6,336 research outputs found
Border parasites: schistosomiasis control among Uganda's fisherfolk
Copyright @ 2012 Taylor & Francis. This article has been made publically available through the Brunel Open Access Publishing Fund.It is recognized that the control of schistosomisais in Uganda requires a focus on
fisherfolk. Large numbers suffer from this water-borne parasitic disease; notably along the shores of lakes Albert and Victoria and along the River Nile. Since 2004, a policy has been adopted of providing drugs, free of charge, to all those at risk. The strategy has been reported to be successful, but closer investigation reveals serious problems. This paper draws upon long-term research undertaken at three locations in northwestern and southeastern Uganda. It highlights consequences of not engaging with the day to day realities of fisherfolk
livelihoods; attributable, in part, to the fact that so many fisherfolk live and work in places located at the country’s international borders, and to a related
tendency to treat them as "feckless" and "ungovernable". Endeavours to roll out
treatment end up being haphazard, erratic and location-specific. In some places,
concerted efforts have been made to treat fisherfolk; but there is no effective
monitoring, and it is difficult to gauge what proportion have actually swallowed
the tablets. In other places, fisherfolk are, in practice, largely ignored, or are
actively harassed in ways that make treatment almost impossible. At all sites, the current reliance upon resident "community" drug distributors or staff based at static clinics and schools was found to be flawed.The Schistosomiasis Control Initiative, Imperial College, under the auspices of the Bill and Melinda Gates Foundation
Ultrafast control of inelastic tunneling in a double semiconductor quantum
In a semiconductor-based double quantum well (QW) coupled to a degree of
freedom with an internal dynamics, we demonstrate that the electronic motion is
controllable within femtoseconds by applying appropriately shaped
electromagnetic pulses. In particular, we consider a pulse-driven AlxGa1-xAs
based symmetric double QW coupled to uniformly distributed or localized
vibrational modes and present analytical results for the lowest two levels.
These predictions are assessed and generalized by full-fledged numerical
simulations showing that localization and time-stabilization of the driven
electron dynamics is indeed possible under the conditions identified here, even
with a simultaneous excitations of vibrational modes.Comment: to be published in Appl.Phys.Let
In situ aerosol measurements taken during the 2007 COPS field campaign at the Hornisgrinde ground site
Copyright @ 2011 Royal Meteorological Society.The Convective and Orographically-induced Precipitation Study (COPS) campaign was conducted during the summer of 2007. A suite of instruments housed at the top of the Hornisgrinde Mountain (1156 m) in the Black Forest region of south-west Germany provided datasets that allow an investigation into the physical, chemical and hygroscopic properties of the aerosol particles sampled during COPS. Organic mass loadings were found to dominate the aerosol composition for the majority of the project, exceeding 8 µg m−3 during a period of high pressure, high temperature, and low wind speed. The ratio of organic:sulphate sub-micron mass concentration exceeds 10:1 during the same time period. Back trajectories show air from this time-frame passing slowly over the local forest and not passing over any local anthropogenic sources. Occasional peaks in nitrate mass loadings were associated with changes in the typical wind direction from south-westerly to north-westerly where air had passed over the Stuttgart region. Size distribution data shows a dominant accumulation-mode when the measurement site was free from precipitation events. A sharp increase in ultrafine particle number concentration was seen during most days commencing around noon. The apparent growth of these particles is associated with an increase in organic mass loading, suggesting condensational growth. For the most part, with the exception of the high pressure period, the aerosol properties recorded during COPS were comparable to previous studies of continental aerosol properties.NER
Scalable many-core algorithms for tridiagonal solvers
We present a novel distributed memory Tridiagonal solver library, targeting large-scale systems based on modern multi-core and many-core processor architectures. The library uses methods based on both approximate and exact algorithms. Performance comparisons with the state-of-the-art, using both a large Cray EX system and a GPU cluster show the algorithmic trade-offs required at increasing machine scale to achieve good performance, particularly considering the advent of exascale systems
Thermal Neutron Flux Beyond the Bottom Shield Mockup
The tested mockup was composed of Be, Fe, Pb, and H/sub 2/O. Neutron doses at various positions beyond the shield are plotted. (D.E.B.
Thermodynamic basis of the concept of "recombination resistances"
The concept of "recombination resistance" introduced by Shockley and Read
(Phys. Rev. 87, 835 (1952)) is discussed within the framework of the
thermodynamics of irreversible processes ruled by the principle of the minimum
rate of entropy production. It is shown that the affinities of recombination
processes represent "voltages" in a thermodynamic Ohm-like law where the net
rates of recombinations represent the "currents". The quantities thus found
allow for the definition of the "dissipated power" which is to be related to
the rate of entropy production of the recombination processes dealt with.Comment: Submitted to Phys. Rev.
f_B with lattice NRQCD including O(1/m_Q^2) corrections
We calculate the heavy-light meson decay constant using lattice NRQCD action
for the heavy quark and Wilson quark action for the light quark over a wide
range in the heavy quark mass. Simulations are carried out on a 16^3 x 32
lattice with 120 quenched gauge configurations generated with the plaquette
action at beta=5.8. For the heavy quark part of the calculation, two sets of
lattice NRQCD action and current operator are employed. The first set includes
terms up to O(1/m_Q) both in the action and the current operator, and the
second set up to O(1/m_Q^2), where m_Q is the bare mass of the heavy quark.
Tree-level values with tadpole improvement are employed for the coefficients in
the expansion. We compare the results obtained from the two sets in detail and
find that the truncation error of higher order relativistic corrections for the
decay constant are adequately small around the mass of the b quark. We also
calculate the 1S hyperfine splitting of B meson, M_{B_s} - M_B and f_{B_s}/f_B
with both sets and find that the 1/m_Q^2 corrections are negligible. Remaining
systematic errors and the limitation of NRQCD theory are discussed.Comment: 27 pages, 15 figures, RevTex, psfig.sty require
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