Cognitive impairments in information processing speed, attention and executive functioning are widely reported in patients with multiple sclerosis (MS). Several studies have identified impaired performance on the Stroop test in people with MS, yet uncertainty remains over the cause of this phenomenon. In this study, 25 patients with MS were assessed with a neuropsychological test battery including a computerized Stroop test and a computerized test of information processing speed, the Graded Conditional Discrimination Tasks (GCDT). The patient group was compared with an individually age, sex and estimated premorbid IQ-matched healthy control group. The patients' reaction times (RTs) were significantly longer than those of the controls on all Stroop test trials and there was a significantly enhanced absolute (RT incongruent -RT neutral ) and relative (100{[RT incongruent -RT neutral ]0RT neutral ) Stroop interference effect for the MS group. The linear function relating RT to stimulus complexity in the GCDT was significantly steeper in the patient group, indicating slowed information processing. The results are discussed with reference to the difference engine model, a theory of diversity in speeded cognition. It is concluded that, in the assessment of people with MS, great caution must be used in the interpretation of performance on neuropsychological tests which rely on RT as the primary measure. (JINS, 2008, 14, 805-814.)

Accessible summary Cognitive analytic consultancy involves mapping the dysfunctional procedures and relationships that exist between team and patient using cognitive analytic theory. The study showed no impact on patient outcomes, but a significant organizational impact in terms of team practices and relationships. Cognitive analytic consultancy offers promise in helping in‐patient and community clinical teams manage those patients not suitable for individual or group psychotherapy. Abstract The objective of this study was to evaluate the clinical and organizational efficacy of formulation‐based consultancy to clinical teams using a randomized control trial methodology. Patients in an Assertive Outreach Team (AOT) were randomized into cognitive analytic consultancy (CAC; n = 10) or treatment as usual (TAU; n = 10). CAC consisted of three consultancy sessions with individual team members to formulate and map the dysfunctional roles and procedures adopted by both patient and team. Subsequent changes to practice were then supported via team supervision. Measures of patient and team functioning were taken across four discrete study phases; (1) baseline team training, (2) case consultation, (3) team supervision and (4) 3‐month follow‐up. Team members were additionally interviewed before and following the trial. No differences were evident between CAC and TAU in terms of patient outcomes. However, the climate of the AOT significantly improved longitudinally over the course of the trial, with CAC facilitating enhanced clinical and team practices. The results are discussed in terms of methodological limitations, the advantages/disadvantages of team consultation and the potential for the further development of the CAC model.

Arsenic doped GaN grown by molecular beam epitaxy has been studied by room temperature photoluminescence. In addition to the wurzite band edge transition, luminescence from the cubic phase and very strong blue emission at ∼2.6 eV are observed. The intensities of the blue and the cubic band edge emissions have a power law dependence on the As2 flux. The formation of the cubic phase has been explained by the initial formation of GaAs before substitution of the As by the more reactive N. The intensity of the blue emission at room temperature of the As doped samples is more than an order of magnitude stronger than the band edge emission in undoped samples.

We have investigated the influence of the growth conditions on the intensity of blue emission at room temperature from As-doped GaN samples grown by molecular beam epitaxy. A series of As-doped GaN samples was grown at 800 • C with constant fluxes of As and gallium, but with different amounts of active nitrogen. Varying the N flux allowed us to investigate films grown from strongly Ga-rich conditions to more N-rich conditions. The blue emission increases monotonically with the nitrogen flux and is most intense in the layers grown under the most nitrogen-rich conditions. This fact suggests that As atoms incorporated into the Ga sub-lattice are responsible for the strong blue emission in As-doped GaN.

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