Bayesian inference for Birnbaum–Saunders distribution and its generalization

We present a Bayesian approach for parameter inference of the Birnbaum–Saunders distribution [Birnbaum ZW, Saunders SC. A new family of life distributions. J Appl Probab. 1969;6:319–327], as well as the generalized Birnbaum–Saunders distribution developed by Owen [A new three-parameter extension to the Birnbaum–Saunders distribution. IEEE Trans Reliab. 2006;55:475–479], in the presence of random right-censored data. To handle the instance of commonly occurred censored observations, we utilize the data augmentation technique [Tanner MA, Wong WH. The calculation of posterior distributions by data augmentation. J Amer Statist Assoc. 1987;82(398):528–540] to circumvent the arduous expressions involving the censored data in posterior inferences. Simulation studies are carried out to assess performance of these methods under different parameter values, with small and large sample sizes, as well as various degrees of censoring. Two real data are analysed for illustrative purpose.     

Evaluation of an avatar-based training program to promote suicide prevention awareness in a college setting

Objective: Training programs exist that prepare college students, faculty, and staff to identify and support students potentially at risk for suicide. Kognito is an online program that trains users through simulated interactions with virtual humans. This study evaluated Kognito's effectiveness in preparing users to intervene with at-risk students. Participants: Training was completed by 2,727 university students, faculty, and staff from April, 2014 through September, 2015. Methods: Voluntary and mandatory participants at a land-grant university completed Kognito modules designed for higher education, along with pre- and post-assessments. Results: All modules produced significant gains in reported Preparedness, Likelihood, and Self-Efficacy in intervening with troubled students. Despite initial disparities in reported abilities, after training participants reported being similarly capable of assisting at-risk students, including LGBTQ and veteran students. Conclusions: Kognito training appears to be effective, on a large scale, in educating users to act in a facilitative role for at-risk college students.     

Statistical Estimation of the Casual Effect of Social Economy on Subjective Well-Being

It is well known that measuring the noneconomic outcomes produced by social economy organizations is fairly difficult and complex. Usually, social economy organizations feature participatory and democratic decision-making processes that help create social capital and relational goods, and they are interested in social integration; accordingly, they tend to create an organizational culture that encourages their workers to contribute to local communities. Therefore, the hypothesis that the increased activities of social economy organizations have a causal effect on the subjective well-being of the people living near those organizations is highly plausible. In this paper, we estimate the causal effect and attempt to test the hypothesis statistically by using a dataset called the “Seoul Survey,” which provides observations on the subjective well-being of 45,496 citizens living in Seoul and the size of social economy organizations. Controlling for variables at the district level and the appropriate socioeconomic characteristics of each individual in the dataset, we find that the size of social organizations is highly significant.     

Transformational leadership and performance outcomes: Analyses of multiple mediation pathways

Transformational leadership (TFL) has been shown to affect employees' job performance, and the literature offers a large variety of explanatory processes. Integrating the diverse literature related to the mechanisms that mediate the TFL-performance relationship, the current study identified five core mechanisms—affective, motivational, identification, social exchange, and justice enhancement—that are consistent with established social and psychological theories. Meta-analysis involving > 600 samples was conducted to test these mechanisms. General support was found for each of the five mechanisms. The findings showed that TFL was related to variables that represented these mechanisms, which in turn were associated with non-self-report measures of employees' task performance, citizenship behavior, and innovative behavior. An integrative model was further proposed and tested to show the central role of leader-member exchange in the relationships between TFL, other mediating variables, and performance outcomes. This study contributes to the literature by strengthening researchers' theoretical understanding of the major social and psychological processes by which transformational leaders promote followers' job performance.     

Sensitivity of Concentration and Risk Predictions in the PRESTO and MMSOILS Multimedia Models: Regression Technique Assessment

This paper describes the application of two multimedia models, PRESTO and MMSOILS, to predict contaminant migration from a landfill that contains an organic chemical (methylene chloride) and a radionuclide (uranium-238). Exposure point concentrations and human health risks are predicted, and distributions of those predictions are generated using Monte Carlo techniques. Analysis of exposure point concentrations shows that predictions of uranium-238 in groundwater differ by more than one order of magnitude between models. These differences occur mainly because PRESTO simulates uranium-238 transport through the groundwater using a one-dimensional algorithm and vertically mixes the plume over an effective mixing depth, whereas MMSOILS uses a three-dimensional algorithm and simulates a plume that resides near the surface of the aquifer.A sensitivity analysis, using stepwise multiple linear regression, is performed to evaluate which of the random variables are most important in producing the predicted distributions of exposure point concentrations and health risks. The sensitivity analysis shows that the predicted distributions can be accurately reproduced using a small subset of the random variables. Simple regression techniques are applied, for comparison, to the same scenarios, and results are similar. The practical implication of this analysis is the ability to distinguish between important versus unimportant random variables in terms of their sensitivity to selected endpoints.     

Interaction Effects of Gender,SES, and Race‐Ethnicity on Postsecondary Educational Choices of U.S. Students

The authors present data for a subsample of the National Education Longitudinal Study of 1988 (NELS:88; 1996). All participants in the study had attended a postsecondary institution within 2 years of graduation from high school and had selected a field of study. Educational choices were categorized by predominant Holland types (e.g., Realistic, Social, Conventional). There was a 3‐way Gender × SES × Race‐Ethnicity interaction. Race‐ethnicity effects were strongest for men at lower SES levels and weakest for women at high SES levels. The nature of gender and SES effects differed across racial‐ethnic groups.     

Evaluating the Economic Impact of Casino Liberalization in Macao

This paper aims to evaluate the economic impact after Macao decided to liberalize its gaming industry. By analysing both objective data of official statistics and subjective data of the perceptions of quality of life, we painted a picture of mixed blessings. Although objective indicators showed strong economic growth in terms of a rise in per capita GDP and public revenue as well as a decline in unemployment rate, subjective indicators revealed that local residents were less than optimistic about their own employment outlook and did not perceive any improvement in their overall economic situation. While casino liberalization brought forth tremendous economic gain, the general population did not subjectively feel the benefits. An integrative analysis of both objective and subjective indicators would therefore allow us to look closer how residents?? lives in the micro-level could have been adversely affected by the prosperous economic outlook at the macro-level.     

Adapting the sample size planning of a phase III trial based on phase II data

Traditionally, in clinical development plan, phase II trials are relatively small and can be expected to result in a large degree of uncertainty in the estimates based on which Phase III trials are planned. Phase II trials are also to explore appropriate primary efficacy endpoint(s) or patient populations. When the biology of the disease and pathogenesis of disease progression are well understood, the phase II and phase III studies may be performed in the same patient population with the same primary endpoint, e.g. efficacy measured by HbA1c in non-insulin dependent diabetes mellitus trials with treatment duration of at least three months. In the disease areas that molecular pathways are not well established or the clinical outcome endpoint may not be observed in a short-term study, e.g. mortality in cancer or AIDS trials, the treatment effect may be postulated through use of intermediate surrogate endpoint in phase II trials. However, in many cases, we generally explore the appropriate clinical endpoint in the phase II trials. An important question is how much of the effect observed in the surrogate endpoint in the phase II study can be translated into the clinical effect in the phase III trial. Another question is how much of the uncertainty remains in phase III trials. In this work, we study the utility of adaptation by design (not by statistical test) in the sense of adapting the phase II information for planning the phase III trials. That is, we investigate the impact of using various phase II effect size estimates on the sample size planning for phase III trials. In general, if the point estimate of the phase II trial is used for planning, it is advisable to size the phase III trial by choosing a smaller alpha level or a higher power level. The adaptation via using the lower limit of the one standard deviation confidence interval from the phase II trial appears to be a reasonable choice since it balances well between the empirical power of the launched trials and the proportion of trials not launched if a threshold lower than the true effect size of phase III trial can be chosen for determining whether the phase III trial is to be launched.     

Psychometric Analysis of the Orientations to Happiness Questionnaire in Taiwanese Undergraduate Students

The aim of this study was to examine the psychometric properties of the Orientations to Happiness Questionnaire (OHQ; Peterson et al. in J Happiness Stud 6(1):25–41, 2005) in Taiwanese students. The participants were 578 undergraduate students (M_age = 18.64, SD = 1.02) and completed the OHQ, satisfaction with life scale (Diener et al. in J Personality Assess 49:71–75, 1985), and subjective happiness. Confirmation factor analysis indicated that a three-factor model with 17 items was the better fit model. Cross-validation also supported the modified Chinese version of the OHQ. Besides, the OHQ significantly predicted life satisfaction and subjective happiness with an exception of life of pleasure. Overall, it was concluded that the Chinese version of the OHQ would be useful for assessing individual’s orientations to happiness.     

Alegría! Flow in Leisure and Life Satisfaction: The Mediating Role of Event Satisfaction Using Data from an Acrobatics Show

The aim of the current study was to examine the role of satisfaction-with-event as a mediator in the relations between flow and life satisfaction based on the bottom-up theory (Andrews and Withey in Social indicators of well-being: Americans’ perceptions of life quality. Plenum, New York, 1976; Lee et al. in J Macromarketing 22(2): 158–169, 2002). Four hundred and thirty-four participants with a mean age of 35.60 (SD = 11.76) were recruited from the audience of a “Cirque du Soleil” acrobatics show, performed in Taiwan in 2009. Participants completed the flow scale (Csikszentmihalyi in Flow: the psychology of optimal experience. Harper & Row, New York, 1990), a satisfaction-with-event scale (Lin and Hsu in Mark Rev 3(4): 497–528, 2008), and a satisfaction-with-life scale (Diener et al. in J Pers Assess 49:71–75, 1985) immediately after viewing the show. Structural equation modeling was conducted to examine our hypothesis that satisfaction-with-event levels would fully mediate the relationship between flow and overall life satisfaction. Results supported our prediction and are discussed in terms of bottom-up theory. Implications of the study are also provided for the leisure managers.