MDA-based re-engineering with Object-Z

This paper describes a practical application of MDA and reverse engineering based on a domain-specific modelling language. A well defined metamodel of a domain-specific language is useful for verification and validation of associated tools. We apply this approach to SIFA, a security analysis tool. SIFA has evolved as requirements have changed, and it has no metamodel. Hence, testing SIFA’s correctness is difficult. We introduce a formal metamodelling approach to develop a well-defined metamodel of the domain. Initially, we develop a domain model in EMF by reverse engineering the SIFA implementation. Then we transform EMF to Object-Z using model transformation. Finally, we complete the Object-Z model by specifying system behavior. The outcome is a well-defined metamodel that precisely describes the domain and the security properties that it analyses. It also provides a reliable basis for testing the current SIFA implementation and forward engineering its successor.

"They're scared of it": Intergroup determinants of attitudes toward children with HIV

The study used an intergroup perspective to explore teachers' willingness to teach children with HIV within mainstream education. One hundred thirty-eight teachers from 13 high schools across the United Kingdom participated in a survey. The results suggest that previous contact with an individual who was HIV positive (whether an adult or a child) was strongly associated with greater willingness to teach a child with HIV. However, this effect disappeared when intergroup anxiety, positive affect, and positive beliefs were included as covariates. There was little evidence that instrumental variables (i.e., relatively pragmatic concerns about infection) were associated with willingness to teach. Participants who had some contact reported lower fear of contagion from a child with HIV, but there was no evidence that this was associated with overall attitudes. The results are interpreted to suggest that interventions to reduce prejudice should not simply concentrate on improving knowledge about HIV transmission.