| 1. |
- De Maeyer, Dries, et al.
(författare)
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PheNetic : network-based interpretation of molecular profiling data
- 2015
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Ingår i: Nucleic Acids Research. - : Oxford University Press. - 0305-1048 .- 1362-4962. ; 43:W1, s. 244-250
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Tidskriftsartikel (refereegranskat)abstract
- Molecular profiling experiments have become standard in current wet-lab practices. Classically, enrichment analysis has been used to identify biological functions related to these experimental results. Combining molecular profiling results with the wealth of currently available interactomics data, however, offers the opportunity to identify the molecular mechanism behind an observed molecular phenotype. In this paper, we therefore introduce ‘PheNetic’, a user-friendly web server for inferring a sub-network based on probabilistic logical querying. PheNetic extracts from an interactome, the sub-network that best explains genes prioritized through a molecular profiling experiment. Depending on its run mode, PheNetic searches either for a regulatory mechanism that gave explains to the observed molecular phenotype or for the pathways (in)activated in the molecular phenotype. The web server provides access to a large number of interactomes, making sub-network inference readily applicable to a wide variety of organisms. The inferred sub-networks can be interactively visualized in the browser. PheNetic's method and use are illustrated using an example analysis of differential expression results of ampicillin treated Escherichia coli cells. The PheNetic web service is available at http://bioinformatics.intec.ugent.be/phenetic/.
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| 2. |
- De Maeyer, Dries, et al.
(författare)
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PheNetic : Network-based interpretation of unstructured gene lists in E. coli
- 2013
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Ingår i: Molecular Biosystems. - Cambridge : Royal Society of Chemistry. - 1742-206X .- 1742-2051. ; 9:7, s. 1594-1603
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Tidskriftsartikel (refereegranskat)abstract
- At the present time, omics experiments are commonly used in wet lab practice to identify leads involved in interesting phenotypes. These omics experiments often result in unstructured gene lists, the interpretation of which in terms of pathways or the mode of action is challenging. To aid in the interpretation of such gene lists, we developed PheNetic, a decision theoretic method that exploits publicly available information, captured in a comprehensive interaction network to obtain a mechanistic view of the listed genes. PheNetic selects from an interaction network the sub-networks highlighted by these gene lists. We applied PheNetic to an Escherichia coli interaction network to reanalyse a previously published KO compendium, assessing gene expression of 27 E. coli knock-out mutants under mild acidic conditions. Being able to unveil previously described mechanisms involved in acid resistance demonstrated both the performance of our method and the added value of our integrated E. coli network.
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| 3. |
- Dries, Anton, et al.
(författare)
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ProbLog2 : Probabilistic Logic Programming
- 2015
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Ingår i: Machine Learning and Knowledge Discovery in Databases. - Cham : Springer. - 9783319234601 - 9783319234618 ; , s. 312-315
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Konferensbidrag (refereegranskat)abstract
- We present ProbLog2, the state of the art implementation of the probabilistic programming language ProbLog. The ProbLog language allows the user to intuitively build programs that do not only encode complex interactions between a large sets of heterogenous components but also the inherent uncertainties that are present in real-life situations. The system provides efficient algorithms for querying such models as well as for learning their parameters from data. It is available as an online tool on the web and for download. The offline version offers both command line access to inference and learning and a Python library for building statistical relational learning applications from the system’s components.
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| 4. |
- Fierens, Daan, et al.
(författare)
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Inference and learning in probabilistic logic programs using weighted Boolean formulas
- 2015
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Ingår i: Theory and Practice of Logic Programming. - Cambridge : Cambridge University Press. - 1471-0684 .- 1475-3081. ; 15:3, s. 358-401
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Tidskriftsartikel (refereegranskat)abstract
- Probabilistic logic programs are logic programs in which some of the facts are annotated with probabilities. This paper investigates how classical inference and learning tasks known from the graphical model community can be tackled for probabilistic logic programs. Several such tasks, such as computing the marginals, given evidence and learning from (partial) interpretations, have not really been addressed for probabilistic logic programs before. The first contribution of this paper is a suite of efficient algorithms for various inference tasks. It is based on the conversion of the program and the queries and evidence to a weighted Boolean formula. This allows us to reduce inference tasks to well-studied tasks, such as weighted model counting, which can be solved using state-of-the-art methods known from the graphical model and knowledge compilation literature. The second contribution is an algorithm for parameter estimation in the learning from interpretations setting. The algorithm employs expectation-maximization, and is built on top of the developed inference algorithms. The proposed approach is experimentally evaluated. The results show that the inference algorithms improve upon the state of the art in probabilistic logic programming, and that it is indeed possible to learn the parameters of a probabilistic logic program from interpretations.
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| 5. |
- Renkens, Joris, et al.
(författare)
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Explanation-Based Approximate Weighted Model Counting for Probabilistic Logics
- 2014
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Ingår i: Proceedings of the 28th AAAI Conference on Artificial Intelligence. - : AAAI Press. - 9781577356806 ; , s. 2490-2496
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Konferensbidrag (refereegranskat)abstract
- Probabilistic inference can be realized using weighted model counting. Despite a lot of progress, computing weighted model counts exactly is still infeasible for many problems of interest, and one typically has to resort to approximation methods. We contribute a new bounded approximation method for weighted model counting based on probabilistic logic programming principles. Our bounded approximation algorithm is an anytime algorithm that provides lower and upper bounds on the weighted model count. An empirical evaluation on probabilistic logic programs shows that our approach is effective in many cases that are currently beyond the reach of exact methods.
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| 6. |
- Vlasselaer, Jonas, et al.
(författare)
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Compiling Probabilistic Logic Programs into Sentential Decision Diagrams
- 2014
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Ingår i: Workshop on Probabilistic Logic Programming (PLP). ; , s. 1-10
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Konferensbidrag (refereegranskat)abstract
- Knowledge compilation algorithms transform a probabilistic logic program into a circuit representation that permits efficient probability computation. Knowledge compilation underlies algorithms for exact probabilistic inference and parameter learning in several languages, including ProbLog, PRISM, and LPADs. Developing such algorithms involves a choice, of which circuit language to target, and which compilation algorithm to use. Historically, Binary Decision Diagrams (BDDs) have been a popular target language, whereas recently, deterministic-Decomposable Negation Normal Form (d-DNNF) circuits were shown to outperform BDDs on these tasks. We investigate the use of a new language, called Sentential Decision Diagrams (SDDs), for inference in probabilistic logic programs. SDDs combine desirable properties of BDDs and d-DNNFs. Like BDDs, they support bottom-up compilation and circuit minimization, yet they are a more general and flexible representation. Our preliminary experiments show that compilation to SDD yields smaller circuits and more scalable inference, outperforming the state of the art in ProbLog inference.
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