3,557 research outputs found
A case of episcleral tattooing – an emerging body modification trend
In 2007 an article was published describing the first forays into the practice of episcleral tattooing. Currently only a handful of people worldwide have undergone this procedure, whereby a needle is used to inject dye under the bulbar conjunctiva. To date there have been no previous reports of the risks and complications of this emerging practice in the medical literature. We present a case involving a complication that arose in one of the few people in Britain to have undergone episcleral tattooing for cosmetic purposes
Forecasting Methods for Marketing: Review of Empirical Research
This paper reviews the empirical research on forecasting in marketing. In addition, it presents results from some small scale surveys. We offer a framework for discussing forecasts in the area of marketing,and then review the literature in light of that framework. Particular emphasis is given to a pragmatic interpretation of the literature and findings. Suggestions are made on what research is needed
Patterns of Duality in N=1 SUSY Gauge Theories
We study the patterns in the duality of a wide class of N=1 supersymmetric
gauge theories in four dimensions. We present many new generalizations of the
classic duality models of Kutasov and Schwimmer, which have themselves been
generalized numerous times in works of Intriligator, Leigh and the present
authors. All of these models contain one or two fields in a two-index tensor
representation, along with fields in the defining representation. The
superpotential for the two-index tensor(s) resembles A_k or D_k singularity
forms, generalized from numbers to matrices. Looking at the ensemble of these
models, classifying them by superpotential, gauge group, and ``level'' -- for
terminology we appeal to the architecture of a typical European-style theatre
-- we identify emerging patterns and note numerous interesting puzzles.Comment: 34 pages, 4 figures, uses harvmac and table
Globular Clusters in the dE,N galaxy NGC 3115 DW1: New Insights from Spectroscopy and HST Photometry
The properties of globular clusters in dwarf galaxies are key to
understanding the formation of globular cluster systems, and in particular in
verifying scenarios in which globular cluster systems of larger galaxies formed
(at least partly) from the accretion of dwarf galaxies. Here, we revisit the
globular cluster system of the dE,N galaxy NGC 3115 DW1 - a companion of the
nearby S0 galaxy NGC 3115 - adding Keck/LRIS spectroscopy and HST/WFPC2 imaging
to previous ground-based photometry. Spectra for seven globular clusters reveal
normal abundance ratios with respect to the Milky Way and M31 clusters, as well
as a relatively high mean metallicity ([Fe/H] = -1.0+/-0.1 dex). Crude
kinematics indicate a high velocity dispersion within 10 kpc which could either
be caused by dark matter dominated outer regions, or by the stripping of outer
globular clusters by the nearby giant galaxy NGC 3115. The total galaxy mass
out to 3 and 10 kpc lies between 10^10 and 10^11 solar masses and 2*10^10 and
4*10^11 solar masses, respectively, depending on the mass estimator used and
the assumptions on cluster orbits and systemic velocity. The HST imaging allows
measurement of sizes for two clusters, returning core radii around 2.0 pc,
similar to the sizes observed in other galaxies. Spectroscopy allows an
estimate of the degree of contamination by foreground stars or background
galaxies for the previous ground-based photometry, but does not require a
revision of previous results: NGC 3115 DW1 hosts around 60+/-20 clusters which
corresponds to a specific frequency of 4.9+/-1.9, on the high end for massive
dEs. Given its absolute magnitude (M_V=-17.7 mag) and the properties of its
cluster system, NGC 3115 DW1 appears to be a transition between a luminous dE
and low-luminosity E galaxy.Comment: 25 pages, 8 figures, accepted for publication in The Astronomical
Journal, August 2000 issu
Extragalactic Globular Clusters in the Near-Infrared II. The Globular Clusters Systems of NGC 3115 and NGC 4365
We combine near-infrared photometry obtained with the VLT/ISAAC instrument
and archival HST/WFPC2 optical images to determine VIK magnitudes and colours
of globular clusters in two early-type galaxies, NGC 3115 and NGC 4365. The
combination of near-IR and optical photometry provides a way to lift the
age-metallicity degeneracy. For NGC 3115, the globular cluster colours reveal
two major sub-populations, consistent with previous studies. By comparing the
V-I, V-K colours of the NGC 3115 globular clusters with SSP models, we find
that the colour difference between the two >10 Gyr old major sub-populations is
primarily due to a difference in metallicity. We find \Delta[Fe/H] = 1.0 +/-
0.3 dex and the blue and red globular cluster sub-populations being coeval
within 3 Gyr. In contrast to the NGC 3115 globular clusters, the globular
cluster system in NGC 4365 exhibits a more complex age and metallicity
structure. We find a significant population of intermediate-age very metal-rich
globular clusters along with an old population of both metal-rich and
metal-poor clusters. Specifically, we observe a large population of globular
clusters with V-K and V-I colours, for which all current SSP models give ages
and metallicities in the range ~2-8 Gyr and ~0.5-3 Z_solar, respectively. After
10 Gyr of passive evolution, the intermediate-age globular clusters in NGC 4365
will have colours which are consistent with the very metal-rich population of
globular clusters in giant elliptical galaxies, such as M87. Our results for
both globular cluster systems are consistent with previous age and metallicity
studies of the diffuse galactic light. In addition to the major globular
cluster populations in NGC 3115 and NGC 4365 we report on the detection of
objects with extremely red colours.Comment: accepted for publication in A&A, 19 pages, incl. 9 figure
The True NTH prostate cancer survivorship care programme: development and evaluation of a model for delivering follow up care to men with prostate cancer
42 Background: Increasing use of prostate specific antigen (PSA), improvements in treatment and aging population have led to the escalating incidence of prostate cancer. 5 year survival rate is relatively high and men who have completed treatment require long-term follow-up to detect recurrence or progression of disease, monitor adverse effects of treatment and identify and address psychosocial needs. Studies demonstrate men have a range of unmet physical and psychosocial needs, and health services are struggling to cope with the growing numbers. Changes is critical for long-term sustainability of the health system in many developed nations Methods: This presentation presents a model of follow up care centered on remote surveillance of PSA combined with promoting patient self-management. This initiative is part of the True NTH programme of developments initiated in the UK with funding from Movember Foundation and Prostate Cancer UK. Traditional face to face clinic follow up consultations are replaced with: patient directed individually tailored care and surveillance programme which involves: a 4 hour preparatory patient workshop, remote assessment of unmet needs and symptoms and surveillance of PSA, patient information resources, survivorship care plan, communication of treatment summary and management plan to primary care, and rapid recall system for assessment in secondary care should the need arise. The care programme is mediated through clinician and patient access to an IT portal enabling communication. Results: The second part of the presentation will describe the evaluation protocol. A historical cohort design is comparing a group of men receiving clinic follow up care (N = 300) with men enrolled on the care programme (N = 300) in 3 centers. Patient-reported outcomes are collected at baseline, 4 months and 8 months. Health economic evaluation will compare costs of clinic based follow up with those of the care programme from both a health service and patient perspective. Conclusions: The evaluation will generate data on impact, acceptability and cost of this model of follow-up care. </jats:p
An HST/WFPC2 survey of bright young clusters in M31. I. VdB0, a massive star cluster seen at t ≃ 25 Myr
Aims. We introduce our imaging survey of possible young massive globular clusters in M31 performed with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope (HST). We obtained shallow (to B ~ 25) photometry of individual stars in 20 candidate clusters. We present here details of the data reduction pipeline that is being applied to all the survey data and describe its application to the brightest among our targets, van den Bergh 0 (VdB0), taken as a test case.
Methods. Point spread function fitting photometry of individual stars was obtained for all the WFPC2 images of VdB0 and the completeness of the final samples was estimated using an extensive set of artificial stars experiments. The reddening, the age and the metallicity of the cluster were estimated by comparing the observed color magnitude diagram (CMD) with theoretical isochrones. Structural parameters were obtained from model-fitting to the intensity profiles measured within circular apertures on the WFPC2 images.
Results. Under the most conservative assumptions, the stellar mass of VdB0 is M> 2.4 x 10^4 M_☉ , but our best estimates lie in the range ≃4-9 x 10^4 M_☉. The CMD of VdB0 is best reproduced by models having solar metallicity and age ≃25 Myr. Ages less than ≃12 Myr and greater than ≃60 Myr are clearly ruled out by the available data. The cluster has a remarkable number of red super giants (≳18) and a CMD very similar to Large Magellanic Cloud clusters usually classified as young globulars such as NGC 1850, for example.
Conclusions. VdB0 is significantly brighter (≳1 mag) than Galactic open clusters of similar age. Its present-day mass and half-light radius ((r_h = 7.4 pc) are more typical of faint globular clusters than of open clusters. However, given its position within the disk of M31, it is expected to be destroyed by dynamical effects, in particular by encounters with giant molecular clouds, within the next ~4 Gyr
The Globular Cluster System of the Virgo Dwarf Elliptical Galaxy VCC 1087
We have analysed the globular cluster (GC) system of the nucleated dwarf
elliptical galaxy VCC 1087 in the Virgo cluster, based on Keck/LRIS
spectroscopy and archival HST/ACS imaging. We estimate VCC 1087 hosts a total
population of 77+/-19 GCs, which corresponds to a relatively high V-band
specific frequency of 5.8+/-1.4. The g-z color distribution of the GCs shows a
blue (metal-poor) peak with a tail of redder (metal-rich) clusters similar in
color to those seen in luminous ellipticals. Spectroscopy of a subsample of 12
GCs suggests that the GC system is old and coeval (~10 Gyr), with a fairly
broad metallicity distribution (-1.8<[m/H]<-0.8). In contrast, an integrated
spectrum of the underlying galaxy starlight reveals that its optical luminosity
is dominated by metal-rich, intermediate-aged stars. Radial velocities of the
GCs suggest rotation close to the major axis of the galaxy, and this rotation
is dynamically significant with (v/sigma)^* >1. A compilation of the kinematics
of the GC systems of 9 early-type galaxies shows surprising diversity in the
v/sigma parameter for GC systems. In this context, the GC system of VCC 1087
exhibits the most significant rotation to velocity dispersion signature.
Modeling the velocity dispersion profile of the GCs and galaxy stars suggest
fairly constant mass-to-light ratios of ~3 out to 6.5 kpc. The present
observations can entertain both baryonic and non-baryonic solutions, and GC
velocities at larger radii would be most valuable with regard to this issue. We
discuss the evolution of VCC 1087 in terms of the galaxy ``harassment''
scenario, and conclude that this galaxy may well be the remains of a faded,
tidally perturbed Sc spiral [abridged].Comment: 17 pages, 13 figures, to appear in the A
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