A Multilevel Method for Many-Electron Schr\"{o}dinger Equations Based on the Atomic Cluster Expansion

The atomic cluster expansion (ACE) (Drautz, 2019) yields a highly efficient and intepretable parameterisation of symmetric polynomials that has achieved great success in modelling properties of many-particle systems. In the present work we extend the practical applicability of the ACE framework to the computation of many-electron wave functions. To that end, we develop a customized variational Monte-Carlo algorithm that exploits the sparsity and hierarchical properties of ACE wave functions. We demonstrate the feasibility on a range of proof-of-concept applications to one-dimensional systems

Yanghe Decoction Suppresses the Experimental Autoimmune Thyroiditis in Rats by Improving NLRP3 Inflammasome and Immune Dysregulation

Inflammation is an important contributor to autoimmune thyroiditis. Yanghe decoction (YH) is a traditional Chinese herbal formulation which has various anti-inflammatory effects. It has been used for the treatment of autoimmune diseases such as ankylosing spondylitis In this study we aimed to investigate the effects of YH on autoimmune thyroiditis in a rat model and elucidate the underlying mechanisms. The experimental autoimmune thyroiditis (EAT) model was established by thyroglobulin (pTG) injections and excessive iodine intake. Thyroid lesions were observed using hematoxylin and eosin (H and E) staining and serum TgAb, TPOAb, TSH, T3, and T4 levels were measured by enzyme-linked immunosorbent assay IL-35 levels were evaluated using real-time polymerase chain reaction (RT-PCR) and Th17/Treg balance in peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry and RT-PCR. Changes in Wnt/β-catenin signaling were evaluated using Western blot. Immunofluorescence staining and western blot were employed to examine NLRP3 inflammasome activation in the thyroid. YH minimized thyroid follicle injury and decreased concentrations of serum TgAb, TPOAb, TSH, T3, and T4 in EAT model. The mRNA of IL-35 was increased after YH treatment. YH also increased the percentage of Treg cells, and decreased Th17 proportion as well as Th17/Treg ratio in PBMCs. Meanwhile, the mRNA levels of Th17 related cytokines (RORγt, IL-17A, IL-21, and IL-22) were suppressed and Treg related cytokines (FoxP3, TGF-β, and IL-10) were promoted in PBMCs. Additionally, the protein expressions of Wnt-1 and β-catenin were unregulated after YH treatment. NLRP3 immunostaining signal and protein levels of IL-17, p-NF-κB, NLRP3, ASC, cleaved-Caspase-1, cleaved-IL-1β, and IL-18 were downregulated in the thyroid after YH intervention. Overall, the present study demonstrated that YH alleviated autoimmune thyroiditis in rats by improving NLRP3 inflammasome and immune dysregulation

Taking the pulse of COVID-19: A spatiotemporal perspective

The sudden outbreak of the Coronavirus disease (COVID-19) swept across the world in early 2020, triggering the lockdowns of several billion people across many countries, including China, Spain, India, the U.K., Italy, France, Germany, and most states of the U.S. The transmission of the virus accelerated rapidly with the most confirmed cases in the U.S., and New York City became an epicenter of the pandemic by the end of March. In response to this national and global emergency, the NSF Spatiotemporal Innovation Center brought together a taskforce of international researchers and assembled implemented strategies to rapidly respond to this crisis, for supporting research, saving lives, and protecting the health of global citizens. This perspective paper presents our collective view on the global health emergency and our effort in collecting, analyzing, and sharing relevant data on global policy and government responses, geospatial indicators of the outbreak and evolving forecasts; in developing research capabilities and mitigation measures with global scientists, promoting collaborative research on outbreak dynamics, and reflecting on the dynamic responses from human societies.Comment: 27 pages, 18 figures. International Journal of Digital Earth (2020

Differential effects of exogenous and endogenous cueing in multi-stream RSVP: implications for theories of attentional blink

The attentional blink (AB) refers to the finding that performance on the second of two targets (T1 and T2) in a rapid serial visual presentation (RSVP) stream is impaired when the targets are presented within 200–500 ms. To explore the possible interaction between spatial attentional orienting and temporary attentional deficits, this study used central (endogenous) and peripheral (exogenous) cues in a multi-stream RSVP task and compared the endogenous and exogenous cueing effects inside and outside of the AB period. While the endogenous cueing effect was constant in magnitude over time, the exogenous cueing effect was significantly larger inside than outside of the AB period. Theoretical implications of these findings for the interaction between attention mechanisms in spatial and temporal domains are discussed

Top-down control is not lost in the attentional blink: evidence from intact endogenous cuing.

The attentional blink (AB) refers to the finding that performance on the second of two targets (T1 and T2) is impaired when the targets are presented at a target onset asynchrony (TOA) of less than 500 ms. One account of the AB assumes that the processing load of T1 leads to a loss of top-down control over stimulus selection. The present study tested this account by examining whether an endogenous spatial cue that indicates the location of a following T2 can facilitate T2 report even when the cue and T2 occur within the time window of the AB. Results from three experiments showed that endogenous cuing had a significant effect on T2 report, both during and outside of the AB; this cuing effect was modulated by both the cue-target onset asynchrony and by cue validity, while it was invariant to the AB. These results suggest that top-down control over target selection is not lost during the AB. © 2007 Springer-Verlag

The impact of negative attentional set upon target processing in RSVP:An ERP study

This study investigates whether the negative attentional set, a form of top-down attentional bias, can be set up on a trial-by-trial basis and impair online target processing in an RSVP (Rapid Serial Visual Presentation) task in which two targets are to be identified. Using the N2pc (N2 posterior contralateral) a component in the event-related potential (ERP) evoked by lateralized targets - as an index of attentional selection, we demonstrated that the online processing of the second target (T2) can be inhibited by a category-specific negative attentional set elicited by a special distractor (D1) prior to the first target (T1) and that this attentional set can be set up at an abstract, conceptual level. A digit T2 was presented on the left or right following a central RSVP letter stream which had a unique red letter T1. Another digit or a Chinese number character was presented prior to T1 as D1, which had to be ignored. Relative to the D1 absent condition, either type of D1 impaired T2 performance and delayed the N2pc response to T2. D1 elicited a frontocentral N2 peaking at about 300 ms post-onset of D1, suggesting that D1 is indeed an inhibition-evoking stimulus. A further behavioral experiment ruled out the possibility that D1 impairs T2 performance via attentional capture or a category-unspecific, general negative attentional set. (C) 2009 Elsevier Ltd. All rights reserved

Negative attentional set in the attentional blink: control is not lost

The attentional blink (AB) refers to the finding that performance on the second of two targets (T1 and T2) in a rapidly presented stimulus stream is impaired when the targets are presented within 200-500 ms. This study investigates whether a negative attentional set, a form of top-down control, has an additional detrimental effect, and whether its influence is modulated by task demands. A negative attentional set was elicited through presentation of a pre-T1 distractor (D1), which belonged to the same category as T2. The presence of D1 impaired T2 performance, and this negative effect was generally larger inside than outside the AB. Moreover, this D1 effect remained constant or was augmented when the demand on T1 processing was enhanced. These findings demonstrate that a negative attentional set is maintained even though the central system is engaged in the in-depth processing of T1 during the AB

Analyses on the Multimodel Wind Forecasts and Error Decompositions over North China

In this study, wind forecasts derived from the European Centre for Medium-Range Weather Forecasts (ECMWF), the National Centers for Environmental Prediction (NCEP), the Japan Meteorological Agency (JMA) and the United Kingdom Meteorological Office (UKMO) are evaluated for lead times of 1–7 days at the 10 m and multiple isobaric surfaces (500 hPa, 700 hPa, 850 hPa and 925 hPa) over North China for 2020. The straightforward multimodel ensemble mean (MME) method is utilized to improve forecasting abilities. In addition, the forecast errors are decomposed to further diagnose the error sources of wind forecasts. Results indicated that there is little difference in the performances of the four models in terms of wind direction forecasts (DIR), but obvious differences occur in the meridional wind (U), zonal wind (V) and wind speed (WS) forecasts. Among them, the ECMWF and NCEP showed the highest and lowest abilities, respectively. The MME effectively improved wind forecast abilities, and showed more evident superiorities at higher levels for longer lead times. Meanwhile, all of the models and the MME manifested consistent trends of increasing (decreasing) errors for U, V and WS (DIR) with rising height. On the other hand, the main source of errors for wind forecasts at both 10 m and isobaric surfaces was the sequence component (SEQU), which rose rapidly with increasing lead times. The deficiency of the less proficient NCEP model at the 10 m and isobaric surfaces could mainly be attributed to the bias component (BIAS) and SEQU, respectively. Furthermore, the MME tended to produce lower SEQU than the models at all layers, which was more obvious at longer lead times. However, the MME showed a slight deficiency in reducing BIAS and the distribution component of forecast errors. The results not only recognized the model forecast performances in detail, but also provided important references for the use of wind forecasts in business departments and associated scientific researches

Analyses on the Multimodel Wind Forecasts and Error Decompositions over North China

In this study, wind forecasts derived from the European Centre for Medium-Range Weather Forecasts (ECMWF), the National Centers for Environmental Prediction (NCEP), the Japan Meteorological Agency (JMA) and the United Kingdom Meteorological Office (UKMO) are evaluated for lead times of 1–7 days at the 10 m and multiple isobaric surfaces (500 hPa, 700 hPa, 850 hPa and 925 hPa) over North China for 2020. The straightforward multimodel ensemble mean (MME) method is utilized to improve forecasting abilities. In addition, the forecast errors are decomposed to further diagnose the error sources of wind forecasts. Results indicated that there is little difference in the performances of the four models in terms of wind direction forecasts (DIR), but obvious differences occur in the meridional wind (U), zonal wind (V) and wind speed (WS) forecasts. Among them, the ECMWF and NCEP showed the highest and lowest abilities, respectively. The MME effectively improved wind forecast abilities, and showed more evident superiorities at higher levels for longer lead times. Meanwhile, all of the models and the MME manifested consistent trends of increasing (decreasing) errors for U, V and WS (DIR) with rising height. On the other hand, the main source of errors for wind forecasts at both 10 m and isobaric surfaces was the sequence component (SEQU), which rose rapidly with increasing lead times. The deficiency of the less proficient NCEP model at the 10 m and isobaric surfaces could mainly be attributed to the bias component (BIAS) and SEQU, respectively. Furthermore, the MME tended to produce lower SEQU than the models at all layers, which was more obvious at longer lead times. However, the MME showed a slight deficiency in reducing BIAS and the distribution component of forecast errors. The results not only recognized the model forecast performances in detail, but also provided important references for the use of wind forecasts in business departments and associated scientific researches