OAsis: UNLV's Repository for Research, Scholarship, and Creative Activity
Not a member yet
24968 research outputs found
Sort by
Dysregulation of Vitamin D Receptor and CYP450 Metabolism Enzymes May Explain Oral Cancer Responsiveness
No full textMany health benefits are associated with Vitamin D (VitD), although deficiency is associated with poor health outcomes and increased risk for cancer development. For example, many tissue specific enzymes are involved in VitD metabolism, and mutations or deletions within Vitamin D receptor (VDR) genes are known to increase cancer risk by altering their functions or bioavailability, although less is known about these phenomena in oral cancers. Using well characterized, commercially available oral cell lines (OKF4, HGF-1, SCC4, SCC9, SCC15, SCC25, CAL27), mRNA expression of P450 cytochrome VitD metabolic enzymes and receptor genes by qPCR revealed differential results. One oral cancer line (SCC15) did not express either receptor or entry genes VDR or FOK1 and was also least affected by VitD3 administration in growth assays. In contrast, most oral cancers were missing one or more hydrolase (CYP2R1,CYP24A1) or hydrolate (CYP27A1, CYP27B1) enzymes. SCC25 was missing both hydrolate enzymes and was the most inhibited in VitD3 growth assays, while SCC4 was missing both hydroxylase enzymes and was the least inhibited by VitD2. These associations between mRNA expression (or lack thereof) and VitD3 and VitD2 responsiveness identify molecular targets, which may lead to effective screening tools for VitD-related complementary and alternative therapies
High Dynamic Range Actively Quenched Silicon-Germanium Single-Photon Avalanche Diodes
No full textSingle-photon avalanche diodes (SPADs) are solid-state devices capable of providing large current pulses in the milliampere range in response to incident photons. The large gain inherent to SPADs makes them a popular technology for photon-counting applications, but their operation can be hindered by long recharge times, which necessitates the use of active quenching to reduce dead times and increase detection rates. For the prompt gamma/neutron radiation experiments conducted at the Nevada National Security Site, photomultiplier tubes (PMTs) have been the primary photodetector of choice, but their continued use is expected to dwindle as it becomes increasingly difficult to source quality PMTs due to aging of the technology. As a result, alternative means of photodetection are currently being researched, with SPADs being one of the devices of interest.This thesis details the development of high dynamic range, actively quenched silicon-germanium (SiGe) SPADs capable of meeting the performance targets set by the NNSS for the intended application, which requires reset times of 1-2ns maximum and full-width-half-max output pulses in the 100-500ps range or less. The beginning of this process involved testing a multitude of SiGe SPADs previously developed by the lab using the Austriamicrosystems 0.35μm SiGe BiCMOS process and determining which device structure and size yielded the shortest pulse widths (an indicator of a small junction capacitance, a desired parameter for the aforementioned metrics). Once the ideal SPAD structure was identified, a 5μm-by-5μm square structure without guard rings, the device was further tested to characterize its current response to varying degrees of reverse biasing. Using this information, an LTspice model was developed to emulate the SPAD’s behavior to facilitate more accurate simulations of the final two active quenching integrated circuit designs, which were developed using TSMC’s 180nm process. The variable-load active quenching design was able to achieve a nominal reset time of 738ps with a 103ps FWHM output while the latching active quenching design provided a nominal reset time of 735ps with a 73ps FWHM output, indicating that both designs can theoretically resolve 1Gcps (gigacounts per second) reliably. Preliminary layouts of the actively quenched SPAD pixels with integrated analog counting were created using TowerJazz’s 180nm SiGe BiCMOS process, the process in which the final chip will ultimately be manufactured
Endurance in Education: A Mixed Methods Study of Teacher Retention
No full textThis study explores the role of organizational culture and individual teachers’ psychological capital (PsyCap)—comprising of hope, efficacy, resilience, and optimism—in their retention decisions. Using the Competing Values Framework (CVF) and research from positive organizational psychology, the study examined how different types of organizational cultures either support or hinder teacher retention, both directly and indirectly through their influence on PsyCap. A mixed-methods research design was employed to gain a comprehensive understanding of the research problem by integrating quantitative findings with qualitative insights.The findings suggest that collaborative and innovation-driven school cultures play a critical role in enhancing teacher PsyCap and increasing the likelihood that teachers want to— and intend to—return to their schools the following year. In contrast, hierarchical and market oriented cultures showed no direct impact on teacher retention decisions. However, qualitative data highlighted the importance of trust in teacher-administrator and coworker relationships in supporting both PsyCap and teachers’ decisions to remain at their schools. Trust can be weakened in market-oriented cultures due to the competitive nature of such environments. The influence of hierarchical cultures on PsyCap appears to vary by teacher experience: newer teachers tend to prefer clear policies to guide their work, while more experienced teachers, confident in their abilities, rely less on such guidance—except when it comes to non instructional responsibilities, such as managing student discipline, where teachers across experience levels expressed a need for clarity and consistency. Future research should employ longitudinal designs to establish causality, explore the relationship between retention and teacher quality, and examine the career trajectories of surplus teachers
Arrhythmogenic Right Ventricular Cardiomyopathy: A Comprehensive Review
No full textArrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by structural abnormalities, arrhythmias, and a spectrum of genetic and clinical manifestations. Clinically, ARVC is structurally distinguished by right ventricular dilation due to increased adiposity and fibrosis in the ventricular walls, and it manifests as cardiac arrhythmias ranging from non-sustained ventricular tachycardia to sudden cardiac death. Its prevalence has been estimated to range from 1 in every 1000 to 5000 people, with its large range being attributed to the variability in genetic penetrance from asymptomatic to significant burden. It is even suggested that the prevalence is underestimated, as the presence of genotypic mutations does not always lead to clinical manifestations that would facilitate diagnosis. Additionally, while set criteria have been in place since the 1990s, newer understanding of this condition and advancements in cardiac technology have prompted multiple revisions in the diagnostic criteria for ARVC. Novel discoveries of gene variants predisposing patients to ARVC have led to established screening techniques while providing insight into genetic counseling and management. This review aims to provide an overview of the genetics, pathophysiology, and clinical approach to ARVC. It will also focus on clinical presentation, ARVC diagnostic criteria, electrophysiological findings, including electrocardiogram characteristics, and imaging findings from cardiac MRI, 2D, and 3D echocardiogram. Current management options—including anti-arrhythmic medications, device indications, and ablation techniques—and the effectiveness of treatment will also be reviewed
Structural Challenges in TVET-Industry Collaboration: A Social Justice Lens
No full textTechnical and Vocational Education and Training (TVET) is critical and indispensable in ensuring that the socio-economic inequalities and challenges facing not only South Africa, but also Africa, are reduced. This can be achieved by providing access to skills development, particularly for previously and historically marginalized sections of society, such as the youth. The main aim of this examination was to explore TVET collaboration with industry in promoting social justice. Social justice is deployed as a theoretical lens since social justice and education are characterized by a symbiotic relationship. In its investigation, we employed the qualitative case study approach, which involved interviews with academic support officers and business studies and engineering interns to explore lived experiences. These participants were drawn from the experiences of three different categories, selected for their direct involvement in the TVET system. The first group was made up of the three academic support service staff members: The second group consisted of six business studies interns: The third group included five engineering studies interns. The main finding of the study highlights, among others, structural and pedagogical challenges, a weak TVET-industry partnership, a lack of industry involvement in curriculum design, the absence of relevant resources from TVET colleges for industry-ready student placement, and underqualified lecturers
Unpacking Violence: Examining Socioeconomic, Psychological, and Genetic Drivers of Gun-Related Homicide and Potential Solutions
No full textBackground: Gun-related homicide remains a persistent public health crisis in the United States, with over 48,000 firearm-related deaths reported in 2022, including 19,651 homicides and 27,032 suicides. Despite frequent calls for tighter gun control, firearm access alone does not explain the complexity of violence. Objective: This commentary aims to unpack the socioeconomic, psychological, and biological drivers of gun-related homicide and propose integrative, evidence-based solutions that extend beyond legislative reform. Methods: We synthesized data from peer-reviewed literature, national crime and health databases (e.g., Centers for Disease Control and Prevention and Federal Bureau of Investigation), and international reports. We examined patterns related to poverty, trauma, male aggression, neurobiology, and firearm acquisition, as well as cross-national comparisons with countries like Switzerland and Mexico. Findings: Young males, particularly those aged 10–29, accounted for 50% of homicide offenders in 2022. African Americans experienced homicide rates of 23.1 per 100,000, ten times the rate among Whites. Up to 56% of incarcerated men report childhood physical trauma, and over 40% of those in prison exhibit symptoms of serious mental illness. While firearm legislation varies widely, analysis reveals that over 90% of crime guns are acquired illegally or through informal sources. International comparisons show that poverty and weak rule of law, more than gun laws alone, correlate with elevated homicide rates. Conclusions: Reducing gun violence sustainably requires a multifaceted approach. Authors advocate for investments in trauma-informed mental health care, focused deterrence programs, early childhood interventions, and improved enforcement against illegal gun trafficking. A public health strategy that integrates social reform with targeted regulation holds the greatest promise for long-term change
The Safety Net Should Work for Working Age Adults
No full textThis lecture focuses attention on a population that is ill-served by the safety net but rarely acknowledged: low-income, working-age adults without dependents or government-determined disabilities. In this lecture, Brookings Scholar Lauren Bauer, a former Special Assistant in the Office of the Secretary at the US Department of Education, argues that a safety net that is inaccessible to ABAWDs (able-bodied adults without dependents) fails to recognize the precarious state of the low-wage labor market or how safety-net programs allow these workers to remain in the workforce. By modernizing the parameters of who qualifies for access to safety-net programs, assistance can be made available for low-income, working age Americans who have a vital, but often invisible role in the economy
Preparing Students for Adulthood: Comparing the Experiences of Degree and Non-Degree Seeking Graduates
No full textThe role of secondary education is critical to preparing graduates for adulthood. This study explored the transition experiences of high school graduates and factors that impacted their preparation for adulthood. This descriptive study focused on the experiences of degree and non-degree-seeking graduates. Surveys were distributed to students enrolled in a general education course at a state university and marketing research participants not enrolled in post-secondary programs. The survey sought to identify overall preparedness, responsibilities deemed necessary to teach in high school, and influence factors that prepared them for adulthood. The overall findings displayed that graduates seeking degrees felt more prepared for adulthood. While both groups agreed that many adulthood-responsibility topics should be taught, degree-seekers found less value in teaching parenting skills in a high school class despite identifying that parents have a more significant impact on preparing them for adulthood. Researchers recommend that in addition to college and career-ready curricula, instruction should include preparation topics that align with 21st-century markers that better support non-degree-seeking graduates toward successful transitions into adulthood
The Impact of Educating Interprofessional Healthcare Workers on the Role of Occupational Therapy in the Cardiac Acute Care Setting
No full textThe acute care setting has been a vastly growing practice area for the occupational therapy profession. Occupational therapists assist clients in the acute care setting with activities of daily living retraining and functional transfer training to increase independence. Each client demonstrates a different discharge course from the acute care setting and occupational therapists play a key role in assisting the clients the most appropriate rehabilitative setting. All professionals in the acute care setting work cohesively to provide clients with the best outcome.
The doctoral project explored the importance of interprofessional healthcare worker education about occupational therapy practices in the acute care setting. Healthcare workers were provided with an informational session reviewing the role of occupational therapy in the rehabilitation process for acute care patients with a cardiac related diagnosis. The use of professional feedback and surveys were utilized to gather healthcare workers’ insights on the benefits of the informational session and education. The implementation of this project was created to explore the educational knowledge of interprofessional healthcare workers on the role of occupational therapy in the acute care setting. Additionally, the implementation of the project was created to gain insight about the efficacy of educational advocacy for occupational therapy
“Minimal-Impact” Las Vegas Spaceport
No full textThe development of a Minimal-Impact spaceport stands as a pivotal stride in the pursuit of sustainable aerospace initiatives, bridging the gap between human progress and environmental care. This thesis seeks to explore the emotional impact of architecture on guests, drawing parallels from the world of aerospace to examine how the design of spaces, such as those in Las Vegas, significantly influences the emotions of visitors. By conceptualizing a Minimal-Impact spaceport that minimizes ecological footprint, optimizes resource efficiency using local resources, and seamlessly blends with its natural environment, this thesis contends that a spaceport should adhere to a new set standard in responsible aerospace infrastructure and strive to create a substantial emotional impact on its visitors.https://oasis.library.unlv.edu/arch_grad_capstones/1056/thumbnail.jp