4,816 research outputs found
NICMOS Observations of Low-Redshift Quasar Host Galaxies
We have obtained Near-Infrared Camera and Multi-Object Spectrometer images of
16 radio quiet quasars observed as part of a project to investigate the
``luminosity/host-mass limit.'' The limit results were presented in McLeod,
Rieke, & Storrie-Lombardi (1999). In this paper, we present the images
themselves, along with 1- and 2-dimensional analyses of the host galaxy
properties. We find that our model-independent 1D technique is reliable for use
on ground-based data at low redshifts; that many radio-quiet quasars live in
deVaucouleurs-law hosts, although some of the techniques used to determine host
type are questionable; that complex structure is found in many of the hosts,
but that there are some hosts that are very smooth and symmetric; and that the
nuclei radiate at ~2-20% of the Eddington rate based on the assumption that all
galaxies have central black holes with a constant mass fraction of 0.6%.
Despite targeting hard-to-resolve hosts, we have failed to find any that imply
super-Eddington accretion rates.Comment: To appear in ApJ, 28 pages including degraded figures. Download the
paper with full-resolutio figures from
http://www.astro.wellesley.edu/kmcleod/mm.p
Acceptance and commitment therapy delivered in a dyad after a severe traumatic brain injury: a feasibility study
Objective:
There is a high prevalence of complex psychological distress after a traumatic brain injury but limited evidence of effective interventions. We examined the feasibility of Acceptance and Commitment Therapy after a severe traumatic brain injury using the criteria, investigating a therapeutic effect, and reviewing the acceptability of measures, treatment protocol, and delivery method (in a dyad of two clients and a therapist).
Method:
Two male outpatients with severe traumatic brain injury and associated psychological distress jointly engaged in a seven session treatment program based on Acceptance and Commitment Therapy principles. Pre- and post-treatment measures of mood, psychological flexibility, and participation were taken in addition to weekly measures.
Results:
The intervention showed a therapeutic effect with one participant, and appeared to be acceptable for both participants with regard to program content, measures, and delivery mode by in a dyad. One participant showed both significant clinical and reliable change across several outcome measures including measures of mood and psychological flexibility. The second participant did not show a reduction in psychological inflexibility, but did show a significant drop in negative affect. Significant changes pre- to post-treatment for measures of participation were not indicated. Qualitatively, both participants engaged in committed action set in accordance with their values.
Conclusions:
This study suggests that Acceptance and Commitment Therapy may be feasible to be delivered in a dyad with individuals who have a severe traumatic brain injury. A further test of its potential efficacy in a phase II clinical trial is recommended
Unicyclic Components in Random Graphs
The distribution of unicyclic components in a random graph is obtained
analytically. The number of unicyclic components of a given size approaches a
self-similar form in the vicinity of the gelation transition. At the gelation
point, this distribution decays algebraically, U_k ~ 1/(4k) for k>>1. As a
result, the total number of unicyclic components grows logarithmically with the
system size.Comment: 4 pages, 2 figure
Structure of solutions of the Skyrme model on three-sphere. Numerical results
The hedgehog Skyrme model on three-sphere admits very rich spectrum of
solitonic solutions which can be encompassed by a strikingly simple scheme. The
main result of this paper is the statement of the tripartite structure of
solutions of the model and the discovery in what configurations these solutions
appear. The model contains features of more complicated models in General
Relativity and as such can give insight into them.Comment: 20 pages, 13 figures in, with emai
On asymptotic stability of the Skyrmion
We study the asymptotic behavior of spherically symmetric solutions in the
Skyrme model. We show that the relaxation to the degree-one soliton (called the
Skyrmion) has a universal form of a superposition of two effects: exponentially
damped oscillations (the quasinormal ringing) and a power law decay (the tail).
The quasinormal ringing, which dominates the dynamics for intermediate times,
is a linear resonance effect. In contrast, the polynomial tail, which becomes
uncovered at late times, is shown to be a \emph{nonlinear} phenomenon.Comment: 4 pages, 4 figures, minor changes to match the PRD versio
Carer burden and stigma in schizophrenia and affective disorders: experiences from Sri Lanka
Objectives:
Stigma compounds the burden experienced by family members of those with a mental illness. This study aimed to examine burden experienced by carers of people with schizophrenia or affective disorders and to explore the relationship between carer burden and stigma.
Method:
A cross sectional descriptive study was conducted with patient-carer dyads involving 67 patients diagnosed with schizophrenia and 51 diagnosed with affective disorder. Carers completed the Zarit Burden Interview (short version) and stigma was measured using the Stigma Scale and the Internalised Stigma of Mental Illness Scale.
Results:
Carer burden was significantly higher for schizophrenia than affective disorders. Female carers experienced significantly higher burden than male carers. Diagnosis, gender of carer and stigma predicted 22% of the variance in carer burden, with gender identified as a significant predictor.
Conclusions:
Reducing stigma related to disclosure of mental illness in carers has the potential to reduce carer burden
Hubble and Spitzer Observations of an Edge-on Circumstellar Disk around a Brown Dwarf
We present observations of a circumstellar disk that is inclined close to
edge-on around a young brown dwarf in the Taurus star-forming region. Using
data obtained with SpeX at the NASA Infrared Telescope Facility, we find that
the slope of the 0.8-2.5 um spectrum of the brown dwarf 2MASS J04381486+2611399
cannot be reproduced with a photosphere reddened by normal extinction. Instead,
the slope is consistent with scattered light, indicating that circumstellar
material is occulting the brown dwarf. By combining the SpeX data with mid-IR
photometry and spectroscopy from the Spitzer Space Telescope and previously
published millimeter data from Scholz and coworkers, we construct the spectral
energy distribution for 2MASS J04381486+2611399 and model it in terms of a
young brown dwarf surrounded by an irradiated accretion disk. The presence of
both silicate absorption at 10 um and silicate emission at 11 um constrains the
inclination of the disk to be ~70 deg, i.e. ~20 deg from edge-on. Additional
evidence of the high inclination of this disk is provided by our detection of
asymmetric bipolar extended emission surrounding 2MASS J04381486+2611399 in
high-resolution optical images obtained with the Hubble Space Telescope.
According to our modeling for the SED and images of this system, the disk
contains a large inner hole that is indicative of a transition disk (R_in~58
R_star~0.275 AU) and is somewhat larger than expected from embryo ejection
models (R_out=20-40 AU vs. R_out<10-20 AU).Comment: The Astrophysical Journal, in pres
Into the Mystic: ALMA ACA observations of the Mystic Mountains in Carina
We present new observations of the Mystic Mountains cloud complex in the Carina Nebula using the ALMA Atacama Compact Array (ACA) to quantify the impact of strong UV radiation on the structure and kinematics of the gas. Our Band 6 observations target CO, 13CO, and C18O; we also detect DCN J=3–2 and 13CS J=5–4. A dendrogram analysis reveals that the Mystic Mountains are a coherent structure, with continuous emission over −10.5 km s−1 < v < −2 km s−1. We perform multiple analyses to isolate non-thermal motions in the Mystic Mountains including computing the turbulent driving parameter, b, which indicates whether compressive or solenoidal modes dominate. Each analysis yields values similar to other pillars in Carina that have been observed in a similar way but are subject to an order of magnitude less intense ionizing radiation. We find no clearcorrelation between the velocity or turbulent structure of the gas and the incident radiation, in contrast to other studies targeting different regions of Carina. This may reflect differences in the initial densities of regions that go on to collapse into pillars and those that still look like clouds or walls in the present day. Pre-existing over-densities that enable pillar formation may also explain why star formation in the pillars appears more evolved (from the presence of jets) than in other heavily irradiated but non-pillar-like regions. High resolution observations of regions subject to an array of incident radiation are required to test this hypothesis
Carbamazepine, HLA-B*1502 and risk of Stevens–Johnson syndrome and toxic epidermal necrolysis: US FDA recommendations
Recently, the USA FDA has made a labeling change to the drug information contained in carbamazepine. Owing to recent data implicating the HLA allele B*1502 as a marker for carbamazepine-induced Stevens–Johnson syndrome and toxic epidermal necrolysis in Han Chinese, the FDA recommends genotyping all Asians for the allele. This allele is seen in high frequency in many Asian populations other than Han Chinese, but there are few data on whether the allele is a marker for this severe outcome in anyone other than Han Chinese. In fact, the association has not been found in Caucasian patients. We review the data that prompted this recommendation, list data for other ethnic groups, both Asian and non-Asian, and briefly discuss the implication of this recommendation for clinical practice
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