8413 research outputs found
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Remote-sensing and statistical approaches to evaluating landscape changes associated with targeted livestock grazing
No full textIt is estimated that more than 20% of the Great Basin sagebrush rangelands are invaded by cheatgrass (Bromus tectorum L.). Land managers have been exploring the use of targeted livestock grazing to mitigate wildfires in cheatgrass-invaded sagebrush rangelands but the results of these trials have demonstrated variable levels of success. Uncrewed aerial vehicles (UAVs) mounted with active (e.g. LiDAR) or passive sensors (e.g. optical multispectral camera) have been used as a possible tool for detecting changes associated at the landscape spatial scale that are associated with targeted grazing treatments. In this dissertation I evaluate the effectiveness of autumn or fall-season targeted grazing in reducing cheatgrass-dominated fine fuel cover, structure, and connectivity by using field and UAV-derived measures of vegetation canopy cover and structure. Vegetation composition, canopy cover, and structural metrics acquired by these technologies are ultimately used to estimated aboveground biomass in drylands, or more specifically, the amount and connectivity of fine fuel. However, I first conducted a systematic literature review of how aboveground biomass is indirectly estimated in shrubland and savanna ecosystems worldwide using UAV-mounted technologies. I found this to be a knowledge gap. Secondly, at the field-plot scale, I used a non-parametric zero-inflated beta distribution in a Bayesian hierarchical framework to detect short-term changes in the occurrence, and percent conditional cover and mean cover of cheatgrass to fall-season targeted grazing. I compared the impacts of targeted grazing on plant and ground cover, structural and pattern metrics including plant height and patch dynamics using UAV-acquired time series. Finally, I share lessons learned during collaborative implementation of targeted fall-season grazing treatments across different sites and ranger districts in Nevada. The results of my dissertation show that in the short-term (1-4 years), targeted grazing treatments increased cheatgrass occurrence compared to grazing exclusion in the field cover dataset, however, targeted grazing did not increase either conditional cover or mean foliar cover of cheatgrass when compared to grazing exclusion. The UAV dataset corroborated this finding, as mean cover of a combined cheatgrass/litter fuels class did not change between summer pre-treatment and summer post-treatment years when a single application of targeted grazing treatment was applied in the autumn of 2023 at two sites. Targeted grazing treatments did increase the number of cover class patches and richness of cover class patches depending upon the study site, indicating that targeted grazing may be altering the continuity of the patches. The addition of consecutive years of targeted grazing treatment across study sites is warranted to understand longer-term effects. The results of this dissertation demonstrate that UAV monitoring of vegetation can provide insights on changes to spatial heterogeneity due to targeted livestock grazing or grazing exclusion that researchers would otherwise have difficulty detecting
Lead States Balanced Mix Design (BMD) Peer Exchange: Outcomes Summary
No full textOn September 24, 2024, seven lead States gathered for a peer exchange in Chesterfield, Missouri, and discussed their activities in advancing Balanced Mix Design (BMD) implementation. The peer exchange was sponsored by the Federal Highway Administration (FHWA). The peer exchange provided an opportunity for lead States to share their implementation status, lessons learned, and challenges encountered. The State participants also explored strategies to further enhance BMD adoption. This report summarizes key discussions of selected topics and highlights major outcomes of the peer exchange, including main takeaways, effective practices, and critical challenges identified by the lead States for implementing BMD.United States Department of TransportationFederal Highway Administratio
Development of Molecular Tools and Elucidation of Antiviral Pathways in Culex Mosquitoes
No full textMosquitoes are major vectors of disease-causing pathogens that threaten human and animal health worldwide. Culex quinquefasciatus, in particular, transmits
a variety of arboviruses, yet the molecular mechanisms underlying its antiviral
immunity remain poorly understood. This dissertation investigates key antiviral
pathways in Culex species mosquitoes, focusing on RNA interference (RNAi) and
novel immune factors that influence virus replication. In Chapter 2, we examined the role of PIWI proteins in antiviral defense. We identified Piwi4 as an antiviral factor against negative-sense RNA viruses in Culex
derived cells. Additionally, we found that all PIWI proteins have a modest impact on
virus-derived piRNA generation. In Chapter 3, to develop genetic tools for studying antiviral responses, we
generated Cx. quinquefasciatus-derived Hsu Cas9 knock-in cells. This system enables
targeted gene editing and serves as a platform for functional studies of immune
pathways. In Chapter 4, we studied Bravo, a novel antiviral protein with broad activity
against multiple arboviruses. Based on its conserved domains, we hypothesized that
Bravo is an RNA-binding protein important to the antiviral immune response in Cx.
quinquefasciatus mosquitoes. We confirmed its antiviral activity against three
different arboviruses and used truncation mutations to narrow down the antiviral
protein domains.Together, this work advances our understanding of Culex mosquito immune
responses and establishes new molecular tools for studying mosquito antiviral
defenses. By identifying key antiviral factors and improving functional genetic
approaches in Culex mosquitoes, this research contributes to broader efforts to
understand vector-virus interactions and inform strategies for mosquito-borne disease
control
Foundations for a Data Oriented Compiler Infrastructure
No full textDespite the fact that most college graduates possess the necessary skills to assemble a compiler, few actually take on the task. One major barrier is the lack of an accessible and well-designed Intermediate Representation (IR) that can support and guide new compiler authors. A thoughtfully constructed IR could significantly reduce the difficulty of compiler development and encourage more individuals to engage with this domain. To address this issue, we conduct a survey of existing compiler IR, paying particular attention to lesser-known or obscure designs that may offer untapped potential. In addition, we explore the feasibility of employing Entity Component Systems (ECS) to improve both performance and usability within compiler architecture. By combining insights from these analyses with a system capable of running code across a wide range of platforms, we lay the groundwork for a new IR; specifically aimed at lowering the barrier to entry into compiler design and empowering more developers to participate in this domain
From Classrooms to Courtrooms: The Role of Neighborhood, School, and Family in Shaping Youth Futures
No full textThis study examines how both real and perceived disparities in school quality and educational opportunities relate to incarceration. Such educational disadvantages are linked to increased risks of criminal involvement and incarceration, a dynamic referred to as the school-to-prison pipeline. While adult incarceration is known to be associated with various risk factors, limited research has explored the specific roles of neighborhood context, academic support, and school-based risks, especially in relation to both real and perceived disadvantages. This project seeks to investigate these dimensions by comparing the perceptions and experiences of non-incarcerated residents in the Reno/Sparks area with those of individuals incarcerated at the Washoe County Regional Detention Facility (WCRDF). This research will employ two different data collection strategies. The sample (n=380) consisted of two groups: residents of the Reno/Sparks area (n=191) and inmates within the WCRDF (n=189). For the Reno/Sparks public, data was collected via snowball sampling wherein respondents were provided with a QR code or link which led to the Qualtrics survey. The inmates from the WCRDF were provided with paper copies of the survey from correctional officers within the jail. Results suggest that incarcerated respondents had different perceptions of neighborhood, academic support, and school risks compared to the non-incarcerated respondents. Policy implications and changes will be further discussed. Keywords: school-to-prison pipeline, disparities in education, school quality, neighborhood risks, perceived disadvantagement, racial inequality, policy reform, restorative justice
Feminist Aesthetics: Interventions in Western Aesthetics and Art
No full textThis paper provides a critical overview of the interdisciplinary research and genealogical development of the field of Feminist Aesthetics beginning in the 1970's. I explore three major topics present in the field. Firstly feminist interventions in traditional western aesthetics. Specifically, revisionary criticisms of Immanuel Kant and Edmund Burkes aesthetic theories. Secondly, I discuss the craft/art dichotomy and the gendered dimensions of formalism. Thirdly, I discuss feminist art and the feminist critique of the nude female subject in art and the role of the body as a creative vehicle
The Effects of Analytical Thinking and Partisanship in College Students’ Detection of Political False Content on Social Media Platforms
No full textABSTRACT What factors make college students vulnerable to false content on social media? Is it a lack of analytical thinking, or does partisanship play a more decisive role in shaping susceptibility? Drawing on dual process theory, the research investigates whether individuals with higher analytical reasoning are better at detecting political false content or whether partisan alignment influences their beliefs regardless of cognitive ability. Using a within-subjects online survey experiment (N = 100), participants evaluated the accuracy, favorability, and credibility of two false political news stories: one targeting Donald Trump and the other Joe Biden.The study finds that analytical thinking, measured via the Cognitive Reflection Test (CRT), did not significantly predict participants’ belief, attitude, or cognitive assessment of false content for either stimulus. In contrast, partisanship was a consistent predictor: participants were more likely to believe, favor, and evaluate as credible the false content that aligned with their political affiliation. The study findings suggest that partisanship rather than analytical thinking drives responses to political false information on social media. By extending measurement beyond belief to include attitudinal and cognitive reactions, this study contributes to a more nuanced understanding of how false content is processed. It also challenges the assumptions that analytical thinking alone can safeguard against politically false content
X-Ray Tomography of Heap Leach Columns to Evaluate Pore Network Properties
No full textThis paper was presented at the Heap Leach Solutions Conference, October 19-21, 2025, Sparks, Nevada.Modeling run-of-mine (ROM) pore network properties within heap leach material is particularly difficult because of the challenge of validating and calibrating porosity models. This paper investigates a novel method for evaluating pore network properties from within a ROM heap leach pile. This method involves drilling and sampling composites from drill cuttings of a ROM leach pad, packing representative leach columns from the samples, compressing the samples using proprietary techniques to their corresponding interval pressures and performing numerous analyses along each step of the process. In addition to sample characterization tests, particle size distribution (PSD) analysis and compression data, High-resolution X-ray Computed Tomography, image processing and analysis, and flow simulation using Lattice Boltzmann Method (LBM) was performed on the samples both before and after compressions. Decreases in void space and porosity are observed to increase at depth. Surprisingly, total compressive displacement of the samples was primarily dependent on the concentration of fines in the interval particle size distribution (PSD) instead of on the total force applied to the sample to simulate the interval depth. Future work will involve developing a diffusion model that matches the data observed
Development of Terrain-use, Behavioral & Thermal Traits in Rangeland Sheep Using Precision Livestock Farming Tools
No full textExtensive sheep production faces imminent challenges brought about by climate change and increased agricultural product demand. Without intervention, productivity and welfare losses are expected. In response to this, an emerging suite of technologies are being developed and deployed across the globe to describe animal performance using automated and autonomous systems to drive digital phenotyping of hard to measure traits pertaining to climatic resilience. However, genetic parameter estimation for traits derived from these tools are minimally reported for small ruminants. We estimate the repeatability of GPS collar and vaginal temperature sensor derived traits in sheep in an extensive rangeland setting. We then used multiple imputation to simulate travel paths using a Hidden Markov Model to identify hidden activity states. Differences in land use and vaginal temperature traits are significant across activity states, as are their repeatability estimates. Shade usage is linked to a resilience indicator, change in live body weight
Three Essays on Corporate Finance and Bond Markets
No full textThe first chapter investigates the impact of a firm’s market value of real estate on theirunsecured bond yield spreads. As the market value of a firm’s real estate increases so too
does the firm’s collateral value. A higher collateral value can enhance recovery rates and
reduce expected default losses, particularly in the case of real estate assets that are more
easily redeployed in the secondary market, thereby lowering yield spreads. Conversely,
the costly reversibility of real estate assets can increase a firm’s risk premium, potentially
leading to higher yield spreads. In this paper we find a negative relationship between real
estate values and corporate yield spreads, supporting the collateral value channel. The
findings remain significant after controlling for standard determinants of yield spreads and
employing various robustness tests. Moreover, the collateral effect is more pronounced for
bonds with higher default and liquidity risk. Our research highlights that the collateral
value of corporate real estate, not explicitly pledged, is priced in the unsecured corporate
debt. The second chapter examines the impact of debt refinancing risk on expected corporatebond returns. The immediacy of refinancing maturing debt can elevate rollover risk premia,
resulting in higher future bond returns, while a firm’s short-term debt can serve as a
discipline device to alleviate agency costs of debt, reducing potential risk for bondholders.
We identify a strong positive effect of debt refinancing risk, as measured by refinancing intensity,
on excess bond returns in the subsequent year, supporting the rollover risk channel.
Such an effect intensifies with heightened default and liquidity risk, and in the presence
of credit market freezes and elevated interest rates. Furthermore, the premium associated
with refinancing risk reflects a higher exposure to credit and liquidity risk. Our study
provides new empirical evidence that the rollover risk of short-term debt is priced in the
corporate bond market. In the third chapter, we study the effect of firm-level vertical integration on corporateyield spreads. Vertical integration can lower transaction costs and enhance a firm’s control
over its supply chain, thereby mitigating supply chain risk and leading to lower yield
spreads. However, it may also lead to asset specificity, which can reduce the liquidation
value of assets and increase investment uncertainty, potentially resulting in higher yield
spreads. We find that firms with greater vertical integration exhibit lower bond yield
spreads. This effect is more pronounced for companies facing elevated supply chain risk,
supporting the supply chain risk channel. Amid global supply chain disruptions such as
the Covid-19 pandemic and the U.S.-China trade war, vertical integration takes on an even
more important role in reducing credit spreads