Analysis of long-term terrestrial water storage variations in Yangtze River basin

In this study, we analyze 32 yr of TWS data obtained from Interim Reanalysis Data (ERA-Interim) and Noah model from Global Land Data Assimilation System (GLDAS-Noah) for the period between 1979 and 2010. The accuracy of these datasets is validated against 26 yr (1979–2004) of runoff dataset from Yichang gauging station and compared to 32 yr of independent precipitation data obtained from Global Precipitation Climatology Centre Full Data Reanalysis Version 6 (GPCC) and NOAA's PRECipitation REConstruction over Land (PREC/L). Spatial and temporal analysis of the TWS data shows that TWS in the Yangtze River basin is decreasing significantly since the year 1998. The driest period of the basin is noted from 2005 to 2010, especially in the middle and lower Yangtze reaches. The TWS changed abruptly into persistently high negative anomalies in the middle and lower Yangtze reaches in 2004. From both basin and annual perspectives, 2006 is detected as the major inflection point at which the system exhibits a persistent decrease in TWS. Comparing these TWS trends to independent precipitation datasets shows that the recent decrease in TWS can mainly be attributed to a decrease in precipitation amount. Our finding is based on observation and modeling data sets and confirms previous results based on gauging station datasets

Effects of Roughness Length Parameterizations on Regional-Scale Land Surface Modeling of Alpine Grasslands in the Yangtze River Basin

Abstract Current land surface models (LSMs) tend to largely underestimate the daytime land surface temperature for high-altitude regions. This is partly because of underestimation of heat transfer resistance, which may be resolved through adequate parameterization of roughness lengths for momentum and heat transfer. In this paper, the regional-scale effects of the roughness length parameterizations for alpine grasslands are addressed and the performance of the Noah LSM using the updated roughness lengths compared to the original ones is assessed. The simulations were verified with various satellite products and validated with ground-based observations. More specifically, four experimental setups were designed using two roughness length schemes with two different parameterizations of (original and updated). These experiments were conducted in the source region of the Yangtze River during the period 2005–10 using the Noah LSM. The results show that the updated parameterizations of roughness lengths reduce the mean biases of the simulated daytime in spring, autumn, and winter by up to 2.7 K, whereas larger warm biases are produced in summer. Moreover, model efficiency coefficients (Nash–Sutcliffe) of the monthly runoff results are improved by up to 26.3% when using the updated roughness parameterizations. In addition, the spatial effects of the roughness length parameterizations on the simulations are discussed. This study stresses the importance of proper parameterizations of and for LSMs and highlights the need for regional adaptation of the and values.</jats:p

Dysnatremia is associated with increased risk of all-cause mortality within 365 days post-discharge in patients with atrial fibrillation without heart failure: A prospective cohort study

Aim: The aim of this study is to evaluate the association between serum sodium concentrations at hospital admission and all-cause mortality within 365 days post-discharge in patients with atrial fibrillation (AF) without heart failure (HF). Methods: The prospective cohort study enrolled 1,446 patients with AF without HF between November 2018 and October 2020. A follow-up was performed 30, 90, 180, and 365 days after enrollment through outpatient visits or telephone interviews. All-cause mortality was estimated in three groups according to serum sodium concentrations: hyponatremia ( \u3c 135 mmol/L), normonatremia (135 – 145 mmol/L), and hypernatremia ( \u3e 145 mmol/L). We estimated the risk of all-cause mortalities using univariable and multivariable Cox proportional hazards models with normonatremia as the reference. Results: The all-cause mortalities of hyponatremia, normonatremia, and hypernatremia were 20.6, 9.4, and 33.3 % within 365 days post-discharge, respectively. In the univariable analysis, hyponatremia (HR: 2.19, CI 1.5 – 3.2) and hypernatremia (HR: 4.03, CI 2.32 – 7.02) increased the risk of all-cause mortality. The HRs for hyponatremia and hypernatremia were 1.55 (CI 1.05 – 2.28) and 2.55 (CI 1.45 – 4.46) after adjustment for age, diabetes mellitus, loop diuretics, antisterone, antiplatelet drugs, and anticoagulants in the patients with AF without HF. The association between serum sodium concentrations and the HRs of all-cause mortality was U-shaped. Conclusion: Dysnatremia at hospital admission was an independent factor for all-cause mortality in patients with AF without HF within 365 days post-discharge

Intramolecular Folding in Human ILPR Fragment with Three C-Rich Repeats

Enrichment of four tandem repeats of guanine (G) rich and cytosine (C) rich sequences in functionally important regions of human genome forebodes the biological implications of four-stranded DNA structures, such as G-quadruplex and i-motif, that can form in these sequences. However, there have been few reports on the intramolecular formation of non-B DNA structures in less than four tandem repeats of G or C rich sequences. Here, using mechanical unfolding at the single-molecule level, electrophoretic mobility shift assay (EMSA), circular dichroism (CD), and ultraviolet (UV) spectroscopy, we report an intramolecularly folded non-B DNA structure in three tandem cytosine rich repeats, 5'-TGTC4ACAC4TGTC4ACA (ILPR-I3), in the human insulin linked polymorphic region (ILPR). The thermal denaturation analyses of the sequences with systematic C to T mutations have suggested that the structure is linchpinned by a stack of hemiprotonated cytosine pairs between two terminal C4 tracts. Mechanical unfolding and Br2 footprinting experiments on a mixture of the ILPR-I3 and a 5′-C4TGT fragment have further indicated that the structure serves as a building block for intermolecular i-motif formation. The existence of such a conformation under acidic or neutral pH complies with the strand-by-strand folding pathway of ILPR i-motif structures

Risk spillovers in Chinese production network: A supply-side shock perspective

Abstract Highly interconnected production network exists in one economy, and it is crucial to investigate how and why supply-side shocks spread across industries via the production network and cause systemic risks in the real sector. Based on input-output framework, this paper designed a model to simulate the propagation of risk spillovers along the production network given supply-side shocks. This paper defined the systemically important industries (SIIs) and systemically vulnerable industries (SVIs) according to the degree and direction of risk spillovers. Simulation results show that risk spillovers spread among industries via the production network, leading to systemic risk in the real sector. This paper also classified the important risk spillover paths “SVIs → SIIs → SVIs” in the model for risk regulation and prevention and identified 75 risk spillover paths and 9 closed-loop paths in 2018. Furthermore, key factors of systemic importance (vulnerability) included input-output relationships and production network centrality. This paper provides a scientific basis to strengthen the risk supervision of the real sector based on the supply chain

Physiological responses of typical wetland plants following flooding process - from an eco-hydrological model perspective

Anaerobics increase resistance to gas transport and microbial activity in flooded soils. This may result in the presence of aerenchyma in the roots of some wetland plants. Increased aerenchyma airspaces enable oxygen to be transported from the above-ground plant parts to the submerged roots and rhizosphere. Nevertheless, there is still a lack of studies linking field experiments and eco-hydrological modeling to the parameterization of the physiological responses of typical wetland plant species to natural flooding events. Furthermore, from the modeling perspective, the contribution of aerenchyma was not sufficiently considered. The goal of this study was to develop and apply an eco-hydrological model capable of simulating various patterns of plant physiological responses to natural flooding events based on key processes of root oxygen diffusion and aerenchyma functioning in a variably-saturated wetland soil environment. Eco-hydrological experiments were conducted accordingly, with surface water level, root-zone soil water content, soil temperature, leaf net photosynthesis rate and root morphology monitored simultaneously in situ at a site dominated by meadow species Deyeuxia angustifolia (Kom.) Y. L. Chang and invaded shrub species Salix rosmarinifolia Linn. var. brachypoda (Trautv.et Mey.) Y.L. Chou in a typical natural floodplain wetland. The results are as follows: (1) Root oxygen respiration rates are strongly correlated with leaf net photosynthesis rates of the two plant types, particularly under flooding conditions during the growing season; (2) Meadow species with a preference for wet microhabitats has a competitive advantage over first-year invading shrub species during flooding events; and (3) an aerenchyma sub-model could improve the eco-hydrological model’s accuracy in capturing plant physiological responses. These findings have the potential to contribute to the management of wetland and its restorations

Denitrification-caused Suppression of Soluble Microbial Products (SMP) in MBRs used for Biological Nitrogen Removal

SignificanceThe strategies for reducing SMP-caused membrane fouling are essential for MBR sustainable operation. Comparing the bioprocesses with and without denitrification, we found that the specific yield coefficients of polysaccharides (PS) and proteins (PN) in SMP existing denitrification were significantly lower than those without denitrification. In addition, the freshly produced PS and PN from extracelluar polymeric substances (EPS) could be biodegraded and utilized by denitrifers. These findings indicated that biological denitrification was an important mechanism to reduce SMP and MBR fouling. (c) 2013 American Institute of Chemical Engineers AIChE J, 59: 3569-3573, 201

Analysis of Magnetic Field Characteristics of a Giant Magnetostrictive Actuator with a Semi-Closed Magnetic Circuit

The internal magnetic field characteristics of giant magnetostrictive actuators have an important influence on their output performance. Aiming at the deficiency of current scholars&rsquo; research, based on the electromagnetic theory and finite element method, this paper analyzes the magnetic field intensity on a giant magnetostrictive cylinder by using COMSOL Multiphysics software. Considering the inhomogeneity of magnetic field intensity along the radial direction of giant magnetostrictive cylinders, a new averaging method is introduced to calculate the magnetic field intensity in the axial section of the cylinder. The influence of the magnetic permeability of the displacement conversion mechanism (shell) and the size of the air gap inside the device on the magnetic field intensity of the giant magnetostrictive cylinder are analyzed. The prototype of the actuator is manufactured, and the correctness and accuracy of the simulation data are verified by experiments. In order to make the magnetic field on the cylinder strong and uniform, the displacement conversion mechanism and the shell should be made of low permeability and high permeability materials, respectively, and the air gap size should be reduced as much as possible under the condition of meeting the size requirement of the actuator pre-tightening force applying device