6834 research outputs found
Sort by
An epigenetic and transcriptomic study of diapause formation in the mosquito Culex pipiens.
No full textCulex pipiens, the Northern house mosquito, is a major vector for pathogens including West Nile virus, Saint Louis encephalitis viruses, avian malaria, and filarial worms. To survive harsh winter conditions, Cx. pipiens enters adult diapause, a hormonally regulated dormant state characterized by unique phenotypic changes including arrested development, enhanced stress tolerance, lipid accumulation, and lifespan extension. While non-diapausing females typically live for about one month, diapausing females can survive for five months or more. Recent evidence has implicated epigenetic modifications as hallmarks of aging in various organisms. Our research explored the role of epigenetic regulation in Cx. pipiens diapause, focusing on histone H3 lysine 27 di- and trimethylation (H3K27me2/3) in the fat body. We found significantly lower levels of H3K27me2/3 in diapausing females compared to non-diapausing counterparts. Disruption of histone demethylase function interfered with key diapause features, including lipid accumulation and lifespan extension. Through RNA-seq analysis, we identified differentially expressed genes in both fat body and ovary tissues of diapausing mosquitoes, providing insights into tissue-specific transcriptional regulation during diapause. Additionally, ChIP-seq analysis characterized genetic targets of H3K27me3 in fat body cells of diapausing adult females. Collectively, our findings illuminate the regulatory networks underlying diverse diapause traits in Cx. pipiens, expanding our understanding of lifespan extension in diapausing mosquitoes and its connection to epigenetic modifications. This research provides insights into the discovery of regulatory networks during the diapause program that led to diverse diapause traits and may inform novel vector control strategies
Social inclusion through the use of information technology.
No full textSocial inclusion has attracted global attention, and nations have pledged to reduce global inequality as part of the 2030 Agenda. The term social inclusion is defined as “the process of improving the terms of participation in society for people who are less advantaged on the basis of age, sex, disability, race, ethnicity, origin, religion, or economic or other status, through enhanced opportunities, access to resources, voice and respect for rights” (Report on the World Social Situation, 2016). Information systems (IS) can enable or impede the social inclusion of such populations through the design of technologies. IS scholars have recognized the problem of social inclusion and investigated it in diverse contexts. Digital technologies have been viewed as the means of achieving social inclusion for various subpopulations, facilitating access to resources and helping them accomplish their goals through information technologies. While scholarship on social inclusion in information systems is often concerned with who should be included, less emphasis is placed on how they are included and what conditions enable inclusion. The goal of this dissertation is to provide answers to these questions by tapping into 1) the role of information technology in enabling social inclusion, and 2) the role of language used by less advantaged individuals through information technology for communicating their needs. In regard to each essay in this dissertation, I discuss the relevant theory, methodology, data sources (for empirical essays), results (for empirical essays), and implications. I conclude by highlighting the contributions of my work, and possible avenues for future research
Integrative modeling of genomic data for substance use risk prediction.
No full textSubstance use behaviors are complex traits that have been shown to be influenced by genetic factors. Understanding their genetic basis is crucial for identifying risk factors, uncovering biological mechanisms, and improving predictive models for substance use disorders (SUDs). This study employs a comprehensive approach that integrates genomic variant analysis, functional genomic annotations, and polygenic risk prediction to investigate the genetic contributions to substance use. First, a multi-ancestry analysis was conducted to identify and prioritize genetic variants associated with early alcohol and tobacco use. Using MultiGPATree, key genetic loci were identified and their biological significance assessed through gene and pathway enrichment analyses. In addition to variant prioritization, the study evaluated the predictive utility of polygenic risk scores (PRS) for substance use behaviors. PRS were generated using the SBayesRC method. To assess the impact of genetic information on prediction performance, we built unified multi-ancestry PRS to predict substance use behaviors and explored the relative contributions of variants annotated with different functional genomic annotations to better understand the genetic contributions to risk. By integrating genetic variant prioritization with predictive modeling, this study provides a framework to gain insights into the genetic mechanisms underlying substance use and evaluate the utility of PRS in risk prediction
The effect of menstruation on strength and force output in trained females.
No full textPurpose: In strength training understanding muscles and their response to exercise is knowledge needed for progress. This research purpose is to examine if there is a difference between strength and force output in trained women during the phases of the menstrual cycle. Methods: Nine (9) trained females performed max effort leg extensions, hamstring curls, and grip strength tests with their dominant leg and hand during the early follicular, late follicular, ovulation and mid luteal phases of the menstrual cycle. Friedmans test was used to determine if there was a significant difference between the phases. Conclusion: There is a significant difference (p>0.05) in force output of the quadricep in the ovulation phase showing there is a significant increase in quadricep force output during the ovulation phase of the menstrual cycle showing the mid luteal phase having the lowest force output of the quadriceps out of the 4 phases in trained females
Analysis of social determinant of health factors and access to care at federally qualified health centers associated with Latina cervical cancer screening.
No full textPublic health screening promotion and programming have led to increased use of valuable tools such as pap-tests that have ultimately led to increases in early detection of cervical cancer and decreases of cervical cancer mortality. Though these advancements have been vital to the field of public health, disparities still exist for certain subgroups of women, particularly racial/ethnic minorities such as Hispanic women. The purpose of this dissertation is to assess what specific factors are impactful to cervical cancer screening rates in the Hispanic women population, particularly considering social determinants of health and access to Federally Qualified Health Centers (FQHCs) and their association with cervical cancer screening (CCS). This dissertation took a mixed-methods explanatory design approach by utilizing qualitative findings to enrich quantitative findings. The quantitative portion of this dissertation indicated significant crude associations for the entire southwest region (AZ, CA, NM, TX) as well as for California and Texas in the association between distance to FQHCs and CCS for Zip Code Tabulation Areas (ZCTAs) of the southwestern U.S. When stratifying the models to High-Density Hispanic ZCTAs and Non-High-Density Hispanic ZCTAs and including additional SDoH variables, distance is not a significant predictor of CCS for many High-Density Hispanic ZCTAs but is for some Non-High-Density Hispanic areas, which may pose additional barriers for individuals living in non-Hispanic majority areas. In addition, the health insurance covariate was statistically significant in nearly all models. In the qualitative portion of this dissertation, Hispanic women shared their knowledge and experiences in association with CCS. Themes emerged highlighting knowledge gaps for Hispanic women regarding understanding CCS guidelines, fear regarding CCS, and insurance status/cost as a consistent barrier. Additional themes such as generational divides in mobile vs. physical clinics and distance willing to travel for CCS were also uncovered. The qualitative responses and quantitative models that include additional SDoH indicate this is a multifaceted and complex area of factors impacting CCS for Hispanic majority areas. This dissertation highlights the need for culturally relevant messaging and interventions and awareness of health centers that accept patients regardless of insurance status or ability to pay
The effects of nutrient dynamics, environmental conditions, and anthropogenic activity on phytoplankton biomass and community composition.
No full textNitrogen (N) and phosphorus (P) are primary limiting nutrients of phytoplankton biomass in freshwater ecosystems. This dissertation explores the influence of nutrient availability, environmental variables, and anthropogenic activity on phytoplankton biomass, community composition, and biodiversity in lakes. First, we quantified phytoplankton nutrient limitation status and physiological response to seasonally changing nutrient availability in a mesotrophic human-made lake. We observed a seasonal shift from P limitation to N and P co-limitation and a transition in phytoplankton physiological response from N assimilation and transport to synthesis and fixation. This study was the first to formalize and test the nitrate drawdown hypothesis, highlighting nitrate drawdown effects on phytoplankton and its implications for dual nutrient control in lakes. Next, we explored the effects of geospatial and physiochemical variables on the spatial distribution and biodiversity of phytoplankton communities in lakes across the State of Oklahoma. Overall, we found that physiochemical variables are more predictive of variation in community composition than geospatial variables, highlighting the importance of in-lake characteristics when developing management strategies for maintaining clear water lakes and sustaining diverse lake ecosystems. Finally, we examined the independent and interactive effects of N form, N concentration, and micronutrient concentration on phytoplankton biomass in lakes along a eutrophication gradient. We observed independent and interactive effects of all three variables on phytoplankton biomass across seasons and lakes, with the most productive lakes responding more strongly to changes in N supply. We also found that adding N and P together resulted in a stronger response than when added singly, suggesting N and P co-limited conditions in several of the lakes. Together, these studies provide insight into the numerous multi-scale variables and biogeochemical processes that impact phytoplankton growth, community composition, and biodiversity. Since phytoplankton are often used as key indicators of ecosystem health and lake water quality, understanding the role that biological and anthropogenic activity play in structuring phytoplankton communities is key to maintaining stable ecosystems
Hydropower modes of operation and methane : a scoping review of research practices and a framework for future study.
No full textHydropower is widely regarded as a carbon-neutral alternative to fossil-fuel based electricity. However, emerging research indicates that hydropower reservoirs can emit notable amounts of methane, a potent greenhouse gas, through anaerobic decomposition of organic matter in anoxic conditions. It has been found that methane generation in reservoirs is influenced by geographic and environmental factors, but there is a significant research gap in studying the effect of hydropower operational modes on emissions. This thesis conducts a rapid scoping review of existing literature to assess how methane emissions research is currently performed regarding hydropower operational modes. It addresses the representation of operational modes, identifies inconsistencies in methodology, and assesses the geographic and temporal variation in studies. Findings reveal significant differences in study design, site comparability, as well as data reporting. This complicates cross-study synthesis, and limits understanding of operational impacts on methane dynamics. This review highlights the need for standardized replicated methodologies in order to strengthen future analyses. By evaluating how current research approaches methane emissions, this thesis establishes a framework for more consistent and comparable studies, ultimately supporting the development of hydropower systems that are both renewable and climate responsible
Cultural support for entrepreneurship and its impact on economic development from 2019 to 2025 : a quantitative analysis based on the Global Entrepreneurship Index.
No full textCultural support for entrepreneurship in the form of individual and institutional support has been a key area of study for scholars in recent years. Given the profound impacts of cultural support on entrepreneurial intentions and the lack of quantitative analysis using up-to-date data, the study of cultural support for entrepreneurship as it pertains to development applications is more crucial than ever. This paper recreates a dimension of the discontinued Global Entrepreneurship Index, arguably one of the foremost sources for entrepreneurship research, and extends it using the most recent data. The resulting findings provide country-level changes in cultural support from 2019-2025 and imply that overall cultural support has declined during this time period. These results are then presented in the context of several case studies that provide insight into the issues faced by developing countries
Underrepresented in accounting : a qualitative single case study on the self-efficacy and outcome expectations of Black CPAs to explore their career self-management.
No full textBlack Certified Public Accountants (CPAs) have traditionally been and continue to be underrepresented in accounting (T. A. Hammond, 2002; Tamir et al., 2021; Weisenfeld & Robinson-Backmon, 2001). Blacks make up 1% of CPAs in the United States and hold significantly fewer leadership and partnership positions in accounting firms (Mhute, 2021; Smith, 2021). The central research question for this study focused on how Black CPAs' adaptive career decisions have impacted their career self-management to earn CPA licensure. The purpose of this qualitative single case study was to explore and describe the experiences of Black CPAs and their adaptive career decisions through the lens of social cognitive career theory (SCCT) to explain the low number of Black CPAs (Lent et al., 1994, 2000; Lent & Brown, 2013). I utilized SCCT career self-management as the theoretical framework for this qualitative single case study. SCCT career self-management establishes that an individual's personality, contextual influences, self-efficacy, and outcome expectations interact to inform their interests, choice, performance, and satisfaction (Lent et al., 1994; Lent & Brown, 2013). This study featured three data sources to describe, triangulate, and analyze Black CPA experiences. Data were collected from a cross-section of 16 participants from 11 states using questionnaires and semi-structured interviews, which featured six participants who also participated in a focus group discussion. All participants in the study were members of the 1% Black CPAs. The study found that Black CPAs' adaptive career decisions impacted their career self-management to acquire CPA licensure. The research findings indicated that Black accountants' positive learning experiences, such as having access to mentors, enhanced their confidence and outcome expectations, which enabled them to apply adaptive behaviors toward their CPA licensure process. The three themes that surfaced—exposure, support, and assertiveness—encapsulated the variables that the participants considered most influential in shaping their self-efficacy and anticipated outcomes regarding CPA licensure. The research findings highlighted implications for primary and secondary target audiences engaged in the CPA licensure process, which includes Black students and professionals, academic institutions (including high schools), and CPA firms as well as other hiring organizations
Advancing the characterization of glycan dynamics with in-electrospray ionization hydrogen/deuterium exchange-mass spectrometry.
No full textGlycans are biomolecules that have various essential roles in human health and disease. Carbohydrates are composed of isomeric features ranging from differences in composition, linkage, and configuration, resulting in complex and branched molecules. The structural diversity of carbohydrates influences their biological functions. Although various analytical techniques exist to study carbohydrates, mass spectrometry (MS) remains one of the most widely used methods because it provides structural information. Hydrogen/deuterium exchange (HDX-MS) is a labeling technique that monitors the exchanging labile hydrogen atoms for molecules across different timepoints. Traditionally, HDX-MS has been used to study protein structure and dynamics; however, this deuterium labeling method has become an emerging technique to study carbohydrates. The hydroxyl groups in carbohydrate structures exchange rapidly, resulting in limitations for traditional HDX when analyzing carbohydrates. In-electrospray ionization (in-ESI HDX-MS) enables rapid labeling and can be applied to study the solvated states of metal-adducted carbohydrates. The goal of this work is to develop in-ESI HDX-MS methods to study carbohydrate dynamics and structures. In Chapter 2, ESI droplet sizes and lifetimes are altered which changes the HDX reaction time, and thereby produces different magnitudes of HDX. The dynamics of solvated carbohydrates are monitored and are demonstrated to influence HDX. In Chapter 3, HX-Express, an HDX data analysis software, is used to interpret rapid in-ESI HDX data for several analytes, including a peptide, carbohydrates, and a glycopeptide. This work demonstrates a way to analyze complex spectral data resulting from different types of protonated and/or sodiated and potassiated adducts. In Chapter 4, the repeatability of in-ESI HDX using different-sized tips is validated to improve in-ESI HDX methods for carbohydrate studies. Collectively, this work facilitates the development of in-ESI HDX-MS methods to characterize the dynamics and structures of carbohydrate isomers