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| 2. |
- Blösch, Günter, et al.
(author)
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Twenty-three unsolved problems in hydrology (UPH) - a community perspective
- 2019
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In: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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Journal article (peer-reviewed)abstract
- This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
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| 3. |
- Xue, Ru, et al.
(author)
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Variations of methane fluxes and methane microbial community composition with soil depth in the riparian buffer zone of a sponge city park
- 2023
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In: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 339
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Journal article (peer-reviewed)abstract
- Riparian buffers benefit both natural and man-made ecosystems by preventing soil erosion, retaining soil nu-trients, and filtering pollutants. Nevertheless, the relationship between vertical methane fluxes, soil carbon, and methane microbial communities in riparian buffers remains unclear. This study examined vertical methane fluxes, soil carbon, and methane microbial communities in three different soil depths (0-5 cm, 5-10 cm, and 10-15 cm) within a riparian buffer of a Sponge City Park for one year. Structural equation model (SEM) results demonstrated that vertical methane fluxes varied with soil depths (lambda =-0.37) and were primarily regulated by methanogenic community structure (lambda = 0.78). Notably, mathematical regression results proposed that mcrA/ pmoA ratio (R2 = 0.8) and methanogenic alpha diversity/methanotrophic alpha diversity ratio (R2 = 0.8) could serve as valid predictors of vertical variation in methane fluxes in the riparian buffer of urban river. These findings suggest that vertical variation of methane fluxes in riparian buffer soils is mainly influenced by carbon inputs and methane microbial abundance and community diversity. The study's results quantitatively the relationship between methane fluxes in riparian buffer soils and abiotic and biotic factors in the vertical di-rection, therefore contributing to the further development of mathematical models of soil methane emissions.
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| 4. |
- Chen, David, et al.
(author)
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CHANGE-POINT ALTERATIONS OF EXTREME WATER LEVELS AND UNDERLYING CAUSES IN THE PEARL RIVER DELTA, CHINA
- 2009
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In: Rivers Research and Applications. - : Wiley. - 1535-1459 .- 1535-1467. ; 25, s. 1153-1168
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Journal article (peer-reviewed)abstract
- In this paper, the Bayesian model and Lepage test were used to detect change point and to analyse associated statistical properties of high/low water levels in summer (June, July and August (JJA)) and winter (December, January and February (DJF)) months across the PRD (Pearl River Delta). The results indicate that: (1) two time intervals, that is 1979-1981 and 1988-1995, witness abrupt changes of SmH/SmL (summer mean high water level/summer mean low water level). The lower PRD is dominated by increased mean and coefficient of variation (Cv) of SmH. Increased mean but decreased Cv of SmL can be observed in the Mainstem Pearl River; (2) WmL (winter mean low water level) and WmH (winter mean high water level) of about 74% of the total stations have two change points occurred roughly during 1969-1971 and 1993-1995. First change points of WmH are mainly characterized by increased mean and Cv, but decreased mean and increased Cv of WmL can be observed across major parts of the PRD. The driving factors causing abrupt changes of water levels are various. Intensive human activities cannot be ignored, for example in-channel dredging and reallocation of the streamflow within the river channels due to human-induced topographical changes of river channel. Different responses of high/low water levels to externally influencing factors and interactions between influencing factors make the alterations of the water levels across the PRD more complicated. The findings of this paper will be helpful for the management of the PRD and human mitigation to natural hazards under the changing environment. Copyright (C) 2008 John Wiley & Sons, Ltd.
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| 5. |
- Chen, Sichun, et al.
(author)
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Spatiotemporal Changes in Precipitation and Temperature in the Huaibei Plain and the Relation between Local Precipitation and Global Teleconnection Patterns
- 2019
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In: Journal of Hydrologic Engineering. - 1084-0699. ; 24:8
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Journal article (peer-reviewed)abstract
- The Huaibei Plain is one of the most severe water scarcity areas in China. Understanding of hydroclimatic variation in this area at different timescales and its relationship with global teleconnection patterns are important for assessment of water resources utilization. In this study, spatiotemporal changes of seasonal and annual precipitation and temperature, including trend, abrupt change, variability, and periodicity were examined to recognize the potential remarkable changes during the last 41 years. The relationship between precipitation in the Huaibei Plain and teleconnection patterns using climate indexes was revealed by applying singular value decomposition. Results showed a nonsignificant annual precipitation increase about 2.4 mm/year. The annual average temperature increased about 1.2°C during 1970-2010. The abrupt change of annual precipitation mainly occurred during the 1970s and 1980s, while the primary mutation points for temperature were detected in 1990s, especially in 1997. The mean areal precipitation is characterized by a statistically significant 2- to 4-year periodicity at different phases, and the 2- to 5-year band is the major cycle for annual average temperature in this region. A statistically strong 5- to 8-year periodicity for precipitation could be detected from the middle of the 1980s to the end of the 1990s. Precipitation has positive correlation with the West Pacific Pattern and El Nino Southern Oscillation. The investigated results might have considerable implications for managing water resources in the Huaibei Plain.
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| 6. |
- Yang, Liu, et al.
(author)
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Prenatal and postnatal early life exposure to greenness and particulate matter of different size fractions in relation to childhood rhinitis : A multi-center study in China
- 2024
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In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 938
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Journal article (peer-reviewed)abstract
- The impact of early life exposure to residential greenness on childhood rhinitis and its interaction with particulate matter (PM) of different size fractions remain inconsistent. Herein, we recruited 40,486 preschool children from randomly selected daycare centers in 7 cities in China from 2019 to 2020, and estimated exposure to residential greenness by the normalized difference vegetation index (NDVI) with a 500 m buffer. Exposure to ambient PM (PM1, PM2.5, and PM10) was evaluated using a satellite-based prediction model (daily, at a resolution of 1 km × 1 km). By mixed-effect logistic regression, NDVI values during pregnancy, in the first (0–1 year old) and the second (1–2 years old) year of life were negatively associated with lifetime rhinitis (LR) and current rhinitis (CR) (P < 0.001). PM in the same time windows was associated with increased risks of LR and CR in children, with smaller size fraction of PM showing greater associations. The negative associations between prenatal and postnatal NDVI and LR and CR in preschool children remained robust after adjusting for concomitant exposure to PM, whereas the associations of postnatal NDVI and rhinitis showed significant interactions with PM. At lower levels of PM, postnatal NDVI remained negatively associated with rhinitis and was partly mediated by PM (10.0–40.9 %), while at higher levels of PM, the negative associations disappeared or even turned positive. The cut-off levels of PM were identified for each size fraction of PM. In conclusion, prenatal exposure to greenness had robust impacts in lowering the risk of childhood rhinitis, while postnatal exposure to greenness depended on the co-exposure levels to PM. This study revealed the complex interplay of greenness and PM on rhinitis in children. The exposure time window in prenatal or postnatal period and postnatal concomitant PM levels played important roles in influencing the associations between greenness, PM and rhinitis.
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| 7. |
- Chen, Huihui, et al.
(author)
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Molecular, behavioral, and growth responses of juvenile yellow catfish ( Tachysurus fulvidraco ) exposed to carbamazepine
- 2024
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In: Aquatic Toxicology. - : Elsevier. - 0166-445X .- 1879-1514. ; 271
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Journal article (peer-reviewed)abstract
- Carbamazepine (CBZ) is an anticonvulsant medication used to treat epilepsy and bipolar disorder. Due to its persistence and low removal rate in wastewater treatment plants, it is frequently detected in the environment, raising concerns regarding its potential adverse effects on aquatic organisms and ecosystems. In this study, we aimed to assess the impact of CBZ on the behavior and growth of juvenile yellow catfish Tachysurus fulvidraco , a native and economically important species in China. Fish were exposed to CBZ at three concentrations of 1, 10, or 100 mu g/L for 14 days. The fish exposed to 10 and 100 mu g/L of CBZ exhibited decreased feeding, and a significant increase in cannibalistic tendencies was observed in fish exposed to 100 mu g/L CBZ. Acetylcholinesterase activity was increased in the brain of fish exposed to 100 mu g/L CBZ. CBZ also inhibited the growth of yellow catfish. To better elucidate mechanisms of toxicity, transcriptomics was conducted in both the brain and liver. In the brain, gene networks associated with neurotransmitter dysfunction were altered by CBZ, as well as networks associated with mitochondrial dysfunction and metabolism. In the liver, gene networks associated with the immune system were altered by CBZ. The current study improves comprehension of the sub-lethal effects of CBZ and reveals novel insight into molecular and biochemical pathways disrupted by CBZ, identifying putative key events associated with reduced growth and altered behavior. This study emphasizes the necessity for improved comprehension of the effects of pharmaceutical contaminants on fish at environmentally relevant levels.
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| 8. |
- Chen, Xiaohong, et al.
(author)
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Hydrological Design of Nonstationary Flood Extremes and Durations in Wujiang River, South China : Changing Properties, Causes, and Impacts
- 2013
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In: Mathematical problems in engineering (Print). - : Hindawi Limited. - 1024-123X .- 1563-5147. ; , s. 527461-
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Journal article (peer-reviewed)abstract
- The flood-duration-frequency (QDF) analysis is performed using annual maximum streamflow series of 1-10 day durations observed at Pingshi and Lishi stations in southern China. The trends and change point of annual maximum flood flow and flood duration are also investigated by statistical tests. The results indicate that (1) the annual maximum flood flow only has a marginally increasing trend, whereas the flood duration exhibits a significant decreasing trend at the 0.10 significant level. The change point for the annual maximum flood flow series was found in 1991 and after which the mean maximum flood flow increased by 45.26%. (2) The period after 1991 is characterized by frequent and shorter duration floods due to increased rainstorm. However, land use change in the basin was found intensifying the increased tendency of annual maximum flow after 1991. And (3) under nonstationary environmental conditions, alternative definitions of return period should be adapted. The impacts on curve fitting of flood series showed an overall change of upper tail from "gentle" to "steep," and the design flood magnitude became larger. Therefore, a nonstationary frequency analysis taking account of change point in the data series is highly recommended for future studies.
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| 9. |
- Du, Chenqiu, et al.
(author)
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Home dampness/mold(D/M) improvement in children's residences over the past decade in China-a comparison of repeated surveys in 2010 and 2019
- 2021
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In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 205
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Journal article (peer-reviewed)abstract
- There is mounting evidence that exposure to household dampness/mold (D/M) is the cause of respiratory, allergic diseases for children. While few research focuses on the effects caused by building environment changes, from a longitudinal investigation perspective, especially for China experiencing a rapid development in recent years. This study aimed to explore the changes of D/M in Chinese homes over the past 10 years and identify the impacts of climate, building energy efficiency and residents' behaviors. The cross-sectional surveys were repeatedly conducted in children' residences in 2010 (Period I) and 2019 (Period II), among Taiyuan, Urumqi in northern China, and Nanjing, Shanghai, Wuhan, Changsha, Chongqing in southern China. Finally, 23465 children in Period I and 34720 children in Period II were involved, with no changes of residences since birth. The results showed that the proportions for reported D/M indicators were significantly reduced in Period II: e.g., 93.8% and 84.1% residents respectively answered no visible mold spots and damp stains in current residences, compared to only 78.3% and 62.2% in Period I. Southern homes accounted for high proportions for D/M indicator occurrences; warm-humid climate, annual higher precipitation and lower sunshine hours, etc., exacerbated the indoor D/M exposure risks. While residents' behaviors like ventilation, airing quilt/beddings, regular cleaning ameliorated the reported D/M significantly. The findings, from a temporal and spacious dimension perspective, advance our understanding of indoor D/M changes, precisely improvement in children' homes over the past 10 years, benefiting to promote indoor air quality standards in China.
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| 10. |
- Fan, Ping, et al.
(author)
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The influence of environmental factors on clinical pathological changes of patients with immunoglobulin A nephropathy from different areas of China
- 2018
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In: Renal failure. - 0886-022X. ; 40:1, s. 597-602
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Journal article (peer-reviewed)abstract
- RESULTS: It was shown that the frequency of the patients with no mucosal infection in the urinary tract was higher in the Guangzhou group, while the frequencies of upper respiratory tract and biliary infections were lower when compared with those in the Xi'an group. Serum uric acid, alexin C3, creatinine and serum cholesterol concentrations were increased in the Guangzhou group, while triglyceride, glomerular filtration rate, and urine red blood cell count level decreased. IgA + IgM + C3 and IgA + IgG + IgM + C3 were found in most patients of the Xi'an group, whereas IgA + C3, IgA + IgM + C3 and IgA were more frequent in the Guangzhou group.CONCLUSION: It was found that differential environment, life habits and patterns in the two investigated areas obviously may influence the variable characteristics of IgAN patients.METHODS: Patients who were identified to have primary IgAN by renal biopsy diagnosis were recruited both from Shaanxi province hospital of traditional Chinese medicine and Guangdong province hospital of traditional Chinese medicine. Besides renal histopathology data, a number of clinical and laboratory data were collected.OBJECTIVES: The effects of regional characteristics of IgAN patients in different areas of China were investigated.
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