Toward Improved Parameterizations of Reservoir Operation in Ungauged Basins: A Synergistic Framework Coupling Satellite Remote Sensing, Hydrologic Modeling, and Conceptual Operation Schemes

Assessments of water and energy security over historical and future periods require hydrologic models that can accurately simulate reservoir operations. However, scare reservoir operation data limits the accuracy of current reservoir representations in simulating reservoir behaviors. Furthermore, the reliability of these representations under changing inflow regimes remains unclear, which makes their application for long future planning horizons questionable. To this end, we propose a synergistic framework to predict the release, storage, and hydropower production of ungauged reservoirs (i.e., reservoirs without in-situ inflow, release, storage, and operating rules) by combining remotely sensed reservoir operating patterns and model-simulated reservoir inflow with conceptual reservoir operation schemes within a land surface-hydrologic model. A previously developed reservoir operation scheme is extended with a storage anomaly based calibration approach to accommodate the relatively short time series and large time intervals of remotely sensed data. By setting up controlled experiments in the Yalong River Basin in China, we show that remote sensing can improve the parameter estimation and simulations of ungauged reservoirs for all selected reservoir operation schemes, thereby improving the downstream flood and streamflow simulations. However, most of these schemes show degraded accuracies of reservoir operation simulations under a changing inflow regime, which could lead to unreliable assessments of future water resources and hydropower production. In comparison, our newly extended reservoir operation scheme can be more adaptable to flow regime variations. Our study provides a practical framework for reservoir impact assessments and predictions with the ongoing satellite altimetry projects such as Surface Water and Ocean Topography

Toward improved parameterizations of reservoir operation in ungauged basins: a synergistic framework coupling satellite remote sensing, hydrologic modeling, and conceptual operation schemes

Assessments of water and energy security over historical and future periods require hydrologic models that can accurately simulate reservoir operations. However, scare reservoir operation data limits the accuracy of current reservoir representations in simulating reservoir behaviors. Furthermore, the reliability of these representations under changing inflow regimes remains unclear, which makes their application for long future planning horizons questionable. To this end, we propose a synergistic framework to predict the release, storage, and hydropower production of ungauged reservoirs (i.e., reservoirs without in-situ inflow, release, storage, and operating rules) by combining remotely sensed reservoir operating patterns and model-simulated reservoir inflow with conceptual reservoir operation schemes within a land surface-hydrologic model. A previously developed reservoir operation scheme is extended with a storage anomaly based calibration approach to accommodate the relatively short time series and large time intervals of remotely sensed data. By setting up controlled experiments in the Yalong River Basin in China, we show that remote sensing can improve the parameter estimation and simulations of ungauged reservoirs for all selected reservoir operation schemes, thereby improving the downstream flood and streamflow simulations. However, most of these schemes show degraded accuracies of reservoir operation simulations under a changing inflow regime, which could lead to unreliable assessments of future water resources and hydropower production. In comparison, our newly extended reservoir operation scheme can be more adaptable to flow regime variations. Our study provides a practical framework for reservoir impact assessments and predictions with the ongoing satellite altimetry projects such as Surface Water and Ocean Topography

Superconducting anisotropy and evidence for intrinsic pinning in single crystalline MgB2_2

We examine the superconducting anisotropy $\gamma_c = (m_c / m_{ab})^{1/2}$ of a metallic high-$T_c$ superconductor MgB$_2$ by measuring the magnetic torque of a single crystal. The anisotropy $\gamma_c$ does not depend sensitively on the applied magnetic field at 10 K. We obtain the anisotropy parameter $\gamma_c = 4.31 \pm 0.14$. The torque curve shows the sharp hysteresis peak when the field is applied parallel to the boron layers. This comes from the intrinsic pinning and is experimental evidence for the occurrence of superconductivity in the boron layers.Comment: REVTeX 4, To be published in Physical Review

Association Between Bone Mineral Density, Bone Turnover Markers, and Serum Cholesterol Levels in Type 2 Diabetes

Purpose: The association between bone mineral density (BMD), bone turnover markers, and serum cholesterol in healthy population has already been proved. However, in patients with type 2 diabetes mellitus (T2D), it has not been adequately analyzed. In this study, we investigated the correlation between BMD, bone turnover markers, and serum cholesterol levels in people with T2D.Methods: We enrolled 1,040 men and 735 women with T2D from Zhongshan Hospital between October 2009 and January 2013. Their general condition, history of diseases and medication, serum markers, and BMD data were collected. We used logistic regression analysis to identify the association between serum cholesterol levels and BMD as well as bone turnover markers.Results: In multivariate regression analysis, we observed that in men with T2D, high high-density lipoprotein-cholesterol and total cholesterol levels were significantly associated with low total lumbar, femur neck, and total hip BMD, while low-density lipoprotein-cholesterol level was only inversely associated with total lumbar and femur neck BMD. Total cholesterol and low-density lipoprotein-cholesterol levels were also negatively associated with osteocalcin, procollagen type I N-terminal propeptide, and β-crosslaps. In women with T2D, high-density lipoprotein-cholesterol level was observed to be negatively correlated with total lumbar, femur neck, and total hip BMD, while total cholesterol and low-density lipoprotein-cholesterol levels were only associated with BMD at the total lumbar. Furthermore, total cholesterol was also negatively associated with osteocalcin, procollagen type I N-terminal propeptide, and β-crosslaps; high-density lipoprotein-cholesterol was only related to osteocalcin and parathyroid hormone, while low-density lipoprotein-cholesterol was only related to β-crosslaps in women.Conclusion: Our study suggests a significantly negative correlation between serum cholesterol levels and BMD in both men and women with T2D. The associations between serum cholesterol levels and bone turnover markers were also observed in T2D patients

The workload change and depression among emergency medical staff after the open policy during COVID-19: a cross-sectional survey in Shandong, China

IntroductionIn the middle of December 2022, the Chinese government adjusted the lockdown policy on coronavirus disease 2019 (COVID-19), a large number of infected patients flooded into the emergency department. The emergency medical staff encountered significant working and mental stress while fighting the COVID-19 pandemic. We aimed to investigate the workload change, and the prevalence and associated factors for depression symptoms among emergency medical staff after the policy adjustment.MethodsWe conducted a cross-sectional online survey of emergency medical staff who fought against COVID-19 in Shandong Province during January 16 to 31, 2023. The respondents’ sociodemographic and work information were collected, and they were asked to complete the 9-item Patient Health Questionnaire (PHQ-9) then. Univariate and multivariate logistic regression analyses were applied to identify the potential associated factors for major depression.ResultsNine hundred and sixteen emergency medical personnel from 108 hospitals responded to this survey. The respondents’ weekly working hours (53.65 ± 17.36 vs 49.68 ± 14.84) and monthly night shifts (7.25 ± 3.85 vs 6.80 ± 3.77) increased after the open policy. About 54.3% of the respondents scored more than 10 points on the PHQ-9 standardized test, which is associated with depressive symptoms. In univariate analysis, being doctors, living with family members aged ≤16 or ≥ 65 years old, COVID-19 infection and increased weekly working hours after the open policy were significantly associated with a PHQ-9 score ≥ 10 points. In the multivariate analysis, only increased weekly working hours showed significant association with scoring ≥10 points.ConclusionEmergency medical staff’ workload had increased after the open policy announcement, which was strongly associated with a higher PHQ-9 scores, indicating a very high risk for major depression. Emergency medical staff working as doctors or with an intermediate title from grade-A tertiary hospitals had higher PHQ-9 scores, while COVID-19 infection and weekly working hours of 60 or more after the open policy were associated with higher PHQ-9 scores for those from grade-B tertiary hospitals. Hospital administrators should reinforce the importance of targeted emergency medical staff support during future outbreaks

Chromatin structure characteristics of pre-miRNA genomic sequences

<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are non-coding RNAs with important roles in regulating gene expression. Recent studies indicate that transcription and cleavage of miRNA are coupled, and that chromatin structure may influence miRNA transcription. However, little is known about the relationship between the chromatin structure and cleavage of pre-miRNA from pri-miRNA.</p> <p>Results</p> <p>By analysis of genome-wide nucleosome positioning data sets from human and <it>Caenorhabditis elegans </it>(<it>C. elegans</it>), we found an enrichment of positioned nucleosome on pre-miRNA genomic sequences, which is highly correlated with GC content within pre-miRNA. In addition, obvious enrichments of three histone modifications (H2BK5me1, H3K36me3 and H4K20me1) as well as RNA Polymerase II (RNAPII) were observed on pre-miRNA genomic sequences corresponding to the active-promoter miRNAs and expressed miRNAs.</p> <p>Conclusion</p> <p>Our results revealed the chromatin structure characteristics of pre-miRNA genomic sequences, and implied potential mechanisms that can recognize these characteristics, thus improving pre-miRNA cleavage.</p

Evaluating the inter-annual surplus/deficit dynamic of water retention service in the Yellow River Basin, China

The water retention service (WRS) in the Yellow River Basin is highly critical for the ecological security in northern China. Since the implementation of Grain for Green project during 2000, the changes of WRS and land cover in the Yellow River Basin have not been fully revealed, which limited the knowledge of how anthropogenic activities affected ecological processes. To address the issue, this study chose the water yield-based parameter correction method, and adopted the Sen’s slope test, Mann-Kendall analysis and Hurst index methods, firstly analyzing the inter-annual WRS changes in the Yellow River Basin from 1990 to 2020. Specifically, a new index, Ecosystem Service Deficit Index was proposed to accurately distinguish the deficit/surplus state of WRS. The results of land cover change showed that from 1990 to 2020, forest and grassland were both increasing at the rate of +556.5 km2/yr and +508.4 km2/yr, respectively, and cropland was decreasing with a trend of −965.5 km2/yr. Temporally, WRS was weakening (−0.03 mm/yr) during 1990–2000 but was strengthening in 2000–2020 (+0.08 mm/yr). Spatially, the decreases of WRS mainly occurred in the downstream, with the detectable increases in the headwaters of upstream and the midstream; it is noteworthy that the spatial increases of WRS was unsustainable in the future because Hurst index was less than 0.45 in the study area. The ecosystem service deficit index clearly revealed that WRS experienced a long (at least for 3/4 of study period) deficit period until 2011, and was capable of accurately distinguishing WRS surplus/deficit. The new index can also be applied to assess other ecosystem services. Overall, the integrated roles of the local Grain for Green practices and climate change contributed to the recovery of WRS in the Yellow River Basin, but this recovery may not last. More active human interventions needed to be implemented to mitigate future WRS degradation risks

A study of soil surface characteristics in a small watershed in the hilly, gullied area on the Chinese Loess Plateau

Soil surface characteristics are closely related to soil surface depressional storage, infiltration, runoff generation and soil erosion, especially in highly erodible loess soil. Soil surface random roughness, soil cohesion and aggregate stability are necessary parameters in the Limburg Soil Erosion Model (LISEM) and helpful in developing alternative land-use and conservation strategies. Over a period of 2 years, soil surface characteristics were measured continuously in Danangou, a small catchment in the hilly, gullied loess area in China, with the support of the Erochina project. The results show that soil surface random roughness, soil cohesion and aggregate stability differed significantly between land-use types. Ranking the types on soil roughness during the monitoring period yielded the sequence cropland>orchard and wasteland and fallow land>shrubland>woodland. The corresponding sequence for aggregate stability was approximately wasteland and woodland>cropland and orchard>shrubland>fallow land. Cohesion in the different land-use types in the catchment was smallest for cropland and largest for wasteland. There were no significant differences between croplands with different topographical characteristics. All of these soil surface characteristics showed significant temporal variation over the monitoring period. Temporal variations in roughness for shrubland and woodland over the 2-year period were significantly greater than those for other land-use types. There were also considerable variations in cohesion for shrubland, woodland and wasteland. In 1998, the weighted average values of roughness, aggregate stability and cohesion for the entire catchment were 1.113 cm, 13.6 drops and 0.131 kg/cm2, respectively, with C.V. values of 9.6%, 32.05% and 21.11%. The corresponding values for 1999 were 1.616 cm, 11.52 drops and 0.100 kg/cm2, with C.V. values of 16.0%, 15.41% and 33.33%. The temporal and spatial variations in soil surface characteristics in the catchment should be carefully taken into account in LISEM calibration and validation

Design and simulation investigations on charge transport layers-free in lead-free three absorber layer all-perovskite solar cells

Abstract The multiple absorber layer perovskite solar cells (PSCs) with charge transport layers-free (CTLs-free) have drawn widespread research interest due to their simplified architecture and promising photoelectric characteristics. Under the circumstances, the novel design of CTLs-free inversion PSCs with stable and nontoxic three absorber layers (triple Cs3Bi2I9, single MASnI3, double Cs2TiBr6) as optical-harvester has been numerically simulated by utilizing wxAMPS simulation software and achieved high power conversion efficiency (PCE) of 14.8834%. This is owing to the innovative architecture of PSCs favors efficient transport and extraction of more holes and the slender band gap MASnI3 extends the absorption spectrum to the near-infrared periphery compared with the two absorber layers architecture of PSCs. Moreover, the performance of the device with p-type-Cs3Bi2I9/p-type-MASnI3/n-type-Cs2TiBr6 architecture is superior to the one with the p-type-Cs3Bi2I9/n-type-MASnI3/n-type-Cs2TiBr6 architecture due to less carrier recombination and higher carrier life time inside the absorber layers. The simulation results reveal that Cs2TiF6 double perovskite material stands out as the best alternative. Additionally, an excellent PCE of 21.4530% can be obtained with the thicker MASnI3 absorber layer thickness (0.4 µm). Lastly, the highest-performance photovoltaic devices (28.6193%) can be created with the optimized perovskite doping density of around E15 cm3 (Cs3Bi2I9), E18 cm3 (MASnI3), and 1.5E19 cm3 (Cs2TiBr6). This work manifests that the proposed CTLs-free PSCs with multi-absorber layers shall be a relevant reference for forward applications in electro-optical and optoelectronic devices. Graphical Abstrac