The University of Texas at Tyler
Scholar Works at UT Tyler (University of Texas at Tyler)Not a member yet
5042 research outputs found
Sort by
USING VEGETATION COMMUNITIES TO COMPARE NATURAL AND CONSTRUCTED WETLANDS IN THE RED RIVER BASIN IN TEXAS AND LOUISIANA
Full text linkWetland vegetation provides an abundance of ecosystem services such as water quality regulation, flood control, and it provides habitat space for fish, amphibians, and macroinvertebrates. Not only that, but these plants also act as excellent indicators of wetland conditions as dominant vegetation types are often used as biological criteria for classifying wetlands and other habitats (Cowardin and Golet, 1995). This project will assess the structure of vegetation communities to determine how they differ in constructed and natural wetlands within the Red River drainage basin to see if Agricultural Conservation Easement Program – Wetland Reserve Easement (ACEP-WRE) constructed wetlands are effective mitigation options for restoring lost or damaged wetlands. Twenty-eight wetlands in northwestern Louisiana and northeastern Texas along the Red River basin were sampled, eight of which were naturally occurring wetlands used to establish a baseline of vegetation communities, and the remaining 20 were constructed wetlands used to draw a comparison between the structure and function of both wetland types. Using a series of tests to analyze community composition, wetland indicator status and Floristic Quality Assessment of the vegetation communities in each wetland, comparisons could be drawn between the different wetland types. The results of these tests indicate that the natural and constructed wetlands sampled in this study show no significant differences in vegetation community quality or wetland indicator status. Future research should vibe done to determine if similar environmental variables, such as soil chemistry and hydrology, are influencing these vegetation communities to share similar compositions and how these community compositions change over long periods of time
MODULATION OF PULMONARY EPITHELIAL PARACELLULAR PERMEABILITY BY PNEUMOLYSIN FROM STREPTOCOCCUS PNEUMONIAE
Full text linkPneumolysin (PLY), a key virulence factor of Streptococcus pneumoniae (S. pneumoniae), disrupts airway epithelial barriers, yet its cellular and molecular mechanisms remain poorly understood. We aim to elucidate recombinant pneumolysin (rPLY)’s effects on Calu-3 bronchial epithelial barrier integrity and underlying pathways. This study investigates the effects of non-lytic and lytic PLY concentrations (5, 15, 30 µg/mL) to test the hypothesis that PLY increases epithelial paracellular permeability by affecting the anatomy and physiology of epithelial tight junctions. To address the hypothesis that PLY increases paracellular permeability through disruption of tight junction integrity in Calu-3 cells in a time- and dose-dependent manner, genomic DNA was isolated from virulent S. pneumoniae strain D39, and specific regions were amplified using PCR. The amplified DNA was ligated into the pET28b plasmid, and Escherichia coli (E. coli) BL21 cells were transformed to support the recombinant vector and produce a viable pneumolysin product. The PLY protein was purified via FPLC-NGC and further purified via the De-Salting column. Analysis by SDS-PAGE revealed a final product of ~53 kDa, corresponding to the molecular weight of the natural pneumolysin. The non- lethal concentration of the purified recombinant protein was determined via LDH assay. Confluent monolayers of Calu-3 cell line were cultured on porous membrane inserts and used to investigate PLY\u27s impact on epithelial paracellular permeability. Transepithelial electrical resistance (TEER) was used to evaluate the integrity of epithelial junctional complexes. The TEER data revealed a significant reduction in resistance post-PLY exposure with various concentrations of PLY (5, 15, and 30 µg/mL) for up to 50 minutes. TEER data indicated a significant decrease in epithelial resistance at 50 minutes for the highest concentration (Triplicate inserts, 4 independent experiments, t-test, p\u3c 0.01), indicating a compromised barrier integrity. Fluorescence microscopy images indicated subtle alterations in the expression and localization of the tight junction protein occludin. In conclusion, our data revealed the potential mechanism of S. pneumoniae-induced pulmonary injury at the cellular level
DNP Final Report: Improving Adherence with CMS SEP-1 Sepsis Bundle in the Emergency Department
Full text linkAdherence to the CMS SEP-1 Sepsis bundles is critical to sepsis management and leads to lower sepsis mortality, lower incidence of readmission, reduced length of hospital stay, and improved patient outcomes. This medical center has struggled to meet the required 71% adherence rate set by the Center for Medicaid and Medicare, representing the benchmark of acceptable care of sepsis patients. Therefore, the following PICOT question arises: among the hospitals’ ED physicians and nursing staff (P), how does a multimodal approach consisting of education, visual reminders, and audit and feedback (I) compared to a single approach (education) (C) affect adherence to sepsis protocol (O) within six months (T)? A comprehensive review of literature was conducted using CINAHL, PubMed, Medline, the Cochrane Database of Systematic Reviews (CDSR), Scopus, and ProQuest to review various interventions that improved adherence to SEP-1 in the emergency department. The interventions implemented for this project were a multi-modal approach that included the use of visual reminders (one-pagers and informational sheets highlighting often missed necessary steps in sepsis care), education, and audit and feedback. The evidence from literature suggested that implementing these interventions will improve adherence to SEP-1 bundles. The outcome result showed an improvement in adherence rate from 62% pre-implementation to 76% during implementation and 82% post-implementation. This EBP project has led to significant improvement in adherence to SEP-1 sepsis protocol beyond the implementation period and integration of the interventions into the daily workflow at the clinical site
WORK-LIFE BALANCE OF WORKING PROFESSIONALS ENROLLED IN A DOCTORAL DEGREE PROGRAM DURING COVID-19: A PHENOMENOLOGICAL STUDY
No full textThe purpose of this phenomenological study was to understand how working professionals enrolled in a doctoral degree program experienced work-life balance during the COVID-19 pandemic and to provide implications for human resource development (HRD) research and practice. Two research questions guided this inquiry: 1) How do working professionals enrolled in a doctoral program experience their work-life balance during a pandemic, and 2) How do working professionals enrolled in a doctoral program cope with challenges they experience in work-life balance during a pandemic? I conducted 11 semi-structured participant interviews who were working professionals enrolled in a doctoral program during the COVID-19 pandemic to answer the two research questions. I then transcribed and coded all collected data and identified two themes and twelve subthemes. The first theme, work-life balance, consisted of eight subthemes including, 1) defining work-life balance, 2) struggles of academic and professional workload, 3) remote working and learning, 4) duality of parenting and educating, 5) role balancing, 6) well-being, 7) struggles of keeping a social connection, and 8) experienced job uncertainty. The second theme, coping mechanisms, consisted of four subthemes including, 1) motivation for a Ph.D., 2) grit and determination, 3) social support, and 4) engaging in activities. The study findings emphasize the need for HRD practitioners to support their employees by offering flexible workplace policies, incorporating fun social activities in the workplace to promote well-being, and supporting employee development through higher education incentives and programs. Future research is needed to better understand this phenomenon such as conducting mixed-methods studies to provide additional depth and qualitative longitudinal studies to assess changes in WLB experiences throughout the pandemic and post pandemic
PHOTONIC CRYSTAL-BASED HYPERSPECTRAL IMAGING FOR IN VIVO SENSING AND ENDOSCOPY APPLICATIONS
No full textPhotonic crystal slab sensors are extensively researched for label-free detection due to their sensitivity to changes in the refractive index of surrounding media. However, their application in imaging and endoscopy remains relatively underexplored. This thesis introduces a novel approach to endoscopic technology by designing a photonic crystal slab-based spectral sensor that can be incorporated at the tip of an endoscopic probe. The system incorporates hyperspectral imaging to analyze the optical properties of targeted biological or agricultural tissues in real time. In biomedical diagnostics, it can aid in the early detection of diseases, including the identification of cancer cells. In agriculture, it allows for non-invasive imaging of plant roots to identify plant disease conditions, root-microbial interactions, nutrient uptake, etc. What makes this sensor unique is its ability to capture the reflection spectrum from biological tissues and reconstruct it into detailed spectral mapping for further analysis. The photonic crystal slab itself is highly miniaturized—measuring 34 µm × 34 µm—making it compatible with navigating narrow human arteries such as terminal arterioles, which are as small as 50 µm in diameter. To enhance its sensing capability, the design employs a 3×3 matrix of photonic crystal slab arrays, each with precisely engineered geometrical parameters such as periodicity and structural dimensions. These parameters determine the distinct spectral response of each array. The reflection spectra collected from these arrays are processed through an image reconstruction algorithm to create detailed spectral maps. Simulations of the sensor in a gastrointestinal environment were conducted using COMSOL Multiphysics 5.6. Results revealed that cancer cells exhibit higher light absorption in the visible spectrum range (400 nm to 700 nm) than normal cells due to their higher refractive index, providing a basis for distinguishing between healthy and cancerous tissues. For agricultural applications, the photonic crystal-equipped endoscopic probe is capable of reaching root zones as narrow as 0.04 mm, enabling simultaneous collection of spectral and visual data from delicate plant root areas, which are difficult to reach otherwise. This capability supports early disease detection, stress assessment, and evaluation of nutrient uptake in plants. In conclusion, the integration of a photonic crystal slab-based spectral sensor into an endoscopic system marks a significant advancement for both biomedical diagnostics and precision agriculture. Future developments will focus on physical implementation of this technology for widespread use in clinical and agricultural applications
Engineering HIV-1 Env protein to elucidate in situ structural dynamics of Env
Full text linkThe HIV-1 Envelope (Env) glycoprotein trimers undergo structural changes upon interacting with host receptor CD4 and coreceptors (CCR5/CXCR4) for virus entry. As the only surface-exposed viral protein, Env is a key antibody target but evades recognition through structural changes. Studying Env dynamics with respect to the coreceptor binding region (V3 loop) provides insights into virus entry and immune evasion. Fluorescence labeling via genetic code expansion (amber–TAG suppression) offers a minimally invasive approach for fluorescence microscope-based Env dynamics studies. Here, two V3-related dual-amber Env constructs (A135TAG-P308TAG, P308TAG-E395TAG) were generated by incorporating two non-canonical amino acids (ncAAs) at consecutive amber codons in Env on virions. Infectivity and immunoblotting showed 10-15% amber suppression efficiency, successful Env expression, and incorporation on virions that exhibit wildtype-like virion particle size. Our results pave the way for attaching two fluorophores to dual ncAAs incorporated in viral Env via click-chemistry, enabling structural dynamics from the V3 perspective
ROLE OF HDAC1 IN TYPE I IFN PRODUCTION BY MACROPHAGES AND DENDRITIC CELLS IN RESPONSE TO TLR3 STIMULATION AND MYCOBACTERIUM TUBERCULOSIS INFECTION
Full text linkIn this study we explored the role of histone deacetylases (HDACs), a group of epigenetic regulators, in production of type I interferon (IFN) by macrophages and dendritic cells (DCs) in response Mycobacterium tuberculosis (Mtb) infection and Poly I:C, a viral RNA mimic, stimulation. Human monocyte derived macrophages (MDMs) and DCs (MDDCs) stimulated with either Poly I:C or infected with Mtb produced elevated IFN-β and this was inhibited both at the protein and mRNA levels by 4-(dimethyl amino)-N-[6-(hydroxyamino)-6-oxohexyl]-benzamide (DHOB) and CAY10603 (CAY), chemical inhibitors targeting HDAC1. This was further supported by THP1-derived macrophages with HDAC1 knockdown producing reduced IFN-β in response to PMA stimulation or Mtb infection compared to their control cells. Inhibition of HDAC1 with DHOB and CAY reduced phosphorylation of IRF3, a major transcription factor of IFN-β. We conclude that HDAC1 is required for type I IFN production by innate immune cells in response to Mtb infection
Characterization of Immunogenicity of HIV mRNA vaccine in Humanized mice
Full text linkHuman Immunodeficiency Virus (HIV) remains a leading global cause of mortality. Despite decades of research, a definitive cure or an effective vaccine for HIV infection has yet to be discovered. The major target for HIV vaccine development is the envelope (Env) trimeric protein that is responsible for host cell attachment and fusion. This comprises gp120 and the transmembrane gp41. Gp140, a truncated form of gp160(full envelope trimer) lacks the transmembrane and cytoplasmic domains of gp41, closely mimics the native HIV envelope has been shown to enhance the induction of broadly neutralizing antibodies (BnAbs) when used as protein vaccine in previous studies. We thus hypothesize that an HIV mRNA vaccine carrying the gp140 mRNA sequence can induce robust antibody response in humanized mice. To test this, we generated HIV mRNA vaccine, characterized the uptake and expression in cell culture, and evaluated its immunogenicity and protective efficacy in vaccinated humanized mice challenged with HIV. The results show that the HIV GP140 mRNA-LNP vaccine was efficiently delivered and expressed in 293 T cells and human monocytes-derived dendritic cells. However, the vaccination could not elicit significant GP140- specific IgG and IgM antibodies or any neutralizing antibodies, and did not reduce viral load post-challenge. Nevertheless, the HIV GP140 mRNA-LNP seems to be able to provide partial protection by maintaining the normal level of CD4+ T cells. Our newly developed humanized mouse model offers a versatile platform for HIV vaccines candidates, while the HIV gp140 mRNA introduces an innovative strategy for HIV vaccine development
REGULATION OF INTERLEUKIN-8 (IL-8) GENE EXPRESSION BY BACTERIAL EXTRACELLULAR VESICLES ISOLATED FROM ORGANIC DUST IN THE HUMAN HMC3 MICROGLIAL CELL LINE
Full text linkExposure to the agricultural environment appears to be a risk factor for Parkinson’s and Alzheimer’s diseases, and dementia. Inhalation of agricultural dust may cause brain inflammation, leading to the development of neurological diseases. We studied the effects of poultry farm dust derived bacterial extracellular vesicles (EVs) (dust EVs) on the regulation of interleukin (IL)-8 expression in the human HMC3 microglial cell line. IL-8 dysregulation has been implicated in several neurological diseases. Microglial cells are brain resident immune cells that play major roles in immune and inflammatory responses. We found that treatment with dust EVs induced IL-8 expression at the transcriptional level via activation of NF-κB and STAT3 transcription factors. Chemical inhibitor and siRNA knockdown studies demonstrated that toll-like receptor (TLR)2 and TLR4 and enhanced intracellular reactive oxygen species (ROS) production by NADPH oxidases (NOX) mediate induction of IL-8 expression
NURSING STUDENTS AS ADVOCATES: ADDRESSING SOCIAL DETERMINANTS OF HEALTH THROUGH SERVICE-LEARNING
No full textAdvocacy is at the heart of nursing practice, and advocating for the social determinants of health (SDOH) is crucial when providing care to patients from vulnerable populations. Service-learning is a strategy that can be used to teach students advocacy skills. Chapter 2 of this dissertation portfolio presents a concept analysis that explores the definition of advocacy using the Walker and Avant method (2019). The concept analysis informed the development of the case study presented in Chapter 3 and the research study presented in Chapter 4. The portfolio includes original, qualitative research that was guided by the interpretive descriptive method. The aim of the study was to explore the impact of service-learning experiences on nurses’ ability to advocate for SDOH in vulnerable populations. Participants were divided into two groups: one group participated in service-learning while the other group did not have a service-learning experience. Interviews explored participants’ nursing care for patients from vulnerable populations and included reflections on the case study. Certain findings were consistent with published literature while other findings provided new insights. Unique findings included service-learning participants’ responses regarding structural conflicts related to SDOH and examples of creative strategies to address SDOH. Service-learning participants also approached nursing care from a more trauma-informed, person-centered perspective than the non-service-learning group and exhibited greater sensitivity to vulnerable populations