5,913 research outputs found
Security and confidentiality approach for the Clinical E-Science Framework (CLEF)
Objectives: CLEF is an MRC sponsored project in the E-Science programme that aims to establish methodologies and a technical infrastructure for the next generation of integrated clinical and bioscience research. Methods: The heart of the CLEF approach to this challenge is to design and develop a pseudonymised repository of histories of cancer patients that can be accessed by researchers. Robust mechanisms and policies have been developed to ensure that patient privacy and confidentiality are preserved while delivering a repository of such medically rich information for the purposes of scientific research. Results: This paper summarises the overall approach adopted by CLEF to meet data protection requirements, including the data flows, pseudonymisation measures and additional monitoring policies that are currently being developed. Conclusion: Once evaluated, it is hoped that the CLEF approach can serve as a model for other distributed electronic health record repositories to be accessed for research
Security and confidentiality approach for the Clinical E-Science Framework (CLEF)
CLEF is an MRC sponsored project in the E-Science programme that aims to
establish policies and infrastructure for the next generation of integrated clinical and
bioscience research. One of the major goals of the project is to provide a
pseudonymised repository of histories of cancer patients that can be accessed by
researchers. Robust mechanisms and policies are needed to ensure that patient
privacy and confidentiality are preserved while delivering a repository of such
medically rich information for the purposes of scientific research. This paper
summarises the overall approach adopted by CLEF to meet data protection
requirements, including the data flows and pseudonymisation mechanisms that are
currently being developed. Intended constraints and monitoring policies that will
apply to research interrogation of the repository are also outlined. Once evaluated, it
is hoped that the CLEF approach can serve as a model for other distributed
electronic health record repositories to be accessed for research
Persistence to high temperatures of interlayer coherence in an organic superconductor
The interlayer magnetoresistance of the organic metal \cuscn is
studied in fields of up to 45 T and at temperatures from 0.5 K to 30 K. The
peak in seen in in-plane fields, a definitive signature of
interlayer coherence, remains to s exceeding the Anderson criterion for
incoherent transport by a factor . Angle-dependent magnetoresistance
oscillations are modeled using an approach based on field-induced quasiparticle
paths on a 3D Fermi surface, to yield the dependence of the scattering rate
. The results suggest that does not vary strongly over
the Fermi surface, and that it has a dependence due to electron-electron
scattering
A statistical model for the intrinsically broad superconducting to normal transition in quasi-two-dimensional crystalline organic metals
Although quasi-two-dimensional organic superconductors such as
-(BEDT-TTF)Cu(NCS) seem to be very clean systems, with apparent
quasiparticle mean-free paths of several thousand \AA, the superconducting
transition is intrinsically broad (e.g K wide for K).
We propose that this is due to the extreme anisotropy of these materials, which
greatly exacerbates the statistical effects of spatial variations in the
potential experienced by the quasiparticles. Using a statistical model, we are
able to account for the experimental observations. A parameter , which
characterises the spatial potential variations, may be derived from
Shubnikov-de Haas oscillation experiments. Using this value, we are able to
predict a transition width which is in good agreement with that observed in MHz
penetration-depth measurements on the same sample.Comment: 8 pages, 2 figures, submitted to J. Phys. Condens. Matte
Wormholes and Flux Tubes in 5D Kaluza-Klein Theory
In this paper spherically symmetric solutions to 5D Kaluza-Klein theory, with
``electric'' and/or ``magnetic'' fields are investigated. It is shown that the
global structure of the spacetime depends on the relation between the
``electrical'' and ``magnetic'' Kaluza-Klein fields. For small ``magnetic''
field we find a wormhole-like solution. As the strength of the ``magnetic''
field is increased relative to the strength of the ``electrical'' field, the
wormhole-like solution evolves into a finite or infinite flux tube depending on
the strengths of the two fields. For the large ``electric'' field case we
conjecture that this solution can be considered as the mouth of a wormhole,
with the , and components of the metric acting as
the source of the exotic matter necessary for the formation of the wormhole's
mouth. For the large ``magnetic'' field case a 5D flux tube forms, which is
similar to the flux tube between two monopoles in Type-II superconductors, or
the hypothesized color field flux tube between two quarks in the QCD vacuum.Comment: 12 pages, 5 eps.figures, REVTEX, Discussion about null surfaces
ammended. References added. To be published in PR
Glueball Spin
The spin of a glueball is usually taken as coming from the spin (and possibly
the orbital angular momentum) of its constituent gluons. In light of the
difficulties in accounting for the spin of the proton from its constituent
quarks, the spin of glueballs is reexamined. The starting point is the
fundamental QCD field angular momentum operator written in terms of the
chromoelectric and chromomagnetic fields. First, we look at the restrictions
placed on the structure of glueballs from the requirement that the QCD field
angular momentum operator should satisfy the standard commutation
relationships. This can be compared to the electromagnetic charge/monopole
system, where the quantization of the field angular momentum places
restrictions (i.e. the Dirac condition) on the system. Second, we look at the
expectation value of this operator under some simplifying assumptions.Comment: 11 pages, 0 figures; added references and some discussio
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