Empirical evidence of jump behavior in the Colombian bond market

Simulations and empirical studies suggest that incorporating a discontinuous jump process in asset pricing models improve volatility forecasting, pricing of instruments, and hedging positions in a portfolio. In this paper we analyze high frequency market data of Colombian sovereign bonds to study the presence or absence of discontinuities in the price generating process. We find that Colombian sovereign debt experiments jumps across all maturities but with different frequencies, in particular, we do not find that long term bonds jump less frequently than short term bonds. Furthermore, bonds with closer maturities cojump in greater magnitude than those with a greater distance between them. Finally, we find significant day-of-the week effects, as well as an important increase in the jump frequency due to surprises in economic information related to US monetary policy, and no effect due to direct monetary policy announcements in Colombia.La incorporación de procesos con saltos en la modelación de precios se ha demostrado que mejora el pronóstico de volatilidad, la valoración de activos y las coberturas de un portafolio. El estudio encuentra que en el mercado local de bonos soberanos de Colombia se observan saltos en la formación de precios a lo largo de toda la curva, con diferentes intensidades. Contrario a lo esperado, no se identifica una frecuencia de saltos menor en los bonos de largo plazo en comparación con los bonos de corto plazo. Además, se encuentra que los bonos con periodos de maduración similares tienen una mayor frecuencia de saltos en comparación con aquellos que tienen periodos al vencimiento más distantes. Esto indica una relación entre la proximidad en los periodos de maduración y la ocurrencia de saltos en los precios de los bonos soberanos. En cuanto a las estacionalidades, se encuentran patrones semanales persistentes en la frecuencia de los saltos. Asimismo, se observan aumentos significativos en la frecuencia de los saltos asociados a sorpresas en la información económica que afecta la política monetaria de Estados Unidos. Sin embargo, no se encuentran efectos similares asociados a anuncios específicos de política monetaria interna

Cytosolic ascorbate peroxidase and Cu, Zn-superoxide dismutase improve seed germination, plant growth, nutrient uptake and drought tolerance in tobacco

The effects of over-expression of two cytosolic antioxidant enzymes (Cu, Zn-SOD and/or APX) on plant nutrition, gas exchange, chlorophyll fluorescence, seed viability and germination in transgenic tobacco (Nicotiana tabacum cv. Xanthi) under deficit irrigation or salinity conditions were investigated. Three transgenic lines of tobacco were used in this study: line 17, harboring 2 copies of the cytosolic CuZn-SOD (cytsod) gene; line 51, with 2 copies of the cytosolic APX (cytapx) gene and line 39, harboring one copy of each gene. Over-expression of cytosolic antioxidants enzymes in tobacco plants resulted in a better growth performance that correlated with an improved photosynthetic capacity and nutrient uptake. Moreover, cytsod or cytapx genes promoted seed germination, and enhanced tolerance to mild water stress. In addition, this enhanced antioxidant capacity protected seeds from ageing during prolonged storage, and stimulated germination under salt stress conditions. These results suggest that cytosolic antioxidant transgenes are useful tools to improve drought tolerance, nutrient uptake and seed germination under stressful conditions.PDV acknowledges the CSIC and the Spanish Ministry of Economy and Competitiveness for his ‘Ramon y Cajal’ research contract, co-financed by FEDER funds. This work was supported by the Spanish Ministry of Economy and Competitiveness (Project CICYT BFU2009-07443) co-financed by FEDER funds, and the Spanish Ministry of Economy and Competitiveness (Project INIA, RTA2013-00026-C03-00).Peer reviewe

Software to Assist Visually Impaired People During the Craps Game Using Machine Learning on Python Platform

Pattern recognition is a prominent area of research in computer vision, where different methods have been proposed in the last 50 years. This work presents the development of a Python API to identify the result of two six-sided dice used in the game called “Craps” as a no-controlled environment to help visually impaired people. The software is structured in four stages. The first one is capturing images through a device with a digital camera connected to the web via IP address. The second stage corresponds to the captured image processing; it is necessary to establish a standard image size and resize and equalize the digitized image. The third stage seeks to segment the object of study by artificial vision techniques to identify the result of the dice after being thrown. Finally, the fourth stage is to interpret the result and play it through a speaker. The expected possible result is a system that integrates the four stages mentioned above through an intuitive and accessible low-cost Python API, mainly aimed at visually impaired people

Creación y puesta en marcha de una empresa comercializadora de fruta fresca empacada con atmósfera modificada (fomento al espíritu empresarial)

"El mercado de los pasa bocas o snacks ha sido un negocio creciente en Colombia (suman ingresos por $1.9 billones al año (Redacción de El País, 2014)). debido a que actualmente la mayoría de personas han mostrado una tendencia hacia el consumo de alimentos en pequeñas proporciones entre las diferentes comidas del día. El problema del consumo frecuente de este tipo de alimentos, radica en el hecho de que dichos productos no son saludables, ya que la mayoría está compuesta de harinas, fritos, lácteos y elementos con grandes cantidades de colesterol. Por esta razón, se planteó la idea de desarrollar una empresa especializada en la comercialización de frutas frescas empacadas con atmósfera modificada. Esta técnica permite que las frutas conserven su frescura y estén listas para el consumo humano y así mismo su fácil adquisición por medio de máquinas dispensadoras las cuales permitirán el consumo en diferentes horas del día. de forma confiable y rápida. Es allí donde el presente proyecto cobra sentido al suplir la necesidad de los consumidores en busca de productos saludables, a través de la innovación en su conservación y canal de distribución. El impacto más importante que se quiere generar cubre dos caras en el mercado Colombiano, por un lado se quiere potenciar el consumo de frutas beneficiando a miles de productores colombianos, ""que muchas veces no tienen en dónde vender sus cosechas, porque en el país no se consume la cantidad suficiente de frutas"" (Portafolio 2015), y por otro lado se quiere generar en los trabajadores el hábito de consumir frutas logrando que el sistema inmunológico se desarrolle de manera saludable, ya que todas las vitaminas y los componentes para estar sano se encuentran en las frutas, dando lugar a una medicina preventiva a enfermedades relacionadas con el sedentarismo y los malos hábitos alimenticios."Ingeniero (a) IndustrialPregrad

Intelligent system to detect violations in pedestrian areas committed by vehicles in the city of Cartagena de Indias

his article presents applied research which proposes an approach to a low-cost electronic system that allows the detection of violations in pedestrian areas. For this purpose, we proposed an electronic system that implements artificial intelligence algorithms and Internet of Things architectures to detect in realtime these events. The proposal focuses on experimental laboratory work through which we developed and validated a system by analyzing a real pedestrian zone scenario and invasion of the pedestrian zone. As a result of this work, we deliver a labeled dataset to the scientific community that can serve as input to new projects and the development of better offender detection algorithms.Universidad Tecnológica de Bolíva

Design of a Segmentation and Classification System for Seed Detection Based on Pixel Intensity Thresholds and Convolutional Neural Networks

Due to the computational power and memory of modern computers, computer vision techniques and neural networks can be used to develop a visual inspection system of agricultural products to satisfy product quality requirements. This chapter employs artificial vision techniques to classify seeds in RGB images. As a first step, an algorithm based on pixel intensity threshold is developed to detect and classify a set of different seed types, such as rice, beans, and lentils. Then, the information inferred by this algorithm is exploited to develop a neural network model, which successfully achieves learning classification and detection tasks through a semantic-segmentation scheme. The applicability and satisfactory performance of the proposed algorithms are illustrated by testing with real images, achieving an average accuracy of 92% in the selected set of classes. The experimental results verify that both algorithms can directly detect and classify the proposed set of seeds in input RGB images. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG

Plexopatía braquial secundaria a tumor maligno de la vaina del nervio periférico

  Brachial plexopathy secondary a malignant tumor of the peripheral nerve sheath.Introduction. Malignant peripheral nerve sheath tumor (MPNST) are sarcomas that are rarely located in the upper limb. Clinical case. We present a 31- year-old woman with progressive dysesthesia and weakness of the left upper limb. The neurophysiological study showed damage in the left brachial plexus. A soft tissue mass that was invading the plexus was observed in the magnetic resonance image. The anatomopathological study was compatible with MPNST diagnosis. Conclusions. Intrinsic tumors of the brachial plexus are uncommon. A MPNST is an extremely aggressive mesenchymal tumor that is seldom rooted in the brachial plexus. Key words: Brachial plexus. Brachial plexopathy. Neoplasm. Malignant tumor. Peripheral nerve sheath.  Introducción: el plexo braquial puede verse afectado por patología neoplásica tanto primaria como secundaria. Los tumores primarios del plexo braquial son entidades poco frecuentes, aunque algunos, como el tumor maligno de la vaina del nervio periférico pueden tener un comportamiento agresivo. Caso clínico: se presenta una mujer de 31 años con disestesias y debilidad progresiva en el miembro superior izquierdo. El estudio neurofisiológico mostró afectación del plexo braquial izquierdo. En la resonancia magnética se observó una masa de tejido blando que invadía el plexo braquial. El estudio histológico fue compatible con un tumor maligno de la vaina del nervio periférico. Conclusiones: el tumor maligno de la vaina del nervio periférico es un tumor altamente agresivo que puede aparecer en pacientes sin datos clínicos de neurofibromatosis tipo 1. Debe mantenerse un elevado nivel de sospecha con el objetivo de no retrasar el diagnóstico para así poder realizar un tratamiento lo más conservador posible. Palabras clave: Plexo braquial. Plexopatía braquial. Neoplasia. Tumor maligna. Vaína del nervio periférico. &nbsp

A reliable and valid tool to assess the sexual acceptability of contraceptive methods

Introduction: Adequate identification of the sexual acceptability of contraceptive methods is key for designing health promotion interventions, assessing their impacts, and increasing their effectiveness. This study aimed to develop and validate a questionnaire to explore the preferences of women depending on their epidemiological characteristics and their partner relationships—the Sexual Acceptability of Contraceptive Methods Questionnaire [in Spanish, Aceptabilidad Sexual de los Métodos Anticonceptivos (ASMA)]. Methods: Psychometric validation was conducted using Exploratory Factorial Analysis (EFA) and confirmatory factor analysis (CFA). The reliability of the final version of the questionnaire was explored using Cronbach’s alpha and McDonald omega to estimate internal consistency. Results: A three-factor model was identified. Factor 1 (explaining 28.32% of the model) corresponds to questions concerning the use and placement of the contraceptive and includes 6 items; Factor 2 (explaining 24.23%) corresponds to other factors that affect the relationship such as bleeding and side effects of the contraceptive method and includes 10 items; and Factor 3 (explaining 18.94%) corresponds to the couple relationship and includes 8 items. Conclusion and implications: The ASMA questionnaire provides a valid and reliable tool for assessing the sexual acceptability of various contraceptive methods. This instrument gathers data that provide information on various aspects of women’s sexuality, health, education, and beliefs, all of which can determine the preference for one contraceptive method over another. Moreover, the tool can help to identify profiles of women who have different preferences when selecting a particular method

Next‐generation sequencing reveals that miR‐16‐5p, miR‐19a‐3p, miR‐451a, and miR‐25‐3p cargo in plasma extracellular vesicles differentiates sedentary young males from athletes

A sedentary lifestyle and Olympic participation are contrary risk factors for global mortality and incidence of cancer and cardiovascular disease. Extracellular vesicle miRNAs have been described to respond to exercise. No molecular characterization of young male sedentary people versus athletes is available; so, our aim was to identify the extracellular vesicle miRNA profile of chronically trained young endurance and resistance male athletes compared to their sedentary counterparts. A descriptive case–control design was used with 16 sedentary young men, 16 Olympic male endurance athletes, and 16 Olympic male resistance athletes. Next‐generation sequencing and RT‐qPCR and external and internal validation were performed in order to analyze extracellular vesicle miRNA profiles. Endurance and resistance athletes had significant lower levels of miR‐16‐5p, miR‐19a‐3p, and miR‐451a compared to sedentary people. Taking all together, exercise‐trained miRNA profile in extracellular vesicles provides a differential signature of athletes irrespective of the type of exercise compared to sedentary people. Besides, miR‐25‐3p levels were specifically lower in endurance athletes which defines its role as a specific responder in this type of athletes. In silico analysis of this profile suggests a role in adaptive energy metabolism in this context that needs to be experimentally validated. Therefore, this study provides for the first time basal levels of circulating miRNA in extracellular vesicles emerge as relevant players in intertissue communication in response to chronic exercise exposure in young elite male athletes