2020 MU theses - Access restricted to UM
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Item The convergence of mastery criteria and instructional format : a systematic review(University of Missouri--Columbia, 2020) Kraus, Samantha; Becerra, Lorraine A.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI SYSTEM AT AUTHOR'S REQUEST.] Applied Behavior Analysis (ABA) is a widely accepted science in which treatment for problem behavior reduction and skill acquisition interventions has been developed for learners diagnosed with autism spectrum disorder (ASD). Discrete Trial Training (DTT) is an effective teaching method within ABA that presents teaching targets in a rapid instructional format until a mastery criterion is met (Smith, 2001). Clinicians and researchers select instructional format and mastery criterion when designing the DTT protocol for their clients with ASD. Modifications in the instructional format present ratios of mastered teaching targets relative to targets in acquisition. Furthermore, the specified mastery criterion demonstrates when a skill is learned to sufficiency. The interaction of teaching format and mastery criteria options may impact the efficient acquisition and maintenance of the novel skills. The purpose of this review was to SYSTEM atically categorize and evaluate instructional format and mastery criteria within a discrete trial teaching procedure for learners with developmental disabilities. The review included 15 studies organized into the following categories: Mass trial, interspersed trial, and distributed trial, as well as mastery criteria. Task interspersal (75 [percent] of those that compared instructional format) and an 80 [percent] mastery criterion correct across 3 days or sessions (80 [percent] of those that compared mastery criteria) were the most commonly identified. However, there was extreme variability across studies and future research is needed to allow clinicians to form a rationale for their treatment modification selections. Clinical implications and future directions for research are discussed.Item A systematic review of the observer effect as a training methodology(University of Missouri--Columbia, 2020) Ebbers, Rebecca; Becerra, Lorraine A.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI SYSTEM AT AUTHOR'S REQUEST.] Within the field of applied behavior analysis, behavior analysts are service providers who routinely contribute collaboratively for the purpose of developing and evaluating treatment plans for children diagnosed with ASD. However, there is currently a lack of evidence-based and efficient training methodology aimed to teach critical vocal and non-vocal verbal behaviors necessary to successfully collaborate with other professionals. An efficient training methodology, the observer effect, has been demonstrated as a means of teaching a variety of novel skills across a range of populations. The purpose of this review was to evaluate and categorize the current literature pertaining to the observer effect. Within this SYSTEM atic review, the author assessed eighteen research articles for which the observer effect was utilized across different training formats. The articles assessed through this process demonstrated effectiveness in teaching a variety of skills across varying training modalities encompassing the observer effect. Avenues for future research and implications for developing training procedures are also included.Item Predictors of symptom course in alcohol use disorder(University of Missouri--Columbia, 2020) Conlin, William; Sher, Kenneth J.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI SYSTEM AT AUTHOR'S REQUEST.] Alcohol Use Disorder (AUD) has traditionally been viewed as a chronic, progressive, relapsing disorder (Jellinek, 1960; National Institute on Drug Abuse, 2018). However, research has found considerable variability in the course of AUD (Grant et al., 2012; Rohde et al., 2001; Verges et al., 2012). Even less is known about the course of individual AUD criteria. To the extent that individual symptoms represent the focus of some treatments (e.g., withdrawal, craving), understanding the course of specific criteria, and individual differences in symptom course, can inform treatment efforts and future research directions. The current study examined 34,653 participants form Wave 1 (2001-2002) and Wave 2 (2003-2004) of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC; Grant, Moore, and Kaplan, 2003; Grant, Kaplan, and Stinson, 2005), using logistic regression to analyze the extent in which AUD symptom course is predicted by alcohol consumption, family history of alcohol use disorders, and lifetime diagnosis of Conduct Disorder. The course of all AUD symptoms was significantly influenced by all four external criteria, with the magnitude of the prediction varying across different symptoms and different aspects of course. Heavy drinking was the strongest predictor of symptom course, and symptom onset was more strongly influenced by the four external predictors than symptom persistence and symptom recurrence. Not surprisingly, the course of all AUD symptoms was strongly associated with the prevalence of the given symptom in the overall population. A next step in understanding factors influencing symptom course is examining how individual symptoms can modify the course of other individual symptoms within these groups of at-risk drinkers.Item The progression of white matter abnormalities in individuals with early-treated phenylketonuria (PKU)(University of Missouri--Columbia, 2020) Clocksin, Hayley E.; Christ, Shawn E.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI SYSTEM AT AUTHOR'S REQUEST.] Phenylketonuria (PKU) is a rare autosomal recessive disorder characterized by a disruption in the ability to metabolize phenylalanine (phe) into tyrosine, a precursor for dopamine and other catecholamines. Even with early and continuous treatment, those with PKU exhibit cognitive and neurological sequelae, the most prominent of which is abnormalities of cortical white matter (WM). Past studies suggest that posterior WM is generally more compromised than anterior WM, but little is known regarding how this pattern of findings translates to potential impact along the spatial extent of individual WM tracts. The present study utilizes a new analysis approach called Automated Fiber-Tract Quantification (AFQ) to advance our understanding of the tract-specific progression of WM abnormalities in individuals with early-treated PKU (ETPKU). Diffusion Tensor Imaging (DTI) data from a sample of 22 individuals with ETPKU and a demographically-matched sample of 21 healthy individuals without PKU was analyzed using AFQ. In addition, a subsample of 8 individuals with ETPKU was reevaluated six months later after demonstrating a significant reduction in blood phe levels related to sapropterin treatment. Within-tract AFQ analyses revealed location-by-group interactions for several WM tracts throughout the brain. In most cases, ETPKU-related disruptions in mean diffusivity (MD) were more apparent in posterior (as compared to anterior) aspects of a given tract. This finding was more pronounced with increased age and higher phe levels. Significant reduction in blood phe levels was associated with a similar pattern of improvement (posterior-to-anterior) within most tracts. Taken together, these findings suggest that there is a SYSTEM atic progression of WM abnormalities in individuals with ETPKU in a posterior-to-anterior manner along individual WM tracts that mirrors the previously observed pattern of progression through the brain.Item Soybean resistance and yield response to southern root-knot nematode(University of Missouri--Columbia, 2020) Vieira, Caio Canella; Chen, Pengyin[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI SYSTEM AT AUTHOR'S REQUEST.] Soybean represents the largest and most concentrated segment of global agricultural trade. Despite its consistent yearly yield increment around the world, biotic stresses can limit soybean yield potential. Meloidogyne incognita (SRKN) is one of the most yield-suppressing pathogens in soybean in the United States and around the world. With limited chemical and cultural management options, the use of genetic resistance is the most efficient management approach. The major QTL on chromosome 10 is the primary source of SRKN resistance in soybean cultivars, however, limited studies evaluated its efficacy in minimizing yield suppression under field conditions. Additionally, limited QTL regulating resistance were identified in the soybean genome. Therefore, the objectives of this study were to evaluate the yield performance of SRKN resistant and susceptible soybean lines in field conditions with variable levels of SRKN pressure and perform a genome-wide association study to identify QTL regions regulating resistance. In environments with high SRKN pressure, resistant lines yielded on average 21.2 [percent] higher than the susceptible group. The presence of the major resistance QTL on chromosome 10 reduced yield losses by approximately 6-fold in comparison to the susceptible group (-0.0011 [percent] against -0.0062 [percent] per 1 SRKN second stage juvenile in 100 cm-3). Across all phenotypic inputs, a total of 37 significant SNPs that were associated with soybean resistance to M. incognita were identified on chromosomes 8, 9, 10, 13, 14, and 19. We identified nine regions across the soybean genome significantly associated with M. incognita resistance, including seven regions not previously reported in the literature.