53,562 research outputs found
The Dummies Guide' to Lottery Design.
This paper outlines the issues relevant to the operation of lottery games. We consider how such games should be designed, what a portfolio of games might look like, how the operator should be regulated, how spending on lottery games should be taxed, and what considerations are relevant to the use of the revenue from such games.LOTTERY ; GAMES ; MONEY ; TAXATION
Using Rasch analysis to form plausible health states amenable to valuation: the development of CORE-6D from CORE-OM in order to elicit preferences for common mental health problems
Purpose: To describe a new approach for deriving a preference-based index from a condition specific measure that uses Rasch analysis to develop health states.
Methods: CORE-OM is a 34-item instrument monitoring clinical outcomes of people with common mental health problems. CORE-OM is characterised by high correlation across its domains. Rasch analysis was used to reduce the number of items and response levels in order to produce a set of unidimensionally-behaving items, and to generate a credible set of health states corresponding to different levels of symptom severity using the Rasch item threshold map.
Results: The proposed methodology resulted in the development of CORE-6D, a 2-dimensional health state description system consisting of a unidimensionally-behaving 5-item emotional component and a physical symptom item. Inspection of the Rasch item threshold map of the emotional component helped identify a set of 11 plausible health states, which, combined with the physical symptom item levels, will be used for the valuation of the instrument, resulting in the development of a preference-based index.
Conclusions: This is a useful new approach to develop preference-based measures where the domains of a measure are characterised by high correlation. The CORE-6D preference-based index will enable calculation of Quality Adjusted Life Years in people with common mental health problems
Promoting green issues and sustainability in UK higher education libraries
Climate change affects us all. Individually and collectively, we must reduce our carbon footprint to protect the future of the planet. But how can higher education libraries contribute? In April of 2007, a request was made to SCONUL libraries – via LIS-SCONUL – for information on library green initiatives that they were taking forward. The responses highlighted that there is growing interest in the issue and that sustainability issues are beginning to be taken very seriously. This is partially driven by the greater awareness of the need to reduce carbon emissions throughout society. Specifically within higher education, it is also a result of encouragement by funding bodies, such as the Higher Education Funding Council for England (HEFCE) (see http://www.hefce. ac.uk/lgm/sustain/), through pressure from groups such as People and Planet and their ‘green league’ of higher education institutions (http:// peopleandplanet.org/gogreen/greenleague2007), and through rewards for excellence such as the Times Higher Education and Higher Education Academy Awards for an outstanding contribution by a higher education institution to sustainable development. Library staff are often active in wider institutional sustainability initiatives and can act as ‘champions’ for environmental issues and initiatives. Most of the libraries that responded to the request for information have aligned their green initiatives/ policies with those of their host organisation. Some libraries have participated in a wider institutional initiative to apply for the environmental management standard, ISO 14001. However, there are many specific ways that libraries can become more environmentally friendly and can make a difference
Drag coefficients for partially inflated flat circular parachutes
Free-body tests of flat circular parachutes and determination of aerodynamic drag coefficients during partial inflatio
Angle Dependence of Landau Level Spectrum in Twisted Bilayer Graphene
In the context of the low energy effective theory, the exact Landau level
spectrum of quasiparticles in twisted bilayer graphene with small twist angle
is analytically obtained by spheroidal eigenvalues. We analyze the dependence
of the Landau levels on the twist angle to find the points, where the two-fold
degeneracy for twist angles is lifted in the nonzero modes and below/above
which massive/massless fermion pictures become valid. In the perpendicular
magnetic field of 10\,T, the degeneracy is removed at %angles around 3 degrees for a few low levels, specifically,
for the first pair of nonzero levels and
for the next pair. Massive quasiparticle
appears at in 10\,T, %angles less
than 1.17 degrees. which match perfectly with the recent experimental results.
Since our analysis is applicable to the cases of arbitrary constant magnetic
fields, we make predictions for the same experiment performed in arbitrary
constant magnetic fields, e.g., for B=40\,T we get and the sequence of angles for the pairs of nonzero energy levels. The symmetry restoration
mechanism behind the massive/massless transition is conjectured to be a
tunneling (instanton) in momentum space.Comment: 8 pages, 7 figures, version to appear in PR
Origin of Anomalous Water Permeation through Graphene Oxide Membrane
Water inside the low dimensional carbon structures has been considered
seriously owing to fundamental interest in its flow and structures as well as
its practical impact. Recently, the anomalous perfect penetration of water
through graphene oxide membrane was demonstrated although the membrane was
impenetrable for other liquids and even gases. The unusual auxetic behavior of
graphene oxide in the presence of water was also reported. Here, based on
first-principles calculations, we establish atomistic models for hybrid systems
composed of water and graphene oxides revealing the anomalous water behavior
inside the stacked graphene oxides. We show that formation of hexagonal ice
bilayer in between the flakes as well as melting transition of ice at the edges
of flakes are crucial to realize the perfect water permeation across the whole
stacked structures. The distance between adjacent layers that can be controlled
either by oxygen reduction process or pressure is shown to determine the water
flow thus highlighting a unique water dynamics in randomly connected
two-dimensional spaces.Comment: 5 pages, 4 figures, to appear in Nano Letter
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