Search

As superintendents steer their districts through uncharted territories, their experiences and strategies are key to transforming schools. This study employed transcendental phenomenology to explore how seven Virginia superintendents from two different regions described their experiences implementing novel cultural competency training. Data collection involved a semistructured interview protocol comprising six interview questions recorded and transcribed via Zoom. An open coding process was organized with NVivo 14 software to analyze participants' transcripts. The findings pointed to six interconnected themes, making it evident that implementing cultural competency training in educational settings involves multifaceted challenges and nuanced strategies ranging from political tensions and community engagement to recognizing cultural significance in education. The themes highlighted how transformational leadership aligns with the efforts required for successful implementation. The study's findings carry implications for leadership, addressing disparities, continued professional learning, and customized communication. Future research recommendations encompass replication on a larger scale; quantitative studies measuring the impact of cultural competency training or differences in experiences related to race, gender, or location; a longitudinal exploration of changes and trends over time; and an investigation into the direct influence of superintendents' leadership styles on successful implementation of cultural competency. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

The oxygenated volatile organic compound, acetaldehyde, plays a fundamental role in atmospheric chemistry by altering the atmosphere's oxidative status or "self-cleaning capacity". Acetaldehyde flux from freshwater, estuarine, and marine environments is thought to be under significant microbial control, yet the identity and diversity of microbial acetaldehyde degraders, and the mechanisms of acetaldehyde degradation, are largely unknown. In this thesis, the key acetaldehyde-degrading microorganisms in the Colne Estuary, the River Colne and the River Gipping were identified using metagenetic sequencing and quantitative PCR. Bacteria were primarily responsible for acetaldehyde degradation, with members of the genera Pseudomonas and Arcobacter identified as key acetaldehyde degraders. Seventeen bacterial isolates were cultivated from the Colne Estuary and degraded acetaldehyde at a concentration of 2.27 mM, with Halobacillus strains A4 and A5, Rhodococcus strain A14, and Bacillus strain A17 identified as important acetaldehyde degraders. Fourteen previously identified bacteria, belonging to the Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Verrucomicrobia, also degraded acetaldehyde, suggesting that the microbial acetaldehyde sink is highly diverse. Using genomics and proteomics, the pathway of acetaldehyde metabolism used by Rhodococcus strain A14 was proposed. Acetaldehyde is oxidised to acetate by aldehyde dehydrogenase enzymes, with acetate converted to acetyl-CoA via acetyl-CoA synthetase. These reactions are thought to be conserved amongst acetaldehyde-degrading bacteria. Under favourable growth conditions, acetaldehyde is dissimilated to CO2 for energy production via the oxidative decarboxylation steps of the tricarboxylic acid cycle. Acetaldehyde-derived carbon is assimilated into biomass by upregulating the glyoxylate shunt and gluconeogenesis pathway, ensuring carbon is conserved for growth. Using 14C-radiolabelling, rates of microbial dissimilation were shown to be significantly higher than assimilation rates in the freshwater rivers, estuaries, and coastal seas of south-west England, with summer rates significantly higher than winter. These findings suggest that microorganisms exert considerable control over acetaldehyde emissions and represent an important component of the global acetaldehyde cycle.

Many hardware and compiler optimisations introduced to speed up single-threaded programs also introduce additional, sometimes surprising, behaviours for concurrent programs with shared mutable state. How many of these extra behaviours occur in practice depends on the combination of the hardware, compiler, runtime, etc. that make up the platform. A memory model, which prescribes what values each read of a concurrent program can read, allows programmers to determine whether a program behaves as expected without having to worry about the details of the platform. However, capturing these behaviours in a memory model without also including undesirable "out-of-thin-air" behaviours that do not occur in practice has proved elusive. The memory model of C and C++ allows out-of-thin-air behaviour, while the Java memory model fails to capture some behaviours that are introduced in practice by compiler optimisations. In this thesis, we propose a memory model that forbids out-of-thin-air behaviour, yet allows the behaviours that do occur. Our memory model follows operational intuitions of how the hardware and compilers operate. We illustrate that it behaves as desired on a series of litmus tests. We show that it captures at least some of the expected behaviours, that it forms an envelope around some common compiler optimisations, and that it is implementable on common hardware using the expected compilation schemes. We also show that it supports some established programming idioms.

The objective of this study is to identify principal leadership styles and teacher preferred principal leadership styles, as well as to examine the independent and combined effects of these variables on the TAKS Mathematics achievement scores of elementary students. School leadership affects every aspect of an institution. Studies reveal that the principal has a significant impact on student success. Administrators are the instructional leaders and role models for the staff. As such, administrators go through numerous trainings to better articulate their leadership styles to become effective leaders. However, do teachers respond favorably to the managerial style of their principals? This study aims to identify whether principal leadership styles and teacher preferred principal leadership styles, independently or combined, have an effect on student achievement with respect to mathematics achievement. The researcher seeks to explore three main questions: (1) What effects, if any, do the variables principal leadership style and teacher preferred principal leadership style, independent and combined, have on TAKS Mathematics Knowledge and Skills achievement scores of elementary students? (2) What effects, if any, do the variables principal leadership style and teacher preferred principal leadership style, independent and combined, have on TAKS Mathematics Underlying Processes and Mathematical Tools achievement scores of elementary students? (3) What effects, if any, do the variables principal leadership style and teacher preferred principal leadership style, independent and combined, have on overall TAKS Mathematics achievement scores of elementary students? Based on the results derived from the statistical analysis, the researcher discovered that independently the variables principal leadership styles and teacher preferred principal leadership styles did not produce a significant influence on TAKS Mathematics achievement. However, the interaction of the variables principal leadership styles and teacher preferred principal leadership styles, combined, produced a significant finding on students' TAKS mathematics achievement. Also, when an alignment of principal leadership styles and teacher preferred principal leadership styles was present, student achievement was significantly higher than in situations in which there was no alignment. This study provides evidence that the alignment of the principal's leadership style and teachers' leadership preference is essential in the enhancement of student achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.

This dissertation argues for the significance of epistolary correspondence in its ability to exemplify, more successfully than any other medium, the spirit of collaboration in the negotiation of meaning both on a personal scale and on a broad social scale. Collaborative meaning-making allows for multiplicities of identities and truths, thus constructing diverse environments that welcome individuals and ideas that are constantly in motion and in progress, rather than accepting static and limiting definitions. Additionally, this dissertation explores how we might use this understanding of collaborative mediums and genres to improve our own collaborative spaces, namely our classrooms. To this end, I present a number of various critical pedagogies that we might implement into our classroom, emulating these authors in their capacity for inclusion and their refusal to settle for those definitions and limitations imposed upon them by societal standards of the day. The pedagogies explored include gender-neutral language in the second language classroom, trauma-informed approaches to texts containing violent material, and negotiations of relationships within hierarchies in the higher-education context. I hope that this work—in its attempt to consider pedagogy and research as intrinsically linked and mutually beneficial to each other—helps initiate discussions in classrooms and academic settings on the potential of collaboration between our two primary expectations within our universities, and the many ways in which our passion for our subject area can grow in unexpected directions when brought into the classroom.

Exposure to ultraviolet radiation (UVR) is a key risk factor for skin cancer. Current recommendations include sun avoidance, wearing protective clothing, and using sunscreen with an SPF of 15 during midday sun exposure. Few studies have examined sun protection behaviors among African Americans. The paucity of sun protection literature among this group is likely due to low incidence and misconceptions that darker skin offers protection against damaging effects of UVR. The literature indicates that African Americans suffer from disproportionally high rates of skin cancer mortality. Therefore, it is important to investigate current sun protection behaviors among African Americans given these data. The primary objective of this study was to assess the prevalence and potential correlates of sun protection behaviors among a random community sample of African Americans. An anonymous health survey was administered door-to-door in 12 randomly selected census tracts in Los Angeles and San Diego Counties. African Americans were sampled from random block groups within these tracts, which varied by residential segregation and poverty levels. Participants were asked to report their frequency of sunscreen, wide brim hat, and sunglasses use during the summer on a 5-point Likert scale ranging from "never" to "always". Potential correlates of sun protection behaviors included demographic and phenotypic characteristics, skin cancer risk perception, and contextual factors. A total of 1,453 self-identified African Americans completed the health survey. The mean age was 45 (SD=16.2) ranging from 18 to 94 years. The prevalence of sun protection (% always) was 7.8% for sunscreen, 10.2% for wide brim hat, and 27.1% for sunglasses. Multivariate analyses showed that being female, having higher educational attainment, and higher income were significantly related to sunscreen use; males and older adults were more likely to wear a wide brim hat; and females and individuals with a higher income were more likely to always wear sunglasses. There were no significant associations between the other potential correlates and the three outcomes in the multivariate analyses. The key findings highlight 1) disparities in sun protection prevalence, and 2) predictors of sun protection behaviors among African Americans. Recommendations for future research and practice are discussed