54 research outputs found

    A statistical-process based approach for modelling beach profile variability

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    As the debate into a changing global climate continues, it is important that coastal engineers and scientists have the most advanced tools to quantify any resulting variation in the coastal environment. This will aid the creation and implementation of effective shoreline management plans to mitigate these changes. This thesis presents a new combined Statistical-Process based Approach (SPA) for modelling storm driven, cross-shore, beach profile variability at a medium-term (annual to decadal) timescale. The methodology presented involves combining the detailed statistical modelling of offshore storm data and a process based morphodynamic model (XBeach), to assess, and quantify, the medium-term morphodynamic response of cross-shore beach profiles. Up until now the use of process-based models has been curtailed at the storm event timescale. This approach allows inclusion of the post-storm recovery period, in addition to individual event impacts, thus allowing longer-term predictions. The use of a process-based model for simulating, both erosion and recovery, expands on previous work on the subject by allowing for the inclusion of antecedent beach profiles within the modelling framework. The XBeach model and the overall SPA procedure were calibrated and validated using measured wave and beach profile data from Narrabeen Beach, NSW, Australia. XBeach was shown to give a good prediction of the post-storm profile for four varying storm events. In addition, by accounting for the hydrodynamic processes that govern accretion, and calibrating parameters accordingly, XBeach was also shown to provide a good representation of berm accretion during recovery periods. The combination of the erosion and accretion models was shown to produce extremely encouraging results at an annual timescale, by successfully following the trends in beach volume and the position of the 0m and 2m beach contours. The simulation of a longer sequence provided comparable medium-term erosion return levels

    Spinal Cord Disease Due To Melioidosis

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    Acute leioidosis typically presents as severe pneumonia or septicaemia. Woods et al have described neurological presentations of melioidosis affecting the brainstem and affecting motor weakness. We describe a case of acute melioidosis which predominatly affected the spinal cord to produce paraplegia mimicking acute epidural abscess. The neurological lesions may have occurred in the setting of partially treated meningitis; however the cerebrospinal fluid was sterile and no radiological evidence of abscess was identified. It is possible that immune or toxin-mediated mechanisms may have contributed to the neurological damage, perhaps in the context of partially treated central nervous system infection

    Politics, 1641-1660

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    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Afterword: three letters

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    The essays consider issues of affect and emotion in terms of three early English letters - by Chaucer, the Paston family, and Henry VIII - in order to consider issues of the personal and the literary. It also comments on the volume of essays as a whole, and consider the field of the history of emotions and affect studies

    Creating and curating an archive: Bury St Edmunds and its Anglo-Saxon past

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    This contribution explores the mechanisms by which the Benedictine foundation of Bury St Edmunds sought to legitimise and preserve their spurious pre-Conquest privileges and holdings throughout the Middle Ages. The archive is extraordinary in terms of the large number of surviving registers and cartularies which contain copies of Anglo-Saxon charters, many of which are wholly or partly in Old English. The essay charts the changing use to which these ancient documents were put in response to threats to the foundation's continued enjoyment of its liberties. The focus throughout the essay is to demonstrate how pragmatic considerations at every stage affects the development of the archive and the ways in which these linguistically challenging texts were presented, re-presented, and represented during the Abbey’s history

    Stochastic simulation of daily streamflow sequences using a hidden Markov model

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    Estimation of daily streamflow time series is of paramount importance for the design and implementation of river engineering and management projects (e.g., restoration, sediment-transport modelling, hydropower). Traditionally, indirect approaches combining stochastic simulation of rainfall with hydrological rainfall–runoff models are used. However, these are limited by uncertainties in model calibration and computational expense. Thus, this paper demonstrates an alternative, direct approach, for stochastic modelling of daily streamflow data, specifically seeking to address well-known deficiencies in model capability to capture extreme flow events in the simulated time series. Combinations of a hidden Markov model (HMM) with the generalised extreme value (HMM-GEV) and generalised Pareto (HMM-GP) distributions were tested for four hydrologically contrasting catchments in the UK (Rivers Dee, Falloch, Caldew and Lud), with results compared to recorded flow data and estimations obtained from a simpler autoregressive-moving-average (ARMA) model. Results show that the HMM-GP method is superior in performance over alternative approaches (relative mean absolute differences (RMAD) of &amp;lt;2% across all catchments), appropriately captures extreme events and is generically applicable across a range of hydrological regimes. In contrast, the ARMA model was unable to capture the flow regime successfully (average RMAD of 14% across all catchments).</jats:p
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