1,946 research outputs found

    Software Management Environment (SME) release 9.4 user reference material

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    This document contains user reference material for the Software Management Environment (SME) prototype, developed for the Systems Development Branch (Code 552) of the Flight Dynamics Division (FDD) of Goddard Space Flight Center (GSFC). The SME provides an integrated set of management tools that can be used by software development managers in their day-to-day management and planning activities. This document provides an overview of the SME, a description of all functions, and detailed instructions concerning the software's installation and use

    F-8C digital CCV flight control laws

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    A set of digital flight control laws were designed for the NASA F-8C digital fly-by-wire aircraft. The control laws emphasize Control Configured Vehicle (CCV) benefits. Specific pitch axis objectives were improved handling qualities, angle-of-attack limiting, gust alleviation, drag reduction in steady and maneuvering flight, and a capability to fly with reduced static stability. The lateral-directional design objectives were improved Dutch roll damping and turn coordination over a wide range in angle-of-attack. An overall program objective was to explore the use of modern control design methodilogy to achieve these specific CCV benefits. Tests for verifying system integrity, an experimental design for handling qualities evaluation, and recommended flight test investigations were specified

    Dedication - Dean Ralph C. Barnhart

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    Climate Change and Mountaintop Removal Mining: A MaxEnt Assessment of the Potential Dual Threat to West Virginia Fishes

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    Accounts of species’ range shifts in response to climate change, most often as latitudinal shifts towards the poles or upslope shifts to higher elevations, are rapidly accumulating. These range shifts are often attributed to species ‘tracking’ their thermal niches as temperatures in their native ranges increase. Our objective was to estimate the degree to which climate change-driven shifts in water temperature may increase the exposure of West Virginia’s native freshwater fishes to mountaintop removal surface coal mining. Mid-century shifts in habitat suitability for nine non-game West Virginia fishes were projected via Maximum Entropy species distribution modeling, using a combination of physical habitat, historical climate conditions, and future climate data. Modeling projections for a high-emissions scenario (Representative Concentration Pathway 8.5) predict that habitat suitability will increase in high elevation streams for eight of nine species, with marginal increases in habitat suitability ranging from 46-418%. We conclude that many West Virginia fishes will be at risk of increased exposure to mountaintop removal surface coal mining if climate change continues at a rapid pace

    Dedication - Dean Ralph C. Barnhart

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    Low back pain in young people : cross-sectional study in Lisbon

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    FCT (Fundação para a Ciência e a Tecnologia), IDP (Instituto do Desporto de Portugal), AIESEP World Congres

    An AC electric trap for ground-state molecules

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    We here report on the realization of an electrodynamic trap, capable of trapping neutral atoms and molecules in both low-field and high-field seeking states. Confinement in three dimensions is achieved by switching between two electric field configurations that have a saddle-point at the center of the trap, i.e., by alternating a focusing and a defocusing force in each direction. AC trapping of 15ND3 molecules is experimentally demonstrated, and the stability of the trap is studied as a function of the switching frequency. A 1 mK sample of 15ND3 molecules in the high-field seeking component of the |J,K>=|1,1> level, the ground-state of para-ammonia, is trapped in a volume of about 1 mm^3

    Chronic diabetic peripheral neuropathic pain: psychometric properties of pain and physical function outcome measures

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    © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Background: Diabetic peripheral neuropathy (DPN) not only produces severe pain, tingling, and numbness sensation in the involved limbs, but also limits physical function due to loss of sensation. There are no recommended methods for clinical situations to measure these signs and symptoms. Studies with high methodological quality use the modified Brief Pain Inventory for Diabetic Peripheral Neuropathic pain (mBPI-DPN) scale and the short form Screening of Activity Limitations and Safety Awareness (sSALSA) scale for measuring these symptoms in DPN population. In order to capture a real change in the variables of interest, the psychometric properties of that measure should be within acceptable limits. As these two measures were not assessed for all of the psychometric properties, there was a need for further evaluation. Methods: Data were collected (n = 38 patients) in a longitudinal cohort study. Test–retest reliability (0–4 weeks) and Responsiveness- Minimal Clinically Important Difference (MCID) (0–12 weeks) were calculated between two sessions. Convergent validity was assessed (between mBPI-DPN pain interference and sSALSA scale). Results: Both measures demonstrated acceptable test–retest reliability (mBPI-DPN scale: ICC = 0.61, SEM = 12.92; the sSALSA scale: ICC = 0.81, SEM = 4.88) and convergent validity (Spearman’s correlation coefficient r = 0.62). The computational methods used in different methodologies to calculate MCID for the mBPI-DPN and the sSALSA scale were varied, hence the magnitude of derived MCID scores also varied. Conclusions: Our study have provided evidence to add to the scientific basis surrounding the use of mBPI-DPN and sSALSA scales in DPN population, but standardization of these measures in a larger population is required

    Dissociable Processes of Cognitive Control during Error and Non-Error Conflicts: A Study of the Stop Signal Task

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    Conflict detection and subsequent behavioral adjustment are critical to daily life, and how this process is controlled has been increasingly of interest. A medial cortical region which includes the anterior cingulate cortex (ACC) has been theorized to act as a conflict detector that can direct prefrontal activity for behavioral adjustments. This conflict monitoring hypothesis was supported by many imaging studies of the Stroop task, with a focus on non-error processes. Here we sought to examine whether this circuit could be generalized to the stop signal task (SST), another behavioral paradigm widely used to study cognitive control. In particular, with a procedure to elicit errors in the SST, we examined whether error and non-error control were mediated by the same pathways.In functional magnetic resonance imaging of 60 healthy adults, we demonstrated that the medial cortical activity during stop success (SS) as compared to go success (G) trials is correlated with increased prefrontal activity in post-stop SS as compared to post-go SS trials, though this correlation was not specific to the medial cortical region. Furthermore, thalamic and insular rather than medial cortical activation during stop error (SE) as compared to G trials correlated with increased prefrontal activity in post-stop SS as compared to post-go SS trials.Taken together, these new findings challenge a specific role of the ACC and support distinct pathways for error and non-error conflict processing in cognitive control
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