10,989 research outputs found

    In the Pause and Listening to the Little People: A Folk Healer’s Journey

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    Rockey Robbins, PhD (Cherokee/Choctaw), is an associate professor in counseling psychology at the University of Oklahoma. His research has been primarily with Native Americans in the areas of spirituality, family resiliency, boarding school experiences, and renorming psychological assessment instruments.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Functional Source Separation for EEG-fMRI Fusion: Application to Steady-State Visual Evoked Potentials

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    Neurorobotics is one of the most ambitious fields in robotics, driving integration of interdisciplinary data and knowledge. One of the most productive areas of interdisciplinary research in this area has been the implementation of biologically-inspired mechanisms in the development of autonomous systems. Specifically, enabling such systems to display adaptive behavior such as learning from good and bad outcomes, has been achieved by quantifying and understanding the neural mechanisms of the brain networks mediating adaptive behaviors in humans and animals. For example, associative learning from aversive or dangerous outcomes is crucial for an autonomous system, to avoid dangerous situations in the future. A body of neuroscience research has suggested that the neurocomputations in the human brain during associative learning involve re-shaping of sensory responses. The nature of these adaptive changes in sensory processing during learning however are not yet well enough understood to be readily implemented into on-board algorithms for robotics application. Toward this overall goal, we record the simultaneous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI), characterizing one candidate mechanism, i.e., large-scale brain oscillations. The present report examines the use of Functional Source Separation (FSS) as an optimization step in EEG-fMRI fusion that harnesses timing information to constrain the solutions that satisfy physiological assumptions. We applied this approach to the voxel-wise correlation of steady-state visual evoked potential (ssVEP) amplitude and blood oxygen level-dependent imaging (BOLD), across both time series. The results showed the benefit of FSS for the extraction of robust ssVEP signals during simultaneous EEG-fMRI recordings. Applied to data from a 3-phase aversive conditioning paradigm, the correlation maps across the three phases (habituation, acquisition, extinction) show converging results, notably major overlapping areas in both primary and extended visual cortical regions, including calcarine sulcus, lingual cortex, and cuneus. In addition, during the acquisition phase when aversive learning occurs, we observed additional correlations between ssVEP and BOLD in the anterior cingulate cortex (ACC) as well as the precuneus and superior temporal gyrus

    Nanodiamond in tellurite glass Part I: origin of loss in nanodiamond-doped glass

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    Tellurite glass fibers with embedded nanodiamond are attractive materials for quantum photonic applications. Reducing the loss of these fibers in the 600-800 nm wavelength range of nanodiamond fluorescence is essential to exploit the unique properties of nanodiamond in the new hybrid material. In the first part of this study, we report the effect of interaction of the tellurite glass melt with the embedded nanodiamond on the loss of the glasses. The glass fabrication conditions such as melting temperature and concentration of NDs added to the melt were found to have critical influence on the interaction. Based on this understanding, we identified promising fabrication conditions for decreasing the loss to levels required for practical applications.Comment: 13 pages, 6 figure

    Dynamic Mechanical Behavior & Analysis of the Jute-Glass Fiber Reinforced Polyester Hybrid Composites

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    The development of composite materials based on the reinforcement of two or more fiber types in a matrix leads to the production of hybrid composites. In the present work, hessian jute cloth, non-woven E-glass and polyester resin were used to prepare jute/polyester, glass/polyester and jute-glass hybrid polyester composites by hand lay-up and heat press molding techniques and their mechanical properties were evaluated for different stacking sequences. In Jute/polyester and glass/polyester composites, mechanical properties such as tensile properties, bending properties and impact strength increase with the increases of stacking sequences. In case of jute-glass hybrid composites, the composites which content more glass layer than that of jute layer shows the higher mechanical properties. Water uptake (%) of these composites demonstrate that water absorption rate is initially higher for jute/polyester composite and at a stage it become steady (31.11%), but in case of glass/polyester and jute-glass hybrid composites the absorption rate is very low which is almost less than 1% due to the hydrophobic nature of glass fiber and polyester resin. Soil degradation test of all types of composites were evaluated and the deterioration of the mechanical properties revealed for all the composites where jute/polyester composites showed the higher degree but E-glass/polyester composites retained major portion of its original integrity and their hybrid declined more than glass but less than jute composites. The composites were also radiated under gamma radiation (50 kCi Cobalt 60 Source) of various doses (1-12.5 kGy). It was found that by using gamma radiation, the mechanical properties of the composites were improved
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