ERC FUNDED PROJECTS

The main objective nowadays in the field of biomaterials is to design highly performing bioinspired materials learning from natural processes. Importantly, biochemical and physical cues are key parameters that can affect cellular processes. Controlling processes that occur at the cell/material interface is also of prime importance to guide the cell response. The main aim of the current project is to develop novel functional bio-nanomaterials for in vitro biological studies. Our strategy is based on two related projects. The first project deals with the rational design of smart films with foreseen applications in musculoskeletal tissue engineering. We will gain knowledge of key cellular processes by designing well defined self-assembled thin coatings. These multi-functional surfaces with bioactivity (incorporation of growth factors), mechanical (film stiffness) and topographical properties (spatial control of the film s properties) will serve as tools to mimic the complexity of the natural materials in vivo and to present bioactive molecules in the solid phase. We will get a better fundamental understanding of how cellular functions, including adhesion and differentiation of muscle cells are affected by the materials s surface properties. In the second project, we will investigate at the molecular level a crucial aspect of cell adhesion and motility, which is the intracellular linkage between the plasma membrane and the cell cytoskeleton. We aim to elucidate the role of ERM proteins, especially ezrin and moesin, in the direct linkage between the plasma membrane and actin filaments. Here again, we will use a well defined microenvironment in vitro to simplify the complexity of the interactions that occur in cellulo. To this end, lipid membranes containing a key regulator lipid from the phosphoinositides familly, PIP2, will be employed in conjunction with purified proteins to investigate actin regulation by ERM proteins in the presence of PIP2-membranes.

1 499 996 €

Start date: 2011-06-01, End date: 2016-05-31

Cell motility is essential for many biological processes, including development and pathogenesis. Thus, the molecular mechanisms underlying this process have been intensively studied in many cell systems, for example, leukocytes, amoeba and even bacteria. Intriguingly, bacteria are also able to move across solid surfaces (gliding motility) like eukaryotic cells by a process that has remained largely mysterious. The emergence of bacterial cell biology: the discovery that the bacterial cell also has a dynamic cytoskeleton and specialized subcellular regions now provides new research angles to study the motility mechanism. Using cell biology approaches, we previously suggested that the mechanism may be akin to acto-myosin-based motility in eukaryotic cells and proposed that bacterial focal adhesion complexes also power locomotion. In this project, we propose two complementary research axes to define both the mechanism and its spatial regulation in the cell at molecular resolution. Using the model motility bacterium Myxococcus xanthus, we first propose to develop a “toolbox” of biophysical and cell biology assays to analyze the motility process. Specifically, we will construct a Traction Force Microscopy assay designed to image the motility forces directly by live moving cells and use microfluidics to quantitate the secretion of a mucus that may participate directly in the motility process. These assays, combined with a newly developed laser trap system to visualize dynamic focal adhesions in the cell envelope, will be instrumental not only to define new features of the motility process, but also to study the function of novel motility genes which may encode the components of the elusive motility engine. This way, we hope to establish the mechanism and structure function relationships within an entirely novel motility machinery. In a second part, we propose to investigate the mechanism that controls a polarity switch, allowing M. xanthus cells to change their direction of movement. We have previously shown that dynamic motility protein pole-to-pole oscillations convert the initial leading cell pole into the lagging pole. Here, we propose that like in a eukaryotic cells, a bacterial counterpart of small GTPases of the Ras superfamily, MglA controls the polarity cycle. To test this hypothesis, we will study both the MglA upstream regulation and the MglA downstream effectors. We thus hope to establish a model of dynamic polarity control in a bacterial

1 437 693 €

Start date: 2011-01-01, End date: 2015-12-31

The formation of dark matter structures in our Universe can be explained by the standard cosmological model, but the populations of galaxies observed in the distant and nearby Universe pose major challenges to our understanding of galaxy formation. There is increasing recognition that the visible, baryonic part of galaxies does not passively follow the hierarchical build-up of dark halos. A large part of the baryons can be accreted from cold gas flows along the cosmic web. The evolution of galaxies could then be mostly driven by their internal evolution, in addition to interactions and mergers. Many scall-scale processes with major effects on galaxy evolution have been unveiled. They have, however, been studied mostly one by one, ignoring the large-scale cosmological environment. Conversely, cosmological models do not resolve the small-scale internal processes properly yet. This dramatically limits our understanding of galaxy formation. The project is to develop an multi-scale understanding of galaxy formation. We will build comprehensive numerical models of the small-scale gas physics and star formation processes in, and incorporate them in large-scale cosmological simulations. Taking benefit from the best forthcoming computing facilities, this will develop a new understanding of the role of internal physics and external processes in structuring galaxies. Theoretical predictions will be confronted to observations, preparing and using the next generation of instruments along the whole duration of the project. Owing to a uniquely comprehensive approach including physical processes at different scales and an original combination of theory, simulation and observation, a new understanding of the evolution of the baryons through cosmic times can emerge from the project.

988 400 €

Start date: 2011-02-01, End date: 2016-01-31

Microcavity polaritons are half-light, half-matter composite bosons, which are formed in monolithic semiconductor microcavities of the proper design. Recently, Bose-Einstein condensation of polaritons has been reported, that constitutes a new class of quantum fluid out of equilibrium. Unlike cold atoms, superfluid Helium or superconductors, polaritons are in a driven-dissipative situation, and their mass amounts only to a negligible fraction of an electrons’. This unusual situation has already revealed very interesting phenomena. Moreover, every observables of the polariton fluid, including momentum, energy spectrum and coherence properties are directly accessed via optical spectroscopy experiments. In this project, we will fabricate and investigate new wide band-gap semiconductor nanostructures both capable of taking unprecedented control over the polariton environment, and capable of sustaining very hot and very dense quantum degenerate polariton fluids. Various confinement configurations - two, one and zero-dimensional -will be realized as well as advanced nanostructures based on traps and tunnel barriers. In these peculiar situations, the quantum degenerate polariton fluid will display a new and rich phenomenology. Hence, many premieres will be achieved like room temperature 1D quantum degeneracy, 1D quasi-condensate in solid-state systems, Josephson oscillations of polariton superfluids, and the fascinating Tonks-Girardeau state where strongly interacting bosons are expected to behave like fermions.

1 488 307 €

Start date: 2010-11-01, End date: 2015-10-31

In biological systems many tissue types have evolved a barrier function to selectively allow the transport of matter from the lumen to tissue beneath. Characterization of these barriers is very important as their disruption or malfunction is often indicative of toxicity/disease. The degree of barrier integrity is also a key indicator of the appropriateness of in vitro models for use in toxicology/drug screening. The advent of organic electronics has created a unique opportunity to interface the worlds of electronics and biology, using devices such as the organic electrochemical transistor (OECT), that provides a very sensitive way to detect minute ionic currents. This proposal aims to integrate the barrier function of biological systems with OECTs to yield devices that can detect minute disruptions in barrier function. Specifically, OECTs will be integrated with cell monolayers that form tight junctions and with membranes that incorporate ion channels. A disruption in tight junctions or a change in permeability of ion channels will be detected by the OECT. These devices will have unprecedented sensitivity, in a format that can be mass produced at low-cost. The potential benefits of this multidisciplinary project are numerous: It will be a vehicle for fundamental research in life sciences and the development of new in vitro models for toxicology screening of disruptive agents and the development of drugs to treat disorders linked with barrier tissue malfunction (e.g. mutations in ion channels). Moreover, through the use of various cell lines and ion channels, this platform will also lead to the engineering of new sensors and biomedical instrumentation, with a host of applications in medical diagnostics, food/water safety, homeland security and environmental protection.

1 496 539 €

Start date: 2011-04-01, End date: 2016-03-31

The storage density of computer hard drives is growing so rapidly that for new computer drive generations not only optimized materials are needed but also new concepts for data storage. Last decades, higher storage densities on computer disks were achieved by optimization of magnetic materials, i.e. the magnetic grains were gradually shrunk while, at the same time, the magnetic stability was increased. The nowadays smallest storage unit is made up 100 to 600 grains, that form one bit. Each grain is about 10 nanometres in size. These grains are arranged next to each other on substrates that are plated with magnetic metals. Decreasing further the size and amount of the grains necessary for one bit is now irremediably affecting the signal/noise ratio, weaker signals leading to loss of information. Therefore, new concepts for magnetic storage media have to be found. Material reduced size leads to novel properties totally different from bulk properties. In our project we will engineer matter at the atomic and molecular level and develop advanced construction methods to build new functionalised materials for magnetic storage. We propose a multidisciplinary research project, that aims to explore various aspects related to magnetic properties of highly organised organic-inorganic nano-architectures. We will engineer tunable supramolecular assemblies to host and organise inorganic shape-selected magnetic nanocrystals. Due to the sensitive interrelation of magnetism and the atomic structure of these systems, any induced nanostructure modification will result in changes of the magnetism. Our ability to tailor nanocrystal size, composition, structure, shape and position will allow us to tune magnetism at the atomic scale. We will thus be able to design and produce new high density hybrid nano-architectures having gigantic magnetic performance, i.e., huge magnetostatic energy stored and a high blocking temperature. This research therefore has the potential to make a considerable impact on the high density data storage industry

1 499 725 €

Start date: 2010-11-01, End date: 2016-10-31

General anaesthesia is an important method in today's hospital practice and especially in surgery. To supervise the depth of anaesthesia during surgery, the anaesthesist applies electroencephalography (EEG) and monitors the brain activity of the subject on the scalp. The applied monitoring machine calculates the change of the power spectrum of the brain signals to indicate the anaesthetic depth. This procedure is based on the finding that the concentration increase of the anaesthetic drug changes the EEG-power spectrum in a significant way. Although this procedure is applied world-wide, the underlying neural mechanism of the spectrum change is still unknown. The project aims to elucidate the underlying neural mechanism by a detailed investigating a mathematical model of neural populations. The investigation is based on analytical calculations in a neural population model of the cortex involving intrinsic neural properties of brain areas and feedback loops to other areas, such as the loop between the cortex and the thalamus. Currently, there are two proposed mechanisms for the charactertisic change of the power spectrum: a highly nonlinear jump in the activation (so-called phase transition) and a linear behavior. The project mainly focusses on the nonlinear jump to finally rule it out or support it. A subsequent comparison to previous experimenta results aims to fit the physiological parameters. Since the cortex population is embedded into a network of other cortical areas and the thalamus, the corresponding analytical investigations takes into account external stochastic (from other brain areas) and time-periodic (thalamic) forces. To this end it is necessary to develop several novel nonlinear analysis technique of neural populations to derive the power spectrum close to the phase transition and conditions for physiological parameters.

856 500 €

Start date: 2011-01-01, End date: 2015-10-31

Understanding electronic correlations remains one of the biggest challenges of theoretical condensed matter physics. Mesoscopic systems, where electronic confinement can be externally controlled, are natural test beds for understanding the effects of correlations, and the lack of proper techniques to take them into account is acute. This project aims at developing new tools for simulating correlated quantum mesoscopic devices. We will combine standard approaches for transport in mesoscopic quantum systems with new quantum Monte-Carlo algorithms designed to capture correlations in those devices. We will use modern programming paradigms to develop a versatile numerical platform designed to be easily used by other research groups. These numerical tools will be closely related to existing analytical approaches so that we shall be able to make contact with standard many-body theory while go beyond the limitations of the analytical approaches. We will apply this new set of techniques to several problems that have been puzzling the community for some time including quantum transport in low-density two-dimensional gases for both bulk disordered systems (“Two dimensional metal-insulator transition”) and quantum point contacts (“0.7 anomaly”). We will also apply our techniques to several new problems of increasing importance: at finite-frequency, electron-electron interactions play a central role and must be taken into account properly. We will discuss high frequency measurements such as quantum capacitances, ac conductance or photo-assisted transport in a variety of materials (twodimensional gases of electrons or holes, graphene, semi-conductor nanowires…) and leverage on our new numerical tools to go beyond the standard mean field description.

1 222 176 €

Start date: 2011-01-01, End date: 2015-12-31

The purpose of the project is to study linear and nonlinear models arising in quantum mechanics and which are used to describe matter at the microscopic and nanoscopic scales. The project focuses on physically-oriented questions (rigorous derivation of a given model from first principles), analytic problems (existence and properties of bound states, study of solutions to timedependent equations) and numerical issues (development of reliable algorithmic strategies). Most of the models are nonlinear and describe physical systems possessing an infinite number of quantum particles, leading to specific difficulties. The first part of the project is devoted to the study of relativistic atoms and molecules, while taking into account quantum electrodynamics effects like the polarization of the vacuum. The models are all based on the Dirac operator. The second part is focused on the study of quantum crystals. The goal is to develop new strategies for describing their behavior in the presence of defects and local deformations. Both insulators, semiconductors and metals are considered (including graphene). In the third part, attractive systems are considered (like stars or a few nucleons interacting via strong forces in a nucleus). The project aims at rigorously understanding some of their specific properties, like Cooper pairing or the possible dynamical collapse of massive gravitational objects. Finally, the last part is devoted to general properties of infinite quantum systems, in particular the proof of the existence of the thermodynamic limit

905 700 €

Start date: 2010-10-01, End date: 2015-09-30

These last fifty years have seen Von Neumann computing architectures boom. Nevertheless, even the most powerful digital computers cannot rapidly solve apparently simple problems such as image interpretation. However, because its structure is massively parallel and analog, the human brain is able to perform such tasks in a fraction of second. Neuromorphic circuits allow to go beyond conventional digital architectures. An on-chip implementation of these circuits requires to be able to fabricate nanometer sized, analog, reconfigurable, fast components. While the spiking neurons can easily be fabricated with classical CMOS technology, the synapse plasticity is challenging to achieve. In 1971 L. Chua has introduced a new circuit element, called memristor , a non-linear resistance which by definition includes a memory effect. Only last year, a team in Hewlett-Packard has for the first time proposed a device for synaptic applications showing memristive properties based on electromigration of oxygen vacancies in Titanium Oxide. The project NanoBrain aims first at developing alternative memristors based on different physical principles (spintronics and ferroelectricity), avoiding in particular the potential over-heating and fragility of the electromigration-based devices. The final goal of the project is to prove the efficiency of these new nano-synapses by integrating them into functional neural networks.

1 495 803 €

Start date: 2010-11-01, End date: 2015-10-31

The objective of this project is to explore novel phenomena of heavy fermion systems. The focus will be on low temperature novel properties such as quantum criticality, unconventional superconductivity and multipole ordering, which will leads to new horizon not only of heavy fermion physics, but also of material science. We will concentrate on: (1) new materials and high quality single crystals, (2) precise temperature-pressure-field (T,P,H) phase diagrams, (3) quantum singularities and Fermiology, (4) the mechanism of unconventional superconductivity including ferromagnetic superconductor, (5) field-induced phenomena. To reach our targets, we will first attempt to grow many new compounds based on U, Ce, Yb and other rare earth elements with a careful choice of target, using various techniques. Very high quality single crystals can be a breakthrough in this field of research, in particular for unconventional superconductivity. Then, we will measure their low temperature properties with various experimental techniques under extreme conditions, namely low temperature, high field, high pressure. Activities of material growth and studies of their properties will be coordinated in order to provide rapid a feedback. This work will be comforted by theoretical work. To carry out specific experiments, we will develop a new AC calorimetry system under extreme conditions and a de Haas-van Alphen (dHvA) measurement system. With this experimental method, we aim to directly observe the heavy electronic state. This is a major issue to clarify the possible Fermi surface instability at quantum singularities. The high quality samples will be supplied to other groups in order to extend our macroscopic and microscopic experimental multi approach.

1 500 000 €

Start date: 2010-11-01, End date: 2015-10-31

Gamma-ray Astronomy pinpoints celestial high energy particle accelerators and may reveal the origin of the cosmic-rays, a century after their discovery. Now is a time of extraordinary opportunity. Cherenkov telescopes have opened up a new domain and more than 70 very-high energy gamma-ray sources have been detected above 100 GeV, especially by the European experiments H.E.S.S. and MAGIC. NASA's Fermi Large Area Telescope, devoted to the study of the gamma-ray sky between 20 MeV and 300 GeV, was launched in June 2008 and has published the positions of 1500 previously unknown gamma-ray sources spread across the sky. However, among all the sources detected by satellite and Cherenkov telescopes, hundreds of Galactic gamma-ray sources have no obvious counterpart at optical, radio, or X-ray wavelengths. What are these sources ? What role do they play in the Galaxy's energy budget ? Many of them must be pulsars or nebulae powered by pulsars. In this project, I propose to use my expertise in both TeV and GeV gamma-ray analysis together with the excellent links of our team with radio observatories to identify the nature of these sources, focusing on pulsars and pulsar wind nebulae as primary candidates. I further propose to use the theoretical models of these cosmic accelerators that I have developed in the past both to enhance the search, and to interpret the results. The range of competences required for the proposed research project is very large and difficult to gather in one single team: pulsar timing, experience with data analysis of extended sources and theoretical know-how in pulsar wind nebulae and high energy phenomena. The P-WIND team would therefore be unique in gamma-ray Astronomy.

592 680 €

Start date: 2011-01-01, End date: 2013-12-31

The main goal of this proposal to the ERC Starting Grant scheme is to make ground-breaking progress in our understanding of the dynamical processes that shape the structure of protoplanetary disks. This will be achieved by performing state-of-the-art high resolution numerical simulations of protoplanetary disks, using novel computing techniques and taking advantage of the future European petascale supercomputers. The project will address the following fundamental questions in accretion disks theory: - What are the properties of MHD turbulence in protoplanetary disks? - What are the effects of radiative processes on protoplanetary disks structure? - What are the consequences of dead zones for protoplanetary disk structure? In addition, the project will look for potential observational signatures of these processes that might be detected by ALMA. Since planetary systems like our own are believed to emerge from protoplanetary disks, the project will make decisive contributions in describing the structure of the environment in which planetary systems form, the interest of which extends to the entire planet formation community.

1 093 152 €

Start date: 2011-09-01, End date: 2016-08-31

This project is dedicated to the study of two distinct classes of dynamical systems which display a quasiperiodic component. The first class consists of quasiperiodic cocycles, and we will largely focus on connections with the spectral theory of quasiperiodic Schrodinger operators. Up to very recently, our understanding had been mostly restricted to situations where the potential would have some clear characteristics of large or small potentials. In particular, no genuinely global theory had been devised that could go so far as give insight on the phase-transition between large-like and small-like potentials. With the introduction by the PI of techniques to analyze the parameter dependence of one-frequency potentials which involve much less control of the dynamics of associated cocycles, and the discovery of new regularity features of this dependence, it is now possible to elaborate a precise conjectural global picture, whose proof is one of the major goals of the project. The second class consists of translation flows on higher genus surfaces. The Teichmuller flow acts as renormalization in this class, and its chaotic features have permitted a detailed description of the dynamics of typical translation flows. This project will concentrate on the the development of techniques suitable to the analysis of non-typical families of translation flows, which arise naturally in the context of certain applications, as for rational billiards. We aim to obtain results regarding the spectral gap for restrictions of the SL(2,R action, the existence of polynomial deviations outside exceptional cases, and the weak mixing property for certain billiards.

1 020 840 €

Start date: 2010-12-01, End date: 2015-11-30

The following list of questions describe the four main directions which I want to develop. 1) Topology of real uniruled manifolds. May the connected sum of two closed hyperbolic manifolds of dimension at least three be Lagrangian embedded in a uniruled symplectic manifold? Being able to answer to this question through the negative using the symplectic field theory introduced by Eliashberg-Givental and Hofer requires to understand pseudo-holomorphic curves in the cotangent bundle of such a connected sum. For this purpose, one needs some understanding of closed geodesics on such manifolds. Conversely, what are the simplest real three-dimensional projective manifolds which have hyperbolic or SOL manifolds in their real loci? 2) Enumerative problems in real uniruled manifolds. Is it possible to extract integer valued invariants from the count of real rational curves of given degree in the projective three-space (for instance) which interpolate an adequate number of real lines? Same question in dimensions greater than three for curves passing through points. 3) Lagrangian strings in symplectic manifolds. I would like to investigate the interactions between closed Lagrangian strings and open Lagrangian strings in symplectic manifolds. These strings -which I recently introduced- interact through holomorphic disks both punctured on their boundaries and interiors. What can be the analogous TQFT associated to coherent sheaves on complex projective manifolds? How are these strings related to Gromov-Witten invariants? 4) Volume of linear systems of real divisors. The theory of closed positive currents provides probabilistic informations on the topology of real hypersurfaces in Kähler manifolds. I want to push a work in progress as far as possible in this subject.

932 626 €

Start date: 2010-12-01, End date: 2015-11-30

Sequence-controlled polymerizations play a key role in Nature. Although formed from a rather modest library of monomers, sequence-defined macromolecules such as proteins or nucleic acids are largely responsible for the complexity and diversity of the biological world. By analogy, one may predict that synthetic sequence-defined polymers could play an important role in modern applied materials science. Paradoxically, very little effort has been spent within the last decades for developing sequence-specific polymerization methods. In this scientific context, the target of the present proposal is to develop new approaches for controlling macromolecular sequences. In particular, new possibilities for controlling comonomer sequences in standard synthetic processes such as chain-growth polymerizations (e.g. controlled radical polymerization) and step-growth polymerizations will be investigated. The strategies for controlling sequences will be principally chemical (e.g. controlled monomer insertion, organocatalysis, sequential monomer additions) but physical (e.g. confinement, transient monomer complexation) and eventually biochemical (e.g. biocatalysis) routes will be also considered. The essence of this project is indeed highly fundamental. Indeed, the control over polymer sequences remains one of the last holy grails in polymer science. Nevertheless, on a longer term, this research may be also extremely relevant for applications. Indeed, sequence-controlled polymers are most likely the key towards new generations of functional sub-nanometric materials.

1 200 000 €

Start date: 2010-11-01, End date: 2014-10-31

The goal of this project is to study the topology of Stein manifolds from the viewpoint of symplectic and contact geometry. It addresses the fundamental questions of the subject: - How does the Lagrangian skeleton of a Stein manifold determine the Stein structure? - To what extent the study of Stein structures can be reduced to a combinatorial study of the skeleton? - How are the symplectic invariants of Stein manifolds, respectively the contact invariants of their boundary, determined by the skeleton? For the topological part, we will use as a source of inspiration the theory of spines and shadows of 3- and 4- manifolds. One of the goals of this research project is to adapt it to the setup of Stein manifolds and develop a calculus of Lagrangian shadows. Concerning invariants of contact manifolds, we aim to interpret symplectic homology of Stein manifolds and contact homology of their boundaries in topological terms, with the skeleton playing a central role. Further ramifications of this research project include the development of string topology on singular (stratified) spaces and the symplectic study of singularities.

1 053 101 €

Start date: 2010-09-01, End date: 2016-08-31

The proteins from thermophilic organisms are the objects of the present study. Here it is specifically proposed a study on the microscopic origin of proteins thermostability using a multi-computational approach. The multi-methodological strategy is a powerful tool for exploring this issue since it allows an investigation at many different levels of molecular details. Neutron Scattering experiments will complement the in silico investigation. The present study will tackle the issue of thermostability under a new light by explicitly focusing on the role of hydration water and by carefully selecting homologues proteins from mesophilic, thermophilic and hyperthermophilic organisms as cases of study. I will investigate how the chemical composition of a protein surface, the distribution of charged, polar and hydrophobic amino acids, could be tuned in order to increase/reduce thermal resistance of the hydration layer and of the protein matrix. I will examine whether thermostability correlates to the flexibility or the rigidity of the protein matrix and/or of its hydration skin. I will study in details how the catalytic activity of enzymes is affected by the dynamics of the protein at extreme temperatures. The theoretical study will be supported by Neutron Scattering experiments gaining key knowledge on the structure and dynamics of hydration water and on the dynamics of proteins in the nanosecond time scale. Nowadays the possibility to design functional thermostable proteins is strategic for expanding the use of enzymes in industrial processes and in biotechnology. The study of the coupling between hydration water and protein surface could pave the way for the computer-aided engineering of thermostable proteins.

1 225 000 €

Start date: 2011-05-01, End date: 2016-04-30