1,243 research outputs found

    Magnetism and half-metallicity at the O surfaces of ceramic oxides

    Get PDF
    The occurence of spin-polarization at ZrO2_{2}, Al2_{2}O3_{3} and MgO surfaces is proved by means of \textit{ab-initio} calculations within the density functional theory. Large spin moments, as high as 1.56 μB\mu_B, develop at O-ended polar terminations, transforming the non-magnetic insulator into a half-metal. The magnetic moments mainly reside in the surface oxygen atoms and their origin is related to the existence of 2p2p holes of well-defined spin polarization at the valence band of the ionic oxide. The direct relation between magnetization and local loss of donor charge makes possible to extend the magnetization mechanism beyond surface properties

    Value co-creation in the delivery of outcome-based contracts for business-to-business service

    Get PDF
    Working paperThis study introduces the concept of outcome-based contracting (OBC) as the mechanism for firms to focus on delivering value-in-use, and as the driver for value co-creation as the firm would need to jointly deliver outcomes with the customer. The paper analyses two OBC-type contracts between the UK Ministry of Defence and two of its industrial partners. We find that in delivering to outcomes and achieving value-in-use, the state-dependent nature of value in usage „pushes back‟ into the organization, requiring the firm to re-evaluate the way they are structured to receive changes from customer state-dependencies so as to deliver a better service. Our analysis presents seven generic attributes of value co-creation (AVCs) essential for the capability to deliver value-in-use. These are behavioral alignment, process alignment, congruence in customer expectations, congruence in firm expectations, empowerment and perceived control, behavioral transformation, and complementary competencies. The attributes discovered through qualitative data were matched with previous academic literature and operationalized and a measurement instrument was developed. The instrument was then validated by performing an exploratory and second order confirmatory factor analysis.This research was made possible through the joint funding of the Engineering & Physical Science Research Council (UK) and BAE Systems on the Support Service Solutions: Strategy & Transition (S4T) project consortium led by the University of Cambridge. The authors gratefully acknowledge the staff of BAE Systems and MBDA as well as members of the ADAPT IPT, 16th Regiment, ATTAC IPT, MoD and the RAF who have all contributed substantially towards this research

    Follow-up monitoring in a cat with leishmaniosis and coinfections with Hepatozoon felis and ‘Candidatus Mycoplasma haemominutum’

    Get PDF
    Case summary A 6-year-old female neutered domestic shorthair cat from Cyprus was presented with multiple ulcerated skin nodules. Cytology and histopathology of the lesions revealed granulomatous dermatitis with intracytoplasmic organisms, consistent with amastigotes of Leishmania species. Biochemistry identified a mild hyperproteinaemia. Blood extraction and PCR detected Leishmania species, Hepatozoon species and ‘Candidatus Mycoplasma haemominutum’ (CMhm) DNA. Subsequent sequencing identified Hepatozoon felis. Additionally, the rRNA internal transcribed spacer 1 locus of Leishmania infantum was partially sequenced and phylogeny showed it to cluster with species derived from dogs in Italy and Uzbekistan, and a human in France. Allopurinol treatment was administered for 6 months. Clinical signs resolved in the second month of treatment with no deterioration 8 months post-treatment cessation. Quantitative PCR and ELISA were used to monitor L infantum blood DNA and antibody levels. The cat had high L infantum DNA levels pretreatment that gradually declined during treatment but increased 8 months post-treatment cessation. Similarly, ELISA revealed high levels of antibodies pretreatment, which gradually declined during treatment and increased slightly 8 months post-treatment cessation. The cat remained PCR positive for CMhm and Hepatozoon species throughout the study. There was no clinical evidence of relapse 24 months post-treatment. Relevance and novel information To our knowledge, this is the first clinical report of a cat with leishmaniosis with H felis and CMhm coinfections. The high L infantum DNA levels post-treatment cessation might indicate that although the lesions had resolved, prolonged or an alternative treatment could have been considere

    Association between canine leishmaniosis and Ehrlichia canis co-infection: a prospective case-control study

    Get PDF
    Abstract Background In the Mediterranean basin, Leishmania infantum is a major cause of disease in dogs, which are frequently co-infected with other vector-borne pathogens (VBP). However, the associations between dogs with clinical leishmaniosis (ClinL) and VBP co-infections have not been studied. We assessed the risk of VBP infections in dogs with ClinL and healthy controls. Methods We conducted a prospective case-control study of dogs with ClinL (positive qPCR and ELISA antibody for L. infantum on peripheral blood) and clinically healthy, ideally breed-, sex- and age-matched, control dogs (negative qPCR and ELISA antibody for L. infantum on peripheral blood) from Paphos, Cyprus. We obtained demographic data and all dogs underwent PCR on EDTA-blood extracted DNA for haemoplasma species, Ehrlichia/Anaplasma spp., Babesia spp., and Hepatozoon spp., with DNA sequencing to identify infecting species. We used logistic regression analysis and structural equation modelling (SEM) to evaluate the risk of VBP infections between ClinL cases and controls. Results From the 50 enrolled dogs with ClinL, DNA was detected in 24 (48%) for Hepatozoon spp., 14 (28%) for Mycoplasma haemocanis, 6 (12%) for Ehrlichia canis and 2 (4%) for Anaplasma platys. In the 92 enrolled control dogs, DNA was detected in 41 (45%) for Hepatozoon spp., 18 (20%) for M. haemocanis, 1 (1%) for E. canis and 3 (3%) for A. platys. No Babesia spp. or “Candidatus Mycoplasma haematoparvum” DNA was detected in any dog. No statistical differences were found between the ClinL and controls regarding age, sex, breed, lifestyle and use of ectoparasitic prevention. A significant association between ClinL and E. canis infection (OR = 12.4, 95% CI: 1.5–106.0, P = 0.022) was found compared to controls by multivariate logistic regression. This association was confirmed using SEM, which further identified that younger dogs were more likely to be infected with each of Hepatozoon spp. and M. haemocanis, and dogs with Hepatozoon spp. were more likely to be co-infected with M. haemocanis. Conclusions Dogs with ClinL are at a higher risk of co-infection with E. canis than clinically healthy dogs. We recommend that dogs diagnosed with ClinL should be tested for E. canis co-infection using PCR

    The ISM in spiral galaxies: can cooling in spiral shocks produce molecular clouds?

    Full text link
    We investigate the thermodynamics of the ISM and the formation of molecular hydrogen through numerical simulations of spiral galaxies. The model follows the chemical, thermal and dynamical response of the disc to an external spiral potential. Self-gravity and magnetic fields are not included. The calculations demonstrate that gas can cool rapidly when subject to a spiral shock. Molecular clouds in the spiral arms arise through a combination of compression of the ISM by the spiral shock and orbit crowding. These results highlight that local self-gravity is not required to form molecular clouds. Self-shielding provides a sharp transition density, below which gas is essentially atomic, and above which the molecular gas fraction is >0.001. The timescale for gas to move between these regimes is very rapid (<~1 Myr). From this stage, the majority of gas generally takes between 10 to 20 Myr to obtain high H2_{2} fractions (>50 %). Although our calculations are unable to resolve turbulent motions on scales smaller than the spiral arm and do not include self-gravity. True cloud formation timescales are therefore expected to be even shorter. The mass budget of the disc is dominated by cold gas residing in the spiral arms. Between 50 and 75 % of this gas is in the atomic phase. When this gas leaves the spiral arm and drops below the self-shielding limit it is heated by the galactic radiation field. Consequently, most of the volume in the interarm regions is filled with warm atomic gas. However, some cold spurs and clumps can survive in interarm regions for periods comparable to the interarm passage timescale. Altogether between 7 and 40% of the gas in our disc is molecular, depending on the surface density of the calculation, with approximately 20% molecular for a surface density comparable to the solar neighbourhood.Comment: 16 pages, 19 figures, accepted for publication in MNRA

    Young people's uses of celebrity: Class, gender and 'improper' celebrity

    Get PDF
    This is an Author's Accepted Manuscript of an article published in Discourse: Studies in the Cultural Politics of Education, 34(1), 2013, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/01596306.2012.698865.In this article, we explore the question of how celebrity operates in young people's everyday lives, thus contributing to the urgent need to address celebrity's social function. Drawing on data from three studies in England on young people's perspectives on their educational and work futures, we show how celebrity operates as a classed and gendered discursive device within young people's identity work. We illustrate how young people draw upon class and gender distinctions that circulate within celebrity discourses (proper/improper, deserving/undeserving, talented/talentless and respectable/tacky) as they construct their own identities in relation to notions of work, aspiration and achievement. We argue that these distinctions operate as part of neoliberal demands to produce oneself as a ‘subject of value’. However, some participants produced readings that show ambivalence and even resistance to these dominant discourses. Young people's responses to celebrity are shown to relate to their own class and gender position.The Arts and Humanities Research Council, the British Academy, the Economic and Social Research Council, and the UK Resource Centre for Women in Science Engineering and Technology

    “We wanted a forever family”: Altruistic, individualistic, and motivated reasoning motivations for adoption among LGBTQ individuals

    Get PDF
    The purpose of this study was to explore motivations for adoption among a diverse sample of LGBTQ adoptive parents and prospective adopters (n = 366), who were recruited through a U.K. network of LGBTQ adoptive and foster families to complete an online survey. Quantitative analysis showed that the majority did not think that being LGBTQ would negatively influence their experience of adopting, although they were evenly split regarding the expectation of whether they would be matched with a harder-to-place child. To explore LGBTQ parents’ motivations for adoption, a thematic analysis of the qualitative data was conducted. One overarching theme was identified Seeking permanency, together with three often closely related subthemes: Altruistic/Moral motivation, Individualistic/Intrinsic motivation, and Motivated reasoning. The findings reflect important changes in U.K. law since the Adoption and Children Act in 2002 permitted same-gender couples to adopt. We suggest ways to inform the recruitment of potential LGBTQ adoptive parents

    'Surely the most natural scenario in the world’: Representations of ‘Family’ in BBC Pre-school Television

    Get PDF
    Historically, the majority of work on British children’s television has adopted either an institutional or an audience focus, with the texts themselves often overlooked. This neglect has meant that questions of representation in British children’s television – including issues such as family, gender, class or ethnicity - have been infrequently analysed in the UK context. In this article, we adopt a primarily qualitative methodology and analyse the various textual manifestations of ‘family’, group, or community as represented in a selected number of BBC pre-school programmes. In doing so, we question the (limited amount of) international work that has examined representations of the family in children’s television, and argue that nuclear family structures do not predominate in this sphere

    Built-in and induced polarization across LaAlO3_3/SrTiO3_3 heterojunctions

    Full text link
    Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. In ultra thin film form however the polar crystals are expected to remain stable without necessitating surface reconstructions, yet the built-in potential has eluded observation. Here we present evidence of a built-in potential across polar \lao ~thin films grown on \sto ~substrates, a system well known for the electron gas that forms at the interface. By performing electron tunneling measurements between the electron gas and a metallic gate on \lao ~we measure a built-in electric field across \lao ~of 93 meV/\AA. Additionally, capacitance measurements reveal the presence of an induced dipole moment near the interface in \sto, illuminating a unique property of \sto ~substrates. We forsee use of the ionic built-in potential as an additional tuning parameter in both existing and novel device architectures, especially as atomic control of oxide interfaces gains widespread momentum.Comment: 6 pages, 4 figures. Submitted to Nature physics on May 1st, 201
    corecore