Analysis of the phase behavior of the aqueous poly(ethylene glycol)-Ficoll system

The PEG-Ficoll polymer phase system is one that has been overlooked in the past for biotechnology applications because of the stability of its emulsions. However, new applications, such as emulsion coating of cells, are appearing that rely on this very property. Ficoll is highly polydisperse and multimodal with three distinct Ficoll peaks in gel permeation chromatography. As a result, the transition between one-phase and two-phase systems is blurred and the binodials obtained through turbidometric titration and tie-line analysis differ significantly. Moreover, since the three Ficoll peaks partition differently, tie-line analysis cannot be described by a simple model of the aqueous two-phase system. A simple modification to the model allowed for excellent fit, and this modification may prove well-suited for the many practical cases where aqueous two-phase systems fail to display parallel tie-lines as implicitly assumed in the simpler model.

Who will see me? The impact of type of audience on willingness to display group-mediated attitude-intention consistency

The present study examined the role that group norms, group identification, and imagined audience (in-group vs. out-group) play in attitude-behavior processes. University students (N = 187) participated in a study concerned with the prediction of consumer behavior. Attitudes toward drinking their preferred beer, subjective norm, perceived behavioral control, group norm, and group identification were assessed. Intentions and perceived audience reactions to consumption were assessed. As expected, group norms, identification, and imagined audience interacted to influence likelihood of drinking one's preferred beer and perceived audience reactions. High identifiers were more responsive to group norms in the presence of an in-group audience than an out-group audience. The present results indicate that audience concerns impact upon the relationship between attitude., and behavior.