2,891 research outputs found

    Device Identification and Authentication with Radar and UWB Ranging

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    Devices such as tablets and smart displays can be automatically unlocked when a user carrying a compatible wearable device approaches. With user permission, the event of the user being in close proximity is detected, and the user is authenticated by communicating with the wearable device using ultra-wideband (UWB) radio. However, UWB ranging can suffer from front-back ambiguity such that the detection of the presence of a user that is behind the device can unlock the device, which can lead to security and/or privacy risk. This disclosure discloses a two-pronged approach to user identification, user authentication, and front-back disambiguation during automatic unlocking of a device using UWB radio. UWB radio is used to achieve handshaking and user-profile identification. Radar is used to provide front/back information. False positives are avoided by authenticating the user when a difference between the distances reported by radar and by UWB are within a threshold

    Subject-specific finite element modelling of the human foot complex during walking: sensitivity analysis of material properties, boundary and loading conditions

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    This is the final version of the article. Available from Springer Verlag via the DOI in this record.The objective of this study was to develop and validate a subject-specific framework for modelling the human foot. This was achieved by integrating medical image-based finite element modelling, individualised multi-body musculoskeletal modelling and 3D gait measurements. A 3D ankle–foot finite element model comprising all major foot structures was constructed based on MRI of one individual. A multi-body musculoskeletal model and 3D gait measurements for the same subject were used to define loading and boundary conditions. Sensitivity analyses were used to investigate the effects of key modelling parameters on model predictions. Prediction errors of average and peak plantar pressures were below 10% in all ten plantar regions at five key gait events with only one exception (lateral heel, in early stance, error of 14.44%). The sensitivity analyses results suggest that predictions of peak plantar pressures are moderately sensitive to material properties, ground reaction forces and muscle forces, and significantly sensitive to foot orientation. The maximum region-specific percentage change ratios (peak stress percentage change over parameter percentage change) were 1.935–2.258 for ground reaction forces, 1.528–2.727 for plantar flexor muscles and 4.84–11.37 for foot orientations. This strongly suggests that loading and boundary conditions need to be very carefully defined based on personalised measurement data.This work was supported by the Grant of Biotechnology and Biological Sciences Research Council of UK (No. BB/H002782/1) and the Project of National Natural Science Foundation of China (No.51475202 and No. 51675222)

    Myeloid sarcoma with ulnar nerve entrapment: A case report

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    BACKGROUND: Myeloid sarcoma (MS) is relatively rare, occurring mainly in the skin and lymph nodes, and MS invasion of the ulnar nerve is particularly unusual. The main aim of this article is to present a case of MS invading the brachial plexus, causing ulnar nerve entrapment syndrome, and to further clinical understanding of the possibility of MS invasion of peripheral nerves. CASE SUMMARY: We present the case of a 46-year-old man with a 13-year history of well-treated acute nonlymphocytic leukaemia who was admitted to the hospital after presenting with numbness and pain in his left little finger. The initial diagnosis was considered a simple case of nerve entrapment disease, with magnetic resonance imaging showing slightly abnormal left brachial plexus nerve alignment with local thickening, entrapment, and high signal on compression lipid images. Due to the severity of the ulnar nerve compression, we surgically investigated and cleared the entrapment and nerve tissue hyperplasia; however, subsequent pathological biopsy results revealed evidence of MS. The patient had significant relief from his neurological symptoms, with no postoperative complications, and was referred to the haemato-oncology department for further consultation about the primary disease. This is the first report of safe treatment of ulnar nerve entrapment from MS. It is intended to inform hand surgeons that nerve entrapment may be associated with extramedullary MS, as a rare presenting feature of the disease. CONCLUSION: MS invasion of the brachial plexus and surrounding tissues of the upper arm, resulting in ulnar nerve entrapment and degeneration with significant neurological pain and numbness in the little finger, is uncommon. Surgical treatment significantly relieved the patient’s nerve entrapment symptoms and prevented further neurological impairment. This case is reported to highlight the rare presenting features of MS

    Beyond element-wise interactions: identifying complex interactions in biological processes

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    Background: Biological processes typically involve the interactions of a number of elements (genes, cells) acting on each others. Such processes are often modelled as networks whose nodes are the elements in question and edges pairwise relations between them (transcription, inhibition). But more often than not, elements actually work cooperatively or competitively to achieve a task. Or an element can act on the interaction between two others, as in the case of an enzyme controlling a reaction rate. We call “complex” these types of interaction and propose ways to identify them from time-series observations. Methodology: We use Granger Causality, a measure of the interaction between two signals, to characterize the influence of an enzyme on a reaction rate. We extend its traditional formulation to the case of multi-dimensional signals in order to capture group interactions, and not only element interactions. Our method is extensively tested on simulated data and applied to three biological datasets: microarray data of the Saccharomyces cerevisiae yeast, local field potential recordings of two brain areas and a metabolic reaction. Conclusions: Our results demonstrate that complex Granger causality can reveal new types of relation between signals and is particularly suited to biological data. Our approach raises some fundamental issues of the systems biology approach since finding all complex causalities (interactions) is an NP hard problem

    Cross-national agreement on disability weights: the European Disability Weights Project

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    BACKGROUND: Disability weights represent the relative severity of disease stages to be incorporated in summary measures of population health. The level of agreement on disability weights in Western European countries was investigated with different valuation methods. METHODS: Disability weights for fifteen disease stages were elicited empirically in panels of health care professionals or non-health care professionals with an academic background following a strictly standardised procedure. Three valuation methods were used: a visual analogue scale (VAS); the time trade-off technique (TTO); and the person trade-off technique (PTO). Agreement among England, France, the Netherlands, Spain, and Sweden on the three disability weight sets was analysed by means of an intraclass correlation coefficient (ICC) in the framework of generalisability theory. Agreement among the two types of panels was similarly assessed. RESULTS: A total of 232 participants were included. Similar rankings of disease stages across countries were found with all valuation methods. The ICC of country agreement on disability weights ranged from 0.56 [95% CI, 0.52–0.62] with PTO to 0.72 [0.70–0.74] with VAS and 0.72 [0.69–0.75] with TTO. The ICC of agreement between health care professionals and non-health care professionals ranged from 0.64 [0.58–0.68] with PTO to 0.73 [0.71–0.75] with VAS and 0.74 [0.72–0.77] with TTO. CONCLUSIONS: Overall, the study supports a reasonably high level of agreement on disability weights in Western European countries with VAS and TTO methods, which focus on individual preferences, but a lower level of agreement with the PTO method, which focuses more on societal values in resource allocation

    The SINS trial: A randomised controlled trial of excisional surgery versus imiquimod 5% cream for nodular and superficial basal cell carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Basal cell carcinoma is the commonest human cancer. Despite increasing incidence it remains poorly researched. While not life threatening it can cause significant cosmetic disfigurement. Imiquimod, a cream which enhances the body's immune response, may help deal with the number of cases that occur in low-risk sites, especially when good cosmetic results and home use without surgery are needed.</p> <p>This study aims 1. To compare excisional surgery with imiquimod cream for nodular or superficial basal cell carcinoma in low risk sites, with respect to 3 year clinical clearance, cost-effectiveness and cosmetic results. 2. To ascertain if certain phenotypic features and gene polymorphisms predict tumour responsiveness to treatment.</p> <p>Methods/Design</p> <p>Five hundred participants with low risk nodular or superficial basal cell carcinoma will be recruited from hospitals to this multi-centre, randomised, parallel group, controlled phase III trial. Treatment in the imiquimod group is for 6 weeks for superficial basal cell carcinoma and 12 weeks for nodular basal cell carcinoma. Both treatment groups are followed up in clinic for 3 years. Primary outcome variable: the proportion of participants with clinical evidence of success (no recurrence) at 3 years. The primary outcome will be compared between the two treatment groups. Secondary outcomes include: i) clinical success at 1, 2 and 5 years, ii) time to first recurrence, iii) cosmetic appearance of lesion site after treatment, iv) level of pain, and v) cost-effectiveness. Safety and tolerability data will also be reported.</p> <p>Discussion</p> <p>This study protocol describes a pragmatic randomised controlled trial which it is hoped will address the above uncertainties. Three-year results will be available towards the end of 2010.</p> <p>Trial registration</p> <p>Meta-register: NCT00066872, Eudract No. 2004-004506-24, ISRCTN48755084.</p

    Explicit Stabilised Gradient Descent for Faster Strongly Convex Optimisation

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    This paper introduces the Runge-Kutta Chebyshev descent method (RKCD) for strongly convex optimisation problems. This new algorithm is based on explicit stabilised integrators for stiff differential equations, a powerful class of numerical schemes that avoid the severe step size restriction faced by standard explicit integrators. For optimising quadratic and strongly convex functions, this paper proves that RKCD nearly achieves the optimal convergence rate of the conjugate gradient algorithm, and the suboptimality of RKCD diminishes as the condition number of the quadratic function worsens. It is established that this optimal rate is obtained also for a partitioned variant of RKCD applied to perturbations of quadratic functions. In addition, numerical experiments on general strongly convex problems show that RKCD outperforms Nesterov's accelerated gradient descent

    A Global Characterization and Identification of Multifunctional Enzymes

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    Multi-functional enzymes are enzymes that perform multiple physiological functions. Characterization and identification of multi-functional enzymes are critical for communication and cooperation between different functions and pathways within a complex cellular system or between cells. In present study, we collected literature-reported 6,799 multi-functional enzymes and systematically characterized them in structural, functional, and evolutionary aspects. It was found that four physiochemical properties, that is, charge, polarizability, hydrophobicity, and solvent accessibility, are important for characterization of multi-functional enzymes. Accordingly, a combinational model of support vector machine and random forest model was constructed, based on which 6,956 potential novel multi-functional enzymes were successfully identified from the ENZYME database. Moreover, it was observed that multi-functional enzymes are non-evenly distributed in species, and that Bacteria have relatively more multi-functional enzymes than Archaebacteria and Eukaryota. Comparative analysis indicated that the multi-functional enzymes experienced a fluctuation of gene gain and loss during the evolution from S. cerevisiae to H. sapiens. Further pathway analyses indicated that a majority of multi-functional enzymes were well preserved in catalyzing several essential cellular processes, for example, metabolisms of carbohydrates, nucleotides, and amino acids. What’s more, a database of known multi-functional enzymes and a server for novel multi-functional enzyme prediction were also constructed for free access at http://bioinf.xmu.edu.cn/databases/MFEs/index.htm

    Finding related sentence pairs in MEDLINE

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    We explore the feasibility of automatically identifying sentences in different MEDLINE abstracts that are related in meaning. We compared traditional vector space models with machine learning methods for detecting relatedness, and found that machine learning was superior. The Huber method, a variant of Support Vector Machines which minimizes the modified Huber loss function, achieves 73% precision when the score cutoff is set high enough to identify about one related sentence per abstract on average. We illustrate how an abstract viewed in PubMed might be modified to present the related sentences found in other abstracts by this automatic procedure
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