A neurocognitive mechanism for increased cooperation during group formation.

How do group size changes influence cooperation within groups? To examine this question, we performed a dynamic, network-based prisoner's dilemma experiment with fMRI. Across 83 human participants, we observed increased cooperation as group size increased. However, our computational modeling analysis of behavior and fMRI revealed that groups size itself did not increase cooperation.

Representations of the intrinsic value of information in mouse orbitofrontal cortex.

Animals are motivated to seek information that does not influence reward outcomes, suggesting that information has intrinsic value. We have developed an odor-based information seeking task that reveals that mice choose to receive information even though it does not alter the reward outcome. Moreover, mice are willing to pay for information by sacrificing water reward, suggesting that information is of intrinsic value to a mouse.

Trust in Institutions, Not in Political Leaders, Determines Compliance in COVID-19 Prevention Measures within Societies across the Globe.

A core assumption often heard in public health discourse is that increasing trust in national political leaders is essential for securing public health compliance during crises such as the COVID-19 pandemic (2019-ongoing). However, studies of national government trust are typically too coarse-grained to differentiate between trust in institutions versus more interpersonal trust in political leaders. Here, we present multiscale trust measurements for twelve countries and territories across the West, Oceania and East Asia.

Dextran-coated iron oxide nanoparticle-induced nanotoxicity in neuron cultures.

Recent technological advances have introduced diverse engineered nanoparticles (ENPs) into our air, water, medicine, cosmetics, clothing, and food. However, the health and environmental effects of these increasingly common ENPs are still not well understood. In particular, potential neurological effects are one of the most poorly understood areas of nanoparticle toxicology (nanotoxicology), in that low-to-moderate neurotoxicity can be subtle and difficult to measure.

Multiscale Computation and Dynamic Attention in Biological and Artificial Intelligence.

Biological and artificial intelligence (AI) are often defined by their capacity to achieve a hierarchy of short-term and long-term goals that require incorporating information over time and space at both local and global scales. More advanced forms of this capacity involve the adaptive modulation of integration across scales, which resolve computational inefficiency and explore-exploit dilemmas at the same time. Research in neuroscience and AI have both made progress towards understanding architectures that achieve this.

Towards biological applications of nanophotonic tweezers.

Optical trapping (synonymous with optical tweezers) has become a core biophysical technique widely used for interrogating fundamental biological processes on size scales ranging from the single-molecule to the cellular level. Recent advances in nanotechnology have led to the development of 'nanophotonic tweezers,' an exciting new class of 'on-chip' optical traps. Here, we describe how nanophotonic tweezers are making optical trap technology more broadly accessible and bringing unique biosensing and manipulation capabilities to biological applications of optical trapping.

Synergistic Coordination of Chromatin Torsional Mechanics and Topoisomerase Activity.

DNA replication in eukaryotes generates DNA supercoiling, which may intertwine (braid) daughter chromatin fibers to form precatenanes, posing topological challenges during chromosome segregation. The mechanisms that limit precatenane formation remain unclear. By making direct torque measurements, we demonstrate that the intrinsic mechanical properties of chromatin play a fundamental role in dictating precatenane formation and regulating chromatin topology.

High Trap Stiffness Microcylinders for Nanophotonic Trapping.

Nanophotonic waveguides have enabled on-chip optical trap arrays for high-throughput manipulation and measurements. However, the realization of the full potential of these devices requires trapping enhancement for applications that need large trapping force. Here, we demonstrate a solution via fabrication of high refractive index cylindrical trapping particles.

Nanophotonic trapping: precise manipulation and measurement of biomolecular arrays.

Optical trapping is a powerful and widely used laboratory technique in the biological and materials sciences that enables rapid manipulation and measurement at the nanometer scale. However, expanding the analytical throughput of this technique beyond the serial capabilities of established single-trap microscope-based optical tweezers remains a current goal in the field. In recent years, advances in nanotechnology have been leveraged to create innovative optical trapping methods that increase the number of available optical traps and permit parallel manipulation and measurement of arrays of optically trapped targets.

Biocompatible and High Stiffness Nanophotonic Trap Array for Precise and Versatile Manipulation.

The advent of nanophotonic evanescent field trapping and transport platforms has permitted increasingly complex single molecule and single cell studies on-chip. Here, we present the next generation of nanophotonic Standing Wave Array Traps (nSWATs) representing a streamlined CMOS fabrication process and compact biocompatible design. These devices utilize silicon nitride (SiN) waveguides, operate with a biofriendly 1064 nm laser, allow for several watts of input power with minimal absorption and heating, and are protected by an anticorrosive layer for sustained on-chip microelectronics in aqueous salt buffers.