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Genetics and genomics of invasive Anopheles stephensi : insights into vector adaptations, molecular surveillance, and footprints of vector-microbe interactions.
No full textAnopheles stephensi is an invasive, competent malaria vector that has consistently spread across the Horn of Africa and the Arabian Peninsula over time, driving outbreaks and challenging control efforts. This dissertation examines the biology and evolution of invasive An. stephensi populations in the Horn of Africa and their interactions with microbes. Expanded surveillance for this vector across sub-Saharan Africa has necessitated a standard method of identification, to ensure conclusive An. stephensi species confirmation and to allow for comparable data across the continent. Molecular screening of wild An. stephensi revealed naturally occurring Wolbachia pipientis in eastern Ethiopia, highlighting a potential method for vector or malaria control with continued surveillance and study. Genetic markers related to Plasmodium-Anopheles compatibility were sequenced during an An. stephensi-caused malaria outbreak in Dire Dawa, Ethiopia, which revealed the transmission of African P. falciparum by invasive An. stephensi. Genome-wide analysis of populations from 2018 and 2022 revealed regions of the genome under multiple evolutionary forces, ultimately highlighting the need for further study of An. stephensi genomics
Teaching through a pandemic : a single case study exploring the perceived reintegration and resiliency of teachers.
No full textDue to the teacher attrition problem in the United States, it is crucial to find ways to support educators more effectively in the classroom. The COVID-19 pandemic disruption exacerbated teaching frustrations, particularly online. Richardson (1990) viewed disruptive factors as "an opportunity for the individual to become more resilient for future life events" rather than as a failure. Despite ongoing disruptions, some educators remain and manage to reintegrate with resiliency. This dissertation presents a qualitative single-case study exploring the perceived resilience of teachers reintegrating into a public K–12 setting post-COVID-19 pandemic.
This single case study site was a K–12 public charter school in western North Carolina. I collected data from four participants, who met the inclusion criteria for teachers who had been at the site for the last four years or more. The study used questionnaires, journal entries, and semi-structured interviews to gather collective narrative perspectives from participants, thereby providing a rich understanding of teacher resiliency post-reintegration. I applied Richardson’s (2002) resilience model as the theoretical framework. The purpose of this study was to explore how the disruption of the COVID-19 pandemic influenced teachers’ perceived reintegration into the post-pandemic work environment and the potential role of resiliency in educators’ experiences.
The six findings of this study fell under three categories: workplace, resiliency, and reintegration. First, participants perceived that their workplace had changed due to increased safety concerns due to the pandemic. Second theme found that participants perceived that workplace frustrations increased due to the COVID-19 pandemic disruption. Within the resiliency category, participants expressed feeling supported, which encouraged them to remain resilient during the COVID-19 pandemic disruption. Fourth, participants described a sense of purpose that encouraged them to remain resilient during the COVID-19 pandemic disruption. Fifth, within reintegration, participants expressed that hybrid and virtual learning led to increased workplace complications and stressful demands. Sixth, participants perceived dysregulated students as an ongoing barrier to resilient reintegration. This study has implications for teachers, administrators, and school board members
The impact of inquiry-based learning on students and teachers.
No full textMotivated by an increasing focus on test scores in Texas public schools and student questioning of the purpose of their schooling, this research study focuses on purposeful, authentic learning. Conducted at Parkway Elementary with 5th grade students, this study seeks to answer the following research questions: What impact does an inquiry framework, specifically researcher’s workshop, have on student engagement, mindset, and higher-order thinking skills? What impact does an inquiry framework, specifically researcher’s workshop, have on the role of the classroom teacher? With the utilization of Inquiry Illuminated: Researcher’s Workshop, researchers conducted a cross-curricular, inquiry-based unit focused on World War II, the comprehension of expository texts, and higher-order thinking skills. Research revealed an increase in student engagement, a shift in student mindset toward learning, evidence of the development of higher-order thinking skills, and a shift in the teacher’s role in the classroom
A genomic and transcriptomic investigation of the circadian clock regulation of insect diapause in Culex pipiens.
No full textThe West Nile virus vector, Culex pipiens, undergoes seasonal reproductive dormancy as an anticipatory response to shortening photoperiod during fall to overwinter. During this developmental trajectory, females exhibit diapause-specific characteristics that are suited for a prolonged lifespan and enhanced stress tolerance, enabling them to cope with a detrimental environment. Diapause is a well-established photoperiodic response accompanied by cellular and behavioral reprogramming. However, our current understanding is limited to recognizing the necessity of the circadian clock in the processing of photoperiodic information, while still lacking mechanistic details of how this information is transduced to cellular signaling pathways. This gap warrants further investigation to understand the cellular intricacies underlying diapause and potentially leverage this knowledge for vector control strategies. Our research investigated the role of clock transcription factors and identified their putative targets by employing a ChIP-seq approach. Through this work, we have identified and validated the targets of clock transcription factor CYCLE and PAR DOMAIN PROTEIN 1 that contribute to the diapause-specific attributes in the mosquito vector. Additionally, through RNA-seq, our study characterized the transcriptional dynamics in the heads of diapausing and nondiapausing females, as well as temporal variations within each phenotype. This analysis underscores the interaction of phenotypic and temporal factors in orchestrating transcriptional programming suited for diapause. Collectively, our results provide novel insights into the regulatory control of clock transcription factors at the gene level and provide diapause-associated transcriptomic modulation in the mosquito head that is possibly mediated by circadian clock genes
The crystal growth and characterization of cerium manganese germanide intermetallics.
No full textIntergrowth phases in intermetallic systems provide a compelling framework for investigating structure–property relationships as a function of crystallographic subunit stacking. In this study, we examine the influence of Mn vacancy ordering on subunit stacking and reassign the structure of Ce 2 MnGe 6 to a monoclinic C2/m space group (a = 8.3486 (17) Å, b = 8.6181 (18) Å, c = 10.778 (2) Å, β = 101.17 (2)º). Additionally, we report a monoclinic polymorph of the Ln2 MGe 6 family and characterized as a tripled c-axis supercell derivative of monoclinic Ce 2 MnGe 6 , 3×c-Ce 2 MnGe 6 (a = 8.3482 (16) Å, b = 8.6179 (18) Å, c = 31.813 (6) Å, β = 93.763 (7)º). This polymorph emerges under rapid cooling conditions during synthesis and offers insight into the structural relationship between the orthorhombic and monoclinic variants of the Ln2MGe 6 phases. Notably, the upercell form of Ce 2 MnGe 6 (3×c-Ce2 MnGe 6 ) exhibits increased electrical resistivity and suggests enhanced Zintl-like behavior, potentially indicating greater thermodynamic stability relative to the parent monoclinic phase
Examining students’ perceptions of culturally responsive teaching at a Northeastern United States middle school : a quantitative survey study.
No full textThe underrepresentation of culturally responsive teaching (CRT) increases the opportunity gap and hinders the long-term success of students of color (Hernandez, 2022). Educators frequently lack the skills needed to implement CRT, a vital approach for creating inclusive environments that support students from diverse backgrounds and address the opportunity gap (Abdalla & Moussa, 2024). Teachers and school staff require practical examples and resources to effectively tackle the achievement gap and disproportionality within their schools (Griner & Stewart, 2013). CRT is underutilized, limiting educators’ abilities to address the opportunity gap and support the success of students from diverse backgrounds.
The purpose of this quantitative survey study was to examine relationships among students’ perceptions of their teachers’ diverse teaching practices, cultural engagement, and affirmation of diverse languages before and after a CRT intervention at a Northeastern United States middle school. Dickson et al.’s (2015) CRT model served as the study’s theoretical framework. The framework incorporates the following constructs: diverse teaching practice, cultural engagement, and language acquisition. Participants included 60 sixth-grade students from diverse racial, ethnic, and gender backgrounds, taught by a single teacher who employed a culturally relevant teaching intervention.
After analyzing the Student Measure of Culturally Responsive Teaching (SMCRT) scale, I compared pre- and posttest results. I found strong statistically significant positive correlations among diverse teaching practices and cultural engagement (r = .63) and cultural engagement and language affirmation (r = .59). Further, I found a medium statistically significant positive correlation between diverse teaching practice and language affirmation (r = .47). However, after using dependent samples t tests to compare differences among students’ perceptions of their teacher’s diverse teaching practices, cultural engagement, and affirming diverse languages after the intervention, I did not find statistical or practical significant results among the scores.
The study highlights that the chancellor and central office policymakers can promote curriculum autonomy and support professional development by using tools like the SMCRT scale to assess CRT practices. Administrators can align instructional focuses and professional development with CRT. Teachers could use the SMCRT tool as a reflective strategy to enhance their culturally responsive practices
Striving for fairness : exploratory case study of Black female Virginia magistrates’ experiences and their intersecting identities as decision makers in the justice system.
No full textAs conversations among legal professionals and policymakers about equity and representation in the legal system gain momentum, it is essential to examine the unique perspectives of those historically marginalized within its ranks. Racial and gender disparities continue to shape the American justice system, influencing both legal outcomes and the experiences of those administering justice. Black women remain significantly underrepresented in judicial roles, creating a gap in understanding how their intersecting identities influence their professional experiences. In Virginia, magistrates serve as the first point of contact in the criminal process by issuing warrants, determining probable cause, and setting bail, occupying a critical position in shaping perceptions of fairness and legitimacy. Despite this pivotal role, little research has examined how Black women magistrates interpret and perform their duties within a system historically designed without their inclusion.
The purpose of the single case study was to examine how four Black women magistrates in Virginia described their experiences and decision-making processes. The study employed an intersectionality framework rooted in Crenshaw’s (1989, 1991) foundational focus on intersecting identities and expanded by Collins (2015; Hill-Collins (2019) to incorporate oppression and power relations. I collected data through semi-structured interviews, a focus group, and a reflective questionnaire. Following the data analysis spiral, I began with three a priori categories, intersecting identity, oppression, and power relations, before applying descriptive coding to develop thematic statements.
Findings revealed that participants frequently faced challenges to their legitimacy, including heightened scrutiny and assumptions of bias based on race and gender. Despite these obstacles, they demonstrated resilience by integrating formal legal training with lived experience to promote fairness and equity in decision-making. Their narratives highlighted how intersecting identities shaped professional interactions, influenced perceptions of authority, and informed strategies for maintaining impartiality while fostering trust and confidence. These insights advanced scholarly understanding of intersectionality in judicial spaces and underscored the need for institutional policies that recognized identity as a factor in decision-making. The study’s implications included improving judicial training to incorporate cultural competency, developing leadership pathways for underrepresented groups, and addressing structural barriers to diversity in the magistrate system
Interrelation between Late Quaternary anthropogenic, hydrogeologic and geomorphic processes for the evolution of the Monahans and the Kermit Dune Fields, northern Chihuahua Desert, West Texas, USA.
No full textPerched aquifers of the Monahans and Kermit dune fields, West Texas, represent previously unquantified water resources in the Northern Chihuahua Desert. These tall aeolian systems consist of up to 50 m of sand overlying a Pliocene/Pleistocene fluvial clay aquitard, with perched water tables only 1–10 m below the surface. These shallow aquifers enhance dune stability and may contribute to the Pecos Valley Aquifer (PVA) annual recharge, yet they are increasingly stressed by aridification, oil and gas activity, and sand mining.
This dissertation aims to understand the evolution and vulnerability of these systems. The first study reconstructs hydrostratigraphy and recharge pathways using cores, OSL dating, isotopic analyses, and 3D modeling. Results indicate groundwater volumes >0.1 km³ in each aquifer, contributing up to 18% of annual recharge to the PVA, while carbon isotope models reveal possible hydrocarbon contamination.
The second study evaluates seasonal and diurnal groundwater fluctuations in the Kermit Dunal Aquifer (KDA) from 2021–2024. Central dunes show rapid responses to rainfall, while the western margin seems disconnected from precipitation by evapotranspiration and a deeper vadose zone. Water levels exhibit diurnal evapotranspiration cycles and long-term declines (~1.2 m) linked to drought conditions and expansion of mining ponds.
The third study quantifies aquifer properties and provides a revised water balance using slug tests and hydrologic modeling. Results confirm low hydraulic conductivity and transmissivity and highlight evapotranspiration and industrial withdrawals as important discharge pathways. Contributions to the PVA are now only 0.24% of annual recharge, far lower than pre-mining estimates.
This dissertation demonstrates that dunal aquifers of the Monahans and Kermit systems are significant but fragile groundwater resources. Their recognition underscores the need for systematic monitoring and sustainable management to mitigate impacts of climate variability and industrial development
The role of age, race, education, and online experience in predicting online learning self-efficacy : a quantitative study.
No full textThis quantitative correlational study investigates the interplay of online learning self-efficacy variables that affect online learners from a connectivist theoretical viewpoint (Siemens, 2005). The research addresses the urgent need to evaluate the needs of online learners in response to the Fourth Industrial Revolution’s emerging technologies (Mapping the Digital Divide, 2015; Schwab, 2016; Vogel-Walcutt et al., 2019). Using a cross-sectional survey featuring the Online Learning Self-Efficacy Scale (OLSS) as the validated instrument (see Appendix C), the study explores correlations between demographic factors like age, race, education level, and length of prior online learning experiences with OLSS measures like online learning tasks self-efficacy, technology-use self-efficacy, self-regulation and motivation self-efficacy, and instructor and peer interaction and communication self-efficacy (Sun & Rogers, 2021). The study aims to understand how self-efficacy influences technology-use and communication during online learning tasks, to improve digital literacy and academic outcomes in online education, particularly among underrepresented demographics (Chetty et al., 2018; Mamedova & Pawlowski, 2018).
Key findings indicate that information and communication technologies (ICTs) have significantly transformed the educational landscape, leading to decentralized information and increased accessibility (Margaryan et al., 2015; Q. Wang et al., 2013). Furthermore, students with high self-efficacy demonstrated better academic outcomes, as well as higher levels of self-regulation, motivation, and technology-use (Bandura, 1977; Broadbent & Poon, 2015; Zimmerman, 2002). However, demographic variables such as age, educational level, and online learning experience significantly impact technology-use and digital literacy skills, which are required for successful online learning outcomes (M. Anderson & Perrin, 2017; S. A. Brown et al., 2010; Nikou et al., 2022). Furthermore, the study emphasizes the importance of integrating technology into teaching and developing digital literacy to prepare students for the future of work during the digital age of the fourth industrial revolution (Ainsworth & Knox, 2022; Allen, 2017; Schwab, 2016). These findings underscore the need for educational strategies that address the digital divide and promote inclusive online learning, contributing to developing more effective learning strategies that address self-efficacy disparities and prepare students for the demands of an interconnected and digitally mediated world
Exploring caregiver engagement in adolescents with emotional disturbance : a qualitative single case study.
No full textCaregiver engagement is a critical factor in the success of adolescents with emotional disturbance (ED), yet caregivers of these students often face unique and compounding barriers that limit their involvement. Despite the recognized benefits of caregiver engagement, caregivers of students with ED are less engaged compared to caregivers of students in general education or other disability categories. This disparity in engagement highlights the need for targeted interventions and support specifically designed for caregivers of students with ED.
This study explores the perceptions of caregivers of middle school students with ED in an alternative school in Vermont, a state with one of the highest rates of students identified with ED. Vermont as the study location provides a unique context, allowing for insights into a region where the prevalence of ED is particularly high. This study investigates how caregivers describe their engagement and examines their perceived resources and demands that influence their involvement in their child’s education.
This study employed a qualitative single case study to explore caregiver engagement through the lens of McClusky’s (1963; 1970a) theory of margin, which examines the balance between an individual’s power and load. Four mothers of middle school students with ED participated in an open-ended questionnaire and semi-structured interviews. I analyzed the data using thematic analysis to identify patterns in engagement, perceived barriers, and available supports. The study focused on understanding how caregivers navigate their involvement in their child’s education while managing personal and systemic challenges. The caregivers’ lived experiences provides valuable insights into the practical realities of supporting a child with ED in the education system.
Findings revealed that the participants directly engaged in multiple ways, including communicating with the school, attending meetings, and bringing in support from outside the school. The study also uncovered significant barriers faced by caregivers, such as stress, school-related challenges, and financial constraints. These barriers highlight the complex interplay of personal, institutional, and societal factors that can impede caregiver engagement. This research underscores the importance of systemic support for caregivers of vulnerable student populations. By addressing barriers, schools can potentially improve outcomes for students with ED