A sequential approach to testing seasonal unit roots in high frequency data

In this paper we introduce a sequential seasonal unit root testing approach which explicitly addresses its application to high frequency data. The main idea is to see which unit roots at higher frequency data can also be found in temporally aggregated data. We illustrate our procedure to the analysis of monthly data, and we find, upon analysing the aggregated quarterly data, that a smaller amount of test statistics can sometimes be considered. Monte Carlo simulation and empirical illustrations emphasize the practical relevance of our method.     

Older women's experiences with chronic pain: daily challenges and self-care practices

The subjective nature of chronic pain leads to challenges in describing, treating, and accommodating pain. Twenty older women, who engaged in focus groups, and eight of whom also participated in individual interviews, discussed the influence of chronic pain on their perception of self as well as daily functioning. Managing pain forced many of the women to withdraw from social activities that they valued and interfered with sleep patterns, household tasks and recreational activities. Varied acceptance by social network members added to the challenge of adjusting to complications associated with pain. Self-care practices that supported independence contributed to women's perceived success in daily functioning.     

Statistical methods for handling missing data to align with treatment policy strategy

The International Council for Harmonization (ICH) E9(R1) addendum recommends choosing an appropriate estimand based on the study objectives in advance of trial design. One defining attribute of an estimand is the intercurrent event, specifically what is considered an intercurrent event and how it should be handled. The primary objective of a clinical study is usually to assess a product's effectiveness and safety based on the planned treatment regimen instead of the actual treatment received. The estimand using the treatment policy strategy, which collects and analyzes data regardless of the occurrence of intercurrent events, is usually utilized. In this article, we explain how missing data can be handled using the treatment policy strategy from the authors' viewpoint in connection with antihyperglycemic product development programs. The article discusses five statistical methods to impute missing data occurring after intercurrent events. All five methods are applied within the framework of the treatment policy strategy. The article compares the five methods via Markov Chain Monte Carlo simulations and showcases how three of these five methods have been applied to estimate the treatment effects published in the labels for three antihyperglycemic agents currently on the market.     

Adolescent Bullying and Weapon Carrying: A Longitudinal Investigation

Using four data waves from an ongoing longitudinal study, we examined the longitudinal association between weapon carrying and bullying (i.e., bully, victim, bully‐victim). Participants were 1,042 adolescents (55.9% female) recruited from Texas high schools, including Hispanic (31.7%), White (30.3%), African American (26.6%), and other (11.4%) with a mean age of 15.1 years at baseline. Multivariate logistic regression revealed that only baseline bully‐victim was linked to weapon carrying and only 1 year later (Adjusted odds ratio = 1.76, 95% confidence interval: 1.08, 2.85), after controlling for baseline weapon carrying, age, gender, race, and parent education. No significant longitudinal association was found with bully or victim. Findings emphasize the importance of interventions targeting both bullying perpetrators and victims, while also highlighting the necessity of longitudinal research.     

Concepts travelling across disciplinary fields: the case of the business model

Journal of Management and Governance - Since the beginning of the 2000s, the concept of Business Model has been explored by scholars from a broad range of business studies and particularly those in...