Truncated unity functional renormalization group for multiband systems with spin-orbit coupling

Although the functional renormalization group (fRG) is by now a well-established method for investigating correlated electron systems, it is still undergoing significant technical and conceptual improvements. In particular, the motivation to optimally exploit the parallelism of modern computing platforms has recently led to the development of the "truncated-unity" functional renormalization group (TU-fRG). Here, we review this fRG variant, and we provide its extension to multiband systems with spin-orbit coupling. Furthermore, we discuss some aspects of the implementation and outline opportunities and challenges ahead for predicting the ground-state ordering and emergent energy scales for a wide class of quantum materials.Comment: consistent with published version in Frontiers in Physics (2018

Using detrending to assess SARS-CoV-2 wastewater loads as a leading indicator of fluctuations in COVID-19 cases at fine temporal scales: Correlations across twenty sewersheds in North Carolina

Wastewater surveillance emerged during the COVID-19 pandemic as a novel strategy for tracking the burden of illness in communities. Previous work has shown that trends in wastewater SARS-CoV-2 viral loads correlate well with reported COVID-19 case trends over longer time periods (i.e., months). We used detrending time series to reveal shorter sub-trend patterns (i.e., weeks) to identify leads or lags in the temporal alignment of the wastewater/case relationship. Daily incident COVID-19 cases and twice-weekly wastewater SARS-CoV-2 viral loads measured at 20 North Carolina sewersheds in 2021 were detrended using smoothing ranges of ∞, 16, 8, 4 and 2 weeks, to produce detrended cases and wastewater viral loads at progressively finer time scales. For each sewershed and smoothing range, we calculated the Spearman correlation between the cases and the wastewater viral loads with offsets of -7 to +7 days. We identified a conclusive lead/lag relationship at 15 of 20 sewersheds, with detrended wastewater loads temporally leading detrended COVID-19 cases at 11 of these sites. For the 11 leading sites, the correlation between wastewater loads and cases was greatest for wastewater loads sampled at a median lead time of 6 days before the cases were reported. Distinct lead/lag relationships were the most pronounced after detrending with smoothing ranges of 4–8 weeks, suggesting that SARS-CoV-2 wastewater viral loads can track fluctuations in COVID-19 case incidence rates at fine time scales and may serve as a leading indicator in many settings. These results could help public health officials identify, and deploy timely responses in, areas where cases are increasing faster than the overall pandemic trend

Acute mucosal pathogenesis of feline immunodeficiency virus is independent of viral dose in vaginally infected cats

<p>Abstract</p> <p>Background</p> <p>The mucosal pathogenesis of HIV has been shown to be an important feature of infection and disease progression. HIV-1 infection causes depletion of intestinal lamina propria CD4+ T cells (LPL), therefore, intestinal CD4+ T cell preservation may be a useful correlate of protection in evaluating vaccine candidates. Vaccine studies employing the cat/FIV and macaque/SIV models frequently use high doses of parenterally administered challenge virus to ensure high plasma viremia in control animals. However, it is unclear if loss of mucosal T cells would occur regardless of initial viral inoculum dose. The objective of this study was to determine the acute effect of viral dose on mucosal leukocytes and associated innate and adaptive immune responses.</p> <p>Results</p> <p>Cats were vaginally inoculated with a high, middle or low dose of cell-associated and cell-free FIV. PBMC, serum and plasma were assessed every two weeks with tissues assessed eight weeks following infection. We found that irrespective of mucosally administered viral dose, FIV infection was induced in all cats. However, viremia was present in only half of the cats, and viral dose was unrelated to the development of viremia. Importantly, regardless of viral dose, all cats experienced significant losses of intestinal CD4+ LPL and CD8+ intraepithelial lymphocytes (IEL). Innate immune responses by CD56+CD3- NK cells correlated with aviremia and apparent occult infection but did not protect mucosal T cells. CD4+ and CD8+ T cells in viremic cats were more likely to produce cytokines in response to Gag stimulation, whereas aviremic cats T cells tended to produce cytokines in response to Env stimulation. However, while cell-mediated immune responses in aviremic cats may have helped reduce viral replication, they could not be correlated to the levels of viremia. Robust production of anti-FIV antibodies was positively correlated with the magnitude of viremia.</p> <p>Conclusions</p> <p>Our results indicate that mucosal immune pathogenesis could be used as a rapid indicator of vaccine success or failure when combined with a physiologically relevant low dose mucosal challenge. We also show that innate immune responses may play an important role in controlling viral replication following acute mucosal infection, which has not been previously identified.</p

Rates and variability of hillslope erosion in steepland catchments in the Oregon Coast Range, Pacific Northwest, USA

Hillslope soil residence time (average particle age making up the soil) reflects the rates of soil production (= bedrock erosion) and soil transport, and thus is a useful parameter for quantifying hillslope dynamics. On steady state hillslopes, the distribution of particle ages is determined by soil production rate, soil depth and soil and bedrock density. This distribution, used in combination with chronofunctions describing soil weathering at a particle scale, can be used to derive expressions relating hillslope soil properties to soil residence time. Thus soil properties can be used to estimate soil residence time and quantify hillslope dynamics. We analysed variability of soil residence time at a broad scale and a fine scale in the Oregon Coast Range in the Pacific Northwest, USA. Our results are consistent with an approximate balance of erosion rate and rock uplift rate for a large part of our study area, but at both scales, parts of the landscape with long soil residence time were identified. We attribute the lower erosion rates and slower soil transport (contributing to long soil residence time) in these areas to decoupling from base-level lowering

How steady are steady-state landscapes? Using visible-near-infrared soil spectroscopy to quantify erosional variability

Although topographic steady state is often used as a simplifying assumption in sediment yield studies and landscape evolution models, the temporal and spatial scales over which this assumption applies in natural landscapes are poorly defined. We used visible–near-infrared (visNIR) spectroscopy to measure the weathering of hilltop soils and quantify local erosional variability in two watersheds in the Oregon Coast Range (United States). One watershed appears adjusted to base-level lowering driven by rock uplift in the Cascadia forearc, while the other is pinned by a gabbroic dike that locally slows river incision and hillslope erosion. Models for uniformly eroding hillslopes imply uniform soil residence times; instead, we observe significant variability around the mean value of 18.8 k.y. (+31.2/–11.8 k.y.) for our adjusted watershed. The magnitude of erosional variability likely reflects the time scales associated with stochastic processes that drive bedrock weathering, soil production, and soil transport (e.g., tree turnover). The residence time distribution for our pinned watershed has a mean value of 72.9 k.y. (+165.6/–50.6 k.y.) and is highly skewed with a substantial fraction of long residence time soils. We speculate that this pattern results from the lithologic control of base level and lateral divide migration driven by erosional contrasts with neighboring catchments. Our novel and inexpensive methodology enables us to quantify for the first time the magnitude of erosional variability in a natural landscape, and thus provides important geomorphic context for studies characterizing regolith development. More generally, we demonstrate that soils can record catchment-scale landscape dynamics that may arise from lithologic controls or forcing due to climate or tectonics

Rapid-DEM: Rapid Topographic Updates through Satellite Change Detection and UAS Data Fusion

As rapid urbanization occurs in cities worldwide, the importance of maintaining updated digital elevation models (DEM) will continue to increase. However, due to the cost of generating high-resolution DEM over large spatial extents, the temporal resolution of DEMs is coarse in many regions. Low-cost unmanned aerial vehicles (UAS) and DEM data fusion provide a partial solution to improving the temporal resolution of DEM but do not identify which areas of a DEM require updates. We present Rapid-DEM, a framework that identifies and prioritizes locations with a high likelihood of an urban topographic change to target UAS data acquisition and fusion to provide up-to-date DEM. The framework uses PlanetScope 3 m satellite imagery, Google Earth Engine, and OpenStreetMap for land cover classification. GRASS GIS generates a contextualized priority queue from the land cover data and outputs polygons for UAS flight planning. Low-cost UAS fly the identified areas, and WebODM generates a DEM from the UAS survey data. The UAS data is fused with an existing DEM and uploaded to a public data repository. To demonstrate Rapid-DEM a case study in the Walnut Creek Watershed in Wake County, North Carolina is presented. Two land cover classification models were generated using random forests with an overall accuracy of 89% (kappa 0.86) and 91% (kappa 0.88). The priority queue identified 109 priority locations representing 1.5% area of the watershed. Large forest clearings were the highest priority locations, followed by newly constructed buildings. The highest priority site was a 0.5 km2 forest clearing that was mapped with UAS, generating a 15 cm DEM. The UAS DEM was resampled to 3 m resolution and fused with USGS NED 1/9 arc-second DEM data. Surface water flow was simulated over the original and updated DEM to illustrate the impact of the topographic change on flow patterns and highlight the importance of timely DEM updates