Joint analysis of longitudinal data and competing terminal events in the presence of dependent observation times with application to chronic kidney disease

In many prospective clinical and biomedical studies, longitudinal biomarkers are repeatedly measured as health indicators to evaluate disease progression when patients are followed up over a period of time. Patient visiting times can be referred to as informative observation times if they are assumed to carry information in addition to that of the longitudinal biomarker measures alone. Irregular visiting times may reflect compliance with physician instruction, disease progression and symptom severity. When the follow-up time may be stopped by competing terminal events, it is possible that patient observation times may correlate with the competing terminal events themselves, thus making the observation times difficult to assess. To explicitly account for the impact of competing terminal events and dependent observation times on the longitudinal data analysis in the context of such complex data, we propose a joint model using latent random effects to describe the association among them. A likelihood-based approach is derived for statistical inference. Extensive simulation studies reveal that the proposed approach performs well for practical situations, and an analysis of patients with chronic kidney disease in a cohort study is presented to illustrate the proposed method.     

Joint modeling of longitudinal data with a dependent terminal event

ABSTRACT

Longitudinal data often arise in longitudinal follow-up studies, and there may exist a dependent terminal event such as death that stops the follow-up. In this article, we propose a new joint modeling for the analysis of longitudinal data with informative observation times via a dependent terminal event and two latent variables. Estimating equations are developed for parameter estimation, and asymptotic properties of the resulting estimators are established. In addition, a generalization of the joint model with time-varying coefficients for the longitudinal response variable is considered, and goodness-of-fit methods for assessing the adequacy of the model are also provided. The proposed method works well in our simulation studies, and is applied to a data set from a bladder cancer study.     

墨子的科技思想及其科学教育价值

墨子的科技思想不仅闪烁着古代东方的智慧,并堪与古代西方的圣哲媲美,而且具有鲜活的当代科学教育价值。纵观中国的教育,知识至上而忽略能力特别是创造能力发展的教育无所不在。学习和效仿墨子科学教育智慧,对于传承我国悠久的科学思想和创新型国家建设,以及实现伟大民族复兴具有重要意义。     

频偏条件下基于循环平稳的定时估计算法

研究了利用信号的循环平稳统计特性提取定时误差的估计算法,由于性能的优良是建立在大量统计信息的基础上,因而所需的观测时间长度较大,同时算法受频偏的影响也随观测时间长度的增大而增大。针对该特点,研究了频偏对算法性能的影响及存在频偏环境下算法中参数的选择。仿真结果表明,频偏对该类算法的影响不可忽略,尤其是在观测时间长度较大的情况下。实用中应结合具体频偏大小,合理选择参数取值。     

中西“风景”画的差异

中国山水画与欧洲风景画在各自的社会文化背景和绘画中占据着不可替代的位置，有着重要的作用，它们所表现出的差异值得我们去认真研究与思考．只有这样．才能更好地促进中西绘画互相学习，相互借鉴，取长补短，向前发展。     

THE CONTRIBUTION OF PSYCHOANALYTICAL OBSERVATION IN CHILD PROTECTION ASSESSMENTS

In this paper I describe my role in undertaking child protection assessments for children in my work for a Family Centre managed by a national voluntary child care organisation. I explore how psychoanalytical observation provides additional knowledge informing assessments of risk for children. In an example that I discuss in some detail, I show how observation provides a means for assessing relationships between children and parents which leads to informed recommendations to court. In a second example I show how observation can be linked with a therapeutic approach to generate necessary change in parenting capacity. I conclude that observation is an important and effective training for professionals responsible for protecting children from harm.     

Notes from the field: Emotions of place in the production and interpretation of text

Focusing on the emotions generated by place, this paper describes a journey of emotional reactions to place, emotional reflection around cultural difference, followed by later reflection and reassessment. It is argued that the use of emotions as data can provide a mirror through which the taken for granteds of the researcher can be made visible. An example is given of the way that the concept of distance and the intersectionality of emotion, time and space as a confluence of culture and subject positions, can be used to operationalize emotions as data.     

Effects of a single outlier on arma identification

Fox (1972), Box and Tiao (1975), and Abraham and Box (1979) have proposed methods for detecting outliers in time series whose ARMA form is known (or identified). We show that the existence of a single aberrant observation, innovation, or intervention causes an ARMA model to be misidentified using unadjusted autocorrelation (acf) and partial autocorrelation estimates. The magnitude, location, type of outlier, and in some cases the ARMA's parameters, affect the identification outcome. We use variance inflation, signal-to-noise ratios, and acf critical values to determine an ARMA model's susceptibility to misidentifi-cation. Numerical and simulation examples suggest how to iteratively use the outlier detection methods in practice.     

Use and Usability of Assisted Living Facilities for the Elderly: An Observation Study in Gothenburg Sweden

To meet the demographic development, measures were initiated by the Swedish government entailing changed conditions for municipal eldercare, such as assisted living. Participant observation is used to study the daily use of common spaces in 14 assisted living units in Gothenburg. The results show examples where the current use diverges from the intended use and suggest diverging objectives and conflicts of use. The observations indicate that the degree of usability is determined by the physical environment itself in some cases, by the users and by changes in use in other cases, and by a combination of both in some cases.     

关于绿蓝悖论的消解

邓桂芳和徐敏对笔者关于绿蓝悖论的解决方案主要提出两点质疑。对其第一点质疑,笔者指出,直接观察属于感受性,而感受性本质上是私人性的,因此,关于两个证据陈述是否表述同一观察需要给出具有公共性的论证,此类论证包括这两个证据陈述是否可以互推。对其第二点质疑,只需对证据陈述稍加补充便可解决。