3,406 research outputs found
Combinatorics of Hard Particles on Planar Graphs
We revisit the problem of hard particles on planar random tetravalent graphs
in view of recent combinatorial techniques relating planar diagrams to
decorated trees. We show how to recover the two-matrix model solution to this
problem in this purely combinatorial language.Comment: 35 pages, 20 figures, tex, harvmac, eps
The importance of the electronic contribution to linear magnetoelectricity
We demonstrate that the electronic contribution to the linear magnetoelectric
response, usually omitted in first-principles studies, can be comparable in
magnitude to that mediated by lattice distortions, even for materials in which
responses are strong. Using a self-consistent Zeeman response to an applied
magnetic field for noncollinear electron spins, we show how electric
polarization emerges in linear magnetoelectrics through both electronic- and
lattice-mediated components -- in analogy with the high- and low-frequency
dielectric response to an electric field. The approach we use is conceptually
and computationally simple, and can be applied to study both linear and
non-linear responses to magnetic fields.Comment: 5 pages, 3 figure
The hidden burden of adult allergic rhinitis : UK healthcare resource utilisation survey
Funding Funding for this survey was provided by Meda Pharma.Peer reviewedPublisher PD
Managing the Ethical Dimensions of Brain-Computer Interfaces in eHealth: An SDLC-based Approach
A growing range of brain-computer interface (BCI) technologies is being employed for purposes of therapy and human augmentation. While much thought has been given to the ethical implications of such technologies at the ‘macro’ level of social policy and ‘micro’ level of individual users, little attention has been given to the unique ethical issues that arise during the process of incorporating BCIs into eHealth ecosystems. In this text a conceptual framework is developed that enables the operators of eHealth ecosystems to manage the ethical components of such processes in a more comprehensive and systematic way than has previously been possible. The framework’s first axis defines five ethical dimensions that must be successfully addressed by eHealth ecosystems: 1) beneficence; 2) consent; 3) privacy; 4) equity; and 5) liability. The second axis describes five stages of the systems development life cycle (SDLC) process whereby new technology is incorporated into an eHealth ecosystem: 1) analysis and planning; 2) design, development, and acquisition; 3) integration and activation; 4) operation and maintenance; and 5) disposal. Known ethical issues relating to the deployment of BCIs are mapped onto this matrix in order to demonstrate how it can be employed by the managers of eHealth ecosystems as a tool for fulfilling ethical requirements established by regulatory standards or stakeholders’ expectations. Beyond its immediate application in the case of BCIs, we suggest that this framework may also be utilized beneficially when incorporating other innovative forms of information and communications technology (ICT) into eHealth ecosystems
Incipient ferroelectricity in 2.3% tensile-strained CaMnO3 films
Epitaxial CaMnO3 films grown with 2.3% tensile strain on (001)-oriented
LaAlO3 substrates are found to be incipiently ferroelectric below 25 K. Optical
second harmonic generation (SHG) was used for the detection of the incipient
polarization. The SHG analysis reveals that CaMnO3 crystallites with in-plane
orientation of the orthorhombic b axis contribute to an electric polarization
oriented along the orthorhombic a (resp.\ c) axis in agreement with the
predictions from density functional calculations
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