Discourse Markers and Modal Expressions in Speakers with and without Asperger Syndrome: A Pragmatic-Perceptive Approach

From a theoretical point of view, this paper offers a new framework for the analysis of discourse markers: a pragmatic-perceptive model that emphasizes the point of the communication process in which such particles become more relevant. Furthermore, this approach tries to give an account of the modal expressions (attenuators and intensifiers) that speakers use in oral speech. The quotients of absolute and relative frequency with regard to the use of textual, interactive and enunciative markers - focused on the message, the addressee and the addresser respectively - are compared in two samples of 20 subjects with typical development and other 20 with Asperger syndrome. The general results of this research suggest that these latter speakers display a suitable command of textual markers, whereas they overexploit the enunciative ones in conversation

Giant magnetoresistance in ultra-small Graphene based devices

By computing spin-polarized electronic transport across a finite zigzag graphene ribbon bridging two metallic graphene electrodes, we demonstrate, as a proof of principle, that devices featuring 100% magnetoresistance can be built entirely out of carbon. In the ground state a short zig-zag ribbon is an antiferromagnetic insulator which, when connecting two metallic electrodes, acts as a tunnel barrier that suppresses the conductance. Application of a magnetic field turns the ribbon ferromagnetic and conducting, increasing dramatically the current between electrodes. We predict large magnetoresistance in this system at liquid nitrogen temperature and 10 Tesla or at liquid helium temperature and 300 Gauss.Comment: 4 pages, 4 figure