Simulación financiera aplicada a la valoración del riesgo de crédito con el modelo de opciones

This paper presents financial simulation as the best alternative for valuating credit risk with the Merton Model on a real option. We propose this in contrast to the Black and Scholes model introduced by Hull, Nelken and White in 2004 for the same case study. To demonstrate this, we begin by reviewing the basic concepts of a financial option. Then we present the Black-Scholes model for the valuation of European options with special emphasis on the assumptions and the limitations that this possibility implies. We introduce the analogy between real options and financial options that allows the measurement of credit risk on investment opportunities. We explain the Merton model, and finally, we propose financial simulation as a general and powerful methodology to quantify credit risk in the Merton model, including an application on an investment project with “Crystal Ball”.El presente documento muestra cómo la simulación financiera puede ser una buena alternativa para valorar el riesgo de contraparte de una opción real con el Modelo de Merton, en contraposición del modelo de Black-Scholes introducido por Hull, Nelken y White en el año 2004 para el mismo caso de estudio. Para tal fin, se revisan los conceptos básicos de opción financiera, se presenta el modelo de Black-Scholes para la valoración de opciones europeas sobre acciones haciendo especial énfasis en los supuestos y las limitaciones que implica éste par ael caso colombiano; se introduce la analogía entre opciones reales y opciones financieras, que permite medir el riesgo de crédito en las oportunidades de inversión; se explica el modelo de Merton y, por último, se propone la simulación financiera como una metodología más general y potente para cuantificar el riesgo crediticio con el modelo de opciones, haciendo a su vez una aplicación sobre un proyecto de Inversión en “Crystal Ball”

Simulación financiera aplicada a la valoración del riesgo de crédito con el modelo de opciones

This paper presents financial simulation as the best alternative for valuating credit risk with the Merton Model on a real option. We propose this in contrast to the Black and Scholes model introduced by Hull, Nelken and White in 2004 for the same case study.To demonstrate this, we begin by reviewing the basic concepts of a financial option. Then we present the Black-Scholes model for the valuation of European options with special emphasis on the assumptions and the limitations that this possibility implies. We introduce the analogy between real options and financial options that allows the measurement of credit risk on investment opportunities. We explain the Merton model, and finally, we propose financial simulation as a general and powerful methodology to quantify credit risk in the Merton model, including an application on an investment project with “Crystal Ball”.El presente documento muestra cómo la simulación financiera puede ser una buenaalternativa para valorar el riesgo de contraparte de una opción real con el Modelode Merton, en contraposición del modelo de Black-Scholes introducido por Hull,Nelken y White en el año 2004 para el mismo caso de estudio.Para tal fin, se revisan los conceptos básicos de opción financiera, se presenta elmodelo de Black-Scholes para la valoración de opciones europeas sobre accioneshaciendo especial énfasis en los supuestos y las limitaciones que implica éste parael caso colombiano; se introduce la analogía entre opciones reales y opcionesfinancieras, que permite medir el riesgo de crédito en las oportunidades deinversión; se explica el modelo de Merton y, por último, se propone la simulaciónfinanciera como una metodología más general y potente para cuantificar el riesgocrediticio con el modelo de opciones, haciendo a su vez una aplicación sobre unproyecto de Inversión en “Crystal Ball”

The Respiratory Exchange Ratio is Associated with Fitness Indicators Both in Trained and Untrained Men: A Possible Application for People with Reduced Exercise Tolerance

Background The respiratory exchange ratio (RER) indirectly shows the muscle's oxidative capacity to get energy. Sedentarism, exercise and physically active lifestyles modify it. For that reason, this study evaluates the associations between RER during sub-maximum exercise and other well established fitness indicators (body fat, maximum heart rate, maximum O 2 uptake, workload, and lactate threshold), in physically active trained and untrained men. Methods The RER, O 2 uptake and blood lactate were measured in eight endurance trained and eight untrained men (age, 22.9 ± 4.5 vs. 21.9 ± 2.8 years; body mass, 67.1 ± 5.4 vs. 72.2 ± 7.7 kg; body fat, 10.6 ± 2.4% vs. 16.6 ± 3.8% and maximum O2 uptake, 68.9 ± 6.3 vs. 51.6 ± 5.8 ml · kg −1 · min −1 ), during maximum exercise test and during three different sub-maximum exercises at fixed workload: below, within or above the lactate threshold. Results Endurance trained men presented higher O 2 uptake, lower blood lactate concentrations and lower RER values than those in untrained men at the three similar relative workloads. Even though with these differences in RER, a strong association (p < 0.05) of RER during sub-maximum exercise with the other well established fitness indicators was observed, and both maximum O 2 uptake and lactate threshold determined more than 57% of its variance (p < 0.05). Conclusions These data demonstrate that RER measurement under sub-maximum exercise conditions was well correlated with other established physical fitness indicators, despite training condition. Furthermore, the results suggest that RER could help obtain an easy approach of fitness status under low exercise intensity and could be utilized in subjects with reduced exercise tolerance

Inference of proto-neutron star properties in core-collapse supernovae from a gravitational-wave detector network

The next Galactic core-collapse supernova (CCSN) will be a unique opportunity to study within a fully multi-messenger approach the explosion mechanism responsible for the formation of neutron stars and stellar-mass black holes. State-of-the-art numerical simulations of those events reveal the complexity of the gravitational-wave emission which is highly stochastic. This challenges the possibility to infer the properties of the compact remnant and of its progenitor using the information encoded in the waveforms. In this paper we take further steps in a program we recently initiated to overcome those difficulties. In particular we show how oscillation modes of the proto-neutron star, highly visible in the gravitational-wave signal, can be used to reconstruct the time evolution of their physical properties. Extending our previous work where only the information from a single detector was used we here describe a new data-analysis pipeline that coherently combines gravitational-wave detectors' data and infers the time evolution of a combination of the mass and radius of the compact remnant. The performance of the method is estimated employing waveforms from 2D and 3D CCSN simulations covering a progenitor mass range between 11$\mathrm{M_{\odot}}$\, and 40$\mathrm{M_{\odot}}$\, and different equations of state for both a network of up to five second-generation detectors and the proposed third-generation detectors Einstein Telescope and Cosmic Explorer. Our study shows that it will be possible to infer PNS properties for CCSN events occurring in the vicinity of the Milky Way, up to the Large Magellanic Cloud, with the current generation of gravitational-wave detectors

The A54T polymorphism in the FABP2 gene and its relationship with obesity

Introduction: Obesity is a complex, multifactorial, and mostly preventable disease affecting, along with overweight, more than a third of today’s world population. Variations in the nucleotide sequence of both metabolic and appetite control genes have been counted among these non-modifiable factors and are associated with BMI, lipidic profile, and abdominal circumference alterations. Methods: An analytical, non-experimental, and transversal research was done with the purpose to assess the presence of A54T polymorphism in the FABP gene in a sub-sample from the Maracaibo City Metabolic Syndrome Prevalence Study. Results: 154 individuals eight subjects were carriers of the A54Tpolymorphism, namely, a genotypic frequency of 5.19 %, with a sex distribution of 50 % for women (n=4) and 50 % (n=4) for men. In respect of alleles similarity degree, 75 % (n=6) were homozygous, and 25 % (n=2) were heterozygous. Obesity diagnosis throughout BMI was only present in 12.50 % (n=1) of the A54T carriers. Conversely, 25 % (n=2) of the carriers were overweighed; 50 % (n=4) were presented as normal-weight people; and only 12.50 % (n=1), in one underweighted person. Conclusion: As in many other studies, we do not find an association between Ala54Thr polymorphism and obesity. This result reinforces the fact of the multifactorial character of these diseases and a carrier state of this polymorphism is not necessarily to experience a higher obesity risk, at least, in our environment.La obesidad es una enfermedad compleja, multifactorial y en su mayor parte prevenible que afecta, a más de un tercio de la población mundial actual. Las variaciones en la secuencia de nucleótidos de los genes de control del metabolismo y del apetito se consideran hasta ahora como factores no modificables y se asocian con alteraciones del IMC, del perfil lipídico y de la circunferencia abdominal. Métodos: Se realizó una investigación analítica, no experimental y transversal con el propósito de evaluar la presencia del polimorfismo A54T en el gen FABP en una submuestra del Estudio de Prevalencia del Síndrome Metabólico de la Ciudad de Maracaibo. Resultados: De los 154 individuos de la submuestra ocho sujetos fueron portadores del polimorfismo A54T, es decir, una frecuencia genotípica de 5,19 %, con una distribución por sexo de 50 % para las mujeres (n=4) y 50 % (n=4) para los hombres. Con respecto al grado de similitud de los alelos, el 75 % (n=6) eran homocigotos y el 25 % (n=2) heterocigotos. El diagnóstico de obesidad a lo largo del IMC sólo estuvo presente en el 12,50 % (n=1) de los portadores de A54T. Por el contrario, el 25 % (n=2) de los portadores tenían sobrepeso; el 50 % (n=4) se presentaron como personas de peso normal; y sólo el 12,50 % (n=1) en la categoría de peso insuficiente. Conclusión: No se encontró una asociación entre el polimorfismo de Ala54Thr y la obesidad. Este resultado refuerza el carácter multifactorial de estas enfermedades y que un estado portador de este polimorfismo no es causa necesaria para padecer obesidad, al menos, en nuestro medio

Factorial structure and reliability of the academic satisfaction questionnaire on Chilean medical students

Indexación: Web of Science; Scopus.El presente estudio analiza la estructura factorial y confiabilidad del cuestionario de satisfacción académica (CSA) en una muestra de 563 estudiantes de medicina, entre 19 y 29 años (media de 20,42); provenientes de cuatro universidades chilenas. Una vez finalizada la traducción al castellano se exploró la validez de contenido de los ítems mediante un juicio de expertos. La estructura factorial del cuestionario se analizó a través de un análisis factorial exploratorio empleando el método Análisis de Ejes Principales (AEP). Los resultados preliminares de la fiabilidad y validez del instrumento han mostrado que la estructura de un factor es viable y adecuada de acuerdo a los requisitos psicométricos establecidos, aunque se recomiendan futuros estudios que evalúen su validez y confiabilidad en otros programas de pregrado.The present study examines the factorial structure and reliability of the academic satisfaction questionnaire (CSA) in a sample of 563 medical students, between 19 and 29 years (average of 20.42); from four Chilean universities. Once translated into Spanish explored the validity of the items content was evaluated through experts opinions. The factorial structure of the scale was analyzed through an exploratory factor analysis using the Principal Axis Analysis method (AEP).The preliminary results of the reliability and validity of the instrument have shown that a factor structure is viable and appropriate according to the established psychometric requirements, although future studies to evaluate its validity and reliability in other undergraduate programs are recommended.http://www.redalyc.org/articulo.oa?id=45964543200

Larval stages of crustacean species of interest for conservation and fishing exploitation in the western Mediterranean

Decapod crustaceans are the main target species of deep water bottom trawl fisheries in the western Mediterranean. Despite their importance for fisheries and conservation, little is known about their larval development, especially in the case of deep water species. In this paper we present new information on the occurrence and morphology of larval stages for some species of commercial interest based on samples collected off the Balearic Islands. Mesozooplankton sampling was carried out using depth-stratified sampling devices at two stations located on the continental shelf break and middle slope, in the northwest and south of Mallorca in late autumn 2009 and summer 2010. We describe in detail the second mysis stage of the red shrimp Aristeus antennatus, not previously known, and the first larval stage of the slipper lobster Scyllarides latus, poorly described almost a hundred years ago. We also report the second finding of larvae of the spider crab Maja squinado and the first capture from the field of larval stages of the rose shrimp Parapenaeus longirostris and slipper lobster in the MediterraneanPublicado

A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo

This paper presents the gravitational-wave measurement of the Hubble constant (H0) using the detections from the first and second observing runs of the Advanced LIGO and Virgo detector network. The presence of the transient electromagnetic counterpart of the binary neutron star GW170817 led to the first standard-siren measurement of H0. Here we additionally use binary black hole detections in conjunction with galaxy catalogs and report a joint measurement. Our updated measurement is H0 = 69+16−8 km s-1 Mpc-1 (68.3% of the highest density posterior interval with a flat-in-log prior) which is an improvement by a factor of 1.04 (about 4%) over the GW170817-only value of 69+17−8 km s-1 Mpc-1. A significant additional contribution currently comes from GW170814, a loud and well-localized detection from a part of the sky thoroughly covered by the Dark Energy Survey. With numerous detections anticipated over the upcoming years, an exhaustive understanding of other systematic effects are also going to become increasingly important. These results establish the path to cosmology using gravitational-wave observations with and without transient electromagnetic counterparts