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Lake level changes are critical indicators of hydrological balance and climate change, yet long‐term monthly lake level reconstruction is challenging with incomplete or short‐term data. Data‐driven models, while promising, struggle with nonstationary lake level changes and complex dependencies on meteorological factors, limiting their applicability. Here, we introduce the Hydroformer, a frequency domain enhanced multi‐attention Transformer model designed for monthly lake level reconstruction, utilizing reanalysis data. This model features two innovative mechanisms: (a) Frequency‐Enhanced Attention (FEA) for capturing long‐term temporal dependence, and (b) Causality‐based Cross‐dimensional Attention (CCA) to elucidate how specific meteorological factors influence lake level. Seasonal and trend patterns of catchment meteorological factors and lake level are initially identified by a time series decomposition block, then independently learned and refined within the model. Tested across 50 lakes globally, the Hydroformer excelled in reconstruction periods ranging from half to three times the training‐test length. The model exhibited good performance even when training data missing rates were below 50%, particularly in lakes with significant seasonal fluctuations. The Hydroformer demonstrated robust generalization across lakes of varying sizes, from 10.11 to 18,135 km2, with median values for R2, MAE, MSE, and RMSE at 0.813, 0.313, 0.215, and 0.4, respectively. Furthermore, the Hydroformer outperformed data‐driven models, improving MSE by 29.2% and MAE by 24.4% compared to the next best model, the FEDformer. Our method proposes a novel approach for reconstructing long‐term water level changes and managing lake resources under climate change. Plain Language Summary: Lake water levels, as key indicators of hydrologic dynamics and catchment balance, are vital for understanding climate impacts and managing water resources. However, the lack of continuous measurements for most global lakes, combined with the inability of traditional data‐driven models to effectively decipher complex interactions with catchment hydrological processes, leads to significant gaps in generalizability, accuracy, and reconstructive length. Given these limitations, accurate monthly reconstructions of lake level remain a persistent challenge. To address this, we develop Hydroformer, an innovative frequency domain enhanced multi‐attention Transformer model, utilizing reanalysis data for monthly lake level reconstruction. It employs two innovative attention mechanisms: Frequency‐Enhanced Attention for capturing long‐term temporal dependencies and Causality‐based Cross‐dimensional Attention for cross‐dimensional causal dependencies between catchment meteorological factors and lake level. Through a decomposition block, the model efficiently recognizes and refines inherent seasonal and trend patterns, leading to a comprehensive understanding of lake behaviors. Through testing on 50 global lakes, the Hydroformer has exhibited exceptional performance in reconstructing water levels for lakes ranging from 10.11 to 18,135 km2, adeptly handling short‐term, long‐term, and varying proportions of data gaps. It notably outperforms supervised data‐driven models. This positions it as a vital instrument for monthly lake level reconstruction, showcasing the power of integrating advanced artificial intelligence techniques in hydrological modeling. Key Points: A novel frequency domain enhanced multi‐attention Transformer model, Hydroformer, has been built for reconstructing monthly lake level using reanalysis dataThe model accurately extends reconstructions 2–3 times the training data length, excelling with less than 50% missing training dataHydroformer surpasses advanced AI‐based models, improving MSE and MAE by over 20% and demonstrating strong generalization across lakes of varying sizes [ABSTRACT FROM AUTHOR]

Understanding the risks of planktonic algal proliferation and its environmental causes is crucial for protecting water quality and controlling ecological risks. Reservoirs, due to the characteristics of slow flow rates and long hydraulic retention times, are more prone to eutrophication and algal proliferation. Chlorophyll-a (Chl-a) serves as an indicator of planktonic algal biomass. Exploring the intricate interactions and driving mechanisms between Chl-a and the water environment, and the potential risks of algal blooms, is crucial for ensuring the ecological safety of reservoirs and the health of water users. This study focused on the Danjiangkou Reservoir (DJKR), the core water source of the Middle Route of the South-to-North Water Diversion Project of China (MRSNWDPC). The multivariate statistical methods and structural equation modeling were used to explore the relationships between chlorophyll-a (Chl-a) contents and water quality factors and understand the driving mechanisms affecting Chl-a variations. The Copula function and Bayesian theory were combined to analyze the risk of changes in Chl-a concentrations at Taocha (TC) station, which is the core water source intake point of the MRSNWDPC. The results showed that the factors driving planktonic algal proliferation were spatially heterogeneous. The main factors affecting Chl-a concentrations in Dan Reservoir (DR) were water physicochemical factors (water temperature, dissolved oxygen, pH value, and turbidity) with a total contribution rate of 60.18%, whereas those in Han Reservoir (HR) were nutrient factors (total nitrogen, total phosphorus, and ammonia nitrogen) with a total contribution rate of 73.58%. In TC, the main factors were water physicochemical factors (turbidity, pH, and water temperature) and nutrient factors (total phosphorus) with total contribution rates of 39.76% and 45.78%, respectively. When Chl-a concentrations in other areas of the DJKR ranged from the minimum to the uppermost quartile, the probabilities that Chl-a concentrations at the TC station exceeded 3.4 μg/L (the benchmark value of Chl-a for lakes in the central-eastern lake area of China) owing to the influence of these areas were all less than 10%. Thus, the risk of planktonic algal proliferation at the MRSNWDPC intake point is low. This study developed an integrated framework to investigate spatiotemporal changes in algal proliferation and their driving factors in reservoirs, which can be used to support water quality management in mega hydro projects. [ABSTRACT FROM AUTHOR]

In mammals, global passive demethylation contributes to epigenetic reprogramming during early embryonic development. At this stage, the majority of DNA-methyltransferase 1 (DNMT1) protein is excluded from nucleus, which is considered the primary cause. However, whether the remaining nuclear activity of DNMT1 is regulated by additional mechanisms is unclear. Here, we report that nuclear DNMT1 abundance is finetuned through proteasomal degradation in mouse zygotes. We identify a maternal factor, Pramel15, which targets DNMT1 for degradation via Cullin-RING E3 ligases. Loss of Pramel15 elevates DNMT1 levels in the zygote pronuclei, impairs zygotic DNA demethylation, and causes a stochastic gain of DNA methylation in early embryos. Thus, Pramel15 can modulate the residual level of DNMT1 in the nucleus during zygotic DNA replication, thereby ensuring efficient DNA methylation reprogramming in early embryos. Epigenetic reprogramming involves global loss of DNA methylation, but how this is regulated is not completely understood. Here, Tan et al. run a reverse genetic screen and report that nuclear DNMT1 is finetuned by maternal factor Pramel15 through proteasomal degradation in mouse zygotes. [ABSTRACT FROM AUTHOR]

The integration of terrestrial- and satellite-based quantum key distribution (QKD) experiments has markedly advanced global-scale quantum networks, showcasing the growing maturity of quantum technologies. Notably, the use of unmanned aerial vehicles (UAVs) as relay nodes has emerged as a promising method to overcome the inherent limitations of fiber-based and low-Earth orbit (LEO) satellite connections. This paper introduces a protocol for measurement-device-independent QKD (MDI-QKD) using photon orbital angular momentum (OAM) encoding, with UAVs as relay platforms. Leveraging UAV mobility, the protocol establishes a secure and efficient link, mitigating threats from untrusted UAVs. Photon OAM encoding addresses reference frame alignment issues exacerbated by UAV jitter. A comprehensive analysis of atmospheric turbulence, state-dependent diffraction (SDD), weather visibility, and pointing errors on free-space OAM-state transmission systems was conducted. This analysis elucidates the relationship between the key generation rate and propagation distance for the proposed protocol. Results indicate that considering SDD significantly decreases the key rate, halving previous data results. Furthermore, the study identifies a maximum channel loss capacity of 26 dB for the UAV relay platform. This result is pivotal in setting realistic parameters for the deployment of UAV-based quantum communications and lays the foundation for practical implementation strategies in the field. [ABSTRACT FROM AUTHOR]

Water cycle process will deeply affect water vapour isotope composition, in addition to the evaporation and condensation processes, the exchange process is also a crucial process that influences isotopic variations. To explore the mechanism of isotope exchange under isothermal saturation conditions, we developed an isotope exchange calculation equation for water vapour (IECEWV) based on the conservation of exchange quantity and conducted indoor trials with 100 control groups to validate the IECEWV. The experimental findings demonstrated that the isotopic values of water vapour exhibited enrichment, depletion, and stabilisation during the exchange process when the droplet size first increased and then stabilised, because of the interaction between the exchange state, isotopic gradients, and specific surface area of the droplets according to IECEWV. The variation trend of IECEWV calculated isotopes in water vapour was consistent with experimental value, with average maximum relative errors of 1.66 % for δ 2H and 3.19 % for δ 18O, and IECEWV analysis further indicates isotopes exchange can lead to the hydrogen and oxygen isotope line of water vapour deviate from the origin. Furthermore, the linear relationship between hydrogen and oxygen isotopes in water vapour after exchanged can be characterised by linear clusters with the same slope, the d -excess of water vapour remains essentially constant. Future studies may combine the IECEWV with the Rayleigh fractionation model to explore the coordinated changes in precipitation and atmospheric water vapour isotopes. [ABSTRACT FROM AUTHOR]

Knowledge of the quantitative importance of the moisture transport pathways and mutual moisture exchange of the source regions of the Yangtze (SYZR) and Yellow (SYR) rivers' basins, the adjacent origins of China's two longest rivers, can provide insights into the regional atmospheric branch of the hydrological cycle over the source regions. The method with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and a Lagrangian moisture source diagnostic to identify the major moisture transport pathways quantifies their importance to two types of daily precipitation events—daily precipitation more than 10 mm (PM) events and daily precipitation less than 10 mm (PL) events—for the two rivers' regions during the summer (June–August, 1986–2015) and finds the characteristics of mutual moisture exchange. The results indicated that both the Bay of Bengal group pathway and the northwest China group pathway play significant roles in PM and PL events over the SYZR, contributing 41.87% and 39.12% to PM events and 41.33% and 33.16% to PL events, respectively. The SYR has five main moisture path groups; the Bay of Bengal group pathway, the northwest China group pathway, and the southeast China group pathway play significant roles in PM and PL events over the SYR, contributing 32.34%, 23.28%, and 34.36% to PM events and 34.84%, 36.18%, and 19.83% to PL events, respectively. The volume of moisture passing from the SYZR to the SYR is approximately 60 times that of the reverse, constituting about 6.9% of the total moisture released in SYR precipitation. It is worth noting that the moisture release was concentrated in the nearer west group pathway, and the main moisture uptake locations were beyond the source region of the two rivers (remote sources) in the PM events. The aggregate moisture release high-frequency moisture transport path groups are found in the southeastern parts of Zhiduo County and the southeast of Zaduo County. [ABSTRACT FROM AUTHOR]

As the longest tributary of the Yangtze River, the Hanjiang River has been a "lifeline" for the "Yangtze River Economic Belt of China". The water quality of the middle and lower reaches of the Hanjiang River (MLHR) has received considerable attention due to environmental degradation, increasing population, and water diversion project operations during the past decade. In this study, 16 water quality parameters from 14 national water quality monitoring stations along the MLHR were collected monthly from January 2021 to December 2022. Water quality index (WQI) methods coupling multivariate statistical techniques, e.g., seasonal Mann-Kendall test (SKT) and Mantel's test, were applied to analyze and evaluate the spatiotemporal variations of water quality under different environmental and hydrological conditions. The Hazard Quotients (HQs) were used to assess the non-carcinogenic and carcinogenic risk for adults and children via ingestion and dermal pathways. The results showed that the overall water quality in the MLHR was classified as "excellent", with the average WQI higher than "91", and each single water quality indicator met Class I or Class II surface water quality standards of China. Ammonia (NH3-N), Total phosphorus (TP), Permanganate (CODMn), pH, and Arsenic (As) were significantly correlated with water level variations. CODMn and TP were decisive in explaining the WQI variations of the MLHR. NH3-N, water temperature, pH, and dissolved oxygen were key parameters for explaining WQI variations in most regions of the MLHR. As, Cadmium (Cd), and Chromium (Cr) presented potential health risks in the MLHR and should warrant close monitoring due to their significant health implications. Due to the continuous construction and operation of cascade hydro-projects, the synchronous monitoring of water quality and hydrological data of the MLHR should be conducted in the future. This study provides a scientific reference for managing water quality in the MLHR and similar natural riverine water bodies. [ABSTRACT FROM AUTHOR]

The study on the impact of consumer purchase intention on luxury goods has received widespread attention from the academic community. This study collected research data in Guilin, China, through questionnaire survey, and conducted an empirical study on the influencing factors of luxury consumers' purchase intention. The results show: The price level of luxury goods has a positive impact on consumers' face perception, while the positive impact of price level on expected regret has not been verified. Consumer's face perception has positive and negative effects on consumers' expected regret and consumers' purchase intention respectively. Consumer's downward expected regret and consumer's upward expected regret have different effects on consumers' purchase intention. Consumers' face perception and expected regret play a mediating effect in the research of influence relationship. This study is conducive to a better analysis of the psychology and behavior of Chinese luxury consumers, enriching the theoretical connotation of consumer psychology, and promoting the healthy development of the luxury goods industry. [ABSTRACT FROM AUTHOR]

In the context of climate change, precipitation and runoff in the arid inland basins of northwest China have undergone significant changes. The Qaidam Basin (QB) is a typical highland arid inland area. Understanding the spatial and temporal variations in surface water and groundwater chemistry and isotopes, as well as their causes, is crucial for future water resource management and ecological protection. Samples of river, lake, and groundwater, as well as others, were collected and tested in five typical watersheds in the summer and winter. The hydrochemistry and isotopic spatiotemporal differences in various water bodies were studied using the significant difference method, water vapor flux models, hydrochemistry, isotopes, and other methods for cause analyses. The results indicate the following: (1) There are differences in hydrochemistry between the southern and northern basins because the southern basin is more influenced by the dissolution of salt rocks and evaporation, whereas the northern basin is mainly affected by carbonate weathering. (2) The enrichment of δD and δ18O in the northern basin gradually increases from west to east, while in the southern basin, it is the opposite. This is because the southern basin receives a larger contribution of water vapor from the mid-latitude westerlies, while the northern basin primarily relies on local evaporation as its water vapor source. (3) Significant differences are observed in the total dissolved solids (TDS) and hydrochemical types of river water and groundwater between the summer and winter due to higher rates of rock weathering and evaporation in the summer. (4) The more pronounced seasonal differences in hydrogen and oxygen stable isotopes in the southern basin are due to higher rates of internal water vapor circulation in the summer. (5) The similarity in characteristics between river water and groundwater is the result of strong exchanges between river water and groundwater from piedmonts to terminals. The spatiotemporal heterogeneity of terminal lakes is attributed to the accumulation of salts and groundwater replenishment from other sources. [ABSTRACT FROM AUTHOR]

The continuous impact of COVID-19 on aquatic environments has attracted considerable attention, primarily focusing on short-term water quality effects during lockdown, while studies on changes following the lifting of restrictions are relatively limited. Following adjustments to China's pandemic public policy in December 2022, the effects on water quality and nutrient status in lakes and reservoirs remain unclear. In this study, we collected national environmental monitoring data comprising 15 indicators of water quality, meteorology, soil, and economic factors, from 86 lakes and reservoirs across China between March 2021 and December 2023. Total nitrogen (TN), total phosphorus (TP), the mass TN/TP ratio (TN/TP), and ammonia-nitrogen (NH 3 -N) were selected as representative nutrient indicators. The water quality index (WQI) and multivariate statistical techniques were employed to comprehensively assess national water quality and identify the drivers of nutrient variations in sub-regions. The results show that during the monitoring period from 2021 to 2023, Chinese national water quality consistently fell within the 'good (61-80)' or 'excellent (81-100)' categories, with the lowest water quality observed in the summer of each year. The summer of 2021 recorded the lowest WQI value among all seasons at 75.01. Following the elimination of the COVID-19 epidemic public lockdown policy, concentrations of TN, TP, and NH 3 -N declined. These findings indicate a general improvement in the water quality of lakes and reservoirs nationwide. Mantel test and multiple stepwise linear regression models revealed significant correlations between nutrients and human activity indicators in central, eastern, and northern China. In northern China, TP showed a significant positive correlation with GDP (0.2 < Mantel's r < 0.5, P < 0.05), with the beta value increasing from 0.27 to 0.38 after the elimination of the COVID-19 epidemic public lockdown policy. In these regions, the influence of rainfall, wind speed, NDVI, surface soil moisture, and water temperature on nutrients shifted from significant to insignificant effects after the elimination of the COVID-19 epidemic public lockdown policy, indicating that human activities have overshadowed natural factors. This study examines the water quality and nutrient status of lakes and reservoirs in China after the elimination of the COVID-19 epidemic public lockdown policy, highlighting the long-term impacts and spatial variations of the pandemic. These findings will inform environmental governance and promote sustainable water resource management in the post-pandemic era., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)