Biology Commons^™

Wildlife Road Mortality Patterns In South Texas And Survey Methodology Improvement, Bradley E. Beer

Theses and Dissertations

Mortalities of wildlife caused by collisions with vehicles along roads are increasing in prevalence, threatening the existence of various species and populations. A better understanding of how mortalities change in response to natural and anthropogenic variables and efficient methods of obtaining mortality data are essential to mitigating such mortalities. This thesis investigates several key elements to improving road mortality surveys in south Texas. First, it was found that road mortality survey counts did not change under a pandemic-related lockdown and that 2 mortality survey observers detect more mortalities than 1. Analysis of brown pelican groundings on Texas State Highway 48 …

The Molecular Evolution Of Insect Opsin Genes, Maria Jose Cardenas Muedano

Theses and Dissertations

Opsins are part of the superfamily of G-coupled receptor proteins and together with chromophores, are responsible for initiating the signal transduction cascade responsible for animal vision. Since opsins have a critical role on visual perception these genes are crucial for a myriad of adaptive traits and behaviors and should show diverse signs of natural selection at the molecular level. Understanding the evolution of opsins across the wide diversity of insect groups will allow us to better understand the evolutionary pressure on insect opsins and serve as a model for both other gene systems and other taxonomic groups of animals that …

Bobcat Identification, Abundance, And Behavior At Road Mitigation Structures In South Texas, Victoria Hanley

Theses and Dissertations

Highways in South Texas fragment the landscape and result in high road mortality rates for the endangered US ocelot (Leopardus pardalis). In response, the Texas Department of Transportation constructed nine wildlife crossing structures (WCS) on Farm-to-Market (FM) 106 which adjoins Laguna Atascosa National Wildlife Refuge in Cameron County, Texas. With ocelots being rare and elusive, bobcats (Lynx rufus) are often used as a surrogate species to study felid behavior at road mitigation structures in South Texas. Bobcats have unique markings which allow them to be individually identified. Three methods of individual identification of bobcats using camera …

Effects Of Disturbance (Mowing) On Florivory And Floral Defenses In Solanum Elaeagnifolium, A Noxious And Worldwide Invasive Weed, Alejandro Rafael Vasquez Marcano

Theses and Dissertations

Chapter 1: Literature Review- In this literature review we have examined weed management as it concerns urban and agricultural ecosystems, as well as the need for mowing assessments as it relates to floral traits and defense against herbivory.

Chapter 2: Experiments- In the experiments we examined the role of mowing on floral growth traits, floral defense traits, and their effect on Manduca sexta specialist herbivores.

Chapter 3: Results- In the results we found SLN flowers to have larger diameters than unmowed flowers; however, flower mass was in line with our predictions as unmowed flowers were heavier in high mowing frequency …

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

Biology Dissertations and Theses

Diabetic retinopathy is an ocular disease which appears in patients who experience progression of diabetes mellitus over a continuous period of time. Oftentimes, patients remain undiagnosed through the first stages of diabetic retinopathy due to the fact that there is not a specific way to determine when a patient develops the disease. Ophthalmologists and other eye specialists diagnose a patient with diabetic retinopathy once the patient begins to show progressed symptoms of the disease. Previous experiments have been performed to increase our knowledge of diabetic retinopathy and early biomarkers of the disease. Several studies have determined the effects of diabetic …

De Novo Transcriptome Analysis Of Orange Jasmine (Murraya Paniculata) Infected With Citrus Greening Disease, Jeffrey Aquino Gomez

Theses and Dissertations

Citrus greening disease, also known as Huanglongbing, is one of the most devastating citrus diseases in the world. Candidatus Liberibacter asiaticus (CLas) is a non-culturable, phloem-limited bacterium that serves as one of two vectors for the transmission of any of the three kinds of greening disease. In cooler climates, the African variant transmitted by the African citrus psyllid (Trioza erytreae) is more prevalent. The Asian form transmitted by the Asian citrus psyllid (Diaphorina citri) where is predominant in warmer conditions and recently discover the American form who is also transmit by Diaphorina citri, was discover in Brazil but has also …

Examination Of Amphibian Community And Environmental Relationships In South Texas Using Environmental Dna (Edna), Sean Michael Collins

Theses and Dissertations

Developing more efficient tools to assess amphibian biodiversity and understanding what environmental variables drive amphibian biodiversity are top priorities, as amphibians are facing extinction events across the globe. Environmental DNA (eDNA) surveys are a promising new tool to asses amphibian biodiversity. Throughout the study eDNA metabarcoding along with a targeted eDNA assay and traditional survey methods were used to provide foundational information on amphibian community assemblages throughout South Texas. Water quality, habitat characteristics and soil composition data were collected and used to examine environmental relationships. eDNA metabarcoding detected significantly more amphibian taxonomic units compared to traditional survey …

The Potential Impact Of Climate Change On The Distributions Of Eleutherodactylus Cystignathoides And E. Planirostris (Anura: Eleutherodactylidae), Rebecca T. Chastain

Theses and Dissertations

Climate change is inducing changes in the distributions of many species, causing range shifts and habitat loss as well as facilitating invasions. It is a broad contributor to global amphibian decline, already causing mass extinctions and extirpations of amphibian populations, a phenomenon which is expected to continue. The understudied direct-developing frog Eleutherodactylus cystignathoides is a notable outlier, having rapidly expanded its distribution in recent years. This is of particular interest given that other eleutherodactylids, such as E. coqui and E. planirostris, have already shown propensity for rapid dispersal and invasion. Originally found in the southernmost tip of …

Removal Of Arsenic (Iii) And Arsenic (V) From Aqueous Solution Via Common Sunflower Helianthus Annuus By Phytoremediation, Irving A. Vazquez Hurtado

Theses and Dissertations

Phytoremediation provides a cost-effective, non-invasive technique to remove contaminants from the soil and groundwater. Sunflowers are fast growing and have a showed effective at removing various pollutants from soil, including lead and other heavy metals. Health issues related to arsenic are mainly attributed to exposure of arsenite, whereas arsenate is much less toxic. The common sunflower Helianthus annuus was the species used to remove both arsenic (III) and As(V) ions from hydroponics solutions. In the present study sunflower seeds were germinated for a week, placed under the sun for a day and subsequently placed in a nutrient solution to aid …

Effects Of Tributyltin Exposure On 8-Ohdg And Dsdna Expressions, Oxidative And Nitrative Stress In The American Oyster, Crassostrea Virginica, Mohan Kumar Dash

Theses and Dissertations

Environmental pollution increases due to anthropogenic activities. Different types of pollutants and/or chemicals impair growth, reproduction and development in aquatic organisms. Tributyltin (TBT, an organotin compound) is a tremendously toxic substance which widely uses as antifouling paints used in boats, hulls, and ships. The toxic effect of TBT is well documented in teleost species. The American oyster (Crassostrea virginica) is an ideal shellfish species to study on TBT exposure DNA lesion and oxidative/nitrative stress. In this study, the effects of TBT on 8’-hyrodxy-2’-deoxyguanosine (8-OHdG, a molecular marker), dsDNA, dinitrophenyl protein …