Open Research Oklahoma (Oklahoma State Univ.)
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Oklahoma agricultural soil test summary 2018-2022
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
Analysis of the role of methyl-accepting chemotaxis proteins and the GGDEF motif in the signal transduction chain of photoactive yellow protein
No full textMany bacterial genomes encode photoreceptors which detect illumination and send signal cascades to response-regulated proteins to illicit physiological responses. The Photoactive yellow protein (PYP) is a known photoreceptor which has been characterized to illicit a range of biological responses in different bacteria upon blue light illumination indicating diversity in its downstream signal transduction chain. Such responses include photoregulation of photo-protective pigment biosynthesis, photoregulation of biofilm formation, and negative phototaxis. We performed bioinformatics analyses of PYP homologs to identify both recurring genes within the same predicted operon as PYP and protein domains occurring in multidomain PYPs to further understand possible biological functions of PYP and its signal transduction pathways. Two identified genes of interest include the PYP-MCP fusion protein and the GGDEF motif as it relates to the signal transduction chain of PYP.The domain structure of the PYP-MCP fusion protein suggests that it is sensitive to blue light illumination via its PYP domain and that it controls motility via its methyl-accepting chemotaxis protein (MCP) moiety, leading to the hypothesis that this protein triggers negative phototaxis. To further investigate the PYP-MCP fusion protein and its signal transduction chain, we experimentally analyzed the Nitrincola alkalilacustris sp., which contains a multidomain PYP, to test the prediction that N. alkalilacustris sp. containing the MCP-PYP fusion protein will respond to a stimulus of blue-light and undergo negative phototactic movement due to the downstream signaling from the PYP to the methyl accepting chemotaxis protein which controls the MCP moiety.Using prior studies as well as bioinformatics research the GGDEF domain is suggested to be a key player in regulating biofilm formation upon light illumination triggered by the pyp gene. The GGDEF proteins have been characterized to convert GTP into cyclic-di-GMP which is needed to synthesize exopolysaccharides in biofilm formation. Therefore, the domain structure of tis GGDEF motif coupled with the PYP suggests that it is sensitive to light illumination via its PYP and it controls the regulation of biofilm formation via its GGDEF protein, leading to the hypothesis that this multi-domain protein triggers the regulation of biofilm formation. To investigate this GGDEF motif as a multi-domain PYP we experimentally analyzed Massilia albidiflava and Massilia plicata species containing the GGDEF motif in a multi-domain PYP using Idiomarina loihiensis as an experimental control as it has been described to have biofilm formation regulation via they PYP to test the prediction that, M. albidiflava and M. pilcata containing the PYP-GGDEF motif will respond to the blue-light stimulus and undergo photo-regulation of biofilm formation due to downstream signaling from the photoactive yellow protein to the GGDEF motif in the multidomain PYP.Since PYP functional photocycle is initiated by photoisomerization of its p-coumaric acid (pCA) chromophore, we used the addition of pCA to indicate the blue-light illumination response to be triggered by the PYP signaling due to PYP being the only photoreceptor to use pCA as its key component in photoisomerization of its chromophore to initiate an active response. Upon the addition of pCA within the media used to test phototaxis within N. alkalilacustris sp, there appears to be a restoration in positive phototaxis, which needs further biological replicates to be a conclusive result. Furthermore, for the analysis of biofilm formation there were inconclusive results for M. albidiflava while the addition of pCA did not appear to have an effect on M. plicata. Upon further investigation of M. plicata there does however appear to be a light effect which causes a decrease in biofilm formation upon light illumination, again further biological replicates are needed to confirm these results. The addition of a trans-locked pCA chromophore is also needed to determine this result is due to the PYP
Participants in community and economic development
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
Experimentally validated heat exchanger refrigerant charge model and optimization of refrigerant charge for a heat pump
No full textRefrigerant charge affects the efficiency, capacity, and reliability of a heat pump, and incorrect charge can lead to increased energy consumption and decreased performance as well as potential damage to the system. Furthermore, refrigerant charge has an environmental impact, with high Global Warming Potential (GWP) refrigerants contributing to climate change. The HVAC&R society is adopting low-GWP refrigerants to alleviate the concern. For these reasons, accurate prediction of refrigerant charge is vital in designing heat pumps, particularly for low-GWP refrigerants; this charge prediction is done by charge models.Meanwhile, existing charge models are limited in their charge prediction accuracy due to uncertainty in void-fraction models the charge models rely on for charge prediction. Experimental charge validation data can improve the accuracy of the charge model, but such data for low-GWP refrigerant charge is rare in the open literature.The goal of this study is to address the issue by improving the accuracy of charge prediction; that is done by creating a high-accuracy charge model that is verified by experimental charge validation data. To gather this experimental charge data, a novel charge measurement method and charge measurement facility for measuring charge is created, resulting in high-fidelity experimental charge data for heat exchangers across various operating conditions of heat pumps. This database includes multiple refrigerants, including low-GWP refrigerants, R1234yf and R468C, and additional R410A as a reference. Employing this experimental data, a high-accuracy charge model is developed and validated, which is used to optimize the charge and cooling capacity of a heat pump simultaneously on a developed multi-objective optimization framework
Blocking the acquisition of the essential iron nutrient in Pseudomonas aeruginosa
No full textThe Gram-negative opportunistic pathogen Pseudomonas aeruginosa (Pa), declared by the World health organization as a “Priority 1: Critical Pathogen," needs immediate new tactics for developing antipseudomonal treatments. Pa uses mechanisms to acquire ferric, heme (Hm), and ferrous iron from human hosts to survive, colonize and cause infection. Efforts have been made to create siderophore blockers to inhibit the ferric acquisition pathway of Pa. However, a lack of inhibitors exist to block the remaining Hm and ferrous pathways. We developed a targeted high throughput screening (HTS) approach and identified molecules that specifically inhibit the Hm and ferrous acquisition systems. We screened Pa against a small molecule library under three growth conditions. The iron source was the only variable, and each condition served as a counter screen for the other. We were able to identify econazole, bithionate, as growth inhibitors in Hm and oxyquinoline sulfate in ferrous iron. When exposed to meropenem, a commercial antipseudomonal, there was no interference in activity with some increased antipseudomonal activity. We examined each molecule's mechanisms of action to further understand interactions between Pa and the molecules. We also examined the effects of the compounds in the presence of biofilm and drug-resistant clinical isolates both in shaking and static conditions. The majority of the compounds showed specific activity in the respective iron sources against the isolates. Further analysis is needed to examine the mechanisms of action though initial experiments indicate that each compound has unique targets. In conclusion, we presented proof-of-concept of a successful targeted HTS, identified effective iron acquisition inhibitors against clinical isolates and started initial experiments to characterize the mechanisms of action of the newly identified inhibitors
Bridging the gap: An ecological and morphological analysis on the california margin expanding spore into the infaunal realm
No full textBenthic foraminifera have been widely used by paleoceanography to assess changes in ocean conditions over geologic time. The distribution, abundance patterns, and morphological characteristics of modern benthic foraminifera can serve as modern analogs that allow interpretations within the paleo-realm. This study seeks to explore the ecological significance of pores in epifaunal and infaunal benthic foraminifera as a biological proxy for deep-sea paleo-oxygen. Expanding on the previous work of Rathburn et al., 2018, this study conducts an ecological analysis of four sites within the Southern California Bight. Finding appreciable amounts of shallow infaunal and epifaunal species commonly found at the boundary of oxic and dysoxic waters consistent with the TROX model. With bottom water oxygenation spanning 0.533ml/l to 1.274ml/l, this environment supported populations of Bolivina spissa, Rosalina bradyi, Hoeglundina elegans, along with many taxa from the Reophax and Globobulimina genera. Selecting the most abundant infaunal species, B. spissa, SPORE analysis was performed alongside living and dead populations of Cibicidoides wuellerstorfi. Similar trends to those published in Rathburn et al. (2018) in both species. Variations in SPORE between living and dead individuals varied only slightly, indicating that at least locally, dead individuals can reflect bottom water conditions in a similar way to living individuals. These findings suggest that the SPORE methodology is effective for studying both living and dead populations of C. wuellerstorfi.It was found that B. spissa show a similar, though less pronounced, inverse relationship to bottom water oxygenation consistent with C. wuellerstorfi, fitting expectations as a shallow infaunal species, much more tolerant to low oxygen conditions. Downcore, however, did not follow our expectations. SPORE values decrease with increasing depth within the sediment. Specific pore water geochemistry was not available for this study and could hold key insights into these observed trends. Further research is currently being conducted examining B. spissa both downcore and on average across a wider oxygen gradient. These works will continue to bolster the established C. wuellerstorfi data and begin to expand on these initial insights observed in this study
Learning about research writing across the disciplines: Pathways, problems, and possibilities
No full textEnglis
Exploring race-talk at a Christian college: A case study
No full textResearch suggests that the cultural homogeneity of Christian college campuses presents challenges for people of color to navigate. White cultural norms influence attitudes about race. The way people at an institution talk about race reflects the institution’s campus racial climate. The purpose of this study was to explore how members of a Christian college, associated with a formal process of reviewing racism on campus, talk about race. This case study, conducted at a small, private, Christian university was about the relationship between race-talk (Sue, 2005), campus racial climate (Hurtado et al., 1998) as well as identifying religious forms of race-talk. Through observations and interviews participants dialogued about race in order to create change on their campus. Results from the study indicate that administrators, staff, faculty, and students described a culture where silence about race perpetuated racism and where participants wanted to talk about Whiteness as a system of oppression. Implications for research, theory, and practice are discussed, including ways in which members of colleges can participate in sense-making process to discuss racism on their campus
Search for the standard model Higgs boson in the ZH → vvbb channel in 9.5 fb⁻¹ of pp[over ¯] collisions at √s = 1.96 TeV
No full textWe present a search for the standard model Higgs boson in 9.5 fb⁻¹ of pp[over ¯] collisions at √s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. The final state considered contains a pair of b jets and is characterized by an imbalance in transverse energy, as expected from pp[over ¯] → ZH → νν¯b¯b production. The search is also sensitive to the WH → ℓνb¯b channel when the charged lepton is not identified. The data are found to be in good agreement with the expected background. For a Higgs boson mass of 125 GeV, we set a limit at the 95% C.L. on the cross section σ(pp[over ¯] → [Z/W]H), assuming standard model branching fractions, that is a factor of 4.3 times larger than the theoretical standard model value, while the expected factor is 3.9. The search is also used to measure a combined WZ and ZZ production cross section that is a factor of 0.94 ± 0.31 (stat)± 0.34 (syst) times the standard model prediction of 4.4 pb, with an observed significance of 2.0 standard deviations.Physic
Integrated deep learning based online layer-wise surface prediction of additive manufacturing
No full textAdditive manufacturing (AM) has been growing tremendously through its introduction into various industries over recent years, because of its capability of fabricating objects with complex designs. Despite its great successes, AM still has to deal with its main challenge, which is the quality assurance of the printed object. Although extensive studies have been conducted, this technology still has several critical gaps. Due to layer-wise fabrication, one important aspect of quality assurance is to capture the surface morphology of the layer being printed online, which can help to better understand the process dynamics and greatly benefit the promotion of in-process quality control. Thus, this study aims to develop an integrated deep-learning model to achieve online layer-wise surface prediction of AM. The proposed deep learning model integrates the convolution autoencoder for surface representation learning and a long short-term memory (LSTM) network for layer-wise prediction. The proposed method is validated by a real-world case study in a common AM process, fused filament fabrication (FFF). The comparison with the benchmarks demonstrates that the developed method has great potential for online layer-wise prediction in AM