831 research outputs found

    Governing through trust: community-based link workers and parental engagement in education

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    This article seeks to further understandings of contemporary patterns of parental government. Parenting has emerged as a key policy domain in twenty-first century Britain and we explore the politicisation of family life by examining a pilot programme tasked with enhancing parental engagement in education amongst ‘hard-to-reach’ families within the white British community of a large inner-London borough. Concentrating upon the programme’s signature device – the deployment of community-based ‘link workers’ to bridge home and school – ‘governmentality’ (Foucault, 2009) is used as a theoretical lens through which to foreground the link workers’ role in governing parents. We draw on qualitative data collected from link workers, parents, and school leaders, to argue that link workers represent a mode of governmentality that privileges the instrumental use of trust to achieve strategic objectives, rather than coercive authority. The aim being to produce responsible, self-disciplined parents who act freely in accordance with normative expectations as to what constitutes ‘good’ parenting and effective parental support. As such, the article highlights the link workers’ role in (re)producing the ideal, neoliberal parent. However, governing through trust comes at the cost of being unable to firmly secure desired outcomes. We thereby conclude that this gentle art of parental government affords parents some latitude in resisting institutional agendas

    The change of Fermi surface topology in Bi2Sr2CaCu2O8 with doping

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    We report the observation of a change in Fermi surface topology of Bi2Sr2CaCu2O8 with doping. By collecting high statistics ARPES data from moderately and highly overdoped samples and dividing the data by the Fermi function, we answer a long standing question about the Fermi surface shape of Bi2Sr2CaCu2O8 close to the (pi,0) point. For moderately overdoped samples (Tc=80K) we find that both the bonding and antibonding sheets of the Fermi surface are hole-like. However for a doping level corresponding to Tc=55K we find that the antibonding sheet becomes electron-like. This change does not directly affect the critical temperature and therefore the superconductivity. However, since similar observations of the change of the topology of the Fermi surface were observed in LSCO and Bi2Sr2Cu2O6, it appears to be a generic feature of hole-doped superconductors. Because of bilayer splitting, though, this doping value is considerably lower than that for the single layer materials, which again argues that it is unrelated to Tc

    Identifying the Background Signal in ARPES of High Temperature Superconductors

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    One of the interesting features of the photoemission spectra of the high temperature cuprate superconductors is the presence of a large signal (referred to as the "background'') in the unoccupied region of the Brillouin zone. Here we present data indicating that the origin of this signal is extrinsic and is most likely due to strong scattering of the photoelectrons. We also present an analytical method that can be used to subtract the background signal

    Using the unique spectral signature of guano to identify unknown seabird colonies

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    Despite the threats faced by seabirds in both terrestrial and marine habitats, even basic knowledge of the locations of colonies, population sizes and trends is lacking for many remote areas of the world. Recent studies have shown that the guano of Adélie penguins can be identified from Landsat Enhanced Thematic Mapper (ETM) imagery and used to map colonies on coasts around continental Antarctica. Our study highlights a new technique based on the unique spectral signature of guano that can be used to discriminate seabird colonies from background geology and vegetation in a wider range of natural environments, including the vegetated and zoologically-diverse region of the Antarctic Peninsula; moreover, the method was effective for all densely colonial, surface-nesting seabirds. Using Landsat ETM imagery, we correctly identified all known seabird colonies of over 50 pairs in the area of Marguerite Bay. Almost all other areas with a similar spectral signature that were outside known breeding areas were single pixels that were readily distinguishable from genuine colonies. If these were excluded, only 4.1% of pixels appeared to represent unknown breeding or roosting sites, and warrant further investigation. The spatial extent of the guano provided a general guide to the number of individuals present, but further work would be required to determine the accuracy of this method for estimating population size. Spectral profiles of guano collected by satellite and hand-held spectrometers were compared with available data in spectral libraries and did not match with any known geological profile. There may also be potential for discriminating colonies of different species that differ in phenology and show seasonal changes in diet by the carefully-timed acquisition of suitable satellite imagery. We conclude that the remotely-sensed guano signature is a good indicator of the location of seabird breeding or roosting sites, with potentially wide application to other areas of the world

    Dual character of the electronic structure in YBa2Cu4O8: conduction bands of CuO2 planes and CuO chains

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    We use microprobe Angle-Resolved Photoemission Spectroscopy (muARPES) to separately investigate the electronic properties of CuO2 planes and CuO chains in the high temperature superconductor, YBa2Cu4O8. In the CuO2 planes, a two dimensional (2D) electronic structure with nearly momentum independent bilayer splitting is observed. The splitting energy is 150 meV at (pi,0), almost 50% larger than in Bi2Sr2CaCu2O(8+d) and the electron scattering at the Fermi level in the bonding band is about 1.5 times stronger than in the antibonding band. The CuO chains have a quasi one dimensional (1D) electronic structure. We observe two 1D bands separated by ~ 550meV: a conducting band and an insulating band with an energy gap of ~ 240meV. We find that the conduction electrons are well confined within the planes and chains with a non-trivial hybridization.Comment: 4 pages, 4 figure

    Momentum anisotropy of the scattering rate in cuprate superconductors

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    We examine the momentum and energy dependence of the scattering rate of the high temperature cuprate superconductors using angle resolved photoemission spectroscopy. The scattering rate is of the form a + b*w. The inelastic coefficient b is found to be isotropic. The elastic term, a, however, is found to be highly anisotropic in the pseudogap phase of optimal doped samples, with an anisotropy which correlates with that of the pseudogap. This can be contrasted with heavily overdoped samples, which show an isotropic scattering rate in the normal state
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