ERC FUNDED PROJECTS

The project aims at introducing a paradigm shift in the development of nonlinear photonics with atomically-engineered two-dimensional (2D) van der Waals superlattices (2DSs). Monolayer 2D materials have large optical nonlinear susceptibilities, a few orders of magnitude larger than typical traditional bulk materials. However, nonlinear frequency conversion efficiency of monolayer 2D materials is typically weak mainly due to their extremely short interaction length (~atomic scale) and relatively large absorption coefficient (e.g.,>5×10^7 m^-1 in the visible range for graphene and MoS2 after thickness normalization). In this context, I will construct atomically-engineered heterojunctions based 2DSs to significantly enhance the nonlinear optical responses of 2D materials by coherently increasing light-matter interaction length and efficiently creating fundamentally new physical properties (e.g., reducing optical loss and increasing nonlinear susceptibilities). The concrete project objectives are to theoretically calculate, experimentally fabricate and study optical nonlinearities of 2DSs for next-generation nonlinear photonics at the nanoscale. More specifically, I will use 2DSs as new building blocks to develop three of the most disruptive nonlinear photonic devices: (1) on-chip optical parametric generation sources; (2) broadband Terahertz sources; (3) high-purity photon-pair emitters. These devices will lead to a breakthrough technology to enable highly-integrated, high-efficient and wideband lab-on-chip photonic systems with unprecedented performance in system size, power consumption, flexibility and reliability, ideally fitting numerous growing and emerging applications, e.g. metrology, portable sensing/imaging, and quantum-communications. Based on my proven track record and my pioneering work on 2D materials based photonics and optoelectronics, I believe I will accomplish this ambitious frontier research program with a strong interdisciplinary nature.

2 442 448 €

Start date: 2019-09-01, End date: 2024-08-31

By detailed evolutionary comparisons among multiple sequenced yeast genomes, we have identified several unusual regions where our preliminary evidence suggests that previously unknown molecular biology phenomena, involving rearrangement of genomic DNA, are occurring. I now propose to use a combination of dry-lab and wet-lab experimental approaches to characterize these regions and phenomena further. One region is a 24-kb section of chromosome XIV that appears to undergo recurrent 'flip/flop' inversion between two isomers at a fairly high rate in five species as diverse as Saccharomyces cerevisiae and Naumovia castellii, leading to a 1:1 ratio of the two isomers in each species. We hypothesize that this region is the site of a programmed DNA rearrangement analogous to mating-type switching. We have also identified two new genes related to the mating-type switching endonuclease HO, but different from it, that are potentially involved in rearrangement processes though not necessarily the inversion described above. We will determine the sites of action of these endonucleases. Separately, we have found evidence for a process of recurrent deletion of DNA from regions flanking the mating-type (MAT) locus in all yeast species that are descended from the whole-genome duplication (WGD) event, causing continual transpositions of genes from beside MAT to other locations in the genome. In related computational work, we propose to investigate an hypothesis that evolutionary loss of the MATa2 transcriptional activator may have been the cause of the WGD event.

1 516 960 €

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

The genetic code was established at a very early stage during the evolution of life on Earth and is nearly universal. In eukaryotic nuclear genes, the only known examples of a sense codon that underwent an evolutionary change of meaning, from one amino acid to another, occur in yeast species. The codon CUG is translated as Leu in the universal genetic code, but it has long been known to be translated as Ser in some Candida species. In recent work, we discovered that this switch is one of three parallel reassignments of CUG that occurred in three closely related clades of yeasts. CUG was reassigned once from Leu to Ala, and twice from Leu to Ser, in three separate events. The meaning of sense codons in the nuclear genetic code has otherwise remained completely stable during all of eukaryotic evolution, so why was CUG so unstable in yeasts? CODEKILLER will test a radical new hypothesis that the genetic code changes were caused by a killer toxin that specifically attacked the tRNA that translated CUG as Leu. The hypothesis implies that the reassignments of CUG were not driven by selection in favor of their effects on the proteome, as commonly assumed, but by selection against the existence of a particular tRNA. As well as searching for this killer toxin, we will study the detailed mechanism of genetic code change by engineering a reversal of a CUG-Ser species back to CUG-Leu translation, and investigate translation in some species that naturally contain both tRNA-Leu and tRNA-Ser molecules capable of decoding CUG.

2 368 356 €

Start date: 2018-10-01, End date: 2023-09-30

The Mediterranean, a key socio-cultural, economic and political crossroads, has shifted its relative position recently, with profound effects for relations between the peoples associated with its diverse parts. Crosslocations is a groundbreaking theoretical approach that goes beyond current borders research to analyse the significance of the changes in relations between places and peoples that this involves. It does this through explaining shifts in the relative positioning of the Mediterranean’s many locations – i.e. the changing values of where people are rather than who they are. Approaches focusing on people’s identities, statecraft or networks do not provide a way to research how the relative value of ‘being somewhere in particular’ is changing and diversifying. The approach builds on the idea that in socio-cultural terms, location is a form of political, social, economic, and technical relative positioning, involving diverse scales that calibrate relative values (here called ‘locating regimes’). This means locations are both multiple and historically variable, so different types of location may overlap in the same geographical space, particularly in crossroads regions such as the Mediterranean. The dynamics between them alter relations between places, significantly affecting people’s daily lives, including their life chances, wellbeing, environmental, social and political conditions and status. The project will first research the locating regimes crossing the Mediterranean region (border regimes, infrastructures; digital technologies; fiscal, financial and trading systems; environmental policies; and social and religious structures); then intensively ethnographically study the socio-cultural dynamics of relative positioning that these regimes generate in selected parts of the Mediterranean region. Through explaining the dynamics of relative location, Crosslocations will transform our understanding of trans-local, socio-cultural relations and separations.

2 433 234 €

Start date: 2016-09-01, End date: 2021-08-31