1,632 research outputs found
Applying economic evaluation to public health interventions: The case of interventions to promote physical activity
Copyright @ 2012 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.BACKGROUND: This paper explores the application of alternative approaches to economic evaluation of public health interventions, using a worked example of exercise referral schemes (ERSs). METHODS: Cost-utility (CUA) and cost-consequence analyses (CCA) were used to assess the cost-effectiveness of ERSs. For the CUA, evidence was synthesized using a decision analytic model that adopts a lifetime horizon and NHS/Personal Social Services perspective. Outcomes were expressed as incremental cost per quality-adjusted life-year (QALY). CCA was conducted from a partial-societal perspective, including health and non-healthcare costs and benefits. Outcomes were reported in natural units, such as cases of strokes or CHD avoided. RESULTS: Compared with usual care, the incremental cost per QALY of ERS is £20 876. Based on a cohort of 100 000 individuals, CCA estimates cost of ERS at £22 million to the healthcare provider and £12 million to participants. The benefits of ERS include additional 3900 people becoming physically active, 51 cases of CHD avoided, 16 cases of stroke avoided, 86 cases of diabetes avoided and a gain of ∼800 QALYs. CONCLUSIONS: CCA might provide greater transparency than CUA in reporting the outcomes of public health interventions and have greater resonance with stakeholders involved in commissioning these interventions.This work was supported by the NIHR Health Technology Assessment programme (project number 08/72/01). This article is made available through the Brunel Open Access Publishing Fund
Hysterectomy, endometrial destruction, and levonorgestrel releasing intrauterine system (Mirena) for heavy menstrual bleeding : systematic review and meta-analysis of data from individual patients
Peer reviewedPublisher PD
S and D Wave Mixing in High Superconductors
For a tight binding model with nearest neighbour attraction and a small
orthorhombic distortion, we find a phase diagram for the gap at zero
temperature which includes three distinct regions as a function of filling. In
the first, the gap is a mixture of mainly -wave with a smaller extended
-wave part. This is followed by a region in which there is a rapid increase
in the -wave part accompanied by a rapid increase in relative phase between
and from 0 to . Finally, there is a region of dominant with a
mixture of and zero phase. In the mixed region with a finite phase, the
-wave part of the gap can show a sudden increase with decreasing temperature
accompanied with a rapid increase in phase which shows many of the
characteristics measured in the angular resolved photoemission experiments of
Ma {\em et al.} in Comment: 12 pages, RevTeX 3.0, 3 PostScript figures uuencoded and compresse
TrES-2: The First Transiting Planet in the Kepler Field
We announce the discovery of the second transiting hot Jupiter discovered by
the Trans-atlantic Exoplanet Survey. The planet, which we dub TrES-2, orbits
the nearby star GSC 03549-02811 every 2.47063 days. From high-resolution
spectra, we determine that the star has T_eff = 5960 +/- 100 K and log(g) = 4.4
+/- 0.2, implying a spectral type of G0V and a mass of 1.08 +0.11/-0.05 M_sun.
High-precision radial-velocity measurements confirm a sinusoidal variation with
the period and phase predicted by the photometry, and rule out the presence of
line-bisector variations that would indicate that the spectroscopic orbit is
spurious. We estimate a planetary mass of 1.28 +0.09/-0.04 M_Jup. We model B,
r, R, and I photometric timeseries of the 1.4%-deep transits and find a
planetary radius of 1.24 +0.09/-0.06 R_Jup. This planet lies within the field
of view of the NASA Kepler mission, ensuring that hundreds of upcoming transits
will be monitored with exquisite precision and permitting a host of
unprecedented investigations.Comment: Accepted for publication in ApJL. 15 pages, 2 figure
TrES-3: A Nearby, Massive, Transiting Hot Jupiter in a 31-Hour Orbit
We describe the discovery of a massive transiting hot Jupiter with a very
short orbital period (1.30619 d), which we name TrES-3. From spectroscopy of
the host star GSC 03089-00929, we measure T_eff = 5720 +- 150 K, logg=4.6 +-
0.3, and vsini < 2 km/s, and derive a stellar mass of 0.90 +- 0.15 M_sun. We
estimate a planetary mass of 1.92 +- 0.23 M_Jup, based on the sinusoidal
variation of our high-precision radial velocity measurements. This variation
has a period and phase consistent with our transit photometry. Our spectra show
no evidence of line bisector variations that would indicate a blended eclipsing
binary star. From detailed modeling of our B and z photometry of the 2.5%-deep
transits, we determine a stellar radius 0.802 +- 0.046 R_sun and a planetary
radius 1.295 +- 0.081 R_Jup. TrES-3 has one of the shortest orbital periods of
the known transiting exoplanets, facilitating studies of orbital decay and mass
loss due to evaporation, and making it an excellent target for future studies
of infrared emission and reflected starlight.Comment: v1. 14 pages, 2 figures, 3 tables. Submitted to ApJL 27 April 2007.
Accepted for publication in ApJL 14 May 200
A New Spectroscopic and Photometric Analysis of the Transiting Planet Systems TrES-3 and TrES-4
We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution spectra yields [Fe/H] = –0.19 ± 0.08, T_(eff) = 5650 ± 75 K, and log g = 4.4 ± 0.1 for TrES-3, and [Fe/H] = +0.14 ± 0.09, T_(eff) = 6200 ± 75 K, and log g = 4.0 ± 0.1 for TrES-4. The accuracy of the effective temperatures is supported by a number of independent consistency checks. The spectroscopic orbital solution for TrES-3 is improved with our new radial velocity measurements of that system, as are the light-curve parameters for both systems based on newly acquired photometry for TrES-3 and a reanalysis of existing photometry for TrES-4. We have redetermined the stellar parameters taking advantage of the strong constraint provided by the light curves in the form of the normalized separation a/R_* (related to the stellar density) in conjunction with our new temperatures and metallicities. The masses and radii we derive are M_* = 0.928^(+0.028)_(–0.048) M_⊙, R_* = 0.829^(+0.015)_(–0.022) R_⊙, and M_* = 1.404^(+0.066)_(–0.134) M_⊙, R_* = 1.846^(+0.096)_(–0.087) R_⊙ for TrES-3 and TrES-4, respectively. With these revised stellar parameters, we obtain improved values for the planetary masses and radii. We find M_p = 1.910^(+0.075)_(–0.080) M_(Jup), R_p = 1.336^(+0.031)_(–0.036) R_(Jup) for TrES-3, and M_p = 0.925 ± 0.082 M_(Jup), R_p = 1.783^(+0.093)_(–0.086) R_(Jup) for TrES-4. We confirm TrES-4 as the planet with the largest radius among the currently known transiting hot Jupiters
On the Inference of Thermal Inversions in Hot Jupiter Atmospheres
Several studies in the recent past have inferred the existence of thermal
inversions in some transiting hot Jupiter atmospheres. Given the limited data
available, the inference of a thermal inversion depends critically on the
chemical composition assumed for the atmosphere. In this study, we explore the
degeneracies between thermal inversions and molecular abundances in four highly
irradiated hot Jupiter atmospheres, day-side observations of which were
previously reported to be consistent with thermal inversions based on Spitzer
photometry. The four systems are: HD 209458b, HAT-P-7b, TrES-4, and TrES-2. For
each system, we explore the model parameter space with ~ 10^6 models using a
Markov chain Monte Carlo routine. Our results primarily suggest that a thorough
exploration of the model parameter space is necessary to identify thermal
inversions in hot Jupiter atmospheres. We find that existing observations of
TrES-4 and TrES-2 can both be fit very precisely with models with and without
thermal inversions, and with a wide range in chemical composition. On the other
hand, observations of HD 209458b and HAT-P-7b are better fit with thermal
inversions than without, as has been reported before. We do not see a
correlation between irradiation levels and thermal inversions, given current
data. Before JWST becomes available, near-IR observations from ground and with
HST, along with existing Spitzer observations, can potentially resolve thermal
inversions in some systems.Comment: 16 pages in emulate ApJ format, 6 figures, 3 tables (Accepted in ApJ
A New Spectroscopic and Photometric Analysis of the Transiting Planet Systems TrES-3 and TrES-4
We report new spectroscopic and photometric observations of the parent stars
of the recently discovered transiting planets TrES-3 and TrES-4. A detailed
abundance analysis based on high-resolution spectra yields [Fe/H] , K, and for TrES-3,
and [Fe/H] , K, and for TrES-4. The accuracy of the effective temperatures is supported
by a number of independent consistency checks. The spectroscopic orbital
solution for TrES-3 is improved with our new radial-velocity measurements of
that system, as are the light-curve parameters for both systems based on newly
acquired photometry for TrES-3 and a reanalysis of existing photometry for
TrES-4. We have redetermined the stellar parameters taking advantage of the
strong constraint provided by the light curves in the form of the normalized
separation (related to the stellar density) in conjunction with our
new temperatures and metallicities. The masses and radii we derive are
M_\star=0.928_{-0.048}^{+0.028} M_{\sun},R_\star = 0.829_{-0.022}^{+0.015}
R_{\sun}, and M_\star = 1.404_{-0.134}^{+0.066} M_{\sun},
R_\star=1.846_{-0.087}^{+0.096} R_{\sun} for TrES-3 and TrES-4, respectively.
With these revised stellar parameters we obtain improved values for the
planetary masses and radii. We find , for TrES-3, and
, for TrES-4. We confirm TrES-4 as the planet with the largest
radius among the currently known transiting hot Jupiters.Comment: 42 pages, 10 tables, 8 figures. Accepted for publication in the
Astrophysical Journa
Electronic states on a twin boundary of a d-wave superconductor
We show that an induced -wave harmonic in the superconducting gap of an
orthorhombic superconductor strongly affects the excitation
spectrum near a twinning plane. In particular, it yields bound states of zero
energy with areal density proportional to the relative weight of the -wave
component. An unusual scattering process responsible for the thermal
conductivity across the twin boundary at low temperatures is also identified.Comment: 4 pages, ReVTEX, 2 PS-figure
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