Adjusting HIV Prevalence Estimates for Non-participation: an Application to Demographic Surveillance

Introduction: HIV testing is a cornerstone of efforts to combat the HIV epidemic, and testing conducted as part of surveillance provides invaluable data on the spread of infection and the effectiveness of campaigns to reduce the transmission of HIV. However, participation in HIV testing can be low, and if respondents systematically select not to be tested because they know or suspect they are HIV positive (and fear disclosure), standard approaches to deal with missing data will fail to remove selection bias. We implemented Heckman-type selection models, which can be used to adjust for missing data that are not missing at random, and established the extent of selection bias in a population-based HIV survey in an HIV hyperendemic community in rural South Africa.

Methods: We used data from a population-based HIV survey carried out in 2009 in rural KwaZulu-Natal, South Africa. In this survey, 5565 women (35%) and 2567 men (27%) provided blood for an HIV test. We accounted for missing data using interviewer identity as a selection variable which predicted consent to HIV testing but was unlikely to be independently associated with HIV status. Our approach involved using this selection variable to examine the HIV status of residents who would ordinarily refuse to test, except that they were allocated a persuasive interviewer. Our copula model allows for flexibility when modelling the dependence structure between HIV survey participation and HIV status.

Results: For women, our selection model generated an HIV prevalence estimate of 33% (95% CI 27–40) for all people eligible to consent to HIV testing in the survey. This estimate is higher than the estimate of 24% generated when only information from respondents who participated in testing is used in the analysis, and the estimate of 27% when imputation analysis is used to predict missing data on HIV status. For men, we found an HIV prevalence of 25% (95% CI 15–35) using the selection model, compared to 16% among those who participated in testing, and 18% estimated with imputation. We provide new confidence intervals that correct for the fact that the relationship between testing and HIV status is unknown and requires estimation.

Conclusions: We confirm the feasibility and value of adopting selection models to account for missing data in population-based HIV surveys and surveillance systems. Elements of survey design, such as interviewer identity, present the opportunity to adopt this approach in routine applications. Where non-participation is high, true confidence intervals are much wider than those generated by standard approaches to dealing with missing data suggest.

O caso de um jovem autista: uma história, um percurso, uma vida

Dissertação de mest., Psicologia da Educação, Universidade do Algarve, 2007

How can economic and political liberalisation improve financial development in African countries?

The objective of this paper is to study the interactions between Economic liberalisation, Political liberalisation and Financial development in African countries. More specifically, we seek to establish the impact of Economic, Political and institutional openness on financial deepening. The empirical approach will be two-step procedure, first using a difference in difference method to show the various aspect of financial liberalisation on economic and political freedom while the second step will be using panel data techniques from period 1990 to 2005. The estimation results can be summarised as the following, first, Economic and financial liberalisation did account significantly for the financial development performance. While political stability show a positive overall effect on financial development, the association with Political freedom is consistent only after controlling the endogeneity of Political freedom on financial development. This result indicates that the transformation of the political and economic environment has improved the performance of the financial sector.

Did We Fail? (Counter-)Transference in a Qualitative Media Research Interview

Drawing on Joke Hermes’ (2006) account of a troubling interview, this article reproduces and reflects on passages from a qualitative interview with a user of a social networking site that was experienced as uncomfortable by both interviewee and interviewer (myself). The psychoanalytic concept of (counter-)transference is used to analyse the possible processes that led to the emergence of two narratives by the interviewee and interviewer and resulted in an unsuccessful research encounter. It is suggested that the analysis of the interview narratives may contribute to Wanda S. Pillow’s (2003) notion of an ‘uncomfortable reflexivity’. It may further add to methodological discussions of the interview in media research by placing an emphasis on a complex theory of the subject and intersubjective dynamics.

Climate change and visual imagery

Many actors—including scientists, journalists, artists, and campaigning organizations—create visualizations of climate change. In doing so, they evoke climate change in particular ways, and make the issue meaningful in everyday discourse. While a diversity of climate change imagery exists, particular types of climate imagery appear to have gained dominance, promoting particular ways of knowing about climate change (and marginalizing others). This imagery, and public engagement with this imagery, helps to shape the cultural politics of climate change in important ways. This article critically reviews the nascent research area of the visual representations of climate change, and public engagement with visual imagery. It synthesizes a diverse body of research to explore visual representations and engagement across the news media, NGO communications, advertising, and marketing, climate science, art, and virtual reality systems. The discussion brings together three themes which occur throughout the review: time, truth, and power. The article concludes by suggesting fruitful directions for future research in the visual communication of climate change.

Development of broad-spectrum human monoclonal antibodies for rabies post-exposure prophylaxis

Currently available rabies post-exposure prophylaxis (PEP) for use in humans includes equine or human rabies immunoglobulins (RIG). The replacement of RIG with an equally or more potent and safer product is strongly encouraged due to the high costs and limited availability of existing RIG. In this study, we identified two broadly neutralizing human monoclonal antibodies that represent a valid and affordable alternative to RIG in rabies PEP. Memory B cells from four selected vaccinated donors were immortalized and monoclonal antibodies were tested for neutralizing activity and epitope specificity. Two antibodies, identified as RVC20 and RVC58 (binding to antigenic site I and III, respectively), were selected for their potency and broad-spectrum reactivity. In vitro, RVC20 and RVC58 were able to neutralize all 35 rabies virus (RABV) and 25 non-RABV lyssaviruses. They showed higher potency and breath compared to antibodies under clinical development (namely CR57, CR4098, and RAB1) and commercially available human RIG. In vivo, the RVC20–RVC58 cocktail protected Syrian hamsters from a lethal RABV challenge and did not affect the endogenous hamster post-vaccination antibody response.

Suite de la Clef, ou Journal historique sur les matieres du tems

1757/01 (T81)-1757/06.

Suite de la Clef, ou Journal historique sur les matieres du tems

1757/07 (T82)-1757/12.

Le Monde, son origine, et son antiquité . De l'âme et de son immortalité. Essai sur la chronologie. Seconde édition, corrigée avec soin

Comprend : De l'ame et de son immortalité ; Essai sur la chronologie