A Bayesian hierarchical mixture model for platelet-derived growth factor receptor phosphorylation to improve estimation of progression-free survival in prostate cancer

Summary.  Advances in understanding the biological underpinnings of many cancers have led increasingly to the use of molecularly targeted anticancer therapies. Because the platelet-derived growth factor receptor (PDGFR) has been implicated in the progression of prostate cancer bone metastases, it is of great interest to examine possible relationships between PDGFR inhibition and therapeutic outcomes. We analyse the association between change in activated PDGFR (phosphorylated PDGFR) and progression-free survival time based on large within-patient samples of cell-specific phosphorylated PDGFR values taken before and after treatment from each of 88 prostate cancer patients. To utilize these paired samples as covariate data in a regression model for progression-free survival time, and be cause the phosphorylated PDGFR distributions are bimodal, we first employ a Bayesian hierarchical mixture model to obtain a deconvolution of the pretreatment and post-treatment within-patient phosphorylated PDGFR distributions. We evaluate fits of the mixture model and a non-mixture model that ignores the bimodality by using a supnorm metric to compare the empirical distribution of each phosphorylated PDGFR data set with the corresponding fitted distribution under each model. Our results show that first using the mixture model to account for the bimodality of the within-patient phosphorylated PDGFR distributions, and then using the posterior within-patient component mean changes in phosphorylated PDGFR so obtained as covariates in the regression model for progression-free survival time, provides an improved estimation.     

‘You Feel Sad?’ Emotion Understanding Mediates Effects of Verbal Ability and Mother–Child Mutuality on Prosocial Behaviors: Findings from 2 Years to 4 Years

Early individual differences in prosocial behaviors are pivotal for children's peer relationships. To investigate the interplay among verbal ability, emotion understanding, and mother–child mutuality as predictors of prosocial behaviors, we observed 102 children at the ages of two, three, and four. All time points included verbal ability and emotion understanding tests and both video‐based and maternal ratings of prosocial behavior. The first two time points also included video‐based ratings of mother–child mutuality. The third time point included teacher ratings of prosocial behavior and an experimental task. Regression analysis demonstrated robust associations between emotion understanding at the age of three and prosocial behavior at the age of four. Path analysis showed that emotion understanding at the age of three mediated associations between verbal ability/mother–child mutuality at the age of two and prosocial behavior at the age of four.     

WHEN SHOULD DRIVERS BE ENCOURAGED TO CARPOOL IN HOV LANES?

Policies to encourage carpooling in high‐occupancy vehicle (HOV) lanes have been adopted in the United States to lower congestion and reduce air pollution. We analytically model highway congestion and other vehicle‐related externalities. Encouraging carpooling decreases total costs when congestion relief in mainline lanes outweighs increased HOV lane congestion. Importantly, entry of new drivers via induced demand can negate the benefits of increased carpooling. Using 10 years of traffic data from Los Angeles we estimate time and route‐specific marginal external costs. Because costs vary substantially across routes, hours, and days, current policies to promote carpooling will often increase social costs. (JEL R41, R48, Q53)     

Global value chains for medical gloves during the COVID-19 pandemic: Confronting forced labour through public procurement and crisis

This paper evaluates ways in which labour issues in global value chains for medical gloves have been affected by, and addressed through, the COVID-19 pandemic. It focuses on production in Malaysia and supply to the United Kingdom's National Health Service and draws on a large-scale survey with workers and interviews with UK government officials, suppliers and buyers. Adopting a Global Value Chain (GVC) framework, the paper shows how forced labour endemic in the sector was exacerbated during the pandemic in the context of increased demand for gloves. Attempts at remediation are shown to operate through both a reconfigured value chain in which power shifted dramatically to the manufacturers and a context where public procurement became higher in profile than ever before. It is argued that the purchasing power of governments must be leveraged in ways that more meaningfully address labour issues, and that this must be part of value chain resilience.     

The Business of Caring: Women's Self‐Employment and the Marketization of Care

Our goal in this article is to contribute to a differentiated analysis of paid caring work by considering whether and how women's experiences of such work is shaped by their employment status (for example, self‐employed versus employee) and the nature of care provided (direct or indirect). Self‐employed care workers have not been widely studied compared with other types of care workers, such as employees providing domestic or childcare in private firms or private homes. Yet their experiences may be quite distinct. Existing research suggests that self‐employed workers earn less than employees and are often excluded from employment protection. Nonetheless, they often report greater autonomy and job satisfaction in their day‐to‐day work. Understanding more about the experiences of self‐employed caregivers is thus important for enriching existing theory, research and policy on the marketization of care. Addressing this gap, our article explores the working conditions, pay and levels of satisfaction of care workers who are self‐employed. We draw on interviews from a small‐scale study of Canadian women engaged in providing direct care (for example, childcare) and indirect care (for example, cleaning).     

Effect of Trajectories of Friends' and Parents' School Involvement on Adolescents' Engagement and Achievement

In a sample of 527 academically at‐risk youth, we investigated trajectories of friends' and parents' school involvement across ages 12–14 and the joint contributions of these trajectories to adolescents' age 15 school engagement and academic achievement. Girls reported higher levels of friends' and parents' school involvement than boys. Both parents' and friends' school involvement declined across ages 12–14. Combined latent growth models and structural equation models showed effects of the trajectories of friends' and parents' school involvement on adolescents' age 15 school engagement and academic achievement, over and above adolescents' prior performance. These effects were additive rather than interactive. Strategies for enhancing parent involvement in school and students' affiliation with peers who are positively engaged in school are discussed.