Digital Commons Network^™

Public Understanding Of Chemistry Research In Print News, Michael D. Hands

Open Access Dissertations

Despite numerous calls for improving scientific literacy, many American adults show a lack of understanding of experiments, scientific study, and scientific inquiry. News media is one important avenue for science learning, but previous research investigating health and/or environmental science news has shown that it is inconsistent in the presentation of scientific research limitations, potentially impacting reader understanding. In the first phase of this dissertation, seventeen news articles reporting on a single chemistry research article, along with associated press releases and research articles, were analyzed using move analysis to determine the structure of each type of text. It was found that …

Making A Positive Change: A Qualitative Study Of Homeless Women’S Perceptions And Experiences Of Shelter Living, Natasha Schaefer Solle

Open Access Dissertations

The primary objective of this dissertation was to address factors that influenced homeless women’s health behaviors based on the theory of gender and power (TGP). A total of 18 participants described their experiences of being homeless, living in a shelter and its impact on their HIV risk behaviors. The interviews were framed by the constructs of the TGP, which included economic, physical, and social risk factors. The TGP describes the multiple social and structural factors that impact homeless women and their health risks. The TGP was chosen because of its adaptation by Wingood and DiClemente (2000), who exclusively tailored it …

Negative Regulation Of Host Innate Antiviral Signaling, Qinjie Zhou

Open Access Dissertations

The human T cell leukemia virus type I (HTLV-I) inhibits host antiviral signaling pathways although the underlying mechanisms are unclear. Here we found that the HTLV-I Tax oncoprotein induced the expression of SOCS1, an inhibitor of interferon signaling. Tax required NF-κB, but not CREB, to induce the expression of SOCS1 in T cells. Furthermore, Tax interacted with SOCS1 in both transfected cells and in HTLV-I transformed cell lines. Although SOCS1 is normally a short-lived protein, in the presence of Tax, the stability of SOCS1 was greatly increased. Accordingly, Tax enhanced the replication of a heterologous virus, vesicular stomatitis virus (VSV), …

The Evolutionary Maintenance Of Cooperative Nest Construction In Sociable Weavers (Philetairus Socius), Gavin Mclean Leighton

Open Access Dissertations

The evolutionary maintenance of cooperative behaviors, i.e. those behaviors that increase the fitness of other individuals, is difficult to explain because natural selection should eliminate behaviors that reduce an individual’s fitness. Despite this seeming disadvantage, cooperative behaviors permeate nature; indeed, many of the major evolutionary transitions require cooperation. The prevalence of cooperative behaviors suggests that mechanisms exist that allow for the evolution and maintenance of cooperation. In this dissertation I investigated the cooperative nest construction of sociable weavers Philetairus socius. Sociable weavers are colonial birds that roost and breed in large, communal nests; the communal nests provide thermal buffering, and …

The Role Of Sox9 In Heart Valve Maintenance And Disease, Danielle Huk

Open Access Dissertations

Heart valve disease results in over 23,000 deaths annually in the United States, with calcific aortic valve disease (CAVD) being the most prevalent (Go et al., 2014). To date, there are no pharmacological therapies to prevent or slow the progression of CAVD, and the only effective treatment involves surgical intervention (Beckmann et al., 2010). Mature aortic valve cusps are composed of a stratified trilaminar extracellular matrix (ECM) that provides the necessary biomechanical properties for function throughout life. It has been previously shown that several ECM proteins within these layers share molecular similarities with cartilage including the expression of type II …

Insertional Mutagenesis Screen Identifies Hace1 As A Her2 Cooperating Tumor Suppressor Whose Loss Results In Hyperactive Rac Signaling, Erik Tadashi Goka

Open Access Dissertations

The transformation from ductal carcinoma in situ (DCIS) to invasive breast cancer (IBC) is a crucial step in breast cancer progression. The specific alterations that govern this transition have not been elucidated. HER2/neu is frequently overexpressed in DCIS but is less common in IBC suggesting additional requirements for transformation. To identify genes capable of cooperating with HER2/neu to fully transform mammary epithelial cells, we used an insertional mutagenesis screen on cells isolated from wild-type neu expressing mice and identified the E3 ligase HACE1 as a HER2 cooperative tumor suppressor gene. Loss of HACE1 expression is commonly seen in clinical multiple …

Pathway To Autism Spectrum Disorders: Finding Patterns Of Common Genetic Variation Underlying The Complex Disorder, Yo Son Park

Open Access Dissertations

The field of genetics has witnessed a tremendous increase in the amount of information in the past decade resulting from genotyping and resequencing technologies. There has been an explosion in the development, application and optimization of statistical and computational methods to analyze these data. In particular, genome-wide scanning of common or rare genetic variants and their associations to a phenotypic trait has been successfully applied in several studies. For complex diseases such as Autism Spectrum Disorders (ASD), however, interrogating single locus associations by genome-wide association studies (GWAS) has been unable to unambiguously identify disorder causing genes. In this dissertation, an …

High Resolution Mass Spectrometric Approaches To Study Protein Structure And Environment In Lyophilized Solids, Lavanya Iyer

Open Access Dissertations

Proteins comprise a growing class of therapeutics that is used to treat various diseases such as diabetes and cancer. However, intrinsic structural features such as the primary sequence and extrinsic factors such as pH, temperature, agitation and metal ions can promote instability that manifests as chemical degradation (e.g. oxidation, deamidation, hydrolysis) and/or physical degradation (aggregation, phase separation). Since several degradation pathways are accelerated by diffusion in solution, proteins are lyophilized to improve stability. The lyophilized formulation may still undergo degradation during manufacture and/or storage. The mechanism of protein aggregation in lyophilized solids is not well understood or predictable by conventional …

Modeling, Analysis, And Control Of Syk-Mediated Signaling Events For B Cells And Associated Cellular Response For B Cells, Reginald Mcgee

Open Access Dissertations

Understanding the immune system and its responses to foreign threats (antigens) is a matter of understanding the immune cells involved, their individual responses, and chemicals responsible for intracellular and intercellular communication. The overall immune response is driven by individual actions of neutrophils, antigen-presenting cells, and lymphocytes (T cells and B cells), among other cells. Intercellular communication is the means by which immune cells develop coordinated response while intracellular signals determine responses within a cell; both depend on systems of chemical reactions at their respective scales. The perspective taken in this dissertation is that of understanding B cells at the intracellular …

Exploring The Phenomenon Of Chinese Babymoon Tourism, Ruoyang Zhang

Open Access Dissertations

The purpose of this study is to investigate the phenomenon of Chinese babymoon tourism. This phenomenon is gaining popularity in China but has not received due attention in academic research and from the tourism industry. The study aims to identify the backgrounds of young Chinese couples who participate in babymoon tourism, uncover the factors that motivate them to do so, and examine their travel behaviors that take place during such trips.

Shelf-Life Improvement Of Distillers Wet Grains With Solubles, Janie Denise Mcclurkin-Moore

Open Access Dissertations

Distillers wet grains with solubles (DWGS) is a co-product of the ethanol production using the dry-grind process. DWG is widely used as a feed and supplemental protein source in North American cattle rations. However due to its short shelf-life, 3-4 days in the summer and 7-10 days in the winter, its use is limited to cattle feeding facilities within close proximity to an ethanol production plant. It is known that the shelf-life of DWGS in the summer diminishes drastically compared to DWGS in the winter. This effect is primarily due to temperature, which drives mold growth in high moisture feedstocks. …

Development And Application Of Pseudoreceptor Modeling, Gregory Lee Wilson

Open Access Dissertations

Quantitative Structure-Activity Relationship (QSAR) methods are a commonly used tool in the drug discovery process. These methods attempt to form a statistical model that relates descriptor properties of a ligand to the activity of that ligand compound towards a specific desired physiological response. QSAR methods are known as a ligand-based method, as they specifically use information from ligands and not protein structural data. However, a derivation of QSAR methods are pseudoreceptor methods. Pseudoreceptor methods go beyond standard QSAR by building a model representation of the protein pocket. However, the ability of pseudoreceptors to accurately replicate natural protein surfaces has not …

Anticancer Effects Of Vitamin E Forms And Their Long-Chain Metabolites Via Modulation Of Sphingolipid Metabolism, Yumi Jang

Open Access Dissertations

Cancer is one of the leading causes of death. Studies have shown that vitamin E forms including gamma-tocopherol (γT), delta-tocopherol (δT), and gamma-tocotrienol (γTE) exhibited potent anticancer activities in various types of cancer cells. But molecular mechanisms underlying anticancer actions of γTE are not completely understood. 13’-carboxychromanols (13’-COOHs), major fecal excreted long-chain metabolites of vitamin E, have recently been shown to induce apoptosis in liver cancer cells. However, it is not clear whether 13’-COOHs have anticancer effects on other types of cancer. In the current study, we investigated the anticancer effects and mechanisms of γTE and 13’-COOHs; δT-13’-COOH and δTE-13’-COOH, …

Modeling Of Interface Strength As Well As Interface Deformation Based On Nanomechanics And Development Of Interface Database Systems, Tao Qu

Open Access Dissertations

Biomaterials such as bone and marine exoskeletons have primarily an organic phase (e.g. tropocollagen in bone, chitin in exoskeleton) and an inorganic phase (e.g. hydroxyapatite in bone, calcite in exoskeleton) arranged in a precisely organized multi-level hierarchical arrangement. Interfacial interactions between the organic and inorganic phases significantly affect the mechanical properties of such biomaterials. In presented study, idealized tropocollagen-hydroxyapatite and chitin-calcite interfacial systems are analyzed using a multiscale simulation framework that combines explicit three-dimensional molecular dynamics simulations with finite element simulations that take into account explicit microstructure in a three-dimensional hierarchy. The analyses focus on the shear deformation that occurs …

Improved Amorphous Solid Dispersion Performance Using Binary Polymer Combinations, Tian Xie

Open Access Dissertations

With increasing attrition rate of new molecular entities due to sub-optimum aqueous

Triplet Excitons In Natural Photosynthetic And Artificial Light Harvesting Systems: Measurement And Modeling., Daniel Allen Hartzler

Open Access Dissertations

Under full sunlight, unprotected (Bacterio)Chlorophyll ((B)Chl) molecules photodegrade in a matter of minutes. This is the result of the generation of highly reactive singlet oxygen (1O2) by energy transfer from the (B)Chl triplet state (3(B)Chl) to the oxygen ground state. Natural photosynthetic systems must protect themselves from 1O2, typically done by positioning carotenoids within a few angstroms of each (B)Chl molecule to quench 3(B)Chl states. Using phosphorescence spectroscopy and computational modeling, we investigated alternative, carotenoid independent, mechanisms which nature may employ to prevent 1O2 sensitization by lowering the energy of 3(B)Chl below that of 1O2. The two proposed triplet lowering …

Advanced Modeling And Efficient Optimization Methods For Real-Time Response In Water Networks, Arpan Seth

Open Access Dissertations

In response to a contamination incident in water distribution networks, effective mitigation procedures must be planned. Disinfectant booster stations can be used to neutralize a variety of contaminant and protect the public. In this thesis, two methods are proposed for the optimal placement of booster stations. Since the contaminant species is unknown a priori, these two methods differ in how they model the unknown reaction between the contaminant and the disinfectant. Both methods employ Mixed-Integer Linear Programming to minimize the expected impact over a large set of potential contamination scenarios that consider the uncertainty in the location and time of …

Integrating Molecular And Traditional Systematic Techniques To Redefine Red Algal (Rhodophyte) Diversity In The Bermuda Islands, Thea Ruth Popolizio

Open Access Dissertations

Molecular-assisted alpha taxonomy (MAAT) is a groundbreaking methodology that combines molecular tools with traditional morphological investigations. From studies using these methods, researchers can determine whether specimens with different morphologies are actually one entity exhibiting high phenotypic plasticity or are multiple genetic species with convergent morphologies, an important breakthrough for phycologists since algae are notoriously difficult to identify on morphology alone. Molecular-assisted techniques have also significantly increased the rate of novel species discovery among the algae, especially rhodophytes. From our own biodiversity assessments, we have learned that numerous members of Bermuda’s macroalgal flora have been misnamed, overlooked, or have not been …

Synchrony Capture Filterbank (Scfb): Auditory-Inspired Signal Processing For Frequency Tracking, Vijay Kumar Peddinti

Open Access Dissertations

The mammalian auditory system is a more robust and versatile sound analyzer than any artificial system that has been developed to date. Nature found a simple yet elegant solution for the hearing mechanism. Incorporating some key aspects of the functional organization of the mammalian auditory system into artificial signal-processing systems may drastically simplify problems of auditory representation and scene analysis such that capabilities for acoustic signal separation, detection, classification, recognition and identification can be greatly improved.

The objective of the thesis is to mimic the functionality of the mammalian peripheral auditory system in a digital computer by developing a synchrony …

An Investigation Of The Interactions Between Escherichia Coli And The Intestinal Microbiota In Vivo And In Vitro, Matthew E. Mokszycki

Open Access Dissertations

We previously proposed that colonizing strains of E. coli likely occupy specific niches as minimal members of mixed biofilms formed primarily by anaerobic members of the gut flora. These "restaurants" formed by the different community members of the gut provide individual strains of E. coli with various unique binding pockets and locally provided mono- and disaccharides by breaking down polysaccharides which facultative anaerobes, such as E. coli, could not break down on their own. This allows strains of E. coli that cannot grow as efficiently on available sugars to colonize if they are able to occupy niches that other …

Cellulose Synthesis In Physcomitrella Patens: Gene Expression And Mutational Analysis, Mai Linh Tran

Open Access Dissertations

A detailed analysis of cellulose synthesis in nonvascular plants can contribute to a better understanding of the evolution of this important process. In this study, the nonvascular plant Physcomitrella patens was used as a model system to investigate the roles of the different isoforms of cellulose synthase (CESA). PpCESA gene expression was quantified through Reverse Transcription quantitative (RT-q) PCR and localized through construction and analysis promoter::reporter lines to determine the roles of the PpCESAs throughout development. Physcomitrella patens CESA genes are ubiquitously expressed in the filamentous protonema stage. All of the PpCESAs are expressed in the gametophore as well, with …

Cyclodexrtrins As Hosts For The Array-Based Detection Of Persistent Organic Pollutants In Complex Media, Nicole Cook Serio

Open Access Dissertations

The ability to quickly determine the nature of small-molecule toxicants after an anthropogenic event would greatly benefit first responders and medical personnel. Current detection methods, while elegant, require several separation and purification steps before the samples can be submitted for analysis, which can be a time-consuming process. There is a crucial knowledge gap that exists as a result. Reported herein is the use of a non-toxic, commercially-available molecule, cyclodextrin, to rapidly isolate and detect the toxic components involved in a spill event that would address this knowledge gap. This cyclodextrin-based scheme would work as a compliment to established analysis procedures …

Evaluation Of In Vitro Anti-Inflammatory, Anti-Diabetic And Anti-Lipogenic Activity Of Natural Polyphenolic Extracts And Their Pure Constituents, Pragati P. Nahar

Open Access Dissertations

The long-term goals and objectives of our group are to identify bioactive natural products relevant to human disease prevention and health promotion. To attain this goal, the objective of this thesis was to demonstrate that bioactive polyphenol-rich extracts or preparations exert positive health benefits beyond basic nutrition, thus impacting overall health and wellness. We believe that this project has immense scientific merit from a human health perspective and will be of great public impact given that consumers are seeking natural and organic choices for improving health. In this investigation, we have focused our attention on investigating the biological activities of …

Insomnia And Identity: The Discursive Function Of Sleeplessness In Modernist Literature, Sarah Kingston

Open Access Dissertations

This dissertation examines the topic of insomnia in British and American modernist literature, focusing primarily on the ways in which the condition of insomnia and the identity category of the “insomniac” intersect with other aspects of subjectivity, such as gender, occupation, race, and social class. Through examining insomnia from a narratological perspective, using fictional, philosophical, psychological, sociological, and medical literature, I discuss the discursive function of both this disorder and identity category during the Modernist period. It also explores the relationship between insomnia and Modernism itself, regarding both the discursive production of knowledge of insomnia and the insomniac during this …

Exploring The Sociocultural Pathway Model As It Predicts Body Satisfacion In Athletes And Nonathletes, Sarah Howes-Masnik

Open Access Dissertations

This study was a secondary data analysis in which the sociocultural pathway model (Stice & Agras, 1998) was tested in male and female athletes and nonathletes. There were three primary purposes for this study. The first aim was to test the applicability of the sociocultural model theory in the current sample by conducting confirmatory factor analyses on the measurement constructs. The second aim was to create a structural equation model that fit the data best according to theoretical directionality of the constructs in the sociocultural theory. The third aim was to compare the predictive paths of this model across sexes …

Isco Of Volatile Organic Contaminants Using Peroxone Activated Persulfate & Cyclodextrin, Dylan E.H. Eberle

Open Access Dissertations

Despite recent advances, subsurface remediation of volatile organic compounds (VOCs), such as chlorinated solvents and petroleum hydrocarbons, remains a challenging environmental problem. As a result, the development of innovative methods for remediating subsurface VOC remains a major environmental priority. In addition to these priority pollutants, perfluoroalkyl compounds (PFCs) and 1,4-dioxane are contaminants of emerging concern due to their potential toxicity and prevalence in the environment. These emerging contaminants have increasingly been identified as co-contaminants at VOC release sites, and remediation strategies capable of treating VOC as well as 1,4-dioxane and PFCs would be of great value. In this dissertation, field …

Mass Spectrometric Studies On Petroleum Asphaltenes And Organosulfur Compounds, On Functional-Group Selective Ion-Molecule Reactions And On Gas-Phase Reactivity Of Meta-Benzynes Toward Amino Acids, Weijuan Tang

Open Access Dissertations

Mass spectrometry has found a wide variety of applications in many fields of study, such as fundamental chemistry, biological science, food and fuels, advanced materials, etc. Due to its high sensitivity, selectivity and speed, mass spectrometry provides an invaluable tool for direct mixture analysis. When coupled with separation methods, such as gas chromatography or high performance liquid chromatography, analysis of minor components in complex mixtures is possible. In addition to the molecular weight information, mass spectrometers can provide structural information for the ionized analyte molecules. However, mass spectrometric analysis of complex mixtures is not without challenges, such as suitable evaporation/ionization …

Quantifying Terrestrial And Aquatic Ecosystem Methane Emissions With Process-Based Biogeochemistry And Atmospheric Transport And Chemistry Models, Zeli Tan

Open Access Dissertations

To improve the quantification of methane emissions from Arctic wetlands and lakes, an integrated modeling framework was developed. It includes a newly developed process-based lake biogeochemical model and a widely used 4-D VAR inversion algorithm implemented with the nested grid high-resolution GEOS-Chem Adjoint model.

Enhancing The Bonding Of Synthetic Polymers Mimicking Marine Bioadhesives, Heather Jean Meredith

Open Access Dissertations

Marine organisms, such as mussels, are giving inspiration to a new generation of adhesive materials. The adhesive plaques of these shellfish are made up of proteins that contain a high amount of the amino acid, 3,4-dihydroxyphenylalanine (DOPA). This catechol moiety provides cross-linking chemistry that allows these animals to bond tightly to rocks and each other, even when wet. In developing synthetic mimics of mussel adhesive proteins, we are incorporating simplified forms of cross-linkable monomers into synthetic polymer backbones. One such example is poly[(3,4-dihydroxystyrene)-co-styrene] in which 3,4-dihydroxystyrene can provide cross-linking analogous to DOPA. In order to enhance adhesive bonding of these …

Quantitative Safety Assessment Of Air Traffic Control Systems Through System Control Capacity, Jingjing Guo

Open Access Dissertations

Quantitative Safety Assessments (QSA) are essential to safety benefit verification and regulations of developmental changes in safety critical systems like the Air Traffic Control (ATC) systems. Effectiveness of the assessments is particularly desirable today in the safe implementations of revolutionary ATC overhauls like NextGen and SESAR. QSA of ATC systems are however challenged by system complexity and lack of accident data.