introduction: there are several methods for evaluating microleakage in dentistry, for example dye or bacterial leakage, electro-chemical methods, radioisotope labeling and fluid filtration. the purpose of this study was to assemble the fluid filtration system for quantitative evaluation of microleakage in dental materials. materials and methods: the roots were connected to a tube filled with an...

Ecological theory predicts that competition for a limiting resource will lead to the exclusion of species unless the within-species effects outweigh the between-species effects. Understanding how multiple competitors might coexist on a single resource has focused on the prescriptive formalism of a necessary niche width and limiting similarity. Here, we show how continuously varying life histori...