Digital Commons Network^™

Self-Esteem And Identity: A Case Study Of Two Bilingual Education Students, Julia Gomez Montalvo

Theses and Dissertations - UTB/UTPA

This qualitative study focused on the self-esteem, sociocultural identity, and academic performance of transitional and dual language students as they moved through their respective programs. A case study was conducted on two randomly selected students, one from the transitional program and one from the dual language program. The two students attend the same school and have participated in their respective programs for 12 years in the same school district. Both students were asked to complete surveys on self-esteem and participate in an interview where they were asked various questions about their self-esteem, sociocultural identity, and academic performance. Data collected from …

Synthesis And Upconversion Spectroscopy Of Yb Er Doped M2o2s (M = La, Gd, Y) Phosphors, G. A. Kumar, Madhab Pokhrel, Dhiraj K. Sardar, Alejandrina Martinez

Physics & Astronomy Faculty Publications

Yb and Er doped M2O2S (M = Y, Gd, La) phosphor was synthesized by solid state flux fusion method and their up conversion spectral properties were studied as a function different Yb concentrations. The solid state flux fusion results in well crystallized hexagonal shaped phosphor particles of average size 4–6 μm. Upconversion spectral studies shows that all the compositions are stronger in green emission with the green emission intensity 1.7 times than the red in composition Gd2O2S:Yb(8)Er(1), Y2O2S:Yb(9)Er(1), La2O2S:Yb(3)Er(7) (All mol%). The internal upconversion efficiency for the green emission bands was calculated to be 74, 62, 100% respectively in …

K-Nearest Keyword Search In Rdf Graphs, Eugenio De Hoyos

Theses and Dissertations - UTB/UTPA

We formulate and tackle a flexible and useful query, namely k-nearest keyword (k-NK) query, which can identify the relationship between vertices (or keywords) in an RDF graph, where users are only required to specify two query keywords q and w (without knowing the domain knowledge). In particular, a k-NK query returns k closest pairs of vertices (ui; vi) in the RDF graph such that vertices ui and vi contain keywords q and w, respectively, and vi has the smallest (shortest path) distance to ui (i.e., vi is the nearest neighbor of ui). In order to efficiently answer k-NK queries, in …

The Value Of Literary Journalism: Searching For Truths Through An Objective/Subjective Dialectic, Omar Rodriguez

Theses and Dissertations - UTB/UTPA

Literary Journalism is a hybrid genre that combines literary devices with advanced journalistic techniques to create nonfiction narratives. The distinctive qualities of literary journalism, working in addition to so-called objective approaches of conventional journalism, provide the reader with an alternative observation of specific social phenomena. In the introduction, issues revolving around the genre will be discussed followed by the introduction of the objective/subjective dialectic thus formulating my thesis that insists combining the two approaches allows the reader to see truth beyond ideology. The three chapters that follow offer readings of three key and representative works of literary journalism. The Armies …

Qualitative Analysis Of The Burgers-Huxley Equation, Jing Tian

Theses and Dissertations - UTB/UTPA

There are many well-known techniques for obtaining exact solutions of differential equations, but some of them only work for a very limited class of problems and are merely special cases of a few power symmetry methods. These approaches can be applied to nonlinear differential of unfamiliar type; they do not rely on special “tricks." Instead, a given differential equation can be made to reveal its symmetries, which are then used to construct exact solutions. In this thesis, we briefly present the theory of the Lie symmetry method for finding exact solutions of nonlinear differential equations, then apply it to the …

A History Of The Texas Education Agency Instructional Facility Allotment (Ifa) Program In Hidalgo County School Districts Located In The Texas Rio Grande Valley From 1997 To 2007, Michael J. Sandroussi

Theses and Dissertations - UTB/UTPA

This study examines the implementation of the Texas Education Agency (TEA) Instructional Facility Allotment (IFA) Program in the Rio Grande Valley (RGV) through documentation chronicling Hidalgo County school districts from 1997 through 2007 that secured IFA & EDA monies to build new facilities. Participants in this study included Hidalgo County school districts, three school architects, ten Hidalgo County school district superintendents and one Texas state senator. The fifteen school district superintendents were asked to complete an Instructional Facility Allotment (IFA) and Existing Debt Allotment (EDA) survey. The three architects, ten superintendents and state senator were interviewed in order to provide …

Development And Testing Of An Actively Adjustable Stiffness Mechanism, Eleazar Marquez, Robert Freeman, Horacio Vasquez

Mechanical Engineering Faculty Publications

This study presents the comparison of the theoretical and experimental results of the performance of an adjustable stiffness mechanism. In particular, the use of redundant actuation is emphasized in the design of a one degree-of-freedom Watt II mechanism capable of independently controlling the effective stiffness without a change in equilibrium position. This approach is in contrast to spring mechanism designs unable to actively control the spring rate independent of deflection, and with potential applications in various types of suspension and assembly systems. Results indicate that two direct drive brush-type direct current motors are required to drive the redundantly actuated mechanism …

The Collegian (2012-04-30), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64, No. 29

The Pan American (2012-04-26), Reynaldo Leal, Nadia Tamez-Robledo

UTPA Archives - The Pan American Newspaper

Vol. 68, No. 27

Communication: Adjusting Charge Transfer State Energies For Configuration Interaction Singles: Without Any Parameterization And With Minimal Cost, Xinle Liu, Shervin Fatehi, Yihan Shao, Brad S. Veldkamp, Joseph Subotnik

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

In a recent article, we showed that configuration interaction singles (CIS) has a systematic bias against charge-transfer (CT) states: CT vertical excitation energies are consistently too high (by 1-2 eV) as compared with non-CT energies [J. E. Subotnik, J. Chem. Phys. 137, 071104 (2011)]. We now show that this CIS error can be corrected approximately by performing a single Newton- Raphson step to reoptimize orbitals, thus establishing a new set of orbitals which better balances ground and excited state energies. The computational cost of this correction is exactly that of one coupled-perturbed Hartree-Fock calculation, which is effectively the cost of …

In An Expanding Universe, What Doesn’T Expand?, Richard H. Price, Joseph D. Romano

Physics & Astronomy Faculty Publications

The expansion of the universe is often viewed as a uniform stretching of space that would affect compact objects such as atoms and stars, as well as the separation of galaxies. One usually hears that bound systems do not take part in the general expansion, but a much more subtle question is whether bound systems expand partially. In this paper, a definitive answer is given for a very simple system: a classical “atom” bound by electrical attraction. With a mathematical description appropriate for undergraduate physics majors, we show that this bound system either completely follows the cosmological expansion, or, after …

Sorption Kinetic Study Of Selenite And Selenate Onto A High And Low Pressure Aged Iron Oxide Nanomaterial, Christina M. Gonzalez, Jeffrey Hernandez, Jose R. Peralta-Videa, Cristian E. Botez, Jason Parsons, Jorge L. Gardea-Torresdey

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

The sorption of selenite (SeO32−) and selenate (SeO42−) onto Fe3O4 nanomaterials produced by non microwave-assisted or microwave-assisted synthetic techniques was investigated through use of the batch technique. The phase of both synthetic nanomaterials was determined to be magnetite by X-ray diffraction. The average grain sizes of non microwave-assisted and microwave-assisted synthetic Fe3O4 were determined to be 27 and 25 nm, respectively through use of the Scherrer's equation. Sorption of selenite was pH independent in the pH range of 2-6, while sorption of selenate decreased at pH 5 and 6. The addition of Cl− had no significant effect on selenite or …

Identification Of Common Variants Associated With Human Hippocampal And Intracranial Volumes, Jason L. Stein, Anderson M. Winkler, Laura Almasy, Joanne E. Curran, Marcio Almeida, Ravi Duggirala, Thomas D. Dyer, Harald H. H. Goring, Matthew P. Johnson, John Blangero

School of Medicine Publications

Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer's disease and is reduced in schizophrenia, major depression and mesial temporal lobe epilepsy. Whereas many brain imaging phenotypes are highly heritable, identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 …

The Collegian (2012-04-09), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64, No. 26

Implementation And Testing Of The First Prompt Search For Gravitational Wave Transients With Electromagnetic Counterparts, J. Abadie, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods. During two observing periods (Dec. 17, 2009 to Jan. 8, 2010 and Sep. 2 to Oct. 20, 2010), a low-latency analysis pipeline was used to identify …

Utb/Tsc Commencement – Spring 2012, University Of Texas At Brownsville, Texas Southmost College

Brownsville Archives - Legacy Commencement Programs

No abstract provided.

Utpa Commencement – Spring 2012, University Of Texas-Pan American

Edinburg Archives - Legacy Commencement Programs

No abstract provided.

Orange & White - Spring 2012, University Of Texas At Brownsville

UTB/TSC Archives - Orange & White Magazine

No abstract provided.

Electrocardiographic Abnormalities Among Mexican Americans: Correlations With Diabetes, Obesity, And The Metabolic Syndrome, Saulette R. Queen, Beverly Smulevitz, Anne R. Rentfro, Kristina Vatcheva, David D. Mcpherson, Susan P. Fisher-Hoch, Joseph B. Mccormick, Susan T. Laing

School of Mathematical & Statistical Sciences Faculty Publications

Background: Resting ischemic electrocardiographic abnormalities have been associated with cardiovascular mortality. Simple markers of abnormal autonomic tone have also been associated with diabetes, obesity, and the metabolic syndrome in some populations. Data on these electrocardiographic abnormalities and correlations with coronary risk factors are lacking among Mexican Americans wherein these conditions are prevalent.

Objective: This study aimed to evaluate the prevalent resting electrocardiographic abnormalities among community-dwelling Mexican Americans, and correlate these findings with coronary risk factors, particularly diabetes, obesity, and the metabolic syndrome.

Methods: Study subjects (n=1280) were drawn from the Cameron County Hispanic Cohort comprised of community-dwelling Mexican Americans living …

Polystyrenesulfonate-Catalyzed Synthesis Of Novel Pyrroles Through Paal-Knorr Reaction, Mandira Banik, Bianca Ramirez, Ashwini Reddy, Debasish Bandyopadhyay, Bimal K. Banik

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

Background: The classical Paal-Knorr reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful pyrrole derivatives.

Results: Polystyrenesulfonate-catalyzed simple synthesis of substituted pyrroles following Paal-Knorr reaction has been accomplished with an excellent yield in aqueous solution. This method also produces pyrroles with multicyclic polyaromatic amines.

Conclusions: The present procedure for the synthesis of N-polyaromatic substituted pyrroles will find application in the synthesis of potent biologically active molecules.

The Creation And Propagation Of Radiation: Fields Inside And Outside Of Sources, Stanislaw Olbert, John Belcher, Richard H. Price

Physics & Astronomy Faculty Publications

We present an algorithm for computing the electromagnetic fields due to currents inside and outside of finite sources with a high degree of spatial symmetry for arbitrary time-dependent currents. The solutions for these fields do not involve the time derivatives of the currents but involve only the currents and their time integrals. We give solutions for moving planar sheets of charge, and a rotating spherical shell carrying a uniform charge density. We show that the general solutions reduce to the standard expressions for magnetic dipole radiation for slow time variations of the currents. If the currents are turned on very …

Structural Basis For Ca 2+-Induced Activation And Dimerization Of Estrogen Receptor Alpha By Calmodulin, Yonghong Zhang, Zhigang Li, David B. Sacks, James B. Ames

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

The estrogen receptor α (ER-α) regulates expression of target genes implicated in development, metabolism, and breast cancer. Calcium-dependent regulation of ER-α is critical for activating gene expression and is controlled by calmodulin (CaM). Here, we present the NMR structures for the two lobes of CaM each bound to a localized region of ER-α (residues 287–305). A model of the complete CaM·ER-α complex was constructed by combining these two structures with additional data. The two lobes of CaM both compete for binding at the same site on ER-α (residues 292, 296, 299, 302, and 303), which explains why full-length CaM binds …

Utb/Tsc Admissions Brochure - Knowledge Knows No Boundaries, University Of Texas At Brownsville And Texas Southmost College. Office Of News And Information

UTB/TSC Archives - Factbooks & Brochures

No abstract provided.

The Pan American (2012-03-08), Reynaldo Leal, Nadia Tamez-Robledo

UTPA Archives - The Pan American Newspaper

Vol. 68, No. 21

A Microwave-Assisted Bismuth Nitrate-Catalyzed Unique Route Toward 1,4-Dihydropyridines, Debasish Bandyopadhyay, Stephanie Maldonado, Bimal K. Banik

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

The classical Hantzsch reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful 1,4-dihydropyridine derivatives. Bismuth nitrate pentahydrate under microwave irradiation is proven to act as a very efficient catalyst for a one-pot, three-component synthesis of 1,4-dihydropyridines in excellent yields from diverse amines/ammonium acetate, aldehydes and 1,3-dicarbonyl compounds within 1-3 min under solvent-free conditions. The present environmentally benign procedure for the synthesis of 1,4-dihydropyridines is suitable for library synthesis and it will find application in the synthesis of potent biologically active molecules. The excellent yield and extreme rapidity of the method …

The Collegian (2012-03-05), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64, No. 23

Comparative Studies Of The Spectroscopic Properties Of Nd3+: Yag Nanocrystals Transparent Ceramic And Single Crystal, M. Pokhrel, N. Ray, G. A. Kumar, D. K. Sardar

Physics & Astronomy Faculty Publications

Detailed comparative spectroscopic studies of Nd3+ doped YAG nanocrystals, transparent ceramic and single crystal have been performed. Although most of the radiative spectral properties of Nd3+ are almost in good agreement between the three hosts, the non-radiative losses are significantly high in nanocrystals, which are attributed due to the presence of large amount of hydroxyl groups on the nanocrystals surface which deteriorates the quality of the material for laser applications. In addition, wavelength dependent scattering loss for the Nd3+ doped YAG nanocrystals is found significantly high compared to those of Nd3+ doped single crystal and ceramic. © 2012 Optical Society …

Processing Quality Of Potato Tubers Produced During Autumn And Spring And Stored At Different Temperatures, Sergio T. De Freitas, Engil Isadora Pujol Pereira, Ana Cecilia S. Gomez, Auri Brackmann, Fernando Nicoloso, Dilson A. Bisognin

School of Earth, Environmental, & Marine Sciences Faculty Publications

The objective of this work was to access processing quality of potato clones (Solanum tuberosum) Asterix, SMINIA793101-3, and Missaukee cultivated during spring and autumn growing seasons and stored at 4, 8, 12, or 25ºC. Clones grown in spring had shorter dormancy than clones grown in autumn. Potato tubers grown in spring and autumn and stored at 4ºC, as well as tubers grown in autumn and stored at 8ºC had no sprouting for six months. Among clones grown in autumn, the longest dormancy period during storage at 12ºC was observed in the clone SMINIA793101-3, and at 25ºC was in the clone …

Air Pollution And Acute Respiratory Response In A Panel Of Asthmatic Children Along The U.S.–Mexico Border, Stefanie E. Sarnat, Amit U. Raysoni, Wen-Whai Li, Fernando Holguin, Brent A. Johnson, Silvia Flores Luevano, Jose Humberto Garcia, Jeremy A. Sarnat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Background: Concerns regarding the health impact of urban air pollution on asthmatic children are pronounced along the U.S.–Mexico border because of rapid population growth near busy border highways and roads.

Objectives: We conducted the first binational study of the impacts of air pollution on asthmatic children in Ciudad Juarez, Mexico, and El Paso, Texas, USA, and compared different exposure metrics to assess acute respiratory response.

Methods: We recruited 58 asthmatic children from two schools in Ciudad Juarez and two schools in El Paso. A marker of airway inflammation [exhaled nitric oxide (eNO)], respiratory symptom surveys, and pollutant measurements (indoor and …

The Collegian (2012-02-27), Rene Cardona Jr.

UTB/TSC Archives - The Collegian [Newspaper]

Vol. 64, No. 22