Matching Items (5)
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Description
Rubisco activase (Rca) from higher plants is a stromal ATPase essential for reactivating Rubiscos rendered catalytically inactive by endogenous inhibitors. Rca’s functional state is thought to consist of ring-like hexameric assemblies, similar to other members of the AAA+ protein superfamily. However, unlike other members, it does not form obligate hexamers

Rubisco activase (Rca) from higher plants is a stromal ATPase essential for reactivating Rubiscos rendered catalytically inactive by endogenous inhibitors. Rca’s functional state is thought to consist of ring-like hexameric assemblies, similar to other members of the AAA+ protein superfamily. However, unlike other members, it does not form obligate hexamers and is quite polydisperse in solution, making elucidation of its self-association pathway challenging. This polydispersity also makes interpretation of traditional biochemical approaches difficult, prompting use of a fluorescence-based technique (Fluorescence Correlation Spectroscopy) to investigate the relationship between quaternary structure and function. Like cotton β Rca, tobacco β Rca appears to assemble in a step-wise and nucleotide-dependent manner. Incubation in varying nucleotides appears to alter the equilibrium between varying oligomers, either promoting or minimizing the formation of larger oligomers. High concentrations of ADP seem to favor continuous assembly towards larger oligomers, while assembly in the presence of ATP-yS (an ATP analog) appears to halt continuous assembly in favor of hexameric species. In contrast, assembly in the “Active ATP Turnover” condition (a mixture of ATP and ADP) appears to favor an almost equal distribution of tetramer and hexamer, which when compared with ATPase activity, shows great alignment with maximum activity in the low µM range. Despite this alignment, the decrease in ATPase activity does not follow any particular oligomer, but rather decreases with increasing aggregation, suggesting that assembly dynamics may regulate ATPase activity, rather than the formation/disappearance of one specific oligomer. Work presented here also indicates that all oligomers larger than hexamers are catalytically inactive, thus providing support for the idea that they may serve as a storage mechanism to minimize wasteful hydrolysis. These findings are also supported by assembly work carried out on an Assembly Mutant (R294V), known for favoring formation of closed-ring hexamers. Similar assembly studies were carried out on spinach Rca, however, due to its aggregation propensity, FCS results were more difficult to interpret. Based on these findings, one could argue that assembly dynamics are essential for Rca function, both in ATPase and in regulation of Rubisco carboxylation activity, thus providing a rational for Rca’s high degree of polydispersity.
ContributorsSerban, Andrew J (Author) / Wachter, Rebekka M. (Thesis advisor) / Levitus, Marcia (Thesis advisor) / Redding, Kevin E (Committee member) / Van Horn, Wade D (Committee member) / Arizona State University (Publisher)
Created2018
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Description
Diabetes is prevalent among the Latino population in the United States. Engagement in healthy dietary behaviors, especially as a young adult, is an effective means of reducing risk for diabetes. Previous psychological theories have demonstrated that health beliefs and perceived barriers influence engagement in such behaviors. This research investigated beliefs

Diabetes is prevalent among the Latino population in the United States. Engagement in healthy dietary behaviors, especially as a young adult, is an effective means of reducing risk for diabetes. Previous psychological theories have demonstrated that health beliefs and perceived barriers influence engagement in such behaviors. This research investigated beliefs regarding risk for diabetes among the young, educated Latino population. Study 1 of this research sought to compare health beliefs and perceived barriers to barrier change in the young, educated Latino and European American populations. Latinos reported to have a higher perceived vulnerability to diabetes, but shared the belief in diet as the most important determinant of diabetes risk with European Americans. However, Latinos saw their diet as less malleable in their lives than did European Americans. Study 2 sought to replicate these findings and verify the existence of these beliefs. Young, educated Latinos' beliefs in the importance of diet yet a perceived lack of dietary changeability were confirmed. Furthermore, Study 2 evaluated the efficacy of health messages based in the principle of social proof in motivating health behavior change. Social proof, or social validation, describes the phenomenon in which people who see others similar to them engaging in a particular behavior are more likely to engage in that behavior. Latinos who were randomly assigned to receive a health message utilizing the principle of social proof to motivate healthy dietary changes were more likely to express a willingness to change their diet than those who did not receive such a message. These findings can inform the development of health campaigns seeking to promote healthy behaviors among young, educated Latinos.
ContributorsTowers, Michelle (Author) / Kwan, Virginia S. Y. (Thesis director) / Aiken, Leona S. (Committee member) / Williams, Deborah L. (Committee member) / Basilio, Camille D. (Committee member) / Barrett, The Honors College (Contributor)
Created2014-05
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Description

Due to the COVID-19 pandemic, declared in March of 2020, there have been many lifestyle changes which have likely influenced tobacco smoking behavior. Such lifestyle changes include lockdowns, stay at home orders, reduction in social cues related to smoking, increased stress, and boredom among other things. This study utilized a

Due to the COVID-19 pandemic, declared in March of 2020, there have been many lifestyle changes which have likely influenced tobacco smoking behavior. Such lifestyle changes include lockdowns, stay at home orders, reduction in social cues related to smoking, increased stress, and boredom among other things. This study utilized a cross-sectional survey which looked into these behaviors, primarily perceived risk to COVID-19, and determined if there is an association between perceived risk and education level/race. Education level is a proxy for income and material resources, therefore making it more likely that people with lower levels of education have fewer resources and higher perceived risk to negative effects of COVID-19. Additionally, people of color are often marginalized in the medical community along with being the target of heavy advertising by tobacco companies which have likely impacted risk to COVID-19 as well.

ContributorsLodha, Pratishtha (Author) / Leischow, J. Scott (Thesis director) / Pearson, Jennifer (Committee member) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

In 2003, Carmina Gisbert and her research team produced a tobacco plant that could remove lead from soil. To do so, they inserted a gene from wheat plants that produces phytochelatin synthase into a shrub tobacco plant (Nicotiana glauca) to increase N. glauca's absorption and tolerance of toxic metals, particularly

In 2003, Carmina Gisbert and her research team produced a tobacco plant that could remove lead from soil. To do so, they inserted a gene from wheat plants that produces phytochelatin synthase into a shrub tobacco plant (Nicotiana glauca) to increase N. glauca's absorption and tolerance of toxic metals, particularly lead and cadmium. Gisbert and her team aimed to genetically modify a plant so that it could be used for phytoremediation- using plants to remove toxic substances from the soil. Scientists have identified phytoremediation as an effective and efficient process to improve human health and reproductive health in contaminated areas. Metals like mercury and lead can cause birth defects during human development like cognitive impairment, cerebral palsy, deafness, tremors, and blindness.

Created2014-12-30
Description

In this paper, I analyze the reluctance of expanding nuclear power in the United States. This is done by exploring the history of nuclear power and using two conceptual theories to guide this analysis. The impact of nuclear accidents throughout history allows individuals to perceive risks as greater than they

In this paper, I analyze the reluctance of expanding nuclear power in the United States. This is done by exploring the history of nuclear power and using two conceptual theories to guide this analysis. The impact of nuclear accidents throughout history allows individuals to perceive risks as greater than they are while potentially ignoring the benefits of this energy method. By looking at the perception of risk through the Psychometric Theory of Risk, one can understand hesitance at a more individual level for perceived risk, knowledge, and trust. From there, one can look at more of a macro level with the Social Amplification of Risk Framework (SARF) to see what the psychometric paradigm may forget and view the ripple effects of media coverage and their effects on the perception of nuclear energy.

ContributorsEthridge, Ava (Author) / Reilly, Thom (Thesis director) / Eaton, John (Committee member) / Barrett, The Honors College (Contributor) / Dean, W.P. Carey School of Business (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Department of Management and Entrepreneurship (Contributor)
Created2022-12