8,040 research outputs found
Emergence of interaction effects in Bose-Einstein condensation
No full textWe present a quantitative evaluation of the predictions of mean-field theory for describing a Bose-Einstein condensate in a magnetic trap by comparing directly with experimental observations. We study the release energy from ballistic expansion and the cloud density profile as a function of mean-field effects. Significant departure of the cloud shape from both the noninteracting limit and the strongly repulsive limit is observed for our parameters, consistent with theoretical prediction
Correction:Is treatment with pimobendan associated with an increased risk of arrhythmias in dogs with heart disease? (Veterinary Record (2018) 183 (693-695) DOI: 10.1136/vr.k5167)
No full textThe author list was incomplete on publication of this article. The author list should have included Rebecca Tedford, Samantha Partridge and Edward Cooper and the author list order should have been as below. Hillyer S, Tedford R, Partridge S, Cooper E, Hezzell MJ, Place E.</p
The SF-36: a simple, effective measure of mobility disability for epidemiological studies
No full textBackgroundMobility disability is a major problem in older people. Numerous scales exist for the measurement of disability but often these do not permit comparisons between study groups. The physical functioning (PF) domain of the established and widely used Short Form-36 (SF-36) questionnaire asks about limitations on ten mobility activities.ObjectivesTo describe prevalence of mobility disability in an elderly population, investigate the validity of the SF-36 PF score as a measure of mobility disability, and to establish age and sex specific norms for the PF score.MethodsWe explored relationships between the SF-36 PF score and objectively measured physical performance variables among 349 men and 280 women, 59-72 years of age, who participated in the Hertfordshire Cohort Study (HCS). Normative data were derived from the Health Survey for England (HSE) 1996.Results32% of men and 46% of women had at least some limitation in PF scale items. Poor SF-36 PF scores (lowest fifth of the gender-specific distribution) were related to: lower grip strength; longer timed-up-and-go, 3m walk, and chair rises test times in men and women; and lower quadriceps peak torque in women but not men. HSE normative data showed that median PF scores declined with increasing age in men and women.ConclusionOur results are consistent with the SF-36 PF score being a valid measure of mobility disability in epidemiological studies. This approach might be a first step towards enabling simple comparisons of prevalence of mobility disability between different studies of older people. The SF-36 PF score could usefully complement existing detailed schemes for classification of disability and it now requires validation against them
Tool use and related errors in ideational apraxia: The quantitative simulation of patient error profiles
No full textThe behaviour of ideational apraxic patients on simple tasks involving multiple objects is typically marked by a variety of errors. While some of these errors concern the sequential organisation of action through time, many relate to the misuse of, or failure to use, necessary or appropriate tools. In this paper we apply the computational model of Cooper & Shallice (2000) to five standard multiple object tasks used in clinical assessment and demonstrate how, when lesioned, the model can account for the error profiles of two ideational apraxic patients discussed by Rumiati et al. (2001). Application of the model to the multiple object tasks demonstrates the generality of the model, while the account of the error profiles extends previous work (Cooper et al., 2005) in which ideational apraxia was argued to arise from a generalised disturbance of object representations that are held to trigger action schemas
Superfluidity of an atomic Fermi gas near the unitarity limit
No full textWe show that the thermodynamic properties of an atomic Fermi gas near the unitarity limit for Feshbach scattering is not universal as long as the resonance is narrow on the scale of the Fermi energy. In view of ongoing quantum Monte Carlo simulations, we explore this behavior within a mean-field approach extended to a finite temperature by means of a model potential, which allows for a tuning of the scattering phase shift and its energy dependence. Our results may be relevant for constructing a complete theoretical description of the crossover from a Bose-Einstein condensation (BEC) of composite bosons to a Bardeen-Cooper-Schrieffer (BCS) of Cooper pairs
Self-compression of 4.9 µm pulses to sub-40 fs with 2 mJ energy in Zinc Sulfide
No full textNonlinear self-compression of few-cycle multi-mJ pulses at 4.9 µm in ZnS is presented. 80 fs input pulses are compressed to 37 fs with 2.1 mJ energy at a 1 kHz repetition rate. © 2024 The Author(s
Depolarization effects in pulsed photoionization of state-selected lithium
No full textAlguard MJ, Clendenin JE, Cooper PS, et al. Depolarization effects in pulsed photoionization of state-selected lithium. Phys.Rev. A. 1977;16(1):209-212
Cognitive theory in anorexia nervosa and bulimia nervosa: progress, development and future directions.
No full textImportant developments have taken place in cognitive theory of eating disorders (EDs) (and also in other disorders) since the review paper published by M.J. Cooper in 1997. The relevant empirical database has also expanded. Nevertheless, cognitive therapy for anorexia nervosa and bulimia nervosa, although helpful to many patients, leaves much to be desired. The current paper reviews the relevant empirical evidence collected, and the theoretical revisions that have been made to cognitive models of eating disorders, since 1997. The status and limitations of these developments are considered, including whether or not they meet the criteria for "good" theory. New theoretical developments relevant to cognitive explanations of eating disorders (second generation theories) are then presented, and the preliminary evidence that supports these is briefly reviewed. The lack of integration between cognitive theories of EDs and risk (vulnerability) factor research is noted, and a potential model that unites the two is noted. The implications of the review for future research and the development of cognitive theory in eating disorders are then discussed. These include the need for study of cognitive constructs not yet fully integrated (or indeed not yet applied clinically) into current theories and the need for cognitive theories of eating disorders to continue to evolve (as they have indeed done since 1997) in order to fully integrate such constructs. Treatment studies incorporating these new developments also urgently need to be undertaken
Resonance effects on the crossover of bosonic to fermionic superfluidity
No full textFeshbach scattering resonances are being utilized in atomic gases to explore the entire crossover region from a Bose-Einstein condensation (BEC) of composite bosons to a Bardeen-Cooper-Schrieffer (BCS) of Cooper pairs. Several theoretical descriptions of the crossover have been developed based on an assumption that the fermionic interactions are dependent only on the value of a single microscopic parameter, the scattering length for the interaction of fermion particles. Such a picture is not universal, however, and is only applicable to describe a system with an energetically broad Feshbach resonance. In the more general case in which narrow Feshbach resonances are included in the discussion, one must consider how the energy dependence of the scattering phase shift affects the physical properties of the system. We develop a theoretical framework which allows for a tuning of the scattering phase shift and its energy dependence, whose parameters can be fixed from realistic scattering solutions of the atomic physics. We show that BCS-like non-local solutions may build up in conditions of resonance scattering, depending on the effective range of the interactions. (C) 2004 Elsevier B.V. All rights reserved
Polarized electron-electron scattering at GeV energies
No full textCooper PS, Alguard MJ, Ehrlich RD, et al. Polarized electron-electron scattering at GeV energies. Phys.Rev.Lett. 1975;34(25):1589-1592
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