Matching Items (399)
Description
Exploration of a mouse model (C57BL/6J) capable of demonstrating behavioral changes after adolescent social isolation that are consistent with prior findings may prove beneficial in later research. This study examined 2 proposed long-term effects of isolated housing (one mouse/cage), when compared to group housing (two mice/cage) during adolescence. Mice were placed in their respective housing conditions after weaning (PND 21) and remained in those conditions until PND 60. The same cohorts were used in both phases of the experiment. Phase 1 sought to confirm previous findings that showed increases in ethanol intake after adolescent social isolation using a 2-bottle preference Drinking-in-the-Dark (DID) design over a 4-day period (PND 64-PND 67.). Phase 2 sought to elucidate the effects present after adolescent social isolation, as measured using response inhibition capabilities demonstrated during fixed-minimum interval (FMI) trials (PND 81-PND 111). Findings in phase 1 of the experiment were non-significant, save a strong tendency for female mice in both housing conditions to drink more as a proportion of their bodyweight (g/kg). However, a trend of lower bodyweight in single housed mice did exist, which does suggest that detrimental stress was applied via the used of adolescent isolation in that housing condition. Findings in phase 2 showed little effect of adolescent social isolation on mean inter-response time (IRT) at any criterion used (FMI-0, FMI-4, FMI-6). Evaluation of mean interquartile range (IQR) of IRTs showed a significantly greater amount of variation in IRT responses within single housed mice at the highest criterion (FMI-6), and a trend in the same direction when FMI-4 and FMI-6 were tested concurrently. Taken as a whole, the findings of this experiment suggest that the effect of adolescent social isolation on ethanol intake is far less robust than the effect of sex and may be difficult to replicate in a low-power study. Additionally, adolescent social isolation may interfere with the ability of mice to show consistent accuracy during FMI tasks or a delay in recognition of FMI criterion change.
ContributorsSmith, Nathaniel B (Author) / Sanabria, Federico (Thesis director) / Olive, Foster (Committee member) / Corbin, William (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
The rising national maternal mortality rate has brought international attention to the United State's maternal healthcare crisis. This literature review consolidates and compares academic research on the best practices for lowering maternal mortality rates and reducing racial disparities in healthcare.
ContributorsDavey, Skylar Lauren (Author) / O'Flaherty, Katherine (Thesis director) / Lynch, Jacquie (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Midlife is a unique period of development during which individuals are simultaneously engaging in multiple roles. Despite this, there is a surprisingly small amount of research on this period of the life course. In order to examine sources of adversity during this period, we analyzed interviews with individuals in midlife about their greatest challenge. The most common themes for types of adversity included relationships, health, and work, reflecting the unique combination of roles in midlife.
ContributorsMattern, Cameron Michele (Author) / Infurna, Frank (Thesis director) / Corbin, William (Committee member) / Grimm, Kevin (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This thesis focuses on the theoretical work done to determine thermodynamic properties of a chalcopyrite thin-film material for use as a photovoltaic material in a tandem device. The material of main focus here is ZnGeAs2, which was chosen for the relative abundance of constituents, favorable photovoltaic properties, and good lattice matching with ZnSnP2, the other component in this tandem device. This work is divided into two main chapters, which will cover: calculations and method to determine the formation energy and abundance of native point defects, and a model to calculate the vapor pressure over a ternary material from first-principles. The purpose of this work is to guide experimental work being done in tandem to synthesize ZnGeAs2 in thin-film form with high enough quality such that it can be used as a photovoltaic. Since properties of photovoltaic depend greatly on defect concentrations and film quality, a theoretical understanding of how laboratory conditions affect these properties is very valuable. The work done here is from first-principles and utilizes density functional theory using the local density approximation. Results from the native point defect study show that the zinc vacancy (VZn) and the germanium antisite (GeZn) are the more prominent defects; which most likely produce non-stoichiometric films. The vapor pressure model for a ternary system is validated using known vapor pressure for monatomic and binary test systems. With a valid ternary system vapor pressure model, results show there is a kinetic barrier to decomposition for ZnGeAs2.
ContributorsTucker, Jon R (Author) / Van Schilfgaarde, Mark (Thesis advisor) / Newman, Nathan (Committee member) / Adams, James (Committee member) / Arizona State University (Publisher)
Created2011
Description
The purpose of our study was to examine the effectiveness of a cycling intervention on body composition in adolescents with Down syndrome (DS). Participants completed one of three interventions over eight consecutive weeks. The interventions were: 1) Voluntary Cycling (VC), in which participants cycled at their self-selected pedaling rate 2) Assisted Cycling (AC), in which the participants' voluntary pedaling rates were assisted with a motor to ensure the maintenance of 80 rpms. 3) No cycling (NC), in which the participants acted as controls. Participants in the AC intervention did not decrease body fat or increase lean body mass however they did maintain these measures during the intervention as compared to the VC and NO participants who increased body fat and decreased lean body mass. These statistics were not exactly as expected nor were they statistically significant. Future research will try to replicate this data with statistically significant values for more cycling adolescents with DS using more randomized intervention groups.
ContributorsBennett, Kristen Leigh (Author) / Ringenbach, Shannon (Thesis director) / Brown, Steven (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
This research study examined the effects of assisted cycling using a stationary recumbent bicycle that had an internal motor to help participants pedal at a desired cadence. The participants were either placed in an Assisted Cycling (AC), Voluntary Cycling (VC), or No Cycling (NC) intervention group. Those placed in the AC of VC groups then came to a laboratory setting 3 days a week for 8 weeks to cycle for 30 minutes. This research specifically analyzes the Vineland Adaptive Behavior Scale II to analyze the changes in daily living skills and maladaptive behaviors pre and post the exercise intervention. After analyzing the VABS II scores it was found that those in the VC intervention had statistically significant improvements in maladaptive behaviors. An interpretation of this finding is that the VC intervention had an increased heart rate over the span of the intervention and had a larger power output than those in the AC group. A limitation of this research is that it was a self-reported questionnaire that was given to the caregivers of the participant. The caregivers were not always controlled for, so in some cases two different caregivers were given the questionnaire for a single participant. A suggestion for future research would be to use the participant's mental age versus their chronological age when using the VABS-II and to use the Adaptive Behaviors Assessment System III (ABAS-III).
ContributorsJenkins, Cayla Marie (Author) / Ringenbach, Shannon (Thesis director) / Kulinna, Pamela (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
Electromigration in metal interconnects is the most pernicious failure mechanism in semiconductor integrated circuits (ICs). Early electromigration investigations were primarily focused on aluminum interconnects for silicon-based ICs. An alternative metallization compatible with gallium arsenide (GaAs) was required in the development of high-powered radio frequency (RF) compound semiconductor devices operating at higher current densities and elevated temperatures. Gold-based metallization was implemented on GaAs devices because it uniquely forms a very low resistance ohmic contact and gold interconnects have superior electrical and thermal conductivity properties. Gold (Au) was also believed to have improved resistance to electromigration due to its higher melting temperature, yet electromigration reliability data on passivated Au interconnects is scarce and inadequate in the literature. Therefore, the objective of this research was to characterize the electromigration lifetimes of passivated Au interconnects under precisely controlled stress conditions with statistically relevant quantities to obtain accurate model parameters essential for extrapolation to normal operational conditions. This research objective was accomplished through measurement of electromigration lifetimes of large quantities of passivated electroplated Au interconnects utilizing high-resolution in-situ resistance monitoring equipment. Application of moderate accelerated stress conditions with a current density limited to 2 MA/cm2 and oven temperatures in the range of 300°C to 375°C avoided electrical overstress and severe Joule-heated temperature gradients. Temperature coefficients of resistance (TCRs) were measured to determine accurate Joule-heated Au interconnect film temperatures. A failure criterion of 50% resistance degradation was selected to prevent thermal runaway and catastrophic metal ruptures that are problematic of open circuit failure tests. Test structure design was optimized to reduce resistance variation and facilitate failure analysis. Characterization of the Au microstructure yielded a median grain size of 0.91 ìm. All Au lifetime distributions followed log-normal distributions and Black's model was found to be applicable. An activation energy of 0.80 ± 0.05 eV was measured from constant current electromigration tests at multiple temperatures. A current density exponent of 1.91 was extracted from multiple current densities at a constant temperature. Electromigration-induced void morphology along with these model parameters indicated grain boundary diffusion is dominant and the void nucleation mechanism controlled the failure time.
ContributorsKilgore, Stephen (Author) / Adams, James (Thesis advisor) / Schroder, Dieter (Thesis advisor) / Krause, Stephen (Committee member) / Gaw, Craig (Committee member) / Arizona State University (Publisher)
Created2013
Description
Past literature has indicated that the majority of people with alcohol problems never seek treatment and that this is especially true of women. Relatively few studies have investigated how different types of alcohol-related consequences longitudinally predict men and women's perceived need for treatment and their utilization of treatment services. The current study sought to expand the literature by examining whether gender moderates the links between four frequently endorsed types of consequences and perceived need for or actual utilization of treatment. Two-hundred thirty-seven adults ages 21-36 completed a battery of questionnaires at two time points five years apart. Results indicated that there were four broad types of consequences endorsed by both men and women. Multiple-group models and Wald chi square tests indicated that there were no significant relationships between consequences and treatment outcomes. No gender moderation was found but post-hoc power analyses indicated that the study was underpowered to detect moderation. Researchers need to continue to study factors that predict utilization of alcohol treatment services and the process of recovery so that treatment providers can better address the needs of people with alcohol-related consequences in the areas of referral procedures, clinical assessment, and treatment service provision and planning.
ContributorsBeltran Gonzalez, Iris (Author) / Chassin, Laurie (Thesis advisor) / Tein, Jenn-Yun (Committee member) / Corbin, William (Committee member) / Barrera, Jr., Manuel (Committee member) / Arizona State University (Publisher)
Created2013
Description
Levels of heavy episodic drinking peak during emerging adulthood and contribute to the experience of negative consequences. Previous research has identified a number of trait-like personality characteristics that are associated with drinking. Studies of the Acquired Preparedness Model have supported positive expectancies, and to a lesser extent negative expectancies, as mediators of the relation between trait-like characteristics and alcohol outcomes. However, expectancies measured via self-report may reflect differences in learned expectancies in spite of similar alcohol-related responses, or they may reflect true individual differences in subjective responses to alcohol. The current study addressed this gap in the literature by assessing the relative roles of expectancies and subjective response as mediators within the APM in a sample of 236 emerging adults (74.7% male) participating in a placebo-controlled alcohol challenge study. The study tested four mediation models collapsed across beverage condition as well as eight separate mediation models with four models (2 beverage by 2 expectancy/subjective response) for each outcome (alcohol use and alcohol-related problems). Consistent with previous studies, SS was positively associated with alcohol outcomes in models collapsed across beverage condition. SS was also associated with positive subjective response in collapsed models and in the alcohol models. The hypothesized negative relation between SS and sedation was not significant. In contrast to previous studies, neither stimulation nor sedation predicted either weekly drinking or alcohol-related problems. While stimulation and alcohol use appeared to have a positive and significant association, this relation did not hold when controlling for SS, suggesting that SS and stimulation account for shared variability in drinking behavior. Failure to find this association in the placebo group suggests that, while explicit positive expectancies are related to alcohol use after controlling for levels of sensation seeking, implicit expectancies (at least as assessed by a placebo manipulation) are not. That the relation between SS and stimulation held only in the alcohol condition in analyses separate by beverage condition indicates that sensation seeking is a significant predictor of positive subjective response to alcohol (stimulation), potentially above and beyond expectancies.
ContributorsScott, Caitlin (Author) / Corbin, William (Thesis advisor) / Shiota, Michelle (Committee member) / Chassin, Laurie (Committee member) / Arizona State University (Publisher)
Created2012
Description
This thesis is a qualitative research study that focuses on siblings of children with Autistic Spectrum Disorder (ASD). Even though it is expected that having a child with ASD in the family will influence the whole family including siblings of the child with ASD, the sibling population is rarely included in research related to children with ASD, and there is only limited services available for them. This exploratory study (n=6) is aimed at better understanding the siblings' lives in their family settings in order to identify the siblings' unmet needs and determine how they have been influenced by the child with ASD. This study is also aimed at identifying the most appropriate support for the siblings to help them cope better. The study followed the Resiliency Model of Family Stress, Adjustment, and Adaptation and a narrative theory approach. An in-depth interview with the parents was conducted for the study, so the findings reflect the parents' perception of the siblings. All the themes emerged into two categories: life in the family setting and supports. The findings indicate that the families are striving for balance between the siblings and the children with ASD, but still tend to focus more on the children with ASD. Also, the families tend to have autonomous personal support systems. The parents tend to perceive that these personal support systems are good enough for the siblings; therefore, the parents do not feel that formal support for the siblings was necessary. As a result of the findings, recommendations are made for the organizations that work with individuals with ASD to provide more appropriate services for the families of children with ASD, including siblings. Also, recommendations are made for future studies to clarify more factors related to the siblings due to the limitation of this study; the siblings' lives were reflected vicariously via the parents.
ContributorsJeong, Seong Hae (Author) / Marsiglia, Flavio F (Thesis advisor) / Ayers, Stephanie (Committee member) / Adams, James (Committee member) / Arizona State University (Publisher)
Created2013