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Description
In an effort to understand and improve interactions between homeless young adults and the nonprofit organizations that serve them, I engaged in a long-term, qualitative, participatory action project. My project involved input from homeless young adults, nonprofit organizations, volunteers/staff, and communication scholarship. While taking a community-engaged, participatory, and qualitative approach, I focused on the interactions between youth and the organizations. Particularly, I drew on homeless young adult experiences to inform services and illuminate compassion within the context of the nonprofit organizations. In the end, this project extends the individual model of compassion to include presence, identifies potential ruptures in the process of compassion, and models compassionate dynamics in organizations. It also articulates a method I call pragmatic fieldwork, a qualitative and pragmatic approach to participatory action research. Each of these outcomes speaks to varied community interests, from theoretically nuancing scholarly models of compassion to informing policy in the interest of more effectively and compassionately serving homeless youth.
ContributorsHuffman, Timothy (Author) / Trethewey, Angela (Thesis advisor) / Tracy, Sarah J. (Committee member) / Hagar, Mark (Committee member) / Arizona State University (Publisher)
Created2013
Description
Electrical neural activity detection and tracking have many applications in medical research and brain computer interface technologies. In this thesis, we focus on the development of advanced signal processing algorithms to track neural activity and on the mapping of these algorithms onto hardware to enable real-time tracking. At the heart of these algorithms is particle filtering (PF), a sequential Monte Carlo technique used to estimate the unknown parameters of dynamic systems. First, we analyze the bottlenecks in existing PF algorithms, and we propose a new parallel PF (PPF) algorithm based on the independent Metropolis-Hastings (IMH) algorithm. We show that the proposed PPF-IMH algorithm improves the root mean-squared error (RMSE) estimation performance, and we demonstrate that a parallel implementation of the algorithm results in significant reduction in inter-processor communication. We apply our implementation on a Xilinx Virtex-5 field programmable gate array (FPGA) platform to demonstrate that, for a one-dimensional problem, the PPF-IMH architecture with four processing elements and 1,000 particles can process input samples at 170 kHz by using less than 5% FPGA resources. We also apply the proposed PPF-IMH to waveform-agile sensing to achieve real-time tracking of dynamic targets with high RMSE tracking performance. We next integrate the PPF-IMH algorithm to track the dynamic parameters in neural sensing when the number of neural dipole sources is known. We analyze the computational complexity of a PF based method and propose the use of multiple particle filtering (MPF) to reduce the complexity. We demonstrate the improved performance of MPF using numerical simulations with both synthetic and real data. We also propose an FPGA implementation of the MPF algorithm and show that the implementation supports real-time tracking. For the more realistic scenario of automatically estimating an unknown number of time-varying neural dipole sources, we propose a new approach based on the probability hypothesis density filtering (PHDF) algorithm. The PHDF is implemented using particle filtering (PF-PHDF), and it is applied in a closed-loop to first estimate the number of dipole sources and then their corresponding amplitude, location and orientation parameters. We demonstrate the improved tracking performance of the proposed PF-PHDF algorithm and map it onto a Xilinx Virtex-5 FPGA platform to show its real-time implementation potential. Finally, we propose the use of sensor scheduling and compressive sensing techniques to reduce the number of active sensors, and thus overall power consumption, of electroencephalography (EEG) systems. We propose an efficient sensor scheduling algorithm which adaptively configures EEG sensors at each measurement time interval to reduce the number of sensors needed for accurate tracking. We combine the sensor scheduling method with PF-PHDF and implement the system on an FPGA platform to achieve real-time tracking. We also investigate the sparsity of EEG signals and integrate compressive sensing with PF to estimate neural activity. Simulation results show that both sensor scheduling and compressive sensing based methods achieve comparable tracking performance with significantly reduced number of sensors.
ContributorsMiao, Lifeng (Author) / Chakrabarti, Chaitali (Thesis advisor) / Papandreou-Suppappola, Antonia (Thesis advisor) / Zhang, Junshan (Committee member) / Bliss, Daniel (Committee member) / Kovvali, Narayan (Committee member) / Arizona State University (Publisher)
Created2013
Description
Humans' ability to perform fine object and tool manipulation is a defining feature of their sensorimotor repertoire. How the central nervous system builds and maintains internal representations of such skilled hand-object interactions has attracted significant attention over the past three decades. Nevertheless, two major gaps exist: a) how digit positions and forces are coordinated during natural manipulation tasks, and b) what mechanisms underlie the formation and retention of internal representations of dexterous manipulation. This dissertation addresses these two questions through five experiments that are based on novel grip devices and experimental protocols. It was found that high-level representation of manipulation tasks can be learned in an effector-independent fashion. Specifically, when challenged by trial-to-trial variability in finger positions or using digits that were not previously engaged in learning the task, subjects could adjust finger forces to compensate for this variability, thus leading to consistent task performance. The results from a follow-up experiment conducted in a virtual reality environment indicate that haptic feedback is sufficient to implement the above coordination between digit position and forces. However, it was also found that the generalizability of a learned manipulation is limited across tasks. Specifically, when subjects learned to manipulate the same object across different contexts that require different motor output, interference was found at the time of switching contexts. Data from additional studies provide evidence for parallel learning processes, which are characterized by different rates of decay and learning. These experiments have provided important insight into the neural mechanisms underlying learning and control of object manipulation. The present findings have potential biomedical applications including brain-machine interfaces, rehabilitation of hand function, and prosthetics.
ContributorsFu, Qiushi (Author) / Santello, Marco (Thesis advisor) / Helms Tillery, Stephen (Committee member) / Buneo, Christopher (Committee member) / Santos, Veronica (Committee member) / Artemiadis, Panagiotis (Committee member) / Arizona State University (Publisher)
Created2013
Description
Reaching movements are subject to noise in both the planning and execution phases of movement production. Although the effects of these noise sources in estimating and/or controlling endpoint position have been examined in many studies, the independent effects of limb configuration on endpoint variability have been largely ignored. The present study investigated the effects of arm configuration on the interaction between planning noise and execution noise. Subjects performed reaching movements to three targets located in a frontal plane. At the starting position, subjects matched one of two desired arm configuration 'templates' namely "adducted" and "abducted". These arm configurations were obtained by rotations along the shoulder-hand axis, thereby maintaining endpoint position. Visual feedback of the hand was varied from trial to trial, thereby increasing uncertainty in movement planning and execution. It was hypothesized that 1) pattern of endpoint variability would be dependent on arm configuration and 2) that these differences would be most apparent in conditions without visual feedback. It was found that there were differences in endpoint variability between arm configurations in both visual conditions, but these differences were much larger when visual feedback was withheld. The overall results suggest that patterns of endpoint variability are highly dependent on arm configuration, particularly in the absence of visual feedback. This suggests that in the presence of vision, movement planning in 3D space is performed using coordinates that are largely arm configuration independent (i.e. extrinsic coordinates). In contrast, in the absence of vision, movement planning in 3D space reflects a substantial contribution of intrinsic coordinates.
ContributorsLakshmi Narayanan, Kishor (Author) / Buneo, Christopher (Thesis advisor) / Santello, Marco (Committee member) / Helms Tillery, Stephen (Committee member) / Arizona State University (Publisher)
Created2013
Description
The purpose of this dissertation was to develop a Compassionate Communication Scale (CCS) by conducting a series of studies. The first study used qualitative data to identify and develop initial scale items. A series of follow-up studies used exploratory factor analysis to investigate the underlying structure of the CCS. A three-factor structure emerged, which included: Compassionate conversation, such as listening, letting the distressed person disclose feelings, and making empathetic remarks; compassionate touch, such as holding someone's hand or patting someone's back; and compassionate messaging, such as posting an encouraging message on a social networking site or sending a sympathetic email. The next study tested convergent and divergent validity by determining how the three forms of compassionate communication associate with various traits. Compassionate conversation was positively related to compassion, empathetic concern, perspective taking, emotional intelligence, social expressivity, emotional expressivity and benevolence, and negatively related to verbal aggressiveness and narcissism. Compassionate touch was positively correlated with compassion, empathetic concern, perspective taking, emotional intelligence, social expressivity, emotional expressivity, and benevolence, and uncorrelated with verbal aggressiveness and benevolence. Finally, compassionate messaging was positively correlated with social expressivity, emotional expressivity, and uncorrelated with verbal aggressiveness and narcissism. The next study focused on cross-validation and criterion-related validity. Correlations showing that self-reports of a person's compassionate communication were positively related to a friend or romantic partner's report of that person's compassionate communication provided cross-validation. The test for criterion-related validity examined whether compassionate communication predicts relational satisfaction. Regression analyses revealed that people were more relationally satisfied when they perceived themselves to use compassionate conversation, when they perceived their partner to use compassionate conversation, and when their partner reported using compassionate conversation. This finding did not extend to compassionate touch or compassionate messaging. In fact, in one regression analysis, people reported more relational satisfaction when they perceived that their partners used high levels of compassionate conversation and low levels of compassionate touch. Overall, the analyses suggest that of the three forms of compassionate communication, compassionate conversation is most strongly related to relational satisfaction. Taken together, this series of studies provides initial evidence for the validity of the CCS.
ContributorsRamos Salazar, Leslie (Author) / Guerrero, Laura (Thesis advisor) / Roberto, Anthony (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2013
Description
Image resolution limits the extent to which zooming enhances clarity, restricts the size digital photographs can be printed at, and, in the context of medical images, can prevent a diagnosis. Interpolation is the supplementing of known data with estimated values based on a function or model involving some or all of the known samples. The selection of the contributing data points and the specifics of how they are used to define the interpolated values influences how effectively the interpolation algorithm is able to estimate the underlying, continuous signal. The main contributions of this dissertation are three fold: 1) Reframing edge-directed interpolation of a single image as an intensity-based registration problem. 2) Providing an analytical framework for intensity-based registration using control grid constraints. 3) Quantitative assessment of the new, single-image enlargement algorithm based on analytical intensity-based registration. In addition to single image resizing, the new methods and analytical approaches were extended to address a wide range of applications including volumetric (multi-slice) image interpolation, video deinterlacing, motion detection, and atmospheric distortion correction. Overall, the new approaches generate results that more accurately reflect the underlying signals than less computationally demanding approaches and with lower processing requirements and fewer restrictions than methods with comparable accuracy.
ContributorsZwart, Christine M. (Author) / Frakes, David H (Thesis advisor) / Karam, Lina (Committee member) / Kodibagkar, Vikram (Committee member) / Spanias, Andreas (Committee member) / Towe, Bruce (Committee member) / Arizona State University (Publisher)
Created2013
Description
The object of this study is to charac terize the effect of focused ultrasound stimulation (FUS) on the rat ce rvix which has been observed to speed its ripening during pregnancy. Ce rvical ripening is required for successful fetal delivery. Timed-pregnant Sprague-Dawley rats (n=36) were used. On day 14 of gestation, the FUS system was placed on the body surface of the rat over the cervix and ultrasound energy was applied to cervix for variable times up to 1 hour in the control group, the FUS system was placed on rats but no energy was applied. Daily measurement of cervix light-induced florescence (LIF, photon counts of collagen x-bridge fluorescence) were made on days 16 of gestation and daily until spont-aneous delivery (day22) to estimate changes in cervical ripening. We found that pulses of 680 KHz ultrasound at 25 Hertz, 1 millisecond pulse duration at 1W/cm^2 applied for as little as 30 minutes would immediately afterwards show the cervix to hav e ripened to the degree seen just before delivery on day 22. Delivery times, fetal weights and viability were unaffected in the FUS-treated animals.
ContributorsLuo, Daishen (Author) / Towe, Bruce C (Thesis advisor) / Wang, Xiao (Committee member) / Caplan, Michael (Committee member) / Arizona State University (Publisher)
Created2012
Description
The Holocaust and the effects it has had upon witnesses has been a topic of study for nearly six decades; however, few angles of research have been conducted relating to the long-term effects of the Holocaust upon the children and grandchildren of Holocaust survivors--the After Generations. The After Generations are considered the proof--the living legacies--that their parents and grandparents survived. Growing up with intimate knowledge of the atrocities that occurred during the Holocaust, members of the After Generations not only carry with them their family's story, but also their own vicarious experience(s) of trauma. From this legacy comes a burden of responsibility to those who perished, their survivor parents/grandparents, the stories that were shared, as well as to future generations. Using grounded theory method, this study not only explores the long-term effects of the Holocaust upon members of the After Generations, but what it means to responsibly remember the stories from the Holocaust, as well as how individuals might ethically represent such stories/memories. Findings that developed out of an axial analysis of interview transcripts and journal writing, as well as the later development of a performance script, are embodied in a manner that allows the actual language and experiences of the participants to be collectively witnessed both symbolically and visually. Through their desire to remember, members of the After Generations demonstrate how they plan to carry on traditions, live lives that honor those that came before them, and maintain hope for the future. In so doing, the stories shared reveal the centrality of the Holocaust in the lives of members of the After Generations through their everyday choices to responsibly and actively remember through their art, writings, life-work, as well as from within their work in their local communities. Such acts of remembrance are important to the education of others as well as to the construction and maintenance of the After Generations' identities. The representation of these voices acts as a reminder of how hatred and its all-consuming characteristics can affect not only the person targeted, but multiple generations, as well.
ContributorsRath, Sandra (Author) / de la Garza, Sarah Amira (Thesis advisor) / Underiner, Tamara (Committee member) / Corey, Frederick C. (Committee member) / Eisenberg, Judith (Committee member) / Arizona State University (Publisher)
Created2012
Description
Law enforcement, schools and universities, health service agencies, as well as social service agencies, each acquire information from individuals that receive their services. That information gets recorded into the respective application system of each organization. The information, however, gets recorded only in the context of each service rendered and within each system used to record it. Information that is recorded by the police department for one individual is entirely different from the information that is recorded by the hospital for that same individual. What if all the organizations used the same system to record information? What if all the organizations followed the same protocols to record information as well as access it? The goal of this research was to analyze a system that allows for all organizations within a community to share information with each other. Technically, this system is feasible. However, public opinion says sharing personal information is unethical, and Federal regulation says it is unlawful. To accomplish an information-sharing system of this type, both regulation and public opinion need to be addressed.
ContributorsPullin, Britton Scott (Author) / Schildgen, Thomas (Thesis advisor) / Prewitt, Deborah (Committee member) / Ralston, Laurel (Committee member) / Arizona State University (Publisher)
Created2012
Description
Alzheimer's disease (AD) is the leading neurodegenerative disease, affecting roughly 8% of people 65 years of age or older. There exists an imperative need to develop a non-invasive test for the earlier detection of AD. The use of biomarkers is a promising option that examines the toxic mechanisms and metabolic pathways that cause Alzheimer's disease, eventually leading to an early diagnostic method. This thesis presents the use of oligomeric beta-amyloid as a biomarker to detect Alzheimer's disease via a specialized enzyme-linked protein assay. Specifically, this paper details the optimization and development of a novel phage capture enzyme-linked immunosorbent assay (ELISA) that can detect the relative quantity of beta-amyloid oligomers in samples from a mouse model of AD. The objective of this thesis was to optimize a phage capture ELISA using the A4 single-chain variable fragment (scFv) to quantify the amount of beta-amyloid oligomers in various mice samples. A4 selectively recognizes a toxic oligomeric form of beta-amyloid. The level of A4-reactive oligomeric beta-amyloid was measured in triplicate in homogenized mouse brain tissue samples from eight transgenic (TG) and eight nontransgenic (NTG) animals aged five, nine, and thirteen months. There was a significant difference (p < 0.0005) between the five month TG and NTG mice. A decrease in beta-amyloid levels with the aging of the TG mice suggested that the beta-amyloid oligomers may be aggregating to form beta-amyloid fibrils. Conversely, the quantity of beta-amyloid increased with the aging of the NTG mice. This indicated that beta-amyloid oligomers may develop with normal aging.
ContributorsBrownlee, Taylor (Author) / Sierks, Michael (Thesis advisor) / Williams, Stephanie (Committee member) / Xin, Wei (Committee member) / Arizona State University (Publisher)
Created2013