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- Creators: School of Molecular Sciences
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Description
This dissertation used an evolutionary approach to examine the antecedents and outcomes to early pubertal development in girls in four major ethnic groups (i.e., European American, African American, Hispanic American, and Asian American). In the first study, logistic regressions were conducted to investigate the links between socioeconomic status (SES), parenting behaviors, and father absence to pubertal development across and within ethnic groups. SES and father absence predicted earlier pubertal development among European, African, and Hispanic Americans but not for Asian Americans. In the second study, growth curves were estimated for sexual outcomes across ethnic groups. Early developing European and African American girls had higher levels of sexual risk and pregnancy into adulthood. Puberty did not predict outcomes for Hispanic and Asian American girls. Overall, the findings from both studies revealed the importance of investigating childhood environmental contexts, puberty, and sexual health outcomes using an evolutionary perspective.
ContributorsBecnel, Jennifer (Author) / Simpkins, Sandra (Thesis advisor) / Christopher, Scott (Thesis advisor) / Dumka, Larry (Committee member) / Updegraph, Kim (Committee member) / Arizona State University (Publisher)
Created2013
Description
Recent reports have indicated that there are both mental health and educational disparities between Latino youth and their European American counterparts. Specifically, Latin youth are at a heightened risk for negative mental health outcomes in comparison to their non-Latino youth (e.g., Eaton et al., 2008). Further, 16.7% of Latino adolescents dropped out of high school compared to 5.3% of European American youth over the past several decades (1960-2011; U.S. Department of Education, 2013). Mexican American (M.A. youth in particular, have the lowest educational attainment among all Latino ethnic groups in the U.S. (U.S. Census Bureau, 2010). While these mental health and educational disparities have often been attributed to discrimination experiences that Latino youth encounter, there is also consistent empirical evidence linking discrimination with these maladjustment problems. These studies confirmed that discrimination directly related to depressive symptoms (e.g., Umana-Taylor et al., 2007), externalizing behaviors (Berkel et al., 2010), self-esteem (e.g., Zeiders et al., 2013), and academic outcomes (e.g., Umana-Taylor et al., 2012). Few studies to date have examined the underlying mechanisms (i.e., moderation and mediation) that help us to better understand resiliency paths for those Latino youth that display positive adjustment outcomes despite being faced with similar discrimination encounters that their maladjusted peers face. Therefore, the following two studies examined various mechanisms in which discrimination related to adjustment to better understand potential risk and resiliency processes in hopes of informing intervention research. Paper 1 explored cultural influences on the association between discrimination, active coping, and mental health outcomes in M.A. youth. Paper 2 examined how trajectories of discrimination across 5th, 7th, and 10th grades related to cultural values, externalizing behaviors, and academic outcomes in M.A. youth. Taken together, these studies provide a culturally informed overview of adjustment processes in M.A. adolescents who face discrimination in addition to identifying critical directions for future research in efforts to gaining a more contextualized and comprehensive understanding of the dynamic processes involved in discrimination and adjustment in M.A. youth.
ContributorsO'Donnell, Megan (Author) / Roosa, Mark W. (Thesis advisor) / Dumka, Larry (Committee member) / Gonzales, Nancy (Committee member) / Barrera, Manuel (Committee member) / Arizona State University (Publisher)
Created2014
Description
Early Childhood Education (ECE) classroom quality has been gaining increased attention from researchers and policy makers, as the link between high quality early learning experiences and future success has become clear. The impact of ECE may be particularly important for low-income, ethnic minority youth, who may need additional support to reach the academic level of their higher-income, Caucasian peers. However, the definition of ECE quality does not currently include indicators of classroom practices and center-wide policies that intentionally address issues of culture, race, and ethnicity, topics that may be particularly relevant for the most academically at-risk children. Anti-bias education (ABE) provides a strong theoretical and practical framework for understanding how to incorporate such themes into classroom practice and policy, as well as how to teach students to actively counteract bias and discrimination. However, there is currently no mechanism for researchers to utilize this framework, because there is no measure that can reliably evaluate the level of quality of ABE practices. Therefore, the present study sought to incorporate anti-bias education principles into the conceptualization of classroom quality through measurement development. The measure was developed based on the integration of the original ABE theory with interviews and observations in five ECE programs, which were nominated for their intentional practices regarding issues of culture, race, and ethnicity in the classroom. The five centers ranged in the ethnic composition and average income of their population. The resulting measure contains five domains, with a number of items within each domain. Two of the domains (Toys & Materials, Visual/Aesthetic Environment) contain observational rubrics for assessment, whereas the other three (Organizational Climate, Activities, Interactions) include self-report scales in addition to the rubrics. Future research is needed to pilot the measure and establish validity and reliability across contexts and observation times.
ContributorsGaias, Larissa Michelle (Author) / Dumka, Larry (Thesis advisor) / Shivers, Eva M (Committee member) / Simpkins, Sandra (Committee member) / Arizona State University (Publisher)
Created2015
Description
Identity theorists have emphasized the importance of integration across identity domains for psychosocial well-being. There remains little research, however, on associations across identity domains, group differences across identity profiles, and the joint association of multiple identity domains with academic outcomes. This dissertation includes two studies that address these limitations in the identity literature. Study 1, examined the ego-social identity profiles that emerged from ethnic identity exploration and commitment, American identity exploration and commitment, and ego identity integration and confusion among an ethnically diverse sample of emerging adults using latent profile analysis (N = 8,717). Results suggested that an eight-profile solution was the best fit for the data. The profiles demonstrated differences in identity status and salience across identity domains. Significant ethnic, sex, nativity, and age differences were identified in ego-social identity membership. Study 2 focused on the ego-social identity profiles that emerged from the same identity domains among biethnic college students of Latino and European American heritage (N = 401) and how these profiles differed as a function of preferred ethnic label. The association of ego-social identity profile with academic achievement and the moderation by university ethnic composition were examined. Results indicated that a two-profile solution was the best fit to the data in which one profile included participants with general identity achievement across identity domains and one profile included individuals who were approaching the identity formation process in each domain. Ego-social identity profile membership did not differ based on preferred ethnic label. Individuals who had a more integrated identity across domains had higher college grades. University ethnic composition did not significantly moderate this association. Taken together, these two studies highlight the intricacies of identity formation that are overlooked when integration across identity domains is not considered.
ContributorsGonzales-Backen, Melinda Airr (Author) / Dumka, Larry (Thesis advisor) / Millsap, Roger (Committee member) / Roosa, Mark (Committee member) / Yoo, Hyung Chol (Committee member) / Arizona State University (Publisher)
Created2012
Description
Relational turbulence theory (RTT) has primarily explored the effects of relational uncertainty and partner interdependence on relational outcomes. While robust, the theory fails to account for uncertainties and perceived interdependence stemming from extra-dyadic factors (such as partners’ social networks). Thus, this dissertation had two primary goals. First, scales indexing measures of social network-based relational uncertainty (i.e., network uncertainty) and social network interdependence are tested for convergent and divergent validity. Second, measurements of network uncertainty and interdependence are tested alongside measures featured in RTT to explore predictive validity. Results confirmed both measurements and demonstrated numerous significant relationships for turbulence variables. Discussions of theoretical applications and future directions are offered.
ContributorsStein, James (Author) / Mongeau, Paul A. (Thesis advisor) / Guerrero, Laura (Committee member) / Dumka, Larry (Committee member) / Arizona State University (Publisher)
Created2018
Description
Breast microcalcifications are a potential indicator of cancerous tumors. Current visualization methods are either uncomfortable or impractical. Impedance measurement studies have been performed, but not in a clinical setting due to a low sensitivity and specificity. We are hoping to overcome this challenge with the development of a highly accurate impedance probe on a biopsy needle. With this technique, microcalcifications and the surrounding tissue could be differentiated in an efficient and comfortable manner than current techniques for biopsy procedures. We have developed and tested a functioning prototype for a biopsy needle using bioimpedance sensors to detect microcalcifications in the human body. In the final prototype a waveform generator sends a sin wave at a relatively low frequency(<1KHz) into the pre-amplifier, which both stabilizes and amplifies the signal. A modified howland bridge is then used to achieve a steady AC current through the electrodes. The voltage difference across the electrodes is then used to calculate the impedance being experienced between the electrodes. In our testing, the microcalcifications we are looking for have a noticeably higher impedance than the surrounding breast tissue, this spike in impedance is used to signal the presence of the calcifications, which are then sampled for examination by radiology.
ContributorsWen, Robert Bobby (Co-author) / Grula, Adam (Co-author) / Vergara, Marvin (Co-author) / Ramkumar, Shreya (Co-author) / Kozicki, Michael (Thesis director) / Ranjani, Kumaran (Committee member) / School of Molecular Sciences (Contributor) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Breastfeeding has been shown by a number of studies to have numerous benefits on both the mother and the infant. Major health organizations such as the World Health Organization (WHO), now agree that breastfeeding should be encouraged and supported in all countries. But like many things, the wheels of the law are slow to catch up with scientific evident. Although breastfeeding is supported, working women do not have the option of breastfeeding without consequences. For example, in 2003, Kirstie Marshall, a then member of parliament in Australia was ejected from the lower house chamber on February 23, for breastfeeding her baby [3]. According to standing order 30 at the time, "Unless by order of the House, no Member of this House shall presume to bring any stranger into any part of the House appropriated to the Members of this House while the House, or a Committee of the whole House, is sitting" [3]. The rules did not specify the age of strangers, so the then 11-day-old baby, Charlotte Louise and her mother were shown the exit door of parliament. She had to choose between being present at times of major discussions or leaving the house to breastfeed her child, she chose to leave. More recent statistics show that developed nations like the US and Australia which also have high rates of women employment had low rates of breastfeeding. This might mean that workplace policies do not favor breastfeeding or expressing milk at work. Fortunately, laws have since been introduced in both the United States and Australia that support breastfeeding at the workplace. The next step would be to access how these laws affect breastfeeding statistics and how variation between these two countries like the paid parental leave in Australia (which is not present in all US states) would affect these numbers.
ContributorsSakala, Lydia (Author) / Alison, Alison (Thesis director) / Reddy, Swapna (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Ketone bodies are produced in the liver from the acetyl CoA derived from fatty acids that cannot enter the Krebs cycle. This is a sub-analysis of a larger study which had numerous outcome markers. This analysis focuses on the relationship between ketone blood levels and cognition. The study looked at the relationship between Time Restricted Feeding (TRF), a method of intermittent fasting. TRF is something that can be easily adapted into an individual’s lifestyle and has been shown to have multiple advantages. This 8-week study began with 23 enrolled participants, but due to COVID-19 only 11 participants could be tested for cognition and blood ketone levels after week 4. All participants had similar ranges of weight, height, age, BMI, hip, and waist measurements at baseline. Moreover, these demographic variables were not related to ketone levels or cognition. The data indicate that ketone bodies increased in participants practicing TRF and that the increase in ketone bodies in the blood, specifically β-hydroxybutyrate was strongly correlated to increased cognitive function. This is consistent with theories that elevated ketone levels allowed for early hunter-gather communities and other mammals to survive prolonged periods of nutrient deprivation while keeping high cognitive function.
ContributorsTaha, Basel Mahmoud (Author) / Johnston, Carol (Thesis director) / Karen, Sweazea (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The purpose of this thesis experiment was to design and create an Acoustically Active Cannula (AAC), which is furnished by a piezoelectric crystal placed at its tip that produces an acoustic navigation signal. I tested the functionality of the cannula in vitro and demonstrated its navigational abilities in vivo in anesthetized pigs. This experiment was based upon ultrasound science and technology, and thus some practical experience with conventional (B-mode) and Doppler ultrasound was achieved as well. The results of bench and experimental animal studies indicated proper functionality of the AAC for identification and spatial navigation of its tip with color Doppler ultrasound imaging.
ContributorsShamsa, Kayvan (Author) / Tyler, William (Thesis director) / Belohlavek, Marek (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The academic study of eSports, or professional competition through the medium of video games, has tended to focus on players' motivations to play and watch eSports as well as marketing concerns of huge eSports corporations. Instead of utilizing marketing or psychology to analyze this phenomenon, I investigate three areas of focus in accordance with available literature: the fans and their characteristics, the design of the game itself, and the relationship between fans and the game's developer. This investigation was conducted by first examining existing literature surrounding eSports fans, then collecting public domain data such as Reddit posts, forum posts, and YouTube videos, and last by studying interviews with developers and players. With this thesis, I apply a fan studies approach to eSports by creating a series of indicators based in each of the three focus areas which can be utilized as a systematic method of evaluating an eSport's popularity and growth.
ContributorsHilliker, Noah Henry (Author) / Ingram-Waters, Mary (Thesis director) / Schmidt, Peter (Committee member) / Anderson, Sky (Committee member) / School of Molecular Sciences (Contributor) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05