bluuebunny/crossref_metadata_2025_split huggingface dataset:
Curious phenomena in Bayesian adjustment for exposure misclassification
Authors: Gustafson Paul , Greenland Sander 
Published: October 2005

AbstractMany epidemiologic investigations involve some discussion of exposure misclassification, but rarely is there an attempt to adjust for misclassification formally in the statistical analysis. Rather, investigators tend to rely on intuition to comment qualitatively on how misclassification might impact their findings. We point out several ways in which intuition might fail, in the context of unmatched case–control analysis with non‐differential exposure misclassification. Particularly, we focus on how intuition can conflict with the results of a Bayesian analysis that accounts for the various uncertainties at hand. First, the Bayesian adjustment for misclassification can weaken the evidence about the direction of an exposure–disease association. Second, admitting uncertainty about the misclassification parameters can lead to narrower interval estimates concerning the association. We focus on the simple setting of unmatched case–control analysis with binary exposure and without adjustment for confounders, though much of our discussion should be relevant more generally. Copyright © 2005 John Wiley & Sons, Ltd.
A multi‐state model for joint modelling of terminal and non‐terminal events with application to Whitehall II
Authors: Siannis F. , Farewell V. T. , Head J. 
Published: October 2005

AbstractSerious coronary heart disease (CHD) is a primary outcome in the Whitehall II study, a large epidemiological study of British civil servants. Both fatal (F) and non‐fatal (NF) CHD events are of interest and while essentially complete information is available on F events, the observation of NF events is subject to potentially informative censoring. A multi‐state model with an unobserved state is introduced for the joint modelling of F and NF events. Two model‐based assumptions ensure identifiability of the model and a parameter is introduced to allow sensitivity analyses concerning the assumption linked to informative censoring. Weibull transition rates, which include dependence on explanatory variables, are used in the analysis of Whitehall II data with a particular focus on the relationship between civil service grade and CHD events. Copyright © 2005 John Wiley & Sons, Ltd.
Causal conclusions are most sensitive to unobserved binary covariates
Authors: Wang Liansheng , Krieger Abba M. 
Published: October 2005

AbstractThere is a rich literature that considers whether an observed relation between treatment and response is due to an unobserved covariate. In order to quantify this unmeasured bias, an assumption is made about the distribution of this unobserved covariate; typically that it is either binary or at least confined to the unit interval. In this paper, this assumption is relaxed in the context of matched pairs with binary treatment and response. One might think that a long‐tailed unobserved covariate could do more damage. Remarkably that is not the case: the most harm is done by a binary covariate, so the case commonly considered in the literature is most conservative. This has two practical consequences: (i) it is always safe to assume that an unobserved covariate is binary, if one is content to make a conservative statement; (ii) when another assumption seems more appropriate, say normal covariate, there will be less sensitivity than with a binary covariate. This assumption implies that it is possible that a relation between treatment and response that is sensitive to unmeasured bias (if the unobserved covariate is dichotomous), ceases to be sensitive if the unobserved covariate is normally distributed. These ideas are illustrated by three examples. It is important to note that the claim in this paper applies to our specific setting of matched pairs with binary treatment and response. Whether the same conclusion holds in other settings is an open question. Copyright © 2005 John Wiley & Sons, Ltd.
Using the ROC curve for gauging treatment effect in clinical trials
Authors: Brumback Lyndia C. , Pepe Margaret S. , Alonzo Todd A. 
Published: October 2005

AbstractNon‐parametric procedures such as the Wilcoxon rank‐sum test, or equivalently the Mann–Whitney test, are often used to analyse data from clinical trials. These procedures enable testing for treatment effect, but traditionally do not account for covariates. We adapt recently developed methods for receiver operating characteristic (ROC) curve regression analysis to extend the Mann–Whitney test to accommodate covariate adjustment and evaluation of effect modification. Our approach naturally extends use of the Mann–Whitney statistic in a fashion that is analogous to how linear models extend thet‐test. We illustrate the methodology with data from clinical trials of a therapy for Cystic Fibrosis. Copyright © 2005 John Wiley & Sons, Ltd.
A powerful method of combining measures of association and Hardy–Weinberg disequilibrium for fine‐mapping in case‐control studies
Authors: Song Kijoung , Elston Robert C. 
Published: October 2005

AbstractWe present a new method for fine‐mapping a disease susceptibility locus using a case‐control design. The new method, termed the ‘weighted average (WA) statistic’, averages the Cochran–Armitage (CA) trend test statistic and the difference between the Hardy Weinberg disequilibrium test statistics (the HWD trend) for cases and controls. The main features of the WA statistic are that it mitigates against the weaknesses, and maintains the strong points, of both the CA trend test and the HWD trend test. To allow for the extra variance induced by population structure and cryptic relatedness, the WA statistic can be adjusted for variance inflation. Based on the results of a simulation study, when there is no population structure the WA test statistic shows good performance under a variety of genetic disease models. When there is population structure, the adjusted WA statistic maintains the correct probability of type I error. Under all genetic disease models investigated, the adjusted WA statistic has better power than the adjusted CA trend test, the HWD trend test or the product of the adjusted CA trend test and the HWD trend test statistics. Copyright © 2005 John Wiley & Sons, Ltd.
Effect measures in non‐parametric regression with interactions between continuous exposures
Authors: Cadarso‐Suárez Carmen , Roca‐Pardiñas Javier , Figueiras Adolfo 
Published: October 2005

AbstractIn many biomedical studies, interest is often attached to calculating effect measures in the presence of interactions between two continuous exposures. Traditional approaches based on parametric regression are limited by the degree of arbitrariness involved in transforming these exposures into categorical variables or imposing a parametric form on the regression function. In this paper, we present: (a) a flexible non‐parametric method for estimating effect measures through generalized additive models including interactions; and (b) bootstrap techniques for (i) testing the significance of interaction terms, and (ii) constructing confidence intervals for effect measures. The validity of our methodology is supported by simulations, and illustrated using data from a study of possible risk factors for post‐operative infection. This application revealed a hitherto unreported effect: for patients with high plasma glucose levels, increased risk is associated, not only with low, but also with high percentages of lymphocytes. Copyright © 2005 John Wiley & Sons, Ltd.
Diagnosis using predictive probabilities without cut‐offs
Authors: Choi Young‐Ku , Johnson Wesley O. , Thurmond Mark C. 
Published: October 2005

AbstractStandard diagnostic test procedures involve dichotomization of serologic test results. The critical value or cut‐off is determined to optimize a trade off between sensitivity and specificity of the resulting test. When sampled units from a population are tested, they are allocated as either infected or not according to the test outcome. Units with values high above the cut‐off are treated the same as units with values just barely above the cut‐off, and similarly for values below the cut‐off. There is an inherent information loss in dichotomization. We thus develop a diagnostic screening method based on data that are not dichotomized within the Bayesian paradigm. Our method determines the predictive probability of infection for each individual in a sample based on having observed a specific serologic test result and provides inferences about the prevalence of infection in the population sampled. Our fully Bayesian method is briefly compared with a previously developed frequentist method. We illustrate the methodology with serologic data that have been previously analysed in the veterinary literature, and also discuss applications to screening for disease in humans. The method applies more generally to a variation of the classic parametric 2‐population discriminant analysis problem. Here, in addition to training data, additional units are sampled and the goal is to determine their population status, and the prevalence(s) of the subpopulation(s) from which they were sampled. Copyright © 2005 John Wiley & Sons, Ltd.
Improving ecological inference using individual‐level data
Authors: Jackson Christopher , Best Nicky , Richardson Sylvia 
Published: October 2005

AbstractIn typical small‐area studies of health and environment we wish to make inference on the relationship between individual‐level quantities using aggregate, or ecological, data. Such ecological inference is often subject to bias and imprecision, due to the lack of individual‐level information in the data. Conversely, individual‐level survey data often have insufficient power to study small‐area variations in health. Such problems can be reduced by supplementing the aggregate‐level data with small samples of data from individuals within the areas, which directly link exposures and outcomes. We outline a hierarchical model framework for estimating individual‐level associations using a combination of aggregate and individual data. We perform a comprehensive simulation study, under a variety of realistic conditions, to determine when aggregate data are sufficient for accurate inference, and when we also require individual‐level information. Finally, we illustrate the methods in a case study investigating the relationship between limiting long‐term illness, ethnicity and income in London. Copyright © 2005 John Wiley & Sons, Ltd.
Anchors of the community: Community schools in Chicago
Authors: Swanson Elizabeth F. 
Published: October 2005

AbstractChicago Public Schools, in partnership with the greater Chicago community, is implementing the largest‐scale community school initiative in the nation. By bringing together public, private, and nonprofit entities, community schools in Chicago provide quality out‐of‐school‐time activities and services that strive to improve the education, health, and wellness of students, families, and the community.
UV‐B‐induced plant stress as a possible cause of ten‐year hare cycles
Authors: Selås Vidar 
Published: October 2005

AbstractPredation has been assumed to be a necessary factor in the ten‐year population cycle of the snowshoe hare (Lepus americanus) and Canadian lynx (Lynx canadensis). The UV‐B‐induced plant stress hypothesis, in contrast, predicts that hare performance, especially reproduction, is negatively related to sunspot numbers, because production of UV‐B‐protective phenolics in food plants in periods of low sunspot activity, when the ozone layer is thin, increases the availability of amino acids and reduces the amount of phenolics that protect against herbivores. In accordance with the UV‐B‐induced plant stress hypothesis, and despite the absence of predators that have been assumed to be necessary for hare cycles, mountain hare (Lepus timidus) populations in Norway fluctuate in close synchrony with snowshoe hare populations in Alberta and the Yukon, Canada. When adjusting for the phase of the hare cycle, the natality of snowshoe hare in Alberta 1962–1976 was negatively related to sunspot numbers with a time lag of two years. It is concluded that delayed responses to UV‐B‐induced changes in plant chemistry during the sunspot cycle is a possible cause of ten‐year cycles of hares and other herbivores, for example grouse and forest moths.
A Comparison of late Quaternary Forest Changes in New Caledonia and Northeastern Australia
Authors: Stevenson Janelle , Hope Geoffrey 
Published: October 2005

AbstractA pollen record from Lake Xere Wapo, southeast New Caledonia, is the longest continuous terrestrial record to be recovered from the tropical southwest Pacific and reveals a series of millennial scale changes in vegetation over the last ∼130,000 yr. A comparison of the Lake Xere Wapo record with the key northeast Australian record of Lynch's Crater reveals regional patterns of change. From ∼120,000 to ∼50,000 yr ago the vegetation around Lake Xere Wapo alternated between rainforest and maquis with fire an important disturbance factor. In the last 50,000 yr fire is almost absent from the record and the vegetation assumes a character unprecedented in the preceding 100,000 yr, dominated by Dacrydium and Podocarpus pollen. The most compelling aspect of the comparison with Lynch's Crater is that the much-discussed Araucaria decline at around 45,000 yr ago in northern Queensland is matched by a similar decline in the Lake Xere Wapo record.
If You Have No Misgivings: Churchill's Nobel Prize in Literature
Authors: ALLÉN STURE 
Published: October 2005

In 1953, Winston Churchill was awarded the Nobel Prize in Literature. Half a year later, I attended a course in English at a British university. We were a group of students from various countries, and we met for social evenings once a week. There were discussions and mutual entertainment as well as just getting together. On one of these occasions, I asked a question relating to the literary aspect of the course: ‘What was the reaction in this country when Winston Churchill got the Nobel Prize in Literature?’ There was complete silence. The main teacher was clearly embarrassed and looked at the other teachers, but not a word was uttered. Finally, he turned to me and said: ‘There was evidently no reaction.’ He looked around once more and added: ‘I think they were glad the old chap got something.’ The man referred to as ‘the old chap’ was about 80 years old at the time, a legend in his own lifetime, the receiver of heaps of distinctions including literary prizes.Everything that has to do with the Nobel Prize – nominations, reports, discussions – is subject to secrecy for 50 years. This is a blessing for us who are in charge of the Prize. The other side of the coin is that, as far as Churchill is concerned, I am now in a position to account for things that have been hidden so far. Let us see what the archives of the Academy can tell us, bearing in mind that one of the interesting aspects of the Prize is its function in cultural communication.
The rise and fall of dietetics and of nutrition science, 4000 BCE–2000 CE
Authors: Cannon Geoffrey 
Published: October 2005

AbstractObjectiveTo outline the history of dietetics since its beginnings in recorded history, and of nutrition science in its first phase beginning in the mid-nineteenth century and then its second phase in the second half of the twentieth century.MethodThree narrative overviews: of dietetics from its beginnings until after the end of the mediaeval and then Renaissance periods in Europe; of nutrition science in its first phase from its beginnings in the mid-nineteenth century until the middle of the twentieth century, with reasons for its rise; and of nutrition science in its second phase in the second half of the twentieth century, with reasons for its decline.ConclusionsIn its third phase in the twenty-first century, the new nutrition science should regain much of the vision and scope of its preceding disciplines.
Integrating nutrition with ecology: balancing the health of humans and biosphere
Authors: McMichael Anthony J 
Published: October 2005

AbstractObjectiveTo show that current rates of global population growth, production and consumption of food, and use of living and physical resources, are evidently not sustainable. To consider ways in which nutrition and allied sciences can respond to this great challenge of the twenty-first century.MethodPast, current and future projected trends in production and consumption patterns are examined. These show that overall present and projected patterns cannot be sustained; and also show increasing unacceptable inequity between and within rich and poor regions and countries.DiscussionNutrition science classically focuses on nutrients in relation to human physiology, metabolism, growth, health and disease. The social and environmental conditions of the modern, interconnected, market-oriented world, and the consequences for food production and consumption, are extending the research and policy agenda with which nutrition science must now urgently engage. Historically, much attention has been paid to eliminating nutritional deficiency states, and this remains an important task. In modern urban populations ‘malnutrition’ encompasses new forms of dietary imbalance, especially excesses of certain nutrients. These contribute to various non-communicable diseases and, particularly, to overweight/obesity and its attendant metabolic derangements and disease risks. As a mass phenomenon the current surge in obesity has no historical precedent. The escalating impact of humankind on the natural environment, with its ramifications for present and future food production, is also unprecedented.ConclusionThe essential challenge for nutrition science is to develop new understanding and strategies to enable a balance between promoting, equitably, the health of humans while sustaining the long-term health of the biosphere. Extension of nutrition science and food policy to meet those goals will be aided by understanding better how dietary conditions shaped the biological evolution of humankind. The fundamental long-term task is to integrate human health with the health of the biosphere.
Feeding people is easy: but we have to re-think the world from first principles
Authors: Tudge Colin 
Published: October 2005

AbstractObjectiveAgriculture designed to make best use of landscape and to be maximally sustainable would also provide food of the highest nutritional and gastronomic standards, and would inevitably employ a great many people. Thus it would solve the world's food problems, and its principal social problem, at a stroke. But agriculture in practice is designed for a quite different purpose – to generate wealth, in the cause of ‘economic growth’. The pressing need is not for more science and technology, but to recognise the true cause of the problems and to re-think priorities.ConclusionWe could all be well fed. Indeed, everyone in the world who is ever likely to be born could be fed to the highest standards of gastronomy as well as of nutrition until humanity itself comes to an end. We already have most of the necessary technique – perhaps all that is needed. We could always do with more excellent science but we need not depend, as we are often told from on high, on the next technological fix. The methods that can provide excellent food would also create a beautiful environment, with plenty of scope for other creatures, and agreeable and stable agrarian economies with satisfying jobs for all.In reality, in absolute contrast, we have created a world in which almost a billion are chronically undernourished; another billion are horribly overnourished, so that obesity and diabetes are epidemic, and rising; a billion live on less than two dollars a day; and a billion live in urban slums – a figure set to increase and probably at least to double over the next half century; while other species are disappearing so fast that biologists speak of mass extinction.
Defining and addressing the nutritional needs of populations
Authors: Uauy Ricardo 
Published: October 2005

AbstractObjectiveTo examine the present methods used to define nutritional needs, and to analyse the intrinsic limitations of the reductionist chemical, biological and medical approaches to assess requirements. To establish the necessity to incorporate the complexities emerging from a broader understanding of the biological sciences as well as to include environmental and social dimensions in addressing nutritional needs.MethodExamples of the limitations of current approaches and the implications of these in defining potential solutions and policy options to address present nutritional problems are presented and discussed.ConclusionThe chemical and biological sciences have provided a strong base for nutrition and have been essential in establishing nutrition as a science with public health relevance. However, these approaches are clearly insufficient to address the main challenges that confront nutrition science now in the twenty-first century. There is a pressing need to include the social, economic and human rights aspects in order to define future policies that will secure the right to safe and nutritious food for all.
Using research on the obesity pandemic as a guide to a unified vision of nutrition
Authors: Popkin Barry M 
Published: October 2005

AbstractObjectiveTo focus on factors that play a major role in our rapid, global nutritional changes.DesignA range of studies are summarised: these show how an understanding of social, economic and technological change at the global, national and community levels affects diet, activity, and body composition patterns and trends. These studies are used to demonstrate the value of the key global, national, community, household and individual factors that should define the field of nutrition.SettingThe focus is global.ResultLarge shifts have occurred in diet and in physical activity patterns – particularly in the last one or two decades of the twentieth century. These changes are reflected in nutritional outcomes such as changes in average stature, body composition and morbidity. Understanding the rapidity of these changes and the underlying factors at the global, national and community levels is critical for creating a science of nutrition that can prevent disease and sustain the health and integrity of humans.ConclusionThe vision of the nutrition field is one where scholars who work on many levels will intersect; equal weight in the nutrition profession will be provided to all dimensions as they are welcomed into the field of nutrition – particularly those that will directly or indirectly affect dietary patterns, physical activity patterns, and energetics. This vision of the nutrition field is one where scholars from a range of disciplines and perspectives meet to work together with the goal being a focus on improving nutritional status and the human condition.
Wholesome nutrition: a suitable dietfor the new nutrition science project
Authors: Leitzmann Claus 
Published: October 2005

AbstractObjectiveTo show that the practice of wholesome nutrition meets the demands of the concept of the new nutrition science, at present and in the future.MethodTo define ‘wholesome nutrition’, to describe its origin and to discuss its recommendations; and to cite practical examples showing that wholesome nutrition includes the dimensions and domains that are the basis of the concept of the new nutrition science.ConclusionThe recommendations of wholesome nutrition are an effective implementation of the concept of the new nutrition science.