Matching Items (188)
Description
The green fluorescent protein (GFP)-like fluorescent proteins play an important role for the color of reef-building corals. Different colors of extant coral fluorescent proteins (FPs) have evolved from a green ancestral protein. Interestingly, green-to-red photoconversion FPs (Kaede-type Red FPs) are only found in clade D from Scleractinia (Faviina suborder). Therefore, I focus on the evolution of Kaede-type FPs from Faviina suborder ancestral FP. A total of 13 mutations have been identified previously that recapitulate the evolution of Kaede-type red FPs from the ancestral green FP. To examine the effect of each mutation, total ten reconstructed FPs were analyzed and six x-ray crystal structures were solved. These substitutions created a more hydrophilic environment around the carbonyl group of Phe61. Also, they increased the flexibility of the c-terminal chain, which keeps it from interacting with the entrance of the putative solvent channel. The photoconversion reaction shows a twophase kinetics. After the rapid initial phase, the overall reaction followed the firstorder kinetics. Based on the crystal structure analysis, I propose a new mechanism for Kaede-type FP photoconversion process, which a proton transfers via Gln38 to the carbonyl group of Phe61.
ContributorsKim, Hanseong (Author) / Wachter, Rebekka M. (Thesis advisor) / Fromme, Petra (Committee member) / Redding, Kevin E (Committee member) / Arizona State University (Publisher)
Created2012
Description
The heliobacterial reaction center (HbRC) is widely considered the simplest and most primitive photosynthetic reaction center (RC) still in existence. Despite the simplicity of the HbRC, many aspects of the electron transfer mechanism remain unknown or under debate. Improving our understanding of the structure and function of the HbRC is important in determining its role in the evolution of photosynthetic RCs. In this work, the function and properties of the iron-sulfur cluster FX and quinones of the HbRC were investigated, as these are the characteristic terminal electron acceptors used by Type-I and Type-II RCs, respectively. In Chapter 3, I develop a system to directly detect quinone double reduction activity using reverse-phase high pressure liquid chromatography (RP-HPLC), showing that Photosystem I (PSI) can reduce PQ to PQH2. In Chapter 4, I use RP-HPLC to characterize the HbRC, showing a surprisingly small antenna size and confirming the presence of menaquinone (MQ) in the isolated HbRC. The terminal electron acceptor FX was characterized spectroscopically and electrochemically in Chapter 5. I used three new systems to reduce FX in the HbRC, using EPR to confirm a S=3/2 ground-state for the reduced cluster. The midpoint potential of FX determined through thin film voltammetry was -372 mV, showing the cluster is much less reducing than previously expected. In Chapter 7, I show light-driven reduction of menaquinone in heliobacterial membrane samples using only mild chemical reductants. Finally, I discuss the evolutionary implications of these findings in Chapter 7.
ContributorsCowgill, John (Author) / Redding, Kevin (Thesis advisor) / Jones, Anne (Committee member) / Fromme, Petra (Committee member) / Arizona State University (Publisher)
Created2012
Description
This dissertation considers how adolescent identity is constructed and represented in commercial musical theatre for youth (e.g. Broadway and Disney Theatrical Group) by examining two commercial productions with adolescents in lead roles--Spring Awakening and Disney's High School Musical. My theoretical framework is intersectionality which creates a foundation for my research within the field of childhood studies, gender studies, and performance studies to illuminate current US American trends in youth oriented art and research. My framework extends into a case study methodology exploring the world of childhood and youth sexuality through a close read of the popular Broadway musical adaptation, Spring Awakening. In addition, a second investigation chronicles the world of Disney's High School Musical through my own intersectional tool, the Disney Industrial Complex. I claim that adolescence, as a constructed identity, exists as a multi-faceted intersectional category composed of multiple and conflicting intersections such as gender, race, sex, ethnicity, and so on. These intersections develop over the course of the period known as "adolescence" and "youth." The goal of this dissertation is to serve as a reference for other theatre educators and their work with young people creating art.
ContributorsBliznik, Sean J (Author) / Etheridge-Woodson, Stephani (Thesis advisor) / Saldana, Johnny (Committee member) / Adelman, Madelaine (Committee member) / Arizona State University (Publisher)
Created2012
Description
Lyme disease is a common tick-borne illness caused by the Gram-negative bacterium Borrelia burgdorferi. An outer membrane protein of Borrelia burgdorferi, P66, has been suggested as a possible target for Lyme disease treatments. However, a lack of structural information available for P66 has hindered attempts to design medications to target the protein. Therefore, this study attempted to find methods for expressing and purifying P66 in quantities that can be used for structural studies. It was found that by using the PelB signal sequence, His-tagged P66 could be directed to the outer membrane of Escherichia coli, as confirmed by an anti-His Western blot. Further attempts to optimize P66 expression in the outer membrane were made, pending verification via Western blotting. The ability to direct P66 to the outer membrane using the PelB signal sequence is a promising first step in determining the overall structure of P66, but further work is needed before P66 is ready for large-scale purification for structural studies.
ContributorsRamirez, Christopher Nicholas (Author) / Fromme, Petra (Thesis director) / Hansen, Debra (Committee member) / Department of Physics (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Calcium hydroxide carbonation processes were studied to investigate the potential for abiotic soil improvement. Different mixtures of common soil constituents such as sand, clay, and granite were mixed with a calcium hydroxide slurry and carbonated at approximately 860 psi. While the carbonation was successful and calcite formation was strong on sample exteriors, a 4 mm passivating boundary layer effect was observed, impeding the carbonation process at the center. XRD analysis was used to characterize the extent of carbonation, indicating extremely poor carbonation and therefore CO2 penetration inside the visible boundary. The depth of the passivating layer was found to be independent of both time and choice of aggregate. Less than adequate strength was developed in carbonated trials due to formation of small, weakly-connected crystals, shown with SEM analysis. Additional research, especially in situ analysis with thermogravimetric analysis would be useful to determine the causation of poor carbonation performance. This technology has great potential to substitute for certain Portland cement applications if these issues can be addressed.
ContributorsHermens, Stephen Edward (Author) / Bearat, Hamdallah (Thesis director) / Dai, Lenore (Committee member) / Mobasher, Barzin (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
This project and research intended to address how to successfully run and teach a high school level Theatre I course. The research portion of the project focused on activities to use in the classroom, how to run a drama club and put on productions, and how to create a positive classroom environment where students feel comfortable creating art. The creation portion of the project focused on the things a teacher will need in the classroom: an introduction letter, vision statement, syllabus, and unit plans. The final product includes three unit plans: Introduction to Theatre I, Introduction to Acting, and Theatre and Social Change. The use of the materials in this thesis can help first-time Theatre teachers to become better prepared to run their classroom.
ContributorsKircher, Alyssa Elaine (Author) / Sterling, Pamela (Thesis director) / Whissen, Elaine (Committee member) / Saldana, Johnny (Committee member) / Barrett, The Honors College (Contributor) / School of Film, Dance and Theatre (Contributor) / Division of Teacher Preparation (Contributor)
Created2014-05
Description
Abstract As we move forward in education reform in the globalized 21st century, the United States must visit new ways to teach science in high school classrooms. The goal of this investigation is to analyze the current research literature for the best and most promising teaching strategies and techniques in secondary education biology classrooms that promote academic excellence for all students. Looking at policy and school reform literature in science education to establish the context of the current system, the paper will not focus on the political as or systematic changes needed to ground an overall successful system. However, because of their inherent effect on the education system, the political aspects of education reform will be briefly addressed. The primary focus, by addressing the emphasis on standardization, inflexibility of instruction and lack of creativity specifically in high school biology classrooms, seeks to clarify small changes that can influence students' academic outcomes. The United States is performing on such a poor level in science and math proficiency that it cannot match students abroad and this is seen through test scores and the production of competent graduates. This investigation serves to organize literature from education researchers and showcase best and promising teaching and learning practices that catalyze academic excellence for all students in our pluralistic, democratic and complex schooling and societal contexts.
ContributorsHildebrandt, Kevin Andrew (Author) / Ovando, Carlos (Thesis director) / Schugurensky, Daniel, 1958- (Committee member) / Fischman, Gustavo (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor)
Created2013-05
Description
As green buildings become more popular, the challenge of structural engineer is to move beyond simply green to develop sustainable, and high-performing buildings that are more than just environmentally friendly. For decades, Portland cement-based products have been known as the most commonly used construction materials in the world, and as a result, cement production is a significant source of global carbon dioxide (CO2) emissions, and environmental impacts at all stages of the process. In recent years, the increasing cost of energy and resource supplies, and concerns related to greenhouse gas emissions and environmental impacts have ignited more interests in utilizing waste and by-product materials as the primary ingredient to replace ordinary Portland cement in concrete systems. The environmental benefits of cement replacement are enormous, including the diversion of non-recycled waste from landfills for useful applications, the reduction in non-renewable energy consumption for cement production, and the corresponding emission of greenhouse gases. In the vast available body of literature, concretes consisting activated fly ash or slag as the binder have been shown to have high compressive strengths, and resistance to fire and chemical attack. This research focuses to utilize fly ash, by-product of coal fired power plant along with different alkaline solutions to form a final product with comparable properties to or superior than those of ordinary Portland cement concrete. Fly ash mortars using different concentration of sodium hydroxide and waterglass were dry and moist cured at different temperatures prior subjecting to uniaxial compressive loading condition. Since moist curing continuously supplies water for the hydration process of activated fly ash mortars while preventing thermal shrinkage and cracking, the samples were more durable and demonstrated a noticeably higher compressive strength. The influence of the concentration of the activating agent (4, or 8 M sodium hydroxide solution), and activator-to-binder ratio of 0.40 on the compressive strengths of concretes containing Class F fly ash as the sole binder is analyzed. Furthermore, liquid sodium silicate (waterglass) with silica modulus of 1.0 and 2.0 along with activator-to-binder ratio of 0.04 and 0.07 was also studied to understand its performance in contributing to the strength development of the activated fly ash concrete. Statistical analysis of the compressive strength results show that the available alkali concentration has a larger influence on the compressive strengths of activated concretes made using fly ash than the influence of curing parameters (elevated temperatures, condition, and duration).
ContributorsBanh, Kingsten Chi (Author) / Neithalath, Narayanan (Thesis director) / Rajan, Subramaniam (Committee member) / Mobasher, Barzin (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2013-05
Description
Membrane proteins located within or as attachments to the cell membrane play critical roles in many essential cellular functions and host-pathogen interactions. Knowledge of the structure and function of membrane proteins in pathogenic species can allow for the development of specific vaccines and therapeutic agents against the pathogen. Francisella tularensis is an intracellular pathogen that is the causative agent of the severe, life-threatening infection, tularemia, in humans and other small mammals. F. tularensis is prevalent within the environment and is a potential bioterrorism agent due to its high virulence and its ability to be spread easily as an aerosol. The CapBCA membrane protein complex has been identified as a virulence factor of F. tularensis. This project, derived from the Membrane Proteins in Infections Diseases (MPID) Project, aims to successfully express the membrane proteins CapBCA, which are crucial to the pathogenic properties of F. tularensis. To accomplish this goal, methods for in vivo recombinant expression and purification of membrane proteins are in the process of being developed. The expression of the CapA component has been successful for some time, therefore, the goal of this study is to develop an approach toward recombinant in vivo membrane protein expression of both the CapB and CapC components of the CapBCA membrane protein complex. In this study, the CapB and CapC components were expressed for the first time in vivo through the use of the novel MPID vector, pelB-MBP. The expression of the CapB and CapC components will allow for large-scale expressions to commence with the end goal of determining the crystal structures of the individual proteins or the complex. Ultimately, it is hoped that knowledge of these molecular structures can lead to the development of a vaccine or other therapeutic agents against this pathogen.
ContributorsTrimble, Kelli Lauren (Author) / Fromme, Petra (Thesis director) / Hansen, Debra (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Film, Dance and Theatre (Contributor)
Created2015-05
Description
This study examined the quality of professional life at a Title I school that has achieved the Arizona Department of Education's highest accountability rating of Excelling for eight consecutive years. By examining the factors that influence the school environment including teachers' attitudes and the connections within the teacher community at this school, a description emerged of the factors that influenced the quality of professional lives of teachers. This descriptive study sought to describe, "What is the quality of professional life for teachers at a Title I elementary school with a history of high levels of student achievement?" The research was conducted at Seneca Elementary school (a pseudonym) in the Seneca School District (a pseudonym). By examining the quality of professional life for teachers in a highly ranked Title I school, a better understanding of the quality of professional life may lead to recommendations for other schools with high levels of poverty on how to support teachers who work in high poverty schools. Within a theoretical framework of motivation-hygiene theory and socio cultural theory, the study identified principal leadership as a primary supporting factor of quality of professional life. The study also identified lack of input and lack of teacher control over curriculum and instruction as barriers to quality of professional life. Teachers described principal leadership, environment, social factors and teacher identity as contributors to enhancing the quality of professional life. Trust and focus emerged as additional factors that improved the workplace for teachers.
ContributorsThomas, Jeffrey J (Author) / Danzig, Arnold (Thesis advisor) / Fischman, Gustavo (Committee member) / Boyle, Charlotte (Committee member) / Arizona State University (Publisher)
Created2011