Reconstruction and simulation of neocortical microcircuitry

We present a first-draft digital reconstruction of the microcircuitry of somatosensory cortex of juvenile rat. The reconstruction uses cellular and synaptic organizing principles to algorithmically reconstruct detailed anatomy and physiology from sparse experimental data. An objective anatomical method defines a neocortical volume of 0.29 ± 0.01 mm3 containing ∼31,000 neurons, and patch-clamp studies identify 55 layer-specific morphological and 207 morpho-electrical neuron subtypes. When digitally reconstructed neurons are positioned in the volume and synapse formation is restricted to biological bouton densities and numbers of synapses per connection, their overlapping arbors form ∼8 million connections with ∼37 million synapses. Simulations reproduce an array of in vitro and in vivo experiments without parameter tuning. Additionally, we find a spectrum of network states with a sharp transition from synchronous to asynchronous activity, modulated by physiological mechanisms. The spectrum of network states, dynamically reconfigured around this transition, supports diverse information processing strategies

A design environment for mobile applications

In this paper we show how high-level UML models of mobile computing applications can be analysed for classical performance measures such as throughput. The approach proceeds by compiling the UML model into a representation in the formally-defined modelling language of PEPA nets. The compilation process and subsequent performance analysis based on numerical solution of a Continuous-Time Markov Chain is supported by a software tool, the Choreogra-pher design platform. Choreographer interoperates with popular UML tools by reading and writing UML models in the XML Metadata Interchange format (XMI).

PEPA nets in practice: modelling a decentralised peer-to-peer emergency medial application

Abstract. We apply the PEPA nets modelling language to modelling a peer-topeer medical informatics application, the FieldCare PDA-based medical records system developed by SINTEF Telecom and Informatics, Norway. Medical data on accident victims is entered by medics on handheld devices at the crash site and propagated wirelessly from peer to peer in order to improve information flow and reduce the potential for data loss. The benefits of such a system include improved reliability in patient care and the ability for hospitals to prepare better for incoming trauma patients. The effectiveness and usefulness of the system in practice depends upon both reliability and performance issues. We analyse the functioning of the application through a high-level model expressed in the PEPA nets modelling language, a coloured stochastic Petri net in which the tokens are terms of Hillston’s Performance Evaluation Process Algebra (PEPA). We use the PRISM probabilistic model checker to solve the model and evaluate probabilistically quantified formulae which quantify the responsiveness of the system.

Choreographing security and performance analysis. DEGAS project paper. Submitted for publication

Abstract. We describe a UML-based method which supports model-driven development of service-oriented architectures including those used in Web services. Analysable content is extracted from the UML models in the form of process calculus descriptions. These are analysed to provide strong guarantees of satisfactory security and performance. The results are reflected back in the form of a modified version of the UML model which highlights points of the design which can give rise to operational difficulties. A design platform supporting the methodology, Choreographer, interoperates with state-of-the-art UML modelling tools such as Poseidon. We illustrate the approach on an example.

A design environment for mobile applications

In this paper we show how high-level UML models of mobile computing applications can be analysed for classical performance measures such as throughput. The approach proceeds by compiling the UML model into a representation in the formally-defined modelling language of PEPA nets. The compilation process and subsequent performance analysis based on numerical solution of a Continuous-Time Markov Chain is supported by a software tool, the Choreographer design platform. Choreographer interoperates with popular UML tools by reading and writing UML models in the XML Metadata Interchange format (XMI).

Scipy Lecture Notes: One document to learn numerics, science, and data with Python

International audienceTutorials on the scientific Python ecosystem: a quick introduction to central tools and techniques. The different chapters each correspond to a 1 to 2 hours course with increasing level of expertise, from beginner to expert