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Cationic water-soluble deep cavitands enable hierarchical assembly-based recognition, optical detection and extraction of perfluoroalkyl substances (PFAS) in aqueous solution. Recognition of the PFAS occurs at the lower rim crown of the cavitand, which triggers self-aggregation of a PFAS-cavitand complex, allowing extraction from water. In addition, when paired with an indicator dye that can be bound in the cavity of the host molecule, the PFAS-cavitand association causes a significant (>20-fold at micromolar [PFAS]) enhancement of dye fluorescence due to conformational rearrangement of the fluxional cavitand AMI, allowing optical sensing of PFAS. The cavitands are water-soluble, and the detection and recognition occur in purely aqueous solution. The association is most effective for long chain sulfonate PFAS, and as such, selective optical detection of perfluorooctanesulfonate is possible, with a LOD = 130 nM in buffered water, and 500 nM in real-world samples such as polluted canal water. By pairing the AMI host with multiple dyes in an array-based format, full discrimination of five other PFAS can be achieved at micromolar concentration via differential sensing. In addition, the aggregation process allows extraction of PFAS from solution, and a 99% reduction of PFOS concentration in water is possible with a single treatment of an equimolar concentration of AMI cavitand. The hierarchical nature of the cavitand recognition system allows both selective, sensitive optical detection and extraction of PFAS from water with a single scaffold. 

Gram-positive bacteria are some of the earliest known life forms, diverging from gram-negative bacteria 2 billion years ago. These organisms utilize sortase enzymes to attach proteins to their peptidoglycan cell wall, a structural feature that distinguishes the two types of bacteria. The transpeptidase activity of sortases make them an important tool in protein engineering applications, e.g., in sortase-mediated ligations or sortagging. However, due to relatively low catalytic efficiency, there are ongoing efforts to create better sortase variants for these uses. Here, we use bioinformatics tools, principal component analysis and ancestral sequence reconstruction, in combination with protein biochemistry, to analyze natural sequence variation in these enzymes. Principal component analysis on the sortase superfamily distinguishes previously described classes and identifies regions of relatively high sequence variation in structurally-conserved loops within each sortase family, including those near the active site. Using ancestral sequence reconstruction, we determined sequences of ancestral Staphylococcus and Streptococcus Class A sortase proteins. Enzyme assays revealed that the ancestral Streptococcus enzyme is relatively active and shares similar sequence variation with other Class A Streptococcus sortases. Taken together, we highlight how natural sequence variation can be utilized to investigate this important protein family, arguing that these and similar techniques may be used to discover or design sortases with increased catalytic efficiency and/or selectivity for sortase-mediated ligation experiments. 

Consumer-mediated movement can couple food webs in distinct habitats and facilitate energy flow between them. In New England saltmarshes, mummichogs (Fundulus heteroclitus) connect the vegetated marsh and creek food webs by opportunistically foraging on the invertebrate communities of the marsh surface when access is permitted by tidal flooding and marsh-edge geomorphology. Via their movements, mummichog represent a critical food web node, as they can potentially transport energy from the marsh surface food web to creek food web and exert top-down control on the communities of the vegetated marsh surface. Here, I use gut content analysis, calorimetric analysis, and field surveys to demonstrate that access to the marsh surface (afforded by marsh-edge geomorphology) impacts the trophic relay of marsh production to creek food webs. Fish populations in creeks with greater connectivity had a higher total biomass of terrestrial invertebrates in their guts. However, bomb calorimetry showed no difference in the average caloric content of mummichog individuals from creeks with different creek edge geomorphology. Access also did not impact mummichog distribution across the marsh platform and exhibited no evidence of top-down control on their invertebrate prey. Thus, mummichogs function as initial nodes in the trophic relay, unidirectionally moving energy from the vegetated marsh to the creek food web. Reduced marsh surface access via altered marsh-edge geomorphology results in a 50 % to 66 % reduction in total energy available to aquatic predators via this route. Estuarine systems are intimately connected to coastal and offshore systems via consumer mediated flows of energy; thus, disruptions to the trophic relay from the marsh surface at the tidal creek scale can have far reaching impacts on secondary productivity in multiple disparate systems and must be accounted for in considerations of impacts to future food-web function. 

Presentation by OSC Sys Admins at the ACM SIGHPC SYSPROS Symposium held in conjunction with the PEARC19 conference 

Project update from the Open OnDemand User Group meeting held at the PEARC 19 conference 

The branching fraction of the decay $B^{+}\to \psi \left(2S\right)\varphi \left(1020\right)K^{+}$, relative to the topologically similar decay $B^{+}\to J/\psi \varphi \left(1020\right)K^{+}$, is measured using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$. The ratio is found to be $0.061\pm 0.004\pm 0.009$, where the first uncertainty is statistical and the second systematic. Using the world-average branching fraction for $B^{+}\to J/\psi \varphi \left(1020\right)K^{+}$, the branching fraction for the decay $B^{+}\to \psi \left(2S\right)\varphi \left(1020\right)K^{+}$is found to be $(3.0\pm 0.2\pm 0.5\pm 0.2)\times {10}^{-6}$, where the first uncertainty is statistical, the second systematic, and the third is due to the branching fraction of the normalization channel. © 2025 CERN, for the LHCb Collaboration2025CERN