Sensorimotor Adaptation of Speech Using Real-time Articulatory Resynthesis

Sensorimotor adaptation is an important focus in the study of motor learning for non-disordered speech, but has yet to be studied substantially for speech rehabilitation. Speech adaptation is typically elicited experimentally using LPC resynthesis to modify the sounds that a speaker hears himself producing. This method requires that the participant be able to produce a robust speech-acoustic signal and is therefore not well-suited for talkers with dysarthria. We have developed a novel technique using electromagnetic articulography (EMA) to drive an articulatory synthesizer. The acoustic output of the articulatory synthesizer can be perturbed experimentally to study auditory feedback effects on sensorimotor learning. This work aims to compare sensorimotor adaptation effects using our articulatory resynthesis method with effects from an established, acoustic-only method. Results suggest that the articulatory resynthesis method can elicit speech adaptation, but that the articulatory effects of the two methods differ

Concentration and separation of trace metal ions by reversed-phase adsorption chromatography

The concentration and separation of trace metal ions chelated with either bis(2-hydroxyethyl)dithiocarbamate (HEDC) or 1,3-dimethyl-4-acetyl-2-pyrazolin-5-one (DMAP) by reversed-phase adsorption chromatography has been studied. Both reagents form water-soluble, neutral metal chelates that can be adsorbed onto a reversed-phase stationary phase;The concentration of metals of the hydrogen sulfide group from very dilute solution by chelation with HEDC and subsequent adsorption on a small column of Amberlite XAD-4 resin is described. Selectivity is achieved by pH adjustment or by the use of masking agents. The metal chelates are eluted from the column with acidic ethanol and determined by AAS;The adsorption properties of five XAD resins and three activated carbons have been studied for removing metal ions chelated with HEDC from industrial wastewater. Amberlite XAD-4 and Nuchar WV-B activated carbon were found to have the highest adsorption capacities. The adsorbents can be regenerated with methanol;The HEDC chelates of Co(III), Cu(II), Ni(II), and Hg(II) have been separated by reversed-phase HPLC. Co(III), Cu(II), and Ni(II) can be determined in the range of 0.005 - 10.0 mg/L, while Hg(II) can be determined in the range of 0.02 - 25 (mu)g/L after an on-line preconcentration step;The synthesis and characterization of DMAP is described. This reagent forms stable chelates with Zr(IV), Th(IV), and U(VI). The UO(,2)(DMAP)(,2) chelate has been prepared and characterized. A procedure for concentrating trace amounts of U(VI) chelated with DMAP onto XAD-4 resin is described

Speech Sensorimotor Learning through a Virtual Vocal Tract

Studies of speech sensorimotor learning often manipulate auditory feedback by modifying isolated acoustic parameters such as formant frequency or fundamental frequency using near real-time resynthesis of a participant\u27s speech. An alternative approach is to engage a participant in a total remapping of the sensorimotor working space using a virtual vocal tract. To support this approach for studying speech sensorimotor learning we have developed a system to control an articulatory synthesizer using electromagnetic articulography data. Articulator movement data from the NDI Wave System are streamed to a Maeda articulatory synthesizer. The resulting synthesized speech provides auditory feedback to the participant. This approach allows the experimenter to generate novel articulatory-acoustic mappings. Moreover, the acoustic output of the synthesizer can be perturbed using acoustic resynthesis methods. Since no robust speech-acoustic signal is required from the participant, this system will allow for the study of sensorimotor learning in any individuals, even those with severe speech disorders. In the current work we present preliminary results that demonstrate that typically-functioning participants can use a virtual vocal tract to produce diphthongs within a novel articulatory-acoustic workspace. Once sufficient baseline performance is established, perturbations to auditory feedback (formant shifting) can elicit compensatory and adaptive articulatory responses

Electrogenic uptake of gamma-aminobutyric acid by a cloned transporter expressed in Xenopus oocytes

GAT-1, a gamma-aminobutyric acid (GABA) transporter cloned from rat brain, was expressed in Xenopus oocytes. Voltage-clamp measurements showed concentration-dependent, inward currents in response to GABA (K0.5 4.7 microM). The transport current required extracellular sodium and chloride ions; the Hill coefficient for chloride was 0.7, and that for sodium was 1.7. Correlation of current and [3H]GABA uptake measurements indicate that flux of one positive charge occurs per molecule of GABA transported. Membrane hyperpolarization from -40 to -100 mV increased the transport current approximately 3-fold. The results indicate that the transport of one molecule of GABA involves the co-transport of two sodium ions and one chloride ion

Event driven sediment mobility on the inner continental shelf of Onslow Bay, NC

This study seeks to further constrain near-bottom hydrodynamic current conditions required to mobilize native sediments on a high-energy sediment starved shelf environment and link these data to changes in sidescan sonar imagery of the inner-shelf environment of Onslow Bay, NC. A bottom-mounted upward looking Acoustic Doppler Current Profiler (ADCP) deployed at the OB3M study site on the lower sand flat adjacent to a low-relief marine hardbottom recorded hourly flow velocity profiles from a depth of 17.7 m. The lower sand flat is composed of two dominant surficial lithofacies consisting of patchy, but well-defined areas of well sorted fine sand and poorly sorted coarse grained material. A dual frequency high-resolution sidescan sonar system was utilized to biannually survey a 5.5 by 3.7 km area encompassing the OB3M site between March 2002 and October 2003. Mosaic imagery obtained from these surveys were used to document seasonal changes in bottom characteristics in response to twenty-three identified sediment mobility events. Measurable contributions from semidiurnal tidal flows, mean current flows dominated by subtidal wind-generated currents, as well as wave-generated oscillatory motions in the near-bottom layer during storm and non-storm conditions have been identified for the nineteen-month period bracketing two tropical storm seasons off the North Carolina coast. Calculated critical shear velocity values due to the combined effects of waves and currents indicate that the fine-grained sand fraction was mobile more than 66% of the period, frequently as incipiently suspended load and bedload, and rarely as fully suspended load. Quantitative analysis of sidescan sonar imagery demonstrate that even though hydrodynamic conditions favor mobilization of fine sands, the gross morphology and sediment distribution at this inner-shelf site remained relatively unchanged after the occurrence of several commonplace high-energy events. Seasonal sedimentation patterns, however; were found to be substantially altered after the passage of Hurricane Isabel within 225 km of the study site. Evidence from this study reveals that over the nineteen-month study period at this discrete site, the combined effects of typical high-energy events had little effect on the net distribution of bottom sediments, yet a singular extreme event was found to actively modify seabed sedimentation processes

"A grand bloodbath" : the western reaction to Joseph Stalin's 1930s show trials as foreign policy

Joseph Stalin’s show trials, held in Moscow in the 1930s, are generally regarded by many historians primarily as a domestic policy move designed to remove opposition. This is not the entire picture. The trials need to be examined as part of a foreign policy maneuver designed by Stalin as a reaction to other world events occurring at the time, including the Great Depression, the Spanish Civil War, the rise of fascism in Germany and Italy, and the threat of an increasingly militaristic Japan. In analyzing the reactions of the West, including sources such as journalists and ambassadors, the individual trials of 1936, 1937, and 1938 can be more easily seen as part of Soviet foreign policy. However, the increasing criticism and lack of support from the West ultimately led to a failure in foreign policy on the part of Joseph Stalin

"His love is real, but he is not" : examination of reality in Spielberg's AI: artificial intelligence

Steven Spielberg’s 2001 film AI: Artificial Intelligence, based on Brian Aldiss’ short story “Supertoys Last All Summer Long,” deals with important issues of reality and how artificial intelligence, known in the film as mechas, can have emotions and thoughts of their own, transcending the limitations imposed on them by their creators. Literary theories from postmodernist Jean Baudrillard to cyborg theorist Donna Haraway serve to illuminate and challenge Spielberg’s vision of the future, as well as show how these issues relate to the world today. The protagonist in AI, David, is a young mecha boy built with the ability to love its owner; in David’s case, Monica, his “mother.” David spends most of the film trying to become a real boy so Monica will love him as much as he loves her. The main issue of AI is whether or not David’s feelings are authentic or merely a construct implemented by his creator, Professor Hobby. Baudrillard’s Simulations suggests not only are our feelings simulated, but also our conception of reality as well. Haraway’s essay “A Cyborg Manifesto” argues that the confusion generated by the eroding boundaries between human and machine results in the rise of a cyborgian way of life. I make the case that David shares important similarities with cyborgs because of the humanity of his emotions and his need for love and acceptance from Monica. The possibility of an artificial creation with human feelings and desires raises questions about human interaction with mechas like David, challenging human conceptions of reciprocal love

Painting within the realist tradition

The work I am presenting for this thesis exhibition results from my active observation of nature and the problems encountered when applying this observation to painting. Since correctness of observation, or keenness of perception is a large part of this process my work involves drawing and painting from life. Through drawing and the careful application of color I attempt to present a credible visual reality as I perceive it in nature. The subjects I chose for this investigation have no great significance. They are simple still-lifes or self-portraits. In the still-lifes my major concern is presenting the objects as velumetric shapes and placing them in correct relation to each other upon the horizontal plane on which they rest. In my self-portraits I use the same investigations of relative distances between points within space, except that these distances are not as great; I focus on a single volume within a more confined space. Through these investigations I have found that painting goes beyond the idea, or pictorial image of the objects or situation depicted. Instead it obtains a presence or sense of life of its own apart from the situation taking place in nature