Modeling Weak Gravitational Lensing Through C++

Gravitational Lensing has become an integral part of astrophysics and the study of matter in the universe. In weak gravitational lensing, an object appears distorted when viewed from the observer’s perspective. This is caused by the bundle of light being distorted by an object of considerable mass. Because the distance to each part of this bundle is not the same, the rays of light are affected differently causing a shearing and magnification of the image. This alteration in the image we see can be modeled using the thin lens approximation. By integrating the equations for light travel based on general relativity, a more accurate model can be created. Over the summer of 2008, my mentor and I have worked on creating a program through this method. By coding numerous mathematical operations and rewriting existing code to support a new coordinate system we have created a full program

The role of snow cover in the Northern Hemisphere winter to summer transition

This paper examines the role of North Hemisphere snow cover in the linkage between the winter North Atlantic Oscillation (NAO) and the summer Northern Annular Mode (NAM). This transition is partially supported by the persistence of the NAO-induced snow cover anomalies and the asymmetric thermal distribution induced by summer snow cover. We define an index of subpolar temperature difference which links winter NAO with the subsequent summer NAM. The index is also significant in the linkage between summer and winter climates and can be used as an useful predictor of the upcoming winter NAO

Los medios de comunicación en la Cuba post Castro

Este ARI estudia los posibles escenarios para los medios de comunicación en Cuba en la era post Fidel Castro. En el contexto de la sucesión de poder que tiene lugar actualmente en Cuba, pueden dibujarse algunos escenarios para los medios de comunicación de la isla en una era post Fidel. La historia de los medios de comunicación en Cuba durante el período revolucionario, las experiencias de la URSS y los restantes países socialistas de Europa del Este, luego de la caída del Muro de Berlín, y las particulares circunstancias de China son algunos de los elementos a tener en cuenta

Propiedades psicométricas del Cuestionario de Violencia de Pareja, versión corta (DVQ-8): una herramienta de evaluación para entornos educativos

Este artículo proporciona información psicométrica de un instrumento de screening de victimización en parejas jóvenes: Dating Violence Questionnaire de 8 ítems. Un primer estudio desarrolló un análisis factorial exploratorio con matrices de correlación policóricas y rotación oblimin con 990 jóvenes universitarios mexicanos con edad promedio de 19.5, de las que dos tercios fueron mujeres, obteniendo una estructura unifactorial con alta confiabilidad para varones y mujeres. El segundo estudio, con una muestra de 355 participantes, proporcionó información sobre la validez del instrumento, encontrando una relación positiva entre el Dating Violence Questionnaire de 8 ítems y victimización percibida, se obtuvieron una significación alta y el tamaño del efecto grande y una relación negativa entre el instrumento y estado de salud, con un efecto moderado. En conclusión, el DVQ-8 incluye indicadores confiables y válidos para la detección temprana de victimización en contextos educativos.This article provides psychometric information from a screening tool for victimization in young couples: the 8-Item Dating Violence Questionnaire. The first study undertook an exploratory factor analysis with polymorphic correlation matrices and oblimin rotation of 990 Mexican university students with an average age of 19.5, two thirds of whom were women, obtaining a unifactorial structure with high reliability for males and females. The second study, with a sample of 355 participants, provided information on the validity of the instrument, finding a positive relationship between the 8-Item Dating Violence Questionnaire and perceived victimization. High significance and a large effect size and negative relationship were obtained between the instrument and state of health, with a moderate effect. In conclusion, the DVQ-8 includes reliable, valid indicators for the early detection of victimization in educational settings