45,794 research outputs found

    Unethical aspects of homeopathic dentistry

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    In the last year there has been a great deal of public debate about homeopathy, the system of alternative medicine whose main principles are that like cures like and that potency increases relative to dilution. The House of Commons Select Committee on Science and Technology concluded in November 2009 that there is no evidence base for homeopathy, and agreed with some academic commentators that homeopathy should not be funded by the NHS. While homeopathic doctors and hospitals are quite commonplace, some might be surprised to learn that there are also many homeopathic dentists practising in the UK. This paper examines the statements made by several organisations on behalf of homeopathic dentistry and suggests that they are not entirely ethical and may be in breach of various professional guidelines

    Resolving discrete pulsar spin-down states with current and future instrumentation

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    An understanding of pulsar timing noise offers the potential to improve the timing precision of a large number of pulsars as well as facilitating our understanding of pulsar magnetospheres. For some sources, timing noise is attributable to a pulsar switching between two different spin-down rates (ν˙)(\dot{\nu}). Such transitions may be common but difficult to resolve using current techniques. In this work, we use simulations of ν˙\dot{\nu}-variable pulsars to investigate the likelihood of resolving individual ν˙\dot{\nu} transitions. We inject step-changes in the value of ν˙\dot{\nu} with a wide range of amplitudes and switching timescales. We then attempt to redetect these transitions using standard pulsar timing techniques. The pulse arrival-time precision and the observing cadence are varied. Limits on ν˙\dot{\nu} detectability based on the effects such transitions have on the timing residuals are derived. With the typical cadences and timing precision of current timing programs, we find we are insensitive to a large region of Δν˙\Delta \dot{\nu} parameter space which encompasses small, short timescale switches. We find, where the rotation and emission states are correlated, that using changes to the pulse shape to estimate ν˙\dot{\nu} transition epochs, can improve detectability in certain scenarios. The effects of cadence on Δν˙\Delta \dot{\nu} detectability are discussed and we make comparisons with a known population of intermittent and mode-switching pulsars. We conclude that for short timescale, small switches, cadence should not be compromised when new generations of ultra-sensitive radio telescopes are online.Comment: 19 pages, 11 figure

    Fact and fiction.

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    Fact and Fiction was an exhibition of prints and 3D works which examine, question and challenge accepted truths, assumptions and beliefs (political,religious,scientific). Irony, paradox and contradiction both visual and textual being the modus of each of these works. The prints are digital the 3D works are mixed media including, ply, polyester resin, plaster, screen printed plexiglass

    A study of vegetable sourced colourants for use in screen process ink production

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    The following investigation aims to determine the potential of plant material to produce pigments capable of acting as alternatives to the standard range of process (CMYK) colours used in screen printing. A review of the literature on so-called `natural dyes' reveals the extent of the pre-synthetic (1857) use of a range of dye-plants in the textile and related industries over a period of many centuries. Several plant sources are identified for investigation in the context of this study. Chemical, botanical and historical aspects of these plants are described along with notes on their cultivation and nomenclature. The necessary thickeners and other additives that may be required for the production of a stable ink formulation are also discussed. The establishment of the Cat Hill Ink Garden is described as well as a discussion of other sources of raw material supply. Methods of aqueous extraction, lake production, comparative light fastness and spectral reflectance testing are all described and test results are provided in appendix form. The environmental, economic and health and safety aspects of the new inks is contrasted with the commercial oil-based product as well as a brief discussion of their potential for commercial development. Printed examples by the author and several of his students form the final part of the study and demonstrate the use of both CMYK and other non-primary ink formulations

    Tenure and Output

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    A key tenet of the theory of human capital is that investment in skills results in higher productivity. The previous literature has estimated the degree of investment in human capital for individuals by looking at individual wage growth as a proxy for productivity growth. In this paper, we have both wage and personal productivity data, and thus are able to measure of the increase in workers' output with tenure. The data is from an autoglass company. Most of production occurs at the individual level so measures of output are clear. We find a very steep learning curve in the year on the job: output is 53 percent higher after one year than it is initially when hired. These output gains with tenure are not reflected in equal percentage pay gains: pay profiles are much flatter than output profiles in the first year and a half on the job. For these data, using wage profiles significantly underestimates the amount of investment compared to the gains evident in output-tenure profiles. The pattern of productivity rising more rapidly than pay reverses after two years of tenure. Worker selection is also important. Workers who stay longer have higher output levels and faster early learning.

    Determining the parameters in a social welfare function using stated preference data: an application to health

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    One way in which economists might determine how best to balance the competing objectives of efficiency and equity is to specify a social welfare function (SWF). This paper looks at how the stated preferences of a sample of the general public can be used to estimate the shape of the SWF in the domain of health benefits. The results suggest that it is possible to determine the parameters in a social welfare function from stated preference data, but show that people are sensitive to what inequalities exist and to the groups across which those inequalities exist

    The inter-relation between policy and practice for transitions from hospital to home: An ethnographic case study in England’s National Health Service

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    © 2014 Shaw et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.No abstract available (poster presentation)

    Exact and Asymptotic Weighted Logrank Tests for Interval Censored Data: The interval R Package

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    For right-censored data perhaps the most commonly used tests are weighted logrank tests, such as the logrank and Wilcoxon-type tests. In this paper we review several generalizations of those weighted logrank tests to interval-censored data and present an R package, interval, to implement many of them. The interval package depends on the perm package, also presented here, which performs exact and asymptotic linear permutation tests. The perm package performs many of the tests included in the already available coin package, and provides an independent validation of coin. We review analysis methods for interval-censored data, and we describe and show how to use the interval and perm packages.
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