Variable selection for survival data with a class of adaptive elastic net techniques

The accelerated failure time (AFT) models have proved useful in many contexts, though heavy censoring (as for example in cancer survival) and high dimensionality (as for example in microarray data) cause difficulties for model fitting and model selection. We propose new approaches to variable selection for censored data, based on AFT models optimized using regularized weighted least squares. The regularized technique uses a mixture of \(\ell _1\) and \(\ell _2\) norm penalties under two proposed elastic net type approaches. One is the adaptive elastic net and the other is weighted elastic net. The approaches extend the original approaches proposed by Ghosh (Adaptive elastic net: an improvement of elastic net to achieve oracle properties, Technical Reports 2007) and Hong and Zhang (Math Model Nat Phenom 5(3):115–133 2010), respectively. We also extend the two proposed approaches by adding censoring observations as constraints into their model optimization frameworks. The approaches are evaluated on microarray and by simulation. We compare the performance of these approaches with six other variable selection techniques-three are generally used for censored data and the other three are correlation-based greedy methods used for high-dimensional data.     

‘Back to our Roots?’ Re-visiting psychoanalytically-informed baby and young child observation in the education of student social workers

While there is a well-established literature on psychoanalytically-informed baby and young child observation in social work education, little has been published recently. This paper reviews the rationale for its use, evaluating its impact on students’ learning in the light of contemporary policy and practice contexts facing social work education. Analysis of feedback gained from a recent cohort, identifies three ways in which learning through baby and young child observation contributes: firstly, students encounter and learn about the complexity of child development from the direct experience of observing and secondly, observing facilitates the development of important skills for practice; students’ ‘use of self’. Thirdly, through observing, students describe how they develop the capacity to take-up and sustain a professional role. Well-structured teaching and learning through observation is therefore shown to provide a rigorous, theoretically-grounded contribution to the training of university-based social work students entering this complex and challenging professional field.     

The influence of FDA advisory information and black box warnings on individual use of prescription antidepressants

We examine how use of antidepressant medications is influenced by Food and Drug Administration (FDA) warnings about the increased risk of suicidality associated with pediatric antidepressant use. With individual-level data on antidepressant use from the Medical Expenditure Panel Survey, we consider whether consumer responses to FDA warnings differ among targeted (children) and non-targeted (adult) age-groups. Because the warning labels specifically mentioned new users, we examine separately the effects of the warnings on initiations of antidepressant therapy and on continued use of antidepressants. We find evidence consistent with reduced initiation of antidepressant use among the intended population of children, and that usage among children with more highly educated parents responded earlier to FDA information. However, we also find spillover effects of reduced initiation among the non-targeted population of adults. Overall, our results indicate that the FDA warning may have led consumers to perceive risks beyond those specifically mentioned.     

Distractions N' Driving: video game simulation educates young drivers on the dangers of texting while driving

The proliferation of portable communication and entertainment devices has introduced new dangers to the driving environment, particularly for young and inexperienced drivers. Graduate students from George Mason University illustrate a powerful, practical, and cost-effective program that has been successful in educating these drivers on the dangers of texting while driving, which can easily be adapted and implemented in other communities.     

Designing for multiple global user populations: increasing resource allocation efficiency for greater sustainability

This paper proposes a method to identify opportunities for increasing the efficiency of raw material allocation decisions for products that are simultaneously targeted at multiple user populations around the world. The values of 24 body measures at certain key percentiles were used to estimate the best-fitting anthropometric distributions for female and male adults in nine national populations, which were selected to represent the diverse target markets multinational companies must design for. These distributions were then used to synthesize body measure data for combined populations with a 1:1 female:male ratio. An anthropometric range metric (ARM) was proposed for assessing the variation of these body measures across the populations. At any percentile, ARM values were calculated as the percentage difference between the highest and lowest anthropometric values across the considered user populations. Based on their magnitudes, plots of ARM values computed between the 1st and 99 th percentiles for each body measure were grouped into low, medium, and high categories. This classification of body measures was proposed as a means of selecting the most suitable strategies for designing raw material-efficient products. The findings in this study and the contributions of subsequent work along these lines are expected to help achieve greater efficiencies in resource allocation in global product development.     

Group decision-making: An economic analysis of social influence and individual difference in experimental juries

In jury decision-making, individual viewpoints must converge to reach a group consensus. Convergence of viewpoints may reflect reasonable compromises, for example if jury deliberations reflect informational influences and social learning which allow individual jurors to correct biases, misunderstandings and/or imperfect recall of evidence. Conversely, some individuals may converge towards others’ viewpoints because of normative influences including peer pressure and preferences for conformity and these can generate biases in the final jury judgements. This paper presents experimental data showing that groups do have a significant tendency to compromise in jury-like settings. Econometric evidence shows that group characteristics, including the presence of acquaintances and strangers within the jury group, affect the extent of compromise. The implications are that jury deliberations may be biased by factors not relevant to a specific case, limiting the objectivity of jury decisions.     

z Test for the significance of the mean of a stable probability distribution with 1<α≤2

The analysis of data using a stable probability distribution with tail parameter α<2 (sometimes called a Pareto–Levy distribution) seems to have been avoided in the past in part because of the lack of a significance test for the mean, even though it appears to be the correct distribution to use for describing returns in the financial markets. A z test for the significance of the mean of a stable distribution with tail parameter 1<α≤2 is defined. Tables are calculated and displayed for the 5% and 1% significance levels for a range of tail and skew parameters α and β. Through the use of maximum likelihood estimates, the test becomes a practical tool even when α and β are not that accurately determined. As an example, the z test is applied to the daily closing prices for the Dow Jones Industrial average from 2 January 1940 to 19 March 2010.     

Postconflict Reconciliation: Intergroup Forgiveness and Implicit Biases in Northern Ireland

Even after a conflict has formally ended, there is still a need for postconflict reconciliation and the building of mutual forgiveness and trust between communities. This article addresses psychological processes crucial to moving beyond a history of violent sectarian conflict in Northern Ireland. We investigated the predictors of intergroup forgiveness, in terms of intergroup emotions, infrahumanization, empathy, and intergroup contact. Intergroup trust and measures of implicit intergroup bias were also explored in this area of real intergroup conflict. The results are discussed in terms of their implications for postconflict reconciliation in Northern Ireland and other conflict areas.