Sickle cell, habitual dys-positions and fragile dispositions: young people with sickle cell at school

The experiences of young people living with a sickle cell disorder in schools in England are reported through a thematic analysis of forty interviews, using Bourdieu’s notions of field, capital and habitus. Young people with sickle cell are found to be habitually dys-positioned between the demands of the clinic for health maintenance through self-care and the field of the school, with its emphases on routines, consistent attendance and contextual demands for active and passive pupil behaviour. The tactics or dispositions that young people living with sickle cell can then employ, during strategy and struggle at school, are therefore fragile: they work only contingently, transiently or have the unintended consequences of displacing other valued social relations. The dispositions of the young people with sickle cell are framed by other social struggles: innovations in school procedures merely address aspects of sickle cell in isolation and are not consolidated into comprehensive policies; mothers inform, liaise, negotiate and advocate in support of a child with sickle cell but with limited success. Reactions of teachers and peers to sickle cell have the enduring potential to drain the somatic, cultural and social capital of young people living with sickle cell

Riemann-Hilbert approach to multi-time processes; the Airy and the Pearcey case

We prove that matrix Fredholm determinants related to multi-time processes can be expressed in terms of determinants of integrable kernels \`a la Its-Izergin-Korepin-Slavnov (IIKS) and hence related to suitable Riemann-Hilbert problems, thus extending the known results for the single-time case. We focus on the Airy and Pearcey processes. As an example of applications we re-deduce a third order PDE, found by Adler and van Moerbeke, for the two-time Airy process.Comment: 18 pages, 1 figur

Quantum Heisenberg Chain with Long-Range Ferromagnetic Interactions at Low Temperature

A modified spin-wave theory is applied to the one-dimensional quantum Heisenberg model with long-range ferromagnetic interactions. Low-temperature properties of this model are investigated. The susceptibility and the specific heat are calculated; the relation between their behaviors and strength of the long-range interactions is obtained. This model includes both the Haldane-Shastry model and the nearest-neighbor Heisenberg model; the corresponding results in this paper are in agreement with the solutions of both the models. It is shown that there exists an ordering transition in the region where the model has longer-range interactions than the HS model. The critical temperature is estimated.Comment: 17 pages(LaTeX REVTeX), 1 figure appended (PostScript), Technical Report of ISSP A-274

Magnetic properties of quantum Heisenberg ferromagnets with long-range interactions

Quantum Heisenberg ferromagnets with long-range interactions decayin as $1/r^p$ in one and two dimensions are investigated by means of the Green's function method. It is shown that there exists a finite-temperature phase transition in the region $d<p<2 d$ for the $d$-dimensional case and that no transitions at any finite temperature exist for $p\ge 2 d$; the critical temperature is also estimated. We study the magnetic properties of this model. We calculate the critical exponents' dependence on $p$; these exponents also satisfy a scaling relation. Some of the results were also found using the modified spin-wave theory and are in remarkable agreement with each other.Comment: 13 pages(LaTeX REVTeX), 2 figures not included (postscript files available on request), submitted to Phys.Rev.

A Guide for Policy, Practice and Patients on Wellbeing and Sickle Cell Disorder (SCD)

This guide is based on research examining the shielding experiences of people with sickle cell disorders (SCD) and parents of children with the condition during the COVID-19 pandemic. The aim was to improve NHS services for this population group. Services have duties under the Equality Act 2010 to ensure equity and tackle health inequalities. Since SCD disproportionately affects Black, Asian and Minority Ethnic (BAME) communities, there are also duties not to engage in direct or indirect racist discrimination, nor in harassment or victimization. It is important that anti-racist and anti-bias training is offered in all NHS services and cultural competency encouraged amongst all staff. Additionally, that conditions affecting the BAME population, like SCD, become a mandatory part of all nursing and medical educational and NHS training programmes

Orbital ordering in transition-metal compounds: I. The 120-degree model

We study the classical version of the 120-degree model. This is an attractive nearest-neighbor system in three dimensions with XY (rotor) spins and interaction such that only a particular projection of the spins gets coupled in each coordinate direction. Although the Hamiltonian has only discrete symmetries, it turns out that every constant field is a ground state. Employing a combination of spin-wave and contour arguments we establish the existence of long-range order at low temperatures. This suggests a mechanism for a type of ordering in certain models of transition-metal compounds where the very existence of long-range order has heretofore been a matter of some controversy.Comment: 40 pages, 1 eps fig; a revised version correcting a bunch of small error

Alternative analysis to perturbation theory

We develop an alternative approach to time independent perturbation theory in non-relativistic quantum mechanics. The method developed has the advantage to provide in one operation the correction to the energy and to the wave function, additionally we can analyze the time evolution of the system. To verify our results, we apply our method to the harmonic oscillator perturbed by a quadratic potential. An alternative form of the Dyson series, in matrix form instead of integral form, is also obtained.Comment: 12 pages, no figure

CMV matrices in random matrix theory and integrable systems: a survey

We present a survey of recent results concerning a remarkable class of unitary matrices, the CMV matrices. We are particularly interested in the role they play in the theory of random matrices and integrable systems. Throughout the paper we also emphasize the analogies and connections to Jacobi matrices.Comment: Based on a talk given at the Short Program on Random Matrices, Random Processes and Integrable Systems, CRM, Universite de Montreal, 200

A topological characterization of delocalization in a spin-orbit coupling system

We show that wavefunctions in a two-dimensional (2D) electron system with spin-orbit coupling can be characterized by a topological quantity--the Chern integer due to the existence of the intrinsic Kramers degeneracy. The localization-delocalization transition in such a system is studied in terms of such a Chern number description, which reproduces the known metal-insulator transition point. The present work suggests a unified picture for various known 2D delocalization phenomena based on the same topological characterization.Comment: RevTex, 12 pages; Two PostScript figure

Absence of spontaneous magnetic order at non-zero temperature in one- and two-dimensional Heisenberg and XY systems with long-range interactions

The Mermin-Wagner theorem is strengthened so as to rule out magnetic long-range order at T>0 in one- or two-dimensional Heisenberg and XY systems with long-range interactions decreasing as R^{-alpha} with a sufficiently large exponent alpha. For oscillatory interactions, ferromagnetic long-range order at T>0 is ruled out if alpha >= 1 (D=1) or alpha > 5/2 (D=2). For systems with monotonically decreasing interactions ferro- or antiferromagnetic long-range order at T>0 is ruled out if alpha >= 2D.Comment: RevTeX, 4 pages. Further (p)reprints available from http://www.mpi-halle.de/~theory ; v2: revised versio