Life Sciences Commons^™

An Inventory Of Endemic Leaf Litter Arthropods Of Arkansas With Emphasis On Certain Insect Groups And Diplopoda, Derek Alan Hennen

Graduate Theses and Dissertations

Endemic arthropods of Arkansas were sampled and their nomenclature and distributions were updated. The Arkansas endemic species list is updated to 121 species, including 16 species of millipedes. A study of the millipedes of Arkansas was undertaken, and resulted in the first checklist and key to all millipede species in the state. 68 species are known from Arkansas, including the genera Cylindroiulus and Polydesmus. The first state records for Ophyiulus pilosus, Cylindroiulus sp., and Ptyoiulus coveanus are reported, and new county records are reported for 16 species. This represents the first key to a state's species since 1980, and the …

Validating Side Scan Sonar As A Fish Survey Tool, Michael A. Bollinger

Theses and Dissertations

Hydroacoustic methods can be used to answer a variety of questions regarding fish populations and behavior. In this study, side scan sonar methodology was developed to quantify abundance and biomass and compared to established visual observation methods on SCUBA over artificial reef structures in the western Gulf of Mexico. Side scan sonar methods were equivalent to SCUBA surveys for measuring fish abundance over the same reef areas, however, abundances were significantly higher when the larger area sampled by side scan was utilized. Side scan sonar methods were also more time efficient than SCUBA, ROV and long line fishing methods (66.7%, …

Examination Of The Chagas Disease Vector, Triatoma Gerstackeri, In The Lower Rio Grande Valley, Alfredo Flores

Theses and Dissertations

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, which is carried by an insect vector of the family Reduviidae, and of the subfamily Triatomina. The species Triatoma gerstaeckeri is identified as the primary vector of T. cruzi within the Rio Grande Valley. Species of Triatoma gerstaeckeri were trapped in La Sal del Rey National Refuge in 2012 and 2013.

Data indicates a seasonal dispersal pattern of activity for T. gerstaeckeri. Optimal time of capture was between 1-2 hours after sunset. Different methods were utilized to determine the best combination of lures. Results indicate that the UV-light alone is …

Decomposition And Nitrogen Dynamics Of Turtle Grass (Thalassia Testudinum) In A Subtropical Estuarine System, Monica Delgado

Theses and Dissertations

Seagrass beds are pivotal in the functioning of coastal ecosystems in terms of productivity, organic matter turnover and nutrient cycling. Aiming to document decay and nitrogen (N) dynamics of turtle grass (Thalassia testudinum) in a subtropical estuarine system, decomposition patterns of leaves and rhizomes were characterized and compared. Nitrogen usage during decomposition of tissues, and of live tissues and epiphytes growing on live leaves, was also quantified and compared. Stable isotope ratios allowed tracing N within the seagrass bed, following N incorporation into seagrass tissues from the surrounding media (water, sediment). Leaves had a higher N content and decomposed at …

Activation Of Microglia In The Rotenone Lymnaea Stagnalis Model Of Parkinson's Disease, Xiomara Galvan

Theses and Dissertations

Parkinson’s disease (PD) is the most common irreversible neurodegenerative movement disorder affecting approximately ten million people worldwide. In the central nervous system (CNS), PD is known by the selective loss of Dopamine (DA) cells of the substantia nigra pars compacta. Although the disease has been very widely studied, the underlying mechanisms are not yet understood. Several hypotheses have arisen as result of injury of the mitochondria, some experiments include microglia activation, microtubule damage, and reactive oxidative species, which all result in the death of DA cells. The theory of microglia activation upon inflammation was explored in this study. Using the …

Balanus Eburneus (Crustacea: Cirripedia) As A Potential Indicator Of Estuarine System Recovery In South Texas: A Study Of Recruitment, Growth And Stable Isotopes, Crystal Martinez

Theses and Dissertations

Population characteristics of the barnacle Balanus eburneus were analyzed with the purpose of exploring its potential use as a discriminating indicator among sites exhibiting different disturbances or stages of recovery. The study was conducted from May 2012 to May 2013 at four estuaries in the Lower Laguna Madre, TX including a) Bahia Grande, currently under restoration and divided into Bahia Grande North and Bahia Grande South, b) San Martin Lake, which receives runoff water and c) South Bay, a relatively undisturbed reference estuary. In general, similar barnacle recruitment and growth trends in Bahia Grande South and South Bay were explained …

Effects Of Shrub Encroachment And Removal On South Texas Coastal Prairie Flora, Parker Alex Watson

Theses and Dissertations

Watson, Parker Alex, Effects of shrub encroachment and removal on South Texas coastal prairie flora. Master of Science, December, 2015. 60 pages, 14 tables, 11 figures, 47 references, 5 appendices. Native-invasive honey mesquite (Prosopis glandulosa) and huisache (Acacia farnesiana) are aggressively encroaching onto South Texas coastal prairies, outcompeting Gulf cordgrass (Spartina spartinae) and associated prairie vegetation with potential legacy effects on the landscape. To measure conditions in the presence of shrubs, data loggers were installed for 16 mos in shrub understories and grass cover to monitor light, soil and air temperatures. Vegetation and canopy surveys were also conducted to evaluate …

Comparing Reproductive Capacity Of Nearshore And Offshore Red Snapper, Lutjanus Campechanus, On Artificial Reefs In The Western Gulf Of Mexico, Ricky J. Alexander

Theses and Dissertations

Red snapper collected quarterly from four artificial reefs in south Texas were examined to compare total length, total weight, age, and the proportion of male to female red snapper, calculate gonadosomatic index values, batch fecundity, annual spawning frequency, and annual fecundity, and estimate size and age at maturity. Spawning occurred from April to September, with most active spawning observed in June (58%). Despite larger red snapper producing more eggs, and fish being larger offshore, most active spawning (68%) and egg production (74%) was observed nearshore. Female red snapper reached 50% maturity (L50) between 350-550 mm, and L75 by 600 mm. …

Infection Rates And Distribution Of Trypanosoma Cruzi In Triatomine Insects From Several Public Parks Of Starr, Hidalgo And Cameron Counties, Carlos Guzman Jr.

Theses and Dissertations - UTB/UTPA

Chagas disease is caused by the protozoan Trypanosoma cruzi and is a major public health concern in many areas of the world, including the United States. The disease is transmitted by insect vectors known as kissing bugs from the subfamily Triatominae. While the majority of studies focus on domestic and peri-domestic collections, this study collected insect vectors from state parks in the Lower Rio Grande Valley. PCR analysis was done to obtain infection rates for collected insects, and a morphological examination was done to check insects for gender. In total 18 insects were captured with 12 of the captured insects …

Exploration Of Nickel Tolerance And Hyperaccumulation In Arabidopsis Thaliana Transformed With Streptanthus Polygaloides Metal Tolerance Protein 1 (Spmtp1) Cdna, Madeleine K. Sano

Theses and Dissertations - UTB/UTPA

This study evaluated the role of hyperaccumulator S. polygaloides Metal Tolerance Protein 1 (SpMTP1) in conferring Ni tolerance and accumulation in the non-accumulator Arabidopsis thaliana. Analysis for Ni content in transgenic Arabidopsis transformed with SpMTP1, following a 12-day treatment of 100 µM Ni, showed a significant increase in Ni concentration in comparison to the wild-type Arabidopsis and empty vector transformed plants. Exposure of transgenic Arabidopsis to nickel also resulted in a coordinated increase of antioxidant enzyme (superoxide dismutase, glutathione reductase, and catalase) activities in the transgenic Arabidopsis, suggesting that increased activities of these oxidative stress response (OSR) proteins may be …

Characterization Of Oxidative Stress Response Proteins In Metal-Tolerant And Metal-Sensitive Brassicaceae Plant Species, Luis M. De Santiago

Theses and Dissertations - UTB/UTPA

In this study the expression of oxidative stress response (OSR) proteins in nonaccumulator and hyperaccumulator plant species of the Brassicaceae family were characterized. Oxidative stress was induced via nickel treatment and proteins were characterized through western blotting and image analysis. Statistical analysis indicated that the nonaccumulator species Arabidopsis thaliana significantly decreased catalase (CAT), glutathione reductase (GR), copper/zinc-dependent superoxide dismutase (Cu/ZnSOD), iron-dependent SOD (FeSOD), manganese-dependent SOD (MnSOD) and metal tolerance protein 1 (MPT1) expression in response to Ni-treatment. The hyperaccumulator species Thlaspi montanum variety montanum displayed either no significant change or a significant increase in OSR regulation following Ni-treatment with the …

Ecosystem Services Of Urban Trees And The Impacts Of Urbanization, Jorge E. Cantu

Theses and Dissertations - UTB/UTPA

The University of Texas- Pan American has conducted a complete survey of campus trees in partial fulfillment of the requirements for membership in the International Society of Arboriculture Designation of Tree Campus USA. This tree inventory was accomplished with the help of students whom were trained by faculty and foresters. Other than the completion of the tree inventory, this thesis had two main goals; 1) valuate the ecosystem services provided by campus trees 2) create a unique service learning project that other institutions can model. According to our calculations, the trees on campus have sequestered 568,652 kg of CO2, avoided …

Loss Of Mitochondrial Dna Causes Decreased Cell Viability, Alan M. Herrera

Theses and Dissertations - UTB/UTPA

Mitochondria are an organellar network involved in cellular bioenergetics and apoptosis, and dynamically balance their organization between fusion and fission events. Mitochondrial DNA (mtDNA) and nuclear DNA combine to encode polypeptides for the complexes of oxidative phosphorylation (OXPHOS) in the mitochondrial inner membrane, which generate a transmembrane potential (ΔΨm) to synthesize ATP. Loss of ΔΨm causes mitochondrial fission, which appears to be associated with the progression of apoptosis, a critical cell death mechanism that allows tissue homeostasis, developmental sculpturing, and the removal of unwanted cells. Using cultured human cell models of decreased ΔΨm (both genetic mtDNA-depleted ρ 0 and pharmacological …

Functional Analysis Of The Mms19 Gene In Carica Papaya, Jorge A. Trujillo

Theses and Dissertations - UTB/UTPA

All organisms face DNA-damaging radiation in the form of UV light and must have mechanisms to repair or undo damage. Plants being stationary organisms must cope with damaging UV rays in a molecular fashion and so have developed many forms of resistance. MMS19 is implicated in DNA repair indirectly as a nuclear encoded gene that binds onto protein assembly complexes in the cytosol. A mutant within the SunUp variety of Carica papaya has a large deletion for MMS19 and presents a diminutive phenotype. Deficient DNA repair mechanisms will shunt cells out of the natural cell cycle and reduce cell proliferation …

Dlipin-A Link Between Lipid Metabolism, Glucose Homeostasis And Growth In Drosophila Melanogaster, Sandra Schmitt

Graduate Theses and Dissertations

Lipins are a family of highly conserved proteins found from yeasts to humans. Lipins have dual functions, serving as phosphatidate phosphatase enzymes (PAP) in the synthesis of neutral fats (triacylglycerols, TAG) and as transcriptional co-regulators that affect the expression of genes involved in lipid and fatty acid metabolism. Thus, they play central roles in metabolic control. Disruption of Lipin function has been implicated in lipodystrophy, obesity and insulin resistance. Using dLipin, the Drosophila homolog of Lipin, as a model, I aimed to elucidate the relationship between the two biochemical functions of Lipin and metabolic homeostasis. I discovered there is a …

Management Of A Primordial Problem: Redox-Sensitive Transcriptional Regulation In Methanosarcina Acetivorans, Ryan Christopher Sheehan

Graduate Theses and Dissertations

The primordial Earth which hosted the first forms of life was an environment free of oxygen. Early organisms utilized metabolisms dependent upon anaerobic conditions and incorporated systems to which oxygen is deleterious. As the content of oxygen in Earth's atmosphere increased, anaerobic organisms had to acquire methods to sense and combat oxygen and reactive oxygen species. Several mechanisms were advantageous to such anaerobic organisms which correlated transcriptional processes with the redox state of the cell so that energy may be conserved and oxygen stress recovery genes activated during periods of oxidative stress. Iron sulfur (Fe-S) cluster cofactors incorporated within RNA …

Differential Gene Expression Between Two Developmental Stages Of The Gené'S Organ In The Cattle Fever Tick, Rhipicephalus (Boophilus) Microplus, Jason P. Tidwell

Theses and Dissertations - UTB/UTPA

The southern cattle fever tick (SCFT), Rhipicephalus microplus, is considered the most economically important ectoparasite of livestock worldwide and ranks sixth among the most pesticide resistant arthropods globally. This single-host hard tick is a vector of the infectious agents causing bovine babesiosis and anaplasmosis. The estimated impact of these SCFT-borne diseases on the livestock industry in the world is $7 billion annually. This project focuses on the Gené’s organ and addresses the need to identify novel targets that can serve as the basis for sustainable SCFT control strategies. Wax secreted by the Gené’s organ protects tick eggs from desiccation, bacterial …

The Role Of Oxidative Stress In The Rotenone Model Lymnaea Stagnalis, Homero L. Cantu

Theses and Dissertations - UTB/UTPA

Parkinson’s disease (PD) is the most common neurodegenerative movement disorder, characterized by progressive depletion of dopamine (DA). Rotenone, a common pesticide, can induce PD like symptoms in animal models. The goal of this thesis is to quantify the levels and effects of reactive oxygen species (ROS) in brain tissue of the common neurobiological gastropod model, Lymnaea stagnalis, after treatment with Rotenone. The results show that rotenone causes a behavioral deficit and increases ROS production, especially superoxide. Furthermore, glutathione was depleted and protein carbonyl formation increased. These results are consistent with findings in human PD and the high levels of ROS …