100039 research outputs found
Sort by
Groundwater-Dependent Ecosystems in Southeastern Utah: An Integrated Analysis of Hydrology, Ecology, and Landscape Change
Get PDFIn Southeastern Utah, springs play a critical role in sustaining groundwater-dependent ecosystems (GDEs) in a semi-arid environment. However, they remain understudied and face growing threats from climate change, land use modifications, and hydrologic alterations. This study addresses knowledge gaps in spring occurrence, hydrologic function, and ecological condition by integrating field surveys, remote sensing, and geospatial analysis across multiple spatial scales. It provides a comprehensive assessment of spring hydrology, water quality, and ecological conditions using field surveys, remote sensing, and GIS analysis to establish a foundational baseline of GDE resources in the region. I applied a multi-scale monitoring approach across the La Sal and Abajo Mountains, covering 59 HUC-12 subwatersheds from 2020 to 2024. During this period, inventory and measurements were taken for water quality, discharge, vegetation composition, disturbances, and developments. A total of 382 previously undocumented springs were discovered across the La Sal and Abajo Mountain ranges, which brought the total number of known springs to 597.
For discharge measurements, the results show that higher-elevation springs that emerge from unconsolidated sediments where snowpack is greatest, exhibit the highest flow rates. These springs typically emerge at the base of steep slopes where unconsolidated materials meet finer sediments with silts and clay particles. By contrast, most springs have significantly lower discharge rates and originate from precipitation that infiltrates coarse or fractured sedimentary aquifers. As the water percolates downward through these coarse sedimentary formations, it encounters lower permeable geologic formations or aquitards, which causes water to move laterally until it emerges at the surface as a spring. Using a combination of field-verified spring locations, geologic mapping, and topographic analysis, this study delineated the recharge areas and discharge zones, which helped identify the boundaries of the major aquifer systems within the La Sal and Abajo Mountains. The resulting aquifer maps will provide spatially explicit guidance for future surface management actions aimed at protecting groundwater.
Vegetation composition was surveyed across spring sites to evaluate ecological integrity and wetland condition, with particular focus on wetland indicator species as a proxy for hydrologic permanence and ecological resilience. GDEs with a greater proportion of wetland indicator species were interpreted as having a more robust wetland function and greater resistance to disturbances. In addition to dominant GDE vegetation, broader landscape-scale vegetation types surrounding each GDE were also assessed to contextualize site condition within the larger ecological setting.
As part of this study, a Water Quality Index (WQI) was developed to quantify and compare spring water quality across varying geologic and ecological settings. The WQI showed that lithology and elevation are interconnected within this region and have the largest influence on water quality. Springs at lower elevations tend to have higher salinity, conductivity, and TDS, which is attributed to longer water residence time within more soluble sediments. In contrast, there appears to be much higher quality of water within formations consistent of intrusive igneous, crystalline rocks. Other factors that play a role in water quality were shown to be livestock and ungulate use within spring sites. Sites highly affected by ungulate and livestock use had higher TDS, specific conductivity and lower dissolved oxygen (DO), but showed to be only statistically significant within the La Sal Mountains.
To complement field-based measurements and extend the spatial scope of this study, remote sensing and geospatial analysis were used to investigate broader landscape patterns. Normalized Differential Vegetation Index (NDVI) and Normalized Differential Moisture Index (NDMI) served three main purposes in this study. 1) A tool for identifying undocumented GDE’s: While the remote sensing test did identify very large GDE’s, the 30m resolution of Landsat imagery was far too coarse for accurately detecting the majority of springs. 2) To determine the landscape-scale vegetation response to precipitation variability and determine correlations: The analysis showed a very weak and insignificant correlation between same-year precipitation and vegetation production or greenness. A one-year delayed correlation slightly improved the correlation between precipitation and greenness in the Abajo Mountains. This increased delayed correlation could suggest that groundwater storage and soil moisture retention play a larger role in vegetation trends than annual precipitation alone. 3) To test and determine if grazing has a significant effect on landscape-scale NDVI values between grazed allotments and ungrazed control allotments: A statistical comparison of NDVI between the grazed and ungrazed allotment from 1999 to 2024 showed no statistically significant difference in mean NDVI values. Beyond individual spring sites, a broad livestock pressure analysis was conducted using a Livestock Impact Index (LLI), which used a combination of factors such as stocking density, days of use, precipitation-weighted average, and availability of water sources. The index incorporated data from 1999 to 2024, and the primary purpose for it was to assist land managers and range conservationists on which allotments may have the potential for most livestock impacts within GDE’s.
Lastly, this study used spatial interpolation to show long-term precipitation and temperature trends from 1999 to 2024. Data show that the La Sal Mountains receive an average of 21.4 inches of precipitation annually, while the Abajo Mountains receive 18.4 inches. The highest recorded precipitation occurred in 2015, and the lowest in 2020. A slight decrease in precipitation was observed, with reductions of 19 millimeters per decade in the La Sals and 9 millimeters per decade in the Abajos, though interannual variability remains the dominant factor. Temperature trends show a slight warming, with mean annual temperatures of 7.6°C in the La Sals and 8.3°C in the Abajos. The warmest year was 2017, while the coldest were 2011 (La Sals) and 2008 (Abajos). Temperature increases of 0.017°C per decade in the La Sals and 0.161°C per decade in the Abajos were observed
Increasing Electric Vehicle Charger Availability With a Mobile, Self-Contained Charging Station
Get PDFAs the transition to sustainable transportation has accelerated with the rise of electric vehicles (EVs), ensuring drivers have access to charging to maximize the electric miles driven is critical to lowering carbon emissions in the transportation sector. Limited charging station capacity and poor reliability, especially during peak travel times, long distance travels, holidays, and events, have hindered the adoption of EVs and threaten the progress toward reducing greenhouse gas emissions. Adaptive, flexible deployment strategies combined with innovative approaches integrating mobility and renewable energy are essential to address these systemic challenges and bridge the current infrastructure gap. To address these challenges, this study proposes a self-contained, mobile charging station (MCS). Designed for rapid deployment, the proposed MCS increases charging capacity during demand surges while minimizing reliance on fossil fuels. The feasibility of integrating a solar canopy with this MCS to further reduce carbon emissions is also studied. This study weighed the pros and cons of differing cell chemistries, sized the battery using data provided by the United States’ largest public CPO, and discussed the feasibility of a solar canopy for off-grid energy
Challenging Behavior in Inclusive Postsecondary Education Programs
Get PDFInclusive postsecondary education programs – higher education programs that are specifically designed for individuals with intellectual disabilities – have grown exponentially in the last 10 years. With this growth has come the emergence of several barriers to inclusive postsecondary education admission and completion. Given the relatively short time inclusive postsecondary education programs have existed, only a small amount of research has looked into barriers that prevent graduation from inclusive postsecondary education programs. One barrier in particular has received little to no attention from researchers – challenging behavior. Challenging behavior is a construct that includes socially inappropriate behaviors, which may harm the individual engaging in the behavior or those around them or result in exclusion from community participation. Previous research has shown that individuals with intellectual disability experience challenging behavior more frequently than the general population, with 10 – 20% of adults with intellectual disability engaging in challenging behavior. The increased susceptibility to challenging behavior compounded with the stressors of college life may result in increased rates of challenging behavior in inclusive postsecondary education settings. However, the lack of research in this area means there is no information on the type and consequence of challenging behaviors experienced by inclusive postsecondary education students. Therefore, this study sought to gather foundational information regarding challenging behavior in inclusive postsecondary education settings across the nation using a design survey distributed via the anonymous internet-based Qualtrics program
Determining the Structure and Function of Type IV-A Anti-CRISPRs
Get PDFBacteria face a constant existential threat in the form of infection by viruses along with other forms of mobile genetic elements, such as bacteriophage and transposable elements. To survive, bacteria and other prokaryotes have evolved various immune systems to evade these would-be invaders. One such immune system is the CRISPR-Cas system, an adaptive immune system able to record the genetic signature of invading viruses in order to recognize and destroy them should they be encountered again in the future. In this thesis I present data that sheds light on the mechanism of one particular subtype of CRISPR-Cas systems: the type IV-A1 system from Pseudomonas aeruginosa. I also report on some of the newly identified tools used by viruses and plasmids to evade this system, called anti-CRISPRs. The type IV-A1 system is unique in that unlike most CRISPR-Cas systems, it doesn’t appear to destroy or degrade the genome of invading viruses. Instead, it relies on an additional helicase protein called CasDinG to repress the expression of any genes near its target. I report data which explains the genetic signatures necessary to activate type IV-A CRISPR system, and I also explore the significance of a particular domain of the CasDinG helicase. This thesis also identifies the first-ever reported anti-CRISPRs against the type IV-A system, along with hypothesized mechanisms by which they repress immunity
Seasonal and Temporal Influences on Successful Crossing Rates by Ungulates of a North Utah Wildlife Overpass
Get PDFEncroachment of human infrastructure fragments wild landscapes and introduces a suite of negative impacts for humans and wildlife. In Utah, roadways threaten migratory ungulates by creating a barrier to movements and preventing access to seasonal migration routes. To mitigate these conflicts, state transportation agencies often install wildlife crossing structures to allow animals to safely cross over or under roadways. Selecting the proper crossing structure requires consideration of the species of interest, landscape, location, and structural dimensions. Often there is balance between the optimal location, the dimensions of the crossing structures, and what is feasible given the landscape. In 2018, the Utah Department of Transportation installed an overpass that was much longer than it is wide (0.13 width to length ratio, the recommended ratio is 0.8) across a major Interstate. The purpose of my study was to determine if the target species, mule deer (Odocoileus hemionus) as well as other animals such as moose (Alces alces) and elk (Cervus canadensis) would use this crossing structure. Additionally, I sought to determine if there were seasonal or temporal influences on successful crossing rates. I conducted an observational study using trail cameras installed along Parley\u27s Canyon Overpass from April 2020-July 2022, to record wildlife use of the overpass. I evaluated the proportion of crossings for mule deer, elk, and moose that occurred during different times of the day and among seasons. Mule deer and moose successfully used the overpass 97.9% (of 1,973 visits) and 100% (of 65 visits) of total visits; however, elk only made 3 successful crossings (23.08%). I determined that, due to high success rates regardless of season or time of day, mule deer feel safe enough to cross this overpass if they encounter it regardless of timing of when they encounter it. Additionally, overpasses with smaller width to length ratios like this one can be used by mule deer and moose successfully, but not elk. My research will add to the literature regarding issues in transportation, wildlife ecology, and wildlife behavior that aid in determining wildlife crossing structure design and placement preferences by ungulates in the American west
A Laboratory Study on the Hydraulics of Stepped Spillways: Effects of Step Geometry and a Labyrinth Crest
Get PDFObserved trends in extreme storms are affecting the safety of several embankment dams. Spillways are critical for safely conveying excess water in the reservoir over the dam and into the downstream river, yet many dams that were built over 40 years ago have undersized spillways to handle modern flood estimates requiring repairs and upgrades. Consequently, a unique spillway crest, the labyrinth weir, has been used as a cost-effective improvement for numerous projects to enhance discharge capacity of existing weirs. Another cost-effective option for overtopping protection due is to place a less expensive concrete, Roller-Compacted Concrete (RCC), over the dam to prevent erosion during floods. RCC is placed in layers creating flat steps that typically have a 45-degree angle instead of a vertical face down to the next step. Both the beveled step and labyrinth weir aerate the flow passing down a stepped spillway and modify the characteristics and behavior of the water including the flow depths, velocities and energy dissipation capacity, but little information is available to engineers and scientists to support the design of these stepped spillways.
Therefore, this Ph.D. study investigated how labyrinth weirs and beveled steps affect flood flows through a stepped spillway in the laboratory with a physical and modern instrumentation. Results show that beveled steps increase flow aeration, resulting in greater flow depths. They also influenced the splash and spray from the water surface, requiring higher chute walls to contain the flow. Beveled steps had slightly higher energy dissipation compared to vertical steps.
Similarly, replacing a broad-crested weir with a labyrinth weir significantly modifies flow properties at the upstream end. Enhanced aeration due to labyrinth might have further positive consequences such as greater reoxygenation of water in oxygen depleted waters. Overall, these findings demonstrate that altering step geometry or the upstream entrance conditions can substantially affect stepped spillway hydraulics, underscoring the importance of factoring such changes into stepped spillway design. Skimming flow over stepped spillway results in a highly dynamic complex multiphase structure of the air-water interface posing a challenge for precise and reliable measurements of free surface topography using conventional methods. Hence, this dissertation also investigated the feasibility of a low cost RGB-D camera technique to scan in 3D the water surface through a stepped spillway. The results confirmed its viability for studying the complicated water surface when the flow is white from entrained air
An Evaluation of Using Linked Digital Activity Schedules to Teach Sociodramatic Play
Get PDFIndividuals with ASD often have difficulties communicating with peers and navigating social interactions (APA, 2022). Building these skills may help these individuals interact with peers, siblings, and others in the community. One area where individuals with ASD may need support is engaging in play. Specifically, in engaging in sociodramatic play (i.e., pretend play that involves role-playing aspects of real life). Traditionally, applied behavior analysis (ABA) and activity schedules are evidence-based approaches that have been used to teach play behaviors to individuals with ASD. However, few researchers have evaluated how a linked digital activity schedule can increase the sociodramatic play responding of young learners with ASD. Further, the extent to which this responding transfers to untaught play scenarios has not been evaluated. Thus, the purpose of this study is to further past research using linked digital activity schedule to teach sociodramatic play to preschool-aged children diagnosed with ASD and the determine the extent to which responding transfers to untaught play scenarios. One dyad of children successfully mastered the target sociodramatic play scenario but required several changes to their procedures. This same dyad also transferred their responding to three untaught sociodramatic play scenarios. The remaining two dyads of children did not meet our mastery criteria following several changes to our procedures. We highlight the limitations of the study and directions for future research
Optimizing Nutrient Recycling to Achieve Zero–Discharge Management for Controlled Environment Agriculture
Get PDFControlled environment agriculture (CEA) allows for human control of one or more environmental factors affecting crop production. Optimizing nutrient management in such systems allows for translation and predictions of sustainable management strategies in the field. These systems will be used to supply fresh food as public and private space agencies are planning to send humans to the Moon and Mars in the near future. Food resupply becomes increasingly difficult as the distance from Earth increases. Plants can be grown off-Earth as a food source, but their growth must be carefully managed to ensure long-term sustainability. I describe a model used to determine human nitrogen needs, a validation of a part of this model using lettuce, and an expansion of this framework to additional essential elements for plant and human nutrition. Nitrogen is poorly managed in crop systems on Earth, but inefficiencies must be reduced to ensure long-term recyclability of nutrients. Following the flow of nitrogen through humans and the processes required to convert it among bioavailable forms helped determine which steps could be optimized. Lettuce was used as a model crop to determine if the efficiencies predicted in the previous model could be achieved in a real-world scenario. Plants were grown repeatedly in the same substrate to simulate replanting methods. Yield was optimized when both nitrate and ammonium nitrogen were provided to the plants. The optimal fertilizer concentrations for all nutrients were calculated from the desired amount in the plant and the efficiency by which the plants could take up the nutrients. This approach was validated using lettuce in a liquid hydroponics system. An initial trial with twenty-five repeated plantings without discarding any nutrient solution showed steady-state nutrient management was possible with a few modifications. Subsequent trials with refined recipes led to tighter nutrient management control had comparable yields to plants grown using a standard dump and refill approach
Comparative DNA Methylation Profiles of Somatic Cell Nuclear Transfer Embryos and In Vitro Fertilized Embryos
No full textIn the first days of embryo development, the paternal and maternal genomes are incorporated and reprocessed into the newly functional genome of the embryo itself. Epigenetic reprogramming of this new genome is integral to the proper development of the embryo. One epigenetic mechanism involved in reprogramming is DNA methylation in which a methyl group is added or removed from the DNA base cytosine. The functional form of DNA methylation occurs on a cytosine base when followed by a guanine base held together with a phosphate linkage (CpG). A high cluster of CpG sites is galled a CpG island and are found near the transcription start sites of genes. The presence of CpG methylation can inhibit gene transcription by adding to a crowded repressive chromatin state.
The importance of classifying DNA methylation patterns in somatic cell nuclear transfer (SCNT) embryos can provide insight into the mechanisms in which a donor fibroblast is reconstructed and the ability to differentiate leading to further embryo development. Largely, SCNT embryos have poor success rates of live offspring compared to in vitro fertilization (IVF) embryos. Our data show differential success of pregnancies between SCNT embryos generated from different donor fibroblast lines. Our major goal of this study is to determine potential epigenetic memory or retained DNA methylation of donor fibroblasts in their respective SCNT embryos.
We compared the DNA methylation profiles of developmentally important genes: NANOG, SOX2, LIN28, cMYC, KLF4, and OCT4 (POU5F1) in bovine SCNT and in vitro fertilized (IVF) embryos as well as 3 fibroblast cell lines used for SCNT. Fibroblast cell lines were selected based on pregnancy success with 2 lines showing high potential (WG and CT) and 1 showing low potential (KF). We used a high throughput bisulfate sequencing workflow to classify DNA methylation profiles of each gene region in 2-cell, 8-cell, morulae and blastocyst stage embryos as well as fibroblasts and oocyte samples.
Our results showed differences in DNA methylation patterns on a per base resolution between SCNT embryos and IVF embryos across the 6 genes of interest. We also found differences between the 3 fibroblast cell lines in the NANOG and SOX2 gene regions. Specifically, our research showed 1) aberrant SOX2 promoter hypomethylation in KF SCNT embryos from the 2-cell stage up to blastocysts generated from low potential KF fibroblasts suggesting retained epigenetic memory or failure of de novo methylation and 2) Hypermethylation in 2-cell CT SCNT and significant hypomethylation in KF SCNT morulae in the NANOG gene region. Our data suggest potentially faulty DNA methylation of genes crucial to the development in pre-implantation embryos that could contribute to the poor success seen in select donor fibroblast cell lines used in SCNT
Increasing the Spatial Resolution of Snow Hydrology Data and Augmenting Existing Hydrology Monitoring Networks Using Low-Cost Snow Sensing Stations
Get PDFSnow is a crucial part of the water cycle, especially in mountainous regions where melting snow provides water for millions of people. However, accurately measuring how much water is stored in snow is challenging. Current monitoring networks, such as the snowpack telemetry (SNOTEL) network in the western United States, provide valuable data, but have gaps in coverage and are expensive to operate and expand. This research explores a more affordable way to improve snow measurements by designing and testing low-cost snow sensing stations. These stations use open-source datalogger and software technology along with research-grade sensors to measure important snow variables. They are designed to operate in a variety of landscapes where traditional snow monitoring stations cannot be placed. To ensure the collected data is accessible, the stations use wireless networks to transmit data in real-time. A case study in Utah\u27s Logan River watershed tested these stations and found that they provided reliable data while revealing differences in snow patterns over short distances. By making snow monitoring more affordable and widely available, this research helps improve water management and forecasting. The study also provides a guide for others to build similar stations, supporting future research and better understanding of snow-dependent water systems