Optimal adaptive sequential designs for crossover bioequivalence studies

In prior works, this group demonstrated the feasibility of valid adaptive sequential designs for crossover bioequivalence studies. In this paper, we extend the prior work to optimize adaptive sequential designs over a range of geometric mean test/reference ratios (GMRs) of 70–143% within each of two ranges of intra‐subject coefficient of variation (10–30% and 30–55%). These designs also introduce a futility decision for stopping the study after the first stage if there is sufficiently low likelihood of meeting bioequivalence criteria if the second stage were completed, as well as an upper limit on total study size. The optimized designs exhibited substantially improved performance characteristics over our previous adaptive sequential designs. Even though the optimized designs avoided undue inflation of type I error and maintained power at 80%, their average sample sizes were similar to or less than those of conventional single stage designs. Copyright © 2015 John Wiley & Sons, Ltd.     

Leadership in Social Work Education and the Social Change Model of Leadership

Leadership is a topic of international debate in both social work education and practice. Questions remain, however, regarding what specific models of leadership should be emphasized and how leadership content should be infused within the social work curriculum. This paper seeks to contribute to the ongoing discussion about the infusion of leadership within social work education. Specifically, this paper shares the design and development of a graduate-level social work course in program evaluation that infused education around the social change model of leadership (SCM) and then explores qualitatively how 39 graduate students interpreted and applied this model of leadership through an experiential community-based evaluation project. Findings of this study suggest that students utilized the values identified in the SCM in a range of ways to understand and interpret their leadership experience both in their collaborative groups and in their partnerships with community-based organizations. Community organizations also reported benefiting from the experience in partnership with the students. Implications are discussed in relation to the potential value and impact of this model for social work education.     

The Active Audience? Gurus,Management Ideas and Consumer Variability

This study draws on an active audience perspective to develop a better understanding of mass audiences' attraction towards popular management ideas. It focuses on audience members' own experiences and, in particular, what audience activities actually play a role in shaping mass attraction, and how the deployment of these activities may vary. Analysing 65 in‐depth interviews with management practitioners in their role as audience members of guru seminars, the authors identify different key consumption activities, and explain how individual management practitioners may shift in consumption orientation throughout the communication process. This paper argues that such a broader and more dynamic understanding of consumption activity is essential in understanding the success and impact of management ideas, and opens several fruitful research directions.     

School‐based human rights education: case studies in Hong Kong secondary schools

In an era of rapid globalization, space and time are seriously compressed. People from different nations, cultures, religions and other backgrounds have become much more interconnected and interdependent. Since people are rapidly intermingling, what values should be considered as standards and norms in regulating this situation, so that people of different backgrounds can relate peacefully to each other with mutual respect? United Nations (UN) human rights standards could be considered as sets of shared global norms and values in a search for global ethics. As a consequence, the UN has been eager to promote human rights education (HRE), aiming at the cultivation of a human rights culture. This paper reports on two case studies of school‐based curriculum development of HRE in two Hong Kong secondary schools. We also recommend some research directions important for the implementation of HRE in schools. It is hoped that the paper can provide some insight into the development of quality HRE in schools.     

The relative impact of complementary leader behaviors: Which matter most?

Despite conceptual overlap between the transformational–transactional model of leadership and the Ohio State two-factor model (i.e., Consideration and Initiating Structure), no systematic research examines correspondence among these behaviors or estimates their relative validities across a common set of outcomes. The current studies a) examine the factor structure of five key dimensions of these two models (transformational, contingent reward, laissez faire, Initiating Structure, and Consideration) and b) estimate relative validities with respect to two organizational outcomes: employee job satisfaction and perceptions of leadership effectiveness. Although results of a meta-analysis show that transformational leadership is significantly related to both Consideration (ρ = .74) and Initiating Structure (ρ = .50), results of two primary studies provide support for the independence of these leadership dimensions. Moreover, dominance analyses (Budescu, 1993) reveal that Consideration and transformational leadership are the most important predictors of employee job satisfaction and ratings of leadership effectiveness, and each had incremental validity when controlling for the effects of the other. Overall, results suggest that dimensions from both models are important predictors of employee outcomes.     

一个自动扫描电子显微镜系统方法

扫描电子显微镜对于材料研究来说是一个很好的工具,该工具在较大扫描尺度上需要在人工操作下探索材料的形貌和组成。当前其发展重点是:通过无需仪器设置的完全自动的仪器操作方法快速地检测出大量的不同性质的样品,例如颗粒样品。技术领域的不断创新与仪器领域关键区域的革新带来一个新层次的操作,其具有的可靠性和准确性开创了一个新的应用领域     

Feasibility Study on the Use of Probabilistic Migration Modeling in Support of Exposure Assessment from Food Contact Materials

The use of probabilistic approaches in exposure assessments of contaminants migrating from food packages is of increasing interest but the lack of concentration or migration data is often referred as a limitation. Data accounting for the variability and uncertainty that can be expected in migration, for example, due to heterogeneity in the packaging system, variation of the temperature along the distribution chain, and different time of consumption of each individual package, are required for probabilistic analysis. The objective of this work was to characterize quantitatively the uncertainty and variability in estimates of migration. A Monte Carlo simulation was applied to a typical solution of the Fick's law with given variability in the input parameters. The analysis was performed based on experimental data of a model system (migration of Irgafos 168 from polyethylene into isooctane) and illustrates how important sources of variability and uncertainty can be identified in order to refine analyses. For long migration times and controlled conditions of temperature the affinity of the migrant to the food can be the major factor determining the variability in the migration values (more than 70% of variance). In situations where both the time of consumption and temperature can vary, these factors can be responsible, respectively, for more than 60% and 20% of the variance in the migration estimates. The approach presented can be used with databases from consumption surveys to yield a true probabilistic estimate of exposure.     

Assessment and Application of National Environmental Databases and Mapping Tools at the Local Level to Two Community Case Studies

Communities are concerned over pollution levels and seek methods to systematically identify and prioritize the environmental stressors in their communities. Geographic information system (GIS) maps of environmental information can be useful tools for communities in their assessment of environmental‐pollution‐related risks. Databases and mapping tools that supply community‐level estimates of ambient concentrations of hazardous pollutants, risk, and potential health impacts can provide relevant information for communities to understand, identify, and prioritize potential exposures and risk from multiple sources. An assessment of existing databases and mapping tools was conducted as part of this study to explore the utility of publicly available databases, and three of these databases were selected for use in a community‐level GIS mapping application. Queried data from the U.S. EPA's National‐Scale Air Toxics Assessment, Air Quality System, and National Emissions Inventory were mapped at the appropriate spatial and temporal resolutions for identifying risks of exposure to air pollutants in two communities. The maps combine monitored and model‐simulated pollutant and health risk estimates, along with local survey results, to assist communities with the identification of potential exposure sources and pollution hot spots. Findings from this case study analysis will provide information to advance the development of new tools to assist communities with environmental risk assessments and hazard prioritization.     

After-effects of working at visual display units

Abstract

Two experiments were carried out to examine the acute and chronic after-effects of working with VDUs on subsequent subjective mood and performance efficiency. Both showed that working at a VDU has a negative after-effect on the user's subjective well-being but only if that person has a high level of cognitive failure. There was no evidence of any such effect on measures of performance efficiency.