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Elucidating the Genetic Regulation of Zebrafish Type Ii Collagen Alpha 1 B
No full textType II collagens (Col2) are essential proteins providing flexibility and structure to vertebrate animals. During development type II collagens play a vital role in the formation of many structures, such as the cartilage of the skeleton, the notochord, the retina and many other tissues. Conserved throughout vertebrates, cartilage is composed of two main cell types: chondrocytes, which make up the bulk of the structure, and perichondral cells, which form the epithelial layer that surrounds chondrocytes and is essential for bone growth and joint protection. While much is known about the expression and regulation of type II collagens in chondrocytes, specifically the regulation and secretion of type II collagen Alpha-1 (Col2a1), little is known about the genetic regulation and expression of Col2a1 in the perichondrium. This study used the experimental benefits of the vertebrate Danio rerio, the common zebrafish, to explore the genetic regulation and expression of the zebrafish Col2a1 ohnolog in the perichondrium. Specifically, we focus on the zebrafish gene col2a1b, one of two zebrafish paralogs of human COL2A1gene, which we have previously found to be only expressed in the perichondrium and is not expressed in the chondrocytes of cartilage structures in fish. To study this gene, I first had to complete genome sequencing around this locus. In this study, bioinformatic and comparative genomic analyses have been used to finish genomic sequence gaps that are absent in the published zebrafish genome near the telomeric end of chromosome 11, where col2a1b resides. We have identified evolutionarily conserved, putative transcription factor regulatory elements near the col2a1b first exon using tools DCODE.org from NCBI and the JASPAR transcription factor binding site database. The generation and imaging of transgenic fish constructed using reporter plasmids including putative regulatory elements has shown expression patterns that support the hypothesis that these are conserved regulatory elements, and that col2a1a and col2a1b have functions shared with their COL2A1 orthologous gene from other species. Overall, these findings provide evidence that the zebrafish paralogs col2a1a and col2a1b share similar genetic regulation and that understanding these mechanisms may provide insight into the development of therapeutic strategies for diseases and disorders involving human COL2A1
Adolescent Social Media Use and Complete Mental Health: Examining the Intersections of Identity, Social-Emotional Skills, and Social Support
No full textSocial media and technology use have become ubiquitous for today’s adolescents. With the rise in technology use, mental health disorder diagnoses have also increased. Despite the increase in concern for both adolescent social media use and mental health, many schools, parents, and youth service clinicians do not have the knowledge or resources to intervene effectively. The current study explores two research questions. The first is to evaluate the moderating effect of social-emotional skills and social support on the relationship between social media use and mental health through structural equation modeling (SEM). The second research question is to explore whether this relationship differs across intersecting gender and racial identities, using a multiple-group SEM approach. This study is a secondary data analysis of a project completed at the University of Wisconsin-Madison. Deidentified data were obtained through the Technology and Adolescent Mental Wellness (TAM) data consortium and deemed exempt from Human Subjects Research. Latent variables included social media use, social-emotional skills, social support, and mental health. In total, there were 4,592 participants, with mean age of 14.6 years (SD = 1.7), and 52.1% were male and 66.9% were white. The full sample SEM model included statistically significant main effects (social media β = -.06, social-emotional skills β = .34, and social support β = .69). Further, social-emotional skills moderated the negative impact of social media on mental health (β = -.16), and social support also moderated the relationship between social media and mental health (β = -.08). There was a complimenting interaction where social support moderated the positive impact of social- emotional skills on mental health (β = .07). This model explained 76.6% of the variance, which illustrated a strong model fit. Participants were divided into four groups based on their gender and race for the multiple-group analysis: (1) white male, (2) white female, (3) non-white male, and (4) non-white female. The first step in the multiple-group analysis was to analyze the SEM from the first research question across all four groups. Results indicated that social support was not a significant moderator between social media use and mental health for any of the groups, and therefore, it was removed from the final multi-group comparison. In the final compared model, the main effect of social media use on mental health was not significant for any group, but social-emotional skills and social support demonstrated significant main effects on mental health for all groups. Social-emotional skills moderated the negative impact of social media on mental health for all groups. Social support only moderated the relationship between social-emotional skills and mental health for the white male group. This model explained 86.0% of the variance in the non-white female group, 82.5% in the white female group, 81.7% in the non-white male group, and 81.1% in the white male group, illustrating strong model fit for all groups. Overall, this study found that both social-emotional skills and social support were significant moderators to decrease the negative relationship between social media and mental health. When this relationship was tested across race/ethnicity and gender groups, social-emotional skills were a universal protective factor, but the impact of social support as a moderator between social-emotional skills and mental health was only significant for the white male group. Findings highlight the critical role social-emotional skills and social support can play in decreasing the negative impact of social media use on mental health, which should be taken into consideration when creating school-based interventions
Structure, Function, and Therapeutic Potential of PLP-Dependent Macromolecules: Case Studies on Bacillus subtilis GabR and Human GABA Aminotransferase
No full textPyridoxal-5\u27-phosphate (PLP) is a versatile and evolutionarily conserved cofactor central to a wide array of metabolic processes, including amino acid metabolism, neurotransmitter regulation, and gene expression. This dissertation explores the diverse biochemical and structural roles of PLP across bacterial and human systems, providing insights into transcriptional regulation, enzymatic catalysis, and therapeutic targeting. The first portion of this work investigates the Bacillus subtilis (B. subtilis) GabR (bsGabR) protein, a GntR-type transcription factor that uniquely employs PLP to sense and respond to γ-aminobutyric acid (GABA) via an aminotransferase-like domain. X-ray crystallographic and spectroscopic analyses of Tyr281 mutants (Y281F, Y281L, Y281A) reveal how specific structural features suppress full transaminase activity, preserving GabR’s function as a signal-dependent transcriptional regulator. Further studies explore GabR’s potential as an antimicrobial target, leveraging its bacterial exclusivity. A synthetic PLP analog, pyridoxal-5\u27-tetrazole (PLT), and a GABA derivative (4-phenoxymethyl-GABA) were structurally characterized in complex with bsGabR, uncovering a stable external aldimine and introducing novel scaffolds for antibiotic development. The final section shifts focus to the Human GABA aminotransferase (hGABA-AT), a PLP-dependent enzyme critical in GABA metabolism. This work presents the first high-resolution structures of hGABA-AT in multiple mechanistic states, including its inactivation by the anticonvulsant OV329. These findings illuminate key catalytic features, such as the arginine switch mechanism, and support structure-based design of therapeutics for neurological disorders. Together, this dissertation underscores the biochemical versatility of PLP and its potential in modulating enzyme activity and guiding structure-informed drug discovery
How School Psychologists Narrow the Socioeconomic Opportunity Gap: the Practices and Beliefs of School Psychologists in High-Performing, High-Poverty Schools
No full textThe purpose of this study is to examine the practices and beliefs of school psychologists working in high-performing, high-poverty (HP/HP) schools in order to make recommendations for how their practices can be replicated in other high-poverty schools to help narrow the socioeconomic opportunity gap. Results indicate that school psychologists engage in the major professional activities of school psychology practice to a similar degree as is documented in the existing literature. Despite relatively lower levels of engagement in delivering mental and behavioral health services, school psychologists view the practice to be highly impactful on students’ academic achievement. The school-wide activities commonly found in HP/HP schools that school psychologists are most involved in are those that help to understand poverty and hold students to high-expectations, and targeting supports for low-performing students. There is a significant, positive relationship between how much school psychologists engage in 12 out of the 22 activities examined and how impactful they perceive the activity is on students’ academic achievement. When asked to describe the perceived impact of their work and factors that influence students’ success, school psychologists often spoke about meeting students’ needs, administrators and staff, school culture, climate, and relationships, and special education. Examination of employment and school context variables found that school psychologists in HP/HP schools had similar ratios, slightly more years of experience, slightly lower degree attainment, come from more rural communities, and engage in fewer social justice activities compared to the most recent NASP Membership Survey (Farmer et al., 2021; Goforth et al., 2021). Implications for practice are discussed
Philosophical Purification as Liberation and Transformation
No full textThis study utilizes Plato’s conception of purification as a diagnostic tool to examine contemporary issues of police brutality and political violence. Within this context, I aim to treat the multiple tensions that arise with the question of living a good life. What does it mean to live and what does it mean to live a good life within constraints that magnify fear, anxiety, and despair? I argue that philosophical purification involves ‘aporia’ (perplexity; difficulty; confusion; loss; or puzzlement) in both a literal and generative sense. Moreover, the multiple aporias that arise cannot be reconciled by merely performing a religious rite of purification or providing an argument about how one should live, die, or commune with the divine. Consequently, I leverage the Greek term ‘aporia’ to illustrate that philosophical purification is an ongoing and edifying practice rather than a closed process that terminates in purity or wisdom. My interpretation of Plato’s conception of purification departs from traditional readings in five ways. First, I argue that one must shift their orientation towards an affirmation of life rather than a sanitized view of living. Second, purification involves an attempt to remove that which impedes progress towards self-improvement, not a complete uprooting of fear, shame, or ignorance. Third, the practice incorporates a striving to attain that which cannot fully be realized. Fourth, the striving is sustained by critical hope, collective agency, and collective discourse. Lastly, philosophical purification is liberatory and transformative in scope
Pyruvate Dehydrogenase Kinase 4 Mediates Sex Specific Outcomes in Sepsis Induced Cardiomyopathy
Get PDFDuring sepsis, males often experience worse cardiac outcomes than females. Here, we identified pyruvate dehydrogenase kinase 4 (PDK4) as a key contributor to this disparity. PDK4 is a mitochondrial protein that regulates glucose utilization by inhibiting pyruvate dehydrogenase (PDH). Using a mouse model of endotoxemia, we induced acute inflammation with a sublethal dose of lipopolysaccharide (LPS), which caused cardiac dysfunction and significantly increased myocardial PDK4 expression in males but not females. Cardiac-specific PDK4 overexpression promoted LPS-induced cardiac dysfunction in both sexes, whereas cardiac-specific PDK4 knockout provided protection. In wild-type males, LPS disrupted cardiac metabolism by decreasing PDH activity and fatty acid oxidation (FAO) while increasing lactate levels, suggesting a shift from oxidative phosphorylation toward glycolysis. These responses were exacerbated by PDK4 overexpression but attenuated by PDK4 knockout. Conversely, in female hearts, LPS minimally affected these metabolic parameters, except for a reduction in FAO with transgenic PDK4 overexpression. Moreover, PDK4 overexpression exacerbated LPS-induced cardiac mitochondrial damage in both sexes, characterized by disrupted cristae, impaired membrane potential, increased fragmentation and reduced mitophagy. Mitochondrial damage was accompanied by increased oxidative stress and inflammation in the myocardium. PDK4 knockout prevented these detrimental effects. Collectively, these findings suggest that PDK4 drives sex-specific cardiac responses in sepsis
Anthropogenic Litter in Freshwater Ecosystems: Effect on Ecosystem Processes and Spatial Distribution
Get PDFThe rapid increase of plastic production and disposal into the environment has resulted in anthropogenic litter (i.e., trash; AL) becoming a global problem. In aquatic ecosystems, macro- and microplastics are long-lived, mobile, and interact with the physical and chemical components of aquatic ecosystems. Our objectives were to: (1) assess the impact of microplastic pollution on the ecosystem processes of ecosystem metabolism and N2 flux in an oligotrophic lake and (2) to assess the abundance and assemblage of anthropogenic litter in a large urban river. For objective (1), we added microplastics at a range of concentrations to littoral mesocosms. Ecosystem metabolism rates were low, as expected for an oligotrophic lake, and showed no difference across microplastic treatments. N2 flux was also not affected by microplastic concentrations, with N2 being at saturation in the mesocosms. Our results suggested a minimal impact of microplastic on these ecosystem processes in an oligotrophic lake. For objective (2), volunteers collected litter along marked reaches signifying different habitats of an urban river over the course of three summers. The abundance and assemblage of AL was calculated and compared to scientist generated data from a similar site with similar habitats. Our results from both scientist and volunteer collected data showed that more complex habitats retained more trash and that the most common items found were plastic, including food-related items and fragments. This study provides insights on the ecological impacts of plastic pollution in urban rivers and on ecosystem-scale processes through in situ microplastic addition
The Mechanisms of Heterogenic Necrotic and Apoptotic Cell Death Fates in Human Epidermal Keratinocytes Following UVB Exposure
No full textUVB radiation is a carcinogen that triggers inflammation and contributes to skin carcinogenesis. Although UVB exposure can induce apoptosis, this form of cell death is non-inflammatory and thus cannot explain the inflammatory response observed following UVB. Necrotic regulated cell death (RCD) pathways, namely necroptosis, pyroptosis, and PANoptosis, are inherently pro-inflammatory, and thus this study focused on characterizing these in irradiated human epidermal keratinocytes. Keratinocytes were irradiated, treated with cell death inhibitors, and analyzed for apoptotic and necrotic RCD markers using immunofluorescence (IF). Despite uniform UVB exposure, keratinocytes displayed heterogeneous cell death responses, and these findings were validated in ex vivo human skin explants. Clonal analysis of keratinocytes from the HaCaT cell line revealed that clonal populations varied in their cell death fates, indicating that inflammatory cell death is not a random process, but is guided by intrinsic cellular factors unique to each clone. CRISPR-Cas9 gene editing generated MLKL knockouts verified with IF, western blot, and cell viability assays and found that cells are capable to switch inflammatory cell death pathways upon UVB exposure when necroptosis was inhibited. Co-localization and fluorescence intensity quantification demonstrated overlapping activation of apoptotic and necrotic pathways, including mixed PANoptotic phenotypes. Together, these findings support a model in which UVB-induced keratinocyte death is governed by a balance between immunologically silent and pro-inflammatory mechanisms. This research identifies insights into UVB-induced RCD heterogeneity and potential therapeutic targets for skin cancer chemoprevention
Low Code/No Code Meets the Metaverse
No full textSome maintain the metaverse is everywhere, and we are already deeply immersed, as it continues to excite the senses via the growing integration of avatars, holograms, shared virtual experience, and extended reality. At the same time, the field of low code/no code is blossoming. This article examines how these two fields, both fueled by generative artificial intelligence, are coevolving
Like Teacher, Like Student: An Exploration of Racial Matching on Black Student Identity Development in Secondary Education
Get PDFResearch on racially matching teachers of color with students of color has demonstrated a plethora of benefits, whether it is in West-Indian teachers with West-Indian students (Warikoo, 2004), Mexicana educators with Mexicana students (Sosa-Provencio, 2019), or Black students with Black teachers (Brooms, 2017). Black teachers are warrior spirits, acknowledging education as a “racial, cultural, linguistic, and spiritual reclamation” for Black students (Sosa-Provencio, 2018). In this study, I sought to understand how the racial matching between Black teachers and Black students can impact Black students’ identity and achievement. Numerous studies say racial matching helps students, but only a few focus on how. By focusing on Black students and their voices—which are often invisible in literature—we can better understand how Black teachers impact Black students’ identity instead of stopping at the mere fact that there is an impact. Based on the analysis of teacher interviews, student interviews, and the Worrell racial identity scale, findings revealed that Black teachers and Black students overlap in what they believe the role of the Black teacher is in their racial identity development. Black teachers and Black students articulated Black teachers as nurturers through affirming Black identity and providing family/kinship. However, Black teachers differed from Black students in highlighting two key findings: Black students inform Black teachers’ racial identity development just as much as Black teachers inform Black students’ racial identity development (reciprocity), and Black teachers spoke on the negative consequences of racial matching, seen through: a heavy emotional toll, disappointment in the Black community, anti-Blackness, and toxicity towards Black students. Black students also mentioned the emotional and physical harm that occur when racial matching is present without love. These findings suggest that racial matching is not enough for positive racial identity development; the racial matching must be coupled with love and care