A proposal for evaluating psychosocial trauma

Background: The objective of the study was to design and validate the Psychosocial Trauma Scale (ETAPS) for assessing psychosocial consequences of collective violence. This instrument proposed the following dimensions: Pre-traumatic Situation, Destruction of Fundamental Beliefs, Intergroup Emotions, and Family and Community Destruction. Method: A total of 382 people participated who had been affected by political violence: civil war in El Salvador, forced displacement from Colombia and state violence from Chile. The study had three phases: (1) content validity of the items evaluated by experts; (2) exploratory factor analysis to study the structure of ETAPS, reducing the number of items; (3) convergent (post-traumatic stress symptomatology) and divergent (psychological and social well-being) validity. Results: The EFA showed that ETAPS had a slightly different internal structure from that proposed. The dimensions found were Pre-traumatic Situation and Intergroup Emotions along with two new emerging dimensions: Destruction of Sociality and Personal and Collective Self-Efficacy. Divergent and convergent validity gave expected results except for the pre-traumatic situation. Conclusions: The ETAPS dimensions show that the effects of violence are broader than the symptoms measured by clinical scales. An instrument with adequate psychometric properties was obtained which will be useful for future studies in the area

Sharper and Simpler Nonlinear Interpolants for Program Verification

Interpolation of jointly infeasible predicates plays important roles in various program verification techniques such as invariant synthesis and CEGAR. Intrigued by the recent result by Dai et al.\ that combines real algebraic geometry and SDP optimization in synthesis of polynomial interpolants, the current paper contributes its enhancement that yields sharper and simpler interpolants. The enhancement is made possible by: theoretical observations in real algebraic geometry; and our continued fraction-based algorithm that rounds off (potentially erroneous) numerical solutions of SDP solvers. Experiment results support our tool's effectiveness; we also demonstrate the benefit of sharp and simple interpolants in program verification examples

Asynchronous Multiparty Session Type Implementability is Decidable - Lessons Learned from Message Sequence Charts

Multiparty session types (MSTs) provide efficient means to specify and verify asynchronous message-passing systems. For a global type, which specifies all interactions between roles in a system, the implementability problem asks whether there are local specifications for all roles such that their composition is deadlock-free and generates precisely the specified executions. Decidability of the implementability problem is an open question. We answer it positively for global types with sender-driven choice, which allow a sender to send to different receivers upon branching and a receiver to receive from different senders. To achieve this, we generalise results from the domain of high-level message sequence charts (HMSCs). This connection also allows us to comprehensively investigate how HMSC techniques can be adapted to the MST setting. This comprises techniques to make the problem algorithmically more tractable as well as a variant of implementability that may open new design space for MSTs. Inspired by potential performance benefits, we introduce a generalisation of the implementability problem that we, unfortunately, prove to be undecidable

AskTheCode: Interactive Call Graph Exploration for Error Fixing and Prevention

In order to prevent and fix errors in program code, developers need to understand its semantics to a significant extent. For this purpose, they use various approaches, such as manual call graph exploration or dynamic analysis with a debugger. However, these techniques tend to be cumbersome in a larger codebase, because they provide either underapproximate or overapproximate results and it is often hard to combine them. Therefore, we present AskTheCode, a Microsoft Visual Studio extension enabling to interactively explore a call graph, ensuring that only feasible execution traces are taken into consideration. AskTheCode is based on control flow analysis and backward symbolic execution. We show its potential to significantly improve developers' experience on a complex code example