575 research outputs found
Sensitivity of IceCube-DeepCore to neutralino dark matter in the MSSM-25
We analyse the sensitivity of IceCube-DeepCore to annihilation of neutralino
dark matter in the solar core, generated within a 25 parameter version of the
minimally supersymmetric standard model (MSSM-25). We explore the
25-dimensional parameter space using scanning methods based on importance
sampling and using DarkSUSY 5.0.6 to calculate observables. Our scans produced
a database of 6.02 million parameter space points with neutralino dark matter
consistent with the relic density implied by WMAP 7-year data, as well as with
accelerator searches. We performed a model exclusion analysis upon these points
using the expected capabilities of the IceCube-DeepCore Neutrino Telescope. We
show that IceCube-DeepCore will be sensitive to a number of models that are not
accessible to direct detection experiments such as SIMPLE, COUPP and XENON100,
indirect detection using Fermi-LAT observations of dwarf spheroidal galaxies,
nor to current LHC searches.Comment: 15 pages, 13 figures. V2: Additional comparisons are made to limits
from Fermi-LAT observations of dwarf spheroidal galaxies and to the 125 GeV
Higgs signal from the LHC. The spectral hardness section has been removed.
Matches version accepted for publication in JCAP. V3: Typos correcte
Structure retrieval at atomic resolution in the presence of multiple scattering of the electron probe
The projected electrostatic potential of a thick crystal is reconstructed at
atomic-resolution from experimental scanning transmission electron microscopy
data recorded using a new generation fast- readout electron camera. This
practical and deterministic inversion of the equations encapsulating multiple
scattering that were written down by Bethe in 1928 removes the restriction of
established methods to ultrathin ( {\AA}) samples. Instruments
already coming on-line can overcome the remaining resolution-limiting effects
in this method due to finite probe-forming aperture size, spatial incoherence
and residual lens aberrations.Comment: 6 pages, 3 figure
Potential benefits of an adaptive forward collision warning system
Forward collision warning (FCW) systems can reduce rear-end vehicle collisions. However, if the presentation of warnings is perceived as mistimed, trust in the system is diminished and drivers become less likely to respond appropriately. In this driving simulator investigation, 45 drivers experienced two FCW systems: a non-adaptive and an adaptive FCW that adjusted the timing of its alarms according to each individual driver’s reaction time. Whilst all drivers benefited in terms of improved safety from both FCW systems, non-aggressive drivers (low sensation seeking, long followers) did not display a preference to the adaptive FCW over its non-adaptive equivalent. Furthermore, there was little evidence to suggest that the non-aggressive drivers’ performance differed with either system. Benefits of the adaptive system were demonstrated for aggressive drivers (high sensation seeking, short followers). Even though both systems reduced their likelihood of a crash to a similar extent, the aggressive drivers rated each FCW more poorly than their non-aggressive contemporaries. However, this group, with their greater risk of involvement in rear-end collisions, reported a preference for the adaptive system as they found it less irritating and stress-inducing. Achieving greater acceptance and hence likely use of a real system is fundamental to good quality FCW design
Implementing a suicide risk management plan in general practice: the central role of practice nurses
Book Reviews
Book Review 1Book Title: Atlas of Microscopic Structures of Fur Skins Vol. 1Book Authors: Anton Blažej et al.Elsevier Amsterdam and SNTl, Prague, 1989. 378 pages.Book Review 2Book Title: Ornithology for AfricaBook Author: Gordon L. MacleanUniversity of Natal Press, 1990. 270 pages.Book Review 3Book Title: Biology of the Vespine WaspsBook Authors: Makoto Matsuura & Seiki YamaneSpringer-Verlag, Berlin, 1990. 323 pages, numerous figures, tables and photographs. ISBN 3-540-51900-9Book Review 4Book Title: Horns, Pronghorns, and AntlersBook Authors: Edited by G.A. Bubenik & A.B. BubenikSpringer-Verlag, New York. ISBN 0-387-97176-9. 562 pp.Book Review 5Book Title: Ecophysiology of Desert Arthropods and ReptilesBook Author: J.L. Cloudsley-ThompsonSpringer-Verlag, 1991. 203 pagesBook Review 6Book Title: Practical Taxonomic ComputingBook Author: Richard J. PankhurstCambridge University Press. 202 page
Solar wind density turbulence and solar flare electron transport from the Sun to the Earth
Solar flare accelerated electron beams propagating away from the Sun can
interact with the turbulent interplanetary media, producing plasma waves and
type III radio emission. These electron beams are detected near the Earth with
a double power-law energy spectrum. We simulate electron beam propagation from
the Sun to the Earth in the weak turbulent regime taking into account the
self-consistent generation of plasma waves and subsequent wave interaction with
density fluctuations from low frequency MHD turbulence. The rate at which
plasma waves are induced by an unstable electron beam is reduced by background
density fluctuations, most acutely when fluctuations have large amplitudes or
small wavelengths. This suppression of plasma waves alters the wave
distribution which changes the electron beam transport. Assuming a 5/3
Kolmogorov-type power density spectrum of fluctuations often observed near the
Earth, we investigate the corresponding energy spectrum of the electron beam
after it has propagated 1 AU. We find a direct correlation between the spectrum
of the double power-law below the break energy and the turbulent intensity of
the background plasma. For an initial spectral index of 3.5, we find a range of
spectra below the break energy between 1.6-2.1, with higher levels of
turbulence corresponding to higher spectral indices.Comment: 9 pages, 9 figures, to be published in Ap
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