Physical Sciences and Mathematics Commons^™

Feasibility Of The Debris Ring Transit Method For The Solar-Like Star Hd 107146 By An Occulted Galaxy, L. Van Sluijs, D. A.J.H. Vaendel, Benne W. Holwerda, M. A. Kenworthy, G. Schneider

Faculty and Staff Scholarship

Occulting galaxy pairs have been used to determine the transmission and dust composition within the foreground galaxy. Observations of the nearly face-on ring-like debris disc around the solar-like star HD 107146 by HST/ACS in 2004 and HST/STIS in 2011 reveal that the debris ring is occulting an extended background galaxy over the subsequent decades. Our aim is to use 2004 Hubble Space Telescope (HST) observations of this system to model the galaxy and apply this to the 2011 observation in order to measure the transmission of the galaxy through the outer regions of the debris disc. We model the galaxy …

Herschel Observations Of Edge-On Spirals (Heroes) Iv. Dust Energy Balance Problem, Aleksandr V. Mosenkov, Flor Allaert, Maarten Baes, Simone Bianchi, Peter Camps, Christopher J.R. Clark, Marjorie Decleir, Gert De Geyter, Ilse De Looze, Jacopo Fritz, Gianfranco Gentile, Benne W. Holwerda, Thomas M. Hughes, Fraser Lewis, Matthew W.L. Smith, Joris Verstappen, Sam Verstocken, Sébastien Viaene

Faculty and Staff Scholarship

We present results of the detailed dust energy balance study for the seven large edge-on galaxies in the HEROES sample using three-dimensional (3D) radiative transfer (RT) modelling. Based on available optical and near-infrared (NIR) observations of the HEROES galaxies, we derive the 3D distribution of stars and dust in these galaxies. For the sake of uniformity, we apply the same technique to retrieve galaxy properties for the entire sample: we use a stellar model consisting of a Sérsic bulge and three double-exponential discs (a superthin disc for a young stellar population and thin and thick discs for old populations). For …

A Land Use Regression Model For Explaining Spatial Variation In Air Pollution Levels Using A Wind Sector Based Approach, Owen Naughton, Aoife Donnelly, Paul Nolan, Francesco Pilla, Bruce Misstear, Brian Broderick

Articles

Estimating pollutant concentrations at a local and regional scale is essential for good ambient air quality information in environmental and health policy decision making. Here we present a land use regression (LUR) modelling methodology that exploits the high temporal resolution of fixed-site monitoring (FSM) to produce viable air quality maps. The methodology partitions concentration time series from a national FSM network into wind-dependent sectors or “wedges”. A LUR model is derived using predictor variables calculated within the directional wind sectors, and compared against the long-term average concentrations within each sector. This study demonstrates the value of incorporating the relative position …

Unprecedented In Vitro Antitubercular Activitiy Of Manganese(Ii) Complexes Containing 1,10- Phenanthroline And Dicarboxylate Ligands: Increased Activity, Superior Selectivity, And Lower Toxicity In Comparison To Their Copper(Ii) Analogs, Pauraic Mccarron, Malachy Mccann, Michael Devereux, Kevin Kavanagh, Ciaran M. Skerry, Petros C. Karakousis, Ana Carolina Aor, Thaís P. Mello, Dos Santos, André Luis Souza Dos Santos, André Luis Souza, Débora Leite Campos, Fernando R. Pavan

Articles

Mycobacterium tuberculosis is the etiologic agent of tuberculosis. The demand for new chemotherapeutics with unique mechanisms of action to treat (multi)resistant strains is an urgent need. The objective of this work was to test the effect of manganese(II) and copper(II) phenanthroline/dicarboxylate complexes against M. tuberculosis. The water-soluble Mn(II) complexes, [Mn2(oda)(phen)4(H2O)2][Mn2(oda)(phen)4(oda)2]·4H2O (1) and ([Mn(3,6,9-tdda)(phen)2]·3H2O·EtOH)n (3) (odaH2 = octanedioic acid, phen = 1,10-phenanthroline, tddaH2 = 3,6,9-trioxaundecanedioic acid), and water-insoluble complexes, [Mn(ph)(phen)(H2O)2] (5), [Mn(ph)(phen)2(H2O)]·4H2O (6), [Mn2(isoph)2(phen)3]·4H2O (7), ([Mn(phen)2(H2O)2])2(isoph)2(phen)·12H2O (8) and [Mn(tereph)(phen)2]·5H2O (9) (phH2 = phthalic acid, isophH2 = isophthalic acid, terephH2 = terephthalic acid), robustly inhibited the viability of M. tuberculosis strains, H37Rv …

Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Patrick Cullen, Vladimir Milosavljević

Articles

The use of plastics has spanned across almost all aspects of day to day life. Although their uses are invaluable, they contribute to the generation of a lot of waste products that end up in the environment and end up polluting natural habitats such as forests and the ocean. By treating low-density polyethylene (LDPE) samples with non-thermal plasma in ambient air and with an addition of ≈4% CO2, the biodegradation of the samples can be increased due to an increase in oxidative species causing better cell adhesion and acceptance on the polymer sample surface. It was, however, found that the …

Targeting The Folate Receptor: Improving Efficacy In Inorganic Medicinal Chemistry, Pauraic Mccarron, Aisling Crowley, Denis O'Shea, Malachy Mccann, Orla L. Howe, Mary Hunt, Michael Devereux

Articles

The discovery of the high-affinity, high-specificity folate receptor in mamalian kidney cells, coupled with the ability of folate to enter cells by folate receptor-mediated endocytosis and the subsequent elucidation of the folate receptor’s overexpression in specific cancer cell types; heralded the arrival of the area of chemotherapeutic folate targeting. The application of purely organic folate-based small-molecule drug conjugates that selectively target the folate receptor, which is over expressed in several diseases such as cancer, is well established. The application of inorganic folate-targeted drugs offers significant potential to expand and enhance this therapeutic approach. From the data made available to date, …

Chemical Modifications Of Lipids And Proteins By Nonthermal Food Processing Technologies, Juan M. PéRez-AndréS, CléMentine Charoux, Patrick J. Cullen, Brijesh K. Tiwari

Articles

A range of nonthermal techniques have demonstrated process efficacy in ensuring product safety, extension of shelf life, and in general a retention of key quality attributes. However, various physical, chemical and biochemical effects of nonthermal techniques on macro and micro nutrients are evident, leading to both desirable and undesirable changes in food products. The objective of this review is to outline the effects of nonthermal techniques on food chemistry and the associated degradation mechanisms with the treatment of foods. Oxidation is one of the key mechanisms responsible for undesirable effects induced by nonthermal techniques. Degradation of key macromolecules largely depends …

Prediction Intervals For Functional Data, Nicholas Rios

Theses, Dissertations and Culminating Projects

The prediction of functional data samples has been the focus of several functional data analysis endeavors. This work describes the use of dynamic function-on-function regression for dynamic prediction of the future trajectory as well as the construction of dynamic prediction intervals for functional data. The overall goals of this thesis are to assess the efficacy of Dynamic Penalized Function-on-Function Regression (DPFFR) and to compare DPFFR prediction intervals with those of other dynamic prediction methods. To make these comparisons, metrics are used that measure prediction error, prediction interval width, and prediction interval coverage. Simulations and applications to financial stock data from …

Presence Of Cofactor Nadph Slows Down The Dissociation Of Methotrexate From Dihydrofolate Reductase From Bacillus Stearothermophilus, Ryan Seamus Foley

Theses, Dissertations and Culminating Projects

The goal of this project was to study the effect of the presence or absence of the cofactor NADPH on the binding and release of ligand methotrexate (MTX) to/from Bacillus stearothermophilus (Bs) dihydrofolate reductase (DHFR). A previously developed, fluorescently-labeled Bs DHFR (C73A/S131CMDCC DHFR) was used to investigate the kinetics and protein conformational motions associated with the binding of NADPH and the binding of methotrexate to the holoenzyme. This Bs DHFR contains a distal cysteine where the fluorophore, N-[2-(1-maleimidyl)ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC) can be covalently attached. This probe is sensitive to the local molecular environment, reporting on changes in the protein conformation associated …

Bridging Gaps Between Conservation Action And Policy On Small Island Developing States – Case Analog Of The Republic Of Mauritius, Pricila Iranah

Theses, Dissertations and Culminating Projects

Mauritius, a small island state in the Indian Ocean, is a biodiversity hotspot with highly threatened forest ecosystems. It is also a country where environmental and conservation programs have been successful in the past. However, the issue of funding has received relatively less attention and national park systems are chronically underfunded. As part of assessing the potential for local funding, we assessed the demand for forest recreation. Recreation in forest ecosystems is one of the cornerstones of modern nature-based tourism. Tourism is increasingly a favored tool to promote conservation of natural forests, especially in developing countries where conservation financing can …

Fabrication And Application Of Functional Polymer-Protein Coreshell Nanoparticles, Lin Lu

Theses and Dissertations

The study of polymer-protein nanoparticles is of increasing interest due to their various potential applications in biosensing, imaging, bioseparations, gene and drug delivery, etc. Synthetic polymers can be tailored with different functional groups and properties, therefore, they can serve as platforms to impart proteins with additional features and assist proteins to better perform biological functions. In this dissertation work, we were mainly focusing on the preparation of polymer-protein core-shell nanoparticles by synthesizing new functional polymers and assembling them with proteins for different applications. In chapter 1, a pyridine grafted diblock copolymer P(CL-g-Py)-b-PCL was prepared through ROP and CuAAC reactions. …

Graph Homomorphisms And Vector Colorings, Michael Robert Levet

Theses and Dissertations

A graph vertex coloring is an assignment of labels, which are referred to as colors, such that no two adjacent vertices receive the same color. The vertex coloring problem is NP-Complete [8], and so no polynomial time algorithm is believed to exist. The notion of a graph vector coloring was introduced as an efficiently computable relaxation to the graph vertex coloring problem [7]. In [6], the authors examined the highly symmetric class of 1-walk regular graphs, characterizing when such graphs admit unique vector colorings. We present this characterization, as well as several important consequences discussed in [5, 6]. By appealing …

The South Carolina Safety Belt Study: Large-Scale Location Sampling, Stephanie Jones

Theses and Dissertations

The South Carolina Safety Belt Study is a statewide survey completed yearly to assess the prevalence of safety belt usage on of South Carolina roads through observations from different locations across the state. Every five years the sites for observation are resampled. This thesis breaks down the most recent sampling done for the years of 2018 through 2022. Both the methodology of large scale location sampling and the mathematical idea behind the strategy employed are covered. Further, three different software packages were utilized: R, SAS, and ArcGIS. The steps that were taken and the written function code run for each …

Classical And Quantum Kac’S Chaos, Rade Musulin

Theses and Dissertations

In 1956 Kac studied the Boltzmann equation, an integro-differential equation which describes the density function of the distribution of the velocities of the molecules of dilute monoatomic gases under the assumption that the energy is only transferred via collisions between the molecules. In an attempt at a solution to the Boltzmann equation, Kac introduced a property of the density function that he called the “Boltzmann property" which describes the behavior of the density function at a given fixed time as the number of particles tends to infinity. The Boltzmann property has been studied extensively since then, and has been abstracted …

Improving Speech-Related Facial Action Unit Recognition By Audiovisual Information Fusion, Zibo Meng

Theses and Dissertations

In spite of great progress achieved on posed facial display and controlled image acquisition, performance of facial action unit (AU) recognition degrades significantly for spontaneous facial displays. Furthermore, recognizing AUs accompanied with speech is even more challenging since they are generally activated at a low intensity with subtle facial appearance/geometrical changes during speech, and more importantly, often introduce ambiguity in detecting other co-occurring AUs, e.g., producing non-additive appearance changes. All the current AU recognition systems utilized information extracted only from visual channel. However, sound is highly correlated with visual channel in human communications. Thus, we propose to exploit both audio …

Comparison Of The Performance Of Simple Linear Regression And Quantile Regression With Non-Normal Data: A Simulation Study, Marjorie Howard

Theses and Dissertations

Linear regression is a widely used method for analysis that is well understood across a wide variety of disciplines. In order to use linear regression, a number of assumptions must be met. These assumptions, specifically normality and homoscedasticity of the error distribution can at best be met only approximately with real data. Quantile regression requires fewer assumptions, which offers a potential advantage over linear regression. In this simulation study, we compare the performance of linear (least squares) regression to quantile regression when these assumptions are violated, in order to investigate under what conditions quantile regression becomes the more advantageous method …

Dimension Reduction For Classification With Many Covariates And Pathway Activity Level Estimation, Seungchul Baek

Theses and Dissertations

The development of science and technology has enabled the use of more covariates. As a result, it has become more difficult to identify dependencies among many covariates. Dimension reduction provides an efficient way to handle this issue by summarizing the effect of covariates via a few linear combinations of covariates. In this dissertation, two methodologies for real-life problems are provided by using dimension reduction equipped with semiparametric theory. The use of semiparametrics allows maximal flexibility of the model by letting some features of the model completely unspecified, while we still enjoy the interpretability of the model through estimating the parameters …

Theory, Computation, And Modeling Of Cancerous Systems, Sameed Ahmed

Theses and Dissertations

This dissertation focuses on three projects. In Chapter 1, we derive and implement the compact implicit integration factor method for numerically solving partial differential equations. In Chapters 2 and 3, we generalize and analyze a mathematical model for the nonlinear growth kinetics of breast cancer stem cells. And in Chapter 4, we develop a novel mathematical model for the HER2 signaling pathway to understand and predict breast cancer treatment. Due to the high order spatial derivatives and stiff reactions, severe temporal stability constraints on the time step are generally required when developing numerical methods for solving high order partial differential …

Estimation Procedures For Complex Survival Models And Their Applications In Epidemiology Studies, Jie Zhou

Theses and Dissertations

In this dissertation, we aim to address three important questions in practice, which can be solved through complex survival models. The first project focuses on studying the longitudinal fitness effect on cardiovascular disease (CVD) mortality. In the second project, we study the disease-death relation between CVD and all-cause mortality and evaluate important covariate effects on the disease or death transitions. In the third project, we compare antiretroviral treatment (ART) for HIV patients and consider both treatment effect and side effect of the drugs. The first two projects are motivated by the Aerobics Center Longitudinal Study (ACLS) datasets and the third …

Two-Electrode Measurements Of Electrostatic Double Layer Potentials With Atomic Force Microscopy, Jason Giamberardino

Theses and Dissertations

In this dissertation, I provide a thorough description of my development of theoretical, analytical, and experimental techniques pertaining to novel measurements of the electrostatic double layer (EDL) using atomic force microscopy (AFM), among other techniques. The EDL refers to the structure formed by ions that exists at the interface between a solid and a liquid. The EDL is an important physical element of many systems and its behavior has been of interest to scientists for many decades. Because many areas of science and engineering are moving to test, build, and understand systems at smaller and smaller scales, this work focuses …

Authenticating Users With 3d Passwords Captured By Motion Sensors, Jing Tian

Theses and Dissertations

Authentication plays a key role in securing various resources including corporate facilities or electronic assets. As the most used authentication scheme, knowledgebased authentication is easy to use but its security is bounded by how much a user can remember. Biometrics-based authentication requires no memorization but ‘resetting’ a biometric password may not always be possible. Thus, we propose study several behavioral biometrics (i.e., mid-air gestures) for authentication which does not have the same privacy or availability concerns as of physiological biometrics.

In this dissertation, we first propose a user-friendly authentication system Kin- Write that allows users to choose arbitrary, short and …

Block Copolymer Control Of Nanoscale Porous Materials, Amrita Sarkar

Theses and Dissertations

The controlled fabrications of porous materials are crucial for a wide variety of uses spanning the gamut from energy applications to filtration. Despite decades of developments based upon block copolymer self-assembly there remain numerous limitations to achieve simple ends such as fully-tunable nanomaterials or well-defined macroscopic forms. For example, fundamental studies of nanostructure-performance relationships need systematic series of nanomaterials to identify the separate effects of wall and pore dimensions. Such precision control is impossible under the constraints of equilibrating systems. Persistent Micelle Templating (PMT) is rather based on kinetic control and enables robust and independent tuning of each feature. However, …

Structural Transformations Of Multimetallic Nanoparticles, Guangfang Li

Theses and Dissertations

Atomic-level understanding of the structural transformations of multimetallic nanoparticles (NPs) triggered by external stimuli is of vital importance to the enhancement of our capabilities to precisely fine-tailor the key structural parameters and thereby to fine-tune the catalytic properties of the NPs. In this work, I firstly show that Au-Cu bimetallic NPs demonstrate stoichiometry-dependent architectural evolutions during chemical dealloying processes and nanoporosity-evolving percolation dealloying only occurs for Au-Cu alloy NPs with Cu atomic fractions above the parting limit. The electrochemically active surface area and the specific activity of the dealloyed nanoframes can be systematically tuned to achieve the optimal electrocatalytic activity. …

Ecology And Virulence Capabilities Of Vibrios Isolated From The Pristine North Inlet Estuary, Savannah Leigh Klein

Theses and Dissertations

Vibrio bacteria are Gram negative, motile organisms that occur naturally in most coastal and estuarine ecosystems. Some vibrios are important human pathogens, including Vibrio parahaemolyticus and Vibrio vulnificus. The CDC estimates that vibrios cause 80,000 cases of disease each year in the United States alone. Most cases are caused by V. parahaemolyticus, which infects humans after the consumption of contaminated raw or undercooked seafood, primarily oysters. V. parahaemolyticus causes mild gastroenteritis that is self-limiting unless the patient is immunocompromised. V. vulnificus has a much lower incidence of disease (100 cases in the USA yr-1); however, this organism causes much more …

Hydrothermal Synthesis: A Gateway To Metastable Crystals With Unusual Properties, Justin B. Felder

Theses and Dissertations

Research into crystalline matter has long been of interest to humanity, both in order to advance our society by creating new technologically useful materials and in order to better understand to nature of the properties we depend on for so much of our existing technology. In recent decades, solution-based crystal growth syntheses including hydrothermal and molten flux techniques have risen to the forefront of solid-state chemistry as superior methods of synthesizing new materials as single crystals ripe for structure determination and property measurements.

This work seeks to educate readers on recent advances in the hydrothermal realm of crystal growth: namely …

Probing Solvent Effects In Aromatic Interactions Using Molecular Balances, Josef M. Maier

Theses and Dissertations

Aromatic interactions play a key role in many important processes, such as the formation and stability of biological and synthetic assemblies, facilitation of molecular recognition processes, and catalysis of chemical reactions. One of the key factors determining the strength of aromatic interaction is the solvent environment. Therefore, developing model systems that can accurately measure the influence or effects of solvents on non-polar interaction strengths is a task of great importance. Over the years, we have been approaching this challenge via designing and analyzing molecular devices that can quantitatively report aromatic interaction energies under various solvent and chemical environments. With this …

Classification Of High-Dimensional Data Based On Multiple Testing Methods, Chong Ma

Theses and Dissertations

Supervised and unsupervised classification are common topics in machine learning in both scientific and industrial fields, which usually involve three tasks: prediction, exploration, and explanation. False discovery rate (FDR) theory has a close connection to classical classification theory, which must be employed in a sophisticated way to achieve good performance in various contexts. The study aims to explore novel supervised classifiers and unsupervised classification approaches for functional data and high-dimensional data in genome study by using FDR, respectively. One work develops a novel classifier for functional data by casting the classification problem into a multiple testing task, which involves using …

Synthesis Of Small-Molecule Fluorescent Probe And Polymers For Bioapplication: Bioimaging And Enzyme Stabilization, Yanmei Xu

Theses and Dissertations

In chapter one, we designed, synthesized and characterized two cysteine sensors CCPAP and CCPAN, with improved water solubility, cell penetration ability, and potential targeting selectivity. Two types of positive charged groups, i.e. triphenylphosphonium and pyridinium were introduced respectively to the frame structure CCP by coupling carboxylic acid with amine to improve the cell permeability and cysteine selectivity. ESI-MS, NMR and IR were employed to characterize the molecular structures of the two novel probes. These probes have better water solubility than the parent molecule DCP, and better cell penetration capability than CEP, which could further distinguish the cysteine concentration differences in …

Quick Trips: On The Oriented Diameter Of Graphs, Garner Paul Cochran

Theses and Dissertations

In this dissertation, I will discuss two results on the oriented diameter of graphs with certain properties. In the first problem, I studied the oriented diameter of a graph G. Erdos et al. in 1989 showed that for any graph with |V | = n and δ(G) = δ the maximum the diameter could possibly be was 3 n/ δ+1. I considered whether there exists an orientation on a given graph with |G| = n and δ(G) = δ that has a small diameter. Bau and Dankelmann (2015) showed that there is an orientation of diameter 11 n/ δ+1 + …

Mechanisms Of Decarboxylation In The Cyp152 Family Of Cytochrome P450s, José Armando Amaya

Theses and Dissertations

Intense interest has focused on the development of enzymes as next-generation catalysts for the production of molecules with biotechnological potential. OleTJE, a member of the cytochrome P450 CYP152 family is an excellent candidate for the generation of advanced biofuels. OleTJE catalyzes the hydrogen peroxide-dependent decarboxylation of Cn fatty acids to produce Cn-1 terminal alkenes. Despite the ability of this enzyme to yield long chain alkenes with nearly exclusive chemoselectivity, its reactivity towards shorter chain length substrates results in undesired levels of hydroxylated side-products, limiting its industrial potential. Previous transient kinetic studies have demonstrated that, despite its unusual chemistry, the reaction …