University of Kentucky

About: University of Kentucky is a education organization based out in Lexington, Kentucky, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 43933 authors who have published 92195 publications receiving 3256087 citations. The organization is also known as: UK.

Spontaneous interlayer coherence in double-layer quantum Hall systems: Charged vortices and Kosterlitz-Thouless phase transitions

Abstract: At strong magnetic fields, double-layer two-dimensional electron-gas systems can form an unusual broken-symmetry state with spontaneous interlayer phase coherence. In this paper we explore the rich variety of quantum and finite-temperature phase transitions associated with this broken symmetry. We describe the system using a pseudospin language in which the layer degree of freedom is mapped to a fictional spin 1/2 degree of freedom. With this mapping the spontaneous symmetry breaking is equivalent to that of a spin 1/2 easy-plane ferromagnet. In this language, spin textures can carry a charge. In particular, vortices carry \ifmmode\pm\else\textpm\fi{}e/2 electrical charge and vortex-antivortex pairs can be neutral or carry charge \ifmmode\pm\else\textpm\fi{}e. We derive an effective low-energy action and use it to discuss the charged and collective neutral excitations of the system. We have obtained the parameters of the Landau-Ginzburg functional from first-principles estimates and from finite-size exact diagonalization studies. We use these results to estimate the dependence of the critical temperature for the Kosterlitz-Thouless phase transition on layer separation.

International Union of Pharmacology. XXI. Structure, distribution, and functions of cholecystokinin receptors.

Abstract: The peptide cholecystokinin (CCK)2was originally discovered in the gastrointestinal tract ([Ivy and Oldberg, 1928][1]) and has been shown to mediate pancreatic secretion and contraction of gallbladder. Then, CCK was described in the mammalian central nervous system (CNS) as a gastrin-like

Group 13 compounds incorporating Salen ligands.

Abstract: In a previous review it was predicted that "the reactivity of five-coordinate complexes would certainly be different than that of the four-coordinate derivatives". Structurally and spectroscopically, there is very little difference in the higher-coordinate compounds when compared to the four-coordinate derivatives. However, the prediction was remarkably accurate, if not a bit understated, for the reactivity of these compounds. There appears to be a tremendous potential in catalysis and synthesis for the five-coordinate derivatives, far more possibilities than exist for the lower-coordinate derivatives. Furthermore, the higher-coordinate derivatives are rarely air or moisture sensitive and, thus, may be handled under a wider range of conditions. Although reactions such as oxirane and lactide polymerizations are fairly well-known now with five- and six-coordinate aluminum compounds, the potential of these compounds has only begun to be developed. It is easy to imagine that these types of compounds will see wider use than the related transition-metal compounds.

Standing up for a change: reducing bias through interpersonal confrontation.

Abstract: Three experiments examined the effectiveness of interpersonal confrontations as a means for decreasing stereotypic responding. After making stereotypic inferences about Black individuals, participants were confronted and reactions were measured across various intrapersonal and interpersonal response domains. Confrontations varied in level of hostility (Experiment 1) and whether they were expressed by a Black or White person (Experiment 2). Results indicate that although confrontations (and particularly hostile ones) elicited negative emotions and evaluations toward the confronter, participants also experienced negative self-directed affect. Furthermore, regardless of who did the confronting or how much hostility was expressed, confronted participants subsequently were less likely to provide stereotypic responses (Experiments 1-2), and the effect of the confrontation generalized to reporting less prejudiced attitudes (Experiment 3).