A Virtual Element Method for a Nonlocal FitzHugh-Nagumo Model of Cardiac Electrophysiology

We present a Virtual Element Method (VEM) for a nonlocal reaction-diffusion system of the cardiac electric field. To this system, we analyze an $H^1(\Omega)$-conforming discretization by means of VEM which can make use of general polygonal meshes. Under standard assumptions on the computational domain, we establish the convergence of the discrete solution by considering a series of a priori estimates and by using a general $L^p$ compactness criterion. Moreover, we obtain optimal order space-time error estimates in the $L^2$ norm. Finally, we report some numerical tests supporting the theoretical results

Migration, cultural management and social inclusion in Costa Rica

La Gestión Cultural constituye una disciplina en pleno proceso de expansión, capaz de generar un liderazgo en el desarrollo de estrategias creativas para el fomento del diálogo intercultural y del desarrollo humano. En Costa Rica, las técnicas de la Gestión Cultural han sido esenciales para desarrollar las estrategias de integración social de migrantes, refugiados y nacionales, liderado por el Ministerio de Gobernación y Policía. El artículo explora la experiencia desarrollada sobre este particular en Costa Rica, y facilita la visibilización de nuevos campos de desarrollo de la disciplina para los años venideros.Cultural Management is a discipline at the height of an expansion process, capable of becoming a leader in the development of creative strategies to foment intercultural dialogue and human development. In Costa Rica, Cultural Management techniques have been essential in the development of social integration strategies for migrants, refugees and nationals, led by the Ministry of Governance and Police. The article explores the experiences gained on this subject in Costa Rica, and facilitates making new fields of development in the discipline more visible in coming years

The role of penetrative deformation in orogenic processes. An example from the Eastern Cordillera of Colombia

The Lower Cretaceous units of the Eastern Cordillera of Colombia have been deposited during a stage when the area where nowadays lies a contractional orogen was an actively deforming rift. Therefore, they are syn-rift sedimentary units. These rocks have a unique feature in the Cretaceous sedimentary column of this mountain chain. This is a widespread planar fabric expressed mostly as a penetrative slaty cleavage. This planar fabric is only macroscopically evident in Cretaceous units older than Barremian. Planar fabric (e.g. slaty cleavage) is one of the products of internal or penetrative deformation (i.e. contractional deformation at microscopical scale in rock units). Pressure solution and even cleavage have been recently reported in areas undergoing only subtle burials (Engelder & Marschak 1985). However, in the Eastern Cordillera, the units where planar fabric is evident are the base of a sequence of at least 5km and they have vitrinite reflectance values up to 2. These data and the formation of clorithoid contemporary with the slaty cleavage, allow us to propose that this planar fabric was developed when the Lower Cretaceous units had an amount of overburden close to the thickness of the entire Cretaceous sequence...conferenc

La Bolsa de Valores de Colombia. Su historia y relación con la Universidad EAFIT

The Colombian Securities Exchange Market has undergone through many stages and has been handled by diverse institutions, which have born and disappeared over the years according to the changing environment. A century passed since the creation of the first stock market in the country until the Bolsa de Valores de Colombia was born as a result of the unification of the Colombian Securities Exchange Markets. A century of history that is described in a detailed form. For the development of Capital Markets in Colombia and its Securities Exchange Market, the support of academics has been crucial, and EAFIT University has been a fundamental actor in this process.El Mercado Público de Valores en Colombia ha pasado por muchas etapas y ha sido manejado por diversas instituciones, las cuales nacen y desaparecen con el correr de los años según cambian las necesidades de quienes intervienen en ellas. Tuvo que pasar un siglo desde la creación de la primera bolsa en el país para que apareciera la Bolsa de Valores de Colombia, institución que hoy representa la unificación del Mercado Bursátil, un siglo de historia que se describe de forma detallada. Para el desarrollo del Mercado de Capitales y del Mercado Bursátil como parte de éste, es indispensable el apoyo de la academia, y la Universidad EAFIT ha sido un actor importante en dicho proceso

Deficiencias, limitaciones, ventajas y desventajas de las metodologías de análisis sísmico no lineal

El presente trabajo está dirigido a la comparación de las metodologías de análisis sísmico: dinámico cronológico no lineal, pushover tradicional, y dos procedimientos modales. La comparación se realizó a partir del estudio de un edificio de mediana altura, aporticado, de concreto reforzado, representativo de las edificaciones típicamente construidas en Bucaramanga. La estructura fue sometida a uno de los sismos definidos por el estudio de microzonificación de la ciudad, escalado a diferentes valores de aceleración pico efectiva. Los resultados obtenidos fueron comparados en términos de desplazamientos y derivas, con lo cual se pudieron detectar algunas deficiencias, limitaciones, ventajas y desventajas de las metodologías utilizadas, concluyendo que las metodologías modales son una buena aproximación para la determinación del comportamiento sísmico de estructuras de concreto reforzad

Desarrollo de chips de manzana anna (Malus domestica) mediante preconcentración osmótica y horneado industrial

The main objective of this thesis was the development of an Anna apple snack, which resembles a chip (crispy flake), by osmotic dehydration and industrial baking, avoiding the use of deep frying. For the development of the apple chips, a completely randomized design with factorial arrangement 32 was done (two factors, three levels within each factor, and 3 replications). The response variables analyzed were: moisture content, total sugars and acidity. The interpretation of the results was performed using the analysis ANOVA and the Tukey test. This was supplemented by a table of decision-making and it was found that the best treatment was osmotically dehydrated at 50 ° C within syrup (25% sucrose, 25% glucose and 50% water) and baked at 115 ° C for 15 minutes. The treatment was tested sensorially to estimate the liking and the crunchiness level measured as fracturability. In addition, the shelf life of the product was estimated by the kinetic degradation model. Likewise, the total antioxidant capacity of the product was measured by FRAP assay (Ferric reducing antioxidant power). The chemical profile and the nutritional content of the apple chips were determinated. In addition, three tentative programs for industrial assessment were proposed, namely quality control, HACCP and industrial processing plans. Finally, a market study was conducted using surveys, in which 99% of respondents would be willing to buy the product that tentatively would have the trade name “MANZANNA Chips”. The potential consumers of our product would be people between 18 and 65 years, living in Quito. However, we support that the market study embrace other cities and consumers.El objetivo de esta tesis fue el desarrollo de un snack de manzana Anna tipo chip (hojuela crocante), mediante deshidratación osmótica y horneado industrial sin incurrir en el uso de fritura. El producto fue desarrollado en base a un diseño experimental completamente al azar con arreglo factorial 32 de dos factores y tres niveles dentro de cada factor, con 3 repeticiones. Las variables de respuesta analizadas fueron: humedad, azúcares totales y acidez y la interpretación de los resultados fue realizada mediante el análisis de varianza ANOVA y la prueba Tukey de separación de medias. Esto fue complementado con una tabla de ponderación para la toma de decisiones. El mejor tratamiento fue el deshidratado osmóticamente a 50°C en un jarabe con 25% sacarosa, 25% glucosa y 50% agua y horneado a 115°C por 15 minutos. Este tratamiento fue evaluado sensorialmente y estimado su nivel de agrado y de crocancia medido como fracturabilidad. Además, se estimó el tiempo de vida útil en base al modelo de degradación cinética. La capacidad antioxidante total fue analizada a través del ensayo FRAP (poder antioxidante para reducir Fe3+). Simultáneamente al desarrollo del producto se determinó el perfil químico y el contenido nutricional de los chips. Adicionalmente se elaboraron los programas tentativos de control de calidad y el plan HACCP, así como el necesario para la elaboración industrial del producto. Finalmente, se elaboró un estudio de mercado mediante encuestas, donde se encontró que el 99% de los encuestados estaría dispuesto a comprar el producto que tentativamente tendría el nombre comercial de MANZANNA Chips. Inicialmente el producto tendría como potenciales consumidores a personas entre 18 y 65 años de la ciudad de Quito. Sin embargo se alienta que este estudio sea extendido a otras ciudades y grupos de edad

Time‐Dependent Spatial Amplitude Patterns of Harmonic Tremor at Arenal Volcano, Costa Rica: Seismic‐Wave Interferences?

International audienceSeismograms recorded at the receivers of a small-aperture seismic array usually display very similar waveforms and amplitudes, as a consequence of their close proximity. During the analysis of the volcanic tremor wave eld at Arenal volcano, Costa Rica, we detected signi cant di erences in the amplitudes of harmonic tremor recorded at the stations of a small-aperture (~210 m) seismic array. The amplitude distributions are geometrically complex and characterized by strong gradients. They occur just for harmonic tremors; any other type of seismic event produces nearly uniform amplitudes across the array. This suggests some relation with harmonic frequency content. Moreover, the spatial amplitude patterns change with time. Some of these observations could be explained by an extreme combination of source, path and site e ects. But they could be also produced by interference of di erent components of the seismic wave eld. We use numerical calculations to investigate the amplitude pattern generated by two interfering plane waves, and are able to reproduce the main features of the observed amplitude patterns. We propose mechanisms that might generate seismic wavefi elds with multiple components and conclude that interference can explain the complexity and variability of the harmonic tremor wave eld at Arenal volcano

Chinese consumers’ purchase intention of fresh cherries: Modeling of relations between satisfaction and perceived quality

The purpose of this study was to model Chinese consumers’ intention to purchase fresh cherries through direct and indirect relations and mediating role between perceived intrinsic quality, perceived extrinsic quality and satisfaction. The analytical method used was a structural equation modeling (SEM). Surveys were applied to 388 buyers in three traditional markets in Beijing, China. A confirmatory factor analysis was performed, which presented an adequate goodness of fit to accept the model, according to the literature, which confirmed the relations. The results showed, that perceived extrinsic quality and satisfaction are directly and significantly related to Chinese consumers’ intention to purchase fresh cherries. Additionally, an indirect and significant relationship was found between perceived intrinsic quality and purchase intention, through the mediating role of satisfaction. Highlights: Only the intrinsic perceived quality in fresh cherries is directly and significantly related to the satisfaction of Chinese consumers, generating indirect effects on the purchase intention through the mediating role of satisfaction, which is opposed to the results obtained in extrinsic perceived quality. The results obtained in this study determined that the intrinsic perceived quality does not present a direct and significant relationship with the purchase intention in fresh cherries, a result in conflict with that obtained in the extrinsic perceived quality. It was statistically demonstrated that intrinsic perceived quality has an indirect and significant influence on purchase intention through the mediating role of satisfaction; on the other hand, no indirect and significant influence was found between perceived extrinsic quality and purchase intention as a result of the mediating role of satisfaction. Satisfaction has a direct and significant relation on the purchase intention of Chinese consumers. The results of this research seem to be in line with the marketing initiatives developed by ASOEX, enhancing the attributes of intrinsic quality, color and size, and linking it to celebrations and traditions, through activities such as "Super Cherries days", "Chilean Cherries dance" and "Cherries from Chile", activities that have also been enhanced by public policies and agreements such as the free trade agreement between the two countries in force since 2005.The purpose of this study was to model Chinese consumers’ intention to purchase fresh cherries through direct and indirect relations and mediating role between perceived intrinsic quality, perceived extrinsic quality and satisfaction. The analytical method used was a structural equation modeling (SEM). Surveys were applied to 388 buyers in three traditional markets in Beijing, China. A confirmatory factor analysis was performed, which presented an adequate goodness of fit to accept the model, according to the literature, which confirmed the relations. The results showed, that perceived extrinsic quality and satisfaction are directly and significantly related to Chinese consumers’ intention to purchase fresh cherries. Additionally, an indirect and significant relationship was found between perceived intrinsic quality and purchase intention, through the mediating role of satisfaction. Highlights: Only the intrinsic perceived quality in fresh cherries is directly and significantly related to the satisfaction of Chinese consumers, generating indirect effects on the purchase intention through the mediating role of satisfaction, which is opposed to the results obtained in extrinsic perceived quality. The results obtained in this study determined that the intrinsic perceived quality does not present a direct and significant relationship with the purchase intention in fresh cherries, a result in conflict with that obtained in the extrinsic perceived quality. It was statistically demonstrated that intrinsic perceived quality has an indirect and significant influence on purchase intention through the mediating role of satisfaction; on the other hand, no indirect and significant influence was found between perceived extrinsic quality and purchase intention as a result of the mediating role of satisfaction. Satisfaction has a direct and significant relation on the purchase intention of Chinese consumers. The results of this research seem to be in line with the marketing initiatives developed by ASOEX, enhancing the attributes of intrinsic quality, color and size, and linking it to celebrations and traditions, through activities such as "Super Cherries days", "Chilean Cherries dance" and "Cherries from Chile", activities that have also been enhanced by public policies and agreements such as the free trade agreement between the two countries in force since 2005

Predation of Lepidophyma flavimaculatum (Squamata: Xantusiidae) by Basiliscus plumifrons (Squamata: Corytophanidae)

Lizards are the most diversified group of living reptiles with 7176 species worldwide (Uetz 2022). They play key roles in ecosystems where they are prey to a wide variety of predators, including snakes, other lizards, mammals, birds, and invertebrates (Pianka and Vitt 2006). The tropical forests of the new world contain a high variety of species of different sizes, shapes, and colors. In Costa Rica in particular, at least 80 species of lizards have been reported (Leenders 2019). They occupy highly diverse habitat types where they participate in food webs that involve many other species of vertebrates and invertebrates