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Penny For Your Thoughts: Exploring Mechanisms Linking Socioeconomic Status and Cognition
Get PDFSocioeconomic status is a complex psychological construct linked to a number of professional and personal barriers, including cognitive deficits. Throughout this dissertation, I seek to examine the mechanisms that link socioeconomic status and cognition. First, I explore potential mediators in the link between adolescent family income and cognition in adulthood, identifying education, stressful life events, inflammation, and family education expectations as significant mediators. Next, I examine the effects of writing-based stress manipulations on long-term memory and working memory, as these effects may mimic stress from financial worry. In doing so, I identify potential effects on working memory parameters. Finally, in a thorough literature review, I propose The Bucket Model of Socioeconomic Working Memory Disparities, which attributes socioeconomic deficits in working memory to increased worry, rumination, and social comparison. In doing so, I review socioeconomic barriers to success, summarize links between socioeconomic status and cognitive, and explore the role of working memory in these processes, along with potential influences of worry and rumination
Constraining Neutron Star Kicks through Gravitational Wave Detection
Get PDFNeutron stars have, on average, much higher proper motions than those of hot and bright O and B type main sequence stars. Thus, it is widely suspected that asymmetries in core-collapse supernovae provide a substantial kick to these compact objects at birth. Gen- eral Relativity predicts that such supernova asymmetries will generate bursts of gravitational radiation, though no such burst has been yet detected. Here we argue that the polarization amplitudes of those gravitational waves can be used to calculate the kicks imparted on that nascent neutron star. We begin by reviewing the evidence for natal kicks, then we describe the mechanisms for these kicks, then we connect the kicks with their gravitational wave emis- sions. We conclude with a sample calculation, demonstrating the amplitude of gravitational waves we should expect to see given the evidence in favor of the existence of natal kicks
Regulatory Compliance Standards and Power System Reliability: A Study on Inverter-Based Resources
Get PDFThe increasing penetration of renewable energy, particularly inverter-based resources (IBRs), has reshaped the dynamics of modern power systems. This thesis investigates the impact of regulatory compliance, especially frequency ride-through requirements under NERC PRC-029-1, on the performance and reliability of interconnected multi-area systems. Using a MATLAB/Simulink-based state-space model built on the foundational structure proposed by Murty [31] and augmented with advanced control methods such as Linear Quadratic Regulator (LQR) control from Mackey and McCann [32] and further refined in the context of IBR damping by Alsarray and McCann [33], we explore three configurations of a three-area load frequency control (LFC) system. These include a baseline scenario with conventional synchronous generators, an IBR scenario without ride-through compliance, and a compliant IBR scenario implementing PRC-029-1 thresholds. Each configuration is tested using a step disturbance in Area 2 to evaluate frequency deviation, power exchange, mechanical output, and control inputs.
Simulation results highlight the adverse effects of non-compliant IBRs, including increased frequency instability and the shifting of dynamic burden to remaining synchronous areas. In contrast, compliant IBRs that remain connected during transients significantly improve system damping and maintain inter-area balance. The findings underscore the importance of Reliability Standards in ensuring grid stability amid rising renewable penetration. The study concludes that thoughtful integration of control strategies and compliance logic is instrumental in enabling the reliable operation of future low-inertia power systems
Examining Stable Isotope Variation of Herbivores in South Luangwa Valley in the Context of Anthropogenic Influences
No full textStable isotopes are an effective tool for inferring mammalian behavior. Though there are multiple factors that can influence mammalian diets, anthropogenic influence is one that is often overlooked. For example, it is important to consider how wildlife living in areas where there are frequent, documented human-wildlife interactions will modify behavior. National Parks (NPs) are a great example of this because of the common misconception that since there are protections in place, that means it is devoid of anthropogenic influence. South Luangwa National Park contradicts this misconception. Though there are protections for wildlife in place within the park, it is unfenced and allows for the movement of animals from within to outside of the park. On the border of the national park is a village, Mfuwe, which is located near the entrance of the park. There are known human-wildlife conflicts (HWCs) in the area, which define any negative interaction between humans and wildlife. Notably, one of the frequent interactions is crop raiding. Since stable isotopes of carbon (δ13C) and nitrogen (δ15N) inform us broadly about the diet of the individual, then behaviors like crop raiding would result in values that differ from individuals who did not engage in that behavior. The general and spatial variation in isotopic niche space at the species level were analyzed from seven large mammal groups in order to test this hypothesis. From these large mammal groups, the majority of individuals fell within the mixed feeder category, and there was a noted shift towards a higher integration of C4 resources as you move away from Mfuwe and the park entrance
Utility of John Deere\u27s See & Spray Ultimate in Southern U.S. Row Crops
Get PDFRow crop producers across the southern United States are observing a boom in technological advancement to improve operational efficiency. Additionally, environmental concerns and reduced profit margins drive the adoption of targeted pesticide application technologies like the John Deere See & Spray. This technology is relatively new, introduced in 2022, and producers need more insight into the shortcomings, potential herbicide savings, and the economic benefits of adoption. Since 2021, research has been conducted in Keiser, AR, with additional collaborative projects in Mississippi, North Carolina, Indiana, and Illinois. Five different objectives were addressed in this research: 1) to determine the impact of residual herbicide application methods in soybean [Glycine max (L.) Merr.]; 2) to evaluate targeted application (TA) performance in cotton (Gossypium hirsutum L.) grown with and without cover crops; 3) to quantify the likelihood of treating weeds with TA while considering the dynamics between weeds, crops, and detection settings; 4) to assess the ecological risk of adopting TA at two extreme detection settings in a three-year soybean system; 5) to quantify the opportunity cost between traditional broadcast applications and targeted sprayer systems. The first objective evaluated either TA of all herbicides (single-tank), TA of postemergence (POST)-active herbicides and broadcasting residual herbicides (dual-tank), and different residual application timings in four site years. Targeted applications provided comparable control to traditional broadcast applications across all weeds, resulting in a 28.4% to 62.4% POST herbicide savings. The second objective evaluated single-tank TA, dual-tank TA, and broadcast applications in fallow, cereal rye (Secale cereale L.), or hairy vetch (Vicia villosa Roth] cover crop systems. Overall, TA with See & Spray could detect weeds in cover crop biomass. By the end of the season, weed control for all species, including Palmer amaranth (Amaranthus palmeri S. Watson), was ≥ 92%. For Objectives 3 and 4, the lowest sensitivity settings reduced the likelihood of treating weeds, with Palmer amaranth \u3c 5cm in height being missed 39% of the time with the lowest setting, which ultimately caused an increase in weed density in subsequent years. For areas treated using the lowest sensitivity each year, the weed density increased from 867 weeds ha-1 in 2022 to 11,300 weeds ha-1 in 2024, while plots containing the high sensitivity and broadcast treatments had 2,336 weeds ha-1 at termination in 2024. For the opportunity cost, nozzles with narrower spray plume angles sprayed less, and average break-even points were determined for a John Deere 412R (Deere & Company, Moline, IL) when purchasing a new or upgrading an existing sprayer. Adopting See & Spray appears to be a viable tool to reduce the environmental loading of herbicides and enhance producer profitability if appropriately utilized. Within a program approach, targeted applications can provide comparable weed control to broadcast applications with a medium or higher sensitivity setting. Reduced weed areas improve targeted herbicide savings and emphasize the importance of highly effective residual herbicide programs and integrated weed management strategies. Lower sensitivity settings increased Palmer amaranth density in subsequent years and should not be utilized for typical herbicide applications. Return on investment will depend heavily on the investment cost, intended herbicide program cost, and weed densities at the time of application
Crispy not Risky: Effects of Environmental Conditions on Low-Moisture Food Persistent Bacterial Pathogens
Get PDFLow-moisture foods (LMFs) were not historically seen as safety risks due to their ability to inhibit pathogen growth, but evidence shows pathogens can survive in LMFs long-term, causing outbreaks and recalls. Previous studies have lacked the ability to replicate real-world contamination scenarios in LMF processing environments. This research aimed to develop inoculation methods to form LMF persistent bacterial populations (LMF PBPs) and assess pathogen responses to environmental factors, culturing methods (broth vs. lawn), and matrix type and ratio. Inoculation methods tested were “direct” (combining bacterial culture and powder on a stainless-steel coupon) and “slurry” (premixing culture and powder). Matrices included three food types (nonfat dry milk powder [NFDM], peanut butter powder [PB], and chicken powder [CP]), a nonfood matrix (silicon dioxide [SiO2]), a nonfood matrix (silicon dioxide [SiO2]), and desiccated Salmonella without a matrix (Sal). Salmonella Tennessee (K4643), linked to peanut butter outbreaks, was used. The direct method involves sprinkling NFDM and SiO2 (0.1 or 0.4 g) onto the coupons inoculated with 0.5 mL of Salmonella. The slurry method (0.5 mL culture to 0.4 g powder) gave consistent results, showing lower Salmonella reduction (1.5–1.6 log CFU/cm2) in NFDM and culture alone LMF PBPs. It was chosen for further tests comparing liquid- and plate-grown cultures. Proceeding with the plate-grown cells using the lawn-based methods, temperature and relative humidity (RH) levels were selected to examine the impacts of environmental factors, in addition to comparing nutrient composition of matrices and storage time on the reductions of Salmonella in LMF PBPs. The coupons were stored for seven or 28 days at 30, 50, or 70% RH at 25 or 35 °C and sampled on predetermined days. Lower reductions were observed for Salmonella LMF PBP made using lawn-grown (0.3–2.7 log CFU/cm2) compared to broth (1.0–5.1 log CFU/cm2) for all food matrices. For both culturing methods, Salmonella in LMF PBP with SiO2 (2.7–5.1 log CFU/cm2) reduced significantly (p \u3c 0.05) more than the food matrices (0.7–2.2 log CFU/cm2) and Sal without a matrix (0.3–1.5 log CFU/cm2). The RH levels, temperature, matrix, and their interactions significantly (p \u3c 0.05) affected the reductions of Salmonella. The significantly greater reductions as the RH increased were specifically observed in LMF PBPs with SiO2. Temperature and RH had no significant effect on Salmonella LMF PBPs in NFDM and Sal. However, matrix type and storage days significantly impacted log reductions (p \u3c 0.05) of Salmonella LMF PBP. Salmonella reductions in LMF PBP with PB were significantly (0.5 ± 0.3 log CFU/cm2) lower compared to the reductions observed on other food matrices (1.9-3.6 ± 0.1 log CFU/cm2). The findings indicate that the LMF PBP method produces a stable population of Salmonella, which is important for evaluating cleaning and sanitation interventions where significant log reductions need to be demonstrated. Future research, using the methods established in the present study, should explore the long-term impact of varying environmental conditions, such as fluctuating humidity or cleaning and sanitation, on the persistence of LMF PBPs formed using the slurry method
Using Deep Learning and Two-Photon Excitation Fluorescence Microscopy to Predict Breast Cancer Recurrence and Response to Chemotherapy
No full textAccurate prediction of breast cancer recurrence plays a critical role in guiding treatment decisions, particularly regarding the use of systemic therapy for patients. While genomic assays such as the Oncotype DX Recurrence Score offer valuable prognostic information, they are limited in accessibility and application. The work presented in this thesis explores an imaging-based approach for the prediction of breast cancer recurrence that combines multiphoton microscopy (MPM) with deep learning to classify individual breast cancer biopsy samples by risk of recurrence. Genomic differences in tumors with different recurrence potentials may translate to distinct optical and structural information that can be captured by MPM techniques and subsequently extracted by deep learning models. Deep learning, particularly in the form of convolutional neural networks (CNNs), has proven to be a powerful tool in biomedical image analysis in areas such as image segmentation and disease classification. In this work, a custom CNN was designed and trained on MPM autofluorescence images of breast cancer core needle biopsy samples, using Oncotype DX Recurrence Scores as a ground truth for classification. This model was refined and evaluated on multiple combinations of training inputs through a robust cross-validation approach to ensure consistent performance across the entire dataset. Several combinations of image inputs led to highly accurate classifications, suggesting that the CNN is able to detect complex patterns in the MPM images that correspond to risk of breast cancer recurrence
Dream Eater
No full textThis collection of poems follows a set of fictional children as they try to make sense of a rural Southern town and the gods and disasters that beset it. Emerging from the children’s wanderings are questions, but never answers, about the South, trauma, gender, and religion. The plot of this collection is a loose chiasmus, where the first thing that happens is also the last thing that happens. Everything that takes place leads, both forwards and backwards, to the inevitable flood that occurs in the center of the book. The first section is told from the perspective of the children, who miss their mother and seem to be growing bigger by the second. The second half of the book is narrated by the gods, who re-trace all that has occurred as they try to unzip what caused the flood, what destroyed the children, and who the mother is. dream eater presents the reader with a vision of the world similar to the visual folk art of creators like Howard Finster and Theora Hamblett. There is a sense of uneasiness and unfamiliarity to the work that is sometimes crude, sometimes frightening, but always charged. Like visual folk art, dream eater creates its own vision of the world that rewards the reader who chooses to step inside.
In terms of craft, dream eater contains no periods; just commas and the occasional question mark. The commas help to propel the book forward and point the reader towards the inevitability of the flood. The occasional question punctuates this pacing, bringing to the surface questions about the world that cannot be answered, and answers “we cannot bear to hear.” The syntax is heavily influenced by a sense of orality, while the diction helps conjure another world through unique and at times nonsensical idioms, objects, and strung-together lists. Parallelisms are frequently used to equate disparate things that can’t make sense together but do, a reflection of the children’s conflicting feelings about growing up in the South (“and because none of it added up, and because all of it added up…”). This allows the book to attempt to reach a better understanding of the mother, the town, and the gods, who are all complex and contradictory, evading capture.
Who (or what) is dream eater? I think dream eater is some kind of god, or maybe God, but the more I think about it the more I lose it, which is what, I think, makes them a god to me. All throughout writing this book I’ve had a quote by Carolyn Forché on my mind: “The silence of God is God.” I think this is why the horses bother the children so much. They’re always “just standing there.” The children can’t reach them, like they can’t reach the gods, the mother, or anything. But as the children grow too big–grow enormous, even–their presence itself becomes a kind of question for the world of the book as well as the reader
Sanctuary of the Voiceless: Examining Tik-Tok as a Political Landscape
Get PDFWhile studies of social media as a political landscape often focus on established platforms like Twitter. They neglect emerging spaces like TikTok, the short-form video app, which has become an unexpected hub for political discourse. This study test Melissa Harris-Perry\u27s everyday talk framework to analyze the political utility of this new digital space. Through analysis of 271 posts across TikTok, Twitter/X, and Truth Social, the research reveals how platforms simultaneously enable and constrain political discourse. Findings show verified accounts post political content 3.2 times more often than regular users, while political posts receive 167% more reposts, demonstrating how algorithms amplify certain voices while marginalizing others. The study examines this paradox through cases like #SilentRiot\u27s digital protests and Palestinian journalists using TikTok to counter mainstream narratives, showing how marginalized groups repurpose platforms for resistance despite corporate and state surveillance. As platforms face existential threats from bans and co-optation (exemplified by the TikTok ban debate), the paper argues these digital spaces have become modern infrastructures of liberation that replicate historical patterns of Black political discourse while confronting new challenges of algorithmic bias and platform capitalism. The research demonstrates that TikTok transformation of everyday talk represents both unprecedented opportunities for marginalized communities to shape narratives and new vulnerabilities requiring urgent protection
Summaries of Arkansas Cotton Research 2024
Get PDFPlanted cotton acreage in Arkansas increased in 2024 to 670,000 planted acres, which was 160,000 acres more than in 2023 when Arkansas producers planted approximately 510,000 acres of cotton. A wet spring, and two hurricanes in three weeks in late summer/early fall led to a slight decrease in harvested acres that culminated in a final number of 640,000 (https://www.nass.usda.gov/Quick_Stats/Ag_Overview/stateOverview.php?state=ARKANSAS). Producers harvested 640,00 acres of cotton, which ranked third nationally, behind Texas and Georgia (https://downloads.usda.library.cornell.edu/usda-esmis/files/k3569432s/nk324887m/qn59s0097/cropan25.pdf). The total harvested acreage is the greatest amount since 680,000 acres in 2011. The average cotton yield in Arkansas in 2024 was 1,313 lb lint/acre, which ranked third, behind California and Missouri, respectively. This average yield set an all-time record, surpassing the previous mark of 1,295 lb lint/acre set in 2023 (Fig. 1). Arkansas farmers produced 1.75 million bales of cotton, which also ranked third nationwide and set a new state record