11,794 research outputs found
Adding generic contextual capabilities to wearable computers
Context-awareness has an increasingly important role to play in the development of wearable computing systems. In order to better define this role we have identified four generic contextual capabilities: sensing, adaptation, resource discovery, and augmentation. A prototype application has been constructed to explore how some of these capabilities could be deployed in a wearable system designed to aid an ecologist's observations of giraffe in a Kenyan game reserve. However, despite the benefits of context-awareness demonstrated in this prototype, widespread innovation of these capabilities is currently stifled by the difficulty in obtaining the contextual data. To remedy this situation the Contextual Information Service (CIS) is introduced. Installed on the user's wearable computer, the CIS provides a common point of access for clients to obtain, manipulate and model contextual information independently of the underlying plethora of data formats and sensor interface mechanisms
THE GODFATHER DOCTRINE: A FOREIGN POLICY PARABLE, J.C. Hulsman and A.W. Mitchell, Princeton University Press, Princeton, 2009, 85 pages. ISBN 978-0-691-14147-3
The Godfather Doctrine is an expanded version of an essay published in The National Interest, a US popular journal largely focused on foreign policy issues. The book version is short and sweet, consisting of an introduction, the original article itself (with some modifications) and an epilogue outlining the responses to the original article and extending the analysis beyond its original Middle East focus. While 85 pages long, the book itself is small in size, and is easily read within an hour. The authors are both international relations and foreign policy consultants ...
Mussel eggs as indicators of mutagen exposure in coastal and estuarine environments
The aim of this study was to develop a short-term genotoxicity assay for monitoring the marine environment for mutagens. Based on the developing eggs and embryos of the marine mussel Mytilus edulis, an important pollution indicator species, the test employs the sensitive sister chromatid exchange (SCE) technique as its end-point, and exploits the potential of mussel eggs to accumulate mutagenic pollutants from the surrounding sea water. Mussel eggs take up to 6 months to develop while in the gonad, which provides scope for DNA damage to be accumulated over an extended time interval; chromosome damage is subsequently visualised as SCEs in 2-cell-stage embryos after these have been spawned in the laboratory. Methods which measure biological responses to pollutant exposure are able to integrate all the factors (internal and external) which contribute to the exposure. The new cytogenetic assay allows the effects of adult exposure to be interpreted in cells destined to become part of the next generation
Benchmarking Fast-to-Alfven Mode Conversion in a Cold MHD Plasma
Alfv\'en waves may be generated via mode conversion from fast
magneto-acoustic waves near their reflection level in the solar atmosphere,
with implications both for coronal oscillations and for active region
helio-seismology. In active regions this reflection typically occurs high
enough that the Alfv\'en speed greatly exceeds the sound speed , well
above the level where the fast and slow modes interact. In order to focus
on the fundamental characteristics of fast/Alfv\'en conversion, stripped of
unnecessary detail, it is therefore useful to freeze out the slow mode by
adopting the gravitationally stratified cold MHD model . This provides a
benchmark for fast-to-Alfv\'en mode conversion in more complex atmospheres.
Assuming a uniform inclined magnetic field and an exponential Alfv\'en speed
profile with density scale height , the Alfv\'en conversion coefficient
depends on three variables only; the dimensionless
transverse-to-the-stratification wavenumber , the magnetic field
inclination from the stratification direction , and the polarization
angle of the wavevector relative to the plane containing the
stratification and magnetic field directions. We present an extensive
exploration of mode conversion in this parameter space and conclude that
near-total conversion to outward-propagating Alfv\'en waves typically occurs
for small and large (--), though it is
absent entirely when is exactly zero (vertical field). For wavenumbers
of helioseismic interest, the conversion region is broad enough to encompass
the whole chromosphere.Comment: 14 pages plus supplementary tables. Astrophys J (accepted 25 May
2011). Two ancillary animations (animated gif) attache
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