22 research outputs found
Model estimates of China's terrestrial water storage variation due to reservoir operation
Understanding the role of reservoirs in the terrestrial water cycle is critical to support the sustainable management of water resources especially for China where reservoirs have been extensively built nationwide. However, this has been a scientific challenge due to the limited availability of continuous, long-term reservoir operation records at large scales, and a process-based modeling tool to accurately depict reservoirs as part of the terrestrial water cycle is still lacking. Here, we develop a continental-scale land surface-hydrologic model over the mainland China by explicitly representing 3,547 reservoirs in the model with a calibration-free conceptual operation scheme for ungauged reservoirs and a hydrodynamically based two-way coupled scheme. The model is spatially calibrated and then extensively validated against streamflow observations, reservoir storage observations and GRACE-based terrestrial water storage anomalies. A 30-year simulation is then performed to quantify the seasonal dynamics of Chinaâs reservoir water storage (RWS) and its role in China\u27s terrestrial water storage (TWS) over recent decades. We estimate that, over a seasonal cycle, China\u27s RWS variation is 15%, 16%, and 25% of TWS variation during 1981â1990, 1991â2000, and 2001â2010, respectively, and one-fifth of Chinaâs reservoir capacity are effectively used annually. In most regions, reservoirs play a growing role in modulating the water cycle over time. Despite that, an estimated 80 million people have faced increasing water resources challenges in the past decades due to the significantly weakened reservoir regulation of the water cycle. Our approaches and findings could help the government better address the water security challenges under environmental changes
Layout Optimization of Logistics and Warehouse Land Based on a Multi-Objective Genetic AlgorithmâTaking Wuhan City as an Example
With the rapid development of the logistics industry, the demand for logistics activities is increasing significantly. Concurrently, growing urbanization is causing the space for logistics and warehousing to become limited. Thus, more and more attention is being paid to the planning and construction of logistics facilities. However, due to spatiotemporal trajectory data (such as truck GPS data) being used less often in planning, the method of quantitative analysis for freight spatiotemporal activity is limited. Thus, the spatial layout of logistics and warehousing land does not match the current demand very well. In addition, it is necessary to consider the interactive relationship with the urban built environment in the process of optimizing layout, in order to comprehensively balance the spatial coupling with the functions of housing, transportation, industry, and so on. Therefore, the layout of logistics and warehouse land could be treated as a multi-objective optimization problem. This study aims to establish a model for logistics and warehouse land layout optimization to achieve a supplyâdemand matching. The proposed model comprehensively considers economic benefits, time benefits, cost benefits, environmental benefits, and other factors with freight GPS data, land-use data, transportation network data, and other multi-source data. A genetic algorithm is built to solve the model. Finally, this study takes the Wuhan urban development area as an example to practice the proposed method in three scenarios in order to verify its effectiveness. The results show that the optimization model solves the problem of mismatch between the supply and demand of logistics spaces to a certain extent, demonstrating the efficiency and scientificity of the optimization solutions. Based on the results of the three scenarios, it is proven that freight activities could effectively enhance the scientific validity of the optimization solution and the proposed model could optimize layouts under different scenario requirements. In summary, this study provides a practical and effective tool for logistics- and warehouse-land layout evaluation and optimization for urban planners and administrators
Biological Characteristics of Liza haematocheila in the Shallow Coastal Waters of the Yellow River Estuary
In recent years, fishery species have decreased in size and quality in the Yellow River estuary seas due to the effects of climate change and human activities, such as water and sediment regulation of the Yellow River, overfishing, and sewage discharge, among others. At the same time, the fishery resource structure has changed greatly: Small-sized fish with low value, shrimps and crabs became the main catches. To conserve natural resources and maintain local fishery harvests, conservation efforts such as stock enhancement and fishing quotas have been employed. Research on the biological characteristics of important fish can provide a scientific basis for the rational utilization and stock enhancement of fishery resources in the future, and it can also offer support for making relevant fishery policies.Liza haematocheila is an economically important fishery species in the Yellow River estuary and mainly feeds on zooplankton, phytoplankton, and organic detritus, which limits eutrophication and promotes energy and carbon cycling at the ecosystem level. The species plays an important role in ecosystem function and the maintenance of biodiversity. This study investigated the biological characteristics of L. haematocheila to provide a scientific basis for its conservation and rational utilization in the Yellow River estuary. Furthermore, it can provide basic biological data for the study of ecological restoration in the Yellow River estuary.This study evaluated the distribution of body length and weight, the relationship between body length and weight, reproduction, growth, death, and development. All of the analyses were based on sampling data from set nets between April and November 2020.The body length range of L. haematocheila was 45~460 mm, the average body length was 149 mm, and the modal body length range was 55~185 mm. The body weight range was 2~1100 g, the average body weight was 83 g, and the modal body weight range was 2~80 g. Both the average body length and body weight were the highest in May and the lowest in September. Overall, small individuals were the most common, and individuals with a body length of less than 200 mm accounted for more than 78%. Analysis of variance showed significant monthly differences in both average body length and weight of L. haematocheila. The relationship between body length and body weight showed a strong correlation within and between months [W=3.17Ă10â5L2.82, (R2=0.980 5, n=984)]. The growth of L. haematocheila was negatively allometric, with the growth of body length being faster than that of body weight.The body condition of L. haematocheila decreased with time, though it increased in July and fluctuated with a downward trend from July to November. The nadir body condition was observed in June (1.102±0.173) and the peak body condition was observed in July (1.535±0.467).The rate of gonadal development varied from month to month, and the proportion of individuals who did not reach gonadal maturity was large, with an undeveloped gonad proportion of more than 50% per month. There was a peak spawning period from April to May.The growth curve of L. haematocheila was fitted, and its growth parameters were estimated using the ELEFAN method. The total death coefficient of the population was estimated using a length-converted catch curve, the natural death coefficient was estimated using the empirical formula of Pauly, and the population development rate was calculated. The results indicated that the asymptotic length (Lâ) of L. haematocheila was 608 mm, the growth rate (K) was 0.31 aâ1, total death coefficient (Z) was 1.42 aâ1, natural death coefficient (M) was 0.51 aâ1, fishing death coefficient (F) was 0.91 aâ1, and its population development rate (E) was 0.64. The L. haematocheila resource was overfished in the shallow coastal waters of the Yellow River estuary, and its open fishing length (L50) was only 57.4 mm in this production survey.Fixed-net harvesting led to overfishing in the Yellow River estuary from April to November 2020, with juvenile fish and supplementary stocks experiencing the greatest impact. We should reconsider the management strategies for L. haematocheila in the Yellow River estuary, and promote stock enhancement at the same time. Artificial propagation technology for L. haematocheila should be considered for supplementing L. haematocheila in the Yellow River estuary seas. Research on the release time, release of krill size, population characteristics, growth, and development should be addressed to provide an informed and scientific basis for stock enhancement
Seasonal Biodiversity of Fishery Resources by Set Net in the Intertidal Zone to the Southwest of the Yellow River Estuary
The Yellow River estuary is one of the three largest estuaries along the coastal waters of China, along with the Yangtze and Pearl River estuaries. Its adjacent seawaters are rich in biological resources, with abundant fish habitat, spawning grounds, and migration channels in the Bohai Sea and the Yellow Sea. However, as the waters are too shallow for a survey ship, data was insufficient for research in the intertidal zone of the salt and freshwater interchange. Instead, by interviewing and analyzing the daily catches by the set net of the local fishermen, this study explored the fishery biodiversity in the intertidal zone of the Yellow River estuary from April to November 2020. Yellow River estuary is rich in fishery resources, especially small fishery organisms and fish recruitment stocks. There were monthly variations in the dominant species composition and biodiversity index. A total of 61 species were recorded, most of which were fish and crustaceans. The diversity, evenness, and species richness index increased in summer (July and August) and decreased in autumn (October and November). By cluster analysis of the species compositions, the surveyed months can be divided into two groups: May to September, and October to November. Lateolabrax maculatus and Liza haematocheila were the most common and dominant species in all surveyed months. The main contributors to the catch of each month were: snails from April to July, snails and fish in August, fish in September, and crabs from October to November. Catches by the set net were mainly composed of individuals with body mass < 2 g from April to September. From body mass-frequency distributions, fish with body mass < 10 g were the main contributors to total catches from April to September. The mean body mass of fish in all surveyed months was 13 g/ind.. The dominant fish species with body mass with < 20 g were: Gobioidei in April; L. maculatus in May; Konosirus punctatus in June; Pennahia argentata, Gobioidei, and L. haematocheila in June to August; and Sardinella zunasi, Thrissa kammalensis, T. mystax, Sillago sihama, Tylosurus melanotus, Gobioidei, and L. haematocheila in September. From the above results, the local set net fishery survey proved to be an effective method of collecting fishery data in the intertidal zone and can be incorporated in studies considering the distribution of fishery resources and breeding grounds in the seawaters adjacent to estuaries. In addition, this study provided clear evidence that set net fishing practices could severely impact the natural recruitment and stock enhancement of fish resources due to the low selectivity of nets and the overlap with larval fish migration channels. The number of larval fish captured by the set net fishery was, roughly estimated, several times higher than the local enhancement released. To minimize the effects of net mesh size, considering the spatial-temporal distributions of fish larvae, set net fishing practices should be concentrated to summer and early autumn, though further research is required to comprehensively account for both the protection of fishery resources and livelihoods
Acoustic Presence of Cetaceans in the Miaodao Archipelago, China
Once an important cetacean habitat, the Miaodao Archipelago has been altered by human-induced disturbances over several decades. While cetacean diversity is known to have decreased, no recent data on species diversity around Miaodao are known to exist. Capitalizing on the high vocal activity of cetaceans, three passive acoustic surveys, including towed and stationary types, were undertaken to detect the presence of species-specific vocalizations in May 2021, October 2021, and July 2022, as most cetacean sightings occurred during May and August in recent years. The results revealed that the East Asian finless porpoise is the sole cetacean species that can be reliably observed around the archipelago, as no other species were detected. The acoustic data also revealed potentially clumped distributions of finless porpoises with some seasonal variation. While not acoustically detected during any of the surveys, humpback whales, minke whales, and killer whales have been visually sighted in the region. The lack of acoustic detection of these species suggests that they are likely to be temporary visitors to the region, or at least exhibit strong seasonality in their presence within the region. These new data provide the latest snapshot of cetacean presence around the Miaodao Archipelago that can help inform future research and conservation
GQDs Incorporated CoPc Nanorods for Electrochemical Detection of Dopamine and Uric Acid
Abstract Dopamine (DA) and uric acid (UA) are biomolecules of great consideration that coexist in human body. It is essential and challenging to detect them simultaneously with high sensitivity. This paper reports a novel electrochemical biosensor based on the nanocomposites of cobalt phthalocyanine (CoPc) anchored with graphene quantum dots (GQDs) for DA and UA detection. The GQDs incorporation on CoPc nanorods with partial end stretching significantly enhances the electrocatalytic activity and promotes the electron transfer rate. Low detection limits of 21Â nm for DA and 145Â nm for UA have been successfully achieved for the fabricated CoPc/GQDs biosensor. The densityâfunctional theory proves the enhanced conductivity of CoPc/GQDs and the biomolecule's interaction with the electrode surface. Furthermore, the proposed sensor shows remarkable reproducibility, repeatability, and stability. The fabricated sensor is applied for the simultaneous detections of DA and UA in human urine samples. The excellent performance suggests that the CoPc/GQDs could be a promising and potential candidate for electrochemical sensors to detect DA and UA selectively
Dexamethasone inhibits repair of human airway epithelial cells mediated by glucocorticoid-induced leucine zipper (GILZ).
BACKGROUND: Glucocorticoids (GCs) are a first-line treatment for asthma for their anti-inflammatory effects, but they also hinder the repair of airway epithelial injury. The anti-inflammatory protein GC-induced leucine zipper (GILZ) is reported to inhibit the activation of the mitogen-activated protein kinase (MAPK)-extracellular-signal-regulated kinase (ERK) signaling pathway, which promotes the repair of airway epithelial cells around the damaged areas. We investigated whether the inhibition of airway epithelial repair imposed by the GC dexamethasone (DEX) is mediated by GILZ. METHODS: We tested the effect of DEX on the expressions of GILZ mRNA and GILZ protein and the MAPK-ERK signaling pathway in human airway epithelial cells, via RT-PCR and Western blot. We further evaluated the role of GILZ in mediating the effect of DEX on the MAPK-ERK signaling pathway and in airway epithelium repair by utilizing small-interfering RNAs, MTT, CFSE labeling, wound-healing and cell migration assays. RESULTS: DEX increased GILZ mRNA and GILZ protein levels in a human airway epithelial cell line. Furthermore, DEX inhibited the phosphorylation of Raf-1, Mek1/2, Erk1/2 (components of the MAPK-ERK signaling pathway), proliferation and migration. However, the inhibitory effect of DEX was mitigated in cells when the GILZ gene was silenced. CONCLUSIONS: The inhibition of epithelial injury repair by DEX is mediated in part by activation of GILZ, which suppressed activation of the MAPK-ERK signaling pathway, proliferation and migration. Our study implicates the involvement of DEX in this process, and furthers our understanding of the dual role of GCs
Silencing of <i>GILZ</i> partially abrogated the effect of DEX on proliferation of 9HTE cells.
<p>(A) 9HTE cells were transfected with non-specific si-RNA or <i>GILZ</i> si-RNA in the absence or presence of DEX. The effect of <i>GILZ</i> knockout on 9HTE cell proliferation was measured via MTT assay, and absorbance was read at 490 nm (0.749±0.057 in the non-specific si-RNA group compared with 0.697±0.057 in the DEX-treated/non-specific si-RNA group, *<i>P</i><0.05, nâ=â3). (B) 9HTE cells were labeling with CFSE and the CFSE fluorescence intensity was measured by flow cytometry (6.468±1.463 in the non-specific si-RNA group and 5.233±0.970 in the DEX-treated/GILZ si-RNA group compared with 2.765±0.539 in the DEX-treated/non-specific si-RNA group, *<i>P</i><0.05, nâ=â4).</p
Differential expressions of components of the MAPK-ERK pathway in non-specific si-RNA, DEX-treated/non-specific si-RNA, and DEX-treated/<i>GILZ</i> si-RNA-transfected 9HTE cells.
<p>Cellular proteins were collected from 9HTE cells transfected with non-specific si-RNA or <i>GILZ</i> si-RNA in the absence or presence of DEX for 24 h. Western blot was performed to detect levels of the phosphorylated forms of Raf-1, Mek1/2, and Erk1/2, and the respective total proteins (p-Raf-1, p-Mek1/2, p-Erk1/2: 0.935±0.056, 0.965±0.042, 0.959±0.052 in the non-specific si-RNA group compared with 0.574±0.143, 0.694±0.145, 0.712±0.066 in the DEX-treated/non-specific si-RNA group, compared with 0.861±0.087, 0.849±0.067, 0.840±0.061 in the DEX-treated/<i>GILZ</i> si-RNA group, nâ=â3). *Indicates a significant difference (<i>P</i><0.05), ÎČ-actin was used as the loading control.</p