7 research outputs found
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Participatory evaluation of groundnut planting methods for pre-harvest aflatoxin management in Eastern Province of Zambia
Aflatoxin contamination remains a major challenge for smallholder groundnut producers in Southern Africa. This is compounded by the stringent aflatoxin regulatory regimes in the lucrative international markets that continue to deny groundnuts produced in this region the access to markets. Participatory on-farm experiments were carried in 2016 and 2017 in Chinkhombe (Katete) and Kalichero (Chipata), and on-station trials at Mount Makulu Central Research Station (Chilanga) to evaluate the efficacy of groundnut planting methods: planting in double rows, single rows, tied ridges and on flatbeds, for pre-harvest aflatoxin management. Planting on flatbeds (no ridges), a popular planting method in most parts of Zambia was designated as the baseline. Significantly low (p < 0.05) levels of aflatoxin, (10.3 ± 3.1 mg/kg) were recorded in the groundnuts planted on tied ridges, and less than 22% of these had aflatoxin levels above the Zambia regulatory limit of 10 mg/kg, compared to more than 40% in other methods. Except for double rows, significantly higher pod yield, 1193 kg/ha, was recorded in groundnuts planted on tied ridges compared to other pre-harvest management options. A reduction of 37 and 81% in aflatoxin contamination was observed in groundnuts planted on single rows and tied ridges, respectively compared to an increase of 39.2% in double rows above 54.3 ± 10.9 mg/kg recorded in flatbeds. In addition, tied ridging was observed to improve plant vigour, lower disease incidence, insect pest and weed infestation. It is clear that the evaluation of these practices on-farm enabled more farmers to be more aware of the effects of these methods and get motivated to adopt them. It is thus imperative that participatory on-farm evaluations of existing aflatoxin management options are carried out as they are an essential step in influencing adoption and uptake of preharvest management control methods among smallholder farmers
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Southern African Agriculture and Climate Change: Zimbabwe. Summary note
This summary note is an excerpt from the chapter on Zimbabwe that will appear in the peer-reviewed IFPRI monograph, Southern African Agriculture and Climate Change: A Comprehensive Analysis
Informing the process of agricultural market reform in Mozambique: a progress report
A progress report on the design of a pilot agricultural market information system in Mozambique.The purpose of this paper is to present the progress, to date, in the design of a pilot agricultural market information system (AMIS) in Mozambique. The authors recently conducted a three week rapid appraisal in the country. The team interviewed GOM and donor officials in Maputo, visited two provincial capitals, four district capitals and selected rural areas surrounding these district capitals. In each location, the team interviewed local officials, lojistas, wholesalers, and farmers. The information obtained shed a great deal of light on the structure of the Mozambican food system, on local perceptions of pricing and market regulation policies and on the problems facing traders and farmers in responding positively to the improved policy and security environment in the country. This paper reports selected findings of this field work and discusses their implications for the AMIS design.USAID (Southern African Research Programme
Sourcing high tissue quality brains from deceased wild primates with known socioâecology
The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviours such as language and sophisticated tool use. To understand this evolution, a diverse sample set of humans' closest relatives with varying socio-ecologies is needed. However, current brain banks predominantly curate brains from primates that died in zoological gardens. We try to address this gap by establishing a field pipeline mitigating the challenges associated with brain extractions of wild primates in their natural habitat. The success of our approach is demonstrated by our ability to acquire a novel brain sample of deceased primates with highly variable socio-ecological exposure and a particular focus on wild chimpanzees. Methods in acquiring brain tissue from wild settings are comprehensively explained, highlighting the feasibility of conducting brain extraction procedures under strict biosafety measures by trained veterinarians in field sites. Brains are assessed at a fine-structural level via high-resolution MRI and state-of-the-art histology. Analyses confirm that excellent tissue quality of primate brains sourced in the field can be achieved with a comparable tissue quality of brains acquired from zoo-living primates. Our field methods are noninvasive, here defined as not harming living animals, and may be applied to other mammal systems than primates. In sum, the field protocol and methodological pipeline validated here pose a major advance for assessing the influence of socio-ecology on medium to large mammal brains, at both macro- and microstructural levels as well as aiding with the functional annotation of brain regions and neuronal pathways via specific behaviour assessments