2,465 research outputs found
Taking Pluralism Seriously, or Is the Ethics Manual of the American College of Physicians Unsympathetic to Physicians with Religious Objections to Abortion?
Beyond the Principles of Bioethics: Facing the Consequences of Fundamental Moral Disagreement
Given intractable secular moral pluralism, the force and significance of the four principles (autonomy, beneficence,
non-maleficence, and justice) of Tom Beauchamp and James Childress must be critically re-considered. This essay
examines the history of the articulation of these four principles of bioethics, showing why initially there was an
illusion of a common morality that led many to hold that the principles could give guidance across cultures. But there
is no one sense of the content or the theoretical justification of these principles. In addition, a wide range of secular
moral and bioethical choices has been demoralized into lifestyle choices; the force of the secular moral point of view
has also been deflated, thus compounding moral pluralism. It is the political generation of the principles that provides
a common morality in the sense of an established morality. The principles are best understood as embedded not in a
common morality, sensu stricto, but in that morality that is established at law and public policy in a particular polity.
Although moral pluralism is substantive and intractable at the level of moral content, in a particular polity a
particular morality and a particular bioethics can be established, regarding which health care ethics consultants can
be experts. Public morality and bioethics are at their roots a political reality
Physicians and the Community of Physicians: An Account of Collective Responsibilities
Editor\u27s note: This paper was read at the eighth annual University of Dayton Philosophy Colloquium, held in 1979.
In the course of this paper, I will first present a sketch of some of the cardinal characteristics of professions, as these characteristics bear upon understanding their collective responsibilities. After a brief review of these distinguishing characteristics, I will compare the different senses of obligations that one can attribute to professions and then to their members. I will first examine what is involved in simply being a member of a profession, then a member of a profession within a particular governmental organization (i.e., a state), and finally, the collective responsibility of members of particular professional associations. On the basis of these background reflections, I will proceed to address some particular issues concerning the collective responsibilities of physicians
Radiative transfer modelling of parsec-scale dusty warped discs
Warped discs have been found on (sub-)parsec scale in some nearby Seyfert
nuclei, identified by their maser emission. Using dust radiative transfer
simulations we explore their observational signatures in the infrared in order
to find out whether they can partly replace the molecular torus. Strong
variations of the brightness distributions are found, depending on the
orientation of the warp with respect to the line of sight. Whereas images at
short wavelengths typically show a disc-like and a point source component, the
warp itself only becomes visible at far-infrared wavelengths. A similar variety
is visible in the shapes of the spectral energy distributions. Especially for
close to edge-on views, the models show silicate feature strengths ranging from
deep absorption to strong emission for variations of the lines of sight towards
the warp. To test the applicability of our model, we use the case of the
Circinus galaxy, where infrared interferometry has revealed a highly elongated
emission component matching a warped maser disc in orientation and size. Our
model is for the first time able to present a physical explanation for the
observed dust morphology as coming from the AGN heated dust. As opposed to
available torus models, a warped disc morphology produces a variety of silicate
feature shapes for grazing lines of sight, close to an edge-on view. This could
be an attractive alternative to a claimed change of the dust composition for
the case of the nearby Seyfert 2 galaxy NGC 1068, which harbours a warped maser
disc as well.Comment: accepted by MNRA
Hybrid architecture active wavefront sensing and control system, and method
According to various embodiments, provided herein is an optical system and method that can be configured to perform image analysis. The optical system can comprise a telescope assembly and one or more hybrid instruments. The one or more hybrid instruments can be configured to receive image data from the telescope assembly and perform a fine guidance operation and a wavefront sensing operation, simultaneously, on the image data received from the telescope assembly
Dust emission from a parsec-scale structure in the Seyfert 1 nucleus of NGC 4151
We report mid-IR interferometric measurements with \sim 10 mas resolution,
which resolve the warm (T = 285 +25 / -50 K) thermal emission at the center of
NGC 4151. Using pairs of VLT 8.2 m telescopes with MIDI and by comparing the
data to a Gaussian model, we determined the diameter of the dust emission
region, albeit only along one position angle, to be 2.0 +/- 0.4 pc (FWHM). This
is the first size and temperature estimate for the nuclear warm dust
distribution in a Seyfert 1 galaxy. The parameters found are comparable to
those in Seyfert 2 galaxies, thus providing direct support for the unified
model. Using simple analytic temperature distributions, we find that the
mid-infrared emission is probably not the smooth continuation of the hot
nuclear source that is marginally resolved with K band interferometry. We also
detected weak excess emission around 10.5 micron in our shorter baseline
observation, possibly indicating that silicate emission is extended to the
parsec scale.Comment: 5 pages, 4 figures, accepted for publication in The Astrophysical
Journal Letter
Linear and nonlinear waveguides induced by optical vortex solitons
We study, numerically and analytically, linear and nonlinear waveguides
induced by optical vortex solitons in a Kerr medium. Both fundamental and
first-order guided modes are analyzed, as well as the cases of effectively
defocusing and focusing nonlinearity.Comment: 3 pages, 3 figures, changed conten
An analysis method for time ordered data processing of Dark Matter experiments
The analysis of the time ordered data of Dark Matter experiments is becoming
more and more challenging with the increase of sensitivity in the ongoing and
forthcoming projects. Combined with the well-known level of background events,
this leads to a rather high level of pile-up in the data. Ionization,
scintillation as well as bolometric signals present common features in their
acquisition timeline: low frequency baselines, random gaussian noise, parasitic
noise and signal characterized by well-defined peaks. In particular, in the
case of long-lasting signals such as bolometric ones, the pile-up of events may
lead to an inaccurate reconstruction of the physical signal (misidentification
as well as fake events). We present a general method to detect and extract
signals in noisy data with a high pile-up rate and qe show that events from few
keV to hundreds of keV can be reconstructed in time ordered data presenting a
high pile-up rate. This method is based on an iterative detection and fitting
procedure combined with prior wavelet-based denoising of the data and baseline
subtraction. {We have tested this method on simulated data of the MACHe3
prototype experiment and shown that the iterative fitting procedure allows us
to recover the lowest energy events, of the order of a few keV, in the presence
of background signals from a few to hundreds of keV. Finally we applied this
method to the recent MACHe3 data to successfully measure the spectrum of
conversion electrons from Co57 source and also the spectrum of the background
cosmic muons
VLTI/AMBER observations of the Seyfert nucleus of NGC 3783
Context. The putative tori surrounding the accretion disks of active galactic
nuclei (AGNs) play a fundamental role in the unification scheme of AGNs.
Infrared long-baseline interferometry allows us to study the inner dust
distribution in AGNs with unprecedented spatial resolution over a wide infrared
wavelength range.
Aims. Near- and mid-infrared interferometry is used to investigate the
milli-arcsecond-scale dust distribution in the type 1.5 Seyfert nucleus of NGC
3783.
Methods. We observed NGC 3783 with the VLTI/AMBER instrument in the K-band
and compared our observations with models.
Results. From the K-band observations, we derive a ring-fit torus radius of
0.74 +/- 0.23 mas or 0.16 +/- 0.05 pc. We compare this size with infrared
interferometric observations of other AGNs and UV/optical-infrared
reverberation measurements. For the interpretation of our observations, we
simultaneously model our near- and mid-infrared visibilities and the SED with a
temperature/density-gradient model including an additional inner hot 1400 K
ring component
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