15 research outputs found

    Identification of pre-leukaemic haematopoietic stem cells in acute leukaemia.

    Get PDF
    In acute myeloid leukaemia (AML), the cell of origin, nature and biological consequences of initiating lesions, and order of subsequent mutations remain poorly understood, as AML is typically diagnosed without observation of a pre-leukaemic phase. Here, highly purified haematopoietic stem cells (HSCs), progenitor and mature cell fractions from the blood of AML patients were found to contain recurrent DNMT3A mutations (DNMT3A(mut)) at high allele frequency, but without coincident NPM1 mutations (NPM1c) present in AML blasts. DNMT3A(mut)-bearing HSCs showed a multilineage repopulation advantage over non-mutated HSCs in xenografts, establishing their identity as pre-leukaemic HSCs. Pre-leukaemic HSCs were found in remission samples, indicating that they survive chemotherapy. Therefore DNMT3A(mut) arises early in AML evolution, probably in HSCs, leading to a clonally expanded pool of pre-leukaemic HSCs from which AML evolves. Our findings provide a paradigm for the detection and treatment of pre-leukaemic clones before the acquisition of additional genetic lesions engenders greater therapeutic resistance

    Birds and bioenergy within the americas: A cross‐national, social–ecological study of ecosystem service tradeoffs

    Get PDF
    Although renewable energy holds great promise in mitigating climate change, there are socioeconomic and ecological tradeoffs related to each form of renewable energy. Forest‐related bioenergy is especially controversial, because tree plantations often replace land that could be used to grow food crops and can have negative impacts on biodiversity. In this study, we examined public perceptions and ecosystem service tradeoffs between the provisioning services associated with cover types associated with bioenergy crop (feedstock) production and forest habitat‐related supporting services for birds, which themselves provide cultural and regulating services. We combined a social survey‐based assessment of local values and perceptions with measures of bioenergy feedstock production impacts on bird habitat in four countries: Argentina, Brazil, Mexico, and the USA. Respondents in all countries rated birds as important or very important (83–99% of respondents) and showed lower enthusiasm for, but still supported, the expansion of bioenergy feedstocks (48–60% of respondents). Bioenergy feedstock cover types in Brazil and Argentina had the greatest negative impact on birds but had a positive impact on birds in the USA. In Brazil and Mexico, public perceptions aligned fairly well with the realities of the impacts of potential bioenergy feedstocks on bird communities. However, in Argentina and the USA, perceptions of bioenergy impacts on birds did not match well with the data. Understanding people’s values and perceptions can help inform better policy and management decisions regarding land use changes

    Apophis planetary defense campaign

    Get PDF
    We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA's Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk

    Avaliação e acompanhamento audiológico após meningite bacteriana Audiological assessment and follow-up post bacterial meningitis

    No full text
    A deficiĂȘncia auditiva Ă© uma das sequelas da meningite bacteriana que ocorre com maior frequĂȘncia em crianças. Este estudo descreve o perfil audiolĂłgico (perifĂ©rico e central) de crianças internadas com diagnĂłstico de meningite bacteriana. Nas 89 crianças que compareceram ao seguimento audiolĂłgico apĂłs a alta hospitalar e foram submetidas aos testes audiolĂłgicos, os resultados evidenciaram que 85,4% apresentaram acuidade auditiva normal em ambas orelhas, 10,1% apresentaram deficiĂȘncia auditiva neurossensorial bilateral e 4,5% apresentaram deficiĂȘncia auditiva neurossensorial unilateral. Nos testes que avaliaram as habilidades de processamento auditivo, os resultados mostraram que 10% dessas crianças apresentaram alteração no desempenho de localização auditiva e de reconhecimento de sentenças com mensagem competitiva ipsilateral.Hearing loss is the more frequent sequel of bacterial meningitis in children. This study describes the audiological profile (peripheric and central) of 89 children admitted to the hospital wards with the diagnosis of bacterial meningitis. Those children attended audiological follow up, after their hospital descharge, and were submitted to audiological tests. The results showed that 85.4% among them presented normal hearing in both ears 10.1% presented bilateral neurosensorial hearing loss and 4.5% presented unilateral neurosensorial hearing loss. The results from the auditory processing skills assessment showed that 10% of those children presented auditory localization and recognition of sentences with competitive messages (Paediatric Sentences Identification - ipsilateral) disorders

    Chapter 10: Lessons from the transdisciplinary, international BIOPIRE project

    No full text
    A transdisciplinary group of scientists and industrial, governmental and non-governmental organization partners collaborated to study the sustainability of bioenergy development across the Americas. The research focused on understanding the socioecological impacts of bioenergy in Argentina, Brazil, Canada, Mexico, Uruguay and the US. This chapter reports on how the group was formed through a smaller group that recognized the value of an interdisciplinary approach to studying environmental problems. We discuss the barriers and strategies the team faced when conducting transdisciplinary research and how environmental researchers and scientists can use this knowledge to anticipate challenges associated with transdisciplinary, international research. Lastly, we demonstrate the importance of recognizing environmental management issues as socioecological problems and show that studying them requires transdisciplinary teamwork

    Birds and Bioenergy within the Americas: A Cross-National, Social–Ecological Study of Ecosystem Service Tradeoffs

    No full text
    Although renewable energy holds great promise in mitigating climate change, there are socioeconomic and ecological tradeoffs related to each form of renewable energy. Forest-related bioenergy is especially controversial, because tree plantations often replace land that could be used to grow food crops and can have negative impacts on biodiversity. In this study, we examined public perceptions and ecosystem service tradeoffs between the provisioning services associated with cover types associated with bioenergy crop (feedstock) production and forest habitat-related supporting services for birds, which themselves provide cultural and regulating services. We combined a social survey-based assessment of local values and perceptions with measures of bioenergy feedstock production impacts on bird habitat in four countries: Argentina, Brazil, Mexico, and the USA. Respondents in all countries rated birds as important or very important (83–99% of respondents) and showed lower enthusiasm for, but still supported, the expansion of bioenergy feedstocks (48–60% of respondents). Bioenergy feedstock cover types in Brazil and Argentina had the greatest negative impact on birds but had a positive impact on birds in the USA. In Brazil and Mexico, public perceptions aligned fairly well with the realities of the impacts of potential bioenergy feedstocks on bird communities. However, in Argentina and the USA, perceptions of bioenergy impacts on birds did not match well with the data. Understanding people’s values and perceptions can help inform better policy and management decisions regarding land use changes
    corecore