bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unsupervised Classification of Chemical Compounds
Authors: Guttiérrez Toscano P. , Marriott F. H. C. 
Published: March 2003

SUMMARY
Clustering chemical compounds of similar structure is important in the pharmaceutical industry. One way of describing the structure is the chemical ‘fingerprint’. The fingerprint is a string of binary digits, and typical data sets consist of very large numbers of fingerprints; a suitable clustering procedure must take account of the properties of this method of coding, and must be able to handle large data sets. This paper describes the analysis of a set of fingerprint data. The analysis was based on an appropriate distance measure derived from the fingerprints, followed by metric scaling into a low-dimensional space. An approximation to metric scaling, suitable for very large data sets, was investigated. Cluster analysis using two programs, mclust and AutoClass-C, was carried out on the scaled data.
The Use of Resampling Methods to Simplify Regression Models in Medical Statistics
Authors: Sauerbrei Willi 
Published: March 2003

SUMMARY
The number of variables in a regression model is often too large and a more parsimonious model may be preferred. Selection strategies (e.g. all-subset selection with various penalties for model complexity, or stepwise procedures) are widely used, but there are few analytical results about their properties. The problems of replication stability, model complexity, selection bias and an over-optimistic estimate of the predictive value of a model are discussed together with several proposals based on resampling methods. The methods are applied to data from a case–control study on atopic dermatitis and a clinical trial to compare two chemotherapy regimes by using a logistic regression and a Cox model. A recent proposal to use shrinkage factors to reduce the bias of parameter estimates caused by model building is extended to parameterwise shrinkage factors and is discussed as a further possibility to illustrate problems of models which are too complex. The results from the resampling approaches favour greater simplicity of the final regression model.
Multitaper Testing of Spectral Lines and the Detection of the Solar Rotation Frequency and its Harmonics
Authors: Denison D. G. T. , Walden A. T. , Balogh A. , Forsyth R. J. 
Published: March 2003

SUMMARY
We develop statistical testing methodology for closely spaced spectral lines based on multitaper spectrum estimates and apply it to a time series of solar magnetic field magnitude data recorded by the Ulysses spacecraft. The test is formulated through complex-valued weighted least squares. Using this test in combination with the test for well-separated lines, we can accurately detect the solar equatorial rotation frequency of the sun, and its harmonics, from data recorded by Ulysses’s magnetometer at solar mid-latitudes; this is a potentially important result for solar physicists, since it has implications for the structure and dynamics of magnetic fields in the solar corona.
On the Use of Corrections for Overdispersion
Authors: Lindsey J. K. 
Published: March 2003

SUMMARY
In studying fluctuations in the size of a blackgrouse (Tetrao tetrix) population, an autoregressive model using climatic conditions appears to follow the change quite well. However, the deviance of the model is considerably larger than its number of degrees of freedom. A widely used statistical rule of thumb holds that overdispersion is present in such situations, but model selection based on a direct likelihood approach can produce opposing results. Two further examples, of binomial and of Poisson data, have models with deviances that are almost twice the degrees of freedom and yet various overdispersion models do not fit better than the standard model for independent data. This can arise because the rule of thumb only considers a point estimate of dispersion, without regard for any measure of its precision. A reasonable criterion for detecting overdispersion is that the deviance be at least twice the number of degrees of freedom, the familiar Akaike information criterion, but the actual presence of overdispersion should then be checked by some appropriate modelling procedure.
The Relationship Between Double-Exponential Families and Extended Quasi-Likelihood Families, with Application to Modelling Geissler’s Human Sex Ratio Data
Authors: Lee Y. , Nelder J. A. 
Published: March 2003

SUMMARY
The human sex ratio data, collected in Saxony in the 19th century by Geissler, are reanalysed by joint modelling of the mean and dispersion. Extended quasi-likelihood and the unnormalized double-exponential family are shown to lead to identical inference. The use of the unnormalized form is discussed. The relationship between multinomial and Poisson models is studied for overdispersed data.
A Multivariate Time Series Model for the Analysis and Prediction of Carbon Monoxide Atmospheric Concentrations
Authors: Tonellato Stefano F. 
Published: March 2003

SUMMARY
We use a Bayesian multivariate time series model for the analysis of the dynamics of carbon monoxide atmospheric concentrations. The data are observed at four sites. It is assumed that the logarithm of the observed process can be represented as the sum of unobservable components: a trend, a daily periodicity, a stationary autoregressive signal and an erratic term. Bayesian analysis is performed via Gibbs sampling. In particular, we consider the problem of joint temporal prediction when data are observed at a few sites and it is not possible to fit a complex space–time model. A retrospective analysis of the trend component is also given, which is important in that it explains the evolution of the variability in the observed process.
Functional and Dynamic Magnetic Resonance Imaging Using Vector Adaptive Weights Smoothing
Authors: Polzehl Jörg , Spokoiny Vladimir G. 
Published: March 2003

SUMMARY
We consider the problem of statistical inference for functional and dynamic magnetic resonance imaging (MRI). A new approach is proposed which extends the adaptive weights smoothing procedure of Polzehl and Spokoiny that was originally designed for image denoising. We demonstrate how the adaptive weights smoothing method can be applied to time series of images, which typically occur in functional and dynamic MRI. It is shown how signal detection in functional MRI and the analysis of dynamic MRI can benefit from spatially adaptive smoothing. The performance of the procedure is illustrated by using real and simulated data.
Application of Markov Chain Monte Carlo Methods to Projecting Cancer Incidence and Mortality
Authors: Bray Isabelle 
Published: March 2003

SUMMARYProjections based on incidence and mortality data collected by cancer registries are important for estimating current rates in the short term, and public health planning in the longer term. Classical approaches are dependent on questionable parametric assumptions. We implement a Bayesian age–period–cohort model, allowing the inclusion of prior belief concerning the smoothness of the parameters. The model is described by a directed acyclic graph. Computations are carried out by using Markov chain Monte Carlo methods (implemented in BUGS) in which the degree of smoothing is learnt from the data. Results and convergence diagnostics are discussed for an exemplary data set. We then compare the Bayesian projections with other methods in a range of situations to demonstrate its flexibility and robustness.
Nonparametric Measures of Association between a Spatial Point Process and a Random Set, with Geological Applications
Authors: Foxall Rob , Baddeley Adrian 
Published: March 2003

SUMMARYIn mining exploration it is often desired to predict the occurrence of ore deposits given other geological information, such as the locations of faults. More generally it is of interest to measure the spatial association between two spatial patterns observed in the same survey region. Berman developed parametric methods for conditional inference about a point process X given another spatial process Y. This paper proposes an alternative, nonparametric, approach using distance methods, analogous to the use of the summary functions F, G and J for univariate point patterns. Our methods apply to a bivariate spatial process (X, Y) consisting of a point process X and a random set Y. In particular we develop a bivariate analogue of the J-function of van Lieshout and Baddeley which shows promise as a summary statistic and turns out to be closely related to Berman's analysis. Properties of the bivariate J-function include a multiplicative identity under independent superposition, which has no analogue in the univariate case. Two geological examples are investigated.
Maximuma PosterioriEstimation of Image Boundaries by Dynamic Programming
Authors: Glasbey C. A. , Young M. J. 
Published: March 2003

SUMMARYWe seek a computationally fast method for solving a difficult image segmentation problem: the positioning of boundaries on medical scanner images to delineate tissues of interest. We formulate a Bayesian model for image boundaries such that the maximum a posterioriestimator is obtainable very efficiently by dynamic programming. The prior model for the boundary is a biased random walk and the likelihood is based on a border appearance model, with parameter values obtained from training images. The method is applied successfully to the segmentation of ultrasound images and X-ray computed tomographs of sheep, for application in sheep breeding programmes.
The Limiting Density of Unit Root Test Statistics: A Unifying Technique
Authors: Gonen Mithat , Puri Madan L. , Ruymgaart Frits H. , Van Zuijlen Martien C. A. 
Published: March 2003

In this note we introduce a simple principle to derive a constructive expression for the density of the limiting distribution, under the null hypothesis, of unit root statistics for an AR(1)‐process in a variety of situations. We consider the case of unknown mean and reconsider the well‐known situation where the mean is zero. For long‐range dependent errors we indicate how the principle might apply again. We also show that in principle the method also works for a near unit root case. Weak convergence and subsequent Karhunen‐Loeve expansion of the weak limit of the partial sum process of the errors plays an important role, along with the evaluation of a certain normal type integral with complex mean and variance. For independent and long range dependent errors this weak limit is ordinary and fractional Brownian motion respectively.AMS 1991 subject classification. Primary 62M10; secondary 62E20.
Schoolhouses, Jailhouses and the House of Being: The Tragedy of Philosophy’s Metaphors
Authors: Cohen Daniel H. 
Published: March 2003

As a rule, there is nothing in the words themselves to mark off metaphors from literal language. If a boundary could somehow be drawn, it would be in constant need of re‐adjustment as metaphors become entrenched, idiomatic, and finally literal, and literal phrases are put to figurative or hyperbolic, and then metaphorical uses. Further, there is no algorithmic recovery of the intended meaning of a metaphor from the meanings of its components, no function that takes literal meanings as its arguments and has metaphorical meaning as its output. That is, metaphors are syntactically invisible, pragmatically unstable, and semantically under‐determined. Their creation, use, and interpretation are almost impenetrable mysteries. As if to spite semantic theorists, they are also linguistic commonplaces, present in every kind of discourse.The discourse of philosophy is no exception to this rule, availing itself of the various stylistic, heuristic, and explanatory roles metaphors can play. Philosophy also produces metaphors of another sort, metaphors that differ in important ways from the metaphors of art and literature, as well as the metaphors of the natural and social sciences. These “grand“ metaphors are lasting monuments to the triumphs of philosophical discourse, even as they are also testimony to the failures of philosophical theorizing. This is because philosophy’s grand metaphors were never intended that way. They are better read as structural hypotheses that have become metaphors only after failing as literal truths. Ironically, it is precisely as metaphors that these images are integrated into our ways of thinking. In the end, thought itself is re‐structured, and these failures as descriptive truths succeed in becoming “constitutive truths” of a new reality.
The Foreignness of Germs: The Persistent Association of Immigrants and Disease in American Society
Authors: Markel Howard , Stern Alexandra Minna 
Published: March 2003

During the 20th century the united states witnessed sweeping social, political, and economic transformations as well as far‐reaching advancements in medical diagnosis and care. Despite the dramatic changes in demography, the meaning of citizenship, and the ability to treat and cure acute and chronic diseases, foreigners were consistently associated with germs and contagion. In this article we explore why, at critical junctures in American history, immigrants have been stigmatized as the etiology of a wide variety of physical and societal ills. Anti‐immigrant rhetoric and policy have often been framed by an explicitly medical language, one in which the line between perceived and actual threat is slippery and prone to hysteria and hyperbole.Our examination focuses on three periods of immigration history: (1) the late 19th century to the passage of the National Origins Act in 1924 when millions of newcomers arrived in the United States and increasingly stringent quotas were enacted; (2) an era of retrenchment and exclusion from 1924 to 1965 when far fewer immigrants entered yet their identification with disease and contamination remained intact; (3) and the period from 1965 to the present, when family reunification laws became the centerpiece of immigration policy and spawned the migration of millions of Asians and Latin Americans to this country.During the 20th century the United States witnessed social, political, and economic transformations as well as advancements in medical diagnosis and care. Despite changes in demography, the meaning of citizenship, and the ability to treat and cure acute and chronic diseases, foreigners were consistently associated with germs and contagion. This article explores why, at critical junctures in American history, immigrants have been stigmatized as the etiology of a variety of physical and societal ills. The article analyzes three periods from 1880 to the present and suggests that now, as germs progressively and, often, indiscriminately cross national, social, and economic boundaries through multiple vectors, the mistakes of the past must not be repeated. Protecting the public health in the current era of globalization requires an ecumenical, pragmatic, and historically informed approach to understanding the links between immigration and disease.
A Loss of Faith: The Sources of Reduced Political Legitimacy for the American Medical Profession
Authors: Schlesinger Mark 
Published: March 2003

Writing at the beginning of the 20thcentury, Shaw identified one of the significant contemporary transformations in industrial democracies. In part as the result of advances in science and technology, in part as a rejection of the monopolistic abuses of industrialization, and in part as a consequence of assiduous efforts by the professions themselves, this was a period in which the legitimacy and social authority of professionals increased dramatically (Brint 1994;Krause 1996;Larson 1977;Sandel 1996). Nowhere was this more evident than in medicine. Over several decades, medicine changed from an occupation with a mixed reputation and little political influence into one that would “dominate both policy and lay perceptions of health problems” (Freidson 1994, 31). In a number of countries, the professional authority and political influence of physicians also rose during this era (Coburn, Torrance, and Kaufert 1983;Krause 1996;Stone 1980), most dramatically in the United States (Starr 1982).The political legitimacy and policymaking influence of the medical profession have greatly declined in American society over the past 30 years. Despite speculation about the causes, there has been little empirical research assessing the different explanations. To address this gap, data collected in 1995 are used to compare attitudes of the American public and policy elites toward medical authority. Statistical analyses reveal that (1) elites are more hostile to professional authority than is the public; (2) the sources of declining legitimacy are different for the public than they are for policy elites; and (3) the perceptions that most threaten the legitimacy of the medical profession pertain to doubts about professional competence, physicians' perceived lack of altruism, and limited confidence in the profession's political influence. This article concludes with some speculations about the future of professional authority in American medicine.
The Meaning and Determinants of Skills Shortages
Authors: Green Francis , Machin Stephen , Wilkinson David 
Published: March 2003

In this paper we use establishment‐level data to examine what managers mean when they report having skills shortages. We find that the concept of a skills shortage is not always the same as a hard‐to‐fill vacancy despite the latter being used by many authors who have considered the economic consequences of skills shortages.It seems that, while employers appear not to have any problems for themselves in interpreting questions on ‘skills shortages’, we cannot rely on them being perceived in a uniform way by all employers. Indeed, many employers stress that, amongst both their existing workforce and job applicants, there appear to be important shortfalls in motivational and attitudinal skills, leading us to believe that social skills are an important part of the skills said to be in shortage.Our findings point to two main conclusions for future research. First, studies that investigate the causes and effects of ‘skill shortages’ need to pay greater attention to their definition and measurement. Secondly, in future research on establishments and their skill formation practices, further steps could be taken to gain clarification either directly or indirectly from respondents as to the experiences they choose to classify as a skills shortage.
Does a Real Albert Nolan Need Don Cupitt? A Response to Ronald Nicolson
Authors: Egan Anthony 
Published: March 2003

In this paper, in response to Nicolson’s claim that South African liberation theology is non‐realist – or at least is non‐realist in its language – I suggest that Albert Nolan’s important book God in South Africa is not based on such an “exotic” philosophical basis but is a reflection using the populist Marxism of the anti‐apartheid struggle of the 1980s. The clue here is Nolan’s use of the Colonialism of a Special Type thesis, an integral part of ANC and Communist Party discourse since the 1960s. Nolan himself has described his work as “historical materialist” in its philosophical language. Such a position seems far removed from non‐realism, although they certainly sound similar in Nolan’s God‐language.I then examine non‐realist theologian Don Cupitt’s model of “militant religious humanism” (from his Life‐Lines) and conclude that a non‐realist liberation or political theology along these lines suffers too much from a sense of relativism or absurdity for it to be of use to those who use liberation theology. From this I try to suggest how a non‐realist liberation theology might be developed. In the end, however, I conclude that though such a theology could be constructed, it would probably not be effective: liberation theology requires a real God who really sides with the poor.
On the Ethical Nature of Priesthood
Authors: Purcell Michael 
Published: March 2003

This article argues that ministerial priesthood, rather than being ontologically comprehended, should be ethically articulated. The ‘character’ of priesthood is to be ‘for‐the‐other.’ Following a thought of Emmanuel Levinas on the ‘liturgical orientation of work,’ we argue that(i) — Priesthood is essentially liturgical, in the sense of a movement out of oneself towards the other which never returns to the self. This movement is at one and the same time on orientation towards God, as divine other, and the other person. This ‘liturgical’ orientation of the self is seen and celebrated in the sacred liturgy of the Church with which the life and ministry of the priest is intimately associated. In this sense, the liturgy of the Church is not only an expression of what the Church is, but also, as an expression of the ethical subjectivity of the self which is ‘the‐Other‐in‐me,’ a celebration of who I am.(ii) — Priesthood is essentially eucharistic. In the commemoration of the passion, death and resurrection of Christ, the ethical and ecclesial structure of subjectivity, is recalled and realised in the words ‘for you (hyper hymon)’ and ‘for all (hyper pollon).’(iii) — Priesthood is self‐sacrificial. If living eucharistically is living ‘for you (hyper hymon)’ and ‘for all (hyper pollon),’ then this finds its extreme expression in the sacrifice of oneself for‐the‐other in suffering and death. This involves substitution which, as Levinas says, ‘is indispensable to the comprehension of subjectivity.’
John Finnis on Aquinas ‘The Philosopher’
Authors: Bradley Denis J. M. 
Published: March 2003

In the ten dense chapters of his new book, John Finnis examines and sometimes amends what he takes to be the key moral, legal, social and political doctrines of Thomas Aquinas. Finnis correctly stresses that neither ethics nor politics, in the Arstotelian tradition to which Aquinas belonged, are theoretical sciences. They are ‘practical’ or action‐guiding sciences. Since societal order originates in free choice, it is subject to moral norms. The latter are more firmly grounded by Aquinas than Aristotle because the former unlike the latter has an explicit and coherent account of universal or exceptionless moral principles.Finnis natural law ethics derives from a set of self‐evident precepts that focus practical reason on the pursuit and protection of basic human goods. Finnis expanding list of the latter now include marriage. Finnis equates – implausibly, in my view – attaining the ensemble of basic human goods (‘integral human fulfilment’) with Aquina's notion of beatitudo imperfecta or this‐worldly happiness.Throughout the book, Finnis' exegesis of Aquinas is slanted towards bolstering Finnis' own Thomist philosophical ethics. Accordingly, Thomistic historical scholarship, which carefully traced Aquinas' biblical and patristic sources and which locate Aquinas' theological ethics within the conditions of his own life and times, has little weight in Finnis' interpretation. Overall, Finnis shows little concern for the internal logic of the Summa theologiae and, consequently, he does not adequately clarify how Aquinas' own ethics, according to its proper principles, can be both integrally theological and rational without thereby becoming a philosophical ethics.