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Essential oils from Varronia curassavica (Cordiaceae) accessions and their compounds (E)-caryophyllene and α-humulene as an alternative to control Dorymyrmex thoracius (Formicidae: Dolichoderinae)
2019
de Oliveira, Bruna M. S. | Melo, Carlisson R. | Santos, Ane C. C. | Nascimento, Luis F. A. | Nízio, Daniela A. C. | Cristaldo, Paulo F. | Blank, Arie F. | Bacci, Leandro
The process of urbanization of natural environments has dramatically increased the incidence of pest insects. To control these organisms in urban environments, the last decades have been marked by an increase in the use of synthetic insecticides. However, the intensive and indiscriminate use of synthetic insecticides has provoked a series of environmental problems and human health. In this way, the concern and the searching for environmentally safer alternatives for the control of urban pests is increasing. In the present study we evaluated the lethal and sublethal effects of essential oils (EOs) of six accessions of Varronia curassavica (Jacq.) (Cordiaceae) and their constituents (E)-caryophyllene and α-humulene on the ant Dorymyrmex thoracicus Gallardo, 1916 (Formicidae: Dolichoderinae), a species commonly found in urban environments and which can cause damage to human health. Bioassays of fumigation toxicity and locomotor activity in partially treated arenas were performed. The lethal concentrations to kill 50% of the D. thoracicus population ranged from 0.69 to 2.48 μL/L for EOs and from 3.75 to 1.49 μL/L for the (E)-caryophyllene and α-humulene compounds. The survival of the ants exposed to LC₉₅ of the treatments was reduced over time, ranging from 4.2 to 35.6 h to kill 50% of the D. thoracicus population. In general, EOs of V. curassavica caused repellency and affected the locomotor activity of the ants. Our results indicate that EOs of V. curassavica are a promising source for the control of the urban ant D. thoracicus.
Afficher plus [+] Moins [-]Availability of lead in agricultural soils amended with compost of biosolid with wood shavings and yard trimmings
2019
Ferreyroa, Gisele V. | Vergara Cid, Carolina | Verdenelli, Romina A. | Dominchin, María F. | Meriles, José M. | Pignata, María L. | Rodriguez, Judith H.
Lead-polluted agricultural soils are a serious problem for food safety, with organic amendment being a promising mitigation method from the environmental perspective. Therefore, the purpose of this study was to evaluate lead availability and the effectiveness of the application of compost of biosolid with wood shavings and yard trimmings in contaminated soils. The physicochemical (Pb distribution, organic matter, pH, electric conductivity, cation exchange capacity, nitrogen, phosphorus, carbon, carbonates, exchangeable cations, sodium) and biological parameters (the microbial activity obtained by fluorescein diacetate hydrolysis) in Pb-polluted and non-polluted agricultural soils were evaluated after the addition of biosolid with wood shavings and yard trimming compost. Topsoils (lead-polluted and control) were collected in the vicinity of a former battery-recycling plant, amended with compost (0%, 5%, and 10%), and incubated in controlled conditions for 118 days. The results showed that lead availability decreased significantly, and the nutritional quality of the soils increased in the soils amended with 10% of compost. Taken together, the results of the present study indicated that compost amendment could be an effective method for mitigating the negative effects of lead in agricultural soils.
Afficher plus [+] Moins [-]What matters for environmental quality in the Next Eleven Countries: economic growth or income inequality?
2019
Padhan, Hemachandra | Haouas, Ilham | Sahoo, Bhagaban | Heshmati, Almas
This study uses panel data for the period 1971–2013 to explore the implications of growth, wealth disparities, and per capita energy consumption on carbon emissions in a sample of Next Eleven (N-11) countries. It uses the first-generation (Pedroni and Kao) and second-generation (Westerlund) cointegration techniques to highlight a long-run interplay between the selected variables in carbon emission functions for all the N-11 countries. It also analyzes the long-run interactions among the series. Contrastingly, it also shows that economic growth, income inequalities, and per capita energy consumption accelerate CO₂ emissions. Besides examining the effects of wealth disparity square, the study also uses the environmental Kuznets curve hypothesis in the context of the N-11 countries and discusses the policy implications of its findings.
Afficher plus [+] Moins [-]24-Epibrassinolide pre-treatment reduces alkaline-induced oxidative stress in red rice seedlings
2019
Sharma, Mansi | Mahajan, Priyanka | Singh, Harminder Pal | Batish, Daizy Rani | Kohli, Ravinder Kumar
Soil alkalinity caused by salts, such as sodium bicarbonate (NaHCO₃), and the frequently associated waterlogging problems are pervasive in agriculture and have a deleterious impact on crop production. However, various plant growth regulators, including brassinosteroids, are considered to be important against different abiotic stresses experienced by plants due to drought, salinity, and heavy metal stress. We investigated the putative role of 24-epibrassinolide (EBL), an active brassinosteroid, on red rice plants experiencing alkaline stress. Seedlings were pre-treated with 0.01 μM EBL for 30 min and later, exposed to NaHCO₃ (25 mM) and were sampled, 5 days after treatments. Results showed that the pre-treatment of seedlings with EBL under non-stress conditions could promote rice plant growth. Growth parameters including dry weight (DW), root and coleoptile lengths were reduced under alkaline stress, whereas EBL application reduced the level of inhibition, as compared with NaHCO₃ treatment. Enhanced levels of malondialdehyde content, hydrogen peroxide, and superoxide radicals were significantly diminished by EBL pre-treatment. Moreover, pre-treatment of EBL to alkaline-treated rice seedlings largely stimulated the enzymatic activities of ascorbate peroxidase, catalase, and superoxide dismutase. Thus, the results suggest that pre-application of EBL significantly ameliorates alkaline stress in rice.
Afficher plus [+] Moins [-]The impact and mechanism of quaternary ammonium compounds on the transmission of antibiotic resistance genes
2019
Han, Yue | Zhou, Zhen-Chao | Zhu, Lin | Wei, Yuan-Yuan | Feng, Wan-Qiu | Xu, Lan | Liu, Yang | Lin, Ze-Jun | Shuai, Xin-Yi | Zhang, Zhi-Jian | Chen, Hong
The emergence of antibiotic resistance genes (ARGs) in microbes can be largely attributed to the abuse and misuse of antibiotics and biocides. Quaternary ammonium compounds (QACs) have been used worldwide as common disinfectants and detergents; however, their potential impact on the spread and diffusion of ARGs is still unknown. In this study, we detected the QAC resistance gene (qacEΔ1), the 1 integron gene (intI1), and 12 ARGs (sul1, sul2, cfr, cml, fexA, tetA, tetG, tetQ, tetX, ermB, blaTEM, and dfrA1) in 48 water samples from three watersheds by quantitative PCR (qPCR). We investigated the evolution of bacterial antibiotic resistance under QAC and antibiotic environmental pressures by long-term continuous culture. In addition, five QACs were selected to investigate the effect of QAC on the efficiency of conjugation transfer. The changes in bacterial cell membrane and production of reactive oxygen species (ROS) were detected by flow cytometry, revealing the mechanism by which QAC affects the spread of antibiotic resistance. Our results showed that the QAC resistance gene was ubiquitous in watersheds and it had significant correlation with intI1 and seven ARGs (r = 0.999, p < 0.01). QACs could increase the resistance of bacteria to multiple antibiotics. Furthermore, all five QACs promoted the conjugation transfer of the RP4 plasmid; the optimal concentration of QACs was about 10⁻¹–10⁻² mg/L and their transfer efficiencies were between 1.33 × 10⁻⁶ and 8.87 × 10⁻⁵. QACs enhanced membrane permeability of bacterial cells and stimulated bacteria to produce ROS, which potentially promoted the transfer of plasmids between bacteria. In conclusion, this study demonstrated that QACs may facilitate the evolution and gene transfer of antibiotic resistance gene among microbiome.
Afficher plus [+] Moins [-]Modeling long-term performance of full-scale anaerobic expanded granular sludge bed reactor treating confectionery industry wastewater
2019
Dereli, Recep Kaan
Production and consumption of confectionery products, such as chocolate, sugar, and cookies, have increased worldwide. Thus, management and treatment of confectionery effluents, as one of the most important agro-industrial wastewaters, become essential. Confectionery industries produce high-strength and highly biodegradable wastewaters that are appropriate for biological treatment prior to discharge. In this study, long-term dynamic performance of a full-scale anaerobic expanded granular sludge bed (EGSB) reactor treating confectionery effluent was simulated by using Anaerobic Digestion Model No. 1 (ADM1). Substrate fractionation was carried out based on the ADM1 state variables, and then, the model was calibrated with 300 days of operation data. The calibrated model could capture the dynamic performance of the anaerobic reactor for a long validation period of 500 days. Although the reactor was operated under highly fluctuating volumetric loading rates (VLR) between 0.2 and 5 kg chemical oxygen demand (COD)/m³ day, the model results indicated medium to high prediction accuracy for effluent COD, methane generation, total volatile fatty acids (VFA), and pH parameters. Mean relative absolute errors for COD, methane flow, VFA, and pH parameter simulations were 22%, 16%, 29%, and 1%, respectively. The study presents the applicability of ADM1 for full-scale reactors treating industrial wastewaters.
Afficher plus [+] Moins [-]Effects of perinatal dioxin exposure on development of children: a 3-year follow-up study of China cohort
2019
The purpose of this study was to investigate the longitudinal effects of perinatal exposure to dioxin on physical growth in a 3-year follow-up study. In 2015, 27 mother–infant pairs living in an electronic waste (e-waste) dismantling region and 35 pairs living in a control region were enrolled in the present study. Breast milk samples were collected at 4 weeks after birth. Physical growth, including weight, height, and head and chest circumferences, was measured at 6 months and 3 years of age. Dioxin levels in the breast milk were measured by gas chromatography/high-resolution mass spectrometry. Levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin and toxic equivalency values in maternal breast milk of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and PCDDs/PCDFs were significantly higher in women residing in the e-waste dismantling region. In 3-year-old boys, inverse associations were found between height and PCDDs-TEQ. In girls, positive associations were found between height and 2,3,7,8-TetraCDD, PCDDs-TEQ, and PCDDs/PCDFs-TEQ, and for weight and PCDDs-TEQ and PCDDs/PCDFs-TEQ at 3 years of age. In this study, sex-specific differences were observed in children, in whom dioxin exposure decreased growth in boys but increased growth in girls during the first 3 years of life.
Afficher plus [+] Moins [-]Hepatoprotective activity of Uncaria tomentosa extract against sub-chronic exposure to fipronil in male rats
2019
The effects of fipronil (FPN) on the liver of rats were studied. Rats (n = 6) were treated with 9.7 mg/kg (1/10 of FPN LD₅₀), and other rats (n = 6) received 120 mg/kg of 10% Uncaria tomentosa extract, while a mixture of 9.7 mg/kg FPN and 120 mg/kg of 10% Uncaria tomentosa extract were administered orally to the rats (n = 6) daily for 6 weeks. Body, hepatic weights, liver enzymes, and lipid profile were determined. Hepatic activities of MDA, TNO, TAC, TNF-α, and IL-6 in liver homogenate were measured. Immunohistochemistry of NF-kB and liver histopathology were performed. Fipronil-treated rats had a significant (P = 0.02) lower weight gain. Moreover, relative liver weight was significantly (P = 0.003) increased in FPN-treated rats. Rats administrated with FPN exhibited a significantly (P = 0.02) higher liver enzymes and promoted levels of MDA, TNO, TNF-α, and IL-6 (P < 0.0001) than that in the other groups. Immunostaining of NF-κB was increased (P < 0.0001) in FPN-treated rats. Interestingly, Uncaria tomentosa alone or with FPN decreased the liver immunostaining of NF-κB. In conclusion, FPN produced liver injury through lipid peroxidation and stimulation of NF-κB. However, Uncaria tomentosa combated the oxidative stress and liver damage induced by FPN via inhibition of NF-κB.
Afficher plus [+] Moins [-]The content of toxic elements in hair of dairy cows as an indicator of productivity and elemental status of animals
2019
Miroshnikov, Sergey | Zavyalov, Oleg | Frolov, Alexey | Sleptsov, Ivan | Sirazetdinov, Farit | Poberukhin, Mikhail
The study was conducted on a model of dairy cows of the Holstein breed. At the first stage of research, the elemental composition of cow hair was studied (n = 198). Based on this study, the percentile intervals of chemical elements concentrations in hair were established; values of 25 and 75 percentiles were determined, and they were considered as “physiological standard.” At the second stage, the elemental composition of hair from the upper part of withers of highly productive Holstein cows during the period of increasing milk yield was analyzed (n = 47). The elemental composition of biological substrates was studied according to 25 indicators, using the methods of atomic emission and mass spectrometry (AES-ICP and MS-ICP). An assessment of productivity parameters of cows depending on the level of toxic elements in hair revealed a negative statistically significant relationship with the level of lead. Lead content in hair was negatively correlated with the yield of fat (r = − 0.50), protein (r = − 0.37), and dry matter (r = − 0.48) in milk. Based on these data, cows were divided into three groups: group I, with Pb concentration in hair 0.0245–0.0449 mg/g, group II—between 0.0495 and 0.141 mg/kg, and in group III—between 0.145 and 0.247 mg/g. It was established that increasing Pb content decreases daily production of milk fat by 18.8 (P ≤ 0.05) and 25.3% (P ≤ 0.05), protein by 9.7 (P ≤ 0.05) and 10.7% (P ≤ 0.05), and dry matter by 8.0 and 13.0% (P ≤ 0.05) in cows. Average daily milk yield, adjusted for 1% of fat, decreased by 19.2 (P ≤ 0.05) and 25.3% (P ≤ 0.05), respectively. As the concentration of lead in hair increased, the content of toxic elements (Al, As, Cd, Hg, Pb, Sn, Sr) increased from 0.07 to 0.235 mmol/kg in group I, in group II from 0.082 to 0.266 mmol/kg, and in group III—from 0.126 to 0.337 mmol/kg. It was concluded that it is necessary to further study the use of physiological standard indicators of the content of toxic chemical elements in hair of dairy cows to increase productivity and maintain animal health and to create an effective system of individual health monitoring of highly productive cattle.
Afficher plus [+] Moins [-]Variability in Antarctic sea ice from 1998 to 2017
2019
Wu, Zhankai | Wang, Xingdong
This study was based on the daily sea ice concentration data from the NASA Team algorithm from 1998 to 2017. The Antarctic sea ice was analyzed from the total sea ice area (SIA), first-year ice area, and multiyear ice area. On a temporal scale, the changes in sea ice parameters were studied over the whole 20 years. The results showed that the total SIA increased by 0.0087 × 10⁶ km² year⁻¹ (+ 2.08% dec⁻¹) between 1998 and 2017. The multiyear ice area increased by 0.0141 × 10⁶ km² year⁻¹ from 1998 to 2017. The first-year ice area decreased by − 0.0058 × 10⁶ km² year⁻¹ between 1998 and 2017. On a spatial scale, the entire Antarctic was divided into two areas, namely West Antarctica (WA) and East Antarctica (EA), according to the spatial change rate of sea ice concentration. The total sea ice and multiyear ice areas showed a decreasing trend in WA. However, the total SIA and multiyear ice area all showed an increasing trend in EA. Therefore, Antarctic sea ice presented an increasing trend, but there were different trends in WA and EA.
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