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In vitro antioxidant, antibacterial, and antihyperlipidemic potential of ethanolic Avicennia marina leaves extract supported by metabolic profiling Full text
2021
Yassien, Eman E. | Hamed, Moaz M. | Abdelmohsen, Usama Ramadan | Hassan, Hanaa M. | Gazwi, Hanaa S. S.
This study aimed to examine the impact of ethanolic Avicennia marina (A. marina) leaves extract against seven pathogenic bacteria and the protective effect of this plant against hyperlipidemia caused by dexamethasone (DEX)-treated rats. Forty-eight male rats weighing between 150 and 200 g were randomly selected into six groups containing eight rats in each group. Moreover, in vitro antioxidant DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, FRAP (ferric reducing antioxidant power), and ABTS assay were also analyzed for leaf extract. Results showed that the IC₅₀ values were observed as 193.9 ± 1.03 μg/mL, 340.29 ± 8.16 μM TE/mg, and 326.8 ± 6.14 μM TE/mg for DPPH, FRAP, and ABTS radical scavenging activities, respectively. A. marina leaves ethanolic extract exhibited higher activity against Candida albicans and Bacillus subtilis, moderate activity against Salmonella typhimurium, and Vibrio damsel. The administration of DEX resulted in significant (P < 0.05) increase in the levels of MDA concentration, TG, TC, LDL, LDH, and glucose but decreased significantly in HDL. Treatment with A. marina extract positively reversed the distorted lipid profile and peroxidation and improved MDA, GSH, NO, and SOD activities in DEX-administered rats. Histological investigation of liver tissue sections showed that the treatment with A. marina leaves extract moderate the fatty change caused by DEX. It is concluded that A. marina leaves extract improved the hypolipidemic property of DEX administration in comparison with standard treatment with atorvastatin.
Show more [+] Less [-]Oil exploration, biocapacity, and ecological footprint in Saudi Arabia Full text
2021
Samargandi, Nahla
Many countries encounter environmental imbalance where the ecological footprint is higher than biocapacity due to natural resource-induced economic growth. This paper focuses on Saudi Arabia, a prominent oil exporter, to assess the dynamic impact of oil extraction on ecological footprint and biocapacity by applying the quantile on quantile (QQ) approach. This empirical investigation demonstrates that a higher quantile of oil extraction is negatively associated with a lower quantile of ecological footprint; conversely, a lower quantile of oil extraction and a higher quantile of ecological footprint are positively associated. Additionally, a lower quantile of oil extraction and lower quantile of biocapacity are negatively associated. The empirical analysis confirms that oil extraction is somewhat less responsible higher score of ecological footprint due to efficient management in oil extraction and refinery process. Several policy implications of these findings are highlighted.
Show more [+] Less [-]Farmers’ perception and adaptations to climate change: findings from three agro-ecological zones of Punjab, Pakistan Full text
2021
ʻAlī, Muḥammad Faiṣal | Rose, Sobia
The main objective of this study was to capture farmers’ perceptions and adaptations to climate change in agriculture sector. Along with this, it also identified farmers’ adaptations to perceived climate change. Binary logit models were applied on data of 386 farmers, collected from three different agro-ecological zones of Punjab, Pakistan, to present a comprehensive analysis of different adaptation strategies missing in the existing literature. The coefficients of a binary logit model only explain the direction of change; therefore, to see the magnitude of change, marginal effects were also estimated. Findings revealed that farmers perceived climate change and opted different adaptation strategies. Results of binary logit models described age, education, farming experience, landholding, access to climate information, access to credit facilities, and access to extension services as important determinants of adaptation. This research also found lack of access to climate information, lack of irrigation resources, and knowledge about appropriate adaptations as key constraints in adaptation process. This situation can be improved by enhancing institutional support and capacity. It is suggested that improved agricultural education with better access to climate information and extension services affects the farmers’ well-being directly and hence is good for the economy of Pakistan.
Show more [+] Less [-]Climate change impact assessment on Northeast China’s grain production Full text
2021
Ha, Trinh Thi Viet | Fan, Honglu | Shuang, Li
The international community is paying more attention to climate change because a consensus has been reached that climate change has an adverse effect not only on the environment but also on agriculture. Therefore, in this study, present and future climate datasets (obtained from general circulation models) including atmospheric carbon concentration were used to assess the impact of climate change on grain production for an important base of China (Northeast). An empirical model has been developed using climate and other additional variables (effective irrigation area, fertilizer, and labor force) to assess the effect of climate change on grain production. The results revealed that maximum temperature is a key climate determinant in grain production of the study area. Atmospheric carbon concentration showed a significant impact on grain outputs in most of the cases. During the analysis, it was observed that precipitation displayed a declining trend while an effective irrigation area showed positive non-significant contribution to grain production. Analysis based on different representative concentration pathways exhibited that maximum temperature may contribute negatively to grain production in the future. Overall, the analysis showed that climate change has a significant contribution to grain production. In conclusion, the implications for future research and policymakers have been addressed. Particularly, the importance of considering regional differences in adaptation planning in agricultural regions was also considered.
Show more [+] Less [-]Heavy metal poisoning resistance of a Co-modified 3Mn10Fe/Ni low-temperature SCR deNOx catalyst Full text
2021
Zhu, Baozhong | Chen, Weiqi | Wang, Jinghui | Sun, Yunlan | Song, Weiyi | Zi, Zhaohui | Yu, Hailong | Liu, Enhai
Heavy metals have a great influence on the deNOₓ efficiency of catalysts. The 3Mn10Fe/Ni catalyst that used nickel foam (Ni) as the carrier, Mn and Fe as the active components, and Co as a trace auxiliary was prepared using an impregnation method. The catalysts poisoned by Pb or Zn and Co-modified catalysts with Pb or Zn poisoning were studied. The addition of Pb or Zn significantly decreases the deNOₓ activity of the 3Mn10Fe/Ni catalyst due to the decrease in the content of high-valence metal elements such as Fe³⁺ and Mn⁴⁺, lattice oxygen concentration, reduction performance, acidity, and the number of acid sites. However, after Co modification, the deNOₓ activity of the poisoned catalysts can be improved effectively because the strong interaction between Pb or Zn and lattice oxygen is weakened, and the contents of lattice oxygen, high valence metal elements, reduction ability, and the number of acid sites increase.
Show more [+] Less [-]Discussion on the existing methodology of entropy-weights in water quality indexing and proposal for a modification of the expected conflicts Full text
2021
Dash, Siddhant | Kalamdhad, Ajay S.
The present research focuses on addressing various ambiguities in the existing method of integrating information entropy and water quality, thereby presenting a novel approach for an entropy-weighted water quality index. A three-dimensional water quality dataset is considered in the proposed method, the third dimension being the sampling frequency factor. The probability of observed values adhering to desirable limits prescribed by a standard code is estimated, leading to the computation of information entropy and, eventually, entropy weights. These weights are then used for the computation of the Modified Entropy-weight Water Quality Index (MEWQI) values. To verify the proposed method’s applicability, the water quality dataset of Deepor Beel, India, was considered. IS 10500: 2012 was used for estimating MEWQI values. Results showed an excellent correlation with the observed dataset and their uncertainties of occurrence. The reliability and correctness of the proposed methodology were finally confirmed through both cluster analysis and sensitivity analysis. The cluster analysis showed remarkable associations with the computed MEWQI values, while the sensitivity analysis proved that no particular parameter was accountable for the contribution of MEWQI values; instead, all parameters exhibited equal contributions. The proposed methodology was thus found to be the most reasonable and reliable as it considered both factors, i.e., measured values concerning standard limits and the uncertainty, necessary for a consistent water quality monitoring program.
Show more [+] Less [-]Do economic openness and electricity consumption matter for environmental deterioration: silver bullet or a stake? Full text
2021
Jan, Ali | Xin-gang, Zhao | Ahmad, Munir | Irfan, Muhammad | Ali, Shahid
Developing countries are enthusiastically on the road to economic progress and economic openness, which is proved to be a silver bullet for them. However, it has put their environmental quality at stake. This study examines whether economic openness and electricity consumption matter for environmental deterioration by controlling for the influence of economic progress. For this, we have used time series frequency data of Pakistan from 1971 to 2016 and employed the state-of-the-art dynamic autoregressive distributed lag (ARDL) simulation model. The model has the advantage over traditional ARDL in determining the positive and negative environmental deterioration variations induced by economic openness, electricity consumption, and economic progress. The main findings are as follows: Firstly, electricity consumption in both long and short run positively and significantly influenced CO₂ emissions, while long-run influence exceeded that of short run. Secondly, economic progress validated an environmental Kuznets curve hypothesis and thus limited the environmental degradation. Thirdly, economic openness showed an insignificant influence on CO₂ emissions both in the long and short run. Based on research findings, it is suggested that economic progress and economic openness are not the direct culprits to deteriorate a developing country’s environmental condition like Pakistan; rather, electricity consumption remained the key role player. Therefore, the transition from fossil-based electricity consumption to renewable energy consumption would provide a sustainable pathway towards achieving sustainable economic openness in the future.
Show more [+] Less [-]Gibberellic acid application on biomass, oxidative stress response, and photosynthesis in spinach (Spinacia oleracea L.) seedlings under copper stress Full text
2021
Gong, Qin | Li, Zhao-hua | Wang, Ling | Zhou, Jing-yi | Kang, Qun | Niu, Duan-dan
The mechanism of Cu tolerance in plants and its control measures are of considerable significance for the remediation of Cu-contaminated soils. Gibberellic acid (GA₃) is involved in plant growth and development and in the response to heavy metal stress. In the present study, changes in the biomass, oxidative stress response responses, and photosynthesis of spinach seedlings were examined under Cu stress with exogenous GA₃ applied at concentrations of 0, 3, 5, 10, 20, 40, 60, or 80 mg L⁻¹. Under Cu stress, the plant Cu concentration and oxidative damage were greater, photosynthetic parameters and biomass declined, and antioxidant enzyme activities and the proline concentration increased. However, spinach growth did not terminate, indicating that spinach seedlings had strong Cu tolerance. When low concentrations of GA₃ (3–5 mg L⁻¹) were added to Cu-stressed spinach seedlings, the damage caused by Cu stress to spinach seedlings was reduced, and the Cu tolerance of spinach seedlings was enhanced, which mainly manifested as reduced oxidation damage, an increased proline concentration, elevated antioxidant enzyme activities, decreased Cu concentration in leaves, and increased Cu concentration in roots, increased photosynthetic parameters, and an increased in the total biomass. In contrast, additions of GA₃ at concentrations higher than 40 mg L⁻¹ intensified oxidative damage and decreased the activities of antioxidant enzymes, photosynthetic parameters, and biomass. Additionally, the Cu concentration increased in leaves and decreased Cu concentration in roots, indicating that high concentrations of GA₃ aggravated stress damage and severely influenced physiological functions in spinach seedlings. In summary, the application of 3–5 mg L⁻¹ GA₃ to spinach seedlings in Cu-contaminated soil can be used to reduce Cu toxicity to plants and increase Cu tolerance.
Show more [+] Less [-]Bioaccumulation of different congeners of Poly-Brominated Diphenyl Ethers (PBDEs) in muscle tissue of males and females of Clupea harengus from the North Sea Full text
2021
Gaion, Andrea | Morgan, Ellana | Collier, Stuart | Sartori, Davide
In the last decades, high concentrations of flame retardants (PBDE) in marine organisms have caused increasing concern among scientists with regards to their biomagnification potential and to human health. Poly-Brominated Diphenyl Ethers have been widely used in the past as flame retardants in various industrial sectors, and their presence in the biota has been associated with different toxicological effects. In this study, concentrations of 9 congeners of PBDE (183, 85, 153, 154, 99, 100, 47, 66 and 28) and morphometric parameters (Total Length, TL; Fork Length, FL in cm and weight) have been measured in muscle of males and females of Atlantic herring (Clupea harengus). Results showed no statistical differences between the concentrations of most of the congeners analysed between the two sexes, except for PBDE 153 (Mean ± standard error in males = 0.034 ± 0.005 μg/kg and in females = 0.086 ± 0.040 μg/kg; p = 0.003). This research contributes to better comprehend the ecotoxicological properties of these molecules and their implications for human consumption.
Show more [+] Less [-]Improving the diagnosis of bovine tuberculosis using gold nanoparticles conjugated with purified protein derivative: special regard to staphylococcal protein A and streptococcal protein G Full text
2021
El-Sayyad, Gharieb S. | Hasan, Omnia F. | Saad, Mohamed A. M. | El-Batal, Ahmed I.
Different ancillary immunodiagnostic tests were traditionally-established for diagnosis of bovine tuberculosis (BTB) either cellular or humoral as tuberculin skin test (TST), gamma interferon (INF-γ), and indirect enzyme-linked immunosorbent assay (iELISA). These tests had been consumed more time and expensive, and needed sophisticated equipment. To dissolve these problems, serological diagnosis depending on humoral immunity is the aim of this work. Herein, slide-based agglutination test was chosen as a rapid and simple field test based on purified protein derivative (PPD) antigen in addition to some supplementation materials such as Staphylococcal protein A (SPA) and Streptococcal protein G (SPG) to improve detection of BTB antibody in serum samples. Gold nanoparticles (Au NPs) were synthesized by gamma ray, and after complete characterization, the synthesized Au NPs were spherical, small-sized, and stable without any impurities. Addition of such supplementation reagents for serodiagnosis of tuberculosis is of paramount important for the detection of serum antibodies against tuberculosis (TB) and it was considered an easily simple and possible way for improving TB diagnosis. In this work, 70 animals tested positive for TST as well as 20 animals tested negative for TST were used for the diagnosis of BTB depending on humoral immune response based on PPD slide agglutination test using reporter regents (SPA and/or SPG) either native or recombinant. The agglutination density was recorded and read in 4 degrees of positivity with scores ranging from negative (-) to very strong reaction (++++) occurred in different times of agglutination. Groups showed 100% positive reactivates employed in Exp. 1, 2, and 3 with differentiation of slide agglutination test density and was rated from moderate positivity (2+) to very strong (4+), with predominant positivity in density of (3+). Pink-colored intensity is associated with the strengthened reactions between PPD-conjugated Au NPs and serum antibody of each tested samples, which allows for visual rapid, simple, and effective attractive diagnosis of BTB. The specificity and sensitivity of the serological tests were characterized. TST offers the highest sensitivity (83.6%) among the other immunoassays, while the lowest specificity was recorded in TST (57.4%). SPA/SPG offers the best performance in term of combined sensitivity and specificity (performance index) of 175.4. Therefore, the development and uses of detection reagent (such as SPA and/or SPG) slide co-agglutination test (COAT), either native or recombinant (rSPA/SPG) for the detection of TB antibodies based on PPD antigen, as well as the uses of Au NPs rSPA/SPG as detection conjugate based on the same antigen, were also performed as a simple, rapid, sensitive, specific, eco-friendly, and low cost, which shows a great potential in field and lab diagnosis of BTB. So, high reduction in reagents that yields reactions similarly as traditional techniques was needed.
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