75 research outputs found

    Efficiency of Combined Processes Coagulation/Solar Photo Fenton in the Treatment of Landfill Leachate

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    The combined coagulation-solar photo Fenton treatment of leachate from the sanitary landfill located in Atlantico-Colombia was investigated. Firstly, the efficiency of two alternative combined treatments for the reduction of chemical oxygen demand in leachate was assessed, coagulation with poly-aluminum chloride followed by solar photo-Fenton process (Treatment 1) and coagulation with FeCl3·6H2O followed by ferrioxalate-induced solar photo-Fenton process (Treatment 2). Afterwards, treatments 1 and 2 were compared with the treatment currently used in the sanitary landfill (only coagulation with poly-aluminum chloride), in terms of efficiency and costs. An optimization study of alternative treatments was performed combining central-composite experimental design and response surface methodology. The optimum conditions resulted in a chemical oxygen demand reduction of 73 % and 80 % for Treatment 1 and 2, respectively. Both alternative treatments for the leachate are more efficient than the treatment currently used in the sanitary landfill (chemical oxygen demand reduction of 20 %). In terms of costs, treatment 1 would be the most competitive to implement in the sanitary landfill, since this would have an increase of 13.3 % in the total unitary cost compared to an increase of 39.5 % of treatment 2

    Concentraciones anómalas de oligoelementos contaminantes en aguas subterráneas del partido de José C. Paz, provincia de Buenos Aires, Argentina

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    Los partidos del Área Metropolitana de Buenos Aires se caracterizan por un aumento sostenido en la co ntaminación del agua, que causa serios problemas de salud. A través de un proyecto de investigación financiado por la Fundación YPF, se aportó al conocimiento del problema en José C. Paz. Los objetivos fueron: determinar los parámetros fisicoquímicos y composición iónica en muestras de agua; establecer concentraciones anómalas de oligoelementos, reconocer procesos para remediación e interesar a docentes y alumnos en investigaciones relevantes. Se analizaron 102 muestras de aguas subterráneas para consumo y superficiales, 10 de ellas por oligoelementos, en un área de 50 km2, resultando: [As]: 0,40-26,9 μg L-1 (mediana=15,5 μg L-1); [Se]: 17,5-39,9 μg L-1 (mediana=27,65 μg L-1) y [Hg]: 0,8-21,8 μg L-1 (mediana= 1,25 μg L-1). Se destaca que el alto pH y los procesos de sorción y desorción en la superficie de minerales loéssicos contribuyen a la concentración de arsénico.The Buenos Aires Metropolitan Area counties are characterized by a steady growth in water pollution, ge nerating serious health problems. Through a research project, financed by YPF Foundation, a better understanding of the problem within José C. Paz County was reached. The objectives were to determine water-samples physicochemical parameters and ionic composition; to establish anomalous oligoelements concentrations in some selected samples, to recognize remediation processes and to interest teachers and students in relevant research. One hundred and two drinking water samples from shallow and deep aquifers and from surface courses were analized, ten of them for oligoelements, in an area of 50 km2; the concentrations being: [As]: 0,40-26,9 μg L-1 (median=15,5 μg L-1); [Se]: 17,5-39,9 μg L-1 (median=27,65μg L-1) and [Hg]: 0,8-21,8 μg L-1 (median= 1,25 μg L-1). Noticeably, the high pH and the surface sorption and desorption processes of loessic minerals, contribute to the arsenic concentration.Universidad Nacional de La Plat

    A GIS-supported Multidisciplinary Database for the Management of UNESCO Global Geoparks: the Courel Mountains Geopark (Spain)

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    [Abstract] The management of a UNESCO Global Geopark (UGGp) requires a vast wealth of miscellaneous scientific knowledge that can be successfully organised using a Geographical Information System (GIS). This paper presents a pragmatic GIS database to assist in the suitable governance of the Courel Mountains UGGp (2017) in Northwest Spain. The database is structured in 66 coverages compiled from public sources and previous works or produced through traditional mapping (combining fieldwork and photointerpretation) and GIS tools. The acquired data was later homogenised and validated by a multidisciplinary team and archived in independent coverages. Forty thematic maps illustrate the broad range of cartographic information included in the GIS database. Among them, 25 basic maps provide an overview of the UGGp and 15 new maps focus on crosscutting and technical issues. All maps illustrate the huge potential of GIS to create new resources combining coverages and adapting the legend according to their purpose and audience. The database facilitates the suitable publishing of consistent outputs (e.g., brochures, books, panels, webpages, web serves), as well as the elaboration of technical data to assist the park management. The database furnishes information on the design of education actions, touristic routes, activities and Geopark facilities. The GIS database is also a supportive tool for scientific research and provides the necessary knowledge to conduct geoconservation actions based on land use, geological hazards and the occurrence of natural and cultural heritages. Altogether, the GIS database constitutes a powerful instrument for policy-making, facilitating the identification and evaluation of alternative strategy plans.This work was developed in the framework of the Scientific Program of the Courel Mountains UGGp with the cooperation of tourism agents (A.M. Arza and A. López), roofing slate quarries (Pizarras de Villarbacú, Pizarras de Quiroga) and local people (M. Reinosa, G. Díaz, O. Álvarez). We are deeply grateful to J.R. Martínez Catalán (Universidad de Salamanca), A. Pérez-Alberti and J. Guitián (both from Universidade de Santiago de Compostela), J.R. Gutiérrez-Marco (ICOG, Universidad Complutense de Madrid/CSIC), J. Vegas (IGME-CSIC), L. González-Menéndez (IGME-CSIC), J.M. García Queijeiro (Universidade de Vigo), L. Santos and A. Grandal-D’Anglade (both from Universidade da Coruña) for their assistance supplying information involved in the database. We thank also E. de Boer for proofreading the article. DB is grant holder of Plan Andaluz de Investigación, Desarrollo e Innovación 2021, funded by Junta de Andalucí

    Corticosteroids and other immunosuppressants for immune-related adverse events and checkpoint inhibitor effectiveness in melanoma

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    Background: Recent studies indicate an association between immunosuppression for immune-related adverse events (irAEs) and impaired survival in patients who received immune checkpoint inhibitors. Whether this is related to corticosteroids or second-line immunosuppressants is unknown. In the largest cohort thus far, we assessed the association of immunosuppressant type and dose with survival in melanoma patients with irAEs. Methods: Patients with advanced melanoma who received immunosuppressants for irAEs induced by first-line anti-PD-1 ± anti-CTLA-4 were included from 18 hospitals worldwide. Associations of cumulative and peak dose corticosteroids and use of second-line immunosuppression with survival from start of immunosuppression were assessed using multivariable Cox proportional hazard regression. Results: Among 606 patients, 404 had anti-PD-1 + anti-CTLA-4-related irAEs and 202 had anti-PD-1-related irAEs. 425 patients (70 %) received corticosteroids only; 181 patients (30 %) additionally received second-line immunosuppressants. Median PFS and OS from starting immunosuppression were 4.5 (95 %CI 3.4–8.1) and 31 (95 %CI 15-not reached) months in patients who received second-line immunosuppressants, and 11 (95 %CI 9.4–14) and 55 (95 %CI 41–not reached) months in patients who did not. High corticosteroid peak dose was associated with worse PFS and OS (HRadj 1.14; 95 %CI 1.01–1.29; HRadj 1.29; 95 %CI 1.12–1.49 for 80vs40mg), while cumulative dose was not. Second-line immunosuppression was associated with worse PFS (HRadj 1.32; 95 %CI 1.02–1.72) and OS (HRadj 1.34; 95 %CI 0.99–1.82) compared with corticosteroids alone. Conclusions: High corticosteroid peak dose and second-line immunosuppressants to treat irAEs are both associated with impaired survival. While immunosuppression is indispensable for treatment of severe irAEs, clinicians should weigh possible detrimental effects on survival against potential disadvantages of undertreatment.</p

    Design of a GIS-database for the management of the Courel Mountains UNESCO Global Geopark (Spain)

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    X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - GasteizSe ha desarrollado una base de datos en un sistema de información geográfica (SIG) para la gestión del Geoparque Mundial de la UNESCO Montañas do Courel (NO de España). El SIG incluye 66 capas de información topográfica, geológica, minera, biológica, arqueológica y etnográfica, que pueden ser combinadas entre sí para elaborar mapas temáticos adaptados a la finalidad y al usuario. Los mapas generados son empleados en actividades de divulgación, en el diseño de cartografías técnicas de apoyo a los gestores del Geoparque, en el desarrollo de estudios científicos y en acciones de geoconservació

    Friedrich Hayek and his visits to Chile

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    F. A. Hayek took two trips to Chile, the first in 1977, the second in 1981. The visits were controversial. On the first trip he met with General Augusto Pinochet, who had led a coup that overthrew Salvador Allende in 1973. During his 1981 visit, Hayek gave interviews that were published in the Chilean newspaper El Mercurio and in which he discussed authoritarian regimes and the problem of unlimited democracy. After each trip, he complained that the western press had painted an unfair picture of the economic situation under the Pinochet regime. Drawing on archival material, interviews, and past research, we provide a full account of this controversial episode in Hayek’s life

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure &lt; 100 mmHg (n = 1127), estimated glomerular filtration rate &lt; 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
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