5,209 research outputs found

    Personalised meta-learning for human activity recognition with few-data.

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    State-of-the-art methods of Human Activity Recognition(HAR) rely on a considerable amount of labelled data to train deep architectures. This becomes prohibitive when tasked with creating models that are sensitive to personal nuances in human movement, explicitly present when performing exercises and when it is infeasible to collect training data to cover the whole target population. Accordingly, learning personalised models with few data remains an open challenge in HAR research. We present a meta-learning methodology for learning-to-learn personalised models for HAR; with the expectation that the end-user only need to provide a few labelled data. These personalised HAR models benefit from the rapid adaptation of a generic meta-model using provided few end-user data. We implement the personalised meta-learning methodology with two algorithms, Personalised MAML and Personalised Relation Networks. A comparative study shows significant performance improvements against state-of-the-art deep learning algorithms and other personalisation algorithms in multiple HAR domains. Also, we show how personalisation improved meta-model training, to learn a generic meta-model suited for a wider population while using a shallow parametric model

    Microwave Oscillations of a Nanomagnet Driven by a Spin-Polarized Current

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    We describe direct electrical measurements of microwave-frequency dynamics in individual nanomagnets that are driven by spin transfer from a DC spin-polarized current. We map out the dynamical stability diagram as a function of current and magnetic field, and we show that spin transfer can produce several different types of magnetic excitations, including small-angle precession, a more complicated large-angle motion, and a high-current state that generates little microwave signal. The large-angle mode can produce a significant emission of microwave energy, as large as 40 times the Johnson-noise background.Comment: 12 pages, 3 figure

    Sodium and Potassium Excretion of Schoolchildren and Relationship with Their Family Excretion in China.

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    This cross-sectional study aimed to assess 24-h urinary sodium and potassium excretion in children and the relationships with their family excretion. Using the baseline data of a randomized trial conducted in three cities of China in 2018, a total of 590 children (mean age 8.6 ± 0.4 years) and 1180 adults (mean age 45.8 ± 12.9 years) from 592 families had one or two complete 24-h urine collections. The average sodium, potassium excretion and sodium-to-potassium molar ratio of children were 2180.9 ± 787.1 mg/d (equivalent to 5.5 ± 2.0 g/d of salt), 955.6 ± 310.1 mg/d and 4.2 ± 1.7 respectively, with 77.1% of the participants exceeding the sodium recommendation and 100% below the proposed potassium intake. In mixed models adjusting for confounders, every 1 mg/d increase in sodium excretion of adult family members was associated with a 0.11 mg/d (95% CI: 0.06 to 0.16, p < 0.0001) increase in sodium excretion of children. The family-child regression coefficient corresponds to 0.20 mg/d (95% CI: 0.15 to 0.26, p < 0.0001) per 1 mg/d in potassium and to 0.36 (95% CI: 0.26 to 0.45, p < 0.0001) in sodium-to-potassium molar ratio. Children in China are consuming too much sodium and significantly inadequate potassium. The sodium, potassium excretion and sodium-to-potassium ratio of children are associated with their family excretions in small to moderate extent. Efforts are warranted to support salt reduction and potassium enhancement in children through comprehensive strategies engaging with families, schools and food environments

    Comprehensive workplace intervention for cancer prevention in China (WECAN): protocol for a stepped-wedge, cluster-randomised controlled trial.

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    INTRODUCTION: Cancer is the second leading cause of death across the globe with the majority of deaths occurring in low-income and middle-income countries. Evidence has shown that the cancer burden can be substantially reduced by avoiding behavioural risk factors through comprehensive intervention strategies, including workplace health promotion, which has shown to be cost-effective in developed countries while rarely conducted in developing countries. This study aims to explore a feasible and sustainable approach to the prevention and control of cancer in China by developing an evidence-based comprehensive workplace health model equipped with a smartphone application for implementation. METHODS AND ANALYSIS: This study is designed as a stepped-wedge, cluster-randomised controlled trial. We will recruit 15 workplaces from three cities in China. A total of 750 employees will be randomly selected for evaluation that includes five rounds of survey conducted every 6 months. After the second evaluation, workplaces will be randomly allocated to start the intervention sequentially every 6 months in three steps with five workplaces per step. A mobile application 'Healthy Workplace' will be developed to support the intervention. On-line and off-line health-related activities will be carried out among employees. Employers will provide supportive policies, environment and benefits to facilitate the adoption of healthy behaviours. The primary outcome is the change of Healthy Lifestyle Index Score, which consists of five components including smoking, alcohol drinking, physical activity, diet and body mass index. ETHICS AND DISSEMINATION: The study has been approved by Queen Mary University of London Ethics of Research Committee (QMERC22.257) and Chinese Centre for Disease Control and Prevention Institutional Review Board (202210). Written informed consent is required from all participants. Results will be disseminated through presentations, publications and social media. TRIAL REGISTRATION NUMBER: ChiCTR2200058680

    Influence of opioids on immune function in patients with cancer pain: from bench to bedside

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    In patients with cancer, opioids are principally used for the management of acute surgical and chronic cancer-related pain. However, opioids have many non-analgesic effects, including direct and indirect effects on cancer cells and on anti-tumour immunity (NK cells, macrophages and T-cells). Direct effects on immune cells are manifested via opioid and non-opioid toll-like receptors, whereas indirect effects are manifested via the sympathetic nervous system and hypothalamic–pituitary–adrenal axis. Opioids can also decrease/alter immune cell infiltration into the tumour micro-environment. Animal models have shown that this is not a class effect, in that morphine and fentanyl suppress NK cell cytotoxicity; buprenorphine does not affect NK cell cytotoxicity, whereas tramadol increases NK cell cytotoxicity, reducing metastasis. In healthy individuals, morphine suppresses and fentanyl enhances NK cell cytotoxicity. In patients undergoing surgery, fentanyl decreased and tramadol increased NK cell cytotoxicity; clinical outcomes were not determined. Meta-analyses of opioid-sparing surgical studies report an association between improved recurrence-free and/or overall survival with regional/neuraxial anaesthesia compared with systemic opioids. In patients receiving opioids for non-surgical cancer-related pain, morphine has variable effects on immunity; clinical outcomes were not assessed. Although there is a potential association between systemic opioid administration and shorter survival in cancer patients with a prognosis of months to years, studies have not been designed to primarily assess survival, as a consequence of which causality cannot be apportioned. Pain is immunosuppressive, so analgesia is important. Opioids for cancer-related pain will continue to be recommended until definitive data on the effects of opioids on clinical outcomes in specific patient groups becomes available

    The ubiquitin-conjugating enzyme HR6B is required for maintenance of X chromosome silencing in mouse spermatocytes and spermatids

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    <p>Abstract</p> <p>Background</p> <p>The ubiquitin-conjugating enzyme HR6B is required for spermatogenesis in mouse. Loss of HR6B results in aberrant histone modification patterns on the trancriptionally silenced X and Y chromosomes (XY body) and on centromeric chromatin in meiotic prophase. We studied the relationship between these chromatin modifications and their effects on global gene expression patterns, in spermatocytes and spermatids.</p> <p>Results</p> <p>HR6B is enriched on the XY body and on centromeric regions in pachytene spermatocytes. Global gene expression analyses revealed that spermatid-specific single- and multicopy X-linked genes are prematurely expressed in <it>Hr6b </it>knockout spermatocytes. Very few other differences in gene expression were observed in these cells, except for upregulation of major satellite repeat transcription. In contrast, in <it>Hr6b </it>knockout spermatids, 7298 genes were differentially expressed; 65% of these genes was downregulated, but we observed a global upregulation of gene transcription from the X chromosome. In wild type spermatids, approximately 20% of the single-copy X-linked genes reach an average expression level that is similar to the average expression from autosomes.</p> <p>Conclusions</p> <p>Spermatids maintain an enrichment of repressive chromatin marks on the X chromosome, originating from meiotic prophase, but this does not interfere with transcription of the single-copy X-linked genes that are reactivated or specifically activated in spermatids. HR6B represses major satellite repeat transcription in spermatocytes, and functions in the maintenance of X chromosome silencing in spermatocytes and spermatids. It is discussed that these functions involve modification of chromatin structure, possibly including H2B ubiquitylation.</p

    A town level comprehensive intervention study to reduce salt intake in China: protocol for a cluster randomised controlled trial.

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    INTRODUCTION: Salt intake in China (≈12 g/day) is more than twice the upper limit recommended by the WHO (5 g/day). To reduce salt intake, Action on Salt China (ASC) was launched in 2017. As one of four randomised controlled trials (RCTs) in the ASC programme, a comprehensive intervention study was designed to test whether all the components of the interventions adopted by other RCTs are acceptable, scalable and effective when provided to a region in the real world. METHODS AND ANALYSIS: Using a cluster RCT design, 2688 participants were selected from 48 towns (clusters) in 12 counties in 6 provinces and assigned to the intervention group or the control group. Randomisation was performed after the baseline survey was completed. Information on salt-related knowledge, attitude and practice (KAP), blood pressure and 24-hour urinary sodium were collected. The intervention includes government engagement, health education and other intervention components targeting restaurants, home cooks and primary school students and their families that have been used in other RCTs. The control group will not receive the intervention. The project will be followed up for 2 years, with the intervention being carried out for the first year only. The primary outcome is salt intake measured by 24-hour urinary sodium excretion after 1 year. The secondary outcomes are the long-lasting effectiveness on salt intake and blood pressure measured by the same method, as well as salt-related KAP and blood pressure at the 1-year and 2-year follow-ups. Process evaluation and health economics analysis will be conducted as well. ETHICS AND DISSEMINATION: The study was reviewed and approved by the Institutional Review Board of the National Center for Chronic and Noncommunicable Disease Control and Prevention, the Chinese Center for Disease Control and Prevention, and Queen Mary Research Ethics Committee. Results will be disseminated through presentations, publications and social media. TRIAL REGISTRATION NUMBER: ChiCTR1800018119

    Giant enhancement of spin accumulation and long-distance spin precession in metallic lateral spin valves

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    The nonlocal spin injection in lateral spin valves is highly expected to be an effective method to generate a pure spin current for potential spintronic application. However, the spin valve voltage, which decides the magnitude of the spin current flowing into an additional ferromagnetic wire, is typically of the order of 1 {\mu}V. Here we show that lateral spin valves with low resistive NiFe/MgO/Ag junctions enable the efficient spin injection with high applied current density, which leads to the spin valve voltage increased hundredfold. Hanle effect measurements demonstrate a long-distance collective 2-pi spin precession along a 6 {\mu}m long Ag wire. These results suggest a route to faster and manipulable spin transport for the development of pure spin current based memory, logic and sensing devices.Comment: 23 pages, 4 figure

    Pauli's Principle in Probe Microscopy

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    Exceptionally clear images of intramolecular structure can be attained in dynamic force microscopy through the combination of a passivated tip apex and operation in what has become known as the "Pauli exclusion regime" of the tip-sample interaction. We discuss, from an experimentalist's perspective, a number of aspects of the exclusion principle which underpin this ability to achieve submolecular resolution. Our particular focus is on the origins, history, and interpretation of Pauli's principle in the context of interatomic and intermolecular interactions.Comment: This is a chapter from "Imaging and Manipulation of Adsorbates using Dynamic Force Microscopy", a book which is part of the "Advances in Atom and Single Molecule Machines" series published by Springer [http://www.springer.com/series/10425]. To be published late 201
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