48 research outputs found

    Balancing environmental conservation and socioeconomic needs: the complexities of artisanal and small-scale coal mining in Africa

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    Artisanal and small-scale coal mining (ASM) in Africa presents a complex challenge where environmental conservation and socioeconomic development must be carefully balanced. This article explores the intricate dynamics surrounding ASM in the African context, highlighting the multifaceted impacts on the environment and the socioeconomic well-being of local communities. Artisanal and small-scale coal mining is often characterized by low capital investment, limited mechanization, and dependence on manual labor. Despite this, miners face numerous problems due to the unstable socioeconomic situation and weak labor legislation. The article describes the practice of ASM in Africa: provides an overview of the growing significance of ASM in Africa, and sets the stage for understanding the intricate trade-offs faced in managing this sector. The development of ASM in Africa is examined, considering its historical context, drivers, and patterns of growth, emphasizing the need for context-specific approaches to address its complexities. The article delves into the environmental challenges posed by ASM, focusing on deforestation, land degradation, water and air pollution, and the loss of biodiversity. It examines the specific manifestations of these challenges in selected African countries, shedding light on the varied ecological consequences and their ramifications for sustainable development. Additionally, the socioeconomic dimensions of ASM are explored, acknowledging its potential as a livelihood source for many communities while also recognizing the social and economic vulnerabilities associated with it. The article discusses the interplay between ASM and local economies, including job creation, income generation, and the broader implications for poverty alleviation and sustainable development

    Mitochondrial dysfunction at atherosclerosis and myocardial infarction: molecular and cytochemical cell-markers

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    We studied capabilities of confocal laser scanning microscopy in the analysis of lipid droplets volume and of quantity of functional mitochondria and reactive oxygen species production in liver cells for early diagnosis of cytochemical disturbances at dyslipoproteinemia (16 days of experiment). The results showed the increase of lipid droplets volume in hepatocytes, decrease of functional mitochondria and increase of reactive oxygen species production. We evaluated the potential of real-time PCR method in the analysis of mitochondrial DNA of blood plasma at early stages of dyslipoproteinemia and in experimental infarction. On the background of registered blood lipid metabolism disorders and structural and functional changes in liver cells, we determined the tendency to three-time increase in concentration of circulating cell-free mtDNA on the 16th day of dyslipoproteinemia as compared to the control data. We used a model of myocardial infarction to show statistically significant increase in the level of circulating cell-free blood mtDNA from 48 hours after adrenaline injection and we found that this level maintained up to 144 hours after adrenaline injection. Obtained data can serve as a basis for creation of technologies for diagnostic monitoring of atherosclerosis and myocardial infarction severity

    Acute myocardial ischemia: changes of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery

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    The aim of the present study is to analyze the dynamics of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery. We showed that the concentration of free circulating mtDNA of blood tends to decrease 24 hours after ligation; it increased and reached values close to control samples 48 and 72 hours after ligation. These data define the need in further investigation of the dynamics of this parameter during later periods of myocardial infarction modeling that will contribute to objective evaluation of its significance for acute myocardial damage diagnostics and prognosis

    A novel dynamic multicellular co-culture system for studying individual blood-brain barrier cell types in brain diseases and cytotoxicity testing

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    Blood brain barrier (BBB) cells play key roles in the physiology and pathology of the central nervous system (CNS). BBB dysfunction is implicated in many neurodegenerative diseases, including Alzheimer’s disease (AD). The BBB consists of capillary endothelial cells, pericytes encircling the endothelium and surrounding astrocytes extending their processes towards it. Although there have been many attempts to develop in vitro BBB models, the complex interaction between these celltypes makes it extremely difficult to determine their individual contribution to neurotoxicity in vivo. Thus, we developed and optimised an in vitro multicellular co-culture model within the Kirkstall Quasi Vivo System. The main aim was to determine the optimal environment to culture human brain primary endothelial cells, pericytes and astrocytes whilst maintaining cellular communication without formation of a barrier in order to assess the contribution of each cell type to the overall response. As a proof of concept for the present system, the effects of amyloid-beta 25-35 peptide (Aβ25-35), a hall mark of AD, were explored. This multicellular system will be a valuable tool for future studies on the specific roles of individual BBB cell type (while making connection with each other through medium) in CNS disorders as well as in cytotoxicity tests

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    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
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