On pairwise Lindelöf spaces

In this paper we define pairwise Lindelöf spaces and study their properties and their relations with other topological spaces. We also study certain  conditions by which a bitopological space will reduce to a single topology. Several examples are discussed and many well known theorems are generalized concerning Lindelöf spaces.En este artículo se definen espacios p-Lindelöf y se estudian sus propiedades y relaciones con otros tipos de espacios topológicos. También se estudian ciertas condiciones bajo las cuales un espacio biotipológico (con dos topologías) se reduce a uno con una sola topología. Se discuten varios ejemplos y se generalizan varios teoremas sobre espacios de Lindelöf

Significant Correlation of Species Longevity with DNA Double Strand Break-Recognition but not with Telomere Length

The identification of the cellular mechanisms responsible for the wide differences in species lifespan remains one of the major unsolved problems of the biology of aging. We measured the capacity of nuclear protein to recognize DNA double strand breaks (DSB) and telomere length of skin fibroblasts derived from mammalian species that exhibit wide differences in longevity. Our results indicate DNA DSB recognition increases exponentially with longevity. Further, an analysis of the level of Ku80 protein in human, cow, and mouse suggests that Ku levels vary dramatically between species and these levels are strongly correlated with longevity. In contrast mean telomere length appears to decrease with increasing longevity of the species, although not significantly. These findings suggest that an enhanced ability to bind to DNA-ends may be important for longevity. A number of possible roles for increased levels of Ku and DNA-PKcs are discussed