16 Works

Association of chronic inflammation and accelerated atherosclerosis among an indigenous black population with chronic kidney disease

Muzamil Olamide Hassan, Therese Dix-Peek, Raquel Duarte, Caroline Dickens, Sagren Naidoo, Ahmed Vachiat, Sacha Grinter, Pravin Manga & Saraladevi Naicker
Introduction: Inflammation plays a major role in the development of atherosclerosis and cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. Toll-like receptor-4 (TLR4) is a major receptor for lipopolysaccharides (endotoxin) and other ligands involved in the pathogenesis of inflammation. We determined whether endotoxin levels and the presence of TLR4 polymorphisms are associated with markers of inflammation and atherosclerosis among South African CKD patients. Materials and methods: Endotoxin, lipopolysaccharide binding protein (LBP), serum CD14...

Data from: Glucocorticoid levels predict subsequent social tactic in females of a facultatively social mammal

Davina Hill, Neville Pillay & Carsten Schradin
Facultatively social species, in which individuals can switch between group- and solitary-living tactics, offer an opportunity to shed light on proximate mechanisms underlying alternative life histories. Promising hormonal mediators of social tactic include glucocorticoids, which control energy allocation and are negatively related to body condition, and testosterone which regulates numerous social behaviours. Here, we investigated hormonal profiles associated with social tactic in eight generations of free-living female striped mice (Rhabdomys pumilio). Females are group living...

Data from: Initiating Antiretroviral Therapy for HIV at a Patient’s First Clinic Visit: The RapIT Randomized Controlled Trial

Mhairi Maskew, Sydney Rose, Matthew Fox, Cynthia Nyoni, Constance Mongwenyana, Given Malete, Ian Sanne, Dorah Bokaba, Celeste Sauls, Julia Rohr & Lawrence Long
Background: High rates of patient attrition from care between HIV testing and antiretroviral therapy (ART) initiation have been documented in sub-Saharan Africa, contributing to persistently low CD4 cell counts at treatment initiation. One reason for this is that starting ART in many countries is a lengthy and burdensome process, imposing long waits and multiple clinic visits on patients. We estimated the effect on uptake of ART and viral suppression of an accelerated initiation algorithm that...

Factors associated with COVID-19 infections and mortality in Africa: A cross-sectional study using publicly available data

Kennedy Otwombe
Introduction The current COVID-19 pandemic is a global threat. This elicits questions on the level of preparedness and capacity of health systems to respond to emergencies. Relative to other parts of the world, Africa has poorly developed health systems with limited capacity to respond to health crises. Africa is particularly disadvantaged. Methods This cross-sectional study uses publicly available core health data for 53 African countries, to determine risk factors for cumulative COVID-19 deaths and cases...

Quality of Life Survey I 2009

Data from: The Triassic Mesophlebiidae, a little closer to the crown of the Odonata (Insecta) than other ‘triassolestids’

Ayla Tierney, Isabelle Deregnaucourt, John M. Anderson, Paul Tierney, Torsten Wappler & Olivier Béthoux
Two new, subcomplete forewings belonging to the ‘triassolestid assemblage’, a group of Triassic stem-relatives of dragon- and damselflies (Odonata), are described. One, recovered from Australia (Aranbanga Volcanic Group), belongs to Mesophlebia antinodalis Tillyard, 1916, previously documented on the basis of two very incomplete wings. The other, recovered from South Africa (Molteno Formation), is assigned to a new species, Mesophlebia elegans sp. nov. The new data allow a reconsideration of the diagnosis of the genus Mesophlebia...

Presents-absents of woody species on termite mounds and the savanna matrix in Africa

Justice Muvengwi & Ed Witkowski
Questions: Although the biogeography of plant communities has been well studied, mechanisms controlling plant community diversity are still poorly understood. Stochastic and deterministic processes are hotly debated as being key in structuring communities across taxa. Here we ask, to what extent are plant communities on termite mounds shaped by either stochastic or deterministic processes within and between regions on the African continent? Methods: We performed a meta-analysis on 23 studies that satisfied our selection criteria...

Rethinking megafauna

Marcos Moleón, José Sánchez-Zapata, José Donázar, Eloy Revilla, Berta Martín-López, Cayetano Gutiérrez-Cánovas, Wayne Getz, Zebensui Morales-Reyes, Ahimsa Campos-Arceiz, Larry Crowder, Mauro Galetti, Manuela González-Suárez, Fengzhi He, Pedro Jordano, Rebecca Lewison, Robin Naidoo, Norman Owen-Smith, Nuria Selva, Jens-Christian Svenning, José Tella, Christiane Zarfl, Sonja Jähnig, Matt Hayward, Søren Faurby, Nuria García … & Klement Tochner
Concern for megafauna is increasing among scientists and non-scientists. Many studies have emphasized that megafauna play prominent ecological roles and provide important ecosystem services to humanity. But, what precisely are “megafauna”? Here we critically assess the concept of megafauna and propose a goal-oriented framework for megafaunal research. First, we review definitions of megafauna and analyze associated terminology in the scientific literature. Second, we conduct a survey among ecologists and paleontologists to assess the species traits...

Data from: The role of browsers in maintaining the openness of savanna grazing lawns

Michael Voysey, Michelle Greve, Sally Archibald, William Bond, Carla Staver & Jason Donaldson
1. In savannas, ruminant herbivores can have divergent impacts on tree recruitment and resulting woody cover. Heavy grazing by cattle results in woody thickening, whereas intensive grazing by wildlife instead tends to be associated with lower woody cover. 2. To disentangle why woody cover is low in areas heavily grazed by wildlife, we tested (I) whether short-grass environments attract indigenous mammalian browsers; (II) whether preference for short grass decreases with browser body mass because of...

Fire and grazing determined grasslands of central Madagascar represent ancient assemblages

Cedrique Solofondranohatra, Maria Vorontsova, Gareth Hempson, Jan Hackel, Stuart Cable, Vololoniaina Jeannoda & Caroline Lehmann
The ecology of Madagascar’s grasslands is under-investigated and the dearth of ecological understanding of how disturbance by fire and grazing shapes these grasslands stems from a perception that disturbance shaped Malagasy grasslands only after human arrival. However, worldwide, fire and grazing shape tropical grasslands over ecological and evolutionary timescales, and it is curious Madagascar should be a global anomaly. We examined the functional and community ecology of Madagascar’s grasslands across 71 communities in the Central...

Data from: Implementation of Option B and a fixed-dose combination antiretroviral regimen for prevention of mother-to-child transmission of HIV in South Africa: a model of uptake and adherence to care

Mhairi Maskew, Lise Jamieson, Given Mohomi, Lawrence Long, Constance Mongwenyana, Dorah Bokaba, Matthew P Fox, Ian Sanne & Sydney Rosen
Introduction Initiating and retaining pregnant women on antiretroviral therapy (ART) to prevent mother-to-child HIV transmission (PMTCT) remains a major challenge facing African HIV programs, particularly during the critical final months prior to delivery. In 2013, South Africa implemented its “Option B” PMTCT regimen (three-drug ART throughout pregnancy and breastfeeding, regardless of maternal CD4 count) and introduced once-daily fixed-dose combinations and lifelong ART. Currently, the uptake of Option B and its possible impact on adherence to...

The intensity of sexual selection, body size and reproductive success in a mating system with male-male combat: Is bigger better?

Xavier Glaudas, Stephen Rice, Rulon Clark & Graham Alexander
Body size is a key selected trait in many animal systems: larger size is sexually selected for in males because it confers a reproductive advantage during contest competition for access to females, and larger females are naturally selected for fecundity. Herein, we used radio-telemetry to gather a large dataset of male-female interactions and DNA paternity analyses to characterize the intensity of sexual selection and the link between two body size metrics (body length and condition,...

Groundwater recharge in Africa from ground based measurements

Alan MacDonald, Murray Lark, Richard Taylor, Tamiru Abiye, Helen Fallas, Guillaume Favreau, Ibrahim Goni, Seifu Kebede, Bridget Scanlon, James Sorenson, Moshood Tijani, Kirsty Upton & Charles West
This dataset comprises a map of groundwater recharge for Africa and a database of the 134 observations used to generate the map. The map shows long term average annual groundwater recharge in mm per annum relevant to the period 1970 to 2020. It is in the form of a GIS shapefile and is available as a layer package for ESRI and also as a georeferenced TIFF and BIL file for easy exchange with other software....

Resprouting grasses are associated with less frequent fire than seeders

Kimberley Simpson, Emma Jardine, Sally Archibald, Elizabeth Forrestel, Caroline Lehmann, Gavin Thomas & Colin Osborne
Plant populations persist under recurrent fire via resprouting from surviving tissues (resprouters) or seedling recruitment (seeders). Woody species are inherently slow-maturing, meaning that seeders are confined to infrequent fire regimes. However, for grasses, which mature faster, the relationships between persistence strategy and fire regime remains unknown. Globally, we analysed associations between fire regimes experienced by hundreds of grass species and their persistence strategy, within a phylogenetic context. We also tested whether persistence strategies are associated...

Supplementary data: What drives grassland-forest boundaries? Assessing fire and frost effects on tree seedling survival and architecture

Monique Botha, Sally Archibald & Michelle Greve
Fire and frost represent two major hurdles for the persistence of trees in open grassy biomes and have both been proposed as drivers of grassland-forest boundaries in Africa. We assess the response of young tree seedlings, which represent a vulnerable stage in tree recruitment, to traumatic fire and frost disturbances. In a greenhouse experiment, we investigated how seedling traits predicted survival and resprouting ability in response to fire vs frost; we characterised survival strategies of...

Registration Year

  • 2020
    16

Resource Types

  • Dataset
    16

Affiliations

  • University of the Witwatersrand
    16
  • University of Pretoria
    2
  • San Diego State University
    2
  • Royal Botanic Garden Edinburgh
    2
  • Boston University
    2
  • Estación Biológica de Doñana
    1
  • Bangor University
    1
  • University of Vic
    1
  • Sao Paulo State University
    1
  • Stanford University
    1