VTechWorks
VTechWorks provides global access to Virginia Tech scholarship, including journal articles, books, theses, dissertations, conference papers, slide presentations, technical reports, working papers, administrative documents, videos, images, and more by faculty, students, and staff. Faculty can deposit items to VTechWorks from Elements, including journal articles covered by the University open access policy. Email vtechworks@vt.edu for help.
Open Access Policy
Virginia Tech's open access policy enables researchers to deposit the accepted version of scholarly articles with no embargo.
Theses and Dissertations
Virginia Tech was first in the world to require ETDs in 1997, and continues to add scans of older theses and dissertations.
Open Textbooks
More than 50 freely available and openly licensed textbooks are among our most downloaded items.
Communities in VTechWorks
Select a community to browse its collections.
Recent Submissions
State-of-the-Art Analysis of U.S. Flight Event and Surveillance Data Coverage and Future Research Directions
Hotle, Susan; Titlow, Kyle; Hashemipour, Mehdi; Strocko, Ed (SAGE Publications, 2025-11-24)
The Automatic Dependent Surveillance-Broadcast mandate, along with advances in government and third-party flight tracking systems, has allowed researchers to analyze aspects of aviation operations that were not possible beforehand. The purpose of this study is to provide: 1) a summary of flight event data available to the public, 2) a comparison of application programming interface surveillance data available in the U.S., and 3) an evaluation of flight coverage across the data sources. This analysis considers the FAA’s Aviation System Performance Metrics, the Bureau of Transportation Statistics’ Airline Service Quality Performance System, the Official Airline Guide’s On-Time Performance Flight dataset, the FAA’s System Wide Information Management (SWIM), and the OpenSky Network (OSN). It reports the spatial and market segment (i.e., commercial, general aviation, air cargo) coverage, helping researchers identify the appropriate dataset for their studies. This study found that OSN has worldwide coverage of enroute flights, with limited airport surface movement. FAA’s SWIM contains several surveillance datasets, two enroute (only one includes Alaska and Hawaii), and one airport surface datasets. Combining sources allows one source to overcome a spatial limitation of another to generate a complete trajectory. The flight counts by source are reported with a discussion of their discrepancies, where surveillance sources do not capture all flights from the flight event datasets and vice versa. Therefore, surveillance should be considered supplemental and not a replacement for measuring flight counts. This paper then discusses future research directions, given surveillance availability.
Social, mobility and contact networks in shaping health behaviours and infectious disease dynamics: a scoping review
Cheng, Zhifeng; Ruktanonchai, Nick W.; Wesolowski, Amy; Pei, Sen; Wang, Jianghao; Cockings, Samantha; Tatem, Andrew J.; Lai, Shengjie (2025-12-03)
Background: The interconnectedness of human society in this modern world can transform localised outbreaks into global pandemics, underscoring the pivotal roles of social, mobility and contact networks in shaping infectious disease dynamics. Although these networks share analogous contagion principles, they are often studied in isolation, hindering the incorporation of behavioural, informational, and epidemiological processes into disease models. This review synthesises current research on the interplay between social, mobility and contact networks in health behaviour contagion and infectious disease transmission.
Methods: We searched Web-of-Science and PubMed from January 2000 to June 2025 for research on health behaviour contagion and information dissemination in social networks, pathogen spread through mobility and contact networks, and their joint impacts on epidemic dynamics. This was first done by a preliminary literature screening based on predefined criteria. With potentially relevant publications retained, we performed keyword co-occurrence network analysis to identify the most common themes in studies. The results guide us to narrow down the reviewing scope to the social, mobility and contact network impacts on informational, behavioural, and epidemiological dynamics. We then further identified and reviewed the literature on these multidimensional network influences.
Results: Our review finds that each network type plays a distinct yet interconnected role in shaping behaviours and disease dynamics. Social networks, comprising both online and offline interpersonal relationships, facilitate the dissemination of health information and influence behavioural responses to public health interventions. Concurrently, mobility and contact networks govern the spatiotemporal pathways of pathogen transmission, as demonstrated in recent pandemics. While traditional population-level models often overlook individual discrepancies and social network effects, significant efforts have been made through developing individual-level simulation-based models that integrate behavioural dynamics. With emerging new data sources and advanced computational techniques, two promising approaches—multiplex network analysis and generative agent-based modelling—offer frameworks for integrating the complex interdependencies among social, mobility and contact networks into epidemic dynamics estimation.
Conclusions: This review highlights the theoretical and methodological advances in network-based infectious disease modelling and identifies critical knowledge and research gaps. Future research should prioritise integrating multi-source behavioural and spatial data, unifying modelling strategies, and developing scalable approaches for incorporating multilayer network data. The integrated approach will strengthen public health strategies, enabling equitable and effective interventions against emerging infections.
Branched-chain amino acids in muscle growth: mechanisms, physiological functions, and applications
Xu, Shuyong; Zhao, Guangyong; Hanigan, Mark D.; Cantalapiedra-Hijar, Gonzalo; Li, Mengmeng (2025-12-03)
Skeletal muscle accounts for approximately 40% of body mass and 50%–75% of whole-body protein, playing a central role in meat production and quality. Efficient protein synthesis in skeletal muscle relies on an adequate supply of nutrient substrates and a balanced amino acid profile. Branched-chain amino acids (BCAA), including leucine (Leu), isoleucine (Ile), and valine (Val), are the most abundant essential amino acids in skeletal muscle and contribute to both protein synthesis and oxidative energy production. Additionally, BCAA function as signaling molecules that regulate gene expression and protein phosphorylation cascades, which significantly influence physiological processes, such as protein synthesis and degradation, glucose and lipid metabolism, and cell apoptosis and autophagy. These processes are primarily mediated through the PI3K/AKT/AMPK/mTOR signaling pathways. This review summarizes BCAA transporters and catabolic metabolism, their role as signaling molecules in regulating protein metabolism and glucose and lipid equilibrium, and applications in animal production. These findings offer both theoretical insights and practical guidelines for the precise regulation of feed efficiency and production performance through tailored dietary BCAA supplementations. Graphical Abstract
Insights from the Agriculture Workforce Training for Collaborative Leadership Project
Kaufman, Eric K. (2025-12-05)
Join the Agriculture & Extension Leadership Focus Area Network for an engaging session with Dr. Eric Kaufman from Virginia Tech, who will share insights from the Agriculture Workforce Training for Collaborative Leadership (AWT4CL) project. This initiative leverages digital badging to recognize and assess leadership competencies, equipping students with verifiable credentials that strengthen their employability and career readiness.
Dr. Kaufman will provide an overview of the AWT4CL digital badging framework, lessons learned from implementation, and practical tips for writing grants and building programs that integrate digital credentials into agricultural and leadership education.
Virginia Cooperative Extension 2026 Faculty Leadership Development Program Preview
Seibel, Megan M.; Kaufman, Eric K. (2025-12-05)
The VCE Faculty Leadership Development Program (FLDP) is a dynamic professional development opportunity designed to enhance VCE faculty leadership competencies. Goals of FLDP are to increase programmatic, community, administrative and/or volunteer leadership effectiveness. Participants graduate from the program better prepared for future leadership opportunities. The FLDP leads, Eric Kaufman & Megan Seibel, will share more details about the program & the positive impacts/outcomes of those who have participated in previous years. This session is just in time before applications are made available to participate in the 2026 FLDP cohort.