Digital Commons Network^™

Ground Beetle Community Structure And Function In Restored Tallgrass Prairie, Melissa Nelson

Graduate Research Theses & Dissertations

With the removal and destruction of natural areas for human use, there is a push to restore natural habitats. However, most restoration activities focus on reestablishing plant communities, while less is known about the recovery of organisms in higher trophic levels and their functional roles. Considering functional traits (those that explain an organisms’ response to environmental change and impacts on ecosystems) of restored communities may reveal how communities, and the ecosystem functions they drive, recover. Of particular interest are ground beetles (Coleoptera: Carabidae) because of their diversity and important ecological roles as consumers. This study focused on the ground beetle …

Microbiome And Metagenome Of An Anthropogenic Hyperalkaline Slag-Fill Waterway In South Chicago, Illinois, Usa, Jan Ingemar Ohlsson

Graduate Research Theses & Dissertations

The aquifers and waterways around the Lake Calumet area of south Chicago, IL, USA have been affected by a century of intensive industrial waste dumping. Steel slag in particular was used as infilling to claim most of the Calumet Wetlands for industrial and residential development. Since the prohibition and cessation of these disposal activities, a growing body of research has recorded the environmental and health effects of the infill, particularly where interactions between slag minerals and rainwater produces extremely alkaline groundwater (pH ≥13). Atmospheric carbon dioxide interacting with these calcium hydroxide-rich slag fluids produces massive precipitation of a loose, white …

Computational Methods For Bicubic L1 Splines, Priyesh Koyu Rai

Graduate Research Theses & Dissertations

The past two decades have seen the development of L1 splines for interpolation and approximation of geometric data. L1 splines have been shown to preserve shapes better than the conventional L2 splines, especially for data with abrupt changes in the magnitude of spacing. Efficient computation plays an important role in the practical application of L1 splines. This thesis creates new computational methods for constructing bicubic L1 interpolating splines and bicubic L1 spline fits. The bicubic splines in this study are piecewise bicubic polynomials defined on a rectangular grid generated by the tensor product of nodes. We developed a hybrid computational …

Seabird Threats On Land And At Sea: Measuring Nearshore Response To Invasive Predator Eradications And Storm Petrel Diet Response To Fishing Expansion, Lyndsay L. Rankin

Graduate Research Theses & Dissertations

Seabirds are crucial components of many marine and island ecosystems, and yet they are the world’s most threatened group of birds. They spend most of their lives at sea, where they face numerous threats including climate change, pollution, and fisheries. When they return to land to breed, they are threatened by human disturbance and invasive species. This research examines seabird response to threats on land and at sea using stable isotope analysis. Seabirds provide multiple ecosystem services, such as depositing rich marine-derived nutrients into the islands where they nest. Invasive predators disrupt this bottom-up control by decimating seabird populations. Successful …

A Child Shall Lead Them: Exploring Discourses Of Efficacy And Climate Change As They Appear In Children's Animated Film, Jason Derry

Electronic Theses and Dissertations

Recent climate change discourse has tended to presume scientific knowledge and rational argumentation as the principle factor in convincing peoples and publics toward climate action. However, scholarship across numerous fields reveals myriad other contributing factors in how people think about and respond to this environmental crisis, which leans predominately toward silence and apathy. Alongside this, children are often centered as inheriting a calamity, yet find themselves largely disempowered. From out of this rhetorical milieu I interject by way of a multidisciplinary grounding to examine the predominate framings of efficacy in the context of children, climate change, and environmental discourse. To …

Biomass-Derived Activated Carbons For Electrical Double Layer Supercapacitors: Performance And Stress Effect, Wenxin Cao

Theses and Dissertations--Chemical and Materials Engineering

The vigorous development of human civilization has significantly increased the energy consumption in recent years. There is a great need to use renewable energy sources to substitute the depleting traditional fossil fuels, such as crude oil, natural gas and coal. The development of low-cost and high-performance energy storage devices (ESDs) and systems have drawn great attention due to their feasibility as backup power supply and their applications in portable electronics and electric vehicles. Supercapacitors are among the most important ESDs because of their long charging-discharging cycle life, high power capability and a large operating temperature range. In this thesis, high-performance …

Towards The Rational Design And Application Of Polymers For Gene Therapy: Internalization And Intracellular Fate, Landon Alexander Mott

Theses and Dissertations--Chemical and Materials Engineering

Gene therapy is an approach for the treatment of acquired cancers, infectious disease, degenerative disease, and inherited genetic indications. Developments in the fields of immunotherapies and CRISPR/Cas9 genome editing are revitalizing the efforts to move gene therapy to the forefront of modern medicine. However, slow progress and poor clinical outcomes have plagued the field due to regulatory and safety concerns associated with the flagship delivery vector, the recombinant virus. Immunogenicity and poor transduction in certain cell types severely limits the utility of viruses as a delivery agent of nucleic acids. As a result, significant efforts are being made to develop …

Development Of Novel Temperature Responsive Polymeric Sorbents And Their Applications In Water Remediation, Shuo Tang

Theses and Dissertations--Chemical and Materials Engineering

Water remediation utilizing sorption has found strong interest due to its inexpensiveness, universal nature and ease of operation. In particular, thermo-responsive sorbents consisting of N-isopropylacrylamide (NIPAAm) offer significant potential as “smart” and advanced materials to remove multiple aqueous pollutants. NIPAAm exhibits excellent thermo-responsiveness, which senses the external temperature variation and changes its swelling and sorption behaviors in a sharp and rapid manner. At the beginning of this work, an extensive review of literature has been compiled to provide a summary of NIPAAm-based thermo-responsive sorbents in water/wastewater remediation applications.

Initially, we developed a novel approach to synthesize and characterize NIPAAm copolymeric …

Functionalization Of Iron Oxide Nanoparticles And The Impact On Surface Reactive Oxygen Species Generation For Potential Biomedical And Environmental Applications, Trang Mai

Theses and Dissertations--Chemical and Materials Engineering

Iron oxide nanoparticles (IONPs) have been widely studied for a variety of applications, from biomedical applications (e.g., cell separation, drug delivery, contrast agent for magnetic resonance imaging and magnetically mediated energy delivery for cancer treatment) to environmental remediations (e.g., heavy metal removal and organic pollutants degradation). It has been demonstrated that IONPs can induce the production of reactive oxygen species (ROS) via Fenton/Haber-Weiss reactions which has been shown to be one of the key underlying mechanisms of nanoparticles toxicity. This inherent toxicity of nanoparticles has been shown to enhance the efficacy of traditional cancer therapies such as chemotherapy and radiation. …

Cell Surface Coatings For Mammalian Cell-Based Therapeutic Delivery, Pei-Jung Wu

Theses and Dissertations--Chemical and Materials Engineering

The cell plasma membrane is an interactive interface playing an important role in regulating cell-to-cell, cell-to-tissue contact, and cell-to-environment responses. This environment-responsive phospholipid layer consisting of multiple dynamically balanced macromolecules, such as membrane proteins, carbohydrate and lipids, is regarded as a promising platform for various surface engineering strategies. Through different chemical modification routes, we are able to incorporate various artificial materials into the cell surface for biomedical applications in small molecule and cellular therapeutics.

In this dissertation, we establish two different cell coating techniques for applications of cell-mediated drug delivery and the localization of cell-based therapies to specific tissues. The …

Impact Of Conformational Change, Solvation Environment, And Post-Translational Modification On Desulfurization Enzyme 2'-Hydroxybiphenyl-2-Sulfinate Desulfinase (Dszb) Stability And Activity, Landon C. Mills

Theses and Dissertations--Chemical and Materials Engineering

Naturally occurring enzymatic pathways enable highly specific, rapid thiophenic sulfur cleavage occurring at ambient temperature and pressure, which may be harnessed for the desulfurization of petroleum-based fuel. One pathway found in bacteria is a four-step catabolic pathway (the 4S pathway) converting dibenzothiophene (DBT), a common crude oil contaminant, into 2-hydroxybiphenyl (HBP) without disrupting the carbon-carbon bonds. 2’-Hydroxybiphenyl-2-sulfinate desulfinase (DszB), the rate-limiting enzyme in the enzyme cascade, is capable of selectively cleaving carbon-sulfur bonds. Accordingly, understanding the molecular mechanisms of DszB activity may enable development of the cascade as industrial biotechnology. Based on crystallographic evidence, we hypothesized that DszB …

Targeted Illumination Strategies For Hydrogen Production From Purple Non-Sulfur Bacteria, John D. Craven

Theses and Dissertations--Chemical and Materials Engineering

The movement towards a more sustainable energy economy may require not only the generation of cleaner fuel sources, but the conversion of waste streams into value-added products. Phototrophic purple non-sulfur bacteria are capable of metabolizing VFAs (volatile fatty acids)and generate hydrogen as a byproduct of nitrogen fixation using energy absorbed from light. VFAs are easily produced from dark anaerobic fermentation of food, agricultural, and municipal wastes, which could then be fed into photobioreactors of purple bacteria for hydrogen production.

The process of photofermentation by purple bacteria for hydrogen production remains attractive due to the capability of reaching high substrate conversions …

Development Of Magnetic Nanocomposite Materials As Reusable Adsorbents For Chlorinated Organics In Contaminated Water, Angela Gutierrez

Theses and Dissertations--Chemical and Materials Engineering

The constant growth in population worldwide over the past decades continues to put forward the need to provide access to safe, clean water to meet human needs. There is a need for cost-effective technologies for water and wastewater treatment that can meet the global demands and the rigorous water quality standards and at the same maximizing pollutant efficiency removal. Current remediation technologies have failed in keeping up with these factors without becoming cost-prohibitive. Nanotechnology has recently been sought as a promising option to achieve these goals. The use of iron oxide magnetic nanoparticles as nanoadsorbents has led to a new …

Nanoharvesting And Delivery Of Bioactive Materials Using Engineered Silica Nanoparticles, Md Arif Khan

Theses and Dissertations--Chemical and Materials Engineering

Mesoporous silica nanoparticles (MSNPs) possess large surface areas and ample pore space that can be readily modified with specific functional groups for targeted binding of bioactive materials to be transported through cellular barriers. Engineered silica nanoparticles (ESNP) have been used extensively to deliver bio-active materials to target intracellular sites, including as non-viral vectors for nucleic acid (DNA/RNA) delivery such as for siRNA induced interference. The reverse process guided by the same principles is called “nanoharvesting”, where valuable biomolecules are carried out and separated from living and functioning organisms using nano-carriers. This dissertation focuses on ESNP design principles for both applications. …

The Fabrication And Characterization Of Metal Oxide Nanoparticles Employed In Environmental Toxicity And Polymeric Nanocomposite Applications, Matthew Logan Hancock

Theses and Dissertations--Chemical and Materials Engineering

Ceria (cerium oxide) nanomaterials, or nanoceria, have commercial catalysis and energy storage applications. The cerium atoms on the surface of nanoceria can store or release oxygen, cycling between Ce³⁺ and Ce⁴⁺, and can therefore act as a therapeutic to relieve oxidative stress within living systems. Nanoceria dissolution is present in acidic environments in vivo. In order to accurately define the fate of nanoceria in vivo, nanoceria dissolution or stabilization is observed in vitro using acidic aqueous environments.

Nanoceria stabilization is a known problem even during its synthesis; in fact, a carboxylic acid, citric acid, is …

Oleic Acid Vesicles: Formation, Mechanisms Of Reactivity, And Uses In Determination Of Terpene Activity, Laura A. Walther

Theses and Dissertations--Chemistry

This dissertation will focus on the volatile compounds released upon the burning of incense which are numerous and varied. The first part of this dissertation is the gas chromatography-mass spectral (GC-MS) analysis of burning incense collected via solid phase microextraction (SPME) with the aim of developing a library of compounds found in incense as used in the Orthodox church.

The second part of this dissertation has the aim of developing a method for forming oleic acid bilayer vesicle membranes and a fluorescence spectroscopy method by which the reactivities of these vesicles can be analyzed. These reactivities include permeability, fluidity, aggregation, …

Illuminating Dna Packaging In Sperm Chromatin: How Polycation Lengths, Underprotamination And Disulfide Linkages Alters Dna Condensation And Stability, Daniel Kirchhoff

Theses and Dissertations--Chemistry

During spermiogenesis, somatic chromatin is remodeled and a vast majority (> 90%) of DNA histones are replaced by short arginine-rich peptides called protamines. This compaction is immense, with protamine-DNA self-assembly in sperm chromatin resulting in a final volume roughly 1/6th of a somatic nucleus. This near crystalline organization of the DNA in sperm is thought crucial both for the transport of the paternal genes as well as for the protection of genetic information as sperm chromatin is transcriptionally inactive and all DNA repair mechanisms are shut down.

Chapter 1 will include an overview of the topics discussed in this document, …

Modeling The Condensed-Phase Behavior Of Π-Conjugated Polymers, Walker Mask

Theses and Dissertations--Chemistry

It is well established that the morphology and physical properties of an organic semiconducting (OSC) material regulate its electronic properties. However, structure-function relationships remain difficult to describe in polymer-based OSC, which are of particular interest due to their robust mechanical properties. If relationships among the molecular and bulk levels of structure can be found, they can aid in the design of improved materials. To explore and detail important structure-function relationships in polymer-based OSC, this work employs molecular dynamics (MD) simulations to study various π-conjugated polymers in different environments. Two independent investigations are discussed in this work. One investigation examines how …

Detection Of Beta-Lactamase Variants In Municipal Wastewater And Fresh Water, Sunil Pandey

Masters Theses

The occurrence and spread of antibiotic-resistant genes (ARGs) are pressing public health problems worldwide. A key factor contributing to the spread of ARGs is lateral gene transfer. Wastewater treatment plants (WWTPs) are measured hot spots of microbial diversity and resistance because they receive polluted wastewater from diverse sources and contain a variety of different environments with dense bacterial loads. Due to the overuse of antibiotics the genetic capacities of microbes have profited. This helps every source of resistance gene and every means of horizontal gene transmission to develop the multiple mechanism of resistance to each antibiotic used clinically, agriculturally, or …

Support From Above The Glass Ceiling: Narratives Of Women As University Student Leaders, Rebecca Schwartz

Masters Theses

Using qualitative methodology. the researcher examined motivations, social support networks, and challenges college women face in student leadership positions. Four semi-structured interviews were conducted at a midsized university in the Midwest with college women in various positions of organizational leadership. The researcher identified motivational factors for women to apply for leadership positions as well as described the social support network that exists for college women in positions of leadership. Challenges college women face in achieving higher leadership positions were also identified. Lastly, recommendations were made for student affairs professionals and women in leadership based on the research findings.

College Students Experiences Participating In International Alternative Break Trips, Dayton L. Ehrlich

Masters Theses

This study sought to explore undergraduate students’ experiences participating in international alternative break trips. A qualitative approach was used to understand the motivating factors as well as the impact the trip had on them. Participants included three female undergraduate students who had participated in an international alternative break trip in Mexico were interviewed one-on-one. The results demonstrated there were multiple different motivating factors and impacts the students experienced. The motivating factors consisted of student involvement, they were all personally invited on the trip, practicing a new language, opportunity to leave the country, and service was not a motivator. The impacts …

Construct Validity Of The Teate Depression Inventory (Tdi) With A Middle Eastern/Arab American Sample, Dalia Bunni

Masters Theses

The purpose of the study was to examine the construct validity of a newer test used to measure depressive symptoms, the Teate Depression Inventory (TDI). The primary focus of the study was on Middle Eastern/Arab Americans (ME/AA). Previous research has demonstrated that ethnic minority groups may experience and present internalizing disorders, such as depression and anxiety differently than the majority ethnic group, White/Caucasian (W/C) individuals. Further, research suggests that there is a disparity in mental health care among ethnic minority groups, starting with detecting and diagnosing mental health disorders. Inaccurate detection and diagnoses informs inaccurate treatment, further creating a disparity. …

A Pipeline For Exogenous Gene Expression And Biomass Analysis In Plants, Bijay Bisunke

Masters Theses

Biological pretreatment of biomass is typically required for the production of liquid biofuels, which are viable alternatives to traditional fossil fuels. While traditional thermomechanical pretreatments are effective at helping to deconstruct lignocellulose, they are often expensive and tend to generate environmentally dangerous waste materials. An alternative to traditional pretreatment strategies is biological pretreatment, which has focused on lignocellulose-degrading organisms, such as white-rot fungi. While direct pretreatment of biomass with white-rot fungi has shown great promise, directly expressing functional white-rot fungi genes in plants (i.e. in planta expression) has the potential to be even more efficient because the biomass itself …

Study Of Genetic Regulators That Control Development And Secondary Metabolism In The Genus Aspergillus, Timothy Satterlee

Graduate Research Theses & Dissertations

In this study, I investigated the role of two different regulatory genes in two different species of pathogenic fungi from the genus Aspergillus. The first study involves a transcriptome analysis of the epigenetic regulator rmtA in the plant pathogen Aspergillus flavus. A. flavus colonizes numerous oil seed crops such as corn, peanuts, treenuts and cotton worldwide, contaminating them with aflatoxins and other harmful potent toxins. Previously our lab characterized the gene rmtA, which encodes an arginine methyltransferase in A. flavus, and demonstrated its role as regulator of the expression of the aflatoxin gene cluster and concomitant synthesis of toxin. Furthermore, …

Functions Of Dfrp And Other Drg Pathway Genes In The Moss Physcomitrella Patens, Robert James Srygler

Graduate Research Theses & Dissertations

GTP binding proteins (G proteins) are molecular switches that regulate many aspects of physiology in all cells. DRG1 and DRG2 (Developmentally Regulated GTP-binding proteins) have been found in all eukaryotes examined. Amino acid identity across eukaryotes is about 65% within an orthologous group and 55% between paralogs of a single species. Although DRGs are likely involved in some aspect of translation regulation, details of their precise cellular functions are not known.

In addition to DRGs there are other genes/proteins that comprise the “DRG pathway.” DFRPs (DRG Family Regulatory Proteins) have been shown to physically and genetically interact with DRGs. Previous …

Development Of Synthetic Methodologies Of Nucleophile-Electrophile Chemistry, Michael R. Stentzel

Graduate Research Theses & Dissertations

The work outlined in this dissertation describes the development of synthetic methodologies utilizing a wide electrophilicity range of substrates towards the synthesis of new compounds. Substitution, addition, and superelectrophilic chemistry are powerful tools to afford potentially important compounds. These concepts are summarized in chapter 1.

Chapter 2 describes the capture of superacid catalyzed fluorenyl cations with nitriles (Ritter reaction) and alcohols. Optimization of reaction conditions and extensive scope studies were performed.

In chapter 3, the Michael addition of organometallic reagents with N-heterocyclic substituted olefins is explored. The nucleophilic carbanion intermediate species is shown to have reactivity towards strong electrophiles. With …

The Design, Synthesis, And Evaluation Of Inhibitors Of The Ispf Enzyme In The Mep Pathway, Christopher G. Stewart

Graduate Research Theses & Dissertations

Isoprenoids are a class of over 50,000 compounds that serve as key precursors for many compounds in plants and animals. These compounds play critical roles in many biological functions such as cellular growth, respiration, and go on to form critical compounds such as steroids and vitamins. Despite their overall necessity to life their biosynthesis only follows two synthetic pathways. These pathways are the Mevalonic Acid (MVA) Pathway and the 2-C-Methyl-D-Erythritol-4-Phosphate (MEP) Pathway also known as the non-mevalonate pathway. The MVA pathway is found primarily in humans and some higher plants while the MEP pathway is found in bacteria and some …

Why Do Symbiodinium Migrate? Evolutionary Conflict In A Host-Symbiont Community, Jacey Lynn Strohecker

Graduate Research Theses & Dissertations

Climate change is an increasing problem for species all around the globe, including coral reef communities, which are among the most diverse and productive in the world. The mutualistic symbiosis between corals and photosynthetic dinoflagellates (symbionts) is central to these ecosystems. The rising temperatures are causing corals to lose their symbionts in a process known as bleaching, thus endangering the entire community. In this context, it is imperative to discover mechanisms that might mitigate the effects of stress on corals. Previous work has established that stress increases the formation of reactive oxygen species (ROS), that is, partially reduced forms of …

Investigation Of An Inquiry-Based Learning Intervention On Undergraduate Saudi Women’S Critical Thinking Skills In An English As A Foreign Language Reading And Writing Class During The Preparatory Year, Rehabe Tikruni

Graduate Research Theses & Dissertations

The purpose of this study was to investigate the implementation of an inquiry-based learning (IBL) intervention and its influence on the critical thinking (CT) skills of Saudi women undergraduates enrolled in an English as a Foreign Language (EFL) reading and

writing course during the preparatory year. This study utilized a qualitative case study design from one public university in Saudi Arabia during the second semester of the preparatory year English program in Fall 2018. Thirty-five women participated in the IBL intervention

and the pre- and post-reflective essays. To delve deeper into perceptions about IBL and its potential influence on critical …

Discovery Of Selective Probes Targeting Rna Polymerase I, Xiao Tan

Theses and Dissertations--Chemistry

RNR Polymerase I (RNA Pol I) is a “factory” that orchestrate the transcription of ribosomal rRNA for constructing ribosomes as a primary workshop for protein translation to sustain cell growth. Misregulation of RNA Pol I can cause uncontrolled cell proliferation, which leads to the development of cancer. Yeast (Saccharomyces cerevisiae) is a valuable model system to study RNA Pol I. Recently, the X-ray crystal structure of the yeast homologue of RNA Pol I was elucidated, offering the structural basis to selectively target this transcriptional machinery. The approach to selective RNA Pol I targeting was to disrupt the interaction …