Life Sciences Commons^™

Cover Crops Influence Arthropod Community Dynamics Through Seasonal Variation And Cascading Effects, Adegboyega Fajemisin

Theses and Dissertations

Chapter 1: This chapter gives an overview of how cover crops influence soil’s physical, chemical, and biological properties, and their role on mediating arthropod community dynamics with implications for pest management in the subsequent cash crop.

Chapter 2: This chapter examines the effects of cover-cash crop rotation on arthropod community dynamics on four growers fields in the Lower Rio Grande Valley, Texas. We assessed the impact of cover crops planted in the summer months on the subsequent cash crops planted in the winter. Our results showed that cover crops had a differential effect on the population of beneficials and herbivores …

Life Cycle Assessment Of Calcium Oxide Pretreatment Of Corn Stover With Carbon Dioxide Neutralization For Ethanol Production, Jikai Zhao, Danyi Feng, Juhee Lee

School of Earth, Environmental, & Marine Sciences Faculty Publications

This work used life-cycle assessment (LCA) to determine the environmental and human health impacts of four ethanol production scenarios (S1: CaO pretreatment + H2SO4 neutralization + C6 yeast fermentation; S2: CaO pretreatment + CO2 neutralization + C6 yeast fermentation; S3: CaO pretreatment + H2SO4 neutralization + C6/C5 yeast fermentation; and S4: CaO pretreatment + CO2 neutralization + C6/C5 yeast fermentation), with the functional unit being 1 kg of 95 % ethanol. The LCA results showed that the total ozone depletion, global warming potential, smog, acidification, eutrophication, and ecotoxicity values were comparable when CO2 or H2SO4 were used to adjust the …

Biological Flora Of Coastal Freshwater And Brackish Marshes: Cladium Jamaicense Crantz, Richard Stalter, Robert I. Lonard

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Cladium jamaicense Crantz, also known as sawgrass, has a broad distributional range from the Atlantic coast of Virginia to Florida, to southern Texas, the Caribbean, and along the Atlantic coast of Mexico to Central America, and to Brazil. Cladium jamaicense typically occurs in oligotrophic sloughs and fresh and brackish marshes where optimal salinity values range from 0 to 3.5 ppt. This species is a long-lived perennial with a highly developed rhizome system with rhizomes up to 20 cm long and 2.5 to 10 mm in diameter. Asexual reproduction is common. Its fibrous root system comprises short dauciform roots characterized by …

Oxymatrine Loaded Crosslinked Pva Nanofibrous Scaffold: Design And Characterization And Anticancer Properties, Salahuddin Ahmed, Megan Keniry, Narcedalia Anaya-Barbosa, Victoria Padilla, Md Noushad Javed, Robert Gilkerson, Acharan S. Narula, Eman Ibrahim, Karen Lozano

Mechanical Engineering Faculty Publications

This study focuses on the fabrication, characterization and anticancer properties of biocompatible and biodegradable composite nanofibers consisting of poly(vinyl alcohol) (PVA), oxymatrine (OM), and citric acid (CA) using a facile and high-yield centrifugal spinning process known as Forcespinning®. The effects of varying concentrations of OM and CA on fiber diameter and molecular crosslinking were investigated. The morphological and thermo-physical properties, as well as water absorption of the developed nanofiber-based mats were characterized using microscopical analysis, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. In vitro anti cancer studies were conducted with HCT116 colorectal cancer …

Habitat Use And Winter Site Fidelity Of Lincoln’S Sparrow (Melospiza Lincolnii) In The Lower Rio Grande Valley Of Texas, Timothy Brush, Hugh E. Conway, Catherine C. Brush

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

No abstract provided.

Pathogenicity Of Multiple Providencia Species (Enterobacteriales: Morganellaceae) To The Mass-Reared Mexican Fruit Fly (Diptera: Tephritidae), Bacilio Salas, Hugh E. Conway, Don C. Vacek, Christopher Vitek, Erin Schuenzel

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is used to suppress and eradicate wild populations. Success of this control method necessitates weekly production of hundreds of millions of flies, their sterilization by irradiation, and their aerial release. Diet needed to produce large fly numbers are conducive to the spread of bacteria. Pathogenic bacteria were isolated from 3 rearing facilities and from multiple sources: eggs, larvae, pupae and spent diet, and were found to include some isolates identified to the genus Providencia (Enterobacteriales: Morganellaceae). We …

Rapidly Changing Range Limits In A Warming World: Critical Data Limitations And Knowledge Gaps For Advancing Understanding Of Mangrove Range Dynamics In The Southeastern Usa, Rémi Bardou, Michael J. Osland, Steven Scyphers, Christine Shepard, Karen E. Aerni, Jahson B. Alemu I, Robert Crimian, Richard H. Day, Nicholas M. Enwright, Christopher A. Gabler

School of Earth, Environmental, & Marine Sciences Faculty Publications

Climate change is altering species’ range limits and transforming ecosystems. For example, warming temperatures are leading to the range expansion of tropical, cold-sensitive species at the expense of their cold-tolerant counterparts. In some temperate and subtropical coastal wetlands, warming winters are enabling mangrove forest encroachment into salt marsh, which is a major regime shift that has significant ecological and societal ramifications. Here, we synthesized existing data and expert knowledge to assess the distribution of mangroves near rapidly changing range limits in the southeastern USA. We used expert elicitation to identify data limitations and highlight knowledge gaps for advancing understanding of …

Shortening Of Telomeres Caused By Bacterial Lipopolysaccharides In Hiv-1 Exposed Human Oral Keratinocytes, Daphne Alcala Zúñiga

Theses and Dissertations

The Human Immunodeficiency Virus-1 (HIV-1) continues to affect many individuals around the globe. Although people with HIV (PWH) have longer life expectancies because of modern treatments, they continue to exhibit comorbidities that are signs of premature aging compared to healthy individuals. The significance of the oral microbiome during HIV-1 infection has become of interest as chronic inflammatory conditions, such as periodontitis, have shed light on the detrimental effects of chronic inflammation. HIV-1 infection can promote dysbiosis, an imbalance of the oral microbiota, which in turn promotes the growth of opportunistic microorganisms such as P. gingivalis. This overpopulation enhances pathogenicity through …

Factors Influencing The Faunal Recolonization Of Restored Thornscrub Forest Habitats, Audrey J. Hicks

Theses and Dissertations

Tamaulipan thornscrub forests have high ecological and economic value, yet over 90% of these forests have been lost, primarily due to agriculture and urban expansion, and they remain threatened, making them a conservation hotspot. For decades, federal, state, NGO, and corporate entities have been acquiring land and actively or passively restoring these forests, but results have been mixed and seldom monitored. This study characterized and quantified faunal communities of restored thornscrub forest habitats in south Texas and examined the relationships between restored faunal communities and key site characteristics and environmental factors. We surveyed and analyzed mammals, birds, Lepidoptera, and herptiles …

Effect Of Elevated Temperature And Roundup Exposure On Oxidative Stress And Antioxidant Status In The American Oyster, Afsana Chowdhury

Theses and Dissertations

Aquatic organisms are frequently exposed to various environmental stressors. In this study, we observed the short-term (1-week) combined dose-dependent effect of Roundup, a glyphosate-based herbicide, and high temperature (30°C) on the morphology of gills and digestive glands, expression of heat shock protein-70 (HSP70), dinitrophenyl protein (DNP), nitrotyrosine protein (NTP), antioxidant enzymes such as catalase (CAT) and superoxidase dismutase (SOD) in tissues of American oyster (Crassostrea virginica). Histological analyses showed an increase in mucous production in the gills and digestive glands, hemocyte aggregation in the connective tissues as well as structural change of the lumen in the digestive glands …

Sweet Potato In The Lower Rio Grande Valley: Evaluating Performance Across Several Cultivars, Jon Dale

Theses and Dissertations

In Texas’ subtropical, semiarid Lower Rio Grande Valley (LRGV), citrus and sugarcane cultures have dominated specialty crop production for more than a half-century. However, the future of these high-dollar crops is becoming uncertain with increases in exotic pathogens, intensifying urbanization and the overarching complexities of both climate change and binational governance of Rio Grande Basin waters. For these reasons, the region’s specialty crop sector needs to be ready for alternatives that could benefit both market outlets and reduced input dependencies. Sweet potato (Ipomoea batatas), commercially grown in various similar climates worldwide with limited water resources, could be one …

Population Genetics Among Rhipicephalus Sanguineus Ticks In The Lower Rio Grande Valley, Bianca Liana Guerra

Theses and Dissertations

Rhipicephalus sanguineus is a common tick species in the lower Rio Grande Valley of both human and veterinary concern. Two lineages of R. sanguineus have been described across the United States known as the tropical and temperate lineage. Both lineages can be differentiated morphologically, genetically, biologically, and by vector competence. The species name for both lineages has not been well established therefore this thesis will utilize their widely used identification. Both lineages have been identified in Texas. While the distribution of these lineages has been well-defined in some regions across the world, recent studies have observed sympatric populations in certain …

Study Of Population Dynamics Of Sugarcane Aphid (Melanaphis Sacchari) In Rio Grande Valley, Texas, Neetu Khanal

Theses and Dissertations

Chapter 1: This chapter incorporates detailed information about the biotype concept, aphids, their types and their biotypes, importance of studying insect biotypes and their role in mediating host plant defenses.

Chapter 2: This chapter explains in detail about the biology, biotypes, feeding behavior, damage, and economic loss caused due to sugarcane aphid infestation. This chapter further elaborates on the need for studying population level differences and justifies the objectives and significance of this research study.

Chapter 3: This chapter provides information about the comprehensive work done on three different populations of sugarcane aphid collected from three different locations in Rio …

Biological Optimization Of Polymer-Based Antiretroviral Drug Towards The Gut-Associated Lymphoid Tissue (Galt), Arkajyoti Paul

Theses and Dissertations

Background: Combination antiretroviral therapy (cART) has significantly decreased the disease mortality associated with HIV-1 but does not efficiently reach the HIV reservoir organs such as GALT. In this regard, the present study determined the efficacy of the polymer-based nanoformulations using F127 alone and in combination with L61 to encapsulate three clinically available cART drugs such as Emtricitabine (FTC), Tenofovir Disoproxil Fumarate (TDF), and Dolutegravir (DTG) in in vitro and in vivo system. Methods: The selected formulations were studied for their biological and chemical characterization towards human cell line viz. Caco-2 and Human peripheral blood mononuclear cells (PBMC) and in vivo …

Road Mitigation Structure And Road Effect Zone Impacts On Rodent Community Composition, Activity, And Predator-Prey Dynamics In South Texas, Adam F. Sanjar

Theses and Dissertations

The effects of road mortality mitigation structures on rodent activity and rodent community composition are not fully understood, both on the regional scale of south Texas and in the broader field of road ecology. This is primarily due to the low conservation priority of most rodent species and the difficulty of noninvasively surveying for rodents effectively. This thesis focused on characterizing how rodents were impacted by both roads and mitigation structures in south Texas, and if rodents are a significant factor to consider when studying the road ecology of rodent predators in south Texas, particularly ocelots, bobcats (Lynx rufus …

Structural And Functional Insight Of Helicobacter Pylori Translation Initiation Factor If1 (Hpif1) In Protein Biosynthesis And Rational Design Of New Antimicrobial Candidates, Asif Shahriar

Theses and Dissertations

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human gastric mucosa and is associated with peptic ulcer disease and gastric cancer. Bacterial protein synthesis is a fundamental metabolic process occurring in all bacteria and is a validated target of antibiotics; however, the precise structural mechanism of H. pylori protein biosynthesis remains unknown. Protein synthesis contains four stages, and translational initiation is the most important and highly regulated critical step, involving three initiation factors (IF1, IF2, IF3) and other key components. IF1 plays a vital role in regulating this step by binding to the 30S ribosomal subunit cooperatively …

Red Snapper Abundance, Growth, And Movement At Different Structural Configurations In The Rio Grande Valley Artificial Reef, Marybeth J. Weihbrecht

Theses and Dissertations

The Rio Grande Valley (RGV) artificial reef was built with the goal of providing habitat for reef fish at various life stages. This study used fish trapping to analyze red snapper and grey triggerfish size and abundance in the RGV reef. Mark-recapture of red snapper was utilized to determine growth, movement, and site fidelity within the reef. Nine configurations of patches consisting of varying combinations and densities of concrete pyramids and low-profile modules were surveyed, as well as additional sites of cinder block palettes and concrete railroad ties. Red snapper and triggerfish abundance per trap hour varied significantly by site …

Identifying Direct Foxo Targets Through Chromatin Immunoprecipitation Assays With Sequencing, Alma Lopez

Theses and Dissertations

Glioblastoma Multiforme (GBM) and basal-like breast cancer (BBC) are aggressive cancers associated with poor prognoses. Basal-like breast cancer (BBC) and glioblastoma multiforme (GBM) are poor prognosis cancers that lack effective targeted therapies. A deregulation of FOXOs has been linked to cancer, as they regulate the expression of genes involved in multiple cellular processes. Canonically, the FOXO family of proteins is generally considered tumor suppressors, but evidence suggests that they may be involved in cancer metabolism as well as angiogenesis. Research in our lab has found that these factors play a role in glycolysis and the developmental WNT pathway. Here we …

Predictive Ecology And Management Of Phyllosphere Microbial Communities Through Cross-Scale Synthesis, David W. Armitage, Morgan E. Carter, Robin A. Choudhury, Mitja Remus-Emsermann, Cindy E. Morris, Johan H. Leveau, Linda L. Kinkel, José Pablo Dundore-Arias

School of Earth, Environmental, & Marine Sciences Faculty Publications

Here we summarize the main takeaways from a symposium and hybrid virtual and in-person participatory discussion focused on the challenges of scale in understanding the ecology and management of phyllosphere microbial communities. We provide an overview of the confounding effects of spatial scale on inference in microbial ecology, the spatial organization of microbial interactions in the phyllosphere, advances and remaining gaps in measuring phyllosphere colonization across scales, and the epidemiology in the phyllosphere. We hope to motivate further discussion and the development and adoption of creative approaches to solving the challenges of scale to enhance fundamental understanding and practical management …

Estimating The Functional Consequences Of Intra-Specific Trichome Variation Of Tomato, Solanum Lycopersicum On The Specialist Herbivore, Manduca Sexta, Satinderpal Kaur

Theses and Dissertations

Chapter 1: Plants have a wide array of defenses against herbivores and hence they must confer trade-offs between growth and defense related traits. By using Solanum as a model genus, the major plant defense fitness trade-off hypotheses are reviewed in this chapter along with their assumptions and examples.

Chapter 2: This chapter provides an overview of the enormous intra-specific diversity in trichome morphology in tomato, Solanum lycopersicum. Also, the trichome sub-types are analyzed for the variations in density and dimensions in 10 varieties of tomato by using desktop scanning electron microscope.

Chapter 3: This chapter examines the functional consequences …

Activation Of Opa1 Processing In Differentiated Myoblast Cells, Omar Agustin Carrillo

Theses and Dissertations

Mitochondria are eukaryotic cellular organelles that play a role in energy production, apoptosis, integrated stress response, and aging. Mitochondrial dynamics is the physical fusion (interconnection) and fission (fragmentation) of mitochondria within a cell and tightly regulates mitochondrial functions. Optic atrophy 1 (OPA1) is a dynamin-related GTPase located in the inner mitochondrial membrane, and is responsible for inner mitochondrial membrane fusion. OPA1 exists in five isoforms, the two fusion-active long OPA1 (L-OPA1) and the three fusion-inactive short OPA1 (S-OPA1) isoforms. When the transmembrane potential (∆ψm) is aggravated, the inner membrane metalloprotease OMA1 is activated, causing the complete cleavage of L-OPA1 to …

Microbial Associations With Metcalf's Tryonia, Tryonia Metcalfi (Gastropoda: Cochliopidae), An Imperiled Ciénega Endemic, Russell L. Minton, Kathryn E. Perez

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The Chihuahuan Desert swamps are a hotspot for imperiled organisms including freshwater springsnails and bacteria. Many of these taxa are endemic to the desert and to the individual waterbodies where they occur. Efforts to conserve diversity in these threatened areas must account for the life history of the organisms, but also interactions between organisms including microbes. We documented the microbial assemblage associated with Tryonia metcalfi, a critically imperiled freshwater snail endemic to a ciénega system in western Texas. We identified 14 bacterial families in our snail samples and determined a core assemblage of 19 bacterial taxa (4 of which …

Dopamine Dysregulation In Antiretroviral Drugs Treated Neuronal Cells, Andrea S. Bustos

Theses and Dissertations

According to the world health organization (WHO), 37.7 million people worldwide in 2020 were living with the human immunodeficiency virus (HIV-1). In the US, combination antiretroviral therapy (cART) drugs have shown effectiveness in combating HIV-1 infection. As a result, cART has prolonged the lifespan of people with HIV aiding these patients to age with the virus. Clinical evidence has established the long-term effects of cART in the aging population causing neuropsychiatric disorders such as depression. However, the underline molecular mechanism that cART induces depression-related neurodegeneration has not been established. This study will pursue a dopamine (DA) dysregulation marker in cART …

Understanding The Developmental Regulation Of Opa1 Processing In C2c12 Myoblasts, Harpreet Kaur

Theses and Dissertations

Mitochondria is an energy-producing organelle in the cell that accept electrons from the Krebs cycle to generate energy in the form of ATP by oxidative phosphorylation. Two mitochondrial aspects, bioenergetics and dynamics are critical for energy balance and cellular stress responses. Mitochondrial dynamics refers to the balance between mitochondrial fusion (mitochondrial biogenesis) and mitochondrial fission (mitochondrial fragmentation). Cellular stress conditions that lead to dissipation of transmembrane potential (Δψm) trigger the activation of an IMM protein, OMA1, a metalloprotease that leads to processing of another IMM protein, optic atrophy-1 (OPA1) that mediates IMM fusion. Persistent stress primes the mitochondria to mitophagy …

Detection Of A Diverse Endophyte Assemblage Within Fungal Communities Associated With The Arundo Leaf Miner, Lasioptera Donacis (Diptera: Cecidomyiidae), Marie-Claude Bon, John A. Goolsby, Guy Mercadier, Fatiha Guermache, Javid Kashef, Massimo Cristofaro, Ann T. Vacek, Alan Kirk

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The larvae of Lasioptera donacis Coutin feed on fungal communities lining galleries within the mesophyll of leaf sheaths of Arundo donax in an aggregative manner. It has been stated that L. donacis could have established a fundamental symbiotic relationship with one fungus, although the fungal composition of these communities remains unsettled. Using a culture-dependent approach and ITS sequencing, the present work characterizes and compares the fungal communities associated with L. donacis in Eurasia with the endophytes of A. donax in Texas where L. donacis is absent. The 65 cultivable isolates obtained from L. donacis fungal communities were sorted into 15 …

Detection Of A Diverse Endophyte Assemblage Within Fungal Communities Associated With The Arundo Leaf Miner, Lasioptera Donacis (Diptera: Cecidomyiidae), Marie-Claude Bon, John A. Goolsby, Guy Mercadier, Fatiha Guermache, Javid Kashef, Massimo Cristofaro, Ann T. Vacek, Alan Kirk

School of Earth, Environmental, & Marine Sciences Faculty Publications

The larvae of Lasioptera donacis Coutin feed on fungal communities lining galleries within the mesophyll of leaf sheaths of Arundo donax in an aggregative manner. It has been stated that L. donacis could have established a fundamental symbiotic relationship with one fungus, although the fungal composition of these communities remains unsettled. Using a culture-dependent approach and ITS sequencing, the present work characterizes and compares the fungal communities associated with L. donacis in Eurasia with the endophytes of A. donax in Texas where L. donacis is absent. The 65 cultivable isolates obtained from L. donacis fungal communities were sorted into 15 …

Biodiversity Of Forage Fishes In The Lower Laguna Madre, Southernmost Texas, David Camarillo Jr., Elizabeth Mogus Garcia, Carlos E. Cintra-Buenrostro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Coastal estuarine ecosystems serve as nursery habitats for many commercially and recreationally important fishes. Biodiversity is a structural indicator and has been used as a metric for conservation and management. In the hypersaline Lower Laguna Madre of Texas, a variety of organisms makes their living in and around the dominant seagrass vegetation. This study provides a general assessment of forage fishes biodiversity collected seasonally with bag seines in two sites: Holly Beach (HB) and South Bay (SB) within the most southern Texas bay system as part of a broader study on fish biology. A total of 15,880 fishes representing 32 …

Is Lineage C A Distinct Species?, Shiza Khan

Honors Theses

No abstract provided.

Characterizing The Response Of The Coastal Rio Grande To Upstream Damming, Timothy A. Goudge, John M. Swartz, Tian Y. Dong, David Mohrig

School of Earth, Environmental, & Marine Sciences Faculty Publications

Dams are major obstructions to the flow of water and the transport of sediment in rivers. Much work has shown the construction of dams, and storage of sediment in reservoirs, can lead to significant changes in the morphodynamic behavior of alluvial rivers; however, in most cases, the effect of damming has a finite downstream limit as sediment is supplied back to the river through channel bed/bank erosion and/or tributary inputs. Here we present a study of a natural experiment that isolates one source of sediment downstream of a dam – the lower Rio Grande, which has no major tributary inputs …

Aloe Barbadensis Rinds Employ Physical And Chemical Defense Mechanisms Against Insect Herbivores With Varying Success, Zachary Johnson, Ishveen Kaur, Fernando Castillo, Rupesh R. Kariyat, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences Faculty Publications

Plants deter herbivory through a suite of physical and chemical defenses. While most studies have focused on understanding one or the other, efficient plant defense against herbivory is often cumulative. To examine this, we used Aloe barbadensis (Asphodelaceae) as a model, since in natural settings, the species is found to be well-defended against insect herbivores. To start with, we hypothesized that the epicuticular wax potentially plays an important role in herbivore defense as the major physical defense. To test our hypothesis, we conducted bioactivity-guided extraction and polarity-based fractionation of A. barbadensis rinds. We then mixed them into an artificial diet, …