138 research outputs found
Work Ability in Healthcare: Vulnerable Groups and Organizational Factors
The recent pandemic, along with heavy workloads and staff shortages, has placed significant pressure on healthcare workers. Maintaining adequate work ability is vital for ensuring favorable working conditions, mitigating stress, preventing related illnesses, and safeguarding worker performance and patient safety. This article assesses the work ability and working conditions of healthcare professionals at the University Hospital of Modena through a questionnaire administered between August 1, 2022, and September 30, 2022, to identify vulnerable groups and organizational factors influencing work ability. Among workers with reduced work ability, the majority are over 45 years old and female, 52% are obese, 64% have 3 or more illnesses, 47% report a poor work-life balance, and 50% have at least one dependent adult. Work characteristics are also highlighted as relevant: supervisor support and cooperation with colleagues, autonomy in decision-making processes, participation in the improvement of work processes, possession of skills appropriate to the tasks required, are associated with high levels of work ability. Finally, nurses and nurses aides are associated with lower work ability. Emergency and medical wards are particularly critical in terms of work ability when gender and age differences are taken into account
A Study of Carbon Features in Type Ia Supernova Spectra
One of the major differences between various explosion scenarios of Type Ia
supernovae (SNe Ia) is the remaining amount of unburned (C+O) material and its
velocity distribution within the expanding ejecta. While oxygen absorption
features are not uncommon in the spectra of SNe Ia before maximum light, the
presence of strong carbon absorption has been reported only in a minority of
objects, typically during the pre-maximum phase. The reported low frequency of
carbon detections may be due to low signal-to-noise data, low abundance of
unburned material, line blending between C II 6580 and Si II 6355, ejecta
temperature differences, asymmetrical distribution effects, or a combination of
these. However, a survey of published pre-maximum spectra reveals that more SNe
Ia than previously thought may exhibit C II 6580 absorption features and relics
of line blending near 6300 Angstroms. Here we present new SN Ia observations
where spectroscopic signatures of C II 6580 are detected, and investigate the
presence of C II 6580 in the optical spectra of 19 SNe Ia using the
parameterized spectrum synthesis code, SYNOW. Most of the objects in our sample
that exhibit C II 6580 absorption features are of the low-velocity gradient
subtype. Our study indicates that the morphology of carbon-rich regions is
consistent with either a spherical distribution or a hemispheric asymmetry,
supporting the recent idea that SN Ia diversity may be a result of off-center
ignition coupled with observer line-of-sight effects.Comment: 10 papges, 9 figures, 3 table
High-Velocity Features: a ubiquitous property of Type Ia SNe
Evidence of high-velocity features such as those seen in the near-maximum
spectra of some Type Ia Supernovae (eg SN 2000cx) has been searched for in the
available SNIa spectra observed earlier than one week before B maximum. Recent
observational efforts have doubled the number of SNeIa with very early spectra.
Remarkably, all SNeIa with early data (7 in our RTN sample and 10 from other
programmes) show signs of such features, to a greater or lesser degree, in CaII
IR, and some also in SiII 6255A line. High-velocity features may be interpreted
as abundance or density enhancements. Abundance enhancements would imply an
outer region dominated by Si and Ca. Density enhancements may result from the
sweeping up of circumstellar material by the highest velocity SN ejecta. In
this scenario, the high incidence of HVFs suggests that a thick disc and/or a
high-density companion wind surrounds the exploding white dwarf, as may be the
case in Single Degenerate systems. Large-scale angular fluctuations in the
radial density and abundance distribution may also be responsible: this could
originate in the explosion, and would suggest a deflagration as the more likely
explosion mechanism. CSM-interaction and surface fluctuations may coexist,
possibly leaving different signatures on the spectrum. In some SNe the HVFs are
narrowly confined in velocity, suggesting the ejection of blobs of burned
material.Comment: 12 pages, 2 figures, ApJ Letters in pres
Factors associated with SARS-CoV-2 infection risk among healthcare workers of an italian university hospital
We report the results of a study on the cumulative incidence of SARS-CoV-2 infections in about 6000 workers of the University Hospital of Modena, Northern Italy, in the period March 2020–January 2021, and the relations with some individual and occupational factors. Overall, in healthcare workers (HCW) the cumulative incidence of COVID-19 during the period was 13.8%. Results confirm the role of overweight and obesity as significant risk factors for SARS-CoV-2 infection. Chronic respiratory diseases, including asthma, also proved to be significantly associated with the infection rate. Considering occupational factors, the COVID-19 risk was about threefold (OR: 2.7; 95% CI 1.7–4.5) greater in nurses and nurse aides than in non-HCW, and about double (OR: 1.9; 95% CI 1.2–3.2) in physicians. Interestingly, an association was also observed between infection risk and nightshifts at work (OR: 1.8; 95% CI 1.4–2.3), significantly related to the total number of shifts in the whole eleven-month period. Even if the vaccination campaign has now greatly modified the scenario of SARS-CoV-2 infections among HCW, the results of this study can be useful for further development of health and policy strategies to mitigate the occupational risk related to the new variants of coronavirus, and therefore the evolution of the pandemic
NTT and NOT spectroscopy of SDSS-II supernovae
Context. The SDSS-II Supernova Survey, conducted between 2005 and 2007, was
designed to detect a large number of Type Ia supernovae (SNe Ia) around z~0.2,
the redshift "gap" between low-z and high-z SN searches. The survey has
provided multi-band photometric lightcurves for variable targets, and SN
candidates were scheduled for spectroscopic observations, primarily to provide
SN classification and accurate redshifts. We present SN spectra obtained in
2006 and 2007 using the NTT and the NOT. Aims. We provide an atlas of SN
spectra in the range z =0.03-0.32 that complements the well-sampled lightcurves
from SDSS-II in the forthcoming three-year SDSS SN cosmology analysis. The
sample can, for example, be used for spectral studies of SNe Ia, which are
critical for understanding potential systematic effects when SNe are used to
determine cosmological distances. Methods. The spectra were reduced in a
uniform manner, and special care was taken in estimating the uncertainties for
the different processing steps. Host-galaxy light was subtracted when possible
and the SN type fitted using the SuperNova IDentification code (SNID). We also
present comparisons between spectral and photometric dating using SALT
lightcurve fits to the photometry from SDSS-II, as well as the global
distribution of our sample in terms of the lightcurve parameters: stretch and
colour. Results. We report new spectroscopic data from 141 SNe Ia, mainly
between -9 and +15 days from lightcurve maximum, including a few cases of
multi-epoch observations. This homogeneous, host-galaxy subtracted, SN Ia
spectroscopic sample is among the largest such data sets and unique in its
redshift interval. The sample includes two potential SN 1991T-like SNe (SN
2006on and SN 2007ni) and one potential SN 2002cx-like SN (SN 2007ie). In
addition, the new compilation includes spectra from 23 confirmed Type II and 8
Type Ib/c SNe.Comment: Accepted for publication in A&
Restframe I-band Hubble diagram for type Ia supernovae up to redshift z ~0.5
We present a novel technique for fitting restframe I-band light curves on a
data set of 42 Type Ia supernovae (SNe Ia). Using the result of the fit, we
construct a Hubble diagram with 26 SNe from the subset at 0.01< z<0.1. Adding
two SNe at z~0.5 yields results consistent with a flat
Lambda-dominated``concordance universe''
()=(0.25,0.75). For one of these, SN 2000fr, new near
infrared data are presented. The high redshift supernova NIR data are also used
to test for systematic effects in the use of SNe Ia as distance estimators. A
flat, Lambda=0, universe where the faintness of supernovae at z~0.5 is due to
grey dust homogeneously distributed in the intergalactic medium is disfavoured
based on the high-z Hubble diagram using this small data-set. However, the
uncertainties are large and no firm conclusion may be drawn. We explore the
possibility of setting limits on intergalactic dust based on B-I and B-V colour
measurements, and conclude that about 20 well measured SNe are needed to give
statistically significant results. We also show that the high redshift
restframe I-band data points are better fit by light curve templates that show
a prominent second peak, suggesting that they are not intrinsically
underluminous.Comment: Accepted for publication in A&A (01/04/2005
Spectra of High-Redshift Type Ia Supernovae and a Comparison with their Low-Redshift Counterparts
We present spectra for 14 high-redshift (0.17 < z < 0.83) supernovae, which
were discovered by the Supernova Cosmology Project as part of a campaign to
measure cosmological parameters. The spectra are used to determine the redshift
and classify the supernova type, essential information if the supernovae are to
be used for cosmological studies. Redshifts were derived either from the
spectrum of the host galaxy or from the spectrum of the supernova itself. We
present evidence that these supernovae are of Type Ia by matching to spectra of
nearby supernovae. We find that the dates of the spectra relative to maximum
light determined from this fitting process are consistent with the dates
determined from the photometric light curves, and moreover the spectral
time-sequence for SNe Type Ia at low and high redshift is indistinguishable. We
also show that the expansion velocities measured from blueshifted CaHK are
consistent with those measured for low-redshift Type Ia supernovae. From these
first-level quantitative comparisons we find no evidence for evolution in SNIa
properties between these low- and high-redshift samples. Thus even though our
samples may not be complete, we conclude that there is a population of SNe Ia
at high redshift whose spectral properties match those at low redshift.Comment: Accepted for publication in AJ. Also available at
http://supernova.lbl.gov
Spectroscopic observations of eight supernovae at intermediate redshift
We present spectra of six Type Ia and two Type II supernovae obtained in June
2002 at the William Herschel Telescope during a search for Type Ia supernovae
(SNIa) at intermediate redshift. Supernova type identification and phase
determination are performed using a fitting technique based on a Xi2
minimization against a series of model templates. The spectra range from
z=0.033 to z=0.328, including one spectroscopically underluminous SNIa at
z=0.033. This set of spectra significantly increases the sample of
well-observed type SNIa supernovae available in the range 0.15< z <0.35.
Together with the twelve supernovae observed by our team in 1999 in the same
redshift range, they form an homogeneous sample of seventeen type Ia supernovae
with comparable signal-to-noise ratio and regular phase sampling in a still
largely unexplored region of the redshift space.Comment: 30 pages, 15 figures. Published in A&
The Spectroscopic Diversity of Type Ia Supernovae
We present 2603 spectra of 462 nearby Type Ia supernovae (SN Ia) obtained
during 1993-2008 through the Center for Astrophysics Supernova Program. Most of
the spectra were obtained with the FAST spectrograph at the FLWO 1.5m telescope
and reduced in a consistent manner, making data set well suited for studies of
SN Ia spectroscopic diversity. We study the spectroscopic and photometric
properties of SN Ia as a function of spectroscopic class using the
classification schemes of Branch et al. and Wang et al. The width-luminosity
relation appears to be steeper for SN Ia with broader lines. Based on the
evolution of the characteristic Si II 6355 line, we propose improved methods
for measuring velocity gradients, revealing a larger range than previously
suspected, from ~0 to ~400 km/s/day considering the instantaneous velocity
decline rate at maximum light. We find a weaker and less significant
correlation between Si II velocity and intrinsic B-V color at maximum light
than reported by Foley et al., owing to a more comprehensive treatment of
uncertainties and host galaxy dust. We study the extent of nuclear burning and
report new detections of C II 6580 in 23 early-time spectra. The frequency of C
II detections is not higher in SN Ia with bluer colors or narrower light
curves, in conflict with the recent results of Thomas et al. Based on nebular
spectra of 27 SN Ia, we find no relation between the FWHM of the iron emission
feature at ~4700 A and Dm15(B) after removing the two low-luminosity SN 1986G
and SN 1991bg, suggesting that the peak luminosity is not strongly dependent on
the kinetic energy of the explosion for most SN Ia. Finally, we confirm the
correlation of velocity shifts in some nebular lines with the intrinsic B-V
color of SN Ia at maximum light, although several outliers suggest a possible
non-monotonic behavior for the largest blueshifts.Comment: 36 pages (emulateapj), 23 figures. Accepted for publication in AJ.
Spectroscopic data available at
http://www.cfa.harvard.edu/supernova/SNarchive.html . New SNID template set
available at http://marwww.in2p3.fr/~blondin/software/snid/index.html . Minor
changes from v1 to conform to published versio
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