Cryptosporidium Dose Response Studies: Variation Between Isolates

The infectivity of three different isolates of the waterborne protozoan parasite Cryptosporidium parvum has been tested in human feeding studies. These three isolates (Iowa, TAMU, and UCP) have different ID50s, indicating substantial variation in their infectivity for humans. This finding is of great importance for quantitative risk assessment as it provides strong evidence for heterogeneity in infectivity among isolates of the same species.     

The racial politics of STEM education in the USA: interrogations and explorations

ABSTRACT

This special issue brings together a mix of early-career, mid, and senior scholars to critically examine current realities of, and boldly imagine future possibilities for, STEM education in the lives of racially minoritized children in the United States. Given the implicit and sometimes explicit aspirations of STEM education to be a counteracting force against racialized injustice, how do students and communities of color experience and make sense of STEM reforms/initiatives? By examining a broad range of STEM contexts including mathematics, computer science, science and environmental science education, and through a diversity of methodological approaches, this special issue aims to contribute to a scholarly conversation about how racialized power intersects with the larger themes and foci of STEM education. In our introduction, we both highlight broad themes of the issue, and offer possible directions for future research at the intersections of race, power, and STEM.     

The influences of gender and grade on perceived work stress and job satisfaction in white collar employees

A self-completion questionnaire survey was carried out, resulting in a sample of 675 white collar public sector employees. The survey examined the frequency of occurrence of work-based stressors and perceived control, and included a general measure of job satisfaction. The results revealed that higher levels of job satisfaction were reported by employees in higher grades. It was also observed that higher grades perceived more control within their working environment. No gender differenccs were found concerning reported stress problems, although significant differences were observed across grades in relation to role differentiation. Multivariate analyses revealed that grade effects were largely accounted for by differences in perceived control. Perceived control, role-based and organizational stressors as well as gender were the strongest contributors in predicting reported job satisfaction.     

Product-limit survival functions with correlated survival times

A simple variance estimator for product-limit survival functions is demonstrated for survival times with nested errors. Such data arise whenever survival times are observed within clusters of related observations. Greenwood's formula, which assumes independent observations, is not appropriate in this situation. A robust variance estimator is developed using Taylor series linearized values and the between-cluster variance estimator commonly used in multi-stage sample surveys. A simulation study shows that the between-cluster variance estimator is approximately unbiased and yields confidence intervals that maintain the nominal level for several patterns of correlated survival times. The simulation study also shows that Greenwood's formula underestimates the variance when the survival times are positively correlated within a cluster and yields confidence intervals that are too narrow. Extension to life table methods is also discussed.     

Rich Ties and Innovative Knowledge Transfer within a Firm

We show that contacts in formal, informal and especially multiplex networks explain transfer of innovative knowledge in an organization. The contribution of informal contacts has been much acknowledged, while that of formal contacts did not receive much attention in the literature in recent decades. No study thus far has included both these different kinds of contacts in a firm, let alone considered their combined effect. The exact overlap between formal as well as informal contacts between individuals, forming multiplex or what we call rich ties because of their contribution, especially drives the transfer of new, innovative knowledge in a firm. Studying two cases in very different settings suggests these rich ties have a particularly strong effect on knowledge transfer in an organization, even when controlling for the strength of ties. Some of the effects on knowledge transfer in an organization previously ascribed to either the formal network or the informal network may actually be due to their combined effect in a rich tie.     

Addressing elder abuse: the Waterloo restorative justice approach to elder abuse project

The Community Care Access Centre (CCAC) of Waterloo Region, in partnership with a number of other social service agencies, designed and implemented a restorative justice model applicable to older adults who have been abused by an individual in a position of trust. The project was very successful in building partnerships, as many community agencies came together to deal with the problem of elder abuse. The program also raised the profile of elder abuse in the community. However, despite intensive efforts, referrals to the restorative justice program were quite low. Because of this, the program moved to a new organizational model, the Elder Abuse Response Team (EART), which has retained the guiding philosophy of restorative justice but has broadened the mandate. The team has evolved into a conflict management system that has multiple points of entry for cases and multiple options for dealing with elder abuse. The team has developed a broad range of community partners who can facilitate referrals to the EART and also can help to provide an individualized response to each case. The transition to the EART has been successful, and the number of referrals has increased significantly.