A term is weakly shallow if each defined function symbol occurs either at the root or in the ground subterms, and a term rewriting system is weakly shallow if both sides of a rewrite rule are weakly shallow. This paper proves that non-E-overlapping, weakly-shallow, and noncollapsing term rewriting systems are confluent by extending reduction graph techniques in our previous work [SO10] with tow...

Addition of anionic polyacrylamide (PAM) to agricultural irrigation water can dramatically reduce erosion of soils. However, the toxicity of PAM to aquatic life, while often claimed to be low, has not been thoroughly evaluated. Five PAM formulations, including two oil-based products, one water-based product, one granular product and one tablet product, were evaluated for acute and/or chronic to...

Most P losses from surface-irrigated fields occur via runoff, are associated with eroded sediment, and can be minimized by eliminating irrigation-induced erosion. A convenient new practice that eliminates furrow irrigation-induced soil losses uses a high molecular weight, anionic polyacrylamide (PAM) applied to initial irrigation inflows. We hypothesized that, compared to control furrows, PAM t...

Prior studies of the phytoplankton dynamics in South San Francisco Bay, California, USA have hypothesized that bivalve filter-feeders are responsible for the limited phytoplankton blooms in the system. This study was designed to examine the effects of benthic grazing and light attenuation on this shallow, turbid, and nutrient replete system. We found that grazing by shallow water bivalves was i...

Shallow-water tropical reefs and the deep sea represent the two most diverse marine environments. Understanding the origin and diversification of this biodiversity is a major quest in ecology and evolution. The most prominent and well-supported explanation, articulated since the first explorations of the deep sea, holds that benthic marine fauna originated in shallow, onshore environments, and ...

Many current theories of human problem solving and skill acquisition assume that people work only on the unsatisfied goal that was created most recently. That is, the architecture obeys a last-in-first-out (LIFO) constraint on the selection of goals. This restriction seems necessary for the proper functioning of automatic learning mechanisms, such as production compilation and chunking. It is a...

Route directions are usually conveyed either by graphical means, i.e. by illustrating the route in a map or drawing a sketch-maps or, linguistically by giving spoken or written route instructions, or by combining both kinds of external representations. In most cases route directions are given in advance, i.e. prior to the actual traveling. But they may also be communicated quasisimultaneously t...

This paper describes a shallow parsing formalism aiming at machine translation between closely related languages. The formalism allows to write grammar rules helping to (partially) disambiguate chunks in input sentences. The chunks are then translatred into the target language without any deep syntactic or semantic processing. A stochastic ranker then selects the best translation according to t...

The turbidity of lakes is generally considered to be a smooth function of their nutrient status. However, recent results suggest that over a range of nutrient concentrations, shallow l&es can have two alternative equilibria: a clear state dominated by nquatic vegetation, and a turbid state characterized by high algal biomass. This bi-stability has important implications for the possibilities of...

This review article identifies and discusses some of main issues and potential problems – paradoxes and pathologies – around the communication of recorded information, and points to some possible solutions. The article considers the changing contexts of information communication, with some caveats about the identification of ‘pathologies of information’, and analyses the changes over time in th...