The CombineArchiveWeb application { A web based tool to handle les associated with modelling results

Abstract

Sharing in silico experiments is essential for the advance of research in computational biology. Consequently, the COMBINE archive was designed as a digital container format. It eases the management of les related to a modelling result, fosters collaboration, and ultimately enables the exchange of reproducible simulation studies. However, manual handling of COMBINE archives is tedious and error prone. We therefore developed the CombineArchiveWeb application to support scientists in promoting and publishing their research by means of creating, exploring, modifying, and sharing archives. All les are equipped with meta data and can be distributed over the Web through shareable workspaces.

Introduction

Computational modelling is an indispensable tool in the life sciences. As a consequence, standardisation and exchange of models has also become essential. However, the steadily increasing size and complexity of models and derived data poses the challenge of sharing reproducible results. Today's results typically consist of multiple model les with semantic annotations, simulation descriptions linked to terms in a simulation algorithm ontology, structure information, result data sets with semantic annotations, and reference publications [ 1 ]. Only if all relevant les are provided, modelling results can be reliably reproduced and sharing becomes feasible.

To solve this issue, the COMBINE community [ 2 ] proposes the COMBINE archive format [ 3 ]. A COMBINE archive is a container that bundles all les related to a project into a single le. Typically, the COMBINE archive also comprises les with meta data such as people attributions and details about les inside the archive. The meta data is encoded in XML/RDF. For example, VCards refer to contributors and DCTERMS capture creation and modi cation dates. The meta data can be used to de ne relations among the les contained in the archive. It can also be evaluated to query and compare COMBINE archives, or to quickly get an overview of the content without necessarily loading the single les. An example is given in Figure 1. The les included in an archive are listed ? To whom correspondence should be addressed and their meta data are displayed in a human readable format. In this example, the archive contains information about the results from Liebal et. al [ 4 ]: a model description in SBML format, a simulation description in SED-ML format, the reference publication in PDF format and two data tables. Viewing and modifying meta data is easily possible through the forms on the right hand side.

In summary, the COMBINE archive is a solid format for sharing reproducible models and in silico experiments with collaborators and public databases.

However, manual handling of COMBINE archives is tedious and error prone. Therefore, we developed a CombineArchive Toolkit (http://sems.uni-rostock. de/cat). It consists of a library, a desktop application, and a web based interface.

The CombineArchiveLibrary1 is written in Java and implements the COMBINE archive speci cation [ 5 ]. It o ers all necessary methods to handle COMBINE archives, including:

Extracting single les or the whole archive Browsing through the archive Adding and removing les Renaming and reorganising les Attaching and retrieving meta information

The CombineArchiveLibrary is for tool developers. It has already been integrated with software such as the Functional Curation Project of Chaste [ 6 ].

We also integrated the CombineArchiveLibrary in the CombineArchiveDesktop application2. It is intended as a functional browser for COMBINE archives. One of the application's key features is the user-friendly handling of included meta data. The meta data is presented in a human readable way and can easily be modi ed. Since the desktop application only runs locally, your les do not leave your machine. This is especially important when data protection or intellectual property claims are of concern. The CombineArchiveDesktop application is implemented in Java and shipped as an executable Java Archive (JAR) le. Thus, it is portable and runs on Windows, Linux, and MacOS.

The second software tool is the CombineArchiveWeb application. It is described in the following.

The CombineArchiveWeb application

The CombineArchiveWeb application3 also uses the CombineArchiveLibrary as a code base. It enables any researcher to work with the COMBINE archive format on the internet. Additionally, the application o ers RESTful services for use by other client applications. The web interface connects to open model repositories, such as the CellML model repository [ 8 ], to easily retrieve models. User with special interest in privacy do not need to alienate their research. Since the 1 sems.uni-rostock.de/trac/combinearchive 2 sems.uni-rostock.de/trac/combinearchive-gui 3 webcat.sems.uni-rostock.de CombineArchiveWeb application is openly available and easy to install, anyone could host their own instances on private servers. In order to prohibit abuse, the maintainer of an installation can easily con gure quotas for the users. For example, it is possible to limit the maximum le size, the maximum age of an untouched archive, the number of archives per workspace, the number of les in an archive, just to name a few options. Since the CombineArchiveWeb application is not intended as a database for long-term storage of simulation studies old archives are deleted regularly.

Researchers who wish to share their results through the CombineArchiveWeb application can simply upload all relevant les belonging to a piece of modelling work. This automatically creates a workspace. Workspaces are an ideal tool to manage les. They foster collaborations and prevent inconsistencies in versions of les. Uploaded les are immediately bundled in a COMBINE archive. Such virtual experiments can be downloaded at any time and from any location. The created workspace can also be shared with collaborators to work from di erent physical locations. The CombineArchiveWeb application supports researchers in exploring and reproducing scienti c results. For example, authors of a publication may decide to provide their code as a COMBINE archive. When consumers open the archive, the CombineArchiveWeb application automatically reads the les and their meta data. It builds the links between the various les and presents the contents in a human readable format (see again Figure 1).

Summary

The CombineArchive Toolkit implements the latest COMBINE archive speci cation and, thus, breathes life into the idea of sharing all les necessary to reproduce an in silico experiment. We present a web based, graphical user interface for interacting with COMBINE archives. The CombineArchiveWeb application grants users intuitive access to COMBINE archives. Our tools and code are openly available through our project website at sems.uni-rostock.de/cat. We invite you to use our software, to provide feedback and suggestions, and to contribute to the further development of the CombineArchive Toolkit.

References

1. Waltemath et al.: Possibilities for Integrating Model-related Data in Computational Biology . In: Proceedings of the 9th International Conference on Data Integration in the Life Sciences. CEUR Workshops , 2013 .

2. Le Novere et al.: Meeting report from the rst meetings of the Computational Modeling in Biology Network (COMBINE) . Standards in genomic sciences , 2011 .

3. Bergmann et al.: COMBINE archive: One File To Share Them All . arXiv, 2014 .

4. Liebal et al.: Proteolysis of beta-galactosidase following SigmaB activation in Bacillus subtilis . Molecular BioSystems , 2012 .

5. Bergmann et al.: COMBINE Archive Speci cation , 2014 .

6. Cooper et al.: High-throughput functional curation of cellular electrophysiology models . Progress in Biophysics and Molecular Biology , 2011 .

7. Li et al.: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models . BMC Systems Biology , 2010 .

8. Lloyd et al.: The CellML Model Repository . Bioinformatics, 2008 .