Experiences of friendships of young people with first-episode psychosis: A qualitative study

BACKGROUND: First episode psychosis and reduced social networks have been found to go hand in hand, but specific mechanisms are unclear. The manifestation of symptoms and the effect of stigma are two possibilities discussed in the literature but the experiences and views of young people with psychosis have been neglected. AIMS: To explore experiences of friendships of young people with first-episode psychosis, focusing especially on any perceived changes in their friendships or approach to peer relationships as a result of the illness. METHODS: Fourteen participants were interviewed using a semi-structured interview guide, which explored participants' views and experiences of their friendships during the acute phase of illness and in the path to recovery, the impact of friendships on illness experience and of illness on patterns of social contact, and the potential role of services in supporting people with their friendships. Interviews were transcribed verbatim and analysed thematically. RESULTS: Identified themes included the loss of social contacts because both young people developing psychosis withdrew and because friends withdrew as illness developed. Regarding recovery, a unique role was identified for friends and participants were often making conscious efforts to rebuild social networks. Mental health services were viewed as having a limited direct role in this. CONCLUSIONS: Supporting the development of opportunities and skills needed for social relationships following an episode of psychosis may be a useful focus

Neutron optical beam splitter from holographically structured nanoparticle-polymer composites

We report a breakthrough in the search for versatile diffractive elements for cold neutrons. Nanoparticles are spatially arranged by holographical means in a photopolymer. These grating structures show remarkably efficient diffraction of cold neutrons up to about 50% for effective thicknesses of only 200 micron. They open up a profound perspective for next generation neutron-optical devices with the capability to tune or modulate the neutron diffraction efficiency.Comment: 4 pages, 2 figure

The shape dependence of chameleon screening

Chameleon scalar fields can screen their associated fifth forces from detection by changing their mass with the local density. These models are an archetypal example of a screening mechanism, and have become an important target for both cosmological surveys and terrestrial experiments. In particular there has been much recent interest in searching for chameleon fifth forces in the laboratory. It is known that the chameleon force is less screened around non-spherical sources, but only the field profiles around a few simple shapes are known analytically. In this work we introduce a numerical code that solves for the chameleon field around arbitrary shapes with azimuthal symmetry placed in a spherical vacuum chamber. We find that deviations from spherical symmetry can increase the chameleon acceleration experienced by a test particle, and that the least screened objects are those which minimize some internal dimension. For the shapes considered in this work, keeping the mass, density and background environment fixed, the accelerations due to the source varied by a factor of ~ 3