59 research outputs found

    Evaluación de sustratos alternativos para el cultivo de miniclavel (Dianthus caryophyllus L.)

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    Desde la década de 1990 los cultivos de clavel en la Sabana de Bogotá se realizan en sustratos diferentes al suelo. El sustrato más utilizado es la cascarilla de arroz tostada pero, por la contaminación ambiental que genera su quemado, el riesgo de escasez y el aumento en su costo, se están buscando alternativas. En este artículo se compararon cuatro materiales que podrían servir como sustratos alternativos a la cascarilla de arroz tostada: cascarilla de arroz cruda y esterilizada, fibra de coco y escorias de carbón. Se determinaron, a lo largo de un año de cultivo, las propiedades fisicoquímicas de los sustratos, la productividad de las plantas, el peso de ramos, el análisis de tejido vegetal y el porcentaje de plantas muertas por Fusarium oxysporum. Los resultados mostraron que existen diferencias significativas entre los materiales evaluados lo que sugiere diferencias en el manejo durante el cultivo. El sustrato que presentó mayor productividad fue la fibra de coco, seguido de la cascarilla de arroz tostada, aunque no se encontraron diferencias en cuanto al peso de los ramos. La incidencia de Fusarium originó una mayor mortalidad de las plantas cultivadas sobre cascarilla de arroz cruda, seguido de la cascarilla de arroz tostada, aunque esta sigue constituyendo una alternativa sanitaria y de productividad viable para la producción de miniclavel, los resultados muestran ventajas en algunos materiales estudiados y que se podrían mejorar las características si se realizan mezclas adecuadas de los mismos, pero debe continuarse en la búsqueda de sustratos alternativos para este importante cultivo

    Whole genome sequencing of Shigella sonnei through PulseNet Latin America and Caribbean: advancing global surveillance of foodborne illnesses

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    Objectives Shigella sonnei is a globally important diarrhoeal pathogen tracked through the surveillance network PulseNet Latin America and Caribbean (PNLA&C), which participates in PulseNet International. PNLA&C laboratories use common molecular techniques to track pathogens causing foodborne illness. We aimed to demonstrate the possibility and advantages of transitioning to whole genome sequencing (WGS) for surveillance within existing networks across a continent where S. sonnei is endemic. Methods We applied WGS to representative archive isolates of S. sonnei (n = 323) from laboratories in nine PNLA&C countries to generate a regional phylogenomic reference for S. sonnei and put this in the global context. We used this reference to contextualise 16 S. sonnei from three Argentinian outbreaks, using locally generated sequence data. Assembled genome sequences were used to predict antimicrobial resistance (AMR) phenotypes and identify AMR determinants. Results S. sonnei isolates clustered in five Latin American sublineages in the global phylogeny, with many (46%, 149 of 323) belonging to previously undescribed sublineages. Predicted multidrug resistance was common (77%, 249 of 323), and clinically relevant differences in AMR were found among sublineages. The regional overview showed that Argentinian outbreak isolates belonged to distinct sublineages and had different epidemiologic origins. Conclusions Latin America contains novel genetic diversity of S. sonnei that is relevant on a global scale and commonly exhibits multidrug resistance. Retrospective passive surveillance with WGS has utility for informing treatment, identifying regionally epidemic sublineages and providing a framework for interpretation of prospective, locally sequenced outbreaks

    Retrieval of optical and microphysical properties of transported Saharan dust over Athens and Granada based on multi-wavelength Raman lidar measurements: Study of the mixing processes

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    In this paper we extract the aerosol microphysical properties for a collection of mineral dust cases measured by multi-wavelength depolarization Raman lidar systems located at the National Technical University of Athens (NTUA, Athens, Greece) and the Andalusian Institute for Earth System Research (IISTA-CEAMA, Granada, Spain). The lidar-based retrievals were carried out with the Spheroidal Inversion eXperiments software tool (SphInX) developed at the University of Potsdam (Germany). The software uses regularized inversion of a two-dimensional enhancement of the Mie model based on the spheroid-particle approximation with the aspect ratio determining the particle shape. The selection of the cases was based on the transport time from the source regions to the measuring sites. The aerosol optical depth as measured by AERONET ranged from 0.27 to 0.54 (at 500 nm) depending on the intensity of each event. Our analysis showed the hourly mean particle linear depolarization ratio and particle lidar ratio values at 532 nm ranging from 11 to 34% and from 42 to 79 sr respectively, depending on the mixing status, the corresponding air mass pathways and their transport time. Cases with shorter transport time showed good agreement in terms of the optical and SphInX-retrieved microphysical properties between Athens and Granada providing a complex refractive index value equal to 1.4 + 0.004i. On the other hand, the results for cases with higher transport time deviated from the aforementioned ones as well as from each other, providing, in particular, an imaginary part of the refractive index ranging from 0.002 to 0.005. Reconstructions of two-dimensional shape-size distributions for each selected layer showed that the dominant effective particle shape was prolate with diverse spherical contributions. The retrieved volume concentrations reflect overall the intensity of the episodes.Spanish Ministry of Sciences, Innovation and Universities through project CGL2016-81092,Spanish Ministry of Education, Culture and Sports through grant FPU14/0368

    Monumental heritage exposure to urban black carbon pollution

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    In this study, aerosol light-absorption measurements obtained at three sites during a winter campaign were used to analyse and identify the major sources of Black Carbon (BC) particles in and around the Alhambra monument, a UNESCO World Heritage Site that receives over 2 million visitors per year. The Conditional Bivariate Probability Function and the Aethalometer model were employed to identify the main sources of BC particles and to estimate the contributions of biomass burning and fossil fuel emissions to the total Equivalent Black Carbon (EBC) concentrations over the monumental complex. Unexpected high levels of EBC were found at the Alhambra, comparable to those measured in relatively polluted European urban areas during winter. EBC concentrations above 3.0 μg/m3, which are associated with unacceptable levels of soiling and negative public reactions, were observed at Alhambra monument on 13 days from 12 October 2015 to 29 February 2016, which can pose a risk to its long-term conservation and may cause negative social and economic impacts. It was found that road traffic emissions from the nearby urban area and access road to the Alhambra were the main sources of BC particles over the monument. However, biomass burning emissions were found to have very small impact on EBC concentrations at the Alhambra. The highest EBC concentrations were observed during an extended stagnant episode associated with persistent high-pressure systems, reflecting the large impact that can have these synoptic conditions on BC over the Alhambra.European Union's Horizon 2020 Research and Innovation Programme under grant agreement No. 654109, ACTRIS-2.Spanish Ministry of Economy and Competitiveness and FEDER through project CGL2013-45410-R, CGL2016-81092-R 598 and CGL2012-30729.Andalusia Regional Government through project P12- RNM-2409 and P12-FQM-1889

    Stellar polytropes and Navarro-Frenk-White halo models: comparison with observations

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    Motivated by the possible conflict between the Navarro-Frenk-White(NFW) model predictions for the dark matter contents of galactic systems and its correlation with baryonic surface density, we will explore an alternative paradigm for the description of dark matter halos. Such an alternative emerges from Tsallis' non-extensive thermodynamics applied to self-gravitating systems and leads to the so-called ``stellar polytrope'' (SP) model. We consider that this could be a better approach to real structures rather than the isothermal model, given the fact that the first one takes into account the non-extensivity of energy and entropy present in these type of systems characterized by long-range interactions. We compare a halo based on the Navarro-Frenk-White (NFW) and one which follows the SP description. Analyzing the dark matter contents estimated by means of global physical parameters of galactic disks, obtained from a sample of actual galaxies, with the ones of the unobserved dark matter halos, we conclude that the SP model is favored over the NFW model in such a comparison.Comment: 21 pages, 4 figures. Accepted for publication in the Journal of Cosmology and Astroparticle Physic

    Salud de los trabajadores

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    Actividad física y su relación con los factores de riesgo cardiovascular de carteros chilenosAnálisis de resultados: riesgos psicosociales en el trabajo Suceso-Istas 21 en Cesfam QuellónAusentismo laboral por enfermedades oftalmológicas, Chile 2009Brote de diarreas por norovirus, posterremoto-tsunami, Constitución, Región del MauleCalidad de vida en profesionales de la salud pública chilenaCaracterización del reposo laboral en personal del SSMN durante el primer semestre de 2010Concentración de nicotina en pelo en trabajadores no fumadores expuestos a humo de tabaco ambientalCondiciones de trabajo y bienestar/malestar docente en profesores de enseñanza media de SantiagoDisfunción auditiva inducida por exposición a xilenoErgonomía aplicada al estudio del síndrome de dolor lumbar en el trabajoEstimación de la frecuencia de factores de riesgo cardiovascular en trabajadores de una empresa mineraExposición a plaguicidas inhibidores de la acetilcolinesterasa en Colombia, 2006-2009Factores de riesgo y daños de salud en conductores de una empresa peruana de transporte terrestre, 2009Las consecuencias de la cultura en salud y seguridad ocupacional en una empresa mineraPercepción de cambios en la práctica médica y estrategias de afrontamientoPercepción de la calidad de vida en la Universidad del BiobíoPesos máximos aceptables para tareas de levantamiento manual de carga en población laboral femeninaRiesgo coronario en trabajadores mineros según la función de Framingham adaptada para la población chilenaTrastornos emocionales y riesgo cardiovascular en trabajadores de la salu

    The World-Class Multiversity: Global commonalities and national characteristics

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    World-Class Universities (WCUs) are nationally embedded comprehensive higher education institutions (HEIs) that are closely engaged in the global knowledge system. The article reviews the conditions of possibility and evolution of WCUs. Three interpretations are used to explain worldwide higher education: neoliberal theory, institutional theory, and critical political economy, which give greater recognition than the other theories to the role of the state and variations between states. World higher education is evolving under conditions of globalization, organizational modernization (the New Public Management), and in some countries, marketization. These larger conditions have become manifest in higher education in three widespread tendencies: massification, the WCU movement, and organizational expansion. The last includes the strengthening of the role of the large multi-disciplinary multi-purpose HEIs ("multiversities"), in the form of both research-intensive WCUs with significant global presence, and other HEIs. The role of binary sector and specialist HEIs has declined. Elite WCUs gain status and strategic advantage in both quantity and quality: through growth and the expansion of scope, and through selectivity and research concentration. The balance between quantity and quality is now resolved at larger average size and broader scope than before. The final section of the article reviews WCUs in China and considers whether they might constitute a distinctive university model

    Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study

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    Background Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8·0 years [IQR 4·2–11·4], 1191 [59·3%] male and 818 [40·7%] female, and 825 [41·1%] White). 680 (33·8%) patients received primary treatment with intravenous immunoglobulin, 698 (34·7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24·2%) with glucocorticoids alone; 59 (2·9%) patients received other combinations, including biologicals, and 85 (4·2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1·09 (95% CI 0·75–1·58; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids and 0·93 (0·58–1·47; corrected p value=1·00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1·04 (95% CI 0·91–1·20; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids, and 0·84 (0·70–1·00; corrected p value=0·22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0·15 [95% CI 0·11–0·20]; p<0·0001) and glucocorticoids alone (0·68 [0·50–0·93]; p=0·014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0·50 [95% CI 0·38–0·67]; p<0·0001) or glucocorticoids alone (0·63 [0·45–0·88]; p=0·0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health
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