872 research outputs found

    Water Use Efficiency and Land Cover Variability on a Native Grassland Ranch on the Pampa Biome of Uruguay

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    Global efforts towards sustainable cattle ranching should be based on comprehensive approaches, targeting physical variables of the ranching process, as well as, the socioeconomic dimensions. Alianza del Pastizal is a non-profit conservation organization that works to preserve the temperate grasslands of the Southern Cone of South America by promoting conservation practices among ranching communities in Uruguay, Paraguay, Argentina, and Brazil. Alianza has become a mediator for ranchers exchanging information, resources, and education. Ranchers associated with the Alliance take pride in their property management as they aim to improve the community wellbeing and natural resource sustainability. In a previous study, producers from the four countries in the Alliance engaged in focus groups and participatory workshops where they identified water cycle regulation and water quality, as the most important ecosystem services provided by natural grasslands on their properties. With this information, our ultimate goal is to determine if the producers actual land use management activities align with the importance they placed on water. For this purpose, we chose the properties located in the floodplain of the Queguay River, northwestern Uruguay. We used a Google Earth Engine platform to inventory the vegetation types and corresponding Water Use Efficiency (WUE) values per vegetation type in the Colonia Juan Gutierrez. Our results indicate the presence of various vegetation types in the Colonia properties, which follow the seasonal rainfall and temperature patterns of the region, and display variability in WUE values. We plan to carry out the same analysis in the Rincon de Perez conservation area, and the managed forests west of the Colonia. Ultimately, we plan to compare these results to properties that do not subscribe to the Alianza’s ideas to determine whether the stated preferences of Alianza ranchers align with differences in practice that improve environmental outcomes

    Dispersion of hazardous nanoparticles on beaches around phosphogypsum factories

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    Anthropogenic occurring nanoparticles (NPs) have been one of the principal catalytic components of marine pollution throughout its history. The phosphogypsum (PG) factories present environmental risks and evident marine pollution in different parts of the world. Many of these factors continue to operate, however, some have already been abandoned by the private sector. The general objective of this manuscript is to analyze the real nanoparticles (NPs) present on a beach in southern Brazil to illustrate the need to create public policies and projects for environmental recovery. This work focused on real representative sampling of suspended sediments (SSs), and on a modern analytical procedure via advanced electron microscopes (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM coupled with an energy dispersive X-ray microanalysis system-EDS) to analyze NPs containing hazardous elements (HEs). The results presented in this work demonstrate who the size, morphology, among other physical-geochemical characteristics influence in the adsorption of HEs by the NPs and their respective agglomerates. This study is of great importance for carrying out the application of advanced techniques and methods to better understand the formation and transport of NPs on beaches, which allows assisting in the management of waste from plaster factories on a global scale

    Nanoparticles as vectors of other contaminants in estuarine suspended sediments: Natural and real conditions

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    Studding the behaviour and danger of nanoparticles (NPs, minerals and amorphous phases) in the estuarine ecosystem is presently incomplete by the lack of measureable description of NPs in the ecological conditions, such as suspended-sediments (SS). In the last years, several works have revealed the toxic consequences of ultra-fine and nanoparticulate compounds on diverse systems, raising apprehensions over the nanocontaminants behaviour and destiny in the numerous ecological partitions. The general objective of the manuscript is to explain the geochemical conditions of the LES (Laguna estuarine system, southern Brazil) suspended sediments covering an area around the main South American coal plant, enhancing the creation of future public policies for environmental recovery projects. Subsequently the discharge of nanoparticles and toxic element (TE) in the ecosystem, NPs react with several constituents of the nature and suffers active alteration progressions. Contamination coming from engineering actions, wastewater, are something identifiable, however when these contaminations are accompanied by other contamination sources (e.g. mining and farming) the work gets defaulted. By combining material about the concentration of TE contaminants and NPs occurrences, this work offers novel visions into contaminant contact and the possible effects of such exposure on estuarine systems in Brazil. The results presented here will be useful for different areas of estuaries around the world

    Sugarcane straw polyphenols as potential food and nutraceutical ingredient

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    The sugarcane processing industry generates a large amount of straw, which has a negative environmental impact, and high costs are associated with their elimination, wasting their potential bioactive value attributed to their richness in polyphenols. In this study, an ethanolic extract produced from sugarcane straw was screened for its phenolic compounds content, and the potential use of this extract in the development of a food ingredient was further evaluated. Fifty different secondary metabolites belonging to the hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids were identified by liquid chromatography–electrospray ionization–ultrahigh-resolution—quadrupole time of flight–mass spectrometry (LC-ESI-UHR-QqTOF-MS). The predominant phenolic compounds found were 4-hydroxybenzaldehyde, chlorogenic acid, and 5-O-feruloylquinic acid. The obtained extracts showed strong potential as food preservatives by exhibiting (a) antioxidant activity using both 2.2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt radical cation (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods; and (b) antimicrobial capacity, with a minimum inhibitory concentration of 50 mg/mL for Staphylococcus aureus, 74% inhibition for Bacillus cereus, and 44% for Salmonella enterica; and (c) the capacity to inhibit a food browning enzyme, tyrosinase (28–73% for 1–8 mg/ mL). Moreover, the extracts showed antidiabetic potential by inhibiting the enzymes α-glucosidase (15–38% for 1.25–5.00 mg/mL) and dipeptidyl peptidase-IV (DPP-IV) (62–114% for 0.31–5.00 mg/mL). The extract (0.625 mg/mL) also exhibited the capacity to reduce proinflammatory mediators (i.e., interleukins 6 and 8, and tumor necrosis factor alpha) when Caco-2 cells were stimulated with interleukin 1 beta. Thus, sugarcane straw extract, which is rich in phenolic compounds, showed high potential to be used in the development of food-preservative ingredients owing to its antioxidant and antimicrobial potential, and to be explored as a food supplement in diabetes prevention and as coadjuvant to reduce intestinal inflammation by reducing proinflammatory mediators.info:eu-repo/semantics/publishedVersio

    Functionalised collagen-MnO2 fibres inhibit oxidative-induced apoptosis in degenerated IVD

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    Intervertebral disc cell apoptosis has been reported as the major factor responsible in promoting disc degeneration. In this study we hypothesize that collagen fibres with manganese dioxide (MnO2) nanoparticles (NPs) can increase oxygen levels by scavenging ROS species and converting it into byproducts. The specific objective of this study is to fabricate collagen fibres incorporating NPs (Fig. 1), with controlled degradability that are able to scavenge ROS species and generate O2 while inhibiting annulus fibrosus (AF) cell apoptosis under inflamed conditions.Science Foundation Ireland (SFI), the European Regional Development Fund (13/RC/2073)Portuguese Foundation for Science and Technology (SFRH/BD/81356/2011

    Nanoparticles and interfaces with toxic elements in fluvial suspended sediment

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    Studies examining nanoparticles (NPs) and hazardous elements (HEs) contained in suspended sediments (SSs) are vital for watershed administration and ecological impact evaluation. The biochemical consequence of titanium-nanoparticles (Ti-NPs) from SSs in Colombia's Magdalena River was examined utilizing an innovative approach involving nanogeochemistry in this study. In general, the toxicity and the human health risk assessment associated with the presence of some Ti-NPs + HEs in SSs from riverine systems need to be determined with a robust analytical procedure. The mode of occurrence of Ti-NPs, total Ti and other elements contained within SSs of the Magdalena River were evaluated through advanced electron microscopy (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM) coupled with an energy dispersive X-ray microanalysis system (EDS); X-Ray Diffractions (XRD); and inductively coupled plasma-mass spectrometry (ICP-MS). This work showed that enormous quantities of Ti-NPs were present in the river studied and that they displayed diverse geochemical properties and posed various possible ecological dangers. Ti-NP contamination indices must be established for measuring the environmental magnitudes of NP contamination and determining contamination rank among rivers. Finally, SS contamination guidelines must be recommended on an international level. This study contributes to the scientific understanding of the relationship of HE and Ti-NP dynamics from SSs in riverine systems around the world

    Photodegradation of sulfamethoxazole in environmental samples: the role of pH, organic matter and salinity

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    Sulfamethoxazole (SMX) is the most representative antibiotic of the sulfonamides group used in both human and veterinary medicine, and thus frequently detected in water resources. This has caused special concern due to the pronounced toxicity and potential to foster bacterial resistance of this drug. Therefore, and to further understand the fate of SMX in the aquatic environment, its photodegradation under simulated solar radiation was here studied in ultrapure water and in different environmental samples, namely estuarine water, freshwater and wastewater. SMX underwent very fast photodegradation in ultrapure water, presenting a half-life time (t1/2) of 0.86 h. However, in environmental samples, the SMX photodegradation rate was much slower, with 5.4 h < t1/2 < 7.8 h. The main novelty of this work was to prove that pH, salinity and dissolved organic matter are determinant factors in the decrease of the SMX photodegradation rate observed in environmental samples and, thus, they will influence the SMX fate and persistence, potentially increasing the risks associated to the presence of this pollutant in the environment.publishe

    Geochemical study of submicron particulate matter (PM1) in a metropolitan area

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    Air pollution has become a major problem in urban areas due to increasing industrialization and urbanization. In this study ambient concentrations of PM1 and metal concentrations as well as source contributions were identified and quantified by using Positive Matrix Factorization (PMF) in receptor modeling in the Metropolitan Area of Porto Alegre, Brazil. The PM1 samples were collected on PTFE filters from December 2012 to December 2014 in two sampling sites. Major ion and trace element concentrations were assessed. The average concentrations were 12.8 and 15.2 µg/m3 for Canoas and Sapucaia do Sul sites, respectively. Major ion contributions of PM1 were secondary pollutants such as sulfate and nitrate. Trace elements, especially Cu, Pb, Zn, Cd, and Ni also made important contributions which are directly associated with anthropogenic contributions. Our results show significantly higher levels in winter than in summer. Most of the PM1 and the analyzed PM species and elements originated from anthropogenic sources, especially road traffic, combustion processes and industrial activities, which are grouped in 7 major contributing sources. A back-trajectory analysis showed that the long-range transport of pollutants was not relevant in relation to the contribution to PM1 and metal concentrations. This work highlights the importance of urban planning to reduce human health exposure to traffic and industrial emissions, combined with awareness-raising actions for citizens concerning the impact of indoor sources

    An overview of forest residues as promising low-cost adsorbents

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    Anthropogenic activities have severely affected biogeochemical cycles on a global scale, resulting in a drastic increase in environmental problems, intensified by wastewater generation containing high levels of pollutants. As it is known that water is precious yet limited, viable wastewater treatments must be developed. Adsorption is an environmentally friendly option, and it offers the possibility of resolving two problems simultaneously. Besides removing pollutants from water, many adsorbents can be produced using wooden forestry residues. Such materials are generally considered as waste, which leads to their direct disposal. In addition, there are types of wooden forestry waste that have little or no use for humankind, such as fallen leaves or rotten fruits. Therefore, the utilization of wooden forestry residues for preparing low-cost adsorbents is promising. In this review, we briefly approach adsorption advantages to wastewater treatment. Later on, we focus on several types of wooden forestry residues as alternative low-cost adsorbents. © 2021 International Association for Gondwana Research
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