140 research outputs found

    Diseño de un sistema de biofiltración para la remoción de estireno

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    El presente trabajo se enfocó en desarrollar un proceso para la eliminación del gas estireno, un contaminante orgánico generador de malos olores en el aire. Se construyó un sistema de biofiltración en el cual se emplearon bacterias del tipo Pseudomona aeruginosa y Escherichia coli adheridas a un soporte de piedra pómez. Se contaminó aire con estireno en concentraciones por encima del estándar norteamericano (TLV 40 ppm, ACGIH 2002), para simular una atmósfera laboral de alto riesgo a la salud. A fin de evaluar la eficiencia del sistema, se midieron directamente las concentraciones de estireno a la entrada y a la salida, utilizando un medidor de vapores orgánicos. Durante los primeros días se obtuvieron remociones por encima del 55%, para un promedio de 5 mediciones diarias, durante un periodo de 10 días. El sistema se fue estabilizando progresivamente durante la fase inicial, por lo que la remoción no fue la óptima. A partir del día 8 se alcanzaron remociones promedio por encima del 70% y remociones específicas superiores al 90%. El soporte de piedra pómez demostró ser una buena alternativa, facilitando la formación de una biopelícula; la rápida saturación de sus microporos permitió garantizar la baja adsorción del compuesto orgánico en el medio (piedra pómez + microorganismos), confirmando un auténtico proceso de biodegradación.This work was focused on developing an elimination process of styrene, an organic compound generating complex odors in air, through the design and construction of a biofiltration system, utilizing bacteria of the Pseudomona aeruginosa and Escherichia coli types stuck on a pumice stone support. Air was contaminated with styrene, in concentrations above the American Standard (TLV 40 ppm, ACGIH Worldwide, 2002), to simulate a hazardous work environment to the human health. To evaluate the efficiency of the system, the contaminated inlet air as well as the outlet flow were analyzed by taking direct styrene concentrations measurements with an organic vapor meter. Initially, the results obtained from the styrene degradation were above 55%, for a five-daily-sampling average during 10 days. This percentage was a consequence of the progressive stabilization process of the system within the first days, so the removal was low. However, average removals above 70% and punctual removals above 90% were reached after the eighth day. The pumice stone support demonstrated to be a good alternative to improve biofilm formation; the rapid micropore saturation guaranteed low adsorption of the organic compound and confirmed the elimination of styrene via biodegradation

    The VISCACHA survey - I. Overview and first results

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    TheVISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA) Survey is an ongoing project based on deep photometric observations of Magellanic Cloud star clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with the SOAR Adaptive Module Imager. Since 2015 more than 200 h of telescope time were used to observe about 130 stellar clusters, most of them with low mass (M < 104MΘ) and/or located in the outermost regions of the Large Magellanic Cloud and the Small Magellanic Cloud.With this high-quality data set, we homogeneously determine physical properties from statistical analysis of colour-magnitude diagrams, radial density profiles, luminosity functions, and mass functions. Ages, metallicities, reddening, distances, present-day masses, mass function slopes, and structural parameters for these clusters are derived and used as a proxy to investigate the interplay between the environment in theMagellanic Clouds and the evolution of such systems. In this first paper we present the VISCACHA Survey and its initial results, concerning the SMC clusters AM3, K37, HW20, and NGC 796 and the LMC ones KMHK228, OHSC3, SL576, SL61, and SL897, chosen to compose a representative subset of our cluster sample. The project's long-term goals and legacy to the community are also addressed.Fil: Maia, Francisco F. S.. Universidade de Sao Paulo; BrasilFil: Dias, Bruno. Universidad Andrés Bello; Chile. European Southern Observatory Santiago; ChileFil: Santos, Joao F. C.. Universidade Federal de Minas Gerais; BrasilFil: De Kerber, Leandro. Universidade de Sao Paulo; BrasilFil: Bica, Eduardo. Universidade Federal do Rio Grande do Sul; BrasilFil: Piatti, Andres Eduardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barbuy, Beatriz. Universidade de Sao Paulo; BrasilFil: Quint, Bruno. Gemini Observatory; ChileFil: Fraga, Luciano. Laboratório Nacional de Astrofísica; Brasil. Gemini Observatory; ChileFil: Sanmartim, David. Gemini Observatory; ChileFil: Angelo, Mateus S.. Centro Federal de Educação Tecnológica de Minas Gerais; BrasilFil: Hernandez-Jimenez, Jose A.. Universidade de Sao Paulo; BrasilFil: Santrich, Orlando J. Katime. Universidade Estadual de Santa Cruz; BrasilFil: Oliveira, Raphael A. P.. Universidade de Sao Paulo; BrasilFil: Pérez-Villegas, Angeles. Universidade de Sao Paulo; BrasilFil: Souza, Stefano O.. Universidade de Sao Paulo; BrasilFil: Vieira, Rodrigo G.. Universidade de Sao Paulo; BrasilFil: Westera, Pieter. Universidade Federal do ABC; Brasi

    The VISCACHA survey-deep and resolved photometry of star clusters in the Magellanic Clouds

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    The VISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA†) Survey is an ongoing project based on deep and spatially resolved photometric observations of Magellanic Cloud star clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with the SOAR Adaptive Module Imager. So far we have used >300h of telescope time to observe ∼150 star clusters, mostly with low mass (M < 104M⊠) on the outskirts of the LMC and SMC. With this high-quality data set, we homogeneously determine physical properties using deep colour-magnitude diagrams (ages, metallicities, reddening, distances, mass, luminosity and mass functions) and structural parameters (radial density profiles, sizes) for these clusters which are used as a proxy to investigate the interplay between the Magellanic Clouds and their evolution. We present the VISCACHA survey and its initial results, based on our first two papers. The project's long term goals and expected legacy to the community are also addressed.Fil: Dias, Bruno. European Southern Observatory Chile; Chile. Universidad Andrés Bello; ChileFil: Maia, Francisco. Universidade Federal do Rio de Janeiro; BrasilFil: Kerber, Leandro. Universidade Estadual de Santa Cruz; BrasilFil: Dos Santos, João F. C.. Universidade Federal de Minas Gerais; BrasilFil: Bica, Eduardo. Universidade Federal do Rio Grande do Sul; BrasilFil: Armond, Tina. Universidade Federal de São João del Rei; BrasilFil: Barbuy, Beatriz. Universidade de Sao Paulo; BrasilFil: Fraga, Luciano. Laboratório Nacional de Astrofísica; BrasilFil: Hernandez Jimenez, Jose A.. Universidad Andrés Bello; ChileFil: Katime Santrich, Orlando J.. Universidade Estadual de Santa Cruz; BrasilFil: Oliveira, Raphael A. P.. Universidade de Sao Paulo; BrasilFil: Pérez Villegas, Angeles. Universidade de Sao Paulo; BrasilFil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Quint, Bruno. Observatorio Gemini; ChileFil: Sanmartin, David. Observatorio Gemini; ChileFil: Angelo, Mateus S.. Centro Federal de Educação Tecnológica de Minas Gerais; BrasilFil: Souza, Stefano O.. Universidade de Sao Paulo; BrasilFil: Vieira, Rodrigo G.. Universidade de Sao Paulo; BrasilFil: Westera, Pieter. Universidad Federal Do Abc; BrasilFil: Parisi, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Geisler, Doug. Universidad de La Serena; Chile. Universidad de Concepción; ChileFil: Minniti, Dante. Universidad Andrés Bello; Chile. Millennium Institute of Astrophysics; Chile. Vatican Observatory; ItaliaFil: Saito, Roberto. Universidade Federal de Santa Catarina; BrasilFil: Bassino, Lilia Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: de Bórtoli, Bruno Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Figueiredo, André. Universidade de Sao Paulo; BrasilFil: Rímulo, Leandro. Universidad de los Andes; Colombi

    Diagnostic Accuracy of Adenosine Deaminase and Lymphocyte Proportion in Pleural Fluid for Tuberculous Pleurisy in Different Prevalence Scenarios

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    BACKGROUND: Tuberculous pleural effusion (TPE) is a paucibacillary manifestation of tuberculosis, so isolation of Mycobacterium tuberculosis is difficult, biomarkers being an alternative for diagnosis. Adenosine deaminase (ADA) is the most cost-effective pleural fluid marker and is routinely used in high prevalence settings, whereas its value is questioned in areas with low prevalence. The lymphocyte proportion (LP) is known to increase the specificity of ADA for this diagnosis. We analyse the diagnostic usefulness of ADA alone and the combination of ADA ≥ 40 U/l (ADA(40)) and LP ≥ 50% (LP(50)) in three different prevalence scenarios over 11 years in our area. MATERIALS AND METHODS: Biochemistry, cytology and microbiology studies from 472 consecutive pleural fluid samples were retrospectively analyzed. ADA and differential cell count were determined in all samples. We established three different prevalence periods, based on percentage of pleural effusion cases diagnosed as tuberculosis: 1998-2000 (31.3%), 2001-2004 (11.8%), and 2005-2008 (7.4%). ROC curves, dispersion diagrams and pre/post-test probability graphs were produced. TPE accounted for 73 episodes (mean prevalence: 15.5%). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for ADA(40) were 89%, 92.7%, 69.2% and 97.9%, respectively. For ADA(40)+LP(50) the specificity and PPV increased (98.3% and 90%) with hardly any decrease in the sensitivity or NPV (86.3% and 97.5%). No relevant differences were observed between the three study periods. CONCLUSIONS/SIGNIFICANCE: ADA remains useful for the diagnosis of TPE even in low-to-intermediate prevalence scenarios when combined with the lymphocyte proportion

    Cardiovascular risk factors in patients with spondyloarthritis from Northern European and Mediterranean countries: An ancillary study of the ASAS-COMOSPA project

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    Objectives: The objectives of this study were: (1) to compare the prevalence of cardiovascular disease and cardiovascular risk factors among different phenotypes of spondyloarthritis (SpA); (2) to assess the differences in cardiovascular disease and cardiovascular risk factors between two geographical areas, i.e. Northern Europe vs. Mediterranean region; (3) to identify potential predictive factors for high Framingham Risk Score regarding disease features in SpA and geographical area. Methods: Ancillary analysis of the international, multicentric, observational, cross-sectional ASAS-COMOSPA study. Cardiovascular disease and cardiovascular risk factors were compared depending on SpA phenotype and geographical regions. Potential factors associated with higher cardiovascular risk (i.e. Framingham Risk Score) were determined by a multiple logistic regression. Results: The most frequent cardiovascular risk factor and cardiovascular disease were smoking (31.2%) and ischemic heart disease (3.2%), respectively. Regarding SpA phenotype, axial SpA patients showed significantly lower prevalence (P < 0.05) of hypertension (19.2% vs. 33.8% vs. 26.6% for axial, peripheral and mixed phenotypes, respectively), type 2 diabetes mellitus (4.3% vs. 8.5% vs. 7.4%), dyslipidemia (13.9% vs. 28.4% vs. 15.2%) and ischemic heart disease (2.4% vs. 7.0% vs. 3.2%). Regarding geographical area, a higher frequency of hypertension (34.7% vs. 19.4%,), dyslipidemia (19.3% vs. 14.4%), obesity (29.3% vs. 20.7%) and ischemic heart disease (6.2% vs. 1.8%) was observed for Northern Europe vs. Mediterranean Region, respectively. Conclusions: Our results suggest that SpA phenotype and geographical area are associated with the prevalence of cardiovascular risk factors and the cardiovascular risk itself, observed in patients in the ASAS-COMOSPA cohort

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    A Gap Analysis Methodology for Collecting Crop Genepools: A Case Study with Phaseolus Beans

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    Background The wild relatives of crops represent a major source of valuable traits for crop improvement. These resources are threatened by habitat destruction, land use changes, and other factors, requiring their urgent collection and long-term availability for research and breeding from ex situ collections. We propose a method to identify gaps in ex situ collections (i.e. gap analysis) of crop wild relatives as a means to guide efficient and effective collecting activities. Methodology/Principal Findings The methodology prioritizes among taxa based on a combination of sampling, geographic, and environmental gaps. We apply the gap analysis methodology to wild taxa of the Phaseolus genepool. Of 85 taxa, 48 (56.5%) are assigned high priority for collecting due to lack of, or under-representation, in genebanks, 17 taxa are given medium priority for collecting, 15 low priority, and 5 species are assessed as adequately represented in ex situ collections. Gap “hotspots”, representing priority target areas for collecting, are concentrated in central Mexico, although the narrow endemic nature of a suite of priority species adds a number of specific additional regions to spatial collecting priorities. Conclusions/Significance Results of the gap analysis method mostly align very well with expert opinion of gaps in ex situ collections, with only a few exceptions. A more detailed prioritization of taxa and geographic areas for collection can be achieved by including in the analysis predictive threat factors, such as climate change or habitat destruction, or by adding additional prioritization filters, such as the degree of relatedness to cultivated species (i.e. ease of use in crop breeding). Furthermore, results for multiple crop genepools may be overlaid, which would allow a global analysis of gaps in ex situ collections of the world's plant genetic resource
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