Environmental Science and Pollution Research - In the present study, the concentration levels of heavy metals such as Mn, Fe, Ni, Cu, Zn, Cr, and Pb in sediment samples collected from 16 sampling... 相似文献
This paper analyzes the impact of international oil price uncertainty on the different economic sectors (primary, secondary, and tertiary) in Mexico in the period 1993:1–2020:4 through a bivariate structural vector autoregressive (VAR) model with a generalized autoregressive conditional heteroskedasticity (GARCH) in mean to capture the impact of oil volatility on economic growth at the sectoral level of economic activity. The results show that the uncertainty of the international price of oil has a differentiated effect on the different sectors of economic activity in Mexico since it does not influence the primary sector; it negatively impacts the secondary sector, and there is mixed evidence in the tertiary sector. Additionally, evidence is provided that both positive and negative shocks to the international oil price have asymmetric effects at the sectoral level in Mexico. The results highlight the need to implement public policies, at the country level, that help mitigate the effect of uncertainty in the oil market and promote economic stability at the sector level.
Bacteria from the genus Shewanella are inhabitants of marine and freshwater ecosystems, recognized fish spoilage bacteria, but less known as fish disease agents. Shewanella spp. isolated from fish living in waters close to effluents of a wastewater treatment plant (WWTP) were not previously characterized. We have tested Shewanella isolates from WWTP-affected waters and related fish. Genotypic characterization identified most strains as S. baltica and S. oneidensis. In order to investigate the sensibility and accuracy of their MALDI-TOF MS identification, they were grown on two culture media enriched by various NaCl concentrations, incubated at different temperatures and duration. We analyzed their antimicrobial susceptibility on a panel of antimicrobial drugs and capacity for biofilm production. With a view to demonstrate their capacity to produce fatty acids, we assessed the impact of different culture media on their lipid profile. We performed zebrafish embryotoxicity tests to simulate the environmental infection of the earliest life stages in S. baltica-contaminated waters. The best MALDI-TOF MS identification scores were for strains cultivated on TSA for 24 h at 22 °C and with supplementation of 1.5% NaCl. Less than 17% of isolates demonstrated antimicrobial resistance. Most isolates were weak biofilm producers. Strain-to-strain variation of MIC and MBC was low. The major fatty acids were C15:0, C16:0, C16:1, C17:1, and iC15:0. Exposure of Danio rerio to different S. baltica concentrations induced severe effects on zebrafish development: decreased heartbeat rate, locomotor activity, and melanin pigmentation. S. baltica passed through chorionic pores of zebrafish.
Environmental Science and Pollution Research - Páramos are high mountain ecosystems strategic for water provision in South America. Currently, páramos are under threat due to agricultural... 相似文献
Environmental Modeling & Assessment - The São Francisco River Basin plays a critical role in the hydroelectrical operational planning of Brazil. Understanding the hydroclimatic dynamic... 相似文献
Journal of Polymers and the Environment - High-amylose maize starch (AS) was modified by graft copolymerization with sodium acid maleate and disodium maleate, using the KMnO4-NaHSO3 redox system,... 相似文献
Environment Systems and Decisions - Early warning systems for weather events are becoming widespread as technological capacities develop. For warnings to be effective, they must allow enough lead... 相似文献
Pharmaceuticals and illicit drugs are contaminants that are generally ubiquitous in wastewater treatment plant effluents with their release into the environment being well understood in North America, Europe, and Asia. There is, however, less information on the release of human pharmaceuticals and illicit drugs from regions undergoing rapid land use, economical, and social changes, such as Brazil. This encompasses many areas in the tropical zone where releases of emerging contaminants may impact pristine, bio‐diversity rich ecosystems. In this study, the occurrence of human pharmaceuticals and the illicit drug cocaine was determined in the Rio Negro and two of its tributaries that receive large amounts of untreated sewage, the Igarapé Mindu and the Igarapé do 40, passing through the city of Manaus, Brazil. In addition to cocaine and its metabolite, benzoylecognine, propranolol, diclofenac, amitriptyline, carbamazepine, carbamazepine‐epoxide, citalopram, metoprolol, carisoprolol, and sertraline were all detected in two urban tributaries at low ng/l concentrations similar to those typically found in urban surface waters. Concentrations in the Rio Negro were typically lower than detection limits due to the large level of dilution, although traces of a range of pharmaceuticals were detected in the Rio Negro in proximity of the confluence of the urban streams. The data represent new information on the emissions of pharmaceuticals from a newly industrialized region of Brazil. 相似文献