10,038 research outputs found
The treatment of depression and simple phobia through an interpreter in the North East of England : a case study.
A 35-year-old Middle Eastern woman, experiencing moderate depression compounded by animal phobia was referred to an Improving Access to Psychological Therapies (IAPT) service. Shared understandings were gradually developed using written functional analyses translated in session. Activity scheduling was integrated with graded exposure to increase access to positive reinforcement. Questionnaires and subjective data indicated a reduction in phobic avoidance and functioning increased. Despite the complexity of working as a triad, a positive therapeutic relationship was achieved with increased mutual cultural understanding. Indirect communication led to difficulties maintaining guided discovery and focus. There is limited evidence to support CBT when delivered through an interpreter. IAPT recommendations suggest staff reflect the community; the North East has one of the lowest foreign-born populations in the UK indicating that IAPT services may be ill prepared to work with ethnic minorities. Learning points for the therapist were: maintain simplicity, take time to formulate incorporation of cultural difference, and use transcultural interventions. The interpreter brought advantages; providing means of communication and understanding of cultural differences. Disadvantages were the potential for bias or lost information, increased time and complexity of delivering therapy. This case indicates a deficit in high intensity training and lack of literature to support therapists
Velocity shift of surface acoustic waves due to interaction with composite fermions in a modulated structure
We study the effect of a periodic density modulation on surface acoustic wave
(SAW) propagation along a 2D electron gas near Landau level filling .
Within the composite fermion theory, the problem is described in terms of
fermions subject to a spatially modulated magnetic field and scattered by a
random magnetic field. We find that a few percent modulation induces a large
peak in the SAW velocity shift, as has been observed recently by Willett et al.
As further support of this theory we find the dc resistivity to be in good
agreement with recent data of Smet et al.Comment: revised version resubmitted to PRL. Part concerning dc transport
corrected and extended. A new figure showing dc resistivity in comparison
with experiment of Smet et al include
Diffuse emission in the presence of inhomogeneous spin-orbit interaction for the purpose of spin filtration
A lateral interface connecting two regions with different strengths of the
Bychkov-Rashba spin-orbit interaction can be used as a spin polarizer of
electrons in two dimensional semiconductor heterostructures. [Khodas \emph{et
al.}, Phys. Rev. Lett. \textbf{92}, 086602 (2004)]. In this paper we consider
the case when one of the two regions is ballistic, while the other one is
diffusive. We generalize the technique developed for the solution of the
problem of the diffuse emission to the case of the spin dependent scattering at
the interface, and determine the distribution of electrons emitted from the
diffusive region. It is shown that the diffuse emission is an effective way to
get electrons propagating at small angles to the interface that are most
appropriate for the spin filtration and a subsequent spin manipulation.
Finally, a scheme is proposed of a spin filter device, see Fig. 9, that creates
two almost fully spin-polarized beams of electrons.Comment: 11 pages, 9 figure
Excessive noise as a test for many-body localization
Recent experimental reports suggested the existence of a finite-temperature insulator in the vicinity of the superconductor-insulator transition. The rapid decay of conductivity over a narrow temperature range was theoretically linked to both a finite-temperature transition to a many-body-localized state, and to a charge-Berezinskii-Kosterlitz-Thouless transition. Here we report of low-frequency noise measurements of such insulators to test for many-body localization. We observed a huge enhancement of the low-temperatures noise when exceeding a threshold voltage for nonlinear conductivity and discuss our results in light of the theoretical models
On the jets associated with galactic superluminal sources
Recent observations of GRS 1915+105 and GRO J1655+40 reveal superluminal motions in Galactic sources. This letter examines the physical conditions within these Galactic sources, their interaction with their environment, their possible formation, and contrasts them with their extragalactic counterparts. In particular, e^{+}-e^{-} and e-p jets are contrasted, constraints on particle acceleration in the jets are imposed using X-ray and radio observations, the \gamma-ray flux from e^+-e^- jets expected at EGRET energies and the flux in infrared lines from an e-p jet are estimated. It is also suggested that these sources may exhibit low frequency radio lobes extending up to several hundred parsecs in size, strong, soft X-ray absorption during the birth of the radio components and emission line strengths anti-correlated with the X-ray flux. The implications for other X-ray transients are briefly discussed
Probing Micro-quasars with TeV Neutrinos
The jets associated with Galactic micro-quasars are believed to be ejected by
accreting stellar mass black-holes or neutron stars. We show that if the energy
content of the jets in the transient sources is dominated by electron-proton
plasma, then a several hour outburst of 1--100 TeV neutrinos produced by photo-
meson interactions should precede the radio flares associated with major
ejection events. Several neutrinos may be detected during a single outburst by
a 1km^2 detector, thereby providing a powerful probe of micro-quasars jet
physics.Comment: Accepted to PRL. More detailed discussion of particle acceleratio
Neutrino flux predictions for known Galactic microquasars
It has been proposed recently that Galactic microquasars may be prodigious
emitters of TeV neutrinos that can be detected by upcoming km^2 neutrino
telescopes. In this paper we consider a sample of identified microquasars and
microquasar candiates, for which available data enables rough determination of
the jet parameters. By employing the parameters inferred from radio
observations of various jet ejection events, we determine the neutrino fluxes
that should have been produced during these events by photopion production in
the jet. Despite the large uncertainties in our analysis, we demonstrate that
in several of the sources considered, the neutrino flux at Earth, produced in
events similar to those observed, would exceed the detection threshold of a
km^2 neutrino detector. The class of microquasars may contain also sources with
bulk Lorentz factors larger than those characteristic of the sample considered
here, directed along our line of sight. Such sources, which may be very
difficult to resolve at radio wavelengths and hence may be difficult to
identify as microqusar candidates, may emit neutrinos with fluxes significantly
larger than typically obtained in the present analysis. These sources may
eventually be identified through their neutrino and gamma-ray emission.Comment: 17 pages. Submitted to Ap
Zero-energy states in graphene quantum dots and rings
We present exact analytical zero-energy solutions for a class of smooth
decaying potentials, showing that the full confinement of charge carriers in
electrostatic potentials in graphene quantum dots and rings is indeed possible
without recourse to magnetic fields. These exact solutions allow us to draw
conclusions on the general requirements for the potential to support fully
confined states, including a critical value of the potential strength and
spatial extent.Comment: 8 pages, 3 figures, references added, typos corrected, discussion
section expande
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