3,754 research outputs found

    Pulmonary artery thrombosis in a patient with right-sided heart failure

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    Pulmonary thromboembolism occurring either abruptly or insidious poses a greater challenge in diag-nosis. A high index of suspicion is required to proceed with proper investigations in patients with nonspecific cardiac or respiratory presentation to make the diagnosis of pulmonary embolism (PE). Early diagnosis of PE with prompt initiating of anticoagulation therapy has been proven to have a pos-itive impact in mortality reduction associated with recurrent episodes of this condition. We present a case of a 76-year-old man, known to have cardiac failure on regular treatment who presented with predominant features of right-sided heart failure accompanied with dizziness. He was diagnosed to have pulmonary artery thrombosis by computerized tomography. Anticoagulation therapy was initiated with marked clinical improvement.Key words: Chronic pulmonary artery thrombosis, computerized tomography, right.sided heart failur

    Knowledge Matters: The Potential Contribution of the Coproduction of Research

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    The purpose of this paper is to share our experiences—as academics and professionals—in coproducing knowledge to improve urban development outcomes in the global South. The focus of the paper is on urban research and practice, a field in which academic work influences policy and programming, and professional knowledge (validated and certified by academic institutions) forms the basis for urban planning and management. Collaborative research coproduced with social movement activities highlights that four issues need to be addressed to establish more equitable relations. First, alternative theories of change about how research leads to social transformation must be recognised, even if they cannot be reconciled. Second, the contribution of social movement leaders to university teaching needs to be institutionalised. Third, the relative status of academics vis-à-vis non-academics must be interrogated and better understood. Fourth, the accountabilities of the researchers to the marginalised need to be established. We argue that academics are insufficiently self-critical about the power dynamics involved in knowledge production with social movements. And that long-term relations enable understandings to be built and some of these tensions to be alleviated. Our conclusion highlights the unequal power relations that under-pin these challenges and suggests some steps to address these inequalities and their negative consequences

    Knowledge Matters: The Potential Contribution of the Coproduction of Research

    Get PDF
    The purpose of this paper is to share our experiences—as academics and professionals—in coproducing knowledge to improve urban development outcomes in the global South. The focus of the paper is on urban research and practice, a field in which academic work influences policy and programming, and professional knowledge (validated and certified by academic institutions) forms the basis for urban planning and management. Collaborative research coproduced with social movement activities highlights that four issues need to be addressed to establish more equitable relations. First, alternative theories of change about how research leads to social transformation must be recognised, even if they cannot be reconciled. Second, the contribution of social movement leaders to university teaching needs to be institutionalised. Third, the relative status of academics vis-à-vis non-academics must be interrogated and better understood. Fourth, the accountabilities of the researchers to the marginalised need to be established. We argue that academics are insufficiently self-critical about the power dynamics involved in knowledge production with social movements. And that long-term relations enable understandings to be built and some of these tensions to be alleviated. Our conclusion highlights the unequal power relations that under-pin these challenges and suggests some steps to address these inequalities and their negative consequences

    Global Taxonomic Diversity of Anomodonts (Tetrapoda, Therapsida) and the Terrestrial Rock Record Across the Permian-Triassic Boundary

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    The end-Permian biotic crisis (∼252.5 Ma) represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids (‘mammal-like reptiles’), through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals that anomodonts experienced three distinct phases of diversification interrupted by the same number of extinctions, i.e. an end-Guadalupian, an end-Permian, and a mid-Triassic extinction. A positive correlation between the number of taxa and the number of formations per time interval shows that anomodont diversity is biased by the Permian-Triassic terrestrial rock record. Normalized diversity curves indicate that anomodont richness continuously declines from the Middle Permian to the Late Triassic, but also reveals all three extinction events. Taxonomic rates (origination and extinction) indicate that the end-Guadalupian and end-Permian extinctions were driven by increased rates of extinction as well as low origination rates. However, this pattern is not evident at the final decline of anomodont diversity during the Middle Triassic. Therefore, it remains unclear whether the Middle Triassic extinction represents a gradual or abrupt event that is unique to anomodonts or more common among terrestrial tetrapods. The end-Permian extinction represents the most distinct event in terms of decline in anomodont richness and turnover rates

    Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami

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    The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNa V 1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1-S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species

    Isolation of two insecticidal toxins from venom of the Australian theraphosid spider Coremiocnemis tropix

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    © 2016 Elsevier Ltd Sheep flystrike is caused by parasitic flies laying eggs on soiled wool or open wounds, after which the hatched maggots feed on the sheep flesh and often cause large lesions. It is a significant economic problem for the livestock industry as infestations are difficult to control due to ongoing cycles of larval development into flies followed by further egg laying. We therefore screened venom fractions from the Australian theraphosid spider Coremiocnemis tropix to identify toxins active against the sheep blowfly Lucilia cuprina, which is the primary cause of flystrike in Australia. This screen led to isolation of two insecticidal peptides, Ct1a and Ct1b, that are lethal to blowflies within 24 h of injection. The primary structure of these peptides was determined using a combination of Edman degradation and sequencing of a C. tropix venom-gland transcriptome. Ct1a and Ct1b contain 39 and 38 amino acid residues, respectively, including six cysteine residues that form three disulfide bonds. Recombinant production in bacteria (Escherichia coli) resulted in low yields of Ct1a whereas solid-phase peptide synthesis using native chemical ligation produced sufficient quantities of Ct1a for functional analyses. Synthetic Ct1a had no effect on voltage-gated sodium channels from the American cockroach Periplanata americana or the German cockroach Blattella germanica, but it was lethal to sheep blowflies with an LD50 of 1687 pmol/g

    FEL research and development at STFC Daresbury laboratory

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    In this paper we present an overview of current and proposed FEL developments at STFC Daresbury Laboratory in the UK. We discuss progress on the ALICE IR-FEL since first lasing in October 2010, covering the optimisation of the FEL performance, progress on the demonstration of a single shot cross correlation experiment and the results obtained so far with a Scanning Near-Field Optical Microscopy beamline. We discuss a proposal for a 250 MeV single pass FEL test facility named CLARA to be built at Daresbury and dedicated to research for future light source applications. Finally we present a brief overview of other recent research highlights

    Friendship as a Political Concept: A Groundwork for Analysis

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    What kind of a concept is friendship, and what is its connection to politics? Critics sometimes claim that friendship does not have a role to play in the study of politics. Such objections misconstrue the nature of the concept of friendship and its relation to politics. In response, this article proposes three approaches to understanding the concept of friendship: (1) as a ‘family resemblance’ concept, (2) as an instance of an ‘essentially contested’ concept, and (3) as a concept indicating a problématique. The article thus responds to the dismissal of friendship by undertaking the groundwork for understanding what kind of a concept friendship might be, and how it might serve different purposes. In doing so, it opens the way for understanding friendship’s relation to politics
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