373 research outputs found

    The Smiley Faces task and how it can help teach some fundamentals for good clinical trials

    Get PDF
    Background: Many factors need to be considered when designing a clinical trial. Although structures such as PICOT (Population, Intervention, Comparator, Outcome, Timeline) are helpful, people with little or no prior knowledge can find designing and implementing a trial to be overly complicated. We developed a simple exercise to illustrate key features of trials: the Smiley Faces task.Aim: We describe how the Smiley Faces task can demonstrate the importance of good planning of trials and highlight pitfalls.Method and Results: The Smiley Faces task is centred on the simple, intuitive task to “draw a smiley face”. It requires no existing knowledge about trials or research generally, but can be used to highlight key features of a trial; such as formulating the research question; planning for coding, collection and analysis of data; handling of missing data and drawing of conclusions. We present insights from conducting the exercise dozens of times and collecting hundreds of smiley face drawings in a range of educational settings.Conclusion: The simplicity and accessibility of the task makes it relatively easy to demonstrate key points for careful planning of clinical trials. The approach is generalizable and applicable to researchers and teachers in a variety of medical settings

    Quantifying changes of wind speed distributions in the historical record of Atlantic tropical cyclones

    Get PDF
    Here we re-examine the official Atlantic basin tropical cyclone (hurricane) database HURDAT (1851–2008) and quantify differences between wind speed distributions in the early historical (1851–1943) record and more recent observations. Analyses were performed at three different geographical levels: for all six-hourly track segments of all Atlantic basin events, all segments of all events that crossed the US mainland, and US landfalling segments alone. At all three geographical levels of study, distributions of windspeeds over the last two, four and six decades display negligible dispersion or systematic change over time. On the other hand and relative to wind speed frequencies for subsequent years, the 1851–1943 record has a marked and statistically significant over-representation of wind speeds largely corresponding to Saffir-Simpson Categories 1 and 2 and under-representation of Categories 4 and 5 events; importantly, no single Category 5 event is recorded prior to 1924. The stability of the distribution of windspeeds at landfall over the last six decades, the dataset in which we can have most confidence, suggests that the differences in the earlier record are most likely explained by well-known measurement and observational deficiencies. Moreover by disaggregating the Power Dissipation Index (PDI), we demonstrate that the upward trend in Atlantic basin PDI since 1970s does not imply stronger and longer duration Category 5 windspeeds despite a warming climate. These results have implications for hurricane catastrophe loss modeling for the insurance industry and long-term trend analyses of the historical wind speed record, especially those related to the attribution of the role of Global Climate Change

    Signposts to Change by and for the rare disease community

    Get PDF
    A rare disease is defined as occurring in <1 in 2,000 people, but cumulatively rare diseases are common with one in 17 people in the UK being affected by a rare condition. The problems encountered because of the low number of instances of rare diseases are vast and need solutions. Thus improving communication mechanisms both within and around the healthcare system is of vital importance to individuals living and working with rare diseases.Surveys amongst people affected by and working with a rare disease have been, and will continue to be, carried out to establish what communication for them is like within the healthcare system. The DELPHI model will then be used to identify the priorities for improving communication for people with rare disease in Northern Ireland. From the survey data there were 60 priorities identified which have been grouped under 4 headings: Sources of Information, Medical Care, Rare Disease Community, and Public Awareness.There is a huge amount of progress which needs to be made in order to improve how someone with a rare disease receives information, treatment, and ultimately holistic care to help them deal with the life-changing event of discovering that they have a rare diseas

    Completely-Positive Non-Markovian Decoherence

    Full text link
    We propose an effective Hamiltonian approach to investigate decoherence of a quantum system in a non-Markovian reservoir, naturally imposing the complete positivity on the reduced dynamics of the system. The formalism is based on the notion of an effective reservoir, i.e., certain collective degrees of freedom in the reservoir that are responsible for the decoherence. As examples for completely positive decoherence, we present three typical decoherence processes for a qubit such as dephasing, depolarizing, and amplitude-damping. The effects of the non-Markovian decoherence are compared to the Markovian decoherence.Comment: 8 pages, 1 figur

    Estimating insured residential losses from large flood scenarios on the Tone River, Japan – a data integration approach

    Get PDF
    Flooding on the Tone River, which drains the largest catchment area in Japan and is now home to 12 million people, poses significant risk to the Greater Tokyo Area. In April 2010, an expert panel in Japan, the Central Disaster Prevention Council, examined the potential for large-scale flooding and outlined possible mitigation measures in the Greater Tokyo Area. One of the scenarios considered closely mimics the pattern of flooding that occurred with the passage of Typhoon Kathleen in 1947 and would potentially flood some 680 000 households above floor level. Building upon that report, this study presents a Geographical Information System (GIS)-based data integration approach to estimate the insurance losses for residential buildings and contents as just one component of the potential financial cost. Using a range of publicly available data – census information, location reference data, insurance market information and flood water elevation data – this analysis finds that insurance losses for residential property alone could reach approximately 1 trillion JPY (US$ 12.5 billion). Total insurance losses, including commercial and industrial lines of business, are likely to be at least double this figure with total economic costs being much greater again. The results are sensitive to the flood scenario assumed, position of levee failures, local flood depths and extents, population and building heights. The Average Recurrence Interval (ARI) of the rainfall following Typhoon Kathleen has been estimated to be on the order of 200 yr; however, at this juncture it is not possible to put an ARI on the modelled loss since we cannot know the relative or joint probability of the different flooding scenarios. It is possible that more than one of these scenarios could occur simultaneously or that levee failure at one point might lower water levels downstream and avoid a failure at all other points. In addition to insurance applications, spatial analyses like that presented here have implications for emergency management, the cost-benefit of mitigation efforts and land-use planning

    Strain Gradients in Epitaxial Ferroelectrics

    Get PDF
    X-ray analysis of ferroelectric thin layers of Ba1/2Sr1/2TiO3 with different thickness reveals the presence of internal strain gradients across the film thickness and allows us to propose a functional form for the internal strain profile. We use this to calculate the direct influence of strain gradient, through flexoelectric coupling, on the degradation of the ferroelectric properties of thin films with decreasing thickness, in excellent agreement with the observed behaviour. This work highlights the link between strain relaxation and strain gradients in epitaxial films, and shows the pressing need to avoid strain gradients in order to obtain thin ferroelectrics with bulk-like properties.Comment: 4 pages, 3 embedded figures (1 color), revTex

    Characteristics of the 14 April 1999 Sydney hailstorm based on ground observations, weather radar, insurance data and emergency calls

    Get PDF
    International audienceHailstorms occur frequently in metropolitan Sydney, in the eastern Australian State of New South Wales, which is especially vulnerable due to its building exposure and geographical location. Hailstorms challenge disaster response agencies and pose a great risk for insurance companies. This study focuses on the Sydney hailstorm of 14 April 1999 ? Australia's most expensive insured natural disaster, with supporting information from two other storms. Comparisons are drawn between observed hailstone sizes, radar-derived reflectivity and damage data in the form of insurance claims and emergency calls. The "emergency response intensity" (defined by the number of emergency calls as a proportion of the total number of dwellings in a Census Collection District) is a useful new measure of the storm intensity or severity experienced. The area defined by a radar reflectivity ?55 dBZ appears to be a good approximation of the damage swath on ground. A preferred area for hail damage is located to the left side of storm paths and corresponds well with larger hailstone sizes. Merging hail cells appear to cause a substantially higher emergency response intensity, which also corresponds well to maximum hailstone sizes. A damage threshold could be identified for hailstone sizes around 2.5 cm (1 cm), based on the emergency response intensity (insurance claims). Emergency response intensity and claims costs both correlate positively with hailstone sizes. Higher claim costs also occurred in areas that experienced higher emergency response intensities
    • …
    corecore