12,240 research outputs found

    Near-Earth Supernova Explosions: Evidence, Implications, and Opportunities

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    There is now solid experimental evidence of at least one supernova explosion within 100 pc of Earth within the last few million years, from measurements of the short-lived isotope ā¶ā°Fe in widespread deep-ocean samples, as well as in the lunar regolith and cosmic rays. This is the first established example of a specific dated astrophysical event outside the Solar System having a measurable impact on the Earth, offering new probes of stellar evolution, nuclear astrophysics, the astrophysics of the solar neighborhood, cosmic-ray sources and acceleration, multi-messenger astronomy, and astrobiology. Interdisciplinary connections reach broadly to include heliophysics, geology, and evolutionary biology. Objectives for the future include pinning down the nature and location of the established near-Earth supernova explosions, seeking evidence for others, and searching for other short-lived isotopes such as Ā²ā¶Al and Ā²ā“ā“Pu. The unique information provided by geological and lunar detections of radioactive ā¶ā°Fe to assess nearby supernova explosions make now a compelling time for the astronomy community to advocate for supporting multi-disciplinary, cross-cutting research programs

    Usability evaluation of digital libraries: a tutorial

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    This one-day tutorial is an introduction to usability evaluation for Digital Libraries. In particular, we will introduce Claims Analysis. This approach focuses on the designersā€™ motivations and reasons for making particular design decisions and examines the effect on the userā€™s interaction with the system. The general approach, as presented by Carroll and Rosson(1992), has been tailored specifically to the design of digital libraries. Digital libraries are notoriously difficult to design well in terms of their eventual usability. In this tutorial, we will present an overview of usability issues and techniques for digital libraries, and a more detailed account of claims analysis, including two supporting techniques ā€“ simple cognitive analysis based on Normanā€™s ā€˜action cycleā€™ and Scenarios and personas. Through a graduated series of worked examples, participants will get hands-on experience of applying this approach to developing more usable digital libraries. This tutorial assumes no prior knowledge of usability evaluation, and is aimed at all those involved in the development and deployment of digital libraries

    Human response to aircraft noise

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    The human auditory system and the perception of sound are discussed. The major concentration is on the annnoyance response and methods for relating the physical characteristics of sound to those psychosociological attributes associated with human response. Results selected from the extensive laboratory and field research conducted on human response to aircraft noise over the past several decades are presented along with discussions of the methodology commonly used in conducting that research. Finally, some of the more common criteria, regulations, and recommended practices for the control or limitation of aircraft noise are examined in light of the research findings on human response

    High level cognitive information processing in neural networks

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    Two related research efforts were addressed: (1) high-level connectionist cognitive modeling; and (2) local neural circuit modeling. The goals of the first effort were to develop connectionist models of high-level cognitive processes such as problem solving or natural language understanding, and to understand the computational requirements of such models. The goals of the second effort were to develop biologically-realistic model of local neural circuits, and to understand the computational behavior of such models. In keeping with the nature of NASA's Innovative Research Program, all the work conducted under the grant was highly innovative. For instance, the following ideas, all summarized, are contributions to the study of connectionist/neural networks: (1) the temporal-winner-take-all, relative-position encoding, and pattern-similarity association techniques; (2) the importation of logical combinators into connection; (3) the use of analogy-based reasoning as a bridge across the gap between the traditional symbolic paradigm and the connectionist paradigm; and (4) the application of connectionism to the domain of belief representation/reasoning. The work on local neural circuit modeling also departs significantly from the work of related researchers. In particular, its concentration on low-level neural phenomena that could support high-level cognitive processing is unusual within the area of biological local circuit modeling, and also serves to expand the horizons of the artificial neural net field

    Assessing Unmet Needs of Caregivers after Stroke: Occupational Therapist Practices and Perspectives

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    Background: Family caregivers of stroke survivors often feel unprepared and overwhelmed post discharge with numerous unmet needs. Occupational therapists can play an integral role in addressing family caregiversā€™ needs. Limited research exists on assessment practices of occupational therapists in identifying caregiversā€™ needs poststroke. This study explores the practices and perspectives of occupational therapists in assessing unmet caregiversā€™ needs. Method: A cross-sectional, mixed methods research design was used to electronically survey 15 occupational therapists. Part 1 of the survey explored participant methods for identifying caregiversā€™ needs and their views on using formal caregiver assessment tools. Part 2 gathered participant perspectives on three selected caregiver assessments. Descriptive statistics and thematic analysis were used to interpret the data. Results: The participants perceive formal assessments as beneficial. However, they use informal strategies to assess the unmet needs of caregivers rather than formal assessment. Reimbursement challenges, productivity pressure, and questionable necessity are barriers to conducting formal assessments. Advantages and disadvantages of each assessment are discussed. Conclusion: Occupational therapists face barriers to conducting formal assessment across settings. Implementation of recent policies is needed to further support occupational therapyā€™s role in addressing caregiversā€™ needs. This study can inform future development of assessment tools tailored to occupational therapy
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