The phosphorus (P) content in agricultural soils in catchments of lakes or rivers is an important issue because P is both an essential nutrient for high plant yields and a major contributor to ...eutrophication of water bodies. Thus, we have assessed the spatial distribution of soil P, impacts of environmental factors on its spatial variation, and associated pollution risks, in farmland around the Danjiangkou Reservoir, China. A total of 217 sites were sampled, including 121, 44 and 52 in dry cropland, paddy land and orchards, respectively. Total phosphorus (TP) contents in the sampled soils ranged from 0.230 to 1.893 g kg−1 and Olsen-P (a measure of available P) from 0.38 to 176 mg kg−1. Soil TP and Olsen-P had moderate and high variability, with coefficients of variation of 40% and 115%, respectively. Geostatistical analysis showed that both TP and Olsen-P had positive nugget effects, but TP had stronger spatial autocorrelations than Olsen-P (nugget-to-sill ratios: 22 and 50%, respectively). Total P was significantly influenced by temperature, elevation, aspect, soil pH, organic matter and precipitation, while Olsen-P was controlled by aspect and land use. The TP in soil was very similar in dry cropland and orchards (0.64 ± 0.19 and 0.61 ± 0.23 g kg−1, respectively), but substantially lower in paddy land (0.15 ± 0.25 g kg−1). Risks for P loss appeared to be very high, high, moderate and low in approximately 10, 40, 15 and 30% of the farmland in the Danjiangkou reservoir area, respectively.
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•Soil total phosphorus and Olsen-P had moderate and high variability, respectively.•Positive nugget effects were obtained for both total phosphorus and Olsen-P contents.•Total phosphorus had stronger spatial autocorrelations than Olsen-P.•Classical kriging performed well in modeling the P pollution risk index.
ABSTRACT
Background: During the past decade, an increasing number of prospective studies have focused on the association between vitamin D and cardiovascular disease (CVD). However, the evidence on ...the relation between serum 25-hydroxyvitamin D 25(OH)D and the risk of overt CVD is inconclusive.
Objective: We performed a dose-response meta-analysis to summarize and prospectively quantify the RR of low serum 25(OH)D concentration and total CVD (events and mortality).
Design: We identified relevant studies by searching PubMed and EMBASE up to December 2015 and by hand-searching reference lists. Prospective studies based on the general population and reported RRs and 95% CIs were included. A random-effects model was used to calculate the pooled RRs. Nonlinear association was assessed by using restricted cubic spline analyses.
Results: A total of 34 publications with 180,667 participants were eligible for the meta-analysis. We included 32 publications (27 independent studies) for total CVD events and 17 publications (17 independent studies) for CVD mortality. We observed an inverse association between serum 25(OH)D and total CVD events and CVD mortality, and the pooled RRs per 10-ng/mL increment were 0.90 (95% CI: 0.86, 0.94) for total CVD events and 0.88 (95% CI: 0.80, 0.96) for CVD mortality. A nonlinear association was detected for total CVD events (P-nonlinear < 0.001) and CVD mortality (P-nonlinear = 0.022).
Conclusion: Serum 25(OH)D concentration was inversely associated with total CVD events and CVD mortality from the observed studies.
It has been widely reported that biochar can be used as a cost-effective amendment to immobilize of heavy metal contaminants in soil. While less research has been conducted on effect of biochar ...long-term field aging on its properties and the adsorption capability. In this study, the characteristics of aged biochar were investigated by comprehensive characterization to elucidate its mechanism transformation for heavy metal immobilization. Our results showed that, compared to fresh biochar, the relative content of C of aged biochar was reduced by 34.12%, while O was increased by 8.79%. Additionally, the specific surface area, pore volume, pore size and oxygen-containing functional groups of aged biochar were significantly increased compared to the fresh biochar. Batch adsorption experiment indicated that the maximum adsorption for Cd2+ (Qm = 32.157 mg/g) and Pb2+ (Qm = 39.216 mg/g) on aged biochar surface was much larger than that of Cd2+ (Qm = 7.573 mg/g) and Pb2+ (Qm = 8.134 mg/g) on fresh biochar. The underlying adsorption mechanisms for Cd2+ and Pb2+ on fresh biochar were dominated by coprecipitation, cation exchange and cation-π interaction, whereas surface complexation and cation exchange appeared to be more vital for aged biochar, as more active adsorption sites and Oxygen-containing functional groups were formed on its surface during aging, which was well explained by BET, XPS, FTIR and Elemental Analysis. Our study found that the physicochemical properties of biochar changed significantly during field aging. Although these changes increased the adsorption of heavy metals by biochar, the reduced stability of biochar to passivated heavy metal ions.
•The physicochemical properties fresh and aged biochar are studied.•The immobilization capacity of biochar changed during field aging.•Transformation of functional groups cause by aging was investigated.•Coprecipitation cannot be found in aged biochar be proved.•The reduced stability of biochar to passivated heavy metal ions be found.
Aging has a significant effect on the performance of asphalt material. Reliable modelling of the change of asphalt mixture properties over time is crucial to evaluating and predicting the performance ...of the designed pavement. The objective of this study is to develop an aging model to accurately predict the cracking performance of asphalt mixtures over the pavement service life, as well as evaluate the aging susceptibility of mixtures over time. In this study, nine loose mixtures were conditioned in an oven at 95 °C for multiple durations to simulate different field aging times. The climatic aging index (CAI) developed by the National Cooperative Highway Research Program (NCHRP) 09-54 project was utilized to calculate the appropriate field aging durations corresponding to the different laboratory aging conditions. Complex modulus tests (
E
*) were conducted to measure the rheological properties of the conditioned mixtures and further construct the dynamic modulus and phase angle mastercurves. The mixture Glover–Rowe (
G
–
R
m
) parameter, incorporating both stiffness and relaxation capacity, was selected and used as the Aging Index Property to model the changes in mixture cracking properties with aging. The results of this study indicate that the developed mixture aging model can effectively capture the two aging reaction periods (fast and constant) of asphalt materials. The developed model can not only be used to evaluate the change of cracking properties over pavement service life, but also detect the aging susceptibility of asphalt mixtures.
This research addresses the paramount issue of enhancing safety and health conditions in underground mines through the selection of optimal sensor technologies. A novel hybrid MEREC-CoCoSo system is ...proposed, integrating the strengths of the MEREC (Method for Eliciting Relative Weights) and Combined Compromise Solution (CoCoSo) methods. The study involves a three-stage framework: criteria and sensor discernment, criteria weight determination using MEREC, and sensor prioritization through the MEREC-CoCoSo framework. Fifteen criteria and ten sensors were identified, and a comprehensive analysis, including MEREC-based weight determination, led to the prioritization of "Ease of Installation" as the most critical criterion. Proximity sensors were identified as the optimal choice, followed by biometric sensors, gas sensors, and temperature and humidity sensors. To validate the effectiveness of the proposed MEREC-CoCoSo model, a rigorous comparison was conducted with established methods, including VIKOR, TOPSIS, TODIM, ELECTRE, COPRAS, EDAS, and TRUST. The comparison encompassed relevant metrics such as accuracy, sensitivity, and specificity, providing a comprehensive understanding of the proposed model's performance in relation to other established methodologies. The outcomes of this comparative analysis consistently demonstrated the superiority of the MEREC-CoCoSo model in accurately selecting the best sensor for ensuring safety and health in underground mining. Notably, the proposed model exhibited higher accuracy rates, increased sensitivity, and improved specificity compared to alternative methods. These results affirm the robustness and reliability of the MEREC-CoCoSo model, establishing it as a state-of-the-art decision-making framework for sensor selection in underground mine safety. The inclusion of these actual results enhances the clarity and credibility of our research, providing valuable insights into the superior performance of the proposed model compared to existing methodologies. The main objective of this research is to develop a robust decision-making framework for optimal sensor selection in underground mines, with a focus on enhancing safety and health conditions. The study seeks to identify and prioritize critical criteria for sensor selection in the context of underground mine safety. The research strives to contribute to the mining industry by offering a structured and effective approach to sensor selection, prioritizing safety and health in underground mining operations.
The balance between crop yield, quality and soil nutrient status can be manipulated by exploiting nutrient interactions. Field experiments were conducted in citrus orchards in Danjiangkou, Hubei ...Province to assess the effects of N (0, 0.3, 0.6 and 0.9 kg plant−1), P (0, 0.1, 0.2, 0.3 kg plant−1), K (0, 0.15, 0.30, 0.45 kg plant−1) and their interactions on residual nutrient content in soils, and the yield and quality of satsumas. The results showed that the effects of N and K fertilizers on the yield and quality of satsumas were greater than those of P fertilizers. Appropriate application rates of N (0.6 kg plant−1), P (0.3 kg plant−1) and K (0.15 kg plant−1) significantly improved yield and quality. Lack or excess or inappropriate ratios of N, P and K fertilizer can affect the absorption and utilization of nutrients and reduce yield and quality. The best fertilizer combination, determined by comprehensively considering yield, quality and environment, was N0.3P0.2K0.3, which delivered moderate yield, high fruit quality and low potential risk of pollution. The amount of fertilizer in this case was 0.3 kg N, 0.2 kg P, 0.3 kg K per plant, which is lower than the current recommended application rates (0.5–0.8 kg N, 0.2–0.5 kg P, 0.25–0.64 kg K, respectively). The economic benefit did not decrease because of a decline of yield, but increased slightly because of the improved fruit quality and the reduction in fertilizer input, compared with the treatment with the highest yield. Therefore, we suggest that it is necessary to consider the quality of agricultural products and environmental protection when applying fertilizer and to reduce N and P fertilizer input and appropriately increase the proportion of K.
Aging can significantly affect the performance of asphalt mixtures, causing increase in stiffness, reduction in relaxation capability and increase in cracking susceptibility. It is also well known ...that fundamental viscoelastic properties are used for design and modelling of asphalt mixtures and pavement structures to addressing rutting, fatigue and thermal cracking concerns. The objective of this paper is to study how the viscoelastic properties of asphalt mixture change over time, and evaluate and identify the cracking and aging susceptibility of asphalt mixtures with different mix variables during material selection and mixture design. Ten mixtures are evaluated using different laboratory conditioning protocols to simulate a range of aging levels in the field. The complex modulus test is then conducted on the lab aged mixtures to measure the viscoelastic properties in order to construct the dynamic modulus and phase angle master curves. The mixture Glover-Rowe (G-Rm) parameter and the shape parameters of the dynamic modulus and phase angle master curves, including inflection point frequency (−β/γ), difference between the glassy modulus and the inflection point modulus (γ), peak value of phase angle (a) and the horizontal position (frequency) of the peak phase angle value (c), are determined and evaluated for the mixtures with different aging conditions and mix variables. The study indicates the ability of the G-Rm parameter and all the master curve shape parameters to capture the effect of different aging conditions on linear viscoelastic mixture properties, as well as the cracking and aging susceptibility of asphalt mixtures.
•Rheological parameters can capture the cracking and aging susceptibility of asphalt mixtures.•Mixtures with higher initial relaxation capability and better cracking performance have the tendency to age more severely.•The G-Rm parameter can be used as a performance index to indicate the propensity for crack initiation of asphalt mixtures.
Numerous studies have examined the associations between air pollution and stroke. However, little is known about the associations between air pollution and transient ischemic attack (TIA). In this ...study, we aimed to conduct a time-series study to systematically examine the associations between hospital admissions for TIA and air pollutants. Admissions for TIA (ICD-10: G45) from 1 January 2014 to 31 December 2016 were identified based on the primary diagnosis from 134 hospitals in Beijing, China. Hourly measurements of air pollutants were obtained from the National Air Pollution Monitoring System. Generalized additive models with quasi-Poisson regression were used to determine the associations for each pollutant. Additionally, stratified analysis was implemented to examine whether age, gender, temperature, and season were the potential effect modifiers. Restricted cubic spline was applied to investigate the exposure-response curve. In total, 109,975 hospital admissions for TIA were included. The positive associations were detected between PM
2.5
, PM
10
, SO
2
, NO
2
, and CO and hospital admissions for TIA. The effects of PM
2.5
and PM
10
in men are stronger than in women. Additionally, the effects of PM
2.5
, PM
10
, SO
2
, and O
3
are more pronounced on warm days than cool days. From exposure-response curves, we observe a nearly linear relationship for PM
2.5
, PM
10
, CO, and NO
2
. Further studies are needed to verify the association. This research contributes evidence on the association between air pollution and admissions for TIA in the low- and middle-income countries and may promote related public health policy development.
Channel pruning has recently become a widely used model compression method. However, most existing channel pruning methods only prune to decrease the model size, such as the number of parameters or ...FLOPs, and hence the decrease in model size does not effectively lead to an improvement in inference performance. To address this problem, this paper proposes a latency-optimized channel pruning method for CNN inference acceleration on GPU platforms by latency stair-step discrimination, two-stage benefit assessment and latency-sharing channel pruning. Compared with recent state-of-the-art model compression methods, it can achieve significant improvements in inference performance with comparable compression rates and model accuracy. The contributions of this paper include the following: first, a three-point latency stair-step discrimination method is proposed for determining the candidate prunable coordinates with the best latency performance adapted to the current hardware. Then, a two-stage benefit assessment method based on interlayer dependencies is proposed for determining the optimal channel pruning rate of each layer in the network. Finally, a latency-sharing channel pruning framework is proposed to accelerate the model pruning adaptation process. The method proposed in this paper can significantly reduce the model inference latency on multiple types of GPU platforms. To verify the effectiveness, we use three general-purpose GPU platforms and two embedded GPU platforms to evaluate the algorithm performance. The experimental results show that for recent state-of-the-art CNNs, the proposed method can achieve a 22.0–6.6% latency reduction and a 1.3 –3.0 inference performance improvement as well as a 1.2–4.3 pruning adaptation speedup with high model accuracy.
Mulching management has been used in many places all over the world to improve agricultural sustainability. However, the cycling of carbon in the soil under applications of mulch on sloping arable ...land is not yet fully understood. A four-year field experiment was carried out in Xiaofuling watershed of Danjiangkou reservoir in China. The object was to evaluate the effects of the application of straw mulch (ST) and grass mulch (GT) on dynamic changes in soil organic carbon and its fractions. Results showed that mulch applied on the soil surface increased the contents of SOC and its active fractions in the soil. Compared to the control without cover (CK), ST and GT treatments increased the contents of SOC, LOC, DOC, POC and EOC by 14.73%, 16.5%, 22.5%, 41.5% and 21%, respectively, in the 0-40 cm soil layer, and by 17%, 14%, 19%, and 30%, respectively, in the 0-100 cm soil layer. The contents of organic carbon and its active fractions decreased with increasing soil depth in all of the treatments. SOC was accumulated in the period of December to the following March. The contents of soil DOC and LOC were high in January to March, while the contents of soil POC and EOC were high in June to September. The relative contents of soil organic carbon fractions were POC > EOC > LOC > DOC over the four years. Straw mulching had no significant effect on the changes in soil organic carbon active fractions during the different periods. Based on this long-term field experiment in Danjiangkou reservoir, we found that straw mulching had a significant effect on soil, increasing SOC content and stock in slopping arable land, and that live grass mulching was more effective than rice straw mulching. We discuss possible optimal periods for the implementation of mulching practices on sloping land.
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