1,449 research outputs found
Audio Source Separation Using Sparse Representations
This is the author's final version of the article, first published as A. Nesbit, M. G. Jafari, E. Vincent and M. D. Plumbley. Audio Source Separation Using Sparse Representations. In W. Wang (Ed), Machine Audition: Principles, Algorithms and Systems. Chapter 10, pp. 246-264. IGI Global, 2011. ISBN 978-1-61520-919-4. DOI: 10.4018/978-1-61520-919-4.ch010file: NesbitJafariVincentP11-audio.pdf:n\NesbitJafariVincentP11-audio.pdf:PDF owner: markp timestamp: 2011.02.04file: NesbitJafariVincentP11-audio.pdf:n\NesbitJafariVincentP11-audio.pdf:PDF owner: markp timestamp: 2011.02.04The authors address the problem of audio source separation, namely, the recovery of audio signals from recordings of mixtures of those signals. The sparse component analysis framework is a powerful method for achieving this. Sparse orthogonal transforms, in which only few transform coefficients differ significantly from zero, are developed; once the signal has been transformed, energy is apportioned from each transform coefficient to each estimated source, and, finally, the signal is reconstructed using the inverse transform. The overriding aim of this chapter is to demonstrate how this framework, as exemplified here by two different decomposition methods which adapt to the signal to represent it sparsely, can be used to solve different problems in different mixing scenarios. To address the instantaneous (neither delays nor echoes) and underdetermined (more sources than mixtures) mixing model, a lapped orthogonal transform is adapted to the signal by selecting a basis from a library of predetermined bases. This method is highly related to the windowing methods used in the MPEG audio coding framework. In considering the anechoic (delays but no echoes) and determined (equal number of sources and mixtures) mixing case, a greedy adaptive transform is used based on orthogonal basis functions that are learned from the observed data, instead of being selected from a predetermined library of bases. This is found to encode the signal characteristics, by introducing a feedback system between the bases and the observed data. Experiments on mixtures of speech and music signals demonstrate that these methods give good signal approximations and separation performance, and indicate promising directions for future research
Should hydroxyethyl starch solutions be totally banned?
The choice of which intravenous solution to prescribe remains a matter of considerable debate in intensive care units around the world. Trends have been moving away from using hydroxyethyl starch solutions following concerns about safety. But are the available data sufficient to clearly assess the risk-benefit balance for all patients, and is there enough evidence of harm to justify removing these drugs completely from our hospitals? © 2013 BioMed Central Ltd
Optimized intermolecular potential for nitriles based on Anisotropic United Atoms model
An extension of the Anisotropic United Atoms intermolecular potential model is proposed for nitriles. The electrostatic part of the intermolecular potential is calculated using atomic charges obtained by a simple Mulliken population analysis. The repulsion-dispersion interaction parameters for methyl and methylene groups are taken from transferable AUA4 literature parameters [Ungerer et al., J. Chem. Phys., 2000, 112, 5499]. Non-bonding Lennard-Jones intermolecular potential parameters are regressed for the carbon and nitrogen atoms of the nitrile group (–C≡N) from experimental vapor-liquid equilibrium data of acetonitrile. Gibbs Ensemble Monte Carlo simulations and experimental data agreement is very good for acetonitrile, and better than previous molecular potential proposed by Hloucha et al. [J. Chem. Phys., 2000, 113, 5401]. The transferability of the resulting potential is then successfully tested, without any further readjustment, to predict vapor-liquid phase equilibrium of propionitrile and n-butyronitrile
The epigenetic impacts of social stress: how does social adversity become biologically embedded?
Epigenetic mechanisms are implicated in the processes through which social stressors erode health in humans and other animals. Here I review progress in elucidating the biological pathways underlying the social gradient in health, with particular emphasis on how behavioral stresses influence epigenomic variation linked to health. The evidence that epigenetic changes are involved in embedding of social status-linked chronic stress is reviewed in the context of current knowledge about behavior within animal dominance hierarchies and the impacts of social position on behaviors that affect health. The roles of epigenetic mechanisms in responses to trauma and the evidence for their involvement in intergenerational transmission of the biological impacts of traumatic stress are also considered. Taken together, the emerging insights have important implications for development of strategies to improve societal health and well-being
Environmental Concern: Antecedents of Ecotourism Visit Intention with Time Perspective and Destination Image as Determination Variables
Environmental damage and sustainability become the center of attention along with climate change today. One of the interesting things is the change in behavior in the consumption of products categorized as "green", including in terms of choosing tourism destinations. Environmentally friendly tourism destinations or ecotourism is increasingly becoming an option for those who care about the environment. Ecotourism is also used by many countries, including travel agents, to increase their economic value or profit. This study aims to investigate how the role of Environmental Concern as antecendent of Ecoturism Visit Intention mediates the influence of Future Time perspective and Destination Image toward Ecotourism visit Intention.  This research involved 200 respondents who had visited ecotourism destinations at least twice, which was obtained using a convenience sample approach. The data were analyzed using Structural Equation Modelling (SEM) which were processed using the SmartPLS 4.0 statistical package. The result shows that Future Time perspective and Destination’s Image positively impact Ecotourism Intention.  Future Time perspective and Destination’s Image also influence Ecotourism Intention indirectly through Environmental Concern as the mediating variable. As an implication, the government and travel agents improve service readiness and perception of high-value propositions to develop a better destination image
Evolution and oncological outcomes of a contemporary radical prostatectomy practice in a UK regional tertiary referral centre
Objective
To investigate the clinical and pathological trends over a ten-year period for robotic-assisted laparoscopic prostatectomy (RALP) in a UK regional tertiary referral centre.
Patients and Methods
1500 consecutive patients underwent RALP between October 2005 and January 2015. Prospective data was collected on clinic-pathological details at presentation as well as surgical outcomes and compared over time.
Results
The median(range) age of patients throughout the period was 62(35-78) years. The proportion of pre-operative high-grade cases (Gleason sum 8-10) rose from 4.6% in 2005-2008 to 18.2% in 2013-2015 (p<0.0001). In the same periods the proportion of clinical stage T3 cases operated on rose from 2.4% to 11.4% (p<0.0001). Median PSA at diagnosis did not alter significantly. Overall 11.6% of men in 2005-2008 were classified pre-operatively as high-risk by NICE criteria, compared to 33.6% in 2013-2015 (p<0.0001). The corresponding proportions for low-risk cases were 48.6% and 17.3% respectively. Final surgical pathology demonstrated an increase in tumour stage, Gleason grade and nodal status across time. The proportion of pT3 cases rose from 43.2% in 2005-2008 to 55.5% in 2013-15 (p=0.0007), Gleason grade 9-10 tumours increased from 1.8% to 9.1% (p=0.0002) and positive nodal status increased from 1.6% to 12.9% (p<0.0001) between the same periods. Despite this, positive surgical margin rates showed a downward trend in all pT groups across the different eras (p=0.72).
Conclusion
This study suggests that the patient profile for RALP in our unit is changing, with increasing proportions of higher-stage and more advanced disease being referred and operated on. Surgical margin outcomes however have remained good.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/bju.1351
DeadEasy Mito-Glia: Automatic Counting of Mitotic Cells and Glial Cells in Drosophila
Cell number changes during normal development, and in disease (e.g., neurodegeneration, cancer). Many genes affect cell number, thus functional genetic analysis frequently requires analysis of cell number alterations upon loss of function mutations or in gain of function experiments. Drosophila is a most powerful model organism to investigate the function of genes involved in development or disease in vivo. Image processing and pattern recognition techniques can be used to extract information from microscopy images to quantify automatically distinct cellular features, but these methods are still not very extended in this model organism. Thus cellular quantification is often carried out manually, which is laborious, tedious, error prone or humanly unfeasible. Here, we present DeadEasy Mito-Glia, an image processing method to count automatically the number of mitotic cells labelled with anti-phospho-histone H3 and of glial cells labelled with anti-Repo in Drosophila embryos. This programme belongs to the DeadEasy suite of which we have previously developed versions to count apoptotic cells and neuronal nuclei. Having separate programmes is paramount for accuracy. DeadEasy Mito-Glia is very easy to use, fast, objective and very accurate when counting dividing cells and glial cells labelled with a nuclear marker. Although this method has been validated for Drosophila embryos, we provide an interactive window for biologists to easily extend its application to other nuclear markers and other sample types. DeadEasy MitoGlia is freely available as an ImageJ plug-in, it increases the repertoire of tools for in vivo genetic analysis, and it will be of interest to a broad community of developmental, cancer and neuro-biologists
How humans transmit language:horizontal transmission matches word frequencies among peers on Twitter
Environmental Concern: Antecedents of Ecotourism Visit Intention With Time Perspective and Destination Image as Determination Variables
Environmental damage and sustainability become the center of attention along with climate
change today. One of the interesting things is the change in behavior in the consumption of
products categorized as "green", including in terms of choosing tourism destinations. Environmentally
friendly tourism destinations or ecotourism is increasingly becoming an option
for those who care about the environment. Ecotourism is also used by many countries,
including travel agents, to increase their economic value or profit. This study aims to
investigate how the role of environmental concern as antecedent of ecoturism visit intention
mediates the influence of future time perspective and destination image toward ecotourism
visit intention. This research involved 200 respondents who had visited ecotourism
destinations at least twice, which was obtained using a convenience sample approach. The
data were analyzed using Structural Equation Modelling (SEM) which were processed using
the SmartPLS 4.0 statistical package. The result shows that future time perspective and destination’s image positively impact ecotourism intention. Future time perspective and
destination’s image also influence ecotourism intention indirectly through environmental concern as the mediating variable. As an implication, the government and travel agents improve service readiness and perception of high-value propositions to develop a better
destination image
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