57 research outputs found

    Towards a pricing strategy for the South African electricity supply and distribution industry

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    Bibliography: leaves 253-260.The purpose of this dissertation is to develop a strategy for electricity pricing in the South African electricity supply and distribution industry. To achieve this, the thesis focuses on three specific areas: Electricity pricing theory; past and present electricity pricing in South Africa; and a review of electricity pricing in the United Kingdom, France and Zimbabwe. Using this research as a basis, various thoughts are presented on a pricing strategy for the South African electricity industry. The essence of the strategy is that optimal pricing will occur in a truly competitive industry. The thesis does not seek to prove this hypothesis. Instead a three phase development process is proposed whereby electricity pricing in the South African industry may be transformed from its currently fragmented and decentralised position, to a state in which the force of fair competition will be the prime determinant of the pricing policy of the competing suppliers and distributors

    Updating predictive accident models of modern rural single carriageway A-roads

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    Reliable predictive accident models (PAMs) are essential to design and maintain safe road networks and yet the models most commonly used in the UK were derived using data collected 20 to 30 years ago. Given that the national personal injury accident total fell by some 30% in the last 25 years, while road traffic increased by over 60%, significant errors in scheme appraisal and evaluation based on the models currently in use seem inevitable. In this paper the temporal transferability of PAMs for modern rural single carriageway A-roads is investigated and their predictive performance is evaluated against a recent data set. Despite the age of these models, the PAMs for predicting the total accidents provide a remarkably good fit to recent data and these are more accurate than models where accidents are disaggregated by type. The performance of the models can be improved by calibrating them against recent data

    Dementia care mapping in long-term care settings: a systematic review of the evidence

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    YesThis systematic review identifies and reports the extent and nature of evidence to support the use of Dementia Care Mapping as an intervention in care settings. The review was limited to studies that used Dementia Care Mapping as an intervention and included outcomes involving either care workers and/or people living with dementia. Searches were conducted in PubMed, Web of Knowledge, CINAHL, PsychINFO, EBSCO and Scopus and manually from identified articles reference lists. Studies published up to January 2017 were included. Initial screening of identified papers was based on abstracts read by one author; full-text papers were further evaluated by a second author. The quality of the identified papers was assessed independently by two authors using the Cochrane Risk of Bias Tool. A narrative synthesis of quantitative findings was conducted. We identified 6 papers fulfilling predefined criteria. Studies consist of recent, large scale, good quality trials that had some positive impacts upon care workers’ stress and burnout and benefit people with dementia in terms of agitated behaviours, neuropsychiatric symptoms, falls and quality of life. Available research provides preliminary evidence that Dementia Care Mapping may benefit care workers and people living with dementia in care settings. Future research should build on the successful studies to date and use other outcomes to better understand the benefits of this intervention

    Exploring the NRO Opportunity for a Hubble-sized Wide-field Near-IR Space Telescope -- NEW WFIRST

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    We discuss scientific, technical and programmatic issues related to the use of an NRO 2.4m telescope for the WFIRST initiative of the 2010 Decadal Survey. We show that this implementation of WFIRST, which we call "NEW WFIRST," would achieve the goals of the NWNH Decadal Survey for the WFIRST core programs of Dark Energy and Microlensing Planet Finding, with the crucial benefit of deeper and/or wider near-IR surveys for GO science and a potentially Hubble-like Guest Observer program. NEW WFIRST could also include a coronagraphic imager for direct detection of dust disks and planets around neighboring stars, a high-priority science and technology precursor for future ambitious programs to image Earth-like planets around neighboring stars.Comment: 76 pages, 26 figures -- associated with the Princeton "New Telescope Meeting

    Norspermidine is not a self-produced trigger for biofilm disassembly

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    SummaryFormation of Bacillus subtilis biofilms, consisting of cells encapsulated within an extracellular matrix of exopolysaccharide and protein, requires the polyamine spermidine. A recent study reported that (1) related polyamine norspermidine is synthesized by B. subtilis using the equivalent of the Vibrio cholerae biosynthetic pathway, (2) exogenous norspermidine at 25 μM prevents B. subtilis biofilm formation, (3) endogenous norspermidine is present in biofilms at 50–80 μM, and (4) norspermidine prevents biofilm formation by condensing biofilm exopolysaccharide. In contrast, we find that, at concentrations up to 200 μM, exogenous norspermidine promotes biofilm formation. We find that norspermidine is absent in wild-type B. subtilis biofilms at all stages, and higher concentrations of exogenous norspermidine eventually inhibit planktonic growth and biofilm formation in an exopolysaccharide-independent manner. Moreover, orthologs of the V. cholerae norspermidine biosynthetic pathway are absent from B. subtilis, confirming that norspermidine is not physiologically relevant to biofilm function in this species

    Promoting Independence in Dementia (PRIDE): protocol for a feasibility randomised controlled trial.

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    BACKGROUND: Memory services often see people with early stage dementia who are largely independent and able to participate in community activities but who run the risk of reducing activities and social networks. PRIDE is a self-management intervention designed to promote living well and enhance independence for people with mild dementia. This study aims to examine the feasibility of conducting a definitive randomised trial comparing the clinical and cost-effectiveness of the PRIDE intervention offered in addition to usual care or with usual care alone. METHODS/DESIGN: PRIDE is a parallel, two-arm, multicentre, feasibility, randomised controlled trial (RCT). Eligible participants aged 18 or over who have mild dementia (defined as a score of 0.5 or 1 on the Clinical Dementia Rating Scale) who can participate in the intervention and provide informed consent will be randomised (1:1) to treatment with the PRIDE intervention delivered in addition to usual care, or usual care only. Participants will be followed-up at 3 and 6 month's post-randomisation. There will be an option for a supporter to join each participant. Each supporter will be provided with questionnaires at baseline and follow-ups at 3 to 6 months. Embedded qualitative research with both participants and supporters will explore their perspectives on the intervention investigating a range of themes including acceptability and barriers and facilitators to delivery and participation. The feasibility of conducting a full RCT associated with participant recruitment and follow-up of both conditions, intervention delivery including the recruitment, training, retention of PRIDE trained facilitators, clinical outcomes, intervention and resource use costs and the acceptability of the intervention and study related procedures will be examined. DISCUSSION: This study will assess whether a definitive randomised trial comparing the clinical and cost-effectiveness of whether the PRIDE intervention offered in addition to usual care is feasible in comparison to usual care alone, and if so, will provide data to inform the design and conduct of a future trial. TRIAL REGISTRATION: ISRCTN, ISRCTN11288961, registered on 23 October 2019, http://www.isrctn.com/ISRCTN12345678 Protocol V2.1 dated 19 June 2019

    Exploring the NRO Opportunity for a Hubble-Sized Wide-Field Near-IR Space Telescope - New WFIRST

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    We discuss scientific, technical, and programmatic issues related to the use of an NRO 2.4m telescope for the WFIRST initiative of the 2010 Decadal Survey. We show that this implementation of WFIRST, which we call "NEW WFIRST," would achieve the goals of the NWNH Decadal Survey for the WFIRST core programs of Dark Energy and Microlensing Planet Finding, with the crucial benefit of deeper and/or wider near-IR surveys for GO science and a potentially Hubble-like Guest Observer program. NEW WFIRST could also include a coronagraphic imager for direct detection of dust disks and planets around neighboring stars, a high-priority science and technology precursor for future ambitious programs to image Earth-like planets around neighboring stars

    Methodology for fitting and updating predictive accident models with trend

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    Reliable predictive accident models (PAMs) (also referred to as Safety Performance Functions (SPFs)) have a variety of important uses in traffic safety research and practice. They are used to help identify sites in need of remedial treatment, in the design of transport schemes to assess safety implications, and to estimate the effectiveness of remedial treatments. The PAMs currently in use in the UK are now quite old; the data used in their development was gathered up to 30 years ago. Many changes have occurred over that period in road and vehicle design, in road safety campaigns and legislation, and the national accident rate has fallen substantially. It seems unlikely that these ageing models can be relied upon to provide accurate and reliable predictions of accident frequencies on the roads today. This paper addresses a number of methodological issues that arise in seeking practical and efficient ways to update PAMs, whether by re-calibration or by re-fitting. Models for accidents on rural single carriageway roads have been chosen to illustrate these issues, including the choice of distributional assumption for overdispersion, the choice of goodness of fit measures, questions of independence between observations in different years, and between links on the same scheme, the estimation of trends in the models, the uncertainty of predictions, as well as considerations about the most efficient and convenient ways to fit the required models

    What works for whom in the management of diabetes in people living with dementia: a realist review

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    Background Dementia and diabetes mellitus are common long-term conditions and co-exist in a large number of older people. People living with dementia (PLWD) may be less able to manage their diabetes, putting them at increased risk of complications such as hypoglycaemia. The aim of this review was to identify key mechanisms within different interventions that are likely to improve diabetes outcomes in PLWD. Methods This is a realist review involving scoping of the literature and stakeholder interviews to develop theoretical explanations of how interventions might work, systematic searches of the evidence to test and develop the theories and their validation with a purposive sample of stakeholders. Twenty-six stakeholders — user/patient representatives, dementia care providers, clinicians specialising in diabetes or dementia and researchers — took part in interviews, and 24 participated in a consensus conference. Results We included 89 papers. Ten focused on PLWD and diabetes, and the remainder related to people with either dementia, diabetes or other long-term conditions. We identified six context-mechanism-outcome configurations which provide an explanatory account of how interventions might work to improve the management of diabetes in PLWD. This includes embedding positive attitudes towards PLWD, person-centred approaches to care planning, developing skills to provide tailored and flexible care, regular contact, family engagement and usability of assistive devices. An overarching contingency emerged concerning the synergy between an intervention strategy, the dementia trajectory and social and environmental factors, especially family involvement. Conclusions Evidence highlighted the need for personalised care, continuity and family-centred approaches, although there was limited evidence that this happens routinely. This review suggests there is a need for a flexible service model that prioritises quality of life, independence and patient and carer priorities. Future research on the management of diabetes in older people with complex health needs, including those with dementia, needs to look at how organisational structures and workforce development can be better aligned to their needs. Trial registration PROSPERO, CRD42015020625. Registered on 18 May 2015
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