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- Genre: Masters Thesis
Description
Due to heterogeneity at the cellular level, single cell analysis (SCA) has become a necessity to study cellomics for the early detection of diseases like cancer. Development of single cell manipulation systems is very critical for performing SCA. In this thesis, electrorotation (ROT) chips to trap and rotate single cells using electrokinetic forces have been developed. The ROT chip mainly consists of a set of closely spaced metal electrodes (60µm interspacing between opposite electrodes) that forms a closed electric field cage (electrocage) when driven with high frequency AC voltages. Cells were flowed through a microchannel to the electrocage where they could be precisely trapped, levitated and rotated in 3-D along the axis of interest. The dielectrophoresis based ROT chip design and relevant electrokinetic effects have been simulated using COMSOL 3.4 to optimize the design parameters. Also, various semiconductor technology fabrication process steps have been developed and optimized for better yield and repeatability in the manufacture of the ROT chip. The ROT chip thus fabricated was used to characterize rotation of single cells with respect to the control parameters namely excitation voltage, frequency and cell line. The longevity of cell rotation under electric fields has been probed. Also, the Joule heating inside the ROT chip due to applied voltage has been characterized to know the thermal stress on the cells. The major advantages of the ROT chip developed are precise electrorotation of cells, simple design and straight forward fabrication process.
ContributorsSoundappa Elango, Iniyan (Author) / Meldrum, Deirdre R (Thesis advisor) / Christen, Jennifer Blain (Committee member) / Johnson, Roger H (Committee member) / Arizona State University (Publisher)
Created2012
Description
The effects of specific histone deacetylase inhibitors (HDACi) on transgene expression in combination with a novel polymer as a delivery vehicle are investigated in this research. Polymer vectors, although safer than viruses, are notorious for low levels of gene expression. In this investigation, the use of an emerging chemotherapeutic anti-cancer drug molecule, HDACi, was used to enhance the polymer-mediated gene expression. HDACi are capable of inhibiting deacetylation activities of histones and other non-histone proteins in the cytoplasm and nucleus, as well as increase transcriptional activities necessary for gene expression. In a prior study, a parallel synthesis and screening of polymers yielded a lead cationic polymer with high DNA-binding properties, and even more attractive, high transgene expressions. Previous studies showed the use of this polymer in conjunction with cytoplasmic HDACi significantly enhanced gene expression in PC3-PSMA prostate cancer cells. This led to the basis for the investigation presented in this thesis, but to use nuclear HDACi to potentially achieve similar results. The HDACi, HDACi_A, was a previously discovered lead drug that had potential to significantly enhance luciferase expression in PC3-PSMA cells. The results of this study found that the 20:1 polymer:plasmid DNA weight ratio was effective with 1 uM and 2 uM HDACI_A concentrations, showing up to a 9-fold enhancement. This enhancement suggested that HDACi_A was effectively aiding transfection. While not an astounding enhancement, it is still interesting enough to investigate further. Cell viabilities need to be determined to supplement the results.
ContributorsLehrman, Jennifer (Author) / Rege, Kaushal (Thesis advisor) / Caplan, Michael (Committee member) / Pizziconi, Vincent (Committee member) / Arizona State University (Publisher)
Created2012
Description
Human operators have difficulty driving cranes quickly, accurately, and safely because of the slow response of heavy crane structures, non-intuitive control interfaces, and payload oscillations. Recently, a novel hand-motion crane control system has been proposed to improve performance by coupling an intuitive control interface with an element that reduces the complex oscillatory behavior of the payload. Hand-motion control allows operators to drive a crane by simply moving a hand-held radio-frequency tag through the desired path. Real-time location sensors are used to track the movements of the tag and the tag position is used in a feedback control loop to drive the crane. An input shaper is added to eliminate dangerous payload oscillations. However, tag position measurements are corrupted by noise. It is important to understand the noise properties so that appropriate filters can be designed to mitigate the effects of noise and improve tracking accuracy. This work discusses implementing filtering techniques to address the issue of noise in the operating environment. Five different filters are used on experimentally-acquired tag trajectories to reduce noise. The filtered trajectories are then used to drive crane simulations. Filter performance is evaluated with respect to the energy usage of the crane trolley, the settling time of the crane payload oscillations, and the safety corridor of the crane trajectory. The effects of filter window lengths on these parameters are also investigated. An adaptive filtering technique, namely the Kalman filter, adapts to the noise characteristics of the workspace to minimize the tag tracking error and performs better than the other filtering techniques examined.
ContributorsRagunathan, Sudarshan (Author) / Frakes, David (Thesis advisor) / Singhose, William (Committee member) / Tillery, Stephen Helms (Committee member) / Arizona State University (Publisher)
Created2012
Description
The purpose of this study was to explore the ways in which childhood was perceived in the circuit Chautauqua movement. The methodology followed a threefold approach: first, to trace the development of the Chautauqua movement, thereby identifying the values and motivations which determined programming; next, to identify the major tropes of thought through which childhood has been traditionally understood; and finally, to do a performance analysis of the pageant America, Yesterday and Today to locate perceptions of childhood and to gain a better understanding of the purpose of this pageant. My principal argument is that the child's body was utilized as the pivotal tool for the ideological work that the pageant was designed to do. This ideological effort was aimed at both the participants and the audience, with the child's body serving as the site of education as well as signification. Through the physical embodiment and repetition of different roles, the children who participated performed certain values and cultural assumptions. This embodiment of values was expected to be retained and performed long after the performance was over - it was a form of training through pleasure.
ContributorsSchoenfelder, Joseph (Author) / Bedard, Roger (Thesis advisor) / Underiner, Tamara (Thesis advisor) / Sterling, Pamela (Committee member) / Arizona State University (Publisher)
Created2012
Description
Co-teaching is one of the most popular models for supporting students with disabilities in general education classrooms. In spite of this, there is a paucity of research on student perceptions of co-teaching. The purpose of this qualitative study was to investigate student perceptions of co-teaching in a high school biology classroom. Over nine weeks, data was collected from students in a co-taught and traditional classroom through observations and focus groups. Qualitative content analysis identified three themes and eight categories which highlight student perceptions of co-teaching. Themes and categories that emerged were: 1) Environment which included the categories of availability of help, students feeling supported and normalcy of the classroom, 2) Instruction which included student engagement, lesson activity and teacher(s) role(s) and, 3) Relationships which included relationships between teacher(s) and student(s) and parity between teachers. Information from the study deepens researchers' and practitioners' understanding of how students perceive co-teaching and provide new avenues for future research and best practices.
ContributorsLersch, Matthew (Author) / Lersch, Matthew S (Thesis advisor) / Kozleski, Elizabeth B. (Committee member) / Malian, Ida (Committee member) / Swadener, Elizabeth (Committee member) / Arizona State University (Publisher)
Created2012
Description
Research on developing new algorithms to improve information on brain functionality and structure is ongoing. Studying neural activity through dipole source localization with electroencephalography (EEG) and magnetoencephalography (MEG) sensor measurements can lead to diagnosis and treatment of a brain disorder and can also identify the area of the brain from where the disorder has originated. Designing advanced localization algorithms that can adapt to environmental changes is considered a significant shift from manual diagnosis which is based on the knowledge and observation of the doctor, to an adaptive and improved brain disorder diagnosis as these algorithms can track activities that might not be noticed by the human eye. An important consideration of these localization algorithms, however, is to try and minimize the overall power consumption in order to improve the study and treatment of brain disorders. This thesis considers the problem of estimating dynamic parameters of neural dipole sources while minimizing the system's overall power consumption; this is achieved by minimizing the number of EEG/MEG measurements sensors without a loss in estimation performance accuracy. As the EEG/MEG measurements models are related non-linearity to the dipole source locations and moments, these dynamic parameters can be estimated using sequential Monte Carlo methods such as particle filtering. Due to the large number of sensors required to record EEG/MEG Measurements for use in the particle filter, over long period recordings, a large amounts of power is required for storage and transmission. In order to reduce the overall power consumption, two methods are proposed. The first method used the predicted mean square estimation error as the performance metric under the constraint of a maximum power consumption. The performance metric of the second method uses the distance between the location of the sensors and the location estimate of the dipole source at the previous time step; this sensor scheduling scheme results in maximizing the overall signal-to-noise ratio. The performance of both methods is demonstrated using simulated data, and both methods show that they can provide good estimation results with significant reduction in the number of activated sensors at each time step.
ContributorsMichael, Stefanos (Author) / Papandreou-Suppappola, Antonia (Thesis advisor) / Chakrabarti, Chaitali (Committee member) / Kovvali, Narayan (Committee member) / Arizona State University (Publisher)
Created2012
Description
There is a tremendous need for wireless biological signals acquisition for the microelectrode-based neural interface to reduce the mechanical impacts introduced by wire-interconnects system. Long wire connections impede the ability to continuously record the neural signal for chronic application from the rodent's brain. Furthermore, connecting and/or disconnecting Omnetics interconnects often introduces mechanical stress which causes blood vessel to rupture and leads to trauma to the brain tissue. Following the initial implantation trauma, glial tissue formation around the microelectrode and may possibly lead to the microelectrode signal degradation. The aim of this project is to design, develop, and test a compact and power efficient integrated system (IS) that is able to (a) wirelessly transmit triggering signal from the computer to the signal generator which supplies voltage waveforms that move the MEMS microelectrodes, (b) wirelessly transmit neural data from the brain to the external computer, and (c) provide an electrical interface for a closed loop control to continuously move the microelectrode till a proper quality of neural signal is achieved. One of the main challenges of this project is the limited data transmission rate of the commercially available wireless system to transmit 400 kbps of digitized neural signals/electrode, which include spikes, local field potential (LFP), and noise. A commercially available Bluetooth module is only capable to transmit at a total of 115 kbps data transfer rate. The approach to this challenge is to digitize the analog neural signal with a lower accuracy ADC to lower the data rate, so that is reasonable to wirelessly transfer neural data of one channel. In addition, due to the limited space and weight bearing capability to the rodent's head, a compact and power efficient integrated system is needed to reduce the packaged volume and power consumption. 3D SoP technology has been used to stack the PCBs in a 3D form-factor, proper routing designs and techniques are implemented to reduce the electrical routing resistances and the parasitic RC delay. It is expected that this 3D design will reduce the power consumption significantly in comparison to the 2D one. The progress of this project is divided into three different phases, which can be outlined as follow: a) Design, develop, and test Bluetooth wireless system to transmit the triggering signal from the computer to the signal generator. The system is designed for three moveable microelectrodes. b) Design, develop, and test Bluetooth wireless system to wirelessly transmit an amplified (200 gain) neural signal from one single electrode to an external computer. c) Design, develop, and test a closed loop control system that continuously moves a microelectrode in searching of an acceptable quality of neural spikes. The outcome of this project can be used not only for the need of neural application but also for a wider and general applications that requires customized signal generations and wireless data transmission.
ContributorsZhou, Li (Author) / Muthuswamy, Jitendran (Thesis advisor) / Sutanto, Jemmy (Thesis advisor) / Yu, Hongyu (Committee member) / Arizona State University (Publisher)
Created2012
Description
This study gathers the expertise of three reputable art teachers, through analysis of qualitative data collected during in-person interviews and classroom observations, as they share their experiences and insights regarding successful methods of motivating and engaging students in their beginning-level art classes. Various works of literature regarding educational motivation are reviewed, and this study begins to address the need for additional research involving this issue, as it applies to teachers of art. Commonalities between the motivational tactics of the participating teachers are discussed, as well as comparison of findings to existing literature. This may be useful to art teachers who are new to the field or who are seeking information regarding successful methods of encouraging motivation and engagement in their beginning -level art classes.
ContributorsClark, Erica (Author) / Young, Bernard (Thesis advisor) / Erickson, Mary (Committee member) / Stokrocki, Mary (Committee member) / Arizona State University (Publisher)
Created2012
Description
The world of healthcare can be seen as dynamic, often an area where technology and science meet to consummate a greater good for humanity. This relationship has been working well for the last century as evident by the average life expectancy change. For the greater of the last five decades the average life expectancy at birth increased globally by almost 20 years. In the United States specifically, life expectancy has grown from 50 years in 1900 to 78 years in 2009. That is a 76% increase in just over a century. As great as this increase sounds for humanity it means there are soon to be real issues in the healthcare world. A larger older population will need more healthcare services but have fewer young professionals to provide those services. Technology and science will need to continue to push the boundaries in order to develop and provide the solutions needed to continue providing the aging world population sufficient healthcare. One solution sure to help provide a brighter future for healthcare is mobile health (m-health). M-health can help provide a means for healthcare professionals to treat more patients with less work expenditure and do so with more personalized healthcare advice which will lead to better treatments. This paper discusses one area of m-health devices specifically; human breath analysis devices. The current laboratory methods of breath analysis and why these methods are not adequate for common healthcare practices will be discussed in more detail. Then more specifically, mobile breath analysis devices are discussed. The topic will encompass the challenges that need to be met in developing such devices, possible solutions to these challenges, two real examples of mobile breath analysis devices and finally possible future directions for m-health technologies.
ContributorsLester, Bryan (Author) / Forzani, Erica (Thesis advisor) / Xian, Xiaojun (Committee member) / Trimble, Steve (Committee member) / Arizona State University (Publisher)
Created2012
Description
Development of post-traumatic epilepsy (PTE) after traumatic brain injury (TBI) is a major health concern (5% - 50% of TBI cases). A significant problem in TBI management is the inability to predict which patients will develop PTE. Such prediction, followed by timely treatment, could be highly beneficial to TBI patients. Six male Sprague-Dawley rats were subjected to a controlled cortical impact (CCI). A 6mm piston was pneumatically driven 3mm into the right parietal cortex with velocity of 5.5m/s. The rats were subsequently implanted with 6 intracranial electroencephalographic (EEG) electrodes. Long-term (14-week) continuous EEG recordings were conducted. Using linear (coherence) and non-linear (Lyapunov exponents) measures of EEG dynamics in conjunction with measures of network connectivity, we studied the evolution over time of the functional connectivity between brain sites in order to identify early precursors of development of epilepsy. Four of the six TBI rats developed PTE 6 to 10 weeks after the initial insult to the brain. Analysis of the continuous EEG from these rats showed a gradual increase of the connectivity between critical brain sites in terms of their EEG dynamics, starting at least 2 weeks prior to their first spontaneous seizure. In contrast, for the rats that did not develop epilepsy, connectivity levels did not change, or decreased during the whole course of the experiment across pairs of brain sites. Consistent behavior of functional connectivity changes between brain sites and the "focus" (site of impact) over time was demonstrated for coherence in three out of the four epileptic and in both non-epileptic rats, while for STLmax in all four epileptic and in both non-epileptic rats. This study provided us with the opportunity to quantitatively investigate several aspects of epileptogenesis following traumatic brain injury. Our results strongly support a network pathology that worsens with time. It is conceivable that the observed changes in spatiotemporal dynamics after an initial brain insult, and long before the development of epilepsy, could constitute a basis for predictors of epileptogenesis in TBI patients.
ContributorsTobin, Edward (Author) / Iasemidis, Leonidas (Thesis advisor) / Tsakalis, Konstantinos (Committee member) / Muthuswamy, Jitendran (Committee member) / Arizona State University (Publisher)
Created2012