Darren Marvin

Taverna: a tool for the composition and enactment of bioinformatics workflows

MOTIVATION In silico experiments in bioinformatics involve the co-ordinated use of computational tools and information repositories. A growing number of these resources are being made available with programmatic access in the form of Web services. Bioinformatics scientists will need to orchestrate these Web services in workflows as part of their analyses. RESULTS The Taverna project has developed a tool for the composition and enactment of bioinformatics workflows for the life sciences community. The tool includes a workbench application which provides a graphical user interface for the composition of workflows. These workflows are written in a new language called the simple conceptual unified flow language (Scufl), where by each step within a workflow represents one atomic task. Two examples are used to illustrate the ease by which in silico experiments can be represented as Scufl workflows using the workbench application.

On the use of agents in a BioInformatics grid

My Grid is an e-Science Grid project that aims to help biologists and bioinformaticians to perform workflow-based in silico experiments, and help them to automate the management of such workflows through personalisation, notification of change and publication of experiments. In this paper, we describe the architecture of my Grid and how it will be used by the scientist. We then show how my Grid can benefit from agents technologies. We have identified three key uses of agent technologies in my Grid: user agents, able to customize and personalise data, agent communication languages offering a generic and portable communication medium, and negotiation allowing multiple distributed entities to reach service level agreements.

Delivering web service coordination capability to users

As web service technology matures there is growing interest in exploiting workflow techniques to coordinate web services. Bioinformaticians are a user community who combine web resources to perform in silico experiments. These users are scientists and not information technology experts they require workflow solutions that have a low cost of entry for service users and providers. Problems satisfying these requirements with current techniques led to the development of the Simple conceptual unified flow language (Scufl). Scufl is supported by the Freefluo enactment engine [1], and the Taverna editing workbench [3]. The extensibility of Scufl, supported by these tools, means that workflows coordinating web services can be matched to how users view their problems. The Taverna workbench exploits the web to keep Scufl simple by retrieving detail from URIs when required, and by scavenging the web for services. Scufl and its tools are not bioinformatics specific. They can be exploited by other communities who require user-driven composition and execution of workflows coordinating web resources.

ECSES – examining crystal structures using `e-science': a demonstrator employing web and grid services to enhance user participation in crystallographic experiments

An application of e-science methodology and grid networking technology is presented that opens up new possibilities to enhance the operation of large high-throughput service-crystallography facilities, exemplified by the UK National Crystallography Service (NCS). A seamless distributed computing approach is used to provide remote secure visualization, monitoring and interaction with the laboratory and the diffraction experiment, supervision and input to the data workup and analysis processes, and to enable dissemination and further use of the resulting structural data. The architecture of the system is based on web and grid services (in particular the use of Globus, v1.1.4), which provide a secure environment for two-way information flow and communication between the service users and operators. This capability will enhance operations of instrument and software automation by providing more efficient use of the resources, increasing the throughput of samples and enabling interactions with distributed chemistry information databases, computational services and networks. The viability of these interactions is assessed and directions for future crystallography services suggested. The setup would be equally applicable to protein or powder crystallography services.

Semantic web service interaction protocols: an ontological approach

A central requirement for achieving the vision of run-time discovery and dynamic composition of services is the provision of appropriate descriptions of the operation of a service, that is, how the service interacts with agents or other services. In this paper, we use experience gained through the development of real-life Grid applications to produce a set of requirements for such descriptions and then attempt to match those requirements against the offerings of existing work, such as OWL-S [1] and IRS-II [2]. Based on this analysis we identify which requirements are not addressed by current research and, in response, produce a model for describing the interaction protocol of a service in response. The main contributions of this model are the ability to describe the interactions of multiple parties with respect to a single service, distinguish between interactions initiated by the service itself and interactions that are initiated by clients or other cooperating services, and capture within the description service state changes relevant to interacting parties that are either a result of internal service events or interactions. The aim of the model is not to replace existing work, since it only focuses on the description of the interaction protocol of a service, but to inform the further development of such work.