Information flow, artificial phonology and typology

In the context Artificial Grammar Learning (AGL) experiments, it is possible to quantify how effectively a stimulus has conveyed information and specifically the information the experimenter thinks it was designed to convey. At the most basic level, this can be done if one has access to the response variability of independent responses to the same stimulus (or subparts of the stimulus). The variability of these responses serves as an index of the amount of information that flows from the source of the stimulus to the perceiver. Quantifying information flow in this way, it is shown that under conditions where participants learn a ‘natural’ but not an ‘unnatural’ rule there are asymmetries in entropic quantities under the different conditions

Consonant harmony, disharmony, memory and time scales

I argue that properties of memory offer an appropriate grounding for a number of characteristics of long distance consonantal co-occurrence restrictions whose basis had so far remained unclear

Family planning methods among women in a vaginal microbicide feasibility study in rural KwaZulu-Natal, South Africa

This study investigated contraceptive use among women in rural KwaZulu-Natal, South Africa. Of 866 sexually active women not intending pregnancy and screened for a microbicide feasibility study, 466 (54%) reported currently using modern contraceptives: injectables (31%), condoms (12%), sterilization (60%) and pills (4%). Multivariable logistic regression analyses revealed statistically significantly higher odds of current contraceptive use among married vs. engaged/unmarried women (aOR 1.64), multiparous vs. nulliparous (aOR 4.45) and women who completed secondary education or above vs. primary or less (aOR 1.64). Significantly lower odds of use were observed among women aged 40+ vs. age 15-19 (aOR 0.38). Age, marital status, education level and parity were associated with different contraceptive method choices. Among 195 women followed longitudinally for 9 months, contraceptive use increased significantly from 56% to 70%, largely due to increased condom use (15% to 28%). Results highlight the importance of integrating family planning and HIV/STI prevention counseling and informing promotion of further contraceptive uptake among women not intending pregnancy

Microbicides, sexuality and sexual health in KwaZulu-Natal, South Africa

There is an urgent need for additional HIV prevention options for women. Evidence supporting the benefit of microbicides in reducing the risk of vaginally acquired HIV acquisition has provided a major breakthrough. Despite the wealth of evidence supporting microbicide acceptability in Africa, there are still gaps in our understanding about how women will incorporate microbicides into their everyday lives. In this thesis I examine whether vaginal microbicides are compatible with socio-cultural norms regarding sexuality and sexual health in a predominantly rural area of KwaZulu-Natal, South Africa. Using qualitative and quantitative data collected as part of the MDP 301 clinical trial at the Africa Centre, I adopt a mixed methods approach to evaluate microbicide acceptability from a cultural perspective. I explore the compatibility of microbicides with socio-cultural norms that relate to intravaginal cleansing, intravaginal insertion, love medicines and sexual communication. I found that the desired effects of using intravaginal insertions to enhance sexual pleasure are compatible with the experiences of using microbicides; that contemporary socio-cultural norms relating to sexual communication in the context of the HIV epidemic are compatible with the introduction of microbicides; that women distanced microbicides from ‘love medicines’ in terms of separating microbicides from the supernatural; and, finally, that postcoital intravaginal cleansing practices could undermine a microbicides roll out programme if we fail to address these practices. Overall I found that microbicides are compatible with socio-cultural norms relating to intravaginal insertion and sexual communication, but they may be less compatible with norms relating to intravaginal cleansing and love medicines. While incompatibility with socio-cultural norms raises challenges for intravaginal cleansing, the fact that love medicines are incompatible with microbicides could be advantageous for their introduction. Ultimately these findings have implications for future research and service delivery, as well as offering insights into microbicides, sexuality and gender equality

Pre-exposure prophylaxis (PrEP) uptake and adherence experiences of gay and bisexual men who engage in chemsex: A qualitative study

BACKGROUND: Pre-exposure prophylaxis (PrEP) is the use of HIV antiretroviral medications to reduce the risk of HIV acquisition. PrEP is highly effective when used during periods of potential HIV exposure. Gay and bisexual men (GBM) who engage in unprotected chemsex (without condoms or PrEP) are at high-risk of acquiring HIV. Substance use has been shown to detrimentally impact on the effective use of HIV treatment among GBM living with HIV. This study aims to qualitatively explore PrEP uptake and adherence among GBM who engage in chemsex in the United Kingdom. METHODS: Nineteen semi-structured in-depth telephone interviews were conducted with self-identifying HIV-negative GBM who reported recently engaging in chemsex and currently using or had recently used PrEP. We explored the ways in which chemsex influenced GBM's motivation to use, access to and effective use of PrEP. Interviews were audio recorded, transcribed, and coded using thematic analysis. RESULTS: Most of the men identified as gay, were of white ethnicity and had a median age of 41. Eighteen men were still using PrEP at the time of the interview and most used daily dosing. The perception of being at high risk of HIV acquisition was a key factor influencing PrEP initiation and after initiation, continued to influence high levels of adherence which was reported by the majority of participants. The few individuals who reported sub-optimal adherence, explained that psychosocial stressors or periods of impaired mental health led to more frequent or intense chemsex sessions, which in turn contributed to occasional non-adherence. Most participants used a variety of strategies to help them adhere, which included restricting the amount or intensity of chemsex they engaged in, strategic placement of PrEP and external triggers to remind them to take PrEP. CONCLUSIONS: In this study, the majority of GBM who engaged in chemsex, initiated PrEP in recognition of their potential risk of HIV acquisition and reported high levels of PrEP adherence. They used multiple strategies to support effective PrEP access and adherence. These findings support a growing body of evidence that PrEP is a viable prevention tool for GBM who engage in chemsex, and that chemsex does not negatively impact PrEP adherence