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Evidence of metamorphism at ultrahigh‐pressure (UHP) conditions is documented by the presence of coesite, diamond and/or majoritic garnet. However, the growth of UHP‐stable phases such as majoritic garnet is often volumetrically low, and overprinting during exhumation can obscure evidence of UHP growth, making it difficult to positively identify UHP rocks. In this study, we selected garnet‐kyanite schists from three microdiamond‐bearing localities within the Rhodope Metamorphic Complex, located in eastern Greece. Samples from Xanthi, Sidironero, and Kimi have similar bulk rock compositions, but the pressure–temperature (P–T) paths differ. Because the major phases record vanishingly little evidence of metamorphism at UHP conditions, we analyzed zircon grains with complex textures to evaluate if zircon preserves a record of UHP metamorphism. Zircon grains from all localities have cores and rims separated by a characteristic interface domain, as revealed by cathodoluminescence (CL) imaging. The detrital igneous cores range in age from c. 2.5 Ga to 220 Ma and exhibit a negative Eu* anomaly, a Yb/Gd of 10–100, and variable Th/U (0–1.2). Rims yield dates of 150–125 Ma with Yb/Gd of 0.1–10 and Th/U of 0–0.2. Interface domains yield dates 165–145 Ma with Yb/Gd ranging between 0–1000 and Th/U < 0.2. We interpret the distinctive CL textures and Yb/Gd of the interface domains as evidence of zircon that reacted at UHP. The interface domain in zircon from all petrographic contexts yields variable Yb/Gd ratios that are significantly higher than both cores and rims. We therefore interpret that zircon recrystallized via interface‐coupled dissolution–reprecipitation reaction; this process preferentially partitioned heavy rare earth elements within the interface domain, which explains the higher Yb/Gd ratios. The rim domains equilibrated with the matrix, producing a relatively homogeneous and low Yb/Gd ratio in these domains. The spatial extent and degree of preservation of interface domains are interpreted as a function of the P–T path and minor variations in bulk composition. Interface domains are best preserved in rocks from Xanthi and Sidironero; in these samples, thin, homogeneous, garnet‐stable rims only partially overprint and crosscut the interface domain. In contrast, rocks from Kimi followed a higher‐temperature trajectory and the zircon grains grew large rim domains that overprinted much of the interface domain and the detrital core. Zircon grains from plagioclase‐rich versus quartz‐rich domains within samples from Sidironero show differences in texture, which indicates that local bulk composition can affect what evidence of UHP metamorphism is preserved. Collectively, these samples provide a new, durable marker of metamorphism in UHP rocks and yield new insight about which factors affect the preservation of UHP textures. 

Abstract Members of the familyTrichomeriaceae,belonging to theChaetothyrialesorder and theAscomycotaphylum, are known for their capability to inhabit hostile environments characterized by extreme temperatures, oligotrophic conditions, drought, or presence of toxic compounds. The genusKnufiaencompasses many polyextremophilic species. In this report, the genomic and morphological features of the strain FJI-L2-BK-P2 presented, which was isolated from the Mars 2020 mission spacecraft assembly facility located at the Jet Propulsion Laboratory in Pasadena, California. The identification is based on sequence alignment for marker genes, multi-locus sequence analysis, and whole genome sequence phylogeny. The morphological features were studied using a diverse range of microscopic techniques (bright field, phase contrast, differential interference contrast and scanning electron microscopy). The phylogenetic marker genes of the strain FJI-L2-BK-P2 exhibited highest similarities with type strain ofKnufia obscura(CBS 148926^T) that was isolated from the gas tank of a car in Italy. To validate the species identity, whole genomes of both strains (FJI-L2-BK-P2 and CBS 148926^T) were sequenced, annotated, and strain FJI-L2-BK-P2 was confirmed asK. obscura.The morphological analysis and description of the genomic characteristics ofK. obscuraFJI-L2-BK-P2 may contribute to refining the taxonomy ofKnufiaspecies. Key morphological features are reported in thisK. obscurastrain, resembling microsclerotia and chlamydospore-like propagules. These features known to be characteristic features in black fungi which could potentially facilitate their adaptation to harsh environments. 

Abstract The CODEX-βapparatus is a demonstrator for the proposed future CODEX-b experiment, a long-lived-particle detector foreseen for operation at IP8 during HL-LHC data-taking. The demonstrator project, intended to collect data in 2025, is described, with a particular focus on the design, construction, and installation of the new apparatus. 

Abstract Wetland soils are a key global sink for organic carbon (C) and a focal point for C management and accounting efforts. The ongoing push for wetland restoration presents an opportunity for climate mitigation, but C storage expectations are poorly defined due to a lack of reference information and an incomplete understanding of what drives natural variability among wetlands. We sought to address these shortcomings by (1) quantifying the range of variability in wetland soil organic C (SOC) stocks on a depressional landscape (Delmarva Peninsula, USA) and (2) investigating the role of hydrology and relative topography in explaining variability among wetlands. We found a high degree of variability within individual wetlands and among wetlands with similar vegetation and hydrogeomorphic characteristics. This suggests that uncertainty should be presented explicitly when inferring ecosystem processes from wetland types or land cover classes. Differences in hydrologic regimes, particularly the rate of water level recession, explained some of the variability among wetlands, but relationships between SOC stocks and some hydrologic metrics were eclipsed by factors associated with separate study sites. Relative topography accounted for a similar portion of SOC stock variability as hydrology, indicating that it could be an effective substitute in large-scale analyses. As wetlands worldwide are restored and focus increases on quantifying C benefits, the importance of appropriately defining and assessing reference systems is paramount. Our results highlight the current uncertainty in this process, but suggest that incorporating landscape heterogeneity and drivers of natural variability into reference information may improve how wetland restoration is implemented and evaluated. 

Strain-engineering is a powerful means to tune the polar, structural, and electronic instabilities of incipient ferroelectrics. KTaO3 is near a polar instability and shows anisotropic superconductivity in electron-doped samples. Here, we demonstrate growth of high-quality KTaO3 thin films by molecular-beam epitaxy. Tantalum was provided by either a suboxide source emanating a TaO2 flux from Ta2O5 contained in a conventional effusion cell or an electron-beam-heated tantalum source. Excess potassium and a combination of ozone and oxygen (10% O3 + 90% O2) were simultaneously supplied with the TaO2 (or tantalum) molecular beams to grow the KTaO3 films. Laue fringes suggest that the films are smooth with an abrupt film/substrate interface. Cross-sectional scanning transmission electron microscopy does not show any extended defects and confirms that the films have an atomically abrupt interface with the substrate. Atomic force microscopy reveals atomic steps at the surface of the grown films. Reciprocal space mapping demonstrates that the films, when sufficiently thin, are coherently strained to the SrTiO3 (001) and GdScO3 (110) substrates. 

Introduction: Impulsivity is a symptom of Attention-Deficit/Hyperactivity Disorder (ADHD) and variants in the Lphn3 (Adgrl3) gene [OMIM 616417] have been linked to ADHD. This project utilized a delay-discounting (DD) task to examine the impact of Lphn3 deletion in rats on impulsive choice. “Positive control” measures were also collected in Spontaneously Hypertensive Rats (SHRs), another animal model of ADHD. Methods: For Experiment I, rats were given the option to press one lever for a delayed reward of 3 food pellets or the other lever for an immediate reward of 1 pellet. Impulsive choice was measured as the tendency to discount the larger, delayed reward. We hypothesized that impulsive choice would be greater in the SHR and Lphn3 knockout (KO) rats relative to their control strains - Wistar-Kyoto (WKY) and Lphn3 wildtype (WT) rats, respectively. Results: The results did not completely support the hypothesis, as only the SHRs (but not the Lphn3 KO rats) demonstrated a decrease in the percent choice for the larger reward. Because subsequent trials did not begin until the end of the delay period regardless of which lever was selected, rats were required to wait for the next trial to start even if they picked the immediate lever. Experiment II examined whether the rate of reinforcement influenced impulsive choice by using a DD task that incorporated a 1 sec inter-trial interval (ITI) immediately after delivery of either the immediate (1 pellet) or delayed (3 pellet) reinforcer. The results of Experiment II found no difference in the percent choice for the larger reward between Lphn3 KO and WT rats, demonstrating reinforcement rate did not influence impulsive choice in Lphn3 KO rats. Discussion: Overall, there were impulsivity differences among the ADHD models, as SHRs exhibited deficits in impulsive choice, while the Lphn3 KO rats did not. 

Abstract The performance of superconducting qubits is degraded by a poorly characterized set of energy sources breaking the Cooper pairs responsible for superconductivity, creating a condition often called “quasiparticle poisoning”. Both superconducting qubits and low threshold dark matter calorimeters have observed excess bursts of quasiparticles or phonons that decrease in rate with time. Here, we show that a silicon crystal glued to its holder exhibits a rate of low-energy phonon events that is more than two orders of magnitude larger than in a functionally identical crystal suspended from its holder in a low-stress state. The excess phonon event rate in the glued crystal decreases with time since cooldown, consistent with a source of phonon bursts which contributes to quasiparticle poisoning in quantum circuits and the low-energy events observed in cryogenic calorimeters. We argue that relaxation of thermally induced stress between the glue and crystal is the source of these events. 

The Acadian and Neoacadian orogenies are widely recognized, yet poorly understood, tectono-thermal events in the New England Appalachian Mountains (USA). We quantified two phases of Paleozoic crustal thickening using geochemical proxies. Acadian (425–400 Ma) crustal thickening to 40 km progressed from southeast to northwest. Neoacadian (400–380 Ma) crustal thickening was widely distributed and varied by 30 km (40–70 km) from north to south. Doubly thickened crust and paleoelevations of 5 km or more support the presence of an orogenic plateau at ca. 380–330 Ma in southern New England. Neoacadian crustal thicknesses show a strong correlation with metamorphic isograds, where higher metamorphic grade corresponds to greater paleo-crustal thickness. We suggest that the present metamorphic field gradient was exposed through erosion and orogenic collapse influenced by thermal, isostatic, and gravitational properties related to Neoacadian crustal thickness. Geobarometry in southern New England underestimates crustal thickness and exhumation, suggesting the crust was thinned by tectonic as well as erosional processes.