National Science Foundation

Abstract Global warming results from anthropogenic greenhouse gas emissions which upset the delicate balance between the incoming sunlight, and the reflected and emitted radiation from Earth. The imbalance leads to energy accumulation in the atmosphere, oceans and land, and melting of the cryosphere, resulting in increasing temperatures, rising sea levels, and more extreme weather around the globe. Despite the fundamental role of the energy imbalance in regulating the climate system, as known to humanity for more than two centuries, our capacity to observe it is rapidly deteriorating as satellites are being decommissioned.

Science, like other sectors of society, is currently in a period of rapid social and cultural change. Demands for the decolonization and democratization of research culture and scientific data are prevalent. Systematic biology, as the research community that focuses on the existentially important issue of understanding global biodiversity, and as the standard-bearer for a field deeply rooted in colonialist approaches, has a unique opportunity to develop and model a meaningful and actionable vision for systemic change. Because systematics research requires sampling and analyzing planetary biodiversity, it operates within a global arena in which undoing exclusionary norms and practices, and reimagining a new kind of science that builds knowledge collectively, is both possible and potentially hugely impactful. Because of its history, the discipline has the potential to become a powerful model of intentional transformation. Professional systematists work and conduct research across natural history museums, academic institutions, federal agencies, national laboratories, international organizations, and the private sector and they serve as leaders throughout the disciplinary ecosystem; as a result, they are well-positioned to shape cultural transformation. We highlight just one example of a change lever (peer review of proposals) to illustrate this. Beneficial outcomes of such a new era of systematics will be extensive for continued research advances in biodiversity and phylogenetics, and for critical challenges that lie at the science-society-policy intersection.

We demonstrate theutility of block polyelectrolyte (bPE)additivesto enhance viscosity and resolve challenges with the three-dimensional(3D) printability of extrusion-based biopolymer inks. The additionof oppositely charged bPEs to solutions of photocurable gelatin methacryloyl(GelMA) results in complexation-driven self-assembly of the bPEs,leading to GelMA/bPE inks that are printable at physiological temperatures,representing stark improvements over GelMA inks that suffer from lowviscosity at 37 °C, leading to low printability and poor structuralstability. The hierarchical microstructure of the self-assemblies(either jammed micelles or 3D networks) formed by the oppositely chargedbPEs, confirmed by small-angle X-ray scattering, is attributed tothe enhancements in the shear strength and printability of the GelMA/bPEinks. Varying bPE concentration in the inks is shown to enable tunabilityof the rheological properties to meet the criteria of pre- and postextrusionflow characteristics for 3D printing, including prominent yieldingbehavior, strong shear thinning, and rapid recovery upon flow cessation.Moreover, the bPE self-assemblies also contribute to the robustnessof the photo-cross-linked hydrogels; photo-cross-linked GelMA/bPEhydrogels are shown to exhibit higher shear strength than photo-cross-linkedGelMA hydrogels. Last, the assessment of the printability of GelMA/bPEinks indicates excellent printing performance, including minimal swellingpostextrusion, satisfactory retention of the filament shape upon deposition,and satisfactory shape fidelity of the various printed constructs.We envision this study to serve as a practical guide for the printingof bespoke extrusion inks where bPEs are used as scaffolds and viscosityenhancers that can be emulated in a range of photocurable precursors.

This presentation combines the findings of two closely-related Research Experience for Undergraduates (REU) programs, one which ran from 2015-2019 and was specifically for engineering students with ADHD, and a second program, running from 2022-present, open to neurodiverse engineering students (specifically targeting ADHD, dyslexia and/or anxiety). These programs are inspired by research which links the above neurodiversities to increased creativity and innovation, as well as the ability to visualize complex systems. Both REU programs are inspired by the strengths-based approach to neurodiversity. This model builds an environment which plays to a neurodiverse student's strengths, rather than mitigating their challenges. This presentation will provide an overview of the sites and present three datasets: 1) the impact of the programs on the participants' confidence as engineering students, 2) how the programs impacted the participants' views of their neurodiversity, and 3) the profound effect exposure to academic research has on these non-traditional learners to understand engineering topics and expand their knowledge base. Consistently, these neurodiverse students reported gaining a deeper understanding of their subject matters after research, and at a significantly faster rate, than they could attain in the classroom.

In partnership with the Air Force Office of Scientific Research (AFOSR), the National Science Foundation's (NSF) Emerging Frontiers and Multidisciplinary Activities (EFMA) office of the Directorate for Engineering (ENG) launched an Emerging Frontiers in Research and Innovation (EFRI) topic for the fiscal years FY22 and FY23 entitled "Brain-inspired Dynamics for Engineering Energy-Efficient Circuits and Artificial Intelligence" (BRAID) [...].

We present a new explicit construction of onesided bipartite lossless expanders of constant degree, with arbitrary constant ratio between the sizes of the two vertex sets. Our construction is simpler to state and analyze than the only prior construction of Capalbo, Reingold, Vadhan, and Wigderson (2002), and achieves improved parameters.