Digital Commons Network^™

Precipitation Of Synthetic Dolomite At Low Tempearures With The Influence Of Microbes, Sreeram Jambulapati

Theses and Dissertations

New approaches in carbonate geochemistry are aiding geoscientists in

understanding dolomite formation. Dolomite is largely absent in modern depositional

environments but is present in ancient rocks. The current problem is the inability to

synthesize it under low-temperature conditions in the laboratory. Until recently

laboratory preparation of dolomite required elevated temperatures (<100oC) to overcome

kinetic barriers. One novel approach involves using bacteria to overcome the kinetic

barriers that have frustrated efforts to synthesize dolomite at near surface temperatures.

This study presents preliminary results of experiments in which three strains of bacteria

were used to inoculate a magnesium deficient amorphous calcium carbonate (Mg-ACC)

medium …

Mechanistic Insights Into Neutrophil Turnover During Gram-Negative Pneumonic Sepsis, Christopher Jondle

Theses and Dissertations

Sepsis is one of the oldest and most elusive syndromes in medicine. It is characterized by a systemic inflammatory response leading to acute organ dysfunction. In the United States alone there are over 750,000 cases of sepsis each year, with a mortality rate between 20-50%. Sepsis is the second leading cause of death in the ICU and the tenth leading cause of death overall in the United States. Over half of all ICU resources are consumed in the treatment of sepsis. There are currently no effective therapies available against sepsis, all attempts to develop an effective therapy have failed. Respiratory …

Functionalization Of Cyclopalladated Ligands Using Secondary Phosphines And Meta-Chloroperoxybenzoic Acid, Jonathan Kukowski

Theses and Dissertations

Cyclopalladation of organic ligands followed by reactions at the C–Pd bond with MPR2 (M = Li, K, or H) or other reagents (e.g. oxidants) is a desirable strategy for the synthesis of hemilabile bidentate ligands due to the large library of known cyclopalladated complexes (CPCs). This dissertation is composed of three projects on the functionalization of cyclopalladated ligands.

In the first study, a new method for (sp3)C–P bond formation using diphenylphosphine was studied. Conditions for the synthesis of aminophosphines were optimized for the reactions of dinuclear chloro-bridged (sp3)C–Pd CPCs and HPPh2. The best yields were obtained with 9 equivalents of …

Contextual Factors Related To Stereotype Threat And Student Success In Science Technology Engineering Mathematics Education: A Mixed Methods Study, Lindsey Leker

Theses and Dissertations

Stereotype threat is a widely researched phenomenon shown to impact performance in testing and evaluation situations (Katz, Roberts, & Robinson, 1965; Steele & Aronson, 1995). When related to gender, stereotype threat can lead women to score lower than men on standardized math exams (Spencer, Steele, & Quinn, 1999). Stereotype threat may be one reason women have lower enrollment in most science, technology, engineering, and mathematics (STEM) majors, hold a smaller number of STEM careers than men, and have a higher attrition rate in STEM professions (Hill, Corbet, & Rose, 2010; Picho & Brown 2011; Sorby & Baartmans, 2000). Most research …

The Impact Of The 340b Drug Pricing Program On Post-Launch Drug Prices, Bryan Temples Miller

Theses and Dissertations

Government mandated drug-pricing policies are an understudied—but potentially significant—factor in the price of drugs. The 340B program is one of the more controversial government-mandated prescription drug discount programs. Proponents argue that the program helps health care systems cover the cost of care they provide for low-income patients. Critics argue that the program unfairly benefits certain health care systems by assuring them lower drug prices, drives consolidation and reduces competition in the health care market, and drives up the cost of drugs. Despite this last claim, there is very little evidence that the 340B program actually impacts post-launch drug prices (i.e., …

The Role Of Α-Synuclein In Brain Lipid Metabolism And Inflammation, Drew R. Seeger

Theses and Dissertations

Alpha-synuclein (Snca) is a small cytosolic protein that is ubiquitously expressed in the nervous system and comprises 0.5-1% of all cytosolic protein, but its biological function is poorly understood. Although Snca function has been studied in lipid metabolism, the function of Snca in brain lipid metabolism under inflammatory conditions is yet to be elucidated. We utilized several model systems including primary cultured astrocytes and microglia, Snca deficient and mutant knock-in mice, and a radiolabeled free fatty acid steady state-kinetic mouse model to determine Snca role in neuroinflammation. Herein, we have determined several major roles of Snca during inflammation: (i) dBcAMP …

Epigenetic Remodeling As A Mediator Of Environmental Toxicant Exposure In The Brain, Christopher David Walden

Theses and Dissertations

Natural toxins and artificial toxicants are abundant throughout our environment and may play an integral role in remodeling our epigenome and in the development of neural diseases. Exposure to heavy metals and organic pollutants, such as DDT and its derivatives, have been linked to neural disease. Additionally, there are links between direct exposure, in both adults and children, to short-lived pesticides and neural diseases. While the link has been established, understanding the root cause has yet to be elucidated. One increasingly relevant field offering promise in achieving this goal is epigenetics. Epigenetic remodeling is one potential mechanism by which environmental …

Neural Networks In Strategic Marketing: Exploring The Possibilities, Kristen Bell Detienne, David H. Detienne

Faculty Publications

A review of the literature indicates that few studies have used artificial neural networks (ANNs) for data analysis in business and marketing research, even though there are many benefits to the use of ANNs. Therefore, this article discusses neural networks (NNs) that can be used in addition to or as an alternative to linear regression for data analysis in strategic marketing. The function and layout of NNs make them ideal for research dealing with nonlinear, incomplete, unspecified, or ‘fuzzy’ data and offer several advantages over linear regression. Unfortunately, in many marketing studies, the information being modeled is far from flawless …

Modeling Beta-Traces For Beta-Barrels From Cryo-Em Density Maps, Dong Si, Jing He

Computer Science Faculty Publications

Cryo-electron microscopy (cryo-EM) has produced density maps of various resolutions. Although ά-helices can be detected from density maps at 5-8 angstrom resolutions, β-strands are challenging to detect at such density maps due to close-spacing of β-strands. The variety of shapes of β-sheets adds the complexity of β-strands detection from density maps. We propose a new approach to model traces of β-strands for β-barrel density regions that are extracted from cryo-EM density maps. In the test containing eight β-barrels extracted from experimental cryo-EM density maps at 5.5 angstrom-8.25 angstrom resolution, StrandRoller detected about 74.26% of the amino acids in the β-strands …

An Effective Computational Method Incorporating Multiple Secondary Structure Predictions In Topology Determination For Cryo-Em Images, Abhishek Biswas, Desh Ranjan, Mohammad Zubair, Stephanie Zeil, Kamal Al Nasr, Jing He

Computer Science Faculty Publications

A key idea in de novo modeling of a medium-resolution density image obtained from cryo-electron microscopy is to compute the optimal mapping between the secondary structure traces observed in the density image and those predicted on the protein sequence. When secondary structures are not determined precisely, either from the image or from the amino acid sequence of the protein, the computational problem becomes more complex. We present an efficient method that addresses the secondary structure placement problem in presence of multiple secondary structure predictions and computes the optimal mapping. We tested the method using 12 simulated images from alpha-proteins and …

Comparing An Atomic Model Or Structure To A Corresponding Cryo-Electron Microscopy Image At The Central Axis Of A Helix, Stephanie Zeil, Julio Kovacs, Willy Wriggers, Jing He

Computer Science Faculty Publications

Three-dimensional density maps of biological specimens from cryo-electron microscopy (cryo-EM) can be interpreted in the form of atomic models that are modeled into the density, or they can be compared to known atomic structures. When the central axis of a helix is detectable in a cryo-EM density map, it is possible to quantify the agreement between this central axis and a central axis calculated from the atomic model or structure. We propose a novel arc-length association method to compare the two axes reliably. This method was applied to 79 helices in simulated density maps and six case studies using cryo-EM …

Homeomorphic Tetrahedral Tessellation For Biomedical Images, Jing Xu, Andrey N. Chernikov

Computer Science Faculty Publications

We present a novel algorithm for generating three-dimensional unstructured tetrahedral meshes for biomedical images. The method uses an octree as the background grid from which to build the final graded conforming meshes. The algorithm is fast and robust. It produces meshes with high quality since it provides dihedral angle lower bound for the output tetrahedra. Moreover, the mesh boundary is a geometrically and topologically accurate approximation of the object surface in the sense that it allows for guaranteed bounds on the two-sided Hausdorff distance and the homeomorphism between the boundaries of the mesh and the boundaries of the materials. The …

An Iterative Bézier Method For Fitting Beta-Sheet Component Of A Cryo-Em Density Map, Michael Poteat, Jing He

Computer Science Faculty Publications

Cryo-electron microscopy (Cryo-EM) is a powerful technique to produce 3-dimensional density maps for large molecular complexes. Although many atomic structures have been solved from cryo-EM density maps, it is challenging to derive atomic structures when the resolution of density maps is not sufficiently high. Geometrical shape representation of secondary structural components in a medium-resolution density map enhances modeling of atomic structures. We compare two methods in producing surface representation of the β-sheet component of a density map. Given a 3-dimensional volume of β-sheet that is segmented from a density map, the performance of a polynomial fitting was compared with that …

A Marine Heat Wave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks, Ariane Arias-Ortiz, Oscar Serrano, Pere Masqué, Paul Lavery, Ute A. Mueller, Gary A, Kendrick, Mohammad Rozaimi, Alba Esteban, James W, Fourqurean, Núrià N. Marbà, Miquel-Angel Mateo, Kathy Murray, Michael Rule, Carlos M. Duarte

Research Datasets

The database compiles published data (in Arias-Ortiz et al., 2018) on biogeochemical characteristics (density, organic carbon, stable carbon isotopes and sediment grain size) of soils underneath seagrass meadows in Shark Bay, Western Australia. Pb-210 concentrations of the first 20 cm are included along with C-14 raw ages. The dataset compiles data for a total of 49 cores, 25 - 300 cm-long (11 cores with Pb-210 and C-14 data).

Design And Evaluation Of Ballast Water Management Systems Using Modified And Hybridised Axiomatic Design Principles, Lawrence Kuroshi

World Maritime University Ph.D. Dissertations

There are two major motivations to this research. The first is based on the concerns raised at the International Maritime Organisation (IMO) MEPC 67 and 68 meetings regarding the capacity of some type-approved Ballast Water Management (BWM) Systems to meet the performance standard (D-2) of the BWM Convention at-all-times and in all conditions. The second is based on the reluctance expressed by some ship- owners to install the system onboard their ships as a Lloyd's list survey suggested.

In this work, an attempt was made to address these issues and concerns using a set of criteria stipulated in Regulation D-5.2 …

Development And Evaluation Of Quercetin Nanoparticles And Hot Melt Cast Films For Retinal Neuroprotection, Chau Truong

Honors Theses

The aim of this study was to prepare optimized nanoparticles and hot melt cast films of quercetin and to investigate the release and permeability profile across corneal membranes. The results demonstrate that all formulations can be successfully employed for delivery of quercetin into the eye through the topical route of administration, with films showing significantly better transcorneal permeability.

Taking Things At Face Value: Typeface And Its Influence On Reading, Memory, Judgment And Time Perception, Danielle Hollingsworth

Honors Theses

Differing typefaces, such as serif, sans serif, or script, offer varying physical characteristics and can aid or inhibit legibility. These distinctions between typefaces lead to fonts being deemed as either perceptually fluent or disfluent. As fluency of a text is altered, the notion is offered that processing changes occur, which can influence factors of reading a text. Altering fonts have previously been shown to influence reading speeds, memory, and time estimation judgment. This thesis tests the relationship of font type with these aspects, with the addition of another judgment portion regarding perception of text quality. Determining the aspects which can …

Comparative Effectiveness Of An Exercise And Sedentary Break Intervention On Mood Profile And Dietary Behavior In Young Adults: Pilot Study, Hannah Dau

Honors Theses

Exercise and sedentary behavior are both important subsets of PA (Physical Activity) to study, with emerging research demonstrating that sedentary behavior may predict mental health outcomes independent of PA. Additionally, a correlation has been observed between diet and PA, but few studies on this topic have employed an intervention design. Thus, the purpose of this study was to examine whether changes in PA and sedentary behavior influence mood profile and dietary behavior. The PA intervention consisted of progressively increasing their vigorous-intensity PA (jogging) over a 4-week period among an inactive population. The sedentary group was asked not to exercise, but …

Cannabidiol Mitigates Opioid Reward On Conditioned Place Preference In Mice, James Roland Markos

Honors Theses

This study sought to determine whether the cannabis constituent, cannabidiol (CBD), is able to attenuate morphine reward in the conditioned place preference (CPP) paradigm. Mice received IP injections of either saline or morphine and increasing doses of CBD that were paired with a distinct environment in the CPP apparatus. Morphine-produced place preference was dose-dependently blocked by CBD. Furthermore, none of the tested doses of CBD exhibited reward or aversion. The finding that CBD blocks opioid reward suggests CBD may be useful as an abuse deterrent, particularly in the setting of opioid use for pain management.

Oscillatory Neural Models Of The Basal Ganglia For Action Selection In Healthy And Parkinsonian Cases, R Borisyuk

School of Engineering, Computing and Mathematics

The neuronal circuits of the Basal Ganglia (BG) play an important role in movement control and it is known that without correctly functioning BG, the cortex’s ability to control movements is diminished. Parkinson’s disease (PD), for example, is primarily a disease of the basal ganglia. One aspect of pathological activity in the parkinsonian basal ganglia is an increase in synchronous oscillatory firing patterns

A Modular Architecture For Transparent Computation In Recurrent Neural Networks, Gs Carmantini, P Beim Graben, M Desroches, S Rodrigues

School of Engineering, Computing and Mathematics

Computation is classically studied in terms of automata, formal languages and algorithms; yet, the relation between neural dynamics and symbolic representations and operations is still unclear in traditional eliminative connectionism. Therefore, we suggest a unique perspective on this central issue, to which we would like to refer as transparent connectionism, by proposing accounts of how symbolic computation can be implemented in neural substrates. In this study we first introduce a new model of dynamics on a symbolic space, the versatile shift, showing that it supports the real-time simulation of a range of automata. We then show that the Gödelization of …

Development And Validation Of An Oecd Reproductive Toxicity Test Guideline With The Mudsnail Potamopyrgus Antipodarum (Mollusca, Gastropoda), K Ruppert, C Geiß, C Askem, R Benstead, R Brown, M Coke, V Ducrot, P Egeler, H Holbech, Th Hutchinson, Kl Kinnberg, L Lagadic, Page G Le, A Macken, P Matthiessen, S Ostermann, A Schimera, C Schmitt, A Seeland-Fremer, Aj Smith, L Weltje, J Oehlmann

School of Geography, Earth and Environmental Sciences

Mollusks are known to be uniquely sensitive to a number of reproductive toxicants including some vertebrate endocrine disrupting chemicals. However, they have widely been ignored in environmental risk assessment procedures for chemicals. This study describes the validation of the Potamopyrgus antipodarum reproduction test within the OECD Conceptual Framework for Endocrine Disrupters Testing and Assessment. The number of embryos in the brood pouch and adult mortality serve as main endpoints. The experiments are conducted as static systems in beakers filled with artificial medium, which is aerated trough glass pipettes. The test chemical is dispersed into the medium, and adult snails are …

Transfer Of Automatic Skills: The Role Of Automaticity In Skill Acquisition And Transfer, Katrina Louise Muller-Townsend

Theses: Doctorates and Masters

Skill acquisition theories suggest that automaticity of lower-level processes is required before the acquisition of higher-level skills can be attempted. However, there is a disparity between the theoretical expectations of skill acquisition and the empirical findings in the transfer of training research. Research has found that when a change is made to the contextual conditions in which a skill is acquired, the learned response becomes less skilled. When skill transfer occurs performance is disrupted so that reaction times are slower than observed prior to the context change. This observation has been made with several different tasks, however no research has …

“What Sort Of Communists Are You?” The Struggle Between Nationalism And Ideology In Poland Between 1944 And 1956, Jan Ryszard Kozdra

Theses: Doctorates and Masters

The period between 1944 and 1956, also known as the “Stalinist period”, is one of the most controversial and turbulent in Polish history. The Polish communist party launched the project of restructuring Polish society, whose historically wellestablished national identity seemed incompatible with the communist project. Firstly, the communists effected a demographic change that resulted in a near monoethnic state. Simultaneously, they introduced a centrally planned economy, transformed state symbolism, initiated a national education system, attempted to reshape popular attitudes to religion, and launched a massive propaganda campaign to reinforce and popularize their objectives.

This study seeks to investigate the communists’ …

The Business Of Trails, Kerstin Stender

Theses: Doctorates and Masters

Long distance trails have substantial infrastructure due to their length and provision of overnight shelters. Length and remoteness impact negatively on travel time for access, resulting in high maintenance costs. Additionally, as government budgets are declining globally, funding for trails can be difficult to source, leaving infrastructure to deteriorate.

This research investigated how long distance trails are managed, specifically from the perspective of a tourism product in a natural protected area. Global case studies were based on site visits and interviews with trail managers around the world, as well as a review of written documentation. Through comparative analysis the components …

Genetic Markers In Circulating Tumour Cells As A Measure Of The Metastatic Propensity Of Uveal Melanoma, Aaron Beasley

Theses: Doctorates and Masters

Background: Uveal melanoma (UM) is an extremely aggressive disease with approximately 50% of patients developing incurable metastatic disease. Therefore, accurate prognosis of a patient is necessary for closer follow up and the earlier implementation of systemic adjuvant therapies in those most likely to develop metastatic disease. Fortunately, UM can be classified into two distinct molecular classes based on clinically validated gene expression profiling, chromosomal aberrations and specific driver mutations, which accurately predict the metastatic propensity of the primary tumour. However, genetic testing currently requires biopsy of the eye which can lead to serious complications including permanent blindness. Therefore, an alternative …

The Performance Analysis Of Power Output In Professional Male Road Cyclists, Alan J. Metcalfe

Theses: Doctorates and Masters

Athletes regularly monitor exercise workload in an attempt to improve and maintain exercise performance. Within road cycling, workload is commonly measured using power output. Yet, it is plausible that power output during road cycling is influenced by several factors such as topography, road gradient or rider specialities. If these factors do influence power output they may influence quantification of workload demands. As such, the purpose of this thesis was to improve our understanding of external workload in professional road cycling and describe the factors which influence power output during performance analysis. Specifically, this thesis examined the power output within single …

Exploring The Experience Of Separation In Australia: Perspectives From Formerly Married And Cohabiting Parents, Sarah M. Barbas

Theses: Doctorates and Masters

The increase in separation and divorce rates during the 20th century brought with it many far-reaching social implications for all involved, sparking a high level of interest among researchers. Most research in this area has been approached from stress frameworks that have conceptualised separation and divorce as a stressful life transition that individuals must adjust to. Yet, attempts to understand separation and divorce to date have been dominated by quantitative methods that have resulted in a relatively static and objective understanding of this experience; particularly in Australia. Furthermore, although international rates of divorce are declining, rates of separation following cohabiting …

Optimisation Of The Isolation And Identification Of Circulating Melanoma Cells, Anda-Gabriela Marsavela

Theses: Doctorates and Masters

Although melanoma is largely curable when detected in its earliest stages, it can metastasise to other tissues, drastically reducing survival rates. The most recent therapies used to treat metastatic melanoma are effective long-term in only 11 to 33% of patients. Our ability to monitor treatment failure is limited. New prognostic markers are urgently required to allow monitoring of treatment response and disease progression.

Circulating tumour cells (CTCs) are released into the bloodstream by the tumours within a patient, this being a key step in melanoma spread. Since CTCs can be detected in the blood of metastatic melanoma patients, these cells …

A Nested Environmental Approach To Typhoid Epidemiology In Central Division, Fiji, Aaron Jenkins

Theses: Doctorates and Masters

Many current disease threats involve interactions within and between nested subsystems of biological organisation. Typhoid fever is a serious disease threat in the South Pacific region, with Fiji reporting the highest annual number of cases, yet risk factors in this setting have been poorly studied. While localised behaviours have dominated perspectives on typhoid transmission, interactions between distal ecological conditions, conditions of the residential environment and localised behaviour deserve greater attention for their potential to influence transmission. This thesis demonstrates a nested approach to typhoid epidemiology using a fivefold methodology to explore how regional, river basin, residential, socio-cultural and behavioural subsystems …