2,336 research outputs found

    Improved speech presence probability estimation based on wavelet denoising

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    A reliable estimator for speech presence probability (SPP) can significantly improve the performance of many speech enhancement algorithms. Previous work showed that a good SPP estimator can be obtained by using a smooth a-posteriori signal to noise ratio (SNR) function, which can be achieved by reducing the noise variance when estimating the speech power spectrum. In this paper, a wavelet based denoising algorithm is proposed for such purpose. We first apply the wavelet transform to the periodogram of a noisy speech signal to generate an oracle for indicating the locations of the noise floor in the periodogram. We then make use of that oracle to selectively remove the wavelet coefficients of the noise floor in the log multitaper spectrum (MTS) of the noisy speech. The remaining wavelet coefficients are then used to reconstruct a denoised MTS and in turn generate a smooth a-posteriori SNR function. Simulation results show that the new SPP estimator outperforms the traditional approaches and enables a significantly improvement in the quality and intelligibility of the enhanced speeches. © 2012 IEEE.published_or_final_versio

    An assessment of tumour and nodal bulk volume for Chinese patients with non small cell lung cancer

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    Session - Respiratory & Critical Care Medicine: no. G-RC-14published_or_final_versio

    A fully automated home cage for long-term continuous phenotyping of mouse cognition and behavior

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    Automated home-cage monitoring systems present a valuable tool for comprehensive phenotyping of natural behaviors. However, current systems often involve complex training routines, water or food restriction, and probe a limited range of behaviors. Here, we present a fully automated home-cage monitoring system for cognitive and behavioral phenotyping in mice. The system incorporates T-maze alternation, novel object recognition, and object-in-place recognition tests combined with monitoring of locomotion, drinking, and quiescence patterns, all carried out over long periods. Mice learn the tasks rapidly without any need for water or food restrictions. Behavioral characterization employs a deep convolutional neural network image analysis. We show that combined statistical properties of multiple behaviors can be used to discriminate between mice with hippocampal, medial entorhinal, and sham lesions and predict the genotype of an Alzheimer's disease mouse model with high accuracy. This technology may enable large-scale behavioral screening for genes and neural circuits underlying spatial memory and other cognitive processes

    Is exercise protective against influenza-associated mortality?

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    Background: Little is known about the effect of physical exercise on influenza-associated mortality. Methods and Findings: We collected information about exercise habits and other lifestyle, and socioeconomic and demographic status, the underlying cause of death of 24,656 adults (21% aged 30-64, 79% aged 65 or above who died in 1998 in Hong Kong, and the weekly proportion of specimens positive for influenza A (H3N1 and H1N1) and B isolation during the same period. We assessed the excess risks (ER) of influenza-associated mortality due to all-natural causes, cardiovascular diseases, or respiratory disease among different levels of exercise: never/seldom (less than once per month), low/moderate (once per month to three times per week), and frequent (four times or more per week) by Poisson regression. We also assessed the differences in ER between exercise groups by case-only logistic regression. For all the mortality outcomes under study in relation to each 10% increase in weekly proportion of specimens positive for influenza A+B, never/seldom exercise (as reference) was associated with 5.8% to 8.5% excess risks (ER) of mortality (P<0.0001), while low/moderate exercise was associated with ER which were 4.2% to 6.4% lower than those of the reference (P<0.001 for all-natural causes; P=0.001 for cardiovascular; and P=0.07 for respiratory mortality). Frequent exercise was not different from the reference (change in ER -0.8% to 1.7%, P=0.30 to 0.73). Conclusion: When compared with never or seldom exercise, exercising at low to moderate frequency is beneficial with lower influenza-associated mortality. © 2008 Wong et al.published_or_final_versio

    Optimising antimicrobial prescription in hospitals by introducing an antimicrobial stewardship programme in Hong Kong: Consensus statement

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    Objective. To discuss the implementation of an 'antimicrobial stewardship programme' as a means to improve the quality of antimicrobial use in a hospital setting in Hong Kong. Participants. Consensus working group on 'antimicrobial stewardship programme', The Scientific Committee on Infection Control, Centre for Health Protection, Department of Health, comprised 11 experts. The remit of the working group was to discuss the rationale and requirement for optimising antimicrobial prescriptions in hospitals by the introduction of an 'antimicrobial stewardship programme'. Evidence. PubMed articles, national and international guidelines, and abstracts of international meetings published between January 2000 and December 2004 on programmes for improving the use of antimicrobials in hospitals. Only English medical literature was reviewed. Consensus process. Data search was performed independently by three members of the working group. They met on three occasions before the meeting to discuss all collected articles. A final draft was circulated to the working group before a meeting on 3 January 2005. Five commonly asked questions about an 'antimicrobial stewardship programme' were selected for discussion by the participants. Published information on the rationale, components, outcome measures, advantages, and disadvantages of the programme was reviewed. Recent unpublished data from local studies of an 'antimicrobial stewardship programme' were also discussed. The timing, potential problems, and practical issues involved in the implementation of an 'antimicrobial stewardship programme' in Hong Kong were then considered. The consensus statement was circulated to and approved by all participants. Conclusion. The continuous indiscriminate and excessive use of antimicrobial agents promotes the emergence of antibiotic-resistant organisms. Antimicrobial resistance substantially raises already-rising health care costs and increases patient morbidity and mortality. Pattern of prescriptions in hospitals can be improved through the implementation of an 'antimicrobial stewardship programme'. A 'universal' and 'continuous' 'antimicrobial stewardship programme' should now be established in Hong Kong hospitals.published_or_final_versio

    Acid-sensing ion channel 3 mediates peripheral anti-hyperalgesia effects of acupuncture in mice inflammatory pain

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    <p>Abstract</p> <p>Background</p> <p>Peripheral tissue inflammation initiates hyperalgesia accompanied by tissue acidosis, nociceptor activation, and inflammation mediators. Recent studies have suggested a significantly increased expression of acid-sensing ion channel 3 (ASIC3) in both carrageenan- and complete Freund's adjuvant (CFA)-induced inflammation. This study tested the hypothesis that acupuncture is curative for mechanical hyperalgesia induced by peripheral inflammation.</p> <p>Methods</p> <p>Here we used mechanical stimuli to assess behavioral responses in paw and muscle inflammation induced by carrageenan or CFA. We also used immunohistochemistry staining and western blot methodology to evaluate the expression of ASIC3 in dorsal root ganglion (DRG) neurons.</p> <p>Results</p> <p>In comparison with the control, the inflammation group showed significant mechanical hyperalgesia with both intraplantar carrageenan and CFA-induced inflammation. Interestingly, both carrageenan- and CFA-induced hyperalgesia were accompanied by ASIC3 up-regulation in DRG neurons. Furthermore, electroacupuncture (EA) at the ST36 rescued mechanical hyperalgesia through down-regulation of ASIC3 overexpression in both carrageenan- and CFA-induced inflammation.</p> <p>Conclusions</p> <p>In addition, electrical stimulation at the ST36 acupoint can relieve mechanical hyperalgesia by attenuating ASIC3 overexpression.</p

    Performance of the new automated Abbott RealTime MTB assay for rapid detection of Mycobacterium tuberculosis complex in respiratory specimens

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    The automated high-throughput Abbott RealTime MTB real-time PCR assay has been recently launched for Mycobacterium tuberculosis complex (MTBC) clinical diagnosis. This study would like to evaluate its performance. We first compared its diagnostic performance with the Roche Cobas TaqMan MTB assay on 214 clinical respiratory specimens. Prospective analysis of a total 520 specimens was then performed to further evaluate the Abbott assay. The Abbott assay showed a lower limit of detection at 22.5 AFB/ml, which was more sensitive than the Cobas assay (167.5 AFB/ml). The two assays demonstrated a significant difference in diagnostic performance (McNemar’s test; P = 0.0034), in which the Abbott assay presented significantly higher area under curve (AUC) than the Cobas assay (1.000 vs 0.880; P = 0.0002). The Abbott assay demonstrated extremely low PCR inhibition on clinical respiratory specimens. The automated Abbott assay required only very short manual handling time (0.5 h), which could help to improve the laboratory management. In the prospective analysis, the overall estimates for sensitivity and specificity of the Abbott assay were both 100 % among smear-positive specimens, whereas the smear-negative specimens were 96.7 and 96.1 %, respectively. No cross-reactivity with non-tuberculosis mycobacterial species was observed. The superiority in sensitivity of the Abbott assay for detecting MTBC in smear-negative specimens could further minimize the risk in MTBC false-negative detection. The new Abbott RealTime MTB assay has good diagnostic performance which can be a useful diagnostic tool for rapid MTBC detection in clinical laboratories. © 2015, Springer-Verlag Berlin Heidelberg.postprin
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