Computing graphlet signatures of network nodes and motifs in Cytoscape with GraphletCounter

Biological network analysis can be enhanced by examining the connections between nodes and the rest of the network. For this purpose we have developed GraphletCounter, an open-source software tool for computing graphlet degree signatures that can operate on its own or as a plug-in to the network analysis environment Cytoscape. A unique characteristic of GraphletCounter is its ability to compute the graphlet signatures of network motifs, which can be specified by files generated by the motif-finding tool mfinder. GraphletCounter displays graphlet signatures for visual inspection within Cytoscape, and can output graphlet data for integration with larger workflows. AVAILABILITY AND IMPLEMENTATION: GraphletCounter is implemented in Java. It can be downloaded from the Cytoscape plugin repository, and is also available at http://sonmezsysbio.org/software/ graphletcounter.     

GOlorize: a Cytoscape plug-in for network visualization with Gene Ontology-based layout and coloring

We have implemented a graph layout algorithm that exposes Gene Ontology (GO) class structure on the network nodes. It can be used in conjunction with BiNGO plug-in to Cytoscape, which finds the GO categories over-represented in a given network. Our plug-in, named GOlorize, first highlights the class members with category-specific color-coding and then constructs an enhanced visualization of the network using a class-directed layout algorithm. Availability: http://www.cytoscape.org/plugins2.php. Supplementary information: Installation instructions and tutorial at http://www.cytoscape.org/plugins/GOlorize/GOlorizeUserGuide.pdf.     

Storing biological sequence databases in relational form

SUMMARY: We have created a set of applications using Perl and Java in combination with XML technology to install biological sequence databases into an Oracle RDBMS. An easy-to-use interface using Java has been created for database query and other tools developed to integrate with our in-house bioinformatics applications. AVAILIBILITY: The database schema, DTD file, and source codes are available from the authors via email. CONTACT: guochun_ xie@merck. com     

CytoITMprobe: a network information flow plugin for Cytoscape

ABSTRACT: BACKGROUND: Cytoscape is a well-developed flexible platform for visualization, integration and analysis of network data. Apart from the sophisticated graph layout and visualization routines, it hosts numerous user-developed plugins that significantly extend its core functionality. Earlier, we developed a network information flow framework and implemented it as a web application, called ITM Probe. Given a context consisting of one or more user-selected nodes, ITM Probe retrieves other network nodes most related to that context. It requires neither user restriction to subnetwork of interest nor additional and possibly noisy information. However, plugins for Cytoscape with these features do not yet exist. To provide the Cytoscape users the possibility of integrating ITM Probe into their workflows, we developed CytoITMprobe, a new Cytoscape plugin. FINDINGS: CytoITMprobe maintains all the desirable features of ITM Probe and adds additional flexibility not achievable through its web service version. It provides access to ITM Probe either through a web server or locally. The input, consisting of a Cytoscape network, together with the desired origins and/or destinations of information and a dissipation coefficient, is specified through a query form. The results are shown as a subnetwork of significant nodes and several summary tables. Users can control the composition and appearance of the subnetwork and interchange their ITM Probe results with other software tools through tab-delimited files. CONCLUSIONS: The main strength of CytoITMprobe is its flexibility. It allows the user to specify as input any Cytoscape network, rather than being restricted to the pre-compiled protein-protein interaction networks available through the ITM Probe web service. Users may supply their own edge weights and directionalities. Consequently, as opposed to ITM Probe web service, CytoITMprobe can be applied to many other domains of network-based research beyond protein-networks. It also enables seamless integration of ITM Probe results with other Cytoscape plugins having complementary functionality for data analysis.     

Cytoscape 2.8: new features for data integration and network visualization

Cytoscape is a popular bioinformatics package for biological network visualization and data integration. Version 2.8 introduces two powerful new features--Custom Node Graphics and Attribute Equations--which can be used jointly to greatly enhance Cytoscape's data integration and visualization capabilities. Custom Node Graphics allow an image to be projected onto a node, including images generated dynamically or at remote locations. Attribute Equations provide Cytoscape with spreadsheet-like functionality in which the value of an attribute is computed dynamically as a function of other attributes and network properties. Availability and implementation: Cytoscape is a desktop Java application released under the Library Gnu Public License (LGPL). Binary install bundles and source code for Cytoscape 2.8 are available for download from http://cytoscape.org.     

YAdumper: extracting and translating large information volumes from relational databases to structured flat files

Downloading the information stored in relational databases into XML and other flat formats is a common task in bioinformatics. This periodical dumping of information requires considerable CPU time, disk and memory resources. YAdumper has been developed as a purpose-specific tool to deal with the integral structured information download of relational databases. YAdumper is a Java application that organizes database extraction following an XML template based on an external Document Type Declaration. Compared with other non-native alternatives, YAdumper substantially reduces memory requirements and considerably improves writing performance.     

Data mining and predictive modeling of biomolecular network from biomedical literature databases

In this paper, we present a novel approach Bio-IEDM (biomedical information extraction and data mining) to integrate text mining and predictive modeling to analyze biomolecular network from biomedical literature databases. Our method consists of two phases. In phase 1, we discuss a semisupervised efficient learning approach to automatically extract biological relationships such as protein-protein interaction, protein-gene interaction from the biomedical literature databases to construct the biomolecular network. Our method automatically learns the patterns based on a few user seed tuples and then extracts new tuples from the biomedical literature based on the discovered patterns. The derived biomolecular network forms a large scale-free network graph. In phase 2, we present a novel clustering algorithm to analyze the biomolecular network graph to identify biologically meaningful subnetworks (communities). The clustering algorithm considers the characteristics of the scale-free network graphs and is based on the local density of the vertex and its neighborhood functions that can be used to find more meaningful clusters with different density level. The experimental results indicate our approach is very effective in extracting biological knowledge from a huge collection of biomedical literature. The integration of data mining and information extraction provides a promising direction for analyzing the biomolecular network     

Domain fusion analysis by applying relational algebra to protein sequence and domain databases

Background  

Domain fusion analysis is a useful method to predict functionally linked proteins that may be involved in direct protein-protein interactions or in the same metabolic or signaling pathway. As separate domain databases like BLOCKS, PROSITE, Pfam, SMART, PRINTS-S, ProDom, TIGRFAMs, and amalgamated domain databases like InterPro continue to grow in size and quality, a computational method to perform domain fusion analysis that leverages on these efforts will become increasingly powerful.     

CyClus3D: a Cytoscape plugin for clustering network motifs in integrated networks

SUMMARY: Network motifs in integrated molecular networks represent functional relationships between distinct data types. They aggregate to form dense topological structures corresponding to functional modules which cannot be detected by traditional graph clustering algorithms. We developed CyClus3D, a Cytoscape plugin for clustering composite three-node network motifs using a 3D spectral clustering algorithm. AVAILABILITY: Via the Cytoscape plugin manager or http://bioinformatics.psb.ugent.be/software/details/CyClus3D.     

Challenges to be faced in the reconstruction of metabolic networks from public databases

In the post-genomic era, the biochemical information for individual compounds, enzymes, reactions to be found within named organisms has become readily available. The well-known KEGG and BioCyc databases provide a comprehensive catalogue for this information and have thereby substantially aided the scientific community. Using these databases, the complement of enzymes present in a given organism can be determined and, in principle, used to reconstruct the metabolic network. However, such reconstructed networks contain numerous properties contradicting biological expectation. The metabolic networks for a number of organisms are reconstructed from KEGG and BioCyc databases, and features of these networks are related to properties of their originating database.     

structureViz: linking Cytoscape and UCSF Chimera

structureViz is a Cytoscape plug-in that links the visualization of biological networks provided by Cytoscape with the visualization and analysis of macromolecular structures and sequences provided by UCSF Chimera. When combined with Cytoscape and Chimera, structureViz provides the first tool that links these two critical aspects of computational analysis in a straightforward manner. structureViz includes commands to open structures in Chimera and align them using Chimera's sequence-structure analysis tools. When a structure is opened, structureViz provides an alternative interface to Chimera: the Cytoscape Molecular Structure Navigator. This interface uses a tree-based paradigm to allow users to select and affect the display of models, chains and residues, mostly through the use of context menus.     

The Make 2D-DB II package: conversion of federated two-dimensional gel electrophoresis databases into a relational format and interconnection of distributed databases

The Make 2D-DB tool has been previously developed to help build federated two-dimensional gel electrophoresis (2-DE) databases on one's own web site. The purpose of our work is to extend the strength of the first package and to build a more efficient environment. Such an environment should be able to fulfill the different needs and requirements arising from both the growing use of 2-DE techniques and the increasing amount of distributed experimental data.     

Clust&See: A Cytoscape plugin for the identification,visualization and manipulation of network clusters

Background and scope

Large networks, such as protein interaction networks, are extremely difficult to analyze as a whole. We developed Clust&See, a Cytoscape plugin dedicated to the identification, visualization and analysis of clusters extracted from such networks.

Implementation and performance

Clust&See provides the ability to apply three different, recently developed graph clustering algorithms to networks and to visualize: (i) the obtained partition as a quotient graph in which nodes correspond to clusters and (ii) the obtained clusters as their corresponding subnetworks. Importantly, tools for investigating the relationships between clusters and vertices as well as their organization within the whole graph are supplied.     

IMIRS: a high-resolution 3D reconstruction package integrated with a relational image database

Recent advances in electron cryomicroscopy instrumentation and single particle reconstruction have created opportunities for high-throughput and high-resolution three-dimensional (3D) structure determination of macromolecular complexes. However, it has become impractical and inefficient to rely on conventional text file data management and command-line programs to organize and process the increasing numbers of image data required in high-resolution studies. Here, we present a distributed relational database for managing complex datasets and its integration into our high-resolution software package IMIRS (Image Management and Icosahedral Reconstruction System). IMIRS consists of a complete set of modular programs for icosahedral reconstruction organized under a graphical user interface and provides options for user-friendly, step-by-step data processing as well as automatic reconstruction. We show that the integration of data management with processing in IMIRS automates the tedious tasks of data management, enables data coherence, and facilitates information sharing in a distributed computer and user environment without significantly increasing the time of program execution. We demonstrate the applicability of IMIRS in icosahedral reconstruction toward high resolution by using it to obtain an 8-A 3D structure of an intermediate-sized dsRNA virus.     

Flexible authorization in home network environments

In home network environments, OSGi platform plays a major role as the service gateway to access into home appliances. It is important to provide appropriate services as well as security mechanisms to protect confidential or sensitive information and devices. Authorization is especially important when controlling the access of different users. OSGi platform supports the role based access control but it does not support various facilities in the RBAC model. To address such shortcomings, several works have proposed the enhanced access control mechanisms for the OSGi service platform. However, these are still limited to applying the traditional RBAC conventions to OSGi platform. This paper extends the existing authorization mechanism of OSGi platform to address its limitations for dynamic deployments. By adding the relative role concept and activating the access control using the delegation model, proposed mechanism enables a diverse and outstanding access control. We implement the proposed mechanism using aspectJ and illustrate how to develop a bundle including access control logic.