Accreditation of practice educators: An expectation too far ?

The successful completion of practice placements is essential to the education of occupational therapists; however, ensuring quality placements is challenging for occupational therapy educators. In 2000, Brunel University introduced a revised system of accreditation of practice educators which involved attendance at a course, the supervision of a student and the submission of an essay to be assessed. An audit revealed that a total of 314 therapists attended 15 courses between 2000 and 2003; of these, 243 (77%) subsequently supervised students and 32 (10%) became accredited. The requirement to accredit practice educators, which is a commendable attempt to ensure quality, may paradoxically have been detrimental in achieving quality. The College of Occupational Therapists’ apparent change of emphasis on this topic is welcome

Conceptual techniques for reducing parasitic current gain of lateral pnp transistors

Two techniques have been conceptually proposed as possible means of reducing parasitic beta in lateral p-n-p transistors. One method uses a degenerate substrate and high concentration P /plus/ guard-ring diffusion, another places the base contact at the center of an annular ring structure

Diffusion technique stabilizes resistor values

Reduction of the contact resistance stabilizes the values, over a broad temperature range, of resistors used in linear integrated circuits. This reduction is accomplished by p-plus diffusion under the alloyed aluminum contacts

Enabling occupational therapy students to take a fresh approach to psychosis

This practice evaluation describes the implementation of a 2-day workshop on psychosis with third-year undergraduate occupational therapy students at Brunel University. The work was undertaken by the teaching team at Brunel University, a clinical psychologist working in assertive outreach and an occupational therapist working in community mental health. The background to the project and the way in which the 2-day workshop was adapted to accommodate the university timetable are outlined. An evaluation of the workshop, its place in the occupational therapy programme and the feedback from students are presented

Investigating the Structure of the Windy Torus in Quasars

Thermal mid-infrared emission of quasars requires an obscuring structure that can be modeled as a magneto-hydrodynamic wind in which radiation pressure on dust shapes the outflow. We have taken the dusty wind models presented by Keating and collaborators that generated quasar mid-infrared spectral energy distributions (SEDs), and explored their properties (such as geometry, opening angle, and ionic column densities) as a function of Eddington ratio and X-ray weakness. In addition, we present new models with a range of magnetic field strengths and column densities of the dust-free shielding gas interior to the dusty wind. We find this family of models -- with input parameters tuned to accurately match the observed mid-IR power in quasar SEDs -- provides reasonable values of the Type 1 fraction of quasars and the column densities of warm absorber gas, though it does not explain a purely luminosity-dependent covering fraction for either. Furthermore, we provide predictions of the cumulative distribution of E(B-V) values of quasars from extinction by the wind and the shape of the wind as imaged in the mid-infrared. Within the framework of this model, we predict that the strength of the near-infrared bump from hot dust emission will be correlated primarily with L/L_Edd rather than luminosity alone, with scatter induced by the distribution of magnetic field strengths. The empirical successes and shortcomings of these models warrant further investigations into the composition and behaviour of dust and the nature of magnetic fields in the vicinity of actively accreting supermassive black holes.Comment: 11 pages, 6 figures, accepted for publication in MNRA

The Binary Black Hole Model for Mrk 231 Bites the Dust

Mrk 231 is a nearby quasar with an unusually red near-UV-to-optical continuum, generally explained as heavy reddening by dust (e.g., Leighly et al. 2014). Yan et al. 2015 proposed that Mrk~231 is a milli-parsec black-hole binary with little intrinsic reddening. We show that if the observed FUV continuum is intrinsic, as assumed by Yan et al. 2015, it fails by a factor of about 100 in powering the observed strength of the near-infrared emission lines, and the thermal near and mid-infrared continuum. In contrast, the line and continuum strengths are typical for a reddened AGN spectral energy distribution. We find that the HeI*/Pbeta ratio is sensitive to the spectral energy distribution for a one-zone model. If this sensitivity is maintained in general broad-line region models, then this ratio may prove a useful diagnostic for heavily reddened quasars. Analysis of archival HST STIS and FOC data revealed evidence that the far-UV continuum emission is resolved on size scales of ~40 parsecs. The lack of broad absorption lines in the far-UV continuum might be explained if it were not coincident with the central engine. One possibility is that it is the central engine continuum reflected from the receding wind on the far side of the quasar.Comment: Consistent with the accepted ApJ pape

Near-Infrared Variability in the 2MASS Calibration Fields: A Search for Planetary Transit Candidates

The 2MASS photometric calibration observations cover ~6 square degrees on the sky in 35 "calibration fields" each sampled in nominal photometric conditions between 562 and 3692 times during the four years of the 2MASS mission. We compile a catalog of variables from the calibration observations to search for M dwarfs transited by extra-solar planets. We present our methods for measuring periodic and non-periodic flux variability. From 7554 sources with apparent Ks magnitudes between 5.6 and 16.1, we identify 247 variables, including extragalactic variables and 23 periodic variables. We have discovered three M dwarf eclipsing systems, including two candidates for transiting extrasolar planets.Comment: The Astrophysical Journal Supplement, in press; figures compresse

Spatiotemporal dynamics of quantum jumps with Rydberg atoms

We study the nonequilibrium dynamics of quantum jumps in a one-dimensional chain of atoms. Each atom is driven on a strong transition to a short-lived state and on a weak transition to a metastable state. We choose the metastable state to be a Rydberg state so that when an atom jumps to the Rydberg state, it inhibits or enhances jumps in the neighboring atoms. This leads to rich spatiotemporal dynamics that are visible in the fluorescence of the strong transition.Comment: 10 page