19,501 research outputs found
Information-theoretic analysis of multivariate single - cell signaling responses using SLEMI
Mathematical methods of information theory constitute essential tools to
describe how stimuli are encoded in activities of signaling effectors.
Exploring the information-theoretic perspective, however, remains conceptually,
experimentally and computationally challenging. Specifically, existing
computational tools enable efficient analysis of relatively simple systems,
usually with one input and output only. Moreover, their robust and readily
applicable implementations are missing. Here, we propose a novel algorithm to
analyze signaling data within the framework of information theory. Our approach
enables robust as well as statistically and computationally efficient analysis
of signaling systems with high-dimensional outputs and a large number of input
values. Analysis of the NF-kB single - cell signaling responses to TNF-a
uniquely reveals that the NF-kB signaling dynamics improves discrimination of
high concentrations of TNF-a with a modest impact on discrimination of low
concentrations. Our readily applicable R-package, SLEMI - statistical learning
based estimation of mutual information, allows the approach to be used by
computational biologists with only elementary knowledge of information theory
Functional Mixture Discriminant Analysis with hidden process regression for curve classification
We present a new mixture model-based discriminant analysis approach for
functional data using a specific hidden process regression model. The approach
allows for fitting flexible curve-models to each class of complex-shaped curves
presenting regime changes. The model parameters are learned by maximizing the
observed-data log-likelihood for each class by using a dedicated
expectation-maximization (EM) algorithm. Comparisons on simulated data with
alternative approaches show that the proposed approach provides better results.Comment: In Proceedings of the XXth European Symposium on Artificial Neural
Networks, Computational Intelligence and Machine Learning (ESANN), Pages
281-286, 2012, Bruges, Belgiu
Platonic model of mind as an approximation to neurodynamics
Hierarchy of approximations involved in simplification of microscopic theories, from sub-cellural to the whole brain level, is presented. A new approximation to neural dynamics is described, leading to a Platonic-like model of mind based on psychological spaces. Objects and events in these spaces correspond to quasi-stable states of brain dynamics and may be interpreted from psychological point of view. Platonic model bridges the gap between neurosciences and psychological sciences. Static and dynamic versions of this model are outlined and Feature Space Mapping, a neurofuzzy realization of the static version of Platonic model, described. Categorization experiments with human subjects are analyzed from the neurodynamical and Platonic model points of view
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