All Faculty Deposits

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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 6266

Evaluation of a Participatory Action Planning Project to Address Opioid Misuse: Breaking Down Barriers Through Partnership Processes
Rafie, Carlin; Zimmerman, Emily; Reed, Dawn; Hargrove, Angelina (UTS ePress, 2024-12-19)
Community based participatory research and participatory action research are increasingly being used to engage communities in addressing social and health disparities. There is a need to develop broadly applicable evaluation methods that can be used across participatory project environments to identify the processes critical for addressing complex public health issues, as well as the productiveness of community research partnerships. We present a case study of a community participatory project conducted over three years and our evaluation approach. We used the Community Based Participatory Research Conceptual Model as the framework for the evaluation surveys (n=9) and interviews (n=7) with project participants, querying perspectives on the four model domains: community context, partnership processes, intervention and research and outcomes. In addition, we conducted a Ripple Effects Mapping (REM) exercise with ten community members to determine the broader impacts of the project on the community. This mixed-methods approach permitted us to confirm findings from quantitative surveys with qualitative findings from interviews and the REM. Key processes identified as facilitators to a productive partnership and positive outcomes include a context of trust, effective implementation of processes that establish equitable partner relationships and partnership synergy, a clearly defined focus for the partnership and a structured participatory research method that helped break down silos and mobilise the community for action. Our project evaluation approach, combining the CBPR model and REM, guided measurement of common metrics that are key to effective community engagement as well as exploration of unanticipated outcomes.
Advanced surrogate model for electron-scale turbulence in tokamak pedestals
Farcas, Ionut-Gabriel; Merlo, Gabriele; Jenko, Frank (Cambridge University Press, 2024-10-28)
We derive an advanced surrogate model for predicting turbulent transport at the edge of tokamaks driven by electron temperature gradient (ETG) modes. Our derivation is based on a recently developed sensitivity-driven sparse grid interpolation approach for uncertainty quantification and sensitivity analysis at scale, which informs the set of parameters that define the surrogate model as a scaling law. Our model reveals that ETG-driven electron heat flux is influenced by the safety factor q, electron beta βe and normalized electron Debye length λD, in addition to well-established parameters such as the electron temperature and density gradients. To assess the trustworthiness of our model’s predictions beyond training, we compute prediction intervals using bootstrapping. The surrogate model’s predictive power is tested across a wide range of parameter values, including within-distribution testing parameters (to verify our model) as well as out-of-bounds and out-of-distribution testing (to validate the proposed model). Overall, validation efforts show that our model competes well with, or can even outperform, existing scaling laws in predicting ETG-driven transport.
Scientific machine learning based reduced-order models for plasma turbulence simulations
Gahr, Constantin; Farcas, Ionut-Gabriel; Jenko, Frank (AIP Publishing, 2024-11-18)
This paper investigates non-intrusive Scientific Machine Learning (SciML) Reduced-Order Models (ROMs) for plasma turbulence simulations. In particular, we focus on Operator Inference (OpInf) to build low-cost physics-based ROMs from data for such simulations. As a representative example, we consider the (classical) Hasegawa-Wakatani (HW) equations used for modeling two-dimensional electrostatic drift-wave turbulence. For a comprehensive perspective of the potential of OpInf to construct predictive ROMs, we consider three setups for the HW equations by varying a key parameter, namely, the adiabaticity coefficient. These setups lead to the formation of complex and nonlinear dynamics, which makes the construction of predictive ROMs of any kind challenging. We generate the training datasets by performing direct numerical simulations of the HW equations and recording the computed state data and outputs over a time horizon of 100 time units in the turbulent phase. We then use these datasets to construct OpInf ROMs for predictions over 400 additional time units, that is, 400 % more than the training horizon. Our results show that the OpInf ROMs capture important statistical features of the turbulent dynamics and generalize beyond the training time horizon while reducing the computational effort of the high-fidelity simulation by up to five orders of magnitude. In the broader context of fusion research, this shows that non-intrusive SciML ROMs have the potential to drastically accelerate numerical studies, which can ultimately enable tasks such as the design of optimized fusion devices.
Rebranding Pigmentocracy: Analyzing Marketing Strategies of Unilever’s Skin Lightening Products
Dhillon-Jamerson, Komal (Oxford University Press, 2025-04-01)
This paper examines the trajectory of Hindustan Unilever—a subsidiary of the UK-based consumer goods giant—and its video advertisements for skin lightening products over the past 15 years, critiquing the company’s rebranding of Fair & Lovely to Glow & Lovely. Prior to its rebranding in 2020, Unilever’s Fair & Lovely regularly promoted skin-bleaching products by emphasising the disadvantages associated with darker skin, including fewer marriage prospects and a lack of employment opportunities. Due to increasing public criticisms, Glow & Lovely’s rebranding attempts to convey outward racial sensitivity by moving away from highlighting the benefits of “fairness” and instead shifting focus to healthy skin that Unilever characterizes as “glowing, radiant, and even.” However, discourse analysis of commercials explores the ways in which both social disadvantages and advantages related to skin colour—such as the so-called “pretty privilege” associated with lighter skin—are still exploited through problematic narratives, meanings and representations. In short, the discourse analysis reveals that despite its rebranding, Unilever continues to rely on the logic of western-based racial and gender ideals for its marketing campaigns. In an effort to downplay the pigmentocratic implications, a spurious importance on gender equality is also utilized in the new marketing material, revealing changing meanings across the past 15-year timespan of the brand. Indeed, the intersectional analysis sheds light on how Unilever’s advertisements claim to promote gender and racial inclusivity, yet instead function to promote longstanding inequalities.
Author Meets Critic Public Talk: Gratuitous Angst in White America: A Theory of Whiteness and Crime by Deena A. Isom
Dhillon-Jamerson, Komal (2024-04-04)
Gratuitous Angst in White America provides important insight into the intersections of white fragility and male fragility as they relate to criminality. Isom’s engagement with multiple theories emphasizes the creation of normative racial categories across space and time, while filling gaps related to the role of whiteness in matters related to crime and the decreased likelihood of entanglement with the criminal legal system. In this way, Isom furthers our understanding of what constitutes as crime, who is a criminal, and who deserves to be punished by considering these questions through the lens of whiteness and white privilege.
Global well-posedness and scattering results for nonlinear waves
Camliyurt, Guher; Kenig, Carlos E. (2024-10-23)
I’m not an Indian, I am a Tarahumara: Images and Narratives by the Rarámuri in Ciudad Juárez
Diaz, Selene (2025)
Since the foundation of the Mexican nation, the government and mass media have portrayed the Rarámuri as isolated from civilization. However, for the Rarámuri in the Sierra Tarahumara, a life of isolation away from major cities is not part of their ethnic identity. Rather, it is their predilection for wandering the mountains on foot that identifies them as an ethnic group and connects them to their ancestors and worldview. Given this defining characteristic, how do the Rarámuri who tread the asphalt trails of Ciudad Juárez (re)construct their ethnic identity? I use feminist ethnography to discern interethnic relationships between Rarámuri and chabochi (a Rarámuri word meaning “sons of the devil” or simply “non-Indigenous”) in Ciudad Juarez. The use of narratives based on pictures of the city allows the Rarámuri to reflect on their life experiences in Ciudad Juárez. This study finds that experiences of discrimination increase in downtown Ciudad Juárez. However, living in Colonia Tarahumara or Kilómetro 30 and belonging to the artisan community helps them mitigate the second ethnicization and reconstruct their ethnic identity by creating strong bonds of solidarity and pride through community work.
The Culture and Politics of Populist Masculinities [Book review]
King, Neal (SAGE, 2022-01-22)
Climate Change Deniers versus Climate Change Decriers: The Pragmatics of Climate Defense in the Age of Disinformation
Luke, Timothy W. (University of Texas at Arlington Libraries, 2024-10-29)
Thirty-five years ago, Bill McKibben published his best-selling popular depiction of climate change, The End of Nature. Nearly a decade ago, Naomi Klein's global best-seller This Changes Everything: Capitalism vs. The Climate presented her detailed brief: “thought leaders” must resist and reverse the degradation of Earth's climate in the face of denials that this policy change was impossible. As popular activists, McKibben and Klein both believe “more information leads to good and great change.” This gambit presumes when presented disturbing facts on how and why rising fossil fuel use is degrading the climate, like-minded readers will wisely rise, readily organize and rationally stop such destruction. Both authors have thriving careers as “thought leaders,” but the gamble that informative writing would inspire game-changing decisive actions has backfired. In fact, the intensity of their climate decrying for millions of “action laggards” is twisted into disinformation to justify climate denying. Nature has not ended, and climate change has not changed everything. Costly climate disasters are increasing; but habits of embedded symbolic action tied to moralistic decrying suggest McKibben and Klein now play new roles as artful traders in the networks of disinformation. In today’s ESG-guided climate politics, major energy companies nod appreciatively to climate decriers, pledging future perfection at carbon reduction in contrite denialist exchange for sustaining the continued present degradation of their carbon emissions. This is a puzzle. Are answers to the puzzle to be found in Klein’s latest book, Doppelganger: A Trip into the Mirror World, which explores to what degree everyday life now is not engaged with the natural world? Instead, denial and disinformation seem to ensnare it in “trips into the Mirror World” where sustainable degradation produces “digital doubles” of fulfilled future pledges of true sustainability in the 24x7 attention economy underpinned by the falsehoods of current concentrated carbon intensity.
The Anthropocene and Freedom: Terrestrial time as political mystification
Luke, Timothy W. (2013-10)
Intolerance of uncertainty as a predictor of anxiety severity and trajectory during the COVID-19 pandemic
Breaux, Rosanna; Naragon-Gainey, Kristin; Katz, Benjamin; Starr, Lisa; Stewart, Jeremy; Teachman, Bethany; Burkhouse, Katie; Caulfield, M. Kathleen; Cha, Christine; Cooper, Samuel; Dalmaijer, Edwin; Kriegshauser, Katie; Kusmierski, Susan; Ladouceur, Cecile; Asmundson, Gordon; Davis Goodwine, Darlene; Fried, Eiko; Gratch, Ilana; Kendall, Philip; Lissek, Shmuel; Manbeck, Adrienne; McFayden, Tyler; Price, Rebecca; Roecklein, Kathryn; Wright, Aidan; Yovel, Iftah; Hallion, Lauren (Pergamon-Elsevier, 2024-08-03)
Background: Efforts to identify risk and resilience factors for anxiety severity and course during the COVID-19 pandemic have focused primarily on demographic rather than psychological variables. Intolerance of uncertainty (IU), a transdiagnostic risk factor for anxiety, may be a particularly relevant vulnerability factor. Method: N = 641 adults with pre-pandemic anxiety data reported their anxiety, IU, and other pandemic and mental health-related variables at least once and up to four times during the COVID-19 pandemic, with assessments beginning in May 2020 through March 2021. Results: In preregistered analyses using latent growth models, higher IU at the first pandemic timepoint predicted more severe anxiety, but also a sharper decline in anxiety, across timepoints. This finding was robust to the addition of pre-pandemic anxiety and demographic predictors as covariates (in the full sample) as well as pre-pandemic depression severity (in participants for whom pre-pandemic depression data were available). Younger age, lower self/parent education, and self-reported history of COVID-19 illness at the first pandemic timepoint predicted more severe anxiety across timepoints with strong model fit, but did not predict anxiety trajectory. Conclusions: IU prospectively predicted more severe anxiety but a sharper decrease in anxiety over time during the pandemic, including after adjustment for covariates. IU therefore appears to have unique and specific predictive utility with respect to anxiety in the context of the COVID-19 pandemic.
Black Representation and District Compactness in Southern Congressional Districts
Goedert, Nicholas; Hildebrand, Robert; Pierson, Matthew; Travis, Laurel; Fravel, Jamie (2024-04-01)
This paper explores the assumed trade-off between district compactness and Black representation in legislative districts in the American South. We perform analysis both on heuristically generated districts using current US demographics, and on historical congressional maps since the 1970s. Computations are performed using an iterative heuristic to find feasible solutions guided by multiple objectives. We find that while the trade-off has been strongly observed historically, it is possible to effectively address both goals simultaneously in most cases. We are able to demonstrate maps substantially superior to the present enacted maps on both dimensions in at least seven of nine states analyzed. Nevertheless, the trade-off appears more necessary in states with larger and/or more heavily rural Black populations than in more urbanized states, where the drawing of compact Blackinfluence districts is easier.
Flexible Assessment in Higher Education: A Comprehensive Review of Strategies and Implications
Barua, Lumbini; Lockee, Barbara B. (Springer, 2025-02-01)
The article highlights the growing significance of flexible assessment in higher education as institutions adapt to the increasingly diverse needs of their student populations. The demand for customizable educational experiences, heightened by the COVID-19 pandemic, has made flexibility in assessment essential for sustaining and improving student engagement, satisfaction, and outcomes. This review explores various strategies for implementing flexible assessment, including flexible tasks, formats, weighting, deadlines, feedback, and deliberate planning. It also addresses the challenges, such as choice overload and increased instructor workload, that can arise when flexibility is not carefully implemented. Through a comprehensive review of existing and recent research, the article reiterates the proven benefits of flexible assessment while offering evidence-based recommendations for effective implementation. It calls for further research to develop assessment practices that can contribute to a more adaptable and equitable assessment environment for today’s modern learners.
Embracing synthetic life? How US publics make sense of the promises and threats of new synthetic cell technologies
Halcomb, Laura; Satterfield, Terre; Kandlikar, Millind; Budge, Jason; Harthorn, Barbara (2025)
A fluid mechanical study of rotation-induced traumatic brain injury
Wang, Qifu; Zhang, Jiaqi; Bates, David; Feng, James J.; Yue, Pengtao; Wu, Qianhong (2025)
Traumatic brain injury (TBI) is a serious health issue. Studies have highlighted the severity of rotation induced TBI. However, the role of cerebrospinal fluid (CSF) in transmitting the impact from the skull to the soft brain matter remains unclear. Herein, we use experiments and computations to define and probe this role in a simplified setup. A spherical hydrogel ball, serving as a soft brain model, was subjected to controlled rotation within a water bath, emulating the CSF, filling a transparent cylinder. The cylinder and ball velocities, as well as the ball’s deformation over time, were measured. We found that the soft hydrogel ball is very sensitive to decelerating rotational impacts, experiencing significant deformation during the process. A finite-element code is written to simulate the process. The hydrogel ball is modelled as a poroelastic material infused with fluid and its coupling with the suspending fluid is handled by an arbitrary Lagrangian-Eulerian method. The results indicate that the density contrast, as well as the rotational velocity difference, between the hydrogel ball and the suspending fluid play a central role in the ball’s deformation due to centrifugal forces. This approach contributes a deeper understanding of brain injuries and may portend the development of preventive measures and improved treatment strategies.
Sustainabilization: A Critique of Green Economy(s)
Luke, Timothy W. (2016-09-22)
Postmodern Geopolitics in the 21st Century: Lessons from the 9.11.01 Terrorist Attacks
Luke, Timothy W. (2003-11-30)
Plasma SOMAmer proteomics of postoperative delirium
Leung, Jacqueline M.; Rojas, Julio C.; Sands, Laura P.; Chan, Brandon; Rajbanshi, Binita; Du, Zhiyuan; Du, Pang (Wiley, 2024-02-12)
Background: Postoperative delirium is prevalent in older adults and has been shown to increase the risk of long-term cognitive decline. Plasma biomarkers to identify the risk for postoperative delirium and the risk of Alzheimer's disease and related dementias are needed. Methods: This biomarker discovery case–control study aimed to identify plasma biomarkers associated with postoperative delirium. Patients aged ≥65 years undergoing major elective noncardiac surgery were recruited. The preoperative plasma proteome was interrogated with SOMAmer-based technology targeting 1433 biomarkers. Results: In 40 patients (20 with vs. 20 without postoperative delirium), a preoperative panel of 12 biomarkers discriminated patients with postoperative delirium with an accuracy of 97.5%. The final model of five biomarkers delivered a leave-one-out cross-validation accuracy of 80%. Represented biological pathways included lysosomal and immune response functions. Conclusion: In older patients who have undergone major surgery, plasma SOMAmer proteomics may provide a relatively non-invasive benchmark to identify biomarkers associated with postoperative delirium.
Tissue-specific responses to oxidative fuel source preference during heat stress in lactating dairy cows
Ellett, Mark D.; Daniels, Kristy M.; Hanigan, Mark D.; Corl, Benjamin A.; Perez-Hernandez, G.; Parsons, Catherine L. M.; Melvin, J. A.; Fausnacht, D. W.; McMillan, R. P.; Baumgard, L. H.; Rhoads, Robert P. (American Dairy Science Association, 2024-09-18)
Prolonged exposure to high environmental temperatures results in an accumulated heat load that induces a heat stress (HS) response in dairy cattle. Heat stress compromises dairy farm profitability by reducing milk yield, altering milk composition, and hindering reproductive performance. The ability to alternate between carbohydrate and lipid sources for energy production is termed metabolic flexibility (Met Flex). The objective of this study was to evaluate the Met Flex of mammary, muscle, and liver tissue in lactating dairy cows under HS and thermoneutral (TN) conditions. Sixteen Holstein cows were assigned to 1 of 2 treatment groups: pair-feeding in TN conditions (PFTN) or HS conditions. All cows experienced a 4-d TN period with ad libitum intake followed by a 4-d treatment period. Heat stress cows were exposed to a temperature-humidity index (THI) ranging from 76 to 80 and the PFTN cows were exposed to a THI of 64. Milk production and health data were recorded twice daily. Semitendinosus biopsies were obtained on d 4 of each period and postmortem mammary and liver samples were obtained on d 4 of period 2. All tissue samples were assayed for Met Flex. Activity of mitochondrial (Mit) enzymes were assessed in skeletal muscle only. Four days of HS decreased milk yield, altered milk composition, and increased respiration rate and rectal temperatures. No differences in Met Flex were observed in mammary or liver tissue during period 2. However, HS, but not PFTN conditions, lowered Met Flex of skeletal muscle by 18.3% when compared with TN ad libitum feed intake conditions of period 1. No treatment differences were observed in skeletal muscle Mit enzyme activity indicating the decrease in Met Flex occurred independently of changes in Mit function. The reduction in Met Flex of skeletal muscle during HS may contribute to reduced milk yield and warrants further investigation.
Cyclical heat stress during lactation influences the microstructure of the bovine mammary gland
Perez-Hernandez, G.; Ellett, Mark D.; Banda, L. J.; Dougherty, D.; Parsons, Catherine L. M.; Lengi, A. J.; Daniels, Kristy M.; Corl, Benjamin A. (Elsevier, 2024-05-31)
This study aimed to evaluate the effect of heat stress on mammary epithelial cell (MEC) losses into milk, secretory mammary tissue structure, and mammary epithelial cell activity. Sixteen multiparous Holstein cows (632 ± 12 kg BW) approximately 100 DIM housed in climate-controlled rooms were paired by BW and randomly allocated to one of 2 treatments, heat stress (HS) or pair-feeding thermoneutral (PFTN) using 2 cohorts. Each cohort was subjected to 2 periods of 4 d each. In period 1, both treatments had ad libitum access to a common TMR and were exposed to a controlled daily temperature-humidity index (THI) of 64. In period 2, HS cows were exposed to controlled cyclical heat stress (THI: 74–80), while PFTN cows remained at 64 THI and daily DMI was matched to that of the HS cows. Cows were milked twice daily, and milk yield was recorded at each milking. Individual milk samples on the last day of each period were used to quantify MEC losses by flow cytometry using butyrophilin as a cell surface marker. On the final day of period 2, individual bovine mammary tissue samples were obtained for histomorphology analysis, assessment of protein abundance, and evaluation of gene expression of targets associated with cellular capacity for milk and milk component synthesis, heat response, cellular proliferation, and autophagy. Statistical analysis was performed using the GLIMMIX procedure of SAS. Milk yield was reduced by 4.3 kg by HS (n = 7) compared with PFTN (n = 8). Independent of treatment, MEC in milk averaged 174 cells/mL (2.9% of total cells). There was no difference between HS and PFTN cows for MEC shed or concentration in milk. Alveolar area was reduced 25% by HS, and HS had 4.1 more alveoli than PFTN. The total number of nucleated MEC per area was greater in HS cows (389 ± 1.05; mean ± SE) compared with PFTN (321 ± 1.05); however, cell number per alveolus was similar between groups (25 ± 1.5 vs. 26 ± 1.4). There were no differences in relative fold expression for GLUT1, GLUT8, CSN2, CSN3, LALBA, FASN, HSPA5, and HSPA8 in HS cows compared with PFTN cows. Immunoblotting analyses showed a decrease in abundance for phosphorylated STAT5 and S6K1, and an increase in LC3 II in HS cows compared with PFTN cows. These results suggest that even if milk yield differences and histological changes occur in the bovine mammary gland after 4 d of heat exposure, MEC loss into milk, nucleated MEC number per alveolus, and gene expression of nutrient transport, milk component synthesis, and heat-stress-related targets are unaffected. In contrast, the abundance of proteins related to protein synthesis and cell survival decreased significantly, whereas proteins associated with autophagy were upregulated in HS cows compared with PFTN cows.

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