Sebastian Breuers

A Phylogenomic Approach to Resolve the Arthropod Tree of Life

Arthropods were the first animals to conquer land and air. They encompass more than three quarters of all described living species. This extraordinary evolutionary success is based on an astoundingly wide array of highly adaptive body organizations. A lack of robustly resolved phylogenetic relationships, however, currently impedes the reliable reconstruction of the underlying evolutionary processes. Here, we show that phylogenomic data can substantially advance our understanding of arthropod evolution and resolve several conflicts among existing hypotheses. We assembled a data set of 233 taxa and 775 genes from which an optimally informative data set of 117 taxa and 129 genes was finally selected using new heuristics and compared with the unreduced data set. We included novel expressed sequence tag (EST) data for 11 species and all published phylogenomic data augmented by recently published EST data on taxonomically important arthropod taxa. This thorough sampling reduces the chance of obtaining spurious results due to stochastic effects of undersampling taxa and genes. Orthology prediction of genes, alignment masking tools, and selection of most informative genes due to a balanced taxa-gene ratio using new heuristics were established. Our optimized data set robustly resolves major arthropod relationships. We received strong support for a sister group relationship of onychophorans and euarthropods and strong support for a close association of tardigrades and cycloneuralia. Within pancrustaceans, our analyses yielded paraphyletic crustaceans and monophyletic hexapods and robustly resolved monophyletic endopterygote insects. However, our analyses also showed for few deep splits that were recently thought to be resolved, for example, the position of myriapods, a remarkable sensitivity to methods of analyses.

The MoSGrid Science Gateway - A Complete Solution for Molecular Simulations

The MoSGrid portal offers an approach to carry out high-quality molecular simulations on distributed compute infrastructures to scientists with all kinds of background and experience levels. A user-friendly Web interface guarantees the ease-of-use of modern chemical simulation applications well established in the field. The usage of well-defined workflows annotated with metadata largely improves the reproducibility of simulations in the sense of good lab practice. The MoSGrid science gateway supports applications in the domains quantum chemistry (QC), molecular dynamics (MD), and docking. This paper presents the open-source MoSGrid architecture as well as lessons learned from its design.

A Single Sign-On Infrastructure for Science Gateways on a Use Case for Structural Bioinformatics

Structural bioinformatics applies computational methods to analyze and model three-dimensional molecular structures. There is a huge number of applications available to work with structural data on large scale. Using these tools on distributed computing infrastructures (DCIs), however, is often complicated due to a lack of suitable interfaces. The MoSGrid (Molecular Simulation Grid) science gateway provides an intuitive user interface to several widely-used applications for structural bioinformatics, molecular modeling, and quantum chemistry. It ensures the confidentiality, integrity, and availability of data via a granular security concept, which covers all layers of the infrastructure. The security concept applies SAML (Security Assertion Markup Language) and allows trust delegation from the user interface layer across the high-level middleware layer and the Grid middleware layer down to the HPC facilities. SAML assertions had to be integrated into the MoSGrid infrastructure in several places: the workflow-enabled Grid portal WS-PGRADE (Web Services Parallel Grid Runtime and Developer Environment), the gUSE (Grid User Support Environment) DCI services, and the cloud file system XtreemFS. The presented security infrastructure allows a single sign-on process to all involved DCI components and, therefore, lowers the hurdle for users to utilize large HPC infrastructures for structural bioinformatics.

Standards-based metadata management for molecular simulations

State‐of‐the‐art research in a variety of natural sciences depends heavily on methods of computational chemistry, for example, the calculation of the properties of materials, proteins, catalysts, and drugs. Applications providing such methods require a lot of expertise to handle their complexity and the usage of high‐performance computing. The MoSGrid (molecular simulation grid) infrastructure relieves this burden from scientists by providing a science gateway, which eases access to and usage of computational chemistry applications. One of its cornerstones is the molecular simulations markup language (MSML), an extension of the chemical markup language. MSML abstracts all chemical as well as computational aspects of simulations. An application and its results can be described with common semantics. Using such application, independent descriptions users can easily switch between different applications or compare them. This paper introduces MSML, its integration into a science gateway, and its usage for molecular dynamics, quantum chemistry, and protein docking. Copyright

Molecular simulation grid

MoSGrid is the acronym for Molecular Simulation Grid, a BMBF funded joint research project with the aim to offer grid services for the broad field of molecular simulations in the D-Grid infrastructure. Besides tendering various codes ranging from quantum molecular calculations (e.g. Gaussian, Turbomole) via molecular dynamics (e.g. Gromacs) to docking approaches (e.g. FlexX) for high performance computing, one of the main goals is the integration of metadata annotation for data mining and knowledge generation. Molecular simulation codes and computational resources are accessed via the MoSGrid portal (http://www.mosgrid.de), which will offer intuitive access to various tools and will support the users with workflows, for an easy import of molecular data, a simple setup and submission of calculations as well as extraction of relevant results. The portal will hide the complexity of the underlying technology by providing a unified user interface making computational chemistry in general more readily available. MoSGrid’s server-based portal is available as open-access and open-source software. Users are relieved from software installations and do not need to have knowledge about the underlying infrastructure. The portal includes portlets specifically set up for the various simulation programs. Commonly used workflows, simple or complex, can be stored in recipe repositories and are available for every user. Moreover, users can develop, improve, publish, and use workflows for their everyday tasks.

MoSGrid – a molecular simulation grid as a new tool in computational chemistry, biology and material science

The MoSGrid (Molecular Simulation Grid, http://www. mosgrid.de) project aims to provide remote computational chemistry services within the German Grid Initiative (D-Grid). Submission and monitoring of compute jobs, as well as the retrieval of postprocessed results are realized through a web based portal. The use of standardized portlets and a generally modular approach allows for the simultaneous and independent implementation of frontends for different molecular simulation codes. To date, functional prototypes of portlets for applications from the quantum chemical and the molecular dynamics domain are available, being represented by Gaussian and Gromacs, respectively. The implementation of other quantum chemical codes, as requested by the community, and of codes for docking simulations is in preparation. MoSGrid will furthermore foster efficient and collaborative work by providing secure but shareable repositories for validated data, as well as for reusable recipes and workflows [1-3].

MoSGrid: efficient data management and a standardized data exchange format for molecular simulations in a grid environment

The MoSGrid (Molecular Simulation Grid) project is currently establishing a platform that aims to be used by both experienced and inexperienced researchers to submit molecular simulation calculations, monitor their progress, and retrieve the results. It provides a web-based portal to easily set up, run, and evaluate molecular simulations carried out on D-Grid resources. The range of applications available encompasses quantum chemistry, molecular dynamics, and protein-ligand docking codes. In addition, data repositories were developed, which contain the results of calculations as well as “recipes” or workflows. These can be used, improved, and distributed by the users. A distributed high-throughput file system allows efficient access to large amounts of data in the repositories. For storing both the input and output of the calculations, we have developed MSML (Molecular Simulation Markup Language), a CML derivative (Chemical Markup Language). MSML has been designed to store structural information on small as well as large molecules and results from various molecular simulation tools and docking tools. It ensures interoperability of different tools through a consistent data representation. At http://www.mosgrid.de the new platform is already available to the scientific community in a beta test phase. Currently, portlets for generic workflows, Gaussian, and Gromacs applications are publicly accessible [1,2].

SuGI - Portal and Training Systems for Grid Middlewares

Grid computing is a research and development topic, currently getting much attention. As a result, new ideas as well as research and project results are being produced at a very high rate. Therefore, it is difficult for resource providers and researchers in this area to keep track of the development. Resource providers and researchers, new to the topic of Grid computing, have to overcome a huge inhibition threshold before work in this area can be started. The SuGI project is aiming to support providers and researchers with two approaches. First, the SuGI portal presents videos, documents, and links regarding many topics in the area of Grid computing for newcomers as well as for experts. Second, the training systems for Grid middlewares created by the SuGI project can help beginners to do their first steps without a complex installation process, while experts can easily try out different configurations without interfering with their productive systems.

MoSGrid: Progress of Workflow driven Chemical Simulations

Motivation: Web-based access to computational chemistry grid resources has proven to be a viable approach to simplify the use of simulation codes. The introduction of recipes allows to reuse already developed chemical workflows. By this means, workflows for recurring basic compute jobs can be provided for daily services. Nevertheless, the same platform has to be open for active workflow development by experienced users. This paper provides an overview of recent developments of the MoSGrid project on providing tools and instruments for building workflow recipes. Contact: birke@uni-paderborn.de

The MoSGrid - e-science gateway: molecular simulations in a distributed computing environment

Modern tools for computational chemistry allow the calculation of a wide range of properties of all sorts of molecules applying various levels of theory. But to perform convincing and significant calculations with these tools not only requires insight into the scientific theory itself, but also knowledge and experience on how to operate the simulation tools. In addition to the general challenge of gaining access to a powerful computing environment, very often a high level of technical competence is necessary to set up and run calculations efficiently. These prerequisites often hamper scientists to routinely use computational tools to support or confirm their perceptions. To overcome some of these problems, the MoSGrid consortium develops an open source e-science portal for grid based environments with respect to computational chemistry. At present residing in the German Grid Initiative (D-Grid), MoSGrid enables users to set up, run and evaluate calculations using tools from the domains of Quantum Chemistry, Molecular Dynamics and Docking [1]. This talk underlines the basic motivation, layout, development, properties and available tools of MoSGrid as well as the procedure of gaining access to the grid environment.