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.     

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.     

Anomalous atomic hydrogen shock pattern in a supersonic plasma Jet

A two-photon laser-induced fluorescence study on the transport of ground-state atomic hydrogen in a supersonic plasma jet, generated from an Ar-H (2) mixture, reveals an unexpected shock pattern. Whereas both the axial-velocity profile and the temperature profile of hydrogen atoms along the jet centerline can be interpreted in terms of a supersonic expansion of an Ar-H gas mixture, the H-atom density profiles do not satisfy the well established Rankine-Hugoniot relation leading to a nonconservation of the forward flux. The experimental results show that H atoms escape from the supersonic expansion by a diffusion process due to strong density gradients between the core of the jet and its vicinity.     

Aqueous two-phase systems for protein separation: a perspective

Aqueous two-phase systems (ATPS) that are formed by mixing a polymer (usually polyethylene glycol, PEG) and a salt (e.g. phosphate, sulphate or citrate) or two polymers and water can be effectively used for the separation and purification of proteins. The partitioning between both phases is dependent on the surface properties of the proteins and on the properties of the two phase system. The mechanism of partitioning is complex and not very easy to predict but, as this review paper shows, some very clear trends can be established. Hydrophobicity is the main determinant in the partitioning of proteins and can be measured in many different ways. The two methods that are more attractive, depending on the ATPS used (PEG/salt, PEG/polymer), are those that consider the 3-D structure and the hydrophobicity of AA on the surface and the one based on precipitation with ammonium sulphate (parameter 1/m*). The effect of charge has a relatively small effect on the partitioning of proteins in PEG/salt systems but is more important in PEG/dextran systems. Protein concentration has an important effect on the partitioning of proteins in ATPS. This depends on the higher levels of solubility of the protein in each of the phases and hence the partitioning observed at low protein concentrations can be very different to that observed at high concentrations. In virtually all cases the partition coefficient is constant at low protein concentration (true partitioning) and changes to a different constant value at a high overall protein concentration. Furthermore, true partitioning behavior, which is independent of the protein concentration, only occurs at relatively low protein concentration. As the concentration of a protein exceeds relatively low values, precipitation at the interface and in suspension can be observed. This protein precipitate is in equilibrium with the protein solubilized in each of the phases. Regarding the effect of protein molecular weight, no clear trend of the effect on partitioning has been found, apart from PEG/dextran systems where proteins with higher molecular weights partitioned more readily to the bottom phase. Bioaffinity has been shown in many cases to have an important effect on the partitioning of proteins. The practical application of ATPS has been demonstrated in many cases including a number of industrial applications with excellent levels of purity and yield. This separation and purification has also been successfully used for the separation of virus and virus-like particles.     

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates

Highly ordered arrays of Ni nanoholes and Fe₂₀Ni₈₀ antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.