Bayesian model selection for join point regression with application to age-adjusted cancer rates

Summary.  The method of Bayesian model selection for join point regression models is developed. Given a set of K +1 join point models M ₀,  M ₁, …,  M _K with 0, 1, …,  K join points respec-tively, the posterior distributions of the parameters and competing models M _k are computed by Markov chain Monte Carlo simulations. The Bayes information criterion BIC is used to select the model M _k with the smallest value of BIC as the best model. Another approach based on the Bayes factor selects the model M _k with the largest posterior probability as the best model when the prior distribution of M _k is discrete uniform. Both methods are applied to analyse the observed US cancer incidence rates for some selected cancer sites. The graphs of the join point models fitted to the data are produced by using the methods proposed and compared with the method of Kim and co-workers that is based on a series of permutation tests. The analyses show that the Bayes factor is sensitive to the prior specification of the variance σ ², and that the model which is selected by BIC fits the data as well as the model that is selected by the permutation test and has the advantage of producing the posterior distribution for the join points. The Bayesian join point model and model selection method that are presented here will be integrated in the National Cancer Institute's join point software ( http://www.srab.cancer.gov/joinpoint/ ) and will be available to the public.     

ADDITIVE MODELS WITH PREDICTORS SUBJECT TO MEASUREMENT ERROR

This paper develops a likelihood‐based method for fitting additive models in the presence of measurement error. It formulates the additive model using the linear mixed model representation of penalized splines. In the presence of a structural measurement error model, the resulting likelihood involves intractable integrals, and a Monte Carlo expectation maximization strategy is developed for obtaining estimates. The method's performance is illustrated with a simulation study.     

MORE INFORMATIVE TESTING FOR BIVARIATE SYMMETRY

In testing for bivariate symmetry against arbitrary alternatives the well‐known test developed by Bowker in 1948 is shown to be a score test, and to have useful components. These components are asymptotically independent and asymptotically have the standard normal distribution. Moreover they assess particular pairs of cells for symmetry. These components can also be used in a data analytic manner to complement a test for bivariate symmetry against ordered alternatives.     

A NEW SHORT EXACT GEOMETRIC CONFIDENCE INTERVAL

For discrete distributions, the standard method of producing a two‐sided confidence interval generates an interval that is exact but conservative. This paper proposes a new algorithm to produce a short exact geometric confidence interval with proven properties, and compares the new interval with the standard interval.     

Local model uncertainty and incomplete-data bias (with discussion)

Summary.  Problems of the analysis of data with incomplete observations are all too familiar in statistics. They are doubly difficult if we are also uncertain about the choice of model. We propose a general formulation for the discussion of such problems and develop approximations to the resulting bias of maximum likelihood estimates on the assumption that model departures are small. Loss of efficiency in parameter estimation due to incompleteness in the data has a dual interpretation: the increase in variance when an assumed model is correct; the bias in estimation when the model is incorrect. Examples include non-ignorable missing data, hidden confounders in observational studies and publication bias in meta-analysis. Doubling variances before calculating confidence intervals or test statistics is suggested as a crude way of addressing the possibility of undetectably small departures from the model. The problem of assessing the risk of lung cancer from passive smoking is used as a motivating example.     

Reports of Conferences, Institutes, and Seminars

Reports on the 2005 North Carolina Serials Conference, the twentieth anniversary conference of the North American Serials Interest Group, the 2005 Acquisitions Institute at Timberline Lodge, and a program on electronic archiving sponsored by the New England Chapter of the Association of College and Research Libraries.     

中国文化下的禀性匹配模型

东西方文化维度的不同决定了组织中激励的方式各有差异。研究具有中国文化特质的“关系”与“面子”,理解“自我概念”“角色完成”“领导者的责任”“长期目标”“和谐关系”“满足感与平等感”等具体概念的东西方差异,建立修改后的综合分析模型,该模型表明虽然禀性匹配对于西方文化背景下的工作激励过程很重要,但在中国的领导者与员工之间,“关系”和“面子”更为重要。     

A Demographic Model of Measles Epidemics

Liverpool, U.K., 1863--1900, has been used as a model to explore the interaction between measles epidemics and the population dynamics in an overcrowded community with inadequate nutrition using a non-linear model which allows the estimation of certain underlying demographic parameters. The results are consistent with a system that is driven by an oscillation in the transmission parameter that is compounded of an oscillation in autumn temperatures (at the resonant frequency of the system, 2.4 years) and, secondarily, by an oscillation in wheat prices (wavelength = 5.3 years, twice that of the epidemics).     

配合物ErI3.2CS（NH2）2.10H2O的制备及表征

本文根据０℃时碘化铒－硫脲（ＣＳ（ＮＨ２）２－水三元体系相平衡数据,确定了配合物ＥｒＩ３．２ＣＳ（ＮＨ２）２．１０Ｈ２Ｏ的制备方法,并对所得 进行化学分析、Ｘ－射线粉末衍射、红外光谱、差热分析,测定其密度,折光指数及轴性,确定配合物结构中的配位关系。     

De-standardization of Family-Life Trajectories of Young Adults: A Cross-National Comparison Using Sequence Analysis

We introduce a number of new methods based on sequence analysis to test hypotheses on the de-standardization of family-life trajectories in early adulthood, using Fertility and Family Survey data on 19 countries. Across cohorts, family-life trajectories of young adults have not become more turbulent. However, in most countries family-life trajectories of young adults have become less similar to one another and the variation in the types of family-trajectories has increased. Contrary to expectations, no clear differences in de-standardization were observed between countries characterized by a social-democratic welfare-state regime and countries characterized by either liberal or conservative welfare-state regimes.