Classification, management, and tracking of abnormal Papanicolaou smears

A system of classifying, managing, and tracking abnormal Papanicolaou (Pap) smears was used at a California university where 3,289 patients were tested. Classification was based on use of the latest cytopathological techniques for identifying characteristics associated with dysplasia and human papilloma virus (HPV). The follow-up success rate was determined for 6-month repeat Pap smears, colposcopy patient contact, and biopsy results. Pathology report correlations were determined for the noncolposcopy group by using repeat Pap smear results. Biopsy results were correlated with Pap smear readings for accuracy and yielded significant statistical information for the program.     

Interdisciplinary research at the Urban–Rural interface: The West ga project

As human populations increase, ecological and social issues become inextricably linked to a greater degree. Solutions to complex social–ecological problems can only be derived through the use of integrated research that can account for the interplay of many factors across traditional discipline lines. We are using such an integrated research to clarify relationships among socioeconomic drivers, ecological effects, and social and policy feedbacks associated with urban development of forested landscapes. Our approach is goal oriented and interdisciplinary in nature and involves a team composed of ecologists, anthropologists, and economists who exchange ideas and information across disciplinary lines. The team and approach has evolved through many of the barriers to interdisciplinary research that have been identified by other authors. Our goal is to develop a predictive capability in order to anticipate ecological and social implications of urban development on natural resources in the southeastern United States. Our integrated model and subsequent papers in this special issue are presented.     

Cyclic Evaluation of Transitivity of Reciprocal Relations

A general framework for studying the transitivity of reciprocal relations is presented. The key feature is the cyclic evaluation of transitivity: triangles (i.e. any three points) are visited in a cyclic manner. An upper bound function acting upon the ordered weights encountered provides an upper bound for the ‘sum minus 1’ of these weights. Commutative quasi-copulas allow to translate a general definition of fuzzy transitivity (when applied to reciprocal relations) elegantly into the framework of cycle-transitivity. Similarly, a general notion of stochastic transitivity corresponds to a particular class of upper bound functions. Ample attention is given to self-dual upper bound functions.     

A Small-Sample Estimator for the Sample-Selection Model

A semiparametric estimator for evaluating the parameters of data generated under a sample selection process is developed. This estimator is based on the generalized maximum entropy estimator and performs well for small and ill-posed samples. Theoretical and sampling comparisons with parametric and semiparametric estimators are given. This method and standard ones are applied to three small-sample empirical applications of the wage-participation model for female teenage heads of households, immigrants, and Native Americans.     

Trends in inequality in infant mortality in the north of England, 1921–1973, and their association with urban and social structure

Summary.  The paper analyses a time series of infant mortality rates in the north of England from 1921 to the early 1970s at a spatial scale that is more disaggregated than in previous studies of infant mortality trends in this period. The paper describes regression methods to obtain mortality gradients over socioeconomic indicators from the censuses of 1931, 1951, 1961 and 1971 and to assess whether there is any evidence for widening spatial inequalities in infant mortality outcomes against a background of an overall reduction in the infant mortality rate. Changes in the degree of inequality are also formally assessed by inequality measures such as the Gini and Theil indices, for which sampling densities are obtained and significant changes assessed. The analysis concerns a relatively infrequent outcome (especially towards the end of the period that is considered) and a high proportion of districts with small populations, so necessitating the use of appropriate methods for deriving indices of inequality and for regression modelling.     

A comparison study of realtime fatality rates: severe acute respiratory syndrome in Hong Kong, Singapore, Taiwan, Toronto and Beijing, China

Summary.  In an outbreak of a completely new infectious disease like severe acute respiratory syndrome (SARS), estimation of the fatality rate over the course of the epidemic is of clinical and epidemiological importance. In contrast with the constant case fatality rate, a new measure, termed the 'realtime' fatality rate, is proposed for monitoring the new emerging epidemic at a population level. A competing risk model implemented via a counting process is used to estimate the realtime fatality rate in an epidemic of SARS. It can capture and reflect the time-varying nature of the fatality rate over the course of the outbreak in a timely and accurate manner. More importantly, it can provide information on the efficacy of a certain treatment and management policy for the disease. The method has been applied to the SARS data from the regions affected, namely Hong Kong, Singapore, Toronto, Taiwan and Beijing. The magnitudes and patterns of the estimated fatalities are virtually the same except in Beijing, which has a lower rate. It is speculated that the effect is linked to the different treatment protocols that were used. The standard estimate of the case fatality rate that was used by the World Health Organization has been shown to be unable to provide useful information to monitor the time-varying fatalities that are caused by the epidemic.