National survey of occupational therapy managers in mental health

This study, part of the College of Occupational Therapists' Mental Health Project, surveyed occupational therapy managers in mental health to gather data about them, the services they managed and their opinions on current and future issues of importance. A questionnaire was sent to the 184 managers who it was believed worked in mental health and it achieved a 65.2% response rate. The majority of the 120 respondents were female, with Head II therapists between the ages of 31 and 40 forming the largest group. Two-thirds had additional qualifications and 71% had worked in mental health for more than 11 years. In addition to managing occupational therapy services, 86% carried a caseload or managed other services. Aspects of professional management were ranked highest in a list of tasks undertaken. Contradictions were noted in the managers' opinions on recruitment and retention of staff and the importance of staff supervision. The managers displayed commitment to the principles and philosophy of occupational therapy and a determination to demonstrate its effectiveness through research and evidence-based practice. This study contributed to the position paper on the way ahead for occupational therapy in mental health (Craik et al 1998a) and provided information for occupational therapy managers to assist them to review their role

Magnetoelliptic Instabilities

We consider the stability of a configuration consisting of a vertical magnetic field in a planar flow on elliptical streamlines in ideal hydromagnetics. In the absence of a magnetic field the elliptical flow is universally unstable (the ``elliptical instability''). We find this universal instability persists in the presence of magnetic fields of arbitrary strength, although the growthrate decreases somewhat. We also find further instabilities due to the presence of the magnetic field. One of these, a destabilization of Alfven waves, requires the magnetic parameter to exceed a certain critical value. A second, involving a mixing of hydrodynamic and magnetic modes, occurs for all magnetic-field strengths. These instabilities may be important in tidally distorted or otherwise elliptical disks. A disk of finite thickness is stable if the magnetic fieldstrength exceeds a critical value, similar to the fieldstrength which suppresses the magnetorotational instability.Comment: Accepted for publication in Astrophysical Journa

College of occupational therapists: Position paper on the way ahead for research, education and practice in mental health

The future of occupational therapy in mental health has been a topic of reflection and debate. The Education and Research Board (now the Education and Practice Board) of the College of Occupational Therapists created a Working Group to develop a position paper on the way ahead for research, education and practice in mental health. Following consultation, the Working Group reviewed literature, examined current research and surveyed practitioners, managers and educators. From these findings, recommendations have been made which will lead to a firmer evidence base for the practice of occupational therapy in mental health, leading to a more effective use of the expertise of occupational therapists and an improved service for users

Enhancement of the Benjamin-Feir instability with dissipation

It is shown that there is an overlooked mechanism whereby some kinds of dissipation can enhance the Benjamin-Feir instability of water waves. This observation is new, and although it is counterintuitive, it is due to the fact that the Benjamin-Feir instability involves the collision of modes with opposite energy sign (relative to the carrier wave), and it is the negative energy perturbations which are enhanced.Comment: 15 pages, 2 figures To download more papers, go to http://www.cmla.ens-cachan.fr/~dias. Physics of Fluids (2007) to appea

On over-reflection and generation of Gravito-Alfven waves in solar-type stars

The dynamics of linear perturbations is studied in magnetized plasma shear flows with a constant shearing rate and with gravity-induced stratification. The general set of linearized equations is derived and the two-dimensional case is considered in detail. The Boussinesq approximation is used in order to examine relatively small-scale perturbations of low-frequency modes: Gravito-Alfven waves (GAW) and Entropy Mode (EM) perturbations. It is shown that for flows with arbitrary shearing rate there exists a finite time interval of non-adiabatic evolution of the perturbations. The non-adiabatic behavior manifests itself in a twofold way, viz. by the over-reflection of the GAWs and by the generation of GAWs from EM perturbations. It is shown that these phenomena act as efficient transformers of the equilibrium flow energy into the energy of the perturbations for moderate and high shearing rate solar plasma flows. Efficient generation of GAW by EM takes place for shearing rates about an order of magnitude smaller than necessary for development of a shear instability. The latter fact could have important consequences for the problem of angular momentum redistribution within the Sun and solar-type stars.Comment: 20 pages (preprint format), 4 figures; to appear in The Astrophysical Journal (August 1, 2007, v664, N2 issue

Magnetic nanowires as permanent magnet materials

We present the fabrication of metallic magnetic nanowires using a low temperature chemical process. We show that pressed powders and magnetically oriented samples exhibit a very high coercivity (6.5 kOe at 140 K and 4.8 kOe at 300 K). We discuss the magnetic properties of these metamaterials and show that they have the suitable properties to realize "high temperature magnets" competitive with AlNiCo or SmCo permanent magnets. They could also be used as recording media for high density magnetic recording.Comment: 5 pages, 5 figure

Microwave control electrodes for scalable, parallel, single-qubit operations in a surface-electrode ion trap

We propose a surface ion trap design incorporating microwave control electrodes for near-field single-qubit control. The electrodes are arranged so as to provide arbitrary frequency, amplitude and polarization control of the microwave field in one trap zone, while a similar set of electrodes is used to null the residual microwave field in a neighbouring zone. The geometry is chosen to reduce the residual field to the 0.5% level without nulling fields; with nulling, the crosstalk may be kept close to the 0.01% level for realistic microwave amplitude and phase drift. Using standard photolithography and electroplating techniques, we have fabricated a proof-of-principle electrode array with two trapping zones. We discuss requirements for the microwave drive system and prospects for scalability to a large two-dimensional trap array.Comment: 8 pages, 6 figure

Quadratic invariants for discrete clusters of weakly interacting waves

We consider discrete clusters of quasi-resonant triads arising from a Hamiltonian three-wave equation. A cluster consists of N modes forming a total of M connected triads. We investigate the problem of constructing a functionally independent set of quadratic constants of motion. We show that this problem is equivalent to an underlying basic linear problem, consisting of finding the null space of a rectangular M × N matrix with entries 1, −1 and 0. In particular, we prove that the number of independent quadratic invariants is equal to J ≡ N − M* ≥ N − M, where M* is the number of linearly independent rows in Thus, the problem of finding all independent quadratic invariants is reduced to a linear algebra problem in the Hamiltonian case. We establish that the properties of the quadratic invariants (e.g., locality) are related to the topological properties of the clusters (e.g., types of linkage). To do so, we formulate an algorithm for decomposing large clusters into smaller ones and show how various invariants are related to certain parts of a cluster, including the basic structures leading to M* < M. We illustrate our findings by presenting examples from the Charney–Hasegawa–Mima wave model, and by showing a classification of small (up to three-triad) clusters

Growing hydrodynamic modes in Keplerian accretion disks during secondary perturbations: Elliptical vortex effects

The origin of hydrodynamic turbulence, and in particular of an anomalously enhanced angular momentum transport, in accretion disks is still an unsolved problem. This is especially important for cold disk systems which are practically neutral in charge and therefore turbulence can not be of magnetohydrodynamic origin. While the flow must exhibit some instability and then turbulence in support of the transfer of mass inward and angular momentum outward, according to the linear perturbation theory, in absence of magnetohydrodynamic effects, it should always be stable. We demonstrate that the three-dimensional secondary disturbance to the primarily perturbed disk, consisting of elliptical vortices, gives significantly large hydrodynamic growth in such a system and hence may suggest a transition to an ultimately turbulent state. This result is essentially applicable to accretion disks around quiescent cataclysmic variables, in proto-planetary and star-forming disks, the outer region of disks in active galactic nuclei, where the gas is significantly cold and thus the magnetic Reynolds number is smaller than 10^4.Comment: 21 pages including 4 figures, aastex format; Accepted for publication in The Astrophysical Journa

CyBase: a database of cyclic protein sequences and structures, with applications in protein discovery and engineering

CyBase was originally developed as a database for backbone-cyclized proteins, providing search and display capabilities for sequence, structure and function data. Cyclic proteins are interesting because, compared to conventional proteins, they have increased stability and enhanced binding affinity and therefore can potentially be developed as protein drugs. The new CyBase release features a redesigned interface and internal architecture to improve user-interactivity, collates double the amount of data compared to the initial release, and hosts a novel suite of tools that are useful for the visualization, characterization and engineering of cyclic proteins. These tools comprise sequence/structure 2D representations, a summary of grafting and mutation studies of synthetic analogues, a study of N- to C-terminal distances in known protein structures and a structural modelling tool to predict the best linker length to cyclize a protein. These updates are useful because they have the potential to help accelerate the discovery of naturally occurring cyclic proteins and the engineering of cyclic protein drugs. The new release of CyBase is available at http://research1t.imb.uq.edu.au/cybas