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This dissertation examines a planned missing data design in the context of mediational analysis. The study considered a scenario in which the high cost of an expensive mediator limited sample size, but in which less expensive mediators could be gathered on a larger sample size. Simulated multivariate normal data were generated from a latent variable mediation model with three observed indicator variables, M1, M2, and M3. Planned missingness was implemented on M1 under the missing completely at random mechanism. Five analysis methods were employed: latent variable mediation model with all three mediators as indicators of a latent construct (Method 1), auxiliary variable model with M1 as the mediator and M2 and M3 as auxiliary variables (Method 2), auxiliary variable model with M1 as the mediator and M2 as a single auxiliary variable (Method 3), maximum likelihood estimation including all available data but incorporating only mediator M1 (Method 4), and listwise deletion (Method 5).
The main outcome of interest was empirical power to detect the mediated effect. The main effects of mediation effect size, sample size, and missing data rate performed as expected with power increasing for increasing mediation effect sizes, increasing sample sizes, and decreasing missing data rates. Consistent with expectations, power was the greatest for analysis methods that included all three mediators, and power decreased with analysis methods that included less information. Across all design cells relative to the complete data condition, Method 1 with 20% missingness on M1 produced only 2.06% loss in power for the mediated effect; with 50% missingness, 6.02% loss; and 80% missingess, only 11.86% loss. Method 2 exhibited 20.72% power loss at 80% missingness, even though the total amount of data utilized was the same as Method 1. Methods 3 – 5 exhibited greater power loss. Compared to an average power loss of 11.55% across all levels of missingness for Method 1, average power losses for Methods 3, 4, and 5 were 23.87%, 29.35%, and 32.40%, respectively. In conclusion, planned missingness in a multiple mediator design may permit higher quality characterization of the mediator construct at feasible cost.
The main outcome of interest was empirical power to detect the mediated effect. The main effects of mediation effect size, sample size, and missing data rate performed as expected with power increasing for increasing mediation effect sizes, increasing sample sizes, and decreasing missing data rates. Consistent with expectations, power was the greatest for analysis methods that included all three mediators, and power decreased with analysis methods that included less information. Across all design cells relative to the complete data condition, Method 1 with 20% missingness on M1 produced only 2.06% loss in power for the mediated effect; with 50% missingness, 6.02% loss; and 80% missingess, only 11.86% loss. Method 2 exhibited 20.72% power loss at 80% missingness, even though the total amount of data utilized was the same as Method 1. Methods 3 – 5 exhibited greater power loss. Compared to an average power loss of 11.55% across all levels of missingness for Method 1, average power losses for Methods 3, 4, and 5 were 23.87%, 29.35%, and 32.40%, respectively. In conclusion, planned missingness in a multiple mediator design may permit higher quality characterization of the mediator construct at feasible cost.
ContributorsBaraldi, Amanda N (Author) / Enders, Craig K. (Thesis advisor) / Mackinnon, David P (Thesis advisor) / Aiken, Leona S. (Committee member) / Tein, Jenn-Yun (Committee member) / Arizona State University (Publisher)
Created2015
Description
The holy grail of computer hardware across all market segments has been to sustain performance improvement at the same pace as silicon technology scales. As the technology scales and the size of transistors shrinks, the power consumption and energy usage per transistor decrease. On the other hand, the transistor density increases significantly by technology scaling. Due to technology factors, the reduction in power consumption per transistor is not sufficient to offset the increase in power consumption per unit area. Therefore, to improve performance, increasing energy-efficiency must be addressed at all design levels from circuit level to application and algorithm levels.
At architectural level, one promising approach is to populate the system with hardware accelerators each optimized for a specific task. One drawback of hardware accelerators is that they are not programmable. Therefore, their utilization can be low as they perform one specific function. Using software programmable accelerators is an alternative approach to achieve high energy-efficiency and programmability. Due to intrinsic characteristics of software accelerators, they can exploit both instruction level parallelism and data level parallelism.
Coarse-Grained Reconfigurable Architecture (CGRA) is a software programmable accelerator consists of a number of word-level functional units. Motivated by promising characteristics of software programmable accelerators, the potentials of CGRAs in future computing platforms is studied and an end-to-end CGRA research framework is developed. This framework consists of three different aspects: CGRA architectural design, integration in a computing system, and CGRA compiler. First, the design and implementation of a CGRA and its instruction set is presented. This design is then modeled in a cycle accurate system simulator. The simulation platform enables us to investigate several problems associated with a CGRA when it is deployed as an accelerator in a computing system. Next, the problem of mapping a compute intensive region of a program to CGRAs is formulated. From this formulation, several efficient algorithms are developed which effectively utilize CGRA scarce resources very well to minimize the running time of input applications. Finally, these mapping algorithms are integrated in a compiler framework to construct a compiler for CGRA
At architectural level, one promising approach is to populate the system with hardware accelerators each optimized for a specific task. One drawback of hardware accelerators is that they are not programmable. Therefore, their utilization can be low as they perform one specific function. Using software programmable accelerators is an alternative approach to achieve high energy-efficiency and programmability. Due to intrinsic characteristics of software accelerators, they can exploit both instruction level parallelism and data level parallelism.
Coarse-Grained Reconfigurable Architecture (CGRA) is a software programmable accelerator consists of a number of word-level functional units. Motivated by promising characteristics of software programmable accelerators, the potentials of CGRAs in future computing platforms is studied and an end-to-end CGRA research framework is developed. This framework consists of three different aspects: CGRA architectural design, integration in a computing system, and CGRA compiler. First, the design and implementation of a CGRA and its instruction set is presented. This design is then modeled in a cycle accurate system simulator. The simulation platform enables us to investigate several problems associated with a CGRA when it is deployed as an accelerator in a computing system. Next, the problem of mapping a compute intensive region of a program to CGRAs is formulated. From this formulation, several efficient algorithms are developed which effectively utilize CGRA scarce resources very well to minimize the running time of input applications. Finally, these mapping algorithms are integrated in a compiler framework to construct a compiler for CGRA
ContributorsHamzeh, Mahdi (Author) / Vrudhula, Sarma (Thesis advisor) / Gopalakrishnan, Kailash (Committee member) / Shrivastava, Aviral (Committee member) / Wu, Carole-Jean (Committee member) / Arizona State University (Publisher)
Created2015
Description
Massive glycerol cluster ions with many charges (~ 106 Da, ~ ±100 charges) have been generated by electrospray to bombard biomolecules and biological sample surfaces. The low impact energy per nucleon facilitates intact sputtering and ionization of biomolecules which can be subsequently imaged. Various lipids, peptides and proteins have been studied. The primary cluster ion source has been coupled with an ion-microscope imaging mass spectrometer (TRIFT-1, Physical Electronics). A lateral resolution of ~3µm has been demonstrated, which is acceptable for sub-cellular imaging of animal cells (e.g. single cancer cell imaging in early diagnosis). Since the available amount of target molecules per pixel is limited in biological samples, the measurement of useful ion yields (ratio of detected molecular ion counts to the sample molecules sputtered) is important to determine whether enough ion counts per pixel can be obtained. The useful ion yields of several lipids and peptides are in the 1-3×10-5 range. A 3×3 µm2lipid bilayer can produce ~260 counts/pixel for a meaningful 3×3 µm2 pixel ion image. This method can probably be used in cell imaging in the future, when there is a change in the lipid contents of the cell membrane (e.g. cancer cells vs. normal cells).
ContributorsZhang, Jitao (Author) / Williams, Peter (Thesis advisor) / Hayes, Mark (Committee member) / Nelson, Randall (Committee member) / Arizona State University (Publisher)
Created2015
Description
Breast cancer is the most common cancer and currently the second leading cause of death among women in the United States. Patients’ five-year relative survival rate decreases from 99% to 25% when breast cancer is diagnosed late. Immune checkpoint blockage has shown to be a promising therapy to improve patients’ outcome in many other cancers. However, due to the lack of early diagnosis, the treatment is normally given in the later stages. An early diagnosis system for breast cancer could potentially revolutionize current treatment strategies, improve patients’ outcomes and even eradicate the disease. The current breast cancer diagnostic methods cannot meet this demand. A simple, effective, noninvasive and inexpensive early diagnostic technology is needed. Immunosignature technology leverages the power of the immune system to find cancer early. Antibodies targeting tumor antigens in the blood are probed on a high-throughput random peptide array and generate a specific binding pattern called the immunosignature.
In this dissertation, I propose a scenario for using immunosignature technology to detect breast cancer early and to implement an early treatment strategy by using the PD-L1 immune checkpoint inhibitor. I develop a methodology to describe the early diagnosis and treatment of breast cancer in a FVB/N neuN breast cancer mouse model. By comparing FVB/N neuN transgenic mice and age-matched wild type controls, I have found and validated specific immunosignatures at multiple time points before tumors are palpable. Immunosignatures change along with tumor development. Using a late-stage immunosignature to predict early samples, or vice versa, cannot achieve high prediction performance. By using the immunosignature of early breast cancer, I show that at the time of diagnosis, early treatment with the checkpoint blockade, anti-PD-L1, inhibits tumor growth in FVB/N neuN transgenic mouse model. The mRNA analysis of the PD-L1 level in mice mammary glands suggests that it is more effective to have treatment early.
Novel discoveries are changing understanding of breast cancer and improving strategies in clinical treatment. Researchers and healthcare professionals are actively working in the early diagnosis and early treatment fields. This dissertation provides a step along the road for better diagnosis and treatment of breast cancer.
In this dissertation, I propose a scenario for using immunosignature technology to detect breast cancer early and to implement an early treatment strategy by using the PD-L1 immune checkpoint inhibitor. I develop a methodology to describe the early diagnosis and treatment of breast cancer in a FVB/N neuN breast cancer mouse model. By comparing FVB/N neuN transgenic mice and age-matched wild type controls, I have found and validated specific immunosignatures at multiple time points before tumors are palpable. Immunosignatures change along with tumor development. Using a late-stage immunosignature to predict early samples, or vice versa, cannot achieve high prediction performance. By using the immunosignature of early breast cancer, I show that at the time of diagnosis, early treatment with the checkpoint blockade, anti-PD-L1, inhibits tumor growth in FVB/N neuN transgenic mouse model. The mRNA analysis of the PD-L1 level in mice mammary glands suggests that it is more effective to have treatment early.
Novel discoveries are changing understanding of breast cancer and improving strategies in clinical treatment. Researchers and healthcare professionals are actively working in the early diagnosis and early treatment fields. This dissertation provides a step along the road for better diagnosis and treatment of breast cancer.
ContributorsDuan, Hu (Author) / Johnston, Stephen Albert (Thesis advisor) / Hartwell, Leland Harrison (Committee member) / Dinu, Valentin (Committee member) / Chang, Yung (Committee member) / Arizona State University (Publisher)
Created2015
Description
This dissertation examines lexical and phonetic variations between Daigi, Hakka, and Modern Standard Chinese elements as used in two Daoist temples of southern Taiwan, the Daode Yuan (DDY) and Yimin Miao (YMM) in Kaohsiung, Taiwan, which form linguistic repertoires from which religious communities construct language variants called religiolects. Specific variations in the use of these repertoires appear to be linked to specific religious thought processes. Among my results, one finds that phonetic features of Daigi and Hakka appear linked to the use of language in religious contexts at the DDY and YMM, especially such that alterations in pronunciation, which would otherwise be inappropriate, are linked to speakers of the religiolects processing and producing religious thought in ways they otherwise would not. For example, what would normally be pronounced [tʰe laɪ] internal to one's body would be archaicized as [tʰe lue], from frequent contact with [lue tan] inner alchemy; this leads to reinforced conception of the inner body as sacred space. One also finds that semantic features of lexical items received sacralized contours in overt and non-overt ways, such that lexical items that would otherwise be irreligious become religious in nature; e.g., instances of the appearance of 道, especially in binomial items, would be resolved or parsed by reference to the sacred meaning of the word (such as the [to] in [tsui to tsui], which normally means having its source in, coming to be associated with 道 as path from sacred font).
ContributorsJackson, Paul Allen (Author) / Bokenkamp, Stephen (Thesis advisor) / Oh, Youngkyun (Committee member) / Chen, Huaiyu (Committee member) / Swanson, Todd (Committee member) / Arizona State University (Publisher)
Created2015
Description
Rapid advancements in genomic technologies have increased our understanding of rare human disease. Generation of multiple types of biological data including genetic variation from genome or exome, expression from transcriptome, methylation patterns from epigenome, protein complexity from proteome and metabolite information from metabolome is feasible. "Omics" tools provide comprehensive view into biological mechanisms that impact disease trait and risk. In spite of available data types and ability to collect them simultaneously from patients, researchers still rely on their independent analysis. Combining information from multiple biological data can reduce missing information, increase confidence in single data findings, and provide a more complete view of genotype-phenotype correlations. Although rare disease genetics has been greatly improved by exome sequencing, a substantial portion of clinical patients remain undiagnosed. Multiple frameworks for integrative analysis of genomic and transcriptomic data are presented with focus on identifying functional genetic variations in patients with undiagnosed, rare childhood conditions. Direct quantitation of X inactivation ratio was developed from genomic and transcriptomic data using allele specific expression and segregation analysis to determine magnitude and inheritance mode of X inactivation. This approach was applied in two families revealing non-random X inactivation in female patients. Expression based analysis of X inactivation showed high correlation with standard clinical assay. These findings improved understanding of molecular mechanisms underlying X-linked disorders. In addition multivariate outlier analysis of gene and exon level data from RNA-seq using Mahalanobis distance, and its integration of distance scores with genomic data found genotype-phenotype correlations in variant prioritization process in 25 families. Mahalanobis distance scores revealed variants with large transcriptional impact in patients. In this dataset, frameshift variants were more likely result in outlier expression signatures than other types of functional variants. Integration of outlier estimates with genetic variants corroborated previously identified, presumed causal variants and highlighted new candidate in previously un-diagnosed case. Integrative genomic approaches in easily attainable tissue will facilitate the search for biomarkers that impact disease trait, uncover pharmacogenomics targets, provide novel insight into molecular underpinnings of un-characterized conditions, and help improve analytical approaches that use large datasets.
ContributorsSzelinger, Szabolcs (Author) / Craig, David W. (Thesis advisor) / Kusumi, Kenro (Thesis advisor) / Narayan, Vinodh (Committee member) / Rosenberg, Michael S. (Committee member) / Huentelman, Matthew J (Committee member) / Arizona State University (Publisher)
Created2015
Description
There are many educational issues connected to the exponential growth of the Latina/o population in the U.S. One such issue is Latina/os’ educational outcomes in the area of literacy. Despite the increased attention to subpopulations of students (e.g., English language learners, students with disabilities) there is little attention given to students that do not fit neatly into one subcategory, which positions Latina/o language minorities (LMs) with learning disabilities (LDs) in a liminal space where their educational services are fragmented into either being a student with LD or a LM student. Unfortunately, labels that are meant to afford students resources often result in fragmenting students’ educational experiences. This becomes evident when attempting to locate research on students who have ethnic, linguistic, and ability differences. Rarely are their educational needs as Latina/o LMs with LD met fluidly. Understanding the intersections of ethnicity, language, and ability differences in situated literacy practice is imperative to creating the deep, nuanced understanding of how Latina/o LMs with LD might become proficient in the use of critical twenty-first century tools such as new literacies. In this study I used cultural historical activity theory in combination with New Literacy Studies (Cope & Kalantzis, 2009; Gee, 1996) and intersectionality (McCall, 2014) to examine how Latina/o LMs with LD’s participated in literacies across in- and out-of-school contexts with the following research questions: In what ways does participation in literacy change for Latina/o LMs with LD as they move between in- and out-of-school? What situated identities do LMs with LD enact and resist while participating in literacy across in- and out-of-school contexts?
ContributorsGonzalez, Taucia (Author) / Artiles, Alfredo J. (Thesis advisor) / Kozleski, Elizabeth B. (Committee member) / Hudelson, Sarah (Committee member) / Arizona State University (Publisher)
Created2015
Description
This study investigated the ability to relate a test taker’s non-verbal cues during online assessments to probable cheating incidents. Specifically, this study focused on the role of time delay, head pose and affective state for detection of cheating incidences in a lab-based online testing session. The analysis of a test taker’s non-verbal cues indicated that time delay, the variation of a student’s head pose relative to the computer screen and confusion had significantly statistical relation to cheating behaviors. Additionally, time delay, head pose relative to the computer screen, confusion, and the interaction term of confusion and time delay were predictors in a support vector machine of cheating prediction with an average accuracy of 70.7%. The current algorithm could automatically flag suspicious student behavior for proctors in large scale online courses during remotely administered exams.
ContributorsChuang, Chia-Yuan (Author) / Femiani, John C. (Thesis advisor) / Craig, Scotty D. (Thesis advisor) / Bekki, Jennifer (Committee member) / Arizona State University (Publisher)
Created2015
Description
In this dissertation, organizational whistleblowing is guided by the methods for writing Creative Nonfiction. That is to say, a true story is told in a compelling and creative, easy to read manner, so that a broader audience, both academic and non-academic alike, can understand the stories told. For this project, analytic concepts such as antecedents, organizational culture, resistance and dissidence, social support, and ethics are embedded in the narrative text. In this piece, the author tells the story of a whistleblowing process, from beginning to end. Using the techniques advised by Gutkind (2012) questions and directions for research and analytic insight are integrated with the actual scenes of the whistleblowing account. The consequences of whistleblowing are explored, including loss of status, social isolation, and a variety of negative ramifications. In order to increase confidentiality in the dissertation, pseudonyms and adapted names and locations have been used to focus on the nature of the whistleblowing experience rather than the specific story. The author ends the dissertation with reflection on whistleblowing through the insight gathered from his firsthand account, suggesting advice for future whistleblowers and directions for future organizational research on whistleblowing.
ContributorsClow, Chase L (Author) / de la Garza, Amira (Thesis advisor) / Margolis, Eric (Committee member) / Quan, Helen (Committee member) / Arizona State University (Publisher)
Created2015
Description
ABSTRACT
This study examines the language and literacy experiences of Kurdish minority children during their first year of mainstream schooling in a southeastern village in Turkey. I employed ethnographic research methods (participant observation, multi-modal data collection, interviewing, and focus groups) to investigate the language practices of the children in relation to language ideologies circulating in the wider context. I focused on the perspectives and practices of one 1st grade classroom (14 students) but also talked with seven parents, three teachers, and two administrators.
A careful analysis of the data collected shows that there is a hierarchy among languages used in the community—Turkish, English, and Kurdish. The children, their parents, and their teachers all valued Turkish and English more than Kurdish. While explaining some of their reasons for this view, they discussed the status and functions of each language in society with an emphasis on their functions. My analysis also shows that, although participants devalue the Kurdish language, they still value Kurdish as a tie to their ethnic roots. Another key finding of this study is that policies that appear in teachers’ practices and the school environment seemed to be robust mediators of the language beliefs and practices of the Kurds who participated in my study. School is believed to provide opportunities for learning languages in ways that facilitate greater participation in society and increased access to prestigious jobs for Kurdish children who do not want to live in the village long-term. Related to that, one finding demonstrates that current circumstances make language choice like a life choice for Kurdish children. While Kurds who choose Turkish are often successful in school (and therefore have access to better jobs), the ones who maintain their Kurdish usually have only animal breeding or farming as employment options. I also found that although the Kurdish children that I observed subscribed to ideologies that valued Turkish and English over their native language, they did not entirely abandon their Kurdish language. Instead, they were involved in Turkish- Kurdish bilingual practices such as language broking, language sharing, and language crossing.
This study examines the language and literacy experiences of Kurdish minority children during their first year of mainstream schooling in a southeastern village in Turkey. I employed ethnographic research methods (participant observation, multi-modal data collection, interviewing, and focus groups) to investigate the language practices of the children in relation to language ideologies circulating in the wider context. I focused on the perspectives and practices of one 1st grade classroom (14 students) but also talked with seven parents, three teachers, and two administrators.
A careful analysis of the data collected shows that there is a hierarchy among languages used in the community—Turkish, English, and Kurdish. The children, their parents, and their teachers all valued Turkish and English more than Kurdish. While explaining some of their reasons for this view, they discussed the status and functions of each language in society with an emphasis on their functions. My analysis also shows that, although participants devalue the Kurdish language, they still value Kurdish as a tie to their ethnic roots. Another key finding of this study is that policies that appear in teachers’ practices and the school environment seemed to be robust mediators of the language beliefs and practices of the Kurds who participated in my study. School is believed to provide opportunities for learning languages in ways that facilitate greater participation in society and increased access to prestigious jobs for Kurdish children who do not want to live in the village long-term. Related to that, one finding demonstrates that current circumstances make language choice like a life choice for Kurdish children. While Kurds who choose Turkish are often successful in school (and therefore have access to better jobs), the ones who maintain their Kurdish usually have only animal breeding or farming as employment options. I also found that although the Kurdish children that I observed subscribed to ideologies that valued Turkish and English over their native language, they did not entirely abandon their Kurdish language. Instead, they were involved in Turkish- Kurdish bilingual practices such as language broking, language sharing, and language crossing.
ContributorsGokalp, Ayfer (Author) / Warriner, Doris S (Thesis advisor) / Mccarty, Teresa (Committee member) / Matsuda, Aya (Committee member) / Swadener, Beth B (Committee member) / Arizona State University (Publisher)
Created2015