פרסומים

Major psychological theories of generalized anxiety disorder (GAD) have begun to suggest that worry may function as avoidance of emotions. On the basis of these findings, a number of researchers have begun to develop techniques to address emotional deficits in GAD. However, most techniques suggested to date have been from outside a cognitive-behavioral (CBT) model of treatment, making the integration of these techniques more difficult for CBT therapists. We propose a CBT model of addressing emotional avoidance through (a) learning to identify emotions and their possible evolutionary functions, (b) creating an emotion hierarchy to systematically address different emotions, (c) using imaginal exposure to increase tolerance to different emotions, and (d) eliminating behavioral avoidance of emotional experiences.

Crystal growth of calcium hydrogenphosphate dihydrate (DCPD), in the presence of polyaspartic acid or calcium phytate (system A), as well as nucleation and growth of octacalcium phosphate (OCP), in the presence of poly-l-lysine, poly-l-glutamic acid or polystyrene sulfonate (system B) have been investigated. In system A crystallization of DCPD was inhibited and the crystal growth morphology was specifically modified by preferential interaction of the respective additive with the dominant (010) crystal face. In system B crystals were formed via precursor phase(s) and polyelectrolytes exhibited dual action, at low concentrations inducing and at high concentrations inhibiting nucleation of the crystalline phase. Crystal/additive interactions controlling growth were nonspecific and resulted in smaller crystals with rounded edges, but with the same basic orientation as in the controls.

The main focus and efforts for the next few years in the area of emulsion technology will be to improve stability and control the release of active matter in double emulsions (3rd World Congress on Emulsions, Lyon, France, September 2002). Almost any possible blends of low-molecular weight emulsifiers, oils, cosolvents and coemulsifiers have been already tested. Biopolymers, synthetic graft and comb co-polymers and polymerizable emulsifiers that impart steric or mechanical stabilization with improved stability and better controlled release were explored. Amphiphilic macromolecules, 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 liquid crystals have been mentioned as possible new technologies for improved stability. This review will concentrate 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. (C) 2004 Elsevier B.V. All rights reserved.

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.

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.

The ability of a mixed lipid bilayer composed of neutral and charged lipids to encapsulate an oppositely charged protein is studied with use of a simple theoretical model. The free energy of the bilayer-enveloped protein complex is expressed as a sum of electrostatic and curvature elasticity contributions, and compared to that of a protein adsorbed on a mixed planar bilayer. The electrostatic adsorption energy on the planar bilayer is calculated by using an extended Poisson-Boltzmann approach, which allows for local lipid charge modulation in the adsorption zone. We find that the electrostatic interactions favor the wrapped state, while the bending energy prefers the planar bilayer. To enable the transition from the adsorbed to enveloped protein geometry, there is a minimal necessary protein charge. This ‘‘crossover’’ charge depends on the bending rigidity of the lipid membrane and the (composition dependent) spontaneous curvature of its constituent monolayers. The values for the crossover charge predicted by the theory are in line with the charge necessary for peptide shuttles to penetrate cell membranes.

In this paper we present the structural characterization of a five-component food-grade microemulsion containing Tween 80, R(+)limonene, ethanol, glycerol, and water. Our main approach to investigating the microstructure of dense microemulsions, and how it can be influenced by the various components, was to employ small-angle neutron scattering and the new evaluation technique for dense, interacting systems, the Generalized Indirect Fourier Transformation. We started our investigation with the impact of glycerol and ethanol on Tween 80 micelles in water. We found that glycerol increases the aggregation number and withdraws the hydrating agents from the head-group region of the surfactant, resulting in a higher packing density of molecules in a micelle at slightly increasing size. The same trend holds when the micelles are oil swollen and/or ethanol is present. Ethanol, on the other hand, redistributes mainly between water and the interface-headgroup region of the surfactant. Part of it replaces surfactant molecules in the micelles, which increases the available interface and results in a higher number of micelles with shrinking size. The same trend holds when the micelles are oil swollen and/or glycerol is present in the aqueous phase. We also investigated samples along the dilution of a mixture of surfactant and oil phase (R(+)-limonene and ethanol), which can be diluted with aqueous phase (mixture of water and glycerol) without the occurrence of phase separation. In some samples of this dilution most probably bicontinuous structures are present. To elucidate this point, we also employed dynamic light scattering, viscosity, and conductivity measurements. (C) 2004 Elsevier Inc. All rights reserved.