Digital Commons Network^™

Influence Of Soil Microorganisms On Plant Growth And Fitness, Benjamin Jayne

Electronic Theses and Dissertations

Most terrestrial plants benefit from symbiosis with soil microorganisms. Symbiotic bacteria and fungi have wide-ranging effects on host plants, including improved nutrition, disease resistance, and drought tolerance. Association with Arbuscular Mycorrhizal Fungi (AMF) can enhance growth and protect plants from environmental stressors while they share products of photosynthesis with the resident fungi. Scores of studies indicate that mycorrhizal plants are more resistant to drought stress than their non-mycorrhizal counterparts. Use of microbes as a plant and soil supplement in home gardens represents a sustainable alternative to resource-intensive inputs and may allow for reduced water use. I investigated the effects of …

An Exploratory Case Study Of Upper Elementary And Middle Level Science Instruction Impacting Traditionally Underserved Students, Lucinda Howe

Electronic Theses and Dissertations

This is an exploratory case study looking at the practices in one Colorado K-8 school that had students performing at or above the 75th percentile on the eighth grade Science Colorado Assessment of Student Progress (CSAP) in 2009. This study attempted to answer the question: What are the instructional choices, classroom environments, interventions, and school practices in place in one K-8 school that is supporting traditionally underserved populations of students in the learning of science? This school appears to be meeting the needs of their traditionally underserved students as evidenced by the percent of students in these populations at this …

Aladdin's Magic Lamp: Developing Methods For Calibration And Geolocation Accuracy Assessment Of The Dmsp Ols, Benjamin Taylor Tuttle

Electronic Theses and Dissertations

Nighttime satellite imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) has a unique capability to observe nocturnal light emissions from sources including cities, wild fires, and gas flares. Data from the DMSP OLS is used in a wide range of studies including mapping urban areas, estimating informal economies, and estimating urban populations. Given the extensive and increasing list of applications a repeatable method for assessing geolocation accuracy, performing inter-calibration, and defining the minimum detectable brightness would be beneficial. An array of portable lights was designed and taken to multiple field sites known to have no other …

A Hydrodynamic Method For Measuring Aqueous Nanoparticle Surface Interactions, Kellen John Sorauf

Electronic Theses and Dissertations

The objectives of this research dissertation were to develop and present novel analytical methods for the quantification of surface binding interactions between aqueous nanoparticles and water-soluble organic solutes. Quantification of nanoparticle surface interactions are presented in this work as association constants where the solutes have interacted with the surface of the nanoparticles. By understanding these nanoparticle-solute interactions, in part through association constants, the scientific community will better understand how organic drugs and nanomaterials interact in the environment, as well as to understand their eventual environmental fate. The biological community, pharmaceutical, and consumer product industries also have vested interests in nanoparticle-drug …

A Novel Link Between Akt1 And Twist1 In Ovarian Tumor Cell Motility And Invasiveness, Nirav Shah

Electronic Theses and Dissertations

Ovarian cancer results in more deaths per year than any other cancer of the female reproductive system. The low survival rate is partly due to the lack of early detection and the susceptibility to relapse. The AKT serine threonine kinase plays a pivotal role in hallmark cellular processes for the progression of ovarian cancer, including tumor cell growth and migration. Therapeutic targeting of pan-AKT has been problematic, in part due to feedback mechanisms and crosstalk with other pathways. The hypothesis for this study is that AKT 1, -2 and -3 isoforms may have different roles and regulate cell processes in …

Species And Habitat Interactions Of The Gopher Tortoise: A Keystone Species?, Christopher Catano

Electronic Theses and Dissertations

Species-species and species-habitat interactions have been demonstrated to be important in influencing diversity across a variety of ecosystems. Despite generalities in the importance of these interactions, appropriate mechanisms to explain them are absent in many systems. In sandhill systems of the southeast U.S., gopher tortoises have been hypothesized to be a crucial species in the maintenance of diversity and function. However, the mechanisms and magnitude in which they influence their communities and habitats have rarely been empirically quantified. I examined how habitat structure influences tortoise abandonment of burrows and how tortoise densities influence nonvolant vertebrate community diversity. Tortoise burrow abandonment …

Determining The Impacts Of Beach Restoration On Loggerhead (Caretta Caretta) And Green Turtle (Chelonia Mydas) Nesting Patterns And Reproductive Success Along Florida's Atlantic Coast, Allison Whitney Hays

Electronic Theses and Dissertations

Artificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, the ratio of nests to the total number of nests and non-nesting emergences, and reproductive success, the ratio of hatched and emerged hatchlings to the total number of eggs deposited. Two …

Beliefs And Technology - Does One Lead To The Other? Evaluating The Effects Of Teacher Self-Efficacy And School Collective Efficacy On Technology Use In The Classroom, Elaine Studnicki

Electronic Theses and Dissertations

This exploratory mixed method study builds upon previous research to investigate the influence of teacher self- and collective efficacy on technology use in the classroom. This population was purposefully sampled to examine first- and second order technology barriers, instructional strategies, and human influences on technology. The quantitative finding was supported by qualitative analysis of the teacher interviews and led to the conclusion that even thought there were strong teacher tendencies towards a belief in using technology actual practice demonstrated a lack of productivity or transference of that belief into classroom practice. A high self- and collective efficacy had no effect …

The Awareness Of Computer-Mediated Communication's Social Presence For Virtual High School Students, Heather Bigley

Electronic Theses and Dissertations

This research investigated the perception of social presence that students in a virtual high school have of using computer-mediated communication (CMC): email, discussion board, tutoring sessions, and asynchronous classroom activities. The research analyzed data for social presence based on gender, years of experience in a cyber school, and self-proficiency ratings on each form of CMC. The purpose of this study was to identify if high school students in a virtual community perceive email, discussion board, tutoring sessions and asynchronous classroom activities as enhancing their social presence within the virtual community. The findings of the study are:

1. Students perceived that …

King Of The Hill's Souphanousiphones, The New Model Minority, And The Subversive Model Minority, Robert Reece

Electronic Theses and Dissertations

Though the term "model minority" was only coined in the 1960s to apply to Asian-Americans, in the white imagination, a "model" way to be a minority has always existed. This model has gone through various iterations from the "happy" blacks of the antebellum years to supposedly over-achieving Asian-Americans of the 1960s. I argue that we are witnessing the emergence of a new model minority that includes not only Asian-Americans but other high-achieving minorities as well. This model minority is characterized by economic success, formal education, American values, and conservative racial politics or a complete silence about race. Because an inability …

Infrasound As Upper Atmospheric Monitor, Jelle Daniel Assink

Electronic Theses and Dissertations

Understanding and specification of the higher altitudes of the atmosphere with global coverage over all local times is hampered by the challenges of obtaining direct measurements in the upper atmosphere. Methods to measure the properties of the atmosphere above the stratopause is an active area of scientific research. In this thesis, we revisit the use of infrasound as a passive remote sensing technique for the upper atmosphere. Signals from the Tungurahua volcano in Ecuador are used to investigate the behavior of the upper atmosphere. Depending on the atmospheric conditions, stratospheric, mesospheric and thermospheric arrivals are observed during intervals of explosive …

Phylogenetic Community Structure Of Aquatic Beetle Assemblages In A Multi-Wetland Experiment, Sandor Lawrence Kelly

Electronic Theses and Dissertations

Phylogenetic Community Structure (PCS) metrics are becoming more common in community ecology. PCS metrics estimate the phylogenetic relatedness among members of an ecological community or assemblage. If ecological traits are conserved, then phylogenetic clustering (i.e., taxa are more closely related than expected by chance) indicates habitat filtering as the key process in community assembly. On the other hand, a pattern of phylogenetic overdispersion (i.e., taxa are more distantly related than expected by chance) suggests competition is dominant. Most studies to date have used PCS of unmanipulated ecosystems, but the value of PCS metrics will be best revealed in experiments. This …

Direct Measurement Of Thicknesses, Volumes Or Compositions Of Nanomaterials By Quantitative Atomic Number Contrast In High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy, Biao Yuan

Electronic Theses and Dissertations

The sizes, shapes, volumes and compositions of nanoparticles are very important parameters determining many of their properties. Efforts to measure these parameters for individual nanoparticles and to obtain reliable statistics for a large number of nanoparticles require a fast and reliable method for 3-D characterization. In this dissertation, a direct measurement method for thicknesses, volumes or compositions of nanomaterials by quantitative atomic number contrast in High-Angle Annular Dark-Field (HAADF) Scanning Transmission Electron Microscopy (STEM) is presented. A HAADF detector collects electrons scattered incoherently to high angles. The HAADF signal intensity is in first-order approximation proportional to the sample thickness and …

Third Order Nonlinearity Of Organic Molecules, Honghua Hu

Electronic Theses and Dissertations

The main goal of this dissertation is to investigate the third-order nonlinearity of organic molecules. This topic contains two aspects: two-photon absorption (2PA) and nonlinear refraction (NLR), which are associated with the imaginary and real part of the third-order nonlinearity (χ (3)) of the material, respectively. With the optical properties tailored through meticulous molecular structure engineering, organic molecules are promising candidates to exhibit large third-order nonlinearities. Both linear (absorption, fluorescence, fluorescence excitation anisotropy) and nonlinear (Z-scan, two-photon fluorescence, pump-probe) techniques are described and utilized to fully characterize the spectroscopic properties of organic molecules in solution or solid-state form. These properties …

Molecular Mechanisms Involved In Inflammatory Angiogenesis Induced By Monocyte Chemotactic Protein Induced Protein-1 (Mcpip1), Arpita Roy

Electronic Theses and Dissertations

Major diseases such as cardiovascular diseases, diabetes, obesity and tumor growth are known to involve inflammatory angiogenesis. MCP-induced protein 1 (MCPIP1) encoded by ZC3H12A gene, was reported to promote angiogenesis and is addressed in my dissertation as MCPIP. The mechanism/s involved in the angiogenic differentiation induced by MCPIP was however unknown. The aim of this study was to bridge this gap in our knowledge and delineate the molecular mechanisms and sequential processes involved in angiogenesis mediated via MCPIP. To determine if angiogenesis induced by inflammatory cytokines, TNF-, IL-1 and IL-8 is mediated via induction of MCPIP, knockdown of MCPIP by …

Infraded Surface Plasmon Polaritons On Semiconductor, Semimetal And Conducting Polymer, Monas Shahzad

Electronic Theses and Dissertations

Conductors with IR (infrared) plasma frequencies are potentially useful hosts of surface plasmon polaritons (SPPs) with subwavelength mode confinement for sensing applications. The underlying aim of this work is to identify such conductors that also have sharp SPP excitation resonances for biosensor applications at infrared (3-11 m) wavelengths, where biological analytes are strongly differentiated by their IR absorption spectra. In this work, various materials were investigated such as a heavily doped semiconductor, a semimetal, a conducting polymer and its composite. Heavily doped silicon was investigated by tuning its plasma frequency to the infrared region by heavily doping. The measured complex …

The Behavior Of Cerium Oxide Nanoparticles In Polymer Electrolyte Membranes In Ex-Situ And In-Situ Fuel Cell Durability Tests, Benjamin Pearman

Electronic Theses and Dissertations

Fuel cells are known for their high efficiency and have the potential to become a major technology for producing clean energy, especially when the fuel, e.g. hydrogen, is produced from renewable energy sources such as wind or solar. Currently, the two main obstacles to wide-spread commercialization are their high cost and the short operational lifetime of certain components. Polymer electrolyte membrane (PEM) fuel cells have been a focus of attention in recent years, due to their use of hydrogen as a fuel, their comparatively low operating temperature and flexibility for use in both stationary and portable (automotive) applications. Perfluorosulfonic acid …

Landscaping Perceptions And Behaviors: Socio-Ecological Drivers Of Nitrogen In The Residential Landscape, Leesa Souto

Electronic Theses and Dissertations

Driven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen inputs to aquatic systems requires a better understanding of the links between residential landscape management and the potential for fertilizer loss. This dissertation examines the linkages between the human behaviors …

The Relationship Between Identity And Intimacy As Moderated By Culture, Garima Jhingon

Electronic Theses and Dissertations

Several important developmental processes occur in the young adulthood period. Young adults form their identities, determine trajectories regarding careers, and typically they form intimate relationships. Erikson (1963) stated that healthy identity development during adolescence is a necessary precursor to intimacy in romantic relationships during emerging adulthood. Although findings from cross-sectional and short-term longitudinal studies somewhat confirm the proposed link between identity and intimacy development, none of them addresses the role of culture in moderating Erikson‘s tenets of developmental ordering. The primary goal of the present investigation was to determine the role of cultural orientation in identity and intimacy development among …

Understanding Phonological Memory Deficits In Boys With Attention-Deficit/Hyperactivity Disorder (Adhd): Dissociation Of Short-Term Storage And Articulatory Rehearsal Processes, Jennifer Bolden

Electronic Theses and Dissertations

The current study dissociated and examined the two primary components of the phonological working memory subsystem – the short-term store and articulatory rehearsal mechanism – in boys with ADHD (n = 18) relative to typically developing boys (n = 15). Word lists of increasing length (2, 4, and 6 words per trial) were presented to and recalled by children following a brief (3 s) interval to assess their phonological short-term storage capacity. Children’s ability to utilize the articulatory rehearsal mechanism to actively maintain information in the phonological short-term store was assessed using word lists at their established memory span but …

Predictors Of Immunosuppressant Adherence In Long-Term Renal Transplant Recipients, Sandra J. Galura

Electronic Theses and Dissertations

To sustain the health and viability of renal transplants, adherence to immunosuppressant therapy (IST) medications is critical. Studies continue to identify decreased adherence rates as time from transplant increases (Chisholm-Burns, Kwong, Mulloy & Spivey, 2008; Chisholm, Lance, Mulloy, 2005; Chisholm, Mulloy, & DiPiro, 2005; Nivens & Thomas, 2009). While previous research has explored the effect of variables known to influence IST adherence in adult renal transplant recipients, limited studies have explored these variables in a population of renal transplant recipients with longer time posttransplant intervals. The purpose of this study was to examine demographic variables, time posttransplant, immunosuppressive agents, health …

The Dynamic Functions Of Bax Are Dependent On Key Structural And Regulatory Features, Rebecca Boohaker

Electronic Theses and Dissertations

Bax is an essential mediator of cell fate. Since its discovery in 1985 as a protein that interacts with the anti-apoptotic protein, Bcl-2, key elements related to its function, structure and regulation remains to be determined. To this end, mitochondrial metabolism was examined in non-apoptotic Bax-deficient HCT-116 cells as well as primary hepatocytes from Bax-deficient mice. Although mitochondrial density and mitochondrial DNA content was the same in Bax-containing and Bax -deficient cells, MitoTracker staining patterns differed, suggesting the existence of Bax -dependent functional differences in mitochondrial physiology. Oxygen consumption and cellular ATP levels were reduced in Bax -deficient cells, while …

Is It Choice Or Is It Interest?: The Effect Of Choice And Interest On The Cognitive And Affective Engagement Of Elementary Students Performing A Reading Task, Jerilyn Scott

Electronic Theses and Dissertations

The author replicated and extended a study by Flowerday, Schraw, & Stevens (2004) that examined the effects of choice, topic interest, and situational interest on reading engagement, attitude, and learning in college-age students. The study was replicated using fourth and fifth graders as subjects. The study was extended to examine the effects of gender and reading ability cohort on the outcome measures. Participants randomly assigned to the choice condition made a blind choice of Packet A or B containing a non-fiction essay to read; participants assigned to the no choice condition were given one of the packets without being offered …

Diverse Sample Analysis And Sample Preparation Studies Utalizing Ap - Maldi-Tof-Ms, Sara May Kallop

Electronic Theses and Dissertations

Sample preparation and analysis for atmospheric pressure matrix assisted laser desorption ionization time of flight mass spectrometry (AP- MALDI-TOF-MS) was investigated. By investigating the effects that sample preparation has upon MALDI signal, better analysis can be carried out. The influence of sample deposition was studied by not only observing the signal intensity produced but also by quantitation. Isotope dilution mass spectrometry (IDMS) was used for the quantitation of three different analytes. The results indicated that not only was signal greatly affected by sample deposition but the effect on quantitation error was also statistically significant among the three different sample deposition …

Algorithms For Community Identification In Complex Networks, Mahadevan Vasudevan

Electronic Theses and Dissertations

First and foremost, I would like to extend my deepest gratitude to my advisor, Professor Narsingh Deo, for his excellent guidance and encouragement, and also for introducing me to this wonderful science of complex networks. Without his support this dissertation would not have been possible. I would also like to thank the members of my research committee, professors Charles Hughes, Ratan Guha, Mainak Chatterjee and Yue Zhao for their advice and guidance during the entire process. I am indebted to the faculty and the staff of the Department of Electrical Engineering and Computer Science for providing me the resources and …

A Laser Radar Employing Linearly Chirped Pulses From A Mode-Locked Laser For Long Range, Unambiguous, Sub-Millimeter Resolution Ranging And Velocimetry, Mohammad Umar Piracha

Electronic Theses and Dissertations

Light detection and ranging (lidar) is used for various applications such as remote sensing, altimetry and imaging. In this talk, a linearly chirped pulse source is introduced that generates wavelength-swept pulses exhibiting ~6 nm optical bandwidth with > 20 km coherence length. The chirped pulses are used in an interferometric lidar setup to perform distance measurements with sub-millimeter resolution (using pulses that are a few meters long), at target distances > 10 km, with at least 25 dB signal-to-noise ratio at the receiver. A pulse repetition rate of 20 MHz provides fast update rates, while chirped pulse amplification allows easy amplification of …

Evolution Through The Search For Novelty, Joel Lehman

Electronic Theses and Dissertations

I present a new approach to evolutionary search called novelty search, wherein only behavioral novelty is rewarded, thereby abstracting evolution as a search for novel forms. This new approach contrasts with the traditional approach of rewarding progress towards the objective through an objective function. Although they are designed to light a path to the objective, objective functions can instead deceive search into converging to dead ends called local optima. As a significant problem in evolutionary computation, deception has inspired many techniques designed to mitigate it. However, nearly all such methods are still ultimately susceptible to deceptive local optima because they …

Bst-Inspired Smart Flexible Electronics, Ya Shen

Electronic Theses and Dissertations

The advances in modern communication systems have brought about devices with more functionality, better performance, smaller size, lighter weight and lower cost. Meanwhile, the requirement for newer devices has become more demanding than ever. Tunability and flexibility are both long-desired features. Tunable devices are ‘smart’ in the sense that they can adapt to the dynamic environment or varying user demand as well as correct the minor deviations due to manufacturing fluctuations, therefore making it possible to reduce system complexity and overall cost. It is also desired that electronics be flexible to provide conformability and portability. Previously, tunable devices on flexible …

4d-Ct Lung Registration And Its Application For Lung Radiation Therapy, Yugang Min

Electronic Theses and Dissertations

Radiation therapy has been successful in treating lung cancer patients, but its efficacy is limited by the inability to account for the respiratory motion during treatment planning and radiation dose delivery. Physics-based lung deformation models facilitate the motion computation of both tumor and local lung tissue during radiation therapy. In this dissertation, a novel method is discussed to accurately register 3D lungs across the respiratory phases from 4D-CT datasets, which facilitates the estimation of the volumetric lung deformation models. This method uses multi-level and multi-resolution optical flow registration coupled with thin plate splines (TPS), to address registration issue of inconsistent …

Rare Earth Oxide Coating With Controlled Chemistry Using Thermal Spray, Virendra Singh

Electronic Theses and Dissertations

Cerium oxide (Ceria) at nano scale has gained significant attention due to its numerous technological applications. Ceria in both doped and undoped forms are being explored as oxygen sensor, catalysis, protective coating against UV and corrosion, solid oxide fuel cell (SOFC) electrolyte and newly discovered antioxidant for biomedical applications. Therefore, there is an imminent need of a technology which can provide a cost effective, large scale manufacturing of nanoceria and its subsequent consolidation, specially using thermal spray. This dissertation aims to develop a scientific understanding towards the development of pure and doped ceria- based coating for a variety of technological …