Ultraviolet Superradiance from Mega-Networks of Tryptophan in Biological Architectures.

Networks of tryptophan (Trp)─an aromatic amino acid with strong fluorescence response─are ubiquitous in biological systems, forming diverse architectures in transmembrane proteins, cytoskeletal filaments, subneuronal elements, photoreceptor complexes, virion capsids, and other cellular structures. We analyze the cooperative effects induced by ultraviolet (UV) excitation of several biologically relevant Trp mega-networks, thus giving insights into novel mechanisms for cellular signaling and control. Our theoretical analysis in the single-excitation manifold predicts the formation of strongly superradiant states due to collective interactions among organized arrangements of up to >10 Trp UV-excited transition dipoles in microtubule architectures, which leads to an enhancement of the fluorescence quantum yield (QY) that is confirmed by our experiments.

Identifying Māori perspectives on gene editing in Aotearoa New Zealand.

Māori perspectives on gene technologies are evolving, and traditional cultural constructs continue to inform a wide diversity of views. Here we summarise a series of research activities aimed at identifying evolving Māori perspectives on gene editing and how these inform engagement at the co-innovation interface.

Is the North Atlantic Geodia barretti (Porifera, Tetractinellida, Geodiidae) present on the Southwest Indian Ridge?

There are currently 163 species of Geodia Lamarck, 1815 described worldwide, many of which are found in deep waters, but none of which have been recorded from the Southwest Indian Ridge (SWIR). Spicule morphology and barcodes (Folmer COI, 28S (C2D2), partial 18S) suggest that a specimen of Geodia collected on the SWIR at a depth of 2236 m is closely comparable to Geodia barretti Bowerbank, 1858. Geodia barretti is the most studied and thus well-known deep-sea Geodia species, due to its wide North Atlantic distribution and key role in boreal sponge grounds.

Second quantization of many-body dispersion interactions for chemical and biological systems.

The many-body dispersion (MBD) framework is a successful approach for modeling the long-range electronic correlation energy and optical response of systems with thousands of atoms. Inspired by field theory, here we develop a second-quantized MBD formalism (SQ-MBD) that recasts a system of atomic quantum Drude oscillators in a Fock-space representation. SQ-MBD provides: (i) tools for projecting observables (interaction energy, transition multipoles, polarizability tensors) on coarse-grained representations of the atomistic system ranging from single atoms to large structural motifs, (ii) a quantum-information framework to analyze correlations and (non)separability among fragments in a given molecular complex, and (iii) a path toward the applicability of the MBD framework to molecular complexes with even larger number of atoms.

Examining the origins of observed terahertz modes from an optically pumped atomistic model protein in aqueous solution.

The microscopic origins of terahertz (THz) vibrational modes in biological systems are an active and open area of current research. Recent experiments [Phys Rev X. , 031061 (2018)] have revealed the presence of a pronounced mode at ∼0.