ERC FUNDED PROJECTS

Attosecond light pulses are generated when an intense laser interacts with a gas target. These pulses are not only short, enabling the study of electronic processes at their natural time scale, but also coherent. The vision of this proposal is to extend temporal coherent control concepts to a completely new regime of time and energy, combining (i) ultrashort pulses (ii) broadband excitation (iii) high photon energy, allowing scientists to reach not only valence but also inner shells in atoms and molecules, and, when needed, (iv) high spatial resolution. We want to explore how elementary electronic processes in atoms, molecules and more complex systems can be controlled by using well designed sequences of attosecond pulses. The research project proposed is organized into four parts: 1. Attosecond control of light leading to controlled sequences of attosecond pulses We will develop techniques to generate sequences of attosecond pulses with a variable number of pulses and controlled carrier-envelope-phase variation between consecutive pulses. 2. Attosecond control of electronic processes in atoms and molecules We will investigate the dynamics and coherence of phenomena induced by attosecond excitation of electron wave packets in various systems and we will explore how they can be controlled by a controlled sequence of ultrashort pulses. 3. Intense attosecond sources to reach the nonlinear regime We will optimize attosecond light sources in a systematic way, including amplification of the radiation by injecting a free electron laser. This will open up the possibility to develop nonlinear measurement and control schemes. 4. Attosecond control in more complex systems, including high spatial resolution We will develop ultrafast microscopy techniques, in order to obtain meaningful temporal information in surface and solid state physics. Two directions will be explored, digital in line microscopic holography and photoemission electron microscopy.

2 250 000 €

Start date: 2008-12-01, End date: 2013-11-30

This proposal targets the emerging frontier research field of multiple-input multiple-output (MIMO) systems along with several innovative and somewhat unconventional applications of such systems. The use of arrays of transmitters and receivers will have a profound impact on future medical imaging/therapy systems, radar systems, and radio communication networks. Multiple transmitters provide a tremendous versatility and allow waveforms to be adapted temporally and spatially to environmental conditions. This is useful for individually tailored illumination of human tissue in biomedical imaging or ultrasound therapy. In radar systems, multiple transmit beams can be formed simultaneously via separate waveform designs allowing accurate target classification. In a wireless communication system, multiple communication signals can be directed to one or more users at the same time on the same frequency carrier. In addition, multiple receivers can be used in the above applications to provide increased detection performance, interference rejection, and improved estimation accuracy. The joint modelling, analysis, and design of these multidimensional transmit and receive schemes form the core of this research proposal. Ultimately, our research aims at developing the fundamental tools that will allow the design of wireless communication systems with an order-of-magnitude higher capacity at a lower cost than today; of ultrasound therapy systems maximizing delivered power while reducing treatment duration and unwanted illumination; and of distributed aperture multi-beam radars allowing more effective target location, identification, and classification. Europe has several successful industries that are active in biomedical imaging/therapy, radar systems, and wireless communications. The future success of these sectors critically depends on the ability to innovate and integrate new technology.

1 872 720 €

Start date: 2009-01-01, End date: 2013-12-31

Despite improved therapy, cardiovascular diseases remain the most prevalent diseases in the European Union and the incidence is rising due to increased obesity and ageing. The fine-tuned regulation of vascular functions is essential not only for preventing atherosclerotic diseases, but also after tissue injury, where the coordinated growth and maturation of new blood vessels provides oxygen and nutrient supply. On the other hand, excessive vessel growth or the generation of immature, leaky vessels contributes to pathological angiogenesis. Thus, the regulation of the complex processes governing vessel growth and maturation has broad impacts for several diseases ranging from tumor angiogenesis, diabetic retinopathy, to ischemic cardiovascular diseases. MicroRNAs (miRs) are small noncoding RNAs, which play a crucial role in embryonic development and tissue homeostasis. However, only limited information is available regarding the role of miRs in the vasculature. MiRs regulate gene expression by binding to the target mRNA leading either to degradation or to translational repression. Because miRs control patterns of target genes, miRs represent an attractive and promising therapeutic target to interfere with complex processes such as neovascularization and repair of ischemic tissues. Therefore, the present application aims to identify miRs in the vasculature, which regulate vessel growth and vessel remodelling and may, thus, serve as therapeutic targets in ischemic diseases. Since ageing critically impairs endothelial function, neovascularization and vascular repair, we will specifically identify miRs, which are dysregulated during ageing in endothelial cells and pro-angiogenic progenitor cells, in order to develop novel strategies to rescue age-induced impairment of neovascularization. Beyond the specific scope of the present application, the principle findings may have impact for other diseases, where deregulated vessel growth causes or accelerates disease states.

2 375 394 €

Start date: 2009-03-01, End date: 2014-02-28

Magnetic fields in stars, planets, accretion discs, and galaxies are believed to be the result of a dynamo process converting kinetic energy into magnetic energy. This work focuses on the solar dynamo, but dynamos in other astrophysical systems will also be addressed. In particular, direct high-resolution three-dimensional simulations are used to understand particular aspects of the solar dynamo and ultimately to simulate the solar dynamo as a whole. Phenomenological approaches will be avoided in favor of obtaining rigorous results. A major problem is catastrophic quenching, i.e. the decline of dynamo effects in inverse proportion to the magnetic Reynolds number, which is huge. Tremendous advances have been made in the last few years since the cause of catastrophic quenching in dynamos has been understood in terms of magnetic helicity evolution. The numerical tools are now in place to allow for magnetic helicity fluxes via coronal mass ejections, thus alleviating catastrophic quenching. This work employs simulations in spherical shells, augmented by Cartesian simulations in special cases. The roles of the near-surface shear layer, the tachocline, as well as pumping in the bulk of the convection zone are to be clarified. The Pencil Code will be used for most applications. The code is third order in time and sixth order in space and is used for solving the hydromagnetic equations. It is a public domain code developed by roughly 20 scientists world wide and maintained under an a central versioning system at Nordita. Automatic nightly tests of currently 30 applications ensure the integrity of the code. It is used for a wide range of applications and may include the effects of radiation, self-gravity, dust, chemistry, variable ionization, cosmic rays, in addition to those of magnetohydrodynamics. The code with its infrastructure offers a good opportunity for individuals within a broad group of people to develop new tools that may automatically be useful to others.

2 220 000 €

Start date: 2009-02-01, End date: 2014-01-31