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Articles 1711 - 1740 of 2419

Full-Text Articles in Physical Sciences and Mathematics

Efficient Query Processing Over Uncertain Road Networks, Bamikole A. Ogundele May 2015

Efficient Query Processing Over Uncertain Road Networks, Bamikole A. Ogundele

Theses and Dissertations - UTB/UTPA

One of the fundamental problems on spatial road networks has been the shortest traveling time query, with applications such as location-based services (LBS) and trip planning. Algorithms have been made for the shortest time queries in deterministic road networks, in which vertices and edges are known with certainty. Emerging technologies are available and make it easier to acquire information about the traffic. In this paper, we consider uncertain road networks, in which speeds of vehicles are imprecise and probabilistic. We will focus on one important query type, continuous probabilistic shortest traveling time query (CPSTTQ), which retrieves sets of objects that …


Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo May 2015

Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo

Theses and Dissertations - UTB/UTPA

The Anterior Cruciate Ligament (ACL) is the most common knee injury in the United States; roughly 150,000 ACL surgeries are performed annually. The ACL lacks self-healing properties due to its location inside the knee’s intra – articular environment (IA). Treatments for ACL ruptures involve the use of autogenous grafts or allografts. More suitable treatments can be found in new bio engineered tissue scaffolds, composed of natural and synthetic polymers. The polymers provide stronger mechanical properties and the ability to promote cell adhesion. It is believed that mimicking the crimping pattern of human ligaments will enhance polymer properties. Four polymers were …


Use Of A Simulated Directional Social Network To Compare Measures Of User Influence, Jose G. Villarreal Jr. May 2015

Use Of A Simulated Directional Social Network To Compare Measures Of User Influence, Jose G. Villarreal Jr.

Theses and Dissertations - UTB/UTPA

This paper proposes a new method for measuring user influence in directional social networks, derived from the works of Reilly et al. and Cha et al. The method being proposed in this paper considers an element from each of the two works. The first is the ratio of ‘messages forwarded’ over ‘messages posted’. The second element is the size of the audience. The second part of this study entails modeling and simulating an online social network. Using a data sample from the Twitter network to implement the simulation, it is going to allow us to compare the methods that are …


Complex Short Pulse Equation And Its Integrable Discretizations, Raul M. Guajardo May 2015

Complex Short Pulse Equation And Its Integrable Discretizations, Raul M. Guajardo

Theses and Dissertations - UTB/UTPA

In this thesis, we are mainly concerned with the complex short pulse (CSP) equation which was proposed in Physica D [1]. We present the Lax pair of the CSP equation and show the compatibility condition gives the CSP equation. Therefore, the integrability is confirmed. Then, a set of bilinear equations is proposed which yields the CSP equation through the hodograph transformation. Based on the bilinear form, general N-soliton solution is given in determinant form. Regarding two-soliton solution, a bound state can be formed if the velocities of two solitons are equal. Furthermore, a semi- and fully discrete analogues are constructed …


Oxidation Of Dibenzothiophene To Dibenzothiophene-Sulfone Using Molybdenum (Vi) Oxide, Tungsten (Vi) Oxide, And Ratios Of Molybdenum (Vi) Oxide And Tungsten (Vi) Oxide At Atomspheric Pressure, Sean M. Pelfrey May 2015

Oxidation Of Dibenzothiophene To Dibenzothiophene-Sulfone Using Molybdenum (Vi) Oxide, Tungsten (Vi) Oxide, And Ratios Of Molybdenum (Vi) Oxide And Tungsten (Vi) Oxide At Atomspheric Pressure, Sean M. Pelfrey

Theses and Dissertations - UTB/UTPA

This is a study of the catalytic oxidation of dibenzothiophene to dibenzothiophene sulfone using molybdenum (VI) oxide, tungsten (VI) oxide, and mixtures of molybdenum (VI) oxide and tungsten (VI) oxide at atmospheric pressure. The oxidative desulfurization reaction is studied with respect to the kinetics and thermodynamics of the process. Five catalysts were synthesized using a precipitation reaction. The five catalysts were 100% MoO3, 75/25% MoO3/WO3, 50/50% MoO3/WO3, 25/75% MoO3/WO3, and 100% WO3. Each catalyst was calcinated at three different temperatures 250oC, 500oC, 750oC and characterized using X-Ray Diffraction. Reactions of DBT-catalyst were held, under reflux, at temperatures from 140 oC …


Removal Of Cobalt And Nickel From Water Using Mno2 And Mn3o4 Nanomaterials, Maria Dolores Pacheco May 2015

Removal Of Cobalt And Nickel From Water Using Mno2 And Mn3o4 Nanomaterials, Maria Dolores Pacheco

Theses and Dissertations - UTB/UTPA

Nanomaterials MnO2 and Mn3O4 were synthesized using a titration/precipitation technique and characterized with powder XRD. A pH assay determined the optimum binding for cobalt and nickel occurred at pH 5 for both nanomaterials. A time dependency study determined that cobalt and nickel required more time with MnO2 for maximum adsorption than Mn3O4. The binding capacity study showed cobalt and nickel have good binding capacity with both nanomaterials. Interfering ion assay in the presence of Na+ , Ca2+ and Mg2+ showed minimal difference in the adsorption of cobalt and nickel to MnO2 or Mn3O4. Cobalt and nickel showed a reduction in …


Enzymatic Synthesis Of Magnetic Nanoparticles, Arati G. Kolhatkar, Chamath Dannongoda, Katerina Kourentzi, Andrew C. Jamison, Ivan Nekrashevich, Archana Kar, Eliedonna Cacao, Ulrich Strych, Irene Rusakova, Karen S. Martirosyan, Dmitri Litvinov, T. Randall Lee, Richard C. Willson Apr 2015

Enzymatic Synthesis Of Magnetic Nanoparticles, Arati G. Kolhatkar, Chamath Dannongoda, Katerina Kourentzi, Andrew C. Jamison, Ivan Nekrashevich, Archana Kar, Eliedonna Cacao, Ulrich Strych, Irene Rusakova, Karen S. Martirosyan, Dmitri Litvinov, T. Randall Lee, Richard C. Willson

Physics and Astronomy Faculty Publications and Presentations

We report the first in vitro enzymatic synthesis of paramagnetic and antiferromagnetic nanoparticles toward magnetic ELISA reporting. With our procedure, alkaline phosphatase catalyzes the dephosphorylation of L-ascorbic-2-phosphate, which then serves as a reducing agent for salts of iron, gadolinium, and holmium, forming magnetic precipitates of Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5. The nanoparticles were found to be paramagnetic at 300 K and antiferromagnetic under 25 K. Although weakly magnetic at 300 K, the room-temperature magnetization of the nanoparticles found here is considerably greater than that of analogous chemically-synthesized LnxFeyOz (Ln = Gd, Ho) samples reported previously. At 5 K, the nanoparticles showed a …


Directed Search For Gravitational Waves From Scorpius X-1 With Initial Ligo Data, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. S. Areeda, N. Arnaud Mar 2015

Directed Search For Gravitational Waves From Scorpius X-1 With Initial Ligo Data, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. S. Areeda, N. Arnaud

Physics and Astronomy Faculty Publications and Presentations

We present results of a search for continuously emitted gravitational radiation, directed at the brightest low-mass x-ray binary, Scorpius X-1. Our semicoherent analysis covers 10 days of LIGO S5 data ranging from 50-550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and …


Changes In Spatial Patterns Of Caragana Stenophylla Along A Climatic Drought Gradient On The Inner Mongolian Plateau, Li-Na Xie, Hong-Yu Guo, Christopher A. Gabler, Qing-Fang Li, Cheng-Cang Ma Mar 2015

Changes In Spatial Patterns Of Caragana Stenophylla Along A Climatic Drought Gradient On The Inner Mongolian Plateau, Li-Na Xie, Hong-Yu Guo, Christopher A. Gabler, Qing-Fang Li, Cheng-Cang Ma

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Few studies have investigated the influence of water availability on plant population spatial patterns. We studied changes in the spatial patterns of Caragana stenophylla along a climatic drought gradient within the Inner Mongolian Plateau, China. We examined spatial patterns, seed density, “nurse effects” of shrubs on seedlings, transpiration rates and water use efficiency (WUE) of C. stenophylla across semi-arid, arid, and intensively arid zones. Our results showed that patches of C. stenophylla populations shifted from a random to a clumped spatial pattern towards drier environments. Seed density and seedling survival rate of C. stenophylla decreased from the semi-arid zone to …


Microbial Iron Mats At The Mid-Atlantic Ridge And Evidence That Zetaproteobacteria May Be Restricted To Iron-Oxidizing Marine Systems, Jarrod J. Scott, John A. Breier, George W. Luther Iii, David Emerson Mar 2015

Microbial Iron Mats At The Mid-Atlantic Ridge And Evidence That Zetaproteobacteria May Be Restricted To Iron-Oxidizing Marine Systems, Jarrod J. Scott, John A. Breier, George W. Luther Iii, David Emerson

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Chemolithoautotrophic iron-oxidizing bacteria play an essential role in the global iron cycle. Thus far, the majority of marine iron-oxidizing bacteria have been identified as Zetaproteobacteria, a novel class within the phylum Proteobacteria. Marine iron-oxidizing microbial communities have been found associated with volcanically active seamounts, crustal spreading centers, and coastal waters. However, little is known about the presence and diversity of iron-oxidizing communities at hydrothermal systems along the slow crustal spreading center of the Mid-Atlantic Ridge. From October to November 2012, samples were collected from rust-colored mats at three well-known hydrothermal vent systems on the Mid-Atlantic Ridge (Rainbow, Trans-Atlantic Geotraverse, and …


Subclinical Atherosclerosis And Obesity Phenotypes Among Mexican Americans, Susan T. Laing, Beverly Smulevitz, Kristina Vatcheva, Mohammad H. Rahbar, Belinda M. Reininger, David D. Mcpherson, Joseph B. Mccormick, Susan P. Fisher-Hoch Mar 2015

Subclinical Atherosclerosis And Obesity Phenotypes Among Mexican Americans, Susan T. Laing, Beverly Smulevitz, Kristina Vatcheva, Mohammad H. Rahbar, Belinda M. Reininger, David D. Mcpherson, Joseph B. Mccormick, Susan P. Fisher-Hoch

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Background

Data on the influence of obesity on atherosclerosis in Hispanics are inconsistent, possibly related to varying cardiometabolic risk among obese individuals. We aimed to determine the association of obesity and cardiometabolic risk with subclinical atherosclerosis in Mexican‐Americans.

Methods and Results

Participants (n=503) were drawn from the Cameron County Hispanic Cohort. Metabolic health was defined as <2 of the following: blood pressure ≥130/85; triglyceride ≥150 mg/dL; high‐density lipoprotein cholesterol <40 mg/dL (men) or <50 mg/dL (women); fasting glucose ≥100 mg/dL; homeostasis model assessment of insulin resistance value >5.13; or high‐sensitivity C‐reactive protein >3 mg/L. Carotid intima media thickness (cIMT) was measured. A high proportion of participants (77.8%) were metabolically unhealthy; they were more likely to be male, older, with fewer years of education, and less likely to meet daily recommendations regarding …


Timing Of Five Millisecond Pulsars Discovered In The Palfa Survey, P. Scholz, V. M. Kaspi, A. G. Lyne, B. W. Stappers, S. Bogdanov, J. M. Cordes, F. Crawford, R. D. Ferdman, P. C.C. Freire, J. W.T. Hessels, D. R. Lorimer, I. H. Stairs, B. Allen, A. Brazier, F. Camilo, R. F. Cardoso, S. Chatterjee, J. S. Deneva, F. A. Jenet, C. Karako-Argaman, B. Knispel, P. Lazarus, K. J. Lee, J. Van Leeuwen, R. Lynch, E. C. Madsen, M. A. Mclaughlin, S. M. Ransom, X. Siemens, L. G. Spitler Feb 2015

Timing Of Five Millisecond Pulsars Discovered In The Palfa Survey, P. Scholz, V. M. Kaspi, A. G. Lyne, B. W. Stappers, S. Bogdanov, J. M. Cordes, F. Crawford, R. D. Ferdman, P. C.C. Freire, J. W.T. Hessels, D. R. Lorimer, I. H. Stairs, B. Allen, A. Brazier, F. Camilo, R. F. Cardoso, S. Chatterjee, J. S. Deneva, F. A. Jenet, C. Karako-Argaman, B. Knispel, P. Lazarus, K. J. Lee, J. Van Leeuwen, R. Lynch, E. C. Madsen, M. A. Mclaughlin, S. M. Ransom, X. Siemens, L. G. Spitler

Physics and Astronomy Faculty Publications and Presentations

We present the discovery of five millisecond pulsars (MSPs) from the PALFA Galactic plane survey using Arecibo. Four of these (PSRs J0557+1551, J1850+0244, J1902+0300, and J1943+2210) are binary pulsars whose companions are likely white dwarfs, and one (PSR J1905+0453) is isolated. Phase-coherent timing solutions, ranging from 1 to 3 yr in length, and based on observations from the Jodrell Bank and Arecibo telescopes, provide precise determinations of spin, orbital, and astrometric parameters. All five pulsars have large dispersion measures (>100 pc cm-3, within the top 20% of all known Galactic field MSPs) and are faint (1.4 GHz flux density …


Narrow-Band Search Of Continuous Gravitational-Wave Signals From Crab And Vela Pulsars In Virgo Vsr4 Data, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. S. Areeda, Mario C. Diaz, Malik Rakhmanov, Joseph D. Romano, Soma Mukherjee, Volker Quetschke, Teviet Creighton, Robert Stone Jan 2015

Narrow-Band Search Of Continuous Gravitational-Wave Signals From Crab And Vela Pulsars In Virgo Vsr4 Data, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. S. Areeda, Mario C. Diaz, Malik Rakhmanov, Joseph D. Romano, Soma Mukherjee, Volker Quetschke, Teviet Creighton, Robert Stone

Physics and Astronomy Faculty Publications and Presentations

In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown …


Long-Range Pcr Amplification Of Dna By Dna Polymerase Iii Holoenzyme From Thermus Thermophilus, Wendy Ribble, Shawn D. Kane, James M. Bullard Jan 2015

Long-Range Pcr Amplification Of Dna By Dna Polymerase Iii Holoenzyme From Thermus Thermophilus, Wendy Ribble, Shawn D. Kane, James M. Bullard

Chemistry Faculty Publications and Presentations

DNA replication in bacteria is accomplished by a multicomponent replicase, the DNA polymerase III holoenzyme (pol III HE). The three essential components of the pol III HE are the α polymerase, the β sliding clamp processivity factor, and the DnaX clamp-loader complex. We report here the assembly of the functional holoenzyme from Thermus thermophilus (Tth), an extreme thermophile. The minimal holoenzyme capable of DNA synthesis consists of α, β and DnaX ( and γ), and components of the clamp-loader complex. The proteins were each cloned and expressed in a native form. Each component of the system was purified extensively. The …


Multiple-Time Step Ab Initio Molecular Dynamics Based On Two-Electron Integral Screening, Shervin Fatehi, Ryan P. Steele Jan 2015

Multiple-Time Step Ab Initio Molecular Dynamics Based On Two-Electron Integral Screening, Shervin Fatehi, Ryan P. Steele

Chemistry Faculty Publications and Presentations

A multiple-timestep ab initio molecular dynamics scheme based on varying the two-electron integral screening method used in Hartree–Fock or density functional theory calculations is presented. Although screening is motivated by numerical considerations, it is also related to separations in the length- and timescales characterizing forces in a molecular system: Loose thresholds are sufficient to describe fast motions over short distances, while tight thresholds may be employed for larger length scales and longer times, leading to a practical acceleration of ab initio molecular dynamics simulations. Standard screening approaches can lead, however, to significant discontinuities in (and inconsistencies between) the energy and …


Searching For Stochastic Gravitational Waves Using Data From The Two Colocated Ligo Hanford Detectors, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, F. Acernese, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, C. Affeldt, M. Agathos, N. Aggarwal, O. D. Aguiar, P. Ajith, B. Allen, A. Allocca, E. Amador Ceron, D. Amariutei, R. A. Anderson, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. Areeda, S. Ast, S. M. Aston Jan 2015

Searching For Stochastic Gravitational Waves Using Data From The Two Colocated Ligo Hanford Detectors, J. Aasi, J. Abadie, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, F. Acernese, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, C. Affeldt, M. Agathos, N. Aggarwal, O. D. Aguiar, P. Ajith, B. Allen, A. Allocca, E. Amador Ceron, D. Amariutei, R. A. Anderson, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. Areeda, S. Ast, S. M. Aston

Physics and Astronomy Faculty Publications and Presentations

Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a colocated detector pair is more sensitive to a gravitational-wave background than a noncolocated detector pair. However, colocated detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the …


Consumer Acceptance Of Personal Cloud: Integrating Trust And Risk With The Technology Acceptance Model, Murad Moqbel, Valerie L. Bartelt Jan 2015

Consumer Acceptance Of Personal Cloud: Integrating Trust And Risk With The Technology Acceptance Model, Murad Moqbel, Valerie L. Bartelt

Information Systems Faculty Publications and Presentations

This paper conducts a conceptual replication of Pavlou (2003) which studied factors that impacted consumer’s behavioral intentions to make online transactions by integrating trust and perceived risk with the technology acceptance model (TAM). We test the generalizability of the model by replicating the study a decade later using a different online setting—personal cloud computing. Our results that are based on 240 observations, confirm the original study’s research model except perceived ease of use lost its direct predictive power to trust, perceived risk and perceived usefulness. Trust continues to be an important factor in perceived ease of use and perceived usefulness …


Octocoral Mitochondrial Genomes Provide Insights Into The Phylogenetic History Of Gene Order Rearrangements, Order Reversals, And Cnidarian Phylogenetics, Diego F. Figueroa, Amy R. Baco Jan 2015

Octocoral Mitochondrial Genomes Provide Insights Into The Phylogenetic History Of Gene Order Rearrangements, Order Reversals, And Cnidarian Phylogenetics, Diego F. Figueroa, Amy R. Baco

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We use full mitochondrial genomes to test the robustness of the phylogeny of the Octocorallia, to determine the evolutionary pathway for the five known mitochondrial gene rearrangements in octocorals, and to test the suitability of using mitochondrial genomes for higher taxonomic-level phylogenetic reconstructions. Our phylogeny supports three major divisions within the Octocorallia and show that Paragorgiidae is paraphyletic, with Sibogagorgia forming a sister branch to the Coralliidae. Furthermore, Sibogagorgia cauliflora has what is presumed to be the ancestral gene order in octocorals, but the presence of a pair of inverted repeat sequences suggest that this gene order was not conserved …


Imaging, Spectroscopy, Mechanical, Alignment And Biocompatibility Studies Of Electrospun Medical Grade Polyurethane (Carbothane™ 3575a) Nanofibers And Composite Nanofibers Containing Multiwalled Carbon Nanotubes, Faheem A. Sheikh, Javier Macossay-Torres, Travis Cantu, Xujun Zhang, M. Shamshi Hassan, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, Hern Kim, Gary L. Bowlin Jan 2015

Imaging, Spectroscopy, Mechanical, Alignment And Biocompatibility Studies Of Electrospun Medical Grade Polyurethane (Carbothane™ 3575a) Nanofibers And Composite Nanofibers Containing Multiwalled Carbon Nanotubes, Faheem A. Sheikh, Javier Macossay-Torres, Travis Cantu, Xujun Zhang, M. Shamshi Hassan, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, Hern Kim, Gary L. Bowlin

Chemistry Faculty Publications and Presentations

In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior …


An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy Jan 2015

An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy

Chemistry Faculty Publications and Presentations

The phenomenon of seed dormancy is widespread in plants and serves to prevent all or most of a given population from germinating at the “wrong” time, e.g., during an unusually mild fall in an area subject to typically harsh winters. Seed dormancy is an effective survival strategy in many plant populations, but may greatly complicate efforts to establish large cohorts of seedlings (groups of similar age or developmental stage) needed for re-search and other purposes. In an effort to break seed dormancy in common sunflower, Helianthus annuus L. (Asteraceae), we conducted experiments designed to compare germination times and overall germination …


Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt Jan 2015

Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt

Physics and Astronomy Faculty Publications and Presentations

Supervised image classifications developed from 23 x 23 cm aerial color-infrared aerial photographs (1:5,000 scale) were used to evaluate temporal changes in vegetative cover occurring within three 150 x 300-m research sites on South Padre Island, Texas. Use of high-resolution digitized imagery (ground pixel resolution of ca. 0.1 m) and survey-grade GPS for positional measurements of ground control points (20-25 1.0m2 targets within each research site) resulted in consistently high levels of geometric accuracy, with root mean square errors (RMSEs) ranging between 0.397 – 2.867. Similarly, use of relatively simple information categories (dry and wet sand, live and dead vegetative …


Understanding The Gravitational-Wave Hellings And Downs Curve For Pulsar Timing Arrays In Terms Of Sound And Electromagnetic Waves, Fredrick A. Jenet, Joseph D. Romano Jan 2015

Understanding The Gravitational-Wave Hellings And Downs Curve For Pulsar Timing Arrays In Terms Of Sound And Electromagnetic Waves, Fredrick A. Jenet, Joseph D. Romano

Physics and Astronomy Faculty Publications and Presentations

Searches for stochastic gravitational-wave backgrounds using pulsar timing arrays look for correlations in the timing residuals induced by the background across the pulsars in the array. The correlation signature of an isotropic, unpolarized gravitational-wave background predicted by general relativity follows the so-called Hellings and Downs curve, which is a relatively simple function of the angle between a pair of Earth-pulsar baselines. In this paper, we give a pedagogical discussion of the Hellings and Downs curve for pulsar timing arrays, considering simpler analogous scenarios involving sound and electromagnetic waves. We calculate Hellings-and-Downs-type functions for these two scenarios and develop a framework …


Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov Jan 2015

Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov

Chemistry Faculty Publications and Presentations

We report herein a palladium-catalyzed C-H arylation of quinoline N-oxides that proceeds with high selectivity in favor of the C8-isomer. This site-selectivity is unusual for palladium, since all of the hitherto described methods of palladium-catalyzed C-H functionalization of quinoline N-oxides are highly C2-selective. The reaction exhibits a broad synthetic scope with respect to quinoline N-oxides and iodoarenes and can be significantly accelerated to sub-hour reaction times under microwave irradiation. The C8-arylation method can be carried out on gram scale and has excellent functional group tolerance. Mechanistic and Density Functional Theory (DFT) computational studies provide evidence for the …


Curcumin: A Folklore Remedy From Kitchen On The Way To Clinic As Cancer Drug, Debasish Bandyopadhyay Jan 2015

Curcumin: A Folklore Remedy From Kitchen On The Way To Clinic As Cancer Drug, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Numerous compounds are widely distributed in nature and many of these possess medicinal/biological/pharmacological activity. Curcumin, a polyphenol derived from the rhizomes (underground stems) of Curcuma longa Linn (a member of the ginger family, commonly known as turmeric) is a culinary spice and therapeutic used in India for thousands of years to induce color and flavor in food as well as to treat a wide array of diseases. The origin of turmeric as spice and folklore medicine is so old that it is lost in legend. Curcumin has many beneficial pharmacological effects which includes, but are not limited with, antimicrobial, anti-inflammatory, …


Statistical Modeling Of Microrna Expression With Human Cancers, Ke-Sheng Wang, Yue Pan, Chun Xu Jan 2015

Statistical Modeling Of Microrna Expression With Human Cancers, Ke-Sheng Wang, Yue Pan, Chun Xu

Health & Biomedical Sciences Faculty Publications and Presentations

MicroRNAs (miRNAs) are small non-coding RNAs (containing about 22 nucleotides) that regulate gene expression. MiRNAs are involved in many different biological processes such as cell proliferation, differentiation, apoptosis, fat metabolism, and human cancer genes; while miRNAs may function as candidates for diagnostic and prognostic biomarkers and predictors of drug response. This paper emphasizes the statistical methods in the analysis of the associations of miRNA gene expression with human cancers and related clinical phenotypes: 1) simple statistical methods include chi-square test, correlation analysis, t-test and one-way ANOVA; 2) regression models include linear and logistic regression; 3) survival analysis approaches such as …


Public Exposure To U.S. Commercial Nuclear Power Plants Induced Disasters, Dean Kyne Jan 2015

Public Exposure To U.S. Commercial Nuclear Power Plants Induced Disasters, Dean Kyne

Sociology Faculty Publications and Presentations

This study explores the potential risks associated with the 65 U.S.-based commercial nuclear power plants and the distribution of those risks among the populations of both their respective host communities and of the communities located in outlying areas. First, it starts by examining the racial/ethnic composition of the host community populations, as well as the disparities in socioeconomic status that exist, if any, between the host communities and communities located in outlying areas. Second, it utilizes two independent-sample T tests to identify any differences in the sociodemographic compositions of the two areas. Third, it explores regional demographic trends by looking …


Empirical Modelling Of Solid-Blocking Effect In A Blazka Respirometer For Gag, A Large Demersal Reef Fish, Richard J. Kline, Daryl C. Parkyn, Debra J. Murie Jan 2015

Empirical Modelling Of Solid-Blocking Effect In A Blazka Respirometer For Gag, A Large Demersal Reef Fish, Richard J. Kline, Daryl C. Parkyn, Debra J. Murie

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The effect of solid-body blocking in a large (257 l) Blazka-style respirometer was examined in gag Mycteroperca microlepis. Gag ranging from 376-690 mm total length were tested at velocities from 10 to 91 cm s-1 . The solid blocking effect (SBE) due to fish size, swimming speed, and water temperature was investigated by direct measurement of flow velocity at the area of the fish’s maximum girth as compared to measurements at the rear (center) of the swimming chamber. Three models were compared as corrections for the SBE: the standard Bell and Terhune (BT), a novel modification of the Bell and …


Universal Computation With Arbitrary Polyomino Tiles In Non-Cooperative Self-Assembly, Sándor P. Fekete, Jacob Hendricks, Matthew J. Patitz, Trent A. Rogers Jan 2015

Universal Computation With Arbitrary Polyomino Tiles In Non-Cooperative Self-Assembly, Sándor P. Fekete, Jacob Hendricks, Matthew J. Patitz, Trent A. Rogers

Computer Science Faculty Publications and Presentations

In this paper we explore the power of geometry to overcome the limitations of non-cooperative self-assembly. We define a generalization of the abstract Tile Assembly Model (aTAM), such that a tile system consists of a collection of polyomino tiles, the Polyomino Tile Assembly Model (polyTAM), and investigate the computational powers of polyTAM systems at temperature 1, where attachment among tiles occurs without glue cooperation (i.e., without the enforcement that more than one tile already existing in an assembly must contribute to the binding of a new tile). Systems composed of the unit-square tiles of the aTAM at temperature 1 …


Employees’ Social Networking Site Use Impact On Job Performance: Evidence From Pakistan, Murad Moqbel, Fizza Aftab Jan 2015

Employees’ Social Networking Site Use Impact On Job Performance: Evidence From Pakistan, Murad Moqbel, Fizza Aftab

Information Systems Faculty Publications and Presentations

This paper reinvestigates the impact of social networking site use by employees on job performance by conducting a methodological replication of Moqbel, Nevo, and Kock (2013) using samples (N=139) from Pakistan. In both studies, social networking site use has significant effects on organizational commitment and job satisfaction, and job satisfaction also has a significant impact on job performance and organizational commitment. In comparison with the U.S., we find that social networking site use in Pakistan has no significant impact on job performance through the mediating effect of job satisfaction, yet has a significant effect on organizational commitment and job satisfaction. …


Prospects For Detection Of Extragalactic Stellar Black Hole Binaries In The Nearby Universe, Matthew Benacquista, Jesus Hinojosa, Alberto Mata, Krzysztof Belczynski Jan 2015

Prospects For Detection Of Extragalactic Stellar Black Hole Binaries In The Nearby Universe, Matthew Benacquista, Jesus Hinojosa, Alberto Mata, Krzysztof Belczynski

Physics and Astronomy Faculty Publications and Presentations

Stellar mass black hole binaries have individual masses between 10-80 solar masses. These systems may emit gravitational waves at frequencies detectable at Megaparsec distances by space-based gravitational wave observatories. In a previous study, we determined the selection effects of observing these systems with detectors similar to the Laser Interferometer Space Antenna by using a generated population of binary black holes that covered a reasonable parameter space and calculating their signal-to-noise ratio. We further our study by populating the galaxies in our nearby (less than 30 Mpc) universe with binary black hole systems drawn from a distribution found in the Synthetic …