109 research outputs found
An introduction to spectral distances in networks (extended version)
Many functions have been recently defined to assess the similarity among
networks as tools for quantitative comparison. They stem from very different
frameworks - and they are tuned for dealing with different situations. Here we
show an overview of the spectral distances, highlighting their behavior in some
basic cases of static and dynamic synthetic and real networks
Stability Indicators in Network Reconstruction
The number of algorithms available to reconstruct a biological network from a
dataset of high-throughput measurements is nowadays overwhelming, but
evaluating their performance when the gold standard is unknown is a difficult
task. Here we propose to use a few reconstruction stability tools as a
quantitative solution to this problem. We introduce four indicators to
quantitatively assess the stability of a reconstructed network in terms of
variability with respect to data subsampling. In particular, we give a measure
of the mutual distances among the set of networks generated by a collection of
data subsets (and from the network generated on the whole dataset) and we rank
nodes and edges according to their decreasing variability within the same set
of networks. As a key ingredient, we employ a global/local network distance
combined with a bootstrap procedure. We demonstrate the use of the indicators
in a controlled situation on a toy dataset, and we show their application on a
miRNA microarray dataset with paired tumoral and non-tumoral tissues extracted
from a cohort of 241 hepatocellular carcinoma patients
The HIM glocal metric and kernel for network comparison and classification
Due to the ever rising importance of the network paradigm across several
areas of science, comparing and classifying graphs represent essential steps in
the networks analysis of complex systems. Both tasks have been recently tackled
via quite different strategies, even tailored ad-hoc for the investigated
problem. Here we deal with both operations by introducing the
Hamming-Ipsen-Mikhailov (HIM) distance, a novel metric to quantitatively
measure the difference between two graphs sharing the same vertices. The new
measure combines the local Hamming distance and the global spectral
Ipsen-Mikhailov distance so to overcome the drawbacks affecting the two
components separately. Building then the HIM kernel function derived from the
HIM distance it is possible to move from network comparison to network
classification via the Support Vector Machine (SVM) algorithm. Applications of
HIM distance and HIM kernel in computational biology and social networks
science demonstrate the effectiveness of the proposed functions as a general
purpose solution.Comment: Frontiers of Network Analysis: Methods, Models, and Applications -
NIPS 2013 Worksho
Minerva and minepy: a C engine for the MINE suite and its R, Python and MATLAB wrappers
We introduce a novel implementation in ANSI C of the MINE family of
algorithms for computing maximal information-based measures of dependence
between two variables in large datasets, with the aim of a low memory footprint
and ease of integration within bioinformatics pipelines. We provide the
libraries minerva (with the R interface) and minepy for Python, MATLAB, Octave
and C++. The C solution reduces the large memory requirement of the original
Java implementation, has good upscaling properties, and offers a native
parallelization for the R interface. Low memory requirements are demonstrated
on the MINE benchmarks as well as on large (n=1340) microarray and Illumina
GAII RNA-seq transcriptomics datasets.
Availability and Implementation: Source code and binaries are freely
available for download under GPL3 licence at http://minepy.sourceforge.net for
minepy and through the CRAN repository http://cran.r-project.org for the R
package minerva. All software is multiplatform (MS Windows, Linux and OSX).Comment: Bioinformatics 2012, in pres
A Version of Jung’s Synchronicity in the Event of Correlation of Mental Processes in the Past and the Future: Possible Role of Quantum Entanglement in Quantum Vacuum
This paper deals with the version of Jung’s synchronicity in which correlation between mental processes of two different
persons takes place not just in the case when at a certain moment of time the subjects are located at a distance from each
other, but also in the case when both persons are alternately (and sequentially, one after the other) located in the same point
of space. In this case, a certain period of time lapses between manifestation of mental process in one person and manifestation
of mental process in the other person. Transmission of information from one person to the other via classical communication
channel is ruled out. The author proposes a hypothesis, whereby such manifestation of synchronicity may become possible
thanks to existence of quantum entanglement between the past and the future within the light cone. This hypothesis is based
on the latest perception of the nature of quantum vacuu
stormTB: a web-based simulator of a murine minimal-PBPK model for anti-tuberculosis treatments
IntroductionTuberculosis (TB) poses a significant threat to global health, with millions of new infections and approximately one million deaths annually. Various modeling efforts have emerged, offering tailored data-driven and physiologically-based solutions for novel and historical compounds. However, this diverse modeling panorama may lack consistency, limiting result comparability. Drug-specific models are often tied to commercial software and developed on various platforms and languages, potentially hindering access and complicating the comparison of different compounds.MethodsThis work introduces stormTB: SimulaTOr of a muRine Minimal-pbpk model for anti-TB drugs. It is a web-based interface for our minimal physiologically based pharmacokinetic (mPBPK) platform, designed to simulate custom treatment scenarios for tuberculosis in murine models. The app facilitates visual comparisons of pharmacokinetic profiles, aiding in assessing drug-dose combinations.ResultsThe mPBPK model, supporting 11 anti-TB drugs, offers a unified perspective, overcoming the potential inconsistencies arising from diverse modeling efforts. The app, publicly accessible, provides a user-friendly environment for researchers to conduct what-if analyses and contribute to collective TB eradication efforts. The tool generates comprehensive visualizations of drug concentration profiles and pharmacokinetic/pharmacodynamic indices for TB-relevant tissues, empowering researchers in the quest for more effective TB treatments. stormTB is freely available at the link: https://apps.cosbi.eu/stormTB
Reverse Engineering Gene Networks with ANN: Variability in Network Inference Algorithms
Motivation :Reconstructing the topology of a gene regulatory network is one
of the key tasks in systems biology. Despite of the wide variety of proposed
methods, very little work has been dedicated to the assessment of their
stability properties. Here we present a methodical comparison of the
performance of a novel method (RegnANN) for gene network inference based on
multilayer perceptrons with three reference algorithms (ARACNE, CLR, KELLER),
focussing our analysis on the prediction variability induced by both the
network intrinsic structure and the available data.
Results: The extensive evaluation on both synthetic data and a selection of
gene modules of "Escherichia coli" indicates that all the algorithms suffer of
instability and variability issues with regards to the reconstruction of the
topology of the network. This instability makes objectively very hard the task
of establishing which method performs best. Nevertheless, RegnANN shows MCC
scores that compare very favorably with all the other inference methods tested.
Availability: The software for the RegnANN inference algorithm is distributed
under GPL3 and it is available at the corresponding author home page
(http://mpba.fbk.eu/grimaldi/regnann-supmat
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