242 research outputs found

    Discovering Differences in Acoustic Emission Between Healthy and Osteoarthritic Knees Using a Four-Phase Model of Sit-Stand-Sit Movements

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    By performing repeated sit-stand-sit movements to create stress on knee joints, short transient bursts of high frequency acoustic emission (AE) released by the knee joints were acquired from two age matched groups consisting of healthy and osteoarthritic (OA) knees, and significant differences between these two groups were discovered from the signal analysis performed. The analysis is based on a four-phase model of sit-stand-sit movements and a two-feature descriptor of AE bursts. The four phases are derived from joint angle measurement during movement, and they consist of the ascending-acceleration and ascending-deceleration phases in the sit-to-stand movement, followed by the descending-acceleration and descending-deceleration phases in the stand-to-sit movement. The two features are extracted from AE measurement during movement, and they consist of the peak magnitude value and average signal level of each AE burst. The proposed analysis method is shown to provide a high sensitivity for differentiation of the two age matched healthy and OA groups, with the most significant difference found to come from the peak magnitude value in the ascending-deceleration phase, clear quantity and strength differences in the image based visual display of their AE feature profiles due to substantially more AE bursts from OA knee joints with higher peak magnitude values and higher average signal levels, and two well separated clusters in the space formed by the principal components. These results provide ample support for further development of AE as a novel tool to facilitate dynamic integrity assessment of knee joints in clinic and home settings

    Can long-range PCR be used to amplify genetically divergent mitochondrial genomes for comparative phylogenetics?: a case study within spiders (Arthropoda: Araneae)

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    The development of second generation sequencing technology has resulted in the rapid production of large volumes of sequence data for relatively little cost, thereby substantially increasing the quantity of data available for phylogenetic studies. Despite these technological advances, assembling longer sequences, such as that of entire mitochondrial genomes, has not been straightforward. Existing studies have been limited to using only incomplete or nominally intra-specific datasets resulting in a bottleneck between mitogenome amplification and downstream high-throughput sequencing. Here we assess the effectiveness of a wide range of targeted long-range PCR strategies, encapsulating single and dual fragment primer design approaches to provide full mitogenomic coverage within the Araneae (Spiders). Despite extensive rounds of optimisation, full mitochondrial genome PCR amplifications were stochastic in most taxa, although 454 Roche sequencing confirmed the successful amplification of 10 mitochondrial genomes out of the 33 trialled species. The low success rates of amplification using long-Range PCR highlights the difficulties in consistently obtaining genomic amplifications using currently available DNA polymerases optimised for large genomic amplifications and suggests that there may be opportunities for the use of alternative amplification methods

    Rapid and quantitative detection of the microbial spoilage of meat by Fourier Transform Infrared Spectroscopy and machine learning

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    Fourier transform infrared (FT-IR) spectroscopy is a rapid, noninvasive technique with considerable potential for application in the food and related industries. We show here that this technique can be used directly on the surface of food to produce biochemically interpretable “fingerprints.” Spoilage in meat is the result of decomposition and the formation of metabolites caused by the growth and enzymatic activity of microorganisms. FT-IR was exploited to measure biochemical changes within the meat substrate, enhancing and accelerating the detection of microbial spoilage. Chicken breasts were purchased from a national retailer, comminuted for 10 s, and left to spoil at room temperature for 24 h. Every hour, FT-IR measurements were taken directly from the meat surface using attenuated total reflectance, and the total viable counts were obtained by classical plating methods. Quantitative interpretation of FT-IR spectra was possible using partial least-squares regression and allowed accurate estimates of bacterial loads to be calculated directly from the meat surface in 60 s. Genetic programming was used to derive rules showing that at levels of 10(7) bacteria·g(−1) the main biochemical indicator of spoilage was the onset of proteolysis. Thus, using FT-IR we were able to acquire a metabolic snapshot and quantify, noninvasively, the microbial loads of food samples accurately and rapidly in 60 s, directly from the sample surface. We believe this approach will aid in the Hazard Analysis Critical Control Point process for the assessment of the microbiological safety of food at the production, processing, manufacturing, packaging, and storage levels

    The 3Mg trial: A randomised controlled trial of intravenous or nebulised magnesium sulphate versus placebo in adults with acute severe asthma

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    Background: Magnesium sulphate, administered by the intravenous (i.v.) or inhaled (nebulised) route, has been proposed as a treatment for adults with acute severe asthma. Existing trials show mixed results and uncertain evidence of benefit. Objectives: We aimed to determine whether i.v. or nebulised magnesium sulphate improves symptoms of breathlessness and reduces the need for hospital admission in adults with acute severe asthma. Design: Multicentre, double-blind, placebo-controlled, three-arm, randomised trial. Setting: The emergency departments of 34 acute hospitals in the UK. Participants: We recruited 1109 adults (age > 16 years) with acute severe asthma [peak expiratory flow rate (PEFR) 25 breaths per minute, heart rate > 110 beats per minute or inability to complete sentences in one breath]. Patients with life-threatening features or a contraindication to either nebulised or intravenous magnesium sulphate were excluded. Interventions: Participants were randomly allocated to i.v. magnesium sulphate (2 g over 20 minutes) or nebulised magnesium sulphate (3 × 500 mg over 1 hour) or standard therapy alone. Main outcome measures: The primary outcome was the proportion of patients admitted to hospital (either after emergency department treatment or at any time over the subsequent 7 days) and breathlessness measured on a 100-mm visual analogue scale (VAS) over 2 hours after initiation of treatment. Results: We randomised 406 patients to i.v. magnesium sulphate, 339 to nebulised magnesium sulphate and 364 to placebo. Hospital admission was recorded for 394, 332 and 358 patients, respectively, and VAS breathlessness for 357, 296 and 323 patients respectively. Mean age was 36.1 years and 763 out of 1084 (70%) patients were female. Intravenous magnesium sulphate was associated with an odds ratio (OR) of 0.73 [95% confidence interval (CI) 0.51 to 1.04; p = 0.083] for hospital admission, an improvement in VAS breathlessness that was 2.6mm (95% CI -1.6 to 6.8 mm; p = 0.231) greater than that associated with placebo and an improvement in PEFR that was 2.4 l/minute (95% CI -8.8 to 13.6 l/minute; p = 0.680) greater than that associated with placebo. Nebulised magnesium sulphate was associated with an OR of 0.96 (95% CI 0.65 to 1.40; p = 0.819) for hospital admission, an improvement in VAS breathlessness that was 2.6mm (95% CI -1.8mm to 7.0 mm; p = 0.253) less than that associated with placebo and an improvement in PEFR that was 2.6 l/minute (95% CI -9.2 to 14.5 l/minute; p = 0.644) less than that associated with placebo. There were no significant differences between i.v. or nebulised magnesium sulphate and placebo for any other outcomes. The number (%) of patients reporting any side effect was 61 (15.5%) in the i.v. group, 52 (15.7%) in the nebuliser group and 36 (10.1%) in the placebo group. The ORs for suffering any side effect were 1.68 (95% CI 1.07 to 2.63; p = 0.025) for i.v. compared with placebo and 1.67 (95% CI 1.05 to 2.66; p = 0.031) for nebuliser compared with placebo. Conclusions: We were unable to demonstrate a clinically worthwhile benefit from magnesium sulphate in acute severe asthma. There was some weak evidence of an effect of i.v. magnesium sulphate on hospital admission, but no evidence of an effect on VAS breathlessness or PEFR compared with placebo. We found no evidence that nebulised magnesium sulphate was more effective than placebo. Trial registration: Current Controlled Trials ISRCTN04417063. Source of funding: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 22. See the NIHR Journals Library programme website for further project information. © Queen's Printer and Controller of HMSO 2014

    Designing an Exascale Interconnect using Multi-objective Optimization

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    Exascale performance will be delivered by systems composed of millions of interconnected computing cores. The way these computing elements are connected with each other (network topology) has a strong impact on many performance characteristics. In this work we propose a multi-objective optimizationbased framework to explore possible network topologies to be implemented in the EU-funded ExaNeSt project. The modular design of this system’s interconnect provides great flexibility to design topologies optimized for specific performance targets such as communications locality, fault tolerance or energyconsumption. The generation procedure of the topologies is formulated as a three-objective optimization problem (minimizing some topological characteristics) where solutions are searched using evolutionary techniques. The analysis of the results, carried out using simulation, shows that the topologies meet the required performance objectives. In addition, a comparison with a well-known topology reveals that the generated solutions can provide better topological characteristics and also higher performance for parallel applications

    Discovering Associations between Acoustic Emission and Magnetic Resonance Imaging Biomarkers from 10 Osteoarthritic Knees

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    Objective: Acoustic emission (AE) sensed from knee joints during weight-bearing movements greatly increases with joint deterioration, but the relationship between AE patterns and specific anatomical damage, as seen for example in magnetic resonance imaging (MRI), is unknown. This knowledge is essential to validate AE biomarkers for the evaluation of knee joints, and forms the objective of this exploratory work to associate knee AE and MRI. Methods: A novel processing framework is proposed to enable direct correlation between static 3D MRI of knees and their dynamic 1D AE during sit-stand-sit movements. It comprises a method to estimate articular cartilage thickness according to joint angle from knee MRI, and a method to derive statistically representative waveform features according to joint angle from movement and load-dependent knee AE. Results: In 10 subjects diagnosed with knee osteoarthritis, age 55~79 years and body mass index 25~35 kg/m2, a strong inverse relationship between knee AE and cartilage thickness in the medial tibiofemoral compartment around the fully standing position was observed. Knees with thinner articular cartilage generated more AE with higher amplitude, greater energy, longer duration, and higher frequencies, in agreement with the assumption of more intense articulation friction under full body weight. Conclusion: AE provides promising quantitative biomarkers in knee joint disease. Significance: These findings provide impetus for the further development of AE as a low-cost non-invasive biomarker modality to improve the management of knee joint disease

    Single Event Effects Assessment of UltraScale+ MPSoC Systems under Atmospheric Radiation

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    The AMD UltraScale+ XCZU9EG device is a Multi-Processor System-on-Chip (MPSoC) with embedded Programmable Logic (PL) that excels in many Edge (e.g., automotive or avionics) and Cloud (e.g., data centres) terrestrial applications. However, it incorporates a large amount of SRAM cells, making the device vulnerable to Neutron-induced Single Event Upsets (NSEUs) or otherwise soft errors. Semiconductor vendors incorporate soft error mitigation mechanisms to recover memory upsets (i.e., faults) before they propagate to the application output and become an error. But how effective are the MPSoC's mitigation schemes? Can they effectively recover upsets in high altitude or large scale applications under different workloads? This article answers the above research questions through a solid study that entails accelerated neutron radiation testing and dependability analysis. We test the device on a broad range of workloads, like multi-threaded software used for pose estimation and weather prediction or a software/hardware (SW/HW) co-design image classification application running on the AMD Deep Learning Processing Unit (DPU). Assuming a one-node MPSoC system in New York City (NYC) at 40k feet, all tested software applications achieve a Mean Time To Failure (MTTF) greater than 148 months, which shows that upsets are effectively recovered in the processing system of the MPSoC. However, the SW/HW co-design (i.e., DPU) in the same one-node system at 40k feet has an MTTF = 4 months due to the high failure rate of its PL accelerator, which emphasises that some MPSoC workloads may require additional NSEU mitigation schemes. Nevertheless, we show that the MTTF of the DPU can increase to 87 months without any overhead if one disregards the failure rate of tolerable errors since they do not affect the correctness of the classification output.Comment: This manuscript is under review at IEEE Transactions on Reliabilit

    A 5 item version of the Compliance Questionnaire for Rheumatology (CQR5) successfully identifies low adherence to DMARDs

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    © 2013 Hughes et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedTaking DMARDs as prescribed is an essential part of self-management for patients with Rheumatoid Arthritis. To date, the Compliance Questionnaire for Rheumatology (CQR) is the only self-report adherence measure created specifically for and validated in rheumatic diseases. However, the factor structure of the CQR has not been reported and it can be considered lengthy at 19 items. The aim of this study was to test the factor structure of the CQR and reduce the number of items whilst retaining robust explanation of non-adherence to DMARDs. Such a reduction would increase the clinical utility of the scale, to identify patients with sub-optimal adherence to DMARDs in the clinic as well as for research purposes.Peer reviewe
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