Is a matrix exponential specification suitable for the modeling of spatial correlation structures?

This paper investigates the adequacy of the matrix exponential spatial specifications (MESS) as an alternative to the widely used spatial autoregressive models (SAR). To provide as complete a picture as possible, we extend the analysis to all the main spatial models governed by matrix exponentials comparing them with their spatial autoregressive counterparts. We propose a new implementation of Bayesian parameter estimation for the MESS model with vague prior distributions, which is shown to be precise and computationally efficient. Our implementations also account for spatially lagged regressors. We further allow for location-specific heterogeneity, which we model by including spatial splines. We conclude by comparing the performances of the different model specifications in applications to a real data set and by running simulations. Both the applications and the simulations suggest that the spatial splines are a flexible and efficient way to account for spatial heterogeneities governed by unknown mechanisms

Applying the Intervention Mapping protocol to develop a kindergarten-based, family-involved intervention to increase European preschool children's physical activity levels: The ToyBox-study

Although sufficient physical activity is beneficial for preschoolers' health, activity levels in most preschoolers are low. As preschoolers spend a considerable amount of time at home and at kindergarten, interventions should target both environments to increase their activity levels. The aim of the current paper was to describe the six different steps of the Intervention Mapping protocol towards the systematic development and implementation of the physical activity component of the ToyBox-intervention. This intervention is a kindergarten-based, family-involved intervention implemented across six European countries. Based on the results of literature reviews and focus groups with parents/caregivers and kindergarten teachers, matrices of change objectives were created. Then, theory-based methods and practical strategies were selected to develop intervention materials at three different levels: (i) individual level (preschoolers); (ii) interpersonal level (parents/caregivers) and (iii) organizational level (teachers). This resulted in a standardized intervention with room for local and cultural adaptations in each participating country. Although the Intervention Mapping protocol is a time-consuming process, using this systematic approach may lead to an increase in intervention effectiveness. The presented matrices of change objectives are useful for future programme planners to develop and implement an intervention based on the Intervention Mapping protocol to increase physical activity levels in preschoolers

Designing and implementing teachers' training sessions in a kindergarten-based, family-involved intervention to prevent obesity in early childhood. The ToyBox-study

Since school-based interventions are mainly delivered by the school staff, they need to be well-trained and familiarized with the programme's aims, procedures and tools. Therefore, the institute, research group, governmental or non-governmental body in charge of the coordination and implementation of the programme needs to devote time and resources to train the school staff before programme's implementation. This is particularly crucial in multi-centre studies where more than one research teams are involved. Both research teams and school staff need to be trained, using standard protocols and procedures, to ensure that the intervention will be delivered in a standardized manner throughout the intervention centres. The ToyBox-intervention, a multi-component, kindergarten-based, family-involved intervention, focusing on water consumption, snacking, physical activity and sedentary behaviours in preschool children, was implemented over the academic year 2012-2013 in six European countries. As part of this intervention, three teachers' training sessions were delivered to motivate and train teachers in implementing the intervention. The local researchers were trained centrally before delivering the training sessions for the teachers and followed a common protocol using standardized presentations and procedures. The aim of the current paper is to describe the protocol and methodological issues related to the teachers' training sessions conducted within the ToyBox-intervention