Short history of spondylus in the South American Pacific: a symbol that returns at present

Las especies de Spondylus constituyen un grupo de moluscos de gran importancia dentro de las culturas americanas desde el tercer milenio a.C. hasta el siglo XVII, recuperando su importancia en las décadas recientes. El presente artículo es una cronología sintética del simbolismo del Spondylus en diferentes culturas del pasado de Suramérica. Mediante la reconstrucción histórica del uso del Spondylus se expone el papel que ha jugado en la historia suramericana, lo cual ha permitido y potenciado la interacción entre diferentes culturas. Hoy en día, sobre todo en Ecuador, ha resurgido el Spondylus como símbolo de gran importancia, suponiendo un vínculo entre regiones y, uniendo las comunidades actuales con su pasado histórico.Spondylus species form a group of mollusks of great importance within American cultures since the third millennium BC until 17th century AD, and have received greater recognition over the last decades. The present article is a synthetic chronology of Spondylus symbolism in different cultures of South America’s past. Through the historical reconstruction of the use of Spondylus, the role played by this mollusk in South American history, which has allowed and enhanced the interaction between different cultures, is exposed. Nowadays, especially in Ecuador, Spondylus has resurfaced as a symbol of great importance, assuming a link between regions and uniting the present communities with their historical past.Fil: Lodeiros Seijo, César. Universidad Tecnica de Manabi; Ecuador. Universidad de Oriente; VenezuelaFil: Santana Cabrera, Jonathan A.. Universidad de Las Palmas de Gran Canaria; EspañaFil: Jaramillo Arango, Antonio. Universidad Nacional Autónoma de México; MéxicoFil: Soria, Rodrigo Gaspar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Marcos, Jorge. Escuela Superior Politécnica del Litoral; Ecuado

Indications, Complications, and Retrievals of Inferior Vena Cava Filters in a Colombian Hospital

Introduction: Inferior vena cava filters are endovascular devices utilized in clinical practice to mitigate the risk of acute venous thromboembolic disease progression to pulmonary embolism in cases of absolute contraindications to anticoagulation. Currently, there are no reports on the experience of using such devices in Colombia. Objective: To assess the indications, practices, retrieval rates, and complications of inferior vena cava filters in a university hospital in Colombia. Methods: A retrospective study was conducted at a tertiary-level university hospital in Colombia. Patients who had undergone inferior vena cava filter implantation were included, with exclusion of those with essential data missing for analysis. Descriptive statistics and Student’s t-test were performed for group comparisons. Results: A total of 196 patients with acute venous thromboembolic disease who had undergone inferior vena cava filter implantation were included. None of the patients received the device as primary prophylaxis. Filter-related complications occurred in 13 patients, and retrieval was considered for 118 patients, of whom 108 retrievals were successful. Among the included oncology patients who received an inferior vena cava filter, 36 underwent retrieval attempts, achieving success in 32 cases (88.8%). Conclusions: This study revealed that the most common indications for inferior vena cava filter implantation were the need for surgery, acute bleeding or bleeding risk, and catheter-guided local thrombolysis. The most frequent complication was acute inferior vena cava thrombosis and filter tilting. Inferior vena cava filter retrieval was successful in the majority of attempted cases

Power Quality Indices Estimation Platform

En este artículo se presenta una plataforma interactiva para la estimación de índices de calidad de la potencia de sistemas eléctricos monofásicos, en conformidad con el estándar IEEE 1459-2010. La plataforma PQanalizador se desarrolló con el objetivo de apoyar actividades de docencia e investigación en calidad de la energía eléctrica. La plataforma estima los índices a partir de señales de voltaje y corriente usando tres diferentes algoritmos basados en la transformada rápida de Fourier (FFT), la transformada Wavelet Packet (WPT) y la metodología de mínimos cuadrados. Los resultados muestran que los algoritmos implementados son eficientes para la estimación de los índices de calidad de la potencia y que la plataforma puede ser usada según los objetivos propuestos.An interactive platform for estimating the quality indices in single phase electric power systems is presented. It meets the IEEE 1459-2010 standard recommendations. The platform was developed in order to support teaching and research activities in electric power quality. The platform estimates the power quality indices from voltage and current signals using three different algorithms based on fast Fourier transform (FFT), wavelet packet transform (WPT) and least squares method. The results show that the algorithms implemented are efficient for estimating the quality indices of the power and the platform can be used according to the objectives established.

Tecnología generada para el cultivo y producción rentable de plátano en la zona cafetera central colombiana: informe técnico resumen

La importanciadel cultivo dél plátano a nivel del Departamento del Quindío y del país en general crece año tras año. Tanto desde el punto de vista social como económico. A pesar de la importancia, su explotación afronta una serie de problemas relacionados con técnicas de producción, que junto con la presencia de plagas y enfermedades influyen preponderantemente no sólo sobre el rendimiento y su calidad; sino también en el incremento de nuevas áreas de siembra.Plátano-Musa sapientu

Pyrolysis of wastewater sludge and composted organic fines from municipal solid waste: laboratory reactor characterisation and product distribution

peer-reviewedSludge from municipal wastewater treatment plants and organic fines from mechanical sorting of municipal solid waste (MSW) are two common widespread waste streams that are becoming increasingly difficult to utilise. Changing perceptions of risk in food production has limited the appeal of sludge use on agricultural land, and outlets via landfilling are diminishing rapidly. These factors have led to interest in thermal conversion technologies whose aim is to recover energy and nutrients from waste while reducing health and environmental risks associated with material re-use. Pyrolysis yields three output products: solid char, liquid oils and gas. Their relative distribution depends on process parameters which can be somewhat optimised depending on the end use of product. The potential of pyrolysis for the conversion of wastewater sludge (SS) and organic fines of MSW(OF) to a combustion gas and a carbon-rich char has been investigated. Pyrolysis of SS and OF was done using a laboratory fixed-bed reactor. Herein, the physical characterisation of the reactor is described, and results on pyrolysis yields are presented. Feedstock and chars have been characterised using standard laboratory methods, and the composition of pyrolysis gases was analysed using micro gas chromatography. Product distribution (char/liquid/gas) from the pyrolysis of sewage sludge and compostedMSWfines at 700°C for 10 min were 45/26/29 and 53/14/33%, respectively. The combustible fractions of pyrolysis gases range from 36 to 54% for SS feedstock and 62 to 72% from OF. The corresponding lower heating value range of sampled gases were 11.8–19.1 and 18.2–21.0 MJ m-3, respectively

Job Vacancies in Colombia : 1976-2012

Based on the counting of Help-wanted advertisements in print newspapers, we present national vacancy indexes and vacancy rates for Colombia. These series will allow tackling a myriad of questions related to the functioning of the labor markets in emerging economies, where such datasets were not available until now.A partir del conteo de avisos clasificados de empleo en los principales periódicos se construye un índice de vacantes y una tasa de vacantes para Colombia. Este es el primer intento de construir series con representatividad nacional y de tal extensión n

Increased power by harmonizing structural MRI site differences with the ComBat batch adjustment method in ENIGMA

A common limitation of neuroimaging studies is their small sample sizes. To overcome this hurdle, the Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) Consortium combines neuroimaging data from many institutions worldwide. However, this introduces heterogeneity due to different scanning devices and sequences. ENIGMA projects commonly address this heterogeneity with random-effects meta-analysis or mixed-effects mega-analysis. Here we tested whether the batch adjustment method, ComBat, can further reduce site-related heterogeneity and thus increase statistical power. We conducted random-effects meta-analyses, mixed-effects mega-analyses and ComBat mega-analyses to compare cortical thickness, surface area and subcortical volumes between 2897 individuals with a diagnosis of schizophrenia and 3141 healthy controls from 33 sites. Specifically, we compared the imaging data between individuals with schizophrenia and healthy controls, covarying for age and sex. The use of ComBat substantially increased the statistical significance of the findings as compared to random-effects meta-analyses. The findings were more similar when comparing ComBat with mixed-effects mega-analysis, although ComBat still slightly increased the statistical significance. ComBat also showed increased statistical power when we repeated the analyses with fewer sites. Results were nearly identical when we applied the ComBat harmonization separately for cortical thickness, cortical surface area and subcortical volumes. Therefore, we recommend applying the ComBat function to attenuate potential effects of site in ENIGMA projects and other multi-site structural imaging work. We provide easy-to-use functions in R that work even if imaging data are partially missing in some brain regions, and they can be trained with one data set and then applied to another (a requirement for some analyses such as machine learning)

Implicaciones metodológicas e inconsistencias de la Tercera Comunicación Nacional sobre Cambio Climático de Colombia

Las Comunicaciones Nacionales sobre Cambio Climático (CNCC) son un mecanismo para que los países informen sus avances en mitigación y adaptación, y constituyen uno de los elementos de base para la política sobre cambio climático a escala nacional. Colombia ha emitido tres CNCC. La tercera plantea un escenario que considera las proyecciones de diversos modelos incluidos en la quinta fase del Proyecto de Comparación de Modelos Acoplados (Coupled Model Intercomparison Project, CMIP), el cual se estima como el promedio de las proyecciones correspondientes a las cuatro trayectorias de concentración representativa (Representative Concentration Pathways,RCP) presentadas en el quinto reporte de evaluación del Panel Intergubernamental sobre Cambio Climático. Cada una de estas RCP representa una trayectoria de concentración de gases de efecto invernadero (GEI) para un escenario particular de crecimiento poblacional, económico y tecnológico que conduce a una posible trayectoria de evolución del sistema climático. En este estudio se comparan las proyecciones presentadas en la Tercera CNCC con las obtenidas directamente de los modelos empleados. Nuestros resultados demuestran que al utilizarse un promedio de RCP se pierden escenarios alternos que podrían ser importantes a la hora de considerar posibles futuros diferentes y anulan la utilidad de plantear diversas trayectorias de emisiones de GEI. Más aun, una comparación entre la Segunda y la Tercera CNCC muestra proyecciones de precipitación opuestas para diferentes regiones del país, lo cual es de particular importancia, pues el escenario de cambio climático planteado en la Tercera CNCC sirve de referencia para la toma de decisiones en materia de cambio climático a nivel nacional