Physical Sciences and Mathematics Commons^™

Detecting Submarine Groundwater Discharge With Synoptic Surveys Of Sediment Resistivity, Radium, And Salinity, John A. Breier, Crystaline F. Breier, Henrietta Edmonds

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

A synoptic geophysical and geochemical survey was used to investigate the occurrence and spatial distribution of submarine discharges of water to upper Nueces Bay, Texas. The 17 km survey incorporated continuous resistivity profiling; measurements of surface water salinity, temperature, and dissolved oxygen; and point measurements of dissolved Ra isotopes. The survey revealed areas of interleaving, vertical fingers of high and low conductivity extending up through 7 m of bay bottom sediments into the surface water, located within 100 m of surface salinity and dissolved Ra maxima along with peaks in water temperature and lows in dissolved oxygen. These results indicate …

Discovery And Characterization Of The Cryptic Psi Subunit Of The Pseudomonad Dna Replicase, Thale C. Jarvis, Amber A. Beaudry, James M. Bullard, Urs Ochsner, H. Garry Dallmann, Charles S. Mchenry

Chemistry Faculty Publications and Presentations

We previously reconstituted a minimal DNA replicase from Pseudomonas aeruginosa consisting of α and ϵ (polymerase and editing nuclease), β (processivity factor), and the essential τ, δ, and δ′ components of the clamp loader complex (Jarvis, T., Beaudry, A., Bullard, J., Janjic, N., and McHenry, C. (2005) J. Biol. Chem. 280, 7890-7900). In Escherichia coli DNA polymerase III holoenzyme, χ and Ψ are tightly associated clamp loader accessory subunits. The addition of E. coli χΨ to the minimal P. aeruginosa replicase stimulated its activity, suggesting the existence of χ and Ψ counterparts in P. aeruginosa. The P. aeruginosa χ …

An Improvement And A Generalization Of Zippel's Sparse Multivariate Polynomial Interpolation Algorithm, Michael D. Brazier

Theses and Dissertations - UTB/UTPA

The algorithm most often used for the problem of interpolating sparse multivariate polynomials from their values is Zippel's probabilistic algorithm (1988). The algorithm evaluates the function to be interpolated at a significant number of points, and for many problems of interest processing evaluations dominates the running time. This thesis presents an improvement of Zippel's algorithm, which decreases the number of evaluations needed for an interpolation by using transposed Vandermonde systems for the univariate interpolation step of Zippel's algorithm. The technique also allows a more general form of the algorithm: it becomes possible to interpolate more than one variable within a …

Improving The Performance Of Nested Loop Algorithm Using Separators, Nachiappan N. Nachiappan

Theses and Dissertations - UTB/UTPA

This thesis studies the properties of distance-based outliers and a better detection method for large multi-dimensional datasets. Outlier detection is an important task to find out the objects that deviate in a high ratio from the rest of the objects. The proposed algorithm breaks the data set into divisions and sets the area of access for each division, thus reducing the unnecessary access for a major set of elements. This algorithm reduces the run time of the existing algorithm by using separators. Datasets of varying sizes have been tested to analyze the empirical values of these procedures. Effective data structures …

Numerical Integration Of The Teukolsky Equation In The Time Domain, Enrique Pazos-Avalos, Carlos O. Lousto

Physics and Astronomy Faculty Publications and Presentations

We present a fourth-order convergent, (2+1)-dimensional, numerical formalism to solve the Teukolsky equation in the time domain. Our approach is first to rewrite the Teukolsky equation as a system of first-order differential equations. In this way we get a system that has the form of an advection equation. This is then used in combination with a series expansion of the solution in powers of time. To obtain a fourth-order scheme we kept terms up to fourth derivative in time and use the advectionlike system of differential equations to substitute the temporal derivatives by spatial derivatives. This scheme is applied to …

Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri

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

We tested the potential of estimating per-pixel gross primary production (GPP) directly from the MODIS enhanced vegetation index (EVI) and respiration directly from MODIS surface temperature (MOD11). Carbon flux data were obtained from 10 eddy covariance tower sites representing a wide range of North American vegetations. The correlation between across-site tower GPP and EVI was comparable (r = 0.77) to that between tower GPP and MOD17-GPP (r = 0.73), suggesting that EVI could be used to provide reasonably accurate direct estimates of GPP on a truly per-pixel basis. There was also a strong relationship (r2 = 0.67) between respiration and …

A Bacillus Thuringiensis Isolation Method Utilizing A Novel Stain, Low Selection And High Throughput Produced Atypical Results, Joanne Rampersad-Ammons, David R. Ammons

Chemistry Faculty Publications and Presentations

Background

Bacillus thuringiensis is a bacterium known for producing protein crystals with insecticidal properties. These toxins are widely sought after for controlling agricultural pests due to both their specificity and their applicability in transgenic plants. There is great interest in isolating strains with improved or novel toxin characteristics, however isolating B. thuringiensis from the environment is time consuming and yields relatively few isolates of interest. New approaches to B. thuringiensis isolation have been, and continue to be sought. In this report, candidate B. thuringiensis isolates were recovered from environmental samples using a combination of a novel stain, high throughput and …

Α-Enhanced Integrated Lick/Ids Spectral Indices And Milky Way And M31 Globular Clusters And Early-Type Galaxies, Hyun Chul Lee, Guy Worthey

Physics and Astronomy Faculty Publications and Presentations

All 25 Lick/IDS spectral indices have been computed for the integrated light of simple stellar populations over broad ranges of age and metallicity and with effects from horizontal-branch stars fully implemented. Our models employ α-enhanced isochrones at the sub-solar metallicity regime, but solar-scaled ones at solar and super-solar metallicity. We have also employed the updated response functions of Houdashelt et al. at the solar and super-solar metallicity regime, so that we could assess the light-element enhancement phenomena seen from metal-rich early-type galaxies. For Balmer indices a significant response was noted for Hγ and Hδ when α-elements are enhanced, but Hβ …

A Nested-Pcr With An Internal Amplification Control For The Detection And Differentiation Of Bartonella Henselae And B. Clarridgeiae: An Examination Of Cats In Trinidad, Joanne Rampersad, John D. Watkins, Michael S. Samlal, Raymond Deonanan, Shalini Ramsubeik, David Ammons

Chemistry Faculty Publications and Presentations

Background

Bartonella species are bacterial blood parasites of animals capable of causing disease in both animals and man. Cat-Scratch Disease (CSD) in humans is caused mainly by Bartonella henselae and is acquired from the cat, which serves as a reservoir for the bacteria. A second species, B. clarridgeiae is also implicated in the disease. Diagnosis of Bartonellosis by culture requires a week or more of incubation on enriched media containing blood, and recovery is often complicated by faster growing contaminating bacteria and fungi. PCR has been explored as an alternative to culture for both the detection and species identification of …

Entropy-Based 2d Image Dissimilarity Measure, Meng-Hung Wu

Theses and Dissertations - UTB/UTPA

Traditional histogram or statistics based 2D image similarity/dissimilarity metrics fail to handle conjugate pair of black and white images, due to the lack of spatial information in the measurement. Recently proposed Compression-based Dissimilarity Measure (CDM) [1] based on the concept of Kolmogorov complexity has provided a different paradise for similarity measurement. However, without a clear definition how to “concatenate” two 2D images, CDM has difficulties to directly apply with 2D images. In this thesis, an entropy -based 2D image dissimilarity measure is proposed within the same Kolmogorov complexity paradise. The spatial relationship between images is embedded in our metric, and …

Naboh System: Gathering Intelligence From Traffic Patterns, Angelica M. Delgado

Theses and Dissertations - UTB/UTPA

Network traffic anomalies are important indicators of problematic traffic over a network. Network activity has patterns associated with it depending on the applications running on the local hosts connected to the network. There are traffic parameters into which network traffic of a local host can be divided: bandwidth usage, number of remote hosts that a local host is connecting to and vice versa, and number of ports used by the local host. This thesis develops a system for detecting and profiling network anomalies by analyzing traffic parameters using intelligent computational techniques. The developed system gathers intelligence by examining only the …

Pulsar Timing And The Detection Of Black Hole Binary Systems In Globular Clusters, Fredrick A. Jenet, Teviet Creighton, Andrea Lommen

Physics and Astronomy Faculty Publications and Presentations

The possible existence of intermediate-mass binary black holes (IMBBHs) in globular clusters (GCs) offers us a unique geometry in which to detect spacetime oscillations. For certain pulsar-IMBBH configurations possible within a GC, the usual far-field plane wave approximation for the IMBBH metric perturbation severely underestimates the induced pulse time-of-arrival (TOA) fluctuations. In this Letter, the expected TOA fluctuations induced by an IMBBH lying close to the line of sight between a pulsar and the Earth are calculated for the first time. For an IMBBH consisting of 10 and 103 M⊙ components, a 10 yr orbital period, and located 0.1 lt-yr …

Detecting The Stochastic Gravitational Wave Background Using Pulsar Timing, Fredrick A. Jenet, George B. Hobbs, K. J. Lee, Richard N. Manchester

Physics and Astronomy Faculty Publications and Presentations

The direct detection of gravitational waves is a major goal of current astrophysics. We provide details of a new method for detecting a stochastic background of gravitational waves using pulsar timing data. Our results show that regular timing observations of 40 pulsars each with a timing accuracy of 100 ns will be able to make a direct detection of the predicted stochastic background from coalescing black holes within 5 years. With an improved prewhitening algorithm, or if the background is at the upper end of the predicted range, a significant detection should be possible with only 20 pulsars. © 2005. …

Empirical Performance Analysis Of Two Algorithms For Mining Intentional Knowledge Of Distance-Based Outliers, Enbamoorthy Prasanthi

Theses and Dissertations - UTB/UTPA

This thesis studies the empirical analysis of two algorithms, Uplattice and Jumplattice for mining intentional knowledge of distance-based outliers [19]. These algorithms detect strongest and weak outliers among them. Finding outliers is an important task required in major applications such as credit-card fraud detection, and the NHL statistical studies. Datasets of varying sizes have been tested to analyze the empirical values of these two algorithms. Effective data structures have been used to gain efficiency in memory-performance. The two algorithms provide intentional knowledge of the detected outliers which determines as to why an identified outlier is exceptional. This knowledge helps the …

Compensation For Automatic White Balance Correction With Histogram Equalization, David D. Kirtley

Theses and Dissertations - UTB/UTPA

Histogram equalization rather than hard scaling can be used as an effective technique to counter automatic white balance correction in video processing to facilitate motion detection in video sequences. Benefits of this method are less user interaction needed by not needing to preview the image to select a scaling area and reduction of the non-focused changes in the video caused by using a scaling area. Reduced interaction lends itself to data mining of video.

Reconstitution Of A Minimal Dna Replicase From Pseudomonas Aeruginosa And Stimulation By Non-Cognate Auxiliary Factors, Thale C. Jarvis, Amber A. Beaudry, James M. Bullard, Nebojsa Janjic, Charles S. Mchenry

Chemistry Faculty Publications and Presentations

DNA polymerase III holoenzyme is responsible for chromosomal replication in bacteria. The components and functions of Escherichia coli DNA polymerase III holoenzyme have been studied extensively. Here, we report the reconstitution of replicase activity by essential components of DNA polymerase holoenzyme from the pathogen Pseudomonas aeruginosa. We have expressed and purified the processivity factor (β), single-stranded DNA-binding protein, a complex containing the polymerase (α) and exonuclease (ϵ) subunits, and the essential components of the DnaX complex (τ₃δδ′). Efficient primer elongation requires the presence of αϵ, β, and τ₃δδ′. Pseudomonas aeruginosa αϵ can substitute completely for …

Search For Gravitational Waves Associated With The Gamma Ray Burst Grb030329 Using The Ligo Detectors, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We have performed a search for bursts of gravitational waves associated with the very bright gamma ray burst GRB030329, using the two detectors at the LIGO Hanford Observatory. Our search covered the most sensitive frequency range of the LIGO detectors (approximately 80–−2048   Hz), and we specifically targeted signals shorter than ≃150  ms. Our search algorithm looks for excess correlated power between the two interferometers and thus makes minimal assumptions about the gravitational waveform. We observed no candidates with gravitational-wave signal strength larger than a predetermined threshold. We report frequency-dependent upper limits on the strength of the gravitational waves associated with …

Phase Effects In The Diffraction Of Light: Beyond The Grating Equation, Stacy Wise, V. Quetschke, A. J. Deshpande, G. Mueller, D. H. Reitze, D. B. Tanner, B. F. Whiting, Y. Chen

Physics and Astronomy Faculty Publications and Presentations

Diffraction gratings affect the absolute phase of light in a way that is not obvious from the usual derivation of optical paths using the grating equation. For example, consider light which encounters first one and then the second of two parallel gratings. If one grating is moved parallel to its surface, the phase of the light diffracted from the grating pair is shifted by 2π each time the grating is moved by one grating constant, even though the geometric path length is not altered by the motion. This additional phase shift must be included when incorporating diffraction gratings in interferometers.

First All-Sky Upper Limits From Ligo On The Strength Of Periodic Gravitational Waves Using The Hough Transform, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We perform a wide parameter-space search for continuous gravitational waves over the whole sky and over a large range of values of the frequency and the first spin-down parameter. Our search method is based on the Hough transform, which is a semicoherent, computationally efficient, and robust pattern recognition technique. We apply this technique to data from the second science run of the LIGO detectors and our final results are all-sky upper limits on the strength of gravitational waves emitted by unknown isolated spinning neutron stars on a set of narrow frequency bands in the range 200–400   Hz. The best upper …

Upper Limits On A Stochastic Background Of Gravitational Waves, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of Ω0

Response Of Test Masses To Gravitational Waves In The Local Lorentz Gauge, Malik Rakhmanov

Physics and Astronomy Faculty Publications and Presentations

The local Lorentz gauge represents a natural coordinate frame for an observer to analyze the effect of gravitational waves on detectors, and has been widely used to describe the response of resonant bars. Its application to laser interferometers has thus far been restricted to the long-wavelength regime, in which the separation between the test masses is much less than the wavelength of the gravitational waves. In this paper we show that the local Lorentz gauge can be used for calculations of geodesic deviations of the masses even when their separation is comparable to or greater than the wavelength of the …

Limits On Gravitational-Wave Emission From Selected Pulsars Using Ligo Data, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10−24. These strain limits translate into limits on the equatorial ellipticities of the pulsars, …

Search For Gravitational Waves From Galactic And Extra-Galactic Binary Neutron Stars, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We use 373 hours (≈15 days) of data from the second science run of the LIGO gravitational-wave detectors to search for signals from binary neutron star coalescences within a maximum distance of about 1.5 Mpc, a volume of space which includes the Andromeda Galaxy and other galaxies of the Local Group of galaxies. This analysis requires a signal to be found in data from detectors at the two LIGO sites, according to a set of coincidence criteria. The background (accidental coincidence rate) is determined from the data and is used to judge the significance of event candidates. No inspiral gravitational-wave …

Oceanographic Conditions And Diversity Of Sea Stars (Echinodermata: Asteroidea) In The Gulf Of California, México, Carlos E. Cintra-Buenrostro, Hector Reyes-Bonilla, Maria Dinorah Herrero-Perezrul

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

Species richness is one of the best indicators of biodiversity. However, there are few investigations on concordance of diversity patterns and environmental settings for marine regions. The objectives of this study were to correlate species richness of shallow water (< 200 m deep) sea stars with key oceanographic factors in the Gulf of California, México, and to predict species richness of Asteroidea using multiple regressions. In these analyses the Gulf was divided into nine sections of one degree in latitude (from 23 - 31° N), at each section we recorded: continental shelf area (at 100 and 200 m depth), temperature mean and range at three depth levels (0, 60 and 120 m), thermocline depth, surface nutrient concentrations (nitrates, phosphates and silicates), surface photosynthetic pigment concentration, and integrated productivity. Sea star species richness at each latitudinal section was estimated from literature data, new collections and museum records. Species were assigned to one of the following feeding guilds: predators of small mobile invertebrates (I), detritivores (D), predators of colonial organisms (C), generalist carnivores (G), and planktivores (P). There are 47 shallow water asteroid species in the Gulf of California (16 I, 15 D, eight C, six G, one P and one not assigned). Total species richness and guild species richness showed strong latitudinal attenuation patterns and were higher in the southernmost Gulf, an area characterized by a narrow shelf, high temperature, and low nutrient concentrations. Species diversity for each guild was correlated to a set of oceanographic parameters: temperature, nitrate concentration, and integrated productivity were linked to richness in must cases. We detected that nutrients and surface pigments always presented negative relationships with species richness, indicating that productive environments limit asteroid diversity in the study area. Finally, the postulated regression models to estimate species richness from oceanographic data were significant and highly precise. We conclude that species richness of Asteroidea in the Gulf of California is related to oceanographic conditions and can be estimated from regional oceanographic information.

Electric-Field Generated By The Combustion Of Titanium In Nitrogen, Karen S. Martirosyan, Mona Setoodeh, Dan Luss

Physics and Astronomy Faculty Publications and Presentations

A short temporal electrical impulse (duration of 30–150ms) was generated during the nitridation of mixtures of titanium and titanium nitride by a high temperature moving reaction front. The maximum voltage and current were generated in the combustion front region, in which the conversion of Ti to TiN was incomplete. The electric field (voltage up to 2V and current up to 60mA) decayed and vanished before the maximum combustion temperature was attained. The generation of an electric field during a rapid high-temperature nitridation is most probably due to the different diffusion velocities of charge carriers through the growing titanium nitride shell …

Upper Limits On Gravitational Wave Bursts In Ligo’S Second Science Run, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We perform a search for gravitational wave bursts using data from the second science run of the LIGO detectors, using a method based on a wavelet time-frequency decomposition. This search is sensitive to bursts of duration much less than a second and with frequency content in the 100–1100 Hz range. It features significant improvements in the instrument sensitivity and in the analysis pipeline with respect to the burst search previously reported by LIGO. Improvements in the search method allow exploring weaker signals, relative to the detector noise floor, while maintaining a low false alarm rate, O ( 0.1 ) μ …

Upper Limits From The Ligo And Tama Detectors On The Rate Of Gravitational-Wave Bursts, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We report on the first joint search for gravitational waves by the TAMA and LIGO collaborations. We looked for millisecond-duration unmodeled gravitational-wave bursts in 473 hr of coincident data collected during early 2003. No candidate signals were found. We set an upper limit of 0.12 events per day on the rate of detectable gravitational-wave bursts, at 90% confidence level. From software simulations, we estimate that our detector network was sensitive to bursts with root-sum-square strain amplitude above approximately 1–3×10−19  Hz−1/2 in the frequency band 700-2000 Hz. We describe the details of this collaborative search, with particular emphasis on its advantages …

Search For Gravitational Waves From Primordial Black Hole Binary Coalescences In The Galactic Halo, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics and Astronomy Faculty Publications and Presentations

We use data from the second science run of the LIGO gravitational-wave detectors to search for the gravitational waves from primordial black hole binary coalescence with component masses in the range 0.2–1.0M⊙. The analysis requires a signal to be found in the data from both LIGO observatories, according to a set of coincidence criteria. No inspiral signals were found. Assuming a spherical halo with core radius 5 kpc extending to 50 kpc containing nonspinning black holes with masses in the range 0.2–1.0M⊙, we place an observational upper limit on the rate of primordial black hole coalescence of 63 per year …