Survival of Staphylococcus aureus ATCC 13565 in Intermediate Moisture Foods is Highly Variable

Staphylococcus aureus is a gram-positive, enterotoxin-producing coccus. It is a hardy organism and known to survive over a wide range of water activities, pH values, and temperatures. The objective of this study was to model the survival or gradual inactivation of S. aureus ATCC 13565 in intermediate moisture foods (IMFs). Various initial concentrations (approximately 10(1), 10(2), 10(3), and 10(4) CFU/g) were used to inoculate three different IMFs (beefsteak, bread, and chicken pockets). Viable counts were determined up to 60 days using tryptic soy agar. Inoculum size did not influence the survival or gradual inactivation of S. aureus in these foods. The rate of change (increase or decrease) in log CFU/day was calculated for every consecutive pair of data points and by linear regression for each inactivation curve. Both consecutive pair and linear regression rates of change were fit to logistic distributions (with parameters alpha and beta) for each food. Based on the distribution parameters, survival or gradual inactivation of S. aureus was predicted by computer simulation. The simulations indicated an overall decline in S. aureus population over time, although a small fraction of samples in the consecutive pair simulation showed a slight population increase even after 60 days, consistent with the observed data. Simulation results were compared to predictions from other computer models. The models of Stewart et al., were fail-safe, predicting the possibility of significant growth only after > 3,000 days. The USDA pathogen modeling program predictions were found to be fail-dangerous, predicting declines at least four times faster than observed.     

A Home-based Description of Attachment in Physically Disabled Infants

This study investigated attachment security and behavior in 34 physically disabled infants and 26 non‐disabled infants by using convergent, categorical (secure, avoidant and ambivalent) and continuous (Attachment Behavior Q‐Set) measures of the relationship, based on the same set of home observations. Proportions of attachment classifications were not different for disabled and non‐disabled infants, but insecure infants in the disabled group scored consistently lower on the AQS security score than non‐disabled insecure infants. This result suggests that while proportions of attachment classifications may not vary as a function of infant status, insecure disabled infants are more insecure than insecure non‐disabled infants. An analysis of 5 behavioral dimensions of the AQS showed that secure infants emitted the same kinds of attachment behaviors without regard for infant status. Insecure disabled infants, however, showed lower levels of secure base behavior and physical contact with mother than their non‐disabled counterparts, and showed a marginal tendency to fuss more as well. Discussion focuses on the potential benefits of using convergent, categorical and continuous measures of attachment in the study of both typical and atypical groups of infants.     

Applied state space modelling of non-Gaussian time series using integration-based Kalman filtering

The main topic of the paper is on-line filtering for non-Gaussian dynamic (state space) models by approximate computation of the first two posterior moments using efficient numerical integration. Based on approximating the prior of the state vector by a normal density, we prove that the posterior moments of the state vector are related to the posterior moments of the linear predictor in a simple way. For the linear predictor Gauss-Hermite integration is carried out with automatic reparametrization based on an approximate posterior mode filter. We illustrate how further topics in applied state space modelling, such as estimating hyperparameters, computing model likelihoods and predictive residuals, are managed by integration-based Kalman-filtering. The methodology derived in the paper is applied to on-line monitoring of ecological time series and filtering for small count data.     

What Drives Citizen Participation in Political Gatherings in Modern South Africa? A Quantitative Analysis of Self-Reported Behaviour

Social Indicators Research - Community and public gatherings are an important component of political participation in sub-Saharan Africa. Formal and informal community meetings and rallies are...     

The Women’s Empowerment in Livestock Index

Social Indicators Research - The empowerment of women in the livestock sector is fundamental to achieve gender equality. It also is instrumental for increased household productivity and improved...     

THE CONTRIBUTION OF CULTURAL THEORY TO UNDERSTANDING THE EMBEDDEDNESS OF ARGUMENTS IN THE IMPLEMENTATION PROCESS

The aim of this article is to explore the contribution of cultural theory to understanding the embeddedness of arguments in the implementation process. The application of cultural theory to studies of implementation entails investigating the implementation of reforms as different normative arguments pursuing different organizational solutions. Institutional theory posits that implementation of reforms in organizations depends on how well the values defending the reform match the basic values of the organization. Cultural theory contributes to institutional theory in two ways: firstly, cultural theory is an instrument for investigating the values that defend the reform; secondly, cultural theory posits that an organization consists of more than one value base. Consequently, cultural theory does not offer a fixed prediction concerning the outcome of implementation.     

No sustained effect of aerobic or resistance training on insulin sensitivity in nonobese, healthy older women

It is unclear whether long-term aerobic (AT) or resistance (RT) training can improve insulin sensitivity (IS) beyond the residual effect of the last training bout in older women (54-78 years). Therefore, a group of nonobese, healthy older women underwent 6 months of AT (n = 8) or RT (n = 10), and the authors measured IS 4 days after the last training bouts using the hyperinsulinemic-euglycemic clamp technique. Women trained 3 days/week. AT consisted of 25- to 60-min sessions of walking/jogging at 60-95% of maximal heart rate. RT consisted of three sets of nine exercises repeated 10 times at 80% of 1 repetition maximum. AT decreased fat mass, whereas both AT and RT increased fat-free mass. Neither training program, however, improved absolute or relative rates of glucose disposal. The authors therefore concluded that nonobese, healthy older women should perform AT or RT on a daily basis in order to improve IS and maintain the improvement.     

Decompartmentalizing the sociology of activist commitment. A critical survey of some recent trends in French research

This article is a critical survey of a field of research that for 20 years has been particularly active in France and is once again gaining momentum: the sociology of activist commitment. An outcome of this sociological current was the inter-actionist paradigm, i.e. how activists’ careers are embarked upon and evolve. The notion of how to reward activism has been refined and reconsidered. Theoretical debates relating to the surfacing – or not – of “new forms” of activism – or even “new activists” – are replaced in perspective and the two challenges that confront research today stressed. Both concern the social division of labor: how to account more thoroughly for the link between macro-social transformations and individual commitment, on one hand, how organizations are instrumental in formatting activism, on the other.