ERC FUNDED PROJECTS

The overall goal of 14Constraint is to enhance the availability and use of radiocarbon data as constraints for process-based understanding of the age distribution of carbon in and respired by soils and ecosystems. Carbon enters ecosystems by a single process, photosynthesis. It returns by a range of processes that depend on plant allocation and turnover, the efficiency and rate of litter decomposition and the mechanisms stabilizing C in soils. Thus the age distribution of respired CO2 and the age of C residing in plants, litter and soils are diagnostic properties of ecosystems that provide key constraints for testing carbon cycle models. Radiocarbon, especially the transit of ‘bomb’ 14C created in the 1960s, is a powerful tool for tracing C exchange on decadal to centennial timescales. 14Constraint will assemble a global database of existing radiocarbon data (WP1) and demonstrate how they can constrain and test ecosystem carbon cycle models. WP2 will fill data gaps and add new data from sites in key biomes that have ancillary data sufficient to construct belowground C and 14C budgets. These detailed investigations will focus on the role of time lags caused in necromass and fine roots, as well as the dynamics of deep soil C. Spatial extrapolation beyond the WP2 sites will require sampling along global gradients designed to explore the relative roles of mineralogy, vegetation and climate on the age of C in and respired from soil (WP3). Products of this 14Constraint will include the first publicly available global synthesis of terrestrial 14C data, and will add over 5000 new measurements. This project is urgently needed before atmospheric 14C levels decline to below 1950 levels as expected in the next decade.

2 283 747 €

Start date: 2016-12-01, End date: 2021-11-30

The proposed project aims at investigating the molecular mechanisms that activate B cell antigen receptor (BCR) signalling in chronic lymphocytic leukaemia (CLL). While it is widely accepted that the unbroken BCR expression in CLL cells is indicative for a key role in disease development, the mechanisms that induce BCR activation and survival of malignant cells are still elusive. Using a unique reconstitution system, we have recently shown that CLL-derived BCRs possess the exceptional capacity for cell-autonomous signalling independent of external antigen. Crystallographic analyses confirmed our model that CLL-BCRs bind to intrinsic motifs in nearby BCRs on the very same cell. In addition to the BCR, several pathogenic factors influence the biological behaviour of CLL cells, but the functional hierarchy and the effect on BCR signalling are insufficiently understood. Here, we aim at investigating the structural cause of autonomous signalling as well as the characterization of important signalling pathways and their mechanistic action in CLL pathogenesis. By combining crystallography with the measurement of autonomous signalling of wild type and mutated receptors in our unique reconstitution system, we will generate a structure-function relationship for CLL-BCRs. By generating new animal models and by employing classical as well as cutting-edge approaches of biochemistry and molecular/cellular immunology, we will comprehensively characterize the signalling pathways that are activated by autonomous signalling and might be important for CLL pathogenesis. These systematic efforts are necessary to understand how various biological mechanisms operate and ultimately activate downstream pathways that result in a lymphoproliferative disease. In addition, a cohesive model of CLL pathogenesis, which elucidates the hierarchical order of pathogenic factors and their interaction with BCR signalling, may well lead to novel disease-specific preventive or therapeutic intervention.

2 256 250 €

Start date: 2016-11-01, End date: 2021-10-31

The objective of the proposed project is to pioneer a magnetometry-based experimental framework for the detection of time-varying signatures of the ‘dark sector’. This novel approach will enable systematic searches for particles contributing to the dark matter and for dark-energy components. The nature of dark matter and that of dark energy are among the central open problems in modern physics. There are only few experimental bounds and so far no conclusive observations of dark-sector particles or fields. Experiments enabling a direct coupling to the dark sector and thus a systematic search for and study of the contributing particles and fields would open up new vistas for areas ranging from particle physics to astrophysics and cosmology, and would in particular provide insights into the physics beyond the Standard Model. Here, we propose a framework for such experimental searches based on high-precision magnetometers, and networks thereof. Our approach is distinct from existing efforts in two ways. First, it will enable searches for so-far unexplored couplings to ultra-light bosonic particles present in the Universe that could be components of dark matter and/or dark energy, in particular axions and axion-like particles (ALPs). Second, we will develop and use devices and methods tailored to search for oscillating and transient, rather than time-independent, effects. Specifically, we will use nuclear magnetic resonance (NMR) techniques for detecting spin precession caused by background axion and ALP dark matter, and geographically separated magnetometers for identify transient effects, such as crossing domain walls of ALP fields, which have been proposed as a possible dark-energy component. The devices and methods developed in the framework of this project will provide the essential components for unique searches for a broad class of dark-matter and dark-energy candidates and might enable the key experiments to understanding the dark sector.

2 474 875 €

Start date: 2016-08-01, End date: 2021-07-31

Where in the universe are heavy elements synthesized? How are these elements produced? These are two exciting and interdisciplinary questions in nuclear astrophysics today and will be investigated in my ERC project EUROPIUM. The favored astrophysical sites are neutrino-driven winds following core-collapse supernovae and neutron star mergers, where extreme conditions enable the rapid neutron capture process (r-process). We will perform long-time multidimensional simulations of these two scenarios and combine them with nucleosynthesis calculations. In neutron star mergers, the radioactive decay of neutron-rich nuclei triggers an electromagnetic signal known as kilonova. This was potentially observed in 2013 after a short gamma ray burst, associated with a neutron star merger. We will simulate the neutrino- and viscous-driven ejecta from the disk that forms after the merger around the central compact object. In addition, we will investigate supernova neutrino-driven winds that produce lighter heavy elements from strontium to silver. We will explore the impact of rotation, improved microphysics, and magnetic fields on the wind evolution and nucleosynthesis. Because the synthesis of lighter heavy elements elements occurs closer to stability, the nuclear physics uncertainties will be reduced by experiments in the near future. This will uniquely allow us to combine observations and nucleosynthesis calculations to constrain the astrophysical conditions and gain new insights into core-collapse supernovae. In nuclear physics, a new era for extreme neutron-rich isotopes is starting with new experimental facilities. Based on our simulations, we will study the impact of the nuclear physics input (nuclear masses, beta decays, neutron captures, and fission) going beyond the state-of-the-art by providing r-process abundances with uncertainties. Comparing our results with forefront observations of the oldest stars will in turn provide new insights about the origin of heavy elements.

1 446 875 €

Start date: 2016-05-01, End date: 2021-04-30