Physical Sciences and Mathematics Commons^™

Pmi 5011 Regulates The Ubiquitin Proteasome System In Skeletal Muscle, Heather Christianne Kirk-Ballard

LSU Doctoral Dissertations

Insulin resistance in type 2 diabetes is associated with impaired glucose and protein metabolism in skeletal muscle. The impaired insulin signaling in skeletal muscle affects muscle mass by tilting the balance between skeletal muscle protein synthesis and degradation toward degradation, a process that is primarily regulated by the ubiquitin-proteasome system. Studies have shown that an extensively characterized ethanol extract of Artemisia dracunculus L (Russian Tarragon), termed PMI 5011, enhances insulin signaling in human primary skeletal muscle cells and in a rodent model of insulin resistance. The aim of this project is to determine if the effect of PMI 5011 on …

Chemical Crystallography At The Interface Of Physics, Chemistry, And In Engineering: Structure Determination Of Highly Correlated Extended Solids, Main Group Compounds, Coordination Complexes, And Bioceramics, Gregory Todd Mccandless

LSU Doctoral Dissertations

Multi-disciplinary research is essential to address the major challenges in science, engineering, and medicine. For these three areas, crystallography has played and continues to play a huge role by providing researchers with the means to determine the structure of a compound and relate these to its properties. This dissertation is highly interdisciplinary, focusing on structure determination of complex systems and materials with tailored applications. This work includes the characterization by single crystal and powder X-ray diffraction of intermetallic extended solids, layered metal oxides, inorganic complexes, discrete organic molecules, and bioceramics. These projects range from modeling translational disorder with pseudo-hexagonal symmetry …

Some Tracking Problems For Aerospace Models With Input Constraints, Aleksandra Gruszka

LSU Doctoral Dissertations

We study tracking controller design problems for key models of planar vertical takeoff and landing (PVTOL) aircraft and unmanned air vehicles (UAVs). The novelty of our PVTOL work is the global boundedness of our controllers in the decoupled coordinates, the positive uniform lower bound on the thrust controller, the applicability of our work to cases where the velocity measurements may not be available, the uniform global asymptotic stability and uniform local exponential stability of our closed loop tracking dynamics, the generality of our class of trackable reference trajectories, and the input-to-state stability of the controller performance under actuator errors of …

Perpetual Requirements Engineering, Manuel Alfonso Peralta

LSU Doctoral Dissertations

This dissertation attempts to make a contribution within the fields of distributed systems, security, and formal verification. We provide a way to formally assess the impact of a given change in three different contexts. We have developed a logic based on Lewis’s Counterfactual Logic. First we show how our approach is applied to a standard sequential programming setting. Then, we show how a modified version of the logic can be used in the context of reactive systems and sensor networks. Last but not least we show how this logic can be used in the context of security systems. Traditionally, change …

Operational Methods For Evolution Equations, Lee Gregory Windsperger

LSU Doctoral Dissertations

This dissertation refines and further develops numerical methods for the inversion of the classical Laplace transform and explores the effectiveness of these methods when applied (a) to an asymptotic generalization of the Laplace transform for generalized functions and (b) to the numerical approximation of solutions of ill-posed evolution equations (e.g. backwards in time problems).

Chapter 1 of the dissertation reviews some of the key features of asymptotic Laplace transform theory and its application to evolution equations. Although some of the statements and results contain slight modifications and improvements, the material presented in Chapter 1 is known …

Graham's Variety And Perverse Sheaves On The Nilpotent Cone, Amber Russell

LSU Doctoral Dissertations

In recent work, Graham has defined a variety which maps to the nilpotent cone, and which shares many properties with the Springer resolution. However, Graham's map is not an isomorphism over the principal orbit, and for type A in particular, its fibers have a nice relationship with the fundamental groups of the nilpotent orbits. The goal of this dissertation is to determine which simple perverse sheaves appear when the Decomposition Theorem for perverse sheaves is applied in Graham's setting for type A, and to begin to answer this question in the other types as well. In Chapter 1, we give …

Synthesis, Characterization, And Self-Assembly Of Porphyrins Conjugated To Superparamagnetic Colloidal Particles For Enhanced Photodynamic Therapy, Javoris Hollingsworth

LSU Doctoral Dissertations

Porphyrins and their derivatives are often used as photosensitizers in photodynamic therapy (PDT), which is a noninvasive antitumor treatment. The photochemical process for PDT involves exciting a photosensitizing agent with visible light, which induces cytotoxicity in the presence of oxygen as a result of forming reactive oxygen species (ROS). The ROS are the responsible components for invoking cell death and destruction of tumors. Although this mechanism is an effective cancer therapeutic, it still has many shortcomings. One major challenge of PDT concerns improving the tumor selectivity and specificity of photosensitizers because porphyrins have nonspecific affinity to tumor cells. The discussed …

A New Model For Coalition Formation Games, Alfred Samman

LSU Doctoral Dissertations

We present two broad categories of games, namely, group matching games and bottleneck routing games on grids. Borrowing ideas from coalition formation games, we introduce a new category of games which we call group matching games. We investigate how these games perform when agents are allowed to make selfish decisions that increase their individual payoffs versus when agents act towards the social benefit of the game as a whole. The Price of Anarchy (PoA) and Price of Stability (PoS) metrics are used to quantify these comparisons. We show that the PoA for a group matching game is at most kα …

An Evaluation Of Alternative Approaches For Simulating Animal Movement In Spatially-Explicit Individual-Based Models, Katherine Shepard Watkins

LSU Doctoral Dissertations

Simulating animal movement in spatially-explicit individual-based models (IBMs) is both challenging and critically important to accurately estimating population dynamics. I compared four distinct movement approaches or sub-models (restricted-area search, kinesis, event-based, and run and tumble) in a series of simulation experiments. I used an IBM loosely based on a small pelagic fish that simulated growth, mortality, and movement of a cohort on a 2-dimensional grid. First, I tested the sub-models calibrated (i.e., trained) with a genetic algorithm in one set of environmental conditions in three other novel environments. The sub-models performed well, except restricted-area search and event-based that needed to …

Hadronic Physics From Extensive Air Showers, Guofeng Yuan

LSU Doctoral Dissertations

Although cosmic rays were discovered exactly one century ago, the most fundamental questions about them are still not answered, especially the origin and composition of ultra-high energy cosmic rays (UHECR). The Pierre Auger Observatory (PAO) is constructed with the goal of solving these mysteries. The PAO uses hybrid design and take advantage of both the air fluorescence and surface array technique. Since its debut in 2004, PAO has published several important scientific results.

The most probable candidate for UHECR composition is proton or iron nucleus. The two candidates do show differences in both fluorescence detector (FD) signal and in the …

Investigations Into The Role Of Natural Organic Matter As An Interface Between Aquatic Organisms And Environmental Pollutants, Caroline Lillian Schneider

LSU Doctoral Dissertations

The impact of the continuous pollution of freshwater environments by multiple pollutants has not been well-studied. The goal of this research was to evaluate the toxicity of several modern pollutants in a model environment. The prokaryotic, unicellular blue-green algae Synechocystis WT6803 and the eukaryotic, multicellular Utterbackia imbecillis mussel larvae were studied along with Suwannee River natural organic matter (NOM). The toxicity response of the blue-green algae Synechocystis sp. was measured through changes in growth rates. The inorganic pollutant silver nanoparticles (0.044 μM) were toxic. Gold nanoparticles did not affect the growth rate. The addition of 15 mg/L NOM partially inhibited …

Syntheses And Characterization Of Water-Soluble Phythalocyanines For Diagnosis And Treatment Of Cancer, Benson Getenga Ongarora

LSU Doctoral Dissertations

Ongarora, Benson Getenga, B.S., Moi University, 2005 Doctor of Philosophy, Fall Commencement, 2012 Major: Chemistry Syntheses and Characterization of Water-Soluble Phthalocyanines for Diagnosis and Treatment of Cancer Dissertation directed by Professor M.Graҫa H. Vicente Pages in dissertation, xi. Words in abstract, 251. ABSTRACT Chapter 1 describes the general properties of phthalocyanines, synthesis of metallo-phthalocyanines, their photophysical features and their uses. The concepts of PDT and targeted therapeutics are also introduced. Chapter 2 describes the syntheses, characterization, photophysical studies and biological evaluation of cationic phthalocyanines. The trimethylaminophenoxy substituted phthalocyanines were synthesized through statistical condensation method, which gave a statistical mixture of …

Development Of Innovative Stationary Phases For Chiral And Protein Separations In Open Tubular Capillary Electrochromatography, Leonard Moore, Jr.

LSU Doctoral Dissertations

Protein biomarkers in bodily fluids can lead to an indication of the onset of a disease. Due to low abundance of the biomarker at early stages of the disease and other protein interferences, detection may be challenging. Therefore, in order to achieve more selective protein separations, the development of a novel stationary phase has been investigated. Moreover, novel methods to apply polysaccharides as stationary phases were developed for protein separations as well as chiral separations. The initial discussions in this dissertation commences with the use of novel zwitterionic lysine-based molecular micelles as a coating for open tubular capillary electrochromatography (OT-CEC) …

Detection And Characterization Of Environmentally Persistent Free Radicals (Epfrs) In Soils And Sediments From Superfund Sites, Albert Leo N. Dela Cruz

LSU Doctoral Dissertations

Environmentally persistent free radicals (EPFRs) from combustion-generated PM have been demonstrated to form via reactions of molecular precursors with redox-active transition metals at 150-500C thermal reactions in a few seconds reaction times. While ambient temperatures are much lower, soils/sediments contain similar transition metals, and reaction times of contaminants in soils/sediments are years, rather than seconds. This questions whether EPFRs could be formed at ambient temperatures in soils/sediments from Superfund sites that are contaminated with hazardous materials. Superfund soils contaminated with PCP from Georgia and Montana, and sediments contaminated with PAHs from Washington. Using EPR spectroscopy, EPFR concentrations and structural assignments …

Semantically-Aware Data Discovery And Placement In Collaborative Computing Environments, Xinqi Wang

LSU Doctoral Dissertations

As the size of scientific datasets and the demand for interdisciplinary collaboration grow in modern science, it becomes imperative that better ways of discovering and placing datasets generated across multiple disciplines be developed to facilitate interdisciplinary scientific research.

For discovering relevant data out of large-scale interdisciplinary datasets. The development and integration of cross-domain metadata is critical as metadata serves as the key guideline for organizing data. To develop and integrate cross-domain metadata management systems in interdisciplinary collaborative computing environment, three key issues need to be addressed: the development of a cross-domain metadata schema; the implementation of a metadata management system …

Greenhouse Gas Emissions And Nutrients Dynamics In Restored Wetlands Of The Mississippi River Basin, Christopher Lundberg

LSU Doctoral Dissertations

Greenhouse gases were sampled during spring and summer months in 2010 and 2011 at two sites in the Mississippi River Basin: a riparian forested wetland under restored flood pulsing near Memphis, TN and a coastal estuarine marsh complex impacted by a river diversion at Caernarvon, LA. Mean methane fluxes at Caernarvon (-0.09 g CH4-C m-2 d-1) were lower than those at Memphis (0.53 g CH4-C m-2 d-1), and did not differ between seasons. Nitrous oxide fluxes were generally below detection limits. Fluxes were uncorrelated with water depth, soil temperature, and ambient air temperature, though sampling occurred over a narrow range …

Design And Analysis Of Cloaked Fluorophores For Rapid Detection And Visualization Of Cancer Cells Containing Nad(P)H:Quinone Oxidoreductase-1, William Silvers

LSU Doctoral Dissertations

The development of fluorogenic substrates for real-time tumor cell detection has led to a vastly expanding field for personal oncology. Fluorophores have been studied as appendages to larger scaffolds leading to accumulation of these dyes in tumor cells or their surrounding environment, taking advantage of tumor anatomy. A new class of fluorophores has been developed in which the dye is an active participant in the mechanism of cancer cell detection. These dyes have been conjugated such that their fluorescence has been eliminated or altered and will undergo a change to reveal their fluorescent signal upon activation by a mechanism that …

What Does The ¹⁴C Method For Estimating Photosynthetic Rates In The Ocean Really Measure?, Shaofeng Pei

LSU Doctoral Dissertations

The ¹⁴C method has been used extensively by both limnologists and oceanographers to measure photosynthetic rates in aquatic systems, and the large database of ¹⁴C measurements that now exists is the ground truth with which satellite algorithms for estimating marine photosynthetic rates on a basin and global scale have been calibrated. However, disconcerting uncertainties still remain with respect to whether and under what circumstances the ¹⁴C method provides an estimate of net or gross photosynthesis, or something in between. My study combined batch and continuous culture studies to clarify this ambiguous issue. The batch culture work with …

Habitat Use, Movements, And Ecology Of Female Mottled Ducks On The Gulf Coast Of Louisiana And Texas, Bruce Edward Davis

LSU Doctoral Dissertations

Mottled ducks (Anas fulvigula) are the most abundant breeding waterfowl in the coastal marshes of Louisiana and Texas. Mottled ducks are non-migratory and heavily dependent on coastal marsh habitats; they must satisfy all of their annual resource needs from within the Gulf Coast region. Coastal marsh habitats are being rapidly lost or degraded in Louisiana and Texas. The hydrology of many coastal marsh habitats has been altered by anthropogenic activity and natural factors. Parameters related to Mottled Duck habitat use and movements in this altered environment are poorly understood, and managers need information on vital rates of Mottled Ducks in …

Studies On A Dirhodium Tetraphosphine Hydroformylation Catalyst, Darina Polakova

LSU Doctoral Dissertations

The dirhodium tetraphosphine catalyst [Rh2(nbd)2(rac-et,ph-P4)](BF4)2 was investigated in acetone and water/acetone in order to explain better hydroformylation results in the latter solvent. In-situ NMR spectroscopy showed slower degradation in water/acetone. Less tendency to form penta/hexacarbonyl complexes in water/acetone was shown by 31P{1H} NMR and FT-IR. A pH decrease and hydroformylation studies in presence of a base indicated formation of a monocationic monohydride species. A new reaction mechanism was suggested that takes into account the observed differences from the acetone solvent system. The presence of water enabled production of hydride species when the dirhodium catalyst was exposed to CO gas. We …

Deductive Formal Verification Of Embedded Systems, Zheng Lu

LSU Doctoral Dissertations

We combine static analysis techniques with model-based deductive verification using SMT solvers to provide a framework that, given an analysis aspect of the source code, automatically generates an analyzer capable of inferring information about that aspect.

The analyzer is generated by translating the collecting semantics of a program to a formula in first order logic over multiple underlying theories. We import the semantics of the API invocations as first order logic assertions. These assertions constitute the models used by the analyzer. Logical specification of the desired program behavior is incorporated as a first order logic formula. An SMT-LIB solver treats …

The Effects Of Hydrologic Modifications On Floodplain Forest Tree Recruitment And Growth In The Mississippi River Alluvial Valley, Usa, Hugo Gee

LSU Doctoral Dissertations

Floodplains forests are productive and diverse ecosystems characterized by frequent riverine flooding. Levees and dams have eliminated or altered riverine flooding which can potentially affect floodplain tree recruitment and growth. Increased light availability from canopy disturbances may increase photosynthesis given sufficient soil moisture, but information on the combined effect of canopy disturbances and hydrologic modifications on tree recruitment and growth is lacking. I used dendrochronological techniques to reconstruct tree recruitment, growth (Quercus lyrata, Fraxinus pennsylvanica), and canopy disturbance patterns over a 90-year period at several floodplains in the Mississippi River Alluvial Valley, USA: an unleveed site below dams and two …

Recurrent Novae And Type Ia Supernova Progenitors, Ashley Sara Pagnotta

LSU Doctoral Dissertations

We investigated two types of stellar explosions, recurrent novae (RNe) and Type Ia supernovae (SNe Ia). SNe Ia are the most useful distance markers in astrophysics, but we do not know the identity of their progenitor systems. RNe are good progenitor candidates that consist of a white dwarf (WD) that accretes material from a companion star. The material builds on the surface of the WD until a runaway thermonuclear eruption is triggered, which ejects the accreted material and causes the system to brighten dramatically. We studied the demographics of the nova population and concluded that approximately 25% of classical novae …

Magnetic Compensation In The Bimetallic Oxalates And The Cerium Volume Collapse, Peter Leo Reis

LSU Doctoral Dissertations

In this thesis the author reports his collaborative efforts on two distinct areas of research that has been conducted. The first part of the thesis pertains to the author and his collaborators research on a particular class of organic magnets called the bimetallic oxalates. The main theme of this research was to predict magnetic compensation (magnetization reversal) in unsynthesized bimetallic oxalate structures, motivated by experiments which showed that Fe(II)Fe(III) exhibited magnetic compensation. In addition it was known that a large amount of anisotropy was present in the bimetallic oxalate structure which resulted from the intermediate oxalate molecules between the transition …

C0 Interior Penalty Methods For Cahn-Hilliard Equations, Shiyuan Gu

LSU Doctoral Dissertations

In this work we study C0 interior penalty methods for Cahn-Hilliard equations. In Chapter 1 we introduce Cahn-Hilliard equations and the time discretization that leads to linear fourth order boundary value problems. In Chapter 2 we review related fundamentals of finite element methods and multigrid methods. In Chapter 3 we formulate the discrete problems for linear fourth order boundary value problems with the boundary conditions of the Cahn-Hilliard type, which are called C0 interior penalty methods, and we carry out the convergence analysis. In Chapter 4 we consider multigrid methods for the C0 interior penalty methods. We present two smoothing …

Synthesis And Characterization Of Red And Near-Infrared Bodipy-Based Fluorophores For Various Biological Applications, Timsy Kaur Uppal

LSU Doctoral Dissertations

ABSTRACT 4,4-Difluoro-3a,4a-diaza-s-indacene, better known as BODIPY® dyes, have attracted considerable attention due to their intriguing physicochemical and spectral properties, including high absorption coefficient, fluorescence quantum yield and good photochemical stability. Despite the recent progress achieved in this field, the synthesis of BODIPY derivatives that absorb and emit in the red- and NIR-region of the electromagnetic spectrum and their application to biomolecular targets, represents a long-standing challenge in BODIPY chemistry. This research work is therefore focused on the synthesis and characterization of red and NIR-emissive BODIPY-based fluorophores for various bioanalytical and biomedical applications. Chapter 1 of this dissertation represents a concise …

A Multifaceted Phenomenon Of Hydrophobic Effects: Insights Learned From Nucleation Algorithm Based Computer Simulation Approach, Hyunmi Kim

LSU Doctoral Dissertations

We have applied our new approach, a combination of the AVUS-HR nucleation algorithm and a thermodynamic cycle, to the studies of hydrophobicity-related researches. Due to the multifaceted characteristics of hydrophobicity, it is essential to acquire knowledge in various environments where hydrophobic relevant events occur for comprehensive understanding of this process. In this regards, we have chosen two relatively unstudied hydrophobic subjects for application of our new methodology. For the first subject, hydrophobic association behaviors of a methane pair confined into a nanometer sized hydrophobic cavity have been investigated. Our new approach demonstrates that the association behavior between two methane molecules …

Effects Of Ecotourist Pre-Purchase And External Information Search Behaviors And Strategies On Forest-Based Ecotourism Travel Decisions In Sri Lanka, Rangika T. Perera

LSU Doctoral Dissertations

In the 1980s, the term ecotourism emerged as a direct result of acknowledgment and reaction by travelers to global ecological practices. In reality, the concept of ecotourism carries wide applications, particularly for bio-diverse countries with unique natural attractions. Sri Lanka qualified as such a country, presenting a significant tourism resource base, that display natural and cultural phenomena, including forests, waterfalls, mountains, exotic flora and fauna, and a heritage equally as ancient and as rich as the Greeks and Romans. Ecotourism in today’s dynamic global environment demands that ecotourism operators face a keenly competitive market in order to present an appealing …

Non-Mass Dependent Isotope Fractionation: An Application In The Hyperarid Environment And A Set Of Experiments On Thermal Diffusion, Tao Sun

LSU Doctoral Dissertations

This dissertation consists of two independent topics; both are related to non-mass dependent isotope fractionation. 1) Atacama Gravel Sulfate: The onset of hyperaridity of Atacama Desert is of geological importance and has been controversial. I put constraints this timing by looking into a new record, a deep sulfate profile extending from the surface down to the oxide zone of a copper ore in the Atacama Gravels, whose deposition covers a majority of the Central Depression and temporarily spans from semi-arid to hyper-arid climate. The gravel sulfates show a strong depth-dependent pattern through ~50 meters (15 to 65 meter depth): narrow …

Dynamic Measurements With Scanning Probe Microscopy: Surface Studies Using Nanostructured Test Platforms Of Metalloporphyrins, Nanoparticles And Amyloid Fibrils, Wilson K. Serem

LSU Doctoral Dissertations

A hybrid imaging mode for characterization of magnetic nanomaterials has been developed, using atomic force microscopy (AFM) combined with electromagnetic sample actuation. Instead of using a coated AFM probe as a magnetic sensor; our strategy is to use a nonmagnetic probe with contact mode AFM to characterize the vibration of magnetic and superparamagnetic nanomaterials responding to the flux of an AC electromagnetic field. We refer to the hybrid imaging mode as magnetic sample modulation (MSM-AFM). An oscillating magnetic field is produced by applying an AC current to a wire coil solenoid placed under the sample stage for tuning selected parameters …