403 research outputs found

    An automated motion detection and reward system for animal training

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    article distributed under the terms of the Creative Commons Attribution License CC-BY 3.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Multivariate pattern classification of pediatric Tourette syndrome using functional connectivity MRI

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    Tourette syndrome (TS) is a developmental neuropsychiatric disorder characterized by motor and vocal tics. Individuals with TS would benefit greatly from advances in prediction of symptom timecourse and treatment effectiveness. As a first step, we applied a multivariate method - support vector machine (SVM) classification - to test whether patterns in brain network activity, measured with resting state functional connectivity (RSFC) MRI, could predict diagnostic group membership for individuals. RSFC data from 42 children with TS (8-15 yrs) and 42 unaffected controls (age, IQ, in-scanner movement matched) were included. While univariate tests identified no significant group differences, SVM classified group membership with ~70% accuracy (p < .001). We also report a novel adaptation of SVM binary classification that, in addition to an overall accuracy rate for the SVM, provides a confidence measure for the accurate classification of each individual. Our results support the contention that multivariate methods can better capture the complexity of some brain disorders, and hold promise for predicting prognosis and treatment outcome for individuals with TS

    Troubled Worlds: A Course Syllabus about Information Work and the Anthropocene

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    The goal of this syllabus is to interrogate the material, and socioeconomic processes which underpin our everyday information work. In particular, we examine the relationships developing between contemporary information practices and what problematically gets configured as “nature”—that messy world of non-human entanglements that often exists beyond the purview of innovation work, whether digital software development or industrial engineering. Much recent work on the environmental conditions of computing has sought to break down technology-nature dualisms in order to expose the implication of information technology in broader social and material ecologies. Library and information professionals and researchers are well poised to deepen this inquiry by presenting alternative nature-technology epistemologies grounded in longstanding analyses of information resources and their consumption. The “Troubled Worlds” syllabus starts with a discussion of concerns most obviously germane to the work of most library and information science professionals: practices at the intersection of structuring information and computing. Building on this attention, we turn to humanistic approaches to thinking through the era of dominant human activities widely known as the “Anthropocene” by introducing poetic, artistic, and activist lenses. We explore how artistic objects representing an increasingly troubled natural world raise awareness of the challenges facing it, as well as how they may incorporate and reshape information for aesthetic ends. We then look to questions of disability justice and how it works in blended built and natural spaces as well as the many different ways in which bodies respond to the toxic environments produced by information technologies. We next consider the newer design approaches to library and information research, specifically asking how design perspectives on digital information objects get inscribed in the Anthropocene. Lastly, we consider paradigms of repair and making and analyze the different valences through which information researchers and professionals categorize and contextualize what is possible with them. This compilation does not provide a comprehensive review of the literature on the environment within the information fields. Instead, it extends this literature to promote experimental research and practice. The modules construct an interdisciplinary and provisional path through the related literature in a form that we hope may be continually adjusted, rearranged, and augmented. Pre-print first published online 03/15/202

    The Intrinsic Eddington Ratio Distribution of Active Galactic Nuclei in Star-Forming Galaxies from the Sloan Digital Sky Survey

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    An important question in extragalactic astronomy concerns the distribution of black hole accretion rates of active galactic nuclei (AGNs). Based on observations at X-ray wavelengths, the observed Eddington ratio distribution appears as a power law, while optical studies have often yielded a lognormal distribution. There is increasing evidence that these observed discrepancies may be due to contamination by star formation and other selection effects. Using a sample of galaxies from the Sloan Digital Sky Survey Data Release 7, we test whether or not an intrinsic Eddington ratio distribution that takes the form of a Schechter function is consistent with previous work suggesting that young galaxies in optical surveys have an observed lognormal Eddington ratio distribution. We simulate the optical emission line properties of a population of galaxies and AGNs using a broad, instantaneous luminosity distribution described by a Schechter function near the Eddington limit. This simulated AGN population is then compared to observed galaxies via their positions on an emission line excitation diagram and Eddington ratio distributions. We present an improved method for extracting the AGN distribution using BPT diagnostics that allows us to probe over one order of magnitude lower in Eddington ratio, counteracting the effects of dilution by star formation. We conclude that for optically selected AGNs in young galaxies, the intrinsic Eddington ratio distribution is consistent with a possibly universal, broad power law with an exponential cutoff, as this distribution is observed in old, optically selected galaxies and X-rays

    Spatial reorganization of putaminal dopamine D2-like receptors in cranial and hand dystonia

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    The putamen has a somatotopic organization of neurons identified by correspondence of firing rates with selected body part movements, as well as by complex, but organized, differential cortical projections onto putamen. In isolated focal dystonia, whole putaminal binding of dopamine D(2)-like receptor radioligands is quantitatively decreased, but it has not been known whether selected parts of the putamen are differentially affected depending upon the body part affected by dystonia. The radioligand [(18)F]spiperone binds predominantly to D(2)-like receptors in striatum. We hypothesized that the spatial location of [(18)F]spiperone binding within the putamen would differ in patients with dystonia limited to the hand versus the face, and we tested that hypothesis using positron emission tomography and magnetic resonance imaging. To address statistical and methodological concerns, we chose a straightforward but robust image analysis method. An automated algorithm located the peak location of [(18)F]spiperone binding within the striatum, relative to a brain atlas, in each of 14 patients with cranial dystonia and 8 patients with hand dystonia. The mean (left and right) |x|, y, and z coordinates of peak striatal binding for each patient were compared between groups by t test. The location of peak [(18)F]spiperone binding within the putamen differed significantly between groups (cranial dystonia z<hand dystonia z, p = 0.016). We conclude that in isolated focal dystonia, dopamine D(2)-like receptors are distributed differently in the putamen depending on the body part manifesting dystonia

    GRB Polarimetry with POET

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    POET (Polarimeters for Energetic Transients) represents a concept for a Small Explorer (SMEX) satellite mission, whose principal scientific goal is to understand the structure of GRB sources through sensitive X‐ray and γ‐ray polarization measurements. The payload consists of two wide field‐of‐view (FoV) instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2–15 keV and a high energy polarimeter (Gamma‐Ray Polarimeter Experiment or GRAPE) that would measure polarization in the 60–500 keV energy range. The POET spacecraft provides a zenith‐pointed platform for maximizing the exposure to deep space. Spacecraft rotation provides a means of effectively dealing with any residual systematic effects in the polarization response. POET provides sufficient sensitivity and sky coverage to measure statistically significant polarization (for polarization levels in excess of 20%) for ∼80 GRBs in a two‐year mission. High energy polarization data would also be obtained for SGRs, solar flares, pulsars and other sources of astronomical interest

    Emotional eating phenotype is associated with central dopamine D2 receptor binding independent of body mass index

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    PET studies have provided mixed evidence regarding central D2/D3 dopamine receptor binding and its relationship with obesity as measured by body mass index (BMI). Other aspects of obesity may be more tightly coupled to the dopaminergic system. We characterized obesity-associated behaviors and determined if these related to central D2 receptor (D2R) specific binding independent of BMI. Twenty-two obese and 17 normal-weight participants completed eating- and reward-related questionnaires and underwent PET scans using the D2R-selective and nondisplaceable radioligand (N-[(11)C]methyl)benperidol. Questionnaires were grouped by domain (eating related to emotion, eating related to reward, non-eating behavior motivated by reward or sensitivity to punishment). Normalized, summed scores for each domain were compared between obese and normal-weight groups and correlated with striatal and midbrain D2R binding. Compared to normal-weight individuals, the obese group self-reported higher rates of eating related to both emotion and reward (p < 0.001), greater sensitivity to punishment (p = 0.06), and lower non-food reward behavior (p < 0.01). Across normal-weight and obese participants, self-reported emotional eating and non-food reward behavior positively correlated with striatal (p < 0.05) and midbrain (p < 0.05) D2R binding, respectively. In conclusion, an emotional eating phenotype may reflect altered central D2R function better than other commonly used obesity-related measures such as BMI
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