234 research outputs found

    Temperature development of glassy alpha-relaxation dynamics determined by broadband dielectric spectroscopy

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    We present the temperature dependence of alpha-relaxation times of 13 glass formers determined from broadband dielectric spectroscopy, also including data from aging measurements. The data sets partly cover relaxation-time ranges of up to 16 decades enabling a critical test of the validity of model predictions. For this purpose, the data are provided for electronic download. Here we employ these results to test the applicability of the Vogel-Fulcher-Tammann equation and a recently proposed new approach that was demonstrated to provide superior fits of a vast collection of viscosity data.Comment: 6 pages, 5 figures, final version with minor revisions according to referee demands. The relaxation time data published in the present work can be downloaded at http://link.aps.org/supplemental/10.1103/PhysRevE.81.05150

    Governing policy evaluation? Towards a new typology

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    As policy evaluation matures, thoughts are turning to its governance. However, few scholars have combined insights from the evaluation and governance literatures to shed new light on this matter. In order to address this important gap, this article develops a new typology of ways to comprehend and perhaps ultimately govern ex-post policy evaluation activities. The article then explores its validity in the context of climate policy evaluation activities, a vibrant policy area in which the demand for and practices of evaluation have grown fast, particularly in Europe. The analysis reveals that the typology usefully guides new thinking, but also highlights important gaps in our empirical knowledge of the various modes of governing policy evaluation. The article identifies a need for a new research agenda that simultaneously develops a fuller understanding of these evaluation practices and the options for governing them

    Steps on the Path to Clinical Translation: A workshop by the British and Irish Chapter of the ISMRM

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    The British and Irish Chapter of the International Society for Magnetic Resonance in Medicine (BIC‐ISMRM) held a workshop entitled “Steps on the path to clinical translation” in Cardiff, UK, on 7th September 2022. The aim of the workshop was to promote discussion within the MR community about the problems and potential solutions for translating quantitative MR (qMR) imaging and spectroscopic biomarkers into clinical application and drug studies. Invited speakers presented the perspectives of radiologists, radiographers, clinical physicists, vendors, imaging Contract/Clinical Research Organizations (CROs), open science networks, metrologists, imaging networks, and those developing consensus methods. A round‐table discussion was held in which workshop participants discussed a range of questions pertinent to clinical translation of qMR imaging and spectroscopic biomarkers. Each group summarized their findings via three main conclusions and three further questions. These questions were used as the basis of an online survey of the broader UK MR community

    Memorials to the victims of Nazism: the impact on tourists in Berlin

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    This qualitative study explores tourist responses to memorials to the victims of Nazism in Berlin and the impact they have on the tourist experience. The findings are located in the field of study known as dark tourism, of which visiting memorials is a part. The analysis shows that tourists increased their knowledge of the crimes committed by the Nazis, thus fulfilling the educational function of memorials. Tourists were also overwhelmed by their experience; they attested to feelings of sadness, shock, anger, despair and incomprehension. These feelings made it hard for them to resume the role of tourist after their exposure to a memorial. There was acknowledgement of the extent of commemoration practised in Germany

    Urban nature and transnational lives

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    This paper explores ways in which first generation migrants living in a UK city engage with urban nature. Through understanding mundane connections with local nature (plants, animals and seasons), we attend to two questions ‘what can narratives of urban nature tell us about experiences of migration’, and inversely ‘what can diverse migrant voices tell us about experiences of urban nature’? We draw on interview data with 23 participants, all born overseas, with a diverse mix in terms of age (young adults to older retired people), gender, country of origin and length of time resident in the United Kingdom. The analysis focuses on three areas: multisensory engagements with weather, care for nature and how transnational identities surface through the relational dimensions of nature narratives. We conclude by highlighting the potential of embodied nature engagement to support a sense of wellbeing and transnational identity across the life‐course, with potential to more broadly reflect pluralist understandings of the urban environment

    Bias, Repeatability and Reproducibility of Liver T1 Mapping With Variable Flip Angles.

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    Funder: National Institute for Health Research; Id: http://dx.doi.org/10.13039/501100000272BACKGROUND: Three-dimensional variable flip angle (VFA) methods are commonly used for T1 mapping of the liver, but there is no data on the accuracy, repeatability, and reproducibility of this technique in this organ in a multivendor setting. PURPOSE: To measure bias, repeatability, and reproducibility of VFA T1 mapping in the liver. STUDY TYPE: Prospective observational. POPULATION: Eight healthy volunteers, four women, with no known liver disease. FIELD STRENGTH/SEQUENCE: 1.5-T and 3.0-T; three-dimensional steady-state spoiled gradient echo with VFAs; Look-Locker. ASSESSMENT: Traveling volunteers were scanned twice each (30 minutes to 3 months apart) on six MRI scanners from three vendors (GE Healthcare, Philips Medical Systems, and Siemens Healthineers) at two field strengths. The maximum period between the first and last scans among all volunteers was 9 months. Volunteers were instructed to abstain from alcohol intake for at least 72 hours prior to each scan and avoid high cholesterol foods on the day of the scan. STATISTICAL TESTS: Repeated measures ANOVA, Student t-test, Levene's test of variances, and 95% significance level. The percent error relative to literature liver T1 in healthy volunteers was used to assess bias. The relative error (RE) due to intrascanner and interscanner variation in T1 measurements was used to assess repeatability and reproducibility. RESULTS: The 95% confidence interval (CI) on the mean bias and mean repeatability RE of VFA T1 in the healthy liver was 34 ± 6% and 10 ± 3%, respectively. The 95% CI on the mean reproducibility RE at 1.5 T and 3.0 T was 29 ± 7% and 25 ± 4%, respectively. DATA CONCLUSION: Bias, repeatability, and reproducibility of VFA T1 mapping in the liver in a multivendor setting are similar to those reported for breast, prostate, and brain. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1
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