2,486 research outputs found

    Fit to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules in a renormalon based approach

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    We study the large order behaviour in perturbation theory of the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. In particular, we consider their first infrared renormalons, for which we obtain their analytic structure with logarithmic accuracy and also an approximate determination of their normalization constant. Estimates of higher order terms of the perturbative series are given. The Renormalon subtracted scheme is worked out for these observables and compared with experimental data. Overall, good agreement with experiment is found. This allows us to obtain {\hat a}_0 and some higher-twist non-perturbative constants from experiment: {\hat a}_0=0.141\pm 0.089; f_{3,RS}(1 GeV)=-0.124^{+0.137}_{-0.142} GeV^2.Comment: 23 pages, 18 figures, one reference added, journal versio

    Aspects of birth history and outcome in diplegics attending specialised educational facilities

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    Aim. We aimed to study functional mobility and visual performancein spastic diplegic children and adolescents attending specialisedschools.Methods. Spastic diplegia (SD) was confirmed by clinical examination. Birth and related history were added to explore relationships between SD, birth weight (BW) and duration of pregnancy. Place of birth, BW, gestational age (GA) and length of hospital stay were obtained by means of parental recall. Outcome measures included the functional mobility scale (FMS) and Beery tests of visuomotor integration (VMI) and visual perception (VIS).Results. Forty participants were included (age 7 years 5 months – 19 years 6 months). Term and preterm births were almost equally represented. Functional mobility assessments showed that 20 were walking independently in school and community settings and the remainder used walking aids or wheelchairs. There were no significant correlations between BW or GA and outcomes (FMS, VIS-z-scores or VMI-z-scores) and z-scores were low. VIS scores correlated significantly with chronological age (p=0.024). There were also significant correlations between VIS and VMI scores and school grade appropriateness (p=0.004; p=0.027, respectively). Interpretation. Both term and preterm births were represented, and outcomes were similar regardless of GA. VIS and VMIwere affected in both groups. Half of the group used assistive mobility devices and three-quarters were delayed in terms of their educational level. These problems require specialised teaching strategies, appropriate resources and a school environment that caters for mobility limitations

    Orienting asymmetries in dogs’ responses to different communicatory components of human speech

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    It is well established that in human speech perception the left hemisphere (LH) of the brain is specialized for processing intelligible phonemic (segmental) content (e.g., [1–3]), whereas the right hemisphere (RH) is more sensitive to pro- sodic (suprasegmental) cues [4, 5]. Despite evidence that a range of mammal species show LH specialization when pro- cessing conspecific vocalizations [6], the presence of hemi- spheric biases in domesticated animals’ responses to the communicative components of human speech has never been investigated. Human speech is familiar and relevant to domestic dogs (Canis familiaris), who are known to perceive both segmental phonemic cues [7–10] and supra- segmental speaker-related [11, 12] and emotional [13] proso- dic cues. Using the head-orienting paradigm, we presented dogs with manipulated speech and tones differing in segmental or suprasegmental content and recorded their orienting responses. We found that dogs showed a sig- nificant LH bias when presented with a familiar spoken command in which the salience of meaningful phonemic (segmental) cues was artificially increased but a significant RH bias in response to commands in which the salience of intonational or speaker-related (suprasegmental) vocal cues was increased. Our results provide insights into mech- anisms of interspecific vocal perception in a domesticated mammal and suggest that dogs may share ancestral or convergent hemispheric specializations for processing the different functional communicative components of speech with human listeners

    Tackling ageing continence through theory, tools & technology (TACT3)

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Common Ground.After dementia, nothing is more feared by older people than the loss of continence. It is often the reason many people enter care facilities and can contribute to the breakdown of caring relationships. This paper reports on a three-year research project funded by the UK New Dynamics of Aging programme, which has explored three key issues in the predicament of maintaining continence from the “user’s” perspective. Firstly, understanding how continence services operated by the UK National Health Service can be improved to offer cost effective benefits that encourage people to report this sometimes embarrassing condition with confidence. Secondly, working directly with the US Simon Foundation, the project has developed user-requested, assistive devices that target the most embarrassing aspects of the condition, namely issues of personal odor control and urine leakage from continence pads. Lastly, understanding the challenges of managing continence in daily living outside of the home, with particular reference to accessing publicly accessible toilet facilities. The paper will highlight the research that has provided the basis for innovative design solutions.ESRC, EPSRC, BBSRC, MRC, and AHRC

    Determination of the Kobayashi-Maskawa-Cabibbo matrix element V_{us} under various flavor-symmetry-breaking models in hyperon semileptonic decays

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    We study the success to describe hyperon semileptonic decays of four models that incorporate second-order SU(3) symmetry breaking corrections. The criteria to assess their success is by determining V_{us} in each of the three relevant hyperon semileptonic decays and comparing the values obtained with one another and also with the one that comes from K_{l3} decays. A strong dependence on the particular symmetry breaking model is observed. Values of V_{us} which do not agree with the one of K_{l3} are generally obtained. However, in the context of chiral perturbation theory, only the model whose corrections are O(m_s) and O(m_s^{3/2}) is successful. Using its predictions for the f_1 form factors one can quote a value of V_{us} from this model, namely, V_{us}=0.2176\pm 0.0026, which is in excellent agreement with the K_{l3} one.Comment: Final versio

    Towards an understanding of nucleon spin structure: from hard to soft scales

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    The workshop "The Helicity Structure of the Nucleon" (BNL June 5, 2006) was organized as part of the 2006 RHIC & AGS Users' Meeting to review the status of the spin problem and future directions. The presentations can be found at http://www.phenix.bnl.gov/WWW/publish/caidala/UsersHelicityWorkshop2006/ . Recent data suggests small polarized glue and strangeness in the proton. Here we present a personal summary of the main results and presentations. What is new and exciting in the data, and what might this tell us about the structure of the proton ?Comment: 20 pages, to appear in Int. J. Mod. Phys.

    Tackling Ageing Continence through Theory, Tools & Technology

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    Originally presented at ‘Aging and Society: An Interdisciplinary Conference’, University of California, Berkeley (2011), this article was double-blind peer reviewed, receiving scores of 96% and 73%. It outlines the interdisciplinary research of the cross-Research-Council-funded New Dynamics of Ageing Tackling Ageing Continence through Theory Tools & Technology (TACT3) project (2008–12), which brought together designers, social scientists, bio-engineers, chemists and care-management services to understand the challenges faced by an ageing population in the management of continence. Bichard’s Work Package, ‘Challenging Environmental Barriers to Continence’, explored the need for public toilet provision as essential for quality of life, health and well-being. It developed a life-course methodology that considered ageing from birth through to advanced age (0–101 years), and involved inclusive design research with members of the public and providers of facilities to assess public expectations and provider limitations in service provision. As co-investigator on TACT3, this research built on Bichard’s previous work for the VivaCity2020 consortium (Bichard REF Output 2). Whereas the VivaCity2020 work focused on architectural barriers in toilet provision, the TACT3 project examined the problem in service provision, and how, through inclusive design research, service-design solutions might be explored and implemented. Bichard’s contribution to the TACT3 project produced The Great British Public Toilet Map (http://greatbritishpublictoiletmap.rca.ac.uk/), a public participation website that provides information and locations of public toilets, encouraging members of the public to contact relevant local authorities that have not released information in the format of Open Data. Secondary analysis of TACT3 data for references to issues of personal safety and community initiative in toilet provision was used for the ESRC-funded Robust Accessible Toilets (RATs) project (2011) and produced Publicly Accessible Toilets: An Inclusive Design Guide (2011). Related published conference papers include those in ‘Cumulus 2010’ (China) and ‘Include 2011’ (UK)
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