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Andrea K Daniels,1 Rudolph L Van Niekerk2 1School of Community Psycho-social Research (COMPRES), Faculty of Health Sciences, North West University, Potchefstroom, South Africa; 2Department of Human Movement Science, Faculty of Health Sciences, University of Fort Hare, Alice, South Africa Introduction: Attitudes, responses, and reactions of HIV-positive women in three sub-Saharan African regions toward a therapeutic exercise intervention, aimed to determine the presence of depression and low body self-image, were captured. This provided insight into body satisfaction and desire to exercise (Stage 1, n=60), body self-image and depression (Stage 2, n=60), and overall concerns around the often adverse side effects of antiretroviral treatment (ART). A program of therapeutic (specialty) exercise was developed for the experimental design (Stage 2), to quantify the psychological side effects of these variables. Methodology: Stage 1 constituted a qualitative exploration into attitudes and perceptions around ART, toxicity, health concerns, metabolic irregularities (lipodystrophy), body shape and size dissatisfaction, and cultural attitudes toward exercise. This stage deployed brief informal face-to-face interviews, based on the World Health Organization (WHO)/United Nations Fund for Population Activities (UNFPA) AIDS Inventory, in three sub-Saharan African regions (including provincial and district hospitals, nongovernmental organizations, voluntary counseling and testing/HIV and testing centers, and primary care outpatient clinics). Stage 2 of the study comprised a quantitative experimental design, conducted on a sample of HIV-positive women (mean age=39.0 years; mean years on ART=5.5; 86% black) in three selected HIV outpatient clinics in Johannesburg, South Africa. Data analysis: The collated data sets from both stages of the research were presented, analyzed, and interpreted (thematic analyses [Stage 1] and statistical analyses [Stage 2]) using the body self-image questionnaire and Beck’s depression inventory. Results: Stage 1 outlined participants’ concerns and reports around 1) body shape and size, including long-term effects of ART and 2) attitudes toward exercise, as a function of HIV status. Stage 2 represented pre- and posttest statistics, showing low statistical means for both the experiment and the control groups, with statistical significance for four out of nine items of subscales of body self-image questionnaire. Keywords: antiretroviral treatment, ART, body self-image, depression, functional cognition, lipodystrophy, therapeutic movement

The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015-2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015-2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha -1 y -1 ) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions 1-3 . Climate-driven vegetation models typically predict that this tropical forest 'carbon sink' will continue for decades 4,5 . Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53-0.79), in contrast to the long-term decline in Amazonian forests 6 . Therefore the carbon sink responses of Earth's two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature 7-9 . Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth's intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass 10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth's climate.