Modelling the demographic impact of HIV/AIDS in South Africa and the likely impact of interventions

This paper describes an approach to incorporating the impact of HIV/AIDS and the effects of HIV/AIDS prevention and treatment programmes into a cohort component projection model of the South African population. The modelled HIV-positive population is divided into clinical and treatment stages, and it is demonstrated that the age profile and morbidity profile of the HIV-positive population is changing significantly over time. HIV/AIDS is projected to have a substantial demographic impact in South Africa. Prevention programmes - social marketing, voluntary counselling and testing, prevention of mother-to-child transmission and improved treatment for sexually transmitted diseases - are unlikely to reduce AIDS mortality significantly in the short term. However, more immediate reductions in mortality can be achieved when antiretroviral treatment is introduced.antiretroviral treatment, demographic impact, HIV/AIDS prevention, simulation model, South Africa

Origin of the Mott Gap

We show exactly that the only charged excitations that exist in the strong-coupling limit of the half-filled Hubbard model are gapped composite excitations generated by the dynamics of the charge $2e$ boson that appears upon explicit integration of the high-energy scale. At every momentum, such excitations have non-zero spectral weight at two distinct energy scales separated by the on-site repulsion $U$. The result is a gap in the spectrum for the composite excitations accompanied by a discontinuous vanishing of the density of states at the chemical potential when $U$ exceeds the bandwidth. Consequently, we resolve the long-standing problem of the cause of the charge gap in a half-filled band in the absence of symmetry breaking.Comment: 6 pages, 2 figures: Expanded Published versio

Kinds of Self-Knowledge in Ancient Thought

This chapter explores the topic of self-knowledge in ancient thought, asking in particular what the ancient concept (or concepts) of knowing oneself amounts to. The chapter begins by contrasting the issues which occupy ancient and contemporary discussions of self-knowledge, and the obvious points of continuity and discontinuity between the two. The author isolates two forms of self-knowledge: cognitive self-knowledge or knowledge of one’s own mental states, and dispositional self-knowledge or knowledge of one’s moral or intellectual dispositions, and traces the treatment of these forms of self-knowledge in the works of Plato, Aristotle, Hellenistic philosophers, and Plotinus. In the course of discussing the texts of each thinker or school, and the relevant scholarship, this chapter also canvasses the ways in which the chapters in the rest of this volume seek to engage with some of the problems or issues that have emerged

Says Who? Modes of Speaking in the Euthydemus

With very few exceptions, the relatively small number of scholars who have lavished attention on Plato’s Euthydemus have found it fertile soil in two respects. For some, it is a compilation of fallacies committed by the sophistic brothers, Euthydemus and Dionysodorus, designed to serve as an introductory sourcebook of bad argument—a forerunner to Aristotle’s Sophistici Elenchi [Robinson 1942; Sprague 1962; Hawtrey 1981]. 1 For others, it contains a significant contribution to Platonic ethics by way of a compressed and vexing argument for the view that compared to other purported goods (e.g., health and wealth), wisdom is the only good ‘in itself’ (280b–282a) (e.g. Irwin [1995: 32–3, 73n, 118–20]; Russell [2005: 16–47]). 2 By contrast, in her various papers and lectures on the Euthydemus, M.M. McCabe discerns a much wider variety of topics at issue in the dialogue (e.g., self-knowledge, a rejection of consequentialism), and while focusing on specific passages, has situated her interpretations within a view of the text as a whole. 3 So, too, in the target paper for this volume, ‘First Chop Your Logos … Socrates and the Sophists on Logic, Language, and Development’, McCabe [2021a] argues that a close reading of several passages reveals the sophistic brothers’ deployment of a formidable position or view on the relation of language to the world that presents a serious challenge to Socrates’ assumptions about statements and saying, and that Plato’s response to the challenge emerges from consideration of different elements at play throughout the whole dialogue. Due to limited space, I will restrict myself in this introduction to a sketch of the structure of the Euthydemus, for those unfamiliar with it, and an outline of McCabe’s reading of the sophistic challenge and Plato’s response to it, occasionally gesturing towards key claims or objections advanced in the commentaries in this volume (though I have generally been unable to note McCabe’s [2021b] detailed responses in her reply piece, ‘Who’s Who and What’s What’)

Aging Out of the Foster Care System to Adulthood: Findings, Challenges, and Recommendations

To assess and ultimately help meet the needs of youth who age out of foster care in the United States, the Joint Center Health Policy Institute (JCHPI) -- with support from the Robert Wood Johnson Foundation and in partnership with the Black Administrators in Child Welfare Inc. (BACW) -- conducted reconnaissance on the unmet needs of these youth. This project was undertaken to guide the Robert Wood Johnson Foundation in thinking about steps they might take to help meet the needs of youth who age out of foster care in this country. Conducting a literature review, a telephone survey, and listening sessions enabled us to develop insights into the workings of the foster care system and the experiences of youth while in the system and when aging out of it

Implementation of in Process Surface Metrology for R2R Flexible PV Barrier Films

Thin functional barrier layers of aluminum oxide (Al2O3) that are used particularly in photovoltaic (PV) modules to prevent the possibility of water vapor ingress should be applied over the entire PV surface without any defects. However, for barrier layer thicknesses within the sub-micrometer range (up to 50 nm) produced through the atomic layer deposition (ALD) method, it is common for defects to occur during the production process. To avoid defective barriers from being incorporated in the final PV unit, defects need to be detected during the barrier production process. In this paper, the implementation of in process inspection system capable of detecting surface defects such as pinholes, scratches, or particles down to a lateral size of 3 μm and a vertical resolution of 10 nm over a 500 mm barrier width is presented. The system has a built-in environmental vibration compensation capability, and can monitor ALD-coated films manufactured using roll-to-roll (R2R) techniques. Ultimately, with the aid of this in process measurement system, it should be possible to monitor the coating surface process of large-area substrates, and if necessary, carry out remedial work on the process parameters

Wavelength Scanning Interferometry for PV Production In-line Metrology

Flexible PV modules are manufactured using roll to roll (R2R) technology. These modules require a flexible barrier material to prevent water vapor ingress

Corrigendum: an overview of MicroRNAs as biomarkers of ALS

A Corrigendum on An Overview of MicroRNAs as Biomarkers of ALS by Joilin, G., Leigh, P. N., Newbury, S. F., and Hafezparast, M. (2019). Front. Neurol. 10:186. doi: 10.3389/fneur.2019.00186 In the original article, there was a mistake in Table 1 as published. Some of the miRNAs listed in the table were incorrectly placed in the wrong column and/or row. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated

The interaction between HIV and other sexually transmitted infections in South Africa: a model-based evaluation

Includes bibliographical references.Sexually transmitted infections (STIs) have been shown to increase the probability of HIV transmission, but there remains much uncertainty regarding the role of STI treatment in HIV prevention. This thesis aims to develop a mathematical model to estimate the prevalence of STIs in South Africa, the contribution of STIs to the spread of HIV, and the effects of changes in sexual behaviour and changes in STI treatment. A deterministic model is developed to simulate the transmission of HIV and six other STIs (syphilis, genital herpes, chancroid, gonorrhoea, chlamydial infection and trichomoniasis), as well as the incidence of bacterial vaginosis and vaginal candidiasis in women. The model is fitted to national HIV prevalence survey data, STI prevalence data from sentinel surveys and data from sexual behaviour surveys, using Bayesian techniques. Model results suggest that South Africa has some of the highest STI prevalence levels in the world, but that certain STIs – notably syphilis, chancroid, gonorrhoea and trichomoniasis – have declined in prevalence since the mid-1990s, following the introduction of syndromic management programmes and increases in condom use. STIs account for more than half of new HIV infections, and genital herpes is the most significant STI promoting the transmission of HIV. Syndromic management programmes reduced HIV incidence in South Africa by 3-10% over the decade following their introduction (1994-2004). Further reductions in HIV incidence could be achieved by promoting patient-initiated treatment of genital herpes, by addressing rising levels of drug resistance in gonococcal isolates, and by encouraging prompt health seeking for STIs. Concurrent partnerships are a major factor driving HIV transmission, accounting for 74-87% of new HIV infections over the 1990-2000 period. Halving unprotected sex in non-spousal relationships would reduce HIV incidence over the 2010 -2020 period by 32-43%. This thesis contributes to the understanding of HIV/AIDS epidemiology in South Africa by quantifying the contribution of various behavioural and biological factors to HIV transmission. This thesis also high lights several opportunities for reducing the future incidence of HIV. In addition, this thesis advances the assessment of uncertainty in STI models by proposing a Bayesian approach to incorporating sexual behaviour data and STI prevalence data into the parameter estimation proces