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Land use change simulation and spatial analysis of ecosystem service value in Shijiazhuang under multi-scenarios Texto completo
2021
Gao, Xing | Wang, Jie | Li, Chenxi | Shen, Weining | Song, Zhaoying | Nie, Chengjing | Zhang, Xueru
Simulating changes in the value of ecosystem services caused by land use changes in large cities under multiple scenarios is of great significance for cities to formulate land use policies and improve ecosystem services. Take Shijiazhuang, which is in the process of rapid urbanization, as an example. Based on the remote sensing image data and statistical yearbook of 1988, 1998, 2008, and 2018 as the basic data to analyze and estimate the 30 years of land use and ecosystem service value changes in Shijiazhuang. According to this, the CA-Markov model was used to simulate the land use change in Shijiazhuang under three scenarios in 2030 and estimate the value of ecosystem services under each scenario, using grid tools to visually express the spatial distribution of ecosystem service values and the degree of agglomeration under three scenarios. The results indicate that the most obvious feature of land use change in Shijiazhuang from 1988 to 2018 was that the farmland area decreased year by year, the built-up expanded rapidly, the farmland area decreased by 86,874.75 hm² in 30 years, and the built-up increased by 154,711.90 hm². In 1988, 1998, 2008, and 2018, the ecosystem service value of Shijiazhuang was 32.578 billion yuan, 32.799 billion yuan, 29.944 billion yuan, and 31.251 billion yuan respectively. In 2030, under three scenarios of natural development, farmland protection, and ecological protection, the value of ecosystem services is 331.111 billion yuan, 33.670 billion yuan, and 33.891 billion yuan in order. The hot spots are mainly concentrated in the northwest and southwest of Shijiazhuang, and cold spots are concentrated in the eastern cities, counties, and districts. Based on changes in land use brought about by urban expansion, simulating the value of ecosystem services under multiple scenarios in the future, providing scientific guidance for building urban ecological networks, and realizing sustainable urban ecological development.
Mostrar más [+] Menos [-]Assessment of anthropogenic pollution by monitoring occurrence and distribution of chemicals in the river Liffey in Dublin Texto completo
2021
Peñalver, Rosa | Jacobs, Matthew R. | Hegarty, Susan | Regan, Fiona
This paper evaluates for the first time the spatial distribution of a wide group of organic (phthalates, nitro, aliphatic, halogen, aromatic, phenol and amino compounds) and inorganic pollutants along the Liffey river in Dublin city. The work takes into account the effect of short-term weather conditions on the occurrence of these contaminants. The results showed that rainfall conditions affect the levels of pollutants along the river in the days following a rainfall event. In addition, the tributaries entering the river Liffey were not found to impact its water quality. In relation to organic pollutants, 2,4,6-trichlorophenol, 2-nitrophenol and phthalate compounds were found in many water samples between concentrations of 0.21 and 2.17 μg L⁻¹. On the other hand, dimethyl phthalate was present in certain samples at levels around 100 μg L⁻¹. The levels of these contaminants in the river were lower than the toxicity values reported in the literature. Regarding inorganic pollutants, nitrates were detected from 0.59 to 6.81 mg L⁻¹ increasing from upstream to downstream. Based on the chemical nature and applications of detected pollutants, the river contamination can be mainly related to agricultural, industrial activities as well as diffuse urban contributions. These vary with location within a short distance and have the potential to impact aquatic biodiversity as the chemical composition changes with rainfall events.
Mostrar más [+] Menos [-]Loss of E-cadherin due to road dust PM2.5 activates the EGFR in human pharyngeal epithelial cells Texto completo
2021
Tung, Nguyen Thanh | Ho, Kin-Fai | Niu, Xinyi | Sun, Jian | Shen, Zhenxing | Wu, Feng | Cao, Junji | Dung, Hoang Ba | Thuy, Tran Phan Chung | Hsiao, Ta-Chih | Liu, Wen-Te | Chuang, Hsiao-Chi
Exposure to road dust particulate matter (PM) causes adverse health impacts on the human airway. However, the effects of road dust on the upper airway epithelium in humans remain unclear. We investigated the involvement of the epidermal growth factor receptor (EGFR) after PM with an aerodynamic diameter of < 2.5 μm (PM₂.₅)-induced E-cadherin disruption of human pharyngeal epithelial cells. First, we collected road dust PM₂.₅ from 10 Chinese cities, including Wuhan, Nanjing, Shanghai, Guangzhou, Chengdu, Beijing, Lanzhou, Tianjin, Harbin, and Xi’an. Human pharyngeal FaDu cells were exposed to road dust PM₂.₅ at 50 μg/mL for 24 h, cytotoxicity (cell viability and lactate dehydrogenase (LDH)) was assessed, and expressions of the proinflammatory interleukin (IL)-6 and high-mobility group box 1 (HMGB1) protein, receptor for advanced glycation end products (RAGE), occludin, E-cadherin, EGFR, and phosphorylated (p)-EGFR were determined. The E-cadherin gene was then knocked down to investigate EGFR activation in FaDu cells. Exposure to road dust PM₂.₅ resulted in a decrease in cell viability and increases in LDH and IL-6. Our data suggested that PM₂.₅ could decrease expressions of occludin and E-cadherin and increase expressions of EGFR and p-EGFR, which was confirmed by E-cadherin-knockdown. Our results showed a negative association between the alterations in E-cadherin and total elemental components in correlation analysis, especially S, Cl, K, Ti, Mn, Fe, Cu, Zn, and Pb. Exposure to metals in PM₂.₅ from road dust may lead to loss of the barrier function of the upper airway epithelium and activation of the EGFR. Our study showed the adverse effects of road dust PM₂.₅ on pharyngeal epithelial cells of the human upper airway.
Mostrar más [+] Menos [-]Assessment of metal enrichment and contamination in surface sediment of Mandovi estuary, Goa, West coast of India Texto completo
2021
Gaonkar, Cynthia V. | Nasnodkar, Maheshwar R. | Matta, Vishnu Murty
Metal concentration in the sediments was determined to assess the metal enrichment and level of contamination in the Mandovi estuary. The metal distribution in the Mandovi estuary revealed preferential input through open-cast iron-ore mining, industrial, fishing, and agricultural activities. The heavy riverine runoff associated with high rainfall influenced the distribution of Mn, Zn, and Pb during monsoon season. In addition, sediment grain size and associated organic matter governed metal distribution in surface sediments. The role of grain size and organic matter along with Fe-Mn oxides in the distribution of metals was construed through correlation and factor analysis. Geo-accumulation index, contamination factor, and potential contamination index indicated contamination of surficial sediments of the Mandovi estuary with Cr and Pb.
Mostrar más [+] Menos [-]Protective roles of grape seed (Vitis vinifera L.) extract against cobalt(II) nitrate stress in Allium cepa L. root tip cells Texto completo
2021
Kalefetoğlu Macar, Tuğçe | Macar, Oksal | Yalçın, Emine | Çavuşoğlu, Kültiğin
Excessive doses of toxic metals such as cobalt may cause detrimental hazards to exposed organisms. Six groups of onion bulbs were formed to investigate the therapeutic effects of grape seed extract (GSE) against cobalt(II) nitrate (Co(NO₃)₂) exposure in Allium cepa L. root tips. Control group was irrigated with tap water, while the latter groups were exposed to 150 mg/L GSE, 300 mg/L GSE, 5.5 ppm Co(NO₃)₂, 5.5 ppm Co(NO₃)₂ + 150 mg/L GSE and 5.5 ppm Co(NO₃)₂ + 300 mg/L GSE, respectively. Co(NO₃)₂ treatment seriously inhibited the root growth, germination and weight gain of the bulbs. Mitotic index was significantly decreased, whereas the chromosomal aberrations and micronuclei incidence exhibited a remarkable increase. In addition, Co(NO₃)₂ induced a variety of anatomical disorders in onion roots. Lipid peroxidation levels of the cellular membranes were assessed measuring the malondialdehyde content (MDA). MDA amount in Co(NO₃)₂-treated group reached the highest level among all groups. Co(NO₃)₂ treatment enhanced the activity of superoxide dismutase and catalase. The addition of GSE to Co(NO₃)₂ solution substantially suppressed the negative effects of Co(NO₃)₂ in a dose-dependent manner by strengthening the antioxidant defence system and reducing the cytotoxicity. Moreover, there was a significant recovery in growth parameters following the grape seed addition to Co(NO₃)₂. GSE had a remarkable reduction in genotoxicity when treated as a mixture with Co(NO₃)₂. Overall data obtained from this investigation proved that GSE, as a promising functional by-product, had a protective effect on Allium cepa L. against the toxic effects of Co(NO₃)₂.
Mostrar más [+] Menos [-]Toxicity and genotoxic evaluations in African catfish Clarias gariepinus (Burchell 1822) exposed to Act Force Gold®, Butaforce®, and Atraforce® Texto completo
2021
Nwani, Christopher Didigwu | Ejere, Vincent Chikwendu | Madu, Josephine Chinenye
Act Force Gold®, Butaforce®, and Atraforce® are among the most commonly used pesticides in Nigeria. The lethal concentrations and the respective toxic units for the three pesticides were determined. The genotoxic effects of the three pesticides were investigated in the red blood cells of Clarias gariepinus using micronucleus (MN) assay. The 96 h LC₅₀ was 4.75, 4.84, and 54.74 mg L⁻¹ for Act Force Gold®, Butaforce®, and Atraforce®, respectively. The toxic units in ascending order of toxicity were 1.83, 20.66, and 21.05 for Act Force Gold®, Butaforce®, and Atraforce® respectively. The estimated safe levels based on NAS/NAE varied from 4.75 × 10⁻¹–4.75 × 10⁻⁵ in Act Force Gold® through 4.64 × 10⁻¹–4.85 × 10⁻⁵ in Butaforce® to 5.74–5.74 × 10⁻⁵ in Atraforce®. Fish specimens were exposed to the pesticides and sampling was done at regular intervals at days 1, 7, 14, and 21 and after another 7-day recovery period. The results obtained indicated concentration- and duration-dependent increase in % MN formation with maximum values of 3.40 ± 0.25 for Act Force Gold® on day 14 and 3.05 ± 0.36 and 2.35 ± 0.14 for Butaforce® and Atraforce® respectively on day 7 of exposure. The 7-day recovery period could not reverse the trend as the % MN values obtained were significantly different from the control. The results further support the use of MN assay in assessing the toxicity of aquatic pollutants and can be used in the monitoring of aquatic ecosystems.
Mostrar más [+] Menos [-]Comparison of adsorption behaviors and mechanisms of methylene blue, Cd2+, and phenanthrene by modified biochars derived from pomelo peel Texto completo
2021
Li, Baoqing | Zheng, Zhiran | Fang, Jianzhang | Gong, Jiaxin | Fang, Zhanqiang | Wang, Wenxiang
Although biochar (BC) has been widely used to adsorb pollutants in environment due to its natural and green characteristics, the structural defects of BC limit the ability to remove various environmental pollutants in aqueous solution. In this study, oxidized biochar (OBC) and sulfhydryl biochar (SBC) derived from pomelo peel (PP) were prepared through an oxidation and esterification reaction. BC and modified BC were used for the removal of methylene blue (MB), Cd²⁺, and phenanthrene (PHE) in aqueous solution. The adsorption behavior and efficiency toward different types of pollutants were studied by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Raman, X-ray photoelectron spectroscopy (XPS), kinetics, and isotherm model fitting. The results showed that the change of pH had great effect on MB and Cd²⁺ adsorption, but not on PHE. SBC not only possessed the newly formed sp²-hybridized domains with easy access to aromatic pollutants but also had multiple functional groups (-COOH, -OH, -SH, -NH₂) that provided adsorption sites for positively charged pollutants. SBC was more flexible and efficient in purifying pollutants compared to BC and OBC, with the saturated adsorption capacities of MB (209.16 mg/g), Cd²⁺ (786.19 mg/g), and PHE (521.58 mg/g). Moreover, the adsorption kinetic and isotherms fitting showed that the adsorption mechanisms were closely related to the structure of biochar and the properties of pollutants, including π-π interaction, surface charge, electrostatic interaction, surface functional groups, and Van der Waals force. In addition, the analysis of structure-function relationship demonstrated the enhanced hydrophilicity and the easy exposure of the binding sites on OBC and SBC. Hence, it was significantly effective to regulate microstructure and interfacial properties to promote its adsorption behaviors of biochar.
Mostrar más [+] Menos [-]Bioaccumulation and bioconcentration of metals in Characidae from a Neotropical river basin under anthropic activities Texto completo
2021
da Silva, Cleber Pinto | da Silveira, Estevan Luiz | Seremeta, Daniele Cristina Hass | dos Santos Matos, Danilo Gabriel | Vaz-dos-Santos, André Martins | de Campos, Sandro Xavier
Natural rates of metal mobilization and deposition in terrestrial and aquatic environments have been changed due to anthropic activities, exposing the native biota to dangerous effects related to bioconcentration and bioaccumulation of metals. This study assessed the concentrations of Cr, Ni, Cd, Pb, Cu, Mn, Co, and Zn in the water and riverbed sediment samples from the Verde River basin (VR), and in tissue samples from two native fishes, the Psalidodon paranae, a VR inhabitant, and the Psalidodon aff. fasciatus, a migratory species. Arithmetic mean values of metal concentrations recorded in waters were Cr: 46.16, Ni: 40.29, Cd 43.19, Pb: 57.74, Cu: 63.72, Mn: 98.36, Co: 64.53, Zn: 81.19, while for riverbed sediments were Cr: 11.84, Ni: 10.52, Cd: 7.14, Pb: 15.00, Cu: 22.16, Mn: 334.77, Co: 24.62, Zn: 434.44. For several analyzed samples, metal concentrations found were higher than Brazilian and international limits set for healthy aquatic life and human uses. Analyzed fish tissues also presented metal concentrations higher than Brazilian and international limits set, indicating a high ecological and health risk for the region. Psalidodon paranae showed affinity to bioconcentrate Pb, Zn, and Cd, while Psalidodon. aff. fasciatus tended to bioconcentrate Ni, Zn, and Cr. Multivariate analyses revealed spatial and temporal patterns in the metal contaminations in VR. These patterns were associated with rural and urban activities developed along VR, which practice inadequate soil handling, indiscriminate use of agrochemicals, and the dumping of domestic garbage and untreated and treated sewage into the river. The implementation of public policies for biomonitoring and pollution control by metals in VR is essential to safeguard regional water resources and their biota.
Mostrar más [+] Menos [-]Forecasting fuel combustion-related CO2 emissions by a novel continuous fractional nonlinear grey Bernoulli model with grey wolf optimizer Texto completo
2021
Xie, Wanli | Wu, Wen-Ze | Liu, Chong | Zhang, Tao | Dong, Zijie
Foresight of CO₂ emissions from fuel combustion is essential for policy-makers to identify ready targets for effective reduction plans and to further improve energy policies and plans. A new method for forecasting the future development of China’s CO₂ emissions from fuel combustion is proposed in this paper by using grey forecasting theory. Although the existing fractional nonlinear grey Bernoulli model (denoted as FNGBM(1,1)) has been theoretically proven to enhance the adaptability to diverse sequences, its fixed integer-order differential derivative still impairs the performance to some extent. To this end, a varying-order differential derivative is introduced into the existing differential equation to enable a more flexible structure, thus improving the prediction ability of FNGBM(1,1). Specifically, because of the advantages of conformable fractional accumulation, the traditional differential derivative is first replaced by the conformable fractional differential derivative. As a consequence, the continuous conformable fractional nonlinear grey Bernoulli model (hereinafter referred to as CCFNGBM(1,1)) is proposed. To further increase the validity of the model, a metaheuristic algorithm, namely Grey Wolf Optimizer (GWO), is then applied to search for the optimal emerging coefficients for the proposed model. Two real examples and China’s CO₂ emissions from fuel combustion are considered to verify the effectiveness of the newly proposed model, the experimental results show that the newly proposed model outperforms other benchmark models in terms of forecasting accuracy. The proposed model is finally employed to forecast the future China’s CO₂ emissions from fuel combustion by 2023, accounting for 10,039.80 million tons. Based on the forecasts, several policy suggestions are provided to curb CO₂ emissions.
Mostrar más [+] Menos [-]Effect of phosphorus and potassium addition on greenhouse gas emissions and nutrient utilization of a rice-fish co-culture system Texto completo
2021
Feng, Jinfei | Liu, Yaobin | Li, Fengbo | Zhou, Xiyue | Xu, Chunchun | Fang, Fuping
Greenhouse gas (GHG) emissions from aquaculture have gained widespread attention. However, the effect of phosphorus (P) and potassium (K) on GHG emissions from aquaculture systems has rarely been studied. In this study, we conducted a laboratory-scale experiment to investigate the effect of P and K addition on CH₄ and N₂O emissions and nutrient use efficiency in a rice-fish co-culture system. The results showed that the CH₄ flux rate did not differ between the rice-fish co-culture (RF) and fish monoculture (F) systems. Phosphorus addition did not affect CH₄ emission from the RF. In contrast, K addition significantly increased the CH₄ emission from the RF by 148.4%. Dual P and K addition greatly increased the CH₄ emission from the RF by six times, indicating an interactive effect of P and K on the stimulation of CH₄ emission. Phosphorus addition strengthened the restorative effect of the RF on N₂O emission, while K addition weakened the restorative effect of the RF on N₂O emission. The combination of P and K did not affect the N₂O emission from the RF. The application of P and K strengthened the restorative effect of rice on nitrogen (N) pollution in aquaculture water. Phosphorus and K addition significantly increased the rice biomass and nutrient in the harvested rice, but did not affect the fish biomass and nutrient in the harvested fish. Dual P and K addition increased the nutrient use efficiency in the rice-fish system. These results provide a reference for adjusting nutrient management to reduce GHG emissions and improve nutrient use efficiency in the rice-fish system.
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