6,164 research outputs found
Ethical Challenges and Opportunities at the Edge: Incorporating Spirituality and Religion Into Psychotherapy
Incorporating spirituality and religion into psychotherapy has been controversial, but recent contributions have argued the importance and provided foundations for doing so. Discussions of ethical challenges in this process are emerging, and this contribution discusses several preliminary issues, relying on the Resolution on Religious, Religion-Based and/or Religion-Derived Prejudice adopted by the American Psychological Association in 2007, as guidance when used with the American Psychological Association’s (2002) Ethical Principles of Psychologists and Code of Conduct. Specifically, this discussion of preliminary challenges addresses competence, bias, maintaining traditions and standards of psychology, and integrity in labeling services for reimbursement. Commentators deepen the discussion, addressing what constitutes minimal competence in this area; effective and truly mutual collaboration with clergy; the high level of ethical complexity and “inherent messiness” of this domain of psychological practice; and the particular challenges of demarcating the boundaries of these domains for regulatory and billing purposes. This discussion offers decidedly preliminary ideas on managing the interface of these domains. Further development is needed before this nascent area approximates precise guidelines or standards
Modeling payback from research into the efficacy of left-ventricular assist devices as destination therapy
Objectives: Ongoing developments in design have improved the outlook for left-ventricular assist device (LVAD) implantation as a therapy in end-stage heart failure. Nevertheless, early cost-effectiveness assessments, based on first-generation devices, have not been encouraging. Against this background, we set out (i) to examine the survival benefit that LVADs would need to generate before they could be deemed cost-effective; (ii) to provide insight into the likelihood that this benefit will be achieved; and (iii) from the perspective of a healthcare provider, to assess the value of discovering the actual size of this benefit by means of a Bayesian value of information analysis.
Methods: Cost-effectiveness assessments are made from the perspective of the healthcare provider, using current UK norms for the value of a quality-adjusted life-year (QALY). The treatment model is grounded in published analyses of the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) trial of first-generation LVADs, translated into a UK cost setting. The prospects for patient survival with second-generation devices is assessed using Bayesian prior distributions, elicited from a group of leading clinicians in the field.
Results: Using established thresholds, cost-effectiveness probabilities under these priors are found to be low (.2 percent) for devices costing as much as £60,000. Sensitivity of the conclusions to both device cost and QALY valuation is examined.
Conclusions: In the event that the price of the device in use would reduce to £40,000, the value of the survival information can readily justify investment in further trials
Unification of Luminous Type 1 Quasars through CIV Emission
Using a sample of 30,000 quasars from SDSS-DR7, we explore the range of
properties exhibited by high-ionization, broad emission lines, such as CIV
1549. Specifically we investigate the anti-correlation between L_UV and
emission line EQW (the Baldwin Effect) and the "blueshifting" of
high-ionization emission lines. The blueshift of the CIV emission line is
nearly ubiquitous, with a mean shift of 810 km/s for radio-quiet (RQ) quasars
and 360 km/s for radio-loud (RL) quasars, and the Baldwin Effect is present in
both RQ and RL samples. Composite spectra are constructed as a function of CIV
emission line properties in attempt to reveal empirical relationships between
different line species and the SED. Within a two-component disk+wind model of
the broad emission line region (BELR), where the wind filters the continuum
seen by the disk component, we find that RL quasars are consistent with being
dominated by the disk component, while BALQSOs are consistent with being
dominated by the wind component. Some RQ objects have emission line features
similar to RL quasars; they may simply have insufficient black hole (BH) spin
to form radio jets. Our results suggest that there could be significant
systematic errors in the determination of L_bol and BH mass that make it
difficult to place these findings in a more physical context. However, it is
possible to classify quasars in a paradigm where the diversity of BELR
parameters are due to differences in an accretion disk wind between quasars
(and over time); these differences are underlain primarily by the SED, which
ultimately must be tied to BH mass and accretion rate.Comment: 51 pages, 18 figures, accepted by AJ, revised version includes
various modifications based on the referee's comment
CIV Emission and the Ultraviolet through X-ray Spectral Energy Distribution of Radio-Quiet Quasars
In the restframe UV, two of the parameters that best characterize the range
of emission-line properties in quasar broad emission-line regions are the
equivalent width and the blueshift of the CIV line relative to the quasar rest
frame. We explore the connection between these emission-line properties and the
UV through X-ray spectral energy distribution (SED) for radio-quiet (RQ)
quasars. Our sample consists of a heterogeneous compilation of 406 quasars from
the Sloan Digital Sky Survey and Palomar-Green survey that have well-measured
CIV emission-line and X-ray properties (including 164 objects with measured
Gamma). We find that RQ quasars with both strong CIV emission and small CIV
blueshifts can be classified as "hard-spectrum" sources that are (relatively)
strong in the X-ray as compared to the UV. On the other hand, RQ quasars with
both weak CIV emission and large CIV blueshifts are instead "soft-spectrum"
sources that are (relatively) weak in the X-ray as compared to the UV. This
work helps to further bridge optical/soft X-ray "Eigenvector 1" relationships
to the UV and hard X-ray. Based on these findings, we argue that future work
should consider systematic errors in bolometric corrections (and thus accretion
rates) that are derived from a single mean SED. Detailed analysis of the CIV
emission line may allow for SED-dependent corrections to these quantities.Comment: AJ, in press; 39 pages, 11 figures, 3 table
The SAMI Galaxy Survey: gravitational potential and surface density drive stellar populations -- I. early-type galaxies
The well-established correlations between the mass of a galaxy and the
properties of its stars are considered evidence for mass driving the evolution
of the stellar population. However, for early-type galaxies (ETGs), we find
that color and stellar metallicity [Z/H] correlate more strongly with
gravitational potential than with mass , whereas stellar population
age correlates best with surface density . Specifically, for our sample
of 625 ETGs with integral-field spectroscopy from the SAMI Galaxy Survey,
compared to correlations with mass, the color--, [Z/H]--, and
age-- relations show both smaller scatter and less residual trend with
galaxy size. For the star formation duration proxy [/Fe], we find
comparable results for trends with and , with both being
significantly stronger than the [/Fe]- relation. In determining the
strength of a trend, we analyze both the overall scatter, and the observational
uncertainty on the parameters, in order to compare the intrinsic scatter in
each correlation. These results lead us to the following inferences and
interpretations: (1) the color-- diagram is a more precise tool for
determining the developmental stage of the stellar population than the
conventional color--mass diagram; and (2) gravitational potential is the
primary regulator of global stellar metallicity, via its relation to the gas
escape velocity. Furthermore, we propose the following two mechanisms for the
age and [/Fe] relations with : (a) the age-- and
[/Fe]-- correlations arise as results of compactness driven
quenching mechanisms; and/or (b) as fossil records of the
relation in their disk-dominated progenitors.Comment: 9 pages, 4 figures, 1 table Accepted to Ap
High-Redshift SDSS Quasars with Weak Emission Lines
We identify a sample of 74 high-redshift quasars (z>3) with weak emission
lines from the Fifth Data Release of the Sloan Digital Sky Survey and present
infrared, optical, and radio observations of a subsample of four objects at
z>4. These weak emission-line quasars (WLQs) constitute a prominent tail of the
Lya+NV equivalent width distribution, and we compare them to quasars with more
typical emission-line properties and to low-redshift active galactic nuclei
with weak/absent emission lines, namely BL Lac objects. We find that WLQs
exhibit hot (T~1000 K) thermal dust emission and have rest-frame 0.1-5 micron
spectral energy distributions that are quite similar to those of normal
quasars. The variability, polarization, and radio properties of WLQs are also
different from those of BL Lacs, making continuum boosting by a relativistic
jet an unlikely physical interpretation. The most probable scenario for WLQs
involves broad-line region properties that are physically distinct from those
of normal quasars.Comment: Updated to match version published in ApJ. 20 pages, 12 figure
Limits on Arcminute Scale Cosmic Microwave Background Anisotropy with the BIMA Array
We have used the Berkeley-Illinois-Maryland-Association (BIMA) millimeter
array outfitted with sensitive cm-wave receivers to search for Cosmic Microwave
Background (CMB) anisotropies on arcminute scales. The interferometer was
placed in a compact configuration which produces high brightness sensitivity,
while providing discrimination against point sources. Operating at a frequency
of 28.5 GHz, the FWHM primary beam of the instrument is 6.6 arcminutes. We have
made sensitive images of seven fields, five of which where chosen specifically
to have low IR dust contrast and be free of bright radio sources. Additional
observations with the Owens Valley Radio Observatory (OVRO) millimeter array
were used to assist in the location and removal of radio point sources.
Applying a Bayesian analysis to the raw visibility data, we place limits on CMB
anisotropy flat-band power Q_flat = 5.6 (+3.0 -5.6) uK and Q_flat < 14.1 uK at
68% and 95% confidence. The sensitivity of this experiment to flat band power
peaks at a multipole of l = 5470, which corresponds to an angular scale of
approximately 2 arcminutes. The most likely value of Q_flat is similar to the
level of the expected secondary anisotropies.Comment: 15 pages, 5 figures, LaTex, aas2pp4.sty, ApJ submitte
X-ray and Multiwavelength Insights into the Nature of Weak Emission-Line Quasars at Low Redshift
(Abridged) We report on the X-ray and multiwavelength properties of 11
radio-quiet quasars with weak or no emission lines identified by the Sloan
Digital Sky Survey (SDSS) with redshift z=0.4-2.5. The distribution of relative
X-ray brightness for our low-redshift weak-line quasar (WLQ) candidates is
significantly different from that of typical radio-quiet quasars, having an
excess of X-ray weak sources, but it is consistent with that of high-redshift
WLQs. The X-ray weak sources generally show similar UV emission-line properties
to those of the X-ray weak quasar PHL 1811; they may belong to the notable
class of PHL 1811 analogs. The average X-ray spectrum of these sources is
somewhat harder than that of typical radio-quiet quasars. Several other
low-redshift WLQ candidates have normal ratios of X-ray-to-optical/UV flux, and
their average X-ray spectral properties are also similar to those of typical
radio-quiet quasars. The X-ray weak and X-ray normal WLQ candidates may belong
to the same subset of quasars having high-ionization "shielding gas" covering
most of the wind-dominated broad emission-line region, but be viewed at
different inclinations. The mid-infrared-to-X-ray spectral energy distributions
(SEDs) of these sources are generally consistent with those of typical SDSS
quasars, showing that they are not likely to be BL Lac objects with
relativistically boosted continua and diluted emission lines. However, one
source in our X-ray observed sample is remarkably strong in X-rays, indicating
that a small fraction of low-redshift WLQ candidates may actually be BL Lacs
residing in the radio-faint tail of the BL Lac population. We also investigate
universal selection criteria for WLQs over a wide range of redshift, finding
that it is not possible to select WLQ candidates in a fully consistent way
using different prominent emission lines as a function of redshift.Comment: ApJ in press; 26 pages, 11 figures and 7 tables. The full Table 3 is
available upon reques
Observations of the Cosmic Microwave Background and Implications for Cosmology and Large Scale Structure
Observations of the Cosmic Microwave Background (CMB) are discussed, with
particular emphasis on current ground-based experiments and on future
satellite, balloon and interferometer experiments. Observational techniques and
the effects of contaminating foregrounds are highlighted. Recent CMB data is
used with large scale structure (LSS) data to constrain cosmological parameters
and the complementary nature of CMB, LSS and supernova distance data is
emphasized.Comment: 23 pages, 10 figures. Phil. Trans. R. Soc. Lond. A., 1998, in pres
Understanding the nature of the optically faint radio sources and their connection to the submillimeter population
We present a sample of 43 submillimeter sources detected (at >3 sigma), drawn
from our program to follow-up optically faint radio sources with SCUBA. These
sources already have associated radio and in many cases optical
identifications, and many are also detected at 450 microns. We compare these
with 12 submillimeter sources drawn from the literature, which were discovered
in blank field mapping campaigns, but also have radio detections. We then use
this total sample (55 sources) to study and model the evolution of dusty
galaxies. A correlation is observed in the sub-mm/radio color-magnitude
diagram, which can be modeled by strong luminosity evolution. The selection
effects of the radio/optical pre-selection technique are determined from the
models, and a corrected redshift distribution is constrained using a range of
model assumptions. The temperature/redshift effects on the 450 microns detected
subset of our sample are studied in relation to the models, and prospects for
improved measurements in the shorter sub-mm wavelength windows (450 microns and
350 microns) are explored.Comment: to appear in ApJ, 19 pages, 9 figure
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