All Faculty Deposits

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https://hdl.handle.net/10919/70873

The "All Faculty Deposits" collection contains works deposited by faculty and appointed delegates from the Elements (EFARs) system. For help with Elements, see Frequently Asked Questions on the Provost's website. In general, items can only be deposited if the item is a scholarly article that is covered by Virginia Tech's open access policy, or the item is openly licensed or in the public domain, or the item is permitted to be posted online under the journal/publisher policy, or the depositor owns the copyright. See Right to Deposit on the VTechWorks Help page. If you have questions email us at vtechworks@vt.edu.

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Now showing 1 - 20 of 6081

Impact of Post-Traumatic Epilepsy on Mental Health and Multidimensional Outcome and Quality of Life: An NIDILRR TBIMS Study
Awan, Nabil; Weppner, Justin; Kumar, Raj; Juengst, Shannon; Dams-O'Connor, Kristen; Sevigny, Mitch; Zafonte, Ross; Walker, William; Szaflarski, Jerzy; Wagner, Amy (Mary Ann Liebert, 2025-01-06)
Traumatic brain injury (TBI) and subsequent post-traumatic epilepsy (PTE) often impair daily activities and mental health (MH), which contribute to long-term TBI-related disability. PTE also affects driving capacity, which impacts functional independence, community participation, and satisfaction with life (SWL). However, studies evaluating the collective impact of PTE on multidimensional outcomes are lacking. Thus, we generated a model to investigate how PTE after moderate-to-severe (ms)TBI affects TBI-associated impairments, limits activities and participation, and influences SWL. Of 5108 participants with msTBI enrolled into the National Institute for Disability, Independent Living, and Rehabilitation Research TBI Model Systems between 2010 and 2018 and with seizure-event data available at year-1 post-TBI, 1214 had complete outcome data and 1003 had complete covariate data used for analysis. We constructed a conceptual framework illustrating hypothesized interrelationships between year-1 PTE, driving status, functional independence measure (FIM), depression and anxiety, as well as year-2 participation, and SWL. We performed univariate and multivariable linear and logistic regressions. A covariate-adjusted structural equation model (SEM), using the lavaan package (R), assessed the conceptual framework’s suitability in establishing PTE links with outcomes 1-2 years post-injury. Multiple parameters were evaluated to assess SEM fit. Year-1 PTE was correlated with year-1 FIM motor (standardized coefficient, βstd = −0.112, p = 0.007) and showed a trend level association with year-1 FIM cognition (βstd = −0.070, p = 0.079). Individuals with year-1 PTE were less likely to drive independently at year 1 (βstd = −0.148, p < 0.001). In addition, FIM motor (βstd = 0.323, p < 0.001), FIM cognition (βstd = 0.181, p = 0.012), and anxiety (βstd = −0.135, p = 0.024) influenced driving status. FIM cognition was associated with year-1 depression (βstd = 0.386, p < 0.001) and year-1 anxiety (βstd = 0.396, p < 0.001), whereas year-1 FIM motor (βstd = 0.186, p = 0.003), depression (βstd = −0.322, p = 0.011), and driving status (βstd = 0.233, p < 0.001) directly affected year-2 objective life participation metrics. Moreover, year-1 depression (βstd = −0.382, p = 0.001) and year-2 participation (βstd = 0.160, p < 0.001) had direct effects on year-2 SWL. SWL was influenced indirectly by year-1 variables, including functional impairment, anxiety, and driving status—factors that impacted year-2 participation directly or indirectly, and consequently year-2 SWL, forming a complex relationship with year-1 PTE. A sensitivity analysis SEM showed that the number of MH disorders was associated with participation and SWL (p < 0.001), and this combined MH variable was directly related to driving status (p < 0.02). Developing PTE during year-1 after msTBI affects multiple aspects of life. PTE effects extend to motor and cognitive abilities, driving capabilities, and indirectly, to life participation and overall SWL. The implications underscore the crucial need for effective PTE management strategies during the first year post-TBI to minimize the adverse impact on factors influencing multidimensional year-2 participation and SWL outcomes. Addressing transportation barriers is warranted to enhance the well-being of those with PTE and msTBI, emphasizing a holistic approach. Further research is recommended for SEM validation studies, including testing causal inference pathways that might inform future prevention and treatment trials.
Spatial and temporal dynamics of Collembola (Isotomiella minor) and plant pathogenic fungi (Rhizoctonia solani) interactions
Jernigan, Ashley B.; Kao-Kniffin, Jenny; Pethybridge, Sarah; Wickings, Kyle (Elsevier, 2024-09)
The mechanistic and spatial dynamics of microarthropod-plant pathogen interactions remain understudied, despite the importance of these interactions in plant disease control. We conducted three complementary laboratory experiments using the plant-pathogenic fungus, Rhizoctonia solani, and the Collembola Isotomiella minor. The dominant mechanism (consumption vs. dispersal) of these interactions was investigated over 5 days in a controlled environment. The dominant mechanism observed was consumption, with I. minor decreasing R. solani growth by up to 58 %. There was no evidence of pathogen dispersal, however, there was potential for R. solani dispersal by I. minor as there were viable pathogen structures on the cuticle and in the frass. I. minor effects on R. solani mycelial growth rate were then determined using race tubes over 14 days. I. minor decreased R. solani mycelial growth rate by up to 23 %. Soil environment effects were explored over 5 days in a controlled environment using mineral substrate to mimic a 3-dimensional soil environment, both with and without organic matter (alfalfa) additions. In the soil without organic matter, the high I. minor abundances decreased R. solani growth compared to the low and no I. minor abundances by 23 % and 22 % respectively. In the soil with organic matter, I. minor did not affect R. solani growth. These findings suggest that organic matter in soils may be diminishing collembolan control of plant pathogens in field settings.
Microarthropods improve oat nutritional quality and mediate fertilizer effects on soil biological activity
Jernigan, Ashley B.; Kao-Kniffin, Jenny; Pethybridge, Sarah; Wickings, Kyle (Wiley, 2024-05-27)
Soil biological processes are important drivers of crop productivity in agroecosystems. Soil microarthropods play key roles in nutrient cycling and plant nutrient acquisition, though little is known about how these effects manifest in crop production under different organic fertilizer amendments. We explored the interactive effects of microarthropods and fertilizers on crop productivity in two greenhouse experiments: experiment one involved a single Collembola species, and experiment two involved diverse microarthropod communities. Oats were grown as a model crop in both experiments under one of three initial fauna abundance levels (none, low, and high). In both experiments, four organic fertilization treatments were compared: alfalfa green manure, Kreher's Poultry Litter Compost, Chilean nitrate, and a nonamended control. Oat growth and development were evaluated weekly. During each experiment, 48 pots were selected randomly for destructive harvest at two separate times to mimic forage and grain harvest stages. At each harvest, multiple soil metrics (microarthropods, microbial biomass, microbial enzymes, and soil carbon and nitrogen) and plant metrics (biomass, reproduction, and tissue carbon and nitrogen content) were evaluated. Our findings indicated that microarthropods, both single species and diverse communities, stimulated nitrogen cycling and enhanced crop nutrient status. As microarthropod abundance and diversity increased, microarthropods exerted more effects on soil microbial activity. The effects of the microarthropods enhance the breakdown of fertilizers, ultimately making fertilizer choice less important for soil processes and plant nutrient availability. Our findings suggest that microarthropods drove oat production yields primarily through their effects on soil biological processes.
Maximizing the role of teaching assistants (TAs) to match signature pedagogies in leadership education
Hastings, Lindsay J.; Sunderman, Hannah M.; Forsythe, Kaitlyn; Knopik, Nick (Emerald, 2024-03-11)
Purpose: The purpose of the current application paper is to integrate previous literature with recent results from practitioners on effective practices for utilizing small groups in the leadership classroom. Design/methodology/approach: We use these integrated findings to innovate practice on maximizing the role of undergraduate teaching assistants (UTAs) by matching their tasks to signature pedagogies in leadership education. Findings: The integrated findings revealed three practice themes: (1) match UTAs to pedagogical approach, (2) create small groups by design and (3) providing training and reflection practice for UTAs. Originality/value: In sum, leadership education can and should challenge historical practices in higher education whereby UTAs are used purely for grading and course logistics management.
Developmental Relationships That Encourage Generativity
Hastings, Lindsay J.; Sunderman, Hannah M.; Knopik, Nick (Wiley, 2024-05-21)
Early leader and leadership development experiences that develop generativity and therefore social responsibility will become increasingly imperative in preparing a young workforce to shoulder the burden of a substantial leadership transfer in the wake of Baby Boomer retirements. While generativity is considered a midlife construct, recent and emergent research is documenting an association between developmental relationships, such as mentoring, coaching, and advising, and generativity in young adults. The current article highlights the recent research and addresses its implications for leadership practitioners, scholars, and educators. The article concludes with a discourse on future research directions that considers the nuances of particular methodological approaches that will be needed to understand how developmental relationships encourage generativity over time.
Leader(ship) identity development and meaning making: A scoping review
Sunderman, Hannah; Orsini, Jonathan (WILEY, 2022)
Despite a growing body of scholarship on leader and leadership (i.e., leader[ship]) identity development (LID), there has been surprisingly little systematic attention devoted to the connection between LID and meaning making, which is notable because meaning making has been regarded as foundational to the LID process. Accordingly, the current scoping review explores the scholarship and key characteristics at the intersection of LID and meaning making. Specifically, the year of publication, research method and design, country of participants, and theories central to author justification are analyzed. After sharing the results, contributions, and implications for the constructs of LID and meaning making are outlined, with attention given to theoretical and methodological areas for future research. Finally, an integrated constructivist model of LID is proposed that urges leadership scholars and practitioners to incorporate developmental, identity, learning, and meaning-making theories into their discussions of LID.
Intercultural mentoring: enhancing cultural competence through intergroup contact and experiential learning
Adebayo, Bolanle Oyindamola; Sunderman, Hannah M. (EMERALD GROUP PUBLISHING LTD, 2024-01-01)
Purpose: To maximize the benefits of intercultural mentoring relationships, which are increasing in today’s diverse higher education environment, the current article conceptualizes the connection between intercultural mentoring and cultural competence among mentors and mentees as a learning process. Design/methodology/approach: The conceptual paper discusses the nuanced aspects of intercultural mentoring. Ultimately, the current article presents a framework for a bidirectional relationship between intercultural mentoring and cultural competence through experiential learning theory and intergroup contact theory, resulting in implications for practitioners and actionable research directions. Findings: The article highlights the interplay and interdependence of cultural competence and intercultural mentoring through experiential learning and intergroup contact theory. Cultural competence influences the quality of intercultural mentoring relationships. Conversely, intercultural mentoring relationships can develop cultural competence in mentors and mentees through experiential learning, producing positive intergroup contact behaviors. Findings suggest the need for active learning and unlearning among mentors and mentees in intercultural mentoring relationships to maximize developmental outcomes (e.g. cultural competence). Originality/value: The proposed framework emphasizes that (1) the possession of cultural competence is a critical success factor for intercultural mentoring relationships, (2) the development of cultural competence is an outcome of successful intercultural mentoring relationships, and (3) intercultural mentoring relationships should be regarded as experiential learning platforms that can produce positive intercultural traits such as cultural competence.
Establishing an Agenda for Public Budgeting and Finance Research
McDonald, Bruce, III; Davis, Stephanie D. (2024-04-01)
Public budgeting and finance is a discipline that encompasses communities of research and practice. Too often, however, these communities fail to engage each other, instead choosing to operate independently. The result is that the research being conducted fails to address the questions of the day and our governments’ challenges. In this article, we come together as a community of academics and practitioners to establish an agenda for where future research should be conducted. This agenda aims to align the research being undertaken within the academic community with the needs of those working in the community of practice. After establishing ten areas where research is needed, we followed a ranked-choice voting process to establish a prioritization for them. Based on the outcome of this process, the two primary areas where research is currently needed most are the fiscal health of our governments and the implementation of social equity budgeting.
Deepening Interlocal Partnerships: The Case of Revenue-sharing Infrastructure Agreements
Davis, Stephanie D.; Gough, Meghan Z. (SAGE Publications, 2020-06-19)
Rotational magic conditions for ultracold molecules in the presence of Raman and Rayleigh scattering
Kotochigova, Svetlana; Guan, Qingze; Tiesinga, Eite; Scarola, Vito W.; DeMarco, Brian; Gadway, Bryce (IOP Publishing, 2024-06-20)
Molecules have vibrational, rotational, spin-orbit and hyperfine degrees of freedom or quantum states, each of which responds in a unique fashion to external electromagnetic radiation. The control over superpositions of these quantum states is key to coherent manipulation of molecules. For example, the better the coherence time the longer quantum simulations can last. The important quantity for controlling an ultracold molecule with laser light is its complex-valued molecular dynamic polarizability. Its real part determines the tweezer or trapping potential as felt by the molecule, while its imaginary part limits the coherence time. Here, our study shows that efficient trapping of a molecule in its vibrational ground state can be achieved by selecting a laser frequency with a detuning on the order of tens of GHz relative to an electric-dipole-forbidden molecular transition. Close proximity to this nearly forbidden transition allows to create a sufficiently deep trapping potential for multiple rotational states without sacrificing coherence times among these states from Raman and Rayleigh scattering. In fact, we demonstrate that magic trapping conditions for multiple rotational states of the ultracold 23Na87Rb polar molecule can be created.
Quantum simulation costs for Suzuki-Trotter decomposition of quantum many-body lattice models
Myers, Nathan M.; Scott, Ryan; Park, Kwon; Scarola, Vito W. (American Physical Society, 2023-06-28)
Quantum computers offer the potential to efficiently simulate the dynamics of quantum systems, a task whose difficulty scales exponentially with system size on classical devices. To assess the potential for near-term quantum computers to simulate many-body systems we develop a formalism to straightforwardly compute bounds on the number of Trotter steps needed to accurately simulate the time evolution of fermionic lattice models based on the first-order commutator scaling. We apply this formalism to two closely related many-body models prominent in condensed matter physics, the Hubbard and t-J models. We find that, while a naive comparison of the Trotter depth first seems to favor the Hubbard model, careful consideration of the model parameters and the allowable error for accurate simulation leads to a substantial advantage in favor of the t-J model. These results and formalism set the stage for significant improvements in quantum simulation costs.
CLIR Postdoctoral Fellowship in Community Data for the Rematriation Project: Summary Report
Yunes, Erin; Long, Kara (2024-08-19)
The CLIR Postdoctoral Fellowship in Community Data at the Virginia Tech University Libraries (VTUL) was a collaborative initiative designed to help bridge academic resources and community-led projects. The fellowship focused on supporting the Rematriation project through collaboration among scholars and staff from the VT University Libraries and Department of English and community members. A key directive was to work with an Inuit-led interdisciplinary team in creating a digital archive that centers Indigenous knowledges and perspectives. This report provides an overview of the fellowship's objectives, methodologies, key activities, and outcomes, emphasizing the collaborative efforts and innovative approaches that shaped this work.
Constructing Consistent Comprehensive Searches in Large Engineering Databases—Tips and Recommendations for Literature Reviews
Over, Sarah; Comer, C. Cozette (ASEE Conferences, 2024-06)
Engineering and STEM librarians and researchers regularly use a number of disciplinary databases for finding literature. For evidence synthesis (ES) research projects, knowing database capabilities and how to most effectively search each database is critical. The complex, often comprehensive search strategies necessary for ES reviews can require use of “advanced” search options and controlled vocabulary/index terms. However, the functionality of search interfaces used to access databases varies widely. Thus, searchers must expend more time and effort to translate searches consistently, as each database has different features and limitations. This article will cover major engineering databases used in comprehensive searches, including Engineering Village and more. Each database's search implementation will be explained using an example search on hearing disabilities in computing education, which was developed for a scoping review by the authors in collaboration with a faculty member and a graduate student from the Computer Science department at Virginia Tech. Aspects of advanced searching such as truncation, proximity searching, exact phrases, and controlled vocabulary/index terms will also be highlighted. Overall, these databases require more research into how to construct searches compared to some interdisciplinary databases, but still have their place in finding quality engineering research efficiently.
Multi-Year Soil Response to Conservation Management in the Virginia Coastal Plain
Nicholakos, Sophie A.; Frame, W. Hunter; Reiter, Mark S.; Stewart, Ryan D. (Elsevier, 2025-01)
In the coastal plain region of the United States, conservation agriculture practices are being implemented to improve soil health, minimize environmental impacts, and improve farm profitability. Common practices include cover cropping and conservation tillage using strip tillage, minimal tillage, or no tillage. However, the soil response to specific combinations of conservation tillage and cover crop rotations remains poorly quantified. The objective of this research was to evaluate changes in soil properties from different combinations of conservation management. Four tillage systems – conventional, strip, minimal, and no tillage – and three winter cover rotations – fallow, winter cash crop, and high-biomass cover crop – were tested in a split-plot design. Bulk density, depth to a root-restrictive layer, soil carbon concentration, soil carbon stock, field-saturated hydraulic conductivity, and yield were measured over a seven-year period. Bulk density and field-saturated hydraulic conductivity showed greater temporal variation in the strip tillage and conventional tillage practices. Depth to root-restrictive layer was consistently highest in the strip and minimal tillage treatments, which both included implements designed to alleviate subsoil compaction. Treatments that combined conservation tillage with a winter cover (i.e., cash crops or high-biomass cover crops) had greater increases in soil carbon concentrations and carbon stock. Summer cash crop yield was significantly increased following the high-biomass cover crop treatment in 2 out of the 7 years. Altogether, soil carbon showed a more consistent response to conservation management than the other soil properties, which tended to show greater variability based on the time since disturbance (e.g., tillage). Conservation management practices therefore need to be consistently applied for multiple years in order to improve soil properties such as bulk density and saturated hydraulic conductivity.
Modeling water infiltration into soil under fractional wettability conditions
Di Prima, Simone; Stewart, Ryan D.; Abou Najm, Majdi R.; Yilmaz, Deniz; Comegna, Alessandro; Lassabatere, Laurent (Elsevier, 2025-02-01)
The heterogeneous distribution of water-repellent materials at the soil surface causes a phenomenon known as fractional wettability. This condition frequently triggers destabilization of the wetting front during water infiltration, resulting in the formation of fingered bypass flow. However, few analytical tools exist to understand and model this behavior. Moreover, existing infiltration models fail to fit certain infiltration curves that exist in experimental data. For these reasons, we introduce a novel infiltration model to simulate water infiltration under fractional wettable conditions. We conceptualize the soil surface as a composite of two distinct portions: a water-repellent fraction, where hydrophobic effects impede water infiltration, and a wettable fraction, where capillarity and gravity are the dominant forces controlling the process. The new model was validated using a dataset comprising infiltration data from 60 field measurements. Additionally, validation was performed using 660 analytically generated infiltration curves from six synthetic soils with varying textures. This innovative approach enabled us to account for the combined influence of these two fractions and to enhance the interpretation of infiltration curves with mixed shapes, which other common methods are unable to reproduce.
COVID-19: Financial Impacts on Virginia's Local Governments: A report to support local government decision making
Davis, Stephanie D. (2020-06-01)
How small communities can leverage strategic planning for ARPA funds
Davis, Stephanie D. (2022-03-01)
Preparing the next generation of managers: 10th Anniversary of the Graduate Certificate in Local Government Management
Davis, Stephanie D. (2018-04-01)
Defining Local Government Financial Capacity in Small Towns: Challenges and Opportunities
Davis, Stephanie D. (2024-11-23)
The purpose of the paper is to investigate the financial condition of towns in Virginia. An article in the Municipal Finance Journal (published by the author in December 2023) examined the financial impacts of the pandemic on cities, counties, and towns in Virginia. The study found that the pandemic resulted in more significant impacts on towns as opposed to cities and counties. This paper continues research into the financial condition of towns in Virginia. This study uses both qualitative and quantitative research methods to determine the town managers' perspectives on financial capacity and to quantify financial condition for each town. The study population includes 35 of the 190 towns in Virginia. Per State Code, local governments with a population of more than 3,500 must submit an annual comprehensive financial report annually to the Auditor of Public Accounts, however, only 35 of the 190 towns meet Virginia State Code requirements for annual comprehensive financial report submissions. Organizational capacity is defined as human, financial and leadership factors. Human capacity is operationalized through the staff expertise, staff time constraints and staff experience in the performance of a local government organization. Financial capacity are the resources available to fund the government service and organization. Leadership capacity refers to the level of support from elected officials including Town council members and mayors. One goal of the study is to understand how town managers view financial capacity and the study seeks to operationalize this concept for locals governments. Operationalizing financial capacity facilitates local government manager's understanding of how revenues and expenditures should be budgeted, planned and utilized in order to achieve the goals of the organization. Next, quantitative, audited financial data will be used to understand the financial condition of the town. The use of the Comparative reports of Local Government Revenues and Expenditures published by the Auditor of Public Accounts of Virginia(APA) serves as the data collection process to evaluate financial condition using established financial ratios by the APA. Reconciliation of perceived financial capacity by managers and actual financial data will be analyzed to determine what gaps are demonstrated by the perceptions of managers on financial capacity and the actual financial condition of the local government. The results of the study will serve as recommendations on financial resiliency for towns in Virginia which may be applicable to towns throughout the United States.
Physiological responses of pepper (Capsicum annum) to combined ozone and pathogen stress
Modelski, Collin; Potnis, Neha; Sanz-Saez, Alvaro; Leisner, Courtney P. (Wiley, 2024-06-24)
Tropospheric ozone [O3] is a secondary air pollutant formed from the photochemical oxidation of volatile organic compounds in the presence of nitrogen oxides, and it is one of the most damaging air pollutants to crops. O3 entry into the plant generates reactive oxygen species leading to cellular damage and oxidative stress, leading to decreased primary production and yield. Increased O3 exposure has also been shown to have secondary impacts on plants by altering the incidence and response to plant pathogens. We used the Capsicum annum (pepper)-Xanthomonas perforans pathosystem to investigate the impact of elevated O3 (eO3) on plants with and without exposure to Xanthomonas, using a disease-susceptible and disease-resistant pepper cultivar. Gas exchange measurements revealed decreases in diurnal photosynthetic rate (A′) and stomatal conductance ((Formula presented.)), and maximum rate of electron transport (Jmax) in the disease-resistant cultivar, but no decrease in the disease-susceptible cultivar in eO3, regardless of Xanthomonas presence. Maximum rates of carboxylation (Vc,max), midday A and gs rates at the middle canopy, and decreases in aboveground biomass were negatively affected by eO3 in both cultivars. We also observed a decrease in stomatal sluggishness as measured through the Ball–Berry–Woodrow model in all treatments in the disease-resistant cultivar. We hypothesize that the mechanism conferring disease resistance to Xanthomonas in pepper also renders the plant less tolerant to eO3 stress through changes in stomatal responsiveness. Findings from this study help expand our understanding of the trade-off of disease resistance with abiotic stresses imposed by future climate change.

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