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2012

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Memristor-Based Reservoir Computing, Manjari S. Kulkarni Jan 2012

Memristor-Based Reservoir Computing, Manjari S. Kulkarni

Dissertations and Theses

In today's nanoscale era, scaling down to even smaller feature sizes poses a significant challenge in the device fabrication, the circuit, and the system design and integration. On the other hand, nanoscale technology has also led to novel materials and devices with unique properties. The memristor is one such emergent nanoscale device that exhibits non-linear current-voltage characteristics and has an inherent memory property, i.e., its current state depends on the past. Both the non-linear and the memory property of memristors have the potential to enable solving spatial and temporal pattern recognition tasks in radically different ways from traditional binary transistor-based …

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Biological Treatment Of Leachates Of Microaerobic Fermentation, Manar Arica Alattar Jan 2012

Biological Treatment Of Leachates Of Microaerobic Fermentation, Manar Arica Alattar

Dissertations and Theses

Microaerobic fermentation (MF) is a process of controlled degradation of organic waste material that occurs in enclosed fermentors under micro-aerobic conditions at near-room temperature. MF processing of vegetal materials progresses to endpoints in about 2-5 weeks. During MF processing, an acidic leachate rich in organic acids and alcohols is produced. The research presented in this thesis focuses on the efficiency of MF pre-processing of feedstock containing fibrous lignocellulosic (FLC) materials; efficiency of microbial and insect larvae-based treatments of MF leachate; tolerance of the Black Soldier fly larvae (BSFL) to various biological inhibitors common in leachate; and effectiveness of using MF …

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Development Of A Nephelometry Camera And Humidity Controlled Cavity Ring-Down Transmissometer For The Measurement Of Aerosol Optical Properties, James Gregory Radney Jan 2012

Development Of A Nephelometry Camera And Humidity Controlled Cavity Ring-Down Transmissometer For The Measurement Of Aerosol Optical Properties, James Gregory Radney

Dissertations and Theses

A Nephelometry camera (NephCam) and Humidity Controlled Cavity Ring-Down Transmissometer (HC-CRDT) were developed for the determination of aerosol optical properties. The NephCams use a reciprocal geometry relative to an integrating nephelometer; a diode laser illuminates a scattering volume orthogonal to a charge coupled device (CCD). The use of a CCD allows for measurement of aerosol scattering in 2 dimensions; scattering coefficients and size information can be extracted. The NephCam's optics were characterized during a set of imaging experiments to optimize the images collected by the camera. An aperture setting of 1.6 was chosen because it allowed for the most light …

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Relative Heart Ventricle Mass And Cardiac Performance In Amphibians, Gregory Joseph Kluthe Jan 2012

Relative Heart Ventricle Mass And Cardiac Performance In Amphibians, Gregory Joseph Kluthe

Dissertations and Theses

This study used an in situ heart preparation to analyze the power and work of spontaneously beating hearts of four anurans (R. marina, L. catesbeianus, X. laevis, P. edulis) and three urodeles (N. maculosus, A. tigrinum, A. tridactylum) in order to elucidate the meaning of relative ventricle mass (RVM) in terms of specific cardiac performance variables. This study also tests two hypotheses: 1) the ventricles of terrestrial species (R. marina, P. edulis, A. tigrinum) of amphibians are capable of greater maximum power outputs (Pmax) compared to aquatic species (X. laevis, A. tridactylum, N. maculosus, L. catesbeianus) and, 2) …

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Causes And Consequences Of Mitochondrial Variation In Caenorhabditid Nematodes, Kiley Ann Hicks Jan 2012

Causes And Consequences Of Mitochondrial Variation In Caenorhabditid Nematodes, Kiley Ann Hicks

Dissertations and Theses

Mitochondria are dynamic organelles that harbor their own stream-lined genome and generate much of the ATP necessary to sustain eukaryotic life via an electron transport chain (ETC). Because of the central role for mitochondria in organismal physiology, mitochondrial genetic and phenotypic variation can alter organismal fitness and affect population genetic and evolutionary outcomes. Despite the far-reaching relevance of mitochondria to evolutionary processes and human health, we lack a basic understanding of the causes and consequences of mitochondrial genetic and phenotypic variation. In this thesis, I quantified mitochondrial reactive oxygen species (ROS), membrane potential (δΨM), and mitochondrial morphological traits within Caenorhabditis …

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Biosynthesis Of Marineosin, A Spiroaminal Undecylprodiginine Natural Product, Shaimaa Mohamed Salem Jan 2012

Biosynthesis Of Marineosin, A Spiroaminal Undecylprodiginine Natural Product, Shaimaa Mohamed Salem

Dissertations and Theses

Marineosins A and B are two spiroaminal-ring containing tripyrrole compounds isolated from the marine actinomycete, Streptomyces CNQ-617, and were found to possess potent and selective cytotoxic activity against leukemia and melanoma. Marineosins belong to the prodiginines class of natural products, examples of which are undecylprodiginine and streptorubin B. Unlike marineosins, prodiginines structures are characterized by the presence of fully conjugated tripyrrole nucleus linked to an alkyl chain (that lacks any oxygen). Cyclic prodiginines arise from an oxidative cyclization of the alkyl chain onto the tripyrrole, a step catalyzed by Rieske-oxygenase like enzymes such as RedG. The biosynthesis of prodiginines is …

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Investigation Of Impedance Spectroscopy For Detection Of Ovarian Cancer, Allison Mae Whited Jan 2012

Investigation Of Impedance Spectroscopy For Detection Of Ovarian Cancer, Allison Mae Whited

Dissertations and Theses

Electronic biosensors utilizing micron-scale interdigitate electrodes (IDEs) in an SD card format have been developed with the objective of fast, sensitive detection of ovarian cancer biomarkers CA-125, CEA, and He4. The signal generated by the biosensors is a result of electrochemical impedance spectroscopy (EIS), a technique which probes changes that occur in the biosensor's electrical properties when the biosensor has detected one of the target biomarkers. A label-free biosensor has been developed to detect CA-125 in spiked buffer at concentrations between 10 and 80units/mL. A similar label-free biosensor was developed to detect CEA at concentrations between 10ug/mL and 10mg/mL. A …

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Differential Susceptibility To Social Network Influences On School Motivation In A Cohort Of Sixth Graders, Justin William Vollet Jan 2012

Differential Susceptibility To Social Network Influences On School Motivation In A Cohort Of Sixth Graders, Justin William Vollet

Dissertations and Theses

Students' classroom engagement is a strong predictor of positive educational outcomes including academic achievement, GPA, and standardized test scores. Most existing research has focused on the role of quality parenting and teaching in the development of student engagement. However, some research has shown small, yet significant effects of influences from students' peer groups on the development of their engagement. The goal of this study was to explore whether some children are more susceptible to the effects of their peer groups, and to examine a series of possible factors that might amplify the influence of a target students peer group on …

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Digital Fabric, Sudheer Goshi Jan 2012

Digital Fabric, Sudheer Goshi

Dissertations and Theses

Continuing advances with VLSI have enabled engineers to build high performance computer systems to solve complex problems. The real-world problems and tasks like pattern recognition, speech recognition, etc. still remain elusive to the most advanced computer systems today. Many advances in the science of computer design and technology are coming together to enable the creation of the next-generation computing machines to solve real-world problems, which the human brain does with ease. One such engineering advance is the field of neuromorphic engineering, which tries to establish closer links to biology and help us investigate the problem of designing better computing machines. …

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The Effects Of Temperature On The Dispersion And Reaggregation Stages Of Development In The Annual Killifish, Austrofundulus Limnaeus, Timothy Grant Cleaver Jan 2012

The Effects Of Temperature On The Dispersion And Reaggregation Stages Of Development In The Annual Killifish, Austrofundulus Limnaeus, Timothy Grant Cleaver

Dissertations and Theses

The dispersion and reaggreation [sic] stages have been described as a unique feature of embryonic development in annual killifish such as Austrofundulus limnaeus, a killifish that inhabits ephemeral ponds in the Maracaibo basin of Venezuela. These stages have previously been described as an atypical developmental progression in which blastomeres completely disperse on the surface of the yolk and then reaggregate into a mass of cells to form the embryo. Temperature affects the onset as well as the duration of this stage in related annual fishes. We have undertaken this study to show in detail the behavior of blastomere cells and …

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A Qualitative Study Of Language Beliefs And Linguistic Knowledge In Preservice Teachers Using The Intercultural Communicative Competence Framework, Kimberly K. Ilosvay Jan 2012

A Qualitative Study Of Language Beliefs And Linguistic Knowledge In Preservice Teachers Using The Intercultural Communicative Competence Framework, Kimberly K. Ilosvay

Dissertations and Theses

Since 1980, the number of people in the United States who speak a language other than English at home has increased by 140% (United States Census Bureau, 2010). Therefore a greater percentage of students now are multilingual. Throughout the world, multilingualism is considered the norm and monolingualism is the exception (Auer & Wei, 2008). In the United States, however, policies regarding instruction in schools are still influenced by monolingual ideology that carries expectations and assumptions of assimilation, loss of mother tongues, and defined hierarchical structures. As classroom populations become socially, ethnically, racially, and linguistically more diverse, it is increasingly important …

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Conscientiousness As A Moderator Of The Relationship Between Work Autonomy And Job Satisfaction, Kyle Garret Mack Jan 2012

Conscientiousness As A Moderator Of The Relationship Between Work Autonomy And Job Satisfaction, Kyle Garret Mack

Dissertations and Theses

Autonomy is one of the most commonly studied job characteristics in the work design literature and is commonly associated with large and positive effects on job satisfaction. There is reason to believe that autonomy may interact with personality characteristics to affect attitudinal outcomes, but prior research has tended to focus on the original growth-need-strength construct as a potential moderator with mixed results. One glaring gap in the literature is the lack of research that examines the Big Five constructs of personality as a potential class of moderators. Grant, Fried, and Juillerat (2010) have suggested additional research into the Big Five …

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Fluorescent Indicators For Disease Biomarkers, Soojin Lim Jan 2012

Fluorescent Indicators For Disease Biomarkers, Soojin Lim

Dissertations and Theses

Xanthene dyes are common fluorophores which have been widely used as molecular probes. The xanthene fluorophores can be used as highly selective optical sensors to detect disease biomarkers. A new fluorogenic dye containing an alpha, beta-unsaturated aldehyde moiety exhibits selective fluorescent signal enhancement in the presence of cysteine or peptides containing N-terminal cysteine residues. The mechanism is based on synergistic covalent and supramolecular interactions. A unique rhodamine boronic acid indicator is used in an optimized data collection protocol for wavelength- and time-dependent selectivity of various saccharides and nucleosides. One indicator is thereby capable of selectively distinguishing structurally related analytes in …

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Public Participation In Emergency Management, Jason Alexander Rood Jan 2012

Public Participation In Emergency Management, Jason Alexander Rood

Dissertations and Theses

With disasters increasing in frequency and costs each year, this study seeks to explore ways greater public participation can assist emergency managers in their mission to keep communities safe. Specifically this study examines the policy process and administrative functions of emergency management to illuminated the benefits and hindrances involved in greater participation. This study conducted a qualitative analysis of governmental documents, disaster case studies, international research, as well as political science and administrative doctrines, to arrive at its conclusions. The results of this study reveal that the public is a largely untapped resource in the emergency management field. Engaging the …

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Insight Into The Reactivity Of Metastasis Inhibitor, Imidazolium Trans-[Tetrachloro (Dimethyl Sulfoxide)(Imidazole)Ruthenate(Iii)], With Biologically-Active Thiols, Risikat Ajibola Adigun Jan 2012

Insight Into The Reactivity Of Metastasis Inhibitor, Imidazolium Trans-[Tetrachloro (Dimethyl Sulfoxide)(Imidazole)Ruthenate(Iii)], With Biologically-Active Thiols, Risikat Ajibola Adigun

Dissertations and Theses

Imidazolium trans-[tetrachloro (dimethyl sulfoxide)(imidazole)ruthenate(III)], NAMI-A, is an experimental metastasis inhibitor whose specific mechanism of activation and action remains to be elucidated. In the nucleophilic and reducing physiological environment; it is anticipated that the most relevant and available reductants upon introduction of NAMI-A as a therapeutic agent will be the biologically-relevant free thiols. The kinetics and mechanisms of interaction of NAMI-A with biologically-active thiols cysteamine, glutathione, cysteine and a popular chemoprotectant, 2-mercaptoethane sulfonate (MESNA) have been studied spectrophotometrically under physiologically-relevant conditions. The reactions are characterized by initial reduction of NAMI-A with simultaneous formation of dimeric thiol and subsequent ligand exchange with …

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Understanding The Emission From Semiconductor Nanoparticles, Beth Ann Manhat Jan 2012

Understanding The Emission From Semiconductor Nanoparticles, Beth Ann Manhat

Dissertations and Theses

This dissertation describes the synthesis and characterization of fluorescent semiconductor nanoparticles (NPs) in order to optimize their biomedical utility for imaging and sensing applications. While both direct and indirect bandgap semiconductor NPs have been studied, control over their emission properties vary. Quantum confinement (QC), which primarily controls the emission wavelength of nanosized semiconductors, dictates that as the size of semiconductor NPs decrease, the magnitude of the bandgap increases, resulting in changes in the observed emission wavelength: smaller NPs have a larger bandgap, and thus a bluer emission. However, surface, interfacial, or shell defects can act as non-radiative or radiative recombination …

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Shaping The Future Past: Finding History, Creating Identity In The Kwan Hsu Papers, Lisa Chere' Donnelly Jan 2012

Shaping The Future Past: Finding History, Creating Identity In The Kwan Hsu Papers, Lisa Chere' Donnelly

Dissertations and Theses

Dr. Kwan Hsu was neither a superstar nor a celebrity. Her name does not come up in conversations about important contributors to her field of biophysics nor is she instantly recognizable for her contributions to Portland State University's international program or the state of Oregon's business ties with China. Yet she was a contributor, a cog-in-the-wheel, at the very least, in all of these areas and more. She was a peripheral member of a well-known Chinese family, but few in the United States know of or perhaps have interest in, but otherwise, she had no great connections or family ties …

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Silk Cryogels For Microfluidics, Christopher David Hinojosa Jan 2012

Silk Cryogels For Microfluidics, Christopher David Hinojosa

Dissertations and Theses

Silk fibroin from silkworm cocoons is found in numerous applications ranging from textiles to medical implants. Its recent adoption as a biomaterial is due to the material's strength, biocompatibility, self-assembling behavior, programmable degradability, optical clarity, and its ability to be functionalized with antibodies and proteins. In the field of bioengineering it has been utilized as a tissue scaffolding, drug delivery system, biosensor, and implantable electrode. This work suggests a new application for porous silk in a microscale chromatography column. We demonstrate in situ cryotropic polymerization of highly porous structures in microscale geometries by freezing aqueous silk with a solvent. The …

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Understanding Sand Mining On The Maha Oya: The Conflict Between Economic And Environmental Survival, Meredith Corea Talbert Jan 2012

Understanding Sand Mining On The Maha Oya: The Conflict Between Economic And Environmental Survival, Meredith Corea Talbert

Dissertations and Theses

River sand mining from the Maha Oya is the main source of income and a force that drives economic activity for residents along the river. This study takes place in Sri Lanka, there are three villages included in this project: Jambugaswatte, Janituspuraya and Thoppuwa. In Sri Lanka, sand serves as the main building material. It is used to make bricks, tiles, asphalt and concrete, therefore demanding a high market value. However, the over-extraction of sand comes along with significant environmental problems. These communities depend on the river in many ways and the health of the river directly corresponds to the …

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A Systems Approach To Ecological Economic Models Developed Progressively In Three Interwoven Articles, Takuro Uehara Jan 2012

A Systems Approach To Ecological Economic Models Developed Progressively In Three Interwoven Articles, Takuro Uehara

Dissertations and Theses

My dissertation develops and analyzes ecological economic models to study the complex dynamics of an ecological economic system (EES) and investigate various conditions and measures which can sustain a developing economy over the long term in view of resilience and sustainability. Because of the intrinsic complexity of the system, I take a systems approach, using economics as the foundation for the basic structure of an ecological economic model, and system dynamics as the method to build and analyze such a complex ecological economic model. Throughout my dissertation, the model developed by Brander and Taylor (1998) is adopted as a baseline …

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Electronic Properties And Structure Of Functionalized Graphene, Pavel Plachinda Jan 2012

Electronic Properties And Structure Of Functionalized Graphene, Pavel Plachinda

Dissertations and Theses

The trend over the last 50 years of down-scaling the silicon transistor to achieve faster computations has led to doubling of the number of transistors and computation speed over about every two years. However, this trend cannot be maintained due to the fundamental limitations of silicon as the main material for the semiconducting industry. Therefore, there is an active search for exploration of alternate materials. Among the possible candidates that can may [sic] be able to replace silicon is graphene which has recently gained the most attention. Unique properties of graphene include exceedingly high carrier mobility, tunable band gap, huge …

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Metabolic Support Of Anaerobiosis In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Andrew Mccracken Jan 2012

Metabolic Support Of Anaerobiosis In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Andrew Mccracken

Dissertations and Theses

Embryos of the annual killifish Austrofundulus limnaeus display a remarkable tolerance to anoxia during development, most notably during embryonic diapause. Little is known about the metabolic or enzymatic changes that accompany this state of anoxia tolerance. This study examined the metabolic changes associated with exposure to anoxia by measuring the activity of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), and by profiling the concentration of 31 metabolites ranging from amino acids to citric cycle intermediates at 4 different developmental stages, diapause 2 (DII), 4 days post diapause (dpd), 12 and 22 dpd. Embryos of A. limnaeus showed stage specific changes in concentrations …

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Oral Health Knowledge, Attitudes, And Behaviors: Investigation Of An Educational Intervention Strategy With At-Risk Females, Susan Romano Rustvold Jan 2012

Oral Health Knowledge, Attitudes, And Behaviors: Investigation Of An Educational Intervention Strategy With At-Risk Females, Susan Romano Rustvold

Dissertations and Theses

A self-perpetuating cycle of poor health literacy and poor oral health knowledge and behavior affects approximately 90 million people in the United States, most especially those from low-income groups and other at-risk populations such as those with addiction. Poor oral health can result from lack of access to regular preventive dental appointments, lack of access to restorative care when dental diseases are treatable, and low oral health knowledge that leads to poor oral health self-care behaviors. In addition, patients' dental anxiety can impede care, because highly anxious people often avoid dental appointments. To address these issues, this inquiry examined oral …

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Social Job Characteristics And Older Workers: Effects On Job Satisfaction And Job Tension, Jennifer Rae Rineer Jan 2012

Social Job Characteristics And Older Workers: Effects On Job Satisfaction And Job Tension, Jennifer Rae Rineer

Dissertations and Theses

The workforce in most industrialized countries is aging and becoming more age diverse, but few studies have examined the implications of age differences in the design of jobs. This study examined the role of age as a moderator in the relationship between job characteristics and two individual outcomes, job satisfaction and job tension. Specifically, the study focused on the relationship between social characteristics of the job (given social support, [received] social support, interdependence, interaction outside the organization, and feedback from others) and job tension and job satisfaction among Portland Water Bureau employees. Based in Socioemotional Selectivity (SES) theory (Carstensen, 1991), …

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Exploring Support Network Structure, Content, And Stability As Youth Transition From Foster Care, Jennifer E. Blakeslee Jan 2012

Exploring Support Network Structure, Content, And Stability As Youth Transition From Foster Care, Jennifer E. Blakeslee

Dissertations and Theses

Many older youth in foster care lack adequate resources and ongoing support in their social networks as they transition into young adulthood, while other youth in these circumstances experience stable social networks providing comprehensive support. Systematically measuring the supportive personal and service-oriented relationships in youth networks expands the scope of inquiry in this area by identifying patterns of social network structure, member composition, and relational qualities that are associated with more or less support provision through formal and informal relationships. These can also be measured over time to observe changes in network form and content and assess network stability. This …

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Understanding The Experience Of Air Force Single Parents: A Phenomenological Study, Samantha Everhart Blanchard Jan 2012

Understanding The Experience Of Air Force Single Parents: A Phenomenological Study, Samantha Everhart Blanchard

Dissertations and Theses

Today, raising children under the best of circumstances represents a daunting endeavor as any parent and a growing body of research confirm. When a single parent is on active duty in one of the U.S. armed forces, there are additional challenges involved that may not exist among civilian counterparts. The phenomenon of single parents on active duty with its unique difficulties associated both with single parenting and with military service was the basis of this study. The purpose of the research was twofold: to describe the experiences of Air Force single parents as related to social support and work-life theory …

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Involvement In The Online Autistic Community, Identity, Community, And Well-Being, Colleen Anne Kidney Jan 2012

Involvement In The Online Autistic Community, Identity, Community, And Well-Being, Colleen Anne Kidney

Dissertations and Theses

The values of the disability rights movement and community psychology promote research that focuses on improving the lives of individuals with disabilities (Dowrick & Keys, 2001). Using the Internet for social interactions has been shown to contribute to an individual's identity development, sense of community, and well-being (Obst, Zinkiewicz, & Smith, 2002a; Turkle, 1995). While challenges in typical social interactions have traditionally been considered a defining feature of autism spectrum disorder, autistic individuals have taken advantage of the Internet to develop social interactions (Blume, 1997a). The present study focused on the online Autistic community and how the importance and value …

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Scale Invariant Object Recognition Using Cortical Computational Models And A Robotic Platform, Danny Voils Jan 2012

Scale Invariant Object Recognition Using Cortical Computational Models And A Robotic Platform, Danny Voils

Dissertations and Theses

This paper proposes an end-to-end, scale invariant, visual object recognition system, composed of computational components that mimic the cortex in the brain. The system uses a two stage process. The first stage is a filter that extracts scale invariant features from the visual field. The second stage uses inference based spacio-temporal analysis of these features to identify objects in the visual field. The proposed model combines Numenta's Hierarchical Temporal Memory (HTM), with HMAX developed by MIT's Brain and Cognitive Science Department. While these two biologically inspired paradigms are based on what is known about the visual cortex, HTM and HMAX …

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Designing New Drugs To Treat Cardiac Arrhythmia, Yanping Ye Jan 2012

Designing New Drugs To Treat Cardiac Arrhythmia, Yanping Ye

Dissertations and Theses

Heart failure resulting from different forms of cardiomyopathy is defined as the inability of the heart to pump sufficient blood to meet the body's metabolic demands. It is a major disease burden worldwide and the statistics show that 50% of the people who have the heart failure will eventually die from sudden cardiac death (SCD) associated with an arrhythmia. The central cause of disability and SCD is because of ventricular arrhythmias. Genetic mutations and acquired modifications to RyR2, the calcium release channel from sarcoplasmic reticulum, can increase the pathologic SR Ca2+ leak during diastole, which leads to defects in SR …

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Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah Jan 2012

Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah

Dissertations and Theses

We report on the fundamental properties and device applications of semiconductor nanoparticles. ZnO nanowires and CdSe quantum dots were used, prepared, characterized, and assembled into novel light-emitting diodes and solar cells. ZnO nanowire films were grown electrochemically using aqueous soluble chloride-based electrolytes as precursors at temperatures below 90° C. Dopants were added to the electrolyte in the form of chloride compounds, which are AlCl3, CoCl2, CuCl2, and MnCl2. The optical, magnetic, and structural properties of undoped and transition-metal-ion doped ZnO nanowires were explored. Our results indicate that the as-grown nanowire structures have …

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