6,870 research outputs found
On becoming a supervisor: an anticipated transition for trainee clinical psychologists
Section A reviews the empirical and theoretical literature on supervision in order to gain a better understanding of how experiences of supervision during clinical training may relate to the anticipated transition of ‘becoming a supervisor’.
Section B presents an initial exploratory study focusing on how trainee clinical psychologists make sense of their experiences of supervision in relation to the anticipated transition of ‘becoming a supervisor’. Semi-structured interviews were conducted with ten trainee clinical psychologists at the end of their training. Data was analysed using Interpretative Phenomenological Analysis. Analysis of the transcripts revealed three master themes: the development of the professional self; the supervisory relationship; and the development of supervisory perspectives. Developmental and relational aspects of supervision were emphasised in relation to the anticipated transition of ‘becoming a supervisor’, alongside the significance of the supervisor as a role model. Learning from peers’ experiences of supervision was also key. The study concluded that participants’ experiences of supervision and the meaning they give to those in relation to the anticipated transition of ‘becoming a supervisor’ were connected to the development of a professional self in which increasing autonomy and integration of the personal self was important. Learning took place in the context of the supervisory relationship. The human side of that relationship was valued where reciprocity and containment facilitated a safe space to explore. The development of supervisory perspectives facilitated the anticipated transition of ‘becoming a supervisor’ as experiences of supervision helped to evaluate positive and negative aspects of that role. Subsequently, an ‘ideal for self’ emerged
Signatures of multiple stellar populations in unresolved extragalactic globular/ young massive star clusters
We present an investigation of potential signatures of the formation of
multiple stellar populations in recently formed extragalactic star clusters.
All of the Galactic globular clusters for which good samples of individual
stellar abundances are available show evidence for multiple populations. This
appears to require that multiple episodes of star formation and light element
enrichment are the norm in the history of a globular cluster. We show that
there are detectable observational signatures of multiple formation events in
the unresolved spectra of massive, young extragalactic star clusters. We
present the results of a pilot program to search for one of the cleanest
signatures that we identify - the combined presence of emission lines from a
very recently formed population and absorption lines from a somewhat older
population. A possible example of such a system is identified in the Antennae
galaxies. This source's spectrum shows evidence of two stellar populations with
ages of 8 Myr and 80 Myr. Further investigation shows that these populations
are in fact physically separated, but only by a projected distance of 59 pc. We
show that the clusters are consistent with being bound and discuss the
possibility that their coalescence could result in a single globular cluster
hosting multiple stellar populations. While not the prototypical system
proposed by most theories of the formation of multiple populations in clusters,
the detection of this system in a small sample is both encouraging and
interesting. Our investigation suggests that expanded surveys of massive young
star clusters should detect more clusters with such signatures.Comment: 11 pages, 7 figures: accepted for publication in Ap
Measuring the cosmological constant with redshift surveys
It has been proposed that the cosmological constant might be
measured from geometric effects on large-scale structure. A positive vacuum
density leads to correlation-function contours which are squashed in the radial
direction when calculated assuming a matter-dominated model. We show that this
effect will be somewhat harder to detect than previous calculations have
suggested: the squashing factor is likely to be , given realistic
constraints on the matter contribution to . Moreover, the geometrical
distortion risks being confused with the redshift-space distortions caused by
the peculiar velocities associated with the growth of galaxy clustering. These
depend on the density and bias parameters via the combination , and we show that the main practical effect of a geometrical
flattening factor is to simulate gravitational instability with . Nevertheless, with datasets of sufficient size it is
possible to distinguish the two effects; we discuss in detail how this should
be done. New-generation redshift surveys of galaxies and quasars are
potentially capable of detecting a non-zero vacuum density, if it exists at a
cosmologically interesting level.Comment: MNRAS in press. 12 pages LaTeX including Postscript figures. Uses
mn.sty and epsf.st
A Model for Structure Formation Seeded by Gravitationally Produced Matter
This model assumes the baryons, radiation, three families of massless
neutrinos, and cold dark matter were mutually thermalized before the baryon
number was fixed, primeval curvature fluctuations were subdominant, and
homogeneity was broken by scale-invariant fluctuations in a new dark matter
component that behaves like a relativistic ideal fluid. The fluid behavior
could follow if this new component were a single scalar field that interacts
only with gravity and with itself by a pure quartic potential. The initial
energy distribution could follow if this component were gravitationally
produced by inflation. The power spectra of the present distributions of mass
and radiation in this model are not inconsistent with the measurements but are
sufficiently different from the adiabatic cold dark matter model to allow a
sharp test in the near future.Comment: 4 pages, 2 figures submitted to ApJ Letter
Limits on [OIII] 5007 emission from NGC4472's globular clusters: constraints on planetary nebulae and ultraluminous black hole X-ray binaries in globular clusters
We have searched for [OIII] 5007 emission in high resolution spectroscopic
data from Flames/Giraffe VLT observations of 174 massive globular clusters
(GCs) in NGC4472. No planetary nebulae (PNe) are observed in these clusters,
constraining the number of PNe per bolometric luminosity,
\alpha<0.8*10^{-7}PN/L_{\odot}. This is significantly lower than the rate
predicted from stellar evolution, if all stars produce PNe. Comparing our
results to populations of PNe in galaxies, we find most galaxies have a higher
\alpha than these GCs (more PNe per bolometric luminosity - though some massive
early-type galaxies do have similarly low \alpha). The low \alpha required in
these GCs suggests that the number of PNe per bolometric luminosity does not
increase strongly with decreasing mass or metallicity of the stellar
population. We find no evidence for correlations between the presence of known
GC PNe and either the presence of low mass X-ray binaries (LMXBs) or the
stellar interaction rates in the GCs. This, and the low \alpha observed,
suggests that the formation of PNe may not be enhanced in tight binary systems.
These data do identify one [OIII] emission feature, this is the (previously
published) broad [OIII] emission from the cluster RZ 2109. This emission is
thought to originate from the LMXB in this cluster, which is accreting at
super-Eddington rates. The absence of any similar [OIII] emission from the
other clusters favors the hypothesis that this source is a black hole LMXB,
rather than a neutron star LMXB with significant geometric beaming of its X-ray
emission.Comment: 10 pages, 3 figures, accepted for publication in Ap
FINANCIAL PROSPECTS, BUSINESS ORGANIZATION, AND MANAGEMENT: FARM BUSINESS CHALLENGES
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Strong lensing time delay: a new way of measuring cosmic shear
The phenomenon of cosmic shear, or distortion of images of distant sources
unaccompanied by magnification, is an effective way of probing the content and
state of the foreground Universe, because light rays do not have to pass
through mass structures in order to be sheared. It is shown that the delay in
the arrival times between two simultaneously emitted photons that appear to be
arriving from a pair of images of a strongly lensed cosmological source
contains not only information about the Hubble constant, but also the long
range gravitational effect of galactic scale mass clumps located away from the
light paths in question. This is therefore also a method of detecting shear.
Data on time delays among a sample of strongly lensed sources can provide
crucial information about whether extra dynamics beyond gravity and dark energy
are responsible for the global flatness of space. If the standard
model is correct, there should be a large dispersion in the value of as
inferred from the delay data by (the usual procedure of) ignoring the effect of
all other mass clumps except the strong lens itself. The fact that there has
not been any report of a significant deviation from the 0.7 mark during
any of the determinations by this technique may already be pointing to
the absence of the random effect discussed here.Comment: ApJ in pres
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