The Pragmatics of Pragmatic Language and the Curse of Ambiguity: An fMRI Study.

In pragmatic language, there is an intentional distinction between the literal meaning of what is said, and what the speaker actually means. Previous neuroimaging investigations of pragmatic language have contrasted it with literal language; however, such contrasts may have been confounded by the higher levels of ambiguity in pragmatic language. Here, we used functional magnetic resonance imaging (fMRI) to compare pragmatic sentences (specifically requiring the interpretation of nonliteral meaning in the form of hints) with unintentionally ambiguous scenarios. Analysis showed that ambiguous language activated brain areas recognized to play a role in generating a theory of mind (ToM) that have previously been argued to support understanding of pragmatic language, specifically medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and temporoparietal junction (TPJ). In contrast, the pragmatic scenarios drew on anterior temporal, superior parietal lobule, in addition to precuneus. While no effect of gender was found for unintentionally ambiguous stimuli, females showed greater activity than males within mPFC and inferior frontal gyrus (IFG) for pragmatic scenarios - regions thought to be involved in cognitive and affective empathy, respectively. Findings suggest that while areas underpinning ToM are sufficient to support meaning derivation in the context of ambiguity, reasoning about pragmatic intent is more reliant on access to self-referential memory.

Total organic carbon analysis as a precursor to disinfection byproducts in potable water: oxidation technique considerations.

In recent years, an increasing number of regulations and methodologies have begun to utilize total organic carbon (TOC) analysis for monitoring microbial contamination and/or disinfectant byproduct (DBP) precursors. This paper highlights some analytical differences and similarities between the two widely used TOC oxidation techniques: UV persulfate and high temperature combustion (HTC). Previous papers have come to different and sometimes contradictory conclusions on this subject. However, these studies either compared instruments with significantly different flow paths or TOC systems from different eras. Unlike previous studies, this paper compares two modern TOC analyzers with nearly identical flow paths for sample recovery, detection limits, and analysis of real world samples. On average, both persulfate and HTC oxidation yielded good recoveries for 10 hard to oxidize compounds and potable water samples from 5 different locations across the USA. In general, persulfate yielded more precise results because of its lower background response relative to sample response while HTC gave slightly higher results (roughly 2% to 3%) for surface water samples.