1,982 research outputs found
Chalk streams and grazing mute swans
The evidence shows that swan grazing can reduce plant abundance, prevent flowering, reduce water depth and reduce fishery value. However, these effects seem to be limited to a small number of sites on larger chalk streams. The results of attempted management have been disappointing, and we currently have no simple effective means of preventing grazing damage. However, our understanding of the effects of swans on the chalk stream ecosystem has been growing rapidly, which gives us hope for future solutions. In particular, combining strategies which improve river condition and move swans away from sensitive areas could offer a way of managing grazing effects
Challenges in the management of HIV-infected malnourished children in Sub-Saharan Africa
Infection with HIV, and oftentimes coinfection with TB, complicates the care of severely malnourished children in sub-Saharan Africa. These superimposed infections challenge clinicians faced with a population of malnourished children for whose care evidence-based guidelines have not kept up. Even as the care of HIV-uninfected malnourished children has improved dramatically with the advent of community-based care and even as there are hopeful signs that the HIV epidemic may be stabilizing or ameliorating, significant gaps remain in the care of malnourished children with HIV. Here we summarize what is currently known, what remains unknown, and what remains challenging about how to treat severely malnourished children with HIV and TB.Publisher PDFPeer reviewe
Donor–NGO relations: the dynamics of European Community development co-operation policy
Shifts in development theory turned attention to the role Non-Governmental
Organisations (NGOs) could play in donor development policy. The heightened
interest in NGOs was accompanied by an increased availability of funds and presaged
a significant growth in the size of the NGO sector. This expanded role had
repercussions on both their internal organisation and their relations with other players
in the aid arena. However, in the 1990s, the financial market for development cooperation
became more competitive due to the changes in the former communist
countries and the embrace of neo-liberal principles. Consequently, NGOs were
criticised for their lack of professionalism and poor accountability, and found
themselves subject to donor conditionality and the assimilation of the language,
values and systems of donors. [Continues.
A Dark Matter Hurricane: Measuring the S1 Stream with Dark Matter Detectors
The recently discovered S1 stream passes through the Solar neighbourhood on a
low inclination, counter-rotating orbit. The progenitor of S1 is a dwarf galaxy
with a total mass comparable to the present-day Fornax dwarf spheroidal, so the
stream is expected to have a significant DM component. We compute the effects
of the S1 stream on WIMP and axion detectors as a function of the density of
its unmeasured dark component. In WIMP detectors the S1 stream supplies more
high energy nuclear recoils so will marginally improve DM detection prospects.
We find that even if S1 comprises less than 10% of the local density, multi-ton
xenon WIMP detectors can distinguish the S1 stream from the bulk halo in the
relatively narrow mass range between 5 and 25 GeV. In directional WIMP
detectors such as CYGNUS, S1 increases DM detection prospects more
substantially since it enhances the anisotropy of the WIMP signal. Finally, we
show that axion haloscopes possess by far the greatest potential sensitivity to
the S1 stream. Once the axion mass has been discovered, the distinctive
velocity distribution of S1 can easily be extracted from the axion power
spectrum.Comment: 21 pages, 11 figure
Respiratory challenge MRI: practical aspects
Respiratory challenge MRI is the modification of arterial oxygen (PaO2) and/or carbon dioxide (PaCO2) concentration to induce a change in cerebral function or metabolism which is then measured by MRI. Alterations in arterial gas concentrations can lead to profound changes in cerebral haemodynamics which can be studied using a variety of MRI sequences. Whilst such experiments may provide a wealth of information, conducting them can be complex and challenging. In this paper we review the rationale for respiratory challenge MRI including the effects of oxygen and carbon dioxide on the cerebral circulation. We also discuss the planning, equipment, monitoring and techniques that have been used to undertake these experiments. We finally propose some recommendations in this evolving area for conducting these experiments to enhance data quality and comparison between techniques
Developing a gamified peer-reviewed bug bounty programme
Bug bounty processes have remained broadly unchanged since their inception. Existing literature recognises that current methods generate intensive resource demands, impacting upon programme effectiveness. This paper proposes a novel implementation which aims to alleviate resource demands and mitigate inherent issues through gamification. This incorporates the use of additional crowdsourcing of vulnerability verification and reproduction by peers, allowing the client organisation to reduce overheads at the cost of rewarding participants. The system has the potential to be used in Higher Education Institutions which typically face resource and budget constraints
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