25,681 research outputs found
The locality of the square-root method for improved staggered quarks
We study the effects of improvement on the locality of square-rooted
staggered Dirac operators in lattice QCD simulations. We find the localisation
lengths of the improved operators (FAT7TAD and ASQTAD) to be very similar to
that of the one-link operator studied by Bunk et al., being at least the
Compton wavelength of the lightest particle in the theory, even in the
continuum limit. We conclude that improvement has no effect. We discuss the
implications of this result for the locality of the nth-rooted fermion
determinant used to reduce the number of sea quark flavours, and for possible
staggered valence quark formulations
The effect of different solar simulators on the measurement of short-circuit current temperature coefficients
Gallium arsenide solar cells are considered for several high temperature missions in space. Both near-Sun and concentrator missions could involve cell temperatures on the order of 200 C. Performance measurements of cells at elevated temperatures are usually made using simulated sunlight and a matched reference cell. Due to the change in bandgap with increasing temperature at portions of the spectrum where considerable simulated irradiance is present, there are significant differences in measured short circuit current at elevated temperatures among different simulators. To illustrate this, both experimental and theoretical data are presented for gallium arsenide cells
Radiation performance of AlGaAs concentrator cells and expected performance of cascade structures
Aluminum gallium arsenide, GaAs, silicon and InGaAs cells have been irradiated with 1 MeV electrons and 37 MeV protons. These cells are candidates for individual cells in a cascade structure. Data is presented for both electron and proton irradiation studies for one sun and a concentration level of 100X AMO. Results of calculations on the radiation resistance of cascade cell structures based on the individual cell data are also presented. Both series connected and separately connected structures are investigated
Study protocol: Delayed intervention randomised controlled trial within the Medical Research Council (MRC) Framework to assess the effectiveness of a new palliative care service
Background: Palliative care has been proposed to help meet the needs of patients who suffer
progressive non-cancer conditions but there have been few evaluations of service development
initiatives. We report here a novel protocol for the evaluation of a new palliative care service in
this context.
Methods/Design: Using the MRC Framework for the Evaluation of Complex Interventions we
modelled a new palliative care and neurology service for patients severely affected by Multiple
Sclerosis (MS). We conducted qualitative interviews with patients, families and staff, plus a
literature review to model and pilot the service. Then we designed a delayed intervention
randomised controlled trial to test its effectiveness as part of phase II of the MRC framework.
Inclusion criteria for the trial were patients identified by referring clinicians as having unresolved
symptoms or psychological concerns. Referrers were advised to use a score of greater than 8 on
the Expanded Disability Scale was a benchmark. Consenting patients newly referred to the new
service were randomised to either receive the palliative care service immediately (fast-track) or
after a 12-week wait (standard best practice). Face to face interviews were conducted at baseline
(before intervention), and at 4–6, 10–12 (before intervention for the standard-practice group), 16–
18 and 22–24 weeks with patients and their carers using standard questionnaires to assess
symptoms, palliative care outcomes, function, service use and open comments. Ethics committee
approval was granted separately for the qualitative phase and then for the trial.
Discussion: We publish the protocol trial here, to allow methods to be reviewed in advance of
publication of the results. The MRC Framework for the Evaluation of Complex Interventions was
helpful in both the design of the service, methods for evaluation in convincing staff and the ethics
committee to accept the trial. The research will provide valuable information on the effects of
palliative care among non-cancer patients and a method to evaluate palliative care in this context
Estimating the Costs of MPCI Under the 1994 Crop Insurance Reform Act
The 1994 Crop Insurance Reform Act addressed two major problems of MPCI (multiple peril crop insurance): low participation and additional disaster assistance. In this study, total government costs for the FCIC (Federal Crop Insurance Corporation) and MPCI are estimated to be more than $2 billion, on average, from 1996 to 2003, with half of this amount being in the form of premium subsidies paid by the government
A synopsis of recent North American microtine rodents
http://deepblue.lib.umich.edu/bitstream/2027.42/56364/1/MP120.pd
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