764 research outputs found

    Experimental methods to support the risk assessment of invertebrate biological control agents

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    Moisture source and diet affect development and reproduction of Orius thripoborus and Orius naivashae, two predatory anthocorids from southern Africa

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    The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed

    Opstellen Gezondheidsprofiel van de Bloemekenswijk

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    How ecosystem services are changing: an accounting application at the EU level

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    Ecosystem services accounts are a useful tool that provides relevant information on the role of ecosystems in delivering services, and the society benefiting from them. This paper presents the accounting workflow for ecosystem services at the European Union level adopted by the Knowledge Innovation Project on an Integrated system for Natural Capital and ecosystem services Accounting (KIP INCA) - a European Commission initiative. The workflow includes: 1) biophysical assessment of ecosystem services; 2) monetary valuation; and 3) compilation of accounting tables. Supply and use tables are presented for six ecosystem services assessed so far. The supply table shows woodland and forest, followed by wetlands, as the ecosystem types with the highest monetary value per unit area. Analyses of changes between 2000 and 2012 show an overall increase of the monetary value of ecosystem services, mainly due to an increase in demand for them. We also discuss advantages and disadvantages of adopting a fast-track approach, based on official statistics, in comparison to an accounting strategy based on spatial models. We propose a novel workflow for ecosystem services accounts, focused on assessment of the actual flow of ecosystem services, making a significant contribution to further development of the technical recommendations for ecosystem service

    Transitional cell carcinoma of suspected ureteral origin, with intra-abdominal and distant metastases in two horses

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    The present paper describes two cases of suspected urothelial carcinomas with local lymphatic metastases, and distant metastases in the lungs. In one case, liver metastases were also present. Both cases are documented with an extensive clinical report, using bloodwork, rectal examination, ultrasonography, cytology of abdominal fluid and, in one case, also urine analysis, radiography and transrectal biopsy to come to a diagnosis of abdominal malignancy. Subsequently, the post-mortem exam, histopathology and immunohistochemistry are described and illustrated

    Mapping and assessment of urban ecosystems and their services

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    Mapping and assessing ecosystems and their services is one of the key actions of the EU biodiversity strategy to 2020. In 2013 the MAES working group promoted six thematic pilots (focused on conservation status data, natural capital accounting and the main Europe’s ecosystems). In 2015 the MAES working group launched a new pilot on urban ecosystems. The thematic pilot on urban ecosystems has been structured in two phases, the first focuses on information collection and the second on the provision of systematic protocol for a spatially explicit assessment of ecosystems and their services in urban environment. This report presents the results the Pilot on Urban Ecosystems with an analysis of the outcomes of a survey and a literature review that were carried on between June and November of 2015. The survey was set up with the purpose of understanding the type of information that cities are currently applying in order to better incorporate Urban Green Infrastructure (UGI) and ecosystem services in decision making. The literature review was carried out to incorporate information on the research activity related to green infrastructure; conservation / biodiversity and ecosystem services in urban areas.JRC.H.8-Sustainability Assessmen

    Ecosystem services accounts: Valuing the actual flow of nature-based recreation from ecosystems to people

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    Natural capital accounting aims to measure changes in the stock of natural assets (i.e., soil, air, water and all living things) and to integrate the value of ecosystem services into accounting systems that will contribute to better ecosystems management. This study develops ecosystem services accounts at the European Union level, using nature-based recreation as a case study and following the current international accounting framework: System of Environmental-Economic Accounting – Experimental Ecosystem Accounting (SEEA EEA). We adapt and integrate different biophysical and socio-economic models, illustrating the workflow necessary for ecosystem services accounts: from a biophysical assessment of nature-based recreation to an economic valuation and compilation of the accounting tables. The biophysical assessment of nature-based recreation is based on spatially explicit models for assessing different components of ecosystem services: potential, demand and actual flow. Deriving maps of ecosystem service potential and demand is a key step in quantifying the actual flow of the service used, which is determined by the spatial relationship (i.e., proximity in the case of nature-based recreation) between service potential and demand. The nature-based recreation accounts for 2012 show an actual flow of 40 million potential visits to ‘high-quality areas for daily recreation’, with a total value of EUR 50 billion. This constitutes an important contribution of ecosystems to people's lives that has increased by 26% since 2000. Practical examples of ecosystem services accounts, as shown in this study, are required to derive recommendations and further develop the conceptual and methodological framework proposed by the SEEA EEA. This paper highlights the importance of using spatially explicit models for ecosystem services accounts. Mapping the different components of ecosystem services allows proper identification of the drivers of changes in the actual service flow derived from ecosystems, socio-economic systems and/or their spatial relationship. This will contribute to achieving one of the main goals of ecosystem accounts, namely measuring changes in natural capital, but it will also support decision-making that targets the enhancement of ecosystems, their services and the benefits they provide

    The plant-specific cyclin-dependent kinase CDKB1;1 and transcription factor E2Fa-DPa control the balance of mitotically dividing and endoreduplicating cells in Arabidopsis

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    Transgenic Arabidopsis thaliana plants overproducing the E2Fa-DPa transcription factor have two distinct cell-specific phenotypes: some cells divide ectopically and others are stimulated to endocycle. The decision of cells to undergo extra mitotic divisions has been postulated to depend on the presence of a mitosis-inducing factor (MIF). Plants possess a unique class of cyclin-dependent kinases (CDKs; B-type) for which no ortholog is found in other kingdoms. The peak of CDKB1;1 activity around the G2-M boundary suggested that it might be part of the MIF. Plants that overexpressed a dominant negative allele of CDKB1;1 underwent enhanced endoreduplication, demonstrating that CDKB1;1 activity was required to inhibit the endocycle. Moreover, when the mutant CDKB1;1 allele was overexpressed in an E2Fa-DPa–overproducing background, it enhanced the endoreduplication phenotype, whereas the extra mitotic cell divisions normally induced by E2Fa-DPa were repressed. Surprisingly, CDKB1;1 transcription was controlled by the E2F pathway, as shown by its upregulation in E2Fa-DPa–overproducing plants and mutational analysis of the E2F binding site in the CDKB1;1 promoter. These findings illustrate a cross talking mechanism between the G1-S and G2-M transition points

    The Arabidopsis thaliana checkpoint kinase WEE1 protects against premature vascular differentiation during replication stress

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    A sessile lifestyle forces plants to respond promptly to factors that affect their genomic integrity. Therefore, plants have developed checkpoint mechanisms to arrest cell cycle progression upon the occurrence of DNA stress, allowing the DNA to be repaired before onset of division. Previously, the WEE1 kinase had been demonstrated to be essential for delaying progression through the cell cycle in the presence of replication-inhibitory drugs, such as hydroxyurea. To understand the severe growth arrest of WEE1-deficient plants treated with hydroxyurea, a transcriptomics analysis was performed, indicating prolonged S-phase duration. A role for WEE1 during S phase was substantiated by its specific accumulation in replicating nuclei that suffered from DNA stress. Besides an extended replication phase, WEE1 knockout plants accumulated dead cells that were associated with premature vascular differentiation. Correspondingly, plants without functional WEE1 ectopically expressed the vascular differentiation marker VND7, and their vascular development was aberrant. We conclude that the growth arrest of WEE1-deficient plants is due to an extended cell cycle duration in combination with a premature onset of vascular cell differentiation. The latter implies that the plant WEE1 kinase acquired an indirect developmental function that is important for meristem maintenance upon replication stress
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