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Publication History View all

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    ABSTRACT: While research now highlights that men who have sex with men (MSM) in places such as South Africa are at particular risk of HIV infection, left relatively unexplored are potential relationships between one of the most pressing social issues affecting peri-urban MSM - namely homophobic stigma - and sexual risk-taking behaviour. Drawing on research from the Ukwazana baseline study of 316 township MSM in Cape Town we examine how homophobic stigma relates to psychosocial factors such as depression and self-efficacy and the risk activity of unprotected anal intercourse (UAI). By deploying cross-sectional association models, we examine a series of relationships between these variables and offer evidence to suggest that HIV prevention programmes aimed at sexual minority groups should be mindful of potentially complex relationships between social stigmas such as homophobia and sexual risk-taking behaviour.
    AIDS Care 12/2013;
  • Conservation Biology 09/2013;
  • [show abstract] [hide abstract]
    ABSTRACT: Abstract Men who have sex with men (MSM) in South Africa remain at particular risk of HIV infection. The Ukwazana baseline survey is the first to explore this risk in relation to psychological factors associated with unprotected anal intercourse (UAI). A cohort of 316 MSM from township peri-urban Cape Town took part in the survey. The survey found that 55.2% had engaged in UAI over the preceding 6 months. Depression was significantly associated with UAI. Respondents with self-efficacy scores less than two standard deviations above the mean were also more likely to have engaged in UAI. A Sobel test for mediation highlighted that the depression-UAI association was partially mediated by self-efficacy, indicating that most of the effect of depression on UAI was not covarying with self-efficacy. This study, therefore, highlights that both depression and self-efficacy should be considered factors to be addressed in HIV-prevention programmes aimed at peri-urban MSM.
    AIDS Care 02/2013;
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    ABSTRACT: This paper presents the results of empirical research on Montserrat, in the British West Indies, undertaken in 2008–2010. It highlights the challenges of managing a crisis that evolved from acute to chronic over a period of fifteen years. In particular, the paper considers the evolution of science and policy over a period of fifteen years in its social and cultural context. It discusses the relationship between different types of evolving knowledges, and the interaction between them. Finally, a reflexive model is introduced to draw attention to some of the challenges of managing the science–policy interface under high uncertainty and high stakes.
    Environmental Science & Policy 01/2013;
  • [show abstract] [hide abstract]
    ABSTRACT: This article considers the complex ways volunteer outreach workers can frame their engagement with a community-based HIV prevention programme for South African township MSM. Drawing on research conducted during the Ukwazana programme in Cape Town it begins by exploring limitations towards MSM participation with programme facilitators (namely previous feelings of mistrust and community homophobia) and strategies developed to offset these concerns. It then considers how great care must also be taken to appreciate how volunteers from marginalised groups can frame training as a key condition for participation. To understand this it is therefore necessary for facilitators to acknowledge a number of additional concerns. These include community status, a lack of bonding social capital between volunteers and a highly developed from of critical consciousness by volunteers regarding HIV prevention possibilities. This article therefore suggests that effort to initially engage marginalised communities must also be met with effort to understand the complex ways volunteers relate to other MSM and to each other.
    AIDS and Behavior 08/2012;
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    ABSTRACT: Sugarcane combustion generates fine-grained particulate that has the potential to be a respiratory health hazard because of its grain size and composition. In particular, conversion of amorphous silica to crystalline forms during burning may provide a source of toxic particles. In this study, we investigate and evaluate the toxicity of sugarcane ash and bagasse ash formed from commercial sugarcane burning. Experiments to determine the main physicochemical properties of the particles, known to modulate biological responses, were combined with cellular toxicity assays to gain insight into the potential reactions that could occur at the particle-lung interface following inhalation. The specific surface area of the particles ranged from ∼16 to 90 m(2) g(-1) . The samples did not generate hydroxyl- or carbon-centered radicals in cell-free tests. However, all samples were able to 'scavenge' an external source of hydroxyl radicals, which may be indicative of defects on the particle surfaces that may interfere with cellular processes. The bioavailable iron on the particle surfaces was low (2-3 μmol m(-2) ), indicating a low propensity for iron-catalyzed radical generation. The sample surfaces were all hydrophilic and slightly acidic, which may be due to the presence of oxygenated (functional) groups. The ability to cause oxidative stress and membrane rupture in red blood cells (hemolysis) was found to be low, indicating that the samples are not toxic by the mechanisms tested. Cytotoxicity of sugarcane ash was observed, by measuring lactate dehydrogenase release, after incubation of relatively high concentrations of ash with murine alveolar macrophage cells. All samples induced nitrogen oxide release (although only at very high concentrations) and reactive oxygen species generation (although the bagasse samples were less potent than the sugarcane ash). However, the samples induced significantly lower cytotoxic effects and nitrogen oxide generation when compared with the positive control. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
    Environmental Toxicology 03/2012;
  • [show abstract] [hide abstract]
    ABSTRACT: The relation of structural responses to underlying functional processes at the landscape scale helps develop our understanding of geomorphological phenomena at the coastline. This paper demonstrates how a habitat map derived from remotely sensed imagery was used as the basis for the development of an explanatory model to investigate factors influencing the linearity of alternating carbonate sand and seagrass patches on a reef flat in the Seychelles, western Indian Ocean. In combination with techniques established in landscape ecology for interrogating broad scale processes and spatial statistical procedures that bring geography explicitly into the analysis, an emergent framework for the quantification and investigation of geomorphological processes is illustrated. The combined influence of adjacent spur and groove amplitude and incident wave power accounted for 81% of the variation in sand and seagrass patch linearity across the habitat map. A series of steps in model development are examined, including observation, measurement, experimentation and interpretation. These steps both define and permit an empirical approach to geomorphology and the case study highlights how each can be achieved by adopting an interdisciplinary framework.
    Continental Shelf Research 01/2011;
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    ABSTRACT: Volcanic eruptions are commonly preceded, accompanied, and followed by variations of a number of detectable geophysical and geochemical manifestations. Many remote sensing techniques have been applied to tracking anomalies and eruptive precursors, and monitoring ongoing volcanic eruptions, offering obvious advantages over in situ techniques especially during hazardous activity. Whilst spaceborne instruments provide a distinct advantage for collecting data remotely in this regard, they still cannot match the spatial detail or time resolution achievable using portable imagers on the ground or aircraft. Hand-held infrared camera technology has advanced significantly over the last decade, resulting in a proliferation of commercially available instruments, such that volcano observatories are increasingly implementing them in monitoring efforts. Improved thermal surveillance of active volcanoes has not only enhanced hazard assessment but it has contributed substantially to understanding a variety of volcanic processes. Drawing on over a decade of operational volcano surveillance in Italy, we provide here a critical review of the application of infrared thermal cameras to volcano monitoring. Following a summary of key physical principles, instrument capabilities, and the practicalities and methods of data collection, we discuss the types of information that can be retrieved from thermal imagery and what they have contributed to hazard assessment and risk management, and to physical volcanology. With continued developments in thermal imager technology and lower instrument costs, there will be increasing opportunity to gather valuable observations of volcanoes. It is thus timely to review the state of the art and we hope thereby to stimulate further research and innovation in this area.
    Earth-Science Reviews 01/2011;
  • [show abstract] [hide abstract]
    ABSTRACT: The ~74 ka Youngest Toba Tuff (YTT) super-eruption of Toba volcano, Northern Sumatra, was the largest eruption of the Quaternary (magnitude M= 8.8) and injected massive quantities of volcanic gases and ash into the stratosphere. YTT deposits covered at least 40,000,000 km2 of Southeast Asia and are preserved in river valleys across peninsular India and Malaysia, and in deep-sea tephra layers in the Indian Ocean, Bay of Bengal and South China Sea. Initial studies hypothesized the eruption caused immediate and substantial global cooling during the ~ 1 kyr between Dansgaard-Oeschger events 19 and 20 which devastated ecosystems and hominid populations. A more recent review argues against severe post-YTT climatic deterioration and cannot find clear evidence for considerable impacts on ecosystems or bio-diversity. The determination of the eruptive parameters is crucial in this issue to document the eruption and understand the potential impacts from future super-volcanic eruptions. Volcanic ash deposits can offer dramatic insights into key eruptive parameters, including magnitude, duration and plume height. The composition and shape of volcanic ashes can be used to interpret physical properties of an erupting magma and tephra transport, while textural characteristics such as grain roughness and surface vescicularity can provide insights into degassing history, volatile content and explosive activity of the volcano. We present a stratigraphic and sedimentological analysis of YTT deposits in stratified contexts at three localities in India, at two sites in Peninsular Malaysia, and at several localities around Lake Toba and on Samosir Island, Sumatra. These sites offer excellent constraints on the spatial distribution of YTT deposits which can be used to infer dispersal directions of the cloud, and provide insights into environmental controls on preservation of tephra beds. The research aims at a systematic interpretation of the Toba tephra to understand the volcanic processes and environmental impacts of the largest known Quaternary volcanic eruption.
    AGU Fall Meeting Abstracts. 11/2010; -1:2363.
  • [show abstract] [hide abstract]
    ABSTRACT: Debate on the values that underpin conservation science is rarely based on empirical analysis of the values conservation professionals actually hold. We used Q methodology to investigate the values held by international conservation professionals who attended the annual Student Conference in Conservation Science at the University of Cambridge (U.K.) in 2008 and 2009. The methodology offers a quantitative means of examining human subjectivity. It differs from standard opinion surveys in that individual respondents record the way they feel about statements relative to other statements, which forces them to focus their attention on the issues they believe are most important. The analysis extracts the diverse viewpoints of the respondents, and factor analysis is used to reduce the viewpoints to a smaller set of factors that reflect shared ways of thinking. The junior conservation professionals attending the conference did not share a unifying set of core values; rather, they held a complex series of ideas and a plurality of opinions about conservation and how it should be pursued. This diversity of values empirically challenges recent proposals for conservation professionals to unite behind a single philosophy. Attempts to forge an artificial consensus may be counterproductive to the overall goals conservation professionals are pursuing.
    Conservation Biology 10/2010; 25(2):285-94.
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