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Comprehensive evaluation and prediction of tourism ecological security in droughty area national parks—a case study of Qilian Mountain of Zhangye section, China Texte intégral
2021
Wang, Yi | Wu, Chunshan | Wang, Feifeng | Sun, Qiyuan | Wang, Xuefu | Guo, Shengxiang
Tourism activities have brought overexploitation of natural ecotourism resources and ecological pressure challenge though it exactly contributes to the economic prosperity of a region. Research on tourism ecological safety is of great importance for tourist destinations to balance the relationship between environmental protection and tourism development. Qilian Mountains National Park (QMNP) has a prominent ecological status and is a vital ecological barrier in the northwest of China, which attracts large numbers of tourists every year for its rich tourism resources in the Zhangye (ZY) region. However, there is still a lack of systematic research on the environmental impact of tourism activities and on achieving sustainable development of ecotourism in national parks. We took QMNP-ZY as the study object, establishing the system of indicators based on the PSR model for the comprehensive evaluation of tourism ecological safety and the diagnosis of the main obstacles. Moreover, the autoregressive integrated moving average (ARIMA) model was introduced to forecast the evolutionary trends of tourism ecological security in QMNP-ZY. The results showed that (1) The tourism ecological security composite values of the QMNP-ZY exhibited a “U”-type evolution of “first fall-then rise” feature, and the pressure layer gradually became the dominant factor. (2) For the main barrier factors, there had been a shift from response factors. (3)The output of the ARIMA model demonstrated that the level of tourism ecological security would rise in a short period and then decline a few years later. Especially, the contribution degree of economic to the tourism eco-security development will weaken with the region’s economy growing.
Afficher plus [+] Moins [-]Copper chloride inhibits brush border membrane enzymes, alters antioxidant and metabolic status and damages DNA in rat intestine: a dose-dependent study Texte intégral
2021
Ḥusain, Nāẓim | Hasan, Samra | Khan, Aijaz Ahmed | Mahmood, Riaz
Copper (Cu) is an extensively used heavy metal and an indispensible micronutrient for living beings. However, Cu is also toxic and exerts multiple adverse health effects when humans are exposed to high levels of this metal. We have examined the effect of single acute oral dose of copper chloride (CuCl₂) on parameters of oxidative stress, cellular metabolism, membrane and DNA damage in rat intestine. Adult male Wistar rats were divided into four groups and separately administered a single oral dose of 5, 15, 30 and 40 mg CuCl₂/kg body weight. Rats not administered CuCl₂ served as the control. Oral administration of CuCl₂ led to significant alterations in the activities of metabolic and membrane-bound enzymes; brush border enzymes were inhibited by 45–75% relative to the control set. Inhibition of antioxidant enzymes diminished the metal-reducing and free radical quenching ability of the cells. Oxidative damage caused cellular oxidation of thiols, proteins and lipids. Diphenylamine and comet assays showed that CuCl₂ treatment enhanced DNA damage while DNA-protein crosslinking was also increased in the intestinal cells. Examination of stained sections showed that CuCl₂ treatment led to marked histological changes in the intestine. All the changes seen were in a CuCl₂ dose-dependent manner with more prominent alterations at higher doses of CuCl₂. These results clearly show that oral administration of CuCl₂ results in oxidative damage to the intestine which can impair its digestive and absorptive functions.
Afficher plus [+] Moins [-]Attitudes and Knowledge of the Harmful Effects of Waterpipe Tobacco Smoking among university students: A study from Jordan Texte intégral
2021
Al-Sawalha, Nour A. | Almomani, Basima A. | Al-Shatnawi, Samah F. | Almomani, Bashar N.
Waterpipe tobacco smoking (WTS) is an emerging behavior worldwide, especially among the youth. It continues to spike in the Middle-Eastern region. WTS is associated with many harmful health-related outcomes.Objective: Herein, the attitude, knowledge, and factors affecting the knowledge of university students toward the detrimental effects of WTS were examined. This was a cross-sectional study where university students filled an online questionnaire that was available between October 2019 and May 2020. A total of 966 questionnaires were filled. About 40% of participants were current waterpipe smokers. Around 30% of participants stated that WTS is not addictive, and about third of them indicated that smoking waterpipe is an essential part of social gathering and is socially accepted behavior. Half of participants (55.8%) were knowledgeable about the major harmful consequences of WTS. Older students were more knowledgeable as compared to younger ones. In contrast, students from non-medical colleges and waterpipe smokers were less knowledgeable in comparison to those in medical colleges and non-smokers, respectively. More targeted health campaigns to control the use of WTS among university students should be implemented.
Afficher plus [+] Moins [-]Mobilization and transport of pesticides with runoff and suspended sediment during flooding events in an agricultural catchment of Southern Brazil Texte intégral
2021
Didoné, Elizeu Jonas | Minella, Jean Paolo Gomes | Tiecher, Tales | Zanella, Renato | Prestes, Osmar Damian | Evrard, Olivier
Brazil is one of the largest consumers of pesticides in the world, and these chemicals present a high contamination risk for the country’s water bodies. The mechanisms of mobilization and transport of pesticides from cropland to river systems are controlled by runoff and erosion processes occurring at the catchment scale. In addition to the excessive use of pesticides, the transport processes of these substances are also accelerated by inadequate soil management and the absence of soil conservation measures at the catchment scale. The current research relied on hydrological monitoring to investigate the transport and persistence of pesticides in response to hydrological dynamics. The study was conducted in the Conceição River watershed where runoff and suspended sediment fluxes are continuously monitored at the outlet. This study area is representative of the grain production system in southern Brazil including the application of large amounts of pesticides combined with extensive runoff and erosion problems. Sample collection in the river for pesticide analysis included the analysis of both water and suspended sediment. The sediment deposit analysis was performed in a single location at 4 depths. Results demonstrate the occurrence of pesticides including simazine, 2,4-D, carbendazim, imidacloprid, tebuconazole, propiconazole, tetraconazole, and trifloxystrobin in water, while glyphosate and AMPA were detected in suspended sediments, and AMPA and carbendazim were found in sediment deposits. The study demonstrated the strong dependence of the mechanisms of pesticide mobilization and transport in the catchment with the intra- and interevent variability of hydro-sedimentary processes. Pesticide detections can be related to several factors, including the magnitude of the rainfall event, the period of pesticide application, or the transport of suspended sediment. All these factors are correlated, and the mechanisms of transportation play an important role in the connections between sink and sources. The results suggest that pesticide monitoring should take into account the runoff and erosion pathways in each particular catchment, and it should especially include the monitoring of major rainfall events for identifying and quantifying the occurrence of pesticides in the environment. The transport of pesticides indicates to be potentiated by intensive pesticide use, the magnitude of rainfall-runoff events, and the absence of runoff control measures (e.g., terracing). These results demonstrate that water and soil conservation techniques should be planned and coordinated at the watershed scale to reduce the connectivity of water and sediment flows from agricultural areas to river systems with the implementation of effective runoff control practices. This will control the mobilization agents (runoff), as well as limit the connection between the sources and the water bodies.
Afficher plus [+] Moins [-]Greenspace configuration impact on the urban heat island in the Olympic Area of Beijing Texte intégral
2021
Hu, Yunfeng | Dai, Zhaoxin | Guldmann, Jean-Michel
As urban green spaces have significant cooling effects on the urban heat island (UHI), a precise understanding of these effects is necessary to devise precise greenspace strategies for abating the UHI. This paper explores the impacts of different greenspace (trees, grass, and water) patterns on the UHI in Beijing’s Olympic Area, using different grid cell sizes and spatial statistical models. Greenspace pattern metrics include percent cover, mean patch size (MPS), mean patch shape index (MSI), edge density (ED), and largest percent index (LPI). The results show that different greenspace metrics have varying effects on surface temperature. The spatial error model (SEM) turns out to be a good choice for estimating the relationship between Land Surface Temperature (LST) and the greenspace metrics. The regression coefficients of these metrics vary with grid cell size. Tree and grass edge densities have opposite effects, which suggest that trees should be planted in smaller clusters, whereas grass should be planted in larger and continuous patches in order to reach maximum LST cooling. The optimal grid cell size is in the [120–240 m] range. These findings can help urban planners mitigate the UHI in a city with limited green space availability.
Afficher plus [+] Moins [-]Platinum group elements in atmospheric PM10 particles and dry deposition in France Texte intégral
2021
Omrani, Mehrazin | Goriaux, Mathieu | Jean-Soro, Liliane | Ruban, Véronique
Platinum group elements (PGEs, i.e. platinum, Pt; palladium, Pd; and rhodium, Rh) catalyse over 90% of carbon monoxide, nitrogen oxides and hydrocarbons from combustion residues into water vapour, carbon dioxide and nitrogen in the vehicle’s catalytic converter. But there is a major concern over these metals in the scientific world, since they are emitted by catalytic converters and accumulating in the environment. The distribution of PGEs in PM₁₀ fraction was studied in an open urban site (Nantes, France) and in a tunnel (Paris, France) using low- and high-volume air samplers. PGEs were also investigated in dry deposition particles and deposited dust sampled in the tunnel. Pd occurred at the highest levels in both PM₁₀ and dry deposition samples, followed by Rh and Pt. Maximum concentrations in PM₁₀ fraction were 114 pg m⁻³ for Pd, 14.3 pg m⁻³ for Rh and 3.3 pg m⁻³ for Pt in the urban site (Nantes) and 91 pg m⁻³ for Pd and 16 pg m⁻³ for Rh in the tunnel (Paris). The concentrations for dry depositions in the tunnel were 261 μg kg⁻¹ for Pt, 431 μg kg⁻¹ for Pd and 85 μg kg⁻¹ for Rh. The results on PGEs levels in atmospheric particles and dry depositions are the first data of their kind in France and will provide new insights into the contribution of catalytic converters to the environment. We also observed Pd and Rh being 2 times higher PM₁₀ particles compared to dry depositions, leading us to suggest that particles rich in Pd and Rh are smaller than 10 μm. An overall concentration trend of Pd > Rh > Pt was observed in all samples, showing the replacement of Pt by Pd and Rh in newer catalytic converters.
Afficher plus [+] Moins [-]Effects of fluoride emission on the morphoanatomy of three plant species endemics to Brazil using passive biomonitoring Texte intégral
2021
Gomes, Thamires Fernanda | Lima, Ademir Martins | Marques, Ana Paula Pires | da Silva, Luzimar Campos
Fluoride is the most phytotoxic atmospheric pollutant. The objective of this study was to evaluate the effects of fluoride emissions by an aluminum smelter on three plant species endemics to Brazil, located at Parque Estadual do Itacolomi (PEI). The monitored species were Byrsonima variabilis (Malpighiaceae), Myrceugenia alpigena (Myrtaceae), and Eremanthus erythropappus (Asteraceae), which were monitored during 9 months using passive biomonitoring at five different locations with different distances from the smelter. The monitored species did not show macroscopic phytotoxicity damage to fluoride; however, they did show microscopic damage. The species closer to the smelter presented more severe anatomic damages, such as rupture of cell walls, protoplast retraction, and trichome alterations. Damaged stomatal ledges, flaking epicuticular wax, and damages to trichomes were observed. M. alpigena showed a higher accumulation of fluoride than the other species at all monitored sites. The test for cell death with Evans Blue was positive for the three studied species. Through biomonitoring in the PEI, we concluded that the emissions from the aluminum smelter affect the native vegetation and that due to the greater accumulation of fluoride and the diversity of microscopic damage in M. alpigena, the use of this species in the monitoring of environments polluted by fluoride is enhanced.
Afficher plus [+] Moins [-]Possibilities of disposing silica fume and waste glass powder, which are environmental wastes, by using as a substitute for Portland cement Texte intégral
2021
Bayraktar, Oguzhan Yavuz
In this study, the possibilities of disposal of environmental waste, silica fume, and waste glass powder as substitutes in the mortar samples in Portland cement were investigated. For this purpose, Portland cement (CEM I), silica fume (SF), waste glass powder (WGP), CEN standard sand, and water were used in mortar production. Additive cements were obtained by using the SF, WGP, and SFWGP substitution methods in Portland cement at the rates of 10, 20, 30, and 40%. The flexural strength, compressive strength, radiation permeability (determination of linear absorption coefficient), high temperature, and alkali-silica reaction (ASR) effect on SF, WGP, and SFWGP were examined and compared with the control PC 42.5R samples. Mortar samples of 40 × 40 × 160 mm size were obtained with the grouts/mortars produced, and the samples were exposed to five temperature effects, namely, 20, 150, 300, 700, and 1000 ° C. Samples kept at 20 ° C are accepted as baseline. A total of 429 samples were studied, including the cooling process in the air (spontaneously in the laboratory, 20 ° C ± 2). After the samples achieved room temperature, flexural and compressive strength tests were carried out at 28 and 90 days. Test results demonstrate that SF, WGP, and SFWGP, which are environmental wastes, can be disposed both as a pozzolanic additive material both alone and together in cement mortars, can be utilized in buildings with high fire hazard, and the sample with the highest linear absorption coefficient is the sample obtained with SFWGP, and also, the expansion values that occur in SF and WGP are less than the control sample.
Afficher plus [+] Moins [-]Potential therapeutic effect of Chrysopogon zizanioides (Vetiver) as an anti-inflammatory agent Texte intégral
2021
Grover, Madhuri | Behl, Tapan | Bungau, Simona | Aleya, Lotfi
Vetiver has a broad history of traditional medicinal uses, but only a handful of research article has reported its utility in treating diseases. But unfortunately, no work has been reported on the anti-inflammatory activity of its plant extract and inflammatory-linked diseases. Hence, the present review focuses on investigating the several presumptions which can be put forward to explain its anti-inflammatory property. Thus, for ensuring the same, all the databases like science direct, PubMed, book chapters, and other authenticated papers were thoroughly studied to present a connection between inflammation and the plant potential. After gaining enough knowledge on pathogenesis of inflammation, it has been observed that the release of mediators from the arachidonic acid metabolism pathway and generation of oxidative and nitrogen species are presented as the main reason for the occurrence of inflammation condition. The stimulation of antioxidant enzyme system network by the plant extract reduces the level of oxidative stress, creating a balance between oxidant and antioxidant system. Moreover, its antimicrobial activity will prevent the biological source of stimulation towards injury and the CNS depressant effect will subside the pain of inflammation. Amalgamating all the factors together, the plant can be utilized as anti-inflammatory can be and also can be proved as a beneficial perspective in the treatment of inflammation-linked disorders.
Afficher plus [+] Moins [-]Petroleum-contaminated soil: using sonolysis to improve mineralization and biodegradation potential of Fenton reaction and ozonolysis process Texte intégral
2021
Testolin, Renan C. | Mater, Luciana | Radetski-Silva, Ramaiana | Sanches-Simões, Eric | Pimentel-Almeida, Wendell | Schmidt, Gabriela T. | Ariente-Neto, Rafael | Corrêa, Albertina X. R. | Somensi, Cleder A. | Radetski, Claudemir M.
The degradation efficiency of the Fenton reaction or ozonolysis (O₃) to treat soil contaminated by crude petroleum was studied in association with the sonolysis process. To quantify oxidation efficiency, total organic carbon (TOC) and chemical oxygen demand (COD) were measured, while biochemical oxygen demand (BOD₅) was measured to estimate biodegradation potential. TOC removal efficiency ranged from 9 to 52% to the Fenton reaction without sonolysis, and 18% and 78% with sonolysis for reagent concentrations of 1% H₂O₂-100 mM Fe²⁺ and 20% H₂O₂-1 mM Fe²⁺, respectively. For ozonolysis (after 10 and 60 min of treatment), the reduction in TOC ranged from 9 to 43% without sonolysis and 15 to 61% with sonolysis. The Fenton reaction without sonolysis increased the biodegradability in relation to the non-oxidized sample by 6% (1% H₂O₂-100 mM Fe²⁺) and 26% (20% H₂O₂-1 mM Fe²⁺), and with sonolysis the corresponding values were 13% and 42%, respectively. The biodegradation potential under ozonolysis without sonolysis increased from 0.18 (10 min of treatment) to 0.38 (30 min of treatment), and with sonolysis these values were 0.26 and 0.58, respectively. Optimization of the remediation processes is essential to determine sequential treatment order and efficiency.
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