Open Research Oklahoma (Oklahoma State Univ.)
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Biogenic hydrogen production from residual oil in geological carbon storage sites
No full textWe found that the combined supply of protein-rich matter and supercritical CO₂ to petroleum produced water (PW) stimulates the biogenic production of H₂ from dissolved oil hydrocarbons by indigenous microbial communities of oil reservoirs. Our experimental results support the hypothesis that a decrease in pH to acidic levels due to the dissolution of supercritical CO₂ into the aqueous phase and the availability of protein-rich matter, favors the activity of H₂-producing microbial communities over the activity of H₂-using microbial communities. To determine where, when, and how much H₂ could be produced in a depleted oil reservoir co-injected with CO₂ and PW supplied with protein-rich matter, we simulated the biogenic production of H₂ for the Morrow B sandstone reservoir. Our simulation results indicate that 365 – 1925 kg of H₂ could be produced after 100 days of CO₂ and PW co-injection (1.5 kg-CO₂/1.5 kg-PW – 7.5 kg-CO₂/7.5 kg-PW) into a single well of radial flow of uniform porosity and permeability, and that sandstone reservoirs are more suitable than carbonate reservoirs to produce H₂ by the proposed stimulation method. Simulations were conducted using our own TOUGHREACT module called CO2Bio. CO2Bio simulates the multiphase bio-geochemical reactive transport of CO₂-CH₄-H₂-H₂S mixture gases in geological carbon storage sites. To determine the effect of permeability heterogeneity on the biogenic production of H₂ by the proposed stimulation method, we incorporated permeability heterogeneity into the model consisting of a single well of radial flow. This task was achieved by measuring the permeability of four core samples of the Morrow B sandstone reservoir, and by applying a kriging geostatistical interpolation method. Simulation results indicate that heterogeneity reduces the amount of H₂ production by the proposed stimulation method, and that larger amounts of H₂ are produced in zones of high permeability than in zones of low permeability. An additional simulation was conducted placing multiple wells across the whole reservoir. After 100 days of injecting 5 kg-CO₂/5 kg-PW – 10 kg-CO₂/10 kg-PW, H₂ productions was 3,712 kg – 13,489 kg of H₂. Overall, the results indicate that biogenic H₂ production in geological carbon storage sites is feasible and a function of petrophysical, geochemical, and microbiological factors
Development of a small-scale, modular and portable, kerosene-nitrous oxide liquid rocket ground test rig
No full textThis thesis presents the design and evaluation of a small-scale modular liquid bipropellant rocket engine ground test stand. The motivation is to develop a liquid bipropellant rocket engine test stand for development of component-level technologies, materials, and manufacturing processes. The driving requirements are to develop a system that can accurately measure the performance of a rocket engine with thrust up to 500 lbf using safe storable propellants in a configuration representative of industry applications. Key features of the test stand include pressure-fed propellant feed systems, single-element coaxial shear injector, and ablative chamber liner. The evaluation of the test stand involved static and dynamic tests, which included procedure development and test execution for cold flow testing, as well as hot fire tests. Tests determined engine thrust, specific impulse, and overall performance. Work performed includes system level requirements analysis, parametric cycle design, and individual component level design of the propellant feed system, injectors, combustion chamber, nozzle, and structural supports of the test stand. Key results of this study include measured thrust levels (140 to 290 lbf) over a range of chamber pressures (300 to 150 psi), and total propellant flow rates (1.1 to 0.9 lbm/s). Additionally, the successful design and testing of a modular and portable test stand brings lessons learned that can be used for future research and educational purposes, and for further optimization of the system for specific applications. The impact of this study is developing a broadly applicable, low cost and complexity test apparatus to enable hardware development and further researc
The interwoven experience of body image and racial/cultural identity development among women of color
No full textDespite the vast amount of body image research, there still is a lack of exploration and understanding of how women of color experience their bodies. Therefore, due to the lack of research, mental health clinicians might not be able to appropriately support women of color who have body image concerns. As a result, the current study seeks to explore sociocultural factors that may influence how women of color feel about their bodies. In addition, due to women of color’s intersecting identities, the study seeks to expand beyond the current literature by exploring more in depth the influence body image and racial/cultural identity may have on one another. For the study, 11 participants were recruited and completed a semi-structured interview. Thematic analysis was completed to explore themes amongst the data. Four themes were found among the data: exploring racial/cultural groups; conflicting messages; systemic influences; and family influences on body image. Furthermore, the results suggest that body image and racial/cultural identity influence one another and should be addressed when working with women of color and body image concerns
Regulation and function of the Dictyostelium atypical MAP kinase Erk2
Get PDFIn eukaryotic cell signaling, MAPKs mediate cellular processes like cell growth, differentiation, and movement. In Dictyostelium discoideum, a social amoeba, there are only two MAPKs, Erk1 and Erk2. Erk1 is a typical MAPK responsible for developmental kinetics and aggregate size while Erk2 is an atypical MAPK required for chemotaxis, multicellular development, and the translocation of GtaC, a key transcription factor in developmental gene expression. Little is known about the function and regulation of atypical MAPKs in other organisms but in D. discoideum, Erk2 is activated within 30 seconds after stimulation by a chemoattractant. Erk2 function is required for a burst of Erk1 activation in a secondary response to chemoattractants. To test regions in the Erk2 protein that may be important for regulation and specificity, chimeric proteins have been made with Erk1. Through this study we have discovered that the C-Terminal end of Erk2 is likely important the down regulation of Erk2 activation. Chimeras with junctions near the middle of the MAPKs can partially rescue growth on bacterial lawns. Atypical MAPKs have a conserved C-terminal motif (CTM) not found in other MAPKs. While not essential, the CTM is required for most Erk2 functions except for growth on bacteria but the CTM motif does not confer Erk2 function to the Erk1 MAPK. The phosphorylation of a kinase dead Erk2 mutant (Erk2ᵏᵈ) is phosphorylated after cells have been stimulated by a chemoattractant suggesting that Erk2 does not autophosphorylate and the existence of an upstream protein kinase that regulates Erk2 activity. Current investigation of possible upstream protein kinases responsible for Erk2 activation (Pak (PakE, & PakG) and Fray (Fray1, & Fray2) proteins) are underway. PakE disruption mutants have shown a delay in development from the mound to slug stage. Preliminary data suggest that Fray1 might also be important for this same stage in development. These results indicate that PakE and Fray1 cannot be the sole upstream activators of Erk2, but this does not exclude these kinases from having a potential role upstream of Erk2 during multicellular stages of development
Mechanistic basis for stress sensing by the Bacillus subtilis stressosome
No full textBacillus subtilis uses pseudo-icosahedral cytoplasmic multiprotein complexes called stressosomes for sensing a variety of environmental stressors. The stressosome complex is assembled from two types of core proteins: the RsbRs (RsbRA, RsbRB, RsbRC, RsbRD, and YtvA) and RsbS. The stressosome is thought to sequester the RsbT protein to prohibit the σᴮ stress response; stress causes RsbT release and subsequent response activation. It is not known exactly how stressosome proteins sense stress to initiate activation of σᴮ. A longstanding model invokes the primary role of RsbR proteins as sensors that are organized by RsbS as a scaffold. Therefore, we sought to determine the function of individual amino acids in the putative N-terminal stress-sensing domain of RsbRA by systematic alanine scanning, hypothesizing that they might have roles in stress sensing. We found that RsbR proteins are robust to mutation and that amino acid substitutions in the N-terminal domain of RsbR can adjust the magnitude and timing of the response, but generally did not abolish stress sensing. Moreover, here we report genetic evidence that contradicts the canonical stressosome model. In the existing model, a strain lacking both RsbRs and RsbS would be expected to constitutively activate σᴮ, as RsbT would no longer be sequestered. Surprisingly, a strain deleted for all rsbRs and rsbS showed σᴮ activity that remains inducible by environmental stressors, although the response is stronger and longer-lived. Furthermore, deletion of rsbT in a rsbRs-rsbS deletion background completely abolished σᴮ activation, while expression of rsbT from an IPTG-inducible plasmid restored the σᴮ response, consistent with RsbT having a critical stress-sensing role. We also examined the single-cell stress response in B. subtilis cells lacking both RsbRs and RsbS protein under constant exponential-phase conditions using a microfluidic device. We observed that stress leads to the activation of B in individual cells with a sustained pulsatile response, consistent with previous results; moreover, different stressor concentrations modulate the average response magnitude. Collectively, our results provide strong evidence in support of a new model in which RsbT acts as a major sensing protein, while stressosomes modulate the strength and timing of the σᴮ response
Poultry parasites
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
Investigating the influence of dietary pulse consumption on epigenetic biomarkers of colorectal cancer risk
No full textDiet and lifestyle factors play a significant role in colorectal cancer risk by influencing the epigenetic regulation of tumor suppressor genes. While dietary components, such as pulses, are recognized for their chemo-preventative potential, further research is needed to understand how they modulate epigenetic gene expression to protect against colorectal cancer. Pulses are rich in fiber and phytochemicals, making them promising candidates for dietary interventions. This study aimed to determine if sufficient quantities of high-quality human genomic DNA (gDNA) could be extracted from fecal samples to evaluate how pulse consumption impacts tumor suppressor gene expression. Fecal samples were collected from 23 healthy postmenopausal women (aged 45–70) before and after consuming 100 g of pulses daily for nine months. Total gDNA was extracted using the Quick-DNA Fecal/Soil Microbe Kit, with its concentration and integrity assessed via UV spectrophotometry and agarose gel electrophoresis. The proportion of human DNA in total gDNA was determined using the Femto DNA Quantification Kit. The expression of the tumor suppressor gene N-Myc Downstream-Regulated Gene 4 (NDRG4) was analyzed through RT-qPCR to assess the sufficiency of the extracted human DNA for evaluating diet-mediated gene expression changes. Results showed that human DNA accounted for ≤1% of total fecal gDNA, resulting in limited detectability of NDRG4. Expression was measurable in 21 of 23 participants at all time points, but changes following pulse consumption were highly variable. These changes appeared to correlate with altered acetic acid production. However, due to its low expression levels and inconsistent detectability, NDRG4 is not an ideal biomarker for evaluating the efficacy of dietary interventions like pulse consumption for colorectal cancer chemoprevention. The study concluded that fecal samples are a viable non-invasive approach for dietary chemoprevention research. Future studies should explore the effects of pulse consumption on NDRG4 methylation status to provide a clearer understanding of its epigenetic role in colorectal cancer prevention
Using harvest aids in Oklahoma grain sorghum production
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
You and 4-H Club work
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
Children appear to influence TA eating habits, especially dietary quality
No full textBackground: Chronic diseases occur at higher rates among tactical athletes (TAs) than US averages. Chronic disease prevalence continues to rise despite existing nutrition interventions. Children have emerged as a possible influence on TA nutrition. Civilian studies reveal a bidirectional relationship such that parents and children influence one another’s eating habits. Because TAs have a rigorous schedule, it is suspected that they cater to children’s food preferences as compensation. Thus, the purpose was to determine whether children act as gatekeepers to TA eating habits and nutrition.Methods: This cross-sectional study included an online survey completed by a convenience sample of TAs and significant others. Survey questions included demographics, employment status, relationship and child information, family dynamics, type of TA, perceived nutrition knowledge and attitudes, family eating patterns and child influence, and dietary quality (mini-EAT score) of themselves and their child. Statistical analyses included descriptive statistics, t-test, ANOVA, and Pearson correlations.Results: Total healthy eating readiness score was moderately and negatively associated with number of driving children (r=-0.34). TA mini-EAT total score was moderately and negatively associated with number of children (r=-0.38), perceived level of limited variety in food because of the child (r=-0.33), and perceived limit of healthy food consumption because of child (r=-0.46). TA mini-EAT total score was moderately and positively associated with child mini-EAT total score (r=0.50). Child total mini-EAT average score was 30.8/72±5.9 per significant other and 29.6±7.1 per TA. TA total mini-EAT average score was 32.0±6.6.Conclusions: Children influence TA eating habits and dietary quality. Thus, practitioners should not ignore the family and consider improving children’s nutrition as a means of improving TA eating habits and dietary quality.Lew Wentz FoundationNutritional Science