ERC FUNDED PROJECTS

A critical question in Earth system science is what was the impact of prehistoric people on the biosphere and climate? There is much information about human impact through clearance, agriculture, erosion, and modifying water and nutrient budgets. Humans have greatly changed the Earth in the last 8000 years, but did humans modify the major ecological processes (e.g. assembly rules) that shape community assembly and dynamics? Did inter-relationships between processes change in response to human impact? Lyons et al. & Dietl (2016 Nature) suggest that human activities in the last 6000 years had such impacts. Dietl proposes that using past ‘natural experiments’ to predict future changes is “flawed” and “out is the use of uniformitarianism”. As using natural experiments is a common strategy and uniformitarianism is the major working concept in Earth sciences, it is imperative to test whether prehistoric human activity changed major ecological processes determining community development. To test this hypothesis, patterns in pollen-stratigraphical data for the past 11,500 years from over 2000 sites across the globe will be explored consistently using numerical techniques to discern changes in 25 ecosystem properties (richness, evenness, and diversity; turnover; rates of change; taxon co-occurrences, etc.). Patterns in these properties will be compared statistically at sites within biomes, between biomes, within continents, and between continents to test the hypotheses that prehistoric human activities changed the basic ecological processes of community assembly and that their inter-relationships changed through time. These areas provide major contrasts in human prehistory and biomes. HOPE is interdisciplinary: pollen analysis, databases, multivariate analysis, ecology, new statistical methods, numerical simulations, statistical modelling. HOPE’s impact goes beyond human effects on the biosphere and extends to the very core of Earth science’s basic conceptual framework.

2 278 884 €

Start date: 2018-01-01, End date: 2022-12-31

In a truly cross-disciplinary research project encompassing surface science, astrophysics and chemistry we aim to address two of the major outstanding questions in the field of astrochemistry, namely i) how molecular hydrogen, the most abundant molecule in the interstellar medium, form, and ii) whether it is possible to identify specific Polycyclic Aromatic Hydrocarbon (PAH) species in interstellar spectra. The insights gained from the experimental investigations may revolutionize our current understanding of astrochemistry and will have impact even beyond the field. Special emphasis will be placed on the impact our findings will have on ascertaining the suitability of PAHs as a hydrogen storage medium. By combining scanning tunneling microscopy, thermal desorption spectroscopy, laser-induced thermal desorption time-of-flight mass spectrometry, fluorescence spectroscopy experiments and density functional theory calculations we will map out the interaction of atomic hydrogen with PAHs. The goal of the investigation is to obtain atomic level understanding of the atomic hydrogen – PAH interaction in order to i) ascertain whether interstellar molecular hydrogen formation, contrary to present belief but in accordance with our recent calculations, could occur predominantly via interaction with PAHs, ii) measure the adsorption/emission spectrum of Hydrogen-PAH complexes and thereby facilitate observational detection of these complexes in the interstellar medium, iii) determine whether PAHs are a promising medium for hydrogen storage and iv) ascertain whether the hydrogen storage properties of PAHs are tunable by electro-magnetic radiation. This ambitious and cross-disciplinary research project will predominantly take place at the newly established Surface Dynamics Laboratory at the University of Aarhus, headed by the applicant, but will also benefit from fruitful collaborations already initiated with local, national and international colleagues.

1 499 810 €

Start date: 2008-07-01, End date: 2013-06-30

Molecular biology strives for the prediction of function, based on the genetic code. Within neuroscience, this is reflected in the intense study of the molecular basis for ligand recognition by neurotransmitter receptors. Consequently, structural and functional studies have rendered a profoundly high-resolution view of ionotropic glutamate receptors (iGluRs), the archetypal excitatory receptor in the brain. But even this view is obsolete: we don’t know why some receptors recognize glutamate yet others recognize other ligands; and we have been unable to functionally test the underlying chemical interactions. In other words, our view differs substantially from nature’s own view of ligand recognition. I plan to lead a workgroup attacking this problem on three fronts. First, bioinformatic identification and electrophysiological characterization of a broad and representative sample of iGluRs from across the spectrum of life will unveil the diversity of ligand recognition in iGluRs. Second, phylogenetic analyses combined with functional experiments will reveal the molecular changes that nature employed in arriving at existing means of ligand recognition in iGluRs. Finally, chemical-scale mutagenesis will be employed to overcome previous technical limitations and dissect the precise chemical interactions that determine the specific recognition of certain ligands. With my experience in combining phylogenetics and functional experiments and in the use of chemical-scale mutagenesis, the objectives are within reach. Together, they form a unique approach that will expose nature’s own view of ligand recognition in iGluRs, revealing the molecular blueprint for protein function in the nervous system.

1 500 000 €

Start date: 2019-03-01, End date: 2024-02-29

State-of-the-art simulations and observations highlight the self-organization of convective clouds. Our recent work shows two aspects: these clouds are capable of unexpected increase in extreme precipitation when temperature rises; interactions between clouds produce the extremes. As clouds interact, they organize in space and carry a memory of past interaction and precipitation events. This evidence reveals a severe shortcoming of the conventional separation into "forcing" and "feedback" in climate model parameterizations, namely that the "feedback" develops a dynamics of its own, thus driving the extremes. The major scientific challenge tackled in INTERACTION is to make a ground-breaking departure from the established paradigm of "quasi-equilibrium" and instantaneous convective adjustment, traditionally used for parameterization of "sub-grid-scale processes" in general circulation models. To capture convective self-organization and extremes, the out-of-equilibrium cloud field must be described. In INTERACTION, I will produce a conceptual model for the out-of-equilibrium system of interacting clouds. Once triggered, clouds precipitate on a short timescale, but then relax in a "recovery" state where further precipitation is suppressed. Interaction with the surroundings occurs through cold pool outflow,facilitating the onset of new events in the wake. I will perform tailored numerical experiments using cutting-edge large-eddy simulations and very-high-resolution observational analysis to determine the effective interactions in the cloud system. Going beyond traditional forcing-and-feedback descriptions, I emphasize gradual self-organization with explicit temperature dependence. The list of key variables of atmospheric water vapor, temperature and precipitation must therefore be amended by variables describing organization. Capturing the self-organization of convection is essential for understanding of the risk of precipitation extremes today and in a future climate.

1 314 800 €

Start date: 2018-07-01, End date: 2023-06-30