2,864 research outputs found

    Self-controlled feedback facilitates motor learning in both high and low activity individuals

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    The purpose of this study was to determine if high and low activity individuals differed in terms of the effects of self-controlled feedback on the performance and learning of a movement skill. The task consisted of a blindfolded beanbag toss using the non-preferred arm. Participants were pre-screened according to their physical activity level using the International Physical Activity Questionnaire. An equal number of high activity (HA) and low activity (LA) participants were assigned to self-control (SC) and yoked (YK) feedback conditions, creating four groups: Self-Control-High Activity; Self-Control-Low Activity; Yoked-High Activity; and Yoked-Low Activity. SC condition participants were provided feedback whenever they requested it, while YK condition participants received feedback according to a schedule created by their SC counterpart. Results indicated that the SC condition was more accurate than the YK condition during acquisition and transfer phases, and the HA condition was more accurate than the LA condition during all phases of the experiment. A post-training questionnaire indicated that participants in the SC condition asked for feedback mostly after what they perceived to be “good” trials; those in the YK condition indicated that they would have preferred to receive feedback after “good” trials. This study provided further support for the advantages of self-controlled feedback when learning motor skills, additionally showing benefits for both active and less active individuals. The results suggested that the provision of self-controlled feedback to less active learners may be a potential avenue to teaching motor skills necessary to engage in greater amounts of physical activity

    Two Weeks of Ischemic Conditioning Improves Walking Speed and Reduces Neuromuscular Fatigability in Chronic Stroke Survivors

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    This pilot study examined whether ischemic conditioning (IC), a noninvasive, cost-effective, and easy-to-administer intervention, could improve gait speed and paretic leg muscle function in stroke survivors. We hypothesized that 2 wk of IC training would increase self-selected walking speed, increase paretic muscle strength, and reduce neuromuscular fatigability in chronic stroke survivors. Twenty-two chronic stroke survivors received either IC or IC Sham on their paretic leg every other day for 2 wk (7 total sessions). IC involved 5-min bouts of ischemia, repeated five times, using a cuff inflated to 225 mmHg on the paretic thigh. For IC Sham, the cuff inflation pressure was 10 mmHg. Self-selected walking speed was assessed using the 10-m walk test, and paretic leg knee extensor strength and fatigability were assessed using a Biodex dynamometer. Self-selected walking speed increased in the IC group (0.86 ± 0.21 m/s pretest vs. 1.04 ± 0.22 m/s posttest, means ± SD; P\u3c 0.001) but not in the IC Sham group (0.92 ± 0.47 m/s pretest vs. 0.96 ± 0.46 m/s posttest; P= 0.25). Paretic leg maximum voluntary contractions were unchanged in both groups (103 ± 57 N·m pre-IC vs. 109 ± 65 N·m post-IC; 103 ± 59 N·m pre-IC Sham vs. 108 ± 67 N·m post-IC Sham; P = 0.81); however, participants in the IC group maintained a submaximal isometric contraction longer than participants in the IC Sham group (278 ± 163 s pre-IC vs. 496 ± 313 s post-IC, P = 0.004; 397 ± 203 s pre-IC Sham vs. 355 ± 195 s post-IC Sham; P = 0.46). The results from this pilot study thus indicate that IC training has the potential to improve walking speed and paretic muscle fatigue resistance poststroke

    MYSEA Testbed

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    The technical vision of the emerging net-centric Global Information Grid (GIG) encompasses support for high assurance authentication and multilevel security (MLS) as well as flexible, dynamic security policies. The GIG is intended to address the inefficient exchange of information in current military and intelligence operations that utilize a variety of specialized (so-called "stove-piped") systems. In this context, secure information access problems are exacerbated by the need to share information from networks at different classifications (e.g., Unclassified, Secret, and Top Secret) and within multinational coalitions in episodic, ad hoc situations. These challenges provide the impetus for the creation of the Monterey Security Architecture (MYSEA) Testbed. The purpose of this Testbed is to support research in high assurance multilevel security (MLS) [1, 2] and dynamic security, two areas that are critical to the realization of the GIG's assured information sharing vision.Approved for public release; distribution is unlimited

    Post-cataract outcomes in patients with noninfectious posterior uveitis treated with the fluocinolone acetonide intravitreal implant

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    PURPOSE: To describe visual acuity (VA) and inflammation following cataract surgery in eyes with noninfectious posterior uveitis (NIPU) that were being treated with a fluocinolone acetonide (FA) intravitreal implant compared with those that were not. DESIGN: Post hoc, subgroup analysis of data from a 3-year, dose-masked, randomized, multicenter trial evaluating the FA implant for the treatment of NIPU. PARTICIPANTS AND CONTROLS: The subset of eyes that underwent cataract surgery during the 3-year trial. Eyes were either implanted with a 0.59- or a 2.1-mg FA implant, or, in the case of affected fellow eyes, received standard-of-care local treatment. MAIN OUTCOME MEASURES: VA, anterior and posterior chamber inflammation at 1 and 3 months after surgery, and rate of uveitis recurrence and serious postoperative ocular adverse events. RESULTS: Of 278 patients enrolled in the main trial, 132/142 phakic implanted eyes and 39/186 phakic non-implanted eyes underwent cataract surgery. Mean improvement in VA was significantly greater in implanted than non-implanted eyes at 1 (P = 0.0047) and 3 months (P = 0.0015) postoperatively; significantly fewer anterior chamber cells were seen in implanted than non-implanted eyes at 1 (P = 0.0084) and 3 months (P = 0.0002). Severity of vitreous haze was less in implanted than non-implanted eyes at 3 months postoperatively (P = 0.0005). The postsurgical uveitis recurrence rate was lower in implanted than non-implanted eyes (26.5% vs 44.4%; P = 0.0433). Glaucoma was reported in 19.7% of implanted eyes and no non-implanted eyes (P = 0.0008) postoperatively. CONCLUSION: In this post hoc subgroup analysis, eyes with NIPU treated with the FA intravitreal implant demonstrated better vision and less intraocular inflammation following cataract surgery than non-implanted eyes. Recurrent uveitic inflammation did not appear to be triggered by cataract surgery. Glaucoma occurred more frequently in implanted eyes

    A Cloud-Oriented Cross-Domain Security Architecture

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    The Monterey Security Architecture addresses the need to share high-value data across multiple domains of different classification levels while enforcing information flow policies. The architecture allows users with different security authorizations to securely collaborate and exchange information using commodity computers and familiar commercial client software that generally lack the prerequisite assurance and functional security protections. MYSEA seeks to meet two compelling requirements, often assumed to be at odds: enforcing critical, mandatory security policies, and allowing access and collaboration in a familiar work environment. Recent additions to the MYSEA design expand the architecture to support a cloud of cross-domain services, hosted within a federation of multilevel secure (MLS) MYSEA servers. The MYSEA cloud supports single-sign on, service replication, and network-layer quality of security service. This new cross domain, distributed architecture follows the consumption and delivery model for cloud services, while maintaining the federated control model necessary to support and protect cross domain collaboration within the enterprise. The resulting architecture shows the feasibility of high-assurance, cross-domain services hosted within a community cloud suitable for interagency, or joint, collaboration. This paper summarizes the MYSEA architecture and discusses MYSEA's approach to provide an MLS-constrained cloud computing environment.Approved for public release; distribution is unlimited

    Data evidencing slow anaerobic digestion in emergency treatment and disposal of infectious animal carcasses

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    Burial of infectious and potentially infectious livestock and poultry animals is the most common response to an emergency situation. The data set summarizes 22-week-long experiment that simulates the environment found within conventional burial trenches for emergency disposal of animal carcasses, worldwide, sometimes with a topical application of quicklime as it is required in the Republic of Korea. This data set shows the rarely presented evidence of the extremely slow decay of animal carcasses. Besides visual evidence of no visible breakdown of carcass material, i.e., carcass (or carcass quarters and coarse cuts) still resembled the initial material at the end of the study, we present data characterizing the process. Specifically, temporal variations of digestate quality (pH, ammonia, volatile fatty acids), biogas production, and the persistence of odorous volatile organic compounds are summarized. The data provide important evidence of undesirable, slow progression of the digestion process. The evidence of failure to achieve practical endpoints with the anaerobic digestion provides the impetus for seeking alternative, improved methods of disposal that will be feasible in emergency context, such as aerated burial concept (Koziel et al., 2018 [1])

    Method for sampling and analysis of volatile biomarkers in process gas from aerobic digestion of poultry carcasses using time-weighted average SPME and GC–MS

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    A passive sampling method, using retracted solid-phase microextraction (SPME) – gas chromatography–mass spectrometry and time-weighted averaging, was developed and validated for tracking marker volatile organic compounds (VOCs) emitted during aerobic digestion of biohazardous animal tissue. The retracted SPME configuration protects the fragile fiber from buffeting by the process gas stream, and it requires less equipment and is potentially more biosecure than conventional active sampling methods. VOC concentrations predicted via a model based on Fick’s first law of diffusion were within 6.6–12.3% of experimentally controlled values after accounting for VOC adsorption to the SPME fiber housing. Method detection limits for five marker VOCs ranged from 0.70 to 8.44 ppbv and were statistically equivalent (p \u3e 0.05) to those for active sorbent-tube-based sampling. The sampling time of 30 min and fiber retraction of 5 mm were found to be optimal for the tissue digestion process

    Toward an understanding of tourists’ authentic heritage experiences: Evidence from Hong Kong

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    Authenticity in tourism has been a topic of discussion since the 1960s, but the concept is still to be fully developed. This study focuses on tourists’ perceptions of authenticity, and in particular how they evaluate authentic heritage experiences. The appearance and physical settings of attractions were found to be the initial and most important indicators of authentic or inauthentic experiences. Other criteria for assessing the authenticity of heritage experiences include the presence of local culture and customs, constructed elements, commodification, and atmosphere
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