999 resultados para 1017
Resumo:
Evidence is accumulating that vitamin D may be protective against carcinogenesis, although exceptions have been observed for some digestive tract neoplasms. The aim of the present study was to explore the association between dietary vitamin D and related nutrients and the risk of oesophageal adenocarcinoma and its precursor conditions, Barrett's oesophagus and reflux oesophagitis. In an all-Ireland case-control study conducted between March 2002 and July 2005, 218 oesophageal adenocarcinoma patients, 212 Barrett's oesophagus patients, 208 reflux oesophagitis patients and 252 population-based controls completed a 101-item FFQ, and provided lifestyle and demographic information. Multiple logistic regression analysis was applied to examine the association between dietary intake and disease risk. Oesophageal adenocarcinoma risk was significantly greater for individuals with the highest compared with the lowest tertile of vitamin D intake (OR 1·99, 95 % CI 1·03, 3·86; P for trend = 0·02). The direct association could not be attributed to a particular vitamin D food source. Vitamin D intake was unrelated to Barrett's oesophagus and reflux oesophagitis risk. No significant associations were observed for Ca or dairy intake and oesophageal adenocarcinoma, Barrett's oesophagus or reflux oesophagitis development. High vitamin D intake may increase oesophageal adenocarcinoma risk but is not related to reflux oesophagitis and Barrett's oesophagus. Ca and dairy product intake did not influence the development of these oesophageal lesions. These findings suggest that there may be population subgroups at an increased risk of oesophageal adenocarcinoma if advice to improve vitamin D intake from foods is implemented. Limited work has been conducted in this area, and further research is required.
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The frequency of bad harvests and price elasticity of demand are measured using new data on English grain yields 1268–1480 and 1750–1850 and a revised price series. The analysis shows that major harvest shortfalls were a significant component of most historical subsistence crises, as back-to-back shortfalls were of the worst famines. Although serious harvest shortfalls long remained an unavoidable fact of economic life, by c.1800 yields had become less variable and prices less harvest sensitive. By the eve of the Industrial Revolution, England had become effectively famine-free.
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This article addresses the problem of divine foreknowledge and human freedom by developing a modi?ed version of Boethius’ solution to the problem–one that is meant to cohere with a dynamic theory of time and a conception of God as temporal. I begin the article by discussing the traditional Boethian solution, and a defence of it due to Kretzmann and Stump. After canvassing a few of the objections to this view, I then go on to o?er my own modi?ed Boethian solution, according to which temporal reality is fundamentally dynamic, but truth is not. My claim is that there are eternally existing, tenseless propositions, with determinate truth values, but that these are made true by events that come into existence, and are not themselves eternal.
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This article concerns the legal issues that surround the prohibition of doping in sport. The current policy on the use of performance enhancing drugs (PEDs) in sport is underpinned by both a paternalistic desire to protect athletes’ health and the long-term integrity or ‘spirit’ of sport. The policy is put into administrative effect globally by the World Anti-Doping Agency (WADA), which provides the regulatory and legal framework through which the vast majority of international sports federations harmonise their anti-doping programmes. On outlining briefly both the broad administrative structures of international sport’s various anti-doping mechanisms, and specific legal issues that arise in disciplinary hearings involving athletes accused of doping, this article questions the sustainability of the current ‘zero tolerance’ approach, arguing, by way of analogy to the wider societal debate on the criminalisation of drugs, and as informed by Sunstein and Thaler’s theory of libertarian paternalism, that current policy on anti-doping has failed. Moreover, rather than the extant moral and punitive panic regarding doping in sport, this article, drawing respectively on Seddon’s and Simon’s work on the history of drugs and crime control mentality, contends that, as an alternative, harm reductionist measures should be promoted, including consideration of the medically supervised use of certain PEDs.
Resumo:
In the UK vitamin B-12, deficiency occurs in approximately 20% of adults aged >65 years. This incidence is significantly higher than that among the general population. The reported incidence invariably depends on the criteria of deficiency used, and in fact estimates rise to 24% and 46% among free-living and institutionalised elderly respectively when methylmalonic acid is used as a marker of vitamin B-12 status. The incidence of, and the criteria for diagnosis of, deficiency have drawn much attention recently in the wake of the implementation of folic acid fortification of flour in the USA. This fortification strategy has proved to be extremely successful in increasing folic acid intakes pre-conceptually and thereby reducing the incidence of neural-tube defects among babies born in the USA since 1998. However, in successfully delivering additional folic acid to pregnant women fortification also increases the consumption of folic acid of everyone who consumes products containing flour, including the elderly. It is argued that consuming additional folic acid (as 'synthetic' pteroylglutamic acid) from fortified foods increases the risk of 'masking' megaloblastic anaemia caused by vitamin B-12 deficiency. Thus, a number of issues arise for discussion. Are clinicians forced to rely on megaloblastic anaemia as the only sign of possible vitamin B-12 deficiency? Is serum vitamin B-12 alone adequate to confirm vitamin B-12 deficiency or should other diagnostic markers be used routinely in clinical practice? Is the level of intake of folic acid among the elderly (post-fortification) likely to be so high as to cure or 'mask' the anaemia associated with vitamin B-12 deficiency?.
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A moral compromise is a compromise on moral matters; it is agreement in the face of moral disagreement but where there is agreement on the importance of consensus – namely that it secures a morally desirable outcome. It is distinguishable from other forms of agreement, and an important distinction between moral compromise with public agreement and moral compromise with public disagreement is also made. Circumstances in which the former might be permissible are outlined, and the sense in which it is allowed all things considered to agree is made clear. The relevant discussions of Dan Brock and Mary Warnock on the role of the philosopher to public policy are critically reviewed. Finally, a brief list is offered of the considerations relevant to an estimation of whether and, if so, when such compromise is allowed.
Resumo:
OBJECTIVE: To review the epidemiological evidence for vegetarian diets, low-meat dietary patterns and their association with health status in adults. DESIGN: Published literature review focusing primarily on prospective studies and meta-analyses examining the association between vegetarian diets and health outcomes. RESULTS: Both vegetarian diets and prudent diets allowing small amounts of red meat are associated with reduced risk of diseases, particularly CHD and type 2 diabetes. There is limited evidence of an association between vegetarian diets and cancer prevention. Evidence linking red meat intake, particularly processed meat, and increased risk of CHD, cancer and type 2 diabetes is convincing and provides indirect support for consumption of a plant-based diet. CONCLUSIONS: The health benefits of vegetarian diets are not unique. Prudent plant-based dietary patterns which also allow small intakes of red meat, fish and dairy products have demonstrated significant improvements in health status as well. At this time an optimal dietary intake for health status is unknown. Plant-based diets contain a host of food and nutrients known to have independent health benefits. While vegetarian diets have not shown any adverse effects on health, restrictive and monotonous vegetarian diets may result in nutrient deficiencies with deleterious effects on health. For this reason, appropriate advice is important to ensure a vegetarian diet is nutritionally adequate especially for vulnerable groups.
Resumo:
"There is, indeed, little doubt,” the formidable scholar James Orchard Halliwell-Phillipps confidently explained to the Victorian readers of his Outlines of the Life of Shakespeare, “that the Birth-place did not become one of the incentives for pilgrimage until public attention had been specially directed to it at the time of the Jubilee.” That's broadly true. The earliest reference to the three-gabled, half-timbered house (two houses, originally) on Henley Street in Stratford-upon-Avon as the birthplace of William Shakespeare dates only from the late 1750s, when it was so named in Samuel Winter's town map. During the Stratford Jubilee, which David Garrick organized in 1769, the “small old house,” as the actor's first biographer called it, was fully recognized and promoted as the place where Shakespeare was born. Even so, Halliwell-Phillipps's observation conceals more than it reveals, because there is also little doubt that the dwelling that tradition calls Shakespeare's birthplace did not suddenly acquire that status during the first week of September 1769. The process by which the unremarkable piece of real estate that John Shakespeare purchased sometime in the late sixteenth century was transformed into what Barbara Hodgdon has rightly called the “controlling ideological center” of Shakespeare biography was long, slow, and far from inevitable. That process is the subject of this essay.
Resumo:
A new approach to spectroscopy of laser induced proton beams using radiochromic film (RCF) is presented. This approach allows primary standards of absorbed dose-to-water as used in radiotherapy to be transferred to the calibration of GafChromic HD-810 and EBT in a 29 MeV proton beam from the Birmingham cyclotron. These films were then irradiated in a common stack configuration using the TARANIS Nd:Glass multi-terawatt laser at Queens University Belfast, which can accelerate protons to 10-12 MeV, and a depth-dose curve was measured from a collimated beam. Previous work characterizing the relative effectiveness (RE) of GafChromic film as a function of energy was implemented into Monte Carlo depth-dose curves using FLUKA. A Bragg peak (BP) "library" for proton energies 0-15 MeV was generated, both with and without the RE function. These depth-response curves were iteratively summed in a FORTRAN routine to solve for the measured RCF depth-dose using a simple direct search algorithm. By comparing resultant spectra with both BP libraries, it was found that the effect of including the RE function accounted for an increase in the total number of protons by about 50%. To account for the energy loss due to a 20 mu m aluminum filter in front of the film stack, FLUKA was used to create a matrix containing the energy loss transformations for each individual energy bin. Multiplication by the pseudo-inverse of this matrix resulted in "up-shifting" protons to higher energies. Applying this correction to two laser shots gave further increases in the total number of protons, N of 31% and 56%. Failure to consider the relative response of RCF to lower proton energies and neglecting energy losses in a stack filter foil can potentially lead to significant underestimates of the total number of protons in RCF spectroscopy of the low energy protons produced by laser ablation of thin targets.