592 research outputs found
Fitness and health-related quality of life dimensions in community-dwelling middle aged and older adults
<p>Abstract</p> <p>Background</p> <p>The aim of the present study was to identify the physical fitness (PF) tests of a multi-component battery more related to the perception of problems in each dimension of the health-related quality of life (HRQoL) assessed by the EuroQol 5 dimensions 3 level questionnaire (EQ-5D-3L) in community-dwelling middle-aged and older adults</p> <p>Methods</p> <p>A cross-sectional study was conducted with 7104 participants (6243 females and 861 males aged 50-99 years) who were recruited in the framework of the Exercise Looks After You Program, which is a public health program designed to promote physical activity (PA) in community-dwelling middle-aged and older adults. Participants were assessed by the EQ-5D-3L questionnaire and a battery of fitness tests. The responses to each EQ-5D-3L dimension were collapsed into a two-tier variable consisting of «perceive problems» and «do not perceive problems». Correlation coefficients for the relationships between the HRQoL variables, between the PF variables, and between the HRQoL and PF variables were obtained. Two logistic regression models, one adjusted and one unadjusted, were developed for each EQ-5D-3L dimension.</p> <p>Results</p> <p>There were significant correlations between all variables except anxiety/depression and the back scratch test. The PF tests that correlated best with the HRQoL dimensions were the Timed Up-and-Go Test (TUG) and the 6-min walk; pain/discomfort and anxiety/depression correlated less well. All PF tests correlated, especially the TUG and 6-min walk tests. Unadjusted logistic models showed significant goodness of fit for the mobility and pain/discomfort dimensions only. Adjusted logistic models showed significant goodness of fit for all dimensions when the following potential confounding variables were included: age, gender, weekly level of PA, smoking and alcohol habits, body mass index, and educational level. For all dimensions, the highest odds ratios for the association with PF tests were with the TUG; this was observed with both the unadjusted and adjusted models.</p> <p>Conclusions</p> <p>The perception of problems, as measured by the EQ-5D-3L dimensions, was associated with a lower level of fitness, particularly for those dimensions that relate more closely to physical components. The PF tests that associated most closely with the perception of problems in the HRQoL dimensions were the TUG and the 6-min walk. This information will aid the design and assessment of PA programs that aim to improve HRQoL.</p
The Pristine survey II: a sample of bright stars observed with FEROS
Extremely metal-poor (EMP) stars are old objects formed in the first Gyr of
the Universe. They are rare and, to select them, the most successful strategy
has been to build on large and low-resolution spectroscopic surveys. The
combination of narrow- and broad band photometry provides a powerful and
cheaper alternative to select metal-poor stars. The on-going Pristine Survey is
adopting this strategy, conducting photometry with the CFHT MegaCam wide field
imager and a narrow-band filter centred at 395.2 nm on the CaII-H and -K lines.
In this paper we present the results of the spectroscopic follow-up conducted
on a sample of 26 stars at the bright end of the magnitude range of the Survey
(g<=15), using FEROS at the MPG/ESO 2.2 m telescope. From our chemical
investigation on the sample, we conclude that this magnitude range is too
bright to use the SDSS gri bands, which are typically saturated. Instead the
Pristine photometry can be usefully combined with the APASS gri photometry to
provide reliable metallicity estimates.Comment: AN accepte
A Study of the Near-Ultraviolet Spectrum of Vega
UV, optical, and near-IR spectra of Vega have been combined to test our
understanding of stellar atmospheric opacities, and to examine the possibility
of constraining chemical abundances from low-resolution UV fluxes. We have
carried out a detailed analysis assuming Local Thermodynamic Equilibrium (LTE)
to identify the most important contributors to the UV continuous opacity: H,
H, C I, and Si II. Our analysis also assumes that Vega is spherically
symmetric and its atmosphere is well described with the plane parallel
approximation. Comparing observations and computed fluxes we have been able to
discriminate between two different flux scales that have been proposed, the
IUE-INES and the HST scales, favoring the latter. The effective temperature and
angular diameter derived from the analysis of observed optical and near-UV
spectra are in very good agreement with previous determinations based on
different techniques. The silicon abundance is poorly constrained by the UV
observations of the continuum and strong lines, but the situation is more
favorable for carbon and the abundances inferred from the UV continuum and
optical absorption lines are in good agreement. Some spectral intervals in the
UV spectrum of Vega that the calculations do not reproduce well are likely
affected by deviations from LTE, but we conclude that our understanding of UV
atmospheric opacities is fairly complete for early A-type stars.Comment: 13 pages, 9 figures, to be published in Ap
First-Principles Simulations of Lithium Melting: Stability of the bcc Phase Close to Melting
We report large-scale first-principles simulations of melting of four different phases of Li at pressures ranging from 0 to 50 GPa. We find excellent agreement with existing experimental data at low pressures, and confirm that above 10 GPa the melting line develops a negative slope, in parallel to what occurs for Na at 30 GPa. Surprisingly, our results indicate that the melting temperature of the bcc phase is always higher than that of fcc Li, suggesting the intriguing possibility of the existence of a narrow field of bcc stability separating the fcc and liquid phases, as predicted by Alexander and McTague [Phys. Rev. Lett. 41, 702 (1978)]
the SDSS-III APOGEE Spectral Line List for H-Band Spectroscopy
We present the H-band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretical, and laboratory sources from the literature, as well as newly evaluated astrophysical oscillator strengths and damping parameters. We discuss the construction of the APOGEE line list, which is one of the critical inputs for the APOGEE Stellar Parameters and Chemical Abundances Pipeline, and present three different versions that have been used at various stages of the project. The methodology for the newly calculated astrophysical line lists is reviewed. The largest of these three line lists contains 134,457 molecular and atomic transitions. In addition to the format adopted to store the data, the line lists are available in MOOG, Synspec, and Turbospectrum formats. The limitations of the line lists along with guidance for its use on different spectral types are discussed. We also present a list of H-band spectral features that are either poorly represented or completely missing in our line list. This list is based on the average of a large number of spectral fit residuals for APOGEE observations spanning a wide range of stellar parameters.Alfred P. Sloan FoundationNational Science FoundationU.S. Department of Energy Office of ScienceJanos Bolyai Research Scholarship of the Hungarian Academy of SciencesSpanish Ministry of Economy and Competitiveness AYA-2011-27754, AYA-2014-58082-PRSF 14-50-00043McDonald Observator
New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE survey
The Sloan Digital Sky Survey--III (SDSS--III) Apache Point Observatory
Galactic Evolution Experiment (APOGEE) has obtained high resolution (R
22,500), high signal-to-noise ratio ( 100) spectra in the Hband
(1.51.7 m) for about 146,000 stars in the Milky Way galaxy. We
have computed spectral libraries with effective temperature ()
ranging from 3500 to 8000 K for the automated chemical analy\-sis of the survey
data. The libraries, used to derive stellar parameters and abundances from the
APOGEE spectra in the SDSS--III data release 12 (DR12), are based on ATLAS9
model atmospheres and the ASST spectral synthesis code. We present a
second set of libraries based on MARCS model atmospheres and the spectral
synthesis code Turbospectrum. The ATLAS9/ASST ( =
35008000 K) and MARCS/Turbospectrum ( = 35005500 K) grids
cover a wide range of metallicity (2.5 [M/H] 0.5 dex),
surface gravity (0 log 5 dex), microturbulence (0.5
8 km~s), carbon (1 [C/M] 1 dex),
nitrogen (1 [N/M] 1 dex), and -element (1
[/M] 1 dex) variations, having thus seven dimensions. We
compare the ATLAS9/ASST and MARCS/Turbospectrum libraries and apply
both of them to the analysis of the observed Hband spectra of the Sun and
the K2 giant Arcturus, as well as to a selected sample of well-known giant
stars observed at very high-resolution. The new APOGEE libraries are publicly
available and can be employed for chemical studies in the Hband using other
high-resolution spectrographs.Comment: 45 pages, 11 figures; accepted for publication in the Astronomical
Journa
Molecular and biochemical characterization of glucose transport in Torulaspora delbrueckii
Apresentação efectuada no "XIV Congresso Nacional de Bioquímica", em Vilamoura, Portugal, em Dezembro de 2004
New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE Survey
The Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) has obtained high-resolution (R ~ 22,500), high signal-to-noise ratio (\gt 100) spectra in the H-band (~1.5--1.7 mum) for about 146,000 stars in the Milky Way galaxy. We have computed spectral libraries with effective temperature ({{T}eff}) ranging from 3500 to 8000 K for the automated chemical analysis of the survey data. The libraries, used to derive stellar parameters and abundances from the APOGEE spectra in the SDSS-III data release 12 (DR12), are based on ATLAS9 model atmospheres and the ASSεT spectral synthesis code. We present a second set of libraries based on MARCS model atmospheres and the spectral synthesis code Turbospectrum. The ATLAS9/ASSεT ({{T}eff} = 3500--8000 K) and MARCS/Turbospectrum ({{T}eff} = 3500--5500 K) grids cover a wide range of metallicity (-2.5 -1), carbon (-1 <=slant [C/M] <=slant +1 dex), nitrogen (-1 <=slant [N/M] <=slant +1 dex), and alpha-element (-1 <=slant [alpha/M] <=slant +1 dex) variations, having thus seven dimensions. We compare the ATLAS9/ASSεT and MARCS/Turbospectrum libraries and apply both of them to the analysis of the observed H-band spectra of the Sun and the K2 giant Arcturus, as well as to a selected sample of well-known giant stars observed at very high resolution. The new APOGEE libraries are publicly available and can be employed for chemical studies in the H-band using other high-resolution spectrographs
Chemical abundance gradients from open clusters in the Milky Way disk: results from the APOGEE survey
Metallicity gradients provide strong constraints for understanding the
chemical evolution of the Galaxy. We report on radial abundance gradients of
Fe, Ni, Ca, Si, and Mg obtained from a sample of 304 red-giant members of 29
disk open clusters, mostly concentrated at galactocentric distances between ~8
- 15 kpc, but including two open clusters in the outer disk. The observations
are from the APOGEE survey. The chemical abundances were derived automatically
by the ASPCAP pipeline and these are part of the SDSS III Data Release 12. The
gradients, obtained from least squares fits to the data, are relatively flat,
with slopes ranging from -0.026 to -0.033 dex/kpc for the alpha-elements [O/H],
[Ca/H], [Si/H] and [Mg/H] and -0.035 dex/kpc and -0.040 dex/kpc for [Fe/H] and
[Ni/H], respectively. Our results are not at odds with the possibility that
metallicity ([Fe/H]) gradients are steeper in the inner disk (R_GC ~7 - 12 kpc)
and flatter towards the outer disk. The open cluster sample studied spans a
significant range in age. When breaking the sample into age bins, there is some
indication that the younger open cluster population in our sample (log age <
8.7) has a flatter metallicity gradient when compared with the gradients
obtained from older open clusters.Comment: 4 pages, 3 figures, To appear in Astronomische Nachrichten, special
issue "Reconstruction the Milky Way's History: Spectroscopic surveys,
Asteroseismology and Chemo-dynamical models", Guest Editors C. Chiappini, J.
Montalb\'an, and M. Steffen, AN 2016 (in press)
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The SDSS-III APOGEE Radial Velocity Survey Of M Dwarfs. I. Description Of The Survey And Science Goals
We are carrying out a large ancillary program with the Sloan Digital Sky Survey, SDSS-III, using the fiber-fed multi-object near-infrared APOGEE spectrograph, to obtain high-resolution H-band spectra of more than 1200 M dwarfs. These observations will be used to measure spectroscopic rotational velocities, radial velocities, physical stellar parameters, and variability of the target stars. Here, we describe the target selection for this survey, as well as results from the first year of scientific observations based on spectra that will be publicly available in the SDSS-III DR 10 data release. As part of this paper we present radial velocities and rotational velocities of over 200 M dwarfs, with a v sin i precision of similar to 2 km s(-1) a measurement floor at v sin i = 4 km s(-1). This survey significantly increases the number of M dwarfs studied for rotational velocities and radial velocity variability (at similar to 100-200 m s(-1)), and will inform and advance the target selection for planned radial velocity and photometric searches for low-mass exoplanets around M dwarfs, such as the Habitable Zone Planet Finder, CARMENES, and TESS. Multiple epochs of radial velocity observations enable us to identify short period binaries, and adaptive optics imaging of a subset of stars enables the detection of possible stellar companions at larger separations. The high-resolution APOGEE spectra, covering the entire H band, provide the opportunity to measure physical stellar parameters such as effective temperatures and metallicities for many of these stars. At the culmination of this survey, we will have obtained multi-epoch spectra and radial velocities for over 1400 stars spanning the spectral range M0-L0, providing the largest set of near-infrared M dwarf spectra at high resolution, and more than doubling the number of known spectroscopic a sin i values for M dwarfs. Furthermore, by modeling telluric lines to correct for small instrumental radial velocity shifts, we hope to achieve a relative velocity precision floor of 50 m s(-1) for bright M dwarfs. With three or more epochs, this precision is adequate to detect substellar companions, including giant planets with short orbital periods, and flag them for higher-cadence followup. We present preliminary, and promising, results of this telluric modeling technique in this paper.Center for Exoplanets and Habitable WorldsPennsylvania State UniversityEberly College of SciencePennsylvania Space Grant ConsortiumNSF AST 1006676, AST 1126413National Science FoundationNational Aeronautics and Space Administration NNX-08AE38A, NNX13AB03GAlfred P. Sloan FoundationU.S. Department of Energy Oce of ScienceUniversity of ArizonaBrazilian Participation GroupBrookhaven National LaboratoryUniversity of CambridgeCarnegie Mellon UniversityUniversity of FloridaFrench Participation GroupGerman Participation GroupHarvard UniversityInstituto de Astrosica de CanariasMichigan State/Notre Dame/JINA Participation GroupJohns Hopkins UniversityLawrence Berkeley National LaboratoryMax Planck Institute for AstrophysicsMax Planck Institute for Extraterrestrial PhysicsNew Mexico State UniversityNew York UniversityOhio State UniversityUniversity of PortsmouthPrinceton UniversitySpanish Participation GroupUniversity of TokyoUniversity of UtahVanderbilt UniversityUniversity of VirginiaUniversity of WashingtonYale UniversityMcDonald Observator
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