Great expectations: Specific lexical anticipation influences the processing of spoken language

Background  

Recently several studies have shown that people use contextual information to make predictions about the rest of the sentence or story as the text unfolds. Using event related potentials (ERPs) we tested whether these on-line predictions are based on a message-level representation of the discourse or on simple automatic activation by individual words. Subjects heard short stories that were highly constraining for one specific noun, or stories that were not specifically predictive but contained the same prime words as the predictive stories. To test whether listeners make specific predictions critical nouns were preceded by an adjective that was inflected according to, or in contrast with, the gender of the expected noun.     

Rhetorical biset functors,rational p-biset functors and their semisimplicity in characteristic zero

Rhetorical biset functors can be defined for any family of finite groups that is closed under subquotients up to isomorphism. The rhetorical p-biset functors almost coincide with the rational p-biset functors. We show that, over a field with characteristic zero, the rhetorical biset functors are semisimple and, furthermore, they admit a character theory involving primitive characters of automorphism groups of cyclic groups.     

Reproducibility of magnetic resonance imaging measurements of spinal cord atrophy: the role of quality assurance.

A sensitive magnetic resonance imaging (MRI) method to measure spinal cord cross-sectional area with the potential to monitor disease progression has recently been developed. As changes in cord area due to disease are usually small, assessment of the reliability of the methodology is essential in serial studies of spinal cord atrophy. The aim of this study was to institute and evaluate a protocol of quality assurance to determine long-term reproducibility of serial studies. Serial MRI of the spinal cord was carried out in five healthy volunteer controls over 1 year. Cross-sectional spinal cord areas were measured in a total of 46 scans. The mean coefficient of variation of all subjects over one year was 1.35%. The intra-observer coefficient of variation for same scan analysis was 0.63%. This study has confirmed high reliability of our serial data over one year and the on-going quality assurance protocol enables continuing evaluation of the reproducibility of results in serial studies. Quality assurance is an essential and practical component of all serial MRI studies, without which the clinical implications of change cannot be reliably evaluated.     

Exploiting the Hydrogen Bond Donor/Acceptor Properties of PN‐Heterocycles: Selective Anion Receptors for Hydrogen Sulfate

We describe two novel hybrid receptors combining a phosphorus‐/nitrogen‐containing (PN) phosphonamidate heterocycle with urea recognition units in an arylethynyl backbone. Structural, spectroscopic and computational studies reveal that the origin of superior binding for hydrogen sulfate (HSO₄^?) anion is correlated with the formation of strong hetero‐complementary hydrogen bonds with the phosphonamidate motif. We further demonstrate that the hybrid host system is capable of capturing/transporting the HSO₄^? anion from an aqueous, biphasic system.     

Microwave heating of ceramic composites

The microwave heating of a ceramic composite is modelled andanalysed. The composite consists of many small ceramic particlesembedded in a ceramic cement. The composite is assumed to bewell insulated, and each particle is assumed to be in imperfectthermal contact with the surrounding cement. Based on thesetwo assumptions an asymptotic theory exploiting the small Biotnumber and small non-dimensional contact conductance is developed.Our asymptotic theory yields a set of nonlinear partial differentialequations which govern the temperature in the composite. Theseare reduced to a set of coupled nonlinear ordinary differentialequations in which the surface area of each particle entersas a parameter. Recent experiments with such composites haveshown that the steady-state temperature of the composite isstrongly dependent upon the radii of the embedded particles.Our model captures this effect. In fact, our analysis showsthat the assumption of imperfect thermal contact between theparticles and the ceramic cement is essential for this trendto be established.     

Controlling dispersion and transmission spectra of hybrid resonant-gas-filled photonic-crystal optical components

Using the model of an infinite one-dimensional periodic layered structure, we consider the possibilities of controlling dispersion properties and transmission spectra of hybrid optical components consisting of photonic band-gap structures filled with a resonant gas. It is shown that the combination of resonance-enhanced gas dispersion with the dispersion of a photonic band-gap structure may give rise to new features in the dispersion and transmission of hybrid spectral elements. These effects can be employed to create narrowband filters and ultrarefractive prisms with controllable parameters.     

Three-Dimensional Collagen Gel Networks for Neural Stem Cell-Based Neural Tissue Engineering

Stem and progenitor cells isolated from the embryonic rat cerebral cortex were immobilized by matrix entrapment in three-dimensional (3D) Type I collagen gels, and cultured in serum-free medium containing basic fibroblast growth factor. The cells trapped within the collagen networks actively proliferated and formed clone-like aggregates. Neurons were the first differentiated cells to appear within the aggregates, followed by generation of astrocytes and oligodendrocytes. In addition, necrotic cores were developed as the aggregate diameter increased and cell viability declined significantly after 3 weeks in culture. To overcome these problems, the cell-collagen constructs were transferred to Rotary Wall Vessel bioreactors for up to 10 weeks. In the rotary culture, the collagen gels compacted 3-4 folds and a long-term growth and differentiation of neural stem and progenitor cells was dynamically maintained. Remarkably, the cell-collagen constructs formed a complex two-layered structure that superficially emulated to a certain extent the cerebral cortex of the embryonic brain in architecture and functionality. The engineered 3D tissue-like constructs displaying characteristic properties of neuronal circuits may have potential use in tissue replacement therapy for injured brain and spinal cord.