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Relationship between energy demand, financial development, and carbon emissions in a panel of 101 countries: “go the extra mile” for sustainable development Full text
2020
Vo, Xuan Vinh | Zaman, Khalid
The objective of the study is to examine the impact of energy demand on carbon emissions in mediation of financial development and economic growth in a panel of 101 countries by using the time series data from 1995 to 2018. The study employed dynamic GMM estimator in order to reduce possible endogeneity in the given model. Further, the study used Granger causality and innovation accounting matrix (IAM) to find the causal relationships and variance error shocks between the variables. The results show that energy demand and FDI inflows increase carbon emissions, while financial development decreases carbon emissions across countries. Moreover, the results confirmed the inverted U-shaped relationship between income and emissions with a turning point of US$43,500. Among 101 countries, only 13 countries hold environmental Kuznets curve (EKC) hypothesis as their per capita income surpassed the stated turning point, while the remaining countries exhibit “race to the bottom” hypothesis. The feedback relationship is established between (i) income and carbon emissions, (ii) money supply and carbon emissions, and (iii) FDI inflows and energy demand across countries, whereas one-way linkages found in (i) carbon emissions to money supply, (ii) energy demand to money supply, (iii) money supply to FDI inflows and income, and (iv) energy demand to income across countries. The IAM analysis shows that energy demand, FDI inflows, and money supply will likely to increase carbon emissions, while money supply will decrease carbon emissions over a time horizon.
Show more [+] Less [-]The total suitability of water yield and carbon sequestration under multi-scenario simulations in the Weihe watershed, China Full text
2020
Zeng, Li | Li, Jing | Qin, Keyu | Liu, Jingya | Zhou, Zixiang | Zhang, Yumeng
Global climate change and national policies play an important role in regional ecosystem services, both of which should be fully considered when exploring their effective use and management. Bayesian belief network (BBN) is often used in complicated system modelling. Using a BBN to construct a network framework of ecosystem services under climate and policy scenarios for exploring the total suitability distribution of ecosystem services is of great significance. In this study, we develop BBN for the total suitability of water yield and carbon sequestration based on hydro-biogeochemical process. And then we predict the probabilities of the total suitability in 2050 through the BBN under multi-scenario simulations accounting for climate change, birth control and carbon tax policies. Finally, total suitability priority regions are mapped, which are synergy development, water yield suitability, carbon sequestration suitability and non-suitability, respectively. Our results indicate forest, cropland, urban area, and grassland have the largest areas under the representative concentration pathway (RCP) 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. The abolition of the one-child policy has led to a significant expansion of urban areas, and the implementation of the carbon tax policy has greatly increased forest areas. Additionally, temperature, Normalized Vegetation Index (NDVI), precipitation and land use are the key driving factors that influence suitability. The suitable priority regions of different alternatives help policy makers consider ecological protection priorities while addressing management options.
Show more [+] Less [-]Characteristics of phosphorus adsorption and desorption in erosive weathered granite area and effects of soil properties Full text
2020
Sun, Tianyu | Deng, Longzhou | Fei, Kai | Zhang, Liping | Fan, Xiaojuan
Highly weathered acidic soils tend to have high phosphorus adsorption rates. Studying the differential phosphorus adsorption and desorption characteristics of these soils is of great significance to improve phosphorus utilization efficiency and reduce soil phosphorus loss in agricultural management. Erosive weathered granite soil (TL-Tillage layer, LL-Laterite layer, and SL-Sand layer) in Anji County, Zhejiang Province were selected for batch experiments and phosphorus fractionation test. The soil properties that are generally considered to have a greater impact on phosphorus adsorption and desorption are also studied. Derived from the Langmuir adsorption isotherm, the maximum absorption capacity (Qₘₐₓ) of phosphorus in TL soil was greater than that in LL and SL soil. With a pH of 4.3–5.0, the three soils have the most phosphorus adsorption. The desorption ratio (Dᵣ) in the SL soil is larger than the LL and TL soil. Six key soil property indicators can fit Qₘₐₓ and Dᵣ values well. Al-P is the main fraction in the phosphorus adsorption-desorption process. The particle size classification (PSC) method can be used to accurately calculate soil-specific surface area. The results of the soil phosphorus adsorption-desorption test can be used as an explanation of the results of artificial rainfall tests. Our results reveal the differential adsorption-desorption mechanism of eroded weathered granite soil, and provide a reference for selecting soil indicators for soil adsorption-desorption studies in different regions.
Show more [+] Less [-]Genotoxicity in the rivers from the Brantas catchment (East Java, Indonesia): occurrence in sediments and effects in Oreochromis niloticus (Linnæus 1758) Full text
2020
Risjani, Yenny | Loppion, Géraldine | Couteau, Jérôme | Yunianta, Yunianta | Widowati, Ita | Hermawati, Alfi | Minier, Christophe
This paper reports the first data from an integrated study investigating genotoxicity in the Brantas River, Java, Indonesia. Results showed that organic sediment extracts from the sites in the Brantas Delta retained genotoxic compounds identified using the SOS Chromotest and that the Aloo River and, to a lesser extent, the Surabaya River were the most contaminated studied sites. This genotoxicity was attributable to compounds that did not require any bioactivation under the test conditions. Occurrence of genotoxic effects was further investigated in erythrocytes from Nile tilapia, Oreochromis niloticus. High numbers of micronuclei were counted, especially in fish sampled in the rivers of the Brantas Delta. Moreover, cytoplasmic alterations which could be indicative of the presence of lipofuscin were found in the cytoplasm of the fish blood cells, especially in fish from the Aloo, Surabaya and Kalimas rivers. Altogether, our data showed that genotoxicity is occurring in fish living in rivers of the delta of the Brantas River and suggest that sediments from these sites may constitute a major source of pollution and hazard for species living or feeding in the area.
Show more [+] Less [-]Curcumin phytosome modulates aluminum-induced hepatotoxicity via regulation of antioxidant, Bcl-2, and caspase-3 in rats Full text
2020
Al-Kahtani, Mohammed | Abdel-Daim, Mohamed M. | Sayed, Amany A. | El-Kott, Attalla | Morsy, Kareem
Increasing entrance of aluminum chloride (AlCl₃) in many fields exposes human beings to its biotoxicity. Thereby, the present study assesses the potential ameliorative role of curcumin phytosome (CP) on AlCl₃-induced hepatotoxicity. Rats were divided into four groups (n = 6): group 1 served as control; group 2 received CP (200 mg CP/kg b.wt) for 21 days; group 3 injected three doses of AlCl₃ (30 mg/kg/body weight) every 5 days intraperitoneally; group 4 received CP for 7 days prior to AlCl₃ and then received CP concurrently with AlCl₃ for another 14 days. AlCl₃ markedly increased (P < 0.05) the concentrations of AST, ALT, ALP, LDH, total bilirubin, and LPO as well as depleted (P < 0.05) albumin, GSH, SOD, and GPx stores in comparison to the control group. These biochemical alterations supported by the lesion observed in histological sections, increasing the expression of caspase-3 and decreasing the expression of Bcl-2. Treatment with CP modulates the hepatic dysfunction, boosting the endogenous antioxidant status, downregulating the expression of caspase-3, and upregulating the expression of Bcl-2. This hepatic ameliorative effect may be mediated by the ability of CP to repair the oxidant/antioxidant equilibrium rather than its ability to suppress apoptosis.
Show more [+] Less [-]Marine alga “Bifurcaria bifurcata”: biosorption of Reactive Blue 19 and methylene blue from aqueous solutions Full text
2020
Bouzikri, Said | Ouasfi, Nadia | Benzidia, Naoual | Salhi, Anas | Bakkas, Salem | Khamliche, Layachi
In this study, we have investigated the removal efficiency of two organic pollutants: methylene blue (MB) and Reactive Blue 19 (RB19) dyes by using a brown marine alga abundantly available on the Moroccan coastlines called Bifurcaria bifurcata (Bif-Bcata). During the experiments that were conducted in batch mode, we have studied the effect of some parameters such as pH, Bif-Bcata mass, contact time, and initial dye concentration in order to optimize the most suitable biosorption conditions. The biosorption tests on Bif-Bcata showed that the equilibrium is reached after 15 min for both dyes MB and RB19. The optimal pH values are 5.6 and 1.0 for MB and RB19, respectively. Kinetic studies revealed that the biosorption of both dyes follows the pseudo-second-order model. The biosorption isotherms demonstrated that the Langmuir model is the most appropriate to describe the biosorption equilibrium for both dyes MB and RB19 with maximum biosorption capacities reaching 2744.5 mg/g for MB and 88.7 mg/g for RB19. According to these results, it is clear that Bif-Bcata can be considered a promising biomaterial to be used as an effective biosorbent for the elimination of cationic and anionic dyes from textile effluents.
Show more [+] Less [-]Ketamine exerts neurotoxic effects on the offspring of pregnant rats via the Wnt/β-catenin pathway Full text
2020
Zhang, Xintong | Zhao, Jinghua | Chang, Tian | Wang, Qi | Liu, Wenhan | Gao, Li
Ketamine is an anesthetic and analgesic drug widely used in clinical anesthesia. To ensure the safety of anesthesia, it is necessary to study its side effects. Pregnancy is a key period for the development and growth of offspring. During this period, the proliferation and differentiation of brain cells and the synaptic formation are easily affected by external stimuli. Therefore, the aim of this study was to evaluate the effect of ketamine. Ketamine anesthesia was administered to rats in the second trimester of pregnancy, and two behavioral tests were performed, including contextual and cued fear conditioning test (CFC) and Morris water maze (MWM). At the end of the behavioral test, Nissl and Golgi staining were used to detect the dendrite density of hippocampal neurons to reveal the effect of maternal ketamine anesthesia on the hippocampus of offspring. Key proteins and their downstream transcription factors in Wnt/β-catenin signaling pathway from the embryonic development to the adulthood were studied. Our results showed that rats receiving maternal ketamine suffered from nerve injury. The density of hippocampal nerves and dendritic spine changed. Some genes related to Wnt/β-catenin pathway and Tcf/Lef were downregulated. In conclusion, maternal anesthesia with ketamine in the second trimester of pregnancy can lead to cognitive memory impairment and neurotoxicity in the hippocampus of offspring through Wnt/ β-catenin signaling pathway.
Show more [+] Less [-]Evaluation of possible molecular toxicity induced by occupational exposure to lead and concomitant effect of smoking Full text
2020
Fouad, Azza Ali | Foda, Nermine Tawfik | Diab, Iman Hassan | Badr El Dine, Fatma Mohamed Magdy | Balah, Manal Ibrahim Fathy
One of the most toxic heavy metals in the environment nowadays is lead (Pb). Even though exposure to lead has been reduced in some developed countries, individuals working in certain occupations are still exposed to lead at dangerous levels. Occupational exposure is of great concern and is also the main cause of lead poisoning. Although experts in various fields have been investigating the toxic effects of lead and its compounds for many years now, the association between chronic lead exposure and geno-toxicity is still an interesting point of research. The study aims to evaluate the possible DNA damage and the oxidative stress status induced by occupational exposure to lead and the role of concomitant smoking. The study was conducted on 60 subjects divided into two groups: an exposed group (40 male workers exposed to lead in their workplaces). This group was further divided into two subgroups; 20 workers were cigarette smokers and the other 20 workers were non-smokers. The other control group consists of 20 healthy males, not exposed to lead and matched by age to the exposed group (10 were smokers and the rest were non-smokers). Venous blood samples were collected from each participant for the determination of the following: blood lead level (BLL), plasma malondialdehyde (MDA) levels, and DNA damage using agarose gel electrophoresis. The exposed workers had significantly higher levels of lead and MDA, as well as a high frequency of DNA fragmentation. Smoking workers showed a greater frequency of DNA fragmentation than non-smokers. A significant relation was revealed between the BLL, as well as the MDA level, and the degree of DNA fragmentation among the lead-exposed workers. The study has shown additional evidence proving the association between Pb exposure and oxidative stress. The results further reinforced the role of cigarette smoking in augmenting such oxidative damage in the Pb-exposed population. However, further studies are recommended to evaluate the effect of cigarette smoking on Pb-exposed workers.
Show more [+] Less [-]Modification of acidic and textural properties of a sulphated zirconia catalyst for efficient conversion of high-density polyethylene into liquid fuel Full text
2020
Almustapha, Muhammad N. | Fārūq, Muḥammad | Mohammed, Misbahu L. | Farhan, Muhammad | Imran, Muhammad | Andresen, John M.
Consumption of plastic has a rapid increase of about 8% per annum and reached to 400 million per tonnes approximately, where about 50% of plastic was disposed after using only once. Different techniques for treating this increased waste faced a number of issues related to cost and environmental and sustainable development. Catalytic conversion has been found as one of the most viable solutions to solve this problem. Sulphated zirconia (SZ) catalyst modified with calcium carbide (CC) was found to improve high-density polyethylene (HDPE) conversion into liquid fuel. The liquid content was improved from 39.0wt% to 66.0wt% at 410 °C. HDPE was converted 100% by weight using, SZ/CC with 66wt% liquid yield as compared to the conversion of approximately 98wt% with about 40wt% only liquid yield for the pure SZ. The composition of hydrocarbon liquid product was significantly changed from paraffin (16%) and aromatic (58%) to olefin (74%) and naphthenic (23%) compounds. This significant increase in liquid was related to changes in the acidic and textural characteristics of the new hybrid catalyst, SZ/CC where the total ammonia desorption of 337.0 μm NH₃/g for the SZ was modified to 23.4 μm NH₃/g for the SZ/CC. Both SZ and SZ/CC catalysts showed characteristics of mesoporous material, where the internal pore volume of SZ had reduced from 0.21 mL/g for SZ to 0.04 mL/g for SZ/CC. Furthermore, XRD analysis indicated the presence of a new compound, CaZrO₃ in the SZ/CC, which confirmed a chemical interaction between the SZ and CC through sintering of ZrO₂ and CaO. Therefore, the SZ/CC catalyst improves the liquid yield significantly and the selectivity towards olefinic and naphthenic compounds.
Show more [+] Less [-]Regional characteristics of cadmium intake in adult residents from the 4th and 5th Chinese Total Diet Study Full text
2020
Xiao, Gexin | Liu, Yang | Dong, Kylie Fei | Lu, Jiang
Cadmium (Cd) is a heavy metal known to be harmful to human health. The aim of this study was to analyze the regional characteristics of dietary Cd intake of adult male residents in different regions of China. The value of this research is to guide regional consumers to minimize Cd intake by adjusting diets for different food categories in various regions. Dietary Cd intake data is used from the 4th and 5th Chinese Total Diet Studies (CTDS). The 4th CTDS collected data from 12 provinces, covering about 50% of the Chinese population. The 5th CTDS collected data from 20 provinces, covering about 67% of the Chinese population. Over 200 kinds of foods were sampled and divided into 13 categories and organized by geographic information system (GIS) mapping. The results showed that firstly, the dietary Cd intake of Chinese residents has increased; secondly, the food groups with the highest Cd intake were cereals and vegetables; and thirdly, the main food group of dietary Cd intake in different regions is presented such as cereals in Sichuan, Jiangxi, Zhejiang, Guangdong, Fujian, and Guangxi and vegetables in Shanghai, Ningxia, and Heilongjiang. Lastly, the food product with the highest dietary Cd intake concentration was found to be nori in 5 provinces. The other notable foods, with Cd intake, included peanuts, rice, squid, cuttlefish, and mushrooms.
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