ERC FUNDED PROJECTS

Extreme astrophysical events such as relativistic flows, cataclysmic explosions and black hole accretion are one of the key areas for astrophysics in the 21st century. The extremes of physics experienced in these environments are beyond anything achievable in any laboratory on Earth, and provide a unique glimpse at the laws of physics operating in extraordinary regimes. All of these events are associated with transient radio emission, a tracer both of the acceleration of particles to relativistic energies, and coherent emitting regions with huge effective temperatures. By studying radio bursts from these phenomena we can pinpoint the sources of explosive events, understand the budget of kinetic feedback by explosive events in the ambient medium, and probe the physical state of the universe back to the epoch of reionisation, less than a billion years after the big bang. In seeking to push back the frontiers of extreme astrophysics, I will use a trio of revolutionary new radio telescopes, LOFAR, ASKAP and MeerKAT, pathfinders for the Square Kilometre Array, and all facilities in which I have a major role in the search for transients. I will build an infrastructure which transforms their combined operations for the discovery, classification and reporting of transient astrophysical events, over the whole sky, making them much more than the sum of their parts. This will include development of environments for the coordinated handling of extreme astrophysical events, in real time, via automated systems, as well as novel techniques for the detection of these events in a sea of noise. I will furthermore augment this program by buying in as a major partner to a rapid-response robotic optical telescope, and by cementing my relationship with an orbiting X-ray facility. This multiwavelength dimension will secure the astrophysical interpretation of our observational results and help to revolutionise high-energy astrophysics via a strong scientific exploitation program.

2 999 847 €

Start date: 2011-07-01, End date: 2017-06-30

Quantum chemistry provides two approaches to molecular electronic-structure calculations: the systematically refinable but expensive many-body wave-function methods and the inexpensive but not systematically refinable Kohn Sham method of density-functional theory (DFT). The accuracy of Kohn Sham calculations is determined by the quality of the exchange correlation functional, from which the effects of exchange and correlation among the electrons are extracted using the density rather than the wave function. However, the exact exchange correlation functional is unknown—instead, many approximate forms have been developed, by fitting to experimental data or by satisfying exact relations. Here, a new approach to density-functional analysis and construction is proposed: the Lieb variation principle, usually regarded as conceptually important but impracticable. By invoking the Lieb principle, it becomes possible to approach the development of approximate functionals in a novel manner, being directly guided by the behaviour of exact functional, accurately calculated for a wide variety of chemical systems. In particular, this principle will be used to calculate ab-initio adiabatic connection curves, studying the exchange correlation functional for a fixed density as the electronic interactions are turned on from zero to one. Pilot calculations have indicated the feasibility of this approach in simple cases—here, a comprehensive set of adiabatic-connection curves will be generated and utilized for calibration, construction, and analysis of density functionals, the objective being to produce improved functionals for Kohn Sham calculations by modelling or fitting such curves. The ABACUS approach will be particularly important in cases where little experimental information is available—for example, for understanding and modelling the behaviour of the exchange correlation functional in electromagnetic fields.

2 017 932 €

Start date: 2011-03-01, End date: 2016-02-29

Global change involves a large number of complex interactions between various earth system processes. In the atmosphere, one component of the earth system, there are crucial feedbacks between physical, chemical and biological processes. Thus many of the drivers of climate change depend on chemical processes in the atmosphere including, in addition to ozone and water vapour, methane, nitrous oxide, the halocarbons as well as a range of inorganic and organic aerosols. The link between chemistry and climate is two-way and changes in climate can influence atmospheric chemistry processes in a variety of ways. Previous studies have looked at these interactions in isolation but the time is now right for more comprehensive studies. The crucial contribution that will be made here is in improving our understanding of the processes within this complex system. Process understanding has been the hallmark of my previous work. The earth system scope here will be ambitiously wide but with a similar drive to understand fundamental processes. The ambitious programme of research is built around four interrelated questions using new state-of-the-art modelling tools: How will the composition of the stratosphere change in the future, given changes in the concentrations of ozone depleting substances and greenhouse gases? How will these changes in the stratosphere affect tropospheric composition and climate? How will the composition of the troposphere change in the future, given changes in the emissions of ozone precursors and greenhouse gases? How will these changes in the troposphere affect the troposphere-stratosphere climate system? ACCI will break new ground in bringing all of these questions into a single modelling and diagnostic framework, enabling interrelated questions to be answered which should radically improve our overall projections for global change.

2 496 926 €

Start date: 2011-05-01, End date: 2017-04-30

MAL: an actin-regulated SRF transcriptional coactivator Recent years have seen a revitalised interest in the role of actin in nuclear processes, but the molecular mechanisms involved remain largely unexplored. We will elucidate the molecular basis for the actin-based control of the SRF transcriptional coactivator, MAL. SRF controls transcription through two families of coactivators, the actin-binding MRTFs (MAL, Mkl2), which couple its activity to cytoskeletal dynamics, and the ERK-regulated TCFs (Elk-1, SAP-1, Net). MAL subcellular localisation and transcriptional activity responds to signal-induced changes in G-actin concentration, which are sensed by its actin-binding N-terminal RPEL domain. Members of a second family of RPEL proteins, the Phactrs, also exhibit actin-regulated nucleocytoplasmic shuttling. The proposal addresses the following novel features of actin biology: ¿ Actin as a transcriptional regulator ¿ Actin as a signalling molecule ¿ Actin-binding proteins as targets for regulation by actin, rather than regulators of actin function We will analyse the sequences and proteins involved in actin-regulated nucleocytoplasmic shuttling, using structural biology and biochemistry to analyse its control by changes in actin-RPEL domain interactions. We will characterise the dynamics of shuttling, and develop reporters for changes in actin-MAL interaction for analysis of pathway activation in vivo. We will identify genes controlling MAL itself, and the balance between the nuclear and cytoplasmic actin pools. The mechanism by which actin represses transcriptional activation by MAL in the nucleus, and its relation to MAL phosphorylation, will be elucidated. Finally, we will map MRTF and TCF cofactor recruitment to SRF targets on a genome-wide scale, and identify the steps in transcription controlled by actin-MAL interaction.

1 889 995 €

Start date: 2011-10-01, End date: 2017-09-30