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 40 freely available and openly licensed textbooks are among our most downloaded items.
Communities in VTechWorks
Select a community to browse its collections.
Recent Submissions
Inhibition, Synapses, and Spike-Timing: Identification and disruption of pyramidal cell-interneuron interactions in SPW-Rs.
Gilbert, Earl Thomas (Virginia Tech, 2024-06-25)
The neural circuitry responsible for memory consists of complex components with dynamic interactions. In hippocampal area CA1, interactions between excitatory pyramidal cells and inhibitory interneurons shape ensemble activity which encodes sequential experience. An extremely diverse set of inhibitory interneurons, with variation in gene expression, synaptic targeting, state-dependent activity, and connectivity, contribute substantially to circuit activity, such as theta and sharp wave-ripple oscillations. The precise roles of each interneuron group is not well understood, though characterization of their activity reveals mechanisms underlying hippocampal circuit computation. In this dissertation, I aim to identify and disrupt interactions between pyramidal cells and local interneurons to clarify their role in shaping cell assembly activity. We characterized axo-axonic cell activity in sharp wave-ripples, and compared their control of pyramidal cell activity and ripple events to parvalbumin expressing neurons. We identified pyramidal cell-interneuron interactions during ripples, suggesting they serve as lateral inhibitors between cell assemblies. We additionally developed and implemented a novel neural device to explore the role of cannabinoid disruption of hippocampal oscillations and organization of assemblies in vivo in awake animals. We demonstrate that cannabinoid receptor type 1 within CA1 is responsible for suppression of theta and SPW-Rs. We also found that cannabinoid activation within CA1 circuitry, regardless of muted input from CA3, was sufficient to disrupt sharp wave-ripples, likely through interference of pyramidal cell-interneuron interactions. The work in this dissertation provides insight suggesting that interneuron activity must be studied at the spiking timescale to characterize their control over cell assembly activity.
Dynamics and Electrostatics of Membrane Proteins using Polarizable Molecular Dynamics Simulations
Montgomery, Julia Mae (Virginia Tech, 2024-06-25)
Membrane proteins are critical to many biological processes, including molecular transport, signal transduction, and cellular interactions. Through the use of molecular dynamics (MD) simulations, we are able to model this environment at an atomistic scale. However, traditionally used nonpolarizable force fields (FF) are thought to model the unique dielectric gradient posed by the lipid environment with a limited accuracy due to the mean field approximation of charge. Advancements in polarizable FFs and computing efficiency has enabled the explicit modeling of polarization responses and charge distribution, enabling a deeper understanding of the electrostatics driving these processes. Through the use of the Drude FF, we study three specific model systems to understand where explicit polarization is important in describing membranes and membrane proteins. These studies sought to answer the questions: (1) How does explicit electronic polarization impact small molecule permeation and localization preference?, (2) What electrostatic interactions underlie membrane protein secondary structure?, and (3) How do conformational changes propagate between microswitches in G-Protein Coupled Receptors? In this work, we show small molecule dipole moments changing as a function of localization in the bilayer. Additionally, we show differences in the free energy surfaces of permeation for aromatic, polar, and negatively charged species reliant upon force field used. For secondary structure, we showed key interactions which aided to stabilize model helices in bilayers. Finally, we showed potential inductive effects of key microswitch residues underlying prototypical G-Protein coupled receptor activation. This dissertation has helped to show the importance of including explicit polarization in membrane protein systems, especially when considering interactions at the interface and modeling species with charge. This work enables a refined view of the electrostatics occurring in membranes and membrane protein systems, and in the future, can be used as a basis for methodologies in computer aided drug design efforts.
Myco-scapes: Multispecies Entanglements in Artmaking
Thornton, Eva Marie (Virginia Tech, 2024-06-25)
Myco-scapes: Multispecies Entanglements in Artmaking is a body of ephemeral fiber sculptures. These weavings and digital fabrications are the result of collaborations with dynamic materials and other species, primarily fungi. The artworks (or artifacts) of the artist's material intra-actions explore the possibilities, challenges, and ethics of multispecies collaboration. Furthermore, in its ephemerality, Myco-scapes responds to the preventative conservation practices employed by art museums. Not only do these sculptures embody the fleeting nature of material entanglements, but they also challenge the capitalist structure of art collecting through their impermanence.
The written thesis describes the artist's studio practice by exploring three primary influences: mycelium (the root-like structures of mushrooms), entanglements (the complex interwoven structures in which we exist), and preventative conservation (art-handling protocol designed to preserve artifacts).
Investigating Student Perceptions of Equitable Grading Practices
Shukla, Anmol (Virginia Tech, 2024-06-25)
Grading is one of the key components of modern pedagogy. Grades are primarily meant to be a method of communication, which is initiated by the owners of the pedagogy (instructors, school, etc.) and are received by various parties such as students: as feedback on their learning outcomes, parents, potential employers, other institutions, etc. However, traditional grading practices in wide use across institutions globally suffer from many problems and can prove to be a hindrance to students achieving their learning outcomes.
Many of these practices do not have a backing in education and social research and suffer from various problems such as inherent bias, rewarding of behavior over skill or knowledge, increasing student anxiety, etc. In contrast, EGPs have been backed in research, follow a more open assessment method and have been shown to induce increased learning. Thus, to mitigate some of these problems, we employ Equitable Grading Practices (EGPs) in an introductory CS-1 course at Virginia Tech for the Fall 2023 and Spring 2024 semesters.
In this thesis, we introduce these practices and evaluate student perceptions of them thereafter to answer research questions so that we may be able to refine these practices. We gather student experiences primarily through two instruments: a survey and one-on-one interviews. We describe these in detail and evaluate them through the use of statistics as well grounded theory analysis to be able to extract student perceptions of these grading practices.
AeroVolt Shading: Wind-Piezo Kinetic shading facade
Khojasteh far, Faraz (Virginia Tech, 2024-06-25)
This research delves into the feasibility and effectiveness of utilizing wind-powered shading systems in architectural design to enhance energy efficiency and promote environmental sustainability. With an ever increasing demand for energy in commercial buildings, particularly in heating, cooling, and lighting, innovative solutions are crucial in addressing these challenges. The proposed solution centers on dynamic shading systems that adjust autonomously to environmental factors, thanks to advancements in construction and information technologies. Piezoelectric wind harnessing devices are at the heart of this investigation, powering kinetic shading systems that offer a renewable and eco-friendly alternative to traditional energy sources. However, implementing such systems presents technical challenges such as device optimization, compatibility with dynamic movement, and reliability in real-world applications. Through empirical research and experimentation, these challenges are comprehensively explored and addressed. The study seeks to assess the practicality and effectiveness of wind-powered shading systems in reducing energy consumption, improving thermal comfort, and enhancing overall building performance. By considering factors such as architectural integration, heat, light management, and adaptability to environmental conditions, the research aims to contribute to the advancement of sustainable building practices. Ultimately, the findings provide valuable insights into the potential of wind-powered shading systems to mitigate energy usage and promote environmental stewardship in architectural design.