421 research outputs found
Supporting siblings of children with autistic spectrum disorders (ASDs)
Section A: A review of current research literature relating to the impact of child ASD upon non-affected siblings and the utility of sibling group interventions. The first section summarises and critiques studies relating to the social, emotional and behavioural adjustment of siblings, including consideration of potential mediating factors and discussion of methodological issues. The second section considers evidence for one intervention for this group, ASD-specific sibling support groups. The review suggests that inconsistencies remain within the sibling research literature and that there is a clear need for UK-based outcome research.
Section B: Background: Having a brother or sister with an ASD can be challenging for non-affected siblings. These children may experience reduced parental attention, isolation from peers and difficult sibling behaviours. This pilot study aimed to investigate the utility of support groups for siblings of children with ASDs.
Methods: A within group, mixed methods design was used with a pre-intervention baseline. Participants were 35 children, aged 7-15 years, with an ASD sibling. All were attending ASD-specific sibling group interventions across the South East of England. Sibling rated self-concept, anxiety and anger and parent-rated emotional difficulties were collected at pre group, post group and follow up. One group also participated in a focus group.
Results: Results indicated significant improvements in self concept and significant decreases in anger and anxiety following participation in an ASD-specific sibling group. Anxiety continued to decrease at 3 month follow up. Parent-rated sibling emotional difficulties did not change. All siblings valued the groups. Four main themes were identified from qualitative data: Siblings valued the opportunity to meet similar others, have fun, learn new information about ASD and apply this knowledge to their own situation.
Conclusions: The present pilot study extends existing literature on ASD-specific sibling groups. This is one of the first studies to combine qualitative data with standardised outcome measures. Participation in an ASD-specific support group may be associated with more positive self concept and decreased anger and anxiety. Given inherent study limitations, further, controlled research studies are warranted.
Section C: A critical appraisal of the study conducted in section B and a reflective account of the process. This includes consideration of research skills learnt, future adaptations, clinical implications and ideas for future research
The sub-millimetre evolution of V4334 Sgr (Sakurai's Object)
We report the results of monitoring of V4334 Sgr (Sakurai's Object) at 450
microns and 850 microns with SCUBA on the James Clerk Maxwell Telescope. The
flux density at both wavelengths has increased dramatically since 2001, and is
consistent with continued cooling of the dust shell in which Sakurai's Object
is still enshrouded, and which still dominates the near-infrared emission.
Assuming that the dust shell is optically thin at sub-millimetre wavelengths
and optically thick in the near-infrared, the sub-millimetre data imply a
mass-loss rate during 2003 of ~3.4(+/0.2)E-5 for a gas-to-dust ratio of 75.
This is consistent with the evidence from 1-5micron observations that the
mass-loss is steadily increasing.Comment: 5 pages, 4 eps figures, accepted for publication in MNRA
Resumption of mass accretion in RS Oph
The latest outburst of the recurrent nova RS Oph occurred in 2006 February. Photometric data presented here show evidence of the resumption of optical flickering, indicating re-establishment of accretion by day 241 of the outburst. Magnitude variations of up to 0.32 mag in V band and 0.14 mag in B band on time-scales of 600–7000 s are detected. Over the two-week observational period, we also detect a 0.5 mag decline in the mean brightness, from V≈ 11.4 to 11.9, and record B≈ 12.9 mag. Limits on the mass accretion rate of [inline image] are calculated, which span the range of accretion rates modelled for direct wind accretion and Roche lobe overflow mechanisms. The current accretion rates make it difficult for thermonuclear runaway models to explain the observed recurrence interval, and this implies average accretion rates are typically higher than seen immediately post-outburst
V723 Cas (Nova Cassiopeiae 1995): MERLIN observations from 1996 to 2001
MERLIN observations of the unusually slow nova V723 Cas are presented. Nine
epochs of 6-cm data between 1996 and 2001 are mapped, showing the initial
expansion and brightening of the radio remnant, the development of structure
and the final decline. A radio light curve is presented and fitted by the
standard Hubble flow model for radio emission from novae in order to determine
the values of various physical parameters for the shell. The model is
consistent with the overall development of the radio emission. Assuming a
distance of 2.39 (+/-0.38) kpc and a shell temperature of 17000 K, the model
yields values for expansion velocity of 414 +/- 0.1 km s^-1 and shell mass of
1.13 +/- 0.04 * 10^-4 Msolar. These values are consistent with those derived
from other observations although the ejected masses are rather higher than
theoretical predictions. The structure of the shell is resolved by MERLIN and
shows that the assumption of spherical symmetry in the standard model is
unlikely to be correct.Comment: 6 pages, 6 figure
Sakurai's Object: characterizing the near-infrared CO ejecta between 2003 and 2007
We present observations of Sakurai's Object obtained at 1–5 μm between 2003 and 2007. By fitting a radiative transfer model to an echelle spectrum of CO fundamental absorption features around 4.7 μm, we determine the excitation conditions in the line-forming region. We find 12C/13C = 3.5+2.0−1.5, consistent with CO originating in ejecta processed by the very late thermal pulse, rather than in the pre-existing planetary nebula. We demonstrate the existence of 2.2 × 10−6≤MCO≤ 2.7 × 10−6 M⊙ of CO ejecta outside the dust, forming a high-velocity wind of 500 ± 80 km s−1. We find evidence for significant weakening of the CO band and cooling of the dust around the central star between 2003 and 2005. The gas and dust temperatures are implausibly high for stellar radiation to be the sole contributor
The onset of photoionization in Sakurai's Object (V4334 Sgr)
We investigate the reheating of the very late thermal pulse (VLTP) object
V4334 Sgr (Sakurai's Object) using radio observations from the Very Large
Array, and optical spectra obtained with the Very Large Telescope. We find a
sudden rise of the radio flux at 5 and 8 GHz - from <= 90 micro-Jy and 80 +/-
30 micro-Jy in February 2005 to 320 micro-Jy and 280 micro-Jy in June 2006.
Optical line emission is also evolving, but the emission lines are fading. The
optical line emission and early radio flux are attributed to a fast shock (and
not photoionization as was reported earlier) which occurred around 1998. The
fading is due to post-shock cooling and recombination. The recent rapid
increase in radio flux is evidence for the onset of photoionization of carbon
starting around 2005. The current results indicate an increase in the stellar
temperature to 12 kK in 2006. The mass ejected in the VLTP eruption is M_ej >=
1e-4 Msol, but could be as high as 1e-2 Msol, depending mainly on the distance
and the clumping factor of the outflow. We derive a distance between 1.8 and 5
kpc. A high mass loss could expose the helium layer and yield abundances
compatible with those of [WC] and PG1159 stars.Comment: 4 pages, 2 figures; accepted for publication in A&A letter
The symbiotic star CH Cygni. III. A precessing radio jet
VLA, MERLIN and Hubble Space Telescope imaging observations of the extended
regions of the symbiotic system CH Cygni are analysed. These extensions are
evidence of a strong collimation mechanism, probably an accretion disk
surrounding the hot component of the system. Over 16 years (between 1985 and
2001) the general trend is that these jets are seen to precess. Fitting a
simple ballistic model of matter ejection to the geometry of the extended
regions suggests a period of 6520 +/- 150 days, with a precession cone opening
angle of 35 +/- 1 degrees. This period is of the same order as that proposed
for the orbital period of the outer giant in the system, suggesting a possible
link between the two. Anomalous knots in the emission, not explained by the
simple model, are believed to be the result of older, slower moving ejecta, or
possibly jet material that has become disrupted through sideways interaction
with the surrounding medium.Comment: 9 pages, 4 figure
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