Development of an improved ramped pyrolysis method for radiocarbon dating and application to Antarctic sediments

Archives of the retreat history of the Antarctic Ice Sheet since the Last Glacial Maximum (~20,000 years ago) are preserved in marine sediment cores from around the margins of Antarctica, but accurate dating methods remain elusive in many areas. Radiocarbon dating of key lithofacies transitions indicative of grounding-line retreat is problematic due to pervasive reworking issues in glacimarine sediments. Bulk sediment material can be radiocarbon dated but yields ages which are not indicative of the time of sedimentation due to the presence of reworked carbon material from pre-Last Glacial Maximum times. Consequently, development of methods to date only the autochthonous carbon component of these sediments are required to date the retreat of the Last Glacial Maximum ice sheet in Antarctica. A new radiocarbon dating capability has been developed at Rafter Radiocarbon Laboratory (RRL), National Isotope Centre, GNS Science, Lower Hutt, in the course of this study. This has entailed designing, building and testing a ramped pyrolysis (RP) system, in which sedimentary material is heated from ambient to ~1000oC in the absence of oxygen (pyrolysed), with the carbon liberated during pyrolysis being combined with oxygen at a temperature of ~800oC to produce CO2. The amount of CO2 produced is measured by a gas analyser and the CO2 is captured in a vacuum line. The method exploits the thermochemical behaviour of degraded organic carbon. Organic carbon which has been least degraded with time breaks down earliest under pyrolysis, so CO2 captured from this fraction most closely approximates the time of deposition of the sediment. CO2 captured at higher temperatures represents more degraded carbon-containing fractions and yields older ages. The RP system includes a gas delivery system to deliver ultra-high purity He (carrier gas) and O2, a furnace system in which to pyrolyse sample material and oxidise the liberated carbon, a CO2 detection system to measure the CO2 produced and a vacuum line system to enable simultaneous collection and processing of CO2. The RRL system was based on the design developed by Dr Brad Rosenheim (University of South Florida (USF)), the originator of the first RP system at the National Ocean Sciences AMS Facility (Woods Hole Oceanographic Institution, Massachusetts, USA), who also provided guidance in this thesis. As part of the study, a visit to USF was undertaken, with sediment samples from Crystal Sound, Antarctic Peninsula being processed in the USF RP system. CO2 collected from RP processing was radiocarbon dated at RRL. The scope of this thesis was to develop and build the RRL RP system, and numerous tests were conducted during this process and are presented in this thesis. As part of this, sediment samples from Crystal Sound were also processed on the RRL RP system, and an interlaboratory comparison was conducted on the same materials processed independently through both the USF and RRL RP systems. In the development and testing of the RRL system, numerous issues were identified and a set of operating protocols developed. Due to time constraints and the scope of this thesis, interlaboratory comparisons were limited in number, but initial results show good reproducibility, and that ramped pyrolysis captured significantly younger carbon populations in both the USF and RRL RP systems than methods using bulk sediment dating alone. Within uncertainties, the ages of the youngest and oldest splits from RP processing of the same material on both systems were indistinguishable

The Drosophila anatomy ontology.

BACKGROUND: Anatomy ontologies are query-able classifications of anatomical structures. They provide a widely-used means for standardising the annotation of phenotypes and expression in both human-readable and programmatically accessible forms. They are also frequently used to group annotations in biologically meaningful ways. Accurate annotation requires clear textual definitions for terms, ideally accompanied by images. Accurate grouping and fruitful programmatic usage requires high-quality formal definitions that can be used to automate classification and check for errors. The Drosophila anatomy ontology (DAO) consists of over 8000 classes with broad coverage of Drosophila anatomy. It has been used extensively for annotation by a range of resources, but until recently it was poorly formalised and had few textual definitions. RESULTS: We have transformed the DAO into an ontology rich in formal and textual definitions in which the majority of classifications are automated and extensive error checking ensures quality. Here we present an overview of the content of the DAO, the patterns used in its formalisation, and the various uses it has been put to. CONCLUSIONS: As a result of the work described here, the DAO provides a high-quality, queryable reference for the wild-type anatomy of Drosophila melanogaster and a set of terms to annotate data related to that anatomy. Extensive, well referenced textual definitions make it both a reliable and useful reference and ensure accurate use in annotation. Wide use of formal axioms allows a large proportion of classification to be automated and the use of consistency checking to eliminate errors. This increased formalisation has resulted in significant improvements to the completeness and accuracy of classification. The broad use of both formal and informal definitions make further development of the ontology sustainable and scalable. The patterns of formalisation used in the DAO are likely to be useful to developers of other anatomy ontologies

Using collaborative hackathons to coproduce knowledge on local climate adaptation governance

While coproduction of knowledge is growing in popularity in social sciences, and especially climate change research, we still need to better understand how to coproduce climate knowledge. In this paper, we explore how collaborative climate hackathons coproduce local adaptation knowledge, and what this method reveals about local climate governance. The data derives from two collaborative climate hackathons, called Klimathons, that attracted 73 and 98 participants in Bergen, Norway. The participants were practitioners and decision-makers from local, regional, and national institutions as well as researchers from natural and social climate sciences. The collaborative group work revolved around the challenges and solutions of local adaptation planning and uncovered how a diversity of key actors understand the local adaptation work in Norway. These interventions revealed that there are significant disagreements and divergent understanding of relevant laws, regulations and responsibility between practitioners working within the same governance system. Though the cross-sectorial interaction does not dissolve these divergences, they allow actors to renegotiate boundaries between divergent knowledge communities. The Klimathons helped us navigate the complexity of local climate adaptation by shifting the focus to how different actors make sense of and work on adaptation and showing the intertwining and interdependence of potential drivers for adaptation.publishedVersio

The Alice Springs Hospital Readmission Prevention Project (ASHRAPP): a randomised control trial

Background: Hospitals are frequently faced with high levels of emergency department presentations and demand for inpatient care. An important contributing factor is the subset of patients with complex chronic diseases who have frequent and preventable exacerbations of their chronic diseases. Evidence suggests that some of these hospital readmissions can be prevented with appropriate transitional care. Whilst there is a growing body of evidence for transitional care processes in urban, non-indigenous settings, there is a paucity of information regarding rural and remote settings and, specifically, the indigenous context. Methods: This randomised control trial compares a tailored, multidimensional transitional care package to usual care. The objective is to evaluate the efficacy of the transitional care package for Indigenous and non-Indigenous Australian patients with chronic diseases at risk of recurrent readmission with the aim of reducing readmission rates and improving transition to primary care in a remote setting. Patients will be recruited from medical and surgical admissions to Alice Springs Hospital and will be followed for 12 months. The primary outcome measure will be number of admissions to hospital with secondary outcomes including number of emergency department presentations, number of ICU admissions, days alive and out of hospital, time to primary care review post discharge and cost-effectiveness. Discussion: Successful transition from hospital to home is important for patients with complex chronic diseases. Evidence suggests that a coordinated transitional care plan can result in a reduction in length of hospital stay and readmission rates for adults with complex medical needs. This will be the first study to evaluate a tailored multidimensional transitional care intervention to prevent readmission in Indigenous and non-Indigenous Australian residents of remote Australia who are frequently admitted to hospital. If demonstrated to be effective it will have implications for the care and management of Indigenous Australians throughout regional and remote Australia and in other remote, culturally and linguistically diverse populations and settings

Mixed-methods feasibility cluster randomised controlled trial of a paramedic-administered breathlessness management intervention for acute-on-chronic breathlessness (BREATHE): Study findings

Introduction: One-fifth of emergency department presentations by ambulance are due to acute-on-chronic breathlessness. We explored the feasibility of an evaluation-phase, cluster randomised controlled trial (cRCT) of the effectiveness and cost-effectiveness of a paramedic-administered, non-pharmacological breathlessness intervention for people with acute-on-chronic breathlessness at ambulance call-out (BREATHE) regarding breathlessness intensity and conveyance to hospital.Methods: This mixed-methods, feasibility cRCT (ISRCTN80330546), randomised paramedics to usual care or intervention plus usual care. Retrospective patient consent to use call-out data (primary endpoint) and prospective patient/carer consent for follow-up was sought. Potential primary outcomes included breathlessness intensity (numerical rating scale) and conveyance. Follow-up included: interviews with patients/carers and questionnaires at 14 days, 1 and 6 months; paramedic focus groups and surveys.Results: Recruitment was during COVID-19, with high demands on paramedics and fewer call-outs by eligible patients. We enrolled 29 paramedics; nine withdrew. Randomisation/trial procedures were acceptable. Paramedics recruited thirteen patients, not meeting recruitment target (n=36); eight patients and three carers were followed up. Data quality was good but insufficient for future sample size estimation.The intervention did not extend call-out time, was delivered with fidelity and was acceptable to patients, carers and paramedics. There were no repeat call-outs within 48 hours. All trained paramedics strongly recommended BREATHE as a highly relevant, simple intervention. Conclusion: Patient recruitment to target was not feasible during the pandemic. Training and intervention were acceptable and delivered with fidelity. Results include valuable information on recruitment, consent, attrition, and data collection that will inform the design and delivery of a definitive trial

Risk of bleeding amongst warfarin and direct oral anticoagulant users prescribed immediate antibiotics for respiratory tract infection: cohort study

Purpose: Incidence of bleeding amongst warfarin and direct oral anticoagulant (DOAC) users is greater following a respiratory tract infection (RTI). It is unclear whether immediate antibiotics modify this association. We estimated the risk of bleeding amongst warfarin and DOAC users with RTI by antibiotic treatment. Methods: This retrospective cohort study used data from the Clinical Practice Research Datalink (CPRD) GOLD for adults in England prescribed warfarin or a DOAC, who sought primary care for an RTI between 1st January 2011 and 31st December 2019. Outcomes were major bleeding (hospital admission for intracranial or gastrointestinal bleeding), and non‐major bleeding (hospital admission or General Practice consult for epistaxis, haemoptysis, or haematuria). Cox models derived hazard ratios (HRs) and 95% confidence intervals (CIs) for each outcome, adjusting for confounders using inverse probability of treatment weighting. Results: Of 14 817 warfarin and DOAC users consulting for an RTI, 8768 (59%) were prescribed immediate antibiotics and 6049 (41%) were not. Approximately 49% were female, and median age was 76 years. Antibiotics were associated with reduced risk of major bleeding (adjusted HR 0.38, 95% CI 0.25 to 0.58). This was consistent across several sensitivity analyses. Antibiotics were also associated with a reduced risk of non‐major bleeding (adjusted HR 0.78, 95% CI 0.61 to 0.99). Conclusions: Immediate antibiotics were associated with reduced risk of bleeding amongst warfarin and DOAC users with an RTI. Further work is needed to understand mechanisms and confirm whether a lower threshold for antibiotic use for RTI in this population may be beneficial