En este trabajo realizamos un estudio de la estabilidad dinámica de planetas hipotéticos en torno de los puntos Lagrangianos L4 de planetas conocidos en los sistemas planetarios extrasolares Kepler-9 y Kepler-56. Utilizando integradores simplécticos de segundo orden y considerando a los planetas Troyanos como partículas de prueba, estudiamos un vasto conjunto de condiciones iniciales para los Troyanos en el espacio de parámetros orbitales semieje mayor versus excentricidad, a fin de extraer conclusiones de carácter estadístico sobre su posible existencia. El análisis de los datos de las integraciones es realizado determinando los tiempos de sobrevivencia de las partículas, sus excentricidades máximas alcanzadas y los desvíos registrados en sus semiejes mayores y excentricidades, lo que permite identificar las regiones de movimiento estable. Nuestro estudio muestra que la exist...

Peru is a megadiverse country and ranks third in amphibian diversity. Nevertheless, 21% of its amphibian species are threatened. Telmatobius is one of the most endangered genera of this class of vertebrates, with the main threats being habitat loss and degradation, illegal trafficking, climate change, and infectious diseases. This study aimed to determine the presence of hemoparasites in seized specimens. Blood samples were collected from the ventral abdominal vein of 50 confiscated Telmatobius frogs in Lima, and blood smears were prepared and stained using Wright’s stain. Hemogregarines of the Dactylosoma genus (Dactylosomatidae family) were identified in 14% (n = 7/50) of the samples analyzed. This study represents the first report of a hemoparasite in Telmatobius.

En el Perú se han descrito 17 especies diferentes de tortugas de las cuales 15 son de vida marina o continental (en ríos o lagos) y apenas 2 especies desarrollan su vida íntegramente fuera del agua, éstas son la tortuga de patas rojas (Geochelone carbonaria) y la tortuga motelo (Geochelone denticulata). Recientemente se ha dado importancia a la realización de estudios de campo que permitan recolectar información sobre el estado de salud de poblaciones silvestres con énfasis en aquellas especies en peligro de extinción. La evaluación hematológica es el método más recomendado a través del cual se puede obtener excelentes indicadores del estado de salud de un individuo (Owens y Ruiz, 1980; Lowell, 1998). El campo de la hematología en reptiles es hasta cierto punto, nuevo y poco conocido. Sin embargo ha ido evolucionando, logrando así habilidad y experiencia, con más y nuevas...

In this paper is evaluation of susceptibility to hydrogen degradation ofAl SI steel 1045. Susceptibility of AISI 1045 steel to hydrogen embrittlement has been made by mechanical tensile test a static fatigue in hydrogen generation environments. Test were carred out using round notched specimens subjected to axial tensile load in O, IN EI2SO4 solution with to 0,25 g/1 arsenite sodium using hydrogen cathodic charging technique at densities current various. Reduction in area, tensile strength and fracture delayed of time were chosen relative changes as measures of susceptibility to hydrogen embrittlement. Fracture modes of failed samples were examined with of microscope. Mechanical test in inert environmental (air) comparisons and mechanical test in hydrogen generating environment show that both steels are susceptibility to hydrogen embrittlement.Samples of esferoidized steel have lower los...

In this paper is evaluation of susceptibility to hydrogen degradation ofAl SI steel 1045. Susceptibility of AISI 1045 steel to hydrogen embrittlement has been made by mechanical tensile test a static fatigue in hydrogen generation environments. Test were carred out using round notched specimens subjected to axial tensile load in O, IN EI2SO4 solution with to 0,25 g/1 arsenite sodium using hydrogen cathodic charging technique at densities current various. Reduction in area, tensile strength and fracture delayed of time were chosen relative changes as measures of susceptibility to hydrogen embrittlement. Fracture modes of failed samples were examined with of microscope. Mechanical test in inert environmental (air) comparisons and mechanical test in hydrogen generating environment show that both steels are susceptibility to hydrogen embrittlement.Samples of esferoidized steel have lower los...