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Abstract Since the completion of Three Gorges Dam in 2008, a large water-level fluctuation zone with anti-seasonal submergence has formed between the elevations of 145 m and 175 m in the Three Gorges Reservoir in China. In addition to hydrological regime, revegetation has also occurred in this water-level fluctuation zone. However, how the hydrological regime and revegetation regulate soil prokaryotic community remains unclear. Here, we investigated soil prokaryotic community structure, diversity and environmental parameters in different flooding zones from two soil layers (0–10 cm and 10–30 cm) at 6 locations along the water-level fluctuation zone from upstream to downstream. The soil prokaryotic diversity tended to decrease from upstream to downstream, and the alpha diversity was higher in the topsoil than in the deep soil at all sites. Flooding significantly enhanced the prokaryotic diversity compared to the control (i.e., permanent dry zone). The soil prokaryotic composition underwent deterministic processes in the upstream sites and stochastic processes in the downstream sites, with stronger stochastic processes in the topsoil than in the deep soil across all sites and elevations. As expected, the soil pH, moisture, NH 4 +-N, organic carbon and nitrogen were proven to be determinants of the prokaryotic community composition. Changes in plant traits (plant biomass, richness, and carbon content) after revegetation induced by submergence also played an important role in structuring the prokaryotic community. The prokaryotic community exhibited a shorter average path distance (GD) in the flooding zones compared to the control, with the shortest average degree (avgK) and the lowest levels of stability in the longer periodic inundation zones. Overall, our results suggest that soil properties and plant functional traits are critical controls of the prokaryotic community's ability to develop at regional scales and water submergence can likewise be an important factor for variations in the prokaryotic community composition in riparian zones. Graphical abstract Unlabelled Image Highlights • Prokaryotic community diversity decreased from upstream to downstream in riparian zone. • Flooding enhanced prokaryotic community diversity compared to permanent dry zone. • Prokaryotic community in periodic zones exhibited simple structure and low stability. • Revegetation regulated prokaryotic composition via indirect paths with plant C quality. • Stronger stochastic processes were found in the top soil than deep soil across sites. [ABSTRACT FROM AUTHOR]

Large water conservancy project can strongly alter the plant community composition, however, how these changes can potentially affect ecosystem carbon (C) and nitrogen (N) dynamics is not fully understood. Here, we investigated natural 13C and 15N abundance of C 3 and C 4 plants and soil in different fractions [labile C (LC) and N (LN), recalcitrant C (RC) and N (RN)]from 6 sites with two elevations (flooding zone, 145–175 m, area with revegetation due to flooding, N = 6); and unflooding zone, >175 m with original plant as a control, N = 3) in riparian zones of the Three Gorges Reservoir, China. The dominant species were the C 4 plants in the upstream including Changshou (CS), Fuling (FL) and Zhongxian (ZX) and the C 3 plants in the downstream in unflooding zone including Wanzhou (WZ) Badong (BD), and Zigui (ZG). C 4 plant in flooding zone was significant decreased by mean 25% compared with unflooding zone in the upstream but significantly increased the by mean 59% in the downstream. The 13C isotopic differences between soil and plant (Δδ13C) was lower than zero in both flooding and unflooding in the upstream, but was only lower than zero in flooding zone in the downstream. The proportion of C 3 -derived C in soil organic carbon pool (average 74.64%) was lower for the flooding zone compared to the unflooding zone (average 87.26%) in most sites, while the proportion of C 3 -derived C in LC (average 44.38%) was decreased in the flooding zone compared to the unflooding zone (69.52%) in the downstream. Additionally, the δ15N values of soil were higher than plant community in most sites, and were strongly associated with soil C and N pool content, as well as soil pH. Overall, our results revealed that soil C accumulation was primarily determined by C 3 plant in situ and new C input by existing dominant C 4 plant, whereas soil N dynamics was predictably dependent on soil relative C and N availability in response to flooding at regional scale. Unlabelled Image • Anti-seasonal flooding increased the C 4 plant percentage in the whole region. • The δ13C-soil was closed to δ13C value of C 3 plant in all sites. • The increased proportion of C 4 -derived C in soil was found in labile fraction. • The δ15N-soil was associated with soil C and N availability and soil pH. • Different patterns of soil C and N dynamics in response to flooding [ABSTRACT FROM AUTHOR]

Mumps remains a major global public health problem. Many studies have explored the relationship between meteorological factors and mumps, few have comprehensively explored such associations considering nonlinear relationship, delayed effects and collinearity in order to more accurately estimate them. This study aims to explore the relationship between meteorological factors and mumps in consideration of nonlinearity, delayed effects and collinearity. We collected daily reported mumps cases and meteorological data for Jining City, Shandong Province, China from 1 January 2007 to 31 December 2016. By building a Boosted regression tree model (BRT) for each day from lag 0 days to the maximum lag time, the optimal lag time was selected and the relationship between meteorological factors and mumps was explored for this lag time. From 2007 to 2016, a total of 15,064 cases of mumps were reported in Jining, with a sex ratio of 2.11:1. Cases were most prevalent in 5–9-year-olds (42.15%) followed by 10–14-year-olds (24.72%). The optimal lag time identified was 10 days and the three meteorological factors that contributed the most to the risk of mumps were daily mean temperature, daily mean relative humidity and daily mean sunshine duration. Their relative contribution rates were 24.4%, 19.9% and 18.3%, respectively. The mean temperature and sunshine duration relationships approximated a U-shaped effect on the risk of mumps, with estimated thresholds of 5.5 °C and 9.5 h, respectively. The effect of relative humidity on mumps increased slightly and then decreased rapidly, with a threshold of 64%. Our study indicates that daily mean temperature, relative humidity and sunshine duration were three significant meteorological factors associated with the incidence of mumps in Jining, China. Understanding the shape of relationships and their thresholds are critical for establishing early warning systems which are important tools in the prevention and control of mumps. Unlabelled Image • Nonlinear relationships, delay effects and collinearity problems have been considered in this study. • The optimal lag time was determined for the influence of meteorological factors on mumps incidence. • The threshold points for each meteorological factor were identified. • The relative contribution of meteorological factors to the onset of mumps was quantified. [ABSTRACT FROM AUTHOR]

Abstract Free-standing and flexible Cu@CuO nanowires (NWs) mesh as an easily recycled Fenton-like catalyst is developed for the first time. Dense CuO nanowire arrays were uniformly grown on a copper mesh surface simply by wet etching accompanied with thermal dehydration. These dense CuO NWs provide a large specific area and therefore guarantee excellent catalytic performance toward the degradation of rhodamine B (RhB). With a k -value of 0.23 min−1, such a Cu@CuO NWs mesh is able to degrade 100% RhB in only 16 min. This Fenton-like catalyst is also appropriate for degrading other organic dyes, including crystal violet, methylene blue, and rhodamine 6G. Unlike the conventional Fenton catalyst implemented at a pH value around 3, the Cu@CuO NWs mesh could adapt to a wide pH range from 2.1 to 12.0. More intriguingly, the Cu@CuO NWs mesh with excellent flexibility could be easily recycled after catalysis, which is a significant advance compared to the previously reported Fenton catalysts in the form of powders or nanoparticles. In addition, the recycling performance of this Cu@CuO NWs mesh was also assessed. On the basis of electron spin resonance (ESR) results, O2− rather than OH is the main active species for the dye degradation by the Cu@CuO NWs mesh. With a marvelous combination of excellent flexibility, wide pH adaptation, and high efficiency, this easily recycled three dimensional Cu@CuO NWs architecture can afford new ideas for the Fenton chemistry. Graphical abstract Unlabelled Image Highlights • The flexile 3D Cu@CuO nanowires (NWs) mesh was firstly used in Fenton catalysis. • Dense and uniform CuO nanowires were simply achieved by a two-step approach. • In a wide pH range, the mesh exhibited considerable catalytic activity. • The free-standing and flexible mesh allowed for easy recycling after catalysis. • The Cu@CuO NWs mesh possessed good recycling stability even after ten cycles. [ABSTRACT FROM AUTHOR]

The fate of soil organic carbon (SOC) sequestered by afforestation is crucial for the mitigation of the anthropogenic climate change but remains largely unclear. This lack of knowledge is particularly true for SOC turnover driven by enzyme activity. Here we measured hydrolase (including β-glucosidase, α-glucosidase, cellobiohydrolase and xylanase) and oxidase (including polyphenol oxidase and peroxidase) activities in soil aggregates following 30-year afforestation in central China. We also analyzed the relationships of enzyme activities with SOC concentrations, soil C:nitrogen (N) ratios and δ 13 C values of soil organic pool (removing any carbonates by acid hydrolysis) and stable pool (NaOCl–resistant). Afforestation significantly enhanced soil β-glucosidase, α-glucosidase and xylanase activities in bulk soil, as well as SOC concentrations in bulk soil and all aggregate fractions compared to those in the open area and cropland. In particular, the woodland increased SOC concentration in >2000 μm macroaggregates by 4.2- and 3.2-fold, compared to the open area and cropland, respectively. Soil hydrolase activities were generally lower but SOC concentrations were higher in >2000 μm macroaggregates compared with those in other aggregate fractions following afforestation. Hydrolase activities were negatively correlated with SOC and C:N ratios in soil aggregate fractions following afforestation. Results of structural equation modeling indicated that the increasingly inhibited hydrolase activities with increasing soil aggregate size indirectly promoted SOC sequestration following afforestation. In addition, both hydrolase and oxidase were positively correlated with δ 13 C values in the stable pool of the afforested soils, confirming the essential role of enzymes for SOC turnover in soil aggregates following afforestation. Overall, our results highlight the importance of unevenly distributed enzyme activities among soil aggregates in regulating SOC sequestration following afforestation. [ABSTRACT FROM AUTHOR]

Nowadays, it is extremely urgent to search for efficient and effective catalysts for water purification due to the severe worldwide water-contamination crises. Here, 3D Fe@VO 2 core-shell mesh, a highly efficient catalyst toward removal of organic dyes with excellent recycling ability in the dark is designed and developed for the first time. This novel core-shell structure is actually 304 stainless steel mesh coated by VO 2 , fabricated by an electrophoretic deposition method. In such a core-shell structure, Fe as the core allows much easier separation from the water, endowing the catalyst with a flexible property for easy recycling, while VO 2 as the shell is highly efficient in degradation of organic dyes with the addition of H 2 O 2 . More intriguingly, the 3D Fe@VO 2 core-shell mesh exhibits favorable performance across a wide pH range. The 3D Fe@VO 2 core-shell mesh can decompose organic dyes both in a light-free condition and under visible irradiation. The possible catalytic oxidation mechanism of Fe@VO 2 /H 2 O 2 system is also proposed in this work. Considering its facile fabrication, remarkable catalytic efficiency across a wide pH range, and easy recycling characteristic, the 3D Fe@VO 2 core-shell mesh is a newly developed high-performance catalyst for addressing the universal water crises. [ABSTRACT FROM AUTHOR]