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Abstract Fish skulls are often highly kinetic, with multiple linkage and lever systems powered by a diverse suite of muscles. Comparative analysis of the evolution of soft-tissue structures in the fish skull is often limited under traditional approaches, while new imaging techniques like diceCT (diffusible iodine-based contrast-enhanced computed tomography) allow for high-resolution imaging of muscles in situ. Darters (Percidae: Etheostomatinae) are a diminutive and species-rich clade of lotic freshwater fishes, which show diverse head shapes believed to be associated with different foraging strategies. We used diceCT to sample all major cranial adductors and abductors responsible for movement of the jaw, hyoid, operculum, and suspensorium from 29 species. We applied comparative phylogenetic approaches to analyse the evolutionary trends in muscle size across the clade. We found two major patterns: (i) darter cranial muscles show fundamental trade-offs relating to investment in musculature, as well as buccal expansion vs. biting attributes; early divergence in muscle size appears to be associated with shifts in habitat use and foraging; (ii) darter adductor mandibulae show high variation in architecture (fibre orientation, divisions). This study highlights how new imaging techniques can provide novel insights into the anatomy of even well-sampled/represented clades. 

On August 7-8, 2024, the Thomas J. O’Keefe Institute for Sustainable Supply of Strategic Minerals at Missouri University of Science and Technology (Missouri S&T) hosted the fourth annual workshop on ‘Resilient Supply of Critical Minerals’. The workshop was funded by the National Science Foundation (NSF) and was attended by 212 participants. 143 participants attended the workshop in-person in the Havener Center on the Missouri S&T campus in Rolla, Missouri, USA. Another 69 participants attended online via Zoom. Twenty participants (including 12 students and 4 early career researchers) received travel support through the NSF grant to attend the conference in Rolla. Out of the workshop 212 participants, 199 stated their sectors of employment during registration showing that 88 participants were from academia (34 students), 58 from the private sector and 53 from government agencies. The workshop was followed by a post-workshop field trip to US Strategic Minerals (formerly Missouri Cobalt) in southeast Missouri that was attended by 18 workshop participants from academia (n=11; including 4 students) and the private sector (n=7). Four topical sessions were covered during the workshop: A. The Critical Mineral Potential of the USA: Evaluation of existing, and exploration for new resources. B. Critical Minerals Workforce Development: How to grow the US critical minerals workforce. C. Critical Mineral Processing and Recycling: Maximizing critical mineral recovery from existing production streams. D. Critical Mineral Policy and Supply Chain Economics: Reshoring critical mineral production. The topical sessions were composed of two keynote lectures and complemented by oral and poster presentations by the workshop participants, as well as a 30-minute open discussion at the end of each topical session. Breakout sessions that concluded each day discussed: • Can mining lead the new materials future? • Critical minerals research: where to go from here? • Should the Bureau of Mines be restored? Discussions during the workshop highlighted, for example, that: (i) Mining companies need to better address downstream needs and develop company cultures inclusive of younger generations; (ii) Although funding opportunities over the past year’s started to make a difference for critical minerals supply chain resilience, additional funding that is aimed at strengthening academia – private sector partnerships as well as international collaborations is needed to ensure a long-term impact; (iii) The majority of participants would welcome the reestablishment of the Bureau of Mines, although no consensus was reached on its potential responsibilities. This workshop report provides a detailed summary of the workshop demographics and discussions. 

The 3D dust complexity maps used in the main result of Section 4 <a href="https://arxiv.org/abs/2404.11009">"Imprints of the Local Bubble and Dust Complexity on Polarized Dust Emission," Halal et al. 2024</a>. Use of these data must cite that paper. We provide 12 maps, corresponding to the 12 posterior sample 3D dust extinction maps of <a href="https://www.aanda.org/articles/aa/full_html/2024/05/aa47628-23/aa47628-23.html">Edenhofer et al. 2023</a>, which extend radially out to 1.25 kpc. The maps we provide are in Galactic coordinates and are only defined over the masks described in <a href="https://arxiv.org/abs/2404.11009">Halal et al. 2024</a>. 

Extrusion-based 3D bioprinting is a promising method for repairing patient-specific tissues and organs due to its inherent capacity to release biocompatible materials containing living cells in a preset area. The filament geometry and width mostly determine the scaffold architecture. Extrusion pressure, print speed, print distance, nozzle diameter, and material viscosity are just a few of the process variables that can be carefully chosen to affect the filament shape and width, ultimately verifying the user-defined scaffold porosity. To maintain defined filament width variation for various hydrogels within an acceptable range and to confirm the overall geometric fidelity of the scaffold, in this paper, filament width for a set of biomaterial compositions was determined using an image processing technique and an analytical relationship, including various process parameters, was developed. 

Extrusion-based three-dimensional (3D) bio-printing is one of the several 3D bioprinting methods that is frequently used in current times. This method enables the accurate deposition of cell-laden bio-ink while ensuring a predetermined scaffold architecture that may allow living tissue regeneration. Natural hydrogels are a strong choice for bio-ink formulation for the extrusion-based 3D bioprinting method because they have a combination of unique properties, which include biocompatibility, reduced cell toxicity, and high-water content. However, due to its low mechanical integrity, hydrogel frequently struggles to retain structural stability. To overcome this challenge, we evaluated the rheological characteristics of distinct hybrid hydrogels composed of carboxymethyl cellulose (CMC), a widely used alginate, and nanofibers generated from cellulose (TEMPO-mediated nano-fibrillated cellulose, TONFC). Therefore, to examine the rheological properties, a set of compositions was developed incorporating CMC (1%–4%), alginate (1%–4%), and higher and lower contents of TONFC (0.5%) and (0.005%) respectively. From the flow diagram, the shear thinning coefficients of n and K were calculated, which were later linked to the 3D printability. With the guidance of diverse nanofiber ratios, it is possible to regulate the rheological properties and create 3D bioprinted scaffolds with well-defined scaffold architecture. 

Traditional static cell culture methods don't guarantee access to medium inside areas or through the scaffolds because of the complex three-dimensional nature of the 3D bio-printed scaffolds. The bioreactor provides the necessary growth medium encapsulated and seeded cells in 3D bioprinted scaffolds. The constant flow of new growing medium could promote more viable and multiplying cells. Therefore, we created a specialized perfusion bioreactor that dynamically supplies the growth medium to the cells implanted or encapsulated in the scaffolds. A redesigned configuration of our developed bioreactor may enhance the in vivo stimuli and circumstances, ultimately improving the effectiveness of tissue regeneration. This study investigated how different scaffold pore shapes and porosities affect the flow. We employed a simulation technique to calculate fluid flow turbulence across several pore geometries, including uniform triangular, square, circular, and honeycomb. We constructed a scaffold with changing pore diameters to examine the fluid movement while maintaining constant porosity. The impact of fluid flow was then determined by simulating and mimicking the architecture of bone tissue. The best scaffold designs were chosen based on the findings. 

The emerging field of three-dimensional bio-printing seeks to recreate functional tissues for medical and pharmaceutical purposes. With the ability to print diverse materials containing different living cells, this growing area may bring us closer to achieving tissue regeneration. In previous research, we developed a Y-shaped nozzle connection device that facilitated the continuous deposition of materials across multiple filaments. This plastic device had a fixed switching angle and was intended for single use. In this study, we present an extension of our previous nozzle system. To fabricate the nozzle connectors, we chose stainless steel and considered angles of 300, 450, and 900 (both vertical and tilted) between the two materials. The total material switching time was recorded and compared to analyze the effects of these angles. We used our previously developed hybrid hydrogel (4% Alginate and 4% Carboxymethyl Cellulose, CMC) as a test material to flow through the nozzle system. These in-house fabricated nozzle connectors are reusable, and sterile and enable smooth material transition and flow. 

We present the magnetic and structural properties of [Cu(pyrazine)0.5(glycine)]ClO4 under applied pressure. As previously reported, at ambient pressure this material consists of quasi-two-dimensional layers of weakly coupled antiferromagnetic dimers which undergo Bose-Einstein condensation of triplet excitations between two magnetic field-induced quantum critical points (QCPs). The molecular building blocks from which the compound is constructed give rise to exchange strengths that are considerably lower than those found in other S = 1/2 dimer materials, which allows us to determine the pressure evolution of the entire field-temperature magnetic phase diagram using radio-frequency magnetometry. We find that a distinct phase emerges above the upper field-induced transition at elevated pressures and also show that an additional QCP is induced at zero field at a critical pressure of pc = 15.7(5) kbar. Pressure-dependent single-crystal x-ray diffraction and density functional theory calculations indicate that this QCP arises primarily from a dimensional crossover driven by an increase in the interdimer interactions between the planes. While the effect of quantum fluctuations on the lower field-induced transition is enhanced with applied pressure, quantum Monte Carlo calculations suggest that this alone cannot explain an unconventional asymmetry that develops in the phase diagram.