52 research outputs found

    Science engagement in South Africa

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    Learners from grades 9 to 12 surrounded our Science Week table in the township Khaye-litsha, an impoverished community near Cape Town in South Africa. We were conducting outreach for our project Cape Citizen Science (http://citsci.co.za/), an initiative to engage nonscientists in plant disease research in a global biodiversity hotspot.http://www.sciencemag.orghj2018Forestry and Agricultural Biotechnology Institute (FABI

    Urban environments provide opportunities for early detections of Phytophthora invasions

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    Globalization has increased the frequency of inadvertent introductions of plant pathogens. Many catastrophic invasions of both natural and agricultural systems have been initiated through anthropogenic dissemination pathways. Phytophthora species are a group of invasive plant pathogens causing many of the most important plant disease epidemics. A review of Phytophthora species descriptions published following the publication of the first DNA-based Phytophthora phylogeny was conducted to highlight patterns of recent introductions and to provide insights for early pathogen detection initiatives. Seventy-two publications from 2001 to 2016 describing 98 Phytophthora species were evaluated. Of the 91 species with data on geographic location isolation, 22% were described from type specimens isolated from urban environments, 33% from agricultural environments and 45% from natural environments. Within the urban environment, ornamental plant trading nurseries were the most important sources. Specifically, for Phytophthora ramorum, a species causing multiple epidemics globally, the largest proportion of first report publications were from urban environments, including nurseries. We therefore suggest that detection programs for invasive plant pathogens within the urban environment would be valuable. In this regard, specialized monitoring and citizen science projects that target urban areas where live plant-trading industries are concentrated would be particularly effective to both promote early detection and to facilitate a rapid response to new species invasions

    Two novel Phytophthora species from the southern tip of Africa

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    The microbial diversity associated with natural vegetation in the Greater Cape Floristic Region of South Africa is largely unexplored. As part of the Cape Citizen Science programme and independent research, surveys were conducted between 2015 and 2019 to catalogue the diversity of Phytophthora species associated with many plant species endemic to this region. Using soil and water baiting techniques, six isolates of the provisionally described Phytophthora taxon emzansi were recovered, together with three isolates of an undescribed Phytophthora species. In this study, we used both molecular and morphological data to describe these Phytophthora species. Isolates of P. emzansi sp. nov. and P. afrocarpa sp. nov. formed monophyletic lineages within Phytophthora Clades 2 and 10, respectively. Phytophthora emzansi sp. nov. and P. capensis are sister species residing in the P. citricola species complex, and both are homothallic. Phytophthora afrocarpa sp. nov. is a sister species to P. gallica, and both these taxa are sexually sterile. The present study augments our knowledge of the unique Phytophthora species associated with the native vegetation of southern Africa.Crowd-funding initiative of Joseph M. Hulbert, the University of Pretoria, members of the Tree Protection Cooperative Programme (TPCP), DSI/NRF Centre of Excellence in Plant Health Biotechnology (CPHB) South Africa and the Department of Forestry, Fisheries and the Environment (DFFE), South Africa.http://link.springer.com/journal/11557hj2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc

    Citizen science in environmental and ecological sciences

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    Citizen science is an increasingly acknowledged approach applied in many scientific domains, and particularly within the environmental and ecological sciences, in which non-professional participants contribute to data collection to advance scientific research. We present contributory citizen science as a valuable method to scientists and practitioners within the environmental and ecological sciences, focusing on the full life cycle of citizen science practice, from design to implementation, evaluation and data management. We highlight key issues in citizen science and how to address them, such as participant engagement and retention, data quality assurance and bias correction, as well as ethical considerations regarding data sharing. We also provide a range of examples to illustrate the diversity of applications, from biodiversity research and land cover assessment to forest health monitoring and marine pollution. The aspects of reproducibility and data sharing are considered, placing citizen science within an encompassing open science perspective. Finally, we discuss its limitations and challenges and present an outlook for the application of citizen science in multiple science domains

    Recent Progress in the Computational Many-Body Theory of Metal Surfaces

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    In this article we describe recent progress in the computational many-body theory of metal surfaces, and focus on current techniques beyond the local-density approximation of density-functional theory. We overview various applications to ground and excited states. We discuss the exchange-correlation hole, the surface energy, and the work function of jellium surfaces, as obtained within the random-phase approximation, a time-dependent density-functional approach, and quantum Monte Carlo methods. We also present a survey of recent quasiparticle calculations of unoccupied states at both jellium and real surfaces.Comment: 17 pages, 1 figure, to appear in Comput. Phys. Commu

    Theory of inelastic lifetimes of low-energy electrons in metals

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    Electron dynamics in the bulk and at the surface of solid materials are well known to play a key role in a variety of physical and chemical phenomena. In this article we describe the main aspects of the interaction of low-energy electrons with solids, and report extensive calculations of inelastic lifetimes of both low-energy electrons in bulk materials and image-potential states at metal surfaces. New calculations of inelastic lifetimes in a homogeneous electron gas are presented, by using various well-known representations of the electronic response of the medium. Band-structure calculations, which have been recently carried out by the authors and collaborators, are reviewed, and future work is addressed.Comment: 28 pages, 18 figures, to appear in Chem. Phy

    The problem with delineating narrow criteria for citizen science

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    No abstract available.http://www.pnas.org2020-01-30hj2019Forestry and Agricultural Biotechnology Institute (FABI

    The role of citizen science in addressing grand challenges in food and agriculture research

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    The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term ‘citizen science’ has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science.This working group was partially funded from the NCSU Plant Sciences Initiative, College of Agriculture and Life Sciences ‘Big Ideas’ grant, National Science Foundation grant to R.R.D. (NSF no. 1319293), and a United States Department of Food and Agriculture-National Institute of Food and Agriculture grant to S.F.R., USDA-NIFA Post Doctoral Fellowships grant no. 2017-67012-26999.http://rspb.royalsocietypublishing.orghj2018Forestry and Agricultural Biotechnology Institute (FABI

    Botanical gardens provide valuable baseline Phytophthora diversity data

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    Phytophthora species are important plant pathogens especially due to their ability to invade and change ecosystems. However, information regarding their diversity and distribution is not available in many parts of the world. In these areas, surveys of botanical gardens can provide opportunities to detect novel plant-microbe interactions on both indigenous and exotic plants. Three botanical gardens and one historical urban garden in the Western Cape Province of South Africa were surveyed to establish baseline information of Phytophthora species diversity in the Cape Floristic Region. Eight described species (P. amnicola, P. asparagi, P. capensis, P. cinnamomi, P. chlamydospora, P. lacustris, P. multivora and P. tropicalis), the known but as yet unnamed P. sp. emzansi and 3 putative hybrids were recovered. Forty eight of 103 samples collected were positive for Phytophthora species and P multivora was the most frequently isolated species. Three species (P. amnicola, P. asparagi and P. tropicalis) had not previously been reported in South Africa, although hybrid progeny of P. amincola had been found in two previous studies. These results highlight the value of botanical gardens as areas for baseline data collection and early warning systems
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