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The built environment requires extraction and consumption of enormous quantities of raw materials, water, and energy. While these materials remain in use for several years or decades, growing global populations and aging infrastructure are driving widespread generation of one of the largest and most challenging waste streams to manage. There is growing interest from communities in integrating circular economy (CE) strategies in the context of construction & demolition (C&D) material management. Many approaches for doing so focus on small-scale CE applications like individual products, materials, or projects. However, greater understanding is needed at the city-scale given communities’ complex position at the frontlines of local development, resource consumption, and waste management. This study summarizes the development of an evaluative framework for community-based C&D circularity at a city or regional level. The framework expands upon a mixed methods approach called the Circularity Assessment Protocol (CAP), which integrates aspects of urban metabolism, geospatial analysis, and qualitative research methods to examine plastic waste management in communities. To advance convergent CE research, here, we aim to adapt the CAP framework to C&D. We describe our adaptation of the CAP to C&D through a conceptual review describing research, methods, and strategies related to seven elements of a local CE context: C&D Analytics, Building Material and Design, Community, Use, Collection, End-of-Cycle, and C&D Emissions. This work describes a novel yet preliminary conceptualization for developing a baseline understanding of circular C&D material management and a holistic examination of barriers, affordances, and opportunities for improving city-wide circularity. 

We propose the first practical method to detect atmospheric tau neutrino appearance at sub-GeV energies, which would be an important test of ${\nu }_{\mu }\to {\nu }_{\tau }$oscillations and of new-physics scenarios. In the Jiangmen Underground Neutrino Observatory (JUNO; starts in 2024), active-flavor neutrinos eject neutrons from carbon via neutral-current quasielastic scattering. This produces a two-part signal: the prompt part is caused by the scattering of the neutron in the scintillator, and the delayed part by its radiative capture. Such events have been observed in KamLAND, but only in small numbers and were treated as a background. With ${\nu }_{\mu }\to {\nu }_{\tau }$oscillations, JUNO should measure a clean sample of 55 events/yr; with simple ${\nu }_{\mu }$disappearance, this would instead be 41 events/yr, where the latter is determined from Super-Kamiokande charged-current measurements at similar neutrino energies. Implementing this method will require precise laboratory measurements of neutrino-nucleus cross sections or other developments. With those, JUNO will have $5\sigma$sensitivity to tau-neutrino appearance in five years of exposure, and likely sooner. Published by the American Physical Society2024 

Abstract Heritable, facultative symbionts are common in arthropods, often functioning in host defence. Despite moderately reduced genomes, facultative symbionts retain evolutionary potential through mobile genetic elements (MGEs). MGEs form the primary basis of strain‐level variation in genome content and architecture, and often correlate with variability in symbiont‐mediated phenotypes. In pea aphids (Acyrthosiphon pisum), strain‐level variation in the type of toxin‐encoding bacteriophages (APSEs) carried by the bacteriumHamiltonella defensacorrelates with strength of defence against parasitoids. However, co‐inheritance creates difficulties for partitioning their relative contributions to aphid defence. Here we identified isolates ofH. defensathat were nearly identical except for APSE type. When holdingH. defensagenotype constant, protection levels corresponded to APSE virulence module type. Results further indicated that APSEs move repeatedly within someH. defensaclades providing a mechanism for rapid evolution in anti‐parasitoid defences. Strain variation inH. defensaalso correlates with the presence of a second symbiontFukatsuia symbiotica. Predictions that nutritional interactions structured this coinfection were not supported by comparative genomics, but bacteriocin‐containing plasmids unique to co‐infecting strains may contribute to their common pairing. In conclusion, strain diversity, and joint capacities for horizontal transfer of MGEs and symbionts, are emergent players in the rapid evolution of arthropods. 

Abstract Most insects harbour influential, yet non‐essential heritable microbes in their hemocoel. Communities of these symbionts exhibit low diversity. But their frequent multi‐species nature raises intriguing questions on roles for symbiont–symbiont synergies in host adaptation, and on the stability of the symbiont communities, themselves. In this study, we build on knowledge of species‐defined symbiont community structure across US populations of the pea aphid,Acyrthosiphon pisum. Through extensive symbiont genotyping, we show that pea aphids' microbiomes can be more precisely defined at the symbiont strain level, with strain variability shaping five out of nine previously reported co‐infection trends. Field data provide a mixture of evidence for synergistic fitness effects and symbiont hitchhiking, revealing causes and consequences of these co‐infection trends. To test whether within‐host metabolic interactions predict common versus rare strain‐defined communities, we leveraged the high relatedness of our dominant, community‐defined symbiont strains vs. 12 pea aphid‐derived Gammaproteobacteria with sequenced genomes. Genomic inference, using metabolic complementarity indices, revealed high potential for cooperation among one pair of symbionts—Serratia symbioticaandRickettsiella viridis. Applying the expansion network algorithm, through additional use of pea aphid and obligateBuchnerasymbiont genomes,SerratiaandRickettsiellaemerged as the only symbiont community requiring both parties to expand holobiont metabolism. Through their joint expansion of the biotin biosynthesis pathway, these symbionts may span missing gaps, creating a multi‐party mutualism within their nutrient‐limited, phloem‐feeding hosts. Recent, complementary gene inactivation, within the biotin pathways ofSerratiaandRickettsiella, raises further questions on the origins of mutualisms and host–symbiont interdependencies.