2,167 research outputs found

    A problem structuring method for ecosystem-based management : the DPSIR modelling process

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    The purpose of this paper is to learn from Complex Adaptive Systems (CAS) theory to inform the development of Problem Structuring Methods (PSMs) both in general and in the specific context of marine management. The focus on marine management is important because it is concerned with a CAS (formed through the interconnection between natural systems, designed systems and social systems) which exemplifies their particularly ‘wicked' nature. Recognition of this compels us to take seriously the need to develop tools for knowledge elicitation and structuring which meet the demands of CAS. In marine management, chief among those tools is the DPSIR (Drivers - Pressures - State Changes - Impacts - Responses) model and, although widely applied, the extent to which it is appropriate for dealing with the demands of a CAS is questionable. Such questioning is particularly pertinent in the context of the marine environment where there is a need to not only recognise a broad range of stakeholders (a question of boundary critique) but also to manage competing knowledge (economic, local and scientific) and value claims. Hence this paper emphasises how a CAS perspective might add impetus to the development of a critical perspective on DPSIR and PSM theory and practice to promote a more systemic view of decision-making and policy development

    Management of the marine environment: Integrating ecosystem services and societal benefits with the DPSIR framework in a systems approach

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    Ever increasing and diverse use of the marine environment is leading to human-induced changes in marine life, habitats and landscapes, making necessary the development of marine policy that considers all members of the user community and addresses current, multiple, interacting uses. Taking a systems approach incorporating an understanding of The Ecosystem Approach, we integrate the DPSIR framework with ecosystem services and societal benefits, and the focus this gives allows us to create a specific framework for supporting decision making in the marine environment. Based on a linking of these three concepts, we present a set of basic postulates for the management of the marine environment and emphasise that these postulates should hold for marine management to be achieved. We illustrate these concepts using two case studies: the management of marine aggregates extraction in UK waters and the management of marine biodiversity at Flamborough Head, UK. (C) 2010 Elsevier Ltd. All rights reserved

    On GELSEMINUM SEMPERVIRENS. (Continued From. P. 417.)

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    Molecular Diversity of Legume Root-Nodule Bacteria in Kakadu National Park, Northern Territory, Australia

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    BACKGROUND: Symbiotic relationships between leguminous plants (family Fabaceae) and nodule-forming bacteria in Australia native ecosystems remain poorly characterized despite their importance. Most studies have focused on temperate parts of the country, where the use of molecular approaches have already revealed the presence of Bradyrhizobium, Ensifer (formerly Sinorhizobium), Mesorhizobium and Rhizobium genera of legume root-nodule bacteria. We here provide the first molecular characterization of nodulating bacteria from tropical Australia. METHODOLOGY/PRINCIPAL FINDINGS: 45 nodule-forming bacterial strains, isolated from eight native legume hosts at eight locations in Kakadu National Park, Northern Territory, Australia, were examined for their genetic diversity and phylogenetic position. Using SSU rDNA PCR-RFLPs and phylogenetic analyses, our survey identified nine genospecies, two of which, Bradyrhizobium genospp. B and P, had been previously identified in south-eastern Australia and one, Mesorhizobium genospecies AA, in southern France. Three of the five newly characterized Bradyrhizobium genospecies were more closely related to B. japonicum USDA110, whereas the other two belonged to the B. elkanii group. All five were each more closely related to strains sampled in various tropical areas outside Australia than to strains known to occur in Australia. We also characterized an entirely novel nodule-forming lineage, phylogenetically distant from any previously described rhizobial and non-rhizobial legume-nodulating lineage within the Rhizobiales. CONCLUSIONS/SIGNIFICANCE: Overall, the present results support the hypothesis of tropical areas being centres of biodiversity and diversification for legume root-nodule bacteria and confirm the widespread occurrence of Bradyrhizobium genosp. B in continental Australia

    Analysis of Oct4-dependent transcriptional networks regulating self-renewal and pluripotency in human embryonic stem cells

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    The POU domain transcription factor OCT4 is a key regulator of pluripotency in the early mammalian embryo and is highly expressed in the inner cell mass of the blastocyst. Consistent with its essential role in maintaining pluripotency, Oct4 expression is rapidly downregulated during formation of the trophoblast lineage. To enhance our understanding of the molecular basis of this differentiation event in humans, we used a functional genomics approach involving RNA interference-mediated suppression of OCT4 function in a human ESC line and analysis of the resulting transcriptional profiles to identify OCT4-dependent genes in human cells. We detected altered expression of >1,000 genes, including targets regulated directly by OCT4 either positively (NANOG, SOX2, REX1, LEFTB, LEFTA/EBAF DPPA4, THY1, and TDGF1) or negatively (CDX2, EOMES, BMP4, TBX18, Brachyury [T], DKK1, HLX1, GATA6, ID2, and DLX5), as well as targets for the OCT4-associated stem cell regulators SOX2 and NANOG. Our data set includes regulators of ACTIVIN, BMP, fibroblast growth factor, and WNT signaling. These pathways are implicated in regulating human ESC differentiation and therefore further validate the results of our analysis. In addition, we identified a number of differentially expressed genes that are involved in epigenetics, chromatin remodeling, apoptosis, and metabolism that may point to underlying molecular mechanisms that regulate pluripotency and trophoblast differentiation in humans. Significant concordance between this data set and previous comparisons between inner cell mass and trophectoderm in human embryos indicates that the study of human ESC differentiation in vitro represents a useful model of early embryonic differentiation in humans

    Oil and gas infrastructure decommissioning in marine protected areas: System complexity, analysis and challenges

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    Many offshore oil and gas production facilities are nearing the end of their operational life, with decommissioning now becoming a global challenge. The compatibility of decommissioning operations to marine protected areas (MPAs) creates further challenges. The recently-developed DAPSI(W)R(M) problem structuring framework (covering Drivers, Activities, Pressures, State changes, Impacts (on Welfare) and Responses (as Measures)) was applied here to interrogate the complexity of decommissioning oil and gas infrastructure within MPAs, with outputs feeding into the development of a novel database tool for Screening Potential Impacts of Decommissioning Activities (SPIDA). In meeting the current requirements of the marine regulatory regime, SPIDA provides a more streamlined, evidence-based process which can be applied by industry, statutory nature conservation bodies and regulators for identifying and evaluating evidence that supports the implications of decommissioning alternatives on the condition of MPAs. SPIDA has been developed to be adapted for other activities and sectors, including offshore renewables

    Disease influences host population growth rates in a natural wild plant-pathogen association over a 30-year period

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    1. The epidemiological and demographic dynamics of plant-pathogen interactions in natural environments are strongly affected by spatial and temporal influences. Here we assess the interaction between Filipendula ulmaria and its rust pathogen Triphragmium ulmariae by analysing a 30-year long dataset that has followed pathogen and plant population dynamics in a metapopulation of similar to 230 host patches growing on islands of the Skeppsvik archipelago in northern Sweden.2. Over this period, the host metapopulation initially expanded in both number and size of individual patches before plateauing. In contrast, the pathogen metapopulation showed greater change. Disease incidence showed a convex pattern rising for the first decade before showing a marked decline in the last decade. At the same time, the prevalence of disease in infected populations showed a constant 30-year long decline.3. At the individual host population level, each population was annually classified into one of four inter-year states: healthy, recolonization, extinction and diseased. Host populations that were healthy from 1 year to the next were significantly smaller than all other host population categories, while host populations in which disease was constantly present were significantly larger.4. Host populations in which the pathogen underwent either an extinction or a recolonization event were of similar size and represented a measure of the host threshold size for long-term pathogen survival.5. Host population growth rates declined as disease levels increased. The growth rate of host populations in which disease was continuously present was 75% lower than in populations that were free disease.6. The sensitivity of the association to climate change as demonstrated through a decline in disease incidence and prevalence and an increase in drought damage to plant populations as temperatures rise has only become apparent through analysis of an extensive long-term dataset.7. Synthesis. To date wild plant-pathogen studies have focused on the epidemiology of the pathogen and its effect on individual plant fitness. Here we have established a link to the impact of the pathogen on the long-term dynamics of host populations. This has the potential to trigger a cascade of changes in the species composition and diversity of communities
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