10,323 research outputs found
[Review of] Arjun Appadurai, Modernity at Large, Cultural Dimensions of Globalization
Modernity at Large is a collection of essays (most of which are reprinted from other sources, e.g., Public Culture) that link the themes of modernity and globalization to contemporary everyday social practice, and to group individual identity construction and expression. Appadurai takes up the conditions of modernity which for him include science as a dominant ideology, obsession with technological development, colonial social relations, and the primacy of national communities. Weaving these conditions with issues of globalization, which he defines as instantaneous worldwide telecommunications (phone, fax, and internet), increased international or transnational migration, the expanding scope and impact of mass media, and the surge in global tourism
Flow cytometric detection of gamma interferon can effectively discriminate Mycobacterium bovis BCG-vaccinated cattle from M. bovis-infected cattle
Mycobacterium bovis is the causative agent of bovine tuberculosis, a disease that is increasing in incidence in United Kingdom cattle herds. In addition to increasing economic losses, the rise in bovine tuberculosis poses a human health risk. There is an urgent requirement for effective strategies for disease eradication; this will likely involve vaccination in conjunction with current test and slaughter policies. A policy involving vaccination would require an accurate diagnosis of M. bovis-infected animals and the potential to distinguish these animals from vaccinates. Currently used diagnostic tests, the skin test and gamma interferon (IFN-γ) blood test, have a sensitivity of up to 95%. A further complication is that M. bovis BCG-vaccinated animals are also scored positive by these tests. We tested the hypothesis that the quantification of IFN-γ-producing lymphocytes by flow cytometric analysis of intracellular IFN-γ expression would provide a more accurate discrimination of M. bovis-infected animals from BCG vaccinates. Significant numbers of IFN-γ-expressing CD4(+) T cells were detected following culture of heparinized blood from M. bovis-infected animals, but not from BCG vaccinates, with purified protein derived from M. bovis (PPD-B) or live mycobacteria. Only 1 of 17 BCG-vaccinated animals had a significant number of CD4(+) T lymphocytes expressing IFN-γ, compared with 21/22 M. bovis-infected animals. This assay could allow an accurate diagnosis of M. bovis and allow the discrimination of BCG-vaccinated cattle from infected cattle
The Born and Markov approximations for atom lasers
We discuss the use of the Born and Markov approximations in describing the
dynamics of an atom laser. In particular, we investigate the applicability of
the quantum optical Born-Markov master equation for describing output coupling.
We derive conditions based on the atomic reservoir, and atom dispersion
relations for when the Born-Markov approximations are valid and discuss
parameter regimes where these approximations fail in our atom laser model.
Differences between the standard optical laser model and the atom laser are due
to a combination of factors, including the parameter regimes in which a typical
atom laser would operate, the different reservoir state which is appropriate
for atoms, and the different dispersion relations between atoms and photons. We
present results based on an exact method in the regimes in which the
Born-Markov approximation fails. The exact solutions in some experimentally
relavent parameter regimes give non-exponential loss of atoms from a cavity.Comment: 10 pages, 3 figures. (2 new figues). Exact solutions have been
included in section II. Sections IV and V have been expanded. A new section
discussing the effects of gravity has been include
Stabilising entanglement by quantum jump-based feedback
We show that direct feedback based on quantum jump detection can be used to
generate entangled steady states. We present a strategy that is insensitive to
detection inefficiencies and robust against errors in the control Hamiltonian.
This feedback procedure is also shown to overcome spontaneous emission effects
by stabilising states with high degree of entanglement.Comment: 5 pages, 4 figure
Best interests, dementia and the Mental Capacity Act (2005)
The Mental Capacity Act (2005) is an impressive piece of
legislation that deserves serious ethical attention, but
much of the commentary on the Act has focussed on its
legal and practical implications rather than the underlying
ethical concepts. This paper examines the approach that
the Act takes to best interests. The Act does not provide
an account of the underlying concept of best interests.
Instead it lists factors that must be considered in
determining best interests, and the Code of Practice to
the Act states that this list is incomplete. This paper
argues that this general approach is correct, contrary to
some accounts of best interests. The checklist includes
items that are unhelpful. Furthermore, neither the Act nor
its Code of Practice provides sufficient guidance to carers
faced with difficult decisions concerning best interests.
This paper suggests ways in which the checklist can be
developed and discusses cases that could be used in an
updated Code of Practice
Generating controllable atom-light entanglement with a Raman atom laser system
We introduce a scheme for creating continuous variable entanglement between
an atomic beam and an optical field, by using squeezed light to outcouple atoms
from a BEC via a Raman transition. We model the full multimode dynamics of the
atom laser beam and the squeezed optical field, and show that with appropriate
two-photon detuning and two-photon Rabi frequency, the transmitted light is
entangled in amplitude and phase with the outcoupled atom laser beam. The
degree of entanglement is controllable via changes in the two-photon Rabi
frequency of the outcoupling process.Comment: 4 pages, 4 figure
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