Digital Commons Network^™

Evaluation Of Sources And Patterns Of Elemental Composition Of Pm2. 5 At Three Low-Income Neighborhood Schools And Residences In Quito, Ecuador, Amit U. Raysoni, Rodrigo X. Armijos, M. Margaret Weigel, Patricia Echanique, Marcia Racines, Nicholas E. Pingitore, Wen-Whai Li

School of Earth, Environmental, & Marine Sciences Faculty Publications

Elemental characterization of fine particulate matter was undertaken at schools and residences in three low income neighborhoods in Quito, Ecuador. The three zones were located in the northern (Cotocollao), south central (El Camal), and south east (Los Chillos) neighborhoods and were classified as zones 1–3, respectively. Forty elements were quantified via ICP-MS analysis. Amongst the geogenic elements, the concentration of Si was the most abundant followed by S, Al, and Ca. Elements with predominantly anthropogenic sources such as Zn, V, and Ni were higher in zone 3 school followed by zone 2 and zone 1 schools. Enrichment factors were calculated …

Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico: Part 1—Model Description And Idealized Hypoxia, Kenneth A. Rose, Sean Creekmore, Peter Thomas, J. Kevin Craig, Md. Saydur Rahman, Rachael Miller Neilan

School of Earth, Environmental, & Marine Sciences Faculty Publications

We developed a spatially explicit, individual-based model to analyze how hypoxia effects on reproduction, growth, and mortality of Atlantic croaker in the northwestern Gulf of Mexico lead to population-level responses. The model follows the hourly growth, mortality, reproduction, and movement of individuals on a 300 × 800 spatial grid of 1-km² cells for 140 years. Chlorophyll-a concentration, water temperature, and dissolved oxygen (DO) were specified daily for each grid cell and repeated for each year of the simulation. A bioenergetics model was used to represent growth, mortality was assumed stage- and age-dependent, and the movement behavior of juveniles and …

Search For Gravitational Waves From Scorpius X-1 In The First Advanced Ligo Observing Run With A Hidden Markov Model, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

Results are presented from a semicoherent search for continuous gravitational waves from the brightest low-mass X-ray binary, Scorpius X-1, using data collected during the first Advanced LIGO observing run. The search combines a frequency domain matched filter (Bessel-weighted F-statistic) with a hidden Markov model to track wandering of the neutron star spin frequency. No evidence of gravitational waves is found in the frequency range 60-650 Hz. Frequentist 95% confidence strain upper limits, h095%=4.0×10-25, 8.3×10-25, and 3.0×10-25 for electromagnetically restricted source orientation, unknown polarization, and circular polarization, respectively, are reported at 106 Hz. They are ≤10 times higher than the theoretical …

Assessment Of The Effects Of Azimuthal Mode Number Perturbations Upon The Implosion Processes Of Fluids In Cylinders, Michael R. Lindstrom

School of Mathematical & Statistical Sciences Faculty Publications

Highlights

• Implosion instabilities are studied by linearizing about a symmetric implosion.

• This suggests azimuthal instabilities decrease with time and mode number.

• Numerics capture the delta functions from linearized solutions of conservation laws.

• The mass of these delta functions is used to estimate perturbations in shock fronts.

• The linear Klein–Gordon equation in one dimension is solved via formal asymptotics.

Abstract

Fluid instabilities arise in a variety of contexts and are often unwanted results of engineering imperfections. In one particular model for a magnetized target fusion reactor, a pressure wave is propagated in a cylindrical annulus comprised of a dense fluid before …

Front Dynamics Of Elliptical Gravity Currents On A Uniform Slope, S. J. Zhu, ‪Nadim Zgheib, S. Balachandar, A. Ooi

Mechanical Engineering Faculty Publications

In the present investigation, we report data from direct numerical simulations of elliptical, finite release, Boussinesq gravity currents propagating down a uniform slope. The study comprises a series of simulations of elliptical gravity currents on a range of slope angles. The shape parameters are varied to study the effects of the initial cross-sectional aspect ratio (Λ0) and mean height to lock radius ratio (Γ) on the dynamics of the gravity current. It is found that the long-time development of the current spatial mass distribution is influenced by its initial shape at smaller slope angles (θ=5∘ and 10∘) whereas the long-time …

Dissipationless Hall Current In Dense Quark Matter In A Magnetic Field, Efrain J. Ferrer, Vivian De La Incera

Physics & Astronomy Faculty Publications

We show the realization of axion electrodynamics within the Dual Chiral Density Wave phase of dense quark matter in the presence of a magnetic field. The system exhibits an anomalous dissipationless Hall current perpendicular to the magnetic field and an anomalous electric charge density. Connection to topological insulators and 3D optical lattices, as well as possible implications for heavy-ion collisions and neutron stars are outlined.

Mechanosensing Of Shear By Pseudomonas Aeruginosa Leads To Increased Levels Of The Cyclic-Di-Gmp Signal Initiating Biofilm Development, Christopher A. Rodesney, Brian Roman, Numa Dhamani, Benjamin J. Cooley, Ahmed Touhami, Vernita D. Gordon

Physics & Astronomy Faculty Publications

Biofilms are communities of sessile microbes that are phenotypically distinct from their genetically identical, free-swimming counterparts. Biofilms initiate when bacteria attach to a solid surface. Attachment triggers intracellular signaling to change gene expression from the planktonic to the biofilm phenotype. For Pseudomonas aeruginosa, it has long been known that intracellular levels of the signal cyclic-di-GMP increase upon surface adhesion and that this is required to begin biofilm development. However, what cue is sensed to notify bacteria that they are attached to the surface has not been known. Here, we show that mechanical shear acts as a cue for surface adhesion …

Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico: Part 2—Realistic Hypoxia And Eutrophication, Kenneth A. Rose, Sean Creekmore, Dubravko Justić, Peter Thomas, J. Kevin Craig, Rachael Miller Neilan, Lixia Wang, Md Saydur Rahman, David Kidwell

School of Earth, Environmental, & Marine Sciences Faculty Publications

Quantifying the population-level effects of hypoxia on coastal fish species has been challenging. In the companion paper (part 1), we described an individual-based population model (IBM) for Atlantic croaker in the northwestern Gulf of Mexico (NWGOM) designed to quantify the long-term population responses to low dissolved oxygen (DO) concentrations during the summer. Here in part 2, we replace the idealized hypoxia conditions with realistic DO concentrations generated from a 3-dimensional water quality model. Three years were used and randomly arranged into a time series based on the historical occurrence of mild, intermediate, and severe hypoxia year types.We also used another …

Gw170104: Observation Of A 50-Solar-Mass Binary Black Hole Coalescence At Redshift 0.2, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, S. R. Morriss, Soma Mukherjee, Marc E. Normandin, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10 11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2-6.0+8.4M' and 19.4-5.9+5.3M (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination …

Search For Gravitational Waves Associated With Gamma-Ray Bursts During The First Advanced Ligo Observing Run And Implications For The Origin Of Grb 150906b, B. P. Abbott, Teviet Creighton, Mario C. Diaz, Joey S. Key, S. R. Morriss, Soma Mukherjee, Marc E. Normandin, Volker Quetschke, Malik Rakhmanov, Robert Stone, Darkhan Tuyenbayev, Guillermo Valdes

Physics & Astronomy Faculty Publications

We present the results of the search for gravitational waves (GWs) associated with γ-ray bursts detected during the first observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). We find no evidence of a GW signal for any of the 41 γ-ray bursts for which LIGO data are available with sufficient duration. For all γ-ray bursts, we place lower bounds on the distance to the source using the optimistic assumption that GWs with an energy of were emitted within the-Hz band, and we find a median 90% confidence limit of 71 Mpc at 150 Hz. For the subset of …

Frequency Of Nonalcoholic Fatty Liver Disease And Subclinical Atherosclerosis Among Young Mexican Americans, Clarence Gill, Kristina Vatcheva, Jen-Jung Pan, Beverly Smulevitz, David D. Mcpherson, Michael Fallon, Joseph B. Mccormick, Susan P. Fisher-Hoch, Susan T. Laing

School of Mathematical & Statistical Sciences Faculty Publications

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome, whose criteria are risk factors for atherosclerotic cardiovascular disease. We aimed to evaluate the prevalence of NAFLD, its association with subclinical atherosclerosis, and factors that may account for this association in Mexican Americans. In a population based cross-sectional sample drawn from the Cameron County Hispanic Cohort in Texas, carotid intima media thickness (cIMT), an indicator of subclinical atherosclerosis, was measured. Abnormal carotid ultrasound study was defined as mean cIMT >75th percentile for age and gender and/or plaque presence. NAFLD was defined as steatosis by ultrasound in …

Translation As A Rhetoric Of Meaning, Jose M. Davila-Montes

Writing and Language Studies Faculty Publications

From early romanticism to more recent post-structuralist and post-colonial studies, all the possibilities and impossibilities that are inherent in translation have fueled debate about authorship, intent, readership, functional equivalence, world view, the building of national literatures, power differentials, ethics, and gender issues—among many others. And, of course, about the nature of “meaning,” as the alleged sole legal tender of “all things translation.” Translation has less often been scrutinized as a form of rhetorical transaction: fundamentally, all translations are attempts, in and of themselves, to persuade their readership about some degree of correspondence with their source. However, the relationship between Translation …

Stereochemical Preference Toward Oncotarget: Design Synthesis And In Vitro Anticancer Evaluation Of Diastereomeric B-Lactams, Fabian Olazarán-Santibáñez, Debasish Bandyopadhyay, Pilar Carranza-Rosales, Gildardo Rivera, Isias Balderas-Rentería

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

Purpose: In the battle against cancer discovery of new and novel chemotherapeutic agent demands extreme obligation. Development of anticancer compounds with higher potency and reduced side-effects is timely and challenging.

Experimental Design: A small series of fourteen diastereomeric β-lactams (seven pairs) were synthesized through multi-step process exploring [2+2] ketene-imine cycloaddition as the key step. Comparative stereochemical preferences were studied through computational docking and validated by in vitro evaluation. β-tubulin was considered as possible molecular target and in vitro anticancer evaluation was conducted against SiHa, B16F10, K562 and Chang cell lines. Caspase-3 activation assay and hematoxylin/eosin staining of the cells were …

Gaming Motivations Among American College Students, Yeong Chi, Marvin Lovett, Orson Chi

Marketing Faculty Publications

The purpose of this study was to examine American college students’ motivations related to video games and to identify groups exhibiting common patterns of responses. This study investigated the video gaming motivations of American college students through the adoption of a gaming motivation scale, developed by Lafrenière, et al., which was composed of 18 Likert-typed items. A questionnaire survey, administered to 191 American college students at a public university in South Texas, was employed to collect primary data for this study. The gaming motivations of these participants were examined through factor analysis, which identified four reliable factors. Cluster analysis was …

Laminar Composite Structures For High Power Actuators, M. A. Hobosyan, P. M. Martinez, A. A. Zakhidov, C. S. Haines, R. H. Baughman, K. S. Martirosyan

Physics & Astronomy Faculty Publications

Twisted laminar composite structures for high power and large-stroke actuators based on coiled Multi Wall Carbon Nanotube (MWNT) composite yarns were crafted by integrating high-density Nanoenergetic Gas Generators (NGGs) into carbon nanotube sheets. The linear actuation force, resulting from the pneumatic force caused by expanding gases confined within the pores of laminar structures and twisted carbon nanotube yarns, can be further amplified by increasing NGG loading and yarns twist density, as well as selecting NGG compositions with high energy density and large-volume gas generation. Moreover, the actuation force and power can be tuned by the surrounding environment, such as to …

How Many More? Sample Size Determination In Studies Of Morphological Integration And Evolvability, Mark Grabowski, Arthur Porto

School of Medicine Publications

1. The variational properties of living organisms are an important component of current evolutionary theory. As a consequence, researchers working on the field of multivariate evolution have increasingly used integration and evolvability statistics as a way of capturing the potentially complex patterns of trait association and their effects over evolutionary trajectories. Little attention has been paid, however, to the cascading effects that inaccurate estimates of trait covariance have on these widely used evolutionary statistics.

2. Here, we analyze the relationship between sampling effort and inaccuracy in evolvability and integration statistics calculated from 10-trait matrices with varying patterns of covariation and …

Time Dependent Solution For An Incompressible Viscous Fluid Flow In A Cavity, Bishnu Parajuli

Theses and Dissertations

The Finite Element Method is used to find the time dependent solution for an incompressible viscous fluid flow in a cavity in two dimension. The governing equations for this system are the continuity equation and the momentum equation. We use finite element method to obtain the dependent variables. Here we derive weak formulation and develop finite element model by using Galerkin Method. Then we compute velocity components of the fluid for a square cavity. The numerical results are presented.

Multi-Type Branching Processes Model Of Nosocomial Epidemic, Zeinab Nageh Mohamed

Theses and Dissertations

The potency of an infectious disease to spread between different types of susceptible individuals in a hospital determines the fate of controlling nosocomial epidemics. I use a multi-type branching process with a joint negative binomial offspring distribution to study nosocomial epidemics. In particular, I estimate the basic reproduction number R0 and study its relationship with the offspring distribution’s parameters at different and fixed number of generations. Also, I study the effect of contact tracing on estimates of R0.

Assessment Of Long-Term Effects Of Woody Plants Expansion In Humid, Tropical Grassland Of Venezuela, Soraya A. Delgado

Theses and Dissertations

The invasion of woody plants into grassland communities, or shrub encroachment, is a worldwide phenomenon usually attributed to anthropogenic interference. Most studies have focused on temperate and arctic biomes. Less is known about how shrub encroachment is affecting humid tropical grasslands, which have different climates, higher levels of biodiversity and different histories of human land use. This project quantifies the rate of woody vegetation change in a humid tropical grassland of Venezuela using remote sensing over the past quarter century and ground based measurements of selected individual species. Results of remote sensing indicate high rates of conversion of grasslands to …

Parameterization Of Ar231453: A Potent Agonist Of The Gpr119 Receptor, A Target For Diabetes Treatment, John E. Hamilton

Theses and Dissertations

The first reported potent agonist for the GPR119 receptor, a potential target for the treatment of diabetes, is 2-fluoro-4-methanesulfonyl-phenyl-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine (AR231453). The dynamic interactions of AR231453 with GPR119 using molecular dynamics simulation are of great interest. However, parameters for AR231453 that describe the behavior of the molecule in the CHARMM force field have not been determined. The following study produces parameters by creating model fragments and compares the produced parameters to quantum calculations. The produced parameters are then further refined within the Visual Molecular Dynamics (VMD) program’s plugin program, the Force Field Toolkit as well as Gaussian 09 and CHARMM. Molecular …

Nature, Essence And Spirit: An Artistic Process Of Space, Lines And Color From The Level Of Cells To The Large Oceanic Water World, Odra O. Arriaga

Theses and Dissertations

The methods, experimentations, philosophies and influential artists mentioned in this thesis all form part of my artistic exploration and art from the level of cells to the large oceanic water world. As an artist of Fine Arts at the University of Texas, Rio Grande Valley, my main emphasis is to associate these concepts with my personal experiences, cultural traditions and artistic perspectives with my likes for lines, colors and spaces in what I called, Nature, Essence and Spirit. Furthermore, my artistic approach was mostly influenced by the views of artists such as, Vasily Kandinsky, Frank Stella, Piet Mondrian, Paul Klee, …

A New Approach To Ramanujan's Partition Congruences, Mayra C. Huerta

Theses and Dissertations

MacMahon provided Ramanujan and Hardy a table of values for p(n) with the partitions of the first 200 integers. In order to make the table readable, MacMahon grouped the entries in blocks of five. Ramanujan noticed that the last entry in each block was a multiple of 5. This motivated Ramanujan to make the following conjectures, p(5n+4) ≡ 0 (mod 5); p(7 n+5) ≡ 0 (mod 7); p(11n+6) ≡ 0 (mod 11) which he eventually proved.

The purpose of this thesis is to give new proofs for Ramanujan's partition …

Applications Of Side Scan And Parametric Echosounders For Mapping Shallow Seagrass Habitats And Their Associated Organic Carbon, Austin L. Greene

Theses and Dissertations

Despite a global valuation of $1.9 trillion seagrass habitats world-wide are in decline—directly impacting the large soil carbon stocks associated with seagrasses. Many methods exist to measure the health of seagrass habitats, yet few apply to shallow coastal ecosystems. Those that do lack spatial resolution (satellite surveys) or do not provide continuous data across large areas (point-based surveys). Furthermore, carbon content of these ecosystems is largely limited to destructive and time-consuming soil core sampling. Side scan and parametric acoustics represent a unique technological opportunity to study habitat coverage and carbon content of vegetated coastal habitats (< 3 m depth). This study presents proof of concept for applications of recreational side scan and parametric sub-bottom profiling sonars in mapping both habitat coverage and organic carbon distribution in shallow seagrass habitats, and explores how these methods might be improved in future applications.

Investigating The Mathematical Dispositions And Self-Efficacy For Teaching Mathematics Of Preservice Teachers, Jasmine M. Cruz

Theses and Dissertations

The study of the individual's beliefs and the role and influence they have on the individual's actions and behaviors, have long been examined and investigated by educators and psychologists. Moreover, researchers have overwhelmingly claimed and demonstrated that the beliefs held by teachers significantly influences their behavior and educational practices in the classroom. This thesis study investigates the mathematical disposition and self-efficacy for teaching mathematics of preservice teachers. The study's primary goals are to discover if there is a relationship or association between a teacher's mathematical disposition(MD) and his/her self-efficacy for teaching mathematics (SEFTM), and if there are significant differences between …

Decomposition Of Black Mangrove (Avicennia Germinans ) Leaf Litter: Calibrating Estuarine Indicators Of Functional Recovery, Leticia Martinez Contreras

Theses and Dissertations

Decomposition of plant material produced by mangroves and other macrophytes in estuaries occurs in both sediments and the water column. Early and intense processing could be more common in the water. In a previous study, in situ decomposition rates of Black Mangrove (Avicennia germinans ) leaf litter suspended in the water column differed among three estuaries in south Texas with moderate differences in salinity, water temperature, available nitrogen (N), and tidal flow. A series of microcosm experiments were conducted to determine the influence, within observed ranges in the estuaries, of these water variables on mass loss of Black Mangrove …

Problem Book On Higher Algebra And Number Theory, Ryanto Putra

Theses and Dissertations

This book is an attempt to provide relevant end-of-section exercises, together with their step-by-step solutions, to Dr. Zieschang's classic class notes Higher Algebra and Number Theory. It's written under the notion that active hands-on working on exercises is an important part of learning, whereby students would see the nuance and intricacies of a math concepts which they may miss from passive reading. The problems are selected here to provide background on the text, examples that illuminate the underlying theorems, as well as to fill in the gaps in the notes.

Mathematical Modeling Of Mers-Cov Nosocomial Epidemic, Adriana Quiroz

Theses and Dissertations

This thesis concerns about the analysis and modeling of spread of an infectious disease inside a hospital. We begin from the basic knowledge of the simple models: SIR and SEIR, to show an appropriate understanding of the epidemic dynamic process. We consider the Middle East Respiratory Syndrome Corona Virus (MERS-CoV), in Saudi Arabia, to introduce MERS-CoV SEIR ward model by developing different systems of equations in each ward (unit). We use the Next Generation Matrix method to calculate the basic reproduction number R0. Simulations of different scenarios are done using different combination of parameters.

To model MERS-CoV we established …

Disease Modeling Using Fractional Differential Equations And Estimation, Daniel P. Medina

Theses and Dissertations

Ordinary differential equations has been the most conventional approach when modeling spread of infectious diseases. Effective research has shown that using fractional-order differentiation can be a very useful and efficient extension for some mathematical models. In this thesis, fractional calculus is used to depict an SEIR model with a system of fractional-order differential equations. I also simulate the fractional-order SEIR using integer-order numerical methods. I also establish the estimation framework and show that it is accurately working.

Coupled Telegraph And Sir Model Of Information And Diseases, Jose De Jesus Galarza

Theses and Dissertations

In this work, the effect of information propagation on disease spread and vaccination uptake through networks is studied. In this model the information reaches different people at different distances from the center of information containing the health data. We use a pair of Telegraph equations to depict the vaccine and disease information propagation on a network embedded into a straight line. The Telegraph equation is coupled with an SIR (Susceptible-Infected-Recovered) model to examine the anticipated mutual influence. Numerical simulations and stability analysis were made to study the model. We show how the propagation of information about the disease impacts the …

Examining Culture And Gender Roles In Latina Undergraduate Participation In Stem At Utrgv, Stephanie Garza

Theses and Dissertations

The study was designed to examine the role of familism and gender role beliefs on Latina pursuit of a degree in Science, Technology, Engineering, and Math (STEM) fields. This study surveyed Latino/a undergraduate students at the University of Texas-Rio Grande Valley to determine the influence of socioeconomic status, familism and gender role beliefs on pursuit of careers in STEM. Participants completed a demographic questionnaire, the Pan-Hispanic Familism scale, the Attitudinal Familism scale and the Gender Role Beliefs scale. Findings revealed how major selection and pursuit of STEM is affected by students’ income level, familism, gender, and gender role beliefs. Results …