Absolute continuity and spectral concentration for slowly decaying potentials

We consider the spectral function $\rho(\mu)$ $(\mu \geq 0)$ for the Sturm-Liouville equation $y^{''}+(\lambda-q)y =0$ on $[0,\infty)$ with the boundary condition $y(0)=0$ and where $q$ has slow decay $O(x^{-\alpha})$ $(a>0)$ as $x\to \infty$. We develop our previous methods of locating spectral concentration for $q$ with rapid exponential decay (JCAM 81 (1997) 333-348) to deal with the new theoretical and computational complexities which arise for slow decay

Extensions of a New Algorithm for the Numerical Solution of Linear Differential Systems on an Infinite Interval

This paper is part of a series of papers in which the asymptotic theory and appropriate symbolic computer code are developed to compute the asymptotic expansion of the solution of an n-th order ordinary differential equation. The paper examines the situation when the matrix that appears in the Levinson expansion has a double eigenvalue. Application is made to a fourth-order ODE with known special function solution

Building a future...An exploration of the contribution of educational provision to clients’ well-being at Southwark Day Centre for Asylum Seekers

This research project builds on previous work, ‘Beneath the Surface’ (Cogo, Inman, McCormack, Rogers 2018) which focussed on how clients at Southwark Day Centre for Asylum Seekers (SDCAS) understood and evaluated their well-being. One of the areas touched on in that research was the role of educational activities in developing the well-being of clients. This report describes in depth the ways in which the educational provision offered in the centre contributes to the well-being of clients and how this contribution might be enhanced. The report focuses on two areas of education provision; gardening and storytelling and explains how they contribute to the well-being of the clients. The interview data confirms that the activities in these two areas help to build clients’ psychological, physical and social resources and have a positive effect on how clients feel and how they function in the world. The report ends with recommendations as to how SDCAS might ensure that gardening and storytelling continue to benefit the well-being of clients and also as to what might be put in place to strengthen the activities

Stories from lockdown: the impact of the Covid19 pandemic on the well-being of clients at Southwark Day Centre for Asylum Seekers (SDCAS)

The report describes the findings of research on how the Covid 19 related lockdowns affected the well-being of clients at the Southwark Day Centre for Asylum Seekers. A small number of clients were interviewed about the practical issues of housing, food, money and about their physical and mental health during the periods of lockdowns. They were also asked about support from the Southwark Day Centre for Asylum Seekers. The report describes the experiences of these clients between March 2020 and March 202

Absorption coefficient dependent non-linear properties of thin film luminescent solar concentrators

This research article studied absorption coefficient dependent losses and efficiency of thin film luminescent solar concentrator (LSC). The optimum absorption coefficient was determined by fabricating red dye doped thin film LSCs with varying absorption coefficients of 24–202 cm-1. The optical, electrical, and ray-trace model predicted results were compared to establish the optimum absorption coefficient for fabricated thin film LSCs. The optical and electrical efficiencies of thin film LSCs are a function of absorption coefficient; follow linearly at lower values, gradually becoming non- linear at higher values of absorption coefficient which restricts the overall efficiency. The multi layered ray–trace model predicted results deviated from the experimental results at high absorption coefficient. Non-linearity was introduced by losses mechanism of re-absorption, resonant energy transfer (RET), and scattering in thin film LSCs. Re-absorption losses were found to be dependent on optical path-length and absorption coefficient of thin film. They were identified and quantified through locally collected emission and optical path-length in thin film LSCs. Re-absorption losses caused a red shift in emission peak by ≈ 20 nm as the absorption coefficient increased from 24 to 202 cm-1. RET decreased fluorescence life time of dye from 5 ns to 2 ns for the absorption coefficient increased from 24–202 cm-1. These absorption coefficient dependent losses limit the optical and electrical efficiency of thin film LSC devices, and compared with bulk LSC

Recent advances in pre-exposure prophylaxis for HIV

Although pre-exposure prophylaxis (PrEP)-the use of antiretroviral drugs by non-infected people to prevent the acquisition of HIV-is a promising preventive option, important public health questions remain. Daily oral emtricitabine (FTC)-tenofovir disoproxil fumarate (TDF) is highly efficacious in preventing the acquisition of HIV in people at risk as a result of a range of different types of sexual exposure. There is good evidence of efficacy in women and men, and when men who have sex with men use event based dosing. Studies have been conducted in several countries and epidemics. Because adherence to this treatment varies greatly there are questions about its public health benefit. Oral FTC-TDF is extremely safe, with minimal impact on kidney, bone, or pregnancy outcomes, and there is no evidence that its effectiveness has been reduced by risk compensation during open label and programmatic follow-up. It is too early to assess the impact of this treatment on the incidence of sexually transmitted infections (STIs) at a population level. Many challenges remain. Access to pre-exposure prophylaxis is limited and disparities exist, including those governed by race and sex. Different pricing and access models need to be explored to avoid further widening inequalities. The optimal combination prevention program needs to be defined, and this will depend on local epidemiology, service provision, and cost effectiveness. This review updates the evidence base for pre-exposure prophylaxis regarding its effectiveness, safety, and risk compensation