Multiple event times in the presence of informative censoring: modeling and analysis by copulas

Motivated by a breast cancer research program, this paper is concerned with the joint survivor function of multiple event times when their observations are subject to informative censoring caused by a terminating event. We formulate the correlation of the multiple event times together with the time to the terminating event by an Archimedean copula to account for the informative censoring. Adapting the widely used two-stage procedure under a copula model, we propose an easy-to-implement pseudo-likelihood based procedure for estimating the model parameters. The approach yields a new estimator for the marginal distribution of a single event time with semicompeting-risks data. We conduct both asymptotics and simulation studies to examine the proposed approach in consistency, efficiency, and robustness. Data from the breast cancer program are employed to illustrate this research.

     

EDITH WHARTON'S SICK ROLE

In this article, we conduct a textual analysis of Edith Wharton's 1911 novel, Ethan Frome . We offer three readings. The first presents Wharton's account of illness through a framework developed foru decades later by Talcott Parsons. Wharton's sick role was less medico-centric than Parsons; it emphasized the importance of class, gender and community in defining and legitimizing the sick role. Our second reading explores the socially constructed nature of roles in illness. The sick role as portrayed by Wharton is not the social fact later conceived by Parsons, but a social construct with no determinate reference beyond that which the local community is willing to grant it. Our third reading examines the social context, particularly the power relations, within which this story of illness has been constructed.     

‘I Just Don't Want to Get Picked on by Anybody’: Dynamics of Inclusion and Exclusion in a Newly Multi‐Ethnic Irish Primary School

Given the changing patterns of immigration in the Republic of Ireland in the past 10 years, this article considers how factors related to ethnic and gender identity mediate children's interaction with one another in a newly multi‐ethnic Irish primary school. Central to the analysis is the exercise of power between children and how the experience of inclusion and exclusion in peer relations is underpinned by concepts of sameness/difference that draw upon wider discourses of ethnic and gender identity. Recommendations in relation to classroom and school practice are made with reference to the need for teachers to take account of the complexity of children's social worlds and the dynamics of power and control that operate within it. Copyright © 2006 The Author(s).     

Marginal and association regression models for longitudinal binary data with drop‐outs: A likelihood‐based approach

Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances.     

Becoming American/Becoming New Yorkers: Immigrant Incorporation in a Majority Minority City1

Many observers have noted that immigrants to the United States are highly concentrated in the largest metropolitan areas of a relatively few states. Though immigrants diffused into many places that had previously seen relatively few immigrants during the 1990s, as of the 2000 census, 77 percent of the nation's 31.1 million foreign born residents still lived in six states — California, New York, Texas, Florida, New Jersey, and Illinois. According to the 2000 census, the two largest metropolitan areas, Los Angeles and New York, accounted for one third of all immigrants ( http://www.census.gov/Press‐Release/www/2002/demoprofiles.html ). While immigrants moved into many new areas during the 1990s, making the challenge of incorporating their children a national issue, their concentration in our largest cities remained pronounced.     

Successful collaboration between the nonprofit and public sectors

Public and private funding sources often require nonprofit organizations to provide evidence of partnership with a governmental entity before financing a project. However, the circumstances under which working partnerships between the nonprofit and public sectors are forged and sustained have not been fully studied. This article presents the findings of a case study of land trusts and local governments and identifies conditions that foster successful collaboration. Social factors such as experience on the part of key personnel in working with the opposite entity and genuine affection for each other are more important than economic benefits. This suggests that a nonprofit agency interested in creating a viable partnership to improve a project should give careful consideration to assigning staff.     

Consistent maximum likelihood estimation of a unimodal density using shape restrictions

It is well known that the unimodal maximum likelihood estimator of a density is consistent everywhere but at the mode. The authors review various ways to solve this problem and propose a new estimator that is concave over an interval containing the mode; this interval may be chosen by the user or through an algorithm. The authors show how to implement their solution and compare it to other approaches through simulations. They show that the new estimator is consistent everywhere and determine its rate of convergence in the Hellinger metric.