Life Sciences Commons^™

Synthesis, Characterization, And Application Of High Surface Area, Mesoporous, Stabilized Anatase Tio2 Catalyst Supports, Rebecca Elizabeth Olsen

Theses and Dissertations

Nanomaterials have attracted substantial attention in the area of catalysis due to the unique properties they exhibit such as high surface areas, intricate pore networks and unique morphologies. TiO2 has attracted attention as a catalyst since the discovery of its high photocatalytic activity by Fuishima and Honda in 1972. Given its high thermal stability, low cost, low environmental impact, and versatility, TiO2 is a widely used commercial catalyst and catalyst support. TiO2 is used in many applications such as photocatalysis is also an excellent support material for noble metals in a number of oxidative synthesis and pollution-control reactions. Though TiO2 …

Nonlinear Spectroscopic Investigation Of Adsorption To C-18 Model Stationary Phase, Anthony D. Peterson

Theses and Dissertations

Reversed-phase liquid chromatography (RPLC) is a commonly used separation technique in chemistry. Nevertheless, the mechanistic interactions at the molecular level among the eluent, analyte, and the stationary phase are not fully understood. Because of this limited understanding, optimization of the separation must be done experimentally. Learning more about molecular interactions should aid in improving separations. We are currently using second-harmonic generation (SHG) spectroscopy to investigate how analytes adsorb to the surface. SHG is a spectroscopic technique that produces signal only at places of non-isotropic symmetry; this typically occurs at surfaces. SHG can be used to produce surface isotherms of test …

Formation And Analysis Of Zinc Oxide Nanoparticles And Zinc Oxide Hexagonal Prisms And Optical Analysis Of Cadmium Selenide Nanoparticles, Jared M. Hancock

Theses and Dissertations

In this dissertation, methods to synthesize ZnO are reported. First, zinc oxide nanoparticles were synthesized with small amounts of transition metal ions to create materials called dilute magnetic semiconductors (DMS). We employed a low temperature sol-gel method that produces ZnO nanoparticles of reproducible size and incorporates cobalt, nickel, and manganese ions into the nanoparticles. Conditions were controlled such that a range of amounts of Co, Ni, and Mn were incorporated. The incorporation was tracked by color changes in the white ZnO powder to blue for Co, green for Ni and yellow for Mn. XRD measurements showed the nanoparticles were on …

Structure And Function Of Proteins Investigated By Crystallographic And Spectroscopic Time-Resolved Methods, Namrta Purwar

Theses and Dissertations

Biomolecules play an essential role in performing the necessary functions for life. The goal of this thesis is to contribute to an understanding of how biological systems work on the molecular level. We used two biological systems, beef liver catalase (BLC) and photoactive yellow protein (PYP). BLC is a metalloprotein that protects living cells from the harmful effects of reactive oxygen species by converting H2O2 into water and oxygen. By binding nitric oxide (NO) to the catalase, a complex was generated that mimics the Cat-H2O2 adduct, a crucial intermediate in the reaction promoted by the catalase. The Cat-NO complex is …

Transcending Microbial Source Tracking Techniques Across Geographic Borders: An Examination Of Human And Animal Microbiomes And The Integration Of Molecular Approaches In Pathogen Surveillance In Brazil And The United States, Amber Mae Koskey

Theses and Dissertations

Waterborne illnesses, attributed to the ingestion or contact with contaminated water, present a significant global health concern. Surface water sources can be impacted by wide array of pollution inputs, but fecal pollution generates the most significant and acute threat to human health. Therefore, the detection of fecal bacteria in surface water sources remains an important public health objective. Current surface water monitoring employs the use of fecal indicator bacteria (FIB) including E. coli and enterococci as proxies for pathogenic organisms carried in fecal pollution. These traditional indicators, detected by culture-based microbiological methods, do not discriminate fecal sources from another. New …

Investigation Into The Effects Of Pegylation On The Thermodynamic Stability Of The Ww Domain, Sam S. Matthews

Theses and Dissertations

The covalent attachment of poly(ethylene glycol) (PEG) to a protein surface (known as PEGylation), has been demonstrated to increase the serum half-life of therapeutic proteins by reducing kidney clearance and immunogenicity and by protecting against proteolysis. Theses beneficial effects could be further enhanced if PEGylation consistently increased protein conformational stability (i.e. the difference in free energy between the folded and unfolded states). However, the effects of PEGylation on protein conformational stability are unpredictable; PEGylation has been reported to increase, decrease, or have no effect on the conformational stability of medicinal proteins.This thesis details the results of two studies aimed at …

Ferritin-Based Photo-Oxidation Of Biomass For Nanoparticle Synthesis, Bioremediation, And Hydrogen Evolution, Oscar Petrucci

Theses and Dissertations

The cell is the basic unit of all living organisms. It is an amazing machine capable of self-replicating, growing, and synthesizing and shuttling thousands of compounds. To perform all of these activities the cell needs energy. The original source of energy for all living beings is the Sun. The energy of the sun is collected by the autotrophs (mostly plants) through photosynthesis and stored in the chemical bonds of carbohydrates and lipids through carboxylic acid intermediates; animals use these compounds to obtain the energy for their cells. Most of the energy extracted by the cell comes from the citric acid …

Phylogeographic Inference Of Insular Mule Deer (Odocoileus Hemionus) Divergence In North America's Desert Southwest, Ona Alminas

Theses and Dissertations

Though mule deer (Odocoileus hemionus) persist in robust populations throughout most of their North American distribution, nearly 60% of their historic range in México has declined due to habitat loss and unregulated hunting. Two of the six subspecies inhabiting México's deserts and Baja California peninsula are of conservation concern, occurring on land bridge islands in the Pacific Ocean (O. h. cerrosensis on Cedros Island: threatened) and in the Sea of Cortés (O. h. sheldoni on Tiburón Island: endangered). Focusing on the desert southwest (n=449 deer), we obtained 1,611 bp of mtDNA sequence (control region: 583 bp; cytochrome b gene: 1,028 …

Protein Association In Living Cells Using Fret Spectrometry: Application To G-Protein Coupled Receptors, Suparna Patowary

Theses and Dissertations

Recent advancements in fluorescence microscopy coupled with newly developed fluorescent tags have transformed Fluorescence (Förster) Resonance Energy Transfer (FRET) into a powerful tool studying in vivo molecular interactions with improved spatial (angstrom) resolution. Though widely used to study protein-protein interactions, generalizing and testing the FRET theory for oligomeric complexes containing multiple donors and acceptors has only become possible in recent years. Therefore, many aspects of it are yet unexplored.

In this work, we tested the kinetic theory of FRET using linked fluorescent proteins located in the cytoplasm or at the plasma membrane. We used a novel method developed in our …

Evaluation Of Vdr-Coactivator Inhibitors Using Biochemical And Cell-Based Assays, Athena Marie Baranowski

Theses and Dissertations

ABSTRACT

EVALUATION OF VDR–COACTIVATOR INHIBITORS USING BIOCHEMICAL AND CELL–BASED ASSAYS

by

Athena Baranowski

The University of Wisconsin–Milwaukee, 2013

Under the Supervision of Dr. Alexander Arnold

The vitamin D receptor (VDR) is a ligand–dependent transcription factor, which belongs to the nuclear receptor superfamily. VDR–mediated gene regulation is governed by coregulators (coactivators and corepressors). VDR coregulator binding inhibitors (CBIs), which were discovered using high throughput screening (HTS), were evaluated using cell–based assays and biochemical assays to determine their ability to inhibit the interaction between VDR and steroid receptor coactivator–2 (SRC–2). Determining their ability to inhibit the VDR–SRC–2 interaction can lead to the …

Obstacles And Solutions To Studying Functional Adhesives Using Vibrational Sum-Frequency Generation Spectroscopy, Angela Renee Andersen

Theses and Dissertations

Important aspects of adhesion occur at interfaces, including structures that may be different from those in the bulk materials. However, probing the orientation of molecules in functional adhesives poses a significant challenge because adhesive molecules are always located at a buried interface. The limited penetration depth of surface-specific analysis prohibits the study of buried interfaces using those techniques. The large quantity of bulk molecules relative to the adhesive molecules interacting at the interface results in the bulk signal swamping out adhesive signal in bulk analysis techniques. An interface-specific technique is required to study functional adhesives. One such technique that has …

Improving The Efficiency Of Fall Applied N With Cover Crops, Corey Lacey

Theses and Dissertations

Nitrate loss studies in Midwestern tile-drained fields have found that fall applied nitrogen (N) resulted in elevated nitrate concentrations in tile water during both the corn and soybean year of a 2 year rotation. The effectiveness of cover crops to reduce nitrate leaching when N is spring applied has been well demonstrated, however there is a dearth of knowledge on the ability of cover crops to reduce nitrate leaching in a system where N is fall applied. Thus, the objectives of this research were to (i) investigate the efficacy of winter cover crops to reduce nitrate leaching from fall applied …

Size-Based Separation Of Bioparticles Using Planar Nanofluidic Devices, Jie Xuan

Theses and Dissertations

Nanofluidic devices are structures having at least one dimension in the submicron range, which is of the same order of magnitude as the sizes of biomolecules and bioparticles such as proteins and viruses. As a result, size-selective separations are important applications for nanofluidics. Well-defined micro or nano device structures fabricated via micromachining have greatly reduced sample consumption and enabled separations in a parallel fashion, promising significant speed and resolution advantages over conventional size separation techniques, such as gel electrophoresis and size exclusion chromatography. In collaboration with others, I have developed a size separation method using nanofluidic devices consisting of an …

Formation, Functionalization, Characterization, And Applications Of A Mixed-Mode, Carbon/Diamond-Based, Core-Shell Phase For High Performance Liquid Chromatography, Landon A. Wiest

Theses and Dissertations

My work has focused on a variety of different types of diamond-based, core-shell particles. These particles are formed with inert cores and poly(allylamine)/nanodiamond shells. Their intended purpose is to form an LC stationary phase that is stable from pH 1 – 14 and at elevated temperatures. At the beginning of my studies, the particles that had been made in the Linford laboratory were pH stable, but irregular and had poor mechanical stability. Since that time, I have worked to improve the particles by using more spherical zirconia and carbon cores, and I have improved their mechanical stability via chemical crosslinking …

Self-Assembled Dna Origami Templates For The Fabrication Of Electronic Nanostructures, Elisabeth Pound Gates

Theses and Dissertations

An important goal of nanoscience is the self-assembly of nanoscale building blocks into complex nanostructures. DNA is an important and versatile building block for nanostructures because of its small size, predictable base pairing, and numerous sequence possibilities. I use DNA origami to design and fold DNA into predesigned shapes, to assemble thin, branched DNA nanostructures as templates for nanoscale metal features. Using a PCR-based scaffold strand generation procedure, several wire-like nanostructures with varying scaffold lengths were assembled. In addition, more complex prototype circuit element structures were designed and assembled, demonstrating the utility of this technique in creating complex templates. My …

Mathematical Modeling Of Physiological Characteristics In Female Soccer Athletes, Thomas S. Goeppinger

Theses and Dissertations

Intermittent sports create challenges regarding performance measurement. Quantification of various physiological characteristics can lead to increased performance and injury reduction throughout a season of competition. Currently, a variation of an athletes' heart rate is the primary physiological characteristic used for quantifying load on the athlete. With increasing technology, we have the ability to gather additional characteristics regarding the physicality of athletes during competition. This study statistically compares various models using these new characteristics as predictors to the athletes' lactate concentration in their blood. From this comparison, we determine which physiological characteristic(s) best represent the performance and fatigue of these athletes. …

Zinc Chemical Biology: The Pursuit Of The Intracellular Targets Of Zinquin, Andrew Nowakowski

Theses and Dissertations

Fluorescent sensors have been a main microscopic tools used to understand Zn2+ physiology on a cellular level. The use of the fluorescent Zn2+ sensor Zinquin (ZQ) and its analogues have revealed that transient Zn2+ is a chief component in a variety of biochemical pathways. Yet, little work has been performed to validate the exact targets of Zinquin in a cellular environment. The goals of this investigation are to determine the types of Zinquin reactions that take place in the cell as well as the identities of its cellular targets.

It has been hypothesized that Zinquin reacts with free Zn2+ within …

Phytoplankton Life History Events: Resting Stages And Physiological Cell Death, Christine R. Kozik

Theses and Dissertations

Understanding and predicting changes in phytoplankton populations requires knowledge of key life history processes such as recruitment from benthic resting stages and losses due to sedimentation and cell death. Currently, these processes are poorly understood in freshwater systems. Phytoplankton resting stage and cell death life history events were separately examined in two freshwater systems in Wisconsin, four northern lakes and an urban pond. In the norther lakes, sedimentation and benthic recruitment were examined using sediment and recruitment traps that were sampled weekly over two summers. Sedimentation and benthic recruitment contributed little to changes in standing crop chl a, but rather …

Studies Toward The Synthesis Of Lyconadin A And Cranomycin, Brad M. Loertscher

Theses and Dissertations

Lyconadin A is a pentacyclic Lycopodium alkaloid isolated from the club moss Lycopodium companatum with anticancer activity. Our approach sought to incorporate a 7-exo–6-exo acyl radical cyclization cascade to access the bicyclo[5.4.0]undecane framework of lyconadin A. Our studies created methodology for the synthesis of 5-alkyl and 3,5-dialkyl-6-carbomethoxy-2-pyridones and sterically demanding epoxide substrates. These epoxide substrates underwent an unanticipated Payne rearrangement.Cranomycin is a potent antibiotic with antiprotozoal activity. Structurally it is a cyclopentane ring system with substitution at each carbon in the ring. Another interesting structural aspect is the existence of three contiguous quaternary stereocenters including two tertiary alcohols and a …

Developmental Signaling Requires Inwardly Rectifying K+ Channels In Drosophila Melanogaster, Giri Raj Dahal

Theses and Dissertations

Inwardly rectifying potassium (IRK/Kir) channels regulate intracellular K+ concentrations and membrane potential. Disruption of Kir2.1 causes dominantly inherited Andersen Tawil Syndrome (ATS). ATS patients suffer from cardiac arrhythmias, periodic paralysis, and cognitive impairment. These symptoms are consistent with current understanding of the role of ion channels in muscle cells and neurons. However, ATS symptoms also include craniofacial and digital deformities such as cleft palate, dental defects, wide set eyes, low set ears, and crooked or fused digits. These developmental defects were not consistent with current understanding of developmental signaling or previously described roles for ion channels. We found that phenotypes …

The Role Of Smpb In Licensing Tmrna Entry Into Stalled Ribosomes, Mickey R. Miller

Theses and Dissertations

Ribosomes translate the genetic information contained in mRNAs into protein by linking together amino acids with the help of aminoacyl-tRNAs. In bacteria, protein synthesis stalls when the ribosome reaches the 3'-end of truncated mRNA transcripts lacking a stop codon. Trans-translation is a conserved bacterial quality control process that rescues stalled ribosomes. Transfer-messenger RNA (tmRNA) and its protein partner SmpB mimic a tRNA by entering the A site of the ribosome and accepting the growing peptide chain. The ribosome releases the truncated mRNA and resumes translation on the tmRNA template. The open reading frame found on tmRNA encodes a peptide tag …

Investigation Of Water-Molecule Complexes And Their Catalytic Effect On Important Atmospheric Reactions, Taylor Scott Cline

Theses and Dissertations

This dissertation is a collection of works that investigates issues related to environmental chemistry. The first portion of this research explores the role of water vapor on the kinetics of important atmospheric reactions. Work is presented on the self-reaction of β-hydroxyethyl peroxy radical (β-HEP) and the catalytic increase in reaction rate by water vapor. β-HEP serves as a model system for investigating the possible role of water vapor in perturbing the kinetics and product branching ratio of atmospheric reactions of other alkyl peroxy radicals. The self-reaction rate coefficient of β-HEP was investigated between 276-296 K with 1.0 × 10^15 to …

Miniaturized Electrostatic Ion Beam Trap Mass Analyzer, Junting Wang

Theses and Dissertations

The electrostatic ion beam trap (EIBT) was designed by D. Zajfman during the previous decade. This ion trap combines many properties of the Fourier-transform ion cyclotron resonance (FTICR) mass analyzer and time-of-flight (TOF) mass analyzer. There are several advantages for the electrostatic ion beam trap. First, large mass-to-charge particles in an electrostatic field could be easier to analyze. Second, there is a folded flight path, which could make the mass analyzer smaller compared to conventional TOF mass analyzer. This principle of operation of this ion trap is analogous to an optical resonator. The ions are trapped in a voltage valley …

Identification And Differentiation Of Tier 1 Bacterial Agents Using Gas Chromatography-Mass Spectrometry, Dan Li

Theses and Dissertations

A simple method was developed for detection and differentiation of five Tier 1 bacterial agents, including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia pseudomallei and Burkholderia mallei as well as their closely related near neighbors by gas chromatography-mass spectrometry (GC-MS). Generally, different classes of compounds can be used as biomarkers for biowarfare agent detection, including nucleic acids (i.e., DNA or RNA), proteins (i.e., antibodies), carbohydrates (i.e., sugars), lipopolysaccharides, lipids (i.e., fatty acids) and small molecules. One-step thermochemolysis (TCM) was developed to provide GC-MS detectable biomarker signatures, including sugars, fatty acids and small molecules. Solid phase micro-extraction (SPME) was used for …

Bacterial Spores Remain Viable After Electrospray Charging And Desolvation, Sara Nielson Pratt

Theses and Dissertations

The electrospray survivability of B. subtilis spores and E. coli was tested in atmospheric mobility experiments. E. coli did not survive electrospray charging and desolvation, but B. subtilis did. Experimental conditions ensured that any surviving bacteria were charged, desolvated, and de-agglomerated. B. subtilis was also found to survive both positive and negative electrospray and subsequent introduction into vacuum conditions. Attempts were made to measure the charge distribution of viable B. subtilis spores using electrostatic deflection. From those experiments, it was found that either the spores do not become highly charged under the electrospray conditions used or only spores in a …

Isolation, Characterization And Synthesis Of Asthma Inducing Fungal Glycolipid And Analytical Method Development For Novel Antimicrobial Peptide Mimics, Vinod Chaudhary

Theses and Dissertations

NKT cells are an important part of human immune system and recognize a specific set of antigens called glycolipids. Only a handful of "natural" NKT cell antigens are known till date. Although NKT cells play a protective role against pathogenic organisms, imbalances in NKT cell functions are implicated in many diseases including asthma. Allergic asthma, a Th2 driven inflammation of airways, is primarily caused by inhalation of environmental allergens. In the last decade, inhaled allergen Aspergillus fumigatus has been under scrutiny for the presence of NKT cell antigens that might trigger asthma. We successfully isolated, characterized and synthesized a "natural" …

Synthesis And Immunological Evaluation Of Type I, Type Ii, And Gamma Delta Nkt Cell Antigens, Brian L. Anderson

Theses and Dissertations

The purpose of the immune system is to protect our bodies from infection. One way it accomplishes this task is through the presentation of foreign pathogens to NKT cells. After an antigen is presented to the T cell receptor, activated NKT cells quickly release soluble chemical signals, termed chemokines and cytokines, that modulate the response of the immune system. Due to the immunological relevance of NKT cell activation, we developed and synthesised non-natural analogs of immunostimulatory type I, II, and gamma delta NKT cell antigens. The immunological evaluations of these analogs resulted in identification of sulfatide as a gamma delta …

Nearshore Benthic Oxygen Dynamics In Lake Michigan, Emily H. Tyner

Theses and Dissertations

The intense colonization of the Laurentian Great Lakes by dreissenid mussels has profoundly changed ecosystem processes, particularly benthic oxygen dynamics. Dissolved oxygen concentrations in mussel beds, sloughed Cladophora mats, and sediment indicate that hypoxia forms and disappears in some substrata (ephemeral Cladophora mats), while occurring consistently in others (depositional areas of sloughed Cladophora). Dissolved organic carbon concentrations are high (mean: 143 ± ± 28 ppm) in depositional Cladophora mats but lower (˂ 10 ppm) in most other environments. Field sampling and laboratory experiments suggest that under conditions of low water velocity and thick Cladophora cover, hypoxia may develop atop …

High-Throughput Approaches For The Assessment Of Factors Influencing Bioavailability Of Small Molecules In Pre-Clinical Drug Development, Megan Marie Mccallum

Theses and Dissertations

A bioactive molecule must pass many hurdles to be designated as a "good" pharmaceutical lead or hit compound. It should have a significant activity, selectivity, bioavailability, and metabolic half-life. Many factors have been identified that influence the free drug concentration or bioavailability of orally administered drugs in the earliest development stages. In vitro pre-clinical assays have been developed to measure these parameters. The small molecule properties that are investigated here include aqueous solubility, permeability, reactivity (electrophilicity), small molecule-protein binding, and displacement of protein-bound molecules (drug-drug interactions). The development of rapid and miniaturized assays to quantify these factors is presented herein. …

The Shifting Importance Of Competition And Facilitation Along Diversity, Environmental Severity, And Plant Ontogenetic Gradients, Alexandra Wright

Theses and Dissertations

Ecological theory and empirical studies have focused heavily on the importance of competition in plant communities. Competition can help explain species coexistence, the maintenance of species diversity, and biological invasions. Competition for resources appears to be ubiquitous among coexisting organisms. This overwhelming focus on competition over the past one hundred years may have overshadowed the importance of positive interactions (facilitation). Growing near your neighbors involves competition for resources, but it also involves alteration of a shared microclimate. Neighboring plants have the capacity to increase shade, decrease air temperatures, increase humidity, and increase shallow soil moisture in their local environment. In …