Open Research Oklahoma (Oklahoma State Univ.)
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Crianza compartida: El papel único de los padres
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Role of friendship networks (social connectedness) in the municipal bond market
No full textUsing a novel dataset from Facebook, I examine how the social connectedness and word-of-mouth communications affect municipal bond market outcomes. I conjecture that higher social connectedness between counties within a state and higher social connectedness within a county lead to lower municipal bond yields. Specifically, I hypothesize that the risk of municipal bonds is expected to be moderated by the social connectedness because of two plausible reasons. Firstly, social connectedness may function as a mechanism that eliminates information asymmetry between investors and issuers by providing information of municipal bond issuers. Secondly, social connectedness may function as a mechanism that imposes a greater cost and harsher punishment for opportunistic and unethical behavior. I empirically assess the validity of these arguments in this study. My findings confirm that bond yields are lower for municipalities and local governments when social connectedness between counties within a state and higher social connectedness within a county are higher. I also show that the effect of social connectedness on municipal bond yields is driven by within-state social connectedness. This paper provides empirical evidence in support of the argument that the risk associated with municipal bonds is lower when local governments and other municipal bond issuers are located in counties or regions with high social connectedness
Enhancing spatial disorientation training in aviation: Simulator development and validation for future pilots
No full textSpatial disorientation significantly contributes to general aviation accidents, often leading to fatal outcomes. Traditionally, training to combat spatial disorientation involves in-flight exercises or ground-based simulators. With the emergence of the advanced air mobility sector, a surge in pilot demand is anticipated, aligning with general aviation's regulatory landscape. This context heightens the risk of spatial disorientation, underscoring the urgency for effective training solutions. This thesis presents the enhancement and application of a traditional motion simulator to create immersive spatial disorientation training scenarios. The project's cornerstone was the integration of advanced graphic enhancements and comprehensive control over the simulator's hexapod motion base, aimed at authentically replicating disorienting illusions. Four particular illusions—pitch-up, graveyard spiral, runway width, and general motion decoupling—were selected for implementation, each designed to effectively challenge and train pilot responses. Experimental evaluations involving four pilots assessed the efficacy of the simulator modifications, revealing significant perceptual impacts during the pitch-up illusion scenario, congruent with anticipated responses to such illusions. In contrast, the modifications tailored for the graveyard spiral illusion proved too subtle to provoke the expected pilot reactions, suggesting a need for further refinement. The visual illusion scenario, the runway width illusion, proved effective in inducing disorientation. Data from the motion decoupling illusion revealed mixed effects on pilot performance, suggesting variability in individual training outcomes. Subsequent scrutiny of pilot data illuminated several critical areas for improvement, such as inconsistent and aggressive pitch control and an ineffective graveyard spiral illusion. Enhancements to address these deficiencies were initiated, yielding encouraging outcomes through the application of the Brunner motion simulator for the graveyard spiral illusion. Concurrently, modifications to the yoke controls were introduced, aiming to integrate force feedback mechanisms for a more realistic flight experience. This research underlines the potential of custom simulator modifications in enhancing pilot training against spatial disorientation, offering a valuable tool for addressing a critical safety challenge in aviation training
Exploring affordable solutions for orthopedic medications: A comparative study of Mark Cuban Cost Plus drug company (MCCPDC) and medicare
No full textBackground: Healthcare spending on medications has continued to rise over the years, presenting a dilemma with affordable medications, notably in the field of orthopedics. To combat this issue, the Mark Cuban Cost Plus Drug Company (MCCPDC) platform has been established as an alternative to lower the financial burden placed on patients. The goal of this study is to assess the differences between MCCPDC and Medicare Part D orthopedic medication pricing.Methods: We performed a cross-sectional analysis on the price difference on gout, muscle relaxants, pain and inflammation medications, as well as steroids between MCCPDC and Medicare Part D 2021 spending data. Prices, including shipping fees, were included for tablets and capsules in the minimum quantity (30ct) and maximum quantity (90ct). The unit costs, and total savings, and standardized unit prices for 30ct and 90ct prescriptions were calculated and compared between MCCPDC and Medicare medications.Results: Our study sample comprised 24 medications for comparison after exclusions within four different MCCPDC categories. Medicare’s expenditure for these medications totaled 800.10 cumulative cost reduction in favor of Medicare. In contrast, 90ct medications showed 15/24 medications with MCCPDC cost savings. The cumulative cost difference was $309.1 million in favor of MCCPDC.Conclusion: Our findings illustrate large potential savings observed for many common orthopedic 30ct and 90ct medications, with a more substantial cumulative cost difference observed in 90ct medications. Hence, our study highlights the potential benefits of MCCPDC in optimizing Medicare expenditures for covered drugs, potentially enhancing cost-efficiency in healthcare. A careful analysis of specific prescribed medications are needed in order to capitalize on the potential savings
Illness uncertainty trajectories among parents of children with atypical genital appearance due to differences of sex development
No full textObjective: The present study aimed to identify distinct trajectories of parental illness uncertainty appraisals among parents of children born with atypical genital appearance due to a Difference of Sex Development (DSD) over the first year following diagnosis. It was hypothesized that four trajectories would emerge, low stable, high stable, decreasing, and increasing profiles, and that key demographic, familial, and medical factors would predict these trajectories. Methods: Participants included 56 mothers and 43 fathers of 57 children born with moderate to severe genital atypia. Participants were recruited from eleven specialty clinics across the United States. Growth mixture modeling (GMM) approaches, controlling for parent dyad clustering, were conducted to examine profiles of illness uncertainty ratings over time. Results: A three-class GMM was identified as the best fitting model with freely estimated intercept variances. The three profiles were labeled as “Moderate Stable” (63.8%), “Low Stable” (20.9%), and “Recovering” (15.3%). Those in the Recovering class were less likely to have a Congenital Adrenal Hyperplasia diagnosis (versus other conditions) and may also be more likely to report higher anxious symptoms at baseline. Conclusions: Findings highlight the nature of parents’ perceptions of ambiguity and uncertainty about their child’s diagnosis and treatment shortly following their child’s birth. Future research is needed to better understand how these trajectories might shift over the course of the child’s development. Tailored, evidence-based interventions are needed to support families coping with uncertainty while raising a child with chronic health needs and bolster long-term family functioning
Structural composites from post-consumer polypropylene carpets and different polyolefin resins
No full textCarpets are heterogenous in nature and challenging to recycle due to their complex structures. Annually, they account for over 3 million tons (approximately 1.2%) of Municipal Solid Waste (MSW) in the U.S., with less than 10% being recycled. Most of this waste ends up in landfills, with no viable solution to prevent it. The most recycled plastic is polyethylene terephthalate (PET), which typically comes from plastic bottles, which are already easily recycled and even circularly used to make new bottles. In contrast, materials like bottle caps and retail bags, typically made of polyolefins, are often mixed with other materials such as labels, ink, and remnant products, which creates challenges for separation and recycling. A circular recycling approach for carpets and mixed polyolefins resins has not been successful. Conventional recycling methods tend to focus on economically viable plastics, such as nylon carpets and partially cleaned plastic bottles. However, these methods often recycle only the carpet tuft and the main body of the bottle, leaving the carpet backing and other components to be discarded in landfills. A more comprehensive solution to these challenges is to use entire carpets, along with bottle waste polyolefins, to produce functional composites. This approach not only maximizes material recovery but also reduces waste sent to landfills.This thesis focuses on a method developed to fabricate recycled composites from whole post-consumer polypropylene carpets combined with different recycled polyolefin resins through compression molding. The mechanical properties of these composites were evaluated using three-point flexural bend and creep compliance tests. The optimization involved careful screening of molding parameters to identify the best temperatures and resin-to-carpet ratios, maximizing mechanical properties while minimizing the use of resins and additives. This sustainable approach not only diverts carpet waste from landfills but also reduces the carbon footprint of plastic materials, offering a practical solution to a growing environmental challenge
Potential compounding nature of ACEs and diabetes on maternal depression: An examination of the Behavioral Risk Factor Surveillance System
No full textBackground: Perinatal depression (PD), defined by the American College of Obstetrics and Gynecologists (ACOG) as a depressive episode during pregnancy and up to one year after giving birth, has significant implications. ACOG recognizes that a personal history of depression, at any point in one's life, is a suscetibility factor for PD. An additional risk factor of PD is adverse childhood experiences (ACEs), which have also been linked to diabetes in adulthood. Given the potential compounding impact of ACEs and diabetes on maternal depression, the primary objective of this study is to investigate the association between any depression diagnoses among pregnant women by diabetes status in the context of ACEs.Methods: To examine the relationship between diagnoses of depression throughout one’s lifespan, among pregnant individuals with ACEs and diabetes, we performed a cross-sectional analysis using data from the Behavioral Risk Factor Surveillance System. We used a logistic regression model to examine the interaction of ACEs and diabetes on diagnosis of depression among pregnant women.Results: Results showed that compared to pregnant without diabetes or a history of ACEs, the likelihood for depression was significantly increased among the following groups: Women with 1-3 ACEs, but no diabetes (OR: 1.81; 95%CI: 1.08-3.03), women with 1-3 ACEs and diabetes (OR: 4.06; 95%CI:1.06-15.58), 4+ ACEs/No Diabetes (OR: 5.94; 95%CI: 3.62-9.75), 4+ ACEs/Gestational Diabetes (OR: 3.04; 95%CI: 0.62- 14.99), and were highest among those with 4+ ACEs/Diabetes (OR: 16.94; 95%CI:3.42-83.94). No significant difference in the rate of depression history was found in women with no ACEs having diabetes and was lower among those with gestational diabetes and no ACEs.Conclusion: We found a significantly increased risk for maternal depression in pregnant individuals with 4+ ACEs and diabetes, demonstrating a dose-response relationship. In light of these results, obstetricians and other maternal healthcare providers should obtain a thorough social history including an ACEs questionnaire. Given the prevalence of perinatal depression, we recommend increasing access to mental health services for pregnant individuals with ACEs. Further, we recommend the promotion of protective and compensatory experiences (PACEs) during childhood to reduce the downstream effects of ACEs
Microscale evaluation of ionic liquids and alternative fluids as potential working fluids in enhanced geothermal systems
No full textEnhanced Geothermal Systems (EGS) harness subsurface heat from hot dry rocks through engineered and natural fractures, relying on the fracture hydraulic conductivity and properties of the circulated working fluid to optimize heat recovery. In general, fractures with higher hydraulic conductivity tend to allow more fluid flow which can lead to limited heat extraction from only a small portion of the EGS. This channelized flow causes thermal short-circuiting, a common issue that negatively impacts the overall heat extraction from EGS and thus the economic viability of the project. To address this, the study evaluates the flow behavior of Ionic Liquids (ILs) and Alternative fluids and their potential to mitigate flow channeling in EGS using a microfluidic setup. The ILs include 1-butyl-3-methyl-imidazolium bromide ([bmim][Br]), 1-hexylpyridinium bromide ([hPy][Br]), 1-hexylpyridinium tetrafluoroborate [hPy][BF₄] while the alternative fluid consists of a water-based fluid (WBF-2) and an oil-based fluid (OBF-1). Flow experiments were conducted using a microchip to simulate flow through microchannels in EGS, utilizing a variety of fluid samples, including DI water, and different concentrations of the ILs. Furthermore, the study investigated the high-temperature flow behavior of [bmim][Br], WBF-2, and OBF-1 at 18 oC, 50 oC, and 80 oC, comparing it to the performance of the conventional EGS working fluid (DI water) under the same test conditions. The results show that [bmim][Br] and OBF-1 can adjust their rheological properties in response to localized temperature changes, which may enable them to selectively traverse higher temperature flow paths with minimal resistance. Thus, eliminating flow shortcuts through in-situ fracture conductivity tuning. The study also explores the reversibility of the proposed fluids to assess the feasibility of utilizing the fluids as intermediate remedial working fluids to potentially reduce costs. The findings reveal that the pressure differentials before and after the flow of the proposed fluids across the microchannels remained largely unchanged, suggesting that the proposed fluids did not significantly alter channel conductivity. This research provides valuable insights into the flow behavior of these fluids in microchannels, which is crucial for optimizing heat recovery in EGS and advancing sustainable, cost-effective geothermal operations
Evaluating the impact of redox potential on growth capacity of anaerobic gut fungi
No full textAnaerobic gut fungi (AGF), members of the phylum Neocallimastigomycota, play a key role in plant biomass degradation in the alimentary tracts of herbivores. These fungi could potentially play a role in biofuel production, a process that would require fungal growth at a large scale. Understanding the aerotolerance abilities of AGF is essential to the scaling of this process. AGF are strict anaerobes, a trait regarded as an adaptation for survival in the oxygen-devoid herbivorous gut, however, some studies have shown that multiple AGF taxa could survive transient exposure to oxygen. This study evaluated the capacity of four genera of AGF to survive at three different redox potentials (-200mv, -100mV, and 0mV). Redox potential was controlled by varying the concentration of reductant (cysteine hydrochloride), and growth was measured by quantifying gas accumulation in the headspace. All strains tested exhibited growth at -200mV and -100mV, while no growth was observed at or above 0mV. Our results establish an upper limit for AGF growth under different redox potentials, indicate a similar response of multiple AGF taxa to redox potential variation, and suggest that loss of the ability to grow under high redox conditions (0 mV and above) is a common ancestral trait in the phylum NeocallimastigomycotaMicrobiology and Molecular Genetic
Sensor-based bermudagrass yield prediction models using random forest algorithm in Oklahoma
No full textCurrent available direct (i.e., clipping, drying, and weighing) and indirect (i.e., sward-height-based grazing sticks and rise plate meters regression models) forage biomass estimation methods are prohibitive to producers because they are labor-intensive and time-consuming. Thus, producers rely on inaccurate visual biomass assessment to estimate cattle stocking rates, leading to economic losses due to over or undergrazed pastures. Current literature states that (i) machine learning algorithms, such as random forest regressors, are promising agricultural modeling techniques, and (ii) proximity and multispectral sensors can be employed to predict biomass autonomously and fast. This research aimed to develop bermudagrass biomass prediction models powered by the random forest regressor employing laser, ultrasonic, multispectral sensors, precipitation, and N fertilization as input features. The prediction models were developed based on a dataset composed of six different bermudagrass cultivars (i.e., Goodwell, Greenfield, Midland, Midland 99, Ozark, and Tifton 44) managed with four N rates ( 56, 112, 168, 224 kg of N ha⁻¹) at four different Oklahoma locations (Chickasha, Haskell, Lane, and Perkins, OK) collected at 2, 4 and 6 weeks of bermudagrass regrowth (WOR) and at two consecutive growing seasons (2018 and 2019). The 4 WOR, all-features, all-cultivars model, split with an 80-20 proportion (training and validation), had the highest performance (R² = 0.8, MAPE = 24.82%, RMSE =0.93 Mg ha⁻¹), with the laser having the highest feature importance score (65.5%). However, cultivar-specific models trained only associating NDVI, precipitation, and N rates, which are commercially adapted versions, showed that the Greenfield cultivar benefited from removing laser and ultrasonic readings from the training dataset, achieving R² = 0.83, MAPE = 27.24%, RMSE = 0.79 Mg ha⁻¹. Overall, the random forest regressor, proximity, and multispectral sensors proved to be efficient tools for developing effortless and efficient models to predict bermudagrass biomass yield in Oklahoma accurately