232 research outputs found
Multiple source direction of arrival estimation using subspace pseudointensity vectors
The recently proposed subspace pseudointensity method for direction of
arrival estimation is applied in the context of Tasks 1 and 2 of the LOCATA
Challenge using the Eigenmike recordings. Specific implementation details are
described and results reported for the development dataset, for which the
ground truth source directions are available. For both single and multiple
source scenarios, the average absolute error angle is about 9 degrees.Comment: In Proceedings of the LOCATA Challenge Workshop - a satellite event
of IWAENC 2018 (arXiv:1811.08482
Subspace Hybrid MVDR Beamforming for Augmented Hearing
Signal-dependent beamformers are advantageous over signal-independent
beamformers when the acoustic scenario - be it real-world or simulated - is
straightforward in terms of the number of sound sources, the ambient sound
field and their dynamics. However, in the context of augmented reality audio
using head-worn microphone arrays, the acoustic scenarios encountered are often
far from straightforward. The design of robust, high-performance, adaptive
beamformers for such scenarios is an on-going challenge. This is due to the
violation of the typically required assumptions on the noise field caused by,
for example, rapid variations resulting from complex acoustic environments,
and/or rotations of the listener's head. This work proposes a multi-channel
speech enhancement algorithm which utilises the adaptability of
signal-dependent beamformers while still benefiting from the computational
efficiency and robust performance of signal-independent super-directive
beamformers. The algorithm has two stages. (i) The first stage is a hybrid
beamformer based on a dictionary of weights corresponding to a set of noise
field models. (ii) The second stage is a wide-band subspace post-filter to
remove any artifacts resulting from (i). The algorithm is evaluated using both
real-world recordings and simulations of a cocktail-party scenario. Noise
suppression, intelligibility and speech quality results show a significant
performance improvement by the proposed algorithm compared to the baseline
super-directive beamformer. A data-driven implementation of the noise field
dictionary is shown to provide more noise suppression, and similar speech
intelligibility and quality, compared to a parametric dictionary.Comment: 14 pages, 10 figures, submitted for IEEE/ACM Transactions on Audio,
Speech, and Language Processing on 23-Nov-202
Hyperbilirubinemia at hospitalization predicts nosocomial infection in decompensated cirrhosis:Data from ATTIRE trial
BACKGROUND: To identify clinical characteristics and serological biomarkers that predicted subsequent nosocomial infection in ATTIRE trial patients.METHODS: We identified 360 patients at hospitalization without infection and not prescribed antibiotics and compared clinical characteristics between those who subsequently developed a nosocomial infection and not. In a 68-patient subcohort, we compared plasma biomarkers of bacterial translocation, infection, and inflammation at hospitalization between those who developed a nosocomial infection and not. In a 56-patient subcohort, we investigated plasma lipidomic profiles in those who did and did not develop nosocomial infection using Lipotype Shotgun platform analysis and multivariate statistical techniques. To further investigate lipid pathways, we compared outcomes in patients taking statins or not at hospitalization.RESULTS: Serum bilirubin >188 µmol/L at hospitalization predicted subsequent nosocomial infection in univariate and multivariate analyses, with 80% specificity. The most common nosocomial infections were respiratory tract (29%) and those developing infection had significantly greater 28 and 90-day mortality than those not (p=9.34E-05 and 0.014). Serological biomarkers of bacterial translocation, infection, and inflammation did not predict subsequent infection. Partial least squares discriminatory analyses identified cholesterol esters (CEs) (CE.18.1.2, CE.18.1.0, and CE.16.0.0) as important predictors of infection but provided only a small improvement in predictive ability over bilirubin alone. RNA-sequencing analyses suggest this is mediated by a downregulation of the cellular cholesterol esterification enzyme sterol O-acyltransferase 1. Statin use was not associated with nosocomial infection prevention.CONCLUSIONS: In ATTIRE, elevated serum bilirubin at hospitalization was the only clinical characteristic that predicted subsequent development of nosocomial infection. Considering the rising incidence of antimicrobial resistance, these data could be used to limit antibiotic prophylaxis or aid trial design for investigating use in high-risk patients.</p
Therapeutic targeting of integrin αvβ6 in breast cancer
BACKGROUND: Integrin ?v?6 promotes migration, invasion, and survival of cancer cells; however, the relevance and role of ?v?6 has yet to be elucidated in breast cancer.METHODS: Protein expression of integrin subunit beta6 (?6) was measured in breast cancers by immunohistochemistry (n > 2000) and ITGB6 mRNA expression measured in the Molecular Taxonomy of Breast Cancer International Consortium dataset. Overall survival was assessed using Kaplan Meier curves, and bioinformatics statistical analyses were performed (Cox proportional hazards model, Wald test, and Chi-square test of association). Using antibody (264RAD) blockade and siRNA knockdown of ?6 in breast cell lines, the role of ?v?6 in Human Epidermal Growth Factor Receptor 2 (HER2) biology (expression, proliferation, invasion, growth in vivo) was assessed by flow cytometry, MTT, Transwell invasion, proximity ligation assay, and xenografts (n ? 3), respectively. A student's t-test was used for two variables; three-plus variables used one-way analysis of variance with Bonferroni's Multiple Comparison Test. Xenograft growth was analyzed using linear mixed model analysis, followed by Wald testing and survival, analyzed using the Log-Rank test. All statistical tests were two sided.RESULTS: High expression of either the mRNA or protein for the integrin subunit ?6 was associated with very poor survival (HR = 1.60, 95% CI = 1.19 to 2.15, P = .002) and increased metastases to distant sites. Co-expression of ?6 and HER2 was associated with worse prognosis (HR = 1.97, 95% CI = 1.16 to 3.35, P = .01). Monotherapy with 264RAD or trastuzumab slowed growth of MCF-7/HER2-18 and BT-474 xenografts similarly (P < .001), but combining 264RAD with trastuzumab effectively stopped tumor growth, even in trastuzumab-resistant MCF-7/HER2-18 xenografts.CONCLUSIONS: Targeting ?v?6 with 264RAD alone or in combination with trastuzumab may provide a novel therapy for treating high-risk and trastuzumab-resistant breast cancer patients.<br/
Ethnic and social inequalities in COVID-19 outcomes in Scotland:protocol for early pandemic evaluation and enhanced surveillance of COVID-19 (EAVE II)
Introduction: Evidence from previous pandemics, and the current COVID-19 pandemic, has found that risk of infection/severity of disease is disproportionately higher for ethnic minority groups, and those in lower socioeconomic positions. It is imperative that interventions to prevent the spread of COVID-19 are targeted towards high-risk populations. We will investigate the associations between social characteristics (such as ethnicity, occupation and socioeconomic position) and COVID-19 outcomes and the extent to which characteristics/risk factors might explain observed relationships in Scotland.
The primary objective of this study is to describe the epidemiology of COVID-19 by social factors. Secondary objectives are to (1) examine receipt of treatment and prevention of COVID-19 by social factors; (2) quantify ethnic/social differences in adverse COVID-19 outcomes; (3) explore potential mediators of relationships between social factors and SARS-CoV-2 infection/COVID-19 prognosis; (4) examine whether occupational COVID-19 differences differ by other social factors and (5) assess quality of ethnicity coding within National Health Service datasets.
Methods and analysis: We will use a national cohort comprising the adult population of Scotland who completed the 2011 Census and were living in Scotland on 31 March 2020 (~4.3 million people). Census data will be linked to the Early Assessment of Vaccine and Anti-Viral Effectiveness II cohort consisting of primary/secondary care, laboratory data and death records. Sensitivity/specificity and positive/negative predictive values will be used to assess coding quality of ethnicity. Descriptive statistics will be used to examine differences in treatment and prevention of COVID-19. Poisson/Cox regression analyses and mediation techniques will examine ethnic and social differences, and drivers of inequalities in COVID-19. Effect modification (on additive and multiplicative scales) between key variables (such as ethnicity and occupation) will be assessed.
Ethics and dissemination: Ethical approval was obtained from the National Research Ethics Committee, South East Scotland 02. We will present findings of this study at international conferences, in peer-reviewed journals and to policy-makers
Making it work for me: beliefs about making a personal health record relevant and useable.
BACKGROUND: A Personal Health Record (PHR) is an electronic record that individuals use to manage and share their health information, e.g. data from their medical records and data collected by apps. However, engagement with their record can be low if people do not find it beneficial to their health, wellbeing or interactions with health and other services. We have explored the beliefs potential users have about a PHR, how it could be made personally relevant, and barriers to its use. METHODS: A qualitative design comprising eight focus groups, each with 6-8 participants. Groups included adults with long-term health conditions, young people, physically active adults, data experts, and members of the voluntary sector. Each group lasted 60-90 min, was audio recorded and transcribed verbatim. We analysed the data using thematic analysis to address the question "What are people's beliefs about making a Personal Health Record have relevance and impact?" RESULTS: We found four themes. Making it work for me is about how to encourage individuals to actively engage with their PHR. I control my information is about individuals deciding what to share and who to share it with. My concerns is about individuals' concerns about information security and if and how their information will be acted upon. Potential impact shows the potential benefits of a PHR such as increasing self-efficacy, uptake of health-protective behaviours, and professionals taking a more holistic approach to providing care and facilitating behaviour change. CONCLUSIONS: Our research shows the functionality that a PHR requires in order for people to engage with it. Interactive functions and integration with lifestyle and health apps are particularly important. A PHR could increase the effectiveness of behaviour change apps by specifying evidence-based behaviour change techniques that apps should incorporate. A PHR has the potential to increase health-protective behaviours and facilitate a more person-driven health and social care system. It could support patients to take responsibility for self-managing their health and treatment regimens, as well as helping patients to play a more active role when care transfers across boundaries of responsibility
Successful awake proning is associated with improved clinical outcomes in patients with COVID-19: single-centre high-dependency unit experience
The SARS-CoV-2 can lead to severe illness with COVID-19. Outcomes of patients requiring mechanical ventilation are poor. Awake proning in COVID-19 improves oxygenation, but on data clinical outcomes is limited. This single-centre retrospective study aimed to assess whether successful awake proning of patients with COVID-19, requiring respiratory support (continuous positive airways pressure (CPAP) or high-flow nasal oxygen (HFNO)) on a respiratory high-dependency unit (HDU), is associated with improved outcomes. HDU care included awake proning by respiratory physiotherapists. Of 565 patients admitted with COVID-19, 71 (12.6%) were managed on the respiratory HDU, with 48 of these (67.6%) requiring respiratory support. Patients managed with CPAP alone 22/48 (45.8%) were significantly less likely to die than patients who required transfer onto HFNO 26/48 (54.2%): CPAP mortality 36.4%; HFNO mortality 69.2%, (p=0.023); however, multivariate analysis demonstrated that increasing age and the inability to awake prone were the only independent predictors of COVID-19 mortality. The mortality of patients with COVID-19 requiring respiratory support is considerable. Data from our cohort managed on HDU show that CPAP and awake proning are possible in a selected population of COVID-19, and may be useful. Further prospective studies are required
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AI-based automation of enrollment criteria and endpoint assessment in clinical trials in liver diseases
Clinical trials in metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis) require histologic scoring for assessment of inclusion criteria and endpoints. However, variability in interpretation has impacted clinical trial outcomes. We developed an artificial intelligence-based measurement (AIM) tool for scoring MASH histology (AIM-MASH). AIM-MASH predictions for MASH Clinical Research Network necroinflammation grades and fibrosis stages were reproducible (κ = 1) and aligned with expert pathologist consensus scores (κ = 0.62-0.74). The AIM-MASH versus consensus agreements were comparable to average pathologists for MASH Clinical Research Network scores (82% versus 81%) and fibrosis (97% versus 96%). Continuous scores produced by AIM-MASH for key histological features of MASH correlated with mean pathologist scores and noninvasive biomarkers and strongly predicted progression-free survival in patients with stage 3 (P < 0.0001) and stage 4 (P = 0.03) fibrosis. In a retrospective analysis of the ATLAS trial (NCT03449446), responders receiving study treatment showed a greater continuous change in fibrosis compared with placebo (P = 0.02). Overall, these results suggest that AIM-MASH may assist pathologists in histologic review of MASH clinical trials, reducing inter-rater variability on trial outcomes and offering a more sensitive and reproducible measure of patient responses
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