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https://www.readbyqxmd.com/read/28230712/updating-evidence-for-using-hypothermia-in-pediatric-severe-traumatic-brain-injury-conventional-and-bayesian-meta-analytic-perspectives
#1
Robert C Tasker, Frederick W Vonberg, Elizabeth D Ulano, Alireza Akhondi-Asl
OBJECTIVE: To evaluate clinical trials of hypothermia management on outcome in pediatric patients with severe traumatic brain injury using conventional and Bayesian meta-analyses. DATA SOURCES: Screening of PubMed and other databases to identify randomized controlled trials of hypothermia for pediatric severe traumatic brain injury published before September 2016. STUDY SELECTION: Four investigators assessed and reviewed randomized controlled trial data...
February 20, 2017: Pediatric Critical Care Medicine
https://www.readbyqxmd.com/read/28230525/inference-and-forecast-of-h7n9-influenza-in-china-2013-to-2015
#2
Ruiyun Li, Yuqi Bai, Alex Heaney, Sasikiran Kandula, Jun Cai, Xuyi Zhao, Bing Xu, Jeffrey Shaman
The recent emergence of A(H7N9) avian influenza poses a significant challenge to public health in China and around the world; however, understanding of the transmission dynamics and progression of influenza A(H7N9) infection in domestic poultry, as well as spillover transmission to humans, remains limited. Here, we develop a mathematical model-Bayesian inference system which combines a simple epidemic model and data assimilation method, and use it in conjunction with data on observed human influenza A(H7N9) cases from 19 February 2013 to 19 September 2015 to estimate key epidemiological parameters and to forecast infection in both poultry and humans...
February 16, 2017: Euro Surveillance: Bulletin Européen sur les Maladies Transmissibles, European Communicable Disease Bulletin
https://www.readbyqxmd.com/read/28228750/evolutionary-roots-and-diversification-of-the-genus-aeromonas
#3
Ariadna Sanglas, Vicenta Albarral, Maribel Farfán, J G Lorén, M C Fusté
Despite the importance of diversification rates in the study of prokaryote evolution, they have not been quantitatively assessed for the majority of microorganism taxa. The investigation of evolutionary patterns in prokaryotes constitutes a challenge due to a very scarce fossil record, limited morphological differentiation and frequently complex taxonomic relationships, which make even species recognition difficult. Although the speciation models and speciation rates in eukaryotes have traditionally been established by analyzing the fossil record data, this is frequently incomplete, and not always available...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28228504/the-dynamics-of-gastric-emptying-and-self-reported-feelings-of-satiation-are-better-predictors-than-gastrointestinal-hormones-of-the-effects-of-lipid-emulsion-structure-on-fat-digestion-in-healthy-adults-a-bayesian-inference-approach
#4
Andreas Steingoetter, Simon Buetikofer, Jelena Curcic, Dieter Menne, Jens F Rehfeld, Michael Fried, Werner Schwizer, Tim J Wooster
Background: Limited information exists on the relation between fat emulsion structure and its effect on the release of gastrointestinal hormones and feelings of satiation.Objective: We investigated the impact of fat emulsion droplet size, gravitational and acid stability, and redispersibility on gastrointestinal responses and sought to deduce the relative importance of the hormones ghrelin, cholecystokinin, glucagon-like peptide-1, and peptide YY (PYY) in controlling fat emptying and related satiation.Methods: Within a randomized, double-blind, 4-armed crossover study, an extensive data set was generated by MRI of gastric function, analysis of hormone profiles, and ratings of satiation in healthy participants [10 women and 7 men with a mean ± SD age of 25 ± 7 y and body mass index (in kg/m(2)) of 22 ± 1] after intake of 4 different fat emulsions...
February 22, 2017: Journal of Nutrition
https://www.readbyqxmd.com/read/28227709/bayesian-gaussian-processes-for-identifying-the-deteriorating-patient
#5
Glen Wright Colopy, Marco A F Pimentel, Stephen J Roberts, David A Clifton, Glen Wright Colopy, Marco A F Pimentel, Stephen J Roberts, David A Clifton, Glen Wright Colopy, Marco A F Pimentel, Stephen J Roberts, David A Clifton
The step-down unit (SDU) is a high-acuity hospital environment, to which patients may be sent after discharge from the intensive care unit (ICU). About 1- in-7 patients will deteriorate in the SDU and require emergency readmission to the ICU. Upon readmission, these patients experience significantly higher mortality risks and lengths of stay. Gaussian process regression (GPR) models are proposed as a flexible, principled, probabilistic method to address the clinical need to monitor continuously patient time-series of vital signs acquired in the SDU...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226784/parameter-estimation-for-gene-regulatory-networks-a-two-stage-mcmc-bayesian-approach
#6
Niannan Xue, Wei Pan, Yike Guo, Niannan Xue, Wei Pan, Yike Guo, Wei Pan, Yike Guo, Niannan Xue
Genetic regulatory networks have emerged as a useful way to elucidate the biochemical pathways for biological functions. Yet, determination of the exact parametric forms for these models remain a major challenge. In this paper, we present a novel computational approach implemented in C++ to solve this inverse problem. This takes the form of an optimization stage first after which Bayesian filtering takes place. The key advantage of such a flexible, general and robust approach is that it provides us with a joint probability distribution of the model parameters instead of single estimates, which we can propagate to final predictions...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226543/development-of-a-novel-probabilistic-algorithm-for-localization-of-rotors-during-atrial-fibrillation
#7
Prasanth Ganesan, Anthony Salmin, Elizabeth M Cherry, Behnaz Ghoraani, Prasanth Ganesan, Anthony Salmin, Elizabeth M Cherry, Behnaz Ghoraani, Elizabeth M Cherry, Prasanth Ganesan, Behnaz Ghoraani, Anthony Salmin
Atrial fibrillation (AF) is an irregular heart rhythm that can lead to stroke and other heart-related complications. Catheter ablation has been commonly used to destroy triggering sources of AF in the atria and consequently terminate the arrhythmia. However, efficient and accurate localization of the AF sustaining sources known as rotors is a major challenge in catheter ablation. In this paper, we developed a novel probabilistic algorithm that can adaptively guide a Lasso diagnostic catheter to locate the center of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226531/bayesian-deconvolution-of-scanning-electron-microscopy-images-using-point-spread-function-estimation-and-non-local-regularization
#8
Joris Roels, Jan Aelterman, Jonas De Vylder, Hiep Luong, Yvan Saeys, Wilfried Philips, Joris Roels, Jan Aelterman, Jonas De Vylder, Hiep Luong, Yvan Saeys, Wilfried Philips, Hiep Luong, Wilfried Philips, Jan Aelterman, Jonas De Vylder, Yvan Saeys, Joris Roels
Microscopy is one of the most essential imaging techniques in life sciences. High-quality images are required in order to solve (potentially life-saving) biomedical research problems. Many microscopy techniques do not achieve sufficient resolution for these purposes, being limited by physical diffraction and hardware deficiencies. Electron microscopy addresses optical diffraction by measuring emitted or transmitted electrons instead of photons, yielding nanometer resolution. Despite pushing back the diffraction limit, blur should still be taken into account because of practical hardware imperfections and remaining electron diffraction...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226392/bayesian-semiparametric-variable-selection-with-applications-to-periodontal-data
#9
Bo Cai, Dipankar Bandyopadhyay
A normality assumption is typically adopted for the random effects in a clustered or longitudinal data analysis using a linear mixed model. However, such an assumption is not always realistic, and it may lead to potential biases of the estimates, especially when variable selection is taken into account. Furthermore, flexibility of nonparametric assumptions (e.g., Dirichlet process) on these random effects may potentially cause centering problems, leading to difficulty of interpretation of fixed effects and variable selection...
February 22, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28226298/the-effect-of-muscle-fatigue-and-low-back-pain-on-lumbar-movement-variability-and-complexity
#10
C M Bauer, F M Rast, M J Ernst, A Meichtry, J Kool, S M Rissanen, J H Suni, M Kankaanpää
INTRODUCTION: Changes in movement variability and complexity may reflect an adaptation strategy to fatigue. One unresolved question is whether this adaptation is hampered by the presence of low back pain (LBP). This study investigated if changes in movement variability and complexity after fatigue are influenced by the presence of LBP. It is hypothesised that pain free people and people suffering from LBP differ in their response to fatigue. METHODS: The effect of an isometric endurance test on lumbar movement was tested in 27 pain free participants and 59 participants suffering from LBP...
February 13, 2017: Journal of Electromyography and Kinesiology
https://www.readbyqxmd.com/read/28225816/bayesian-prediction-of-placebo-analgesia-in-an-instrumental-learning-model
#11
Won-Mo Jung, Ye-Seul Lee, Christian Wallraven, Younbyoung Chae
Placebo analgesia can be primarily explained by the Pavlovian conditioning paradigm in which a passively applied cue becomes associated with less pain. In contrast, instrumental conditioning employs an active paradigm that might be more similar to clinical settings. In the present study, an instrumental conditioning paradigm involving a modified trust game in a simulated clinical situation was used to induce placebo analgesia. Additionally, Bayesian modeling was applied to predict the placebo responses of individuals based on their choices...
2017: PloS One
https://www.readbyqxmd.com/read/28224498/differential-gene-expression-dex-and-alternative-splicing-events-ase-for-temporal-dynamic-processes-using-hmms-and-hierarchical-bayesian-modeling-approaches
#12
Sunghee Oh, Seongho Song
In gene expression profile, data analysis pipeline is categorized into four levels, major downstream tasks, i.e., (1) identification of differential expression; (2) clustering co-expression patterns; (3) classification of subtypes of samples; and (4) detection of genetic regulatory networks, are performed posterior to preprocessing procedure such as normalization techniques. To be more specific, temporal dynamic gene expression data has its inherent feature, namely, two neighboring time points (previous and current state) are highly correlated with each other, compared to static expression data which samples are assumed as independent individuals...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28224368/generalized-fiducial-inference-for-logistic-graded-response-models
#13
Yang Liu, Jan Hannig
Samejima's graded response model (GRM) has gained popularity in the analyses of ordinal response data in psychological, educational, and health-related assessment. Obtaining high-quality point and interval estimates for GRM parameters attracts a great deal of attention in the literature. In the current work, we derive generalized fiducial inference (GFI) for a family of multidimensional graded response model, implement a Gibbs sampler to perform fiducial estimation, and compare its finite-sample performance with several commonly used likelihood-based and Bayesian approaches via three simulation studies...
February 21, 2017: Psychometrika
https://www.readbyqxmd.com/read/28222743/estimating-deaths-attributable-to-airborne-particles-sensitivity-of-the-results-to-different-exposure-assessment-approaches
#14
Simone Giannini, Michela Baccini, Giorgia Randi, Giovanni Bonafè, Paolo Lauriola, Andrea Ranzi
BACKGROUND: Epidemiological evidences support the existence of an effect of airborne particulate on population health. However, few studies evaluated the robustness of the results to different exposure assessment approaches. In this paper, we estimated short term effects and impacts of high levels of particulate matter with aerodynamic diameter ≤10 μm (PM10) and ≤2.5 μm (PM2.5) in the Emilia-Romagna region (Northern Italy), one of the most polluted areas in Europe, in the period 2006-2010, and checked if the results changed when different exposure definitions were used...
February 22, 2017: Environmental Health: a Global Access Science Source
https://www.readbyqxmd.com/read/28222151/bayesian-stock-assessment-of-pacific-herring-in-prince-william-sound-alaska
#15
Melissa L Muradian, Trevor A Branch, Steven D Moffitt, Peter-John F Hulson
The Pacific herring (Clupea pallasii) population in Prince William Sound, Alaska crashed in 1993 and has yet to recover, affecting food web dynamics in the Sound and impacting Alaskan communities. To help researchers design and implement the most effective monitoring, management, and recovery programs, a Bayesian assessment of Prince William Sound herring was developed by reformulating the current model used by the Alaska Department of Fish and Game. The Bayesian model estimated pre-fishery spawning biomass of herring age-3 and older in 2013 to be a median of 19,410 mt (95% credibility interval 12,150-31,740 mt), with a 54% probability that biomass in 2013 was below the management limit used to regulate fisheries in Prince William Sound...
2017: PloS One
https://www.readbyqxmd.com/read/28220096/investigating-a-weakly-informative-prior-for-item-scale-hyperparameters-in-hierarchical-3pno-irt-models
#16
Yanyan Sheng
The half-t family has been suggested for the scale hyperparameter in Bayesian hierarchical modeling. Two parameters define a half-t distribution: the scale s and the degree-of-freedom ν. When s is set at a finite value that is slightly larger than the actual standard deviation of the parameters, the half-t prior density can be vaguely informative. This paper focused on such densities, and applied them to the hierarchical three-parameter item response theory (IRT) model. Monte Carlo simulations were carried out to investigate the performance of such specifications in parameter recovery and model comparisons under situations where the actual variability of item parameters varied, and results suggest that the half-t family does offer advantages over the commonly adopted uniform or inverse-gamma prior density by allowing the variability for item parameters to be either very small or large...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28219774/dynamic-causal-modelling-revisited
#17
K J Friston, Katrin H Preller, Chris Mathys, Hayriye Cagnan, Jakob Heinzle, Adeel Razi, Peter Zeidman
This paper revisits the dynamic causal modelling of fMRI timeseries by replacing the usual (Taylor) approximation to neuronal dynamics with a neural mass model of the canonical microcircuit. This provides a generative or dynamic causal model of laminar specific responses that can generate haemodynamic and electrophysiological measurements. In principle, this allows the fusion of haemodynamic and (event related or induced) electrophysiological responses. Furthermore, it enables Bayesian model comparison of competing hypotheses about physiologically plausible synaptic effects; for example, does attentional modulation act on superficial or deep pyramidal cells - or both? In this technical note, we describe the resulting dynamic causal model and provide an illustrative application to the attention to visual motion dataset used in previous papers...
February 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/28215863/zero-inflated-hierarchical-models-for-faecal-egg-counts-to-assess-anthelmintic-efficacy
#18
Craig Wang, Paul R Torgerson, Johan Höglund, Reinhard Furrer
The prevalence of anthelmintic resistance has increased in recent years, as a result of the extensive use of anthelmintic drugs to reduce the infection of parasitic worms in livestock. In order to detect the resistance, the number of parasite eggs in animal faeces is counted. Typically a subsample of the diluted faeces is examined, and the mean egg counts from both untreated and treated animals are compared. However, the conventional method ignores the variabilities introduced by the counting process and by different infection levels across animals...
February 15, 2017: Veterinary Parasitology
https://www.readbyqxmd.com/read/28215144/in-silico-prediction-of-chemical-toxicity-profile-using-local-lazy-learning
#19
Jing Lu, Pin Zhang, Xiaowen Zou, Xiaoqiang Zhao, Keguang Cheng, Yilei Zhao, Yi Bi, Mingyue Zheng, Xiaomin Luo
Chemical toxicity is an important reason for late-stage failure in drug R&D. However, it is time-consuming and expensive to identify the multiple toxicities of compounds using the traditional experiments. Thus, it is attractive to build an accurate prediction model for the toxicity profile of compounds. In this study, we carried out a research on six types of toxicities: (I) Acute Toxicity; (II) Mutagenicity; (III) Tumorigenicity; (IV) Skin and Eye Irritation; (V) Reproductive Effects; (VI) Multiple Dose Effects, using local lazy learning (LLL) method for multi-label learning...
February 17, 2017: Combinatorial Chemistry & High Throughput Screening
https://www.readbyqxmd.com/read/28214700/uncertainty-estimation-by-bayesian-approach-in-thermochemical-conversion-of-walnut-hull-and-lignite-coal-blends
#20
Musa Buyukada
The main purpose of the present study was to incorporate the uncertainties in the thermal behavior of walnut hull (WH), lignite coal, and their various blends using Bayesian approach. First of all, thermal behavior of related materials were investigated under different temperatures, blend ratios, and heating rates. Results of ultimate and proximate analyses showed the main steps of oxidation mechanism of (co-)combustion process. Thermal degradation started with the (hemi-)cellulosic compounds and finished with lignin...
February 8, 2017: Bioresource Technology
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