6834 research outputs found
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Markers of bioenergetic changes in liver tissue from obese and lean tumor-bearing mice.
No full textCancer cachexia is associated with the decreased quality of life and has potential to dysregulate whole-body metabolism. The liver is highly understudied in the literature yet is a prominent figure in whole-body metabolic regulation. The purpose of this study was to examine changes in biomarkers of bioenergetics in liver tissue of lean and obese cachectic mice. Mature male mice were fed chow (lean) or 12 weeks of high fat diet (obese). Following the diet intervention, groups were further divided into PBS control or LLC tumor-bearing mice. Tissues were collected 25 days post-injection. Tumor progression in obese mice was correlated with increased expression of lipid metabolism genes, no difference in expression of glucose metabolism genes when compared to the PBS group, and no difference in expression of mitochondrial biogenesis genes when compared to the PBS group
Ideal Portfolio Allocations Maximizing Sharpe Ratios.
No full textIn finance, the main goal is finding the most appropriate use of funds for a given purpose to grow the value over time with the appropriate allocation of resources to achieve their specific goals most efficiently. What is essential to understand from this aspect for the people who manage personal funds, namely, money managers, is where to invest their client's money to maximize returns and lower risk. The portfolio manager is responsible for determining portfolio allocation that aligns with their clients' return and risk requirements. In this context, the optimal portfolio is the one that achieves maximum returns while adhering to the client's specified risk tolerance. A crucial aspect of financial management involves comprehending shifts in portfolio allocations and their underlying causes. Such insight not only enhances decision-making but also serves as a valuable predictor of potential future ideal portfolios, including the assets they comprise and their respective weights
Through the educators' eyes : a single case study of public-school teachers experiencing burnout amid a pandemic.
No full textPrior to the COVID-19 pandemic, burnout plagued teachers throughout the world. Common complaints included a lack of resources, increased workload, insufficient support systems, and intense pressures and demands. Prolonged stressors led to feelings of exhaustion, cynicism, and inefficacy. However, once the COVID-19 pandemic hit, it dramatically transformed the face of teaching and brought about new challenges and concerns for educators worldwide. The new challenges included the need for more technology training, support, and equipment, at-home support for younger elementary students, and the need to transform the traditional curriculum into an online format. The new challenges caused an increase in the workload, demands, and pressures placed on teachers. This qualitative single case study explored the experiences of four Northern California teachers teaching across three modalities during the COVID-19 pandemic. The modalities included distance-only, hybrid, and in-person instruction. The theoretical framework used was Maslach's burnout theory. Maslach's theory and its three components provided a foundation for the burnout study and a lens to analyze the data. I used purposive, criterion sampling to select the participants and collected data through semi-structured interviews, artifacts, and documentation. Data analysis consisted of reviewing collected data, organizing codes into themes, interpreting, and representing data, and checking for accuracy. The study allowed valuable insight into the experiences of teachers teaching during the COVID-19 pandemic. Participants described experiences added to emerging COVID-19 teacher burnout literature. Participants experienced increased chronic interpersonal stressors, exhaustion, cynicism, and a diminished sense of self-efficacy while teaching across the modalities within their work environment. Participants described hybrid teaching as the most difficult to teach of the three modalities. The study indicated the need for districts to address teacher burnout, teachers' mental health and well-being, and provide support and training to teachers. Further, the study showed the need for public school districts to improve teacher working conditions and decrease the workload
Cardiac gene expression in early and late-stage pre-clinical cancer cachexia.
No full textCancer cachexia is a multifactorial syndrome characterized by decreased food intake, unintentional muscle and body weight loss, psychosocial and physical challenges, cardiac atrophy, and decreased heart function. In this preclinical study, a colon-26 adenocarcinoma mouse model of cachexia was used to study cancer-associated cardiac gene expression at an early-stage and late-stage timepoint in cachexia development. Tissue weights and body weights were recorded and analyzed, and gene expression was investigated via RT-PCR at each timepoint to identify potential sex effects, tumor effects, and sex x tumor interactions. There was a significant increase in inflammation in mice with tumors at the early-stage timepoint. At the late-stage timepoint, autophagy proteolysis, fatty acid ß-oxidation, and inflammation genes were shown to be significantly altered in tumor-bearing mice. In conclusion, inflammation is shown to drive cancer cachexia related cardiomyopathy as severity progresses into a late-stage timepoint with altered metabolism
Hispanic male students' perceptions of the direct and signal influences that affect their academic performance : a single case study.
No full textAccording to the National Assessment of Educational Progress (NAEP), Hispanic middle school males have exhibited lower academic performance over the last decade in reading and mathematics when contrasted with their White counterparts. In the state of Texas, the Academic Performance Report for 2020–2021 by the Texas Education Agency indicated Hispanic middle school students also demonstrated academic underperformance in comparison to White middle school students in grades 6–8. This discrepancy was evident in reading and mathematics state assessments in 2019 and 2021. Amid the challenges posed by the COVID-19 pandemic, the 2021 State of Texas Assessment of Academic Readiness (STAAR) test revealed that Hispanic eighth-grade students' performance lagged compared to their White counterparts. The purpose of this study was to explore Hispanic male students' perceptions of direct and signal influences that affect their academic performance. Guided by the Social Equity Theory (SET), I collected data using two semi-structured interviews and reflection documents. I used the data analysis spiral to analyze data iteratively, generating codes, categories, and themes. This approach helped me understand the social processes' influence on the participants' academic performance and experiences while aligning with the SET framework. The study revealed four main findings. First, Hispanic middle school males perceived teacher support grounded in care and recognition positively influenced their academic performance. Second, Hispanic middle school males perceived individualized academic support, explicit instruction, engagement opportunities, and opportunities for self-initiation positively influenced their academic performance. Third, Hispanic middle school males generally did not perceive signal influences related to teacher actions, messages, affirmations, and teacher demeanor. Lastly, Hispanic middle school males generally did not perceive signal influences related to disciplinary expectations, fairness, and treatment to influence their academic performance. These findings have implications for district leaders and administrators, teachers, parents of Hispanic middle school males, and researchers
The evolution and dispersal of the invasive malaria vector, Anopheles stephensi : a genomic approach.
No full textAnopheles stephensi, a primary malaria vector in South Asia and parts of the Middle East, has been detected in countries in Africa, Yemen, and Sri Lanka. In Africa, the detection of An. stephensi has been associated with malaria outbreaks in the Horn of Africa region, threatening global efforts for malaria reduction and elimination. The spread of An. stephensi, with a coincident increase in malaria disease burden, led the World Health Organization to issue a "vector alert" in 2019, calling for targeted An. stephensi control and increasing surveillance in Africa and neighboring malaria-endemic regions. To combat this invasive disease vector, understanding the history of introduction(s), establishment(s), and potential source populations is essential to predict future expansions and establish where they may be effectively controlled. To this end, this dissertation involved the application of genetic and genomic approaches to characterize invasive An. stephensi populations in the HoA and Yemen. First, using a DNA-targeted approach, we investigated the evolution of the pyrethroid resistance kdr mutation in the invasive An. stephensi from Ethiopia for the first time. Our finding showed that kdr target site resistance is not the primary insecticide resistance mechanism. Secondly, we assayed 1,680 neutral SNP markers of the HoA An. stephensi, from which principal component and ancestral genetic analyses revealed an isolation-by-distance dispersal pattern with one of the major hubs corresponding to a recent malaria site in Ethiopia. Thirdly, we assayed 2,270 neutral SNP markers of the Yemeni An. stephensi from which pairwise Fst and genetic network revealed the dispersal patterns with Aden An. stephensi as a source population within Yemen. Comparative genomic analyses showed that the Yemeni An. stephensi is younger than Somaliland, northeastern Ethiopia, and east central Ethiopia An. stephensi. Lastly, using entomological and genomic data, we detected and molecularly confirmed the presence of the invasive An. stephensi in an eastern Ethiopian town for the first time. We then uncovered the source population that founded the new An. stephensi colony. Overall, this dissertation shows how genomic data can provide finer-scale population structure to uncover dispersal patterns and source populations and help elucidate evolutionary relationships between invasive An. stephensi populations
Reconstructing the early Paleocene light environments using fossil Platanites from the San Juan Basin, New Mexico, and its implications for stomatal pCO2 reconstructions.
No full textIn the last two decades, stomatal proxies have been extensively used to reconstruct the concentrations of paleoatmospheric CO2 (pCO2) based on the well-established negative correlation between stomatal density (SD) and pCO2. However, various light environments within a fossil flora, known to influence many plant traits, including SD, were rarely discussed in most previous pCO2 reconstructions. We collected one well-preserved early Paleocene flora from the San Juan Basin, New Mexico, that is dominated by Platanites. We then analyzed the light environment of this flora based on leaf epidermal cell wall undulations, quantified by undulation index (UI), and the range of leaf carbon isotope. We found a negative correlation between UI and SD, which indicates that leaves under higher light intensities produce higher SD. Importantly, we observed a positive correlation between UI and reconstructed pCO2 using a leaf gas-exchange model, and we recommend future pCO2 reconstructions using stomatal proxies also assess variations caused by canopy light environments
Mindfulness-based program effectiveness on high school student hope, engagement, and academic achievement in the western United States : a quantitative examination.
No full textThe mental health crisis is on the rise, and adolescents are reporting higher levels of anxiety and depression. High school students' academic achievement, engagement, and hope for goal attainment are decreasing due to their mental health. The purpose of this study is to examine the effectiveness of mindfulness-based programs (MBPs) on high school students' academic achievement, classroom engagement, and hope. The theory used in this quantitative study is Snyder's (1995) hope theory, which focuses on the importance of hope in achieving goals and overcoming obstacles through motivation and adaptability. This quantitative quasi-experimental study investigates the effectiveness of MBPs on high school student academics, engagement, and hope. Through purposeful convenience sampling, two groups of high school students (n = 30) participated in the research. The participants' ages ranged from 15–17, with 46.67% identifying as male (n = 14), 50% identifying as female (n = 15), and 6.67% identifying as nonbinary (n = 1). The experimental group participated in an MBP intervention facilitated by a trained teacher. The control group received no intervention for comparison. Academic grades, Mindful Attention Awareness Scale, and Children's Hope Scale scores were collected for pre- and post-test comparisons. This study revealed that students who participated in an MBP had a higher median grade average than those who did not. However, after MBP implementation, students showed a 4% increase in grade percentage. Although not statistically significant, there was a medium effect size (d = .36), which shows practical significance for the experimental group (n = 14). Additionally, this study shows that MBPs have no impact on classroom engagement or on student hope. This study has implications for school districts, administration, and teachers to combat declining student mental well-being. With the rise of anxiety and depression among students, interventions within the education system are needed to provide students with the skills to regulate their emotions in a positive way. Mindfulness allows students to ground themselves in the present moment toward academic success and hope for a positive future
A Race Against Time : Examining the Role of Donor Liver Quality in High-Risk Liver Transplant Patients
No full textHigh-acuity liver failure patients have gained more access to donated livers due to historically high waitlist mortality rates. While most research suggests that donor liver quality has little impact on outcomes for high-acuity patients, recent studies show some inconsistencies in how liver quality affects post-transplant results. This study aims to quantify the effect of donor liver quality on seven post-transplant outcomes for patients with MELD scores above 35: patient mortality, graft failure, length of hospitalization, long-term survivor mortality, non-status 1A mortality, non-HCC mortality, and primary non-function. Using the Liver Donor Risk Index (LDRI), Model for End-Stage Liver Disease (MELD), and relevant recipient factors, we performed multivariate logistic regression to evaluate these outcomes in 9,923 high-acuity patients from June 18, 2013 to June 18, 2022. Results showed donor liver quality significantly impacted five of the seven outcomes, with no significant effect on long-term survivor mortality and primary non-function. Our findings indicate that further research, including intent-to-treat analyses and broader transplantation practices, is needed to clarify the relationship between donor quality and outcomes for high-acuity patients
An NLP Interface for Social AI Agents in The Resistance : Avalon
No full textSocial deduction games such as Avalon present a unique challenge for AI agents. To discover the hidden roles of others, players must employ indirectness and deception in their communication. DeepRole, an Avalon-playing AI agent created by MIT researchers in 2019, can communicate through in-game actions but is unable to communicate in natural language. We have created Avalocution, a bot that enhances DeepRole with one-way bot-to-human natural language utterances informed by DeepRole's internal knowledge representation. We hypothesized that our natural language interface would produce direct and indirect communication, exhibit human-like behavior, and provide a positive gameplay experience for human players. We collected survey data from research participants who played Avalon against Avalocution agents, and the survey data supports our hypotheses. We conclude that adding Avalocution's simple one-way utterance generation model to DeepRole's existing decision-making framework captures the nuance of communication required in Avalon while providing an excellent gameplay experience