Adaptive decision-making requires that environmental contingencies between decision options and their relative advantages and disadvantages be assessed accurately and quickly. The research presented in this article addresses the challenging notion that contingencies may be more visible from small than large samples of observations. An algorithmic account for such a ""less-is-more"" effect is offered within a threshold-based decision framework. Accordingly, a choice between a pair of options is only made when the contingency in the sample that describes the relative utility of the two options exceeds a critical threshold. Small samples - due to their instability and the high dispersion of their sampling distribution - facilitate the generation of above-threshold contingencies. Across a broad range of parameter values, the resulting small-sample advantage in terms of hits is stronger than their disadvantage in terms of false alarms. Computer simulations and experimental findings support the predictions derived from the threshold model. In general, the relative advantage of small samples is most apparent when information loss is low, when decision thresholds are high, and when ecological contingencies are weak to moderate.
A review. The main focus and efforts for the next few years in the area of emulsion technol. will be to improve stability and control the release of active matter in double emulsions (3rd World Congress on Emulsions, Lyon, France, Sept. 2002). Almost any possible blends of low-mol. wt. emulsifiers, oils, cosolvents and coemulsifiers were already tested. Biopolymers, synthetic graft and comb co-polymers and polymerizable emulsifiers that impart steric or mech. stabilization with improved stability and better controlled release were explored. Amphiphilic macromols., natural occurring or synthetic, that increase the viscosity of each of the phases, complex with the oil or the emulsifiers and form systems that will behave much like microcapsules, microspheres and/or mesophasic liq. crystals were mentioned as possible new technologies for improved stability. This review will conc. only on the most recent findings that can enhance stability of the double emulsions and/or will reduce droplets sizes for potential food applications. The attempts and achievements include: selection of food-grade blends of emulsifiers to enhance emulsion stability at both inner and outer interfaces and use of new polymeric amphiphiles (carriers, complexing agents, natural polymeric emulsifiers) to control and reduce the reverse micellar transport phenomena and to control the addenda transport. [on SciFinder(R)]
El contacto entre el portugués y el español de los sefardíes que encontraron refugio en el Imperio Otomano después de la expulsión de los reinos de Castilla y Aragón en 1492, se manifiesta ya desde mediados del siglo XVI. Sin embargo, fue durante los siglos XVII y XVIII cuando este contacto fue más intenso. Paradójicamente, en los textos sefardíes del siglo XVIII se aprecia un claro descenso del componente portugués en comparación con los textos del siglo XVI. En esta investigación se analizan algunos aspectos de esta cuestión y los resultados lingüísticos de origen luso del judeoespañol.
This study investigated elements of pedagogical knowledge when students’ higher order thinking was an explicit and focused instructional goal. The findings suggest a model that consists of 6 elements. It seems that, for all these elements, the source of differences between teachers’ various pedagogies may be tracked to the basic distinction between a traditional transmission-of-knowledge approach to instruction versus a reform oriented constructivist approach. The findings portray how these two pedagogies are played out when higher order thinking is viewed as a distinct educational goal. Appropriate activities are insufficient for students’ active thinking. In the absence of adequate pedagogies, teachers adopt algorithmic approaches for teaching thinking that decrease the cognitive demands of tasks. Practical recommendations are discussed.
