2,972 research outputs found
Sensitivity of the ATLAS Experiment to Extra Dimensions
In the late nineties several authors suggested that the extra dimensions predicted by string theory might lead to observable effects at high energy colliders. The ATLAS experiment which will start taking data at the LHC in 2007 will be an excellent place to search for such effects. A large set of models within the ADD or the Randall Sundrum geometries has been studied in ATLAS. These models predict a variety of signatures: jets and missing energy from direct graviton production, high mass tails in dilepton and diphoton production due to virtual graviton exchange, production of Kaluza-Klein excitations of standard model particles, etc. The sensitivity of ATLAS to these signatures will be presented
Rational-Emotive Therapy: A Cognitive-Behavioral Approach to Working with Hearing Impaired Clients
This paper serves to present to deafness rehabilitation specialists the basic assumptions and process of Rational-Emotive Therapy. As a forerunner in the field of cognitive-behavioral therapy, RET provides a framework and specific interventions to meet a wide variety of client needs. A discussion of suggested techniques designed specifically for a portion of the deaf population is included. The flexibility of the RET approach in offering the options of both elegant and inelegant resolution of emotional disturbance enhances the usefulness of this theory with the diverse population of deaf clients
Mental health, men and culture: how do sociocultural constructions of masculinities relate to men’s mental health help-seeking behaviour in the WHO European Region?
Modular Quantum Memories Using Passive Linear Optics and Coherent Feedback
In this paper, we show that quantum memory for qudit states encoded in a single photon pulsed optical field has a conceptually simple modular realization using only passive linear optics and coherent feedback. We exploit the idea that two decaying optical cavities can be coupled in a coherent feedback configuration to create an internal mode of the coupled system which is isolated and decoherence-free for the purpose of qubit storage. The qubit memory can then be switched between writing/read-out mode and storage mode simply by varying the routing of certain freely propagating optical fields in the network. It is then shown that the qubit memories can be interconnected with one another to form a qudit quantum memory. We explain each of the phase of writing, storage, and read-out for this modular quantum memory scheme. The results point a way towards modular architectures for complex compound quantum memories
The many faces of disability in evidence for policy and practice: embracing complexity
Background: This special issue examines the relationship between disability, evidence, and policy. Key points: Several themes cut across the included papers. Despite the development of models of disability that recognise its socially constructed nature, dis/ableism impedes the involvement of people with disability in evidence production and use. The resultant incomplete representations of disability are biased towards its deproblematisation. Existing data often homogenise the heterogeneous. Functioning and impairment categories are used for surveys, research recruitment and policy enactments, that exclude many. Existing data may crudely evidence some systematic inequalities, but the successful and appropriate development and enactment of disability policies requires more contextual data. Categories and labels drawn from a deficit model affect social constructions of identity, and have been used socially and politically to justify the disenfranchisement of people with disability. Well rehearsed within welfare systems, this results in disempowered and devalued objects of policy, and, as described in one Brazilian paper, the systematic breakup of indigenous families. Several studies show the dangers of policy developed without evidence and impact assessments from and with the intended beneficiaries. Conclusions and implications: There is a need to mitigate barriers to inclusive participation, to enable people with disability to collaborate as equals with other policy actors. The combined application of different policy models and ontologies, currently in tension, might better harness their respective strengths and encourage greater transparency and deliberation regarding the flaws inherent in each. Learning should be shared across minority groups
Longevity and mortality of cats attending primary care veterinary practices in England
Enhanced knowledge on longevity and mortality in cats should support improved breeding, husbandry, clinical care and disease prevention strategies. The VetCompass research database of primary care veterinary practice data offers an extensive resource of clinical health information on companion animals in the UK. This study aimed to characterise longevity and mortality in cats, and to identify important demographic risk factors for compromised longevity. Crossbred cats were hypothesised to live longer than purebred cats. Descriptive statistics were used to characterise the deceased cats. Multivariable linear regression methods investigated risk factor association with longevity in cats that died at or after 5 years of age. From 118,016 cats attending 90 practices in England, 4009 cats with confirmed deaths were randomly selected for detailed study. Demographic characterisation showed that 3660 (91.7%) were crossbred, 2009 (50.7%) were female and 2599 (64.8%) were neutered. The most frequently attributed causes of mortality in cats of all ages were trauma (12.2%), renal disorder (12.1%), non-specific illness (11.2%), neoplasia (10.8%) and mass lesion disorders (10.2%). Overall, the median longevity was 14.0 years (interquartile range [IQR] 9.0–17.0; range 0.0–26.7). Crossbred cats had a higher median longevity than purebred cats (median [IQR] 14.0 years [9.1–17.0] vs 12.5 years [6.1–16.4]; P \u3c0.001), but individual purebred cat breeds varied substantially in longevity. In cats dying at or after 5 years (n = 3360), being crossbred, having a lower bodyweight, and being neutered and non-insured were associated with increased longevity. This study described longevity in cats and identified important causes of mortality and breed-related associations with compromised longevity
Green's functions for far-side seismic images: a polar expansion approach
We have computed seismic images of magnetic activity on the far surface of
the Sun by using a seismic-holography technique. As in previous works, the
method is based on the comparison of waves going in and out of a particular
point in the Sun but we have computed here the Green's functions from a
spherical polar expansion of the adiabatic wave equations in the Cowling
approximation instead of using the ray-path approximation previously used in
the far-side holography. A comparison between the results obtained using the
ray theory and the spherical polar expansion is shown. We use the
gravito-acoustic wave equation in the local plane-parallel limit in both cases
and for the latter we take the asymptotic approximation for the radial
dependencies of the Green's function. As a result, improved images of the
far-side can be obtained from the polar-expansion approximation, especially
when combining the Green's functions corresponding to two and three skips. We
also show that the phase corrections in the Green's functions due to the
incorrect modeling of the uppermost layers of the Sun can be estimated from the
eigenfrequencies of the normal modes of oscillation.Comment: 8 pages, 5 figures, Astrophysical Journal, accepted (2010
Medipix3 Demonstration and understanding of near ideal detector performance for 60 & 80 keV electrons
In our article we report first quantitative measurements of imaging
performance for the current generation of hybrid pixel detector, Medipix3, as
direct electron detector. Utilising beam energies of 60 & 80 keV, measurements
of modulation transfer function (MTF) and detective quantum efficiency (DQE)
have revealed that, in single pixel mode (SPM), energy threshold values can be
chosen to maximize either the MTF or DQE, obtaining values near to, or even
exceeding, those for an ideal detector. We have demonstrated that the Medipix3
charge summing mode (CSM) can deliver simultaneous, near ideal values of both
MTF and DQE. To understand direct detection performance further we have
characterized the detector response to single electron events, building an
empirical model which can predict detector MTF and DQE performance based on
energy threshold. Exemplifying our findings we demonstrate the Medipix3 imaging
performance, recording a fully exposed electron diffraction pattern at 24-bit
depth and images in SPM and CSM modes. Taken together our findings highlight
that for transmission electron microscopy performed at low energies (energies
<100 keV) thick hybrid pixel detectors provide an advantageous and alternative
architecture for direct electron imagin
Stellar Envelope Convection calibrated by Radiation Hydrodynamics Simulations: Influence on Globular Clusters Isochrones
One of the largest sources of uncertainty in the computation of globular
cluster isochrones and hence in the age determination of globular clusters is
the lack of a rigorous description of convection. Therefore, we calibrated the
superadiabatic temperature gradient in the envelope of metal-poor low-mass
stars according to the results from a new grid of 2D hydrodynamical models,
which cover the Main Sequence and the lower Red Giant Branch of globular
cluster stars. In practice, we still use for computing the evolutionary stellar
models the traditional mixing length formalism, but we fix the mixing length
parameter in order to reproduce the run of the entropy of the deeper adiabatic
region of the stellar envelopes with effective temperature and gravity as
obtained from the hydro-models. The detailed behaviour of the calibrated mixing
length depends in a non-trivial way on the effective temperature, gravity and
metallicity of the star. Nevertheless, the resulting isochrones for the
relevant age range of galactic globular clusters have only small differences
with respect to isochrones computed adopting a constant solar calibrated value
of the mixing length. Accordingly, the age of globular clusters is reduced by
0.2 Gyr at most.Comment: 9 pages, 3 figures Accepted for publication in ApJ Letter
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