Marginal and hazard ratio specific random data generation: Applications to semi-parametric bootstrapping

Cox's partial likelihood for censored time-to-event data can be interpreted as a permutation probability, whereby covariate values are permuted to the observed times-to-event and censoring times. This interpretation facilitates a simple method for jointly generating times-to-event and covariate tuples with considerable flexibility, including time dependence of the hazard ratio and specification of both the marginal time-to-event and covariate distributions. This interpretation also facilitates a method for semi-parametric bootstrapping of hazard ratio estimators.     

Family Dilemmas and Secrets: parents' disclosure of information to their adult offspring with learning disabilities

This paper describes the role parents play in providing knowledge of learning disability to their adult offspring with learning disabilities. Data were derived from an in-depth qualitative study of the nature of parent-adult-offspring co-residence. The findings reveal that while parents recognised and had to deal with the stigma learning disability exerted in their own lives, they had taken steps to prevent their adult offspring from having to deal with similar difficulties. It is argued that it remains the case that learning disability is treated as a stigmatised identity and as such is rendered invisible through the strategic control of information. However, findings point towards the conclusion that there has been a cultural reversal in how this process is managed.     

Defining child abuse: Exploring variations in ratings of discipline severity among child welfare practitioners

This study investigated child welfare practitioners’ ratings of the severity of parental discipline practices. Ratings varied by the type of act, age of the child, and by chronicity. Exploratory investigation into changes across time found that current practitioners (N = 27) rated several practices (e.g. spanking and shaking) as more severe than did professionals (N = 24) sampled in 1977. Results underscore the complexity of defining child maltreatment and offer implications for practitioners, applied researchers, and child welfare policy makers.The authors Stephen D. Whitney, Emiko A. Tajima, Todd I. Herrenkohl, and Bu Huang are affiliated with the School of Social Work, University of Washington.Work on this project is supported by funds from the Social Work Prevention Research Center, School of Social Work, University of Washington (National Institute of Mental Health Grant R24MH56599, Lewayne Gilchrist, PI) and by the University of Washington Royalty Research Fund.     

Linking perceived organizational support with employee work outcomes in a Chinese context: Organizational identification as a mediator

Perceived organizational support (POS) is viewed as an important explanatory framework for understanding the relationship between employees and the workplace, and is regarded by some researchers as central in understanding job-related attitudes and behaviors of employees. However, less research has taken into account the role of organizational identification, which reflects how individuals define the self with respect to their organization, as a potential influence on such relationships. Drawing on a cross-organizational sample of 238 subordinate-supervisor dyads from the People’s Republic of China, we examined whether organizational identification mediates the effect of perceived organizational support (POS) on work outcomes including turnover intentions, work performance, and organizational citizenship behavior (OCB). Results from the current study showed that organizational identification fully mediates the relation of POS to OCB-directed to individuals, and partially mediates relations between POS and other work outcomes (turnover intention, work performance, OCB-directed to organization). Implications for management theory and practice are discussed.     

Use of Multicriteria Decision Analysis to Support Weight of Evidence Evaluation

Weight of evidence (WOE) methods are key components of ecological and human health risk assessments. Most WOE applications rely on the qualitative integration of diverse lines of evidence (LOE) representing impact on ecological receptors and humans. Recent calls for transparency in assessments and justifiability of management decisions are pushing the community to consider quantitative methods for integrated risk assessment and management. This article compares and contrasts the type of information required for application of individual WOE techniques and the outcomes that they provide in ecological risk assessment and proposes a multicriteria decision analysis (MCDA) framework for integrating individual LOE in support of management decisions. The use of quantitative WOE techniques is illustrated for a hypothetical but realistic case study of selecting remedial alternatives at a contaminated aquatic site. Use of formal MCDA does not necessarily eliminate biases and judgment calls necessary for selecting remedial alternatives, but allows for transparent evaluation and fusion of individual LOE. It also provides justifiable methods for selecting remedial alternatives consistent with stakeholder and decision‐maker values.     

Leadership research and cognitive neuroscience: The state of this union

Advances in cognitive neuroscience and other approaches to understanding human behavior from a biological standpoint are only now beginning to filter into leadership research. The purpose of this introduction to the Leadership Quarterly Special Issue on the Biology of Leadership is to outline the organizational cognitive neuroscience approach to leadership research, and show how such an approach can fruitfully inform both leadership and neuroscientific research. Indeed, we advance the view that the further application of cognitive neuroscientific techniques to leadership research will pay great dividends in our understanding of effective leadership behaviors and as such, a future symbiosis between the two fields is a necessity.     

Modeling Correlated Discrete Uncertainties in Event Trees with Copulas

Modeling the dependence between uncertainties in decision and risk analyses is an important part of the problem structuring process. We focus on situations where correlated uncertainties are discrete, and extend the concept of the copula‐based approach for modeling correlated continuous uncertainties to the representation of correlated discrete uncertainties. This approach reduces the required number of probability assessments significantly compared to approaches requiring direct estimates of conditional probabilities. It also allows the use of multiple dependence measures, including product moment correlation, rank order correlation and tail dependence, and parametric families of copulas such as normal copulas, t‐copulas, and Archimedean copulas. This approach can be extended to model the dependence between discrete and continuous uncertainties in the same event tree.     

Self‐Awareness in Human and Chimpanzee Infants: What Is Measured and What Is Meant by the Mark and Mirror Test?

The objective study of self‐recognition, with a mirror and a mark applied to the face, was conducted independently by Gallup (1970) for use with chimpanzees and monkeys, and by Amsterdam (1972) for use with infant humans. Comparative psychologists have followed the model (and assumptions) set by Gallup, whereas developmental psychologists have followed a different model (e.g., Lewis & Brooks‐Gunn, 1979). This article explores the assumptions in the definitions and methods of self‐recognition assessments in the 30 years since these initial studies, and charts the divergence between the developmental mark test and the comparative mark test. Two new studies, 1 with infant chimpanzees and 1 with infant humans, illustrate a reconciliation of the 2 approaches. Overt application of the mark, or other procedures related to how the mark is discovered, did not enhance mirror self‐recognition. In contrast, maternal scaffolding appears to enhance performance, perhaps by eliciting well‐rehearsed verbal responses (i.e., naming self). When comparable testing procedures and assessment criteria are used, chimpanzee and human infants perform comparably. A combined developmental comparative approach allows us to suggest that mirror self‐recognition may be based on a specific aspect of mental representation, the cognitive ability to symbolize.     

Using categorical markers as auxiliary variables in log‐rank tests and hazard ratio estimation

Markers, which are prognostic longitudinal variables, can be used to replace some of the information lost due to right censoring. They may also be used to remove or reduce bias due to informative censoring. In this paper, the authors propose novel methods for using markers to increase the efficiency of log‐rank tests and hazard ratio estimation, as well as parametric estimation. They propose a «plug‐in» methodology that consists of writing the test statistic or estimate of interest as a functional of Kaplan–Meier estimators. The latter are then replaced by an efficient estimator of the survival curve that incorporates information from markers. Using simulations, the authors show that the resulting estimators and tests can be up to 30% more efficient than the usual procedures, provided that the marker is highly prognostic and that the frequency of censoring is high.