Design principles for energy transfer in the photosystem II supercomplex from kinetic transition networks.

Photosystem II (PSII) has the unique ability to perform water-splitting. With light-harvesting complexes, it forms the PSII supercomplex (PSII-SC) which is a functional unit that can perform efficient energy conversion, as well as photoprotection, allowing photosynthetic organisms to adapt to the naturally fluctuating sunlight intensity. Achieving these functions requires a collaborative energy transfer network between all subunits of the PSII-SC.

Rapid physiological integration of fused ctenophores.

The mechanisms by which organisms recognize the 'self' from the 'non-self' remain poorly understood. Moreover, the capability of transplanted tissue to functionally integrate is unclear in many organisms. Here, we report that two injured Mnemiopsis leidyi individuals, a species of planktonic animals known as comb jellies or ctenophores, are capable of rapidly fusing into a single entity in which some physiological functions are integrated.

Chlorophyll to zeaxanthin energy transfer in nonphotochemical quenching: An exciton annihilation-free transient absorption study.

Zeaxanthin (Zea) is a key component in the energy-dependent, rapidly reversible, nonphotochemical quenching process (qE) that regulates photosynthetic light harvesting. Previous transient absorption (TA) studies suggested that Zea can participate in direct quenching via chlorophyll (Chl) to Zea energy transfer. However, the contamination of intrinsic exciton-exciton annihilation (EEA) makes the assignment of TA signal ambiguous.

High-throughput protein characterization by complementation using DNA barcoded fragment libraries.

Our ability to predict, control, or design biological function is fundamentally limited by poorly annotated gene function. This can be particularly challenging in non-model systems. Accordingly, there is motivation for new high-throughput methods for accurate functional annotation.

A tradeoff between efficiency and robustness in the hippocampal-neocortical memory network during human and rodent sleep.

Sleep constitutes a brain state of disengagement from the external world that supports memory consolidation and restores cognitive resources. The precise mechanisms how sleep and its varied stages support information processing remain largely unknown. Synaptic scaling models imply that daytime learning accumulates neural information, which is then consolidated and downregulated during sleep.

Methane to bioproducts: unraveling the potential of methanotrophs for biomanufacturing.

With the continuous increase in the world population, anthropogenic activities will generate more waste and create greenhouse gases such as methane, amplifying global warming. The biological conversion of methane into biochemicals is a sustainable solution to sequester and convert this greenhouse gas. Methanotrophic bacteria fulfill this role by utilizing methane as a feedstock while manufacturing various bioproducts.

Flexible Soft X-Ray Image Sensors based on Metal Halide Perovskites With High Quantum Efficiency.

Soft X-ray imaging is a powerful tool to explore the structure of cells, probe material with nanometer resolution, and investigate the energetic phenomena in the universe. Conventional soft X-ray image sensors are by and large Si-based charge coupled devices that suffer from low frame rates, complex fabrication processes, mechanical inflexibility, and required cooling below -60 °C. Here, a soft X-ray photodiode is reported based on low-cost metal halide perovskite with comparable performance to commercial Si-based device.

Understanding admixture fractions: theory and estimation of gene-flow.

Estimation of admixture proportions has become one of the most commonly used computational tools in population genomics. However, there is remarkably little population genetic theory on statistical properties of these variables. We develop theoretical results that can accurately predict means and variances of admixture proportions within a population using models with recombination and genetic drift.

Updimensioning strategy derived from synthetic equiaxed grain structures for approximating 3D grain size distributions from 2D visualizations with 1D parameters.

We generated synthetic equiaxed grain structures using computer graphics software to explore the relationship between various grain size determination methods and true three-dimensional (3D) grain diameters. Mirroring grain measurement techniques, the synthetic 3D grain structures are imaged as 2D micrographs which are measured to yield 1D grain size parameters. Synthetic grain structures provide data at a mass scale and permit exploration of both polished and fractured surface micrographs, revealing one-to-one correspondence between exposed 2D grain cross-sections and individual 3D grains.

Radiation image reconstruction and uncertainty quantification using a Gaussian process prior.

We propose a complete framework for Bayesian image reconstruction and uncertainty quantification based on a Gaussian process prior (GPP) to overcome limitations of maximum likelihood expectation maximization (ML-EM) image reconstruction algorithm. The prior distribution is constructed with a zero-mean Gaussian process (GP) with a choice of a covariance function, and a link function is used to map the Gaussian process to an image. Unlike many other maximum a posteriori approaches, our method offers highly interpretable hyperparamters that are selected automatically with the empirical Bayes method.

Copper complexation of rosarin: formation of bis-copper rosarin and mono-copper linear tridipyrrin complexes.

A novel rosarin di-Cu complex 2Cu-1 and a linear six-pyrrolic mono-copper complex 1Cu-1 were synthesized using rosarin as the ligand. The molecular conformations of these complexes were confirmed by X-ray crystallography. The optical study of 1Cu-1 indicated NIR-II absorption due to the long six-pyrrolic ligand and the ICT effect.

Improved Sensitivity in a Modified Berkeley Red Sensor of Transmembrane Potential.

Voltage imaging is an important complement to traditional methods for probing cellular physiology, such as electrode-based patch clamp techniques. Unlike the related Ca imaging, voltage imaging provides a direct visualization of bioelectricity changes. We have been exploring the use of sulfonated silicon rhodamine dyes (Berkeley Red Sensor of Transmembrane potential, BeRST) for voltage imaging.

Metabolic interactions shape emergent biofilm structures in a conceptual model of gut mucosal bacterial communities.

The gut microbiome plays a major role in human health; however, little is known about the structural arrangement of microbes and factors governing their distribution. In this work, we present an in silico agent-based model (ABM) to conceptually simulate the dynamics of gut mucosal bacterial communities. We explored how various types of metabolic interactions, including competition, neutralism, commensalism, and mutualism, affect community structure, through nutrient consumption and metabolite exchange.

The path ahead for understanding Toll-like receptor-driven systemic autoimmunity.

Five mammalian Toll-like receptors (TLR 3, 7, 8, 9, and 13) recognize nucleic acids (NA) and induce signals that control the function of multiple immune cell types and initiate both innate and adaptive immune responses. While these receptors enable recognition of diverse microbial threats, in some instances, they respond inappropriately to self-NA released from host cells and drive the development of autoimmune diseases. Specifically, activation of TLR7 and TLR8 by self-RNA and TLR9 by self-DNA has been linked to development of a collection of systemic autoimmune or autoinflammatory disorders, including systemic lupus erythematosus, systemic juvenile idiopathic arthritis, and macrophage activation syndrome.

Quantifying the topology of magnetic skyrmions in three dimensions.

Magnetic skyrmions have so far been treated as two-dimensional spin structures characterized by a topological winding number. However, in real systems with the finite thickness of the device material being larger than the magnetic exchange length, the skyrmion spin texture extends into the third dimension and cannot be assumed as homogeneous. Using soft x-ray laminography, we reconstruct with about 20-nanometer spatial (voxel) size the full three-dimensional spin texture of a skyrmion in an 800-nanometer-diameter and 95-nanometer-thin disk patterned into a 30× [iridium/cobalt/platinum] multilayered film.

Two-Dimensional Silver-Isocyanide Frameworks.

Metal-organic frameworks (MOFs) have been widely studied due to their versatile applications and easily tunable structures. However, heteroatom-metal coordination dominates the MOFs community, and the rational synthesis of carbon-metal coordination-based MOFs remains a significant challenge. Herein, two-dimensional (2D) MOFs based on silver-carbon linkages are synthesized through the coordination between silver(I) salt and isocyanide-based monomers at ambient condition.