30 research outputs found

    Identification of a novel variant of LMP-1 of EBV in patients with endemic Burkitt lymphoma in western Kenya

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    BACKGROUND: Epstein Barr virus (EBV) is a gammaherpesvirus that is associated with nasopharyngeal carcinoma (NPC) and endemic Burkitt lymphoma (eBL). EBV carries several latent genes that contribute to oncogenesis including the latent membrane protein 1 (LMP-1), a known oncogene and constitutively active CD40 homolog. Variation in the C terminal region of LMP-1 has been linked to NPC pathogenesis, but little is known regarding LMP-1 variation and eBL. RESULTS: In the present study, peripheral blood samples were obtained from 38 eBL patients and 22 healthy controls in western Kenya, where the disease is endemic. The LMP-1 C-terminal region from these samples was sequenced and analyzed. The frequency of a 30 base pair deletion of LMP-1 previously linked to NPC was not associated with eBL compared to healthy controls. However a novel LMP-1 variant was identified, called K for Kenya and for the G318K mutation that characterizes it. The K variant LMP-1 was found in 40.5% of eBL sequences and 25.0% of healthy controls. All K variant sequences contained mutations in both of the previously described minimal T cell epitopes in the C terminal end of LMP-1. These mutations occurred in the anchor residue at the C-terminal binding groove of both epitopes, a pocket necessary for MHC loading. CONCLUSIONS: Overall, our results suggest that there is a novel K variant of LMP-1 in Kenya that may be associated with eBL. Further studies are necessary to determine the functional implications of the LMP-1 variant on early events in eBL genesis

    Business experience of floods and drought-related water and electricity supply disruption in three cities in sub-Saharan Africa during the 2015/2016 El Niño

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    Non-technical summary The El Niño event in 2015/2016 was one of the strongest since at least 1950. Through surveys and interviews with key informants, we find businesses in the capital cities of Zambia, Botswana and Kenya experienced major disruption to their activities from El Niño related hydroelectric load shedding, water supply disruption and flooding, respectively. Yet, during the 2015/2016 El Niño, fluctuations in precipitation were not extreme considering the strength of the El Niño event. Results therefore highlight that even fairly moderate precipitation anomalies can contribute to major disruption to economic activity. Addressing the risk of disruption – and supporting the private sector to adapt – is a development priority. Technical summary Drought during the 2015/2016 El Niño amplified disruption to public water supply in Botswana’s capital Gaborone and contributed to unprecedented hydroelectric load shedding across Zambia. In Kenya, moderate precipitation during the El Niño brought localized floods to Nairobi and other areas. Contributing to a sparse literature on firm-level adaptation among micro, small and medium enterprise (MSMEs) in sub-Saharan Africa, through a near-real time assessment we consider MSME experience of this disruption in sectors making substantial contributions to livelihoods and national GDP. Alongside complex and indirect impact pathways that influence total loss and damage, results show varying vulnerability to disruption. Nevertheless, directly after the El Niño event, MSMEs reported water supply disruption, power outages and flooding to be the leading challenge within the business environment in Botswana, Zambia and Kenya respectively. Deeper understanding of vulnerabilities in existing water, energy and urban infrastructure – in the context of increasing urbanisation and a potentially broader range of climate variability – is urgently needed across SSA. This needs to be coupled with public provision of wider enabling conditions – including access to finance – that support private sector adaptation to extreme climate events and associated resource disruption. This paper also identifies clear opportunities to improve climate information services for MSMEs. Social media summary Flooding and water and electricity supply disruption during the 2015/2016 El Niño disrupted business activity in sub-Saharan Africa

    The Anthropocene is functionally and stratigraphically distinct from the Holocene

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    Human activity is leaving a pervasive and persistent signature on Earth. Vigorous debate continues about whether this warrants recognition as a new geologic time unit known as the Anthropocene. We review anthropogenic markers of functional changes in the Earth system through the stratigraphic record. The appearance of manufactured materials in sediments − including aluminum, plastics and concrete − coincides with global spikes in fallout radionuclides and particulates from fossil-fuel combustion. Carbon, nitrogen, and phosphorus cycles have been substantially modified over the last century. Rates of sea-level rise, and the extent of human perturbation of the climate system, exceed Late Holocene changes. Biotic changes include species invasions worldwide and accelerating rates of extinction. These combined signals render the Anthropocene stratigraphically distinct from the Holocene and earlier epochs

    Scale and diversity of the physical technosphere: a geological perspective

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    We assess the scale and extent of the physical technosphere, defined here as the summed material output of the contemporary human enterprise. It includes active urban, agricultural and marine components, used to sustain energy and material flow for current human life, and a growing residue layer, currently only in small part recycled back into the active component. Preliminary estimates suggest a technosphere mass of approximately 30 trillion tonnes (Tt), which helps support a human biomass that, despite recent growth, is ~5 orders of magnitude smaller. The physical technosphere includes a large, rapidly growing diversity of complex objects that are potential trace fossils or ‘technofossils’. If assessed on palaeontological criteria, technofossil diversity already exceeds known estimates of biological diversity as measured by richness, far exceeds recognized fossil diversity, and may exceed total biological diversity through Earth’s history. The rapid transformation of much of Earth’s surface mass into the technosphere and its myriad components underscores the novelty of the current planetary transformation

    Life on land

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