Digital Commons Network^™

Comparing High School Students' And Adults' Perceptions Of Technological Literacy, Henry Ladson Harrison Iii

STEMPS Theses & Dissertations

This study compared high school student's perceptions of technology and technological literacy to those perceptions of the general public. Additionally, individual student groups were compared statistically to determine significant differences between the groups. The ITEA/Gallup Poll instrument was used to survey high school student's perceptions of technology in the study. The instrument has been used twice (2001, 2004) in the United States and once (2005) in Hong Kong to survey adult's perceptions of technology. The student population in question consisted of three subgroups: students enrolled in a standards-based technology education courses, students enrolled in a Project Lead the Way® (PLTW®) …

Traumatic Stress As A Predictor Of Suicidality, Sherry Malana Todd

Counseling & Human Services Theses & Dissertations

Suicide is a deliberate act of annihilation against one's self due to a crisis of problem solving. Far too many youth are dying by their own hands resulting in suicide being the third leading cause of death for 10-19 year olds (CDC, 2005). Suicide is particularly problematic for adolescents due to the impulsivity inherent in adolescent development. Since 1980, the national suicide rate of African American youth has increased by 114 percent (CDC). Suicidality has been positively correlated with depression and posttraumatic stress disorder (PTSD; Kessler et al., 1999). Suicidality is more prevalent when a person experiences a tragic or …

Analysis Of N-Linked Oligosaccharides Of Prostate-Specific Antigen And Prostatic Acid Phosphatase In Prostatic Fluids, Krista Yaudes White

Theses and Dissertations in Biomedical Sciences

Presently, prostate cancer is the most common cancer afflicting men in the United States, with serum PSA being the "gold standard" protein biomarker used in the clinic for detecting and diagnosing prostate cancer. Nonetheless, serum PSA levels can also be elevated in non-cancerous conditions as well, such as benign prostatic hyperplasia (BPH). Due to this overlap, many unnecessary biopsies and radical prostatectomies occur, leading to patient distress. Despite recent advances to clinical assays which consider other clinical parameters, there is still a great need for improved clinical detection methodologies for prostate cancer, including improved biomarkers. Therefore, this research project aims …

Ecology And Molecular Phylogenetics Of Hydnora (Hydnoraceae) In Southern Africa, Jay Francis Bolin

Biological Sciences Theses & Dissertations

The Hydnoraceae are a clade of root holoparasitic angiosperms that contain two small genera, Hydnora and Prosopanche. This study, focused on Hydnora, presents novel data regarding the pollination biology, germination ecology, parasite-host nutritional relationships, and the molecular systematics of this group. Experimental addition of the primary pollinator, Dermestes maculatus to Hydnora africana chamber flowers demonstrated beetle imprisonment during the carpellate stage. Changes in the inner surfaces of the androecial chamber allowed beetle escape after pollen release. Most beetles escaped, dusted with viable pollen, three days after pollen release. To investigate germination ecology, aqueous root extracts of host and …

Ecology Of Neotropical Arboreal Snakes And Behavior Of New World Mollusk-Eating Snakes, Julie M. Ray

Biological Sciences Theses & Dissertations

The Neotropics is a biologically diverse region that provides man opportunities for ecological and behavioral studies. I utilized the speciose ophidian fauna of central Panama to explore the general ecology of arboreal snakes, the defensive behaviors of the snake community, and the diet of mollusk-eating snakes. I studied arboreal species to understand interspecilic relationships in several morphometric characters and to examine preferences in habitat. There were significant morphometric differences in relative length of jaw, mass, tail length, and size at midbody. The arboreal realm was partitioned among species by distance to ground, distance to water, and diameter of the perch. …

Small Rna-Directed Heterochromatin Formation In The Context Of Development: What Flies Might Learn From Fission Yeast, Kathryn Huisinga, Sarah C.R. Elgin

Biology Faculty Research

A link between the RNAi system and heterochromatin formation has been established in several model organisms including Schizosaccharomyces pombe and Arabidopsis thaliana. However, the data to support a role for small RNAs and the associated machinery in transcriptional gene silencing in animal systems is more tenuous. Using the S. pombe system as a model, we analyze the role of small RNA pathway components and associated small RNAs in regulating transposable elements and potentially directing heterochromatin formation at these elements in Drosophila melanogaster.

Amyloid Aggregation-Mitigating Peptides As Potential Alzheimer's Drugs, Cyrus Kipkurui Bett

LSU Doctoral Dissertations

Neuronal cytotoxicity observed in Alzheimer¡¦s disease (AD) is linked to the aggregation of £]-amyloid peptide (A£]) into toxic forms. Increasing evidence points to oligomeric species as the neurotoxic species compared to fibrils; disruption or inhibition of A£]ƒnself-assembly into oligomeric or fibrillar forms remains a viable therapeutic strategy to reduce A£] neurotoxicity. Amyloid aggregation mitigating peptides (AAMPs) were designed based on the A£]ƒn¡§hydrophobic core¡¨ A£]17-20, with C£\,£\-disubstituted amino acidsƒnƒv£\£\AAs) added into this core as disrupting agents. The number, distribution, and side chain functionality of £\£\AAs incorporated into the mitigator sequence was found influences the resultant aggregate morphology as indicated by ex-situ …

Dynamics And Rheology Of Biaxial Liquid Crystal Polymers, Sarthok K. Sircar

Theses and Dissertations

In this thesis we derive a hydrodynamical kinetic theory to study the orientational response of a mesoscopic system of nematic liquid crystals in the presence of an external flow field. Various problems have been attempted in this direction. First, we understand the steady-state behavior of uniaxial LCPs under an imposed elongational flow, electric and magnetic field respectively. We show that (1) the Smoluchowski equation can be cast into a generic form, (2) the external field is parallel to one of the eigenvectors of the second moment tensor, and (3) the steady state probability density function is of the Boltzmann type. …

The Effects Of Varying Seeding Rates Of Bouteloua Curtipendula And Mowing On Native Plant Establishment In A New Prairie Reconstruction, Ryan Leon Welch

Dissertations and Theses @ UNI

A major problem early in prairie reconstruction is weed competition. Research has shown that mowing in the first year can increase establishment and survival of prairie plants. The use of nurse crops (companion crops) has been suggested as an alternative to mowing for weed suppression. The goal of this study was to examine various seeding rates of B. curtipendula, as a nurse crop in mowed and unmowed plots to determine if it suppressed weeds and aided in the establishment of natives. We hypothesized that increasing the seeding rate of B curtipendula will reduce weed growth and promote an increase in …

F₂-Isoprostanes Study After Exposure To Selected Nanoparticles By Liquid Chromatography/Tandem Mass Spectrometry And Investigation Of Nanoparticles On The Cytotoxicity Effect Of Arsenic In Vitro, Xiaoqian Liu

Doctoral Dissertations

"Nanopartices as a new class of materials found their applications in industry, aerospace, clinical diagnosis and cancer therapy. Recently, the health effects of nanoparticles have caused people great concerns. This dissertation studies the mechanisms of nanoparticle cytotoxicity in human lung epithelial cells (A549). F₂-isoprostanes are novel reliable biomarkers for lipid peroxidation. In the first part of this work, total free F₂-isoprostanes were quantified by high performance liquid chromatography/mass spectrometry followed by the exposure of SiO₂ (15 nm), CeO₂ (20 nm), Fe₂O₃ (30 nm), and ZnO (70 nm) nanoparticles for 24 hours. For the first time, the results showed that F₂-isoprostanes …

The Role Of Stochastic Resonance And Physical Constraints In The Evolution Of Foraging Strategy, Nathan Daniel Dees

Doctoral Dissertations

"This work represents a detailed study of the optimization of this process: foraging within a single, finite food patch for a limited amount of time. The work is an example of the computational algorithms of statistical physics being applied to the ecological field of foraging behavior. The analysis begins with an examination of the probability distributions observed in the movement parameters of the zooplankton, Daphnia. While foraging, these small aquatic organisms stochastically choose movement parameters with particular levels of variation, or noise, which are similar across several species. Here, related simulations consistently show that these noise levels may be adjusted …

On Unified Computational Intelligence: Neural Networks, Dynamic Programming, And Applications To Economics And Finance, John E. Seiffertt Iv

Doctoral Dissertations

"This dissertation introduces the concept of unified computational intelligence and encompasses algorithm design, applications, theoretical developments, and the identification of new frontiers for multidisciplinary research. It presents a new way to look at unified learning systems and presents a novel Adaptive Resonance Theory-based unified learning architecture. An application to robotic security and sensor fusion is given in detail.

Work on the theoretical developments of unified computational intelligence is also presented. A new theorem in the time scales calculus is proven and theorems on the Hamilton-Jacobi-Ballman equation of dynamic programming and the dynamic programming algorithm are presented, both for various general …

Investigating The Impact Of Microbial Interactions With Geologic Media On Geophysical Properties, Caroline A. Davis

Doctoral Dissertations

"The goals of this study were to investigate the effect of: (1) microbial metabolic byproducts, microbial growth, and biofilm formation on the low frequency electrical properties of porous media, (2) biofilm formation on acoustic wave properties, and (3) the natural electrical (self-potential) signatures associated with an in-situ biological permeable reactive barrier (PRB). The results suggest: (1) increases in electrolytic conductivity are consistent with increased concentrations of organic acids and biosurfactants; (2) mineral weathering promoted by organic acids causes increases in electrolytic conductivity, concomitant with increases in major cation concentrations; (3) interfacial conductivity generally parallels microbial cell concentrations and biofilm formation; …

Membrane Properties Of Intact Rock Cores Of Burlington Limestone, Jefferson Dolomite, Darrington Phyllite, And Low Permeability Concrete, Megan Hart

Doctoral Dissertations

"A number of laboratory studies have shown that clays exhibit membrane properties. However, little research has been performed on lithologies outside of pure clays. Recently, research focusing on mixed sand and clay membrane properties for engineering applications was performed. Still, literature only suggests the possibilities of membrane properties, osmotic or reverse-osmotic, associated with other naturally occurring 'tight' rock types. Therefore, the objectives of this research was to perform a series of hyperfiltration experiments using actual rock discs of Quarry Ridge Jefferson Dolomite, Darrington Phyllite, Lower Burlington Limestone, and low permeability concrete to determine if tight lithologies can function as membranes"--Abstract, …

Coiled-Coil-Mediated Dimerization Is Not Required For Myosin Vi To Stabilize Actin During Spermatid Individualization In Drosophila Melanogaster, Tatsuhiko Nogushi, Deborah J. Frank, Mamiko Isaji, Kathryn G. Miller

Biology Faculty Research

Myosin VI is a pointed-end-directed actin motor that is thought to function as both a transporter of cargoes and an anchor, capable of binding cellular components to actin for long periods. Dimerization via a predicted coiled coil was hypothesized to regulate activity and motor properties. However, the importance of the coiled-coil sequence has not been tested in vivo. We used myosin VI's well-defined role in actin stabilization during Drosophila spermatid individualization to test the importance in vivo of the predicted coiled coil. If myosin VI functions as a dimer, a forced dimer should fully rescue myosin VI loss of function …

Formation Control Of Mobile Robots And Unmanned Aerial Vehicles, Travis Alan Dierks

Doctoral Dissertations

"In this dissertation, the nonlinear control of nonholonomic mobile robot formations and unmanned aerial vehicle (UAV) formations is undertaken and presented in six papers. In the first paper, an asymptotically stable combined kinematic/torque control law is developed for leader-follower based formation control of mobile robots using backstepping. A neural network (NN) is introduced along with robust integral of the sign of the error (RISE) feedback to approximate the dynamics of the follower as well as its leader using online weight tuning. Subsequently, in the second paper, a novel NN observer is designed to estimate the linear and angular velocities of …

Investigation Of The Interactions Between Selected Nanoparticles And Human Lung Carcinoma Cells At The Single Cell And Single Particle Level, Isaac Stayton

Doctoral Dissertations

"The recent advances in nanomaterials development and applications have sparked concerns regarding the safety of these materials in living organisms. This body of work investigates specific interactions between chosen nanoparticles and living human lung carcinoma (A549) cells"--Abstract, page iv.

The Role Of Astrocyte Activation In Infantile Neuronal Ceroid Lipofuscinosis, Shannon Macauley-Rambach

All Theses and Dissertations (ETDs)

Infantile neuronal ceroid lipofuscinoses: INCLs), or Batten Disease, is an inherited neurodegenerative lysosomal storage disorder affecting the central nervous system: CNS) during infancy or childhood. Hallmark pathological changes include accumulation of autofluorescent material, neuronal loss, cortical thinning, and brain atrophy, which ultimately lead to cognitive deficits, motor dysfunction, seizure activity, and blindness. INCL is the result of mutations in the CLN1 gene leading to a deficiency in the lysosomal enzyme, palmitoyl protein thioesterase 1: PPT1). A mouse model of INCL, the PPT1-deficient: PPT1-/-) mouse, was recently created by a targeted disruption in the CLN1 gene. The phenotype of the PPT1-/- …

Training And Transfer Of Attentional Control In Older Adulthood, Anna Mackay-Brandt

All Theses and Dissertations (ETDs)

Recent research in cognitive aging has brought renewed interest to a decades old question. Can cognitive skills be trained, and if so, how widely does that trained skill transfer? Previous research has demonstrated that older adults are able to improve their performance on laboratory cognitive tests and in some cases these benefits can transfer to other similar tests: e.g. Kramer et al., 2004). A few cases have demonstrated transfer to more distal outcomes: Willis et al., 2006). This area of research is still in an early stage, and reports are mixed with regard to the efficacy of cognitive training. These …

Who Uses Community-Based Youth Shelters? An Inter-Group And Intra-Group Analysis, Jennifer Mcclendon

All Theses and Dissertations (ETDs)

Community-based youth shelters are the primary method of intervention designed to meet the complex needs of at-risk youth who leave home before they have developed the skills to live independently. This research examines shelter users' patterns of cross-sector service use to better understand the needs and resources of shelter residents. The aims of this study are 1) to perform an inter-group analysis, comparing sheltered youth with status offense runaways and foster care runaways, and 2) to explore the population of emergency shelter residents using an intra-group analysis, determining whether distinct profiles of sheltered youth exist, based on individual characteristics and …

Aggregation & Localization Of A Disease-Associated Prion Protein (Prp) Mutant, Andrea Rhonda Medrano

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION Aggregation & Localization of a Disease-Associated Prion Protein: PrP) Mutant by Andrea Rhonda Zaragoza Medrano Doctor of Philosophy in Biology and Biomedical Sciences: Genetics) Washington University in St. Louis, 2009 Professor David A. Harris, Chairperson Prion protein: PrP) is a GPI-anchored sialoglycoprotein involved in the pathogenesis of infectious and inherited forms of transmissible spongiform encephalopathies: TSEs). A nine-octapeptide insertional mutation in the prion protein: PrP) causes a fatal neurodegenerative disorder in both humans and transgenic mice. To determine the precise cellular localization of this mutant PrP: designated PG14), we have generated transgenic mice expressing PG14-EGFP, a …

Structural Rna Homology Search And Alignment Using Covariance Models, Eric Nawrocki

All Theses and Dissertations (ETDs)

Functional RNA elements do not encode proteins, but rather function directly as RNAs. Many different types of RNAs play important roles in a wide range of cellular processes, including protein synthesis, gene regulation, protein transport, splicing, and more. Because important sequence and structural features tend to be evolutionarily conserved, one way to learn about functional RNAs is through comparative sequence analysis - by collecting and aligning examples of homologous RNAs and comparing them. Covariance models: CMs) are powerful computational tools for homology search and alignment that score both the conserved sequence and secondary structure of an RNA family. However, due …

Time-Weighted Average Solid-Phase Microextraction (Twa-Spme) For In-Planta Detection Of Chlorinated Solvents, Emily Moore Sheehan

Masters Theses

"Recent interest in the use of phyto-mapping for plume delineation at contaminated sites has promoted a need for new and innovative sampling techniques. Solid-phase micro-extraction (SPME) methods have been developed as a chemical analysis tool offering fast, simple, non-invasive sampling without the use of solvents. In this study SPME devices were tested for applicability for in-planta detection of chlorinated solvents. To evaluate the use of SPME for VOCs in-planta a number of integrated studies were undertaken. Uptake profiles were developed for nine chlorinated solvents in a liquid polydimethylsiloxane (PDMS) matrix with 100 µm Carboxene SPME fibers. Timeweighted average (TWA) sampling …

Expression Analysis And Stem Cell Engineering, Cara Rieger

All Theses and Dissertations (ETDs)

The overall goal of the thesis was to develop tools to advance Investigations of stem cells in tissue engineering therapeutics for neurodegenerative disease and spinal cord injury. Two tools to characterize cell fate and a tool to separate a subset of neural cells were developed and evaluated. In the first study, a digital PCR technology, called polonies, was applied to measure mRNA from several key stem cell genes in small numbers of ES cells. Due to its properties, we hypothesized that polonies would be uniquely poised to profile stem cells. Polonies were counted for Oct3 in a sample of 10 …

Identification And Characterization Of A Xylosylphosphotransferase Of Cryptococcus Neoformans, Morgann Reilly

All Theses and Dissertations (ETDs)

Cryptococcus neoformans is an environmental yeast and an opportunistic pathogen capable of causing a meningoencephalitis in human hosts. The organism produces an extensive polysaccharide capsule that is unique among pathogenic fungi and absolutely required for its virulence. Work in the Doering laboratory on the capsule and other glycoconjugates of C. neoformans has focused on the identification of glycosyltransferases, enzymes that catalyze the transfer of a sugar moiety from an active donor to a specific acceptor, creating a particular linkage. Previous work demonstrated that xylose residues, derived from the nucleotide sugar UDP-xylose, are necessary for cryptococcal virulence. An assay to detect …

Subunit Compositions Of Arabidopsis Dna-Dependent Rna Polymerases And The Roles Of The Plant-Specific Rna Polymerases Iv And V In Gene Silencing, Thomas Ream

All Theses and Dissertations (ETDs)

In addition to RNA polymerases I, II and III, the essential RNA polymerases present in all eukaryotes, plants have two additional nuclear RNA polymerases, abbreviated as Pol IV and Pol V, that play non-redundant roles in siRNA-directed DNA methylation and gene silencing. Using a combination of affinity purification and protein identification by mass spectrometry, my studies show that Arabidopsis Pol IV and Pol V are composed of subunits that are paralogous or identical to the twelve subunits of Pol II. Four subunits of Pol IV are distinct from their Pol II paralogs, six subunits of Pol V are distinct from …

Improving Biocompatibility By Controlling Protein Adsorption: Modification And Design Of Biomaterials Using Poly(Ethylene Glycol) Microgels And Microspheres, Evan Scott

All Theses and Dissertations (ETDs)

Guided by the clinical needs of patients and developments in biology and materials science, the primary focus of the biomaterials field remains at the solid/liquid interface between biomaterial surfaces and biological fluids. For blood-contacting devices, biological responses are initially elicited and directed by proteins that adsorb from this multicomponent solution to form thin films on their surfaces. The identity, conformation, and quantity of adsorbed proteins are related to the properties of a material's surface. For example, hydrophobic surfaces tend to be thrombotic via interactions between platelets and adsorbed fibrinogen, while surface-activation of specific enzymes initiates the coagulation cascade on hydrophilic …

Functional Significance Of Glycoprotein Clearance By The Asialoglycoprotein Receptor And The Mannose/Galnac-4-So4 Receptor, Lindsay Steirer Taylor

All Theses and Dissertations (ETDs)

Glycosylation plays an important role in many biological functions. Two highly abundant, carbohydrate-specific, endocytic receptors reside in parenchymal and endothelial cells of the liver. Our lab has shown that the asialoglycoprotein receptor: ASGR) is capable of clearing glycoproteins bearing terminal Siaalpha2,6GalNAc as well as ones bearing terminal Gal/ GalNAc and that the Mannose/GalNAc-4-SO4 receptor: MR) is capable of clearing glycoproteins bearing terminal GalNAc-4-SO4. I am taking a genetic approach identifying endogenous ligands for the ASGR and the MR in vivo and establishing the biologic significance of clearing these glycoproteins from the blood. A number of glycosylated hormones such as luteinizing …

Developing New Methodologies For Crosslinked Polymeric Nanostructure Syntheses, Chemoselective Modifications, And Applications As Imaging And Delivery Agents, Guorong Sun

All Theses and Dissertations (ETDs)

The overall emphasis of this dissertation research includes the syntheses of amphiphilic block copolymers bearing functional groups through controlled radical polymerization techniques, followed by the aqueous assembly of these block copolymer precursors to construct polymeric nanostructures with different sizes and morphologies. Further chemical modification of the nanostructures afforded functional crosslinked nano-objects with reporting probes for imaging and biocompatible "stealth" materials for tuning the in vivo fate of nanostructures. Amphiphilic block copolymers poly(acrylic acid)-block-polystyrene: PAA-b-PS) with well-defined structures were prepared through nitroxide-mediated radical polymerization: NMP). Using novel pre-functionalization strategies, these block copolymer precursors were functionalized with DOTA for chelating 64Cu and …

Structually Diverse Cu-64-Labeled Rgd Peptide Conjugates For Pet Imaging Of Αvβ3 Expression, Ashley Fiamengo

All Theses and Dissertations (ETDs)

Radiolabeled receptor-binding peptides have emerged as an important class of radiopharmaceuticals for diagnostic imaging and cancer therapy. Following radionuclide labeling, the specific receptor-binding properties of the ligand can be exploited to guide the radioactivity to tissues expressing a particular receptor. This dissertation reports on the development of integrin α_vβ₃-targeting radiopharmaceuticals for medical imaging applications from the perspective of both the radiometal-labeled chelator as well as the targeting peptide. Several macrocyclic copper(II) chelators have been studied with the goal of improving kinetic and in vivo stability. Structurally diverse bifunctional RGD: arginine-glycine-aspartic acid) peptides were investigated for α …