Self-injurious behaviour in individuals with autism spectrum disorder

Background: Autism spectrum disorder (ASD) has been identified as a risk marker for self-injurious behaviour. In this study we aimed to describe the prevalence, topography and correlates of self-injury in individuals with ASD in contrast to individuals with Fragile X and Down syndromes and examine person characteristics associated with self-injury across and within these groups.\ud \ud Method: Carers of individuals with ASD (N=149; mean age=9.98, SD=4.86), Fragile X syndrome (N=123; mean age=15.32, SD=8.74) and Down syndrome (N=49; mean age=15.84, SD=12.59) completed questionnaires relating to the presence and topography of self-injury Information was also gathered regarding demographic characteristics, affect, autistic behaviour, hyperactivity, impulsivity and repetitive behaviour.\ud \ud Results: Self-injurious behaviour was displayed by 50% of the ASD sample; a significantly higher prevalence than in the Down syndrome group (18.4%) but broadly similar to the prevalence in Fragile X syndrome (54.5%). Self-injury was associated with significantly higher levels of autistic behaviour within the Down and Fragile X syndrome groups. Within the ASD group, the presence of self-injury was associated with significantly higher levels of impulsivity and hyperactivity, negative affect and significantly lower levels of ability and speech.\ud \ud Conclusions: Self-injurious behaviour is prevalent in individuals with ASD and the presence of ASD phenomenology increases the risk of self-injury in individuals with known genetic disorders but without a diagnosis of idiopathic autism. Person characteristics associated with self-injury in ASD indicate a role for impaired behavioural inhibition, low levels of ability and negative affect in the development of self-injurious behaviour

Realization of a Laser Cooled Microwave Power Standard (conference digest)

We demonstrate the feasibility of a novel microwave power standard based on the electromagnetic interaction with cold atoms. Under the effect of the radiation, the internal state populations will undergo a Rabi oscillation. The measurement of its frequency will allow the determination of the electromagnetic field strength.Comment: 2 pages, 1 figur

The Ostrich Market

Marketing,

Accuracy of an Atomic Microwave Power Standard

We have built an atomic microwave power standard based on the electromagnetic interaction with laser-cooled atoms. The atoms traversed a waveguide transmission line, and under the effect of the radiation, the internal state populations underwent a Rabi flopping oscillation. Measurement of the oscillation frequency allowed the determination of the incident microwave power. As many of 60 oscillations were observed over a dynamic range of 20 dB and the standard deviation of the measurements was about 0.02%. The measured frequency was compared to a calculated one and an agreement of 1.3% with an uncertainty of 5% (rectangular) was found.Comment: 5 figure

Strain Rate Sensitive Constitutive Equations

Stain rate sensitive constitutive equations using yield criterion which incorporates second and third invariants of stress deviato