623 research outputs found
Antecedents and outcomes of consumer environmentally friendly attitudes and behaviour
With the intensification of problems relating to the environment, a growing number of consumers are becoming more ecologically conscious in their preferences and purchases of goods. This paper presents the results of a study conducted among 500 Cypriot consumers, focusing on the factors that shape consumer environmental attitudes and behaviour, as well as on the resulting outcomes. The findings confirmed that both the inward and outward environmental attitudes of a consumer are positively influenced by his/her degree of collectivism, long-term orientation, political involvement, deontology, and law obedience, but have no connection with liberalism. The adoption of an inward environmental attitude was also found to be conducive to green purchasing behaviour that ultimately leads to high product satisfaction. On the other hand, an outward environmental attitude facilitates the adoption of a general environmental behaviour, which is responsible for greater satisfaction with life. The findings of the study have important implications for shaping effective company offerings to consumers in target markets, as well as formulating appropriate policies at the governmental level to enhance environmental sensitivity among citizens
Chemical Abundance Analysis of Tucana III, the Second -process Enhanced Ultra-Faint Dwarf Galaxy
We present a chemical abundance analysis of four additional confirmed member
stars of Tucana III, a Milky Way satellite galaxy candidate in the process of
being tidally disrupted as it is accreted by the Galaxy. Two of these stars are
centrally located in the core of the galaxy while the other two stars are
located in the eastern and western tidal tails. The four stars have chemical
abundance patterns consistent with the one previously studied star in Tucana
III: they are moderately enhanced in -process elements, i.e. they have
0.4 dex. The non-neutron-capture elements generally
follow trends seen in other dwarf galaxies, including a metallicity range of
0.44 dex and the expected trend in -elements, i.e., the lower
metallicity stars have higher Ca and Ti abundance. Overall, the chemical
abundance patterns of these stars suggest that Tucana III was an ultra-faint
dwarf galaxy, and not a globular cluster, before being tidally disturbed. As is
the case for the one other galaxy dominated by -process enhanced stars,
Reticulum II, Tucana III's stellar chemical abundances are consistent with
pollution from ejecta produced by a binary neutron star merger, although a
different -process element or dilution gas mass is required to explain the
abundances in these two galaxies if a neutron star merger is the sole source of
-process enhancement.Comment: 18 pages, 10 figures; accepted by Ap
Quasar accretion disk sizes from continuum reverberation mapping in the DES standard-star fields
Measurements of the physical properties of accretion disks in active galactic
nuclei are important for better understanding the growth and evolution of
supermassive black holes. We present the accretion disk sizes of 22 quasars
from continuum reverberation mapping with data from the Dark Energy Survey
(DES) standard star fields and the supernova C fields. We construct continuum
lightcurves with the \textit{griz} photometry that span five seasons of DES
observations. These data sample the time variability of the quasars with a
cadence as short as one day, which corresponds to a rest frame cadence that is
a factor of a few higher than most previous work. We derive time lags between
bands with both JAVELIN and the interpolated cross-correlation function method,
and fit for accretion disk sizes using the JAVELIN Thin Disk model. These new
measurements include disks around black holes with masses as small as
, which have equivalent sizes at 2500\AA \, as small as
light days in the rest frame. We find that most objects have
accretion disk sizes consistent with the prediction of the standard thin disk
model when we take disk variability into account. We have also simulated the
expected yield of accretion disk measurements under various observational
scenarios for the Large Synoptic Survey Telescope Deep Drilling Fields. We find
that the number of disk measurements would increase significantly if the
default cadence is changed from three days to two days or one day.Comment: 33 pages, 24 figure
Astrometric calibration and performance of the Dark Energy Camera
We characterize the ability of the Dark Energy Camera (DECam) to perform
relative astrometry across its 500~Mpix, 3 deg^2 science field of view, and
across 4 years of operation. This is done using internal comparisons of ~4x10^7
measurements of high-S/N stellar images obtained in repeat visits to fields of
moderate stellar density, with the telescope dithered to move the sources
around the array. An empirical astrometric model includes terms for: optical
distortions; stray electric fields in the CCD detectors; chromatic terms in the
instrumental and atmospheric optics; shifts in CCD relative positions of up to
~10 um when the DECam temperature cycles; and low-order distortions to each
exposure from changes in atmospheric refraction and telescope alignment. Errors
in this astrometric model are dominated by stochastic variations with typical
amplitudes of 10-30 mas (in a 30 s exposure) and 5-10 arcmin coherence length,
plausibly attributed to Kolmogorov-spectrum atmospheric turbulence. The size of
these atmospheric distortions is not closely related to the seeing. Given an
astrometric reference catalog at density ~0.7 arcmin^{-2}, e.g. from Gaia, the
typical atmospheric distortions can be interpolated to 7 mas RMS accuracy (for
30 s exposures) with 1 arcmin coherence length for residual errors. Remaining
detectable error contributors are 2-4 mas RMS from unmodelled stray electric
fields in the devices, and another 2-4 mas RMS from focal plane shifts between
camera thermal cycles. Thus the astrometric solution for a single DECam
exposure is accurate to 3-6 mas (0.02 pixels, or 300 nm) on the focal plane,
plus the stochastic atmospheric distortion.Comment: Submitted to PAS
Forward Global Photometric Calibration of the Dark Energy Survey
Many scientific goals for the Dark Energy Survey (DES) require calibration of
optical/NIR broadband photometry that is stable in time and uniform
over the celestial sky to one percent or better. It is also necessary to limit
to similar accuracy systematic uncertainty in the calibrated broadband
magnitudes due to uncertainty in the spectrum of the source. Here we present a
"Forward Global Calibration Method (FGCM)" for photometric calibration of the
DES, and we present results of its application to the first three years of the
survey (Y3A1). The FGCM combines data taken with auxiliary instrumentation at
the observatory with data from the broad-band survey imaging itself and models
of the instrument and atmosphere to estimate the spatial- and time-dependence
of the passbands of individual DES survey exposures. "Standard" passbands are
chosen that are typical of the passbands encountered during the survey. The
passband of any individual observation is combined with an estimate of the
source spectral shape to yield a magnitude in the standard
system. This "chromatic correction" to the standard system is necessary to
achieve sub-percent calibrations. The FGCM achieves reproducible and stable
photometric calibration of standard magnitudes of stellar
sources over the multi-year Y3A1 data sample with residual random calibration
errors of per exposure. The accuracy of the
calibration is uniform across the DES footprint to
within . The systematic uncertainties of magnitudes in
the standard system due to the spectra of sources are less than
for main sequence stars with .Comment: 25 pages, submitted to A
Recommended from our members
H0LiCOW X: Spectroscopic/imaging survey and galaxy-group identification around the strong gravitational lens system WFI2033-4723
Galaxies and galaxy groups located along the line of sight towards
gravitationally lensed quasars produce high-order perturbations of the
gravitational potential at the lens position. When these perturbation are too
large, they can induce a systematic error on of a few-percent if the lens
system is used for cosmological inference and the perturbers are not explicitly
accounted for in the lens model. In this work, we present a detailed
characterization of the environment of the lens system WFI2033-4723 (, = 0.6575), one of the core targets of the H0LICOW
project for which we present cosmological inferences in a companion paper (Rusu
et al. 2019). We use the Gemini and ESO-Very Large telescopes to measure the
spectroscopic redshifts of the brightest galaxies towards the lens, and use the
ESO-MUSE integral field spectrograph to measure the velocity-dispersion of the
lens ( km/s) and of several nearby
galaxies. In addition, we measure photometric redshifts and stellar masses of
all galaxies down to mag, mainly based on Dark Energy Survey imaging
(DR1). Our new catalog, complemented with literature data, more than doubles
the number of known galaxy spectroscopic redshifts in the direct vicinity of
the lens, expanding to 116 (64) the number of spectroscopic redshifts for
galaxies separated by less than 3 arcmin (2 arcmin) from the lens. Using the
flexion-shift as a measure of the amplitude of the gravitational perturbation,
we identify 2 galaxy groups and 3 galaxies that require specific attention in
the lens models. The ESO MUSE data enable us to measure the
velocity-dispersions of three of these galaxies. These results are essential
for the cosmological inference analysis presented in Rusu et al. (2019).Comment: Matches the version accepted for publication by MNRAS. Note that this
paper previously appeared as H0LICOW X
On natural metalinguistic abilities in aphasia: a preliminary study
Natural metalinguistic abilities, which are put into play without explicit instructions, constitute the cognitive basis for a 'reflexive' use of language, a particular manifestation of the executive function when applied to language and verbal behaviour. This reflexive use entails a specific attentional activity by speakers and hearers with regard to linguistic outputs, and an intentional experience-based control over the language use. Putting into play natural metalinguistic abilities can be considered a significant factor for explaining different kinds of adaptive processes. Our results permit us to conclude that an impairment of metalinguistic abilities is involved in aphasia to different degrees. Moreover, the examination of preserved metalinguistic abilities provides an alternative way for assessing the degree of severity of impaired communicative behaviour by people with aphasia. Our procedure, presumably, will also be useful for suggesting new factors when designing therapeutic programmes
Bronchoscopist's perception of the quality of the single-use bronchoscope (Ambu aScope4™) in selected bronchoscopies: a multicenter study in 21 Spanish pulmonology services
Background: The disposable bronchoscope is an excellent alternative to face the problem of SARS-CoV-2 and other cross infections, but the bronchoscopist's perception of its quality has not been evaluated.
Methods: To evaluate the quality of the Ambu-aScope4 disposable bronchoscope, we carried out a cross-sectional study in 21 Spanish pulmonology services. We use a standardized questionnaire completed by the bronchoscopists at the end of each bronchoscopy. The variables were described with absolute and relative frequencies, measures of central tendency and dispersion depending on their nature. The existence of learning curves was evaluated by CUSUM analysis.
Results: The most frequent indications in 300 included bronchoscopies was bronchial aspiration in 69.3% and the median duration of these was 9.1 min. The route of entry was nasal in 47.2% and oral in 34.1%. The average score for ease of use, image, and aspiration quality was 80/100. All the planned techniques were performed in 94.9% and the bronchoscopist was satisfied in 96.6% of the bronchoscopies. They highlighted the portability and immediacy of the aScope4TM to start the procedure in 99.3%, the possibility of taking and storing images in 99.3%. The CUSUM analysis showed average scores > 70/100 from the first procedure and from the 9th procedure more than 80% of the scores exceeded the 80/100 score.
Conclusions: The aScope4™ scored well for ease of use, imaging, and aspiration. We found a learning curve with excellent scores from the 9th procedure. Bronchoscopists highlighted its portability, immediacy of use and the possibility of taking and storing images
- …