To Share or Not to Share: When Do Toddlers Respond to Another's Needs?

The developmental origins of sharing remain little understood. Using procedures adapted from research on prosocial behavior in chimpanzees, we presented 18- and 25-month-old children with a sharing task in which they could choose to deliver food to themselves only, or to both themselves and another person, thereby making it possible for them to share without personal sacrifice. The potential recipient, a friendly adult, was either silent about her needs and wants or made them explicit. Both younger and older toddlers chose randomly when the recipient was silent. However, when the recipient vocalized her desires 25-month-olds shared whereas younger children did not. Thus, we demonstrate that children voluntarily share valued resources with others by the end of the second year of life, but that this depends on explicit communicative cues about another's need or desire.     

A randomized response procedure for multiple-sensitive questions

The Randomized Response (RR) technique is a well-established interview procedure which guarantees privacy protection in social surveys dealing with sensitive items. The RR method assumes a stochastic mechanism to create uncertainty about the true status of the respondents in order to ensure privacy protection and to avoid tendencies to dissimulate or respond in a socially desirable direction. A very general model for the RR method was introduced by Franklin (Commun Stat Theory Methods 18:489?C505, 1989) when a single-sensitive question is under study. However, since social surveys are often based on questionnaires containing more than a single-sensitive question, the analysis of multivariate RR data is of considerable interest. This paper focuses on the generalization of the Franklin model in a multiple-sensitive question setting and on related inferential issues.     

Conditional approval: discussion points from the PSI conditional approval expert group

The European Agency for the Evaluation of Medicinal Products has recently completed the consultation of a draft guidance on how to implement conditional approval. This route of application is available for orphan drugs, emergency situations and serious debilitating or life-threatening diseases. Although there has been limited experience in implementing conditional approval to date, PSI (Statisticians in the Pharmaceutical Industry) sponsored a meeting of pharmaceutical statisticians with an interest in the area to discuss potential issues. This article outlines the issues raised and resulting discussions, based on the group's interpretation of the legislation. Conditional approval seems to fit well with the accepted regulatory strategy in HIV. In oncology, conditional approval may be most likely when (a) compelling phase II data are available using accepted clinical outcomes (e.g. progression/recurrence-free survival or overall survival) and Phase III has been planned or started, or (b) when data are available using a surrogate endpoint for clinical outcome (e.g. response rate or biochemical measures) from a single-arm study in rare tumours with high response, compared with historical data. The use of interim analyses in Phase III for supporting conditional approval raises some challenging issues regarding dissemination of information, maintenance of blinding, potential introduction of bias, ethics, switching, etc.     

Working late: policy relevance for older workers in the United States

The United States has seen a sizable increase in older worker labour force participation, although how much of this is due to public policy is uncertain. In fact, outside of academic and policy research circles, there has been relatively little attention paid to older workers and the challenges of an aging workforce in that country. Public policymakers have not demonstrated the same interest in expanding employment opportunities for older workers that they have shown for other groups, or that has been seen in other countries. Still, a number of significant pieces of legislation have been enacted over the past several decades that should be making continued employment at later ages easier, more attractive, or more essential financially. This paper examines those policies. However, because of confounding and conflicting influences from elsewhere, public policy initiatives focusing on older worker employment do not appear to be major contributors to rising labour force participation rates at older ages.     

Improving health care delivery to aging adults with disabilities: social work with dual eligibles in a climate of health care reform

Adults aging with disabilities comprise a diverse group. In this article, we identify the prevalence and characteristics of this target population, focusing on adults who are dually eligible for Medicare and Medicaid. We articulate challenges in the delivery of health, social, and support services to adults aging with disabilities, particularly how existing health care policy and financing contributes to fragmentation of care. Finally, we identify opportunities for social workers to advocate for and promote system improvements in the delivery of care for aging adults with disabilities in the current climate of health care reform.     

Naming and claiming workplace sexual harassment in Australia

The persistence of sexual harassment in the workplace and the fact such behaviour remains significantly unreported suggest that legal definitions of sexual harassment may not be well understood. In this paper we explore the naming and claiming of sexual harassment in Australian workplaces, drawing on a unique dataset from a national sexual harassment prevalence survey. We compare a group of individuals who stated they had been sexually harassed according to a legal definition with a group who denied having experienced sexual harassment according to this definition but who went on to report sexually harassing behaviours. The study offers important insights into how workplace sexual harassment comes to be defined and understood in the Australian community, as well as some possible explanations for persistently low rates of formal complaints.     

A Predictive Study of Dirichlet Process Mixture Models for Curve Fitting

This paper examines the use of Dirichlet process mixtures for curve fitting. An important modelling aspect in this setting is the choice between constant and covariate‐dependent weights. By examining the problem of curve fitting from a predictive perspective, we show the advantages of using covariate‐dependent weights. These advantages are a result of the incorporation of covariate proximity in the latent partition. However, closer examination of the partition yields further complications, which arise from the vast number of total partitions. To overcome this, we propose to modify the probability law of the random partition to strictly enforce the notion of covariate proximity, while still maintaining certain properties of the Dirichlet process. This allows the distribution of the partition to depend on the covariate in a simple manner and greatly reduces the total number of possible partitions, resulting in improved curve fitting and faster computations. Numerical illustrations are presented.     

Bayesian Modeling of MPSS Data: Gene Expression Analysis of Bovine Salmonella Infection

Massively Parallel Signature Sequencing (MPSS) is a high-throughput counting-based technology available for gene expression profiling. It produces output that is similar to Serial Analysis of Gene Expression (SAGE) and is ideal for building complex relational databases for gene expression. Our goal is to compare the in vivo global gene expression profiles of tissues infected with different strains of Salmonella obtained using the MPSS technology. In this article, we develop an exact ANOVA type model for this count data using a zero-inflated Poisson (ZIP) distribution, different from existing methods that assume continuous densities. We adopt two Bayesian hierarchical models-one parametric and the other semiparametric with a Dirichlet process prior that has the ability to "borrow strength" across related signatures, where a signature is a specific arrangement of the nucleotides, usually 16-21 base-pairs long. We utilize the discreteness of Dirichlet process prior to cluster signatures that exhibit similar differential expression profiles. Tests for differential expression are carried out using non-parametric approaches, while controlling the false discovery rate. We identify several differentially expressed genes that have important biological significance and conclude with a summary of the biological discoveries.     

Item validity of the physical demands from the Dictionary of Occupational Titles for functional capacity evaluation of clients with chronic back pain

This study assessed the item validity of 15 of the physical demands from the Dictionary of Occupational Titles (DOT), as evaluated in a new approach to functional capacity evaluation (FCE) for clients with chronic back pain, the Gibson Approach to FCE (GAPP FCE). Fifty-two occupational therapists were sent the specifications of the items in the GAPP FCE procedures and were asked to rate the items in terms of item-objective congruence, relevance and difficulty. A response rate of 59.2% was obtained. The majority of the therapists agreed that most of the items were congruent with the objectives based on the definition of the physical demands from the DOT. The items evaluating Balancing and Pushing and Pulling had the lowest item-objective congruence. The evaluation of Balancing and the Lifting, Carrying and Pushing and Pulling of loads greater than light-medium weight (10-16 kg) were not considered significantly relevant. Concerns were raised about the difficulty and safety of the evaluation of Lifting, Carrying and Pushing and Pulling with clients with chronic back pain, particularly if the therapist evaluates the manual handling of medium to heavy loads. These results may have implications for other FCEs, particularly those which are based on the DOT, or when assessing clients with chronic back pain.