Life Sciences Commons^™

Cytochrome C: A Potential Early Biomarker Of Diabetic Retinopathy, Ileana G. Villarreal

Theses and Dissertations

Diabetic retinopathy is an ocular disease which appears in patients who experience progression of diabetes mellitus over a continuous period. Oftentimes, patients go undiagnosed due to the fact that there is no way to determine when the exact moment a patient develops diabetic retinopathy. Ophthalmologists and other eye specialists diagnose a patient with diabetic retinopathy once the patient begins to show progressed symptoms of the disease. Various experiments have been previously performed to increase our knowledge of the connection of diabetic retinopathy and early biomarkers of the disease. Several studies have determined the effects of diabetic retinopathy and apoptosis with …

Tree Ring Reconstructions Of Streamflow For The Lower Rio Grande Valley Of Texas, Adedolapo Mutiyat Adeyanju

Theses and Dissertations

The Rio Grande River is a major water source for people living within the USA-Mexico border. The Rio Grande River has its headwaters in the San Juan Mountains in Colorado and the Sierra Madre Occidental in Mexico before flowing into Texas through El-Paso. The water supply issues facing the Lower Rio Grande Basin (LRGB) are extremely complex from international restrictions to severe climate change. The river shares its flow between the U.S.A and Mexico based on the provisions of the 1944 treaty between the U.S.A and Mexico. The LRGB flow is regulated by releases from Falcon and Amistad Reservoirs managed …

Quantifying And Predicting Drought Performance In Woody Semi-Arid Seedlings In South Texas: Implications For Enhancing Drought Resilience In Restoration, Zarek Contreras

Theses and Dissertations

Increasingly frequent and severe droughts in the Lower Rio Grande Valley National Wildlife Refuge have been observed to cause large variation in species-specific mortality patterns in young seedlings, spanning 6 – 43 % mortality within the first year. To understand the underlying mechanisms behind this, we subjected seedlings of five woody semi-arid species (Celtis pallida, Forestiera angustifolia, Sideroxylon celastrinum, Phaulothalmnus spinescens, and Zanthoxylum fagara) to a point-of-no-return drought experiment in order to (1) identify potential metrics capable of predicting species wilting and mortality responses, and (2) to understand the underlying mechanisms that correspond to species drought performance …

Body Composition, Muscular Strength, Arterial Stiffness, And Hemodynamics Responses To Various Training Protocols In Young Males, Jorge Bejar

Theses and Dissertations

PURPOSE: The purpose of this study was to compare the effects of 8 weeks performing various resistance training protocols with and without blood flow restriction (BFR) on muscular strength, body composition, arterial elasticity, and hemodynamics responses in young males.

RESULTS: Significant time*condition interactions occurred in HR period (p <0.05), HDI SBP (p <0.05), HDI MAP (p <0.05), and SV (p <0.05). Trends for time*condition interactions were found in HDI DBP (p=0.054), HDI HR (p=0.051), and HDI SVR (p=0.085). Significant time main effects occurred in all strength measures (p <0.05). Significant condition main effects occurred in Aortic DBP (p <0.05), Brachial DBP (p <0.05), and LAE (p <0.05). Total lean mass significantly increased from baseline the HI condition only (p<0.05).

CONCLUSION: Significant improvements in lean mass were seen following the HI and BFR protocols. However, decreases in LAE were found following the HI protocol only. It appears that performing aerobic exercise after resistance training can negatively affect muscle growth. However, only 15 min of moderate-intensity aerobic training can improve hemodynamics in young, …

Role Of Pote Ankyrin Domain Family Member 2 (Pote-2) In Liver Cancer, Samantha Lopez

Theses and Dissertations

Liver cancer is the fifth leading cause of mortality attributed to cancer. Among various histological types, hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer. There is a need to identify new biomarkers to help the physician, and allow them to decide what may be the most effective treatment for the patient. POTE-2 is one of the 14 paralogs apart of the ancestral POTE gene family. POTE-2 has been shown to be upregulated in non-small cell lung cancer and colorectal cancer, and is associated with increased migration, invasion, tumor size and poor survival. Evaluation of the Cancer Genome …

Revealing The Effects Of Climate Change And Fungicides On Soil Microbial Communities In The Lower Rio Grande Valley, Texas, Armida Rivera

Theses and Dissertations

Fungicide applications are effective to prevent fungal pathogens that are known to cause crop damage and decrease yields. However, these pesticides can exert toxic or inhibitory effects on non-targeted organisms such as soil microbial communities. In addition, it is unknown to what extent shifts in temperature and soil moisture resulting from global climate change, alter the activities of non-targeted soil organisms. The aim of this study was to evaluate soil biological parameters such as soil respiration and enzyme activities involved in the cycling of carbon, nitrogen, and phosphorous (Beta-glucosidase, Fluorescein Diacetate (FDA) Hydrolysis, urease, alkaline phosphatase, acid phosphatase, and N-acetyl-Beta-glucosaminidase) …

Examination Of The Realized Host Range Of North American Lacebug (Gargaphia Arizonica Drake & Carvalho) And Texas False Potato Beetle (Leptinotarsa Texana Schaeffer) As A Potential Biocontrol Agents For Silverleaf Nightshade (Solanum Elaeagnifoli Cav.), Samikshya Subedi

Theses and Dissertations

Silverleaf nightshade (Solanum elaeagnifolium Cav.) is a perennial forb native to South Texas and Central and South America, but it has become a serious agricultural weed across the world. Because silverleaf nightshade (SLN) is difficult and expensive to manage using chemical and mechanical controls, there is growing attention and research focused on biological control options. In this project, we used both field and laboratory studies to examine the suitability of two North American insects, namely North American lacebug (Gargaphia arizonica Drake & Carvalho) and Texas false potato beetle (Leptinotarsa texana Schaeffer) as prospective biological control agents for …

A Review Of Quantum Coherence And Its Effect On Photosynthetic Efficiency In Psii And Fmo Complexes, Matthew Nelson

Chemistry & Biochemistry Undergraduate Honors Theses

Photosynthesis in living organisms is one of the most efficient, natural energy harvesting processes on Earth. The absorption of light energy as photons directly energizes electrons in metabolite molecules. These molecules transfer their high energy electrons through a chain system to provide the energy needed for carbon dioxide metabolism. Recently, it has been a subject of debate how this energy transfer via electron transport achieved such high efficiency. One hypothesis is that this transfer system displays fundamentally quantum mechanical behaviors, such as coherence. Here, I will briefly define this concept in quantum mechanics, and explain the role it might play …

18s-Nemabase: Curated 18s Rrna Database Of Nematode Sequences, Kaitlin Gattoni, Eli M. S. Gendron, Rebeca Sandoval- Ruiz, Abigail Borgemeier, J. Parr Mcqueen, Rachel M. Shepherd, Dieter Slos, Tom Powers, Dorota L. Porazinska

Department of Plant Pathology: Faculty Publications

Nematodes are the most abundant and diverse animals on the planet but lack representation in biodiversity research. This presents a problem for studying nematode diversity, particularly when molecular tools (i.e., barcoding and metabarcoding) rely on well-populated and curated reference databases, which are absent for nematodes. To improve molecular identification and the assessment of nematode diversity, we created and curated an 18S rRNA database specific to nematodes (18S-NemaBase) using sequences sourced from the most recent publicly available 18S rRNA SILVA v138 database. As part of the curation process, taxonomic strings were standardized to contain a fixed number of taxonomic ranks relevant …

Investigating The Role Of The Three N-Terminal Hamp Domains Of The Aer2 Chemoreceptor From Pseudomonas Aeruginosa, Selina Anaya

Loma Linda University Electronic Theses, Dissertations & Projects

Pseudomonas aeruginosa is a ubiquitous environmental bacterium and opportunistic human pathogen. It readily adapts to changing environmental conditions with the aid of 26 chemoreceptors that signal to four distinct chemosensory systems. The Aer2 chemoreceptor from P. aeruginosa is an O2 sensor implicated in stress responses, virulence and fine-tuning the chemotaxis (Che) system. Aer2 is the sole chemoreceptor of the Che2 chemosensory system, which forms complexes at the cell pole during stationary phase. Aer2 is soluble, yet membrane-associated and displays an unusual arrangement with its PAS sensing domain sandwiched between three N-terminal and two C-terminal HAMP domains. HAMP domains are widespread …

A Bayesian Hierarchical Approach For Modeling Virtual Species With Realistic Functional Trait Relationships, Sarah Bogen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Understanding the spatial and temporal dynamics of plant populations has important implications for the fields of ecology and conservation. A rich body of mathematical modeling approaches, including reaction-diffusion equations and integrodifference equations, have been developed to mechanistically model population spread based on species demography and seed dispersal characteristics. However, with over 390,000 plant species on Earth, it is not feasible to collect complete information on all species for the purpose of drawing generalized conclusions. One means of overcoming such a problem is through trait-based modeling, which seeks to represent realistic combinations of organismal traits rather than focusing on individual species. …

Neural And Peripheral Markers Of Reward During Positive Social Evaluation Are Associated With Less Clinician-Rated Depression Symptom Severity In Adolescence, Zach J. Gray, Grant S. Shields, Stassja Sichko, Theresa Q. Bui, Meghan Vinograd, Hector A. Olvera-Alvarez, George M. Slavich

Psychological Science Faculty Publications and Presentations

Although blunted sensitivity to reward is thought to play a key role in promoting risk for depression, most research on this topic has utilized monetary reward paradigms and focused on currently depressed adults. To address this issue, we analyzed neural reward and β-endorphin data from the Psychobiology of Stress and Adolescent Depression (PSY SAD) Study, which recruited a well-characterized sample of adolescent girls at high vs. low risk for major depressive disorder (MDD) (N = 52, M_age = 14.90, SD = 1.35) based on their mothers’ lifetime history of MDD. As hypothesized, greater striatal activity while receiving positive …

Optimising Predictive Models To Prioritise Viral Discovery In Zoonotic Reservoirs, Daniel J. Becker, Gregory F. Albery, Anna R. Sjodin, Timothée Poisot, Laura M. Bergner, Binqi Chen, Lily E. Cohen, Tad Dallas, Evan A. Eskew, Anna C. Fagre, Maxwell J. Farrell, Sarah Guth, Barbara A. Han, Nancy B. Simmons, Michiel Stock, Emma C. Teeling, Colin J. Carlson

Faculty Publications

Despite the global investment in One Health disease surveillance, it remains difficult and costly to identify and monitor the wildlife reservoirs of novel zoonotic viruses. Statistical models can guide sampling target prioritisation, but the predictions from any given model might be highly uncertain; moreover, systematic model validation is rare, and the drivers of model performance are consequently under-documented. Here, we use the bat hosts of betacoronaviruses as a case study for the data-driven process of comparing and validating predictive models of probable reservoir hosts. In early 2020, we generated an ensemble of eight statistical models that predicted host–virus associations and …

Haplotype-Informed Allelic Imbalance Detection From Rna In Cancer, Zuhal Ozcan

Dissertations and Theses (Open Access)

Comprehensive genomic and transcriptomic characterization of tumors has uncovered enrichment for distinct aneuploidy and expression patterns, demonstrating the utility of molecular based classification of cancers and their subtypes. Existing cohorts with transcriptomic profiling from next-generation sequencing contain an untapped potential to also relate genomics with rich clinical phenotypes. Yet, derivation of somatic copy number and expression profiles from analyses of RNA has remained elusive. Further, DNA analysis in these cohorts is not always feasible due to limited tissue availability or financial constraints. Here, we present a statistical approach that overcomes these challenges using haplotype information to aid detection of somatic …

Regulation Of Systemic And Cellular Metabolism In Prostate Cancer By Camkk2 And Elucidation Of Atgl’S Role In Disease Progression, Dominik Awad

Dissertations and Theses (Open Access)

The androgen receptor (AR) is the major driver of prostate cancer; hence, men with progressing disease are treated with androgen deprivation therapy (ADT). However, the majority of patients will relapse within 2-3 years due to multiple AR reactivation mechanisms. Thus, AR and the processes downstream of the receptor remain central drivers of prostate cancer. A direct target of AR is CAMKK2, a gene coding for the serine/threonine kinase Ca^2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2), a protein upregulated in advanced prostate cancer. CAMKK2 modulates many of its pathological effects through the phosphorylation and activation of the 5' AMP-activated …

Decoding The Tumor And Immune Microenvironment In Pdac And Breast Cancer By Single Cell Sequencing., Aislyn Schalck

Dissertations and Theses (Open Access)

This work utilizes single cell RNA sequencing to identify transcriptional populations and gene changes for the purpose of immune-related cancer therapies. First we have characterized the T cell populations of the normal and malignant human pancreas. Furthermore, we utilized single cell TCR sequencing to track transcriptional states of T cell clones from human PDACs into a T cell culture product for adoptive cell therapy. Second, we examined the potential role of radiotherapy in inducing an immune response in hormone receptor positive breast tumors.

Analysis Of The Distributed Representation Of Operant Memory In Aplysia, Renan Murillo Costa

Dissertations and Theses (Open Access)

Operant conditioning, a ubiquitous form of learning in which animals learn from the consequences of behavior, engages a high-dimensional neuronal population space spanning multiple brain regions. A complete characterization of an operant memory remains elusive. Some sites of plasticity participating in the engram underlying an example of operant memory in Aplysia have been previously uncovered. Three studies are described here that sought to draw closer to a thorough characterization of this memory. The first study used a computational model to examine the ways in which sites of plasticity (individually and in combination) contribute to memory expression. Each site of plasticity …

Unraveling The Effects Of Aerobic Exercise And Erk5 Signaling In The Solid Tumor Microenvironment Using Murine Models, Hannah Savage

Dissertations and Theses (Open Access)

Solid tumors are comprised of multiple cell types which communicate and work together to promote tumor progression. Advances in the treatment of solid tumors have armed clinicians with more efficacious pharmacologic agents and combinations. However, a focus on drug adjuvants in the treatment of solid cancer has left gaps in knowledge regarding non-pharmacologic treatment adjuvants, like aerobic exercise. The current dissertation investigates pharmacologic and non-pharmacologic based approaches to remodel the solid tumor microenvironment landscape and alter therapeutic efficacy. We disassemble compartments of the tumor microenvironment, including tumor vasculature and immune infiltrate, using mouse models and single cell techniques, to elucidate …

Decoding Copy Number Substructure And Evolution From Single Cell Genomics, Darlan Conterno Minussi

Dissertations and Theses (Open Access)

Aneuploidy is a prominent feature in Triple-Negative Breast Cancers (TNBC), however, the evolution of genotypes during tumor expansion remains poorly understood. The prevalent model of TNBC evolution is the Punctuated Copy Number Evolution (PCNE), in which tumors undergo a period of elevated genomic instability, acquiring complex genomic rearrangements within a short timeframe followed by clonal stasis. However, these observations rely on limited cell numbers and inherent experimental bias from first-generation single cell technologies. Therefore, the evolutionary trajectory after the punctuated burst remains unknown. To address this question, we sequenced 9,765 cells from 8 primary TNBCs and 6,413 cells from 4 …

Grk3 Connects Angiogenesis And Neuroendocrine Differentiation In Prostate Cancer By Activating Hdac2 That Epigenetically Represses Tsp1 And Rest, Samira Naderinezhad

Dissertations and Theses (Open Access)

Prostate cancer (PCa) is the second most frequent cancer and the second leading cause of mortality in men in the United States. Neuroendocrine prostate cancer (NEPC) is the aggressive subset of castration-resistant prostate cancer (CRPC), found in ~20% lethal CRPC. The mechanisms underlying the progression of PCa to NEPC are still largely unclear, and new drug targets are desperately needed. NEPC is highly vascularized (angiogenic) and characterized by high expression of neuroendocrine markers. However, direct molecular links connecting angiogenesis and neuroendocrine differentiation are elusive.

Since epigenetic regulation has been implicated in NEPC progression, we examined expression patterns of 147 epigenetic …

Development Of Graphical Models And Statistical Physics Motivated Approaches To Genomic Investigations, Yashwanth Lagisetty

Dissertations and Theses (Open Access)

Identifying genes involved in disease pathology has been a goal of genomic research since the early days of the field. However, as technology improves and the body of research grows, we are faced with more questions than answers. Among these is the pressing matter of our incomplete understanding of the genetic underpinnings of complex diseases. Many hypotheses offer explanations as to why direct and independent analyses of variants, as done in genome-wide association studies (GWAS), may not fully elucidate disease genetics. These range from pointing out flaws in statistical testing to invoking the complex dynamics of epigenetic processes. In the …

Genomewide Crispr/Cas9 Screen Identifies Network Of Protein Complexes That Regulate Trim24, Lalit Patel

Dissertations and Theses (Open Access)

TRIM24 is an oncogenic chromatin reader that is frequently overexpressed in human tumors and associated with poor prognosis. However, TRIM24 is rarely mutated, duplicated, or rearranged in cancer. This raises questions about how TRIM24 is regulated and whether changes in its regulation are responsible for its activity in cancer.

To investigate this possibility, I performed a genomewide CRISPR/Cas9 screen library using fluorescence activated cell sorting (FACS) to identify regulators of TRIM24. The screen was enabled by two innovations. I engineered cells with an in-frame knock-in of mClover3 to the endogenous copy of TRIM24 to allow fluorescent monitoring of TRIM24 expression …

Body Temperature And Diet As Drivers Of Obesity Development, Jessie Morrill

Dissertations and Theses (Open Access)

Metabolic disease and obesity affect millions of individuals worldwide and the prevalence of obesity is expected to continue to rise. Mechanisms underlying diet-induced metabolic disease and obesity are complex and are largely unknown. In this dissertation research, we aimed to make advances toward understanding how body temperature and high-fat diet consumption contribute to the development of obesity. Herein, we describe the progress that was made toward three research projects. In the first project, we develop novel animal models to determine the impact of reduced body temperature on obesity development and also demonstrate that severe obesity can be reversed through increased …

Yap And Taz Are Required For Neural Crest-Derived Cardiovascular Development, Shannon Erhardt

Dissertations and Theses (Open Access)

Congenital heart defects (CHDs) are the most common human birth defect, occurring in ~1/100 newborns, and are a leading cause of early infant death. Cardiac neural crest cells (NCCs) are a migratory and multipotent cell population known to aid in the development of the cardiac outflow tract (OFT), valves, and interventricular septum, during embryogenesis. Yap and Taz are downstream effectors of the fundamental Hippo signaling pathway and are vital for proper organ and tissue development, yet their role in neural crest (NC)-derived heart formation is still largely unknown. We generated Yap and Taz conditional knockout (CKO) mice using a Cre-lox …

The Role Of The Hypoxia-Inducible Factor 2 In Pancreatic Cancer: Mechanisms Of Tumor Immunosuppression And Intestinal Radioprotection, Carolina Garcia Garcia

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with dismal prognosis. The only curative option for patients is surgery, but over 80% of patients are not surgical candidates. Unfortunately, PDAC is resistant to the three remaining options. PDAC is characterized by a profoundly hypoxic and immunosuppressive stroma, which contributes to its therapeutic recalcitrance. Alpha-smooth muscle actin+ (αSMA+) cancer-associated fibroblasts (CAFs) are the most abundant stromal component, as well as mediators of stromal deposition. The hypoxia-inducible factors (HIF1 and HIF2) coordinate responses to hypoxia, yet, despite their known association to poor patient outcomes, their functions within the PDAC tumor microenvironment (TME) …

Roles Of Oxidative Stress And Dna Methylation In Cigarette Smoking-Induced Accelerated Acute Myeloid Leukemia Progression, Mary Figueroa

Dissertations and Theses (Open Access)

Acute myeloid leukemia (AML) is a commonly diagnosed cancer in smokers. When current or former smokers have AML, they have worse survival compared to never smoking patients. This has been observed clinically for decades, but then it is unknown how smoking leads to worsened AML survival. Smoking causes oxidative stress and altered DNA methylation that persists for decades in peripheral blood mononuclear cells, but these changes from smoking have not been evaluated in the context of AML. We hypothesize that smoking-induced molecular changes, including altered DNA methylation associated with poor AML prognosis, promote AML. We developed a novel model to …

Lipid Composition And Configuration Drive Biophysical Properties Of The Mammalian Plasma Membrane, Jessica L. Symons

Dissertations and Theses (Open Access)

In the 1970s, it was established that phospholipid (PL) classes are asymmetrically distributed across the (PM) leaflets. Recapitulating strategies coupled with newly developed, high-resolution shotgun lipidomics, our lab confirmed PL class asymmetry and surprisingly measured the endoplasmic leaflet to contain double the number of PLs vs. the exoplasmic leaflet. My re-analysis of classical studies show that PM PL abundance imbalance has been a consistent finding across decades of literature. This is surprising, because bilayers do not tolerate interleaflet area imbalances to the degree that this imbalance would suggest, which prompted us to consider the existence of an elusive membrane resident …

Non-Photic Mechanisms Of Entrainment In Bmal1 Deficient Conditions, Jamie Tran

Dissertations and Theses (Open Access)

Maintaining our internal circadian (i.e. 24 -hour) clock is imperative to our daily biological and mental well-being. Large epidemiological studies have shown that disruptions of our circadian rhythms can lead to poor mental health, metabolic diseases, and various types of cancer. Various external cues that have become a part of the modern times such as electricity, shift -work, rapid travel across various time zones, easier access to nutritionally unbalanced food items, and various rigid social demands have deleterious effects on our internal clock, and generally reduce robustness of the circadian clock. The two following projects aim to examine two fundamental …

The Novel Role Of Dnmbp In Kidney Development, Brandy Walker

Dissertations and Theses (Open Access)

Congenital anomalies of the kidney and urinary tract (CAKUT) accounts for nearly one-fourth of all birth defects and more than 40% of pediatric end-stage renal disease, yet only 10-20% of CAKUT cases have a known monogenetic cause. Human kidneys are composed of up to a million epithelial tubules called nephrons. Disruption of nephron development is one of the many congenital anomalies that cause CAKUT, often resulting in chronic or end-stage renal disease which requires transplant. During nephron epithelialization, the formation of stable cadherin-mediated adhesion junctions is essential for maintaining cell-cell contacts. To understand the cell behaviors underlying abnormalities in renal …

A Molecular And In Vivo Investigation Of Advanced Prostate Cancer: Deconstructing Ampk Activity And Developing An Improved Mouse Model, Sandi Wilkenfeld

Dissertations and Theses (Open Access)

Prostate cancer is one of the leading causes of cancer-related death in men. Prostate cancer is dependent on androgen receptor (AR)-mediated pathways, and AR is therefore targeted to treat advanced prostate cancer. Despite an initial response to current AR-targeted therapies, patients invariably relapse, due in large part to the reactivation of AR through a variety of mechanisms. My goal is to identify pathways downstream of AR that can be therapeutically targeted. We and others previously demonstrated that in prostate cancer, calcium/calmodulin-dependent kinase kinase 2 (CaMKK2) is a direct downstream target of AR, and can promote disease progression through the phosphorylation …