Direct Observation of High-Temperature Polaronic Behavior In Colossal Magnetoresistive Manganites

The temperature dependence of the electronic and atomic structure of the colossal magnetoresistive oxides $La_{1-x}Sr_{x}MnO_{3}$ (x = 0.3, 0.4) has been studied using core and valence level photoemission, x-ray absorption and emission, and extended x-ray absorption fine structure spectroscopy. A dramatic and reversible change of the electronic structure is observed on crossing the Curie temperature, including charge localization and spin moment increase of Mn, together with Jahn-Teller distortions, both signatures of polaron formation. Our data are also consistent with a phase-separation scenario.Comment: 5 pages, 4 figures, revte

Coherent magnetic plasmon modes in a contacting gold nano-sphere chain on a gold Slab

A coupled magnetic resonator waveguide, composed of a contacting gold nanosphere chain on a gold slab, is proposed and investigated. A broadband coherent magnetic plasmon mode can be excited in this one dimensional nanostructure. By employing the Lagrangian formalism and the Fourier transform method, the dispersion properties of the wave vector and group velocity of the magnetic plasmon mode are investigated. Small group velocity can be obtained from this system which can be applied as subwavelength slow wave waveguides.Comment: 11pages, 5 figures, This work is published at Optics Express 19, 23782 (2011

Cardiovascular risk in chronic myeloid leukaemia: A multidisciplinary consensus on screening and management

INTRODUCTION: Tyrosine kinase inhibitors (TKIs) have become the mainstay of treatment for chronic myeloid leukaemia (CML), but cardiovascular (CV) risk and exacerbation of underlying risk factors associated with TKIs have become widely debated. Real-world evidence reveals little application of CV risk factor screening or continued monitoring within UK CML management. This consensus paper presents practical recommendations to assist healthcare professionals in conducting CV screening/comorbidity management for patients receiving TKIs. METHODS: We conducted a multidisciplinary panel meeting and two iterative surveys involving 10 CML specialists: five haematologists, two cardio-oncologists, one vascular surgeon, one haemato-oncology pharmacist and one specialist nurse practitioner. RESULTS: The panel recommended that patients commencing second-/third-generation TKIs undergo formal CV risk assessment at baseline, with additional investigations and involvement of cardiologists/vascular surgeons for those with high CV risk. During treatment, patients should undergo CV monitoring, with the nature and frequency of testing dependent on TKI and baseline CV risk. For patients who develop CV adverse events, decision-making around TKI interruption, cessation or change should be multidisciplinary and balance CV and haematological risk. CONCLUSION: The panel anticipates these recommendations will support healthcare professionals in implementing CV risk screening and monitoring, broadly and consistently, and thereby help optimise TKI treatment for CML

Parental agency, identity and knowledge: mothers of children with dyslexia

This is a postprint of an article whose final and definitive form has been published in the Oxford Review of Education© 2004 Copyright Taylor & Francis; Oxford Review of Education is available online at http://www.informaworld.comIn this paper we report and analyse findings from part of a two-year evaluation project which focuses on parent-professional communications over the issues of learning difficulties arising from dyslexia. The key concepts in this study are dyslexia friendly schools and parental partnership, which are discussed in the current policy interest in inclusive education and parent partnership. A conceptual framework has been derived from the study which focuses on parental strategies to ensure adequate provision for their children, knowledge about dyslexia and identity, in particular that of the mother of the child with dyslexia. Excerpts from in-depth interviews of parents are then presented to illustrate the framework. The significance of the findings is examined in relation to other studies of parent partnership. Implications for a more inclusive version of extended professionalism are also considered

Parental cultural models and resources for understanding mathematical achievement in culturally diverse school settings

This paper proposes that the theoretical concept of cultural models can offer useful insights into parental involvement in their child’s mathematical achievement and the resources they use to go about gaining information in culturally diverse learning settings. This examination takes place within a cultural-developmental framework and draws on the notion of cultural models to explicate parental understandings of their child’s mathematics achievement and what resources are used to make sense of this. Three parental resources are scrutinized: (a) the teacher, (b) examination test results, and (c) constructions of child development. The interviews with 22 parents revealed some ambiguity around the interpretation of these resources by the parent, which was often the result of incongruent cultural models held between the home and the school. The resources mentioned are often perceived as being unambiguous but show themselves instead to be highly interpretive because of the diversity of cultural models in existence in culturally diverse settings. Parents who are in minority or marginalized positions tend to have difficulties in interpreting cultural models held by school, thereby disempowering them to be parentally involved in the way the school would like

Local lattice disorder in the geometrically-frustrated spin glass pyrochlore Y2Mo2O7

The geometrically-frustrated spin glass Y2Mo2O7 has been considered widely to be crystallographically ordered with a unique nearest neighbor magnetic exchange interaction, J. To test this assertion, we present x-ray-absorption fine-structure results for the Mo and Y K edges as a function of temperature and compare them to results from a well-ordered pyrochlore, Tl2Mn2O7. We find that the Mo-Mo pair distances are significantly disordered at approximately right angles to the Y-Mo pairs. These results strongly suggest that lattice disorder nucleates the spin-glass phase in this material.Comment: 9 pages, 2 Postscript figures, Phys. Rev. B: Rapid, in pres

Minimax Current Density Coil Design

'Coil design' is an inverse problem in which arrangements of wire are designed to generate a prescribed magnetic field when energized with electric current. The design of gradient and shim coils for magnetic resonance imaging (MRI) are important examples of coil design. The magnetic fields that these coils generate are usually required to be both strong and accurate. Other electromagnetic properties of the coils, such as inductance, may be considered in the design process, which becomes an optimization problem. The maximum current density is additionally optimized in this work and the resultant coils are investigated for performance and practicality. Coils with minimax current density were found to exhibit maximally spread wires and may help disperse localized regions of Joule heating. They also produce the highest possible magnetic field strength per unit current for any given surface and wire size. Three different flavours of boundary element method that employ different basis functions (triangular elements with uniform current, cylindrical elements with sinusoidal current and conic section elements with sinusoidal-uniform current) were used with this approach to illustrate its generality.Comment: 24 pages, 6 figures, 2 tables. To appear in Journal of Physics D: Applied Physic

Slow crossover in YbXCu4 intermediate valence compounds

We compare the results of measurements of the magnetic susceptibility Chi(T), the linear coefficient of specific heat Gamma(T)=C(T)/T and 4f occupation number nf(T) for the intermediate valence compounds YbXCu4 (X = Ag, Cd, In, Mg, Tl, Zn) to the predictions of the Anderson impurity model, calculated in the non-crossing approximation (NCA). The crossover from the low temperature Fermi liquid state to the high temperature local moment state is substantially slower in the compounds than predicted by the NCA; this corresponds to the ''protracted screening'' recently predicted for the Anderson Lattice. We present results for the dynamic susceptibility, measured through neutron scattering experiments, to show that the deviations between theory and experiment are not due to crystal field effects, and we present x-ray-absorption fine-structure (XAFS) results that show the local crystal structure around the X atoms is well ordered, so that the deviations probably do not arise from Kondo Disorder. The deviations may correlate with the background conduction electron density, as predicted for protracted screening.Comment: Submitted to Physical Review B on June 7, 2000, accepted for publication November 2, 2000. Changes to the original manuscript include: 1) a discussion of the relation of the slow crossover to the conduction electron density; 2) a discussion of the relation of the reported results to earlier photoemission results; and, 3) minor editorial change

Labour market experiences of young UK Bangladeshi men: Identity, inclusion and exclusion in inner-city London

Detailed qualitative data are used to explore the processes perpetuatinglabour market disadvantage among young UK-Bangladeshi men living in central London. Strong forces of inclusion within the Bangladeshi community are found to interact with forces of exclusion from ‘mainstream’ society to constrain aspirations and limit opportunities. Though diverse forms of young Bangladeshi masculinity are found, a common pattern is heavy dependency on intra-ethnic networks. Negative experiences of and isolation from ‘mainstream’ society further reinforce reliance on ‘our own people’. However, acute ambivalence towards belonging to a dense Bangladeshi community exists, exemplified in the widespread denigration of the restaurant trade. Many respondents express the desire to ‘break out’ and access new experiences. The findings support current policy emphasis on ‘connecting people to work’ but highlight the more fundamental need to connect people across ethnic boundaries. The paper urges researchers to ‘unpack’ ethnicity to consider carefully what ethnic identity implies in terms of access to resources and opportunities for different individuals in different contexts in order better to understand the diversity of labour market outcomes and the persistence of disadvantage