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Therapeutic Potential of Astrocyte-Derived Extracellular Vesicles in Mitigating Cytotoxicity and Transcriptome Changes in Human Brain Endothelial Cells
Full text linkExtracellular vesicles (EVs) play a major role in cell-to-cell communication via the horizontal transfer of RNA, DNA, proteins, and lipids that affect the physiological response of the recipient cells. Astrocytes are a type of glial cell that exerts a protective effect on neurons and brain endothelial cells. The astrocytes and the endothelial cells form the blood-brain barrier. Due to their nano-size and non-complex structure, EVs can efficiently cross the blood-brain barrier. This study investigated and assessed the impact of EVs on reducing oxidative DNA damage in human brain endothelial cells (HBECs). The protective potential of astrocyte-derived EVs was determined by assessing the changes in nuclear 8-OHdG concentration and OGG1 mRNA levels in HBECs treated with sodium dichromate to induce oxidative DNA damage. Exposure to sodium dichromate for 5 and 16 hours induced oxidative DNA damage, as reflected in increased genomic 8-OHdG levels, while the EVs mitigated the accumulation of the adduct, reducing the levels to the normal physiology range. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to assess the gene expression levels of OGG1, an enzyme involved in the excision of the 8-OHdG adducts. A neurotoxic environment caused an upregulation of the DNA repair enzyme OGG1 in HBECs while the astrocyte-derived EVs reduced its expression. An MTT assay, conducted to evaluate cell proliferation and cytotoxicity, revealed that EVs were associated with increased cell proliferation and reduced cytotoxicity in sodium dichromate-treated cells. Mito Tracker Green fluorescent analyses were performed to evaluate the impact of EVs on mitochondrial mass and copy numbers in human brain endothelial cells exposed to oxidative stress. Previous studies indicate that oxidative stress leads to increased mitochondrial mass, decreased oxidative activity, and reduced mtDNA copy numbers in the cells.[1] Mitochondrial dysfunction, including reduced copy number and circular morphology induced by neurotoxic exposure, was reversed by astrocyte-derived EVs, leading to elongated and interconnected mitochondria. High-throughput RNA sequencing revealed that exposure to sodium dichromate without EVs suppressed immune response genes. The addition of astrocyte-derived EVs resulted in the dysregulation of long noncoding RNAs impacting genes associated with brain development and angiogenesis. These findings reveal the positive impact of astrocyte-derived EVs in mitigating neurotoxicity and as potential therapeutic avenues for neurodegenerative diseases
The Quatrain - Volume 7
Full text linkThe Quatrain is managed by students at Louisiana Tech University and advised by faculty from the College of Liberal Arts. The journal is housed in George T. Madison Hall, where undergraduates collect, assess, and edit submissions from student writers and artists.
The Quatrain is a print and electronic project for people who value quality undergraduate writing and art. Full-dress researched, academic essays and scholarly explorations; photography; life-writing; sculpture; cultural criticism; work that has a reflective, autobiographical style; and creative writing in all its forms: We simply seek to display samples of the interesting, original, and quality work being produced by gifted students and emerging talents.
Visit us at thequatrain.com to learn more
Barriers to Gluten-Free Diet Adherence and How They Relate to Quality of Life and Self-Efficacy in College Students with Celiac Disease
Full text linkCeliac disease (CD) is a chronic, autoimmune disorder with an increasing global prevalence. As the only current treatment is a strict gluten-free diet (GFD), adherence is imperative to maintain optimal health in individuals with the disease. There are many potential barriers to GFD adherence, including social, mental, and financial difficulties. College also presents a unique set of challenges for students with CD that may not be experienced by those without the disease. The purpose of this study was to determine the potential barriers to GFD adherence experienced by college students with celiac disease in the United States. This study also explored the relationships between GFD adherence, health-related quality of life (HRQOL), self-efficacy (SE), grade point average (GPA), and registered dietitian nutritionist (RDN) diet education. This descriptive, exploratory study utilized a cross-sectional, electronic survey design with a network sampling technique. The questionnaire included items from the Celiac Dietary Adherence Test (CDAT), the Health-Related Quality of Life Scale (HRQOL-14), the Celiac Disease Self-Efficacy Scale (CD-SE), researcher-developed questions, and demographic data. Participant eligibility criteria included physiciandiagnosed CD, age of 18 years or older, current enrollment in a college or university in the United States, and ability to read English. Those who completed the questionnaire were eligible to enter a gift card raffle. Responses from 78 participants were used for analysis. The majority of students were White, non-Hispanic (83.3%) females (70.5%) between the ages of 18-38 years old (M = 22.4, SD = 4.5). The majority of participants reported having a meal plan (70.5%), having past GFD education with an RDN (55.7%), and having an additional food allergy (65.8%). Mean GPA (n = 65) was 3.4 (SD = 0.76). The mean CDAT score for participants (n = 75) was 16.3 (SD = 4.9), indicating overall good diet adherence. HRQOL was determined by the total number of healthy days reported by participants in a 30-day window. The mean number of healthy days experienced by 74 participants was 13.3 (SD = 9.6) indicating less than half of all days to be healthy. The mean total score was 6.2 (SD = 1.2), indicating overall low SE. Participants showed the highest average SE in the Shopping subcategory (M = 7.0, SD = 1.8) with the lowest mean in the Work and Studies (M = 5.5, SD = 1.7) subcategory. Dietary adherence measured by CDAT scores was significantly, negatively correlated to total healthy days, r(72) = -.38, p \u3c .001, and CD-SE scores r(62) = -.49, p \u3c .001. Total healthy days and CD-SE scores were significantly, positively correlated, r(62) = .28, p = .03. There was no significant relationship found between GPA, CDAT scores, total healthy days, and CD-SE scores. Years since diagnosis was significantly, positively correlated to CD-SE scores, r(62) = .26, p = .04. A significant, negative relationship was found between past GFD education from an RDN and self-efficacy in the CD-SE travel subcategory only, t(61) = -2.93, p = .005. When compared to students without RDN diet education, students with RDN experience had lower travel SE scores. Confidence in GFD knowledge was significantly, negatively related to CDAT scores, t(65) = -.33, p \u3c .001, indicating confident participants had greater diet adherence. No significant relationships were found between ownership of a meal plan with CDAT scores, total healthy days, and CD-SE scores. Regression analysis found that RDN counseling, years since diagnosis, and total CD-SE scores were able to significantly predict diet adherence measured by CDAT scores, R2 = .234, F(3,58) = 5.92, p = .001. Total mean CD-SE scores significantly predicted diet adherence, ß = -2.08, p \u3c .001. Regression analysis found that CDAT scores, years since diagnosis, question five of the HRQOL-14, and RDN counseling were able to significantly predict HRQOL measured in total healthy days, R2 = .195, F(4,62) = 3.75, p = .009. CDAT scores significantly predicted the number of total healthy days ß = -.604, p = .011. In response to the researcher-designed questions, the majority of participants reported feeling confident in their GFD knowledge (74.36%), feeling financially burdened (51.28%), feeling pressured in social situations (47.4%), and feeling additional barriers during college (61.54%). Some of the most reported additional barriers to adherence were navigating the campus dining halls, facing social pressures, finding food while traveling, and financially supporting the GFD. Prior to this study, there has been little research on this topic focused on a college population. The findings of this study suggest that GFD adherence is related to HRQOL and SE. By increasing SE among college students with CD, dietary adherence and subsequently HRQOL may be improved
Can Compiled Player WAR Predict MLB Team Win Percentage?
Full text linkThe baseball statistic Wins Above Replacement (WAR) is a complex yet effective metric for approximating the contribution of a player to his team through representing how many more wins his team ought to earn than with a AAAA player in his stead. The intent of this paper is to test whether the accumulation of player’s WAR can be extended to satisfy another discipline of SABRmetrics, i.e. predicting an entire team’s future performance, through modeling the sum’s correspondence (or lack thereof) to wins. If WAR is shown to extend in this way then franchise front offices could feasibly isolate it as a singular metric for team construction, rendering negligible the intangible elements of team chemistry which could theoretically surface when bunching individuals’ stats. Using numbers from the last 10 seasons of Major League Baseball, statistical methods are employed to aid in the above determination as well as to answer some ancillary questions, including, for instance, concluding the quality of bWAR vs. fWAR and WAR vs. WAA and offering an answer for the ’Y-Intercept Conjecture’
Abstract Measures on Totally Ordered Sets
Full text linkTwo specific notions of integration were the motivation of this paper: Riemann-Stieltjes and Lebesgue-Stieltjes integration. The question that arose from these notions was the idea of generalization. How can Stieltjes integration be generalized to an arbitrary measure? The buildup to this question requires a beautiful combination of measure theory and order theory to deliver a measure on totally ordered sets that provide structure for a potential generalization. This paper shows that the set of chains in a totally ordered set is a σ-algebra and defines cumulative cardinality measure on (X, Σ) in an attempt to give insight on the structure of a totally ordered set X as a measurable space
Experimental and Numerical Investigation of Droplet Dynamics in Microscale Systems: The Influence of Surfactants and Nanoparticles on Environmental Applications
Full text linkEmulsions are suspensions of droplets dispersed into an immiscible liquid phase, with at least a water phase and an oil phase. The capability to incorporate both hydrophilic and hydrophobic components makes emulsions amenable to a variety of applications, such as bilgewater treatment and oil recovery. To optimize bilgewater treatment or oil recovery, many aspects must be considered, such as the effect of emulsion stability, the wetting conditions and, more in general, the possibility to characterize droplet’s behavior over static or dynamic conditions. This thesis investigates the roles of surfactants and nanoparticles in understanding droplet behavior in oil-water systems, with a specific focus on bilge water treatment and enhanced oil recovery (EOR). The study aims to improve the efficiency of oil-water separation, a critical process for environmental protection in maritime settings and for maximizing oil extraction from underground reservoirs. The study begins with an analysis of the dynamic interfacial tension (IFT) behavior of two surfactants, Triton X-100 and Glucopon 225 DK, measured using the pendant drop method. The critical micelle concentrations (CMC) of these surfactants were determined, revealing that Triton X-100 has a significantly lower IFT compared to Glucopon 225 DK. In the next step, from the interfacial tension obtained during the experimental work, key adsorption parameters, including the maximum surface concentration (Γ∞) and the equilibrium constant (κ), were derived using the Langmuir adsorption isotherm. These parameters provide clear insight of surfactants characteristics and their role in separate of oil from water to provide cleanliness component. The second part of this study focuses on the dynamic role of silica nanoparticles in improving the wettability of surface to increase the extraction of oil from underground reservoirs to see their potential in altering reservoir rock wettability from strongly oil wet to water wet. Additionally, by using simulation the effect of various surface wettability on the droplet behavior was investigated by using COMSOL simulation. The results indicate that Glucopon 225 DK exhibits a higher surface coverage (Γ∞), meaning more surfactant molecules cover the droplet interface, while Triton X-100 shows a higher affinity (κ) for the oil-water interface and greater diffusivity. From studying nanoparticle impact on improving surface wettability, it was observed that even small amount of SiO2 nanoparticle can increase the hydrophilicity of the surface and make the surface more favorable for oil recovery industry. From the COMSOL simulation, it was observed that how wettability of surface can change the droplet behavior. At complete oil wet surface, the oil droplet can get stuck to the surface or undergo breakup or deformation. However, by altering the surface to more hydrophilic, the oil droplet can move smoothly which is favorable to extraction of oil. The significance of this study lies in its potential to prevent environmental pollution and oil extraction from existing wells before moving on to newly discovered fields. Despite the fact that the previous experimental work has focused on microscale droplets with insoluble surfactants, most of those studies focused on the systems that follow the Bancroft rule, where the surfactants are soluble in the continuous phase. Few of the seminal studies have performed experiments using soluble surfactants or surfactants inside droplets, which can be more relevant to some key applications, such as the treatment of bilgewater. However, in this study, the effect of surfactant in the dispersed phase is investigated. Also, in considering improving the surface wettability, the impact of high concentration of nanoparticle were observed statically. In this study, however, the temporal efficiency of dilute nanoparticles of SiO2 was investigated to see their potential in improving oil droplet movement in oil-water systems
Selective Targeting of Microglia by Quantum Dots and Green Synthesis of Metal Organic Biohybrids; Applications in Dynamic Cell and Assay Systems
Full text linkNeurological disorders are the leading cause of physical and cognitive disability across the globe, currently affecting approximately 15% of the worldwide population. Part of the glioma microenvironment are microglia, resident immune cells of the CNS that were thought to be involved in the pathogenesis of diverse neurodegenerative diseases. Though it remains uncertain what triggers microglial activation in these disorders, targeting and tracking microglial functions using nanotools like Quantum Dots (QDs) could help us elucidate them in such neurological diseases. This research focuses on the comparative study of different QDs formulations and their selective uptake by brain microglia in primary cultures of the mouse brain. The work is expected to explain the properties and characteristics of different Quantum Dots, helping choose the right ones for targeted microglial cell studies. This research also investigates the interaction and potential of the novel material Copper High Aspect Ratio Structures (CuHARS) and halloysite nanotubes (HNTs) with Human Dermal Fibroblasts (HDFs) in a dynamic wound healing model. Green synthesis of nanomaterials endeavors to reduce high-energy methods with those that may include lower temperatures and pressures, the use of natural products, and bottom-up self-assembly. Our lab has previously described the self-assembly of Metal-Organic Biohybrids (MOBs) with nano- and micro-scale features using copper and silver. Unique to our synthesis compared to many other nanomaterials, in this research, we generated copper and silver MOBs with nanoscale features at physiological temperature (37°C) and body temperature (27°C). This work also focuses on understanding the potential applications of these MOBs (CuHARS) in Lateral Flow Assay (LFA) systems applications
Corporate Social Responsibility Impact on Financial Performance: The Roles of Corporate Reputation and Engagement Patterns
Full text linkCorporate Social Responsibility (CSR) has garnered significant attention. Understanding the mechanisms through which stakeholders interpret a firm’s CSR efforts and the boundary conditions that affect the relationship between CSR and its outcomes can help companies optimize resource allocation to CSR activities. This research explores the link between CSR and financial performance, highlighting the mediating role of reputation and the moderating effects of different CSR engagement patterns. Drawing on cognitive literature, this study suggests that a firm’s consistently increasing investment in CSR activities can enhance corporate reputation, which in turn improves financial performance. The effect of different CSR engagement patterns on this relationship can be positive or negative, depending on how stakeholders perceive congruent or incongruent CSR information cues. Utilizing data from 269 firms and 1,763 observations between 2013 and 2019, the findings indicate that CSR boosts financial performance via corporate reputation when considering the conditional factors of various engagement patterns; without these factors, CSR efforts do not positively impact corporate reputation. The relationship between CSR and reputation is strengthened by increasing CSR engagement pattern and is slightly enhanced by constant engagement pattern, whereas it is weakened by decreasing or non-constant engagement patterns. Hence, this study applies cognitive literature from the perspective of stakeholder interpretation of CSR information to offer a new understanding of how CSR impacts financial performance and how to maintain such a positive relationship. For practical implications, managers and companies should focus on long-term, continuously improving CSR strategy that enhances competitive advantage and reputation, rather than concentrating solely on the short-term gains or losses of CSR activities
How Helpless Are You? The Need for Closure and the Need for Cognitive Preferences as a Moderating Effect in the Relationship Between Perceived Self-Efficacy and Learned Helplessness
Full text linkA substantial amount of research has been shown that the impact of self-efficacy has shown positive and negative effects. Additionally, the need for closure defined as an individual\u27s motivational degree to reach firm answers, as opposed to ambiguity has also been shown to have diverse effects for individuals when their closure needs are threatened or unobtained. Research has posited that to successfully obtain and/or avoid reaching closure in various situations, an individual must be able to process information in a way that is quick, heuristic, and stereotypical (e.g., cognitive structuring) or in a way that is much slower, effortful, and systematic (e.g., cognitive piecemeal). Processing information in either manner requires at the very least the belief or perceptual ability to satisfy closure goals. This is known as the Efficacy to Fulfill Closure Needs. The present study resulted in one significant hypothesis that supported the prediction that when individuals perceive themselves as incapable, a developed sense of learned helplessness arises where individuals think, feel, and act rather helpless in situations, despite the fact, that acting could otherwise result to different outcomes. The hypotheses that this relationship would moreover be significant when conducting two sets of moderations for Need for Closure and Need for Cognitive Structuring were found as insignificant. Still, the present study’s overall findings, limitations, and implications, revealed promising directions for future research in this area
Simulations, Modeling and Data Analysis of Parity Violating Electron Scattering Experiments
Full text linkIn the Standard Model (SM) of nuclear and particle physics, parity violation is incorporated through the representation of the weak interaction as a chiral gauge interaction. Only the left-handed components of particles and right-handed components of antiparticles participate in weak interactions in the Standard Model. This implies that parity is asymmetric for the weak interaction. Parity violating electron scattering (PVES) experiments are designed to probe the physics parameters related to the SM, with the possibility to discover physics beyond the SM (BSM) by measuring the parity violating asymmetry of longitudinally polarized electrons scattered off unpolarized targets with high precision. This dissertation will be focused on two PVES experiments, the next 208Pb Lead Radius Experiment (PREX-II), and the Measurement of a Lepton-Lepton Electroweak Reaction (MOLLER) experiment, as well as in some small sections, the Calcium Radius Experiment (CREX) and P2 experiment which are also PVES experiments). PREX-II and CREX experiments, performed in Hall A at the Thomas Jefferson National Accelerator Facility (Jefferson Lab), measured in the elastic scattering of longitudinally polarized electrons from 208Pb and 48Ca targets to provide a precise model independent determination of the neutron skin thickness of 208Pb and 48Ca nuclei, respectively. The MOLLER experiment, proposed to start in 2027 and also to be performed in Hall A at Jefferson Lab, is to measure of longitudinally polarized electrons scattered off unpolarized electrons (Møller scattering) to determine the weak charge of electrons and the weak mixing angle with high precision. As for the P2 experiment, which will be performed at the upcoming MESA accelerator in Mainz Germany, it is to measure the weak charge of proton using in the elastic electron-proton scattering of polarized electrons off unpolarized protons. The final results from the PREX-II experiment are presented as =550±16 ()±8 () parts-per-billion (ppb). Combining the PREX-I and PREX-II results, the neutron skin thickness from PREX experiments is determined as −=0.283±0.071 in 208Pb. This thesis lists the software and computational contribution of the author to these PVES experiments, including writing scripts and software to help with the PREX-II/CREX experiments, analyzing data to provide useful information and systematic uncertainty for the PREX-II experiment, modeling and simulations for the MOLLER, and providing an alternative design of an electronic equipment for the P2 experiment