Digital Commons Network^™

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%, …

Computational Analysis Of The Sir Mathematical Model For The Dengue Fever, Joseph Phillip Diaz

Theses and Dissertations

Dengue fever is a disease affecting people in more than 100 countries. Here we consider a host and vector model for the transmission of dengue fever. This SIR model consists of three compartments of susceptible, infective and removed for host (human) and two compartments of susceptible and infective for vector (dengue mosquitos). These five compartments yield five coupled nonlinear ordinary differential equations (ODEs). After non-dimensionalization, we have a system of three nonlinear ODEs. Reproductive number and two equilibrium points are calculated for various cases. Simulation is carried out for susceptible, infective and removed and the results are presented in graphical …

Liberty, Equality, Indebtedness: Thomas Jefferson, John Adams And The Problem Of Debt In A Revolutionary Age, Martha Salazar Cantu

Theses and Dissertations

In this thesis I examine how the issue of debt contributed to the political tensions between the New England region and the Chesapeake region during the Revolutionary Age. The merging of the two regions’ economies into one federal union caused political divisions, which remained beyond the period of the Early Republic. Examining the cultural attitudes of each region towards debt provides a better understanding of the political problems between these two regions. The integration of the consignment culture of the Southern states with the Puritan ethic of the New England states caused economic difficulties for the young Republic. The research …

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 …

Tabacaleros Al Grito De Guerra: The Mexican Tobacco Industry And The U.S.-Mexico War, Jorge A. Hernandez

Theses and Dissertations

This study analyzes the role of the Mexican tobacco industry during the chaotic years from 1845 to 1847. In nineteenth-century Mexico the tobacco industry was an important financial contributor to Mexican government’s efforts to sustain the war against the United States. Without any significant success, the Mexican government tried to confront and solve the problems limiting the amount of revenues that was expected from the tobacco industry. Regional interests, political factionalism, administrative negligence, and tobacco contraband limited the amount of money the tobacco industry contributed. In spite of all the problems the tobacco industry experienced between 1845 and 1847, the …

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 …

First Astrophysical Observations With The Low Frequency All Sky Monitor, Emma Youmans Handzo

Theses and Dissertations

The Low Frequency All Sky Monitor (LoFASM) is a radio telescope that consists of dipole antennas. It is sensitive to the frequencies of 10-88MHz. The primary science goals of LoFASM are to detect and study low frequency radio transient events and to develop and test low frequency interference (RFI) mitigation techniques.

Once a telescope starts collecting data, it is necessary to calibrate the telescope to convert the data into standard units. This will allow for scientific deductions to be made from the data. Once the calibration of a telescope is complete it is necessary to determine what astrophysical sources are …

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 …

A Handcrafted Multi-Branch Nerve Scaffold For In Vivo Peripheral Nerve Regeneration, Ridwan Fayaz Hossain

Theses and Dissertations

Arm and leg peripheral nerve injuries contribute largely to functional disability. These injuries seldom affect a single-line nerve; rather the injury goes beyond and disrupts the nerve tissue across multiple nerve paths. Here we investigate handcrafted PDMS based multi-branch nerve guidance conduit, which addresses this crucial branching from the sciatic nerve to aid with the regeneration to their appropriate distal targets. The design concept of the developed multiple branch nerve scaffolds is not specific for the sciatic nerve but can be modified for general use of all peripheral nerves and additional applications. Microchannels are also fabricated into a device in …

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 …

3d Reconstruction Of Close Range Objects Using Free And Open Source Software And Raspberry Pi Technologies, Juan Lorenzo Monrreal

Theses and Dissertations

Existing 3D rendering open source software along with Raspberry Pi technology can be used to create an affordable method and workflow for time efficient, accurate and quality scans for 3D printing. The emergence of technology spurs a technological community working to progress in a collaborative effort. This brings a potential to the possibility of efficient and economical solutions to emerging problems, in this case, the ability to render three dimensional scans using free and open source software as well as Raspberry Pi technology. The focus of this paper will be divided into three different aspects including the background needed to …

A New American Fiction: Personal Essays, Observances, And Interviews, Daniel M. Mendoza

Theses and Dissertations

This work consists of essays on the author’s personal development as a writer. It also contains reflections on the state of contemporary American and Mexican-American fiction. The author seeks to illustrate the relevance of certain writers affiliated with working-class fiction, a genre of contemporary American fiction that blends social, political, and aesthetic values into their novels and short stories.

Included in this work are also a number of conversations with writers of working-class fiction. In these conversations the author engages other writers in dialogue that further illuminates the author’s development of his creative identity as a cultural and literary writer.

Re: Publics: Woman Of Color Feminist Rhetorical Process Shaping Safe Spaces For A Rehumanizing Discourse, Eloisa E. Moreno

Theses and Dissertations

The discourse of women of color feminists over the last thirty years follows what I refer to as woman of color feminist rhetorical process in three recursive phases: location, deliberation, and restoration. The process is a significant contribution to rhetorical theory in the form of woman of color consciousness. This way of knowing considers complex identities at the intersections of race, class, gender, and sexual identity. The woman of color feminist rhetorician asks us to view self, community, and our notions of love as political constructs. By doing so, we are able to move beyond identity politics and build new …

Identifying Elements Of A Climate For Sustainability, Rosemond A. Moore

Theses and Dissertations

Sustainability as an area of research is growing in importance not only among academicians, but practitioners as well. A 2010 Accenture study of 700 CEOs found that 93% identified sustainability as important to the long term future success of their organizations. Utilizing CEO sustainability statements Content Analysis was conducted to understand and identify those key elements necessary for a climate for sustainability. A climate for sustainability is one in which sustainability policies, practices, and procedures drive behaviors that are rewarded, supported, and expected within an organization.

Content analysis of CEO statements from organizations recognized for both their sustainability practices as …

Racial Intolerance During The California Gold Rush, Raul David Lopez

Theses and Dissertations

The California Gold Rush started in 1848 and lasted to the mid-1850s. Though short in duration, the impact the Gold Rush had in the United States, along with populations from many areas in the rest of the world, proved detrimental to many different ethnic groups that arrived to the mines and came into contact with various cultures, principally the white Anglo-American culture. This thesis focuses on themes such as race, gender roles, free labor versus unfree labor, extra-legal violence, and informal laws passed in the mines to exclude foreigners. It addresses why certain nationalities were taxed and targeted as foes, …

Facile Sol-Gel Molten Salt Synthesis Of Double Perovskite La 2nimno6 As An Electrocatalyst For Oxygen Evolution Reactions, Padmini Kukkapalli

Theses and Dissertations

Double perovskites have attracted a great attention recently for its high intrinsic activity in oxygen evolution reaction (OER) in electrochemical energy storage and conversion systems in alkaline media. In this study, we are the first to report the new approach of La2NiMnO6 double perovskite which was synthesized via Sol-gel molten-Salt synthesis method. However their stability and specific activity remain challenging that need to be addressed to meet the reqiurement for OER activities. Here in this study we synthesized three different samples with varying concentrations by taking molten salts NaNO 3 and KNO3 in (1:1) ratio such as 30:30, 60:60, 90:90. …

An Exploratory Investigation Of Tele-Counseling: Looking At The Power Of Therapeutic Alliance In Improving Wellness, Jorge Rostro

Theses and Dissertations

The present study explored the power of one tele-counseling session to elicit change within post wellness ratings scores and the relationship between clients’ perceptions of relationship, goals and topics, approach and method, and overall session with clients’ wellness ratings. Results indicated that the mean for post-session wellness was significantly greater than pre-test wellness ratings. The standardized effect size, d, was .43, indicative of a moderate effect size. No difference was found between client’s perceptions of predictor variables with post-wellness rating scores. This study adds support for the use of tele-counseling services as one session might have the power to elicit …

Influence Of Property School Wealth On Fifth Grade Student Achievement In Reading And Mathematics, Jesus R. Reyna

Theses and Dissertations

The purpose of this study was to investigate whether, or to what extent, property wealth of the upper and lower 5% districts, per pupil expenditure, limited English proficient students, economically disadvantaged students, membership, and teacher experience contribute to student achievement in 5th grade reading and mathematics. To do this, the fifth grade reading and math achievement scores, based on the TAKS Assessments, to represent student achievement were evaluated against district wealth, per pupil expenditure, economic disadvantage, limited English language proficiency, membership, and years of teaching experience of teachers for the years 2009, 2010, and 2011. A combination of descriptive statistics, …

De Vida, Regalos E Historias, Monica Skrzypinski

Theses and Dissertations

This thesis is a collection of short stories where the common denominator is women, and a compilation of sensual poems that are authored by the protagonists of each story. Stories and poems are intertwined based in the notion that every human being has a sensual and erotic side. The poems are not a reflection of the stories, but a reflection of the woman. This creative work is best defined as hybrid literature.

Landslide: The 1984 Presidential Election, Colin J. Newton

Theses and Dissertations

Newton, Colin J., Landslide: The 1984 Presidential Campaign. Master of Arts, (MA), December, 2015, 127 pp., 8 figures, references, 57 titles. The thesis provides an in depth historical observation of the events that transpired during the 1984 presidential campaign, which is significant because of its outcome, the largest electoral victory by any presidential candidate. The scope of the research is January 1984 to November 1984. The thesis provides insight into the Democratic primaries and the general election, focusing on the strategies of both campaigns. It identifies the many factors that led to Reagan’s landslide victory.

The overall purpose of the …

The Bourbaki-Jacobson Correspondence, Jose R. Vera

Theses and Dissertations

A general ring theoretic correspondence between subrings of the endomorphism ring of the additive group of a commutative field will be established. This correspondence (called Bourbaki-Jacobson Correspondence) provides the ordinary Galois correspondence when applied to specific group rings. Throughout this thesis, we will work with finite dimensional field extensions.

I Never Left The Borderland, Rosa E. Trevino

Theses and Dissertations

I Never Left the Borderland is a memoir encouraged seven years ago. It was originally meant to be the story of a young girl and her experiences as a migrant student, but once the writing process got under way, the narrative began to evolve. It became a complicated account of how the protagonist, now an adult, felt she was experiencing an inexplicable second coming of age, wrestling with her roles as a wife, mother and scholar. The critical introduction focuses on her relationship with literature and how it kept her sane while she struggled with who she was and who …

Enhancing Academic Achievement And Satisfaction By Flipping The Teacher Preparation Classroom, Rene R. Zuniga

Theses and Dissertations

This study compared flipped classrooms versus online courses to study the effects of the two instructional methodologies on student achievement and satisfaction in an undergraduate Introduction to Education, EDUC 1301, course. Students self-matriculated in either traditional EDUC 1301 courses which were flipped or in EDUC 1301 online courses. Students' final grades were used to assess student achievement in both teaching methodologies. An end-of-course student evaluation of instructor performance was used to assess students' satisfaction in the courses. A casual comparative research design was used to examine the effectiveness of both teaching methodologies. There was no differences between the two instructional …

Exploring Hispanic Teacher Candidates' Beliefs About The Value Of Play In Children's Learning And Development, Diana H. Cortez-Castro

Theses and Dissertations

Play has been globally recognized as valuable to children's learning and development (Frost et al., 2012). The value of play is acknowledged as a developmentally appropriate practice in part because it fosters cognitive, physical, emotional, and social benefits to children. Play is also known as a human right that should be protected. However, in the past five decades there has been a significant decline of play due to multiple and interrelated factors, which are having dire consequences on children's learning and developmental possibilities (Almon & Miller, 2011; Gray, 2013). Due to the challenges posed by the current educational climate, in …

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. …

Pressure Field Estimation Using Particle Image Velocimetry, Jean O. Calzada

Theses and Dissertations

In recent years, scientist and engineers have shown the advantages created by using the Particle Image Velocimetry (PIV) method as flow diagnostic tool to characterize instantaneous velocity fields. One of the important benefits is found on its non-intrusive nature, this leads to accurate velocity fields. From the velocity field obtained by PIV important quantities can be derived, such as pressure and vorticity. The present study, uses PIV data of an incompressible turbulent pulsed jet to determine the pressure field associated with the flow field. The pressure is calculated by using the averaged velocity field along with three different fundamental equation: …

Mack Thomas: The Total Beat, James B. Welton

Theses and Dissertations

Mack Thomas enjoyed both an audience seat and a role in the Beat Generation. He lives the life that fits one of his mottos, “if at first you don’t succeed, quit”. Thomas was the author of two autobiographical novels Gumbo and The Total Beast, a jazz and literature columnist for Grove Press in the 1950s and 1960s. Thomas was also a jazz musician worthy to share the stage with Miles Davis, inventor, and entrepreneur among numerous other interests. His friendship with William S. Burroughs was forged by their Texas ties while they were neighbors living in Paris, France and offered …

The Competitive Environment Of Community Banking And The Potential Impact On Microenterprise Entrepreneurs' Access To Bank Financing, Robert D. Morrison

Theses and Dissertations

Over the past 35 years, Great Depression era regulatory restrictions on the geographic area of operation and the scope of financial services banks can offer have change significantly. These changes fueled a surge of merger activity and resulted in a 70% decrease in the number of bank charters by 2015. Currently, community banks hold only 14% of bank assets in the US; nonetheless, they play an important role in the US economy because they continue to provide the majority of funding to small businesses. This study finds that over 83% of bank failures occurred in metropolitan areas despite the distribution …

The Effect Of A Writing Course On The English Language Arts State Assessment Examination In A South Texas High School, Esmeralda V. Munoz

Theses and Dissertations

The purpose of this study is to analyze the impact a writing course will have on test scores for At-Risk students who are taking the English I and/or English II State of Texas Assessment of Academic Readiness End-of-Course exam. The group analyzed was comprised of 2nd and 3rd year cohort students.