70 research outputs found

    The hydrological impact of the Parangana Dam on the Mersey River, Tasmania

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    By diverting the waters of the Mersey River into a neighbouring basin, the Parangana Darn changed the hydrological character of the downstream river. The flow records of three gauging stations, located at 10, 67 and 88 km below the dam, provide the basis for identifying changes. Intermediate discharges have decreased the most and even at the furthest downstream station are 50% lower than before. The flow extremes, at both ends of the scale, have been less affected, and particularly the less frequent discharges which can be augmented by overspill. Indeed the highest flood on record, with a recurrence interval of over 500 years, occurred in the post-dam period. One-day and 30-day minimum flows are markedly lower downstream of the dam, but below the Dasher, the main tributary of the Mersey, they seem to recover and have almost regained pre-dam levels by the mouth. The entry of unregulated tributaries in the middle section separates a much changed upstream hydrology from a downstream one able to mitigate the worst effects of the dam except at intermediate discharges. In the upstream part, the physical, chemical and biological character of the river could be adversely affected by the altered flow regime, particularly in those reaches immediately below the dam

    Streamflow characteristics of northeastern Tasmania: I. regional flood flows

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    Based on streamflow records from thirteen stations, regional equations are developed which enable the estimation of mean annual discharge and various flood flows at ungauged sites along rivers in northeastern Tasmania. The area around Swansea is shown to be hydrologically distinct, at least as far as flood discharges are concerned, and the analysis subsequently focuses on the rest of the region. Despite the wide range of climatic and physiographic conditions there, relationships are highly significant, with drainage area explaining more than 97% of the variation in flood discharge. Rates of change are not only relatively high but increase with flood magnitude, suggesting rapid downstream transmission of flood waters. Network magnitude may be a viable alternative to drainage area as an estimator. Its use has the advantage that the downstream pattern of flow addition can be readily charted for major rivers, as illustrated for the Ringarooma and George

    Streamflow characteristics of northeastern Tasmania: II. Hydraulic geometry

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    Relationships describing the adjustment of water-surface width, mean depth and mean velocity to increasing discharge are calculated for eleven sections in northeastern Tasmania. The at-a-station graphs of two sections display distinct discontinuities related, however, to different causes - sub-bankfull channelization and the attainment of overbank stage. Despite intra-reach and inter-fluvial variations in hydraulic geometry, two types of response seem to be dominant, characterised by a high rate of change of either depth or velocity. Two sections do not fit into this pattern and, significantly, they tend to plot poorly on downstream graphs. Bankfull discharge probably lies between Q1.11 and Q2 at most sites, so both flows are used as reference discharges in analyses of downstream adjustment at the regional scale. The relations at Ql.ll and Q2 are quite similar and they are within the envelope defined by results from other areas. However, the data base is small and the scatter is large enough to render the velocity-discharge relation non-significant. The main residual from regression is the station on the South Esk at Perth which is used for discharge measurements at higher flows. Nevertheless, the hydraulic geometry equations enable estimates to be made of channel flow properties at ungauged sites within the northeastern river system

    Transmembrane signalling in eukaryotes: a comparison between higher and lower eukaryotes

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    A Novel Protein Kinase-Like Domain in a Selenoprotein, Widespread in the Tree of Life

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    Selenoproteins serve important functions in many organisms, usually providing essential oxidoreductase enzymatic activity, often for defense against toxic xenobiotic substances. Most eukaryotic genomes possess a small number of these proteins, usually not more than 20. Selenoproteins belong to various structural classes, often related to oxidoreductase function, yet a few of them are completely uncharacterised

    Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls

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    Background The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. Methods We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. Findings We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). Interpretation Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. Funding PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders

    Cohort Profile: Post-Hospitalisation COVID-19 (PHOSP-COVID) study

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    Transmembrane signalling in eukaryotes: a comparison between higher and lower eukaryotes

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