Music in mind, a randomized controlled trial of music therapy for young people with behavioural and emotional problems: study protocol

Aims. This article is a report of a trial protocol to determine if improvizational music therapy leads to clinically significant improvement in communication and interaction skills for young people experiencing social, emotional or behavioural problems. Background. Music therapy is often considered an effective intervention for young people experiencing social, emotional or behavioural difficulties. However, this assumption lacks empirical evidence. Study design. Musicinmindisamulti-centredsingle-blindrandomizedcontrolledtrial involving 200 young people (aged 8–16 years) and their parents. Eligible participants willhaveaworkingdiagnosiswithintheambitofInternational ClassificationofDisease 10 Mental and Behavioural Disorders and will be recruited over 15 months from six centres within the Child and Adolescent Mental Health Services of a large health and social care trust in Northern Ireland. Participants will be randomly allocated in a 1:1 ratio to receive standard care alone or standard care plus 12 weekly music therapy sessions delivered by the Northern Ireland Music Therapy Trust. Baseline data will be collectedfromyoungpeopleandtheirparentsusingstandardizedoutcomemeasuresfor communicative and interaction skills (primary endpoint), self-esteem, social functioning, depressionandfamilyfunctioning.Follow-updatawillbecollected1and13 weeks afterthefinalmusictherapysession.Acost-effectivenessanalysiswillalsobecarriedout. Discussion. This study will be the largest trial to date examining the effect of music therapy on young people experiencing social, emotional or behavioural difficulties and will provide empirical evidence for the use of music therapy among this population. Trial registration. This study is registered in theISRCTNRegister,ISRCTN96352204. Ethical approval was gained in October 2010.

Optomechanical cooling with generalized interferometers

The fields in multiple-pass interferometers, such as the Fabry-Pérot cavity, exhibit great sensitivity not only to the presence but also to the motion of any scattering object within the optical path. We consider the general case of an interferometer comprising an arbitrary configuration of generic beam splitters and calculate the velocity-dependent radiation field and the light force exerted on a moving scatterer. We find that a simple configuration, in which the scatterer interacts with an optical resonator from which it is spatially separated, can enhance the optomechanical friction by several orders of magnitude.

Exciton-mediated photothermal cooling in GaAs membranes

Cooling of the mechanical motion of a GaAs nano-membrane using the photothermal effect mediated by excitons was recently demonstrated by some of the authors (Usami et al 2012 Nature Phys. 8 168) and provides a clear example of the use of thermal forces to cool down mechanical motion. Here, we report on a single-free-parameter theoretical model to explain the results of this experiment which matches the experimental data remarkably well.

Scattering theory of cooling and heating in optomechanical systems

We present a one-dimensional scattering theory which enables us to describe a wealth of effects arising from the coupling of the motional degree of freedom of scatterers to the electromagnetic field. Multiple scattering to all orders is taken into account. The theory is applied to describe the scheme of a Fabry-Perot resonator with one of its mirrors moving. The friction force, as well as the diffusion, acting on the moving mirror is derived. In the limit of a small reflection coefficient, the same model provides for the description of the mechanical effect of light on an atom moving in front of a mirror.

Cavity cooling of atoms: Within and without a cavity

We compare the efficiencies of two optical cooling schemes, where a single particle is either inside or outside an optical cavity, under experimentally-realisable conditions. We evaluate the cooling forces using the general solution of a transfer matrix method for a moving scatterer inside a general one-dimensional system composed of immobile optical elements. Assuming the same atomic saturation parameter, we find that the two cooling schemes provide cooling forces and equilibrium temperatures of comparable magnitude.

Atom cooling using the dipole force of a single retroreflected laser beam

We present a mechanism for cooling atoms by a laser beam reflected from a single mirror. The cooling relies on the dipole force and thus in principle applies to arbitrary refractive particles including atoms, molecules, or dielectric spheres. Friction and equilibrium temperatures are derived by an analytic perturbative approach. Finally, semiclassical Monte-Carlo simulations are performed to validate the analytic results.