2,385 research outputs found
Sky localization of complete inspiral-merger-ringdown signals for nonspinning massive black hole binaries
We investigate the capability of LISA to measure the sky position of
equal-mass, nonspinning black hole binaries, combining for the first time the
entire inspiral-merger-ringdown signal, the effect of the LISA orbits, and the
complete three-channel LISA response. We consider an ensemble of systems near
the peak of LISA's sensitivity band, with total rest mass of 2\times10^6
M\odot, a redshift of z = 1, and randomly chosen orientations and sky
positions. We find median sky localization errors of approximately \sim3
arcminutes. This is comparable to the field of view of powerful electromagnetic
telescopes, such as the James Webb Space Telescope, that could be used to
search for electromagnetic signals associated with merging massive black holes.
We investigate the way in which parameter errors decrease with measurement
time, focusing specifically on the additional information provided during the
merger-ringdown segment of the signal. We find that this information improves
all parameter estimates directly, rather than through diminishing correlations
with any subset of well- determined parameters. Although we have employed the
baseline LISA design for this study, many of our conclusions regarding the
information provided by mergers will be applicable to alternative mission
designs as well.Comment: 9 pages, 5 figures, submitted to Phys. Rev.
Sky Localization of Complete Inspiral-Merger-Ringdown Signals for Nonspinning Black Hole Binaries with LISA
We investigate the capability of LISA to measure the sky position of equal-mass, nonspinning black hole binaries, including for the first time the entire inspiral-merger-ringdown signal, the effect of the LISA orbits, and the complete three-channel LISA response. For an ensemble of systems near the peak of LISA's sensitivity band, with total rest mass of 2 x l0(exp 6) Stellar Mass at a redshift of z = 1 with random orientations and sky positions, we find median sky localization errors of approximately approx. 3 arcminutes. This is comparable to the field of view of powerful electromagnetic telescopes, such as the James Webb Space Telescope, that could be used to search for electromagnetic signals associated with merging black holes. We investigate the way in which parameter errors decrease with measurement time, focusing specifically on the additional information provided during the merger-ringdown segment of the signal. We find that this information improves all parameter estimates directly, rather than through diminishing correlations with any subset of well-determined parameters
881-5 Comparison of modified acoustic quantification with echocardiographic contrast and radionuclide ventriculography for evaluation of left ventricular ejection fraction
S-wave Kpi scattering in chiral perturbation theory with resonances
We present a detailed analysis of S-wave Kpi scattering up to 2 GeV, making
use of the resonance chiral Lagrangian predictions together with a suitable
unitarisation method. Our approach incorporates known theoretical constraints
at low and high energies. The present experimental status, with partly
conflicting data from different experiments, is discussed. Our analysis allows
to resolve some experimental ambiguities, but better data are needed in order
to determine the cross-section in the higher-energy range. Our best fits are
used to determine the masses and widths of the relevant scalar resonances in
this energy region.Comment: 40 pages, 6 figure
Accuracy of three-dimensional echocardiographic measurements of mitral valve orifice area using transthoracic free-hand scanning
Four-dimensional pure compact U(1) gauge theory on a spherical lattice
We investigate the confinement-Coulomb phase transition in the
four-dimensional (4D) pure compact U(1) gauge theory on spherical lattices. The
action contains the Wilson coupling beta and the double charge coupling gamma.
The lattice is obtained from the 4D surface of the 5D cubic lattice by its
radial projection onto a 4D sphere, and made homogeneous by means of
appropriate weight factors for individual plaquette contributions to the
action. On such lattices the two-state signal, impeding the studies of this
theory on toroidal lattices, is absent for gamma le 0. Furthermore, here a
consistent finite-size scaling behavior of several bulk observables is found,
with the correlation length exponent nu in the range nu = 0.35 - 40. These
observables include Fisher zeros, specific-heat and cumulant extrema as well as
pseudocritical values of beta at fixed gamma. The most reliable determination
of nu by means of the Fisher zeros gives nu = 0.365(8). The phase transition at
gamma le 0 is thus very probably of 2nd order and belongs to the universality
class of a non-Gaussian fixed point.Comment: 40 pages, LaTeX, 12 figure
Optimization of care for patients with hereditary angioedema living in rural areas
BACKGROUND: People living in rural areas of the United States experience greater health inequality than individuals residing in urban or suburban locations and encounter several barriers to obtaining optimal health care. Health disparities are compounded for patients with rare diseases such as hereditary angioedema (HAE), an autosomal dominant genetic disorder characterized by recurrent, severe abdominal pain and life-threatening oropharyngeal or laryngeal swelling.
OBJECTIVE: To explore the challenges of managing patients with HAE in rural areas and suggest possible improvements for optimizing care.
DATA SOURCES: PubMed was searched for articles on patient care management, treatment challenges, rural health, and HAE.
STUDY SELECTIONS: Relevant articles were selected and reviewed.
RESULTS: Challenges in managing HAE in the rural setting were identified, including obtaining a diagnosis of HAE, easy access to a physician with expertise in HAE, continuity of care, availability of telemedicine services, access to approved HAE therapies, patient education, and economic barriers to treatment. Ways to improve HAE patient care in rural areas include health care provider recognition of the patient with undiagnosed HAE, development of individualized management plans, expansion of telemedicine, effective care at the local level, appropriate access to HAE medication, and increased awareness of patient support and advocacy groups.
CONCLUSION: For patients with HAE living in rural areas, optimal care is complicated by health disparities. Given the scarcity with which these topics have been covered in the literature to date, it is intended that this article will serve as the impetus for a range of further initiatives focused on improving access to care
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Looking into the future, what do we see?
This series of short communications introduces and celebrates the occasion of World Nutrition Rio2012, and looks ahead. There will be another series published next month in our May issue, which will be on-line early, at 0001 GMT on Thursday 26 April, the day before Rio2012 begins.
The questions and answers: Our contributors, this month and next month, have been asked to write within a standard framework, based on their knowledge and experience, in a style comparable with those of the news and comment sections of journals concerned with public health. Their contributions are judgements, as any policy statements are and must be. The first question is about Rio2012 itself. The second question is addressed to young colleagues. All the questions are designed to look forward and to advise, warn and encourage.
What do I hope Rio2012 will achieve?
My advice to a young public health nutritionist
When I am optimistic, what is my vision?
When I am pessimistic, what do I foresee?
My most highly recommended writer
One choice of my own publication
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