Using samples drawn from the Sloan Digital Sky Survey, we study the relationship between local galaxy density and the properties of galaxies on the red sequence. After removing the mean dependence of average overdensity (or “environment”) on color and luminosity, we find that there remains a strong residual trend between luminosity–weighted mean stellar age and environment, such that galaxies w...

The term malnutrition generally refers both to under nutrition and over nutrition Many factors can cause malnutrition, most of which relate to poor diet or severe and repeated infections, particularly in underprivileged populations. Inadequate dietand disease, in turn, are closely linked to the general standard of living, the environmental conditions, and whether a population is able to meet it...

Introduction The artificial geochemical land where all organisms lived and will live under the conditions of increased level of radiation was set up due to the Chernobyl disaster in 1986. An urgent necessity for studying the various biological effects of chronic influence of low intensity radiation on both individual organisms and populations arose. Combined cytogenetic and radioecological inve...

Networks have become a popular way to concisely represent complex nonlinear systems where the interactions and parameters are imprecisely known. One challenge is how best to describe the associated dynamics, which can exhibit complicated behavior sensitive to small changes in parameters. A recently developed computational approach that we refer to as a database for dynamics provides a robust an...

the systematics, morphology, distribution, biology, economic importance and conservation of the freshwater eel ( anguilla anguilla ) of iran are described, the species is illustrated, and a bibliography on this fish in iran is provided. the species is found in the caspian sea basin as an exotic.

Ernst Mayr’s typological/population distinction is a conceptual thread that runs throughout much of his work in systematics, evolutionary biology, and the history and philosophy of biology. Mayr himself claims that typological thinking originated in the philosophy of Plato and that population thinking was first introduced by Charles Darwin and field naturalists. A more proximate origin of the t...