University of Texas at Austin

About: University of Texas at Austin is a education organization based out in Austin, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 94352 authors who have published 206297 publications receiving 9070052 citations. The organization is also known as: UT-Austin & UT Austin.

A Meta-Analysis of Country-of-Origin Effects

Abstract: This note reports a quantitative analysis of the country-of-origin (COO) effect. Based on fifty-two articles or papers containing sixty-nine independent studies and 1,520 effect sizes, an analysis of fifteen study characteristics revealed that country-of-origin effects are only somewhat generalizable. Using omega-squared as the measure of effect size, verbal product descriptions produced larger COO effect sizes than did the presence of an actual product. Likewise, single-cue studies produced larger COO effect sizes than did multiple-cue studies, and larger samples produced effect sizes that on average were greater than those produced by smaller samples. The size of an observed COO effect was a function of whether the dependent variables was a quality/reliability perception or a purchase intention; the average effect size of quality/reliability perceptions was .30, whereas the average effect size for purchase intentions was .19. Purchase intentions were most susceptible to methodological artifacts than were quality/reliability perceptions. Study findings selectively confirm and refute common beliefs regarding the impact of a country-of-origin cue on product perceptions and purchase intentions.

Anisotropic self-assembly of spherical polymer-grafted nanoparticles

Abstract: It is easy to understand the self-assembly of particles with anisotropic shapes or interactions (for example, cobalt nanoparticles or proteins) into highly extended structures. However, there is no experimentally established strategy for creating a range of anisotropic structures from common spherical nanoparticles. We demonstrate that spherical nanoparticles uniformly grafted with macromolecules ('nanoparticle amphiphiles') robustly self-assemble into a variety of anisotropic superstructures when they are dispersed in the corresponding homopolymer matrix. Theory and simulations suggest that this self-assembly reflects a balance between the energy gain when particle cores approach and the entropy of distorting the grafted polymers. The effectively directional nature of the particle interactions is thus a many-body emergent property. Our experiments demonstrate that this approach to nanoparticle self-assembly enables considerable control for the creation of polymer nanocomposites with enhanced mechanical properties. Grafted nanoparticles are thus versatile building blocks for creating tunable and functional particle superstructures with significant practical applications.

Inverted-U dopamine D1 receptor actions on prefrontal neurons engaged in working memory.

Abstract: Dopamine (DA) D1 receptor (D1R) stimulation in prefrontal cortex (PFC) produces an 'inverted-U' dose-response, whereby either too little or too much D1R stimulation impairs spatial working memory. This response has been observed across species, including genetic linkages with human cognitive abilities, PFC activation states and DA synthesis. The cellular basis for the inverted U has long been sought, with in vitro intracellular recordings supporting a variety of potential mechanisms. The current study demonstrates that the D1R agonist inverted-U response can be observed in PFC neurons of behaving monkeys: low levels of D1R stimulation enhance spatial tuning by suppressing responses to nonpreferred directions, whereas high levels reduce delay-related firing for all directions, eroding tuning. These sculpting actions of D1R stimulation are mediated in monkeys and rats by cyclic AMP intracellular signaling. The evidence for an inverted U at the cellular level in behaving animals promises to bridge in vitro molecular analyses with human cognitive experience.