551 research outputs found

    Hand movement analysis of the elderly when using a remote control

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    The aim of the this project is to study the ability of older subjects to perform basic remote control manipulations and also to specify the minimal functional requirements to perform this activity of daily living

    Challenges in a six-phase process of questionnaire adaptation: findings from the French translation of the Integrated Palliative care Outcome Scale.

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    The Integrated Palliative care Outcome Scale (IPOS) was developed for evaluating essential outcomes for palliative care patients. Our objectives here are to describe the process of a six-phase cross-cultural adaptation of IPOS to French (IPOS-Fr), highlight the difficulties encountered and strategies to solve them, and discuss the implications that adaptation may have on the validity and reliability of a questionnaire. The adaptation of IPOS consisted of six phases: (i) literature review and interviews with target population; (ii) forward translation to French; (iii) backward translation to English; (iv) Expert Review; (v) cognitive interviews with target population; (vi) final review. Translation, cognitive interviews, and exchanges with Expert Review members allowed to make changes adapted to the target language regarding item 5 ("vomiting") and 8 ("sore or dry mouth"), and to identify and address, in the original version of IPOS, syntactic inconsistencies in language used in items 11 to 15 and methodological problems with items 11 ("anxiety about treatment and illness"), 15 ("share … as much as you wanted") and 17 ("problems addressed"). The adaptation also indicated that patients might have difficulties in interpreting items 8 ("sore or dry mouth"), 10 ("poor mobility"), 11 ("anxiety"), 12 (projected feelings of family and friends), and 14 ("feeling at peace"), thus indicating the need of monitoring during the psychometric validation. Following this process, IPOS-Fr has proved content and face validity. In our case, the adaptation allowed adjustments to be made to the questionnaire and, when this was not possible, highlighted potential biases and inconsistencies during the validation. The result relied on an intertwined and iterative process of seeking and reaching semantic, conceptual, and normative equivalence. We are now assessing the psychometrical properties of IPOS-Fr

    A dynamical gluon mass solution in a coupled system of the Schwinger-Dyson equations

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    We study numerically the Schwinger-Dyson equations for the coupled system of gluon and ghost propagators in the Landau gauge and in the case of pure gauge QCD. We show that a dynamical mass for the gluon propagator arises as a solution while the ghost propagator develops an enhanced behavior in the infrared regime of QCD. Simple analytical expressions are proposed for the propagators, and the mass dependency on the ΛQCD\Lambda_{QCD} scale and its perturbative scaling are studied. We discuss the implications of our results for the infrared behavior of the coupling constant, which, according to fits for the propagators infrared behavior, seems to indicate that αs(q2)0\alpha_s (q^2) \to 0 as q20q^2 \to 0.Comment: 17 pages, 7 figures - Revised version to be consistent with erratum to appear in JHE

    Poor farmers - poor yields: socio-economic, soil fertility and crop management indicators affecting climbing bean productivity in northern Rwanda

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    Climbing bean is the key staple legume crop in the highlands of East and Central Africa. We assessed the impact of interactions between soil fertility characteristics, crop management and socio-economic factors, such as household resource endowment and gender of the farmer, on climbing bean productivity and yield responses to basal P fertiliser in northern Rwanda. Through a combination of detailed characterisations of 12 farms and on-farm demonstration trials at 110 sites, we evaluated variability in grain yields and responses to fertiliser. Grain yields varied between 0.14 and 6.9 t ha−1 with an overall average of 1.69 t ha−1. Household resource endowment and gender of the farmer was strongly associated with climbing bean yield, even though these were partly confounded with Sector. Poorer households and women farmers achieved lower yields than wealthier households and male farmers. Household resource endowment and gender were likely to act as proxies for a range of agronomic and crop management factors that determine crop productivity, such as soil fertility, current and past access to organic manure and mineral fertiliser, access to sufficient quality staking material, ability to conduct crop management operation on time, but we found evidence for only some of these relationships. Poorer households and female farmers grew beans on soils with poorer soil fertility. Moreover, poorer households had a lower density of stakes, while stake density was strongly correlated with yield. Diammonium phosphate (DAP) fertiliser application led to a substantial increase in the average grain yield (0.66 t ha−1), but a large variability in responses implied that its use would be economically worthwhile for roughly half of the farmers. For the sake of targeting agricultural innovations to those households that are most likely to adopt, the Ubudehe household typology – a Rwandan government system of wealth categorisation – could be a useful and easily available tool to structure rural households within regions of Rwanda that are relatively uniform in agro-ecology

    Non-perturbative momentum dependence of the coupling constant and hadronic models

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    Models of hadron structure are associated with a hadronic scale which allows by perturbative evolution to calculate observables in the deep inelastic region. The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We use this new development to understand why perturbative treatments are working reasonably well despite the smallness of the hadronic scale.Comment: Changes in Acknowledgments and PACS number

    Is the up-quark massless?

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    We report on determinations of the low-energy constants alpha5 and alpha8 in the effective chiral Lagrangian at O(p^4), using lattice simulations with N_f=2 flavours of dynamical quarks. Precise knowledge of these constants is required to test the hypothesis whether or not the up-quark is massless. Our results are obtained by studying the quark mass dependence of suitably defined ratios of pseudoscalar meson masses and matrix elements. Although comparisons with an earlier study in the quenched approximation reveal small qualitative differences in the quark mass behaviour, numerical estimates for alpha5 and alpha8 show only a weak dependence on the number of dynamical quark flavours. Our results disfavour the possibility of a massless up-quark, provided that the quark mass dependence in the physical three-flavour case is not fundamentally different from the two-flavour case studied here.Comment: references added, typos correcte

    Partially quenched chiral perturbation theory without Φ0\Phi_0

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    This paper completes the argument that lattice simulations of partially quenched QCD can provide quantitative information about QCD itself, with the aid of partially quenched chiral perturbation theory. A barrier to doing this has been the inclusion of Φ0\Phi_0, the partially quenched generalization of the η\eta', in previous calculations in the partially quenched effective theory. This invalidates the low energy perturbative expansion, gives rise to many new unknown parameters, and makes it impossible to reliably calculate the relation between the partially quenched theory and low energy QCD. We show that it is straightforward and natural to formulate partially quenched chiral perturbation theory without Φ0\Phi_0, and that the resulting theory contains the effective theory for QCD without the η\eta'. We also show that previous results, obtained including Φ0\Phi_0, can be reinterpreted as applying to the theory without Φ0\Phi_0. We contrast the situation with that in the quenched effective theory, where we explain why it is necessary to include Φ0\Phi_0. We also compare the derivation of chiral perturbation theory in partially quenched QCD with the standard derivation in unquenched QCD. We find that the former cannot be justified as rigorously as the latter, because of the absence of a physical Hilbert space. Finally, we present an encouraging result: unphysical double poles in certain correlation functions in partially quenched chiral perturbation theory can be shown to be a property of the underlying theory, given only the symmetries and some plausible assumptions.Comment: 45 pages, no figure

    Validation of the French Version of the Integrated Palliative Care Outcome Scale.

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    The Integrated Palliative care Outcome Scale (IPOS) is a widely used tool for assessing patient needs in palliative care. The aim of this study was to provide a validated version of the patient and staff IPOS for French-speaking Switzerland (IPOS-Fr) and assess its psychometric properties. The validation took place in 12 palliative care units and mobile teams. At baseline (T1) and three days later (T2), patients' general health status, palliative care needs (IPOS-Fr), and quality of life (McGill Quality of Life Scale-Revised) were assessed by patients and staff. We included 173 patients (mean age: 68.8; 92 women; 85% oncologic disease). IPOS internal consistency was high for the total score (0.69 and 0.71). Staff-patient interrater agreement was good to moderate for 13 items (intraclass correlations >0.516). Results indicated strong correlations between IPOS-Fr and McGill Quality of Life Scale-Revised for the total score (-0.623 at T1) and the psychological domain (Item 11: -0.601 at T1; Item 13: -0.633 at T2). Regarding sensitivity to change, there was a significant difference between T1 and T2 for patients with an improved health condition (z = -2.326; P = 0.020). IPOS-Fr has fair to good validity, especially with regard to interrater agreement and construct validity, is sensitive to positive change, and has good interpretability and acceptability for patients and staff. IPOS-Fr is not optimal in terms of internal consistency and structure when using subscale scores, except for the emotional subscale

    Chiral Perturbation Theory and Finite Size Effects on the Nucleon Mass in unquenched QCD

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    We calculate finite size effects on nucleon masses in chiral perturbation theory. We confront the theoretical predictions with N_f=2 lattice results and discuss chiral extrapolation formulae.Comment: talk at Lattice 03 (spectrum), 3 pages latex, 3 figures. Assignment of 2 data points to incorrect data sets in plot 1 and of 1 data point in plot 2 corrected. 1 fm lattice result updated. Conclusions unchange

    An intermittent hypercaloric diet alters gut microbiota, prefrontal cortical gene expression and social behaviours in rats.

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    Objectives: Excessive consumption of high fat and high sugar (HFHS) diets alters reward processing, behaviour, and changes gut microbiota profiles. Previous studies in gnotobiotic mice also provide evidence that these gut microorganisms may influence social behaviour. To further investigate these interactions, we examined the impact of the intermittent access to a HFHS diet on social behaviour, gene expression and microbiota composition in adolescent rats. Methods: Male rats were permitted intermittent daily access (2 h / day) to a palatable HFHS chow diet for 28 days across adolescence. Social interaction, social memory and novel object recognition were assessed during this period. Following testing, RT-PCR was conducted on hippocampal and prefrontal cortex (PFC) samples. 16S ribosomal RNA amplicon sequencing was used for identification and relative quantification of bacterial taxa in faecal samples. Results: We observed reduced social interaction behaviours, impaired social memory and novel object recognition in HFHS diet rats compared to chow controls. RT-PCR revealed reduced levels of monoamine oxidase A (Maoa), catechol-O-methyltransferase (Comt) and brain derived neurotrophic factor (Bdnf) mRNA in the PFC of HFHS diet rats. Faecal microbiota analysis demonstrated that the relative abundance of a number of specific bacterial taxa differed significantly between the two diet groups, in particular, Lachnospiraceae and Ruminoccoceae bacteria. Discussion: Intermittent HFHS diet consumption evoked physiological changes to the brain, particularly expression of mRNA associated with reward and neuroplasticity, and gut microbiome. These changes may underpin the observed alterations to social behaviours
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