For two communities, species overlap has been defined by Smith, Solow, and Preston (1996, Biometrics 52, 1472-1477) as the probability that a randomly selected species is present in both communities given that it is present in at least one community. Species overlap can thus be used to describe the similarity of two communities. In contrast with the parametric estimator of Smith et al., we prop...

This article concerns Ehresmann structures in the partition monoid P X . Since contains symmetric and dual inverse monoids on same base set , it naturally semilattices of idempotents both submonoids. We show that one these leads to an structure while other does not. explore some consequences this (structural/combinatorial representation theoretic), particular characterise largest left-, right- ...

Regular semigroups and their structures are the most wonderful part of semigroup theory, contents very rich. In order to explore more regular semigroups, this paper extends relevant classical conclusions from a new perspective: by transforming positions elements in regularity conditions, some conditions (collectively referred as transposition regularity) obtained, concepts various introduced (L...

New geochronological data and published structural and stratigraphic data show that two distinctly different ophiolitic assemblages formed in general proximity to one another at nearly the same time and were subsequently imbricated along a regional thrust zone. The Josephine ophiolite constitutes a complete oceanic crust and upper mantle sequence which lies within the western Jurassic belt of t...