The Kalman-Bucy Filter for Integrable Levy Processes with Infinite Second Moment

We extend the Kalman-Bucy filter to the case where both the system and observation processes are driven by finite dimensional L´evy processes, but whereas the process driving the system dynamics is square-integrable, that driving the observations is not; however it remains integrable. The main result is that the components of the observation nose that have infinite variance make no contribution to the filtering equations. The key technique used is approximation by processes having bounded jumps

The implausibility of ‘usual care’ in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK)

Background: The power of the randomised controlled trial depends upon its capacity to operate in a closed system whereby the intervention is the only causal force acting upon the experimental group and absent in the control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems where factors relating to context, resources, interpretation and actions of individuals will affect implementation and effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may affect implementation and impact on the intervention. Methods: Using a fieldwork approach, we describe PICU context, ‘usual’ practice in sedation and weaning from mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using observation, individual and multi-disciplinary group interviews with staff. Results: Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9 % and 4 % of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39 % of PICUs engaging senior nurses in the process: weaning protocols were rarely used (9 % of PICUs). Weaning methods were variably based on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning readiness. Seventeen PICUs (74 %) had prior engagement in multi-centre trials, but limited research nurse availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision. Conclusions: We examined and identified contextual and organisational factors that may impact on the implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors we can more fully understand their impact on study outcomes

A national survey of anaesthetists' preferences for their own end of life care

Objectives: To describe individual views, wishes, and preferences for end of life care and to report UK anaesthetists' personal perspectives. / Methods: The ‘bigconversations’ questionnaire was developed by modifying an existing framework for end of life discussions. An online cross-sectional survey of UK anaesthetists was then conducted using the questionnaire in January 2019. / Results: The bigconversations questionnaire was validated as measuring the important aspects of end of life care by an expert panel and was found to have moderate test–retest reliability. Responses were received from 760/1913 (40%) of those invited to take part. Overall, 698/760 (92%) of respondents wished to be well informed about their condition and prognosis and 518/760 (68%) wanted to be heavily involved in decision-making about their health. Meanwhile, 639/760 (84%) of respondents would choose to forego treatment aimed at prolonging life should that life be of poor quality. The desire to spend time with family was a theme which arose from the qualitative analysis. / Conclusion: This study provides the first systematic description of UK doctors', specifically anaesthetists', personal preferences for end of life care. Broad trends were identified: to be well informed; to avoid high-intensity medical treatments if terminally unwell; to spend remaining time with family and friends; and to be symptom-free and well cared for. However, a substantial minority expressed different, indeed opposite, opinions. This variation highlights that good quality end of life care must be driven by discussion of an individual's values, wishes, and preferences

Identifying human waste contribution of phosphorus loads to domestic wastewater

This paper describes an approach to identify the phosphorus contribution of faeces and urine in domestic wastewater as part of a model verification exercise for a collaborative project between UK Water Industry Research (UKWIR), Scotland & Northern Ireland Forum for Environmental Research (SNIFFER) and UK Technical Advisory Group (UKTAG). The approach develops a methodology used in recent investigations by University of Abertay Dundee, by combining behaviour questionnaire with in sewer sampling and flow monitoring. The approach aimed to reduce the uncertainties associated with the apportionment of Total Phosphorus (TP) and Soluble Reactive Phosphorus (SRP) from domestic sources as identified during the literature review as part of the collaborative project. A domestic sub-catchment was identified which could be isolated, sampled and analysed to identify domestic contribution of SRP and TP load in domestic foul water. This data analysed with the results of product usage questionnaires, was used to verify a generic model developed to determine the significance of laundry and dishwasher phosphorus contributions to domestic wastewater. Conclusions were drawn regarding the effectiveness of this approach in identifying and quantifying the sources of phosphorus to wastewater treatment works

Stakeholder involvement in wastewater treatment design

The design option appraisal stage of new water industry capital investment projects involve greater levels of complexity than those generally encountered in other stages of the design process. It is at this stage that the issues related to sustainable development will be introduced, as decisions are multi-stakeholder and therefore decision criteria that reflect the views of a wide range of stakeholders with a range of different viewpoints need to be incorporated. This paper describes a case study which maps information flows, identifies decision criteria and evaluates the extent of stakeholder involvement in the design stage of a major UK wastewater system project. A mapping technique was developed to document and represent the flow of information during the decision making process. An in-depth study of the information flows enabled the researchers to establish the extent to which sustainability criteria were actually used. This was compared with recognised sustainability criteria identified in previous research involving the authors to allow an assessment of the effectiveness of stakeholder representation. Recommendations are given regarding ways of improving stakeholder involvement in water industry asset investment decisions

Domestic source of phosphorus to sewage treatment works.

Phosphorus is an element essential for life. Concerns regarding long-term security of supply and issues related to eutrophication of surface waters once released into the aquatic environment have led governments to consider and apply measures for reducing the use and discharge of phosphorus. Examples of source control include legislation to reduce phosphorus use in domestic detergents. This research shows that other domestic sources of phosphorus also contribute significantly to the domestic load to sewer and that overall, domestic sources dominate loads to sewage treatment works. Estimates provided here show that although the natural diet contributes 40% of the domestic phosphorus load, other potentially preventable sources contribute significantly to the estimated 44,000 tonnes of phosphorus entering UK sewage treatment works each year. In the UK, food additives are estimated to contribute 29% of the domestic load; automatic dishwashing detergents contribute 9% and potentially increasing; domestic laundry 14%, including contributions from phosphonates, but decreasing; phosphorus dosing to reduce lead levels in tap water 6%; food waste disposed of down the drain 1%; and personal care products 1%. Although UK data is presented here, it is anticipated that similar impacts would be expected for other developed economies. Consideration of alternatives to all preventable sources of phosphorus from these sources would therefore offer potentially significant reductions in phosphorus loads to sewage treatment works and hence to the aquatic environment. Combining all source control measures and applying them to their maximum extent could potentially lead to the prevention of over 22,000 tonnes-P/year entering sewage treatment works

Tax Professional Internships And Subsequent Professional Performance

How do internships influence the socialization and performance of accounting students employed in the tax department of a CPA firm?  Previous research on accounting internships primarily focuses on auditing personnel.  There is evidence in the literature that indicates audit and tax professionals have different work cultures.  This paper examines the relationship between internships and subsequent professional performance of tax professionals as measured by promotion velocity and employee turnover.  The human resource department, from seven regional CPA firms with similarly structured internship programs, provided performance, promotion and turnover data on employees who completed internships and employees who did not complete internships.  The results of the study indicate that internships positively affect performance evaluations, promotions, and employee retention of tax professionals