5,899 research outputs found

    Corrections to Sirlin's Theorem in O(p6)O(p^6) Chiral Perturbation Theory

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    We present the results of the first two-loop calculation of a form factor in full SU(3)×SU(3)SU(3) \times SU(3) Chiral Perturbation Theory. We choose a specific linear combination of π+,K+,K0\pi^+, K^+, K^0 and KπK\pi form factors (the one appearing in Sirlin's theorem) which does not get contributions from order p6p^6 operators with unknown constants. For the charge radii, the correction to the previous one-loop result turns out to be significant, but still there is no agreement with the present data due to large experimental uncertainties in the kaon charge radii.Comment: 6 pages, Latex, 2 LaTeX figure

    Merging fragments of classical logic

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    We investigate the possibility of extending the non-functionally complete logic of a collection of Boolean connectives by the addition of further Boolean connectives that make the resulting set of connectives functionally complete. More precisely, we will be interested in checking whether an axiomatization for Classical Propositional Logic may be produced by merging Hilbert-style calculi for two disjoint incomplete fragments of it. We will prove that the answer to that problem is a negative one, unless one of the components includes only top-like connectives.Comment: submitted to FroCoS 201

    The assessment of efforts to return to work in the European Union

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    Background: Assessment of efforts to promote return-to-work (RTW) includes all efforts (vocational and non-vocational) designed to improve the work ability of the sick-listed employee and increase the chance to return to work. Aim of the study was to investigate whether in 13 European countries these RTW efforts are assessed and to compare the procedures by means of six criteria. METHODS: Data were gathered in the taxonomy project of the European Union of Medicine in Assurance and Social Security and by means of an additional questionnaire. RESULTS: In seven countries RTW efforts are subject of the assessment in relation to the application for disability benefits. Description of RTW efforts is a prerequisite in five countries. Guidelines on the assessment of RTW efforts are only available in the Netherlands and no countries report the use of the ICF model. Based on the results of the additional questionnaire, the assessor is a social scientist or a physician. The information used to assess RTW efforts differs, from a report on the RTW process to medical information. A negative outcome of the assessment leads to delay of the application for disability benefits or to application for rehabilitation subsidy. Conclusion: RTW efforts are assessed in half of the participating European countries. When compared, the characteristics of the assessment of RTW efforts in the participating European countries show both similarities and differences. This study may facilitate the gathering and exchange of knowledge and experience between countries on the assessment of RTW efforts

    Electronic Scattering Effects in Europium-Based Iron Pnictides

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    In a comprehensive study, we investigate the electronic scattering effects in EuFe2_{2}(As1−x_{1-x}Px_{x})2_{2} by using Fourier-transform infrared spectroscopy. In spite of the fact that Eu2+^{2+} local moments order around TEu≈20T_\text{Eu} \approx 20\,K, the overall optical response is strikingly similar to the one of the well-known Ba-122 pnictides. The main difference lies within the suppression of the lower spin-density-wave gap feature. By analysing our spectra with a multi-component model, we find that the high-energy feature around 0.7\,eV -- often associated with Hund's rule coupling -- is highly sensitive to the spin-density-wave ordering, this further confirms its direct relationship to the dynamics of itinerant carriers. The same model is also used to investigate the in-plane anisotropy of magnetically detwinned EuFe2_{2}As2_{2} in the antiferromagnetically ordered state, yielding a higher Drude weight and lower scattering rate along the crystallographic aa-axis. Finally, we analyse the development of the room temperature spectra with isovalent phosphor substitution and highlight changes in the scattering rate of hole-like carriers induced by a Lifshitz transition

    Change in environmental barriers experienced over a 5-year period by people living with spinal cord injury in Switzerland:a prospective cohort study

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    STUDY DESIGN: Cohort study with two measurement occasions. OBJECTIVES: To investigate change in environmental barriers experienced by people living with spinal cord injury (SCI) over a 5-year period. SETTING: Community, Switzerland. METHODS: Data were from the Swiss spinal cord injury (SwiSCI) survey. Main outcome measure was the Nottwil Environmental Factors Inventory-Short Form. Random-effects Poisson regression featuring between-within estimation was used to examine predictors of the number of environmental barriers and of its change over time. RESULTS: One thousand five hundred and forty-nine persons participated in Survey 2012 and 1530 participated in Survey 2017; 761 participated in both surveys. In both surveys most participants reported at least three barriers. Leading issues were unfavorable climate, inaccessibility of buildings and public spaces, and lack of or insufficiently adapted means of transportation. Reporting of barriers related to climate, finances, and state services declined over time. Between subjects, having more health problems, lesser physical independence, poorer mental health, and a lower household income were related to a higher number of barriers experienced. Within subjects, improvements in income, physical independence, and mental health over time were related to a reduction in barriers. CONCLUSIONS: Inaccessibility of buildings and places and problems with transportation remained major barriers over a 5-year period and should be priorities of Swiss disability policy. People with reduced mental and physical health, and those with lower income are vulnerable groups deserving specific attention. Policies targeting income and life-long rehabilitation targeting health promotion and maintenance may be suitable means to reduce the experience of environmental barriers

    Effective Theories for Circuits and Automata

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    Abstracting an effective theory from a complicated process is central to the study of complexity. Even when the underlying mechanisms are understood, or at least measurable, the presence of dissipation and irreversibility in biological, computational and social systems makes the problem harder. Here we demonstrate the construction of effective theories in the presence of both irreversibility and noise, in a dynamical model with underlying feedback. We use the Krohn-Rhodes theorem to show how the composition of underlying mechanisms can lead to innovations in the emergent effective theory. We show how dissipation and irreversibility fundamentally limit the lifetimes of these emergent structures, even though, on short timescales, the group properties may be enriched compared to their noiseless counterparts.Comment: 11 pages, 9 figure
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