Structural-Functional Studies on PSI-IsiA Super-complex in Synechocystis sp. PCC 6803

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Description
The thylakoid membranes of oxygenic photosynthetic organisms contain four large membrane complexes vital for photosynthesis: photosystem II and photosystem I (PSII and PSI, respectively), the cytochrome b6f complex and ATP synthase. Two of these complexes, PSII and PSI, utilize solar

The thylakoid membranes of oxygenic photosynthetic organisms contain four large membrane complexes vital for photosynthesis: photosystem II and photosystem I (PSII and PSI, respectively), the cytochrome b6f complex and ATP synthase. Two of these complexes, PSII and PSI, utilize solar energy to carry out the primary reaction of photosynthesis, light induced charge separation. In vivo, both photosystems associate with multiple antennae to increase their light absorption cross section. The antennae, Iron Stress Induced A (IsiA), is expressed in cyanobacteria as part of general stress response and forms a ring system around PSI. IsiA is a member of a large and relatively unexplored antennae family prevalent in cyanobacteria. The structure of the PSI-IsiA super-complex from the cyanobacteria Synechocystis sp. PCC 6803 was resolved to high resolution, revealing how IsiA interacts with PSI as well as the chlorophyll organization within this antennae system. Despite these structural insights, the basis for the binding between 18 IsiA subits and PSI is not fully resolved. Several IsiA mutants were constructed using insights from the atomic structure of PSI-IsiA, revealing the role of the C-terminus of IsiA in its interaction with PSI.
Date Created
2024
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Ethics and the Social Entrepreneur: The Journey to an Apposite Professional Code of Ethics

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Description
Social entrepreneurship has evolved into a global trend to promote responsible community development and social equity, including nonprofit, for-profit, or hybrid ventures that identify and exploit opportunities to promote social value and community benefit. Social entrepreneurship can be a powerful

Social entrepreneurship has evolved into a global trend to promote responsible community development and social equity, including nonprofit, for-profit, or hybrid ventures that identify and exploit opportunities to promote social value and community benefit. Social entrepreneurship can be a powerful tool that shifts economic and sustainable development foci from a financial growth paradigm to a community development and community determination paradigm, promoting social justice and resource distribution equity. When considering intercession's potentiality and impact on local communities, an investigation of the role of ethics in the social entrepreneurial profession is essential. It is essential to question the assumption that social can equal ethical and investigate the possibility that the outcome of an enterprise overrides negative impacts on the stakeholders, leading to potential saviorism, colonization, and even corruption in social entrepreneurial efforts. The purpose of this study is to draw on theories of ethics to inform decision-making processes in professional social entrepreneurship. The single-case study seeks to define the ethical considerations of social entrepreneurs and what factors weigh into ventures designed to advance social equity and promote economic equilibrium for marginalized populations. Additionally, it investigates the ethical parameters by which social entrepreneurs operate and how their decision-making prioritizes community stakeholders. The research builds on the work of established critical theorists, existing professional nonprofit and entrepreneurial codes of ethics, and incorporates culturally ethical research models to propose a conceptual framework for social entrepreneurship ethics. The proposed conceptual framework aims to guide social entrepreneurs in navigating the complex interplay of ethical dilemmas, power dynamics, and cultural contexts they encounter. By synthesizing traditional ethical models, critical theory considerations, and a culturally responsive, reflexive, and relationship-based model, this framework seeks to provide a robust, adaptable approach to ethical decision-making grounded in social justice, equity, and respect for diverse cultural norms. These results have implications for entrepreneurship education and social entrepreneurship education, as well as for establishing a culturally responsive, relational, and reflexive professional code of ethics for social entrepreneurs.
Date Created
2024
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Exploring the Interplay of Prosody, Language Skills, and Brain Connectivity: A Stroke Resting State fMRI Study

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Description
This thesis explores the interplay of aphasia symptoms and brain connectivityusing resting-state functional Magnetic Resonance Imaging (MRI). The research presented here is a step towards understanding the neural basis of linguistic prosody in particular, and its relationship with language impairments

This thesis explores the interplay of aphasia symptoms and brain connectivityusing resting-state functional Magnetic Resonance Imaging (MRI). The research presented here is a step towards understanding the neural basis of linguistic prosody in particular, and its relationship with language impairments in post-stroke aphasia. This study focuses on examining the functional connectivities of the frontal-parietal control network and the dorsal attention networks with specific regions within traditional language networks, as a growing body of research suggests that prosodic cues in speech may recruit control and attention networks to support language processing. Using resting- state fMRI, the present study examined the functional connectivity of the frontal parietal control and dorsal attention networks with traditional language regions in 28 participants who have experienced a stroke-related language impairment (i.e. aphasia) and 32 matched neurotypical adults. Overall, the study reveals significant functional connectivity differences of the frontoparietal control and dorsal attention networks between the stroke and control groups, indicating that individuals with aphasia have brain connectivity differences beyond the traditional language networks. Multiple regression analyses were then used to determine if functional connectivities of the frontoparietal control and dorsal attention networks within themselves and with traditional language regions could predict aphasia symptoms, as measured by the Western Aphasia Battery (WAB). Overall, the regression results indicate that greater functional connectivity between the frontoparietal control and dorsal attention networks with traditional language regions is associated with improved language abilities, with different connectivities predicting different types of aphasia symptoms (e.g. speech, naming / word finding, auditory comprehension, overall impairment). Altogether this study contributes to the understanding of the neural bases of language impairments post-stroke, highlighting the intricate connections between language and other cognitive networks, which may be mediated by prosody.
Date Created
2024
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Tensions in Decolonizing International School Educators: A Case Study

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Description
Each year, the existing cohort of elementary teachers at The American School participate in a professional development program. This program includes both academic and social adaptation resources and support for teachers within the school community. Previous to this research study,

Each year, the existing cohort of elementary teachers at The American School participate in a professional development program. This program includes both academic and social adaptation resources and support for teachers within the school community. Previous to this research study, the program mostly included training on academic programs, assessment strategies that align with the policies and resources for teachers to explore to support their curriculum. Most teachers requested training on the standards and assessment practices as the school made strategic shifts toward new pedagogical practices. Glaringly absent from this training was any support with the cultural transition for teachers, most of whom have not worked within a Mexican school setting with a largely Mexican family demographic. This action research study draws from theories of decolonization, postcolonialism, culturally relevant pedagogy, cultural mindset and critical whiteness studies. This case study took place during the second semester of the 2022-2023 school year at The American School, in Torreón, Mexico. Four international elementary teachers were randomly selected to participate in the study and agreed to engage in all elements of the data collection over the course of two months. Data collection included teacher classroom observations, multiple collective biography sessions, a focus group and individual interviews. The results from this study demonstrated that a colonial mindset heavily influenced teachers' decisions and beliefs about their work, sense of power within the classroom and how they interact with their students. Additionally, the research suggests that there was a dominant teacher-centered approach to pedagogical practices, and this reinforced traditional and Eurocentric values. Finally, an analysis of teacher emotions suggested elements of both white fragility and white fatigue centered around conversations of race, culture and oppression. The conclusion of this study includes a discussion of recommendations for future training, with the hopes of the patterns demonstrated in the cases studied.
Date Created
2024
Agent

Normative Consent and Epistemic Conceptions of Democracy

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Description
This work has two major goals. The first is to reframe the problem of political authority from its Conservative framing to a Reformist framing. This change creates a new benchmark for the success of a theory. Rather than justifying a

This work has two major goals. The first is to reframe the problem of political authority from its Conservative framing to a Reformist framing. This change creates a new benchmark for the success of a theory. Rather than justifying a pre-existing intuition, a theory can be successful if it could establish political authority whenever the state itself or an individual’s relationship to it changes. This change also shifts the focus from the state’s right to rule to moral housekeeping. In other words, the main goal is not to see when the state can use coercion against its citizens but rather to determine what political obligations citizens could have under different scenarios so that citizens can more accurately keep track of their moral reasons for action. The second major goal is to call into question epistemic theories of democratic authority through a critical examination of David Estlund’s theory of normative consent. Normative consent cannot establish political authority. Even granting that it could, normative consent would bind individuals to epistemic procedures rather than democratic procedures given that epistemic procedures better solve the moral problems that generate normative consent. However, this then raises worries from the public reason perspective that epistemic procedures would impose a procedure on some citizens which they could reject from a qualified position. To overcome this worry, it is shown that epistemic procedures based on reducing the power of the ignorant rather than raising the power of the experts are not open to such qualified rejection, and democratic procedures in the real world will do no better than a coin flip at selecting correct policies. In the end, one branch of epistemic conceptions of democratic authority are proven untenable.
Date Created
2024
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Supporting Pre-Service Teachers Through Intersectionally Conscious Collaboration: A Multimethod Study Utilizing Transformative Learning Theory

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Description
K-12 educators in the U.S. are woefully unprepared to meaningfully engage with students and their families from multiply marginalized communities. In addition, current educational research and praxis continue to perpetuate prescriptive notions of family involvement and engagement that center white,

K-12 educators in the U.S. are woefully unprepared to meaningfully engage with students and their families from multiply marginalized communities. In addition, current educational research and praxis continue to perpetuate prescriptive notions of family involvement and engagement that center white, middle-class practices and marginalize students and families with markers of difference. To create and sustain the conditions needed to disrupt educational inequities, K–12 educators must deeply understand their own intersecting sociocultural identities, those of other educators, as well as of their students to create effective environments for learners across all markers of diversity and to foster equitable engagement practices with families and students. This dissertation research aims to address these inequities through teacher education using an intersectional conscious collaboration protocol for educator preparation (ICC-EP) and researcher-developed teaching modules as an instructional tool with pre-service teachers (PSTs). The ICC Protocol and associated modules are grounded in intersectional competence and the Black feminist framework of intersectionality coupled with collaboration and coteaching. This research examines how the ICC-EP and learning modules shaped PSTs’ intersectional competence, supported collaborative inclusive and special educational practices, and enhanced the potential to equitably engage multiply marginalized families. This multimethod case study utilizes ICC-EP modules, assignments, teacher education course material, and surveys as data throughout a semester-long university course centered on family engagement. Using an iterative coding process, the researcher employed Mezirow’s 10-phase transformative learning theory throughout the deductive coding process alongside thematic analyses to understand PSTs’ course experiences. In addition, quantitative transformative learning survey data is used to further understand the extent of PSTs’ views of transformative learning processes and outcomes. Research findings indicated that the ICC-EP assignments, learning modules, and course material strengthened the development of PSTs’ intersectional competence and shaped their teaching practices and approaches. Data analyses also demonstrated PSTs’ beliefs and practices regarding family engagement were transformed beyond prescriptive notions of parent involvement that further extended family-school partnerships and considerations of differing sociocultural identities and practices. These findings indicate the need for continued teacher education curriculum that is grounded in intersectionality and guided by research-based tools to adequately prepare PSTs to address systemic inequities.
Date Created
2024
Agent

Microplastics in the Desert Southwest: Occurrence and Characterization In Atmospheric, Aquatic, and Terrestrial Environments

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Description
Microplastics, plastics smaller than 5 mm, are an emerging concern worldwide due to their potential adverse effects on the environment and human health. Microplastics have the potential to biomagnify through the food chain, and are prone to adsorbing organic pollutants

Microplastics, plastics smaller than 5 mm, are an emerging concern worldwide due to their potential adverse effects on the environment and human health. Microplastics have the potential to biomagnify through the food chain, and are prone to adsorbing organic pollutants and heavy metals. Therefore, there is an urgent need to assess the extent of microplastic contamination in different environments. The occurrence of microplastics in the atmosphere of Tempe, AZ was investigated and results show concentrations as high as 1.1 microplastics/m3. The most abundant identified polymer was polyvinyl chloride. However, chemical characterization is fraught with challenges, with a majority of microplastics remaining chemically unidentified. Laboratory experiments simulating weathering of microplastics revealed that Raman spectra of microplastics change over time due to weathering processes. This work also studied the spatial variation of microplastics in soil in Phoenix and the surrounding areas of the Sonoran Desert, and microplastic abundances ranged from 122 to 1299 microplastics/kg with no clear trends between different locations, and substantial total deposition of microplastics occurring in the same location with resuspension and redistribution of deposited microplastics likely contributing to unclear spatial trends. Temporal variation of soil microplastics from 2005 to 2015 show a systematic increase in the abundance of microplastics. Polyethylene was prominent in all soil samples. Further, recreational surface waters were investigated as a potential source of microplastics in aquatic environments. The temporal variation of microplastics in the Salt River, AZ over the course of one day depicted an increase of 8 times in microplastic concentration at peak activity time of 16:00 hr compared to 8:00 hr. Concurrently, microplastic concentrations in surface water samples from apartment community swimming pools in Tempe, AZ depicted substantial variability with concentrations as high as 254,574 MPs/m3. Polyester and Polyamide fibers were prevalent in surface water samples, indicating a release from synthetic fabrics. Finally, a method for distinguishing tire wear microplastics from soot in ambient aerosol samples was developed using Programmed Thermal Analysis, that allows for the quantification of Elemental Carbon. The method was successfully applied on urban aerosol samples with results depicting substantial fractions of tire wear in urban atmospheric environments.
Date Created
2024
Agent

Student Ambassadors: Creating a Venue for Middle School Students to Share their Voices to Improve their Social Emotional Competencies

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Description
The researcher explored the impact of a student voice initiative (SVI), the Student Ambassador Council (SAC), on the social-emotional competencies (SECs) of middle school, 5th- 8th grades students. Drawing upon the principles of youth empowerment, more specifically Youth Participatory Action

The researcher explored the impact of a student voice initiative (SVI), the Student Ambassador Council (SAC), on the social-emotional competencies (SECs) of middle school, 5th- 8th grades students. Drawing upon the principles of youth empowerment, more specifically Youth Participatory Action Research (YPAR), and social-emotional learning (SEL), the SAC provided a platform for students to actively participate in decision-making processes within their school community. The researcher employed action research using a mixed methodologies approach, combining surveys, interviews, and participant observations to gather data on students' experiences and perceptions of the SAC. Quantitative analysis of pre- and post-surveys did not reveal significant improvements in students' SECs following their participation in the SAC. However, qualitative data from open-ended questions on the post-survey, interviews and observation provided further clarity demonstrating the initiative fosters growth in students’ perceptions of Student Voice, Social Awareness and Self-Efficacy in addition to student development in confidence, self-directed learning and civic engagement. Moreover, the study also suggested broader implications of the SAC on school climate and administrative practices. Findings suggested that SVIs like the SAC contributed to a more positive and inclusive school environment, promoting greater collaboration between students and school staff.
Date Created
2024
Agent

Metagenomics Approaches in Advancing Microbiome Research

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Description
Metagenomics is the study of the structure and function of microbial communities through the application of the whole-genome shotgun (WGS) sequencing method. Providing high-resolution community profiles at species or even strain levels, metagenomics points to a new direction for microbiome

Metagenomics is the study of the structure and function of microbial communities through the application of the whole-genome shotgun (WGS) sequencing method. Providing high-resolution community profiles at species or even strain levels, metagenomics points to a new direction for microbiome research in understanding microbial gene function, microbial-microbial interactions, and host-microbe interactions. My thesis work includes innovation in metagenomic research through the application of ChatGPT in assisting beginning researchers, adopt pre-existed alpha diversity metric for metagenomic data to improve diversity calculation, and the application of metagenomic data in Alzheimer’s disease research.Since the release of ChatGPT in March 2023, the conversation regarding AI in research has promptly been debated. Through the prompted bioinformatic case study, I demonstrate the application of ChatGPT in conducting metagenomic analysis. I constructed and tested a working pipeline aimed at instructing GPT in completing shotgun metagenomic research. The pipeline includes instructions for various essential analytic steps: quality controls, host filtering, read classification, abundance estimation, diversity calculation, and data visualization. The pipeline demonstrated successful completion and reproducible results. Alpha diversity measurement is critical to understanding microbiomes. The widely used Faith’s phylogenetic diversity (PD) metric is agnostic of feature abundance and, therefore, falls short of analyzing metagenomic data. BWPDθ, an abundance weighted variant of Faith’s PD, was implemented in scikit-bio alpha diversity metrics. My analysis shows that BWPDθ does have better performance compared to Faith’s PD, revealing more biological significance, and maintaining their robustness at a lower sampling depth. The progression of Alzheimer’s disease (AD) is known to be associated with alterations in the patient’s gut microbiome. Utilizing metagenomic data from the AlzBiom study, I explored the differential abundance of bacterial pncA genes among healthy and AD participants by age group. The analysis showed that there was no significant difference in pncA abundance between the healthy and AD patients. However, when stratified by age group, within the age group 64 to 69, AD was shown to have significantly lower pncA abundance than the healthy control group. The Pearson's test showed a moderate positive association between age and pncA abundance.
Date Created
2024
Agent

The Effects of Parental Protective Factors and Internalized Nonbinary Negativity on Negative Mental Health Outcomes among Nonbinary Young Adults of Color

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Description
Despite the growing nonbinary population and their unique experiences, nonbinary people of color specific research remains scarce as most studies were done with predominantly white samples and failed to disaggregate transgender men and transgender women from nonbinary people. While parental

Despite the growing nonbinary population and their unique experiences, nonbinary people of color specific research remains scarce as most studies were done with predominantly white samples and failed to disaggregate transgender men and transgender women from nonbinary people. While parental acceptance and support (PAS) serve as protective factors for distal and proximal stressors-induced negative mental health outcomes among TNB youth, more research is needed to examine whether PAS play a role in nonbinary young adults of color’s mental health. Additionally, PAS may lead nonbinary young adults to internalize negative messages toward their gender identity, impacting mental health. This study aimed to examine whether PAS received by nonbinary young adults of color vary by race, whether PAS are associated with depression and suicidality, and whether these associations are mediated by internalized nonbinary negativity (INN) among nonbinary adults of color. Cross-sectional data from 174 nonbinary young adults of color were analyzed. Only parental support (PS) but not parental acceptance (PA) differed across racial groups. PAS were found to be negatively associated with depression and suicidality, but INN did not mediate the association between PS and negative mental health outcomes. Findings of this study reiterate the mental health disparities seen within the nonbinary community and serve as a call for attention to the effects of PAS in the lives of nonbinary young adults of color. Future research should inquire about the cultural values that influence PAS, ways to cultivate PAS among parents using existing cultural strengths, and the benefits of helping nonbinary young adults of color to maintain integral social support from parents.
Date Created
2024
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