Free University of Berlin

About: Free University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Population & Context (language use). The organization has 35195 authors who have published 66525 publications receiving 2094403 citations. The organization is also known as: FU Berlin.

Optimism, Vulnerability, and self-beliefs as health-related cognitions: A systematic overview

Abstract: This paper disentangles a number of closely related cognitions by dividing them into the categories of defensive and functional optimism. Optimistic biases in risk perception are discussed that may represent barriers in the adoption of preventive health behaviors. Instead of defensive optimism, some sense of vulnerability is seen as indispensable for behavioral change operating jointly with beliefs about positive health outcomes, instrumental actions, and appropriate coping resources. A distinction is made between three kinds of functional optimism that depend either on attributional style, outcome expectancies, or personal agency. Findings are presented that corroborate the strength of these constructs in predicting health outcomes. In terms of health behavior change, it is argued that optimistic self-beliefs are the most beneficial because of their operative power that helps to set goals, initiate actions, and maintain motivation.

Curie temperature of ultrathin films of fcc-cobalt epitaxially grown on atomically flat Cu(100) surfaces.

Abstract: We have explored the relationship between epitaxial growth and magnetism in the case of ultrathin fcc-Co films by means of a multitechnique approach. For high-quality fcc-Co films less than 3 monolayers thick the Curie temperatures ${\mathrm{T}}_{\mathrm{C}}$ are dramatically lower than ${\mathrm{T}}_{\mathrm{C}}^{\mathrm{B}}$ of bulk fcc-Co and decease distinctly with film thickness. In contrast to previous claims, ${\mathrm{T}}_{\mathrm{C}}$ of a single monolayer appears to be far below 300 K. Substrate topology is found to strongly influence the structural perfection of the films which in turn determines their magnetic properties (Curie temperature, coercive field, and anisotropies).

Quantum speed limit for non-Markovian dynamics.

Abstract: We derive a Margolus-Levitin-type bound on the minimal evolution time of an arbitrarily driven open quantum system. We express this quantum speed limit time in terms of the operator norm of the nonunitary generator of the dynamics. We apply these results to the damped Jaynes-Cummings model and demonstrate that the corresponding bound is tight. We further show that non-Markovian effects can speed up quantum evolution and therefore lead to a smaller quantum speed limit time.