Adaptive sparse grid algorithms with applications to electromagnetic scattering under uncertainty

We discuss adaptive sparse grid algorithms for stochastic differential equations with a particular focus on applications to electromagnetic scattering by structures with holes of uncertain size, location, and quantity. Stochastic collocation (SC) methods are used in combination with an adaptive sparse grid approach based on nested Gauss-Patterson grids. As an error estimator we demonstrate how the nested structure allows an effective error estimation through Richardson extrapolation. This is shown to allow excellent error estimation and it also provides an efficient means by which to estimate the solution at the next level of the refinement. We introduce an adaptive approach for the computation of problems with discrete random variables and demonstrate its efficiency for scattering problems with a random number of holes. The results are compared with results based on Monte Carlo methods and with Stroud based integration, confirming the accuracy and efficiency of the proposed techniques. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved

Adaptive sparse grid algorithms with applications to electromagnetic scattering under uncertainty

We discuss adaptive sparse grid algorithms for stochastic differential equations with a particular focus on applications to electromagnetic scattering by structures with holes of uncertain size, location, and quantity. Stochastic collocation (SC) methods are used in combination with an adaptive sparse grid approach based on nested Gauss-Patterson grids. As an error estimator we demonstrate how the nested structure allows an effective error estimation through Richardson extrapolation. This is shown to allow excellent error estimation and it also provides an efficient means by which to estimate the solution at the next level of the refinement. We introduce an adaptive approach for the computation of problems with discrete random variables and demonstrate its efficiency for scattering problems with a random number of holes. The results are compared with results based on Monte Carlo methods and with Stroud based integration, confirming the accuracy and efficiency of the proposed techniques

Continuous monitoring of the isotopic composition of surface water vapor at Lhasa, southern Tibetan Plateau

The stable isotopes (δ18O and δD) of water vapor are used to characterize continuous variations in large-scale and boundary-layer atmospheric processes. We presented continuous measurements of δ18O in surface water vapor at Lhasa, southern Tibetan Plateau, from October 2018 to September 2019 to investigate how large-scale and local atmospheric processes influence variations in water vapor δ18O at different time scales. The water vapor δ18O measurements reveal different seasonal characteristics and diurnal patterns. At the seasonal scale, δ18O exhibits a W-shape with two maxima in May–June and October as well as two minima in July–August and February. The diurnal variations in the water vapor δ18O and meteorological data throughout the year present distinct occurrences of maxima and minima during different periods. We found that the significant seasonal variability is mainly associated with the transition between the Indian summer monsoon and the westerlies, which transport distinct moisture to the southern Tibetan Plateau. The local temperature, specific humidity and boundary layer height impact the diurnal variations in water vapor δ18O to some extent with remarkable seasonal differences.publishedVersio

Reconfigurable Intelligent Surface Assisted High-Speed Train Communications: Coverage Performance Analysis and Placement Optimization

Reconfigurable intelligent surface (RIS) emerges as an efficient and promising technology for the next wireless generation networks and has attracted a lot of attention owing to the capability of extending wireless coverage by reflecting signals toward targeted receivers. In this paper, we consider a RIS-assisted high-speed train (HST) communication system to enhance wireless coverage and improve coverage probability. First, coverage performance of the downlink single-input-single-output system is investigated, and the closed-form expression of coverage probability is derived. Moreover, travel distance maximization problem is formulated to facilitate RIS discrete phase design and RIS placement optimization, which is subject to coverage probability constraint. Simulation results validate that better coverage performance and higher travel distance can be achieved with deployment of RIS. The impacts of some key system parameters including transmission power, signal-to-noise ratio threshold, number of RIS elements, number of RIS quantization bits, horizontal distance between base station and RIS, and speed of HST on system performance are investigated. In addition, it is found that RIS can well improve coverage probability with limited power consumption for HST communications.Comment: 14 figures, accepted by IEEE Transactions on Vehicular Technolog

Meteorin-like/Metrnl, a novel secreted protein implicated in inflammation, immunology, and metabolism: A comprehensive review of preclinical and clinical studies

Meteorin-like, also known as Metrnl, Meteorin-β, Subfatin, and Cometin, is a novel secreted protein exerting pleiotropic effects on inflammation, immunology, and metabolism. Earlier research on this hormone focused on regulating energy expenditure and glucose homeostasis. Consequently, several studies attempted to characterize the molecule mechanism of Metrnl in glucose metabolism and obesity-related disorders but reported contradictory clinical results. Recent studies gradually noticed its multiple protective functions in inflammatory immune regulations and cardiometabolic diseases, such as inducing macrophage activation, angiogenesis, tissue remodeling, bone formation, and preventing dyslipidemias. A comprehensive understanding of this novel protein is essential to identify its significance as a potential therapeutic drug or a biomarker of certain diseases. In this review, we present the current knowledge on the physiology of Metrnl and its roles in inflammation, immunology, and metabolism, including animal/cell interventional preclinical studies and human clinical studies. We also describe controversies regarding the data of circulation Metrnl in different disease states to determine its clinical application better

Hsa-miR-196a2 Rs11614913 Polymorphism Contributes to Cancer Susceptibility: Evidence from 15 Case-Control Studies

BACKGROUND: MicroRNAs (miRNAs) are a family of endogenous, small and noncoding RNAs that negatively regulate gene expression by suppressing translation or degrading mRNAs. Recently, many studies investigated the association between hsa-miR-196a2 rs11614913 polymorphism and cancer risk, which showed inconclusive results. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a meta-analysis of 15 studies that included 9,341 cancer cases and 10,569 case-free controls. We assessed the strength of the association, using odds ratios (ORs) with 95% confidence intervals (CIs). Overall, individuals with the TC/CC genotypes were associated with higher cancer risk than those with the TT genotype (OR=1.18, 95% CI=1.03-1.34, P<0.001 for heterogeneity test). In the stratified analyses, we observed that the CC genotype might modulate breast cancer risk (OR=1.11, 95%CI=1.01-1.23, Pheterogeneity=0.210) and lung cancer risk (OR=1.25, 95%CI=1.06-1.46, Pheterogeneity=0.958), comparing with the TC/TT genotype. Moreover, a significantly increased risk was found among Asian populations in a dominant model (TC/CC versus TT, OR=1.24, 95% CI=1.07-1.43, Pheterogeneity=0.006). CONCLUSIONS: These findings supported that hsa-miR-196a2 rs11614913 polymorphism may contribute to the susceptibility of cancers

Uric acid is a biomarker for heart failure, but not therapeutic target: result from a comprehensive meta‐analysis

Abstract Aims This systematic review and meta‐analysis aimed to investigate the association between serum uric acid (SUA) levels and the incidence rate and prognosis of heart failure (HF), as well as the impact of uric acid‐lowering treatment on HF patients. Methods and results PubMed and Embase were searched for original articles reporting on the association between SUA and HF incidence, adverse outcomes, and the effect of uric acid‐lowering treatment in HF patients. Data were pooled using random effects or fixed effects models. Univariable meta‐regression analysis assessed the influence of study characteristics on research outcomes. Statistical analyses were conducted using RevMan software and STATA software version 15.0. Eleven studies on HF incidence and 24 studies on adverse outcomes in HF patients were included. Higher SUA levels were associated with an increased risk of HF (RR: 1.81, 95% CI: 1.53–2.16), all‐cause mortality (RR: 1.44, 95% CI: 1.25–1.66), cardiac death (RR: 1.56, 95% CI: 1.32–1.84), and HF rehospitalization (RR: 2.07, 95% CI: 1.37–3.13) in HF patients. Uric acid‐lowering treatment was found to increase all‐cause mortality in HF patients (RR: 1.15, 95% CI: 1.05–1.25). Conclusions Uric acid is an independent predictor of heart failure occurrence and adverse prognosis. Targeting uric acid lowering as a therapeutic intervention does not improve the prognosis of patients with heart failure. It may not be advisable to use traditional urate‐lowering drugs in young patients with heart failure, and elderly patients should exercise caution when using them

The complete mitochondrial genome of Hybos grossipes (Linnaeus, 1767) (Diptera: Empididae)

The genus Hybos Meigen, 1803 belongs to the subfamily Hybotinae of the family Empididae. Here we report a mitogenome of Hybos grossipes (Linnaeus, 1767) as the new representative of the subfamily Hybotinae. The complete mitogenome is 16,325 bp in total, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. The nucleotide composition is biased toward A and T, accounting for 77.2% of the total. All PCGs start with ATN codons except COI, NAD1, and NAD5, and end with TAA or incomplete stop codon T. The phylogenetic result generated by IQ-Tree based on 13 PGCs showed that the subfamily Hybotinae is monophyletic, and the subfamily Hybotinae is a sister group of the subfamily Ocydromiinae