Central Executive Dysfunction and Deferred Prefrontal Processing in Veterans with Gulf War Illness.

Gulf War Illness is associated with toxic exposure to cholinergic disruptive chemicals. The cholinergic system has been shown to mediate the central executive of working memory (WM). The current work proposes that impairment of the cholinergic system in Gulf War Illness patients (GWIPs) leads to behavioral and neural deficits of the central executive of WM. A large sample of GWIPs and matched controls (MCs) underwent functional magnetic resonance imaging during a varied-load working memory task. Compared to MCs, GWIPs showed a greater decline in performance as WM-demand increased. Functional imaging suggested that GWIPs evinced separate processing strategies, deferring prefrontal cortex activity from encoding to retrieval for high demand conditions. Greater activity during high-demand encoding predicted greater WM performance. Behavioral data suggest that WM executive strategies are impaired in GWIPs. Functional data further support this hypothesis and suggest that GWIPs utilize less effective strategies during high-demand WM

Nonparametric Bayesian Double Articulation Analyzer for Direct Language Acquisition from Continuous Speech Signals

Human infants can discover words directly from unsegmented speech signals without any explicitly labeled data. In this paper, we develop a novel machine learning method called nonparametric Bayesian double articulation analyzer (NPB-DAA) that can directly acquire language and acoustic models from observed continuous speech signals. For this purpose, we propose an integrative generative model that combines a language model and an acoustic model into a single generative model called the "hierarchical Dirichlet process hidden language model" (HDP-HLM). The HDP-HLM is obtained by extending the hierarchical Dirichlet process hidden semi-Markov model (HDP-HSMM) proposed by Johnson et al. An inference procedure for the HDP-HLM is derived using the blocked Gibbs sampler originally proposed for the HDP-HSMM. This procedure enables the simultaneous and direct inference of language and acoustic models from continuous speech signals. Based on the HDP-HLM and its inference procedure, we developed a novel double articulation analyzer. By assuming HDP-HLM as a generative model of observed time series data, and by inferring latent variables of the model, the method can analyze latent double articulation structure, i.e., hierarchically organized latent words and phonemes, of the data in an unsupervised manner. The novel unsupervised double articulation analyzer is called NPB-DAA. The NPB-DAA can automatically estimate double articulation structure embedded in speech signals. We also carried out two evaluation experiments using synthetic data and actual human continuous speech signals representing Japanese vowel sequences. In the word acquisition and phoneme categorization tasks, the NPB-DAA outperformed a conventional double articulation analyzer (DAA) and baseline automatic speech recognition system whose acoustic model was trained in a supervised manner.Comment: 15 pages, 7 figures, Draft submitted to IEEE Transactions on Autonomous Mental Development (TAMD

Liver imaging : it is time to adopt standardized terminology

Liver imaging plays a vital role in the management of patients at risk for hepatocellular carcinoma (HCC); however, progress in the field is challenged by nonuniform and inconsistent terminology in the published literature. The Steering Committee of the American College of Radiology (ACR)’s Liver Imaging Reporting And Data System (LI-RADS), in conjunction with the LI-RADS Lexicon Writing Group and the LI-RADS International Working Group, present this consensus document to establish a single universal liver imaging lexicon. The lexicon is intended for use in research, education, and clinical care of patients at risk for HCC (i.e., the LI-RADS population) and in the general population (i.e., even when LI-RADS algorithms are not applicable). We anticipate that the universal adoption of this lexicon will provide research, educational, and clinical benefits

Using podcasts to mediate reflective learning : a case of a postgraduate programme at a higher education institution

Includes bibliographical references (leaves 108-117).Although reflective learning in higher education is increasing, not much research has been conducted on using reflective learning for discursive knowledge production among students whose first language is not English. Discursive knowledge production is the meaning making process initiated when one encounters new information. This implies that students whose first language is not English are less likely to be active discussants and are disadvantaged participants in discursive knowledge production activities. The research question this study sought to answer is: how are podcasts used to mediate reflection among postgraduate students at an institution of higher education? The researcher used Hatton and Smith’s framework to explore and identify the types of reflection that podcast use mediates

Quantifying Planarian Behavior As An Introduction To Object Tracking And Signal Processing

Answers to mechanistic questions about biological phenomena require fluency in a variety of molecular biology techniques and physical concepts. Here, we present an interdisciplinary approach to introducing undergraduate students to an important problem in the areas of animal behavior and neuroscience—the neuronal control of animal behavior. In this lab module, students explore planarian behavior by quantitative image and data analysis with freely available software and low-cost resources. Planarians are ∼1–2-cm-long aquatic free-living flatworms famous for their regeneration abilities. They are inexpensive and easy to maintain, handle, and perturb, and their fairly large size allows for image acquisition with a webcam, which makes this lab module accessible and scalable. Our lab module integrates basic physical concepts such as center of mass, velocity and speed, periodic signals, and time series analysis in the context of a biological system. The module is designed to attract students with diverse disciplinary backgrounds. It challenges the students to form hypotheses about behavior and equips them with a basic but broadly applicable toolkit to achieve this quantitatively. We give a detailed description of the necessary resources and show how to implement the module. We also provide suggestions for advanced exercises and possible extensions. Finally, we provide student feedback from a pilot implementation

From Artifacts to Aggregations: Modeling Scientific Life Cycles on the Semantic Web

In the process of scientific research, many information objects are generated, all of which may remain valuable indefinitely. However, artifacts such as instrument data and associated calibration information may have little value in isolation; their meaning is derived from their relationships to each other. Individual artifacts are best represented as components of a life cycle that is specific to a scientific research domain or project. Current cataloging practices do not describe objects at a sufficient level of granularity nor do they offer the globally persistent identifiers necessary to discover and manage scholarly products with World Wide Web standards. The Open Archives Initiative's Object Reuse and Exchange data model (OAI-ORE) meets these requirements. We demonstrate a conceptual implementation of OAI-ORE to represent the scientific life cycles of embedded networked sensor applications in seismology and environmental sciences. By establishing relationships between publications, data, and contextual research information, we illustrate how to obtain a richer and more realistic view of scientific practices. That view can facilitate new forms of scientific research and learning. Our analysis is framed by studies of scientific practices in a large, multi-disciplinary, multi-university science and engineering research center, the Center for Embedded Networked Sensing (CENS).Comment: 28 pages. To appear in the Journal of the American Society for Information Science and Technology (JASIST

The Effects Of Peer Administered Methods For Increasing Social Interaction Between Young Handicapped And Nonhandicapped Children

The purpose of the study was to compare the use of peer administered contingent reinforcement for social interaction with the use of play materials that facilitate interaction. The subsequent effects on the social interaction of mainstreamed preschool handicapped children with their nonhandicapped peers was examined. Three nonhandicapped kindergarten children were paired with three moderately mentally handicapped preschool children and trained to initiate play. A single-subject, alternating treatment design with a withdrawal phase was used to compare the effects of the two treatments. Generalization immediately following each treatment was also examined as was maintenance over time. Observers used an interval recording procedure and showed a mean interobserver reliability rating of 95%. All observations were conducted in an outdoor playground setting. The use of play materials that facilitate interaction (Treatment C) was shown to be a significantly more effective method for increasing social interaction than was the use of peer administered contingent reinforcement (Treatment B). The mean child-child interaction total for Treatment C was 71% while the mean child-child interaction total for Treatment B was 27%. The t value at a.10 level of probability was $-7.74$. Generalization immediately following treatment was greater after Treatment C (mean 24%) than after Treatment B (mean 7%). The t value of $-1.98$ did not, however, show a significant difference in generalization between the two treatments. Treatment C was implemented as the only treatment upon completion of the alternating treatment phase. Relatively little generalization occurred during the withdrawal phase (mean 17%) and the treatment effects were not maintained over time (mean 7%). A supplemental analysis of the relationship between play attempts by the peer helper and the number of actual interactions showed that, while there were a greater number of play attempts during Treatment C than during Treatment B, the difference was not large enough to account for the success of Treatment C. The outcome of the study helps to ascertain that the use of trained nonhandicapped peer helpers coupled with the use of play materials that facilitate interaction can be an effective means of increasing social interaction between young handicapped and nonhandicapped children