7,033 research outputs found

    Environmental factors and mortality risks associated influenza

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    BACKGROUND AND AIMS: The subtropical and tropical regions exhibit a distinct seasonality of influenza incidence from the temperate regions, and the mechanism behind it remains unclear. Environmental factors have been related to the transmission and survival of influenza viruses but no studies have ever explored the role of environmental factors on regulating severity of influenza infection. METHODS: We applied a Poisson regression model to the mortality data of two Asian metropolitan cities located at the subtropical zone, Guangzhou and Hong Kong. Interaction between …postprin

    Decreasing time consumption of microscopy image segmentation through parallel processing on the GPU

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    The computational performance of graphical processing units (GPUs) has improved significantly. Achieving speedup factors of more than 50x compared to single-threaded CPU execution are not uncommon due to parallel processing. This makes their use for high throughput microscopy image analysis very appealing. Unfortunately, GPU programming is not straightforward and requires a lot of programming skills and effort. Additionally, the attainable speedup factor is hard to predict, since it depends on the type of algorithm, input data and the way in which the algorithm is implemented. In this paper, we identify the characteristic algorithm and data-dependent properties that significantly relate to the achievable GPU speedup. We find that the overall GPU speedup depends on three major factors: (1) the coarse-grained parallelism of the algorithm, (2) the size of the data and (3) the computation/memory transfer ratio. This is illustrated on two types of well-known segmentation methods that are extensively used in microscopy image analysis: SLIC superpixels and high-level geometric active contours. In particular, we find that our used geometric active contour segmentation algorithm is very suitable for parallel processing, resulting in acceleration factors of 50x for 0.1 megapixel images and 100x for 10 megapixel images

    Disease burden of influenza in three tropic and sub-tropic cities in Asia

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    Powerpoint PresentationSession 2 - Disease burden and transmission dynamics of inter-pandemic influenzaThe impact of influenza on mortality in sub-tropical and tropical countries is poorly quantified. The obstacle is mainly from assessing the disease burden among irregular seasonality of influenza activities in the warm climates. In this study we applied statistical modeling methods to three metropolitan cities in East and Southeast Asia: Guangzhou, Hong Kong, and Singapore, all of which have standardized influenza surveillance networks for years 2004-2006. We applied the method of Generalized Additive Modeling (GAM) to evaluate the effect of influenza circulation in the community on all-cause mortality and on mortality with an underlying cause of cardio-respiratory diseases. The strength of GAM lies on its capability in adjusting for the seasonality of health outcomes in the investigation for their association with influenza activity, particularly in the subtropics and tropics. Our findings indicated that influenza was associated with 12.4 (95% confidence interval (CI): 1.2, 23.0), 13.9 (95% CI: 6.4, 20.9) and 8.7 (95% CI: 3.0, 13.9) deaths for all causes per 100,000 population in Guangzhou, Hong Kong, and Singapore, respectively. For the cardio-respiratory mortality, influenza was associated with 11.2 (95% CI: 2.4, 19.6), 9.1 (95% CI: 4.3, 13.6) and 5.5 (95% CI: 1.6, 9.4) deaths per 100,000 population in the three cites. These results showed that the disease burdens in the two subtropical cities Guangzhou and Hong Kong were similar and slightly higher than those in the tropical city, Singapore. In the future, a cross region study involving temperate, subtropical, and tropical climates could provide more information about the health effects of influenza in Asia.postprin

    A timely computer-aided detection system for acute ischemic and hemorrhagic stroke on CT in an emergency environment

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    Standalone Presentations: no. LL-IN1105BACKGROUND: When a patient is accepted in the emergency room suspected of stroke, time is of the most importance. The infarct brain area suffers irreparable damage as soon as three hours after the onset of stroke symptoms. Non-contrast CT scan is the standard first line of investigation used to identify hemorrhagic stroke cases. However, CT brain images do not show hyperacute ischemia and small hemorrhage clearly and thus may be missed by emergency physicians. We reported a timely computer-aided detection (CAD) system for small hemorrhages on CT that has been successfully developed as an aid to ER physicians to help improve detection for Acute Intracranial Hemorrhage (AIH). This CAD system has been enhanced for diagnosis of acute ischemic stroke in addition to hemorrhagic stroke, which becomes a more complete and clinically useful tool for assisting emergency physicians and radiologists. In the detection algorithm, brain matter is first segmented, realigned, and left-right brain symmetry is evaluated. As in the AIH system, the system confirms hemorrhagic stroke by detecting blood presence with anatomical and medical knowledge-based criteria. For detecting ischemia, signs such as regional hypodensity, blurring of grey and white matter differentiation, effacement of cerebral sulci, and hyperdensity in middle cerebral artery, are evaluated …published_or_final_versio

    Bipolar disorder prevalence and psychotropic medication utilisation in Hong Kong and the United Kingdom

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    PURPOSE: Bipolar disorder (BPD) is often an under-addressed mental disorder. Limited studies have investigated its epidemiology and drug utilisation in Hong Kong (HK) and the United Kingdom (UK) and thus local prescribing practices remain unclear. This study aimed to determine the prevalence of BPD and the prescribing of psychotropic medications as maintenance treatment from 2001-2018 in HK and the UK. METHOD: A retrospective study using the data from Clinical Data Analysis and Reporting System in HK and IQVIA Medical Research Data in the UK. RESULTS: The prevalence of BPD diagnosis in HK and the UK more than doubled during the study period. Some distinct changes in prescribing patterns over time were observed. Lithium use declined by 2.46% and 14.58% in HK and the UK, respectively. By 2018, patients were 4.6 times more likely to receive antidepressant monotherapy in the UK versus HK (15.62% vs. 3.42%). In HK, 38.41% of women of childbearing age were prescribed valproate in 2018 compared with 8.46% in the UK. CONCLUSION: The prevalence of BPD diagnosis has been increasing in HK and the UK. The disparity in prescribing patterns of BPD maintenance treatment in two regions reflected three major issues in clinical practice: (1) under-prescribing of lithium in both regions, (2) antidepressant monotherapy in the UK and (3) overprescribing of valproate to women of childbearing age in HK. A review of current clinical treatment guidelines and regulations of prescribing practice by local clinicians should be immediately implemented to ensure the safe use of medications in patients with BPD

    Impact of the COVID-19 pandemic on use of anti-dementia medications in 34 European and North American countries

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    INTRODUCTION: The impact of the COVID-19 pandemic on the global use of anti-dementia medication is unknown. We aimed to determine the changes of anti-dementia medication use in Europe (EU) and North America (NA) during the pandemic. METHODS: This is a cross-sectional study using sales data of anti-dementia medications in 2019 and 2020 from 34 EU and NA countries. The monthly uses of anti-dementia medications from January through June in 2020 were compared to the corresponding months in 2019 for each country. RESULTS: In the pre-pandemic period of January to March 2020, 70 out of 102 (3 months x 34 countries) measurements (68.6%) of monthly sales volume showed an increase. In contrast, 76.5% and 85.3% countries showed reduced sales in April and May 2020, respectively. DISCUSSION: These findings indicate changes in use of anti-dementia medications during the pandemic. The delivery of pharmaceutical care for dementia patients may be heavily disrupted in certain countries

    Structural Guided Scaffold Phage Display Libraries as a Source of Bio-Therapeutics

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    We have developed a structurally-guided scaffold phage display strategy for identification of ligand mimetic bio-therapeutics. As a proof of concept we used the ligand of integrin avb6, a tumour cell surface receptor and a major new target for imaging and therapy of many types of solid cancer. NMR structure analysis showed that RGD-helix structures are optimal for avb6 ligand-interaction, so we designed novel algorithms to generate human single chain fragment variable (scFv) libraries with synthetic VH-CDR3 encoding RGD-helix hairpins with helices of differing pitch, length and amino acid composition. Study of the lead scFv clones D25scFv and D34scFv and their corresponding VH-CDR3 derived peptides, D25p and D34p, demonstrated: specific binding to recombinant and cellular avb6; inhibition of avb6-dependent cell and ligand adhesion, avb6-dependent cell internalisation; and selective retention by avb6-expressing, but not avb6-negative, human xenografts. NMR analysis established that both the D25p and D34p retained RGD-helix structures confirming the success of the algorithm. In conclusion, scFv libraries can be engineered based on ligand structural motifs to increase the likelihood of developing powerful bio-therapeutics

    Combining Contrast Invariant L1 Data Fidelities with Nonlinear Spectral Image Decomposition

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    This paper focuses on multi-scale approaches for variational methods and corresponding gradient flows. Recently, for convex regularization functionals such as total variation, new theory and algorithms for nonlinear eigenvalue problems via nonlinear spectral decompositions have been developed. Those methods open new directions for advanced image filtering. However, for an effective use in image segmentation and shape decomposition, a clear interpretation of the spectral response regarding size and intensity scales is needed but lacking in current approaches. In this context, L1L^1 data fidelities are particularly helpful due to their interesting multi-scale properties such as contrast invariance. Hence, the novelty of this work is the combination of L1L^1-based multi-scale methods with nonlinear spectral decompositions. We compare L1L^1 with L2L^2 scale-space methods in view of spectral image representation and decomposition. We show that the contrast invariant multi-scale behavior of L1TVL^1-TV promotes sparsity in the spectral response providing more informative decompositions. We provide a numerical method and analyze synthetic and biomedical images at which decomposition leads to improved segmentation.Comment: 13 pages, 7 figures, conference SSVM 201

    Relationship between FEV1 change and patient-reported outcomes in randomised trials of inhaled bronchodilators for stable COPD: a systematic review.

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    BACKGROUND: Interactions between spirometry and patient-reported outcomes in COPD are not well understood. This systematic review and study-level analysis investigated the relationship between changes in FEV1 and changes in health status with bronchodilator therapy. METHODS: Six databases (to October 2009) were searched to identify studies with long-acting bronchodilator therapy reporting FEV1 and health status, dyspnoea or exacerbations. Mean and standard deviations of treatment effects were extracted for each arm of each study. Relationships between changes in trough FEV1 and outcomes were assessed using correlations and random-effects regression modelling. The primary outcome was St George's Respiratory Questionnaire (SGRQ) total score. RESULTS: Thirty-six studies (≥ 3 months) were included. Twenty-two studies (23,654 patients) with 49 treatment arms each contributing one data point provided SGRQ data. Change in trough FEV1 and change in SGRQ total score were negatively correlated (r = -0.46, p < 0.001); greater increases in FEV1 were associated with greater reductions (improvements) in SGRQ. The correlation strengthened with increasing study duration from 3 to 12 months. Regression modelling indicated that 100 mL increase in FEV1 (change at which patients are more likely to report improvement) was associated with a statistically significant reduction in SGRQ of 2.5 (95% CI 1.9, 3.1), while a clinically relevant SGRQ change (4.0) was associated with 160.6 (95% CI 129.0, 211.6) mL increase in FEV1. The association between change in FEV1 and other patient-reported outcomes was generally weak. CONCLUSIONS: Our analyses indicate, at a study level, that improvement in mean trough FEV1 is associated with proportional improvements in health status

    An Adaptive Approach for Processing Evoked Potentials From Human Auditory Cortex

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    Presents an adaptive approach for the processing of evoked potentials from the an auditory association cortex in humans. The approach can be conceptualized as a bank of least mean square adaptive signal enhancers. The recording data of each trial is then divided into several segments and each segment of data is input to corresponding adaptive signal enhancers. This approach allows the temporal variations of the evoked potential signal to be estimated across individual trials. This is a powerful tool for both clinical and research neurosciences. Two illustrative cases are shown.published_or_final_versio
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