keyword
MENU ▼
Read by QxMD icon Read
search

Markov condition

keyword
https://www.readbyqxmd.com/read/28331463/a-gibbs-sampler-for-learning-dags
#1
Robert J B Goudie, Sach Mukherjee
We propose a Gibbs sampler for structure learning in directed acyclic graph (DAG) models. The standard Markov chain Monte Carlo algorithms used for learning DAGs are random-walk Metropolis-Hastings samplers. These samplers are guaranteed to converge asymptotically but often mix slowly when exploring the large graph spaces that arise in structure learning. In each step, the sampler we propose draws entire sets of parents for multiple nodes from the appropriate conditional distribution. This provides an efficient way to make large moves in graph space, permitting faster mixing whilst retaining asymptotic guarantees of convergence...
April 2016: Journal of Machine Learning Research: JMLR
https://www.readbyqxmd.com/read/28329429/racial-disparity-in-life-expectancies-and-life-years-lost-associated-with-multiple-obesity-related-chronic-conditions
#2
Su-Hsin Chang, Yao-Chi Yu, Nils P Carlsson, Xiaoyan Liu, Graham A Colditz
OBJECTIVE: This study investigated racial disparity in life expectancies (LEs) and life years lost (LYL) associated with multiple obesity-related chronic conditions (OCCs). METHODS: Data from the Medical Expenditure Panel Survey, 2008-2012, were used. Four OCCs were studied: diabetes, hypertension, coronary heart disease (CHD), and stroke. LE for each subpopulation was simulated by Markov modelling. LYL associated with a disease for a subpopulation was computed by taking the difference between LEs for members of that subpopulation without disease and LEs for members of that subpopulation who had that disease...
March 22, 2017: Obesity
https://www.readbyqxmd.com/read/28302164/cost-effectiveness-of-cerebrospinal-biomarkers-for-the-diagnosis-of-alzheimer-s-disease
#3
Spencer A W Lee, Luciano A Sposato, Vladimir Hachinski, Lauren E Cipriano
BACKGROUND: Accurate and timely diagnosis of Alzheimer's disease (AD) is important for prompt initiation of treatment in patients with AD and to avoid inappropriate treatment of patients with false-positive diagnoses. METHODS: Using a Markov model, we estimated the lifetime costs and quality-adjusted life-years (QALYs) of cerebrospinal fluid biomarker analysis in a cohort of patients referred to a neurologist or memory clinic with suspected AD who remained without a definitive diagnosis of AD or another condition after neuroimaging...
March 16, 2017: Alzheimer's Research & Therapy
https://www.readbyqxmd.com/read/28294368/estimating-cross-validatory-predictive-p-values-with-integrated-importance-sampling-for-disease-mapping-models
#4
Longhai Li, Cindy X Feng, Shi Qiu
An important statistical task in disease mapping problems is to identify divergent regions with unusually high or low risk of disease. Leave-one-out cross-validatory (LOOCV) model assessment is the gold standard for estimating predictive p-values that can flag such divergent regions. However, actual LOOCV is time-consuming because one needs to rerun a Markov chain Monte Carlo analysis for each posterior distribution in which an observation is held out as a test case. This paper introduces a new method, called integrated importance sampling (iIS), for estimating LOOCV predictive p-values with only Markov chain samples drawn from the posterior based on a full data set...
March 12, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28290281/bioinactivation-software-for-modelling-dynamic-microbial-inactivation
#5
Alberto Garre, Pablo S Fernández, Roland Lindqvist, Jose A Egea
This contribution presents the bioinactivation software, which implements functions for the modelling of isothermal and non-isothermal microbial inactivation. This software offers features such as user-friendliness, modelling of dynamic conditions, possibility to choose the fitting algorithm and generation of prediction intervals. The software is offered in two different formats: Bioinactivation core and Bioinactivation SE. Bioinactivation core is a package for the R programming language, which includes features for the generation of predictions and for the fitting of models to inactivation experiments using non-linear regression or a Markov Chain Monte Carlo algorithm (MCMC)...
March 2017: Food Research International
https://www.readbyqxmd.com/read/28288333/metric-learning-for-parkinsonian-identification-from-imu-gait-measurements
#6
Fabio Cuzzolin, Michael Sapienza, Patrick Esser, Suman Saha, Miss Marloes Franssen, Johnny Collett, Helen Dawes
Diagnosis of people with mild Parkinson's symptoms is difficult. Nevertheless, variations in gait pattern can be utilised to this purpose, when measured via Inertial Measurement Units (IMUs). Human gait, however, possesses a high degree of variability across individuals, and is subject to numerous nuisance factors. Therefore, off-the-shelf Machine Learning techniques may fail to classify it with the accuracy required in clinical trials. In this paper we propose a novel framework in which IMU gait measurement sequences sampled during a 10m walk are first encoded as hidden Markov models (HMMs) to extract their dynamics and provide a fixed-length representation...
February 27, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28269158/detecting-cell-division-of-pseudomonas-aeruginosa-bacteria-from-bright-field-microscopy-images-with-hidden-conditional-random-fields
#7
Lee-Ling S Ong, Xinghua Zhang, Binu Kundukad, Justin Dauwels, Patrick Doyle, H Harry Asada
An approach to automatically detect bacteria division with temporal models is presented. To understand how bacteria migrate and proliferate to form complex multicellular behaviours such as biofilms, it is desirable to track individual bacteria and detect cell division events. Unlike eukaryotic cells, prokaryotic cells such as bacteria lack distinctive features, causing bacteria division difficult to detect in a single image frame. Furthermore, bacteria may detach, migrate close to other bacteria and may orientate themselves at an angle to the horizontal plane...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28262502/investigation-of-the-effects-of-speech-signal-length-on-vocal-disorder-sorting-done-via-dynamic-pattern-modeling
#8
Vida Mehdizadehfar, Farshad Almasganj, Farhad Torabinezhad
OBJECTIVES: Development of a noninvasive method for separating different vocal fold diseases is an important issue concerning vocal analysis. Due to the time variations along a pathologic vocal signal, application of dynamic pattern modeling tools is expected to help in the detection of defects that occur in the speech production mechanism. MATERIALS AND METHODS: In the present study, the hidden Markov model, which is a state space model, is employed to sort some of the vocal diseases...
March 2, 2017: Journal of Voice: Official Journal of the Voice Foundation
https://www.readbyqxmd.com/read/28256925/markov-chain-decision-model-for-urinary-incontinence-procedures
#9
Sameer Kumar, Nidhi Ghildayal, Neha Ghildayal
Purpose Urinary incontinence (UI) is a common chronic health condition, a problem specifically among elderly women that impacts quality of life negatively. However, UI is usually viewed as likely result of old age, and as such is generally not evaluated or even managed appropriately. Many treatments are available to manage incontinence, such as bladder training and numerous surgical procedures such as Burch colposuspension and Sling for UI which have high success rates. The purpose of this paper is to analyze which of these popular surgical procedures for UI is effective...
March 13, 2017: International Journal of Health Care Quality Assurance
https://www.readbyqxmd.com/read/28249400/consensus-in-averager-copier-voter-networks-of-moving-dynamical-agents
#10
Yilun Shang
This paper deals with a hybrid opinion dynamics comprising averager, copier, and voter agents, which ramble as random walkers on a spatial network. Agents exchange information following some deterministic and stochastic protocols if they reside at the same site in the same time. Based on stochastic stability of Markov chains, sufficient conditions guaranteeing consensus in the sense of almost sure convergence have been obtained. The ultimate consensus state is identified in the form of an ergodicity result...
February 2017: Chaos
https://www.readbyqxmd.com/read/28235415/a-systematic-review-of-health-economic-models-of-opioid-agonist-therapies-in-maintenance-treatment-of-non-prescription-opioid-dependence
#11
Mersha Chetty, James J Kenworthy, Sue Langham, Andrew Walker, William C N Dunlop
BACKGROUND: Opioid dependence is a chronic condition with substantial health, economic and social costs. The study objective was to conduct a systematic review of published health-economic models of opioid agonist therapy for non-prescription opioid dependence, to review the different modelling approaches identified, and to inform future modelling studies. METHODS: Literature searches were conducted in March 2015 in eight electronic databases, supplemented by hand-searching reference lists and searches on six National Health Technology Assessment Agency websites...
February 24, 2017: Addiction Science & Clinical Practice
https://www.readbyqxmd.com/read/28231677/-a-systematic-review-of-worldwide-natural-history-models-of-colorectal-cancer-classification-transition-rate-and-a-recommendation-for-developing-chinese-population-specific-model
#12
Z F Li, H Y Huang, J F Shi, C G Guo, S M Zou, C C Liu, Y Wang, L Wang, S L Zhu, S L Wu, M Dai
Objective: To review the worldwide studies on natural history models among colorectal cancer (CRC), and to inform building a Chinese population-specific CRC model and developing a platform for further evaluation of CRC screening and other interventions in population in China. Methods: A structured literature search process was conducted in PubMed and the target publication dates were from January 1995 to December 2014. Information about classification systems on both colorectal cancer and precancer on corresponding transition rate, were extracted and summarized...
February 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28231313/a-stochastic-hybrid-systems-based-framework-for-modeling-dependent-failure-processes
#13
Mengfei Fan, Zhiguo Zeng, Enrico Zio, Rui Kang, Ying Chen
In this paper, we develop a framework to model and analyze systems that are subject to dependent, competing degradation processes and random shocks. The degradation processes are described by stochastic differential equations, whereas transitions between the system discrete states are triggered by random shocks. The modeling is, then, based on Stochastic Hybrid Systems (SHS), whose state space is comprised of a continuous state determined by stochastic differential equations and a discrete state driven by stochastic transitions and reset maps...
2017: PloS One
https://www.readbyqxmd.com/read/28228159/the-effect-of-interspecific-competition-on-the-temporal-dynamics-of-aedes-albopictus-and-culex-pipiens
#14
Giovanni Marini, Giorgio Guzzetta, Frederic Baldacchino, Daniele Arnoldi, Fabrizio Montarsi, Gioia Capelli, Annapaola Rizzoli, Stefano Merler, Roberto Rosà
BACKGROUND: Aedes albopictus and Culex pipiens larvae reared in the same breeding site compete for resources, with an asymmetrical outcome that disadvantages only the latter species. The impact of these interactions on the overall ecology of these two species has not yet been assessed in the natural environment. In the present study, the temporal patterns of adult female mosquitoes from both species were analysed in north-eastern Italy, and substantial temporal shifts between abundance curves of Cx...
February 23, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28227387/detecting-cell-division-of-pseudomonas-aeruginosa-bacteria-from-bright-field-microscopy-images-with-hidden-conditional-random-fields
#15
Lee-Ling S Ong, Xinghua Zhang, Binu Kundukad, Justin Dauwels, Patrick Doyle, H Harry Asada, Lee-Ling S Ong, Xinghua Zhang, Binu Kundukad, Justin Dauwels, Patrick Doyle, H Harry Asada, Binu Kundukad, Lee-Ling S Ong, Xinghua Zhang, Justin Dauwels, Patrick Doyle, H Harry Asada
An approach to automatically detect bacteria division with temporal models is presented. To understand how bacteria migrate and proliferate to form complex multicellular behaviours such as biofilms, it is desirable to track individual bacteria and detect cell division events. Unlike eukaryotic cells, prokaryotic cells such as bacteria lack distinctive features, causing bacteria division difficult to detect in a single image frame. Furthermore, bacteria may detach, migrate close to other bacteria and may orientate themselves at an angle to the horizontal plane...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28224494/modelling-chip-seq-data-using-hmms
#16
Veronica Vinciotti
Chromatin ImmunoPrecipitation-sequencing (ChIP-seq) experiments have now become routine in biology for the detection of protein binding sites. In this chapter, we show how hidden Markov models can be used for the analysis of data generated by ChIP-seq experiments. We show how a hidden Markov model can naturally account for spatial dependencies in the ChIP-seq data, how it can be used in the presence of data from multiple ChIP-seq experiments under the same biological condition, and how it naturally accounts for the different IP efficiencies of individual ChIP-seq experiments...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28222785/tcd4-pos-lymphocytosis-in-rheumatoid-and-psoriatic-arthritis-patients-following-tnf%C3%AE-blocking-agents
#17
Andrea Picchianti Diamanti, Bruno Laganà, Maria Christina Cox, Emanuela Pilozzi, Rachele Amodeo, Maurizio Bove, Milica Markovic, Roberta Di Rosa, Simonetta Salemi, Maria Laura Sorgi, Maria Manuela Rosado, Raffaele D'Amelio
BACKGROUND: Lymphocyte expansion and true lymphocytosis are commonly observed in the everyday clinical practice. The meaning of such phenomenon is often poorly understood so that discrimination between benign and malignant lymphocytosis remains difficult to establish. This is mainly true when lymphocytosis rises in patients affected by immune-mediated chronic inflammatory diseases under immunosuppressive treatment, conditions potentially associated with lymphomagenesis. In this brief report the development of mild T CD4(pos) lymphocytosis in a group of patients with chronic arthritis under anti-TNF-α treatment is described...
February 21, 2017: Journal of Translational Medicine
https://www.readbyqxmd.com/read/28217244/estimating-causal-effects-with-ancestral-graph-markov-models
#18
Daniel Malinsky, Peter Spirtes
We present an algorithm for estimating bounds on causal effects from observational data which combines graphical model search with simple linear regression. We assume that the underlying system can be represented by a linear structural equation model with no feedback, and we allow for the possibility of latent variables. Under assumptions standard in the causal search literature, we use conditional independence constraints to search for an equivalence class of ancestral graphs. Then, for each model in the equivalence class, we perform the appropriate regression (using causal structure information to determine which covariates to include in the regression) to estimate a set of possible causal effects...
August 2016: JMLR Workshop and Conference Proceedings
https://www.readbyqxmd.com/read/28216881/specific-pcr-identification-between-peucedanum-praeruptorum-and-angelica-decursiva-and-identification-between-them-and-adulterant-using-dna-barcode
#19
Bang-Xing Han, Yuan Yuan, Lu-Qi Huang, Qun Zhao, Ling-Ling Tan, Xiang-Wen Song, Xiao-Mei He, Tao Xu, Feng Liu, Jian Wang
BACKGROUND: The traditional Chinese medicine (TCM) Qianhu and Zihuaqianhu are the dried roots of Peucedanum praeruptorum and Angelica decursiva, respectively. Since the plant sources of Qianhu and Zihuaqianhu are more complex, the chemical compositions of P. praeruptorum and A. decursiva are significantly different, and many adulterants exist because of the differences in traditional understanding and medication habits. Therefore, the rapid and accurate identification methods are required...
January 2017: Pharmacognosy Magazine
https://www.readbyqxmd.com/read/28216235/finite-time-stability-and-stabilization-for-stochastic-markov-jump-systems-with-mode-dependent-time-delays
#20
Zhiguo Yan, Yunxia Song, Ju H Park
This paper is concerned with the problems of finite-time stability and stabilization for stochastic Markov systems with mode-dependent time-delays. In order to reduce conservatism, a mode-dependent approach is utilized. Based on the derived stability conditions, state-feedback controller and observer-based controller are designed, respectively. A new N-mode algorithm is given to obtain the maximum value of time-delay. Finally, an example is used to show the merit of the proposed results.
February 16, 2017: ISA Transactions
keyword
keyword
84616
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"