4,660 research outputs found
What Have We Learned from Policy Transfer Research? Dolowitz and Marsh Revisited
Over the last decade, policy transfer has emerged as an important concept within public policy analysis, guiding both theoretical and empirical research spanning many venues and issue areas. Using Dolowitz and Marsh's 1996 stocktake as its starting point, this article reviews what has been learned by whom and for what purpose. It finds that the literature has evolved from its rather narrow, state-centred roots to cover many more actors and venues. While policy transfer still represents a niche topic for some researchers, an increasing number have successfully assimilated it into wider debates on topics such as globalisation, Europeanisation and policy innovation. This article assesses the concept's position in the overall âtool-kitâ of policy analysis, examines some possible future directions and reflects on their associated risks and opportunities
Symbiont-mediated fly survival is independent of defensive symbiont genotype in theDrosophila melanogaster-Spiroplasma-wasp interaction
Automation of large scale transient protein expression in mammalian cells
Traditional mammalian expression systems rely on the time-consuming generation of stable cell lines; this is difficult to accommodate within a modern structural biology pipeline. Transient transfections are a fast, cost-effective solution, but require skilled cell culture scientists, making man-power a limiting factor in a setting where numerous samples are processed in parallel. Here we report a strategy employing a customised CompacT SelecT cell culture robot allowing the large-scale expression of multiple protein constructs in a transient format. Successful protocols have been designed for automated transient transfection of human embryonic kidney (HEK) 293T and 293S GnTIâ» cells in various flask formats. Protein yields obtained by this method were similar to those produced manually, with the added benefit of reproducibility, regardless of user. Automation of cell maintenance and transient transfection allows the expression of high quality recombinant protein in a completely sterile environment with limited support from a cell culture scientist. The reduction in human input has the added benefit of enabling continuous cell maintenance and protein production, features of particular importance to structural biology laboratories, which typically use large quantities of pure recombinant proteins, and often require rapid characterisation of a series of modified constructs. This automated method for large scale transient transfection is now offered as a Europe-wide service via the P-cube initiative
Evidence for strategies that improve recruitment and retention of adults aged 65 years and over in randomised trials and observational studies: a systematic review
Background: adults aged â„65 years are often excluded from health research studies. Lack of representation reduces generalisability of treatments for this age group. Objective: to evaluate the effectiveness of strategies that improve recruitment and retention of adults aged â„65 in observational studies and randomised controlled trials (RCTs). Methods: searches conducted in 10 databases for RCTs of recruitment and retention strategies in RCTs or observational studies. Two reviewers screened abstracts and full-text articles for eligibility and extracted data. Studies without separate data for adults aged â„65 were discarded. Risk of bias assessed using the Cochrane Risk of Bias tool. Results were synthesised narratively. Results: thirty-two studies were included in the review (n = 75,444). Twelve studies had low risk of bias, of which 10 had successful strategies including: Opt-out versus opt-in increased recruitment (13.6% (n = 261)-18.7% (n = 36) difference; two studies); Advance notification increased retention (1.6% difference, OR 1.45; 95% CI 1.01, 2.10, one study (n = 2,686); 9.1% difference at 4 months, 1.44; 1.08, 1.92, one study (n = 753)); Hand-delivered versus postal surveys increased response (25.1% difference; X2 = 11.40, P < 0.01; one study (n = 139)); Open randomised design versus blinded RCT increased recruitment (1.56; 1.05, 2.33) and retention (13.9% difference; 3.1%, 24.6%) in one study (n = 538). Risk of bias was high/unclear for studies in which incentives or shorter length questionnaires increased response. Discussion: in low risk of bias studies, few of the strategies that improved participation in older adults had been tested in â„1 study. Opt-out and advance notification strategies improved recruitment and retention, respectively, although an opt-out approach may have ethical limitations. Evidence from single studies limits the generalisability of other strategies
Diffusion Monte Carlo calculations for the ground states of atoms and ions in neutron star magnetic fields
The diffusion quantum Monte Carlo method is extended to solve the old
theoretical physics problem of many-electron atoms and ions in intense magnetic
fields. The feature of our approach is the use of adiabatic approximation wave
functions augmented by a Jastrow factor as guiding functions to initialize the
quantum Monte Carlo prodecure. We calcula te the ground state energies of atoms
and ions with nuclear charges from Z= 2, 3, 4, ..., 26 for magnetic field
strengths relevant for neutron stars.Comment: 6 pages, 1 figure, proceedings of the "9th International Conference
on Path Integrals - New Trends and Perspectives", Max-Planck-Institut fur
Physik komplexer Systeme, Dresden, Germany, September 23 - 28, 2007, to be
published as a book by World Scientific, Singapore (2008
A retrospective analysis of the microbiology of diabetic foot infections at a Scottish tertiary hospital
Atomic calculation for the atmospheres of strongly-magnetized neutron stars
Complete modeling of radiative transfer in neutron star atmospheres is in
progress, taking into account the anisotropy induced by magnetic fields,
non-ideal effects and general relativity. As part of our modeling, we present a
novel atomic calculation method producing an extensive atomic data set
including energy values and oscillator strengths in the so-called Landau regime
( G). Conventional atmosphere models for B=0 are not
applicable to typical field strengths of cooling neutron stars ( G), since an atom no longer keeps its spherical shape. The
elemental composition and the configuration of the magnetic field in the
atmosphere are presently unknown, so that atomic data must be produced for
ground and excited states of several ions as a function of magnetic field. To
accomplish this efficiently, we minimized the iterations in the Hartree
equation and treated exchange terms and higher Landau states by perturbation
methods. This method has the effect of reducing the computation time
significantly. Inclusion of higher Landau states gives us much more accurate
data for inner orbitals unlike other methods based on the adiabatic
approximation. While existing atomic data in the Landau regime are available
only for low atoms, our method can be used in elements up to Fe with
sufficient accuracy to be of use for spectroscopic missions such as {\it
Chandra}, {\it XMM-Newton} and next-generation X-ray telescopes.Comment: 19 pages, AASTeX, 4 figures, accepted for publication in Ap
Musculoskeletal foot problems in primary care: what influences older people to consult?
Objective. To estimate the incidence of, and factors associated with, consultation for musculoskeletal foot problems in primary care
Electric dipole moments and disalignment of interstellar dust grains
The degree to which interstellar grains align with respect to the
interstellar magnetic field depends on disaligning as well as aligning
mechanisms. For decades, it was assumed that disalignment was due primarily to
the random angular impulses a grain receives when colliding with gas-phase
atoms. Recently, a new disalignment mechanism has been considered, which may be
very potent for a grain that has a time-varying electric dipole moment and
drifts across the magnetic field. We provide quantitative estimates of the
disalignment times for silicate grains with size > approximately 0.1 micron.
These appear to be shorter than the time-scale for alignment by radiative
torques, unless the grains contain superparamagnetic inclusions.Comment: 12 pages, 9 figures, submitted to MNRA
The ground state of the carbon atom in strong magnetic fields
The ground and a few excited states of the carbon atom in external uniform
magnetic fields are calculated by means of our 2D mesh Hartree-Fock method for
field strengths ranging from zero up to 2.35 10^9 T. With increasing field
strength the ground state undergoes six transitions involving seven different
electronic configurations which belong to three groups with different spin
projections S_z=-1,-2,-3. For weak fields the ground state configuration arises
from the field-free 1s^2 2s^2 2p_0 2p_{-1}, S_z=-1 configuration. With
increasing field strength the ground state involves the four S_z=-2
configurations 1s^22s2p_0 2p_{-1}2p_{+1}, 1s^22s2p_0 2p_{-1}3d_{-2}, 1s^22p_0
2p_{-1}3d_{-2}4f_{-3} and 1s^22p_{-1}3d_{-2}4f_{-3}5g_{-4}, followed by the two
fully spin polarized S_z=-3 configurations 1s2p_02p_{-1}3d_{-2}4f_{-3}5g_{-4}
and 1s2p_{-1}3d_{-2}4f_{-3}5g_{-4}6h_{-5}. The last configuration forms the
ground state of the carbon atom in the high field regime \gamma>18.664. The
above series of ground state configurations is extracted from the results of
numerical calculations for more than twenty electronic configurations selected
due to some general energetical arguments.Comment: 6 figures,acc. Phys.Rev.
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