GSE25097, GSE6764, GSE14323, GSE36376) were analyzed for mechanotransductive signatures. Results showed consistent upregulation of YAP1, CTGF, and CYR61, reduced expression of Hippo inhibitory regulators, and increased COL1A1, COL3A1, FN1, ACTA2, and LOX expression—indicating progressive ECM deposition, crosslinking, and stiffness. These findings support a model in which metabolic stress and inflammation promote cytoskeletal tension and YAP/TAZ activation, while YAP/TAZ-driven matrix remodeling reinforces tissue stiffness, sustaining fibrosis independent of upstream insults.
Together, these results highlight a unified mechanometabolic framework in which metabolic dysfunction, inflammatory activation, and mechanical remodeling operate as interdependent drivers of chronic liver disease. This integrated model identifies combined metabolic–mechanotransductive therapeutic strategies as promising avenues for interrupting the feedback loops that underlie fibrosis progression and HCC development.
Advisor: Srivatsan Kidamb
Use of Modified Z-Domain Peptides to Specifically Label the Constant Region of Immunoglobulin G and VEGF
No full textAntibodies are increasingly being used in medicinal therapies due to their ability to specifically bind to a target antigen. This fundamental behavior of antibodies has been used as a key component in drug development to address common problems with traditional drug molecules such as off-targeting, fast drug clearance, and low efficacy. This thesis provides some background into how antibodies can be used as potential treatments for a few diseases. Chapter 1 begins with an overview of the human immune system, and the role antibodies play within it. Then, the variety of ways in which antibodies can be used as medicinal treatments is discussed. One of these methods is antibody conjugation (also known as antibody labeling), in which a ligand can be covalently bound to an antibody. Some common issues with the current methods of antibody labeling are explored, and potential solutions are also addressed. A potential solution to some of the problems with antibody labeling is using antibodies and ligands with affinity for one another, with a reactive group added to the ligand for covalent bond formation. Chapter 2 is a study of proximity-guided labeling of peptides with antibodies and proteins based on literature examined and presented in Chapter 1. The Z-domain peptide, derived from the B domain of Staphylococcus aureus protein A, has affinity with IgG at the Fc region, making it a good candidate for testing the substitution of a reactive group for labeling. An additional protein system, Z-VEGF and VEGF, were also analyzed in a similar matter. While there were some successes when using proximity-guided labeling for these two systems, there still remains some uncertainty regarding the consistency of results based on the experimental method and what can be observed.
Advisor: James W. Checc