Digital Commons Network^™

Digitally-Controlled Deep Brain Stimulation Lead Implant System, Matthew Joseph Phillips

Master's Theses

Deep brain stimulation, the treatment of disorders by applying electrical stimulation to brain tissue, is a relatively new field of medicine with great potential to provide cures for neurological disorders. It utilizes a system very similar to a cardiac pacemaker and lead to electrically stimulate brain tissue. This electrical stimulation is programmed to disrupt or mask aberrant brain signals while not impeding the normal function of the brain. The advances in implantable pulse generators designed for deep brain stimulation have been remarkable, and the applications for deep brain stimulation continue to grow including multiple sclerosis (Berk, et al. 2002), severe …

Impedance-Based Detection Of Tissue Using A Multi-Electrode Device, Shane Killian Fleshman

Master's Theses

Melanoma skin cancer is the abnormal growth of the melanocytes – the pigmented cells located in the epidermis. The current gold standard diagnostic technique for determining whether a lesion is cancerous involves subjectively examining suspicious lesions and performing an invasive biopsy to confirm melanoma. This method may neglect some lesions or cause scarring from biopsies that turn out to be benign. Thus, impedance-based detection using a multi-electrode device was investigated as a noninvasive technique to diagnose melanoma skin cancer. The multi-electrode device was designed with 8 equally spaced Ag/AgCl electrodes surrounding one central electrode at a 5 mm radius. The …

Living With Emerging Contaminants: Proteomics Of 4-Nonylphenol Exposed Arrow Goby (Clevelandia Ios), Sarah Emily Johnson

Master's Theses

Alkylphenol ethoxylates (APEs) are widely used in industrial and household products as surfactants. APEs degrade into more toxic ethoxylates, such as 4-nonylphenol (NP), which has been shown to be an endocrine disruptor and enhance the growth of tumor cells. Nonylphenol is wider spread in Pacific estuaries than originally thought. Organisms in Morro Bay, California contain some of the highest concentrations of NP reported, while containing few other contaminants. As a benthic mud-dwelling fish, the arrow goby (Clevelandia ios) may be exposed to high levels of NP due to high contaminant sequestration rates in anaerobic mud. While ecotoxicology suggests …

Cubesat Constellation Analysis For Data Relaying, Bradley Ryan Smalarz

Master's Theses

Current CubeSat communication technology limits the amount of time, and number of accesses with ground stations. It has been proposed to use a constellation of CubeSats to improve relay performance and increase the number of accesses between a CubeSat and ground stations. By using the spatial and temporal analysis features of STK, coupled with the STK/Matlab interface a robust tool was created to analyze the performance of CubeSat constellations based on a store-and-forward communications model which is not currently supported by the STK Engine. Utilizing the Connect messaging format through a socket connection on the local machine, a Matlab graphical …

State Estimation For Tracking Of Tagged Sharks With An Auv, Christina Forney

Master's Theses

Presented is a method for estimating the planar position, velocity, and orientation states of a tagged shark. The method is designed for implementation on an Autonomous Underwater Vehicle (AUV) equipped with a stereo-hydrophone and receiver system that detects acoustic signals transmitted by a tag. The particular hydrophone system used here provides a measurement of relative bearing angle to the tag, but does not provide the sign (+ or -) of the bearing angle. A particle filter was used for fusing measurements over time to produce a state estimate of the tag location. The particle filter combined with an active control …

The Influence Of Chilling And Heat Accumulation On Bloom Timing, Bloom Length And Crop Yield In Almonds (Prunus Dulcis (Mill.)), Melanie M. Covert

Master's Theses

Almonds are one of the first commercial nut trees to bloom in early spring and thus are susceptible to temperature patterns prior to and during bloom which affect bloom timing, bloom length, pollination and nut set. Data used in this project include yearly dates of 90% bloom from 1996-2006, bloom length in days and final crop yields in pounds per tree for Nonpareil and Mission varieties. Data were collected from the University of California Cooperative Extension reports on the 1993-2006 Regional Almond Variety Trials in Butte, San Joaquin and Kern Counties. Temperature pattern models in the form of Chill Hours …

Response To Management Strategies In Young-Growth Giant Sequoia Stands At Mountain Home Demonstration State Forest – Remeasurement Twenty Years After Treatment, Joshua Soderlund

Master's Theses

There is limited information on how young-growth giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz)/mixed conifer stands respond to forest management strategies. An applied research study was initiated in 1989 when 35 approximately 0.1 acre (0.04 hectare) plots were installed in six young-growth giant sequoia/mixed conifer stands. The objective of this study was to determine if there was a difference after 20 years between treatments (a) thin only, (b) thin and prescribe burn, and (c) control in terms of the effect on overstory growth and yield, understory plants, tree regeneration and downed woody debris. Analysis of variance (ANOVA) for cubic-foot growth …

Unusual Electron Transfer Rate Effects Due To Pyridyl Ring Substituents And Trace Group Viii B Hexacyano Complexes As Added Salts, Faisal Mehmood

Master's Theses

The rates of pseudo-self-exchange electron transfer reactions between [(NH₃)₅Ru^IIL]²⁺ and [(NH₃)₅Ru^IIIL’]³⁺ at reactant concentrations of 1.0 х 10^-4 M (where L, L’ = substituted pyridines) and the reaction between [(NH₃)₅Ru^IIPy]²⁺ and [(NH₃)₅Ru^III3FPy]²⁺ at different reactant concentrations in the presence of various salts added were studied by using the stopped-flow kinetic spectroscopy. Marcus theory rate vs. driving force plots yielded distinct families of lines depending on whether a 3- or 4- …

Investigating The Roles Of Ndj1 And Tid1 In Crossover Assurance In Saccharomyces Cerevisiae, Rianna Knowles

Master's Theses

Meiosis is the specialized process of cell division utilized during gametogenesis in all sexually reproducing eukaryotes, which consists of one round of DNA replication followed by two rounds of chromosome segregation and results in four haploid cells. Crossovers between homologous chromosomes promote proper alignment and segregation of chromosomes during meiosis.

Crossover interference is a genetic phenomenon in which crossovers are non-randomly placed along chromosomes. Crossover assurance ensures that every homologous chromosome pair obtains at least one crossover during Prophase I. Crossovers physically connect homologous pairs, allowing spindle fibers to attach and separate homologs properly. However, some organisms have shown an …

Decontamination Of Endodontic Gutta-Percha: An In-Vitro Study, Mariya Shnaydman

Master's Theses

No abstract provided.

Upper Salinas Headwaters Conservation Plan, Justin T. Saydell

Master's Theses

The Upper Salinas Headwaters Conservation Plan is an effort to understand the cultural and ecosystem resources in the region, develop tools for conservation planning, and suggest a strategy and plan of action for implementation of those strategies. The plan covers a 218 square mile area between the Santa Lucia and the La Panza mountain ranges, south of Atascadero and east of the City of San Luis Obispo. The Conservation Area consists of rugged terrain made up of vast-relatively untouched open space. The area consists of several different vegetative communities including oak savannah grasslands, mixed hardwood and oak stands, shrubland, wetland …

Development And Prototyping Of A Ground Fault Circuit Interrupter For 3-Phase 480 Volt Systems, Matthew R. Norlander

Master's Theses

Ground Fault Circuit Interrupter (GFCI) technology was first introduced in the NEC in 1971, yet four decades later the technology has not been introduced to a great extent outside of the home environment. This thesis introduces the difficulties encountered in low-voltage three phase ground fault current detection, and adopts a previously patented tripping scheme to develop and prototype a digital relay for 3-phase 480 volt systems capable of the sensitivity and speed required for personnel safety. Results demonstrate the feasibility of the concept and suggest commercial development should be pursued. The prototype is capable of mA sensitivity and reliably detects …

Quantification Of Nitrate Sources And Sinks Using A Water Quality Network In Morro Bay Estuary, California, Johanna Nadia Jean Weston

Master's Theses

Using an instrumented water quality network in Morro Bay Estuary, California from 2007 to 2010 (15 min sampling frequency), this study addressed the two objectives of constructing a nitrate budget and assessing the influence of sampling frequency on water quality parameters. These two objectives led to the submission of an original report of research (Appendix A) and a note (Appendix B) to peer-reviewed journals.

The first objective was to characterize the high spatial and temporal variation in physical parameters and nitrate concentrations and to construct a nitrate budget quantifying sources and sinks of nitrate from the ocean, streams, and groundwater, …

Accurate Estimation Of Isoform And Gene Expression Levels From Next Generation Sequencing Data, Marius Nicolae

Master's Theses

Massively parallel transcriptome sequencing is quickly replacing microarrays as the technology of choice for performing gene expression profiling due to its wider dynamic range and digital quantitation capabilities. However, accurate estimation of expression levels from sequencing data remains challenging due to the short read length delivered by current sequencing technologies and still poorly understood protocol- and technology-specific biases.

To date, two main transcriptome sequencing protocols have been proposed in the literature. The most commonly used one, referred to as RNA-Seq, generates short (single or paired) sequencing tags from the ends of randomly generated cDNA fragments. An alternative protocol, referred to …

Understanding Formation And Transport Of Amorphous Iron Oxyhydroxides In Porous Media Using Microfluidic Flow Cells- A Novel Method To Study Freshwater Iron Cycling, Neha A. Ghaisas

Master's Theses

The ground water and surface water interface (GSI or Hyporheic zone) is a spatially- and temporally-fluctuating biogeochemical transition zone connecting these two distinct hydrological components. The mixing zone is characterized by a near neutral pH, ambient temperature and a sharp oxygen concentration which in turn has deep impact on the iron cycling and thus the fate of contaminants in the water column. We constructed an experimental micromodel that to observe key processes that affect biogeochemical iron cycling in the fresh water interface zones where the oxic surface water mixes with Fe (II) rich underlying ground water. The flow cell was …

Classifying And Mapping Diversity In A Species-Poor System: The Mangrove Meta-Community Of Laguna Chacahua National Park, Oaxaca, Mexico, Elizabeth Kay Weisgerber

Master's Theses

ABSTRACT

Classifying and Mapping Diversity in a Species-Poor System: the mangrove meta-community of Laguna Chacahua National Park, Oaxaca, Mexico

by

Elizabeth Kay Weisgerber

Both field transects and imagery grid plots were analyzed with the goal of creating a community classification map for the mangrove forest of Parque Nacional Lagunas de Chacahua. In total, data was collected in 49 sites throughout the park, recording measures such as DBH, basal area, estimated dominance, frequency, cover and relative dominance. Field locations were marked and georeferenced with a GPS and grid plots overlaid on satellite imagery of the park were generated via a random …

Protective Effects Of Milk Phospholipids Against Uv Photodamage In Human Skin Equivalents, Zyra Achay

Master's Theses

The ultraviolet (UV) spectrum has been known to cause damage to skin in varying degrees. UVB radiation (290-320 nm) in particular, has been proven to be highly mutagenic and carcinogenic in many animal experiments compared to either UVA or UVC. The alarming rate of increase in skin cancer incidence has prompted many investigators to pursue other alternatives to sunscreens including changes in lifestyle habits and dietary consumption in order to boost our efforts in tackling this widespread disease. Previous studies employing confocal reflectance, MTT assay and histology suggest that milk phospholipids may possess protective properties against UVB-mediated damage but the …

Stromatolitic Knobs In Storrs Lake, San Salvador, Bahamas: Insights Into Organomineralization, Alexandre J. Fowler

Master's Theses

Storrs Lake, a hypersaline lake on the east coast of San Salvador Island, Bahamas, contains well-developed microbial mats, some of which have developed calcified structures called microbialites. Many of these microbialites are laminated, and therefore classified as stromatolites. This study focuses on small stromatolitic knobs located in the southern portion of Storrs lake, which are still actively forming, to gain insights into the early stages of stromatolite formation. These knobs appear to be forming as the result of in situ micritic precipitation mediated by both photosynthetic and heterotrophic microbial metabolisms. By comparing these small stromatolitic knobs to larger stromatolitic heads …

Automation Of Orthodontic Wire Tester For Performing Three Point Bending Tests, Adithya Venkatesan

Master's Theses

Abstract

Understanding the biomechanical factors in orthodontics is important in order to improve the overall effectiveness of actual clinical treatment. An accurate method to study the threedimensional (3D) force systems and the resulting movements of teeth during orthodontic treatment is needed along with the understanding of the material properties of any orthodontic wire. Until recently, most of the orthodontic biomechanics literature was limited to twodimensional experimental studies. Recent advances in threedimensional computer modeling have also been developed but have been limited to the manual control of tooth movement. Overall, there is very little published evidence in the literature on the …

Fabrication And Characterization Of Zno/Cuo Core-Shell Nanowire Arrays, Kuo-Ting Liao

Master's Theses

Research into nanomaterials has become more and more popular because of their unique properties compared to bulk materials. Amongst various functional materials, zinc oxide (ZnO), with a direct electron energy band gap of 3.34 eV at room temperature, is an important optoelectronic material with an intrinsically n-type semiconducting property. However, to form a p-type ZnO semiconductor is still a challenge. Copper oxide (CuO), compared to ZnO, has a much smaller band gap, 1.2 eV, and shows an intrinsically p-type semiconducting property. It has been suggested that when CuO is alloyed with ZnO properly, a p-n semiconductor heterojunction can be formed …

Effect Of Prostaglandin E2 On Mechanical Stresses Applied By Mc3t3-E1 Osteoblast-Like Cells On A Soft Hydrogel Substrate, Abhijit Deb Roy

Master's Theses

Osteoblasts are sensitive to mechanical stimuli and release Prostaglandin E2 (PGE2) when exposed to a fluid shear stress. The exact mechanism by which these cells sense mechanical stress is not well established. A study of the stresses applied by the osteoblasts, under the influence of PGE2, on a hydrogel provided information regarding intercellular-communication via changes in the substrate surface pattern.

A digital image correlation program was developed using the Levenberg-Marquardt optimization algorithm to analyze images and compare the deformations between pairs of images. Comparisons of images before and after the addition of PE2 to the media showed differences in the …

Dissolved Organic Matter Characterization And Impact On Mercury Binding In An Urbanizing Watershed, Mykel Mendes

Master's Theses

Dissolved organic matter (DOM) is ubiquitous in aquatic ecosystems, interacting with and controlling the bioavailability and transport of mercury (Hg) and other trace metals through complexation. The complexation of ionic Hg (Hg²⁺) with DOM can either limit methyl mercury (MeHg) bioavailability or increase MeHg production by stimulating microbial growth. While substantial investigations have examined Hg-DOM interactions in forested ecosystems, little research has been conducted on the Hg-DOM relationship within an urbanized river setting subjected to various anthropogenic sources. The various runoff and pollutant sources vary in DOM quality and character. Three sources of organic matter from the North …

Intact Statistical Word Learning In Autism Spectrum Disorders, Jessica Mayo

Master's Theses

Individuals with Autism Spectrum Disorders (ASD) have impairments in language acquisition, but the underlying mechanism of these deficits is poorly understood. Implicit learning appears potentially relevant to language development, particularly in speech segmentation, which relies on sensitivity to the transitional probabilities between speech sounds. This study aimed to investigate the relationship between implicit learning and current language abilities in school-aged children with autism (n = 17) and typical development (n = 24) using a well-studied artificial language learning task. Results suggest that the ASD and TD groups were equally able to implicitly learn transitional probabilities from a lengthy …

Aronia Mitschurinii: Solving A Horticultural Enigma, Peter J. Leonard

Master's Theses

Aronia (Medik.), commonly known as chokeberry, is a taxonomically misunderstood genus currently experiencing a renaissance in North America as both an ornamental and fruit crop. Three species of chokeberry are commonly accepted as native in North America: A. arbutifolia (L.) Pers. red chokeberry; A. melanocarpa (Michx.) Elliot, black chokeberry; and A. prunifolia (Marshall) Rehder, or purple chokeberry. In Europe a fourth species of human origin is recognized as Aronia mitschurinii (A.K.Skvortsov & Maitul.), or cultivated, black-fruited Aronia. It is widely speculated that this genotype originated in the early 20^th century with Russian pomologist Ivan Michurin, as the product …

Glucose Biosensor Using Electrospun Mn2o3-Ag Nanofibers, Shan Huang

Master's Theses

The highly porous Mn₂O₃-Ag nanofibers were fabricated by a facile two-step procedure (electrospinning and calcination) and then employed as the immobilization matrix for glucose oxidase (GOD) to construct an amperometric glucose biosensor. A notable enhancement of direct electron transfer between GOD and the electrode is observed at the Mn₂O₃-Ag-GOD modified electrode with a fast electron transfer rate constant. The biosensor also shows fast response to glucose, high sensitivity (40.60 μA×mM^-1×cm^-2), low detection limit (1.73 µM at S/N=3), low K_m,app value and excellent selectivity. These results indicate that …

The Expression Of T-Box (Tbx3) In The Bovine Mammary Gland, Maria L. Procopio Ms.

Master's Theses

Development of the bovine mammary gland is a complex process that is regulated by several hormones, growth factors and transcription factors including but not limited to growth hormone (GH), insulin-like growth factor (IGF)-I and T-box (Tbx)2 and 3. Tbx2 and Tbx3 are transcription factors required for mammary gland development in humans and known to regulate cell cycle. In addition, there is recent evidence that GH increases expression of Tbx3 in osteoblasts independent of IGF-I. Based on these findings, we hypothesized GH and IGF-I will increase Tbx2 and Tbx3 expression in bovine mammary epithelial cells (MEC), the cell responsible for milk …

Ros-Drill Automation: Visual Feedback Control And Rotational Motion Tracking, Jhon F. Diaz

Master's Theses

ICSI (intra-cytoplasmic sperm injection) has attracted research interest from both biological and engineering groups. The technology is constantly evolving to perform this procedure with precision and speed. One such development is the contribution of this thesis. We focus on a relatively recent procedure called Ros-Drill^© (rotationally oscillating drill), of which the early versions have already been effectively utilized for the mice. In the first part, we present a procedure to automate a critical part of the operation: initiation of the rotational oscillation, Visual feedback is used to track the pipette tip. Predetermined species-specific penetration depth is successfully utilized …

In Vivo Measurement Of Color Relationships Between The Maxillary Central Incisor And Canine As A Function Of Age, Marie E. Falcone

Master's Theses

Abstract

Introduction

It has long been taught that the basic shade (hue) of the patient can be taken from the canine (i.e. that tooth thought to have the highest chroma of a particular hue) and then that hue can be applied to other anterior teeth but at a lower chroma. However, this concept does not appear to derive from published measurements or observations. This study documented the color relationship between in vivo maxillary central incisors and canines to examine: (1) whether they share the same hue, but have different chromas (as commonly taught); and, (2) whether color differences (∆E values) …

Electrochemical Synthesis Of Single Crystal Metal Nanowires, Nan Li

Master's Theses

Electrodeposition is an efficient and economical approach for template synthesis of one-dimensional (1D) nanostructured materials. Based on the porous membranes as templates during electrodeposition, metallic nanowires, nanorods, and nanotubes can overcome the geometrical restrictions to be inserted into the nanometric recesses with both diameter and length well controlled by tuning the size and thickness of the templates.

In this work, the morphology, growth rate and texture of copper nanowires prepared with templates were investigated by the controlled parameters in various experiments. Cu nanowire arrays with preferential orientations can be successfully synthesized into the Anodic Aluminum Oxide (AAO) templates with optimized …

Temporal And Spatial Variability Of Phytoplankton Biomass In Coastal Mississippi Waters, Lorin Matthew Dornback

Master's Theses

Chlorophyll concentrations were measured in western Mississippi coastal waters to determine the spatial and temporal variability of phytoplankton. Nutrients (nitrate, silicate, phosphate), river discharge, temperature, salinity, stratification, tides, currents and winds were measured in concert with the phytoplankton concentrations. The purpose of this study was to determine the seasonal variability in phytoplankton and what was driving the variability. This study was comprised of a three year (September 2007-November 2010) time series where samples were taken once a month for eight stations. Profiles of each station were taken using a Conductivity, Temperature and Depth (CTD) sensor and a WET Labs FL-3 …