423 research outputs found

    Supporting siblings of children with autistic spectrum disorders (ASDs)

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    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)

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    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

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    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

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    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

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    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)

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    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

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    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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