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Economic efficiency of rainfed wheat farmers under changing climate: evidence from Pakistan Полный текст
2020
Mahmood, Nasir | Arshad, Muḥammad | Kächele, Harald | Ullah, Ayat | Müller, Klaus
Rainfed wheat farming directly depends upon climatic indicators and is mostly at the mercy of climatic extremes. This study analyzed the relationship between the economic efficiency of rainfed wheat farmers and indicators of climate variability in Pakistan employing a two-stage methodological framework. We used farm household level crop input-output and management data and secondary data on climate. In the first stage, a stochastic production frontier (SPF) approach was used to calculate economic efficiency. Then, in the second stage, the calculated economic efficiency scores were regressed against the temperature threshold, temperature anomaly, and total rainfall, in addition to socioeconomic, institutional, and farm variables, using OLS and quantile regression models. The results showed that temperature anomaly and the number of days when temperatures exceed 30 °C have negative and significant impacts on the economic efficiency of rainfed wheat farmers. Total rainfall showed positive and significant impacts across both OLS and quantile regression models. Further, we modeled a novel and very important variable in the context of rainfed wheat production in Pakistan, that is, farmers’ participation in trainings in climate-resilient crop farming. This variable showed a positive and highly significant impact on economic efficiency of wheat farmers across all regression models. Our findings call for important policy implications, including developing up-to-date climate resilient adaptation strategies that are particularly focused on rainfed wheat farming. Establishing strong linkages between extension departments and rainfed wheat farmers could help sustain and improve the efficiency of rainfed wheat farmers and hence food and livelihood security.
Показать больше [+] Меньше [-]Groundwater contamination sources identification based on kernel extreme learning machine and its effect due to wavelet denoising technique Полный текст
2020
Li, Jiuhui | Lu, Wenxi | Wang, Han | Bai, Yukun | Fan, Yue
Measurements of contaminant concentrations inevitably contain noise because of accidental and systematic errors. However, groundwater contamination sources identification (GCSI) is highly dependent on the data measurements, which directly affect the accuracy of the identification results. Thus, in the present study, the wavelet hierarchical threshold denoising method was employed to denoise concentration measurements and the denoised measurements were then used for GCSI. A 0–1 mixed-integer nonlinear programming optimization model (0–1 MINLP) based on a kernel extreme learning machine (KELM) was applied to identify the location and release history of a contamination source. The results showed the following. (1) The wavelet hierarchical threshold denoising method was not very effective when applied to concentration measurements observed every 2 months (the number of measurements is small and relatively discrete) compared with those obtained every 2 days (the number of measurements is large and relatively continuous). (2) When the concentration measurements containing noise were employed for GCSI, the identifications results were further from the true values when the measurements contained more noise. The approximation of the identification results to the true values improved when the denoised concentration measurements were employed for GCSI. (3) The 0–1 MINLP based on the surrogate KELM model could simultaneously identify the location and release history of contamination sources, as well reducing the computational load and decreasing the calculation time by 96.5% when solving the 0–1 MINLP.
Показать больше [+] Меньше [-]Magnetic magnesium ferrite–doped multi-walled carbon nanotubes: an advanced treatment of chromium-containing wastewater Полный текст
2020
Verma, Bharti | Balomajumder, Chandrajit
Magnetic magnesium ferrite (MgFe₂O₄) nanoparticles (MMFNPs) were synthesized by employing the sol-gel method. These nanoparticles were ultrasonically decorated onto the multi-walled carbon nanotubes (MWCNTs) to produce magnetic magnesium ferrite nanocomposites (MMFNCs). The as-prepared materials were investigated for their capability to treat wastewater loaded with heavy metals. The synthesized nanocomposites were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transmission infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and zeta analyzer. Besides, the effect of the environmental chemistry of the solution was determined by varying the critical parameters. The adsorption isotherm of Cr(VI) adsorption onto the as-synthesized MMFNC best fitted the Langmuir adsorption isotherm model. The high adsorption capacity of 175.43 mg/g was achieved at a temperature of 40 °C under optimized conditions. Due to the magnetic nature of MMFNC, they are easily recoverable from the aqueous solution making them cost-friendly. Even after seven consecutive adsorption-desorption cycles, the MMFNC presented an efficiency loss of less than 20% for the removal of Cr(VI) ions. The presented development method offers prospects in developing a highly effective magnetic adsorbent for heavy metal removal from wastewater.
Показать больше [+] Меньше [-]How indebted farmers perceive and address financial risk in environmentally degraded areas in Bangladesh Полный текст
2020
Rahman, Airin | Jianchao, Luo | Adnan, K. M Mehedi | Islam, Md Din Il | Zhao, Minjuan | Sarker, Swati Anindita
In Bangladesh, the recent uncontrolled growth of industries near farmland and unplanned urbanization made the agricultural sector the most vulnerable and a massive threat to the food security of the country. Agricultural farms near to industrial zones face high production costs (poor air-water-soil quality, high labor cost) and low-profit margin (poor crop yield and crop loss due to frequent natural hazards). The government policy in this matter is not proper due to a lack of information. As a consequence, many of these farm owners adopt agricultural credit by themselves to manage the production cost. Basically, credit itself creates some other financial risks and the farmers needed to adopt different measures to handle these financial risks. In-depth research on this matter is important to improve the situation by providing relevant information that policymakers can plan an efficient policy framework. However, previous literature has overlooked this area of research. In this study, the researcher collected data on 400 rice farmers (debtors) from six different districts in greater Dhaka division (most degraded area in Bangladesh) and adopted probit model to analyze the influential factors affecting farmers’ financial risk management adoption decision and to identify the correlations between these decisions. The empirical findings indicate that education, access to technologies, household income, savings, and distance from the industrial areas are the major factors that affect farmer’s adoption choice and most of the farmers are risk-averse. Moreover, the adoption choice of one risk management tool may motivate farmers to adopt another.
Показать больше [+] Меньше [-]Microbial fuel cell system: a promising technology for pollutant removal and environmental remediation Полный текст
2020
Wu, Qing | Jiao, Shipu | Ma, Mengxing | Peng, Sen
The microbial fuel cell (MFC) system is a promising environmental remediation technology due to its simple compact design, low cost, and renewable energy producing. MFCs can convert chemical energy from waste matters to electrical energy, which provides a sustainable and environmentally friendly solution for pollutant degradations. In this review, we attempt to gather research progress of MFC technology in pollutant removal and environmental remediation. The main configurations and pollutant removal mechanism by MFCs are introduced. The research progress of MFC systems in pollutant removal and environmental remediation, including wastewater treatment, soil remediation, natural water and groundwater remediation, sludge and solid waste treatment, and greenhouse gas emission control, as well as the application of MFCs in environmental monitoring have been reviewed. Subsequently, the application of MFCs in environmental monitoring and the combination of MFCs with other technologies are described. Finally, the current limitations and potential future research has been demonstrated in this review.
Показать больше [+] Меньше [-]Radical scavenging and antiproliferative effect of novel phenolic derivatives isolated from Nerium indicum against human breast cancer cell line (MCF-7)—an in silico and in vitro approach Полный текст
2020
Arunachalam, Thangakumar | Khader, Syed Zameer Ahmed | Syed Zameer Ahmed, Sidhra | Vetrivel, Manimaran | Syed Ameen, Syed Tajudeen | Ameer Khadharu, Ibrahim Sheriff | Prabhu, Puniethaa | Jayachandran, Philp Robinson | Sabu, Dastageer M.
Multiple drug resistance and increased side effects due to allopathic drugs has warned scientific community with a global alarm to identify molecules from natural sources to combat diseases with minimum or no side effects. The present investigation was aimed to identify and isolate secondary metabolites from traditionally used Nerium indicum using conventional column chromatography which led to the isolation of two compounds, C-I (fractions NB4f1) and C-II (fractions NC13b1). Further characterized, it is elucidated using spectral data and identified as N-(4-hydroxy-phenyl)-2-methoxy-2-phenyl-acetamide, molecular formula C₁₅H₁₅NO₃, and molecular weight 257.3 (C-I) and N-(4-hydroxy-phenyl)-2-phenyl-N-phenylacetyl-acetamide, molecular formula C₂₂H₁₉NO₃, and molecular weight 345.4 (C-II). Further, the isolated compounds were investigated using in silico approach by Autodock tool with four different proteins specific for cancer and in vitro assessed cell proliferation, and apoptosis against human breast cancer MCF 7 cell line. The results of the in silico model demonstrated potent binding affinity of both compounds with the proteins representing that the isolated molecules could be a drug of choice for cancer. Further, the isolated compounds revealed significant inhibition of cell proliferation (IC₅₀ values 21 μg/mL for C-I, 19 μg/mL for C-II) with induced apoptosis with nuclear condensation effect on the MCF 7 cells in in vitro condition even at very low concentration. Compound treatment to MCF-7 cell line represented bright fetches indicating condensed chromatins and higher level of nuclear fragmentation with DAPI staining, indicating higher cell death due to induced apoptosis and confirmed using flow cytometry analysis representing inhibition of cell proliferation at S phase. Graphical abstract
Показать больше [+] Меньше [-]Correction to: Radical scavenging and antiproliferative effect of novel phenolic derivatives isolated from Nerium indicum against human breast cancer cell line (MCF-7)—an in silico and in vitro approach Полный текст
2020
Arunachalam, Thangakumar | Khader, Syed Zameer Ahmed | Syed Zameer Ahmed, Sidhra | Vetrivel, Manimaran | Syed Ameen, Syed Tajudeen | Ameer Khadharu, Ibrahim Sheriff | Prabhu, Puniethaa | Jayachandran, Philp Robinson | M. Sabu, Dastageer
The correct presentation of the Author names are shown in this paper.
Показать больше [+] Меньше [-]Spatiotemporal variations of DOM components in the Kushiro River impacted by a wetland Полный текст
2020
Shafiquzzaman, Md | Haider, Husnain | Bhuiyan, Muhammed A. | Ahmed, Abdelkader T. | AlSaleem, Saleem S. | Ghumman, Abdul Razzaq
Dissolved organic matter (DOM) has been recognized as a serious water quality problem in natural water bodies receiving pollution loads from point and nonpoint sources. The present study investigates the spatiotemporal variability of DOM composition in the Kushiro River and its tributaries (Eastern Hokkaido, Japan) impacted by the Kushiro wetland. Water samples were collected in the wet and dry seasons from several locations of the river and analyzed for DOM characteristics by UV–visible and excitation–emission matrix fluorescence spectroscopy techniques and by developing water quality index. Rather than the spatial effect, significant seasonal impacts on DOM pollution in the Kushiro River were observed. Overall concentrations of DOM decreased during the dry season. The increase of specific ultraviolet absorbance in the dry season indicated an increasing trend of humification, aromaticity and molecular weight of DOM. Five fluorescent peaks, including peaks A, C, M, B, and T were predicted by EEM spectra. Peaks A and C were found to be the most dominating peaks in both the seasons and indicated enrichment of humic-like matters in river water. The intensities of poly-aromatic humic substances as well as DOM components of microbial origin increase in the wet season and proteins like autochthonous DOM increase during the dry season. The study recognized the contribution of freshly produced DOM component by the decomposition of wetland plants in wet season and effect of snowfall in the dry season. Analysis of three fluorescence indices revealed that the river water primarily contains terrestrially dominated DOM. A significant impact of the adjacent WWTPs and wetland to the river water DOM were also observed. The water quality index of river water DOM showed low to medium levels of DOM pollution in the Kushiro River.
Показать больше [+] Меньше [-]Nitric oxide synthase-mediated sub-chronic injury and recovery in the small intestine of mice after oral administration with halloysite nanotubes Полный текст
2020
Hu, Tingting | Wang, Xiaoqin | Tan, Weihang | Nie, Kai | Xu, Xiaolong
Natural halloysite nanotubes (HNTs) with a hollow lumen have been widely applied in many fields, such as water purification, drug carriers, cosmetics, antibacterial, and scaffolds for tissue engineering. However, their in vivo toxicity is still largely unclear. The aim of this study is to evaluate sub-chronic oral toxicity of HNTs in the small intestine of mice. The results demonstrated that oral HNTs at low dose (5 mg/kg) for 30 days promoted mouse growth with no obvious adverse effect on the small intestine. The promotive effect on mouse growth disappeared after cessation of oral administration of HNTs. Oral HNTs at high dose (50 mg/kg) for 30 days induced aluminum (Al) and silicon (Si) accumulation and oxidative stress in the small intestine, which caused significant increases in the levels of cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) and inflammatory response and iNOS-mediated damages in the organ. Oral HNTs-induced changes in the small intestine at high dose were not observed after a 30-day recovery period. These findings provided the first evidence that oral HNTs-induced sub-chronic toxicity in the small intestine was reversible. The results suggest that HNTs at low concentration in environments have no adverse effect on mice, while there are health risks to mice under severe contamination by HNTs.
Показать больше [+] Меньше [-]Fractionation and chemical structure of dissolved organic matter in the rhizosphere associated with cadmium accumulation in tobacco lines (Nicotiana tabacum L.) Полный текст
2020
Zhao, Ming | Li, Tingxuan | Yu, Haiying | Zhang, Xizhou | Zheng, Zicheng | Wang, Yongdong | Liu, Tao | Gupta, Dharmendra K. | Huang, Huagang
Reducing cadmium (Cd) accumulation in flue-cured tobacco is the main degree to reduce the harm of Cd to human health. In this study, a rhizobag experiment was conducted to investigate the characteristics of dissolved organic matter (DOM) in the rhizosphere of a low-Cd-accumulating tobacco line (RG11) and its role in the processes of Cd accumulation by plants. Cd concentrations in the roots and leaves of RG11 were 24.09–25.30 and 31.08–34.41% lower, respectively, than those of Yuyan5 under Cd stress. Cd exposure promoted DOM accumulation in the rhizosphere soils of the two tobacco lines. DOM concentrations in the rhizosphere soils of RG11 were 8.29–14.31% lower than those of Yuyan5 under Cd stress. RG11 presented less hydrophilic acid and hydrophilic base fractions, along with more hydrophobic acid and hydrophobic base fractions of DOM in the rhizosphere than those of Yuyan5 under Cd exposure. Fourier transform infrared spectroscopy results showed that RG11 exhibited less O–H, C–H, C=C, COO–, and C–O functional groups in rhizosphere DOM than those of Yuyan5 under Cd stress. Thus, the DOM in the rhizosphere of RG11 showed lower ability to solubilize Cd in soils, resulting in less Cd uptake by roots. This could be considered to be one of the important mechanisms of low Cd accumulation in leaves of RG11.
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