In the marine environment, mercury is accompanied by selenium in all investigated species of mammals, birds, and fish--possibly due to a normal homeostatic regulation. It therefore seems likely that selenium will exert its protective action against mercury toxicity in the marine environment, decreasing its detrimental effects on reproduction, behavior, growth, etc. of the organisms and thus pro...

The coastal plain of the Rio Grande do Sul state (RS) in southern Brazil, has an enormous lagoon complex in its southern portion formed by Patos Lagoon, Mirim Lagoon, Mangueira Lagoon and several other smaller lakes. This system was originated from successive transgression and regression cycles, which took place since the upper Pleistocene (Vilwoock, 1984). Patos Lagoon is a huge chocked lagoon...

We now know that from a functional standpoint, jointly determined ecological–economic systems (ecosystems) cycle over time. However, because this recognition has been recent, the ecological economics literature contains very few formal studies of the management of cyclical ecosystems. Consequently, the objective of this paper is to use renewal theory to examine two ways of analyzing the optimal...

Invasive molluscs in Umbrian inland waters: ecological and reproductive aspects The increasing colonisation by aquatic invasive molluscs has only recently received scientific attention in Umbria, notwithstanding the possible great impact on the functionality and biodiversity of the freshwater ecosystems. The present contribution highlights the results of investigations carried out on Dreissena ...

The first flowering plant fossils occur as rare, undiverse pollen grains in the Early Cretaceous (Valanginian-Hauterivian). Angiosperms diversified slowly during the Barremian-Aptian but rapidly during the Albian-Cenomanian. By the end of the Cretaceous, at least half of the living angiosperm orders were present, and angiosperms were greater than 70% of terrestrial plant species globally. The r...

Electronic paper (e-paper), an electronic replacement for white paper that attempts to copy its properties as closely as possible, is available since about three decades. Research efforts in this area have created several different technological approaches to the issue, one of its most promising being electrophoretic displays (EPDs). Due to their extraordinary properties, they have the potentia...

Kassahun Embaye. 2003. Ecological aspects and resource management of bamboo forests in Ethiopia. Doctoral dissertation. This thesis describes the extent and condition of the natural bamboo forests of Ethiopia and their actual and potential values for society and environment. It assesses in detail the growth and nutrient dynamics in a selected highland bamboo forest in Southwest Ethiopia (Masha)...