1,448 research outputs found

    Neutron Scattering and Its Application to Strongly Correlated Systems

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    Neutron scattering is a powerful probe of strongly correlated systems. It can directly detect common phenomena such as magnetic order, and can be used to determine the coupling between magnetic moments through measurements of the spin-wave dispersions. In the absence of magnetic order, one can detect diffuse scattering and dynamic correlations. Neutrons are also sensitive to the arrangement of atoms in a solid (crystal structure) and lattice dynamics (phonons). In this chapter, we provide an introduction to neutrons and neutron sources. The neutron scattering cross section is described and formulas are given for nuclear diffraction, phonon scattering, magnetic diffraction, and magnon scattering. As an experimental example, we describe measurements of antiferromagnetic order, spin dynamics, and their evolution in the La(2-x)Ba(x)CuO(4) family of high-temperature superconductors.Comment: 31 pages, chapter for "Strongly Correlated Systems: Experimental Techniques", edited by A. Avella and F. Mancin

    Examination of the cut-off scores determined by the Ages and Stages Questionnaire in a population-based sample of 6 month-old Norwegian infants

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    <p>Abstract</p> <p>Background</p> <p>Few population-based samples have previously published performance on the Ages and Stages Questionnaire (ASQ), a recommended screening tool to detect infant developmental delay. The aim of the study was to investigate performance on the ASQ in a population-based sample of 6-month-old infants.</p> <p>Methods</p> <p>In this population-based questionnaire study from Oslo, Norway, the 30 item ASQ 6 month Questionnaire (N = 1053) were included, however without the pictograms, and compared to the Norwegian reference sample (N.ref) (N = 169) and to US cut-off values. Exclusion criteria were maternal non-Scandinavian ethnicity, infant age < 5.0 or > 7.0 months (corrected age), twins, and birth weight < 2.5 kg. Cut-off = 2.5 percentile (equivalent to mean minus 2 standard deviations). Pearson's Chi square and Mann-Whitney U were used to compare items and areas, respectively, with N.ref.</p> <p>Results</p> <p>The reported ASQ scores were lower on all but one of the 10 significantly different items, and in all areas except Personal social, compared to the N.ref sample. The estimated cut-off values for suspected developmental delay (Communication 25, Gross motor 15, Fine motor 18, Problem solving 25 and Personal social 20) were lower than the recommended American (US) values in all areas, and lower than the Norwegian values in two areas. Scores indicating need for further assessment were reached by 13.8% or 20.5% of the infants (missing items scored according to the US or the Norwegian manual), and by 33.8% or 30.3% of the infants using the recommended US or the Norwegian cut-off values, in this population-based sample. The Fine motor area demonstrated a large variability depending on the different cut-off and scoring possibilities. Both among the items excluding pictograms and the items that do not have pictograms, approximately every third item differed significantly compared to the N.ref sample.</p> <p>Conclusion</p> <p>The psychomotor developmental scores were lower than in the reference samples in this study of ASQ 6 month Questionnaire; to our knowledge the first study to be both representative and comparatively large. Approximately every third child with birth weight above 2.5 kg, received scores suggesting further assessment using recommended ASQ cut-off scores.</p

    Identifying the domains of context important to implementation science: a study protocol

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    There is growing recognition that "context" can and does modify the effects of implementation interventions aimed at increasing healthcare professionals' use of research evidence in clinical practice. However, conceptual clarity about what exactly comprises "context" is lacking. The purpose of this research program is to develop, refine, and validate a framework that identifies the key domains of context (and their features) that can facilitate or hinder (1) healthcare professionals' use of evidence in clinical practice and (2) the effectiveness of implementation interventions

    Understanding factors associated with the translation of cardiovascular research: A multinational case study approach

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Funders of health research increasingly seek to understand how best to allocate resources in order to achieve maximum value from their funding. We built an international consortium and developed a multinational case study approach to assess benefits arising from health research. We used that to facilitate analysis of factors in the production of research that might be associated with translating research findings into wider impacts, and the complexities involved. Methods: We built on the Payback Framework and expanded its application through conducting co-ordinated case studies on the payback from cardiovascular and stroke research in Australia, Canada and the United Kingdom. We selected a stratified random sample of projects from leading medical research funders. We devised a series of innovative steps to: minimize the effect of researcher bias; rate the level of impacts identified in the case studies; and interrogate case study narratives to identify factors that correlated with achieving high or low levels of impact. Results: Twenty-nine detailed case studies produced many and diverse impacts. Over the 15 to 20 years examined, basic biomedical research has a greater impact than clinical research in terms of academic impacts such as knowledge production and research capacity building. Clinical research has greater levels of wider impact on health policies, practice, and generating health gains. There was no correlation between knowledge production and wider impacts. We identified various factors associated with high impact. Interaction between researchers and practitioners and the public is associated with achieving high academic impact and translation into wider impacts, as is basic research conducted with a clinical focus. Strategic thinking by clinical researchers, in terms of thinking through pathways by which research could potentially be translated into practice, is associated with high wider impact. Finally, we identified the complexity of factors behind research translation that can arise in a single case. Conclusions: We can systematically assess research impacts and use the findings to promote translation. Research funders can justify funding research of diverse types, but they should not assume academic impacts are proxies for wider impacts. They should encourage researchers to consider pathways towards impact and engage potential research users in research processes. © 2014 Wooding et al.; licensee BioMed Central Ltd.RAND Europe and HERG, with subsequent funding from the NHFA, the HSFC and the CIHR. This research was also partially supported by the Policy Research Programme in the English Department of Health

    Parent-Completed Developmental Screening in Premature Children: A Valid Tool for Follow-Up Programs

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    Our goals were to (1) validate the parental Ages and Stages Questionnaires (ASQ) as a screening tool for psychomotor development among a cohort of ex-premature infants reaching 2 years, and (2) analyse the influence of parental socio-economic status and maternal education on the efficacy of the questionnaire. A regional population of 703 very preterm infants (<35 weeks gestational age) born between 2003 and 2006 were evaluated at 2 years by their parents who completed the ASQ, by a pediatric clinical examination, and by the revised Brunet Lezine psychometric test with establishment of a DQ score. Detailed information regarding parental socio-economic status was available for 419 infants. At 2 years corrected age, 630 infants (89.6%) had an optimal neuromotor examination. Overall ASQ scores for predicting a DQ score ≤85 produced an area under the receiver operator curve value of 0.85 (95% Confidence Interval:0.82–0.87). An ASQ cut-off score of ≤220 had optimal discriminatory power for identifying a DQ score ≤85 with a sensitivity of 0.85 (95%CI:0.75–0.91), a specificity of 0.72 (95%CI:0.69–0.75), a positive likelihood ratio of 3, and a negative likelihood ratio of 0.21. The median value for ASQ was not significantly associated with socio-economic level or maternal education. ASQ is an easy and reliable tool regardless of the socio-economic status of the family to predict normal neurologic outcome in ex-premature infants at 2 years of age. ASQ may be beneficial with a low-cost impact to some follow-up programs, and helps to establish a genuine sense of parental involvement

    Microdevices for extensional rheometry of low viscosity elastic liquids : a review

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    Extensional flows and the underlying stability/instability mechanisms are of extreme relevance to the efficient operation of inkjet printing, coating processes and drug delivery systems, as well as for the generation of micro droplets. The development of an extensional rheometer to characterize the extensional properties of low viscosity fluids has therefore stimulated great interest of researchers, particularly in the last decade. Microfluidics has proven to be an extraordinary working platform and different configurations of potential extensional microrheometers have been proposed. In this review, we present an overview of several successful designs, together with a critical assessment of their capabilities and limitations

    Behavioral Problems In The Utilization Of New Technology To Control Caries: Patients And Provider Readiness And Motivation

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    New research developments frequently are neither adopted by providers nor utilized by patients. This dual problem of impacting the behaviors of providers and patients presents a challenge. This paper will present behavioral theories and technologies that can be utilized to impact both provider and patient behaviors

    Routine Antenatal Anti-D Prophylaxis in Women Who Are Rh(D) Negative: Meta-Analyses Adjusted for Differences in Study Design and Quality

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    Background: To estimate the effectiveness of routine antenatal anti-D prophylaxis for preventing sensitisation in pregnant Rhesus negative women, and to explore whether this depends on the treatment regimen adopted. Methods: Ten studies identified in a previous systematic literature search were included. Potential sources of bias were systematically identified using bias checklists, and their impact and uncertainty were quantified using expert opinion. Study results were adjusted for biases and combined, first in a random-effects meta-analysis and then in a random-effects metaregression analysis. Results: In a conventional meta-analysis, the pooled odds ratio for sensitisation was estimated as 0.25 (95 % CI 0.18, 0.36), comparing routine antenatal anti-D prophylaxis to control, with some heterogeneity (I 2 = 19%). However, this naïve analysis ignores substantial differences in study quality and design. After adjusting for these, the pooled odds ratio for sensitisation was estimated as 0.31 (95 % CI 0.17, 0.56), with no evidence of heterogeneity (I 2 = 0%). A meta-regression analysis wa

    FIRE (facilitating implementation of research evidence) : a study protocol

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    Research evidence underpins best practice, but is not always used in healthcare. The Promoting Action on Research Implementation in Health Services (PARIHS) framework suggests that the nature of evidence, the context in which it is used, and whether those trying to use evidence are helped (or facilitated) affect the use of evidence. Urinary incontinence has a major effect on quality of life of older people, has a high prevalence, and is a key priority within European health and social care policy. Improving continence care has the potential to improve the quality of life for older people and reduce the costs associated with providing incontinence aids
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