152 research outputs found

    Student perspectives on creating a positive classroom dynamic: science education in prison

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    Detailed student perspectives on their involvement in prison education are limited in published literature, yet such contributions are invaluable to education practitioners wanting to create inclusive learning environments. This article focuses on the student experience of taking part in a science outreach programme teaching science in prison in England, which was designed to build confidence in students who face challenges in accessing education pathways. Here, former students share their experiences of the programme, as well as other education courses in prison, and offer guidance on best practices for those engaging in outreach or research with the prison population. In particular, their reflections highlight that by creating and maintaining an environment that is accessible, inclusive and relatable, students from all backgrounds are able to engage in course content, and overcome hidden barriers to accessing education. Furthermore, based on their lived experience, the students offer practical advice with regard to improving future access to education in prison. The aim of this article is to give a voice to students in prison about their education experience, highlighting which aspects of this outreach programme (and other education courses) were impactful for them

    Atom-optics hologram in the time domain

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    The temporal evolution of an atomic wave packet interacting with object and reference electromagnetic waves is investigated beyond the weak perturbation of the initial state. It is shown that the diffraction of an ultracold atomic beam by the inhomogeneous laser field can be interpreted as if the beam passes through a three-dimensional hologram, whose thickness is proportional to the interaction time. It is found that the diffraction efficiency of such a hologram may reach 100% and is determined by the duration of laser pulses. On this basis a method for reconstruction of the object image with matter waves is offered.Comment: RevTeX, 13 pages, 8 figures; minor grammatical change

    An updated radiocarbon-based ice margin chronology for the last deglaciation of the North American Ice Sheet Complex

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    The North American Ice Sheet Complex (NAISC; consisting of the Laurentide, Cordilleran and Innuitian ice sheets) was the largest ice mass to repeatedly grow and decay in the Northern Hemisphere during the Quaternary. Understanding its pattern of retreat following the Last Glacial Maximum is critical for studying many facets of the Late Quaternary, including ice sheet behaviour, the evolution of Holocene landscapes, sea level, atmospheric circulation, and the peopling of the Americas. Currently, the most up-to-date and authoritative margin chronology for the entire ice sheet complex is featured in two publications (Geological Survey of Canada Open File 1574 [Dyke et al., 2003]; ‘Quaternary Glaciations – Extent and Chronology, Part II’ [Dyke, 2004]). These often-cited datasets track ice margin recession in 36 time slices spanning 18 ka to 1 ka (all ages in uncalibrated radiocarbon years) using a combination of geomorphology, stratigraphy and radiocarbon dating. However, by virtue of being over 15 years old, the ice margin chronology requires updating to reflect new work and important revisions. This paper updates the aforementioned 36 ice margin maps to reflect new data from regional studies. We also update the original radiocarbon dataset from the 2003/2004 papers with 1541 new ages to reflect work up to and including 2018. A major revision is made to the 18 ka ice margin, where Banks and Eglinton islands (once considered to be glacial refugia) are now shown to be fully glaciated. Our updated 18 ka ice sheet increased in areal extent from 17.81 to 18.37 million km2, which is an increase of 3.1% in spatial coverage of the NAISC at that time. Elsewhere, we also summarize, region-by-region, significant changes to the deglaciation sequence. This paper integrates new information provided by regional experts and radiocarbon data into the deglaciation sequence while maintaining consistency with the original ice margin positions of Dyke et al. (2003) and Dyke (2004) where new information is lacking; this is a pragmatic solution to satisfy the needs of a Quaternary research community that requires up-to-date knowledge of the pattern of ice margin recession of what was once the world’s largest ice mass. The 36 updated isochrones are available in PDF and shapefile format, together with a spreadsheet of the expanded radiocarbon dataset (n = 5195 ages) and estimates of uncertainty for each interval

    Cosmology with clusters of galaxies

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    In this Chapter I review the role that galaxy clusters play as tools to constrain cosmological parameters. I will concentrate mostly on the application of the mass function of galaxy clusters, while other methods, such as that based on the baryon fraction, are covered by other Chapters of the book. Since most of the cosmological applications of galaxy clusters rely on precise measurements of their masses, a substantial part of my Lectures concentrates on the different methods that have been applied so far to weight galaxy clusters. I provide in Section 2 a short introduction to the basics of cosmic structure formation. In Section 3 I describe the Press--Schechter (PS) formalism to derive the cosmological mass function, then discussing extensions of the PS approach and the most recent calibrations from N--body simulations. In Section 4 I review the methods to build samples of galaxy clusters at different wavelengths. Section 5 is devoted to the discussion of different methods to derive cluster masses. In Section 6 I describe the cosmological constraints, which have been obtained so far by tracing the cluster mass function with a variety of methods. Finally, I describe in Section 7 the future perspectives for cosmology with galaxy clusters and the challenges for clusters to keep playing an important role in the era of precision cosmology.Comment: 49 pages, 19 figures, Lectures for 2005 Guillermo Haro Summer School on Clusters, to appear in "Lecture notes in Physics" (Springer

    The product of a Petrine circle? A reassessment of the origin and character of 1 Peter

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    © 2002 SAGE PublicationsRecent studies of 1 Peter, especially by John Elliott, have sought to rescue the letter from its assimilation to the Pauline tradition and to establish the view, now widely held, that 1 Peter is the distinctive product of a Petrine circle. After examining the traditions in 1 Peter, both Pauline and non-Pauline, and the names in the letter (Silvanus, Mark and Peter), this essay argues that there is no substantial evidence, either inside or outside the letter, to support the view of 1 Peter as originating from a specifically Petrine group. It is much more plausibly seen as reflecting the consolidation of early Christian traditions in Roman Christianity. Despite the scholarly majority currently in its favour, the view of 1 Peter as the distinctive product of a Petrine tradition from a Petrine circle should therefore be rejected
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