Physical Sciences and Mathematics Commons^™

Greedy Methods For Approximate Graph Matching With Applications For Social Network Analysis, Partha Basuchowdhuri

LSU Master's Theses

In this thesis, we study greedy algorithms for approximate sub-graph matching with attributed graphs. Such algorithms find one or multiple copies of a sub-graph pattern from a bigger data graph through approximate matching. One intended application of sub-graph matching method is in Social Network Analysis for detecting potential terrorist groups from known terrorist activity patterns. We propose a new method for approximate sub-graph matching which utilizes degree information to reduce the search space within the incremental greedy search framework. In addition, we have introduced the notion of a “seed” in incremental greedy method that aims to find a good initial …

Convolution Semigroups, Kevin W. Zito

LSU Doctoral Dissertations

In this dissertation we investigate, compute, and approximate convolution powers of functions (often probability densities) with compact support in the positive real numbers. Extending results of Ursula Westphal from 1974 concerning the characteristic function on the interval $[0,1]$, it is shown that positive, decreasing step functions with compact support can be embedded in a convolution semigroup in $L^1(0,infty)$ and that any decreasing, positive function $pin L^1(0,infty)$ can be embedded in a convolution semigroup of distributions. As an application to the study of evolution equations, we consider an evolutionary system that is described by a bounded, strongly continuous semigroup ${T(t)}_{tgeq0}$ in …

Cbod₅ Treatment And Nitrogen Transformations Of The Marshland Upwelling System In Intermediate And Saltwater Marshes, Lorna Anne Putnam

LSU Doctoral Dissertations

The marshland upwelling system (MUS) was designed to treat domestic wastewater from coastal dwellings where conventional methods are inadequate due to high water tables, poor hydraulic soil conditions, anaerobic soils, and saline groundwater. Currently there is no adequate treatment system available and coastal dwellings are contributing to water quality problems. This study focused on determining the treatment effectiveness of the MUS for organic matter and understanding the specific processes involved in nitrogen treatment.

The treatment of organic matter, measured as five-day carbonaceous biological oxygen demand (CBOD₅), was effective in field tests for both saltwater and intermediate marshes. Global …

Remediating Impacts Of Global Climate Change-Induced Submergence On Salt Marsh Ecosystem Functions, Camille Lafosse Stagg

LSU Doctoral Dissertations

Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase the elevation of the marsh surface, thus ameliorating the effects of excessive inundation. Although this technique is growing in popularity, the successful restoration of ecological function after sediment addition has received little attention. The purpose of this research was to determine if sediment subsidized salt marshes are functionally equivalent to natural marshes and whether salt marshes …

Mathematics Grade 8 Leap Scores: A Predictor Of Student Success In Dimensional Analysis?, Martha Lauren Baggett

LSU Master's Theses

This study investigates whether the Mathematics Grade 8 LEAP score can be used to predict student success in a key concept of chemistry, dimensional analysis. Mathematics Grade 8 LEAP scores of 106 ninth grade students enrolled in physical science during the 2008-09 school year were tested for correlations with student performance on a pre-test of dimensional analysis, a post-test of dimensional analysis, and student learning gain. Significant, positive correlations were observed between the Mathematics Grade 8 LEAP scores and the pre-test scores of dimensional analysis scores, the post-test scores of dimensional analysis scores, and the dimensional analysis student learning gain. …

Creep Behavior Of Natural Fiber Reinforced Polymer Composites, Yanjun Xu

LSU Doctoral Dissertations

Creep behavior of natural fiber/polymer composites (NFPCs) was studied in response to the increasing application of this material as structural building products. Factors that influence creep behavior of the composites were investigated by analyzing creep curves of several different NFPC systems, which were designed for overall performance of the composites. Among different models, the 4-element Burgers type was mostly used for quantitative characterization of the creep curves to compare the properties of different composites. The parameters from the 4-element Burgers model were easily interpretable due to their physical meanings. Generalized Burgers models provided better fit by introducing extra Kelvin units, …

Sedimentation On A Mixed Siliciclastic/Carbonate Continental Margin Over Decadal To Millennial Timescales: Gulf Of Papua, Zahid Muhammad

LSU Doctoral Dissertations

Sediments from the Gulf of Papua were examined to estimate particle flux and sediment mass accumulation rates on multiple timescales. Patterns of sediment mass accumulation and inventory-derived 210Pb fluxes display regional variations, decreasing seaward, and along isobaths seaward from the northeastern shelf edge. The amount of terrigenous sediment load being discharged annually from the shelf and accumulating in Pandora Trough is approximately 7-14×106 tonnes. The existence of possible turbidity-current transport and deposition have been documented in deeper parts of the Gulf of Papua. High excess 210Pb fluxes estimated from seabed inventories at the shelf edge and upper slope are consistent …

Do Laminated Sediment-Gravity-Flow Deposits On The Antarctic Peninsula Continental Shelf Record Ice Sheet Grounding Events?, Vincent Clyde Adams

LSU Master's Theses

Barker and Camerlenghi (2002) proposed that drifts on the continental rise of the Antarctic Peninsula may record a high-resolution record of ice-sheet expansions on the adjacent continental shelf. In their view, laminated sediments were deposited during glacial periods, whereas during interglacial periods, sediment supply to drifts was negligible. As a consequence of low sediment supply, the tops of laminated sequences were bioturbated. Therefore, a bioturbated-laiminated couplet should represent a complete glacial cycle. Bioturbated and laminated (B-L) sediment couplets were compiled from cores at two drift sites obtained from Ocean Drilling Program (ODP) Leg 178 Sites 1095, 1096, and 1101. If …

Environmental Influences On The Mobility And Speciation Of Arsenic In The Geothermal Waters Of El Tatio Geyser Field, Chile, Lindsey R. Johnson

LSU Master's Theses

El Tatio geyser field, northern Chile, impacts regional water quality, policy, and agricultural commerce due to the geothermal waters containing high concentrations of naturally-occurring arsenic (As). In the circumneutral pH, non-sulfidic thermal waters at El Tatio, dissolved arsenite [As(III)] dominates geyser discharge water upstream, but dissolved arsenate [As(V)] dominates downstream. Microbial mats and sediments were analyzed for changes in As speciation using X-ray spectroscopy methods, such as XANES and EXAFS at both the As and Fe K-edges, combined with ATR-FTIR spectroscopy and molecular genetics, to understand As cycling. The sediments and microbial mats were dominated by As(V) speciated as both …

Creating An Empirically Derived Community Resilience Index Of The Gulf Of Mexico Region, Ariele Nicole Baker

LSU Master's Theses

As coastal areas increase in populations there is an increasing need to determine what community characteristics are most resilient to coastal disasters. This research proposes two methods to quantify community resilience. The factor analysis method results in a weighted additive index model of six variables to derive community resilience. The index places every community in the Gulf of Mexico on a scale from 0-1. The most resilient counties in the Gulf of Mexico region were found to be Hillsborough, FL, Pinellas, FL, Sarasota, FL, Hernando, FL, Okaloosa, FL, Kenedy, TX, and Jefferson, LA with a resilience score of 1. The …

A Novel Synthesis And Characterization Of Fluorescein Isothiocyanate Labeled Poly(Styrenesulfonate Sodium Salt), Xiaowei Tong

LSU Master's Theses

The diffusion of polyelectrolytes in low-salt or salt-free aqueous solutions is a controversial question. It has been intensively discussed since it was discovered in 1978. Most previous experimental data were obtained from dynamic light scattering (DLS), whose precision, however, was reduced by stringent sample preparation and weak scattering of polyelectrolyte in low-salt solution. For the most commonly studied polyelectrolyte, poly(styrenesulfonate sodium salt) (NaPSS), the harsh polymerization condition and the manufacturing procedure lead to hydrophobic defects and aggregations, which also block a correct insight about the diffusion of polyelectrolyte. In contrast to DLS, fluorescence photobleaching recovery (FPR) directly looks on the …

A Comparative Study Of Geometry Curricula, Robyn Williams Carlin

LSU Master's Theses

In the United States, geometry has long been offered to high school students in the tenth grade. Attempts have been made in recent years to expand the role of geometry across grades Pre-K through twelve. However, based on the latest TIMSS results, although students in the United States made gains in most content areas, they still struggle with geometric concepts compared to their counterparts in other nations of the world, primarily those in certain Asian countries like Singapore and China. We argue that the structure of the curriculum and the instructional strategies used in these countries may lead to more …

Seasonal Variability In Absorption And Fluorescence Properties Of Chromophoric Dissolved Organic Matter In The Barataria Basin, Louisiana, Usa, Shatrughan Singh

LSU Master's Theses

Absorption and fluorescence measurements of chromophoric dissolved organic matter (CDOM) were examined along a transect containing 36 sampling stations in the Barataria Basin during high and low conditions to observe seasonal variation in these optical properties. The objectives of this study were (i) to observe CDOM variability in Barataria Basin in variable flow (high and low) conditions, and to characterize the CDOM, (ii) to identify the constituents of CDOM and to model CDOM compositional variability in the Barataria Basin using parallel factor analysis (PARAFAC). CDOM–salinity relationships were non-conservative in lower and upper part of the transect; however a conservative inverse …

Comparisons Of Boosted Regression Tree, Glm And Gam Performance In The Standardization Of Yellowfin Tuna Catch-Rate Data From The Gulf Of Mexico Lonline [Sic] Fishery, Shane Abeare

LSU Master's Theses

Recent advances in statistical understanding have focused fisheries research attention on addressing the theoretical and statistical issues encountered in standardizing catch-rate data. Similarly, the present study evaluates the performance of boosted regression trees (BRT), the product of recent progress in machine learning technology, as a potential tool for catch-rate standardization. The BRT method provides a number of advantages over the traditional GLM and GAM approaches including, but not limited to: robust parameter estimates as a result of the integrated stochastic gradient boosting algorithm; model structure learned from data and not determined a priori, thereby avoiding assumptions required for model specification; …

Resiliency Of New Orleans Following Hurricane Katrina: A Study Of Communities Three Years After The Storm, Lauren Marie Defrank

LSU Master's Theses

In 2005, Hurricane Katrina and subsequent levee failures produced widespread flooding in New Orleans, Louisiana and forced the evacuation of most of the local population. This event allowed for the study of the community’s resilience, or the ability of a system to absorb changes or perturbations and still function. Statistical analysis and case studies were used to study resilience and answer the following questions. Can natural community recovery models be used when evaluating the population recovery of a human community following a disturbance? Given that there are variations in population recovery patterns, what factors account for this difference in recovery? …

Impact Of Intrafraction Motion On Post-Mastectomy Tomotherapy Of The Chest Wall, Shima Ito

LSU Master's Theses

Purpose: The present work investigates the impact of intrafraction motion of the chest wall due to respiration on Post Mastectomy Radiotherapy (PMRT) with TomoTherapy. The hypothesis of this work is that the impact of intrafraction motion on TomoTherapy PMRT will be insignificant as (1) the largest intrafraction movement of the chest wall (CW) in the medial-lateral, anterior-posterior, and superior-inferior dimensions will not exceed 1 cm and (2) that 95% of in-vivo CW point doses on the patient surface will be within 5% of calculated dose and all doses within 10% of calculated dose. Methods: 4DCT scans were acquired and intrafraction …

Capillary Electrophoretic Separations Of Enzyme Inhibitors With Activity-Based Detection, Xiaoyan Yan

LSU Master's Theses

A technique for separating and detecting enzyme inhibitors was developed using capillary electrophoresis with an enzyme microreactor. The on-column enzyme microreactor was constructed using one or two NdFeB magnets in two configurations to immobilize alkaline phosphatase-coated superparamagnetic beads with diameters of 2.8 µm inside a capillary before the detection window. Enzyme inhibition assays were performed by injecting a plug of inhibitor into a capillary filled with an alkaline phosphatase substrate, AttoPhos. Product generated in the enzyme microreactor was detected by laser-induced fluorescence. Inhibitor zones electrophoresed through the capillary, passed through the enzyme microreactor, and were observed as negative peaks due …

Moderating Effects Of Knowledge, Gender, And Education On The Relationship Between Environmental Value Orientation And Support For Louisiana Coastal Restoration, Meya Voorhies Holloway

LSU Master's Theses

Coastal Louisiana marshes are eroding at a rate equivalent to one football field every thirty minutes. It is vital to understand the perceptions of the American public regarding this issue. I conducted a self-administered mail survey during the spring of 2006. The survey was sent to 4,500 residents living in the Mississippi River Valley. The survey was used to identify respondents environmental value orientations, assess respondents attitudes with regards to support for restoration funding for Louisiana’s coastal wetlands, and to determine if outside moderating effects occurred to make respondents with specific value orientations (Anthropocentric or Biocentric) more likely to support …

The Syntheses Of Methyl Jasmonate And Analogs Of Alpha-Methylene-Gamma-Butyrolactone Utilizing Titanium Medicated Cyclocarbonylation, Steve O. Lawrence

LSU Doctoral Dissertations

From its humble beginnings as a novel carbon–carbon bond forming reaction, the Pauson–Khand reaction has lead to the synthetic development of a variety of natural products. One particular variation of the Pauson–Khand reaction was called the hetero Pauson–Khand. This reaction differs from the normal Pauson–Khand reaction because the reaction employs an intramolecular titanium mediated cycloaddition using enal and enones instead of alkenes and alkynes functional groups to prepare a variety of natural products. These natural products usually contain a bicyclic cyclopentenone core. Because the new ring contains a hetero atom, the name hetero Pauson–Khand was coined. Alpha–Methylene–Gamma–Butyrolactones posses a wide …

Topics In Quantum Optical Metrology, Aravind Chiruvelli

LSU Doctoral Dissertations

Quantum optical metrology deals with estimation of an unknown parameter by exploiting the non-classical properties of the light. The unknown parameter that we are trying to estimate is the optical phase. Precise optical phase measurement has been a well-known problem and has many applications, most notably the gravitational wave detection. In this thesis we investigate the interferometric measurement schemes. We consider the parity detection for a class of input states that have been shown to exhibit sub-shot noise limited phase estimate with their respective detection schemes. Our results indicate that the parity detection applies to all these strategies with various …

A Geochemical Paleoecological Analysis Of Miocene Mammalian Mega Fauna Of Fort Polk, Louisiana, Travis Lamar Atwood

LSU Master's Theses

Through a combination of vertebrate paleontology and geochemistry much can be discovered about the environments about the past. Fort Polk’s vertebrate fossil sites are important because they reflect a time when the Antarctic ice cap was just beginning to form during the middle Miocene cooling period just after the middle Miocene Climatic Optimum (~15Ma). This study tested the hypothesis that Miocene seasonality will be preserved in the isotopic geochemistry of terrestrial vertebrate remains at central North American Gulf Coastal sites. Geochemistry was used to understand fossil diagenesis, faunal communities and paleoenvironments. Fort Polk, LA sites range in age from 13.5 …

Distribution And Habitat Associations Of Breeding Secretive Marsh Birds In The Mississippi Alluvial Valley Of Northeast Louisiana, Jonathon Joseph Valente

LSU Master's Theses

Populations of many North American secretive marsh birds (SMBs) have declined over the past 30 years, primarily as a function of wetland loss. Ranges for many of these species encompass Louisiana and researchers have investigated various characteristics associated with breeding populations in coastal wetlands, yet similar knowledge is lacking for other parts of the state. I investigated distributions and habitat characteristics associated with breeding SMBs in wetlands and rice fields of the lower Mississippi Alluvial Valley (MAV) of northeast Louisiana. In the 2007 and 2008 breeding seasons we conducted repeated bird surveys in 118 wetlands and 76 rice fields. Common …

Oil Platforms And Red Snapper Movement And Behavior, Michael Mcdonough

LSU Master's Theses

Understanding the behavior, including movement, of red snapper (Lutjanus campechanus), around and among the many oil and gas platforms in the northern Gulf of Mexico (GOM) is crucial to the management of this important commercial and recreational species. What role oil and gas production platforms play in the attraction vs. production continuum for red snapper is unknown, but it is certain these large structures have a role at some life history stage. We used the VRAP acoustic telemetry system to track red snapper around two platforms in the GOM in 2005 and 2006. Fish detections per hour generally decreased over …

Amyloid Aggregation-Mitigating Peptides As Potential Alzheimer's Drugs, Cyrus Kipkurui Bett

LSU Doctoral Dissertations

Neuronal cytotoxicity observed in Alzheimer¡¦s disease (AD) is linked to the aggregation of £]-amyloid peptide (A£]) into toxic forms. Increasing evidence points to oligomeric species as the neurotoxic species compared to fibrils; disruption or inhibition of A£]ƒnself-assembly into oligomeric or fibrillar forms remains a viable therapeutic strategy to reduce A£] neurotoxicity. Amyloid aggregation mitigating peptides (AAMPs) were designed based on the A£]ƒn¡§hydrophobic core¡¨ A£]17-20, with C£\,£\-disubstituted amino acidsƒnƒv£\£\AAs) added into this core as disrupting agents. The number, distribution, and side chain functionality of £\£\AAs incorporated into the mitigator sequence was found influences the resultant aggregate morphology as indicated by ex-situ …

Quantum Optical Improvements In Metrology, Sensing, And Lithography, Sean Ducharme Huver

LSU Doctoral Dissertations

In this dissertation we begin with a brief introduction of quantum mechanics, its impact on technology in the 20th century, and the likely impact quantum optics will have on the next generation of technology. The following chapters display research performed in many of these next generation areas. In Chapter 2 we describe work performed in the area of designing quantum optical logic gates for use in quantum computing. In Chapter 3 we discuss findings made in regards to using quantum states of light for remote sensing and imaging. We move on to Fabry-Perot interferometers in Chapter 4 and show discoveries …

Polymer-Based Microfluidic Devices For High Throughput Single Molecule Detection: Applications In Biological And Drug Discovery, Paul Ichide Okagbare

LSU Doctoral Dissertations

The realization of high throughput sample processing has become a primary ambition in many research applications with an example being high throughput screening (HTS), which represents the first step in the drug discovery pipeline. Microfluidics is a viable platform for parallel processing of biochemical reactions to increase data production rates due to its ability to generate fluidic networks with a high number of processors over small footprints suitable for optical imaging. Single-molecule detection (SMD) is another technology which has emerged to facilitate the realization of high throughput data processing afforded by its ability to eliminate sample processing steps and generate …

Quantum Nonlinear Optics: Applications To Quantum Metrology, Imaging, And Information, Ryan Glasser

LSU Doctoral Dissertations

The fields of quantum and nonlinear optics have given rise to a variety of nonclassical states of light that have been proven to surpass certain limitations set by classical physics. Namely, certain squeezed and entangled states have been shown to beat the shot-noise limit when making precision phase measurements in interferometry, as well as write lithographic patterns that are smaller than classically allowed by the Rayleigh diffraction limit. Additionally, single-photon sources and entangled photon pairs have given rise to provably secure quantum key distribution for cryptography. Producing these quantum states of light has proven a difficult task. Nonlinear crystals, when …

Testing Of Gdcl3 Doping In Water Cherenkov Antineutrino Detectors, William Fitzgerald Coleman

LSU Doctoral Dissertations

Improved neutron and neutrino detection using water Cherenkov detectors loaded with gadolinium has been proposed for potential application in both large and small volume detectors. In this thesis, work performed to determine the effect on transparency resulting from use of GdCl3 in stainless steel constructed water Cherenkov detectors is presented. In addition, results of an experiment performed using a small volume water Cherenkov de- tector are reported. This was the first use of gadolinium loaded water to detect reactor antineutrinos.

Derivatization Of Porphyrins For Dna And Metal Ion Binding, Especially By Employing Secondary Sulfonamide Links, Janet Manono

LSU Doctoral Dissertations

Porphyrins are of exceptional importance in nature, science and technology: For instance, as ligands for metals in supramolecular synthesis, as photosenstizers in photodynamic therapy (PDT), and as building blocks for electronic devices. In addition to their application in cancer therapy, porphyrin species also exhibit antiviral activity. New meso-tetraarylporphyrins (TArP, Ar = -C₆H₄-) of the general formula, T(R¹R²NSO₂Ar)P, with R¹ = N-py-n-CH₂ (n = 2, 3 or 4) or SO₃^- and R² = H or CH₃ were synthesized. These groups were linked to the …

Computational Studies Of The Properties Of Copper Oxide Clusters And The Reactions Of Phenol And Chlorinated Phenols With Copper Oxide Clusters, Gyun-Tack Bae

LSU Doctoral Dissertations

We used ab initio simulations and calculations to study the structures and stabilities of copper oxide clusters, CunOn (n=1-8) and CuOn (n=1-6). The lowest energy structures of neutral and charged copper oxide clusters were determined using primarily the B3LYP/LANL2DZ model chemistry. In CunOn clusters with n=1-8, a transition from planar to nonplanar geometries occurs at n=4. In CuOn clusters with n=1-6, all geometries of neutral, positively, and negatively charged clusters are planar or near planar structures. Selected electronic properties, including binding energies, ionization energies, and electronic affinities, were calculated and examined as a function of n. Stabilities were examined by …