Usability Engineering and PPGIS - Towards a Learning-improving Cycle

July 21 - 2

Automatic detection of early repolarization pattern in ECG signals with waveform prototype-based learning

Abstract. Early repolarization (ER) pattern was considered a benign finding until 2008, when it was associated with sudden cardiac arrest (SCA). Since then, the interest of the medical community on the topic has grown, stating the need to develop methods to detect the pattern and analyze the risk of SCA. This thesis presents an automatic detection method of ER using supervised classification. The novelty of the method lies in the features used to construct the classification models. The features consist of prototypes that are composed by fragments of the ECG signal where the ER pattern is located. Three different classifier models were included and compared: linear discriminant analysis (LDA), k-nearest neighbor (KNN) algorithm and support vector machine (SVM). The method was tested in a dataset of 5676 subjects, manually labeled by an experienced analyst who followed the medical guidelines. The algorithm for the detection of ER is composed of different stages. First, the ECG signals are processed to locate characteristic points and remove unwanted noise. Then, the features are extracted from the signals and the classifiers are trained. Finally, the results are fused and the detection of ER is evaluated. Accuracies of the different classifiers showed results over 90%, demonstrating the discrimitative power of the features between ECG signals with and without the ER pattern. Additionally, dimensionality reduction of the features was implemented with Isomap and generalized regression neural networks (GRNN) without affecting the performance of the method. Moreover, analysis of critical cases that are difficult to label was performed based on the distances to the classifier decision boundary, improving the sensitivity of the detection. Hence, the method presented here could be used to discriminate between ECG signals with and without the ER pattern

Aprovechamiento de residuos industriales para la síntesis de clínker belítico

The synthesis of belite clinker was studied using industrial wastes: paper sludge, cement kiln dust and rice husk ashes, as substitutes for natural raw materials. Wastes were characterized by XRF, XRD and TG analysis. Different formulations were prepared to produce clinker at 1300, 1350 and 1400 °C. The clinker obtained was characterized using optical microscopy, XRD and f-CaO content determined by ethylene glycol method. Finally, the hydration of prepared cements with the clinkers was evaluated by isothermal microcalo­rimetry. It was found that by mixing paper sludge, cement kiln dust and rice husk ashes, it is possible to obtain belite clinker with f-CaO content below 0.5%, in clinkering temperatures between 1350 °C and 1400 °C without the use of natural raw materials. It was found that these cements have a high hydration kinetic, far above the rate of Ordinary Portland Cement, due mainly by the amorphous phase content in clinkers obtained.En el presente trabajo se estudió la síntesis de clínker belítico usando residuos industriales: lodo papelero, polvo de horno de cemento y ceniza de cascarilla de arroz, como sustitutos de las materias primas naturales. Los residuos se caracterizaron mediante FRX, DRX y TGA. Se prepararon formulaciones para producir clínker a 1300, 1350 y 1400 °C. El clínker se caracterizó usando microscopía óptica, DRX y f-CaO. Finalmente, se evaluó la hidratación de cementos preparados a partir de los clínkeres obtenidos. Se encontró que, con lodo papelero, polvo de horno de cemento y ceniza de cascarilla de arroz, es posible obtener clínker belítico con contenidos de f-CaO ≤ 0,5%, a temperaturas entre 1350 y 1400 °C sin el uso de materias primas de origen natural. Se encontró una alta cinética de hidratación, muy por encima de la velocidad de hidratación de un cemento Portland convencional, principal­mente debido al contenido de fase amorfa en los clínkeres obtenidos

Asociación entre incidencia de Tuberculosis e índice de desarrollo humano en 165 países del mundo

Objetivos: Evaluar la relación entre el índice de desarrollo humano (IDH) y la incidencia de tuberculosis (TB) en 165 países del mundo en el período 2005-2011. Materiales y métodos: Se realizó un estudio ecológico para el cual el IDH se obtuvo de la base de datos del Fondo de Naciones Unidas para el Desarrollo (PNUD) y la incidencia de TB del Programa Alto a la TB de la Organización Mundial de la Salud (OMS). Se evaluó la variación anual de las variables y se realizaron modelos de regresión no lineales (exponencial). Resultados. Al analizar los datos con los modelos de regresión no lineal, se observó que los países con mayores tasas de incidencia de TB fueron aquellos con menores valores de IDH, siendo significativa su asociación (p<0,01). De igual forma se observó que en los países, la variación en el tiempo se asoció significativamente con la variación en el IDH. Conclusiones: Se ha encontrado una relación inversa y significativa entre el IDH y la morbilidad por TB en los países estudiados, incluidos tanto los países de mayor carga de enfermedad como los de la región andina en Latinoamérica. Esta información refleja la influencia significativa de indicadores socioeconómicos como el IDH sobre la tasa de incidencia de la TB, especialmente en países endémicos, siendo inversa entre ambos tipos de variables; con el incremento o mejoría del IDH la tasa de incidencia de la enfermedad disminuyó o se encontró siendo significativamente menor.Objectives: Assess relationship between the Human Development Index (HDI) and the incidence of tuberculosis (TB) in 165 countries in the World in the period 2005-2011. Materials and methods. An ecological study was done, using HDI data that were obtained from the United Nations Development Program (UNDP), and the incidence rates from the Stop TB Program of the World Health Organization (WHO). The annual variation of the variables was assessed and non-linear regression models (Exponential), were done. Results. At the non-linear regression models, it was observed that the relationship between epidemiological and HDI was significant, those countries with higher rates presented lower values of HDI (p<0.01). Additionally the variation in time was significantly associated with HDI variation. Conclusions: This information reflect the significant influence of socioeconomical indicators such as the HDI on the TB incidence rates in the World, particularly in endemic countries, being an inverse relationship between both types of variables; with an increase or improvement in the HDI, the disease incidence rate decreased or it is found lower

Barriers to the care of febrile patients in a malaria endemic area : El Bagre (Antioquia, Colombia) 2016.

Objetivo: Identificar limitaciones de los pacientes con síndrome febril agudo para acceder a los servicios de atención institucional, con énfasis en la identificación de barreras de comunicación.Método: Estudio descriptivo que involucra técnicas de investigación cualitativa con pacientes de los servicios de atención de la malaria y con personal asistencial y administrativo del municipio de El Bagre Antioquia, Colombia en el 2016. Se aplicaron encuestas semiestructuradas individuales, entrevistas y grupos focales. Los usuarios señalaron dificultades con el transporte, insuficiente número de citas y falta de personal para acceder a la atención. Resultados: Las dificultades de comunicación se relacionaron con la información suministrada sobre trámites y documentación para asistir a los puestos de salud, poca información sobre el diagnóstico, control y adherencia al tratamiento antimalárico y el no uso de algunos pacientes del español para comunicarse en forma verbal o escrita. Conclusiones: Esto exige crear modelos de salud basados en transformaciones estructurales que abarquen las necesidades de los actores del sistema de salud y las comunidades, permitiendo establecer las bases para un proyecto multicultural de sociedad.Objective: identify constraints of patients with acute febrile syndrome to institutional care services access, emphasizing the identification of communication barriers. Method: this is a descriptive study that involves qualitative research techniques including malaria care service patients as well as assistance and administrative personnel of El Bagre town in Antioquia, Colombia in 2016. Semi-structured individual surveys, interviews and focus groups were used. Results: users listed difficulties including transportation, insufficient number of appointments and absence of personnel to access healthcare. Communication difficulties were related to the information provided in the paperwork and documents filled out to attend healthcare facilities, scarce information about diagnostic, control, and adherence to antimalarial treatment; additionally some patients did not use Spanish to communicate in oral or write form. Conclusion: the creation of health models based on structural transformations that encompass the needs of Healthcare System actors and communities is a must, which allows the establishment of foundations for a multicultural society Project

The Evolution of Citizen Security in Colombia in Times of COVID-19

This technical note examines the impact of the COVID-19 pandemic on crime and law enforcement dynamics in Colombia. The analysis uses administrative data on police reports and arrests for different types of offenses. It applies a “difference-in-differences” model, comparing the number of reports and arrests during the quarantine against their pre-quarantine trend. The results show a marked decline in homicides, motor vehicle theft, and other theft types in the initial weeks of the quarantine. The strong initial declines attenuated over time. The results reveal differences in crime dynamics between different regions of the country. The analysis also shows how COVID-19 modified police activity: arrests for offenses such as homicide and robbery decreased, and arrests due to threats to public health increased. This article contributes to a growing number of studies on the pandemic’s social impact and provides data and tools to inform citizen security and criminal justice policies

Genotoxicidad del agua contaminada por plaguicidas en un área de Antioquia

Objective. Determining genotoxicity of organic extract from water resources contaminated by the pesticides used in agriculture, pig and poultry production in Monterredondo village (Antioquia), as a diagnosis of its quality to understand its influence on these water sources in San Pedro de Los Milagros (Antioquia). Materials and methods. Comet assay was used to establish osmotic fragility of erythrocytes, cell viability and DNA damage in human lymphocytes by incubating of these cells in three samples of water collected from sources in the village of Monterredondo in the laboratory of Biochemistry, Faculty of Medicine of the University Antioquia. Results. Data analysis of the comet’s assay length of the organic extract from the three collected samples, indicates genotoxicity. This effect is dependent on the concentration of the extract and the sampling site (p&lt;0.001). The sample of water from the Hato River shows the highest genotoxic effect at 4 and 37ºC. The water sample, from treatment plant Hacienda La Montaña shows relative high genotoxicity, compared to the sample water taken from Fray Juana river. Conclusions. The analysis of the three water samples, collected in the Monterredondo village, reveals genotoxicity. However, further evaluation on the toxicity grade of the concentrated organic components and the genotoxicity in people who drink it, is suggested.  Objetivo. Determinar genotoxicidad del extracto orgánico de recursos hídricos de la vereda Monterredondo (Antioquia), contaminados por el uso de pesticidas en la agricultura, en la producción porcina y avícola como un diagnóstico de su calidad para entender su influencia en estas fuentes de agua en el municipio de San Pedro de Los Milagros (Antioquia). Materiales y métodos. Se empleó el ensayo cometa para establecer fragilidad osmótica de eritrocitos, viabilidad celular y alteración del ADN de linfocitos humanos al incubar estas células en agua recogida de tres fuentes hídricas de la vereda Monterredondo en el laboratorio de Bioquímica de la Facultad de Medicina de la Universidad de Antioquia. Resultados. El análisis de los datos de la longitud del cometa del extracto orgánico de las tres muestras, indicaron genotoxicidad. Este efecto fue dependiente de la concentración del extracto y del sitio de muestreo (p&lt;0.001). La muestra de agua de la quebrada el Hato, presentó el mayor efecto genotóxico a 4 y 37ºC; la muestra de agua de la planta de tratamiento de la Hacienda La Montaña, presentó una alta genotoxicidad relativa, comparada con la muestra de agua de la quebrada Fray Juana. Conclusiones. El análisis de las tres muestras de agua recogidas en la vereda Monterredondo reveló genotoxicidad. Sin embargo, se sugiere en el futuro evaluar el grado de toxicidad de los componentes orgánicos concentrados y la genotoxicidad en personas que la consumen

Evaluación socioformativa en procesos de formación en línea mediante proyectos formativos

El objetivo del presente estudio es determinar la relación entre un conjunto de variables de la evaluación socioformativa y los proyectos formativos en un posgrado en línea. La metodología que se implementó corresponde a un estudio descriptivo-correlacional con una muestra de 79 participantes de una maestría en línea en donde se correlacionó la evaluación socioformativa mediante problemas de contexto, empleo de rúbricas, autoevaluación y coevaluación en el foro académico, con el impacto de los proyectos formativos que hacen énfasis en la importancia de la colaboración y los procesos de mejoramiento de las evidencias considerando los criterios y las metas de desempeño establecidas. Los principales resultados mostraron que la autoevaluación, la coevaluación, los intentos para resolver el problema del contexto, el número de veces que se mejoró la evidencia y los integrantes que conformaron los equipos para la realización de estas presentaron una correlación significativa con el desempeño reflejado en el promedio académico. Por lo tanto, el proceso de retroalimentación continua mediante la autoevaluación y la coevaluación para la mejora de las evidencias realizadas durante el semestre, así como la colaboración y el apoyo para la resolución de problemas del contexto empleando los proyectos formativos, se asocian con un mejor desempeño académico. Se sugiere nuevos estudios para determinar relaciones de causalidad.L'objectiu del present estudi és determinar la relació entre un conjunt de variables de l'avaluació socioformativa i els projectes formatius en un postgrau en línia. La metodologia que es va implementar correspon a un estudi descriptiu correlacional amb una mostra de 79 participants d'un mestratge en línia on es va correlacionar l'avaluació socioformativa mitjançant problemes del context, l'ocupació de rúbriques, l'autoavaluació i la coavaluació en el fòrum acadèmic, amb l'impacte dels projectes formatius que fan èmfasi en la importància de la col·laboració i els processos de millorament de les evidències considerant els criteris i les metes d'acompliment establerts. Els principals resultats van mostrar que l'autoavaluació, la coavaluació, els intents per resoldre el problema del context, el nombre de vegades que es va millorar l'evidència i els integrants que van conformar els equips per a la realització d'aquestes van presentar una correlació significativa amb l'acompliment reflectit en la mitjana acadèmica. Per tant, el procés de retroalimentació contínua mitjançant l'autoavaluació i la coavaluació per a la millora de les evidències realitzades durant el semestre, així com la col·laboració i el suport per a la resolució de problemes del context emprant els projectes formatius s'associen amb un acompliment acadèmic millor. Se suggereixen nous estudis per determinar relacions de causalitat.The objective of this study is to determine the relationship between a set of variables related to socioformative assessment and training projects in the framework of an online postgraduate degree. The methodology comprised a descriptive correlational study with a sample of 79 participants enrolled in an online master's degree. A socioformative assessment model based on context problems, the use of rubrics, and self-assessment and coassessment schemes in an academic forum is correlated with the impact of training projects which emphasize the importance of collaboration and processes to improve the evidence considering the established criteria and performance goals. The main results show that self-assessment, co-assessment, attempts to solve context problems, the number of times that the evidence was improved and the members of teams that were formed to carry out these tasks were significantly correlated with academic performance as reflected in the grade point average. Therefore, ongoing feedback through self-assessment and co-assessment schemes to improve evidence during the academic term, as well as collaboration and support in solving context problems through training projects are associated with better academic performance. Further studies to determine causal relationships are proposed

Geochemistry and Geochronology of the Guajira Eclogites, northern Colombia : evidence of a metamorphosed primitive Cretaceous Caribbean Island-arc

The chemical composition of eclogites, found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia suggests that these rocks are mainly metamorphosed basaltic andesites. They are depleted in LILE elements compared to MORB, have a negative Nb-anomaly and flat to enriched REE patterns, suggesting that their protoliths evolved in a subduction related tectonic setting. They show island-arc affinities and are similar to primitive islandarc rocks described in the Caribbean. The geochemical characteristics are comparable to low-grade greenschists from the nearby Etpana Terrane, which are interpreted as part of a Cretaceous intra-oceanic arc. These data support evidence that the eclogites and the Etpana terrane rocks formed from the same volcano-sedimentary sequence. Part of this sequence was accreted onto the margin and another was incorporated into the subduction channel and metamorphosed at eclogite facies conditions. 40Ar-39Ar ages of 79.2±1.1Ma and 82.2±2.5Ma determined on white micas, separated from two eclogite samples, are interpreted to be related to the cooling of the main metamorphic event. The formation of a common volcano-sedimentary protolith and subsequent metamorphism of these units record the ongoing Late Cretaceous continental subduction of the South American margin within the Caribbean intra-oceanic arc subduction zone. This gave way to an arc-continent collision between the Caribbean and the South American plates, where this sequence was exhumed after the Campanian

Short communication: Application of site‐level assessment of governance and equity (sage) methodology to a candidate oecm: AndakÍ municipal natural park, caquetÁ, colombia.

Governance is a fundamental aspect and precondition for conservation strategies, such as protected areas or OECMs. A methodology for Site-level Assessment of Governance and Equity (SAGE) has been proposed by IUCN to explore different aspects of governance, based on ten principles. This article describes the application of SAGE to a candidate OECM for what we believe is the first time: the Andakí Municipal Natural Park in the Amazon region of Colombia. The application of SAGE generated useful insights into different aspects of governance, including the importance of good communication and recognising and respecting the rights and responsibilities of different actors. Based on this experience, we believe that the SAGE methodology could be a useful tool not only to identify priorities for improving governance, but also to assess governance and equity in order to evaluate if an area meets the criteria for an OECM that it is governed and managed to achieve sustained and effective contributions to in situ conservation of biodiversity, associated ecosystem functions and services, and cultural, spiritual, socio-economic and other locally relevant values. © 2021, IUCN - International Union for the Conservation of Nature. All rights reserved.This process was made possible with the support of: a) the Local Protected Areas Regional Project implemented by Deutsche Gesellschaft f?r Internationale Zusammenarbeit (GIZ) GmbH, ICLEI ? Local Governments for Sustainability and the International Union for Conservation of Nature (IUCN); Environment ministries in Brazil, Colombia, Ecuador and Peru; commissioned by the German Federal Ministry for the Environment, Nature Protection and Nuclear Safety; b) the project adaptation of the OECM criteria to the Colombian context supported by PPD-GEF-PNUD, and implemented by Resnatur, Instituto Humboldt, Fundaci?n Natura and the Local Protected Areas Project; and c) the EUROCLIMA+ programme supported by Expertise France, GIZ and the International Institute for the Environment and Development (IIED); and d) Thora Amend, Vice Chair, IUCN World Commission on Protected Areas (thematic area: Governance)