682 research outputs found

    How to link people, government, and science in effective large-scale management of invasive trees

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    A common limitation for the effective management of widespread non-native species is translating and implementing the latest scientific knowledge for practitioners. Non-native tree invasions are no exception to this problem. We illustrate how the National Wilding Conifer Control Programme in New Zealand has worked to overcome these limitations through a partnership approach, ensuring affected communities are connected to on-the-ground responses, and facilitating the transfer of new scientific knowledge to practitioners. By ensuring the overarching management strategy was developed collaboratively with clear, mutually-agreed goals, the programme has helped to unite diverse stakeholders with a common purpose. Although coordinated by a central government body, the governance structure is sufficiently flexible to address the specific management needs of each affected community. The programme takes an adaptive management approach that enables multiple lines of research and management to be developed together; this is essential to improve management across different regions and stages of invasion. A co-developed strategy, partnership structure, and adaptive management were each critical components of the National Wilding Conifer Control Programme. However, there are ongoing challenges to overcome, such as securing long-term funding and reducing risks of re-invasion, to meet the ultimate goal of containing conifer invasions nationally. We suggest that lessons from this programme provide general insights into how linking people, government, and science could be used to improve the effectiveness of large-scale invasive non-native species management elsewhere

    Towards management of invasive ectomycorrhizal fungi

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    Ectomycorrhizal fungi are increasingly recognized as invasive species. Invasive ectomycorrhizal fungi can be toxic to humans, may compete with native, edible or otherwise valuable fungi, facilitate the co-invasion of trees, and cause major changes in soil ecosystems, but also have positive effects, enabling plantation forestry and, in some cases, becoming a valuable food source. Land-managers are interested in controlling and removing invasive fungi, but there are few available strategies for management and none are based on robust scientific evidence. Nonetheless, despite the absence of relevant experiments, we suggest that knowledge of the fundamental ecology of fungi can help guide strategies. We review the literature and suggest potential strategies for prevention, for slowing the spread of invasive fungi, for eradication, and for long-term management. In many cases the most appropriate strategy will be species and context (including country) specific. In order to effectively address the problems posed by invasive ectomycorrhizal fungi, land managers and scientists need to work together to develop and robustly test control and management strategies

    Double aluminum recovery and its reuse in wastewater treatment

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    This work evaluates the use of aluminum contained in the aluminum–polyethylene films as anodic electrodes using the electrocoagulation technique to reduce the pollutant contents of industrial wastewater quickly and effectively. Thermal treatment at 500 °C produces pure aluminum (according to TGA and SEM/EDS analysis) which is used to construct aluminum disks (applying 6 tons/cm2 of pressure). Aluminum disks are used as cathodes and anodes in an electrochemical cell. The current density applied in the recovered Al electrodes was 12 mA cm−2, and the maximum COD reduction of wastewater was 77 % at 25 min of treatment. The color and turbidity reductions are 87 and 90 %, respectively. The resulting sludge of wastewater treatment was thermally treated and a second aluminum recovery was reached; since the organic material present in the sludge was removed by the high temperature, the obtained aluminum was pure enough for its reuse. The use of aluminum–polyethylene films as electrodes in the electrocoagulation process contributes to the pollutant removal without the addition of chemical reagents or changing the pH, so it is both effective and environmentally friendly.UAEM-UNAM CONACY

    Gamma radiation as a recycling tool for waste materials used in concrete

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    Over the course of the last 50 years, a large number of major technological advances have contributed to the development of higher-strength, high-performance materials that provide excellent benefits. Nevertheless, in most cases, after a very short useful life, these products become waste material and contribute to environmental degra‐ dation. This situation has created an environmental crisis that has reached global proportions. In efforts to combat this issue and to promote sustainable development and reduce environmental pollution, some investigations have focused on recycling using innovative and clean technologies, such as gamma radiation, as an alternative to conventional mechanical and chemical recycling procedures. In this context, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete; for example, the compressive strength and modulus of elasticity are improved by the addition of waste particles and application of gamma radiation. In this chapter, we propose the use of gamma radiation as a method for modifying waste materials; for instance, polyethylene terephthalate plastic bottles, automotive tire rubber, and the cellulose in Tetra Pak containers, and their reuse to enhance the properties of concrete

    The karyotype of Nothoscordum arenarium Herter (Gilliesioideae, Alliaceae): A populational and cytomolecular analysis

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    The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA+ /DAPI - heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA + regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that, despite isolated cases of polyploidy and translocation, the karyotype of N. arenarium is very stable and the karyotypic instability described for other species may be associated with their polyploid condition

    Cytological analysis of hybrids among triticales and trigopiros

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    We studied three different tricepiros: (Don Santiago x Don Noé), (Cumé x Horovitz) and (Cumé x Don Noé). The tricepiro (Don Santiago x Don Noé) was obtained by crossing the triticale Don Santiago INTA (AABBRR, 2n = 6x = 42) with the trigopiro Don Noé INTA (AABBDDJJ, 2n = 8x = 56). The number of chromosomes for the F1 was 2n = 49, the most frequent meiotic configuration being 14 bivalents and 21 univalents. The univalents were situated in the periphery of the equatorial plane, whereas the bivalents were located in the central zone. The chromatids in some of the univalents split when bivalents underwent reductional division in anaphase I. There were few laggard chromosomes or chromatids at this phase. The number of chromosomes (2n = 48-58) was high and variable, and the number of bivalents per cell (18-23) also high in F 3 individuals. In all F 8 tricepiros (Don Santiago x Don Noé), F 12 tricepiros (Cumé x Horovitz) and F 12 tricepiros (Cumé x Don Noé), the number of chromosomes (2n = 42) was the same, these retaining the rye genome, as demonstrated by GISH and FISH. These new synthesized allopolyploids constitute interesting models for investigating the evolutionary changes responsible for diploidization, and the chromosomal and genomic re-ordering that cannot be revealed in natural allopolyploids

    “Rambo root” to the rescue: How a simple, low‐cost solution can lead to multiple sustainable development gains

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    Rugged and resilient, cassava is a bulky root crop that can thrive on poor soils. Cultivating it offers the potential to restore degraded land, which in turn may reduce hunger, generate livelihoods, fight climate change and even promote peace. As such, farming cassava offers a nature‐based solution that can contribute to achieving numerous sustainable development targets. The authors acknowledge that scaling up production of any commodity may bring risks of deforestation and biodiversity loss through clearing forest areas. In the case of increasing cassava production, though, this may not be the case because cassava can be cultivated on land affected by degradation, and this resource is abundant; policies and initiatives exist to mitigate those risks; and the principal goal is to scale up a sustainable land use system

    Applying multi-phase DES approach for modelling the patient journey through accident and emergency departments

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    Accident and Emergency departments (A&ED) are in charge of providing access to patients requiring urgent acute care. A&ED are difficult to model due to the presence of interactions, different pathways and the multiple outcomes that patients may undertake depending on their health status. In addition, public concern has focused on the presence of overcrowding, long waiting times, patient dissatisfaction and cost overruns associated with A&ED. There is then a need for tackling these problems through developing integrated and explicit models supporting healthcare planning. However, the studies directly concentrating on modelling the A&EDs are largely limited. Therefore, this paper presents the use of a multi-phase DES framework for modelling the A&ED and facilitating the assessment of potential improvement strategies. Initially, the main components, critical variables and different states of the A&ED are identified to correctly model the entire patient journey. In this step, it is also necessary to characterize the demand in order to categorize the patients into pipelines. After this, a discrete-event simulation (DES) model is developed. Then, validation is conducted through the 2-sample t test to demonstrate whether the model is statistically comparable with the real-world A&ED department. This is followed by the use of Markov phase-type models for calculating the total costs of the whole system. Finally, various scenarios are explored to assess their potential impact on multiple outcomes of interest. A case study of a mixed-patient environment in a private A&E department is provided to validate the effectiveness of the multi-phase DES approach

    Prioritising surveillance for alien organisms transported as stowaways on ships travelling to South Africa

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    The global shipping network facilitates the transportation and introduction of marine and terrestrial organisms to regions where they are not native, and some of these organisms become invasive. South Africa was used as a case study to evaluate the potential for shipping to contribute to the introduction and establishment of marine and terrestrial alien species (i.e. establishment debt) and to assess how this varies across shipping routes and seasons. As a proxy for the number of species introduced (i.e. 'colonisation pressure') shipping movement data were used to determine, for each season, the number of ships that visited South African ports from foreign ports and the number of days travelled between ports. Seasonal marine and terrestrial environmental similarity between South African and foreign ports was then used to estimate the likelihood that introduced species would establish. These data were used to determine the seasonal relative contribution of shipping routes to South Africa's marine and terrestrial establishment debt. Additionally, distribution data were used to identify marine and terrestrial species that are known to be invasive elsewhere and which might be introduced to each South African port through shipping routes that have a high relative contribution to establishment debt. Shipping routes from Asian ports, especially Singapore, have a particularly high relative contribution to South Africa's establishment debt, while among South African ports, Durban has the highest risk of being invaded. There was seasonal variation in the shipping routes that have a high relative contribution to the establishment debt of the South African ports. The presented method provides a simple way to prioritise surveillance effort and our results indicate that, for South Africa, port-specific prevention strategies should be developed, a large portion of the available resources should be allocated to Durban, and seasonal variations and their consequences for prevention strategies should be explored further. (Résumé d'auteur
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