Assessment of the Contribution of WorldView-2 Strategically Positioned Bands in Bracken fern (Pteridium aquilinum (L.) Kuhn) Mapping

In the eThekwini Metropolitan Area, mitigation of the Bracken fern (Pteridium aquilinum (L.) Kuhn) invasion within the KwaZulu-Natal Sandstone Sourveld (KZNSS) has been identified as a major environmental priority. To facilitate informed interventions, reliable Bracken fern spatial distribution is necessary. Earlier efforts to map the fern using lower spatial and spectral resolution imagery have been unsuccessful. Consequently, this study sought to determine the reliability of the “new generation” World View-2 (WV-2) image characterised by higher spatial and spectral resolution in delineating the fern invaded areas. The eight band WV2 image was atmospherically corrected and spectrally resized as the SPOT-5 wavebands, additional bands and all bands. The classification accuracy was compared to results from the SPOT-5 image. Results showed that classification based on WV-2s additional bands had superior classification accuracy than the rest of the categories. Furthermore, classification based on all the WV-2s bands and the traditional bands perfomed better than the SPOT-5 image in delineating areas covered by the fern. These findings indicate the value of of the “new generation” imagery characterised by higher spatial and spectral resolution in improving the accuracy of the fern invaded landscapes

Incarcerated students' experiences of UNISA’s open distance e-learning at one Medium Correctional Centre

Technology mediated pedagogies of the 21st century present new and unprecedented challenges for incarcerated tertiary students. The researchers, employing a qualitative exploratory research design, sought to explore the learning experiences of UNISA students incarcerated at Baviaanspoort Medium Correctional Centre. Six participants were sampled purposively and recruited to participate during a focus group interview. Qualitative content analysis revealed the ever-changing landscape of higher education due to the advent of digitised e-learning; the unique challenges encountered by incarcerated students studying at tertiary level; strategies for overcoming barriers associated with ODeL; and that lastly, in the context of imprisonment, student-centeredness is still primarily informed by a constructivist approach to ODL. The study concluded that students’ learning experiences, and by extension, academic success, can be enhanced provided learner support is augmented for incarcerated tertiary students

The DARC-null trait is associated with moderate modulation of NK cell profiles and unaltered cytolytic T cell profiles in black South Africans

The Duffy Antigen Receptor for Chemokines (DARC)-null trait, common among persons of African descent and associated with lower absolute neutrophil counts (ANCs), may be linked to increased risk to certain infections including HIV-1 but the underlying causes are poorly understood. We hypothesized that DARC-null-linked neutropenia may negatively impact neutrophil immunoregulatory modulation of other immune cells such as natural killer (NK) and CD8+ T cells leading to altered phenotype, functionality and homeostatic activity of these immune cells. HIV-1 uninfected (n = 20) and HIV-1 chronically infected (n = 19) participants were assessed using multi-parametric flow cytometry to determine NK and CD8+ T cell counts, phenotypic profiles, and cytokine production and degranulation. Annexin V and carboxyfluorescein succinimidyl ester (CFSE) staining were used to examine NK cell survival and NK cell and CD8+ T cell proliferation respectively. Participants were genotyped for the DARC-null polymorphism using allelic discrimination assays and ANCs were measured by full blood count. In HIV uninfected individuals, a reduction of total NK cell counts was noted in the absence of DARC and this correlated with lower ANCs. HIV uninfected DARC-null subjects displayed a less mature NK cell phenotype. However, this did not translate to differences in NK cell activation or effector functionality by DARC state. Whilst HIV-1 infected subjects displayed NK cell profiling that is typical of HIV infection, no differences were noted upon DARC stratification. Similarly, CD8+ T cells from HIV infected individuals displayed phenotypic and functional modulation that is characteristic of HIV infection, but profiling was unaffected by the DARC-null variant irrespective of HIV status. Overall, the data suggests that the DARC-null polymorphism and lower ANCs does not impede downstream cytolytic cell priming and functionality

CD8 lymphocytes mitigate HIV-1 persistence in lymph node follicular helper T cells during hyperacute-treated infection

HIV persistence in tissue sites despite ART is a major barrier to HIV cure. Detailed studies of HIV-infected cells and immune responses in native lymph node tissue environment is critical for gaining insight into immune mechanisms impacting HIV persistence and clearance in tissue sanctuary sites. We compared HIV persistence and HIV-specific T cell responses in lymph node biopsies obtained from 14 individuals who initiated therapy in Fiebig stages I/II, 5 persons treated in Fiebig stages III-V and 17 late treated individuals who initiated ART in Fiebig VI and beyond. Using multicolor immunofluorescence staining and in situ hybridization, we detect HIV RNA and/or protein in 12 of 14 Fiebig I/II treated persons on suppressive therapy for 1 to 55 months, and in late treated persons with persistent antigens. CXCR3(+) T follicular helper cells harbor the greatest amounts of gag mRNA transcripts. Notably, HIV-specific CD8(+) T cells responses are associated with lower HIV antigen burden, suggesting that these responses may contribute to HIV suppression in lymph nodes during therapy. These results reveal HIV persistence despite the initiation of ART in hyperacute infection and highlight the contribution of virus-specific responses to HIV suppression in tissue sanctuaries during suppressive ART

Optimising a couples-focused intervention to increase couples’ HIV testing and counselling using the person-based approach: a qualitative study in Kwa-Zulu Natal, South Africa

Objectives This qualitative study explored how to optimise a couples-focused intervention to promote couples HIV testing and counselling (CHTC). Setting Community setting in Kwa-Zulu Natal, South Africa. Participants Qualitative interviews were conducted with 20 couples who had participated in a couples-focused intervention and five staff members delivering the intervention. Partners were interviewed individually by researchers of the same gender. Intervention A couples-focused intervention comprised of two group sessions and four couples counselling sessions was previously shown to significantly increase uptake to CHTC in Kwa-Zulu Natal, South Africa. However, more than half of couples participating in the intervention still chose not to test together during follow-up. Analysis The transcripts were analysed using the table of changes from the person-based approach. Proposed optimisations were discussed with a community group to ensure the intervention was as persuasive and acceptable as possible. Results Many couples found it challenging to discuss CHTC with their partner due to an implied lack of trust. Optimisations to the intervention were identified to increase readiness to discuss CHTC, including education about serodiscordance, discussions about CHTC by peer mentors and open discussion of personal barriers to CHTC during couples’ counselling sessions. Additional training for staff in open questioning techniques could help them feel more comfortable to explore couples’ perceived barriers to CHTC, rather than advising couples to test. A logic model was developed to show anticipated mechanisms through which the optimised intervention would increase uptake to CHTC, including increasing knowledge, increasing positive outcome beliefs and managing negative emotions. Conclusions In-depth qualitative research informed optimisations to a couples-focused intervention for further evaluation in South Africa to encourage uptake to CHTC. Suggestions are made for optimal methods to gain open feedback on intervention experiences where participants may be reluctant to share negative views

Socio-Demographic Determinants of Condom Use Among Sexually Active Young Adults in Rural KwaZulu-Natal, South Africa

AIM: To investigate patterns, levels and socio-demographic determinants of condom use and consistency of use among young adults aged 15-24 years.BACKGROUND: Condoms are known to prevent HIV infection. However, HIV prevalence and incidence remain high.METHODS: This study was conducted in the Africa Centre Demographic Surveillance Area (ACDSA) in rural KwaZulu-Natal. Analysis focused on resident young adults aged 15-24 years in 2005. In univariable and multivariable analyses, determinants of condom use and consistency of use among 15-24 year olds were estimated using data collected in 2005. 'Ever' condom use was defined as the proportion who reported having used a condom; consistent use among those ever using as "always" using condoms with most recent partner in the last year.RESULTS: 3,914 participants aged 15-24 years reported ever having sex, of whom 52% reported condom use. Adjusting for age, sex, number of partners, residence of partner, partner age difference, type of partner and socio-economic status (SES), having an older partner decreased likelihood (aOR=0.69, p<0.01), while belonging to a household in a higher SES increased likelihood of ever using condoms (aOR=1.82, p<0.01). Being female (aOR=0.61 p<0.01) and having a regular partner (aOR=0.65 p<0.01) were independently associated with low consistent condom use.CONCLUSIONS: In this rural South African setting, condom use remains low, especially among females and with an older partner, situations commonly associated with increased HIV acquisition. Targeted supportive interventions to increase condom use need to be developed if HIV prevention programmes are to be successful