Stability analysis using mixed models: A critique of tolerance interval methods and a probabilistic solution

Recently, tolerance interval approaches to the calculation of a shelf life of a drug product have been proposed in the literature. These address the belief that shelf life should be related to control of a certain proportion of batches being out of specification. We question the appropriateness of the tolerance interval approach. Our concerns relate to the computational challenges and practical interpretations of the method. We provide an alternative Bayesian approach, which directly controls the desired proportion of batches falling out of specification assuming a controlled manufacturing process. The approach has an intuitive interpretation and posterior distributions are straightforward to compute. If prior information on the fixed and random parameters is available, a Bayesian approach can provide additional benefits both to the company and the consumer. It also avoids many of the computational challenges with the tolerance interval methodology.     

Revisiting the Prediction of Financial Vulnerability

Whether or not a nonprofit organization is vulnerable to financial problems is a concern of all stakeholders of the organization. Recently, Greenlee and Trussel (2000) and Trussel and Greenlee (2001) expanded Tuckman and Chang's work (1991) to predict which organizations are financially vulnerable. This article extends the work of these authors by developing a model of financial vulnerability that includes four financial indicators, controls for the sector to which an organization belongs, and is based on a sample of over ninety‐four thousand organizations. The model is useful as a screening, monitoring, and attention‐getting device.     

Sociology's misfortune: disciplines, interdisciplinarity and the impact of audit culture

This paper is about tendencies to the subversion of sociology as a discipline. It connects external factors of the wider socio-political environment of higher education in the UK, especially those associated with the audit culture and new systems of governance, with the internal organization of the discipline. While the environment is similar for all social science subjects, the paper argues that there are specific consequences for sociology because of characteristics peculiar to the discipline. The paper discusses these consequences in terms of the changing relationship between sociology and the growing interdisciplinary area of applied social studies as a form of 'mode 2 knowledge'. It argues that while sociology 'exports' concepts, methodologies and personnel it lacks the internal disciplinary integrity of other 'exporter' disciplines, such as economics, political science and anthropology. The consequence is an increasingly blurred distinction between sociology as a discipline and the interdisciplinary area of applied social studies with a potential loss of disciplinary identity. The paper concludes with a discussion of how this loss of identity is associated with a reduced ability to reproduce a critical sensibility within sociology and absorption to the constraints of audit culture with its preferred form of mode 2 knowledge.     

Adolescents' attention to traditional and graphic tobacco warning labels: an eye-tracking approach

The objective of this study was determine if the inclusion of Canadian-style graphic images would improve the degree to which adolescents attend to, and subsequently are able to recall, novel warning messages in tobacco magazine advertising. Specifically, our goal was to determine if the inclusion of graphic images would (1) increase visual attention, as measured by eye movement patterns and fixation density, and (2) improve memory for tobacco advertisements among a group of 12 to 14 year olds in the western United States. Data were collected from 32 middle school students using a head-mounted eye-tracking device that recorded viewing time, scan path patterns, fixation locations, and dwell time. Participants viewed a series of 20 magazine advertisements that included five U.S. tobacco ads with traditional Surgeon General warning messages and five U.S. tobacco ads that had been modified to include non-traditional messages and Canadian-style graphic images. Following eye tracking, participants completed unaided- and aided-recall exercises. Overall, the participants spent equal amounts of time viewing the advertisements regardless of the type of warning message. However, the warning messages that included the graphic images generated higher levels of visual attention directed specifically toward the message, based on average dwell time and fixation frequency, and were more likely to be accurately recalled than the traditional warning messages.     

One Decade of Self Exclusion: Missouri Casino Self-Excluders Four to Ten Years after Enrollment

For more than a decade, casinos around the world have offered self-exclusion programs (SEPs) to gamblers seeking help with their gambling behavior. Despite the proliferation of SEPs, little is known about the long-term outcomes for gamblers who utilize these programs. The current study assessed the experiences of a sample (N = 113) of Missouri self-excluders (SEs) for as long as 10 years after their initial enrollment in the Missouri Voluntary Exclusion Program (MVEP). Most SEs had positive experiences with MVEP and reduced their gambling and gambling problems after enrollment. However, 50% of SEs who attempted to trespass at Missouri casinos after enrollment were able to, indicating that the benefit of MVEP was attributable more to the act of enrollment than enforcement. SEs who engaged in complementary treatment or self-help groups had more positive outcomes than those who did not, suggesting that SEPs ought to encourage and provide information about additional support and treatment options to participants.     

Implementing integrated pest management in professional lawn care: a case study

Human choices regarding land cover management practices may influence ecosystem services provided by urban green spaces. We conducted a 2-year study to compare biological (weed, insect, and disease), aesthetic (lawn quality), and economic (lawn care program cost) attributes of an integrated pest management (IPM) program, in which pesticides are applied on the basis of treatment thresholds, with a standard program, in which pesticides are applied on a calendar basis without pest monitoring. Both programs were managed by a professional lawn care operator. Although weed incidence was low, the IPM program had significantly more lawns with weed presence than the standard program during 2005 and 2006. However, only 21% of the IPM lawns required herbicide applications in 2005, and none exceeded the treatment threshold (5% weed cover) in 2006 as compared to 100% of the standard program lawns being treated for weeds in both years. The IPM program also had significantly more lawns with insect damage than the standard program during June 2005 and August 2005, but not September 2005 and throughout 2006. Only 28% of the IPM lawns required insecticide applications in 2005 and none exceeded the threshold (5% insect damage) in 2006 whereas all of the lawns in the standard program received insecticide treatments in both years. Rhizoctonia blight was present on some of the lawns, but was not a common problem. Although lawn quality was high for both programs (>8, on a scale of 1–9), it was significantly higher for standard than for IPM program lawns during 2005, and June 2006 and September 2006, but not August 2006. The annual lawn management costs were lower for the IPM (281.50) than the standard program (281.50) than the standard program (458.06). Thirty one percent of the IPM program customers who continued with the study in 2006 did so because they were satisfied with the IPM program. Among those who did not continue with the program, 33% cited weed or insect problems, while 33% expected better results. The implications of these findings for implementation of IPM in professional lawn care are further discussed.