Dynamic Bayesian Networks (DBNs) can serve as succinct probabilistic dynamic models of biochemical networks. To analyze these models, one must compute the probability distribution over system states at a given time point. Doing this exactly is infeasible for large models; hence one must use approximate algorithms. The Factored Frontier algorithm (FF) is one such algorithm. However FF as well as the earlier Boyen-Koller (BK) algorithm can incur large errors. To address this, we present a new approximate algorithm called the Hybrid Factored Frontier (HFF) algorithm. At each time slice, in addition to maintaining probability distributions over local states-as FF does-HFF explicitly maintains the probabilities of a number of global states called spikes. When the number of spikes is 0, we get FF and with all global states as spikes, we get the exact inference algorithm. We show that by increasing the number of spikes one can reduce errors while the additional computational effort required is only quadratic in the number of spikes. We validated the performance of HFF on large DBN models of biopathways. Each pathway has more than 30 species and the corresponding DBN has more than 3,000 nodes. Comparisons with FF and BK show that HFF is a useful and powerful approximate inferencing algorithm for DBNs.

Download full-text PDF

Source
http://dx.doi.org/10.1109/TCBB.2012.60DOI Listing

Publication Analysis

Top Keywords

factored frontier
12
number spikes
12
hybrid factored
8
algorithm
8
frontier algorithm
8
dynamic bayesian
8
bayesian networks
8
global states
8
spikes
5
algorithm dynamic
4

Similar Publications

A search for the exclusive hadronic decays W^{±}→π^{±}γ, W^{±}→K^{±}γ, and W^{±}→ρ^{±}γ is performed using up to 140  fb^{-1} of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of sqrt[s]=13  TeV. If observed, these rare processes would provide a unique test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders. Additionally, at future colliders, these decays could offer a new way to measure the W boson mass through fully reconstructed decay products.

View Article and Find Full Text PDF

Artificial water regulation and natural flood processes control heavy metal concentrations and transport in the Yellow River, China.

Mar Pollut Bull

December 2024

Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266071, China; College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, China. Electronic address:

Based on heavy metals daily observation at the Lijin station during water-sediment regulation (WSR) event and three natural floods in 2020, we examined the effects of different flood events on heavy metal in lower Yellow River, China. The results revealed that due to different water and sediment sources and processes influencing heavy metals dynamics, the dissolved Cr, Zn As and particulate heavy metals during natural flood events were higher than those during WSR event. Dissolved heavy metals increased during water regulation and decreased during sediment regulation.

View Article and Find Full Text PDF

Aims: This study aimed to investigate the role of gamma-aminobutyric acid (GABA) in the glioblastoma (GBM) tumor immune microenvironment (TIME) and its impact on prognosis and response to immunotherapy.

Main Methods: This study employed single-cell RNA sequencing (scRNA-seq) to delineate the TIME of GBM, utilized non-negative matrix factorization (NMF) for GABA-associated cell clustering, and performed pseudotime analysis for cellular trajectories. Additionally, we integrated immunohistochemistry (IHC), immunofluorescence (IF), and protein-protein interaction (PPI) analysis to explore the regulatory mechanisms within the tumor microenvironment.

View Article and Find Full Text PDF

PM anomaly detection for exceptional event demonstrations: A Texas case study.

J Air Waste Manag Assoc

November 2024

R&D, Verisk Atmospheric and Environmental Research, Lexington, MA, USA.

The shifting frontiers of air pollution emission sources contribute to stagnation or reversal of air quality gains across the United States (US). The frequency and possible duration of Exceptional Events - driven primarily by wildfires and dust storms - have significantly increased in the US over the past decade. Combined with the US Environmental Protection Agency (EPA) final rule strengthening primary annual National Ambient Air Quality Standards (NAAQS) for PM by 25%, communities will need to reevaluate domestic and international sources of PM.

View Article and Find Full Text PDF

Single-cell RNA sequencing (scRNA-seq) has emerged as a powerful tool in genomics research, enabling the analysis of gene expression at the individual cell level. However, scRNA-seq data often suffer from a high rate of dropouts, where certain genes fail to be detected in specific cells due to technical limitations. This missing data can introduce biases and hinder downstream analysis.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!