Reasoning with Intensional Negative Adjectivals: Semantics, Pragmatics, and Context

Intensional negative adjectives alleged , artificial , fake , false , former , and toy are unusual adjectives that depending on context may or may not be restricting functions. A formal theory of their semantics, pragmatics, and context that uniformly accounts for their complex mathematical and computational characteristics and captures some peculiarities of individual adjectives is presented.
Such adjectives are formalized as new concept builders, negation‐like functions that operate on the values of intensional properties of the concepts denoted by their arguments and yield new concepts whose intensional properties have values consistent with the negation of the old values. Understanding these new concepts involves semantics, pragmatics and context‐dependency of natural language. It is argued that intensional negative adjectives can be viewed as a special‐purpose, weaker, conntext‐dependent negationin natural language. The theory explains and predicts many inferences licensed by expressions involving such adjectives. Implementation of sample examples demonstrates its computational feasibility. Computation of context‐dependent interpretation is discussed.
The theory allows one to enhance a knowledge representation system with similar concept building, negation‐like, context‐dependent functions, the availability of which appears to be a distinct characteristic of natural languages.     

In vitro availability of minerals from oat products

The content of macroelements P, Mg and Ca and microelements Mn, Fe, Zn and Cu was determined in 10 commercially sold oat products made by different technological processes (dehulling, instantinising, extrusion, flaking). Phosphorus was the most prevalent of the macroelements (from 240.8 ± 2.2 to 845.5 ± 8.1 mg per 100 g), followed by magnesium (from 73.2 ± 0.7 to 271.9 ± 2.7 mg per 100 g) and calcium (from 30.69 ± 0.01 to 112.7 ± 0.3 mg per 100 g). The Ca/P ratio ranged from 1:5.3 in crushed oat to 1:8.2 in oat flakes. Regarding the microelements, manganese was present at the highest concentrations (from 2.62 ± 0.02 to 8.69 ± 0.01 mg per 100 g). The content of iron was similar and that of zinc not much lower, whereas the amount of copper was considerably smaller (from 0.23 ± 0.002 to 0.59 ± 0.002 mg per 100 g). The highest concentrations of mineral elements were found in instant oat bran flakes and the lowest in extruded oat and corn crisps containing 50% corn grouts. Samples of the products analysed were subjected to in vitro enzymatic digestion, simulating the digestive process occurring in the human alimentary tract. The supernatants thus obtained were analysed for their content of the previously determined mineral components; the percentage of minerals released from the products was calculated. The following sequence of mineral components released was observed: Cu (57.2–95.6%) > P (39.7–60.9%) > Ca (18.2–39.5%) > Mg (16.4–39.8%) > Mn (6.4–24.7%) > Fe (6.5–29%) > Zn (11–17.2%). The Ca/P ratio in the supernatant worsened from 1:8.2 in crushed oat to 1:23.3 in extruded oat and corn crisps. Crushed oat released the highest amounts of mineral elements during enzymatic hydrolysis, with oat grouts coming second. As regards the other products, it is difficult to establish their relative sequence in the release of minerals. © 2002 Society of Chemical Industry     

Heterogeneity and common features of defective hepatitis B virus genomes derived from spliced pregenomic RNA

We have investigated the effect of the venom of a Chilean tarantula, Phrixotrichus spatulatus, on cell contraction, intracellular [Ca2+] ([Ca2+]i), and the L-type Ca2+ current (ICa,L) in cells isolated from the ventricles of guinea pig hearts. Whole-cell voltage clamp techniques were used to monitor ICa,L. The action potential was recorded using whole cell current clamp. [Ca2+]i was monitored using the fluorescent indicator indo-1. The venom of P. spatulatus decreased ICa,L in a dilution-dependent manner, with half-maximal inhibition at a dilution of 1.1/10(4) (v/v). At a dilution of 1/10(4), this inhibition occurred at all potentials so that the current-voltage relationship of ICa,L was depressed. However, inhibition of ICa,L by the venom was relieved by positive potentials, the venom being less effective following pulses to positive potentials. The venom reduced the duration of the action potential (at 50% repolarization) by between 26 and 43%. The venom also decreased the amplitude of the [Ca2+]i transient and cell contraction. It is concluded that the venom of P. spatulatus is a potent, voltage-dependent inhibitor of ICa,L; this inhibition of ICa,L may account for the effects of the venom on action potential duration, [Ca2+]i, and contraction.     

Logical reasoning in natural language: It is all about knowledge

A formal, computational, semantically clean representation of natural language is presented. This representation captures the fact that logical inferences in natural language crucially depend on the semantic relation of entailment between sentential constituents such as determiner, noun, adjective, adverb, preposition, and verb phrases.The representation parallels natural language in that it accounts for human intuition about entailment of sentences, it preserves its structure, it reflects the semantics of different syntactic categories, it simulates conjunction, disjunction, and negation in natural language by computable operations with provable mathematical properties, and it allows one to represent coordination on different syntactic levels.The representation demonstrates that Boolean semantics of natural language can be successfully modeled in terms of representation and inference by knowledge representation formalisms with Boolean semantics. A novel approach to the problem of automatic inferencing in natural language is addressed. The algorithm for updating a computer knowledge base and reasoning with explicit negative, disjunctive, and conjunctive information based on computing subsumption relation between the representations of the appropriate sentential constituents is discussed with examples.