Optimal designs for both model discrimination and parameter estimation

The KL-optimality criterion has been recently proposed to discriminate between any two statistical models. However, designs which are optimal for model discrimination may be inadequate for parameter estimation. In this paper, the DKL-optimality criterion is proposed which is useful for the dual problem of model discrimination and parameter estimation. An equivalence theorem and a stopping rule for the corresponding iterative algorithms are provided. A pharmacokinetics application and a bioassay example are given to show the good properties of a DKL-optimum design.     

A segmented regression model for event history data: an application to the fertility patterns in Italy

We propose a segmented discrete-time model for the analysis of event history data in demographic research. Through a unified regression framework, the model provides estimates of the effects of explanatory variables and jointly accommodates flexibly non-proportional differences via segmented relationships. The main appeal relies on ready availability of parameters, changepoints, and slopes, which may provide meaningful and intuitive information on the topic. Furthermore, specific linear constraints on the slopes may also be set to investigate particular patterns. We investigate the intervals between cohabitation and first childbirth and from first to second childbirth using individual data for Italian women from the Second National Survey on Fertility. The model provides insights into dramatic decrease of fertility experienced in Italy, in that it detects a ‘common’ tendency in delaying the onset of childbearing for the more recent cohorts and a ‘specific’ postponement strictly depending on the educational level and age at cohabitation.     

The role of exercise on the innate immunity of the elderly

The increased life span in human population has shown that some diseases, as infections, cancer and autoimmune phenomena, occur more frequently in the elderly than in the younger. We describe the ageing process involving the innate immune system and the improvement given by moderate physical activity. In addition, we discuss the altered neutrophil granulocytes function, the role of macrophages and natural killer cells, besides the influence of cytokines and secretory IgA. The acquired information help us to explain how these changes could favor the onset of diseases in the elderly and how they may boost their immune function.     

Poverty and psychological distress in Latin America

The objective of this paper is three-fold: first, to study the psychological distress of the Latin American poor. Second, to study differences in psychological distress between the poor and the relatively wealthy in Latin America. Third, to study how economic growth impacts the psychological well-being of the poor.This paper uses micro-level information from the Gallup 2007 Survey for 16 Latin American countries to study psychological distress of the poor in Latin America; the survey is representative at the country level. The investigation works with approximately 12,500 observations. Psychological distress is measured on the basis of a set of questions regarding a person’s emotional situation the day before he/she answered the questionnaire.The investigation finds out that the poor show greater psychological distress than the wealthy and that the gap is statistically significant. However, it would be inappropriate to attempt predicting a person’s psychological well-being on the basis of his/her poverty condition alone, since many factors affect people’s psychological well-being. The paper also shows that rapid economic growth seems to be detrimental to the psychological well-being of the poor, and that the impact of economic growth on psychological well-being differs between the poor and the relatively wealthy.     

Conclusion: Recommendations for how practitioners, researchers, and policymakers can promote youth purpose

Initially drawing from, yet then expanding on the research discussed in this volume, this article discusses specific measures that practitioners, researchers, and policymakers can take to support purpose among youth. Strategies for educators include utilizing practical purpose teaching tools, such as purpose interviews, purpose-related discussions, whole classroom and school community games, and purpose survey methodologies. Research strategies include expanding the study of youth purpose to more diverse groups of young people, and developing more succinct tools to assess purpose in research. Finally, the article discusses policy measures to promote purpose, including modification of current academic testing practices, expanding the breadth of course and extracurricular experiences in schools to provide opportunities for purpose development, and integrating purpose promotion skill-building into existing teacher education programs.     

The evolution of employee engagement: Towards a social and contextual construct for balancing individual performance and wellbeing dynamically

Research demonstrates that high Employee Engagement (EE) sustains job satisfaction and performance among staff. This literature review analyses the evolution of EE, highlighting the theoretical frameworks used to explain the concept, the measurement scales adopted by researchers and the principal antecedents and outcomes relating to EE that have been progressively considered along the way. Three main findings emerge from the analysis. First, we highlight the social and relational nature of EE, providing a more sociological interpretation of this phenomenon. Second, we underscore the fact that EE is dynamic, and when combined with modern digital technologies, it can be studied through innovative approaches. Third, we discuss how EE could be a fundamental ingredient in shifting towards a human centred approach through which balancing individuals’ wellbeing and performance. We discuss the implications of these findings, highlighting the necessity to rethink EE in relation to the new normal ushered in by Covid-19, and the increasing role of hybrid working.