Comparison of signalized junction control strategies using individual vehicle position data

This paper is concerned with the development of control strategies for urban signalized junction that can make use of individual vehicle position data from localization probes on board the vehicles. Strategy development involves simulating the behaviour of vehicles as they negotiate junctions controlled by prototype strategies and evaluating performance. Two strategies are discussed in this paper, a simple auctioning agent strategy and an extended auctioning agent strategy where a machine learning approach is used to enable agents to be trained by a human expert to improve performance. The performance of these two strategies are compared with each other and with the MOVA algorithm in simulated tests. The results show that auctioning agents using individual vehicle position data can out perform MOVA, but that this performance can be improved further still by using learning auctioning agents trained by a human expert

Identifying and characterising price leadership in British supermarkets

Price leadership is a concept that lacks precision. We propose a deliberately narrow, falsifiable, definition and illustrate its feasibility using the two leading British supermarket chains. We find both firms engaging in leadership behaviour over a range of products, with the larger being somewhat more dominant but the smaller increasing leadership activity over time. Surprisingly, more price leadership events are price reductions than price increases, but the increases are of larger monetary amounts (so average price increases over time) and the events appear not necessarily related to cost changes. Price leadership appears to play some role in price increases

Price flexibility in British supermarkets

This paper delivers a significantly different empirical perspective on micro pricing behaviour and its impact on macroeconomic processes than previous studies. We examine a seven year period of pricing behaviour by the major British supermarkets encompassing the recession year 2008 and the partial recovery of 2009. Several of our findings run strongly counter to established empirical regularities, in particular the high overall frequency of regular or reference price changes we uncover, the greater intensity of change in more turbulent times and the numerical dominance of price falls over rises. The pricing behaviour revealed also significantly challenges the implicit assumption that prices are tracking cost changes

Pricing in inflationary times- the penny drops

We investigate micro pricing behaviour in groceries (the UK’s most important consumer market) over eight years including the inflationary period of early 2008. We find behaviour sharply distinguished from most previous work, namely that overall basket prices rise but more individual prices fall than rise! This is consistent with retailers obscuring the fact of rising basket prices. We employ a significant new source of data that captures cross-competitor interplay in prices at a very detailed level. Unusually but importantly, our work takes into account that consumers buy baskets of goods, rather than individual products, when shopping at supermarkets.

Optimal strategies for operating energy storage in an arbitrage or smoothing market

We characterize cost-minimizing operating strategies for an energy store over a given interval of time [0, T]. The cost functional here can represent, for example, a traditional economic cost or a penalty for time-variation of the output from a storage-assisted wind farm or more general imbalance between supply and demand. Our analysis allows for leakage, operating inefficiencies and general cost functionals. In the case where the cost of a store depends only on its instantaneous power output (or input), we present an algorithm to determine the optimal strategies. A key feature is that this algorithm is localized in time, in the sense that the action of the store at a time t ∈ [0, T] requires cost information over only some usually much shorter subinterval of time [t, tk] ⊂ [t, T]

Psychometric properties of the Hospital Survey on Patient Safety Culture: findings from the UK

Background: Patient safety culture is measured using a range of survey tools. Many provide limited data on psychometric properties and few report findings outside of the USA healthcare context. This study reports an assessment of the psychometric properties and suitability of the American Hospital Survey on Patient Safety Culture (HSOPC) for use within the UK. Methods: A questionnaire survey of three hospitals within a large UK Acute NHS Trust. 1,437 questionnaires were completed (37% response rate). Exploratory factor analysis, confirmatory factor analysis, and reliability analyses were carried out to assess the psychometric performance of this survey instrument and explore potential improvements. Results: Reliability analysis of the items within each proposed scale showed that over half failed to achieve satisfactory internal consistency (Cronbach’s Alpha < 0.7). Furthermore, a confirmatory factor analysis carried out on the UK dataset achieved a poor fit when compared to the original American model. An optimal measurement model was then constructed via exploratory and confirmatory factor analysis with split-half sample validation, and consisted of 9 dimensions compared to the original 12 in the American model. Conclusion: This is one of the few studies to provide an evaluation of an American patient safety culture survey using data from the UK. The results indicate that there is need for caution in using the HSOPC survey in the UK and underline the importance of appropriate validation of safety culture surveys before extending their usage to populations outside of the specific geographical and health care contexts in which they were developed

Antibiotics for exacerbations of asthma.

BACKGROUND: Asthma is a chronic respiratory condition that affects over 300 million adults and children worldwide. It is characterised by wheeze, cough, chest tightness, and shortness of breath. Symptoms typically are intermittent and may worsen over a short time, leading to an exacerbation. Asthma exacerbations can be serious, leading to hospitalisation or even death in rare cases. Exacerbations may be treated by increasing an individual's usual medication and providing additional medication, such as oral steroids. Although antibiotics are sometimes included in the treatment regimen, bacterial infections are thought to be responsible for only a minority of exacerbations, and current guidance states that antibiotics should be reserved for cases in which clear signs, symptoms, or laboratory test results are suggestive of bacterial infection. OBJECTIVES: To determine the efficacy and safety of antibiotics in the treatment of asthma exacerbations. SEARCH METHODS: We searched the Cochrane Airways Trials Register, which contains records compiled from multiple electronic and handsearched resources. We also searched trial registries and reference lists of primary studies. We conducted the most recent search in October 2017. SELECTION CRITERIA: We included studies comparing antibiotic therapy for asthma exacerbations in adults or children versus placebo or usual care not involving an antibiotic. We allowed studies including any type of antibiotic, any dose, and any duration, providing the aim was to treat the exacerbation. We included parallel studies of any duration conducted in any setting and planned to include cluster trials. We excluded cross-over trials. We included studies reported as full-text articles, those published as abstracts only, and unpublished data. DATA COLLECTION AND ANALYSIS: At least two review authors screened the search results for eligible studies. We extracted outcome data, assessed risk of bias in duplicate, and resolved discrepancies by involving another review author. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs), and continuous data as mean differences (MDs), all with a fixed-effect model. We described skewed data narratively. We graded the results and presented evidence in 'Summary of findings' tables for each comparison. Primary outcomes were intensive care unit/high dependence unit (ICU/HDU) admission, duration of symptoms/exacerbations, and all adverse events. Seconday outcomes were mortality, length of hospital admission, relapse after index presentation, and peak expiratory flow rate (PEFR). MAIN RESULTS: Six studies met our inclusion criteria and included a total of 681 adults and children with exacerbations of asthma. Mean age in the three studies in adults ranged from 36.2 to 41.2 years. The three studies in children applied varied inclusion criteria, ranging from one to 18 years of age. Five studies explicitly excluded participants with obvious signs and symptoms of bacterial infection (i.e. those clearly meeting current guidance to receive antibiotics). Four studies investigated macrolide antibiotics, and two studies investigated penicillin (amoxicillin and ampicillin) antibiotics; both studies using penicillin were conducted over 35 years ago. Five studies compared antibiotics versus placebo, and one was open-label. Study follow-up ranged from one to twelve weeks. Trials were of varied methodological quality, and we were able to perform only limited meta-analysis.None of the included trials reported ICU/HDU admission, although one participant in the placebo group of a study including children with status asthmaticus experienced a respiratory arrest and was ventilated. Four studies reported asthma symptoms, but we were able to combine results for only two macrolide studies of 416 participants; the MD in diary card symptom score was -0.34 (95% confidence interval (CI) -0.60 to -0.08), with lower scores (on a 7 point scale) denoting improved symptoms. Two macrolide studies reported symptom-free days. One study of 255 adults authors reported the percentage of symptom-free days at 10 days as 16% in the antibiotic group and 8% in the placebo group. In a further study of 40 children study authors reported significantly more symptom-free days at all time points in the antibiotic group compared with the usual care group. The same study reported the duration in days of the index asthma exacerbation, again favouring the antibiotic group. One study of a penicillin including 69 participants reported asthma symptoms at hospital discharge; the between-group difference for both studies was reported as non-significant.We combined data for serious adverse events from three studies involving 502 participants, but events were rare; the three trials reported only 10 events: five in the antibiotic group and five in the placebo group. We combined data for all adverse events (AEs) from three studies, but the effect estimate is imprecise (OR 0.99, 95% CI 0.69 to 1.43). No deaths were reported in any of the included studies.Two studies investigating penicillins reported admission duration; neither study reported a between-group difference. In one study (263 participants) of macrolides, two participants in each arm were reported as experiencing a relapse, defined as a further exacerbation, by the six-week time points. We combined PEFR endpoint results at 10 days for two macrolide studies; the result favoured antibiotics over placebo (MD 23.42 L/min, 95% CI 5.23 to 41.60). One study in children reported the maximum peak flow recorded during the follow-up period, favouring the clarithromycin group, but the confidence interval includes no difference (MD 38.80, 95% CI -11.19 to 88.79).Grading of outcomes ranged from moderate to very low quality, with quality of outcomes downgraded for suspicion of publication bias, indirectness, imprecision, and poor methodological quality of studies. AUTHORS' CONCLUSIONS: We found limited evidence that antibiotics given at the time of an asthma exacerbation may improve symptoms and PEFR at follow-up compared with standard care or placebo. However, findings were inconsistent across the six heterogeneous studies included, two of the studies were conducted over 30 years ago and most of the participants included in this review were recruited from emergency departments, limiting the applicability of findings to this population. Therefore we have limited confidence in the results. We found insufficient evidence about several patient-important outcomes (e.g. hospital admission) to form conclusions. We were unable to rule out a difference between groups in terms of all adverse events, but serious adverse events were rare

Patient safety culture among European cancer nurses - an exploratory, cross-sectional survey comparing data from Estonia, Germany, Netherlands and United Kingdom

Aim To explore the differences in perceived patient safety culture in cancer nurses working in Estonia, Germany, the Netherlands and the United Kingdom. Design An exploratory cross‐sectional survey. Methods In 2018, 393 cancer nurses completed the 12 dimensions of the Hospital Survey on Patient Safety Culture. Results The mean score for the overall patient safety grade was 61.3. The highest rated dimension was ‘teamwork within units' while ‘staffing' was the lowest in all four countries. Nurses in the Netherlands and in the United Kingdom, scored higher on ‘communication openness', the ‘frequency of events reported' and ‘nonpunitive response to errors', than nurses from Estonia or Germany. We found statistically significant differences between the countries for the association between five of the 12 dimensions with the overall patient safety grade: overall perception of patient safety, communication openness, staffing, handoffs and transitions and nonpunitive response to errors. Conclusion Patient safety culture, as reported by cancer nurses, varies between European countries and contextual factors, such as recognition of the nursing role and education have an impact on it. Cancer nurses' role in promoting patient safety is a key concern and requires better recognition on a European and global level

Identifying and characterising price leadership in British supermarkets

Price leadership is a concept that lacks precision. We propose a deliberately narrow, falsifiable, definition then develop it, illustrate its feasibility and test it using the two leading British supermarket chains. We find both firms engaging in leading prices upward over a range of products, with the larger being initially more dominant but the smaller increasing leadership activity to take overall leadership over time. However, more price leadership events are price reductions than price increases, consistently led by the smaller firm. Nevertheless, the increases are of larger monetary amounts than the falls, so average basket price increases over time