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On August 13-14, 2025, the Jackson School of Geoscience hosted the inaugural North American Workshop on Critical Mineral Research, Development and Education, in the Thompson Conference Center on the campus of the University of Texas at Austin, USA. The workshop was funded by the National Science Foundation (NSF) and was attended by 230 participants. 176 participants attended the workshop in-person while another 54 participants attended online via Zoom. Twenty-two participants (including 10 students and 7 early career researchers) received travel support through the NSF grant to attend the workshop in Austin. Out of the 230 workshop participants, 134 participants were from academia (34 students), 66 from the private sector and 30 from federal- and state-level government agencies. The workshop was divided into four topical sessions that discussed current issues in critical minerals research, development, and education: (A) Conventional and Unconventional Sources of Critical Minerals. (B) How to grow the U.S. critical minerals workforce. (C) Innovations in Critical Mineral Extraction and Recycling. (D) Policy and Supply Chain Economics. The topical sessions were composed of two keynote lectures and complemented by oral and poster presentations by the workshop participants. A panel discussion and breakout session explored recent developments in critical minerals research, development and education in the U.S., with particular focus on the implications of recent Presidential Executive Orders. The discussions highlighted, for example, that: (i) The recent critical mineral-related Presidential Executive Orders by the Trump-Vance administration are encouraging steps towards fast-tracking US-based critical mineral production. (ii) Lengthy permitting timelines and limited transparency in the decision-making process – with often unpredictable outcomes – remain major barriers for mining and mineral processing operations in the U.S. Workshop participants suggested the development of policies specifically aimed at streamlining permitting processes. (iii) Funding initiatives are too often aimed at increasing short-to-mid-term critical mineral production while generation of ‘pre-competitive data’ to support and guide mineral exploration is largely neglected. Workshop participants recommended that future funding cycles place greater emphasis on generating fundamental geoscience data and insight that can be leveraged by the private sector for green and brownfield exploration. (iv) The persistent negative image of the mining and mineral processing sector remains a major obstacle to attracting and developing a skilled critical minerals workforce. As possible starting points for long-term solutions, workshop participants suggested launching a media campaign, implementing industry-led K-12 outreach programs, and stronger and closer collaborations between academia and the private sector through student-centered research projects. 

The palladium-catalyzed sp-sp2 C−C bond forming the Sonogashira reaction has been both extensively studied mechanistically and widely used in organic synthesis. Herein, we describe an investigation into how a palladium(II) complex with arylazoformamide (AAF) ligands mediates these transformations. When mixed, two AAFs coordinate in a κ1-fashion with an equivalent of PdCl2, creating complexes of the form PdCl2(AAF)2. Under typical and optimized copper(I)-cocatalyzed Sonogashira conditions, using phenylacetylene and iodobenzene as reagents, these complexes (precatalysts) reduce to Pd(0) and afford the coupled diphenylacetylene product in high yields (i.e., 99%). A substrate scope explored the substitution on both rings, yielding 18 examples with yields varying from 38 to 99%. Mechanistically, from DFT studies, a formal Pd(I) open-shell singlet complex is suggested, along with an explanation of the need for DBU when employing CuI in toluene. Further DFT exploration provides insight into the copper-free Sonogashira reaction when utilizing Pd(AAF)2 complexes. 

ABSTRACT Bacteria shape interactions between hosts and fungal pathogens. In some cases, bacteria associated with fungi are essential for pathogen virulence. In other systems, host-associated microbiomes confer resistance against fungal pathogens. We studied an aphid-specific entomopathogenic fungus calledPandora neoaphidisin the context of both host and pathogen microbiomes. Aphids host several species of heritable bacteria, some of which confer resistance againstPandora. We first found that spores that emerged from aphids that harbored protective bacteria were less virulent against subsequent hosts and did not grow on plate media. We then used 16S amplicon sequencing to study the bacterial microbiome of fungal mycelia and spores during plate culturing and host infection. We found that the bacterial community is remarkably stable in culture despite dramatic changes in pathogen virulence. Last, we used an experimentally transformed symbiont of aphids to show thatPandoracan acquire host-associated bacteria during infection. Our results uncover new roles for bacteria in the dynamics of aphid-pathogen interactions and illustrate the importance of the broader microbiological context in studies of fungal pathogenesis. IMPORTANCEEntomopathogenic fungi play important roles in the population dynamics of many insect species. Understanding the factors shaping entomopathogen virulence is critical for agricultural management and for the use of fungi in pest biocontrol. We show that heritable bacteria in aphids, which confer protection to their hosts against fungal entomopathogens, influence virulence against subsequent hosts. Aphids reproduce asexually and are typically surrounded by genetically identical offspring, and thus these effects likely shape the dynamics of fungal disease in aphid populations. Furthermore, fungal entomopathogens are known to rapidly lose virulence in lab culture, complicating their laboratory use. We show that this phenomenon is not driven by changes in the associated bacterial microbiome. These results contribute to our broader understanding of the aphid model system and shed light on the biology of the Entomophthorales—an important but understudied group of fungi. 

Abstract Many insects harbor heritable microbes that influence host phenotypes. Symbiont strains establish at different densities within hosts. This variation is important evolutionarily because within-host density has been linked to the costs and benefits of the symbiosis for both partners. Studying the factors shaping within-host density is important to our broader understanding of host–microbe coevolution. Here we focused on different strains of Regiella insecticola, a facultative symbiont of aphids. We first showed that strains of Regiella establish in pea aphids at drastically different densities. We then found that variation in density is correlated with the expression levels of two key insect immune system genes (phenoloxidase and hemocytin), with the suppression of immune gene expression correlating with higher Regiella density. We then performed an experiment where we established coinfections of a higher- and a lower-density Regiella strain, and we showed that the higher-density strain is better able to persist in coinfections than the lower-density strain. Together, our results point to a potential mechanism that contributes to strain-level variation in symbiont density in this system, and our data suggest that symbiont fitness may be increased by establishing at higher density within hosts. Our work highlights the importance of within-host dynamics shaping symbiont evolution. 

Abstract Increased use and improved methodology of carbonate clumped isotope thermometry has greatly enhanced our ability to interrogate a suite of Earth‐system processes. However, interlaboratory discrepancies in quantifying carbonate clumped isotope (Δ₄₇) measurements persist, and their specific sources remain unclear. To address interlaboratory differences, we first provide consensus values from the clumped isotope community for four carbonate standards relative to heated and equilibrated gases with 1,819 individual analyses from 10 laboratories. Then we analyzed the four carbonate standards along with three additional standards, spanning a broad range of δ⁴⁷and Δ₄₇values, for a total of 5,329 analyses on 25 individual mass spectrometers from 22 different laboratories. Treating three of the materials as known standards and the other four as unknowns, we find that the use of carbonate reference materials is a robust method for standardization that yields interlaboratory discrepancies entirely consistent with intralaboratory analytical uncertainties. Carbonate reference materials, along with measurement and data processing practices described herein, provide the carbonate clumped isotope community with a robust approach to achieve interlaboratory agreement as we continue to use and improve this powerful geochemical tool. We propose that carbonate clumped isotope data normalized to the carbonate reference materials described in this publication should be reported as Δ₄₇(I‐CDES) values for Intercarb‐Carbon Dioxide Equilibrium Scale.