113 research outputs found
Hypertension prevalence and awareness in older Irish adults: Evidence from the Irish Longitudinal Study on Ageing (TILDA)
Introduction: Hypertension prevalence is increasing worldwide: population ageing and an increase in the prevalence of obesity are contributing to this rise. Hypertension is a major modifiable risk factor for stroke, coronary heart disease, end stage renal disease and has been associated with cognitive impairment. The aim of this study is to determine the prevalence of hypertension and to identify determinants of awareness of hypertension in older Irish adults.
Methods: The Irish Longitudinal Study on Ageing (TILDA) is a population based prospective cohort study representative of community living adults. Each member of the Irish population aged 50 years and older had an equal probability of participation in the study. Face to face interviews and objective health assessments were conducted between Oct 2009 and July 2011. Descriptive statistics and logistic regression analysis were used to calculate prevalence and determinants of awareness of hypertension. Survey weights were applied to the estimates to adjust for selection and non-response bias in the survey.
Results: The household response rate was 62%. Of the 8,175 respondents who took part in the study 5857 (71.6%) completed a comprehensive health assessment including blood pressure measurement. Hypertension was defined as a mean systolic blood pressure (SBP) â„140mmHg and/or a mean diastolic blood pressure (DBP) â„90mmHg and/or currently taking antihypertensive medications. The overall prevalence of hypertension was 64% (95% CI 62-65%) in those aged 50 years and older. Hypertension prevalence was higher in men than in women (69% vs 59%, p<.007) and prevalence increased with age to 87% (95% CI 84-89%) in those aged 75 years and older. Of those classified as hypertensive 55% (95% CI 53-57%) self-reported a previous doctorâs diagnosis of hypertension. Strong determinants of awareness included older age, female sex, overweight and obesity.
Conclusions: This study documents a high prevalence of hypertension in adults aged 50 years and older in Ireland and identifies a low level of awareness of hypertension in this group. Raising awareness of hypertension is a major public health challenge. These findings provide reliable information which can contribute to practice and policy aimed at decreasing the prevalence of hypertension
A comparative high-resolution study of predissociation linewidths in the Schumann-Runge bands of O2
Results are presented of a comparative study in which three distinct high-resolution experimental techniques (vacuum-ultraviolet laser spectroscopy, laser-induced fluorescence spectroscopy and vacuum-ultraviolet Fourier-transform spectroscopy) were used to study predissociation in the Schumann-Runge bands of O2 Bâ3ÎŁâŻu(vâČ)âXâ3ÎŁâŻg(vâł) with vâČ=13 and 14. Our measurements are the first to be performed at high resolution for these levels and represent a significant advance on previous knowledge, characterizing completely the fine-structure and rotation dependencies of the Bâ3ÎŁâŻu(v=13âandâ14)-state predissociation for the first time. The measured fine-structurespecific linewidths will result in significant improvements in the parameterization of models describing predissociation of the B-state and will have an impact on the development of realistic photochemical models of the terrestrial atmosphere. Good agreement was found between linewidths measured using vacuum-ultraviolet laser spectroscopy and laser-induced fluorescence spectroscopy, but unexpected difficulties arose in determining quantitative linewidths using vacuum-ultraviolet Fourier-transform spectroscopy. For each experimental technique, the instrumental resolution had to be carefully controlled and monitored in order to ensure reliable interpretation of the measured spectra.The collaborative aspects of this research have been partially supported by reciprocal U.S.-Australian Cooperative
Research Grants provided by the National Science Foundation ~U.S.! and the Department of Industry, Technology and
Commerce ~Australia!. The measurements at SRI International were partially supported by grants from the Atmospheric Sciences Division of NSF and from the Stratospheric
Chemistry Division of NASA. The measurements at the Photon Factory were supported in part by a NSF Division of
Atmospheric Sciences Grant No. ATM-91-16552 to Harvard
College Observatory, and by the NASA Upper Atmospheric
Research Program under Grant No. NAG5-484 to the Smithsonian Astrophysical Observatory. We also acknowledge the
support of the Paul Instrument Fund of the Royal Society for
the development of the VUV-FT spectrometer. The FTS
measurements were made with the approval of the Photon
Factory Advisory Committee ~94G367!. K.Y. thanks the Japan Society for the Promotion of Science for support
Kaon-Nucleon Scattering Amplitudes and Z-Enhancements from Quark Born Diagrams
We derive closed form kaon-nucleon scattering amplitudes using the ``quark
Born diagram" formalism, which describes the scattering as a single interaction
(here the OGE spin-spin term) followed by quark line rearrangement. The low
energy I=0 and I=1 S-wave KN phase shifts are in reasonably good agreement with
experiment given conventional quark model parameters. For Gev
however the I=1 elastic phase shift is larger than predicted by Gaussian
wavefunctions, and we suggest possible reasons for this discrepancy. Equivalent
low energy KN potentials for S-wave scattering are also derived. Finally we
consider OGE forces in the related channels K, KN and K,
and determine which have attractive interactions and might therefore exhibit
strong threshold enhancements or ``Z-molecule" meson-baryon bound states.
We find that the minimum-spin, minimum-isospin channels and two additional
K channels are most conducive to the formation of bound states.
Related interesting topics for future experimental and theoretical studies of
KN interactions are also discussed.Comment: 34 pages, figures available from the authors, revte
NN Core Interactions and Differential Cross Sections from One Gluon Exchange
We derive nonstrange baryon-baryon scattering amplitudes in the
nonrelativistic quark model using the ``quark Born diagram" formalism. This
approach describes the scattering as a single interaction, here the
one-gluon-exchange (OGE) spin-spin term followed by constituent interchange,
with external nonrelativistic baryon wavefunctions attached to the scattering
diagrams to incorporate higher-twist wavefunction effects. The short-range
repulsive core in the NN interaction has previously been attributed to this
spin-spin interaction in the literature; we find that these perturbative
constituent-interchange diagrams do indeed predict repulsive interactions in
all I,S channels of the nucleon-nucleon system, and we compare our results for
the equivalent short-range potentials to the core potentials found by other
authors using nonperturbative methods. We also apply our perturbative
techniques to the N and systems: Some
channels are found to have attractive core potentials and may accommodate
``molecular" bound states near threshold. Finally we use our Born formalism to
calculate the NN differential cross section, which we compare with experimental
results for unpolarised proton-proton elastic scattering. We find that several
familiar features of the experimental differential cross section are reproduced
by our Born-order result.Comment: 27 pages, figures available from the authors, revtex, CEBAF-TH-93-04,
MIT-CTP-2187, ORNL-CCIP-93-0
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47Ă10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58Ă10-8, Ω0V<6.35Ă10-8, and Ω0S<1.08Ă10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4Ă10-5 and 9.4Ă10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society
Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)
[no abstract available
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4Ă10-5 and 9.4Ă10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society
Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b
We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society
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