A role for Dynamin-dependent endocytosis during Drosophila gastrulation

Gastrulation, a process conserved among many higher organisms, is the directed migration of cells into layers that will establish various tissues targeted to become anatomical structures. This process is accomplished through another conserved morphogenetic event, known as cell intercalation. Early in development, this movement of cells within an organized tissue leads to unique cellular arrangements where neighboring cells contract their shared interfaces in order to meet at a shared vertex. In this thesis, I present work that demonstrates a requirement for Dynamin-dependent endocytosis during these contraction events. Using quantitative analysis, I have identified varied cell behaviors during experiments which knockdown the function of dynamin. In addition, I demonstrate the existence of an antagonistic relationship between Dynamin and the Myosin II motor protein. Lastly, localization and functional studies I performed for this work suggest a role for Sorting Nexin proteins during plasma membrane reorganization required for Dynamin-dependent endocytosis.

The Impact of Transit Oriented Development on the Travel Behaviors of Workers in Denver, Colorado

To combat unsustainable transportation systems characterized by reliance on petroleum, polluting emissions, traffic congestion and suburban sprawl, planners encourage mixed use, densely populated areas that provide individuals with opportunities to live, work, eat and shop without necessarily having to drive private automobiles to accommodate their needs. Despite these attempts, the frequency and duration of automobile trips has consistently increased in the United States throughout past decades. While many studies have focused on how residential proximity to transit influences travel behavior, the effect of workplace location has largely been ignored. This paper asks, does working near a TOD influence the travel behaviors of workers differently than workers living near a TOD? We examine the non-work travel behaviors of workers based upon their commuting mode and proximity to TODs. The data came from a 2009 travel behavior survey by the Denver Regional Council of Governments, which contains 8,000 households, 16,000 individuals, and nearly 80,000 trips. We measure sustainable travel behaviors as reduced mileage, reduced number of trips, and increased use of non-automobile transportation. The results of this study indicate that closer proximity of both households and workplaces to TODs decrease levels of car commuting and that non-car commuting leads to more sustainable personal travel behaviors characterized by more trips made with alternative modes.

The Hybrid Spirit Animating Chinese Pentecostals in Malaysia

This dissertation interrogates the assertion in postcolonial scholarship, especially from the work of Homi Bhabha that the construction and performance of hybrid identities act as a form of resistance for marginalized communities against structures of oppression. While this study supports this assertion, it also critiques how hybridity fails to address issues of unequal power relations. This has led to an uncritical use of hybridity that reproduces the very idea of static identity which its proponents claim to transcend. Through qualitative study of Chinese members of a Pentecostal church in Malaysia, this study argues that church members engage in "unequal belonging" where they privilege certain elements of their identities over others. In concert with Pierre Bourdieu's conceptions of habitus, field, and capital, unequal belonging highlights how hybridity fails to capture the intersecting and competing loyalties, strategies, and complexities of identity formation on a contextual level. Unequal belonging challenges postcolonial scholars to locate the subtle workings of power and privilege that manifest even among marginalized communities. The study first situates the Chinese through an analysis of the historical legacy of British colonialism that has structured the country's current socio-political configuration along bounded categories of identification. The habitus constrains church members to accept certain Chinese ethnic markers as "givens." Although they face continuous marginalization, interviewee data demonstrates that church members negotiate their Chineseness and construct a "Modern Chinese" ethnic identity as a strategic move away from Chinese stereotypes. Moreover, conversion to Christianity affords church members access to cultural capital. Yet, it is limited and unequal capital. In particular, the "Chinese Chinese," who church members have demarcated as backward and traditional, are unable to gain access to this capital because they lack fluency in English and knowledge in modern, westernized worldviews. Unequal belonging nuances monolithic conceptions of hybridity. It demonstrates how church members' privilege of Christianity over Chineseness exposes the complex processes of power and privilege that makes westernized-English-speaking Chinese Christians culturally "higher" than non-English-speaking, non-Christian, Chinese. This study provides significant contribution to the complex aspect of hybridity where it is both a site of resistance and oppression.

Comparison of Reading Development Across Socioeconomic Status in the United States

It is well known that higher parental socioeconomic status (SES) predicts better child reading outcomes, but little work has been done to unpack this finding. The main overall question addressed by this project was whether cognitive models of the two main reading outcomes, single word reading (SWR) and reading comprehension (RC), performed similarly across levels of parental SES. The current study predicted a differential relation between parental SES and both predictors and outcomes because of the known large relation between parental SES and child oral language development. Three questions examined the mediating effects of cognitive predictors on the relation between parental SES and reading outcomes, the moderating effects of SES on the developmental trajectories of reading outcomes, and the strength of the relationship between SES and the two reading outcomes. Participants were part of two large and comprehensive datasets: the cross-sectional Colorado Learning Disability Research Center (CLDRC; n=1554) sample, and the International Longitudinal Twin Study (ILTS; n=463 twin pairs) sample. In terms of cognitive predictors, the relation between SES and SWR was disproportionately mediated by two language skills, vocabulary (VOC) and phonological awareness (PA). For the RC models, both SWR and oral listening comprehension (OLC) did not disproportionally mediate the relation between RC and SES; however, full mediation was not exhibited. With regard to the trajectory of reading outcomes, SES moderated the starting values of SWR and RC, and the slopes of SWR development. When performance on the control measures of early reading skills (e.g., print knowledge, vocabulary, and decoding skills) was included the models, the moderating effects of SES were completely accounted for by these measures. In terms of outcomes, SES had a stronger relation to RC than to SWR, especially at later ages. These findings have implications for interventions aimed at improving reading outcomes in children from lower SES families.

Applications of EPR with an Emphasis on Tau Fibril Structure

Substances containing unpaired electrons have been studied by electron paramagnetic resonance (EPR) for nearly 70 years. With continual development and enhancement of EPR techniques, questions have arisen regarding optimum method selection for a given sample based on its properties. In this work, radiation defects, natural lattice defects, solid organic radicals, radicals in solution, and spin-labeled proteins were analyzed using CW, pulse, and rapid scan EPR to compare methods. Studies of solid BDPA, EOe in quartz, Ns0 in diamond, and a-Si:H, showed that rapid scan could overcome many obstacles presented by other techniques, cementing rapid scan as an effective alternative to CW and pulse methods. Relaxation times of six nitroxide radicals were characterized from 0.25-34 GHz, guiding synthesis of improved nitroxides for in vivo imaging experiments. Processes contributing to T1 of DPPH in polystyrene were found through variable temperature measurements at X- and Q-band, resolving previously-reported discrepancies in relaxation properties and providing new insight into this commonly-used standard. In the history of EPR, the study of proteins is relatively new. Double electron-electron resonance (DEER) has emerged as a powerful technique for the study of amyloid fibrils, a class of protein aggregates implicated in a number of neurodegenerative disorders. Microtubule-associated protein tau forms fibrils linked to Alzheimerfs disease through seeded conversion of monomer. Self-assembly is mediated by the microtubule binding repeats in tau, and there are either three or four repeats present depending on the isoform. DEER was used to show that filaments of 3R and 4R tau are conformationally distinct and that 4R fibrils adopt a heterogeneous mixture of conformations. Populations of 4R fibril conformations, which were independently validated using a model system, can be modulated by introduction of mutations to the primary sequence or by varying fibril growth conditions. These findings provided unprecedented insights into the seed selection of tau monomers and established conformational compatibility as an important driving force in tau fibril propagation. Lastly, DEER acquisition was improved through addition of paramagnetic metal to spin-labeled protein, decreasing collection time, and through use of a novel spin label with increased T2, thereby lengthening the available acquisition window.

Activity-Regulated microRNAs: Modulators of Synaptic Growth at the Drosophila Neuromuscular Junction

It is well established that long-term changes in synaptic structure and function are mediated by rapid activity-dependent gene transcription and new protein synthesis. A growing body of evidence supports the involvement of the microRNA (miRNA) pathway in these processes. We have used the Drosophila neuromuscular junction (NMJ) as a model synapse to characterize activity-regulated miRNAs and their important mRNA targets. Here, we have identified five neuronal miRNAs (miRs-1, -8, -289, -314, and -958) that are significantly downregulated in response to neuronal activity. Furthermore we have discovered that neuronal misexpression of three of these miRNAs (miR-8, -289, and -958) is capable of suppressing new synaptic growth in response to activity suggesting that these miRNAs control the translation of biologically relevant target mRNAs. Putative targets of the activity-regulated miRNAs-8 and -289 are significantly enriched in clusters mapping to functional processes including axon development, pathfinding, and axon growth. We demonstrate that activity-regulated miR-8 regulates the 3'UTR of wingless, a presynaptic regulatory protein involved in the process of activity-dependent axon terminal growth. Additionally, we show that the 3'UTR of the protein tyrosine phosophatase leukocyte antengen related (lar), a protein required for axon guidance and synaptic growth, is regulated by activity-regulated miRNAs-8, -289, and -958 in vitro. Both wg and lar were identified as relevant putative targets for co-regulation based through our functional cluster analysis. One putative target of miR-289 is the Ca2+/calmodulin-dependent protein kinase II (CamKII). While CamKII is not predicted as a target for co-regulation by multiple activity-regulated miRNAs we identified it as an especially pertinent target for analysis in our system for two reasons. First, CamKII has an extremely well characterized role in postsynaptic plasticity, but its presynaptic role is less well characterized and bears further analysis. Second, local translation of CamKII mRNA is regulated in part by the miRNA pathway in an activity-dependent manner in dendrites. We find that the CamKII 3'UTR is regulated by miR-289 in-vitro and this regulation is alleviated by mutating the `seed region' of the miR-289 binding site within the CamKII 3'UTR. Furthermore, we demonstrate a requirement for local translation of CamKII in motoneurons in the process of activity-regulated axon terminal growth.

Covered in Dust: Coming of Age in a Gazebo Factory

This memoir chronicles the three summers I spent working in the factories at Chestnut Hill Gazebos. It focuses on three narrative strands: the day-to-day life of a factory worker, the struggles within and eventual breakdown of my relationship with my girlfriend, and how my job at Chestnut Hill helped me critique my fundamentalist Christian roots by forcing me into a deeper understanding of my faith and its relationship to the world outside the confines of my upbringing. The critical afterword uses essays by Leona Toker and other theorists as a framework for understanding how I approached several different problems when writing my memoir, such as how to present incomplete memories of events, whether or not to condense events for the sake of a more streamlined narrative, and whether or not a memoirist should use composite characters. I explain how various practitioners and critics influenced my decisions, and I also compare my approach to the practices of other memoirists.

The role of the social environment in non-suicidal self-injury among LGBTQ youth: A mixed methods study

Non-suicidal self-injury (NSSI), such as cutting and burning, is a widespread social problem among lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) youth. Extant research indicates that this population is more than twice as likely to engage in NSSI than heterosexual and cisgender (non-transgender) youth. Despite the scope of this social problem, it remains relatively unexamined in the literature. Research on other risk behaviors among LGBTQ youth indicates that experiencing homophobia and transphobia in key social contexts such as families, schools, and peer relationships contributes to health disparities among this group. Consequently, the aims of this study were to examine: (1) the relationship between LGBTQ youth's social environments and their NSSI behavior, and (2) whether/how specific aspects of the social environment contribute to an understanding of NSSI among LGBTQ youth. This study was conducted using an exploratory, sequential mixed methods design with two phases. The first phase of the study involved analysis of transcripts from interviews conducted with 44 LGBTQ youth recruited from a community-based organization. In this phase, five qualitative themes were identified: (1) Violence; (2) Misconceptions, Stigma, and Shame; (3) Negotiating LGBTQ Identity; (4) Invisibility and Isolation; and (5) Peer Relationships. Results from the qualitative phase were used to identify key variables and specify statistical models in the second, quantitative, phase of the study, using secondary data from a survey of 252 LGBTQ youth. The qualitative phase revealed how LGBTQ youth, themselves, described the role of the social environment in their NSSI behavior, while the quantitative phase was used to determine whether the qualitative findings could be used to predict engagement in NSSI among a larger sample of LGBTQ youth. The quantitative analyses found that certain social-environmental factors such as experiencing physical abuse at home, feeling unsafe at school, and greater openness about sexual orientation significantly predicted the likelihood of engaging in NSSI among LGBTQ youth. Furthermore, depression partially mediated the relationships between family physical abuse and NSSI and feeling unsafe at school and NSSI. The qualitative and quantitative results were compared in the interpretation phase to explore areas of convergence and incongruence. Overall, this study's findings indicate that social-environmental factors are salient to understanding NSSI among LGBTQ youth. The particular social contexts in which LGBTQ youth live significantly influence their engagement in this risk behavior. These findings can inform the development of culturally relevant NSSI interventions that address the social realities of LGBTQ youth's lives.

Parenting influences on depression: A moderated mediated model

Little is known about the developmental processes through which parenting factors may influence clinical depression among youth. This study investigated whether parenting influences the onset of clinical depression through the mediating mechanism of negative attributional style, particularly under conditions of high stress, in a community sample of children and adolescents (N = 289). Results supported a moderated mediation model in which low levels of observed parent positive regard and sensitivity to distress during a youth stressor task were indirectly associated with an increased likelihood of experiencing an episode of depression over an18 month period, through the mediating influence of youth negative attributional style, but only for youth who also experienced a high number of peer stressors. These findings elucidate mechanisms through which parenting may contribute to risk for depression during the transition into and across adolescence.

The Pursuit of Balanced Income An Economic Perspective on Wealth

The purpose of this thesis is to determine if households with moderate incomes have the opportunity to acquire pecuniary wealth. In an environment of increasing globalization, labor-eliminating technology, and an overburdened entitlement system, the position of wealth is necessary for households with a penchant for early retirement and particularly for those that will inevitably succumb to involuntary retirement. In these writings, qualitative and quantitative descriptions of wealth are offered; two microeconomic metrics are introduced to identify baseline wealth and to gauge proximity to this value; and strategies are devised to close the gap between these metrics. The construct of the economic intertemporal household budget was used as the basis for this research whereby conventional measures of wealth, i.e. net worth and liquid net worth, have been coupled with historical and empirical household data to define and extrapolate wealth and wealth proximity metrics. The major finding is wealth is a dynamic variable contingent upon consumption level rather than income or saving levels. And because households exercise a greater degree of autonomy over consumption, moderate earners are afforded the same opportunities as high earners. The position of wealth is necessary because it sustains consumption in the event of an unwelcomed retirement and it can assuage reliance on entitlement programs. For the majority of households, wealth is a matter of choice.

Mental health literacy of Latina women in the United States for their school-aged children

Despite known mental health (MH) disparities faced by Latino children relative to children from other minority groups of similar socioeconomic status (SES), little is known about how Latina mothers make MH decisions for their children. The present study examined links between Latina mothers' mental health literacy (MHL), including the recognition of and response to child psychiatric symptoms, and maternal acculturation factors as well as interpersonal violence (IPV) related symptomatology. Participants were 80 Latina mothers from Denver, Colorado and Modesto, California with at least one child between the ages of 8-12 years. Mothers were presented vignettes depicting child internalizing and externalizing disorders as well as interviewed about their help seeking behaviors. Maternal acculturation was not related to identification of disorders, but was related to more symptoms recognized for child internalizing and externalizing symptoms. Acculturation predicted use of formal source of care for child internalizing and externalizing disorder. Women demonstrated a preference for informal source of care, with the exception of IPV-related child symptoms, where women demonstrated a preference for formal source of care. IPV-related symptoms did not moderate the relationship between acculturation and MHL. The relationship between maternal acculturation, IPV related symptomatology and their combined effect on MHL for child psychiatric disorders are discussed.

Towards the Consideration of the U.S. Community College Model to Address the Need for Higher Education Reforms in Ghana

ABSTRACT The higher education systems throughout the continent of Africa are undergoing unprecedented challenges and are considered in crisis. African countries, including Ghana, all have in common ties to their colonial legacy whereby they are confronted with weak policies put in place by their colonizers. Having gained their independence, Africans should now take responsibility for the task of reforming their higher education system. To date, nothing substantial has been accomplished, with serious implications for weakening and damaging the structures of the foundation of their educational systems. This qualitative, single case study utilized a postcolonial theory-critical pedagogy framework, providing guidance for coming to grips with the mindset posed by Ghana's colonial heritage in the postcolonial era, especially in terms of its damaging effects on Ghana's higher education system. The study explores alternative pathways for secondary school students to transition to tertiary education--a problematic transition that currently hinders open access to all and equality in educational opportunity, resulting in a tremendous pool of discontinued students. This transitional problem is directly related to Ghana's crisis in higher education with far reaching consequences. The alternative pathway considered in this study is an adaptation of the U.S. community college model or an integration of its applicable aspects into the current structures of the higher education system already in place. In-depth interviews were conducted with 5 Ghanaian professors teaching at community colleges in the United States, 5 Ghanaian professors teaching at universities in Ghana, and 2 educational consultants from the Ghanaian Ministry of Education. Based on their perspectives of the current state of Ghanaian higher education, analyzed in terms of pedagogy, structure/infrastructure, and curriculum, the participants provided their perceptions of salient aspects of the U.S. community college model that would be applicable to Ghana's situation, along with other recommendations. Access to all, including equality of educational opportunity, was considered essential, followed by adaptability, affordability, practicality, and quality of curriculum content and delivery. Canada's successful adaptation of the U.S. model was also discussed. Findings can help guide consideration of alternative pathways to higher education in Ghana and Africa as a whole.

Everything in di Dark Muss Come to Light: A Postcolonial Investigation of the Practice of Extra Lessons at the Secondary Level in Jamaica's Education System

Despite the vast research examining the evolution of Caribbean education systems, little is chronologically tied to the postcolonial theoretical perspectives of specific island-state systems, such as the Jamaican education system and its relationship with the underground shadow education system. This dissertation study sought to address the gaps in the literature by critically positioning postcolonial theories in education to examine the macro- and micro-level impacts of extra lessons on secondary education in Jamaica. The following postcolonial theoretical (PCT) tenets in education were contextualized from a review of the literature: (a) PCT in education uses colonial discourse analysis to critically deconstruct and decolonize imperialistic and colonial representations of knowledge throughout history; (b) PCT in education uses an anti-colonial discursive framework to re-position indigenous knowledge in schools, colleges, and universities to challenge hegemonic knowledge; (c) PCT in education involves the "unlearning" of dominant, normative ideologies, the use of self-reflexivity, and deconstruction; and (d) PCT in education calls for critical pedagogical approaches that reject the banking concept of education and introduces inclusive pedagogy to facilitate "the passage from naïve to critical transitivity" (Freire, 1973, p. 32). Specifically, using a transformative mixed-methods design, grounded and informed by a postcolonial theoretical lens, I quantitatively uncovered and then qualitatively highlighted how if at all extra lessons can improve educational outcomes for students at the secondary level in Jamaica. Accordingly, the quantitative data was used to test the hypotheses that the practice of extra lessons in schools is related to student academic achievement and the practice of critical-inclusive pedagogy in extra lessons is related to academic achievement. The two-level hierarchical linear model analysis revealed that hours spent in extra lessons, average household monthly income, and critical-inclusive pedagogical tents were the best predictors for academic achievement. Alternatively, the holistic multi-case study explored how extra-lessons produces increased academic achievement. The data revealed new ways of knowledge construction and critical pedagogical approaches to galvanize systemic change in secondary education. Furthermore, the data showed that extra lessons can improve educational outcomes for students at the secondary level if the conditions for learning are met. This study sets the stage for new forms of knowledge construction and implications for policy change.

Monetary Effervescence: A Sociological Theory of Religion Applied to Money

This project attempts to answer the question "What holds the construction of money together?" by asserting that it is money's religious nature which provides the moral compulsion for people to use, and continue to uphold, money as a socially constructed concept. This project is primarily descriptive and focuses on the religious nature of money by employing a sociological theory of religion in viewing money as a technical concept. This is an interdisciplinary work between religious studies, economics, and sociology and draws heavily from Emile Durkheim's 'The Elementary Forms of Religious Life' as well as work related to heterodox theories of money developed by Geoffrey Ingham, A. Mitchell Innes, and David Graeber. Two new concepts are developed: the idea of monetary sacrality and monetary effervescence, both of which serve to recharge the religious saliency of money. By developing the concept of monetary sacrality, this project shows how money acts to interpret our economic relations while also obfuscating complex power dynamics in society, making them seem naturally occurring and unchangeable. The project also shows how our contemporary fractional reserve banking system contributes to money's collective effervescence and serves to animate economic acting within a monetary network. The project concludes by outlining multiple implications for religious studies, economics, sociology, and central banking.

Development of the DORI-TBI: An Investigation to Develop a New Screening Measure to Determine Consultation with a School-Based Brain Injury Resource Team

Brain injury is the leading cause of disability and death in children in the United States. Student re-entry into the school setting following a traumatic brain injury is crucial to student success. Multidisciplinary teams within the school district comprised of individuals with expertise in brain injury are ideal in implementing student specific treatment plans given their specialized training and wide range of expertise addressing student needs. Therefore, the purpose of this study is to develop and initially validate a quantitative instrument that school personnel can use to determine if a student, identified as having a traumatic brain injury, will benefit from district-level consultation from a brain injury team. Three studies were designed to investigate the research questions. In study one, the planning and construction of the DORI-TBI was completed. Study two addressed the content validity of the DORI-TBI through a comparison analysis with other referral forms, content review with experts in the field of TBI, and cognitive interviews with professionals to test the usability of the new screening tool. In study three, a field administration was conducted using vignettes to measure construct validity. Results produced a valid and reliable new screening instrument that can aid school-based teams to more efficiently utilize district level consultation with a brain injury support team.