21 research outputs found

    Atomic oxygen patterning from a biomedical needle-plasma source

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    A ”plasma needle” is a cold plasma source operating at atmospheric pressure. Such sources interact strongly with living cells, but experimental studies on bacterial samples show that this interaction has a surprising pattern resulting in circular or annular killing structures. This paper presents numerical simulations showing that this pattern occurs because biologically active reactive oxygen and nitrogen species are produced dominantly where effluent from the plasma needle interacts with ambient air. A novel solution strategy is utilised coupling plasma produced neutral(uncharged) reactive species to the gas dynamics solving for steady state profiles at the treated biological surface. Numerical results are compared with experimental reports corroborating evidence for atomic oxygen as a key bactericidal species. Surface losses are considered for interaction of plasma produced reactants with reactive solid and liquid interfaces. Atomic oxygen surface reactions on a reactive solid surface with adsorption probabilities above 0.1 are shown to be limited by the flux of atomic oxygen from the plasma. Interaction of the source with an aqueous surface showed hydrogen peroxide as the dominant species at this interface

    The macroeconomic effects of banking crises: evidence from the United Kingdom, 1750–1938

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    This paper analyses the macroeconomic effects of banking crises in the United Kingdom between 1750 and 1938. We construct a new annual chronology of banking crises, which we define as episodes of runs and panics combined with significant, geographically-dispersed failures and suspensions. Using a vector autoregression, we find that banking crises are associated with short, sharp and significant drops in economic growth. Using the narrative record to identify plausibly exogenous variation, we show that this finding is robust to potential endogeneity

    Cyanobacterial ribosomal RNA genes with multiple, endonuclease-encoding group I introns

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    <p>Abstract</p> <p>Background</p> <p>Group I introns are one of the four major classes of introns as defined by their distinct splicing mechanisms. Because they catalyze their own removal from precursor transcripts, group I introns are referred to as autocatalytic introns. Group I introns are common in fungal and protist nuclear ribosomal RNA genes and in organellar genomes. In contrast, they are rare in all other organisms and genomes, including bacteria.</p> <p>Results</p> <p>Here we report five group I introns, each containing a LAGLIDADG homing endonuclease gene (HEG), in large subunit (LSU) rRNA genes of cyanobacteria. Three of the introns are located in the LSU gene of <it>Synechococcus </it>sp. C9, and the other two are in the LSU gene of <it>Synechococcus lividus </it>strain C1. Phylogenetic analyses show that these introns and their HEGs are closely related to introns and HEGs located at homologous insertion sites in organellar and bacterial rDNA genes. We also present a compilation of group I introns with homing endonuclease genes in bacteria.</p> <p>Conclusion</p> <p>We have discovered multiple HEG-containing group I introns in a single bacterial gene. To our knowledge, these are the first cases of multiple group I introns in the same <it>bacterial </it>gene (multiple group I introns have been reported in at least one phage gene and one prophage gene). The HEGs each contain one copy of the LAGLIDADG motif and presumably function as homodimers. Phylogenetic analysis, in conjunction with their patchy taxonomic distribution, suggests that these intron-HEG elements have been transferred horizontally among organelles and bacteria. However, the mode of transfer and the nature of the biological connections among the intron-containing organisms are unknown.</p

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    Wildcat Bankers or Political Failure? The Irish Financial Pantomime, 1797-1826

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    Using a new biography of banks, we examine the stability of Irish banking from 1797 to 1826 by constructing a failure rate series. We find that the ultimate cause of the frequent and severe banking crises was the crisis-prone structure of the banking system, which was designed to benefit the political elite. There is little evidence to suggest that wildcat banking or the failure of the Bank of Ireland to act as a lender of last resort were to blame. We also find that the main economic effect of the episodic crises was major diminutions in the money supply

    The Macroeconomic Effects of Banking Crises : Evidence from the United Kingdom, 1750-1938

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    This paper investigates the macroeconomic effects of UK banking crises over the period 1750 to 1938. We construct a new annual banking crisis series using bank failure rate data, which suggests that the incidence of banking crises was every 32 years. Using our new series and a narrative approach to identify exogenous banking crises, we find that industrial production contracts by 8.2 per cent in the year following a crisis. This finding is robust to a battery of checks, including different VAR specifications, different thresholds for the crisis indicator, and the use of a capital-weighted bank failure rate

    "It's disappointing and it's pretty frustrating, because it feels like it's something that will never go away." A qualitative study exploring individuals' beliefs and experiences of Achilles tendinopathy.

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    Achilles tendinopathy (AT) is a common and often persistent musculoskeletal disorder affecting both athletic and non-athletic populations. Despite the relatively high incidence there is little insight into the impact and perceptions of tendinopathy from the individual's perspective. Increased awareness of the impact and perceptions around individuals' experiences with Achilles tendinopathy may provide crucial insights for the management of what is often a complex, persistent, and disabling MSK disorder. To qualitatively explore the lived experiences of individuals with AT. A qualitative, interpretive description design was performed using semi-structured telephone interviews. Semi-structured interviews were conducted on 15 participants (8 male and 7 female) with AT. Thematic analysis was performed using the guidelines laid out by Braun and Clarke. The study has been reported in accordance with the consolidated criteria for reporting qualitative research (COREQ) checklist. Four main themes were identified from the data: 1) beliefs and perceptions surrounding AT: "If I'm over training or something, I don't really know", 2) the biopsychosocial impact of AT: "I think it restricts me in a lot of things that I would be able to do", 3) individuals' experiences with the management process: "You want it to happen now. You're doing all this stuff and it's just very slow progress", and 4) future prognosis and outlook in individuals with AT: "I see myself better". This study offers a unique insight into the profound impact and consequences of Achilles tendinopathy in a mixed sample of both athletic and non-athletic individuals. The findings of this study have important clinical implications. Specifically, it highlights the need for clinicians to recognize and adopt treatment approaches to embrace a more biopsychosocial approach for the management of tendinopathy.The Open Access publication of this article was funded by the Qatar National Library. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Atomic oxygen patterning from a biomedical needle-plasma source

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    A ”plasma needle” is a cold plasma source operating at atmospheric pressure. Such sources interact strongly with living cells, but experimental studies on bacterial samples show that this interaction has a surprising pattern resulting in circular or annular killing structures. This paper presents numerical simulations showing that this pattern occurs because biologically active reactive oxygen and nitrogen species are produced dominantly where effluent from the plasma needle interacts with ambient air. A novel solution strategy is utilised coupling plasma produced neutral(uncharged) reactive species to the gas dynamics solving for steady state profiles at the treated biological surface. Numerical results are compared with experimental reports corroborating evidence for atomic oxygen as a key bactericidal species. Surface losses are considered for interaction of plasma produced reactants with reactive solid and liquid interfaces. Atomic oxygen surface reactions on a reactive solid surface with adsorption probabilities above 0.1 are shown to be limited by the flux of atomic oxygen from the plasma. Interaction of the source with an aqueous surface showed hydrogen peroxide as the dominant species at this interface
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