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Description
More than 30% of college entrants are placed in remedial mathematics (RM). Given that an explicit relationship exists between students' high school mathematics and college success in science, technology, engineering, and mathematical (STEM) fields, it is important to understand RM students' characteristics in high school. Using the Education Longitudinal Survey 2002/2006 data, this study evaluated more than 130 variables for statistical and practical significance. The variables included standard demographic data, prior achievement and transcript data, family and teacher perceptions, school characteristics, and student attitudinal variables, all of which are identified as influential in mathematical success. These variables were analyzed using logistic regression models to estimate the likelihood that a student would be placed into RM. As might be expected, student test scores, highest mathematics course taken, and high school grade point average were the strongest predictors of success in college mathematics courses. Attitude variables had a marginal effect on the most advantaged students, but their effect cannot be evaluated for disadvantaged students, due to a non-random pattern of missing data. Further research should concentrate on obtaining answers to the attitudinal questions and investigating their influence and interaction with academic indicators.
ContributorsBarber, Rebecca (Author) / Garcia, David R. (Thesis advisor) / Powers, Jeanne (Committee member) / Rodrigue Mcintyre, Lisa (Committee member) / Arizona State University (Publisher)
Created2011
Description
There is a documented gap between research-based recommendations produced by university-based scholars in the field of education in the United States and the evidence that U.S. politicians' use when deciding which educational policies to implement or amend. This is a problem because university-based education scholars produce vast quantities of research each year, some of which could, and more importantly should, be useful to politicians in their decision-making processes and yet, politicians continue to make policy decisions about education without the benefit of much of the knowledge that has been gained through scholarly research. I refer to the small fraction of university-based education scholars who are demonstrably successful at getting scholarly research into the hands of politicians to be used for decision-making purposes as "university-based bipartisan scholarship brokers". They are distinct from other university-based education scholars in that they engage with politicians from both political parties around research and, as such, are able to use scholarly research to influence the education policymaking process. The problem that this dissertation addresses is the lack of use, by U.S. politicians, of scholarly research produced by United States university-based education scholars as input in education policy decisions. The way in which this problem is explored is through studying university-based bipartisan scholarship brokers. I focused on three areas for exploration: the methods university-based bipartisan scholarship brokers use to successfully get U.S. politicians to consider scholarly research as an input in their decision-making processes around education policy, how these scholars are different than the majority of university-based education policy scholars, and how they conceive of the education policy-setting agenda. What I uncovered in this dissertation is that university-based bipartisan scholarship brokers are a complete sub-group of university-based education scholars. They work above the rigorous promotion and tenure requirements of their home universities in order to use scholarly research to help serve the research needs of politicians. Their engagement is distinct among university-based education scholars and through this dissertation their perspective is presented in participants' own authentic language.
ContributorsAckman, Emily Rydel (Author) / Garcia, David R. (Thesis advisor) / Powers, Jeanne (Committee member) / Fischman, Gustavo E (Committee member) / Arizona State University (Publisher)
Created2013
Description
The purpose of this study was to determine Maricopa County high school teachers' perspectives on educational policy rhetoric messages. The current time and setting among Arizona high school educators provide a unique opportunity to gain the perspective of those who will be implementing the reform and held accountable for subsequent student performance before the reform takes effect and while the policy talk that precedes reform efforts is at its peak. The questions that this study sought to answer were the following: 1. What are Maricopa County High School teachers' perceptions of policy talk regarding Common Core Standards Initiative (CCSSI) and high stakes accountability measures with respect to student achievement outcomes and implementation? 2. How do these perspectives vary by teacher context (e.g. experience, content taught, district, and site demographics) within the 9-12 educational system? To determine the answers, a sequential explanatory mixed methods design was selected. The first phase involved the collection and analysis of quantitative data followed by collection and analysis of qualitative data in the second phase. A survey instrument was developed utilizing CCSSI/PARCC policy rhetoric statements and was administered to high school teachers. Initially, survey data identified overall trends among high school teachers' perceptions of educational reform policy (CCSSI) talk messages. Subsequently, qualitative focus group interviews further informed results. Results indicated that portions of policy talk messages have resonated; however, these tended to be the oldest and most oft-repeated statements. Newer messages related to changes in instructional practices and student outcomes were less widely accepted. It would appear from the results that teachers are unsure of what CCSSI really entails due to a lack of clarity in message and presentations for practitioners regarding implementation. A significant complicating factor in this effort is the unique nature of the CCSSI as a nationalized movement. Furthermore in Arizona, the backlash of conservative Republicans against CCSSI has led some teachers to believe that the implementation is up in the air, without discernible direction or support. This has left educators to interpret this latest change through their own lenses, which has defined their level of agreement and acceptance with these policy statements.
ContributorsWattawa, Teresa (Author) / Garcia, David R. (Thesis advisor) / Merrill, Bruce (Committee member) / Deprez, Suzie (Committee member) / Arizona State University (Publisher)
Created2014
Description
This dissertation is based on an empirical study that focused on student reenrollment, an essential but largely overlooked element of school choice policies. Based on the school choice literature, I extended the hypothesis of parental charter school choice to the subject of reenrollment. In doing so, I referred jointly to theories from the fields of public choice and business, in order to better understand student reenrollment in a maturing education market. By tracking student enrollment records over multiples years and linking them to school attributes (socio-economic status, racial/ethnic composition of the student body, school quality label), student demographics, and student academic performance, I established a complex student reenrollment database. I applied a rigorous statistical model to this data, allowing me to identify a number of important insights about student reenrollment in a maturing education market. I described the reenrollment patterns at the state level, as well as a predictive model of reenrollment outcome at the individual level. My analyses indicate that student reenrollment was the most common school choice outcome: most students reenrolled in their present schools, regardless of that school's quality label; however, the student reenrollment rates in charter schools were lower than those in traditional public schools. I observed patterns of segregation in student reenrollment within Arizona, as reenrollment appeared to be significantly polarized with respect to school attributes and students' characteristics. There were two distinct patterns that appeared to coexist in Arizona's student reenrollment data: quality-oriented reenrollment and similarity-oriented reenrollment. The findings of this study extend the school choice literature to include student reenrollment. This study challenges the application of market metaphors in the context of school choice, which generally advocate the reform of public schools through encouraging students to switch, promoting school competition and thereby improving public education quality. Instead of using command and control policies to shame schools into improvement, however, policymakers and parents should employ school accountability policies and the practice of school labeling as a trigger to reinvest in struggling schools, rather than encouraging students to find a new one.
ContributorsDong, Haiying (Author) / Garcia, David R. (Thesis advisor) / Powers, Jeanne (Thesis advisor) / Barnett, Joshua (Committee member) / Arizona State University (Publisher)
Created2012
Description
The dopamine 2 receptor (D2R) is a Class A GPCR which is essential for signaling in the nervous system, and has been implicated in numerous illnesses. While there are over 50 currently approved drugs which act on D2R, the structure has never been determined in detail. Although crystallography has historically been difficult with GPCRs, in recent years many structures have been solved using lipidic cubic phase (LCP) crystallization techniques. Sample preparation for LCP crystallization typically requires optimization of genetic constructs, recombinant expression, and purification techniques in order to produce a sample with sufficient stability and homogeneity. This study compares several genetic constructs utilizing different promoters, fusion proteins, fusion positions, and truncations in order to determine a high quality construct for LCP crystallization of
D2R. All constructs were expressed using the Bac-to-bac baculovirus expression system, then extracted with n-Dodecyl-β-D-Maltoside (DDM) and purified using metal affinity chromatography. Samples were then tested for quantity, purity, and homogeneity using SDS-PAGE, western blot, and size-exclusion chromatography. High quality samples were chosen based on insect cell expression levels, purification yield, and stability estimated by the levels of homomeric protein relative to aggregated protein. A final construct was chosen with which to continue future studies in optimization of thermal stability and crystallization conditions. Future work on this project is required to produce a sample amenable to crystallization. Screening of ligands for co-crystallization,
thermostabilizing point mutations, and potentially optimization of extraction and purification techniques prior to crystallization trials. Solving the D2R structure will lead to an increased understanding of its signaling mechanism and the mechanisms of currently approved drugs, while also providing a basis for more effective structure-based drug design.
D2R. All constructs were expressed using the Bac-to-bac baculovirus expression system, then extracted with n-Dodecyl-β-D-Maltoside (DDM) and purified using metal affinity chromatography. Samples were then tested for quantity, purity, and homogeneity using SDS-PAGE, western blot, and size-exclusion chromatography. High quality samples were chosen based on insect cell expression levels, purification yield, and stability estimated by the levels of homomeric protein relative to aggregated protein. A final construct was chosen with which to continue future studies in optimization of thermal stability and crystallization conditions. Future work on this project is required to produce a sample amenable to crystallization. Screening of ligands for co-crystallization,
thermostabilizing point mutations, and potentially optimization of extraction and purification techniques prior to crystallization trials. Solving the D2R structure will lead to an increased understanding of its signaling mechanism and the mechanisms of currently approved drugs, while also providing a basis for more effective structure-based drug design.
ContributorsErler, Maya Marie (Author) / Liu, Wei (Thesis director) / He, Ximin (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
G protein-coupled receptors, or GPCRs, are receptors located within the membrane of cells that elicit a wide array of cellular responses through their interactions with G proteins. Recent advances in the use of lipid cubic phase (LCP) for the crystallization of GPCRs, as well as increased knowledge of techniques to improve receptor stability, have led to a large increase in the number of available GPCR structures, despite historic difficulties. This project is focused on the histamine family of receptors, which are Class A GPCRs that are involved in the body’s allergic and inflammatory responses. In particular, the goal of this project was to design, express, and purify histamine receptors with the ultimate goal of crystallization. Successive rounds of optimization included the use of recombinant DNA techniques in E.coli to truncate sections of the proteins and the insertion of several fusion partner proteins to improve receptor expression and stability. All constructs were expressed in a Bac-to-Bac baculovirus expression system using Sf9 insect cells, solubilized using n-Dodecyl-β-D-Maltoside (DDM), and purified using immobilized metal affinity chromatography. Constructs were then analyzed by SDS-Page, Western blot, and size-exclusion chromatography to determine their presence, purity, and homogeneity. Along with their expression data from insect cells, the most stable and homogeneous construct from each round was used to design successive optimizations. After 3 rounds of construct design for each receptor, much work remains to produce a stable sample that has the potential to crystallize. Future work includes further optimization of the insertion site of the fusion proteins, ligand screening for co-crystallization, optimization of purification conditions, and screening of potential thermostabilizing point mutations. Success in solving a structure will allow for a more detailed understanding of the receptor function in addition to its vital use in rational drug discovery.
ContributorsCosgrove, Steven Andrew (Author) / Liu, Wei (Thesis director) / Mills, Jeremy (Committee member) / Mazor, Yuval (Committee member) / W. P. Carey School of Business (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
This work comprises a cumulative effort to provide analysis of proteins relevant to understanding and treating human disease. This dissertation focuses on two main protein complexes: the structure of the Chimp adenovirus Y25 capsid assembly, as used in the SARS-CoV-2 vaccine, Vaxzveria, and the Dbl family RhoGEF (guanosine exchange factor) Syx and its associated small G protein, RhoA. The course of research was influenced heavily by the onset of the Covid-19 pandemic and associated lockdown, which pushed anyone with the means to do meaningful research to shift priorities towards addressing the greatest public health crisis since the 1918 flu pandemic.
Analysis of the Syx-RhoA complex for the purposes of structurally guided drug design was initially the focus of heavy optimization efforts to overcome the numerous challenges associated with expression, purification, and handling of this protein. By analyzing E. Coli derived protein new important knowledge was gained about this protein’s biophysical characteristics which contribute to its behavior and may inform drug design efforts. Expression in SF9 insect cells resulted in promising conditions for production of homogeneous and monodispersed protein. Homology modeling and molecular dynamics simulation of this protein support hypotheses about its interactions with both RhoA as well as regions of the cytoplasmic leaflet of the cell membrane.
Structural characterization of ChAdOx1, the adenoviral vector used in the AstraZeneca Covid-19 vaccine, Vaxzveria resulted in the highest resolution adenovirus structure ever solved (3.07Å). Subsequent biochemical analysis and computational simulations of PF4 with the ChAdOx1 capsid reveal interactions with important implications for vaccine induced thrombocytic throbocytopenia syndrome, a disorder observed in approximately 0.000024% of patients who receive Vaxzveria.
ContributorsBoyd, Ryan J (Author) / Fromme, Petra (Thesis advisor) / Chiu, Po-Lin (Committee member) / Liu, Wei (Committee member) / Arizona State University (Publisher)
Created2021
Description
Structural-based drug discovery is becoming the essential tool for drug development withlower cost and higher efficiency compared to the conventional method. Knowledge of the
three-dimensional structure of protein targets has the potential to accelerate the process
for screening drug candidates. X-ray crystallography has proven to be the most used and
indispensable technology in structural-based drug discovery. The provided
comprehensive structural information about the interaction between the disease-related
protein target and ligand can guide the chemical modification on the ligand to improve
potency and selectivity. X-ray crystallography has been upgraded from traditional
synchrotron to the third generation, which enabled the surge of the structural
determination of macromolecular. The introduction of X-ray free electron laser further
alleviated the uncertain and time-consuming crystal size optimization process and
extenuated the radiation damage by “diffraction before destruction”. EV-D68 2A
protease was proved to be an important pharmaceutical target for acute flaccid myelitis.
This thesis reports the first atomic structure of the EV-D68 2A protease and the structuresof its two mutants, revealing it adopting N-terminal four-stranded sheets and C-terminal
six-stranded ß-barrels structure, with a tightly bound zinc atom. These structures will
guide the chemical modification on its inhibitor, Telaprevir. Integrin ⍺Mβ2 is an integrin
with the α I-domain, related to many immunological functions including cell
extravasation, phagocytosis, and immune synapse formation, so studying the molecular
ligand-binding mechanism and activation mechanism of ⍺Mβ2 is of importance. This
thesis uncovers the preliminary crystallization condition of ⍺Mβ2-I domain in complex
with its ligand Pleiotrophin and the initial structural model. The structural model shows consistency with the previous hypothesis that the primary binding sites are metal iondependent
adhesion sites on ⍺Mβ2-I domain and the thrombospondin type-1 repeat (TSR)
domains of Pleiotrophin. Drug molecules with high potency and selectivity can be
designed based on the reported structures of the EV-D68 2A protease and ⍺Mβ2-I domain
in the future.
ContributorsLiu, Chang (Author) / Liu, Wei (Thesis advisor) / Stephanopoulos, Nicholas (Committee member) / Chiu, Po-Lin (Committee member) / Arizona State University (Publisher)
Created2021
Description
Cryogenic Electron Microscopy (Cryo-EM) is a method that can be used for studying the structure of biological systems. Biological samples are frozen to cryogenic temperatures and embedded in a vitreous ice when they are imaged by electrons. Due to its ability to preserve biological specimens in near-native conditions, cryo-EM has a significant contribution to the field of structural biology.Single-particle cryo-EM technique was utilized to investigate the dynamical characteristics of various protein complexes such as the Nogo receptor complex, polymerase ζ (Polζ) in yeast and human integrin ⍺vβ8-pro-TGFβ1-GARP complex. Furthermore, I proposed a new method that can potentially improve the sample preparation for cryo-EM. The Nogo receptor complex was expressed using baculovirus expression system in sf9 insect cells and isolated for structural studies. Nogo receptor complex was found to have various stoichiometries and interactions between individual proteins. A structural investigation of the yeast apo polymerase ζ holoenzyme was also carried out. The apo Polζ displays a concerted motions associated with expansion of the Polζ DNA-binding channel upon DNA binding. Furthermore, a lysine residue that obstructs the DNA-binding channel in apo Polζ was found and suggested a gating mechanism. In addition, cryo-EM studies of the human integrin ⍺vβ8-pro-TGFβ1-GARP complex was conducted to assess its dynamic interactions. The 2D classifications showed the ⍺vβ8-pro-TGFβ1-GARP complex is highly flexible and required several sample preparation techniques such as crosslinking and graphene oxide coating to improve protein homogeneity on the EM grid. To overcome challenges within the cryo-EM technique such as particle adsorption on air-water interface, I have documented a collaborative work on the development and application of lipid monolayer sandwich on cryo-EM grid. Cryogenic electron tomography (cryo-ET) along with cryo-EM were used to study the characteristics of lipid monolayer sandwich as a potential protective layer for EM grid. The cryo-ET results demonstrated that the thickness of lipid monolayer is adequate for single-particle cryo-EM processing. Furthermore, there was no appearance of preferred orientations in cryo-EM and cryo-ET images. To establish that this method is actually beneficial, more data must be collected, and high-resolution structures of protein samples must be obtained using this methodology.
ContributorsTruong, Chloe Du (Author) / Chiu, Po-Lin (Thesis advisor) / Liu, Wei (Committee member) / Mazor, Yuval (Committee member) / Arizona State University (Publisher)
Created2021
Description
Every year, potential graduate students hunt through websites and promotional materials searching for the perfect program to fit their needs. The search requires time and patience, especially for those future scholars who seek a doctoral program in Education Policy Studies (EPS) with a focus on interacting with the policymaking process. The primary objective of this project was to explore the promotional materials of EPS doctoral programs in order to better understand how these programs promote formalized training for students to engage with education policy and the policymaking process. I selected the top 10 EPS programs in the nation along with my own institution (Arizona State University) as the sample for this study. By reviewing their websites, I found that programs provide a comparable training description for similar careers as well as upholding similar goals in the subfield of EPS. Ultimately, the program materials revealed that while these programs advertise significant formalized training in research methods and scholarly pursuits, opportunities to actively engage with policymaking were missing from the materials. Instead, it is more likely that such opportunities occur in informal settings such as apprenticeships and working at research centers. This study provides a detailed discussion of how programs promote training opportunities to students, the types of careers that programs claim to prepare students for, and the important role that faculty projects and additional resources play in the student experience related to engagement with policy and the policymaking process.
ContributorsLong-Genovese, Stacey (Author) / Garcia, David R. (Thesis advisor) / Ott, Molly (Committee member) / Hinchey, Patricia (Committee member) / Arizona State University (Publisher)
Created2014