4,433 research outputs found
Efficient Bayesian inference for harmonic models via adaptive posterior factorization
NOTICE: this is the author’s version of a work that was accepted for publication in Neurocomputing. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in NEUROCOMPUTING, [VOL72, ISSUE 1-3, (2008)] DOI10.1016/j.neucom.2007.12.05
Sound Source Separation
This is the author's accepted pre-print of the article, first published as G. Evangelista, S. Marchand, M. D. Plumbley and E. Vincent. Sound source separation. In U. Zölzer (ed.), DAFX: Digital Audio Effects, 2nd edition, Chapter 14, pp. 551-588. John Wiley & Sons, March 2011. ISBN 9781119991298. DOI: 10.1002/9781119991298.ch14file: Proof:e\EvangelistaMarchandPlumbleyV11-sound.pdf:PDF owner: markp timestamp: 2011.04.26file: Proof:e\EvangelistaMarchandPlumbleyV11-sound.pdf:PDF owner: markp timestamp: 2011.04.2
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
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Chondrocyte outgrowth into a gelatin scaffold in a single impact load model of damage/repair - effect of BMP-2.
BACKGROUND: Articular cartilage has little capacity for repair in vivo, however, a small number of studies have shown that, in vitro, a damage/repair response can be induced. Recent work by our group has shown that cartilage can respond to single impact load and culture by producing repair cells on the articular surface. The purpose of this study was to identify whether chondrocyte outgrowth into a 3D scaffold could be observed following single impact load and culture. The effect of bone morphogenic-2 (BMP-2) on this process was investigated. METHODS: Cartilage explants were single impact loaded, placed within a scaffold and cultured for up to 20 days +/- BMP-2. Cell numbers in the scaffold, on and extruding from the articular surface were quantified and the immunohistochemistry used to identify the cellular phenotype. RESULTS: Following single impact load and culture, chondrocytes were observed in a 3D gelatin scaffold under all culture conditions. Chondrocytes were also observed on the articular surface of the cartilage and extruding out of the parent cartilage and on to the cartilage surface. BMP-2 was demonstrated to quantitatively inhibit these events. CONCLUSION: These studies demonstrate that articular chondrocytes can be stimulated to migrate out of parent cartilage following single impact load and culture. The addition of BMP-2 to the culture medium quantitatively reduced the repair response. It may be that the inhibitory effect of BMP-2 in this experimental model provides a clue to the apparent inability of articular cartilage to heal itself following damage in vivo.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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Alterations in the vimentin cytoskeleton in response to single impact load in an in vitro model of cartilage damage in the rat.
BACKGROUND: Animal models have provided much information on molecular and cellular changes in joint disease, particularly OA. However there are limitations to in vivo work and single tissue in vitro studies can provide more specific information on individual events. The rat is a commonly used laboratory species but at the current time only in vivo models of rat OA are available to study. The purpose of this study was to investigate the damage that single impact load (SIL) of 0.16J causes in a rat cartilage in vitro model and assess whether this load alters the arrangement of vimentin. METHODS: Rat cartilage was single impact loaded (200 g from 8 cm) and cultured for up to 48 hours (n = 72 joints). Histological changes were measured using a semi-quantitative modified Mankin score. Immunolocalisation was used to identify changes in vimentin distribution. RESULTS: SIL caused damage in 32/36 cartilage samples. Damage included surface fibrillation, fissures, fragmentation, changes in cellularity and loss of proteoglycan. SIL caused a statistically significant increase in modified Mankin score and chondrocyte clusters over time. SIL caused vimentin disassembly (as evidenced by collapse of vimentin around the nucleus). CONCLUSION: This study describes a model of SIL damage to rat cartilage. SIL causes changes in histological/chemical parameters which have been measured using a semi-quantitative modified Mankin score. Single impact load also causes changes in the pattern of vimentin immunoreactivity, indicating vimentin dissassembley. Using a semi-quantitative scoring system the disassembly was shown to be statistically significant in SIL damaged cartilage. The changes described in this paper suggest that this novel single tissue rat model of joint damage is a possible candidate model to replace in vivo models.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
VConv-DAE: Deep Volumetric Shape Learning Without Object Labels
With the advent of affordable depth sensors, 3D capture becomes more and more
ubiquitous and already has made its way into commercial products. Yet,
capturing the geometry or complete shapes of everyday objects using scanning
devices (e.g. Kinect) still comes with several challenges that result in noise
or even incomplete shapes. Recent success in deep learning has shown how to
learn complex shape distributions in a data-driven way from large scale 3D CAD
Model collections and to utilize them for 3D processing on volumetric
representations and thereby circumventing problems of topology and
tessellation. Prior work has shown encouraging results on problems ranging from
shape completion to recognition. We provide an analysis of such approaches and
discover that training as well as the resulting representation are strongly and
unnecessarily tied to the notion of object labels. Thus, we propose a full
convolutional volumetric auto encoder that learns volumetric representation
from noisy data by estimating the voxel occupancy grids. The proposed method
outperforms prior work on challenging tasks like denoising and shape
completion. We also show that the obtained deep embedding gives competitive
performance when used for classification and promising results for shape
interpolation
B-Cell Non-Hodgkin’s Lymphoma: viewing an aggressive neck mass in an older adult from a primary care perspective
Abstract
Patients with neck masses typically present to primary care providers, but most are unfamiliar with the management of aggressively expanding neck masses. With so many varied structures in the cervical region, a rapidly growing neck mass can be a diagnostic dilemma. The broad initial differential includes infectious, inflammatory, vascular, and malignant causes. When the clinical course points to an aggressive malignancy, the location of the mass helps provide the clues to the likely etiology. Potential sites of involvement include the musculature, bone, larynx, trachea, esophagus, lymph tissue and thyroid tissue. Anterior neck masses at the level the thyroid should prompt a differential of primary thyroid lymphomas. Diffuse large B-cell lymphoma is most common, followed by mucosa-associated lymphoid tissue lymphoma, follicular lymphoma, and small lymphocytic lymphoma. Anaplastic thyroid carcinoma should be considered as well. A history of Hashimoto’s thyroiditis should lead the clinician toward the large B-cell lymphoma.Prompt diagnosis via fine-needle aspiration biopsy is essential, because compressive symptoms and airway collapse may rapidly ensue. A correct clinical and histopathologic diagnosis is essential. Primary thyroid lymphoma can often be treated with chemoimmunotherapy and radiation has a mean overall survival of 9.0 years. Anaplastic thyroid carcinoma is often locally aggressive with advanced metastatic disease at presentation, and treatment options are more limited. Primary care physicians need to be familiar with these relatively rare etiologies for an aggressively expanding neck mass in order to recognize and rapidly coordinate diagnostic and treatment options in a timely fashion
Opioid Consumption after Orthopedic Surgery: Prospective Randomized Trial on the Effects of Preoperative Counseling
Introduction: Recently, there have been increases in morbidity and mortality associated with opioid medications. Physician overprescribing, particularly within orthopedics, contributes to large quantities of leftover opioids, leading to an increased risk of non-medical opioid use and abuse.
Objective: To understand the role of preoperative patient counseling on postoperative opioid consumption, a prospective randomized study was done, with the idea that patients receiving counseling would take fewer opioids than their control counterparts.
Methods: Patients undergoing elective outpatient orthopedic surgery at Jefferson affiliate hospitals were enrolled over a 3-month period. Patients were randomized to a control group or to receive preoperative counseling in the form of a multimedia presentation aimed at educating the patient on opioid medications, strategies for pain management and the opioid epidemic. Information on demographics, surgical procedure, amount and type of opioid prescribed, number of opioids consumed and non-opioid analgesic use was collected at the first postoperative visit.
Results: 283 patients were enrolled (57% women, 43% men). On average, patients who were counseled consumed 2.30 fewer opioids than their control counterparts (P=0.0497), equating to 34% of their entire prescription, compared to 42% in the control. Among patients who were counseled, 84.16% thought the preoperative multimedia presentation was helpful and 92.86% thought that all patients should watch the video before surgery.
Discussion: There is evidence to suggest that preoperative opioid counseling is effective in decreasing postoperative opioid consumption. Leftover opioids totaled nearly 4,000 among all patients, indicating that orthopedic surgeons are prescribing far more than are being consumed
Alcohol and the heart: to abstain or not to abstain?
Alcohol has been consumed by most societies over the last 7000 years. Abraham Lincoln said It has long been recognized that the problems with alcohol relate not to the use of a bad thing, but to the abuse of a good thing. Light to moderate alcohol consumption reduces the incidence of coronary heart disease (CHD), ischemic stroke, peripheral arterial disease, CHD mortality, and all-cause mortality, especially in the western populations. However, heavy alcohol consumption is detrimental causing cardiomyopathy, cardiac arrhythmias, hepatic cirrhosis, pancreatitis, and hemorrhagic stroke. In this article, we review the effects of alcohol on CHD, individual cardiovascular risk factors, cardiomyopathy, and cardiac arrhythmias, including the most recent evidence of the effects of alcohol on CHD
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