BACKGROUND Sponges have long been known to be ecologically important members of the benthic fauna on coral reefs. Recently, it has been shown that sponges are also important contributors to the nitrogen biogeochemistry of coral reefs. The studies that have been done show that most sponges are net sources of dissolved inorganic nitrogen (DIN; NH4 (+) and NO3 (-)) and that nitrification, mediated...

Availability and leaching of dissolved inorganic N (DIN = NH4 + NO3) in soil were measured in a periodically flooded forest of the Central Amazon floodplain (v rzea) during one terrestrial phase. Special emphasis was on the effects of a legume and a nonlegume tree species. NH4-N accounted for more than 85% of DIN even at the end of the terrestrial phase although it decreased throughout the expe...

It has been claimed that counterpart theory cannot support a theory of actuality without rendering obviously invalid formulas valid or obviously valid formulas invalid. We argue that these claims are not based on logical flaws of counterpart theory itself, but point to the lack of appropriate devices in first-order logic for “remembering” the values of variables. We formulate a mildly dynamic v...

a Emory University School of Medicine, Atlanta, USA b Professional Wellbeing Committee WFSA, USA c Harvard University, Department of Anesthesia, Boston, USA d Committee of Chemical Dependence Massachusetts General Hospital, Harvard University, Boston, USA e Penn Medicine University, Department of Anesthesia, Philadelphia, USA f Occupational Health Committee of Brazilian Society of Anesthesiolog...

We show that the actuality operator A is redundant in any propositional modal logic characterized by a class of Kripke models (respectively, neighborhood models). Specifically, we prove that for every formula φ in the propositional modal language with A, there is a formula ψ not containing A such that φ and ψ are materially equivalent at the actual world in every Kripke model (respectively, nei...