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

Effect of Kiwifruit Vine Decline Inducing Soils on Growth, Mineral uptake, and Protein Content in Different Actinidia Genotypes Radical Systems

The Kiwifruit Vine Decline Syndrome (KVDS) is a sever disease, which is causing dramatics yield losses and economic damage. Primary identified in Veneto region, nowadays, it is present worldwide. Concerning symptoms, in the radical system is possible to note a widespread root rot and absence of feeding roots. Furthermore, a wilting of leaves appears, which, as consequence, shortly brings to a total collapse of the whole plant. The disease is caused by both biotic and abiotic factors, enhanced primary by soil borne pathogens and waterlogging conditions. Up to date, there is not any effective managing strategy, and the disease is still being studied. Nevertheless, the availability of a large Actinidia germplasm collection open up to the possibility of screening different species in order to find traits to contrast KVDS. In this context, we selected 4 species of Actinidia (A. macrosperma, A. deliciosa, A. arguta and ‘Sav1’ cultivar), planted in KVDS inducing soils, and evaluated the radical system after one vegetative season. Abiotic and biotic stresses induce numerous biochemical and physiological responses in plants, commonly identified as a different capability of mineral up taking and protein degradation, as well as growing differentiation. For these instances, the different genotypes attitude to grow in KVDS inducing soils was evaluated. Hence, the growth of the radical system was determined, taking into account a measure such as the volume. Indeed, the concentration of mineral elements was measured by using the Inductively Coupled Plasma-Atomic Emission Spectrometry, while the total protein content was measured through the Bradford assay. Yet, discontinuous sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed in order to separate proteins and then determining their patterns. The results showed that there exist significant differences regarding the growing capability in KVDS inducing soils among the tested genotypes. Interestingly, there were a different content in terms of mineral elements in roots, as well as the protein content. Surprisingly, no differences were found on protein’s patterns. These first evidence demonstrated how different Actinidia species were able to grow in these soils, showing a different capability of nutrient uptake and protein content. Thus, compared to that already known as sensitive (e.g., Actinidia deliciosa cv. Hayward), the tolerant genotypes had a better performance of the radical system

Comparison between Glaser Method and Heat, Air and Moisture Transient Model for Moisture Migration in Building Envelopes

The Glaser method is an assessment procedure for the risk of moisture accumulation in building mono-dimensional structures, that could be used to evaluate mould risk and interstitial con- densation risk. It is based on a simplified model that does not represent the real phenomenon and its limitations are well-known qualitatively. This work provides a comparison in terms of moisture con- tent between the Glaser method and WUFI Pro, an advanced heat, air and moisture transfer prediction tool. First the influence of material properties is evaluated on four fictitious materials walls, then six different building envelope typologies for six weather files from Central and Southern Europe are modelled to evaluate the Glaser method results. The effects of the Glaser method simplifications are quantified in terms of moisture content percentage difference

Building Refurbishment for Energy Performance

Discusses ways to save energy in building refurbishment Gives suggestions to improve energy efficiency Includes case studies and results In Europe, the building sector accounts for 40% of energy consumption which has a strong influence on greenhouse gas emissions. The book deals with efficient methodologies aimed to reduce greenhouse gas emissions in the building sector. This includes analyses of the building envelopes, the heating systems, the use of solar energy, and the assessment of the environmental and energy sustainability of the proposed solutions. After a brief introduction to the physical fundamentals involved in the study, results are presented to support cost-effective technical strategies to promote actions for energy saving, in the most critical fields and with the most economic advantage. Content Level » Researc