23,295 research outputs found
Duration and breaks in sedentary behaviour: Accelerometer data from 1566 community-dwelling older men (British Regional Heart Study)
Background: Sedentary behaviours are increasingly recognised as raising risk of CVD events, diabetes and mortality, independently of physical activity (PA) levels. However, little is known about patterns of sedentary behaviour in older adults. Methods: Cross sectional study of 1566/3137 (50% response) men aged 71-91 years from a UK population-based cohort study. Men wore a GT3x accelerometer over the hip for one week in 2010-11. Mean daily minutes of SB, % of day in sedentary behaviours, sedentary bouts and breaks were calculated and summarized by health and demographic characteristics. Results: 1403 ambulatory men aged 78.4 years (SD 4.6 years) with ≥600 minutes of accelerometer wear on ≥3 days had complete data on covariables. Men spent on average 618 minutes (SD=83), or 72% of their day in sedentary behaviours (<100 counts/minute). On average men accumulated 72 spells of sedentary behaviours per day, with 7 breaks in each sedentary hour. Men had on average 5.1 sedentary bouts of ≥30 minutes, which accounted for 43% of sedentary time, and 1.4 bouts of ≥60 minutes, which accounted for 19% of daily sedentary time. Men who were over 80 years old, obese, depressed and had multiple chronic conditions accumulated more sedentary time and spent more time in longer sedentary bouts. Conclusions: Older men spend nearly three quarters of their day in sedentary behaviours, mostly accumulated in short bouts, although bouts lasting ≥30 minutes accounted for nearly half of the sedentary time each day. Men with medical risk factors were more likely to also display sedentary behaviour
Stochastics theory of log-periodic patterns
We introduce an analytical model based on birth-death clustering processes to
help understanding the empirical log-periodic corrections to power-law scaling
and the finite-time singularity as reported in several domains including
rupture, earthquakes, world population and financial systems. In our
stochastics theory log-periodicities are a consequence of transient clusters
induced by an entropy-like term that may reflect the amount of cooperative
information carried by the state of a large system of different species. The
clustering completion rates for the system are assumed to be given by a simple
linear death process. The singularity at t_{o} is derived in terms of
birth-death clustering coefficients.Comment: LaTeX, 1 ps figure - To appear J. Phys. A: Math & Ge
Luminosity Functions of Elliptical Galaxies at z < 1.2
The luminosity functions of E/S0 galaxies are constructed in 3 different
redshift bins (0.2 < z < 0.55, 0.55 < z < 0.8, 0.8 < z < 1.2), using the data
from the Hubble Space Telescope Medium Deep Survey (HST MDS) and other HST
surveys. These independent luminosity functions show the brightening in the
luminosity of E/S0s by about 0.5~1.0 magnitude at z~1, and no sign of
significant number evolution.
This is the first direct measurement of the luminosity evolution of E/S0
galaxies, and our results support the hypothesis of a high redshift of
formation (z > 1) for elliptical galaxies, together with weak evolution of the
major merger rate at z < 1.Comment: To be published in ApJ Letters, 4 pages, AAS Latex, 4 figures, and 2
table
Inpatient telemedicine and new models of care during COVID-19: hospital design strategies to enhance patient and staff safety
The challenges of the COVID-19 pandemic have led to the development of new hospital design strategies and models of care. To enhance staff safety while preserving patient safety and quality of care, hospitals have created a new model of remote inpatient care using telemedicine technologies. The design of the COVID-19 units divided the space into contaminated and clean zones and integrated a control room with audio-visual technologies to remotely supervise, communicate, and support the care being provided in the contaminated zone. The research is based on semi-structured interviews and observations of care processes that implemented a new model of inpatient telemedicine at Sheba Medical Center in Israel in different COVID-19 units, including an intensive care unit (ICU) and internal medicine unit (IMU). The study examines the impact of the diverse design layouts of the different units associated with the implementation of digital technologies for remote care on patient and staff safety. The results demonstrate the challenges and opportunities of integrating inpatient telemedicine for critical and intermediate care to enhance patient and staff safety. We contribute insights into the design of hospital units to support new models of remote care and suggest implications for Evidence-based Design (EBD), which will guide much needed future research
Spin splitting of X-related donor impurity states in an AlAs barrier
We use magnetotunneling spectroscopy to observe the spin splitting of the
ground state of an X-valley-related Si-donor impurity in an AlAs barrier. We
determine the absolute magnitude of the effective Zeeman spin splitting factors
of the impurity ground state to be g= 2.2 0.1. We also investigate
the spatial form of the electron wave function of the donor ground state, which
is anisotropic in the growth plane
A luminous blue kilonova and an off-axis jet from a compact binary merger at z=0.1341
The recent discovery of a faint gamma-ray burst (GRB) coincident with the
gravitational wave (GW) event GW 170817 revealed the existence of a population
of low-luminosity short duration gamma-ray transients produced by neutron star
mergers in the nearby Universe. These events could be routinely detected by
existing gamma-ray monitors, yet previous observations failed to identify them
without the aid of GW triggers. Here we show that GRB150101B was an analogue of
GRB170817A located at a cosmological distance. GRB 150101B was a faint short
duration GRB characterized by a bright optical counterpart and a long-lived
X-ray afterglow. These properties are unusual for standard short GRBs and are
instead consistent with an explosion viewed off-axis: the optical light is
produced by a luminous kilonova component, while the observed X-rays trace the
GRB afterglow viewed at an angle of ~13 degrees. Our findings suggest that
these properties could be common among future electromagnetic counterparts of
GW sources.Comment: 28 pages, 8 figures, 2 tables. Accepted for publicatio
The X-ray spectrum of the Seyfert I galaxy Markarian 766: Dusty warm absorber or relativistic emission lines?
Competing models for broad spectral features in the soft X-ray spectrum of the Seyfert I galaxy Mrk 766 are tested against data from a 130 ks XMM-Newton observation. A model including relativistically broadened Lyalpha emission lines of O VIII N VII and C VI is a better fit to 0.3-2 keV XMM RGS data than a dusty warm absorber. Moreover, the measured depth of neutral iron absorption lines in the spectrum is inconsistent with the magnitude of the iron edge required to produce the continuum break at 17-18 Angstrom in the dusty warm absorber model. The relativistic emission line model can reproduce the broadband (0.1-12 keV) XMM EPIC data with the addition of a fourth line to represent emission from ionized iron at 6.7 keV and an excess due to reflection at energies above the iron line. The pro le of the 6.7 keV iron line is consistent with that measured for the low-energy lines. There is evidence in the RGS data, at the 3sigma level, of spectral features that vary with source flux. The covering fraction of warm absorber gas is estimated to be 12%. Iron in the warm absorber is found to be overabundant with respect to CNO, compared to solar values
The Earliest Near-infrared Time-series Spectroscopy of a Type Ia Supernova
We present ten medium-resolution, high signal-to-noise ratio near-infrared
(NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility
(IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained
as part of the Carnegie Supernova Project. This data set constitutes the
earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the
first spectrum obtained at 2.58 days past the explosion and covering -14.6 to
+17.3 days relative to B-band maximum. C I {\lambda}1.0693 {\mu}m is detected
in SN 2011fe with increasing strength up to maximum light. The delay in the
onset of the NIR C I line demonstrates its potential to be an effective tracer
of unprocessed material. For the first time in a SN Ia, the early rapid decline
of the Mg II {\lambda}1.0927 {\mu}m velocity was observed, and the subsequent
velocity is remarkably constant. The Mg II velocity during this constant phase
locates the inner edge of carbon burning and probes the conditions under which
the transition from deflagration to detonation occurs. We show that the Mg II
velocity does not correlate with the optical light-curve decline rate
{\Delta}m15. The prominent break at ~1.5 {\mu}m is the main source of concern
for NIR k-correction calculations. We demonstrate here that the feature has a
uniform time evolution among SNe Ia, with the flux ratio across the break
strongly correlated with {\Delta}m15. The predictability of the strength and
the onset of this feature suggests that the associated k-correction
uncertainties can be minimized with improved spectral templates.Comment: 14 pages, 13 figures, accepted for publication in Ap
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