Physical Sciences and Mathematics Commons^™

Characterization Of The Role Of Fro6 In Metal Homeostasis In Arabidopsis Thaliana, Margo Ellen Maynes

Theses and Dissertations

Iron deficiency is the most common human nutritional disorder in the world today, affecting approximately 2 billon people worldwide, almost a third of the world's population. For most of the world's population, plant foods serve as the major source of dietary iron. One approach that may contribute towards the solution of iron deficiency is the development of crop plants that contain higher levels of bioavailable iron. This project focuses on FRO6, a ferric chelate reductase in Arabidopsis thaliana that is thought to reduce apoplastic iron for transport across the plasma membrane in leaf cells. We hypothesize therefore that FRO6 controls …

Environmental Pre-Conditioning Of Bacterial Populations And Communities To Extreme Acidity, Gabriel Joseph Swenson

Theses and Dissertations

The ability of opportunistic enteric pathogens to cause disease is effected by their ability to survive the variable and lethal acidity of the mammalian host gastrointestinal milieu. In many of these pathogens, survival is conferred by an acid stress response (ASR). ASR is elicited when bacterial cells are pre-conditioned in sub-lethal acidity (pH 4-6) which induces rapid biochemical and physiological modifications and facilitates survival when extreme acidity (pH 1-3) is encountered. In Vibrio cholerae, the causative agent of the diarrheal disease Cholera, ASR was initially investigated in an effort to determine how this ubiquitous aquatic bacterium is capable of causing …

The Role Of Reactive Oxygen Species In Cell Death Induced By Thymidylate Synthase Inhibitors, Ufuk Ozer

Theses and Dissertations

Thymidylate synthase (TS) catalyzes the reductive transfer of a methyl group from N5,N10-methylenetetrahydrofolate (CH₂-THF) to dUMP, forming dTMP and dihydrofolate (DHF). It is generally accepted that inhibition of the enzyme leads to a deficiency of dTMP, followed by genome damage and programmed cell death. As such, TS has long been viewed as an important target of anti-neoplastic agents, such as 5-fluorouracil (5-FU) and raltitrexed (RTX), which lead to inhibition of the enzyme. Oxidative stress is well-recognized as having a central role in cellular response to a number of DNA damaging agents, and may be a proximate cause of …

The Role Of Host-Tumor Interactions In Liver Metastasis Of Colorectal Cancer, Yu Zhang

Theses and Dissertations

Colon cancer is the third most frequent cancer and the second leading cause of cancer deaths in the United States. Liver metastasis is the major cause of death in colon cancer. Successful metastases depend on productive collaborations between tumor cells and host-derived cells in the tumor microenvironment, target organ environments, and cells in the hematopoietic compartment.

To identify the host-tumor interactions promoting liver metastasis and their molecular and cellular mediators, an orthotopic mouse model of liver metastasis of colon cancer was established that recapitulates all stages of tumor growth and metastasis. A highly metastatic mouse carcinoma cell line CT26-FL3 was …

Development And Figures Of Merit Of Microextraction And Ultra-Performance Liquid Chromatography For Forensic Characterization Of Dye Profiles On Trace Acrylic, Nylon, Polyester, And Cotton Textile Fibers, Scott James Hoy

Theses and Dissertations

Methodology for the microextraction of basic dyes on acrylic, acid dyes on nylon, disperse dyes on polyester, and reactive dyes, direct dyes, and indigo on cotton textile fibers is reported. Although these processes are destructive to the fiber evidence, the ability to analyze dye extracts from sub-millimeter fiber lengths of single fibers, coupled with detection limits in the hundred picogram range by ultra-performance liquid chromatography (UPLC) with both diode array detection (DAD) and tandem mass spectrometry (MS-MS) makes routine forensic characterization feasible.

Microextraction, followed by UPLC, can often distinguish similar fibers containing different, but similar, dyes with the combination of …

Design And Synthesis Of Polymer-Based Advanced Nanomaterials Using Raft Polymerization And Click Reaction, Junting Li

Theses and Dissertations

This research focuses on exploring new synthetic approaches to prepare polymer-based advanced nanomaterials using highly efficient chemical tools, such as reversible addition-fragmentation chain transfer (RAFT) polymerization and click reactions.

In the first project, novel synthetic routes to produce fullerene-based polymers were designed. First, mono-alkynyl functionalized fullerene was prepared starting with pristine fullerene (C₆₀). Methyl methacrylate and 6-azido hexyl methacrylate were then randomly copolymerized via RAFT polymerization with well-controlled molecular weights and copolymer compositions. Finally, the two moieties were covalently assembled into a series of well-defined side-chain fullerene polymers (SFP's) via the copper-catalyzed click reaction. The TGA and UV-vis …

Polybenzimidazole Membranes With Enhanced Mechanical Properties For Extended Lifetime Electrochemical Applications, Max Molleo

Theses and Dissertations

After approximately 20 years of development, polybenzimidazole (PBI) chemistries and the concomitant manufacturing processes have evolved into commercially produced membrane electrode assemblies (MEAs). Commerical PBI MEAs can operate reliably for over two years at elevated temperatures of 120-180°C due to the physical and chemical robustness of PBI membranes. Recently, the Department of Energy has issued a target of 40,000-80,000 hours for stationary (i.e. combined heat and power, back-up power) polymer electrolyte membrane / proton exchange membrane (PEM) fuel cells. It is known through observation that over time, PBI membranes at 180°C creep in a direction perpendicular to compressive forces, thus …

Iridium-Ruthenium/Osmium-Gold Cluster Complexes: Unique Structures And Properties, Qiang Zhang

Theses and Dissertations

Chapter Two

The first Ir-Ru cluster complex was synthesized was the electron-rich, anionic, planar cluster complex [PPN][IrRu6(CO)23], 2.5, (PPN=Bis(triphenylphophoranylidene)-ammonium) which obtained from the reaction of [PPN][IrRu3(CO)13] with one equivalent ruthenium carbonyl (Ru3(CO)12) at 66 oC (THF reflux) for 12h. Compound 2.5 could also be synthesized by using the mono-Iridium compound [PPN][Ir(CO)4] reacts with two equivalent of ruthenium carbonyl. In compound 2.5, all seven metal atoms lie in a plane (max deviation = 0.043(1) Å) with the iridium atom in the center circumscribed by a hexagonal ring of six ruthenium atoms. The anion 2.5 contains 104 valence electrons while both the …

Silylation-Based Kinetic Resolution Of Α-Hydroxy Carbonyl Compounds And Synthesis Of Chiral Isothiourea Catalysts, Yan Zhang

Theses and Dissertations

The thesis describes the silylation-based kinetic resolution for α-hydroxy carbonyl compounds catalyzed by isothiourea catalyst as well as our effort to make novel chiral isothiourea catalyst.

In Chapter 1, general background will be introduced, including chirality, general methods to obtain enantiopure compounds and kinetic resolution. In Chapter 2, the mechanism of the chiral recognition was discussed and a novel isothiourea catalyst was design to investigate the mechanism. The synthesis of the new catalyst was also described in this chapter.

In Chapter 3, the silylation-based kinetic resolution for α-hydroxy carbonyl compounds will be discussed. Since silylation-based kinetic resolution have already been …

Plant Virus Based Materials For Cell Alignment And Differentiation, Elizabeth Balizan

Theses and Dissertations

This research focused on developing and using plant virus based scaffolds to understand substrate control over cell alignment and differentiation. The first part of this work centered on development of virus based patterns that were then used to align and elongate aortic smooth muscle cells (SMCs). Virus patterns were generated in capillary tubes via a simple drying method. Three experimental parameters were used to control pattern formation: (1) protein concentration, (2) salt concentration, and (3) hydrophobicity of the pre-deposition surface. By controlling these parameters several aspects of the final virus patterns were controlled. First, virus orientation was controlled. Patterns were …

A Silylation Based Kinetic Resolution Of Secondary Alcohols And The Synthesis And Structural Characterization Of Pyridyl-Oxazolidine Compounds, Cody Ian Sheppard

Theses and Dissertations

Described herein is the first enantioselective silylation based kinetic resolution of monofunctional secondary alcohols to achieve useful levels of enantioselectivity. Using commercially available reagents, the reaction conditions were optimized and found to successfully resolve several secondary alcohols with high enantioselectivity. It was discovered that the nucleophilic isothiourea compound (-)-tetramisole, with Ph3SiCl as the silyl source, gave superior results to other nucleophilic catalysts and was capable of performing the kinetic resolution in as little as 45 minutes using mild reaction conditions. The structural and electronic characteristics of successful and less successful substrates are also discussed.

Chapter three discusses mechanistic investigations and …

An Analysis Of Constructive Network Formation Models, Gary Fredericks

Theses and Dissertations

We study a family of network formation models to determine how payment rules affect the final network topologies that emerge. In our model a set of nodes starts out without any edges and the nodes must pay for the creation of edges using one of several different payment mechanisms. Example payment mechanisms include one node paying for the whole edge, and the cost being shared equally between the two nodes. We show how the set of networks formed by some payment rules are subsets of those formed by other rules. We also perform extensive empirical tests on networks of up …

Plc Code Vulnerabilities Through Scada Systems, Sidney E. Valentine, Jr.

Theses and Dissertations

Supervisory Control and Data Acquisition (SCADA) systems are widely used in automated manufacturing and in all areas of our nation's infrastructure. Applications range from chemical processes and water treatment facilities to oil and gas production and electric power generation and distribution. Current research on SCADA system security focuses on the primary SCADA components and targets network centric attacks. Security risks via attacks against the peripheral devices such as the Programmable Logic Controllers (PLCs) have not been sufficiently addressed.

Our research results address the need to develop PLC applications that are correct, safe and secure. This research provides an analysis of …

Identifying Values And Benefits Of Congaree National Park, Maka Bitsadze

Theses and Dissertations

Protected areas are important tools for the conservation of biological diversity. They also support a wide range of ecosystem services and provide economic, cultural and social values and benefits. Many values and benefits of protected areas are poorly understood and greatly under-valued by decision-makers, the business sector, and the general public. Accordingly, identification and assessment of values and benefits of protected areas has been increasingly promoted during recent years.

This research investigates values and benefits of Congaree National Park and provides guidance for the further economic valuation of identified values and benefits. While the ecological significance of Congaree National Park …

Who Needs Tablets? We Do, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

What role do tablets play increasingly in our daily lives? Is it possible that they could revolutionize the future of publishing and education?

Logic, Not Evidence, Supports A Change In Expert Testimony Standards: Why Evidentiary Standards Promulgated By The Supreme Court For Scientific Expert Testimony Are Inappropriate And Inefficient When Applied In Patent Infringement Suits, Claire R. Rollor

Journal of Business & Technology Law

No abstract provided.

Planetary Nebula Spectrograph Survey Of S0 Galaxy Kinematics – Ii. Clues To The Origins Of S0 Galaxies, A. Cortesi, M. R. Merrifield, L. Coccato, M. Arnaboldi, O. Gerhard, Aaron J. Romanowsky, N. G. Douglass, K. Kuiijken, M. Capaccioli, K. C. Freeman, K. Saha, A. L. Chies-Santos

Faculty Publications

The stellar kinematics of the spheroids and discs of S0 galaxies contain clues to their formation histories. Unfortunately, it is difficult to disentangle the two components and to recover their stellar kinematics in the faint outer parts of the galaxies using conventional absorption line spectroscopy. This paper therefore presents the stellar kinematics of six S0 galaxies derived from observations of planetary nebulae, obtained using the Planetary Nebula Spectrograph. To separate the kinematics of the two components, we use a maximum-likelihood method that combines the discrete kinematic data with a photometric component decomposition. The results of this analysis reveal that: the …

The Densest Galaxy, J. Strader, A. C. Seth, J. P. Brodie, D. A. Forbes, G. Fabbiano, Aaron J. Romanowsky, C. Conroy, N. Caldwell, V. Pota, C. Usher, J. A. Arnold

Faculty Publications

We report the discovery of a remarkable ultra-compact dwarf galaxy around the massive Virgo elliptical galaxy NGC 4649 (M60), which we call M60-UCD1. With a dynamical mass of 2.0 × 108 M ☉ but a half-light radius of only ~24 pc, M60-UCD1 is more massive than any ultra-compact dwarfs of comparable size, and is arguably the densest galaxy known in the local universe. It has a two-component structure well fit by a sum of Sérsic functions, with an elliptical, compact (rh = 14 pc; n ~ 3.3) inner component and a round, exponential, extended (rh = 49 pc) outer component. …

The Paucity Of Globular Clusters Around The Field Elliptical Ngc 7507, J. P. Caso, T. Richtler, L. P. Bassino, R. Salinas, R. R. Lane, Aaron J. Romanowsky

Faculty Publications

There is strong evidence that globular cluster systems (GCSs) of massive galaxies are largely assembled by infall/accretion processes. Therefore, we expect the GCSs of isolated elliptical galaxies to be poor. Alhough not completely isolated, NGC 7507 is a massive field elliptical galaxy with an apparently very low dark matter content. Aims: We determine the richness, the colour distribution, and the structural properties of the GCS of NGC 7507. Methods: We perform wide-field Washington photometry with data obtained with the MOSAIC II camera at the 4m-Blanco telescope, CTIO. Results: The GCS is very poor with S_N ~ 0.6. We identify three …

Angular Momentum And Galaxy Formation Revisited: Effects Of Variable Mass-To-Light Ratios, S. M. Fall, Aaron J. Romanowsky

Faculty Publications

We rederive the relation between the specific angular momentum j sstarf and the mass M sstarf of the stellar matter in galaxies of different morphological types. This is a revision of the j sstarf-M sstarf diagram presented in our recent comprehensive study of galactic angular momentum. In that work, we estimated j sstarf from kinematic and photometric data that extended to large radii and M sstarf from near-infrared luminosities LK with an assumed universal mass-to-light ratio M sstarf/LK . However, recent stellar population models show large variations in M sstarf/LK correlated with B – V color. In the present work, …

Governing The Post-Socialist Transitional Commons: A Case From Rural China, Shitong Qiao

Faculty Scholarship

When the collective declines, who manages the collective-owned land? When the socialist state fails, who possesses the state-owned river? This Article concerns the governance of land and natural resources that are still owned by collectives or the state in rural China. No effective community governance has evolved in rural China to fill the authority vacuum left by the dissolution of the people’s commune system. As a result, such land and natural resources have become real commons. In describing these I use the term “transitional commons” to indicate both the crucial influence of the transitional political legal environment in their emergence …

Front Matter

The Synapse: Intercollegiate science magazine

No abstract provided.

Winter Term In Belize, Elie Goldberg

The Synapse: Intercollegiate science magazine

No abstract provided.

Female Power & Agency In Animal Behavior, Nicole Le

The Synapse: Intercollegiate science magazine

No abstract provided.

Issue 3

The Synapse: Intercollegiate science magazine

No abstract provided.

Eat Strong: Diet And Nutrition, Helen Rich

The Synapse: Intercollegiate science magazine

No abstract provided.

Sriracha And The Science Of Pain, Weelic Chong

The Synapse: Intercollegiate science magazine

No abstract provided.

Getting Sprung: Biological Underpinnings Of Spring Fever, Cynthia Mckelvey

The Synapse: Intercollegiate science magazine

No abstract provided.

Fantastic Fungi, Zoe Lye

The Synapse: Intercollegiate science magazine

No abstract provided.

Biology’S Obsession With Drosophila Melanogaster: Your Everyday Fruit Fly— Or Is It?, Purba Tyagi

The Synapse: Intercollegiate science magazine

No abstract provided.