Succinct Representations for Abstract Interpretation

Abstract interpretation techniques can be made more precise by distinguishing paths inside loops, at the expense of possibly exponential complexity. SMT-solving techniques and sparse representations of paths and sets of paths avoid this pitfall. We improve previously proposed techniques for guided static analysis and the generation of disjunctive invariants by combining them with techniques for succinct representations of paths and symbolic representations for transitions based on static single assignment. Because of the non-monotonicity of the results of abstract interpretation with widening operators, it is difficult to conclude that some abstraction is more precise than another based on theoretical local precision results. We thus conducted extensive comparisons between our new techniques and previous ones, on a variety of open-source packages.Comment: Static analysis symposium (SAS), Deauville : France (2012

The Costimulatory Pathways And T Regulatory Cells In Ischemia-reperfusion Injury: A Strong Arm In The Inflammatory Response?

Costimulatory molecules have been identified as crucial regulators in the inflammatory response in various immunologic disease models. These molecules are classified into four different families depending on their structure. Here, we will focus on various ischemia studies that use costimulatory molecules as a target to reduce the inherent inflammatory status. Furthermore, we will discuss the relevant role of T regulatory cells in these inflammatory mechanisms and the costimulatory pathways in which they are involved

Lifting CDCL to template-based abstract domains for program verification

The success of Conflict Driven Clause Learning (CDCL) for Boolean satisfiability has inspired adoption in other domains. We present a novel lifting of CDCL to program analysis called Abstract Conflict Driven Learning for Programs (ACDLP). ACDLP alternates between model search, which performs over-approximate deduction with constraint propagation, and conflict analysis, which performs under-approximate abduction with heuristic choice. We instantiate the model search and conflict analysis algorithms with an abstract domain of template polyhedra, strictly generalizing CDCL from the Boolean lattice to a richer lattice structure. Our template polyhedra can express intervals, octagons and restricted polyhedral constraints over program variables. We have implemented ACDLP for automatic bounded safety verification of C programs. We evaluate the performance of our analyser by comparing with CBMC, which uses Boolean CDCL, and Astrée, a commercial abstract interpretation tool. We observe two orders of magnitude reduction in the number of decisions, propagations, and conflicts as well as a 1.5x speedup in runtime compared to CBMC. Compared to Astrée, ACDLP solves twice as many benchmarks and has much higher precision. This is the first instantiation of CDCL with a template polyhedra abstract domain

The Ebbinghaus illusion deceives adults but not young children

The sensitivity of size perception to context has been used to distinguish between ‘vision for action’ and ‘vision for perception’, and to study cultural, psychopathological, and developmental differences in perception. The status of that evidence is much debated, however. Here we use a rigorous double dissociation paradigm based on the Ebbinghaus illusion, and find that for children below 7 years of age size discrimination is much less affected by surround size. Young children are less accurate than adults when context is helpful, but more accurate when context is misleading. Even by the age of 10 years context-sensitivity is still not at adult levels. Therefore, size-contrast as shown by the Ebbinghaus illusion is not a built-in property of the ventral pathway subserving vision for perception but a late development of it, and low sensitivity to the Ebbinghaus illusion in autism is not primary to the pathology. Our findings also show that, although adults in Western cultures have low context-sensitivity relative to East-Asians, they have high context-sensitivity relative to children. Overall, these findings reveal a gradual developmental trend toward ever broader contextual syntheses. Such developments are advantageous, but the price paid for them is that, when context is misleading, adults literally see the world less accurately than they did as children

Justice and the dark arts: law and shamanism in Amazonia

The idea of “law” as a regulating force external to individuals is rapidly gaining traction among Peruvian Urarina. Its uptake and mode of use have been guided by local forms of shamanic practice, reflecting the common basis of law and shamanism in ritual and violence. Yet despite people's best efforts to deploy law on their own terms—namely as a weapon through which a higher force or authority is harnessed to individual ends—law, unlike shamanism, is inherently unifying rather than fragmenting and implies a unitary standard of truth and justice that is inimical to Amazonian political cosmology. Law epitomizes the centralizing processes of the state, promoting a fragile peace but only by establishing a monopoly on violence

Historical ecology, human niche construction and landscape in pre-Columbian Amazonia: a case study of the geoglyph builders of Acre, Brazil

This paper applies concepts from the fields of historical ecology and human niche construction theory to interpret archaeological and palaeoecological data from the Brazilian state of Acre, southwest Amazonia, where modern deforestation has revealed hundreds of pre-Columbian monumental earthworks called 'geoglyphs', largely built between ca. 2000–650 cal. BP (calibrated years before present). Our main objective was to move away from the debate which currently dominates Amazonian archaeology over large- vs. small-scale pre-Columbian environmental impacts, and instead offer a more nuanced interpretation of human-environment interactions in our specific study area. Despite the difficulties presented by working with an incomplete regional archaeological dataset, interpreting our findings in light of these theoretical frameworks allowed us to re-think landscape history and ask new questions about a possible relationship between anthropogenic forests, symbolic capital and monument building in our particular study area