131 research outputs found
Wetland-based passive treatment systems for gold ore processing effluents containing residual cyanide, metals and nitrogen species
Gold extraction operations generate a variety of wastes requiring responsible disposal in compliance with current environmental regulations. During recent decades, increased emphasis has been placed on effluent control and treatment, in order to avoid the threat to the environment posed by toxic constituents. In many modern gold mining and ore processing operations, cyanide species are of most immediate concern. Given that natural degradation processes are known to reduce the toxicity of cyanide over time, trials have been made at laboratory and field scales into the feasibility of using wetland-based passive systems as low-cost and environmentally friendly methods for long-term treatment of leachates from closed gold mine tailing disposal facilities. Laboratory experiments on discrete aerobic and anaerobic treatment units supported the development of design parameters for the construction of a field-scale passive system at a gold mine site in northern Spain. An in situ pilot-scale wetland treatment system was designed, constructed and monitored over a nine-month period. Overall, the results suggest that compost-based constructed wetlands are capable of detoxifying cyanidation effluents, removing about 21.6% of dissolved cyanide and 98% of Cu, as well as nitrite and nitrate. Wetland-based passive systems can therefore be considered as a viable technology for removal of residual concentrations of cyanide from leachates emanating from closed gold mine tailing disposal facilities
Hydrochemical characterization of a mine water geothermal energy resource in NW Spain
Abandoned and flooded mine networks provide underground reservoirs of mine water that can be used as a renewable geothermal energy source. A complete hydrochemical characterization of mine water is required to optimally design the geothermal installation, understand the hydraulic behavior of the water in the reservoir and prevent undesired effects such as pipe clogging via mineral precipitation. Water pumped from the Barredo-Figaredo mining reservoir (Asturias, NW Spain), which is currently exploited for geothermal use, has been studied and compared to water from a separate, nearby mountain mine and a river that receives mine water discharge and partially infiltrates into the mine workings. Although the hydrochemistry was altered during the flooding process, the deep mine waters are currently near neutral, net alkaline, high metal waters of Na-HCO3 type. Isotopic values suggest that mine waters are closely related to modern meteoric water, and likely correspond to rapid infiltration. Suspended and dissolved solids, and particularly iron content, of mine water results in some scaling and partial clogging of heat exchangers, but water temperature is stable (22 °C) and increases with depth, so, considering the available flow (> 100 L s− 1), the Barredo-Figaredo mining reservoir represents a sustainable, long-term resource for geothermal use
Evaluación económica de los compromises de Colombia en el marco de COP21
The document presents the economic impacts from the fulfillment of Colombia’s commitment of the Paris Agreement on climate change. The traditional analysis is done with marginal curves of abatement costs. However, this technique has a set of limitations, which can be solved with a computable general equilibrium (CGE) model. Using the CGE for Colombia (MEG4C), the results show that growth rate of GDP would increase by 0.15% annually, for the period 2020-2040. On the other hand, the structural unemployment rate is reduced by the implementation of mitigation measures in the medium and long term. Due to the economic structure and the emissions matrix, the implementation of measures should be associated with energy efficiency in the transport, industrial and residential sectors, which will generate positive impacts on economic growth. © 2017, Universidad de los Andes, Facultad de Economia. All rights reserved
Mineralogical and environmental features of the asturian copper mining district (Spain): A review
High-throughput sequencing reveals genetic determinants associated with antibiotic resistance in Campylobacter spp. from farm-to-fork
[EN]Campylobacter species are one of the most common causative agents of gastroenteritis worldwide. Resistance against quinolone and macrolide antimicrobials, the most commonly used therapeutic options, poses a serious risk for campylobacteriosis treatment. Owing to whole genome sequencing advancements for rapid detection of antimicrobial resistance mechanisms, phenotypic and genotypic resistance trends along the “farm-to-fork” continuum can be determined. Here, we examined the resistance trends in 111 Campylobacter isolates (90 C. jejuni and 21 C. coli) recovered from clinical samples, commercial broiler carcasses and dairy products in Cairo, Egypt. Multidrug resistance (MDR) was observed in 10% of the isolates, mostly from C. coli. The prevalence of MDR was the highest in isolates collected from broiler carcasses (13.3%), followed by clinical isolates (10.5%), and finally isolates from dairy products (4%). The highest proportion of antimicrobial resistance in both species was against quinolones (ciprofloxacin and/or nalidixic acid) (68.4%), followed by tetracycline (51.3%), then erythromycin (12.6%) and aminoglycosides (streptomycin and/or gentamicin) (5.4%). Similar resistance rates were observed for quinolones, tetracycline, and erythromycin among isolates recovered from broiler carcasses and clinical samples highlighting the contribution of food of animal sources to human illness. Significant associations between phenotypic resistance and putative gene mutations was observed, with a high prevalence of the gyrA T86I substitution among quinolone resistant isolates, tet(O), tet (W), and tet(32) among tetracycline resistant isolates, and 23S rRNA A2075G and A2074T mutations among erythromycin resistant isolates. Emergence of resistance was attributed to the dissemination of resistance genes among various lineages, with the dominance of distinctive clones. For example, sub-lineages of CC828 in C. coli and CC21 in C. jejuni and the genetically related clonal complexes ‘CC206 and CC48’ and ‘CC464, CC353, CC354, CC574’, respectively, propagated across different niches sharing semi-homogenous resistance patterns.SIThis work was partially funded by the Zewail City internal research fund (agreement number ZC 004-2019) and joint ASRT-BA research grant (project number 1110) awarded to Dr. Mohamed Elhadidy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Altered microRNAs related to synaptic function as potential plasma biomarkers for Alzheimer's disease
Altres ajuts: This work was supported by grants from , Fundació La Marató TV3 (TV3-2014-3610), CIBERNED (CB06/05/0042 and PI2017/01) to JRA. DSW was supported by the Fundació La Marató TV3. JCS is a recipient of a Ph.D. Fellowship from the Ministerio de Ciencia, Innovación y Universidades. CF is a recipient of a Ph.D. Fellowship from the Department of Biochemistry and Molecular Biology of the Universitat Autònoma de Barcelona.Several evidences suggest that failure of synaptic function occurs at preclinical stages of Alzheimer's disease (AD) preceding neuronal loss and the classical AD pathological hallmarks. Nowadays, there is an urgent need to identify reliable biomarkers that could be obtained with non-invasive methods to improve AD diagnosis at early stages. Here, we have examined plasma levels of a group of miRNAs related to synaptic proteins in a cohort composed of cognitive healthy controls (HC), mild cognitive impairment (MCI) and AD subjects. Plasma and brain levels of miRNAs were analysed in two different cohorts including 38 HC, 26 MCI, 56 AD dementia patients and 27 frontotemporal dementia (FTD) patients. D'Agostino and Pearson and Shapiro-Wilk tests were used to evaluate data normality. miRNA levels between groups were compared using a two-sided nonparametric Mann-Whitney test and sensitivity and specificity was determined by receiver operating characteristic curve analysis. Significant upregulation of miR-92a-3p, miR-181c-5p and miR-210-3p was found in the plasma of both MCI and AD subjects. MCI patients that progress to AD showed higher plasma levels of these miRNAs. By contrast, no changes in miR-92a-3p, miR-181c-5p or miR-210-3p levels were observed in plasma obtained from a cohort of FTD. Our study shows that plasma miR-92a-3p, miR-181c-5p and miR-210-3p constitute a specific molecular signature potentially useful as a potential biomarker for AD. The online version of this article (10.1186/s13195-019-0501-4) contains supplementary material, which is available to authorized users
Proteasomal-Mediated Degradation of AKAP150 Accompanies AMPAR Endocytosis during cLTD
Altres ajuts: This work was partially supported by grants from the Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Grant CB06/05/0042, the Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición Grant CB06/03/0001, Fundació La Marató de TV3 Grants 2014-3610 and 201627.30.31The number and function of synaptic AMPA receptors (AMPARs) tightly regulates excitatory synaptic transmission. Current evidence suggests that AMPARs are inserted into the postsynaptic membrane during long-term potentiation (LTP) and are removed from the membrane during long-term depression (LTD). Dephosphorylation of GluA1 at Ser-845 and enhanced endocytosis are critical events in the modulation of LTD. Moreover, changes in scaffold proteins from the postsynaptic density (PSD) could be also related to AMPAR regulation in LTD. In the present study we analyzed the effect of chemical LTD (cLTD) on A-kinase anchoring protein (AKAP)150 and AMPARs levels in mouse-cultured neurons. We show that cLTD induces AKAP150 protein degradation via proteasome, coinciding with GluA1 dephosphorylation at Ser-845 and endocytosis of GluA1-containing AMPARs. Pharmacological inhibition of proteasome activity, but not phosphatase calcineurin (CaN), reverted cLTD-induced AKAP150 protein degradation. Importantly, AKAP150 silencing induced dephosphorylation of GluA1 Ser-845 and GluA1-AMPARs endocytosis while AKAP150 overexpression blocked cLTD-mediated GluA1-AMPARs endocytosis. Our results provide direct evidence that cLTD-induced AKAP150 degradation by the proteasome contributes to synaptic AMPARs endocytosis
Bluefin tuna (Thunnus thynnus) biomass estimation during transfers using acoustic and optic techniques
Our results show that the use of an acoustic transducer in transfers offers the possibility of performing an automatic counting with error below 10%, which is decreased to 1.2% after improving structure and algorithms. Moreover, the proposed procedure for automatic sizing using stereoscopic system achieved an accurate estimation of SFL distribution compared to true data from harvests, automatically measuring 20% of the fis
Spatial and temporal variations of trace element distribution in soils and street dust of an industrial town in NW Spain: 15years of study
Extensive spatial and temporal surveys, over 15 years, have been conducted in soil in urban parks and street dusts in one of the most polluted cities in western Europe, Avilés (NW Spain). The first survey was carried out in 1996, and since then monitoring has been undertaken every five years. Whilst the sampling site is a relatively small town, industrial activities (mainly the steel industry and Zn and Al metallurgy) and other less significant urban sources, such as traffic, strongly affect the load of heavy metals in the urban aerosol. Elemental tracers have been used to characterise the influence of these sources on the composition of soil and dust. Although PM10 has decreased over these years as a result of environmental measures undertaken in the city, some of the “industrial” elements still remain in concentrations of concern for example, up to 4.6% and 0.5% of Zn in dust and soil, respectively. Spatial trends in metals such as Zn and Cd clearly reflect sources from the processing industries. The concentrations of these elements across Europe have reduced over time, however the most recent results from Avilés revealed an upward trend in concentration for Zn, Cd, Hg and As. A risk assessment of the soil highlighted As as an element of concern since its cancer risk in adults was more than double the value above which regulatory agencies deem it to be unacceptable. If children were considered to be the receptors, then the risk nearly doubles from this element
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