cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25549/usctheses-c3-203024
title: Synthesis, characterization and application of metal and semiconductor nanowires

description: Nanostructured materials such as nanowires have attracted significant attention in the past two decades. Both metallic and semiconducting nanowires have been demonstrated as important building blocks for numerous electronic and optoelectronic device applications. In this thesis, we have demonstrated a scalable route for synthesizing vertically aligned semiconducting nanowires using nanosphere lithography (NSL) technique in combination with selected area metal organic chemical vapor deposition (SA-MOCVD). Comparable optical properties were observed between the nanowires produced by NSL patterning technique and nanowires produced by using more expensive and slow electron beam lithography. We have also used capacitance-voltage measurement technique to determine the doping level in these nanowire arrays. In metallic nanowires, we have demonstrated fabrication of high performance transparent conductive electrodes by using Ag nanowires and proposed a technique to synthesis thin Ag nanowires which can have applications in various optoelectronic devices. ❧ This dissertation describes the above-mentioned aspects in detail and accordingly consists of seven chapters. Following an overview and an introduction of fundamental knowledge of nanolithography and transparent conductive electrodes in Chapter 1, Chapter 2 discusses the scalable nanosphere lithography patterning and selected area growth of vertically aligned GaAs nanowire arrays, a route towards optimized optical absorption and reflection. ❧ Chapter 3 discusses the continued work on GaAs nanowire array and employs the use of capacitance-voltage measurement technique to determine the doping level of these nanowires which is important for using these nanowires for fabrication of any electronic devices. ❧ Chapter 4 deals with an important issue of replacement of traditional ITO as a transparent conductive electrode (TCE) for optoelectronic devices. There is a need for replacement of ITO due to several drawback associated with ITO as will be discussed in detail in the chapter. We demonstrate the viability of silver nanowire based random network film as a potential replacement. We achieve remarkable performance in terms of sheet resistance and transparency which rivals that of ITO, supporting a very strong case for Ag nanowire film. We combine traditional spray coating technique with novel Ag nanowires to fabricate high performance TCE. In chapter 5, we further improve the performance of the TCE produced by Ag nanowires by using a dry transfer technique demonstrating a performance comparable to ITO and much better than other potential candidates that can be used as TCE. ❧ In chapter 6 we addressed an important issue associated with using Ag nanowires as a future candidate for TCE by proposing a technique to synthesis thin Ag nanowires which can find application in optoelectronic device. ❧ Finally in chapter 7, we conclude by discussing the future directions and work that needs to be done in order to carry forward the advance made in this thesis.
DOI: 10.25549/usctheses-c3-205177
title: The impact of ritonavir on HIV therapy: balancing efficacy and toxicity

description: Objective: The aim of this dissertation is to evaluate the impact of ritonavir (RTV) on HIV therapy.  We examine both beneficial and harmful outcomes caused by combining RTV with nucleoside reverse transcriptase inhibitors (NRTIs). ❧ Methods: The research integrates both in vitro as well as in vivo studies to provide a comprehensive picture to the effect of RTV.  Quantification of drug concentrations was performed using an HPLC system coupled to a tandem mass spectrometer (LC-MS). Pharmacodynamics effects were evaluated using a variety of molecular biological techniques. ❧ A small pilot study evaluating five patients receiving stable treatment of Trizivir was intensified for 10 days with lopinavir (LPV) boosted with RTV.  We examined the change in plasma and intracellular drug concentrations caused by this combination. ❧ Two large population patient studies, ACTG 5142 and CCTG 578, were examined to determine the effect of the treatment combination of tenofovir disoproxal fumarate (TDF) and RTV.  We also identified SNPs in these patients using the MassARRAY iPLEX Gold and identified SNPs which may indicate a protection against or increased risk for kidney dysfunction. ❧ Results: Our in vitro data indicates that RTV can act as an inhibitor of the efflux transporter ABCC2, but that it has little effect on ABCC4 and ABCC5. ❧ We found that the addition of LPV/RTV led to a significant decrease in plasma NRTI levels for the Trizivir combination, but that intracellular drug levels did not change significantly. ❧ Using ACTG 5142 and CCTG 578, we illustrate a link between the combination of TDF and RTV with kidney dysfunction.  We have also identified several SNPs that are predictive for renal outcome, but the data is conflicting between the two studies. ❧ Conclusion: This study has found that RTV appears to change intracellular NRTI concentrations by inhibiting ABCC2.  In patients, this sequesters the drug in circulating CD4+ cells despite increased NRTI metabolism caused by RTV activation of glucuronidation pathways.  This finding suggests that a shift away from plasma AUC and instead focusing on intracellular drug concentrations should occur for therapies combined with RTV. ❧ Increased kidney dysfunction is another consequence of RTV inhibition of ABCC2, especially when RTV is combined with TFV.  Patients receiving this combination will need to be closely monitored to ensure their long-term safety. ❧ Additionally, we evaluated SNPs in these targeted transporters to identify predictive markers for susceptibility for kidney dysfunction.  We have identified 18 total SNPs in ABCC2 and ABCC4 that had a significant impact on kidney function.  However, the impact these SNPs had varied for 5 SNPs that were identified in both the ACTG 5142 and CCTG 578 studies.  More research into the impact on protein expression and function will need to be performed to identify SNPs that can be used to evaluate the long term prognosis for patients.
DOI: 10.25549/usctheses-c3-176798
title: Page 16
DOI: 10.25549/usctheses-c3-176810
title: Page 28
DOI: 10.25549/usctheses-c3-141476
title: Page 209
DOI: 10.25549/usctheses-c3-160544
title: Page 26
DOI: 10.25549/usctheses-c3-160599
title: Page 81
DOI: 10.25549/usctheses-c3-199734
title: Fidelity approach to topological quantum phase transitions

description: This dissertation puts forward the concept of fidelity as a way to understand and characterize quantum phase transitions involving topological phases. It lies at the interphase between Condensed Matter and Quantum Phase Transitions. ❧ We find that the fidelity metric, which characterizes the degree of distinghuishability between two quantum states, can serve as a useful tool in the understanding of transitions involving topological phases. ❧ The methodology does not require a complete knowledge of the physical mechanism involved in the occurrence of the critical point, such as the identification of a local order parameter and a symmetry breaking mechanism, the fundamental pillars of critical phenomena. Topological phases are unique in that they cannot be classified under these methodologies, due to their lack of local order parameters. It is one of the purposes of this thesis to understand how well we can characterize the phase boundaries between these phases using fidelity concepts. ❧ In the first part, we introduce two quantum models that exhibit a phase transition between an ordered and a topological phase, as quantified by the topological entanglement entropy. In the thermodynamic limit, the different components of the fidelity metric exhibit a divergence, signalling the occurrence of the critical point. ❧ In the second part, we introduce models that have phase boundaries between two distinct topological phases, and we show that the fidelity is successful at identifying the occurrence of a critical region. Moreover, a finite size scaling analysis is carried out, from which we determine the value of critical exponents.
DOI: 10.25549/usctheses-c3-207282
title: A moment's thought: W.B. Yeats and Immanuel Kant

description: This dissertation attempts to demonstrate that William Butler Yeats was an important intellectual as well as a canonical Modernist poet.  I argue that Yeats’s philosophical research influenced the development of ideas in his poetry and prose.  Most notably, he was indebted to idealist tendencies in the works of George Berkeley and Immanuel Kant.  Specifically, his study of Kant led Yeats to envision logical continuity between various occult sources, William Blake’s ‘contraries,’ and Kant’s ‘antinomies,’ which he believed were essential to the creation of poetic art.  Thus, I attempt to show that Yeats was much indebted to Kant, especially The Critique of Pure Reason.  This indebtedness was often demonstrated by his deliberate opposition to empiricism and various forms of materialism.  My argument challenges the “Silly Willy” moniker that has been frequently attributed to him, and I show that his commitment to philosophical ideas in his poetry and prose made him not so silly after all.
DOI: 10.25549/usctheses-c3-217215
title: Physical activity and risk of B-cell non-Hodgkin's lymphoma among Los Angeles women

description: Study Aim: There have been few studies focusing on the association between physical activity and risk of B-cell non-Hodgkin’s lymphomas (NHL) and their results are inconsistent. This study is designed to assess this association among women in Los Angeles County. Methods: An individually matched population-based case-control design was applied in this study. 990 case participants and their 1:1 matched controls were recruited in total. Exposure information was collected through in-person interviews finished by all the cases as well as the controls. Multivariate conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), which measure the relationship between physical activity and risk of B-cell NHL. Results: Physical activity does not protect against developing B-cell NHL among women in Los Angeles County. The same results were found for the association between physical activity and B-cell NHL risk by race/ethnicity, age at diagnosis, body mass index (BMI) and B-cell NHL subtype. Compared to the inactive women, those who were at the highest physical activity level had 30% lower B-cell NHL risk (OR=0.70, 95% CI=0.52-0.94). However, no dose response was observed with increasing physical activity level (p value for the trend test=0.92). Conclusion: Physical activity was not associated with B-cell NHL risk. Future studies with larger sample sizes were needed to confirm our results.
DOI: 10.25549/usctheses-c3-160546
title: Page 28
DOI: 10.25549/usctheses-c3-160603
title: Page 85
DOI: 10.25549/usctheses-c3-176819
title: Page 37
DOI: 10.25549/usctheses-c3-176820
title: Page 38
DOI: 10.25549/usctheses-c3-177092
title: Page 97
DOI: 10.25549/usctheses-c3-177104
title: Page 109
DOI: 10.25549/usctheses-c3-170662
title: Page 152
DOI: 10.25549/usctheses-c3-170671
title: Page 161
DOI: 10.25549/usctheses-c3-177116
title: Page 121
DOI: 10.25549/usctheses-c3-208147
title: The impact of an empowerment education intervention on efficacy, community involvement, and physiological health outcomes for overweight and obese minority youth

description: Obesity continues to rise in the United States. Childhood and adolescent obesity rates have increased rapidly, particularly for Latino and African American youth. Two groups of minority adolescents, eight in the first year, and thirteen in the second year, attended a one-week empowerment education intervention that aimed to educate about factors linked to maintaining a healthy lifestyle. Moreover, for four months following the education intervention, the participants implemented a community action plan to address a particular public health gap or need within their communities. Participants were encouraged to maintain process journals and were surveyed pre and post intervention in order to gather data pertaining to empowerment and self-efficacy levels. Parental satisfaction with the intervention was also measured. Data was measured qualitatively revealing four main themes in the process journals. In addition, quantitative data was also measured and tested for significance. This study has implications for a culturally relevant, early intervention model to addressing the rising epidemic among adolescents.
DOI: 10.25549/usctheses-c3-160587
title: Page 69
DOI: 10.25549/usctheses-c3-170669
title: Page 159
DOI: 10.25549/usctheses-c3-177095
title: Page 100
DOI: 10.25549/usctheses-c3-177107
title: Page 112
DOI: 10.25549/usctheses-c3-196091
title: Genetic comparison of Aggregatibacter aphrophilus

description: Aggregatibacter aphrophilus is oral commensal, a closely related Aggregatibacter actinomycetemcomitans is considered one of the most important periodontal pathogens. The high degree of genetic and phenotypic similarity between these two species offers an opportunity to examine the fundamental differences in virulence attributes between these species. We proposed a hypothesis that the variation in the virulence potentials of A. aphrophilus and A. actinomycetemcomitans can be attributed to the acquisition of specific virulence determinants by the latter species. Two aims were formulated to test the hypothesis. In Aim 1, the loci of 5 virulence determinants in A. actinomycetemcmitans were compared to the comparable loci in the genome of A. aphrophilus to identify possible insertion/deletion relationship of the genes for the determinants. In Aim 2, a catalase gene specific to A. actinomycetemcomitans was transferred to A. aphrophilus and tested for its protective function again bactericidal effects of hydrogen peroxide. Among the 5 virulence determinants of A. actinomycetemcomitans, two (aae and emaA) were present in both species and demonstrated the same gene orders in the loci and their neighboring regions. Three of the virulence determinants (cdtABC, ltxCABD and kat) were absent in A. aphrophilus. Two of the determinants (ltxCABD and kat) demonstrated insertion/deletion relationship of based on the analysis of the neighboring regions of the determinants. The possibility that cdtABC was acquired by A. actinomycetemcomitans as a large genomic island was also suggested but not clearly demonstrated. The kat of A. actinomycetemcomitans strain D7S-1 was transferred and integrated into the comparable locus in the genome of A. aphrophilus strain NJ8700.  The wild type NJ8700 and kat-deleted mutants of D7S-1 showed sensitivity to treatment with hydrogen peroxide; while cells expressing kat including A. aphrophilus kat-expressing mutant, wild type D7S-1 and rescued D7S-1 kat-deleted mutant had substantial survival rate ranging from 15-25% after H₂O₂ treatment. In conclusion, these two closely related species demonstrated an insertion/deletion relationship in 3 of the 5 loci of virulence determinants of A. actinomycetemcomitans. The catalase gene from A. actinomycetemcomitans can be transferred into the comparable locus in A. aphrophilus and demonstrate a similar function in both species. The results support the hypothesis that differential acquisition of genes for virulence determinants could occur during the evolution of the two species.
DOI: 10.25549/usctheses-c3-198269
title: Urban superintendents and their selection of successful elementary school principals

description: Urban superintendents are hired and commissioned to raise student achievement, especially for students who have been traditionally underserved by underperforming public schools. Site principals have a significant impact on student achievement; therefore, successful superintendents must be able to recruit, select, and hire effective principals in order to raise student achievement. This study examined how effective urban superintendents recruit, select, and hire successful elementary principals. ❧ Three primary research questions were used in this mixed methods study. Two instruments were used to collect data. The quantitative data was collected from online surveys from 29 urban superintendents, and qualitative data was collected from three personal interviews with successful superintendents. The data was triangulated and analyzed to help answer the research questions of this study. ❧ The research study resulted in several key findings. Superintendents look for particular background characteristics in principal candidates such as elementary teaching experience, prior administrative experience, and advanced degrees from respected universities. In addition, superintendents hire candidates who have excellent people skills and who are superb instructional leaders. School districts that offer competitive salaries and have a reputation of success are able to recruit top quality principal candidates. Finally, school districts that carefully paper screen applications, thoroughly check employment references, and conduct a comprehensive interview process are able to identify and hire the best possible principal candidate from the candidate pool.
DOI: 10.25549/usctheses-c3-206771
title: Superintendent communication strategies and experiences that promote trust and positive relationships with the school board during the entry period:  a case study

description: Superintendents have vast demands placed upon them by their school boards and via the political pipeline. The purpose of the study was to identify strategies/behaviors that successful superintendents used to build strong relationships and trust with their school boards within their entry period. It is during the entry period that determines whether a superintendent experiences success or failure. This study captured those strategies in order to provide a blueprint by which other superintendents, researchers, policy makers, and leadership training programs could use. ❧ This study implored the use of a qualitative approach using surveys and face-to-face interviews with superintendents across California. Nine doctoral students from the USC Rossier School of Education developed survey questions and corroborated and validated them through the conceptual frameworks of Bolman and Deal (2008), Watkins (2003), Covey (2006), and Hurley (2006). The research team sent out a total of 90 surveys to superintendents and their school board president/board member designee (as identified through the selection criteria). A total of 64 superintendents and 48 board members participated in this study with 46 matched paired surveys (superintendent and board member) returned for further case study consideration. From the aforementioned surveys, the researchers chose one superintendent and board member, respectively, to interview. These interviews provided the contextual basis by which qualitative data was obtained and triangulated to confirm the survey results. ❧ The results of this study shed light on the following questions: (1) What strategies/behaviors were successful superintendents using to build strong relationships and trust with the board during their entry period; (2) How did superintendents implement these strategies and evaluate their success; and (3) What formal/informal leadership preparation assisted superintendents for entry into the superintendency? ❧ From the survey results, the following themes emerged that successful superintendents experienced during their entry period to establish trust and a positive relationship with their school boards: 1) the use of a formal or informal superintendent entry plan during the first 90-100 days had positive benefits for new or transitioning superintendents; 2) the frequency of the communication strategies played a key role in the establishment of trust; and 3) informal administrative experiences prepared future leaders for the superintendency.
DOI: 10.25549/usctheses-c3-195260
title: Efficient data collection in wireless sensor networks: modeling and algorithms

description: This dissertation focuses on data gathering for wireless sensor networks. Data gathering deals with the problem of transmitting measurements of physical phenomena from the sensor nodes to one or more sinks in the most efficient manner. It is usually the main task performed by a sensor network and therefore the main cause of energy depletion for the nodes. The research efforts presented here propose insightful models for the phenomena sampled by sensor networks with the purpose of designing more energy efficient data gathering schemes. ❧ We first focus on phenomena that can be characterized by a diffusive process. We propose to model the data via discretized diffusion partial differential equations (PDEs). The rationale is that few equation coefficient plus initial and contour conditions may have the potential to completely describe such spatio-temporal phenomena in a compact manner. We propose and study an algorithm for the in-network identification of the diffusion coefficients.  Then, we adopt a spatially non stationary correlation model and we study how this impacts correlation based data gathering and, in particular, the problem of optimally placing a sink node in a sensor network region.  Finally, we view each round of sensor measurements as a still image and we represent it via intensity histograms. This way, we can adopt image content analysis tools (intensity histograms matching) to analyze the data and determine which rounds of measurements are of interest to the final users. Therefore energy can be saved by transmitting only some rounds of measurements to the base station.  We study the above models and the performance of data collection algorithms via analysis and experiments on synthetic and real data.
DOI: 10.25549/usctheses-c3-206629
title: Prescribed commercially-prepared Language Arts intervention curriculum:  Illuminating a practitioner perspective

description: This study investigates the perceptions of a small group of Language Arts intervention teachers who have been prescribed a commercially-prepared intervention curriculum for use with their students. Written surveys and semi-structured interviews were used to gather data in pursuit of answers to the following research questions: (1) How do teachers perceive the purpose and features of a prescribed commercially-prepared Language Arts intervention curriculum? (2) How do teachers perceive their implementation of a prescribed commercially-prepared Language Arts intervention curriculum? (3) How do teachers perceive the professional development experiences designed to guide their implementation of a prescribed commercially-prepared Language Arts intervention curriculum? ❧ Participants’ responses to closed and open-ended prompts both confirm and add nuances to concepts found in literature on curriculum and curriculum implementation. The teachers describe the prescribed commercially-prepared Language Arts intervention curriculum as both a safety net for new teachers and as a tool to be used in the pursuit of learning objectives. ❧ The participants perceive the role of the classroom teacher as curriculum completer. They have a perceived partnership with the curriculum authors in which the authors provide a research-based curriculum designed for a broad audience of students and the teachers make adaptations that make the curriculum best fit the local context of their specific students. This perceived partnership is mitigated by district policies regarding curriculum implementation and the district-provided professional development experiences designed to support implementation of the curriculum.