5,706 research outputs found

    Using Pinch Gloves(TM) for both Natural and Abstract Interaction Techniques in Virtual Environments

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    Usable three-dimensional (3D) interaction techniques are difficult to design, implement, and evaluate. One reason for this is a poor understanding of the advantages and disadvantages of the wide range of 3D input devices, and of the mapping between input devices and interaction techniques. We present an analysis of Pinch Glovesℱ and their use as input devices for virtual environments (VEs). We have developed a number of novel and usable interaction techniques for VEs using the gloves, including a menu system, a technique for text input, and a two-handed navigation technique. User studies have indicated the usability and utility of these techniques

    TARGET: Rapid Capture of Process Knowledge

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    TARGET (Task Analysis/Rule Generation Tool) represents a new breed of tool that blends graphical process flow modeling capabilities with the function of a top-down reporting facility. Since NASA personnel frequently perform tasks that are primarily procedural in nature, TARGET models mission or task procedures and generates hierarchical reports as part of the process capture and analysis effort. Historically, capturing knowledge has proven to be one of the greatest barriers to the development of intelligent systems. Current practice generally requires lengthy interactions between the expert whose knowledge is to be captured and the knowledge engineer whose responsibility is to acquire and represent the expert's knowledge in a useful form. Although much research has been devoted to the development of methodologies and computer software to aid in the capture and representation of some types of knowledge, procedural knowledge has received relatively little attention. In essence, TARGET is one of the first tools of its kind, commercial or institutional, that is designed to support this type of knowledge capture undertaking. This paper will describe the design and development of TARGET for the acquisition and representation of procedural knowledge. The strategies employed by TARGET to support use by knowledge engineers, subject matter experts, programmers and managers will be discussed. This discussion includes the method by which the tool employs its graphical user interface to generate a task hierarchy report. Next, the approach to generate production rules for incorporation in and development of a CLIPS based expert system will be elaborated. TARGET also permits experts to visually describe procedural tasks as a common medium for knowledge refinement by the expert community and knowledge engineer making knowledge consensus possible. The paper briefly touches on the verification and validation issues facing the CLIPS rule generation aspects of TARGET. A description of efforts to support TARGET's interoperability issues on PCs, Macintoshes and UNIX workstations concludes the paper

    Design of 2D Time-Varying Vector Fields

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    Differentiating between Hemorrhagic Infarct and Parenchymal Intracerebral Hemorrhage

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    Differentiating hemorrhagic infarct from parenchymal intracerebral hemorrhage can be difficult. The immediate and long-term management of the two conditions are different and hence the importance of accurate diagnosis. Using a series of intracerebral hemorrhage cases presented to our stroke unit, we aim to highlight the clues that may be helpful in distinguishing the two entities. The main clue to the presence of hemorrhagic infarct on computed tomography scan is the topographic distribution of the stroke. Additional imaging modalities such as computed tomography angiogram, perfusion, and magnetic resonance imaging may provide additional information in differentiating hemorrhagic infarct from primary hemorrhages

    Psychedelics Promote Structural and Functional Neural Plasticity.

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    Atrophy of neurons in the prefrontal cortex (PFC) plays a key role in the pathophysiology of depression and related disorders. The ability to promote both structural and functional plasticity in the PFC has been hypothesized to underlie the fast-acting antidepressant properties of the dissociative anesthetic ketamine. Here, we report that, like ketamine, serotonergic psychedelics are capable of robustly increasing neuritogenesis and/or spinogenesis both in vitro and in vivo. These changes in neuronal structure are accompanied by increased synapse number and function, as measured by fluorescence microscopy and electrophysiology. The structural changes induced by psychedelics appear to result from stimulation of the TrkB, mTOR, and 5-HT2A signaling pathways and could possibly explain the clinical effectiveness of these compounds. Our results underscore the therapeutic potential of psychedelics and, importantly, identify several lead scaffolds for medicinal chemistry efforts focused on developing plasticity-promoting compounds as safe, effective, and fast-acting treatments for depression and related disorders

    Radiative Models of Sagittarius A* and M87 from Relativistic MHD Simulations

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    Ongoing millimeter VLBI observations with the Event Horizon Telescope allow unprecedented study of the innermost portion of black hole accretion flows. Interpreting the observations requires relativistic, time-dependent physical modeling. We discuss the comparison of radiative transfer calculations from general relativistic MHD simulations of Sagittarius A* and M87 with current and future mm-VLBI observations. This comparison allows estimates of the viewing geometry and physical conditions of the Sgr A* accretion flow. The viewing geometry for M87 is already constrained from observations of its large-scale jet, but, unlike Sgr A*, there is no consensus for its millimeter emission geometry or electron population. Despite this uncertainty, as long as the emission region is compact, robust predictions for the size of its jet launching region can be made. For both sources, the black hole shadow may be detected with future observations including ALMA and/or the LMT, which would constitute the first direct evidence for a black hole event horizon.Comment: 8 pages, 2 figures, submitted to the proceedings of AHAR 2011: The Central Kiloparse

    Decreased Type I Interferon Production by Plasmacytoid Dendritic Cells Contributes to Severe Dengue

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    The clinical presentation of dengue virus (DENV) infection is variable. Severe complications mainly result from exacerbated immune responses. Type I interferons (IFN-I) are important in antiviral responses and form a crucial link between innate and adaptive immunity. Their contribution to host defense during DENV infection remains under-studied, as direct quantification of IFN-I is challenging. We combined ultra-sensitive single-molecule array (Simoa) digital ELISA with IFN-I gene expression to elucidate the role of IFN-I in a well-characterized cohort of hospitalized Cambodian children undergoing acute DENV infection. Higher concentrations of type I IFN proteins were observed in blood of DENV patients, compared to healthy donors, and correlated with viral load. Stratifying patients for disease severity, we found a decreased expression of IFN-I in patients with a more severe clinical outcome, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). This was seen in parallel to a correlation between low IFNα protein concentrations and decreased platelet counts. Type I IFNs concentrations were correlated to frequencies of plasmacytoid DCs, not DENV-infected myloid DCs and correlated inversely with neutralizing anti-DENV antibody titers. Hence, type I IFN produced in the acute phase of infection is associated with less severe outcome of dengue disease

    DrugBank 3.0: a comprehensive resource for ‘Omics’ research on drugs

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    DrugBank (http://www.drugbank.ca) is a richly annotated database of drug and drug target information. It contains extensive data on the nomenclature, ontology, chemistry, structure, function, action, pharmacology, pharmacokinetics, metabolism and pharmaceutical properties of both small molecule and large molecule (biotech) drugs. It also contains comprehensive information on the target diseases, proteins, genes and organisms on which these drugs act. First released in 2006, DrugBank has become widely used by pharmacists, medicinal chemists, pharmaceutical researchers, clinicians, educators and the general public. Since its last update in 2008, DrugBank has been greatly expanded through the addition of new drugs, new targets and the inclusion of more than 40 new data fields per drug entry (a 40% increase in data ‘depth’). These data field additions include illustrated drug-action pathways, drug transporter data, drug metabolite data, pharmacogenomic data, adverse drug response data, ADMET data, pharmacokinetic data, computed property data and chemical classification data. DrugBank 3.0 also offers expanded database links, improved search tools for drug–drug and food–drug interaction, new resources for querying and viewing drug pathways and hundreds of new drug entries with detailed patent, pricing and manufacturer data. These additions have been complemented by enhancements to the quality and quantity of existing data, particularly with regard to drug target, drug description and drug action data. DrugBank 3.0 represents the result of 2 years of manual annotation work aimed at making the database much more useful for a wide range of ‘omics’ (i.e. pharmacogenomic, pharmacoproteomic, pharmacometabolomic and even pharmacoeconomic) applications

    Describing interruptions, multi-tasking and task-switching in the community pharmacy: A qualitative study in England

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    Background: There is growing evidence base around interruptions and distractions in the community pharmacy setting. There is also evidence to suggest these practices may be associated with dispensing errors. Up to date, qualitative research on this subject is limited. Objective: To explore interruptions and distractions in the community setting; utilising an ethnographic approach to be able to provide a detailed description of the circumstances surrounding such practices. Setting: Community pharmacies in England, July to October 2011. Method: An ethnographic approach was taken. Non participant, unstructured observations were utilised to make records of pharmacists’ every activities. Case studies were formed by combining field notes with detailed information on pharmacists and their respective pharmacy businesses. Content analysis was undertaken both manually and electronically, utilising NVivo 10. Results: Response rate was 12% (n=11). Over fifteen days, a total of 123 hours and 58 minutes of observations were recorded in 11 separate pharmacies of 11 individual pharmacists. The sample was evenly split by gender (female n=6; male n=5) and pharmacy ownership (independent n=5; multiple n=6). Employment statuses included employee pharmacists (n=6), owners (n=4) and a locum (n=1). Average period of registration as a pharmacist was 19 years (range 5-39 years). Average prescriptions busyness of pharmacies ranged from 2,600 – 24,000 items dispensed per month. Two key themes were: “Interruptions and task-switching” and “distractions and multi-tasking.” All observed pharmacists’ work was dominated by interruptions, task-switches, distractions and multi-tasking, often to manage a barrage of conflicting demands. These practices were observed to be part of a deep-rooted culture in the community setting. Directional work maps illustrated the extent and direction of task switching employed by pharmacists. Conclusions: In this study pharmacists’ working practices were permeated by interruptions and multi-tasking. These practices are inefficient and potentially reduce patient safety in terms of dispensing accuracy
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