Master of Science

thesisIn response to the growing need to understand individual differences in executive functioning (EF) among non-neurologic populations, this study examined two competing theoretical models of EF among healthy, neurologically-intact individuals: the prefrontal convexity model and the hemispheric asymmetry model. A total of 315 neurologically healthy individuals (M = 20.8 years; 50% female) completed two phases of the study. In the first phase (i.e., Model Identification), latent profile analysis was applied to variables measuring the abilities to form, switch, and maintain mental sets under conditions designed to tax the left or right hemisphere (i.e., a modified switching task). In the second phase (i.e., Model Validation), latent clusters from the first phase were compared on a separate EF task (i.e., Attention Network Test; ANT). The Model Identification phase yielded a three-profile solution consistent with the hemispheric asymmetry model. Profile 1 (N=203) was characterized by average EF performances. Profile 2 (N=43) revealed a set maintenance weakness under nonverbal conditions. Profile 3 (N=38) demonstrated a global weakness in cognitive flexibility and a specific weakness on tasks administered under verbal conditions. The Model Validation phase confirmed group/cluster differences (F(4,554) = 5.938, p<.001). Individual differences in EF follow a hemispheric asymmetry model of EF, with approximately 15% of neurologically healthy individuals exhibiting weaknesses in set maintenance and nonverbal processing, and 13% exhibiting weaknesses in set formation/switching and verbal processing

Doctor of Philosophy

dissertationMindfulness training appears to promote healthy and adaptive functioning by enhancing self-regulatory capacity and stress resilience. Less is known about whether dispositional mindfulness (DM) is similarly associated with self-regulatory capacity and stress resilience. Fifty-six healthy adults completed a self-report DM questionnaire and performance-based measures of executive function (EF) prior to daily life experience sampling of affect, self-regulation, presleep arousal, and sleep quality. DM was not associated with objective measures of EF but was significantly associated with self-reported cognitive, emotional, and behavioral self-regulation. Further, although DM was not associated with average affect levels (i.e., across positive/negative valence, low/high arousal domains), dispositionally high-mindful individuals exhibited less extreme changes in negative/low arousal affect (e.g., sad, bored) and negative/high arousal affect (e.g., stressed, angry) and evidenced less variability in positive/low arousal affect (e.g., relaxed, serene). Higher DM was also associated with lower presleep arousal and higher sleep quality. At the facet-level, mindful awareness was associated with daily self-reported EF and predicted cognitive presleep arousal and sleep quality; conversely, mindful acceptance was associated with greater stability across negatively valenced and low arousal affect states, and more strongly predicted somatic presleep arousal. Results indicate that mindful awareness and mindful acceptance, two distinct yet complementary processes, appear uniquely associated with components of self-regulation

The Forum: Fall 2003

Fall 2003 journal of the Honors Program at the University of North Dakota. The issue includes stories, poems, essays and art by undergraduate students.https://commons.und.edu/und-books/1052/thumbnail.jp

Functional Evolution of cis-Regulatory Modules at a Homeotic Gene in Drosophila

It is a long-held belief in evolutionary biology that the rate of molecular evolution for a given DNA sequence is inversely related to the level of functional constraint. This belief holds true for the protein-coding homeotic (Hox) genes originally discovered in Drosophila melanogaster. Expression of the Hox genes in Drosophila embryos is essential for body patterning and is controlled by an extensive array of cis-regulatory modules (CRMs). How the regulatory modules functionally evolve in different species is not clear. A comparison of the CRMs for the Abdominal-B gene from different Drosophila species reveals relatively low levels of overall sequence conservation. However, embryonic enhancer CRMs from other Drosophila species direct transgenic reporter gene expression in the same spatial and temporal patterns during development as their D. melanogaster orthologs. Bioinformatic analysis reveals the presence of short conserved sequences within defined CRMs, representing gap and pair-rule transcription factor binding sites. One predicted binding site for the gap transcription factor KRUPPEL in the IAB5 CRM was found to be altered in Superabdominal (Sab) mutations. In Sab mutant flies, the third abdominal segment is transformed into a copy of the fifth abdominal segment. A model for KRUPPEL-mediated repression at this binding site is presented. These findings challenge our current understanding of the relationship between sequence evolution at the molecular level and functional activity of a CRM. While the overall sequence conservation at Drosophila CRMs is not distinctive from neighboring genomic regions, functionally critical transcription factor binding sites within embryonic enhancer CRMs are highly conserved. These results have implications for understanding mechanisms of gene expression during embryonic development, enhancer function, and the molecular evolution of eukaryotic regulatory modules

Parental Perspectives on Communication from Health Care Providers following a Newborn Diagnosis of Congenital Cytomegalovirus Infection: A Secondary Analysis of a Qualitative Study

The study objective was to identify communication messages that parents of children diagnosed with congenital cytomegalovirus (cCMV) infection reported as essential and helpful. We performed a secondary analysis of focus groups and interviews conducted with 41 parents of children with cCMV who had enrolled in a long-term follow-up cCMV study at an academic medical center. Three groups of parents who had children with cCMV participated in the study: parents with children symptomatic at birth, parents with children asymptomatic at birth who later developed sensorineural hearing loss, and parents with children asymptomatic at birth who remained asymptomatic into adulthood. Using a health marketing approach, we identified six general themes from the focus group sessions: initial diagnosis, likely health outcome(s), comfort and coping, symptom watch, resources, and prevention. Receiving the initial diagnosis was shocking for many parents, and they wanted to know how their child would or could be affected. They valued access to the information, follow-up visits for early detection of hearing loss and other developmental delays, and support from other parents. Parents wished to obtain this information from their pediatrician but felt that experts offered more up-to-date knowledge about prognosis, monitoring, and treatment. With more U.S. states implementing cCMV screening strategies which would lead to more infant diagnoses, it will be necessary for providers to meet parents’ expectations and communication needs

Functional evolution of cis-regulatory modules at a homeotic gene in Drosophila.

It is a long-held belief in evolutionary biology that the rate of molecular evolution for a given DNA sequence is inversely related to the level of functional constraint. This belief holds true for the protein-coding homeotic (Hox) genes originally discovered in Drosophila melanogaster. Expression of the Hox genes in Drosophila embryos is essential for body patterning and is controlled by an extensive array of cis-regulatory modules (CRMs). How the regulatory modules functionally evolve in different species is not clear. A comparison of the CRMs for the Abdominal-B gene from different Drosophila species reveals relatively low levels of overall sequence conservation. However, embryonic enhancer CRMs from other Drosophila species direct transgenic reporter gene expression in the same spatial and temporal patterns during development as their D. melanogaster orthologs. Bioinformatic analysis reveals the presence of short conserved sequences within defined CRMs, representing gap and pair-rule transcription factor binding sites. One predicted binding site for the gap transcription factor KRUPPEL in the IAB5 CRM was found to be altered in Superabdominal (Sab) mutations. In Sab mutant flies, the third abdominal segment is transformed into a copy of the fifth abdominal segment. A model for KRUPPEL-mediated repression at this binding site is presented. These findings challenge our current understanding of the relationship between sequence evolution at the molecular level and functional activity of a CRM. While the overall sequence conservation at Drosophila CRMs is not distinctive from neighboring genomic regions, functionally critical transcription factor binding sites within embryonic enhancer CRMs are highly conserved. These results have implications for understanding mechanisms of gene expression during embryonic development, enhancer function, and the molecular evolution of eukaryotic regulatory modules