Spin entanglement, decoherence and Bohm's EPR paradox

We obtain criteria for entanglement and the EPR paradox for spin-entangled particles and analyse the effects of decoherence caused by absorption and state purity errors. For a two qubit photonic state, entanglement can occur for all transmission efficiencies. In this case, the state preparation purity must be above a threshold value. However, Bohm’s spin EPR paradox can be achieved only above a critical level of loss. We calculate a required efficiency of 58%, which appears achievable with current quantum optical technologies. For a macroscopic number of particles prepared in a correlated state, spin entanglement and the EPR paradox can be demonstrated using our criteria for efficiencies η > 1/3 and η > 2/3 respectively. This indicates a surprising insensitivity to loss decoherence, in a macroscopic system of ultra-cold atoms or photons

Pride and glory: Aberdeen Public Library during the Second World War.

Between 1939 and 1945 Britains public libraries often struggled to balance wartime shortages in materials and staff with an increased readership, while also being expected to actively contribute services and skills to the war effort. Government documents, committee minutes, reports, news stories and interviews have been employed in an attempt to build a picture of one particular librarys experiences during this period

Quantifying inbreeding avoidance through extra-pair reproduction

© 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.Peer reviewedPublisher PD

Managing for rainfall variability: effect of grazing strategy on cattle production in a dry tropical savanna

Rainfall variability is a challenge to sustainable and pro. table cattle production in northern Australia. Strategies recommended to manage for rainfall variability, like light or variable stocking, are not widely adopted. This is due partly to the perception that sustainability and profitability are incompatible. A large, long-term grazing trial was initiated in 1997 in north Queensland, Australia, to test the effect of different grazing strategies on cattle production. These strategies are: (i) constant light stocking (LSR) at long-term carrying capacity (LTCC); (ii) constant heavy stocking (HSR) at twice LTCC; (iii) rotational wet-season spelling (R/Spell) at 1.5 LTCC; (iv) variable stocking (VAR), with stocking rates adjusted in May based on available pasture; and (v) a Southern Oscillation Index (SOI) variable strategy, with stocking rates adjusted in November, based on available pasture and SOI seasonal forecasts. Animal performance varied markedly over the 10 years for which data is presented, due to pronounced differences in rainfall and pasture availability. Nonetheless, lighter stocking at or about LTCC consistently gave the best individual liveweight gain (LWG), condition score and skeletal growth; mean LWG per annum was thus highest in the LSR (113 kg), intermediate in the R/Spell (104 kg) and lowest in the HSR(86 kg). MeanLWGwas 106 kg in the VAR and 103 kg in the SOI but, in all years, the relative performance of these strategies was dependent upon the stocking rate applied. After 2 years on the trial, steers from lightly stocked strategies were 60-100 kg heavier and received appreciable carcass price premiums at the meatworks compared to those under heavy stocking. In contrast, LWG per unit area was greatest at stocking rates of about twice LTCC; mean LWG/ha was thus greatest in the HSR (21 kg/ha), but this strategy required drought feeding in four of the 10 years and was unsustainable. Although LWG/ha was lower in the LSR (mean 14 kg/ha), or in strategies that reduced stocking rates in dry years like the VAR(mean 18 kg/ha) and SOI (mean 17 kg/ha), these strategies did not require drought feeding and appeared sustainable. The R/Spell strategy (mean 16 kg/ha) was compromised by an ill-timed fire, but also performed satisfactorily. The present results provide important evidence challenging the assumption that sustainable management in a variable environment is unprofitable. Further research is required to fully quantify the long-term effects of these strategies on land condition and profitability and to extrapolate the results to breeder performance at the property level

Non-parametric comparison of histogrammed two-dimensional data distributions using the Energy Test

When monitoring complex experiments, comparison is often made between regularly acquired histograms of data and reference histograms which represent the ideal state of the equipment. With the larger HEP experiments now ramping up, there is a need for automation of this task since the volume of comparisons could overwhelm human operators. However, the two-dimensional histogram comparison tools available in ROOT have been noted in the past to exhibit shortcomings. We discuss a newer comparison test for two-dimensional histograms, based on the Energy Test of Aslan and Zech, which provides more conclusive discrimination between histograms of data coming from different distributions than methods provided in a recent ROOT release.The Science and Technology Facilities Council, U

Sex-specific additive genetic variances and correlations for fitness in a song sparrow (Melospiza melodia) population subject to natural immigration and inbreeding

ACKNOWLEDGMENTS We thank the Tsawout and Tseycum First Nation bands for access to Mandarte and everyone who contributed to the long-term data collection. We thank the European Research Council for funding and the University of Aberdeen for generous access to the Maxwell High Performance Computing cluster. Pierre de Villemereuil, Michael B. Morrissey, and Jarrod D. Hadfield provided enlightening discussions during manuscript preparation. Joel McGlothlin and two anonymous reviewers provided further helpful comments. DATA ARCHIVING Data have been archived in the Dryad Digital Repository: https://doi.org/10.5061/dryad.p7p1jb3 (Wolak et al. 2018).Peer reviewedPostprintPostprintPublisher PD

A NARRATIVE IN RELIEF The Historiography of English Modern Painting (1910-1915), from the 1910s to the 1950s

The groups of painters in England who experimented with new visual expressions of modernity between 1910 and 1915 are the subject of this historiographical research. More precisely, the accounts of Vorticism, Bloomsbury post-Impressionism and the modern art of painters associated with Sickert, (principally the Camden Town Group), have been critically examined over a forty year period in order to trace the narrative of their place in contemporary art criticism and their entry into histories of what soon became the recent past. This textually-based methodology has produced an insight into the forces acting upon the critical reception of a particular period subsequently seen by historians as a discrete phase in the evolution of British art. The readings of texts are organised chronologically so as to illustrate the formation of a historical narrative and its variants, and to show how immediate responses and retrospective evaluations connect discursively. The findings of the research have four aspects. Firstly, it has been fruitful to isolate the narrative of the years 1910-15 over forty years so as to test whether it is possible, using this longitudinal methodology, to comment productively on the integrity of this historical episode, and to establish how the narrative became a critical orthodoxy governed by a limited range of analytical perspectives. Secondly, estimations as to the quality of the art produced in these years developed a distinct, often negative, patterning in journalism and art historical writing and this is also traced in some detail over time. Dominant tropes in the critical language have been identified over this forty year period which became the default positions of historical analysis and which, I argue, impeded sophisticated or revisionist thinking. With a few notable exceptions, the analysis of early English modern art is poorly served by its commentators in this period and this weakened discursive health. Thirdly, this thesis also considers the nature and influence of, periodicals, newspapers, 'little magazines' and the genres of art-writing that were extant between 1910 and 1956 and relates this to the distinctions and similarities between art criticism and art history at this time. A fourth analytic strand concerns outside influences on the production of critical and historical texts. lt explores the impact of promotional art writing, and exposes the professional pressures on, and rivalries between, writers and considers some of the wider political circumstances through which this particular debate on recent art was refracted