Physical Sciences and Mathematics Commons^™

Search For Gravitational Waves From Intermediate Mass Binary Black Holes, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present the results of a weakly modeled burst search for gravitational waves from mergers of nonspinning intermediate mass black holes in the total mass range 100-450M and with the component mass ratios between 11 and 41. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the intermediate mass black holes mergers as a function of the component masses. In the most efficiently detected bin centered on 88+88M, for nonspinning sources, the rate density …

Polyvinylchloride-Single-Walled Carbon Nanotube Composites: Thermal And Spectroscopic Properties, Mircea Chipara, Jessica Cruz, Edgar R. Vega, Jorge Alarcon, Thomas Mion, Dorina M. Chipara, Elamin Ibrahim, Steven C. Tidrow, David Hui

Physics & Astronomy Faculty Publications

Nanocomposites of single-walled carbon nanotubes dispersed within polyvinylchloride have been obtained by using the solution path. High-power sonication was utilized to achieve a good dispersion of carbon nanotubes. Thermogravimetric analysis revealed that during the synthesis, processing, or thermal analysis of these nanocomposites the released chlorine is functionalizing the single-walled carbon nanotubes. The loading of polyvinylchloride by single-walled carbon nanotubes increases the glass transition temperature of the polymeric matrix, demonstrating the interactions between macromolecular chains and filler. Wide Angle X-Ray Scattering data suggested a drop of the crystallite size and of the degree of crystallinity as the concentration of single-walled carbon …

Border Hispanics’ Physical Activity Improvement In A Chronic Disease Prevention Program, Lu Xu

Theses and Dissertations - UTB/UTPA

In seeking of effective prevention programs to improve physical activities, we want to examine the factors related to physical activities improvement in Alliance for a Healthy Border, a chronic disease prevention program with pre-post-post evaluations through 12 federally qualified community health centers serving primarily Hispanics in communities along the U.S.- Mexico border. Logistic regression was performed to examine the association between physical activity and twenty predictors at baseline. Multinomial regression was used to examine the determinants of physical activities improvement at two time points: program end and post six-months. Socio-demographic, baseline health condition factors, and determination of doing physical activity …

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 …

Utpb: A Benchmark For Scientific Workflow Provenance Storage And Querying Systems, Carlos F. Gomez

Theses and Dissertations - UTB/UTPA

A crucial challenge for scientific workflow management systems is to support the efficient and scalable storage and querying of large provenance datasets that record the history of in silico experiments. As new provenance management systems are being developed, it is important to have benchmarks that can evaluate these systems and provide an unbiased comparison. In this paper, based on the requirements for scientific workflow provenance systems, we design an extensible benchmark that features a collection of techniques and tools for workload generation, query selection, performance measurement, and experimental result interpretation.

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 …

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 …

Development Of An Assay To Screen For Novel Proteins From Bacillus Thuringiensis With Antibacterial Activity, Auriole T. Tamegnon

Theses and Dissertations - UTB/UTPA

Bacillus thuringiensis (Bt) produces the non specific Cyt protein and the specific Cry protein. Past research has shown these proteins are toxic to insects, red blood cells, cancer cells, and some bacteria. While many antibacterial substances are known to exist, efforts to find new ones still continue. In this project we used Bt 6-2-56 (containing a novel filament associated parasporal body which appears non-toxic to insects and protozoan) and Bt 4Q13 (which has been shown to have activity against E. coli and S. aureus) to develop a simple, easy, scalable assay in a 96 well Microtitre plate to look for …

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 …

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 …

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 …

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 …

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 …

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 …

Quantum Mechanics Entropy And A Quantum Version Of The H-Theorem, Paul Bracken

School of Mathematical & Statistical Sciences Faculty Publications

No abstract provided.

Hysteresis And Relaxation In Granular Permanent Magnets, Ralph Skomski, B. Balamurugan, Tom A. George, Mircea Chipara, Xiao-Hui Wei, Jeff E. Shield, D. J. Sellmyer

Physics & Astronomy Faculty Publications

Some nontrivial aspects of the magnetic and structural characterization of hard-magnetic nanoparticles are investigated. Dilute ensembles are well-described by mean-field theory, although there is an asymmetry between exchange and magnetostatic interaction fields. Corrections to the mean-field approximation are caused by cooperative effects and have the character of Onsager reaction fields, which are much stronger in micromagnetism than in atomic-scale magnetism. The slow dynamics of zero-field-cooled (ZFC) magnetization curves is strongly affected by the particles0 magnetic anisotropy, which reduces the corresponding energy-barrier height from 25 to 19.1 kBT.

A Comprehensive Method For Fractionating Soil Organic Matter Not Protected And Protected From Decomposition By Physical And Chemical Mechanisms, César Plaza, José M. Fernández, Engil Isadora Pujol Pereira, Alfredo Polo

School of Earth, Environmental, & Marine Sciences Faculty Publications

The objective of this work was to describe a method for isolating meaningful and measurable soil organic matter (SOM) pools that differ in the mechanisms by which they are protected from decomposition. The proposed method is appropriate for soil C stabilization and sequestration studies. Unlike previous fractionation schemes, this procedure allows free SOM located between aggregates (unprotected C pool) and SOM occluded within both macroaggregates and microaggregates (C weakly and strongly protected by physical mechanisms, respectively) to be recovered separately, freed from the soil mineral matrix and the mineral-associated SOM pool (C pool protected by chemical mechanisms) and thus well …

Phenotypic Characterization And 16s Rdna Identification Of Culturable Non-Obligate Halophilic Bacterial Communities From A Hypersaline Lake, La Sal Del Rey, In Extreme South Texas (Usa), Kristen Phillips, Frederic Zaidan, Omar R. Elizondo, Kristine L. Lowe

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

Background

La Sal del Rey ("the King's Salt") is one of several naturally-occurring salt lakes in Hidalgo County, Texas and is part of the Lower Rio Grande Valley National Wildlife Refuge. The research objective was to isolate and characterize halophilic microorganisms from La Sal del Rey. Water samples were collected from the lake and a small creek that feeds into the lake. Soil samples were collected from land adjacent to the water sample locations. Sample salinity was determined using a refractometer. Samples were diluted and cultured on a synthetic saline medium to grow halophilic bacteria. The density of halophiles was …

Subnormality Of Aluthge Transforms Of Weighted Shifts, Sang Hoon Lee, Woo Young Lee, Jasang Yoon

School of Mathematical & Statistical Sciences Faculty Publications

In this note we study the k-hyponormality and the subnormality of Aluthge transforms of weighted shifts. It is shown that Aluthge transforms of weighted shifts need not preserve the k-hyponormality. Moreover, we show that if W α is a subnormal weighted shift with 2-atomic Berger measure then its Aluthge transform W̃ α is subnormal if and only if at least one of two atoms is zero. © 2011 Springer Basel AG.

Subnormality For Arbitrary Powers Of 2-Variable Weighted Shifts Whose Restrictions To A Large Invariant Subspace Are Tensor Products, Raúl E. Curto, Sang Hoon Lee, Jasang Yoon

School of Mathematical & Statistical Sciences Faculty Publications

The Lifting Problem for Commuting Subnormals (LPCS) asks for necessary and sufficient conditions for a pair of subnormal operators on Hilbert space to admit commuting normal extensions. We study LPCS within the class of commuting 2-variable weighted shifts T≡(T1, T2) with subnormal components T1 and T2, acting on the Hilbert space ℓ2(Z+2) with canonical orthonormal basis {e(k1,k2)}k1,k2≥0. The core of a commuting 2-variable weighted shift T, c(T), is the restriction of T to the invariant subspace generated by all vectors e(k1,k2) with k1, k2≥1; we say that c(T) is of tensor form if it is unitarily equivalent to a shift …

Observability Of Pulsar Beam Bending By The Sgr A* Black Hole, K. Stovall, Teviet Creighton, Richard H. Price, Fredrick A. Jenet

Physics & Astronomy Faculty Publications

According to some models, there may be a significant population of radio pulsars in the Galactic center. In principle, a beam from one of these pulsars could pass close to the supermassive black hole (SMBH) at the center, be deflected, and be detected by Earth telescopes. Such a configuration would be an unprecedented probe of the properties of spacetime in the moderate- to strong-field regime of the SMBH. We present here background on the problem, and approximations for the probability of detection of such beams. We conclude that detection is marginally possible with current telescopes, but that telescopes that will …

All-Sky Search For Periodic Gravitational Waves In The Full S5 Ligo Data, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Malik Rakhmanov, Volker Quetschke, Joseph D. Romano

Physics & Astronomy Faculty Publications

We report on an all-sky search for periodic gravitational waves in the frequency band 50-800Hz and with the frequency time derivative in the range of 0 through -6×10-9Hz/s. Such a signal could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. After recent improvements in the search program that yielded a 10× increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational-wave strain to date. Near 150Hz our upper limit on worst-case linearly polarized strain …

Identifying Risk Factors For Disparities In Breast Cancer Mortality Among African-American And Hispanic Women, Nancy Tian, Pierre Goovaerts, F. Benjamin Zhan, T. Edwin Chow, Jeff Gaines Wilson

School of Earth, Environmental, & Marine Sciences Faculty Publications

Background: This study evaluated the risk factors associated with racial disparities in female breast cancer mortality for African-American and Hispanic women at the census tract level in Texas from 1995 to 2005.

Methods: Data on female breast cancer cases were obtained from the Texas Cancer Registry. Socioeconomic and demographic data were collected from Census 2000. Network distance and driving times to mammography facilities were estimated using Geographic Information System techniques. Demographic, poverty and spatial accessibility factors were constructed using principal component analysis. Logistic regression models were developed to predict the census tracts with significant racial disparities in breast cancer mortality …

Effects Of Hypoxia Exposure On Hepatic Cytochrome P450 1a (Cyp1a) Expression In Atlantic Croaker: Molecular Mechanisms Of Cyp1a Down-Regulation, Md. Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hypoxia-inducible factor-α (HIF-α) and cytochrome P450 1A (CYP1A) are biomarkers of environmental exposure to hypoxia and organic xenobiotic chemicals that act through the aryl hydrocarbon receptor, respectively. Many aquatic environments heavily contaminated with organic chemicals, such as harbors, are also hypoxic. Recently, we and other scientists reported HIF-α genes are upregulated by hypoxia exposure in aquatic organisms, but the molecular mechanisms of hypoxia regulation of CYP1A expression have not been investigated in teleost fishes. As a first step in understanding the molecular mechanisms of hypoxia modulation of CYP1A expression in fish, we characterized CYP1A cDNA from croaker liver. Hypoxia exposure …