UARK (University of Arkansas )
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Agricultural Producer and Non-Producer Perceptions of Crop Residue Burning: A Focus on Arkansas
Get PDFAgricultural producers adopt management practices that positively and negatively affect the lives of non-producers in their communities. CRB has important environmental and human health implications, and local non-producers might have different perceptions and attitudes from agricultural producers about crop residue burning. In this paper, we use a multi-stakeholder approach to study the issue of crop residue burning (CRB). Survey data were collected from a sample of producers in Arkansas who burn crop residue and a sample of non-producers who resided in the same counties as the producers. Non-producers may not be willing to compensate producers at an amount that would reduce the use of CBR. Non-producers do not fully understand some of the benefits of CRB, like reduced tillage or equipment savings cost, and producers are less likely to perceive increased greenhouse gas (GHG) emissions as a negative externality associated with CRB. A multi-stakeholder approach can provide more depth and breadth to understanding complex decisions about farm management practices, and these results have implications for policies that incentivize adopting best farm management practices
Natural Variation in Yeast Reveals Multiple Paths for Acquiring Higher Stress Resistance
Get PDFBackground
Organisms frequently experience environmental stresses that occur in predictable patterns and combinations. For wild Saccharomyces cerevisiae yeast growing in natural environments, cells may experience high osmotic stress when they first enter broken fruit, followed by high ethanol levels during fermentation, and then finally high levels of oxidative stress resulting from respiration of ethanol. Yeast have adapted to these patterns by evolving sophisticated “cross protection” mechanisms, where mild ‘primary’ doses of one stress can enhance tolerance to severe doses of a different ‘secondary’ stress. For example, in many yeast strains, mild osmotic or mild ethanol stresses cross protect against severe oxidative stress, which likely reflects an anticipatory response important for high fitness in nature. Results
During the course of genetic mapping studies aimed at understanding the mechanisms underlying natural variation in ethanol-induced cross protection against H2O2, we found that a key H2O2 scavenging enzyme, cytosolic catalase T (Ctt1p), was absolutely essential for cross protection in a wild oak strain. This suggested the absence of other compensatory mechanisms for acquiring H2O2 resistance in that strain background under those conditions. In this study, we found surprising heterogeneity across diverse yeast strains in whether CTT1 function was fully necessary for acquired H2O2 resistance. Some strains exhibited partial dispensability of CTT1 when ethanol and/or salt were used as mild stressors, suggesting that compensatory peroxidases may play a role in acquired stress resistance in certain genetic backgrounds. We leveraged global transcriptional responses to ethanol and salt stresses in strains with different levels of CTT1 dispensability, allowing us to identify possible regulators of these alternative peroxidases and acquired stress resistance in general. Conclusions
Ultimately, this study highlights how superficially similar traits can have different underlying molecular foundations and provides a framework for understanding the diversity and regulation of stress defense mechanisms
Polyphenol-Induced Protein Structural Modifications in Sorghum on Pasting Properties
Get PDFBlack sorghum contains a high amount of anthocyanins and proanthocyanidins, whereas white sorghum predominantly comprises phenolic acids. Polyphenols covalently and non-covalently interact with protein, whereas the structure of both compounds affects these interactions. This study investigated the interactions between phenolic acids, anthocyanins, proanthocyanidins and prolamin, which is the major protein fraction in sorghum, and their effect on the pasting properties of white and black, whole and milled sorghum using different chemical agents. Urea increased the pasting viscosity of black sorghum, but not that of white sorghum, indicating that hydrogen bonds and hydrophobic interactions between prolamin and anthocyanins and proanthocyanidins play an important role in the viscosity development of black sorghum. The addition of sodium chloride (NaCl) and guanidium hydrochloride (GdnHCl) enhanced the peak viscosity of all samples. Proanthocyanidins increased the molecular size, diminished the α-helical structure, and altered the tertiary structure of prolamin, which may have decreased the breakdown viscosity of black sorghum in the presence of dithiothreitol (DTT) and in both acidic and alkaline environments. Polyphenol-protein interactions in black sorghum may, therefore, be used to develop clean-label ingredients to improve paste stability in starch-based products
Evaluating Injury Risk Caused by Potential Drift of Florpyrauxifen-Benzyl or Quinclorac in Corn
Get PDFOf relevance to the off-target movement of herbicides in Arkansas is the drift of rice herbicides in the state’s agricultural landscape, where aerial application of herbicides is common, raising the prima facie question of the risk of damage to other sensitive crops. The aim of this study was to evaluate the response of corn to postemergence applications of florpyrauxifen-benzyl or quinclorac, which were applied directly to the crop at low rates (0.78 or 1.56 to 12.5% of the normal use rate for labeled crops). This was investigated through three site-year field experiments conducted in Fayetteville (2020 and 2021) and Tillar (2020), Arkansas. Injury and yield response varied among site-years. No corn injury was visible at the Tillar site. At the Fayetteville site in 2020, florpyrauxifen-benzyl rates caused an average injury of 5% and 6% 2 and 4 wk after application (WAA), respectively. The 12.5% rate in 2021 caused a greater injury (7% injury) compared to other lower rates 2 WAA and such a response departed from linearity to stochasticity 4 WAA. Compared to the nontreated control, the 6.25% rate caused nearly 20% yield reduction at the Fayetteville site in 2020, and the 12.5% rate caused a 10% yield reduction at the Tillar site. The quinclorac rate of 12.5% at the Fayetteville site in 2020 caused an average of 7% injury-2 WAA and \u3c5% injury when averaged across the other rates, or 4 WAA. The injury was more differentiated in 2021, particularly with the 12.5% rate (\u3e20% injury) from the average injury of 5% with the other lower rates 2 WAA; the injury remained similar or slightly recovered 4 WAA. Compared to the nontreated control, quinclorac rates caused an average yield reduction of \u3c5% at the Fayetteville site in 2020, whereas the 12.5% rate caused nearly 20% and 10% yield reductions at the Fayetteville site in 2021 and at the Tillar site, respectively
The Changing Importance of Competence Generationally: Developing Trust, Online and Offline
Get PDFGeneralized trust has reached new lows in America, with young Americans now trusting the least. This complicates the process of interacting with new people, which formerly contributed to trust. The present study thus tested whether networked modes of social contact and social learning might add to interpersonal competence and generalized trust. Responses to a national web survey were matched to US Census percentages for sex, race, ethnicity, age, and region. The sample resembles the US population demographically and is theoretically large enough to represent it (N = 1500). Data were analyzed using SPSS and PROCESS. Diverse contact in person was unrelated to trust in general and only contributed to trust for respondents 70 or older when particular age groups were considered. Interpersonal competence, on the other hand, contributed to trust overall, and for respondents 18–29, 40–49, and 50–59. Feeling capable of interacting with new people in person has become more important than the contact itself for trusting, as a way of generating numerous diverse interactions over time. Networked efforts of sociability and posting behavior were also related to trust here. Posting related to trust for respondents 18–29, while sociability contributed to trust for those 18–29, 30–39, and 50–59. Social presence (i.e., sensing immediacy and intimacy in networked settings) related to trust overall and for those 18–29 and 40–49. Computer-mediated communication (CMC) competence contributed to trust indirectly, by way of social presence, and the indirect effect was the largest for the youngest users surveyed. CMC competence had a larger association with interpersonal competence for younger generations as well, which became a second indirect path to trusting. Different age groups draw trust from different places, and trust interventions should also differ with age
Archaeology in the Fourth Dimension: Studying Landscapes with Multitemporal PlanetScope Satellite Data
Get PDFFor the last seven years, PlanetScope satellites have started near-daily imaging of parts of the Earth’s surface, making high-density multitemporal, multispectral, 3-m pixel imagery accessible to researchers. Multitemporal satellite data enables landscape archaeologists to examine changes in environmental conditions at time scales ranging from daily to decadal. This kind of temporal resolution can accentuate landscape features on the ground by de-emphasizing non-permanent signatures caused by seasonal or even daily changes in vegetation. We argue that the availability of high spatial and temporal resolution multispectral imagery from Planet Inc. will enable new approaches to studying archaeological visibility in landscapes. While palimpsests are discrete overlapping layers of material accumulation, multitemporal composites capture cyclical and seasonal time and can be used to interpret past landscape histories at multiple scales. To illustrate this perspective, we present three case studies using PlanetScope imagery in tropical environments on the Indian Ocean islands of Madagascar, Mauritius, and Zanzibar
Tulane Virus Persistence and Microbial Stability in 3D Food Ink under Various Storage Conditions: A Pre- and Post-Printing Analysis
Get PDF3D food printers facilitate novel customization of the physicochemical properties of food. This study aimed to investigate the impact of storage conditions on the inactivation of the human norovirus surrogate, Tulane virus (TuV), within 3D printed foods. TuV-inoculated protein cookie food ink (∽ 4 log PFU/g) was distributed into 18 3D food printer capsules (50 g each); half immediately underwent extrusion. Storage of the capsules and printed food products at 20 °C (0, 6, 12, and 24 h), 4 °C (0, 1, 3, and 5d), and − 18 °C (0, 1, 3, and 5d) was completed before analysis for TuV via plaque assays in addition to aerobic plate count, yeast and mold counts, and pH and water activity (aw) measurements. A significant 3-way interaction effect was observed between time, temperature, and storage method (capsule/print) (p = 0.006). Significant findings include: (1) A greater reduction in virions was observed in capsules after 24 h at 20 °C and (2) a substantial reduction in virions at 4 °C from day 0 to day 1 was observed, independent of storage method. Microbial indicators remained steady across temperatures, with storage temperature significantly impacting pH and aw. A significant two-way interaction effect (p = 0.006) was found between microorganism type (yeast/aerobic counts) and temperature. This research seeks to provide insights for the food industry and regulatory bodies in crafting guidelines for the safe storage and handling of 3D printed foods and inks
The Impact of Brain Cholesterol (24-hydroxycholesterol (24-HC) and 27- hydroxycholesterol (27-HC)) on Invitro Phenotypes of Brain Metastatic Breast Cancer Cells
Get PDFIntroduction: Brain metastases is one of the leading causes of breast cancer mortality and rates continue to increase. It has been previously shown that cholesterol metabolism is an important regulator of cancer progression. 24(S)-hydroxycholesterol (24-HC) and 27- hydroxycholesterol (27-HC) are cholesterol derivatives primarily found in the brain but their role in regulating oncoprotein expression remains unclear. The goal of this thesis was to determine the effect of 24-HC and 27-HC on in-vitro metastatic phenotypes of breast cancer cells previously shown by the Bailey laboratory to metastasize to the brain in a hematogenous metastasis xenograft model.
Materials and Methods: Western blot and fluorescence microscopy were used to assess the 24- HC and 27-HC dependent expression of the epidermal growth factor receptor (EGFR) and aurora kinase A (AURKA) in breast cancer cells which have the propensity to metastasize to the brain. EGFR and AURKA are two oncoproteins previously shown by the Bailey laboratory and others to be upregulated in breast cancer cells that metastasize to the brain (Simeon et al., 2021 and unpublished data). The anchorage independent growth assay, tubule formation assay and cell migration assay were used to assess the in-vitro phenotypes of brain metastatic breast cancer cells treated with 24-HC and 27-HC.
Results: Expression of EGFR and AURKA by hydroxycholesterols is suppressed in the highly brain metastatic cell line, MDA-MB-231 ANGPTL4-mGFP, but is induced in the MDA-MB-231 mGFP cell line. 24-HC and 27-HC suppressed anchorage independent growth and tubule formation in MDA-MB-231 ANGPTL4-mGFP cell line. However, the hydroxycholesterols promoted cellular migration in MDA-MB-231 ANGPTL4-mGFP cell line.
Conclusion: 24-HC and 27-HC are pleotropic modulators of the in vitro metastatic phenotypes of breast cancer cells
Real-time Measurements from Wearable Sensors to Enhance Stability on Uneven Terrain
Get PDFThe presented thesis is a study of sensation associated with inversion/eversion movement about the anterior/posterior axis. The long-term goal is to create a system that provides feedback to a prosthesis user, so their chances of falling is decreased. This feedback system would use wearable sensors to detect certain angles, so that sensory feedback could be provided. The study aimed to determine if Xsens Movella DOT sensors could be used in a system like this, so the accuracy of the Xsens Movella DOT sensors was assessed and the difference in angles that could be determined by them when compared to that of an unimpaired ankle was measured.
Sensor accuracy was verified using two other angle detection techniques, digital level measurement and right triangle trigonometry calculations. Plotting the sensors’ data relative to the trigonometry calculations resulted in almost a linear line of a slope near 1.
The just noticeable difference (JND) about 0° was calculated for three participants. The JND ranged from 1.2° to 2.1°, and the average JND was 1.64°, which is considerably more than any detected inaccuracies in the sensors. Consequently, further study of using wearable sensors to establish a feedback system to improve stability for lower limb prostheses users is warranted.
In the future, testing the JND about other degrees, other than 0°, will take place to determine if sensitivity is different at other ankle positions, and the protocol used in this study will be improved with more particpants and a better understanding of how to find and calculate the JND
Responsible Great Power or Threat? Chinese Involvement in 21st Century United Nations Peacekeeping Operations and Peacebuilding in Africa
Get PDFThis paper examines why China pursues its peacebuilding agenda and participation in United Nations Peacekeeping Operations in the African continent in the twenty-first century and evaluate whether China poses a threat or is a responsible great power in Africa in this context. Through the lenses of theories of international relations, historical analysis, and human rights, this study finds that China is unsuccessful in being a responsible great power and poses a threat to the stability and agency of African states with which it engages