Talks

As endpoints of massive stellar evolution, showcases for the densest matter in the universe, and sites for heavy element nucleosynthesis, neutron star mergers are superb laboratories for astrophysics, strong gravity and nuclear physics. Gravitational-wave observations of these mergers are beginning to reveal neutron stars’ internal structure, provide insight into the astrophysical processes that form them, and expose their role in the chemical evolution of the Galaxy. I will survey some of my recent work in these areas and describe how our theoretical understanding of neutron stars is being shaped by gravitational-wave discoveries.

In quantum field theory (QFT) the spin-statistics theorem says that in a unitary QFT, a particle has half-integer spin if and only if it is a fermion. I show how to phrase this statement in the language of functorial field theories. More precisely, I explain when a functorial field theory "has fermions" and "has spinors" and when they are "related". I will then restrict to topological field theories (TFTs) and define unitary TFTs. There are counterexamples of the spin-statistics theorem for non-unitary TFTs. I will prove that every unitary TFT satisfies the spin-statistics theorem.

Alterations in nuclear and chromatin organization are hallmarks of cellular aging and many aging related diseases including cancer and neurodegeneration. However, quantitative methods to analyse subtle alterations in chromatin states to understand cell-state transitions and for early disease diagnostics are still missing. In this talk, I will first describe our AI-based chromatin imaging biomarker platform. I will then demonstrate the sensitivity of this platform to trace tumour progression and neurodegeneration using tissue biopsies. Furthermore, I will describe our ongoing clinical trials, using AI-based chromatin biomarkers in blood biopsies, for early disease diagnostics and for tracing the efficacy of therapeutic interventions in personalized and precision medicine. Finally, I will introduce a major global public health project that we have initiated to develop a chromatin imaging atlas of human blood cells in health and disease.

It is well established that chromosome territories are non-randomly organized in the interphase nucleus, with gene poor chromosome territories proximal to the nuclear periphery, while gene rich chromosome territories are closer to the nuclear center. Such an organization is conserved in evolution. We showed that the depletion of the nuclear envelope proteins i.e, lamins, not only induces chromosomal instability but also destabilizes chromosome positioning in otherwise diploid colorectal cancer cells. Remarkably, the combined loss of lamins and Emerin perturb chromosome territory and gene loci dynamics in the interphase nucleus. Furthermore, nuclear envelope proteins are essential for relaying mechanical signals into the nucleus, since cells cultured on softer substrates showed a striking change in the spatial organization of chromosome territories in an Emerin-Lamin dependent manner. Taken together, our studies reveal an overarching role for nuclear envelope proteins, in the maintenanc...