Local Box–Cox transformation on time-varying parametric models for smoothing estimation of conditional CDF with longitudinal data

Nonparametric estimation and inferences of conditional distribution functions with longitudinal data have important applications in biomedical studies, such as epidemiological studies and longitudinal clinical trials. Estimation approaches without any structural assumptions may lead to inadequate and numerically unstable estimators in practice. We propose in this paper a nonparametric approach based on time-varying parametric models for estimating the conditional distribution functions with a longitudinal sample. Our model assumes that the conditional distribution of the outcome variable at each given time point can be approximated by a parametric model after local Box–Cox transformation. Our estimation is based on a two-step smoothing method, in which we first obtain the raw estimators of the conditional distribution functions at a set of disjoint time points, and then compute the final estimators at any time by smoothing the raw estimators. Applications of our two-step estimation method have been demonstrated through a large epidemiological study of childhood growth and blood pressure. Finite sample properties of our procedures are investigated through a simulation study. Application and simulation results show that smoothing estimation from time-variant parametric models outperforms the existing kernel smoothing estimator by producing narrower pointwise bootstrap confidence band and smaller root mean squared error.     

Three-level control charts with variable sample size,sampling interval,and control limits

Recently, three-level control chart has been developed for monitoring situations in which an appropriate quality measure uses three discrete levels to classify a product characteristic. In this paper, the variable parameters control charts for multinomial data are developed with a three-level classification scheme. We compare it with various adaptive charts to show that this modified scheme can improve the performance. In order to evaluate and compare the performance of this scheme, adjusted average time to signal is used as the performance measure. Results indicate that the proposed chart has improved performance and is relatively sensitive to small shifts.     

Out of sight and out of mind? A literature review of occupational safety and health leadership and management of distributed workers

Distributed workers – those who work autonomously and remotely from their organisation’s main locations for at least some of their work-time – are an important and growing proportion of the workforce that share common characteristics of temporal and spatial distance. Yet, many leadership styles and management practices assume face-to-face interaction, potentially rendering them less helpful in trying to ensure good occupational safety and health (OSH) outcomes for distributed workers. We conducted a systematic literature review to examine the leadership and management of OSH for distributed workers. Twenty-three papers were identified. Eleven papers identified established leadership styles, including leader-member exchange, (safety specific) transformational and considerate leadership. Twenty papers examined management. Findings from these 20 papers were interpreted as representing resources, deployed through management and utilised by managers to ensure OSH for distributed workers, including communication technologies, social support and a good safety climate. Despite limited research in this area, findings indicate the importance of both leadership and management in ensuring OSH for distributed workers. Findings suggest a fertile area for future enquiry.     

Evaluating the potential contribution of urban ecosystem service to climate change mitigation

Urban Ecosystems - Promoting urban greenery through tree planting strategies has been considered as a measure to mitigate climate change. While it is essential to understand the temporal dynamics...     

Divorce and the cost of housing: evidence from Iran

Divorce trend in Iran has become a serious social concern that is suspected of being influenced by rising housing costs in an oil-based economy. Iran has the highest growth rate of divorce among Islamic countries in the Middle East and North Africa region. Using data from 30 provinces of Iran from 2002 to 2010, this paper examines the relationship between housing costs (house prices and rents) and divorce rate, controlling for other macroeconomic variables such as unemployment, inflation, and education in addition to regional, cultural, traditional, and conventional attitudes toward divorce. By applying panel fixed-effects and dynamic generalized methods of moments methods, our results suggest that increases in housing costs erode marital stability in Iran. Our main results are also supported when we focus on the shocks in housing costs, using the Vector autoregressive based impulse response and variance decomposition analyses of divorce rates at the national level from 1982 to 2010.     

The Clustering of Psychiatric Disorders in High-Risk Gambling Populations

The aims of this study were to examine the associations between psychiatric disorders and pathological gambling (PG) and the clustering of psychiatric disorders in high risk gambler populations. The sample comprised 140 regular gamblers who were recruited from the general public. A variety of self- report and semi structured questionnaires was administered, including the Mini International Neuropsychiatric Interview, The Personality Diagnostic Questionnaire-4th Edition, NORC DSM-IV Screen for Gambling Problems Self- administered and Problem Gambling Severity Index. Axis I and Axis II psychiatric disorders and personality disturbances were found to be more prevalent amongst pathological gamblers than other gamblers with the strongest differences observed for mood and anxiety-related disorders. Almost two-thirds of pathological gamblers reported both an anxiety or mood disorder in conjunction with another type of disorder. These differences between the gambling groups existed even after controlling for gender. The results highlight the high rates of co-morbidity in pathological gamblers in the community and the extent to which anxiety and mood disorders co-existing with other forms of pathology. These results highlight the significant challenges facing treatment services in the treatment of PG and the extent to which this should be treated as the primary disorder.     

Does shared and differentiated transformational leadership predict followers' working conditions and well-being?

Transformational leadership has been widely researched and is associated with followers' performance, attitudes, and subjective well-being at the individual level. Less research has focused on transformational leadership as a group phenomenon. In a survey study (425 followers and 56 leaders), we examined how group-level and differentiated transformational leadership shape followers' perceptions of their working conditions and individual subjective well-being. There was stronger evidence that differentiated transformational leadership's relationships with indicators of well-being was mediated by perceptions of working conditions, in that 10 out of 20 tests for mediation using differentiated transformational leadership were significant, compared to just three out of 20 for group-level transformational leadership. The results suggest that transformational leadership needs to be studied as a group phenomenon considering how group-level perceptions may impact on followers' well-being and that leaders need to realize that there is an “I” in groups and addition to a “we” in groups.