Charge asymmetry in high-energy μ+μ−\mu^+\mu^- photoproduction in the electric field of a heavy atom

The charge asymmetry in the differential cross section of high-energy $\mu^+\mu^-$ photoproduction in the electric field of a heavy atom is obtained. This asymmetry arises due to the Coulomb corrections to the amplitude of the process (next-to-leading term with respect to the atomic field). The deviation of the nuclear electric field from the Coulomb field at small distances is crucially important for the charge asymmetry. Though the Coulomb corrections to the total cross section are negligibly small, the charge asymmetry is measurable for selected final states of $\mu^+$ and $\mu^-$. We further discuss the feasibility for experimental observation of this effect.Comment: 6 pages, 3 figure

Natural history contributions of the University of Glasgow Exploration Society to Scotland and the World

Expeditions with a natural history focus have been organised by University of Glasgow staff and students since the 1930s. The educational benefits of such expeditions to students have been reported by Harper et al. ( Journal of Biological Education 51, 3- 16; 2017). Here, we present a short history of these expeditions, concentrating on their scientific achievements. In addition to expedition reports, a large number of PhD theses, masters and honours project reports and scientific papers have been based on expedition work. Many biological specimens have been deposited in museums, including some new species. We provide case histories of four expedition locations, to demonstrate the variety of work done, and the value of returning many times to the same place: Scotland, Trinidad and Tobago, North Cyprus and Ecuador. A major problem for expeditions is funding. For many years, the Carnegie Trust for the Universities of Scotland ran a funding stream that was crucial to the viability of Scottish university expeditions, but this has sadly now closed. For Glasgow University expeditions, the Blodwen Lloyd Binns Bequest has provided a reliable source since 1994, and we hope that it will continue to do so

Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess whether blue-light filtering spectacle lenses impart effects on visual function, provide protection to the macula, or both. We will also examine potential effects on the sleep-wake cycle

A Critical Appraisal of National and International Clinical Practice Guidelines Reporting Nutritional Recommendations for Age-Related Macular Degeneration: Are Recommendations Evidence-Based?

Eye care professionals should have access to high quality clinical practice guidelines that ideally are underpinned by evidence from robust systematic reviews of relevant research. The aim of this study was to identify clinical guidelines with recommendations pertaining to dietary modification and/or nutritional supplementation for age-related macular degeneration (AMD), and to evaluate the overall quality of the guidelines using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument. We also mapped recommendations to existing systematic review evidence. A comprehensive search was undertaken using bibliographic databases and other electronic resources for eligible guidelines. Quality appraisal was undertaken to generate scores for each of the six AGREE II domains, and mapping of extracted nutritional recommendations was performed for systematic reviews published up to March 2017. We identified 13 national and international guidelines, developed or updated between 2004 and 2019. These varied substantially in quality. The lowest scoring AGREE II domains were for 'Rigour of Development', 'Applicability' (which measures implementation strategies to improve uptake of recommendations), and 'Editorial Independence'. Only four guidelines used evidence from systematic reviews to support their nutritional recommendations. In conclusion, there is significant scope for improving current Clinical Practice Guidelines for AMD, and guideline developers should use evidence from existing high quality systematic reviews to inform clinical recommendations

Creative professional users musical relevance criteria

Although known item searching for music can be dealt with by searching metadata using existing text search techniques, human subjectivity and variability within the music itself make it very difficult to search for unknown items. This paper examines these problems within the context of text retrieval and music information retrieval. The focus is on ascertaining a relationship between music relevance criteria and those relating to relevance judgements in text retrieval. A data-rich collection of relevance judgements by creative professionals searching for unknown musical items to accompany moving images using real world queries is analysed. The participants in our observations are found to take a socio-cognitive approach and use a range of content and context based criteria. These criteria correlate strongly with those arising from previous text retrieval studies despite the many differences between music and text in their actual content

Structural, magnetic and electrical properties of the hexagonal ferrites MFeO3 (M=Y, Yb, In)

We thank EPSRC for funding, STFC for providing neutron facilities and Diamond Light Source for provision of synchrotron facilities. We thank Dr Chiu Tang for assistance at Diamond and Dr A. Kusmartseva (University of Edinburgh) for assistance with the SQUID measurements. FDM thanks the Royal Society for a Research Fellowship.The hexagonal ferrites MFeO3 (M=Y, Yb, In) have been studied using a combination of neutron and X-ray powder diffraction, magnetic susceptibility, dielectric measurements and 57Fe Mössbauer spectroscopy. This study confirms the previously reported crystal structure of InFeO3 (YAlO3 structure type, space group P63/mmc), but YFeO3 and YbFeO3 both show a lowering of symmetry to at most P63cm (ferrielectric YMnO3 structure type). However, Mössbauer spectroscopy shows at least two distinct Fe sites for both YFeO3 and YbFeO3 and we suggest that the best model to rationalise this involves phase separation into more than one similar hexagonal YMnO3-like phase. Rietveld analysis of the neutron diffraction data was carried out using two hexagonal phases as a simplest case scenario. In both YFeO3 and YbFeO3, distinct dielectric anomalies are observed near 130 K and 150 K, respectively. These are tentatively correlated with weak anomalies in magnetic susceptibility and lattice parameters, for YFeO3 and YbFeO3, respectively, which may suggest a weak magnetoelectric effect. Comparison of neutron and X-ray powder diffraction shows evidence of long-range magnetic order in both YFeO3 and YbFeO3 at low temperatures. Due to poor sample crystallinity, the compositional and structural effects underlying the phase separation and possible magnetoelectric phenomena cannot be ascertained.PostprintPeer reviewe

Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)

This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface