802 research outputs found

    Reliability of the straight leg raise test for suspected lumbar radicular pain:A systematic review with meta-analysis

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    Background: The passive straight leg raise (SLR) and crossed SLR are recommended tests for lumbar radicular pain. There are no recent reviews of test reliability. Objectives: To summarize SLR and crossed SLR reliability in patients with suspected lumbar radicular pain. Design: Systematic review with meta-analysis. Method: MEDLINE and CINAHL were searched for studies published before April 2021 that reported SLR or crossed SLR reliability in patients with low back-related leg pain. Supplemental analyses also included patients with low back pain only. Study selection, risk of bias assessment (QAREL), and data extraction were performed in duplicate. Kappa, intraclass correlation coefficients, and smallest detectable difference (SDD95) quantified reliability. Meta-analysis was performed when appropriate. Confidence in the evidence was determined by applying GRADE principles. Results/findings: Fifteen studies met selection criteria. One-hundred-eighty-nine participants had low back-related leg pain. Four-hundred-thirty-nine were included in supplemental analyses. Meta-analyses showed at least fair inter-rater reliability when a positive SLR required provocation of lower extremity symptoms or pain. SLR reliability was at least moderate when testing included structural differentiation (e.g., ankle dorsiflexion). A low prevalence of positive crossed SLR tests led to wide-ranging reliability estimates. Confidence in the evidence for identifying a positive SLR or crossed SLR was moderate to very low. SDD95 values for different raters measuring SLR range of motion ranged from 13 to 20°. Conclusions: Reliability data support testing SLR with structural differentiation manoeuvres. Crossed SLR reliability data are inconclusive. Measurement error likely prohibits using SLR range of motion for clinical decision-making

    An Application of Augmented Reality (AR) in the Teaching of an Arc Welding Robot

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    Augmented Reality (AR) is an emerging technology that utilizes computer vision methods to overlay virtual objects onto the real world scene so as to make them appear to co-exist with the real objects. Its main objective is to enhance the user’s interaction with the real world by providing the right information needed to perform a certain task. Applications of this technology in manufacturing include maintenance, assembly and telerobotics. In this paper, we explore the potential of teaching a robot to perform an arc welding task in an AR environment. We present the motivation, features of a system using the popular ARToolkit package, and a discussion on the issues and implications of our research.Singapore-MIT Alliance (SMA

    Management and Rehabilitation Strategies Following IED Related Mild Traumatic Brain Injury in Civilian Settings - What to Expect and How to Optimize Recovery From mTBI

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    The wide array of psychological and physical responses following an IED bombing may reduce the likelihood that appropriate assessment and recovery from mTBI occur. Such a situation is problematic as mTBI itself may negatively influence the recovery from the traumatic event or associated injuries if not diagnosed and managed properly. Consequently, the overall aim of this article is to better inform healthcare practitioners, patients, and patients’ social support networkabout the nature of IED-related mild traumatic brain injuries. In so doing, we hope to facilitate enhanced assessment, management, and rehabilitation of this injury. In particular, the specific goals of the review include: (i) a description of the nature of an IED-related mTBI in a civilian setting (section 2 to 2.3); (ii) a description of the unique circumstances for mTBI survivors in regards to the signs and symptoms that may be anticipated (section 2.4); (iii) what key stakeholders including: the rehabilitant, the managing health care team, and social support providers (e.g., family members) can expect in terms of the physical and emotional recovery process (sections 3 to 4.4.) Finally, general and specific lifestyle modifications to improve survivors’ health are described in order to lay a clear foundation for patients’ recovery from an IED-related mTBI

    Network effects, cooperation and entrepreneurial innovation in China

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    The rapid rise of an innovative private manufacturing economy in China challenges standard economic explanations of growth, which typically assume the existence of well-defined formal institutions such as property rights and company laws safeguarding investor and creditor interests. We highlight the social structure of cooperation that enables innovative activity in private manufacturing firms when formal property rights protection remains weak. We show how network effects linked to inter-firm cooperation in industrial clusters allowed private entrepreneurs to quickly develop reliable business norms to reduce the inherent risk of malfeasance and contract breach in formal and informal collaborative efforts. Survey data from a sample of 700 manufacturing firms located in China’s Yangzi Delta region confirms that both formal and informal types of inter-firm collaboration are effective, though in different areas of innovative activity

    Species Abundance Patterns in Complex Evolutionary Dynamics

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    An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g. gene expression.Comment: 4 pages, 3 figures. Physical Review Letters, in pres

    Utilization of the Clinical Laboratory for the Implementation of Concussion Biomarkers in Collegiate Football and the Necessity of Personalized and Predictive Athlete Specific Reference Intervals

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    Background: A continued interest in concussion biomarkers makes the eventual implementation of identified biomarkers into routine concussion assessment an eventual reality. We sought to develop and test an interdisciplinary approach that could be used to integrate blood-based biomarkers into the established concussion management program for a collegiate football team. Methods: We used a CLIA-certified laboratory for all testing and chose biomarkers where clinically validated testing was available as would be required for results used in clinical decision making. We summarized the existing methods and results for concussion assessment across an entire season to identify and demonstrate the challenges with the eventual integration of a parallel process using blood-based tests for concussion management. We analyzed the results of the biomarkers chosen for trends consistent with the outcome assessments provided from the current concussion management protocols. Results: Baseline samples were collected with three additional post-concussion samples collected at three separate time points from players with a diagnosed concussion (n = 12). A summary of results from currently used concussion assessment tools were compared to the representative biomarkers S100B and NSE results. Nine sport-related concussions occurred during practice and three during play. For S100B, 50 % had follow-up testing results lower than the post-injury result. In contrast, 92 % of NSE follow-up results were lower than post-injury. One hundred percent of the results for S100B and NSE were within the athlete-derived reference intervals upon return-to-play and season end. Conclusions: The reported workflow provides a framework for the eventual implementation of biomarkers for concussion assessment into existing assessment protocols and strengthens the need for reliance on clinical laboratory testing. Athlete-specific reference intervals will be required to adequately interpret results

    Patients’ experiences treated with open-label placebo versus double-blind placebo: a mixed methods qualitative study

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    Background: There is increasing evidence suggesting that open-label placebo (OLP) is an effective treatment for several medical conditions defined by self-report. However, little is known about patients’ experiences with OLP, and no studies have directly compared patients’ experiences in double-blind placebo (DBP) conditions. Methods: This study was nested in a large randomized-controlled trial comparing the effects of OLP and DBP treatments in individuals with irritable bowel syndrome (IBS). We randomly selected 33 participants for interviews concerning their experiences in the parent trial. The data were qualitatively analyzed using an iterative immersion/crystallization approach. We then compared the qualitative interview data to the quantitative IBS severity data assessed during the parent trial, using a mixed methods approach. Results: Two prominent interview themes were identified: (1) the participants’ feelings about their treatment allocation and (2) their reflections about the treatment. Both OLP and DBP participants mentioned hope and curiosity as major feelings driving them to engage with their treatment. However, while DBP participants tended to be more enthusiastic about their allocation, OLP participants were more ambivalent. Furthermore, OLP participants reflected more on their treatment, often involving noticeable cognitive and emotional processes of self-reflection. They offered a variety of explanations for their symptom improvement and were significantly less likely to attribute it to the treatment itself than DBP participants (Χ2 [3] = 8.28; p =.041). Similarly, the participants’ retrospective narratives of symptom improvement were significantly correlated with their corresponding quantitative IBS severity scores only in DBP (p’s ≤.006) but not in OLP (p’s ≥.637). Conclusion: OLP and DBP participants share feelings of hope, uncertainty and curiosity but differ in the extent of conscious reflection. The counter-intuitive OLP prompts more self-examination, ambivalent feelings and active engagement compared to DBP. At the same time, OLP participants are more reluctant to attribute symptom improvement to their treatment. Our findings substantially add to the emerging picture of factors that distinguish OLP and DBP and their potential mechanisms

    Surfaces roughness effects on the transmission of Gaussian beams by anisotropic parallel plates

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    Influence of the plate surfaces roughness in precise ellipsometry experiments is studied. The realistic case of a Gaussian laser beam crossing a uniaxial platelet is considered. Expression for the transmittance is determined using the first order perturbation theory. In this frame, it is shown that interference takes place between the specular transmitted beam and the scattered field. This effect is due to the angular distribution of the Gaussian beam and is of first order in the roughness over wavelength ratio. As an application, a numerical simulation of the effects of quartz roughness surfaces at normal incidence is provided. The interference term is found to be strongly connected to the random nature of the surface roughness.Comment: 18 pages, Journal of Physics D: Applied Physics, volume 36, issue 21, pages 2697 - 270

    Andreev Reflection in Strong Magnetic Fields

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    We have studied the interplay of Andreev reflection and cyclotron motion of quasiparticles at a superconductor-normal-metal interface with a strong magnetic field applied parallel to the interface. Bound states are formed due to the confinement introduced both by the external magnetic field and the superconducting gap. These bound states are a coherent superposition of electron and hole edge excitations similar to those realized in finite quantum-Hall samples. We find the energy spectrum for these Andreev edge states and calculate transport properties.Comment: 5 pages, 3 figures, RevTex, revised to include more detailed discussion of currents and transpor
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