UARK (University of Arkansas )
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Big Blue
Get PDFBig Blue is a record keeping system of sorts- to show the story of my relationship with the tallgrass Big Bluestem as an Oglala Lakota tribal citizen of The Sioux Nation. It’s meant to question the idea of binaries, what is valued, how verticality is only powerful if supported horizontally, and the legacy of the remnants that remain. Big Bluestem is a reminder of our linked survival as humans with the land and the importance of knowing the individual names of the leafy and legged beings who exist equally on it
Fish Cultivation in Fallow Season Rice Fields: Effects on Landscape Methane Emissions
Get PDFCo-cultivation of aquatic animals and rice in the same field is a fairly common practice in various parts of the world, with a number of well-established agro-ecological benefits, such as decreasing the need for chemical pesticides and fertilizers, increasing soil organic matter, and reducing the land area needed for agricultural production. One area of environmental concern in rice production is greenhouse gas emissions. Rice production contributes about 10% of global anthropogenic methane (CH4) emissions. Currently around 27.5% of Arkansas rice fields are flooded in the winter, which can increase CH4 emissions in the fallow season by 45% compared to non-flooded fields. Evidence from other systems suggests that co-cultivation techniques may reduce CH4 emissions through trophic cascading and provide a second revenue stream to farmers along with the rice crop. The objective of this research was to analyze the effects of cultivating golden shiners, a native fish species, on fallow season CH4 emissions in an Arkansas rice field using the eddy covariance (EC) method. This study uses a pair of long-term continuous rice rotation fields in Lonoke County, Arkansas to quantify the effects of golden shiners on fallow season CH4 emissions with fish added to one field and the other field left flooded without fish. Fluxes in both fields were found to be very low when compared to growing season emissions. Initial results on CH4 emissions reductions are mixed, and certain difficulties such as gaps in the data, lack of field replicates, and variability in soil properties and management practices between the fields make it challenging to derive robust conclusions about the impacts of fish presence on CH4 emissions. Incorporating water sample results, collecting more years of data, increasing the number of field replicates, and trying more alternative approaches like chamber measurements of CH4 flux could provide more insight into the ecological mechanisms at work in this system
Overlook
No full textThe project consists of an introductory essay, three main short story sections, and finally the titular novella as the anchor. I found inspiration in Tommy Orange’s There There to open with a nonfiction prologue that contextualizes the fiction. The essay encapsulates my reckoning with place and the realization that I belong in a rich lineage of Southern literature in more ways than one. The essay, like the thesis as a whole, is a meditation on my inheritance of storytelling—the complex relationship between life and fiction, what we remember, who remembers what, and how we remember it.
My work reflects my journey in the program: At first feeling apart from or ashamed of the place I’m from, to reflecting on my origins, and ending with a symbolic embracing of my identity as an Arkansan writer. Foregrounded by each of the “Arkansas Traveler” sections, the short stories follow that thematic arc while interrogating a blend of mythologies. The final section, “Overlook,” is the natural progression from acceptance to celebration where I set out to create an original Southern mythos of my own
Investigation and Characterization of Silicon Carbide Power MOSFETs
Get PDFAs engineers constantly seek to make solar power systems smaller, cheaper, and more efficient, technological enhancements in the electronics that run them are required. One of the most fundamental electronic components of any solar system is the inverter, which takes DC current from the solar cell and turns it into AC current that is supported by the grid. This is done with metal oxide semiconductor field effect transistors (MOSFETs). Through more advanced MOSFET technology, inverters can switch at a higher frequency, increasing efficiency and reducing size and cost.
MOSFET performance can be enhanced by swapping the traditional silicon substrate with silicon carbide. Silicon carbide MOSFETs pose a variety of advantages over traditional silicon MOSFETs, including better temperature stability and higher voltage and current tolerance. A higher inverter frequency is key to increased efficiency, but this increases operating temperature. Thus, silicon carbide is desirable for use in inverters. However, improvements are still needed to fully realize a fully silicon carbide solar system future.
This paper explores the basics of solar inverters and power MOSFETs. We explore the physics behind why silicon carbide is superior to silicon in power applications and discuss various test parameters used to characterize MOSFETs. We obtain laboratory data to test various characteristics of silicon carbide MOSFETs and compare this to data of silicon MOSFETs to compare advantages and disadvantages. This paper’s results show that silicon carbide-based MOSFETs are more stable at high temperatures compared to silicon-based MOSFETs, but they exhibit higher gate leakage current compared to their silicon counterparts, indicating that there is still room to improve silicon carbide technology in the future
Board-Head Relationships: The Role of Relational Trust and Intentional Care in Fostering Head of School Well-Being
Get PDFGiven the challenges of school leadership and high rates of school leader attrition, scholars have increasingly given attention to the wellbeing of heads of schools. However, that research has not considered the way governing boards potentially influence head of school wellbeing. We fill this gap by examining how relational dynamics between heads of school and governing boards are associated with head of school wellbeing. Using data from about 140 heads of schools who participated in the Society for Classical Learning’s 2023 Thriving Schools Survey, we find that (a) relational trust between heads and boards and (b) care of the head by the board are associated with multiple indicators of head of school wellbeing
Justification for the Biological Foundation of Methane on Mars: Methanogens’ Capacity to Metabolize on Montmorillonite Clay and Basalt
Get PDFThe possibility of extraterrestrial life, particularly on Mars, remains a compelling question in astrobiology. Mars\u27 harsh atmospheric conditions, dominated by carbon dioxide and extreme cold, prevent the survival of aerobic species. However, it still leaves the possibility of methanogens, an anaerobic species that can survive in extreme conditions, to inhabit this planet. Due to the discovery of methane on Mars, it is possible that methanogens may live and grow in the subsurface of this planet.
For this experiment, basalt and montmorillonite clay were chosen as substrates because they are believed to be found in the composition of Mars\u27s subsurface. Methane, a product of methanogen metabolism, was measured to indicate if Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum, or Methanococcus maripaludis, could live on the nutrients the substrates provided. This would help decipher if different strains of methanogens could possibly survive on Mars.
Results from initial experiments revealed that M. wolfeii, M. barkeri, and M. formicicum efficiently utilized nutrients from the basalt in a bicarbonate buffer. Subsequent transfer experiments showed sustained growth for M. wolfeii and M. barkeri, with final transfers indicating that basalt might supply sufficient nutrients to support M. barkeri alone. Additional experiments with montmorillonite clay demonstrated higher methane production with 0.5 grams of montmorillonite clay compared to 0.05 grams, suggesting that nutrient availability in clay-rich media could mimic Mars\u27 subsurface conditions with limited liquid water.
The data from both experiments further suggest that life may be possible on Mars. It also suggests that the subsurface components of this planet can provide enough nutrients for certain methanogen strains to survive
Assessing the prevalence of Ehrlichia spp. in ticks associated with canids in Arkansas
Get PDFCanine ehrlichiosis is a disease that is commonly seen in dogs. In previous studies, the southeastern part of the United States has been identified as an area of high prevalence. Arkansas was included in the region where the prevalence is high. Changes in climate, household income, and tick population were identified as factors contributing to this high prevalence. Canine ehrlichiosis is caused by three Ehrlichia spp., which are E. canis, E. ewingii, and E. chaffeensis. Ticks are responsible for transmitting the disease, specifically R. sanguineus, D. variabilis, and A. americanum. For this study, the goal was to determine the prevalence of Ehrlichia spp. in Arkansas known to cause canine ehrlichiosis. Ticks were collected off host canines and from environmental locations frequented by dogs during the summer months. These ticks were identified by sex, species, and stage, and then they were pooled by location date and tested using quantitative polymerase chain reaction (qPCR). Individuals from positive pools were tested again using qPCR, and then, if positive, Sanger sequencing was used to identify what Ehrlichia spp. the tick was carrying. SNAP 4DX ehrlichiosis data was recorded at two veterinary clinics in Arkansas in order to determine prevalence in dogs. Amongst collected ticks, 88.4% were A. americanum, 7.5% were D. variabilis, 3.1% were A. maculatum, 0.8% were I. scapularis, and 0.2% were I. cookei. Only D. variabilis and A. americanum were included in testing, as they were tick species known to carry the three Ehrlichia spp. Only A. americanum ticks were identified as carriers through Sanger sequencing, and, out of the A. americanum population, 1.8% carried E. ewingii, 0.92% carried E. chaffeensis, and 0.92% carried Panola Mountain Ehrlichia. No co-infection or E. canis was found. In the SNAP 4DX testing, the first clinic showed 23.24% of tests were positive in 2023 and 22.12% in 2024. The data collected from the second clinic showed that the percentage of positive tests was 22.41% in 2024
Comparative Trends in Campaign Fundraising for United States Democratic Senatorial Candidates After Citizens United
Get PDFPolitical polarization has grown more prevalent in the United States political atmosphere in recent years (Pew Research Center 2017). While political polarization is a prevalent topic of discussion, there is a limited understanding of exactly how polarization affects various aspects of political elections, such as the financing of campaigns. This research aims to explore the relationships between the ideological scores of U.S. Senate candidates and the varying types of campaign funding that they received, such as individual contributions, independent expenditures, PAC contributions, and party contributions. A data analysis was conducted utilizing Stanford University’s Database on Ideology, Money in Politics, and Elections to analyze the fundraising data of candidates and the recipient\u27s composite ideological score to determine the level of extremism of candidates. This analysis investigated the Democratic senatorial candidates in the election cycles from 2012 to 2020 to determine whether there is a relationship between campaign finance and candidate extremism. Based on the current literature on the topic establishing relationships between these variables, I hypothesized that the more ideologically extreme Democrat candidates would receive a more significant amount of funding from individual donors and independent expenditures from ideological groups. Meanwhile, the moderate candidates would rely more on contributions from their political party and PACs
Dental Microwear of Miocene Primates from the Carpathian Basin, Rudabánya, Hungary
Get PDFThis study reconstructs and compares the dietary habits of the late Miocene primates Anapithecus hernyaki and Rudapithecus hungaricus by analyzing dental microwear patterns on fossilized teeth recovered from Rudabánya, Hungary. Previous research suggested that these sympatric species were both primarily frugivores but were unable to separate them by diet. However, earlier studies were limited by smaller sample sizes and less advanced methodologies. This study used an expanded sample and modern microwear texture analysis techniques to compare molar and incisor microwear patterns between the two species. Results revealed that Rudapithecus molars exhibited higher complexity compared to Anapithecus molar complexity, suggesting a diet that included harder foods compared to Anapithecus. Despite this difference, both species maintained relatively low complexity values, reinforcing that their diet was primarily frugivory. These findings provide new insights into niche partitioning, suggesting that subtle differences in fallback food consumption may have contributed to the ecological coexistence of these Miocene primates