495 research outputs found
Against dichotomies: on mature care and self-sacrifice in care ethics
Introduction: In previous issues of this journal Carol Gilliganâs original concept of mature care has been conceptualized by several (especially Norwegian) contributors. This has resulted in a dichotomous view of self and other, and of self-care and altruism, in which any form of self-sacrifice is rejected. Although this interpretation of Gilligan seems to be quite persistent in care ethical theory, it does not seem to do justice to either Gilliganâs original work or the tensions experienced in contemporary nursing practice. Discussion: A close reading of Gilliganâs concept of mature care leads to a view that differs radically from any dichotomy of self-care and altruism. Instead of a dichotomous view, a dialectical view on self and other is proposed that builds upon connectedness and might support a care ethical view of nursing that is more consistent with Gilliganâs own critical insights such as relationality and a practice-based ethics. A concrete case taken from nursing practice shows the interconnectedness of professional and personal responsibility. This underpins a multilayered, complex view of self-realization that encompasses sacrifices as well. Conclusion: When mature care is characterized as a practice of a multilayered connectedness, caregivers can be acknowledged for their relational identity and nursing practices can be recognized as multilayered and interconnected. This view is better able to capture the tensions that are related to todayâs nursing as a practice, which inevitably includes sacrifices of self. In conclusion, a further discussion on normative conceptualizations of care is proposed that starts with a non-normative scrutiny of caring practices
Improving Cosmological Distance Measurements Using Twin Type Ia Supernovae
We introduce a method for identifying "twin" Type Ia supernovae, and using
them to improve distance measurements. This novel approach to Type Ia supernova
standardization is made possible by spectrophotometric time series observations
from the Nearby Supernova Factory (SNfactory). We begin with a well-measured
set of supernovae, find pairs whose spectra match well across the entire
optical window, and then test whether this leads to a smaller dispersion in
their absolute brightnesses. This analysis is completed in a blinded fashion,
ensuring that decisions made in implementing the method do not inadvertently
bias the result. We find that pairs of supernovae with more closely matched
spectra indeed have reduced brightness dispersion. We are able to standardize
this initial set of SNfactory supernovae to 0.083 +/- 0.012 magnitudes,
implying a dispersion of 0.072 +/- 0.010 magnitudes in the absence of peculiar
velocities. We estimate that with larger numbers of comparison SNe, e.g, using
the final SNfactory spectrophotometric dataset as a reference, this method will
be capable of standardizing high-redshift supernovae to within 0.06-0.07
magnitudes. These results imply that at least 3/4 of the variance in Hubble
residuals in current supernova cosmology analyses is due to previously
unaccounted-for astrophysical differences among the supernovaeComment: 37 pages, 9 figures, 5 tables. Accepted for publication in ApJ. Fixed
typo in arXiv abstrac
The Extinction Properties of and Distance to the Highly Reddened Type Ia Supernova SN 2012cu
Correction of Type Ia Supernova brightnesses for extinction by dust has
proven to be a vexing problem. Here we study the dust foreground to the highly
reddened SN 2012cu, which is projected onto a dust lane in the galaxy NGC 4772.
The analysis is based on multi-epoch, spectrophotometric observations spanning
3,300 - 9,200 {\AA}, obtained by the Nearby Supernova Factory. Phase-matched
comparison of the spectroscopically twinned SN 2012cu and SN 2011fe across 10
epochs results in the best-fit color excess of (E(B-V), RMS) = (1.00, 0.03) and
total-to-selective extinction ratio of (RV , RMS) = (2.95, 0.08) toward SN
2012cu within its host galaxy. We further identify several diffuse interstellar
bands, and compare the 5780 {\AA} band with the dust-to-band ratio for the
Milky Way. Overall, we find the foreground dust-extinction properties for SN
2012cu to be consistent with those of the Milky Way. Furthermore we find no
evidence for significant time variation in any of these extinction tracers. We
also compare the dust extinction curve models of Cardelli et al. (1989),
O'Donnell (1994), and Fitzpatrick (1999), and find the predictions of
Fitzpatrick (1999) fit SN 2012cu the best. Finally, the distance to NGC4772,
the host of SN 2012cu, at a redshift of z = 0.0035, often assigned to the Virgo
Southern Extension, is determined to be 16.61.1 Mpc. We compare this
result with distance measurements in the literature.Comment: 48 pages, 13 figures. Accepted for publication in The Astrophysical
Journal. The spectral time series data presented in this article can be found
at http://snfactory.lbl.gov/snf/data
The supernova CSS121015:004244+132827: a clue for understanding super-luminous supernovae
We present optical photometry and spectra of the super luminous type II/IIn
supernova CSS121015:004244+132827 (z=0.2868) spanning epochs from -30 days
(rest frame) to more than 200 days after maximum. CSS121015 is one of the more
luminous supernova ever found and one of the best observed. The photometric
evolution is characterized by a relatively fast rise to maximum (~40 days in
the SN rest frame), and by a linear post-maximum decline. The light curve shows
no sign of a break to an exponential tail. A broad Halpha is first detected at
~ +40 days (rest-frame). Narrow, barely-resolved Balmer and [O III] 5007 A
lines, with decreasing strength, are visible along the entire spectral
evolution. The spectra are very similar to other super luminous supernovae
(SLSNe) with hydrogen in their spectrum, and also to SN 2005gj, sometimes
considered a type Ia interacting with H-rich CSM. The spectra are also similar
to a subsample of H-deficient SLSNe. We propose that the properties of
CSS121015 are consistent with the interaction of the ejecta with a massive,
extended, opaque shell, lost by the progenitor decades before the final
explosion, although a magnetar powered model cannot be excluded. Based on the
similarity of CSS121015 with other SLSNe (with and without H), we suggest that
the shocked-shell scenario should be seriously considered as a plausible model
for both types of SLSN.Comment: 17 pages, 10 figures and 5 tables. In press to MNRAS. This version
matches the accepted one. Main conclusions are unchange
SN2012dn from early to late times: 09dc-like supernovae reassessed
As a candidate âsuper-Chandrasekharâ or 09dc-like Type Ia supernova (SN Ia), SN 2012dn shares many characteristics with other members of this remarkable class of objects but lacks their extraordinary luminosity. Here, we present and discuss the most comprehensive optical data set of this SN to date, comprised of a densely sampled series of early-time spectra obtained within the Nearby Supernova Factory project, plus photometry and spectroscopy obtained at the Very Large Telescope about 1âyr after the explosion. The light curves, colour curves, spectral time series, and ejecta velocities of SN 2012dn are compared with those of other 09dc-like and normal SNe Ia, the overall variety within the class of 09dc-like SNe Ia is discussed, and new criteria for 09dc-likeness are proposed. Particular attention is directed to additional insight that the late-phase data provide. The nebular spectra show forbidden lines of oxygen and calcium, elements that are usually not seen in late-time spectra of SNe Ia, while the ionization state of the emitting iron plasma is low, pointing to low ejecta temperatures and high densities. The optical light curves are characterized by an enhanced fading starting âŒ60âd after maximum and very low luminosities in the nebular phase, which is most readily explained by unusually early formation of clumpy dust in the ejecta. Taken together, these effects suggest a strongly perturbed ejecta density profile, which might lend support to the idea that 09dc-like characteristics arise from a brief episode of interaction with a hydrogen-deficient envelope during the first hours or days after the explosion
SCALA: In situ calibration for integral field spectrographs
International audienceThe scientific yield of current and future optical surveys is increasingly limited by systematic uncertainties in the flux calibration. This is the case for Type Ia supernova (SN Ia) cosmology programs, where an improved calibration directly translates into improved cosmological constraints. Current methodology rests on models of stars. Here we aim to obtain flux calibration that is traceable to state-of-the-art detector-based calibration. We present the SNIFS Calibration Apparatus (SCALA), a color (relative) flux calibration system developed for the SuperNova Integral Field Spectrograph (SNIFS), operating at the University of Hawaii 2.2 m (UH 88) telescope. By comparing the color trend of the illumination generated by SCALA during two commissioning runs, and to previous laboratory measurements, we show that we can determine the light emitted by SCALA with a long-term repeatability better than 1%. We describe the calibration procedure necessary to control for system aging. We present measurements of the SNIFS throughput as estimated by SCALA observations. The SCALA calibration unit is now fully deployed at the UH\,88 telescope, and with it color-calibration between 4000 {\AA} and 9000 {\AA} is stable at the percent level over a one-year baseline
Euthanasia and Physician-Assisted Suicide in Patients with Multiple Geriatric Syndromes
Importance: The Dutch Regional Euthanasia Review Committees (RTEs) reviewed and reported an increasing number of cases of euthanasia and physician-Assisted suicide (EAS) requested by older people with multiple geriatric syndromes (MGS). Knowledge of the characteristics of cases of EAS for MGS is important to facilitate societal debat
On the notion of home and the goals of palliative care
The notion of home is well known from our everyday experience, and plays a crucial role in all kinds of narratives about human life, but is hardly ever systematically dealt with in the philosophy of medicine and health care. This paper is based upon the intuitively positive connotation of the term âhome.â By metaphorically describing the goal of palliative care as âthe patientâs coming home,â it wants to contribute to a medical humanities approach of medicine. It is argued that this metaphor can enrich our understanding of the goals of palliative care and its proper objectives. Four interpretations of âhomeâ and âcoming homeâ are explored: (1) oneâs own house or homelike environment, (2) oneâs own body, (3) the psychosocial environment, and (4) the spiritual dimension, in particular, the origin of human existence. Thinking in terms of coming home implies a normative point of view. It represents central human values and refers not only to the medical-technical and care aspects of health care, but also to the moral context
Dark Energy Survey year 3 results: Constraints on cosmological parameters and galaxy-bias models from galaxy clustering and galaxy-galaxy lensing using the redMaGiC sample
We constrain cosmological parameters and galaxy-bias parameters using the combination of galaxy clustering and galaxy-galaxy lensing measurements from the Dark Energy Survey (DES) year-3 data. We describe our modeling framework and choice of scales analyzed, validating their robustness to theoretical uncertainties in small-scale clustering by analyzing simulated data. Using a linear galaxy-bias model and redMaGiC galaxy sample, we obtain 10% constraints on the matter density of the Universe. We also implement a nonlinear galaxy-bias model to probe smaller scales that includes parametrization based on hybrid perturbation theory and find that it leads to a 17% gain in cosmological constraining power. We perform robustness tests of our methodology pipeline and demonstrate stability of the constraints to changes in the theory model. Using the redMaGiC galaxy sample as foreground lens galaxies and adopting the best-fitting cosmological parameters from DES year-1 data, we find the galaxy clustering and galaxy-galaxy lensing measurements to exhibit significant signals akin to decorrelation between galaxies and mass on large scales, which is not expected in any current models. This likely systematic measurement error biases our constraints on galaxy bias and the S8 parameter. We find that a scale-, redshift-and sky-Area-independent phenomenological decorrelation parameter can effectively capture this inconsistency between the galaxy clustering and galaxy-galaxy lensing. We trace the source of this correlation to a color-dependent photometric issue and minimize its impact on our result by changing the selection criteria of redMaGiC galaxies. Using this new sample, our constraints on the S8 parameter are consistent with previous studies and we find a small shift in the Ïm constraints compared to the fiducial redMaGiC sample. We infer the constraints on the mean host-halo mass of the redMaGiC galaxies in this new sample from the large-scale bias constraints, finding the galaxies occupy halos of mass approximately 1.6Ă10 13 Mâ/h
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