A thermodynamic and kinetic analysis of solvent-enhanced selectivity in monophasic and biphasic reactor systems.

Selectivity control in biomass conversion is often realized by manipulating the solvent environment. Outcomes can be rationalized through a thermodynamically rigorous application of transition-state theory. We show that solvent-induced perturbations to selectivity in both monophasic and biphasic reactor systems are governed by the same underlying principles.

An electrophysiological analysis of modality-specific aspects of word repetition.

Priming effects to words are reduced when modality changes from study to test. This change was examined here using behavioral and electrophysiological measures of priming. During the study, half of the words were presented visually and half auditorally; during a subsequent lexical decision test, all words were presented visually. Lexical decisions were faster for within- than cross-modality repetitions. In contrast, modality influenced recognition only for low-frequency words. During lexical decision, event-related brain potentials were more positive to studied than unstudied words (200-500 ms). A larger and shorter duration effect was observed for within- than cross-modality repetitions (300-400 ms). This later effect is viewed as an electrophysiological index of modality-specific processing associated with priming. Results suggest that multiple events--both modality-specific and modality-nonspecific--underlie perceptual priming phenomena.

Electrophysiological insights into the nature of the semantic deficit in Alzheimer's disease.

Event-related brain potential (ERP) and reaction-time measures were used to determine if the specificity of a category prime differentially affects the amount of semantic priming seen in patients with dementia of the Alzheimer type (DAT) compared with normal elderly and young controls. Subjects were primed with an auditory category name followed by the visually presented name of an imageable object and indicated whether the object was a category member; the category was either superordinate to, at, or subordinate to the basic level. All groups showed similar priming effects in response to the category manipulation, as evidenced in both reaction time and the amplitude of the N400 component of the ERP. Overall, DAT subjects showed the smallest ERP priming effects and young controls the largest. The present study did not provide evidence for a strong version of a strictly "bottom-up" breakdown of the semantic networks in subjects with DAT, suggesting a role for factors such as task difficulty and memory search strategies in online categorization tasks of this type.