197 research outputs found
Abundance and length-weight relationship of commercial demersal fish species in the Belgian North Sea
Reports of injury risks and reasons for choice of sleep environments for infants and toddlers
OBJECTIVE: Compare mothers\u27 reports of injuries for infants and toddlers sleeping with crib-bumpers/mesh-liners/no-barriers and reasons for these sleep environment choices.
METHODS: A cross-sectional survey of mothers subscribing to a parenting magazine and using crib bumpers (n = 224), mesh liners (n = 262), and no barriers (n = 842). Analyses of four possible injuries (face-covered, climb-out/fall, slat-entrapment, hit-head) including multivariate logistic regression adjusted for missing data/demographics and Chi squared analyses of reasons for mothers\u27 choices.
RESULTS: Maternal reports of finding infants/toddlers with face covered had 3.5 times higher adjusted odds (aOR) for crib bumper versus mesh liner use. Breathing difficulties and wedgings were reported for infants/toddlers using crib bumpers but not mesh liners. Climb-outs/falls showed no significant difference in aORs for crib bumpers versus no-barriers and mesh liners versus no barriers. Reports of slat-entrapment were less likely for mothers using crib bumpers and mesh liners than using no barrier (aOR = .28 and .32). Reports of hit-heads were less likely for crib bumpers vs no barrier (aOR = .38) with no significant difference between mesh liners versus no barrier use. Mothers using crib bumpers and mesh liners felt their choice prevented slat-entrapment (89%, 91%); 93.5% of crib bumper users felt their choice prevented hit-heads. Significantly more mesh liner than crib bumper users chose them because There is no suffocation risk (64.1% vs. 40.6%), while 83.6% of no-barrier users chose them because I was concerned about suffocation risk.
CONCLUSIONS FOR PRACTICE: Mothers appeared to be more concerned about preventing minor risks than suffocation. Understanding reasons for mothers\u27 use of barriers/no-barriers is important in tailoring counseling for mothers with infants/toddlers
Detailed study of the GRB 030329 radio afterglow deep into the non-relativistic phase
We explore the physics behind one of the brightest radio afterglows ever, GRB
030329, at late times when the jet is non-relativistic. We determine the
physical parameters of the blast wave and its surroundings, in particular the
index of the electron energy distribution, the energy of the blast wave, and
the density (structure) of the circumburst medium. We then compare our results
with those from image size measurements. We observed the GRB 030329 radio
afterglow with the Westerbork Synthesis Radio Telescope and the Giant Metrewave
Radio Telescope at frequencies from 325 MHz to 8.4 GHz, spanning a time range
of 268-1128 days after the burst. We modeled all the available radio data and
derived the physical parameters. The index of the electron energy distribution
is p=2.1, the circumburst medium is homogeneous, and the transition to the
non-relativistic phase happens at t_NR ~ 80 days. The energy of the blast wave
and density of the surrounding medium are comparable to previous findings. Our
findings indicate that the blast wave is roughly spherical at t_NR, and they
agree with the implications from the VLBI studies of image size evolution. It
is not clear from the presented dataset whether we have seen emission from the
counter jet or not. We predict that the Low Frequency Array will be able to
observe the afterglow of GRB 030329 and many other radio afterglows,
constraining the physics of the blast wave during its non-relativistic phase
even further.Comment: 9 pages, 2 figures; accepted for publication in Astronomy &
Astrophysics after minor revisions; small changes in GMRT fluxes at 1280 MH
The LOFAR Transients Pipeline
Current and future astronomical survey facilities provide a remarkably rich
opportunity for transient astronomy, combining unprecedented fields of view
with high sensitivity and the ability to access previously unexplored
wavelength regimes. This is particularly true of LOFAR, a
recently-commissioned, low-frequency radio interferometer, based in the
Netherlands and with stations across Europe. The identification of and response
to transients is one of LOFAR's key science goals. However, the large data
volumes which LOFAR produces, combined with the scientific requirement for
rapid response, make automation essential. To support this, we have developed
the LOFAR Transients Pipeline, or TraP. The TraP ingests multi-frequency image
data from LOFAR or other instruments and searches it for transients and
variables, providing automatic alerts of significant detections and populating
a lightcurve database for further analysis by astronomers. Here, we discuss the
scientific goals of the TraP and how it has been designed to meet them. We
describe its implementation, including both the algorithms adopted to maximize
performance as well as the development methodology used to ensure it is robust
and reliable, particularly in the presence of artefacts typical of radio
astronomy imaging. Finally, we report on a series of tests of the pipeline
carried out using simulated LOFAR observations with a known population of
transients.Comment: 30 pages, 11 figures; Accepted for publication in Astronomy &
Computing; Code at https://github.com/transientskp/tk
An automated archival VLA transients survey
In this paper we present the results of a survey for radio transients using
data obtained from the Very Large Array archive. We have reduced, using a
pipeline procedure, 5037 observations of the most common pointings - i.e. the
calibrator fields. These fields typically contain a relatively bright point
source and are used to calibrate `target' observations: they are therefore
rarely imaged themselves. The observations used span a time range ~ 1984 - 2008
and consist of eight different pointings, three different frequencies (8.4, 4.8
and 1.4 GHz) and have a total observing time of 435 hours. We have searched for
transient and variable radio sources within these observations using components
from the prototype LOFAR transient detection system. In this paper we present
the methodology for reducing large volumes of Very Large Array data; and we
also present a brief overview of the prototype LOFAR transient detection
algorithms. No radio transients were detected in this survey, therefore we
place an upper limit on the snapshot rate of GHz frequency transients > 8.0 mJy
to rho less than or equal to 0.032 deg^-2 that have typical timescales 4.3 to
45.3 days. We compare and contrast our upper limit with the snapshot rates -
derived from either detections or non-detections of transient and variable
radio sources - reported in the literature. When compared with the current Log
N - Log S distribution formed from previous surveys, we show that our upper
limit is consistent with the observed population. Current and future radio
transient surveys will hopefully further constrain these statistics, and
potentially discover dominant transient source populations. In this paper we
also briefly explore the current transient commissioning observations with
LOFAR, and the impact they will make on the field.Comment: Accepted for publication in MNRA
Associations of sitting accumulation patterns with cardio-metabolic risk biomarkers in Australian adults
Backgroun
Attaching metabolic expenditures to standard occupational classification systems: perspectives from time-use research
Understanding how immigrant entrepreneurs view business opportunity formation through ethnicity
Given that international research is now consistently showing higher rates of entrepreneurial activity from immigrants above native people, research regarding our understanding of how immigrant entrepreneurs view business opportunity formation remains underdeveloped. Based upon a review of the literature, this chapter examines how ethnicity relates to business opportunity formation through constant interactions. It also introduces the Visual Mixed Embeddedness Framework as an empirical lens for understanding the differences in the business opportunity formation process models between immigrant and native entrepreneurs. By explaining how factors and traits from both home and host countries impact upon the immigrant entrepreneurial business activity process, the framework clearly identifies how the concept of ethnicity influences immigrant entrepreneurial opportunity formation activities in different ways. The framework contributes to existing knowledge by offering a novel method for examining the influence on business opportunity formation of ethnicity, the role of home and host countries and variations between immigrant and native entrepreneurs
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