468 research outputs found
Psychological distress of university workers during COVID-19 pandemic in Brazil
The study aimed to explore mental distress during COVID-19 quarantine in a sample of university workers in Brazil. The survey included sets of questions about demographics, health, and support, an open question about major concerns, and the Clinical Outcome Routine Evaluation (CORE-OM), a measure of mental distress. A total of 407 professionals, mean age 40, SD 11.2, fulfilling social distancing (99%) participated in the study. Participants were mostly female (67.8%) and married (64.8%). Using the Consensual Qualitative Research process for simple qualitative data (CQR-M), the main areas of concern were grouped into six domains, as follows: work, health, isolation, personal life and routine, social environment, and future. Many responses were multiple. They form categories indicating specific concerns within these domains. Quantitative data were analyzed by identifying the simple effects of potential predictors of mental distress. The results indicated medium effects of help with household chores (η2 = 0.06, 95% confidence interval (CI) (0.022–0.095)), psychiatric treatment (η2 = 0.06, CI (0.030–0.110)), age (η2 = 0.12, CI (0.070–0.170)), and physical exercise (η2 = 0.12, CI (0.079–0.180)). Having someone available to listen was the only variable with a large effect associated with reduced mental suffering (η2 = 0.18; CI (0.118–0.227)). Psychological experiences of the pandemic are multifaceted and complex. Thus, substantially larger surveys, with both quantitative and qualitative components, are needed
Intragroup diffuse light in compact groups of galaxies II. HCG 15, 35 and 51
This continuing study of intragroup light in compact groups of galaxies aims
to establish new constraints to models of formation and evolution of galaxy
groups, specially of compact groups, which are a key part in the evolution of
larger structures, such as clusters. In this paper we present three additional
groups (HCG 15, 35 and 51) using deep wide field and band images
observed with the LAICA camera at the 3.5m telescope at the Calar Alto
observatory (CAHA). This instrument provides us with very stable flatfielding,
a mandatory condition for reliably measuring intragroup diffuse light. The
images were analyzed with the OV\_WAV package, a wavelet technique that allows
us to uncover the intragroup component in an unprecedented way. We have
detected that 19, 15 and 26% of the total light of HCG 15, 35 and 51,
respectively, is in the diffuse component, with colours that are compatible
with old stellar populations and with mean surface brightness that can be as
low as . Dynamical masses, crossing times and
mass to light ratios were recalculated using the new group parameters. Also
tidal features were analyzed using the wavelet technique.Comment: 12 pages, 5 figures. Accepted for publication in MNRAS. See
http://www.eso.org/~cdarocha/publications/DaRochaetal2008_IGL_HCG.pdf for
full resolution version. Complementary reference adde
Resolving the age bimodality of galaxy stellar populations on kpc scales
Galaxies in the local Universe are known to follow bimodal distributions in
the global stellar populations properties. We analyze the distribution of the
local average stellar-population ages of 654,053 sub-galactic regions resolved
on ~1-kpc scales in a volume-corrected sample of 394 galaxies, drawn from the
CALIFA-DR3 integral-field-spectroscopy survey and complemented by SDSS imaging.
We find a bimodal local-age distribution, with an old and a young peak
primarily due to regions in early-type galaxies and star-forming regions of
spirals, respectively. Within spiral galaxies, the older ages of bulges and
inter-arm regions relative to spiral arms support an internal age bimodality.
Although regions of higher stellar-mass surface-density, mu*, are typically
older, mu* alone does not determine the stellar population age and a bimodal
distribution is found at any fixed mu*. We identify an "old ridge" of regions
of age ~9 Gyr, independent of mu*, and a "young sequence" of regions with age
increasing with mu* from 1-1.5 Gyr to 4-5 Gyr. We interpret the former as
regions containing only old stars, and the latter as regions where the relative
contamination of old stellar populations by young stars decreases as mu*
increases. The reason why this bimodal age distribution is not inconsistent
with the unimodal shape of the cosmic-averaged star-formation history is that
i) the dominating contribution by young stars biases the age low with respect
to the average epoch of star formation, and ii) the use of a single average age
per region is unable to represent the full time-extent of the star-formation
history of "young-sequence" regions.Comment: 17 pages, 11 figures, MNRAS accepte
Resolving the Stellar Outskirts of M31 and M33
Many clues about the galaxy assembly process lurk in the faint outer regions
of galaxies. The low surface brightnesses of these parts pose a significant
challenge for studies of diffuse light, and few robust constraints on galaxy
formation models have been derived to date from this technique. Our group has
pioneered the use of extremely wide-area star counts to quantitatively address
the large-scale structure and stellar content of external galaxies at very
faint light levels. We highlight here some results from our imaging and
spectroscopic surveys of M31 and M33.Comment: 6 pages, 4 figures. To appear in the proceedings of "Island Universes
- Structure and Evolution of Disk Galaxies", editor R.S. de Jong (Springer:
Dordrecht
The MAGNUM survey: Positive feedback in the nuclear region of NGC 5643 suggested by MUSE
We study the ionization and kinematics of the ionized gas in the nuclear
region of the barred Seyfert 2 galaxy NGC~5643 using MUSE integral field
observations in the framework of the MAGNUM (Measuring Active Galactic Nuclei
Under MUSE Microscope) survey. The data were used to identify regions with
different ionization conditions and to map the gas density and the dust
extinction. We find evidence for a double sided ionization cone, possibly
collimated by a dusty structure surrounding the nucleus. At the center of the
ionization cone, outflowing ionized gas is revealed as a blueshifted,
asymmetric wing of the [OIII] emission line, up to projected velocity
v(10)~-450 km/s. The outflow is also seen as a diffuse, low luminosity radio
and X-ray jet, with similar extension. The outflowing material points in the
direction of two clumps characterized by prominent line emission with spectra
typical of HII regions, located at the edge of the dust lane of the bar. We
propose that the star formation in the clumps is due to `positive feedback'
induced by gas compression by the nuclear outflow, providing the first
candidate for outflow induced star formation in a Seyfert-like radio quiet AGN.
This suggests that positive feedback may be a relevant mechanism in shaping the
black hole-host galaxy coevolution.Comment: 9 pages, 7 figures, accepted for publication in A&
Evolution of the Red Sequence Giant to Dwarf Ratio in Galaxy Clusters out to z ~ 0.5
We analyze deep g' and r' band data of 97 galaxy clusters imaged with MegaCam
on the Canada-France-Hawaii telescope. We compute the number of luminous
(giant) and faint (dwarf) galaxies using criteria based on the definitions of
de Lucia et al. (2007). Due to excellent image quality and uniformity of the
data and analysis, we probe the giant-to-dwarf ratio (GDR) out to z ~ 0.55.
With X-ray temperature (Tx) information for the majority of our clusters, we
constrain, for the first time, the Tx-corrected giant and dwarf evolution
separately. Our measurements support an evolving GDR over the redshift range
0.05 < z < 0.55. We show that modifying the (g'-r'), m_r' and K-correction used
to define dwarf and giant selection do not alter the conclusion regarding the
presence of evolution. We parameterize the GDR evolution using a linear
function of redshift (GDR = alpha * z + beta) with a best fit slope of alpha =
0.88 +/- 0.15 and normalization beta = 0.44 +/- 0.03. Contrary to claims of a
large intrinsic scatter, we find that the GDR data can be fully accounted for
using observational errors alone. Consistently, we find no evidence for a
correlation between GDR and cluster mass (via Tx or weak lensing). Lastly, the
data suggest that the evolution of the GDR at z < 0.2 is driven primarily by
dry merging of the massive giant galaxies, which when considered with previous
results at higher redshift, suggests a change in the dominant mechanism that
mediates the GDR.Comment: 20 pages, 15 figures. Accepted to MNRA
A new index to assess turning quality and postural stability in patients with Parkinson's disease
Parkinson's disease is a neuro-degenerative disorder characterized by the progressive death of dopamine neurons. This leads to delayed and uncoordinated movements, and impacts on the patients’ motor performance with reduced movement intensity, increased axial rigidity and impaired cadence regulation. Turning provides privileged insights in postural instability and fall prediction, as it is regularly performed during daily activities, requires multi-limb coordination. The objective of this work was to define a Quality of Movement (QoM) index, inferred from inertial data related to turns, and strictly correlated with the patient's motor conditions, postural stability, and stage of the disease. Such a concise representation finds its main application in the remote monitoring of patients during daily activities at home. We have recorded and analyzed 180° turns in 72 patients, using inertial sensors embedded in the smartphone. We have set up an algorithm for binary classification of patients: mild vs. moderate/severe conditions, according to the Hoehn and Yahr scale of disease progression and disability degree. Our QoM index is defined as the a posteriori probability output by this binary classifier. It exhibits high correlation (r = 0.73) with the clinical score of postural stability, as well as with the average of four clinical scores related to movement impairment (r = 0.75). These results, together with the widespread smartphone use, provide a step in the direction of a practical, objective and reliable tool for PD patients remote monitoring in domestic environment
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