23,415 research outputs found
GPs' views on new national smoking cessation guidelines
Objectives: To assess GPs? views on recently published national smoking cessation guidelines that form the foundation of the government?s smoking cessation strategy.Design: Postal survey of a random sample of GPs. GPs were asked to judge the appropriateness, effectiveness and practicability of key recommendations for primary care in recent national smoking cessation guidelines.Setting: General practice, England and Wales.Subjects: 236 GPs, effective response rate: 62%.Results: Only 16% of GPs accepted that all the recommendations in the guidelines were appropriate; 43% accepted that it was appropriate to check the smoking status of known smokers when they visit the surgery and only 30% thought it was practicable to advise smokers to stop at every opportunity. However, 77% of GPs thought that they should provide assistance for smokers wanting to stop; 74% believed that they should refer smokers to specialist services if appropriate and a similar proportion (77%) believed that it was appropriate to recommend nicotine replacement. Conclusions: Recommendations that involved the GP being proactive in monitoring smoking status and advising smokers to stop were not widely supported. There was greater acceptance that GPs should assist smokers wanting to stop, either by recommending NRT or providing counselling or referral. It appears that GPs do not widely support those recommendations that would produce the greatest public health gains
Voyager 1 imaging and IRIS observations of Jovian methane absorption and thermal emission: Implications for cloud structure
Images from three filters of the Voyager 1 wide angle camera are used to measure the continuum reflectivity and spectral gradient near 6000 A and the 6190 A band methane/continuum ratio for a variety of cloud features in Jupiter's atmosphere. The dark barge features in the North Equatorial Belt have anomalously strong positive continuum spectral gradients suggesting unique composition. Methane absorption is shown at unprecedented spatial scales for the Great Red Spot and its immediate environment, for a dark barge feature in the North Equatorial Belt, and for two hot spot and plume regions in the North Equatorial Belt. Methane absorption and five micrometer emission are correlated in the vicinity of the Great Red Spot but are anticorrelated in one of the plume hot spot regions. Methane absorption and simultaneous maps of five micrometer brightness temperature is quantitatively compared to realistic cloud structure models which include multiple scattering at five micrometer as well as in the visible. Variability in H2 quadrupole lines are also investigated
Assessing the effect of advertising expenditures upon sales: a Bayesian structural time series model
We propose a robust implementation of the Nerlove--Arrow model using a
Bayesian structural time series model to explain the relationship between
advertising expenditures of a country-wide fast-food franchise network with its
weekly sales. Thanks to the flexibility and modularity of the model, it is well
suited to generalization to other markets or situations. Its Bayesian nature
facilitates incorporating \emph{a priori} information (the manager's views),
which can be updated with relevant data. This aspect of the model will be used
to present a strategy of budget scheduling across time and channels.Comment: Published at Applied Stochastic Models in Business and Industry,
https://onlinelibrary.wiley.com/doi/full/10.1002/asmb.246
Degenerate states of narrow semiconductor rings in the presence of spin orbit coupling: Role of time-reversal and large gauge transformations
The electron Hamiltonian of narrow semiconductor rings with the Rashba and
Dresselhaus spin orbit terms is invariant under time-reversal operation
followed by a large gauge transformation. We find that all the eigenstates are
doubly degenerate when integer or half-integer quantum fluxes thread the
quantum ring. The wavefunctions of a degenerate pair are related to each other
by the symmetry operation. These results are valid even in the presence of a
disorder potential. When the Zeeman term is present only some of these
degenerate levels anticross
Imaging Transport Resonances in the Quantum Hall Effect
We use a scanning capacitance probe to image transport in the quantum Hall
system. Applying a DC bias voltage to the tip induces a ring-shaped
incompressible strip (IS) in the 2D electron system (2DES) that moves with the
tip. At certain tip positions, short-range disorder in the 2DES creates a
quantum dot island in the IS. These islands enable resonant tunneling across
the IS, enhancing its conductance by more than four orders of magnitude. The
images provide a quantitative measure of disorder and suggest resonant
tunneling as the primary mechanism for transport across ISs.Comment: 4 pages, 4 figures, submitted to PRL. For movies and additional
infomation, see http://electron.mit.edu/scanning/; Added scale bars to
images, revised discussion of figure 3, other minor change
Alignments of the Dominant Galaxies in Poor Clusters
We have examined the orientations of brightest cluster galaxies (BCGs) in
poor MKW and AWM clusters and find that, like their counterparts in richer
Abell clusters, poor cluster BCGs exhibit a strong propensity to be aligned
with the principal axes of their host clusters as well as the surrounding
distribution of nearby (< 20/h Mpc) Abell clusters. The processes responsible
for dominant galaxy alignments are therefore independent of cluster richness.
We argue that these alignments most likely arise from anisotropic infall of
material into clusters along large-scale filaments.Comment: 8 pages, 5 figure
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