Matching Items (5)
Filtering by
- Genre: Doctoral Dissertation
Description
Childhood Apraxia of Speech (CAS) is a severe motor speech disorder that is difficult to diagnose as there is currently no gold-standard measurement to differentiate between CAS and other speech disorders. In the present study, we investigate underlying biomarkers associated with CAS in addition to enhanced phenotyping through behavioral testing. Cortical electrophysiological measures were utilized to investigate differences in neural activation in response to native and non-native vowel contrasts between children with CAS and typically developing peers. Genetic analysis included full exome sequencing of a child with CAS and his unaffected parents in order to uncover underlying genetic variation that may be causal to the child’s severely impaired speech and language. Enhanced phenotyping was completed through extensive behavioral testing, including speech, language, reading, spelling, phonological awareness, gross/fine motor, and oral and hand motor tasks. Results from cortical electrophysiological measures are consistent with previous evidence of a heightened neural response to non-native sounds in CAS, potentially indicating over specified phonological representations in this population. Results of exome sequencing suggest multiple genetic variations contributing to the severely affected phenotype in the child and provide further evidence of heterogeneous genomic pathways associated with CAS. Finally, results of behavioral testing demonstrate significant impairments evident across tasks in CAS, suggesting underlying sequential processing deficits in multiple domains. Overall, these results have the potential to delineate functional pathways from genetic variations to the brain to observable behavioral phenotypes and motivate the development of preventative and targeted treatment approaches.
ContributorsVose, Caitlin (Author) / Peter, Beate (Thesis advisor) / Liu, Li (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2018
Description
Purpose: The purpose of this study was to evaluate the efficacy of the EMBRACE Spanish support intervention for at-risk dual language learners and to determine which verbal and nonverbal characteristics of students were related to benefit from the intervention. The first study examined oral language and reading characteristics and the second study examined motor characteristics in predicting the children's outcomes on a reading comprehension intervention.
Method: Fifty-six participants in 2nd-5th grade were randomly assigned to one of two groups: 1) Spanish-support intervention, or 2) Spanish-support control. Outcome measures included performance on comprehension questions related to intervention texts, questions on the final narrative and expository text without strategy instruction, and difference scores on alternate forms of the Gates-MacGinitie (GMRT-4, MacGinitie, MacGinitie, Maria, & Dreyer, 2002) reading comprehension subtest administered pre- post-intervention. Multi-level hierarchical linear models were used to account for nesting of question within child within classroom. Regression models were used to examine the power of motor predictors in predicting Spanish and English language performance.
Results: Results from study 1 indicated that the intervention was most effective for narrative (vs. expository) texts and easy (vs. more difficult) texts. Dual language learners (DLLs) with lower initial English reading comprehension abilities benefitted more from the intervention than those with stronger reading skills. Results from Study 2 indicated that oral fine motor abilities predicted Spanish (but not English) oral language abilities in the expected direction (i.e. faster performance associated with higher language scores). The speed of /pata/ productions predicted reading comprehension during the intervention, but not in the expected direction (i.e. slower speeds associated with higher accuracy). Manual fine motor performance on tapping tasks was not related to language or reading.
Conclusions: The EMBRACE intervention has promise for use with at-risk DLLs. Future research should take care to match text difficulty with child skills so as to maximize benefit from the intervention. Oral fine motor abilities were related to language abilities in DLLs, but only for the native language. Slower oral fine motor performance predicted higher accuracy on intervention questions, suggesting that EMBRACE may be particularly effective for children with weak fine motor skills.
Method: Fifty-six participants in 2nd-5th grade were randomly assigned to one of two groups: 1) Spanish-support intervention, or 2) Spanish-support control. Outcome measures included performance on comprehension questions related to intervention texts, questions on the final narrative and expository text without strategy instruction, and difference scores on alternate forms of the Gates-MacGinitie (GMRT-4, MacGinitie, MacGinitie, Maria, & Dreyer, 2002) reading comprehension subtest administered pre- post-intervention. Multi-level hierarchical linear models were used to account for nesting of question within child within classroom. Regression models were used to examine the power of motor predictors in predicting Spanish and English language performance.
Results: Results from study 1 indicated that the intervention was most effective for narrative (vs. expository) texts and easy (vs. more difficult) texts. Dual language learners (DLLs) with lower initial English reading comprehension abilities benefitted more from the intervention than those with stronger reading skills. Results from Study 2 indicated that oral fine motor abilities predicted Spanish (but not English) oral language abilities in the expected direction (i.e. faster performance associated with higher language scores). The speed of /pata/ productions predicted reading comprehension during the intervention, but not in the expected direction (i.e. slower speeds associated with higher accuracy). Manual fine motor performance on tapping tasks was not related to language or reading.
Conclusions: The EMBRACE intervention has promise for use with at-risk DLLs. Future research should take care to match text difficulty with child skills so as to maximize benefit from the intervention. Oral fine motor abilities were related to language abilities in DLLs, but only for the native language. Slower oral fine motor performance predicted higher accuracy on intervention questions, suggesting that EMBRACE may be particularly effective for children with weak fine motor skills.
ContributorsAdams, Ashley (Author) / Restrepo, Maria Adelaida (Thesis advisor) / Glenberg, Arthur (Committee member) / Connor, Carol M (Committee member) / Peter, Beate (Committee member) / Arizona State University (Publisher)
Created2017
Description
It is common to use crumb rubber as modifier in bitumen. Good performance of crumb rubber in bitumen has been reported in terms of improving characteristics like higher skid resistance, reducing noise, higher rutting resistance and longevity. However, due to the vulcanization, the polymeric crosslinked structure of crumb rubber suffers from inadequate dispersion and incompatibility in bitumen where storage stability becomes an issue. To solve this problem, partial surface devulcanization of the rubber via chemical and microbial surface activation was examined in this study showing both method can be effective to enhance rubber-bitumen interactions and subsequently storage stability of the rubberized bitumen. To ensure proper surface activation, it is important to thoroughly understand chemo-mechanics of bitumen containing rubber particles as well as underlying interaction mechanism at the molecular level. Therefore, this study integrates a multi-scale approach using density functional theory based computational modeling and laboratory experiments to provide an in-depth understanding of the mechanisms of interaction between surface activated rubber and bitumen. To do so, efficacy of various bio-modifiers was examined and compared it terms of both surface activation capability and durability of resulting rubberized bitumen. It was found that biomodifiers with various compositions can have either synergistic or antagonistic effect onchemo-mechanics of rubberized bitumen. The study was further extended to study the interplay of Polyphosphoric Acid (PPA) and these biomodified rubberized bitumens showing not all modifiers have high synergy with PPA in bitumens. Finally, durability of rubberized bitumen was studied in terms of its resistance to Ultraviolet (UV) aging. It was shown that there is a strong relation between composition of biomodified rubberized bitumen and its resistance to UV-aging.
ContributorsKabir, Sk Faisal (Author) / Fini, Elham (Thesis advisor) / Kaloush, Kamil (Committee member) / Lamanna, Anthony (Committee member) / Delgado, Anca (Committee member) / Poulikakos, Lily (Committee member) / Arizona State University (Publisher)
Created2020
Description
The International Energy Agency (IEA) anticipates the global energy demand to grow by more than 25% by 2040, requiring more than $2 trillion a year of investment in new energy supply (IEA, 2018). With power needs increasing as populations grow and climate extremes become more routine, power companies seek to continually increase capacity, improve efficiency, and provide resilience to the power grid, such that they can meet the energy needs of the societies they serve, often while trying to minimize their carbon emissions. Despite significant research dedicated to planning for industrial projects, including power generation projects as well as the pipeline projects that enable power generation and distribute power, there are still endemic cost overruns and schedule delays in large scale power generation projects. This research explores root causes of these seemingly systemic project performance issues that plague power generation projects. Specifically, this work analyzes approximately 770 power and pipeline projects and identifies how project performance indicators (i.e., cost and schedule performance) as well as planning indicators, compare in two regulatory environments, namely nonregulated and regulated markets. This contributes explicit understanding of the relationship between project performance and regulatory environment, both quantitatively and qualitatively, to the pipeline and power project planning and construction bodies of knowledge. Following an understanding of nonregulated versus regulated markets, this research takes a deeper dive into one highly-regulated power sector, the nuclear power sector, and explores root causes for cost overruns and schedule delays. This work leverages gray literature (i.e., newspaper articles) as sources, in order to analyze projects individually (most academic literature presents data about an aggregated set of projects) and understand the public perception of risks associated with such projects. This work contributes an understanding of the risks associated with nuclear power plant construction to the nuclear power plant construction body of knowledge. Ultimately, the findings from this research support improved planning for power and pipeline projects, in turn leading to more predictable projects, in terms of cost and schedule performance, regardless of regulatory environment. This enables power providers to meet the capacity demands of a growing population within budget and schedule.
ContributorsSherman, Rachael Paige (Author) / Parrish, Kristen (Thesis advisor) / Gibson Jr., G. Edward (Committee member) / Lamanna, Anthony (Committee member) / Arizona State University (Publisher)
Created2020
Description
Speech sound disorders (SSDs) are the most prevalent type of communication disorder in children. Clinically, speech-language pathologists (SLPs) rely on behavioral methods for assessing and treating SSDs. Though clients typically experience improved speech outcomes as a result of therapy, there is evidence that underlying deficits may persist even in individuals who have completed treatment for surface-level speech behaviors. Advances in the field of genetics have created the opportunity to investigate the contribution of genes to human communication. Due to the heterogeneity of many communication disorders, the manner in which specific genetic changes influence neural mechanisms, and thereby behavioral phenotypes, remains largely unknown. The purpose of this study was to identify genotype-phenotype associations, along with perceptual, and motor-related biomarkers within families displaying SSDs. Five parent-child trios participated in genetic testing, and five families participated in a combination of genetic and behavioral testing to help elucidate biomarkers related to SSDs. All of the affected individuals had a history of childhood apraxia of speech (CAS) except for one family that displayed a phonological disorder. Genetic investigation yielded several genes of interest relevant for an SSD phenotype: CNTNAP2, CYFIP1, GPR56, HERC1, KIAA0556, LAMA5, LAMB1, MDGA2, MECP2, NBEA, SHANK3, TENM3, and ZNF142. All of these genes showed at least some expression in the developing brain. Gene ontology analysis yielded terms supporting a genetic influence on central nervous system development. Behavioral testing revealed evidence of a sequential processing biomarker for all individuals with CAS, with many showing deficits in sequential motor skills in addition to speech deficits. In some families, participants also showed evidence of a co-occurring perceptual processing biomarker. The family displaying a phonological phenotype showed milder sequential processing deficits compared to CAS families. Overall, this study supports the presence of a sequential processing biomarker for CAS and shows that relevant genes of interest may be influencing a CAS phenotype via sequential processing. Knowledge of these biomarkers can help strengthen precision of clinical assessment and motivate development of novel interventions for individuals with SSDs.
ContributorsBruce, Laurel (Author) / Peter, Beate (Thesis advisor) / Daliri, Ayoub (Committee member) / Liu, Li (Committee member) / Scherer, Nancy (Committee member) / Weinhold, Juliet (Committee member) / Arizona State University (Publisher)
Created2020